Lefler Sharon, Cohen Malkiel A, Kantor Gal, Cheishvili David, Even Aviel, Birger Anastasya, Turetsky Tikva, Gil Yaniv, Even-Ram Sharona, Aizenman Einat, Bashir Nibal, Maayan Channa, Razin Aharon, Reubinoff Benjamim E, Weil Miguel
Laboratory for Neurodegenerative Diseases and Personalized Medicine, Department of Cell Research and Immunology, The George S. Wise Faculty of Life Sciences, The Sagol School of Neurosciences, Tel Aviv University, Tel Aviv, Israel.
The Hadassah Human Embryonic Stem Cell Research Center, The Goldyne Savad Institute of Gene Therapy, Hadassah Hebrew University Medical Center, Ein Kerem, Jerusalem, Israel.
PLoS One. 2015 Oct 5;10(10):e0138807. doi: 10.1371/journal.pone.0138807. eCollection 2015.
A splicing mutation in the IKBKAP gene causes Familial Dysautonomia (FD), affecting the IKAP protein expression levels and proper development and function of the peripheral nervous system (PNS). Here we found new molecular insights for the IKAP role and the impact of the FD mutation in the human PNS lineage by using a novel and unique human embryonic stem cell (hESC) line homozygous to the FD mutation originated by pre implantation genetic diagnosis (PGD) analysis. We found that IKBKAP downregulation during PNS differentiation affects normal migration in FD-hESC derived neural crest cells (NCC) while at later stages the PNS neurons show reduced intracellular colocalization between vesicular proteins and IKAP. Comparative wide transcriptome analysis of FD and WT hESC-derived neurons together with the analysis of human brains from FD and WT 12 weeks old embryos and experimental validation of the results confirmed that synaptic vesicular and neuronal transport genes are directly or indirectly affected by IKBKAP downregulation in FD neurons. Moreover we show that kinetin (a drug that corrects IKBKAP alternative splicing) promotes the recovery of IKAP expression and these IKAP functional associated genes identified in the study. Altogether, these results support the view that IKAP might be a vesicular like protein that might be involved in neuronal transport in hESC derived PNS neurons. This function seems to be mostly affected in FD-hESC derived PNS neurons probably reflecting some PNS neuronal dysfunction observed in FD.
IKBKAP基因中的剪接突变会导致家族性自主神经功能障碍(FD),影响IKAP蛋白的表达水平以及外周神经系统(PNS)的正常发育和功能。在此,我们通过使用一种新颖独特的人类胚胎干细胞(hESC)系,该细胞系通过植入前基因诊断(PGD)分析对FD突变纯合,从而获得了关于IKAP作用以及FD突变对人类PNS谱系影响的新分子见解。我们发现,在PNS分化过程中IKBKAP的下调会影响FD - hESC衍生的神经嵴细胞(NCC)的正常迁移,而在后期阶段,PNS神经元中囊泡蛋白与IKAP之间的细胞内共定位减少。对FD和WT hESC衍生神经元进行比较广泛的转录组分析,以及对FD和WT 12周龄胚胎的人类大脑进行分析,并对结果进行实验验证,证实了FD神经元中突触囊泡和神经元运输基因直接或间接受到IKBKAP下调的影响。此外,我们表明激动素(一种纠正IKBKAP可变剪接的药物)可促进IKAP表达的恢复以及本研究中鉴定的这些与IKAP功能相关的基因的恢复。总之,这些结果支持这样一种观点,即IKAP可能是一种类似囊泡的蛋白,可能参与hESC衍生的PNS神经元中的神经元运输。这种功能似乎在FD - hESC衍生的PNS神经元中受到的影响最大,这可能反映了在FD中观察到的一些PNS神经元功能障碍。