Exogenous H2S contributes to recovery of ischemic post-conditioning-induced cardioprotection by decrease of ROS level via down-regulation of NF-κB and JAK2-STAT3 pathways in the aging cardiomyocytes.
BACKGROUND
Hydrogen sulfide (H2S), a third member of gasotransmitter family along with nitric oxide and carbon monoxide, generated from mainly catalyzed by cystathionine-lyase, possesses important functions in the cardiovascular system. Ischemic post-conditioning (PC) strongly protects against the hypoxia/reoxygenation (H/R)-induced injury and apoptosis of cardiomyocytes. However, PC protection is ineffective in the aging cardiomyocytes. Whether H2S restores PC-induced cardioprotection by decrease of reactive oxygen species (ROS) level in the aging cardiomyocytes is unknown.


METHODS
The aging cardiomyocytes were induced by treatment of primary cultures of neonatal cardiomyocytes using d-galactose and were exposed to H/R and PC protocols. Cell viability was observed by CCK-8 kit. Apoptosis was detected by Hoechst 33342 staining and flow cytometry. ROS level was analyzed using spectrofluorimeter. Related protein expressions were detected through Western blot.


RESULTS
Treatment of NaHS (a H2S donor) protected against H/R-induced apoptosis, cell damage, the expression of cleaved caspase-3 and cleaved caspase-9, the release of cytochrome c (Cyt c). The supplementation of NaHS also decreased the activity of LDH and CK, MDA contents, ROS levels and the phosphorylation of IκBα, NF-κB, JNK2 and STAT3, and increased cell viability, the expression of Bcl-2, the activity of SOD, CAT and GSH-PX. PC alone did not provide cardioprotection in H/R-treated aging cardiomyocytes, which was significantly restored by the addition of NaHS. The beneficial role of NaHS was similar to the supply of N-acetyl-cysteine (NAC, an inhibitor of ROS), Ammonium pyrrolidinedithiocarbamate (PDTC, an inhibitor of NF-κB) and AG 490 (an inhibitor of JNK2), respectively, during PC.


CONCLUSIONS
Our results suggest that exogenous H2S contributes to recovery of PC-induced cardioprotection by decrease of ROS level via down-regulation of NF-κB and JAK2/STAT3 pathways in the aging cardiomyocytes.
Department of Pathophysiology, Harbin Medical University, Baojian Road, Harbin, 150081 China.|The Key Laboratory of Cardiovascular Medicine Research, Harbin Medical University, Ministry of Education, Harbin, China.
Lina
L
Li
Department of Pathophysiology, Harbin Medical University, Baojian Road, Harbin, 150081 China.|The Key Laboratory of Cardiovascular Medicine Research, Harbin Medical University, Ministry of Education, Harbin, China.
Meixiu
M
Li
Department of Pathophysiology, Harbin Medical University, Baojian Road, Harbin, 150081 China.|The Key Laboratory of Cardiovascular Medicine Research, Harbin Medical University, Ministry of Education, Harbin, China.
Youyou
Y
Li
Department of Pathophysiology, Harbin Medical University, Baojian Road, Harbin, 150081 China.|The Key Laboratory of Cardiovascular Medicine Research, Harbin Medical University, Ministry of Education, Harbin, China.
Weiming
W
Sun
Department of Pathophysiology, Harbin Medical University, Baojian Road, Harbin, 150081 China.|The Key Laboratory of Cardiovascular Medicine Research, Harbin Medical University, Ministry of Education, Harbin, China.
Yuehong
Y
Wang
Department of Pathophysiology, Harbin Medical University, Baojian Road, Harbin, 150081 China.|The Key Laboratory of Cardiovascular Medicine Research, Harbin Medical University, Ministry of Education, Harbin, China.
Shuzhi
S
Bai
Department of Pathophysiology, Harbin Medical University, Baojian Road, Harbin, 150081 China.|The Key Laboratory of Cardiovascular Medicine Research, Harbin Medical University, Ministry of Education, Harbin, China.
Hongxia
H
Li
Department of Pathophysiology, Harbin Medical University, Baojian Road, Harbin, 150081 China.|The Key Laboratory of Cardiovascular Medicine Research, Harbin Medical University, Ministry of Education, Harbin, China.
Bo
B
Wu
The Cardiovascular and Metabolic Research Unit, Laurentian University, Sudbury, ON Canada.
Guangdong
G
Yang
The Cardiovascular and Metabolic Research Unit, Laurentian University, Sudbury, ON Canada.
Rui
R
Wang
The Cardiovascular and Metabolic Research Unit, Laurentian University, Sudbury, ON Canada.
Lingyun
L
Wu
Department of Pathophysiology, Harbin Medical University, Baojian Road, Harbin, 150081 China.|The Key Laboratory of Cardiovascular Medicine Research, Harbin Medical University, Ministry of Education, Harbin, China.
Hongzhu
H
Li
Department of Pathophysiology, Harbin Medical University, Baojian Road, Harbin, 150081 China.|The Key Laboratory of Cardiovascular Medicine Research, Harbin Medical University, Ministry of Education, Harbin, China.
Changing
C
Xu
Aging cardiomyocytes; Hydrogen sulfide; Oxidative stress; Post-conditioning