Role and mechanism of SIRT3 in arsenic-induced fibrotic responses in HELF cells
- VernacularTitle:SIRT3在砷暴露诱导HELF细胞纤维化中的作用和机制
- Author:
Jinge WU
1
;
Wen SHI
1
;
Li WANG
1
;
Xuemin SHI
1
;
Yuhang ZHAO
1
Author Information
- Publication Type:Experiment
- Keywords: arsenic exposure; fibrosis; glycolysis; sirtuin 3; hypoxia-inducible factor 1-alpha
- From: Journal of Environmental and Occupational Medicine 2026;43(8):1018-1026
- CountryChina
- Language:Chinese
- Abstract: Background Arsenic exposure has been implicated as an important environmental contributor to pulmonary fibrosis, the pathogenesis of which is closely associated with abnormal activation of pulmonary fibroblasts. However, the specific mechanism remain incompletely understood. Objective To examine sirtuin 3 (SIRT3) expression during arsenite-induced fibrotic responses in lung fibroblasts, and to investigate its effects on aerobic glycolysis and profibrotic progression, as well as its underlying mechanisms. Methods Human embryonic lung fibroblasts (HELF) were treated with sodium arsenite (NaAsO2) at different concentrations (0, 2.5, 5, 10, 20, 40, and 80 μmol·L−1) for 48 h. Cell viability was assessed, and lactate and hydroxyproline (HYP) levels were measured as indicator of glycolytic activity and fibrotic response. Western blot and quantitative polymerase chain reaction (q-PCR) were used to determine the protein and mRNA expression levels of SIRT3, hypoxia-inducible factor 1-alpha (HIF-1α), fibrosis-related genes [Collagen type Ⅰ (Collagen-Ⅰ), and α-smooth muscle actin (α-SMA)], and glycolysis-related genes [pyruvate kinase M2 (PKM2), hexokinase 2 (HK2), and lactate dehydrogenase A (LDHA)]. Results Based on the cell viability results, the NaAsO2 concentrations of 2.5, 5, and 10 μmol·L−1 for 48 h were selected for subsequent experiments. Compared with the control group, HYP levels were significantly increased in the 2.5, 5, and 10 μmol·L−1 NaAsO2 exposure groups (P <0.05). The protein and mRNA expression levels of HIF-1α, glycolysis-related genes (PKM2, HK2, and LDHA) and fibrosis-related genes (Collagen-Ⅰ, and α-SMA) were significantly upregulated, whereas SIRT3 protein and mRNA expression levels were significantly down-regulated, in the NaAsO2 treated groups compared with the control group (P<0.05). SIRT3 overexpression significantly reduced HYP levels and downregulated the protein and mRNA expression levels of HIF-1α, glycolysis-related genes (PKM2, HK2, and LDHA), fibrosis-related genes (Collagen-Ⅰ, and α-SMA) compared with the NaAsO2 + negative control group (P<0.05). Similarly, HIF-1α knockdown significantly decreased HYP levels and downregulated the protein and mRNA expression levels of glycolysis-related genes (PKM2, HK2, and LDHA) and fibrosis-related genes (Collagen-Ⅰ, and α-SMA) compared with the NaAsO2 + negative control group (P<0.05). In contrast, simultaneous overexpression of SIRT3 and HIF-1α abolished the inhibitory effects of SIRT3 overexporession, as HYP levels and the expression of glycolysis- and fibrosis-related markers showed no statistically significant differences compared with the NaAsO2 + negative control group (P>0.05). Conclusion NaAsO2 exposure could induce profibrotic and glycolysis-related responses in HELF cells, accompanied by SIRT3 downregulation and HIF-1α activation. These findings suggest that the SIRT3/HIF-1α regulatory axis may be a potential target for preventing or attenuating arsenic exposure-related pulmonary fibrotic responses.
