Targeting ROCK1/YAP1 Axis Ameliorates Inflammation‐Induced Prostatic Hyperplasia via Stabilising SIRT1‐Dependent Mitochondrial Dynamics

ABSTRACT Benign prostatic hyperplasia (BPH) is a common condition in older men, with its prevalence increasing as age advances. Chronic inflammation orchestrates oxidative stress to exacerbate BPH. YAP1, which regulates organ size, cellular homeostasis, and tissue fibrosis, can be activated by ROCK1. Given the urgent clinical need for more effective therapies, this study explored whether targeting the ROCK1/YAP1 axis could mitigate BPH progression. Here, rats received in situ adeno‐associated virus (AAV) injection to induce prostate‐specific YAP1 overexpression. An inflammation‐associated experimental autoimmune prostatitis (EAP) model was established by prostate antigen immunisation, followed by treatment with ROCK1 inhibitor fasudil and YAP1 inhibitor verteporfin. Cell models were treated with specific inhibitors to confirm the critical role of YAP1 in modulating mitochondrial function. As a result, YAP1 overexpression was sufficient to induce a pathological BPH phenotype. Specifically, YAP1 activated the inflammatory cascade to provoke an immune response, disrupted proliferation/apoptosis balance to induce tissue hyperplasia, triggered epithelial‐mesenchymal transition (EMT) and reactive stroma to drive fibrosis, and promoted NOX4/ROS generation and antioxidant depletion to cause oxidative stress. The inflammation‐induced experimental autoimmune prostatitis (EAP) model also presented analogous BPH lesions, which were significantly alleviated when treated with ROCK1 inhibitor fasudil and YAP1 inhibitor verteporfin. Mechanistically, YAP1 activation under inflammatory conditions suppressed SIRT1 expression, thereby exacerbating oxidative stress through the disruption of DRP1/MFN2‐mediated mitochondrial dynamics. Overall, inflammation‐driven activation of the ROCK1/YAP1 axis aggravates oxidative stress, promoting BPH hyperplasia and fibrosis by impairing SIRT1‐regulated mitochondrial dynamics. These findings provide a preclinical rationale for developing ROCK1 or YAP1 inhibitors as targeted therapies for BPH patients with chronic inflammation.