[Expression of interleukin-6 in rat model of doxorubicin-induced nephropathy]

OBJECTIVE

The pathogenesis of minimal change nephrotic syndrome (MCNS) remains unclear. This study aimed to investigate the expression of interleukin-6 (IL-6) in rats with doxorubicin-induced nephropathy and its possible roles in the pathogenesis of MCNS.

METHODS

Eighty-three male Wistar rats were randomly assigned into a control group (n=32) and a nephropathy group (n=51). Nephropathy was induced by a single tail vein injection of doxorubicin (5 mg/kg). The control group was injected with normal saline. Twenty-four-hour urinary protein excretion was measured 7, 14, 28 and 42 days after doxorubicin injection. IL-6 expression in urine and renal tissues was determined using ELISA 7, 14, 28 and 42 days after doxorubicin injection.

RESULTS

The urinary protein excretion increased significantly in the nephropathy group 7, 14, 28 and 42 days after doxorubicin injection compared with that in the control group (P<0.01). IL-6 expression in urine and renal tissues increased significantly 7, 14, 28 and 42 days after doxorubicin injection compared with that in the control group (P<0.01). IL-6 expression in urine and renal tissues was positively correlated with 24-hour urinary protein excretion in the nephropathy group (r=0.794, P<0.01; r= 0.870, P<0.01). IL-6 expression in urine was positively correlated with that in renal tissues (r=0.739, P<0.01).

CONCLUSIONS

IL-6 expression in the urine and renal tissues is increased in MCNS rats. IL-6 might play an important role in the pathogenesis of MCNS.

[Bone mesenchymal stem cell transplantation repairs glomerular podocytes in rats with puromycin aminonucleoside-induced nephrosis]

OBJECTIVE

To investigate the effect of bone mesenchymal stem cell (BMSC) transplantation on repair of glomerular podocytes and on the Nephrin expression in rats with puromycin aminonucleoside (PAN) -induced nephrosis.

METHODS

Forty-five Sprague-Dawley rats were randomly divided into three groups (n=15 each): a nephrosis model group that received a single intraperitoneal injection of PAN (0.15 mg/g); a BMSC transplantation group that received a single intraperitoneal injection of PAN (0.15 mg/g) followed by BMSC transfusion; a control group that received a single intraperitoneal injection of normal saline. Ten days after injection, the rats were sacrificed. The 24 hrs urinary protein content and serum albumin and cholesterol levels were measured 24 hrs before sacrifice. Changes of glomerular podocytes were observed under an electron microscope. Brdu labeled positive cells in kidneys were measured by immunohistochemical technology. RT-PCR and Western blot were used to assess the expression of mRNA and protein of Nephrin.

RESULTS

In the nephrosis model group, urinary protein and blood cholesterol contents increased, plasma albumin content decreased compared with those in the control group. Extensive fusion of podocyte foot processes was observed in the nephrosis model group. The BMSC transplantation group had decreased urinary protein and blood cholesterol contents and increased plasma albumin content compared with the nephrosis model group. Fusion of podocyte foot processes was also improved. Brdu labeled positive cells were seen in kidneys in the BMSC transplantation group, but not in the nephrosis model and the control groups. Nephrin mRNA and protein expression decreased significantly in the nephrosis model group compared with that in the control group. The BMSC transplantation group had increased Nephrin mRNA and protein expression compared with the nephrosis model group.

CONCLUSIONS

BMSCs can repair glomerular podocytes in PAN-induced nephrosis rats, and the changes of Nephrin expression may be involved in the process.

Fatal renal vasculitis and minimal change glomerulonephritis complicating treatment with penicillamine. Report on two cases

Two cases with different and not previously described fatal renal complications during treatment with penicillamine are reported. A man with seronegative rheumatoid arthritis with features of systemic lupus erythematosus was treated with penicillamine for six months and developed a mild membranous glomerulonephritis and a severe renal vasculitis leading to uremia and death. A woman with primary biliary cirrhosis was treated with penicillamine for nine months and developed a nephrotic syndrome, the renal biopsy showing minimal change glomerulonephritis. The nephrotic syndrome responded to prednisone but the patient died, probably from septicemia. Penicillamine may thus cause glomerular damage without deposition of immune complexes. A restricted use of the drug is recommended.

Nephrotic syndrome associated with interferon-beta-1b therapy for multiple sclerosis

A 43-year-old woman with multiple sclerosis (MS) had nephrotic syndrome 21 months after starting treatment with interferon (IFN)-beta-1b (subcutaneous administration). She had taken no drug except for the IFN-beta-1b. Because nephrotic syndrome may be induced by IFN therapy, the IFN was stopped. Percutaneous renal biopsy revealed that she had minimal change nephrotic syndrome. As nephrotic-range proteinuria, hypoalbuminemia, and general edema were worsening even 2 weeks after cessation of the drug, oral corticosteroid therapy (prednisolone 40 mg/day) was started. The nephrotic syndrome was treated successfully with prednisolone. The dosage of prednisolone was tapered, without a relapse, and then the corticosteroid therapy was stopped. IFN-beta-1b therapy was then resumed, and the patient is in remission for both nephrotic syndrome and MS. Though proteinuria and nephrotic syndrome is a rare adverse effect of IFN-beta-1b therapy, physicians treating MS patients with this agent should pay careful attention to new clinical symptoms and laboratory findings.

Minimal change disease following exposure to mercury-containing skin lightening cream

A 34-year-old woman developed nephrotic syndrome after using a skin lightening cream that contained an extremely high level of mercury. Blood and urine mercury levels were elevated and a renal biopsy revealed minimal change disease. Membranous nephropathy was excluded using immunofluorescence and electron microscopy. Her proteinuria remitted 9 months after she stopped using the cosmetic cream. This is the first reported case in the English literature of proven minimal change disease secondary to mercury exposure. It is important that mercury poisoning due to cosmetic cream is considered in the differential diagnoses for any woman who presents with nephrotic syndrome.

Drug-induced glomerulopathies

Normal renal function depends upon an intact glomerular apparatus. Many drugs and chemicals are capable of damaging the glomerulus, causing its increased permeability to large molecules. Glomerular lesions are usually responsible for proteinuria and the nephrotic syndrome. This also holds true for the drug-induced glomerulopathies, of which membranous glomerulo-nephritis is the most frequent type of lesion encountered. Apart from this, several cases of different glomerular changes such as focal segmental glomerulosclerosis and crescentic glomerulonephritis have also been reported. The drug-induced glomerulopathies are probably immune mediated. This is, for instance, reflected in the fact that patients with drug-induced nephritic syndrome frequently have the HLA-B8 and DR3 antigens. In depth information is provided for the previously mentioned disorders.

Glomerular tip lesion associated with nonsteroidal anti-inflammatory drug-induced nephrotic syndrome

Glomerular tip lesion and its relation to different glomerular diseases is a subject of controversy. The therapeutic and prognostic clinical implications of glomerular tip lesions are ambiguous. We present a case of glomerular tip lesion associated with nonsteroidal anti-inflammatory drug-induced nephrotic syndrome that further complicates this issue. To our knowledge, this is the first case report of glomerular tip lesion associated with nonsteroidal anti-inflammatory drug-induced nephrotic syndrome.

Cyclooxygenase-2 inhibitor-associated minimal-change disease

Selective cyclooxygenase-2 (COX-2) inhibitors are relatively newer anti-inflammatory drugs that produce comparable antiinflammatory and analgesic effects to the nonselective nonsteroidal antiinflammatory drugs (NSAIDs); but with fewer symptomatic gastric and duodenal ulcers. Limited data are available concerning the toxicity associated with COX-2 inhibitors outside the gastrointestinal tract. The NSAIDs have been known for their nephrotoxic potentials including minimal-change disease (MCD) with interstitial nephritis. Although the recent data suggests that COX-2 inhibitors may have the same adverse renal effect as NSAIDs, there is only one case report describing minimal change disease and acute interstitial nephritis (AIN) associated with a COX-2 inhibitor, celecoxib. We are reporting a case of MCD and acute tubular necrosis (ATN) but without interstitial nephritis in a patient treated with celecoxib. Although the proteinuria in our patient resolved completely after discontinuation of celecoxib, the renal function did not. We suggest that heightened suspicion of this side effect of COX-2 inhibitors should be maintained in all patients taking this class of drugs who present with nephrotic syndrome.

Combined therapy of cilazapril and losartan has no additive effects in ameliorating adriamycin-induced glomerulopathy

AIMS

Effects of the blockade of renin-angiotensin system (RAS), by angiotensin-converting enzyme inhibitor (ACEi), type 1 angiotensin II receptor blocker (ARB), or a combination of both, were evaluated in Adriamycin (ADR)-induced glomerulopathy.

METHODS

Male Sprague-Dawley rats (180-250 g) were induced of glomerulopathy by treatment with ADR (2 mg/kg, i.v.). Six weeks later, they were treated with cilazapril (1 mg/kg/day) and/or losartan (10 mg/kg/day) for an additional 6 weeks.

RESULTS

The urinary excretion of protein progressively increased following the treatment with ADR, which was prevented by ACEi, ARB, and a combination of both. Similarly, the glomerulopathy assessed by glomerulosclerosis index was also ameliorated by ACEi or ARB. However, combined therapy of both ACEi and ARB was without an additional effect (Control 1.4 +/- 0.4%, ADR 10.7 +/- 2.7%**, ACEi 0.8 +/- 0.4%, ARB 2.6 +/- 1.0%, ACEi+ARB 1.7 +/- 1.5%, ** p < 0.01 vs. Control). The expression of transforming growth factor-beta(1) was increased following the treatment with ADR (1.4 +/- 0.07-fold, p < 0.05 vs. Control), however, the degree of which was similarly blunted by either ACEi, ARB, or the combination of both. The expression of type 1 angiotensin II receptor mRNA increased following the treatment with ADR, the degree of which was further upregulated by ACEi and decreased by ARB to the control level (ADR 1.3 +/- 0.06-fold*, ACEi 1.8 +/- 0.05-fold***, ARB 1.0 +/- 0.04-fold, * p < 0.05 and *** p < 0.001 vs. Control). The combined therapy of ACEi and ARB still showed an upregulation of type 1 angiotensin II receptor mRNA, however, of which degree was mitigated compared with that induced by ACEi alone (ACEi+ARB 1.5 +/- 0.04-fold, ** p < 0.01 vs. Control). On the contrary, the expression of type 2 angiotensin II receptor mRNA was downregulated following the treatment with ADR, which was similarly restored to the control level by ACEi, ARB, and a combination of both (ADR 0.5 +/- 0.08-fold**, ACEi 1.0 +/- 0.06-fold, ARB 1.0 +/- 0.05-fold, ACEi+ARB 1.0 +/- 0.05-fold, ** p < 0.01 vs. Control).

CONCLUSION

It is suggested that combined therapy of ACEi and ARB with relatively high or maximal doses of each drug has no additive or synergistic benefits on the progression of ADR-induced glomerulopathy. Effects of RAS blockade may in part be related to differential regulation of type 1 and type 2 angiotensin II receptors.

[Experimental study on treatment of minimal change nephropathy with Lespedeza michx]

OBJECTIVE

To study the therapeutic effect of Lespedeza Michx in experimental rat model of minimal change nephropathy (MCN).

METHOD

The rat MCN model was reproduced by tail-intravenous injection of Adriamycin. The treatment effect of Lespedeza Michx was determined by the detection of urine protein collection for 24 hours, malondialdehyde (MDA), superoxide dismutase (SOD), ATCO, IL-8, TNF-alpha in serum, and renal histopathological changes were observed by microscope.

RESULT

Lespedeza Michx could decrease the contents of urine proteinuria, MDA, IL-8, and TNF-alpha in serum, increase SOD level and improved the pathological change of glomeruli.

CONCLUSION

Lespedeza Michx was effective on MCN.

[Experimental study on treatment of minimal change nephropathy with niaozhuoqing]

OBJECTIVE

To study the therapeutic effect of niaozhuoqing on minimal change nephropathy (MCN) in rats.

METHODS

The MCN rat model was induced by intravenous injection of adriamycin. The effect of treatment on 24h urine protein, serum protein, lipid metabolism, malondialdehyde (MDA), superoxide dismutase (SOD) in serum, and renal histopathological changes were observed.

RESULTS

Niaozhuoqing could decrease the contents of proteinuria, blood lipid and MDA in serum, increase serum protein, SOD level and pathologically restore the glomeruli.

CONCLUSION

Niaozhuoqing has good effects on MCN, which probably related to decrease serum lipids level and reduce oxygen free radicals.

[Minimal changes nephrotic syndrome associated to penicillamine treatment]

We describe three patients with minimal change nephrotic syndrome associated with penicillamine treatment. Two patients had systemic sclerosis and one had rheumatoid arthritis. Cumulative dose of D-penicillamine was similar in all cases, and nephrotic syndrome appeared after 15-33 months of treatment. The drug was stopped and nephrotic syndrome disappeared in 2-4 months, suggesting a possible causal relationship between penicillamine and minimal change disease.

Photodynamic therapy using verteporfin-induced minimal change nephrotic syndrome

PURPOSE

To report a case of minimal change nephrotic syndrome (MCNS) after photodynamic therapy using verteporfin.

DESIGN

Interventional case report.

METHODS

After four cycles of photodynamic therapy, general weakness with generalized edema developed in an otherwise healthy 66-year-old woman, resulting in dyspnea and ascites. Urinalysis showed heavy proteinuria (4+) with decreased serum total protein and albumin, and increased total cholesterol levels, suggesting nephrotic syndrome. Renal biopsy and pathologic diagnosis were performed.

RESULTS

Renal biopsy revealed normal glomeruli and tubulointerstitium by light microscopy, with no immunoglobin or complement deposition. Transmission electron microscopy showed diffuse effacement of the foot processes of visceral epithelial cells, which is the characteristic finding of minimal change nephrotic syndrome.

CONCLUSIONS

We herein report a case of minimal change nephrotic syndrome after photodynamic therapy using verteporfin.

Guillain-Barré syndrome associated with minimal change glomerulopathy and tubular dysfunction - related to acetone-based organic solvent?

A 55-year-old woman presented with Guillain-Barré syndrome, nephrotic syndrome and multiple tubular dysfunction under occupational exposure to an organic solvent, which contained acetone as the principal solvent. In this case, the onset of the nephrotic syndrome and tubular dysfunction coincided with the development of the neurological manifestation. Renal biopsy demonstrated minimal change glomerulopathy with moderate tubulointerstitial nephritis. Several clearance tests that evaluated tubular transport functions revealed multiple tubular defects (including the Na(+)-K(+)-Cl(-) cotransporter of thick ascending limb and distal proton pump). The simultaneous occurrence of Guillain-Barré and nephrotic syndrome has previously been reported. However, both minimal glomerulopathy with multiple tubular dysfunction and progressive peripheral neuropathy under occupational exposure to an organic solvent remain unreported. Herein, we presented a rare association of minimal change nephrotic syndrome, tubular dysfunction with Guillain-Barré syndrome under the risk of exposure to an acetone-based cleansing solution; the case raises our concerns about possible chronic nephrotoxic or neurotoxic effects of common chemical organic solvents.

Downregulation of vascular endothelial growth factor and its receptors in the kidney in rats with puromycin aminonucleoside nephrosis

AIM

We aimed to examine the possible involvement of vascular endothelial growth factor (VEGF) in the pathogenesis of puromycin aminonucleoside nephrosis (PAN).

METHODS

The expression and localization of the mRNA of VEGF and its receptors, flt-1 and flk-1, were analyzed in the kidneys of puromycin aminonucleoside-injected rats by use of Northern blotting and in situ hybridization.

RESULTS

In association with the induction of proteinuria, VEGF mRNA underwent decrease in amount from 3 days after the injection, reaching the minimum level at 7 days, followed by a gradual recovery by 28 days. The levels of flk-1 and flt-1 mRNA showed similar transient decrease in PAN kidney, whereas the mRNA of von Willebrand factor, a marker of endothelial cells, showed no change in amount. In the normal rat kidney, VEGF mRNA was localized primarily to podocytes, and flk-1 mRNA was localized exclusively to endothelial cells with much higher intensity in glomeruli than in peritubular capillaries. In PAN kidney, the intensities of both VEGF and flk-1 signals in podocytes and glomerular endothelial cells, respectively, appeared much lower at 7 days than in normal kidney.

CONCLUSION

These results indicate that the VEGF-VEGF receptor system is downregulated in PAN, implying that it is not involved in the mechanism of proteinuria in PAN.

The selective adenosine A1 receptor antagonist KW-3902 prevents radiocontrast media-induced nephropathy in rats with chronic nitric oxide deficiency

Several studies have recently suggested a principal role of adenosine in the pathogenesis of radiocontrast media-induced nephropathy. In the present experiments, we therefore investigated the renal protective effects of 8-(noradamantan-3-yl)-1,3-dipropylxanthine (KW-3902), a potent and selective adenosine A1 receptor antagonist, on radiocontrast media-induced nephropathy in the model of the N-pi-nitro-L-arginine methyl ester (L-NAME) hypertensive, chronic nitric oxide (NO)-depleted rat. Chronic NO depletion was induced by pretreatment with L-NAME, 50 mg/ml, added to drinking water for 8 weeks. Clearance experiments were performed in anesthetized rats and glomerular filtration rate was assessed prior to and following the application of high osmolar radiocontrast media (sodium diatrizoate, 3 ml/kg, i.v.) or an equivalent volume of isoosmolar mannitol to examine the role of hyperosmolarity in radiocontrast media-induced nephropathy. Subgroups received KW-3902 (0.1 mg/kg, i.v.), 20 min prior to radiocontrast media administration. Age-matched, untreated rats served as controls. Radiocontrast media application induced a significant decline in glomerular filtration rate in L-NAME hypertensive animals, whereas no effects were observed in control rats. KW-3902 fully prevented the drop in glomerular filtration rate in response to radiocontrast media in L-NAME hypertensive rats. No renal hemodynamic alterations were observed in mannitol-infused animals. The present experiments demonstrate that the decrease in glomerular filtration rate following radiocontrast media occurred independently of the osmotic load, and that KW-3902 effectively prevented the radiocontrast media-induced deterioration in renal function. KW-3902 may be especially beneficial in patients at high risk for developing acute renal failure following radiocontrast media application or in patients in which extracellular fluid volume expansion is limited by clinical conditions such as congestive heart failure.

Glomerulosclerosis in adriamycin-induced nephrosis is accelerated by a lipid-rich diet

The present study was performed to determine quantitatively the effect of hypercholesterolemia induced by a lipid-rich diet on glomerulosclerosis in an animal model of nephrotic syndrome (NS) induced by Adriamycin (ADR). Twenty NS Wistar rats administered ADR with a single intravenous dose of 5 mg/kg body weight were divided into standard and lipid-rich chow groups. Another 20 weight-matched non-NS rats that received a vehicle alone were grouped as controls. Quantitative analyses of renal histological changes were performed with determination of blood and urine biochemical parameters. It was found that serum cholesterol was markedly higher in rats with lipid-rich chow in both NS and non-NS rats. Urinary protein was significantly higher in rats on the lipid-rich diet in the NS group. The mesangial matrix and cell indices were significantly increased in rats with the lipid-rich diet and the most obvious changes were found in the NS group. Lipid deposits and foam cells were observed in mesangial areas, and some glomeruli had progressed to form focal and segmental glomerulosclerosis in the NS group. Findings indicated that diet-induced hyperlipidemia can lead to proliferation of mesangial cells and accumulation of mesangial matrices, and further aggravate glomerulosclerosis in Adriamycin-induced nephrosis.

[Tiopronin-induced nephrotic syndrome with minimal glomerular lesions]

BACKGROUND

In the very large majority of cases, nephrotic syndrome with minimal glomerular lesions is an idiopathic condition. Drugs can favor the glomerulopathy. The effect of non-steroidal antiinflammatory drugs is well known, but other drugs, particularly tiopronin may be incriminated.

CASE REPORT

A 73-year-old patient developed severe nephrotic syndrome with minimal glomerular lesions 6 weeks after tiopronin therapy was initiated. Complete and spontaneous remission of the nephrotic syndrome was achieved 5 weeks after drug withdrawal. No recurrent lipoidic nephrosis has been observed at 3 years follow-up.

CONCLUSION

Tiopronin-induced nephrotic syndrome with minimal glomerular lesions is usually severe and develops rapidly. Remission occurs rapidly after drug withdrawal. Weekly urine checks with dip-strips should be proposed in patients treated with tiopronin.

Effects of recombinant human serum albumin on ascites in rats with puromycin aminonucleoside-induced nephropathy

1. Recombinant human serum albumin (rHSA) (1 g/kg) significantly decreased the weight of ascites in rats with puromycin aminonucleoside-induced nephropathy. 2. Furosemide (1-30 mg/kg) did not significantly reduce the weight of ascites in this model. 3. A combination of rHSA (1 g/kg) with furosemide (5 mg/kg) significantly decreased the weight of ascites in this model compared with furosemide alone. 4. In consideration of these results, rHSA can be a substitute for human serum albumin products prepared from human plasma in therapy for ascites or edema in furosemide-resistant nephrotic syndrome.

Structure-activity relationship for two lipoxygenase inhibitors and their potential for inducing nephrotic syndrome

In a study of structure-activity relationship with drug-induced nephropathy two lipoxygenase inhibitors, the N-hydroxyurea derivative 70C ((E)-N-{3-[3-(4-fluorophenoxy) phenyl]-1-(R, S)-methylprop-2-enyl}-N-hydroxyurea) and the N-hydroxamic acid analogue 360C ((E)-N-{3-[3-(4-fluorophenoxy) phenyl]-1-(R, S)-methylprop-2-enyl}-N-hydroxamic acid), were administered to rats. 70C and 360C were dosed to female Wistar rats at 100 mg/kg po daily for 7 days. Another group of rats was given a single intravenous bolus dose of puromycin aminonucleoside (PAN) at 100 mg/kg. Urine samples were collected from all groups during the study and plasma samples were collected after 7 days. Kidneys were excised and fixed for examination by electron microscopy. 70C- and PAN-treated groups both showed early changes in the glomeruli, in which the visceral cells appeared enlarged and showed varying degrees of foot process loss. This foot process loss was associated with decreases in total plasma protein and albumin and increases in the plasma cholesterol, triglycerides, creatinine, and urea were recorded. Marked proteinuria was observed in both the 70C and PAN groups. The foot process loss together with increased proteinuria, hypoalbuminemia, hypercholesterolemia, and lipemia are all characteristic of the human condition, Minimal Change Nephrotic Syndrome. All the biochemical and morphological investigations showed that 360C-treated rats were similar to the control group, suggesting that the hydroxyurea moiety of 70C is responsible, either directly or indirectly, for the induction of the nephrotic syndrome seen in rats.