Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0011849 (diabetes)
 277,896 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Raised levels of plasma vascular endothelial growth factor (VEGF) are found in some cancers, diabetes, and certain other conditions, but levels of its receptor, soluble Flt-1 (sFlt-1), in these diseases have yet to be reported. We hypothesised that smoking would influence levels of these molecules. Consequently, we measured VEGF and sFlt-1 by enzyme-linked immunosorbent assay (ELISA) in plasma from 92 non-smokers and 35 smokers. No difference in VEGF was seen between the groups but, despite considerable overlap, sFlt-1 was significantly lower in smokers (P = 0.027). VEGF and sFlt-1 correlated strongly with each other (P < 0.001). Although VEGF may arise from a number of cell types, including endothelial cells, the primary source of sFlt-1 is thought to be the endothelium; however, neither VEGF nor sFlt-1 correlated with levels of the endothelial cell activation/damage marker soluble thrombomodulin. Our data point to changes in levels of the VEGF receptor, sFlt-1--but not VEGF itself--in smokers, which appears to be unrelated to endothelial cell function.
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PMID:Vascular endothelial growth factor and its receptor, Flt-1, in smokers and non-smokers. 1105 Jul 71

The development of diabetic nephropathy in patients with Type I (insulin-dependent) and Type II (non-insulin-dependent) diabetes mellitus is still a huge clinical problem associated with increased morbidity and mortality. The mechanisms underlying the development of diabetic kidney disease are extremely complex and yet not completely understood. Among many potential pathogenic mechanisms responsible for the development of diabetic kidney disease, various growth factors have been suggested to be important players. In particular, growth hormone (GH)/insulin-like growth factors (IGFs), transforming growth factor beta (TGF-beta), vascular endothelial growth factor (VEGF) and epidermal growth factor (EGF) have measurable effects on the development of experimental diabetic kidney disease through complex intra-renal systems. Recent findings that these growth factors might initiate the early diabetic renal changes have provided insight into processes that might be relevant for future development of new drugs useful in the treatment of diabetic kidney disease. As will appear from the present review, enhanced understanding of the cellular mechanisms responsible for the development of diabetic kidney disease has already allowed the design of specific antagonists of pathophysiologically increased growth factors. Recent studies have shown that treating experimental diabetic models with such antagonists is followed by renoprotection.
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PMID:Putative pathophysiological role of growth factors and cytokines in experimental diabetic kidney disease. 1107 38

Coagulation abnormalities, including an increased platelet turnover, are frequently found in patients with cancer. Because platelets secrete angiogenic factors on activation, this study tested the hypothesis that platelets contribute to angiogenesis. Stimulation with vascular endothelial growth factor (VEGF, 25 ng/mL) of human umbilical vein endothelial cells (HUVECs) promoted adhesion of nonactivated platelets 2.5-fold. In contrast, stimulation of HUVECs with basic fibroblast growth factor (bFGF) did not promote platelet adhesion. By blocking tissue factor (TF) activity, platelet adhesion was prevented and antibodies against fibrin(ogen) and the platelet-specific integrin, alpha(IIb)beta(3), inhibited platelet adhesion for 70% to 90%. These results indicate that VEGF-induced platelet adhesion to endothelial cells is dependent on activation of TF. The involvement of fibrin(ogen) and the alpha(IIb)beta(3) integrin, which exposes a high-affinity binding site for fibrin(ogen) on platelet activation, indicates that these adhering platelets are activated. This was supported by the finding that the activity of thrombin, a product of TF-activated coagulation and a potent platelet activator, was required for platelet adhesion. Finally, platelets at physiologic concentrations stimulated proliferation of HUVECs, indicative of proangiogenic activity in vivo. These results support the hypothesis that platelets contribute to tumor-induced angiogenesis. In addition, they may explain the clinical observation of an increased platelet turnover in cancer patients. Platelets may also play an important role in other angiogenesis-dependent diseases in which VEGF is involved, such as diabetes and autoimmune diseases. (Blood. 2000;96:4216-4221)
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PMID:Vascular endothelial growth factor-stimulated endothelial cells promote adhesion and activation of platelets. 1111 Jun 94

The formation of coronary collateral vessels is a compensatory mechanism secondary to repetitive or chronic myocardial ischemia. During the past three decades the functional and prognostic benefit of such collateral vessels has been established. There are large interindividual differences in the number and extent of collateral vessels that may be explained by differences in the anatomic situation or by differences in the individual capacity to develop functional collateral vessels. Diabetes mellitus has recently been identified as one of the first negative predictors of collateral vessel formation. Novel molecular approaches have helped to improve our understanding of the process of collateral vessel formation in recent years. Besides the process of true angiogenesis, i.e. the formation of new capillaries out of preexisting ones, the formation of a collateral circulation is largely based on the growth of preexisting arterioles (collateral vessels or anastomoses) named arteriogenesis. One important feature of arteriogenesis is the infiltration of monocytes into the growing collateral vessel. Our group shows that the ability of monocytes to migrate towards a gradient of VEGF-A is severely impaired in diabetic individuals, and this impaired response seems to be secondary to a signal transduction defect within the monocyte. In this review the pathophysiology of diabetes-related monocyte dysfunction and the potential role of VEGF-A in collateral vessel formation are discussed.
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PMID:Impaired collateral vessel development in diabetes: potential cellular mechanisms and therapeutic implications. 1116 68

Impaired wound healing is a well-documented phenomenon in experimental and clinical diabetes. Experimental evidence suggests that a defect in vascular endothelial growth factor (VEGF) regulation might be associated with wound-healing disorders. We studied the involvement of lipid peroxidation in the pathogenesis of altered VEGF expression in diabetes-related healing deficit by using an incisional skin-wound model produced on the back of female diabetic C57BL/KsJ db+/ db+ mice and their normal (db+/+m) littermates. Animals were then randomized to the following treatment: raxofelast (15 mg.kg(-1).day(-1) i.p.), an inhibitor of lipid peroxidation, or its vehicle (DMSO/NaCl 0.9%, 1:1 vol: vol). The animals were killed on different days (3, 6, and 12 days after skin injury), and the wounded skin tissues were used for histological evaluation, for analysis of conjugated dienes (CDs), as an index of lipid peroxidation and wound breaking strength. Furthermore, we studied the time course of VEGF mRNA expression throughout the skin-repair process (3, 6, and 12 days after skin injury), by means of reverse transcriptase-polymerase chain reaction, as well as the mature protein in the wounds. Diabetic mice showed impaired wound healing with delayed angiogenesis, low breaking strength, and increased wound CD content when compared with their normal littermates. In healthy control mice, a strong induction of VEGF mRNA was found between day 3 and day 6 after injury, while no significant VEGF mRNA expression was observed at day 12 after injury. In contrast, VEGF mRNA levels, after an initial increase (day 3), were significantly lower in diabetic mice than in normal littermates, and light induction of VEGF mRNA expression was also present at day 12 after injury. Similarly, the wound content of the angiogenic factor was markedly changed in diabetic mice. Administration of raxofelast did not modify the process of wound repair in normal mice, but significantly improved the impaired wound healing in diabetic mice through the stimulation of angiogenesis, re-epithelization, and synthesis and maturation of extracellular matrix. Moreover, raxofelast treatment significantly reduced wound CD levels and increased the breaking strength of the wound. Lastly, the inhibition of lipid peroxidation restored the defect in VEGF expression during the process of skin repair in diabetic mice and normalized the VEGF wound content. The current study provides evidence that lipid peroxidation inhibition restores wound healing to nearly normal levels in experimental diabetes-impaired wounds and normalizes the defect in VEGF regulation associated with diabetes-induced skin-repair disorders.
Diabetes 2001 Mar
PMID:Inhibition of lipid peroxidation restores impaired vascular endothelial growth factor expression and stimulates wound healing and angiogenesis in the genetically diabetic mouse. 1124 89

Systemic hypertension exacerbates diabetic retinopathy and other coexisting ocular disorders through mechanisms that remain largely unknown. Increased vascular permeability and intraocular neovascularization characterize these conditions and are complications primarily mediated by vascular endothelial growth factor (VEGF). Because systemic hypertension increases vascular stretch, we evaluated the expression of VEGF, VEGF-R2 (kinase insert domain-containing receptor [KDR]), and VEGF-R1 (fms-like tyrosine kinase [Flt]) in bovine retinal endothelial cells (BRECs) undergoing clinically relevant cyclic stretch and in spontaneously hypertensive rat (SHR) retina. A single exposure to 20% symmetric static stretch increased KDR mRNA expression 3.9 +/- 1.1-fold after 3 h (P = 0.002), with a gradual return to baseline within 9 h. In contrast, BRECs exposed to cardiac-profile cyclic stretch at 60 cpm continuously accumulated KDR mRNA in a transcriptionally mediated, time-dependent and stretch-magnitude-dependent manner. Exposure to 9% cyclic stretch increased KDR mRNA expression 8.7 +/- 2.9-fold (P = 0.011) after 9 h and KDR protein concentration 1.8 +/- 0.3-fold (P = 0.005) after 12 h. Stretched-induced VEGF responses were similar. Scatchard binding analysis demonstrated a 180 +/- 40% (P = 0.032) increase in high-affinity VEGF receptor number with no change in affinity. Cyclic stretch increased basal thymidine uptake 60 +/- 10% (P < 0.001) and VEGF-stimulated thymidine uptake by 2.6 +/- 0.2-fold (P = 0.005). VEGF-NAb reduced cyclic stretch-induced thymidine uptake by 65%. Stretched-induced KDR expression was not inhibited by AT1 receptor blockade using candesartan. Hypertension increased retinal KDR expression 67 +/- 42% (P < 0.05) in SHR rats compared with normotensive WKY control animals. When hypertension was reduced using captopril or candesartan, retinal KDR expression returned to baseline levels. VEGF reacted similarly, but Flt expression did not change. These data suggest a novel molecular mechanism that would account for the exacerbation of diabetic retinopathy by concomitant hypertension, and may partially explain the principal clinical manifestations of hypertensive retinopathy itself. Furthermore, these data imply that anti-VEGF therapies may prove therapeutically effective for hypertensive retinopathy and/or ameliorating the deleterious effects of coexistent hypertension on VEGF-associated disorders such as diabetic retinopathy.
Diabetes 2001 Feb
PMID:Cyclic stretch and hypertension induce retinal expression of vascular endothelial growth factor and vascular endothelial growth factor receptor-2: potential mechanisms for exacerbation of diabetic retinopathy by hypertension. 1127 59

Major congenital malformations, including those affecting the cardiovascular system, remain the leading cause of mortality and morbidity in infants of diabetic mothers. Interestingly, targeted mutations of several genes (including VEGF and VEGF receptors) and many teratogenic agents (including excess D-glucose) that give rise to embryonic lethal phenotypes during organogenesis are associated with a failure in the formation and/or maintenance of a functional vitelline circulation. Given the similarities in the pathology of the abnormal vitelline circulation in many of these conditions, we hypothesized that the hyperglycemic insult present in diabetes could cause the resultant abnormalities in the vitelline circulation by affecting VEGF/VEGF receptor signaling pathway(s). In this study we report that hyperglycemic insult results in reduced levels of VEGF-A in the conceptus, which in turn, leads to abnormal VEGF receptor signaling, ultimately resulting in embryonic (vitelline) vasculopathy. These findings and our observation that addition of exogenous rVEGF-A(165) within a defined concentration range blunts the hyperglycemia-induced vasculopathy in the conceptus support the concept that VEGF levels can be modulated by glucose levels. In addition, these findings may ultimately lead to novel therapeutic approaches for the treatment of selected congenital cardiovascular abnormalities associated with diabetes.
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PMID:Hyperglycemia-induced vasculopathy in the murine conceptus is mediated via reductions of VEGF-A expression and VEGF receptor activation. 1129 May 33

It has become evident that a closely regulated presence of vascular endothelial growth factor (VEGF) and angiopoietin (Ang) factors determines the fate of blood vessel formation during angiogenesis. As angiogenesis is central to a normal wound-healing process, we investigated the regulation of Ang-1 and -2 and the related tyrosine kinase with immunoglobulin and epidermal growth factor homology (Tie)-1 and -2 receptors during normal repair in Balb/c mice and diabetes-impaired wound healing conditions in genetically diabetic (db/db) mice. For both normal and impaired healing conditions, we observed a constitutive expression of Ang-1, which was paralleled by an increase of Ang-2 upon injury. Whereas the observed Ang-2 expression declines from Day 7 after injury in control mice, diabetic-impaired healing was characterized by still increasing amounts of Ang-2 at these time points. Furthermore, Tie-1 was strongly induced during repair with a prolonged expression in diabetic mice, whereas Tie-2 expression was constitutive during normal repair but completely absent in diabetes-impaired healing. The overexpression of Ang-2 in the presence of markedly reduced VEGF in wounds of diabetic mice was associated with a dramatic decrease in endothelial cell numbers compared with normal healing as assessed by analysis of the endothelium-specific markers CD31 and von Willebrand factor, whereas the lymphatic endothelium remained stable as determined by expression of VEGF receptor-3 (VEGFR-3/Flt-4).
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PMID:Expressional regulation of angiopoietin-1 and -2 and the tie-1 and -2 receptor tyrosine kinases during cutaneous wound healing: a comparative study of normal and impaired repair. 1131 Aug 29

Troglitazone is one of the thiazolidinediones, a new class of oral antidiabetic compounds that are ligands of peroxisome proliferator-activated receptor-gamma. This study on vascular endothelial growth factor (VEGF), also known as vascular permeability factor, was prompted by our clinical observation that the characteristics of troglitazone-induced edema were very similar to those caused by vascular hyperpermeability. When Japanese diabetic patients were screened for plasma VEGF, we found levels to be significantly (P < 0.001) increased in troglitazone-treated subjects (120.1 +/- 135.0 pg/ml, n = 30) compared with those treated with diet alone (29.2 +/- 36.1 pg/ml, n = 10), sulfonylurea (25.8 +/- 22.2 pg/ml, n = 10), or insulin (24.6 +/- 19.0 pg/ml, n = 10). Involvement of troglitazone in increased VEGF levels was further supported by the plasma VEGF levels in five patients before treatment (20.2 +/- 7.0 pg/ml), after 3 months of troglitazone treatment (83.6 +/- 65.9 pg/ml), and 3 months after discontinuation (28.0 +/- 11.6 pg/ml). We further demonstrated that troglitazone, as well as rosiglitazone, at the plasma concentrations observed in patients, increased VEGF mRNA levels in 3T3-L1 adipocytes. VEGF is an angiogenic and mitogenic factor and is currently considered the most likely cause of neovascularization and hyperpermeability in diabetic proliferative retinopathy. Although increased VEGF may be beneficial for subjects with macroangiopathy and troglitazone is currently not available for clinical use, vascular complications, especially diabetic retinopathy, must be followed with great caution in subjects treated with thiazolidinediones.
Diabetes 2001 May
PMID:Troglitazone treatment increases plasma vascular endothelial growth factor in diabetic patients and its mRNA in 3T3-L1 adipocytes. 1133 22

The endothelium-specific antigen PAL-E, associated with transport vesicles in non-barrier endothelium, is almost absent from barrier capillaries in the normal brain and retina. We have recently demonstrated that only leaking retinal capillaries in diabetic retinopathy (DR) in humans characteristically express PAL-E. Here we investigated the relation between the expression of the PAL-E antigen and vascular endothelial growth factor-A (VEGF) in human post-mortem eyes of individuals with diabetes mellitus (DM) and in experimental VEGF-induced retinopathy in cynomolgus monkeys. Cryosections were cut of eyes of 41 individuals with and 30 individuals without DM and eyes of 2 cynomolgus monkeys who received 4 injections of 0.5 microg VEGF in the vitreous of one eye and PBS in the other. The sections were stained with antibodies against VEGF, PAL-E and endogenous markers for microvascular leakage. Specific retinal vascular staining for VEGF was only observed in 10 out of the 41 cases with DM. These 10 cases also had marked uniform PAL-E staining and widespread vascular leakage. In contrast, diabetic patients without microvascular leakage and controls were negative for VEGF and PAL-E. Likewise, PAL-E was found only in the leaky retinal vessels of monkey eyes injected with VEGF. These results indicate that increased expression of the PAL-E antigen in retinal endothelium in conditions with microvascular leakage is related to VEGF and suggest that VEGF directly or indirectly induces PAL-E. PAL-E expression may reflect important endothelial changes involved in the disturbance of the blood-retina barrier in DR.
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PMID:Role of VEGF-A in endothelial phenotypic shift in human diabetic retinopathy and VEGF-A-induced retinopathy in monkeys. 1134 Apr 7


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