Berberine Suppresses Pathogenic Fungus Aspergillus fumigatus Hyphal Growth via Mitochondrial Fragmentation-Induced ROS Elevation and Hog1-MAPK Activation.

Berberine (BER), a natural isoquinoline alkaloid, exhibits broad-spectrum antifungal activity, yet its mechanism against Aspergillus fumigatus─a leading cause of invasive fungal infections─remains poorly understood. Here, we aim to unveil the mechanism of BER against the pathogenicity of A. fumigatus through mitochondrial dynamics and related pathways. In vitro assays revealed that berberine treatment triggered mitochondrial fragmentation, resulting in reactive oxygen species (ROS) overaccumulation. Subsequent proteomic analyses identified Hog1-MAPK as the central signaling hub activated by ROS stress. Upon activation, Hog1 localizes to the nucleus. ROS scavenging (N-acetylcysteine (NAC) treatment) abolished BER's antifungal effects, confirming the ROS-Hog1-cell cycle axis. Crucially, in a murine invasive aspergillosis model, BER reduced the fungal burden in lungs and improved survival rates. Thus, we demonstrate that berberine suppresses A. fumigatus growth by disrupting mitochondrial dynamics, elevating reactive ROS, and activating the Hog1-MAPK signaling cascade, ultimately inducing cell cycle arrest. Our findings unveil a previously unrecognized mechanism linking mitochondrial morphology dysregulation to cell cycle control in fungi and establish BER as a promising therapeutic agent targeting mitochondrial-ROS-Hog1 signaling in A. fumigatus infections.