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Taneda S, Pippin JW, Sage EH, Hudkins KL, Takeuchi Y, Couser WG, Alpers CE. Amelioration of diabetic nephropathy in SPARC-null mice. J Am Soc Nephrol 2003; 14:968-80. [PMID: 12660331 DOI: 10.1097/01.asn.0000054498.83125.90] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
SPARC (Secreted Protein, Acidic and Rich in Cysteine) is a matricellular protein that inhibits mesangial cell proliferation and also affects production of extracellular matrix (ECM) by regulating transforming growth factor-beta1 (TGF-beta1) and type I collagen in mesangial cells. This study is an investigation of the role of SPARC in streptozotocin (STZ)-induced diabetic nephropathy (DN) of 6-mo duration in wild type (WT) and SPARC-null mice. SPARC expression was evaluated by immunohistochemistry (IHC) and by in situ hybridization (ISH). Deposition of type I and IV collagen and laminin was evaluated by IHC, and TGF-beta 1 mRNA was assessed by ISH. Renal function studies revealed no significant difference in BUN between diabetic SPARC-null mice and diabetic WT mice, whereas a significant increase in albumin excretion was detected in diabetic WT relative to diabetic SPARC-null mice. Diabetic WT animals exhibited increased levels of SPARC mRNA and protein in glomerular epithelial cells and in interstitial cells, in comparison with nondiabetic WT mice. Neither SPARC mRNA nor protein was detected in SPARC-null mice. Morphometry revealed a significant increase in the percentage of the glomerular tufts occupied by ECM in diabetic WT compared with nondiabetic WT mice, although there was no difference in the mean glomerular tuft area among groups. In contrast, diabetic SPARC-null mice did not show a significant difference in the percentage of the glomerular tufts occupied by ECM relative to nondiabetic null mice. Tubulointerstitial fibrosis was ameliorated in diabetic SPARC-null mice compared with diabetic WT animals. Further characterization of diabetic SPARC-null mice revealed diminished glomerular deposition of type IV collagen and laminin, and diminished interstitial deposition of type I and type IV collagen correlated with decreases in TGF-beta 1 mRNA compared with WT diabetic mice. These observations suggest that SPARC contributes to glomerulosclerosis and tubulointerstitial damage in response to hyperglycemia through increasing TGF-beta 1 expression in this model of chronic DN.
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Affiliation(s)
- Sekiko Taneda
- Department of Pathology, Division of Nephrology, University of Washington, Seattle Washington 98195, USA
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Pardo A, Ruiz V, Arreola JL, Ramírez R, Cisneros-Lira J, Gaxiola M, Barrios R, Kala SV, Lieberman MW, Selman M. Bleomycin-induced pulmonary fibrosis is attenuated in gamma-glutamyl transpeptidase-deficient mice. Am J Respir Crit Care Med 2003; 167:925-32. [PMID: 12468440 DOI: 10.1164/rccm.200209-1007oc] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
To investigate repair mechanisms in bleomycin-induced pulmonary fibrosis, we used mice deficient in gamma-glutamyl transpeptidase (GGT-/-), a key enzyme in glutathione (GSH) and cysteine metabolism. Seventy-two hours after bleomycin (0.03 U/g), GGT-/- mice displayed a different inflammatory response to wild-type mice as judged by a near absence of neutrophils in lung tissue and bronchoalveolar lavage and a less pronounced rise in matrix metalloproteinase-9. Inflammation in GGT-/- mice consisted mainly of lymphocytes and macrophages. At 1 month, lungs from bleomycin-treated GGT-/- mice exhibited minimal areas of fibrosis compared with wild-type mice(light microscopy fibrosis index: 510 +/- 756 versus 1975 +/- 817, p < 0.01). Lung collagen content revealed a significant increase in bleomycin-treated wild-type (15.1 +/- 3.8 versus 8.5 +/- 0.7 microg hydroxy(OH)-proline/mg dry weight, p < 0.01) but not in GGT-/- (10.4 +/- 1.7 versus 8.8 +/- 0.8). Control lungs from GGT-/- showed a significant reduction of cysteine (0.03 +/- 0.005 versus 0.055 +/- 0.001, p < 0.02) and GSH levels (1.24 +/- 0.055 versus 1.79 +/- 0.065, p < 0.002). These values decreased after 72 hours of bleomycin in both GGT-/- and wild-type but reached their respective control values after 1 month. Supplementation with N-acetyl cysteine partially ameliorated the effects of GGT deficiency. These findings suggest that increased neutrophils and matrix metalloproteinase-9 during the early inflammatory response and adequate thiol reserves are key elements in the fibrotic response after bleomycin-induced pulmonary injury.
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Affiliation(s)
- Annie Pardo
- Instituto Nacional de Enfermedades Respiratorias, Tlalpan 4502, Col. Sección XVI, México DF, CP 14080, México
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Francki A, Motamed K, McClure TD, Kaya M, Murri C, Blake DJ, Carbon JG, Sage EH. SPARC regulates cell cycle progression in mesangial cells via its inhibition of IGF-dependent signaling. J Cell Biochem 2003; 88:802-11. [PMID: 12577314 DOI: 10.1002/jcb.10424] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Glomerular mesangial cells both synthesize and respond to insulin-like growth factor-1 (IGF-1). Increased activity of the IGF signaling pathway has been implicated as a major contributor to renal enlargement and subsequent development of diabetic nephropathy. Secreted protein acidic and rich in cysteine (SPARC), a matricellular protein, has been shown to modulate the interaction of cells with growth factors and extracellular matrix. We have reported that primary glomerular mesangial cells derived from SPARC-null mice exhibit an accelerated rate of proliferation and produce substantially decreased levels of transforming growth factor beta1 (TGF-beta1) in comparison to their wild-type counterparts (Francki et al. [1999] J. Biol. Chem. 274: 32145-32152). Herein we present evidence that SPARC modulates IGF-dependent signaling in glomerular mesangial cells. SPARC-null mesangial cells produce increased amounts of IGF-1 and -2, as well as IGF-1 receptor (IGF-1R) in comparison to wild-type cells. Addition of recombinant SPARC to SPARC-null cells inhibited IGF-1-stimulated mitogen activated protein kinase (MAPK) activation and DNA synthesis. We also show that the observed accelerated rate of basal and IGF-1-stimulated proliferation in mesangial cells derived from SPARC-null animals is due, at least in part, to markedly diminished levels of cyclin D1 and the cyclin-dependent kinase (cdk) inhibitors p21 and p27. Since expression of SPARC in the glomerulus is especially prominent during renal injury, our findings substantiate previous claims that SPARC is involved in glomerular remodeling and repair, a process commonly associated with mesangioproliferative glomerulonephritis and diabetic nephropathy.
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Affiliation(s)
- Aleksandar Francki
- Department of Vascular Biology, The Hope Heart Institute, Seattle, Washington 98104, USA.
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Alpers CE, Hudkins KL, Segerer S, Sage EH, Pichler R, Couser WG, Johnson RJ, Bassuk JA. Localization of SPARC in developing, mature, and chronically injured human allograft kidneys. Kidney Int 2002; 62:2073-86. [PMID: 12427131 DOI: 10.1046/j.1523-1755.2002.00680.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND The matricellular protein SPARC (secreted protein acidic and rich in cysteine) is expressed during development, tissue remodeling and repair. It functions as an endogenous inhibitor of cell proliferation, regulates angiogenesis, regulates cell adhesion to extracellular matrix, binds cytokines such as platelet derived growth factor and stimulates transforming growth factor-beta (TGF-beta) production. This study describes the expression of SPARC during human renal development, in normal kidneys and during renal allograft rejection. METHODS A total of 60 renal specimens, including normal areas from tumor nephrectomies (N = 24), fetal kidneys (N = 27) and explanted renal allografts (N = 9), were included in the study. SPARC protein was localized by immunohistochemistry using two different antibodies. On consecutive sections SPARC mRNA was detected by in situ hybridization. RESULTS In the normal adult kidney SPARC protein was expressed by visceral and parietal epithelial cells, collecting duct epithelium (CD), urothelium, smooth muscle cells of muscular arteries and focally in interstitial cells. During renal development immature glomeruli demonstrated a polarized SPARC expression in visceral epithelial cells at their surface abutting the capillary basement membranes. In the fully differentiated glomeruli the expression pattern mirrored that of the adult kidney. Furthermore, SPARC was abundantly expressed by derivatives of the ureteric bud, and smooth muscle cells of arterial walls. During chronic allograft rejection SPARC is expressed in neointimal arterial smooth muscle cells, infiltrating inflammatory cells as well as by interstitial myofibroblasts in areas of interstitial fibrosis. SPARC mRNA synthesis detected by in situ hybridization mirrored these protein expression patterns. CONCLUSION These studies co-localize SPARC to several sites of renal injury previously shown to be sites of PDGF B-chain expression and/or activity. We speculate that SPARC could function as an accessory molecule in chronic PDGF-mediated sclerosing interstitial and vascular injury. SPARC localization to glomerular epithelial cells corresponds to similar findings in rodents, and may reflect its role in cell adhesion and /or regulation of cell shape.
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Affiliation(s)
- Charles E Alpers
- Department of Pathology, University of Washington School of Medicine, Seattle Washington, USA.
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55
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Dhanesuan N, Sharp JA, Blick T, Price JT, Thompson EW. Doxycycline-inducible expression of SPARC/Osteonectin/BM40 in MDA-MB-231 human breast cancer cells results in growth inhibition. Breast Cancer Res Treat 2002; 75:73-85. [PMID: 12500936 DOI: 10.1023/a:1016536725958] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
SPARC (secreted protein acidic and rich in cysteine)/BM40/Osteonectin is a matricellular protein with multiple effects on cell behaviour. In vitro, its major known functions are anti-adhesive and anti-proliferative, and it is associated with tissue remodelling and cancer in vivo. SPARC is overexpressed in many cancers, including breast cancer, and the effects of SPARC seem to be cell type-specific. To study the effects of SPARC on breast cancer, we transfected SPARC into the MDA-MB-231 BAG, human breast cancer cell line using the Tet-On inducible system. By western analysis, we found low background levels in the MDA-MB-231 BAG and clone X parental cells, and prominent induction of SPARC protein expression after doxycycline treatment in SPARC transfected clones X5, X21, X24 and X75. Induction of SPARC expression did not affect cell morphology or adhesiveness to collagens type I and IV, but it slowed the rate of proliferation in adherent cultures. Cell cycle analysis showed that SPARC slowed the progression to S phase. Doxycycline induction of SPARC also slowed the rate of monolayer wound closure in the cultured wound healing assay. Thymidine inhibition of proliferation abrogated this effect, confirming that it was due to anti-proliferation rather than inhibition of migration. Consistent with this, we were unable to detect any differences in migration and Matrigel outgrowth analysis of doxycycline-stimulated cells. We conclude that SPARC is inhibitory to human breast cancer cell proliferation, and does not stimulate migration, in contrast to its stimulatory effects reported for melanoma (proliferation and migration) and glioma (migration) cells. Similar growth repression by SPARC has been reported for ovarian cancer cells, and this may be a common feature among carcinomas.
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Affiliation(s)
- Nirada Dhanesuan
- VBCRC Breast Cancer Invasion and Metastasis Unit, St. Vincent's Institute of Medical Research Melbourne, Australia
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Abbate M, Zoja C, Rottoli D, Corna D, Tomasoni S, Remuzzi G. Proximal tubular cells promote fibrogenesis by TGF-beta1-mediated induction of peritubular myofibroblasts. Kidney Int 2002; 61:2066-77. [PMID: 12028447 DOI: 10.1046/j.1523-1755.2002.00380.x] [Citation(s) in RCA: 92] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND In proteinuric nephropathies with increasingly severe defects of the glomerular filtering barrier, interstitial fibrogenesis is a major effector of scarring. An early event in this process is the peritubular accumulation of myofibroblasts that express alpha-smooth muscle actin (alpha-SMA) and contribute to abnormal matrix production. Common trigger factors are poorly understood. Enhanced protein trafficking may play a role by up-regulating inflammatory and fibrogenic genes in proximal tubular cells. METHODS The remnant kidney model in rats was used to (1) analyze interactions between activated proximal tubular cells, peritubular cells expressing the myofibroblast marker, and inflammatory cells at time intervals (days 7, 14, and 30) after surgery, and (2) evaluate the effects of angiotensin-converting enzyme inhibitor (ACEi) on protein trafficking, fibrogenic signaling, and alpha-SMA expression. RESULTS Abnormal uptake of ultrafiltered proteins by proximal tubular cells (IgG staining) occurred at an early stage (day 7) and was subsequently associated with macrophage and alpha-SMA+ cell accumulation into the peritubular interstitium. alpha-SMA+ cells clustered with macrophages into the interstitium. These changes were associated with appearance of transforming growth factor-beta1 (TGF-beta1) mRNA in proximal tubular cells and in the infiltrating cells with time. At day 30, focal alpha-SMA staining also was found in the tubular cells and in peritubular endothelial cells on semithin ultracryosections. ACEi prevented both proteinuria and abnormal protein accumulation in tubular cells, as well as the inflammatory and fibrogenic reaction with peritubular alpha-SMA expression. CONCLUSIONS Profibrogenic signaling from both proximal tubular cells on challenge with filtered protein and inflammatory cells is implicated as a key candidate trigger of progressive tubulointerstitial injury.
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Affiliation(s)
- Mauro Abbate
- Mario Negri Institute for Pharmacological Research, Bergamo, Italy.
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Shimizu A, Yamada K, Sachs DH, Colvin RB. Persistent rejection of peritubular capillaries and tubules is associated with progressive interstitial fibrosis. Kidney Int 2002; 61:1867-79. [PMID: 11967039 DOI: 10.1046/j.1523-1755.2002.00309.x] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND We have reported that a 12-day course of high dose cyclosporine A treatment in thymectomized miniature swine with major histocompatibility complex (MHC) class I-mismatched renal allografts results in transient acute rejection followed by either in chronic rejection (progression group) or graft acceptance (recovery group). Here, we examined the differential features between both groups in the peritubular capillaries (PTCs) and tubules to clarify the pathogenesis of the progressive interstitial fibrosis in chronic rejection. METHODS Morphometric and immunohistochemical studies were performed on serial renal biopsies (days 0 to 100) obtained from both groups, focusing on the cellular infiltrate, rejection of PTCs and tubules, myofibroblast accumulation, and progressive interstitial fibrosis. RESULTS In the progression group, acute rejection occurred by day 8 and progressed to chronic rejection by day 100, with the development of interstitial fibrosis. PTC endothelial cell and tubular epithelial cell death associated with CD3+ cell infiltration was evident, confirmed by nick end-labeling (TUNEL), commencing by day 8 and continuing thereafter. In acute rejection, destruction of PTCs and tubules accompanied by disruption of basement membrane (BM) occurred with capillaritis or tubulitis in areas with a severe cellular infiltrate. During the development of chronic rejection, capillaritis of PTCs and tubulitis continued by day 100, accompanied by persistent T cell infiltration, and the remaining PTCs and tubules exhibited progressive atrophy with thickening and/or lamination of BM. On day 100, identifiable PTCs and tubules were lost in areas of interstitial fibrosis. Proliferating (PCNA+) alpha-actin+ myofibroblasts accumulated around PTCs, tubules and in interstitium, and widespread interstitial fibrosis developed by day 100. In contrast, in the recovery group, injured PTCs and tubules recovered by day 100 based on the resolution of acute rejection, and minimal loss of PTCs and tubules was evident by day 100 with minimal interstitial fibrosis. CONCLUSIONS Persistent rejection directed at PTCs and tubules, and proliferation of myofibroblasts are prominent features in the progressive interstitial fibrosis in chronic rejection, and are probably key events in its pathogenesis.
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Affiliation(s)
- Akira Shimizu
- Department of Pathology and Transplantation Biology Research Center, Massachusetts General Hospital/Harvard Medical School, Boston, Massachusetts 02114, USA
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58
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Kang DH, Kanellis J, Hugo C, Truong L, Anderson S, Kerjaschki D, Schreiner GF, Johnson RJ. Role of the microvascular endothelium in progressive renal disease. J Am Soc Nephrol 2002; 13:806-816. [PMID: 11856789 DOI: 10.1681/asn.v133806] [Citation(s) in RCA: 223] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
The role of the vascular endothelium in progressive renal disease is not well understood. This review presents evidence that progressive renal disease is characterized by a progressive loss of the microvasculature. The loss of the microvasculature correlates directly with the development of glomerular and tubulointerstitial scarring. The mechanism is mediated in part by a reduction in the endothelial proliferative response, and this impairment in capillary repair is mediated by alteration in the local expression of both angiogenic (vascular endothelial growth factor) and antiangiogenic (thrombospondin 1) factors in the kidney. The alteration in balance of angiogenic growth factors is mediated by both macrophage-associated cytokines (interleukin-1beta) and vasoactive mediators. Finally, there is intriguing evidence that stimulation of angiogenesis and/or capillary repair may stabilize renal function and slow progression and that this benefit occurs independently of effects on BP or proteinuria. Therefore, angiogenic agents may represent a novel therapeutic approach for slowing the progression of renal disease.
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Affiliation(s)
- Duk-Hee Kang
- *Baylor College of Medicine, Houston, Texas; University of Nurnberg, Nurnberg, Germany; Division of Nephrology, Oregon Health Sciences University and Portland Veterans Administration Medical Center, Portland, Oregon; Department of Clinical Pathology, University of Vienna, Vienna, Austria; Scios Inc, Sunnyvale, California; and Division of Nephrology, Ewha Women's University College of Medicine, Ewha Medical Research Center, Seoul, Korea
| | - John Kanellis
- *Baylor College of Medicine, Houston, Texas; University of Nurnberg, Nurnberg, Germany; Division of Nephrology, Oregon Health Sciences University and Portland Veterans Administration Medical Center, Portland, Oregon; Department of Clinical Pathology, University of Vienna, Vienna, Austria; Scios Inc, Sunnyvale, California; and Division of Nephrology, Ewha Women's University College of Medicine, Ewha Medical Research Center, Seoul, Korea
| | - Christian Hugo
- *Baylor College of Medicine, Houston, Texas; University of Nurnberg, Nurnberg, Germany; Division of Nephrology, Oregon Health Sciences University and Portland Veterans Administration Medical Center, Portland, Oregon; Department of Clinical Pathology, University of Vienna, Vienna, Austria; Scios Inc, Sunnyvale, California; and Division of Nephrology, Ewha Women's University College of Medicine, Ewha Medical Research Center, Seoul, Korea
| | - Luan Truong
- *Baylor College of Medicine, Houston, Texas; University of Nurnberg, Nurnberg, Germany; Division of Nephrology, Oregon Health Sciences University and Portland Veterans Administration Medical Center, Portland, Oregon; Department of Clinical Pathology, University of Vienna, Vienna, Austria; Scios Inc, Sunnyvale, California; and Division of Nephrology, Ewha Women's University College of Medicine, Ewha Medical Research Center, Seoul, Korea
| | - Sharon Anderson
- *Baylor College of Medicine, Houston, Texas; University of Nurnberg, Nurnberg, Germany; Division of Nephrology, Oregon Health Sciences University and Portland Veterans Administration Medical Center, Portland, Oregon; Department of Clinical Pathology, University of Vienna, Vienna, Austria; Scios Inc, Sunnyvale, California; and Division of Nephrology, Ewha Women's University College of Medicine, Ewha Medical Research Center, Seoul, Korea
| | - Dontscho Kerjaschki
- *Baylor College of Medicine, Houston, Texas; University of Nurnberg, Nurnberg, Germany; Division of Nephrology, Oregon Health Sciences University and Portland Veterans Administration Medical Center, Portland, Oregon; Department of Clinical Pathology, University of Vienna, Vienna, Austria; Scios Inc, Sunnyvale, California; and Division of Nephrology, Ewha Women's University College of Medicine, Ewha Medical Research Center, Seoul, Korea
| | - George F Schreiner
- *Baylor College of Medicine, Houston, Texas; University of Nurnberg, Nurnberg, Germany; Division of Nephrology, Oregon Health Sciences University and Portland Veterans Administration Medical Center, Portland, Oregon; Department of Clinical Pathology, University of Vienna, Vienna, Austria; Scios Inc, Sunnyvale, California; and Division of Nephrology, Ewha Women's University College of Medicine, Ewha Medical Research Center, Seoul, Korea
| | - Richard J Johnson
- *Baylor College of Medicine, Houston, Texas; University of Nurnberg, Nurnberg, Germany; Division of Nephrology, Oregon Health Sciences University and Portland Veterans Administration Medical Center, Portland, Oregon; Department of Clinical Pathology, University of Vienna, Vienna, Austria; Scios Inc, Sunnyvale, California; and Division of Nephrology, Ewha Women's University College of Medicine, Ewha Medical Research Center, Seoul, Korea
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McParland PC, Bell SC, Pringle JH, Taylor DJ. Regional and cellular localization of osteonectin/SPARC expression in connective tissue and cytotrophoblastic layers of human fetal membranes at term. Mol Hum Reprod 2001; 7:463-74. [PMID: 11331670 DOI: 10.1093/molehr/7.5.463] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Fetal membranes overlying the cervix in patients prior to and during labour, and within the rupture tear after spontaneous delivery at term, exhibit altered morphology. In this study we report that in comparison to mid-zone fetal membranes biopsies, these regions are characterized by increased expression of the matricellular protein osteonectin or SPARC (Secreted Protein Acidic and Rich in Cysteine). In the reticular layer, the percentage of vimentin positive mesenchymal cells immunoreactive for osteonectin increased in these regions from 3-4% to 25-33% and represented a fraction of the alpha-smooth muscle actin positive myofibroblasts elevated in the same regions. In the fibroblastic layer, the percentage of osteonectin positive cells increased from 1-5% to 8-13%; however, these did not exhibit the same relationship to the alpha-smooth muscle actin positive myofibroblasts in this layer. In the cytotrophoblastic layer the percentage of cytotrophoblastic cells immunoreactive for osteonectin increased from 1% to 6-12%. Elevation of in-situ detectable mRNA was also observed in the same cellular populations in this region. The incidence of cells positive for osteonectin mRNA or protein in the reticular layer correlated with morphological changes. Osteonectin has been implicated in the regulation of extracellular matrix turnover, and its pattern of expression suggests a role in the regional connective tissue and cytotrophoblastic changes proposed to be involved in the cleavage and rupture of fetal membranes.
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Affiliation(s)
- P C McParland
- Preterm Birth Research Group, Department of Obstetrics, Leicester Warwick Medical School, Faculty of Medicine and Biological Sciences, University of Leicester, Leicester LE2 7LX, UK
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Gilbert RE, Cox AJ, Kelly DJ, Wilkinson-Berka JL, Sage EH, Jerums G, Cooper ME. Localization of secreted protein acidic and rich in cysteine (SPARC) expression in the rat eye. Connect Tissue Res 2000; 40:295-303. [PMID: 10757117 DOI: 10.3109/03008209909000707] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Secreted protein acidic and rich in cysteine (SPARC) is a secreted glycoprotein protein which modulates cell shape and cell-matrix interactions and has been implicated in the regulation of angiogenesis, vascular permeability and cataract formation. In situ hybridization and immunohistochemical studies for SPARC were performed to determine the cell and tissue distribution of SPARC in rat eye. Studies demonstrated SPARC mRNA and protein co-localization at all sites. In the retina SPARC mRNA and protein were localized predominantly to the Müller and ganglion cells. Within the choroid, SPARC was found in vascular endothelial cells and fibroblasts; in the sclera SPARC was present in blood vessels and fibroblasts. SPARC was also present in the non-pigmented epithelial cells of the ciliary body, and in the epithelium of the lens capsule and cornea. The demonstrated anatomical distribution of SPARC in the rat eye is consistent with several of the biological functions ascribed to this matricellular protein and provides a rational basis for its examination in pathological conditions.
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Affiliation(s)
- R E Gilbert
- Department of Medicine, Austin and Repatriation Medical Centre, West Heidelberg, Victoria, Australia.
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Abe K, Ozono Y, Miyazaki M, Koji T, Shioshita K, Furusu A, Tsukasaki S, Matsuya F, Hosokawa N, Harada T, Taguchi T, Nagata K, Kohno S. Interstitial expression of heat shock protein 47 and alpha-smooth muscle actin in renal allograft failure. Nephrol Dial Transplant 2000; 15:529-35. [PMID: 10727549 DOI: 10.1093/ndt/15.4.529] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Tubulointerstitial inflammation and fibrosis are the main pathological features of chronic renal allograft rejection, which is characterized by accumulation of extracellular matrix protein. Heat shock protein 47 (HSP47), known as a collagen-specific stress protein, is thought to be a molecular chaperone during the processing and/or secretion of procollagen. HSP47 is thought to be involved in the progression of fibrosis, but its expression in chronic renal allograft rejection is still unknown. METHODS We examined the expression of HSP47 together with that of alpha-smooth muscle actin (alpha-SMA), a marker of myofibroblasts, and CD68, a marker of macrophages, by immunohistochemistry in allograft kidney tissues. Uninvolved portions of surgically removed kidneys with tumours served as control tissue. RESULTS Expression of HSP47 was detected in the interstitium of fibrotic regions of allograft kidneys. Cells positive for HSP47 were also stained for alpha-SMA and type I collagen, and the expression of HSP47 correlated with the degree of interstitial fibrosis. Furthermore, the expression of HSP47 correlated with the number of infiltrating macrophages. In contrast, HSP47 and alpha-SMA were not expressed in the control tissues, sections of 1 h post-transplantation biopsy specimens and acute allograft rejection without fibrosis. CONCLUSION Our results suggest that HSP47 may contribute to the progression of interstitial fibrosis in allograft renal tissues.
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Affiliation(s)
- K Abe
- Second Department of Internal Medicine, Department of Histology and Cell Biology, Nagasaki University School of Medicine, Sakamoto, Nagasaki
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Walpen S, Beck KF, Eberhardt W, Apel M, Chatterjee PK, Wray GMH, Thiemermann C, Pfeilschifter J. Downregulation of SPARC expression is mediated by nitric oxide in rat mesangial cells and during endotoxemia in the rat. J Am Soc Nephrol 2000; 11:468-476. [PMID: 10703670 DOI: 10.1681/asn.v113468] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Nitric oxide (NO) has been implicated in several forms of glomerulonephritis. In this study, a low stringency reversed transcription/PCR protocol was used to evaluate the action of NO on the mRNA expression pattern in rat mesangial cells (MC). To mimic the state of glomerular inflammation, MC were stimulated by exposure to the cytokines interleukin-1beta and tumor necrosis factor-alpha into producing high levels of NO via expression of inducible nitric oxide synthase (NOS). To detect NO-mediated effects, the resulting expression pattern was compared to that of MC stimulated by the cytokines in the presence of the NOS inhibitor N(G)-monomethyl-L-arginine (L-NMMA). Computer analysis of a differentially expressed cDNA fragment resulted in a 100% homology to the recently characterized mRNA of SPARC (secreted protein acidic and rich in cysteine). Further characterization of SPARC regulation revealed a cytokine- and cAMP-dependent decrease in SPARC mRNA and protein levels. Blocking NO formation by L-NMMA reversed the effects of cytokines and cAMP on SPARC expression, suggesting an NO-mediated mechanism. The NO donors S-nitroso-N-acetyl-penicillamine and diethylenetriamine/NO further reduced SPARC expression in cytokine-treated MC as well as in controls. Moreover, downregulation of SPARC mRNA and protein expression in whole kidneys obtained from rats treated with endotoxin was observed. This downregulation of SPARC was reversed by treatment with L-N6-l (iminoethyl) lysine dihydrochloride, a potent and highly selective inhibitor of inducible NOS. These data characterize SPARC as an NO-regulated gene. This observation may be important in the context of tissue remodeling in chronic inflammatory kidney diseases.
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Affiliation(s)
- Sebastian Walpen
- Zentrum der Pharmakologie, Klinikum der Johann Wolfgang Goethe-Universität, Frankfurt am Main, Germany
| | - Karl-Friedrich Beck
- Zentrum der Pharmakologie, Klinikum der Johann Wolfgang Goethe-Universität, Frankfurt am Main, Germany
| | - Wolfgang Eberhardt
- Zentrum der Pharmakologie, Klinikum der Johann Wolfgang Goethe-Universität, Frankfurt am Main, Germany
| | - Martina Apel
- Zentrum der Pharmakologie, Klinikum der Johann Wolfgang Goethe-Universität, Frankfurt am Main, Germany
| | - Prabal K Chatterjee
- The William Harvey Research Institute, St. Bartholomew's and The Royal London School of Medicine and Dentistry, London, United Kingdom
| | - Gillian M H Wray
- The William Harvey Research Institute, St. Bartholomew's and The Royal London School of Medicine and Dentistry, London, United Kingdom
| | - Christoph Thiemermann
- The William Harvey Research Institute, St. Bartholomew's and The Royal London School of Medicine and Dentistry, London, United Kingdom
| | - Josef Pfeilschifter
- Zentrum der Pharmakologie, Klinikum der Johann Wolfgang Goethe-Universität, Frankfurt am Main, Germany
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Bassuk JA, Pichler R, Rothmier JD, Pippen J, Gordon K, Meek RL, Bradshaw AD, Lombardi D, Strandjord TP, Reed M, Sage EH, Couser WG, Johnson R. Induction of TGF-beta1 by the matricellular protein SPARC in a rat model of glomerulonephritis. Kidney Int 2000; 57:117-28. [PMID: 10620193 DOI: 10.1046/j.1523-1755.2000.00811.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
UNLABELLED Induction of TGF-beta1 by the matricellular protein SPARC in a rat model of glomerulonephritis. BACKGROUND SPARC has been implicated as a counteradhesive and antiproliferative protein associated with deposits of extracellular matrix in renal disease. METHOD We have examined the effect of recombinant SPARC containing a C-terminal His tag (rSPARC) in an acute model of mesangial cell injury that is induced in the rat by an antibody against the Thy1 antigen on the mesangial cell membrane. The recombinant protein was administered 24 hours after the induction of nephritis and was infused through day 4. RESULTS rSPARC was localized to the renal glomeruli of rats treated with anti-Thy1 antibody. Type I collagen and fibronectin, as well as transforming growth factor-beta1 (TGF-beta1), were increased at day 5 in rats treated with rSPARC (N = 4, P < 0.05 vs. delivery buffer), but only minimal effects were seen on mesangial cell and endothelial cell proliferation. In primary cultures of rat mesangial cells, infusion of rSPARC was associated with increases in TGF-beta1 mRNA and in total, secreted TGF-beta1 protein. CONCLUSIONS rSPARC stimulates expression of TGF-beta1 both in vitro and in vivo. Given the closely regulated expression of SPARC, TGF-beta1, and type I collagen in several animal models of glomerulonephritis, we propose that SPARC could be one of the major mediators of the induction of TGF-beta1 in renal disease.
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Affiliation(s)
- J A Bassuk
- Department of Biological Structure, University of Washington School of Medicine, Seattle, Washington 98195-7420, USA.
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Jandeleit-Dahm K, Rumble J, Cox AJ, Kelly DJ, Dziadek M, Cooper ME, Gilbert RE. SPARC gene expression is increased in diabetes-related mesenteric vascular hypertrophy. Microvasc Res 2000; 59:61-71. [PMID: 10625572 DOI: 10.1006/mvre.1999.2189] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The anti-adhesive extracellular matrix protein SPARC (secreted protein and rich in cysteine; osteonectin or BM-40) has been implicated in the regulation of matrix turnover, cell migration, and proliferation. The present study sought to examine whether modulation in the expression of this protein may play a role in diabetes-associated vascular remodeling. SPARC mRNA and protein were measured in mesenteric vessels of diabetic rats and controls. Hypertrophy of mesenteric vessels was noted after 3 and 32 weeks of diabetes as revealed by the increase in mesenteric vessel wet weight and an increased wall/lumen ratio. SPARC mRNA was sparsely present in intima and adventitia of control vessels. There was a marked increase in SPARC gene expression in the intima and adventitia of mesenteric vessels after 1, 3, and 32 weeks of diabetes. SPARC protein was demonstrated in the vessel wall in control animals and was increased in the mesenteric vessels of diabetic rats after 1 and 32 weeks of diabetes. Administration of the inhibitor of advanced glycation end-product formation, aminoguanidine, to diabetic rats attenuated both the hypertrophic response in mesenteric vessels and the overexpression of SPARC mRNA and protein without affecting glycemic control or food intake. In summary, diabetes-related mesenteric vascular hypertrophy is associated with an increase in SPARC expression in the vessel wall. The modulation of SPARC expression in mesenteric vessels of diabetic rats might be of pathogenetic significance in the development of vascular remodeling in diabetes.
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Affiliation(s)
- K Jandeleit-Dahm
- Department of Medicine, University of Melbourne, West Heidelberg, Victoria, Australia
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65
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Abstract
The development of a reproducible animal model that mimics CSA nephropathy in man has allowed the examination of the several proposed mechanisms of toxicity. While the precise mechanism remains to be defined, important clues have been provided and creative techniques for minimizing the adverse effects of this very valuable adjunct to transplant success have been identified.
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Affiliation(s)
- G A Porter
- Division of Nephrology, Hypertension and Clinical Pharmacology, Oregon Health Sciences University, Portland 97201, USA.
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66
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Wardle EN. Modulatory proteins and processes in alliance with immune cells, mediators, and extracellular proteins in renal interstitial fibrosis. Ren Fail 1999; 21:121-33. [PMID: 10088173 DOI: 10.3109/08860229909066977] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
A synopsis of the many aspects and factors that contribute to renal tubulo-interstitial fibrosis is presented. The role of fibrogenic cytokines and the conversion of fibroblasts to myofibroblasts are described. It is emphasized that oxygen radicals cause fibroblasts to generate collagen. The properties of those accessory modulatory proteins that affect the behavior of cells in the interstitium are considered and how matrix for ensuing fibrosis is laid down. Understanding the extracellular matrix proteins and these modulatory proteins is important because their behavior can now be modified by means of antisense oligonucleotides.
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67
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Johnson RJ, Hugo C, Haseley L, Pichler R, Bassuk J, Thomas S, Suga S, Couser WG, Shankland SJ. Mechanisms of progressive glomerulosclerosis and tubulointerstitial fibrosis. Clin Exp Nephrol 1998. [DOI: 10.1007/bf02480459] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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68
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Abstract
Follistatin was first described in 1987 as a follicle-stimulating hormone inhibiting substance present in ovarian follicular fluid. We now know that this effect of follistatin is only one of its many properties in a number of reproductive and nonreproductive systems. A majority of these functions are facilitated through the affinity of follistatin for activin, where activin's effects are neutralized through its binding to follistatin. As such, the interplay between follistatin and activin represents a powerful regulatory mechanism that impinges on a variety of cellular processes within the body. In this review we focus on the biochemical characteristics of follistatin and its interaction with activin and discuss the emerging role of these proteins as potent tissue regulators in the gonad, pituitary gland, pregnancy membranes, vasculature, and liver. Consideration is also given to the larger family of proteins that contain follistatin-like modules, in particular with regard to their functional and structural implications.
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Affiliation(s)
- D J Phillips
- Institute of Reproduction and Development, Monash University, Clayton, Victoria, 3168, Australia.
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69
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Abstract
BACKGROUND The remnant kidney model has been widely used to identify mechanisms responsible for the progression of renal disease. However, the structural changes associated with progressive loss of function in this model have not been well characterized. METHODS Kidney function and structure were assessed at 10 weeks (REM 10) and 25 weeks (REM 25) after five-sixths renal ablation and in control rats (Control). Serial sections were examined to relate glomerular and tubular structure in individual nephrons. RESULTS Remnant kidney function declined between 10 and 25 weeks after ablation (GFR 0.90 +/- 0.34 vs. 0.23 +/- 0.07 ml/min, REM 10 vs. REM 25, P < 0.05). This decline in function was associated with an increase in the prevalence of globally sclerotic glomeruli (14 +/- 10 vs. 0 +/- 0 vs. 0 +/- 0%, REM 25 vs. REM 10 vs. Control, P < 0.05 REM 25 vs. REM 10 and Control). The decline in remnant kidney function between 10 and 25 weeks was also associated with the appearance of glomeruli that were atubular (48 +/- 14 vs. 9 +/- 8 vs. 3 +/- 5%, REM 25 vs. REM 10 vs. Control, P < 0.05 REM 25 vs. REM 10 and Control) or connected to atrophic proximal tubule segments (26 +/- 10 vs. 11 +/- 6 vs. 1 +/- 2%, REM 25 vs. REM 10 vs. Control, P < 0.05 all comparisons). Atubular glomeruli, which usually had open capillary loops available for filtration, were more numerous than globally sclerotic glomeruli at 25 weeks after ablation. CONCLUSIONS These findings indicate that tubular injury contributes to progressive loss of renal function following reduction in nephron number.
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Affiliation(s)
- M Gandhi
- Division of Nephrology, VA Palo Alto Health Care System and Stanford University, California 94304, USA.
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70
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Abstract
Vascular nephropathies are a steadily increasing cause of end-stage renal failure. Arterionephrosclerosis and arteriolonephrosclerosis are common features in the hypertensive patient. This is especially true for blacks of African descent, in whom hypertension and nephrovasculopathies are a major cause of renal insufficiency. That primary hypertension leads to renal vascular lesions, glomerular obsolescence and interstitial fibrosis has long been established. It should not, however, obscure the fact that renal vascular lesions can be observed in animal models as well as in some humans, especially young blacks, in the absence of, or anticipating the onset of hypertension. This leads to considering the hypothesis that nephroangiosclerosis might stem from a genetic defect in the renal vascular bed and that this defect is strongly associated with the hypertensive trait. Atherosclerotic renal disease is a major, potentially treatable cause of chronic renal disease is a major, potentially treatable cause of chronic renal failure, especially in whites. It leads to renal atrophy, but the ischemic kidney retains a vigorous potential for tubular cell regeneration, which pleads for early recognition and treatment. Recent data suggest that renal ischemia, be it due to renal artery stenosis or to cholesterol crystal embolism, ranks among the multiple causes of secondary focal segmental glomerulosclerosis. Irrespective of its initial mechanism, ischemia induces renal fibrosis, the pathophysiology of which is centered on increased generation of angiotensin II. Finally, renal vascular lesions are commonly observed in the course of various nephropathies, even in the absence of hypertension, and the relationship between these lesions and the unfavorable prognosis of glomerulopathies, especially primary focal-segmental glomerulosclerosis, membranous glomerulopathy and IgA glomerulonephritis, remains to be elucidated. Expanding knowledge of the spectrum of nephrovasculopathies opens perspectives for investigating, understanding and treating a major mechanism of progressive renal insufficiency.
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Affiliation(s)
- A Meyrier
- Service de Néphrologie, Hôpital Broussais, Paris, France
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71
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Abstract
Cyclosporine has improved patient and graft survival rates in solid organ transplantation, and has been increasingly applied with considerable clinical benefit in the treatment of autoimmune diseases. However, the therapeutic benefits of immunosuppressive therapy for transplant and autoimmune indications have frequently been limited by the occurrence of chronic nephrotoxicity. Cyclosporine nephrotoxicity therefore remains an important clinical challenge. The clinical aspects and pathophysiology of chronic cyclosporine nephrotoxicity, which is characterized by a decrease in glomerular filtration rate, afferent arteriolopathy, and striped tubulointerstitial fibrosis, are reviewed. Insights gained from experimental models of chronic nephrotoxicity associated with tubulointerstitial fibrosis are presented to elucidate the pathophysiology.
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Affiliation(s)
- T F Andoh
- Department of Medicine, Oregon Health Sciences University, Portland, USA.
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Kanauchi M, Nishioka H, Kawano T, Dohi K. Role of secreted protein acidic and rich in cysteine (SPARC) in patients with diabetic nephropathy. Clin Exp Nephrol 1997. [DOI: 10.1007/bf02479910] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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