Tuyển tập các báo cáo nghiên cứu khoa học quốc tế về bệnh thú y đề tài: Effect of dihydrotestosterone on mouse embryonic stem cells exposed to H2O2-induced oxidative stress | J. Vet. Sci. 2008 9 3 247-256 JOURNAL OF Veterinary Science Effect of dihydrotestosterone on mouse embryonic stem cells exposed to HiOi-induced oxidative stress 2 2 2 2 2 Mi Na Lee Sang Hun Lee Min Young Lee Yun Hee Kim Jae Hong Park Jung Min Ryu Seung Pil Yun Yu Jin Lee2 Mi Ok Kim2 Kwangsung Park1 Ho Jae Han2 department of Urology Chonnam National University Medical School Gwangju 501-746 Korea 2Biotherapy Human Resources Center BK 21 College of Veterinary Medicine Chonnam National University Gwangju 500-757 Korea Oxidative stresses induced by reactive oxygen species ROS have been shown to be involved in several physiological and pathophysiological processes such as cell proliferation and differentiation. Steroid hormones can protect cells against apoptosis or induce cell proliferation by several mechanisms. Among androgenic hormones dihydrotestosterone DHT is generated by a 5a - reduction of testosterone. Unlike testosterone DHT cannot be aromatized to estradiol therefore DHT is considered a pure androgenic steroid. This study was conducted to examine the effect of DHT 10-7 M on H2O2 10-3 M -induced injuries in mouse embryonic stem ES cells. H2O2 induced ROS generation and increased lipid peroxide formation and DNA fragmentation. These effects of H2O2 were inhibited by pretreatment with DHT. H2O2 also increased the phosphorylation of p38 MAPK SAPK JNK and nuclear factor kappa B NF-kB but DHT blocked these effects. Moreover H2O2 decreased DNA synthesis and the levels of cell cycle regulatory proteins cyclin D1 cyclin E cyclin-dependent kinase CDK 2 and cDK 4 . These effects of H2O2 were inhibited by pretreatment with DHT. In conclusion DHT may partially prevent H2O2-induced cell injury through inhibition of ROS and ROS-induced activation of p38 MaPK SAPK JNK and NF-k B in mouse ES cells. Keywords DHT dihydrotestosterone H2O2 mouse ES cell oxidative stress Introduction Although oxygen is required for aerobic life it may be toxic under certain conditions 1 .
