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Idiopathic pulmonary fibrosis (IPF) is an interstitial lung disease characterized by progressive lung scarring and remodeling. Although treatments exist that slow disease progression, IPF is irreversible, and there is no cure. Cellular senescence, a major hallmark of aging, has been implicated in IPF pathogenesis, and mitochondrial dysfunction is increasingly recognized as a driver of senescence. Adenine nucleotide translocases (ANTs) are abundant mitochondrial ATP-ADP transporters critical for regulating cell fate and maintaining mitochondrial function. We sought to determine how alterations in ANTs influence cellular senescence in pulmonary fibrosis. We found that SLC25A4 (solute carrier family 25 member 4) (ANT1) and SLC25A5 (ANT2) expression is reduced in the lungs of patients with IPF, particularly within alveolar type II (AT2) cells, by single-cell RNA sequencing and tissue staining. Loss of ANT1 by siRNA in lung epithelial cells resulted in increased senescence markers such as β-galactosidase and p21, with a reduction in the ratio of nicotinamide adenine dinucleotide to reduced nicotinamide adenine dinucleotide. Bleomycin-treated ANT1 knockdown cells also had increased senescence markers compared with bleomycin-treated control cells. Loss of ANT1 in AT2 cells resulted in a reduction in alveolar organoid growth, with an increase in p21 by staining. Global loss of ANT1 resulted in worse lung fibrosis and increased senescence in the bleomycin- and asbestos-induced mouse models of pulmonary fibrosis. In summary, loss of ANT1 contributes to IPF pathogenesis through mitochondrial dysfunction, increased senescence, and decreased regenerative capacity of AT2 cells, resulting in enhanced lung fibrosis. Modulation of ANTs presents a new therapeutic avenue that may alter cellular senescence pathways and limit pulmonary fibrosis. [ABSTRACT FROM AUTHOR]

This document is an editorial published in Frontiers in Pharmacology titled "Targeting immune cell metabolism in tissue fibrosis." The editorial discusses the role of immune cell metabolism in tissue fibrosis, a condition characterized by the excessive accumulation of extracellular matrix contents in various organs. The editorial highlights four research papers that contribute to our understanding of fibrosis and its immunometabolic processes. These papers explore the potential therapeutic effects of Vitamin E in pulmonary fibrosis, the use of total glucosides of paeony in collagen-induced arthritis, the role of immunometabolism in fibrotic diseases, and the potential of mesenchymal stem cells and their exosomes in systemic sclerosis. The editorial concludes by emphasizing the importance of continued research into the metabolic underpinnings of fibrosis for developing innovative and targeted treatments. [Extracted from the article]