vasoactive-intestinal-peptide and Diabetes--Gestational

Gestational diabetes mellitus (GDM) is defined as glucose intolerance that is first diagnosed during pregnancy. Maternal adipose tissue and fetal membranes secrete various molecules that are relevant players in the pathogenesis of GDM. This pilot study aimed to examine whether the expression of the high mobility group box 1 protein (HMGB1) and its receptor for advanced glycation end products (RAGE), and the vasoactive intestinal peptide (VIP) and its receptors (VPAC-1,-2) were modified in pregnant women with GDM.. Fetal membranes (FMs), omental adipose tissue (VAT) explants, and serum samples were obtained from 12 women with GDM and 12 with normal glucose tolerance (NGT) at delivery. The expression of HMGB1, RAGE and VIP, VPAC-1,-2 was detected by Western Blotting in explants; circulating levels and "in vitro" release of HMGB1 and VIP were measured by ELISA tests.. HMGB1 tissue expression was higher in FMs obtained from GDM women (p = 0.02) than in FMs from NGT women. VPAC2 (p = 0.03) and RAGE (p = 0.03) tissue expressions were significantly increased in VAT from GDM subjects. Only FMs of NGT released detectable levels of HMGB1, which was not observed in samples obtained from GDM. VAT of GDM released lower levels of VIP (p = 0.05) than NGT samples.. This study indicates that a fine tuned regulation exists between FMs and VAT throughout pregnancy to maintain immune metabolic homeostasis. In GDM a balance between inflammatory and anti-inflammatory mediators has been observed. Further studies are needed to establish their exact role on fetal and maternal outcomes in GDM.

Topics: Adult; Diabetes, Gestational; Extraembryonic Membranes; Female; HMGB1 Protein; Humans; Intra-Abdominal Fat; Pregnancy; Receptor for Advanced Glycation End Products; Receptors, Vasoactive Intestinal Peptide, Type II; Vasoactive Intestinal Peptide

Among several factors known to modulate embryo implantation and survival, uterine quiescence and neovascularization, maternal immunotolerance through the Th1/Th2 cytokine balance towards a Th2 profile, local regulatory T-cell (Treg) activation, and high levels of progesterone were assigned a prominent role. Vasoactive intestinal peptide (VIP) is a neuroimmunopeptide that has anti-inflammatory effects, promotes Th2 cytokines and CD4(+)CD25(+)FOXP3(+) Treg activation, and stimulates exocrine secretion, smooth muscle relaxation, and vasodilatation favoring uterus quiescence. The goal of the present work was to explore the participation of VIP in the implantation sites of normal and pregnant prediabetic nonobese diabetic (NOD) females, a mouse strain that spontaneously develops an autoimmune exocrinopathy similar to Sjögren's syndrome. Our results indicate a reduction in litter size from the third parturition onwards in the NOD female lifespan with increased resorption rates. Progesterone systemic levels were significantly decreased in pregnant NOD mice compared with BALB/c mice, although the allogeneic response to progesterone by spleen cells was not impaired. VIP receptors, Vipr1 and Vipr2 (Vpac1 and Vpac2), were expressed at the implantation sites and VIP induced leukemia inhibitory factor (LIF) and Treg marker expression in both strains; however, a reduced Vip expression was found in NOD implantation sites. We conclude that the reduced birth rate at 16-week-old NOD mice with a Th1 systemic cytokine profile involves resorption processes with a lower expression of VIP at the sites of implantation, which acts as a local inducer of pro-implantatory LIF and Treg activation.

Topics: Animals; Diabetes, Gestational; Embryo Implantation; Embryo Loss; Female; Immunologic Factors; Litter Size; Male; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Mice, Inbred NOD; Prediabetic State; Pregnancy; Receptors, Vasoactive Intestinal Peptide, Type II; Receptors, Vasoactive Intestinal Polypeptide, Type I; T-Lymphocytes, Regulatory; Vasoactive Intestinal Peptide