Deficiency of the G protein Gαq ameliorates experimental autoimmune encephalomyelitis with impaired DC-derived IL-6 production and Th17 differentiation

Many G protein-coupled receptors （GPCRs） are reported to be involved in the pathogenesis of multiple sclerosis （MS）, and -40% of all identified GPCRs rely on the Gaq/11 G protein family to stimulate inositol lipid signaling. However, the function of Ga subunits in MS pathogenesis is still unknown. In this study, we attempted to determine the role of Gaq in the pathogenesis of experimental autoimmune encephalomyelitis （EAE）, a well-known mouse model of MS. We discovered that compared with wild-type mice, Gaq-knockout mice exhibited less severe EAE symptoms, with lower clinical scores, reduced leukocyte infiltration and less extensive demyelination. Moreover, a significantly lower percentage of Th17 cells, one of the key players in MS pathogenesis, was observed in Gaq-knockout EAE mice. Studies in vitro demonstrated that deficiency of Gaq in CD4＋ T cells directly impaired Th17 differentiation. In addition, deficiency of Gaq significantly impaired DC-derived IL-6 production, thus inhibiting Th17 differentiation and the Gaq-PLCβ-PKC and Gaq-MAPKs signaling pathways involved in the reduced IL-6 production by DCs. In summary, our data highlighted the critical role of Gaq in regulating Th17 differentiation and MS oathogenesis.

Macrocyclic Nonapeptides Incorporating Uncharacterized Amino Acids with Inhibitory Effects on Th17 Differentiation

Four unprecedented macrocyclic nonapeptides,orberryamides A–D(1–4),were isolated from Glycosmis pentaphylla(orangeberry)and structurally characterized by obtaining solid data from numerous analytical measurements.Compound 1 incorporated a new amino acid residue,named orangeberrine(Orgb),compounds 2 and 3 integrated the rare,nonproteinogenic amino acid residues(Kyn and Dioia,respectively),and compound 4 existed as two major conformational isomers in solution at ambient temperature.The biosynthetic pathways proposed for compounds 1–4 are of considerable biological significance for the modification and metabolism of tryptophan(Trp)and/or Trp containing proteins in nature.Besides,compounds 1–4 suppressed Th17 differentiation significantly,and the effects of 1–3 was achieved through targeting the ligand-binding domain(LBD)of the retinoic acid-related orphan receptor gamma t(RORγt).

Rheum palmatum L. and Salvia miltiorrhiza Bge. Alleviates Acute Pancreatitis by Regulating Th17 Cell Differentiation: An Integrated Network Pharmacology Analysis, Molecular Dynamics Simulation and Experimental Validation

Objective: To identify the core targets of Rheum palmatum L. and Salvia miltiorrhiza Bge.,(Dahuang-Danshen, DH-DS) and the mechanism underlying its therapeutic efficacy in acute pancreatitis(AP)using a network pharmacology approach and validate the findings in animal experiments. Methods: Network pharmacology analysis was used to elucidate the mechanisms underlying the therapeutic effects of DH-DS in AP. The reliability of the results was verified by molecular docking simulation and molecular dynamics simulation.Finally, the results of network pharmacology enrichment analysis were verified by immunohistochemistry,Western blot analysis and real-time quantitative PCR, respectively. Results: Sixty-seven common targets of DH-DS in AP were identified and mitogen-activated protein kinase 3(MAPK3), Janus kinase 2(JAK2), signal transducer and activator of transcription 3(STAT3), protein c-Fos(FOS) were identified as core targets in the protein interaction(PPI) network analysis. Gene ontology analysis showed that cellular response to organic substance was the main functions of DH-DS in AP, and Kyoto Encyclopedia of Genes and Genomes analysis showed that the main pathway included Th17 cell differentiation. Molecular docking simulation confirmed that DH-DS binds with strong affinity to MAPK3, STAT3 and FOS. Molecular dynamics simulation revealed that FOS-isotanshinone Ⅱ and STAT3-dan-shexinkum d had good binding capacity. Animal experiments indicated that compared with the AP model group, DH-DS treatment effectively alleviated AP by inhibiting the expression of interleukin-1β, interleukin-6 and tumor necrosis factor-α, and blocking the activation of Th17 cell differentiation(P<0.01). Conclusion: DH-DS could inhibit the expression of inflammatory factors and protect pancreatic tissues,which would be functioned by regulating Th17 cell differentiation-related m RNA and protein expressions.