Systems Approach to Study Associations between OxLDL and Abdominal Aortic Aneurysms.

Although abdominal aortic aneurysm (AAA) is a common vascular disease and is associated with high mortality, the full pathogenesis of AAA remains unknown to researchers. Abdominal aortic aneurysms and atherosclerosis are strongly related. Currently, it is more often suggested that development of AAA is not a result of atherosclerosis, however, individual factors can act independently or synergistically with atherosclerosis. One of such factors is low-density lipoprotein (LDL) and its oxidized form (oxLDL). It is known that oxLDL plays an important role in the pathogenesis of atherosclerosis, thus, we decided to examine oxLDL impact on the development of AAA by creating two models using Petri-nets. The first, full model, contains subprocess of LDL oxidation and all subprocesses in which it participates, while the second, reduced model, does not contain them. The analysis of such models can be based on t-invariants. They correspond to subprocesses which do not change the state of the modeled system. Moreover, the knockout analysis has been used to estimate how crucial a selected transition (representing elementary subprocess) is, based on the number of excluded subprocesses as a result of its knockout. The results of the analysis of our models show that oxLDL affects 55.84% of subprocesses related to AAA development, but the analysis of the nets based on knockouts and simulation has shown that the influence of oxLDL on enlargement and rupture of AAA is negligible.

[The impact of chromatin modification on the development of chronic complications in patients with diabetes]. / Wplyw modyfikacji struktury chromatyny na rozwój przewleklych powiklan cukrzycowych.

Diabetes is a chronic, metabolic disease. Over 347 million people worldwide have diabetes. Chronic complications (retinopathy, nephropathy or neuropathy) are the major dangerous outcome of this disease. Recent studies indicate a significant role of epigenetic regulation in the development of chronic complications in patients with diabetes. Hyperglycemia could cause abnormal regulation of the activity of enzymes participating in the post-translational histone modifications (PTHMs) and initiation of changes in patterns of DNA methylation. It leads to modification of chromatin structure. These epigenetic abnormalities result in changes in the expression of genes involved in development of chronic inflammation, such as NF-KAPPAB (nuclear factor kappaB gene), TNFα (tumor necrosis factor a gene), IL6 (interleukin 6 gene) or MCP1 (monocyte chemoattractant protein 1 gene). It enhances endothelial cell dysfunction, which plays an important role in development of chronic, diabetic complications. In addition, caused by hyperglycemia epigenetic modifications changes in structure of chromatin explains "metabolic memory", a phenomenon of presence of pathological pathways related to the prolonged hyperglycemia in the past, despite maintaining good metabolic control later on.

Association investigation of BACH2 rs3757247 and SOD2 rs4880 polymorphisms with the type 1 diabetes and diabetes long-term complications risk in the Polish population.

Genetic factors are indicated in the development of type 1 diabetes (DM1). Recently, nucleotide variants of BACH2 and SOD2 have been associated with this chronic condition. Therefore, the purpose of the present study was to investigate the contribution of BACH2 rs3757247 and SOD2 rs4880 (Ala16Val) polymorphisms to the risk of DM1 and diabetes long-term complications. Selected polymorphic variants of BACH2 and SOD2 were investigated in a group of 141 patients with DM1 and in a group of age, gender-matched healthy subjects (n=369) using a high-resolution melting curve method. There was no evidence for either allelic or genotypic association with the risk of DM1 and diabetes chronic complications for analysed polymorphisms. In addition, no interaction between BACH2 and SOD2 variants in the development of this condition was observed. However, the frequency of BACH2 rs3757247 AG and AA genotypes was statistically different between DM1 patients with retinopathy and healthy individuals (odds ratio, 2.455; 95% confidence interval, 0.999-6.035; P=0.044), but this result did not survive multiple testing corrections. The present study did not confirm the involvement of BACH2 rs3757247 and SOD2 rs4880 polymorphisms in the development of DM1 and diabetes long-term complications. Further studies in a larger population sample are required.

Role of epigenetic mechanisms in the development of chronic complications of diabetes.

There is growing evidence that epigenetic regulation of gene expression including post-translational histone modifications (PTHMs), DNA methylation and microRNA (miRNA)-regulation of mRNA translation could play a crucial role in the development of chronic, diabetic complications. Hyperglycemia can induce an abnormal action of PTHMs and DNA methyltransferases as well as alter the levels of numerous miRNAs in endothelial cells, vascular smooth muscle cells, cardiomyocytes, retina, and renal cells. These epigenetic abnormalities result in changes in the expression of numerous genes contributing to effects such as development of chronic inflammation, impaired clearance of reactive oxygen species (ROS), endothelial cell dysfunction and/or the accumulation of extracellular matrix in the kidney, which causing the development of retinopathy, nephropathy or cardiomyopathy. Some epigenetic modifications, for example PTHMs and DNA methylation, become irreversible over time. Therefore, these processes have gained much attention in explaining the long-lasting detrimental consequences of hyperglycaemia causing the development of chronic complications even after improved glycaemic control is achieved. Our review suggests that the treatment of chronic complications should focus on erasing metabolic memory by targeting chromatin modification enzymes and by restoring miRNA levels.

Expression of mitochondrial superoxide dismutase in polymorphonuclear leukocytes from patients with type 1 diabetes with and without microvascular complications.

INTRODUCTION: One of the causes of impaired antioxidant response in patients with type 1 diabetes might be decreased expression of mitochondrial manganese superoxide dismutase (MnSOD). OBJECTIVES: The aim of this study was to evaluate the expression of MnSOD on transcript and protein levels in polymorphonuclear leukocytes (PMNLs) from patients with type 1 diabetes and analyze its association with microvascular complications. PATIENTS AND METHODS: The MnSOD expression was assessed in PMNLs from 46 patients with type 1 diabetes and 12 age- and sex -matched healthy subjects. The study group was divided into 2 subgroups: with and without microvascular complications. The MnSOD expression on the transcript level was evaluated by real -time quantitative polymerase chain reaction, while that on the protein level by Western blot analysis. RESULTS: A significant increase in the MnSOD transcript level was observed in all patients with diabetes with and without microvascular complications (P = 0.01, P = 0.02, respectively). The MnSOD protein level was higher in patients without microvascular complications compared with those with complications and the control group (P = 0.05, P = 0.03, respectively). The MnSOD expression was positively correlated with fasting plasma glucose and total cholesterol levels both at the transcript level (r = 0.4, P <0.05 for both correlations) and at the protein level (r = 0.3 and r = 0.4, respectively, P <0.05). CONCLUSIONS: Although an increased MnSOD transcript level in patients with type 1 diabetes suggests enhanced antioxidant mobilization in all diabetic patients, decreased levels of the MnSOD protein in PMNLs from patients with microvascular complications compared with those without complications indicates that patients with microvascular complications may have impaired antioxidant response.

Effect of surgical treatment on lipid peroxidation parameters and antioxidant status in the serum of patients with peripheral arterial disease.

The various risk factors for peripheral arterial disease (PAD) are almost identical to those for atherosclerosis and include abnormal levels of lipids or lipoproteins. Lipid peroxidation parameters and total antioxidant capacity in the serum of male patients with PAD before surgery as well as 3-5 days and 7-10 days after surgery were measured. We also compared these parameters with those in a group of patients receiving simvastatin therapy. Concentrations of lipid hydroperoxides (LOOHs) and malondialdehyde, the total antioxidant capacity (assessed by ferric reducing antioxidant power assay), concentration of thiol (-SH) groups, and ceruloplasmin activity were determined spectrophotometrically in PAD patients treated surgically (Group I) or pharmacologically (Group II). The patients before surgical treatment had significantly higher concentrations of malondialdehyde but lower ceruloplasmin activity than those observed in Group II, treated with simvastatin. No significant differences before surgery in ferric reducing antioxidant power or thiol concentrations were found between the two groups. However, in Group I, both ferric reducing antioxidant power and thiol group concentrations decreased 3-5 days postoperatively, and ceruloplasmin activity increased 7-10 days after surgical treatment. The presented results demonstrate diverse oxidative stress responses to surgical treatment and confirm the beneficial effects of statin therapy in PAD.

Association between IL-6 concentration and diabetes-related variables in DM1 patients with and without microvascular complications.

Interleukin 6 (IL-6) plays an important role in the initiation and acceleration of chronic inflammation and could contribute to development of microvascular complications in patients with type 1 diabetes (DM1). Therefore, this study was aimed to investigate the association between concentration of IL-6 in relation to glucose control, lipid profile, and body mass index (BMI) in 69 DM1 patients subdivided according to the absence or presence of microvascular complications. BMI, level of fasting plasma glucose (FPG), and concentrations of total cholesterol (TCH), LDL cholesterol (LDL-C), and IL-6 were higher in DM1 patients compared to the control group. In DM1 patients, IL-6 concentration was positively correlated with level of FPG, LDL-C, TCH concentrations, and BMI. These correlations were stronger in the subgroup of patients with microvascular complications. In addition, BMI independently influences IL-6 concentration in DM1 patients. In conclusion, elevated IL-6 concentration is associated with diabetes-related variables which could accelerate progression of microvascular complications in DM1 patients.

Does oxidized LDL contribute to atherosclerotic plaque formation and microvascular complications in patients with type 1 diabetes?

OBJECTIVE: The aim of the study was to investigate whether changes in the level of oxidized LDL (oxLDL) over 2-years contribute to the development of subclinical macroangiopathy and/or microvascular complications in patients with DM1. DESIGN AND METHODS: Basic clinical and biochemical parameters and oxLDL level were measured in 70 patients at baseline and after 2 years of the study. In addition, an ultrasonographic study was performed to assess the carotid intima media thickness (IMT). RESULTS: Patients did not differ according to basic clinical and biochemical parameters at the beginning and after 2 years of the study. IMT increased (p=0.000001) whereas oxLDL level decreased (p=0.00001) in DM1 patients during 2 years. Multivariate regression analysis showed that oxLDL independently influences IMT in DM1 patients (ß=0.454, R2=0.35). Further, positive correlations between oxLDL value and LDL-C concentration (r=0.585, p<0.05, n=70) and between oxLDL level and apo-B concentration have been established (r=0.610, p<0.05, n=70). Moreover, patients with chronic microvascular complications showed a higher value of IMT in comparison with patients without them (p=0.003). CONCLUSION: Our results provide the evidence that oxLDL accelerates atherosclerotic plaque formation and may contribute to the development of microvascular complications in DM1.

Evaluation of paraoxonase 1 arylesterase activity and lipid peroxide levels in patients with type 1 diabetes.

INTRODUCTION: Poor metabolic control of type 1 diabetes is one of the most important factors accelerating the development of late diabetic complications. Several other factors that might contribute to this process are currently being investigated. Low paraoxonase 1 (PON1) activity and high lipid peroxide (LPO) levels contribute to endothelial damage, but it remains unclear whether they are critical for the development of late diabetic complications. OBJECTIVES: The aim of the study was to evaluate PON1 arylesterase activity and LPO levels in patients with type 1 diabetes and to investigate whether these parameters are associated with metabolic control and late complications. Moreover, we aimed to establish whether PON1 activity and LPO levels differ between women and men with type 1 diabetes. PATIENTS AND METHODS: The study involved 80 patients with type 1 diabetes and 24 healthy subjects. PON1 activity was measured by a spectrophotometric method. LPO levels were measured by a commercial assay kit. RESULTS: Diabetic patients had lower PON1 activity and higher LPO levels than healthy people. We observed a negative correlation between PON1 activity and LPO levels in diabetic patients. There was no association between PON1 activity or LPO levels and metabolic parameters or late diabetic complications. There was a positive correlation between LPO levels and the body mass index (BMI) in women with type 1 diabetes. CONCLUSIONS: Our study showed that low PON1 activity and high LPO levels are not the most critical factors involved in late diabetic complications in type 1 diabetes. Increased LPO levels in women with type 1 diabetes may result from enhanced lipogenesis in this subgroup compared with diabetic men.

Relation of salivary antioxidant status and cytokine levels to clinical parameters of oral health in pregnant women with diabetes.

OBJECTIVE: Both pregnancy and diabetes are thought to predispose to the impairment of oral health. As saliva contributes to oral homeostasis, we have characterised its properties and flow rate in pregnant women with or without diabetes. DESIGN: Unstimulated whole mixed saliva was collected from 63 women in the first trimester of pregnancy and analysed for the concentration of selected antioxidants, cytokines, and growth factors. RESULTS: Pregnant women with diabetes were found to have markedly increased indexes of caries activity, plaque formation, gingival and periodontal status, as well as increased salivary antioxidant capacity and pro-inflammatory cytokine levels. These changes were more pronounced in patients with long-term disease and systemic diabetic complications, but only partly correlated with the level of blood glycated haemoglobin. Of the cytokines examined, salivary VEGF and HGF concentrations in diabetic pregnant women correlated in a positive and negative manner, respectively, with the prevalence of caries. Moreover, VEGF levels in this group correlated inversely with the probing depth and clinical attachment levels. All such associations did not occur in healthy individuals. In contrast, the salivary pH and flow rate correlated inversely with several parameters of caries and plaque formation irrespectively of whether the pregnant women were diabetic or not. CONCLUSIONS: Diabetes in pregnant women significantly changes saliva properties, which may contribute to accelerated deterioration of the oral status in this population.

The relationship between concentrations of magnesium and oxidized low density lipoprotein and the activity of platelet activating factor acetylhydrolase in the serum of patients with type 1 diabetes.

The study was aimed at comparing the concentration of metabolic parameters, the serum concentration of oxidized low density lipoproteins (oxLDL) and the activity of platelet activating factor acetylhydrolase (PAF-AH) in the relation to the serum concentration of magnesium (Mg) in patients with type 1 diabetes (DM1). DM1 patients (n=78) were divided into 2 groups: patients with low serum Mg concentration (<0.7 mmol/L, group 1, n=34) and patients with reference levels of Mg (>or=0.7 mmol/L, group 2, n=44). A control group (n=24) of healthy subjects was also recruited. Our results showed that DM1 patients had lower serum Mg concentrations than the control group. It was found that parameters of poor metabolic control and lipid profile are not related to the serum Mg concentration in DM1 patients. However, both the Mg concentration and the PAF-AH activity are independently related to the serum oxLDL concentration. In group 1 the oxLDL concentration and the PAF-AH activity were higher than in group 2, and the control group. Two groups of DM1 patients did not show any differences with regard to the metabolic control. Therefore, the oxidative modification of LDL and the higher activity of PAF-AH are related with the low Mg status; however, no relation has been observed between these parameters and the poor metabolic control in DM1 patients.

The evaluation of IL-12 concentration, PAF-AH, and PLA(2) activity in patients with type 1 diabetes treated with intensive insulin therapy.

OBJECTIVES: The aim of the study was to evaluate the concentration of interleukin 12 (IL-12), the activity of phospholipase A(2) (PLA(2)), and platelet-activating factor acetylhydrolase (PAF-AH) in type 1 diabetes (DM1) patients treated with intensive insulin therapy. DESIGN AND METHODS: Studied parameters were measured in 81 patients, who were subdivided according to the HbA(1)c value, hsCRP concentration, and presence or absence of late complications. RESULTS: PAF-AH activity was higher in the DM1 patients versus the control group (P=0.042). IL-12 concentration was the highest in subgroup with > or =3 mg/L hsCRP (P<0.05). Negative correlations were found for the IL-12 and age of patients and for apo A-I in the subgroup with poor metabolic control. In addition, positive correlation for hsCRP and PAF-AH activity in the subgroup with > or =3 mg/L CRP (P<0.05) was also found. CONCLUSIONS: PAF-AH and IL-12 appear to be implicated in the development of a chronic inflammation in DM1. In addition, our results emphasize a protective role of apo A-I against an increase in IL-12 production.

Increased protein carbonyl groups in the serum of men with chronic arterial occlusion and the effect of postoperative treatment.

BACKGROUND: Critical ischemia leads to the production of reactive oxygen species (ROS) at concentrations exceeding the body's antioxidant capacity, causing inflammation and necrosis in ischemic tissues. The protein CO group content is presently the most general indicator and commonly used marker of protein oxidation. The aim of the present study was to evaluate the concentration of serum CO groups as an effect of protein oxidative damage, and relate it to the activity of ceruloplasmin (Cp). MATERIAL/METHODS: The study group consisted of 12 patients, males 43-73 years of age, with chronic arterial occlusion of the lower limbs (AO). Serum carbonyl groups were measured using reaction with dinitrophenylhydrazine (DNPH), leading to the formation of stable hydrazone products. The oxidase activity of ceruloplasmin in serum was measured according to the spectrophotometric method of Schosinsky by using o-dianisidine dihydrochloride as a substrate. RESULTS: The average value of concentration of CO groups in subjects with AO was found to be significantly higher than in the control group. The changes in the concentration of CO groups during postoperative treatment were negatively and significantly correlated with the value found before surgery. The average oxidase activity of Cp was found to be significantly higher than in the controls. CONCLUSIONS: Prolonged ischemia of the lower limbs of patients with chronic arterial occlusion causes increased concentration of protein CO groups in serum, as the result of the oxidative modification of protein side chains, and in the oxidase activity of Cp, due to acute phase reaction.

Acamprosate involvement in triacylglycerol hydrolysis and transacylation with cholesterol in chronically ethanol-drinking rats.

Acamprosate (AC) is used as a drug for treating alcoholism. We evaluated the effect of AC on serum triacylglycerol hydrolysis (GEH, glycerol ester hydrolysis), triacylglycerol transacylation with cholesterol (GECAT, glycerol ester:cholesterol acyltransferase), and acylcholesterol hydrolysis (Cease, cholesterol ester hydrolysis) in an experimental model of alcoholism. Ethanol-preferring (PRF), non-preferring (NPF), and control (CR) male Wistar rats were treated with AC (500 mg/kg, p.o.) for 21 consecutive days. The beneficial effect of AC on lipid parameters of PRF rats included decreased triacylglycerol, total cholesterol, and LDL-cholesterol, and increased HDL-cholesterol levels. Acamprosate-compensated changes associated with ethanol consumption were observed. Acamprosate treatment decreased GECAT and increased Cease control rats, but increased GECAT and decreased CEase in PRF animals. In all groups of rats, AC treatment did not influence GEH. In conclusion, our results suggest that AC can influence triacylglycerol metabolism by its action on the balance between hydrolysis and transacylation in rats.

Modifications of magnesium and copper concentrations in serum and arterial wall of patients with vascular diseases related to ageing, atherosclerosis and aortic aneurysm.

Relationship between concentration of Mg and Cu in serum and the arterial wall was studied in patients with atherosclerosis obliterans (AO), aortic aneurysm (AA) and in the control group. The effect of ageing was also evaluated. The results showed increased serum concentration of Cu in the eldest control group (50-59 years) when compared to the younger (20-29 years). Serum concentration of Mg was decreased in AO and AA, and that in the arterial wall was lower in AA, than in controls. Concentration of Cu in serum and the arterial wall was higher in AO than in controls. Lower limb ischaemia results in decreased serum Mg and increased Cu in the critical degree as compared with the moderate degree of ischaemia. The ratio Mg/Cu was found lower both in serum and the arterial wall in AO and AA, as a result of ageing and vascular disease, and it could be better marker of ischaemia than individual element concentrations.