Alzheimer’s disease remains the most common form of dementia worldwide, and while much research has focused on amyloid plaques and tau tangles, a growing body of evidence points to neuroinflammation as a central engine of disease progression. At the heart of this process are microglia, the brain’s native immune sentinels. In healthy tissue, microglia patrol the brain, clear debris, and support neuronal function. In Alzheimer’s disease, however, they become reactive, releasing a storm of pro-inflammatory signaling molecules such as tumor necrosis factor-alpha, interleukin-6, and interleukin-1 beta that can injure the very neurons they are meant to protect. Understanding what tips microglia into this destructive mode has become one of the most urgent questions in neurodegeneration research.

Phospholipid scramblase 1 has previously been implicated in promoting inflammatory responses in other contexts, which prompted the authors, Lixiang Gao of the Department of Neurology at Yantai Affiliated Hospital of Shandong Medical and Pharmaceutical University and Yuejun Lin of the Department of Neurology at Yantaishan Hospital Affiliated to Shandong Medical and Pharmaceutical University, to investigate whether the protein contributes to the pathogenesis of Alzheimer’s disease. Their strategy combined animal and cell-based approaches. In vivo, they used APP/PS1 transgenic mice, a widely used model that develops amyloid pathology and memory deficits, and achieved PLSCR1 knockdown to assess its effects on NLR family pyrin domain containing 3, or NLRP3, inflammasome activation in microglia. In vitro, they turned to BV2 microglial cells stimulated with lipopolysaccharide, a bacterial molecule that reliably provokes inflammatory activation, to dissect the effects of PLSCR1 on cell viability and inflammatory signaling.

The first key observation was that PLSCR1 expression was markedly upregulated in the hippocampus of APP/PS1 mice, the brain region most critical for forming new memories and one of the earliest areas affected in Alzheimer’s disease. The same elevation appeared in LPS-induced BV2 microglial cells, suggesting that PLSCR1 induction is a consistent feature of the inflammatory state that characterizes the disease in both living brain tissue and isolated immune cells. This pattern positioned PLSCR1 not as a passive bystander but as a candidate driver of the neuroinflammatory process, prompting the team to ask what happens when the protein is removed from the equation.

The answer was striking. PLSCR1 knockdown improved cognitive dysfunction in the APP/PS1 mice, indicating that dampening this single protein translated into measurable functional benefits for the animals. Behind that behavioral improvement lay a broad remodeling of the inflammatory environment. When PLSCR1 was silenced, expression of the pro-inflammatory mediators TNF-alpha, iNOS, IL-6, and IL-1 beta went down, while expression of anti-inflammatory and repair-associated markers, including ARG-1, CD206, IL-10, IL-13, and IL-4, went up. In effect, the balance of microglial activity shifted away from a damage-promoting phenotype and toward a restorative one, the kind of polarization that supports tissue healing rather than chronic injury.

The cell culture experiments reinforced this picture and clarified the mechanism. Exposure to lipopolysaccharide promoted microglial activity in the BV2 cells, but PLSCR1 knockdown attenuated that activation and counteracted the LPS-induced shift of microglia toward a pro-inflammatory phenotype. In other words, even when the cells were bombarded with a potent inflammatory trigger, removing PLSCR1 kept them from fully committing to the aggressive state. This suggests that PLSCR1 acts upstream of or in parallel with external inflammatory signals, functioning as a kind of permission factor that allows microglia to escalate their response. Blocking that permission, the data imply, can restrain the escalation itself.

Central to the study’s conclusions is the NLRP3 inflammasome, a multiprotein complex assembled within immune cells that acts as a molecular alarm and munitions factory. When activated, NLRP3 initiates a cascade that processes interleukin-1 beta and related cytokines into their mature, highly inflammatory forms, and its chronic activation has been repeatedly linked to neurodegeneration. The researchers found that PLSCR1 knockdown suppressed NLRP3 inflammasome activation in microglia both in vivo and in vitro, providing a mechanistic thread that connects the protein to the production of interleukin-1 beta and, ultimately, to the cognitive decline observed in the mice. By closing this pathway, PLSCR1 silencing appeared to cut the inflammatory cascade off at a critical junction.

The implications for Alzheimer’s therapy are intriguing, though the authors frame the work as identifying a target rather than delivering a treatment. Current approaches to the disease, including amyloid-targeting antibodies, address upstream pathology but do not directly resolve the neuroinflammatory component that many researchers believe drives ongoing neuronal loss. A strategy that restrains microglial activation through PLSCR1 or the NLRP3 inflammasome could, in principle, complement plaque-directed therapies by protecting the brain’s vulnerable circuits from collateral inflammatory damage. The findings also raise the possibility that PLSCR1 levels could serve as a biomarker of inflammatory activity in the Alzheimer’s brain, helping clinicians track disease state or treatment response.

As with any preclinical study, important steps remain before these results can inform human medicine. The experiments were conducted in a transgenic mouse model and in a microglial cell line, and the complexity of human Alzheimer’s disease, in which inflammation interacts with vascular, metabolic, and genetic factors over decades, may present additional layers of regulation not captured here. Nevertheless, the study delivers a clear and internally consistent message: PLSCR1 functions as a key driver of neuroinflammation and cognitive decline in Alzheimer’s disease, operating through activation of the NLRP3 inflammasome in microglia. By demonstrating that reducing PLSCR1 improves cognition while simultaneously lowering inflammatory cytokines, promoting repair-associated microglial markers, and suppressing inflammasome signaling, Gao and Lin have added a compelling new node to the growing map of Alzheimer’s neuroimmunology, and one that researchers studying inflammasome-targeted therapies will be watching closely.

Subject of Research: The role of PLSCR1 in microglial NLRP3 inflammasome activation and neuroinflammation in Alzheimer's disease

Article Title: PLSCR1 knockdown reduces inflammatory microglial activation in Alzheimer’s disease by inhibiting NLRP3 inflammasome

Article References: Gao, L., & Lin, Y. (2026). PLSCR1 knockdown reduces inflammatory microglial activation in Alzheimer’s disease by inhibiting NLRP3 inflammasome. BMC Neuroscience. https://doi.org/10.1186/s12868-026-01045-y

Image Credits: AI Generated

DOI: 10.1186/s12868-026-01045-y

Keywords: Alzheimer's disease, PLSCR1, microglia, NLRP3 inflammasome, neuroinflammation, cognitive decline, APP/PS1 mice, BV2 cells, interleukin-1 beta, neurodegeneration, knockdown, reduces

The research builds on the group’s earlier work showing that myeloid-derived suppressor cells, or MDSCs, accumulate in abundance within human esophageal squamous cell carcinoma, the dominant histological subtype of esophageal cancer worldwide, and that their presence correlates with worse patient outcomes. What remained unclear was whether MDSCs contribute to tumor propagation through mechanisms that go beyond their canonical role of suppressing T cells. To answer that question, the investigators turned to mouse models of esophageal cancer that included both immunocompetent animals and mice lacking T cells altogether. If MDSCs promoted tumor growth only by disarming T cells, their influence should have vanished in the T cell-deficient setting. Instead, the tumors accelerated in both contexts, a result that signaled the existence of an intrinsic, T cell-independent tumor-promoting program driven by these myeloid cells.

Tracking down the molecular machinery behind that program led the team to an unexpected transcription factor. When the researchers depleted MDSCs in tumor-bearing mice using an anti-Gr1 antibody, or when they neutralized the inflammatory cytokine interleukin-1 beta, expression of HNF1A inside the tumor cells dropped. HNF1A, a transcription factor best known for its roles in liver and pancreatic development and metabolism, has more recently been implicated in tumor biology, but its involvement in MDSC-driven esophageal cancer progression had not been established. The new data place it at the center of the circuit: MDSCs, acting through IL-1 beta, appear to switch on HNF1A within the carcinoma cells themselves.

From HNF1A, the signal flows onward to a chemokine. The study showed that HNF1A sustains the activity of the CXCL1 promoter, and that disrupting the upstream inputs, whether by depleting MDSCs or blocking IL-1 beta, blunted CXCL1 promoter activity and reduced CXCL1 output. CXCL1 is a chemokine of the CXC family that signals through the receptor CXCR2 and is well recognized as a mediator of neutrophil recruitment and inflammatory signaling in tumors. In this context, however, its downstream consequences are not primarily inflammatory in the classical sense. Rather, the researchers found that the HNF1A-CXCL1 axis feeds directly into the core stemness machinery of the cancer cells, downregulating or, when the axis is active, sustaining the expression of the transcription factors Oct4, Nanog and Sox9, the canonical guardians of stem-like identity in embryonic and cancer stem cells alike.

The functional consequences of that molecular cascade were tested with rigor. When the team deleted HNF1A specifically in tumor cells, the MDSC-driven expansion of the cancer stem cell population collapsed, and, critically, the ability of the tumors to initiate new growth was abolished. Tumor initiation is the hallmark functional readout of cancer stem cell activity: only cells with genuine self-renewal capacity can seed a new tumor from a limited inoculum. The fact that HNF1A deletion eliminated this capacity demonstrates that the transcription factor is not merely a correlate of stemness but a required licensing factor in this pathway. Conversely, when the researchers supplied exogenous IL-1 beta, the cancer stem cell frequencies rebounded, confirming that the myeloid-cell-derived cytokine sits upstream of the entire axis and is sufficient to re-ignite the stem-like program.

These results reframe the relationship between inflammation and cancer stemness in esophageal cancer. Rather than acting as passive bystanders that merely modulate the immune microenvironment, MDSCs emerge as active instructors of tumor cell identity, delivering an IL-1 beta signal that is transcribed into a heritable, self-reinforcing stem-like state through HNF1A and CXCL1. Because the pathway was operative in T cell-deficient mice, the authors conclude that MDSC-derived IL-1 beta licenses the HNF1A-CXCL1 axis and sustains cancer stem cell properties independently of adaptive immunity. That independence matters clinically. Modern oncology has invested heavily in T cell-directed strategies, from immune checkpoint inhibitors to engineered cell therapies, and esophageal cancer has been among the tumor types to benefit. But a tumor-promoting program that runs beneath the T cell layer provides a reservoir of malignant potential that such therapies would not touch, and it may help explain why responses in esophageal squamous cell carcinoma remain incomplete for many patients.

The therapeutic implication drawn by the authors is that targeting this pathway could complement, rather than replace, T cell-focused treatments. Several points of intervention suggest themselves from the data. MDSC depletion, as achieved with anti-Gr1 in the preclinical setting, removes the source of the signal. IL-1 beta neutralization interrupts the messenger, and IL-1-blocking agents already exist in the clinical arsenal for inflammatory diseases, offering a plausible route to translation. Downstream, the CXCL1-CXCR2 axis is a recognized drug target, with CXCR2 antagonists under investigation in multiple cancers. Each of these strategies was supported, directly or indirectly, by the experimental results: depleting MDSCs or neutralizing IL-1 beta reduced HNF1A expression, dampened CXCL1 promoter activity and lowered stemness factor levels, while restoring IL-1 beta reinstated cancer stem cell frequencies.

The study also carries prognostic weight. The graphical summary accompanying the article emphasizes that the HNF1A-driven CXCL1 program not only licenses stem-like properties in esophageal squamous cell carcinoma but also predicts poor prognosis, consistent with the team’s earlier finding that MDSC abundance in human tumors correlates with adverse outcomes. Cancer stem cells are widely associated with resistance to chemotherapy and radiotherapy, metastatic dissemination and relapse after apparently curative treatment, so a microenvironmental signal that expands this compartment provides a mechanistic bridge between inflammatory infiltration and clinical aggressiveness. For patients with esophageal squamous cell carcinoma, a disease with persistently poor survival statistics in many regions, that bridge may represent one of the more actionable links identified to date.

Methodologically, the work combined genetically defined mouse models, cell-specific deletion of HNF1A, pharmacologic MDSC depletion, cytokine neutralization and supplementation, and molecular readouts of promoter activity and stemness factor expression, an integrated design that allowed the authors to move from correlation to causal mechanism. The study was supported by the National Natural Science Foundation of China, and the MEC25 cell line used in the experiments was provided by the laboratory of Professor Li Fu at Shenzhen University Medical School. The corresponding author, Yi Zhang, holds appointments across the Biotherapy Center and Cancer Center of the First Affiliated Hospital of Zhengzhou University, the State Key Laboratory of Metabolic Dysregulation and Prevention and Treatment of Esophageal Cancer, and related Zhengzhou University institutions, reflecting the translational infrastructure behind the project. The article was received in January 2026, accepted in September 2026 and published on 20 September 2026 under a Creative Commons Attribution license.

As with any preclinical study, the path from mouse models to patient benefit will require validation in human tumor specimens and, ultimately, clinical testing of pathway-targeted interventions. Nevertheless, the conceptual advance is clear and consequential: the immune microenvironment does not merely decide whether the immune system sees a tumor, it can also decide what the tumor is. In esophageal squamous cell carcinoma, myeloid-derived suppressor cells appear to whisper a developmental command into the cancer cells, activating HNF1A, broadcasting CXCL1 and preserving a self-renewing core that survives whatever the immune system or the oncologist throws at it. Silencing that command, whether by removing the myeloid messengers, intercepting their IL-1 beta message or blocking the CXCL1 relay downstream, now stands as a defined and testable strategy to strip esophageal cancer of its stem-like resilience and to make T cell-directed therapies work against a smaller, more vulnerable target.

Subject of Research: How myeloid-derived suppressor cells confer cancer stem cell properties to esophageal squamous cell carcinoma via the HNF1A/CXCL1 signaling axis

Article Title: Myeloid-derived suppressor cells confer stemness to esophageal cancer cells through the HNF1A/CXCL1 signaling axis

Article References: Qin, G., Ma, P., Liu, S., Chen, T., Guo, K., Zhao, Q., Wu, P., Chen, X., & Zhang, Y. (2026). Myeloid-derived suppressor cells confer stemness to esophageal cancer cells through the HNF1A/CXCL1 signaling axis. Cancer Immunology, Immunotherapy. https://doi.org/10.1007/s00262-026-04577-8

Image Credits: AI Generated

DOI: 10.1007/s00262-026-04577-8

Keywords: myeloid-derived suppressor cells, esophageal squamous cell carcinoma, HNF1A, CXCL1, cancer stem cells, interleukin-1 beta, tumor microenvironment, stemness, Oct4, Nanog, Sox9, cancer immunology

The team’s starting point was the observation that osteoarthritis is driven largely by the progressive loss of the extracellular matrix, the network of collagens and proteoglycans that gives cartilage its resilience. When chondrocytes, the resident cells of cartilage, are exposed to inflammatory signals such as interleukin-1 beta, they ramp up enzymes that chew through this matrix, including members of the ADAMTS family. Current clinical options have shown limited efficacy in halting this degradation, which makes the search for the regulatory switches controlling matrix integrity a central goal of osteoarthritis research.

To model the disease in the laboratory, the researchers treated rat chondrocytes with 10 nanograms per milliliter of interleukin-1 beta for 24 hours. This well-established protocol reliably triggers an inflammatory, matrix-degrading phenotype. The team then measured the secretion of the inflammatory cytokines TNF-alpha and IL-6 by enzyme-linked immunosorbent assay, assessed the abundance of matrix components using alcian blue staining, and tracked the expression of candidate molecules with reverse transcription quantitative PCR, western blotting, and immunofluorescence staining. These complementary readouts allowed them to connect molecular changes at the level of genes and proteins to the physical integrity of the matrix the cells maintain.

The first key finding concerned AURKA, a kinase best known for controlling cell division but increasingly implicated in cartilage biology. When chondrocytes were stimulated with interleukin-1 beta, AURKA levels rose while the expression of both DOT1L and ITCH fell. This inverse relationship suggested a regulatory circuit in which ITCH normally restrains AURKA. Follow-up experiments using co-immunoprecipitation confirmed a physical interaction between ITCH and AURKA and demonstrated that ITCH promotes the ubiquitination of AURKA, tagging the kinase for destruction by the cell’s protein degradation machinery. When ITCH was abundant, AURKA was degraded; when ITCH dwindled under inflammatory conditions, AURKA accumulated.

The consequences for the cartilage matrix were striking. The experiments showed that ITCH, by promoting AURKA ubiquitination and degradation, attenuated the interleukin-1 beta-stimulated degradation of the extracellular matrix in rat chondrocytes. In other words, ITCH acts as a protective brake: its activity keeps AURKA levels in check, and low AURKA corresponds to a better-preserved matrix. This finding builds on earlier work by the same group, which had reported that the E3 ligase HECTD1 similarly targets AURKA for ubiquitination, and that inflammation disrupts that process to drive matrix degradation through enhanced translation of ADAMTS12. The new study adds a second E3 ligase, and an upstream epigenetic controller, to this emerging network.

That upstream controller is DOT1L, a histone methyltransferase that deposits the H3K79me3 mark on histone H3 at lysine 79. Unlike many histone modifications, H3K79 methylation occurs within the body of transcribed genes and is associated with active gene expression. Using chromatin immunoprecipitation, or ChIP, the researchers detected enrichment of both DOT1L and the H3K79me3 mark at the promoter region of the ITCH gene, indicating that DOT1L directly boosts ITCH transcription through this epigenetic modification. When DOT1L activity is reduced, as it is under inflammatory stimulation, H3K79me3 at the ITCH promoter drops, ITCH expression falls, AURKA escapes degradation, and matrix-degrading programs gain the upper hand.

To test whether reinforcing this axis could protect cartilage in a living organism, the team established a rat model of osteoarthritis induced by anterior cruciate ligament transection, a surgical model that mimics post-traumatic osteoarthritis in humans. Into the injured joints they injected a lentivirus engineered to drive overexpression of DOT1L. The joints were subsequently analyzed by hematoxylin and eosin staining, safranin O-fast green staining, and immunohistochemistry, standard histological approaches for assessing cartilage structure and proteoglycan content. All animal procedures were reviewed and approved by the Animal Ethics Committee of Hunan Provincial People’s Hospital.

The in vivo results supported the mechanistic model. Overexpression of DOT1L alleviated the cartilage degeneration caused by ligament transection, and molecular analysis revealed the expected downstream signature: the surgery-induced downregulation of ITCH was reversed, while the surgery-induced upregulation of AURKA and the matrix-degrading enzyme ADAMTS5 was blunted. In effect, elevating DOT1L re-engaged the epigenetic-to-proteolytic pathway that injury had silenced, preserving the cartilage that would otherwise have been lost. These findings identify the DOT1L/ITCH/AURKA axis as a key epigenetic and post-translational regulatory mechanism that protects against extracellular matrix degradation in osteoarthritis.

The study also fits into a broader and growing body of evidence that DOT1L is a guardian of cartilage health. Previous work has shown that mice deficient in Dot1l in cartilage are more susceptible to both spontaneous and post-traumatic osteoarthritis, and that hypoxia induces DOT1L in articular cartilage as a protective response. Research on inhibitors of the H3K79 demethylases KDM7A/B has likewise suggested that restoring H3K79 methylation can protect against osteoarthritis. Meanwhile, ITCH has previously been shown to limit post-traumatic osteoarthritis progression in mice by inhibiting macrophage polarization, and to improve lipopolysaccharide-induced chondrocyte injury by mediating ubiquitination of JAG1. The new study ties these threads together into a single coherent pathway, from chromatin marks through E3 ligase activity to kinase stability and matrix integrity.

The translational implications are considerable. If the DOT1L/ITCH/AURKA axis behaves similarly in human cartilage, strategies that boost DOT1L activity or H3K79me3 deposition, stabilize ITCH, or blunt AURKA accumulation in chondrocytes could slow or halt the matrix destruction that defines the disease. Because DOT1L inhibitors already exist and are being tested in oncology, the enzymology of this target is comparatively well understood, although any therapeutic repurposing would require careful evaluation of DOT1L’s roles in other tissues, where it participates in processes ranging from cardiac stress responses to cell proliferation and differentiation. The authors note that their findings collectively illuminate how epigenetic regulation and protein ubiquitination intersect to govern joint health, and the work was supported by the Research Project of Hunan Provincial Health Commission. For millions of people living with osteoarthritis, the study offers something that has been in short supply: a precisely mapped molecular circuit whose restoration in an animal model measurably preserved cartilage, and which now stands as a concrete starting point for designing drugs that attack the disease at its mechanistic roots rather than merely masking its symptoms.

Subject of Research: Epigenetic and post-translational regulation of cartilage extracellular matrix degradation in osteoarthritis via the DOT1L/ITCH/AURKA axis

Article Title: DOT1L-mediated H3K79me3 of ITCH promotes AURKA ubiquitination to suppress ECM degradation in osteoarthritis

Article References: DOT1L-mediated H3K79me3 of ITCH promotes AURKA ubiquitination to suppress ECM degradation in osteoarthritis. (n.d.). https://doi.org/10.1007/s00438-026-02514-z

Image Credits: AI Generated

DOI: 10.1007/s00438-026-02514-z

Keywords: osteoarthritis, DOT1L, H3K79me3, ITCH, AURKA, ubiquitination, extracellular matrix, chondrocytes, epigenetics, cartilage degradation, ADAMTS5, interleukin-1 beta