Using Rna Interference Technology To Inhibit The Activity Of Calcineurin Preliminary Study

Objectives To build the technical platform inhibiting expression of calcineurin with RNAi strategy , validate its inhibitory effect in primary cultured rat myocardial cells and vessel smooth muscle cells and lay a foundation for the using of RNAi technique to treat cardiac diseases and cardiac- cerebral vessels diseases.Methods A:Rat aorta thoracalis smooth muscle cells(VESSEL SMOOTH MUSCLE CELLSs) were primary cultured in vitro by tissuepiece anchorage primary culture method and stimulated by neuropeptide Y(NPY) .RNAi targeting calcineurin(CaN) was used to decrease mRNA level of CaN and its activity in cultured VESSEL SMOOTH MUSCLE CELLSs in order to block the CaN -dependent signal pathway provoked by NPY. Activity of CaN , cell proliferation rate and c-fos expression level were assesd to elucidate the role of CaN in rat vessel smooth muscle cells. B:Rat myocardial cells were primary cultured in vitro by differential attachment method then stimulated by NPY. RNAi was used to inhibit specificly the activity of CaN to block the Ca²⁺/CaM-CaN signal pathway provoked by NPY.Then the activity and expression level of CaN as well as protein synthesis rate of myocardio cells were determined.Results A:CaN activcity, cell proliferation and nuclear c-fos expression level of VESSEL SMOOTH MUSCLE CELLSs can be raised by NPY stimulation. Cell proliferation rate and nuclear c-fos level of VESSEL SMOOTH MUSCLE CELLSs after NPY stimulation can be significantly diminished when CaN activity was inhibited with RNAi targeting CaN. B: Acivity and expression level of CaN as well as protein synthesis rate of my°Cardio cells can be elevated by NPY stimulation. Protein synthesis rate of myocardio cells can be lowered significantly following inhibition of CaN activity with RNAi targeting CaN.Conclusions CaN is involved in the proliferation of VESSEL SMOOTH MUSCLE CELLS and hypertrophy of myocardio cells which are induced by NPY stimulation . This kind of proliferation and hypertrophy can be prohibited by RNAi targeting CaN.