RESUMEN
In the present work, we described the expression and activity of extracellular signal-related kinases 1-2 (ERK1-2) in mouse primordial germ cells (PGCs) from 8.5-14.5 days post coitum (dpc) and investigated whether these kinases play a role in regulating the various processes of PGC development. Using immunofluorescence and immunoblotting to detect the active phosphorylated form of ERK1-2 (p-ERK1-2), we found that the kinases were present in most proliferating 8.5-10.5 dpc PGCs, low in 11.5 dpc PGCs, and progressively increasing between 12.5-14.5 dpc both in female and male PGCs. In vitro culture experiments showed that inhibiting activation of ERK1-2 with the MEK-specific inhibitor U0126 significantly reduced the growth of 8.5 dpc PGCs in culture but had little effect on 11.5-12.5 dpc PGCs. Moreover, we found that the inhibitor did not affect the adhesion of 11.5 dpc PGCs, but it significantly reduced their motility features onto a cell monolayer. Further, while the ability of female PGCs to begin meiosis was not significantly affected by U0126, their progression through meiotic prophase I was slowed down. Notably, the activity of ERK1-2 was necessary for maintaining the correct expression of oocyte-specific genes crucial for germ cells survival and the formation of primordial follicles.
Asunto(s)
Células Germinativas/citología , Proteína Quinasa 1 Activada por Mitógenos/biosíntesis , Proteína Quinasa 3 Activada por Mitógenos/biosíntesis , Animales , Butadienos/farmacología , Ciclo Celular , Diferenciación Celular , Movimiento Celular , Proliferación Celular , Cartilla de ADN/genética , Inhibidores Enzimáticos/farmacología , Femenino , Perfilación de la Expresión Génica , Técnicas In Vitro , Masculino , Meiosis , Profase Meiótica I , Ratones , Ratones Transgénicos , Microscopía Confocal , Microscopía Fluorescente , Nitrilos/farmacología , Oocitos/metabolismo , Oogénesis/genética , Folículo Ovárico/citología , Ovario/metabolismoRESUMEN
The transcription factor p63 mediates distinct cellular responses, primarily regulating epithelial and oocyte biology. In addition to the two amino terminal isoforms, TAp63 and ΔNp63, the 3'-end of p63 mRNA undergoes tissue-specific alternative splicing that leads to several isoforms, including p63α, p63ß and p63γ. To investigate in vivo how the different isoforms fulfil distinct functions at the cellular and developmental levels, we developed a mouse model replacing the p63α with p63ß by deletion of exon 13 in the Trp63 gene. Here, we report that whereas in two organs physiologically expressing p63α, such as thymus and skin, no abnormalities are detected, total infertility is evident in heterozygous female mice. A sharp reduction in the number of primary oocytes during the first week after birth occurs as a consequence of the enhanced expression of the pro-apoptotic transcriptional targets Puma and Noxa by the tetrameric, constitutively active, TAp63ß isoform. Hence, these mice show a condition of ovary dysfunction, resembling human primary ovary insufficiency. Our results show that the p63 C-terminus is essential in TAp63α-expressing primary oocytes to control cell death in vivo, expanding the current understanding of human primary ovarian insufficiency.
Asunto(s)
Infertilidad Femenina/genética , Oocitos/patología , Insuficiencia Ovárica Primaria/genética , Transactivadores/genética , Empalme Alternativo/genética , Animales , Apoptosis/genética , Proteínas Reguladoras de la Apoptosis/genética , Células Cultivadas , Modelos Animales de Enfermedad , Exones/genética , Femenino , Heterocigoto , Humanos , Infertilidad Femenina/patología , Masculino , Ratones , Mutación , Cultivo Primario de Células , Insuficiencia Ovárica Primaria/complicaciones , Insuficiencia Ovárica Primaria/patología , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Proteínas Proto-Oncogénicas c-bcl-2/genética , Transactivadores/metabolismo , Activación Transcripcional , Proteínas Supresoras de Tumor/genéticaRESUMEN
Performance in everyday spatial orientation tasks (e.g., map reading and navigation) has been considered functionally separate from performance on more abstract object-based spatial abilities (e.g., mental rotation and visualization). However, few studies have examined the link between spatial orientation and object-based spatial skills, and even fewer have done so including a wide range of spatial tests. To examine this issue and more generally to test the structure of spatial ability, we used a novel gamified battery to assess six tests of spatial orientation in a virtual environment and examined their association with ten object-based spatial tests, as well as their links to general cognitive ability (g). We further estimated the role of genetic and environmental factors in underlying variation and covariation in these spatial tests. Participants (N = 2660; aged 19-22) were part of the Twins Early Development Study. The six tests of spatial orientation clustered into a single 'Navigation' factor that was 64% heritable. Examining the structure of spatial ability across all 16 tests, three, substantially correlated, factors emerged: Navigation, Object Manipulation, and Visualization. These, in turn, loaded strongly onto a general factor of Spatial Ability, which was highly heritable (84%). A large portion (45%) of this high heritability was independent of g. The results point towards the existence of a common genetic network that supports all spatial abilities.
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Following publication of their article, the authors reported that the name of the fifth author had been formatted incorrectly in PubMed. Instead of "Rella FD" it should be "Di Rella F".
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In vitro culture models were used to characterize the effects of chemotherapeutic drugs and of LH on somatic cells from prepuberal mouse ovaries. All cell types (pre- and granulosa cells, pre-thecal and OSE cells) underwent apoptosis following Epirubicin (0.5µM) exposure for 24hrs (about 60%) and 48hrs (>80%). Cisplatin (10µM) and the Cyclophosphamide active metabolite, Phosphoramide Mustard (10µM), didn't cause apoptosis in 90% of pre-thecal and pre-granulosa cells up to 72hrs of exposure, although they suffered extensive DNA damage and cell cycle arrest, and acquired stress induced premature senescence (SIPS) features. Cultured granulosa cells didn't show evident DNA damage and remained viable without acquiring SIPS features; OSE cells were resistant to apoptosis and SIPS but not to DNA damage. These latter, like pre-thecal and pre-granulosa cells, were able of efficient DNA repair involving MLH1-dependent MMR pathways. SIPS features were also observed in ovary after in vivo treatment with Cisplatin. LH (200mIU/mL) didn't significantly influence apoptosis, SIPS and DNA damage but favoured DNA repair. These results show that somatic cells of prepuberal ovary response to drugs in different ways, either undergoing apoptosis or SIPS, either showing resistance to Cisplatin and Phosphoramide Mustard. Moreover, a new role of LH in promoting DNA repair was shown.
Asunto(s)
Antineoplásicos/toxicidad , Cisplatino/toxicidad , Ciclofosfamida/toxicidad , Epirrubicina/toxicidad , Células de la Granulosa/efectos de los fármacos , Células Tecales/efectos de los fármacos , Animales , Apoptosis/efectos de los fármacos , Senescencia Celular/efectos de los fármacos , Femenino , RatonesRESUMEN
During a woman's reproductive life, only about 400 primordial follicles will develop into a preovulatory follicle and undergo ovulation, releasing an oocyte available for fertilization. The process of formation and selection of these follicles is complex and involves a multistep process characterized by a balance between survival and death of the oocytes and the surrounding follicular cells. Although the mechanisms underlying such process are not completely clarified yet, it is common idea that they can occur through various types of programmed cellular death (PCD). Since atresia is the principal destiny of the ovarian follicles, it is relevant to understand how this process takes place and how it is regulated. In this review, after a summary description of folliculogenesis in humans, the main mechanisms of atresia reported to occur during folliculogenesis from birth to adult age, in the human ovary and in other mammals when appropriate, are described.
Asunto(s)
Oocitos/citología , Folículo Ovárico/fisiología , Ovario/fisiología , Adulto , Animales , Apoptosis/fisiología , Muerte Celular/fisiología , Femenino , Atresia Folicular/fisiología , Humanos , Ovulación/fisiologíaRESUMEN
The survival rate of cancer patients is steadily increasing, owing to more efficient therapies. Understanding the molecular mechanisms of chemotherapy-induced premature ovarian insufficiency (POI) could identify targets for prevention of POI. Loss of the primordial follicle reserve is the most important cause of POI, with the p53 family member p63 being responsible for DNA-damage-induced apoptosis of resting oocytes. Here, we provide the first detailed mechanistic insight into the activation of p63, a process that requires phosphorylation by both the priming kinase CHK2 and the executioner kinase CK1 in mouse primordial follicles. We further describe the structural changes induced by phosphorylation that enable p63 to adopt its active tetrameric conformation and demonstrate that previously discussed phosphorylation by c-Abl is not involved in this process. Inhibition of CK1 rescues primary oocytes from doxorubicin and cisplatin-induced apoptosis, thus uncovering a new target for the development of fertoprotective therapies.
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Quinasa de la Caseína I/metabolismo , Quinasa de Punto de Control 2/metabolismo , Daño del ADN , Oocitos/enzimología , Factores de Transcripción/metabolismo , Proteínas Supresoras de Tumor/metabolismo , Animales , Quinasa de la Caseína I/antagonistas & inhibidores , Línea Celular Tumoral , Cisplatino/toxicidad , Doxorrubicina/toxicidad , Humanos , Ratones , Oocitos/efectos de los fármacos , Oocitos/metabolismo , Fosforilación , Multimerización de ProteínaRESUMEN
Premature ovarian failure and female infertility are frequent side effects of anticancer therapies, owing to the extreme sensitivity of the ovarian reserve oocytes to the damaging effects of irradiation and chemotherapy on DNA. We report here a robust protective effect of luteinizing hormone (LH) on the primordial follicle pool of prepubertal ovaries against the cisplatin (Cs)-induced apoptosis. In vitro LH treatment of prepubertal ovarian fragments generated anti-apoptotic signals by a subset of ovarian somatic cells expressing LH receptor (LHR) through cAMP/PKA and Akt pathways. Such signals, reducing the oocyte level of pro-apoptotic TAp63 protein and favoring the repair of the Cs-damaged DNA in the oocytes, prevented their apoptosis. Noteworthy, in vivo administration to prepubertal female mice of a single dose of LH together with Cs inhibited the depletion of the primordial follicle reserve caused by the drug and preserved their fertility in reproductive age, preventing significant alteration in the number of pregnancy and of delivered pups. In conclusion, these findings establish a novel ovoprotective role for LH and further support the very attracting prospective to use physiological 'fertoprotective' approaches for preventing premature infertility and risks linked to precocious menopause in young patients who survived cancer after chemotherapy.
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Apoptosis/efectos de los fármacos , Cisplatino/toxicidad , Hormona Luteinizante/farmacología , Androstadienos/farmacología , Animales , Células Cultivadas , Cromonas/farmacología , AMP Cíclico/metabolismo , Proteínas Quinasas Dependientes de AMP Cíclico/metabolismo , Daño del ADN/efectos de los fármacos , Femenino , Fertilidad/efectos de los fármacos , Hormona Folículo Estimulante/farmacología , Ratones , Ratones Transgénicos , Morfolinas/farmacología , Oocitos/citología , Oocitos/efectos de los fármacos , Oocitos/metabolismo , Folículo Ovárico/citología , Folículo Ovárico/efectos de los fármacos , Folículo Ovárico/metabolismo , Fosfoproteínas/metabolismo , Proteínas Proto-Oncogénicas c-akt/antagonistas & inhibidores , Proteínas Proto-Oncogénicas c-akt/metabolismo , Receptores de HL/metabolismo , Transducción de Señal , Transactivadores/metabolismo , WortmaninaRESUMEN
From previous and more recent works reviewed in the present paper, it appears that mammalian fetal oocytes face several challenges to survive throughout the stages of meiotic prophase I up to the block at the diplotene/dictyate stage and the primordial follicle assembly. Depending on the period of development and experimental conditions, these oocytes can undergo different forms of programmed cell death (PCD) and cross-talking pathways. We hypothesize that they require the continuous support of growth factors to accomplish the activities required to overcome PCD during prophase I. An extraordinary level of DNA double strand break (DSB) tolerance characterizes oocytes during the first stages of meiotic prophase I. However, the activation of a p63/p53-and PCNA-dependent DNA damage checkpoint, plays a major role in eliminating defective oocytes when they reach the diplotene stage. Before oocytes are enclosed into a primordial follicle, the shortness of nutrients/growth factors might activate protective autophagy but this can turn into their death if starvation is prolonged. Actually, clarifying the relationships among growth factor signalling (mainly AKT cascade), apoptotic and autophagic proteins that seem to coexist in fetal oocytes, could be the key to understanding PCD in these cells.
Asunto(s)
Apoptosis/fisiología , Oocitos/crecimiento & desarrollo , Oogénesis/fisiología , Folículo Ovárico/embriología , Ovario/embriología , Animales , Autofagia/fisiología , Daño del ADN/genética , Femenino , Mamíferos/embriología , Oocitos/citología , Ovario/citología , Antígeno Nuclear de Célula en Proliferación/metabolismo , Factores de Transcripción/metabolismo , Proteína p53 Supresora de Tumor/metabolismo , Proteínas Supresoras de Tumor/metabolismoRESUMEN
[reaction: see text] A series of new crown ethers, incorporating a malonate ester functionality, have been synthesized and derivatized with pi-electron rich aldehydes to give, conjugated, extended "push-pull" compounds. Their ability to bind Lewis acid-like metal cations, such as Mg(2+) and Eu(3+), has been characterized, and the relative stability constants are presented. When the metal cation is bound to the malonate moiety within the crown ether cavity, the D-pi-A character of the molecular structure is greatly enhanced.
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The aim of the study was to investigate the clinical features, including survival, of patients with colorectal malignancies developed at a very early age (≤40 years), together with possible factors involved in the pathogenesis of these rare neoplasms. The study took advantage of the existence of a specialized colorectal cancer Registry active from 1984. 57 patients met the criteria of early onset cancer; main epidemiological data, morphology, stage, familial aggregation, possible role of inheritance and survival were analyzed. Despite the relevant increase over time of all registered patients, joiningpoint analysis of crude incidence rate of early onset colorectal neoplasms revealed a certain stability of these tumors (EAPC: 2.4, CI 14-22) with a constant prevalence of the male sex. Stage at diagnosis did not show significant variations between early onset and maturity onset colorectal neoplasms. Hereditary as well as familial cases were significantly (P < 0.005 and 0.03) more frequent among patients with early onset tumors, although in the majority of them no specific etiological factor could be identified. Survival was more favorable in patients with early onset tumors, though this had to be attributed to the higher presence of some histological types in early onset cases. Survival was significantly more favorable for patients of all ages registered in the last decade. Incidence of early onset colorectal cancer was relatively stable between 1984 and 2008. A male preponderance was evident through the registration period. Hereditary and familial cases were significantly more frequent among early onset case. A well defined etiology could be observed in 16% of the cases (versus 2-3% in older individuals). Five-year survival showed a significant improvement over time.