Leptin regulation of reproductive function and fertility

Changes in Body Reserves, Non-Esterified Fatty Acids, and Leptin during the Reproductive Lifespan of the Rabbit Female

The aim of this work is to study changes in body weight, perirenal fat thickness (PFT), and non-esterified fatty acid (NEFA) and leptin concentrations throughout the reproductive life of the rabbit female and their correlations when a semi-intensive reproductive rhythm is applied. A total of 46 lactating females were used. Body weight, PFT, and NEFA and leptin concentration were recorded at 12 weeks of age, at first mating and delivery, and at second, third, and fourth mating, 12th d of gestation, and delivery. The highest body weight was detected on the 12th d of any gestation, around 4280 g, and the lowest weight was at delivery, around 4030 g. PFT increased until third mating. NEFA and leptin concentration showed a cyclical pattern throughout the reproductive lifespan of the females. NEFAs presented the highest concentration at delivery within each reproductive cycle and levels decreased over the course of the deliveries (0.423 mmol/L at first delivery, 0.406 mmol/L at second delivery, 0.371 mmol/L at third delivery, and 0.309 mmol/L at fourth delivery). Similar NEFA concentrations at mating and on the 12th d of gestation were obtained. Leptin showed the highest concentrations at mating within each reproductive cycle. Leptin decreased between mating and delivery in all reproductive cycles and it was close to 1 ng/mL HE. Low or null correlations were shown between body weight, PFT, and NEFA and leptin concentration at mating, 12th d of gestation, and delivery. In conclusion, females are able to maintain a semi-intensive reproductive rhythm across four parities weighing around 4 kg from first mating. Females had an increased perirenal fat thickness until third delivery, and their NEFA concentration was maximum at delivery and leptin concentration was maximum at mating. Body weight, PFT, and NEFA and leptin concentration should be measured during critical moments of reproductive life in order to determine body condition and energy mobilization, due to their low or null correlations.

Cold and Hungry: Heterothermy Is Associated with Low Leptin Levels in a Bulk Grazer during a Drought

AbstractReduced energy intake can compromise the ability of a mammal to maintain body temperature within a narrow 24-h range, leading to heterothermy. To investigate the main drivers of heterothermy in a bulk grazer, we compared abdominal temperature, body mass, body condition index, and serum leptin levels in 11 subadult Cape buffalo (Syncerus caffer caffer) during a drought year and a nondrought year. Low food availability during the drought year (as indexed by grass biomass, satellite imagery of vegetation greenness, and fecal chlorophyll) resulted in lower body condition index, lower body mass relative to that expected for an equivalent-aged buffalo, and lower leptin levels. The range of 24-h body temperature rhythm was 2°C during the nondrought year and more than double that during the drought year, and this was caused primarily by a lower minimum 24-h body temperature rhythm during the cool dry winter months. After rain fell and vegetation greenness increased, the minimum 24-h body temperature rhythm increased, and the range of 24-h body temperature rhythm was smaller than 2°C. In order of importance, poor body condition, low minimum 24-h air temperature, and low serum leptin levels were the best predictors of the increase in the range of 24-h body temperature rhythm. While the thermoregulatory role of leptin is not fully understood, the association between range of 24-h body temperature rhythm and serum leptin levels provides clues about the underlying mechanism behind the increased heterothermy in large mammals facing food restriction.

Turning the tide on sex and the microbiota in aquatic animals

Sex-based differences in animal microbiota are increasingly recognized as of biological importance. While most animal biomass is found in aquatic ecosystems and many water-dwelling species are of high economic and ecological value, biological sex is rarely included as an explanatory variable in studies of the aquatic animal microbiota. In this opinion piece, we argue for greater consideration of host sex in studying the microbiota of aquatic animals, emphasizing the many advancements that this information could provide in the life sciences, from the evolution of sex to aquaculture.

MOET Efficiency in a Spanish Herd of Japanese Black Heifers and Analysis of Environmental and Metabolic Determinants

Multiple ovulation and embryo transfer (MOET) systems have been intensively implemented in Japanese Black cattle in Japan and to create Japanese Black herds out of these areas. Environmental conditions influence MOET efficiency. Thus, we describe results of 137 in vivo, non-surgical embryo flushings performed between 2016-2020, in a full-blood Japanese Black herd kept in Spain and the possible effects of heat, year, bull, donor genetic value, and metabolic condition. Additionally, 687 embryo transfers were studied for conception rate (CR) and recipient related factors. A total of 71.3% of viable embryos (724/1015) were obtained (5.3 ± 4.34/flushing). Donor metabolites did not affect embryo production (p > 0.1), although metabolite differences were observed over the years, and by flushing order, probably related to the donor age. CR was not affected by embryo type (fresh vs. frozen), recipient breed, and whether suckling or not suckling (p > 0.1). CR decreased significantly with heat (44.3 vs. 49.2%; (p = 0.042)) and numerically increased with recipient parity and ET-number. Pregnant recipients showed significantly higher levels of cholesterol-related metabolites, glucose, and urea (p < 0.05). Therefore, adequate MOET efficiency can be achieved under these conditions, and heat stress should be strongly avoided during Japanese Black embryo transfers. Moreover, recipients' metabolites are important to achieve pregnancy, being probably related to better nutrient availability during pregnancy.

Leptin and PCSK9 concentrations are associated with vascular endothelial cytokines in patients with stable coronary heart disease

Leptin and proprotein convertase subtilisin kexin 9 (PCSK9) play an important role in regulating blood lipid concentration. Recently, they have been found to show the ability to independently regulate the immune response. Vascular immune response has an important pathological function in the development of coronary heart disease (CHD) and thrombosis. The aim of this study was to explore the relationship between leptin, PCSK9, and vascular endothelial cell related inflammatory factors. First, detailed clinical information were collected and analyzed for 27 patients with stable CHD and corresponding 27 healthy controls. Second, using liquid-phase protein chip technology, leptin, PCSK9, and vascular-related inflammatory factors, such as E-selectin, vascular cell adhesion protein 1 (VCAM-1), intercellular cell adhesion molecule-1 (ICAM-1), interferon-gamma (IFN-γ), and interleukin-17 (IL-17), were detected on the same platform. Finally, the correlation between leptin, PCSK9, and the inflammatory factors was analyzed. Through collecting clinical information of patients, it was suggested that there was a significant positive correlation between leptin and blood lipid level in CHD. Compared with healthy people, the levels of leptin, PCSK9, E-selectin, and ICAM-1 were significantly high in patients with CHD. There was a high positive correlation between leptin and E-selectin, ICAM-1, IFN-γ, and IL-17. Also, a high positive correlation between PCSK9 and E-selectin, IFN-γ, and IL-17 concentrations was observed. In general, leptin and PCSK9 may not only be able to regulate lipid metabolism, but may also be able to regulate inflammation in CHD.

Pharmacological and non-pharmacological strategies for obese women with subfertility

BACKGROUND

Clinicians primarily recommend weight loss for obese women seeking pregnancy. The effectiveness of interventions aimed at weight loss in obese women with subfertility is unclear.

OBJECTIVES

To assess the effectiveness and safety of pharmacological and non-pharmacological strategies compared with each other, placebo, or no treatment for achieving weight loss in obese women with subfertility.

SEARCH METHODS

We searched the CGF Specialised Register, CENTRAL, MEDLINE, Embase, PsycINFO, and AMED from inception to 18 August 2020. We also checked reference lists and contacted experts in the field for additional relevant papers.

SELECTION CRITERIA

We included published and unpublished randomised controlled trials in which weight loss was the main goal of the intervention. Our primary effectiveness outcomes were live birth or ongoing pregnancy and primary safety outcomes were miscarriage and adverse events. Secondary outcomes included clinical pregnancy, weight change, quality of life, and mental health outcome.

DATA COLLECTION AND ANALYSIS

Review authors followed standard Cochrane methodology.

MAIN RESULTS

This review includes 10 trials. Evidence was of very low to low quality: the main limitations were due to lack of studies and poor reporting of study methods. The main reasons for downgrading evidence were lack of details by which to judge risk of bias (randomisation and allocation concealment), lack of blinding, and imprecision. Non-pharmacological intervention versus no intervention or placebo Evidence is insufficient to determine whether a diet or lifestyle intervention compared to no intervention affects live birth (odds ratio (OR) 0.85, 95% confidence interval (CI) 0.65 to 1.11; 918 women, 3 studies; I² = 78%; low-quality evidence). This suggests that if the chance of live birth following no intervention is assumed to be 43%, the chance following diet or lifestyle changes would be 33% to 46%. We are uncertain if lifestyle change compared with no intervention affects miscarriage rate (OR 1.54, 95% CI 0.99 to 2.39; 917 women, 3 studies; I² = 0%; very low-quality evidence). Evidence is insufficient to determine whether lifestyle change compared with no intervention affects clinical pregnancy (OR 1.06, 95% CI 0.81 to 1.40; 917 women, 3 studies; I² = 73%; low-quality evidence). Lifestyle intervention resulted in a decrease in body mass index (BMI), but data were not pooled due to heterogeneity in effect (mean difference (MD) -3.70, 95% CI -4.10 to -3.30; 305 women, 1 study; low-quality evidence; and MD -1.80, 95% CI -2.67 to -0.93; 43 women, 1 study; very low-quality evidence). Non-pharmacological versus non-pharmacological intervention We are uncertain whether intensive weight loss interventions compared to standard care nutrition counselling affects live birth (OR 11.00, 95% CI 0.43 to 284; 11 women, 1 study; very low-quality evidence), clinical pregnancy (OR 11.00, 95% CI 0.43 to 284; 11 women, 1 study; very low-quality evidence), BMI (MD -3.00, 95% CI -5.37 to -0.63; 11 women, 1 study; very low-quality evidence), weight change (MD -9.00, 95% CI -15.50 to -2.50; 11 women, 1 study; very low-quality evidence), quality of life (MD 0.06, 95% CI -0.03 to 0.15; 11 women, 1 study; very low-quality evidence), or mental health (MD -7.00, 95% CI -13.92 to -0.08; 11 women, 1 study; very low-quality evidence). No study reported on adverse events . Pharmacological versus pharmacological intervention For metformin plus liraglutide compared to metformin we are uncertain of an effect on the adverse events nausea (OR 7.22, 95% CI 0.72 to 72.7; 28 women, 1 study; very low-quality evidence), diarrhoea (OR 0.31, 95% CI 0.01 to 8.3; 28 women, 1 study; very low-quality evidence), and headache (OR 5.80, 95% CI 0.25 to 133; 28 women, 1 study; very low-quality evidence). We are uncertain if a combination of metformin plus liraglutide vs metformin affects BMI (MD 2.1, 95% CI -0.42 to 2.62; 28 women, 1 study; very low-quality evidence) and total body fat (MD -0.50, 95% CI -4.65 to 3.65; 28 women, 1 study; very low-quality evidence). For metformin, clomiphene, and L-carnitine versus metformin, clomiphene, and placebo, we are uncertain of an effect on miscarriage (OR 3.58, 95% CI 0.73 to 17.55; 274 women, 1 study; very low-quality evidence), clinical pregnancy (OR 5.56, 95% CI 2.57 to 12.02; 274 women, 1 study; very low-quality evidence) or BMI (MD -0.3, 95% CI 1.17 to 0.57, 274 women, 1 study, very low-quality evidence). We are uncertain if dexfenfluramine versus placebo affects weight loss in kilograms (MD -0.10, 95% CI -2.77 to 2.57; 21 women, 1 study; very low-quality evidence). No study reported on live birth, quality of life, or mental health outcomes. Pharmacological intervention versus no intervention or placebo We are uncertain if metformin compared with placebo affects live birth (OR 1.57, 95% CI 0.44 to 5.57; 65 women, 1 study; very low-quality evidence). This suggests that if the chance of live birth following placebo is assumed to be 15%, the chance following metformin would be 7% to 50%. We are uncertain if metformin compared with placebo affects gastrointestinal adverse events (OR 0.91, 95% CI 0.32 to 2.57; 65 women, 1 study; very low-quality evidence) or miscarriage (OR 0.50, 95% CI 0.04 to 5.80; 65 women, 1 study; very low-quality evidence) or clinical pregnancy (OR 2.67, 95% CI 0.90 to 7.93; 96 women, 2 studies; I² = 48%; very low-quality evidence). We are also uncertain if diet combined with metformin versus diet and placebo affects BMI (MD -0.30, 95% CI -2.16 to 1.56; 143 women, 1 study; very low-quality evidence) or waist-to-hip ratio (WHR) (MD 2.00, 95% CI -2.21 to 6.21; 143 women, 1 study; very low-quality evidence). Pharmacological versus non-pharmacological intervention No study undertook this comparison.

AUTHORS' CONCLUSIONS

Evidence is insufficient to support the use of pharmacological and non-pharmacological strategies for obese women with subfertility. No data are available for the comparison of pharmacological versus non-pharmacological strategies. We are uncertain whether pharmacological or non-pharmacological strategies effect live birth, ongoing pregnancy, adverse events, clinical pregnancy, quality of life, or mental heath outcomes. However, for obese women with subfertility, a lifestyle intervention may reduce BMI. Future studies should compare a combination of pharmacological and lifestyle interventions for obese women with subfertility.

Relationship between Prenatal Characteristics and Body Condition and Endocrine Profile in Rabbits

Simple Summary

Litter size is an essential trait in rabbit production, and it depends on ovulation rate and embryonic and foetal survival. The period between 8 and 18 d of gestation is critical for foetal survival, as the placenta controls foetal nutrition during this period. Ovulation rate and foetal survival at 12 d of gestation are affected by body condition and metabolic and hormonal profile. Higher foetal survival is related to a higher number of vessels arriving at the implantation site, and may be due to higher available space for the foetus.

Abstract

This study evaluated the relationship between prenatal characteristics and body condition and endocrine profile. A total of 25 non-lactating multiparous females were used. Body condition, measured as body weight and perirenal fat thickness, non-esterified fatty acids (NEFA), leptin, progesterone and 17β-estradiol were recorded at mating and 12 d of gestation. Ovulation rate, number of foetuses, ovary and foetal weight, length and weight of uterine horn, available space per foetus and maternal and foetal placental morphometry were recorded at 12 d of gestation. Ovulation rate showed a positive linear relationship with number of foetuses, ovary weight and NEFA. A negative linear relationship between ovulation rate and perirenal fat thickness and leptin was obtained. Ovulation rate was maximum when body weight and 17β-estradiol were 4.4 kg and 22.7 pg/mL, respectively. Foetal weight showed a positive relationship with perirenal fat thickness and a negative relationship with leptin. An increase in progesterone and NEFA concentration was related to a positive linear increase in number of foetuses and in uterine horn weight. Space available per foetus was affected both by the number of vessels that reach the implantation site and by position of the foetus in the uterine horn. In conclusion, body condition during mating and early gestation should be maintained within an optimal range to ensure the best prenatal characteristics. While 17β-estradiol, NEFA and leptin affected the ovulation rate, progesterone and NEFA affected foetal development. The number of vessels that reach the implantation site determines early foetal survival.

Estradiol and the feeding state modulate the interaction between leptin and the nitrergic system in female rats

Leptin mediates the interaction between reproductive function and energy balance. However, leptin receptors are not expressed in neurons that produce gonadotropin-releasing hormone (GnRH), likely indicating an indirect action through interneurons. Among likely neurons that modulate the secretion of GnRH are NO (nitric oxide) neurons. We assessed whether estradiol and feeding conditions modulate a possible interaction between leptin and NO in brain areas related to the control of reproductive function. Estradiol-treated and untreated ovariectomized rats were normally fed or fasted for 48 h. Then, saline (control) or leptin (3 μg/1 μl) intracerebroventricular microinjections were administered, and after thirty minutes, the brains collected subsequent to the decapitation or transcardially perfusion. Leptin and estradiol increased NO synthase (nNOS) gene expression (RT-PCR) and content (Western blotting) in the medial preoptic area (MPOA) and medial basal hypothalamus (MBH) only in fasted rats. Leptin increased: 1-phosphorylated-signal transducer and activator of transcription-3(pSTAT3) (immunohistochemistry) in the MPOA and various hypothalamic nuclei [arcuate (ARC); ventromedial (VMH); dorsal/ventral dorsomedial (dDMH/vDMH); premammilar ventral (PMV)], effects potentiated by estradiol/fasting interaction; 2- nNOS/pSTAT3 coexpression in the MPOA only in estradiol-treated, fasted rats; 3- nNOS-immunoreactive cell expression in the VMH, DMH and PMV (areas related to reproductive function control) of estradiol -treated rats. Thus, when leptin is reduced during fasting, leptin replacement effectively increased the expression of nitric oxide, which activated the HPG axis only in the presence of estradiol. Estradiol modulates the nitrergic system, leptin sensitivity and consequently leptin's effects on the nitrergic system in hypothalamus and in particular vDMH and PMV.

Sex Differences in Intestinal Carbohydrate Metabolism Promote Food Intake and Sperm Maturation

Physiology and metabolism are often sexually dimorphic, but the underlying mechanisms remain incompletely understood. Here, we use the intestine of Drosophila melanogaster to investigate how gut-derived signals contribute to sex differences in whole-body physiology. We find that carbohydrate handling is male-biased in a specific portion of the intestine. In contrast to known sexual dimorphisms in invertebrates, the sex differences in intestinal carbohydrate metabolism are extrinsically controlled by the adjacent male gonad, which activates JAK-STAT signaling in enterocytes within this intestinal portion. Sex reversal experiments establish roles for this male-biased intestinal metabolic state in controlling food intake and sperm production through gut-derived citrate. Our work uncovers a male gonad-gut axis coupling diet and sperm production, revealing that metabolic communication across organs is physiologically important. The instructive role of citrate in inter-organ communication might be significant in more biological contexts than previously recognized.

•

Intestinal carbohydrate metabolism is male-biased and region-specific

•

Testes masculinize gut sugar handling by promoting enterocyte JAK-STAT signaling

•

The male intestine secretes citrate to the adjacent testes

•

Gut-derived citrate promotes food intake and sperm maturation

Metabolic biomarkers, body condition, uterine inflammation and response to superovulation in lactating Holstein cows

The objective was to determine associations between response to superovulation and body condition, subclinical endometritis and circulating metabolic biomarkers [adiponectin, leptin, insulin, IGF1, tumor necrosis factor (TNF) α, interleukin (IL) 1β, IL6, and urea] in lactating dairy cows. Ten multiparous lactating Holstein cows in each body condition score (1-5; 1 emaciated; 5 obese) category (BCSC) 2.00 to < 2.50 (BCSC1), 2.50 to < 3.00 (BCSC2), 3.00 to <3.50 (BCSC3), 3.50 to <4.00 (BCSC4) and 4.00 to 5.00 (BCSC5) groups (total n = 50) were randomly selected and superovulated, timed artificially inseminated with frozen-thawed semen from three sires and embryos collected (n = 50 collections). At embryo collection, blood samples and embryo recovery fluid were collected for determination of metabolic markers and presence of subclinical endometritis (lavage technique; > 6% PMN). In total, 379 embryos were collected (average of 7.6 embryos per superovulation). Mean numbers of total ova and embryos was greater for cows in BCSC2, BCSC3 and BCSC4 groups compared with cows in BCSC1 and BCSC5 groups (P < 0.01). Total number of transferrable embryos were greater for cows in BCSC 2 and BCSC3 groups compared with cows in BCSC1, BCSC4 and BCSC5 groups (P < 0.01). Mean number of total ova and embryos and of transferrable embryos was higher for cows with 0 or 1-6% PMN compared to cows with >6% PMN (P < 0.01). In addition, there was a quadratic association between blood urea nitrogen concentrations and % transferrable embryos (r² = 0.85; P < 0.05) and between BCS and % transferrable embryos (r² = 0.73; P < 0.05). Circulating adiponectin, leptin, insulin, IGF1 and TNFα were greater in cows with moderate to good body condition compared to thin or obese cows (P < 0.05). Circulating adiponectin, leptin, IGF1 and insulin were greater in normal cows (≤6% PMNs), whereas, TNFα and IL1β and IL6 were greater in cows with subclinical endometritis (P < 0.05). In conclusion, BCS and subclinical endometrial inflammation were associated with superovulatory response and embryo quality. Further, circulating metabolic biomarkers were associated with superovulatory response and embryo quality, likely due to donor's metabolic status and uterine environment. Optimizing superovulatory responses and embryo quality in lactating dairy cows requires management of nutrition and uterine health.

Relationship of Serum Leptin and Reproductive Hormones in Unexplained Infertile and Fertile Females

OBJECTIVE

To investigate the relationship between serum leptin and reproductive hormones in females with unexplained infertility (UI).

METHODOLOGY

It was a case-control study conducted in the Gynecology and Obstetrics Department and Infertility Clinic, Jinnah Postgraduate Medical Center (JPMC), Karachi, Pakistan. A total of 235 primary infertile females with an unidentified cause of infertility were selected from the Infertility Clinics. The patients were excluded if they were found to have polycystic ovary syndrome, endometriosis, tubal blockage, irregular menstrual cycles, hyperthyroidism, hypothyroidism, hyperprolactinemia, hyperandrogenemia, fasting blood sugar >110 mg/dl, and male factor infertility. A total of 205 healthy, fertile females were selected from the general population. The blood samples of both groups were collected on the 12th and 21st day of their menstrual cycle. Serum leptin, follicle-stimulating hormone (FSH), luteinizing hormone (LH), and E2 levels were measured. Statistical analysis was executed using the SPSS version 16 (SPSS Inc., Chicago, IL).

RESULTS

No significant difference was observed in leptin values of fertile and UI females, 37.110±1.19 vs. 35.321±0.901. In the preovulatory phase (12th day) of the cycle, infertile subjects with body mass index (BMI) <20 and 20-24.9 had significantly higher values for leptin (p<0.05), whereas, with an increase in BMI, leptin levels were reduced in these females. Leptin was reduced further in the luteal phase of infertile females with BMI 25-30, with a significantly lower value for FSH (p<0.005), LH (p<0.005), and estradiol (p<0.005. In infertile subjects, it correlated with estradiol (r=0.501, p<0.005), BMI (r=0.903, p<0.001), and progesterone (r=0.146, p<0.05).

CONCLUSION

Low levels of leptin observed to have an increase in the BMI of UI females were associated with a reduced estradiol and progesterone production in the luteal phase of the cycle.

Pre-pubertal growth, muscle and fat accumulation in male and female sheep-Relationships with metabolic hormone concentrations, timing of puberty and reproductive outcomes

Metabolic homeostasis is aligned with changes in growth and body composition, through processes mediated by circulating metabolites and metabolic hormones, and is eventually linked to reproductive success. In the present study with sheep, we determined the relationships among phenotypic and genotypic rates of growth, muscle and fat accumulation, and the circulating concentrations of metabolic and tested for relationships with the timing of puberty and subsequent reproductive outcomes. We used 64 females and 62 males with known phenotypic values for depth of eye muscle (EMD) and fat (FAT) and known Australian Sheep Breeding Values at post-weaning age for live weight (PWT), depth of eye muscle (PEMD) and depth of fat (PFAT). Blood plasma sampled every 20 min for 8 hr via was assayed for growth hormone (GH), insulin-like growth factor I (IGF-I), insulin, leptin, ghrelin, follistatin, glucose and non-esterified fatty acids (NEFA). In males, PWT was positively related to the concentrations of GH, follistatin and glucose, whereas FAT and PFAT were positively related to IGF-I concentrations (p < .01). Testosterone concentration was negatively related to muscle variables (p < .001) and to PFAT (p < .05). In females, the only significant relationship detected was the positive link between EMD and insulin concentrations (p < .05). Reproductive variables were only measured in females. Live weight at first oestrus was related positively to insulin concentration and negatively to GH concentration (p < .05). No other relationships with reproductive variables were significant. The relationships that were detected suggest subtle differences between the sexes in the way their metabolic homeostasis responds to changes in the rates of growth, and muscle and fat accumulation, perhaps due to interference by testosterone in the males.

No specific adverse pregnancy outcome in singleton pregnancies after assisted reproductive technology (ART) for unexplained infertility

OBJECTIVE

To evaluate the obstetrical outcome of pregnancies obtained after assisted reproductive technology (ART).in women with unexplained infertility.

MATERIALS AND METHODS

We conducted a retrospective observational case - control cohort study between January 2011 and May 2017. All pregnancies obtained after ART (Intra uterine insemination, In Vitro Fertilization, Intra Cytoplasmic Sperm Injection) were included. The ART pregnancy outcome of women with unexplained infertility was compared to ART pregnancies obtained in a context of male infertility. Cases were matched to controls (1:2) for age, Body Mass Index (BMI), and smoking status.

RESULTS

After exclusion of twins, we studied 67 singleton pregnancies in the case group, matched with 129 singleton pregnancies in the control group. The first-trimester complications (miscarriage before 12 weeks gestation (WG), ectopic pregnancy) were similar in the two groups. Concerning the 2nd and the 3rd trimester, the incidence of gestational diabetes mellitus, pre-eclampsia, placenta previa, preterm labor was comparable between the two groups. In singletons, we found a non-significant increase of post-partum hemorrhage (OR=5.5, IC 0.5-50, p=0.13) and small for gestational age new-borns (OR=3.45, IC 0.65-18.1, p=0.14) in women with unexplained infertility.

CONCLUSION

More adverse obstetrical outcome are commonly reported after ART, even in singleton pregnancies. Little is known for explaining it and to distingue the own contributions of ART techniques and of the infertility etiology. In our study, we didn't observe a significant negative impact of a history of unexplained infertility on pregnancy. However, further large studies are needed to evaluate more accurately the possible liabilities of the infertility etiology on obstetrical and perinatal outcome.

Early Life Stress Delays Sexual Maturation in Female Mice

In humans, some forms of early life stress (ELS) have been linked with precocious puberty, altered brain maturation, and increased risk for a variety of forms of pathology. Interestingly, not all forms of ELS have been found to equally impact these metrics of maturation. In recent work, we have found that ELS in the form of limited bedding (LB) from P4 to P11, was associated with precocious hippocampus maturation in males and increased risk for depressive-like pathology and attentional disturbance in female mice. Here, we sought to test whether ELS in the form of LB also impacted the timing of sexual maturation in female mice. To establish rate of somatic and sexual development, distinct cohorts of mice were tested for weight gain, timing of vaginal opening, and development of estrous cycling. ELS animals weighed significantly less than controls at every timepoint measured. Onset of vaginal opening was tracked from P21 to 40, and ELS was found to significantly delay the onset of vaginal opening. To test the impact of ELS on estrous cycle duration and regularity, vaginal cytology was assessed in independent groups of animals using either a continuous sampling (daily from P40 to P57) or random sampling approach (single swab at P35, P50, or P75). ELS did impact measures of estrous cycling, but these effects were dependent upon the sampling method used. We also tested the impact of ELS on anxiety-like behaviors over development and across the estrous cycle. We observed a developmental increase in anxiety-like behavior in control but not ELS mice. No effect of estrous cycle stage was found on anxiety-like behavior for either group of mice. Together these results provide evidence that ELS in the form of LB delays somatic and sexual development. Additional work will be required to determine the mechanism by which ELS impacts these measures, and if these effects are common to other models of ELS in rodents.

Candidate SNP markers of reproductive potential are predicted by a significant change in the affinity of TATA-binding protein for human gene promoters

BACKGROUND

The progress of medicine, science, technology, education, and culture improves, year by year, quality of life and life expectancy of the populace. The modern human has a chance to further improve the quality and duration of his/her life and the lives of his/her loved ones by bringing their lifestyle in line with their sequenced individual genomes. With this in mind, one of genome-based developments at the junction of personalized medicine and bioinformatics will be considered in this work, where we used two Web services: (i) SNP_TATA_Comparator to search for alleles with a single nucleotide polymorphism (SNP) that alters the affinity of TATA-binding protein (TBP) for the TATA boxes of human gene promoters and (ii) PubMed to look for retrospective clinical reviews on changes in physiological indicators of reproductive potential in carriers of these alleles.

RESULTS

A total of 126 SNP markers of female reproductive potential, capable of altering the affinity of TBP for gene promoters, were found using the two above-mentioned Web services. For example, 10 candidate SNP markers of thrombosis (e.g., rs563763767) can cause overproduction of coagulation inducers. In pregnant women, Hughes syndrome provokes thrombosis with a fatal outcome although this syndrome can be diagnosed and eliminated even at the earliest stages of its development. Thus, in women carrying any of the above SNPs, preventive treatment of this syndrome before a planned pregnancy can reduce the risk of death. Similarly, seven SNP markers predicted here (e.g., rs774688955) can elevate the risk of myocardial infarction. In line with Bowles' lifespan theory, women carrying any of these SNPs may modify their lifestyle to improve their longevity if they can take under advisement that risks of myocardial infarction increase with age of the mother, total number of pregnancies, in multiple pregnancies, pregnancies under the age of 20, hypertension, preeclampsia, menstrual cycle irregularity, and in women smokers.

CONCLUSIONS

According to Bowles' lifespan theory-which links reproductive potential, quality of life, and life expectancy-the above information was compiled for those who would like to reduce risks of diseases corresponding to alleles in own sequenced genomes. Candidate SNP markers can focus the clinical analysis of unannotated SNPs, after which they may become useful for people who would like to bring their lifestyle in line with their sequenced individual genomes.

A new perspective on managing the onset of puberty and early reproductive performance in ewe lambs: a review

Global changes in industry and society have led us to reassess the numerous factors that combine to influence the time of onset of puberty and the efficiency of reproduction in young sheep. Age and weight have long been considered the dominant factors that influence the onset of puberty and, for many years, it has been accepted that these relationships are mediated by the hormone, leptin, produced by body fat. However, recent studies showing that muscle mass also plays a role have challenged this dogma and also presented new options for our understanding of metabolic inputs into the brain control of reproduction. Moreover, the possibility that an improvement in meat production will simultaneously advance puberty is exciting from an industry perspective. An industry goal of strong reproductive performance in the first year of life is becoming possible and, with it, a major step upwards in the lifetime reproductive performance of ewes. The concept of early puberty is not well accepted by producers for a variety of reasons, but the new data show clear industry benefits, so the next challenge is to change that perception and encourage producers to manage young ewes so they produce their first lamb at 1 year of age.

Gonadal dysfunction in adult male patients with thalassemia major: an update for clinicians caring for thalassemia

INTRODUCTION

Hypogonadism is the most frequently reported endocrine complication, affecting 40%-80% of thalassemia major (TM) patients. The prevalence and severity of hypogonadism in TM varies among studies, depending on patients' age, genotype, transfusion frequency and starting age and efficiency of iron chelation. Areas covered: The diagnosis requires careful clinical assessment and appropriate laboratory testing. Its management is more complex compared to other 'classical' causes of hypogonadism because of multiple associated disorders (cardiac, hepatic and endocrine) and other contributing factors basically iron overload and iron toxicity. Expert commentary: Early recognition and treatment of hypogonadism in TM patients is most important to prevent late complications and to enhance the chances of parenthood. The goal of management is to restore deficient glandular function. If fertility is the issue and the testis is under-stimulated because of gonadotropin deficiency, it is possible to induce or restore spermatogenesis with exogenous gonadotropins in some patients. Assisted reproductive techniques may supplementary help to overcome previously untreatable causes of male infertility. These positive achievements should encourage health care providers to pay closer attention to the reproductive health of TM patients. This would involve the collaboration of clinicians caring for thalassemia with endocrinologists and specialists in assisted reproductive technologies.

Leptin as a Predictive Marker in Unexplained Infertility in North Indian Population

INTRODUCTION

According to WHO, the primary infertility in India is about 3.9% (age-standardized to 25-49 year) and 16.8% (age-standardized to 15-49 year), using the "age but no birth" definition. Several factors which affect fertility include low sperm production in men, poor egg quality and blocked fallopian tubes in women and also hormonal imbalances. Leptin plays a critical role in women's reproduction and neuroendocrine health. It is used for treating exercise-induced bone loss, eating disorders and infertility.

AIM

To evaluate the serum leptin levels in Indians and to ascertain the relationship between serum leptin levels, Unexplained Infertility (UI) and related variables [height, weight, Waist Hip Ratio (WHR), Body Mass Index (BMI)] between obese infertile, non-obese infertile and healthy subjects.

MATERIALS AND METHODS

The present case-control study was conducted at the Department of Obstetrics and Gynaecology, King George's Medical University (KGMU), Lucknow, India and funded by Department of Science and Technology, New Delhi, India. The study included 229 female participants in the age group of 18-40 years (120 cases and 109 controls) who were randomly selected. The blood samples were collected from the Infertility Clinic, Queen Mary's Hospital, KGMU, Lucknow, India. All the participants underwent complete physical examination. Initially, the participants were categorized into fertile and infertile groups, they were further divided on the basis of BMI, normal (BMI- 18.5-24.5) and overweight or obese (BMI≥25). Leptin level was measured by Active Human Leptin ELISA kit and BMI of all subjects was calculated in kg/m² (weight in kg and height in m).

RESULTS

A highly positive linear correlation (R=0.754, p<0.001) was found between BMI and serum leptin in unexplained infertile women, which indicates a strong relationship between BMI and serum leptin. The variation in serum leptin is explained by the independent variable, BMI. There was a partial positive linear correlation between BMI and serum leptin in the control group. Statistically there was no significant correlation (R=0.109, p=0.258) between BMI and serum leptin in the control group.

CONCLUSION

The present study clearly demonstrates that level of leptin is higher in unexplained infertile than in the fertile group, and also shows that a strong relationship exists between BMI and serum leptin in the obese group. Serum leptin level was significantly higher in obese than non-obese subjects. Thus, leptin is an important factor for normal reproductive function. Obesity, the main cause of infertility may be controlled by regulating the leptin concentration.

Relationships between leptin, KiSS-1/GPR54 expression and TSH secretion from pituitary cells of pubertal ewes in vitro

Kisspeptin and leptin play a crucial role in the puberty of sheep as they initiate the activity of hypothalamic-pituitary-ovarian axis. Also hormones of thyrotropic axis are probably involved in this process. The aim of study was to analyze the impact of leptin on kisspeptin-10 secretion as well as kisspeptin-1 and G protein-coupled receptor (GPR54) mRNA expression in pituitary cells of pubertal ewes in vitro. The influence of kisspeptin on TSH secretion was also examined. Cells were cultured in McCoy's 5A medium without hormones; with 10(-10)-10(-5)M of leptin; with 10(-11)-10(-5)M of kisspeptin-10; with peptide 234 (10(-7)M, antagonist of GPR54) or 10(-11)-10(-5)M of kisspeptin-10 and peptide 234. Then, kisspeptin-10 and TSH secretion as well as KiSS-1 and GPR54 expression were analyzed. We found that leptin directly affected kisspeptin-10 secretion and kisspeptin-1/GPR54 expression in pituitary cells of pubertal ewes. Kisspeptin-10 did not change TSH secretion, except exerting a short-term influence after 2h.

A Comparative Study of Serum and Follicular Fluid Leptin Concentrations among Explained Infertile, Unexplained Infertile and Fertile Women

Background

The relationship between metabolism and reproduction has been always considered as an important topic in female endocrinology. It seems that leptin is one of the involved factors in infertility. Leptin, in addition to regulating body weight plays an important role in regulation of endocrine, reproductive and immune systems. The aim of this stduy is to compare serum and follicular fluid leptin concentrations in order to find the role of leptin level in infertility.

Materials and Methods

This case-control study was performed from September 2010 to March 2013. A total of 90 women referred to the Infertility Center of Afzalipour Hos- pital, Kerman, Iran, and divided into three equal groups (n=30/per group) of explained infertile (including 4 subgroups), unexplained infertile and normal fertile (control group). The three groups were matched in regard to demographic features [age: 20-40 years and body mass index (BMI): 20-25]. In order to determine leptin level, blood sample and fol- licular fluid were taken one hour prior and at the time of follicular puncture, respectively. Serum and follicular fluid leptin levels were measured using enzyme-linked immune sorbent assay (ELISA). Data were analyzed using descriptive-analytic tests, like Mann- Whitney and Kruskal Wallis tests, through Statistical Package for the Social Sciences (SPSS) version 16.

Results

In explained infertile and fertile groups, as opposed to unexplained infertile group, mean leptin level was lower in follicular fluid than in serum. Mean follicular fluid leptin concentration in women with unexplained infertility was higher com- pared to the other two groups. Women with unexplained infertility had lower level of serum leptin in comparison to the other two groups. Follicular fluid leptin level in all subgroups of explained infertile group was lower as compared to unexplained and fertile women.

Conclusion

The results suggested that high leptin level of follicular fluid is one of the main factors involved in infertility.

Relationships among body composition, circulating concentrations of leptin and follistatin, and the onset of puberty and fertility in young female sheep

The onset of puberty depends on the attainment of critical body mass, so should also be affected by increases in the rate of accumulation of muscle and adipose tissue. Adipose tissue and reproduction are linked by leptin. For muscle, a link has not yet been identified, although one possibility is follistatin. We assessed the relationships among circulating concentrations of follistatin and leptin and the rates of growth and accumulation of muscle and fat during pubertal development in female sheep. We used 326 animals with known phenotypic values for live weight (LW), depths of eye muscle (EMD) and fat (FAT), and known breeding values at post-weaning age for body mass (PWT) and depths of eye muscle (PEMD) and fat (PFAT). Leptin concentration was positively correlated with values for EMD, PEMD, FAT, PFAT, LW and PWT (P<0.001), whereas follistatin concentration was negatively correlated with values for EMD and PWT (P<0.001), and PEMD (P<0.01) and FAT (P<0.05). Leptin concentration was negatively related to age and positively related to live weight at first oestrus and the proportion of females that attained puberty (P≤0.05), and to fertility and reproductive rate (P<0.01). Follistatin concentration was negatively related to live weight at first oestrus and to fertility (P<0.01) and reproductive rate (P<0.05). There were positive correlations (P<0.001) between muscle accumulation and leptin concentration, and between muscle accumulation and reproductive performance. We conclude that leptin and follistatin are probably both involved in effects of accelerated accumulation of muscle and adipose tissues on the onset of puberty.

Central pathways integrating metabolism and reproduction in teleosts

Energy balance plays an important role in the control of reproduction. However, the cellular and molecular mechanisms connecting the two systems are not well understood especially in teleosts. The hypothalamus plays a crucial role in the regulation of both energy balance and reproduction, and contains a number of neuropeptides, including gonadotropin-releasing hormone (GnRH), orexin, neuropeptide-Y, ghrelin, pituitary adenylate cyclase-activating polypeptide, α-melanocyte stimulating hormone, melanin-concentrating hormone, cholecystokinin, 26RFamide, nesfatin, kisspeptin, and gonadotropin-inhibitory hormone. These neuropeptides are involved in the control of energy balance and reproduction either directly or indirectly. On the other hand, synthesis and release of these hypothalamic neuropeptides are regulated by metabolic signals from the gut and the adipose tissue. Furthermore, neurons producing these neuropeptides interact with each other, providing neuronal basis of the link between energy balance and reproduction. This review summarizes the advances made in our understanding of the physiological roles of the hypothalamic neuropeptides in energy balance and reproduction in teleosts, and discusses how they interact with GnRH, kisspeptin, and pituitary gonadotropins to control reproduction in teleosts.

Undernutrition affects embryo quality of superovulated ewes

To determine the effect of undernutrition on embryo production and quality in superovulated sheep, 45 ewes were allocated into two groups to be fed diets that provided 1.5 (control, C; n = 20) or 0.5 (low nutrition, L; n = 25) times daily requirements for maintenance, from oestrous synchronization with intravaginal sponges to embryo collection. Embryos were collected 7 days after the onset of oestrus (day 0). Low nutrition resulted in lower live weight and body condition at embryo collection (P < 0.05). Diet (P < 0.01) and day of sampling (P < 0.001) significantly affected plasma non-esterified fatty acid (NEFA) and insulin concentrations. Plasma leptin concentrations decreased on day 7 only in L ewes. A significant effect of dietary treatment (P < 0.05) and day (P < 0.0001) was observed on plasma insulin-like growth factor (IGF)-I concentrations. The number of recovered oocytes and embryos did not differ between the groups (L: 15.4 ± 0.4; C: 12.4 ± 0.4). Recovery rate was lower (P < 0.05) in the L (60%) than in the C group (73%). The total number of embryos and number of viable-transferable embryos (5.0 ± 0.3 and 3.4 ± 0.3 embryos, respectively) of the L group were lower (P < 0.1) when compared with controls (8.4 ± 0.4 and 6.2 ± 0.4 embryos, respectively). Undernutrition during the period of superovulation and early embryonic development reduced total and viable number of embryos. These effects might be mediated by disruption of endocrine homeostasis, oviduct environment and/or oocyte quality.

Expression and tissue localization of renalase, a novel soluble FAD-dependent protein, in reproductive/steroidogenic systems

Renalase was initially identified in human kidney as a soluble monoamine oxidase. Here we show that renalase is predominantly expressed in reproductive/steroidogenic systems, with particularly substantial expression in oocytes, granulosa, interstitial and luteal cells of ovary, spermatogenic cells of testis, and cortex of adrenal gland, suggesting its function(s) in maturation of germ cells and steroid hormone regulation. Renalase expression increases in testes and ovaries as mice develop and its expression is further enhanced in the ovaries of pregnant mice, indicating an activity of renalase in reproduction. Gonadotropin-releasing hormone (GnRH) antagonist, cetrorelix, repressed renalase expression in mice ovaries and testes, suggesting that steroids regulate renalase expression. Leptin is an effector and modulator of steroid hormones and reproduction. Surprisingly, knockout of leptin causes a dramatic increase of renalase expression in mice testes. Taken together, our results suggest that reproductive/steroidogenic systems are also the sources for renalase secretion and renalase may play a critical role in reproduction and hormone regulation. This provides a novel insight into understanding the function of renalase.

Glutamate-induced obesity leads to decreased sperm reserves and acceleration of transit time in the epididymis of adult male rats

BACKGROUND

Given the established fact that obesity interferes with male reproductive functions, the present study aimed to evaluate sperm production in the testis and storage in the epididymis in a glutamate-induced model of obesity.

METHODS

Male rats were treated neonatally with monosodium glutamate (MSG) at doses of 4 mg/kg subcutaneously, or with saline solution (control group), on postnatal days 2, 4, 6, 8 and 10. On day 120, obesity was confirmed by the Lee index in all MSG-treated rats. After this, all animals from the two experimental groups were anesthetized and killed to evaluate body and reproductive organ weights, sperm parameters, plasma hormone levels (FSH, LH and testosterone), testicular and epididymal histo-morphometry and histopathology.

RESULTS

Significant reductions in absolute and relative weights of testis, epididymis, prostate and seminal vesicle were noted in MSG-treated animals. In these same animals plasma testosterone and follicle-stimulating hormone (FSH) concentrations were decreased, as well as sperm counts in the testis and epididymis and seminiferous epithelium height and tubular diameter. The sperm transit time was accelerated in obese rats. However, the number of Sertoli cells per seminiferous tubule and stereological findings on the epididymis were not markedly changed by obesity.

CONCLUSIONS

Neonatal MSG-administered model of obesity lowers sperm production and leads to a reduction in sperm storage in the epididymis of adult male rats. The acceleration of sperm transit time can have implications for the sperm quality of these rats.

Heat shock proteins in porcine ovary: synthesis, accumulation and regulation by stress and hormones

The present studies aimed to understand the interrelationships between stress, hormones and heat shock proteins (HSPs) in the ovary. We examined (1) whether HSP70.2, HSP72 and HSP105/110 can be produced and accumulated in porcine ovarian tissue, (2) whether these HSPs could be indicators of stress, i.e. whether two kinds of stress (high temperatures and malnutrition/serum deprivation) can affect them, and (3) whether some hormonal regulators of ovarian functions (insulin-like growth factor (IGF)-I, leptin and follicle-stimulating hormone (FSH)) can affect these HSPs and response of ovaries to HSP-related stress. We analysed the expression of HSP70.2, HSP72 and HSP105/110 mRNA (by using real-time reverse transcriptase polymerase chain reaction) in porcine ovarian granulosa cells, as well as the accumulation of HSP70 protein (by using sodium dodecyl sulphate polyacrylamide gel electrophoresis-Western) in either whole ovarian follicles and granulose cells cultured at normal (37.5°C) or high (41.5°C) temperature, with and without serum and with and without IGF-I, leptin and FSH. Expression of mRNA for HSP70.2, HSP72 and HSP105/110 in ovarian granulosa cells and accumulation of HSP70 protein in whole ovarian follicles and granulosa cells were demonstrated. In all the groups, addition of either IGF-I, leptin and FSH reduced the expression of HSP70.2, HSP72 and HSP105/110 mRNA. Both high temperature, serum deprivation and their combination resulted in increase in mRNAs for all three analysed HSPs. Additions of either IGF-I, leptin and FSH prevented the stimulatory effect of both high temperature and serum deprivation on the transcription of HSP70.2, HSP72 and HSP105/110. In contrast, high temperature reduced accumulation of peptide HSP70 in both ovarian follicles and granulosa cell. Serum deprivation promoted accumulation of HSP70 in granulosa cells, but not in ovarian follicles. Addition of IGF-I, leptin and FSH was able to alter accumulation of HSP70 in both follicles and granulosa cells. The present observations suggest (1) that HSPs can be synthesised in ovarian follicular granulosa cells; (2) that hormones (IGF-I, leptin and FSH) can inhibit, whilst stressors (both high temperature and malnutrition/serum deprivation) can stimulate transcription of HSP70.2, HSP72 and HSP105/110 genes, whilst heat stress, but not malnutrition, can promote depletion of HSP70 in ovarian cells, and (3) that hormones (IGF-I, leptin and FSH) can prevent stress-related changes in HSPs. The application of HSPs as indicators and mediators of stress and hormones on ovarian functions, as well as use of hormones and HSPs as anti-stressor molecules, are discussed.

Predictors of menstrual resumption by patients with anorexia nervosa

OBJECTIVE

To investigate which factors predict the resumption of menstruation by patients with anorexia nervosa (AN).

METHODS

Participants were AN patients who, even after weight recovery by inpatient treatment, had prolonged amenorrhea (N=11), AN patients who resumed menstruation after weight recovery (N=9), and age-matched healthy controls (N=12). Anthropometric data and the serum levels of leptin, insulin-like growth factor I (IGF-1), cortisol, luteinizing hormone (LH), estradiol (E2), and other hormones were measured at the beginning of the inpatient treatment and after weight recovery.

RESULTS

Of the baseline anthropometric and hormonal factors, logistic regression analysis extracted a high serum cortisol level as a predictor of the inhibition of the resumption of menstruation. After weight recovery, the E2 and leptin levels were significantly higher for eumenorrheic patients than for amenorrheic patients.

CONCLUSION

The baseline serum cortisol level was a predictor of the prolonged inhibition of menstrual recovery.

Effect of two types of stress (heat shock/high temperature and malnutrition/serum deprivation) on porcine ovarian cell functions and their response to hormones

The aim of the present study was to understand the interrelationships between stress, hormones and basic ovarian functions in the ovary. For this purpose, we compared the expression of markers of proliferation (PCNA, cyclin B1), of apoptosis (Bax, caspase-3) and secretory activity (release of progesterone, P(4), and insulin-like growth factor, IGF-I) in whole ovarian follicles and granulosa cells cultured in conditions of normal temperature (37.5 degrees C) and feeding (with serum), high temperature (41.5 degrees C, with serum) and malnutrition (37.5 degrees C, without serum), with and without hormones [IGF-I, leptin and follicle-stimulating hormone (FSH)]. The expression of proliferation and apoptosis markers was evaluated by SDS PAGE-western blotting whereas radioimmunoassay (RIA) measured the release of hormones. High temperature dramatically induced a reduction in both proliferation and apoptosis markers in both ovarian follicles and granulosa cells and induced a significant increase in P(4) and IGF-I release by ovarian granulosa cells but not in P(4) secretion by ovarian follicles. Serum deprivation increased accumulation of cyclin B1 but not other markers of proliferation (PCNA) and apoptosis (Bax, caspase-3) or P(4) release in ovarian follicles. On the contrary, it inhibited the expression of apoptotic marker (Bax), release of both P(4) and IGF-I but it did not affect proliferation marker (PCNA) in granulosa cells. Adding IGF-I, leptin and FSH affected proliferation, apoptosis and secretory activity of ovarian cell functions but also prevented an inhibitory effect of high temperature on the expression of Bax and PCNA and an inhibitory action of serum deprivation on PCNA in ovarian follicles. Furthermore, treatment with these hormones prevented an inhibitory action of thermal stress on Bax, PCNA, P(4) and IGF-I in ovarian granulosa cells. The present observations (1) confirm the involvement of hormones (IGF-I, leptin and FSH) in the control of proliferation, apoptosis and secretory activity of ovarian cells, (2) demonstrate for the first time that heat stress/increased temperature can induce a reduction in ovarian cell proliferation and apoptosis and an oversecretion of ovarian hormones, (3) show that malnutrition/serum deprivation can reduce both apoptosis and secretory activity of ovarian cells, (4) demonstrate the differences in the response of granulosa and other ovarian follicular cells to stresses, and (5) are the first demonstration that hormones (IGF-I, leptin and FSH) could be used for preventing the effect of stresses on ovarian cell functions.

Molecular cloning and gene expression analysis of the leptin receptor in the Chinese mitten crab Eriocheir sinensis

Background

Leptin is an adipocyte-derived hormone with multiple functions that regulates energy homeostasis and reproductive functions. Increased knowledge of leptin receptor function will enhance our understanding of the physiological roles of leptin in animals.

Methodology/Principal Findings

In the present study, a full-length leptin receptor (lepr) cDNA, consisting of 1,353 nucleotides, was cloned from Chinese mitten crab (Eriocheir sinensis) using rapid amplification of cDNA ends (RACE) following the identification of a single expressed sequence tag (EST) clone in a cDNA library. The lepr cDNA consisted of a 22-nucleotide 5′-untranslated region (5′ UTR), a 402-nucleotide open reading frame (ORF) and a 929-nucleotide 3′ UTR. Multiple sequence alignments revealed that Chinese mitten crab lepr shared a conserved vacuolar protein sorting 55 (Vps55) domain with other species. Chinese mitten crab lepr expression was determined in various tissues and at three different reproductive stages using quantitative real-time RT-PCR. Lepr expression was highest in the intestine, thoracic ganglia, gonad, and accessory gonad, moderate in hepatopancreas and cranial ganglia, and low in muscle, gill, heart, haemocytes, and stomach. Furthermore, lepr expression was significantly higher in the intestine, gonad and thoracic ganglia in immature crabs relative to precocious and mature crabs. In contrast, lepr expression was significantly lower in the hepatopancreas of immature crabs relative to mature crabs.

Conclusions/Significance

We are the first to identify the lepr gene and to determine its gene expression patterns in various tissues and at three different reproductive stages in Chinese mitten crab. Taken together, our results suggest that lepr may be involved in the nutritional regulation of metabolism and reproduction in Chinese mitten crabs.

Leptin gene and protein expression in the ovary during the oestrous cycle and early pregnancy in pigs

Leptin, the product of the obese gene, is the hormone originally identified in adipocytes. It is involved in the control of satiety and energy metabolism. More recent observations suggest that leptin plays an important role in reproduction. Leptin mRNA and protein have been found in the human and the murine ovary. However, the expression of leptin in the porcine ovary has not been examined. Therefore, the aim of the present work was to compare the expression levels of porcine leptin mRNA by semiquantitative RT-PCR and in situ hybridization, as well as leptin protein by Western blotting in the corpus luteum (CL) and ovarian stroma (OS) during mid- and late-luteal phase of the oestrous cycle as well as during days 14-16 and 30-32 of pregnancy. Leptin gene and protein expression in CL was increased on days 14-16 of the cycle compared with pregnant animals. Leptin gene expression in OS was higher during the late-luteal phase of the cycle than on days 30-32 after conception. However, comparison of leptin protein expression in OS between days 14-16 of the cycle and days 30-32 of pregnancy indicates a higher protein expression during pregnancy. Moreover, leptin gene expression was higher in porcine CL and OS on days 14-16 of pregnancy in comparison to days 30-32. Contrary to leptin mRNA expression, a higher leptin protein expression was observed on days 30-32 compared with days 14-16 after conception. In summary, the present study provides the first evidence that leptin mRNA and protein occur in porcine ovary and vary during the oestrous cycle and pregnancy. Moreover, the obtained results indicate that also locally synthesized leptin may participate in the control of pig reproduction by exercising its action at the ovarian level.

IMMUNOHISTOCHEMICAL, HISTOLOGICAL AND ULTRASTRUCTURAL EVALUATION OF THE EFFECTS OF LEPTIN ON TESTES IN MICE

This study was undertaken to examine the effects of leptin on testes in mice. For this purpose, 12 male mice were divided into two groups. Animals in Group I were designated as control. Mice in Group II were injected daily with leptin for 5 days. All animals were decapitated at the end of the experiment. The testes were removed and weighed out. Testicular tissue specimens were processed for light and electron microscopic examination and semi-quantitative evaluation of immunohistochemical testosterone staining. Intensity of immunostaining was determined on a scale between 0 (no staining) and 5 (heavy staining). For morphometric comparison, diameters of seminiferous tubules from each group were measured. In the leptin injected group, testicular weights and diameters of seminiferous tubules were significantly increased in comparison to control values. In light microscopic examination, an increase in secretory granules in the cytoplasm of Leydig cells was observed after leptin treatment. In the same group, distinct changes indicative of increased cell activation were seen in the ultrastructure of Leydig cells. Amount of mitochondria, lysosomes and cytoplasmic secretory granules were increased. Furthermore, an increase in extensiveness of rough endoplasmic reticulum was noted in this group. Immunohistochemical testosterone staining of the cytoplasm of Leydig cells was heavy (5+) in the leptin treated mice compared to mild score (2+) in the control mice. Additionally, heavy immunostaining of testosterone was also observed in the interstitial space after injection of leptin. The present findings indicate that testicular functions and synthesis of testosterone increase after administration of leptin.

Postpartum anestrus in dairy cattle

Fertility of the postpartum period is negatively influenced by the incidence of anestrus. The latter condition is characterized by the absence of estrous behavior, which may be an indication of suboptimal conditions (e.g., inadequate peripartum nutrition) or pathologic conditions (e.g., chronic debilitating diseases or uterine and ovarian diseases). Although initiation of ovarian follicular growth in the postpartum period is generally not affected, subsequent development (deviation) and the fate of the dominant follicle are the primary factors that affect reestablishment of ovarian cyclicity. Anestrus can be classified based on the three functional states of follicular development; that is, follicle emergence, deviation, and ovulation. Prevention of anestrus is preferable to treatment and can be achieved in part by maintaining a healthy periparturient period. To better understand the etiology of anestrus and its prevention, research is urgently needed in the following three areas: the role of peripartum disease conditions that influence reproduction, genes involved in ovulation, and the influence of proteins (e.g., leptin) that appear to be important links between metabolic signals and the neuroendocrine axis.

The relationship between nitric oxide and leptin in the lung of rat with streptozotocin-induced diabetes

Lung structural changes and immunoreactivity of endothelial (eNOS)- and inducible nitric oxide synthase (iNOS) were investigated by light microscopy in lungs of treated and untreated diabetic rats. Diabetes was induced by a single intraperitoneal (i.p.) injection of 65 mg kg(-1) streptozotocin (STZ) in Wistar albino male rats. Diabetic rats received daily i.p. doses of dexamethasone (2 mg kg(-1)), leptin (0.5 microg kg(-1)) and intramuscular insulin (20 U kg(-1)) or a combination of these drugs for 1 week starting 4 weeks after the STZ injections. After treatment, the blood levels of glucose, leptin, insulin and nitrate/nitrite (NO(3) (-)/NO(2) (-)) were measured. Dilatation of alveoli and alveolar ducts, partial alveolar wall thickening and increased eNOS- and iNOS characterized the diabetic rat lungs. High blood glucose and nitrate/nitrite levels as well as low insulin and leptin levels were also present. Treatment with insulin, dexamethasone and a combination of these drugs resulted in improvement of the structural and immunohistochemical abnormalities. The most effective treatment was insulin therapy. Leptin administration resulted in increased relative amounts of extracellular material, which led to noticeable respiratory efficiency in the diabetic rat lungs. All treatments except leptin lowered blood glucose levels. The combination of insulin and dexamethasone increased blood leptin and insulin, while the remaining diabetic rats had blood with low leptin and insulin concentrations. These results suggest that therapy with insulin plus dexamethasone but not therapy with leptin is beneficial for diabetics.

Body fat, energy balance and estradiol levels: a study based on hormonal profiles from complete menstrual cycles

BACKGROUND

Female fecundity is regulated by nutritional status. Although widely cited, this hypothesis is not strongly supported by empirical data from non-obese, healthy women of reproductive age.

METHODS

Healthy, reproductive aged women (n = 141) from Southern Poland collected daily morning saliva samples for one complete menstrual cycle. Levels of 17-beta-estradiol were analyzed by radioimmunoassay. Anthropometric measurements, including body fat percentage, were taken randomly with respect to phase of the menstrual cycle. Energy balance was specified based on changes in body fat percentage from the beginning to the end of the observation period.

RESULTS

Women with very low and high body fat had significantly lower levels of E2 compared with women with low and average body fat. In women of very low to average body fat, a 10% increase in body fat was associated with a 5-7 pmol/l increase in estradiol levels. The association between fat percentage and E2 was even stronger in women with positive energy balance, who also showed significant differences between body fat groups in estradiol profiles across whole the menstrual cycle. No such relationship was found in women with negative energy balance.

CONCLUSIONS

In healthy women, we found a non-linear association between body fat and estradiol levels. Both very low and high body fat was associated with decreased estradiol levels. The relationship between estradiol and body fat was strongly influenced by women's energy balance.

Leptin-mediated cell survival signaling in hippocampal neurons mediated by JAK STAT3 and mitochondrial stabilization

Leptin plays a pivotal role in the regulation of energy homeostasis and metabolism, primarily by acting on neurons in the hypothalamus that control food intake. However, leptin receptors are more widely expressed in the brain suggesting additional, as yet unknown, functions of leptin. Here we show that both embryonic and adult hippocampal neurons express leptin receptors coupled to activation of STAT3 and phosphatidylinositol 3-kinase-Akt signaling pathways. Leptin protects hippocampal neurons against cell death induced by neurotrophic factor withdrawal and excitotoxic and oxidative insults. The neuroprotective effect of leptin is antagonized by the JAK2-STAT3 inhibitor AG-490, STAT3 decoy DNA, and phosphatidylinositol 3-kinase/Akt inhibitors but not by an inhibitor of MAPK. Leptin induces the production of manganese superoxide dismutase and the anti-apoptotic protein Bcl-xL, and stabilizes mitochondrial membrane potential and lessens mitochondrial oxidative stress. Leptin receptor-deficient mice (db/db mice) are more vulnerable to seizure-induced hippocampal damage, and intraventricular administration of leptin protects neurons against seizures. By enhancing mitochondrial resistance to apoptosis and excitotoxicity, our findings suggest that leptin signaling serves a neurotrophic function in the developing and adult hippocampus.

Leptin directly controls proliferation, apoptosis and secretory activity of cultured chicken ovarian cells

The aim of our in-vitro experiments was to examine, whether leptin can directly control functions of avian ovarian cells and to outline potential intracellular mediators of its effects. Granulosa cells or fragments of ovarian follicular wall were cultured with leptin (0, 1, 10 or 100 ng/mL medium). The expression of peptides involved in apoptosis (TdT, bax, its binding protein, bcl-2, ASK-1 and p53), cell cycle-related peptides (PCNA and cyclin B1), release of hormones (progesterone, testosterone, estradiol, arginine-vasotocin), as well as the expression of protein kinases (PKA, MAPK/ERK1,2 and CDK/p34) in the ovarian cells were examined by using immunocytochemistry, TUNEL, SDS-PAGE-Western immunoblotting, EIA and RIA. It was found that leptin inhibited expression of all markers of cytoplasmic apoptosis (bax, ASK-1 and p53), stimulated expression of anti-apoptotic peptide bcl-2, but did not affect nuclear DNA fragmentation (TdT). Furthermore, leptin inhibited expression of PCNA (marker of S-phase of mitosis), but not of cyclin B1 (marker of G phase of cell cycle). Moreover, it promoted release of progesterone and estradiol, suppressed release of testosterone, but did not affect arginine-vasotocin. Finally, leptin inhibited expression of MAPK/ERK1,2 and CDK/p34 and stimulated expression of PKA. The present observations demonstrate that leptin can directly control basic chicken ovarian functions - inhibit cytoplasmic apoptosis and proliferation (S-phase, but not G-phases of mitosis), regulate secretory activity (release of steroids, but not nonapeptide hormone) and expression of MAPK, PKA and CDC2, which might be potential intracellular mediators of leptin action.

Serum leptin level in women with unexplained infertility

INTRODUCTION

The aim of this study was to compare serum levels of leptin in women with unexplained infertility with fertile subjects.

MATERIAL AND METHOD

Serum leptin levels of 27 infertile and 30 fertile women on day 3 of the menstrual cycle were assessed and compared in this prospective age and body mass index (BMI) comparable controlled study.

RESULTS

The mean age in the infertile group was 29.3 (range, 23-38), while this figure was 28.9 (range, 19-39) in the fertile group; the mean BMIs were 24.5 (range, 20.6-27.8) and 25.0 (range, 21.8-28.7), respectively. The mean serum leptin level was significantly higher in women with unexplained infertility compared with fertile subjects. Considering normal weight subjects, mean serum leptin levels were increased significantly in the unexplained infertile group compared with the fertile group (7.2 (range, 4.3-10.4) versus 3.5 (range, 1.9-6.2)ng/ml, respectively; p<0.0001, Mann-Whitney U-test). The significant increase in serum leptin levels was observed also in overweight patients (6.8 (range, 1.3-5.2) versus 3.3 (range, 4.2-8.9)ng/ml, respectively; p<0.0001, Mann-Whitney U-test).

CONCLUSION

A significant difference in serum leptin levels between unexplained infertile and fertile women suggests that this cytokine may be involved in pathophysiology of unexplained infertility.

Pulsatile luteinizing hormone amplitude and progesterone metabolite excretion are reduced in obese women

CONTEXT

Female obesity is linked to abnormal menstrual cycles, infertility, reproductive wastage, and deficient LH, FSH, and progesterone secretion.

OBJECTIVE AND DESIGN

To elucidate the reproductive defects associated with obesity, we sampled 18 eumenorrheic (nonpolycystic ovary syndrome) women with a mean +/- sem body mass index of 48.6 +/- 1.4 kg/m2 with daily, first morning voided urine collections, seven of whom also had early follicular phase 12-h, every 10-min blood sampling to assess LH pulses. Daily hormones were compared with 11 eumenorrheic, normal-weight controls. A separate control group of 12 eumenorrheic, normal-weight women was used for the LH pulse studies.

MAIN OUTCOME MEASURES

Assays for LH (serum and urine) and FSH, and estradiol and progesterone metabolites (estrone conjugate and pregnanediol glucuronide; urine) were performed. Daily hormones were meaned and normalized to a 28-d cycle length. LH pulsations were determined using two objective methods. Group means were compared using t tests.

RESULTS

Reduced whole-cycle mean, normalized pregnanediol glucuronide was observed in obese (38.2 +/- 2.1 microg/mg creatine) compared with normal-weight women (181.3 +/- 35.1 microg/mg creatine; P = 0.002), without significant differences in LH, FSH, or estrone conjugate. Early follicular phase LH pulse frequency did not differ from normal-weight women, but both amplitude and mean LH were dramatically reduced in obese women (0.8 +/- 0.1 and 2.0 +/- 0.3 IU/liter) compared with controls (1.6 +/- 0.2 and 3.4 +/- 0.2 IU/liter; P < 0.01).

CONCLUSIONS

A novel defect in the amplitude but not the frequency of LH pulsations appears to underlie the reproductive phenotype of obesity. The deficit in pregnanediol glucuronide appears to exceed the deficit in LH. The patterns of hypothalamic-pituitary-ovarian axis function unique to the obese state differ from other abnormal reproductive states.

Control of energy balance in relation to energy intake and energy expenditure in animals and man: an ecological perspective

In this paper, we consider the control of energy balance in animals and man. We argue that patterns of mammalian feeding have evolved to control energy balance in uncertain environments. It is, therefore, expected that, under sedentary conditions in which the diet is rich in nutrients and abundantly available, animals and man will overeat. This suggests that no physiological defects are needed to induce overweight and ultimately obesity in man. Several considerations arise from these observations. The time period over which energy balance is controlled is far longer than allowed by most experiments. Physiological models of energy balance control often treat excess energy intake as a defect of regulation; ecological models view the same behaviour as part of normal energy balance control in environments where resources are uncertain. We apply these considerations to common patterns of human and animal feeding. We believe that the ecological perspective gives a more accurate explanation for the functionality of excess fat and the need to defend nutrient balance and avoid gross imbalances, as well as explaining hyperphagia in the face of plenty. By emphasising the common features of energy balance control in different mammalian species, the importance of changes in behaviour to accommodate changes in the environment becomes apparent. This also opens up possibilities for the control of body weight and the treatment of obesity in man.