[AdipoRon Effect on Expression of Lipid Metabolism Genes in Cultured Human Primary Macrophages].

Atherosclerosis is characterized by excessive uptake of cholesterol-rich low-density lipoprotein (LDL) by vascular wall macrophages. The macrophages are transformed into foam cells, lipids accumulate in the intima of arteries, atherosclerotic plaques arise, and cardiovascular diseases develop. Adiponectin is an adipose tissue adipokine and possess anti-atherogenic and anti-inflammatory activities, which are mediated by adiponectin binding to its receptors AdipoR1 and AdipoR2. To exert its anti-atherogenic effect, adiponectin may regulate the reverse cholesterol transport and prevent foam cells formation. The small-molecule adiponectin receptor agonist AdipoRon was assumed to modulate expression of reverse cholesterol transport and inflammation genes in human macrophages. Several AdipoRon concentrations (0, 5, 10, and 20 µM) were tested for effect on expression of the lipid metabolism genes ABCA1, ABCG1, APOA1, NR1H3 (LXRα), NR1H2 (LXRß), PPARG, and ACAT1 and the inflammation genes IL6, TNFA, and TLR4 in cultured human primary macrophages and the THP-1 macrophage cell line. Cell viability was measured using the MTS assay. ABCA1, ABCG1, APOA1, NR1H3, NR1H2, PPARG, ACAT1, IL6, TNFA, and TLR4 mRNA levels in human primary macrophages were assessed by real-time PCR. The PPARG and ABCA1 relative mRNA levels were found to increase in human primary macrophages treated with 5 or 10 µM AdipoRon for 24 h. A higher AdipoRon concentration (20 µM) was cytotoxic to macrophages, especially THP-1 cells. The effect of AdipoRon on human macrophages and potential adiponectin receptor agonists are of interest to study in view of the need to develop new approaches to atherosclerosis prevention and treatment.

[The Expression of Genes Encoding ABCA1 and ABCG1 Transporters and PPARγ, LXRß, and RORα Transcriptional Factors in Subcutaneous and Visceral Adipose Tissue in Women with Metabolic Syndrome].

The study aimed to investigate tissue-specific gene expression of ABCA1 and ABCG1, encoding cholesterol transporters, as well as PPARG, LXRß (NR1H2), and RORA, encoding the most important transcriptional regulators of lipid metabolism, in subcutaneous and visceral adipose tissue (SAT and VAT) in women with metabolic syndrome. It was shown that the ABCG1 mRNA SAT/VAT ratio decreases with age and correlates with the development of metabolic syndrome. After age adjustment, women have reduced chances of metabolic syndrome development when ABCG1 gene expression in SAT is higher relative to VAT than women with VAT ABCG1 gene expression higher or comparable to SAT: OR = 0.15 (95% CI 0.03-0.76), p = 0.023. The ABCA1 mRNA SAT/VAT ratio positively correlated with HDL cholesterol levels (after age adjustment ß = 0.350, p = 0.046), therefore individuals with higher ABCA1 mRNA level in SAT relative to VAT had elevated HDL levels. The ABCA1 mRNA level in SAT was decreased in smokers (p = 0.001). There was a negative correlation between the PPARG mRNA level in SAT with body mass index and waist circumference in the general sample (ß = -0.602, p = 0.003 and ß = -0.642, p = 0.001, respectively, after age adjustment). A decrease of the PPARG mRNA SAT/VAT ratio was associated with elevated plasma insulin level and the insulin resistance index HOMA-IR ß = -0.819, p = 0.004 and ß = -1.053, p = 0.008, respectively, after age adjustment). Thus, the study has shown that the ratio of ABCA1, ABCG1, and PPARG genes expression in different types of adipose tissue (SAT/VAT) could be a significant factor that predicts the development of atherogenic dyslipidemia, metabolic syndrome, and insulin resistance in obesity.

Expression of Genes Encoding Nuclear Factors PPARγ, LXRß, and RORα in Epicardial and Subcutaneous Adipose Tissues in Patients with Coronary Heart Disease.

The nuclear factors PPARγ, RORα, and LXRß are involved in transcriptional control of adipogenesis and implicated in glucose and lipid metabolism. In adipose tissues, they regulate inflammation. This study focuses on expression of the PPARG, RORA, and LXRß (NR1H2) genes in epicardial and subcutaneous adipose tissues in patients with coronary heart disease as well as with concomitant abdominal obesity. In patients with coronary heart disease and abdominal obesity, PPARG mRNA level in subcutaneous adipose tissue was reduced in comparison with control group. In patients with total coronary occlusions, LXRß mRNA level in epicardial adipose tissue was reduced, and it positively correlated with plasma HDL cholesterol. Thus, in cases of concomitant abdominal obesity and chronic total coronary occlusions, coronary heart disease is characterized by down-regulated expression of the genes of various transcriptional adipogenesis-regulating factors in adipose tissue.

[Epicardial and subcutenious adipose tissue adiponectin gene expression in coronary artery disease patients].

Aim To determine the expression of adiponectin gene (ADIPOQ) and the content of high-molecular-weight adiponectin (HMWA) in epicardial (EAT) and subcutaneous adipose tissue (SCAT) in patients with ischemic heart disease (IHD).Material and methods Paired samples of EAT and SCAT and blood serum were withdrawn from patients with IHD after bypass surgery and 16 subjects without IHD (comparison group). Matrix RNA (mRNA) level was measured using real-time polymerase chain reaction. HMWA levels in EAT and SCAT were evaluated by Western blotting. Serum adiponectin concentration was measured immunoenzymatically. For all patients, echocardiography was performed to measure the EAT thickness; coronarography was performed to determine severity of coronary atherosclerosis.Results Serum adiponectin concentration was lower in IHD patients than in the comparison group (p<0.001). Levels of ADIPOO gene mRNA and HMWA in SCAT were lower in IHD patients than in the comparison group (р=0.020 and p=0.003, respectively). The HMWA level in EAT was lower with the EAT thickness of 8 mm compared to the HMWA level in IHD patients with EAT ≤8 mm (p=0.034).Conclusion The decreased serum concentration of antiatherogenic adiponectin and the reduced expression of ADIPOQ gene in SCAT (mRNA, HMWA) are associated with IHD.

ITLN1, PPARg AND TNFa GENE EXPRESSION IN VISCERAL ADIPOSE TISSUE.

The adipose tissue is considered today as an endocrine organ in which tissue-specific regulation of gene expression plays a key role in the processes of development of obesity and comorbidities, such as diabetes and cardiovascular disease. The present study is focused on ITLN1, PPARã and TNFá gene expression in intra-abdominal adipose tissue and its effect on the serum levels of omentin 1 and TNFa in individuals with different body mass. It has been shown that serum TNFa level is significantly higher in the subgroup of patients with overweight and obesity (BMI ≥ 25 kg/m2) as compared to individuals with normal body weight (BMI < 25 kg/m2)( p < 0.03). We have demonstrated that the expression level of the PPARã gene is positively correlated with the ITLN1 gene expression level in the intra-abdominal adipose tissue (r = 0.516, p = 0.020). Serum level of omentin 1 positively correlates with PPARã mRNA and protein levels in intra-abdominal adipose tissue (r = 0.550, p < 0.05 and r = 0.581, p < 0.03, respectively). For the subgroup of patients with overweight and obesity, we have shown negative correlation of the level of TNFá mRNA with PPARã and ITLN1 mRNA levels was shown (r = ­0.549, p < 0.05 and r = ­0.475, p < 0.05, respectively). This study is the first to show a correlation relationship between PPARã gene expression level in the intra-abdominal adipose tissue and the expression and secretion levels of omentin 1.

[Genetic Risk Factors of Macrovascular Complications in Patients With Type 2 Diabetes].

High risk of macrovascular complications in patients with type 2 diabetes mellitus (T2DM) is caused by insulin resistance and atherogenic dyslipidemia that may be genetically determined. The aim of this study was to assess the association of polymorphic genetic variants APOA5 (S19W/rs3135506), CETP (Taq1B/rs708272), PON1 (Q192R /rs662) and PPARG (Pro12Ala /rs1801282) with T2DM and macrovascular complications in patients with T2DM resident in Northwestern Russia. We examined 386 patients with T2DM and 199 healthy controls. Genotyping was performed by polymerase chain reaction followed by restriction analysis. The study revealed the protective role of allele 12Ala of PPARG gene against T2DM development (odds ratio [OR]=0.58; 95% confidence interval [CI] 0.39-0.85). B1B1 genotype of CETP was associated with increased risk of stroke in T2DM patients (OR=1.85; 95%CI1.07-3.21). RR genotype of PON1 was associated with increased risk of T2DM with stroke (OR=2.98; 95%CI1.01-8.84). According to study results Pro12Ala (rs1801282) variant of PPARG affected the risk of T2DM; polymorphic variants of CETP (Taq1B/rs708272) and PON1 (Q192R/rs662) contributed to the risk of macrovascular complications of T2DM.

[Role of the ABC transporters A1 and G1, key reverse cholesterol transport proteins, in atherosclerosis].

Atherosclerosis is one of the most common causes of death worldwide. Epidemiology studies firmly established an inverse relationship between atherogenesis and distorted lipid metabolism, in particular, higher levels of total cholesterol, an accumulation of CH-laden macrophages (foam cells), and lower plasma levels of antiatherogenic high density lipoprotein (HDL). It is believed that the reverse cholesterol transport, a process that removes excess cholesterol from peripheral tissues/cells including macrophages to circulating HDL, is one of the main mechanisms responsible for anti-atherogenic properties of HDL. The key proteins of reverse cholesterol transport-ATP-binding cassette transporters A1 (ABCA1) and G1 (ABCG1)-mediate the cholesterol efflux from macrophages and prevent their transformation into foam cells. This review focuses on the role of ABC transporters A1 and G1 in the pathogenesis of atherosclerosis.

[ABCG1 transporter gene expression in peripheral blood mononuclear cells of patients with atherosclerosis].

Accumulation of cholesterol in arterial wall macrophages is a main hallmark of atherosclerosis. The ABCG1 transporter mediates cholesterol efflux to high density lipoproteins (HDL) and plays an important role in macrophage foam cell formation. The goal of our study was to investigate the potential role of ABCG1 in atherosclerosis development in humans. ABCG1 gene expression has been examined in leukocytes, monocytes and monocyte-derived macrophages of patients with atherosclerosis and in the control group. Real time PCR and Western blotting were used to determine ABCG1 mRNA and ABCG1 protein levels. Monocyte ABCG1 mRNA level was inversely correlated with the rate of artery occlusion (r = -0.45, P = 0.016). Patients with 100% artery occlusions had decreased monocyte ABCG1 mRNA levels compared to patients who had smaller plaques and controls (P < 0.05). ABCG1 mRNA (P < 0.001) and ABCG1 protein (P < 0.05) levels in macrophages of patients with coronary artery stenosis were significantly reduced compared to the control group. No significant correlation between the ABCG1 gene expression in mononuclear cells and HDL cholesterol concentration has been found. Our study suggests that decrease in the ABCG1 gene expression in macrophages is associated with atherosclerosis.

[ABCA1 mRNA and protein levels in M-CSF-activated macrophages from patients with arterial stenosis].

ABCA1 transporter is one of the key factors defining the level of antiatherogenic HDL in plasma. It is actively involved in the removal of cholesterol from peripheral tissues by reverse cholesterol transport. However, the influence of the level of ABCA1 mRNA and the level of ABCA1 protein 1 in macrophages in atherosclerosis remains unexplored. Using real time PCR we determined ABCA1 mRNA level in macrophages cultured for 5 days with macrophage colony-stimulating factor (M-CSF). ABCA1 mRNA levels in macrophages from patients with arterial stenosis were increased when compared with the control group, P = 0.04. According to a Western blot analysis ABCA1 protein level in macrophages from patients was significantly lower than in the control group, P = 0.01. Our results suggest that the level of ABCA1 mRNA and level of ABCA1 protein in macrophages may be important factors in the development of atherosclerosis.

[ABCA1 gene expression in peripheral blood lymphocytes and macrophages in patients with atherosclerosis].

ABCA1 transporter is known to play important role in the cholesterol transport from peripheral tissues. However its contribution in atherosclerosis development remains not completely understood. Using Real Time PCR, a significant reduction of ABCA1 mRNA level in leukocytes of patients with atherosclerosis was determined when compared with controls. Mean ABCA1 expression levels in leukocytes for the group of patients and for the control group are 0.57 +/- 0.28 and 0.93 +/- 0.14 (p = 0.02). At the same time we detected a significant increase of ABCA1 mRNA level in macrophages of patients when compared with controls. Mean ABCA1 expression levels in macrophages for the group of patients and for the control group are 1.32 +/- 0.10 and 0.90 +/- 0.14 (p = 0.014). In summary, we suggest that expression level of ABCA1 gene may contribute to the development of atherosclerosis.

[Regulation of ABCA1 and ABCG1 gene expression in the intraabdominal adipose tissue]. / Reguliatsiia ékspressii genov transporterov ABCA1 i ABCG1 v intraabdominal'noi zhirovoi tkani.

Tissue specific expression of genes encoding cholesterol transporters ABCA1 and ABCG1 as well as genes encoding the most important transcriptional regulators of adipogenesis - LXRa, LXRb, PPARg and RORa has been investigated in intraabdominal adipose tissue (IAT) samples.A direct correlation between the content of ABCA1 and ABCG1 proteins with RORa protein level (r=0.480, p<0.05; r=0.435, p<0.05, respectively) suggests the role of the transcription factor RORa in the regulation of IAT ABCA1 and ABCG1 protein levels. ABCA1 and ABCG1 gene expression positively correlated with obesity indicators such as body mass index (BMI) (r=0.522, p=0.004; r=0.594, p=0.001, respectively) and waist circumference (r=0.403, p=0.033; r=0.474, p=0.013, respectively). The development of obesity is associated with decreased IAT levels of RORa and LXRb mRNA (p=0.016 and p=0.002, respectively). These data suggest that the nuclear factor RORa can play a significant role in the regulation of cholesterol metabolism and control IAT expression of ABCA1 and ABCG1, while the level of IAT LXRb gene expression may be an important factor associated with the development of obesity.