Conclusions
The present work demonstrated that miR-137 and its target T-type CaV 3.1 channel modulate the dedifferentiation and proliferation of rat cerebral VSMCs under simulated microgravity by regulating calcineurin/NFATc3 pathway.
Methods
Sprague Dawley rats were subjected to 28-day hindlimb-unloading to simulate microgravity exposure. VSMC dedifferentiation was evaluated by ultrastructural analysis and contractile/synthetic maker detection. The role of T-type CaV 3.1 channel was revealed by assessing its blocking effects. MiR-137 was identified as the upstream of CaV 3.1 channel by luciferase assay and investigated by gain/loss-of-function approaches. Calcineurin/nuclear factor of activated T lymphocytes (NFAT) pathway, the downstream of CaV 3.1 channel, was investigated by detecting calcineurin activity and NFAT nuclear translocation.
Results
Simulated microgravity induced the dedifferentiation and proliferation in rat cerebral VSMCs. T-type CaV 3.1 channel promoted the dedifferentiation and proliferation of VSMC. MiR-137 and calcineurin/NFATc3 pathway were the upstream and downstream signalling of T-type CaV 3.1 channel in modulating the dedifferentiation and proliferation of VSMCs, respectively. Conclusions: The present work demonstrated that miR-137 and its target T-type CaV 3.1 channel modulate the dedifferentiation and proliferation of rat cerebral VSMCs under simulated microgravity by regulating calcineurin/NFATc3 pathway.