Abstract：
Genetic perturbations influencing early eye development can result in microphthalmia, anophthalmia, and coloboma (MAC). Over 100 genes are associated with MAC, but little is known about common disease mechanisms. In this study, we generated induced pluripotent stem cell (iPSC)-derived optic vesicles (OVs) from two unrelated microphthalmia patients and healthy controls. At day 20, 35, and 50, microphthalmia patient OV diameters were significantly smaller, recapitulating the \"small eye\" phenotype. RNA sequencing (RNA-seq) analysis revealed upregulation of apoptosis-initiating and extracellular matrix (ECM) genes at day 20 and 35. Western blot and immunohistochemistry revealed increased expression of lumican, nidogen, and collagen type IV, suggesting ECM overproduction. Increased apoptosis was observed in microphthalmia OVs with reduced phospho-histone 3 (pH3+) cells confirming decreased cell proliferation at day 35. Pharmacological inhibition of caspase-8 activity with Z-IETD-FMK decreased apoptosis in one patient model, highlighting a potential therapeutic approach. These data reveal shared pathophysiological mechanisms contributing to a microphthalmia phenotype.
摘要：
影响早期眼部发育的遗传扰动可导致小眼症，无眼炎,和结肠瘤（MAC）。超过100个基因与MAC相关，但对常见疾病机制知之甚少。在这项研究中,我们从两名无关的小眼症患者和健康对照中产生了诱导多能干细胞(iPSC)衍生的光学囊泡(OVs).在第20、35和50天，小眼症患者OV直径明显变小，概括“小眼”表型。RNA测序（RNA-seq）分析显示，在第20天和第35天，凋亡起始和细胞外基质（ECM）基因上调。Westernblot和免疫组织化学显示lumican的表达增加，Nidogen,还有IV型胶原,表明ECM生产过剩。在第35天,在具有减少的磷酸-组蛋白3(pH3+)细胞的小眼症OVs中观察到增加的细胞凋亡,证实细胞增殖减少。在一个患者模型中，用Z-IETD-FMK抑制caspase-8活性的药理学抑制降低了细胞凋亡，强调一种潜在的治疗方法。这些数据揭示了导致小眼症表型的共同病理生理机制。
