Expression and functional activity of myosin II in hyperplastic prostates of varying volumes

Prostate volume (PV) differs dramatically among benign prostatic hyperplasia (BPH) patients. Estimation of PV is important to guide the most appropriate pharmacologic or interventional treatment approach. However, the underlying pathophysiological mechanisms for the differences in PV remain unknown. We recently found that the myosin II system might participate in the etiology and development of BPH via static and dynamic factors. Our present study aims to explore the expression and functional activities of myosin II isoforms including smooth muscle (SM) myosin II (SMM II) and non-muscle myosin II (NMM II) in hyperplastic prostates with varied PV. Human hyperplastic prostates and the testosterone-induced rat BPH model were employed for this study. He-matoxylin and Eosin (H & E), Masson's trichrome, immunohistochemical staining, in vitro organ bath, RT-polymerase chain reaction (PCR) and Western-blotting were performed. Also, a BPH tissue microarray (TMA) was constructed to determine the correlations between myosin II isoforms with clinical parameters of BPH pa-tients. With the increase of PV, the expression of NMMHC-A, NMMHC-C, SM-A and LC17b isoforms were increased, and the contractility of prostate smooth muscle was enhanced but force developed more slowly. Consistently, NMMHC-A, NMMHC-C, SM-A and LC17b were correlated positively with PV. Similar outcomes were also observed in the BPH rat model with different PVs. Alterations in the expression and function of myosin the II system may be involved in the pathophysiological mechanism of PV differences between BPH patients.

Automated summary

Prostate volume (PV) varies greatly among benign prostatic hyperplasia (BPH) patients, and estimating PV is crucial for determining the most suitable treatment approach. However, the mechanisms underlying these PV differences are still unknown. Our study examined the expression and functional activities of myosin II isoforms in hyperplastic prostates of varying volumes. The findings suggest that alterations in the myosin II system may play a role in the pathophysiological mechanisms responsible for PV differences in BPH patients.