Metformin improves polycystic ovary syndrome and activates female germline stem cells in mice / 生理学报

Polycystic ovary syndrome (PCOS) is a common disease caused by complex endocrine and metabolic abnormalities in women of childbearing age. Metformin is the most widely used oral hypoglycemic drug in clinic. In recent years, metformin has been used in the treatment of PCOS, but its mechanism is not clear. In this study, we aimed to investigate the effect of metformin on PCOS and its mechanism through PCOS mouse model. Female C57BL/6J mice aged 4-5 weeks were intragastrically given letrozole (1 mg/kg daily) combined with a high-fat diet (HFD) for 21 days to establish the PCOS model. After modeling, metformin (200 mg/kg daily) was intragastrically administered. One month later, the body weight and oral glucose tolerance test (OGTT) were measured. Hematoxylin eosin (H&E) staining was used to detect the pathological changes of ovary. The serum levels of anti-Mullerian hormone (AMH), follicle-stimulating hormone (FSH), luteinizing hormone (LH), E2 and testosterone (T) were measured by ELISA. The expression of DDX4/MVH was detected by immunohistochemistry. DDX4/MVH and PCNA were co-labeled by immunofluorescence. The protein levels of DDX4/MVH, PCNA, cyclin D2, AMPK and mTOR were detected by Western blot. The results showed that after metformin treatment, the body weights of PCOS mice were gradually returned to normal, glucose tolerance was significantly improved, serum E2 levels were increased, while AMH, LH, T levels and LH/FSH ratio were decreased. Ovarian polycystic lesions were reduced with reduced atresia follicles. Furthermore, the number of proliferative female germline stem cells (FGSCs) and levels of proliferation related proteins (PCNA, cyclin D2) were significantly increased, and the p-mTOR and p-AMPK levels were markedly up-regulated. These results suggest that metformin treatment not only improves hyperandrogenemia, glucose intolerance and polycystic ovarian lesions in PCOS, but also activates the function of FGSCs. The underlying mechanism may be related to the phosphorylation of AMPK and mTOR. These findings provide new evidence to use metformin in the treatment of PCOS and follicular development disorder.

Expression relationship of Hippo signaling molecules and ovarian germline stem cell markers in the ovarian aging process of women and mice / 生理学报

The present study was aimed to investigate the expression relationship of Hippo signaling molecules and ovarian germline stem cell (OGSC) markers in the development schedule of OGSCs during ovarian aging in women and mice. The ovaries of 2-month-old mature (normal control) and 12-month-old (physiological ovarian aging) KM mice were sampled, and the ovarian cortex samples of young (postpuberty to 35 years old), middle age (36-50 years old) and menopausal period (51-60 years old) women were obtained with consent. The mice model of pathological ovarian aging was established by intraperitoneal injection of cyclophosphamide/busulfan (CY/BUS). HE staining was used to detect the changes of follicles at different stages, and the localization and expression changes of Hippo signaling molecules and OGSCs related factors (MVH/OCT4) were detected by immunohistochemistry and immunofluorescence staining. Western blot was used to detect the protein expression levels of the major molecules in the Hippo signaling pathway and OGSCs related factors. The results showed that there were not any normal follicles, but a few atresia follicles in the ovaries from physiological and pathological ovarian aging mice. Compared with the normal control mice, both the physiological and pathological ovarian aging mice showed decreased protein expression levels of the main Hippo signaling molecules (pYAP1) and MVH/OCT4; Whereas only the pathological ovarian aging mice showed increased ratio of pYAP1/YAP1. In comparison with the young women, the middle age and menopausal women showed looser structure of ovarian surface epithelium (OSE) and less ovarian cortical cells. The protein expression level of LATS2 in the OSE was the highest in young women, MST1 expression was the lowest in the menopausal period women, and the expression levels of YAP1 and pYAP1 were the highest in middle age women. Compared with the young women, the middle age and menopausal period women exhibited significantly decreased ratio of OSE pYAP1/YAP1, whereas there was no significant difference between them. The expression level of MVH protein in OSE from the young women was significantly higher than those of the middle age and menopausal period women. These results indicate that there is an expression relationship between the main molecules of Hippo signaling pathway and OGSCs related factors, which suggests that Hippo signaling pathway may regulate the expression levels of OGSCs related factors, thus participating in the process of physiological and pathological degeneration of ovarian.

Aplicaciones méiicas de las células pluripotentes inducidas paciente-específicas / Medical applicaiions of induced pluripotent cells specific-patient / Aplicações méicaas das células pluripotentes induzidas paciente-específicas

Los recientes avances en la implementación de estrategias de reprogramación genética en células somáticas para la producción de células pluripotentes inducidas (iPS), abren la posibilidad de generar células pluripotentes para estudios del desarrollo embrionario y la diferenciación celular, herramientas para detección in vitro de nuevos medicamentos y evaluación de su eficacia y toxicidad, desarrollo de modelos in vitro de enfermedades humanas y uso en terapia celular. Las iPS, son células que muestran características fenotípicas y funcionales similares a las observadas en células madre embrionarias, sin los cuestionamientos éticos y legales de la manipulación de embriones. En particular, la generación de las células pluripotentes inducidas paciente-específicas ha permitido dilucidar los procesos fisiopatológicos de diversas enfermedades genéticas de etiología conocida y desconocida, así como plantean la posibilidad de realizar terapia celular autóloga y terapia génica basada en células para la regeneración tisular dependiendo de las necesidades individuales.

Recent advances in the implementation of strategies of genetic reprogramming somatic cells to produce induced pluripotent cells (iPS), open the possibility of generating pluripotent cells for studies of embryonic development and cell differentiation, tools for in vitro detection of new drugs and evaluation of their efficacy and toxicity, in order to develop in vitro models of human disease and use in cell therapy. iPS cells are showing phenotypic and functional characteristics similar to those seen in embryonic stem cells, without the ethical and legal questionings of the experimental manipulation of embryos. In particular, generation of patient-specific pluripotent stem cells elucidate the pathophysiological processes of various genetic diseases of known and unknown aetiology, and raises the possibility of autologous cell therapy and cell-based gene therapy for tissue regeneration depending individual needs.

Os recentes avanços na implementação de estratégias de reprogramação genética em células somáticas para a produção de células pluripotentes induzidas (iPS), abrem a possibilidade de gerar células pluripotentes para estudos do desenvolvimento embrionário e a diferenciação celular, ferramentas para detecção in vitro de novos medicamentos e avaliação da sua eficácia e toxicidade, desenvolvimento de modelos in vitro de doenças humanas e uso em terapia celular. As iPS, são células que mostram características fenotípicas e funcionais similares às observadas em células tronco embrionárias, sem os questionamentos éticos e legais da manipulação de embriões. Em particular, a geração das células pluripotentes induzidas paciente-específicas tem permitido elucidar os processos fisiopatológicos de diversas doenças genéticas de etiologia conhecida e desconhecida, assim como estabelecem a possibilidade de realizar terapia celular autóloga e terapia gênica baseada em células para a regeneração tecidual dependendo das necessidades individuais.

Considerações e questionamentos sobre as evidências da ovogênese pós-natal em mamíferos / Considerations and questionaments about evidence of post-natal ovogenesis in mammalian

É apresentada uma revisão de literatura sobre a origem dos ovócitos primários em ovários de fêmeas adultas de mamíferos. Apesar de ser considerado um processo exclusivamente embrionário, vem se questionando a produção dessas células germinativas após o nascimento, processo denominado neo-ovogênese. Diferentes estudos vêm sendo apresentados para demonstrar a ocorrência da nova teoria, como a existência de células-tronco germinativas no epitélio do ovário ou de células-tronco de medula óssea. Dessa forma, é importante o estudo da neo-ovogênese, já que a mesma poderá proporcionar um benefício inigualável para a área de reprodução assistida.

A literature review about the origin of primary oocytes in ovaries of female adult mammals is shown. Although it was considered only an embryonic process, the production of the germ cells after birth has been questionated, a process called neoovogenesis... Different studies have been shown to prove the occurrence of this new theory, like the existence of germ stem cells in ovarian germ epithelial or stem cells from bone marrow. Like this, it is important to study the neoovogenesis, since it may provide a unique benefit to the area of assisted reproduction.