-
Views
-
Cite
Cite
Wei Song, Xiangru Lu, Qingping Feng, Tumor necrosis factor-α induces apoptosis via inducible nitric oxide synthase in neonatal mouse cardiomyocytes, Cardiovascular Research, Volume 45, Issue 3, February 2000, Pages 595–602, https://doi.org/10.1016/S0008-6363(99)00395-8
Close - Share Icon Share
Abstract
Objective: It has been demonstrated that tumor necrosis factor-α (TNFα) induces apoptosis in cardiac myocytes. However, its mechanism of action is still not well understood. In the present study, we hypothesized that TNFα induces myocardial apoptosis by induction of inducible nitric oxide synthase (iNOS). Methods: Neonatal cardiac myocytes were isolated from iNOS (−/−) mutant and C57BL6 wild type mice. Cells were cultured for 3 days before treatment with an NO donor or TNFα. Following treatment with S-nitroso-N-acetyl-penicillamine (SNAP) or TNF-α, cells were tested for apoptosis by terminal deoxynucleotidyl transfer-mediated end labeling (TUNEL) staining and cell death detection ELISA. NO production was measured by nitrite concentration in the culture medium. Cardiomyocyte expression of iNOS and TNF type 1 receptor (TNFR1) mRNA was determined by reverse transcriptase-polymerase chain reaction (RT-PCR). Results: SNAP (0.01–100 μM) induced apoptosis of cardiac myocytes in a concentration-dependent manner in the wild type mice (n=5, P<0.01). TNFR1 mRNA was expressed in neonatal cardiomyocytes from both wild type and iNOS (−/−) mutant mice. TNFα induced a concentration-dependent increase in iNOS mRNA expression and nitrite production as well as significant apoptosis of cardiomyocytes in the wild type mice (n=4, P<0.01). However, without iNOS expression, the apoptotic effects of TNF-α were significantly attenuated in cardiomyocytes from iNOS (−/−) mutant mice (n=4, P<0.05). Conclusion: TNFα induces apoptosis via iNOS expression and NO production in neonatal mouse cardiomyocytes.
