Fibrinogen-like protein 2 expression correlates with microthrombosis in rats with type 2 diabetic nephropathy

Fibrinogen-like protein 2 (fgl2),a novel prothrombinase,is involved in microthrombosis.We examined fgl2 expression in the glomerular and tubulointerstitial capillaries and its correlation with microthromsis in rats with streptozocin-induced type 2 diabetic nephropathy.Our RT-PCR and immunoblotting analysis showed that fgl2 mRNA and protein levels were increased in microvascular endothelial cells of the glomeruli and renal interstitia at week 19 and became significantly elevated with the development of diabetic nephropathy (P < 0.01).Fgl2 was not or only weakly expressed in the renal tissues of normal rats.Furthermore,a direct significant correlation (r=0.543,P < 0.01) was found between fgl2 expression and microthrombotic capillaries in the renal tissues.Enzyme linked immunosorbent assays (ELISA) additionally showed that circulating TNF-α levels in rats with type 2 diabetes were significantly elevated and closely correlated with fgl2 expression (r=0.871,P < 0.01).Our results suggest that fgl2 may activate renal microthrombosis,thus contributing to glomerular hypertension and renal ischemia.     

Renal macrophage infiltration is associated with a poor outcome in IgA nephropathy

OBJECTIVES:

The objectives of our study were as follows: 1) to analyze the prognostic value of macrophage infiltration in primary IgA nephropathy (IgAN) and 2) to study the relationship between macrophages and other factors associated with the development of renal fibrosis, including mast cells, TGF-β1, α-SMA and NF-kB.

METHODS:

We analyzed 62 patients who had been diagnosed with IgAN between 1987 and 2003. Immunohistochemical staining was performed with monoclonal antibodies against CD68 and mast cell tryptase and polyclonal antibodies against TGF-β1, α-SMA and NF-kB p65. We also used Southwestern histochemistry for the in situ detection of activated NF-kB.

RESULTS:

The infiltration of macrophages into the tubulointerstitial compartment correlated with unfavorable clinical and histological parameters, and a worse clinical course of IgAN was significantly associated with the number of tubulointerstitial macrophages. Kaplan-Meier curves demonstrated that increased macrophage infiltration was associated with decreased renal survival. Moreover, the presence of macrophages was associated with mast cells, tubulointerstitial α-SMA expression and NF-kB activation (IH and Southwestern histochemistry). In the multivariate analysis, the two parameters that correlated with macrophage infiltration, proteinuria and tubulointerstitial injury, were independently associated with an unfavorable clinical course.

CONCLUSION:

An increased number of macrophages in the tubulointerstitial area may serve as a predictive factor for poor prognosis in patients with IgAN, and these cells were also associated with the expression of pro-fibrotic factors.     

Role of mast cells, stem cell factor and protease-activated receptor-2 in tubulointerstitial lesions in IgA nephropathy

Background

To elucidate the role of mast cells (MCs) in the pathogenesis of tubulointerstitial lesions in IgA nephropathy (IgAN), we investigated the number of MCs, serum stem cell factor (SCF), protease-activated receptor-2 (PAR-2) and α-smooth-muscle actin (α-SMA) in the kidney and the correlation between MC number, SCF, PAR-2, α-SMA and tubulointerstitial lesions in biopsy specimens and serum creatinine levels, urinary protein excretion in patients with IgA nephropathy.

Methods

Thirty-five patients with IgA nephropathy were enrolled in this study. Clinical parameters, such as serum creatinine and urinary protein excretion, were obtained from each patient at the time of biopsy. Paraffin-embedded sections were used for immunohistochemical staining. Monoclonal antibodies to human tryptase, α-SMA, and SCF and polyclonal antibody to PAR-2 were used as primary antibodies. Ten cortical interstitial fields were randomly selected and assessed using a computer-assisted color image analyzer. Tubulointerstitial fibrosis was assessed as the percentage of the area stained with Masson trichrome in ten cortical interstitial fields.

Results

In all of the control subjects, few tryptase-positive MCs were observed in the glomeruli and interstitium. In contrast, sparse MCs were observed in the interstitium, but not in the glomeruli of diseased kidneys. The number of interstitial MCs in the tubulointerstitial lesions, the expression of SCF, PAR-2 and α-SMA were positively correlated with the degree of interstitial fibrosis. A close correlation between MCs, α-SMA, PAR-2 and SCF was found (r = 0.887 for α-SMA, r = 0.844 for PAR-2, r = 0.853 for SCF, P < 0.01). Also a close correlation between α-SMA, PAR-2 and SCF was found (r = 0.874 for PAR-2, r = 0.862 for SCF, P < 0.01). PAR-2 was correlated with SCF (r = 0.893, P < 0.01). Moreover, a significant positive correlation was observed between the number of interstitial MCs, the expression of SCF, PAR-2 and α-SMA and the serum creatinine level (r = 0.738 for MCs, r = 0.658 for α-SMA, r = 0.692 for PAR-2, r = 0.754 for SCF, P < 0.05).

Conclusions

Our findings suggest that MC infiltration possibly induced by SCF in renal interstitial tissues seems to be associated with tubulointerstitial fibrosis through PAR-2 in IgA nephropathy.     

Mast cells, TGF-beta1 and alpha-SMA expression in IgA nephropathy

IgA nephropathy (IgAN) is a kidney disease with a varying renal prognosis. Recently, many studies have demonstrated that renal alpha-smooth muscle actin (alpha-SMA) and transforming growth factor (TGF-beta1) expression, as well interstitial mast cell infiltrates could represent a prognostic marker in several renal diseases. The aim of our study was to analyze the prognostic value of mast cell, TGF-beta1 and alpha-SMA expression in IgAN. A survey of the medical records and renal biopsy reports of 62 patients with a diagnosis of IgAN followed-up from 1987 to 2003 was performed. The mean follow-up time was 74.7 +/- 50.0 months. The immunohistochemical studies were performed using a monoclonal antibody anti-human mast cell tryptase, a polyclonal antibody anti-human TGF-beta1, and a monoclonal antibody anti-human alpha-SMA. An unfavorable clinical course of IgAN was related to interstitial mast cell infiltrates and alpha-SMA expression in the tubulointerstitial area. Expression of glomerular TGF-beta1 and alpha-SMA, and interstitial TGF-beta1 is not correlated with clinical course in IgAN. In conclusion, the increased number of mast cells and higher alpha-SMA expression in the tubulointerstitial area may be predictive factors for the poor prognosis of patients with IgAN.     

Smoking-Related Renal Histologic Injury in IgA Nephropathy Patients

Purpose

Smoking reportedly exerts deleterious effects on renal function; however, its effects on histology have not been clarified in patients with IgA nephropathy (IgAN).

Materials and Methods

Renal histology was evaluated in a cohort of 397 patients diagnosed with IgAN according to smoking status and dose in relation to renal function.

Results

Among the study cohort, which was predominantly male (88.5%), 52 patients (13%) were current smokers. These current smokers demonstrated more frequent hypertension and higher serum creatinine levels than non/ex-smokers at the time of diagnosis, which was apparent with increased smoking dose. The percentages of global glomerulosclerosis and arteriolar hyalinosis increased with increased smoking dose, whereas tubulointerstitial fibrosis or arterial intimal thickening did not. Glomerular mesangial alpha-smooth muscle actin expression were similar between current and non/ex-smokers matched for age, gender, hypertension, and histologic severity, although the number of glomerular CD68+ cells was significantly fewer in smokers. Initial serum creatinine level, estimated glomerular filtration rate (eGFR), and global glomerulosclerosis were found to be risk factors of serum creatinine doubling in both smokers and non/ex-smokers by univariate analysis during a mean follow-up of 3.8 years.

Conclusion

In addition to dose dependent renal functional decline and hypertension, smoking contributes to renal disease progression by eliciting microvascular injury in IgAN patients.     

The expression of Toll‐like receptors 2, 4 and 9 in kidneys of patients with anti‐neutrophil cytoplasmic antibody (ANCA)‐associated vasculitis

Increasing evidence suggested that Toll-like receptors (TLRs) were critically involved in immune responses of anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). The current study aimed to investigate the expression of TLR-2, TLR-4 and TLR-9 in kidneys of patients with ANCA-associated vasculitis. Renal biopsy specimens were collected from 24 patients with AAV. The expression of TLR-2, TLR-4 and TLR-9 in kidneys was detected by immunohistochemistry. Double immunofluorescence staining was performed to detect the expression of TLRs on various kinds of cells. In renal specimens, immunohistochemical examination revealed that expression of TLR-2 and TLR-4 could be detected in the glomeruli of AAV patients, while TLR-2 and TLR-4 were scarcely detected in the glomeruli of normal controls. Double immunofluorescence staining of TLR-2, TLR-4 and CD31 indicated that TLR-4 and TLR-2 were expressed on endothelial cells in the glomeruli. In the tubulointerstitial compartment, expression of TLR-2, TLR-4 and TLR-9 could be detected in both AAV patients and normal controls. The mean optical density of TLR-2 and TLR-4 in the tubulointerstitial compartment in AAV patients were significantly higher than that in normal controls. Among AAV patients, correlation analysis showed that the mean optical density of TLR-4 in the glomeruli correlated inversely with the initial serum creatinine, the proportion of total crescents and the proportion of cellular crescents in renal specimens (r = −0·419, P = 0·041; r = −0·506, P = 0·012; r = −0·505, P = 0·012, respectively). The expression of TLR-2 and TLR-4 was dysregulated in kidneys of AAV patients. The expression of TLR-4 in glomeruli was associated with the severity of renal injury.     

Grading of acute and chronic renal lesions in Henoch-Sch?nlein purpura.

The renal outcome of 34 patients with Henoch-Sch?nlein purpura nephritis was assessed clinically and by grading acute and chronic renal lesions using a system we applied to primary IgA nephropathy. On a median follow-up period of 65 months, hypertension and the serum levels of creatinine and proteinuria at the time of renal biopsy were correlated with renal survival. Acute glomerular lesions including mesangial hypercellularity, endocapillary proliferation, necrosis, cellular crescents, and leukocytes infiltration were observed, respectively, in 41%, 12%, 50%, 29%, and 32% of the cases. Of these, only glomerular necrotizing lesion and cellular crescent were correlated with the renal survival. Chronic renal lesions based on a grading system applied to primary IgA nephropathy and assessing the extent of glomerular sclerosis (glomerular grading), of tubular loss and interstitial fibrosis (tubulointerstitial grading), and of hyaline arteriolosclerosis demonstrated correlation between these lesions, as well as with renal survival. On follow-up, these chronic renal lesions were predictors of subsequent clinical events associated with disease progression, such as impaired renal function, significant proteinuria, and development of hypertension. Despite some limitations related to the relatively small size, this series indicates that distinction of acute and chronic lesions of Henoch-Schonlein purpura nephritis is important for both the prognosis and management of patients.     

Rutin ameliorates renal fibrosis and proteinuria in 5/6-nephrectomized rats by anti-oxidation and inhibiting activation of TGFβ1-smad signaling

Objectives: Rutin, a polyphenolic flavonoid, was reported to have beneficial effect on drug induced nephropathy. The present study aimed to introduce 5/6 nephrectomized rat model to further evaluate its renal protective effect. Methods: Adult Wistar rats were induced to develop chronic renal failure through 5/6 nephrectomy (5/6 Nx). After that, animals were treated orally with saline, rutin at 15 and 45 mg/kg, and losartan (10 mg/kg) daily for 20 weeks; sham-operated animals were also involved as control. After treatment for 8 and 20 weeks, blood and urine samples were collected for biochemical examination; all the kidney remnants were collected for histological examination. The protein levels of TGF-β1, smad2 and phosphorylated-smad2 (p-smad2) in kidney were measured. Immunohistochemistry was used to analyze the expression of TGF-β1, fibronectin and collagen IV in kidney tissues. Results: Results suggested that rutin could reduce the proteinurea, blood urine nitrogen and blood creatinine in 5/6 Nx animals significantly, as well as oxidation stress in the kidney. By histological examination, rutin administration alleviated glomerular sclerosis scores and tubulointerstitial injuries in a dose-dependent manner (P<0.01). Immunohistochemistry also suggested rutin could reduce the expression of TGF-β1, fibronectin and collagen IV in kidney tissues. By western blot, we found the rutin could reduce the TGF-β1, p-smad2 expression in the kidney tissues of rats. Conclusions: This study suggests that the rutin can improve renal function in 5/6 Nx rats effectively. Its effect may be due to its anti-oxidation and inhibiting TGFβ1-Smad signaling.     

Anti-inflammatory effects of triptolide on IgA nephropathy in rats

Abstract

IgA nephropathy (IgAN) is the finding of immune deposits predominantly containing polymeric IgA in the glomerular mesangium on renal biopsy. Recently studies show that inflammation may involve in the progression of renal glomerulosclerosis and tubulointerstitial scarring in IgAN. This study was designed to evaluate the renoprotective effect of triptolide on IgAN rat model. IgAN was induced in Sprague–Dawley rats by oral and intravenous immunization with BSA for 12 weeks. Rats were treated with triptolide (200?μg/kg/d intragastrically) from 12 to 28 weeks. At Week 28, the rats was sacrificed, kidneys and blood samples were collected for further analysis. Our data shown that IgAN rat model showed marked deterioration of proteinuria together with higher levels of the urine protein:creatinine ratio compared to the normal control. Animals that underwent intermittent exposure to triptolide treatment exhibited significant improvements in the functional parameters without severe side effects. Rats developing IgAN had profound mesangial proliferation and mesangial expansion, intense and diffuse glomerular IgA deposition, while triptolide treatment significantly attenuated it. We also observed that treatment with triptolide significantly decreases serum levels of IL-1β and IL-18, and may exerted anti-inflammatory effects by down-regulating NLRP3 and TLR4 expression. Our study clearly demonstrated that triptolide prevents IgAN progression via an amelioration of inflammasome-mediated proinflammatory cytokine production, thus brought a light of hope for treatment of IgAN.     

Jak3 expression in glomerular epithelia of IgA nephropathy (IgA-N) patients

Jak3 is a member of the Janus kinase family which plays an important role in cytokine signal transduction. Jak3 associates the γ_c chain of receptors for IL-2, IL-4, IL-7, IL-9 and IL-15, and is essential for the signal transduction of these cytokines. We have isolated Jak3 kinase from renal mesangial cells and demonstrated the constitutive expression of Jak3 in glomeruli in vivo. To investigate the physiological and pathological role of Jak3 in glomeruli, we prepared anti-Jak3 antibody and analysed the localization of Jak3 in glomeruli of renal biopsy samples from various nephritis patients and normal subjects. Among 61 nephritis patients and four normal subjects investigated in the present study, Jak3 was selectively localized to glomerular epithelia of IgA-N patients (14/34 cases) and focal glomerulosclerosis patients (1/5 cases), but not detected in minimal changes (n = 6), membranous glomerulonephropathy (n = 7), crescentic glomerulonephritis (n = 4), lupus nephritis patients (n = 5), and normal subjects (n = 4). The intense immunoreactivity for Jak3 is significantly associated with the decrease in creatinine clearance (81.5 ± 10.4 ml/min versus 104.3 ± 29.6 ml/min; P < 0.05, Student’s t-test) and the increase in level of serum creatinine (1.13 ± 0.33 mg/dl versus 0.75 ± 0.23 mg/dl; P < 0.01, Student’s t-test) in IgA-N patients. Furthermore, γ_c chain was concomitantly expressed with Jak3 in glomerular epithelia in vivo and in vitro, suggesting that signal transduction via γ_c-Jak3 cascade may be involved in the pathogenesis of glomerular injury of IgA-N. Taken together with the recent findings that IL-4-secreting T lymphocytes in affected glomeruli injure glomerular epithelium, the responsiveness of glomerular epithelium for IL-4 may be pathologically enhanced in IgA-N.     

Prognostic significance of glomerular and tubulointerstitial morphometry in idiopathic membranous nephropathy

The purpose of our study was to investigate the prognostic value of clinical and pathological, in particular glomerular and tubulointerstitial morphometric variables in idiopathic membranous nephropathy (IMN). We prospectively followed 60 Caucasian patients diagnosed with idiopathic membranous nephropathy for at least 2 years or until primary outcome (≥50% permanent decrease in estimated glomerular filtration rate or death). Glomerular and tubulointerstitial morphometric variables at the time of renal biopsy were analyzed with respect to this outcome. Univariate analysis revealed that significant negative prognostic factors for this outcome were higher cholesterol and smaller albumin concentrations, higher creatinine and maximal 24-h proteinuria, higher grade of nephroangiosclerosis, higher glomerular basement membrane thickness and glomerulopathy index, higher interstitial fibrosis and tubular atrophy percentage and higher injury score. In multivariate analysis, only the maximal 24-h proteinuria and interstitial fibrosis and tubular atrophy percentage were independent predictors of this outcome. The results suggest that morphometric analysis, mainly quantitative measurement of interstitial fibrosis and tubular atrophy percentage, injury score, glomerular basement membrane thickness and glomerulopathy index could be used as an additional method for risk stratification of patients with idiopathic membranous nephropathy.     

HBV serum and renal biopsy markers are associated with the clinicopathological characteristics of HBV-associated nephropathy

Background: Accumulated evidence has shown that hepatitis B virus infection is associated with numerous types of nephropathy but it remains to clarify the different role of HBV markers, either in serum or deposit in kidney, in the pathogenesis of HBV-associated nephropathy. In this study, we investigated the relationship between HBV markers and HBV-associated nephropathy by using multi-linear regression in Chinese patients with HBV-associated membranous nephropathy (MN). Methods: A total of 196 cases of HBV-associated MN, which were diagnosed based on renal biopsy, were collected during the period of January 2000 to December 2009 from our hospital. Serum and renal biopsy HBV markers included HBsAg, anti-HBs, HBeAg, anti-HBe, and anti-HBC. HBV-associated nephropathy was characterized by a panel of clinical manifestations and pathological parameters, which included proteinuria, hematuria, serum creatinine, hypertension, and renal damage in glomeruli, tubules, interstitium, and blood vessels. Multilinear regression was used to analyze the relationship between the HBV markers in serum and renal biopsy and the clinicopathological characteristics of HBV-associated nephropathy. Results: After analysis of the clinical and pathological data in 196 cases of HBV-associated membranous nephropathy, this study revealed that glomerular lesion was marginally associated with serum HBsAg (P = 0.0528), Anti-HBs (P = 0.0978), but significantly associated with the presence of IgA (P = 0.0242), IgG (P < 0.0001) and C3 (P = 0.0064) in renal biopsy. There was no significant association between glomerular lesion and HBV markers in kidney. The presence of crescent and renal tube impairment was not related to HBV markers. The renal fibrosis was significantly related to gender (P = 0.023), age (P = 0.0211), HBsAg (P = 0.0001) and HBcAg (P = 0.0083) and C3 (P = 0.0299) in renal biopsy. Notably, the renal blood vessel impairment was significantly related to systolic Blood Pressure (SBP) (P < 0.0001), diastolic blood pressure (DBP) (P = 0.0002), serum HBsAg (P = 0.0428), serum HBeAg (P = 0.0766), FRA (P = 0.0002), and HBsAg (P = 0.0241) and HBcAg (P = 0.0599) in renal tissues. Also, the renal interstitial infiltration was related to patient age (P = 0.015, SBP (P < 0.0001), DBP (P = 0.0001), C3 (P = 0.0028), FRA (P = 0.0165), HBsAg (P = 0.0016) and HBcAg (P = 0.0203) in kidney biopsy. These results suggest that the major pathological changes in kidneys in HBV patients are related to one or more HBV markers, such as HBsAg, HBeAg, or anti-HBs antibody. Besides, most of the pathological changes in kidneys are related to C3 and FRA in kidney tissues. The clinical markers of nephropathy, such as proteinuria, hematuria and creatine serum levels, were also evaluated for their relationship with HBV markers in serum and kidney tissues. We found proteinuria was marginally related to HBV DNA (P = 0.0537), significantly related to IgA (0.0223). Hematouria was significantly related to IgA (P = 0.0434), IgG (P < 0.0001), and C1q (P = 0.0282). The serum creatine level was related to patient gender (P = 0.0077), SBP (P < 0.0001), DBP (0.0049), IgG (P-0.0006), and C3 (P = 0.0113). These clinical manifestations were not related to HBV markers in either serum or kidney. These results indicate that some of clinical manifestations of nephropathy are related to HBV markers, but the relationship is limited.     

粘附分子选择素在IgA肾病中变化的临床意义

目的：为探讨ＩｇＡ肾病患者血和肾组织中Ｐ选择素必变与疾病的关系。方法：采用酶联免疫吸附法、免疫组化及原位杂交技术检测了４５例ＩｇＡ肾病患者血浆和肾组织中Ｐ选择素含量及表达水平。结果：ＩｇＡ肾病患者血浆Ｐ选择素含量明显高于正常人,其中肾病综合征组和肾功能减退组含量又较肉眼血尿组、尿检异常组和肾炎综合征组显著增高造反素在患者肾组织中广泛表达,其中在Ⅳ级和Ⅴ级ＩｇＡ肾病肾小球中表达水平明显高于Ⅱ级和Ⅲ级     

Protective effects of calcitriol on diabetic nephropathy are mediated by down regulation of TGF-β1 and CIP4 in diabetic nephropathy rat

Objective: To explore the protective effects of calcitriol on diabetic nephropathy by modulating the expressions of transforming growth factor-beta 1 (TGF-β1) and Cdc42 interacting protein-4 (CIP4). Methods: Streptozotocin-induced diabetic nephropathy rats (n=36) were randomly divided into control group (control-H, control-M, control-L) and calcitriol group (calcitriol-H, calcitriol-M, calcitriol-L). The expression of TGF-β1 gradually decreased in control-H, control-M and control-L subgroups by injection of different virus vectors. Peanut oil and calcitriol were given to control and calcitriol group, respectively. The expressions of TGF-β1 and CIP4 in kidney, the pathology, and the renal function and lipid profiles were compared between control and calcitriol treatment groups. Results: In the control group, the higher level of TGF-β1 was associated with more severe glomerular pathology (P<0.05). There is a positive correlation between the expression of CIP4 and TGF-β1. Control-H subgroup had significant more severe kidney disease, higher levels of cholesterol, triglyceride, blood glucose, blood urea nitrogen (BUN) and creatinine (Cr) than control-M and control-L subgroups. After calcitriol treatment, the expression of TGF-β1 and CIP4 were significantly decreased compared to the corresponding control subgroups (all P<0.05). Renal fibrosis and pathological changes were markedly improved. The levels of cholesterol, triglyceride, blood glucose, BUN and Cr were significantly reduced (P<0.05). Conclusion: Calcitriol may protect diabetic nephropathy from fibrosis via inhibition of TGF-β1 and CIP4.     

Expression of prorenin receptor in renal biopsies from patients with IgA nephropathy

Prorenin receptor (PRR) has been implicated in the onset and progression of various renal diseases, though its possible association with immunoglobulin A (IgA) nephropathy remains unclear. In the present study, we tried to clarify expression and pathophysiological significance of PRR in IgA nephropathy. We immunohistochemically assessed PRR levels in renal biopsy specimens from 48 patients with IgA nephropathy and evaluated its relevance to the clinical and pathological features of the disease. PRR was detected mainly in renal tubular cells, which was confirmed at the subcellular level using immunoelectron microscopy. The PRR-positive area (%PRR area) correlated with daily urinary protein, which is known to reflect disease severity (r=0.286, P=0.049). PRR levels were weaker in tubular cells bordering areas of severe interstitial fibrosis, where α-smooth muscle actin-positive myofibroblasts were present. We also used immunohistochemical detection of microtubule-associated protein-1 light chain 3 (LC3) and electron microscopy to assess autophagy, a cytoprotective mechanism downstream of PRR. We noted an apparent coincidence between autophagy activation in tubular cells and PRR expression in the same cells. Taken together, our findings suggest that renal expression of PRR in IgA nephropathy may be a compensatory response slowing disease progression by preventing tubular cell death and subsequent fibrosis through activation of cytoprotective autophagic machinery. Further studies using different type of kidney diseases could draw conclusion if the present finding is a generalized observation beyond IgA nephropathy.     

The role of the tubulointerstitial changes in the prognosis of IgA glomerulonephritis

Summary The authors investigated the tubulointerstitial changes (atrophic tubuli, interstitial fibrosis and round-cell infiltration) by two methods in renal biopsies from 56 patients with IgA glomerulonephritis. A statistically significant correlation was found to exist between the tubulointerstitial changes and serum creatinine level at the time of renal biopsy. A statistically significant correlation was also established between serum creatinine at the end of a period of 5 years of follow-up and tubulointerstitial changes. Their results suggest that severe tubulointerstitial lesions in IgA glomerulonephritis carry a poor prognosis.Abbreviation GN glomerulonephritis     

Tgf-β1 expression as a biomarker of poor prognosis in prostate cancer

OBJECTIVE:

To evaluate the correlation between transforming growth factor beta (TGF-β1) expression and prognosis in prostate cancer.

PATIENTS AND METHODS:

TGF-β1 expression levels were analyzed using the quantitative real-time polymerase chain reaction to amplify RNA that had been isolated from fresh-frozen malignant and benign tissue specimens collected from 89 patients who had clinically localized prostate cancer and had been treated with radical prostatectomy. The control group consisted of 11 patients with benign prostate hyperplasia. The expression levels of TGF-β1 were compared between the groups in terms of Gleason scores, pathological staging, and prostate-specific antigen serum levels.

RESULTS:

In the majority of the tumor samples, TGF-β1 was underexpressed 67.0% of PCa patients. The same expression pattern was identified in benign tissues of patients with prostate cancer. Although most cases exhibited underexpression of TGF-β1, a higher expression level was found in patients with Gleason scores ≥7 when compared to patients with Gleason scores <7 (p = 0.002). Among the 26 cases of TGF-β1 overexpression, 92.3% had poor prognostic features.

CONCLUSIONS:

TGF-β1 was underexpressed in prostate cancers; however, higher expression was observed in tumors with higher Gleason scores, which suggests that TGF-β1 expression may be a useful prognostic marker for prostate cancer. Further studies of clinical specimens are needed to clarify the role of TGF-β1 in prostate carcinogenesis.     

Lowering Blood Pressure Blocks Mesangiolysis and Mesangial Nodules,but Not Tubulointerstitial Injury,in Diabetic eNOS Knockout Mice

Recently, we and others reported that diabetic endothelial nitric oxide synthase knockout (eNOSKO) mice develop advanced glomerular lesions that include mesangiolysis and nodular lesions. Interestingly, insulin treatment lowered blood pressure and prevented renal lesions, raising the question as to whether these beneficial effects of insulin were due to its ability to lower either high glucose levels or high blood pressure. We, therefore, examined the effect of lowering blood pressure using hydralazine in this diabetic eNOSKO mouse model. Hydralazine treatment significantly blocked the development of mesangiolysis and microaneurysms, whereas tubulointerstitial injury was not prevented in these mice. Additionally, hydralazine did not reduce expression levels of either tubulointerstitial thrombospondin-1 or transforming growth factor-β despite controlling blood pressure. On the other hand, the critical role of high glucose levels on the development of tubulointerstitial injury was suggested by the observation that serum glucose levels were correlated with tubulointerstitial injury, as well as with the expression levels of both transforming growth factor-β and thrombospondin-1. Importantly, controlling blood glucose with insulin completely blocked tubulointerstitial injury in diabetic eNOSKO mice. These data suggest that glomerular injury is dependent on systemic blood pressure, whereas hyperglycemia may have a more important role in tubulointerstitial injury, possibly due to the stimulation of the thrombospondin-1-transforming growth factor-β pathway in diabetic eNOSKO mice. This study could provide insights into the pathogenesis of advanced diabetic nephropathy in the presence of endothelial dysfunction.Diabetic nephropathy is pathologically characterized by glomerular hypertrophy, glomerular basement membrane thickening and mesangial expansion, and later by mesangiolysis and Kimmelstiel-Wilson nodules.^1,2 While numerous diabetic models have been able to reproduce the early mesangial changes, until recently, a model of advanced diabetic nephropathy has been lacking. Recently, we and others have reported that diabetic endothelial nitric oxide synthase knockout (eNOSKO) mice develop severe glomerular lesions, which resemble advanced lesions of human diabetic nephropathy.^1,2 Diabetic eNOSKO mice exhibit mesangiolysis, Kimmelstiel-Wilson-like nodules and glomerular capillary microaneurysms. Diabetic eNOSKO mice also develop worsening hypertension in association with renal injury.^1,2 Importantly, insulin treatment can control blood glucose, significantly reduce blood pressure, and prevent glomerular injury. This raises the question as to whether the beneficial effects of insulin on renal injury are due to controlling blood glucose and/or lowering blood pressure.Blood pressure control is considered a key recommendation for preventing the progression of diabetic renal disease.³ However, the role of blood pressure control in the presence of endothelial dysfunction is not well understood. For example, Chen et al have examined the role of hypertension in apo E/eNOS double knockout mice and found that lowering blood pressure with hydralazine did not prevent the development of atherosclerosis and aneurysms.⁴Given this finding, we examined if lowering in blood pressure through the use of hydralazine could block the development of advanced diabetic nephropathy, including glomerular and tubulointerstitial lesions, in the presence of endothelial dysfunction. In addition, we also evaluated the role of blood glucose on tubulointerstitial injury in this model.