精神发育迟滞相关基因CDKL3对神经元树突棘形态发育的影响

The role of non-syndromic mild mental retardation candidate gene CDKL3 in the development of neuronal dendrites spine

目的探讨精神发育迟滞相关基因CDKL3在神经元树突棘生长形成中的作用,以及CDKL3失活与精神发育迟滞间的内在联系。方法采用反转录实时定量聚合酶链反应(RT-realtime Quantitive PCR)方法检测内源性CDKL3基因在小鼠中枢神经系统发育中mRNA水平的时空表达,采用RNA干扰技术和免疫荧光组化方法研究CDKL3在小鼠活体神经元树突棘生长形成中的作用。结果 Cdkl3 mRNA在发育14 d的小鼠胚胎脑组织中即可检测到表达,出生时达峰值,随后下降,至出生后14 d时降至较低水平并维持至成年。采用RNA干扰技术敲减小鼠活体中枢神经系统神经元中的CDKL3可引起神经元树突棘密度显著减少,而上调神经元细胞中的CDKL3可引起相反的结果,并且敲减CDKL3对神经元的病理影响可被转染入神经元的RNA干扰质粒相对应的CDKL3-Res质粒所拯救。结论 CDLK3的表达和活动在神经元树突棘的生长形成中具有至关重要的作用,CDKL3失活引起神经元树突棘形态发育异常极可能是非综合征轻型精神发育迟滞的一个重要病理机制。

Objective To investigate the role of CDKL3 in the development of neuronal spines and further reveal the underlying relationship between CDKL3 inactivation and the non-syndromic mild mental retardation（MR）.Methods The distribution and expression of Cdkl3 mRNA in developing nervous system in mouse were investigated by method of RT-Quantitive PCR.The role of CDKL3 in the development of neuronal spines in vivo were studied by the method of RNA interference and immunofluorescence.Results RT-PCR result showed that Cdkl3 mRNA was detectable at the 14th day,and reached its peak at birth.Afterwards,it declined slightly and was maintained at low level from the 14th day after birth to adulthood.CDKL3 depletion inhibited the formation of spines,whereas CDKL3 upregulation had the opposite effects,and the co-expression of CDKL3-Res prevented the shRNA-#2-mediated defects.Conclusions CDKL3 played a critical role in the development of neuronal spines.Furthermore,CDKL3 inactivation maybe contribute to non-syndromic mild MR by affecting spines morphogenesis during crucial stages of their formation.