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)

Insulin-like growth factor I (IGF-I) is present in serum in association with specific IGF-binding proteins (IGFBPs) primarily in a large (approximately 150K) ternary or a smaller (approximately 50K) binary protein complex or in the free form (< or = 1%). We hypothesized that glomerular proteinuria results in urinary excretion of IGF-I/IGF-binding protein complexes and that the nephrotic syndrome induces abnormal serum distribution and liver synthesis of IGF-binding proteins. In nephrotic rats, serum IGF-I levels are reduced compared with pair-fed control animals. In nephrotic rat serum, binding to IGFBP-3 is reduced and Western immune analysis demonstrates an approximately 27K fragment that does not bind IGF-I, suggesting in vivo proteolysis of IGFBP-3. In contrast, binding and serum levels of IGFBP-2 are increased in nephrotic rats, which results from increased synthesis in the liver. In Nagase analbuminemic rats, the IGF-I levels and IGFBP-distribution in serum are normal suggesting that the reduced albumin levels in the nephrotic syndrome do not cause the increased liver synthesis and serum levels of IGFBP-2. Nephrotic rat urine contains IGFBP-3 and IGFBP-2 as well as strong activity of an IGFBP-3 protease. Because the 150K ternary complex in serum but not the smaller binding protein complex is restricted to the intravascular space, the shift of binding from IGFBP-3 (ternary complex) to IGFBP-2 (binary complex) in nephrotic rat serum may help to maintain tissue availability despite the reduction in serum IGF-I levels.
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PMID:Insulin-like growth factor I and its binding proteins in the experimental nephrotic syndrome. 753 4

Growth failure appears to be a major problem for nephrotic children who fail to respond to steroid therapy. Recently altered serum insulin-like growth factor (IGF) and IGF-binding protein (IGFBP) profiles are reported in renal failure and glomerulonephritis. In this study, the serum IGFBP profile was evaluated by Western ligand blot and RIA in 22 patients with the nephrotic syndrome. Serum IGFBP-3 was decreased, whereas IGFBP-2 was increased in most patients with the nephrotic syndrome. The mean serum IGFBP-3 level was 2123 +/- 531 ng/mL in active states and was increased to a normal level (3593 +/- 407 ng/mL) in remission states. We also measured serum IGF-I by RIA. The serum concentration of IGF-I (mean +/- SD) was 67.4 +/- 23.2 ng/mL in active states and was increased to 127.1 +/- 21.8 ng/mL in remission states, but was still lower than that in control subjects (180.4 +/- 15.8 ng/mL). IGF-I and IGFBP-3 levels were not correlated with primary renal diseases or the amount of proteinuria. For serum IGF-IGFBP complexes, 150-kDa complexes were significantly decreased in patients with the nephrotic syndrome compared with those in control subjects. In urine from nephrotic syndrome patients, 150- and 50-kDa complexes were found, whereas these complexes did not exist in the urine of control subjects. We speculate that low serum IGF-I and IGFBP-3 levels would be partially due to the increased urinary losses of serum IGF-IGFBP complexes, especially that of 150 kDa, and these changes may contribute to growth failure in persistent nephrotic syndrome.
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PMID:Insulin-like growth factor-I (IGF-I) and IGF-binding proteins in children with nephrotic syndrome. 862 47

Indirect biomarkers of recombinant human growth hormone (rhGH), insulin-like growth factor-I (IGF-I), insulin-like growth factor-II (IGF-II), insulin-like growth factor binding proteins (IGFBP-2 and IGFBP-3) and insulin (C-peptide) were measured together with urinary parameters of renal damage (beta(2)-microglobulin and proteinuria) by immunoassays, in house validated for the purpose, in 61 subjects (36 elite athletes, 18 recreational athletes and 7 sedentary individuals) with different levels of physical fitness and endurance exercise. Validation parameters were good for the evaluated assays, excluding a high inter-assay imprecision and inaccuracy of 24 and 26% obtained for GH assay. The range of concentrations found in urine samples under investigation was generally covered by the calibration curves of the studied immunoassays. However, for the samples below or above the calibration curve, opportune dilution or concentration were performed. Particularly, C-peptide samples had to be diluted 1:5 and beta(2)-microglobulin ones assayed using a triple sample volume, to fall within the calibration range. Urinary C-peptide was the only biomarker statistically higher in samples of elite athletes when compared to recreational athletes and sedentary individuals. Among elite athletes, tae-kwon-do athletes showed the highest IGF-II basal values while weightlifting athletes showed the lower IGF-I and IGFBP-3 basal values. The trend observed in weightlifters' basal samples was confirmed in their training samples: IGF-I, IGF-II, IGFBP-3 and beta(2)-microglobulin were lower in with respect to those from synchronised swimming. Over the training season, within athlete variability was observed for IGFBP-3 for weightlifting athletes. In the studied subjects, no direct associations were found between biomarkers of GH or insulin misuse and urinary parameters of renal damage, eventually due to high-workload endurance training. The variations observed in different biomarkers should be taken in consideration in the hypothesis of setting reference concentration ranges for doping detection.
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PMID:Effect of physical fitness and endurance exercise on indirect biomarkers of growth hormone and insulin misuse: Immunoassay-based measurement in urine samples. 2067 10

The growth hormone-insulin-like growth factor-insulin-like growth factor binding protein (GH-IGF-IGFBP) axis plays a critical role in the maintenance of normal renal function and the pathogenesis and progression of chronic kidney disease (CKD). Serum IGF-I and IGFBPs are altered with different stages of CKD, the speed of onset, the amount of proteinuria, and the potential of remission. Recent studies demonstrate that growth failure in children with CKD is due to a relative GH insensitivity and functional IGF deficiency. The functional IGF deficiency in CKD results from either IGF resistance due to increased circulating levels of IGFBPs or IGF deficiency due to increased urinary excretion of serum IGF-IGFBP complexes. In addition, not only GH and IGFs in circulation, but locally produced IGFs, the high-affinity IGFBPs, and low-affinity insulin-like growth factor binding protein-related proteins (IGFBP-rPs) may also affect the kidney. With respect to diabetic kidney disease, there is growing evidence suggesting that GH, IGF-I, and IGFBPs are involved in the pathogenesis of diabetic nephropathy (DN). Thus, prevention of GH action by blockade either at the receptor level or along its signal transduction pathway offers the potential for effective therapeutic opportunities. Similarly, interrupting IGF-I and IGFBP actions also may offer a way to inhibit the development or progression of DN. Furthermore, it is well accepted that the systemic inflammatory response is a key player for progression of CKD, and how to prevent and treat this response is currently of great interest. Recent studies demonstrate existence of IGF-independent actions of high-affinity and low-affinity-IGFBPs, in particular, antiinflammatory action of IGFBP-3 and profibrotic action of IGFBP-rP2/CTGF. These findings reinforce the concept in support of the clinical significance of the IGF-independent action of IGFBPs in the assessment of pathophysiology of kidney disease and its therapeutic potential for CKD. Further understanding of GH-IGF-IGFBP etiopathophysiology in CKD may lead to the development of therapeutic strategies for this devastating disease. It would hold promise to use of GH, somatostatin analogs, IGFs, IGF agonists, GHR and insulin-like growth factor-I receptor (IGF-IR) antagonists, IGFBP displacer, and IGFBP antagonists as well as a combination treatment as therapeutic agents for CKD.
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PMID:The insulin-like growth factor system in chronic kidney disease: Pathophysiology and therapeutic opportunities. 2688 6