Yoshimitsu Kitajima

Altered expression of Fas/Fas ligand/caspase 8 and membrane type 1-matrix metalloproteinase in atretic follicles within dehydroepiandrosterone-induced polycystic ovaries in rats

One of the characteristics of polycystic ovary syndrome (PCOS) is the presence of cystic follicles in various stages of growth and atresia, the latter of which is known to be the result of apoptosis and tissue remodeling. To further investigate the process of follicular atresia, we compared ovarian expression and localization of Fas, Fas ligand (FasL), casapse-8 and membrane-type1 matrix metalloproteinase (MT1-MMP) in rats treated with dehydroepiandrosterone (DHEA) as a model of PCOS, and in control rats. We found that the numbers of TdT-mediated dUTP-biotin nick end-labeling (TUNEL)-positive follicles were significantly higher in ovaries from PCOS rats than in those from control rats (P < 0.05), as were ovarian levels of FasL mRNA and protein, processed caspase-8 protein and MT1-MMP mRNA. Correspondingly, we also observed an increase in the level of MTI-MMP catalytic activity and a decrease in the level of pro-caspase-8 protein. In addition, immunohistochemical analyses showed that MT1-MMP and FasL co-localize with TUNEL-positive apoptotic granulosa cells within atretic follicles of PCOS ovaries. Our results suggest that under the PCOS-like conditions induced by DHEA, the Fas/FasL/Caspase-8 (death receptor dependent) pathway is pivotal for follicular atresia, and that increased levels of MT1-MMP likely play an important role in tissue remodeling during structural luteolysis.

Cyclic changes in expression of mRNA of vascular endothelial growth factor, its receptors Flt-1 and KDR/Flk-1, and Ets-1 in human corpora lutea ☆

OBJECTIVE To evaluate the expression of mRNA of vascular endothelial growth factor (VEGF), its receptors Flt-1 and KDR/Flk-1, and Ets-1 in human corpora lutea. DESIGN Prospective laboratory study. SETTING University hospital in Japan. PATIENT(S) Women with regular menstrual cycles who underwent hysterectomy. INTERVENTION(S) Fifteen corpora lutea were obtained during hysterectomy (5 in the early luteal phase, 5 in the mid-luteal phase, and 5 in the late luteal phase). MAIN OUTCOME MEASURE(S) Expression of VEGF, Flt-1, KDR/Flk-1, and Ets-1 in human corpora lutea on northern blot analysis or immunohistochemistry. RESULT(S) Human corpora lutea in early luteal phase and mid-luteal phase had high VEGF mRNA expression. Expression of VEGF mRNA was significantly reduced in the late luteal phase. Immunohistochemistry showed that VEGF protein was expressed mainly in granulosa lutein cells and faintly in thecal lutein cells. Staining of VEGF protein was decreased in human corpora lutea in the late luteal phase. Expression of Flt-1 and KDR/Flk-1 mRNA was increased in the early luteal phase and mid-luteal phase and decreased in the late luteal phase. Immunohistochemistry showed that Flt-1 and KDR/Flk-1 proteins were expressed mainly in granulosa lutein cells and faintly in thecal lutein cells and endothelial cells in the early luteal phase and mid-luteal phase; their protein staining was reduced in the late luteal phase. Expression of Ets-1 mRNA changed similarly to VEGF and its receptor mRNA in human corpora lutea during the luteal phase. CONCLUSION(S) Levels of mRNA of VEGF and its receptors Flt-1 and KDR/Flk-1 in human luteal cells may be related to luteal function.

Expression of vascular endothelial growth factor and E-cadherin in human ovarian cancer: association with ascites fluid accumulation and peritoneal dissemination in mouse ascites model.

Ascites formation and peritoneal dissemination are critical problems in patients with advanced ovarian cancer. Vascular endothelial growth factor (VEGF), also known as angiogenic growth factor, is a potent mediator of peritoneal fluid accumulation and angiogenesis of tumors. E‐Cadherin is an adhesion molecule that is important for cell‐to‐cell interaction. To elucidate the molecular mechanism of ascites formation and peritoneal dissemination of ovarian cancer, we examined the expression of VEGF and E‐cadherin in different ovarian cancer cell lines and utilized nude mice to compare the biological characteristics of ovarian cancer cells. Three human ovarian cancer cell lines (AMOC‐2, HNOA and HTBOA) were used in this study. Expression of genes was analyzed by northern blotting and RT‐PCR methods. AMOC‐2 expressed E‐cadherin, but not VEGF. HNOA expressed VEGF without E‐cadherin expression. HTBOA expressed both VEGF and E‐cadherin. Each human ovarian cancer model revealed a specific feature. The AMOC‐2 mouse had a single large peritoneal tumor without ascites or remarkable peritoneal dissemination. HTBOA and HNOA mice had bloody ascites and marked peritoneal dissemination. Introduction of VEGF antisense into HTBOA cells could inhibit the ascites formation. It is suggested that VEGF is important for the ascites formation via the increased vascular permeability effect. The deregulation of E‐cadherin expression might be involved in the peritoneal dissemination. These molecules are important for the formation of specific features of advanced ovarian cancer. Ovarian cancer cell lines that had different gene expression patterns produced nude mouse human ovarian cancer models with different characteristics.

Remarkable features of ovarian morphology and reproductive hormones in insulin-resistant Zucker fatty (fa/fa) rats

BackgroundZucker fatty (fa/fa) rats are a well-understood model of obesity and hyperinsulinemia. It is now thought that obesity/hyperinsulinemia is an important cause of endocrinological abnormality, but to date there have been no reports on the changes in ovarian morphology or the ovarian androgen profile in rat models of obesity and insulin resistance.MethodsIn this study we investigated the effects of obesity and hyperinsulinemia on ovarian morphology and the hormone profile in insulin-resistant Zucker fatty rats (5, 8, 12 and 16 weeks of age, n = 6-7).ResultsOvaries from 5-week-old fatty rats had significantly greater total and atretic follicle numbers, and higher atretic-to-total follicle ratios than those from lean rats. Ovaries from 12- and 16-week-old fatty rats showed interstitial cell hyperplasia and numerous cysts with features of advanced follicular atresia. In addition, serum testosterone and androstenedione levels significantly declined in fatty rats from age 8 to 16 weeks, so that fatty rats showed significantly lower levels of serum testosterone (12 and 16 weeks) and androstenedione (all weeks) than lean rats. This may reflect a reduction of androgen synthesis during follicular atresia. Serum adiponectin levels were high in immature fatty rats, and although the levels declined significantly as they matured, it remained significantly higher in fatty rats than in lean rats. On the other hand, levels of ovarian adiponectin and its receptors were significantly lower in mature fatty rats than in lean mature rats or immature fatty rats.ConclusionsOur findings indicate that ovarian morphology and hormone profiles are significantly altered by the continuous insulin resistance in Zucker fatty rats. Simultaneously, abrupt reductions in serum and ovarian adiponectin also likely contribute to the infertility seen in fatty rats.

Successful delivery after vaginal radical trachelectomy for invasive uterine cervical cancer.

A 32-year-old Japanese woman was diagnosed as having stage Ib1 adenocarcinoma by diagnostic laser conization at a local hospital. She was admitted to our hospital for fertility-sparing treatment. A radical trachelectomy (RT) was performed using the laparoscopic vaginal procedure. The procedure was started with a laparoscopic pelvic lymphadenectomy. As the lymph nodes were tumor free, RT was carried out transvaginally. The excised uterine cervix and lymph nodes were pathologically negative for cancer. Eight months after the operation, the patient became pregnant without any artificial reproduction techniques. At 17 weeks of gestation, she was admitted to our hospital again for a threatened abortion. Continuous tocolytic treatment with ritodrine and daily administration of a granulocyte elastase inhibitor vaginal suppository were given. At 32 weeks of gestation, she underwent emergency cesarean section because of sudden premature rupture of the membranes. A girl weighing 1991 g was delivered, with Apgar scores of 7 and 8 at 1 and 5 min, respectively. Both the mother and the baby were discharged without trouble. This is the first successful case in Japan of delivery after vaginal RT for invasive uterine cervical cancer.

Spontaneous ovarian hyperstimulation syndrome and pituitary adenoma: incidental pregnancy triggers a catastrophic event

OBJECTIVE To report a rare case of spontaneous ovarian hyperstimulation syndrome (OHSS) associated with spontaneous pregnancy and a FSH-secreting pituitary adenoma. DESIGN Case report. SETTING University hospital. PATIENT(S) A 32-year-old woman with spontaneous OHSS. INTERVENTION(S) Transsphenoidal resection of the tumor. MAIN OUTCOME MEASURE(S) Regression of the symptoms of OHSS and hyperestrogenemia. RESULT(S) At presentation, the patients ovaries were markedly enlarged and massive ascites was seen. Her serum E(2) level was markedly elevated, but her LH level was low, and FSH was within the normal range. In addition, her TSH level was normal, and hCG was appropriate for the date of pregnancy. Subsequently, the patient developed massive thrombophlebitis in her right internal jugular and subclavian veins. Termination of the pregnancy ameliorated the accumulation of ascites, but ovarian enlargement and hyperestrogenemia persisted. No mutations of the FSH receptor, LH receptor, or aromatase genes were detected, but magnetic resonance imaging (MRI) of the head revealed a pituitary adenoma. After transsphenoidal resection of the tumor, the patient got better. CONCLUSION(S) A gonadotropin-secreting adenoma caused ovarian hyperstimulation (ovarian enlargement and hyperestrogenemia). In addition, spontaneous pregnancy and intrinsic hCG increased vascular permeability, which complicated the patients disease.

The contributions of resistin and adiponectin gene single nucleotide polymorphisms to the genetic risk for polycystic ovary syndrome in a Japanese population

Polycystic ovary syndrome (PCOS) is a heterogeneous group of disorders that occur fairly commonly in women of reproductive age and are characterized by a variety of clinical manifestations, including insulin resistance that is independent of obesity. Recent studies suggest that altered adipocytokine gene expression is closely associated with insulin resistance and that single nucleotide polymorphisms (SNPs) modulate the expression and/or function of these genes, thereby affecting insulin sensitivity. With that in mind, we investigated whether SNPs at position −420 of the resistin gene (RETN) and/or −11377 of the adiponectin gene (ADIPOQ) modulate the susceptibility to PCOS. We evaluated the genotypes of 117 women with PCOS and 380 healthy fertile controls and measured the index of insulin resistance and hormonal profiles in the PCOS women. The RETN−420G/G homozygous variant genotype occurred significantly more frequently among the PCOS group than among the control group (15.4% vs. 8.4%, p = 0.035). PCOS women with the RETN−420G/G genotype also showed significantly higher BMIs and greater insulin resistance than those with RETN−420 C/C or C/G genotypes. The ADIPOQ SNP at −11377 showed no association with PCOS. We conclude that the RETN G/G at −420 genotype is associated with PCOS in Japanese women.

The effects of growth hormone on corpus luteum of superovulated rats.

In general, growth hormone acts as a factor promoting cell proliferation in the positive direction and suppresses apoptosis. No report has described growth hormone (GH)-induced structural luteolysis. The present studies showed that GH induced structural luteolysis in rats after the induction of functional luteolysis by treatment with bromocriptine, and that apoptotic cells were present among luteal cells during structural luteolysis as shown by terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling. Zymography showed that the activity of matrix metalloproteinase (MMP)-2 increased during GH-induced structural luteolysis. The expression of c-myc protein of luteal cells was significantly decreased, but proliferating cell nuclear antigens (PCNA) were conversely increased during structural luteolysis, as shown by Western blot analysis. We propose that an excessive increase in PCNA and a marked decrease in c-myc protein of luteal cells lead to a disorder in the signals concerned with DNA synthesis, causing mitotic catastrophe and inducing apoptosis in luteal cells, and that structural luteolysis may be triggered. GH-induced apoptosis in structural luteolysis therefore highly depends on the cell cycle. There are thought to be two mechanisms of GH-induced structural luteolysis. One is apoptosis, and the other is destruction of extracellular matrix by MMP.

Successful twin pregnancy in panhypopituitarism caused by suprasellar germinoma.

BACKGROUND Pregnancy in a woman with hypopituitarism from a suprasellar germinoma is rare. CASE A 27-year-old woman presented with panhypopituitarism from a suprasellar germinoma. She had diabetes insipidus, hypothyroidism, adrenal cortex dysfunction, and hypogonadotropic ovarian failure. When treated with thyroxin, cortisol, antidiuretic hormone, human menopausal gonadotropin, and human chorionic gonadotropin, she conceived and gave birth to healthy twins. CONCLUSION Hormonal replacement therapy and ovulation induction resulted in a successful pregnancy in a woman with panhypopituitarism.

Continuous follicle-stimulating hormone exposure from pituitary adenoma causes periodic follicle recruitment and atresia, which mimics ovarian hyperstimulation syndrome

Context Follicle-stimulating hormone (FSH)-secreting pituitary adenoma is usually a nonfunctioning tumor, but in rare cases it may develop into ovarian hyperstimulation. Several reports have revealed that serum FSH levels are normal to slightly high in patients with combined FSH-secreting pituitary adenoma with ovarian hyperstimulation. This finding is different from iatrogenic ovarian hyperstimulation syndrome (OHSS), which is associated with extremely high levels of FSH. Objective To describe the clinical course of two patients who developed OHSS from FSH-secreting pituitary adenoma. Results Endocrine studies of the two cases revealed that FSH levels were normal or slightly increased, but luteinizing hormone levels were low to undetectable. Their estradiol (E2) levels were intriguing: levels fluctuated drastically over 6 weeks in Case 1, but stayed flat in Case 2. Ultrasonographic examinations showed bilaterally enlarged multicystic ovaries, and magnetic resonance imaging indicated pituitary tumors. Transsephenoidal resection of the tumors ameliorated the symptoms and pathological diagnosis revealed FSH-secreting pituitary adenomas. Conclusion As is not the case in iatrogenic OHSS, even a small to moderate amount of FSH stimulation, which is continuously secreted by a pituitary adenoma, can cause ovarian hyperstimulation. Although FSH-secreting pituitary adenoma can cause ovarian hyperstimulation, an extremely high amount of E2 biosynthesis from granulosa cells seldom occurs.