Caterina Proto

Stromal-epithelial interactions modulate estrogen responsiveness in normal human endometrium

Abstract The coculture of endometrial epithelial cells (EEC) with stromal cells (ESC) allows achievement of an improved in vitro system for studying interactions between cells via soluble signals. The purpose of this study was to investigate whether 17β-estradiol and insulin can induce proliferation of EEC through ESC-secreted factors. No evidence of estrogen-induced EEC proliferation has been reported so far in the conventional culture methods. To this end, we used an in vitro bicameral coculture model where human EEC were grown on extracellular matrix-coated inserts applied in dishes containing ESC. Proliferation was assessed by tritiated thymidine incorporation. Homogeneity of endometrial cell populations was ascertained immunocytochemically. 17β-Estradiol did not induce any proliferative effect on EEC cultured alone. Endometrial epithelial cell proliferation was significantly enhanced in EEC/ESC cocultures; moreover, it was further increased by 17β-estradiol addition. Insulin increased proliferation in EEC cultured alone, but again the effect was more pronounced in EEC/ESC cocultures. Coincubation of 17β-estradiol and an antibody against insulin-like growth factor I (IGF I) led to neutralization of ESC-mediated EEC proliferation. This work provides evidence that the effect of 17β-estradiol on human EEC proliferation may be mediated at least in part through ESC-secreted IGF I. We also showed that insulin effect is also partially due to ESC activation.

Leptin Levels in Menopause: Effect of Estrogen Replacement Therapy

To evaluate the effect of menopause and estrogen replacement therapy on leptin levels, 17 white postmenopausal women were recruited for the study. After an overnight fasting, blood samples were collected for LH, FSH, estradiol, testosterone, androstenedione, DHEA sulfate, insulin and leptin assays. Body mass index (BMI) and the waist-to-hip ratio were also evaluated. Patients were reanalyzed after a 12-week administration of transdermal estrogen patches delivering 50 μg 17β-estradiol. The results were compared to those obtained from a group of 11 female volunteers in reproductive age, in whom basal blood was sampled during the early follicular phase of their cycle. Patients were divided into lean and obese according to their BMI. Obese postmenopausal women showed lower leptin levels when compared to premenopausal counterparts (25.1 ± 5.9 vs. 37 ± 11.3; p < 0.05), whereas no significant differences were found between the lean groups (14.5 ± 3.8 vs. 14.4 ± 4.9). Estrogen administration did not significantly change serum leptin concentrations in hypoestrogenized women (obese: 25.1 ± 5.9 vs. 28.6 ± 9.2; lean: 14.4 ± 4.9 vs. 17.6 ± 7.2). A positive linear correlation was found between leptin plasma levels and BMI only in obese patients (r = 0.58; p < 0.01) both before and after estrogen treatment. Menopause is characterized by a decreased expression of the obese gene, even if estrogens do not seem to represent a main causal factor.

Plasma levels of neuropeptides in Alzheimer's disease

Background. In the central nervous system, several neuropeptides are believed to be involved in the pathophysiology of Alzheimers disease (AD). Indeed, previous studies have documented that glucagon-like peptide 1 (GLP-1) possesses neurotropic properties and can reduce amyloid-β peptide levels in the brain in vivo. Moreover, the concentrations of neuropeptide Y (NPY) seem to be altered in the cerebrospinal fluid of patients with AD and in subjects with major depression. Finally, among the modifications induced by aging, a dysregulation of the ghrelin–growth hormone (GH) system has been reported. Methods. We investigated the plasma concentrations of these neuropeptides in 14 subjects with AD. Data obtained from these patients were compared with data from an age- and weight-matched healthy group. Results. No significant differences were found between the two groups in relation to plasma levels of GLP-1, NPY, ghrelin and GH. Peripheral NPY concentrations were positively correlated with ghrelin levels in both groups, and with plasma GLP-1 concentration only in controls. Conclusion. On the basis of our results, peripheral levels of these neuropeptides seem not to serve as biochemical markers of AD.

Growth hormone and somatomedin-C secretion in patients with polycystic ovarian disease. Their relationships with hyperinsulinism and hyperandrogenism

Nineteen women with polycystic ovarian disease (PCO; 9 obese) and 15 normal ovulatory women (7 obese) were studied at their follicular phase. All patients had an oral glucose tolerance test (OGTT) before and after treatment with gonadotropin-releasing hormone (GnRH) agonist (Buserelin 400 micrograms/die s.c. for 8 weeks) to investigate the relationship between ovarian steroidogenesis and insulin and growth hormone (GH) and insulin-like growth factor (SmC) secretion. Luteinizing hormone, follicle-stimulating, estradiol, androstenedione, testosterone, dehydroepiandrosterone sulfate, cortisol, insulin, GH and SmC were measured basally at the time of OGTT. PCO patients showed higher androgen basal levels than control patients. All subjects showed a normal glycemic response to OGTT. The mean fasting level and area under the curve of plasma insulin were also significantly greater in PCO than in control patients (p less than 0.05), while GH and SmC plasma concentrations did not differ between the groups. Despite a considerable decrease in androgens and the similar levels in both PCO and control women, buserelin treatment did not determine any significant changes of insulin and GH-SmC secretion. GH and SmC did not correlate with ideal body weight (IBW), insulin or androgens, whereas insulin correlated with both testosterone and androstenedione levels (p less than 0.05) and with IBW (p less than 0.01); after the buserelin regimen only IBW remained related to plasma insulin (p less than 0.01). In conclusion results of this study confirm that hyperinsulinism is a characteristic picture of PCO and is related in an unclear way with hyperandrogenism and obesity.(ABSTRACT TRUNCATED AT 250 WORDS)

Alteration of ghrelin-neuropeptide Y network in obese patients with polycystic ovary syndrome: Role of hyperinsulinism

Objective  Insulin, ghrelin, neuropeptide Y (NPY) and leptin interact in the regulation of energy homeostasis. Most of these signals are altered in polycystic ovary syndrome (PCOS), which is characterized by a high prevalence of obesity. The present study was conducted to evaluate ghrelin–NPY and ghrelin–leptin interplays in relation to insulin secretion in obese PCOS subjects.

The Metabolic Status Modulates the Effect of Metformin on the Antimullerian Hormone-Androgens-Insulin Interplay in Obese Women with Polycystic Ovary Syndrome

CONTEXT In the adult ovary, antimullerian hormone (AMH) is produced by the granulosa cells of preantral and small antral follicles and negatively regulates folliculogenesis. AMH is overproduced in the polycystic ovary and was recently proposed to play a role in the ovulatory dysfunction of polycystic ovary syndrome (PCOS). OBJECTIVE The aim of the study was to investigate the effects of metformin administration on AMH levels in relation with the clinical and endocrine-metabolic parameters in obese women with PCOS. DESIGN AND SETTING We conducted a pilot prospective study in an academic research environment. PATIENTS We studied 28 obese PCOS women. INTERVENTIONS We performed ultrasonographic pelvic exams, hirsutism score evaluation, hormonal profile assays, oral glucose tolerance test, euglycemic hyperinsulinemic clamp, and lipid profile at baseline and after 6 months of metformin treatment (850 mg twice a day orally). MAIN OUTCOME MEASURES We measured AMH, hormonal assays, ultrasound aspect of the ovaries, and indexes of glucose and insulin metabolism. RESULTS Insulin secretion and body mass index significantly decreased after treatment. Almost 70% of subjects experienced an amelioration of menstrual irregularities. Mean androstenedione, testosterone, and 17-hydroxyprogesterone levels and hirsutism score were significantly improved by metformin. However, no significant changes in AMH levels occurred. Data were further analyzed after dividing patients on the basis of pretreatment insulinemic response to the oral glucose tolerance test; metformin was effective in reducing insulin secretion, AMH levels, and, interestingly, ovarian volume exclusively in PCOS patients with hyperinsulinism; none of these changes occurred in the normoinsulinemic group. CONCLUSIONS Metformin differentially affects the interplay between insulin and the ovarian function in obese PCOS women; the presence of hyperinsulinemia seems to be predictive of the efficacy of the treatment.

Evidence of a disturbance of the hypothalamic-pituitary-adrenal axis in polycystic ovary syndrome: effect of naloxone.

DESIGN There are conflicting data on hypothalamic‐pituitary‐adrenal (HPA) axis function in women with polycystic ovary syndrome (PCOS). We have evaluated the HPA axis responses to naloxone in patients with PCOS compared to control subjects.

Serum leptin concentrations in obese women with Down syndrome and Prader–Willi syndrome

We have evaluated serum leptin concentrations in two forms of genetic obesity. The subjects examined were eight women with Down syndrome and eight women with Prader-Willi syndrome. All patients were in the reproductive age range and were obese (body mass index > or = 27 kg/m2). Plasma leptin values, analyzed as a function of body mass index showed a statistically significant correlation in both Prader-Willi (r = 0.985; p < 0.001) and Down syndrome patients (r = 0.943; p < 0.001). Obese Down syndrome women exhibited significantly lower leptin values (10.8 +/- 1.1) as compared to patients with Prader-Willi syndrome (31 +/- 2.6; p < 0.01). The linear correlation between leptin and insulin in the two groups of patients was not statistically significant. The data suggested that obesity in Prader-Willi subjects could be caused by failure of leptin to reach its target in the brain, as a consequence of defects in the receptor or in postreceptor processing, whereas data on obese patients with Down syndrome could be due to a different pathogenetic origin.

Basal body temperature curves and endocrine pattern of menstrual cycles in Down syndrome

We examined the basal body temperature curves and the endocrine pattern of 20 cycles from women with Down syndrome with regular menstrual cycles. Data were compared with those obtained from an age-matched population of healthy women with regular menses. Growth hormone deficiency was excluded for women with Down syndrome by pharmacological tests. Women with Down syndrome showed a significantly higher incidence of anovulation and luteal defects than controls (p < 0.001). Overall, and in ovulatory cycles, estradiol and progesterone plasma levels were greater in controls than in women with Down syndrome. No difference was observed for gonadotropin and androgen circulating levels between the two groups. It is concluded that in women with Down syndrome with regular menses, ovulatory events were less frequent and often characterized by luteal defects. This could be ascribed to an impairment of both follicular and luteal functions. However, reproduction is possible in such patients.

Growth hormone administration normalizes the ovarian responsiveness to follicle-stimulating-hormone in the early stages of the follicular maturation in women with Down Syndrome

To investigate the sensitivity of ovary to follicle-stimulating hormone (FSH) during the early follicular phase of the human menstrual cycle in patients with Down Syndrome (DS) six post-menarchal patients with Down Syndrome and twelwe normoovulatory women were studied. Randomly, DS patients were submitted in two consecutive cycles to a treatment with GH (0.1 IU/Kg im) or saline for 3 days. Pure FSH (75 IU) was given iv at day 3 and plasma levels of LH, FSH, E2, Testosterone, DHEAS, Androstenedione, GH and IGF-I were assayed in samples collected for a period of 26h after the injection. Data were compared with those obtained from controls receiving pure FSH or saline. In control patients FSH injection increased E2 stimulated area under curve (AUC). This value was significantly greater than that found in DS patients, who exhibited an E2-stimulated AUC superimposable to saline treated controls. In DS GH plasma concentrations were significantly lower than in control group (p<0.05). The treatment with GH is able to normalize the ovarian response to FSH in DS patients at levels similar to those found in FSH treated controls. Moreover in GH treated cycles, both GH and IGF-I plasma concentrations were higher at time of FSH injection with respect to those found in the cycles where saline was given. These results indicate that the ovarian sensitivity to FSH in patients with DS is blunted. Lower GH plasma levels found in this group may in part account for this biological feature, since GH treatment is able to restore the ovarian response, probably via an increase of IGF-I plasma concentrations.