Writing in the journal New Microbes and New Infections, a team led by researchers at the CSIR Institute of Genomics and Integrative Biology and Max Hospital in New Delhi reports a whole-blood transcriptomic analysis of 112 dengue-positive patients recruited at their first hospital visit. The participants were classified according to the revised 2009 WHO guidelines into those without warning signs and those with warning signs, the latter defined by coagulation abnormalities such as thrombocytopenia, clinical fluid accumulation reflected in hemoconcentration, and increased vascular fragility. Within the group without warning signs, 46 patients also presented with leukopenia, allowing the investigators to stratify the cohort into mild, moderate and relatively severe subgroups. Although none of the patients met the formal criteria for severe dengue, the 21 patients carrying warning signs together with thrombocytopenia were treated as demonstrating a propensity for clinically severe outcomes because of their depressed platelet counts.

The technical pipeline behind the study was considerable. The team isolated RNA from one milliliter of whole blood per patient, depleted globin and ribosomal RNA, and generated stranded sequencing libraries that were run as paired-end 151-base-pair reads on an Illumina NextSeq 2000 platform. The effort produced more than two billion reads, averaging about 18.5 million reads per sample. After quality trimming and quasi-mapping to the human transcriptome, differential expression was computed with DESeq2, and confounder analyses for age and sex showed no significant differences between the clinical groups. All 112 patients experienced primary dengue infection, and serotype analysis based on viral reads recovered from the sequencing data indicated that the majority were infected with DENV-2, consistent with the serotype circulating in Delhi during the study period. Samples were collected during the acute febrile phase, with a mean of 3.69 days of fever at enrollment.

The clinical chemistry told a coherent story before any sequencing was considered. Total leukocyte counts, platelets, lymphocytes and neutrophils all differed significantly between the groups, with p-values below 0.001. The two leukopenic groups showed lower neutrophil and higher lymphocyte values than the mild group, a pattern the authors interpret as a subdued first-line defense, since neutrophils are the earliest active killers of pathogens during viral and bacterial infections. Notably, hematocrit was not elevated in the patients with warning signs, suggesting that capillary leak had not yet begun at the time of sampling. Liver function tests available for a subset of patients showed higher SGOT and SGPT values in the warning-sign group, along with significantly lower total protein and elevated bilirubin, although all values remained within normal ranges, hinting at hepatic derangement that was only beginning to emerge.

Differential expression analysis between the moderate and mild groups yielded 15 significantly downregulated genes, most of them involved in immune response and inflammation, including the chemokine CXCL2, the neutrophil marker CD177, the acute-phase protein ORM1 and the inflammation regulator PI3. The authors read this as evidence of a subdued immune response in moderate patients compared with mild ones. By contrast, comparisons involving the severe group were far more dramatic: severe versus mild produced 215 upregulated and 92 downregulated genes, while severe versus moderate produced 142 upregulated and only 2 downregulated genes. Pathway enrichment against the Reactome database showed that upregulated functions in severe patients centered on glycosylation and the nervous system, whereas downregulated pathways encompassed immune and inflammatory response, GPCR signaling, platelet activation and aggregation, and prostaglandin synthesis in platelets and endothelial cells.

One of the most intriguing findings was that, although many immune response genes were downregulated in severe patients, a diverse repertoire of B cell receptor genes, including immunoglobulin light and heavy chain variables, was upregulated, indicating an acute antibody response associated with severity. Upregulation of KIR3DL3, LILRB5 and IRAK1BP1 appeared to divert innate immune pathways toward resolution of inflammation. Taken together, the differential expression profile suggests an attenuation of immune and inflammatory activity in severe patients precisely at the time when platelet counts fall below normal thresholds due to platelet dysfunction, a counterintuitive pattern that complicates the traditional picture of dengue severity as a cytokine-driven hyperinflammatory state.

To move beyond lists of individual genes, the team applied Weighted Gene Co-expression Network Analysis, or WGCNA, to 14,071 genes across all 112 samples. After selecting an optimal soft-threshold power to ensure scale-free network topology, the algorithm organized the genes into 22 modules, each representing a set of genes with highly similar expression patterns. The severe subgroup split into two major clades with starkly different co-expression patterns: clade 1 modules showed higher expression in severe patients and were enriched for metabolism, glycosylation, nervous system processes and DNA repair, while clade 2 modules showed decreased expression and carried functions related to blood coagulation, platelet activation, cell adhesion, immune response, regulation of virus replication, interferon response and cytokine signaling. Correlating module eigengenes with clinical parameters revealed that clade 2 modules correlated positively with platelet counts, while a single module, turquoise, correlated negatively, reinforcing the link between immune response modules and platelet dysregulation. Total leukocyte count, by contrast, showed no significant correlation with any module.

Within the platelet-associated modules, the investigators identified a set of genes that collectively define the severe state. The greenyellow module contained interferon pathway genes such as IFI44L, IFI35, OAS1, SAMD9L and KAT2B, while the darkred module harbored genes governing platelet function, coagulation and endothelial integrity, including ARHGEF12, CTTN, SELP, PPBP, PRKAR2B and F13A1. Other modules captured vesicular trafficking genes such as GOLGA7 and RAB27B, thought to be required for viral replication and autophagy, and innate antiviral genes including IFIH1, which encodes the cytosolic RNA sensor MDA5, and HNRNPA2B1. When the team dichotomized the severe patients by platelet count, comparing those below 100 times 10 to the ninth per liter with those between 100 and 140, 16 genes showed significant differences in baseline transcript abundance, with IFI44L standing out at a difference of more than 800 counts per million. Regression analysis found no genes significantly correlated with SGOT, implying that modest transaminase elevations do not substantially shape disease outcome.

The findings converge with transcriptomic studies of dengue patients in Brazil, where interferon-stimulated genes such as IFI27 and ISG15 emerged as biomarkers capable of distinguishing dengue hemorrhagic fever from uncomplicated dengue during the late acute phase. Although IFI27 was not captured in the Indian dataset, ISG15 was consistently upregulated in patients with warning signs and low platelets, aligning with its proposed role as a severity marker. The Indian study also detected CTTN, a gene tied to endothelial barrier function that was not a focus of the Brazilian datasets, hinting at population-specific elements of the immune-endothelial axis. The authors propose a sequential pathogenic cascade for patients with warning signs: a suboptimal early interferon and innate immune response weakens host defenses and permits viral replication, heightened viral stress drives platelet dysfunction and clearance, and, independently of cytokine-mediated hyperinflammation, upregulation of O-linked glycosylation genes such as GALNT13, B4GALT1 and B3GNT4 alongside downregulation of structural genes like CTTN alters the endothelial glycocalyx, producing the vascular permeability that characterizes the onset of clinical warning signs.

The study carries the inherent limitation of a cross-sectional design, since blood was drawn at a single acute-phase time point, and whole-blood RNA means the observed signatures may partly reflect shifts in circulating cell composition rather than purely transcriptional changes within individual cell types. The authors note that single-cell transcriptomics or computational deconvolution in future longitudinal cohorts would help resolve cell-type-specific contributions. Even so, the work suggests practical avenues: monitoring glycocalyx-related gene signatures could enable early identification of patients at risk of severe disease, and therapeutic strategies aimed at preserving glycocalyx integrity may offer a novel way to reduce vascular complications. If validated across larger and more geographically diverse cohorts, the interferon and glycosylation signatures identified here could become molecular biomarkers for predicting, and perhaps mitigating, severe dengue before the first warning signs appear.

Subject of Research: Host transcriptomic signatures associated with severe dengue infection in Indian patients

Article Title: Interferon gamma and inflammatory response genes by weighted gene co-expression network analysis reveal significant associations with severe dengue infection in India

Article References: Shamim, U., Arora, S., Maurya, R., Soni, J., Shukla, R., Mehta, P., Tarai, B., Budhiraja, S., & Pandey, R. (2026). Interferon gamma and inflammatory response genes by weighted gene co-expression network analysis reveal significant associations with severe dengue infection in India. New Microbes and New Infections, 74, Article 101855. https://doi.org/10.1016/j.nmni.2026.101855

Image Credits: AI Generated

DOI: 10.1016/j.nmni.2026.101855

Keywords: dengue, DENV-2, interferon, WGCNA, transcriptomics, thrombocytopenia, endothelial glycocalyx, glycosylation, innate immunity, biomarkers, India, vascular leakage

The case for that shift rests on a fundamental biological reality: sepsis is not one disease. It is a syndrome of dysregulated host responses to infection, and in children this heterogeneity is particularly striking. Different pathogens activate fundamentally different immune cascades, from novel respiratory viruses such as influenza and respiratory syncytial virus to diverse Gram-negative and Gram-positive bacteria and fungi. Layered on top of this pathogen diversity are individual genetic polymorphisms that make each child’s initial response drastically different. Using peripheral blood RNA transcriptomic sequencing, international research teams have identified distinct sepsis response signatures, including the SRS1 and SRS2 endotypes, revealing a highly polarized biological spectrum hiding behind a single clinical label.

The divergence does not stop at molecular signatures. Some patients present early with a hyperinflammatory endotype, the so-called cytokine storm, driving widespread systemic endothelial activation and a surge in vascular permeability. Others, especially neonates or children with underlying immunodeficiencies, rapidly slide into the opposite state: a hypoinflammatory or immunoparalyzed endotype characterized by leukocyte reprogramming and global mitochondrial bioenergetic failure. Big data approaches and unsupervised machine learning algorithms such as latent class analysis have confirmed that pediatric sepsis comprises distinctly different severe sub-phenotypes, including shock-dominant forms, multiorgan dysfunction syndrome, and hyperferritinemic or macrophage activation-like syndromes. Two children with identical sepsis diagnoses may therefore harbor completely antithetical underlying host responses and mechanisms of injury.

Meanwhile, the way acute kidney injury itself is diagnosed is under intense scrutiny. For decades, staging has relied almost entirely on the Kidney Disease: Improving Global Outcomes criteria, based on elevated serum creatinine and decreased urine output. But these are crude functional filtration markers that lack microstructural pathological granularity. In pediatric critical care, baseline creatinine varies widely by age, developmental stage, sex, and muscle mass, and it rises with a significant physiological lag after renal injury. Early fluid resuscitation compounds the problem: pathological fluid accumulation and fluid overload dilute serum creatinine, frequently masking or delaying a timely diagnosis. Static urine output assessments, the editorial notes, fail to integrate mass balance and the actual fluid dynamics of the patient. Notably, the newly published KDIGO 2026 draft guidelines explicitly advocate incorporating novel structural and stress biomarkers alongside traditional functional metrics to redefine acute kidney injury and recognize subclinical structural damage before function declines.

The kidney itself is far from a uniform organ. Anatomically it is divided into cortex, outer medulla, and inner medulla, each with radically different vulnerabilities. The cortex receives abundant blood flow and drives filtration, whereas the medulla receives less than ten percent of total renal blood flow, and its specialized vasa recta countercurrent multiplier system leaves it naturally on the brink of hypoxia. In sepsis, systemic hemodynamic redistribution often produces severe, occult hypoxia in the renal medulla that standard monitoring never sees. The organ contains more than thirty distinct cell types, including glomerular endothelial cells, podocytes, and proximal and distal tubular epithelial cells, each reacting uniquely to circulating inflammatory cytokines, endotoxins, and damage-associated molecular patterns. The proximal tubule, particularly the S3 segment, is highly metabolically active and dependent on mitochondrial oxidative phosphorylation, making it the epicenter of structural damage.

Single-cell technologies have pushed this anatomical insight to a molecular level. Single-cell RNA sequencing shows that metabolically active proximal tubular cells and distinct nephron segments, such as the loop of Henle, follow divergent gene reprogramming and injury pathways during sepsis. Critically, two pediatric patients meeting identical KDIGO stage 3 criteria may harbor diametrically opposed internal microenvironments. One may experience a transient, functional alteration driven by relative volume deficit, rapidly reversible with titrated fluid resuscitation. The other may suffer persistent, damage-associated injury marked by acute tubular necrosis, severe microvascular endothelial barrier disruption, and widespread apoptosis. Expanding on initial adult cohorts, recent pediatric critical care research has validated distinct biological sub-phenotypes of acute kidney injury in critically ill children, including low-inflammatory/mild injury and hyperinflammatory/endothelial injury groups, whose clinical trajectories, renal recovery probabilities, and long-term mortality risks are fundamentally disparate.

When systemic sepsis heterogeneity intersects with organ-level microenvironmental heterogeneity, the kidney becomes both a passive target of the immune storm and an active amplifier of inflammation and microcirculatory breakdown. Modern pathophysiological research shows that hyperinflammatory sepsis triggers widespread shedding and degradation of the vascular endothelial glycocalyx, the protective sugar-rich coating of blood vessels. Stripped of this layer, the microvascular endothelium exposes adhesion molecules, prompting neutrophils and platelets to aggregate, adhere, and roll along renal microvascular walls, producing severe spatial mismatching of capillary blood flow and localized microthrombi. This explains the dissociation between macrocirculation and microcirculatory tissue perfusion: even when systemic blood pressure is normalized and total renal blood flow preserved or increased, local renal microvessels remain trapped in severe, occult tissue hypoxia. To survive, tubular epithelial cells initiate gene reprogramming and metabolic downregulation, entering a protective, cell-cycle-arrested quiescent state.

This structure-function mismatch, the authors argue, is precisely why past large-scale trials in sepsis-associated kidney injury overwhelmingly failed: interventions were applied uniformly across broad clinical syndromes, ignoring the distinct biological sub-phenotypes of individual patients. To break the deadlock, recent international consensus reports, including the 23rd and 28th Acute Disease Quality Initiative workgroup statements, advocate transforming static functional diagnoses into a dynamic theragnosis framework built on predictive enrichment. The diagnostic core is a multimodal biomarker matrix. Structural injury markers such as neutrophil gelatinase-associated lipocalin (NGAL) and kidney injury molecule-1 (KIM-1) enable detection of subclinical stage 1S injury before creatinine rises, allowing clear stratification of functional versus damage-associated injury. Cell-cycle arrest markers, specifically the product of urinary tissue inhibitor of metalloproteinase-2 and insulin-like growth factor-binding protein 7 (TIMP-2 × IGFBP-7), and tubular stress indicators like urinary Dickkopf-3 provide early warning of children progressing toward irreversible tubular damage. Simultaneously profiling systemic biomarkers, including interleukin-6, chemokines, soluble thrombomodulin, angiopoietin-2, and olfactomedin-4, allows clinicians to map whether a patient carries a hyperinflammatory/endothelial-disruption endotype or a hypoinflammatory/energy-suppressed one.

Treatment, in turn, must be tailored to phenotype, because directed interventions show profound heterogeneity of effect across pediatric sub-phenotypes. The editorial, grounded in the landmark AKI1 (low-inflammatory/mild injury) and AKI2 (high-inflammatory/severe endothelial injury) sub-phenotype framework updated with pediatric evidence, maps dichotomous, phenotype-driven intervention strategies. Looking ahead, the authors call for a tripartite synergy: artificial intelligence-driven clinical decision support systems that integrate bedside point-of-care biomarker testing with electronic health record algorithms, such as an automated renal angina index paired with a secondary urinary NGAL tiering pathway; refined clinical trial endpoints that abandon renal replacement therapy initiation as an indiscriminate endpoint in favor of biologically aligned benchmarks such as RRT-free survival days, AKI duration, and fluid-balance-related organ damage; and adaptive platform and umbrella trial designs that introduce transcriptomic endotypes and segment-specific urinary biomarkers into multicenter research. By abandoning the one-size-fits-all approach, the editorial concludes, clinicians can build a precise diagnostic framework bridging systemic host responses and local renal microenvironments, ultimately rewriting the long-term renal outcomes and survival trajectories of every critically ill child with sepsis.

Subject of Research: Precision medicine approaches for pediatric sepsis-associated acute kidney injury based on systemic and organ-level heterogeneity

Article Title: Precision medicine in pediatric sepsis-associated acute kidney injury: when systemic heterogeneity meets organ-level heterogeneity

Article References: Wu, M.-Y., Zhao, Y., Chen, X.-H., & Ge, X.-H. (2026). Precision medicine in pediatric sepsis-associated acute kidney injury: when systemic heterogeneity meets organ-level heterogeneity. World Journal of Pediatrics. https://doi.org/10.1007/s12519-026-01096-5

Image Credits: AI Generated

DOI: 10.1007/s12519-026-01096-5

Keywords: pediatric sepsis, acute kidney injury, precision medicine, biomarkers, sub-phenotypes, serum creatinine, KDIGO guidelines, single-cell RNA sequencing, endothelial glycocalyx, machine learning, renal angina index, intensive care

Writing in Biomedical Microdevices, a team of researchers from Anhui University of Chinese Medicine, the University of Science and Technology of China, and collaborating institutions in Hefei, China, reports that hemodynamic disruption, the weakening of the mechanical forces normally exerted by flowing blood, is associated with degradation of the endothelial glycocalyx, a hairlike carbohydrate coating on the surface of glomerular blood vessels. This gel-like layer, composed of membrane-bound proteoglycans studded with glycosaminoglycans such as heparan sulfate, serves two roles simultaneously: it acts as a selective permeability barrier that repels negatively charged plasma proteins, and it functions as a mechanosensor that translates fluid shear stress into biochemical signals that keep endothelial cells healthy. The team’s central finding, supported by both an animal model and two microfluidic organ-on-a-chip platforms, is that when the mechanical stimulation of flow diminishes, the glycocalyx erodes, the endothelial cytoskeleton falls into disarray, inflammatory adhesion molecules rise to the cell surface, and the glomerular barrier becomes progressively leakier.

The clinical backdrop makes this line of inquiry compelling. Nephrotic syndrome is not simply a disease of leaky filters. It is characterized by heavy proteinuria alongside a hypercoagulable state and abnormal blood rheology, meaning the blood itself behaves differently, with increased viscosity and heightened clotting tendency. That combination creates a potential vicious cycle: if sluggish, abnormally viscous flow means less shear stress delivered to the vessel wall, and if reduced shear stress degrades the glycocalyx that keeps the barrier intact, then the rheological consequences of nephrotic syndrome could actively feed the barrier injury that defines it. Prior clinical work, including a 2025 multicenter cross-sectional analysis in Kidney360, has documented alterations in coagulation and endothelial function in nephrotic patients, but the mechanobiological chain connecting altered microhemodynamics to glycocalyx breakdown had remained largely speculative.

To test the idea, the researchers first turned to a well-established animal model: rats in which nephrotic syndrome is induced by adriamycin, a chemotherapeutic agent also known as doxorubicin whose cardiotoxic and nephrotoxic side effects have long been exploited by researchers to create reproducible proteinuric kidney disease. The treated animals developed the expected signature of the syndrome, with hypercoagulability and increased blood viscosity measurable alongside heavy urinary protein excretion. Critically, high-resolution imaging of the glomerular microvasculature, aided by lanthanum tracer transmission electron microscopy techniques that make the glycocalyx layer visible, revealed marked loss of the endothelial glycocalyx structure and its key components in the adriamycin-treated animals. The scaffolding of the vessel lining, in other words, had crumbled along with the barrier function of the kidney.

The most revealing part of the in vivo work came from a deliberate pharmacological comparison. The team treated separate groups of nephrotic rats with two mechanistically distinct drugs. Sulodexide, a glycosaminoglycan compound that has been used clinically to address microalbuminuria and that prior studies have shown to remodel and restore the glycocalyx in sepsis models, acted on the structural side of the problem. Prednisone acetate, the classic glucocorticoid of nephrology practice, works mainly through immunosuppression and has been shown to act directly on podocytes, stabilizing their cytoskeleton through glucocorticoid receptor signaling. The results split cleanly. Sulodexide ameliorated the hemorheological abnormalities and restored glycocalyx integrity, while prednisone predominantly reduced proteinuria and inflammatory adhesion molecule expression. The dissociation suggests that glycocalyx loss and inflammatory activation are partially separable axes of the disease, and that repairing the endothelial sugar coat is a distinct therapeutic target from calming inflammation.

Animal models, however, cannot cleanly separate cause from effect. Adriamycin is a direct toxin, and the glycocalyx damage it causes might simply reflect poisoning of endothelial cells rather than altered blood flow. To isolate the mechanical variable, the team built two microfluidic devices: a vascular-on-a-chip and a glomerulus-on-a-chip. These platforms, which culture living endothelial cells within engineered microchannels perfused by programmable pumps, allow researchers to dictate exactly what shear stress the cells experience. The team exposed endothelial cells to a series of stepwise reductions in perfusion flow rate, systematically stripping away the mechanical stimulation that vessels normally deliver, while keeping the chemical environment constant. What they observed was a progressive and dose-like response. As flow diminished, the glycocalyx thinned and degraded, the actin cytoskeleton lost its organized architecture, endothelial cells flipped into an activated, pro-inflammatory state marked by adhesion molecules, and in the glomerulus-on-a-chip, the permeability of the reconstructed filtration barrier measurably increased.

This chip-based evidence elevates the study from correlation toward mechanism. The finding dovetails with a growing body of mechanobiology showing that the endothelial glycocalyx is not a passive scaffold but a dynamic antenna, protruding into the flow stream and deforming under shear stress. Reviews of the field, including work on basal glycocalyx responses to shear stress published in Frontiers in Cell and Developmental Biology, describe how the layer participates in flow sensing through the glypican and syndecan proteoglycan families, transmitting mechanical information to the cytoskeleton and to junctional complexes. Earlier microfluidic work has shown that reducing shear stress disorganizes the actin cytoskeleton, and that laminar flow shapes the morphology and functional phenotype of glomerular endothelial cells in particular. The new study stitches these threads together in a disease context, proposing an endothelial-glycocalyx-centered mechanobiological pathway through which the hypercoagulable, viscous blood of nephrotic syndrome could erode the very barrier whose failure defines the disease.

The authors are careful, and appropriately so, about the limits of the claim. Their own data did not confirm that adriamycin-induced injury was entirely mediated by hemodynamic alterations. Direct toxic effects on podocytes and tubules, along with inflammatory cascades, clearly operate in parallel, and the study positions reduced flow-associated mechanical stimulation as a plausible contributor rather than the sole cause. That framing is scientifically honest and, arguably, more useful clinically, because it reframes nephrotic syndrome as a disease of converging insults, a direct chemical injury layered with an inflammatory assault and compounded by the biomechanical consequences of altered blood rheology. Any one of those axes might be attacked therapeutically, and the study’s drug comparison hints at how: glucocorticoids address inflammation and podocyte stabilization, while glycosaminoglycan-based agents such as sulodexide address the structural and rheological dimension.

The broader significance lies in what organ-on-a-chip technology makes possible. By decoupling flow from chemistry, toxicity, and systemic factors, the vascular-on-a-chip and glomerulus-on-a-chip platforms used in this work offer a template for interrogating hemodynamic contributions to other barrier diseases, from sepsis-related vascular leak to diabetic nephropathy, where glycocalyx degradation is also implicated. The authors have placed all raw data, protocols, and analytical procedures in a public repository to support reproducibility. For patients with nephrotic syndrome, many of whom face relapsing disease and the side effects of long-term steroids, the study opens a tantalizing prospect: that protecting or rebuilding a microscopic sugar coating, and in doing so restoring the mechanical conversation between blood and vessel wall, could one day help seal the kidney’s failing filter from the blood side.

Subject of Research: Mechanobiological degradation of the endothelial glycocalyx driving glomerular filtration barrier injury in nephrotic syndrome

Article Title: Hemodynamic disruption triggers glomerular barrier injury via endothelial glycocalyx degradation in nephrotic syndrome

Article References: Feng, Y., Wang, S., Wang, Y., Yang, M., Miao, C., Wang, Q., Ding, W., Tan, H., Luo, T., & Xu, F. (2026). Hemodynamic disruption triggers glomerular barrier injury via endothelial glycocalyx degradation in nephrotic syndrome. Biomedical Microdevices, 28(4), Article 67. https://doi.org/10.1007/s10544-026-00850-w

Image Credits: AI Generated

DOI: 10.1007/s10544-026-00850-w

Keywords: nephrotic syndrome, endothelial glycocalyx, glomerular filtration barrier, fluid shear stress, organ-on-a-chip, glomerulus-on-a-chip, hemodynamics, proteinuria, sulodexide, adriamycin nephropathy, mechanobiology, microfluidics