The mechanism of Ca2+ ion inflow regulated by KF506 binding proteins (FKBP) and Calcineurin.

我们研究了Ca2+离子流入神经元和肌肉细胞的机制由FKBPs （FK506结合蛋白）和钙调磷酸酶调节。我们进一步研究了疾病动物模型中Ca2+流入的病理生理机制。用已建立的和原代培养的细胞系统和大鼠肥厚性膀胱模型进行研究。通过两年的深入研究，我们得到了以下结果：1)我们建立了胎鼠海马神经元原代培养，并通过谷氨酸和nmda诱导兴奋性神经元细胞死亡。2)我们发现钙调磷酸酶抑制剂FK506和环孢素A抑制兴奋性神经元细胞死亡，而雷帕霉素对兴奋性神经元细胞死亡没有抑制作用。钙离子流入和钙调磷酸酶的连续激活是诱导神经元死亡的先决条件。4)活化的钙调磷酸酶诱导转录因子NF-AT从细胞质向神经元核室易位。在肥厚性膀胱模型中，1)我们观察了肥大诱导过程中肌动蛋白和肌球蛋白表达的增加以及钙调磷酸酶表达的变化。2)钙调磷酸酶抑制剂FK506抑制膀胱肥大。3)增生性膀胱平滑肌细胞Ca2+离子通过ATP依赖的Ca通道流入增加。

We investigated the mechanism of Ca2+ ion inflow into neurons and muscle cells regulated by FKBPs (FK506 binding proteins) and Calcineurin. We further investigated Pathophysiological mechanism of Ca2+ inflow in animal model of diseases. Established and primary cultured cell systems and a rat hypertrophic urinary bladder model were used for this investigations. In intensive research for two years supported by this grant, we have got results as follows,1) We established primary culture of fetal rat hippocampal neurons and induced excitatory neuronal cell death by glutamate and NMDA.2) We showed that calcineurin inhibitors, FK506 and Cyclosporin A inhibited the excitatory neuronal cell death but not Rapamycin.3) In the excitatory neuronal cell death, the Ca2+ ion inflow and the successive activation of calcineurin is essentially important as prerequisites for the induction of neuron death.4) The activated calcineurin induced translocation of a transcription factor, NF-AT from cytoplasm to nuclear compartment of neurons.In a hypertrophic urinary bladder model,1) We showed the increment of actin and myosin expression and the change of calcineurin expression during hypertrophy induction.2) Calcineurin inhibitor, FK506 inhibited bladder hypertrophy.3) Hypertrophic bladder smooth muscle cells showed increased Ca2+ ion inflow through ATP dependent Ca channels.