Abstract 12622: The Modeling of Werner Syndrome by Induced Pluripotent Stem Cells

Abstract

Backgrounds: Werner syndrome (WS) is a rare autosomal recessive disorder characterized by premature onset of several aging-associated diseases, such as atherosclerosis, diabetes, cancer, and early death. The aging phenotypes of WS is resembling to those of normal aging. To uncover the mechanism of aging, we tried to model WS by patient-specific induced pluripotent stem cells (iPSCs). WS is caused by mutations in WRN gene belonging to the RecQ DNA helicase family which plays a role in genomic stability. But some of WS phenotypes are hardly explained by genomic instability. Thus, we aimed to model WS by patient-specific iPSCs to elucidate the mechanisms. Methods and Results: We sampled T lymphocytes from a patient with WS. Then we transduced with Yamanaka factors (OCT4, SOX2, KLF4, and MYC) by sendai virus, and iPSC colonies were derived. We confirmed that WS-iPSCs expressed pluripotent markers, could differentiate into all three germ-layer derived tissues, and retained a normal karyotype. We could culture WS-iPSCs over 2 years with pluripotent status. Then, we differentiated WS-iPSCs into fibroblasts-like cells. The proliferation rate of WS-iPSC-derived fibroblast-like cells (WS-iPSC-fibroblasts) was significantly decreased. WS-iPSC-fibroblasts showed a vulnerability to cellular stress and resulted in increased cell population which is positive for senescence associated β-galactosidase activity and γ-H2AX foci. Singled WS-iPSC-fibroblasts showed excessive blebbing of plasma membrane and increased apoptosis compared with control-iPSC-fibroblasts. To compare global gene expression profiles, we performed microarray analysis in WS-iPSC-fibroblasts and control-iPSC-fibroblasts. Interestingly, WS-iPSC-fibroblasts reproduced the global gene expression pattern of physiological aging. To confirm whether the phenotypes of WS-iPSCs are induced by WRN mutation, we generated isogenic control of WS-iPSC (corrected-WS-iPSC) by homologous recombination using helper-dependent adenovirus vector. Corrected-WS-iPSCs lost the aging-associated phenotypes but showed the phenotypes resembling to control-iPSCs. Conclusion: We modeled aging phenotypes by WS-specific iPSCs. This model would be utilize for uncovering the aging mechanisms.