Sodium bicarbonate treatment reduces renal injury, renal production of transforming growth factor-beta, and urinary transforming growth factor-beta excretion in rats with doxorubicin-induced nephropathy

StemPanTox: A fast and wide-target drug assessment system for tailor-made safety evaluations using personalized iPS cells

An alternative model that reliably predicts human-specific toxicity is necessary because the translatability of effects on animal models for human disease is limited to context. Previously, we developed a method that accurately predicts developmental toxicity based on the gene networks of undifferentiated human embryonic stem (ES) cells. Here, we advanced this method to predict adult toxicities of 24 chemicals in six categories (neurotoxins, cardiotoxins, hepatotoxins, two types of nephrotoxins, and non-genotoxic carcinogens) and achieved high predictability (AUC = 0.90-1.00) in all categories. Moreover, we screened for an induced pluripotent stem (iPS) cell line to predict the toxicities based on the gene networks of iPS cells using transfer learning of the gene networks of ES cells, and predicted toxicities in four categories (neurotoxins, hepatotoxins, glomerular nephrotoxins, and non-genotoxic carcinogens) with high performance (AUC = 0.82-0.99). This method holds promise for tailor-made safety evaluations using personalized iPS cells.

Evaluation of the protective effect of edaravone on doxorubicin nephrotoxicity by [99mTc]DMSA renal scintigraphy and biochemical methods

To evaluate the nephroprotective effect of edaravone on doxorubicin-induced nephrotoxicity. In this experimental study, twenty-eight Wistar male rats were used. The rats were separated into 4 groups (n = 7); group І (control), rats were treated with saline (4 ml/kg) and group ІІ (doxorubicin), nephrotoxicity was induced by three doses of 18 mg/kg/i.p. doxorubicin, at a 24-h interval on the 12th, 13th, and 14th days. Group ІІІ (edaravone), rats were treated with edaravone (30 mg/kg/for 14 days), and group ІV (edaravone + doxorubicin), rats were treated with edaravone (30 mg/kg/for 14 days) and doxorubicin were injected (18 mg/kg/for 3 days; at a 24-h interval on the 12th, 13th, and 14th days). On the 15th day of the experiment, technetium-99m-labeled dimercaptosuccinic acid ([^99mTc]DMSA) uptake was obtained in both kidneys and biochemical parameters from serum and kidney tissue were measured. Doxorubicin led to nephrotoxicity through elevation of serum blood urea nitrogen (BUN), creatinine and tumor necrosis factor-α (TNF-α), nitric oxide (NO), and interleukin-6 (IL-6) in kidney tissue and decreased [^99mTc]DMSA uptake level in the kidney when compared with control group (p < 0.01). Pretreatment edaravone significantly decreased BUN and creatinine, also kidney tissue TNF-α, IL-6, NO, and increased [^99mTc]DMSA uptake level compared with the doxorubicin. Edaravone has a significant nephroprotective effect through the attenuation of oxidative stress and inflammatory markers during doxorubicin-induced nephrotoxicity in rats.

Ginkgo Biloba Extract Alleviates Methotrexate-Induced Renal Injury: New Impact on PI3K/Akt/mTOR Signaling and MALAT1 Expression

Renal injury induced by the chemotherapeutic agent methotrexate (MTX) is a serious adverse effect that has limited its use in the treatment of various clinical conditions. The antioxidant activity of Ginkgo biloba extract (GB) was reported to mitigate renal injury induced by MTX. Our research was conducted to examine the nephroprotective role of GB versus MTX-induced renal injury for the first time through its impact on the regulation of phosphatidylinositol 3-kinase/protein kinase B/ mammalian target of rapamycin (PI3K/Akt/mTOR) signaling together with the renal level of TGF-β mRNA and long non-coding RNA-metastasis-associated lung adenocarcinoma transcript-1 (MALAT1) expression. A group of adult rats was intraperitoneally (ip) injected with MTX 20 mg/kg as a single dose to induce kidney injury (MTX group). The other group of rats was orally administered with GB 60 mg/kg every day for 10 days (GB+ MTX group). The MTX increased the serum creatinine and urea levels, renal TGF-β mRNA and MALAT1 expression, in addition to dysregulation of the PI3K/Akt/mTOR signaling when compared with normal control rats that received saline only (NC group). Moreover, renal damage was reported histopathologically in the MTX group. The GB ameliorated the renal injury induced by MTX and reversed the changes of these biochemical analyses. The involvement of PI3K/Akt/mTOR signaling and downregulation of TGF-β mRNA and MALAT1 renal expressions were firstly reported in the nephroprotective molecular mechanism of GB versus MTX-induced renal injury.

Imbalance of Pro- and Anti-Angiogenic Factors Due to Maternal Vitamin D Deficiency Causes Renal Microvasculature Alterations Affecting the Adult Kidney Function

Vitamin D (Vit.D) is involved in cellular proliferation and differentiation and regulation of the renin gene, which are important aspects of nephrogenesis and quiescence of renal health in adulthood. This study evaluated the angiogenic mechanisms involved in long term renal disturbances induced by Vit.D deficiency persistent in adulthood in rats. First-generation male Hannover offspring from mothers fed either a control diet (control group, CG) or Vit.D-deficient diet (Vit.D- group) were evaluated. Systolic blood pressure (SBP) was measured monthly during the first 6 months after birth, and blood and urine samples were collected to evaluate renal function. Nitric oxide (NO), angiotensin II (ANGII), parathyroid hormone (PTH), calcium, and Vit.D were measured. The kidneys were then removed for morphometric, NO, immunohistochemical, and Western blot studies. We evaluated the expression of vascular growth factor (VEGF) and angiopoietins 1 and 2 and their receptors since this intrinsic renal axis is responsible for endothelial quiescence. Compared to CG, the Vit.D- group presented higher SBP, ANG II plasma levels, renin expression, and AT1 receptor expression levels. Capillary rarefaction was observed, as well as an imbalance between pro- and anti-angiogenic factors. Collectively, the present findings support the role of Vit.D for maintaining the integrity of renal microcirculation.

Effect of perioperative sodium bicarbonate administration on renal function following cardiac surgery for infective endocarditis: a randomized, placebo-controlled trial

Background

Patients with infective endocarditis (IE) have an elevated risk of renal dysfunction because of extensive systemic inflammation and use of nephrotoxic antibiotics. In this randomized, placebo-controlled trial, we investigated whether perioperative sodium bicarbonate administration could attenuate postoperative renal dysfunction in patients with IE undergoing cardiac surgery.

Methods

Seventy patients randomly received sodium chloride (n = 35) or sodium bicarbonate (n = 35). Sodium bicarbonate was administered as a 0.5 mmol/kg loading dose for 1 h commencing with anesthetic induction, followed by a 0.15 mmol/kg/h infusion for 23 h. The primary outcome was peak serum creatinine (SCr) level during the first 48 h postoperatively. The incidence of acute kidney injury, SCr level, estimated glomerular filtration rate, and major morbidity endpoints were assessed postoperatively.

Results

The peak SCr during the first 48 h postoperatively (bicarbonate vs. control: 1.01 (0.74, 1.37) mg/dl vs. 0.88 (0.76, 1.27) mg/dl, P = 0.474) and the incidence of acute kidney injury (bicarbonate vs. control: 29% vs. 23%, P = 0.584) were similar in both groups. The postoperative increase in SCr above baseline was greater in the bicarbonate group than in the control group on postoperative day 2 (0.21 (0.07, 0.33) mg/dl vs. 0.06 (0.00, 0.23) mg/dl, P = 0.028) and postoperative day 5 (0.23 (0.08, 0.36) mg/dl vs. 0.06 (0.00, 0.23) mg/dl, P = 0.017).

Conclusions

Perioperative sodium bicarbonate administration had no favorable impact on postoperative renal function and outcomes in patients with IE undergoing cardiac surgery. Instead, it was associated with possibly harmful renal effects, illustrated by a greater increase in SCr postoperatively, compared to control.

Trial registration

ClinicalTrials.gov, NCT01920126. Registered on 31 July 2013.

Electronic supplementary material

The online version of this article (doi:10.1186/s13054-016-1591-z) contains supplementary material, which is available to authorized users.

The role of oxidative stress in renal injury induced in rats by losartan exposure during lactation

INTRODUCTION

Rats exposed to angiotensin II (AII) receptor antagonists during lactation present progressive disturbances in renal development that lead to progressive alterations in renal function and structure. This study evaluates the role of oxidative stress in the renal changes induced by exposure to losartan, a type 1 AII receptor antagonist, in rats during lactation.

MATERIALS AND METHODS

Male Wistar pups were divided into: Control, pups of dams that received 2% sucrose solution; Control-tempol, pups of dams that received tempol (0.34 g/l), a superoxide dismutase mimetic compound; Losartan, pups of dams that received losartan (100 mg/kg/day), and Losartan-tempol, pups of dams that received losartan and tempol. Losartan and/or tempol were administered during lactation. Blood and urine samples were collected at 21 or 60 days, and the kidneys were removed.

RESULTS

Losartan-treated pups exhibited disturbances in renal function and structure that persisted into adulthood. Tempol treatment reduced oxidative stress and attenuated the changes induced by losartan in the glomerular filtration rate, desmin expression at the glomerular edge, vimentin in tubular cells, as well as apoptosis and inflammatory infiltration in the renal cortex.

CONCLUSION

Oxidative stress contributes at least in part to the renal injury observed in pups exposed to losartan during lactation.

Effects of amlodipine on TGF-β-induced Smad2, 4 expressions in adriamycin toxicity of rat mesangial cells

Transforming growth factor-β (TGF-β) is closely associated with progressive renal fibrosis. A central component of TGF-β-stimulated mesangial cell fibrogenesis is the TGF-β family-specific Smad signal transduction pathway. This study investigated the expression of TGF-β-receptor--activated Smad2, its common partner Smad4, and the phosphorylated Smad2 (p-Smad2) in adriamycin-induced toxicity of cultured rat mesangial cells. This in vitro study showed that amlodipine (10(-9) to 10(-5) mol/l) had no effect on the toxicity of rat mesangial cells induced by adriamycin in the absence of TGF-β1. However, amlodipine (10(-7) to 10(-5) mol/l) reduced the toxicity of rat mesangial cells induced by TGF-β1 in the absence of adriamycin; moreover, amlodipine (10(-8) to 10(-5) mol/l) significantly reduced adriamycin-induced cytotoxicity when it was given in combination with TGF-β1; amlodipine (10(-6), 10(-5) mol/l) had no effect on Smad2 mRNA and protein expression induced by adriamycin + TGF-β1, but it (10(-6), 10(-5) mol/l) dramatically inhibited the down-regulation of p-Smad2 protein expression as well as Smad4 mRNA and protein expression induced by adriamycin + TGF-β1 in rat mesangial cells. Present study shows that amlodipine exerts a significant inhibition on adriamycin-induced toxicity in rat mesangial cells by affecting the expression of TGF-β/Smad signaling intermediates p-Smad2 and Smad4.

Sodium bicarbonate plus N-acetylcysteine prophylaxis: a meta-analysis

OBJECTIVES

We sought to conduct a meta-analysis to compare N-acetylcysteine (NAC) in combination with sodium bicarbonate (NaHCO(3)) for the prevention of contrast-induced acute kidney injury (AKI).

BACKGROUND

Contrast-induced AKI is a serious consequence of cardiac catheterizations and percutaneous coronary interventions (PCI). Despite recent supporting evidence for combination therapy, not enough has been done to prevent the occurrence of contrast-induced AKI prophylactically.

METHODS

Published randomized controlled trial data were collected from OVID/PubMed, Web of Science, and conference abstracts. The outcome of interest was contrast-induced AKI, defined as a >or=25% or >or=0.5 mg/dl increase in serum creatinine from baseline. Secondary outcome was renal failure requiring dialysis.

RESULTS

Ten randomized controlled trials met our criteria. Combination treatment of NAC with intravenous NaHCO(3) reduced contrast-induced AKI by 35% (relative risk: 0.65; 95% confidence interval: 0.40 to 1.05). However, the combination of N-acetylcysteine plus NaHCO(3) did not significantly reduce renal failure requiring dialysis (relative risk: 0.47; 95% confidence interval: 0.16 to 1.41).

CONCLUSIONS

Combination prophylaxis with NAC and NaHCO(3) substantially reduced the occurrence of contrast-induced AKI overall but not dialysis-dependent renal failure. Combination prophylaxis should be incorporated for all high-risk patients (emergent cases or patients with chronic kidney disease) and should be strongly considered for all interventional radio-contrast procedures.

Sodium bicarbonate for the prevention of contrast-induced nephropathy: a meta-analysis of 17 randomized trials

BACKGROUND

Contrast-induced nephropathy (CIN) is a common cause of acute kidney injury. Several preventive therapies for this injury have been tested; however, there is still no consensus on the optimal protocol.

METHODS

We performed a systematic search of the National Library of Medicine and the Cochrane Library databases from January 1985 to November 2008 to identify randomized controlled studies examining sodium bicarbonate as a preventive measure for CIN in humans. We also reviewed conference abstracts from cardiology nephrology and radiology meetings from 2004 to 2008. A change in serum creatinine levels defined by an absolute (>or=0.5 mg/dl) or percentage (>or=25%) increase in the serum creatinine level is defined as CIN. The primary outcome measure was the incidence of CIN, and the secondary outcome measures were: change in serum creatinine from baseline, requirement for renal replacement therapy and death.

RESULTS

Seventeen randomized controlled trials have investigated the role of sodium bicarbonate for prophylaxis of CIN. The overall incidence of CIN was 11.3%. Using the results from all 17 studies that compared bicarbonate versus saline, the pooled relative risk of developing CIN was 0.54 (95% CI, 0.36-0.83) in the intervention arm, indicating a significant benefit from sodium bicarbonate. The pooled relative risk of CIN was 0.57 (95% CI, 0.35-0.95) when we analyzed for the studies that compared the effects sodium bicarbonate to NAC on development of CIN. There was no difference in the rates of requirement for renal replacement therapy and death.

CONCLUSIONS

The use of sodium bicarbonate appears to reduce the incidence of CIN when compared to other preventive strategies for CIN without a significant difference in the requirement of renal replacement therapy and mortality. There are study heterogeneity and publication biases. Further adequately powered randomized controlled studies are needed to determine whether sodium bicarbonate will reduce the clinically meaningful outcomes (e.g., need for dialysis or death) and optimal hydration strategy in high-risk patients.

Comparison of usefulness of sodium bicarbonate versus sodium chloride to prevent contrast-induced nephropathy in patients undergoing an emergent coronary procedure

In the case of an emergency coronary procedure where the risk of contrast-induced nephropathy is especially high, there are few reliable methods to attenuate renal injury. We examined the efficacy of sodium bicarbonate for the prevention of contrast-induced nephropathy in patients undergoing an emergency coronary procedure. We enrolled 59 patients who were scheduled to undergo an emergency coronary angiography or intervention. These patients were randomized to receive a 154-mEq/L infusion of sodium bicarbonate (n = 30) or sodium chloride (n = 29), as a bolus of 3 ml/kg/hour for 1 hour before the administration of contrast, followed by an infusion of 1 ml/kg/hour for 6 hours during and after the procedure. In the sodium bicarbonate group, serum creatinine concentration remained unchanged within 2 days of contrast administration (1.31 +/- 0.52 to 1.31 +/- 0.59 mg/dl), whereas it increased in the sodium chloride group (1.32 +/- 0.65 to 1.52 +/- 0.92 mg/dl, p = 0.01). The incidence of contrast-induced nephropathy (an increase >0.5 mg/dl or >25% in serum creatinine concentration within 2 days of contrast) was significantly lower in the sodium bicarbonate group than in the sodium chloride group (7% vs 35%, p = 0.01, risk ratio 0.19, 95% confidence interval 0.046 to 0.80). In conclusion, hydration with sodium bicarbonate is more effective than with sodium chloride for the prevention of contrast-induced nephropathy in patients undergoing an emergency coronary procedure.

Renal function during and after treatment for acute lymphoblastic leukemia in children

Renal function tests (cystatin C, serum and urine creatinine, creatinine clearance, serum and urine beta(2)-microglobulin, microalbuminuria, osmolality) were performed in 21 children at the diagnosis and during the treatment for acute lymphoblastic leukemia (ALL) (group I) and in 37 children (group II) treated for ALL 3.9+/-3.7 years before the study. The results were compared to 20 healthy children. Mean values of renal tests were in normal range at all points of analysis in groups I and II compared to the control group. Transitory higher cystatin C values (but in normal range) were observed after methotrexate administration and after the end of treatment. Deteriorated renal function was observed in one child during the treatment (after each protocol) and in five children treated previously for ALL. In conclusion, combined treatment for ALL is not associated with severe or long-term impairment of renal function.

Management of Glomerular Proteinuria: A Commentary

ABSTRACT. It is widely accepted that proteinuria reduction is an appropriate therapeutic goal in chronic proteinuric kidney disease. Based on large randomized controlled clinical trials (RCT), ACE inhibitor (ACEI) and angiotensin receptor blocker (ARB) therapy have emerged as the most important antiproteinuric and renal protective interventions. However, there are numerous other interventions that have been shown to be antiproteinuric and, therefore, likely to be renoprotective. Unfortunately testing each of these antiproteinuric therapies in RCT is not feasible. The nephrologist has two choices: restrict antiproteinuric therapies to those shown to be effective in RCT or expand the use of antiproteinuric therapies to include those that, although unproven, are plausibly effective and prudent to use. The goal of this work is to provide the documentation needed for the nephrologist to choose between these strategies. This work describes 25 separate interventions that are either antiproteinuric or may block injurious mechanisms of proteinuria. Each intervention is assigned a level of recommendation (Level 1 is the highest; Level 3 is the lowest) according to the strength of the evidence supporting its antiproteinuric and renoprotective efficacy. Pathophysiologic mechanisms possibly involved are also discussed. The number of interventions at each level of recommendation are: Level 1, n = 7; Level 2, n = 9; Level 3, n = 9. Our experience indicates that we can achieve in most patients the majority of Level 1 and many of the Level 2 and 3 recommendations. We suggest that, until better information becomes available, a broad-based, multiple-risk factor intervention to reduce proteinuria can be justified in those with progressive nephropathies. This work is intended primarily for clinical nephrologists; therefore, each antiproteinuria intervention is described in practical detail.

Role of proteinuria in the regulation of renal renin-angiotensin system components in unilateral proteinuric rats

Renin-angiotensin system (RAS) overactivity has been implied in progressive renal function loss. We investigated whether changes in the renal expression of RAS components are specifically associated with the proteinuric kidney. Unilateral adriamycin-induced proteinuria was obtained by clamping the left renal artery before injection of adriamycin. In control animals, both left and right renal arteries were clamped. Twelve weeks later, mRNA expression of RAS components was determined in both kidneys. In the affected and non-affected kidney of the unilateral proteinuric rat, we demonstrate up-regulation of angiotensin- converting enzyme (ACE) mRNA (213%+22 and 188%+24 of controls, respectively), up-regulation of transforming growth factor beta (TGF-beta) mRNA (956%+229 and 418%+56) and down-regulation of angiotensin type 2 receptor (AT2-R) mRNA (24%+5 and 20%+5). The expression of angiotensin type 1 receptor (AT1-R) mRNA and inositol 1,4,5- trisphosphate receptor type I (IP3R-I) mRNA were unchanged. In conclusion, renal expression of ACE, AT2-R, and AT1-R mRNA is not mediated by protein leakage. Local intrarenal protein leakage did influence renal TGF-beta mRNA expression.

Gene transfer of truncated IkappaBalpha prevents tubulointerstitial injury

BACKGROUND

Severe proteinuria not only indicates the presence of progressive glomerular disease, but also causes tubular epithelial cells to produce inflammatory mediators leading to tubulointerstitial (TI) injury. We investigated the role of nuclear factor-kappaB (NF-kappaB) in tubular epithelial cells in the development of proteinuria-induced TI injury.

METHODS

To specifically inhibit NF-kappaB activation, a recombinant adenovirus vector expressing a truncated form of IkappaBalpha (AdexIkappaBDeltaN) was injected into renal arteries of protein-overloaded rats, a model of TI injury characterized by infiltration of mononuclear cells and fibrosis.

RESULTS

Activation of NF-kappaB in the renal cortex, observed in protein-overloaded rats treated with a control vector, recombinant lacZ adenovirus, was prevented in AdexIkappaBDeltaN-injected rats. Microscopic examination revealed AdexIkappaBDeltaN treatment to markedly attenuate proteinuria-induced TI injury. Increased immunostaining of vascular cell adhesion molecule-1, transforming growth factor-beta, and fibronectin in TI lesions also was suppressed by AdexIkappaBDeltaN injection.

CONCLUSIONS

These findings provide evidence of the critical role of NF-kappaB activation in TI injury and suggest the therapeutic potential of adenovirus-mediated IkappaBDeltaN gene transfer into the kidney as a means of interrupting the process of TI damage.

Effect of enalapril and losartan on the events that precede diabetic nephropathy in rats

BACKGROUND

Mesangial cell proliferation, phenotype change, and increased transforming growth factor-beta (TGF-beta) precede mesangial expansion in diabetic rats. Experiments using mesangial cell culture have shown that angiotensin II increases TGF-beta production by these cells. The aim of the present study was to investigate the effect of enalapril and losartan on the events that precede diabetic nephropathy in rats. It was also analyzed if the determination of urinary TGF-beta could be a mean for the evaluation of therapeutic efficacy in this disease.

METHODS

Eighty-two female Wistar rats were made diabetic by intravenous injection of streptozotocin diluted in citrate buffer, and citrate buffer alone was injected into the control group (N = 34). Ten days later, the right kidney was removed. Thirty diabetic rats were treated with enalapril, DMN + E, in drinking water (20 mg/L) and 24 with losartan, DMN + L (50 mg/L). Urinary TGF-beta was determined 90 days after STZ or buffer injection, the animals were killed, and the kidneys were removed for histological and immunohistochemical studies.

RESULTS

The immunostaining for TGF-beta and fibronectin in the cortical tubulointerstitium and glomeruli was higher in untreated diabetic rats (p < 0.001). Treatment with enalapril or losartan reduced this increase. The urinary TGF-beta excretion (pg/mg urinary creatinine) was 48.6 +/- 5.9 in control animals, 603.9 +/- 80.41 in untreated diabetic rats, 279.3 +/- 47.0 in diabetic rats treated with enalapril, and 243.7 +/- 40.0 in rats treated with losartan.

CONCLUSIONS

We concluded that enalapril or losartan treatment can modify events that precede diabetic nephropathy by reducing TGF-beta and fibronectin expression in glomeruli and tubulointerstitium as well as urinary TGF-beta content.

Classes, activity and chronicity indices, and alpha-smooth muscle actin expression as prognostic parameters in lupus nephritis outcome

Renal biopsies of 86 patients with lupus nephritis were assessed according to the WHO classification, and according to activity and chronicity indices. The aim of the present study was to correlate clinical, and histological features (WHO class, activity and chronicity indices, and alpha-SM actin expression) with the progression of lupus nephritis, and identify the pathological role of alpha-SM actin in lupus nephritis. The median follow-up time was 75.5 +/- 57.3 months. Two patients were grouped as WHO class IIa lupus nephritis, eight patients as class IIb, 16 patients as class III, 25 patients as class IV, 15 patients as class V, and 19 patients as mixed pattern lupus nephritis. Sex, age, race, and the alpha-SM actin expression in glomeruli and tubulo-interstitial area in WHO class III and IV showed no correlation with clinical follow-up outcome of lupus nephritis. Unfavorable clinical outcome of lupus nephritis was correlated with WHO class IV compared to the other classes, and with the chronicity index in WHO class III patients.

Steroid therapy and urinary transforming growth factor-beta1 in IgA nephropathy

Transforming growth factor-beta1 (TGF-beta1) has an important role in the pathogenesis of glomerular damage by influencing matrix metabolism. An association of TGF-beta1 with glomerulosclerosis and interstitial fibrosis has been shown in various renal diseases, suggesting that TGF-beta1 may serve as a diagnostic marker of glomerular diseases. The aim of this study is to determine the usefulness of urinary TGF-beta1 values to monitor therapeutic effects of steroids in patients with immunoglobulin A (IgA) nephropathy. Concentrations and activation rates of TGF-beta1 (mature/total) were determined in urine of patients with renal diseases by means of a double-antibody enzyme immunoassay. The urinary TGF-beta1 level before steroid therapy was compared with renal histological characteristics, creatinine clearance, and proteinuria in patients with a variety of renal diseases. Urinary excretion of total and mature TGF-beta1 was significantly greater in patients with crescentic glomerulonephritis and IgA nephropathy than in healthy controls, whereas the activation rate of urinary TGF-beta1 was similar among patients with other renal diseases. Urinary TGF-beta1 excretion at the time of renal biopsy significantly correlated with the degree of crescent formation in patients with IgA nephropathy, but not in those with glomerular sclerosis or tubulointerstitial fibrosis. Urinary excretion of total and mature TGF-beta1 was reduced in patients with IgA nephropathy after treatment with prednisolone (0.8 mg/kg/d) for 1 month. The activation rate of urinary TGF-beta1 also decreased significantly after steroid therapy. Urinary TGF-beta1 values therefore may be useful to assess disease activity or the effects of steroid therapy in patients with IgA nephropathy.

Tubular cell lesion, albuminuria, and renal albumin handling in rats treated with adriamycin

Several lines of evidence have suggested that renal handling of proteins in rats with several nephropathies may contribute to the tubulointerstitial damage observed in these animals. It has been suggested that proteins filtered by the glomeruli may be toxic for tubule cells. The aim of this study was to investigate the relationship between albuminuria and tubular lesions observed in rats during the first two weeks after treatment with adriamycin (AD). Thirty female Wistar rats were injected intravenously with adriamycin at the dose of 3.5 (17 rats) or 5mg/kg body weight (13 rats), and 7 were injected with 0.15 M NaCl (control group). Seven days later, we replaced drinking water with a 0.10 M sodium bicarbonate solution for 6 of the animals injected with 5 mg/kg adriamycin (group AD-B). Urine samples were collected before and 7 and 15 days after treatment to quantify albumin. The rats were killed 7 and 18 days after the injections, and the kidneys removed for immunohistochemical study. We observed a significant increase in urinary albumin excretion 15 days after AD injection (3.5 mg/kg), but not 7 days after AD. However, in the animals injected with 5.0 mg/kg AD (group AD-5) the increase in albuminuria was observed as early as on day 7. The immunohistochemical studies showed increased vimentin and albumin immunoreaction in the tubular cells of the renal cortex from the kidneys of rats injected with 3.5 mg/kg (group AD-3) only 18 days after treatment (p < 0.05), whereas in the animals treated with 5 mg/kg AD these immunohistochemical alterations were more intense. However, treatment with sodium bicarbonate attenuated the tubular lesions and reduced albumin reabsorption in adriamycin-treated rats. In conclusion, these experiments showed a relationship between albuminuria and tubular lesions in adriamycin-treated rats.

Alpha-smooth muscle actin and proliferating cell nuclear antigen expression in focal segmental glomerulosclerosis: functional and structural parameters of renal disease progression

The aim of the present study was to investigate the expression of alpha-smooth muscle actin (alpha-SM-actin) and proliferating cell nuclear antigen (PCNA) in renal cortex from patients with focal segmental glomerulosclerosis (FSGS) and their correlations with parameters of renal disease progression. We analyzed renal biopsies from 41 patients with idiopathic FSGS and from 14 control individuals. The alpha-SM-actin immunoreaction was evaluated using a score that reflected the changes in the extent and intensity of staining in the glomerular or cortical area. The PCNA reaction was quantified by counting the labeled cells of the glomeruli or renal cortex. The results, reported as median +/- percentile (25th; 75th), showed that the alpha-SM-actin scores in the glomeruli and tubulointerstitium from the renal cortex were 2.0 (2.0; 4.0) and 3.0 (3.0; 4.0), respectively, in patients with FSGS, and 0.5 (0.0; 1.0) and 0.0 (0.0; 0.5) in the controls. The number of PCNA-positive cells per glomerulus and graded field of tubulointerstitium from the renal cortex was 0.2 (0.0; 0.4) and 1.1 (0.3; 2.2), respectively, for patients with FSGS, and 0.0 (0.0; 0.5) and 0.0 (0.0; 0.0) for controls. The present data showed an increase of alpha-SM-actin and PCNA expression in glomeruli and renal cortex from FSGS patients. The extent of immunoreaction for alpha-SM-actin in the tubulointerstitial area was correlated with the intensity of proteinuria. However, there was no correlation between the kidney expression of these proteins and the reciprocal of plasma creatinine level or renal fibrosis. These findings suggest that the immunohistochemical alterations may be reversible.