Association of apolipoprotein M with high-density lipoprotein kinetics in overweight-obese men
ABSTRACT The aim of this study was to investigate associations between plasma apoM concentration and HDL apoA-I and apoA-II kinetics in 60 overweight-obese, insulin resistant men.
Plasma apoM concentration was determined using a sandwich ELISA with two monoclonal antibodies (CV<5%). The kinetics of HDL apoA-I and apoA-II were measured using intravenous administration of D(3)-leucine, gas chromatography-mass spectrometry and multi-compartmental modeling.
Plasma apoM was inversely associated with body mass index and positively associated with plasma total cholesterol, LDL cholesterol and HDL cholesterol (p<0.05). There were no associations between plasma apoM and plasma triglyceride, NEFA, insulin, glucose, HOMA score or adiponectin concentrations. Plasma apoM was positively associated with both apoA-I and apoA-II concentrations (r=0.406, p<0.01 and r=0.510, p<0.01, respectively) and negatively associated with HDL apoA-I and apoA-II fractional catabolic rate (FCR) (r=-0.291, p=0.03 and r=-0.291, p=0.026, respectively). No significant associations were observed between plasma apoM and HDL apoA-I and apoA-II production rate. In multivariate regression models, both plasma apoM and triglycerides were significant, independent predictors of HDL apoA-I FCR (adjusted R(2)=16%, p<0.01) and HDL apoA-II FCR (adjusted R(2)=14%, p<0.01).
ApoM may be a significant, independent predictor of HDL apoA-I and apoA-II catabolism in overweight-obese, insulin resistant men.
- SourceAvailable from: Ramin Homayouni
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- "In our study, we have found that expression of APOM is inversely correlated with weight gain in kidney transplant recipients. This result seems to agree with other, plasma-based studies that have found that APOM expression levels are inversely associated with BMI , and reduced in those with metabolic syndrome , although further work is needed to explore the exact nature of these associations in adipose tissue. "
ABSTRACT: Background The aim of this study was to investigate the association of gene expression profiles in subcutaneous adipose tissue with weight change in kidney transplant recipients and to gain insights into the underlying mechanisms of weight gain. Methodology/Principal Findings A secondary data analysis was done on a subgroup (n = 26) of existing clinical and gene expression data from a larger prospective longitudinal study examining factors contributing to weight gain in transplant recipients. Measurements taken included adipose tissue gene expression profiles at time of transplant, baseline and six-month weight, and demographic data. Using multivariate linear regression analysis controlled for race and gender, expression levels of 1553 genes were significantly (p<0.05) associated with weight change. Functional analysis using Gene Ontology and Kyoto Encyclopedia of Genes and Genomes classifications identified metabolic pathways that were enriched in this dataset. Furthermore, GeneIndexer literature mining analysis identified a subset of genes that are highly associated with obesity in the literature and Ingenuity pathway analysis revealed several significant gene networks associated with metabolism and endocrine function. Polymorphisms in several of these genes have previously been linked to obesity. Conclusions/Significance We have successfully identified a set of molecular pathways that taken together may provide insights into the mechanisms of weight gain in kidney transplant recipients. Future work will be done to determine how these pathways may contribute to weight gain.PLoS ONE 03/2013; 8(3):e59962. DOI:10.1371/journal.pone.0059962 · 3.23 Impact Factor
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ABSTRACT: It has been well documented that apolipoprotein M (apoM) is principally expressed in hepatocytes as well as renal tubular epithelial cells. The importance of apoM in the kidney is unknown. In the present study we examined urinary any apoM after short-term ischemia-reperfusion injury (IRI) of kidney in a rat model. The kidneys of 11 male Sprague-Dawley rats were rendered ischemic for 45 minutes followed by different intervals of reperfusion. Serum and urine apoM concentrations were determined using a dot-blot analysis with specific rabbit anti-human apoM antibodies that cross-react with rat apoM. Serum concentrations of blood urea nitrogen (BUN) and creatinine (Cr) were determined using standard clinical automated analyses. BUN was significantly elevated after 45 minutes of ischemia followed by 24 hours of reperfusion; serum Cr concentrations were also significantly increased at 6 and 24 hours of reperfusion. Interestingly, similar to BUN and Cr, serum apoM concentrations were significantly increased after ischemia for 45 minutes alone and after 2 hours of reperfusion. Urinary apoM concentrations were obviously increased after 2 h as well as 6 hours of reperfusion. apoM showed characteristics of an acute-phase reactive protein; its occurrence in urine may be considered to be a biomarker of acute renal injury.Transplantation Proceedings 07/2013; 45(6):2476-9. DOI:10.1016/j.transproceed.2013.04.009 · 0.95 Impact Factor
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ABSTRACT: Plasma apolipoprotein M (apoM) is potentially anti-atherogenic, and has been found to be associated positively with plasma total, LDL and HDL cholesterol in humans. ApoM may, therefore, be intricately related to cholesterol metabolism. Here, we determined whether plasma apoM is affected by statin or fibrate administration in patients with diabetes mellitus. Fourteen type 2 diabetic patients participated in a placebo-controlled crossover study which included three 8-week treatment periods with simvastatin (40 mg daily), bezafibrate (400 mg daily), and their combination. ApoM was decreased by 7% in response to simvastatin (P<0.05 from baseline and placebo), and remained unchanged during bezafibrate and combined simvastatin+bezafibrate administration. Plasma apoM concentrations correlated positively with apoB-containing lipoprotein measures at baseline and during placebo (P<0.02 to P<0.001), but these relationships were lost during all lipid lowering treatment periods. This study suggests that, even though plasma apoM is lowered by statins, apoM metabolism is to a considerable extent independent of statin- and fibrate-affected pathways involved in cholesterol homeostasis.Atherosclerosis 11/2010; 213(1):247-50. DOI:10.1016/j.atherosclerosis.2010.07.048 · 3.97 Impact Factor