Molecular Mechanisms Underlying TNFα-Induced Mitochondrial Biogenesis in Human Airway Smooth Muscle

• Published in: International journal of molecular sciences 2023-03, Vol.24 (6), p.5788
• Main Authors: Dasgupta, Debanjali, Mahadev Bhat, Sanjana, Price, Alexis L, Delmotte, Philippe, Sieck, Gary C
• Format: Article
• Language: English
• Subjects: airway inflammation; Asthma; ATF1; Binding sites; Biosynthesis; Chronic obstructive pulmonary disease; Confocal microscopy; Copy number; CREB; Cyclic AMP response element-binding protein; Deprivation; DNA, Mitochondrial - genetics; Gene expression; Genes; Genomes; Humans; Inflammation; Laboratories; Mitochondria; Mitochondria - metabolism; mitochondrial biogenesis; Mitochondrial DNA; Mitochondrial Proteins - genetics; Mitochondrial Proteins - metabolism; Molecular modelling; Muscle, Smooth - metabolism; Organelle Biogenesis; Patients; Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha - genetics; Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha - metabolism; PGC1α; Phosphorylation; Protein expression; Proteins; Respiratory tract; Respiratory tract diseases; REST protein; Scientific equipment and supplies industry; Smooth muscle; TNFα; Transcription activation; Transcription factors; Tumor necrosis factor; Tumor Necrosis Factor-alpha - metabolism; Tumor Necrosis Factor-alpha - pharmacology; Tumor necrosis factor-α
• ISSN: 1422-0067; 1661-6596; 1422-0067
• DOI: 10.3390/ijms24065788

Proinflammatory cytokines such as TNFα mediate airway inflammation. Previously, we showed that TNFα increases mitochondrial biogenesis in human ASM (hASM) cells, which is associated with increased PGC1α expression. We hypothesized that TNFα induces CREB and ATF1 phosphorylation (pCREB and pATF1 ), which transcriptionally co-activate PGC1α expression. Primary hASM cells were dissociated from bronchiolar tissue obtained from patients undergoing lung resection, cultured (one-three passages), and then differentiated by serum deprivation (48 h). hASM cells from the same patient were divided into two groups: TNFα (20 ng/mL) treated for 6 h and untreated controls. Mitochondria were labeled using MitoTracker green and imaged using 3D confocal microscopy to determine mitochondrial volume density. Mitochondrial biogenesis was assessed based on relative mitochondrial DNA (mtDNA) copy number determined by quantitative real-time PCR (qPCR). Gene and/or protein expression of pCREB , pATF1 , PCG1α, and downstream signaling molecules (NRFs, TFAM) that regulate transcription and replication of the mitochondrial genome, were determined by qPCR and/or Western blot. TNFα increased mitochondrial volume density and mitochondrial biogenesis in hASM cells, which was associated with an increase in pCREB , pATF1 and PCG1α expression, with downstream transcriptional activation of , and We conclude that TNFα increases mitochondrial volume density in hASM cells via a pCREB /pATF1 /PCG1α-mediated pathway.