Effect of sodium fluoride on myocardial damage by regulating apoptosis through JNK signaling pathway
- VernacularTitle:氟化钠通过JNK通路调控细胞凋亡致心肌细胞损伤的作用研究
- Author:
Liting CAO
1
,
2
;
Wei XU
3
;
Baohui MA
3
Author Information
- Publication Type:Experiment
- Keywords: sodium fluoride; H9c2 cardiomyocyte; JNK signaling pathway; apoptosis; oxidative stress; reactive oxygen species
- From: Journal of Environmental and Occupational Medicine 2023;40(2):224-229
- CountryChina
- Language:Chinese
- Abstract: Background It has been found that fluoride may cause cardiomyocyte damage. c-Jun N-terminal kinases (JNK) signaling pathway plays an important role in apoptosis, but its role in fluorosis-induced cardiomyocyte damage is still unknown yet. Objective To explore the toxic effect of sodium fluoride (NaF) on H9c2 cardiomyocytes of rats and whether NaF affects cardiomyocyte apoptosis through the JNK signaling pathway. Methods According to the concentrations of sodium fluoride and whether sp600125 (JNK inhibitor) was added, cardiomyocytes of rats were divided into six groups, including control group, SP600125 group (SP group), 0.24, 0.48, and 0.96 mmol·L−1 NaF groups, and 0.96 mmol·L−1 NaF+SP600125 group (NaF+SP group). Cardiomyocytes exposed to NaF for 24 h were observed using a fluorescence inverted microscope. The changes of cell viability at 24, 48, and 72 h after the treatment were detected by CCK-8 method. The levels of reactive oxygen species (ROS) at 24 h after the treatment in H9c2 cardiomyocytes were determined by fluorescent probe method. The expression levels of Bcl-2, Bax, Caspase-3, and JNK mRNA at 24 h after the treatment were detected by real-time PCR. The protein expression levels of Bcl-2, Bax, Caspase-3, and p-JNK at 24 h after the treatment were detected by Western blotting. Results Compared with the control group, after being exposed to 0.48 and 0.96 mmol·L−1 NaF for 24 h, the cell growth density decreased. With the increase of NaF concentration, rounded cells and some suspended dead cells appeared. At 24h after exposure to NaF, the cell viability of the 0.48 and 0.96 mmol·L−1 NaF groups decreased compared with the control group (P<0.05). At 48h and 72h after exposure to NaF, the cell viability levels of the NaF treated groups were significantly lower than that of the control group (P<0.05). After NaF exposure for 24 h, compared with the control group, the intracellular ROS levels were increased (P<0.05); the mRNA expression levels of Bcl-2 were decreased to varying degrees, especially in the 0.48 and 0.96 mmol·L−1 NaF groups (P<0.05); the mRNA expression levels of Bax, Caspase-3, and JNK were increased (P<0.05); the protein expression levels of Bcl-2 were reduced (P<0.05); the protein expression levels of Bax, Caspase-3, and p-JNK were elevated (P<0.05). Compared with the 0.96 mmol·L−1 NaF group, the cell viability of the NaF+SP group was increased, the intracellular ROS level was decreased, the mRNA expression levels of Bax, Caspase-3, and JNK were decreased, the protein expression level of Bcl-2 was increased, and the protein expression levels of Bax, Caspase-3, and p-JNK were decreased (P<0.05); the expression level of Bcl-2 mRNA had a rising trend but showed no statistical significance (P>0.05). Conclusion Cardiomyocyte damage after excessive fluoride exposure may result from fluoride inducing excessive ROS production in cardiomyocytes, which may activate the JNK signaling pathway and induce cardiomyocyte apoptosis.
