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)

Previous studies have shown that renal function in type 2 diabetes correlates better with tubular changes than with glomerular pathology. Since advanced glycation end products (AGEs; AGE-albumin) and in particular carboxymethyllysine (CML) are known to play a central role in diabetic nephropathy, we studied the activation of nuclear factor kappaB (NF-kappaB) in tubular epithelial cells in vivo and in vitro by AGE-albumin and CML. Urine samples from healthy control subjects (n = 50) and type 2 diabetic patients (n = 100) were collected and tested for excretion of CML and the presence of proximal tubular epithelial cells (pTECs). CML excretion was significantly higher in diabetic patients than in healthy control subjects (P < 0.0001) and correlated with the degree of albuminuria (r = 0.7, P < 0.0001), while there was no correlation between CML excretion and HbA(1c) (r = 0.03, P = 0.76). Urine sediments from 20 of 100 patients contained pTECs, evidenced by cytokeratin 18 positivity, while healthy control subjects (n = 50) showed none (P < 0.0001). Activated NF-kappaB could be detected in the nuclear region of excreted pTECs in 8 of 20 patients with pTECs in the urine sediment (40%). Five of eight NF-kappaBp65 antigen-positive cells stained positive for interleukin-6 (IL-6) antigen (62%), while only one of the NF-kappaB-negative cells showed IL-6 positivity. pTECs in the urine sediment correlated positively with albuminuria (r = 0.57, P < 0.0001) and CML excretion (r = 0.55, P < 0.0001). Immunohistochemistry in diabetic rat kidneys and a human diabetic kidney confirmed strong expression of NF-kappaB in tubular cells. To further prove an AGE/CML-induced NF-kappaB activation in pTECs, NF-kappaB activation was studied in cultured human pTECs by electrophoretic mobility shift assays (EMSAs) and Western blot. Stimulation of NF-kappaB binding activity was dose dependent and was one-half maximal at 250 nmol/l AGE-albumin or CML and time dependent at a maximum of activation after 4 days. Functional relevance of the observed NF-kappaB activation was demonstrated in pTECs transfected with a NF-kappaB-driven luciferase reporter plasmid and was associated with an increased release of IL-6 into the supernatant. The AGE- and CML-dependent activation of NF-kappaBp65 and NF-kappaB-dependent IL-6 expression could be inhibited using the soluble form of the receptor for AGEs (RAGE) (soluble RAGE [sRAGE]), RAGE-specific antibody, or the antioxidant thioctic acid. In addition transcriptional activity and IL-6 release from transfected cells could be inhibited by overexpression of the NF-kappaB-specific inhibitor kappaBalpha. The findings that excreted pTECs demonstrate activated NF-kappaB and IL-6 antigen and that AGE-albumin and CML lead to a perpetuated activation of NF-kappaB in vitro infer that a perpetuated increase in proinflammtory gene products, such as IL-6, plays a role in damaging the renal tubule.
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PMID:Activation of tubular epithelial cells in diabetic nephropathy. 1245 11

Oxidative stress is thought to be one of the causative factors contributing to insulin resistance and type 2 diabetes. Previously, we showed that reactive oxygen species (ROS) production is significantly increased in adipocytes from high-fat diet-induced obese and insulin-resistant mice (HF). ROS production was also associated with the increased activity of PKC-delta. In the present studies, we hypothesized that PKC-delta contributes to ROS generation and determined their intracellular source. NADPH oxidase inhibitor diphenyleneiodonium chloride (DPI) reduced ROS levels by 50% in HF adipocytes, and inhibitors of NO synthase (L-NAME, 1 mM), xanthine oxidase (allopurinol, 100 microM), AGE formation (aminoguanidine, 10 microM), or the mitochondrial uncoupler (FCCP, 10 microM) had no effect. Rottlerin, a selective PKC-delta inhibitor, suppressed ROS levels by approximately 50%. However, neither GO-6976 nor LY-333531, effective inhibitors toward conventional PKC or PKC-beta, respectively, significantly altered ROS levels in HF adipocytes. Subsequently, adenoviral-mediated expression of wild-type PKC-delta or its dominant negative mutant (DN-PKC-delta) in HF adipocytes resulted in either a twofold increase in ROS levels or their suppression by 20%, respectively. In addition, both ROS levels and PKC-delta activity were sharply reduced by glucose depletion. Taken together, these results suggest that PKC-delta is responsible for elevated intracellular ROS production in HF adipocytes, and this is mediated by high glucose and NADPH oxidase.
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PMID:PKC-delta-dependent activation of oxidative stress in adipocytes of obese and insulin-resistant mice: role for NADPH oxidase. 1550 33

Insulin resistance accounts for glucotoxicity observed in diabetes and atherosclerotic disease. Glucotoxicity depends from the shift of glucose metabolism from the glycolytic pathway to minor forms of glucose metabolism, including sorbitol, hexosamine and AGE pathways. These pathways increase oxidative stress and/or block insulin signalling so leading to a further decline of insulin action. A genetic defect of insulin action (the g972R Insulin Receptor Substrate 1 variant) may sustain endothelial dysfunction, the first defect of vascular homeostasis in the road to atherosclerosis. Furthermore, hyperglycemia even in the absence of insulin resistance, activates the hexosamine pathway in endothelial cells, affects the production of nitric oxide, increases the production and activity of metalloproteinase 2 and 9 and activates endothelium thus provoking endothelial dysfunction. Oxidative stress and inflammation through activtion of IKK-beta could determine insulin resistance impairing IRS-1 ability to activate the metabolic branch of insulin signalling. Furthermore, increased oxidative stress may be speculated to affect glucose metabolism in a proportion of patients with coronary artery disease. In conclusion, type 2 diabetes and atherosclerosis share vascular homeostasis and glucose metabolism and insulin resistance might be the common road where diabetes and atherosclerosis run together.
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PMID:Review article: diabetes and atherosclerosis--running on a common road. 1622 64

We studied the efficacy of four different treatment regimens (sulphonylurea and metformin+/-acarbose versus glimepiride and rosiglitazone versus glimepiride and bedtime NPH insulin versus multiple actrapid and NPH insulin injections) in poorly controlled type 2 diabetes subjects on hs-CRP, VCAM-1 and AGE at 4, 8 and 12 weeks of treatment. Multiple insulin injections rapidly improved HbA(1c) by 0.6+/-0.9% (p<0.005), 1.2+/-1.3% (p<0.0005) and 1.3+/-1.4% (p<0.0005) at week 4, at week 8 and week 12, respectively. Subjects who continued their existing combination treatment of sulphonylurea, metformin+/-acarbose also showed a significant reduction in HbA(1c) (p<0.05). Although effective in reducing glycemic parameters, there was no reduction in CRP levels in either treatment group. The treatment regimen consisting of rosiglitazone and glimepiride significantly lowered hs-CRP by -2.6 (3.9) mg/L (p<0.05) at week 12 in spite of no improvement in blood glucose. AGE improved in all groups irrespective of type of treatment, glycaemic control and CRP levels. Our data indicate rapid glycaemic control alone does not necessarily result in improvement in markers of inflammation in type 2 diabetes patients.
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PMID:Improvement in C-reactive protein and advanced glycosylation end-products in poorly controlled diabetics is independent of glucose control. 1625 80

ALTHOUGH PEOPLE AGE at different rates, changes to the composition of the human body are a hallmark of aging. As a result of such changes, disease can present differently in a person over 65 years old than it would in a younger adult or child. THIS ARTICLE IDENTIFIES the critical indicators of underlying conditions, including changes in mental status, loss of function, decrease in appetite, dehydration, falls, pain, dizziness, and incontinence. It also describes the presentation of diseases common to older adults, including depression, infection, cardiac disease, gastrointestinal disorders, thyroid disease, and type 2 diabetes.
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PMID:Presentation of illness in older adults. If you think you know what you're looking for, think again. 1654 57

Atherothrombotic complications are frequent in patients with type 2 diabetes. Red blood cells (RBC) from diabetic patients exhibited an increased adhesion which correlated to the extent of vascular complications. In the present study we have investigated the adhesive interactions of RBCs with endothelium, using flow-based assessments. RBCs and endothelial cells were unstimulated or stimulated using respectively adrenaline and TNFalpha. Adhesion assays were carried-out by drawing the RBC suspension through a glass microcapillary tube precoated by human umbilical vein endothelial cells. These microslides were then incorporated into a controlled flow system equipped with a computerized video-microscopic image analysis. RBCs from diabetic patients bind to endothelial cells and could withstand wall shear stresses above 0.1 Pa. After stimulation by TNFalpha the adhesion was 1.5-fold higher. Blocking experiments demonstrated that the adhesion was mediated by the receptor for AGE (RAGE). Adrenaline-treated RBCs showed a transient increase in adhesion at low shear stresses. Inflammatory mediators or catecholamine amplifying diabetic RBC adhesion may aggravate endothelial cell damages.
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PMID:Modulation of RAGE expression influences the adhesion of red blood cells from diabetic patients. 1689 60

The current obesity epidemic throughout the western world has resulted in a considerable increase in the condition Type II diabetes mellitus. Recently, the World Health Organization has predicted that the global prevalence of Type II will increase from 175 million patients in 2003 to over 350 million by 2030. One of the major consequences of this disorder is renal failure, which presents itself as chronic kidney disease, and can progress to end-stage renal disease. Once diagnosed, patients are generally treated using dialysis due to a shortage of kidney donors. The fundamental process of dialysis still requires improvement because the survival rate of these patients is relatively poor. This has resulted in considerable research into improvements in hemodialysis membranes, and the challenge to find more suitable marker(s) in assessing the efficacy of the dialysis process. A class of compounds highlighted as a possible accumulative toxin is advanced glycation end products or AGEs. This is an article regarding the impact of hemodialysis and hemodiafiltration on glucose and AGE levels within the body and the consequences of a chronic hyperglycemic condition. It also highlights the negative aspects of using dextrose in conventional dialysis solutions (an area that has already been identified by peritoneal dialysis clinicians as problematic). The review concludes by suggesting several possible topics of future research.
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PMID:Impact of glucose levels on advanced glycation end products in hemodialysis. 1757 90

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

Type 2 diabetes mellitus, the most prevalent and serious metabolic disease worldwide, is believed to result from the interaction between genetical and lifestyle factors. In genetically predisposed people, the combination of a hypercaloric ingestion and reduced physical activity is responsible for the appearance of insulin resistance. This state can be overcomed, until a certain point, with increments of insulin secretion (hyperinsulinemia). However, an insufficient compensation leads to a state of glucose intolerance, which can evolve to diabetes, according to actual knowledge. The noxious effects of the hyperglycemia, allied with the possible increase of free fatty acids, are mediated by highly reactive molecules, oxygen and nitrogen free radicals species (ROS and RNS). Recent data suggests that these reactive species are signalling molecules and are involved in the regulation of the cellular function, being its increased production or reduced elimination a cause of oxidative stress. Indeed, those free radicals act directly through oxidative damage on macromolecules (proteins, lipids, DNA) or indirectly, activating single transduction pathways sensible to stress mechanisms. In this review, we will consider the pathways recognized as the more significant in stress mechanisms, namely: NF-kB, JNK/SAPK, p38 MAPK, PKC, AGE/RAGE, hexosamines and poliol. These signalling cascades are believed to be responsible for the insulin resistance and reduced insulin secretion, therefore the use of innocuous antioxidant substances such as vitamin C, E and the a-lipoic acid, is seen as a possible step for type 2 diabetic complications management. We will also discuss acetylsalicylic acid potentialities in the above-mentioned pathologies.
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PMID:[Oxidative stress and its effects on insulin resistance and pancreatic beta-cells dysfunction: relationship with type 2 diabetes mellitus complications]. 1867 21

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


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