Huc-MSCs-derived exosomes attenuate inflammatory pain by regulating microglia pyroptosis and autophagy via the miR-146a-5p/TRAF6 axis

Abstract

Background Chronic inflammatory pain significantly reduces the quality of life and lacks effective interventions. In recent years, human umbilical cord mesenchymal stem cells (huc-MSCs)-derived exosomes have been used to relieve neuropathic pain and other inflammatory diseases as a promising cell-free therapeutic strategy. However, the therapeutic value of huc-MSCs-derived exosomes in complete Freund's adjuvant (CFA)-induced inflammatory pain remains to be confirmed. In this study, we investigated the therapeutic effect and related mechanisms of huc-MSCs-derived exosomes in a chronic inflammatory pain model. Methods C57BL/6J male mice were used to establish a CFA-induced inflammatory pain model, and huc-MSCs-derived exosomes were intrathecally injected for 4 consecutive days. BV2 microglia cells were stimulated with lipopolysaccharide (LPS) plus adenosine triphosphate (ATP) to investigate the effect of huc-MSCs-derived exosomes on pyroptosis and autophagy. Bioinformatic analysis and rescue experiments were used to demonstrate the role of miR-146a-5p/ TRAF6 in regulating pyroptosis and autophagy. Western blotting, RT-qPCR, small interfering RNA and Yo-Pro-1 dye staining were performed to investigate the related mechanisms. Results Huc-MSCs-derived exosomes alleviated mechanical allodynia and thermal hyperalgesia in CFA-induced inflammatory pain. Furthermore, huc-MSCs-derived exosomes attenuated neuroinflammation by increasing the expression of autophagy-related proteins (LC3-II and beclin1) and inhibiting the activation of NLRP3 inflammasomes in the spinal cord dorsal horn. In vitro, NLRP3 inflammasome components (NLRP3, caspase1-p20, ASC) and gasdermin D (GSDMD-F, GSDMD-N) were inhibited in BV2 cells pretreated with huc-MSCs-derived exosomes. Western blot and Yo-Pro-1 dye staining demonstrated that 3-MA, an autophagy inhibitor, weakened the protective effect of huc-MSCs-derived exosomes on BV2 cell pyroptosis. Importantly, huc-MSCs-derived exosomes transfected with miR-146a-5p mimic promoted autophagy and inhibited BV2 cell pyroptosis. TRAF6, as a target gene of miR-146a-5p, was knocked down via small-interfering RNA, which increased pyroptosis and inhibited autophagy. Conclusion Huc-MSCs-derived exosomes attenuated inflammatory pain via miR-146a-5p/TRAF6, which increased the level of autophagy and inhibited pyroptosis. Graphical Abstract

Downregulation of miR-146a-5p Promotes Acute Pancreatitis through Activating the TLR9/NLRP3 Signaling Pathway by Targeting TRAF6 In Vitro Rat Model

“…Our rescue experiment testified that miR-146a-5p downregulation can activate the further exacerbation of pancreatitis and activate the NLRP3 signaling pathway through the target TRAF6. Other studies have also confirmed that downregulation of TRAF6 by miR-146a-5p regulates pyroptosis and autophagy [17,32,33]. Therefore, miR-146a-5p may become a nucleic acid drug for inhibiting acute pancreatitis, which requires us to further conduct animal experiments and clinical trials.…”

Follicular fluid exosomes regulate OVGP1 secretion in yak oviduct epithelial cells via autophagy in vitro

“…Meanwhile, some studies have shown that microRNAs carried by exosomes participate in regulating autophagy (Hua et al, 2022;Luo et al, 2021). Recent studies have shown that follicular fluid-derived exosomal microRNA-18b-5p regulates the PI3K/Akt/mTOR signaling pathway inhibiting the development of polycystic ovary syndrome (Zhou et al, 2022).…”

Exosomes Derived from Yak Follicular Fluid Increase 2-Hydroxyestradiol Secretion by Activating Autophagy in Cumulus Cells

“…Follicular fluid EVs, which fill the ovarian follicle and influence oocyte developmental competency, can originate from the oocyte, cumulus, or mural granulosa cells in the ovarian follicle [ 28 ]. Initially, it was reported that huc-MSCs-derived exosomes could activate autophagy via miR-146a-5p/TRAF6 [ 29 ]. Breast cancer cell-derived exosomes were also reported to induce autophagy of breast cancer cells by transferring miR-1910-3p [ 30 ] while gastric cancer cell-derived exosomes were found to induce the autophagy of neutrophils via HMGB1/TLR4/NF-κB signaling [ 31 ].…”