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Luo L, Sun Z, Wu W, Luo G. Mycophenolate mofetil and FK506 have different effects on kidney allograft fibrosis in rats that underwent chronic allograft nephropathy. BMC Nephrol 2012; 13:53. [PMID: 22747784 PMCID: PMC3470947 DOI: 10.1186/1471-2369-13-53] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2012] [Accepted: 06/21/2012] [Indexed: 01/05/2023] Open
Abstract
Background Tacrolimus (FK506) is associated with renal fibrosis in long-term use. Mycophenolatemofetil (MMF) can also inhibit or attenuate the progression of renal fibrosis. This study aimed to determine the different effects of FK506 and MMF on fibrosis-associated genes in the kidney in rats that underwent chronic allograft nephropathy (CAN). Methods Fisher (F344) kidneys were orthotopically transplanted into Lewis rat recipients. All recipients were given Cyclosporin A (CsA) 10 mg/kg-1.d-1 × 10 day and were then randomly divided into three oral treatment groups (n = 9 in each group): (1) the vehicle group was given vehicle orally; (2) the FK506 group was given 0.15 mg/kg-1.d-1 FK506; and (3) the MMF group was given 20 mg/kg-1.d-1 MMF. At 4, 8, and 12 weeks post-transplantation, serum creatinine (SCr), collagen deposition, Connective tissue growth factor (CTGF), alpha smooth muscle actin (α-SMA) and E-cadherin expressions were determined and hematoxylin-eosin (HE) and Periodic acid-Schiff (PAS) stains were performed. Results Renal function progressively deteriorated and showed typical CAN morphology in the vehicle and FK506 groups, while SCr and inflammatory infiltration (Banff score) showed a significant decrease in the MMF group after 8 weeks post-transplantation compared with those in the other groups (p < 0.05). Furthermore, expression levels of CTGF and α-SMA in the MMF group were significantly reduced, and the down-regulated expression of E-cadherin was abated (p < 0.05). Conclusions MMF showed favorable effects on renal interstitial fibrosis, thus efficiently retarding the progression of CAN.
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Affiliation(s)
- Lei Luo
- Department of Research and Education, Guizhou Province People's Hospital, Guiyang, China
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Zheng M, Lv LL, Cao YH, Zhang JD, Wu M, Ma KL, Phillips AO, Liu BC. Urinary mRNA markers of epithelial-mesenchymal transition correlate with progression of diabetic nephropathy. Clin Endocrinol (Oxf) 2012; 76:657-64. [PMID: 21824169 DOI: 10.1111/j.1365-2265.2011.04192.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
OBJECTIVE Epithelial-mesenchymal transition (EMT) plays an important role in the pathogenesis and progression of diabetic nephropathy (DN). Quantification of messenger RNA (mRNA) expression in urinary sediment is emerging as a noninvasive method of screening DN-associated biomarkers. The aim of our study was to examine whether urinary mRNA profile of EMT-associated genes may provide valuable clinical insight into the different stages of DN. DESIGN AND METHODS Diabetic nephropathy patients (n = 44) and healthy controls (n = 12) were enrolled in this study. DN patients were divided into three groups according to the levels of estimated glomerular filtration rate (eGFR): Group A (eGFR > 60 ml/min per 1·73 m(2), n = 27), Group B (45 < eGFR < 60 ml/min per 1·73 m(2), n = 9), and Group C (eGFR < 45 ml/min per 1·73 m(2), n = 8). Relative mRNA abundance of α-smooth muscle actin (α-SMA), fibronectin, FSP1 and matrix metalloproteinase-9 (MMP-9) were quantified, and correlations between target mRNAs and clinical parameters were examined. RESULTS The urinary mRNA levels of α-SMA, fibronectin and MMP-9 were significantly higher in the DN group compared with controls (P < 0·05), and mRNA levels increased with DN progression. Urinary mRNA levels of all target genes positively correlated with both urinary albumin excretion (UAE) and blood urea nitrogen (BUN). Moreover, the expression of α-SMA, fibronectin and MMP-9 mRNA correlated with serum creatinine levels (r = 0·514, r = 0·53 and r = 0·469, all P < 0·001) and GFR levels (r = -0·374, r = -0·392 and r = -0·487, all P < 0·01). CONCLUSIONS Quantification of EMT-associated genes in urinary sediment may be a novel approach for searching new biomarkers of DN.
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Affiliation(s)
- Min Zheng
- Institute of Nephrology, Zhong Da Hospital, Southeast University School of Medicine, Nanjing, China
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Celie JW, Katta KK, Adepu S, Melenhorst WB, Reijmers RM, Slot EM, Beelen RH, Spaargaren M, Ploeg RJ, Navis G, Homan van der Heide JJ, van Dijk MC, van Goor H, van den Born J. Tubular epithelial syndecan-1 maintains renal function in murine ischemia/reperfusion and human transplantation. Kidney Int 2012; 81:651-61. [DOI: 10.1038/ki.2011.425] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Luo L, Sun Z, Luo G. Rapamycin is less fibrogenic than Cyclosporin A as demonstrated in a rat model of chronic allograft nephropathy. J Surg Res 2012; 179:e255-63. [PMID: 22480837 DOI: 10.1016/j.jss.2012.02.059] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2011] [Revised: 02/14/2012] [Accepted: 02/28/2012] [Indexed: 11/27/2022]
Abstract
BACKGROUND Cyclosporin A (CsA) is associated with significant chronic nephrotoxicity, which typically manifests as renal fibrosis. In contrast, rapamycin (RAPA) has been shown to inhibit fibrosis. This study sought to determine the effect of CsA and RAPA on the expression of connective tissue growth factor (CTGF) and E-cadherin in a rat kidney model of chronic allograft nephropathy. MATERIALS AND METHODS Left renal grafts from male Fisher (F344, RT1(1v1)) rats were orthotopically transplanted into Lewis (LEW, RT1(1)) rats. After transplantation, all recipients were given CsA 10 mg/kg(-1) d(-1) for 10 d and divided into three groups (n = 9/group): (1) vehicle, administered orally; (2) CsA, 6 mg/kg(-1) d(-1); (3) RAPA, 0.8 mg/kg(-1) d(-1). At 4, 8, and 12 wk posttransplantation, the kidney allografts were harvested and serum creatinine levels were measured. Connective tissue growth factor expression was determined using real-time polymerase chain reaction and Western blot. Kidney allografts sections also underwent hematoxylin-eosin and Masson trichrome staining, in addition to CTGF and E-cadherin immunostaining. RESULTS The serum creatinine levels were increased at 8 and 12 wk posttransplantation and were significantly lower in the RAPA group (P < 0.05). The Banff score also showed a significant decrease at 4, 8, and 12 wk (P < 0.05). CTGF messenger ribonucleic acid and protein levels were significantly lower in the RAPA group (P < 0.05), whereas E-cadherin expression was higher in the RAPA group at 4, 8, and 12 wk (P < 0.05). Masson's trichrome staining showed a significant decrease in collagen deposition at 8 and 12 wk after RAPA treatment. CONCLUSION RAPA can ameliorate fibrogenesis in kidney allografts by inhibiting epithelial-mesenchymal transition process, whereas CsA did not have this effect.
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Affiliation(s)
- Lei Luo
- Department of Research and Education, Guizhou Province People's Hospital, Guiyang, China
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55
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Epithelial phenotypic changes detect cyclosporine in vivo nephrotoxicity at a reversible stage. Transplantation 2011; 92:993-8. [PMID: 21909056 DOI: 10.1097/tp.0b013e31822fa495] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
BACKGROUND A widely used immunosuppressant, cyclosporine A (CsA), conveys long-term nephrotoxicity in some patients. However, no specific marker is presently available. In both native and transplanted human kidneys, epithelial phenotypic changes (EPCs) suggestive of epithelial to mesenchymal transition (EMT) are expressed in various diseases and are prognostic with respect to progression of interstitial fibrosis. We hypothesized that CsA is able to trigger these EPCs in tubular cells in vivo. METHODS We studied the kinetics of the EMT markers β-catenin, snail, vimentin, collagen III, and HSP47 at the messenger RNA and protein levels in the kidneys from rats injected with 15 mg/kg/day of CsA or its vehicle. We investigated several therapeutic strategies available to block EMT in this model. RESULTS By 2 weeks, CsA had induced histological changes (tubular dilatation and vacuoles) and overexpression of EMT-related genes. This up-regulation of the EMT program was associated with tubular, not interstitial, overexpression of mesenchymal markers. Angiotensin II and endothelin receptor antagonists failed to prevent this CsA-induced EMT. Interestingly, CsA withdrawal led to the gradual regression of histological lesions and EMT, demonstrating that it not only prevents progression but also allows healing of renal injury. CONCLUSION Our study suggests that detecting EPC could help to identify ongoing renal CsA-induced toxicity at an early and reversible stage.
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The Dual Role of Epithelial-to-Mesenchymal Transition in Chronic Allograft Injury in Pediatric Renal Transplantation. Transplantation 2011; 92:787-95. [DOI: 10.1097/tp.0b013e31822d092c] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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The role of EMT in renal fibrosis. Cell Tissue Res 2011; 347:103-16. [PMID: 21845400 DOI: 10.1007/s00441-011-1227-1] [Citation(s) in RCA: 229] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2011] [Accepted: 07/22/2011] [Indexed: 02/03/2023]
Abstract
It is clear that the well-described phenomenon of epithelial-mesenchymal transition (EMT) plays a pivotal role in embryonic development, wound healing, tissue regeneration, organ fibrosis and cancer progression. EMTs have been classified into three subtypes based on the functional consequences and biomarker context in which they are encountered. This review will highlight findings on type II EMT as a direct contributor to the kidney myofibroblast population in the development of renal fibrosis, specifically in diabetic nephropathy, the signalling molecules and the pathways involved in type II EMT and changes in the expression of specific miRNA with the EMT process. These findings have provided new insights into the activation and development of EMT during disease processes and may lead to possible therapeutic interventions to suppress EMTs and potentially reverse organ fibrosis.
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Huang B, Pi L, Chen C, Yuan F, Zhou Q, Teng J, Jiang T. WT1 and Pax2 re-expression is required for epithelial-mesenchymal transition in 5/6 nephrectomized rats and cultured kidney tubular epithelial cells. Cells Tissues Organs 2011; 195:296-312. [PMID: 21778682 DOI: 10.1159/000327530] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/09/2011] [Indexed: 11/19/2022] Open
Abstract
Mature tubular epithelial cells in the adult kidney can undergo epithelial-mesenchymal transition (EMT), a phenotypic change that is linked to the pathogenesis of renal interstitial fibrosis. EMT may be considered the reverse of mesenchymal-epithelial transition, which occurs during normal kidney development. The Wilms' tumor suppressor gene WT1 and the paired box 2 gene Pax2 are needed to induce mesenchymal-epithelial transition and play key roles in the progression of nephrogenesis. However, until now, WT1 and Pax2 have not been tested for their direct involvement in the process of renal tubular EMT. In this study, we explored the potential roles of WT1 and Pax2 in EMT that is induced in the remnant kidney of rats following 5/6 nephrectomy. We also examined WT1 and Pax2 in cultured renal tubular epithelial (NRK52E) cells treated with interleukin-1α and investigated the effects of blocking EMT using RNA interference. We showed that WT1 and Pax2 were re-expressed in the EMT models, and these were accompanied by decreased expression of E-cadherin and increased expression of vimentin, Snail and α-smooth muscle actin. Silencing WT1 and Pax2 by RNA interference blocked the interleukin-1α-induced EMT in the NRK52E cells, as reflected in the suppression of α-SMA and Snail expression, the restoration of E-cadherin expression and normal cell morphology. Our experiments suggested that the re-expression of WT1 and Pax2 in the tubular epithelial cells plays important roles in the promotion of EMT, and there may be therapeutic value in silencing Pax2 and WT1 to prevent or reverse renal fibrosis.
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Affiliation(s)
- Bin Huang
- Department of Laboratory Medicine, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
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Liu Q, Liu S, Shi Y, Li H, Hao J, Xing L, Cao Y, Duan H. Suppressors of cytokine signaling inhibit tubular epithelial cell-myofibroblast transdifferentiation. Am J Nephrol 2011; 34:142-51. [PMID: 21734367 DOI: 10.1159/000329325] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2011] [Accepted: 05/10/2011] [Indexed: 01/03/2023]
Abstract
BACKGROUND/AIMS Tubular epithelial cell-myofibroblast transdifferentiation (TEMT) can be induced by diverse cytokines. The suppressors of cytokine signaling (SOCS) proteins negatively regulate cytokine signaling. This study is aimed at examining the role of SOCS-1 and SOCS-3 in TEMT induced by cytokines. METHODS The cell ultrastructure was observed using transmission electron microscopy. The protein and mRNA levels of cytokeratin 18 (CK18) and α-smooth muscle actin (α-SMA) were detected by immunocytochemistry, Western blot and real-time PCR. The levels of phosphorylated-signal transducer and activator of transcription (p-STAT) 1 and 3 were detected by Western blot. The protein and mRNA levels of SOCS-1 and SOCS-3 were detected by Western blot and real-time PCR. The levels of collagen type I and fibronectin (FN) were determined by ELISA. RESULTS Interleukin-1β (IL-1β) and oncostatin M (OSM) were able to downregulate CK18 expression and upregulate α-SMA, p-STAT1, p-STAT3, collagen type I and FN expression in cultured human renal proximal tubular epithelial cells (HKCs), whereas pretreatment with AG490 prevented these expression changes from occurring. All of the changes induced by IL-1β or OSM could be decreased by SOCS-1 and SOCS-3 overexpression, and were increased by SOCS-1 and SOCS-3 knockdown. CONCLUSIONS SOCS-1 and SOCS-3 can prevent tubulointerstitial fibrosis by inhibiting TEMT, which may be connected with the activation of STAT1 and STAT3.
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Affiliation(s)
- Qingjuan Liu
- Department of Pathology, Hebei Medical University, Shijiazhuang, China
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60
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Robert R, Ghazali DA, Favreau F, Mauco G, Hauet T, Goujon JM. Gender difference and sex hormone production in rodent renal ischemia reperfusion injury and repair. JOURNAL OF INFLAMMATION-LONDON 2011; 8:14. [PMID: 21658244 PMCID: PMC3127739 DOI: 10.1186/1476-9255-8-14] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/05/2010] [Accepted: 06/09/2011] [Indexed: 01/29/2023]
Abstract
BACKGROUND Several lines of evidence suggest a protective effect of female sex hormones in several organs subjected to ischemia-reperfusion injury. The aim of the study was to investigate sex hormone production in male rats after a renal ischemia-reperfusion sequence and analyze the influence of gender differences on tissue remodelling during the recovery process. METHOD Age-matched sexually mature male and female rats were subjected to 60 min of renal unilateral ischemia by pedicle clamping with contralateral nephrectomy and followed for 1 or 5 days after reperfusion. Plasma creatinine, systemic testosterone, progesterone and estradiol levels were determined. Tubular injury, cell proliferation and inflammation, were evaluated as well as proliferating cell nuclear antigen, vimentin and translocator protein (TSPO) expressions by immunohistochemistry. RESULTS After 1 and 5 days of reperfusion, plasma creatinine was significantly higher in males than in females, supporting the high mortality in this group. After reperfusion, plasma testosterone levels decreased whereas estradiol significantly increased in male rats. Alterations of renal function, associated with tubular injury and inflammation persisted during the 5 days post-ischemia-reperfusion, and a significant improvement was observed in females at 5 days of reperfusion. Proliferating cell nuclear antigen and vimentin expression were upregulated in kidneys from males and attenuated in females, in parallel to injury development. TSPO expression was transiently increased in proximal tubules in male rats. CONCLUSIONS After ischemia, renal function recovery and tissue injury is gender-dependent. These differences are associated with a modulation of sex hormone production and a modification of tissue remodeling and proliferative cell processes.
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Affiliation(s)
- René Robert
- CHU Poitiers, Service de Réanimation Médicale Poitiers, F-86000, France.
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Hills CE, Squires PE. The role of TGF-β and epithelial-to mesenchymal transition in diabetic nephropathy. Cytokine Growth Factor Rev 2011; 22:131-9. [PMID: 21757394 DOI: 10.1016/j.cytogfr.2011.06.002] [Citation(s) in RCA: 117] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Transforming Growth Factor-beta (TGF-β) is a pro-sclerotic cytokine widely associated with the development of fibrosis in diabetic nephropathy. Central to the underlying pathology of tubulointerstitial fibrosis is epithelial-to-mesenchymal transition (EMT), or the trans-differentiation of tubular epithelial cells into myofibroblasts. This process is accompanied by a number of key morphological and phenotypic changes culminating in detachment of cells from the tubular basement membrane and migration into the interstitium. Ultimately these cells reside as activated myofibroblasts and further exacerbate the state of fibrosis. A large body of evidence supports a role for TGF-β and downstream Smad signalling in the development and progression of renal fibrosis. Here we discuss a role for TGF-β as the principle effector in the development of renal fibrosis in diabetic nephropathy, focusing on the role of the TGF-β1 isoform and its downstream signalling intermediates, the Smad proteins. Specifically we review evidence for TGF-β1 induced EMT in both the proximal and distal regions of the nephron and describe potential therapeutic strategies that may target TGF-β1 activity.
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Affiliation(s)
- Claire E Hills
- School of Life Sciences, University of Warwick, Coventry, CV4 7AL, UK.
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Impact of acute rejection on kidney allograft outcomes in recipients on rapid steroid withdrawal. J Transplant 2011; 2011:583981. [PMID: 21647349 PMCID: PMC3103882 DOI: 10.1155/2011/583981] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2011] [Revised: 03/10/2011] [Accepted: 03/19/2011] [Indexed: 12/30/2022] Open
Abstract
Background. Our aim was to study the impact of clinical acute rejection (CR) and subclinical rejection (SR) on outcomes in kidney transplant recipients treated with rapid steroid withdrawal (RSW).
Methods. All patients who received a living or deceased donor kidney transplant and were treated with RSW were included. The primary outcome was death-censored graft survival. Biopsies with Banff borderline changes were included with the rejection groups.
Results. 457 kidney transplant recipients treated with RSW were included; 46 (10%) experienced SR, and 36 (7.8%) had CR. Mean HLA mismatch was significantly higher in the CR group. The Banff grade of rejection was higher in the CR group. There was a larger proportion of patients in both rejection groups with the combination of IFTA and persistent inflammation on the follow-up protocol biopsy done at 1 year. The estimated 5-year death-censored graft survival was 81% in SR, 78% in CR, and 97% in the control group (P < .0001). Significant differences were observed in allograft survival between the CR and control group (HR 9.06, 95% CI 3.39–24.2) and between the SR and control group (HR 4.22, 95% CI 1.30–13.7).
Conclusion. Both SR and CR are associated with an inferior graft survival in recipients on RSW.
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Galichon P, Hertig A. Epithelial to mesenchymal transition as a biomarker in renal fibrosis: are we ready for the bedside? FIBROGENESIS & TISSUE REPAIR 2011; 4:11. [PMID: 21470408 PMCID: PMC3079627 DOI: 10.1186/1755-1536-4-11] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/25/2010] [Accepted: 04/06/2011] [Indexed: 02/08/2023]
Abstract
Over the past two decades, the concept of the epithelial to mesenchymal transition (EMT) has been imported from embryology and oncology to fibrosis, particularly in the kidney. This interest in EMT in the context of renal fibrosis stems from observations of epithelial cells undergoing phenotypic changes reminiscent of fibroblasts. Whether EMT is actually a source of interstitial fibroblasts has been the subject of heated debate, and this controversy has caused physicians to neglect the value of EMT as a biomarker in renal fibrosis. In this review, we describe the evolution of the techniques used to detect EMT during fibrosing renal diseases, and what information they provide in the diagnosis of various renal diseases. Highlighting the great heterogeneity of these techniques and the need to standardize them, we warn against some misleading uses of EMT markers. We suggest using the association of vimentin and β-catenin for the diagnosis of EMT in renal pathology because it is both sensitive and prognostic, thus satisfying the properties required for a screening test. Finally, we discuss the potential interests to diagnose EMT for the comprehension of renal fibrosis and for clinical practice.
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Affiliation(s)
- Pierre Galichon
- Institut national de la santé et de la recherche médicale (INSERM), UMR S702, 4 rue de la Chine, Paris, 75020, France.
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Improving Long-Term Outcome in Allograft Transplantation: Role of Ionic Composition and Polyethylene Glycol. Transplantation 2011; 91:605-14. [DOI: 10.1097/tp.0b013e3182090fa3] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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Quaggin SE, Kapus A. Scar wars: mapping the fate of epithelial-mesenchymal-myofibroblast transition. Kidney Int 2011; 80:41-50. [PMID: 21430641 DOI: 10.1038/ki.2011.77] [Citation(s) in RCA: 152] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The hypothesis that epithelial-mesenchymal transition (EMT) might be a contributor to the accumulation of fibroblasts and myofibroblasts (MFs) in the kidney during fibrogenesis was postulated 15 years ago. This paradigm offered an elegant explanation of how the loss of epithelial functions is coupled to the gain of deleterious mesenchymal functions; for example, excessive matrix deposition. Moreover, it interpreted chronic kidney disease in a developmental context: because the tubular epithelium originates from the metanephric mesenchyme, EMT can be viewed as a dedifferentiation process in response to injury, which might serve healing or--if dysregulated--might facilitate fibrosis. Several observations support the role of EMT in renal fibrosis: (1) Tubular cells can transform to fibroblasts and MFs in vitro. (2) Histological 'snapshots' reveal the coexistence of epithelial and mesenchymal markers in transitioning tubular cells in fibrosis models and human kidney diseases. (3) Early lineage-tracing experiments detected mesenchymal markers in the genetically tagged epithelium. However, the paradigm has been recently challenged; new fate-mapping studies found no evidence for the expression of (myo)fibroblast markers in the epithelium during fibrogenesis. This review summarizes the key findings and caveats, aiming at a balanced view, which neither overestimates the role of the epithelium in MF generation nor denies the importance of epithelial plasticity in fibrogenesis.
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Affiliation(s)
- Susan E Quaggin
- Division of Nephrology, St Michael's Hospital, Samuel Lunenfeld Research Institute, Mount Sinai Hospital, University of Toronto, Toronto, Ontario, Canada
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Boonla C, Krieglstein K, Bovornpadungkitti S, Strutz F, Spittau B, Predanon C, Tosukhowong P. Fibrosis and evidence for epithelial-mesenchymal transition in the kidneys of patients with staghorn calculi. BJU Int 2011; 108:1336-45. [PMID: 21410631 DOI: 10.1111/j.1464-410x.2010.10074.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
OBJECTIVES • To quantify fibrotic lesions in renal tissues obtained from patients with large calculi and to evaluate association with renal function. • Presence of epithelial-mesenchymal transition (EMT) in stone-containing renal tissues was investigated. PATIENTS, SUBJECTS AND METHODS • In all, 50 patients with nephrolithiasis with large calculi and matched healthy controls (37) were recruited. • Plasma creatinine (Cr) and corrected Cr clearance (CCr) were determined in all subjects. • Of the 50 patients, 38 had renal tissue available for histological analysis. Fibrosis was assessed by Masson's trichrome staining. Co-expression of epithelial cytokeratins and mesenchymal markers [α-smooth muscle actin (αSMA) and vimentin] in renal tubular cells was detected by dual immunofluorescence staining. • Expression of fibronectin, transforming growth factor β₁ (TGF-β₁) and CD68 were investigated. RESULTS • Overall, the kidney function of the patients was significantly reduced, indicated by increased plasma Cr and decreased corrected CCr compared with healthy controls. • Inflammation grading in renal tissues of the patients was correlated with the percentage of the fibrotic area. Renal fibrosis was inversely correlated with renal function. • Cytokeratins co-expressed with αSMA and vimentin were found in nephrolithiatic renal tubular cells, and these cells strongly expressed fibronectin and TGF-β₁. • Infiltration of CD68-positive cells was a common finding in the inflamed renal sections. CONCLUSIONS • Kidneys of large stone-forming patients had robust signs of inflammation and fibrosis, and there was a close correlation of renal fibrosis with renal dysfunction. • This is the first study to show evidence for renal tubular cells showing signs of EMT in large stone-containing kidneys. Plausibly, TGF-β₁ triggers EMT, which at least in part contributes to large stone-induced renal fibrosis.
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Affiliation(s)
- Chanchai Boonla
- Department of Biochemistry, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
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Hertig A, Flier SN, Kalluri R. Contribution of epithelial plasticity to renal transplantation-associated fibrosis. Transplant Proc 2011; 42:S7-12. [PMID: 21095454 DOI: 10.1016/j.transproceed.2010.07.040] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Every year in the United States, 5000 renal transplant recipients start or restart dialysis because of the unusual propensity of these allografts to develop interstitial fibrosis and tubular atrophy (IF/TA). Although IF/TA often follows one or more identifiable events, our capacity to specifically treat, prevent, or even detect IF/TA at an early stage is poor. These limitations are largely related to our lack of adequate tools to assess graft failure over time. Data accumulated over the past 5 years have demonstrated that tubular epithelial cells may react to certain fibrogenic stimuli to engage in the process of epithelial-to-mesenchymal transition (EMT). In this review, we highlight the current view of EMT with a focus on both its role in the context of renal transplantation and the potential for utilizing markers of EMT to identify patients undergoing early IF/TA.
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Affiliation(s)
- A Hertig
- Division of Matrix Biology, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA
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Timsit MO, Yuan X, Floerchinger B, Ge X, Tullius SG. Consequences of transplant quality on chronic allograft nephropathy. Kidney Int 2011:S54-8. [PMID: 21116319 DOI: 10.1038/ki.2010.424] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Using kidneys from expanded-criteria donors to alleviate organ shortage has raised concern on reduced transplant outcomes. In this paper, we review how critical donor-related factors such as donor age, brain death, and consequences of ischemia-reperfusion injury (IRI) determine graft quality and impact chronic allograft nephropathy. We propose that combinatorial effects of organ-intrinsic features associated with increasing age and unspecific injuries related to brain death and IRI will impact innate and adaptive immune responses. Future research will need to explore avenues to optimize donor management, organ preservation, adapted immunosuppressive strategies, as well as modifications of the allocation of suboptimal allografts.
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Affiliation(s)
- Marc-Olivier Timsit
- Division of Transplant Surgery and Transplant Surgery Research Laboratory, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA
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Analysis of biliary epithelial-mesenchymal transition in portal tract fibrogenesis in biliary atresia. Dig Dis Sci 2011; 56:731-40. [PMID: 20725787 DOI: 10.1007/s10620-010-1347-6] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/23/2010] [Accepted: 07/12/2010] [Indexed: 12/11/2022]
Abstract
BACKGROUND The cellular origin of myofibroblast in the liver fibrosis remains unclear. This study was designed to investigate whether biliary epithelial cells (BECs) undergoing epithelial-mesenchymal transition (EMT) might be found in patients with biliary atresia, thereby serving as a source of fibrotic myofibroblasts. METHODS Liver sections from patients with biliary atresia were evaluated to detect antigen for the BECs marker 4 and cytokeratin-7 (CK-7), proteins (fibroblast-specific protein 1, also known S100A4; the collagen chaperone heat shock protein 47, HSP47) characteristically expressed by cells undergoing EMT, as well as myofibroblasts marker a-smooth muscle actin (a-SMA). RESULTS Normal bile ducts BECs could express CK-7 and low levels of a-SMA; they did not express S100A4 and HSP47. However, BECs from biliary atresia resulted in increased expression of a-SMA, S100A4, with concurrent transition to a fibroblast-like morphology and decreased expression of AK-7. Furthermore, BECs in biliary atresia were associated with significant bile ductular proliferation and coexpressed both epithelial and mesenchymal markers. CONCLUSIONS From significant histologic evidence, the BECs forming small- and medium-sized bile ducts undergoing EMT may account for prominent bile ductular proliferation and directly contribute to fibrogenesis in BA.
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Vaziri N, Thuillier R, Favreau FD, Eugene M, Milin S, Chatauret NP, Hauet T, Barrou B. Analysis of machine perfusion benefits in kidney grafts: a preclinical study. J Transl Med 2011; 9:15. [PMID: 21266040 PMCID: PMC3038164 DOI: 10.1186/1479-5876-9-15] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2010] [Accepted: 01/25/2011] [Indexed: 12/22/2022] Open
Abstract
Background Machine perfusion (MP) has potential benefits for marginal organs such as from deceased from cardiac death donors (DCD). However, there is still no consensus on MP benefits. We aimed to determine machine perfusion benefits on kidney grafts. Methods We evaluated kidney grafts preserved in ViaspanUW or KPS solutions either by CS or MP, in a DCD pig model (60 min warm ischemia + 24 h hypothermic preservation). Endpoints were: function recovery, quality of function during follow up (3 month), inflammation, fibrosis, animal survival. Results ViaspanUW-CS animals did not recover function, while in other groups early follow up showed similar values for kidney function. Alanine peptidase and β-NAG activities in the urine were higher in CS than in MP groups. Oxydative stress was lower in KPS-MP animals. Histology was improved by MP over CS. Survival was 0% in ViaspanUW-CS and 60% in other groups. Chronic inflammation, epithelial-to-mesenchymal transition and fibrosis were lowest in KPS-MP, followed by KPS-CS and ViaspanUW-MP. Conclusions With ViaspanUW, effects of MP are obvious as only MP kidney recovered function and allowed survival. With KPS, the benefits of MP over CS are not directly obvious in the early follow up period and only histological analysis, urinary tubular enzymes and red/ox status was discriminating. Chronic follow-up was more conclusive, with a clear superiority of MP over CS, independently of the solution used. KPS was proven superior to ViaspanUW in each preservation method in terms of function and outcome. In our pre-clinical animal model of DCD transplantation, MP offers critical benefits.
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Marek I, Volkert G, Jahn A, Fahlbusch F, Zürn C, Ozcan Z, Goppelt-Struebe M, Hilgers KF, Rascher W, Hartner A. Lack of α8 integrin leads to morphological changes in renal mesangial cells, but not in vascular smooth muscle cells. BMC Cell Biol 2010; 11:102. [PMID: 21194485 PMCID: PMC3022721 DOI: 10.1186/1471-2121-11-102] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2010] [Accepted: 12/31/2010] [Indexed: 11/21/2022] Open
Abstract
Background Extracellular matrix receptors of the integrin family are known to regulate cell adhesion, shape and functions. The α8 integrin chain is expressed in glomerular mesangial cells and in vascular smooth muscle cells. Mice deficient for α8 integrin have structural alterations in glomeruli but not in renal arteries. For this reason we hypothesized that mesangial cells and vascular smooth muscle cells differ in their respective capacity to compensate for the lack of α8 integrin. Results Wild type and α8 integrin-deficient mesangial cells varied markedly in cell morphology and expression or localization of cytoskeletal molecules. In α8 integrin-deficient mesangial cells α-smooth muscle actin and CTGF were downregulated. In contrast, there were no comparable differences between α8 integrin-deficient and wild type vascular smooth muscle cells. Expression patterns of integrins were altered in α8 integrin-deficient mesangial cells compared to wild type mesangial cells, displaying a prominent overexpression of α2 and α6 integrins, while expression patterns of the these integrins were not different between wild type and α8 integrin-deficient vascular smooth muscle cells, respectively. Cell proliferation was augmented in α8 integrin-deficient mesangial cells, but not in vascular smooth muscle cells, compared to wild type cells. Conclusions Our findings suggest that α8 integrin deficiency has differential effects in mesangial cells and vascular smooth muscle cells. While the phenotype of vascular smooth muscle cells lacking α8 integrin is not altered, mesangial cells lacking α8 integrin differ considerably from wild type mesangial cells which might be a consequence of compensatory changes in the expression patterns of other integrins. This could result in glomerular changes in α8 integrin-deficient mice, while the vasculature is not affected in these mice.
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Affiliation(s)
- Ines Marek
- Hospital for Children and Adolescents, Universität Erlangen-Nürnberg, Loschgestrasse 15, 91054 Erlangen, Germany
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Chun KW, Park JH, Jung JC, Kim DJ, Park SG, Kim JS, Nam ES, Hyun SJ, Lee S. Expression of E-cadherin, Heat Shock Protein 47, Transforming Growth Factor β1 and C4d in Chronic Allograft Nephropathy. KOREAN JOURNAL OF TRANSPLANTATION 2010. [DOI: 10.4285/jkstn.2010.24.4.298] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Affiliation(s)
- Ki Won Chun
- Department of Surgery, Kang-dong Sacred Heart Hospital, Hallym University College of Medicine, Seoul, Korea
| | - Jun Ho Park
- Department of Surgery, Kang-dong Sacred Heart Hospital, Hallym University College of Medicine, Seoul, Korea
| | - Jin Cheol Jung
- Department of Surgery, Kang-dong Sacred Heart Hospital, Hallym University College of Medicine, Seoul, Korea
| | - Doo Jin Kim
- Department of Surgery, Kang-dong Sacred Heart Hospital, Hallym University College of Medicine, Seoul, Korea
| | - Sung Gil Park
- Department of Surgery, Kang-dong Sacred Heart Hospital, Hallym University College of Medicine, Seoul, Korea
| | - Joo Seop Kim
- Department of Surgery, Kang-dong Sacred Heart Hospital, Hallym University College of Medicine, Seoul, Korea
| | - Eun Suk Nam
- Department of Pathology, Kang-dong Sacred Heart Hospital, Hallym University College of Medicine, Seoul, Korea
| | - Suk Ja Hyun
- Department of Transplantation Center, Kang-dong Sacred Heart Hospital, Hallym University College of Medicine, Seoul, Korea
| | - Samuel Lee
- Department of Surgery, Kang-dong Sacred Heart Hospital, Hallym University College of Medicine, Seoul, Korea
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Kobayashi A, Takahashi T, Horita S, Yamamoto I, Yamamoto H, Teraoka S, Tanabe K, Hosoya T, Yamaguchi Y. Activation of the transcription factor c-Jun in acute cellular and antibody-mediated rejection after kidney transplantation. Hum Pathol 2010; 41:1682-93. [DOI: 10.1016/j.humpath.2010.04.016] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/10/2010] [Revised: 04/13/2010] [Accepted: 04/30/2010] [Indexed: 11/29/2022]
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Carvalho de Matos A, Saraiva Câmara N, Tonato E, de Souza Durão Júnior M, Franco M, Ribeiro Moura L, Pacheco-Silva A. Vimentin Expression and Myofibroblast Infiltration Are Early Markers of Renal Dysfunction in Kidney Transplantation: An Early Stage of Chronic Allograft Dysfunction? Transplant Proc 2010; 42:3482-8. [DOI: 10.1016/j.transproceed.2010.06.014] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2010] [Accepted: 06/08/2010] [Indexed: 01/01/2023]
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Urinary connective tissue growth factor is a biomarker in a rat model of chronic nephropathy. Transplant Proc 2010; 42:1875-80. [PMID: 20620541 DOI: 10.1016/j.transproceed.2009.11.041] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2008] [Accepted: 11/23/2009] [Indexed: 02/05/2023]
Abstract
AIM This study sought to determine whether urinary connective tissue growth factor (CTGF) was a molecular marker for chronic allograft nephropathy (CAN). METHODS F344 rat renal grafts orthotopically transplanted into Lewis rats following the procedure of Kamada were harvested at 4,8,12, or 16 weeks. Morphological changes were studied using hematoxylin eosin (HE) and Masson trichrome stains. Serum creatinine (SCr) was measured. CAN grades were evaluated according to the Banff97 schema. Expressions of CTGF in the kidney and urine were determined using real-time polymerase chain reaction (PCR) Western blots, and competitive indirect enzyme-linked immunosorbent assay (ELISA). Spearman correlation analysis was used to compare urinary CTGF expression and CAN development. RESULTS SCr levels and Banff scores increased in a time-dependent manner. The expression of CTGF in the graft was markedly elevated compared with the control group. Urine CTGF increased by week 4, and maintained high levels up to week 16. The urinary levels correlated positively with the histological presence of CAN. Thus, urine CTGF concentrations reflected the course of CAN, especially at an early stage. CONCLUSION CTGF plays a significant role in the pathological changes of CAN after kidney transplantation. Urinary CTGF has the potential to be a biomarker for CAN.
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Thrombin inhibition during kidney ischemia-reperfusion reduces chronic graft inflammation and tubular atrophy. Transplantation 2010; 90:612-21. [PMID: 20865816 DOI: 10.1097/tp.0b013e3181d72117] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND Ischemia-reperfusion injury (IRI) is an unavoidable component of transplantation and correlates with delayed graft function, acute rejection, chronic fibrosis, and graft loss. Currently, new donor pools are considered to alleviate pressure on waiting lists, such as deceased after cardiac death donors (DCD) and extended criteria donors. Because these organs are particularly sensitive to IRI, there is a need for novel preservation paradigms. We assessed the effect of anticoagulation therapy during graft preservation on IRI and graft outcome. METHODS In a large white autotransplanted pig model, kidneys underwent warm ischemia for 60 min, mimicking DCD, then were preserved for 24 hr at 4°C, in University of Wisconsin solution. Animals were followed up 3 months, functional, histologic, and molecular parameters were assessed. In treated groups, antithrombin was added to collection and preservation protocols. RESULTS Treatment improved chronic graft function, reduced tubular atrophy, and substantially increased animal survival. Quantitative polymerase chain reaction analysis determined that markers of inflammation, such as interferon-[gamma], tumor necrosis factor-[alpha], interleukin (IL)-2, -1Rn, and -10, were significantly reduced in treated grafts. Histologic analysis revealed a lowering of CD3+ invasion. P selectin and C3 mRNA expressions were reduced in treated groups, indicative of lowered complement production and endothelial cell activation. Vascular endothelium growth factor protein expression was up-regulated, suggesting vascular network remodeling. CONCLUSION Inhibition of thrombin during preservation of DCD graft preserved renal integrity and function, protecting against chronic inflammation and tissue damage. Thus, coagulation seems to be a critical target for the development of therapeutic strategies to improve kidney quality for transplantation.
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Intragraft tubular vimentin and CD44 expression correlate with long-term renal allograft function and interstitial fibrosis and tubular atrophy. Transplantation 2010; 90:502-9. [PMID: 20588206 DOI: 10.1097/tp.0b013e3181e86b42] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND Development of interstitial fibrosis and tubular atrophy (IF/TA) is the main histologic feature involved in renal allograft deterioration. The aim of this study was to validate whether de novo tubular expression of CD44 (transmembrane glycoprotein) and vimentin (mesenchymal cell marker), both involved in renal fibrosis, can operate as surrogate markers for late IF/TA and renal function. Furthermore, we wanted to establish the interrater reproducibility for the scoring system, which can be a problem in histologic assessments. METHODS Six-month protocol renal allograft biopsies (n=30 for matching 12 months estimated glomerular filtration rate (eGFR) from which 20 matched the 12-month protocol biopsy) were immunostained for CD44 and vimentin, semiquantitatively scored by three observers of two centers, and correlated with IF/TA and eGFR at 12 months. RESULTS The interobserver agreement was excellent for CD44 (Kendall's W-coefficient: 0.69; P<0.001) and vimentin (Kendall's W-coefficient: 0.79; P<0.001). CD44 and vimentin expression at 6 months were significantly correlated with IF/TA (rho=0.481 for CD44 and rho=0.619 for vimentin) and eGFR (rho=-0.569 for CD44 and rho=-0.376 for vimentin) at 12 months. CONCLUSIONS Summarizing, de novo tubular expression of CD44 and vimentin can function as surrogate marker for IF/TA and eGFR at 12 months. Further area under receiver operator characteristic curve analysis has to establish the predictive value for both biomarkers.
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Gomez-Alamillo C, Benito-Hernandez A, Ramos-Barron M, Agüeros C, Rodrigo E, Ruiz J, Sanchez M, San Cosme L, Arias M. Analysis of Urinary Gene Expression of Epithelial-Mesenchymal Transition Markers in Kidney Transplant Recipients. Transplant Proc 2010; 42:2886-8. [DOI: 10.1016/j.transproceed.2010.07.051] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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Abstract
The pathologic paradigm for renal progression is advancing tubulointerstitial fibrosis. Whereas mechanisms underlying fibrogenesis have grown in scope and understanding in recent decades, effective human treatment to directly halt or even reverse fibrosis remains elusive. Here, we examine key features mediating the molecular and cellular basis of tubulointerstitial fibrosis and highlight new insights that may lead to novel therapies. How to prevent chronic kidney disease from progressing to renal failure awaits even deeper biochemical understanding.
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Affiliation(s)
- Michael Zeisberg
- Division of Matrix Biology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA.
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Cunningham MF, Docherty NG, Burke JP, O'Connell PR. S100A4 expression is increased in stricture fibroblasts from patients with fibrostenosing Crohn's disease and promotes intestinal fibroblast migration. Am J Physiol Gastrointest Liver Physiol 2010; 299:G457-66. [PMID: 20489045 DOI: 10.1152/ajpgi.00351.2009] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Fibroblasts represent the key cell type in fibrostenosing Crohn's disease (FCD) pathogenesis. S100A4 is an EF-hand calcium-binding protein family member, implicated in epithelial-mesenchymal transition and as a marker of activated T lymphocytes and fibroblasts in chronic tissue remodeling. The aim of this study was to examine the expression profile of S100A4 in the resected ileum of patients with FCD. Mucosa, seromuscular explants, and transmural biopsies were harvested from diseased and proximal, macroscopically normal margins of ileocecal resections from patients with FCD. Samples were processed for histochemistry, immunohistochemistry, real-time RT-PCR, Western blotting, and transmission electron microscopy. Primary explant cultures of seromuscular fibroblasts were exposed to transforming growth factor (TGF)-beta1 (1 ng/ml), and S100A4 expression and scratch wound-healing activity were assessed at 24 h. CCD-18Co fibroblasts were transfected with S100A4 small interfering RNA, treated with TGF-beta1 (1 ng/ml) for 30 min or 24 h, and then assessed for S100A4 and Smad3 expression and scratch wound-healing activity. S100A4 expression was increased in stricture mucosa, in the lamina propria, and in CD3-positive intraepithelial CD3-positive T lymphocytes. Fibroblastic S100A4 staining was observed in seromuscular scar tissue. Stricture fibroblast explant culture showed significant upregulation of S100A4 expression. TGF-beta1 increased S100A4 expression in cultured ileal fibroblasts. In CCD-18Co fibroblasts, S100A4 small interfering RNA inhibited scratch wound healing and modestly inhibited Smad3 activation. S100A4 expression is increased in fibroblasts, as well as immune cells, in Crohn's disease stricture and induced by TGF-beta1. Results from knockdown experiments indicate a potential role for S100A4 in mediating intestinal fibroblast migration.
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82
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Cornaire E, Dubois-Xu YC, Rondeau E, Hertig A. [Interstitial fibrosis in renal grafts: On the way to a better detection]. Nephrol Ther 2010; 6:494-8. [PMID: 20627838 DOI: 10.1016/j.nephro.2010.03.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2009] [Revised: 03/22/2010] [Accepted: 03/22/2010] [Indexed: 11/26/2022]
Abstract
In renal grafts, the progression of interstitial fibrosis and tubular atrophy (IF/TA) is exponential during the first months post-transplant. Consequently, roughly 40% of the cadaveric grafts will function less than ten years. There is, however, no specific strategy to halt fibrogenesis, i.e. the progression of fibrosis with time, in kidney recipients. Epithelial to mesenchymal transition (EMT) is a biological process used to disperse cells during embryogenesis. In the setting of injury, it is also a mechanism to escape cellular death. The last five years, several studies demonstrated that EMT does occur in tubular epithelial cells, which have been shown to loose the expression of epithelial markers, and acquire the expression of mesenchymal proteins, like vimentin. The aim of this review is triple: 1) discuss the connections between EMT and the context of transplantation; 2) explain how EMT markers may be useful in clinical practice, as promising surrogate markers for fibrogenesis; 3) discuss some therapeutic perspectives.
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83
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Zhao L, Yang R, Cheng L, Wang M, Jiang Y, Wang S. Epithelial-mesenchymal transitions of bile duct epithelial cells in primary hepatolithiasis. J Korean Med Sci 2010; 25:1066-70. [PMID: 20592900 PMCID: PMC2890885 DOI: 10.3346/jkms.2010.25.7.1066] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/12/2009] [Accepted: 01/07/2010] [Indexed: 01/11/2023] Open
Abstract
The purpose of this study was to explore the role of epithelial-mesenchymal transition in the pathogenesis of hepatolithiasis. Thirty-one patients with primary hepatolithiasis were enrolled in this study. Expressions of E-cadherin, alpha-catenin, alpha-SMA, vimentin, S100A4, TGF-beta1 and P-smad2/3 in hepatolithiasis bile duct epithelial cells were examined by immunohistochemistry staining. The results showed that the expressions of the epithelial markers E-cadherin and alpha-catenin were frequently lost in hepatolithiasis (32.3% and 25.9% of cases, respectively), while the mesenchymal markers vimentin, alpha-SMA and S100A4 were found to be present in hepatolithiasis (35.5%, 29.0%, and 32.3% of cases, respectively). The increased mesenchymal marker expression was correlated with decreased epithelial marker expression. The expressions of TGF-beta1 and P-smad2/3 in hepatolithiasis were correlated with the expression of S100A4. These data indicate that TGF-beta1-mediated epithelial-mesenchymal transition might be involved in the formation of hepatolithiasis.
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Affiliation(s)
- Lijin Zhao
- Hepatobiliary Surgery Institute, Southwest Hospital, Third Military Medical University, Chongqing, China
- Affiliated Hospital of Zunyi Medical College, Zunyi, China
| | - Rigao Yang
- Department of General Surgery, The 324th Hospital of PLA, Chongqing, China
| | - Long Cheng
- Hepatobiliary Surgery Institute, Southwest Hospital, Third Military Medical University, Chongqing, China
| | - Maijian Wang
- Affiliated Hospital of Zunyi Medical College, Zunyi, China
| | - Yan Jiang
- Hepatobiliary Surgery Institute, Southwest Hospital, Third Military Medical University, Chongqing, China
| | - Shuguang Wang
- Hepatobiliary Surgery Institute, Southwest Hospital, Third Military Medical University, Chongqing, China
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Cannito S, Novo E, di Bonzo LV, Busletta C, Colombatto S, Parola M. Epithelial-mesenchymal transition: from molecular mechanisms, redox regulation to implications in human health and disease. Antioxid Redox Signal 2010; 12:1383-430. [PMID: 19903090 DOI: 10.1089/ars.2009.2737] [Citation(s) in RCA: 194] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Epithelial to mesenchymal transition (EMT) is a fundamental process, paradigmatic of the concept of cell plasticity, that leads epithelial cells to lose their polarization and specialized junctional structures, to undergo cytoskeleton reorganization, and to acquire morphological and functional features of mesenchymal-like cells. Although EMT has been originally described in embryonic development, where cell migration and tissue remodeling have a primary role in regulating morphogenesis in multicellular organisms, recent literature has provided evidence suggesting that the EMT process is a more general biological process that is also involved in several pathophysiological conditions, including cancer progression and organ fibrosis. This review offers first a comprehensive introduction to describe major relevant features of EMT, followed by sections dedicated on those signaling mechanisms that are known to regulate or affect the process, including the recently proposed role for oxidative stress and reactive oxygen species (ROS). Current literature data involving EMT in both physiological conditions (i.e., embryogenesis) and major human diseases are then critically analyzed, with a special final focus on the emerging role of hypoxia as a relevant independent condition able to trigger EMT.
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Affiliation(s)
- Stefania Cannito
- Department of Experimental Medicine and Oncology and Interuniversity Center for Hepatic Pathophysiology, University of Turin, Turin, Italy
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Strutz F. Pathogenesis of tubulointerstitial fibrosis in chronic allograft dysfunction. Clin Transplant 2010; 23 Suppl 21:26-32. [PMID: 19930313 DOI: 10.1111/j.1399-0012.2009.01106.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The term chronic allograft nephropathy (CAN) was originally coined in 1991 to replace chronic rejection which was used too generalized. However, the revised Banff classification, published in 2007, eliminated the term CAN again because it was felt that the term was used too broadly and prevented the search for the underlying cause. Interstitial fibrosis and tubular atrophy are integral parts of chronic allograft dysfunction and represent in the new classification a separate entity with or without the identification of a specific etiology. Myofibroblasts are the key, albeit not exclusive, effector cells in renal fibrogenesis resulting in upregulated extracellular matrix synthesis and eventually in interstitial fibrosis. These cells are formed mainly by stimulation of resident interstitial fibroblasts but also by differentiation processes of periadventitial cells, bone marrow derived cells and by a process entitled epithelial mesenchymal transition (EMT) of tubular epithelial cells. EMT has been described by many groups to be of high prevalence in renal allograft dysfunction contributing to matrix accumulation and renal function deterioration. This is of particular interest because immunosuppressive therapy has differential effects on EMT with calcineurin inhibitors in particular inducing the process. Moreover, specific therapies inhibiting EMT have been applied in experimental studies although the effects of their application in chronic allograft dysfunction remain to be studied. At the same time, immunosuppression may interfere with physiologic clearance of myofibroblasts by apoptosis, explaining in part the high prevalence of interstitial fibrosis in allograft biopsies. The Fas system has been identified to be mainly responsible for this physiologic apoptosis in non-renal scarring models; however, its relevance for renal fibrosis and particular fibrosis in renal allograft dysfunction remains to be determined. These findings point to a cautious and individualized use of immunosuppressive therapy in patients with allografts and particular those with chronic allograft dysfunction not because of rejection processes. Protocols using CNI-free immunosuppression are interesting options to prevent fibrosis in chronic allograft dysfunction.
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Affiliation(s)
- Frank Strutz
- Department of Nephrology, Deutsche Klinik für Diagnostik, Wiesbaden, Germany.
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Mas VR, Archer KJ, Scian M, Maluf DG. Molecular pathways involved in loss of graft function in kidney transplant recipients. Expert Rev Mol Diagn 2010; 10:269-84. [PMID: 20370585 PMCID: PMC6846360 DOI: 10.1586/erm.10.6] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Interstitial fibrosis (IF) and tubular atrophy (TA) are integral parts of chronic allograft dysfunction and represent in the new classification a separate entity with or without the identification of a specific etiology. Loss of kidney graft function with IF/TA is one of the causes of most kidney allograft losses. Despite progress in immunosuppression, chronic allograft dysfunction remains the main clinical challenge for improving long-term graft survival. The sustained damage to the allograft does not represent a single entity but the summated effects of tissue injury from several pathogenic insults, as well as the kidney's healing response, modified by alloimmunity and immunosuppression. A major challenge in the future of kidney transplantation includes the study of chronic allograft dysfunction pathogenesis to identify early markers of disease progression, as well as potential therapeutics pathways.
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Affiliation(s)
- Valeria R Mas
- Molecular Transplant Research Laboratory, Transplant Division, Department of Surgery, Molecular Medicine Research Building, Virginia Commonwealth University, Richmond, VA 23298, USA.
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Heilman RL, Devarapalli Y, Chakkera HA, Mekeel KL, Moss AA, Mulligan DC, Mazur MJ, Hamawi K, Williams JW, Reddy KS. Impact of subclinical inflammation on the development of interstitial fibrosis and tubular atrophy in kidney transplant recipients. Am J Transplant 2010; 10:563-70. [PMID: 20121731 DOI: 10.1111/j.1600-6143.2009.02966.x] [Citation(s) in RCA: 104] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Our aim was to study the impact of subclinical inflammation on the development of interstitial fibrosis and tubular atrophy (IF/TA) on a 1-year protocol biopsy in patients on rapid steroid withdrawal (RSW). A total of 256 patients were classified based on protocol biopsy findings at months 1 or 4. Group 1 is 172 patients with no inflammation, group 2 is 50 patients with subclinical inflammation (SCI), group 3 is 19 patients with subclinical acute rejection (SAR) and group 4 is 15 patients with clinical acute rejection (CAR). On the 1-year biopsy, more patients in group 2 (SCI) (34%, p = 0.004) and group 3 (SAR) (53%, p = 0.0002), had an IF/TA score > 2 compared to group 1 (control) (15%). IF/TA was not increased in group 4 (CAR) (20%). The percent with IF/TA score > 2 and interstitial inflammation (Banff i score > 0) was higher in group 2 (16%, p = 0.004) and group 3 (37%, p < 0.0001) compared to group 1 (3%). In a multivariate analysis, patients in groups 2 or 3 had a higher risk of IF/TA score > 2 on the 1-year biopsy (OR 6.62, 95% CI 2.68-16.3). We conclude that SCI and SAR increase the risk of developing IF/TA in patient on RSW.
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Affiliation(s)
- R L Heilman
- Department of Medicine, Mayo Clinic Arizona, Phoenix, AZ.
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Favreau F, Thuillier R, Cau J, Milin S, Manguy E, Mauco G, Zhu X, Lerman LO, Hauet T. Anti-thrombin therapy during warm ischemia and cold preservation prevents chronic kidney graft fibrosis in a DCD model. Am J Transplant 2010; 10:30-9. [PMID: 19958330 PMCID: PMC2807130 DOI: 10.1111/j.1600-6143.2009.02924.x] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Ischemia reperfusion injury (IRI) is pivotal for renal fibrosis development via peritubular capillaries injury. Coagulation represents a key mechanism involved in this process. Melagatran (M), a thrombin inhibitor, was evaluated in an autotransplanted kidney model, using Large White pigs. To mimic deceased after cardiac death donor conditions, kidneys underwent warm ischemia (WI) for 60 min before cold preservation for 24 h in University of Wisconsin solution. Treatment with M before WI and/or in the preservation solution drastically improved survival at 3 months, reduced renal dysfunction related to a critical reduction in interstitial fibrosis, measured by Sirius Red staining. Tissue analysis revealed reduced expression of transforming growth factor-beta (TGF-beta) and activation level of its effectors phospho-Smad3, Smad4 and connective tissue growth factor (CTGF) after M treatment. Fibrinolysis activation was also observed, evidenced by downregulation of PAI-1 protein and gene expression. In addition, M reduced S100A4 expression and vimentin staining, which are markers for epithelial mesenchymal transition, a major pathway to chronic kidney fibrosis. Finally, expression of oxidative stress markers Nox2 and iNOS was reduced. We conclude that inhibition of thrombin is an effective therapy against IRI that reduces chronic graft fibrosis, with a significantly positive effect on survival.
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Affiliation(s)
- F Favreau
- Inserm U927, Ischémie-reperfusion en transplantation rénale, Poitiers, France; Université de Poitiers Faculté de Medecine et de Pharmacie, Poitiers, France, CHU de Poitiers, Laboratoire de biochimie, Poitiers, France
| | - R Thuillier
- Inserm U927, Ischémie-reperfusion en transplantation rénale, Poitiers, France; Université de Poitiers Faculté de Medecine et de Pharmacie, Poitiers, France, CHU de Poitiers, Laboratoire de biochimie, Poitiers, France
| | - J Cau
- Inserm U927, Ischémie-reperfusion en transplantation rénale, Poitiers, France; Université de Poitiers Faculté de Medecine et de Pharmacie, Poitiers, France
| | - S Milin
- Inserm U927, Ischémie-reperfusion en transplantation rénale, Poitiers, France; Université de Poitiers Faculté de Medecine et de Pharmacie, Poitiers, France
| | - E Manguy
- Inserm U927, Ischémie-reperfusion en transplantation rénale, Poitiers, France; Université de Poitiers Faculté de Medecine et de Pharmacie, Poitiers, France
| | - G Mauco
- Inserm U927, Ischémie-reperfusion en transplantation rénale, Poitiers, France; Université de Poitiers Faculté de Medecine et de Pharmacie, Poitiers, France, CHU de Poitiers, Laboratoire de biochimie, Poitiers, France
| | - X Zhu
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota, USA
| | - LO Lerman
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota, USA
| | - T Hauet
- Inserm U927, Ischémie-reperfusion en transplantation rénale, Poitiers, France; Université de Poitiers Faculté de Medecine et de Pharmacie, Poitiers, France, Plate forme IBiSA, INRA Le Magneraud, Surgères, France, CHU de Poitiers, Laboratoire de biochimie, Poitiers, France
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89
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Liu Y. New insights into epithelial-mesenchymal transition in kidney fibrosis. J Am Soc Nephrol 2009; 21:212-22. [PMID: 20019167 DOI: 10.1681/asn.2008121226] [Citation(s) in RCA: 674] [Impact Index Per Article: 44.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Epithelial-mesenchymal transition (EMT), a process by which differentiated epithelial cells undergo a phenotypic conversion that gives rise to the matrix-producing fibroblasts and myofibroblasts, is increasingly recognized as an integral part of tissue fibrogenesis after injury. However, the degree to which this process contributes to kidney fibrosis remains a matter of intense debate and is likely to be context-dependent. EMT is often preceded by and closely associated with chronic interstitial inflammation and could be an adaptive response of epithelial cells to a hostile or changing microenvironment. In addition to tubular epithelial cells, recent studies indicate that endothelial cells and glomerular podocytes may also undergo transition after injury. Phenotypic alteration of podocytes sets them in motion to functional impairment, resulting in proteinuria and glomerulosclerosis. Several intracellular signal transduction pathways such as TGFbeta/Smad, integrin-linked kinase (ILK) and Wnt/beta-catenin signaling are essential in controlling the process of EMT and presently are potential targets of antifibrotic therapy. This review highlights the current understanding of EMT and its underlying mechanisms to stimulate further discussion on its role, not only in the pathogenesis of renal interstitial fibrosis but also in the onset of podocyte dysfunction, proteinuria, and glomerulosclerosis.
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Affiliation(s)
- Youhua Liu
- Department of Pathology, University of Pittsburgh School of Medicine, S-405 Biomedical Science Tower, 200 Lothrop Street, Pittsburgh, PA 15261, USA.
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90
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Liu M, Gu M, Wu Y, Zhu P, Zhang W, Yin C, Zhang W. Therapeutic Effect of Y-27632 on Chronic Allograft Nephropathy in Rats. J Surg Res 2009; 157:e117-27. [DOI: 10.1016/j.jss.2008.10.018] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2008] [Revised: 09/30/2008] [Accepted: 10/20/2008] [Indexed: 12/21/2022]
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91
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Factors Associated With Progression of Interstitial Fibrosis in Renal Transplant Patients Receiving Tacrolimus and Mycophenolate Mofetil. Transplantation 2009; 88:897-903. [DOI: 10.1097/tp.0b013e3181b723f4] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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92
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Veerasamy M, Nguyen TQ, Motazed R, Pearson AL, Goldschmeding R, Dockrell MEC. Differential regulation of E-cadherin and alpha-smooth muscle actin by BMP 7 in human renal proximal tubule epithelial cells and its implication in renal fibrosis. Am J Physiol Renal Physiol 2009; 297:F1238-48. [PMID: 19741012 DOI: 10.1152/ajprenal.90539.2008] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Chronic kidney diseases are characterized by progressive tubulointerstitial fibrosis, and TGFbeta1 plays a crucial role in its development. Bone morphogenic protein 7 (BMP 7), another member of the TGF superfamily, antagonized the profibrotic effects of TGFbeta1, including epithelial mesenchymal transition and E-cadherin loss, in the previous studies from animal models. We investigated the effect of BMP 7 on TGFbeta1-mediated E-cadherin loss in two different transformed human adult proximal tubule epithelia. We found that BMP 7 not only failed to prevent TGFbeta1-mediated E-cadherin loss but itself downregulated E-cadherin levels and that it had an additive effect with TGFbeta1 in inducing E-cadherin loss. The downregulation of E-cadherin by BMP 7 was mediated through the Smad1/5 pathway. BMP 7-mediated E-cadherin loss was not followed by de novo alpha-smooth muscle actin (alpha-SMA) expression (a marker of myofibroblastic phenotype), which was due to the concurrent induction of Inhibitor of DNA binding 1 (Id1, a basic helix loop helix class transcriptional regulator) through a non-Smad pathway. Concurrent treatment of BMP 7 and TGFbeta1 prevented TGFbeta1-mediated alpha-SMA induction. In summary, our results suggest that E-cadherin loss, the key feature of epithelial mesenchymal transition, will not necessarily be followed by total phenotype change; rather, cells may undergo some loss of phenotypic marker in a ligand-dependent manner and participate in reparative processes. The inhibition of de novo expression of alpha-SMA could explain the antifibrotic effect of BMP 7. Id1 might play a crucial role in maintaining proximal tubule epithelial cell phenotype and its signaling regulation could be a potential therapeutic target.
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Affiliation(s)
- Mangalakumar Veerasamy
- South West Thames Institute for Renal Research, Epsom and St. Helier University Hospitals NHS Trust, Carshalton, United Kingdom.
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93
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López-Novoa JM, Nieto MA. Inflammation and EMT: an alliance towards organ fibrosis and cancer progression. EMBO Mol Med 2009; 1:303-14. [PMID: 20049734 PMCID: PMC3378143 DOI: 10.1002/emmm.200900043] [Citation(s) in RCA: 507] [Impact Index Per Article: 33.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2009] [Revised: 08/17/2009] [Accepted: 08/26/2009] [Indexed: 12/13/2022] Open
Abstract
Recent advances in our understanding of the molecular pathways that govern the association of inflammation with organ fibrosis and cancer point to the epithelial to mesenchymal transition (EMT) as the common link in the progression of these devastating diseases. The EMT is a crucial process in the development of different tissues in the embryo and its reactivation in the adult may be regarded as a physiological attempt to control inflammatory responses and to 'heal' damaged tissue. However, in pathological contexts such as in tumours or during the development of organ fibrosis, this healing response adopts a sinister nature, steering these diseases towards metastasis and organ failure. Importantly, the chronic inflammatory microenvironment common to fibrotic and cancer cells emerges as a decisive factor in the induction of the pathological EMT.
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Affiliation(s)
- Jose Miguel López-Novoa
- Departamento de Fisiología y Farmacología, Universidad de Salamanca, Edificio Departamental, Campus Miguel de UnamunoSalamanca, Spain
| | - M Angela Nieto
- Instituto de Neurociencias CSIC-UMHSan Juan de Alicante, Spain
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94
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Guarino M, Tosoni A, Nebuloni M. Direct contribution of epithelium to organ fibrosis: epithelial-mesenchymal transition. Hum Pathol 2009; 40:1365-76. [PMID: 19695676 DOI: 10.1016/j.humpath.2009.02.020] [Citation(s) in RCA: 192] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/26/2008] [Revised: 02/15/2009] [Accepted: 02/20/2009] [Indexed: 02/06/2023]
Abstract
Fibrosis of epithelial parenchymal organs and end-stage organ failure represent the final common pathway of many chronic diseases and are a major determinant of morbidity and mortality worldwide. Fibrosis is a complex response initiated to protect the host from an injurious event; nevertheless, it leads to serious organ damage when it becomes independent from the initiating stimulus. It involves massive deposition of matrix by an expanded pool of fibrogenic cells, disruption of the normal tissue architecture, and parenchymal destruction. Fibroblasts, the effector cells of matrix production, when engaged in fibrogenesis, display the highly activated phenotype characteristic of myofibroblasts. These cells are present in a large number in sites with ongoing inflammation, reparative reaction, and fibrosis, but their origin has not yet been definitely elucidated. Although proliferation of preexisting stromal fibroblasts and, probably, recruitment of bone marrow-derived fibrogenic cells may account for a portion of them, emerging evidence seems to indicate that an important number of matrix-producing fibroblasts/myofibroblasts arises through a mechanism of epithelial-mesenchymal transition. Through this process, epithelial cells would lose intercellular cohesion and would translocate from the epithelial compartment into the interstitium where, gaining a full mesenchymal phenotype, they could participate in the synthesis of the fibrotic matrix. Epithelial-mesenchymal transition is induced by the integrated actions of many stimuli including transforming growth factor-beta and matrix-generated signals that are also known to be implicated in inflammation, repair responses, and fibrosis. The consequences of epithelial-mesenchymal transition in chronic fibrosing diseases could be two-fold as follows: on one hand, by supplementing new mesenchymal cells, it might feed the expanding pool of interstitial fibroblasts/myofibroblasts responsible for the matrix accumulation; on the other hand, it could cause loss of epithelial cells, thus, contributing to the parenchyma destruction seen in advanced fibrosis. Markers of epithelium undergoing epithelial-mesenchymal transition include loss of E-cadherin and cytokeratin; de novo expression of fibroblast-specific protein 1/S100A4, vimentin, and alpha-smooth muscle actin; basement membrane component loss; and production of interstitial-type matrix molecules such as fibronectin and type I/III collagen. Evidence of epithelial-mesenchymal transition has been reported in the kidney, lung, liver, eye, and serosal membranes suggesting that epithelial-mesenchymal transition could be involved in the pathogenesis of fibrotic disorders in these organs. Thus, because of its fibrogenic potential, the detection of epithelial-mesenchymal transition in biopsy specimens could be useful diagnostically and represent a new biomarker of progression in chronic fibrosing diseases.
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Affiliation(s)
- Marcello Guarino
- Department of Pathology, Hospital of Vimercate, Vimercate, Milan, Italy.
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95
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Grande MT, López-Novoa JM. Fibroblast activation and myofibroblast generation in obstructive nephropathy. Nat Rev Nephrol 2009; 5:319-28. [PMID: 19474827 DOI: 10.1038/nrneph.2009.74] [Citation(s) in RCA: 210] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Obstructive nephropathy is a major cause of renal failure, particularly in newborn babies and children. After urinary tract obstruction, and under the influence of mechanical forces and cytokines produced by tubular cells and cells that have infiltrated the interstitium, resident fibroblasts undergo activation and myofibroblasts are generated from bone-marrow-derived cells, pericytes and endothelial cells. In addition, selected tubular epithelial cells can become fibroblast-like cells via epithelial-mesenchymal transition. This transition is characterized by downregulation of epithelial marker proteins such as E-cadherin, zonula occludens 1 and cytokeratin; loss of cell-to-cell adhesion; upregulation of mesenchymal markers including vimentin, alpha-smooth muscle actin and fibroblast-specific protein 1; basement membrane degradation; and migration to the interstitial compartment. All the events of epithelial-mesenchymal transition are strictly regulated by complex signaling pathways. Myofibroblasts and activated fibroblasts proliferate and produce large amounts of extracellular matrix, which accumulates in the tubular interstitium; together with tubular atrophy, this accumulation leads to interstitial fibrosis. This Review examines the molecular mechanisms of fibroblast activation and epithelial-mesenchymal transition, processes that seem to be promising targets for the prevention, or even reversal, of interstitial fibrosis and renal dysfunction associated with obstructive nephropathy.
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Affiliation(s)
- María T Grande
- Instituto Reina Sofía de investigación Nefrológica, Departamento de Fisiología y Farmacología, Universidad de Salamanca, Salamanca 37007, Spain
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96
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Hertig A, Gangadhar T, Kalluri R. Renal studies provide an insight into cardiac extracellular matrix remodeling during health and disease. J Mol Cell Cardiol 2009; 48:497-503. [PMID: 19646990 DOI: 10.1016/j.yjmcc.2009.07.022] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/07/2009] [Revised: 07/02/2009] [Accepted: 07/18/2009] [Indexed: 12/16/2022]
Abstract
The remodeling of a heart ventricle after myocardial infarction involves numerous inflammatory mediators that may trigger a long-lasting and a highly fibrogenic process. Likewise, in the kidney, acute and chronic injuries may lead to abnormal extracellular matrix deposition and eventually lead to the loss of renal function. Major breakthroughs have emerged during the last ten years with respect to the pathophysiology of matrix remodeling. Epithelial and endothelial cells are plastic, and able to engage in epithelial (or endothelial)-to-mesenchymal transition (EMT or EndMT), thus actively contributing to the fibrogenesis. Members of the fibrinolytic system were demonstrated to possess unsuspected properties and interact with receptors and integrins on endothelial and epithelial cells. Finally, a notion that stem cells could integrate into damaged tissue has recently emerged, which likely contributes to the tissue repair. In many aspects, the kidney and the heart share many common injury mechanisms. We envision that some of them will be accessible as common therapeutic targets in the future.
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Affiliation(s)
- Alexandre Hertig
- Division of Matrix Biology, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA 02115, USA
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97
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Abstract
Rapid advances have been made in decreasing acute rejection rates and improving short-term graft survival in kidney transplant recipients. Whether these advances ultimately will lead to a commensurate improvement in long-term survival is not yet known. In recent years, greater attention has been placed on defining the precise etiology of graft loss, determining how far and with what agents we can minimize immunosuppression, and delineating the nature of both T-cell-mediated as well as antibody-mediated rejection. In addition, with the growing disparity of available organs and patients in need of a transplant, greater attention has been placed on optimizing allocation. In this minireview, we will focus on developments over the last couple of years, paying particular attention to insights, studies and observations that may attempt to elucidate some of these open questions.
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Affiliation(s)
- Karl L. Womer
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Bruce Kaplan
- Departments of Medicine, Surgery, and Pharmacology, University of Arizona School of Medicine, Tucson, AZ
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98
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Scherer A, Gwinner W, Mengel M, Kirsch T, Raulf F, Szustakowski JD, Hartmann N, Staedtler F, Engel G, Klupp J, Korn A, Kehren J, Haller H. Transcriptome changes in renal allograft protocol biopsies at 3 months precede the onset of interstitial fibrosis/tubular atrophy (IF/TA) at 6 months. Nephrol Dial Transplant 2009; 24:2567-75. [DOI: 10.1093/ndt/gfp183] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
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99
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Nakao A, Faleo G, Nalesnik MA, Seda-Neto J, Kohmoto J, Murase N. Low-dose carbon monoxide inhibits progressive chronic allograft nephropathy and restores renal allograft function. Am J Physiol Renal Physiol 2009; 297:F19-26. [PMID: 19369289 DOI: 10.1152/ajprenal.90728.2008] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Chronic allograft nephropathy (CAN) represents progressive deterioration of renal allograft function with fibroinflammatory changes. CAN, recently reclassified as interstitial fibrosis (IF) and tubular atrophy (TA) with no known specific etiology, is a major cause of late renal allograft loss and remains a significant deleterious factor of successful renal transplantation. Carbon monoxide (CO), an effector byproduct of heme oxygenase pathway, is known to have potent anti-inflammatory and antifibrotic functions. We hypothesized that inhaled CO would inhibit fibroinflammatory process of CAN and restore renal allograft function, even when the treatment was initiated after CAN was established. Lewis rat kidney grafts were orthotopically transplanted into binephrectomized allogenic Brown Norway rats under brief tacrolimus (0.5 mg/kg im, days 0-6). At day 60, CO (20 ppm) inhalation was initiated to recipients and continued until day 150 or animal death. Development of CAN was confirmed at day 60 with decreased creatinine clearance (CCr), significant proteinuria, and histopathological findings of TA, IF, and intimal arteritis. Air-treated control recipients continued to deteriorate with further declines of CCr and increases of urinary protein excretion and died with a median survival of 82 days. In contrast, progression of CAN was decelerated when recipients received CO on days 60-150, showing markedly improved graft histopathology, restored renal function, and improved recipient survival to a median of >150 days. CO significantly reduced intragraft mRNA levels for IFN-gamma and TNF-alpha at day 90. Expression of profibrotic TGF-beta/Smad was significantly suppressed with CO, together with downregulation of ERK-MAPK pathways. Continuous CO (20 ppm) treatment for days 0-30, days 30-60, or days 0-90, or daily 1-h CO (250 ppm) treatment for days 0-90, also showed efficacy in inhibiting CAN. The study demonstrates that CO is able to inhibit progression of fibroinflammatory process of CAN, restore renal allograft function, and improve survival even when the treatment is started after CAN is diagnosed.
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Affiliation(s)
- Atsunori Nakao
- Department of Surgery, Thomas E. Starzl Transplantation Institute, University of Pittsburgh Medical Center, Pittsburgh, PA 15213, USA
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100
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Chea SW, Lee KB. TGF-beta mediated epithelial-mesenchymal transition in autosomal dominant polycystic kidney disease. Yonsei Med J 2009; 50:105-11. [PMID: 19259356 PMCID: PMC2649848 DOI: 10.3349/ymj.2009.50.1.105] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/18/2008] [Accepted: 07/14/2008] [Indexed: 12/22/2022] Open
Abstract
PURPOSE Recent studies have showed that epithelial-mesenchymal transition (EMT) is a key process of glomerular and tubulointerstitial pathology in many chronic kidney diseases. However, there are no data of EMT in humane autosomal dominant polycystic kidney disease (ADPKD). PATIENTS AND METHODS ADPKD kidneys (N = 5) with end stage renal disease (ESRD) and control kidneys (N = 4) were analyzed immnunohistochemically. We evaluated alpha-SMA, E-cadherin, vimentin, TGF-beta1 and Smad 2/3 expression in ADPKD and compared them with those in control kidney. These immunohistochemical findings were quantitatively analyzed by computer-assisted image analyzer and positive tubules (%). RESULTS There were severe interstitial fibrosis and proliferation of alpha-SMA+ myofibroblasts in ADPKD. Cystic tubular epithelial cells in ADPKD lost epithelial marker (E-cadherin) and expressed mesenchymal markers (alpha-SMA, vimentin). There were significant increases of alpha-SMA (34.3 +/- 11.7% vs 0.9 +/- 1.5%), vimentin (19.9 +/- 3.9% vs 3.3 +/- 1.4%), TGF-beta1 (5.42 +/- 2.83% vs 0%) and Smad 2/3 (3.4 +/- 1.7% vs 0.7 +/- 0.6%) in ADPKD kidneys compared with control kidneys evidenced by computer-assisted image analyzer. When we analyze the positive tubules (%), the results were the same as computer-assisted image analyzer. CONCLUSION Our results showed that the end stage of ADPKD is associated with TGF-beta, Smad 2/3 and markers of EMT. It suggests that TGF-beta mediated EMT has a role in progression of ADPKD.
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Affiliation(s)
- Seung Wan Chea
- Department of Pathology, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Kyu-Beck Lee
- Department of Internal Medicine, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea
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