Cutaneous vasculitis and glomerulonephritis associated with C4 deficiency.

Complete deficiency of the fourth component of complement (C4) is an extremely rare condition. However, it has been reported that partial C4 deficiency can occur in normal subjects, and is associated with several immune diseases. We report a 44-year-old woman who developed slight oedema and punctate purpura on her lower legs after a common cold. She was noted to have persistent microscopic haematuria and proteinuria, and her C4 level was undetectable. On histological examination of a skin biopsy specimen, leucocytoclastic vasculitis was seen, with granular deposition of IgG, IgM, C3 and C1q on the vessel walls in the upper dermis. A renal biopsy showed mild mesangial proliferative glomerulonephritis with slight damage to the capillary loops, and granular deposits of IgM and C4 mainly in the mesangium. The patient was systemically well and needed no medication. The C4 level remained low during the observation period, but neither genotyping nor allotyping analysis identified a C4 deficiency.

Revascularization by percutaneous transluminal angioplasty improved abruptly deteriorated ischaemic symptoms in cutaneous polyarteritis nodosa.

We report a patient with cutaneous polyarteritis nodosa, who had a 3-year history of recurrent leg and foot ulcers. Symptoms of ischaemia in the left foot, including severe pain, coldness, paraesthesia and violaceous discoloration, deteriorated abruptly, because of complete occlusion of the left anterior tibial artery. The occluded segment was revascularized by percutaneous transluminal angioplasty, resulting in a dramatic improvement in the ischaemic symptoms.

Urinary liver-type fatty acid-binding protein levels for differential diagnosis of idiopathic focal glomerulosclerosis and minor glomerular abnormalities and effect of low-density lipoprotein apheresis.

AIMS: Focal glomerulosclerosis (FGS) and minor glomerular abnormalities are kidney diseases characterized by massive proteinuria. Urinary liver-type fatty acid-binding protein (L-FABP), an intracellular carrier protein of free fatty acids, is expressed in proximal tubules of the human kidney. Patients with FGS show significant improvement with low-density lipoprotein (LDL) apheresis. The aim of the present study was to determine whether urinary L-FABP levels differ between patients with FGS and those with minor glomerular abnormalities and whether levels are altered by LDL apheresis. PATIENTS AND METHODS: There were 24 patients with minor glomerular abnormalities (nephrotic stage, n = 14, remission stage, n = 10), 17 patients with FGS, and 20 healthy age-matched subjects were included in the present study. Urinary L-FABP levels were measured by enzyme-linked immunosorbent assay and compared. All patients with minor glomerular abnormalities at the nephrotic stage received prednisolone for 6 months, and all FGS patients received some form of immunosuppression therapy with prednisolone, cyclophosphamide or mizoribine for 12 months. LDL apheresis was performed in eight FGS patients with drug-resistant nephrotic syndrome. RESULTS: Urinary L-FABP levels were significantly higher in the 17 FGS patients (82.0 +/- 44.4 microg/g.Cr) than in the 24 patients with minor glomerular abnormalities (10.2 +/- 8.4 microg/g.Cr) (p < 0.01) and in the 20 healthy subjects (7.4 +/- 4.2 microg/g.Cr) (p < 0.01). Urinary L-FABP levels differed little between nephrotic stage and remission stage in patients with minor glomerular abnormalities. Urinary L-FABP levels were significantly higher in the eight drug-resistant FGS patients (122.6 +/- 78.4 microg/g.Cr) than in the nine drug-sensitive FGS patients (45.9 +/- 32.0 microg/g.Cr). Urinary L-FABP levels did not correlate with levels of other clinical markers including serum creatinine, urinary protein, and urinary N-acetyl-beta-D- glucosaminidase. In the eight drug-resistant FGS patients, LDL-apheresis significantly reduced urinary protein excretion (p < 0.01) and urinary L-FABP levels (p < 0.01). CONCLUSIONS: Urinary L-FABP may be a useful diagnostic indicator for differentiation between FGS and minor glomerular abnormalities. LDL apheresis may be effective in ameliorating tubulointerstitial lesions associated with FGS.

Expression of vascular endothelial growth factor in hepatocellular carcinoma and the surrounding liver: correlation with MR imaging and angiographically assisted CT.

We summarize and discuss our previous research results on the correlation between findings on magnetic resonance (MR) imaging and angiographically assisted computed tomography (CT) and the intensity of vascular endothelial growth factor (VEGF) expression in hepatocellular carcinoma (HCC) and in the surrounding nontumorous liver. MR images (n = 22), CT during arterial portography (n = 20), and CT hepatic arteriography (n = 17) were retrospectively correlated quantitatively and qualitatively with VEGF expression in HCCs and in the surrounding liver assessed by western blotting. HCC-to-liver contrast-to-noise ratio correlated with VEGF expression index (VEGF(IND)) values of HCCs inversely on opposed-phase, T1-weighted, spoiled gradient recalled-echo (GRE) images, directly on T2-weighted, fast spin-echo images, and marginally and inversely on gadolinium-enhanced hepatic arterial-phase GRE images. On T2-weighted fast spin-echo images, standard deviation ratio of HCCs correlated directly with VEGF(IND) values of HCCs. By CT hepatic arteriography, the contrast-enhancement index of HCCs showed a moderate inverse correlation with VEGF(IND) values of HCCs, and the contrast-enhancement index of the liver showed marginal, moderate direct correlation with VEGF(IND) values in the liver. Heterogeneities of HCCs on images correlated directly with VEGF(IND) values of HCCs on opposed-phase T1-weighted GRE images, T2-weighted fast spin-echo images, hepatic arterial-phase GRE images, equilibrium-phase GRE images, and CT hepatic arteriogram. Our results may reflect that MR signal intensity, hepatic arterial vascularity, and heterogeneity of HCCs on CT or MR images are closely related to the intensity of VEGF expression in HCC as upregulated by hyper- or hypoxia in HCCs. Although the real effects of our results on radiologic practice are debatable at this moment, we believe that our results may help future radiologic practice in conjunction with biomolecular or genetic treatment for HCCs.

Comparative effects of plasmapheresis and intravenous cyclophosphamide on urinary podocyte excretion in patients with proliferative Lupus nephritis.

Intravenous cyclophosphamide (IVC) in combination with steroids is standard therapy for Lupus nephritis. Reduction of autoantibodies and circulating immune complexes can be used in the treatment of autoimmune diseases. The aim of the present study was to compare the effects of IVC pulse therapy and double-filtration plasmapheresis (DFPP) on proteinuria and urinary excretion of podocytes in adult patients with diffuse proliferative Lupus nephritis (DPLN). Twenty patients were randomly assigned to two groups. Group A (n = 10) was treated with IVC (0.75 - 1.0 g/m2 body surface area) pulse therapy, given as boluses once a month for 6 consecutive months, combined with oral corticosteroid (up to 1 mg/kg/day) administration. Group B (n = 10) was treated with a combination of DFPP (performed 1-2 times weekly) and corticosteroid (up to I mg/kg/ day). The total average number of treatments was 8.4 and the therapeutic efficacies were evaluated after 6 months. Twenty healthy individuals participated as a control group. Urinary podocytes were examined by immunofluorescence with monoclonal antibodies against podocalyxin. Both Group A and Group B reduced proteinuria (p < 0.001) as well as the number of urinary podocytes (p < 0.001). Differences between the 2 treatment outcomes were not statistically significant. Cyclophosphamide pulse therapy and DFPP may be similarly effective in the treatment of podocyte injury in patients with DPLN.

Combination therapy of trandolapril and candesartan cilexetil reduces microalbuminuria and urinary endothelin-1 excretion in patients with type 2 diabetes.

Background. Angiotensin (AT)-converting enzyme inhibitors (ACEIs) and AT1-receptor blockers (ARBs) are widely used to reduce urinary albumin excretion (UAE) and slow the progression of diabetic nephropathy. The aim of the present study was to determine whether treatment with trandolapril (an ACEI) and candesartan cilexetil (an ARB) in combination has more effect on UAE and urinary endothelin (ET)-1 excretion than treatment with trandolapril or candesartan cilexetil alone in patients with type 2 diabetes. Methods. Sixty normotensive type 2 diabetes patients with microalbuminuria were randomly assigned to four treatment groups: (A) treatreatment with trandolapril at 2 mg/day (n = 15), (B) treatment with candesartan cilexetil at 8 mg/day (n = 15), (C) treatment with trandolapril at 2 mg/day and candesartan cilexetil at 8 mg/day (n = 15), and (D) treatment with placebo (n = 15). The study period was 18 months. UAE, urinary ET-1, and plasma ET-1 levels were measured in the patients before treatment and after 12 and 18 months of treatment. Results. Before treatment, UAE, urinary ET-1, and plasma ET-1 levels differed little between the four groups. Trandolapril and candesartan cilexetil administered alone reduced UAE and urinary ET-1 excretion to a similar extent (12 months; P < 0.05 and 18 months; P < 0.01). When trandolapril and candesartan cilexetil were coadministered, UAE and urinary ET-1 excretion decreased to a significantly greater extent at 12 and 18 months (P < 0.05) than with trandolapril or candesartan cilexetil alone. However, plasma ET-1 and systemic blood pressure levels were not affected. Conclusions. The data suggest that combination therapy with trandolapril and candesartan cilexetil has an additive effect on the reduction of microalbuminuria in microalbuminuric normotensive type 2 diabetes patients.

Tumor cell growth inhibition and extracellular signal-regulated kinase (ERK) phosphorylation by novel K vitamins.

2-(2-hydroxy-ethylsulfanyl)-3-methyl-1,4-naphthoquinone or CPD-5, a K vitamin analog, was previously indicated to be a potent growth inhibitor for Hep 3B hepatoma cells in vitro. Here, we show that CPD-5 and two newly synthesized analogs, 2-(2-hydroxy-ethylsulfanyl)-3-methyl-5- nitro-1,4-naphthoquinone (PD-37) and 2-(2-hydroxy-ethylsulfanyl)-3- methyl-5-acetylamino-1,4-naphthoquinone (PD-42), are potent growth inhibitors of 13 different human cancer cell lines, with IC50 values in the range of 3-54 microM. Phospho-ERK was induced by each of three K vitamin analogs in every cell line in a dose-dependent manner, at growth inhibitory doses. ERK phosphorylation and growth inhibitory effects were strongly correlated, with p=0.0080 for CPD-5, p=0.0076 for PD-37 and p=0.0251 for PD-42. The induction of phospho-ERK and growth inhibition were antagonized by thiol-containing anti-oxidants, but not by catalase, consistent with a possible arylating mechanism. The data show a novel class of growth inhibitors with a wide spectrum of action that induces ERK hyper-phosphorylation, as a possible new growth inhibitory feature.

The yeast SAS (something about silencing) protein complex contains a MYST-type putative acetyltransferase and functions with chromatin assembly factor ASF1.

It is well established that acetylation of histone and nonhistone proteins is intimately linked to transcriptional activation. However, loss of acetyltransferase activity has also been shown to cause silencing defects, implicating acetylation in gene silencing. The something about silencing (Sas) 2 protein of Saccharomyces cerevisiae, a member of the MYST (MOZ, Ybf2/Sas3, Sas2, and TIP60) acetyltransferase family, promotes silencing at HML and telomeres. Here we identify a ~450-kD SAS complex containing Sas2p, Sas4p, and the tf2f-related Sas5 protein. Mutations in the conserved acetyl-CoA binding motif of Sas2p are shown to disrupt the ability of Sas2p to mediate the silencing at HML and telomeres, providing evidence for an important role for the acetyltransferase activity of the SAS complex in silencing. Furthermore, the SAS complex is found to interact with chromatin assembly factor Asf1p, and asf1 mutants show silencing defects similar to mutants in the SAS complex. Thus, ASF1-dependent chromatin assembly may mediate the role of the SAS complex in silencing.

Pioglitazone reduces urinary podocyte excretion in type 2 diabetes patients with microalbuminuria.

In various renal diseases, including diabetic nephropathy, detection of podocytes in the urine indicates severe injury to podocytes in the glomeruli. Pioglitazone is a newly developed antidiabetic agent that attenuates insulin resistance. The aim of the present study was to determine whether pioglitazone affects urinary albumin excretion (UAE) or the number of urinary podocytes or both in type 2 diabetes patients with microalbuminuria. Twenty-eight patients with normotensive type 2 diabetes and microalbuminuria (18 men and 10 women; mean age, 52.5 years) and 30 age-matched normotensive controls (20 men and 10 women; mean age, 51.5 years) were included in the study. Urinary podocytes were detected by immunofluorescence with a monoclonal antibody against podocalyxin. Patients were randomly assigned to 2 groups: a pioglitazone-treatment group (30 mg/day, n = 14) and a placebo group (n = 14). Treatment was continued for 6 months. Podocytes were absent in the urine of healthy controls, but detected in 17 of 28 diabetic patients (60.7%). UAE was reduced from 96.7 +/- 50.5 microg/min to 39.7 +/- 22.9 microg/min (P <.01) in the pioglitazone-treatment group, and the number of urinary podocytes was reduced from 0.9 +/- 1.0 cells/mL to 0.1 +/- 0.2 cells/mL (P <.001). Neither UAE nor the number of urinary podocytes was affected in the placebo group. These data indicate that pioglitazone is effective for reducing UAE and podocyte injury in early-stage diabetic nephropathy.

Mechanism of novel vitamin K analog induced growth inhibition in human hepatoma cell line.

BACKGROUND/AIMS: To understand the mechanisms of liver regeneration or hepatoma apoptosis, it is important to estimate the turning point of the signal transduction by growth factor receptor. Since 2-(2-hydroxyethylsulfaryl) 3-methyl-1,4-naphthoquinone or CPD 5 has been shown to mediate the phosphorylation of epidermal growth factor (EGF) receptor in Hep3B hepatoma cells, the differences between EGF and CPD 5-mediated signal transduction were studied. METHODS: DNA content was measured by Hoechst fluorescent assay. Phosphorylated proteins were described with Western blots or two-dimensional electrophoresis. RESULTS: CPD 5-induced EGFR phosphorylation was functional to stimulate Ras pathway. However, CPD 5-mediated extracellular signal-regulated kinase (ERK) phosphorylation was not antagonized by inhibition of upstream activation with PD153035. CPD 5 inhibited ERK dephosphorylation in cell lysate, suggesting that ERK phosphorylation by CPD 5 was depending on kinase activity and phosphatase inhibition. Two-dimensional electrophoresis showed extra phospho ERK spot, which was indicated to have close association with CPD 5-induced growth inhibition, since U0126 antagonized growth inhibition and appearance of this spot. CONCLUSIONS: The turning point of EGFR pathway was proved to have close association with the expressed level of phosphorylated ERK. ERK phosphorylation was suggested to play a critical role in growth factor-induced signal transduction.

Critical role of extracellular signal-regulated kinase phosphorylation on menadione (vitamin K3) induced growth inhibition.

BACKGROUND: Although it is widely known that the extracellular signal-regulated kinase (ERK) pathway stimulates cell growth and protects cells from death, recent findings have proposed a proapoptotic action of ERK phosphorylation. Because the authors found that vitamin K3 (VK3) was a potent growth inhibitor and an inducer for ERK phosphorylation through a specific pathway in the stomach cancer cell line, the critical role of ERK phosphorylation in VK(3)-mediated growth inhibitory effect was examined. METHODS: The fluorochrome Hoechst 33258 assay (Hoechst AG [now Aventis] Frankfort, Germany) was used for counting cells (excitation at 360 nm; emission at 460 nm). For two-dimensional electrophoresis, cells were dissolved in urea standard buffer and applied first to isoelectronic focusing gels. Cell lysates were subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) using 10% polyacrylamide gels. To examine the phosphorylation of receptors, cell lysates were immunoprecipitated with receptor antibody. RESULTS: VK3 induced phosphorylation of hepatocyte growth factor receptor (c-met), epidermal growth factor receptor (EGFR), or external signal-regulated kinase (ERK), which increased progressively to a maximum level at 30 minutes, in a dose-dependent manner and occurred at growth inhibitory concentrations. VK(3)-mediated growth inhibition and protein tyrosine phosphorylation were nullified completely by glutathione or L-cysteine but not by nonthiol antioxidants, thus suggesting that sulfhydryl arylation might have been involved in VK(3)-mediated action. The phosphorylation of EGFR and c-met by VK(3) appeared to be functional, because these were coimmunoprecipitated with growth factor receptor-bound protein 2 (Grb2) and SOS1 antibody. Epidermal growth factor (EGF) or hepatocyte growth factor (HGF) stimulated increase of cyclin D1 protein after 12 hours and increased DNA content after 3 days in culture. In addition, U0126, which is a potent inhibitor for ERK phosphorylation, antagonized increase of cyclin D1, thus suggesting that EGF- or HGF-mediated ERK phosphorylation might have played an essential role for cell growth. By contrast, ERK phosphorylation by VK3 was more prolonged and intense than the signal induced by the growth factors. U0126 reduced ERK phosphorylation and prevented growth inhibition by VK3. Two-dimensional gels showed VK(3)-induced additional phospho-ERK spots, compared with those obtained from growth factors. This extra spot was completely antagonized by U0126. CONCLUSIONS: VK(3)-induced growth inhibition and protein tyrosine phosphorylation were mediated by the sulfhydryl arylation system. The tyrosine phosphorylation of EGFR or c-met by VK3 activated the Ras signaling pathway. The overexpressed ERK phosphorylation by VK3 seemed to originate from additional spots on two-dimensional gels, which played a critical role in VK(3)-induced growth inhibitory action despite the fact that ERK phosphorylation by growth factors had had an essential association with cell growth.

Identification of zinc finger proteins bound to a silencer region in the rat glutathione transferase P gene.

The rat glutathione transferase P (GST-P) gene is strongly induced during chemical hepatocarcinogenesis, whereas mRNA of this gene is rarely expressed in normal rat liver. We previously identified a silencer region in the promoter of this gene. This silencer has several DNA binding sites and at least three proteins (Silencer factor A, -B, and -C (SF-A, SF-B, and SF-C)) bind to these sites. We previously cloned and characterized the Nuclear Factor 1 (NF1) family and the CCAAT/enhancer-binding protein (C/EBP) family as SF-A and SF-B, respectively. However, SF-C which binds to GST-P silencer 2 (GPS2) remains to be cloned. By screening using yeast one-hybrid system, several zinc finger proteins were identified as a candidate of SF-C. The gel-mobility shift analyses showed that BTEB2, EZF, LKLF, TFIIIA, TIEG1, and novel zinc finger protein MZFP bound to GPS2 with different affinities. Several proteins of these are known to be transcriptional activators or repressors, suggesting that zinc finger proteins bind to GPS2 and regulate GST-P expression in the rat liver.

Effect of cerivastatin on urinary albumin excretion and plasma endothelin-1 concentrations in type 2 diabetes patients with microalbuminuria and dyslipidemia.

BACKGROUND/AIMS: To determine whether cerivastatin, a newly developed novel synthetic potent statin, exerts a renoprotective effect, we assessed urinary albumin excretion (UAE) and plasma and urinary endothelin (ET)-1 concentrations in normotensive microalbuminuric type 2 diabetes patients with dyslipidemia. METHODS: Sixty normotensive type 2 diabetic patients (38 men and 22 women; mean age 56.5 years) with microalbuminuria (20-200 microg/min) and dyslipidemia (total cholesterol >200 mg/dl, LDL cholesterol >160 mg/dl, HDL cholesterol <35 mg/dl, and triglyceride >150 mg/dl) were enrolled in a double-blind study for 6 months, receiving either cerivastatin (0.15 mg/day) or placebo. Plasma and urinary ET-1 concentrations were measured by radioimmunoassay. RESULTS: Cerivastatin did not affect serum creatinine and HbA(1c) levels, and reduced systolic blood pressure slightly, but not significantly. Plasma levels of total cholesterol and LDL cholesterol were significantly reduced (p < 0.01), and plasma triglyceride levels were also reduced significantly (p < 0.05) after 6 months of cerivastatin treatment. A concomitant significant decrease in UAE (p < 0.01), and urinary and plasma ET-1 concentrations (p < 0.01) were found during this period. CONCLUSION: The use of cerivastatin is associated with decreased microalbuminuria and plasma and urinary ET-1 levels in microalbuminuric patients with type 2 diabetic mellitus and speculate that this may represent an amelioration of renal injury.

Intrahepatic cholangiocarcinoma arising 10 years after the excision of congenital extrahepatic biliary dilation.

A 52-year-old woman was found to have a liver tumor during treatment for a liver abscess. The tumor was diagnosed as intrahepatic cholangiocarcinoma by closer examinations, including a percutaneous needle biopsy. Ten years previously, she had undergone excision of a choledochal cyst, with reconstruction by Roux-en-Y hepaticojejunostomy, as treatment for Todani's type Ia congenital biliary dilation, which had been confined only to the extrahepatic bile duct. The significant association between congenital biliary dilation and hepatobiliary malignancies is well known. Some patients have been reported to develop biliary cancer long after the excision of the entire extrahepatic bile duct and hepaticoenterostomy. However, in these patients, the development mostly took place in the remnant choledochal cyst, the anastomotic site, or in the dilated intrahepatic bile duct of Todani's type IV-A congenital biliary dilation. The development of intrahepatic cholangiocarcinoma after operation has not been reported previously in a patient with Todani's type I congenital biliary dilation. This case suggests that the entire biliary tree may have a high risk of field cancerization, even in extrahepatic congenital biliary dilation.

Critical role of extracellular signal-regulated kinase (ERK) phosphorylation in novel vitamin K analog-induced cell death.

In the present study, we show that 2-(2-hydroxyethylsulfaryl)-3-methyl-1,4-naphthoquinone, or CPD 5, is a potent growth inhibitor for pancreas cancer cell lines (ID(50): 21.4 +/- 3.8, 31.8 +/- 2.7 and 55.2 +/- 4.5 microM for MiaPaCa, Panc-1 and BxPc3, respectively). It induced protein tyrosine phosphor-ylation of hepatocyte growth factor (HGF) receptor (c-Met) or epidermal growth factor receptor (EGFR), which increased progressively to a maximum level at 30 min in Panc-1 cells. The receptor phosphorylation by CPD 5 was indicated to be functional, since these receptors were found to bind with Grb2 or SOS1 protein. CPD 5 was also suggested to induce phosphorylation of external signal-regulated kinase (ERK). EGF induced cell proliferation through ERK phosphorylation, since U0126, which is an inhibitor of ERK phosphorylation, abrogated the increase of cyclin D1 by EGF. HGF increased the amount of p27 protein, suggesting that it is associated with cell differentiation. By contrast, U0126 reduced CPD 5-induced cell death. On two-dimensional electrophoresis, we found an extra type of phospho-ERK, and this was completely and selectively abolished by U0126. These results suggest that ERK phosphorylation, especially the extra spot on two-dimensional gel, is critically associated with CPD 5-mediated cell death.

Two nuclear localization signals are required for nuclear translocation of nuclear factor 1-A.

Nuclear factor 1 (NF1) proteins are encoded by at least four genes (NF1-A, B, C, X). Although DNA-binding and the transcription regulation domains of these proteins are well characterized, the nuclear localization signals (NLSs) are still unknown in all NF1s. We have identified two NLSs in NF1-A, and both are required for full translocation to the nucleus, although one of them itself has a partial translocation ability. These two NLSs are conserved in all four NF1s. Interestingly, three isoforms of NF1-A (NF1-A1, A2, A4) have two NLSs and translocate completely to the nucleus. In contrast, NF1-A3 lacks the second NLS and partially stays in the cytoplasm. Since NF1s construct homodimer and heterodimer, these findings indicate the differential regulations of the NF1 translocation.

Macrophage-derived MT1-MMP and increased MMP-2 activity are associated with glomerular damage in crescentic glomerulonephritis.

Membrane-type matrix metalloproteinases (MT-MMPs) have been shown to activate pro-MMP-2 on the cell surface and are suggested to be key enzymes in tissue remodelling under various physiological and pathological conditions. To investigate the role of MT-MMP in progressive renal injury, the gene expression and enzymatic activity of MT-MMP were examined in crescentic glomerulonephritis induced by anti-glomerular basement membrane (GBM) antibody in WKY rats. Isolated glomeruli were subjected to RNA and protein extraction 0, 1, 3, 7, 14, and 28 days after intravenous injection of rabbit anti-GBM antibody. Semiquantitative RT-PCR analysis revealed that among the three members of the MT-MMP family, mRNA expression of MT2-MMP remained unchanged and that of MT3-MMP was not observed in glomeruli during the development of nephritis. However, MT1-MMP gene expression increased from day 3 and reached maximum levels at day 7 (5.5+/-0.7-fold increase over day 0), closely associated with macrophage accumulation, crescent formation, and increased proteinuria. Gelatin zymography showed that the active from of MMP-2 emerged from day 7 and remained during the experimental period accompanied by increased proMMP-2, while no active form of MMP-2 was found in control rats. Using an antisense cRNA probe, intense signals of MT1-MMP mRNA were observed mostly in cells within the crescent and in some cells in the mesangial areas. Most of these cells were ED-1-positive macrophages, based on immunostaining of sequential sections. These results suggested that in the MT-MMP family, MT1-MMP was induced in infiltrating macrophages during the development of crescentic glomerulonephritis and possibly contributed to pathological degradation of glomerular extracellular matrices through the activation of proMMP-2.