Gestational weight gain, appetite regulating hormones, and metformin treatment in polycystic ovary syndrome: A longitudinal, placebo-controlled study.

OBJECTIVE: To explore mechanisms that modulate gestational weight gain (GWG) in women with polycystic ovary syndrome (PCOS) and healthy controls. DESIGN: Sub-sample of randomised controlled trials (PCOS) combined with a prospective cohort (controls). SETTING: Eleven Norwegian, Swedish, and Icelandic hospitals. POPULATION: Pregnant women with PCOS treated with metformin (PCOS-M, n = 36) or placebo (PCOS-P, n = 37), and healthy pregnant women (HC, n = 15). METHODS: Serum levels of the appetite regulating hormones leptin, ghrelin, allopregnanolone, and soluble leptin receptor (sOB-R) were determined in the first and third trimesters. MAIN OUTCOME MEASURES: Excessive GWG (eGWG) relative to body mass index according to Institute of Medicine (IOM) guideline. Serum leptin/sOB-R ratio, or free-leptin-index (FLI), as biomarker of leptin sensitivity. Serum ghrelin and allopregnanolone levels. RESULTS: The overall prevalence of eGWG was 44% (38/86). Women with eGWG had higher first and third trimester FLI (P < 0.001), and lower third trimester allopregnanolone levels (P = 0.003) versus women with non-eGWG. The prevalence of eGWG was lower in PCOS-M versus PCOS-P (28% versus 62%, odds ratio = 0.4, 95% CI 0.2-0.8, P = 0.005). FLI decreased during pregnancy in PCOS-M (P = 0.01), but remained unaltered in PCOS-P and HC. Ghrelin and allopregnanolone levels were comparable in PCOS-M, PCOS-P and HC throughout pregnancy. CONCLUSION: Excessive GWG is associated with enhanced leptin resistance, and attenuated physiological increase in serum allopregnanolone levels during pregnancy. Metformin reduces the risk for eGWG and improves leptin sensitivity in pregnant women with PCOS. TWEETABLE ABSTRACT: Metformin counteracts excessive weight gain and leptin resistance in pregnant women with polycystic ovary syndrome.

Differential expression of ligands for NKG2D and DNAM-1 receptors by epithelial ovarian cancer-derived exosomes and its influence on NK cell cytotoxicity.

Cancers constitutively produce and secrete into the blood and other biofluids 30-150 nm-sized endosomal vehicles called exosomes. Cancer-derived exosomes exhibit powerful influence on a variety of biological mechanisms to the benefit of the tumors that produce them. We studied the immunosuppressive ability of epithelial ovarian cancer (EOC) exosomes on two cytotoxic pathways of importance for anticancer immunity-the NKG2D receptor-ligand pathway and the DNAM-1-PVR/nectin-2 pathway. Using exosomes, isolated from EOC tumor explant and EOC cell-line culture supernatants, and ascitic fluid from EOC patients, we studied the expression of NKG2D and DNAM-1 ligands on EOC exosomes and their ability to downregulate the cognate receptors. Our results show that EOC exosomes differentially and constitutively express NKG2D ligands from both MICA/B and ULBP families on their surface, while DNAM-1 ligands are more seldom expressed and not associated with the exosomal membrane surface. Consequently, the NKG2D ligand-bearing EOC exosomes significantly downregulated the NKG2D receptor expression on peripheral blood mononuclear cells (PBMC) while the DNAM-1 receptor was unaffected. The downregulation of NKG2D receptor expression was coupled to inhibition of NKG2D receptor-ligand-mediated degranulation and cytotoxicity measured in vitro with OVCAR-3 and K562 cells as targets. The EOC exosomes acted as a decoy impairing the NKG2D mediated cytotoxicity while the DNAM-1 receptor-ligand system remained unchanged. Taken together, our results support and explain the mechanism behind the recently reported finding that in EOC, NK-cell recognition and killing of tumor cells was mainly dependent on DNAM-1 signaling while the contribution of the NKG2D receptor-ligand pathway was complementary and uncertain.

Cytokine mRNA and protein expression by cell cultures of epithelial ovarian cancer-Methodological considerations on the choice of analytical method for cytokine analyses.

PROBLEM: To get a comprehensive picture of cytokine expression in health and disease is difficult, cytokines are transiently and locally expressed, and protein analyses are burdened by biological modifications, technical issues, and sensitivity to handling of samples. Thus, alternative methods, based on molecular techniques for cytokine mRNA analyses, are often used. We compared cytokine mRNA and protein expression to evaluate whether cytokine mRNA profiles can be used instead of protein analyses. METHOD OF STUDY: In kinetic experiments, cytokine mRNA and protein expression of IL-1ß, IL-6, IL-8, TNF-α, and TNF-ß/LTA were studied using real-time RT-qPCR and Luminex® microarrays in the ovarian cancer cell lines OVCAR-3, SKOV-3 and the T-cell line Jurkat, after activation of transcription by thermal stress. In addition, we analyzed IL-6 and IL-8 mRNA and protein in a small number of ovarian cancer patients. RESULTS: Ovarian cancer cells can express cytokines on both mRNA and protein level, with 1-4 hours' time delay between the mRNA and protein peak and a negative Spearman correlation. The mRNA and protein expression in patient samples was poorly correlated, reflecting previous studies. CONCLUSION: Cytokine mRNA and protein expression levels show diverging results, depending on the material analyzed and the method used. Considering the high sensitivity and reproducibility of real-time RT-qPCR, we suggest that cytokine mRNA profiles could be used as a proxy for protein expression for some specific purposes, such as comparisons between different patient groups, and in defining mechanistic pathways involved in the pathogenesis of cancer and other pathological conditions.

Regulation of ghrelin structure and membrane binding by phosphorylation.

The peptide hormone ghrelin requires Ser-3 acylation for receptor binding, orexigenic and anti-inflammatory effects. Functions of desacylghrelin are less well understood. In vitro kinase assays reveal that the evolutionarily conserved Ser-18 in the basic C-terminus is an excellent substrate for protein kinase C. Circular dichroism reveals that desacylghrelin is approximately 12% helical in aqueous solution and approximately 50% helical in trifluoroethanol. Ser-18-phosphorylation, Ser-18-Ala substitution, or Ser-3-acylation reduces the helical character in trifluoroethanol to approximately 24%. Both ghrelin and desacylghrelin bind to phosphatidylcholine:phosphatidylserine sucrose-loaded vesicles in a phosphatidylserine-dependent manner. Phosphoghrelin and phosphodesacylghrelin show greatly diminished phosphatidylserine-dependent binding. These results are consistent with binding of ghrelin and desacylghrelin to acidic lipids via the basic face of an amphipathic helix with Ser-18 phosphorylation disrupting both helical character and membrane binding.

Isolation and Characterization of Exosomes from Cultures of Tissue Explants and Cell Lines.

Exosomes are specialized, nanometer-sized extracellular vesicles of endosomal origin actively secreted into the extracellular space by a variety of cells under normal and pathological conditions. Exosomes have recently emerged as important intercellular communicators and modulators of diverse mechanisms and cellular responses. Characterization of their composition and function will open possibilities for new diagnostic methods and promising therapeutic approaches based on nanobiology. This unit provides a standard isolation procedure for purification of exosomes based on density gradient ultracentrifugation with sucrose. The process of isolating exosomes relies on obtaining proper source fluids/supernatants as well as qualitative and quantitative assessment of the isolated vesicles. The methodological procedures here can be divided in three parts: (1) pre-isolation procedures aiming to obtain fluids containing exosomes, with a focus on protocols for organ explants and cell cultures; (2) a procedure for exosome isolation with several gradient alternatives; and (3) post-isolation procedures for estimating the purity and yield of the exosomal fraction. © 2016 by John Wiley & Sons, Inc.

Maternal Foxp3 expressing CD4+ CD25+ and CD4+ CD25- regulatory T-cell populations are enriched in human early normal pregnancy decidua: a phenotypic study of paired decidual and peripheral blood samples.

PROBLEM: Regulatory T cells (Treg cells), a small subset of CD4(+) T cells maintaining tolerance by immunosuppression, are proposed contributors to the survival of the fetal semiallograft. We investigated Treg cells in paired decidual and peripheral blood (PB) samples from healthy women in early pregnancy and PB samples from non-pregnant women. METHOD OF STUDY: Distribution, location, cytokine mRNA, and phenotype were assessed in CD4(+) CD25(+) Treg cells from paired samples using immunohistochemistry, immunofluorescence, flow cytometry, and real-time quantitative RT-PCR. RESULTS: The presence and in situ distribution of CD4(+) Foxp3(+) Treg cells in decidua are hereby demonstrated for the first time. Three Foxp3(+) cell populations, CD4(+) CD25(++) Foxp3(+), CD4(+) CD25(+) Foxp3(+), and CD4(+) CD25(-) Foxp3(+), were enriched locally in decidua. In contrast, no statistically significant difference in numbers of circulating Treg cells between pregnant and non-pregnant women was found. The Foxp3(+) cells expressed the surface molecules CD45RO, CTLA-4, CD103, Neuropilin-1, LAG-3, CD62L, and TGFß1 mRNA consistent with Treg phenotype. The population of CD4(+) CD25(-) Foxp3(+) cells, not described in human decidua before, was enriched 10-fold compared with PB in paired samples. Their cytokine expression was often similar to Th3 profile, and the Foxp3 mRNA expression level in CD4(+) CD25(-) cells was stable and comparable to that of CD4(+) CD25(+) Treg cells implying that the majority of CD4(+) CD25(-) Foxp3(+) cells might be naïve Treg cells. CONCLUSION: (i) There is a local enrichment of Treg cells in decidua (ii) The exclusive accumulation of decidual CD4(+) CD25(-) Foxp3(+) cells suggests an additional reservoir of Foxp3(+) naïve Treg cells that can be converted to 'classical' Treg cells in uterus.