NAMPT orchestrates fibroblast cuproptosis and immune crosstalk during IPF progression

<h4>Background</h4>Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive interstitial lung disease characterized by excessive fibroblast activation and extracellular matrix deposition, leading to severe tissue remodeling and poor prognosis. While current treatments offer limited efficacy. Emerging evidence suggests cuproptosis, a novel form of copper-dependent cell death, as a potential mechanism influencing fibroblast survival and fibrogenesis.<h4>Methods</h4>Bulk RNA sequencing (RNA-seq), single-cell RNA sequencing (scRNA-seq), and spatial transcriptomics were utilized to analyze gene expression profiles from IPF patient samples and healthy controls. Differentially expressed genes related to copper regulation and cell death pathways were identified using machine learning algorithms. Immune infiltration was assessed using CIBERSORT, and cell-cell interactions were explored using the CellChat algorithm. Gene set variation analysis (GSVA) and gene set enrichment analysis (GSEA) were employed to explore the role of nicotinamide phosphoribosyltransferase (NAMPT) in cuproptosis and fibrosis-related pathways.<h4>Results</h4>Transcriptomic analysis identified NAMPT as a key hub gene in IPF, with strong positive correlation to cuproptosis. Spatial transcriptomics revealed elevated cuproptosis activity in NAMPT+ fibroblasts localized in fibrotic lesions. Additionally, NAMPT+ fibroblasts exhibited increased crosstalk with M2 macrophages through the C3-ITGB2 complement pathway, implicating NAMPT in promoting fibroblast activation and shaping a pro-fibrotic immune microenvironment.<h4>Conclusion</h4>This study identifies NAMPT as a critical regulator of cuproptosis in IPF fibroblasts and highlights its dual role in fibroblast activation and immune modulation. Targeting NAMPT offers a promising therapeutic strategy for modulating fibroblast behavior, reducing fibrosis, and disrupting the pro-fibrotic cell communication network in IPF.