Impaired reprogramming and differentiation of iPSCs in T1D with complications
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Low cell apoptosis due to intact DNA checkpoint pathway in T1D without complications
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Poor DNA repair rescued by knockdown of miR200 in T1D patients with complications
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Differentiated neurons from T1D with complications exhibit elevated DNA damage
Summary
The mechanisms underlying the development of complications in type 1 diabetes (T1D) are poorly understood. Disease modeling of induced pluripotent stem cells (iPSCs) from patients with longstanding T1D (disease duration ≥ 50 years) with severe (Medalist +C) or absent to mild complications (Medalist −C) revealed impaired growth, reprogramming, and differentiation in Medalist +C. Genomics and proteomics analyses suggested differential regulation of DNA damage checkpoint proteins favoring protection from cellular apoptosis in Medalist −C. In silico analyses showed altered expression patterns of DNA damage checkpoint factors among the Medalist groups to be targets of miR200, whose expression was significantly elevated in Medalist +C serum. Notably, neurons differentiated from Medalist +C iPSCs exhibited enhanced susceptibility to genotoxic stress that worsened upon miR200 overexpression. Furthermore, knockdown of miR200 in Medalist +C fibroblasts and iPSCs rescued checkpoint protein expression and reduced DNA damage. We propose miR200-regulated DNA damage checkpoint pathway as a potential therapeutic target for treating complications of diabetes.
