Rong Luo1, Xuepin Chen2, Huihui Ma3, Chao Yao3, Mingjiang Liu3, Jianhong Tao3, Xiaoping Li4. 1. Temperature and Inflammation Research Center, Key Laboratory of Colleges and Universities in Sichuan Province, Chengdu Medical College, 610500, China. 2. Zunyi Medical University, Zunyi, Guizhou 563000, China; Department of Cardiology, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Chengdu 610072, China. 3. Department of Cardiology, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Chengdu 610072, China. 4. Zunyi Medical University, Zunyi, Guizhou 563000, China; Department of Cardiology, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Chengdu 610072, China. Electronic address: lixiaoping0119@163.com.
Abstract
AIMS: To explore the potential mechanism that the role of the Akt/eNOS/NO pathway in calpain-induced caspase-3 and NF-κB activation during septic apoptosis. MAIN METHODS: Septic rats were stimulated by LPS (8 mg/kg, i.p.). Myocardial calpain, caspase-3, NO, TNF-α and IL-1β levels were detected by ELISA. The levels of Akt/p-Akt, eNOS/p-eNOS, iNOS proteins and number of apoptotic cells were evaluated by immunohistochemistry, western blot and TUNEL method. KEY FINDINGS: Compared with sham, LPS treatment resulted in 4.1-fold and 1.8-fold increases in myocardial calpain activity and caspase-3 activation, respectively, and a significant increase (6.8-fold) in apoptotic cardiomyocytes was observed. The administration of calpain inhibitors (calpain inhibitor-IV, PD150606 and PD151746) showed that p-Akt and p-eNOS protein levels were correlated with the levels of LPS-induced myocardial calpain and caspase-3 activity. In addition, the quantity of p-Akt protein and NO content were markedly attenuated by wortmannin, a phosphoinositide 3-kinase (PI3K) inhibitor. Pretreatment with L-NAME, an NOS inhibitor, induced a decrease in p-eNOS proteins and apoptosis in myocardial tissues, while iNOS proteins were strongly increased in septic rats. SIGNIFICANCE: This study suggests that the Akt/eNOS/NO pathway might lead to a novel pharmacological therapy for cardiomyocytes apoptosis in sepsis.
AIMS: To explore the potential mechanism that the role of the Akt/eNOS/NO pathway in calpain-induced caspase-3 and NF-κB activation during septic apoptosis. MAIN METHODS: Septic rats were stimulated by LPS (8 mg/kg, i.p.). Myocardial calpain, caspase-3, NO, TNF-α and IL-1β levels were detected by ELISA. The levels of Akt/p-Akt, eNOS/p-eNOS, iNOS proteins and number of apoptotic cells were evaluated by immunohistochemistry, western blot and TUNEL method. KEY FINDINGS: Compared with sham, LPS treatment resulted in 4.1-fold and 1.8-fold increases in myocardial calpain activity and caspase-3 activation, respectively, and a significant increase (6.8-fold) in apoptotic cardiomyocytes was observed. The administration of calpain inhibitors (calpain inhibitor-IV, PD150606 and PD151746) showed that p-Akt and p-eNOS protein levels were correlated with the levels of LPS-induced myocardial calpain and caspase-3 activity. In addition, the quantity of p-Akt protein and NO content were markedly attenuated by wortmannin, a phosphoinositide 3-kinase (PI3K) inhibitor. Pretreatment with L-NAME, an NOS inhibitor, induced a decrease in p-eNOS proteins and apoptosis in myocardial tissues, while iNOS proteins were strongly increased in septic rats. SIGNIFICANCE: This study suggests that the Akt/eNOS/NO pathway might lead to a novel pharmacological therapy for cardiomyocytes apoptosis in sepsis.
Authors: Priscila Ausina; Jessica R Branco; Thainá M Demaria; Amanda M Esteves; João Gabriel B Leandro; Alan C Ochioni; Ana Paula M Mendonça; Fernando L Palhano; Marcus F Oliveira; Wassim Abou-Kheir; Mauro Sola-Penna; Patricia Zancan Journal: Sci Rep Date: 2020-11-12 Impact factor: 4.379