Faculty Profiles - KAWACHI Hiroshi

Attenuation of mouse acute colitis by naked hepatocyte growth factor gene transfer into the liver Reviewed

T Hanawa, K Suzuki, Y Kawauchi, M Takamura, H Yoneyama, GD Han, H Kawachi, F Shimizu, H Asakura, J Miyazaki, H Maruyama, Y Aoyagi

JOURNAL OF GENE MEDICINE 8 ( 5 ) 623 - 635 2006.5

Language：English Publishing type：Research paper (scientific journal) Publisher：JOHN WILEY & SONS LTD

Background Hepatocyte growth factor (HGF) has multiple biological effects on a wide variety of cells. It modulates intestinal epithelial proliferation and migration, and critically regulates intestinal wound healing. Aims To investigate the therapeutic effect of HGF gene transfer, we introduced the HGF gene into the liver of mice with acute colitis. Methods The rat HGF expression plasmid vector, pCAGGS-HGF, was injected via the tail vein into C57BL/6 mice, followed by dosing with dextran sulfate sodium in distilled water. Firstly, the HGF gene was injected once on day 0. Secondly, the HGF gene was injected on day 0 and again on day 2. Results Injection of the HGF gene ameliorated colitis with inhibition of both loss of body weight and shortening of colon length. It protected the colon from epithelial erosions and cellular infiltration. Expression of mRNAs for IFN-gamma, IL18, and TNF-alpha was reduced in the colon. In contrast, expression of mRNA for IL-10 was increased. The numbers of BrdU-positive intestinal epithelial cells were increased, and the numbers of TUNEL-positive apoptotic cells were decreased. Furthermore, a second injection prolonged the elevation of serum HGF levels, and ameliorated the symptoms better than a single injection. The empty pCAGGS plasmid did not ameliorate acute colitis. Conclusions HGF gene transfer attenuated acute colitis by facilitating intestinal wound repair as well as inhibiting inflammation, suggesting a new strategy for treatment of IBD. Copyright (c) 2006 John Wiley & Sons, Ltd.

DOI： 10.1002/jgm.880

Antagonism of PDGF-D by human antibody CR002 prevents renal scarring in experimental glomerulonephritis Reviewed

Tammo Ostendorf, Song Rong, Peter Boor, Stefanie Wiedemann, Uta Kunter, Ulrike Haubold, Claudia R. C. van Roeyen, Frank Eitner, Hiroshi Kawachi, Gary Starling, Enrique Alvarez, Glennda Smithson, Juergen Floege

JOURNAL OF THE AMERICAN SOCIETY OF NEPHROLOGY 17 ( 4 ) 1054 - 1062 2006.4

Language：English Publishing type：Research paper (scientific journal) Publisher：AMERICAN SOCIETY NEPHROLOGY

Glomerular mesangial cell proliferation and/or matrix accumulation characterizes many progressive renal diseases. PDGF-D was identified recently as a novel mediator of mesangial cell proliferation in vitro and in vivo. This study investigated the long-term consequences of PDGF-D inhibition in vivo. Rats with progressive mesangioproliferative glomerulonephritis (uninephrectomy plus anti-Thy-1.1 antibody) received the PDGF-D-neutralizing, fully human mAb CR002 on days 3, 10, and 17 after disease induction. Glomerular mesangioproliferative changes on day 10 were significantly reduced by anti-PDGF-D treatment as compared with control antibody. Eight weeks after disease induction, anti-PDGF-D therapy significantly ameliorated focal segmental glomerulosclerosis, podocyte damage (de novo desmin expression), tubulointerstitial damage, and fibrosis as well as the accumulation of renal interstitial matrix including type III collagen and fibronectin. Treatment with anti-PDGF-D also reduced the cortical infiltration of monocytes/macrophages on day 56, possibly related to lower renal cortical complement activation (C5b-9 deposition) and/or reduced epithelial-to-mesenchymal transition (preserved cortical expression of E-cadherin and reduced expression of vimentin and a-smooth muscle actin). In conclusion, these data provide evidence for a causal role of PDGF-D in the pathogenesis of renal scarring and point to a new therapeutic approach to progressive mesangioproliferative renal disease.

DOI： 10.1681/ASN.2005070683

Exogenous 5′-nucleotidase improves glomerular autoregulation in Thy-1 nephritic rats Reviewed

Tsuneo Takenaka, Hirokazu Okada, Yoshihiko Kanno, Tsutomu Inoue, Munekazu Ryuzaki, Hidetomo Nakamoto, Hiroshi Kawachi, Fujio Shimizu, Hiromichi Suzuki

American Journal of Physiology - Renal Physiology 290 ( 4 ) F844 - F853 2006.4

Language：English Publishing type：Research paper (scientific journal)

Experiments were performed to characterize renal hemodynamics in Thy-1 nephritic rats. A monoclonal antibody against Thy-1 was intravenously injected to induce mesangiolysis in rats, and 2 days later renal hemodynamic responses to variations in blood pressure were determined. In the first series of experiments, autoregulation of renal plasma flow (RPF) or glomerular filtration rate (GFR) was impaired in nephritic rats. In response to a reduction in blood pressure (98 ± 2 to 80 ± 1 mmHg), both RPF (4.17 ± 0.63 to 3.20 ± 0.45 ml·min-1·g kidney wt-1, P &lt
0.05, n = 6) and GFR (0.88 ± 0.05 to 0.75 ± 0.06 ml·min-1·g kidney wt-1, P &lt
0.05) were decreased in nephritic rats. Intravenous administration of furosemide and 30% albumin, both of which inhibit tubuloglomerular feedback, diminished renal autoregulation in control but not nephritic rats. In the second studies, the infusion of 5′-nucleotidase, an enzyme expressed on mesangial cells, into a renal artery ameliorated the magnitude of autoregulatory decrements in GFR in nephritic rats (-16 ± 5 to -6 ± 2%, P &lt
0.05, n = 6), but this enzyme failed to alter renal autoregulation in control rats. In the third studies, the effects of indomethacin were examined in nephritic rats. Inhibition of prostaglandin synthesis reduced RPF (4.07 ± 0.30 to 1.54 ± 0.22 ml·min-1·g kidney wt-1, P &lt
0.05, n = 5) and GFR (1.03 ± 0.18 to 0.69 ± 0.13 ml·min-1·g kidney wt-1, P &lt
0.05) in nephritic rats. However, cyclooxygenase inhibition failed to restore renal autoregulation in nephritic rats. Our results indicate that renal autoregulation is impaired in Thy-1 nephritis. Furthermore, the present data provide evidence that prostanoids contribute to maintain renal circulation in nephritic rats. Finally, our findings suggest that mesangial cells and/or 5′-nucleotidase plays an important role in mediating renal autoregulation. Copyright © 2006 the American Physiological Society.

DOI： 10.1152/ajprenal.00112.2005

Microarray analysis of a reversible model and an irreversible model of anti-Thy-1 nephritis Reviewed

M Tsuji, T Monkawa, J Yoshino, M Asai, S Fukuda, H Kawachi, F Shimizu, M Hayashi, T Saruta

KIDNEY INTERNATIONAL 69 ( 6 ) 996 - 1004 2006.3

Language：English Publishing type：Research paper (scientific journal) Publisher：NATURE PUBLISHING GROUP

A single intravenous injection of anti-Thy-1 monoclonal antibody (mAb) 1-22-3 is known to cause reversible mesangial proliferative glomerulonephritis. However, mAb 1-22-3 injection followed by unilateral nephrectomy leads to progressive glomerulosclerosis and tubulointerstitial change with an irreversible course. To identify genes that play an important role in the irreversible progression of renal injury, we used microarray technology to identify differences in gene expression between these models. Rats were intravenously injected with mAb 1-22-3 1 week after unilateral nephrectomy (irreversible model) or a sham operation (reversible model), and rats were killed on days 4, 7, 14, 42, and 56 after the injection. complementary DNA probes prepared from kidney messenger RNAs were hybridized with oligonucleotide microarrays containing 4854 rat genes. The microarray identified 189 differentially expressed genes, having at least a two-fold difference in expression level between the two models, and they were classified into five clusters. One of the clusters consisted of genes whose expression was markedly upregulated in the irreversible model. This cluster included the genes encoding osteopontin, kidney injury molecule-1, and thymosin beta 10. Increased expression of thymosin beta 10 was localized mainly in macrophages in the fibrotic interstitium, and upregulation of thymosin beta 10 expression was also observed in a unilateral ureteral obstruction model. The microarray analysis yielded information on the molecular mechanisms responsible for the difference in disease progression between the reversible and irreversible model of anti-Thy-1 nephritis. Thymosin beta 10 may play an important role in the progression of kidney disease.

DOI： 10.1038/sj.ki.5000191

Up-regulation of integrin-linked kinase activity in rat mesangioproliferative glomerulonephritis Reviewed

S Kagami, M Shimizu, S Kondo, A Kitamura, M Urushihara, M Takamatsu, S Yamaji, Y Ishigatsubo, H Kawachi, F Shimizu

LIFE SCIENCES 78 ( 16 ) 1794 - 1800 2006.3

Language：English Publishing type：Research paper (scientific journal) Publisher：PERGAMON-ELSEVIER SCIENCE LTD

This study investigated whether integrin-linked kinase (ILK) is involved in the pathogenesis of chronic glomerulonephritis (GN) by analyzing the expression and activity of glomerular ILK in a chronic rat model of mesangioproliferative GN. Double immunostaining of kidneys obtained at different time points with glomerular cell-specific markers revealed that ILK was primarily expressed by glomerular epithelial cells, and weakly by mesangial cells (MCs) and endothelial cells in control rats, but dramatically increased in a typical mesangial pattern at days 21 and 28 of GN. Semiquantitative assessment indicated that the level of glomerular ILK expression closely parallels the level of accumulation of glomerular extracellular matrix (ECM) as well as fibronectin (FN). Immunoprecipitation and kinase activity assays using isolated nephritic glomeruli indicated a striking increase of ILK activity on days 21 and 28 of GN. Further, cultured rat MCs overexpressing kinase-deficient ILK diminished FN assembly and collagen matrix remodeling as compared with control transfectants. The results showed that glomerular ILK expression and activity are markedly increased in an experimental model of chronic GN. Increased activity of ILK in MCs may contribute to the development of chronic mesangial alterations leading to glomerular sear-ring. (c) 2005 Elsevier Inc. All rights reserved.

DOI： 10.1016/j.lfs.2005.08.037

Addition of the antioxidant probucol to angiotensin II type I receptor antagonist arrests progressive mesangioproliferative glomerulonephritis in the rat Reviewed

Shuji Kondo, Maki Shimizu, Maki Urushihara, Koichiro Tsuchiya, Masanori Yoshizumi, Toshiaki Tamaki, Akira Nishiyama, Hiroshi Kawachi, Fujio Shimizu, Mark T. Quinn, David J. Lambeth, Shoji Kagami

JOURNAL OF THE AMERICAN SOCIETY OF NEPHROLOGY 17 ( 3 ) 783 - 794 2006.3

Language：English Publishing type：Research paper (scientific journal) Publisher：AMERICAN SOCIETY NEPHROLOGY

Angiotensin II (Ang II) and reactive oxidative species (ROS) that are produced by NADPH oxidase have been implicated in the progression of glomerulonephritis (GN). This study examined the effect of simultaneously interrupting Ang 11 and ROS with an Ang II receptor blocker (ARB), candesartan, and a free radical scavenger, probucol, in a model of progressive mesangioproliferative GN induced by the injection of anti-Thy-1 antibody into uninephrectomized rats. Nephritic rats were divided into four groups and given daily oral doses of the following: Vehicle, 1% probucol diet, 70 mg/L candesartan in drinking water, and probucol plus candesartan. These treatments lasted until day 56. Vehicle-treated nephritic rats developed progressively elevated proteinuria and glomerulosclerosis. Candesartan kept proteinuria significantly lower than vehicle or probucol. The addition of probucol to candesartan normalized urinary protein excretion. Increases in BP in nephritic rats were lowered by these treatments, except with probucol. It is interesting that both glomerular cell number and glomerulosclerosis were significantly decreased by candesartan and normalized by the addition of probucol. Immunohistochemical studies for TGF-beta 1, collagen type I, and fibronectin revealed that the combined treatment abolished glomerular fibrotic findings compared with candesartan. In addition, glomerular expression of NADPH oxidase components and superoxide production suggested that the combined treatment completely eliminated NADPH oxidase-associated ROS production. In conclusion, our study provides the first evidence that the antioxidant probucol, when added to an Ang II receptor blockade, fully arrests proteinuria and disease progression in GN. Furthermore, the data suggest that NADPH oxidase-associated ROS production may play a pivotal role in the progression of GN. The combination of probucol and candesartan may represent a novel route of therapy for patients with progressive GN.

DOI： 10.1681/ASN.2005050519

IFN-inducible protein-10 plays a pivotal role in maintaining slit-diaphragm function by regulating podocyte cell-cycle balance Reviewed

Gi Dong Han, Koichi Suzuki, Hiroko Koike, Kenji Suzuki, Hiroyuki Yoneyama, Shosaku Narumi, Fujio Shimizu, Hiroshi Kawachi

JOURNAL OF THE AMERICAN SOCIETY OF NEPHROLOGY 17 ( 2 ) 442 - 453 2006.2

Language：English Publishing type：Research paper (scientific journal) Publisher：AMERICAN SOCIETY NEPHROLOGY

IFN-inducible protein-10 (IP-10/CXCL10) is a potent chemoattractant for activated T lymphocytes and was reported recently to have several additional biologic activities. In this study, the pathophysiologic role of IP-10 in the glomerular visceral epithelial cell (podocyte) was investigated. In cultured podocytes subjected to recombinant IP-10 treatment, the expression of slit-diaphragm (SD) components nephrin and podocin clearly was heightened. Rats that had puromycin aminonucleoside nephropathy and anti-nephrin antibody-induced nephropathy and were subjected to anti-IP-10 function-blocking antibody (anti-IP-10 mAb) treatment displayed a decrease in the protein level of SD components, as well as exacerbated proteinuria. For exploration of the mechanisms of this process, the interaction between IP-10 and the cell-cycle regulatory proteins was investigated. Cultured podocytes subjected to recombinant IP-10 treatment displayed an increase in the protein level of P-27Kip1, whereas the levels of cyclins E and A decreased. The expression of IP-10 and SD components was heightened by the treatment of siRNA of cyclin A, whereas these expressions were lowered by the treatment of siRNA of p(27Kip1). Proteinuric rats subjected to anti-IP-10 mAb treatment displayed a heightened expression of cyclin A from the early phase of the disease, which indicates that the anti-IP-10 mAb treatment exacerbates podocyte injury by disturbing the cell-cycle balance. These results raise the possibility that IP-10 could become a novel therapeutic target in nephrotic syndrome and several diseases with altered cell-cycle balance.

DOI： 10.1681/ASN.2004090755

Altered expression of junctional adhesion molecule 4 in injured podocytes Reviewed

Yutaka Harita, Naoko Miyauchi, Tamaki Karasawa, Koichi Suzuki, Dong Han Gi, Hiroko Koike, Takashi Igarashi, Fujio Shimizu, Hiroshi Kawachi

American Journal of Physiology - Renal Physiology 290 ( 2 ) F335 - F344 2006.2

Language：English Publishing type：Research paper (scientific journal)

Recent investigations have revealed the importance of glomerular podocytes with its diaphragm as the major filtration barrier. Junctional adhesion molecule 4 (JAM4) has been identified as a protein that interacts with membrane-associated guanyl kinase inverted (MAGI)-1 and is reported to be expressed on podocytes. To elucidate the role of JAM4 on podocytes, we examined the expression of JAM4 and MAGI-1 in normal and two different proteinuric rat models: puromycin aminonucleoside (PAN) nephropathy and anti-nephrin antibody-induced (ANA) nephropathy, one model with and one without effacement of podocyte foot processes. JAM4 was detected by immunomicroscopy at the apical membrane of normal podocytes. JAM4 immunostaining was focally increased in the podocytes in PAN nephropathy but not in ANA nephropathy. In proteinuric podocytes, the expression of JAM4 was distinct from that of MAGI-1 or other slit diaphragm molecules such as nephrin and ZO-1. Close colocalization of JAM4 and ezrin was maintained in PAN nephropathy. By immunoelectron microscopy, the signals for JAM4 were detected at the free apical membrane of the podocytes with effaced foot processes. Studies with selective detergent extract revealed that the subcellular localization of JAM4 was altered in PAN nephropathy. Thus the altered expression of JAM4 appears to be associated with morphological changes in podocytes and can be a useful marker of injured podocytes. JAM4 may have a different role at the apical membrane besides the role as a junctional molecule and is likely associated with the unique structure of this epithelium. Copyright © 2006 the American Physiological Society.

DOI： 10.1152/ajprenal.00253.2005

Pathophysiologic implications of reduced podocyte number in a rat model of progressive glomerular injury Reviewed

D Macconi, M Bonomelli, A Benigni, T Plati, F Sangalli, L Longaretti, S Conti, H Kawachi, P Hill, G Remuzzi, A Remuzzi

AMERICAN JOURNAL OF PATHOLOGY 168 ( 1 ) 42 - 54 2006.1

Language：English Publishing type：Research paper (scientific journal) Publisher：AMER SOC INVESTIGATIVE PATHOLOGY, INC

Changes in podocyte number or density have been suggested to play an important role in renal disease progression. Here, we investigated the temporal relationship between glomerular podocyte number and development of proteinuria and glomerulosclerosis in the male Munich Wistar Fromter (MWF) rat. We also assessed whether changes in podocyte number affect podocyte function and focused specifically on the slit diaphragm-associated protein nephrin. Age-matched Wistar rats were used as controls. Estimation of podocyte number per glomerulus was determined by digital morphometry of WT1-positive cells. MWF rats developed moderate hypertension, massive proteinuria, and glomerulosclerosis with age. Glomerular hypertrophy was already observed at 10 weeks of age and progressively increased thereafter. By contrast, mean podocyte number per glomerulus was lower than normal in young animals and further decreased with time. As a consequence, the capillary tuft volume per podocyte was more than threefold increased in older rats. Electron microscopy showed important changes in podocyte structure of MWF rats, with expansion of podocyte bodies surrounding glomerular filtration membrane. Glomerular nephrin expression was markedly altered in MWF rats and inversely correlated with both podocyte loss and proteinuria. Our findings suggest that reduction in podocyte number is an important determinant of podocyte dysfunction and progressive impairment of the glomerular permselectivity that lead to the development of massive proteinuria and ultimately to renal scarring.

DOI： 10.2353/ajpath.2006.050398

Enhancing cGMP in experimental progressive renal fibrosis: Soluble guanylate cyclase stimulation vs. phosphodiesterase inhibition Reviewed

Yingrui Wang, Stephanie Krämer, Tanja Loof, Sebastian Martini, Susanne Kron, Hiroshi Kawachi, Fuijo Shimizu, Hans-H. Neumayer, Harm Peters

American Journal of Physiology - Renal Physiology 290 ( 1 ) F167 - F176 2006.1

Language：English Publishing type：Research paper (scientific journal)

cGMP serves as the main second messenger of nitric oxide (NO). Antifibrotic effects of enhancing renal cGMP levels have recently been documented in experimental acute anti-Thy-1 glomerulonephritis. The present study compares the effects of the cGMP production-increasing soluble guanylate cyclase (sGC) stimulator BAY 41-2272 with those of the cGMP degradation-limiting phosphodiesterase inhibitor pentoxifylline (PTX) in a progressive model of renal fibrosis. At 1 wk after induction of anti-Thy-1-induced chronic glomerulosclerosis (cGS), rats were randomly assigned to groups as follows: cGS, cGS + BAY 41-2272 (10 mg·kg body wt-1·day -1), or cGS + PTX (50 mg·kg body wt -1·day-1). BAY 41-2272 and PTX reduced systolic blood pressure significantly. At 16 wk, tubulointerstitial expressions of sGC mRNA and NO-induced cGMP synthesis were increased in untreated cGS animals, whereas their glomerular activity was depressed compared with normal controls. Tubulointerstitial and glomerular cGMP production in response to NO were significantly enhanced in animals treated with BAY 41-2272, but not in those treated with PTX. BAY 41-2272 administration resulted in marked reductions of glomerular and tubulointerstitial histological matrix accumulation, expression of TGF-β1 and fibronectin, macrophage infiltration, and cell proliferation as well as improved renal function. In contrast, only moderate and nonsignificant renoprotective changes were observed in the cGS + PTX group. In conclusion, increasing renal cGMP production through BAY 41-2272 significantly improved renal NO-cGMP signaling and limited progression in anti-Thy-1-induced chronic renal fibrosis, whereas inhibition of cGMP degradation by PTX was only moderately effective. The findings indicate that pharmacological enhancement of renal cGMP levels by sGC stimulation represents a novel and effective antifibrotic approach in progressive kidney disorders. Copyright © 2006 the American Physiological Society.

DOI： 10.1152/ajprenal.00197.2005

The sialoadhesin (CD169) expressing a macrophage subset in human proliferative glomerulonephritis Reviewed

Y Ikezumi, T Suzuki, S Hayafuji, S Okubo, DJ Nikolic-Paterson, H Kawachi, F Shimizu, M Uchiyama

NEPHROLOGY DIALYSIS TRANSPLANTATION 20 ( 12 ) 2704 - 2713 2005.12

Language：English Publishing type：Research paper (scientific journal) Publisher：OXFORD UNIV PRESS

Background. Sialoadhesin ( Sn; CD169) is a lectin-like receptor whose expression is restricted to subsets of tissue and inflammatory macrophages. We have previously identified accumulation of Sn+ macrophages as an important marker of disease progression versus remission in rat mesangial proliferative nephritis. The current study examined the significance of Sn+ macrophages in human proliferative glomerulonephritis.
Methods. Frozen kidney sections from normal adult human kidney ( n = 4) and pediatric nephropathy ( n 40) were stained for total macrophages ( CD68+ cells), Sn+ macrophages, CD3+ T-cells and collagen type I by immunofluorescence. Leukocyte infiltration and the severity of glomerular lesions and interstitial damage were scored. A second protocol biopsy was performed in 27 cases and clinical and biopsy-based data obtained.
Results. Sn+ macrophages were absent from glomeruli in normal adult human kidney and in thin basement membrane disease ( n = 4), but were detected in 4 of 9 cases of purpura nephritis; 7 of 17 IgA nephropathy; 5 of 5 membranoproliferative glomerulonephritis, and 5 of 5 lupus nephritis. Sn+ macrophages were localized in areas of focal glomerular and interstitial damage. Two-colour immunostaining confirmed that Sn+ cells are a subset of total CD68+ macrophages. The number of glomerular Sn+ macrophages correlated with the degree of proteinuria and glomerular lesions ( r = 0.44, P = 0.0045 and r = 0.82, P < 0.0001; respectively), while interstitial Sn+ macrophages correlated with the degree of proteinuria and interstitial damage ( r = 0.59, P < 0.0001 and r = 0.75, P < 0.0001; respectively). Combined immunostaining revealed that interstitial Sn+ macrophages and CD3+ T-cells co-localized in areas of tubulointerstitial damage with increased type I collagen deposition. There was significant correlation between the number of interstitial Sn+ macrophages and CD3+ T-cells ( r = 0.74, P < 0.0001). Most patients responded to a 2 year period of glucocorticoid therapy with a reduction in proteinuria and glomerular lesions and this correlated with the reduction in the number of glomerular Sn+ macrophages.
Conclusion. This study has identified Sn+ cells as a macrophage subset whose accumulation in the kidney correlates with proteinuria and histologic damage. These results, together with recent findings from animal studies, suggest that Sn+ macrophages may play an important role in progressive renal disease.

DOI： 10.1093/ndt/gfi105

注目される腎関連蛋白5 catenin. Invited

河内裕, 張田豊

腎と透析 58 394 - 396 2005.12

注目される腎関連蛋白6 ZO-1. Invited

河内裕, 唐澤環

腎と透析 58 398 - 399 2005.12

注目される腎関連蛋白2 nephrin. Invited

河内裕, 鈴木浩一

腎と透析 58 118 - 119 2005.12

注目される腎関連蛋白3 αactinin-4 . Invited

河内裕, 宮内直子, 韓基東

腎と透析 58 250 - 254 2005.12

注目される腎関連蛋白13 B7-1 protein(CD80). Invited

河内裕, 韓基東

腎と透析 59 166 - 167 2005.12

腎疾患の展望 2.蛋白尿発症の分子生物学. Invited

河内裕

BIO Clinica 20 11 958 - 964 2005.12

MAGI-1 is a component of the glomerular slit diaphragm that is tightly associated with nephrin Reviewed

S Hirabayashi, H Mori, A Kansaku, H Kurihara, T Sakai, F Shimizu, H Kawachi, Y Hata

LABORATORY INVESTIGATION 85 ( 12 ) 1528 - 1543 2005.12

Language：English Publishing type：Research paper (scientific journal) Publisher：NATURE PUBLISHING GROUP

MAGUK with inverted domain structure-1 (MAGI-1) is a membrane-associated protein with one guanylate kinase, six PSD-95/Dlg-A/ZO-1 (PDZ), and two WW domains and is localized at tight junctions in epithelial cells. MAGI-1 interacts with various proteins and is proposed to function as a scaffold protein. In the previous study, we discovered a MAGI-1-interacting cell adhesion molecule junctional adhesion molecule 4 (JAM4). Both proteins are highly expressed in glomerular podocytes in the kidney and partially colocalized. In this study, we have further searched for a binding partner of MAGI-1 in the kidney through yeast two-hybrid screening and obtained nephrin. Nephrin is a cell adhesion molecule specifically localized at the slit diaphragm between neighboring foot processes of podocytes. Biochemical studies reveal that nephrin directly binds to the middle PDZ domains of MAGI-1 through its carboxyl terminus but does not bind to ZO-1. MAGI-1 forms a tripartite complex with nephrin and JAM4 in vitro. Immunoelectron microscopy shows that the localization of MAGI-1 is restricted to the slit diaphragm, whereas JAM4 is also distributed on apical membranes of podocytes. In puromycin aminonucleoside-induced nephrotic podocytes, MAGI-1 is localized with nephrin at the displaced slit diaphragm. These data indicate that MAGI-1 is a component of the slit diaphragm and tightly interacts with nephrin and JAM4 in vivo. MAGI-1 may play a role in determining the boundary between the apical and the bosolateral domain at the level of slit diaphragm.

DOI： 10.1038/labinvest.3700347

Monoclonal antibody 1-22-3-induced glomerulonephritis in uninephrectomized rats as a model of progressive renal failure Reviewed

Masayuki Tomita, Hajime Sogabe, Shoko Nakazato, Shunji Nakatsuji, Takahisa Noto, Kaori Hamada, Hiroshi Kawachi, Fujio Shimizu, Masahiko Matsuo, Seitaro Mutoh

Nephrology Dialysis Transplantation 20 ( 11 ) 2358 - 2367 2005.11

Language：English Publishing type：Research paper (scientific journal)

Background. At present, there are few available animal models of progressive renal failure originating from mesangial proliferative glomerulonephritis (GN). In the current study, we examined the usefulness of anti-Thy-1 monoclonal antibody (mAb) 1-22-3-induced GN in uninephrectomized rats as a model of progressive renal failure by analysing the similarities to human disease. Methods. GN was induced by intravenous injection of mAb 1-22-3 into uninephrectomized male Wistar rats. The natural course of the disease was analysed in this model for 47 weeks. The effect of treatment with the angiotensin-converting enzyme inhibitor, captopril, on renal functional outcome was also examined in this model for 23 weeks, beginning from 1 week after antibody injection. Results. Injection of mAb 1-22-3 induced a persistent proteinuria during the entire study period. Animals showed a progressive decline in renal function and 63% died by week 47. Severe glomerular and tubulointerstitial lesions were consistently observed. Treatment with captopril significantly inhibited increases in proteinuria and blood pressure, and attenuated renal injury. Captopril also retarded the progression of renal failure, and decreased mortality. Finally, the level of proteinuria was significantly correlated with the rate of decline in renal function, and the reduction in proteinuria by captopril was accompanied by a slower progression of renal failure. Conclusions. The mAb 1-22-3-induced GN in a uninephrectomized rat model simulates the clinical manifestations of human disease, indicating that this model may be useful for studying progressive renal failure and for investigating new therapeutic strategies against renal failure. © The Author [2005]. Published by Oxford University Press on behalf of ERA-EDTA. All rights reserved.

DOI： 10.1093/ndt/gfi062