MTOR/P70S6K Signaling Influence Synergistic Effect Of Electro-acupuncture Combined With BMSCs Transplantation On Synaptic Plasticity In Rats With Intracerebral Hemorrhage

Objective: To investigate the synergistic effect of electro-acupuncturestimulation (Ea) combined with bone marrow mesenchymal stem cells(BMSCs) transplantation on synaptic plasticity in rats with intracerebralhemorrhage via mammalian target of rapamycin (mTOR)/P70ribosomalprotein S6kinase (P70S6k) signaling. Methods: Adult male SD rats wereinjected with collagenase and heparin in the caudate nucleus to establish themodel of intracerebral hemorrhage (ICH).100ICH rats, whose NeurologicalSeverity Score (NSS) were more than or equal to9, were randomly dividedinto4groups (Ea-BMSCs group, Ea group, BMSCs group, normal salinegroup). The rats in BMSCs group and Ea-BMSCs group were transplanted20μl BMSCs suspension into the injury site, and the same volume of saline inNS group. Rats in Ea group and Ea-BMSCs group were stimulated at Baihuiand Dazhui once a day. Frozen section of rat brain were obtained afterperfusion and fixation in each group at1d,3d,5d,7d and14d timepoint. Thecorrelation was analysed through evaluating the expression of mTOR, P70S6k,synaptophysin (SYP), postsynaptic density-95(PSD-95) detected byimmunohistochemistry. Results:1. The number of mTOR-positive cellsreached the peak at5d in BMSCs group, Ea group and Ea-BMSCs group, but there was no significant differences in NS group at different timepoints.Compared with NS group at the same timepoint, the numbers ofmTOR-positive cells in other groups were significant increased (P <0.05). Thenumber of mTOR-positive cells in Ea-BMSCs group was significantly higherthan that in Ea group and BMSCs group at5d,7d,14d(P <0.05).2. Thenumber of P70S6k-positive cells reached the peak at5d in Ea-BMSCs group,while at7d in Ea and BMSCs groups, and there was no significant differencesin NS group at different timepoints. The number of P70S6k-positive cells inEa-BMSCs group was significantly higher than in NS group at same piont(P <0.05). At the same time, the number of P70S6k positive-cells in Ea group hadsignificant increase at5d and7d, comparing with NS group(P <0.05), and thesame situation occurred in BMSCs group at7d (P <0.05).3. The expression ofSYP upregulated to peak at5d in BMSCs, Ea-BMSCs and NS groups, and at7d in Ea group. Compared to the same time point, the SYP immunoreactiveproducts in Ea-BMSCs group was higher than that in Ea group and NS groupat all time points(P <0.05), and higher than that in BMSCs group at3d,5d,7d,14d (P <0.05). The expression of SYP in Ea group was higher than that inBMSCs group at3d,5d,7d,14d, while BMSCs group was higher than in NSgroup at5d,7d,14d (P <0.05).4. The expression of PSD-95immunoreactiveproducts in each group reached peak at7d. The expression of PSD-95in Ea-BMSCs group was higher than that in NS group (P <0.05), while Ea group at3d,5d,7d,14d (P <0.05) and BMSCs group at1d,7d,14d (P <0.05). The expression of PSD-95in Ea-BMSCs group was higher than that of Ea group at1d,3d,7d,14d (P <0.05), and higher than BMSCs group at3d,5d,7d,14d (P<0.05).5. The expressions of mTOR and P70S6K have positive correlationwith SYP and PSD-95(P <0.01). Conclusion:1. Combiningelectroacupuncture stimulation with BMSCs transplantation could upregulatethe experessions of mTOR and P70S6k in the perihematoma and activiate themTOR/P70S6k signalling.2. Combining electroacupuncture stimulation withBMSCs transplantation can promote the expressions of SYP and PSD-95toimprove synaptic plasticity, further beneficial to the recovery of neurologicalfunction in rats with ICH, compared to electroacupuncture stimulation orBMSCs transplantation alone.3. The expressions of mTOR and P70S6k havepositive correlation with that of SYP and PSD-95in ICH rats treated byelectroacupuncture stimulation with BMSCs transplantation, AndmTOR/P70S6k signaling pathway may play an important role in synapticplasticity of ICH rats.