Bone marrow-derived mesenchymal stem cell-derived exosome-loaded miR-129-5p targets high-mobility group box 1 attenuates neurological-impairment after diabetic cerebral hemorrhage.

Background: Diabetic intracerebral hemorrhage (ICH) is a serious complication of diabetes. The role and mechanism of bone marrow mesenchymal stem cell (BMSC)-derived exosomes (BMSC-exo) in neuroinflammation post-ICH in patients with diabetes are unknown. In this study, we investigated the regulation of BMSC-exo on hyperglycemia-induced neuroinflammation.

Aim: To study the mechanism of BMSC-exo on nerve function damage after diabetes complicated with cerebral hemorrhage.

Methods: BMSC-exo were isolated from mouse BMSC media. This was followed by transfection with microRNA-129-5p (miR-129-5p). BMSC-exo or miR-129-5p-overexpressing BMSC-exo were intravitreally injected into a diabetes mouse model with ICH for in vivo analyses and were cocultured with high glucose-affected BV2 cells for in vitro analyses. The dual luciferase test and RNA immunoprecipitation test verified the targeted binding relationship between miR-129-5p and high-mobility group box 1 (HMGB1). Quantitative polymerase chain reaction, western blotting, and enzyme-linked immunosorbent assay were conducted to assess the levels of some inflammation factors, such as HMGB1, interleukin 6, interleukin 1β, toll-like receptor 4, and tumor necrosis factor α. Brain water content, neural function deficit score, and Evans blue were used to measure the neural function of mice.

Results: Our findings indicated that BMSC-exo can promote neuroinflammation and functional recovery. MicroRNA chip analysis of BMSC-exo identified miR-129-5p as the specific microRNA with a protective role in neuroinflammation. Overexpression of miR-129-5p in BMSC-exo reduced the inflammatory response and neurological impairment in comorbid diabetes and ICH cases. Furthermore, we found that miR-129-5p had a targeted binding relationship with HMGB1 mRNA.

Conclusion: We demonstrated that BMSC-exo can reduce the inflammatory response after ICH with diabetes, thereby improving the neurological function of the brain.