Sheila Bünecker Lecke

Adipose tissue dysfunction, adipokines, and low-grade chronic inflammation in polycystic ovary syndrome

Polycystic ovary syndrome (PCOS), a complex condition that affects women of reproductive age, is characterized by ovulatory dysfunction and androgen excess. Women with PCOS present higher prevalence of obesity, central adiposity, and dyslipidemia, and face increased risk of type 2 diabetes. PCOS is closely linked to functional derangements in adipose tissue. Adipocytes seem to be prone to hypertrophy when exposed to androgen excess, as experienced by women with PCOS, and both adipose tissue hypertrophy and hyperandrogenism are related to insulin resistance. Hypertrophic adipocytes are more susceptible to inflammation, apoptosis, fibrosis, and release of free fatty acids. Disturbed secretion of adipokines may also impact the pathophysiology of PCOS through their influence on metabolism and on sex steroid secretion. Chronic low-grade inflammation in PCOS is also related to hyperandrogenism and to the hypertrophy of adipocytes, causing compression phenomena in the stromal vessels, leading to adipose tissue hypoperfusion and altered secretion of cytokines. Lifestyle changes are the first-line intervention for reducing metabolic risks in PCOS and the addition of an insulin-sensitizing drug might be required. Nevertheless, there is not sufficient evidence in favor of any specific pharmacologic therapies to directly oppose inflammation. Further studies are warranted to identify an adipokine that could serve as an indirect marker of adipocyte production in PCOS, representing a reliable sign of metabolic alteration in this syndrome.

Abdominal subcutaneous fat gene expression and circulating levels of leptin and adiponectin in polycystic ovary syndrome

OBJECTIVE To determine leptin and adiponectin serum levels and gene expression in subcutaneous adipose tissue from women with polycystic ovary syndrome (PCOS) and nonhirsute, ovulatory women; and leptin/adiponectin (L/A) ratio. DESIGN Case-control study. SETTING University hospital gynecologic endocrinology unit. PATIENT(S) Thirty-one women with PCOS and 57 controls. INTERVENTION(S) Anthropometric, hormonal, and metabolic assessment; subcutaneous adipose tissue biopsy. MAIN OUTCOME MEASURE(S) Leptin and adiponectin serum levels, L/A ratio, controlled by age, and gene expression in women with PCOS and controls, stratified by body mass index and variables associated with androgen excess and insulin resistance. RESULT(S) Serum leptin was higher in overweight/obese patients with PCOS than in all normal-weight control women. Adiponectin levels were similar in all subgroups. The L/A ratio was lower in normal-weight controls (1.80; range 0.94-3.72) than in overweight/obese controls (5.27; range 2.66-13.58) and patients with PCOS (7.73; range 3.81-15.04). Subcutaneous leptin messenger RNA was higher in overweight/obese women with PCOS than in normal-weight controls (2.316 [range 1.987-2.580] vs. 1.687 [range 1.518-2.212]). Adiponectin gene expression was similar in all groups. Positive correlations were found between serum and messenger RNA levels for both leptin and adiponectin. On multiple regression analysis, percentage of body fat contributed significantly to L/A ratio in PCOS, independently of body mass index and free androgen index. CONCLUSION(S) In PCOS, altered adipocyte secretion seems to relate to adiposity rather than to androgen excess.

Leptin and adiponectin in the female life course

Dilated cardiomyopathy can be the end-stage form and common denominator of several cardiac disorders of known cause, such as hypertensive, ischemic, diabetic and Chagasic diseases. However, some individuals have clinical findings, such as an increase in ventricular chamber size and impaired contractility (classical manifestations of dilated cardiomyopathy) even in the absence of a diagnosed primary disease. In these patients, dilated cardiomyopathy is classified as idiopathic since its etiology is obscure. Nevertheless, regardless of all of the advances in medical, pharmacological and surgical procedures, the fate of patients with dilated cardiomyopathy (of idiopathic or of any other known cause) is linked to arrhythmic episodes, severe congestive heart failure and an increased risk of sudden cardiac death. In this review, we will summarize present data on the use of cell therapies in animal models of dilated cardiomyopathies and will discuss the few clinical trials that have been published so far involving patients affected by this disease. The animal models discussed here include those in which the cardiomyopathy is produced by genetic manipulation and those in which disease is induced by chemical or infectious agents. The specific model used clearly creates restrictions to translation of the proposed cell therapy to clinical practice, insofar as most of the clinical trials performed to date with cell therapy have used autologous cells. Thus, translation of genetic models of dilated cardiomyopathy may have to wait until the use of allogeneic cells becomes more widespread in clinical trials of cell therapies for cardiac diseases.Adipose tissue secretes a variety of adipokines, including leptin and adiponectin, which are involved in endocrine processes regulating glucose and fatty metabolism, energy expenditure, inflammatory response, immunity, cardiovascular function, and reproduction. The present article describes the fluctuations in circulating leptin and adiponectin as well as their patterns of secretion in women from birth to menopause. During pregnancy, leptin and adiponectin seem to act in an autocrine/paracrine fashion in the placenta and adipose tissue, playing a role in the maternal-fetal interface and contributing to glucose metabolism and fetal development. In newborns, adiponectin levels are two to three times higher than in adults. Full-term newborns have significantly higher leptin and adiponectin levels than preterms, whereas small-for-gestational-age infants have lower levels of these adipokines than adequate-for-gestational-age newborns. However, with weight gain, leptin concentrations increase significantly. Children between 5 and 8 years of age experience an increase in leptin and a decrease in adiponectin regardless of body mass index, with a reversal of the newborn pattern for adiponectin: plasma adiponectin levels at age five are inversely correlated with percentage of body fat. In puberty, leptin plays a role in the regulation of menstrual cycles. In adults, it has been suggested that obese individuals exhibit both leptin resistance and decreased serum adiponectin levels. In conclusion, a progressive increase in adiposity throughout life seems to influence the relationship between leptin and adiponectin in women.

Association between adipose tissue expression and serum levels of leptin and adiponectin in women with polycystic ovary syndrome

We reviewed emerging evidence linking serum levels and adipose tissue expression of leptin and adiponectin in women with polycystic ovary syndrome (PCOS). Previous data obtained by our group from a sample of overweight/obese PCOS women and a control sample of normal weight controls, both stratified by BMI, were reanalyzed. Circulating levels of leptin and adiponectin were determined by commercially available enzyme-linked immunosorbent assays. Adipose tissue total RNA was reserve-transcripted into complementary DNA samples, which were used as templates for quantitative real-time PCR amplification. Positive correlations were found between serum and mRNA levels for both leptin (r = 0.321; P = 0.005) and adiponectin (r = 0.266; P = 0.024). Determination of leptin and adiponectin serum levels could serve as an indirect method to assess adipocyte production, since leptin and adiponectin are predominantly produced by subcutaneous adipocytes in women.

Gene Expression of Leptin and Long Leptin Receptor Isoform in Endometriosis: A Case-Control Study

In this study, leptin/BMI ratio in serum and peritoneal fluid and gene expression of leptin and long form leptin receptor (OB-RL) were assessed in eutopic and ectopic endometria of women with endometriosis and controls. Increased serum leptin/BMI ratio was found in endometriosis patients. Leptin and OB-RL gene expression was significantly higher in ectopic versus eutopic endometrium of patients and controls. A positive, significant correlation was observed between leptin and OB-RL transcripts in ectopic endometria and also in eutopic endometria in endometriosis and control groups. A negative and significant correlation was found between OB-RL mRNA expression and peritoneal fluid leptin/BMI ratio only in endometriosis. These data suggest that, through a modulatory interaction with its active receptor, leptin might play a role in the development of endometrial implants.

Circulating and peritoneal fluid interleukin‑6 levels and gene expression in pelvic endometriosis

Current data are inconsistent regarding the association between interleukin-6 (IL-6), a marker of acute phase inflammation, and pelvic endometriosis. The aim of the present study was to assess IL-6 levels in serum and peritoneal fluid (PF), as well as IL-6 gene expression in adipose tissue (AT) and endometrial samples in pelvic endometriosis. A total of 30 patients with endometriosis and 18 women with a normal pelvis were enrolled in this case-control study. IL-6 levels in PF and serum were determined using a human enzyme-linked immunosorbent assay and IL-6 gene expression was evaluated using reverse transcription-quantitative polymerase chain reaction. It was observed that IL-6 levels in the PF were higher in patients with endometriosis than in the control group (P=0.047) and patients with stage III/IV endometriosis exhibited higher IL-6 levels in the PF than those with stage I/II endometriosis and the control group (P<0.001). Furthermore, a strong correlation between PF IL-6 levels and the revised American Society for Reproductive Medicine score for endometriosis severity was identified (r=0.77; P<0.001). IL-6 gene expression did not differ significantly between endometriosis and control groups in endometrial samples or in AT of both groups. The results of the current study suggest that there may be an association between IL-6 and the presence and severity of pelvic endometriosis. The source of this higher IL-6 seems not to be specifically related to regional AT.

Microtubule cytoskeleton distribution using fluorescent taxoid in tetratrichomonas didelphidis

ABSTRACT Tetratrichomonas didelphidis is a flagellated protozoan found in the intestine of opossums. Thespecimens were stained by the Giemsa method and by FLUTAX-2, an active fluorescent derivative ofTaxol which binds to the αβ -tubulin polimerized of microtubules of cells. Giemsa stain revealed themorphological features of trichomonads such as four anterior flagella, undulating membrane, axostyleand posterior flagellum. An intense fluorescence was observed in living trophozoites of T. didelphidis and Trichomonas vaginalis (used as control), incubated with FLUTAX-2. An analysis of thecomposition of the cytoskeleton of T. didelphidis will contribute to understanding the cellularmorphology of the parasites. Key words: Tetratrichomonas didelphidis , microtubule cytoskeleton, fluorescent taxoid. INTRODUCTIONFew trichomonad species have a provenpathogenic potential for mammals and birds. Ingeneral, the species inhabiting trichomonadprimary sites, i. e., the large intestine, appear tobe non pathogenic. The species with provenpathogenic potential have evolved to inhabit areasother than the large intestine of their hosts