Loss of Gαq impairs regulatory B-cell function

5-HT induces regulatory B cells in fighting against inflammation-driven ulcerative colitis

Serotonin (5-hydroxytryptamine or 5-HT) is a neuroendocrine peptide endowed with immunomodulatory functions. Regulatory B cells (Bregs) play an important role in maintaining intestinal immune homeostasis. We analyzed the differences of 5-HT and Bregs between peripheral blood of ulcerative colitis (UC) and healthy controls (HC). Besides, 5-HT-treated B cells were adoptively transferred into colitis mice to elucidate the role of 5-HT in regulating Bregs. The level of serum 5-HT and IL-10 in UC patients was lower and both were negatively correlated with disease activity. 5-HT7 receptor (5-HT7R) was higher expressed on Bregs in UC. 5-HT promoted IL-10 production in Bregs through the activation of STAT3. And adoptive transfer of 5-HT-treated B cells alleviated intestinal inflammation via inducing IL-10-producing B cells in mice. Our results suggest that 5-HT/5-HT7R signaling pathway facilitate functional Bregs in constraining inflammation in UC, which may be a new potential prospect in the treatment of UC.

Crosstalk between TRPV1 and immune regulation in Fuchs endothelial corneal dystrophy

Fuchs endothelial corneal dystrophy (FECD) is the leading indication for corneal transplantation worldwide. Our aim was to investigate the role of transient receptor potential vanilloid subtype 1 (TRPV1) and the associated immune regulation contributing to this pathological condition. Significant upregulation of TRPV1 was detected in the H2O2-induced in vitro FECD model. Based on gene expression microarray dataset GSE142538 and in vitro results, a comprehensive immune landscape was studied and a negative correlation was found between TRPV1 with different immune cells, especially regulatory T cells (Tregs). Functional analyses of the 313 TRPV1-related differentially expressed genes (DEGs) revealed the involvement of TRP-regulated calcium transport, as well as inflammatory and immune pathways. Four TRPV1-related core genes (MAPK14, GNB1, GNAQ, and ARRB2) were screened, validated by microarray dataset GSE112039 and the combined validation dataset E-GEAD-399 & 564, and verified by in vitro experiments. Our study suggested a potential crosstalk between TRPV1 and immune regulation contributing to FECD pathogenesis. The identified pivotal biomarkers and immune-related pathways provide a novel framework for future mechanistic and therapeutic studies of FECD.

G Protein-Coupled receptors and heterotrimeric G proteins as cancer drivers

G protein-coupled receptors (GPCRs) and heterotrimeric G proteins play central roles in a diverse array of cellular processes. As such, dysregulation of GPCRs and their coupled heterotrimeric G proteins can dramatically alter the signalling landscape and functional state of a cell. Consistent with their fundamental physiological functions, GPCRs and their effector heterotrimeric G proteins are implicated in some of the most prevalent human diseases, including a complex disease such as cancer that causes significant morbidity and mortality worldwide. GPCR/G protein-mediated signalling impacts oncogenesis at multiple levels by regulating tumour angiogenesis, immune evasion, metastasis, and drug resistance. Here, we summarize the growing body of research on GPCRs and their effector heterotrimeric G proteins as drivers of cancer initiation and progression, and as emerging antitumoural therapeutic targets.

Glycosides of Caulis Lonicerae inhibits the inflammatory proliferation of IL-1β-mediated fibroblast-like synovial cells cocultured with lymphocytes

Caulis Lonicerae, the dried stem of Lonicera japonica, has been confirmed to have antiinflammatory and antioxidant therapeutic effects. In the present study, we aimed to evaluate the functional mechanism of glycosides extracted from Caulis Lonicerae on the inflammatory proliferation of interleukin-1 beta (IL-1β)-mediated fibroblast-like synoviocytes (FLSs) from rats. Rat FLSs (RSC-364) co-cultured with lymphocytes induced by IL-1β were used as a cell model. Glycosides in a freeze-dried powder of aqueous extract from Caulis Lonicerae were identified using high-performance liquid chromatography-electrospray ionization/mass spectrometry. After treatment with glycosides, the inflammatory proliferation of FLS, induced by IL-1β, decreased significantly. Flow cytometry analysis showed that treatment with glycosides restored the abnormal balance of T cells by intervening in the proliferation and differentiation of helper T (Th) cells. Glycosides also inhibited the activation of Janus kinase signal transducer and activator of transcription (JAK-STAT) and nuclear factor (NF)-κB signaling pathways by suppressing the protein expression of key molecules in these pathways. Therefore, we concluded that the glycosides of Caulis Lonicerae can intervene in the differentiation of Th cells, suppressing the activation of JAK-STAT and NF-κB signaling pathways, contributing to the inhibitory effect on inflammatory proliferation of FLS co-cultured with lymphocytes induced by pro-inflammatory cytokines.

T-cells interact with B cells, dendritic cells, and fibroblast-like synoviocytes as hub-like key cells in rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic inflammatory synovitis-based systemic disease characterized by invasive joint inflammation and synovial hyperplasia, which can lead to arthrentasis and defunctionalization. Previous research has shown that T cells, B cells, dendritic cells (DCs), and fibroblast-like synoviocytes (FLSs) play vital roles in the regulation of RA. Both T follicular helper (Tfh) cells and helper T (Th) 17 cells play immunomodulatory roles in RA. Moreover, interleukin-23 (IL-23), and IL-17 are vital to the pathogenesis of RA. T cells behave as a hub, in that B cells, DCs, and FLSs can interact with T cells to inhibit their activation and interfere with the process of RA. T cells cooperate with B cells, DCs, and FLSs to maintain the stability of the immune system under physiological conditions. However, under pathological conditions, the balance is disrupted, and the interaction of T cells with other cells may intensify disease progression. This review focuses on the interaction of T cells with B cells, DCs, and FLSs in different tissues and organs of RA patients and animal models, and highlight that the interplay between immune cells may underline the unique function of T cells and the application prospect of targeting T cell treatment for RA.