Bridging Integrator 1 (BIN1) is the second most important Alzheimer’s disease (AD) risk gene, but its physiological roles in neurons and its contribution to brain pathology remain largely elusive. In this work, we show that BIN1 plays a critical role in the regulation of calcium homeostasis, electrical activity, and gene expression of glutamatergic neurons. Using single-cell RNA-sequencing on cerebral organoids generated from isogenic BIN1 wild type (WT), heterozygous (HET) and homozygous knockout (KO) human-induced pluripotent stem cells (hiPSCs), we show that BIN1 is mainly expressed by oligodendrocytes and glutamatergic neurons, like in the human brain. Both BIN1 HET and KO cerebral organoids show specific transcriptional alterations, mainly associated with ion transport and synapses in glutamatergic neurons. We then demonstrate that BIN1 cell-autonomously regulates gene expression in glutamatergic neurons by using a novel protocol to generate pure culture of hiPSC-derived induced neurons (hiNs). Using this system, we also show that BIN1 plays a key role in the regulation of neuronal calcium transients and electrical activity via its interaction with the L-type voltage-gated calcium channel Cav_1.2. BIN1 KO hiNs show reduced activity-dependent internalization and higher Cav_1.2 expression compared to WT hiNs. Pharmacological blocking of this channel with clinically relevant doses of nifedipine, a calcium channel blocker, partly rescues electrical and gene expression alterations in BIN1 KO glutamatergic neurons. Further, we show that transcriptional alterations in BIN1 KO hiNs that affect biological processes related to calcium homeostasis are also present in glutamatergic neurons of the human brain at late stages of AD pathology. Together, these findings suggest that BIN1-dependent alterations in neuronal properties could contribute to AD pathophysiology and that treatment with low doses of clinically approved calcium blockers should be considered as an option to slow disease-onset and progression.

桥接整合子 1 （BIN1） 是阿尔茨海默病 （AD） 第二重要的风险基因，但它在神经元中的生理作用及其对脑病理学的贡献在很大程度上仍然难以捉摸。在这项工作中，我们表明 BIN1 在调节钙稳态、电活动和谷氨酸能神经元的基因表达中起关键作用。使用由同基因 BIN1 野生型 （WT）、杂合子 （HET） 和纯合子敲除 （KO） 人诱导多能干细胞 （hiPSC） 产生的脑类器官的单细胞 RNA 测序，我们表明 BIN1 主要由少突胶质细胞和谷氨酸能神经元表达，就像在人脑中一样。BIN1 HET 和 KO 脑类器官均显示出特异性转录改变，主要与谷氨酸能神经元中的离子转运和突触有关。然后，我们证明 BIN1 细胞通过使用一种新的方案生成 hiPSC 衍生诱导神经元 （hiNs） 的纯培养物来自主调节谷氨酸能神经元中的基因表达。使用该系统，我们还表明 BIN1 通过与 L 型电压门控钙通道 Cav_1.2 的相互作用，在神经元钙瞬变和电活动的调节中发挥关键作用。BIN1与 WT hiN 相比，KO hiN 显示出活性依赖性内化降低和 Cav_1.2 表达升高。用临床相关剂量的硝苯地平（一种钙通道阻滞剂）对该通道进行药物阻断，部分挽救了 BIN1 KO 谷氨酸能神经元的电和基因表达改变。 此外，我们表明，在 AD 病理学的晚期，影响与钙稳态相关的生物过程的 BIN1 KO hiN 的转录改变也存在于人脑的谷氨酸能神经元中。总之，这些发现表明 BIN1 神经元特性的依赖性改变可能导致 AD 病理生理学，并且应考虑使用低剂量临床批准的钙阻滞剂进行治疗作为减缓疾病发作和进展的一种选择。