The mechanistic role of oxidative stress in cigarette smoke-induced cardiac stem cell dysfunction and prevention by ascorbic acid.

Cigarette smoking causes a vast array of diseases including cardiovascular diseases. Our laboratory focuses on investigating cigarette smoke (CS)-induced cardiovascular malfunction and the responsible mechanisms utilizing the model, c-kit-positive cardiac stem cells (CSCs). The main objective of our study is to investigate whether CS extracts (CSEs) cause impairment of CSC functions via oxidative damage. We hypothesized that CSE, via oxidative modifications of CSC proteins and antioxidant enzymes, can modulate CSC functions and these modifications can be attenuated by ascorbate treatment. Our specific aims are (1) to investigate CSE-induced oxidative modification of CSC proteins via carbonylation, and prevention by ascorbic acid; (2) to investigate CSE-induced oxidative modification of antioxidant enzymes and ascorbic acid-mediated modulations; and (3) to investigate CSE-induced changes in CSC functions and protection by ascorbic acid. CSCs were cultured, and the aqueous extracts of CSE were prepared. CSE-induced modulations of CSC viability, oxidative modification of proteins, and antioxidant enzyme activities were detected using standard assays including Apostain, bromodeoxyuridine, and Oxiblot. CSE caused oxidative modification of CSC proteins, changed antioxidant enzyme levels, attenuated CSC proliferation, and accelerated CSC apoptosis. Ascorbic acid prevented CSE-induced CSC malfunctions, and ascorbic acid therapy might be useful in smoker CSC recipients and to condition CSCs prior to the transplant in the future. Cardiac stem cell therapy is currently undergoing in clinical trials.

Cigarette smoke adversely affects functions and cell membrane integrity in c-kit+ cardiac stem cells.

Cigarette smoking is a major risk factor for numerous diseases including cardiovascular diseases. Exposure to cigarette smoke (CS) leads to increased cardiovascular risk, myocardial injury, and mortality. Stem cell therapy is one of the promising therapeutic options available to treat myocardial injuries. Understanding the impact of cigarette smoke extract (CSE) on stem cell function would be valuable in determining the risk passed on during transplant. In this study, the impact of CSE on cardiac stem cell (CSC) functions was investigated using c-kit+ rat cardiac stem cells as the experimental model. Here, we hypothesized that CSE attenuates CSC membrane integrity, causes cytotoxicity, and affects many CSC functions via multiple mechanisms including modulation of extracellular stress-regulated kinase (ERK) (44/42) signaling and oxidative stress. The effects of CSE on CSCs were examined in vitro. Based on a published method, CSE was prepared. CSE-induced ERK signaling was detected by western blotting. CSE-induced modulation of catalase activity was also measured. Functional modulations due to CSE were examined via several methods including Apostain, BrdU, and LDH assays. In agreement with the CSE-induced activation of ERK, CSE-induced reduction in viability, migration, and increase in both cytotoxicity and para-cellular permeability were observed in CSCs. These results suggest that CSE impaired CSC responses that contribute to decreased ability of CSC to respond to stress or injury leading to exacerbation of the damage. Our findings will contribute to the understanding of the discipline and might contribute to the development of stem cell therapy approaches in the future.