Cytokinetic Failure-induced Tetraploidy Develops into Aneuploidy, Triggering Skin Aging in Phosphovimentin-deficient Mice

Tetraploidy, a state in which cells have doubled chromosomal sets, is observed in ∼20% of solid tumors and is considered to frequently precede aneuploidy in carcinogenesis. Tetraploidy is also detected during terminal differentiation and represents a hallmark of aging. Most tetraploid cultured cells are arrested by p53 stabilization. However, the fate of tetraploid cells in vivo remains largely unknown. Here, we analyze the ability to repair wounds in the skin of phosphovimentin-deficient ( VIM SA/SA ) mice. Early into wound healing, subcutaneous fibroblasts failed to undergo cytokinesis, resulting in binucleate tetraploidy. Accordingly, the mRNA level of p21 (a p53-responsive gene) was elevated in a VIM SA/SA -specific manner. Disappearance of tetraploidy coincided with an increase in aneuploidy. Thereafter, senescence-related markers were significantly elevated in VIM SA/SA mice. Because our tetraploidy-prone mouse model also exhibited subcutaneous fat loss at the age of 14 months, another premature aging phenotype, our data suggest that following cytokinetic failure, a subset of tetraploid cells enters a new cell cycle and develops into aneuploid cells in vivo , which promote premature aging. Background: The fate of tetraploid cells in vivo remains largely unknown. Results: Tetraploid skin fibroblasts enter a new cell cycle and develop into aneuploid fibroblasts in phosphovimentin-deficient mice. Conclusion: These mice exhibited aging phenotypes in the skin. Significance: Our data suggest a possible causal relationship between tetraploidy and premature aging.