Testosterone regulates myosin II isoforms expression and functional activity in the rat prostate

Area of Science:

• Urology
• Molecular Biology
• Cell Biology

Background:

• Benign prostatic hyperplasia (BPH) involves increased prostatic smooth muscle (SM) tone and volume.
• SM myosin II (SMM II) and non-muscle myosin II (NMM II) are key regulators of SM tone and cell proliferation.
• Testosterone (T) plays a critical role in BPH development.

Purpose of the Study:

• To investigate the effects of T on rat prostatic cell proliferation, apoptosis, and SM contractility.
• To elucidate the regulatory signaling pathways involved in T's effects on the prostate.

Main Methods:

• 36 male rats were divided into sham-operated, castrated, and T-supplemented castrated groups.
• In vitro organ bath studies, RT-PCR, Western-blotting, and Masson's trichrome staining were employed.
• Immunofluorescence staining assessed SM cell numbers and myosin expression.

Main Results:

• Castration increased prostatic SM contractility and SM cell numbers.
• T deprivation altered SMM II isoform composition, favoring faster contractions.
• Castration affected NMM II heavy chain isoforms, potentially impacting cell proliferation and apoptosis.

Conclusions:

• Testosterone regulates SMM II and NMM II functional activities in the rat prostate.
• T ablation impacts both the static (size) and dynamic (tone) components of the prostate.