2022, Vol. 26 ›› Issue (30): 4787-4792

Possibility of forskolin and 3-isobutyl-1-methylxanthine in inducing bone marrow mesenchymal stem cells to differentiate into Schwann cells-like phenotype

Wu Xiaosong1, Gong Chao1, Lou Pan1, Wang Wei2, 3, 4     

Abstract: BACKGROUND: Peripheral nerve injury is a common clinical disease mainly caused by trauma and other factors. Studies have shown that Schwann cells transdifferentiated from bone marrow mesenchymal stem cells can promote the repair and reconstruction of peripheral nerve injury, but the induction method has not yet reached a consensus, and the mechanism of cell neurotransdifferentiation is still unclear.  
OBJECTIVE: To investigate the feasibility of the small molecule compounds (Forskolin and 3-isobutyl-1-methylxanthine, Fsk-IBMX, FI) induced bone marrow mesenchymal stem cells to differentiate into Schwann cells, and the correlation between the induction process and the cAMP/PKA pathway.
METHODS:   The primary bone marrow mesenchymal stem cells were extracted from the bone marrow of the limbs of 1-week-old SD rats by the whole bone marrow adherence method. The bone marrow mesenchymal stem cells were identified by cellular immunofluorescence. The changes of proliferation activity of each generation of bone marrow mesenchymal stem cells were detected by CCK-8 assay at different time points of culture. Bone marrow mesenchymal stem cells were induced by FI in vitro. The experiment contained three groups. The samples in the control group were treated with nerve growth medium for 120 hours. Those in the induction group were treated with nerve growth medium + FSK + IBMX + SQ22536 for 120 hours. Those in the inhibition group were treated with nerve growth medium + FSK + IBMX + SQ22536 treated for 120 hours. The medium should be replaced every 60 hours. Schwann cell-like cells were identified and analyzed by cell morphology and western bot assay. The expression of cAMP-related proteins during the differentiation was detected.  
RESULTS AND CONCLUSION: (1) Cell immunofluorescence staining showed that primary cells from the limb bone marrow of one-week-old SD rats could be labeled with BMSCs-specific markers CD44 and CD90. CCK-8 assay results showed that the proliferation activity of bone marrow mesenchymal stem cells increased gradually from passage 1 to passage 3 and decreased gradually from passage 3 to passage 6 at the same time point of culture. (2) Western blot assay results demonstrated that the expression of Schwann cells-specific markers S100β, GFAP, p75, and cAMP-related protein p-CREB increased significantly after FI induction (P < 0.001; P < 0.001; P < 0.05; P < 0.000 1), while the cAMP/PKA inhibitors SQ22536 could inhibit this effect (P < 0.01; P < 0.01; P < 0.05; P < 0.001). (3) It is concluded that FI can induce bone marrow mesenchymal stem cells to differentiate into Schwann cells phenotype and may activate the cAMP/PKA pathway during this induction process.
Key words: bone marrow mesenchymal stem cells, Forskolin, 3-isobutyl-1-methylxanthine, Schwann cells, cAMP, PKA, pathway