Original Paper Nephron 1998;80:434–443
M.S. Razzaque a A. Kumatori b T. Harada c T. Taguchi a a b
c
Second Department of Pathology, Department of Biochemistry, Institute of Tropical Medicine, and Second Department of Medicine, Nagasaki University School of Medicine, Nagasaki, Japan
Accepted: June 18, 1998
Coexpression of Collagens and Collagen-Binding Heat Shock Protein 47 in Human Diabetic Nephropathy and IgA Nephropathy
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Key Words Diabetic nephropathy IgA nephropathy Collagen Heat shock protein 47
Abstract The mechanism of structural changes of the kidney in human diabetic nephropathy (DN) and IgA nephropathy (IgAN) is not yet completely known, but excessive deposition of extracellular matrix (ECM), including various collagens, may be crucial to this process. Heat shock protein (HSP) 47 has been identified as collagen-binding stress protein, shown to have a specific role in the intracellular processing of procollagen molecules during collagen assembly. To determine whether increased deposition of collagens in human DN and IgAN is related to HSP47, we investigated the expression of HSP47 in renal biopsy and autopsy sections obtained from 22 DN and 45 IgAN patients. Five renal biopsy specimens, diagnosed as minor glomerular abnormalities, were simultaneously studied as controls. Monoclonal antibodies specific for HSP47, type III collagen and type IV collagen were used to assess the relative expression of their proteins in paraffin-embedded renal sections by immunohistochemistry. Increased deposition of collagens was closely related to the sclerotic activity of the disease process in DN and IgAN; increased deposition of collagens was often present in relation to a strong expression of HSP47, a stress protein known to regulate collagen synthesis/assembly. By double immunostaining, we found colocalization of collagens and their molecular chaperone HSP47 in the sclerotic glomeruli and tubulointerstitium in DN and IgAN. Our results strongly support a pathologic role for HSP47 in both these diseases and that increased levels of HSP47 may play an important role in the excessive assembly of collagens resulting in glomerulosclerosis and interstitial fibrosis found in DN and IgAN patients. OOOOOOOOOOOOOOOOOOOOOO
Introduction Mesangial matrix expansion, as a result of increased deposition of various types of extracellular matrix, is a prominent feature in chronic progressive glomerular diseases including IgA nephropathy (IgAN), hypertensive nephrosclerosis and diabetic nephropathy (DN) [1–5].
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Histological changes in patients with DN and IgAN range from virtually no abnormality to mesangial cell proliferation with severe glomerulosclerosis and tubulointerstitial
This study was presented in part at the 14th International Congress of Nephrology, Sydney, 1997.
M.S. Razzaque, MBBS, PhD Second Department of Pathology Nagasaki University School of Medicine 1-12-4, Sakamoto, Nagasaki 852 (Japan) E-Mail razzaque@net.nagasaki-u.ac.jp
Table 1. Intensity of HSP47 expression in DN patients Patient No.
Age years
Sex
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 (autopsy) 22 (autopsy)
60 69 53 39 27 56 54 34 48 63 60 27 53 27 76 40 45 25 65 28 69 67
male male female female female female male female male male female male female male male male female male female male female male
Serum Glomerular creatinine damage mg/dl
Tubulointerstitial damage
HSP47 expression glomerulus
tubular epithelial cells
interstitium
0.5 1.7 1.9 1.0 1.1 1.5 0.8 0.8 1.6 1.3 0.8 0.8 0.8 0.7 1.2 1.3 1.9 0.8 0.7 1.1 1.6 1.8
moderate moderate severe focal mild moderate moderate-severe mild moderate moderate mild moderate severe focal mild moderate mild-moderate moderate moderate mild moderate moderate severe moderate
+ ++ ++ + + ++ + ++ ++ ++ ++ ++ + + + ++ ++ ++ ++ ++ ++ ++
+ + ++ + ++ + ++ + + + ++ ++ ++ + + ++ + + ++ ++ + +
+ ++ ++ + ++ + + ++ ++ ++ ++ + + ++ + ++ ++ ++ ++ ++ ++ ++
diffuse nodular nodular diffuse diffuse diffuse nodular diffuse diffuse nodular diffuse diffuse diffuse diffuse diffuse nodular nodular nodular nodular diffuse nodular diffuse
damages. Alterations of the extracellular matrix have been suggested as an important cause of glomerulosclerosis and tubulointerstitial damage in various renal diseases including DN and IgAN. Excessive synthesis of collagens by intrarenal cells with their increased deposition was noted in glomerulosclerosis and tubulointerstitial damage in various renal diseases including DN and IgAN [4, 5]. However, the exact molecular mechanism of excessive accumulation of collagens in these diseases is not fully understood. Recently, a 47-kD heat shock protein (HSP47) was identified as a collagen-binding stress protein and shown to have a specific role in the intracellular processing of procollagen molecules as a collagen-specific molecular chaperone [6–11]. However, possible involvement of HSP47 in relation to sclerosis/fibrosis in human renal diseases is not yet known. In an attempt to elucidate the role of HSP47 in relation to the increased deposition of collagens in DN and IgAN, we investigated the distribution of type III and type IV collagens with their molecular chaperone HSP47 in renal tissues obtained from the patients with DN and IgAN. In addition, the relation between
HSP47-expressing cells and phenotypically altered intrarenal cells and/or infiltrating macrophages was also studied.
HSP47 Expression in Human Renal Diseases
Nephron 1998;80:434–443
Materials and Methods Patients Renal samples obtained from 22 patients with various histological stages of DN were examined. 20 of these patients have undergone renal biopsy; two samples were collected during autopsy. In addition, renal biopsy tissues from 45 cases of IgAN were also studied. The renal tissues were histologically examined at the Second Department of Pathology of the Nagasaki University School of Medicine and diagnosed as DN and IgAN. Five renal biopsy specimens diagnosed as minor glomerular abnormalities were included as controls. All the control cases were free from any glomerular and tubulointerstitial damages. The clinical and histological findings of the examined patients are summarized in tables 1 and 2. Renal Specimens For histological diagnosis, the renal specimens were routinely processed by various methods, including light microscopy, immunofluorescence and electron microscopy (EM). Portions of the kidneys were fixed in 10% formalin, processed according to standard proce-
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Table 2. Intensity of HSP47 expression in IgAN patients Patient No.
Age years
Sex
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45
16 16 29 16 50 57 46 17 31 47 20 67 18 19 20 53 24 22 23 39 14 22 36 60 16 45 17 33 22 12 41 29 13 9 18 40 47 17 43 34 37 48 18 34 38
male male male male male male male male male female female female female female female female female female female male male male male male male male male male male female female female female female female male male male male male female female male male male
Serum Glomerular creatinine damage mg/dl
HSP47 intensity glomerulus
tubular epithelial cells
interstitium
0.9 1.1 1.2 0.8 1.1 1.1 1.0 0.8 0.8 0.8 0.8 0.8 0.7 0.8 0.7 1.0 0.9 0.8 1.0 1.2 0.8 1.0 1.1 0.8 0.8 1.1 0.9 1.1 1.0 0.5 0.9 1.0 0.6 0.5 1.0 1.1 1.4 1.1 1.2 1.4 0.9 1.1 0.8 1.9 1.5
++ ++ ++ ++ ++ ++ ++ ++ ++ ++ ++ ++ ++ + + + + + + + + + + + – ++ ++ ++ ++ ++ ++ ++ ++ + + + + ++ ++ ++ ++ ++ + + ++
+ + ++ – + ++ ++ + ++ + – + + + – – + + + – + – – + – – + + + + + + + – – – – + – + + + ++ + +
+ ++ – + ++ ++ + + ++ + + + + – + + + + + ++ + + + + ++ + ++ ++ ++ + + ++ + + ++ + + + + + ++ + + + ++
dures, embedded in paraffin and sectioned at 4 Ìm in thickness. For light microscopy, the sections were stained with periodic acid-Schiff, periodic acid-Schiff-methenamine silver and Masson’s trichrome. Using conventional staining methods for immunofluorescence observation, the frozen sections (4 Ìm) were stained with fluorescein isothiocyanate-labeled antihuman IgG, IgA, IgM, C3, C1q and fibrino-
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mild mild mild mild mild mild mild mild mild mild mild mild mild mild mild mild mild mild mild mild mild mild mild mild mild mild-moderate mild-moderate mild–moderate mild–moderate mild-moderate mild-moderate mild-moderate mild-moderate mild-moderate mild-moderate mild-moderate mild-moderate moderate moderate moderate moderate moderate moderate moderate moderate-severe
IgA staining
B F+ ++ + + F ++ + F++ + + F++ ++ F+++ + ++ ++ ++ F+++ + F++ + F++ + F++ + F++ ++ ++ F+++ + + ++ ++ B + F++ + F++ ++ ++ + F++ B ++ ++ ++ + + + +++ ++ ++ + F++ +++ ++ + F++ ++ F+++ ++ ++
gen (DAKO). For EM, a portion of the renal tissue was immediately fixed with 2.5% glutaraldehyde, followed by postfixation in osmic acid, then dehydrated with graded alcohol and embedded in Epon. Ultrathin sections were double stained with lead citrate and uranyl acetate and examined by EM.
Razzaque/Kumatori/Harada/Taguchi
Immunohistochemistry Conventional streptavidin-biotin staining was used to localize ·smooth muscle actin, CD68, type III collagen and type IV collagen in the selected renal sections using a Histofine SAB kit (Nichirei, Tokyo, Japan). Alkaline phosphatase staining was used to localize HSP47 in the renal sections, using a Histostain-AP kit (Zymed Laboratories, USA). Briefly, paraffin sections (4 Ìm) were dewaxed in xylene, rehydrated in a graded ethanol series, and the endogenous peroxidase activity was blocked with 0.3% hydrogen peroxide in methanol (30 min). For HSP47, incubation in hydrogen peroxide was omitted. After mild treatment with trypsin, the sections were reacted with goat serum to block nonspecific binding of primary antibody (20 min). As immunohistochemical control, monoclonal antibodies were substituted by either 0.01 M phosphate-buffered salins or mouse IgG diluted with phosphate-buffered saline (similar concentration as that of primary antibody). The sections were reacted overnight at 4 ° C with anti-·-smooth muscle actin (Dako, Denmark), anti-CD68 (Dako), anti-type-III collagen (Fuji Chemicals, Japan), anti-type-IV collagen (Dako) or anti-HSP47 (Stress Gen Biotechnologies, Canada) and processed further using the Histofine SAB kit or the Zymed Histostain-AP kit. The staining intensities of ·-smooth muscle actin, type III collagen, type IV collagen and HSP47 were assessed visually and graded semiquantitatively according to the following scale: ++ = high antigenic and/or strong staining intensity, + = definitely lower antigenic and/or weak staining intensity, – = absence of staining. The grade of immunopositivity was determined by dominant antigenic intensity observed in each specimen. CD68-immunopositive macrophage infiltration was denoted by focal and diffuse. Double Immunostaining This was performed to localize HSP47/CD68, HSP47/·-smooth muscle actin, HSP47/type III collagen and HSP47/type IV collagen in the same renal section as described earlier [12, 13]. Briefly, selected paraffin sections (4 Ìm) were deparaffinized, treated with 0.3% hydrogen peroxide in methanol (30 min), reacted with 10% nonimmune goat serum (10 min) and incubated with monoclonal antibody against HSP47 for 1 h. The sections were further treated with biotinylated second antibody (10 min) and streptavidin-alkaline phosphatase (10 min) and developed with BCIP/NBT which produce a dark-purple stain. Then the sections were counterstained with antibodies against either CD68, ·-smooth muscle actin, type III collagen or type IV collagen by the streptavidin-biotin-peroxidase method, and the antigen-antibody complex was visualized using aminoethyl carbazole/H2O2 which produce an intense red stain.
Results Immunohistochemical Localization of Type III and Type IV Collagens Immunostaining for type III collagen (fig. 1a) was found in the interstitium (+), while type IV collagen (fig. 1b) was present in mesangium (+), glomerular basement membrane (+) and tubular basement membrane (TBM; +) of the control glomeruli. Compared to the control cases, increased immunostaining (++) for type III collagen (fig. 1c, e) and type IV collagen (fig. 1d, f) was
HSP47 Expression in Human Renal Diseases
observed in the DN (fig. 1c, d) and IgAN (fig. 1e, f) cases. Although the staining pattern was different, type III collagen was mainly detected in the interstitial fibrosis and focally in the sclerotic glomeruli; type IV collagen was detected mainly in the glomerulosclerotic lesions and thickened TBM. Both type III and type IV collagens were present diffusely in the globally sclerotic glomeruli, but of lesser intensity than in early sclerotic glomeruli. Immunohistochemical Localization of HSP47 HSP47 expression was weakly and occasionally detected in the glomeruli, in the tubular epithelial cells and in the interstitial cells in control kidney (fig. 2a). In contrast to controls, in DN sections markedly increased HSP47 immunostaining was noted in sclerotic glomeruli (fig. 2b, c), tubular epithelial cells and interstitial cells in the region of interstitial fibrosis (fig. 2d). In IgAN, similar to DN sections, increased expression of HSP47 was also noted in mesangial proliferative glomeruli (fig. 3a–c) and fibrotic interstitium (fig. 3d). Increased expression of HSP47 was mainly noted in proliferating glomeruli with expanded mesangial matrix and pericapsular fibrosis in around 75% of the cases. However, the immunostaining for HSP47 was much less intense in the globally sclerotic glomeruli than in early sclerotic glomeruli in both DN and IgAN. In the same renal section, when both sclerotic glomeruli and nonsclerotic glomeruli were present, nonsclerotic glomeruli showed no significant change of immunostaining for HSP47. In addition, compared to the weak
(For fig. 1–3 see next pages.) Fig. 1. Immunohistochemistry for type III collagen (a) and type IV collagen (b) in control renal sections. Immunostaining for type III collagen is noted mainly in the interstitium, while mesangium, glomerular basement membrane and TBM positively stained for type IV collagen in the control kidney. In DN section, strong immunostaining for type III collagen (c) is noted in the nodular lesion of a glomerulus and in interstitial fibrosis. Strong immunostaining for type IV collagen (d) is also present in DN section and is located mainly in sclerotic glomerulus and thickened TBM. In IgAN, almost similar stainings of type III collagen (e) and type IV collagen (f) as for DN sections are noted in the glomeruli. Fig. 2. Immunohistochemistry for HSP47 in a control renal section, showing weak staining for HSP47 in glomerulus and interstitial cells (a). In DN section, markedly increased HSP47 immunostaining is noted in the sclerotic glomeruli (b, c), in the tubular epithelial cells and in the interstitial cells in the region of fibrosis (d). Fig. 3. Immunohistochemical staining of HSP47 in IgAN sections. Increased expression of HSP47 is noted in the mesangial proliferative glomeruli (a–c). Strong expression of HSP47 is also present in the tubular epithelial cells and interstitial cells (d) in the interstitial fibrotic lesions.
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1b
1c
1d
1e
1f
(For fig. legends 1–3 see page 437.)
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3d
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immunostaining for HSP47 in and around the blood vessels in the control sections, relatively increased HSP47 immunopositivity was seen in medial smooth muscle cells and perivascular cells of the thickened blood vessels in both DN and IgAN sections. When monoclonal HSP47 was replaced by a similar concentration of mouse IgG, no specific staining was noted. Details of HSP47 staining intensity in the renal sections of the individual cases are summarized in tables 1 and 2. Colocalization of HSP47 and Collagens To examine whether the increased expression of HSP47 in DN and IgAN is associated with increased accumulation of collagens, double immunostaining for HSP47 and collagens was performed in the same renal section. Increased expression of type III collagen in the region of interstitial fibrosis was accompanied by increased interstitial expression of HSP47 (fig. 4a, b), while co-expression of both HSP47 and type IV collagen was present in the sclerotic glomeruli (fig. 4c, d) in DN sections. A similar colocalization was also noted in IgAN sections (data not shown).
a
b Fig. 6. Double staining of paraffin sections using antibodies against HSP47/CD68 (a) and HSP47/·-smooth muscle actin (b). HSP47 is stained dark-purple, and CD68 or ·-smooth muscle actin is stained intense red. Note that CD68-positive macrophages (arrowheads) are mostly negative for HSP47 expression (a), while ·-smooth muscle actin positive glomerular and interstitial cells are mostly positive for HSP47 expression (b) in DN sections.
Fig. 4. Double staining of paraffin sections using antibodies against HSP47/type III collagen (a, b) and HSP47/type IV collagen (c, d). HSP47 is stained dark-purple and collagens are stained intense red. Note that the immunostaining for HSP47 is associated with increased deposition of collagens in the areas of pericapsular fibrosis (a), interstitial fibrosis (b) and glomerulosclerosis (c, d) in DN sections. Fig. 5. Immunohistochemistry for CD68 in a control renal section, showing scattered CD68-positive cells in glomerulus and tubulointerstitium (a). In a DN section, increased infiltrations of CD68positive macrophages are seen in a sclerotic glomerulus (b). ·Smooth muscle actin is mainly present in the vascular wall in the control kidney (c). In contrast, intraglomerular cells and interstitial cells showing strong immunostaining for ·-smooth muscle actin in the diabetic kidney (d).
HSP47 Expression in Human Renal Diseases
Immunohistochemical Localization of CD68 and ·-Smooth Muscle Actin CD68 was scatteringly present in the control kidneys (fig. 5a), while increased numbers of CD68-positive macrophages were seen in both glomeruli and tubulointerstitium in DN sections (fig. 5b). ·-Smooth muscle actin was present mainly in the vascular wall in the control kidneys (fig. 5c). In diabetic kidneys, intraglomerular cells and interstitial cells showed strong immunostaining for ·smooth muscle actin (fig. 5d). Increased intraglomerular expression of ·-smooth muscle actin and infiltration of CD68 were also noted in IgAN sections (data not shown). Colocalization of HSP47 and CD68 or ·-Smooth Muscle Actin To determine whether the HSP47-expressing cells in the DN and IgAN sections are intrinsic cells or infiltrating macrophages, double immunostaining for HSP47 and CD68 or ·-smooth muscle actin was performed in the same renal section. HSP47-positive cells were mostly negative for CD68 (fig. 6a), while ·-smooth muscle actin positive glomerular and interstitial cells were found to express HSP47 (fig. 6b), suggesting that HSP47-expressing cells are mainly intrinsic renal (both resident and phenotypically altered) cells rather than infiltrating inflammatory cells in both DN and IgAN sections.
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Discussion Collagen is synthesized as prepro alpha chains, and then three prepro alpha chains form procollagen with a triple-helical structure in the endoplasmic reticulum. HSP47 is a collagen-binding stress protein and has been shown to be localized exclusively in the endoplasmic reticulum [8, 11, 14]. Procollagen polypeptides are found to form a complex with HSP47 in the endoplasmic reticulum which plays an important role in the intracellular processing/folding of procollagen molecules as a collagen-specific molecular chaperone [7]. The crucial role of HSP47 in regulating translocation/translation of collagen molecules has been reported elsewhere [14–21]; however, its role in human kidney in relation to sclerosis/fibrosis in DN and IgAN is completely unknown. The major finding of the present study was that HSP47 was strongly expressed in the sclerotic/fibrotic lesions in human DN and IgAN sections, as detected by immunohistochemistry. Also, increased expression of HSP47 in DN and IgAN sections correlated with the increased expression of type III and type IV collagens. In this study, utilizing a double immunohistochemistry technique, we were able to show colocalization of HSP47 and collagens in the sclerotic/fibrotic lesions in human DN and IgAN selections. HSP47 was strongly present in mesangial cells, glomerular epithelial cells, tubular epithelial cells and interstitial cells in both DN and IgAN sections. In addition, expression of HSP47 was also occasionally noted in the expanded extracellular matrix of sclerotic glomeruli and interstitium. In our earlier studies, using nonradioactive in situ hybridization, we have clearly shown that mesangial cells, glomerular epithelial cells, tubular epithelial cells and interstitial cells are rich sources of type III and type IV collagens in human DN and IgAN [4, 5]. It should be noted that while our results showed an association between HSP47 and collagen expression in sclerosis/fibrosis, no direct evidence for a causal relationship could be presented, and an exact nature of the association has yet to be defined. However, as HSP47 plays an important role(s) in the synthesis, processing and assembly of various collagens [11, 14–19], elevated levels of HSP47 in DN and IgAN sections may play a significant role in the subsequent manifestation of glomerulosclerosis and interstitial fibrosis. There are several studies that have examined the expression of HSP47 in experimental models of sclerosis/ fibrosis, and an increased expression of both HSP47 and collagens was always noted in the sclerotic/fibrotic le-
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sions. For example, the HSP47 expression was augmented in CCl4-induced liver cirrhosis, bleomycin-induced pulmonary fibrosis and antithymocyte serum induced glomerulosclerosis in rats in parallel with increased deposition of various collagens [12, 16, 22]. The expression of HSP47 was also markedly elevated in gentamicin nephropathy, hypertensive Dahl rat kidneys, cisplatin-induced tubulointerstitial nephritis and aging Fischer 344 rat kidneys in parallel with increased expression of various collagens [13, 23–25]. From the collagen-synthesizing ability, it is thought that increased levels of HSP47 in human DN and IgAN might have a key regulatory role for sclerotic/fibrotic changes that are found in the advanced stage of the disease. These results demonstrate that despite the differences in the disease patterns, the expression of HSP47 was increased during collagenization in human DN and IgAN, a result which may be of importance also in other human fibrotic diseases in general. In fact, in a separate study, we have shown that the expression of HSP47 is substantially increased in various human fibrotic lung diseases along with an increased deposition of type III collagen [26]. Factor(s) regulating increased synthesis of HSP47 in human DN and IgAN are not clear from this study. When cultured human mesangial cells were incubated with different concentrations of glucose (5–40 ÌM) for various time periods (24–72 h), we could not detect any significant difference in the mRNA expression of HSP47 between control and glucose-treated mesangial cells by Northern blot hybridization (data not shown). From the results, it appears that a hyperglycemic environment might not be the main factor for increased expression of HSP47 in human DN; rather similar patterns of expression of HSP47 in both DN and IgAN might be suggestive of a common inducer of increased levels of HSP47 in both these diseases. Further in vivo and in vitro studies are warranted to examine the factors regulating increased synthesis of HSP47 in human DN and IgAN. In conclusion, increased expression of HSP47 in human DN and IgAN might contribute significantly to the structural alterations, possibly by assembling increased amounts of collagens, resulting in glomerulosclerosis and interstitial fibrosis that are found in advanced stages of both DN and IgAN.
Razzaque/Kumatori/Harada/Taguchi
Acknowledgments Part of this work was supported by a grant-in-aid for scientific research to M.S.R. (Grant No. 09670192) from the Ministry of Education, Science and Culture, Japan. The authors thank Ms. R. Toga-
wa and Ms. Y. Yamashita for preparing the paraffin sections during this study. We are also indebted to Mr. K. Yamamoto and Ms. N. Ohnishi (medical students) for performing most of the immunohistochemical study. Special thanks are also due to Dr. C. Ming, Dr. A. Nazneen, and Ms. Y. Inanaga for their help.
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References 1 Morel-Maroger Striker L, Killen PD, Chi E, Striker GE: The composition of glomerulosclerosis. I. Studies in focal sclerosis, crescentic glomerulonephritis, and membranoproliferative glomerulonephritis. Lab Invest 1984;51:181– 192. 2 Woodrow D, Moss J, Shore I, Spiro RG: Diabetic glomerulosclerosis – Immunogold ultrastructural studies on the glomerular distribution of type IV collagen and heparan sulphate proteoglycan. J Pathol 1992;167:49–58. 3 Oomura A, Nakamura T, Arakawa M, Ooshima A, Isemura M: Alteration of extracellular matrix components in human glomerular diseases. Virchows Arch A Pathol Anat Histopathol 1989;415:151–159. 4 Razzaque MS, Koji T, Taguchi T, Harada T, Nakane PK: In situ localization of type III and type IV collagen expressing cells in human diabetic nephropathy. J Pathol 1994;174:131– 138. 5 Razzaque MS, Taguchi T: Similarities of intraglomerular collagen synthesis in IgA nephropathy and diabetic glomerulosclerosis. Mod Pathol 1994;7:891. 6 Nagata K, Yamada KM: Phosphorylation and transformaiton sensitivity of a major collagenbinding protein of fibroblasts. J Biol Chem 1986;261:7531–7536 7 Nagata K, Saga S, Yamada KM: A major collagen-binding protein of chick embryo fibroblasts is a novel heat shock protein. J Cell Biol 1986;103:223–229. 8 Nakai A, Satoh M, Hirayoshi K, Nagata K: Involvement of the stress protein HSP47 in procollagen processing in the endoplasmic reticulum. J Cell Biol 1992;117:903–914. 9 Cates GA, Nandan D, Brickenden AM, Sanwal BD: Differentiation defective mutants of skeletal myoblasts altered in a gelatin-binding glycoprotein. Biochem Cell Biol 1987;65:767–775.
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10 Cates GA, Brickenden AM, Sanwal BD: Possible involvement of a cell surface glycoprotein in the differentiation of skeletal myoblasts. J Biol Chem 1984;259:2646–2650. 11 Saga S, Nagata K, Chen WT, Yamada KM: pH-dependent function, purification, and intracellular location of a major collagen-binding glycoprotein. J Cell Biol 1987;105:517–527. 12 Razzaque MS, Taguchi T: Collagen-binding heat shock protein (HSP) 47 expression in antithymocyte serum (ATS)-induced glomerulonephritis. J Pathol 1997;183:24–29. 13 Razzaque MS, Shimokawa I, Nazneen A, Higami Y, Taguchi T: Age-related nephropathy in the Fischer 344 rat is associated with overexpression of collagens and collagen-binding heat shock protein 47. Cell Tissue Res 1998;293: 471–478. 14 Miyaishi O, Sakata K, Matsuyama M, Saga S: Distribution of the collagen binding heat-shock protein in chicken tissues. J Histochem Cytochem 1992;40:1021–1029. 15 Sauk JJ, Smith T, Norris K, Ferreira L: Hsp47 and the translation-translocation machinery cooperate in the production of alpha 1(I) chains of type I procollagen. J Biol Chem 1994;269: 3941–3946. 16 Masuda H, Fukumoto M, Hirayoshi K, Nagata K: Coexpression of the collagen-binding stress protein HSP47 gene and the alpha 1(I) and alpha 1(III) collagen genes in carbon tetrachloride-induced rat liver fibrosis. J Clin Invest 1994;94:2481–2488. 17 Shroff B, Smith T, Norris K, Pileggi R, Sauk JJ: Hsp47is localized to regions of type I collagen production in developing murine femurs and molars. Connect Tissue Res 1993;29:273–286.
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18 Kambe K, Yamamoto A, Yoshimori T, Hirayoshi K, Ogawa R, Tashiro Y: Preferential localization of heat shock protein 47 in dilated endoplasmic reticulum of chicken chondrocytes. J Histochem Cytochem 1994;42:833– 841. 19 Ferreira LR, Norris K, Smith T, Hebert C, Sauk JJ: Association of Hsp47, Grp78, and Grp94 with procollagen supports the successive or coupled action of molecular chaperones. J Cell Biochem 1994; 56:518–526. 20 Satoh M, Hirayoshi K, Yokota S, Hosokawa N, Nagata K: Intracellular interaction of collagenspecific stress protein HSP47 with newly synthesized procollagen. J Cell Biol 1996;133: 469–483. 21 Nagata K: Hsp47: A collagen-specific molecular chaperone. Trends Biochem Sci 1996;21: 22–26. 22 Razzaque MS, Hossain MA, Kohno S, Taguchi T: Bleomycin-induced pulmonary fibrosis in rat is associated with increased expression of collagen-binding heat shock protein (HSP) 47. Virchows Arch 1998;432:455–460. 23 Razzaque MS, Cheng M, Horita Y, Taguchi T, Harada T: Expression of collagen binding heat shock protein 47 (HSP 47) in cisplatin-induced tubulointerstitial nephritis in rats (abstract). J Am Soc Nephrol 1996;7:1845. 24 Cheng M, Razzaque MS, Nazneen A, Taguchi T: Expression of the heat shock protein 47 in gentamicin-treated rat kidneys. Int J Exp Pathol 1998;79:125–132. 25 Razzaque MS, Ohnishi N, Yamamoto M, Nazneen A, Taguchi T: Heat shock protein (HSP) 47 in hypertensive Dahl rat kidney (abstract). Jpn J Nephrol 1998;40:134. 26 Razzaque MS, Nazneen A, Taguchi T: Immunolocalization of collagen and collagen-binding heat shock protein 47 in human fibrotic lung diseases. Mod Pathol, in press.
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