Bisphenol A disruption promotes mammary tumor microenvironment via phenotypic cell polarization and inflammatory response.

Inflammation in the established tumor microenvironment (TME) is often associated with a poor prognosis of breast cancer. Bisphenol A (BPA) is an endocrine-disrupting chemical that acts as inflammatory promoter and tumoral facilitator in mammary tissue. Previous studies demonstrated the onset of mammary carcinogenesis at aging when BPA exposure occurred in windows of development/susceptibility. We aim to investigate the inflammatory repercussions of BPA in TME in mammary gland (MG) during neoplastic development in aging. Female Mongolian gerbils were exposed to low (50 µg/kg) or high BPA (5000 µg/kg) doses during pregnancy and lactation. They were euthanized at 18 months of age (aging) and the MG were collected for inflammatory markers and histopathological analysis. Contrarily to control MG, BPA induced carcinogenic development mediated by COX-2 and p-STAT3 expression. BPA was also able to promote macrophage and mast cell (MC) polarization in tumoral phenotype, evidenced by pathways for recruitment and activation of these inflammatory cells and tissue invasiveness triggered by tumor necrosis factor-alpha and transforming growth factor-beta 1 (TGF-ß1). Increase of tumor-associated macrophages, M1 (CD68 + iNOS+) and M2 (CD163+) expressing pro-tumoral mediators and metalloproteases was observed; this aspect greatly contributed to stromal remodeling and invasion of neoplastic cells. In addition, the MC population drastically increased in BPA-exposed MG. Tryptase-positive MCs increased in disrupted MG and expressed TGF-ß1, contributing to EMT process during carcinogenesis mediated by BPA. BPA exposure interfered in inflammatory response by releasing and enhancing the expression of mediators that contribute to tumor growth and recruitment of inflammatory cells that promote a malignant profile.

Telocytes are associated with tissue remodeling and angiogenesis during the postlactational involution of the mammary gland in gerbils.

The postlactational involution of the mammary gland is a complex process. It involves the collapse of the alveoli and the remodeling of the extracellular matrix, which in turn implies a complex set of interrelations between the epithelial, stromal, and extracellular matrix elements. The telocytes, a new type of CD34-positive stromal cell that differs from fibroblasts in morphological terms and gene expression, were detected in the stroma of several tissues, including the mammary gland; however, their function remains elusive. The present study employed three-dimensional reconstructions and immunohistochemical, ultrastructural, and immunofluorescence techniques in histological sections of the mammary gland of the Mongolian gerbil during lactation and postlactational involution to evaluate the presence of telocytes and to investigate a possible function for these cells. By means of immunofluorescence assays for CD34 and c-kit, major markers of telocytes, and also through morphological and ultrastructural evidences, telocytes were observed to surround the mammary ducts and collapsing alveoli. It was also found that these cells are associated with matrix metalloproteinase 9, which indicates that telocytes can play a role in extracellular matrix digestion, as well as vascular endothelial growth factor, a factor that promotes angiogenesis. Together, these data indicate that telocytes are a distinct cell type in the mammary gland and, for the first time, show that these cells possibly play a role in tissue remodeling and angiogenesis during the postlactional involution of the mammary gland.

The characterization and therapeutic applications of ovarian theca cells: An update.

Theca cells perform a range of roles during folliculogenesis. So far, little is known about their recruitment process and function since early research has mainly focused on the interactions between granulosa cells and the oocyte, leaving theca cells unfairly forgotten in the understanding of ovarian physiology and pathogenesis. Given that research on theca cells has greatly emerged in recent years, this review of literature aims to discuss the established theoretical concepts with the most recent findings about theca cells' characterization and origins, in vitro culture applications as models for fertility preservation and pharmacological/toxicological studies, its importance in unraveling pathogenic pathways, and stem-cell-based bioengineering for hormonal replacement therapies. Isolation and in vitro culture techniques for theca cells have led to essential advancements in their characterization as a specific cell population. Unraveling the origins of theca cells during the in vivo differentiation process in the adult ovary will assist the development of hormonal replacement therapies, reestablishment of fertility, and treatments for diseases such as premature ovarian insufficiency and polycystic ovarian syndrome, which seem to be directly influenced by theca cells.

New Solutions for Old Problems: How Reproductive Tissue Engineering Has Been Revolutionizing Reproductive Medicine.

Acquired disorders and congenital defects of the male and female reproductive systems can have profound impacts on patients, causing sexual and endocrine dysfunction and infertility, as well as psychosocial consequences that affect their self-esteem, identity, sexuality, and relationships. Reproductive tissue engineering (REPROTEN) is a promising approach to restore fertility and improve the quality of life of patients with reproductive disorders by developing, replacing, or regenerating cells, tissues, and organs from the reproductive and urinary systems. In this review, we explore the latest advancements in REPROTEN techniques and their applications for addressing degenerative conditions in male and female reproductive organs. We discuss current research and clinical outcomes and highlight the potential of 3D constructs utilizing biomaterials such as scaffolds, cells, and biologically active molecules. Our review offers a comprehensive guide for researchers and clinicians, providing insights into how to reestablish reproductive tissue structure and function using innovative surgical approaches and biomaterials. We highlight the benefits of REPROTEN for patients, including preservation of fertility and hormonal production, reconstruction of uterine and cervical structures, and restoration of sexual and urinary functions. Despite significant progress, REPROTEN still faces ethical and technical challenges that need to be addressed. Our review underscores the importance of continued research in this field to advance the development of effective and safe REPROTEN approaches for patients with reproductive disorders.

Impairment of steroidogenesis and follicle development after bisphenol A exposure during pregnancy and lactation in the ovaries of Mongolian gerbils aged females.

The ovaries regulate fertility and hormonal control in females, and aging is a crucial factor in this process, when ovarian function is drastically impacted. Exogenous endocrine disruptors may accelerate this process, acting as the main agents in decreased female fertility and hormonal imbalance, since they impact different features related to reproduction. In the present study, we demonstrate the implications of exposure of adult mothers to the endocrine disruptor bisphenol A (BPA) during pregnancy and lactation on their ovarian function during the transition to later in life (aging). The follicle population of BPA exposed ovaries showed impairment in the development of follicles to the mature stages, with growing follicles being halted in the early stages. Atretic and early-atretic follicles were also enhanced. Expression of estrogen and androgen receptors in the follicle population demonstrated impairment in signaling function: ERß was highly expressed in follicles from BPA exposed females, which also showed a higher incidence of early atresia of developed follicles. ERß1 wild-type isoform was also enhanced in BPA-exposed ovaries, compared to its variant isoforms. In addition, steroidogenesis was targeted by BPA exposure: aromatase and 17-ß-HSD were reduced, whereas 5-α reductase was enhanced. This modulation was reflected in serum levels of estradiol and testosterone, which decreased in BPA-exposed females. Imbalances in steroidogenesis impair the development of follicles and play an important role in follicular atresia. Our study demonstrated that BPA exposure in two windows of susceptibility - gestation and lactation - had implications during aging, enhancing perimenopausal and infertile features.

Mammary carcinoma in aged gerbil mothers after endocrine disruption in pregnancy and lactation.

Compounds that trigger breast cancer onset and establishment are of great interest in biological research. Endocrine disruptors are relevant because they initiate carcinogenesis by changing endocrine pathways. Bisphenol A (BPA), as a ubiquitous xenoestrogen, is largely associated with dysfunctions in the female reproductive system and associated organs. This study proposes an investigation of the mammary gland (MG) in aged Mongolian gerbil (Meriones unguiculatus) mothers after their exposure to BPA in two windows of morphophysiological plasticity: pregnancy and lactation. A low dose (50 µg/kg) and a high dose (5000 µg/kg) of BPA were considered, and results showed few differences between them. As expected, we observed contrasts among control and BPA-exposed MG. The control groups presented a regressive phase with high apoptotic activity and elastic stroma. However, BPA damaged mammary tissue and provoked multifocal carcinoma development supported by an apparent epithelial-mesenchymal transition (EMT) and reactive stroma establishment. BPA remodeled stromal fibers deposition and enhanced the recruitment of tumor-associated cells, contributing to a tumoral microenvironment. Overexpression of TGF-ß1 was induced by BPA in the epithelial compartment of exposed MG, and increased expression of metalloproteinases (MMP-2, MMP-3, MMP-9) was present in carcinoma cells. In conclusion, exposure of mothers to BPA during the gestational/lactational window of susceptibility leads to carcinogenic impacts with aging.

Function of Cryopreserved Cat Ovarian Tissue after Autotransplantation.

The aim of this study was to assess a slow-freezing protocol of cat ovarian tissue cryopreservation using autotransplantation. Four adult queens were ovariohysterectomized and the ovaries were fragmented and cryopreserved. After one week, the grafts were thawed and autografted to the subcutaneous tissue of the dorsal neck of each queen, then randomly removed after 7, 14, 28, 49, and 63 days after transplantation. Percentages of morphologically normal primordial and growing follicles (MNFs) were 88% and 97%, respectively, in fresh tissue samples (fresh controls), and 74% and 100%, respectively, immediately after thawing (cryo D0). No MNFs were found after 49 days of transplantation. In both fresh control and cryo D0 fragments, granulosa cells were frequently in proliferation. Two morphologically normal antral follicles were detected in one queen on Day 28 post-transplantation. Connective tissue fibers increased, suggesting replacement of active ovarian cortex by fibrous tissue. Tissue vascularization was observed at 7 days after grafting, and wide blood vessels were clearly visible on Days 49 and 63. In conclusion, although follicular survival was low after cryopreservation and grafting of cat ovarian tissue, follicles were able to develop up to the antral stage, which is an encouraging outcome.

Restoration of fresh cat ovarian tissue function by autografting to subcutaneous tissue: A pilot study.

Ovarian tissue transplantation could be a valuable technique for the preservation of endangered animals. The domestic cat affords an adequate experimental model for studies aimed at wild felids due to its phylogenetic similarity. Thus, this pilot study evaluated the efficacy of cat ovarian tissue autotransplantation to a peripheral site. Three adult queens were submitted to ovariohysterectomy. The ovaries were fragmented into eight pieces; two were fixed as a control and six were transplanted to subcutaneous tissue of the dorsal neck. Grafts were monitored weekly by ultrasound and fecal samples collected daily in order to monitor estradiol levels. Grafts were recovered on Days: 7, 14, 28, 49 and 63 post-transplantation for histological analyses. One graft was maintained in one animal for 8 months. A total of 2466 ovarian follicles were analyzed: 1406 primordial and 1060 growing follicles. All animals presented antral follicles in one or more of the grafts. The percentage of morphologically normal primordial follicles was always higher than 80%, except for Day 7 transplants. Although the proportion of growing follicles increased after transplantation, there was a general decrease in the percentage of morphologically normal growing follicles from Day 7 onwards. All animals demonstrated at least three estradiol peaks during the 63-day period, and one animal exhibited estrous behaviour on three occasions. Hormonal peaks directly correlated with the visualization of antral follicles (by ultrasound and/or histology) and the observation of estrous behaviour. Long-term results on one female showed the concentration of 37.8 pg/mL of serum estradiol on Day 233 post-grafting and the female exhibited estrous behaviour on several occasions. This graft showed one antral follicle, one luteinized follicle and two preantral follicles. In conclusion, cat ovary autotransplantation to the subcutaneous tissue restored ovarian function, with hormone production and antral follicle development, over both short and long term periods. This could be a valuable technique in the evaluation of ovarian cryopreservation methods in felids. Once the technique is shown successful, it may be applied in allografts or xenografts between different feline species.

Histological and immunohistochemical characterization of the Mongolian gerbil's mammary gland during gestation, lactation and involution.

The morphological description of normal tissues is fundamental for making comparisons and in order to identify injuries and lesions. The aim of this work was to describe the morphological characteristics of the female Mongolian gerbil's (Meriones unguiculatus) normal mammary gland, the average expression of hormone receptors, and the average proliferation rates in the epithelial cells during the periods of lactation, pregnancy and involution. Dams were euthanized on the 14th and 21st gestational days, 7 and 14days after parturition, and 3 and 5days after weaning. The dams' mammary tissues were processed and were submitted to haematoxylin and eosin staining, Periodic Acid Schiff (PAS) staining, and Gomori's Reticulin staining. Additionally, immunohistochemistry was performed for the characterization of myoepithelial cells with α-actin, the proliferation rates with proliferating cell nuclear antigen (PCNA), the estrogen hormonal receptors (ESR1 and ESR2), and progesterone receptor (PR) quantifications. It was observed that the abundant adipose tissues were replaced by glandular epithelia and there was an increase in the epithelial cell's height (from 5.97 to 32.4µm in 14th and 21st gestational days and from 20.64 to 25.4µm in 7th and 14th lactational days, respectively) and the acini diameters (from 24.88 to 69.92µm in 14th and 21st gestational days and from 139.69 to 118.59µm in 7th and 14th lactational days, respectively) with the progression of gestation and lactation. The PAS staining intensity varied throughout the glands and between the stages that were evaluated. The extracellular matrix showed different phenotypes too, with more of a presence of the Type I collagen during the early gestation and involution and with more reticular fibers (Type III collagen) during the late gestation period and lactation. The myoepithelial layers showed alterations in their distribution with thick patterns as verified by the α-actin labeling. The PCNA showed higher rates of the marked cells in 14th and 21st gestational days (40.25 and 60.28%) and in 7th and 14th lactational days (64.08 and 65.08%). The hormone receptor quantifications showed a high variation in the rates: the average PR staining decreased from 14th to 21st gestational days (from 42.3 to 8.54%), from 7th to 14th lactational days (from 59.83 to 23.18%) and from 3rd to 5th days after weaning (from 39.98 to 12.72). There were higher averages of ESR1 staining in gestational days 14 and 21(from 58.06 to 30.02%). ESR2 staining decreased during gestation (25.7 and 12.94% in 14th and 21st gestational days)and involution (from 50.97 to 30.18% in 3rd and 5th days after weaning). The Mongolian gerbils showed similar morphological characteristics when they were compared to mice and rats. However, the higher proliferation rates with a smaller involution period compared to other murine characterized this species as being adequate for mammary pathologies studies.