Placental Mesenchymal Stem Cells Promote the Polarization of Astrocytes Towards the A2 Phenotype by Modulating the TGF-β1 Signaling Pathway in Cerebral Ischemia-Reperfusion Rats.

Astrocytic function imbalance is a key factor affecting cerebral ischemia rehabilitation. Mesenchymal stem cells have therapeutic potential for cerebral ischemia, but their mechanisms remain unclear. This study explored how placental mesenchymal stem cells pro-mote astrocytes towards the A2 phenotype, which benefits the repair of cerebral ischemia injury. We established the animal model of middle cerebral artery ischemia/reperfusion and an in vitro interleukin-1β-treated astrocyte inflammation model and utilized neuro-logical function assessment, 2,3,5-triphenyltetrazolium chloride staining, immunofluorescence staining, Western blotting and other methods to evaluate the impact and associated mechanisms of transplanting placental mesenchymal stem cells into rats with cerebral ischemia-reperfusion injuries. The results demonstrated that transplantation of placental mesenchymal stem cells ameliorated neurological dysfunction and histopathological damage, alleviated neuroinflammation and enhanced neurotrophic factor levels, promoted the polarization of interleukin-1β-treated astrocytes toward the A2 phenotype, and suppressed the abundance of core mediators within the cerebral TGF β1/Smad signaling cascade in ischemia/reperfusion model. Collectively, placental mesenchymal stem cell grafting facilitates the polarization of cerebral astrocytes toward the protective A2 phenotype, presumably by regulating the TGF β1/Smad signaling cascade in ischemic brain injury.