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)

We investigated whether different concentrations of elevated glucose - corresponding to levels observed in patients with type 2 diabetes under routine care (post-prandial mean and maximum values) and those used for diagnosing diabetes - induce impairment of vascular reactivity of the macro- and microcirculation in non-diabetic rabbits. Aortic rings and isolated perfused kidneys from normal rabbits were acutely exposed (3 h) to normal (5.5 mm) or high (7-25 mM) D-glucose concentrations. Vascular reactivity was evaluated with endothelium-dependent [acetylcholine (ACh) and bradykinin (BK)] and independent [sodium nitroprusside (SNP)] vasodilating agents. Endothelium-dependent relaxation of the thoracic aorta induced by ACh or BK was significantly attenuated after a 3-h exposure to high D-glucose (15-25 mM) but not after corresponding increased osmolarity with mannitol solutions. Relaxation induced by SNP (endothelium-independent) was not affected by high D-glucose concentrations. Moreover, endothelium-dependent but not independent vasodilation of the isolated rabbit kidney was also impaired after 3-h perfusion with high D-glucose (11.1-25 mM). Perfusion with mannitol solutions (15-25 mM) partially blunted endothelium-dependent renal vasodilation. It is concluded that acute hyperglycemia corresponding to post-prandial levels in patients with type 2 diabetes induces endothelial dysfunction of conduit vessels as well as of the renal circulation of non-diabetic rabbits.
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PMID:Glucose levels observed in daily clinical practice induce endothelial dysfunction in the rabbit macro- and microcirculation. 1514 86

The therapeutic use of angiotensin converting enzyme (ACE) inhibitors, at a large scale, in arterial hypertension has showed that these molecules can exert beneficial effects on insulin sensitivity and may reduce the occurrence of type 2 diabetes mellitus. One hypothesis explaining these effects of ACE inhibitors may relate to their capacity to interfere with bradykinin (BK) metabolism and action. BK may participate in the regulation of substrate utilization by several tissues by improving blood flow and substrate delivery to the tissues and also by promoting translocation of glucose transporters. Moreover, BK has been shown to increase phosphorylation of insulin receptor and its cell substrates. BK also appears to improve the release of insulin. Furthermore, insulin may activate the kallikrein-kinin system, which consequently may increase its metabolic effects. However, in experimental diabetes mellitus, BK can participate to the inflammatory reaction leading to Langerhans islets destruction. In diabetes, whereas tissue kallikrein mRNA levels were reduced in several organs, an overexpression of kinin receptors, an increase in plasma levels of kininogens and kallikrein and an activation of the kinin system have all been reported. Lastly, kinins may be involved in the development of diabetic nephropathy. Reduction of kinin metabolism by ACE inhibitors might be involved in the beneficial effects exerted by these compounds in diabetic kidney functions.
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PMID:The kallikrein-kinin system, angiotensin converting enzyme inhibitors and insulin sensitivity. 1525 31

The inhibition of the renin-angiotensin system (RAS) with either angiotensin converting enzyme inhibitors (ACEIs) or AT1 angiotensin receptor blockers (ARBs) consistently and significantly reduces the incidence of type 2 diabetes in patients with hypertension or congestive heart failure. The mechanisms underlying this protective effect appear to be complex and may involve an improvement of both insulin sensitivity and insulin secretion. These two effects may result, at least in part, from the well known effects of these pharmacological agents on the vascular system on the one hand, on the ionic balance on the other hand. Indeed, the vasodilation induced by ACEIs or ARBs could improve the blood circulation in skeletal muscles, thus favouring peripheral insulin action, but also in the pancreas, thus promoting insulin secretion. Preserving cellular potassium and magnesium pools by blocking the aldosterone effects could also improve both cellular insulin action and insulin secretion. However, besides these classical effects, new mechanisms have been recently suggested. A direct effect of the inhibition of angiotensin and/or of the enhancement of bradykinin on various steps of the insulin cascade signalling has been described as well an increase in GLUT4 glucose transporters after RAS inhibition. Furthermore, it has been demonstrated that angiotensin II inhibits adipogenic differentiation of human adipocytes via A1 receptors and, therefore, it has been hypothesised that RAS blockade may prevent diabetes by promoting the recruitment and differentiation of adipocytes. Finally, some lipophilic ARBs appear to induce PPAR-gamma activity in the adipose tissue. Hence, the protection against type 2 diabetes observed after RAS inhibition may be partially linked to a thiazolidinedione-like effect. In conclusion, numerous physiological and biochemical mechanisms could explain the protective effect of RAS inhibition against the development of type 2 diabetes in individuals with arterial hypertension or congestive heart failure. What might be the main mechanism in the overall protection effect of ACEIs or ARBs remains an open question.
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PMID:Renin-angiotensin system inhibition prevents type 2 diabetes mellitus. Part 2. Overview of physiological and biochemical mechanisms. 1567 19

Hypertension and proteinuria are risk factors for renal disease progression. There is clear evidence that pharmacological blockade of the RAS with angiotensin converting enzyme inhibitors (ACEI) or angiotensin receptor blockers (ARB) reduces proteinuria and slows down the progression of renal disease in diabetic and non diabetic nephropathies, a beneficial effect not related to blood pressure control. However, not all patients respond similarly to these treatments. Some patients exhibit a significant beneficial response while others do not. The absence of response may be explained by the incomplete blockade of the RAS obtained with ACEI, which are unable to block completely the formation of AII, some generation of AII is produced via other non ACE pathways. In the search of new alternatives that could improve the antiproteinuric and nephroprotective effects of RAS blockers, the association of ACEI and ARB might prove to be useful. ARB produces a complete blockade of the RAS and stimulates the vasodilating and non-proliferative actions of AII via the AT-2 receptor. Furthermore, ACE inhibitors but not ARB; inhibit the metabolism of kinins, which increases the level of bradykinin, a potent vasodilator. Recently, several authors have shown a more marked antiproteinuric effect of the dual blockade of the RAS versus ACEI or ARB alone in spite of a similar effect on blood pressure. A recent study also has demonstrated that this more marked antiproteinuric effect is associated with a less progression of renal disease in primary, non diabetic nephropathies. Furthermore, at least two studies have shown that, treatment with ARB postpones end-stage renal disease and reduces the rate of decline in renal function in patients with type 2 diabetes and nephropathy, but until now, there is not any clear evidence of a superior beneficial effect of dual blockade versus maximal recommended dose of ARB regarding renal progression in type 2 diabetic nephropathy, which is the most frequent cause of end stage renal disease. Long-term clinical trials are needed and encouraged to further establish the significant role of dual blockade in renal protection particularly in diabetic nephropathy.
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PMID:The reno-protective effect of the dual blockade of the renin angiotensin system (RAS). 1585 85

One of the most replicated loci influencing type 2 diabetes-related quantitative traits (quantitative trait loci [QTL]) is on chromosome 3q27 and modulates both type 2 diabetes-and metabolic syndrome-associated phenotypes. A QTL for type 2 diabetes age of onset (logarithm of odds [LOD] score = 3.01 at D3S3686, P = 0.0001) was identified in a set of French families. To assess genetic variation underlying both age-of-onset QTL and our previous type 2 diabetes linkage in a 3.87-Mb interval, we explored 36 single nucleotide polymorphisms (SNPs) in two biologically relevant candidate genes for glucose homeostasis, kininogen (KNG1), and eukaryotic translation initiation factor 4alpha2 (EIF4A2). Analysis of 148 families showed significant association of a frequent SNP, rs266714, located 2.47 kb upstream of EIF4A2, with familial type 2 diabetes (family-based association test, P = 0.0008) and early age of onset (P = 0.0008). This SNP also contributes to both age-of-onset QTL (1.13 LOD score decrease P = 0.02) and type 2 diabetes linkage (genotype identical-by-descent sharing test, P = 0.02). However, no association was observed in three independent European diabetic cohorts. EIF4A2 controls specific mRNA translation and protein synthesis rate in pancreatic beta-cells, and our data indicates that EIF4A2 is downregulated by high glucose in rat beta-INS832/13 cells. The potential role of EIF4A2 in glucose homeostasis and its putative contribution to type 2 diabetes in the presence of metabolic stress will require further investigation.
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PMID:EIF4A2 is a positional candidate gene at the 3q27 locus linked to type 2 diabetes in French families. 1656 44

CGS 35601 (L-tryptophan, N-[[1-[[(2S)-2-mercapto-4-methyl-1-oxopentyl]amino]-cyclopentyl]carbonyl]) is one of a few single molecules capable of inhibiting the activities of angiotensin-converting enzyme (ACE), neutral endopeptidase (NEP) and endothelin converting enzyme (ECE) simultaneously, with IC(50) values of 22, 2, and 55 nM, respectively. Through the inhibition of ACE and ECE, it blocks the conversion of angiotensin I (AI) and big endothelin-1 (big ET-1) into the two most potent peptidic vasoconstrictors, angiotensin II (AII) and ET-1, respectively. By inhibiting NEP, CGS 35601 also prevents the degradation of peptidic vasodilators such as bradykinin (BK), natriuretic peptides (NPs) and adrenomedullin (ADM) and, hence, modulates the secondary release of other vasoactive mediators such as nitric oxide (NO) and prostaglandins. In chronic (30 days) experiments, CGS 35601 is well tolerated with a very good safety profile in healthy normotensive, hypertensive and type 2 diabetic rats. The antihypertensive efficacy of CGS 35601 was demonstrated in chronically instrumented, unrestrained and conscious rat models of hypertension (SHR and DSS) and type 2 diabetes (ZDF-fatty). It lowered blood pressure effectively as well as modulated plasma concentrations of a number of circulating vasoactive peptidic mediators that are keys to the regulation of the vascular tone. These data suggest that CGS 35601, a triple vasopeptidase inhibitor (VPI), may represent a novel class of antihypertensive drugs and may have the potential to reduce morbidity and mortality from cardiovascular disorders, diabetes and subsequent renal complications. Similar in vivo ACE, NEP, and ECE inhibitory activities were also observed with the orally active prodrug, CGS 37808 (L-tryptophan, N-[[1-[[(2S)-2-(acetylthio)-4-methyl-1-oxopentyl]amino]cyclopentyl]-carbonyl]-, methyl ester.
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PMID:CGS 35601, a triple inhibitor of angiotensin converting enzyme, neutral endopeptidase and endothelin converting enzyme. 1661 31

Adiponectin is a fat cell-secreted hormone with antidiabetic and anti-inflammatory activities. The reduced adiponectin levels are associated with obesity-related metabolic syndrome. Replenishment of this hormone into animal models can improve insulin sensitivity, decrease blood glucose and lipid levels, and prevent the development of atherosclerosis and fatty liver injury. Despite these findings, the underlying molecular mechanisms remain largely unknown. Here, we have used affinity chromatography to purify the protein complexes that are associated with adiponectin in human serum. The nature of these adiponectin-binding proteins was analyzed by MS/MS. Eight proteins from the adiponectin-containing protein mixtures have been identified. Many of them, including thrombospondin-1 (TSP-1), histidine-rich glycoprotein, kininogen 1, and alpha 2 macroglobulin (alpha2M), are well-known glycoproteins involved in the regulation of inflammation, angiogenesis, and tissue remodeling. Coimmunoprecipitation and radioligand competitive-binding assays confirmed the direct interactions between adiponectin and alpha2M, or TSP-1. Moreover, these specific bindings were also detected in the serum samples derived from both healthy human subjects and patients with type 2 diabetes. In summary, our study demonstrated that, in the circulation, adiponectin forms protein complexes with other serum proteins. These proteins might serve as the physiological-binding partners of adiponectin and regulate its bioavailability and biological activities.
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PMID:Proteomic characterization of human serum proteins associated with the fat-derived hormone adiponectin. 1676 90

Maternal malnutrition is known to impair fetal growth and predispose to the development of hypertension and type 2 diabetes. Recently, studies have demonstrated that intrauterine malnutrition is followed later in male offspring by oxidative stress characterized by increased superoxide generation due to activation of NADPH oxidase and reduced antioxidant defenses. However, few studies have investigated the mechanisms involved in endothelial dysfunction in female offspring. We evaluated the effects of the exogenous application of superoxide scavengers on the endothelium-dependent vasorelaxation in the mesenteric microvessels of female offspring. In addition, we examined indicative parameters of oxidative stress by measuring superoxide anion concentration and the activity of superoxide dismutase (SOD) as a marker of antioxidant defenses. Pregnant female Wistar rats were fed either a normal diet or 50% of this, throughout gestation. Intrauterine malnutrition induced hypertension and increased superoxide production without affecting SOD activity. Topical application of MnTMPyP (SOD mimetic) and apocynin (NADPH oxidase inhibitor) significantly improved the altered arteriolar responses to acetylcholine and bradykinin. In addition, incubation with apocynin reduced superoxide generation in these female offspring. The data suggest that after exposure to intrauterine malnutrition, female offspring present an increased superoxide production that is, at least in part, responsible for an endothelial dysfunction observed in these animals. These effects may be mediated via modulation of enzyme systems that generate superoxide.
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PMID:Long-term effects of intrauterine malnutrition on vascular function in female offspring: implications of oxidative stress. 1715 80

Neutral endopeptidase (NEP) is the major enzyme involved in the metabolic inactivation of a number of bioactive peptides including the enkephalins, substance P, endothelin, bradykinin and atrial natriuretic factor, as well as the incretin hormone glucagon-like peptide 1 (GLP-1), which is a potent stimulator of insulin secretion. The activity of GLP-1 is also rapidly abolished by the serine protease dipeptidyl peptidase IV (DPP-IV), which led to an elevated interest in inhibitors of this enzyme for the treatment of type II diabetes. A dual NEP/DPP-IV inhibitor concept is proposed, offering an alternative strategy for the treatment of type 2 diabetes. Here, the synthesis and crystal structures of the soluble extracellular domain of human NEP (residues 52-749) complexed with the NEP, competitive and potent dual NEP/DPP-IV inhibitor MCB3937 are described.
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PMID:Structural studies of a bifunctional inhibitor of neprilysin and DPP-IV. 1770 66

Essential hypertension is an insulin resistant state. Early insulin signaling steps are impaired in essential hypertension and a large body of data suggests that there is a crosstalk at multiple levels between the signal transduction pathways that mediate insulin and angiotensin II actions. At the extracellular level the angiotensin converting enzyme (ACE) regulates the synthesis of angiotensin II and bradykinin that is a powerful vasodilator. At early intracellular level angiotensin II acts on JAK-2/IRS1-IRS2/PI3-kinase, JNK and ERK to phosphorylate serine residues of key elements of insulin signaling pathway therefore inhibiting signaling by the insulin receptor. On another level angiotensin II inhibits the insulin signaling inducing the regulatory protein SOCS 3. Angiotensin II acting through the AT1 receptor can inhibit insulin-induced nitric oxide (NO) production by activating ERK 1/2 and JNK and enhances the activity of NADPH oxidase that leads to an increased reactive oxygen species generation. From the clinical standpoint, the inhibition of the renin angiotensin system improves insulin sensitivity and decreases the incidence of Type 2 Diabetes Mellitus (T2DM). This might represent an alternative approach to prevent type 2 diabetes in patients with hypertension and metabolic syndrome, (i.e. insulin resistant patients). This review will discuss: a) the molecular mechanisms of the crosstalk between the insulin and angiotensin II signaling systems b) the results of clinical studies employing drugs targeting the renin-angiotensin II-aldosterone systems and their role in glucose metabolism and diabetes prevention.
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PMID:The crosstalk between insulin and renin-angiotensin-aldosterone signaling systems and its effect on glucose metabolism and diabetes prevention. 1885 18


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