Targeting the AKT/mTOR/p70S6K Pathway for Oligodendrocyte Differentiation and Myelin Regeneration in Neurological Disorders.

ABSTRACT

BACKGROUND: The AKT/mTOR/p70S6K pathway has been shown to potentially promote spinal cord injury (SCI) repair in rats. However, its exact mechanism and beyond needs to be further explored. OBJECTIVE: This study aims to explore the AKT/mTOR/p70S6K pathway in oligodendrocyte precursor cell (OPC) differentiation, microglial polarization differentiation, and the role of these in myelin regeneration in vitro. METHODS: The isolation, induction and characterization of rat primary neuronal stem cells, OPCs and oligodendrocytes were investigated with immunofluorescence and RT-qPCR. Then, the role of AKT/mTOR/p70S6K signaling was explored using western blotting and immunofluorescence, the effect on myelination was examined with OPC-dorsal root ganglion (DRG) neurons co-culture, and the influence of M1/M2 polarization status of microglia on myelin formation was also observed by adding M1/M2 supernatants into OPC-DRG neurons co-culture. RESULTS: Activation of the AKT/mTOR/p70S6K pathway elevated the expression of oligodendrocyte differentiation markers, including MBP, PLP and MOG, which also promoted the colocalization of MBP and NFH in OPC-DRG neurons co-culture. More interestingly, stimulation of the AKT/mTOR/p70S6K pathway facilitated M2 polarization of rat microglia. M2 polarization of microglia enhanced OPC differentiation to oligodendrocytes and myelin formation. CONCLUSION: Our findings highlight the potential of targeting the AKT/mTOR/p70S6K pathway in promoting oligodendrocyte differentiation and myelin regeneration in neurological disorders such as SCI.