Hypertension, lipoprotein subclasses and lipid transfer proteins in obese children and adolescents.

BACKGROUND: Obesity-related childhood hypertension is associated with disturbances of serum lipids, but less is known about distribution of lipoprotein subclasses and activities of proteins involved in reverse cholesterol transport in hypertensive obese children. Our objective was to determine low-density lipoprotein (LDL) and high-density lipoprotein (HDL) subclasses distribution and activities of lecithin:cholesterol acyltransferase (LCAT) and cholesteryl ester transfer protein (CETP) in hypertensive and non-hypertensive obese children. METHODS: A total of 40 hypertensive and 25 non-hypertensive obese children were enrolled. Lipoprotein subclasses were assessed by polyacrylamide gradient gel electrophoresis. LCAT and CETP activities were determined as a rate of formation and a rate of transfer of cholesteryl esters. RESULTS: Despite of comparable values of serum lipid parameters, a shift toward smaller LDL and HDL subclasses was observed in hypertensive compared to normotensive obese children. Activities of LCAT were similar, but proatherogenic CETP activities were significantly higher in the hypertensive group (p = 0.036). LCAT/net CETP ratio inversely correlated with relative proportion of small, dense LDL particles (ρ = -0.423; p = 0.025) in the group with hypertension. CONCLUSIONS: The results of our study demonstrated a tendency toward altered distribution of lipoprotein subclasses in favor of more proatherogenic particles in childhood hypertension. Also, hypertensive obese children had increased proatherogenic CETP activity.

Downregulation of AdipoR1 is Associated with increased Circulating Adiponectin Levels in Serbian Chronic Kidney Disease Patients.

BACKGROUND: Since the rise in plasma adiponectin levels in chronic kidney disease (CKD) patients has not yet been elucidated, we sought to investigate if patients on hemodialysis (HD) have altered expression of adiponectin receptors in peripheral blood mononuclear cells (PBMCs) compared to healthy subjects. METHODS: This study included 31 patients with chronic kidney disease on HD and 33 healthy subjects (CG). Circulating adiponectin levels were measured by ELISA while AdipoR1 and AdipoR2 mRNA levels in PBMCs were determined by real-time PCR. RESULTS: Plasma adiponectin levels were significantly higher in patients compared to control group (P=0.036). After adjustment for age, BMI and creatinine, this difference became even more significant (P=0.004). In both groups adiponectin correlated with creatinine (CG: r=-0.472, P=0.006; HD: r=-0.375, P=0.038), triglycerides (CG: r=- 0.490, P=0.004; HD: r=-0.488, P=0.005), insulin (CG: r=-0.386, P=0.038; HD: r=-0.506, P=0.012) and high density lipoprotein cholesterol (HDL-C) (CG: r=-0.672, P<0.001; HD: r=-0.584, P=0.001). Significantly lower expression of PBMCs AdipoR1 mRNA was found in patients compared to CG (P=0.034), while AdipoR2 mRNA levels were similarly expressed in PBMCs in both groups. CONCLUSIONS: Complex pathological processes in CKD cause downregulation of AdipoR1 which could ultimately influence AdipoR1 protein levels leading to a state of ≫adiponectin resistance≪.

Higher circulating resistin protein and PBMCs resistin mRNA levels are associated with increased prevalence of small dense LDL particles in coronary artery disease patients.

Recent in vitro experiments have indicated that human resistin increases the number of lipoprotein particles secreted by the human hepatocytes and also influences their quality, in terms of generating more proatherogenic lipid particles. The aim of this study is to investigate associations of plasma resistin and peripheral blood mononuclear cells (PBMCs) resistin messenger RNA (mRNA) levels with different prevalence of small, dense low-density lipoprotein particles (sdLDL) in patients with indications for coronary angiography. This study included 65 patients requiring coronary angiography. There were 41 patients without significant stenosis and 24 patients with significant stenosis in at least one major coronary artery. Circulating resistin was measured by enzyme-linked immunosorbent assay; PBMC resistin mRNA was determined by real-time polymerase chain reaction. The LDL and high density lipoprotein subclasses were determined by gradient gel electrophoresis. Plasma resistin (P = 0.031) and PBMCs resistin mRNA (P = 0.004) were significantly higher in patients with proportion of sdLDL particles ≥ 50%, compared to the group with relative proportion of sdLDL particles < 50%. Plasma resistin correlated positively with creatinine (r = 0.456, P < 0.001) and resistin mRNA (r = 0.298, P = 0.014) but negatively with body mass index (r = -0.254, P = 0.034) and total cholesterol (r = -0.286, P = 0.021). Multiple linear regression analysis revealed LDL particle diameter as the only independent predictor of resistin mRNA (R(2) = 0.258; adjR(2) = 0.190). A significant association between resistin, both PBMCs mRNA and plasma protein, and the relative proportion of sdLDL particles in the circulation of coronary artery disease patients has been established, which implies that increased gene expression of resistin in PBMCs and higher resistin concentration in plasma are related to pro-atherogenic LDL particle phenotype.

Circulating resistin protein and mRNA concentrations and clinical severity of coronary artery disease.

INTRODUCTION: Previous studies have implicated a strong link between circulating plasma resistin and coronary artery disease (CAD). The aim of this study was to evaluate the differences in peripheral blood mononuclear cells (PBMC) resistin mRNA and its plasma protein concentrations between the patients with CAD of different clinical severity. MATERIAL AND METHODS: This study included 33 healthy subjects as the control group (CG) and 77 patients requiring coronary angiography. Of the latter 30 was CAD negative whereas 47 were CAD positive [18 with stable angina pectoris (SAP) and 29 with acute coronary syndrome (ACS)]. Circulating resistin was measured by ELISA; PBMC resistin mRNA was determined by real-time PCR. RESULTS: Resistin protein was significantly higher in the ACS group compared to the CG (P=0.001) and the CAD negative group (P=0.018). Resistin mRNA expression did not vary across the study groups, despite the positive correlation seen with plasma resistin (ρ=0.305, P=0.008). In patients, plasma resistin and PBMC resistin mRNA negatively correlated with HDL-C (ρ=-0.404, P<0.001 and ρ=-0.257, P=0.032, respectively). Furthermore, the highest plasma resistin tertile showed the lowest HDL-C (P=0.006). Plasma resistin was positively associated with serum creatinine (ρ=0.353, P=0.002). CONCLUSION: Significant increase of plasma resistin in patients with ACS compared to CG and CAD negative patients was observed. Despite no change in PBMC resistin mRNA in different disease conditions a positive association between resistin mRNA and resistin plasma protein was evident. Both plasma resistin and PBMC resistin mRNA were negatively associated with plasma HDL-C, and plasma resistin positively with serum creatinine.

Oxidative stress and paraoxonase 1 status in acute ischemic stroke patients.

OBJECTIVE: The connection of oxidative stress with dyslipidemia creates a newly-emerging atherosclerosis risk factor involved in acute ischemic stroke development. This study analyzed the influence of oxidative stress on structural changes of high-density lipoprotein (HDL) particles connected with modification in protective paraoxonase 1 (PON1) activity. METHODS: This study used 185 patients with acute ischemic stroke and 185 apparently healthy controls. Oxidative stress status, PON1 status, lipids and high-sensitivity C-reactive protein (hsCRP) were determined. In isolated HDL lipoprotein fraction we determined selected markers of oxidative stress (malondialdehyde, MDA) and the content of total sulfhydryl (SH) groups. The capability of oxidative and PON1 status parameters to discriminate patients according to survival status was evaluated. RESULTS: Stroke patients had lower HDL-cholesterol than controls and a remarkable fall in PON1 activity (control group-227U/L, survivors-42U/L, lethal outcome group-61U/L, p < 0.001), along with more prominent inflammation. Pronounced oxidative stress and impaired antioxidative protection was present among patients. HDL fraction analysis revealed a significant decrease of SH groups content (control group vs. patients, p < 0.05) and increased in MDA content in patients (lethal outcome vs. control group, p < 0.05). According to logistic regression analysis, the best predictor of disease outcome was oxidative stress marker - prooxidative-antioxidative balance (PAB). CONCLUSIONS: Pronounced oxidative stress in this group of acute ischemic stroke patients probably led to HDL structural changes, which could further cause an alteration or decrease of PON1 activity. Evidence of increased prooxidant level associated with decreased protective, antioxidative factors suggests their mutual involvement in this complex pathology.

Are decreased AdipoR1 mRNA levels associated with adiponectin resistance in coronary artery disease patients?

The aim of the present study was to investigate if circulating adiponectin levels and the expression of AdipoR1 and AdipoR2 in peripheral blood mononuclear cells (PBMC) are altered in coronary artery disease (CAD) patients, with and without significant stenosis, compared to healthy patients. The present study included 69 patients with presenting symptoms of CAD (26 patients with significant stenosis and 43 patients without significant stenosis). The control group (CG) consisted of 33 healthy patients. Circulating adiponectin levels were measured by enzyme-linked immunosorbent assay, whereas AdipoR1 and AdipoR2 mRNA levels in PBMC were determined by real-time polymerase chain reaction. Adiponectin levels were significantly higher in patients with and without significant stenosis compared to the CG (P < 0.001 vs P = 0.006, respectively). Both patient groups had lower AdipoR1 levels compared to the CG (P < 0.001 vs P < 0.001, respectively). There were no significant differences in these parameters between the two patient groups. Adiponectin negatively correlated with body mass index, triglycerides, insulin and homeostasis model assessment of insulin resistance index (HOMA IR), and positively with high-denisty lipoprotein cholesterol in the CG. Glucose, insulin, and the HOMA IR index negatively correlated with adiponectin in patients. A positive correlation between adiponectin receptors was found in patients and the CG. Decreased AdipoR1 mRNA levels and increased circulating adiponectin in advanced stages of CAD, as well as in patients without significant stenosis, compared to the CG, implies that CAD could be related to 'adiponectin resistance'. Despite increased adiponectin, its protective effects could be diminished even in early stages of atherosclerosis.

Gender-related differences in the oxidant state of cells in Fanconi anemia heterozygotes.

Abstract Fanconi anemia (FA) is a rare cancer-prone genetic disorder characterized by progressive bone marrow failure, chromosomal instability and redox abnormalities. There is much biochemical and genetic data, which strongly suggest that FA cells experience increased oxidative stress. The present study was designed to elucidate if differences in oxidant state exist between control, idiopathic bone marrow failure (idBMF) and FA cells, and to analyze oxidant state of cells in FA heterozygous carriers as well. The results of the present study confirm an in vivo prooxidant state of FA cells and clearly indicate that FA patients can be distinguished from idBMF patients based on the oxidant state of cells. Female carriers of FA mutation also exhibited hallmarks of an in vivo prooxidant state behaving in a similar manner as FA patients. On the other hand, the oxidant state of cells in FA male carriers and idBMF families failed to show any significant difference vs. controls. We demonstrate that the altered oxidant state influences susceptibility of cells to apoptosis in both FA patients and female carriers. The results highlight the need for further research of the possible role of mitochondrial inheritance in the pathogenesis of FA.