Role of TGF-bs in normal human endometrium and endometriosis

Endometriosis is characterized by presence of endometrial tissue outside the uterus. Prevalence is estimated at 6-IO% in the general female population and many patients experience pain and/or infertility. Diagnosis is achieved by laparoscopic intervention followed by histological confirmation of viable endometric tissue. Mild cases are managed medically With contraceptive steroids and non-steroidal anti-inflammatory' agents. Surgery provides relief to women in pain but symptoms recur in 75% of cases Within 2 years. Starting with menstruation, we have categorized endometriosis into six stages. namely (I) shedding of cells, (2) cell survival, (3) escape from immune surveillance. (4) adhesion to peritoneum. (5) angiogenesis and (6) bleeding. In most of these biological processes. which resemble metastasis. transforming growth factor. beta (TGf-Bs) and their high-affinity receptors. are Involved directly or Indirectly. TGF-~s are abundantly and differentially expressed 111 the endometrium under hormonal control. Although they are preferentially synthesized in the stroma. glands and rnacrophages also secrete TGF rls Into the uterine fluid. where Interaction With prermplantatton embryos is suspected. Because mRNA and protein expression of all three TGF-~s is increased around menstruauon. we suggest that TGF Bs might be Involved in initiation of menstruation. Furthermore. because of high postrmenstrual TGF -b3 levels, we suppose that it might participate in scarless postmenstrual regeneration of endometrium. Our suggestions pave the- way to novel routes of investigation into the roles or TGF-bs during menstruation and endometriosis.