New Insights into Male Hormone Mechanism Could Pave Way for Safer Muscle-Enhancing Treatments

Researchers have identified a novel mechanism by which the male sex hormone, crucial for muscle and bone health, operates. This groundbreaking discovery has potential implications for the development of muscle-strengthening drugs that offer fewer side effects, particularly beneficial for patients with limited mobility. The findings were published in the prestigious journal Cell.

Androgens, a class of hormones that influence the development of male physical characteristics, include 5?-dihydrotestosterone (5?-DHT), the most potent androgen. 5?-DHT plays a vital role in bone density and muscle growth, contributing significantly to muscle strength and the development of secondary male traits during puberty.

In this international collaborative study, scientists demonstrated that GPR133, a type of adhesion G protein-coupled receptor, is activated by the androgenic steroid hormone 5?-DHT. This activation has the potential to enhance the contractile force of skeletal muscles, as explained by researchers involved in the study.

Crucially, the activation of GPR133 using a newly developed agonist, AP503, has been shown to boost muscle strength without triggering the adverse effects commonly associated with androgen use. Traditional androgen treatments, such as testosterone, have been linked to undesirable side effects, including an increased risk of prostate cancer, even after brief exposure.

The current study employed structural biology techniques to unravel the molecular interactions between the steroid hormone, the substance AP503, and GPR133. This understanding will enable the optimization of the activator for further development as a therapeutic agent, potentially leading to innovative muscle-strengthening medications with a reduced side effect profile.

This research stems from a successful long-term partnership between the Rudolf Schönheimer Institute of Biochemistry and a research team led by Professor Jin-Peng Sun at Shandong University in China. Ongoing investigations are examining the therapeutic applications of AP503 in various disease contexts and exploring the broader role of GPR133 within biological systems. Initial data were collected through animal model studies, and further research will be necessary to assess the applicability of these findings in human subjects.