Gene expression of TWEAK/Fn14 and IP-10/CXCR3 in glomerulus and tubulointerstitium of patients with lupus nephritis

Aim: The role of the tumour necrosis factor‐like weak inducer of apoptosis (TWEAK)/Fn14 and interferon‐inducible protein (IP‐10)/CXCR3 axis in the pathogenesis of lupus nephritis were studied. Methods: The mRNA expression of TWEAK, Fn14, IP‐10 and CXCR3 were quantified in the glomerulus and tubulointerstitium of 42 patients with lupus nephritis (LN group) and 10 healthy controls. Results: As compared to controls, LN patients had higher glomerular expression of TWEAK and Fn14, but glomerular CXCR3 expression was lower in the LN group. Similarly, the LN group had higher tubulointerstitial expression of TWEAK and Fn14, but lower tubulointerstitial expression of CXCR3, than controls. Glomerular TWEAK expression of class V nephritis was significantly higher than class IV nephritis. Glomerular expression of CXCR3 significantly correlated with proteinuria (r = ?0.532; P = 0.019), whereas tubulointerstitial CXCR3 significantly correlated with serum creatinine (r = ?0.447; P = 0.029). Conclusion: In patients with lupus nephritis, there is an increase in intra‐renal expression of TWEAK and Fn14, and a decrease in CXCR3 expression. Intra‐renal expression of CXCR3 correlates with proteinuria and renal function. Our findings suggest that the TWEAK/Fn14 and IP‐10/CXCR3 axis may contribute to the pathogenesis of lupus nephritis.     

Effects of high glucose and TGF-beta1 on the expression of collagen IV and vascular endothelial growth factor in mouse podocytes

Effects of high glucose and TGF-beta1 on the expression of collagen IV and vascular endothelial growth factor in mouse podocytes. BACKGROUND: The podocyte takes center stage in the pathogenesis of glomerular basement membrane (GBM) thickening and proteinuria in diabetic glomerulopathy. In part, GBM thickening may occur when the podocyte synthesizes increased amounts of collagen IV. Proteinuria may develop if the podocyte secretes excessive amounts of vascular endothelial growth factor (VEGF), which may increase the glomerular permeability to macromolecules. The augmented production of collagen IV and VEGF may be caused by metabolic mediators of diabetes such as hyperglycemia and transforming growth factor-beta (TGF-beta). METHODS: The effects of high glucose and exogenous TGF-beta1 were examined on a mouse podocyte cell line that retains its differentiated phenotype. The gene expression and protein production of certain alpha chains of collagen IV, the major isoforms of VEGF, and components of the TGF-beta system were assayed. An inhibitor of TGF-beta signaling was used to determine whether some of the high glucose effects might be mediated by the TGF-beta system. RESULTS: Compared with normal glucose (5.5 mmol/L), high glucose (HG, 25 mmol/L) for 14 days stimulated [3H]-proline incorporation, a measure of collagen production, by 1.8-fold, and exogenous TGF-beta1 (2 ng/mL) for 24 hours stimulated proline incorporation by 2.4-fold. Northern analysis showed that exposure to HG for 14 days increased the mRNA level of alpha1(IV) collagen by 51% and alpha5(IV) by 90%, whereas treatment with TGF-beta1 (2 ng/mL) for 24 hours decreased the mRNA level of alpha1(IV) by 36% and alpha5(IV) by 40%. Consistent with these effects on mRNA expression, Western blotting showed that HG increased alpha1(IV) protein by 44% and alpha5(IV) by 28%, while TGF-beta1 decreased alpha1(IV) protein by 29% and alpha5(IV) by 7%. In contrast to their opposing actions on alpha1 and alpha5(IV), both HG and exogenous TGF-beta1 increased alpha3(IV) collagen and VEGF, with TGF-beta1 having the greater effect. An inhibitor of the TGF-beta type I receptor (ALK5) was able to prevent the stimulation of alpha3(IV) and VEGF proteins by HG. Unlike in other renal cell types, HG did not increase TGF-beta1 mRNA or protein in the podocyte, but HG did induce the expression of the ligand-binding TGF-beta type II receptor (TbetaRII). Because HG had up-regulated TbetaRII after two weeks, the addition of physiological-dose TGF-beta1 (0.010 ng/mL) for 24 hours stimulated the production of alpha3(IV) and VEGF proteins to a greater extent in high than in normal glucose. Up-regulation of TbetaRII in the podocyte was corroborated by immunohistochemistry of the kidney cortex in the db/db mouse, a model of type 2 diabetes. CONCLUSIONS: High glucose and exogenous TGF-beta1 exert disparate effects on the expression of alpha1 and alpha5(IV) collagen. However, high glucose and TGF-beta1 coordinately induce the production of alpha3(IV) collagen and VEGF in the podocyte. The HG-induced increases in alpha3(IV) collagen and VEGF proteins are mediated by the TGF-beta system. By increasing the expression of TbetaRII, high glucose may augment the response of the podocyte to ambient levels of TGF-beta1.     

Study of mRNA growth factors in urinary cells of kidney transplant recipients as predictors of chronic allograft nephropathy

BACKGROUND: Chronic allograft nephropathy (CAN) is responsible for a significant proportion of graft loss. Current diagnostic methods for CAN are inadequate, and noninvasive assays for detecting allograft dysfunction/rejection and predicting long-term outcomes are a priority in transplantation. METHODS: Urine samples were collected from 48 kidney transplant recipients (KTR): 18 recipients with stable graft function (creatinine levels<2.0 mg/dL) and proteinuria of less than 500 mg/24 hr (Group 1); 18 recipients with stable graft function and proteinuria of greater than 500 mg/24 hr (Group 2); and 12 recipients with biopsy confirmed CAN. Urinary cell levels of transforming growth factor-beta1 (TGF-beta1) mRNA or epidermal growth factor (EGF) mRNA were measured using real-time quantitative PCR assay, and levels were correlated with renal allograft status. The integrity of RNA isolated from urine sediments was also assessed using the Agilent 2100 Bioanalyzer. RESULTS: Urinary cell TGF-beta1 mRNA levels were higher in the CAN group compared to Group 1 (P<0.0001) or Group 2 (P<0.0001). Urinary cell EGF mRNA levels were higher in Group 1 compared to Group 2 (P<0.0001) or the CAN group (P<0.0001). There were no significant differences in the urinary cell levels of EGF mRNA between patients with greater than 500 mg/24 hr proteinuria (Group 2) and the CAN group (P=0.75). CONCLUSION: These results demonstrate that urinary cell TGF-beta1 mRNA levels distinguish CAN patients from long-term transplant patients with stable renal function and varied levels of proteinuria. Urinary cells may be a good resource for the noninvasive diagnosis of CAN.     

正常人与原发性肾小球肾炎及狼疮性肾炎患者血尿IL-18水平比较

目的:探讨IL-18在原发性肾小球肾炎(PGN)及狼疮性肾炎(LN)发生、发展中的作用,以及寻找有助于两类疾病的鉴别诊断和对肾组织炎症活动程度进行评估的指标。方法:应用酶联免疫吸附检测(enzyme-linkedimmunosorbent assay,ELISA)法测定16例正常人、21例原发性肾小球肾炎(PGN)患者和18例LN患者血浆和尿液IL-18水平的变化。结果:LN患者血浆及尿液IL-18水平显著高于正常对照组(P均<0.001)和PGN组(P均<0.05),而且WHOⅣ型LN患者血浆及尿IL-18水平均明显高于非Ⅳ型LN患者(P<0.05);PGN患者尿液IL-18水平也高于正常人(P<0.05),但血浆IL-18水平与正常人比较无统计学差异(P>0.05);LN患者血浆IL-18水平与SLEDAI呈正相关(P<0.01),而尿IL-18水平与狼疮性肾炎RHSAI是密切正相关(P<0.001),但尿IL-18水平与血浆IL-18水平相关性没有统计学意义(P>0.05)。结论:IL-18参与LN的全身免疫病理过程,但可能仅参与PGN肾组织局部炎症过程;血浆IL-18检测可能有助于区分LN和PGN,尿IL-18的检测可望作为一项估计LN肾组织病变活动程度的有用指标。     

Messenger RNA expression of target genes in the urinary sediment of patients with chronic kidney diseases.

BACKGROUND: The degree of renal scarring in kidney biopsy is an important prognostic factor in patients with chronic kidney diseases. We hypothesize that gene expression in the urinary sediment reflects the degree of renal damage. METHODS: We studied 29 patients with chronic kidney disease who underwent kidney biopsy (12 immunoglobulin-A nephropathy and 17 glomerulosclerosis) and 10 healthy controls. The mRNA expressions of a panel of target genes in urinary sediment were measured by real-time quantitative polymerase chain reaction. The results were compared with the degree of histological damage and renal function decline. RESULTS: There were significant differences in the urinary expression of transforming growth factor-beta (TGF-beta), monocyte chemotactic protein-1 (MCP-1) and collagen IV between disease groups and controls. Urinary TGF-beta mRNA expression correlated significantly with estimated glomerular filtration rate (r = -0.412, P = 0.029) and the degree of tubulointerstitial scarring (r = 0.418, P = 0.024). Urinary MCP-1 expression correlated with the degree of glomerulosclerosis (r = 0.450, P = 0.014), but not tubulointerstitial scarring. Urinary MCP-1 expression correlated with its corresponding level by enzyme-linked immunosorbent assay (ELISA) (r = 0.650, P<0.001), but TGF-beta expression did not correlate with its ELISA level. Urinary TGF-beta gene expression correlated with its intra-renal expression in glomeruli (r = 0.701, P<0.001) and tubulointerstitium (r = 0.573, P = 0.001) by immunohistochemistry, while urinary MCP-1 gene expression correlated with its staining in glomeruli (r = 0.576, P = 0.001) but not tubulointerstitium. After 12 months, there was a significant inverse correlation between the rate of renal function decline and urinary expression of connective tissue growth factor (r = -0.471, P = 0.010) and collagen I (r = -0.399, P = 0.032), but not TGF-beta or MCP-1. CONCLUSIONS: Amongst the target genes examined, the mRNA expression of TGF-beta in urinary sediment correlated with renal function, the degree of histological damage and intra-renal level in patients with chronic kidney diseases. Measurement of TGF-beta mRNA expression in urine may be a useful non-invasive tool for assessing the severity of renal damage in patients with chronic kidney diseases.     

2-(8-hydroxy-6-methoxy-1-oxo-1h-2-benzopyran-3-yl) propionic acid, an inhibitor of angiogenesis, ameliorates renal alterations in obese type 2 diabetic mice

One of the mechanisms involved in the progression of diabetic nephropathy, the most common cause of end-stage renal failure, is angiogenic phenomenon associated with the increase of angiogenic factors such as vascular endothelial growth factor (VEGF)-A and angiopoietin (Ang)-2, an antagonist of Ang-1. In the present study, we examined the therapeutic efficacy of 2-(8-hydroxy-6-methoxy-1-oxo-1H-2-benzopyran-3-yl) propionic acid (NM-3), a small molecule isocoumarin with antiangiogenic activity, using diabetic db/db mice, a model of obese type 2 diabetes. Increases in kidney weight, glomerular volume, creatinine clearance, urinary albumin excretion, total mesangial fraction, glomerular type IV collagen, glomerular endothelial area (CD31(+)), and monocyte/macrophage accumulation (F4/80(+)) observed in control db/db mice were significantly suppressed by daily intraperitoneal injection of NM-3 (100 mg/kg, for 8 weeks). Increases in renal expression of VEGF-A, Ang-2, fibrogenic factor transforming growth factor (TGF)-beta1, and chemokine monocyte chemoattractant protein-1 but not tumor necrosis factor-alpha were also inhibited by NM-3 in db/db mice. Furthermore, decreases of nephrin mRNA and protein levels in db/db mice were recovered by NM-3. In addition, treatment of db/db mice with NM-3 did not affect body weight, blood glucose, serum insulin, or food consumption. NM-3 significantly suppressed the increase of VEGF induced by high glucose in cultured podocytes and also suppressed the increase of VEGF and TGF-beta induced by high glucose in cultured mesangial cells. Taken together, these results demonstrate the potential use of NM-3 as a novel therapeutic agent for renal alterations in type 2 diabetes.     

Glomerular expression of CTGF, TGF-beta 1 and type IV collagen in diabetic nephropathy

BACKGROUND: In development of progressive extracellular matrix accumulation, connective tissue growth factor (CTGF) may act as a downstream mediator of transforming growth factor-beta 1 (TGF-beta 1). However, the association and the correlation of these cytokines and extracellular matrix accumulation in human diabetic nephropathy (DN) is not fully understood. METHODS: To explore the possible involvement of TGF-beta 1 and CTGF in extracellular matrix accumulation in DN, high-resolution in situ hybridization with digoxigenin-labeled antisense oligonucleotides to CTGF, TGF-beta 1 and type IV collagen mRNAs were performed in DN and in histologically normal human kidney (NHK). To quantify expression of each mRNA, the fraction of all nuclear cells that were positively stained in the cytoplasm was determined in at least 10 randomly selected cross-sections of nonsclerotic glomeruli. RESULTS: Both in DN and in NHK, CTGF, TGF-beta 1 and type IV collagen mRNAs were mainly expressed by glomerular mesangial, visceral epithelial and parietal epithelial cells. The percentages of positive glomerular resident cells were significantly higher for each mRNA in DN compared with NHK. Especially, the expression of CTGF mRNA was also notably increased in case of DN with only mild histopathologic lesions. The extent of expression of each mRNA was significantly correlated to that of each other mRNA examined. CONCLUSION: Our study indicated that CTGF and TGF-beta may play an important role in glomerular histopathologic change in DN.     

Clinical significance of urinary vascular endothelial growth factor and microvessel density in patients with renal cell carcinoma

Objectives. To investigate the urinary vascular endothelial growth factor (VEGF) levels from patients with renal cell carcinoma (RCC). Neovascularization, an essential event for the growth of solid tumors, is regulated by a number of angiogenic factors. VEGF is thought to exert potent angiogenic activity.Methods. Urine samples were obtained before radical nephrectomy from 27 patients with RCC and 10 control subjects with no evidence of cancer or inflammatory disease. VEGF was measured by enzyme-linked immunosorbent assay in the urine and corrected according to the 24-hour urine concentration of creatinine. The microvessel density was measured by immunohistochemical staining with CD31 monoclonal antibody. Nuclear morphometry was performed by photomicroscopy.Results. The corrected urinary VEGF levels in patients with RCC were much higher than those in the normal control group (P = 0.039) and were more elevated in patients with higher stages of RCC (Stages III and IV versus Stages I and II; P = 0.024). A tendency was also noted for the VEGF levels to be higher according to cell grade. However, no statistical correlation was found between the corrected urinary VEGF and age, sex, tumor size, cell type, microvessel density, platelet count, or hemoglobin. The nuclear area was higher with more advanced-stage tumors (P = 0.043) and tended to increase according to the tumor cell grade.Conclusions. The results of this study indicate that urinary VEGF levels are increased in patients with RCC. However, they may not reflect the underlying angiogenic activity, and it may be that other angiogenic factors play a more prominent role.     

Angiotensin II stimulates alpha3(IV) collagen production in mouse podocytes via TGF-beta and VEGF signalling: implications for diabetic glomerulopathy.

BACKGROUND: The podocyte is bathed in an angiotensin II (AngII)-rich ultrafiltrate, but the impact of AngII on podocyte pathobiology is not well known. Because podocytes play a direct role in the glomerular basement membrane (GBM) thickening of diabetes, the alpha3(IV) collagen chain was examined. Podocyte expression of alpha3(IV) collagen may involve the transforming growth factor-beta (TGF-beta) and vascular endothelial growth factor (VEGF) systems. METHODS: Cultured mouse podocytes were treated with various doses of AngII for selected periods of time, with or without inhibitors of TGF-beta and VEGF signalling, SB-431542 and SU5416, respectively. TGF-beta1 and VEGF were assayed by enzyme-linked immunosorbent assay (ELISA); alpha3(IV) collagen, TGF-beta type II receptor and phospho-Smad2 were assayed by immunoblotting. RESULTS: AngII >or=10(-10) M was found to stimulate the production of alpha3(IV) collagen significantly in as short a time as 3 h. The expression of alpha3(IV) collagen was influenced by the TGF-beta system, but AngII did not increase the podocyte's production of TGF-beta1 ligand; rather, it increased the expression of the TGF-beta type II receptor and activated the TGF-beta signalling system through Smad2. Despite the TGF-beta receptor upregulation, synergy between AngII and TGF-beta1 to boost alpha3(IV) collagen production was not observed. However, blockade of TGF-beta signalling with SB-431542 prevented AngII from stimulating alpha3(IV) collagen production. Podocyte expression of alpha3(IV) collagen was also increased by the autocrine activity of VEGF. Podocytes were stimulated to secrete VEGF by 10(-10) M or higher AngII after 48 h. Blockade of the endogenous VEGF activity by SU5416 prevented AngII-stimulated alpha3(IV) collagen production. CONCLUSIONS: AngII stimulates the podocyte to produce alpha3(IV) collagen protein via mechanisms involving TGF-beta and VEGF signalling. Alterations in alpha3(IV) collagen production may contribute to GBM thickening and perhaps proteinuria in diabetes.     

The effect of immunosuppressive therapy on the messenger RNA expression of target genes in the urinary sediment of patients with active lupus nephritis.

BACKGROUND: Previous studies have shown that messenger RNA (mRNA) expression of target genes is increased in the urinary sediment of patients with active lupus. We study the effect of immunosuppressive therapy on the urinary gene expression profile in patients with active lupus nephritis. Method. We recruited nine patients with active systemic lupus erythematosus (SLE) and renal disease, and required corticosteroid, with or without cytotoxic treatment. They were followed for 6 months, urine samples were collected at 0, 4, 12 and 24 weeks and gene expression profile was determined by polymerase chain reactions. The pattern of gene expression was compared to clinical parameters of therapeutic response. RESULTS: Amongst the target genes studied, there was a progressive decline in the urinary expression of T-bet, interleukin (IL)-10, transforming growth factor-beta (TGF-beta), monocyte chemoattractant protein-1 (MCP-1), and interferon-gamma (IFN-gamma) after immunosuppressive treatment, although the change of IFN-gamma was not statistically significant. The time course of their urinary expression was parallel to the systemic activity as reflected by the systemic lupus erythematosus disease activity index (SLEDAI). Throughout the study period, the SLEDAI score correlated significantly with the expressions of IFN-gamma (r = 0.43, P = 0.009), T-bet (r = 0.40, P = 0.016), TGF-beta (r = 0.51, P = 0.002) and MCP-1 (r = 0.38, P = 0.022). The anti-double strand(anti-ds)DNA antibody titer correlated significantly with the expressions of IFN-gamma (r = 0.45, P = 0.009), T-bet (r = 0.37, P = 0.034), IL-10 (r = 0.59, P<0.001), TGF-beta (r = 0.44, P = 0.010) and MCP-1 (r = 0.49, P = 0.004). On the other hand, the expression level of IL-2, IL-4, IL-12, IL-18 and GATA-3 remained static throughout the study period. CONCLUSIONS: The mRNA expression of T-bet, IL-10, TGF-beta, MCP-1, and probably IFN-gamma in the urinary sediment of patients with active lupus nephritis improves with successful immunosuppressive therapy, and the change in gene expression profile is in phase with the clinical disease activity. Measurement of urinary mRNA expression of target genes may be a potential non-invasive tool for the monitoring of lupus disease activity.     

Roles of tumour necrosis factor‐related weak inducer of apoptosis/fibroblast growth factor‐inducible 14 pathway in lupus nephritis

As one of the manifestations of patients with systemic lupus erythematosus, lupus nephritis (LN) has high morbidity and mortality. Although the explicit mechanism of LN remains to be fully elucidated, there is increasing evidence to support the notion that tumour necrosis factor‐related weak inducer of apoptosis (TWEAK), acting via its sole receptor, fibroblast growth factor‐inducible 14 (Fn14), plays a pivotal role in such pathologic process. TWEAK/Fn14 interactions occur prominently in kidneys of LN, inducing inflammatory responses, angiogenesis, mesangial proliferation, filtration barrier injuries, renal fibrosis, etc. This review will specify the important roles of TWEAK/Fn14 pathway in the pathogenesis of LN with experimental data from cellular and animal models. Additionally, the raised levels of urinary and serum soluble TWEAK correlate with renal disease activity in patients with LN. The neutralizing antibodies targeting TWEAK or other approaches inhibiting TWEAK/Fn14 signals can attenuate renal damage in the murine lupus models. Therefore, to focus on TWEAK/Fn14 signalling may be promising in both clinical evaluation and the treatment of patients with LN.     

The relationship between the VEGF levels and VEGF mRNA expression and clinical course in different glomerulonephritis

In this study, serum and urinary VEGF levels and VEGF expression in PBMNC were correlated with daily proteinuria, renal function tests, and renal histopathologic findings in untreated patients with different glomerulonephritis and with the course of renal function and proteinuria for one year. Forty-five untreated patients with different glomerulonephritis and 11 healthy persons comprised the study and control groups, respectively. VEGF mRNA expression was detected by RT- PCR in peripheral blood mononuclear cells (PBMNC), and VEGF levels were measured by ELISA in serum and urine samples simultaneously. Male/female ratio was 24/21 and mean ages were 34.49 +/- 14.98. Serum and urinary VEGF levels, VEGF expressions in PBMNC, and the ratios of urine VEGF/urine creatinine were found to be similar in patients and controls. There were important correlations between urinary VEGF levels and baseline serum Cr (p = 0.035) and ESR (p = 0.022). There was also a marginal correlation between urinary VEGF levels and baseline CCr (p = 0.072). There was no correlation between serum and urinary VEGF levels and PBMNC mRNA expression and pathological findings such as with or without glomerular sclerosis, tubulointerstitial fibrosis (TIF), periglomerular fibrosis, and mesangial cell proliferation in renal biopsy. Serum and urinary VEGF levels or VEGF expression in PBMNC in patients with renal amyloidosis or proliferative or nonproliferative glomerulonephritis were similar with that of healthy controls and each other. Serum and urinary VEGF levels and PBMNC VEGF mRNA expression in untreated patients with different glomerulonephritis and controls were similar. We found only one important correlation, that between urinary VEGF levels and baseline serum creatinine levels in patients with different glomerulonephritis. Urinary VEGF can be an important pathogenesis of glomerular disease or a simple proteinuria. Serum and urinary VEGF levels and PBMNC VEGFmRNA did not change by periglomerular sclerosis, periglomerular fibrosis, or tubulointerstitial fibrosis on renal biopsy. PBMNC VEGF mRNA expression decreased in patients undergoing remission. In addition to the important correlation between urinary VEGF and serum creatinine, we also found an important correlation between erythrocyte sedimentation rate and urinary VEGF. This finding was interesting because we could not find a similar conclusion in other studies.     

Conversion from calcineurin inhibitors to sirolimus in kidney transplant patients reduces the urinary transforming growth factor-beta1 concentration

INTRODUCTION: Chronic allograft dysfunction (CAD) is the main cause of late transplant failure. Although several etiologies have been postulated, toxicity for calcineurin inhibitors (CNIs) is one of the most important causes of CAD, characterized by arteriolar hyalinosis, luminal narrowing, increased glomerulosclerosis, and tubulointerstitial damage. It's known that in transplant patients with CAD, fibrogenic mediators such as transforming growth factor beta (TGF-beta) are increased. Sirolimus is an immunosuppressive agent with a distinct mechanism of action compared with CNI. AIM: This study assessed variations in levels of fibrogenic mediators among CAD patients treated with CNIs, before and after conversion to sirolimus. PATIENTS AND METHODS: We studied twelve renal transplant patients with CAD on CNI treatment. TGF-beta in plasma and urine, endothelin-1, and vascular endothelial growth factor (VEGF) were studied before and 8 months after conversion to sirolimus treatment. RESULTS: TGF-beta urine levels decreased from 24.7 +/- 11.2 to 12.8 +/- 5.1 ng/24 h (P = .049). In plasma, a similar decrease trend was observed (22.2 +/- 32 to 10.3 +/- 3 ng/mL), although it was not significant (P = .079). Endothelin-1 showed a decrease (8.1 +/- 3 to 5.2 +/- 1.1 pmol/L; P = .1) and VEGF in plasma increased from 34.3 +/- 37 to 92.2 +/- 86 pg/mL (P = .051). CONCLUSIONS: Patients undergoing conversion from CNI to sirolimus treatment for CAD presented a significant decrease in TGF-beta urine levels, representing a decreased mediator of the CAD fibrogenic process.     

Laminin and transforming growth factor beta-1 in children with vesicoureteric reflux

High-grade vesicoureteric reflux (VUR) promotes the development of renal nephropathy (RN) due to scar formation. This process involves transforming growth factor beta-1 (TGF beta₁), which stimulates production of the extracellular matrix proteins, including laminin (LN). The aim of the study was to assess LN and TGF beta₁ concentration according to VUR grade. The study group (1) consisted of 54 patients aged 6.23 ± 4.15 years with VUR, including: A, 19 with grade II; B, 19 with grade III; and C, 16 with grades IV or V reflux. The control group (2) contained 27 healthy patients aged 6.76 ± 4.02 years. LN and total TGF beta₁ concentrations in serum and urine were determined by the immunoenzymatic (EIA) method. To assess total serum TGF beta₁ levels, we used a solid-phase enzyme-linked immunosorbent assay (ELISA). Both serum and urinary levels of LN and TGF beta₁ in VUR patients were higher compared with controls (p < 0.05). The highest urinary concentration of LN and TGF beta₁ was found in subgroup C. A positive correlation was noted between urinary TGF beta₁ and LN. Increased TGF-beta₁ and LN levels in urine of high-grade VUR children suggests a potential role in fibrogenesis. Further trials are needed to investigate the role of serum and urinary LN level in VUR children.     

Pelvi-ureteric junction obstruction in children: the role of urinary transforming growth factor-beta and epidermal growth factor

OBJECTIVES: To investigate the role of transforming growth factor beta(1) (TGF-beta(1)) and epidermal growth factor (EGF) in voided urine for the diagnosis and follow-up of children with pelvi-ureteric junction obstruction (PUJO). PATIENTS, SUBJECTS AND METHODS: The study included 35 children with unilateral PUJO who had a pyeloplasty, and 30 healthy control children. Urine samples were obtained from the bladders of patients before surgery, and as voided samples at 1, 2, 3, 6, 9 and 12 months after surgery. Bladder urine samples were also collected from all 30 children in the control group. TGF-beta(1) and EGF were then measured in all the urine samples. RESULTS: The level of bladder TGF-beta(1) before surgery in the patients was significantly higher than that in the healthy control group. A threshold of 190 pg/mg creatinine gave a sensitivity of 100%, a specificity of 80%, a positive predictive value of 85.4%, negative predictive value of 100% and an overall accuracy of 90.8%. Compared with the value before surgery, urinary TGF-beta(1) was significantly lower at 1 year after pyeloplasty. There was no significant difference between the level of EGF before surgery in the patients and that in the control group, and no significant difference in the level of EGF before and after surgery over the follow-up. CONCLUSION: We do not recommend using EGF levels in voided urine in the routine diagnosis of children with hydronephrosis. The urinary level of TGF-beta(1) is a useful noninvasive tool for the long-term follow-up of children with PUJO treated by pyeloplasty. Further studies with various controls are required to confirm the diagnostic accuracy of TGF-beta(1) in children with PUJO.     

The Relationship between the VEGF Levels and VEGF mRNA Expression and Clinical Course in Different Glomerulonephritis

In this study, serum and urinary VEGF levels and VEGF expression in PBMNC were correlated with daily proteinuria, renal function tests, and renal histopathologic findings in untreated patients with different glomerulonephritis and with the course of renal function and proteinuria for one year. Forty-five untreated patients with different glomerulonephritis and 11 healthy persons comprised the study and control groups, respectively. VEGF mRNA expression was detected by RT- PCR in peripheral blood mononuclear cells (PBMNC), and VEGF levels were measured by ELISA in serum and urine samples simultaneously. Male/female ratio was 24/21 and mean ages were 34.49 ± 14.98. Serum and urinary VEGF levels, VEGF expressions in PBMNC, and the ratios of urine VEGF/urine creatinine were found to be similar in patients and controls. There were important correlations between urinary VEGF levels and baseline serum Cr (p = 0.035) and ESR (p = 0.022). There was also a marginal correlation between urinary VEGF levels and baseline CCr (p = 0.072). There was no correlation between serum and urinary VEGF levels and PBMNC mRNA expression and pathological findings such as with or without glomerular sclerosis, tubulointerstitial fibrosis (TIF), periglomerular fibrosis, and mesangial cell proliferation in renal biopsy. Serum and urinary VEGF levels or VEGF expression in PBMNC in patients with renal amyloidosis or proliferative or nonproliferative glomerulonephritis were similar with that of healthy controls and each other. Serum and urinary VEGF levels and PBMNC VEGF mRNA expression in untreated patients with different glomerulonephritis and controls were similar. We found only one important correlation, that between urinary VEGF levels and baseline serum creatinine levels in patients with different glomerulonephritis. Urinary VEGF can be an important pathogenesis of glomerular disease or a simple proteinuria. Serum and urinary VEGF levels and PBMNC VEGFmRNA did not change by periglomerular sclerosis, periglomerular fibrosis, or tubulointerstitial fibrosis on renal biopsy. PBMNC VEGF mRNA expression decreased in patients undergoing remission. In addition to the important correlation between urinary VEGF and serum creatinine, we also found an important correlation between erythrocyte sedimentation rate and urinary VEGF. This finding was interesting because we could not find a similar conclusion in other studies.     

Urine biomarkers in juvenile-onset SLE nephritis

Over 80 % of patients with juvenile-onset systemic lupus erythematosus will have renal involvement compared to 40 % with adult-onset disease. Up to 44 % of children who do have lupus nephritis (LN) progress to renal failure in early adulthood. Improved methods of detecting onset of LN would allow earlier treatment, which may prevent irreversible renal scarring and a decline in renal function. Current conventional markers of disease activity fail to adequately predict renal lupus flares and include proteinuria, complement levels, anti-double-stranded DNA antibodies and serum creatinine concentrations. Standardized histological classification is currently the gold standard for diagnosing and classifying LN, but its invasive nature limits routine use for monitoring, especially in a childhood population. Novel biomarkers need to be sensitive and specific—and preferably non-invasive and cost-effective. The most promising biomarkers in juvenile-onset LN include urinary neutrophil gelatinase associated lipocalin, monocyte chemoattractant protein 1 and transforming growth factor-beta, although many others have been identified and are under investigation. No one biomarker yet discovered is unique to LN, indicating an overlap in disease pathophysiology. It is likely that a combination of biomarkers will be required for assessing disease flare detection, response to treatment and prognostic information. Potential biomarkers require longitudinal validation in large paediatric, prospective cohorts to assess their ability to act as clinically useful adjuncts.     

Urinary vascular endothelial growth factor and its correlation with bladder cancer recurrence rates

PURPOSE: Vascular endothelial growth factor (VEGF) is a principal growth factor mediating tumor angiogenesis. The high expression of VEGF within bladder tumors is associated with a poor prognosis. We quantified urinary VEGF and determined its potential as a prognostic marker in bladder cancer. MATERIALS AND METHODS: VEGF was measured by enzyme-linked immunosorbent assay in the urine of 261 patients, including 153 undergoing cystoscopic surveillance for bladder cancer and 108 with another advanced malignancy or a benign urological condition. The source of urinary VEGF was studied through its quantification in bladder tumors and normal bladders. RESULTS: Urinary VEGF was higher in patients undergoing cystoscopic surveillance for bladder cancer than in those with an advanced nonbladder malignancy (p <0.0001) or a benign urological condition (p = 0.004). The highest levels were noted in patients with bladder cancer compared to those with clear cystoscopy (p <0.0001). In 26 cases the correlation between VEGF protein levels in bladder cancer and urine (r = 0.67, p = 0.003) suggested that the tumor is a source of urinary VEGF. Increased VEGF protein in normal urothelium in 22 patients with bladder cancer compared to that in 7 cadaveric organ donors (p = 0.002) indicates that urinary VEGF may also be derived from nonmalignant urothelium. In 61 cases we established a correlation between urinary VEGF and stage T1 or less superficial bladder tumor recurrence rates (r = 0.45, p <0.0001). CONCLUSIONS: Our study demonstrates that VEGF is high in the urine of patients with bladder cancer and it correlates with tumor recurrence rates. VEGF is implicated in the pathogenesis of bladder cancer recurrence. Its quantification may provide a valuable noninvasive marker for the early detection of bladder tumor recurrence as well as a therapy target.