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Bartis D, Mise N, Mahida RY, Eickelberg O, Thickett DR. Epithelial-mesenchymal transition in lung development and disease: does it exist and is it important? Thorax 2013; 69:760-5. [PMID: 24334519 DOI: 10.1136/thoraxjnl-2013-204608] [Citation(s) in RCA: 235] [Impact Index Per Article: 21.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Epithelial-mesenchymal transition (EMT) is a process when epithelial cells gradually transform into mesenchymal-like cells losing their epithelial functionality and characteristics. EMT is thought to be involved in the pathogenesis of numerous lung diseases ranging from developmental disorders, fibrotic tissue remodelling to lung cancer. The most important question--namely what is the importance and contribution of EMT in the pathogenesis of several chronic lung conditions (asthma, COPD, bronchiolitis obliterans syndrome and lung fibrosis)--is currently intensely debated. This review gives a brief insight into the mechanism and assessment methods of EMT in various pulmonary diseases and summarises the recent literature highlighting the controversial experimental data and conclusions.
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Affiliation(s)
- Domokos Bartis
- Department of Clinical Respiratory Sciences, Centre for Translational Inflammation and Fibrosis Research, School of Clinical and Experimental Medicine, University of Birmingham, Birmingham, UK
| | - Nikica Mise
- Comprehensive Pneumology Center, University Hospital, Ludwig-Maximilians University and Helmholtz Zentrum, München, Germany
| | - Rahul Y Mahida
- Department of Clinical Respiratory Sciences, Centre for Translational Inflammation and Fibrosis Research, School of Clinical and Experimental Medicine, University of Birmingham, Birmingham, UK
| | - Oliver Eickelberg
- Comprehensive Pneumology Center, University Hospital, Ludwig-Maximilians University and Helmholtz Zentrum, München, Germany
| | - David R Thickett
- Department of Clinical Respiratory Sciences, Centre for Translational Inflammation and Fibrosis Research, School of Clinical and Experimental Medicine, University of Birmingham, Birmingham, UK
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102
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Mesenchymal cells emerge as primary contributors to fibrosis in multiple tissues. J Cell Commun Signal 2013; 8:3-4. [PMID: 24318933 DOI: 10.1007/s12079-013-0219-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2013] [Accepted: 11/27/2013] [Indexed: 01/06/2023] Open
Abstract
A longstanding controversy exists regarding the cellular origin of myofibroblasts in tissue fibrosis. A recent study by Hung and colleagues (Am J Respir Crit Care Med 188(7):820-830, 2013) used genetic fate mapping of FoxD1 embryonic progenitor cells to show a major and direct contribution of mesenchymal cells to fibrogenesis in the lung. Future studies using FoxD1-specific inducible knockout models of pro-fibrotic genes such as CCN2 will be valuable for determining anti-fibrotic drug targets. The emergence of pericyte-like myofibroblast precursors also raises the question of whether mesenchymal stem cells in various niches contribute to fibrotic responses throughout the body.
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103
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Wang C, Blough ER, Arvapalli R, Dai X, Paturi S, Manne N, Addagarla H, Triest WE, Olajide O, Wu M. Metabolic syndrome-induced tubulointerstitial injury: role of oxidative stress and preventive effects of acetaminophen. Free Radic Biol Med 2013; 65:1417-1426. [PMID: 24140865 DOI: 10.1016/j.freeradbiomed.2013.10.005] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/05/2013] [Revised: 10/01/2013] [Accepted: 10/03/2013] [Indexed: 11/17/2022]
Abstract
The prevalence of metabolic syndrome persistently increases and affects over 30% of U.S. adults. To study how metabolic syndrome may induce tubulointerstitial injury and whether acetaminophen has renal-protective properties, 4-week-old obese Zucker rats were randomly assigned into three groups, control (OC), vehicle dimethyl sulfoxide (OV), and acetaminophen treatment (30 mg/kg/day for 26 weeks), and lean Zucker rats served as healthy controls. Significant tubulointerstitial injuries were observed in both OC and OV animals, evidenced by increased tubular cell death, tubular atrophy/dilation, inflammatory cell infiltration, and fibrosis. These tubulointerstitial alterations were significantly reduced by treatment with a chronic but low dose of acetaminophen, which acted to diminish NADPH oxidase isoforms Nox2 and Nox4 and decrease tubulointerstitial oxidative stress (reduced tissue superoxide and macromolecular oxidation). Decreased oxidative stress by acetaminophen was paralleled by the reduction of tubular proapoptotic signaling (diminished Bax/Bcl-2 ratio and caspase 3 activation) and the alleviation of tubular epithelial-to-mesenchymal transition (decreased transforming growth factor β, connective tissue growth factor, α-smooth muscle actin, and laminin). These data suggest that increased oxidative stress plays a critical role in mediating metabolic syndrome-induced tubulointerstitial injury and provide the first evidence suggesting that acetaminophen may be of therapeutic benefit for the prevention of tubulointerstitial injury.
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Affiliation(s)
- Cuifen Wang
- Center for Diagnostic Nanosystems, Marshall University, Huntington, WV 25755, USA; School of Pharmacy, Marshall University, Huntington, WV 25755, USA; Southeast University, Nanjing, Jiangsu, China
| | - Eric R Blough
- Center for Diagnostic Nanosystems, Marshall University, Huntington, WV 25755, USA; School of Pharmacy, Marshall University, Huntington, WV 25755, USA.
| | - Ravikumar Arvapalli
- Center for Diagnostic Nanosystems, Marshall University, Huntington, WV 25755, USA; School of Pharmacy, Marshall University, Huntington, WV 25755, USA
| | - Xiaoniu Dai
- Southeast University, Nanjing, Jiangsu, China
| | - Satyanarayana Paturi
- Center for Diagnostic Nanosystems, Marshall University, Huntington, WV 25755, USA
| | - Nandini Manne
- Center for Diagnostic Nanosystems, Marshall University, Huntington, WV 25755, USA; Joan C. Edwards School of Medicine, Marshall University, Huntington, WV 25755, USA
| | - Hari Addagarla
- Center for Diagnostic Nanosystems, Marshall University, Huntington, WV 25755, USA
| | - William E Triest
- Huntington Veterans Affairs Medical Center, Huntington, WV 25704, USA
| | - Omolola Olajide
- Joan C. Edwards School of Medicine, Marshall University, Huntington, WV 25755, USA
| | - Miaozong Wu
- Center for Diagnostic Nanosystems, Marshall University, Huntington, WV 25755, USA; School of Pharmacy, Marshall University, Huntington, WV 25755, USA; Joan C. Edwards School of Medicine, Marshall University, Huntington, WV 25755, USA.
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104
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Zhou YN, Mu YP, Liu P. Sources of myofibroblasts in liver fibrosis. Shijie Huaren Xiaohua Zazhi 2013; 21:3376-3382. [DOI: 10.11569/wcjd.v21.i31.3376] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Myofibroblasts (MFBs) promote the accumulation of the extracellular matrix (ECM) by synthesis and secretion of collagen in the liver, leading to liver fibrosis. Activated hepatic stellate cells (HSC) are the major source of MFBs, and also play a key role in the development of liver fibrosis. Many studies indicate that hepatocytes and bile duct cells may undergo epithelial-to-mesenchymal transition (EMT) to MFBs; however, contrary conclusions have also been drawn in recent studies. In addition, other sources of MFBs have also been found, including portal fibroblasts, bone marrow cells, and hepatic progenitor cells. In this article we will review the sources of MFBs in liver fibrosis.
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105
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Souma T, Yamazaki S, Moriguchi T, Suzuki N, Hirano I, Pan X, Minegishi N, Abe M, Kiyomoto H, Ito S, Yamamoto M. Plasticity of renal erythropoietin-producing cells governs fibrosis. J Am Soc Nephrol 2013; 24:1599-616. [PMID: 23833259 PMCID: PMC3785278 DOI: 10.1681/asn.2013010030] [Citation(s) in RCA: 151] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2013] [Accepted: 04/24/2013] [Indexed: 12/31/2022] Open
Abstract
CKD progresses with fibrosis and erythropoietin (Epo)-dependent anemia, leading to increased cardiovascular complications, but the mechanisms linking Epo-dependent anemia and fibrosis remain unclear. Here, we show that the cellular phenotype of renal Epo-producing cells (REPs) alternates between a physiologic Epo-producing state and a pathologic fibrogenic state in response to microenvironmental signals. In a novel mouse model, unilateral ureteral obstruction-induced inflammatory milieu activated NFκB and Smad signaling pathways in REPs, rapidly repressed the Epo-producing potential of REPs, and led to myofibroblast transformation of these cells. Moreover, we developed a unique Cre-based cell-fate tracing method that marked current and/or previous Epo-producing cells and revealed that the majority of myofibroblasts are derived from REPs. Genetic induction of NFκB activity selectively in REPs resulted in myofibroblastic transformation, indicating that NFκB signaling elicits a phenotypic switch. Reversing the unilateral ureteral obstruction-induced inflammatory microenvironment restored the Epo-producing potential and the physiologic phenotype of REPs. This phenotypic reversion was accelerated by anti-inflammatory therapy. These findings demonstrate that REPs possess cellular plasticity, and suggest that the phenotypic transition of REPs to myofibroblasts, modulated by inflammatory molecules, underlies the connection between anemia and renal fibrosis in CKD.
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Affiliation(s)
- Tomokazu Souma
- Department of Medical Biochemistry
- Division of Nephrology, Endocrinology, and Vascular Medicine, Department of Medicine
| | | | | | - Norio Suzuki
- Division of Interdisciplinary Medical Science, United Centers for Advanced Research and Translational Medicine, and
| | | | - Xiaoqing Pan
- Department of Medical Biochemistry
- Tohoku Medical Megabank Organization, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan; and
| | - Naoko Minegishi
- Department of Medical Biochemistry
- Tohoku Medical Megabank Organization, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan; and
| | - Michiaki Abe
- Division of Nephrology, Endocrinology, and Vascular Medicine, Department of Medicine
- Tohoku Medical Megabank Organization, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan; and
| | - Hideyasu Kiyomoto
- Division of Nephrology, Endocrinology, and Vascular Medicine, Department of Medicine
- Tohoku Medical Megabank Organization, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan; and
| | - Sadayoshi Ito
- Division of Nephrology, Endocrinology, and Vascular Medicine, Department of Medicine
| | - Masayuki Yamamoto
- Department of Medical Biochemistry
- Tohoku Medical Megabank Organization, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan; and
- JST, CREST, Sendai, Miyagi, Japan
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106
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Trepiccione F, Capasso G, Nielsen S, Christensen BM. Evaluation of cellular plasticity in the collecting duct during recovery from lithium-induced nephrogenic diabetes insipidus. Am J Physiol Renal Physiol 2013; 305:F919-29. [DOI: 10.1152/ajprenal.00152.2012] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The cellular morphology of the collecting duct is altered by chronic lithium treatment. We have previously shown that lithium increases the fraction of type-A intercalated cells and lowers the fraction of principal cells along the collecting duct. Moreover, type-A intercalated cells acquire a long-row distribution pattern along the tubules. In the present study, we show that these morphological changes reverse progressively after discontinuation of lithium and finally disappear after 19 days from lithium suspension. In this time frame we have identified for the first time, in vivo, a novel cellular type positive for both intercalated and principal cells functional markers, as recognized by colabeling with H+-ATPase/aquaporin-4 (AQP4) and anion exchanger-1 (AE-1)/AQP2 and Foxi1/AQP4. This cell type is mainly present after 6 days of lithium washout, and it disappears in parallel with the long-row pattern of the type-A intercalated cells. It usually localizes either in the middle or at the edge of the long-row pattern. Its ultrastructure resembles the intercalated cells as shown both by differential interference contrast and by electron microscopy. The time course of appearance, the localization along the collecting duct, and the ultrastructure suggest that the cells double labeled for principal and intercalated cells markers could represent a transition element driving the conversion of intercalated cells into principal cells.
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Affiliation(s)
- Francesco Trepiccione
- The Water and Salt Research Center, Department of Biomedicine, Aarhus University, Aarhus, Denmark
- Department of Cardiothoracic and Respiratory Science, Second University of Naples, Naples, Italy
| | - Giovambattista Capasso
- Department of Cardiothoracic and Respiratory Science, Second University of Naples, Naples, Italy
| | - Søren Nielsen
- The Water and Salt Research Center, Department of Biomedicine, Aarhus University, Aarhus, Denmark
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107
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Speight P, Nakano H, Kelley TJ, Hinz B, Kapus A. Differential topical susceptibility to TGFβ in intact and injured regions of the epithelium: key role in myofibroblast transition. Mol Biol Cell 2013; 24:3326-36. [PMID: 24006486 PMCID: PMC3814143 DOI: 10.1091/mbc.e13-04-0220] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Intact and cell contact–deprived regions of an epithelial monolayer are differentially sensitive to the transforming effect of TGFβ. This topical susceptibility is mediated by the interplay between TGFβ- and cell contact–dependent transcription factors and might play a key role in the cell biology of wound healing and fibrosis. Induction of epithelial–myofibroblast transition (EMyT), a robust fibrogenic phenotype change hallmarked by α-smooth muscle actin (SMA) expression, requires transforming growth factor-β1 (TGFβ) and the absence/uncoupling of intracellular contacts. This suggests that an “injured” epithelium may be topically susceptible to TGFβ. To explore this concept, we use an epithelial wound model in which intact and contact-deprived regions of the same monolayer can be analyzed simultaneously. We show that TGFβ elicits dramatically different responses at these two loci. SMA expression and initially enhanced nuclear Smad3 accumulation followed by Smad3 mRNA and protein down-regulation occur exclusively at the wound. Mechanistically, three transcriptional coactivators whose localization is regulated by cell contact integrity are critical for these local effects. These are myocardin-related transcription factor (MRTF), the driver of the SMA promoter; β-catenin, which counteracts the known inhibitory effect of Smad3 on MRTF and maintains MRTF protein stability and mRNA expression in the wound; and TAZ, a Hippo effector and Smad3 retention factor. Remarkably, active TAZ stimulates the SMA and suppresses the Smad3 promoter, whereas TAZ silencing prevents wound-restricted expression of SMA and loss of Smad3. Such locus-specific reprogramming might play key roles in wound healing and the susceptibility of the injured epithelium to fibrogenesis.
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Affiliation(s)
- Pam Speight
- Keenan Research Centre, Li Ka Shing Knowledge Institute, St. Michael's Hospital, and Department of Surgery, University of Toronto, Toronto, ON M5B 1W8, Canada Department of Immunology, Juntendo University School of Medicine, Tokyo 113-8421, Japan Division of Pediatric Pulmonology, Case Western Reserve University, Cleveland, OH 44106 Laboratory of Tissue Repair and Regeneration, Matrix Dynamics Group, Faculty of Dentistry, University of Toronto, Toronto, ON M5S 3E2, Canada
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108
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Hinz B. Matrix mechanics and regulation of the fibroblast phenotype. Periodontol 2000 2013; 63:14-28. [DOI: 10.1111/prd.12030] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/25/2012] [Indexed: 01/17/2023]
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109
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110
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Hosper NA, van den Berg PP, de Rond S, Popa ER, Wilmer MJ, Masereeuw R, Bank RA. Epithelial-to-mesenchymal transition in fibrosis: collagen type I expression is highly upregulated after EMT, but does not contribute to collagen deposition. Exp Cell Res 2013; 319:3000-9. [PMID: 23906925 DOI: 10.1016/j.yexcr.2013.07.014] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2013] [Revised: 07/14/2013] [Accepted: 07/19/2013] [Indexed: 01/11/2023]
Abstract
The hallmark of fibrosis is an accumulation of fibrillar collagens, especially of collagen type I. There is considerable debate whether in vivo type II epithelial-to-mesenchymal transition (EMT) is involved in organ fibrosis. Lineage tracing experiments by various groups show opposing data concerning the relative contribution of epithelial cells to the pool of myofibroblasts. We hypothesized that EMT-derived cells might directly contribute to collagen deposition. To study this, EMT was induced in human epithelial lung and renal cell lines in vitro by means of TGF-β1 stimulation, and we compared the collagen type I (COL1A1) expression levels of transdifferentiated cells with that of myofibroblasts obtained by TGF-β1 stimulation of human dermal and lung fibroblasts. COL1A1 expression levels of transdifferentiated epithelial cells appeared to be at least one to two orders of magnitude lower than that of myofibroblasts. This was confirmed at immunohistochemical level: in contrast to myofibroblasts, collagen type I deposition by EMT-derived cells was not or hardly detectable. We postulate that, even when type II EMT occurs in vivo, the direct contribution of EMT-derived cells to collagen accumulation is rather limited.
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Affiliation(s)
- Nynke A Hosper
- Department of Pathology and Medical Biology, Medical Biology Section, University Medical Centre Groningen, University of Groningen, Hanzeplein 1, 9713 GZ Groningen, The Netherlands.
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111
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Abstract
Renal anemia has been recognized as a characteristic complication of chronic kidney disease. Although many factors are involved in renal anemia, the predominant cause of renal anemia is a relative deficiency in erythropoietin (EPO) production. To date, exogenous recombinant human (rh)EPO has been widely used as a powerful drug for the treatment of patients with renal anemia. Despite its clinical effectiveness, a potential risk for increased mortality has been suggested in patients who receive rhEPO, in addition to the economic burden of rhEPO administration. The induction of endogenous EPO is another therapeutic approach that might have advantages over rhEPO administration. However, the physiological and pathophysiological regulation of EPO are not fully understood, and this lack of understanding has hindered the development of an endogenous EPO inducer. In this review, we will discuss the current treatment for renal anemia and its drawbacks, provide an overview of EPO regulation in healthy and diseased conditions, and propose future directions for therapeutic trials that more directly target the underlying pathophysiology of renal anemia.
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Affiliation(s)
- Yuki Sato
- 54 Shogoin Kawahara-cho, Sakyo-ku, Kyoto 606-8507, Japan.
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112
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Li Y, Sun Y, Liu F, Sun L, Li J, Duan S, Liu H, Peng Y, Xiao L, Liu Y, Xi Y, You Y, Li H, Wang M, Wang S, Hou T. Norcantharidin inhibits renal interstitial fibrosis by blocking the tubular epithelial-mesenchymal transition. PLoS One 2013; 8:e66356. [PMID: 23825538 PMCID: PMC3692527 DOI: 10.1371/journal.pone.0066356] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2012] [Accepted: 05/05/2013] [Indexed: 01/20/2023] Open
Abstract
Epithelial–mesenchymal transition (EMT) is thought to contribute to the progression of renal tubulointerstitial fibrosis. Norcantharidin (NCTD) is a promising agent for inhibiting renal interstitial fibrosis. However, the molecular mechanisms of NCTD are unclear. In this study, a unilateral ureteral obstruction (UUO) rat model was established and treated with intraperitoneal NCTD (0.1 mg/kg/day). The UUO rats treated with NCTD showed a reduction in obstruction-induced upregulation of α-SMA and downregulation of E-cadherin in the rat kidney (P<0.05). Human renal proximal tubule cell lines (HK-2) stimulated with TGF-β1 were treated with different concentrations of NCTD. HK-2 cells stimulated by TGF-β1 in vitro led to downregulation of E-cadherin and increased de novo expression of α-SMA; co-treatment with NCTD attenuated all of these changes (P<0.05). NCTD reduced TGF-β1-induced expression and phosphorylation of Smad2/3 and downregulated the expression of Snail1 (P<0.05). These results suggest that NCTD antagonizes tubular EMT by inhibiting the Smad pathway. NCTD may play a critical role in preserving the normal epithelial phenotype and modulating tubular EMT.
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Affiliation(s)
- Ying Li
- Division of Nephrology, Second Xiangya Hospital, Central South University, Changsha, PR China. mail:
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Abstract
PURPOSE OF REVIEW Pathological deposition of fibrous matrix in organs is a major problem and contributes to as many as 45% of all natural deaths. Chronic kidney disease affects 8% of the US population, and is characterized by fibrotic processes. It frequently progresses to organ failure and is a major cause of cardiovascular death; yet it lacks therapies. Understanding the pathological mechanisms of fibrosis in the kidney and other organs is central to the development of new therapeutics. RECENT FINDINGS Pericytes are mesenchymal cells that partially cover capillary walls. Pericytes play critical roles in micro-vessel formation, maturation and stability. New genetic fate-mapping studies have identified pericytes and the closely related resident fibroblasts as the major progenitors of scar-forming myofibroblasts in multiple organs including the kidney, appearing in response to tissue injury. When pericytes become myofibroblasts they lose pericyte functions. Capillaries become unstable with deleterious consequences for the kidney. The cellular and molecular mechanisms underpinning these processes are starting to unravel, leading to new therapeutics for chronic fibrosing diseases of the kidney and potentially other organs. SUMMARY This review focuses on pericytes in the kidney and other organs, their role in fibrogenesis and their role in regulation of the microvasculature.
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114
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Jiang L, Xu L, Mao J, Li J, Fang L, Zhou Y, Liu W, He W, Zhao AZ, Yang J, Dai C. Rheb/mTORC1 signaling promotes kidney fibroblast activation and fibrosis. J Am Soc Nephrol 2013; 24:1114-26. [PMID: 23661807 DOI: 10.1681/asn.2012050476] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Ras homolog enriched in brain (Rheb) is a small GTPase that regulates cell growth, differentiation, and survival by upregulating mammalian target of rapamycin complex 1 (mTORC1) signaling. The role of Rheb/mTORC1 signaling in the activation of kidney fibroblasts and the development of kidney fibrosis remains largely unknown. In this study, we found that Rheb/mTORC1 signaling was activated in interstitial myofibroblasts from fibrotic kidneys. Treatment of rat kidney interstitial fibroblasts (NRK-49F cell line) with TGFβ1 also activated Rheb/mTORC1 signaling. Blocking Rheb/mTORC1 signaling with rapamycin or Rheb small interfering RNA abolished TGFβ1-induced fibroblast activation. In a transgenic mouse, ectopic expression of Rheb activated kidney fibroblasts. These Rheb transgenic mice exhibited increased activation of mTORC1 signaling in both kidney tubular and interstitial cells as well as progressive interstitial renal fibrosis; rapamycin inhibited these effects. Similarly, mice with fibroblast-specific deletion of Tsc1, a negative regulator of Rheb, exhibited activated mTORC1 signaling in kidney interstitial fibroblasts and increased renal fibrosis, both of which rapamycin abolished. Taken together, these results suggest that Rheb/mTORC1 signaling promotes the activation of kidney fibroblasts and contributes to the development of interstitial fibrosis, possibly providing a therapeutic target for progressive renal disease.
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Affiliation(s)
- Lei Jiang
- Center for Kidney Disease, Second Affiliated Hospital, Nanjing Medical University, Nanjing, Jiangsu, China
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115
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Siletz A, Schnabel M, Kniazeva E, Schumacher AJ, Shin S, Jeruss JS, Shea LD. Dynamic transcription factor networks in epithelial-mesenchymal transition in breast cancer models. PLoS One 2013; 8:e57180. [PMID: 23593114 PMCID: PMC3620167 DOI: 10.1371/journal.pone.0057180] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2012] [Accepted: 01/17/2013] [Indexed: 12/11/2022] Open
Abstract
The epithelial-mesenchymal transition (EMT) is a complex change in cell differentiation that allows breast carcinoma cells to acquire invasive properties. EMT involves a cascade of regulatory changes that destabilize the epithelial phenotype and allow mesenchymal features to manifest. As transcription factors (TFs) are upstream effectors of the genome-wide expression changes that result in phenotypic change, understanding the sequential changes in TF activity during EMT provides rich information on the mechanism of this process. Because molecular interactions will vary as cells progress from an epithelial to a mesenchymal differentiation program, dynamic networks are needed to capture the changing context of molecular processes. In this study we applied an emerging high-throughput, dynamic TF activity array to define TF activity network changes in three cell-based models of EMT in breast cancer based on HMLE Twist ER and MCF-7 mammary epithelial cells. The TF array distinguished conserved from model-specific TF activity changes in the three models. Time-dependent data was used to identify pairs of TF activities with significant positive or negative correlation, indicative of interdependent TF activity throughout the six-day study period. Dynamic TF activity patterns were clustered into groups of TFs that change along a time course of gene expression changes and acquisition of invasive capacity. Time-dependent TF activity data was combined with prior knowledge of TF interactions to construct dynamic models of TF activity networks as epithelial cells acquire invasive characteristics. These analyses show EMT from a unique and targetable vantage and may ultimately contribute to diagnosis and therapy.
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Affiliation(s)
- Anaar Siletz
- Department of Chemical and Biological Engineering, McCormick School of Engineering, Northwestern University, Evanston, Illinois, United States of America
- Medical Scientist Training Program, Northwestern University Feinberg School of Medicine, Chicago, Illinois, United States of America
| | - Michael Schnabel
- Physical Sciences – Oncology Center, Northwestern Institute on Complex Systems, Departments of Applied Mathematics and Physics, Northwestern University, Evanston, Illinois, United States of America
| | - Ekaterina Kniazeva
- Department of Chemical and Biological Engineering, McCormick School of Engineering, Northwestern University, Evanston, Illinois, United States of America
| | - Andrew J. Schumacher
- Northwestern University Feinberg School of Medicine, Chicago, Illinois, United States of America
| | - Seungjin Shin
- Department of Chemical and Biological Engineering, McCormick School of Engineering, Northwestern University, Evanston, Illinois, United States of America
| | - Jacqueline S. Jeruss
- Department of Surgery, Robert H. Lurie Comprehensive Cancer Center, Northwestern University Feinberg School of Medicine, Chicago, Illinois, United States of America
- Robert H. Lurie Comprehensive Cancer Center, Northwestern University, Chicago, Illinois, United States of America
| | - Lonnie D. Shea
- Department of Chemical and Biological Engineering, McCormick School of Engineering, Northwestern University, Evanston, Illinois, United States of America
- Robert H. Lurie Comprehensive Cancer Center, Northwestern University, Chicago, Illinois, United States of America
- Institute for BioNanotechnology in Medicine (IBNAM), Northwestern University, Chicago, Illinois, United States of America
- Chemistry of Life Processes Institute, Northwestern University, Evanston, Illinois, United States of America
- * E-mail:
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116
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Strauch AR, Hariharan S. Dynamic Interplay of Smooth Muscle α-Actin Gene-Regulatory Proteins Reflects the Biological Complexity of Myofibroblast Differentiation. BIOLOGY 2013; 2:555-86. [PMID: 24832798 PMCID: PMC3960882 DOI: 10.3390/biology2020555] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/25/2013] [Revised: 03/01/2013] [Accepted: 03/06/2013] [Indexed: 01/06/2023]
Abstract
Myofibroblasts (MFBs) are smooth muscle-like cells that provide contractile force required for tissue repair during wound healing. The leading agonist for MFB differentiation is transforming growth factor β1 (TGFβ1) that induces transcription of genes encoding smooth muscle α-actin (SMαA) and interstitial collagen that are markers for MFB differentiation. TGFβ1 augments activation of Smad transcription factors, pro-survival Akt kinase, and p38 MAP kinase as well as Wingless/int (Wnt) developmental signaling. These actions conspire to activate β-catenin needed for expression of cyclin D, laminin, fibronectin, and metalloproteinases that aid in repairing epithelial cells and their associated basement membranes. Importantly, β-catenin also provides a feed-forward stimulus that amplifies local TGFβ1 autocrine/paracrine signaling causing transition of mesenchymal stromal cells, pericytes, and epithelial cells into contractile MFBs. Complex, mutually interactive mechanisms have evolved that permit several mammalian cell types to activate the SMαA promoter and undergo MFB differentiation. These molecular controls will be reviewed with an emphasis on the dynamic interplay between serum response factor, TGFβ1-activated Smads, Wnt-activated β-catenin, p38/calcium-activated NFAT protein, and the RNA-binding proteins, Purα, Purβ, and YB-1, in governing transcriptional and translational control of the SMαA gene in injury-activated MFBs.
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Affiliation(s)
- Arthur Roger Strauch
- Department of Physiology & Cell Biology and the Ohio State Biochemistry Program, the Dorothy M. Davis Heart & Lung Research Institute, The Ohio State University College of Medicine, Columbus, OH 43210, USA.
| | - Seethalakshmi Hariharan
- Department of Physiology & Cell Biology and the Ohio State Biochemistry Program, the Dorothy M. Davis Heart & Lung Research Institute, The Ohio State University College of Medicine, Columbus, OH 43210, USA.
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Klingberg F, Hinz B, White ES. The myofibroblast matrix: implications for tissue repair and fibrosis. J Pathol 2013; 229:298-309. [PMID: 22996908 DOI: 10.1002/path.4104] [Citation(s) in RCA: 522] [Impact Index Per Article: 47.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2012] [Revised: 09/09/2012] [Accepted: 09/11/2012] [Indexed: 12/12/2022]
Abstract
Myofibroblasts, and the extracellular matrix (ECM) in which they reside, are critical components of wound healing and fibrosis. The ECM, traditionally viewed as the structural elements within which cells reside, is actually a functional tissue whose components possess not only scaffolding characteristics, but also growth factor, mitogenic, and other bioactive properties. Although it has been suggested that tissue fibrosis simply reflects an 'exuberant' wound-healing response, examination of the ECM and the roles of myofibroblasts during fibrogenesis instead suggest that the organism may be attempting to recapitulate developmental programmes designed to regenerate functional tissue. Evidence of this is provided by the temporospatial re-emergence of embryonic ECM proteins by fibroblasts and myofibroblasts that induce cellular programmatic responses intended to produce a functional tissue. In the setting of wound healing (or physiological fibrosis), this occurs in a highly regulated and exquisitely choreographed fashion which results in cessation of haemorrhage, restoration of barrier integrity, and re-establishment of tissue function. However, pathological tissue fibrosis, which oftentimes causes organ dysfunction and significant morbidity or mortality, likely results from dysregulation of normal wound-healing processes or abnormalities of the process itself. This review will focus on the myofibroblast ECM and its role in both physiological and pathological fibrosis, and will discuss the potential for therapeutically targeting ECM proteins for treatment of fibrotic disorders.
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Affiliation(s)
- Franco Klingberg
- Laboratory of Tissue Repair and Regeneration, Matrix Dynamics Group, Faculty of Dentistry, University of Toronto, Toronto, Ontario, M5S 3E2, Canada
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Zeisberg M, Kalluri R. Cellular mechanisms of tissue fibrosis. 1. Common and organ-specific mechanisms associated with tissue fibrosis. Am J Physiol Cell Physiol 2013; 304:C216-25. [PMID: 23255577 PMCID: PMC3566435 DOI: 10.1152/ajpcell.00328.2012] [Citation(s) in RCA: 343] [Impact Index Per Article: 31.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2012] [Accepted: 12/17/2012] [Indexed: 12/20/2022]
Abstract
Fibrosis is a pathological scarring process that leads to destruction of organ architecture and impairment of organ function. Chronic loss of organ function in most organs, including bone marrow, heart, intestine, kidney, liver, lung, and skin, is associated with fibrosis, contributing to an estimated one third of natural deaths worldwide. Effective therapies to prevent or to even reverse existing fibrotic lesions are not yet available in any organ. There is hope that an understanding of common fibrosis pathways will lead to development of antifibrotic therapies that are effective in all of these tissues in the future. Here we review common and organ-specific pathways of tissue fibrosis.
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Affiliation(s)
- Michael Zeisberg
- Department of Nephrology and Rheumatology, Göttingen University Medical Center, Georg August University, Göttingen, Germany.
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119
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Boor P, Floege J. The renal (myo-)fibroblast: a heterogeneous group of cells. Nephrol Dial Transplant 2013; 27:3027-36. [PMID: 22851626 DOI: 10.1093/ndt/gfs296] [Citation(s) in RCA: 71] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Several studies have demonstrated that mesenchymal stem cells have the capacity to reverse acute and chronic kidney injury in different experimental models by paracrine mechanisms. This paracrine action may be accounted for, at least in part, by microvesicles (MVs) released from mesenchymal stem cells, resulting in a horizontal transfer of mRNA, microRNA and proteins. MVs, released as exosomes from the endosomal compartment, or as shedding vesicles from the cell surface, are now recognized as being an integral component of the intercellular microenvironment. By acting as vehicles for information transfer, MVs play a pivotal role in cell-to-cell communication. This exchange of information between the injured cells and stem cells has the potential to be bi-directional. Thus, MVs may either transfer transcripts from injured cells to stem cells, resulting in reprogramming of their phenotype to acquire specific features of the tissue, or conversely, transcripts could be transferred from stem cells to injured cells, restraining tissue injury and inducing cell cycle re-entry of resident cells, leading to tissue self-repair. Upon administration with a therapeutic regimen, MVs mimic the effect of mesenchymal stem cells in various experimental models by inhibiting apoptosis and stimulating cell proliferation. In this review, we discuss whether MVs released from mesenchymal stem cells have the potential to be exploited in novel therapeutic approaches in regenerative medicine to repair damaged tissues, as an alternative to stem cell-based therapy.
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Abstract
TGF-β (transforming growth factor-β) and BMP-7 (bone morphogenetic protein-7), two key members in the TGF-β superfamily, play important but diverse roles in CKDs (chronic kidney diseases). Both TGF-β and BMP-7 share similar downstream Smad signalling pathways, but counter-regulate each other to maintain the balance of their biological activities. During renal injury in CKDs, this balance is significantly altered because TGF-β signalling is up-regulated by inducing TGF-β1 and activating Smad3, whereas BMP-7 and its downstream Smad1/5/8 are down-regulated. In the context of renal fibrosis, Smad3 is pathogenic, whereas Smad2 and Smad7 are renoprotective. However, this counter-balancing mechanism is also altered because TGF-β1 induces Smurf2, a ubiquitin E3-ligase, to target Smad7 as well as Smad2 for degradation. Thus overexpression of renal Smad7 restores the balance of TGF-β/Smad signalling and has therapeutic effect on CKDs. Recent studies also found that Smad3 mediated renal fibrosis by up-regulating miR-21 (where miR represents microRNA) and miR-192, but down-regulating miR-29 and miR-200 families. Therefore restoring miR-29/miR-200 or suppressing miR-21/miR-192 is able to treat progressive renal fibrosis. Furthermore, activation of TGF-β/Smad signalling inhibits renal BMP-7 expression and BMP/Smad signalling. On the other hand, overexpression of renal BMP-7 is capable of inhibiting TGF-β/Smad3 signalling and protects the kidney from TGF-β-mediated renal injury. This counter-regulation not only expands our understanding of the causes of renal injury, but also suggests the therapeutic potential by targeting TGF-β/Smad signalling or restoring BMP-7 in CKDs. Taken together, the current understanding of the distinct roles and mechanisms of TGF-β and BMP-7 in CKDs implies that targeting the TGF-β/Smad pathway or restoring BMP-7 signalling may represent novel and effective therapies for CKDs.
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Van Beneden K, Mannaerts I, Pauwels M, Van den Branden C, van Grunsven LA. HDAC inhibitors in experimental liver and kidney fibrosis. FIBROGENESIS & TISSUE REPAIR 2013; 6:1. [PMID: 23281659 PMCID: PMC3564760 DOI: 10.1186/1755-1536-6-1] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/19/2012] [Accepted: 11/29/2012] [Indexed: 02/08/2023]
Abstract
Histone deacetylase (HDAC) inhibitors have been extensively studied in experimental models of cancer, where their inhibition of deacetylation has been proven to regulate cell survival, proliferation, differentiation and apoptosis. This in turn has led to the use of a variety of HDAC inhibitors in clinical trials. In recent years the applicability of HDAC inhibitors in other areas of disease has been explored, including the treatment of fibrotic disorders. Impaired wound healing involves the continuous deposition and cross-linking of extracellular matrix governed by myofibroblasts leading to diseases such as liver and kidney fibrosis; both diseases have high unmet medical needs which are a burden on health budgets worldwide. We provide an overview of the potential use of HDAC inhibitors against liver and kidney fibrosis using the current understanding of these inhibitors in experimental animal models and in vitro models of fibrosis.
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Affiliation(s)
- Katrien Van Beneden
- Department of Human Anatomy, Liver Cell Biology Lab, Vrije Universiteit Brussel, Brussels, Belgium
| | - Inge Mannaerts
- Department of Cell Biology, Liver Cell Biology Lab, Vrije Universiteit Brussel, Brussels, Belgium
| | - Marina Pauwels
- Department of Human Anatomy, Liver Cell Biology Lab, Vrije Universiteit Brussel, Brussels, Belgium
| | | | - Leo A van Grunsven
- Department of Cell Biology, Liver Cell Biology Lab, Vrije Universiteit Brussel, Brussels, Belgium
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Banerjee B, Musk M, Sutanto EN, Yerkovich ST, Hopkins P, Knight DA, Lindsey-Temple S, Stick SM, Kicic A, Chambers DC. Regional differences in susceptibiity of bronchial epithelium to mesenchymal transition and inhibition by the macrolide antibiotic azithromycin. PLoS One 2012; 7:e52309. [PMID: 23284981 PMCID: PMC3528745 DOI: 10.1371/journal.pone.0052309] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2012] [Accepted: 11/16/2012] [Indexed: 12/11/2022] Open
Abstract
Objective Dysregulated repair following epithelial injury is a key forerunner of disease in many organs, and the acquisition of a mesenchymal phenotype by the injured epithelial cells (epithelial to mesenchymal transition, EMT) may serve as a source of fibrosis. The macrolide antibiotic azithromycin and the DNA synthesis inhibitor mycophenolate are in clinical use but their mechanism of action remains unknown in post-transplant bronchiolitis obliterans syndrome (BOS). Here we determined if regional variation in the EMT response to TGFβ1 underlies the bronchiolocentric fibrosis leading to BOS and whether EMT could be inhibited by azithromycin or mycophenolate. Methods/Results We found that small and large airway epithelial cells from stable lung transplant patients underwent EMT when stimulated with TGFβ1, however mesenchymal protein expression was higher and loss of epithelial protein expression more complete in small airway epithelial cells. This regional difference was not mediated by changes in expression of the TGFβRII or Smad3 activation. Azithromycin potentially inhibited EMT in both small and large airway epithelial cells by inhibiting Smad3 expression, but not activation. Conclusion Collectively, these observations provide a biologic basis for a previously unexplained but widely observed clinical phenomena, and a platform for the development of new approaches to fibrotic diseases.
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Affiliation(s)
- Balarka Banerjee
- School of Paediatrics and Child Health, the University of Western Australia, Nedlands, Western Australia, Australia
- School of Medicine and Pharmacology, the University of Western Australia, Nedlands, Western Australia, Australia
- Western Australia Lung Transplant Program, Royal Perth Hospital, Perth, Western Australia, Australia
| | - Michael Musk
- Western Australia Lung Transplant Program, Royal Perth Hospital, Perth, Western Australia, Australia
| | - Erika N. Sutanto
- Telethon Institute for Child Health Research, Centre for Child Health Research, the University of Western Australia, Subiaco, Western Australia, Australia
| | | | - Peter Hopkins
- School of Medicine, The University of Queensland, Herston, Queensland, Australia
| | - Darryl A. Knight
- University of British Columbia, James Hogg Research Centre for Cardiovascular and Pulmonary Research, Vancouver, British Columbia, Canada
- Department of Anesthesiology, Pharmacology and Therapeutics, University of British Columbia, Vancouver, British Columbia, Canada
| | - Suzanna Lindsey-Temple
- Centre for Asthma and Allergy Research Institute (CAARR) The Lung Institute of Western Australia, Sir Charles Gairdner Hospital, Perth, Western Australia, Australia
| | - Stephen M. Stick
- School of Paediatrics and Child Health, the University of Western Australia, Nedlands, Western Australia, Australia
- Department of Respiratory Medicine, Princess Margaret Hospital for Children, Perth, Western Australia, Australia
- Telethon Institute for Child Health Research, Centre for Child Health Research, the University of Western Australia, Subiaco, Western Australia, Australia
| | - Anthony Kicic
- School of Paediatrics and Child Health, the University of Western Australia, Nedlands, Western Australia, Australia
- Department of Respiratory Medicine, Princess Margaret Hospital for Children, Perth, Western Australia, Australia
- Telethon Institute for Child Health Research, Centre for Child Health Research, the University of Western Australia, Subiaco, Western Australia, Australia
| | - Daniel C. Chambers
- School of Medicine, The University of Queensland, Herston, Queensland, Australia
- Queensland Lung Transplant Service, The Prince Charles Hospital, Brisbane, Queensland, Australia
- * E-mail:
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Wang W, Wang X, Chun J, Vilaysane A, Clark S, French G, Bracey NA, Trpkov K, Bonni S, Duff HJ, Beck PL, Muruve DA. Inflammasome-independent NLRP3 augments TGF-β signaling in kidney epithelium. THE JOURNAL OF IMMUNOLOGY 2012; 190:1239-49. [PMID: 23264657 DOI: 10.4049/jimmunol.1201959] [Citation(s) in RCA: 188] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Tubulointerstitial inflammation and fibrosis are strongly associated with the outcome of chronic kidney disease. We recently demonstrated that the NOD-like receptor, pyrin domain containing-3 (NLRP3) contributes to renal inflammation, injury, and fibrosis following unilateral ureteric obstruction in mice. NLRP3 expression in renal tubular epithelial cells (TECs) was found to be an important component of experimental disease pathogenesis, although the biology of NLRP3 in epithelial cells is unknown. In human and mouse primary renal TECs, NLRP3 expression was increased in response to TGF-β1 stimulation and associated with epithelial-mesenchymal transition (EMT) and the expression of α-smooth muscle actin (αSMA) and matrix metalloproteinase (MMP) 9. TGF-β1-induced EMT and the induction of MMP-9 and αSMA were significantly decreased in mouse Nlrp3(-/-) renal TECs, suggesting a role for Nlrp3 in TGF-β-dependent signaling. Although apoptosis-associated speck-like protein containing a CARD domain(-/-) TECs demonstrated a phenotype similar to that of Nlrp3(-/-) cells in response to TGF-β1, the effect of Nlrp3 on MMP-9 and αSMA expression was inflammasome independent, as IL-1β, IL-18, MyD88, and caspase-1 were dispensable. Smad2 and Smad3 phosphorylation in response to TGF-β1 was attenuated in Nlrp3(-/-) and apoptosis-associated speck-like protein containing a CARD domain(-/-) cells, accounting for the dampened EMT and TGF-β1 responsiveness in these cells. Consistent with these findings, overexpression of NLRP3 in 293T cells resulted in increased Smad3 phosphorylation and activity. Taken together, these data support a novel and direct role for NLRP3 in promoting TGF-β signaling and R-Smad activation in epithelial cells independent of the inflammasome.
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Affiliation(s)
- Wenjie Wang
- Department of Medicine, University of Calgary, Calgary, Alberta T2N 1N4, Canada
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Abstract
Contractile myofibroblasts are responsible for the irreversible alterations of the lung parenchyma that hallmark pulmonary fibrosis. In response to lung injury, a variety of different precursor cells can become activated to develop myofibroblast features, most notably formation of stress fibers and expression of α-smooth muscle actin. Starting as an acute and beneficial repair process, myofibroblast secretion of collagen and contraction frequently becomes excessive and persists. The result is accumulation of stiff scar tissue that obstructs and ultimately destroys lung function. In addition to being a consequence of myofibroblast activities, the stiffened tissue is also a major promoter of the myofibroblast. The mechanical properties of scarred lung and fibrotic foci promote myofibroblast contraction and differentiation. One essential element in this detrimental feed-forward loop is the mechanical activation of the profibrotic growth factor transforming growth factor-β1 from stores in the extracellular matrix. Interfering with myofibroblast contraction and integrin-mediated force transmission to latent transforming growth factor-β1 and matrix proteins are here presented as possible therapeutic strategies to halt fibrosis.
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126
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Häkkinen L, Larjava H, Koivisto L. Granulation tissue formation and remodeling. ACTA ACUST UNITED AC 2012. [DOI: 10.1111/etp.12008] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Park JH, Hwang I, Hwang SH, Han H, Ha H. Human umbilical cord blood-derived mesenchymal stem cells prevent diabetic renal injury through paracrine action. Diabetes Res Clin Pract 2012; 98:465-73. [PMID: 23026513 DOI: 10.1016/j.diabres.2012.09.034] [Citation(s) in RCA: 77] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2012] [Accepted: 09/10/2012] [Indexed: 12/16/2022]
Abstract
AIMS The present study examined renoprotective effect of human umbilical cord blood-derived mesenchymal stem cells (hUCB-MSC) in diabetes. NRK-52E cells were utilized to determine the paracrine effect of hUCB-MSC. METHODS hUCB was harvested with the mother's consent. MSC obtained from the hUCB were injected through the tail vein. Growth arrested and synchronized NRK-52E cells were stimulated with transforming growth factor-β1 (TGF-β1) in the presence of hUCB-MSC conditioned media. RESULTS At 4 weeks after the streptozotocin (STZ) injection, diabetic rats showed significantly increased urinary protein excretion, renal and glomerular hypertrophy, fractional mesangial area, renal expression of TGF-β1 and α-smooth muscle actin, and collagen accumulation but decreased renal E-cadherin and bone morphogenic protein-7 expression, confirming diabetic renal injury. hUCB-MSC effectively prevented diabetic renal injury except renal and glomerular hypertrophy without a significant effect on blood glucose. CM-DiI-labeled hUCB-MSC and immunostaining of PKcs, a human nuclei antigen, confirmed a few engraftment of hUCB-MSC in diabetic kidneys. hUCB-MSC conditioned media inhibited TGF-β1-induced extracellular matrix upregulation and epithelial-to-mesenchymal transition in NRK-52E cells in a concentration-dependent manner. CONCLUSIONS These results demonstrate the renoprotective effect of hUCB-MSC in STZ-induced diabetic rats possibly through secretion of humoral factors and suggest hUCB-MSC as a possible treatment modality for diabetic renal injury.
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Affiliation(s)
- Jong Hee Park
- Department of Bioinspired Science, Division of Life and Pharmaceutical Science, College of Pharmacy, Ewha Womans University, Seoul, Republic of Korea
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Ly DL, Waheed F, Lodyga M, Speight P, Masszi A, Nakano H, Hersom M, Pedersen SF, Szászi K, Kapus A. Hyperosmotic stress regulates the distribution and stability of myocardin-related transcription factor, a key modulator of the cytoskeleton. Am J Physiol Cell Physiol 2012; 304:C115-27. [PMID: 23054059 DOI: 10.1152/ajpcell.00290.2012] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Hyperosmotic stress initiates several adaptive responses, including the remodeling of the cytoskeleton. Besides maintaining structural integrity, the cytoskeleton has emerged as an important regulator of gene transcription. Myocardin-related transcription factor (MRTF), an actin-regulated coactivator of serum response factor, is a major link between the actin skeleton and transcriptional control. We therefore investigated whether MRTF is regulated by hyperosmotic stress. Here we show that hypertonicity induces robust, rapid, and transient translocation of MRTF from the cytosol to the nucleus in kidney tubular cells. We found that the hyperosmolarity-triggered MRTF translocation is mediated by the RhoA/Rho kinase (ROK) pathway. Moreover, the Rho guanine nucleotide exchange factor GEF-H1 is activated by hyperosmotic stress, and it is a key contributor to the ensuing RhoA activation and MRTF translocation, since siRNA-mediated GEF-H1 downregulation suppresses these responses. While the osmotically induced RhoA activation promotes nuclear MRTF accumulation, the concomitant activation of p38 MAP kinase mitigates this effect. Moderate hyperosmotic stress (600 mosM) drives MRTF-dependent transcription through the cis-element CArG box. Silencing or pharmacological inhibition of MRTF prevents the osmotic stimulation of CArG-dependent transcription and renders the cells susceptible to osmotic shock-induced structural damage. Interestingly, strong hyperosmolarity promotes proteasomal degradation of MRTF, concomitant with apoptosis. Thus, MRTF is an osmosensitive and osmoprotective transcription factor, whose intracellular distribution is regulated by the GEF-H1/RhoA/ROK and p38 pathways. However, strong osmotic stress destabilizes MRTF, concomitant with apoptosis, implying that hyperosmotically induced cell death takes precedence over epithelial-myofibroblast transition, a potential consequence of MRTF-mediated phenotypic reprogramming.
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Affiliation(s)
- Donald L Ly
- Keenan Research Centre in the Li Ka Shing Knowledge Institute, St. Michael’s Hospital and Department of Surgery, University of Toronto, Ontario, Canada
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Insel PA, Murray F, Yokoyama U, Romano S, Yun H, Brown L, Snead A, Lu D, Aroonsakool N. cAMP and Epac in the regulation of tissue fibrosis. Br J Pharmacol 2012; 166:447-56. [PMID: 22233238 DOI: 10.1111/j.1476-5381.2012.01847.x] [Citation(s) in RCA: 112] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Fibrosis, the result of excess deposition of extracellular matrix (ECM), in particular collagen, leads to scarring and loss of function in tissues that include the heart, lung, kidney and liver. The second messenger cAMP can inhibit the formation and extent of ECM during this late phase of inflammation, but the mechanisms for these actions of cAMP and of agents that elevate tissue cAMP levels are not well understood. In this article, we review the fibrotic process and focus on two recently recognized aspects of actions of cAMP and its effector Epac (Exchange protein activated by cAMP): (a) blunting of epithelial-mesenchymal transformation (EMT) and (b) down-regulation of Epac expression by profibrotic agents (e.g. TGF-β, angiotensin II), which may promote tissue fibrosis by decreasing Epac-mediated antifibrotic actions. Pharmacological approaches that raise cAMP or blunt the decrease in Epac expression by profibrotic agents may thus be strategies to block or perhaps reverse tissue fibrosis. LINKED ARTICLES This article is part of a themed section on Novel cAMP Signalling Paradigms. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2012.166.issue-2.
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Affiliation(s)
- Paul A Insel
- Departments of Pharmacology Medicine, University of California San Diego, La Jolla, CA 92093, USA.
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130
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Du X, Shimizu A, Masuda Y, Kuwahara N, Arai T, Kataoka M, Uchiyama M, Kaneko T, Akimoto T, Iino Y, Fukuda Y. Involvement of matrix metalloproteinase-2 in the development of renal interstitial fibrosis in mouse obstructive nephropathy. J Transl Med 2012; 92:1149-60. [PMID: 22614125 DOI: 10.1038/labinvest.2012.68] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Renal fibrosis is a common finding in progressive renal diseases. Matrix metalloproteinases (MMPs) are involved in epithelial-to-mesenchymal transition (EMT). We investigated the role of MMP-2 and the effect of inhibition of MMPs on the development of renal fibrosis. Renal fibrosis was induced in MMP-2 wild-type (MMP-2⁺/⁺) mice by unilateral ureteral obstruction (UUO). Renal histopathology, EMT-associated molecules, and activity of MMP-2 and MMP-9 were examined during the development of interstitial fibrosis. UUO-renal fibrosis was also induced in MMP-2 deficient (MMP-2⁻/⁻) and MMP-2⁺/⁺ mice treated with minocycline (inhibitor of MMPs). In MMP-2⁺/⁺ mice, MMP-2 and MMP-9 were expressed in damaged tubules, and their activities increased in a time-dependent manner after UUO. Interstitial fibrosis was noted at day 14, with deposition of types III and I collagens and expression of markers of mesenchymal cells (S100A4, vimentin, α-smooth muscle actin, and heat shock protein-47) in damaged tubular epithelial cells, together with F4/80+ macrophage infiltration. Fibrotic kidneys expressed EMT-associated molecules (ILK, TGF-β1, Smad, Wnt, β-catenin, and Snail). In contrast, the kidneys of MMP-2⁻/⁻ mice and minocycline-treated MMP-2⁺/⁺ mice showed amelioration of renal fibrosis with reduced expression of markers of mesenchymal cells in tubular epithelial cells, inhibition of upregulated EMT-associated molecules, and suppression of macrophage infiltration. The results suggested that MMP-2 have a pathogenic role in renal interstitial fibrosis, possibly through the induction of EMT and macrophage infiltration. Inhibition of MMPs may be beneficial therapeutically in renal fibrosis.
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Affiliation(s)
- Xuanyi Du
- Department of Pathology-Analytic Human Pathology, Nippon Medical School, Tokyo, Japan
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131
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Affiliation(s)
- Hui Yao Lan
- Li Ka Shing Institute of Health Sciences and Department of Medicine & Therapeutics, and CUHK Shenzhen Research Institute; The Chinese University of Hong Kong; Hong Kong; China
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132
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Xiong M, Gong J, Liu Y, Xiang R, Tan X. Loss of vitamin D receptor in chronic kidney disease: a potential mechanism linking inflammation to epithelial-to-mesenchymal transition. Am J Physiol Renal Physiol 2012; 303:F1107-15. [PMID: 22791341 DOI: 10.1152/ajprenal.00151.2012] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Both peritubular inflammation and tubular epithelial-to-mesenchymal transition (EMT) are critical events during the pathogenesis of renal fibrosis. However, the relationship between these two processes is unclear. Here, we investigated the potential role of the vitamin D receptor (VDR) in coupling peritubular inflammation and EMT. In a mouse model of unilateral ureteral obstruction (UUO), loss of VDR was observed as early as 1 day after surgery. In cultured proximal tubular epithelial HK-2 cells, proinflammatory TNF-α inhibited the expression of VDR in a dose- and time-dependant manner. Treatment with TNF-α sensitized HK-2 cells to EMT stimulated by transforming growth factor (TGF)-β1. Ectopic expression of VDR counteracted the synergistic effect of TNF-α and TGF-β1 on EMT. Furthermore, knockdown of VDR using a small interfering RNA strategy mimicked the effect of TNF-α on facilitating EMT. Either TNF-α treatment or a loss of VDR induced β-catenin activation and its nuclear translocation. The VDR ligand calcitriol reversed the VDR loss and inhibited EMT in the mouse UUO model, and late administration of active vitamin D was effective in restoring VDR expression as well, and reduced collagen accumulation and deposition compared with the vehicle control. β-Catenin expression induced by UUO was also significantly inhibited after the late administration of vitamin D. These results indicate that the early loss of VDR in chronic kidney diseases was likely mediated by proinflammatory TNF-α, which renders tubular cells susceptible to EMT. Our data suggest that loss of VDR couples peritubular inflammation and EMT, two key events in renal fibrogenesis.
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Affiliation(s)
- Min Xiong
- Dept. of Pathology, Nankai Univ., Medical School, R116 Medical School Bldg., 94 Weijin Rd., Nankai District, Tianjin, 300071 China.
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Loeffler I, Liebisch M, Wolf G. Collagen VIII influences epithelial phenotypic changes in experimental diabetic nephropathy. Am J Physiol Renal Physiol 2012; 303:F733-45. [PMID: 22759394 DOI: 10.1152/ajprenal.00212.2012] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Epithelial-to-mesenchymal transition (EMT) is an important mechanism of renal tubulo-interstitial fibrosis in diabetic nephropathy (DN). Inducers of EMT, among others, are transforming growth factor-β(1) (TGF-β(1)) as well as extracellular collagens. In renal cells of diabetic mice and in kidneys of patients with DN, the expression of collagen VIII (gene: Col8α1/α2) is enhanced and characteristic features of DN in streptozotocin (STZ)-induced diabetic Col8α1/α2 knockout-(KO) mice are attenuated compared with diabetic wild-type mice. This study aimed to investigate whether collagen type VIII may influence the induction of EMT. DN was induced in wild-type and Col8α1/α2-KO mice using the established and widely accepted low-dose STZ model [treatment for 5 consecutive days (50 mg/kg)]. Healthy and diabetic mice were analyzed for changes in renal function and the expression of EMT-related genes and proteins. Renal morphology, fibrosis, and various EMT markers were studied in kidneys using immunohistological and molecular biological methods. Knockout of Col8α1/α2 attenuated albuminuria, extracellular matrix production, as well as fibrosis. Furthermore, the kidneys of diabetic Col8α1/α2-KO mice showed a marked reduction in interstitial myofibroblasts, and in tubular cells the inhibition of the expression of epithelial markers as well as the expression of typical mesenchymal markers was reduced. The present study demonstrates that in contrast to diabetic wild-type mice EMT-like changes were attenuated in diabetic Col8α1/α2-KO mice, which indicates that either collagen VIII may be one of the major inducers of EMT-like changes in kidneys of diabetic wild-type mice or/possibly the lack of Col8α1/α2 disrupts TGF-β(1)-induced EMT-like changes.
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Affiliation(s)
- Ivonne Loeffler
- Department of Internal Medicine III, University Hospital, University of Jena, Erlanger Allee 101, Jena, Germany
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Abstract
Fibrotic disorders are commonplace, take many forms and can be life-threatening. No better example of this exists than the progressive fibrosis that accompanies all chronic renal disease. Renal fibrosis is a direct consequence of the kidney's limited capacity to regenerate after injury. Renal scarring results in a progressive loss of renal function, ultimately leading to end-stage renal failure and a requirement for dialysis or kidney transplantation. Although it manifests itself histologically as an increase in extracellular matrix, we know that the histological appearance can be caused by a de novo synthesis of matrix (primarily collagen), or a disproportionate loss of renal parenchyma. In both cases the process depends on a resident mesenchymal cell, the so-called myofibroblast, and is independent of disease etiology. Potentially we can ameliorate fibrosis, either indirectly by modifying the environment the kidney functions in, or more directly by interfering with activation and function of myofibroblasts. However, while renal fibrosis shares many features in common with the wound healing response in other organs, we also recognise that the consequences can be highly kidney specific. This review highlights the similarities and differences between this process in the kidney and other organs, and considers the therapeutic implications.
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Affiliation(s)
- Tim D Hewitson
- Department of Nephrology, Royal Melbourne Hospital & Department of Medicine, University of Melbourne, Melbourne, Australia
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135
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Abstract
Pericytes are cells of mesenchymal origin that are intimately involved in the development and stabilization of vascular networks. Novel studies of their role in inflammation have identified that pericytes are not only major contributors to the activated matrix depositing myofibroblast populations seen in progressive renal fibrosis but perhaps even more importantly, the detachment of renal pericytes from the vasculature contributes to the microvasculature rarefaction and subsequent hypoxia associated with chronic kidney disease. In this review, our current understanding of the functioning of renal pericytes will be considered and set in the context of the wider literature that is currently available on this neglected population of cells.
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136
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Abstract
Dietary sodium chloride (salt) has long been considered injurious to the kidney by promoting the development of glomerular and tubulointerstitial fibrosis. Endothelial cells throughout the vasculature and glomeruli respond to increased dietary salt intake with increased production of transforming growth factor-β (TGF-β) and nitric oxide. High-salt intake activates large-conductance, voltage- and calcium-activated potassium (BK(Ca)) channels in endothelial cells. Activation of BK(Ca) channels promotes signaling through proline-rich tyrosine kinase-2, cellular-sarcoma (c-Src), Akt (also known as protein kinase B), and mitogen-activated protein kinase pathways that lead to endothelial production of TGF-β and nitric oxide. TGF-β signaling is broadly accepted as a strong stimulator of renal fibrosis. The classic description of TGF-β signaling pathology in renal disease involves signaling through Smad proteins resulting in extracellular matrix deposition and fibrosis. Active TGF-β1 also causes fibrosis by inducing epithelial-mesenchymal transition and apoptosis. By enhancing TGF-β signaling, increased dietary salt intake leads to progressive renal failure from nephron loss and glomerular and tubulointerstitial fibrosis.
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Affiliation(s)
- Michael B Hovater
- Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, USA
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137
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Abstract
PURPOSE OF REVIEW Tubulointerstitial injury in the kidney is complex, involving a number of independent and overlapping cellular and molecular pathways, with renal interstitial fibrosis and tubular atrophy (IFTA) as the final common pathway. Furthermore, there are multiple ways to assess IFTA. RECENT FINDINGS Cells involved include tubular epithelial cells, fibroblasts, fibrocytes, myofibroblasts, monocyte/macrophages, and mast cells with complex and still incompletely characterized cell-molecular interactions. Molecular mediators involved are numerous and involve pathways such as transforming growth factor (TGF)-β, bone morphogenic protein (BMP), platelet-derived growth factor (PDGF), and hepatocyte growth factor (HGF). Recent genomic approaches have shed insight into some of these cellular and molecular pathways. Pathologic evaluation of IFTA is central in assessing the severity of chronic disease; however, there are a variety of methods used to assess IFTA. Most assessment of IFTA relies on pathologist assessment of special stains such as trichrome, Sirius Red, and collagen III immunohistochemistry. Visual pathologist assessment can be prone to intra and interobserver variability, but some methods employ computerized morphometery, without a clear consensus as to the best method. SUMMARY IFTA results from on orchestration of cell types and molecular pathways. Opinions vary on the optimal qualitative and quantitative assessment of IFTA.
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Affiliation(s)
- Alton B Farris
- Department of Pathology and Laboratory Medicine, Emory University, Atlanta, Georgia 30322, USA.
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138
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The intrinsic prostaglandin E2-EP4 system of the renal tubular epithelium limits the development of tubulointerstitial fibrosis in mice. Kidney Int 2012; 82:158-71. [PMID: 22513820 DOI: 10.1038/ki.2012.115] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Inflammatory responses in the kidney lead to tubulointerstitial fibrosis, a common feature of chronic kidney diseases. Here we examined the role of prostaglandin E(2) (PGE(2)) in the development of tubulointerstitial fibrosis. In the kidneys of wild-type mice, unilateral ureteral obstruction leads to progressive tubulointerstitial fibrosis with macrophage infiltration and myofibroblast proliferation. This was accompanied by an upregulation of COX-2 and PGE(2) receptor subtype EP(4) mRNAs. In the kidneys of EP(4) gene knockout mice, however, obstruction-induced histological alterations were significantly augmented. In contrast, an EP(4)-specific agonist significantly attenuated these alterations in the kidneys of wild-type mice. The mRNAs for macrophage chemokines and profibrotic growth factors were upregulated in the kidneys of wild-type mice after ureteral obstruction. This was significantly augmented in the kidneys of EP(4)-knockout mice and suppressed by the EP(4) agonist but only in the kidneys of wild-type mice. Notably, COX-2 and MCP-1 proteins, as well as EP(4) mRNA, were localized in renal tubular epithelial cells after ureteral obstruction. In cultured renal fibroblasts, another EP(4)-specific agonist significantly inhibited PDGF-induced proliferation and profibrotic connective tissue growth factor production. Hence, an endogenous PGE(2)-EP(4) system in the tubular epithelium limits the development of tubulointerstitial fibrosis by suppressing inflammatory responses.
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139
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Tan RJ, Liu Y. Matrix metalloproteinases in kidney homeostasis and diseases. Am J Physiol Renal Physiol 2012; 302:F1351-61. [PMID: 22492945 DOI: 10.1152/ajprenal.00037.2012] [Citation(s) in RCA: 177] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Matrix metalloproteinases (MMPs) are a family of zinc-dependent endopeptidases that have been increasingly linked to both normal physiology and abnormal pathology in the kidney. Collectively able to degrade all components of the extracellular matrix, MMPs were originally thought to antagonize the development of fibrotic diseases solely through digestion of excessive matrix. However, increasing evidence has shown that MMPs play a wide variety of roles in regulating inflammation, epithelial-mesenchymal transition, cell proliferation, angiogenesis, and apoptosis. We now have robust evidence for MMP dysregulation in a multitude of renal diseases including acute kidney injury, diabetic nephropathy, glomerulonephritis, inherited kidney disease, and chronic allograft nephropathy. The goal of this review is to summarize current findings regarding the role of MMPs in kidney diseases as well as the mechanisms of action of this family of proteases.
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Affiliation(s)
- Roderick J Tan
- Renal-Electrolyte Division, Department of Medicine, University of Pittsburgh School of Medicine, 200 Lothrop St., Pittsburgh, PA 15261, USA
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140
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Current world literature. Curr Opin Pediatr 2012; 24:277-84. [PMID: 22414891 DOI: 10.1097/mop.0b013e328351e459] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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141
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Nasu T, Kinomura M, Tanabe K, Yamasaki H, Htay SL, Saito D, Hinamoto N, Watatani H, Ujike H, Suzuki Y, Sugaya T, Sugiyama H, Sakai Y, Matsumoto K, Maeshima Y, Makino H. Sustained-release prostacyclin analog ONO-1301 ameliorates tubulointerstitial alterations in a mouse obstructive nephropathy model. Am J Physiol Renal Physiol 2012; 302:F1616-29. [PMID: 22419696 DOI: 10.1152/ajprenal.00538.2011] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Tubulointerstitial injuries are crucial histological alterations that predict the deterioration of renal function in chronic kidney disease. ONO-1301, a novel sustained-release prostacyclin analog, accompanied by thromboxane synthase activity, exerts therapeutic effects on experimental pulmonary hypertension, lung fibrosis, cardiomyopathy, and myocardial ischemia, partly associated with the induction of hepatocyte growth factor (HGF). In the present study, we examined the therapeutic efficacies of ONO-1301 on tubulointerstitial alterations induced by unilateral ureteral obstruction (UUO). After inducing unilateral ureteral obstruction in C57/BL6J mice, a single injection of sustained-release ONO-1301 polymerized with poly (D,L-lactic-co-glycolic acid) sustained-release ONO-1301 (SR-ONO) significantly suppressed interstitial fibrosis, accumulation of types I and III collagen, increase in the number of interstitial fibroblast-specific protein-1 (FSP-1)(+) cells, and interstitial infiltration of monocytes/macrophages (F4/80(+)) in the obstructed kidneys (OBK; day 7). Treatment with SR-ONO significantly suppressed the increase of the renal levels of profibrotic factor TGF-β and phosphorylation of Smad2/3, and elevated the renal levels of HGF in the OBK. In cultured mouse proximal tubular epithelial cells (mProx24), ONO-1301 significantly ameliorated the expression of fibroblast-specific protein-1 and α-smooth muscle actin as well as phosphorylation of Smad3 and increased the expression of zonula occludens-1 and E-cadherin in the presence of TGF-β1 as detected by immunoblot and immunocytochemistry, partly dependent on PGI(2) receptor-mediated signaling. Administration of rabbit anti-HGF antibodies, but not the control IgG, partly reversed the suppressive effects of SR-ONO on tubulointerstitial injuries in the OBK. Taken together, our findings suggest the potential therapeutic efficacies of ONO-1301 in suppressing tubulointerstitial alterations partly mediated via inducing HGF, an antifibrotic factor counteracting TGF-β.
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Affiliation(s)
- Tatsuyo Nasu
- Department of Medicine and Clinical Science, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama, Japan
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142
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Jin Y, Ratnam K, Chuang PY, Fan Y, Zhong Y, Dai Y, Mazloom A, Chen EY, D'Agati V, Xiong H, Ross M, Chen N, Ma'ayan A, He JC. A systems approach identifies HIPK2 as a key regulator of kidney fibrosis. Nat Med 2012; 18:580-8. [PMID: 22406746 PMCID: PMC3321097 DOI: 10.1038/nm.2685] [Citation(s) in RCA: 119] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2011] [Accepted: 01/23/2012] [Indexed: 12/19/2022]
Abstract
Kidney fibrosis is a common process that leads to the progression of various types of kidney disease. We used an integrated computational and experimental systems biology approach to identify protein kinases that regulate gene expression changes in the kidneys of human immunodeficiency virus (HIV) transgenic mice (Tg26 mice), which have both tubulointerstitial fibrosis and glomerulosclerosis. We identified homeo-domain interacting protein kinase 2 (HIPK2) as a key regulator of kidney fibrosis. HIPK2 was upregulated in the kidneys of Tg26 mice and in those of patients with various kidney diseases. HIV infection increased the protein concentrations of HIPK2 by promoting oxidative stress, which inhibited the seven in absentia homolog 1 (SIAH1)-mediated proteasomal degradation of HIPK2. HIPK2 induced apoptosis and the expression of epithelial-to-mesenchymal transition markers in kidney epithelial cells by activating the p53, transforming growth factor β (TGF-β)-SMAD family member 3 (Smad3) and Wnt-Notch pathways. Knockout of HIPK2 improved renal function and attenuated proteinuria and kidney fibrosis in Tg26 mice, as well as in other murine models of kidney fibrosis. We therefore conclude that HIPK2 is a potential target for anti-fibrosis therapy.
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Affiliation(s)
- Yuanmeng Jin
- Division of Nephrology, Department of Medicine, Mount Sinai School of Medicine, New York, NY
- Department of Nephrology, Ruijin Hospital, Jiao Tong University School of Medicine, Shanghai, China
| | - Krishna Ratnam
- Division of Nephrology, Department of Medicine, Mount Sinai School of Medicine, New York, NY
| | - Peter Y. Chuang
- Division of Nephrology, Department of Medicine, Mount Sinai School of Medicine, New York, NY
| | - Ying Fan
- Division of Nephrology, Department of Medicine, Mount Sinai School of Medicine, New York, NY
| | - Yifei Zhong
- Division of Nephrology, Department of Medicine, Mount Sinai School of Medicine, New York, NY
| | - Yan Dai
- Division of Nephrology, Department of Medicine, Mount Sinai School of Medicine, New York, NY
| | - Amin Mazloom
- Department of Pharmacology and Systems Therapeutics, Mount Sinai School of Medicine, New York, NY
- Systems Biology Center New York (SBCNY), New York, NY
| | - Edward Y. Chen
- Department of Pharmacology and Systems Therapeutics, Mount Sinai School of Medicine, New York, NY
- Systems Biology Center New York (SBCNY), New York, NY
| | | | - Huabao Xiong
- Immunobiology Center, Mount Sinai School of Medicine, New York, NY
| | - Michael Ross
- Division of Nephrology, Department of Medicine, Mount Sinai School of Medicine, New York, NY
| | - Nan Chen
- Department of Nephrology, Ruijin Hospital, Jiao Tong University School of Medicine, Shanghai, China
| | - Avi Ma'ayan
- Department of Pharmacology and Systems Therapeutics, Mount Sinai School of Medicine, New York, NY
- Systems Biology Center New York (SBCNY), New York, NY
| | - John Cijiang He
- Division of Nephrology, Department of Medicine, Mount Sinai School of Medicine, New York, NY
- Department of Pharmacology and Systems Therapeutics, Mount Sinai School of Medicine, New York, NY
- James J. Peters Veteran Administration Medical Center, New York, NY
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143
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Cardiac Fibrosis in Human Transplanted Hearts Is Mainly Driven by Cells of Intracardiac Origin. J Am Coll Cardiol 2012; 59:1008-16. [DOI: 10.1016/j.jacc.2011.11.036] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/21/2011] [Revised: 11/22/2011] [Accepted: 11/29/2011] [Indexed: 11/21/2022]
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144
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Complex Regulation of the Pericellular Proteolytic Microenvironment during Tumor Progression and Wound Repair: Functional Interactions between the Serine Protease and Matrix Metalloproteinase Cascades. Biochem Res Int 2012; 2012:454368. [PMID: 22454771 PMCID: PMC3290807 DOI: 10.1155/2012/454368] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2011] [Accepted: 11/21/2011] [Indexed: 01/08/2023] Open
Abstract
Spatial and temporal regulation of the pericellular proteolytic environment by local growth factors, such as EGF and TGF-β, initiates a wide repertoire of cellular responses coupled to a plasmin/matrix metalloproteinase (MMP) dependent stromal-remodeling axis. Cell motility and invasion, tumor metastasis, wound healing, and organ fibrosis, for example, represent diverse events controlled by expression of a subset of genes that encode various classes of tissue remodeling proteins. These include members of the serine protease and MMP families that functionally constitute a complex system of interacting protease cascades and titrated by their respective inhibitors. Several structural components of the extracellular matrix are upregulated by TGF-β as are matrix-active proteases (e.g., urokinase (uPA), plasmin, MMP-1, -3, -9, -10, -11, -13, -14). Stringent controls on serine protease/MMP expression and their topographic activity are essential for maintaining tissue homeostasis. Targeting individual elements in this highly interactive network may lead to novel therapeutic approaches for the treatment of cancer, fibrotic diseases, and chronic wounds.
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145
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Ding H, Zhou D, Hao S, Zhou L, He W, Nie J, Hou FF, Liu Y. Sonic hedgehog signaling mediates epithelial-mesenchymal communication and promotes renal fibrosis. J Am Soc Nephrol 2012; 23:801-13. [PMID: 22302193 DOI: 10.1681/asn.2011060614] [Citation(s) in RCA: 155] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Sonic hedgehog (Shh) signaling is a developmental signal cascade that plays an essential role in regulating embryogenesis and tissue homeostasis. Here, we investigated the potential role of Shh signaling in renal interstitial fibrogenesis. Ureteral obstruction induced Shh, predominantly in the renal tubular epithelium of the fibrotic kidneys. Using Gli1(lacZ) knock-in mice, we identified renal interstitial fibroblasts as Shh-responding cells. In cultured renal fibroblasts, recombinant Shh protein activated Gli1 and induced α-smooth muscle actin (α-SMA), desmin, fibronectin, and collagen I expression, suggesting that Shh signaling promotes myofibroblast activation and matrix production. Blockade of Shh signaling with cyclopamine abolished the Shh-mediated induction of Gli1, Snail1, α-SMA, fibronectin, and collagen I. In vivo, the kidneys of Gli1-deficient mice were protected against the development of interstitial fibrosis after obstructive injury. In wild-type mice, cyclopamine did not affect renal Shh expression but did inhibit induction of Gli1, Snail1, and α-SMA. In addition, cyclopamine reduced matrix expression and mitigated fibrotic lesions. These results suggest that tubule-derived Shh mediates epithelial-mesenchymal communication by targeting interstitial fibroblasts after kidney injury. We conclude that Shh/Gli1 signaling plays a critical role in promoting fibroblast activation, production of extracellular matrix, and development of renal interstitial fibrosis.
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Affiliation(s)
- Hong Ding
- Department of Pathology, University of Pittsburgh School of Medicine, PA 15261, USA
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146
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Kimura S, Asaka M, Atsumi H, Imura J, Fujimoto K, Chikazawa Y, Nakagawa M, Okuyama H, Yamaya H, Yokoyama H. Circulating Fibrocytes in Ischemia-Reperfusion Injury and Chronic Renal Allograft Fibrosis. ACTA ACUST UNITED AC 2012; 121:c16-24. [DOI: 10.1159/000341374] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2012] [Accepted: 06/15/2012] [Indexed: 11/19/2022]
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147
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van Meeteren LA, ten Dijke P. Regulation of endothelial cell plasticity by TGF-β. Cell Tissue Res 2012; 347:177-86. [PMID: 21866313 PMCID: PMC3250609 DOI: 10.1007/s00441-011-1222-6] [Citation(s) in RCA: 253] [Impact Index Per Article: 21.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2011] [Accepted: 07/18/2011] [Indexed: 12/25/2022]
Abstract
Recent evidence has demonstrated that endothelial cells can have a remarkable plasticity. By a process called Endothelial-to-Mesenchymal Transition (EndMT) endothelial cells convert to a more mesenchymal cell type that can give rise to cells such as fibroblasts, but also bone cells. EndMT is essential during embryonic development and tissue regeneration. Interestingly, it also plays a role in pathological conditions like fibrosis of organs such as the heart and kidney. In addition, EndMT contributes to the generation of cancer associated fibroblasts that are known to influence the tumor-microenvironment favorable for the tumor cells. EndMT is a form of the more widely known and studied Epithelial-to-Mesenchymal Transition (EMT). Like EMT, EndMT can be induced by transforming growth factor (TGF)-β. Indeed many studies have pointed to the important role of TGF-β receptor/Smad signaling and downstream targets, such as Snail transcriptional repressor in EndMT. By selective targeting of TGF-β receptor signaling pathological EndMT may be inhibited for the therapeutic benefit of patients with cancer and fibrosis.
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Affiliation(s)
- Laurens A van Meeteren
- Department of Molecular Cell Biology and Centre for Biomedical Genetics, Leiden University Medical Center, Postbus 9600, 2300 RC Leiden, The Netherlands.
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148
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Explanting is an ex vivo model of renal epithelial-mesenchymal transition. J Biomed Biotechnol 2011; 2011:212819. [PMID: 22162630 PMCID: PMC3227440 DOI: 10.1155/2011/212819] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2011] [Revised: 09/01/2011] [Accepted: 09/01/2011] [Indexed: 11/23/2022] Open
Abstract
Recognised by their
de novo expression of alpha-smooth muscle actin
(SMA), recruitment of myofibroblasts is key to
the pathogenesis of fibrosis in chronic kidney
disease. Increasingly, we realise that
epithelial-mesenchymal transition (EMT) may be an
important source of these cells. In this study
we describe a novel model of renal EMT. Rat
kidney explants were finely diced on
gelatin-coated Petri dishes and cultured in
serum-supplemented media. Morphology and
immunocytochemistry were used to identify
mesenchymal (vimentin+, α-smooth muscle
actin (SMA)+, desmin+), epithelial
(cytokeratin+), and endothelial (RECA+) cells at
various time points. Cell outgrowths were all
epithelial in origin (cytokeratin+) at day 3. By
day 10, 50 ± 12%
(mean ± SE) of cytokeratin+
cells double-labelled for SMA, indicating EMT.
Lectin staining established a proximal tubule
origin. By day 17, cultures consisted only of
myofibroblasts (SMA+/cytokeratin−). Explanting
is a reproducible ex vivo model
of EMT. The ability to modify this change in
phenotype provides a useful tool to study the
regulation and mechanisms of renal
tubulointerstitial fibrosis.
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149
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Rodvold JJ, Mahadevan NR, Zanetti M. Lipocalin 2 in cancer: when good immunity goes bad. Cancer Lett 2011; 316:132-8. [PMID: 22075378 DOI: 10.1016/j.canlet.2011.11.002] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2011] [Revised: 10/29/2011] [Accepted: 11/01/2011] [Indexed: 10/15/2022]
Abstract
The innate immune molecule Lipocalin 2 (LCN2) was initially shown to combat bacterial infection by binding bacterial siderophores, hence impairing microbial iron sequestration. In recent years, it has become apparent that LCN2 is over-expressed in cancers of diverse histological origin and that it facilitates tumorigenesis by promoting survival, growth, and metastasis. Herein, we discuss emerging evidence that substantiates two functional roles for LCN2 in cancer: promotion of the epithelial-to-mesenchymal transition (EMT) that facilitates an invasive phenotype and metastasis, and sequestration of iron that results in cell survival and tumorigenesis. Further, we present evidence that upregulated LCN2 expression in solid tumors is induced by hypoxia and pro-inflammation, microenvironmental noxae that converge to cause an endoplasmic reticulum (ER) stress response. Taken together, it appears that tumor cells exploit the beneficial innate immune function of LCN2 to support uncontrolled growth. This duplicity in function highlights LCN2 and its upstream driver, the ER stress response, as key targets for cancer therapy.
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Affiliation(s)
- Jeffrey J Rodvold
- The Laboratory of Immunology, Department of Medicine and Moores Cancer Center, University of California, San Diego, La Jolla, CA 92093-0815, United States
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150
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Pallet N. New insights on stress-induced epithelial phenotypic changes. Nephrol Dial Transplant 2011; 27:483-5. [DOI: 10.1093/ndt/gfr611] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
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