Sepsis-associated lung injury arises from a dysregulated response to infection and frequently involves acute respiratory distress syndrome, or ARDS. A meta-analysis cited in the review estimated that ARDS develops in 34.0% of patients with sepsis, with a 95% confidence interval of 29.0% to 39.3%. Lysosomes and related endolysosomal compartments sit directly at the host–pathogen interface: acidic phagolysosomes support microbial killing in macrophages, lamellar bodies participate in surfactant biology in type II alveolar epithelial cells, and lysosomal degradation and trafficking contribute to endothelial repair and fibroblast matrix turnover. Infection-related stress could therefore compromise both pathogen control and the cellular processes needed to preserve the lung’s gas-exchange barrier. The proposed link between these defects and lysosomal pH remains incompletely mapped, however, particularly in human disease.

Central to the hypothesis is the V-ATPase complex, which hydrolyzes ATP to pump protons into lysosomal compartments and create the acidic conditions required by many lysosomal hydrolases. V-ATPase is also a signaling platform influenced by nutrient sensing, trafficking, complex assembly and stress. In macrophages, the ATP6V0D2 subunit has been associated with autophagosome–lysosome fusion and restrained inflammasome activation during bacterial challenge, illustrating that its role cannot be reduced to setting basal acidity. The mTORC1–TFEB pathway provides another connection between nutrient status, lysosomal biogenesis, autophagy and stress adaptation, but the review cautions that TFEB does not uniformly increase every acidification-related transporter across cell types or conditions. Similarly, PI3K–AKT signaling may influence lysosomal resilience indirectly through metabolism, mitochondrial function and membrane stability; a direct AKT-driven alkalinization mechanism has not been established in septic lung cells.

Acidification also depends on the movement of counterions. ClC-7 is a late-endosomal and lysosomal chloride–proton exchanger that requires the accessory protein OSTM1 for stability. Recent work indicates that ClC-7 promotes chloride accumulation in mature phagosomes, hydrolase activity and phagosome resolution. Its influence on bulk lysosomal acidity is more complicated, with genetic studies reporting altered chloride distribution and storage phenotypes without consistent loss of acidification. The authors therefore describe ClC-7 primarily as a regulator of luminal chloride with context-dependent effects on pH. TMEM175, an endolysosomal potassium channel implicated in membrane potential and pH stability, presents another unresolved question. Models disagree over whether it conducts protons or predominantly potassium, and the evidence comes largely from heterologous systems or non-septic neurodegeneration-related models. Its role in pulmonary sepsis has not been directly tested.

A further complication is that lysosomal pH is not equivalent to every other sign of lysosomal dysfunction. The review distinguishes increased luminal pH from membrane permeabilization, reduced hydrolase activity, impaired autophagic flux and changes in lysosomal mass or biogenesis. Markers such as LC3-II, p62, cathepsin abundance and LysoTracker intensity can each be altered by organelle number, trafficking, cargo load, membrane damage or probe behavior. LC3-II accumulation, for example, may reflect either increased autophagy or failure of lysosomal degradation. Direct acidity evidence ideally comes from compartment-targeted ratiometric probes calibrated in situ with ionophores and defined-pH buffers. Single-wavelength acidotropic dyes are useful for locating lysosomes but cannot, by themselves, provide stand-alone pH values. This distinction is especially important in sepsis, where cell death, systemic acid–base disturbances and changes in organelle abundance can confound commonly used readouts.

Microbial and host signals could disturb lysosomal homeostasis in several ways. Lipopolysaccharide activates TLR4–MyD88/TRIF and NF-κB inflammatory signaling in pulmonary immune and structural cells, but available evidence does not show universal repression of acidification machinery. Instead, changes in trafficking, cytokines, nitroxidative stress, metabolism and autophagic flux may indirectly alter lysosomal function. Tumor necrosis factor alpha, interleukin-1 beta and interleukin-6 can promote reactive oxygen species, mitochondrial injury, metabolic reprogramming and dysregulated autophagy–lysosome flux. Persistent stress may reduce ATP-dependent proton pumping, disturb membrane stability or overload degradative capacity. Lysosomal membrane permeabilization can then release cathepsins and other contents into the cytosol. Cathepsin B has been linked to NLRP3 inflammasome activation and pyroptosis-related signaling in experimental sepsis-associated lung injury, but its contribution depends on the cell and stimulus. Reduced lysosomal acidity is thus best considered a possible permissive amplifier working with mitochondrial reactive oxygen species, potassium efflux, danger signals and defective autophagic clearance, not as the sole trigger of inflammation.

The consequences may differ sharply among the cells that form and defend the alveolar–capillary barrier. In macrophages and dendritic cells, impaired lysosomal or phagolysosomal function may reduce microbial killing, cargo degradation and antigen processing, which is why indiscriminate suppression of lysosomal activity could be counterproductive. In epithelial and endothelial cells, lysosomal injury may contribute to protease release, junctional disruption, vascular leakage and defective repair through convergent mechanisms, but direct pH-to-junction causality has not been established. Type II epithelial lamellar bodies have specialized functions in calcium handling and surfactant secretion that should not be equated automatically with canonical lysosomes. During persistent or non-resolving injury, impaired lysosomal degradation may also hinder removal of damaged mitochondria, oxidized lipids and mitochondrial DNA, potentially sustaining TLR9, cGAS–STING and NLRP3 pathways. Evidence linking lysosomal pH to fibrotic matrix remodeling comes mainly from pulmonary fibrosis research, and direct human evidence in post-sepsis lung injury remains limited.

Mitophagy and inter-organelle proton transfer add another possible dimension. Mitochondria and lysosomes communicate through mitophagy, reactive oxygen species, lipid transfer and direct membrane contact sites. Mitochondrial injury can restrict the ATP and redox conditions needed for V-ATPase activity, while defective lysosomal trafficking can reduce mitochondrial clearance and allow dysfunctional mitochondria to accumulate. Studies in yeast and human cells have now shown proton transfer from mitochondria to lysosomes at contact sites, with experimental organelle tethering improving acidification, cargo degradation and autophagic flux. These observations are mechanistically relevant but were not conducted in septic lung models, and no cited sepsis study simultaneously quantified mitochondria–lysosome contacts and lysosomal pH. The relative contributions of V-ATPase and counterion dysfunction, membrane damage and contact-mediated proton transfer therefore remain unresolved in this disease context.

Because the model is not yet ready for clinical application, the authors propose measured rather than diagnostic biomarker panels. A bronchoalveolar lavage fluid strategy could combine calibrated lysosomal pH in recovered alveolar macrophages, intralysosomal cathepsin B and D activity, cytosolic cathepsin redistribution, and extracellular cathepsin or LAMP1/2. A high-pH, low-hydrolase phenotype with limited extracellular release would be consistent with impaired acidification, whereas cathepsin redistribution and extracellular release would favor membrane injury. A less invasive blood panel could assess calibrated pH in circulating monocytes, cathepsin localization and autophagic flux, although neither LC3-II nor p62 alone would establish alkalinization. These are proposed test strategies rather than validated signatures and would require longitudinal cohorts, comparison with established measures such as oxygenation, lactate, procalcitonin and inflammatory markers, and analysis of whether blood and lung samples identify the same phenotypes.

Therapeutic development would likewise need to distinguish disease phase and molecular phenotype. An alkalinization-dominant state with impaired phagocyte degradation could justify testing controlled restoration of acidification or lysosomal biogenesis. One compound, ZLN005, increased lysosomal acidity and biogenesis in phagocytes and improved bacterial killing and survival in experimental polymicrobial sepsis, but its effects also involved PGC-1α, PI3K and TFEB, preventing attribution of benefit solely to pH correction. Selectively applicable clinical V-ATPase activators are not established. Conversely, a membrane-injury phenotype without clear alkalinization would support testing membrane stabilization or carefully titrated protease modulation, since broad cathepsin inhibition could interfere with microbial killing and tissue remodeling. Future experiments should combine spatial or single-cell identification of lysosomal stress with calibrated pH measurement, hydrolase assays, membrane-permeabilization tests and flux analysis in infection models, co-cultures, organoids and precision-cut lung slices. The defensible conclusion is that lysosomal pH homeostasis deserves testing as a mechanistic and stratification axis for sepsis-associated lung injury, not that it has already been established as a precision-medicine target.

Subject of Research: Lysosomal pH dysregulation as a candidate amplifier of sepsis-associated lung injury

Article Title: Lysosomal pH dysregulation as a candidate signal-amplifying hub in sepsis-associated lung injury

Article References: Tu, G., Deng, Z., Li, Y., Tian, P., Shen, Y., Deng, Y., Zhang, Z., Liu, Y., Zhong, S., Wu, J., Zhu, H., Ma, J., & Li, J. (2026). Lysosomal pH dysregulation as a candidate signal-amplifying hub in sepsis-associated lung injury. Frontiers in Cellular and Infection Microbiology, 16, Article 1953667. https://doi.org/10.3389/fcimb.2026.1953667

Image Credits: AI Generated

DOI: 10.3389/fcimb.2026.1953667

Keywords: lysosomal pH, sepsis, lung injury, ARDS, V-ATPase, inflammation, autophagy, mitochondria–lysosome crosstalk, host–pathogen interaction, Lysosomal, dysregulation, candidate

The clinical stakes are enormous. Chronic alcohol abuse is a major risk factor for ARDS development, and clinical studies show that alcohol consumers who develop ARDS face a three- to four-fold higher incidence and mortality rate compared to non-drinkers. Nearly half of all ARDS cases are associated with chronic alcohol use, a condition researchers have termed the alcoholic lung. Alcohol abuse even worsens ARDS outcomes in COVID-19 patients. Yet the mechanisms by which alcohol increases ARDS susceptibility have remained largely unknown. Potential explanations include structural damage to alveolar epithelial cells, increased reactive oxygen species production, breakdown of the epithelial barrier, and impaired alveolar fluid reabsorption, but the precise signaling pathways connecting these observations have been elusive.

At the heart of the new study, published in Frontiers in Pharmacology, is a biological process called alveolar fluid clearance, or AFC. Efficient clearance of edema fluid from the airspaces is essential for restoring gas exchange and correcting hypoxemia in ARDS, making it a key therapeutic goal. Alveolar epithelial cells maintain the alveolar barrier and fluid balance through transport channels such as aquaporins, chloride channels, and potassium channels, but it is the directional transport of sodium ions that critically determines pulmonary edema resolution. Two major sodium transporters dominate this process: the epithelial sodium channel, ENaC, which sits on the apical membrane and pulls sodium from the airspaces into the epithelial cells, and Na+,K+-ATPase, which occupies the basolateral membrane and actively pumps sodium out of the cells into the interstitial space. Together these channels keep the alveolar environment relatively dry, and genetic deletion of ENaC in alveolar epithelial cells significantly impairs fluid clearance and increases lung water content.

Previous work had already hinted that alcohol targets this machinery. Chronic alcohol use upregulates integrin αvβ6, an adhesion molecule specifically expressed in epithelial cells that serves as a key activator of latent transforming growth factor beta 1, or TGF-β1. In the lung, TGF-β1 activation weakens barrier integrity and increases susceptibility to injury, partly by promoting oxidative stress through glutathione depletion in alveolar epithelial cells and impairing surfactant function. In vitro studies have shown that TGF-β1 accumulation in the alveoli disrupts epithelial barrier function, and renal epithelial cell experiments demonstrated that TGF-β1 activation inhibits ENaC expression. TGF-β1, in turn, is a key activator of Smad4, a central mediator of the TGF-β1 signaling pathway that network pharmacology and in vivo studies have identified as a potential therapeutic target for ARDS. In renal collecting duct cells, TGF-β1 suppresses ENaC expression via Smad4. Whether this same axis regulated pulmonary sodium channels during alcohol-induced ARDS, however, was previously unknown.

To answer that question, the team led by Xue Dai and corresponding author Wang Deng established chronic alcohol exposure models in both mice and MLE-12 cells, a line of type II alveolar epithelial cells, and then induced ARDS with intratracheal lipopolysaccharide, or LPS. In mice, the alcohol concentration in drinking water was gradually increased from 5 to 20 percent over the first week and maintained at 20 percent for six weeks, achieving mean blood alcohol concentrations of 150 to 200 milligrams per deciliter or higher. In vitro, the researchers screened alcohol concentrations from 20 to 120 millimolar and exposure durations from 12 to 72 hours, identifying 60 millimolar alcohol for 48 hours as the optimal condition that simulated chronic exposure while minimizing excessive cellular damage. The team then selectively inhibited the pathway at two points: GSK3008348, a selective integrin αvβ6 inhibitor, was administered intranasally, while SB431542, a selective TGF-β1 inhibitor, was injected intraperitoneally. Vehicle controls confirmed that neither the DMSO carrier nor the drugs themselves altered alveolar architecture, TGF-β1 protein levels, or cell viability, validating the experimental system.

The results were striking. Semi-quantitative histological scoring of hematoxylin and eosin-stained lung sections revealed that chronic alcohol-induced ARDS produced significantly more severe tissue injury than ARDS alone, and inhibition of the integrin αvβ6/TGF-β1/Smad4 pathway significantly alleviated the damage. Seven-day survival rates told the same story: mice with chronic alcohol-induced ARDS had significantly lower survival than those with ARDS alone, while pathway inhibition resulted in significantly increased survival. Vascular permeability and pulmonary edema, assessed by Evans blue dye extravasation, lung wet-to-dry weight ratio, and bronchoalveolar lavage fluid total protein content, all worsened dramatically with chronic alcohol exposure and improved when either integrin αvβ6 or TGF-β1 was blocked. Inflammatory cytokines TNF-α and IL-6, measured by ELISA in both bronchoalveolar lavage fluid and serum, were significantly elevated in chronic alcohol-induced ARDS and reversed by pathway inhibition, as were total cell counts in the lavage fluid.

In vitro experiments added cellular resolution to the picture. MLE-12 cells pretreated with alcohol and then exposed to LPS showed significantly higher cytotoxicity than cells treated with LPS alone, an effect ameliorated by pathway inhibition. Scratch assays revealed that chronic alcohol-induced ARDS conditions significantly suppressed alveolar epithelial cell migration, a measure of barrier repair capacity, and targeted pathway intervention effectively restored it. Western blot analysis demonstrated that chronic alcohol exposure activated the entire signaling cascade, increasing expression of integrin β6, TGF-β1, and Smad4 in both lung tissue and cultured cells. Critically, the upstream-downstream relationships held: blocking integrin αvβ6 prevented the alcohol-driven elevation of TGF-β1, while blocking TGF-β1 diminished the role of integrin αvβ6 in pathway activation. However, TGF-β1 inhibition did not alter integrin αvβ6 levels, confirming that TGF-β1 functions downstream of integrin αvβ6 in this cascade.

The pivotal experiment concerned Smad4 and the sodium transporters themselves. After confirming effective Smad4 knockdown with small interfering RNA, the researchers found that silencing Smad4 attenuated the alcohol-induced suppression of ENaC-α and Na+,K+-ATPase α1 expression in alveolar epithelial cells pretreated with alcohol and exposed to LPS. Western blot analysis in both in vivo and in vitro models revealed that the alcohol-induced ARDS group showed significant decreases in all three ENaC subunits, α, β, and γ, and in both Na+,K+-ATPase subunits, α1 and β1, compared to the ARDS group without alcohol. Inhibition of the integrin αvβ6/TGF-β1 pathway restored their expression levels. Immunofluorescence microscopy confirmed these findings visually, showing that chronic alcohol exposure significantly reduced the fluorescence signal intensity of ENaC and Na+,K+-ATPase, whereas pathway inhibition markedly restored the signals. Functional assays demonstrated that chronic alcohol consumption inhibited Na+,K+-ATPase activity, and suppression of the integrin αvβ6/TGF-β1 pathway resulted in partial recovery of pump function.

These findings clarify the regulatory mechanisms of sodium channels in ARDS associated with chronic alcohol consumption and identify the integrin αvβ6/TGF-β1/Smad4 axis as a key mediator of the alcoholic lung. The work builds on earlier observations that Smad4 regulates sodium transporters in the kidney and heart, extending this regulatory principle to the pulmonary epithelium during alcohol-induced ARDS. Smad4 appears to act as a negative regulator of these transporters, contributing to edema accumulation when the pathway is activated by chronic alcohol exposure. The authors acknowledge several limitations: the study focused primarily on Smad4 as the downstream effector of TGF-β1, leaving other downstream targets unexplored; the findings relied on MLE-12 cells without validation in primary alveolar epithelial cells; and the results are based on murine models and in vitro experiments whose relevance to human physiology requires further investigation. The team also notes that quantitative analysis was confined to ENaC protein expression levels, and direct functional evidence of ENaC activity would provide more compelling support for the regulatory mechanism.

Nevertheless, the translational implications are considerable. Inhaled small-molecule integrin αvβ6 inhibitors are already being developed for idiopathic pulmonary fibrosis, and the new study suggests that similar pharmacological strategies could protect the alveolar epithelium’s sodium transport machinery in patients with chronic alcohol exposure who develop ARDS. By revealing that chronic alcohol exacerbates pulmonary edema through suppression of ENaC and Na+,K+-ATPase via a defined signaling cascade, the research offers novel molecular insights into ARDS pathogenesis and identifies integrin αvβ6, TGF-β1, and Smad4 as potential therapeutic targets for a patient population that has long faced disproportionately poor outcomes. For the roughly half of ARDS cases linked to chronic alcohol use, this discovery transforms the alcoholic lung from a clinical observation into a mechanistic roadmap, one that may finally guide the development of targeted therapies for a syndrome that has resisted every pharmacological intervention tried so far.

Subject of Research: Cell Biology

Article Title: The integrin αvβ6/TGF-β1/Smad4 signaling pathway regulates ENaC in alcohol induced ARDS

Article References: Dai, X., Liu, X.-L., Liu, M.-J., Li, T., Wang, D.-X., & Deng, W. (2026). The integrin αvβ6/TGF-β1/Smad4 signaling pathway regulates ENaC in alcohol induced ARDS. Frontiers in Pharmacology, 17, Article 1931568. https://doi.org/10.3389/fphar.2026.1931568

Image Credits: AI Generated

DOI: 10.3389/fphar.2026.1931568

Keywords: ARDS, alcohol, ENaC, TGF-beta, Smad4, integrin alpha v beta 6, alveolar fluid clearance, pulmonary edema, lung injury, sodium channels, integrin, TGF-

The analysis, led by Xinru Wu and Tiancheng Yu with colleagues at Kunshan Integrated TCM and Western Medicine Hospital, Nanjing Tech University, Jiangsu Normal University and collaborating institutions, drew on two of the largest literature databases in science: the Web of Science Core Collection and Scopus. Searching from January 2015 to a cutoff of May 25, 2026, the team retrieved 702 qualifying articles from Web of Science and 334 from Scopus, restricting results to original research articles and reviews in English. They then processed this corpus with a suite of visualization tools — VOSviewer for collaboration and co-occurrence networks, CiteSpace for citation bursts, and the Bibliometrix package in R for knowledge maps — to reveal where the field has been and where it is heading.

The headline finding is a dramatic inflection point in publication output. Output remained modest between 2015 and 2018, with small year-to-year fluctuations, before entering a phase of rapid and sustained growth after 2019. Web of Science output peaked at 133 articles in 2025, while Scopus recorded 74 that year. The authors attribute the surge to several converging forces: the maturing of the gut-lung axis framework, the broad adoption of high-throughput sequencing and multi-omics technologies, and heightened interest in host-microbiome interactions during and after the COVID-19 pandemic. The apparently low numbers for 2026 simply reflect the partial-year search window rather than any slowdown.

Geographically, the field is strikingly concentrated. China led global output with 483 Web of Science publications — roughly 69 percent of the dataset — followed by the United States with 79. The pattern held in Scopus, where China accounted for 265 of 334 articles. At the institutional level, Fudan University topped both databases and emerged as the core hub of the collaboration network. Yet the study also flagged a notable weakness: international collaboration remains thin. Only about 5 to 6 percent of Chinese publications involved co-authors from multiple countries, compared with 19 to 32 percent for the United States, suggesting that despite China’s dominance in volume, the field’s collaborative fabric is still being woven.

Journal analysis revealed Frontiers in Immunology as the field’s central publication and citation hub, with 34 articles and 1,165 citations in the Web of Science dataset. Other productive outlets included Frontiers in Microbiology, Frontiers in Pharmacology, Journal of Ethnopharmacology and Frontiers in Cellular and Infection Microbiology, while highly cited nodes extended to PLoS ONE, Nature, the American Journal of Respiratory and Critical Care Medicine and Gut. The most influential individual papers spanned a remarkable range: a Science study on the microbial metabolite desaminotyrosine protecting against influenza through type I interferon signaling, a Nature Immunology paper on innate immune responses to trauma, and work on how gut microbiota modulates LPS-induced acute lung injury via the TLR4/NF-κB pathway. Citation-burst detection highlighted the strongest surges around papers on microbiota and the gut-lung axis, host defense against pneumococcal pneumonia, and, most recently, gut-lung crosstalk in sepsis-induced lung injury and microbiota-derived succinate aggravating injury after intestinal ischemia-reperfusion.

Keyword clustering distilled the field into a handful of coherent themes. Inflammation was the most frequent keyword, followed by microbiota, the gut-lung axis, mouse models and sepsis. The clusters pointed to gut-lung axis-mediated immune regulation, oxidative stress and inflammatory signaling, the protective functions of short-chain fatty acids, sepsis and critical illness-related injury, environmental exposure-induced microecological imbalance, and targeted interventions using probiotics and dietary strategies. Thematic evolution analysis showed a clear trajectory: early work from roughly 2017 to 2020 focused on intestinal permeability, mesenteric lymph and bacterial translocation; the middle phase from 2021 to 2023 shifted to dysbiosis and inflammatory pathway activation; and studies from 2024 onward have moved toward macrophage polarization, aryl hydrocarbon receptor-mediated immunometabolism, high-throughput sequencing and the hunt for clinical diagnostic biomarkers for acute respiratory distress syndrome.

The scientific rationale underlying this boom is compelling. Acute lung injury and its severe form, ARDS, affect roughly 86 people per 100,000 globally each year, and severe cases still carry mortality rates of 40 to 50 percent. Sepsis accounts for more than 60 percent of cases, and current treatments — lung-protective ventilation, fluid management, anti-infection therapy and glucocorticoids — remain largely supportive, with no drugs that specifically interrupt the core pathological cascade. Against this backdrop, the gut-lung axis offers an entirely new therapeutic entry point. Through the axis, gut microbes and their metabolites reach the circulation, immune cells migrate between mucosal sites, vagal signals travel between the organs, and, when the gut barrier fails, bacteria and their toxins translocate into the bloodstream.

Mechanistically, the field has converged on three hotspots. The first concerns how gut microbiota shapes the pulmonary immune microenvironment: intestinal CD103-positive dendritic cells secrete retinoic acid, programming lymphocytes with homing receptors that guide them to bronchus-associated lymphoid tissue and the alveolar interstitium, where they secrete IgA, interferon-gamma and interleukin-17, while gut-derived regulatory T cells produce IL-10 and TGF-beta to restrain excessive inflammation. When dysbiosis breaches the epithelial barrier, lipopolysaccharide enters the circulation, activates TLR4 and fans systemic inflammation that lands in the lungs. The second hotspot centers on short-chain fatty acids — acetate, propionate and butyrate produced by fiber fermentation — which dampen NF-κB and MAPK signaling through G protein-coupled receptors and histone deacetylase inhibition, push alveolar macrophages toward reparative M2 phenotypes, strengthen tight junctions via ZO-1 and occludin, protect the alveolar-capillary barrier, activate the Nrf2 antioxidant pathway and even slow pulmonary fibrosis by suppressing TGF-beta1/Smad signaling. The third involves microecological interventions, from Lactobacillus and Bifidobacterium strains that rebalance macrophage polarization to traditional Chinese medicine compounds such as ruscogenin and 8β-hydroxy-α-cyclocostunolide, whose mechanisms the authors note align strikingly with the ancient TCM principle that the lung and large intestine are interior-exterior related.

Clinical evidence is beginning to back the preclinical enthusiasm. Patients with ALI and ARDS consistently show severe gut dysbiosis — reduced microbial diversity, a shifted Firmicutes/Bacteroidetes ratio, depleted beneficial Bifidobacterium and Lactobacillus, and overgrowth of opportunists such as Escherichia coli — and the degree of dysbiosis correlates with oxygenation indices, inflammatory markers, ventilation duration and 28-day mortality. During the COVID-19 pandemic, certain probiotic strains were reported to reduce nasopharyngeal viral load and pulmonary inflammatory infiltration. Yet the bibliometric keyword analysis exposed the field’s central weakness: terms like nonhuman, animals, mouse model and animal experiment dominate the literature, particularly in the Scopus dataset where they topped the frequency tables.

The authors are candid about this gap. The principal deficit, they conclude, is not a shortage of candidate mechanisms but the limited validation of strain-specific, metabolite-specific and dose-dependent effects in standardized human studies. Probiotic efficacy varies by strain and dose, unified clinical criteria are lacking, and different causes of lung injury may demand individualized microbial strategies. They also acknowledge the limitations of their own approach — only two databases, English-language literature and restricted document types — which may bias trends and rankings. Still, the study offers researchers a clear map: the field has built its mechanistic foundations in animals, and the next decade’s challenge, the authors argue, lies in large-scale, multicenter randomized controlled trials, multi-omics biomarker discovery, and the careful translation of gut-lung axis science into precision interventions for the intensive care units where lung injury claims so many lives.

Subject of Research: Bibliometric mapping of gut microbiota and lung injury research from 2015 to 2026

Article Title: Research progress and trends of gut microbiota and lung injury: a bibliometric and visualization analysis based on two databases (2015–2026)

Article References: Wu, X., Yu, T., Hu, S., & Zhang, T. (2026). Research progress and trends of gut microbiota and lung injury: a bibliometric and visualization analysis based on two databases (2015–2026). Frontiers in Medicine, 13, Article 1902880. https://doi.org/10.3389/fmed.2026.1902880

Image Credits: AI Generated

DOI: 10.3389/fmed.2026.1902880

Keywords: gut microbiota, gut-lung axis, lung injury, acute respiratory distress syndrome, bibliometrics, short-chain fatty acids, probiotics, sepsis, traditional Chinese medicine, pulmonary immunity, inflammation, microbiome

The research team focused on the distal lung because it is both the site of gas exchange and the most vulnerable part of the respiratory system. Working with human lung epithelial and endothelial cells, as well as precision-cut human lung tissue, the investigators exposed these samples to e-cigarette vapor alone and, in separate experiments, exposed them to vapor followed by infection with a respiratory virus. Within just 24 hours of vapor exposure, the researchers observed damage to the protective barrier of the distal lung, the layer of cells that keeps the airspaces sealed and selectively controls what passes between the air and the blood.

The early cellular response was broad. Vapor exposure triggered cellular stress, impaired autophagy, the internal recycling process cells use to clear damaged components, slowed cell growth and repair, and increased cell death. Each of these processes is central to maintaining the integrity of the alveolar-capillary barrier. When barrier function is compromised, fluid and immune cells can leak into the airspaces, and the lung becomes less able to perform its essential task of transferring oxygen while keeping airborne threats out of the circulation.

Perhaps the most striking result was the persistence of injury. Signs of lung stress remained detectable 10 days after a five-day exposure period had ended. The team documented lasting changes in barrier function, tissue remodeling, and Th1 immunity, a branch of the adaptive immune system that is critical for mounting effective responses against viral infections. Tissue remodeling in the distal lung is a particular concern because, if sustained, it can interfere with the fine architecture of the alveoli and contribute to chronic scarring and reduced lung capacity.

The antiviral consequences were equally significant. In the preclinical models, prior vaping exposure increased the viral burden of SARS-CoV-2 following infection and suppressed several antiviral genes. These genes encode proteins that detect viral genetic material, interfere with viral replication, and recruit immune cells to infected tissue. Their suppression means that when a virus arrives, the lung’s early-warning and containment systems are blunted, potentially allowing the pathogen to replicate to higher levels before an effective immune response can be organized.

Senior author Irina Petrache, MD, a pulmonologist and chief of the Division of Pulmonary, Critical Care and Sleep Medicine at National Jewish Health, summarized the implications of the work. Our findings suggest that even short-term vaping exposure can initiate injury in the deepest and most delicate regions of the lung, she said. Importantly, some effects persisted after exposure ended and altered the immune response to a subsequent viral infection. That combination, acute injury followed by lingering immune alteration, is what distinguishes the current findings from earlier work that focused mainly on the immediate effects of vapor exposure.

The study helps explain, at a mechanistic level, why epidemiological and clinical observations have repeatedly linked vaping to lung injury and to greater susceptibility to respiratory infections. Rather than a single toxic event, the research points to a sequence: vapor exposure damages the barrier and stresses the cells, the cells’ repair machinery is slowed, and the immune programming of the tissue shifts in ways that reduce antiviral readiness. Repeated cycles of exposure, the researchers noted, could potentially contribute to chronic lung disease by sustaining cellular injury and disrupting normal repair processes over time.

Technically, the use of precision-cut human lung tissue is an important strength of the study. Unlike isolated cell lines, precision-cut slices preserve the three-dimensional structure of the distal lung, including the relationships between epithelial cells, endothelial cells, and the extracellular matrix that supports them. This means the observed barrier disruption and remodeling reflect interactions among multiple cell types rather than the response of a single cell population. The parallel use of epithelial and endothelial cultures allowed the team to separate contributions from the airside and bloodside linings of the barrier, both of which showed evidence of stress and dysfunction after vapor exposure.

The authors emphasize that the findings will need to be confirmed in future studies in people. Preclinical models, even those built from human cells and tissue, cannot fully capture the complexity of vaping in real-world users, who differ in the devices they use, the e-liquids they inhale, the frequency and depth of their puffing, and their baseline health. Human exposure histories are also far more variable than a controlled five-day exposure regimen. Nonetheless, the demonstration that a brief exposure window can produce measurable and persistent changes in human distal lung tissue provides a biological rationale for concern that complements the population-level associations reported in prior research.

For public health, the message is that risk is not confined to long-term, heavy vaping. If days of exposure can alter barrier integrity, autophagy, repair capacity, and Th1 antiviral immunity in human distal lung tissue, then occasional or new users may not be as protected as commonly assumed, particularly during respiratory virus season. The study also offers researchers concrete mechanistic targets, including barrier repair pathways, autophagy regulation, and antiviral gene expression, that could guide future investigations into which components of e-cigarette vapor drive injury and whether the effects are reversible once exposure stops. As e-cigarette use continues to evolve, work of this kind provides the cellular-level evidence needed to assess its consequences for lung health with greater precision.

Subject of Research: Effects of brief e-cigarette vapor exposure on human distal lung tissue and antiviral immune defenses

Article Title: Even brief e-cigarette use can cause lasting lung damage and weaken defenses against respiratory viruses, study finds

Article References: Even brief e-cigarette use can cause lasting lung damage and weaken defenses against respiratory viruses, study finds. (n.d.). Original publication

Image Credits: AI Generated

DOI: Not provided

Keywords: e-cigarettes, vaping, lung injury, distal lung, epithelial barrier, autophagy, Th1 immunity, SARS-CoV-2, antiviral genes, JCI Insight, National Jewish Health, respiratory infection

The rationale for the combination rests on the complementary profiles of the two drugs. Azvudine, known chemically as FNC, is a nucleoside reverse transcriptase inhibitor approved in China for HIV treatment and later authorized for COVID-19. As an analogue, it is incorporated by viral polymerases and terminates RNA synthesis, acting directly on the SARS-CoV-2 RNA-dependent RNA polymerase. Carrimycin, by contrast, is a macrolide derived from the engineered antibiotic compound 4″-O-isovalerylspiramycin. Macrolides are best known as antibacterials, but several members of the class display immunomodulatory and anti-inflammatory properties, and Carrimycin has previously shown antiviral activity against coronaviruses. Pairing a direct-acting polymerase inhibitor with an agent that modulates host responses is an appealing strategy precisely because evolving SARS-CoV-2 variants have begun to erode the effectiveness of replication-targeted monotherapy.

To test the concept, the team turned to rhesus macaques, which remain among the most faithful animal models of human COVID-19 because they develop viral pneumonia, radiographic abnormalities, and immune responses that closely mirror clinical disease. Animals were inoculated intratracheally with SARS-CoV-2 and then treated orally for seven days with Carrimycin at 9 milligrams per kilogram, Azvudine at 0.07 milligrams per kilogram, or the two drugs together. The researchers then tracked viral loads, lung pathology, immune responses, and gut microbiota across the treatment groups, conducting the work in an animal biosafety level 3 facility under protocols approved by the institutional animal care committee.

The antiviral results were clear-cut. Both monotherapies significantly inhibited SARS-CoV-2 replication, but the combination produced additive effects, driving viral loads down further in both throat swabs and lung tissue. That pattern matters because viral burden in the lower respiratory tract correlates with disease severity and onward transmission risk. Notably, the authors reported no significant side effects in the treated animals, an important consideration for a combination intended for clinical use, since drug-drug interactions and cumulative toxicity often limit real-world combination regimens.

Lung protection was assessed by chest imaging and histopathology, and here the combination again outperformed either drug alone. Monotherapy reduced ground-glass opacities, the hazy areas on chest scans that reflect fluid and inflammatory infiltration of lung tissue, and mitigated focal interstitial pneumonia, the inflammation of the tissue between air sacs that characterizes severe COVID-19. The combination treatment demonstrated superior efficacy on both measures, suggesting that blunting viral replication while simultaneously damping host inflammation preserves lung architecture more effectively than either intervention alone.

To understand how the combination reshaped the lung environment, the researchers performed transcriptomic profiling and immunofluorescence staining of lung tissue. Gene expression analysis revealed enhanced immunomodulation under combination therapy, including suppression of neutrophil degranulation, a process in which activated neutrophils release enzymes and antimicrobial proteins that, when excessive, damage surrounding tissue and contribute to acute lung injury. The combination also increased populations of CD19-positive B cells and CD3-positive T cells, the cornerstones of adaptive humoral and cellular immunity, while decreasing CD68-positive macrophages, whose accumulation in the lung is associated with sustained inflammation.

At the molecular level, combination therapy downregulated pro-inflammatory and apoptotic markers, pointing to reduced inflammatory signaling and less programmed cell death in infected lung tissue. Taken together, these findings suggest the combination does more than lower viral numbers; it shifts the lung immune landscape away from the maladaptive innate hyperinflammation seen in severe COVID-19 and toward a more effective adaptive response. That distinction is clinically significant, because mortality in severe COVID-19 is driven as much by immunopathology as by the virus itself, and therapies that address both axes have been sought since the beginning of the pandemic.

The study also uncovered a difference between the two drugs that monotherapy comparisons alone would have missed. Carrimycin, but not Azvudine, increased gut bacteria that produce short-chain fatty acids, metabolites with well-documented anti-inflammatory and immune-regulatory effects, and decreased harmful pathogens previously associated with COVID-19 progression. The gut-lung axis, the bidirectional communication between intestinal microbes and respiratory immunity, has emerged as a contributor to COVID-19 outcomes, and dysbiosis has been linked to worse disease. A drug that simultaneously acts on the lung and restores a favorable microbiome composition could therefore offer benefits beyond direct antiviral activity, potentially supporting recovery and reducing secondary complications.

The authors conclude that the Carrimycin-Azvudine combination showed superior efficacy in suppressing viral replication, alleviating lung injury, and correcting immune and inflammatory dysregulation, with Carrimycin providing additional gut microbiota benefits. They position the pairing as a promising therapeutic strategy against COVID-19 and its complications, particularly in a landscape where ongoing viral mutation, emerging resistance mutations, inadequate immunomodulation, and suboptimal organ protection limit existing antiviral options. The work was supported by the National Natural Science Foundation of China, the National Key Research and Development Program of China, and the CAMS Innovation Fund for Medical Sciences.

As with any preclinical animal study, the path from macaques to patients requires clinical validation, including pharmacokinetic confirmation of the doses used, human safety data for the combination, and efficacy trials in infected populations. Nevertheless, the study offers a mechanistically grounded template for next-generation COVID-19 therapy: a direct-acting antiviral paired with an immunomodulatory and microbiome-friendly partner, evaluated with the full toolkit of modern virology, imaging, transcriptomics, and metagenomics. If the additive antiviral and lung-protective effects observed here translate to humans, the combination could address precisely the shortcomings, resistance, inflammation, and organ damage, that have constrained single-drug approaches throughout the pandemic.

Subject of Research: Combination antiviral therapy with Carrimycin and Azvudine against SARS-CoV-2 infection in rhesus macaques

Article Title: Better antiviral and lung-protective effects of Carrimycin in combination with Azvudine in rhesus macaques infected with SARS-CoV-2

Article References: Li, H., Liu, Y., Xue, J., Li, J., Xu, J., Dong, B., Wang, T., Peng, X., Che, Y., Jiang, J., & Peng, Z. (2026). Better antiviral and lung-protective effects of Carrimycin in combination with Azvudine in rhesus macaques infected with SARS-CoV-2. Journal of Translational Medicine. https://doi.org/10.1186/s12967-026-08933-1

Image Credits: AI Generated

DOI: 10.1186/s12967-026-08933-1

Keywords: SARS-CoV-2, Carrimycin, Azvudine, combination therapy, rhesus macaques, lung injury, immunoinflammatory regulation, gut microbiota, antivirals, macrolides, COVID-19, translational medicine

ARDS arises from a heterogeneous set of inciting injuries—pneumonia, sepsis, aspiration, trauma—and produces its hallmark consequences of profound hypoxemia and diffuse lung damage through multiple, overlapping biological pathways. The alveolar-capillary barrier breaks down, protein-rich fluid floods the airspaces, and inflammation cascades across the lung parenchyma. Despite a new global definition of the syndrome published in 2024 and decades of research into targeted therapies, from corticosteroids to statins to interleukin-6 inhibitors, no pharmacological treatment has definitively reversed the underlying injury. What has saved lives is meticulous supportive care: lung-protective mechanical ventilation with low tidal volumes, appropriate positive end-expiratory pressure, attention to driving pressure and mechanical power, and, in selected patients, prone positioning and neuromuscular blockade. Sedation sits at the heart of that supportive framework, because mechanically ventilated patients with ARDS typically require deep sedation to tolerate the ventilator and to avoid self-inflicted lung injury from vigorous, asynchronous breathing efforts.

It is precisely here that volatile anesthetics promised something special. According to the review, these agents were proposed to achieve two aims simultaneously: they could provide effective, titratable sedation while also protecting against inflammatory lung injury. Preclinical work has been remarkably rich. Experimental studies have shown that volatile agents modulate immune cell function, dampen the release of inflammatory mediators, preserve the integrity of epithelial tight junctions that hold the alveolar barrier together, and promote alveolar epithelial wound healing. More recent laboratory work suggests prolonged antibacterial, anti-inflammatory, and surfactant-promoting effects, and in vitro studies have explored how sevoflurane, propofol, and opioids differentially shape the endothelial proinflammatory response. In surgical populations, meta-analyses have examined whether volatile anesthesia reduces postoperative pulmonary complications compared with total intravenous anesthesia, with results that kept the lung-protective hypothesis alive.

The respiratory effects of volatile agents added a second layer of appeal. Unlike most intravenous sedatives, sevoflurane and isoflurane are bronchodilators, which has made them a rescue therapy for life-threatening status asthmaticus when conventional treatment fails. Even more intriguingly, animal studies suggest that volatile anesthetics interact with central respiratory chemoreceptor neurons in ways that help maintain breathing drive during anesthesia—activating leak sodium conductances in retrotrapezoid nucleus neurons and modulating background potassium currents. For ARDS patients, preserving respiratory drive matters enormously. Deep intravenous sedation with propofol or midazolam suppresses spontaneous breathing, which can be protective in the earliest phase of lung injury but becomes a liability later, contributing to diaphragm atrophy and prolonged ventilation. The concept of lung-protective and diaphragm-protective sedation—precision sedation that balances patient effort against ventilator-induced injury—has become a major research frontier, and volatile agents were seen as natural candidates for it.

Early clinical data seemed to vindicate the enthusiasm. A randomized controlled pilot study published in 2017 by Jabaudon and colleagues found that sevoflurane sedation in ARDS patients reduced inflammatory mediators and improved oxygenation. Observational and feasibility studies explored whether volatile sedation could allow spontaneous breathing even during prone positioning or continuous lateral rotational therapy—situations where conventional sedation typically demands paralysis or deep unconsciousness. A large phase III non-inferiority trial in Germany and Slovenia compared inhaled isoflurane, delivered via an anesthetic conserving device, with propofol in invasively ventilated ICU patients and found the inhaled approach a viable alternative. Substudies examined the physiology in detail, including whether the devices used to deliver volatile agents add dead space that increases mechanical power, with recent work suggesting that low dead space reflectors do not increase mechanical power compared with standard heat and moisture exchangers.

Then came the trial that changed the conversation. The SESAR randomized clinical trial, published in JAMA in 2025 by Jabaudon and colleagues, enrolled patients with moderate-to-severe ARDS and compared inhaled sevoflurane sedation with standard intravenous propofol. The results ran counter to expectations: sevoflurane sedation reduced ventilator-free days at day 28 and increased mortality compared with propofol. For a field that had spent years building the mechanistic case for inhaled lung protection, the finding was a genuine shock. The review’s authors treat the result with appropriate seriousness, and it anchors their central recommendation: pending further high-quality data suggesting benefit, routine clinical use of volatile ICU sedation in ARDS is currently not recommended outside of clinical trials.

Why might a therapy with such compelling biology fail in the clinic? The review points to several open questions that future research must resolve. Dose is one: the concentrations of sevoflurane used for prolonged ICU sedation may differ meaningfully from the exposures that showed benefit in experimental models, and the therapeutic window between anti-inflammatory protection and harm remains poorly mapped. Agent selection is another—sevoflurane and isoflurane have distinct pharmacological profiles, and results with one cannot simply be extrapolated to the other. Duration of sedation is a third variable; the timing and length of volatile exposure could determine whether the drug protects or injures the healing lung. Perhaps most tantalizing is the question of heterogeneity of treatment effect across ARDS sub-phenotypes. ARDS is not one disease but a syndrome with inflammatory and non-inflammatory biological clusters, and a therapy that dampens inflammation might help hyperinflammatory patients while harming others. Precision-medicine approaches that stratify patients by sub-phenotype could yet rescue the volatile hypothesis.

The trial landscape remains active, even if no ongoing or recently completed studies are being conducted solely in ARDS patients. The SAVE-ICU trial is enrolling patients with COVID-19 and non-COVID-19 acute hypoxemic respiratory failure. The French INASED trial is testing inhaled sedation more broadly in the ICU. The INSPiRE-ICU1 and INSPiRE-ICU2 trials, sponsored by Sedana Medical and led from North American centers, are comparing inhaled sedation with propofol in respiratory failure. A 2025 meta-analysis of randomized trials of volatile sedation in mechanically ventilated critically ill adults, along with a 2026 systematic review focused specifically on inhaled versus intravenous sedation in ARDS, will help synthesize the accumulating evidence. Beyond efficacy, practical considerations loom: delivery devices add circuit complexity, environmental concerns about anesthetic gas emissions are mounting, and drug shortages have at times made inhaled sedation an unexpectedly useful fallback.

The story of volatile anesthetics in ARDS is, in the end, a story about how modern critical care science works. Mechanistic plausibility, preclinical elegance, and promising pilot data are necessary but not sufficient; only large, well-designed randomized trials can establish whether a therapy helps or harms. The SESAR trial delivered an unwelcome answer for sevoflurane in moderate-to-severe ARDS, and the review’s authors have responded not by abandoning the idea but by sharpening the questions—dose, agent, duration, and patient sub-phenotype—that will determine whether inhaled sedation earns a place in the ARDS armamentarium. For now, patients with ARDS should receive sedation according to established guidelines, and volatile agents should remain within the boundaries of clinical trials. The lungs of the sickest patients depend on that discipline, and the next generation of trials will tell us whether the operating room’s most trusted anesthetics can ever make the same claim in the intensive care unit.

Subject of Research: Volatile anesthetic sedation as a potential lung-protective therapy in acute respiratory distress syndrome

Article Title: Volatile anesthetic sedation in acute respiratory distress syndrome

Article References: O’Gara, B., Boncyk, C., Müller Wirtz, L. M., Molano Franco, D., Kotani, Y., Landoni, G., Jerath, A., L’Her, E., Bellgardt, M., Becher, T., Beck-Schimmer, B., Beitler, J. R., Constantin, J. M., Hughes, C. G., Meiser, A., & Jabaudon, M. (2026). Volatile anesthetic sedation in acute respiratory distress syndrome. Intensive Care Medicine. https://doi.org/10.1007/s00134-026-08613-0

Image Credits: AI Generated

DOI: 10.1007/s00134-026-08613-0

Keywords: acute respiratory distress syndrome, volatile anesthetics, sevoflurane, isoflurane, ICU sedation, mechanical ventilation, lung injury, inflammation, SESAR trial, propofol, lung-protective ventilation, critical care

The research team, working at the Laboratory Animal Center of Shanghai University of Traditional Chinese Medicine, set out to answer two linked questions. First, could they establish a stable and reproducible rat model of lung injury driven by myocardial ischemia and reperfusion? Second, could pretreatment with electroacupuncture reduce that injury, and if so, did the HMGB1/RAGE pathway, a pair of molecules long implicated in acute lung inflammation, sit at the center of the mechanism? Their answer to both questions, based on a series of five carefully controlled experiments in male Sprague-Dawley rats, was yes.

Building the model required calibrating the injury. The researchers ligated the left anterior descending coronary artery in anesthetized rats for 30 minutes, 45 minutes, or one hour, then released the snare to allow 24 hours of reperfusion, confirming ischemia by visible cyanosis of the ventricular wall and ST-segment elevation on the electrocardiogram. Only the one-hour ischemia protocol produced consistent, measurable lung damage. In those animals, arterial oxygen partial pressure and the oxygenation index fell significantly, the alveolar-arterial oxygen gradient rose, and the lung wet-to-dry weight ratio, a standard gauge of pulmonary edema, climbed sharply. Under the microscope, the lungs showed alveolar collapse, hemorrhage, thickened septa, and dense inflammatory infiltration, and immunostaining revealed abundant cleaved caspase-3, a hallmark of apoptosis. Shorter ischemic periods produced weaker or statistically insignificant changes, establishing one hour of ischemia followed by 24 hours of reperfusion as the reliable model.

With the model in hand, the team turned to electroacupuncture. They stimulated two classical acupoints, Zusanli (ST36) on the hind limb and Feishu (BL13) on the back near the lungs, using a 2/20 Hz dense-disperse waveform for 30 minutes per session. The critical variable was timing. A single 30-minute session immediately before ischemia did essentially nothing: blood gas values, edema measures, injury scores, and apoptotic cell counts in that group were indistinguishable from the untreated ischemia-reperfusion group. But when the same stimulation was repeated over three consecutive days before the procedure, the picture changed dramatically. Oxygenation improved, the wet-to-dry ratio dropped, lung injury scores fell, and cleaved caspase-3 staining diminished significantly compared with injured animals that received no pretreatment.

The protective effect was accompanied by a clear anti-inflammatory signature. Quantitative PCR showed that ischemia-reperfusion drove up the messenger RNA of the pro-inflammatory cytokines IL-1β and IL-6 and the chemokines CXCL1 and CXCL2 in lung tissue. Three days of electroacupuncture pretreatment significantly reduced all four transcripts at four hours of reperfusion, with IL-6 and CXCL1 still suppressed at 24 hours. Immunohistochemistry told a parallel story at the cellular level: myeloperoxidase-positive neutrophils and F4/80-positive macrophages, the two dominant infiltrating populations, flooded the injured lungs after reperfusion but were markedly fewer in the pretreated animals at both early and late time points.

The molecular centerpiece of the study was HMGB1, a nuclear non-histone protein that escapes from stressed cells and acts as a danger signal when it binds transmembrane receptors, most notably RAGE and the Toll-like receptors. Western blotting and PCR revealed that ischemia-reperfusion significantly increased both HMGB1 and RAGE in lung tissue, and electroacupuncture pretreatment brought both back down at four and 24 hours of reperfusion. Because HMGB1 is known to recruit and activate inflammatory cells in many forms of acute lung injury, the authors reasoned that this axis could be the plausible bridge between the systemic inflammatory surge triggered by cardiac ischemia and the pulmonary damage that follows.

A key question was where the lung HMGB1 actually came from. The injured heart itself is an obvious suspect. Yet when the researchers measured HMGB1 expression in heart tissue, they found it elevated only in the earliest phase of inflammation and essentially normal by 24 hours of reperfusion, precisely when lung HMGB1 remained high. Moreover, electroacupuncture reduced lung HMGB1 without changing myocardial infarct size, measured by triphenyltetrazolium chloride staining, indicating that the treatment was not simply shrinking the cardiac wound and thereby sending fewer danger signals. The accumulating HMGB1 in the lungs, the data suggested, was generated locally rather than imported from the heart.

To test causality more directly, the team delivered recombinant HMGB1 protein directly into the lungs via intubation-mediated intratracheal administration before reperfusion. Adding the protein to injured animals worsened respiratory dysfunction, edema, and histological injury to some degree. More tellingly, in rats that had received the three-day electroacupuncture pretreatment, intratracheal recombinant HMGB1 significantly raised lung HMGB1 and RAGE expression, lowered oxygenation indices, increased the wet-to-dry ratio, worsened injury scores, and boosted apoptotic cell counts. In other words, flooding the lungs with the very molecule the therapy suppresses partially reversed its benefits, evidence that HMGB1 is not merely a bystander but a functional target of the electroacupuncture effect.

The authors are candid about the limits of their work. The validation relied on recombinant protein challenge rather than genetic knockout, which leaves some causal uncertainty, and the sample sizes were small, with five rats per group. All experiments were conducted in male animals, and no clinical data exist yet to confirm that the findings translate to patients awaiting cardiac surgery. Larger, multicenter human studies will be needed before electroacupuncture pretreatment can be recommended as a standard element of perioperative lung protection.

Even so, the study adds a compelling piece to a growing body of evidence that neuromodulation through acupuncture-like stimulation can precondition distant organs against surgical stress. Previous work has shown electroacupuncture protecting the lungs during cardiopulmonary bypass by dampening inflammasome activation and oxidative stress pathways, and the new findings extend that logic to the specific HMGB1/RAGE axis in the setting of myocardial ischemia and reperfusion. If the mechanism holds in humans, a low-side-effect intervention delivered in the days before surgery could help reduce the burden of postoperative pulmonary complications, aligning with the principles of enhanced recovery after surgery and broadening the toolkit of perioperative organ protection.

Subject of Research: Electroacupuncture pretreatment and protection against myocardial ischemia/reperfusion-induced lung injury via the HMGB1/RAGE pathway in rats

Article Title: Electroacupuncture pretreatment alleviates myocardial ischemia/reperfusion‐induced lung injury by inhibiting the expression of HMGB1/RAGE in male rats

Article References: Xie, C., Zhang, J., Zhang, Y., Chi, H., Yong, Y., & Song, J. (2026). Electroacupuncture pretreatment alleviates myocardial ischemia/reperfusion‐induced lung injury by inhibiting the expression of HMGB1 / RAGE in male rats. Physiological Reports, 14(18), Article e71066. https://doi.org/10.14814/phy2.71066

Image Credits: AI Generated

DOI: 10.14814/phy2.71066

Keywords: electroacupuncture, myocardial ischemia-reperfusion, lung injury, HMGB1, RAGE, inflammation, acute lung injury, cardiac surgery, pulmonary complications, rat model, preconditioning, enhanced recovery after surgery

The research, led by Zhenfang Shan, Jieqiong Li, and Zhaohui Tong of Beijing Chao-Yang Hospital, Capital Medical University, took a proteomics approach—measuring large panels of proteins in plasma rather than relying on clinical scores alone. The team analyzed plasma samples from 196 patients with ARDS, 100 pulmonary patients who did not have ARDS, and 100 healthy controls. Using mass spectrometry-based profiling and statistical tools including partial least squares-discriminant analysis, the researchers searched for proteins that consistently separated ARDS patients from the comparison groups.

The signal that emerged was striking. Pathways related to the proteasome—the cellular machine that shreds damaged or unwanted proteins into small peptides—were significantly activated in ARDS patients. Of particular interest was the immunoproteasome, a specialized version of the proteasome found in immune cells that processes proteins for presentation to the immune system. Rather than a single protein, the researchers found that a panel of seven immunoproteasome subunits collectively carried a robust diagnostic fingerprint of the syndrome.

To turn that observation into a practical tool, the team built a diagnostic model using LASSO regression, a machine learning technique that selects the most informative predictors while guarding against overfitting. Trained on 277 samples, the seven-subunit panel achieved an area under the receiver operating characteristic curve (AUC) of 0.908, indicating strong discriminatory power. Critically, the model held up in an independent validation cohort of 119 samples, where it achieved an AUC of 0.890. That kind of consistency across separate cohorts is what separates promising biomarkers from statistical artifacts, and it suggests the panel could distinguish ARDS from other serious lung conditions at the bedside.

The researchers did not stop at diagnosis. They traced where the biomarkers came from, examining bronchoalveolar lavage fluid—the liquid sampled from deep within the lungs of patients—and confirming that the proteasome signature reflected genuine biological activity in the injured lung rather than a distant systemic echo. They then moved into an animal model, inducing ARDS-like lung injury in mice with lipopolysaccharide, a component of bacterial cell walls that triggers intense inflammation.

In the mouse model, one subunit stood out: PSMB8, also known as the low molecular mass polypeptide 7 or LMP7, a catalytic subunit unique to the immunoproteasome. PSMB8 expression was upregulated in lung tissue after injury, and single-cell and lineage analyses indicated that the protein was produced primarily by monocytes and macrophages—the scavenger immune cells that swarm into inflamed lungs and often drive much of the collateral tissue damage. The degree of PSMB8 elevation correlated with disease severity, tying the molecular marker to clinical outcomes.

The therapeutic experiments were the most consequential part of the study. When the researchers inhibited PSMB8 pharmacologically, or deleted the Psmb8 gene in mice, the results were consistent: lung injury was reduced, inflammation was blunted, and respiratory dysfunction improved. Measurements of lung mechanics, including resistance and compliance, along with wet-to-dry weight ratios that quantify fluid accumulation in the lung, all pointed toward meaningful protection when the immunoproteasome subunit was removed from the picture.

The mechanism behind that protection appears to lie in macrophage behavior. PSMB8 deficiency suppressed M1-like macrophage polarization—the pro-inflammatory state that macrophages adopt when they are pumping out cytokines and reactive molecules that, while meant to fight pathogens, can devastate surrounding tissue. Intriguingly, the researchers found that this shift was accompanied by alterations in lipid metabolic pathways, hinting that the immunoproteasome influences not just protein degradation but also the metabolic programming that determines whether macrophages soothe or scorch the lung.

The implications are twofold. Diagnostically, a blood test built on seven proteasome subunits could complement existing tools such as the Sequential Organ Failure Assessment and APACHE II scores, offering an objective, biologically grounded way to identify ARDS early—potentially before patients require invasive mechanical ventilation. Therapeutically, PSMB8 joins a growing list of immune-focused targets for a syndrome that currently lacks a specific drug; treatment today is largely supportive, centered on ventilator management and care of the underlying cause.

Caveats remain. The therapeutic results come from a preclinical mouse model, and the authors themselves emphasize that PSMB8 is a promising but still preclinically validated target that warrants further investigation. Translating proteasome inhibition into safe human therapy will require careful work, since the immunoproteasome plays normal roles in immune surveillance. Still, the convergence of a clinically validated biomarker panel with a mechanistically supported drug target—grounded in more than 300 patient samples and confirmed in animal studies—represents an unusually coherent translational package for a syndrome that has long resisted both early detection and targeted treatment.

Subject of Research: A proteasome subunit-based biomarker panel for early diagnosis of acute respiratory distress syndrome and therapeutic targeting of PSMB8

Article Title: Proteasome subunit-based biomarker panel for early diagnosis of acute respiratory distress syndrome and therapeutic targeting of PSMB8 in a mouse model

Article References: Shan, Z., Zhang, H., Ma, J., Gou, Y., Li, J., & Tong, Z. (2026). Proteasome subunit-based biomarker panel for early diagnosis of acute respiratory distress syndrome and therapeutic targeting of PSMB8 in a mouse model. Journal of Translational Medicine. https://doi.org/10.1186/s12967-026-08645-6

Image Credits: AI Generated

DOI: 10.1186/s12967-026-08645-6

Keywords: ARDS, biomarkers, proteasome, immunoproteasome, PSMB8, macrophage polarization, plasma proteomics, LASSO regression, lung injury, intensive care, diagnostic panel, lipopolysaccharide mouse model

Haematitum occupies an unusual place in the Chinese Materia Medica. Classified as a mineral-based medicine rather than a plant or animal product, it is used clinically as a hemostatic and antiemetic, and classical texts warn that it should not be taken for long stretches. Modern toxicology has largely confirmed those warnings, documenting lung toxicity in both animal models and clinical observations, but the underlying biology has remained murky. Toxicity studies of mineral medicines often stop at the tissue level, leaving open the question of which cells fail first and which molecular signals carry the injury from one organ system to another.

To answer those questions, the researchers established a mouse model of Haematitum-induced lung injury and then interrogated it with three complementary technologies. Sixteen S ribosomal RNA sequencing mapped shifts in the gut bacterial community, untargeted metabolomics catalogued the small molecules accumulating in lung tissue, and single-cell RNA sequencing constructed a comprehensive atlas of the lung’s cellular landscape, capturing the gene-expression signatures of every major cell type simultaneously. This combined approach allowed the team to connect events at three scales at once: the microbial ecosystem of the intestine, the metabolic chemistry of the lung, and the behavior of individual immune cells within it.

The first domino to fall, according to the data, is the intestinal barrier. Mice receiving high-dose Haematitum showed clear disruption of the gut lining, the selective wall of epithelial cells that normally confines the trillions of microbes in the intestine while allowing nutrients to pass. With that wall compromised, the composition of the microbiome shifted dramatically, and the relative abundance of Klebsiella, an opportunistic bacterial genus notorious for its role in hospital-acquired infections, rose sharply. Microbial metabolites that should have remained sealed within the bowel began entering the bloodstream, hitching a ride through the circulation toward distant organs, including the lungs.

Once those metabolites reached the lung, correlation analysis revealed a striking statistical association between gut dysbiosis and disturbances in a single metabolic network: the glycerophospholipid pathway. Glycerophospholipids are the phospholipid building blocks of cellular membranes and the constituents of pulmonary surfactant, the fatty film that keeps the air sacs of the lung from collapsing. Disruption of this pathway implies that the injured lung was not merely inflamed but was also losing the lipid machinery required for structural integrity and normal immune signaling, creating a metabolically destabilized environment in which immune cells were primed to misfire.

The single-cell data then identified the two cell types at the center of the injury: macrophages and neutrophils. Macrophages, the lung’s resident sentinels, normally enforce calm by patrolling the tissue and suppressing excessive inflammation. The sequencing showed that the PPAR signaling pathway in these macrophages had been inhibited. PPAR, or peroxisome proliferator-activated receptor, is a nuclear receptor that regulates lipid metabolism and anti-inflammatory gene programs; when its activity drops, macrophages lose their anti-inflammatory identity. In the Haematitum-exposed mice, the silenced macrophages began releasing inflammatory factors, most notably tumor necrosis factor-alpha, a potent pro-inflammatory cytokine that functions as a broadcast alarm to the rest of the immune system.

TNF-alpha, in this model, acted as the messenger that recruited and reshaped the second cast member. Colocalization experiments confirmed the spatial relationship between macrophages and the cytokine, while the single-cell analysis showed that neutrophils exposed to the signal activated their own TNF signaling pathway. Neutrophils are the immune system’s shock troops, short-lived cells packed with destructive enzymes and reactive chemicals designed to annihilate pathogens. When appropriately activated, they are lifesavers; when triggered inappropriately, they shred healthy tissue. Under the influence of macrophage-derived TNF-alpha, the neutrophils in the injured lungs acquired what the authors describe as a highly destructive phenotype, and the synergy between the two cell types drove both inflammation and apoptosis, or programmed cell death, across the lung tissue.

Crucially, the team did not stop at correlation. By pharmacologically manipulating the axis they had identified, administering a PPAR-gamma agonist to restore the macrophage pathway, or a TNF-alpha inhibitor to block the cytokine signal, they showed that cellular abnormalities could be effectively reversed and lung injury significantly alleviated. That interventional rescue is the strongest evidence that the PPAR-gamma/TNF-alpha axis is not merely a bystander in the toxicity but its functional core. It also immediately suggests a therapeutic strategy: drugs that prop up anti-inflammatory macrophage programs or mop up excess TNF-alpha could, in principle, mitigate the pulmonary side effects of prolonged mineral medicine use.

The study also offered a solution rooted in the tradition itself. Haematitum is classically paired with Inula japonica Thunb., a flowering herb used in combination formulas for respiratory complaints, and the researchers evaluated this pairing in their model. The combination reduced lung toxicity, and computational prediction suggested that components within Inula japonica act as natural PPAR-gamma agonists, effectively replenishing the very pathway that Haematitum suppresses. Meanwhile, mice that received Haematitum at a common clinical dose rather than a high dose avoided the severe cascade altogether, reinforcing the traditional dosing guidance and suggesting that the toxicity is dose-dependent rather than intrinsic at all exposure levels.

Beyond its immediate implications for one traditional medicine, the work carries broader lessons for the toxicology of mineral-based drugs and for the rapidly growing field of gut-lung axis research. It demonstrates that organ toxicity can originate far from the organ that suffers it, with a disrupted intestinal barrier serving as the gateway for circulating microbial metabolites that rewire metabolism and immunity elsewhere in the body. It also provides a template for how single-cell transcriptomics, metabolomics, and microbiome sequencing can be braided together to resolve multi-organ toxicity mechanisms that no single technology could untangle alone. For clinicians and regulators weighing the safety of mineral medicines, the message is concrete: protect the gut, respect the dose, and watch the PPAR-gamma/TNF-alpha axis as a biomarker of trouble ahead. The authors note that these findings advance understanding of mineral medicine toxicology and offer a reference framework for the safe clinical application of traditional Chinese medicines whose ancient warnings, it turns out, described a molecular pathway that modern science has only now begun to read.

Subject of Research: Mechanism of Haematitum-induced lung injury mediated by gut dysbiosis and macrophage-neutrophil crosstalk along the gut-lung axis

Article Title: Single-cell transcriptomics reveals macrophage-neutrophil crosstalk in Haematitum-induced lung injury associated with gut dysbiosis

Article References: Lu, M., Zhu, H., Peng, Y., Zhu, S., Huang, B., & Cao, Y. (2026). Single-cell transcriptomics reveals macrophage-neutrophil crosstalk in Haematitum-induced lung injury associated with gut dysbiosis. Journal of Translational Medicine. https://doi.org/10.1186/s12967-026-08954-w

Image Credits: AI Generated

DOI: 10.1186/s12967-026-08954-w

Keywords: Haematitum, gut-lung axis, gut dysbiosis, Klebsiella, macrophages, neutrophils, TNF-alpha, PPAR signaling, glycerophospholipid metabolism, single-cell RNA sequencing, traditional Chinese medicine, lung injury