Dyslipidemia is an independent risk factor for type 2 diabetes, although exactly which of the many plasma lipids contribute to this remains unclear. We therefore investigated whether lipid profiling can inform diabetes prediction by performing liquid chromatography/mass spectrometry-based lipid profiling in 189 individuals who developed type 2 diabetes and 189 matched disease-free individuals, with over 12 years of follow up in the Framingham Heart Study. We found that lipids of lower carbon number and double bond content were associated with an increased risk of diabetes, whereas lipids of higher carbon number and double bond content were associated with decreased risk. This pattern was strongest for triacylglycerols (TAGs) and persisted after multivariable adjustment for age, sex, BMI, fasting glucose, fasting insulin, total triglycerides, and HDL cholesterol. A combination of 2 TAGs further improved diabetes prediction. To explore potential mechanisms that modulate the distribution of plasma lipids, we performed lipid profiling during oral glucose tolerance testing, pharmacologic interventions, and acute exercise testing. Levels of TAGs associated with increased risk for diabetes decreased in response to insulin action and were elevated in the setting of insulin resistance. Conversely, levels of TAGs associated with decreased diabetes risk rose in response to insulin and were poorly correlated with insulin resistance. These studies identify a relationship between lipid acyl chain content and diabetes risk and demonstrate how lipid profiling could aid in clinical risk assessment.
Exercise provides numerous salutary effects, but our understanding of how these occur is limited. To gain a clearer picture of exercise-induced metabolic responses, we have developed comprehensive plasma metabolite signatures by using mass spectrometry to measure over 200 metabolites before and after exercise. We identified plasma indicators of glycogenolysis (glucose-6-phosphate), tricarboxylic acid (TCA) cycle span 2 expansion (succinate, malate, and * To whom correspondence should be addressed Corresponding authors Robert E. Gerszten, MD Cardiology Division and Center for Immunology & Inflammatory Diseases Massachusetts General Hospital, Room 8307 149 13th Street Charlestown, MA 02129 rgerszten@partners.org Gregory D. Lewis, MD Cardiology Division Massachusetts General Hospital, GRB 800 55 Fruit Street, Boston, MA 02114 glewis@partners.org. Authors contributions: G.D.L conceived the study, designed the experiments, performed primary data analysis and wrote the manuscript. M.J.W. led the effort to recruit and phenotype marathon subjects, L.F. and M.M. recruited subjects, processed samples, and assisted with experimental design. Z.A. and G.C.R. designed and performed the gene expression profiling experiments, A.S., E.Y., X.S., A.A., S.A.C. and C.B.C. developed the metabolic profiling platform, performed mass spectrometry experiments, and analyzed the data, S.C., E.L.M, T.W., and R.S.V. designed experiments and analyzed data from the Framingham Heart Study cohort, R.D. and F.P.R. assisted with statistical analysis and constructed the metabolite interrelatedness dendrogram, E.P.R. contributed to mass spectrometry data analysis and helped to write the manuscript, D.M.S. and M.J.S. contributed to the cardiopulmonary exercise testing metabolic profiling experiment, M.S.S. helped to conceive and design the exercise treadmill testing studies and assisted in data interpretation and in writing the manuscript, R.E.G. conceived of the study, designed experiments, analyzed data, and wrote the manuscript. Competing interests:The authors declare that they have no competing interests. NIH Public Access Author ManuscriptSci Transl Med. Author manuscript; available in PMC 2010 December 27. NIH-PA Author ManuscriptNIH-PA Author Manuscript NIH-PA Author Manuscript fumarate), and lipolysis (glycerol), as well as modulators of insulin sensitivity (niacinamide) and fatty acid oxidation (pantothenic acid). Metabolites that were highly correlated with fitness parameters were found in subjects undergoing acute exercise testing, marathon running, and in 302 subjects from a longitudinal cohort study. Exercise-induced increases in glycerol were strongly related to fitness levels in normal individuals and were attenuated in subjects with myocardial ischemia. A combination of metabolites that increased in plasma in response to exercise (glycerol, niacinamide, glucose-6-phosphate, pantothenate, and succinate) upregulated the expression of nur77, a transcriptional regulator of glucose utilization and lipid metabolism genes in skeleta...
Recent studies using ovarian cancer cells have shown that the catecholamine hormones norepinephrine (norepi) and epinephrine (epi) may influence cancer progression by modulating the expression of matrix metalloproteinases (MMP) and vascular endothelial growth factor (VEGF). The purpose of this study is to determine if the stress hormone norepi can influence the expression of MMP-2, MMP-9, and VEGF in nasopharyngeal carcinoma (NPC) tumors by using three NPC tumor cell lines. The NPC cell lines HONE-1, HNE-1, and CNE-1 were treated with norepi. The effects of norepi on MMP-2, MMP-9, and VEGF synthesis were measured by ELISA; functional MMP activity was measured by the invasive potential of the cells using a membrane invasion culture system whereas functional activity of VEGF was analyzed using a human umbilical vein endothelial cell tube formation assay. Norepi treatment increased MMP-2, MMP-9, and VEGF levels in culture supernatants of HONE-1 cells, which could be inhibited by the B-blocker propranolol. Norepi induced the invasiveness of all NPC cell lines in a dose-dependent manner, which was blocked by CMT-3, an MMP inhibitor, and propranolol. Norepi stimulated the release of functional angiogenic VEGF by HONE-1 cells as well. Finally, HONE-1 cells were shown to express B-adrenergic receptors as did seven of seven NPC biopsies examined. The data suggest that catecholamine hormones produced by the sympatheticadrenal medullary axis may affect NPC tumor progression, in part, through modulation of key angiogenic cytokines.
Studies suggest that stress can be a co-factor for the initiation and progression of cancer. The catecholamine stress hormone, norepinephrine (NE), may influence tumor progression by modulating the expression of factors implicated in angiogenesis and metastasis. The goal of this study was to examine the influence of NE on the expression of VEGF, IL-8, and IL-6 by the human melanoma cell lines, C8161, 1174MEL, and Me18105. Cells were treated with NE and levels of VEGF, IL-8, and IL-6 were measured using ELISA and real-time PCR. The expression of β-adrenergic receptors (β-ARs) mRNA and protein were also assessed. Finally, immunohistochemitry was utilized to examine the presence of β1- and β2-AR in primary and metastatic human melanoma biopsies. We show that NE treatment upregulated production of VEGF, IL-8, and IL-6 in C8161 cells and to a lesser extent 1174MEL and Me18105 cells. The upregulation was associated with induced gene expression. The effect on C8161 cells was mediated by both β1- and β2-ARs. Furthermore, 18 of 20 melanoma biopsies examined expressed β2-AR while 14 of 20 melanoma biopsies expressed β1-AR. Our data support the hypothesis that NE can stimulate the aggressive potential of melanoma tumor cells, in part, by inducing the production VEGF, IL-8, and IL-6. This line of research further suggests that interventions targeting components of the activated sympathetic-adrenal medullary (SAM) axis, or the utilization of β-AR blocking agents, may represent new strategies for slowing down the progression of malignant disease and improving cancer patients’ quality of life.
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