Ghrelins, obestatin, nesfatin-1 and leptin levels in pregnant women with and without hyperemesis gravidarum

The Role of the Gastric Hormones Ghrelin and Nesfatin-1 in Reproduction

Ghrelin and nesfatin-1 are enteroendocrine peptide hormones expressed in rat X/A-like and human P/D1cells of the gastric mucosa. Besides their effect on food intake, both peptides are also implicated in various other physiological systems. One of these is the reproductive system. This present review illustrates the distribution of ghrelin and nesfatin-1 along the hypothalamus–pituitary–gonadal (HPG) axis, their modulation by reproductive hormones, and effects on reproductive functions as well as highlighting gaps in current knowledge to foster further research.

The Role of the Gastric Hormones Ghrelin and Nesfatin-1 in Reproduction

Ghrelin and nesfatin-1 are enteroendocrine peptide hormones expressed in rat X/A-like and human P/D1cells of the gastric mucosa. Besides their effect on food intake, both peptides are also implicated in various other physiological systems. One of these is the reproductive system. This present review illustrates the distribution of ghrelin and nesfatin-1 along the hypothalamus-pituitary-gonadal (HPG) axis, their modulation by reproductive hormones, and effects on reproductive functions as well as highlighting gaps in current knowledge to foster further research.

The Role of the Gastric Hormones Ghrelin and Nesfatin-1 in Reproduction

Ghrelin and nesfatin-1 are enteroendocrine peptide hormones expressed in rat X/A-like and human P/D1cells of the gastric mucosa. Besides their effect on food intake, both peptides are also implicated in various other physiological systems. One of these is the reproductive system. This present review illustrates the distribution of ghrelin and nesfatin-1 along the hypothalamus–pituitary–gonadal (HPG) axis, their modulation by reproductive hormones, and effects on reproductive functions as well as highlighting gaps in current knowledge to foster further research.

A comparative account of nesfatin-1 in vertebrates

Nesfatin-1 was discovered as an anorexigenic peptide derived from proteolytic cleavage of the prepropeptide, nucleobindin 2 (NUCB2). It is widely expressed in central as well as peripheral tissues and is known to have pleiotropic effects such as regulation of feeding, reproduction, cardiovascular functions and maintenance of glucose homeostasis. In order to execute its multifaceted role, nesfatin-1 employs diverse signaling pathways though its receptor has not been identified till date. Further, nesfatin-1 is reported to be under the regulatory effect of feeding state, nutritional status as well as several metabolic and reproductive hormones. This peptide has also been associated with variety of human diseases, especially metabolic, reproductive, cardiovascular and mental disorders. The current review is aimed to present a consolidated picture and highlight lacunae for further investigation in order to develop a deeper comprehensive understanding on physiological significance of nesfatin-1 in vertebrates.

Levels of glucagon-like peptide 1 in hyperemesis gravidarum

Objective

Glucagon-like peptide 1 (GLP-1), a gut-derived peptide has been reported to have insulin-like effects. Our aim is to examine GLP1 levels in hyperemesis gravidarum (HEG).

Materials-methods

The study population consisted of 2 groups: Group 1 (control subjects) consisted of 22 women with uncomplicated singleton pregnancies in the first trimester. Group 2 consisted of 22 singleton pregnancies complicated by HEG. Glucose and GLP1 levels were determined. Enzyme-linked Immunosorbent Assay Kit for Glucagon like Peptide 1 (GLP1) was used (Uscn, Life Science Inc.).

Results

No significant differences in maternal age, gestational age and gravida were observed between hypermetric and control groups. Maternal serum GLP1 levels were significantly higher in HEG compared with control group (P = 0.004).

Conclusion

The results of our study revealed that the presence of increased GLP1 levels in women with HEG could contribute to the pathogenesis of the disease. Our results indicated that increased GLP1 levels may be associated with hyperemesis gravidarum. The limitation of our study was the restricted number of patients. Large prospective and randomized studies are required to evaluate the effect of GLP1 levels on hyperemesis gravidarum.

Predictive factors of Hyperemesis Gravidarum: A systematic review

PURPOSE

Hyperemesis gravidarum (HG) is the main cause of hospitalization during the first trimester of pregnancy. Although it has been associated with serious complications, little is known about its predictive factors. The aim of this systematic review was to search for and critically appraise the studies that investigate the predictive factors for HG.

METHODS

Search strategy included PubMed, CENTRAL and EMBASE databases (till December 2017). All studies examining risk factors for HG were included. Screening of available studies was carried out by two reviewers, as well as the quality assessment of the included studies, based on the Newcastle-Ottawa Scale for observational studies.

RESULTS

The search located 308 articles, of which 14 observational studies (four low-, eight medium- and two high-quality), involving 1400 women who met the eligibility criteria. In four studies, there was no association between Helicobacter (H.) Pylori infection and HG, in contrast to two studies which demonstrated such an association. Pre-pregnancy body mass index (BMI), adipose tissue, maternal age, leptin, ghrelin, beta-chorionic gonadotropin (β-hCG), total (T₄) and free thyroxine (fT₄) correlated with HG in various studies, and could be considered as predictive markers. Regarding the high-quality evidence, a cohort study associated leptin and nephatin-1 with HG, whereas a cross-sectional study found no association between H. pylori infection and HG.

CONCLUSIONS

More studies of high quality and adequate sample size have to be carried out to identify the predictive factors for HG.

Insulinotropic nucleobindin-2/nesfatin-1 is dynamically expressed in the haemochorial mouse and human placenta

The placenta is the physiological bridge between mother and fetus and has life-sustaining functions during pregnancy, including metabolic regulation, fetal protection and hormone secretion. Nucleobindin-2 (NUCB2) is a calcium- and DNA-binding protein and precursor of nesfatin-1, a signalling peptide with multiple functions, including regulation of energy homeostasis and glucose transport. These are also key functions of the placenta, yet NUCB2/nesfatin-1 expression has never been comprehensively studied in this organ. In the present study, mouse placental samples from Embryonic Day (E) 7.5 to E17.5 and human chorionic villi from the first and second trimester, as well as term pregnancy, were analysed for NUCB2/nesfatin-1 expression by immunohistochemistry with an antiserum that recognised both NUCB2 and nesfatin-1. From E7.5 to E9.5, NUCB2/nesfatin-1 was expressed in the ectoplacental cone, then parietal trophoblast giant cells and early spongiotrophoblast. At E10.5–12.5, NUCB2/nesfatin-1 expression became detectable in the developing labyrinth. From E12.5 and onwards, NUCB2/nesfatin-1 was expressed in the glycogen trophoblast cells, as well as highly expressed in syncytiotrophoblast, sinusoidal trophoblast giant cells and fetal capillary endothelial cells of the labyrinth. In all trimesters of human pregnancy, NUCB2/nesfatin-1 was highly expressed in syncytiotrophoblast. In addition, there was a significant increase in NUCB2 expression in human primary trophoblast cells induced to syncytialise. Thus, the haemochorial mammalian placenta is a novel source of NUCB2/nesfatin-1 and likely a site of its action, with potential roles in glucose homeostasis and/or nutrient sensing.

Concentrations of prealbumin and some appetite-controlling hormones in pregnancies associated with hyperemesis gravidarium

Background Hyperemesis gravidarum, which affects 0.3-2.3% of pregnancies, is defined as excessive vomiting during pregnancy and usually starts in week 4 or 5 of gestation. Symptoms include weight loss, dehydration, ketonaemia, ketonuria, fasting acidosis, alkalosis due to hydrochloric acid loss and hypokalaemia and its exact cause is unknown. The present study was undertaken to investigate the relationship between prealbumin, ghrelin, nesfatin-1 and obestatin concentrations in pregnancies associated with hyperemesis gravidarum. Methods A total of 40 pregnant females with hyperemesis gravidarum and 38 pregnant females without hyperemesis gravidarum as controls were included in this study. Serum concentrations of prealbumin, ghrelin, obestatin and nesfatin-1 were measured. Results There were no significant differences in age, gestational week, gravidity and parity between the two groups. Body mass index was significantly lower in cases than in controls. Serum ghrelin and prealbumin concentrations were significantly lower in cases than in controls ( P  <0.05 and P < 0.001, respectively). There was no significant difference in serum concentrations of obestatin and nesfatin-1 between the two groups. There was no significant association between body mass index and serum ghrelin, nesfatin-1, obestatin or prealbumin concentrations in patients with hyperemesis gravidarum. Conclusions Decreased serum concentrations of ghrelin and prealbumin in patients with hyperemesis gravidarum are independent of body mass index. Based on our results, we believe that ghrelin may be considered to play a role in the aetiopathogenesis of hyperemesis gravidarum and that hyperemesis gravidarum may result in disruption of the relationship between nesfatin-1 and ghrelin. In addition, we believe that the measurement of serum prealbumin may be used for assessing nutritional status in pregnancy.

The evaluation of Nesfatin-1 levels in patients with and without intrauterine growth restriction

OBJECTIVE

To evaluate Nesfatin-1 levels in patients with and without intrauterine growth restriction and to analyze the correlation between Nesfatin-1 levels and fetal birth weights.

METHODS

This study comprised a total of 81 cases; 41 patients with IUGR and 40 healthy cases. Demographic data, pregnancy weeks, fetal birth weights and Nesfatin-1 levels were all recorded. The Nesfatin-1 levels were compared between the groups and the correlation between fetal birth weights and Nesfatin-1 levels was analyzed.

RESULTS

No statistical significant difference was determined between the groups in terms of demographic data (p > 0.05). Average birth weights were determined as 3420 ± 259 g in the control group and 2041 ± 350 g in the IUGR group, which was found to be statistically unequal (p = 0.001). The average Nesfatin levels in the control group were 0.069 ± 0.011 and 0.094 ± 0.042 in the IUGR group. This difference was statistically unequal (p = 0.001). While no correlation was determined between Nesfatin levels and fetal birthweights in the control group (r = -0.034 versus p = 0.836), in the IUGR group and when all the cases were evaluated together, a statistically moderately significant negative correlation was determined (r = -0.469, p = 0.002 and r = -0.251, p = 0.024, respectively).

CONCLUSIONS

Although intrauterine growth is a multifactorial process, the effect mechanism has not yet been established. The results of this study offer some indications about the possible effect of Nesfatin 1 on fetal growth.

Regulatory neuropeptides (ghrelin, obestatin and nesfatin-1) levels in serum and reproductive tissues of female and male rats with fructose-induced metabolic syndrome

Although, the exact mechanisms underlying the development of the metabolic syndrome (MetS) are not still completely understood, obesity, circulated peptide hormone levels and their interaction with genetic factors are considered largely responsible. The purpose of this study is to explore how the levels of ghrelin, obestatin (OBS) and NUCB2/nesfatin-1 (NES)/NUCB2 change in serum and the reproductive tissues of female and male rats with fructose-induced metabolic syndrome, and whether the levels of each hormone is correlated with the hormones involved with fertility. Experiments were conducted on 5-week-old Sprague-Dawley male and female rats assigned to either a control group or a MetS group. Controls were fed standard rat food and water ad libitum, while the MetS group was fed standard food with 10% (v/v) fructose solution added to their drinking water for 12 weeks with a 12/12h photoperiod circle. Then, all animals were sacrificed after a one night fast. Peptides levels in the serum and reproductive tissues of rats were studied using the ELISA method while the immunoreactivity of reproductive system peptide hormones were shown by immunohistochemical staining method. Furthermore, the other biochemical parameters were measured using Konelab-60 equipment and infertility hormones were measured with Immulite2000. Fasting serum insulin, glucose, triglyceride, alanine aminotransferase (ALT), gamma glutamyl transpeptidase (GGT), low-density lipoprotein cholesterol (LDL-C), and total cholesterol (TC) levels were statistically significantly higher, and the amount of high density lipoprotein cholesterol (HDL-C) was significantly lower, in the MetS groups. Serum and tissue supernatant NES levels were significantly higher in the rats with MetS than the control group. Ghrelin, OBS and NES were expressed in the cytoplasm, concentrated around the apical parts of the epithelial cells in the reproductive tissues of the rats. The amounts of ghrelin were lower in the reproductive tissues of the animals with MetS, while NES levels in the same tissues increased. Obestatin also decreased, though not in the seminal glands.

Hypothalamic nesfatin-1/NUCB2 knockdown augments hepatic gluconeogenesis that is correlated with inhibition of mTOR-STAT3 signaling pathway in rats

Nesfatin-1, an 82-amino acid neuropeptide, has recently been characterized as a potent metabolic regulator. However, the metabolic mechanisms and signaling steps directly associated with the action of nesfatin-1 have not been well delineated. We established a loss-of-function model of hypothalamic nesfatin-1/NUCB2 signaling in rats through an adenoviral-mediated RNA interference. With this model, we found that inhibition of central nesfatin-1/NUCB2 activity markedly increased food intake and hepatic glucose flux and decreased glucose uptake in peripheral tissue in rats fed either a normal chow diet (NCD) or a high-fat diet (HFD). The change of hepatic glucose fluxes in the hypothalamic nesfatin-1/NUCB2 knockdown rats was accompanied by increased hepatic levels of glucose-6-phosphatase and PEPCK and decreased insulin receptor, insulin receptor substrate 1, and AKT kinase phosphorylation. Furthermore, knockdown of hypothalamic nesfatin-1 led to decreased phosphorylation of mammalian target of rapamycin (mTOR) and signal transducer and activator of transcription 3 (STAT3) and the subsequent suppressor of cytokine signaling 3 levels. These results demonstrate that hypothalamic nesfatin-1/NUCB2 plays an important role in glucose homeostasis and hepatic insulin sensitivity, which is, at least in part, associated with the activation of the mTOR-STAT3 signaling pathway.

Gastrointestinal and liver disease in pregnancy

This chapter on the gastrointestinal and hepatic systems in pregnancy focusses on those conditions that are frequent and troublesome (gastro-oesophageal reflux and constipation), distressing (hyperemesis gravidarum) or potentially fatal (obstetric cholestasis, acute fatty liver of pregnancy and HELLP (haemolysis, elevated liver enzymes, low platelets) syndrome). It also highlights the clinical challenge obstetricians may face in managing rare conditions such as the Budd-Chiari syndrome, liver transplantation, primary biliary cirrhosis and Wilson disease. The clinical presentation of liver and gastrointestinal dysfunction in pregnancy is not specific, and certain 'abnormalities' may represent physiological changes of pregnancy. Diagnosis and management are often difficult because of atypical symptoms, a reluctance to use invasive investigations and concerns about the teratogenicity of the medications. The best available evidence to manage these conditions is discussed in the chapter.

Multi-functional peptide hormone NUCB2/nesfatin-1

The recently discovered nesfatin-1 is regulated by hunger and satiety. The precursor protein NUCB2 is proteolytically cleaved into three resulting fragments: nesfatin-1, nesfatin-2, and nesfatin-3. The middle segment of nesfatin-1 (M30) is responsible for limiting food intake, while the exact physiological role of nesfatin-2 and nesfatin-3 are not currently known yet. This hormone plays role/roles on diabetic hyperphagia, epilepsy, mood, stress, sleeping, anxiety, hyperpolarization, depolarization, and reproductive functions. This review will address nesfatin, focusing on its discovery and designation, biochemical structure, scientific evidence of its anorexigenic character, the results of the human and animal studies until the present day, its main biochemical and physiological effects, and its possible clinical applications.