RESUMO
Frizzled 3 is an important receptor in the Wnt/ß-catenin pathway, a conserved signaling pathway that regulates gene expression and controls diverse developmental processes. However, the role of this protein during follicular development in the adult ovary is not known. The present study was designed to investigate the expression and localization of Frizzled 3 mRNA and protein during the estrous cycle in the mouse ovary through in situ hybridization (ISH), real-time quantitative polymerase chain reaction, immunohistochemistry and western blot. ISH results showed that in proestrus, high expression of Frizzled 3 was found in the granulosa and stroma with weak levels in the corpus luteum. In estrus and diestrus, the stroma had high Frizzled 3 expression, but levels were low in granulosa cells and corpus luteum. In the metestrus, moderate expression of Frizzled 3 was found in the stroma but low to no expression was found in luteal cells and follicles. The mRNA and protein levels of Frizzled 3 were found to be the highest in proestrus and diestrus compared to estrus and metestrus (P < 0.05), confirming the ISH results. During estrus and diestrus, high Frizzled 3 expression was observed in the stroma and moderate levels in granulosa cells, and during estrus and proestrus, low expression was seen in the oocyte cell membrane. The western blot results further confirmed this change during the estrous cycle. Together, these results indicate that Frizzled 3 is involved in regulating follicular development and oocyte maturation during the estrous cycle.
Assuntos
Corpo Lúteo/metabolismo , Receptores Frizzled/genética , Regulação da Expressão Gênica no Desenvolvimento , Oócitos/metabolismo , Folículo Ovariano/metabolismo , Animais , Corpo Lúteo/crescimento & desenvolvimento , Corpo Lúteo/ultraestrutura , Diestro/genética , Estro/genética , Feminino , Receptores Frizzled/metabolismo , Hibridização In Situ , Camundongos , Camundongos Endogâmicos ICR , Oócitos/crescimento & desenvolvimento , Oócitos/ultraestrutura , Folículo Ovariano/crescimento & desenvolvimento , Folículo Ovariano/ultraestrutura , Proestro/genética , Reação em Cadeia da Polimerase em Tempo Real , Fatores de TempoRESUMO
Vascular endothelial growth factor (VEGF)-dependent angiogenesis plays a crucial role in corpus luteum formation and its functional maintenance in mammalian ovaries. We recently reported that activation of hypoxia-inducible factor (HIF)-1α signaling contributes to the regulation of VEGF expression in luteal cells (LCs) in response to human chorionic gonadotropin (HCG). We examined whether HIF prolyl-hydroxylase (PHD)-2 gene silencing induces VEGF expression in LCs and enhanced its expression induced by HCG in LCs. Using real-time polymerase chain reaction and western blot analysis, we measured the expression of PHD-2 to confirm plasmid PHD-2 shRNA transfection and protein expression and investigated the changes in HIF-1a and VEGF expression after treatment with HCG and PHD-2 shRNA transfection. After PHD-2 shRNA transfection, PHD-2 expression was significantly lower than that in control groups with or without HCG treatment, while a significant increase in VEGF mRNA was observed compared to in controls, indicating that PHD-2 plays an important role in VEGF regulation. Additionally, changes in VEGF mRNA expression were consistent with the expression levels of HIF-1a protein, not HIF- 1a mRNA, which is regulated by HIF prolyl-hydroxylase-mediated degradation. Our results indicate that PHD-2 gene silencing can induce VEGF expression in LCs and HCG-induced VEGF expression can be further enhanced by PHD-2 gene silencing through an HIF-1a-mediated mechanism in LCs. This PHD-2-mediated transcriptional activation may be important for regulating VEGF expression through HIF-1a signaling in LCs during corpus luteum development in mammals.
Assuntos
Gonadotropina Coriônica/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Inativação Gênica , Prolina Dioxigenases do Fator Induzível por Hipóxia/genética , Células Lúteas/efeitos dos fármacos , Células Lúteas/metabolismo , Fator A de Crescimento do Endotélio Vascular/genética , Animais , Feminino , Expressão Gênica , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Plasmídeos/genética , Interferência de RNA , RNA Mensageiro/genética , RNA Interferente Pequeno/genética , Ratos , TransfecçãoRESUMO
The corpus luteum is a temporary endocrine structure in mammals that plays an important role in the female reproductive cycle and is formed from a ruptured and ovulated follicle with rapid angiogenesis. Vascular endothelial growth factor (VEGF) is thought to be vital in normal and abnormal angiogenesis in the ovary, but the molecular regulation of luteal VEGF expression during corpus luteum development in vivo is still poorly understood at present. Therefore, we examined whether hypoxia-inducible factor-1a (HIF-1a) is induced and regulates VEGF expression and luteal function in vivo using a pseudopregnant rat model treated with a small-molecule inhibitor of HIF-1a, echinomycin. Corpus luteum development in the pseudopregnant rat ovary was determined after measuring plasma progesterone concentration and ovarian prostaglandin F2a content to reflect changes in HIF-1a and VEGF on different days of this developmental process. At day 7, the corpus luteum was formed and the expression of HIF- 1a/VEGF reached a maximum, while a significant decrease in HIF-1a/ VEGF expression was observed when luteolysis occurred at day 13. Additionally, echinomycin blocked luteal development by inhibiting VEGF expression mediated by HIF-1a and following luteal function by detecting the progesterone changes at day 7. These results demonstrated that HIF-1a-mediated VEGF expression might be an important mechanism regulating ovarian luteal development in mammals in vivo, which may provide new strategies for fertility control and for treating some types of ovarian dysfunction, such as polycystic ovarian syndrome, ovarian hyperstimulation syndrome, and ovarian neoplasia.
Assuntos
Corpo Lúteo/crescimento & desenvolvimento , Dinoprosta/metabolismo , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Ovário/metabolismo , Progesterona/sangue , Pseudogravidez/metabolismo , Fator A de Crescimento do Endotélio Vascular/metabolismo , Animais , Corpo Lúteo/metabolismo , Manutenção do Corpo Lúteo , Feminino , Regulação da Expressão Gênica , Masculino , Gravidez , Pseudogravidez/sangue , Ratos , Ratos Sprague-Dawley , Transdução de SinaisRESUMO
Hypoxia-inducible factor-1α (HIF-1α) has been identified as a transcription factor that is involved in diverse physiological and pathological processes in the ovary. In this study, we examined whether HIF-1α is expressed in a cell- and stage-specific manner during follicular growth and development in the mammalian ovaries. Using immunohistochemistry and Western blot analysis, HIF-1α expression was observed in granulosa cells specifically and was significantly increased during the follicular growth and development of postnatal rats. Furthermore, pregnant mare serum gonadotropin also induced HIF-1α expression in granulosa cells and ovaries during the follicular development of immature rats primed with gonadotropin. Moreover, we also examined proliferation cell nuclear antigen, a cell proliferation marker, during follicular growth and development and found that its expression pattern was similar to that of HIF-1α protein. Granulosa cell culture experiments revealed that proliferation cell nuclear antigen expression may be regulated by HIF-1α. These results indicated that HIF-1α plays an important role in the follicular growth and development of these 2 rat models. The HIF-1α-mediated signaling pathway may be an important mechanism regulating follicular growth and development in mammalian ovaries in vivo.
Assuntos
Desenvolvimento Embrionário/genética , Subunidade alfa do Fator 1 Induzível por Hipóxia/biossíntese , Folículo Ovariano/crescimento & desenvolvimento , Animais , Embrião de Mamíferos , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Folículo Ovariano/metabolismo , Gravidez , Ratos , Transdução de Sinais/genéticaRESUMO
This study investigated the incidences of urinary incontinence and pelvic organ prolapse as well as pelvic floor muscle strength after cesarean section and vaginal delivery. From June 2010 to July 2011, 149 puerpera in Shenzhen Hospital, Peking University, were divided into the cesarean section group (N = 66) and the vaginal delivery group (N = 83). Postpartum urinary incontinence analysis, pelvic examination, and pelvic muscle contraction analysis using the PHENIX neuromuscular therapy instrument were performed to compare urinary incontinence, pelvic organ prolapse, and pelvic floor muscle condition between the 2 groups. The incidences of urinary incontinence in the cesarean and vaginal delivery groups were 9.09% (6/66) and 16.87% (14/83), respectively (P > 0.05); the incidences of pelvic organ prolapse were 53.03% (35/66) and 86.75% (72/83), respectively (P < 0.05). There was no significant difference in pelvic muscle pressure or electrophysiological examination results between the 2 groups (P > 0.05). Hence, cesarean section has a protective effect on early postpartum pelvic organ prolapse, but the delivery modes do not differ significantly with respect to the incidence of postpartum urinary incontinence or pelvic muscle floor muscle strength.
Assuntos
Parto Obstétrico/estatística & dados numéricos , Diafragma da Pelve/fisiologia , Prolapso de Órgão Pélvico/epidemiologia , Incontinência Urinária/epidemiologia , Adulto , Pequim/epidemiologia , Cesárea , Parto Obstétrico/métodos , Feminino , Humanos , Prolapso de Órgão Pélvico/etiologia , Período Pós-Parto , Gravidez , Incontinência Urinária/etiologiaRESUMO
Guanosine 3',5'-cyclic monophosphate (cGMP), as a second messenger, plays potential roles in ovarian functions. To elucidate the role of phosphodiesterase (PDE) in cGMP signaling during ovarian follicular development, the present study was conducted to investigate ovarian cGMP level and cGMP-PDE activity by radioimmunoassay (RIA) in postnatal rats, immature rats during gonadotropin-primed follicular development, ovulation and luteinization, adult rats during normal estrous cycle, and aged rats that spontaneously developed persistent estrus (PE). All four rat models were confirmed by histological examination of one ovary, and the other ovary was used for RIA. In postnatal rats, cGMP level was high at birth and decreased dramatically by Day 5, and then, it increased maximally at Day 10 and declined at Day 21. However, cGMP-PDE activity did not significantly change during Days 1 to 10, but increased significantly on Day 21. In immature female rats, cGMP level markedly decreased upon treatment with equine chorionic gonadotropin (eCG), while cGMP-PDE activity did not show any significant changes; however, ovarian cGMP level and cGMP-PDE activity increased after injection of an ovulatory dose of human chorionic gonadotropin (hCG) for induction of ovulation and luteinization. In adult rats during normal estrous cycle, cGMP level was high on proestrus and metestrus days, while cGMP-PDE activity was high on estrus day. In PE rats, ovarian cGMP level was similar to that in adult rats on estrus and diestrus days but lower than that on proestrus and metestrus days; ovarian cGMP-PDE activity was lower than that on estrus days but similar as the other estrous cycle days. In addition, there was a significant negative correlation between ovarian cGMP level and cGMP-PDE activity during normal estrous cycles in the adult rat (r = -0.7715, N = 16, P < 0.05), but not in the postnatal rat (r = -0.1055, N = 20, P > 0.05). Together, the results of our present study indicated that ovarian cGMP levels were not dependent on cGMP-PDE activity during early postnatal development, but highly dependent on cGMP-PDE activity in the adult rat. This implies that mechanisms of cGMP signaling involved in ovarian functions are stage-specific in the rat.
Assuntos
GMP Cíclico/metabolismo , Folículo Ovariano/fisiologia , Ovário/fisiologia , Diester Fosfórico Hidrolases/metabolismo , Animais , Ativação Enzimática , Ciclo Estral , Feminino , Gonadotropinas/farmacologia , Folículo Ovariano/citologia , Folículo Ovariano/efeitos dos fármacos , Ovário/citologia , Ovário/efeitos dos fármacos , RatosRESUMO
Recent animal studies have indicated that overexpression of the elongation of long-chain fatty acids family member 6 (Elovl6) gene can cause insulin resistance and ß-cell dysfunction. These are the major factors involved in the development of type 2 diabetes mellitus (T2DM). To identify the relationship between single nucleotide polymorphisms (SNP) of ELOVL6 and T2DM pathogenesis, we conducted a case-control study of 610 Han Chinese individuals (328 newly diagnosed T2DM and 282 healthy subjects). Insulin resistance and islet first-phase secretion function were evaluated by assessment of insulin resistance in a homeostasis model (HOMA-IR) and an arginine stimulation test. Three SNPs of the ELOVL6 gene were genotyped with polymerase chain reaction-restriction fragment length polymorphism, with DNA sequencing used to confirm the results. Only genotypes TT and CT of the ELOVL6 SNP rs12504538 were detected in the samples. Genotype CC was not observed. The T2DM group had a higher frequency of the C allele and the CT genotype than the control group. Subjects with the CT genotype had higher HOMA-IR values than those with the TT genotype. In addition, no statistical significance was observed between the genotype and allele frequencies of the control and T2DM groups for SNPs rs17041272 and rs6824447. The study indicated that the ELOVL6 gene polymorphism rs12504538 is associated with an increased risk of T2DM, because it causes an increase in insulin resistance.
Assuntos
Acetiltransferases/genética , Diabetes Mellitus Tipo 2/genética , Polimorfismo de Nucleotídeo Único/genética , Adulto , China/etnologia , Diabetes Mellitus Tipo 2/etnologia , Elongases de Ácidos Graxos , Feminino , Genótipo , Humanos , Resistência à Insulina/genética , Células Secretoras de Insulina/patologia , Masculino , Pessoa de Meia-Idade , Polimorfismo de Fragmento de RestriçãoRESUMO
Recent animal studies have indicated that overexpression of the elongation of long-chain fatty acids family member 6 (Elovl6) gene can cause insulin resistance and β-cell dysfunction. These are the major factors involved in the development of type 2 diabetes mellitus (T2DM). To identify the relationship between single nucleotide polymorphisms (SNP) of ELOVL6 and T2DM pathogenesis, we conducted a case-control study of 610 Han Chinese individuals (328 newly diagnosed T2DM and 282 healthy subjects). Insulin resistance and islet first-phase secretion function were evaluated by assessment of insulin resistance in a homeostasis model (HOMA-IR) and an arginine stimulation test. Three SNPs of the ELOVL6 gene were genotyped with polymerase chain reaction-restriction fragment length polymorphism, with DNA sequencing used to confirm the results. Only genotypes TT and CT of the ELOVL6 SNP rs12504538 were detected in the samples. Genotype CC was not observed. The T2DM group had a higher frequency of the C allele and the CT genotype than the control group. Subjects with the CT genotype had higher HOMA-IR values than those with the TT genotype. In addition, no statistical significance was observed between the genotype and allele frequencies of the control and T2DM groups for SNPs rs17041272 and rs6824447. The study indicated that the ELOVL6 gene polymorphism rs12504538 is associated with an increased risk of T2DM, because it causes an increase in insulin resistance.
Assuntos
Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Acetiltransferases/genética , /genética , Polimorfismo de Nucleotídeo Único/genética , China/etnologia , /etnologia , Genótipo , Resistência à Insulina/genética , Células Secretoras de Insulina/patologia , Polimorfismo de Fragmento de RestriçãoRESUMO
We investigated a possible association of collagen IX tryptophan (Trp) alleles (Trp2 and Trp3) and smoking with cervical spondylotic myelopathy (CSM) in 172 Chinese patients and 176 age- and gender-matched controls. The smoking status was evaluated by smoking index (SI). The CSM cases had a significantly higher prevalence of Trp2 alleles (Trp2+) than controls (19.8 vs 6.2%, P = 0.002), but the prevalence of Trp3 alleles (Trp3+) was similar between the two groups (23.3 vs 21.6%, P = 0.713). Logistic regression analyses showed that the subjects with Trp2+ had a higher risk for CSM. We thus analyzed whether smoking status influenced the association between Trp2 alleles and CSM risk. Among Trp2+ subjects with an SI less than 100, the smoking status did not influence the effect of risk for SCM [odds ratio (OR) = 1.34, 95% confidential interval (95%CI) = 0.85-2.18, P > 0.05]. When SI increased from 101 to 300, the OR for CSM reached 3.34 (95%CI = 2.11-5.67, P = 0.011); when SI was more than 300, the OR for CSM reached 5.56 (95%CI = 3.62-7.36, P < 0.001). Among Trp2- subjects with SI more than 300, the OR for CSM increased 2.14 (95%CI = 1.15-4.07, P = 0.024). We found a significant association between the Trp2 alleles and CSM risk and smoking amplifies this risk, suggesting that smoking abstinence is important for reducing CSM occurrence in subjects with high genetic risk.