Bone Marrow Mesenchymal Stem-Cell-Derived Exosomes Ameliorate Deoxynivalenol-Induced Mice Liver Damage.

Deoxynivalenol (DON) is a kind of Fusarium toxin that can cause a variety of toxic effects. DON is mainly metabolized and detoxified by the liver. When the concentration of DON exceeds the metabolic capacity of the liver, it will trigger acute or chronic damage to the liver tissue. Previous studies demonstrated that bone marrow mesenchymal stem-cell-secreted exosomes (BMSC-exos) reduce liver injury. Therefore, we issue a hypothesis that in vitro-cultured rat BMSC-secreted exos could ameliorate liver damage after 2 mg/kg bw/day of DON exposure. In total, 144 lipids were identified in BMEC-exos, including high polyunsaturated fatty acid (PUFA) levels. BMSC-exos treatment alleviated liver pathological changes and decreased levels of alanine aminotransferase, aspartate aminotransferase, inflammatory factors interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and lipid peroxidation. Otherwise, low or high BMSC-exos treatment obviously changes DON-induced hepatic oxylipin patterns. According to the results from our correlation network analysis, Pearson correlation coefficient analysis, and hierarchical clustering analysis, the top 10% oxidized lipids can be classified into two categories: one that was positively correlated with copper-zinc superoxide dismutase (Cu/Zn SOD) and another that was positively correlated with liver injury indicators. Altogether, BMSC-exos administration maintained normal liver function and reduced oxidative damage in liver tissue. Moreover, it could also significantly change the oxylipin profiles under DON conditions.

Bone marrow mesenchymal stem cell-derived exosome miR-29b-3p alleviates UV irradiation-induced photoaging in skin fibroblast.

BACKGROUND: Mesenchymal stem cells-derived exosome (MSCs-exo) was identified to reduce photoaging. The purpose of this study was to investigate the potential role of microRNA (miR)-29b-3p derived from bone marrow MSCs-exo (BMSCs-exo) in photoaging. METHODS: Exosomes were isolated from BMSCs and verified by Western blot. A photoaging cell model was constructed by UVB irradiation of human dermal fibroblasts (HDFs). Quantitative real-time PCR (RT-qPCR) was performed to detect the mRNA levels of miR-29b-3p, collagen type I and matrix metalloproteinases (MMPs). CCK-8, Transwell and flow cytometry were applicated to examine cell viability, migration and apoptosis. Commercial kits are used to measure levels of oxidative stress indicators. Finally, a dual-luciferase reporter assay was applied to validate the target of miR-29b-3p. RESULTS: Extracted exosomes were positive for HSP70 and CD9. Survival of HDFs increased in an exosome concentration-dependent manner. UVB irradiation inhibited miR-29b-3p levels compared with controls, but BMSCs-exo treatment restored miR-29b-3p levels (p < .05). Additionally, BMSCs-exo-miR-29b-3p reversed the inhibition of HDFs migration and oxidative stress by UVB irradiation, as well as the promotion of apoptosis. However, this reversal was attenuated by the suppression of miR-29b-3p (p < .05). Furthermore, BMSCs-exo-miR-29b-3p also inhibited the degradation of collagen type I and the production of MMPs in photoaging, and they were also eliminated by the reduced miR-29b-3p. Finally, MMP-2 was the target gene of miR-29b-3p. CONCLUSION: Our study presented a novel role for BMSCs-exo-miR-29b-3p in improving skin photoaging function, and these findings may provide new insights into the targeted treatment of skin photoaging.

Bone Marrow Mesenchymal Stem Cell-Derived Exosomal miR-25 Regulates the Ubiquitination and Degradation of Runx2 by SMURF1 to Promote Fracture Healing in Mice.

Recent evidence has demonstrated that mesenchymal stem cells (MSCs) can release a large number of functionally specific microRNA (miRNA) microvesicles that play a role in promoting osteogenic differentiation, but the specific mechanism is not yet clear. Under such context, this study aims to elucidate the mechanism of bone marrow mesenchymal stem cell-derived exosomes (BMSC-Exo) promoting fracture healing in mice. We isolated and identified the BMSC-Exo. Bioinformatics analysis predicted high expression of miRNA in exosomes and verified the transfer of miR-25 in exosomes by immunofluorescence. Targeting relationship between miR-25 and Smad ubiquitination regulatory factor-1 (SMURF1) was predicted and verified by dual-luciferase reporter gene assay. Immunoprecipitation and protein stability assays were used to detect Runt-related transcription factor 2 (Runx2) ubiquitination and the effect of SMURF1 on Runx2 ubiquitination, respectively. The effect of miR-25 in BMSC-Exo on fracture healing in mice was assessed using X-ray imaging. alkaline phosphatase, alizarin red staining, EdU, CCK-8, and Transwell were used to evaluate the effects of exosomes transferred miR-25 on osteogenic differentiation, proliferation, and migration of osteoblasts. Bioinformatics analysis predicted that miR-25 expression in exosomes increased significantly. Moreover, the targeted regulation of SMURF1 by miR-25 was verified. SMURF1 inhibited Runx2 protein expression by promoting ubiquitination degradation of Runx2. Notably, miR-25 secreted by BMSC-Exo can accelerate osteogenic differentiation, proliferation, and migration of osteoblasts through SMURF1/Runx2 axis. Our results demonstrate that miR-25 in BMSC-Exo regulates the ubiquitination degradation of Runx2 by SMURF1 to promote fracture healing in mice.