Serum kisspeptin is higher in hypertensive than non-hypertensive female subjects and positively correlated with systolic blood pressure

BACKGROUND

Kisspeptin has a major role in reproductive regulation. Furthermore, it is also involved in metabolic and cardiovascular regulation as well as is a potent vasoconstrictor. This study aimed to: 1) determine correlations between serum kisspeptin levels with obesity/metabolic parameters; 2) compare parameters between non-hypertensive ([non-HT] N.=15) and hypertensive ([HT] N.=15) female subjects; and 3) determine correlations between leptin, systolic blood pressure (SBP) or diastolic blood pressure (DBP) with obesity and metabolic factors.

METHODS

Clinical parameters and fasting blood and adipose tissue samples were collected from women undergoing open abdominal surgery.

RESULTS

Serum kisspeptin was not correlated with obesity parameters but was positively correlated with only SBP (P<0.05). Serum kisspeptin, SBP, DBP, body weight, waist circumference, hip circumference, plasma glucose, plasma insulin, the homeostatic model assessment for insulin resistance (HOMA-IR), and height of visceral adipocytes (VA) were higher but the Quantitative Insulin Sensitivity Check Index (QUICKI) was lower in hypertensive compared to non-hypertensive female subjects (P<0.05). Leptin was positively correlated with obesity and metabolic paramters including area, width, and perimeter of subcutaneous adipocytes, and area, width, height, and perimeter of VA (P<0.05) but was negatively correlated the QUICKI (P<0.001). SBP had positive correlations with insulin, glucose, HOMA-IR, and kisspeptin, but had a negative correlation with QUICKI (P<0.05). DBP had positive correlations with body weight, BMI, waist circumference, hip circumference, insulin, glucose, HOMA-IR, and width of VA (P<0.05), but had a negative correlation with the QUICKI (P<0.05).

CONCLUSIONS

Kisspeptin, obesity especially visceral adiposity, and insulin resistance might contribute to increased blood pressure. Further studies are required to reveal the underlying mechanism of kisspeptin on metabolic and cardiovascular regulation.

A Longitudinal Study of the Relationship of Adiponectin with Reproduction in Infertile Women Undergoing IVF/ICSI Treatment, and an Experimental Study in Human Granulosa Cells

This study investigated the roles of adiponectin in IVF treatment during Phase I (the basal stage before gonadotropin administration), Phase II (approximately 8 days after gonadotropin administration), and Phase III (on the ovum pick-up day), as well as the effects of adiponectin on CYP19A1 and the FSH receptor (FSHR) mRNA expression in a human granulosa-like tumor cell line (KGN). In human subjects (a longitudinal study, n = 30), blood samples were collected in all phases, while follicular fluid (FF) was only collected in Phase III. The participants were classified into successful and unsuccessful groups based on the determination of fetal heartbeats. KGN cells were treated with adiponectin/FSH/IGF-1 (an experimental study, n = 3). There was no difference in the adiponectin levels between successful and unsuccessful pregnancies in the FF (Phase III) and in serum (all phases), as well as among the three phases in both groups. Serum FSH (Phase I) was positively associated with serum adiponectin in the unsuccessful group, but it had a negative association in the successful group (all phases). Serum adiponectin and serum FSH (Phase I) were positively correlated in the unsuccessful group, whereas they were negatively correlated (all phases) in the successful group. The serum adiponectin levels (Phase III) were significantly higher than in the FF in unsuccessful pregnancies, but there was no difference in successful pregnancies. FF adiponectin concentrations were negatively correlated with serum LH in successful subjects. In KGN cells, adiponectin had no influence on CYP19A1 and FSHR mRNA expression. High adiponectin levels in serum compared to FF (Phase III) in unsuccessful subjects might negatively impact IVF treatment.

Cissus Quadrangularis enhances UCP1 mRNA, indicative of white adipocyte browning and decreases central obesity in humans in a randomized trial

Obesity is associated with the growth and expansion of adipocytes which could be decreased via several mechanisms. Cissus Quadrangularis (CQ) extract has been shown to reduce obesity in humans; however, its effect on human white adipocytes (hWA) has not been elucidated. This study aimed to investigate the effects of CQ on obesity, lipolysis, and browning of hWA. CQ treatment in obese humans significantly decreased waist circumference at week 4 and week 8 when compared with the baseline values (p < 0.05 all) and significantly decreased hip circumference at week 8 when compared with the baseline and week 4 values (p < 0.05 all). Serum leptin levels of the CQ-treated group were significantly higher at week 8 compared to baseline levels (p < 0.05). In hWA, glycerol release was reduced in the CQ-treated group when compared with the vehicle-treated group. In the browning experiment, pioglitazone, the PPAR-γ agonist, increased UCP1 mRNA when compared to vehicle (p < 0.01). Interestingly, 10, 100, and 1000 ng/ml CQ extract treatment on hWA significantly enhanced UCP1 expression in a dose-dependent manner when compared to pioglitazone treatment (p < 0.001 all). In conclusion, CQ decreased waist and hip circumferences in obese humans and enhanced UCP1 mRNA in hWA suggestive of its action via browning of hWA.

Associations of serum kisspeptin levels with metabolic and reproductive parameters in men

Central kisspeptin action is well known in reproductive regulation; however, its peripheral action is not well understood. This study aimed to 1) compare serum or cerebrospinal fluid (CSF) kisspeptin levels between different body mass index (BMI) groups 2) compare the levels of kisspeptin between serum and CSF, and 3) determine correlations between serum or CSF kisspeptin levels with clinical, metabolic, and reproductive parameters. There were 40 male subjects undergoing operations with lumbar puncture anesthesia. Subgroup analysis was performed to compare between the normal (n = 12), overweight (n = 10), and obese groups (n = 17). One lean subject was recruited for correlation analysis. Serum kisspeptin levels were significantly higher in the obese group when compared to the normal weight and overweight groups even after adjusting for age or diastolic blood pressure (DBP) (p < 0.05 all). Serum leptin levels were significantly higher in the obese group when compared to the normal weight and overweight groups (p < 0.05 all). CSF kisspeptin levels were below the minimum detectable concentration for the assay (<0.06 ng/mL). Serum kisspeptin was positively correlated with body weight, BMI, plasma insulin, the homeostatic model assessment for insulin resistance (HOMA-IR), and serum leptin but was negatively correlated with plasma LH (p < 0.05 all). In conclusion, serum kisspeptin was related to obesity, leptin, insulin, and insulin resistance, while CSF kisspeptin was below the limits of detection. Thus, peripheral kisspeptin might have a role in metabolic regulation.

Epigallocatechin gallate decreases plasma triglyceride, blood pressure, and serum kisspeptin in obese human subjects

Obesity is one of major risk factors increasing chronic diseases including type II diabetes, cardiovascular diseases, and hypertension. The effects of epigallocatechin gallate (EGCG), the major active compound in green tea, on reduced obesity and improved metabolic profiles are still controversial. Furthermore, the effects of EGCG on human adipocyte lipolysis and browning of white adipocytes have not been elucidated. This study aimed to investigate the effects of EGCG on obesity, lipolysis, and browning of human white adipocytes. The results showed that, when compared to the baseline values, EGCG significantly decreased fasting plasma triglyceride levels (P < 0.05), systolic blood pressure (P < 0.05), diastolic blood pressure (P < 0.05), and serum kisspeptin levels (P < 0.05) after 8 weeks of supplement. On the other hand, supplement of EGCG in obese human subjects for 4 or 8 weeks did not decrease body weight, body mass index, waist and hip circumferences, nor total body fat mass or percentage when compared to their baseline values. The study in human adipocytes showed that EGCG did not increase the glycerol release when compared to vehicle, suggesting that it had no lipolytic effect. Furthermore, treatment of EGCG did not enhance uncoupling protein 1 (UCP1) mRNA expression in human white adipocytes when compared with treatment of pioglitazone, the peroxisome proliferator-activated receptor γ (PPAR-γ) agonist, suggesting that EGCG did not augment the browning effect of PPAR-γ on white adipocytes. This study revealed that EGCG reduced 2 metabolic risk factors which are triglyceride and blood pressure in the human experiment. We also showed a novel evidence that EGCG decreased kisspeptin levels. However, EGCG had no effects on obesity reduction in humans, lipolysis, nor browning of human white adipocytes.

Roles of kisspeptin in IVF/ICSI-treated infertile women and in human granulosa cells

Kisspeptin, a crucial central regulator of reproduction, has been used as a trigger in in vitro fertilization (IVF) treatment. This study aimed to investigate the roles of kisspeptin in IVF treatment in infertile females (n = 30); and in steroidogenesis in human granulosa-like tumor cell line (KGN). In the human study, blood was collected at three time points including (1) the beginning of gonadotropin stimulation (Phase I), (2) around eight days after gonadotropin stimulation (Phase II), and (3) on the day of ovum pick-up (Phase III). Follicular fluid (FF) was collected at Phase III. Serum human chorionic gonadotropin (hCG) was measured 15 days after embryo transfer and fetal heart beats were determined around 42 days of menstrual cycle to classify the subjects into successful and unsuccessful groups. FF kisspeptin levels were higher in successful compared with unsuccessful subjects (P < 0.01). Kisspeptin levels were significantly higher in FF than in serum in successful subjects (P < 0.05) but were comparable in unsuccessful subjects. Serum kisspeptin was comparable among three phases in the successful group but its levels in Phase III were significantly lower compared with Phase I in the unsuccessful group (P < 0.01). Serum kisspeptin in Phase II/III had positive correlations with serum E2 in Phases II and III and the outcomes of IVF/intracytoplasmic sperm injection (ICSI) treatment including serum hCG levels. For the cell experiment (n = 3), kisspeptin treatment in the presence of FSH together with IGF-1 enhanced CYP19A1 (aromatase) mRNA expression compared with control. FSH alone increased aromatase concentrations in the supernatant compared with control and kisspeptin at the dose of 10^-2 mmol/L with FSH enhanced aromatase concentrations in the supernatant compared with FSH alone (P < 0.001 all). In conclusion, kisspeptin enhanced aromatase expression and secretion and was associated with positive outcomes of IVF/ICSI treatment. Further studies regarding supplementation of kisspeptin could reveal its beneficial effects on IVF/ICSI treatment.

MON-012 The Direct Effect of Kisspeptin on Human Ovarian Granulosa Cells to Regulate Steroidogenesis

Kisspeptin has a central role to stimulate the hypothalamic-pituitary-gonadal (HPG) axis. Furthermore, a previous study has suggested that kisspeptin might have a peripheral role in follicular development (1). This study aimed to 1) explore the effect of kisspeptin on CYP19A1 (aromatase) mRNA expression in human granulosa cells and aromatase concentrations in the supernatant; and 2) investigate the effect of kisspeptin on FSHR mRNA expression in human granulosa cells. In this study, human granulosa-like tumor cell line (KGN) (n=3) was incubated for 24 hours with FSH (10^-8 M); FSH with IGF-1 (10^-8 M); different doses of kisspeptin including 1, 10, 100, 1,000, and 10,000 nM; FSH with different doses of kisspeptin; and FSH with IGF-1 together with different doses of kisspeptin. FSH treatment alone or FSH with IGF-1 did not increase CYP19A1 mRNA expression when compared to control. Interestingly, kisspeptin treatment at the doses of 100 nM (P=0.028), 1,000 nM (P=0.005), and 10,000 nM (P=0.009) in the presence of FSH together with IGF-1 enhanced CYP19A1 mRNA expression when compared with control. Furthermore, FSH or FSH with IGF-1 or FSH with all doses of kisspeptin or FSH with IGF-1 together with all doses of kisspeptin increased aromatase concentrations in the supernatant when compared to control (P<0.01 all). Surprisingly, kisspeptin at the dose of 10,000 nM with FSH or FSH together with IGF-1 statistically increased aromatase concentrations in the supernatant when compared with FSH treatment alone or FSH with IGF-1 treatment (P<0.01 all). FSHR mRNA expression was comparable between control and all treatments. As a result, kisspeptin combined with FSH and IGF-1 could enhance CYP19A1 mRNA expression in human granulosa cells and the high dose of kisspeptin (10,000 nM) might be able to augment aromatase secretion in the supernatant. These results suggest that kisspeptin might enhance aromatase expression and secretion, which probably leads to enhance estrogen synthesis. Further studies regarding kisspeptin treatment on estrogen synthesis or secretion in human granulosa cells should be confirmed. Reference: (1) Fernandois D, et al. J Endocrinol. 2016;228(3):161-70.

SAT-019 The Associations of Kisspeptin with Reproductive Hormones and Oocyte Maturation in Infertile Patients Who Underwent IVF Treatment

Kisspeptin has been recognized as a stimulatory factor of the hypothalamic-pituitary-gonadal (HPG) axis. Kisspeptin has been successfully used to trigger ovulation in in vitro fertilization (IVF) treatment (1). This study aimed to 1)compare reproductive hormones (FSH, LH, estradiol, progesterone, and AMH), serum and follicular fluid kisspeptin between successful and unsuccessful clinical pregnancy in different stages of IVF treatment; 2) determine the correlations of serum or follicular fluid kisspeptin with reproductive hormones as well as biochemical and clinical outcomes; and 3) compare the levels of kisspeptin between serum and follicular fluid. In this study, 30 infertile female patients (age 26–40 years old) undergoing IVF treatment were recruited. Blood samples were collected at 3 different time points, the beginning of gonadotropin stimulation (the early follicular phase or T1), the scheduled day for ovum pick-up (OPU) (the late follicular phase or T2), and the day of OPU (T3). Meanwhile, biochemical and clinical parameters including the number of retrieved oocytes, matured oocytes, 2 pronuclear (2PN), and serum hCG were also determined. Moreover, fetus heart beat at 6 weeks of gestation was measured to classify the subjects into successful (n=10) and unsuccessful (n=20) clinical pregnancies. Serum AMH at T1 was significantly higher but serum FSH at T1 and T2 was significantly lower in the success group compared with the unsuccess group (P&lt;0.05 all). Serum kisspeptin at T2 (P=0.09) and serum estradiol at T3 (P=0.05) tended to be higher in the success group compared with non-success group. Serum kisspeptin at T1 had negative correlations with the number of retrieved oocytes (R=-0.511), matured oocytes (R=-0.388), and 2PN (R=-0.451) (P&lt;0.05 all). Serum kisspeptin at T2 had positive correlations with serum LH at T2 (R=0.455), serum kisspeptin at T3 (R=0.645), the number of retrieved oocytes (R=0.465), matured oocytes (R=0.432), and 2PN (R=0.445), and serum hCG levels (R=0.438) (P&lt;0.05 all). Serum kisspeptin at T3 had positive correlations with serum estradiol at T3 (R=0.380), the number of retrieved oocytes (R=0.601), matured oocytes (R=0.565), and 2PN (R=0.562) (P&lt;0.05 all). Follicular fluid kisspeptin levels had a negative correlation with serum FSH at T3 (R=-0.482) but a positive correlation with the number of matured oocytes (R=0.407) (P&lt;0.05 all). Kisspeptin levels in the follicular fluid (3.34 ± 3.74 ng/ml) were significantly higher than in serum at T3 (0.51 ± 0.13 ng/ml) (P&lt;0.01). As a result, kisspeptin at T2 was positively correlated with LH and clinical outcomes, suggesting that kisspeptin might play a role in augmentation of pre-ovulatory LH surge, improvement of oocyte maturation, and ovulation.

Thus, kisspeptin might be used as a potential predictor of successful IVF treatment. Reference: (1) Abbara A, et al. J Clin Endocrinol Metab. 2015;100(9):3322–31.

Placental expressions and serum levels of adiponectin, visfatin, and omentin in GDM

AIMS

Adiponectin, visfatin, and omentin have been shown to be associated with insulin sensitivity and might have a role in the pathophysiology of gestational diabetes mellitus (GDM). This study aimed to (1) compare adiponectin, visfatin, and omentin mRNA expressions in placenta and their serum levels between normal pregnancy (NP) and GDM class A1 (GDMA1) pregnancy and (2) determine correlations between placental gene expressions as well as serum levels with maternal and neonatal clinical parameters in all, NP, and GDM subjects.

METHODS

NP subjects (n = 37), who had normal medical history during their pregnancies without diagnosis of any abnormalities and GDMA1 subjects (n = 37), who were diagnosed since they had antenatal care, were recruited when they were in labor with a gestational age of at least 34 weeks. Clinical parameters and serum adiponectin, visfatin, and omentin levels were measured in the delivery room.

RESULTS

GDMA1 subjects had higher serum visfatin and plasma glucose levels, but lower serum omentin levels (p  < 0.05 all) compared to controls, with comparable levels of placental adiponectin, visfatin, and omentin expressions, plasma insulin, and indices of insulin sensitivity and insulin resistance. Serum visfatin was negatively correlated with neonatal weight and length in the GDM group (p  < 0.05 all). Serum omentin was negatively correlated with pre-pregnancy body mass index and waist circumference only in the NP group (p  < 0.05 all). Serum adiponectin was negatively correlated with maternal age and HOMA-IR in the NP group (p  < 0.05 all) and with placental weight and serum omentin in the GDM group (p  < 0.05 all).

CONCLUSIONS

In conclusion, in GDMA1, increased serum visfatin, which has insulin-mimetic effect, might be associated with a compensatory mechanism that improves the impaired insulin function. Decreased serum omentin in GDMA1, which is normally found in visceral obesity, might lead to insulin resistance and contribute to the pathophysiology of GDM.