Substrate specificity of glycoside hydrolase family 1 β-glucosidase AtBGlu42 from Arabidopsis thaliana and its molecular mechanism

Plants possess many glycoside hydrolase family 1 (GH1) β-glucosidases, which physiologically function in cell wall metabolism and activation of bioactive substances, but most remain uncharacterized. One GH1 isoenzyme AtBGlu42 in Arabidopsis thaliana has been identified to hydrolyze scopolin using the gene deficient plants, but no enzymatic properties were obtained. Its sequence similarity to another functionally characterized enzyme Os1BGlu4 in rice suggests that AtBGlu42 also acts on oligosaccharides. Here, we show that the recombinant AtBGlu42 possesses high kcat/Km not only on scopolin, but also on various β-glucosides, cellooligosaccharides, and laminarioligosaccharides. Of the cellooligosaccharides, cellotriose was the most preferred. The crystal structure, determined at 1.7 Å resolution, suggests that Arg342 gives unfavorable binding to cellooligosaccharides at subsite +3. The mutants R342Y and R342A showed the highest preference on cellotetraose or cellopentaose with increased affinities at subsite +3, indicating that the residues at this position have an important role for chain length specificity.

Transcriptional Suppression of Diabetic Nephropathy with Novel Gene Silencer Pyrrole-Imidazole Polyamides Preventing USF1 Binding to the TGF-β1 Promoter

Upstream stimulatory factor 1 (USF1) is a transcription factor that is increased in high-glucose conditions and activates the transforming growth factor (TGF)-β1 promoter. We examined the effects of synthetic pyrrole-imidazole (PI) polyamides in preventing USF1 binding on the TGF-β1 promoter in Wistar rats in which diabetic nephropathy was established by intravenous administration of streptozotocin (STZ). High glucose induced nuclear localization of USF1 in cultured mesangial cells (MCs). In MCs with high glucose, USF1 PI polyamide significantly inhibited increases in promoter activity of TGF-β1 and expression of TGF-β1 mRNA and protein, whereas it significantly decreased the expression of osteopontin and increased that of h-caldesmon mRNA. We also examined the effects of USF1 PI polyamide on diabetic nephropathy. Intraperitoneal injection of USF1 PI polyamide significantly suppressed urinary albumin excretion and decreased serum urea nitrogen in the STZ-diabetic rats. USF1 PI polyamide significantly decreased the glomerular injury score and tubular injury score in the STZ-diabetic rats. It also suppressed the immunostaining of TGF-β1 in the glomerulus and proximal tubules and significantly decreased the expression of TGF-β1 protein from kidney in these rats. These findings indicate that synthetic USF1 PI polyamide could potentially be a practical medicine for diabetic nephropathy.

Contribution of TGF-β1 and Effects of Gene Silencer Pyrrole-Imidazole Polyamides Targeting TGF-β1 in Diabetic Nephropathy

TGF-β1 has been known to induce diabetic nephropathy with renal fibrosis and glomerulosclerosis. DNA-recognized peptide compound pyrrole-imidazole (PI) polyamides as novel biomedicines can strongly bind promoter lesions of target genes to inhibit its transcription. We have developed PI polyamide targeting TGF-β1 for progressive renal diseases. In the present study, we evaluated the contribution of TGF-β1 in the pathogenesis of diabetic nephropathy, and examined the effects of PI polyamide targeting TGF-β1 on the progression of diabetic nephropathy in rats. For in vitro experiments, rat renal mesangial cells were incubated with a high (25 mM) glucose concentration. Diabetic nephropathy was established in vivo in eight-week-old Wistar rats by intravenously administering 60 mg/kg streptozotocin (STZ). We examined the effects of PI polyamide targeting TGF-β1 on phenotype and the growth of mesangial cells, in vitro, and the pathogenesis of diabetic nephropathy in vivo. High glucose significantly increased expression of TGF-β1 mRNA, changed the phenotype to synthetic, and increased growth of mesangial cells. STZ diabetic rats showed increases in urinary excretions of protein and albumin, glomerular and interstitial degenerations, and podocyte injury. Treatment with PI polyamide targeting TGF-β1 twice weekly for three months improved the glomerular and interstitial degenerations by histological evaluation. Treatment with PI polyamide improved podocyte injury by electron microscopy evaluation. These findings suggest that TGF-β1 may be a pivotal factor in the progression of diabetic nephropathy, and PI polyamide targeting TGF-β1 as a practical medicine may improve nephropathy.

Preclinical Study of DNA-Recognized Peptide Compound Pyrrole-Imidazole Polyamide Targeting Human TGF-β1 Promoter for Progressive Renal Diseases in the Common Marmoset

Pyrrole-imidazole (PI) polyamides are novel gene silencers that strongly bind the promoter region of target genes in a sequence-specific manner to inhibit gene transcription. We created a PI polyamide targeting human TGF-β1 (hTGF-β1). To develop this PI polyamide targeting hTGF-β1 (Polyamide) as a practical medicine for treating progressive renal diseases, we examined the effects of Polyamide in two common marmoset models of nephropathy. We performed lead optimization of PI polyamides that targeted hTGF-β1 by inhibiting in a dose-dependent manner the expression of TGF-β1 mRNA stimulated by PMA in marmoset fibroblasts. Marmosets were housed and fed with a 0.05% NaCl and magnesium diet and treated with cyclosporine A (CsA; 37.5 mg/kg/day, eight weeks) to establish chronic nephropathy. We treated the marmosets with nephropathy with Polyamide (1 mg/kg/week, four weeks). We also established a unilateral urethral obstruction (UUO) model to examine the effects of Polyamide (1 mg/kg/week, four times) in marmosets. Histologically, the renal medulla from CsA-treated marmosets showed cast formation and interstitial fibrosis in the renal medulla. Immunohistochemistry showed strong staining of Polyamide in the renal medulla from CsA-treated marmosets. Polyamide treatment (1 mg/kg/week, four times) reduced hTGF-β1 staining and urinary protein excretion in CsA-treated marmosets. In UUO kidneys from marmosets, Polyamide reduced the glomerular injury score and tubulointerstitial injury score. Polyamide significantly suppressed hTGF-β1 and snail mRNA expression in UUO kidneys from the marmosets. Polyamide effectively improved CsA- and UUO-associated nephropathy, indicating its potential application in the prevention of renal fibrosis in progressive renal diseases.

Effect of Sucroferric Oxyhydroxide on Fibroblast Growth Factor 23 Levels in Hemodialysis Patients

OBJECTIVE

This study investigated the effects of sucroferric oxyhydroxide on fibroblast growth factor (FGF)-23 and dose reduction of erythropoiesis-stimulating agents (ESA) and intravenous saccharated ferric oxide in hemodialysis patients.

METHODS

In this prospective, open-label, parallel-group, multicenter trial involving patients receiving lanthanum carbonate hydrate, eligible patients were randomized to a sucroferric oxyhydroxide group or a control group. Hemoglobin, serum phosphate, FGF-23, iron, and ferritin levels, as well as transferrin saturation, doses of intravenous saccharated ferric oxide and ESA administered, and the erythropoietin responsiveness index (ERI) were monitored for 24 weeks.

RESULTS

Sixty-eight eligible patients were allocated to receive sucroferric oxyhydroxide (n = 34) or serve as controls (n = 34). Data for 31 patients in the sucroferric oxyhydroxide group and 32 in the control group were analyzed. Serum phosphate was equally well controlled in both groups. In the sucroferric oxyhydroxide group, intact FGF-23 levels decreased significantly from baseline at the end of the study (p = 0.01) and there was a significant difference compared with the control group (p = 0.035). Required doses of ESA and ERI were significantly reduced in the sucroferric oxyhydroxide group decreased significantly. The dose of intravenous saccharated ferric oxide required in the sucroferric oxyhydroxide group was significantly lower than that at baseline (p = 0.006) and in the control group (p = 0.003).

CONCLUSIONS

Treatment of hyperphosphatemia with sucroferric oxyhydroxide was effective in patients on hemodialysis, resulting in decreased serum FGF-23 levels and a reduction in the required dose of saccharated ferric oxide.

In-liquid plasma: a novel tool in the fabrication of nanomaterials and in the treatment of wastewaters

Attempts to generate plasma in liquids have been successful and various devices have been proposed.

Targeted IgA Fc receptor I (FcαRI) therapy in the early intervention and treatment of pristane-induced lupus nephritis in mice

The Fc receptor I for IgA (FcαRI) down-regulates humoral immune responses and modulates the risk of autoimmunity. This study aimed to investigate whether FcαRI targeting can affect progression of pristine-induced lupus nephritis. In the first experiment (early intervention), four groups of animals were evaluated: untreated FcαRI/FcRγ transgenic (Tg) mice and Tg mice administered control antibody (Ctr Fab), saline and anti-FcαRI Fab [macrophage inflammatory protein (MIP)-8a], respectively, three times a week for 29 weeks, after being injected once intraperitoneally with 0·5 ml pristane. In the second experiment, antibody injection started after the onset of nephritis and was carried out for 2 months, with similar groups as described above. MIP-8a improved proteinuria, decreased the amounts of glomerular injury markers, serum interleukin (IL)-6, IL-1 and monocyte chemoattractant protein (MCP)-1, and F4/80 macrophages in the interstitium and glomeruli, in both experiments. When MIP-8a was used as early intervention, a decrease in mouse serum anti-nuclear antibody (ANA) titres and reduced deposition of immunoglobulins in glomeruli were observed. This effect was associated with reduced serum titres of immunoglobulin (Ig)G2a but not IgG1, IgG2b and IgG3. Furthermore, pathological analysis showed lower glomerular activity index and less fibronectin in MIP-8a treated mice. This study suggests that FcαRI targeting could halt disease progression and lupus activation by selective inhibition of cytokine production, leucocyte recruitment and renal inflammation. Our findings provide a basis for the use of FcαRI as a molecular target for the treatment of lupus.

Detoxification mechanism of asbestos materials by microwave treatment

The detoxification mechanism of asbestos materials was investigated through simulations and experiments. The permittivities of pure CaO and Mg3Si4O12, as quasi-asbestos materials, were measured using the cavity perturbation method. The real and imaginary parts of the relative permittivity (ɛr' and ɛr″) of CaO are functions of temperature, and numerical simulations revealed the thermal distributions in an electromagnetic field with respect to both asbestos shape and material configuration based on permittivity. Optical microscopic observation revealed that the thickness of chrysotile fibers decreased as a result of CaO heating. The heating mechanism of asbestos materials has been determined using CaO phase, and the detoxification mechanism of asbestos materials was discussed based on the heating mechanism.

Negative regulation of inflammatory responses by immunoglobulin A receptor (FcαRI) inhibits the development of Toll-like receptor-9 signalling-accelerated glomerulonephritis

Myeloid FcαRI, a receptor for immunoglobulin (Ig)A, mediates cell activation or inhibition depending on the type of ligand interaction, which can be either multivalent or monovalent. Anti-inflammatory signalling is triggered by monomeric targeting using anti-FcαRI Fab or IgA ligand binding, which inhibits immune and non-immune-mediated renal inflammation. The participation of Toll-like receptors (TLRs) in kidney pathology in experimental models and various forms of human glomerular nephritis has been discussed. However, little is known about negative regulation of innate-immune activation. In the present study, we generated new transgenic mice that express FcαRI(R209L) /FcRγ chimeric protein and showed that the monovalent targeting of FcαRI exhibited inhibitory effects in an in vivo model of TLR-9 signalling-accelerated nephritis. Mouse monoclonal anti-FcαRI MIP8a Fab improved urinary protein levels and reduced the number of macrophages and immunoglobulin deposition in the glomeruli. Monovalent targeting using MIP8a Fab attenuates the TLR-9 signalling pathway and is associated with phosphorylation of extracellular signal-related protein kinases [extracellular signal-regulated kinase (ERK), P38, c-Jun N-terminal kinase (JNK)] and the activation of nuclear factor (NF)-κB. The inhibitory mechanism involves recruitment of tyrosine phosphatase Src homology 2 domain-containing phosphatase-1 (SHP-1) to FcαRI. Furthermore, cell transfer studies with macrophages pretreated with MIP8a Fab showed that blockade of FcαRI signalling in macrophages prevents the development of TLR-9 signalling-accelerated nephritis. These results suggest a role of anti-FcαRI Fab as a negative regulator in controlling the magnitude of the innate immune response and a new type of anti-inflammatory drug for treatment of kidney disease.

Significance of glomerular activation of the alternative pathway and lectin pathway in lupus nephritis

The objective of the present study was to elucidate the association between glomerular complement depositions belonging to the alternative (AP) and lectin (LP) pathways, and clinical findings of lupus nephritis (LN). Immunofluorescence (IF) was performed on 17 LN patients using antibodies against factor B, factor H, properdin, mannose-binding lectin (MBL) and L-ficolin. Compared with factor B/factor H negative patients (n = 9), positive patients (n = 8) showed longer duration of LN (p < 0.05) and more severe interstitial fibrosis (p < 0.05). Eleven patients had properdin deposition in glomeruli, and in three of them, with a duration of LN of less than 1 month, factor B was undetectable. Compared with properdin negative patients (n = 6), positive patients (n = 11) showed significantly higher urinary protein excretion (p < 0.01). MBL/L-ficolin positive patients (n = 11) also had significantly higher urinary protein excretion (p < 0.05) compared with negative patients (n = 6). An independent association was found between glomerular deposition of properdin and that of MBL/L-ficolin (p < 0.01) in addition to factor B/factor H. Traces of glomerular activation of AP and LP reflected the clinical status of LN. It appears that glomerular deposition of each complement component, especially properdin, may be an index of the histological activity of LN.

Long-Term Effects of the Oral Adsorbent, AST-120, in Patients with Chronic Renal Failure

The oral adsorbent AST-120 has been widely used in Japan to delay the initiation of dialysis therapy in patients with chronic renal failure. This study evaluated the long-term effects of AST-120 in patients with chronic renal failure who had not previously undergone dialysis. One hundred out-patients were prospectively enrolled and prescribed 6 g/day oral AST-120 for ≥ 1 year. The clinical effectiveness of AST-120 was evaluated by comparing changes in the slope of the reciprocal serum creatinine-time plot (1/sCr slope) before and after AST-120 administration. The 1/sCr slope improved significantly after ≥ 1 year of AST-120 treatment and greatest improvement was observed in patients with the longest AST-120 administration period (> 30 months). The results suggest that long-term treatment with AST-120 may be beneficial for chronic renal failure patients in the pre-dialysis stage.

Possible involvement of mast cells in renal fibrosis in patients with IgA nephropathy

OBJECTIVE

The objective of the present study is to investigate whether human mast cells (MC) contribute to renal damage through local activation of the renin-angiotensin system, by assessing their numbers in renal biopsy specimens from patients with IgA nephropathy (IgAN) or minimal change nephrotic syndrome (MCNS).

METHODS

In patients with IgAN and MCNS, the numbers of tryptase-positive MC (MC(T)) and MC positive for both tryptase and chymase (MC(TC)) were examined histopathologically. Serum creatinine level, mean blood pressure and the severity of glomerular and tubulointerstitial lesions were also determined.

RESULTS

MC(TC) numbers differed between IgAN patients and MCNS patients. IgAN patients had more MC(TC) than MC(T). MC were found around but not in the conglomerate of the AngiotensinII (AngII)-positive cells. In the IgAN patients with the most severe pathology, the number of AngII-positive cells was correlated with that of MC(TC) and MC(T).

CONCLUSION

Chymase-dependent AngII synthesis due to human MC may be involved in the inflammatory and fibrotic processes of IgAN.

Th1 polarization in murine IgA nephropathy directed by bone marrow-derived cells

IgA nephropathy is the most common form of progressive glomerulonephritis although the pathophysiology of this nephropathy is unclear. The ddY mouse is a spontaneous animal model with variable incidence and extent of glomerular injury mimicking human IgA nephropathy. Here, we transplanted bone marrow cells from 20-week-old ddY mice with beginning or quiescent IgA nephropathy into irradiated similar ddY mice, C57Bl/6 (Th1 prone) mice, or BALB/c (Th2 prone) mice. Serum IgA/IgG complex and Th1/Th2 polarization of spleen cells was determined by enzyme-linked immunosorbent assay and confirmed by fluorescent cytometric analysis. The ddY mice with commencing IgA nephropathy demonstrated strong polarization toward Th1, while those with quiescent disease were Th2 polarized. Serum levels of IgA/IgG2a immune complex significantly correlated with the severity of the glomerular lesions. Bone marrow taken from mice with commencing IgA nephropathy conferred IgA nephropathy with Th1 polarization in recipient-quiescent mice, while transplantation from the quiescent mice ablated glomerular injury and mesangial IgA/IgG deposition in those commencing IgA disease. However, adoptive transfer of CD4(+) T cells from those whose disease began failed to induce any IgA deposition or renal injury. Our study suggests that bone marrow cells, presuming IgA producing cells, may initiate this disease. Th1 cells may be involved in the pathophysiology of the disease after glomerular IgA deposition.

Minor gene effect of leptin receptor variant on the body weight in KK/Ta mice

OBJECTIVE

Leptin is an adipocyte-derived hormone involved in body weight regulation that acts through the leptin receptor. Previous studies exploring potential association between the leptin receptor (Lepr) variant and obesity have reported conflicting results. The objectives of the present study are to evaluate (1) whether the Lepr variant contributes to type 2 diabetes and its related disorders such as obesity and (2) whether the gene interaction between Lepr and Zn-alpha(2) glycoprotein1 (Azgp1) genes is recognized using genetically homogeneous type 2 diabetic KK/Ta mice.

METHODS

The levels of leptin (Lep) and Lepr mRNA in adipose tissues and brain were measured by relative quantitative RT-PCR. The levels of leptin protein in sera were measured by enzyme-linked immunosorbent assay. Genotyping of backcross mice was performed using a mismatch primer.

RESULTS

Leptin protein and its mRNA levels were increased in KK/Ta mice. Lepr mRNA levels of KK/Ta mice did not differ from those of BALB/c mice. Sequence analysis revealed that the coding region of Lep in KK/Ta mice was identical to that in BALB/c mice. Six nucleotide polymorphisms were observed in the coding region of Lepr. In KK/Ta x (BALB/c x KK/Ta) F1 backcross mice, the Lepr variant of KK/Ta mice failed to alter any of the variables of obesity except for body weight at 20 weeks of age. However, it enhanced the effect of Azgp1 on body weight.

CONCLUSION

It is concluded that the Lepr variant contributes to obesity to some degree in KK/Ta mice.

Monocyte chemoattractant protein (MCP)-1 production via functionally reconstituted Fcalpha receptor (CD89) on glomerular mesangial cells

BACKGROUND

Fc alpha receptor (FcalphaR; CD89) is the receptor for Fc portion of IgA in various cells, and displays various immunological responses on binding. It is important to analyze the mesangial functions via FcalphaR in the pathogenesis of IgA nephropathy. However, it is still controversial whether FcalphaR is expressed on mesangial cells. To assess biological functions of FcalphaR on the mesangial cells, we established mesangial transfectants that expressed FcalphaR with or without FcRgamma chain that is a common signaling molecule of FcRs. The production of monocyte chemoattractant protein-1 (MCP-1) by mesangial cells is known to contribute to cellular infiltration into glomeruli and subsequent glomerular injuries.

METHODS

Murine mesangial cell lines (SV40 MES 13) were transfected with cDNA of the human FcalphaR. Furthermore, we co-transfected some of the FcalphaR transfectants with cDNA of human FcRgamma chain. The tyrosine phosphorylation of the intra-mesangial proteins after FcalphaR cross-linking was examined by immunoprecipitation. MCP-1 production from each transfectant stimulated with heat aggregated IgA was determined by sandwich ELISA.

RESULTS

Two kinds of mesangial transfectants stably expressed human FcalphaR with or without FcRgamma chain (FcalphaR(+), FcalphaR(+)/gamma(+)). Phosphorylation of FcRgamma chain and syk kinase was detected in FcalphaR(+) and FcalphaR(+)/gamma(+) cells, but not in untransfected cells. Aggregated IgA induced significantly higher MCP-1 production in FcalphaR(+)/gamma(+) than those in FcalphaR(+) or untransfected control.

CONCLUSIONS

Present study demonstrated that FcalphaR and FcRgamma chain could be reconstituted in mesangial cells and mediated MCP-1 production by aggregated IgA in a dose-dependent manner. Current data would argue that FcalphaR can be activated in mesangial cells through their own machinery, although underlying mechanisms for FcalphaR induction in mesangial cells remain unclear.

Protein localization and mRNA expression of epimorphin in mouse and human kidneys

Epimorphin is a mesenchymal cell surface protein which induces epithelial branching morphogenesis. However, the role of epimorphin in the kidney has not been addressed. In the present study, the localization of epimorphin protein and the expression of its mRNA were investigated in the developing mouse and adult human kidneys using immunohistochemistry and semiquantitative RT-PCR. The in vitro expression of epimorphin protein and its mRNA was also explored in cultured mouse and human mesangial cells. Epimorphin protein was expressed in the renal interstitium and the circumference of the comma-shaped body at day 16 of gestation. The intensity and distribution of epimorphin were gradually increased during kidney differentiation and maturation. Epimorphin was first observed in glomeruli at 1 week of age. The localization of epimorphin in glomerular mesangial cells and interstitial fibroblasts was confirmed by immunoelectron microscopy of 2-week-old mouse kidneys. The highest mRNA expression of epimorphin was observed at day 16 of gestation, thereafter it diminished with the maturation of the kidney. A similar localization of epimorphin was observed in a normal adult human kidney. Cultured human mesangial cells expressed epimorphin mRNA 150-kD protein. These results suggest that epimorphin may play a role in the development of the kidney and in the differentiation of fibroblast and mesangial cells.

Relationship between mast cells in the tubulointerstitium and prognosis of patients with IgA nephropathy

There have been a few reports suggesting that mast cells may play an important role in the development of fibrosis and/or the degradation of extracellular matrix. We examined the relationship between the number of distribution of mast cells in tubulointerstitium and prognosis of patients with IgA nephropathy. Renal biopsy specimens were stained with mouse monoclonal antihuman mast cell tryptase antibody and then with aniline blue. Specimens from 45 patients with IgA nephropathy and from 5 patients with minimal-change nephrotic syndrome were used. There was a significant correlation between the number of mast cells per unit area of the whole tubulointerstitium and the degree of tubulointerstitial fibrosis or renal function. Patients with IgA nephropathy were divided into two groups (group 1: 'minimal' and 'slight'; group 2: 'moderate' and 'advanced') according to the classification by a previously reported method. Mast cells were mainly observed in the fibrotic areas in group 1. In group 2, many mast cells were detected not only in the fibrotic but also in the nonfibrotic areas. It appears that the number of mast cells in the nonfibrotic areas may be one of the predictive factors for the prognosis of patients with IgA nephropathy.

Podocyte injury predicts prognosis in patients with iga nephropathy using a small amount of renal biopsy tissue

To predict the progression in patients with IgA nephropathy, we analyzed glomerular lesions except for sclerosis, adhesion and/or crescents in 34 patients with this disease by morphometric analysis. Levels of urinary protein excretion (UP), creatinine clearance (Ccr), serum creatinine (sCr) and mean blood pressure (MBP) at the time of renal biopsy were used as the clinical parameters. The slope of 1/sCr was also used as a prognostic parameter. Renal specimens were obtained by echo-guided biopsy. In PAS-stained light microscopic renal sections, three mid sections of open glomeruli were selected and photographed. Stereologic estimation was performed as follows: absolute values of glomerular volume (V(G)), glomerular surface area (S(G)), podocyte and nonpodocyte cell number per glomerulus (N(G(pod)) and N(G(Non-pod))), glomerular surface area covered by one podocyte S(G)/N(G(pod))) and glomerular volume occupied by one nonpodocyte cell (V(G)/N(G(Non-pod))). There was a significant correlation between the levels of UP and the change of podocyte injury parameters (N(G(pod)) and S(G)/N(G(pod))) or N(G(Non-pod)). N(G(pod)) was negatively but S(G)/N(G(pod)) and N(G(Non-pod)) were positively correlated with UP. S(G)/N(G(pod)) or N(G(Non-pod)) was correlated with MBP. N(G(pod)), S(G)/N(G(pod)), N(G(Non-pod)), UP or MBP was significantly correlated with the slope of 1/sCr. High specificity was observed for N(G(pod)), S(G)/N(G(pod)) and MBP. High sensitivity was also observed for N(G(Non-pod)) and UP. It appears that podocyte injury might provide additional prognostic information in patients with IgA nephropathy.

Effect of steroid-liposome on immunohistopathology of IgA nephropathy in ddY mice

Immunopathological studies were performed to determine whether glomerular injuries in ddY mice, a spontaneous animal model for IgA nephropathy, are influenced by treatment with a newly developed liposome loaded with prednisolone phosphate (PSL-liposome). The newly synthesized novel cationic lipid 3,6-dipentadeciroxy-1-amizino-benzene (TRX-20) was employed to obtain selective affinity to the anionic cell surface and extracellular matrices in glomerular mesangial lesions. ddY mice were treated intravenously with 1.0 mg/kg of PSL-liposome once a week for 16 weeks (from 45 weeks to 61 weeks of age). ddY mice were also intravenously treated with 1.0 mg/kg of ordinary PSL once a week for the same duration. On immunofluorescence, depositions of IgA and C3 in the glomerular mesangial areas and capillary walls of PSL-liposome-treated ddY mice were markedly decreased as compared with those of ordinary PSL-treated and untreated control ddY mice. The mean intensity of IgA and C3 in glomeruli of PSL-liposome-treated ddY mice was decreased as compared with that in ordinary PSL-treated and untreated control ddY mice. Glomerular mesangial expansion in PSL-liposome-treated ddY mice was milder than that found in ordinary PSL-treated ddY mice or untreated control ddY mice. It appears that treatment with PSL-liposome is effective in improving glomerular IgA and C3 depositions and glomerular expansion in IgA nephropathy of ddY mice.

[A case of gastric antral vascular ectasia (GAVE) with chronic renal failure]

A 76-year-old woman was admitted to our hospital complaining of tarry stool, general fatigue and marked anemia(Hb 5.2 g/dl). Gastric endoscopic findings showed longitudinal red stripes and diffuse erythematous spots, indicating dilated vascular vessels. They resembled the stripes of a watermelon at the gastric antrum. The marked anemia was caused by chronic blood loss from the abnormally dilated mucosal and submucosal capillary veins in the gastric antrum. She was diagnosed as having gastric antral vascular ectasia(GAVE) with chronic renal failure(CRF). The association of GAVE and CRF is considered to be rare according to previous reports in Japan. Endoscopic argon plasma coagulation therapy was performed three times. After therapy, capillary dilatation disappeared, and the marked anemia was greatly improved. Argon plasma coagulation therapy was found to be a safe and effective procedure for this disease. Although GAVE is essentially a benign gastric disease, endoscopic therapy should be the treatment of first choice for this disease.

Identification of cellular origin of type I collagen in glomeruli of rats with crescentic glomerulonephritis induced by anti-glomerular basement membrane antibody

BACKGROUND

Type I collagen is an interstitial collagen, which is not present in normal glomeruli. As type I collagen was observed in advanced glomerular lesions, it appears to be associated with deterioration of renal function. However, the origins of cells expressing type I collagen mRNA in glomeruli of diseased kidneys remains controversial.

METHODS

We examined the expression of type I collagen in glomeruli at protein and mRNA levels in rat crescentic glomerulonephritis induced by anti-glomerular basement membrane (GBM) antibody. In addition, in situ hybridization and immunohistochemical staining of serial sections were performed to identify the cellular origin of type I collagen in glomeruli.

RESULTS

Semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) in isolated glomeruli showed that mRNA expression of type I collagen was remarkably increased on days 7, 14, and 28 after anti-GBM antibody injection (12.2+/-1.4, 20.2+/-2.1 and 14.6+/-1.0-fold over day 0, respectively). Immunofluorescence for type I collagen demonstrated marked staining in the fibrocellular and fibrous crescents, and weak staining within glomerular mesangial areas. In close association with mRNA levels analysed by RT-PCR, in situ hybridization revealed predominant presence of alpha1(I) collagen mRNA in cells within crescentic areas and Bowman's capsules. Serial section analysis for immunostaining and in situ hybridization showed that some alpha1(I) collagen mRNA-positive cells were also positive for cytokeratin. In contrast, no alpha1(I) collagen mRNA-positive cells were stained by ED-1 and podocalyxin.

CONCLUSIONS

It appears that increased expression of type I collagen at the protein and mRNA levels in glomeruli is involved in the progression of glomerulonephritis. At least in this crescentic model, parietal epithelial cells (PECs) may partially contribute to the dysregulated production of type I collagen, which leads to glomerulosclerosis.

Urinary levels of interleukin-8 (IL-8) and disease activity in patients with IgA nephropathy

Using quantitative sandwich ELISA, we studied 27 patients with IgA nephropathy to determine whether the levels of urinary IL-8 might reflect the disease activity. The levels of urinary IL-8 in patients with advanced stage IgA nephropathy were significantly higher than those in the patients with the mild stage of this disease, or in the healthy controls. The results showed a positive significant correlation between the levels of IL-8 and disease activity, i.e., between levels of urinary protein and urinary casts. A significant correlation between levels of urinary IL-8 and tubular function damage was also found. It was thus suggested that measurement of urinary IL-8 might be useful in evaluating the degree of renal injuries and/or prognosis in patients with IgA nephropathy.

Polymorphism in promoter region of Fcalpha receptor gene in patients with IgA nephropathy

We have recently identified two novel polymorphisms (-114T/C and +56T/C relative to the major transcription start site) in the functional promoter region of the Fcalpha receptor (FcalphaR) gene. Since altered FcalphaR expression may be associated with IgA nephropathy, we examined these promoter polymorphisms in this disease. Patients with IgA nephropathy (n = 90), patients with other primary glomerulonephritis (n = 50), and healthy adults (n = 83) were studied. Genotyping was performed by the polymerase chain reaction (PCR) followed by direct sequence analysis and was subsequently confirmed by PCR with mismatched primers followed by restriction fragment length polymorphism analysis. The study demonstrated that the frequency of the +56C allele in patients with IgA nephropathy (0.511) was significantly (P < 0.01) higher than that in patients with other primary glomerulonephritis (0.350) and healthy adults (0.337). In addition, a significant increase in the frequency of the +56CC genotype was observed in patients with IgA nephropathy (27.8% vs 10.0% in other GN and vs 9.6% in healthy adults). In contrast, no significant difference in the frequencies of the +56CC genotype and +56C allele was observed between other primary glomerulonephritis patients and healthy adults. The frequency of the -114CC genotype in patients with IgA nephropathy was significantly increased compared with those in both control groups (15.6% vs 4.0% in other GN and vs 2.4% in healthy adults). Polymorphisms of the FcalphaR promoter region therefore appear to be associated with susceptibility to IgA nephropathy, suggesting the importance of the FcalphaR gene and its expression in this disease.

Serum cystatin C may predict the prognostic stages of patients with IgA nephropathy prior to renal biopsy

The relationship between the levels of serum cystatin C and the prognostic stages of IgA nephropathy was determined in a multicenter trial in Japan. The levels of serum cystatin C in patients with IgA nephropathy were measured using the Dade Behring N Latex Cystain C assay. In 1995, the Joint Committee of the Special Study Group on Progressive Glomerular Diseases, Ministry of Health and Welfare of Japan, and the Japanese Society of Nephropathy reported four prognostic stages. These are: good prognosis group (Group I), relatively good prognosis group (Group II), relatively poor prognosis group (Group III), and poor prognosis group (Group IV), for this disease. Three-hundred and six patients with IgA nephropathy and other glomerular diseases were examined. There were no significant changes in the levels of serum creatinine (Cr) or creatinine clearance (CCr) between Group I and Group II. The mean levels of serum cystatin C in Group II were significantly higher than those in Group I (P < 0.05). The mean levels of serum cystatin C in Group III or IV were significantly higher than those in Group I (P < 0.001, P < 0.005, respectively). These suggest that the measurement of serum cystatin C may predict the prognostic stages of patients with IgA nephropathy prior to renal biopsy.

[A 62-year-old patient with congenital coronary arteriovenous fistula demonstrating dilatation and contortion that corresponded to the aorta in thickness: a case report]

A 62-year-old female, cardiac echography and catheterization revealed against aneurysming right coronary arteriovenous fistula. To avoid rupture of the aneurysm, the right coronary orifice was closed. Subsequently, the arteriovenous fistula orifice adjacent to the coronary venous sinus was closed. In addition, to avoid transfer of a thrombus in the aneurysm to the RCA, suture ligature of the right coronary aneurysm was performed, and surgery was completed. The postoperative course was uneventful. Postoperative heart catheterization showed good collateral blood circulation from the LAD to the RCA.

[A surgical case of abdominal aortic aneurysm accompanied by hamartomatous changes in the vascular wall]

The current patient was a 22-year-old woman with dyspnea on exertion that had exacerbated over the past two to three years. Chest X-ray indicated pneumothorax in the right lung, and chest computed tomography showed diffuse microcysts in both lungs. The patient was diagnosed with lymphangiomyomatosis based on pleural biopsy by intrathoracic endoscopy. Systemic testing revealed complications of tuberous sclerosis and abdominal aortic aneyrysm, and a prosthetic graft replacement was perfomed following pneumothorax treatment. Aortic wall tissue images showed hamartomatous changes in smooth muscle tissue, similar to the pulmonary lesion, and this was thought to have caused vascular fragility and aneurysmal change.

Detection of apoptotic cells in glomeruli of patients with IgA nephropathy

The purpose of the present study was to determine the relationship between the existence of apoptotic cells in glomeruli, clinical or histopathological findings and response to treatment in patients with IgA nephropathy. Renal biopsy specimens were obtained from 23 patients with IgA nephropathy. These patients were divided into two groups: mild glomerular damage (12 patients), and severe glomerular damage (11 patients). The nick end-labelling method (TUNEL) and fluorescent staining (Hoechst 33258) were used for the detection of apoptotic cells. Five of 6 patients with apoptotic cells in the glomeruli detected by TUNEL were in the severe glomerular damage group, and only 1 patient was in the mild glomerular damage group. Apoptotic cells in glomeruli were also detected by fluorescent staining in 3 of 5 patients in the severe glomerular damage group who showed apoptotic cells in TUNEL. However, no apoptotic cells were detected in patients in the mild glomerular damage group in fluorescent staining. Mean levels of urinary protein excretion at the time of renal biopsy in the patients with apoptotic cells were significantly higher than those in patients without apoptotic cells (p < 0.01). The mean levels of creatinine clearance (Ccr) in the patients with apoptotic cells were slightly lower than those in patients without such cells. There were no significant differences in the levels of serum creatinine (s-Cr) and BUN in patients with or without apoptotic cells. In the severe glomerular damage group, urinary protein excretion after treatment in the patients with apoptotic cells was significantly improved compared with that in the patients without such cells (p < 0.01). It appears that the levels of proteinuria and renal function tests might be influenced by apoptosis in patients with IgA nephropathy. It is postulated that apoptosis may induce reduction of excess proliferative mesangial cells and/or infiltrated cells, and tissue repair. Thereafter, these histological alterations may improve proteinuria and renal function.

Abnormal distribution of mesangium-specific laminin in glomeruli of patients with idiopathic membranous nephropathy

Using a monoclonal antibody, the distribution of the mesangium-specific laminin that binds only to the mesangium in normal kidney, was studied immunohistochemically in renal tissues obtained from patients with different glomerulonephritides including idiopathic membranous nephropathy. In minimal change nephrotic syndrome and IgA nephropathy, the mesangium-specific laminin staining was restricted to the mesangium, as is observed in the normal kidney. However, in patients with idiopathic membranous nephropathy, the monoclonal antibody against the mesangium-specific laminin reacted with the glomerular peripheral capillary walls including subepithelial protrusions or 'spikes', as well as with the mesangium. These results suggest that the quality of laminin produced in response to the challenge of immune deposits in the peripheral capillary walls may be different from that in the rest of the glomerular basement membrane in idiopathic membranous nephropathy.

Photooxidation mechanism of nitrogen-containing compounds at TiO2/H2O interfaces: an experimental and theoretical examination of hydrazine derivatives

The photocatalytic oxidation of oxalyldihydrazide, N,N'-bis(hydrazocarbonyl)hydrazide, N,N'-bis(ethoxycarbonyl)hydrazide, malonyldihydrazide, N-malonyl-bis[(N'-ethoxycarbonyl)hydrazide] was examined in aqueous TiO2 dispersions under UV illumination. The photomineralization of nitrogen and carbon atoms in the substrates into N2 gas, NH4+ (and/or NO3-) ions, and CO2 gas was determined by HPLC and GC analysis. The formation of carboxylic acid intermediates also occurred in the photooxidation process. The photocatalytic mechanism is discussed on the basis of the experimental results, and with molecular orbital (MO) simulation of frontier electron density and point charge. Substrate carbonyl groups readily adsorb on the TiO2 surface, and the bonds between carbonyl group carbon atoms and adjacent hydrazo group nitrogen atoms are cleaved predominantly in the initial photooxidation process. The hydrazo groups were photoconverted mainly into N2 gas (in mineralization yields above 70%) and partially to NH4 ions (below 10%). The formation of NO3- ions was scarcely recognized.

Low-capacity cation-exchange chromatography of ultraviolet-absorbing urinary basic metabolites using a reversed-phase column coated with hexadecylsulfonate

A low-capacity cation-exchange HPLC method for the determination of UV-absorbing organic cations such as amino acids, histidine dipeptides, and creatinine was developed. A commercially available reversed-phase column was dynamically coated with hexadecylsulfonate, and was successfully used for the cation-exchange separation with ethylenediammonium eluting ion at pH 2.5. The coated column was enough stable for the specific use with a completely aqueous mobile phase at low and constant pH; and the day-to-day reproducibility for retention time was 0.9-1.7% of RSD (relative standard deviation). The linear relation between concentrations and detector responses (area) by using a photodiode-array UV detection at 210 nm ranged from 0.2 to 1000 microM (sample size 50 microl) for 1-methylhistidine, 3-methylhistidine, histidine, creatinine, anserine, carnosine, and homocarnosine, and from 0.5 to 2000 microM for creatine, tyrosine, and phenylalanine, with less than 5% of RSD. The UV spectrum (190-300 nm) obtained during chromatography was very indicative for each analyte. Overall recoveries were 97-104%. The developed HPLC method in conjunction with preliminary fractionation technique could be applied to the analysis of urine of patient with metabolic disorder such as phenylketonuria.

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.

[Aortocaval fistula with acute right heart failure during surgery: case report]

A 71-year-old man was transferred to our institution with suspected of impending rupture of the abdominal aorta. The clinical manifestations included abdominal pain, pulsatile mass, and abdominal bruit. We made on early diagnosis of aortocaval fistula based on enhanced computed tomography and color Doppler flow imaging. Surgical repair was performed 24 hours after the onset of symptoms. At the introduction of anesthesia, cardiac arrest with high central venous pressure occurred. After resuscitation and rapid clamping of the proximal aorta, surgical closure of the fistula with graft replacement was performed successfully.