Lycorine attenuates cardiac fibrosis by regulating PYK2 expression and activity in mouse models

Cardiac fibrosis is a critical pathological process contributing to heart failure, characterized by excessive extracellular matrix deposition and fibroblast activation. Current therapeutic strategies often fall short in effectively reversing established fibrosis. Transforming growth factor-β1 (TGF-β1) is a key pro-fibrotic cytokine, driving fibroblast proliferation and differentiation into myofibroblasts. Identifying novel compounds that target these specific pathways is crucial for developing more effective anti-fibrotic treatments. Lycorine, a natural alkaloid, has shown cardioprotective effects, but its precise role in mitigating cardiac fibrosis and its underlying molecular mechanisms, particularly involving PYK2, remained unclear.

Researchers established in vitro models of pathological fibroblast activation using transforming growth factor-β1 (TGF-β1) to stimulate NIH/3T3 cells and primary rat cardiac fibroblasts. For in vivo studies, a mouse model of cardiac fibrosis was induced via intraperitoneal injection of doxorubicin (DOX). The effects of Lycorine (LYC) on TGF-β1-induced fibroblast activation, proliferation, and migration were assessed using Western blotting, quantitative PCR, scratch assays, and EdU staining. Cardiac damage and fibrosis in mice were evaluated by echocardiography, ELISA, and Masson's trichrome staining. Transcriptomic sequencing and bioinformatic analyses identified proline-rich tyrosine kinase 2 (PYK2) as a potential target, which was validated using siPYK2 and the PYK2 inhibitor PF4618433 in TGF-β1-induced NIH/3T3 cells.

Lycorine effectively suppressed TGF-β1-induced fibroblast activation, proliferation, and migration in vitro. In the doxorubicin-induced mouse model, Lycorine significantly ameliorated cardiac dysfunction and reduced collagen deposition in myocardial tissues, thereby attenuating the progression of cardiac fibrosis. These beneficial effects were mechanistically attributed to Lycorine's regulation of PYK2 expression and activity. Transcriptomic sequencing initially identified PYK2 as a potential target. This finding was further validated in vitro using siPYK2 to knockdown PYK2 and by applying the specific PYK2 inhibitor PF4618433 in TGF-β1-stimulated NIH/3T3 cells, confirming PYK2's critical role in mediating Lycorine's anti-fibrotic actions. The study provides a scientific basis for understanding Lycorine's mechanism in improving cardiac fibrosis.

Lycorine significantly ameliorated cardiac dysfunction and reduced collagen deposition in myocardial tissues, attenuating cardiac fibrosis progression by regulating PYK2 expression and activity.