Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0033687 (proteinuria)
 24,015 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Semaphorin3a was discovered as a secreted guidance protein that acts as a chemorepellent to migrating axons and endothelial cells. In the adult mouse kidney, it is expressed in podocytes and collecting tubules. Here, we show that exogenous semaphorin3a caused acute nephrotic range proteinuria associated with podocyte foot process effacement and fusion, endothelial cell damage, decreased vascular endothelial growth factor-A receptor expression, and downregulation of the slit-diaphragm proteins podocin, nephrin, and CD2-associated protein. When vascular endothelial growth factor 165 was administered at the same time as Semaphorin3a, no proteinuria or renal ultrastructural abnormalities occurred, suggesting that semaphorin3a effects may be mediated, in part, by downregulation of vascular endothelial growth factor receptor 2 signaling. Our findings indicate that a balance of semaphorin3a to vascular endothelial growth factor-A may be important for glomerular filtration barrier homeostasis.
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PMID:Semaphorin3a disrupts podocyte foot processes causing acute proteinuria. 1807 95

Reduction of vascular endothelial growth factor (VEGF) expression plays a crucial role in chronic kidney disease (CKD). In order to clarify a cause of VEGF suppression in CKD, we examined an interaction between proteinuria and VEGF. Rat proximal tubular cells were subjected to hypoxia with or without albumin to mimic proteinuric conditions, and VEGF expression was assessed by real-time quantitative PCR and enzyme-linked immunosorbent assays. Albumin significantly reduced VEGF expression under hypoxia. Luciferase activity controlled by hypoxia-responsive element (HRE) was suppressed by albumin, demonstrating suppression of the hypoxia-inducible factor (HIF)/HRE pathway. Studies utilizing a proteasome inhibitor and a prolyl hydroxylase inhibitor showed that mechanisms of HIF/HRE pathway suppression by albumin load did not involve degradation of HIF protein levels. Further, albumin did not change HIF mRNA levels. Our data, for the first time, suggest a clear 'link' between proteinuria and hypoxia, the two principal pathogenic factors for CKD progression.
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PMID:Albumin suppresses vascular endothelial growth factor via alteration of hypoxia-inducible factor/hypoxia-responsive element pathway. 1815 59

LDL-apheresis (LA) was originally used for familial hyperlipidemia, and then in Japan extended to use for the treatment of patients with peripheral arterial disease (PAD) and nephrotic syndrome due to steroid-resistant focal glomerular sclerosis (FGS). The reason why this treatment is applicable for these disorders is due to the fact that LA exerts its favorable effects beyond the lipid-lowering effect. The main underlying mechanisms, for example, in the case of LA application in patients with PAD are: (1) improvement of hemorheology, (2) improvement of endothelial dysfunction, (3) elevations of serum levels of NO and bradykinin, (4) increase in serum levels of vascular endothelial growth factor, and (5) reduction of adhesion molecules on monocytes. Furthermore, we have reported that LA could have anti-inflammatory effects because LA reduces serum levels of P-selectin, which is known to play an important role in the development of atherosclerosis as well as a reduction of serum C-reactive protein levels as standard biomarker of atherosclerosis. Massive proteinuria is also an important challenge in nephrology. The possible mechanisms besides removal of toxic lipids are the reduction of the vasoconstrictive prostanoid and thromboxane A2 (TXA2) and an improvement in macrophage function evidenced by a significant amelioration of interleukin-8 production by lipopolysaccharide-stimulated peripheral blood mononuclear cells. It is intriguing to note that in terms of pharmacodynamics, LA improves steroid and cyclosporine uptake into lymphocytes. Although there are no randomized controlled trials, it is clear that LA has various effects beyond lowering lipids. Making the device more concise and changing it into a whole blood adsorption type, we need to collect more clinical cases and to study the underlying mechanisms further.
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PMID:Applications of LDL-apheresis in nephrology. 1817 56

Microalbuminuria is the earliest detectable clinical abnormality in diabetic glomerulopathy. On a molecular level, metabolic pathways activated by hyperglycemia, glycated proteins, hemodynamic factors, and oxidative stress are key players in the genesis of diabetic kidney disease. A variety of growth factors and cytokines are then induced through complex signal transduction pathways. Transforming growth factor-beta 1 (TGF-beta1) has emerged as an important downstream mediator for the development of renal hypertrophy and the accumulation of mesangial extracellular matrix components, but there is limited evidence to support its role in the development of albuminuria. The loss of proteoglycans in the glomerular basement membrane (GBM) has been recently questioned as causative of the albuminuria, and current research has focused on the podocyte as a central target for the effects of the metabolic milieu in the development and progression of diabetic albuminuria. Podocyte-derived vascular endothelial growth factor (VEGF), a permeability and angiogenic factor whose expression is increased in diabetic kidney disease, is perhaps a major mediator of the increased protein filtration. Decreased podocyte number and/or density as a result of apoptosis or detachment, GBM thickening with altered matrix composition, and a reduction in nephrin protein in the slit diaphragm with podocyte foot process effacement, all comprise the principal features of diabetic podocytopathy that clinically manifests as albuminuria and proteinuria. Many of these events are mediated by angiotensin II whose local concentration is stimulated by high glucose, mechanical stretch, and proteinuria itself. Angiotensin II in turn stimulates podocyte-derived VEGF, suppresses nephrin expression, and induces TGF-beta1 leading to podocyte apoptosis and fostering the development of glomerulosclerosis. Proteinuria can then induce in tubular cells a genetic program leading to tubulointerstitial inflammation, fibrosis and tubular atrophy. Besides direct effects of albuminuria on tubular cells, pathophysiological changes in the ultrafiltration barrier lead to an increased tubular filtration of various growth factors (TGF-beta1, insulin-like growth factor I) that may further alter the function of tubular cells. Moreover, angiotensin II also stimulates uptake of ultrafiltered proteins into tubular cells and enhances the production of proinflammatory and profibrotic cytokines within the cells. Migration of macrophages and other inflammatory cells into the tubulointerstitium occurs. Increased synthesis and decreased turnover of extracellular matrix proteins in tubular cells and interstitial fibroblasts contribute to interstitial fibrosis. In addition, under locally high concentrations of angiotensin II and TGF-beta1, tubular cells may change their phenotype and become fibroblasts by a process called epithelial to mesenchymal transition (EMT) which contributes to interstitial fibrosis and tubular atrophy because of vanishing epithelia cells. An alternative explanation for the development of albuminuria in diabetic nephropathy that involves primarily an abnormality in tubular handling of ultrafiltered proteins has also been suggested, but these changes are not necessarily exclusive of the altered properties of glomerular ultrafiltration barrier.
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PMID:Pathogenesis of the podocytopathy and proteinuria in diabetic glomerulopathy. 1822 Jun 94

Despite intense investigation, mechanisms that facilitate the emergence of the pre-eclampsia phenotype in women are still unknown. Placental hypoxia, hypertension, proteinuria and oedema are the principal clinical features of this disease. It is speculated that hypoxia-driven disruption of the angiogenic balance involving vascular endothelial growth factor (VEGF)/placenta-derived growth factor (PLGF) and soluble Fms-like tyrosine kinase-1 (sFLT-1, the soluble form of VEGF receptor 1) might contribute to some of the maternal symptoms of pre-eclampsia. However, pre-eclampsia does not develop in all women with high sFLT-1 or low PLGF levels, and it also occurs in some women with low sFLT-1 and high PLGF levels. Moreover, recent experiments strongly suggest that several soluble factors affecting the vasculature are probably elevated because of placental hypoxia in the pre-eclamptic women, indicating that upstream molecular defect(s) may contribute to pre-eclampsia. Here we show that pregnant mice deficient in catechol-O-methyltransferase (COMT) show a pre-eclampsia-like phenotype resulting from an absence of 2-methoxyoestradiol (2-ME), a natural metabolite of oestradiol that is elevated during the third trimester of normal human pregnancy. 2-ME ameliorates all pre-eclampsia-like features without toxicity in the Comt(-/-) pregnant mice and suppresses placental hypoxia, hypoxia-inducible factor-1alpha expression and sFLT-1 elevation. The levels of COMT and 2-ME are significantly lower in women with severe pre-eclampsia. Our studies identify a genetic mouse model for pre-eclampsia and suggest that 2-ME may have utility as a plasma and urine diagnostic marker for this disease, and may also serve as a therapeutic supplement to prevent or treat this disorder.
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PMID:Deficiency in catechol-O-methyltransferase and 2-methoxyoestradiol is associated with pre-eclampsia. 1846 3

Leptin, one of adipocytokines, plays a wide range of important roles in reproductive biology. We have previously reported that low hypo-adiponectinemia might be involved in the pathophysiology of overweight preeclampsia (PE) patients. Moreover, recent reports have underscored the importance of circulating angiogenic factors in the pathophysiology of PE. Here, we examined whether leptin in conjunction with adiponectin and/or angiogenic factors plays some role in the pathophysiology of PE. We performed a cross-sectional study in 34 PE patients and normal pregnancies matched for gestational age and body mass index as controls. We measured serum concentrations of leptin, adiponectin, the angiogenic factors vascular endothelial growth factor (VEGF), placental growth factor, and the soluble VEGF receptors sFlt-1 and sFlk-1. We observed that leptin levels in PE patients were significantly higher compared with those in controls, but did not observe significant differences between normal- and overweight patients in both groups. We also showed a significant negative correlation between leptin and adiponectin in controls, but not in PE patients. There was a significant correlation between leptin and sFlt-1 in PE patients, while there were significant differences of body mass index, mean blood pressure and proteinuria between high and low leptin/sFlt-1 ratio group in PE patients. Moreover, there was a significant difference of leptin level between IUGR and normal growth group in PE patients. These results suggest that the circulating increased leptin might be derived mainly from the placenta and regulated by the placental hypoxic condition, whereas adiponectin might be derived mainly from adipose tissue; and that leptin might play some role through insulin resistance, autonomic activation, or direct effect on endothelium with other angiogenic factors in pathophysiology of PE compared with the exaggerated release of adiponectin from adipose tissue.
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PMID:Circulating leptin and angiogenic factors in preeclampsia patients. 1849 Aug 35

Bevacizumab, a monoclonal antibody against vascular endothelial growth factor, has shown clinical activity in metastatic colorectal cancer patients when used as either a first-line or second-line treatment. Here, we evaluated the efficacy and safety of bevacizumab plus FOLFIRI (irinotecan, 5-fluorouracil, and leucovorin) or FOLFOX (oxaliplatin, 5-fluorouracil, and leucovorin) in metastatic colorectal cancer cases after failure to FOLFIRI and FOLFOX. Between October 2004 and February 2007, the data on 42 patients with metastatic colorectal cancer after failure of FOLFIRI and FOLFOX were reviewed retrospectively. All patients were treated with bevacizumab plus FOLFIRI or FOLFOX. The median patient age was 57.0 years. The ECOG performance status was 0 or 1 in 27 patients (64.3%). The number of previous chemotherapy regimens was >/=3 in 35 patients (83.3%). Thirty-nine patients were evaluable for response. Four patients had partial responses (PRs) and no patient had a complete response (CR), giving an overall response rate of 9.5%. Twenty-two patients (52.4%) had stable disease and 13 patients (31.0%) showed progressive disease. With a median follow-up time of 12.9 months (range 1.0-30.0 months), the median progression-free survival time and the median overall survival time were 5.3 and 9.5 months, respectively. Grade 3 or 4 neutropenia developed in 18 patients (42.9%), including febrile neutropenia in 4 patients (9.5%). Common non-hematologic toxicities were fatigue (21.4%), neuropathy (21.4%), and mucositis (21.4%). Grade 2 or 3 hypertension occurred in 4 patients (9.6%), and grade 1 or 2 proteinuria was seen in 16 patients (38.1%). The frequencies of adverse events related BV, such as bleeding, thrombosis, and gastrointestinal perforation, were within the ranges of previous reports. However, there were no treatment-related deaths. The combination of bevacizumab plus FOLFIRI or FOLFOX showed modest activity and was relatively tolerable in patients with metastatic colorectal cancer refractory to both FOLFIRI and FOLFOX.
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PMID:Bevacizumab plus FOLFIRI or FOLFOX as third-line or later treatment in patients with metastatic colorectal cancer after failure of 5-fluorouracil, irinotecan, and oxaliplatin: a retrospective analysis. 1849 64

Bevacizumab is the fi rst vascular endothelial growth factor-targeted agent shown to increase survival in patients receiving first- and second-line intravenous 5-FU-based chemotherapy for the treatment of metastatic colorectal cancer. Bevacizumab is typically well tolerated and its major side effects include hypertension, proteinuria, bleeding, gastrointestinal perforation and arterial thrombotic events. Although exfoliative dermatitis has been described as a side effect in 19% of patients, skin rash (type unspecified) has rarely been described in patients following infusion of bevacizumab. We recently reported the fi rst patient with colon cancer manifesting a correlation between rash and a positive drug response with bevacizumab. A 49-year old male with T3 N1 M1 rectal carcinoma received modified FOLFOX-6/bevacizumab, which he tolerated very well except for grade 2 skin rash related to bevacizumab. The rash continued to progress as the serum carcinoembryonic antigen decreased significantly. Computed tomography and positron emission tomography scan confirmed response to FOLFOX/bevacizumab. We therefore believe that this rash was linked to bevacizumab administration and correlated with response to therapy. Grade 1/2 rash has been described in patients after infusion of bevacizumab in initial phase I and II studies. Skin rash was observed in 34% and 46% of patients in the Kabbinavar's study receiving 5 mg/kg dose and 10 mg/kg respectively but no patient developed > grade 3 rash. This toxicity was not well described in pivotal phase III studies. On the other hand, acneiform rash occurs in > 90% patients who receive cetuximab and panitumumab, severity of which appears to be predictive of response. To our knowledge, this case report is the second report of possible correlation between rash and a positive drug response associated with bevacizumab and warrants further investigation of similar observation.
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PMID:Correlation between rash and a positive drug response associated with bevacizumab in a patient with advanced colorectal cancer. 1850 Oct 75

Recently, endothelial dysfunction induced by an uncoupling of vascular endothelial growth factor (VEGF) and nitric oxide has been implicated in the pathogenesis of diabetic nephropathy (DN). Investigating the pathogenesis of DN has been limited, however, because of the lack of animal models that mimic the human disease. In this report, pancreatic beta cell-specific calmodulin-overexpressing transgenic (CaMTg) mice, a potential new model of DN, are characterized with particular emphasis on VEGF and related molecules. CaMTg mice developed hyperglycemia at 3 wk and persistent proteinuria by 3 mo. Morphometric analysis showed considerable increases in the glomerular and mesangial areas with deposition of type IV collagen. Moreover, the pathologic hallmarks of human DN (mesangiolysis, Kimmelstiel-Wilson-like nodular lesions, exudative lesions, and hyalinosis of afferent and efferent arteries with neovascularization) were observed. In addition, increased VEGF expression was associated with an increased number of peritubular capillaries. Expression of endothelial nitric oxidase synthase was reduced and that of VEGF was markedly elevated in CaMTg mice kidney compared with nontransgenic mice. No differences in VEGF receptor-1 or VEGF receptor-2 expression were observed between CaMTg mice and nontransgenic kidneys. In summary, CaMTg mice develop most of the distinguishing lesions of human DN, and the elevated VEGF expression in the setting of diminished endothelial nitric oxide synthase expression may lead to endothelial proliferation and dysfunction. This model may prove useful in the study of the pathogenesis and treatment of DN.
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PMID:Overexpression of calmodulin in pancreatic beta cells induces diabetic nephropathy. 1868 92

Bevacizumab is a humanized monoclonal antibody (mAb) to vascular endothelial growth factor (VEGF), a major proangiogenic factor in advanced solid tumors. Phase I and II trial results suggested that this agent was well tolerated and could be combined with standard regimens in various solid tumors. An initial randomized phase II trial in advanced non-small cell lung cancer (NSCLC) yielded positive results regarding the potential efficacy of this agent in combination with carboplatin and paclitaxel (CbP). It also identified a safety signal in patients with squamous histology, who appear to have a higher rate of serious and potentially life-threatening pulmonary hemorrhage. Because of this observation, patients with predominantly squamous histology were excluded from the pivotal phase III trials, as were patients with brain metastases and a history of significant hemoptysis. Two phase III trials comparing a standard platinum-based doublet with or without bevacizumab have been reported in advanced NSCLC, both of which met their primary endpoints. The trial reported by the Eastern Cooperative Oncology Group (ECOG 4599) was the first to show an overall survival benefit, as well as a benefit in response rates and progression-free survival resulting from the addition of bevacizumab to CbP. Certain toxicities were increased when bevacizumab was added to CbP, including neutropenia, febrile neutropenia, thrombocytopenia, bleeding (including pulmonary hemorrhage), hypertension and proteinuria. Bevacizumab is the first targeted therapeutic agent to improve survival in advanced NSCLC when added to standard chemotherapeutic regimens.
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PMID:Bevacizumab as first-line treatment for advanced non-small cell lung cancer. 1853 87


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