Translocator protein expression and localization in human endometrium and endometriosis: A potential target for a noninvasive diagnosis?

The limitations of current imaging methods to detect small or superficial endometriotic lesions prompt the search for new molecular targets. TSPO is an 18 KDa protein located in the outer mitochondrial membrane, which can be traced by positron emission tomography (PET) using specific ligands. TSPO is located mostly in neurons and inflammatory sites outside the brain. We hypothesized that it might also be expressed in the human endometrium and endometrial-like tissue, being a target for molecular imaging of endometriosis. This prospective cross-sectional study included 28 women with endometriosis and 11 endometriosis-free controls. Endometriotic lesions (n = 49) and normal peritoneum (n = 13) from endometriosis patients were obtained during laparoscopy, while samples of eutopic endometrium from patients with endometriosis (n = 28) and from control women (n = 11) were collected in the operating room using a flexible device. TSPO mRNA expression was evaluated by quantitative reverse-transcription real-time PCR while protein expression was evaluated by immunohistochemistry with a monoclonal antibody antihuman TSPO. TSPO mRNA expression was detected in an invariable fashion in all tissue types evaluated; however, TSPO protein was found to be more abundant in the glandular epithelium than in the stroma, both in the endometrium and in the endometriotic lesions. Interestingly, hormone therapies did not alter the expression of TSPO, and its presence was mostly negative in tissues adjacent to endometriotic implants. As a proof of concept, the protein expression pattern of TSPO in endometriotic tissue and along the adjacent areas suggests that TSPO-based molecular imaging might be used for noninvasive endometriosis detection.

Endometriosis and related pelvic pain: association with stress, anxiety and depressive symptoms.

Endometriosis is a chronic inflammatory disease affecting 10% of women in reproductive age and manifested as infertility and pelvic pain, which may be severe and incapacitating. This review aims to address the latest evidence on the association of endometriosis with chronic stress, anxiety and depression, and to find out whether the effective treatment of endometriosis has the additional benefit of attenuating these psychological comorbidities. Studies have found that women with endometriosis, especially those with painful symptoms, have higher levels of stress and a decreased quality of life compared to healthy women. Importantly, depression and anxiety are more prevalent in women with endometriosis, and the presence of psychiatric disorders correlates more to the severity of the endometriosis-related pain than to other disease characteristics. Considering therapeutic implications, controlled clinical trials found that medical and surgical treatments of endometriosis also ameliorated perceived stress, anxiety and depressive symptoms. In conclusion, current evidence indicates that women with endometriosis have an increased prevalence of psychological disorders which correlate more with pain itself than with endometriosis per se. In addition, the effective treatment of endometriosis may reduce the psychological burden of the disease.