DooSeok Choi

Characterization of Cyclin D2 Expression in Human Endometrium

Objective: This study was undertaken to investigate cyclin D2 mRNA and protein expression in human endometrium during the menstrual cycle. Methods: Endometrial samples were obtained from 15 premenopausal nonpregnant women who had hysterectomies for benign gynecologic reasons. They were divided into the following five groups according to histologic dating: early proliferative (n = 3), mid to late proliferative (n = 3), early secretory (n = 3), mid secretory (n = 3), and late secretory (n = 3). Cyclin D2 mRNA and protein expression were analyzed using reverse transcriptase-polymerase chain reaction, Western blotting, and immunohistochemistry. Results: Cyclin D2 mRNA and protein were expressed in human endometrial tissue throughout the menstrual cycle. Cyclin D2 mRNA and protein expression of proliferative phase endometrium were significantly higher than those of secretory phase endometrium (P < .05). The staining intensity of cyclin D2 in proliferative phase endometrium was higher than that in secretory phase (P < .05). Cyclin D2 mRNA level showed good correlation with cyclin D2 protein level (R = 0.579, P < .03), and cyclin D2 protein also showed good correlation with immunohistochemical staining intensity (R = 0.562, P < .03). Conclusion: Cyclin D2 was expressed in human endometrium throughout the menstrual cycle. Cyclin D2 mRNA and protein were expressed at high levels in proliferative phase endometrium, especially in the early proliferative phase, and then decreased in the secretory phase.

Expression of Mitochondria-Dependent Apoptosis Genes (p53, Bax, and Bcl-2) in Rat Granulosa Cells During Follicular Development

Objective: We examined rat ovarian granulosa cells at different follicular stages and evaluated the apoptosis pattern of the mitochondria-dependent genes during folliculogenesis. Methods: After down-regulating ovarian function with gonadotropin-releasing hormone agonist (Gn-RHa), granulosa cells were collected from the rat ovary at different stages of the following different hormonal treatment paradigms: stage E (after estrogen treatment), EF (after E + follicle-stimulating hormone [FSH] treatment), and EF hCG (after E + FSH + human chorionic gonadotropin treatment). To evaluate the in vitro susceptibility of granulosa cells at different developmental stages to apoptosis, the collected cells were cultured in a serum-free medium with or without E2 for 24 hours. The regulation of apoptosis in the granulosa cells was analyzed using fluorescein-activated cell sorting, quantitative competitive polymerase chain reaction, and western blot methods. Results: The apoptosis rate of the freshly isolated granulosa cells tended to increase according to the hormonal treatment paradigm. In addition, during the hormone treatment, mitochondria-dependent apoptosis genes showed the following changes: although the Bax mRNA level did not change, the Bcl-2 mRNA level decreased significantly (P < .05). The p53 mRNA level increased significantly (P < .05) and closely matched the apoptosis rate (R = 0.7, P < .05). The expression of the active form of the caspase-3 protein (the final executioner of cell death) tended to increase and showed a good correlation with the apoptosis rate (R = 0.96, P < .01). After an in vitro culture of the granulosa cells, the apoptosis rate tended to increase at all stages, particularly stage EF hCG (P < .05). Bax and p53 mRNA tended to increase and showed a good correlation with the apoptosis rate (R = 0.64, P < .05 and 0.86, P < .01). The Bcl-2 mRNA level tended to decrease at all stages showing no correlation with the apoptosis rate. The expression level of the active caspase-3 protein tended to increase at all stages and showed a good correlation with the apoptosis rate (R = 0.93, P < .01). Conclusion: Apoptosis of rat ovarian granulosa cells tends to increase according to the stage of follicular development. Among the mitochondria-dependent genes, p53 closely correrlates with granulosa cell apoptosis during follicular development.

In vivo hormonal regulation of insulin-like growth factor binding protein-5 mRNA in the immature rat ovary.

Objective: Despite the potential importance of insulin-like growth factor binding protein-5 (IGFBP-5) to follicular development, the hormonal regulation of this antigonadotropic IGFBP has not been investigated. Therefore, it was the objective of this study to eludicate the role of gonadotropins and estrogen in the in vivo regulation of IGFBP-5 mRNA expression. Methods: Two models of follicular development in immature rats were used. Specifically, rats were hypophysectomized and treated with FSH and/or diethylstilbestrol (DES). Alternatively, terminal follicular development was induced in intact immature rats by pregnant mare serum gonadotropin (PMSG) and hCG. The IGFBP-5 mRNA in whole ovarian RNA was assayed by Northern blot hybridization. Localization of expression in PMSG and hCG-stimulated ovaries was further assessed by in situ hybridization. Results: Expression of IGFBP-5 mRNA was increased in ovaries from hypophysectomized rats. Treatment with FSH and/or DES did not alter the abundance of this mRNA. Treatment with PMSG induced a transient increase in IGFBP-5 expression that was localized in a subset of α-inhibin-negative follicles. At later times after PMSG, IGFBP-5 expression persisted in the surface epithelium but was not detected in large preovulatory follicles. In vitro studies affirmed the antigonadotropic action of IGFBP-5. Conclusion: In vivo expression of IGFBP-5 in the rat ovary is moderated by hormonal treatment both in terms of total expression and follicular localization.

Characterization and Hormonal Regulation of Granulosa Cell-Derived Insulin-Like Growth Factor Binding Protein-4

Objective: Because of the potential importance of insulin-like growth factor binding protein-4 (IGFBP-4) to ovarian physiology and the obvious limitations imposed by in vivo-exclusive experimental paradigms, we set out to delineate the characteristics and hormonal regulation of granulosa cell-derived IGFBP-4 under in vitro circumstances. Methods: Granulosa cells obtained by follicular puncture of the ovaries from diethylstilbestrol-primed intact immature rats were subjected to culture for up to 72 hours. Insulin-like growth factor binding protein-4 mRNA extracted from culture was subjected to Northern blot hybridization. Data normalization was assured by reprobing with the hamster Chinese hamster ovary B (CHOB) cDNA, and the IGFBP-4/CHOB ratio was calculated. Conditioned culture media were subjected to Western ligand blot before and after immunoprecipitation with a rat IGFBP-4-directed polyclonal antiserum (αB104). Results: Immunoprecipitation studies revealed granulosa cell-derived IGFBP-4 to be composed of a major 24-kDa species as well as a relatively minor 27-kDa moiety. Given cultures of untreated granulosa cells from immature estrogen-treated rats, transcripts corresponding to IGFBP-4 displayed an initial temporary decline culminating in a 6-hour nadir (a decrease of 67%; P < .05) followed by relatively prompt recovery (within 24 hours) to levels comparable to those noted at the outset of the culture (time 0). However, additional (albeit statistically insignificant) increments were noted at the 48-hour (but not 72-hour) time point. Treatment of granulosa cells with increasing concentration of FSH resulted in decrements of up to 30% (P < .05) in the steady-state levels of IGFBP-4 transcripts. A modest, biphasic, time-dependent response was noted for IGFBP-4 transcripts after treatment with high-dose FSH (100 ng/mL), an effect characterized by 24-and 48-hour increments (51% [P < .05] and 26% [P = .052] over untreated controls, respectively) and a 72-hour decrement (25%; P = .16). The concurrent provision of the C19 aromatase substrate androstenedione (10-7 mol/L) to the culture medium from 72 hours enhanced the inhibitor effect of FSH (100 ng/mL) for a maximal decrement in IGFBP-4 transcripts of 49% (P < .05). Treatment with insulin-like growth factor (IGF)-I produced limited inhibition (up to 26%) of the steady-state levels of IGFBP-4 transcripts (P < .05). Conclusion: Findings indicate the existence of heterogenously-sized IGFBP-4 species, of which the 27-kDa (as distinct from the 27-kDa) IGFBP-4 moiety constitutes a relatively minor component. The steady-state levels of granulosa cell-derived IGFBP-4 transcripts display relatively limited regulation in response to treatment with either FSH or IGF-I.

Associations of Health-Risk Behaviors and Health Cognition With Sexual Orientation Among Adolescents in School: Analysis of Pooled Data From Korean Nationwide Survey From 2008 to 2012.

AbstractHomosexual adolescents may face significant health disparities. We examined health-risk behaviors and health cognition related to homosexual behavior in a representative sample of adolescents.Data were obtained from 129,900 adolescents between 2008 and 2012 over 5 cycles of the Korean Youth Risk Behavior Survey, a national survey of students in grades 7 to 12. Various health-risk behaviors and aspects of health cognition were compared between homosexual and heterosexual adolescents and analyzed with multiple logistic regression models.Compared with heterosexual adolescents (n = 127,594), homosexual adolescents (n = 2306) were more likely to engage in various health-risk behaviors and to have poor health cognition. In multiple logistic regression analysis, not living with parents, alcohol experience (adjusted odds ratio, 1.50; 95% confidence interval, 1.26–1.78 for males and 1.66; 1.33–2.07 for females), smoking experience (1.80; 1.54–2.10 for males and 3.15; 2.61–3.79 for females), and drug experience (3.65; 2.81–4.80 for males and 3.23; 2.35–4.46 for females) were associated with homosexual behavior. Homosexual adolescents were more likely to use adult internet content (2.82; 2.27–3.50 for males and 7.42; 4.19–13.15 for females), and to be depressed (1.21; 1.03–1.43 for males and 1.32; 1.06–1.64 for females). In addition, suicide ideation (1.51; 1.26–1.81 for males and 1.47; 1.16–1.86 for females) and attempts (1.67; 1.37–2.05 for males and 1.65; 1.34–2.03 for females) were significantly more prevalent among homosexual adolescents.Homosexual adolescents report disparities in various aspects of health-risk behavior and health cognition, including use of multiple substances, adult internet content and inappropriate weight loss methods, suicide ideation and attempts, and depressive mood. These factors should be addressed relevantly to develop specific interventions regarding sexual minorities.

Effects of adding alendronate to ongoing hormone therapy on bone mineral density in postmenopausal Korean women: a randomized, double-blind, placebo-controlled clinical trial.

ObjectiveThis study was conducted to evaluate the effects of adding the bisphosphonate alendronate (ALEN) to ongoing hormone therapy (HT) on bone mineral density (BMD) in postmenopausal Korean women. MethodsThis randomized, double-blind, placebo-controlled clinical trial at a university hospital included a total of 139 postmenopausal women who had low BMD after HT lasting at least 1 year. Women received either ALEN (10 mg/d) or placebo in combination with HT for 1 year. Changes in BMD and biochemical markers of bone turnover were evaluated. ResultsLumbar spine and total hip BMDs increased significantly in both treatment groups after 1 year. The addition of ALEN, when compared with HT alone, did not produce a significant change in BMD at the lumbar spine (3.7% vs 4.3%) and total hip (2.2% vs 3.2%) after adjusting for controllable variables. Serum osteocalcin showed a similar change, but urinary deoxypyridinoline response differed between treatment groups. ConclusionsCompared with HT alone, the addition of ALEN to ongoing HT for 1 year does not make a difference in BMD among postmenopausal Korean women with low BMD.

CORRECTION: The Role of Autophagy in Corpus Luteum Regression in the Rat

In the Materials and Methods, within Animal Treatment, an error was found in the following sentence: Rats were killed by cervical dislocation, and the ovaries were excised at 1, 7, 14, and 20 days after hCG administration. The sentence should have read ‘‘. . . excised at 2, 7, 14, and . . .’’ In the Results, within Apoptotic Cell Death of Luteal Cells Increased with the Accumulation of Autophagosomes, errors were found in the following sentences: As shown in Figure 5, A and B, the serum starvation-induced expression of BAX decreased significantly upon 3-MA treatment, but increased significantly following treatment with Baf A1 (P , 0.05; Fig. 5B, top). In contrast, the serum starvation-induced expression of BCL2 increased significantly in 3-MA-treated luteal cells, but decreased significantly with Baf A1 treatment (P , 0.05; Fig. 5B, middle). The sentences should have read ‘‘. . . expression of BAX did not change with 3-MA treatment . . . luteal cells, but did not change with Baf A1 treatment . . .’’ The authors regret these errors.