Telomere shortening and DNA damage of embryonic stem cells induced by cigarette smoke

Embryonic stem cells (ESCs) provide a valuable in vitro model for testing toxicity of chemicals and environmental contaminants including cigarette smoke. Mouse ESCs were acutely or chronically exposed to smoke components, cigarette smoke condensate (CSC), or cadmium, an abundant component of CSC, and then evaluated for their self-renewal, apoptosis, DNA damage and telomere function. Acute exposure of ESCs to high dose of CSC or cadmium increased DNA damage and apoptosis. Yet, ESCs exhibited a remarkable capacity to recover following absence of exposure. Chronic exposure of ESCs to low dose of CSC or cadmium resulted in shorter telomeres and DNA damage. Together, acute exposure of ESCs to CSC or cadmium causes immediate cell death and reduces pluripotency, while chronic exposure of ESCs to CSC or cadmium leads to DNA damage and telomere shortening. Notably, a sub-proportion of ESCs during passages is selected to resist to smoke-induced oxidative damage to telomeres.

► We test the cigarette smoke condensate (CSC)-induced telomere damage using embryonic stem cells (ESCs) as an in vitro model. ► Acute exposure to high dose CSC or cadmium causes DNA damage and apoptosis, reducing ESCs proliferation and pluripotency. ► Chronic exposure to low dose CSC or cadmium results in telomere shortening and damage. ► A sub-population of ESCs is selected to resist to smoke-induced telomere damage. ► The ESCs model provides an alternative to understanding of degenerative diseases and cancer induced by cigarette smoke.