BACKGROUND AND PURPOSEChronic exposure to morphine increases spinal adrenomedullin (AM) bioactivity resulting in the development and maintenance of morphine tolerance. This study investigated the possible involvement of AM in morphine-evoked alteration in μ-opioid receptor-coupled G proteins. EXPERIMENTAL APPROACHAgents were administered intrathecally (i.t.) in rats. Nociceptive behaviours and cumulative dose-response of morphine analgesia were assessed. Neurochemicals in the spinal dorsal horn were assayed by immunoprecipitation, Western blot analysis and ELISA. KEY RESULTSIntrathecal injection of AM (8 μg) for 9 days decreased and increased the levels of μ receptor-coupled Gi and Gs proteins respectively. Morphine stimulation (5 μg) after chronic treatment with AM also induced an increase in cAMP production in the spinal dorsal horn. Co-administration of the selective AM receptor antagonist AM 22-52 inhibited chronic morphine-evoked switch of G protein-coupled μ receptor from Gi to Gs. Chronic exposure to AM increased the phosphorylation of cAMP-responsive element-binding protein (CREB) and ERK. Co-administration of the PKA inhibitor H-89 (5 μg) or MEK1 inhibitor PD98059 (1 μg) reversed the AM-induced thermal/mechanical hypersensitivity, decline in morphine analgesic potency, switch of G proteincoupled μ receptor and increase in cAMP. CONCLUSIONS AND IMPLICATIONSThe present study supports the hypothesis that an increase in AM activity in the spinal dorsal horn contributes to the switch of the μ receptor-coupled G protein from Gi to Gs protein via the activation of cAMP/PKA/CREB and ERK signalling pathways in chronic morphine use. AbbreviationsAM, adrenomedullin; IPP, immunoprecipitation; MPE, maximum possible efffect; MEK, MAP kinase kinase; TFL, tail flick latency; TRPV1, Transient receptor potential vanilloid 1

Acute liver failure (ALF) is a serious life-threatening condition. Mesenchymal stem cells (MSCs) may be an effective treatment for this condition and a good alternative to liver transplantation. Icaritin (ICT) is an active ingredient of the genus Epimedium, a traditional Chinese medicine, with the potential to enhance the proliferation of MSCs. The purpose of this study was to explore whether ICT increased the therapeutic effects of MSCs and explore its underlying mechanisms. For in vivo experiments, a rat ALF model was established by intraperitoneal injection of D(+)-galactosamine/ lipopolysaccharide. MSCs cocultured with ICT were used to treat ALF rats and the protective effects assessed as survival rate, levels of serum AST and ALT, and histological changes in liver tissue. For in vitro experiments, MSCs were treated in serum-free culture for 72 h to simulate the disruption of intrahepatic microcirculation. MSCs apoptosis was examined to determine whether ICT rescued impaired MSCs. The role of the hepatocyte growth factor (HGF)/c-Met pathway in MSCs was assessed by constructing genetically modified MSCs overexpressing c-Met and by using the c-Met receptor inhibitor (crizotinib). The results showed that MSCs increased the survival rate of ALF rats and reduced liver damage. MSCs cocultured with ICT exerted a greater therapeutic effect than MSCs alone. Further, the HGF/c-Met pathway played a key role in the antiapoptotic activity of MSCs, which was associated with the optimized efficacy of ICT. In conclusion, this study demonstrated that ICT enhances the therapeutic effect of MSCs in a model of ALF, improving the antiapoptotic potential of MSCs by upregulation of the HGF/c-Met pathway. The combination of stem cell therapy with traditional herbal extracts may improve MSC-based clinical applications.

Background Accumulating evidence suggested a strong association between polycystic ovary syndrome (PCOS) and ovarian cancer (OC), but the potential molecular mechanism is still unclear. In this study, we identify unrecognized but significant genes correlated to PCOS and OC via bioinformatics. Materials and methods Multiple bioinformatic analysis, such as Differential expression analysis, Univariate Cox analysis, functional and pathway enrichment analysis, protein–protein interaction (PPI) network construction, survival analysis, and Immune infiltration analysis were utilized. We further evaluated the effect of OGN on FSHR expression via immunofluorescence. Results The TCGA-OC dataset, GSE140082 (for OC) and GSE34526 (for PCOS) dataset were downloaded. 12 genes, RNF144B, LPAR3, CRISPLD2, JCHAIN, OR7E14P, IL27RA, PTPRD, STAT1, NR4A1, OGN, GALNT6 and CXCL11, were recognized as signature genes. Drug sensitive analysis was showed that OGN might be a hub gene in the progression of PCOS and OC. Experimental analysis found OGN could increase the FSHR expression, indicating OGN could regulate the hormonal response in PCOS and OC. Furthermore, correlation analysis indicated that the function of OGN might be closely related with m6A and ferroptosis. Conclusions Our study indicated 12 signatures that might involved in the prognosis significance of OC, and closely related the correlation between OC and PCOS. Furthermore, the hub gene, OGN, was a significant gene in the OC and PCOS progression via regulating the hormonal response.

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