Urinary Monocyte Chemoattractant Protein-1 Levels Research Articles

Correlations of Urinary Biomarkers, TNF-Like Weak Inducer of Apoptosis (TWEAK), Osteoprotegerin (OPG), Monocyte Chemoattractant Protein-1 (MCP-1), and IL-8 with Lupus Nephritis

This case-controlled study was designed to correlate urinary biomarkers, TNF-like weak inducer of apoptosis (TWEAK), osteoprotegerin (OPG), monocyte chemoattractant protein-1 (MCP-1), and interleukin-8 (IL-8) levels, with renal involvement in a cohort of systemic lupus erythematosus (SLE) patients to examine their diagnostic performance. In 73 SLE patients, and in 23 healthy volunteers, urinary levels of TWEAK, OPG, MCP-1, and IL-8 levels were measured. Disease activity was assessed by total SLE disease activity index, and renal activity by renal activity index (rSLEDAI), and both were correlated with urinary biomarkers. Sensitivity, specificity, and predictive values of individual biomarkers to predict lupus nephritis were also calculated. Significantly higher levels of urinary biomarkers were observed in SLE patients with lupus nephritis (LN) compared with those without LN (TWEAK, p < 0.001; MCP-1, p < 0.001; OPG, p < 0.001; IL-8, p < 0.032). Other significantly higher levels were observed in SLE patients with LN compared with control subjects (TWEAK, MCP-1, OPG, and IL-8 p < 0.001). Positive correlations were observed between rSLEDAI and TWEAK (r = 0.612 and p < 0.001), MCP-1 (r = 0.635 and p < 0.001), and OPG (r = 0.505 and p < 0.001). Urinary levels of TWEAK, OPG, and MCP-1 positively correlate with renal involvement as assessed by rSLEDAI with reasonable sensitivity, specificity, and predictive values to detect lupus nephritis while IL-8 was not significantly associated with global or rSLEDAI.

Urinary monocyte chemoattractant protein-1 correlates with disease activity in lupus nephritis

Monocyte chemoattractant protein-1 (MCP-1) has a pathogenic role in murine lupus nephritis (LN). We recruited 25 pediatric and adolescent systemic lupus erythematosus (SLE) patients from our lupus clinic [13 (52%) patients with LN and 12 (48%) lupus non-nephritis patients] and evaluated their urinary and plasma MCP-1 levels compared to adult and childhood controls. The median age and SLE disease duration of patients were 14.4 and 5.5 years, respectively. LN patients had a higher median renal (p=0.01) British Isles Lupus Assessment Group (BILAG) index, with a tendency for higher total BILAG scores (p=0.2). There were significantly increased urinary MCP-1 levels in the LN patients compared to healthy controls (p<0.001) whose values were significantly higher than lupus non-nephritis children (p<0.004). Urinary MCP-1 levels correlated well with total BILAG scores (r=0.82, p=0.04). There were no differences in plasma MCP-1 levels between SLE patient groups and pediatric controls, although the levels in the childhood controls were elevated compared to those of the adult controls (p<0.04). These results provide evidence of increased urinary--but not plasma--MCP-1 levels in children with LN, which correlates well with SLE disease activity as measured by the BILAG index.

Intensive insulin therapy decreases urinary MCP‐1 and ICAM‐1 excretions in incipient diabetic nephropathy

Nowadays, intensive insulin treatment has been widely used in type 2 diabetics who have poor control of blood glucose, to reduce the risk of chronic complications of diabetes. Recently, some scholars have paid more attention to the pivotal role of inflammation involved in type 2 diabetes and its complications. Monocyte chemoattractant protein-1 (MCP-1) and intercellular adhesion molecule-1 (ICAM-1), which are two important inflammatory chemokines, have been documented to participate in the onset and development of type 2 diabetes and its complications, such as diabetic nephropathy (DN). In the current study, we recruited 30 type 2 diabetics with microalbuminuria to be treated with multiple insulin injections daily for 2 weeks. Random spot urine samples (corrected for creatinine-Cr) were collected for the examination of urinary MCP-1, ICAM-1 and albumin (Alb) levels before and after the intensive insulin therapy. Changes in their levels were observed to test the hypothesis that type 2 diabetes with microalbuminuria is associated with elevated urinary concentrations of MCP-1 and ICAM-1, and intensive insulin therapy can result in a decline of Alb by reducing the inflammatory reaction. The urinary MCP-1/Cr and urinary ICAM-1/Cr ratios in type 2 diabetic patients with microalbuminuria were much higher than those in normal controls, and intensive insulin treatment could decrease significantly the urinary MCP-1/Cr, ICAM-1/Cr and Alb/Cr ratios in type 2 diabetics with microalbuminuria. Intensive insulin treatment may protect against renal injury in early DN by reducing the urinary MCP-1 and ICAM-1 excretions.

Urinary levels of epidermal growth factor, interleukin‐6 and monocyte chemoattractant protein‐1 may act as predictor markers of renal function outcome in immunoglobulin A nephropathy

Urinary cytokine excretion may reflect histological changes in immunoglobulin A nephropathy (IgAN), and their measurement can give information about disease outcome. Thirty-three IgAN patients were prospectively followed for 5.6 +/- 3.1 years. Urinary levels of monocyte chemoattractant protein-1 (MCP-1), interleukin (IL)-6 and epidermal growth factor (EGF) were measured at diagnosis and repeated 1 year later for IL-6 and EGF. Urinary MCP-1 and IL-6 levels were increased significantly, while EGF excretion reduced in IgAN patients, compared to controls. IL-6 urinary levels showed significant positive correlation with chronic histological lesions. Patients were classified into five groups, according to the Haas classification system. MCP-1 and IL-6 urinary levels were increased, whereas EGF levels were reduced in the progression of staging. EGF urinary excretion was a strong predictor factor of disease outcome, significantly correlated with creatinine clearance at time of diagnosis (r = 0.5, P = 0.005), and at the end of follow up (r = 0.6, P = 0.001). Urinary EGF levels measured a year later could predict long-term outcome better, and a cut of 0.05 pg/mg urine creatinine levels could distinguish between progressors and non-progressors. Urinary MCP-1, IL-6 and EGF levels may represent histology in IgAN. EGF excretion can be a predictive marker and its serial measurements may give information about disease outcome and the effect of treatment.

Reduced Albuminuria with Sarpogrelate Is Accompanied by a Decrease in Monocyte Chemoattractant Protein-1 Levels in Type 2 Diabetes

Sarpogrelate has been shown to reduce albuminuria in diabetic nephropathy. For examination of whether this is based on the same mechanisms as angiotensin II receptor blockers or thiazolidinedione, effects of sarpogrelate on atherosclerotic inflammatory molecules and their relations to albuminuria in patients who had diabetes and had already been treated with angiotensin II receptor blockers and with or without thiazolidinedione were examined. Forty patients who had diabetes with nephropathy and arteriosclerosis obliterans and had already been treated with angiotensin II receptor blocker (n = 40) were randomly assigned to sarpogrelate (300 mg/d; n = 20) or aspirin group (100 mg/d; n = 20). Plasma monocyte chemoattractant protein-1 and urinary albumin-to-creatinine ratio and monocyte chemoattractant protein-1 were measured at baseline and 16 wk after administration. Only the sarpogrelate group showed increases in plasma adiponectin and decreases in both plasma and urinary monocyte chemoattractant protein-1 and albumin-to-creatinine ratio levels. Moreover, percentage change of monocyte chemoattractant protein-1 level correlated positively to that of albumin-to-creatinine ratio. Even when the sarpogrelate group was further divided into two groups with (n = 9) or without thiazolidinedione (n = 11), changes in monocyte chemoattractant protein-1 or albumin-to-creatinine ratio did not differ. Sarpogrelate can reduce albuminuria and plasma and urinary monocyte chemoattractant protein-1 levels while increasing plasma adiponectin in diabetic nephropathy. These effects seem to be mediated via mechanisms that are different from those of angiotensin II receptor blocker or thiazolidinedione.

Effects of Long-Term Pravastatin Treatment on Serum and Urinary Monocyte Chemoattractant Protein-1 Levels and Renal Function in Type 2 Diabetic Patients with Normoalbuminuria

To explore the renoprotective and anti-inflammatory effects of pravastatin, we analyzed the changes in renal function and urinary monocyte chemoattractant protein-1 (MCP-1) level as a renal tubulointerstitial inflammatory biomarker and serum MCP-1 level as a systemic inflammatory biomarker following the introduction of treatment with 10 mg/day of pravastatin in 10 hyperlipidemic type 2 diabetic patients with normoalbuminuria. Twelve months of the pravastatin treatment did not affect urinary levels of albumin, transferrin, N-acetylglucosaminidase, or MCP-1 in the hyperlipidemic diabetic patients, whereas the treatment significantly reduced serum levels of MCP-1 in the patients. The pravastatin treatment effectively lowered low-density lipoprotein cholesterol (LDL-C) levels in the hyperlipidemic diabetic patients to levels nearly to those in 11 non-hyperlipidemic type 2 diabetic patients with normoalbuminuria. Interestingly, serum MCP-1 levels were significantly lower in the hyperlipidemic patients treated with pravastatin than in the non-hyperlipidemic patients. No significant correlation was observed between serum LDL-C and MCP-1 levels in all the data in the hyperlipidemic patients before and after the pravastatin treatment and in the non-hyperlipidemic patients. These results collectively indicate that pravastatin may ameliorate systemic vascular inflammation rather than local renal inflammation in hyperlipidemic type 2 diabetic patients with normoalbuminuria, independent of its cholesterol-lowering effects.

Possible Relationship between Adiponectin and Renal Tubular Injury in Diabetic Nephropathy

Adiponectin is an adipose-derived protein which has anti-inflammatory and anti-atherogenic properties in addition to insulin-sensitizing effects. To date, the role of adiponectin in the pathogenesis of diabetic nephropathy remains unclear. The aim of the present study was to explore the relationship between adiponectin and renal tubular injury in diabetic nephropathy. We determined serum and urinary adiponectin levels in type 2 diabetic patients with normoalbuminuria (n = 19), microalbuminuria (n = 18), and overt diabetic nephropathy (n = 16), and then analyzed the correlations between serum and urinary adiponectin, urinary N-acetylglucosaminidase (NAG) as a clinical marker of renal tubular injury, urinary monocyte chemoattractant protein-1 (MCP-1) as an inflammatory marker in renal tubulointerstitium, and clinical markers of renal disease. Notably, serum and urinary adiponectin levels were significantly increased in patients with overt diabetic nephropathy compared to those with normoalbuminuria and microalbuminuria. In univariate linear regression analysis, serum adiponectin levels were positively correlated with serum creatinine (r = 0.648, P<0.0001), urinary albumin (r = 0.583, P<0.0001), urinary NAG (r = 0.406, P<0.01), urinary MCP-1 (r = 0.514, P<0.0001), and urinary adiponectin (r = 0.691, P<0.0001) levels in all diabetic patients. Urinary adiponectin levels were also positively correlated with serum creatinine (r = 0.729, P<0.0001), urinary albumin (r = 0.799, P<0.0001), urinary NAG (r = 0.701, P<0.0001), and urinary MCP-1 (r = 0.801, P<0.0001) levels in all diabetic patients. Multiple linear regression analysis showed that serum creatinine and urinary adiponectin levels were independently associated with serum adiponectin levels (r(2) = 0.522), and that serum creatinine, urinary NAG, urinary MCP-1, and serum adiponectin levels were independent determinants of urinary adiponectin levels (r(2) = 0.851). These results collectively indicate that renal insufficiency and tubular injury possibly play a contributory role in increases in serum and urinary adiponectin levels in overt diabetic nephropathy. We presume that an increase in circulating adiponectin in overt diabetic nephropathy might be a physiological response to mitigate renal tubular injury and to prevent the further progression of diabetic nephropathy through its anti-inflammatory and anti-atherogenic effects.

Antibody blockade of TNF-α reduces inflammation and scarring in experimental crescentic glomerulonephritis

Tumor necrosis factor-alpha (TNF-alpha) is a proinflammatory cytokine produced by macrophages, and by renal mesangial and tubular epithelial cells. It stimulates the release of interleukin (IL)-1beta, monocyte chemoattractant protein-1 (MCP-1), and transforming growth factor-beta (TGF-beta). Blockade of TNF-alpha is currently used clinically in several autoimmune inflammatory diseases. We hypothesised that blocking TNF-alpha with a monoclonal antibody would prevent inflammation and renal fibrosis in crescentic glomerulonephritis. Nephrotoxic nephritis was induced in Wistar Kyoto (WKY) rats by intravenous injection of rabbit antirat glomerular basement membrane (GBM) nephrotoxic serum (NTS). Anti-TNF-alpha monoclonal antibody or saline was given intraperitoneally three times per week in four protocols: experiment 1, days 0 to 7; experiment 2, days 0 to 14 and days 4 to 14; experiment 3, days 4 to 28; and experiment 4, days 14 to 28. In experiment 1, rats treated from disease induction had less glomerular fibrinoid necrosis and fewer glomerular macrophages at day 7. In experiment 2, rats treated from day 0 or day 4 showed improved renal function, as judged by serum creatinine, with a significant reduction in crescents. In experiment 3, anti-TNF-alpha treatment significantly reduced urine protein to creatinine ratio and urinary MCP-1 levels. Serum creatinine was preserved at both day 14 and day 28. Tubulointerstitial inflammation, glomerular and tubulointerstitial scarring, and markers of fibrosis [alpha-smooth muscle actin (alpha-SMA) and type IV collagen] were significantly less in treated rats at day 28. In experiment 4, serum creatinine was higher and tubulointerstitial scarring was less in delayed-treated animals. Neutralization of endogenous TNF-alpha reduces glomerular inflammation, crescent formation, and tubulointerstitial scarring, with preservation of renal function, in experimental crescentic glomerulonephritis. TNF-alpha blockade is effective even when introduced at the time of maximum glomerular inflammation.

Involvement of extracellular signal-regulated kinase and p38 in human diabetic nephropathy

The involvement of mitogen-activated protein kinase (MAPK) in human diabetic nephropathy has not been fully investigated. The presence of cells positive for the phosphorylated MAPK family (phosphorylated extracellular signal-regulated kinase [p-ERK], phosphorylated p38MAPK [p-p38MAPK]) was investigated immunohistochemically in kidneys of 30 patients with diabetic nephropathy. In addition, 10 patients with minimal change nephrotic syndrome, 10 patients with thin basement membrane disease, and 5 patients with benign nephrosclerosis were studied as disease controls. The presence of activated nuclear factor-kappaB (p65)-positive cells also was evaluated in kidney specimens. In patients with diabetic nephropathy, p-ERK, p-p38MAPK, and p65 were observed in mesangial cells, endothelial cells, podocytes, tubular epithelial cells, and mononuclear infiltrates in interstitium. Numbers of p-ERK-, p-p38MAPK-, and p65-positive cells in both glomeruli and interstitium in patients with diabetic nephropathy were higher than those in controls. In particular, the number of glomerular p-ERK-positive cells in patients with diabetic nephropathy increased in accordance with the progression of glomerular lesions and correlated well with the number of glomerular p65-positive cells (r = 0.654; P < 0.01; n = 30). Conversely, the number of p-p38MAPK-positive cells in glomeruli did not correlate with glomerular lesions. However, the number of tubulointerstitial p-p38MAPK-positive cells in patients with diabetic nephropathy reflected the severity of tubulointerstitial lesions, and numbers of those in the interstitium increased with good correlation to numbers of tubulointerstitial p65-positive cells (r = 0.757; P < 0.01; n = 30) and interstitial CD68-positive macrophages (r = 0.647; P < 0.05; n = 30) and urinary monocyte chemoattractant protein-1 levels (r = 0.605; P < 0.05; n = 30). These results suggest that MAPK phosphorylation contributes to human diabetic nephropathy. In particular, ERK and p38MAPK may be distinctly involved in glomerular and tubulointerstitial lesions in human diabetic nephropathy.

High concentrations of interleukin-8 and monocyte chemoattractant protein-1 in urine of patients with acute Kawasaki disease.

We investigated urinary levels of interleukin-8 and monocyte chemoattractant protein-1 [1] in patients with acute Kawasaki disease. Kawasaki disease (KD) often presents with transient urinary abnormalities such as aseptic pyuria and proteinuria during the acute phase of illness [2, 3, 5]. Freshly voided urine samples from 19 KD patients, aged 2.9±1.6 years, were available during the febrile stage and the afebrile stage after treatment with 2 g/kg intravenous immune globulin over 5 days together with acetylsalicylic acid (30 mg/kg per day). For comparison, urine samples from seven patients aged 2.5±2.5 years, with congenital heart disease who did not show heart failure or urinary abnormalities were studied. During the febrile stage, 11 of 19 KD patients (58%) exhibited detectable levels of urinary interleukin-8 (IL-8) (840±855 pg/mg creatinine), whereas all controls had undetectable levels (Fig. 1a). Additionally, 7 of 19 KD patients (37%) exhibited urinary monocyte chemoattractant protein-1 (MCP-1) levels (1239±352 pg/mg creatinine) greater than 2 SD above mean control values (442±190 pg/mg creatinine) (Fig. 1b). Urinary levels of IL-8 and MCP-1 decreased significantly during the afebrile stage (P=0.01 and P=0.01, respectively) (Fig. 1a, T. Jibiki (&) Department of Paediatrics, Chiba Municipal Kaihin Hospital, 3-31-1 Isobe Mihama-ku, 261-0012 Chiba, Japan E-mail: t_jibiki@hotmail.com Tel.: +81-43-2777711 Fax: +81-43-2787482

Strong association of a functional polymorphism in the monocyte chemoattractant protein 1 promoter gene with lupus nephritis.

Lupus nephritis (LN) is a major contributor to morbidity and mortality in patients with systemic lupus erythematosus (SLE). There is evidence that polymorphisms in the genes of inflammatory mediators may predispose to the development of LN in patients with SLE. In this study, we examined the role of a functional monocyte chemoattractant protein 1 (MCP-1) polymorphism in SLE and LN. DNA and paired urine and serum samples were obtained from 134 SLE patients (> or =4 American College of Rheumatology criteria for SLE; 49 with and 85 without LN) and 118 controls. MCP-1 genomic variants were detected by polymerase chain reaction followed by restriction enzyme-fragment analysis. Urinary and serum MCP-1 levels and MCP-1 production by peripheral blood macrophages were measured by enzyme-linked immunosorbent assay. The A/A genotype was more common in controls than in SLE patients (P = 0.0002), whereas both the A/G (P = 0.009) and G/G (P = 0.0212) genotypes were more frequent in SLE patients. The A/A genotype was observed in only 23% of the patients with LN compared with 58% of those without LN (P < 0.0001). MCP-1 production by peripheral blood mononuclear cells from patients with the A/G and G/G phenotypes was markedly higher than the production by cells from patients with the A/A genotype. Urinary levels of MCP-1 were significantly higher in patients with LN. These results suggest that an A/G or G/G genotype may predispose to the development of SLE and further indicate that SLE patients with these genotypes may be at higher risk of developing LN. Moreover, measurement of urinary levels of MCP-1 may be a useful tool for the detection and management of LN.

Increased Urinary Excretion of Monocyte Chemoattractant Protein-1 in Proteinuric Renal Diseases

Monocyte chemoattractant protein-1 (MCP-1) is a chemokine that is produced mainly by tubular epithelial cells in kidney and contributes to renal interstitial inflammation and fibrosis. More recently, we have demonstrated that urinary MCP-1 excretion is increased in proportion to the degree of albuminuria (proteinuria) and positively correlated with urinary N-acetylglucosaminidase (NAG) levels in type 2 diabetic patients. Based on these findings, we have suggested that heavy proteinuria, itself, probably aggravates renal tubular damage and accelerates the disease progression in diabetic nephropathy by increasing the MCP-1 expression in renal tubuli. In the present study, to evaluate whether urinary MCP-1 excretion is increased in the proteinuric states not only in diabetic nephropathy but also in other renal diseases, we examined urinary MCP-1 levels in IgA nephropathy patients with macroalbuminuria (IgAN group; n = 6), and compared the results with the data obtained from type 2 diabetic patients with overt diabetic nephropathy (DN group; n = 23) and those without diabetic nephropathy (non-DN group; n = 27). Urinary MCP-1 excretion levels in non-DN, DN, IgAN groups were 157.2 (52.8–378.5), 346.1 (147.0–1276.7), and 274.4 (162.2–994.5) ng/g creatinine, median (range), respectively. Expectedly, urinary MCP-1 and NAG excretion levels in DN and IgAN groups were significantly elevated as compared with non-DN group. Therefore, we suggest that MCP-1 expression in renal tubuli is enhanced in proteinuric states, irrespective of the types of renal disease, and that increased MCP-1 expression probably contributes to renal tubular damage in proteinuric states.

Association of monocyte chemoattractant protein-1 with renal tubular damage in diabetic nephropathy

Monocyte chemoattractant protein-1 (MCP-1), is a chemokine that mediates renal interstitial inflammation, tubular atrophy, and interstitial fibrosis by recruiting monocytes/macrophages into renal tubulointerstitium. Recent studies have demonstrated that protein overload in renal tubular cells up-regulates MCP-1 gene and its protein expression. Therefore, we hypothesized that increased expression of MCP-1 in renal tubuli, probably triggered by an increase in the leakage of plasma protein from glomerular capillary to tubular fluid, may contribute to renal tubular damage and accelerate the progression of diabetic nephropathy. To test this hypothesis, we examined urinary excretion levels of MCP-1 and N-acetylglucosaminidase (NAG), a sensitive marker of renal tubular damage, in Japanese Type II diabetic patients with normoalbuminuria ( n=29), microalbuminuria ( n=25), and macroalbuminuria ( n=18). The median urinary excretion level of MCP-1 in patients with macroalbuminuria (394.4 ng/g creatinine) was significantly elevated compared to the levels in patients with normoalbuminuria and microalbuminuria (159.6 and 193.9 ng/g creatinine, respectively). Furthermore, the urinary MCP-1 excretion level was positively correlated with urinary excretion levels of albumin ( r=.816, P<.001) and NAG ( r=.569, P<.001) in all subjects. These results suggest that MCP-1 is produced in renal tubular cells and released into urine in proportion to the degree of proteinuria (albuminuria), and that increased MCP-1 expression in renal tubuli contributes to renal tubular damage. Therefore, we conclude that heavy proteinuria itself may accelerate the progression of diabetic nephropathy by increasing the MCP-1 expression in renal tubuli.

Urinary levels of monocyte chemoattractant protein-1 (MCP-1) and interleukin-8 (IL-8), and renal injuries in patients with type 2 diabetic nephropathy.

We examined the correlation among the levels of urinary monocyte chemoattractant protein-1 (MCP-1) and interleukin-8 (IL-8), hyperglycemia, and renal injuries in patients with type 2 diabetic nephropathy. The levels of urinary MCP-1, IL-8, protein excretion, blood urea nitrogen (BUN), serum creatinine (s-Cr), glycohemoglobin A1c (HbA1c), and fasting plasma glucose (FPG) were measured in 24 patients with type 2 diabetic nephropathy and 14 healthy adults as controls. Diabetic nephropathy was classified into three stages: stage 1 = normoalbuminuric, stage 2 = microalbuminuric, and stage 3 = macroalbuminuric. All of the patients showed normal ranges in renal function tests. Levels of urinary MCP-1 in all patients with diabetic nephropathy were significantly higher than those in healthy adults (P < 0.05). The levels of urinary MCP-1 in patients with diabetic nephropathy increased gradually according to the clinical stage of this disease. In contrast, the levels of urinary IL-8 in patients with diabetic nephropathy increased in stages 2 and 3. There was a significant correlation between the levels of urinary IL-8 and those of HbA1c. High glucose may stimulate MCP-1 and/or IL-8 production and their excretion into the urine independently of the phases or pathological lesions of this disease. It appears that IL-8 increased in the early stage of diabetic nephropathy, and MCP-1 increased in the advanced stage of this disease. It was concluded that measurement of urinary MCP-1 and IL-8 may be useful for evaluating the degree of renal injuries in patients with type 2 diabetic nephropathy.

Up-regulation of monocyte chemoattractant protein-1 in tubulointerstitial lesions of human diabetic nephropathy

We previously described that monocyte chemoattractant protein-1 (MCP-1) plays an important role in progressive glomerular and interstitial damage in inflammatory renal diseases. However, the expression of MCP-1 in diabetic nephropathy remains to be investigated. We examined whether locally expressed MCP-1 participates in human diabetic nephropathy via recruiting and activating monocytes/macrophages (Mphi). Urinary and serum MCP-1 levels were measured by enzyme-linked immunosorbent assay in 45 patients with diabetic nephropathy. The presence of MCP-1 in diseased kidneys was determined by immunohistochemical and in situ hybridization analyses. Urinary MCP-1 levels were significantly elevated in patients with diabetic nephrotic syndrome and advanced tubulointerstitial lesions. Moreover, urinary levels of MCP-1 were well correlated with the number of CD68-positive infiltrating cells in the interstitium. In contrast, serum MCP-1 levels remained similar to those of healthy volunteers. Furthermore, we detected the MCP-1-positive cells in the interstitium of diabetic nephropathy via both immunohistochemical and in situ hybridization analyses. These observations suggest that locally produced MCP-1 may be involved in the development of advanced diabetic nephropathy, especially in the formation of tubulointerstitial lesions possibly through Mphi recruitment and activation. Moreover, up-regulation of MCP-1 may be a common pathway involved in the progressive tubulointerstitial damage in diabetic nephropathy as well as inflammatory renal diseases.

Possible relationship of monocyte chemoattractant protein-1 with diabetic nephropathy

Monocyte chemoattractant protein-1 (MCP-1) is a specific chemokine to recruit and activate monocytes from the circulation to inflammatory site. In diabetic nephropathy, similar to other glomerulonephropathies, infiltration and activation of monocytes/macrophages in glomerulus have been implicated in the development of glomerular injury. The aim of the present study was to examine a possible relationship of MCP-1 with diabetic nephropathy and to investigate the role of glycated albumin (Gly-Alb) as well as high concentration of glucose (HG) on MCP-1 production by cultured human mesangial cells. MCP-1 in serum or urine and urinary albumin (Alb) as well as several clinical parameters such as plasma glucose, serum Gly-Alb, and hemoglobin A1c (HbA1c) were measured after overnight fasting in 16 control subjects and 54 diabetic patients. The relationships between the levels of urinary Alb and urinary or serum MCP-1 and also between the values of respective clinical parameter and urinary MCP-1 levels were analyzed. Next, using cultured human mesangial cells, we investigated the role of Gly-Alb and/or HG on the gene and protein expression of MCP-1. Urinary levels (ng/g creatinine), but not serum levels, of MCP-1 increased in accordance with the extent of albuminuria. In all subjects, there were significant correlations between the urinary levels of Alb and MCP-1 (r = 0.746, P < 0.0001) and between the levels of serum Gly-Alb and urinary MCP-1 (r = 0.475, P < 0.0001). In cultured human mesangial cells, the gene and protein expression of MCP-1 was dose and time dependently up-regulated by Gly-Alb. HG slightly but significantly stimulated MCP-1 expression. The combination of Gly-Alb and HG showed the greatest stimulation in more than an additive manner on MCP-1 production. This study suggests that facilitated MCP-1 production by mesangial cells in diabetic milieu contributes to the initiation and progression of diabetic nephropathy.

Urinary levels of monocyte chemo-attractant protein-1 correlate with tumour stage and grade in patients with bladder cancer.

To determine if the chemokine monocyte chemo-attractant protein-1 (MCP-1) is produced locally in patients with bladder cancer and to analyse a possible correlation between tumour stage, grade and metastatic spread, and the urinary and systemic levels of MCP-1. PATIENTS SUBJECTS AND METHODS: Urine and serum samples were obtained from 60 patients with bladder cancer and 20 control subjects. Tumour stage, grade, metastasis and nodal status were assessed. MCP-1 levels in serum and urine were determined using a sandwich enzyme-linked immunosorbent assay. Two transitional cell cancer cell lines (grade I and grade III) were analysed for MCP-1 production under normal and nutritive-stress cell culture. The correlation of urinary MCP-1 levels with tumour stage, grade and distant metastasis was highly significant. Patients with stage T2-T4 bladder cancer had three to fourfold higher mean MCP-1 concentrations (pg/mL) in their urine than those with T1 stage tumours or than the controls (controls 260; T1 359; T2 967; T3 917; T4 1829; P < 0.005). A tumour grade of > GI and the existence of distant metastasis (M1) also correlated significantly with higher urinary MCP-1 levels (GI 373; GII 661; GIII 1111; M0 644; M1 1379; P < 0.05). No differences in circulating serum MCP-1 level were detected between controls and patients. The low-grade (GI) RT4 bladder cancer cell line produced only traces of MCP-1, which did not change under nutritional stress; in contrast, the highly malignant T24 bladder cancer cell line (GIII) spontaneously secreted large amounts of MCP-1 (approximately 7000 pg/mL) which increased under nutritive stress to 13,000 pg/mL. MCP-1, as a potent monocyte chemo-attractant to tumour sites, is probably produced by bladder cancer cells; MCP-1 levels in the vicinity of the tumour (i.e. urine) correlate significantly with TNM stage and grade. As has already been shown in other neoplasms, the resulting monocyte/macrophage infiltrate possibly facilitates tumour neovascularization and tissue invasion. Therefore, MCP-1 levels in the urine of patients with bladder cancer may be a prognostic marker for the natural course of the disease, and modulation of this chemokine might be a future therapeutic approach for adjuvant treatment of bladder cancer.

Monocyte chemoattractant protein-1 and interleukin-8 levels in urine and serum of patents with hemolytic uremic syndrome.

The epidemic form of the hemolytic uremic syndrome (HUS) in children is hallmarked by endothelial cell damage, most predominantly displayed by the glomerular capillaries. The influx of mononuclear (MO) and polymorphonuclear cells (PMNs) into the glomeruli may be an important event in the initiation, prolongation, and progression of glomerular endothelial cell damage in HUS patients. The molecular mechanisms for the recruitment of these leukocytes into the kidney are unclear, but monocyte chemoattractant protein-1 (MCP-1) and IL-8 are suggested to be prime candidates. In this study, we analyzed the presence of both chemokines in 24-h urinary (n = 15) and serum (n = 14) samples of HUS children by specific ELISAs. Furthermore, kidney biopsies of three different HUS children were examined for MO and PMN cell infiltration by histochemical techniques and electron microscopy. Whereas the chemokines MCP-1 and IL-8 were present in only very limited amounts in urine of 17 normal control subjects, serial samples of HUS patients demonstrated significantly elevated levels of both chemokines. HUS children with anuria showed higher initial and maximum chemokine levels than their counterparts without anuria. A strong positive correlation was observed between urinary MCP-1 and IL-8 levels. Whereas initial serum IL-8 levels were significantly increased in HUS children, serum MCP-1 levels were only slightly elevated compared with serum MCP-1 in control children. No correlation was found between urinary and serum chemokine concentrations. Histologic and EM studies of HUS biopsy specimens clearly showed the presence of MOs and to a lesser extent of PMNs in the glomeruli. The present data suggest an important local role for MOs and PMNs in the process of glomerular endothelial-cell damage. The chemokines MCP-1 and IL-8 may possibly be implicated in the pathogenesis of HUS through the recruitment and activation of MOs and PMNs, respectively.

Urinary levels of monocyte chemoattractant protein (MCP)-1 and disease activity in patients with IgA nephropathy.

Using a quantitative sandwich ELISA, we studied 17 patients with IgA nephropathy to determine if levels of urinary monocyte chemoattractant protein-1 (MCP-1) might reflect the disease activity. The levels of urinary MCP-1 in patients with the advanced stage were significantly higher than those in patients with the mild stage of the disease, or in healthy controls. The results showed a significant correlation between the levels of urinary MCP-1 and the disease activity, i.e., levels of urinary casts and urinary protein. It was thus suggested that the measurement of urinary MCP-1 is useful in evaluating the degree of renal injuries and/or prognosis in patients with IgA nephropathy.

Increased urinary excretion of monocyte chemoattractant protein-1 during acute renal allograft rejection

Acute rejection is characterized histologically by infiltration of the interstitium by mononuclear cells. Monocyte chemoattractant protein 1 (MCP-1) has recently been identified as a monocyte chemotactic factor. This study examined the possible role of MCP-1 in renal transplantation. The concentration of MCP-1 in urine and serum of 19 renal transplant patients was investigated using an inhibition radioimmunoassay. The patients were divided into a non-rejection (NRj) and a rejection (Rj) group. Normal healthy volunteers were included as controls. Immunoperoxidase staining for MCP-1 and CD14, as a marker for macrophages, was performed in renal biopsies of transplant patients with rejection and six biopsies from histologically normal kidneys, as controls. The size of urinary MCP-1 was determined by gel filtration chromatography and in a number of fractions assessed for monocyte chemotactic activity using a modified Boyden chamber assay. Urinary excretion of MCP-1 in the Rj group ranged between 250 ng/mmol Cr and 3148 ng/mmol Cr with a median of 612 ng/mmol Cr. This is significantly higher than the results in the NRj group, ranging between 47 ng/mmol Cr and 288 ng/mmol Cr with a median of 229 ng/mmol Cr. In the normal control group, urinary MCP-1 levels ranged between 38 ng/mmol Cr and 74 ng/mmol Cr with a median of 50 ng/mmol Cr. The fractional excretion of MCP-1, calculated on the basis of MCP-1 and creatinine clearances, was found also to be significantly higher in the Rj group as compared to the NRj group. However, there was no significant difference in the serum levels of MCP-1 between the Rj, NRj, and normal control group. The intensity of MCP-1 staining in tubular epithelial cells and the degree of CD14+ cells in the interstitium was significantly higher in renal allograft biopsies than in the normal kidneys. In addition, MCP-1 isolated from urine of renal transplant patients with rejection was filtered with apparent molecular weight of 13 kDa and 11 kDa. Both sizes are chemotactically active for monocytes. These data suggest that urinary excretion of MCP-1 can be used as a marker for the episodes of acute rejection. The increase of urinary excretion of MCP-1 most likely is the result of local production by tubular epithelia cells. MCP-1 produced locally may, at least in part, be responsible for the influx of macrophages into the interstitium during rejection.