title: Humid heat exposure induced oxidative stress and apoptosis in cardiomyocytes through the angiotensin II signaling pathway.
abstract: Exposure to humid heat stress leads to the initiation of serious physiological dysfunction that may result in heat-related diseases, including heat stroke, heat cramp, heat exhaustion, and even death. Increasing evidences have shown that the humid heat stress-induced dysfunction of the cardiovascular system was accompanied with severe cardiomyocyte injury; however, the precise mechanism of heat stress-induced injury of cardiomyocyte remains unknown. In the present study, we hypothesized that humid heat stress promoted oxidative stress through the activation of angiotensin II (Ang II) in cardiomyocytes. To test our hypothesis, we established mouse models of humid heat stress. Using the animal models, we found that Ang II levels in serum were significantly up-regulated and that the Ang II receptor AT1 was increased in cardiomyocytes. The antioxidant ability in plasma and heart tissues which was detected by the ferric reducing/antioxidant power assay was also decreased with the increased ROS production under humid heat stress, as was the expression of antioxidant genes (SOD2, HO-1, GPx). Furthermore, we demonstrated that the Ang II receptor antagonist, valsartan, effectively relieved oxidative stress, blocked Ang II signaling pathway and suppressed cardiomyocyte apoptosis induced by humid heat stress. In addition, overexpression of antioxidant genes reversed cardiomyocyte apoptosis induced by Ang II. Overall, these results implied that humid heat stress increased oxidative stress and caused apoptosis of cardiomyocytes through the Ang II signaling pathway. Thus, targeting the Ang II signaling pathway may provide a promising approach for the prevention and treatment of cardiovascular diseases caused by humid heat stress.
authors.affiliation: Center of Cardiovascular Surgery, Guangzhou General Hospital of Guangzhou Military Command, Guangzhou, 510010, China.
authors.forename: Xiaowu
authors.initials: X
authors.lastname: Wang
authors.forename: Binbin
authors.initials: B
authors.lastname: Yuan
authors.forename: Wenpeng
authors.initials: W
authors.lastname: Dong
authors.forename: Bo
authors.initials: B
authors.lastname: Yang
authors.forename: Yongchao
authors.initials: Y
authors.lastname: Yang
authors.forename: Xi
authors.initials: X
authors.lastname: Lin
authors.forename: Gu
authors.initials: G
authors.lastname: Gong
mesh_terms: D000804:Angiotensin II / Q000097:blood / Q000378:metabolism*; D047228:Angiotensin II Type 1 Receptor Blockers / Q000494:pharmacology; D000818:Animals; D000975:Antioxidants / Q000378:metabolism / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects; D004195:Disease Models, Animal; D005260:Female; D057809:HEK293 Cells; D018882:Heat Stress Disorders / Q000188:drug therapy / Q000209:etiology / Q000378:metabolism* / Q000473:pathology; D006358:Hot Temperature; D006801:Humans; D006813:Humidity; D008297:Male; D008810:Mice, Inbred C57BL; D032383:Myocytes, Cardiac / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D018384:Oxidative Stress / Q000187:drug effects; D017382:Reactive Oxygen Species / Q000378:metabolism; D044140:Receptor, Angiotensin, Type 1 / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D013997:Time Factors; D000068756:Valsartan / Q000494:pharmacology
chemical_list: D047228:Angiotensin II Type 1 Receptor Blockers; D000975:Antioxidants; D017382:Reactive Oxygen Species; D044140:Receptor, Angiotensin, Type 1; D000804:Angiotensin II; D000068756:Valsartan