Interferons induce the expression of IFITM1 and IFITM3 and suppress the proliferation of rat neonatal cardiomyocytes

Lau, Samantha Lai‐Yee; Yuen, Man‐Leuk; Kou, Cecy Ying‐Chuck; Au, Ka‐Wing; Zhou, Junwei; Tsui, Stephen Kwok‐Wing

Cardiovascular diseases have been one of the leading killers among the human population worldwide. During the heart development, cardiomyocytes undergo a transition from hyperplastic to hypertrophic growth with an unclear underlying mechanism. In this study, we aim to investigate how interferons differentially stimulate the interferon‐inducible transmembrane (IFITM) family proteins and further be involved in the process of heart development. The expression levels of three IFITM family members, IFITM1, IFITM2, and IFITM3 were investigated during Sprague–Dawley rat myocardial development and differentiation of H9C2 cardiomyocytes. The effects of interferon‐α, ‐β, and ‐γ on DNA synthesis in H9C2 cells were also characterized. Up‐regulation of IFITM1 and IFITM3 were observed during the heart development of Sprague–Dawley rat and the differentiation of H9C2 cells. Moreover, interferon‐α and ‐β induce the expression of IFITM3 while interferon‐γ up‐regulates IFITM1. Finally, interferon‐α and ‐β were demonstrated to inhibit DNA synthesis during H9C2 cell differentiation. Our results indicated interferons are potentially involved in the differentiation and cell proliferation during heart development. J. Cell. Biochem. 113: 841–847, 2012. © 2011 Wiley Periodicals, Inc.