RNA-Seq Reveals Underlying Transcriptomic Mechanisms of Bone Marrow-Derived Mesenchymal Stem Cells in the Regulation of Microglia-Mediated Neuroinflammation After Subarachnoid Hemorrhage

Subarachnoid hemorrhage (SAH) is a life-threatening cerebrovascular disease with high rates of morbidity and mortality. Microglia, the resident immune cells of the central nervous system, are involved in initiating inflammatory response post-SAH through releasing a variety of inflammatory mediators. Regulation of neuroinflammation triggered by activated microglia has become a promising therapeutic strategy for SAH. Recent studies reported that bone marrow-derived mesenchymal stem cells (BM-MSCs) have therapeutic effects, resulting from the regulation of microglia activation and production of inflammatory cytokines post-SAH. However, the underlying molecular mechanisms of BM-MSCs in targeting microglia-mediated neuroinflammation after SAH are still unclear. In this study, we used murine microglia cell line BV2 treated with oxyhemoglobin (OxyHb) to mimic the SAH conditions in vitro. The results showed that BM-MSCs coculture modulated OxyHb-induced BV2 activation as well as polarization. We further implemented RNA-seq approaches to investigate differences in transcriptomes between OxyHb-stimulated BV2 cocultured with and without BM-MSCs. The RNA-seq results suggested that the levels of inflammatory genes were strongly altered when OxyHb-stimulated BV2 cells were cocultured with BM-MSCs. Moreover, we identified epigenetic regulators involved in the regulation of microglia-mediated inflammation by BM-MSCs. This study clarifies detailed transcriptomic mechanisms underlying the interaction between BM-MSCs and activated microglia and may lead to a new therapeutic strategy using stem cell therapy for SAH.