The Role of Tumor Necrosis Factor Associated Factors (TRAFs) in Vascular Inflammation and Atherosclerosis

The major roles of intestinal microbiota and TRAF6/NF-κB signaling pathway in acute intestinal inflammation in mice, and the improvement effect by Hippophae rhamnoides polysaccharide

Acute enteritis, an intestinal disease with intestinal inflammation and injury as the main pathological manifestations. Inhibiting the inflammatory response is critical to the treatment of acute enteritis. Previous studies have shown that the Hippophae rhamnoides polysaccharide (HRP) has strong immune-enhancing effects. However, their functions regarding the intestines and the underlying mechanism are still unclear. In this study, the role of HRP in lipopolysaccharide (LPS)-induced acute enteritis in mice and its related mechanisms are discussed from two aspects: intestinal inflammation and intestinal microbiota. Kunming mice were inoculated with LPS to establish animal models of acute enteritis. The results showed that HRP attenuated the histological damage and maintained the intestine mucosal barrier via up-regulating the expression of occludin, claudin-1, and zona occludens-1 (ZO-1), and suppressing the levels of pro-inflammatory cytokines (tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and interleukin-1β (IL-1β)). The relative mRNA and protein levels of nuclear factor-kappa B p65 (NF-κBp65) and tumor necrosis factor-receptor-associated factor 6 (TRAF6) in the intestine tissues of LPS-induced acute enteritis mice significantly increased, whereas these adverse changes were alleviated in the HRP intervention groups. Notably, HRP may regulate the expression of the TRAF6/NF-κB signaling pathway by affecting the diversity of the intestinal microbiota. Microbiota analysis showed that HRP promoted the proliferation of beneficial bacteria, including Clostridia_UCG-014, Candidatus_Saccharimonas, Lachnospiraceae_NK4A136_group, Bacteroidota, Deferribacterota, and reduced the abundance of Atopostipes, Corynebacterium, Actinobacteriota, and Desulfobacterota. The studies conformed that the gut microbiota is crucial in HRP-mediated immunity regulation. HRP shows great potential as an immune enhancer and a natural medicine for treating intestinal inflammatory diseases.

The Role of TNF Receptor-Associated Factor 5 in the Formation of Germinal Centers by B Cells During the Primary Phase of the Immune Response in Mice

TNF receptor-associated factors (TRAFs) function as intracellular adaptor proteins utilized by members of the TNF receptor superfamily, such as CD40. Among the TRAF family proteins, TRAF5 has been identified as a potential regulator of CD40. However, it remains unclear whether TRAF5 regulates the generation of germinal center (GC) B cells and antigen-specific antibody production in the T-dependent (TD) immune response. TRAF5-deficient (Traf5-/-) and TRAF5-sufficient (Traf5+/+) mice were immunized in the footpad with 2,4,6-trinitrophenol-conjugated keyhole limpet hemocyanin (TNP-KLH) and complete Freund's adjuvant (CFA). We found that GC B cell generation and antigen-specific IgM and IgG1 production were significantly impaired in Traf5-/- mice compared to Traf5+/+ mice. The expression levels of CD40-target genes Fas and Lta, which are involved in GC formation, were significantly decreased in B220+ cells isolated from immunized Traf5-/- mice. Traf5-/- B cells showed decreased antibody production, proliferation, and induction of CD40-target genes Tnfaip3, Tnfsf4, and Cd80 in response to agonistic Fc-CD40L protein in vitro. Furthermore, administration of TNP-KLH and Fc-CD40L to Traf5-/- mice resulted in a severe loss of GC B cell development. These results highlight the crucial role of TRAF5 in driving CD40-mediated TD immune response in vivo.

Synergistic Antibacterial Effect of Lactic Acid Bacteria and Baicalin Against Staphylococcus aureus In Vitro and In Vivo

Pathogenic bacteria such as Staphylococcus aureus (S. aureus) are the principal cause of cow mastitis, which primarily impacts milk yield and results in significant financial losses for the animal husbandry industry. Lactic acid bacteria-cell-free supernatant (LAB-CFS) and baicalin (BAI) both have a number of biological effects, including decreasing inflammation. The combined use of LAB-CFS and BAI does not appear to have been used to protective against mastitis, however, and the underlying mechanisms are yet unknown. In this study, in vitro activity of LAB-CFS and BAI alone and in combination was determined (checkerboard experiments, time-kill curves, and flow cytometry to investigate membrane permeability) and examined the protective effects of LAB-CFS and BAI on S. aureus-induced mastitis in mice and the impact of NF-κB signaling pathways on the emergence of mastitis. We discovered that when LAB-CFS and BAI were used together, S. aureus was more effectively treated than when LAB-CFS and BAI were used separately. Flow cytometry demonstrated that LAB-CFS and BAI work together to kill bacteria. In vivo, the usage of LAB-CFS and BAI decreased the activity of myeloperoxidase, as well as IL-6, IL-1β, and TNF-α secretion and the levels of TLR2 and p65 (NF-κB) expression. These findings suggested that LAB-CFS and BAI had a preventive effect against mastitis brought on by S. aureus. Therefore, the NF-κB signaling pathway is thought to be the likely mechanism through which LAB-CFS and BAI reduced S. aureus-induced inflammation in the mammary of cows. For the treatment of cow mastitis, LAB-CFS and BAI are likely to replace antibiotics.

Unveiling the therapeutic potential of miR-146a: Targeting innate inflammation in atherosclerosis

Atherosclerosis is the foremost vascular disease, precipitating debilitating complications. Although therapeutic strategies have historically focused on reducing cholesterol deposition, recent insights emphasize the pivotal role of inflammation. Innate inflammation significantly contributes to plaque instability and rupture, underscoring the need for intervention across all disease stages. Numerous studies have highlighted the therapeutic potential of targeting innate immune pathways in atherosclerosis, revealing significant advancements in understanding the molecular mechanisms underlying inflammatory processes within arterial lesions. Notably, research has demonstrated that the modulation of microRNA-146a (miR-146a) expression impacts innate inflammation, effectively halts atherosclerosis progression, and enhances plaque stability by targeting interleukin-1 receptor-associated kinase (IRAK) and activating TNF receptor-associated factor 6 (TRAF6), a signalling pathway involving toll-like receptors (TLRs). Understanding the intricate mechanisms involved is crucial. This study provides a comprehensive analysis of the evidence and underlying mechanisms through which miR-146a exerts its effects. Integrating these findings into clinical practice may herald a transformative era in managing atherosclerotic cardiovascular disease.

Pan-cancer analysis of the TRAF family genes and their correlation with prognosis, TME, immune and drug sensitivity

BACKGROUND

Tumor necrosis factor receptor-associated factors family genes play a pivotal role in tumorigenesis and metastasis, functioning as adapters or E3 ubiquitin ligases across various signaling pathways. To date, limited research has explored the association between tumor necrosis factor receptor-associated factors family genes and the clinicopathological characteristics of tumors, immunity, and the tumor microenvironment (TME). This comprehensive study investigates the relationship between tumor necrosis factor receptor-associated factors family and prognosis, TME, immune response, and drug sensitivity in a pan-cancer context.

METHODS

Utilizing current public databases, this study examines the expression levels and prognostic significance of tumor necrosis factor receptor-associated factors family genes in a pan-cancer context through bioinformatic analysis. In addition, it investigates the correlation between tumor necrosis factor receptor-associated factors expression and various factors, including the TME, immune subtypes, stemness scores, and drug sensitivity in pan-cancer.

RESULTS

Elevated expression levels of tumor necrosis factor receptor-associated factor 2, 3, 4, and 7 were observed across various cancer types. Patients exhibiting high expression of these genes generally faced a worse prognosis. Furthermore, a significant correlation was noted between the expression of tumor necrosis factor receptor-associated factors family genes and multiple dimensions of the TME, immune subtypes, and drug sensitivity.

Engineering Nanoplatforms for Theranostics of Atherosclerotic Plaques

Atherosclerotic plaque formation is considered the primary pathological mechanism underlying atherosclerotic cardiovascular diseases, leading to severe cardiovascular events such as stroke, acute coronary syndromes, and even sudden cardiac death. Early detection and timely intervention of plaques are challenging due to the lack of typical symptoms in the initial stages. Therefore, precise early detection and intervention play a crucial role in risk stratification of atherosclerotic plaques and achieving favorable post-interventional outcomes. The continuously advancing nanoplatforms have demonstrated numerous advantages including high signal-to-noise ratio, enhanced bioavailability, and specific targeting capabilities for imaging agents and therapeutic drugs, enabling effective visualization and management of atherosclerotic plaques. Motivated by these superior properties, various noninvasive imaging modalities for early recognition of plaques in the preliminary stage of atherosclerosis are comprehensively summarized. Additionally, several therapeutic strategies are proposed to enhance the efficacy of treating atherosclerotic plaques. Finally, existing challenges and promising prospects for accelerating clinical translation of nanoplatform-based molecular imaging and therapy for atherosclerotic plaques are discussed. In conclusion, this review provides an insightful perspective on the diagnosis and therapy of atherosclerotic plaques.

The impact of chronic pain on brain gene expression

Background

Chronic pain affects one fifth of American adults, contributing significant public health burden. Chronic pain mechanisms can be further understood through investigating brain gene expression.

Methods

We tested differentially expressed genes (DEGs) in chronic pain, migraine, lifetime fentanyl and oxymorphone use, and with chronic pain genetic risk in four brain regions (dACC, DLPFC, MeA, BLA) and imputed cell type expression data from 304 postmortem donors. We compared findings across traits and with independent transcriptomics resources, and performed gene-set enrichment.

Results

We identified two chronic pain DEGs: B4GALT and VEGFB in bulk dACC. We found over 2000 (primarily BLA microglia) chronic pain cell type DEGs. Findings were enriched for mouse microglia pain genes, and for hypoxia and immune response. Cross-trait DEG overlap was minimal.

Conclusions

Chronic pain-associated gene expression is heterogeneous across cell type, largely distinct from that in pain-related traits, and shows BLA microglia are a key cell type.

Influence of Race and High Laminar Shear Stress on TNFR1 Signaling in Endothelial Cells

Tumor necrosis factor (TNF) binding to endothelial TNF receptor-I (TNFR-I) facilitates monocyte recruitment and chronic inflammation, leading to the development of atherosclerosis. In vitro data show a heightened inflammatory response and atherogenic potential in endothelial cells (ECs) from African American (AA) donors. High laminar shear stress (HSS) can mitigate some aspects of racial differences in endothelial function at the cellular level. We examined possible racial differences in TNF-induced monocyte adhesion and TNFR1 signaling complex expression/activity, along with the effects of HSS. Tohoku Hospital Pediatrics-1 (THP-1) monocytes were used in a co-culture system with human umbilical vein ECs (HUVECs) from Caucasian American (CA) and AA donors to examine racial differences in monocyte adhesion. An in vitro exercise mimetic model was applied to investigate the potential modulatory effect of HSS. THP-1 adherence to ECs and TNF-induced nuclear factor kappa B (NF-κB) DNA binding were elevated in AA ECs compared to CA ECs, but not significantly. We report no significant racial differences in the expression of the TNFR-I signaling complex. Application of HSS significantly increased the expression and shedding of TNFR-I and the expression of TRAF3, and decreased the expression of TRAF5 in both groups. Our data does not support TNF-induced NF-κB activation as a potential mediator of racial disparity in this model. Other pathways and associated factors activated by the TNFR1 signaling complex are recommended targets for future research.

The indispensability of macrophage adaptor proteins in chronic inflammatory diseases

Adaptor proteins represent key signalling molecules involved in regulating immune responses. The host's innate immune system recognizes pathogens via various surface and intracellular receptors. Adaptor molecules are centrally involved in different receptor-mediated signalling pathways, acting as bridges between the receptors and other molecules. The presence of adaptors in major signalling pathways involved in the pathogenesis of various chronic inflammatory diseases has drawn attention toward the role of these proteins in such diseases. In this review, we summarize the importance and roles of different adaptor molecules in macrophage-mediated signalling in various chronic disease states. We highlight the mechanistic roles of adaptors and how they are involved in protein-protein interactions (PPI) via different domains to carry out signalling. Hence, we also provide insights into how targeting these adaptor proteins can be a good therapeutic strategy against various chronic inflammatory diseases.

Uncovering the Genetic Link between Acute Myocardial Infarction and Ulcerative Colitis Co-Morbidity through a Systems Biology Approach

Background: Cardiovascular diseases, particularly acute myocardial infarction, are the leading cause of disability and death. Atherosclerosis, the pathological basis of AMI, can be accelerated by chronic inflammation. Ulcerative colitis (UC), a chronic inflammatory disease associated with immunity, contributes to the risk of AMI development. However, controversy continues to surround the relationship between these two diseases. The present study unravels the pathogenesis of AMI and UC, to provide a new perspective on the clinical management of patients with these comorbidities.

Methods: Microarray datasets GSE66360 and GSE87473 were downloaded from the Gene Expression Omnibus database. Common differentially expressed genes (co-DEGs) between AMI and UC were identified, and the following analyses were performed: enrichment analysis, protein-protein interaction network construction, hub gene identification and co-expression analysis.

Results: A total of 267 co-DEGs (233 upregulated and 34 downregulated) were screened for further analysis. GO enrichment analysis suggested important roles of chemokines and cytokines in AMI and UC. In addition, the lipopolysaccharide-mediated signaling pathway was found to be closely associated with both diseases. KEGG enrichment analysis revealed that lipid and atherosclerosis, NF-κB, TNF and IL-17 signaling pathways are the core mechanisms involved in the progression of both diseases. Finally, 11 hub genes were identified with cytoHubba: TNF, IL1B, TLR2, CXCL8, STAT3, MMP9, ITGAX, CCL4, CSF1R, ICAM1 and CXCL1.

Conclusion: This study reveals a co-pathogenesis mechanism of AMI and UC regulated by specific hub genes, thus providing ideas for further mechanistic studies, and new perspectives on the clinical management of patients with these comorbidities.

Role of CD40(L)-TRAF signaling in inflammation and resolution-a double-edged sword

Cardiovascular diseases (CVD) and cardiovascular risk factors are the leading cause of death in the world today. According to the Global Burden of Disease Study, hypertension together with ischemic heart and cerebrovascular diseases is responsible for approximately 40% of all deaths worldwide. The major pathomechanism underlying almost all CVD is atherosclerosis, an inflammatory disorder of the vascular system. Recent large-scale clinical trials demonstrated that inflammation itself is an independent cardiovascular risk factor. Specific anti-inflammatory therapy could decrease cardiovascular mortality in patients with atherosclerosis (increased markers of inflammation). Inflammation, however, can also be beneficial by conferring so-called resolution, a process that contributes to clearing damaged tissue from cell debris upon cell death and thereby represents an essential step for recovery from, e.g., ischemia/reperfusion damage. Based on these considerations, the present review highlights features of the detrimental inflammatory reactions as well as of the beneficial process of immune cell-triggered resolution. In this context, we discuss the polarization of macrophages to either M1 or M2 phenotype and critically assess the role of the CD40L-CD40-TRAF signaling cascade in atherosclerosis and its potential link to resolution. As CD40L can bind to different cellular receptors, it can initiate a broad range of inflammatory processes that may be detrimental or beneficial. Likewise, the signaling of CD40L downstream of CD40 is mainly determined by activation of TRAF1-6 pathways that again can be detrimental or beneficial. Accordingly, CD40(L)-based therapies may be Janus-faced and require sophisticated fine-tuning in order to promote cardioprotection.

Toll-Like Receptor 9 Signaling Pathway Contributes to Intestinal Mucosal Barrier Injury in Mice With Severe Acute Pancreatitis

OBJECTIVES

The purpose of this study was to investigate the role and mechanism of toll-like receptor 9 (TLR9) in intestinal mucosal barrier injury in mice with severe acute pancreatitis (SAP).

METHODS

The mice were randomly divided into 3 groups: control group, SAP group, and TLR9 antagonist-treated group. The expression of tumor necrosis factor-α, interleukin-1β, interleukin-6, diamine oxidase, and endotoxin core antibodies were detected by enzyme-linked immunosorbent assay. The protein expression of zonula occluden-1 (ZO)-1, occludin, TLR9, myeloid differentiation factor 88 (MyD88), tumor necrosis factor receptor-associated factor 6 (TRAF6), p-nuclear factor (NF)-κB p65, and NF-κB p65 were detected by Western blot. TdT-mediated dUTP nick-end labeling staining was used for detecting intestinal epithelial cell apoptosis.

RESULTS

The expression of TLR9 and its related pathway proteins MyD88, TRAF6, and p-NF-κB p65 in the intestinal tract of SAP mice were significantly increased compared with that of control mice. Inhibition of the TLR9 expression could reduce the level of serum proinflammatory cytokines, reduce the apoptosis of intestinal epithelial cells, improve intestinal permeability, and ultimately reduce the damage of intestinal mucosal barrier function in SAP.

CONCLUSIONS

Toll-like receptor 9/MyD88/TRAF6/NF-κB signaling pathway plays an important role in intestinal mucosal barrier injury of SAP.

Curcumenol Mitigates the Inflammation and Ameliorates the Catabolism Status of the Intervertebral Discs In Vivo and In Vitro via Inhibiting the TNFα/NFκB Pathway

Low back pain (LBP) caused by intervertebral disc degeneration (IVDD) is accredited to the release of inflammatory cytokines followed by biomechanical and structural deterioration. In our study, we used a plant-derived medicine, curcumenol, to treat IVDD. A cell viability test was carried out to evaluate the possibility of using curcumenol. RNA-seq was used to determine relative pathways involved with curcumenol addition. Using TNFα as a trigger of inflammation, the activation of the NF-κB signaling pathway and expression of the MMP family were determined by qPCR and western blotting. Nucleus pulposus (NP) cells and the rats’ primary NP cells were cultured. The catabolism status was evaluated by an ex vivo model. A lumbar instability mouse model was carried out to show the effects of curcumenol in vivo. In general, RNA-seq revealed that multiple signaling pathways changed with curcumenol addition, especially the TNFα/NF-κB pathway. So, the NP cells and primary NP cells were induced to suffer inflammation with the activated TNFα/NF-κB signaling pathway and increased expression of the MMP family, such as MMP3, MMP9, and MMP13, which would be mitigated by curcumenol. Owing to the protective effects of curcumenol, the height loss and osteophyte formation of the disc could be prevented in the lumbar instability mouse model in vivo.