Hormone receptor expression in human fascial tissue

Area of Science:

• Connective tissue research
• Endocrinology
• Pain research

Background:

• Epidemiological and clinical data suggest sex differences in myofascial pain prevalence, with women affected more frequently than men.
• Hormonal factors, specifically estrogen and relaxin, are implicated in extracellular matrix remodeling and may influence fascial nociceptor sensitization.

Purpose of the Study:

• To investigate the expression and localization of estrogen receptor-alpha (ERα) and relaxin receptor 1 (RXFP1) in human fascia.
• To explore the potential link between sex hormone receptors in fascia and the higher incidence of myofascial pain in women.

Main Methods:

• Immunohistochemistry and real-time PCR analysis were used to examine ERα and RXFP1 expression in human fascia samples from 8 female volunteers (pre- and post-menopausal).
• Fibroblasts isolated from deep fascia were analyzed for protein and RNA expression levels of these receptors.

Main Results:

• Both ERα and RXFP1 were expressed in human fascial tissues and cultured fascial fibroblasts.
• Receptor expression was generally lower in post-menopausal women compared to pre-menopausal women.
• RXFP1 expression was observed in fibroblasts, blood vessels, and nerves, while ERα was concentrated in fibroblasts.

Conclusions:

• This study provides the first evidence that fibroblasts in various human fascial districts express sex hormone receptors.
• These findings support the hypothesis that hormonal factors, through their action on fascial fibroblasts, contribute to myofascial pain, particularly in women.
• Understanding the role of estrogen and relaxin in extracellular matrix remodeling may offer new insights into managing fascial stiffness and pain sensitization.