Department of Cell Biology and Neuroscience, Rutgers, The State University of New Jersey, Piscataway, NJ, USA; Neurosciences Graduate Program, Rutgers, The State University of New Jersey, Piscataway, NJ, USA.
Department of Cell Biology and Neuroscience, Rutgers, The State University of New Jersey, Piscataway, NJ, USA; Molecular Biosciences Graduate Program, Rutgers, The State University of New Jersey, Piscataway, NJ, USA.
Mol Cell Neurosci. 2020 Dec;109:103562. doi: 10.1016/j.mcn.2020.103562. Epub 2020 Sep 26.
Abnormal dendritic arbor development has been implicated in a number of neurodevelopmental disorders, such as autism and Rett syndrome, and the neuropsychiatric disorder schizophrenia. Postmortem brain samples from subjects with schizophrenia show elevated levels of NOS1AP in the dorsolateral prefrontal cortex, a region of the brain associated with cognitive function. We previously reported that the long isoform of NOS1AP (NOS1AP-L), but not the short isoform (NOS1AP-S), negatively regulates dendrite branching in rat hippocampal neurons. To investigate the role that NOS1AP isoforms play in human dendritic arbor development, we adapted methods to generate human neural progenitor cells and neurons using induced pluripotent stem cell (iPSC) technology. We found that increased protein levels of either NOS1AP-L or NOS1AP-S decrease dendrite branching in human neurons at the developmental time point when primary and secondary branching actively occurs. Next, we tested whether pharmacological agents can decrease the expression of NOS1AP isoforms. Treatment of human iPSC-derived neurons with d-serine, but not clozapine, haloperidol, fluphenazine, or GLYX-13, results in a reduction in endogenous NOS1AP-L, but not NOS1AP-S, protein expression; however, d-serine treatment does not reverse decreases in dendrite number mediated by overexpression of NOS1AP isoforms. In summary, we demonstrate how an in vitro model of human neuronal development can help in understanding the etiology of schizophrenia and can also be used as a platform to screen drugs for patients.
异常树突分支发育与许多神经发育障碍有关，如自闭症和雷特综合征，以及神经精神障碍精神分裂症。精神分裂症患者的死后大脑样本显示，在与认知功能相关的大脑背外侧前额叶皮层中，NOS1AP 的水平升高。我们之前报道过，NOS1AP 的长异构体（NOS1AP-L），而不是短异构体（NOS1AP-S），负调控大鼠海马神经元的树突分支。为了研究 NOS1AP 异构体在人类树突分支发育中的作用，我们采用了使用诱导多能干细胞（iPSC）技术生成人类神经祖细胞和神经元的方法。我们发现，无论是 NOS1AP-L 还是 NOS1AP-S 的蛋白水平增加，都会在初级和次级分支活跃发生的发育时间点减少人类神经元的树突分支。接下来，我们测试了是否可以用药物来降低 NOS1AP 异构体的表达。用 D-丝氨酸处理人 iPSC 衍生的神经元，而不是用氯氮平、氟哌啶醇、氟奋乃静或 GLYX-13，会导致内源性 NOS1AP-L 的表达减少，但 NOS1AP-S 的表达没有减少；然而，D-丝氨酸处理不能逆转由 NOS1AP 异构体过表达介导的树突数量减少。总之，我们展示了一种体外人类神经元发育模型如何有助于理解精神分裂症的病因，并且也可以作为筛选患者药物的平台。
