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.

Altered Endometrial Expression of α-Inhibin Subunit and Its Co-Receptor Betaglycan in Infertile Women with Endometriosis.

BACKGROUND: Inhibins and their co-receptor betaglycan are members of the transforming growth factor ß superfamily, a group of signaling molecules that control the differentiation of human endometrium in the secretory phase of the menstrual cycle. OBJECTIVE: Since endometriosis is associated with endometrial dysfunction and infertility, this study aimed at evaluating the expression of α-inhibin and betaglycan mRNA and proteins in endometrial samples of infertile women with and without endometriosis. DESIGN: This was a cross-sectional study. Participants/Materials: Endometrial samples of women with (n = 17) and without (n = 22) endometriosis were subdivided according to the menstrual cycle phase into proliferative and secretory. SETTING: University hospital. METHODS: We used real-time RT-PCR to quantify mRNA levels and immunohistochemistry to localize the proteins. RESULTS: α-inhibin mRNA levels were significantly increased in the secretory phase (p < 0.01 vs. proliferative phase) only among women with endometriosis. Conversely, betaglycan mRNA levels were downregulated in the secretory endometrium of controls (p < 0.01 vs. proliferative) but failed to change between cycle phases of patients with endometriosis. Both proteins were present in the glandular epithelium and stroma in the endometrium of women with and without endometriosis. Immunostaining analysis showed that while α-inhibin protein expression did not vary significantly, the intensity of betaglycan immunostaining decreased in the secretory phase in the control group (p = 0.038 vs. proliferative phase) but not in the endometriosis group. LIMITATIONS: We cannot determine whether endometriosis causes the abnormal expression of α-inhibin and betaglycan in the eutopic endometrium or if this alteration already existed before the establishment of endometriotic lesions. CONCLUSION: Our findings suggest an abnormally increased expression of α-inhibin mRNA (not protein) and betaglycan (mRNA and protein) in the secretory-phase endometrium of women with endometriosis.

Uterine Fibroids and Pregnancy: How Do They Affect Each Other?

The present narrative review is aimed to rekindle discussion regarding whether and how uterine leiomyoma and pregnancy may impact each other. Although fibroids are hormone-dependent lesions, their growth during pregnancy seems to have a nonlinear trend. Besides placental estrogens and progesterone, an array of endocrine and paracrine factors affect fibroid blood supply, growth rate, and risk of degeneration along the gestational and puerperal periods. According to current evidence, the presence of leiomyomas might increase the risk of some adverse pregnancy outcomes. Although a causative relation between fibroids and spontaneous abortion is questionable, the presence of multiple submucosal lesions in certain populations, such as infertile women, may increase the risk of pregnancy loss. Slightly increased risks of placenta previa, placental abruption and fetal malpresentation may occur, mainly due to the mechanical influence of multiple and large fibroids. Cesarean section and preterm birth rates are also probably increased in the presence of fibroids. The risk associations are based on meta-analyses of cohort studies (level of evidence 2a), retrospective cohort studies (2b), case-control (3a), and cross-sectional studies (3b), but with a predominantly low risk of bias. For evaluating the growth pattern of leiomyomas and their real influence on obstetric outcomes, future studies should enroll women with fibroids diagnosed prior to pregnancy and follow them prospectively throughout the gestation and puerperium.

Serum and urine levels of activin A in primigravidae and multigravidae: a prospective cross-sectional study.

The aim of the present study was to investigate serum and urine levels of activin A in different moments of gestation, in primigravidae and in multigravidae, to understand whether these variables (biological sample and first gestation) affect activin A as a biomarker in pregnancy. We prospectively included 43 pairs of serum and urine samples from 25 women examined at different gestational ages (range 45 to 268 days). In the group of primigravidae (n = 16 samples from 9 participants), there was no significant change in serum activin A levels across gestation. Conversely, the group of multigravidae (n = 27 samples from 16 women) had higher serum activin A levels in the third trimester (2676 ± 840 pg/ml) compared to the first (583 ± 408 pg/ml) and second (1040 ± 384) trimesters (p = .025). Urine activin A concentrations did not differ between the two groups and did not change according to the gestation phase. There was no correlation between serum and urinary levels of activin A (r = 0.149, p = .359). These data suggest that activin A secretion may vary less during the first pregnancy, while urine activin A is unlikely to be a surrogate for the systemic levels of this hormone in pregnant women.

Angiotensin-converting enzyme 2, the SARS-CoV-2 cellular receptor, is widely expressed in human myometrium and uterine leiomyoma.

OBJECTIVE: Angiotensin-converting-enzyme 2 (ACE2), the cell surface receptor for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is found in a variety of reproductive tissues. The present study evaluated whether uterine fibroids and normal myometrium express ACE2 and, if so, at which tissue compartments. METHODS: We included 13 premenopausal women (age range 33-50 years, median 40 years) with uterine fibroids undergoing elective hysterectomy or myomectomy. Samples of leiomyoma (n = 12) and normal myometrial tissue (n = 8) were analyzed by immunohistochemistry for protein localization or by real time PCR for mRNA detection. RESULTS: In normal myometrium, ACE2 immunoreactivity was localized in smooth muscle fibers, arteriolar walls, and endothelial cells. In uterine leiomyoma, ACE2 staining was more intense in smooth muscle cells than in the extracellular matrix, and was also present in vascular endothelium. ACE2 mRNA was detected in myometrium as well as in fibroid samples. CONCLUSION: Human myometrium and uterine leiomyoma express ACE2 mRNA and have abundant distribution of ACE2 protein in their smooth muscle cells and microvasculature.

A fertility-oriented method for histological processing of testicular biopsies in men with azoospermia.

The present study was designed to evaluate whether tissue preparation by glutaraldehyde and glycol methacrylate (G/GMA) improves the diagnostic assessment of testicular biopsies from azoospermic men when compared to the standard tissue preparation using Bouin's solution and paraffin. We prospectively included a total of 21 testicular biopsies of sexually mature men aged 29-50 years with infertility and azoospermia. One testicular biopsy fragment from each patient was processed by the G/GMA method, whereas another tissue fragment was contemporarily processed by the conventional Bouin/paraffin (B/P) method. The G/GMA method provided better resolution of cytological details of the seminiferous epithelium, changing the final diagnosis in four cases. The medians of Bergmann's spermatogenesis scores were 0.25 (interquartile range 0.04-0.88) for B/P preparations and 0.79 (interquartile range 0.17-0.96) for G/GMA preparations. Both techniques allowed accurate prediction of sperm recovery from the biopsies (B/P, area under the receiver operating characteristics [ROC] curve 0.88, 95% confidence interval [CI] 0.75-1.00; G/GMA, area under the ROC curve 0.94, 95% CI 0.86-1.00). We conclude that human testicular biopsy preparation with G/GMA improved image resolution under light microscopy and produced more reliable results for the evaluation of spermatogenesis in comparison with B/P, allowing a more precise fertility-oriented diagnosis in azoospermic men.Abbreviations: B/P: Bouin/paraffin; GMA: glycol methacrylate; G/GMA: glutaraldehyde and glycol methacrylate; ICSI: intracytoplasmic sperm injection; OA: obstructive azoospermia; NOA: nonobstructive azoospermia; TESE: testicular sperm extraction.

A rare case of endometrioma in a bitch.

BACKGROUND: Endometriosis is ectopic development of endometrial glands and stroma in extra-uterine sites and if the lesions occur as a well-defined mass is referred to as endometrioma. In the literature, endometrioma has been reported in only women and there are no reports of endometrioma in animals, including non-human primates. CASE PRESENTATION: A rare case of endometrioma is reported in an 11-year-old female German Shepherd with clinical signs of dehydration, anemia and prostration. Necropsy revealed ascites, generalized pallor, and a well-demarcated reddish mass adjacent to the left ovary and uterus and adherent to the retroperitoneum. The mass measured 25.0 × 20.0 cm with intermingled soft and firm areas. Upon incision, the mass was found to be solid with variable sized cystic cavities filled with coagulated blood. Microscopically, the mass was composed of cuboidal or prismatic epithelial cells arranged in tubules or acini. The epithelium of the mass had similar characteristics to the normal endometrium with PAS-positive secretions. The stroma was prominent and formed by loose connective tissue and smooth muscle fibers as confirmed by Masson trichrome. Extensive multifocal areas of hemorrhage were also observed in the stroma of the mass and in the interior of some epithelium-lined, cystic structures. Most of the epithelial cells had strong and diffuse cytokeratin expression, and some had vimentin expression. Epithelial and stromal cells also showed ERß, AR, VEGF and COX2 expression. The stroma showed areas with strong and diffuse vimentin expression. Factor VIII expression was observed only in the endothelium of blood vessels in the stroma. CONCLUSIONS: The macroscopic, microscopic and immunohistochemical findings are consistent with an endometrioma.