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Biology subjects

Königshoff, M.

Publications and source records attributed to Königshoff, M..

4 recordsLinked to original sources

Lifespan Analysis of the Lung Epithelium Reveals Inflammatory Reprogramming and Regenerative Decline

Aging is a major risk factor for chronic lung diseases, associated with chronic low-grade inflammation (inflammaging) and impaired epithelial regeneration. How epithelial-intrinsic aging intersects with inflammaging across the lifespan remains poorly understood. Here, we systematically analyzed lung epithelial cells from neonatal, young adult, and aged mice to define age-dependent changes in regenerative capacity. RNA sequencing revealed lifespan-associated shifts characterized by early repression of developmental and WNT/{beta}-catenin programs and progressive activation of DNA damage, inflammation, and senescence signatures. Functionally, neonatal epithelial cells exhibited markedly enhanced organoid-forming capacity compared with young and aged cells. Aged organoids maintained a pro-inflammatory secretory profile indicative of cell-intrinsic inflammaging, and transfer of the aged secretome or TNF- to young cultures significantly impaired regeneration. Comparison of freshly isolated cells and long-term organoid cultures revealed sustained repression of regenerative pathways with age, consistent with stable epigenetic imprinting. Pharmacological inhibition of DNA methylation and WNT signalling partially restored regenerative capacity in adult organoids. Together, these findings identify epigenetic reprogramming and epithelial-intrinsic inflammaging as key determinants of age-dependent regenerative decline.

cell biology↗

Alveolar Epithelial Cell Loss of the Mitochondrial Regulator TFAM Drives Progressive Lung Fibrosis

Idiopathic pulmonary fibrosis (IPF) is characterized by failed alveolar epithelial repair and progressive fibrotic remodeling. Although aberrant reprogramming of alveolar type 2 (AT2) cells and accumulation of transitional AT2 states are increasing recognized as central features of IPF, the epithelial-intrinsic mechanisms that initiate these pathogenic states remain incompletely understood. Here, we identify mitochondrial transcription factor A (TFAM), a regulator of mitochondrial DNA maintenance, as a critical regulator of AT2 cell homeostasis. TFAM expression was reduced in AT2 cells from human IPF lungs. Inducible AT2 cell-specific Tfam deletion in mice caused spontaneous fibrotic remodeling and increased susceptibility to bleomycin-induced lung injury. TFAM-deficient AT2 cells acquired KRT8+ transitional and p21+ senescence-associated features before the onset of fibrotic transformation, accompanied by impaired oxidative phosphorylation, redox imbalance, mitochondrial superoxide accumulation, repression of mtDNA-encoded respiratory genes, and disrupted mitochondrial ultrastructure. TFAM-deficient AT2 cells developed a profibrotic secretory program that promoted extracellular matrix deposition and fibroblast activation. We further identified insulin-like growth factor-binding protein 2 (IGFBP2) as a secreted mediator induced in TFAM-deficient AT2 cells. IGFBP2 was elevated in AT2 cells in human IPF lung tissue and bronchoalveolar lavage fluid (BALF) from patients with IPF. IGFBP2 was detected in supernatants from fibrotic human precision-cut lung slices (hPCLS). IGFBP2 neutralization attenuated profibrotic remodeling in fibrotic hPCLS. Collectively, our findings identify TFAM-dependent mitochondrial homeostasis as an epithelial checkpoint linking AT2 cell-state stability to impaired epithelial-mesenchymal crosstalk driving pulmonary fibrosis.

pathology↗

Fibroblasts-derived extracellular vesicles contain SFRP1 and mediate pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a lethal and chronic lung disease characterized by aberrant intercellular communication, increased extracellular matrix (ECM) deposition, and destruction of functional lung tissue. Extracellular vesicles (EVs) accumulate within the lung in IPF, but their cargo and biological effects remain unclear. Here, we provide the entire the proteome of EV and non-EV fraction during pulmonary fibrosis, and functionally characterize their contribution to fibrosis. EVs were isolated by differential ultracentrifugation of bronchoalveolar lavage fluid (BALF) collected from mice challenged with bleomycin (or PBS as control) or culture supernatants from primary mouse lung fibroblasts. EVs were characterized by nanoparticle tracking analysis, Western Blotting, and quantitative mass spectrometry to define their proteome. EVs accumulation peaked at 14 days post-bleomycin instillation and correlated with decreased lung function. Label-free proteomics identified 107 proteins specific to fibrotic BALF-EVs. This signature was associated with wound healing, extracellular matrix organization, and cell motility. BALF-EVs from fibrotic lungs promoted fibrogenesis, including induction of ECM proteins in precision cut lung slices ex vivo and impaired alveolar epithelial cell stem cell function. Deconvolution using single cell RNA sequencing datasets revealed that fibroblasts are the major cellular source of BALF-EVs. EVs from fibroblasts were significantly enriched in Secreted Frizzled Related Protein 1 (SFRP1). In the lungs of patients with IPF, SFRP1 was significantly increased in mesenchymal cells. Sfrp1 deficiency reduced the ability of fibroblast-derived EVs to potentiate bleomycin-induced lung fibrosis in vivo and led to a reduction in fibrosis marker gene expression. In sum, EVs carry specific protein cargos, such as SFRP1, to contribute to organ remodeling during fibrosis. Our data identified EVs transporting SFRP1 as a potential therapeutic target for IPF.

cell biology↗

A transcriptomics-guided drug target discovery strategy identifies novel receptor ligands for lung regeneration

Currently, there is no pharmacological treatment targeting defective tissue repair in chronic disease. Here we utilized a transcriptomics-guided drug target discovery strategy using gene signatures of smoking-associated chronic obstructive pulmonary disease (COPD) and from mice chronically exposed to cigarette smoke, identifying druggable targets expressed in alveolar epithelial progenitors of which we screened the function in lung organoids. We found several drug targets with regenerative potential of which EP and IP prostanoid receptor ligands had the most significant therapeutic potential in restoring cigarette smoke-induced defects in alveolar epithelial progenitors in vitro and in vivo. Mechanistically, we discovered by using scRNA-sequencing analysis that circadian clock and cell cycle/apoptosis signaling pathways were enriched in alveolar epithelial progenitor cells in COPD patients and in a relevant model of COPD, which was prevented by PGE2 or PGI2 mimetics. Conclusively, specific targeting of EP and IP receptors offers therapeutic potential for injury to repair in COPD.

pharmacology and toxicology↗