Expansion of specialized epidermis induced by hormonal state and mechanical strain

In mammals, some sites of specialized skin such as the palms, soles, and lips grow proportionally with the animal. However, other types of specialized skin such as the nipple and anal/genital region are dramatically altered with changes of reproductive status. The specific cell types that mediate the growth of these sites have not been identified. In the mouse, we observed a dramatic expansion of the specialized epidermis of the nipple, coupled to changes in connective tissue and hair shaft density, which we designate as areola formation. During this process thymidine analog uptake was elevated in the epidermis and hair follicles. Although there were no changes in connective tissue cell proliferation, we did observe an altered expression of extracellular matrix genes. In addition, the fibroblasts of the virgin nipple areola and region showed increased transcript and protein levels for estrogen, progesterone, relaxin, and oxytocin relative to those of ventral skin. To determine the role of pregnancy, lactation hormonal milieu, and localized mechanical strain on areola formation, we created models that separated these stimuli and evaluated changes in gross structure, proliferation and protein expression. While modest increases of epidermal proliferation and remodeling of connective tissue occurred as a result of individual stimuli, areola formation required exposure to pregnancy hormones, as well as mechanical strain

The Anti-Metastatic nm23-1 Gene Is Needed for the Final Step of Mammary Duct Maturation of the Mouse Nipple

Nm23/NDP kinases are multifunctional enzymes involved in the general homeostasis of triphosphate nucleosides. Numerous studies have shown that NDPKs also serve as regulatory factors of various cell activities, not always connected to nucleotide phosphorylation. In particular, the nme-1 gene, encoding the NM23-1/NDPKA protein, has been reported as a metastasis suppressor gene. This activity was validated in hepatocellular tumors induced in nm23-1 deficient mice. Yet, data describing the primary physiological functions of nm23-1/NDPKA is still scarce. We have characterized in depth the phenotype of nm23-1 deletion in the mammary gland in mice carrying whole body nm23-M1 invalidation. We also asked why the nm23-M1−/− mutant females displayed severe nursing disability. We found that the growth retardation of mutant virgin glands was due to reduced proliferation and apoptosis of the epithelial cells within the terminal end buds. The balance of pro/anti-apoptotic factors was impaired in comparison with wild type glands. In the lactating glands, the reduced proliferation rate persisted, but the apoptotic factors were unchanged. However, those defects did not seem to affect the gland maturation since the glands lacking nm23-1/NDPKA appeared morphologically normal. Thorough examination of all the functional aspects of the mammary glands revealed that lack of nm23-1/NDPKA does not impact the production or the ejection of milk in the lumen of lobuloalveolae. Interestingly, an epithelial plug was found to obstruct the extremity of the unique lactiferous duct delivering the milk out of the nipple. These cells, normally disappearing after lactation takes place, persisted in the mutant nipples. This work provides a rare instance of nm23-1/NDPKA physiological functions in the mammary glands and reveals its implication as a modulator factor of proliferation and apoptosis in this tissue

The Effects of Estradiol, Androgens and the Selective Estrogen Modulators: Ospemifene, Raloxifene and Tamoxifen on Explant Cultures of Human Breast Tissue

The impact of menopausal hormone therapy (MHT) on increasing the risk for breast cancer (BC) remains controversial. To understand MHT-elicited cellular breast effects and the potential risks, included with using this therapy, a further investigation into this controversy is the subject of this thesis. In this thesis, to study the effects of estrogen, progestin, androgens and selective estrogen receptor modulators (SERMs), a modified tissue explant culture system was used. The different types of human breast tissues (HBTs) used in this study were normal HBTs, obtained from reduction mammoplasties of premenopausal women (prem-HBTs) or postmenopausal (postm-HBTs) women and peritumoral HBTs (peritum-HBTs) which were obtained from surgeries on postmenopausal BC patients. The explants were cultured up to three weeks in the presence or absence of estradiol (E2), medroxyprogesterone acetate (MPA), testosterone (T), dihydrotestosterone (DHT) and SERMs - ospemifene (OSP), raloxifene (RAL) and tamoxifen (TAM). The cultured HBTs maintained morphological integrity and responded to hormonal treatment in vitro. E2, MPA or E2/MPA increased proliferative activity and was associated with increased cyclin-D1 and caused changes in the cell cycle inhibitors p21 and p27, whereas the androgens T and DHT inhibited proliferation and increased apoptosis in HBT epithelia and opposed E2-stimulated proliferation and cell survival. The postm-HBTs were more sensitive to E2 than prem-HBTs. The effects of OSP, RAL and TAM on HBT epithelium were antiproliferative. E2, androgens and SERMs were associated with marked changes in the proportions of epithelial cells expressing steroid hormone receptors: E2 increased ERα expressing cells and decreased androgen receptor (AR) positive cells, whereas T and DHT had opposite effects. The OSP, RAL and TAM, also decreased a proportion of ERα positive cells in HBT epithelium. At 100 nM, these compounds maintained the relative number of AR positive cells, present at control level, which may partly explain proliferative inhibition. In conclusion, the proliferative activity of E2, in the epithelium of postm-HBTs, is opposed by T and DHT, which suggests that the inclusion of androgens in MHT may decrease the risk for developing BC.Estradiolin, androgeenin ja selektiivisten estrogeenireseptorin muuntelijoiden (SERM), ospemifeenin, raloksifeenin ja tamoksifeenin vaikutus ihmisen rintakudokseen Vaihdevuosien hormonihoito (VHH) sisältää tyypillisesti estrogeenia, usein yhdistettynä keltarauhashormoniin tai androgeeniin. Hoidoilla on myönteinen vaikutus vaihdevuosioireisiin, luun tiheyteen ja rasva-aineenvaihduntaan, mutta VHH:n mahdollinen rintasyöpäriskiä lisäävä vaikutus on edelleen kiistanalainen ja aihetta koskevat tutkimusraportit ovat tuottaneet ristiriitaista tietoa. Tämän tutkimuksen tarkoituksena oli selvittää vaihdevuosien hormonihoidossa (VHH:ssa) käytettyjen hormonien ja muiden yhdisteiden vaikutusta ihmisen normaaliin maitorauhaskudokseen. Tutkimuksessa käytettiin kudosviljelymallia, jossa tutkittiin estrogeenin, keltarauhashormonin (medroksiprogesteroni-asetaatti, MPA), androgeenin (testosteroni, T ja dihydrotestosteroni, DHT) ja kolmen selektiivisen estrogeenireseptorin muuntelijan (SERM), ospemifeenin (OSP), raloksifeenin (RAL) ja tamoksifeenin (TAM) rintakudosvaikutuksia ihmisten rmaitorauhaskudokseen. Maitorauhaskudosta viljeltiin hormonien ja SERM- yhdisteiden kanssa 14-21 päivää. Tulokset osoittavat, että rintakudos säilyttää viljelyssä hormonivasteensa kuten E2:n aiheuttaman ER-spesifisten kohdegeenien (amfireguliini ja TFF1) sekä androgeenien aiheuttaman kohdegeenien (apolipoproteiini-D ja prostataspesifinen antigeeni, PSA) induktion. E2, MPA tai E2/MPA lisäsivät rintaepiteelisolujen proliferaatiota, kun taas androgeenit T ja DHT estivät sitä ja lisäsivät solukuolemaa. Ne myös vähensivät E2:n stimuloivaa vaikutusta proliferaatioon. Postmenopausaalisten naisten rintakudos oli yleisesti herkempi hormonihoidoille kuin premenopausaalisten naisten maitorauhasrintakudos. SERM-yhdisteet OSP, RAL ja TAM vähensivät maitorauhasen epiteelisolujen proliferaatiota pitoisuudesta riippuvalla tavalla. E2-, androgeeni- ja SERM-käsittelyihin liittyi voimakkaita muutoksia rintaepiteelien ER- ja ARreseptorien tasoissa ja vaikutusta välittävissä tekijöissä, mitkä selittänevät osaltaan yhdisteiden vaikutuksia. Yhteenvetona voi todeta, että androgeenit estävät maitorauhasen epiteelisolujen proliferaatiota sekä estrogeenin aiheuttamaa stimulaatiota ja siihen liittyvää rintasyöpäriskin lisääntymistä. Postmenopausaalisten naisten hormonihoitoihin suunnitellut SERM-yhdisteet OSP ja RAL estivät normaalin rintaepiteelin proliferaatiota lähes rintasyöpälääkkeenä käytettävään tamoksifeeniin verrattavalla tavalla. Tuloksilla on merkitystä vaihdevuosien hormonihoitojen kehitetyksessä.Siirretty Doriast

Anatomical and Histological Study of the Mammary Gland of the Guinea Pig (Cavia porcellus) in the Andean and Peruvian Races

El objetivo del estudio fue analizar anatómica e histológicamente la glándula mamaria del cuy. Para el estudio descriptivo de las glándulas mamarias se utilizaron 16 cuyes hembras divididos en 2 grupos: 8 cuyes de raza Perú y 8 cuyes de raza Andina. Cada grupo se dividió en subgrupos conformados por: 2 cuyes de 8 semanas de edad, 3 de 21 semanas de edad y 3 de 34 semanas de edad. En ellos se evaluó la conformación microscópica y macroscópica de las estructuras que conformaban la glándula mamaria del cuy, sus modificaciones y características influenciadas por la edad. Para la evaluación histológica se realizaron 33 láminas en las cuales se estudiaron muestras de la porción glandular secretora y el pezón. En la porción glandular se observó la conformación de los lóbulos y lobulillos mamarios que se encontraban en diferentes etapas del proceso secretor; en el pezón se encontró un epitelio estratificado plano queratinizado y también el predominio el tejido conjuntivo denso irregular. La evaluación anatómica mostró una forma discoidal conformada por 2 ejes (eje mayor con dirección cráneo lateral y eje menor). Estas se ubicaban en posición inguinal relacionada con la cara medial del muslo y de superficie lobulada. El pezón se encontró situado en el cuadrante posterior derecho de la glándula mamaria y mostró una posición vertical, recta y flexible

Progesterone influence on gerbil (Meriones unguiculatus) prostate : interactions with estrogen and testosterone

Orientador: Sebastião Roberto TabogaTese (doutorado) - Universidade Estadual de Campinas, Instituto de BiologiaResumo: A próstata, glândula do sistema genital que tem origem embrionária a partir do seio urogenital, não é exclusiva do sistema reprodutor masculino, sendo também encontrada em fêmeas de vários mamíferos, incluindo humanos e roedores. No macho ela pode apresentar-se altamente desenvolvida em razão da maior quantidade do hormônio testosterona, e, apesar de pouco desenvolvida em fêmeas, devido à baixa quantidade desse mesmo tipo hormonal, é uma glândula funcional. Em fêmeas adultas de gerbilos, a próstata possui uma localização parauretral, exibindo íntimo contato com a parede proximal e medial da uretra, a qual é homóloga a próstata ventral de roedores machos. Embora se conheça a influência da progesterona na fisiologia do sistema reprodutor feminino e masculino, poucos estudos exploram a sua influência, especificamente, sobre a glândula prostática. Desta forma, este trabalho avaliou os aspectos morfofuncionais da glândula prostática masculina e feminina, resultantes da influência da progesterona, e de suas interações com o estradiol e a testosterona. Para isso, gerbilos machos e fêmeas foram castrados cirurgicamente no início do período puberal, aos 45 dias de idade. Ao completarem 90 dias de idade, os gerbilos receberam doses subcutâneas de progesterona ou desse somado a estradiol e testosterona, durante 14 dias. Nos animais castrados de ambos os sexos a próstata mostrou uma morfologia regredida, com uma redução significativa na sua capacidade de secreção, da quantidade de células receptoras de androgênio (AR) e receptoras de estrógeno ? (ER?), porém sem alterar a marcação para receptor de estrógeno ? (ER?). Dessa forma, a castração cirúrgica foi bastante importante, uma vez que permitiu mimetizar de forma satisfatória um ambiente prostático com baixos níveis hormonais. Nos dois sexos, a administração de progesterona isoladamente conseguiu reverter alguns desses efeitos, com uma melhora considerável no padrão secretório da glândula, porém estruturalmente essas mudanças ocorreram de forma moderada. Nesses animais, foi observado um aumento expressivo dos ERs ? e ?, além da presença de células receptoras de progesterona (PR). Em relação aos ARs foi evidenciado que a progesterona pode apresentar características indutoras ou inibitórias dependendo da sua concentração. O tratamento, simultâneo com a progesterona, de estradiol e testosterona desencadeou uma reestruturação glandular mais intensa nos machos e fêmeas, resultando em hipertrofia e hiperplasia do epitélio e do estroma glandular, recuperação do padrão de secreção e amplitude alveolar. Essas características, no entanto, foram acompanhadas pelo surgimento de lesões prostáticas como neoplasias intraepiteliais e o surgimento de debris celulares. A interação da progesterona com o estradiol também regulou positivamente os AR, ER? e ER?, porém não apresentou qualquer efeito sobre os PRs quando comparado aos animais tratados somente com progesterona. Em adição, nesses animais houve um aumento acentuado da proliferação celular, o qual foi contrabalanceado pelo aumento também do índice de morte celular. Nos animais tratados com progesterona e testosterona, a próstata também se desenvolveu e mostrou um aumento das células AR-positivas e do índice apoptótico, havendo, entretanto uma redução dos ER?, ER? e PR. Dessa forma, é razoável concluir que a próstata feminina e masculina comporta-se de forma bastante semelhante frente à ação dos hormônios progesterona, estradiol e testosterona. Ademais, embora a progesterona apresente efeitos estruturais razoáveis na glândula prostática, a sua interação com o estrógeno e a testosterona é capaz de promover uma intensificação desses efeitos, sem recriar, porém um ambiente homeostático semelhante aos dos animais intactos. A progesterona também mostrou ser um fator regulador em potencial da atividade proliferativa e apoptótica prostática, opondo-se aos efeitos da testosterona e do estradiol. Outro fator importante é a descoberta de que a progesterona pode induzir ou inibir a presença de células AR-positivas na glândula, e que esse dualismo funcional é resultado do efeito dose-dependente desse hormônio sobre a próstataAbstract: The prostate is a gland of reproductive system that arises from the urogenital sinus, being located around the urethra below the bladder. The existence of this gland is not exclusive of the male reproductive system, being found in females of various species, including rodents and humans. In the male, it can be highly developed due to the increased amount of the testosterone, and although poorly developed in females, due to the low quantity of this hormone, it is a functional gland. The prostate of female gerbils has a paraurethral location, showing a closer contact with the proximal and medial urethra wall, being homologous to the ventral prostate of male rats. This study evaluates the morphofunctional aspects of the prostate gland in males and females, regarding the influence of progesterone, and their interactions with estradiol and testosterone. For this, male and female gerbils were surgically castrated in early pubertal period, at 45 days of age. At 90 days of age, the gerbils received subcutaneous doses of progesterone alone or associated to testosterone or estradiol during 14 days. In castrated animals of both sexes, prostate showed a regressed morphology, with a significant reduction in its secretion capacity, the amount of androgen receptor cells (AR) and estrogen receptor ? (ER?), but without changing the labeling for estrogen receptor ? (ER?). Thereby, surgical castration was very important, since it allowed mimetize a prostatic environment with low hormone levels. In both sexes, the administration of progesterone alone could reverse some of these effects with a considerable secretion improvement, but structurally these changes occurred in a moderate way. In these animals, we observed a significant increase of ER ? and ?, besides the presence of progesterone receptor (PR) cells. Regarding ARs, it was shown that progesterone can have inductor or inhibitory characteristics depending on its concentration. The treatment with progesterone plus estradiol and progesterone plus testosterone triggered a more intense prostate restructuration in male and female, resulting however in a hypertrophy and hyperplasia of the glandular epithelium and stroma, besides recovery of the alveoli amplitude and pattern of cellular secretion. These characteristics, however, were followed by the development of prostatic lesions like intraepithelial neoplasia and cellular desquamation. The progesterone and estradiol interaction also upregulated the AR, ER? and ER?, however had no effect on the PRs when compared to the animals treated with progesterone alone. In addition, in these animals there was a marked increase in cellular proliferation, which was counterbalanced by increased cell death. In animals of either sex treated with progesterone and testosterone, the prostate also became developed and showed an increase of AR-positive cells and apoptotic index, although there was a reduction of ER?, ER? and PR. Thus, it is reasonable to conclude that the female and male prostate behaves similarly after the progesterone, estradiol and testosterone administration. Moreover, although the progesterone has reasonable structural effects on the prostate gland, its interaction with estrogen and testosterone can intensificate these effects, but do not recover a homeostatic environment similar to that of intact animals. The progesterone also proved to be a potential regulatory factor of the proliferative and apoptotic activity, opposing the effects of testosterone and estradiol. Another important finding is that progesterone can induce or inhibit the presence of ARpositive cells in the gland, and this functional dualism is the result of dose-dependent effect of this hormone on the prostateDoutoradoBiologia CelularDoutor em Biologia Celular e Estrutura

Neuroanatomical and gene expression features of the rabbit accessory olfactory system. Implications of pheromone communication in reproductive behaviour and animal physiology

Mainly driven by the vomeronasal system (VNS), pheromone communication is involved in many species-specific fundamental innate socio-sexual behaviors such as mating and fighting, which are essential for animal reproduction and survival. Rabbits are a unique model for studying chemocommunication due to the discovery of the rabbit mammary pheromone, but paradoxically there has been a lack of knowledge regarding its VNS pathway. In this work, we aim at filling this gap by approaching the system from an integrative point of view, providing extensive anatomical and genomic data of the rabbit VNS, as well as pheromone-mediated reproductive and behavioural studies. Our results build strong foundation for further translational studies which aim at implementing the use of pheromones to improve animal production and welfare

Stromal-Epithelial Interactions during Mammary Gland Development

Mammary gland is an organ, which undergoes the majority of its development in the postnatal life of mammals. The complex structure of the mammary gland comprises epithelial and myoepithelial cells forming the parenchymal tissue and adipocytes, fibroblasts, vascular endothelial cells, and infiltrating immune cell composing the stromal compartment. During puberty and in adulthood, circulating hormones released from the pituitary and ovaries regulate the rate of development and functional differentiation of the mammary epithelium. In addition, growing body of evidence shows that interactions between the stromal and parenchymal compartments of the mammary gland play a crucial role in mammogenesis. This regulation takes place on a paracrine level, by locally synthesized growth factors, adipokines, and cytokines, as well as via direct cell-cell interactions. This chapter summarizes the current knowledge about the complex nature of interactions between the mammary epithelium and stroma during mammary gland development in different mammalian species

Sexual Differentiation of the Reproductive System in the Marsupial Monodelphis domestica

This study, on testis development and descent, reproductive tract development and the sex steroid hormones in the grey short-tailed opossum, Monodelphis domestica, investigates sex differentiation in this important biomedical model