Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0011860 (type 2 diabetes)
 57,723 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A long-acting (basal) insulin capable of delivering flat, sustained, reproducible glycemic control with once daily administration represents an improvement in the treatment paradigm for both type 1 and type 2 diabetes. Optimization of insulin pharmacodynamics is achievable through structural modification, but often at the expense of alterations in receptor affinity and selectivity. A series of isoelectric point (pI)-shifted insulin analogs based on the human insulin sequence or the GlyA21 acid stable variant were prepared by semi-synthetic methods. The pI shift was achieved through systematic addition of one or more arginine (Arg) or lysine (Lys) residues at the N terminus of the A chain, the N terminus of the B chain, the C terminus of the B chain, or through a combination of additions at two of the three sites. The analogs were evaluated for their affinity for the insulin and IGF-1 receptors, and aqueous solubility under physiological pH conditions. Notably, the presence of positively charged amino acid residues at the N terminus of the A chain was consistently associated with an enhanced insulin to IGF-1 receptor selectivity profile. Increased IGF-1 receptor affinity that results from Arg addition to the C terminus of the B chain was attenuated by cationic extension at the N terminus of the A chain. Analogs 10, 17, and 18 displayed in vitro receptor selectivity similar to that of native insulin and solubility at physiological pH that suggested the potential for extended time action. Accordingly, the in vivo pharmacokinetic and pharmacodynamic profiles of these analogs were established in a somatostatin-induced diabetic dog model. Analog 18 (A0:Arg, A21:Gly, B31:Arg, B32:Arg human insulin) exhibited a pharmacological profile comparable to that of analog 15 (insulin glargine) but with a 4.5-fold more favorable insulin:IGF-1 receptor selectivity. These results demonstrate that the selective combination of positive charge to the N terminus of the A chain and the C terminus of the B chain generates an insulin with sustained pharmacology and a near-native receptor selectivity profile.
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PMID:pI-shifted insulin analogs with extended in vivo time action and favorable receptor selectivity. 1732 92

Endothelial function is considered important in the development of cardiovascular diseases and type 2 diabetes. Circulating advanced glycation end-products (AGEs) and dietary components have been shown to affect endothelial function in type 2 diabetics, but determinants of endothelial function in a non-diabetic population are more poorly investigated. Therefore, we investigated relationships between dietary habits, AGEs and endothelial activation in men with isolated metabolic disturbances. Circulating markers of endothelial activation (soluble forms of vascular cell adhesion molecule-1, intercellular adhesion molecule-1, E-selectin and von Willebrand factor) and plasma N epsilon-carboxymethyl-lysine (CML, the predominant AGE in human plasma) were analyzed in a cross-sectional study of 294 healthy men. Individuals completed a 7-day dietary record, and metabolic and inflammatory parameters were determined. NCEP/ATPIII-criteria were used to define the metabolic syndrome. Endothelial activation was higher in individuals with the metabolic syndrome, and was positively related to certain features of the syndrome (insulin, glucose, inflammation and obesity), but not to others (triacylglycerol and blood pressure). Dietary factors were related to endothelial activation, but CML was not. Multivariate analysis revealed energy and alcohol intake, along with insulin and markers of oxidative stress and inflammation, to be positive predictors of endothelial activation. In this cohort of otherwise healthy men, endothelial activation was increased in individuals with the full metabolic syndrome, but not in those with only some of the components of the metabolic syndrome. Insulin resistance, inflammation, oxidative stress, the dietary intake of energy and alcohol, but not plasma CML, predicted endothelial activation in these men.
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PMID:Markers of endothelial activity are related to components of the metabolic syndrome, but not to circulating concentrations of the advanced glycation end-product N epsilon-carboxymethyl-lysine in healthy Swedish men. 1765 51

Although obesity is a risk factor for development of type 2 diabetes and chemical modification of proteins by advanced glycoxidation and lipoxidation end products is implicated in the development of diabetic complications, little is known about the chemical modification of proteins in adipocytes or adipose tissue. In this study we show that S-(2-succinyl)cysteine (2SC), the product of chemical modification of proteins by the Krebs cycle intermediate, fumarate, is significantly increased during maturation of 3T3-L1 fibroblasts to adipocytes. Fumarate concentration increased > or =5-fold during adipogenesis in medium containing 30 mm glucose, producing a > or =10-fold increase in 2SC-proteins in adipocytes compared with undifferentiated fibroblasts grown in the same high glucose medium. The elevated glucose concentration in the medium during adipocyte maturation correlated with the increase in 2SC, whereas the concentration of the advanced glycoxidation and lipoxidation end products, N(epsilon)-(carboxymethyl)lysine and N(epsilon)-(carboxyethyl)lysine, was unchanged under these conditions. Adipocyte proteins were separated by one- and two-dimensional electrophoresis and approximately 60 2SC-proteins were detected using an anti-2SC polyclonal antibody. Several of the prominent and well resolved proteins were identified by matrix-assisted laser desorption ionization time-of-flight/time-of-flight mass spectrometry. These include cytoskeletal proteins, enzymes, heat shock and chaperone proteins, regulatory proteins, and a fatty acid-binding protein. We propose that the increase in fumarate and 2SC is the result of mitochondrial stress in the adipocyte during adipogenesis and that 2SC may be a useful biomarker of mitochondrial stress in obesity, insulin resistance, and diabetes.
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PMID:Succination of protein thiols during adipocyte maturation: a biomarker of mitochondrial stress. 1772 21

The aim of this study was to examine the effects of biological ageing on concentration of free calcium ions ([Ca(2+)](i)) in platelets of type 2 diabetic patients, an issue not documented till now. Since diabetes platelets are surrounded by a hyperglycemic environment enriched in products of nonenzymatic glycation and oxidation of proteins (known as "advanced glycation end products" (AGEs)), we questioned on the individual effect of high glucose concentration, AGEs, and oxidative stress on platelet [Ca(2+)](i). To these purposes, we performed: (i) measurement of basal and thrombin-stimulated [Ca(2+)](i) in platelets isolated from type 2 diabetic patients and from normal subjects of young (27 +/- 7 years), mature (48 +/- 12 years) and older (>60 years) age, and (ii) quantitation of [Ca(2+)](i) when platelets of young healthy subjects were exposed to 25.5 mM glucose (vs. 11 mM glucose), 0.23-1.7 mM AGE-poly-L-lysine (vs. poly-L-lysine), 0.3-2.26 mM AGE-albumin (vs. albumin), and to 10 mM and 100 mM H(2)O(2). Reactions of nonenzymatic glycation were conducted in vitro to prepare AGE-poly-L-lysine and AGE-albumin, and spectrofluorimetry was used to measure platelet free [Ca(2+)](i) following Fura-2/AM cells loading. The results showed that: (i) in physiological conditions, [Ca(2+)](i) was approximately 10% increased in the platelets of the mature subjects, and approximately 33% enhanced at the older group (vs. young), sustaining that biological ageing is associated with accumulation of free [Ca(2+)](i) within the platelets cytoplasm; (ii) in type 2 diabetes, [Ca(2+)](i) was approximately 16% and approximately 27% higher in the platelets of mature and older patients, respectively (vs. age-matched normals), demonstrating that ageing of diabetics is accompanied by alterations in calcium balance (vs. physiological ageing); (iii) thrombin (1U/ml) induced approximately 39% increase of [Ca(2+)](i) in platelets of matures and approximately 29% at older normals, and approximately 34% increase at the mature diabetics, approximately 84% at the older diabetics (vs. no thrombin condition), indicating that under thrombin stimulation simultaneous insults of diabetes and advanced age produced a higher thrombin-evoked mobilization of Ca(2+) from intracellular stores; (iv) the components of the diabetic milieu had various effects on platelet free [Ca(2+)](i): high enhancement ( approximately 73%) in 25.5 mM glucose (vs. 11 mM glucose), a minor increase ( approximately 15%) in 100 mM H(2)O(2), and a decrease (by approximately 56% and approximately 132%) in 1.7 mM AGE- poly-L-lysine (vs. poly-L-lysine) and 2.26 mM AGE- albumin (vs. albumin), respectively. Thus, a complex of factors contribute to platelet free [Ca(2)(+)](i) during biological ageing of diabetics: age, hyperglycemia and oxidative stress release Ca(2)(+) from intracellular stores, while AGE products reduced the cytosolic free Ca(2+). Thus, platelets [Ca(2)(+)](i) level is the final result of the combined effects of ageing and of the components of the diabetic milieu.
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PMID:Platelet free cytosolic calcium concentration during ageing of type 2 diabetic patients. 1795 64

This study aims to determine the levels of N(epsilon)-(carboxymethyl)lysine (CML) in patients with Type 2 diabetic patients with and without ischemic heart disease (IHD) and to find for a possible association between circulating CML and a number of clinical parameters including lipids, hemoglobin A1c (HbA1c) and malondialdehyde (MDA) in Type 2 diabetic IHD patients. Serum CML levels were measured by enzyme-linked immunosorbent assay using polyclonal anti-CML antibodies. Serum levels of CML and MDA were assessed in 60 IHD patients with Type 2 diabetes, 43 IHD patients without Type 2 diabetes, 64 Type 2 diabetics without IHD, and 80 sex- and age-matched healthy subjects. Correlations studies between CML levels and lipids, HbA1c, and lipid peroxidation were performed in Type 2 diabetes patients with and without IHD. A statistical significance was observed in the levels of serum glucose, lipids (triglyceride, total cholesterol, HDL-cholesterol), MDA, HbA1c, CML and LDL-cholesterol (p<0.05) between the groups of the study. CML levels were significantly increased in diabetic IHD patients compared with Type 2 diabetes patients but without IHD (537.1 +/- 86.1 vs 449.7 +/- 54.9, p<0.001). A positive correlation was observed between serum levels of CML and MDA, r = 0.338 (p = 0.008) in Type 2 diabetes patients with IHD. However, age, HbA1c and lipids had no significant influence on CML levels among diabetics (p>0.05). In conclusion, this study demonstrates the effect of both diabetes and oxidative stress on the higher levels of circulating CML. These results showed that increased serum levels of CML are associated with the development of IHD in Type 2 diabetes mellitus.
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PMID:Role of N-(carboxymethyl)lysine in the development of ischemic heart disease in type 2 diabetes mellitus. 1819 3

Intrauterine growth retardation (IUGR) has been linked to the onset of diseases in adulthood, including type 2 diabetes, and has been proposed to result from altered gene regulation patterns due to epigenetic modifications of developmental genes. To determine whether epigenetic modifications may play a role in the development of adult diabetes following IUGR, we used a rodent model of IUGR that expresses lower levels of Pdx1, a pancreatic and duodenal homeobox 1 transcription factor critical for beta cell function and development, which develops diabetes in adulthood. We found that expression of Pdx1 was permanently reduced in IUGR beta cells and underwent epigenetic modifications throughout development. The fetal IUGR state was characterized by loss of USF-1 binding at the proximal promoter of Pdx1, recruitment of the histone deacetylase 1 (HDAC1) and the corepressor Sin3A, and deacetylation of histones H3 and H4. Following birth, histone 3 lysine 4 (H3K4) was demethylated and histone 3 lysine 9 (H3K9) was methylated. During the neonatal period, these epigenetic changes and the reduction in Pdx1 expression could be reversed by HDAC inhibition. After the onset of diabetes in adulthood, the CpG island in the proximal promoter was methylated, resulting in permanent silencing of the Pdx1 locus. These results provide insight into the development of type 2 diabetes following IUGR and we believe they are the first to describe the ontogeny of chromatin remodeling in vivo from the fetus to the onset of disease in adulthood.
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PMID:Development of type 2 diabetes following intrauterine growth retardation in rats is associated with progressive epigenetic silencing of Pdx1. 1846 33

Insulin resistance and type 2 diabetes are major risk factors for vascular complications. Vascular smooth muscle cells (VSMCs) derived from db/db mice, an established mouse model of type 2 diabetes, displayed enhanced inflammatory gene expression and proatherogenic responses. We examined the hypothesis that aberrant epigenetic chromatin events may the underlying mechanism for this persistent dysfunctional behavior and "memory" of the diabetic cells. Chromatin immunoprecipitation assays showed that levels of histone H3 lysine 4 dimethylation (H3K4me2), a key chromatin mark associated with active gene expression, were significantly elevated at the promoters of the inflammatory genes monocyte chemoattractant protein-1 and interleukin-6 in db/db VSMCs relative to db/+ cells. Tumor necrosis factor-alpha-induced inflammatory gene expression, H3K4me2 levels, and recruitment of RNA polymerase II at the gene promoters were also enhanced in db/db VSMCs, demonstrating the formation of open chromatin poised for transcriptional activation in diabetes. On the other hand, protein levels of lysine-specific demethylase1 (LSD1), which negatively regulates H3K4 methylation and its occupancy at these gene promoters, were significantly reduced in db/db VSMCs. High glucose (25 mmol/L) treatment of human VSMCs also increased inflammatory genes with parallel increases in promoter H3K4me2 levels and reduced LSD1 recruitment. LSD1 gene silencing with small interfering RNAs significantly increased inflammatory gene expression and enhanced VSMC-monocyte binding in nondiabetic VSMCs. In contrast, overexpression of LSD1 in diabetic db/db VSMCs inhibited their enhanced inflammatory gene expression. These results demonstrate novel functional roles for LSD1 and H3K4 methylation in VSMCs and inflammation. Dysregulation of their actions may be a major mechanism for vascular inflammation and metabolic memory associated with diabetic complications.
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PMID:Role of the lysine-specific demethylase 1 in the proinflammatory phenotype of vascular smooth muscle cells of diabetic mice. 1974 69

In comparison to the general population, individuals with diabetes suffer a 3- to 4-fold increased risk for developing complications of atherosclerosis and vascular insufficiency. This fact should be taken into account to develop a suitable determinant for the early detection of these complications and subsequently reduce the adverse effect of type 2 diabetes. In vitro experiments have shown that the products of glucose auto-oxidation and Amadori adducts are both potential sources of N(epsilon)-(carboxymethyl)lysine (CML). Excessive formation of CML on low density lipoprotein (LDL) has been proposed to be an important mechanism for the dyslipidemia and accelerated atherogenesis observed in patients with type 2 diabetes. It has been postulated that the uptake of CML-LDL by LDL receptors is impaired, thereby decreasing its clearance from the blood circulation. Alternatively, the uptake of these modified LDL particles by scavenger receptors on macrophages and vascular smooth muscle cells (SMCs) and by AGE receptors on endothelial cells, SMCs, and monocytes is highly enhanced and this, in turn, is centrally positioned to contribute to the pathogenesis of diabetic vascular complications especially coronary artery disease. The present review summarizes the up-to-date information on effects and mechanism of type 2 diabetes-associated coronary atherosclerosis induced by CML-LDL modification.
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PMID:N(epsilon)-(Carboxymethyl)lysine and Coronary Atherosclerosis-Associated Low Density Lipoprotein Abnormalities in Type 2 Diabetes: Current Status. 1917 84

Histone H3 lysine 9 (H3K9) methylation is a crucial epigenetic mark of heterochromatin formation and transcriptional silencing. Recent studies demonstrated that most covalent histone lysine modifications are reversible and the jumonji C (JmjC)-domain-containing proteins have been shown to possess such demethylase activities. However, there is little information available on the biological roles of histone lysine demethylation in intact animal model systems. JHDM2A (JmjC-domain-containing histone demethylase 2A, also known as JMJD1A) catalyses removal of H3K9 mono- and dimethylation through iron and alpha-ketoglutarate dependent oxidative reactions. Here, we demonstrate that JHDM2a also regulates metabolic genes related to energy homeostasis including anti-adipogenesis, regulation of fat storage, glucose transport and type 2 diabetes. Mice deficient in JHDM2a (JHDM2a-/-) develop adult onset obesity, hypertriglyceridemia, hypercholesterolemia, hyperinsulinemia and hyperleptinemia, which are hallmarks of metabolic syndrome. JHDM2a-/- mice furthermore exhibit fasted induced hypothermia indicating reduced energy expenditure and also have a higher respiratory quotient indicating less fat utilization for energy production. These observations may explain the obesity phenotype in these mice. Thus, H3K9 demethylase JHDM2a is a crucial regulator of genes involved in energy expenditure and fat storage, which suggests it is a previously unrecognized key regulator of obesity and metabolic syndrome.
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PMID:Obesity and metabolic syndrome in histone demethylase JHDM2a-deficient mice. 1962 51

Globally, obesity and diabetes (particularly type 2 diabetes) represents a major challenge to world health. Despite decades of intense research efforts, the genetic basis involved in diabetes pathogenesis & conditions associated with obesity are still poorly understood. Recent advances have led to exciting new developments implicating epigenetics as an important mechanism underpinning diabetes and obesity related disease. One epigenetic mechanism known as the "histone code" describes the idea that specific patterns of post-translational modifications to histones act like a molecular "code" recognised and used by non-histone proteins to regulate specific chromatin functions. One modification which has received significant attention is that of histone acetylation. The enzymes which regulate this modification are described as lysine acetyltransferases or KATs and histone deacetylases or HDACs. Due to their conserved catalytic domain HDACs have been actively targeted as a therapeutic target. Some of the known inhibitors of HDACs (HDACi) have also been shown to act as "chemical chaperones" to alleviate diabetic symptoms. In this review, we discuss the available evidence concerning the roles of HDACs in regulating chaperone function and how this may have implications in the management of diabetes.
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PMID:Histone deacetylase inhibitors target diabetes via chromatin remodeling or as chemical chaperones? 1968 55


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