TNF-α Enhances the Therapeutic Effects of MenSC-Derived Small Extracellular Vesicles on Inflammatory Bowel Disease through Macrophage Polarization by miR-24-3p

Abstract

Human menstrual blood-derived mesenchymal stem cells (MenSCs) and their secreted small extracellular vesicles (EVs) had been proven to relieve inflammation, tissue damage, and fibrosis in various organs. The microenvironment induced by inflammatory cytokines can promote mesenchymal stem cells (MSCs) to secrete more substances (including EVs) that could regulate inflammation. Inflammatory bowel disease (IBD) is a chronic idiopathic intestinal inflammation, the etiology and mechanism of which are unclear. At present, the existing therapeutic methods are ineffective for many patients and have obvious side effects. Hence, we explored the role of tumor necrosis factor α- (TNF-α-) pretreated MenSC-derived small EV (MenSCs-sEVTNF-α) in a mouse model of dextran sulfate sodium- (DSS-) induced colitis, expecting to find better therapeutic alterations. In this research, the small EVs of MenSCs were obtained by ultracentrifugation. MicroRNAs of small EVs derived from MenSCs before and after TNF-α treatment were sequenced, and the differential microRNAs were analyzed by bioinformatics. The small EVs secreted by TNF-α-stimulating MenSCs were more effective in colonic mice than those secreted directly by MenSCs, as evidenced by the results of histopathology analysis of colonic tissue, immunohistochemistry for tight junction proteins, and enzyme-linked immunosorbent assay (ELISA) for cytokine expression profiles in vivo. The process of MenSCs-sEVTNF-α relieving colonic inflammation was accompanied by the polarization of M2 macrophages in the colon and miR-24-3p upregulation in small EVs. In vitro, both MenSC-derived sEV (MenSCs-sEV) and MenSCs-sEVTNF-α reduced the expression of proinflammatory cytokines, and MenSCs-sEVTNF-α can increase the portion of M2 macrophages. In conclusion, after TNF-α stimulation, the expression of miR-24-3p in small EVs derived from MenSCs was upregulated. MiR-24-3p was proved to target and downregulate interferon regulatory factor 1 (IRF1) expression in the murine colon and then promoted the polarization of M2 macrophages. The polarization of M2 macrophages in colonic tissues then reduced the damage caused by hyperinflammation.

Exosomes derived from TNF-α-treated bone marrow mesenchymal stem cells ameliorate myocardial infarction injury in mice

“… 22 , 23 Notably, exosomes released by MSCs in response to inflammatory cytokines have been demonstrated to regulate macrophage polarization, which is crucial for myocardial infarction repair. 24 , 25 These findings demonstrate that the anti-inflammatory activities of these exosomes could be enhanced if derived from the cytokine-pretreated MSCs, which may further promote their ability for the MI treatment. In this study, we investigated the impact of TNF-α stimulation on BMSCs in enhancing therapeutic potential of exosomes derived from these cells for myocardial infarction repair.…”

Macrophage polarization: an important role in inflammatory diseases

“…Changes in macrophage homeostasis can affect IBD, such as sphingosine 1-phosphate receptor 2 (S1PR2) and its downstream G protein RhoA/Rho kinase 1 (ROCK1) signaling pathway can aggravate IBD by regulating polarization to M1-like macrophages, in addition, Yes-related protein (YAP) can inhibit M2-like macrophages and promote the production of IL-6 in M1-like macrophages to regulate the pathological process of IBD ( 88 , 89 ). Instead, under the influence of diosgenin and TNF-α, respectively, miR-125a-5p and miR-24-3p can enhance the polarization of M2-like macrophages, relieving IBD ( 90 , 91 ). In this review, we summarized the mechanism of macrophage polarization in CD and UC, as well as some clinical applications.…”

Research advancements and perspectives of inflammatory bowel disease: A comprehensive review

“…miRNAs in exosomes play an important role in IBD. 145 For example, macrophage-derived exosomal miR-223 induces intestinal barrier dysfunction via inhibiting transmembrane and immunoglobulin domain containing 1. 146 Several studies indicate that miRNAs extend the potential therapeutic effects on IBD through exosomes-mediated intercellular delivery.…”

“… 149 With TNF-α treatment, the expression of miR-24-3p in small extracellular vesicles derived from human menstrual blood-derived MSCs is upregulated, which decreases IRF1 level and then promotes the M2 macrophages polarization to reduce the damage caused by hyperinflammation. 145 …”