IL-6 Signaling Research Articles

Macrophage-mediated interleukin-6 signaling drives ryanodine receptor-2 calcium leak in postoperative atrial fibrillation

Abstract Background Postoperative atrial fibrillation (poAF) is self-limited AF that occurs within days after cardiac surgery in one-third of patients. Clinical and preclinical studies have demonstrated that the magnitude of the perioperative increase in systemic inflammation, in particular mediated by interleukin (IL)-6, correlates with poAF risk. However, no studies to-date have mechanistically linked IL-6 signaling to fundamental arrhythmia mechanisms or identified the specific cell types driving postoperative atrial IL-6 signaling. Methods We performed single-cell RNA sequencing (scRNAseq), followed by pseudotime trajectory and cell-cell communication analyses on atrial non-myocytes comparing mice with and without poAF. We followed up our scRNAseq findings with pharmacologic and genetic approaches in mice to validate pathways related to macrophage-mediated IL-6 signaling. We used confocal imaging to assess calcium-signaling mechanisms at the single atrial cardiomyocyte (ACM) level and performed parallel patch-clamp studies in isolated human ACMs as well as biochemical analyses of human atrial tissue to assess the translational relevance of our findings. Results Our scRNAseq results demonstrated macrophages to be the most prominently altered cell type in the atria of mice with poAF. Pseudotime trajectory analyses revealed IL-6 to be one of the top inflammatory pathways implicated in macrophage transcriptional state. Indeed, both macrophage depletion and conditional knockout of IL-6 receptors in macrophages were sufficient to prevent poAF. We found that inhibition of STAT3, which is downstream of the IL-6Ra, with FDA-approved phospho-STAT3 inhibitor TTI-101 prevented poAF in mice. Lastly, we demonstrate that enhanced STAT3 activity in poAF promotes arrhythmogenic Ca2+ sparks and waves through ryanodine receptor-2 dysfunction, and that CaMKII inhibition is sufficient to ameliorate Ca2+ mishandling at the single atrial myocyte level. Conclusions Taken together, we use an integrated approach incorporating mouse and human biochemical, functional, and single-cell sequencing data to demonstrate that infiltrating atrial macrophages are fundamentally required for poAF. IL-6 was found to be a critical pathway upregulated in poAF leading to downstream ryanodine receptor-2 dysfunction and atrial arrhythmogenesis. Our findings portend significant therapeutic utility by providing robust mechanistic evidence that targeting the IL-6 axis may be used for poAF prevention and treatment in a clinically amenable timeframe.

Paired single-cell RNA sequencing and T cell receptor sequencing reveals both pro- and anti-inflammatory roles of T cells in patients with calcific aortic valve disease

Abstract Background Calcified aortic valve disease (CAVD) is a chronic unresolvable inflammatory disorder that affects 25% of adults over 65 years old, leading to aortic stenosis, heart failure, and death [1]. Since the molecular mechanisms of its pathogenesis are not well understood, therapies to treat root causes of the disease remain to be developed, with valve replacement as the major intervention strategy currently. Increasing evidence indicates that substantial T cells infiltrate in the aortic valve during calcification, and clonal expanded CD8+ T cells have been identified in the calcificed aortic valve by bulk T cell receptor (TCR) repertoire sequencing [2]. Purpose To decipher T cell heterogenity and understand the precise mechanisms of T cell subsets involving CAVD progression as a basis for novel therapeutic targets. Methods In Cohort 1, we collected aortic valves from CAVD (n=3) and healthy (n=2) patients for single-cell RNA sequencing (scRNA-seq). In Cohort 2, we performed paired scRNA-seq and TCR sequencing (scTCR-seq) on aortic valves obtained from CAVD (n=3) and healthy (n=3) patients to evaluate both gene expression and clonality. Pathway enrichment analysis and cell-cell interaction analysis elucidated the function of T cells in the calcificied valves. Immunohistochemistry and fluorescence-activated cell sorting were recruited to verify the key findings. Results scRNA-seq demonstrated a conversion from anti-inflammatory regulatory T (Treg) cells towards pro-inflammatory T helper 17 (Th17) cells in the calcificied aortic valve. Paired scRNA-seq and scTCR-seq revealed CAVD-related signaling pathways (osteoclast differentiation, NOD-like receptor signaling pathways, IL-17 signaling pathways) significantly upregulated in highly expanded CD8+ T cells in the calcified valve, with upregulation of pro-inflammatory mediators such as IFNG, CCL4 and CCL5, suggesting pro-inflammation functions in clonally expanded T cells. Moreover, we characterized tissue-resident memory T cells, which resembled similar transcriptome and TCR clonality as exhausted T cells in calcified valves. These cells up-regulated anti-inflammation-related transcriptomes but their cellular fraction decreased in calcified valves, implying anti-inflammatory functions of these tissue-resident memory and exhausted T cells. Conclusion This study elucidates transcriptomic and immune profiling of T cells in the calcified aortic valve, therefore shedding light on the pathophysiological mechanisms underlying aortic valve calcification from the novel perspective of tissue-specific T lymphocytes, providing promising targets for immune checkpoint-based therapeutic interventions.

Human coronary blood single-cell sequencing combined with exosome proteomic profiling reveals the molecular mechanism of recurrent in-stent restenosis (R-ISR)

Abstract Background Percutaneous coronary intervention (PCI) is recognized as the core treatment for symptomatic myocardial ischemia and acute coronary syndrome (ACS). However, the complex pathogenesis of recurrent in-stent restenosis (R-ISR) after stent implantation is still insufficiently understood. Purpose This study reports the first single-cell RNA sequencing and proteomic profiling to characterize pathogenesis of R-ISR in humans. Methods To reveal the pathophysiology and molecular mechanism of R-ISR, we performed single-cell RNA sequencing to identify RISR-induced changes in transcriptional landscape in coronary blood mononuclear cell composition. Besides, proteomic profiling of human coronary plasma-derived exosomes was used to further screen different proteins. Transmission electron microscopy (TEM), nanoparticle tracking analysis (NTA) and western blot analysis were performed to identify exosomes. In vitro cell biology experiments were used to validate the discoveries of bioinformatics analysis. Results Compared with normal subjects, the percentage of FCGR3B high monocytes, memory T cells and plasmacytoid dendritic cells (DCs) was increased in R-ISR. Furthermore, we observed a marked increase in the expression of JUN, FOS, CXCL8, S100A8 enriched in the IL-17 signaling pathway that is known to play a crucial role in activating inflammation, mediating immune response, and even maintaining inflammation to chronicity. According to in vitro experiments, the co-cultured system demonstrated that FCGR3B high monocytes isolated from RISR patients activated the expression of inflammatory factors in endothelial cells (ECs), such as IL-1β, IL-6 and TNF-α. Inflammatory activated endothelial cells could release a large amount of exosomes, proteomic profiling of exosomes isolated from ECs observed a significant upregulation of MYLK expression, which could promote proliferation and migration of vascular smooth muscle cells (VSMCs) by activating VEGFR-2 signaling pathway. Conclusions Our study reveals a novel subset of FCGR3B high monocytes in R-ISR patients that could activate ECs inflammation via IL-17 signaling pathway. Activated ECs release exosomes rich in MYLK, which promote proliferation and migration of VSMCs, ultimately leading to repeated restenosis.

IL-33 Increases the Magnitude of the Tissue-Resident Memory T Cell Response in Intestinal Tissues during Local Infection.

IL-33 plays an important role in the early programming of CD8 T cells; however, its contribution to the differentiation of tissue-resident memory T cells invivo remains poorly defined. After infection of mice with Yersinia pseudotuberculosis, IL-33 expression was increased in the intestinal tissue, and this coincided with the expression of ST2 on T cells infiltrating the intestinal epithelium and lamina propria. Blocking IL-33 signaling after T cell infiltration of the intestinal tissue did not significantly impact the number or phenotype of tissue-resident memory T cells generated. However, overexpression of ST2 on T cells was able to increase expression of TCF1 and T cell number in the intestine compared with the lymphoid organs during infection. We also observed that enhanced accumulation and maintenance of ST2-overexpressing cells in the intestine postinfection were resolved. This points to a role for IL-33 in increasing the number of T cells that commit to intestinal tissue residency invivo.

Interleukin-6 signalling, lipoprotein (a) lowering and cardiovascular disease: a mendelian randomisation study

Abstract Background Elevated lipoprotein(a) (Lp[a]) levels and chronic low-grade inflammation play causal roles in cardiovascular disease (CVD) development, representing promising targets for managing residual risk. CVD prevention trials are currently assessing the efficacy of IL-6 pathway inhibition in ameliorating chronic pro-atherogenic inflammation. Lp(a) increases in response to interleukin 6 (IL-6) and acute inflammatory states, and Lp(a) itself induces an inflammatory response that accelerates atherosclerosis. Recent studies indicate that IL-6-receptor inhibitors may lower Lp(a) levels and reduce inflammation, potentially decreasing CVD risk in an additive manner. Purpose This drug-target Mendelian Randomisation (MR) study aims to elucidate the on-target effects of pharmacological IL-6R and LPA inhibition on CVD and explore the relationship between downregulated IL6R signalling and Lp(a) levels. Methods Independent genetic variants associated with C-reactive protein levels from around the IL6R gene locus, and Lp(a) lowering variants from around the LPA gene locus were utilised to assess the effect of genetically proxied IL6R and LPA inhibition on CVD risk in large genomic consortia. Two-step cis-MR was then employed to estimate the effect of lower genetically predicted IL6R signalling on CVD, after adjusting for its influence on Lp(a) levels. Results Genetically proxied LPA inhibition was associated with reduced odds of coronary artery disease (CAD) (OR 0.88, 95% CI 0.86-0.89), ischaemic stroke (IS) (OR 0.98, 95% CI 0.96-1.00), cardioembolic stroke (OR 0.95, 95% CI 0.92-0.97), heart failure (HF) (OR 0.96, 95% CI 0.92-1.00), and aortic stenosis (OR 0.88, 95% CI 0.85-0.91). IL6R inhibition was associated with reduced odds of CAD (OR 0.76, 95% CI 0.68-0.86), IS (OR 0.89, 95% CI 0.80-0.98), small vessel stroke (SVS) (OR 0.72, 95% CI 0.59-0.89), large artery stroke (LAS) (0.61, 95% CI 0.48-0.78) and atrial fibrillation (OR 0.73, 95% CI 0.65-0.83). Furthermore, downregulated IL6R signalling was associated with lower Lp(a) levels (SD change -0.04, 95% CI -0.08,-0.01). In two-step cis-MR, Lp(a) levels partially mediated the total effect of IL6R inhibition on CAD (proportion-mediated = -11.33%, 95% CI -11.35, -11.31%) and LAS (proportion mediated = -4.19%, 95% CI -4.21, -4.17%), but had little effect on IS (proportion-mediated = -1.78%, 95% CI -1.80, -1.76%), SVS (proportion-mediated = -2.50%, 95% CI -2.52, -2.48%), or atrial fibrillation (proportion-mediated = -0.20%, 95% CI -0.22, -0.18%). Conclusion IL6R and Lp(a) inhibition are independently associated with reduced risk of CVD. Furthermore, IL6R inhibition is associated with lower Lp(a) and its effect on CVD is independent of its Lp(a)-lowering effects. Targeting the IL6 signalling pathway offers a promising approach to mitigate residual CVD risk in individuals with elevated Lp(a) levels. Future trials should investigate the additive effects of combined IL-6 inhibition and Lp(a) lowering therapies.

Machine learning-based new classification for immune infiltration of gliomas.

Glioma is a highly heterogeneous and poorly immunogenic malignant tumor, with limited efficacy of immunotherapy. The characteristics of the immunosuppressive tumor microenvironment (TME) are one of the important factors hindering the effectiveness of immunotherapy. Therefore, this study aims to reveal the immune microenvironment (IME) characteristics of glioma and predict different immune subtypes using machine learning methods, providing guidance for immune therapy in glioma. We first performed unsupervised cluster analysis on the genes and arrays of 693 gliomas in CGGA database and 702 gliomas in TCGA database. Then establish and verify the classification model through Machine Learning (ML). Then, use DAVID to perform functional enrichment analysis for different immune subtypes. Next step, analyze the immune cell distribution, stemness maintenance, mesenchymal phenotype, neuronal phenotype, tumorigenic cytokines, molecular and clinical characteristics of different immune subtypes of gliomas. Firstly, we divide the IME of gliomas in the CGGA database into four different subtypes, namely IM1, IM2, IM3, and IM4; similarly, the IME of gliomas in the TCGA database can also be divided into four different subtypes (IMA, IMB, IMC, and IMD). Next, based on ML, we developed a highly reliable model for predicting different immune subtypes of glioma. Then, we found that Monocytic lineage, Myeloid dendritic cells, NK cells and CD8 T cells had the highest enrichment in the IM1/IMD subtypes. Cytotoxic lymphocytes were highest expressed in the IM4/IMA subtypes. Next step, Enrichment analysis revealed that the IM1-IMD subtypes were mainly closely related to the production and secretion of IL-8 and TNF signaling pathway. The IM2-IMB subtypes were strongly associated with leukocyte activation and NK cell mediated cytotoxicity. The IM3-IMC subtypes were closely related to mitotic nuclear division and mitotic cell cycle process. The IM4-IMA subtypes were strongly associated with Central Nervous System (CNS) development and striated muscle tissue development. Afterwards, Single sample gene set enrichment analysis (ssGSEA) showed that stemness maintenance phenotypes were mainly enriched in the IM4/IMA subtypes; Neuronal phenotypes were closely associated with the IM2/IMB subtypes; and mesenchymal phenotypes and tumorigenic cytokines were highly correlated with the IM2 /IMB subtypes. Finally, we found that compared with patients in the IM2/IMB and IM4/IMA subtypes, the IM1/IMD and IM3/IMC subtypes have the highest proportion of GBM patients, the shortest average overall survival of patients and the lowest proportion of patients with IDH mutation and 1p36/19q13 co-deletion. We developed a highly reliable model for predicting different immune subtypes of glioma by ML. Then, we comprehensively analyzed the immune infiltration, molecular and clinical features of different immune subtypes of gliomas and defined gliomas into four subtypes: immunogenic subtype, adaptive immune resistance subtype, mesenchymal subtype, and immune tolerance subtype, which represent different TMEs and different stages of tumor development.

A Network Pharmacology Study on Mechanism of Total Flavonoids of Hippophae Rhamnoides in Treating Allergic Dermatitis via Regulation of IL-17 Signaling Pathways

Objective: This study aims to investigate the active ingredients and potential mechanisms of Total Flavonoids of Hippophae (TFH) in the treatment of Allergic Dermatitis (AD) using network pharmacology and molecular docking. Methods: The effective components and targets of TFH were identified using the TCMSP, Pub- Chem, and Pharmmapper databases. AD-related targets were screened through GeneCards, OMIM, and TTD databases, leading to the identification of TFH anti-AD related targets. The STRING database was utilized to obtain protein interaction relationships, and Cytoscape 3.9.0 software was employed to construct the protein-protein interaction network. GO and KEGG enrichment analyses were conducted to elucidate the biological processes and pathways involved. Molecular docking between key components and key targets was verified using AutoDock Tools 1.5.6 software. Results: The key components identified for anti-AD activity were Quercetin, Kaempferol, Cianidanol, and Epicatechin, while the key targets included MAPK8, MAPK10, MAPK14, AKT1, SRC, and EGFR. GO analysis indicated that TFH's anti-AD effects are primarily associated with hormone regulation, cellular processes, response to stimuli, organelles, and cytoplasm. KEGG enrichment analysis suggested that the key pathways involved are pathways in cancer, lipid and atherosclerosis, and the IL-17 signaling pathway, with a significant emphasis on the IL-17 signaling pathway. Molecular docking results demonstrated that the key active ingredients exhibited strong binding activity with all the key targets, with the highest binding affinities observed between kaempferol and MAPK14, epicatechin and MAPK14, and quercetin and AKT1. Conclusion: TFH exerts therapeutic effects on atopic dermatitis through multi-component, multitarget, and multi-pathway mechanisms involving inflammatory response, immune regulation, and apoptosis. This study provides valuable insights for the further development of drugs specifically targeting AD.

Bioinformatics and network pharmacology discover the molecular mechanism of Liuwei Dihuang pills in treating cerebral palsy.

A collection of chronic central motor, postural, and activity restriction symptoms are referred to as cerebral palsy (CP). Previous research suggests that a number of perinatal variables, including hypoxia, may be linked to CP. And the pathophysiological process that causes brain injury in growing fetuses is mostly caused by amniotic fluid infection and intra-amniotic inflammation. Still, there is still much to learn about the molecular mechanism of CP. The goal of this study was to identify the molecular mechanism of Liuwei Dihuang pill (LWDHP) in the treatment of CP using network pharmacology and bioinformatics. The Chinese medicine database provided the LWDHP components and targets, the CP illness gene data set was gathered from a disease, and the expression profile of children with CP was chosen from anther database. Using the Kyoto Encyclopedia of Genes and Genomes and gene ontology databases, a network of interactions between proteins was created, and functional enrichment analysis was carried out. Analysis of traditional Chinese medicine found that the key active ingredients of LWDHP are quercetin, Stigmasterol and kaempferol. Through enrichment analysis, it was found that the hub genes for LWDHP treatment of CP are CXCL8, MMP9, EGF, PTGS2, SPP1, BCL2L1, MMP1, and AR. K EGG analysis found that LWDHP treatment of CP mainly regulates PI3K-Akt signaling pathway, IL-17 signaling pathway, Jak-STAT signaling pathway, NF-kappa B signaling pathway, etc. To summarize, LWDHP regulates immunological and inflammatory variables through a variety of components, targets, and signaling pathways, which plays a significant role in the development and management of CP.

Cytokine Storm in COVID-19: Exploring IL-6 Signaling and Cytokine-Microbiome Interactions as Emerging Therapeutic Approaches

Cytokine Storm in COVID-19: Exploring IL-6 Signaling and Cytokine-Microbiome Interactions as Emerging Therapeutic Approaches

Berberine-loaded PLGA nanoparticles alleviate ulcerative colitis by targeting IL-6/IL-6R axis

AimsThe present study aims to develop a nano-delivery system that encapsulates berberine (BBR) into PLGA-based nanoparticles (BPL-NPs), to treat ulcerative colitis (UC). Furthermore, the therapeutic efficacy and molecular targeting mechanisms of BPL-NPs in the management of UC are thoroughly examined.MethodsEmulsion solvent-driven methods were used to self-assemble BBR and PLGA into nanoparticles, resulting in the development of the nano-delivery system (BPL-NPs). The therapeutic effectiveness of BPL-NPs was evaluated using a dextran sulfate sodium (DSS)-induced model of ulcerative colitis in mice and a lipopolysaccharide (LPS)-induced model of inflammation in THP-1 macrophages. The interaction between Mφs and NCM-460 cells was investigated using a co-culture system. The molecular targeting ability of BPL-NPs in the treatment of UC was validated through in vitro as well as in vivo experiments.ResultsThe BPL-NPs demonstrated a particle size of 184 ± 22.4 nm, enhanced dispersibility in deionized water, and a notable encapsulation efficiency of 31.1 ± 0.2%. The use of BPL-NPs clearly improved the clinical symptoms and pathological changes associated with UC in mice while also ensuring minimal toxicity. In addition, BPL-NPs improved intestinal epithelial cell apoptosis and enhanced the function of the intestinal barrier by inhibiting M1 Mφs infiltration and IL-6 signaling pathway in mice with UC. Furthermore, the BPL-NPs were found to selectively target the IL-6/IL-6R axis during the M1 Mφs-induced apoptosis of NCM460 cells.ConclusionThe BPL-NPs were confirmed to harbor anti-inflammatory effects both in vitro and in vivo, along with enhanced water solubility and bioactivity. In addition, the precise targeting of the IL-6/IL-6R axis was confirmed as the mechanism by which the BPL-NPs exerted therapeutic effects in UC, as demonstrated in both in vitro as well as in vivo studies.Graphical

Follicle-intrinsic and spatially distinct molecular programs drive follicle rupture and luteinization during ex vivo mammalian ovulation

During ovulation, the apical wall of the preovulatory follicle breaks down to facilitate gamete release. In parallel, the residual follicle wall differentiates into a progesterone-producing corpus luteum. Disruption of ovulation, whether through contraceptive intervention or infertility, has implications for women’s health. In this study, we harness the power of an ex vivo ovulation model and machine-learning guided microdissection to identify differences between the ruptured and unruptured sides of the follicle wall. We demonstrate that the unruptured side exhibits clear markers of luteinization after ovulation while the ruptured side exhibits cell death signals. RNA-sequencing of individual follicle sides reveals 2099 differentially expressed genes (DEGs) between follicle sides without ovulation induction, and 1673 DEGs 12 h after induction of ovulation. Our model validates molecular patterns consistent with known ovulation biology even though this process occurs in the absence of the ovarian stroma, vasculature, and immune cells. We further identify previously unappreciated pathways including amino acid transport and Jag-Notch signaling on the ruptured side and glycolysis, metal ion processing, and IL-11 signaling on the unruptured side of the follicle. This study yields key insights into follicle-inherent, spatially-defined pathways that underlie follicle rupture, which may further understanding of ovulation physiology and advance women’s health.

IL-1β-induced epithelial cell and fibroblast transdifferentiation promotes neutrophil recruitment in chronic rhinosinusitis with nasal polyps

Neutrophilic inflammation contributes to multiple chronic inflammatory airway diseases, including asthma and chronic rhinosinusitis with nasal polyps (CRSwNP), and is associated with an unfavorable prognosis. Here, using single-cell RNA sequencing (scRNA-seq) to profile human nasal mucosa obtained from the inferior turbinates, middle turbinates, and nasal polyps of CRSwNP patients, we identify two IL-1 signaling-induced cell subsets—LY6D+ club cells and IDO1+ fibroblasts—that promote neutrophil recruitment by respectively releasing S100A8/A9 and CXCL1/2/3/5/6/8 into inflammatory regions. IL-1β, a pro-inflammatory cytokine involved in IL-1 signaling, induces the transdifferentiation of LY6D+ club cells and IDO1+ fibroblasts from primary epithelial cells and fibroblasts, respectively. In an LPS-induced neutrophilic CRSwNP mouse model, blocking IL-1β activity with a receptor antagonist significantly reduces the numbers of LY6D+ club cells and IDO1+ fibroblasts and mitigates nasal inflammation. This study implicates the function of two cell subsets in neutrophil recruitment and demonstrates an IL-1-based intervention for mitigating neutrophilic inflammation in CRSwNP.

Elevated Netrin-4 Expression and Its Action in Infrapatellar Fat Pad

Knee osteoarthritis (KOA) is a degenerative joint disease characterized by inflammation and cartilage degradation. The infrapatellar fat pad (IFP), located beneath the patella within the knee joint, serves as a key anatomical structure involved in cushioning and supporting the knee. It is also an active endocrine organ that secretes various bioactive substances, potentially influencing the local inflammatory environment and contributing to KOA pathogenesis. Netrin-4 (NTN4), a protein primarily known for its role in neuronal guidance, has been implicated in various non-neuronal functions, including inflammatory processes and tissue remodeling. This study aims to explore the involvement of NTN4 in KOA, focusing on its expression in the IFP and its potential impact on disease progression. This study involved 82 patients with radiographically confirmed KOA undergoing total knee arthroplasty (TKA). The correlation between NTN4 expression and OA pathology, including Kellgren–Lawrence (K/L) grades, was investigated. NTN4-expressing cells were identified in the stromal vascular fraction, including fibroblastic, hematopoietic, and endothelial cells of the IFP. To elucidate the molecular effects of NTN4, RNA sequencing (RNA-seq) was performed on fibroblastic cells treated with recombinant NTN4. Subsequent quantitative PCR (qPCR) was used to validate the RNA-seq findings. NTN4 expression was significantly elevated in the IFP of patients with advanced KOA (K/L grades 3 and 4) compared to those with early-stage disease (K/L grade 2). Higher NTN4 expression was found in fibroblastic cells, and RNA-seq analysis revealed upregulation of genes associated with pro-inflammatory pathways, including IL-17 and TNF-α signaling, and matrix degradation. Notably, genes including IL6, MMP1, CXCL1, and CXCL8 were significantly elevated, as confirmed by qPCR, indicating NTN4’s role in promoting an inflammatory and catabolic environment. Our findings suggest that NTN4 plays a significant role in the pathogenesis of KOA by promoting inflammation and matrix degradation within the IFP. Although NTN4 expression was not directly correlated with clinical symptoms, its elevated expression in fibroblastic cells and influence on inflammatory and degradative pathways suggest a potential mechanism for exacerbating joint damage. Targeting NTN4 could offer a novel therapeutic approach to mitigating inflammation and slowing disease progression in KOA, ultimately improving patient outcomes. Further research is needed to clarify NTN4’s specific roles and therapeutic potential in OA management.

Ustekinumab affects myofibroblast metabolism to alleviate intestinal fibrosis by targeting KDELC1 in Crohn’s disease through multi-machine learning combined with single-cell sequencing analysis

BackgroundUstekinumab (UST), a biologic against interleukin (IL)-12/23, is commonly used to treat Crohn’s disease (CD). Myofibroblast (MF) is known as one of the most important factors causing intestinal fibrosis, and UST has been reported to alleviate this condition. However, the genetic mechanisms underlying UST’s effects on CD remain unclear. This study uses bioinformatics tools to analyze the genes and potential pathways affected by UST in CD, with a focus on its anti-fibrosis effects, providing insights into new therapeutic targets.MethodsThe data downloaded from the Gene Expression Omnibus (GEO) database were analyzed to screen for differentially expressed genes (DEGs). Various machine learning strategies, including the least absolute shrinkage and selection operator (LASSO), support vector machine (SVM), and random forest (RF), were employed to screen for key genes among the DEGs. Functional and pathway enrichment analyses were conducted, and key genes associated with myofibroblast (MF) activity were screened. Finally, endoscopic surgical specimens from CD patients and healthy participants were collected to assess the expression levels of collagen and key genes in intestinal tissues using hematoxylin–eosin (H&E), Masson staining, and immunohistochemistry.ResultsA total of 1,341 DEGs associated with CD were identified. Among them, 738 genes showed low expression in healthy populations but high expression in patients with CD, reduced expression after the treatment of UST. In contrast, 603 genes exhibited high expression in healthy individuals, showed low expression in CD patients, and increased expression after UST treatment. Functional and pathway analysis showed that DEGs were mainly concentrated in response to foreign biological stimuli and bacterial-derived molecules. DEGs are mainly enriched in chemokines, TNF, IL-17, and other signaling pathways. Seven key genes were identified: NCRNA00236, LOC730101, ORP3, XG, UBFD1, KDELC1, and RBP7. Single-cell analysis revealed that KDELC1 was closely related to MF activity. MFs with high KDELC1 expression were significantly enriched in biological functions, signaling pathways, and metabolic processes that promote fibrosis. The experiment showed that UST treatment helped maintain the integrity of intestinal tissue structure, reducing the expression levels of collagen I, KDELC1, and the severity of intestinal fibrosis. The functional and pathway analysis reiterated that DEGs were largely focused on responses to foreign biological stimuli and bacterial-derived molecules, as well as signaling pathways such as chemokines, TNF, and IL-17. Of the identified genes, KDELC1 showed a particularly strong correlation with MF activity in single-cell analysis (R = 0.33, p = 3.2e-07). MFs with high KDELC1 expression were closely linked to pathways promoting fibrosis progression, including TGF-β, epithelial-mesenchymal transformation, TNF/NF-κB, and related metabolic pathways such as vitamin B6 and arginine.ConclusionKDELC1 plays a key role in regulating multiple biological functions, including signaling pathways related to MF. UST alleviates intestinal fibrosis by targeting KDELC1, thereby influencing intramuscular fat metabolism and intercellular communication.

Deleting fibroblast growth factor 2 in macrophages aggravates septic acute lung injury by increasing M1 polarization and inflammatory cytokine secretion.

Septic lung injury is strongly associated with polarization of M1 macrophages and excessive cytokine release. Fibroblast growth factor (FGF) signaling plays a role in both processes. However, the impact of FGF2 deficiency on macrophage polarization and septic acute lung injury remains unclear. To investigate this, we obtained macrophages from FGF2 knockout mice and examined their polarization and inflammatory cytokine expression. We also eliminated endogenous macrophages using clodronate liposomes and administered FGF2 knockout or WT macrophages intravenously in conjunction with cecal ligation and puncture (CLP) surgery to induce sepsis. In vitro analysis by flow cytometry and real-time PCR analysis demonstrated that FGF2 deficiency resulted in increased expression of M1 markers (iNOS and CD86) and inflammatory cytokines (CXCL1, IL1β, and IL6), especially after LPS stimulation. Additionally, immunofluorescence demonstrated increased nuclear translocation of p65 NF-κB in FGF2 knockout macrophages and RNA-seq analysis showed enrichment of differentially expressed genes in the IL17 and TNFα inflammatory signaling pathways. Furthermore, in vivo experiments revealed that depletion of FGF2 in macrophages worsened sepsis-induced lung inflammation, lung vascular leak, and lung histological injury, accompanied by an increase in CD86-positive cells and apoptosis. Our study suggests that FGF2 deficiency in macrophages plays a critical role in the pathogenesis of septic ALI, possibly because of the enhanced M1 macrophage polarization and production of proinflammatory cytokines. These findings provide empirical evidence for potential therapeutic interventions targeting FGF2 signaling to modulate the polarization of M1 and M2 macrophages in the management of sepsis-induced acute lung injury.

G-CSFR-induced leukocyte transendothelial migration during the inflammatory response is regulated by the ICAM1-PKCa axis: based on multiomics integration analysis

As an indispensable inflammatory mediator during sepsis, granulocyte colony-stimulating factor (G-CSF) facilitates neutrophil production by activating G-CSFR. However, little is known about the role of intracellular downstream signalling pathways in the induction of inflammation. To explore the functions of molecules in regulating G-CSFR signalling, RNA sequencing and integrated proteomic and phosphoproteomic analyses were conducted to predict the differentially expressed molecules in modulating the inflammatory response after G-CSFR expression was either up- or downregulated, in addition to the confirmation of their biological function by diverse experimental methods. In the integrated bioinformatic analysis, 3190 differentially expressed genes (DEGs) and 1559 differentially expressed proteins (DEPs) were identified in multiple-group comparisons (p < 0.05, FC > ± 1.5) using enrichment analyses, as well as those classic pathways such as the TNF, NFkappaB, IL-17, and TLR signalling pathways. Among them, 201 proteins, especillay intercellular cell adhesion molecule-1 (ICAM1) and PKCa, were identified as potential molecules involved in inflammation according to the protein–protein interaction (PPI) analysis, and the leukocyte transendothelial migration (TEM) pathway was attributed to the intervention of G-CSFR. Compared with the control and TNF-a treatment, the G-CSFR (G-CSFROE)-overexpressing led to an obvious increase in the number of leukocytes with the TEM phenotype. Mechanically, the expression of ICAM1 and PKCa was significantly up- and downregulated by G-CSFROE, which directly led to increased TEM; moreover, PKCa expression was negatively regulated by ICAM1 expression, leading to aberrant leukocyte TEM. Altogether, the ICAM1‒PKCa axis was found a meaningful target in the leukocyte TEM induced by G-CSFR upregulation.

Unraveling the Core Components and Critical Targets of Houttuynia cordata Thunb. in Treating Non-small Cell Lung Cancer through Network Pharmacology and Multi-omics Analysis.

This study aimed to preliminary explore the molecular mechanisms of Houttuynia cordata Thunb. (H. cordata; Saururaceae) in treating non-small cell lung cancer (NSCLC), with the goal of screening drug potential targets for clinical drug development. This study employed a multi-omics and multi-source data integration approach to identify potential therapeutic targets of H. cordata against NSCLC from the TCMSP database, GEO database, BioGPS database, Metascape database, and others. Meanwhile, target localization was performed, and its possible mechanisms of action were predicted. Furthermore, dynamics simulations and molecular docking were used for verification. Multiomics analysis was used to confirm the selected key genes' efficacy in treating NSCLC. A total of 31 potential therapeutic targets, 8 key genes, and 5 core components of H. cordata against NSCLC were screened out. These potential therapeutic targets played a therapeutic role mainly by regulating lipid and atherosclerosis, the TNF signaling pathway, the IL-17 signaling pathway, and others. Molecular docking indicated a stable combination between MMP9 and quercetin. Finally, through multi-omics analysis, it was found that the expression of some key genes was closely related not only to the progression and prognosis of NSCLC but also to the level of immune infiltration. Through comprehensive network pharmacology and multi-omics analysis, this study predicts that the core components of H. cordata play a role in treating NSCLC by regulating lipid and atherosclerosis, as well as the TNF signaling pathway. Among them, the anti-NSCLC activity of isoramanone is reported for the first time.

Identification of metabolites from the gut microbiota in hypertension via network pharmacology and molecular docking

Hypertension is the most prevalent cardiovascular disease, affecting one-third of adults. All antihypertensive drugs have potential side effects. Gut metabolites influence hypertension. The objective of this study was to identify antihypertensive gut metabolites through network pharmacology and molecular docking techniques and to validate their antihypertensive mechanisms via in vitro experiments. A total of 10 core antihypertensive targets and 18 gut metabolites that act on hypertension were identified. Four groups of protein metabolites, namely, CXCL8-baicalein, CXCL8-baicalin, CYP1A1-urolithin A, and PTGS2-equol, which have binding energies of − 7.7, − 8.5, − 7.2, and − 8.8 kcal-mol−1, respectively, were found to have relatively high affinities. Based on its drug-likeness properties in silico and toxicological properties, equol was identified as a potential antihypertensive metabolite. On the basis of the results of network pharmacology and molecular docking, equol may exert antihypertensive effects by regulating the IL-17 signaling pathway and PTGS2. A phenylephrine-induced H9c2 cell model was subsequently utilized to verify that equol inhibits cell hypertrophy (P < 0.05) by inhibiting the IL-17 signaling pathway and PTGS2 (P < 0.05). This study demonstrated that equol has the potential to be developed as a novel therapeutic agent for the treatment of hypertension.Graphical

Inflammasome activation links enteric Salmonella Typhimurium infection to a rapid, cytokine-dependent increase in intestinal mucin release

ABSTRACT The host restricts Salmonella enterica serovar Typhimurium infection of the gut via inflammasome-dependent sloughing of infected epithelial cells. Here we determined that concurrent caspase 1/11-dependent release of the goblet cell-derived mucin, Muc2, into the intestinal lumen also controls Salmonella burdens in infected mice. The increased release of mucins from goblet cells in the cecum and nearby proximal colon, and the subsequent thickening of the protective mucus barrier layer in the distal colon, were all dependent on the cytokines interleukin (IL)-18 and IL-22, as deficiencies in either cytokine resulted in reduced mucin secretion. Supplementation of IL-18 into IL-22 deficient mice restored mucin secretion, indicating that IL-22 acted upstream of IL-18 secretion during infection. In contrast, IL-18 and IL-22 independent signaling through Nlrp6 underlies only a modest, infection-induced increase in mucin secretion from goblet cells in the distal colon. These findings reveal that inflammasome signaling orchestrates multiple levels of protection centered on the intestinal epithelium, including pyroptosis and expulsion of infected enterocytes, as well as the release of mucins by goblet cells in the cecum and along the length of the colon. Our studies underscore the pivotal, multi-faceted role of inflammasome signaling in promoting host defense at the intestinal mucosal surface.

TMT-based quantitative proteomics unveils the protective mechanism of Polygonatum sibiricum polysaccharides on septic acute liver injury

Polygonatum sibiricum polysaccharides (PSP) has been shown to possess multiple pharmacological functions. Our previous study found that PSP could protect against acute liver injury during sepsis via inhibiting inflammatory response. However, the underlying molecular mechanism by which PSP alleviates septic acute liver injury (SALI) remains unknown. Herein, TMT-based quantitative proteomics was utilized to explore the essential pathways and proteins involved in the protective effects of PSP on SALI. The results revealed that 632 and 176 differentially expressed proteins (DEPs) were identified in Model_vs_Control and PSP_vs_Model, respectively. GO annotation showed similar trends, suggesting that these DEPs were primarily involved in the cellular anatomical entity in Cellular Component, the cellular processe and the biological regulation in Biological Process, the binding and the catalytic activity in Molecular Function. Meanwhile, KEGG enrichment analysis implied that four common pathways, including the NF-κB signaling pathway, the IL-17 signaling pathway, the TNF signaling pathway and the Toll-like receptor signaling pathway, were closely associated with the pathogenesis of sepsis among the top 20 remarkably enriched pathways in Model_vs_Control_up and PSP_vs_Model_down. Moreover, the levels of several common DEPs, including TLR2, IKKi, JunB and CXCL9, were validated by WB, which was in line with the results of proteomics. Therefore, the protective effects of PSP on SALI might exert via blocking the above-mentioned inflammation pathways.Significance: PSP, recognized as a key component of Polygonatum sibiricum, exhibits a range of pharmacological functions. Our previous study found that PSP could protect against SALI, yet failing to clarify the mechanism of action. To reveal the underlying molecular mechanism involved in the protective effects of PSP on SALI, a TMT-based quantitative proteomic analysis was performed to detect and analyse the DEPs in liver tissue among the control group, the model group and the PSP group in this study. The results provide theoretical references for exploring the action mechanism of drugs and facilitate the comprehensive utilization of PSP. SignificancePSP have been identified as the most crucial components of Polygonatum sibiricum with various pharmacological functions. Our previous study found that PSP could protect against SALI, but the mechanism of action remains unknown. To reveal the underlying molecular mechanism involved in the protective effects of PSP on SALI, a TMT-based quantitative proteomic analysis was performed to detect and analyse the DEPs in liver tissue among the control group, the model group and the PSP group in this study. The results provide theoretical references for exploring the action mechanism of drugs and facilitate the comprehensive utilization of PSP.