Inflammation
Abstract
Epigenetic modifications play a crucial role in the pathogenesis of inflammatory bowel disease (IBD) by mediating gene-environment interactions. We previously showed that UHRF1, a central regulator of DNA methylation, contributes to cancer progression; however, its function in IBD remains poorly understood. Here, we revealed that UHRF1 was frequently reduced in inflamed tissues of patients with IBD and that its deficiency exacerbated intestinal epithelial cell (IEC) damage. Through a multilevel approach incorporating human cell models and an intestinal epithelial-specific Uhrf1-KO mouse model, we established UHRF1 as a key mitigator of IBD progression. Mechanistically, UHRF1 bound to the NPY1R promoter, promoted its methylation, and led to transcriptional suppression. The NPY1R upregulation resulting from UHRF1 deficiency attenuated cAMP/PKA/CREB signaling in IECs, thereby enhancing NF-κB activation and subsequent proinflammatory responses, which compromised intestinal epithelial barrier integrity. Furthermore, we identified miR-141 as a negative regulator of NPY1R, highlighting its potential as a therapeutic agent. Collectively, our results identified the UHRF1/NPY1R regulatory axis as a critical epigenetic mechanism in intestinal inflammation and underscored its dual promise for IBD diagnostics and therapy.
Authors
Yanan Han, Lina Sun, Yanxing Liu, Xiaohui Zhang, Hao Liu, Haohao Zhang, Xiaoxia Ren, Fenfan Wang, Huafeng Fan, Jie Chen, Dan Liu, Daiming Fan, Yuanyuan Lu, Xue Bai, Ying Fang, Kaichun Wu, Xiaodi Zhao
Abstract
Authors
Alessandra Ciullo, Xaviar M. Jones, Hiroaki Komuro, Liang Li, Anh Nguyen, Eduardo Marbán, Ahmed Gamal-Eldin Ibrahim
Abstract
Chronic hyperglycemia changes the expression of various transcription factors and mRNA transcripts, which impair the cellular functionality and delayed wound healing. ZEB2 (zinc finger E-box binding homeobox 2), a key transcription factor maintains the tissue specific macrophage identities, however, its role in regulating macrophage polarization during wound healing under hyperglycemic conditions remains unclear. Here, we have found that persistent hyperglycemia increases ZEB2 expression in wound macrophages via histone acetylation, contributing to chronic inflammation, and delayed wound healing. Exposure to high glucose levels activates P300/CBP, a transcriptional coactivator involved in histone acetylation, enhances ZEB2 expression in wound macrophages. The forced expression of ZEB2 shifts macrophage polarity toward a pro-inflammatory state by upregulating myeloid lineage directed transcription factors (MLDTFs). Conversely, silencing Zeb2 at the wound site reduced hyperglycemia induced macrophage inflammation. Topical application of C646, an inhibitor of P300, at the wound edges of streptozotocin induced high-fat diet fed diabetic mice significantly decreased ZEB2 expression, reduced inflammation and accelerated wound healing. Therefore, targeted inhibition of P300 represents a promising therapeutic strategy for improving diabetic wound healing by modulating ZEB2 driven inflammation in wound macrophages.
Authors
Soumyajit Roy, Debarun Patra, Palla Ramprasad, Shivam Sharma, Parul Katiyar, Ashvind Bawa, Kanhaiya Singh, Kulbhushan Tikoo, Suman Dasgupta, Chandan K. Sen, Durba Pal
Abstract
Although renal fibrosis is predominantly driven by the accumulated inflammatory cells that secrete pro-inflammatory factors within the kidney, the key mechanisms underlying macrophage clearance from the kidney are not well understood. The interaction of hyaluronan (HA) with lymphatic endothelial hyaluronan receptor 1 (LYVE1) constitutes a critical initial step in macrophage adhesion and removal by lymphatic vessels. This study investigates alterations in LYVE1 during kidney disease and elucidates its role in macrophage trafficking. Three renal fibrosis models demonstrated a reduction in full-length LYVE1 and an increase in the soluble LYVE1 fragment. Immunostaining of fibrotic kidneys showed significantly reduced expression of soluble LYVE1 compared with intracellular fragment (Cyto-LYVE1), demonstrating ectodomain shedding of LYVE1 in vivo and in vitro. Functionally, human lymphatic endothelial cells exposed to TGF-β1 exhibited significant decrease in macrophage adhesion and transendothelial migration compared to controls. Mechanistic analyses identified increased matrix metalloproteinase (MMP)9 in renal injury as a key upstream regulator of LYVE1 shedding. MMP9 inhibitors reduced LYVE1 shedding, enhanced macrophage adhesion and trafficking, and mitigated macrophage accumulation and disease progression. In conclusion, MMP9-induced LYVE1 shedding is linked to progressive kidney fibrosis and macrophage accumulation. LYVE1 shedding inhibitors offer potential as therapeutic agents for mitigating immune overload and kidney fibrosis.
Authors
Jing Liu, Yuqing Liu, Wenqian Zhou, Saiya Zhu, Jianyong Zhong, Haichun Yang, Annet Kirabo, Valentina Kon, Chen Yu
Abstract
Type 2 diabetic nephropathy (T2DN) is a major complication of type 2 diabetes and a leading cause of chronic kidney disease. This study aimed to explore MYO1C as both a candidate biomarker and elucidate its role as a mechanistic mediator of podocyte injury in T2DN. Using urinary extracellular vesicle RNA biomarkers identified from a training and validation cohort of 33 type 2 diabetes and 40 T2DN patients, we developed a machine learning diagnostic model for T2DN. The model achieved an AUC of 0.877 in validation and performed well in an independent test cohort with an AUC of 0.824. MYO1C was identified as the most influential feature in the final model. Mechanistic investigations in vitro and in vivo revealed that high glucose and high-fat conditions induced podocyte injury, inflammation, and apoptosis, with increased MYO1C expression. MYO1C knockdown in vitro and in vivo reduced podocyte damage and inflammatory responses. MYO1C overexpression enhanced p38, p-CREB, and TNF-α levels, while p38 inhibition mitigated these effects. These findings support MYO1C not only as a potential urinary biomarker for T2DN but also as a key pathogenic driver that promotes podocyte injury via p38 MAPK signaling, thereby highlighting its therapeutic promise.
Authors
Zihao Zhao, Qianqian Yan, Sijie Zhou, Fengxun Liu, Yong Liu, Jingjing Ren, Shaokang Pan, Zhenjie Liu, Dongwei Liu, Zhangsuo Liu, Jiayu Duan
Abstract
The activation of the NLRP3 inflammasome is a pivotal step in hyperinflammation in sepsis; however, the regulatory mechanisms underlying its activation are not fully understood. In this study, we found that 14-3-3ε facilitates NLRP3 inflammasome activation by enhancing NLRP3 K63 deubiquitination and promoting its translocation to the mitochondria-associated ER membranes (MAMs) for full activation. Mass spectrometry revealed that 14-3-3ε binds to NLRP3 in macrophages during sepsis. Plasma 14-3-3ε levels were elevated in patients with sepsis and were positively associated with disease severity. 14-3-3ε promoted NLRP3 inflammasome activation by facilitating NLRP3 aggregation and NLRP3–ASC assembly. The interaction between 14-3-3ε and NLRP3 was dependent on phosphorylation at the S194 site of NLRP3 NACHT domain. The NLRP3–14-3-3ε interaction promoted K63 deubiquitination and enhanced the translocation of NLRP3 to MAMs, which is necessary for full activation of NLRP3 inflammasome. Furthermore, macrophage-conditional KO of 14-3-3ε or treatment with BV02, a 14-3-3 inhibitor, improved the survival rate and alleviated organ injuries in septic mice. Taken together, our data indicate that 14-3-3ε functions as a positive regulator of the NLRP3 inflammasome and could be a target for sepsis treatment.
Authors
Xingyu Li, Siqi Ming, Can Cao, Yating Xu, Jingxian Shu, Ning Tan, Xi Huang, Yongjian Wu
Abstract
Next generation sequencing can identify previously uncharacterized gene expression patterns in disease. Beyond differentially expressed genes analysis, we investigated the ability of within-population diversity (α-diversity) of the transcriptome to reveal additional biological information in alcohol-associated liver disease (ALD), comparing Differential Shannon diversity (DSD) to transcriptome heterogeneity changes. RNA sequencing data from normal livers and patients with early ALD and severe AH were analyzed. α-diversity indices and Percent Shannon Diversity of a gene, which refers to this gene's contribution to total Shannon entropy, were calculated. Ingenuity pathway analysis identified canonical pathways determined by differentially expressed genes (DEG) and DSD approaches. ALD significantly decreased hepatic transcriptome α-diversity correlating with increased relative contribution of select genes. These changes were driven by lower abundance gene expression loss. DEG and DSD analyses showed overlapping genes and canonical pathways, but DSD also identified additional genes and pathways not highlighted by DEG, including fatty acid oxidation, extracellular matrix degradation, and cholesterol metabolism pathways that may represent additional therapeutic targets. Importantly, DSD more effectively identified differences between ASH and AH. Overall, α-diversity analysis revealed that ALD progressively reduces transcriptome heterogeneity, and that DSD provides complementary insights into disease mechanisms missed by standard approaches.
Authors
Sudrishti Chaudhary, Jia-Jun Liu, Silvia Liu, Marissa Di, Juliane I. Beier, Ramon Bataller, Josepmaria Argemi, Panayiotis V. Benos, Gavin E. Arteel
Abstract
Activation of lung fibroblasts in response to epithelial injury and inflammation provokes pulmonary fibrosis (PF). Endogenous molecular brakes counteracting fibroblast activity can be targets for therapies. Preclinical studies of synthetic C-type natriuretic peptide (CNP) indicated that this hormone might provide such a brake. As shown here, CNP exerts antifibrotic effects in cultured lung fibroblasts as well as precision cut lung slices from patients with PF, supporting clinical relevance. Therefore, augmenting or supplementing endogenous CNP could improve the treatment of such patients. To unravel whether paracrine CNP counteracts inflammation-driven PF, we studied mice with fibroblast-restricted knock-out of guanylyl-cyclase-B (GC-B), its cGMP-synthesizing receptor. Fibroblast GC-B-KO mice had enhanced bleomycin-induced lung inflammation, with increased expression of proinflammatory, profibrotic cytokines. Nevertheless, subsequent PF was not exacerbated. Molecular studies revealed that inflammation led to inhibition of CNP signaling in resident myofibroblasts, namely GC-B downregulation and induction of CNP/cGMP-degrading pathways. Despite this, a single subcutaneous injection of the recently developed long-acting CNP analog, MS~[Gln6,14]CNP-38, abrogated experimental lung inflammation and fibrosis. We conclude that CNP signaling in lung fibroblasts has anti-inflammatory and antifibrotic effects. Attenuation of this endogenous brake participates in the pathogenesis of PF and rescuing this pathway with long-acting CNP-analogs may have therapeutic potential.
Authors
Rene Weyer, Katharina Völker, Tamara Potapenko, Lisa Krebes, Marco Abesser, Anna-Lena Friedrich, Eva Lessmann, Ali Khadim, Clemens Ruppert, Elie El Agha, Dalia Sheta, Andreas Beilhack, Daniel V. Santi, Eric L. Schneider, Michaela Kuhn, Swati Dabral
Abstract
Clonal haematopoiesis of indeterminate potential (CHIP) is the expansion of blood stem cells and progeny after somatic mutation. CHIP associates with increased cardiovascular disease (CVD) with inflammation from macrophages a proposed common effector. However, mouse CHIP studies are discordant for clonal expansion and inflammation. Similarly, directionality of association between CHIP and CVD remains debated. We investigated effects of three CHIP mutations on macrophage cytokines, clonal expansion and atherosclerosis in parallel. We find that Tet2 and Dnmt3a mutations increase cytokines and inflammasome activation in Tet2 but decrease in Dnmt3a. However, Jak2 mutant macrophages produced equivalent cytokine as wild-type. In mice, Tet2 mutants clonally expanded, but Dnmt3a and Jak2 mutants didn’t. Expansion was unaffected by systemic inflammation, while hyperlipidemia expanded Tet2-/- cells, but not mono-allelic mutants. Similarly, human Mendelian randomisation showed no effect of serum cytokines or CVD on CHIP risk. Experimental atherosclerosis was increased in females with Tet2 and males with Jak2, but unchanged with Dnmt3a mutations. Together, common CHIP mutations have disparate effects on macrophage cytokines and clonal expansion, and sex-dependent effects on atherogenesis, suggesting a common mechanism across CHIP is unlikely. Thus, CHIP mutations differ in pathophysiology and clinical sequalae across sexes and should be treated as different entities.
Authors
Paul R. Carter, Lauren Kitt, Amanda Rodgers, Nichola Figg, Ang Zhou, Chengrui Zhu, Ziyang Wang, Peter Libby, Stephen Burgess, George S. Vassiliou, Murray CH. Clarke
Abstract
BACKGROUND Icotrokinra is the first and only targeted oral peptide that selectively binds the IL-23 receptor with high affinity to precisely inhibit IL-23 signaling. Icotrokinra demonstrated high rates of complete skin clearance and durable disease control in the phase IIb trial, FRONTIER-1, and its long-term extension, FRONTIER-2, in participants with moderate-to-severe plaque psoriasis. This study evaluated systemic and skin pharmacodynamic response of icotrokinra and its relationship to clinical response in FRONTIER participants.METHODS FRONTIER-1 participants received icotrokinra or placebo for 16 weeks. FRONTIER-2 followed participants for up to 1 year of treatment; placebo participants transitioned to icotrokinra after week 16. Systemic pharmacodynamic changes were assessed in serum through week 52. Skin pharmacodynamic changes were assessed using transcriptomic analysis of skin biopsies and protein quantification in tape-strip samples through week 16.RESULTS Icotrokinra dose-dependently reduced serum levels of the IL-23/IL-17 axis and psoriasis disease biomarkers through week 52, with maximal reductions observed with the highest 100 mg twice-daily dose. Proteomic analyses showed icotrokinra selectively blocked IL-23–driven inflammation without broader impacts on circulating proteins, including serum IL-23 levels. Sixteen weeks of icotrokinra, but not placebo, reduced expression of psoriasis-associated genes in lesional skin. Icotrokinra treatment also reduced psoriasis-relevant proteins in week 16 lesional skin tape-strips to levels comparable to nonlesional samples.CONCLUSION Icotrokinra induced a dose-dependent pharmacodynamic response, with early (week 4) and sustained (week 52) reductions in biomarkers of IL-23 pathway activation and psoriasis disease severity, which correlated with clinical response.TRIAL REGISTRATION ClinicalTrials.gov: NCT05223868, NCT05364554.FUNDING Johnson & Johnson.
Authors
David Strawn, James G. Krueger, Robert Bissonnette, Kilian Eyerich, Laura K. Ferris, Amy S. Paller, Andreas Pinter, Dylan Richards, Elizabeth Y. Chen, Kate Paget, Daniel Horowitz, Roohid Parast, Joshua J. Rusbuldt, Jocelyn Sendecki, Sunita Bhagat, Lynn P. Tomsho, Ching-Heng Chou, Marta E. Polak, Brice E. Keyes, Emily Bozenhardt, Yuan Xiong, Wangda Zhou, Cynthia DeKlotz, Paul Newbold, Dawn M. Waterworth, Megan Miller, Takayuki Ota, Ya-Wen Yang, Monica W.L. Leung, Lloyd S. Miller, Carolyn A. Cuff, Bradford McRae, Darren Ruane, Arun K. Kannan
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