Role of mitochondrial biogenesis in rat model of coal workers' pneumoconiosis based on PGC-1α-NRF1-TFAM signaling pathway
- VernacularTitle:基于PGC-1α-NRF1-TFAM信号通路探究线粒体生物发生在煤工尘肺大鼠模型中的作用
- Author:
Mei ZHANG
1
;
Xiaoqiang HAN
2
;
Lulu LIU
1
;
Yan WANG
1
;
Xin MA
1
;
Yu XIONG
1
;
Huifang YANG
1
;
Na ZHANG
1
Author Information
- Publication Type:Selectedarticle
- Keywords: coal dust; fibrosis; mitochondrial biogenesis; peroxisome proliferator-activated receptor gamma coactivator 1-alpha
- From: Journal of Environmental and Occupational Medicine 2025;42(12):1429-1437
- CountryChina
- Language:Chinese
- Abstract: Background Mitochondrial biogenesis is pivotal in coal workers' pneumoconiosis fibrosis, yet the role of the peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α)-nuclear respiratory factor 1 (NRF1)-mitochondrial transcription factor A (TFAM) pathway inmitochondrial biogenesis remains elusive, warranting further investigation. Objective To elucidate the role of the PGC-1α-NRF1-TFAM pathway in mitochondrial biogenesis in a rat coal workers' pneumoconiosis model through in vivo and in vitro experiments. Methods (1)n vivo: twelve SPF male SD rats (200-220 g) were randomized into a control group and a coal dust group (n=6 per group). After acclimatization, the coal dust group received 1 mL 50 mg·mL−1 coal dust suspension via intratracheal instillation; the controls received saline. Lung tissues were harvested after two months for histopathology [HE, Masson, and transmission electron microscopy (TEM) ], protein and mRNA analysis, and mitochondrial DNA (mtDNA) quantification by quantitative real-time polymerase chain reaction (qPCR). (2) In vitro: rat lung type II epithelial cells (RLE-6TN) cells were exposed to coal dust (50, 100, 200, and 400 mg·L−1, 24 h). CCK-8 assay determined optimal doses. Ultrastructural changes were analyzed by TEM. Cells were transfected with OE-PGC-1α (PGC-1α overexpression) or shRNA-PGC-1α plasmids (PGC-1α knockdown), and the transfection efficiency was determined by reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR). The expression levels of alpah-smooth muscle actin (α-SMA), citrate synthase (CS), PGC-1α, NRF1, TFAM, and fibronectin (Fn) proteins and their corresponding mRNA were detected using Western blot and RT-qPCR, respectively. The relative content of mtDNA was determined by qPCR. Results In vivo: the control group lung samples exhibited soft, pink parenchyma, while the coal dust-exposed lungs showed blackened surfaces with soft texture. The histopathological evaluation revealed intact alveolar walls in the controls versus structural destruction, micro-nodules, and fibrotic areas in the coal dust group. After Masson staining, coal dust deposits were found surrounded by blue collagen fibers in the exposed lungs, but absent in the controls. The coal dust group displayed significant upregulation of fibrotic marker α-SMA and downregulation of mitochondrial biogenesis markers (CS, PGC-1α, NRF1, TFAM) and mtDNA compared to the controls (P<0.05). In vitro: coal dust exposure reduced cell density and induced morphological alterations. TEM revealed evenly distributed normal mitochondria in controls versus mitochondrial swelling, disrupted cristae, and reduced numbers in exposed cells. The mitochondrial biogenesis markers were elevated in the coal dust + OE-PGC-1α group compared to the coal dust + OE-NC group (P<0.05); in contrast, they were decreased in the coal dust + shRNA-PGC-1α group compared to the coal dust + shRNA-NC group (P<0.05). Compared to the control group, the expression levels of the fibrosis marker α-SMA mRNA and protein were increased in the coal dust group (P<0.05). Overexpression of PGC-1α reduced α-SMA expression, while downregulation of PGC-1α increased its expression (P<0.05). Conclusion Coal dust exposure induces mitochondrial dysfunction and pulmonary fibrosis in vivo and in vitro via the PGC-1α-NRF1-TFAM pathway dysregulation. Targeting this pathway may mitigate coal dust-induced fibrosis by restoring mitochondrial biogenesis.
