Isoforskolin targets ADCY7 to restore mitochondrial function in COPD-associated macrophages.

BACKGROUND

Mitochondrial dysfunction in alveolar macrophages (AMs) drives chronic airway inflammation in chronic obstructive pulmonary disease (COPD). Adenylyl cyclase 7 (ADCY7) is a key enzyme in cAMP signaling, but its role in macrophage mitochondrial dysfunction and immune regulation in COPD remains unclear. Isoforskolin (ISOF), a bioactive natural product from Coleus forskohlii, has known anti-inflammatory properties, yet whether it improves macrophage mitochondrial function via ADCY7 is unknown.

OBJECTIVE

To investigate whether ISOF acts through ADCY7 to restore mitochondrial function and correct the dysfunctional phenotype of a COPD-enriched ADCY7+CCL4+ macrophage subpopulation.

METHODS

ADCY7 expression was measured in AMs from COPD patients. Single-cell and bulk transcriptomics (GSE171541, GSE57148) were used to identify ADCY7+ macrophage subpopulations. Network pharmacology, molecular docking and molecular dynamics simulations predicted the ISOF-ADCY7 interaction. A cigarette smoke extract (CSE)-induced THP-1-derived macrophage model and a cigarette smoke plus lipopolysaccharide (LPS)-induced mouse COPD model were employed, combined with ADCY7 silencing and rescue experiments. Mitochondrial function was assessed by Seahorse analysis, transmission electron microscopy, mtROS, mtDNA copy number, ATP, JC-1 and calcium assays.

RESULTS

ADCY7 expression was significantly downregulated in AMs from COPD patients and negatively correlated with lung function. Single-cell analysis identified a COPD-enriched ADCY7+CCL4+ macrophage subpopulation exhibiting a transitional inflammatory-repair phenotype. Molecular docking and dynamics simulations predicted stable binding of ISOF to ADCY7 (binding energy -5.9 kcal/mol). In vitro and in vivo experiments confirmed that ISOF upregulated ADCY7 expression. In vivo, ISOF improved pulmonary function, reduced collagen deposition and inflammatory cytokines (TNF-α, IL-1β, IL-6), and increased cAMP and ATP levels in mouse AMs. In vitro, ISOF reversed CSE-induced mitochondrial ultrastructural damage, calcium overload, mtROS overproduction, loss of mitochondrial membrane potential and respiratory chain deficiency.

CONCLUSION

ISOF alleviates COPD by modulating ADCY7-dependent pathways to improve macrophage mitochondrial function and reverse the functional imbalance of the ADCY7+CCL4+ macrophage subpopulation.</font> These findings position ISOF as a promising immunometabolic and mitochondrial-targeted candidate for COPD therapy.