Postpartum circulating cell-free insulin DNA levels are higher in women with previous gestational diabetes mellitus who develop type 2 diabetes in later life

Background. Women with previous gestational diabetes mellitus (GDM) have evidence of postpartum β-cell dysfunction, which increases their risk of developing type 2 diabetes (T2DM) later in life. Elevated levels of circulating cell-free preproinsulin (INS) DNA correlate with dying β-cells in both mice and humans. The aim of this study was to determine if cell-free circulating INS DNA levels are higher in women with previous GDM who develop T2DM. Methods. We used droplet digital (dd) PCR to measure the levels of cell-free circulating methylated and unmethylated INS DNA in plasma from 97 women with normal glucose tolerance (NGT), 12 weeks following an index GDM pregnancy. Women were assessed for up to 10 years for the development of T2DM. Results. In the follow-up period, 22% of women developed T2DM. Compared with NGT women, total cell-free INS DNA levels were significantly higher in women who developed T2DM (P=0.02). There was no difference in cell-free circulating unmethylated and methylated INS DNA levels between NGT women and women who developed T2DM (P=0.09 and P=0.07, respectively). Conclusions. In women with a previous index GDM pregnancy, postpartum levels of cell-free circulating INS DNA are significantly higher in those women who later developed T2DM

Postpartum circulating cell-free insulin DNA levels are higher in women with previous gestational diabetes mellitus who develop type 2 diabetes in later life

Background. Women with previous gestational diabetes mellitus (GDM) have evidence of postpartum β-cell dysfunction, which increases their risk of developing type 2 diabetes (T2DM) later in life. Elevated levels of circulating cell-free preproinsulin (INS) DNA correlate with dying β-cells in both mice and humans. The aim of this study was to determine if cell-free circulating INS DNA levels are higher in women with previous GDM who develop T2DM. Methods. We used droplet digital (dd) PCR to measure the levels of cell-free circulating methylated and unmethylated INS DNA in plasma from 97 women with normal glucose tolerance (NGT), 12 weeks following an index GDM pregnancy. Women were assessed for up to 10 years for the development of T2DM. Results. In the follow-up period, 22% of women developed T2DM. Compared with NGT women, total cell-free INS DNA levels were significantly higher in women who developed T2DM (P=0.02). There was no difference in cell-free circulating unmethylated and methylated INS DNA levels between NGT women and women who developed T2DM (P=0.09 and P=0.07, respectively). Conclusions. In women with a previous index GDM pregnancy, postpartum levels of cell-free circulating INS DNA are significantly higher in those women who later developed T2DM

Serum Concentrations of Soluble Flt-1 Are Decreased among Women with a Viable Fetus and No Symptoms of Miscarriage Destined for Pregnancy Loss

Miscarriage is the most common complication of pregnancy. Pre-clinical miscarriage has an estimated incidence of 30%, whilst clinical miscarriage has an incidence of 12-15%. Two thirds of pregnancies lost to miscarriage are believed to be attributable to defective placentation, thus a number of studies have sought to identify markers of defective placentation that could be used as clinical biomarkers of miscarriage. Decreased soluble FMS-like tyrosine kinase-1 (sFlt1), placental growth factor (PlGF), and soluble endoglin (sEng) in the maternal circulation during the first trimester have recently been proposed as potential markers of pregnancy loss. However, in these studies clinical samples were only obtained once women had presented with symptoms of miscarriage. In this study we prospectively screened serum samples collected from asymptomatic women with a viable fetus. We assessed maternal serum levels of sFlt1, PlGF and sEng across the first trimester of normal pregnancy and compared levels between women who continued to a live birth, to those who subsequently miscarried. Both sFlt1 and PlGF significantly (p≤0.05) increased across gestation in normal pregnancy with serum levels rising from 0.65±0.12 ng/ml at 6 weeks to 1.85±0.24 ng/ml at 12 weeks for sFlt1, and 57.2±19.2 pg/ml to 106±22.7 pg/ml for PlGF. sEng remained unchanged throughout the the first trimester. Importantly we detected a significant (35%, p≤0.05) decrease in sFlt1 levels between our control and miscarriage cohort, however there was significant overlap between cases and controls, suggesting serum sFlt1 is unlikely to be useful as a clinical biomarker in asymptomatic women. Nevertheless, our data suggests a dysregulation of angiogenic factors may be involved in the pathophysiology of miscarriage

Release of proinflammatory cytokines and 8-isoprostane from placenta, adipose tissue, and skeletal muscle from normal pregnant women and women with gestational diabetes mellitus

The aim of this study was to 1) profile the basal release of TNF-alpha, IL-6, IL-8, and 8-isoprostane (a marker of oxidative stress); and 2) investigate the effect of stimulation on the release of cytokines from sc adipose tissue and skeletal muscle from normal pregnant women and women with gestational diabetes mellitus (GDM). Placenta, sc adipose tissue, and skeletal muscle were incubated in the absence (control) or presence of lipopolysaccharide (LPS; 10 mug/ml), TNF-alpha (10 ng/ml), IL-6 (10 ng/ml), or IL-8 (10 ng/ml). After an 18-h incubation, the medium was collected, and the release of TNF-alpha, IL-6, IL-8, and 8-isoprostane was quantified by ELISA. In all three tissues, 8-isoprostane release was greater in women with GDM, and stimulation with LPS increased 8-isoprostane release from adipose and skeletal muscle, but not placenta, obtained from women with GDM. However, in tissues obtained from normal pregnant women, LPS stimulation increased 8-isoprostane release in placenta and had no effect in adipose tissue and skeletal muscle. Their was no difference in the release of TNF-alpha, IL-6, and IL-8 from placenta, adipose tissue, and skeletal muscle obtained from normal pregnant women and women with GDM. Stimulation of placenta, adipose tissue, and skeletal muscle with LPS and TNF-alpha resulted in greater release of IL-6 and IL-8, whereas only LPS increased TNF-alpha release from all three tissues. The data presented in this study demonstrate that there is a differential release of 8-isoprostane from fetal (placenta) and maternal (adipose tissue and skeletal muscle) tissues obtained from normal pregnant women and women with GDM. These data are consistent with the hypothesis that oxidative stress may be involved in the progression and/or pathogenesis of GDM

Release of proinflammatory cytokines and 8-isoprostane from placenta, adipose tissue, and skeletal muscle from normal pregnant women and women with gestational diabetes mellitus

C1 - Journal Articles RefereedThe aim of this study was to 1) profile the basal release of TNF-alpha, IL-6, IL-8, and 8-isoprostane (a marker of oxidative stress); and 2) investigate the effect of stimulation on the release of cytokines from sc adipose tissue and skeletal muscle from normal pregnant women and women with gestational diabetes mellitus (GDM). Placenta, sc adipose tissue, and skeletal muscle were incubated in the absence (control) or presence of lipopolysaccharide (LPS; 10 microg/ml), TNF-alpha (10 ng/ml), IL-6 (10 ng/ml), or IL-8 (10 ng/ml). After an 18-h incubation, the medium was collected, and the release of TNF-alpha, IL-6, IL-8, and 8-isoprostane was quantified by ELISA. In all three tissues, 8-isoprostane release was greater in women with GDM, and stimulation with LPS increased 8-isoprostane release from adipose and skeletal muscle, but not placenta, obtained from women with GDM. However, in tissues obtained from normal pregnant women, LPS stimulation increased 8-isoprostane release in placenta and had no effect in adipose tissue and skeletal muscle. Their was no difference in the release of TNF-alpha, IL-6, and IL-8 from placenta, adipose tissue, and skeletal muscle obtained from normal pregnant women and women with GDM. Stimulation of placenta, adipose tissue, and skeletal muscle with LPS and TNF-alpha resulted in greater release of IL-6 and IL-8, whereas only LPS increased TNF-alpha release from all three tissues. The data presented in this study demonstrate that there is a differential release of 8-isoprostane from fetal (placenta) and maternal (adipose tissue and skeletal muscle) tissues obtained from normal pregnant women and women with GDM. These data are consistent with the hypothesis that oxidative stress may be involved in the progression and/or pathogenesis of GDM

Hypoxanthine-xanthine oxidase down-regulates GLUT1 transcription via SIRT1 resulting in decreased glucose uptake in human placenta

Appropriate foetal growth and development is dependent on adequate placental glucose uptake. Oxidative stress regulates glucose uptake in various tissues. The effect of oxidative stress on placental glucose transport is not known. Thus, the aim of this study was to determine the effect of oxidative stress on glucose uptake and glucose transporters (GLUTs) in human placenta. Human placenta was incubated in the absence or presence of 0.5 mM hypoxanthine+15 mU/ml xanthine oxidase (HX/XO) for 24 h. Gene and protein expressions of the GLUTs were analysed by quantitative RT-PCR and western blotting respectively. Glucose uptake was measured using radiolabelled ((14)C) glucose. HX/XO significantly decreased GLUT1 gene and protein expression and resultant glucose uptake. There was no effect of the antioxidants N-acetylcysteine, catalase and superoxide dismutase or the NF-κB inhibitor BAY 11-0782 on HX/XO-induced decrease in glucose uptake. However, HX/XO treatment significantly decreased both gene and protein expression of SIRT1. In the presence of the SIRT1 activator resveratrol, the decrease in GLUT1 expression and glucose uptake mediated by HX/XO was abolished. Collectively, the data presented here demonstrate that oxidative stress reduces placental glucose uptake and GLUT1 expression by a SIRT1-dependent mechanism

Sulfasalazine and BAY 11-7082 interfere with the nuclear factor-κB and IκB kinase pathway to regulate the release of proinflammatory cytokines from human adipose tissue and skeletal muscle in vitro

There is much evidence to indicate a role for adipocytokines in insulin resistance and/or type 2 diabetes mellitus. In experimental models, oral salicylates, through their ability to interfere with the nuclear factor-kappaB (NF-kappaB) transcription pathway, have been demonstrated to reverse insulin resistance. The aim of this study was to investigate whether NF-kappaB regulates the release of adipocytokines in human adipose tissue and skeletal muscle. Human sc adipose tissue and skeletal muscle (obtained from normal pregnant women) were incubated in the absence (control) or presence of two NF-kappaB inhibitors sulfasalazine (1.25, 2.5, and 5 mM) and BAY 11-7082 (25, 50, and 100 muM). After an 18-h incubation, the tissues were collected, and NF-kappaB p65 DNA-binding activity and IkappaB kinase (IKK-beta) and insulin receptor-beta protein expression were assessed by ELISA and Western blotting, respectively. The incubation medium was collected, and the release of TNF-alpha, IL-6, IL-8, resistin, adiponectin, and leptin was quantified by ELISA. Treatment of adipose tissue and skeletal muscle with sulfasalazine and BAY 11-7082 significantly inhibited the release of IL-6, IL-8, and TNF-alpha; NF-kappaB p65 DNA-binding activity; and IKK-beta protein expression (P < 0.05, by Newman-Keuls test). There was no effect of sulfasalazine and BAY 11-7082 on resistin, adiponectin, or leptin release. Both sulfasalazine and BAY 11-7082 increased the adipose tissue and skeletal muscle expression of insulin receptor-&beta;. The data presented in this study demonstrate that the IKK-&beta;/NF-&kappa;B transcription pathway is a key regulator of IL- 6, IL- 8, and TNF-&alpha; release from adipose tissue and skeletal muscle. Control of the IKK-&beta;/NF-&kappa;B pathway may therefore provide an alternative therapeutic strategy for regulating aberrant cytokine release and thereby alleviating insulin resistance in type 2 diabetes mellitus

Mitogen-activated protein kinase proteins regulate LPS-stimulated release of pro-inflammatory cytokines and prostaglandins from human gestational tissues

The role of pro-inflammatory cytokines and prostaglandins in human labour is well established. Many of the mRNAs stabilised by the MAPK pathway encode inflammatory mediators, suggesting that this kinase pathway plays a major role in the regulation of inflammation. The aim of this study was to determine if the MAPK pathway regulates the inflammatory response in human gestational tissues. Placenta and fetal membranes (n = 5) obtained from pregnant women undergoing Caesarean section before the onset of labour were exposed to LPS, and co-incubated in the absence or presence of 12.5, 25 and 50 mu M U0126 (ERK 1/2 inhibitor), SB202190 (p38 MAPK inhibitor) and SP600125 (INK inhibitor). After 18 h incubation, tissues were collected and ERK 1/2, p38 MAPK, and JNK total and phosphorylated protein expression was assessed by ELISA and/or Western blotting. The incubation medium was collected and TNF-alpha, IL-1 beta, IL-6, IL-8, PGE(2) and PGF(2 alpha). release was quantified by ELISA. Treatment of placenta and fetal membranes with LPS activated all three MAPK proteins. Co-incubation with U0126, SP600125 and SB202190 significantly suppressed LPS-stimulated activation of ERK 1/2, JNK, and p38 MAPK, respectively. All cytokine and prostaglandin release was significantly suppressed by all concentrations of U0126. LPS-stimulated IL-6, TNF-alpha, PGE2 and PGF(2 alpha). release was significantly suppressed by treatment with all concentrations of SB202190, whereas ILS-stimulated IL-1 beta release was only significantly inhibited in the presence of 50 mu M SB202190 and there was no effect of SB202190 on LPS-stimulated IL-8 release. SP600125 significantly repressed LPS-stimulated release of IL-1 beta and TNF-alpha at all concentrations, whereas LPS-stimulated IL-6, PGE(2) and PGF(2 alpha). release were inhibited at 25 and 50 mu M. In conclusion, the MAPK inhibitors used in this study demonstrated differential activity against a range of sequelae commonly associated with inflammation, supporting the therapeutic potential of MAPK inhibitors in pregnancy complications associated with an aberrant inflammatory response. (c) 2007 Elsevier Ltd. All rights reserved

Complement C5a Regulates Prolabor Mediators in Human Placenta

Fulltext embargoed for: 12 months post date of publicationHuman preterm and term parturition is associated with inflammatory cascades in the uteroplacental unit. Activation of the complement cascade releases potent proinflammatory mediators, including the anaphylatoxin C5a, which exerts its biological effects through its receptors, C5AR (also known as CD88) and C5L2, official symbol GPR77. To date, there are few data available on the role of C5a and CD88 in human pregnancy, so the aim of this study was to determine the effect of C5a and CD88 on some key inflammatory pathways involved in human parturition. Placental tissue samples were obtained from normal pregnancies at the time of Cesarean section. Human placental and fetal membranes were incubated in the absence (basal control) or presence of 0.5 μg/ml (~60 nM) human recombinant C5a for 24 h. Concentrations of proinflammatory cytokines, prostaglandins, and 8-isoprostane (a marker of oxidative stress) were quantified by ELISA and secretory matrix metalloproteinases (MMPs) activity by zymography. NFKB DNA binding activity and NFKBIA (IkappaB-alpha; inhibitor of NFKB) protein degradation were analyzed by ELISA and Western blotting, respectively. In the presence of C5a, proinflammatory cytokines (IL6 and IL8), cyclooxygenase (COX)-2; official symbol PTGS2) expression, and subsequent prostaglandin (PGE(2) and PGF(2alpha)), MMP9 enzyme production, and NFKB DNA activation were all significantly increased. The C5a-induced prolabor responses were significantly reduced by treatment with the selective CD88 antagonist PMX53 and the NFKB inhibitor BAY 11-7082. We conclude that C5a upregulates prolabor mediators in human gestational tissues via CD88-mediated NFKB activation