Metabolic dysfunction-associated steatotic liver disease (MASLD) comprises a spectrum of liver diseases from simple steatosis to metabolic dysfunction-associated steatohepatitis and its associated fibrosis, cirrhosis, and MASLD-associated hepatocellular carcinoma (MASLD-HCC). MASLD affects over one-third of the global adult population and is closely associated with insulin resistance, obesity, genetic factors, and increasingly recognized, gut microbiome dysbiosis. The gut-liver axis, referring to the communication network between the intestinal microbiota and liver, is critical to the progression of MASLD. The gut microbiota composition and/or functions are disrupted, leading to intestinal barrier destruction, systemic inflammation and modulation of hepatic metabolism and immune responses. The review aims to summarize the effects of gut microbiota on MASLD and its malignant transition to associated HCC based on their roles of microbial metabolites, immune regulation and their associated genetic factors, and to discuss the potential application of microbiome-targeted therapeutic strategies, including probiotics and prebiotics, synbiotics and postbiotics, fecal microbiota transplantation, engineered bacteria and bacteriophage therapy, small molecule inhibitors, microbiota-derived metabolites, with the aim of providing a new vision in the treatment of MASLD and MASLD-HCC. Finally, we discuss current challenges in basic and clinical research of the role of microbiome in MASLD and propose future directions to drive progress in this field.

Cholestatic liver diseases are characterized by impaired bile flow. Repairing damage and reestablishing biliary function may slow disease progression and reduce complications. The Wnt/β-catenin pathway can facilitate biliary repair during cholestasis through multiple mechanisms. The impact of constitutive Wnt/β-catenin signaling during cholestasis was analyzed using S45D transgenic (TG) mice, which express non-degradable β-catenin. Compared to WT, TG mice had increased inflammation and decreased fibrosis during prolonged cholestasis. Furthermore, TG mice had increased ductular reaction and hepatocyte reprogramming, which may alleviate injury. Since both Wnt/β-catenin and Yap pathways are implicated in cell plasticity, whether β-catenin works in concordance with or independent of Yap was investigated. In vitro studies demonstrated that Yap was not required for Wnt-mediated hepatocyte reprogramming. Spatial transcriptomics demonstrated suppression of Wnt/β-catenin activity in pericentral hepatocytes, while periportal Yap activation increased in early cholestasis. A dual reporter mouse model showed enhanced Wnt activation in both pericentral and periportal TG HC compared to WT, while Yap activation was equivalent in WT and TG. Transcriptomic analysis of human livers demonstrated that Wnt/β-catenin and Yap target genes also map to distinct cell compartments in cholestatic patients. These findings suggest that enhanced Wnt/β-catenin activation in TG mice accelerates compensatory responses and attenuates disease progression. Activation of Wnt/β-catenin and Yap in different cell types indicates that β-catenin functions independently of Yap.

Delayed corneal wound healing and sensory neuropathy are hallmarks of diabetic keratopathy, yet the role of corneal epithelial cell (CEC)-derived exosomes in these processes remains unclear. This study characterized exosomes secreted by the mouse corneal epithelial progenitor cell line TKE2 at either quiescent state or scratch-wounded. The isolated extrasellar vesicles wer characterized by nanoparticle tracking analysis, transmission electron microscopy, and Western blotting. Exosomal cargo was analyzed by LC-MS/MS proteomics. The roles of exosome and selected proteins were assessed for effects on wounded healing of normoglycemic and streptozotocin-induced diabetic C57BL/6J mice. The isolated vesicles exhibited canonical exosomal features and were readily taken up by CEC at 1 dpw and trigeminal sensory neurons at 3 dpw. Exosomes derived from healing, but not quiescent, cultures accelerated delayed epithelial wound closure in diabetic corneas, while having little effect on normoglycemic corneas. HTRA1, enriched in healing exosomes, contributed to epithelial wound healing in normal corneas, as its inhibition attenuated wound closure in normoglycemic but not diabetic mice. In contrast, treating healing exosomes with a STAT3 inhibitor, which permanently blocks its activity without altering protein content, partially reduced exosome-mediated wound healing in diabetic corneas. Collectively, these findings support context-dependent effects of CEC-derived exosomes in corneal wound repair and suggest that exosomal components may contribute to the regulation of diabetic corneal wound healing.

Epithelial-mesenchymal transition (EMT) of medial edge epithelial cells is a critical mechanism underlying embryonic palatal fusion, driven by transforming growth factor beta 3 (TGF-β3). However, its regulatory interplay with pluripotency factors (SOX2/OCT4) and reliance on downstream cascades remain poorly understood. This study investigates these networks to elucidate the mechanisms of cellular reprogramming during palatogenesis. Embryonic day 15 C57BL6/J mouse palatal epithelial cells were isolated to eliminate mesenchymal interference. Cells were subjected to recombinant TGF-β3 (1, 3, 10 ng/mL) or targeted siRNA knockdowns of Tgfb3, Sox2, Oct4, and Smad2/3, and evaluated via RNA sequencing, qRT-PCR, immunofluorescence, TEER, and flow cytometry. Treatment with 1-3 ng/mL TGF-β3 successfully induced EMT in vitro, characterized by decreased E-cadherin, increased fibronectin, diminished membrane resistance, and a fibroblast-like morphological shift. This transition was predominantly associated with non-canonical pathways; phosphorylated Smad2/3 levels remained unchanged while Smad-independent mediators (p38 MAPK and Mmp13) were upregulated (p<0.05). Furthermore, TGF-β3 downregulated the pluripotency markers Sox2 and Oct4 (p<0.05). Combined Sox2/Oct4 knockdown with TGF-β3 yielded the most pronounced EMT characteristic. While Tgfb3 knockdown heavily attenuated EMT, partial mesenchymal transition persisted, indicating redundant compensatory networks. In conclusion, optimal TGF-β3 concentrations (1-3 ng/mL) shift EMT toward Smad-independent pathways during palatogenesis. This reprogramming requires TGF-β3 to suppress SOX2 and OCT4, underscoring their roles as negative regulators of EMT during palatal fusion.

Peripheral nerve injury (PNI) often leads to severe functional deficits, yet the molecular mechanisms underlying nerve regeneration remain incompletely understood. Here, the function of transforming growth factor-β-activated kinase 1 (TAK1) in peripheral nerve regeneration was examined using murine and rat models of sciatic nerve injury. The results show that TAK1 overexpression impairs nerve regeneration and functional recovery, whereas pharmacological inhibition of TAK1 with Takinib promotes these processes. Mechanistically, the detrimental effects of TAK1 are associated with sustained inflammatory responses within the sciatic nerve. TAK1 is predominantly expressed in Schwann cells and fibroblasts in the sciatic nerve, where it activates NF-κB signaling. Specifically, TAK1 phosphorylates protein phosphatase 1 regulatory subunit 18 (PPP1R18) at serine 213, thereby relieving its suppression on the NF-κB pathway and facilitating the nuclear accumulation of NF-κB p65. This activation drives chemokine expression, leading to enhanced recruitment of M1 macrophages and the establishment of a proinflammatory microenvironment that impedes remyelination and nerve regeneration. Collectively, these findings identify TAK1 as a critical negative regulator of peripheral nerve repair and highlight TAK1 inhibition as a potential therapeutic approach for improving recovery following PNI.

A common side effect of the chemotherapeutic anthracycline, doxorubicin, is cardiotoxicity and progression to heart failure. Patients treated with anthracyclines show increased circulating cytotoxic CD8[+]IFN-γ[+] T cells. In mice, cumulative doses of doxorubicin also result in increased circulating and cardiac infiltrating CD8[+]IFN-γ[+] T cells, and these cells are required for pathological fibrosis and contractile dysfunction. The present study demonstrates that cardiac fibroblasts become immunologically active and express major histocompatibility complex (MHC) class II on the onset of doxorubicin cardiotoxicity in humans and in mice. Using adoptive transfer and in vitro mechanistic studies, the results show that CD8[+]IFN-γ[+] T cells are required for cardiac fibroblast expression of MHC-II in mice treated with doxorubicin, and that doxorubicin induces cardiac fibroblast expression of CXCL9, resulting in CD8[+]IFN-γ[+] T cell cardiotropism. Selective deletion of MHC-II in cardiac fibroblasts ameliorates systolic dysfunction and dampens cardiac fibrosis induced by doxorubicin in mice. Mechanistically, this study shows that cardiac fibroblast MHC-II is required for cardiac CD4[+]IFN-γ[+] T cell infiltration and proliferation, necessary for cardiac CD8[+] T cell immune responses and cytotoxicity. These results position cardiac fibroblast MHC-II as a key mediator of contractile dysfunction in doxorubicin cardiotoxicity.

Recent advanced comprehensive analyses reveal complement factors as critical regulators of cancer-immune system interactions. We previously identified that complement factor B (CFB), a key secreted component of the alternative complement pathway, is aberrantly upregulated in pancreatic ductal adenocarcinoma (PDAC) and contributes to tumor progression. Iptacopan (LNP023), a selective CFB inhibitor, has established efficacy in complement-mediated disorders; however, its anticancer potential remains unexplored. We investigated the effects of iptacopan on PDAC cell biology and the tumor immune microenvironment using in vitro assays and orthotopic mouse models. Iptacopan significantly suppressed human and murine PDAC cell proliferation and enhanced gemcitabine cytotoxicity. Mechanistically, CFB inhibition induced senescence, as evidenced by increased senescence-associated β-Gal activity and p21 upregulation. In in vivo preclinical studies, iptacopan reduced tumor growth, diminished intratumoral CFB and C5b-9 deposition, and increased p21 expression, indicating tumor-localized complement inhibition. Furthermore, iptacopan decreased conventional Foxp3[+] regulatory T-cells (Tregs) and the immunosuppressive CD8[+]/Foxp3[+] Treg subset while enhancing CD8[+] tumor-infiltrating lymphocytes, reshaping the tumor immune microenvironment. Combination therapy with immune checkpoint blockades (anti-PD-1 and anti-CTLA-4) further augmented antitumor effects, and triple therapy with gemcitabine/nab-paclitaxel yielded the greatest tumor suppression. These results demonstrate that iptacopan exerts dual antitumor effects by inducing tumor-intrinsic senescence and promoting an immunostimulatory tumor immune microenvironment. Therefore, CFB inhibition represents a promising complement-based immunomodulatory treatment for PDAC.

This protocol outlines the detailed steps for generating a colorectal cancer liver metastasis (CRCLM) mouse model using three complementary approaches (1) portal venous seeding of CRCLM cells to simulate tumor cell dissemination through the portal circulation to the liver (2) liver parenchymal implantation of CRCLM solid tumors to create single, localized lesions derived from tumors generated via the portal venous seeding, and (3) intrahepatic parenchymal injection of CRCLM cells to produce isolated tumors directly within the liver tissue. The protocol emphasizes precise tissue handling and preservation, ensuring high tumor take rates while minimizing peritoneal disease, a common complication among CRCLM mouse models. These refined methods offer reliable and reproducible CRCLM models, providing a robust tool for studying tumor-host interactions and conducting preclinical evaluations of potential therapies.

Diabetic retinopathy is a potentially blinding complication of diabetes mellitus and the leading cause of irreversible vision loss in the working-age population. Diabetic retinopathy has historically been thought of as a microvascular complication of diabetes, but more recent research has shown that retinal neurons and glia are affected before clinically detectable vascular alterations. Although treatments have been developed to address the vascular lesions of diabetic retinopathy, there are currently no treatments for the early-onset neuro-glial perturbations. Increasing evidence supports inflammation as a critical factor in the development of neuro-glial dysfunction in the diabetic retina. Inflammatory processes are further activated in retinal neurons themselves in response to diabetes. The current review focuses on inflammatory molecular and physiological changes in the diabetic retina. The emerging evidence for a relationship between retinal neurons and glia and the inflammatory cascade is explored.

Peritoneal angiogenesis is a key determinant of long-term peritoneal dialysis outcomes, yet the contribution of IL-17 remains unclear. This study examined the association between IL-17 and peritoneal vascularity in patients undergoing peritoneal dialysis and defined mechanisms linking IL-17 to vascular endothelial growth factor (VEGF) expression in human peritoneal mesothelial cells. Peritoneal biopsies showed sparse IL-17 expression, but IL-17 positivity correlated with increased IL-6 and VEGF expression and higher CD31[+] microvessel density, indicating a coordinated pro-angiogenic network. In vitro, IL-17 induced IL-6 mRNA and protein in human peritoneal mesothelial cells in a time- and dose-dependent manner but did not directly stimulate VEGF. However, combined IL-17 and soluble IL-6 receptor markedly increased VEGF mRNA, promoter activity, and protein secretion, consistent with IL-6 trans-signaling. Genetic or antibody-mediated inhibition of IL-6 abolished VEGF induction, confirming IL-6 dependency. Mechanistically, VEGF induction by IL-17 + soluble IL-6 receptor was mediated by STAT3 and was independent of SP4, despite IL-6-dependent SP4 up-regulation. Promoter analysis identified a VEGF region (-1290/-791) required for responsiveness, containing AP-1 and NF-κB binding sites. STAT3 acted upstream of AP-1 activation through induction of c-FOS, whereas NF-κB contributed directly to promoter activation and indirectly by enhancing IL-6 expression. These findings identify IL-17 as an indirect driver of peritoneal angiogenesis via IL-6 trans-signaling and coordinated STAT3, AP-1, and NF-κB activation.

Aerobic exercise reduces cardiovascular disease risk, with atherosclerosis being a primary contributor. Although circulating extracellular vesicles (EVs) mediate intercellular communication, their role in this process remains unclear. This study aimed to investigate the role of aerobic exercise-derived circulating EVs in mitigating macrophage inflammation and lipid accumulation in an atherosclerotic model. Circulating EVs were isolated from the plasma of exercise-trained and sedentary mice. miRNA profiling of EVs was performed using miRNA arrays and quantitative real-time PCR. Aortic atherosclerosis was assessed by Oil Red O staining, immunofluorescence, and enzyme-linked immunosorbent assay. Functional validation of EV effects was performed through EV labeling, cell transfection, luciferase reporter assays, and flow cytometry. Aerobic exercise slowed the progression of atherosclerosis and altered the miRNA profile of circulating EVs, notably increasing miR-203a-3p and miR-133b-3p expression. EVs from exercise-trained mice inhibited macrophage-driven inflammation and lipid accumulation in vitro and in vivo. Treatment with miR-203a-3p and miR-133b-3p mimics reproduced the anti-atherosclerotic effects, whereas inhibitors of these miRNAs reversed the effects. Mechanistically, miR-203a-3p and miR-133b-3p reduced macrophage inflammation and lipid accumulation by targeting Tlr4 and Insr, respectively, thereby suppressing NF-κB/NLRP3 signaling. Notably, the increased expression of miR-203a-3p and miR-133b-3p was primarily derived from skeletal muscle. These findings highlight a novel mechanism linking aerobic exercise to atherosclerosis via EV-miRNAs, proposing potential therapeutic strategies for atherosclerosis based on exercise-induced circulating EVs miR-203a-3p and miR-133b-3p.

Epidermal keratinocyte differentiation and cell death are tightly regulated to maintain skin homeostasis, and their disruption leads to severe skin disorders. Proteasome dysfunction has been implicated in proteasome-associated autoinflammatory syndromes, which are characterized by dermal inflammation, as well as in keratosis linearis with ichthyosis congenita and sclerosing keratoderma syndrome caused by mutations in proteasome maturation protein. However, skin manifestations in proteasome-related disorders have been attributed to distinct cellular origins, rendering it unclear whether keratinocyte-intrinsic proteasome dysfunction is a common driver of both epidermal pathology and dermal inflammation. Here, it is demonstrated that keratinocyte-specific deletion of the standard proteasome subunit β5 results in neonatal lethality associated with complete loss of the epidermis. Inducible deletion of β5 in basal keratinocytes led to impaired epidermal differentiation, reduced proliferation, and apoptosis, accompanied by accumulation of ubiquitinated proteins without evidence of endoplasmic reticulum stress. Notably, proteasome dysfunction induced epidermal hyperplasia with spongiosis, followed by epidermolysis. Although this genetic alteration was restricted to keratinocytes, pronounced infiltration of neutrophils and macrophages was observed in the dermis, together with elevated expression of inflammatory mediators. These findings demonstrate that proteasome dysfunction in basal keratinocytes disrupts epidermal integrity and triggers secondary dermal inflammation, providing insight into the skin pathology associated with proteasome-related disorders.

The liver serves as a key metabolic and inflammatory organ involved in maintaining homeostasis of different organs and systems. This includes ensuring proper functioning of the central nervous system through a liver-brain axis that has bidirectional communication via signaling mediators and direct neural pathways. Damage to, or disease of, the liver from various etiologies leads to a loss of hepatic function, which then impacts cognitive, motor, and other neurologic functions. Severity, type, and duration of liver dysfunction can impact the brain in different ways via different metabolic and immune challenges. Some of the hepatic factors that impact the brain include ammonia, cytokines, and bile acids. These factors can induce more apparent neurologic changes, such as hepatic encephalopathy, whereas others induce more subtle changes, which typically fall outside of the classical characterization of hepatic encephalopathy. The aim of this review is to outline the current knowledge of the liver-brain axis in pathologic states. Specific emphasis is placed on how loss of liver function leads to systemic metabolic and inflammatory challenges and their subsequent impacts on hepatic and neural pathology. In addition, specific hepatic pathologies most associated with disruptions of the liver-brain axis will be focused on for more detailed analysis.

HIV-associated cardiovascular disease (HIV-CVD) is a major comorbidity in people living with HIV, despite effective antiretroviral therapy (ART). The mechanisms of HIV-CVD have been associated with inflammation, ART toxicity, residual viral replication, and the presence of viral reservoirs, but the data suggest that Pannexin-1 (Panx-1) channels also play a role in HIV residual inflammation, but its contribution to HIV-CVD is unknown. Here, left ventricular heart tissues from acutely SIV-infected nonhuman primates and from chronically HIV-infected humans on suppressive ART were analyzed by mass spectroscopy imaging, showing a significant increase in the levels of arachidonic acid (AA) esterified to phospholipids and the critical enzymes involved in its metabolism, cyclooxygenase-2 (COX-2) and leukotriene A4 hydrolase (LTA4H). Most of the heart AA-associated inflammation induced by the virus was associated with infiltrated macrophages and the main source of AA. Systemic treatment of SIV-infected macaques with the Panx-1 blocker, [10]Panx peptide, prevented monocyte/macrophage infiltration into the tissues, expression of COX-2/LTA4H, and AA-related inflammation. A similar profile of inflammation and increased expression of LTA4H and COX-2 enzymes was also observed in post-mortem human heart tissues from people living with HIV, suggesting that AA inflammation is present during acute and chronic infection. In conclusion, blocking Panx-1 channels after infection may offer a novel therapeutic approach to prevent or ameliorate HIV-CVD.