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)

In rat membranous nephropathy, complement C5b-9 induces glomerular epithelial cell (GEC) injury and proteinuria. In cultured rat GEC, C5b-9 stimulates a phosphoinositide-directed phospholipase (PL) C and products of PLC downregulate C5b-9-mediated GEC injury. We now report that C5b-9-induced hydrolysis of phosphatidylcholine (PC) provides an additional source of 1,2-diacylglycerol (DAG). PC was labeled in intact GEC by brief incubation with 1-O-[alkyl-3H]2-lyso-PC. Assembly of C5b-9 stimulated an increase in PC-derived [3H]DAG (173 +/- 18% control), which was reduced in GEC depleted of protein kinase C (PKC) by prolonged preincubation with phorbol 12-myristate 13-acetate (PMA). Similar to C5b-9, [3H]DAG was released from PC after brief incubation of GEC with Ca2+ ionophore A23187 plus PMA. The increases in [3H]DAG induced by C5b-9 and A23187 plus PMA were paralleled by increases in DAG mass. C5b-9 also increased [3H]phosphatidic acid (PA; 182 +/- 37% control), but there was no significant interconversion of DAG and PA. Thus DAG probably originated via PLC. PC-directed PLC activity was also studied in GEC homogenates by release of [14C]DAG from exogenous 1-palmitoyl-2-[arachidonoyl-14C]PC. PLC activity was present at physiological Ca2+ concentration (200-1,200 nM), and PMA stimulated PLC activity in cell homogenates (in presence of ATP). These results demonstrate directly that PMA stimulates release of DAG from PC and are in keeping with the effect of PMA in [3H]lyso-PC-labeled GEC. Thus GEC contain a PC-directed PLC, whose activity is physiologically regulated and is present at nanomolar Ca2+ concentration. C5b-9 stimulates PC-directed PLC, leading to production of DAG. This DAG might trigger a mechanism for limiting injury during complement attack.
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PMID:Phosphatidylcholine-directed phospholipase C: activation by complement C5b-9. 823 84

Nephrotoxicity of free hemoglobin (Hb) based blood substitutes still awaits full elucidation. Previous reports attributed Hb passage through the renal glomeruli to a tendency of the Hb tetramer to dissociate into dimers. Now it has become more evident that the Hb tetramer is able to extravasate. It appears that the electrical charge of proteins plays an important role, with electronegativity and a low isoelectric point favoring intravascular persistence. This effect was utilized in the development of an improved blood substitute, comprising Hb reacted with o-ATP and o-adenosine, to form an intra- and intermolecularly cross linked product, which is reduced with glutathione. The modification reagents possess the desired pharmacologic activities and produce an increase in the electronegative charges on the Hb surface. All Hb polymers and chemically modified tetramers present in this solution have a uniform electronegative charge, with a pl of 6.1-6.2. In this present study, unmodified bovine Hb and an improved blood substitute were used for the replacement of 40% of the total blood volume in rats. The nephrotoxic effect was investigated by the determination of urinary output, glomerular filtration rate (GFR), fractional excretion of sodium (FENa), potassium (FEK), and chloride (FECl), urine/plasma osmolality ratio, and urine N-acetyl-beta-D-glucosaminidase (NAG) level. The free Hb and non heme protein contents in the urine were analyzed by using isoelectric focusing and size exclusion liquid chromatography methods. The results indicate that unmodified Hb is nephrotoxic. An initially elevated urinary output was followed by a significant oliguria associated with decreased GFR, FEK, and FECl and elevated FENa and NAG. Severe hemoglobinuria was associated with proteinuria. Analysis of urine from unmodified Hb treated rats revealed the presence of Hb tetramers. Histopathological examination of the kidneys showed cytoplasmic vacuolization of proximal tubular epithelium. On the contrary, an improved blood substitute did not produce any nephrotoxic reactions. It was found that this Hb solution did not pass through the renal glomerular barrier and was not present in urine samples. In conclusion, such a chemical and pharmacological alteration of Hb molecules reduced their interaction with renal glomeruli and suspended nephrotoxicity.
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PMID:An improved blood substitute. In vivo evaluation of its renal effects. 936 Jan 40

The effect of the potent anticancer drug cisplatin, cis-diamminedichloroplatinum (II) (CDDP), on H+ -ATPase and Na+/H+ exchanger in rat renal brush-border membrane was examined. To measure H+ transport by vacuolar H+ -ATPase in renal brush-border membrane vesicles, we employed a detergent-dilution procedure, which can reorientate the catalytic domain of H+ -ATPase from an inward-facing configuration to outward-facing one. ATP-driven H+ pump activity decreased markedly in brush-border membrane prepared from rats two days after CDDP administration (5 mg/kg, i.p.). In addition, N-ethylmaleimide and bafilomycin A1 (inhibitors of vacuolar H+ -ATPase)-sensitive ATPase activity also decreased in these rats. The decrease in ATP-driven H+ pump activity was observed even at day 7 after the administration of CDDP. Suppression of ATP-driven H+ pump activity was also observed when brush-border membrane vesicles prepared from normal rats were pretreated with CDDP in vitro. In contrast with H+ -ATPase, the activity of Na+/H+ exchanger, which was determined by measuring acridine orange fluorescence quenching, was not affected by the administration of CDDP. These results provide new insights into CDDP-induced renal tubular dysfunctions, especially such as proximal tubular acidosis and proteinuria.
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PMID:Effect of cisplatin on H+ transport by H+ -ATPase and Na+/H+ exchanger in rat renal brush-border membrane. 1095 38

Proton NMR spectroscopy of urine has previously been used to gain insight into the site and mechanism of toxic injury to the kidney. d-Serine injures the rat kidney, causing selective necrosis of the proximal straight tubules. Damage is accompanied by proteinuria, glucosuria, and amino aciduria, the latter preceding the onset of necrosis. This study has employed (1)H NMR spectroscopy of urine and (1)H NMR and (31)P NMR spectroscopy of kidney extracts to examine the nephrotoxic action of d-serine. Urine was collected 0-8 h (all doses) and 8-24, 24-48, 48-72, 72-96, and 96-120 h (500 mg/kg only) postdosing from Alderley Park rats given d-serine (62.5, 125, 250, and 500 mg/kg ip). (1)H NMR spectra were monitored for markers of tubular damage. Additionally, ATP and ADP were quantitated in kidney perchloric acid extracts, prepared after 0.5, 1, 2, 4, and 8 h (500 mg/kg) to assess energy status; serine was also measured in these samples. At 500 mg/kg, glucosuria, amino aciduria, and reduced citrate, alpha-ketoglutarate, and succinate were observed in urine at 0-8 h. Furthermore, serine and pyruvate levels were elevated at this time. After 8-24 h, similar changes were observed; however, they were more severe reflecting the development of the lesion prior to recovery. These perturbations were dose-related, in particular, for serine and pyruvate, with no alterations seen at 62.5 mg/kg. Kidney serine concentration rapidly increased, where it was maximal after 30 min and cleared by 8 h. A decline in ATP, to approximately 60-70% of control, was observed within the kidney at 2-4 h postdosing, when necrosis first becomes evident suggesting that mitochondrial function might be impaired in the early stages of d-serine-induced nephrotoxicity. The use of NMR spectroscopy has given a comprehensive overview of the effects of d-serine in vivo. Information on the excretion of serine and its effect on renal energy metabolism provides insight into the possible mechanism of renal tubule injury.
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PMID:1H NMR pattern recognition and 31P NMR studies with d-Serine in rat urine and kidney, time- and dose-related metabolic effects. 1456 62

Catalytically active antibodies (abzymes) hydrolyzing proteins, polysaccharides, ATP, DNA, and RNA have been detected in the sera of patients with various autoimmune and some viral diseases, but abzymes from the sera of animals are practically unstudied. The development of lupus-like autoimmune disease of MRL/MpJ-lpr mice is an experimental model for study of autoimmune pathologies and immunopathogenesis. In this work, homogeneous IgG preparations were isolated from the sera of MRL/MpJ-lpr mice. These antibodies (Abs), their Fab-fragments, and isolated light chains were shown to possess catalytic activity in DNA hydrolysis, whereas Abs from the sera of control healthy mice did not hydrolyze DNA. The data demonstrate that DNA hydrolyzing activity is an intrinsic property of Abs from MRL/MpJ-lpr mice. It was shown that various markers of autoimmune pathologies (level of total protein concentration in urea (proteinuria), Abs titers to native and denatured DNA, and DNA-hydrolyzing activity of IgG) increased in animals with aging, but they noticeably increased (2-22 times) only after appearance of obvious indicators of pathology independently of age. The highest increase in proteinuria (25-fold), anti-DNA Abs titers (12-19-fold), and abzyme activity (120-fold) was found in mice after their immunization with DNA-protein complex.
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PMID:DNA-hydrolyzing antibodies from sera of autoimmune-prone MRL/MpJ-lpr mice. 1461 78

The effects of the ATP-sensitive potassium (KATP) channel opener YM099, and the angiotensin-converting enzyme (ACE) inhibitor captopril, on the progression of renal disease in rats with surgical renal mass reduction (RMR) were evaluated. Rats were subtotal (5/6) nephrectomized by resection of the renal poles. After 2 weeks of RMR, rats were randomized to three groups and treated for 6 weeks: no treatment (n=9); YM099 at a dose of 0.3 mg/kg by daily oral administration (n=9); or captopril at a dose of 50 mg/kg by daily oral administration (n=9). Sham-operated rats were used as normal animals (n=9). In RMR rats with no treatment, proteinuria progressively developed. At 8 weeks after RMR, renal function as assessed by plasma creatinine (Pcr) and blood urea nitrogen (BUN) was impaired. Pharmacological activation of KATP channel opening by YM099 showed no beneficial effect on proteinuria and renal functional parameters. On the other hand, pharmacological ACE inhibition by captopril significantly attenuated proteinuria, and tended to inhibit the increases in Pcr and BUN; however, these effects were not statistically significant. The presents study indicates that YM099 exhibits no renoprotection with antiproteinuric effect in rats with progressive renal disease. These findings suggest that activation of KATP channel opening may play no role in the retardation of progressive renal disease.
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PMID:Comparison between YM099 and captopril in rats with renal mass reduction-induced progressive renal disease. 1568 2

We assessed the prevalence of chronic kidney disease (CKD) in a hospital-based screening program in Okinawa, Japan. The significance of metabolic syndrome as a determinant of CKD was examined using multivariate logistic regression analysis. A total of 6980 participants, aged 30-79 years, participated in a screening program in Tomishiro Chuo Hospital. Metabolic syndrome was defined according to the criteria of the Adult Treatment Panel III (ATP III). Data were also analyzed according to the modified criteria of the National Cholesterol Education Program (NCEP) that defines abdominal obesity as a waist circumference of > oe =85 cm in men and > or =90 cm in women. CKD was defined as dipstick proteinuria (> or =1+) or a reduced glomerular filtration rate (GFR). GFR was estimated using the abbreviated Modification of Diet in Renal Disease (MDRD) formula. The prevalence of metabolic syndrome and CKD was 12.8 and 13.7%, respectively. Metabolic syndrome was a significant determinant of CKD (adjusted odds ratio (OR) 1.537 and 95% confidence interval (CI) 1.277-1.850, P<0.0001). The adjusted OR (95% CI) was 1.770 (1.215-2.579, P=0.0029) for those with four metabolic syndrome risk factors compared to those with no metabolic syndrome risk factors. Metabolic syndrome was a significant determinant for younger participants (<60 years; OR 1.686, 95% CI 1.348-2.107, P<0.0001), but not for older participants (> or =60 years; OR 1.254, 95% CI 0.906-1.735, NS). The relationship between the number of metabolic syndrome risk factors and the prevalence of CKD was linear using the modified criteria. The results suggest that metabolic syndrome is a significant determinant of CKD in men under 60 years of age, in Okinawa, Japan.
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PMID:Metabolic syndrome and chronic kidney disease in Okinawa, Japan. 1640 28

Hyperglycemia-induced overproduction of mitochondrial reactive oxygen species has emerged as a major player in diabetic vascular complications. Mammalian translocase of inner mitochondrial membrane 44 (TIM44) was identified by upregulation in diabetic mouse kidneys. TIM44 functions as a membrane anchor of mitochondrial heat-shock protein 70 (mtHsp70) to TIM23 complex and is involved in the import of mitochondria-targeted preproteins into mitochondrial matrix. The process is dependent on inner membrane potential and ATP hydrolysis on ATPase domain of mitochondrial heat-shock protein 70. Hemagglutination virus of Japan-envelope vector that carries pcDNA3.1 plasmid that contains the full-length cDNA of TIM44 and control plasmid were injected weekly into the tail vein of uninephrectomized streptozotocin-induced diabetic CD-1 mice. The gene delivery alleviated proteinuria and renal hypertrophy at 8 wk after the injection, inhibited renal cell proliferation and apoptosis, and suppressed superoxide production. In vitro experiments, using human proximal tubular (HK2) cells, revealed that the gene delivery of TIM44 reversed high glucose-induced metabolic and cellular abnormalities such as enhanced reactive oxygen species production, increased ATP contents, alterations in inner membrane potential, increased cell proliferation, and apoptosis. Transfection with siRNA and expressing vector of TIM44 revealed that TIM44 facilitates import of antioxidative enzymes such as superoxide dismutase and glutathione peroxidase into mitochondria. The gene delivery of TIM44 therefore seems to be beneficial for the maintenance of mitochondrial function and is a novel therapeutic approach for diabetic nephropathy.
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PMID:Therapeutic approach for diabetic nephropathy using gene delivery of translocase of inner mitochondrial membrane 44 by reducing mitochondrial superoxide production. 1651 Jul 62

Mutations in ClC-5 (chloride channel 5), a member of the ClC family of chloride ion channels and antiporters, have been linked to Dent's disease, a renal disease associated with proteinuria. Several of the disease-causing mutations are premature stop mutations which lead to truncation of the C-terminus, pointing to the functional significance of this region. The C-terminus of ClC-5, like that of other eukaryotic ClC proteins, is cytoplasmic and contains a pair of CBS (cystathionine beta-synthase) domains connected by an intervening sequence. The presence of CBS domains implies a regulatory role for nucleotide interaction based on studies of other unrelated proteins bearing these domains [Ignoul and Eggermont (2005) Am. J. Physiol. Cell Physiol. 289, C1369-C1378; Scott, Hawley, Green, Anis, Stewart, Scullion, Norman and Hardie (2004) J. Clin. Invest. 113, 274-284]. However, to date, there has been no direct biochemical or biophysical evidence to support nucleotide interaction with ClC-5. In the present study, we have expressed and purified milligram quantities of the isolated C-terminus of ClC-5 (CIC-5 Ct). CD studies show that the protein is compact, with predominantly alpha-helical structure. We determined, using radiolabelled ATP, that this nucleotide binds the folded protein with low affinity, in the millimolar range, and that this interaction can be competed with 1 muM AMP. CD studies show that binding of these nucleotides causes no significant change in secondary structure, consistent with a model wherein these nucleotides bind to a preformed site. However, both nucleotides induce an increase in thermal stability of ClC-5 Ct, supporting the suggestion that both nucleotides interact with and modify the biophysical properties of this protein.
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PMID:Nucleotides bind to the C-terminus of ClC-5. 1668 97

Mercury, cadmium, and other heavy metals have a high affinity for sulfhydryl (-SH) groups, inactivating numerous enzymatic reactions, amino acids, and sulfur-containing antioxidants (NAC, ALA, GSH), with subsequent decreased oxidant defense and increased oxidative stress. Both bind to metallothionein and substitute for zinc, copper, and other trace metals reducing the effectiveness of metalloenzymes. Mercury induces mitochondrial dysfunction with reduction in ATP, depletion of glutathione, and increased lipid peroxidation; increased oxidative stress is common. Selenium antagonizes mercury toxicity. The overall vascular effects of mercury include oxidative stress, inflammation, thrombosis, vascular smooth muscle dysfunction, endothelial dysfunction, dyslipidemia, immune dysfunction, and mitochondrial dysfunction. The clinical consequences of mercury toxicity include hypertension, CHD, MI, increased carotid IMT and obstruction, CVA, generalized atherosclerosis, and renal dysfunction with proteinuria. Pathological, biochemical, and functional medicine correlations are significant and logical. Mercury diminishes the protective effect of fish and omega-3 fatty acids. Mercury, cadmium, and other heavy metals inactivate COMT, which increases serum and urinary epinephrine, norepinephrine, and dopamine. This effect will increase blood pressure and may be a clinical clue to heavy metal toxicity. Cadmium concentrates in the kidney, particularly inducing proteinuria and renal dysfunction; it is associated with hypertension, but less so with CHD. Renal cadmium reduces CYP4A11 and PPARs, which may be related to hypertension, sodium retention, glucose intolerance, dyslipidemia, and zinc deficiency. Dietary calcium may mitigate some of the toxicity of cadmium. Heavy metal toxicity, especially mercury and cadmium, should be evaluated in any patient with hypertension, CHD, or other vascular disease. Specific testing for acute and chronic toxicity and total body burden using hair, toenail, urine, serum, etc. with baseline and provoked evaluation should be done.
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PMID:The role of mercury and cadmium heavy metals in vascular disease, hypertension, coronary heart disease, and myocardial infarction. 1740 90


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