Inflammatory Signaling Pathways Research Articles

Selenium Mitigates Caerulein and LPS-induced Severe Acute Pancreatitis by Inhibiting MAPK, NF-κB, and STAT3 Signaling via the Nrf2/HO-1 Pathway.

Severe acute pancreatitis (SAP) leads to systemic inflammation, resulting in multiorgan damage. Acute lung injury and acute respiratory distress syndrome develop in one-third of SAP patients, with a high mortality rate of 60% due to secondary complications. Patients with pancreatitis often have selenium deficiency, and selenium supplements may provide beneficial effects. This study examined the protective role of selenium in a model of SAP induced by caerulein + lipopolysaccharide (cae + LPS). Mice were administered selenium (1mg/kg) before being challenged with caerulein (6 injections of 50μg/kg) and LPS (10mg/kg). At 3h after the last caerulein injection, blood was collected for estimating pancreatic enzymes and cytokine levels, and the mice were euthanized. We performed morphological and histological studies, measured levels of protease and oxidative stress markers and conducted western blot, ELISA, and RT-qPCR analyses. We examined lung tissue histologically and estimated myeloperoxidase levels. Selenium pretreatment significantly reduced pancreatic enzyme levels such as amylase, lipase, and proteases (specifically MMPs) and reversed tissue injury in the pancreas and lungs caused by cae + LPS. In addition, selenium-treated mice showed decreased levels of inflammatory markers and chemokines. Examination of the downstream inflammatory pathways confirmed the protective effect of selenium, which mediates its anti-inflammatory and antioxidant action by inhibiting the major inflammatory signaling pathways (MAPKs, NF-κB, and STAT3) and activating the phosphorylation of Nrf2 via Nrf2/HO-1 pathways. These findings suggest that selenium may be a potential therapeutic option for treating SAP-associated secondary complications.

MyD88 inhibitor TJ-M2010-5 alleviates spleen impairment and inflammation by inhibiting the PI3K/miR-136-5p/AKT3 pathway in the early infection of Trichinella spiralis.

Trichinella spiralis (T. spiralis) has been reported to induce inflammation, which can cause immune system dysregulation. Myeloid differentiation primary response gene 88 (MyD88) is implicated in inflammation signalling pathways. TJ-M2010-5 is a novel MyD88 inhibitor with remarkable protective effects against several diseases. However, the precise mechanism of TJ-M2010-5's involvement in spleen impairment and inflammation in the early infection of T. spiralis has yet to be fully elucidated. This study analysed histological, inflammation, and macrophage polarisation of the early T. spiralis-infected mice treated with TJ-M2010-5. MyD88 promoter methylation results showed that the methylation levels in the 5 d group were lower compared to the control group (P < 0.05). Furthermore, the methylation led to an imbalance in anti-inflammatory regulation in the infected mice. After TJ-M2010-5 treatment, spleen impairment was reduced. Sequencing analysis showed that TJ-M2010-5 significantly up-regulated 9 and down-regulated 10 miRNAs compared with the 5 d group. A dual-luciferase reporter assay further revealed that miR-136-5p is involved in the TJ-M2010-5 treatment by targeting AKT3. In RAW264.7 cells, TJ-M2010-5 pre-treatment significantly reversed the M1 polarisation and inhibited nitric oxide (NO) production. LC-MS/MS results showed TJ-M2010-5 was hepatosplenic-targeted. In conclusion, the study demonstrates that TJ-M2010-5 could effectively alleviate spleen impairment and reduce inflammation in mice infected with T. spiralis in its early stages by blocking the activation of PI3K/miR-136-5p/AKT3.

Kaempferol: Unveiling its anti-inflammatory properties for therapeutic innovation.

Inflammation, driven by various stimuli such as pathogens, cellular damage, or vascular injury, plays a central role in numerous acute and chronic conditions. Current treatments are being re-evaluated, prompting interest in naturally occurring compounds like kaempferol, a flavonoid prevalent in fruits and vegetables, for their anti-inflammatory properties. This study explores the therapeutic potential of kaempferol, focusing on its ability to modulate pro-inflammatory cytokines and its broader effects on inflammatory signaling pathways. Comprehensive reviews of in vitro and in vivo studies were conducted to elucidate the mechanisms underlying its anti-inflammatory and antioxidant actions. Kaempferol effectively inhibits the production of key inflammatory mediators, including cytokines and enzymes such as COX-2 and iNOS, while also targeting oxidative stress pathways like Nrf2 activation. The compound demonstrated protective effects in various inflammatory conditions, including sepsis, neurodegenerative disorders, cardiovascular diseases, and autoimmune conditions, by modulating pathways such as NF-κB, MAPK, and STAT. Despite its promise, kaempferol's clinical application faces challenges related to its bioavailability and stability, underscoring the need for advanced formulation strategies. These findings position kaempferol as a promising candidate for anti-inflammatory therapy, with the potential to improve patient outcomes across a wide range of inflammatory diseases. Further clinical studies are required to validate its efficacy, optimize dosage, and address pharmacokinetic limitations.

Based on network pharmacology and molecular docking, the mechanism of action of Chinese herbal compound on mycoplasma synovial sac of chicken was studied

Mycoplasma synoviae (MS) is a wall-less pathogen primarily transmitted through the respiratory tract, causing synovitis and airsacculitis in poultry, which leads to substantial economic losses in the poultry industry. China has a long-standing tradition of Chinese medicine with abundant medicinal resources, renowned for its safety, efficacy, and holistic regulatory effects. This study aims to screen a traditional Chinese medicine (TCM) compound with anti-inflammatory and immunoregulatory properties and preliminarily validate its in vitro efficacy against MS infections. Based on the research foundation of this experiment and findings from previous studies, this study utilized network pharmacology analysis and molecular docking techniques to identify the anti-inflammatory and immunoregulatory effects of traditional Chinese medicinal herbs, including Rhizoma Coptidis, Honeysuckle (Flos Lonicerae Japonicae), Radix Codonopsis, and Radix Glycyrrhizae.The primary active components and potential targets were identified using the Traditional Chinese Medicine Systems Pharmacology Database (TCMSP) and other platforms. Protein-protein interaction (PPI) networks, Gene Ontology (GO) functional annotation, and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were employed to identify critical therapeutic targets. The AutoDock software was used for molecular docking between active components and core targets. Subsequently, in vitro experiments were conducted to validate the effects of key active components on MS targets. The analysis revealed that this TCM compound contains 122 active components, including flavonoids (e.g., quercetin, trimethylisoflavone), chromones (e.g., anti-inflammatory coumarin A), and triterpenes (e.g., glycyrrhizic acid B). These components act on 739 pharmacological targets, and Venn analysis identified 23 intersection targets related to MS. Further analysis indicated that STAT3, IL6, and IL1B were potential core targets. KEGG pathway enrichment analysis showed that MAPK, FoxO, and Toll-like receptor signaling pathways played critical roles in the pathology and treatment of MS, while GO analysis emphasized the significance of the NF-κB signaling pathway and VEGF receptor pathway in immune regulation, inflammation, and tissue repair. Molecular docking results demonstrated that lignans and quercetin in this TCM compound exhibited strong binding affinities to IL1B, IL6, and STAT3, potentially modulating these key targets to exert anti-inflammatory and immunoregulatory effects. In vitro experiments further validated the significant inhibitory effects of quercetin and glycyrrhizic acid on MS infection. The findings suggest that this TCM compound may exert therapeutic effects on MS infection by regulating targets such as CASP3, TLR4, STAT3, IL6, and IL1B, and modulating signaling pathways including MAPK, NF-κB, and FoxO.

Kaempferol attenuates experimental autoimmune neuritis through TNFR1/JNK/p38 signaling pathway inhibition.

Kaempferol (Kae) is a flavonoid that has antioxidant, anti-inflammatory and neuroprotective effects. In recent years, there have been increasing reports on viral infection-induced Guillain-Barré syndrome (GBS) with high rates of disability and fatality. Therefore, in order to search for effective peripheral nerve injury repair drugs, we used rats with experimental autoimmune neuritis (EAN) as the typical animal model for GBS, and implemented Kae treatment intervention on EAN rats. Real-time quantitative polymerase chain reaction (qPCR), western blotting (WB) and immunofluorescence (IF) were utilized to detect the changes of inflammatory factors and signaling pathway proteins in peripheral nerve of rats. The impact of Kae on peripheral nerve damage in EAN rats was evaluated in multiple dimensions by clinical symptom score and neuroelectrophysiology examination, and the protective impact and mechanism of Kae on peripheral nerve injury were revealed. Our results showed that Kae increased the expression of sciatic myelin basic protein (MBP), decreased the expression of peripheral nerve macrophage infiltration and inflammatory cytokines, including TNF-α, IL-1β and IL-6, and down-regulated the expression levels of TNFR1. Additionally, it suppressed the activation of the JNK and p38 pathways. It can alleviate sciatic nerve symptoms and pathological injury in EAN rats. Therefore, we believe that Kae can be used as an adjunct drug in the treatment of GBS.

Docetaxel-induced liver and kidney toxicity in rats can be alleviated by suppressing oxidative stress, endoplasmic reticulum stress, inflammation, apoptosis and autophagy signaling pathways after Silymarin treatment.

Approximately 20 million new cancer cases have occurred worldwide, and dose limitation occurs because of the liver and kidney toxicity of chemotherapeutic agents. Inflammation/apoptosis/ROS pathways appear to be activated in the liver and kidney toxicity of chemotherapeutic agents. This study was conducted to investigate the potential effects of silymarin (SLY) use against docetaxel (DTX)-induced liver and kidney damage in rats. For this purpose, 30mg/kg DTX was administered intraperitoneally to Sprague Dawley rats on the first day of the study, followed by SLY (25 or 50mg/kg/day) orally for 7 days. Then, various analyses were performed on liver and kidney tissues using biochemical, molecular and histological methods. The data obtained showed that DTX administration suppressed antioxidant markers and increased lipid peroxidation in liver and kidney tissues. It was also determined that DTX administration triggered markers of endoplasmic reticulum stress, inflammation, apoptosis and autophagy. On the other hand, SLY treatment increased enzymatic and non-enzymatic antioxidant levels and decreased malondialdehyde levels. Additionally, SLY alleviated DTX-induced endoplasmic reticulum stress, inflammation, apoptosis and autophagy in liver and kidney tissues. Immunohistochemical analyses showed that DTX increased the density of 8-OHdG positive cells in liver and kidney tissues, while oxidative DNA damage decreased after SLY administration. ALT, AST, ALP, Urea and Creatinine levels increased in the DTX group and decreased in the SLY treatment groups. In conclusion, DTX administration caused toxicity in liver and kidney tissues and damaged tissue integrity, while SLY treatment alleviated DTX-induced toxicity.

Selected Plant Extracts Regulating the Inflammatory Immune Response and Oxidative Stress: Focus on Quercus robur

Background/Objectives: Inflammation is a vital response of the immune system, frequently linked to the development and progression of numerous chronic and autoimmune diseases. Targeting inflammation represents an attractive strategy to prevent and treat these pathologies. In this context, many pathways, including pro-inflammatory cytokines secretion, NFκB activation, reactive oxygen species (ROS) production, inflammasome activation and arachidonic acid metabolism could be highlighted and addressed. Several plant materials have traditionally been used as effective and non-harmful anti-inflammatory agents. However, well-established scientific evidence is lacking, and their mechanisms of action remain unclear. The current article compares the effects of seven plant extracts, including Quercus robur L. (Oak), Plantago lanceolata L. (narrowleaf plantain), Plantago major L. (broadleaf plantain), Helichrysum stoechas L. (immortelle or helichrysum), Leontopodium nivale alpinum Cass. (edelweiss), Medicago sativa L. (alfafa) and Capsella bursa-pastoris Moench (shepherd’s purse) on different inflammatory pathways. Results: All of the plant extracts significantly affected ROS production, but their action on cytokine production was more variable. As the Quercus robur extract showed the highest efficacy in our models, it was subsequently assessed on several inflammatory signaling pathways. Quercus robur significantly decreased the secretion of IFNγ, IL-17a, IL-12, IL-2, IL-1β and IL-23 in stimulated human leucocytes, and the expression of TNFα, IL-6, IL-8, IL-1β and CXCL10 in M1-like macrophages. Additionally, a significant reduction in PGE2 secretion, COX2, NLRP3, caspase1 and STAT3 expression and NFκB p65 phosphorylation was observed. Conclusions: Our results clearly indicate that Quercus robur has a potent anti-inflammatory effect, making it a promising candidate for both the treatment and prevention of inflammation and related diseases, thereby promoting overall well-being.

Advances in the Regulation of Inflammatory Mediators in Nitric Oxide Synthase: Implications for Disease Modulation and Therapeutic Approaches

Nitric oxide synthases (NOS) are crucial enzymes responsible for the production of nitric oxide (NO), a signaling molecule with essential roles in vascular regulation, immune defense, and neurotransmission. The three NOS isoforms, endothelial NOS (eNOS), neuronal NOS (nNOS), and inducible NOS (iNOS), are tightly regulated by inflammatory mediators and cellular signaling pathways. While physiological NO production is vital for maintaining homeostasis, dysregulated NOS activity contributes to the pathogenesis of numerous diseases, including cardiovascular disorders, neurodegenerative conditions, and cancer. Recent advances in understanding the molecular mechanisms of NOS regulation have unveiled novel therapeutic opportunities, including isoform-specific modulators, upstream pathways, and nanotechnology-enhanced delivery systems. This review highlights these advancements, offering insights into how targeting NOS and its regulatory network can enable precise and effective therapeutic strategies for managing inflammation-driven pathologies.

Regulation of pathologic fibroblast functions in digestive diseases: a role for hypoxia?

The recent uncovering of fibroblast heterogeneity has given great insight into the versatility of the stroma. Among other cellular processes, fibroblasts are now thought to contribute to the coordination of immune responses in a range of chronic inflammatory diseases and cancer. While the pathologic roles of myofibroblasts, inflammatory fibroblasts and cancer associated fibroblasts in disease are reasonably well understood, the mechanisms behind their activation remain to be uncovered. In the gastrointestinal (GI) tract, several interleukins and tumour necrosis factor superfamily members have been identified as possible mediators driving the acquisition of inflammatory as well as fibrotic properties in fibroblasts. In addition to cytokines, other microenvironmental factors such as nutrient and oxygen availability are likely contributors to this process. In this respect, the phenomenon of low cellular oxygen levels known as hypoxia is common in a plethora of GI diseases. Indeed, the crosstalk between hypoxia and inflammation is well-documented, with an abundance of studies suggesting that oxygen-sensing enzymes may have regulatory effects on inflammatory signalling pathways such as NF-κB. However, the impact that this has in GI fibroblasts in the context of chronic diseases has not been fully uncovered. Here we discuss the role of fibroblasts in GI diseases, the mediators that have emerged as regulators of their functions and the potential impact of hypoxia in this process, highlighting areas that require further investigation.

Nitrate induced hepatic fibrosis in tadpoles of Bufo gargarizans by mediating alterations in toll-like receptor signaling pathways.

The nitrate pollution has become an increasingly serious environmental problem worldwide, and the toxic effects of elevated nitrate levels in the environment on aquatic animals remain to be elucidated. The purpose of the present study was to investigate the mechanisms of liver injury to tadpoles after exposure to nitrate from embryonic to metamorphic climax and to assess the recovery process of liver function after cessation of exposure. In the group with continuous nitrate exposure, the livers and thyroid of tadpoles showed remarkably histological lesions, of this with structural disorganization of the hepatocytes, cellular atrophy, and fibrosis, as well as significant reduction in the follicular and colloidal area of the thyroid. Meanwhile, the expression levels of genes related to inflammatory signaling pathways, such as TLR2, TLR6 and NF-κB, were significant elevated. After termination of exposure at Gs23, liver damage (histologic, ultrastructural, and molecular levels) was almost completely recovered, whereas thyroid gland damage was irreversible. Overall, this study shed light on the harmful effects of nitrate pollution on amphibian health and emphasizes the importance of controlling nitrate emissions in the environment.

Pathophysiology of Benign Prostatic Hyperplasia: Cellular and Molecular Mechanisms

Benign prostatic hyperplasia (BPH) is a prevalent condition among aging males, characterized by non-malignant enlargement of the prostate gland, which can lead to lower urinary tract symptoms (LUTS) and a significant reduction in quality of life. This review explores the cellular and molecular mechanisms underpinning the pathophysiology of BPH, highlighting the interplay of hormonal, inflammatory, and growth factor signaling pathways. Testosterone and dihydrotestosterone (DHT) serve as pivotal regulators of prostate growth, driving hyperplasia through androgen receptor-mediated transcriptional activity. Additionally, chronic inflammation, mediated by immune cell infiltration and cytokine release, contributes to tissue remodeling and stromal proliferation. Dysregulated growth factors such as fibroblast growth factors (FGFs) and transforming growth factor-beta (TGF-β) further amplify cellular proliferation and extracellular matrix deposition. Emerging evidence underscores the role of oxidative stress and mitochondrial dysfunction in exacerbating prostatic cellular senescence and genomic instability. This review also addresses the influence of stromal-epithelial interactions and the contribution of stem/progenitor cell niches in maintaining aberrant growth. Understanding these intricate mechanisms provides a foundation for identifying novel therapeutic targets aimed at mitigating BPH progression and associated symptoms. Keywords: Benign prostatic hyperplasia, cellular mechanisms, hormonal regulation, inflammation, growth factors, molecular pathways, therapeutic targets.

Glabridin Suppresses Macrophage Activation by Lipoteichoic Acid In Vitro: The Crucial Role of MAPKs-IL-1β-iNOS Axis Signals in Peritoneal and Alveolar Macrophages

Inflammation, a fundamental response to infection and injury, involves interactions among immune cells and signaling molecules. Dysregulated inflammation contributes to diseases such as autoimmune disorders and cancer. Interleukin-1 beta (IL-1β), produced by macrophages in response to lipoteichoic acid (LTA) from Gram-positive bacteria, is a key inflammatory mediator. Glabridin (GBD), a bioactive compound from licorice root, exhibits anti-inflammatory properties. This study investigates GBD’s effects on LTA-induced proinflammatory signaling in RAW 264.7 murine macrophages and alveolar macrophages, MH-S, focusing on IL-1β expression and signaling pathways. Cell viability assays confirmed that 20 μM GBD was non-cytotoxic. Confocal microscopy and quantitative PCR showed that GBD significantly reduced IL-1β fluorescence intensity, mRNA, and protein levels. GBD also inhibited inducible nitric oxide synthase (iNOS) expression and nitric oxide (NO) production. Further analysis revealed that GBD suppressed NF-κB p65 nuclear translocation and selectively modulated MAPK pathway activation by reducing JNK and p38 MAPK phosphorylation without affecting ERK. Studies using specific inhibitors demonstrated that IL-1β production reduction was mechanistically linked to MAPK pathway inhibition. These findings highlight GBD’s potential as a therapeutic agent for inflammatory diseases through its ability to modulate critical inflammatory mediators and signaling pathways.

MA104 cell line is permissive for human bocavirus 1 infection.

Human bocavirus 1 (HBoV1) has appeared as an emerging pathogen, causing mild to life-threatening respiratory tract infections, acute otitis media, and encephalitis in young children and immunocompromised individuals. The lack of cell lines suitable for culturing replicative viruses hinders research on HBoV1. Here, we characterized the susceptibility to HBoV1 of 29 human and 7 animal cell lines, and identified a permissive cell line, MA104. The complete HBoV1 life cycle was achieved in MA104 cells, including viral entry, complete replication, and infectious progeny virion production. Additionally, the suppression of the interferon pathway facilitated the viral genome replication in MA104 cells. RNA-sequencing showed that innate immunity, inflammation, the PI3K-Akt and MAPK signaling pathways, and the cellular membrane system were mobilized in response to HBoV1 infection. Overall, our study is the first to identify a cell line, MA104, that supports the complete HBoV1 life cycle, which will promote research on HBoV1 virology and pathogenesis and benefit drug and vaccine development.IMPORTANCEHBoV1 is an emerging pathogen that mainly causes respiratory tract infections, while the lack of cell lines suitable for culture replicative viruses hindered research on HBoV1. Here, we identify a permissive cell line for HBoV1 infection, MA104, and reveal that the complete life cycle of HBoV1 was supported in MA104 cells. Our findings provide a suitable cell model for the study of HBoV1 and explore its application for antiviral drug evaluation, which is vital for research on HBoV1 virology and pathogenesis, as well as for drug and vaccine development.

Development of compounds for targeted degradation of mammalian cryptochrome proteins.

The mammalian cryptochrome proteins (CRY1 and CRY2) are transcriptional repressors most notable for their role in circadian transcriptional feedback. Not all circadian rhythms depend on CRY proteins, however, and the CRY proteins are promiscuous interactors that also regulate many other processes. In cells with chronic CRY deficiency, protein homeostasis is highly perturbed, with a basal increase in cellular stress and activation of key inflammatory signalling pathways. Here, we developed tools to delineate the specific effects of CRY reduction, rather than chronic deficiency, to better understand the direct functions of CRY proteins. Performing a bioluminescence screen and immunoblot validation, we identified compounds that resulted in CRY reduction. Using these compounds, we found that circadian PERIOD2 (PER2) protein rhythms persisted under CRY-depleted conditions. By quantitative mass spectrometry, we found that CRY-depleted cells partially phenocopied the proteomic dysregulation of CRY-deficient cells, but showed minimal circadian phenotypes. We did, however, also observe substantial off-target effects of these compounds on luciferase activity and could not ascertain a specific mechanism of action. This work therefore highlights both the utility and the challenges of targeted protein degradation and bioluminescence reporter approaches in disentangling the contribution of CRY proteins to circadian rhythmicity, homeostasis and innate immune regulation.This article is part of the Theo Murphy meeting issue 'Circadian rhythms in infection and immunity'.

P0175 A new blocker of endothelial dysfunction ameliorates colitis independently of IL-10 by regulating both barrier function and the recruitment of immune cells

Abstract Background Inflammatory bowel diseases (IBDs) like Crohn’s disease (CD) and ulcerative colitis (UC) are chronic gastrointestinal disease with complex pathogenesis, leading to a lack of effective treatments. The efficacy of CU104, a new blocker of endothelial dysfunction,1 in other IBD models with a CD-like phenotype2 and its specific mechanism of action in colitis are still unknown. Methods To evaluate the therapeutic potential of CU104, we induced colitis using dextran sodium sulfate (DSS) in IL-10 knockout mice3 and assessed its effectiveness. Additionally, we used Caco-2, HCT-116, and HT-29 cells to investigate its impact on intestinal barrier function, inflammatory signal pathway, actin dynamics,4 and gene expression through FITC-dextran permeability, trans-epithelial electrical resistance (TEER), reporter gene, gene expression profiling, and immune assays. Results CU104 demonstrated therapeutic efficacy in DSS-induced colitis in IL-10 KO mice by potently suppressing innate immune activation, vascular and intestinal barrier dysfunction, and immune cell recruitment. Mechanistically, CU104 inhibited the activation of nuclear factor kappa-light-chain-enhancer of activated B cell (NF-κB) and interferon regulatory factor (IRF),5 as well as the ezrin/radixin/moesin (ERM) signaling pathways6 in vitro and in vivo, which play critical roles in maintaining barrier integrity and regulating immune cell recruitment during inflammation by regulating actin dynamics. Conclusion Our findings suggest that CU104, a pseudo-sugar derivative of cholesterol that regulates actin dynamics and inflammatory signaling, could be a promising new treatment for CD along with UC.

P0132 ACSS2 inhibition alleviates inflammatory signaling and improves epithelial integrity in Inflammatory Bowel Disease in vitro models

Abstract Background Inflammatory bowel disease (IBD), encompassing Ulcerative Colitis (UC) and Crohn’s Disease (CD), is marked by chronic gastrointestinal inflammation stemming from genetic, environmental, immunological, and microbiota factors1. Acetyl-CoA Synthetase Short Chain Family Member 2 (ACSS2) converts acetate into acetyl-CoA and is primarily cytosolic, but translocates to the nucleus under metabolic stress, where it regulates gene transcription and cellular processes2. Although the gastrointestinal microbiota influences acetate levels, the role of ACSS2 in colitis and intestinal inflammation remains poorly understood3. Methods To evaluate ACSS2's role in IBD, we employed in vitro IBD models using Caco-2 and HT-29 intestinal epithelial cell lines. ACSS2 activity was inhibited with an ACSS2 inhibitor, followed by inflammatory stimulation with 100 ng/ml Tumor Necrosis Factor-α (TNF-α) for 30 minutes or 1% Dextran Sodium Sulfate (DSS) for 6 hours. Protein expression levels were assessed via Western blot and immunohistochemistry (IHC) on paraffin-embedded samples from UC patients. The effects of ACSS2 inhibition on inflammatory signaling pathways and cell integrity were assessed using RT-qPCR, immunoblotting, and transepithelial electrical resistance (TEER) measurements. Results Treatment of Caco-2 and HT-29 cells with DSS or TNF-α induced upregulation of ACSS2 protein levels compared to controls. IHC analysis of 30 paired paraffin-embedded colon samples from UC patients revealed higher ACSS2 expression and nuclear localization in inflamed sections compared to non-inflamed regions. Inhibition of ACSS2 activity in stimulated Caco-2 and HT29 cells led to a significant decrease in the gene expression levels of pro-inflammatory cytokines such as Interleukin 8 (IL-8), IL-1β and TNF-α. Additionally, immunoblotting demonstrated reduced phosphorylation of p65 and ERK/MEK, indicating suppression of NF-κB and MAPK inflammatory signaling pathways. To assess the effect of ACSS2 inhibition on cell integrity, TEER assays revealed that ACSS2 inhibition preserved cell integrity in DSS-treated monolayers, accompanied by increased expression of tight junction proteins Occludin and ZO-1, suggesting improved epithelial integrity in the inflammatory context. Conclusion Our findings demonstrate a pro-inflammatory role for ACSS2 in IBD, mediated through its involvement in inflammatory signaling and epithelial integrity. These results highlight ACSS2 as a potential therapeutic target for IBD and warrant further investigations in more advanced models, including human-derived intestinal organoids and in vivo systems, to validate its role in disease pathogenesis and therapeutic potential.

P0050 4-Octyl Itaconate Protects Against Colitis by Modulating Neutrophil Function and Enhancing Intestinal Epithelial Barrier Integrity

Abstract Background Inflammatory bowel disease (IBD) is a complex gastrointestinal condition marked by immune system dysfunction and intestinal barrier damage. The pathogenesis involves a mix of genetic, environmental, and immunological factors, with the potential for itaconic acid derivatives like 4-Octyl itaconate (4-OI) to modulate immune responses and offer therapeutic benefits. Methods The study utilized a mouse model of acute colitis induced by dextran sulfate sodium (DSS) to evaluate the effects of 4-OI. C57BL/6J mice were divided into control and treatment groups, with interventions including 4-OI administration. Lamina Propria Mononuclear Cells (LPMC) isolation, flow cytometry, neutrophil studies, Western blot, qRT-PCR, and RNA-seq profiling were conducted to assess changes in immune cell populations, protein and gene expression, and global transcriptional responses. Results 4-OI treatment resulted in the amelioration of DSS-induced colitis, evidenced by improved colonic epithelial barrier function, reduced secretion of pro-inflammatory factors, and dampened inflammatory signaling pathways. Notably, 4-OI reduced neutrophil infiltration and activity, including the formation of neutrophil extracellular traps (NETs), with minimal impact on T cells and macrophages. Moreover, we discovered that 4-OI primarily targeted the acute phase of the disease, with less satisfactory effects on alleviating chronic colitis models. Conclusion 4-OI demonstrates potential as a therapeutic agent in acute colitis by preserving the intestinal epithelial barrier and modulating neutrophil activity. While the study provides evidence of 4-OI's effects on neutrophils and epithelial cells, further research is necessary to understand its mechanisms, particularly regarding chronic colitis and potential clinical applications.

Non-Canonical TERT Activity Initiates Osteogenesis in Calcific Aortic Valve Disease.

Calcific aortic valve disease is the pathological remodeling of valve leaflets. The initial steps in valve leaflet osteogenic reprogramming are not fully understood. As TERT (telomerase reverse transcriptase) overexpression primes mesenchymal stem cells to differentiate into osteoblasts, we investigated whether TERT contributes to the osteogenic reprogramming of valve interstitial cells. Human control and calcific aortic valve disease aortic valve leaflets and patient-specific human aortic valve interstitial cells were used in in vivo and in vitro calcification assays. Loss of function experiments in human aortic valve interstitial cells and cells isolated from Tert-/- and Terc-/- mice were used for mechanistic studies. Calcification was assessed in Tert+/+ and Tert-/- mice ex vivo and in vivo. In silico modeling, proximity ligation, and coimmunoprecipitation assays defined novel TERT interacting partners. Chromatin immunoprecipitation and cleavage under targets and tagmentation sequencing defined protein-DNA interactions. TERT protein was highly expressed in calcified valve leaflets without changes in telomere length, DNA damage, or senescence markers, and these features were retained in isolated primary human aortic valve interstitial cells. TERT expression increased with osteogenic or inflammatory stimuli, and knockdown or genetic deletion of TERT prevented calcification in vitro and in vivo. Mechanistically, TERT was upregulated via NF-κB and required to initiate osteogenic reprogramming, independent of its canonical reverse transcriptase activity and the long noncoding RNA TERC. TERT exerts noncanonical osteogenic functions via binding with STAT5 (signal transducer and activator of transcription 5). Depletion or inhibition of STAT5 prevented calcification. STAT5 was found to bind the promoter region of RUNX2 (runt-related transcription factor 2), the master regulator of osteogenic reprogramming. Finally, we demonstrate that TERT and STAT5 are upregulated and colocalized in calcific aortic valve disease tissue compared with control tissue. TERT's noncanonical activity is required to initiate calcification. TERT is upregulated via inflammatory signaling pathways and partners with STAT5 to bind the RUNX2 gene promoter. These data identify a novel mechanism and potential therapeutic target to decrease vascular calcification.

Genetic and pharmacological targeting of HINT2 promotes OXPHOS to alleviate inflammatory responses and cell necrosis in acute pancreatitis.

The necrosis of pancreatic acinar cells is a key molecular event in the progression of acute pancreatitis (AP), with disturbances in mitochondrial energy metabolism considered to be a direct causative factor of acinar cell necrosis. Histidine triad nucleotide-binding protein 2 (HINT2) has been implicated in the development of various diseases, whereas its involvement in the progression of AP remains unclear. This study aims to investigate the role of HINT2 in AP. HINT2 expression in pancreatic tissues was significantly downregulated after AP. The results of glutathione-S-transferase (GST) pull-down and proteomics analyses revealed the involvement of HINT2 in regulating mitochondrial oxidative phosphorylation (OXPHOS) in AP mice. Moreover, lentivirus-mediated HINT2 overexpression not only alleviated AP-induced ATP depletion, but also relieved inflammatory responses and cell necrosis. Mechanistically, HINT2 interacted with cytochrome C oxidase II (MTCO2) to promote mitochondrial OXPHOS, thereby reducing ROS accumulation and inhibiting the activation of inflammatory signaling pathway. Besides, HINT2 act as a direct pharmacological target of Emo to elicit protective effects on AP. Importantly, Emo upregulates the expression of HINT2 and OXPHOS complex proteins and enhances the interaction between HINT2 and MTCO2. Furthermore, CRISPR/Cas9-mediated HINT2 knockout significantly impaired the protective effects of Emo against AP-induced mitochondrial energy metabolism disorders, inflammatory responses, and acinar cell necrosis. Overall, these results uncover a previously unexplored role for HINT2 in maintaining mitochondrial energy metabolism in pancreatic acinar cells and reveals novel mechanism and target for Emo-mediated AP remission.

Interleukin 1 receptor associated kinase 1 gene polymorphism association with risk of rheumatological diseases in Egyptian population.

Interleukin-1 receptor-associated kinase1 (IRAK1) plays a considerable role in the inflammatory signaling pathway. The current study aimed to identify any association between (rs1059703) single nucleotide polymorphism (SNP) and vulnerability to rheumatological diseases in the pediatric and adult Egyptian population. The current study included four patient groups: adult Systemic lupus erythematosus (SLE), Rheumatoid arthritis (RA), juvenile systemic lupus erythematosus (JSLE), and juvenile idiopathic arthritis (JIA). Two healthy matched age and sex groups were included as controls. Genotypes of IRAK1 (rs1059703) SNP in patients and controls were determined using the TaqMan allelic discrimination method. The frequency of AA homozygous genotype and allele A of IRAK1 (rs1059703) SNP is higher in adult SLE patients compared to adult healthy controls (p-value < 0.005). No similar association was detected regarding RA, JSLE, or JIA. However, JSLE patients carrying the A allele have a higher SLE International Collaborating Clinics (SLICC) damage index (SDI) SDI score and a higher stage of renal biopsy than those carrying the G allele (p-value < 0.005). Carriers of the A allele and its homozygous genotype of rs1059703 SNP are more prone to develop SLE in adult life and to have a more severe form of the disease in children in Egypt. No significant association was detected between this SNP and RA or JIA.