Semaphorin 7A interacts with nuclear factor NF-kappa-B p105 via integrin β1 and mediates inflammation

Indole-3-carbinol inhibits PD-L1-mediated immune evasion in hepatocellular carcinoma via suppressing NF-κB p105 Ubiquitination

BACKGROUND

Hepatocellular carcinoma (HCC) is one of the most common malignant tumors worldwide, and immunotherapy has demonstrated significant therapeutic benefit in HCC. Indole-3-carbinol (I3C), a naturally occurring ingredient of cruciferous vegetables, significantly inhibits the growth of a wide range of tumors. However, its mechanism of action has not been fully elucidated.

PURPOSE

This study aims to verify and explore the immunomodulatory effect of I3C in HCC models, and to investigate the specific role and mechanism by which I3C affects PD-L1 expression through the ubiquitination of NF-κB p105.

METHODS

In vitro, I3C was treated with HepG2 cells and relevant indicators were analyzed. In vivo, the mouse HCC model was established and the effect of I3C on tumors and immune function was evaluated. Subsequently, the downstream target of I3C was found through target prediction, molecular docking, and molecular dynamics simulation. Finally, combined therapy was used to further investigate the effect of I3C on mouse HCC tumors.

RESULTS

We observed that I3C resulted in decreased programmed cell death ligand 1 (PD-L1) expression in HepG2 cells and increased CD8 T cell infiltration in tissues. Subsequently, target prediction and molecular docking demonstrated that I3C was able to efficiently bind to NF-κB p105. In addition, overexpression of NF-κB p105 upregulated PD-L1 expression and almost completely eliminated the inhibitory effect of I3C. Notably, the combination of I3C and PD-L1 monoclonal antibodies showed synergistic anti-tumor effects in the mouse HCC model.

CONCLUSION

This study demonstrated that I3C inhibits PD-L1-mediated immune evasion in HCC via suppressing NF-κB p105 ubiquitination. The role of I3C in tumors deserves further investigation and provides the foundation for the future development of novel immunotherapeutic drugs.

The characterization and validation of regulated cell death-related genes in chronic rhinosinusitis with nasal polyps

BACKGROUND

Regulated cell death (RCD), a genetically controlled process mediated by specialized molecular pathways (commonly termed programmed cell death), plays pivotal roles in diverse pathophysiological processes. However, the landscape and functional implications of RCD subtypes in chronic rhinosinusitis with nasal polyps (CRSwNP) remain poorly characterized. This study aimed to systematically investigate the involvement of RCD mechanisms in the pathogenesis and progression of CRSwNP.

METHODS

Transcriptomic datasets (GSE136825, GSE23552, GSE198950, GSE196169, GSE156285) related to CRSwNP were retrieved from the Gene Expression Omnibus (GEO) database. A comprehensive panel of 18 RCD-associated gene sets was compiled through a systematic literature review. Gene set variation analysis (GSVA) was employed to profile RCD activation patterns in CRSwNP. Integrative bioinformatics approaches including weighted gene co-expression network analysis (WGCNA) and least absolute shrinkage and selection operator (LASSO) regression were implemented to identify hub RCD-related genes and construct a cell death index (CDI). Single-cell RNA sequencing (scRNA-seq) data were analyzed to map RCD dynamics across cellular subpopulations. Clinical validation was performed using qRT-PCR quantification of key genes in nasal polyp/inferior turbinate tissues, with the concurrent assessment of symptom severity via visual analogue scale (VAS) scores.

RESULTS

GSVA revealed significant upregulation of 8 RCD subtypes in CRSwNP: apoptosis, ferroptosis, necroptosis, entotic cell death, lysosome-dependent cell death, NETosis, immunogenic cell death, and anoikis. Pathway enrichment analysis demonstrated that RCD-related differentially expressed genes were predominantly involved in epithelial-mesenchymal transition (EMT) and immune-inflammatory regulation. Furthermore, the WGCNA algorithm and LASSO analysis identified 8 key cell death genes (PTHLH, GRINA, S100A9, SCG2, HMOX1, RNF183, TYROBP, SEMA7A), which were utilized to construct the cell death-related index (CDI). In training and validation cohorts, the CDI was significantly elevated in CRSwNP compared to control and exhibited high diagnostic performance, with elevated scores correlating with enhanced immune cell infiltration. Single-cell resolution analysis uncovered cell type-specific RCD activation patterns. Clinical validation confirmed significantly higher expression of S100A9, PTHLH, and HMOX1 in eosinophilic versus non-eosinophilic polyps. Notably, expression levels of PTHLH, S100A9, HMOX1, GRINA, and TYROBP showed strong positive correlations with VAS scores.

CONCLUSIONS

Our investigation delineates an RCD activation signature in CRSwNP pathogenesis, characterized by 8 key cell death modalities and their regulatory genes. The novel CDI exhibits promising diagnostic potential, while mechanistic insights suggest RCD pathways may drive disease progression through EMT potentiation and inflammatory cascade amplification. These findings provide a framework for developing RCD-targeted therapeutic strategies in CRSwNP.

Genetic predisposition to Behcet's disease mediated by a IL10RA enhancer polymorphism

Background

Several studies suggested the genetic association between IL10RA variants and susceptibility to Behcet's disease (BD). However, the precise mechanism of the association is still unknown. The purpose of this study was to investigate the mechanism underlying the genetic associations between IL10RA polymorphisms and the risk of BD.

Methods

To analyse the genetic susceptibility to BD mediated by IL10RA causal polymorphisms, we performed a study on data from our previous genome-wide association studies (GWAS), the bioinformatic analysis of post-annotation of GWAS and relevant mechanism verification experiments, including chromatin immunoprecipitation, luciferase gene-reporter assay, electrophoretic mobility shift assays, and enzyme-linked immunosorbent assay.

Results

Among 125 single nucleotide polymorphisms (SNPs) with P < 1 × 10-5 identified in our previous GWAS study on BD, rs4936415 (G/C) was predicted with the highest conserved score as an expression quantitative-trait-locus SNP for IL10RA in whole blood. There were H3K27ac and H3K4Me1 enhancer-specific enrichments around SNP rs4936415. Luciferase gene-reporter assays revealed that the rs4936415 G-allele construct showed a higher enhancer activity as compared to the empty and the C-allele construct. NF-κB1 was identified to bind the C-allele rather than the G-allele, although the enhancer SNP (rs4936415) region was found to control transcription factor binding sites. Interaction of C-allele and NF-κB1 gene construct resulted in an increased enhancer activity. BD patients showed a significantly lower serum level of the IL-10Rα.

Conclusions

This study identified a single functional causal SNP, rs4936415, in the IL10RA super-enhancer, conferring BD susceptibility. The protective G-allele of non-coding rs4936415 located inside an enhancer region of IL10RA promoted the enhancer activity and increased the expression of IL10RA.The risk C-allele is able to specifically bind NF-κB1 and, in turn, promotes enhancer activity of IL10RA. This subsequently leads to an increased expression of IL10RA. Low expression of IL-10RA suggests a relative deficiency of NF-κB1 in BD.

The calcium-sensing receptor alleviates endothelial inflammation in atherosclerosis through regulation of integrin β1-NLRP3 inflammasome

Atherosclerosis (AS) is a chronic inflammatory disease of arteries. Endothelial inflammation is key to the initiation and development of AS. The calcium-sensing receptor (CaSR) is expressed in endothelial cells (ECs) but its role in endothelial inflammation during AS remains unclear. This study focused on the involvement of CaSR in regulating endothelial inflammation and its underlying mechanisms, providing novel insights for AS therapy. Here, we observed that CaSR agonist NPS-R568 significantly reduced atherosclerotic lesions and aortic inflammation in high-fat diet (HFD)-fed ApoE-/- mice, while enhancing the expression of CaSR in aortic tissues. In vitro, human umbilical vein endothelial cells (HUVECs) exposed to oxidized low-density lipoprotein (oxLDL) at 20 μg·mL-1 triggered inflammation, as indicated by the upregulation of vascular cell adhesion molecule-1 (VCAM-1), interleukin (IL)-6, and IL-1β expression, along with increased adherence of THP-1 or U937 cells to the HUVECs. Additionally, treatment with 20 μg·mL-1 oxLDL led to downregulation of CaSR expression in HUVECs. The administration of CaSR agonist NPS-R568 or overexpression of CaSR in HUVECs resulted in a significant reversal of inflammation induced by oxLDL. Mechanistically, CaSR was found to mitigate NLRP3 inflammasome activation by downregulating the protein level of integrin β1. In conclusion, our study elucidates the beneficial role of CaSR in reducing endothelial inflammation in AS through the regulation of integrin β1 and the subsequent NLRP3 inflammasome. CaSR emerges as a promising target for potential therapeutic interventions in AS.

Semaphorin3C identified as mediator of neuroinflammation and microglia polarization after spinal cord injury

Excessive neuroinflammation after spinal cord injury (SCI) is a major hurdle during nerve repair. Although proinflammatory macrophage/microglia-mediated neuroinflammation plays important roles, the underlying mechanism that triggers neuroinflammation and aggravating factors remain unclear. The present study identified a proinflammatory role of semaphorin3C (SEMA3C) in immunoregulation after SCI. SEMA3C expression level peaked 7 days post-injury (dpi) and decreased by 14 dpi. In vivo and in vitro studies revealed that macrophages/microglia expressed SEMA3C in the local microenvironment, which induced neuroinflammation and conversion of proinflammatory macrophage/microglia. Mechanistic experiments revealed that RAGE/NF-κB was downstream target of SEMA3C. Inhibiting SEMA3C-mediated RAGE signaling considerably suppressed proinflammatory cytokine production, reversed polarization of macrophages/microglia shortly after SCI. In addition, inhibition of SEMA3C-mediated RAGE signaling suggested that the SEMA3C/RAGE axis is a feasible target to preserve axons from neuroinflammation. Taken together, our study provides the first experimental evidence of an immunoregulatory role for SEMA3C in SCI via an autocrine mechanism.

The Role of Semaphorins in the Pathogenesis of Rheumatoid Arthritis

Rheumatoid arthritis (RA) is one of the most common autoimmune diseases. Inflammation of the synovial fluid propagates the pathological process of angiogenesis. Semaphorins play a crucial role in the context of endothelial cell function, and their pleiotropic nature has various effects on the further development of RA. This narrative review summarises the various roles of semaphorins in the pathology of RA and whether they could play a role in developing novel RA treatment options.

Dynamic regulation of semaphorin 7A and adhesion receptors in ovarian follicle remodeling and ovulation

The ovarian follicle is a complex structure that protects and helps in the maturation of the oocyte, and then releases it through the controlled molecular and structural remodeling process of ovulation. The progesterone receptor (PGR) has been shown to be essential in regulating ovulation-related gene expression changes. In this study, we found disrupted expression of the cellular adhesion receptor gene Sema7A in the granulosa cells of PGR-/- mice during ovulation. We subsequently found that expression of Sema7A in preovulatory follicles is promoted by gonadotropins and hypoxia, establishing an asymmetrical pattern with the SEMA7A protein enriched at the apex of large antral follicles. Sema7A expression was downregulated through a PGR-dependent mechanism in the periovulatory period, the abundance of SEMA7A protein was reduced, and the asymmetric pattern became more homogeneous after an ovulatory stimulus. Receptors for Sema7A can either repel or promote intercellular adhesion. During ovulation, striking inverse regulation of repulsive Plxnc1 and adhesive Itga5/Itgb1 receptors likely contributes to dramatic tissue remodeling. The adhesive receptor Itga5 was significantly increased in periovulatory granulosa cells and cumulus-oocyte complexes (COCs), and functional assays showed that periovulatory granulosa cells and COCs acquire increased adhesive phenotypes, while Sema7A repels granulosa cell contact. These findings suggest that the regulation of Sema7A and its associated receptors, along with the modulation of integrin α5, may be critical in establishing the multilaminar ovarian follicle structure and facilitating the remodeling and apical release of the cumulus-oocyte complex during ovulation.