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Wright RD, Dimou P, Northey SJ, Beresford MW. Mesangial cells are key contributors to the fibrotic damage seen in the lupus nephritis glomerulus. JOURNAL OF INFLAMMATION-LONDON 2019; 16:22. [PMID: 31807119 PMCID: PMC6857320 DOI: 10.1186/s12950-019-0227-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Accepted: 11/05/2019] [Indexed: 12/21/2022]
Abstract
Background Lupus nephritis (LN) affects up to 80% of juvenile-onset systemic lupus erythematosus patients. Mesangial cells (MCs) comprise a third of the glomerular cells and are key contributors to fibrotic changes within the kidney. This project aims to identify the roles of MCs in an in vitro model of LN. Methods Conditionally immortalised MCs were treated with pro-inflammatory cytokines or with patient sera in an in vitro model of LN and assessed for their roles in inflammation and fibrosis. Results MCs were shown to produce pro-inflammatory cytokines in response to a model of the inflammatory environment in LN. Further the cells expressed increased levels of mRNA for extracellular matrix (ECM) proteins (COL1A1, COL1A2, COL4A1 and LAMB1), matrix metalloproteinase enzymes (MMP9) and tissue inhibitors of matrix metalloproteinases (TIMP1). Treatment of MCs with serum from patients with active LN was able to induce a similar, albeit milder phenotype. Treatment of MCs with cytokines or patient sera was able to induce secretion of TGF-β1, a known inducer of fibrotic changes. Inhibition of TGF-β1 actions through SB-431542 (an activin A receptor type II-like kinase (ALK5) inhibitor) was able to reduce these responses suggesting that the release of TGF-β1 plays a role in these changes. Conclusions MCs contribute to the inflammatory environment in LN by producing cytokines involved in leukocyte recruitment, activation and maturation. Further the cells remodel the ECM via protein deposition and enzymatic degradation. This occurs through the actions of TGF-β1 on its receptor, ALK5. This may represent a potential therapeutic target for treatment of LN-associated fibrosis.
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Affiliation(s)
- Rachael D Wright
- 1Department of Women's and Children's Health, Institute of Translational Medicine, University of Liverpool, member of Liverpool Health Partners, Liverpool, UK.,2Department of Women and Children's Health, Institute in the Park, Alder Hey Children's NHS Foundation Trust, Eaton Road, Liverpool, L12 2AP UK
| | - Paraskevi Dimou
- 1Department of Women's and Children's Health, Institute of Translational Medicine, University of Liverpool, member of Liverpool Health Partners, Liverpool, UK
| | - Sarah J Northey
- 1Department of Women's and Children's Health, Institute of Translational Medicine, University of Liverpool, member of Liverpool Health Partners, Liverpool, UK
| | - Michael W Beresford
- 1Department of Women's and Children's Health, Institute of Translational Medicine, University of Liverpool, member of Liverpool Health Partners, Liverpool, UK.,3Department of Paediatric Rheumatology, Alder Hey Children's NHS Foundation Trust, member of Liverpool Health Partners, Liverpool, UK
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2
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Mao X, Xu Z, Xu X, Zeng M, Zhao Z, Zhang Z, Ding X, Wu H. TGF-β1 inhibits the autophagy of podocytes by activating mTORC1 in IgA nephropathy. Exp Cell Res 2019; 385:111670. [PMID: 31600491 DOI: 10.1016/j.yexcr.2019.111670] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Revised: 09/11/2019] [Accepted: 10/05/2019] [Indexed: 12/21/2022]
Abstract
IgA nephropathy (IgAN) is a mesangial proliferative glomerulonephritis which often shows proteinuria, an indicator for podocyte damage. TGF-β1 has been known to contribute to podocyte injury by inducing apoptosis, cytoskeleton relocation or cytoskeleton loss. And Decorin, a small proteoglycan known to neutralize TGF-β1, was reported to induce autophagy in vascular endothelial cells. However, it remains unknown how TGF-β1 and Decorin can affect podocyte autophagy in mesangial proliferative glomerulonephritis. In this study, we used in vivo and in vitro models to find out the effect of TGF-β1 and Decorin on podocyte autophagy. P-rpS6 and p-ULK1 were detected by Western blot to show the activation of mTORC1 pathway following TGF-β1 treatment. Also, we collected serum from IgAN patients and anti-Thy1.1 nephritis, and quantified TGF-β1 and Decorin using ELISA. Together, we showed that TGF-β1 could activate mTORC1 and inhibit autophagy, while Decorin has precisely the opposite effect. As the mesangial cells (MCs) proliferate, TGF-β1 increases and Decorin decreases in the serum of IgAN and anti-Thy1.1 nephritis. This finding deepened our understanding regarding how MC proliferation could finally result in podocyte dysfunction.
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Affiliation(s)
- Xing Mao
- Department of Pathology, Shanghai Medical College, Fudan University, Shanghai, PR China; Key Laboratory of Molecular Medicine, Chinese Ministry of Education, Shanghai Medical College, Fudan University, Shanghai, PR China
| | - Zhiheng Xu
- Department of Pathology, Shanghai Medical College, Fudan University, Shanghai, PR China
| | - Xialian Xu
- Nephrology Department, Zhongshan Hospital, Fudan University, Shanghai, PR China; Shanghai Institute of Kidneys and Dialysis, Shanghai, PR China; Shanghai Key Laboratory of Kidney and Blood Purification, Shanghai, PR China
| | - Mingyao Zeng
- Department of Pathology, Shanghai Medical College, Fudan University, Shanghai, PR China; Key Laboratory of Molecular Medicine, Chinese Ministry of Education, Shanghai Medical College, Fudan University, Shanghai, PR China
| | - Zhonghua Zhao
- Department of Pathology, Shanghai Medical College, Fudan University, Shanghai, PR China
| | - Zhigang Zhang
- Department of Pathology, Shanghai Medical College, Fudan University, Shanghai, PR China; Shanghai Institute of Kidneys and Dialysis, Shanghai, PR China; Key Laboratory of Molecular Medicine, Chinese Ministry of Education, Shanghai Medical College, Fudan University, Shanghai, PR China
| | - Xiaoqiang Ding
- Nephrology Department, Zhongshan Hospital, Fudan University, Shanghai, PR China; Shanghai Institute of Kidneys and Dialysis, Shanghai, PR China; Shanghai Key Laboratory of Kidney and Blood Purification, Shanghai, PR China.
| | - Huijuan Wu
- Department of Pathology, Shanghai Medical College, Fudan University, Shanghai, PR China; Shanghai Institute of Kidneys and Dialysis, Shanghai, PR China; Key Laboratory of Molecular Medicine, Chinese Ministry of Education, Shanghai Medical College, Fudan University, Shanghai, PR China.
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3
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Taylor EB, Sasser JM, Maeda KJ, Ryan MJ. Expansion of regulatory T cells using low-dose interleukin-2 attenuates hypertension in an experimental model of systemic lupus erythematosus. Am J Physiol Renal Physiol 2019; 317:F1274-F1284. [PMID: 30892934 DOI: 10.1152/ajprenal.00616.2018] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Systemic lupus erythematosus (SLE) is a chronic multisystem autoimmune disorder that is characterized by prevalent hypertension, renal injury, and cardiovascular disease. Numerous studies have reported a low prevalence and/or impaired function of regulatory T (TREG) cells in both patients with SLE and murine models of the disease. Evidence suggests that TREG cell dysfunction in SLE results from a deficiency in IL-2. Recent studies have reported that low-dose IL-2 therapy expands TREG cells in mouse models of SLE, but whether expanding TREG cells protects against hypertension and renal injury during SLE is unclear. To examine this question, female SLE (NZBWF1) and control (NZW) mice were injected with vehicle or recombinant mouse IL-2 three times in 24 h followed by single maintenance doses every 5 days for 4 wk. Treatment with IL-2 effectively expanded TREG cell populations in the peripheral blood, spleen, and kidneys. Circulating levels of anti-dsDNA IgG autoantibodies, a marker of SLE disease activity, were higher in SLE mice compared with control mice but were unaffected by IL-2 treatment. As previously reported by our laboratory, mean arterial pressure, measured in conscious mice by a carotid catheter, was higher in SLE mice than in control mice. Mean arterial pressure was significantly lower in IL-2-treated SLE mice compared with vehicle-treated SLE mice, suggesting that expanding TREG cells using low-dose IL-2 attenuates the development of hypertension. While the mechanism for the protection against hypertension is unclear, it does not appear to be related to the delay of SLE disease progression.
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Affiliation(s)
- Erin B Taylor
- Department of Physiology and Biophysics, University of Mississippi Medical Center, Jackson, Mississippi
| | - Jennifer M Sasser
- Department of Physiology and Biophysics, University of Mississippi Medical Center, Jackson, Mississippi.,Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, Mississippi
| | - Kenji J Maeda
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, Mississippi
| | - Michael J Ryan
- Department of Physiology and Biophysics, University of Mississippi Medical Center, Jackson, Mississippi.,G.V. (Sonny) Montgomery Veterans Affairs Medical Center, Jackson, Mississippi
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4
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Chaudhari S, Li W, Wang Y, Jiang H, Ma Y, Davis ME, Zuckerman JE, Ma R. Store-operated calcium entry suppressed the TGF-β1/Smad3 signaling pathway in glomerular mesangial cells. Am J Physiol Renal Physiol 2017. [PMID: 28637791 DOI: 10.1152/ajprenal.00483.2016] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Our previous study demonstrated that the abundance of extracellular matrix proteins was suppressed by store-operated Ca2+ entry (SOCE) in mesangial cells (MCs). The present study was conducted to investigate the underlying mechanism focused on the transforming growth factor-β1 (TGF-β1)/Smad3 pathway, a critical pathway for ECM expansion in diabetic kidneys. We hypothesized that SOCE suppressed ECM protein expression by inhibiting this pathway in MCs. In cultured human MCs, we observed that TGF-β1 (5 ng/ml for 15 h) significantly increased Smad3 phosphorylation, as evaluated by immunoblot. However, this response was markedly inhibited by thapsigargin (1 µM), a classical activator of store-operated Ca2+ channels. Consistently, both immunocytochemistry and immunoblot showed that TGF-β1 significantly increased nuclear translocation of Smad3, which was prevented by pretreatment with thapsigargin. Importantly, the thapsigargin effect was reversed by lanthanum (La3+; 5 µM) and GSK-7975A (10 µM), both of which are selective blockers of store-operated Ca2+ channels. Furthermore, knockdown of Orai1, the pore-forming subunit of the store-operated Ca2+ channels, significantly augmented TGF-β1-induced Smad3 phosphorylation. Overexpression of Orai1 augmented the inhibitory effect of thapsigargin on TGF-β1-induced phosphorylation of Smad3. In agreement with the data from cultured MCs, in vivo knockdown of Orai1 specific to MCs using a targeted nanoparticle small interfering RNA delivery system resulted in a marked increase in abundance of phosphorylated Smad3 and in nuclear translocation of Smad3 in the glomerulus of mice. Taken together, our results indicate that SOCE in MCs negatively regulates the TGF-β1/Smad3 signaling pathway.
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Affiliation(s)
- Sarika Chaudhari
- Institute for Cardiovascular and Metabolic Diseases, University of North Texas Health Science Center, Fort Worth, Texas
| | - Weizu Li
- Institute for Cardiovascular and Metabolic Diseases, University of North Texas Health Science Center, Fort Worth, Texas.,Department of Pharmacology, Anhui Medical University, Hefei, China
| | - Yanxia Wang
- Institute for Cardiovascular and Metabolic Diseases, University of North Texas Health Science Center, Fort Worth, Texas
| | - Hui Jiang
- Institute for Cardiovascular and Metabolic Diseases, University of North Texas Health Science Center, Fort Worth, Texas.,First Hospital Affiliated to Anhui University of Traditional Chinese Medicine, Hefei, China
| | - Yuhong Ma
- Institute for Cardiovascular and Metabolic Diseases, University of North Texas Health Science Center, Fort Worth, Texas.,Department of Clinical Medicine, Wanna Medical College, Wuhu, Anhui, China; and
| | - Mark E Davis
- Department of Chemical Engineering, California Institute of Technology, Pasadena, California
| | - Jonathan E Zuckerman
- Department of Chemical Engineering, California Institute of Technology, Pasadena, California
| | - Rong Ma
- Institute for Cardiovascular and Metabolic Diseases, University of North Texas Health Science Center, Fort Worth, Texas;
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5
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Legaki E, Gazouli M. Influence of environmental factors in the development of inflammatory bowel diseases. World J Gastrointest Pharmacol Ther 2016; 7:112-125. [PMID: 26855817 PMCID: PMC4734944 DOI: 10.4292/wjgpt.v7.i1.112] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/28/2015] [Revised: 10/20/2015] [Accepted: 12/04/2015] [Indexed: 02/06/2023] Open
Abstract
Idiopathic inflammatory bowel diseases (IBD), Crohn’s disease (CD) and ulcerative colitis (UC), are multifactorial diseases that are manifested after disruption of a genetic predisposed individual and its intestinal microflora through an environmental stimulus. Urbanization and industrialization are associated with IBD. Epidemiological data, clinical observations and family/immigrants studies indicate the significance of environmental influence in the development of IBD. Some environmental factors have a different effect on the subtypes of IBD. Smoking and appendectomy is negatively associated with UC, but they are aggravating factors for CD. A westernized high fat diet, full of refined carbohydrates is strongly associated with the development of IBD, contrary to a high in fruit, vegetables and polyunsaturated fatty acid-3 diet that is protective against these diseases. High intake of nonsteroidal antiinflammatory drug and oral contraceptive pills as well as the inadequacy of vitamin D leads to an increased risk for IBD and a more malignant course of disease. Moreover, other factors such as air pollution, psychological factors, sleep disturbances and exercise influence the development and the course of IBD. Epigenetic mechanism like DNA methylation, histone modification and altered expression of miRNAS could explain the connection between genes and environmental factors in triggering the development of IBD.
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6
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Inhibition of collagen I accumulation reduces glomerulosclerosis by a Hic-5-dependent mechanism in experimental diabetic nephropathy. J Transl Med 2013; 93:553-65. [PMID: 23508044 DOI: 10.1038/labinvest.2013.42] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Glomerulosclerosis of any cause is characterized by loss of functional glomerular cells and deposition of excessive amounts of interstitial collagens including collagen I. We have previously reported that mesangial cell attachment to collagen I leads to upregulation of Hic-5 in vitro, which mediates mesangial cell apoptosis. Furthermore, glomerular Hic-5 expression was increased during the progression of experimental glomerulosclerosis. We hypothesized that reducing collagen I accumulation in glomerulosclerosis would in turn lower Hic-5 expression, reducing mesangial cell apoptosis, and thus maintaining glomerular integrity. We examined archive renal tissue from rats undergoing experimental diabetic glomerulosclerosis, treated with the transglutaminase-2 inhibitor NTU281. Untreated animals exhibited increased glomerular collagen I accumulation, associated with increased glomerular Hic-5 expression, apoptosis, and mesangial myofibroblast transdifferentiation characterized by α-smooth muscle actin (α-SMA) expression. NTU281 treatment reduced glomerular collagen I accumulation, Hic-5 and α-SMA expression, and apoptosis. Proteinurea and serum creatinine levels were significantly reduced in animals with reduced Hic-5 expression. In vitro studies of Hic-5 knockdown or overexpression show that mesangial cell apoptosis and expression of both α-SMA and collagen I are Hic-5 dependent. Together, these data suggest that there exists, in vitro and in vivo, a positive feedback loop whereby increased levels of collagen I lead to increased mesangial Hic-5 expression favoring not only increased apoptosis, but also mesangial myofibroblast transdifferentiation and increased collagen I expression. Prevention of collagen I accumulation interrupts this Hic-5-dependent positive feedback loop, preserving glomerular architecture, cellular phenotype, and function.
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7
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Akkaş BE, Vural GU, Akdemir UÖ, Karabacak Nİ. Demonstration of Adaptive Functional Differences Seen in Kidneys Accompanying a Nonfunctioning/Hypofunctioning Partner, using Camera Based Tc 99m MAG3 Clearance Measurement Technique. Mol Imaging Radionucl Ther 2013; 21:56-62. [PMID: 23486848 PMCID: PMC3590969 DOI: 10.4274/mirt.309] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2012] [Accepted: 04/19/2012] [Indexed: 12/01/2022] Open
Abstract
OBJECTIVE The aim of this study was to demonstrate the functional compensation that occurs in kidneys which accompany a partner with total or partial loss of renal functioning mass, using camera-based Tc 99m MAG3 clearance technique. MATERIAL AND METHODS Eighty five patients (43M, 42F, age: 44.8±12.6, range: 18-77 years) with normal serum creatinine levels and normal (<Grade 1) Tc 99m MAG3 renogram curves were enrolled for this retrospective study. Patients were grouped as having; group 1: solitary normal kidney (unilateral atrophied/agenetic) (n=23), group 2: normal kidney with contralateral hypoplasic/hypofunctioning kidney (split renal function<30%), (n=24), group 3: bilateral normal kidneys (n=38). The measured camera based Tc 99m MAG3 clearances of normal kidneys in each group were compared. RESULTS Total Tc 99m MAG3 clearances (mL/min/1.73m2) were significantly lower in group 1 and group 2 compared to group 3 (281.5±46, 260.5±61.7 and 316.1±84, respectively). Highest isolated Tc 99m MAG3 clearances among normal functioning kidneys were observed in group 1 (281.5±45.6) followed by group 2 (204.4±55) and group 3 (157.5±44). Moderate negative correlation was detected between the Tc99m MAG3 clearances of normal kidneys and contralateral renal function (r=-0.5, p<0.001). CONCLUSION Normal kidneys can compensate for the loss of contralateral kidney function via increasing their clearances, which seems to be dependent on the residual function of their partner. Camera based Tc 99m MAG3 clearance measurement is an objective method to demonstrate compensatory differences in renal function seen between kidneys with contralateral normofunctioning, hypofunctioning and nonfunctioning partner. CONFLICT OF INTEREST None declared.
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Affiliation(s)
- Burcu Esen Akkaş
- Ankara Oncology Research and Training Hospital, Department of Nuclear Medicine, Ankara, Turkey
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8
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Nicousamide blocks the effects of advanced glycation end products on renal cells. Eur J Pharmacol 2012; 674:455-9. [PMID: 21763303 DOI: 10.1016/j.ejphar.2011.06.056] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2010] [Revised: 06/20/2011] [Accepted: 06/27/2011] [Indexed: 12/22/2022]
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9
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Shimizu H, Hori Y, Kaname S, Yamada K, Nishiyama N, Matsumoto S, Miyata K, Oba M, Yamada A, Kataoka K, Fujita T. siRNA-based therapy ameliorates glomerulonephritis. J Am Soc Nephrol 2010; 21:622-33. [PMID: 20203158 DOI: 10.1681/asn.2009030295] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
RNA interference by short interfering RNAs (siRNAs) holds promise as a therapeutic strategy, but use of siRNAs in vivo remains limited. Here, we developed a system to target delivery of siRNAs to glomeruli via poly(ethylene glycol)-poly(l-lysine)-based vehicles. The siRNA/nanocarrier complex was approximately 10 to 20 nm in diameter, a size that would allow it to move across the fenestrated endothelium to access to the mesangium. After intraperitoneal injection of fluorescence-labeled siRNA/nanocarrier complexes, we detected siRNAs in the blood circulation for a prolonged time. Repeated intraperitoneal administration of a mitogen-activated protein kinase 1 (MAPK1) siRNA/nanocarrier complex suppressed glomerular MAPK1 mRNA and protein expression in a mouse model of glomerulonephritis; this improved kidney function, reduced proteinuria, and ameliorated glomerular sclerosis. Furthermore, this therapy reduced the expression of the profibrotic markers TGF-beta1, plasminogen activator inhibitor-1, and fibronectin. In conclusion, we successfully silenced intraglomerular genes with siRNA using nanocarriers. This technique could aid the investigation of molecular mechanisms of renal disease and has potential as a molecular therapy of glomerular diseases.
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Affiliation(s)
- Hideki Shimizu
- Department of Nephrology and Endocrinology, University of Tokyo Graduate School of Medicine, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-8655, Japan
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10
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Freidkin I, Herman M, Tobar A, Chagnac A, Ori Y, Korzets A, Gafter U. Effects of histone deacetylase inhibitors on rat mesangial cells. Am J Physiol Renal Physiol 2009; 298:F426-34. [PMID: 19923417 DOI: 10.1152/ajprenal.00107.2009] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Glomerular mesangial cells (MCs) proliferate and produce extracellular matrix proteins in many progressive renal diseases. Recently, histone deacetylase inhibitors (HDIs) were shown to have antiproliferative and antifibrogenic effects in some in vitro and in vivo models. Using the [(3)H]-thymidine incorporation test, we have found that the HDI trichostatin A (TSA) effectively inhibits MC growth at nontoxic nanomolar concentrations. Similarly, the HDI valproic acid also inhibited MCs proliferation. Cell-cycle analysis indicated an arrest in G(0)/G(1) phase in response to TSA, which was accompanied by elevation in synthesis of the cyclin-dependent kinase inhibitors (CDKIs) p21/Waf1 and p27/Kip1. TSA treatment suppressed alpha-smooth muscle actin, transforming growth factor-beta1, and collagen protein synthesis by MCs and induced myofibroblast-like appearance of proliferating MCs. In the in vivo model of the anti-Thy1.1-induced glomerulonephritis, TSA and valproic acid treatments significantly suppressed proteinuria. Collectively, these data suggest a therapeutic potential for HDIs in the treatment of mesangial proliferative diseases and glomerulosclerosis.
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Affiliation(s)
- Ilya Freidkin
- Department of Nephrology and Hypertension, Hasharon Hospital, Rabin Medical Center, Petah Tikva, Israel
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11
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Effect of vasopressin on type IV collagen production in human mesangial cells. ACTA ACUST UNITED AC 2008; 147:60-6. [DOI: 10.1016/j.regpep.2008.01.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2007] [Revised: 11/15/2007] [Accepted: 01/02/2008] [Indexed: 12/23/2022]
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12
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Abstract
Few controversies in medicine have such a long history as that of whether salt is identifiably dangerous or not dangerous. The most common reported association between excess dietary salt intake and clinical outcome has been in the field of hypertension, but dietary sodium intake mediates effects that go far beyond, and are independent of, extracellular fluid expansion and elevation in blood pressure. For nephrologists, clinical trials that demonstrate no negative outcome of a high salt diet in the general population are thus not particularly assuasive, because patients with chronic kidney disease (CKD) represent an entity that is by no means comparable to the general population. This review takes a look at the challenges associated with salt balance in CKD patients (particularly at K/DOQI stage 5), followed by a summary of current concepts believed to play a part in salt-mediated pathophysiology, and the conclusion, based on the present state of scientific knowledge, that it appears advisable to advocate low dietary salt intake in this patient population.
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13
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Baccora MHA, Cortes P, Hassett C, Taube DW, Yee J. Effects of long-term elevated glucose on collagen formation by mesangial cells. Kidney Int 2007; 72:1216-25. [PMID: 17728702 DOI: 10.1038/sj.ki.5002517] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Glomerulosclerosis is one of the complications of diabetes that occurs after many years of uncontrolled hyperglycemia. Mesangial cells (MCs) exposed to high glucose (HG) for short periods have shown that transforming growth factor-beta (TGF-beta) and activated diacylglycerol-dependent protein kinase C (PKC) mediate increased collagen formation. Our study examined collagen formation by MCs exposed to HG for 8 weeks. Exposure to HG in overnight culture resulted in the activation of all PKC isoforms. In contrast, 8-week exposure to HG resulted in the persistent activation of PKC-delta, did not change PKC-alpha or -beta activity, and decreased PKC-epsilon activity while increasing collagen I and IV gene and protein expression. Collagen IV accumulation was reversed by specific PKC-delta inhibition. Collagen IV gene expression was completely normalized by TGF-beta neutralization; however, this was associated with plasminogen activator inhibitor-1 (PAI-1) overexpression and a modest reduction in collagen protein. Our studies suggest that prolonged exposure to HG results in PKC-delta-driven collagen accumulation by MCs mediated by PAI-1 but independent of TGF-beta.
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Affiliation(s)
- M H A Baccora
- Division of Nephrology, Department of Medicine, Henry Ford Hospital, Detroit, Michigan 48202-2689, USA
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14
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Sellitti DF, Puggina E, Lagranha C, Doi SQ, Pithon-Curi T, Kohn LD, Suzuki K. TGF-beta-like transcriptional effects of thyroglobulin (Tg) in mouse mesangial cells. Endocr J 2007; 54:449-58. [PMID: 17495424 DOI: 10.1507/endocrj.k06-178] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
TGF-beta-like activities of proteins unrelated to the cytokine could mimic its actions in fibrosis and cell proliferation. Thyroglobulin (Tg) has been identified as having a TGF-beta receptor (TGFbetaR)-binding activity and is deposited in the glomerulus in certain immune-complex diseases. The aim of the present study is to determine whether Tg can reproduce the transcriptional activity of TGF-beta1 in the mouse glomerular mesangial cell (MC), and to examine whether such activity is manifested through TGFbetaR. Real-time RT-PCR was employed to examine the effects of TGF-beta1 and bovine Tg on the expression of three genes (TGF-beta1, plasminogen activator inhibitor 1 [PAI-1], and Pax-8) regulated by TGF-beta1 in other cell types. In addition, a pentacosapeptide TGF-beta1 antagonist, beta(1)(25) (41-65) was employed to determine whether the transcriptional activity of Tg was mediated through the TGF-beta binding site on the TGFbetaR. A 6h exposure to TGF-beta1 resulted in increased TGF-beta1 and PAI-1 transcript, and a decrease in Pax-8. Similarly, a 6h exposure to Tg resulted in increases of about 5-fold in TGF-beta1 and PAI-1 mRNA and a decrease of 53% in Pax-8. In comparison with other proteins, Tg had the greatest positive effect on TGF-beta1 transcript levels. beta(1)(25) (41-65) significantly reduced the TGF-beta1-, but not the Tg-induced changes in TGF-beta1, PAI-1 and Pax-8 transcript levels. We conclude from these studies that Tg possesses a TGF-beta-mimetic transcriptional activity in the MC that is not mediated by its binding to TGFbetaR. These results suggest that Tg and other proteins could initiate glomerular injury by reproducing the actions of TGF-beta1 in the mesangial cell.
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Affiliation(s)
- Donald F Sellitti
- Department of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD 20814-4799, USA
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15
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Yamabe H, Shimada M, Kaizuka M, Nakamura M, Kumasaka R, Murakami RI, Fujita T, Nakamura N, Osawa H, Okumura K. Roxithromycin inhibits transforming growth factor-? production by cultured human mesangial cells. Nephrology (Carlton) 2006; 11:524-30. [PMID: 17199791 DOI: 10.1111/j.1440-1797.2006.00695.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Transforming growth factor-beta (TGF-beta) plays an important role in progression of renal injury. However, few materials which inhibit TGF-beta have been known. Roxithromycin (ROX), macrolide antibiotics, is known to have anti-inflammatory, immunomodulatory and tissue reparative effects besides its bacteriostatic activity, although the exact mechanism of its anti-inflammatory and immunomodulatory effects was not defined. We examined the effect of ROX on production of TGF-beta and type IV collagen by cultured human mesangial cells (HMC). METHODS Human mesangial cells were incubated with several concentrations of ROX and TGF-beta and type IV collagen levels in the culture supernatants were measured by enzyme-linked immunoassay. Amount of TGF-beta mRNA was also quantified by using a colourimetric mRNA quantification kit and semiquantitative reverse transcriptase polymerase chain reaction. We also examined the effect of ROX on tyrosine kinase, MAP kinase and NF-kappaB stimulated by thrombin. RESULTS Roxithromycin (0.1-10.0 microg/mL) inhibited TGF-beta production by HMC in a dose- and time-dependent manner without inducing cell injury. ROX (10.0 microg/mL) also inhibited mRNA expression of TGF-beta in HMC. Thrombin (5 U/mL) stimulated TGF-beta production by HMC and ROX significantly inhibited the stimulating effect of thrombin on TGF-beta production. ROX also inhibited the increment of type IV collagen production stimulated by thrombin. ROX (10.0 microg/mL) suppressed the thrombin-induced NF-kappaB activation, although ROX did not inhibit the activation of tyrosine kinase and MAP kinase by thrombin. CONCLUSION Roxithromycin has an inhibitory effect on TGF-beta production by HMC possibly via inhibition of NF-kappaB. ROX may be a potential agent for the treatment of glomerulosclerosis.
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Affiliation(s)
- Hideaki Yamabe
- The Second Department of Internal Medicine, Hirosaki University School of Medicine, Hirosaki, Japan.
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16
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Sinuani I, Averbukh Z, Gitelman I, Rapoport MJ, Sandbank J, Albeck M, Sredni B, Weissgarten J. Mesangial cells initiate compensatory renal tubular hypertrophy via IL-10-induced TGF-β secretion: effect of the immunomodulator AS101 on this process. Am J Physiol Renal Physiol 2006; 291:F384-94. [PMID: 16571592 DOI: 10.1152/ajprenal.00418.2005] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
The present study investigated the role of IL-10 produced by the mesangial cells in postnephrectomy compensatory renal growth and the effect of the immunomodulator AS101 on this process. One hundred forty unilateral nephrectomized and sham-operated male Sprague-Dawley rats were treated by AS101 or PBS before and after surgery. The results show that secretion of IL-10 and TGF-β by mesangial cells isolated from the remaining kidneys was increased significantly, compared with those of control and sham animals. Moreover, TGF-β secretion by mesangial cells was increased after the addition of exogenous recombinant IL-10 and inhibited in the presence of neutralizing anti-IL-10 antibodies. In vivo, compensatory growth of the remaining kidneys was associated with significant increase in IL-10 content in renal tissues and plasma. Immunohistochemical studies show that IL-10 was produced by mesangial cells. Elevated IL-10 levels were followed by the rise in TGF-β content in plasma and renal tissue. AS101 treatment decreased IL-10 and TGF-β expression in plasma and kidney tissues and results in 25% reduction in the fresh and fractional kidney weight and decreased hypertrophy of tubular cells (protein/DNA ratio, morphometric analysis). Taken together, these data demonstrate that TGF-β production by mesangial cells is IL-10 dependent. Mesangial cells are the major source of IL-10 in kidneys. AS101, by inhibiting the activity of IL-10, decreases TGF-β production by mesangial cells, thus limiting compensatory tubular cell hypertrophy.
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Affiliation(s)
- Inna Sinuani
- Nephrology Division, Assaf Harofeh Medical Center, 70300 Zerifin, Israel
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17
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Noh HJ, Kim HC, Lee SS, Kang YN, Chae YM, Park KK. The inhibitory effect of siRNAs on the high glucose-induced overexpression of TGF-beta1 in mesangial cells. J Korean Med Sci 2006; 21:430-5. [PMID: 16778384 PMCID: PMC2729946 DOI: 10.3346/jkms.2006.21.3.430] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Diabetic nephropathy is characterized by an expansion of the glomerular mesangium, caused by mesangial cell proliferation and an excessive accumulation of extracellar matrix (ECM) proteins, which eventually leading to glomerulosclerosis. TGF-beta1 was found to play an important role in the accumulation of ECM in the kidney. In this study, TGF-beta1 RNA interference was used as an effective therapeutic strategy. The inhibitory effect of TGF-beta1 small interfering RNAs (siRNAs) on the high glucose-induced overexpression of TGF-beta1 in rat mesangial ceys (RMCs). A high levels of glucose induces TGF-beta1 mRNA and protein, and TGF-beta1 siRNAs reduce the ability of high glucose to stimulate their expression. We also examined the inhibitory effect of TGF-beta1 siRNAs on the expression of plasminogen activator inhibitor (PAI)-1 and Collagen Type I which are down-regulators of TGF-beta1. The expression of TGF-beta1, PAI-1 and Collagen Type I was increased in RMCs that were stimulated by 30 mM glucose. TGF-beta1 siRNAs reduces high glucose-induced TGF-beta1, PAI-1, and Collagen Type I mRNA and protein expression in a dose-dependent manner. In conclusion, the present study demonstrates that TGF-beta1 siRNAs effectively inhibits TGF-beta1 mRNA and protein expression in RMCs. These suggest that TGF-beta1 siRNAs through RNAi may be a useful tool for developing new therapeutic applications for the treatment of diabetic nephropathy.
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Affiliation(s)
- Hey-Jeong Noh
- Department of Pathology, Keimyung University School of Medicine, Daegu, Korea
| | - Hyun-Chul Kim
- Department of Nephrology, Keimyung University School of Medicine, Daegu, Korea
| | - Sang-Sook Lee
- Department of Pathology, Keimyung University School of Medicine, Daegu, Korea
| | - Yu-Na Kang
- Department of Pathology, Keimyung University School of Medicine, Daegu, Korea
| | - Young-Mi Chae
- Department of Pathology, College of Medicine, Catholic University School of Medicine, Daegu, Korea
| | - Kwan-Kyu Park
- Department of Pathology, College of Medicine, Catholic University School of Medicine, Daegu, Korea
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18
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Lakhe-Reddy S, Khan S, Konieczkowski M, Jarad G, Wu KL, Reichardt LF, Takai Y, Bruggeman LA, Wang B, Sedor JR, Schelling JR. Beta8 integrin binds Rho GDP dissociation inhibitor-1 and activates Rac1 to inhibit mesangial cell myofibroblast differentiation. J Biol Chem 2006; 281:19688-99. [PMID: 16690620 PMCID: PMC2711893 DOI: 10.1074/jbc.m601110200] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Alpha(v)beta8 integrin expression is restricted primarily to kidney, brain, and placenta. Targeted alpha(v) or beta8 deletion is embryonic lethal due to defective placenta and brain angiogenesis, precluding investigation of kidney alpha(v)beta8 function. We find that kidney beta8 is localized to glomerular mesangial cells, and expression is decreased in mouse models of glomerulosclerosis, suggesting that beta8 regulates normal mesangial cell differentiation. To interrogate beta8 signaling pathways, yeast two-hybrid and co-precipitation studies demonstrated beta8 interaction with Rho guanine nucleotide dissociation inhibitor-1 (GDI). Selective beta8 stimulation enhanced beta8-GDI interaction as well as Rac1 (but not RhoA) activation and lamellipodia formation. Mesangial cells from itgb8-/- mice backcrossed to a genetic background that permitted survival, or gdi-/- mice, which develop glomerulosclerosis, demonstrated RhoA (but not Rac1) activity and alpha-smooth muscle actin assembly, which characterizes mesangial cell myofibroblast transformation in renal disease. To determine whether Rac1 directly modulates RhoA-associated myofibroblast differentiation, mesangial cells were transduced with inhibitory Rac peptide fused to human immunodeficiency virus-Tat, resulting in enhanced alpha-smooth muscle actin organization. We conclude that the beta8 cytosolic tail in mesangial cells organizes a signaling complex that culminates in Rac1 activation to mediate wild-type differentiation, whereas decreased beta8 activation shifts mesangial cells toward a RhoA-dependent myofibroblast phenotype.
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Affiliation(s)
- Sujata Lakhe-Reddy
- Department of Medicine, Case Western Reserve University School of Medicine, Rammelkamp Center for Education and Research, MetroHealth Medical Center, Cleveland, Ohio 44109
| | - Shenaz Khan
- Department of Medicine, Case Western Reserve University School of Medicine, Rammelkamp Center for Education and Research, MetroHealth Medical Center, Cleveland, Ohio 44109
| | - Martha Konieczkowski
- Department of Medicine, Case Western Reserve University School of Medicine, Rammelkamp Center for Education and Research, MetroHealth Medical Center, Cleveland, Ohio 44109
| | - George Jarad
- Department of Medicine, Case Western Reserve University School of Medicine, Rammelkamp Center for Education and Research, MetroHealth Medical Center, Cleveland, Ohio 44109
| | - Karen L. Wu
- Department of Medicine, Case Western Reserve University School of Medicine, Rammelkamp Center for Education and Research, MetroHealth Medical Center, Cleveland, Ohio 44109
| | - Louis F. Reichardt
- Departments of Physiology and Biochemistry/Biophysics, University of California, San Francisco and Howard Hughes Medical Institute, San Francisco, California 94143
| | - Yoshimi Takai
- Department of Molecular Biology and Biochemistry, Osaka University Graduate School of Medicine, Osaka 565−0871, Japan
| | - Leslie A. Bruggeman
- Department of Medicine, Case Western Reserve University School of Medicine, Rammelkamp Center for Education and Research, MetroHealth Medical Center, Cleveland, Ohio 44109
| | - Bingcheng Wang
- Department of Medicine, Case Western Reserve University School of Medicine, Rammelkamp Center for Education and Research, MetroHealth Medical Center, Cleveland, Ohio 44109
- Department of Pharmacology, Case Western Reserve University School of Medicine, Rammelkamp Center for Education and Research, MetroHealth Medical Center, Cleveland, Ohio 44109
| | - John R. Sedor
- Department of Medicine, Case Western Reserve University School of Medicine, Rammelkamp Center for Education and Research, MetroHealth Medical Center, Cleveland, Ohio 44109
- Departments of Physiology and Biophysics, Case Western Reserve University School of Medicine, Rammelkamp Center for Education and Research, MetroHealth Medical Center, Cleveland, Ohio 44109
| | - Jeffrey R. Schelling
- Department of Medicine, Case Western Reserve University School of Medicine, Rammelkamp Center for Education and Research, MetroHealth Medical Center, Cleveland, Ohio 44109
- To whom correspondence should be addressed: MetroHealth Medical Center, 2500 MetroHealth Dr., R415, Cleveland, OH. 44109−1998. Tel.: 216−778−4993; E-mail:
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19
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Jeong HS, Park KK, Kim SP, Choi IJ, Lee IK, Kim HC. Effect of antisense TGF-beta1 oligodeoxynucleotides in streptozotocin- induced diabetic rat kidney. J Korean Med Sci 2004; 19:374-83. [PMID: 15201503 PMCID: PMC2816838 DOI: 10.3346/jkms.2004.19.3.374] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Transforming growth factor (TGF)-beta1 is an important fibrogenic factor that is involved in the pathogenesis of diabetic nephropathy. We evaluated the effect of circular antisense TGF-beta1 oligodeoxynucleotides (ODNs) on the TGF-beta1 expression in the rat mesangial cell culture and in streptozotocin (STZ)-induced diabetic rats. Circular antisense TGF-beta1 ODNs were found to be stable in rat serum, significantly decreasing TGF-beta1 mRNA expression compared with linear antisense ODNs in the rat mesangial cell culture. Circular antisense TGF-beta1 ODNs were introduced into the tail vein of normal rats using hemagglutinating virus of Japan (HVJ)-liposome-mediated gene transfer method and were confirmed to be delivered effectively into the kidney, liver, lungs, and spleen. To inhibit the overexpression of TGF-beta1 in diabetic kidneys, we introduced circular antisense TGF-beta1 ODNs into the STZ-induced diabetic rats. On day 13 after circular antisense TGF-beta1 ODNs injection, TGF-beta1 mRNA and protein expression markedly decreased and urinary TGF-beta1 excretion rate also dropped in the circular antisense TGF-beta1 ODNs-treated diabetic rats. These results suggest that circular antisense TGF-beta1 ODNs may be a useful tool for developing new therapeutic application for progressive diabetic nephropathy.
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Affiliation(s)
- Hyo Soon Jeong
- Department of Anatomy, Keimyung University School of Medicine, Daegu, Korea
| | - Kwan Kyu Park
- Department of Pathology, Keimyung University School of Medicine, Daegu, Korea
| | - Sang Pyo Kim
- Department of Pathology, Keimyung University School of Medicine, Daegu, Korea
| | - In Jang Choi
- Department of Anatomy, Keimyung University School of Medicine, Daegu, Korea
| | - In Kyu Lee
- Department of Internal Medicine, Keimyung University School of Medicine, Daegu, Korea
| | - Hyun Chul Kim
- Kidney Institute, Keimyung University School of Medicine, Daegu, Korea
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20
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Abstract
It has been known for decades that increased dietary intake of salt (NaCl) shortens the life span of rats in a dose-dependent fashion. This review focuses specifically on the recently described biological effect and consequences of increased salt ingestion on the endothelium through a mechanism that is independent of blood pressure. Changes in salt intake are recognized by endothelial cells in the vascular tree and glomeruli through a physical process that promotes a series of signaling events involved in transcriptional regulation of genes that include transforming growth factor-beta1 (TGF-beta1) and the endothelial isoform of nitric oxide synthase (NOS3). A balance is struck between TGF-beta1 and NOS3 as salt intake varies and creates a negative feedback loop, because TGF-beta1 increased expression of NOS3 and NO inhibited production of TGF-beta1 in healthy rats. Changes in this feedback system have been observed in salt-sensitive hypertension and appear to impact end-organ damage, particularly the kidney. The data support an important benefit to reduction of salt intake in the setting of chronic kidney disease.
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Affiliation(s)
- Paul W Sanders
- Nephrology Research and Training Center, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294-0007, USA.
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21
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Runyan CE, Schnaper HW, Poncelet AC. Smad3 and PKCdelta mediate TGF-beta1-induced collagen I expression in human mesangial cells. Am J Physiol Renal Physiol 2003; 285:F413-22. [PMID: 12759229 DOI: 10.1152/ajprenal.00082.2003] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Transforming growth factor (TGF)-beta has been associated with fibrogenesis in clinical studies and animal models. We previously showed that Smad3 promotes COL1A2 gene activation by TGF-beta1 in human mesangial cells. In addition to the Smad pathway, it has been suggested that TGF-beta1 could also activate more classical growth factor signaling. Here, we report that protein kinase C (PKC)delta plays a role in TGF-beta1-stimulated collagen I production. In an in vitro kinase assay, TGF-beta1 treatment specifically increased mesangial cell PKCdelta activity in a time-dependent manner. Translocation to the membrane was detected by immunocytochemistry and immunoblot, suggesting activation of PKCdelta by TGF-beta1. Inhibition of PKCdelta by rottlerin decreased basal and TGF-beta1-stimulated collagen I production, mRNA expression, and COL1A2 promoter activity, whereas blockade of conventional PKCs by Gö 6976 had little or no effect. In a Gal4-LUC assay system, inhibition of PKCdelta abolished TGF-beta1-induced transcriptional activity of Gal4-Smad3 and Gal4-Smad4(266-552). Overexpression of Smad3 or Smad3D, in which the three COOH-terminal serine phosphoacceptor residues have been mutated, increased activity of the SBE-LUC construct, containing four DNA binding sites for Smad3 and Smad4. This induction was blocked by PKCdelta inhibition, suggesting that rottlerin decreased Smad3 transcriptional activity independently of COOH-terminal serine phosphorylation. Blockade of PKCdelta abolished ligand-independent and ligand-dependent stimulation of COL1A2 promoter activity by Smad3. These data indicate that PKCdelta is activated by TGF-beta1 in human mesangial cells. TGF-beta1-stimulated PKCdelta activity positively regulates Smad transcriptional activity and is required for COL1A2 gene transcription. Thus cross talk among multiple signaling pathways likely contributes to the pathogenesis of glomerular matrix accumulation.
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22
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Chang JK, Chuang LY, Ho ML, Wang GJ. Effects of nonsteroidal anti-inflammatory drugs on transforming growth factor-beta expression and bioactivity in rat osteoblast-enriched culture. Kaohsiung J Med Sci 2003; 19:278-88. [PMID: 12873036 DOI: 10.1016/s1607-551x(09)70474-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Nonsteroidal anti-inflammatory drugs (NSAIDs) have been reported to suppress bone remodeling in normal and repaired bones. Our previous results indicated that ketorolac and indomethacin suppressed proliferation, stimulated early differentiation, and induced apoptosis in cultured osteoblasts. Transforming growth factor-beta (TGF-beta) has been reported to enhance proliferation, suppress differentiation, and prevent apoptosis in osteoblasts. We proposed that one pathway of NSAID effects on osteoblast function might be through inhibition of the expression and/or bioactivity of TGF-beta in osteoblasts. We tested the effects of ketorolac and indomethacin on the expression of TGF-beta1 mRNA and protein and the bioactivity of TGF-beta in osteoblast-enriched cultures derived from fetal calvaria. The effects of prostaglandin E1 (PGE1) and PGE2 on TGF-beta expression and bioactivity were also examined in order to understand more about the role of prostaglandins in osteoblast function. Simultaneously, we estimated whether these NSAID effects on osteoblasts were prostaglandin-related. The results showed that 24-hour treatments with both PGEs and theoretic therapeutic concentrations of ketorolac and indomethacin had no significant effects on the levels of either transcription or translation of TGF-beta or the post-translational function of TGF-beta in osteoblasts. These results suggest that NSAIDs do not affect osteoblast function through changes in TGF-beta action in osteoblasts.
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Affiliation(s)
- Je-Ken Chang
- Department of Orthopedics, School of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
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23
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Chen Y, Blom IE, Sa S, Goldschmeding R, Abraham DJ, Leask A. CTGF expression in mesangial cells: involvement of SMADs, MAP kinase, and PKC. Kidney Int 2002; 62:1149-59. [PMID: 12234285 DOI: 10.1111/j.1523-1755.2002.kid567.x] [Citation(s) in RCA: 168] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
BACKGROUND The induction of excess matrix in renal fibrosis seems to be mediated, at least in part, by the transforming growth factor-beta (TGF-beta)-mediated induction of connective tissue growth factor (CTGF) in mesangial cells. METHODS By examining CTGF protein and mRNA expression and promoter activity in the presence or absence of TGF-beta or inhibitors, the signaling pathways controlling basal and TGF-beta-induced CTGF expression in mesangial cells were investigated. RESULTS TGF-beta enhances CTGF mRNA and protein expression in mesangial cells. Mutation of a consensus SMAD binding element in the CTGF promoter completely abolished TGF-beta-induced CTGF expression and reduced basal CTGF expression. The previously identified basal control element-1 (BCE-1) site, but not Sp1 contributes to basal CTGF promoter activity. Ras/MEK/ERK, protein kinase C (PKC) and tyrosine kinase activity also contribute to basal and TGF-beta-induced CTGF promoter activity in cultured mesangial cells. CONCLUSIONS The TGF-beta-induction of CTGF in mesangial cells requires SMADs and PKC/ras/MEK/ERK pathways. SMADs are involved in basal CTGF expression, which presumably reflects the fact that mesangial cells express TGF-beta endogenously. TGF-beta also induces CTGF through ras/MEK/ERK. Inhibiting ras/MEK/ERK seems not to reduce phosphorylation (that is, activation) of SMADs, suggesting that SMADs, although necessary, are insufficient for the TGF-beta-stimulation of the CTGF promoter through ras/MEK/ERK. Thus, maximal TGF-beta induction of CTGF requires synergy between SMAD and ras/MEK/ERK signaling.
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Affiliation(s)
- Youjun Chen
- FibroGen, Inc., 225 Gateway Boulevard, South San Francisco, CA 94080, USA
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24
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Tsunoda S, Yamabe H, Osawa H, Kaizuka M, Shirato K, Okumura K. Cultured rat glomerular epithelial cells show gene expression and production of transforming growth factor-beta: expression is enhanced by thrombin. Nephrol Dial Transplant 2001; 16:1776-82. [PMID: 11522858 DOI: 10.1093/ndt/16.9.1776] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Glomerular crescents play an important role in progressive glomerular injury. The lesions consist of epithelial cells, macrophages, and deposits of fibrin and extracellular matrix. Transforming growth factor beta (TGF-beta) contributes to the modulation of cell growth and extracellular matrix synthesis. Thrombin is involved in fibrin formation in crescents. The purpose of this study was to examine whether glomerular epithelial cells (GEC) could produce TGF-beta, and if so, to clarify the role of TGF-beta in GEC proliferation. We also investigated whether thrombin could modulate the production of TGF-beta and extracellular matrix by GEC. METHODS Bioassay using the TGF-beta-dependent mink pulmonary epithelial cell line (CCL-64), immunoblot analysis, and reverse transcriptase polymerase chain reaction (RT-PCR) were used to demonstrate TGF-beta production by rat GEC. TGF-beta gene expression was examined by RT-PCR in GEC incubated with thrombin, and type IV collagen and fibronectin were quantified by enzyme immunoassay in culture supernatants of GEC incubated with thrombin or TGF-beta. RESULTS TGF-beta activity was demonstrated in GEC supernatants by bioassay. Immunoblot analysis of concentrated culture supernatants using anti-TGF-beta antibody revealed a 12.5-kDa protein, which was compatible with TGF-beta. Concentrated GEC supernatants inhibited GEC proliferation as well as porcine TGF-beta. RT-PCR demonstrated TGF-beta gene expression in GEC. Thrombin (0.5-5.0 U/ml) enhanced TGF-beta mRNA expression in a dose-dependent manner. Thrombin (5.0 U/ml) and porcine TGF-beta (5.0 ng/ml) stimulated the production of type IV collagen and fibronectin by GEC. CONCLUSIONS Rat GEC produce TGF-beta in vitro. Thrombin may participate in the progression of glomerulosclerosis in crescentic glomerulonephritis through the stimulation of TGF-beta production by GEC.
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Affiliation(s)
- S Tsunoda
- Second Department of Internal Medicine, Hirosaki University School of Medicine, Zaifu-cho 5, Hirosaki 036-8216, Japan
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25
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Weigert C, Brodbeck K, Häring HU, Gambaro G, Schleicher ED. Low-molecular-weight heparin prevents high glucose- and phorbol ester-induced TGF-beta 1 gene activation. Kidney Int 2001; 60:935-43. [PMID: 11532088 DOI: 10.1046/j.1523-1755.2001.060003935.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND Hyperglycemia-induced overexpression of prosclerotic transforming growth factor-beta 1 (TGF-beta 1) has been implicated in the pathogenesis of diabetic nephropathy. Since previous in vivo studies demonstrated a renoprotective effect of low-molecular-weight (LMW) heparin in experimental animals, and recent in vitro data showed an interaction of this drug with the overactivated TGF-beta 1 cascade in high glucose- and phorbol ester-stimulated mesangial cells, we studied the molecular mechanism of these effects on TGF-beta 1 gene expression. METHODS Mesangial cells were stimulated with 30 mmol/L glucose or with 0.5 micromol/L phorbol ester [phorbol myristate acetate (PMA)] in the absence or presence of LMW heparin. TGF-beta 1 promoter activity was determined in promoter-reporter luciferase assays. The effect of LMW heparin on the binding of nuclear proteins to a regulatory activator protein-1 (AP-1) site, which mediates the high glucose and PMA responsiveness of the TGF-beta 1 promoter, was studied by electrophoretic mobility shift assays. RESULTS The presence of LMW heparin completely prevented TGF-beta 1 gene activation in both high glucose- and PMA-stimulated cells. Preincubation of the cells with LMW heparin and subsequent stimulation of the cells with both stimuli yielded the same result. Furthermore, treatment with LMW heparin prevented the enhanced binding of nuclear proteins to the regulatory AP-1 site, while binding to a Sp1 site was unaffected. Basal promoter activity and basal AP-1 binding also was reduced by LMW heparin. The LMW heparin effect on basal promoter activity was abolished by mutation of the regulatory AP-1 box B and by deletion of this AP-1 binding site. CONCLUSIONS LMW heparin prevents high glucose- and PMA-mediated TGF-beta 1 expression by inhibiting the activation of the TGF-beta 1 promoter and by preventing the enhanced binding of nuclear proteins to the regulatory AP-1 site.
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Affiliation(s)
- C Weigert
- Department of Internal Medicine, Division of Endocrinology, Metabolism and Pathobio-chemistry, University of Tübingen, Tübingen, Germany
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Osada N, Mochida S, Inao M, Mashimo Y, Fujiwara K. Apoptosis in dissociation between DNA synthesis and cellular functions of activated hepatic stellate cells--a study with carbon tetrachloride-induced rat liver injury. Biochem Biophys Res Commun 2001; 282:524-8. [PMID: 11401491 DOI: 10.1006/bbrc.2001.4545] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
It is widely believed that DNA synthesis and expressions of smooth muscle alpha actin and TGF-beta are all together increased in activated hepatic stellate cells both in vitro and in vivo. Our previous reports disclosed that these increases did not always coexist under experimental conditions. Liver necrosis was induced in rats by oral administration of carbon tetrachloride. Hepatic stellate cells were isolated from these rats 2 days later. When these cells were cultured on plastic dishes for 3 days, they showed marked DNA synthesis and smooth muscle alpha actin and TGF-beta mRNA expressions assessed by (3)H-thymidine incorporation and Northern blotting, respectively. In the cells further cultured for 7 days, the DNA synthesis was decreased, whereas both smooth muscle alpha actin and TGF-beta mRNA expressions were increased, compared to the cells cultured for 3 days. The cells cultured for 10 days showed apoptotic nuclei positive for nick-end labeling, and DNA extracted from the cells revealed laddering patterns on agarose gels by electrophoresis. Apoptotic nuclei were also immunohistochemically found in stellate cells in the liver of rats 4 days after the intoxication. We conclude that apoptosis developed in activated hepatic stellate cells both in vitro and in vivo, and this may contribute to the discrepancy between DNA synthesis and cellular functions of the cells.
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Affiliation(s)
- N Osada
- Third Department of Internal Medicine, Saitama Medical School, 38 Morohongo, Moroyama-cho, Iruma-gun, Saitama, 350-0495, Japan
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27
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Abstract
Many studies of chronic renal disease have reported that men have a more rapid progression of renal insufficiency. However, other studies have found no differences between the sexes, and the true effect of sex on chronic renal disease remains a topic of controversy. There is evidence that women with non-diabetic renal diseases experience a slower progression, but in diabetic renal disease, the effect of gender is not yet established. Sex hormones may mediate the effects of gender on chronic renal disease, through alterations in the renin--angiotensin system, reduction in mesangial collagen synthesis, the modification of collagen degradation, and upregulation of nitric oxide synthesis.
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Affiliation(s)
- S L Seliger
- Division of Nephrology, University of Washington Medical Center, Seattle, Washington, USA
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28
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Ways DK, Sheetz MJ. The role of protein kinase C in the development of the complications of diabetes. VITAMINS AND HORMONES 2001; 60:149-93. [PMID: 11037624 DOI: 10.1016/s0083-6729(00)60019-5] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Diabetes mellitus produces a state of chronic hyperglycemia which in turn leads to the development of severe complications including retinopathy, nephropathy, neuropathy, and atherosclerosis. Many different mechanisms have been put forward to attempt to explain how glucose elevations can damage these various organ systems. Protein kinase C activation is one of the sequelae of hyperglycemia and is thought to play a role in the development of diabetic complications. There are multiple mechanisms for its activation in the diabetic state and multiple downstream effects attributable to that activation. The role of protein kinase C activation in the development of the above-mentioned complications of diabetes is discussed in this chapter. In addition, the potential use of isoform-specific inhibitors of protein kinase C for the treatment of diabetic complications is proposed.
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Affiliation(s)
- D K Ways
- Lilly Research Labs, Eli Lilly and Company Indianapolis, Indiana 46285, USA
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29
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Ha H, Yu MR, Lee HB. High glucose-induced PKC activation mediates TGF-beta 1 and fibronectin synthesis by peritoneal mesothelial cells. Kidney Int 2001; 59:463-70. [PMID: 11168928 DOI: 10.1046/j.1523-1755.2001.059002463.x] [Citation(s) in RCA: 128] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
BACKGROUND Progressive peritoneal fibrosis, membrane hyperpermeability, and ultrafiltration failure have been observed in long-term peritoneal dialysis (PD) using glucose as an osmotic agent. High glucose activates protein kinase C (PKC), which is one important signal pathway in the activation of transforming growth factor-beta 1 (TGF-beta 1) and fibronectin (FN). To gain a better understanding of mechanisms involved in peritoneal fibrosis, we examined the effects of high glucose on human peritoneal mesothelial cell (HPMC) TGF-beta 1 and FN mRNA expression and protein synthesis and determined the involvement of PKC in the high glucose-induced HPMC activation. METHODS Synchronized confluent HPMC were incubated with different concentrations of glucose with and without inhibition of PKC. PKC activity and diacylglycerol (DAG) levels were measured. The expression of TGF-beta 1 and FN mRNAs by HPMC was measured by Northern blot analysis. TGF-beta 1 protein was measured by enzyme-linked immunosorbent assay (ELISA) and mink lung epithelial cell growth inhibition assay. FN protein was measured by Western blot analysis and ELISA. RESULTS PKC activity and DAG levels in HPMC cultured under 50 mmol/L (high) glucose increased 2.3- and 2.0-fold, respectively, that of 5.6 mmol/L (control) glucose at 24 hours and this was sustained up to 72 hours. The expression of TGF-beta 1 and FN mRNA by HPMC cultured under high glucose increased 1.6- and 1.7-fold, respectively, that of control values at 24 hours. TGF-beta bioactivity as well as protein content in heat-activated conditioned media from high glucose was significantly higher than that of control values at 24 and 48 hours. FN protein also increased in response to high glucose, as measured by Western blot analysis and ELISA. PKC activator phorbol 12-myristate 13-acetate (PMA) induced 2.2- and 1.4-fold increase in TGF-beta 1 and FN mRNA expression, respectively. Depletion of PKC and calphostin C, a PKC inhibitor, effectively prevented both PMA and high glucose-induced, but not constitutive, expression of TGF-beta 1 and FN. CONCLUSION The present data demonstrate that high glucose up-regulates TGF-beta 1 and FN synthesis by HPMC, and that this high glucose-induced up-regulation is largely mediated by PKC. These results suggest that activation of PKC by high glucose in conventional PD solutions may constitute an important signal for activation of HPMC, leading to progressive accumulation of extracellular matrix and eventual peritoneal fibrosis.
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Affiliation(s)
- H Ha
- Department of Pharmacology, Yonsei University College of Medicine, Seoul, Korea
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Singh LP, Crook ED. Hexosamine regulation of glucose-mediated laminin synthesis in mesangial cells involves protein kinases A and C. Am J Physiol Renal Physiol 2000; 279:F646-54. [PMID: 10997914 DOI: 10.1152/ajprenal.2000.279.4.f646] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Hyperglycemia leads to alterations in mesangial cell function and extracellular matrix (ECM) protein accumulation. These adverse effects of glucose may be mediated by glucose metabolism through the hexosamine biosynthesis pathway (HBP). The HBP converts fructose-6-phosphate to glucosamine-6-phosphate via the rate-limiting enzyme, glutamine:fructose-6-phosphate amidotransferase (GFA). We have investigated the effects of high glucose (HG, 25 mM) and glucosamine (GlcN, 1.5 mM) on the synthesis of the ECM protein laminin in a SV-40-transformed rat kidney mesangial (MES) cell line. The roles of protein kinases C (PKC) and A (PKA) in mediating laminin accumulation were also investigated. Treatment of MES cells with HG or GlcN for 48 h increased laminin levels in cellular extracts more than twofold compared with 5 mM glucose (low glucose; LG). The presence of the GFA inhibitor diazo-oxo-norleucine (DON, 10 microM) blocked HG but not GlcN-induced laminin synthesis. HG resulted in a time-dependent increase in total PKC and PKA activities, 57+/-11.3 (P < 0.01 vs. LG) and 85+/-17.4% (P < 0.01 vs. LG), respectively. GlcN had no effect on the total PKC activity; however, both glucose and glucosamine increased membrane-associated PKC activity by twofold compared with LG. GlcN stimulated total PKA activity by 47+/-8.4% (P < 0.01 vs. LG). Similarly, membrane- associated PKA activity was also increased by HG and GlcN approximately 1.8 and 1.5-fold, respectively. HG and GlcN increased cellular cAMP levels 2.2- and 3. 4-fold, respectively. Pharmacological downregulation of PKC by long-term incubation of MES cells with 0.5 microM phorbol 12-myristate 13-acetate (PMA) or inhibition of PKA activity by 2 microM H-8 blocked the effects of HG and GlcN on laminin synthesis. These results demonstrate that glucose-induced laminin synthesis in MES cells is mediated by flux through the HBP and that this stimulation involves PKC and PKA signaling pathways.
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Affiliation(s)
- L P Singh
- Division of Nephrology, Department of Medicine, University of Mississippi Medical Center, Jackson, Mississippi 39216-4505, USA
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Kang MJ, Ingram A, Ly H, Thai K, Scholey JW. Effects of diabetes and hypertension on glomerular transforming growth factor-beta receptor expression. Kidney Int 2000; 58:1677-85. [PMID: 11012901 DOI: 10.1046/j.1523-1755.2000.00328.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
BACKGROUND Several studies have suggested that transforming growth factor-beta1 (TGF-beta1) is an important determinant of diabetic glomerular injury. TGF-beta1 forms a heteromeric complex with two cellular receptor subtypes, designated TGF-beta RII and TGF-beta RI, but the effects of diabetes mellitus on glomerular TGF-beta receptor expression have not been completely elucidated. We first compared the effect of experimental type I diabetes mellitus and uninephrectomy on glomerular TGF-beta receptor expression in spontaneously hypertensive rats (SHRs), and then sought to determine whether changes in TGF-beta receptor expression were strain specific by studying normotensive Wistar-Kyoto (WKY) rats. METHODS Five groups of male SHRs were studied. The first group received streptozotocin (60 mg/kg IV) and was studied after one week. The second group received streptozotocin and was studied after two weeks. The third group received streptozotocin (60 mg/kg IV) but received insulin to maintain euglycemia. The fourth group of age-matched SHRs served as the control group, while a fifth group of SHRs underwent uninephrectomy. Four groups of male WKY rats were also studied. The first group of WKY rats served as the age-matched control group. The second group of WKY rats received streptozotocin, while a third group of WKY rats underwent uninephrectomy. The fourth group underwent uninephrectomy and received streptozotocin. At each time point, glomeruli were isolated for protein extraction, and the protein was subjected to Western blot analysis of TGF-beta RII and TGF-beta RI expression. RESULTS Basal expression of both TGF-beta receptors per microgram of glomerular protein was similar in normotensive WKY rats and hypertensive SHRs. Hyperglycemia (blood glucose level, 17.8 +/- 2.9 mmol/L) led to an early twofold increase in TGF-beta RII protein expression and a fourfold increase in TGF-beta RI protein expression in the glomeruli of hypertensive diabetic SHRs compared with euglycemic SHRs (blood glucose level, 5.8 +/- 0.8 mmol/L), which was sustained after two weeks. Insulin treatment (blood glucose level, 5. 2 +/- 0.9 mmol/L) normalized both TGF-beta RII and TGF-beta RI expression in the glomeruli of SHRs that received streptozotocin. Glomerular capillary hypertension in the uninephrectomized SHRs led to a twofold increase in glomerular TGF-beta RII protein expression, but did not reproduce the effect of diabetes mellitus on TGF-beta RI expression. In contrast to the findings in SHRs, neither hyperglycemia (blood glucose level, 15.5 +/- 2.1 mmol/L), uninephrectomy, nor hyperglycemia (blood glucose level, 16.8 +/- 3.0 mmol/L) and uninephrectomy altered TGF-beta receptor expression in the glomeruli of normotensive WKY rats. CONCLUSION These studies support the hypothesis that hemodynamic factors and metabolic factors influence glomerular TGF-beta receptor in vivo in the SHRs.
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Affiliation(s)
- M J Kang
- Department of Medicine, University of Toronto, Toronto, Ontario, Canada
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Lang S, Hartner A, Sterzel RB, Schöcklmann HO. Requirement of cyclin D1 in mesangial cell mitogenesis. J Am Soc Nephrol 2000; 11:1398-1408. [PMID: 10906153 DOI: 10.1681/asn.v1181398] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Abstract. Hyperplasia of mesangial cells (MC) is a frequent finding in glomerulonephritis. The control and function of cyclin D1, a regulator of cell cycle progression, in MC proliferation in vivo and in vitro were investigated. In a rat model of mesangioproliferative glomerulonephritis, increases in the number of cyclin D1-positive MC nuclei were prominent on day 5 of the disease, preceding the peak of MC hyperplasia. In growth-arrested rat MC in culture, mitogenic stimulation with serum or platelet-derived growth factor (PDGF) led to rapid increases in cyclin D1 protein expression. Transforming growth factor-beta1 inhibited PDGF induction of cyclin D1 protein at 12 h. In an examination of the subcellular distribution of cyclin D1, it was observed that stimulation of MC with PDGF for 6 h caused translocation of cyclin D1 from the cytoplasm into the nucleus. Coincubation with PDGF and transforming growth factor-beta1 completely inhibited this effect, without altering the cellular cyclin D1 protein abundance at that time point. To test whether reduction of cyclin D1 protein levels was sufficient to inhibit mitogenesis, MC were transfected with antisense oligonucleotides (ODN) complementary to rat cyclin D1 mRNA. Antisense ODN against cyclin D1 reduced the serum- or PDGF-induced protein expression of cyclin D1 to 27 or 10% of control levels, respectively. These inhibitory effects were correlated with diminished cyclin-dependent kinase 4 activity. Antisense ODN against cyclin D1 also decreased the PDGF-induced increase in p21(Waf-1) protein levels. The MC proliferation caused by serum or PDGF was markedly inhibited by antisense ODN against cyclin D1, as measured by [(3)H]thymidine uptake and cell counts. It is concluded that increased cyclin D1 protein expression of MC is required for MC proliferation. Targeting cyclin D1 expression may represent an effective means to inhibit MC proliferation in vitro and in vivo.
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Affiliation(s)
- Stefan Lang
- Medizinische Klinik IV, Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Andrea Hartner
- Medizinische Klinik IV, Universität Erlangen-Nürnberg, Erlangen, Germany
| | - R Bernd Sterzel
- Medizinische Klinik IV, Universität Erlangen-Nürnberg, Erlangen, Germany
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Shuler FD, Georgescu HI, Niyibizi C, Studer RK, Mi Z, Johnstone B, Robbins RD, Evans CH. Increased matrix synthesis following adenoviral transfer of a transforming growth factor beta1 gene into articular chondrocytes. J Orthop Res 2000; 18:585-92. [PMID: 11052495 DOI: 10.1002/jor.1100180411] [Citation(s) in RCA: 85] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Monolayer cultures of lapine articular chondrocytes were transduced with first-generation adenoviral vectors carrying lacZ or transforming growth factor beta1 genes under the transcriptional control of the human cytomegalovirus early promoter. High concentrations of transforming growth factor beta1 were produced by chondrocytes following transfer of the transforming growth factor beta1 gene but not the lacZ gene. Transduced chondrocytes responded to the elevated endogenous production of transforming growth factor beta1 by increasing their synthesis of proteoglycan, collagen, and noncollagenous proteins in a dose-dependent fashion. The increases in collagen synthesis were not accompanied by alterations in the collagen phenotype; type-II collagen remained the predominant collagen. Transforming growth factor beta1 could not, however, rescue the collagen phenotype of cells that had undergone phenotypic modulation as a result of serial passaging. These data demonstrate that chondrocytes can be genetically manipulated to produce and respond to the potentially therapeutic cytokine transforming growth factor beta1. This technology has a number of experimental and therapeutic applications, including those related to the study and treatment of arthritis and cartilage repair.
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Affiliation(s)
- F D Shuler
- Departments of Orthopaedic Surgery, University of Pittsburgh School of Medicine, Pennsylvania, USA
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Hori Y, Yamada K, Hanafusa N, Okuda T, Okada N, Miyata T, Couser WG, Kurokawa K, Fujita T, Nangaku M. Crry, a complement regulatory protein, modulates renal interstitial disease induced by proteinuria. Kidney Int 1999; 56:2096-106. [PMID: 10594785 DOI: 10.1046/j.1523-1755.1999.00765.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
UNLABELLED Crry, a complement regulatory protein, modulates renal interstitial disease induced by proteinuria. BACKGROUND Recent studies have suggested a role for urinary complement components in mediating tubulointerstitial damage, which is known to have a good correlation with progression of chronic renal diseases. Although accumulating evidence suggests that complement regulatory proteins play an important protective role in glomeruli, their role in renal tubules remains unclear. In order to establish the role of a complement regulatory protein, Crry, in renal tubular injury, we employed a molecular biological approach to block the expression of Crry in tubules of animals with proteinuria induced with puromycin aminonucleoside nephritis (PAN). Methods and Results. Two different antisense oligodeoxynucleotides (ODNs) against Crry were designed and applied to cultured rat mesangial cells in vitro in order to establish their efficacy. Antisense ODN treatment resulted in decreased expression of Crry protein associated with increased sensitivity to complement attack in cell lysis assays compared with control ODN treatment or no treatment (44.7, 1.50, and 1.34%, respectively). Antisense ODNs did not affect the expression of Thy1 as a control, confirming the specificity of our ODNs. In vivo, we performed selective right renal artery perfusion to administer antisense ODNs to the kidney and showed prominent uptake of ODNs by proximal tubular cells. Reduced expression of Crry protein was demonstrated in proximal tubular cells in antisense ODNs-treated kidneys. Normal rats treated with the antisense ODNs did not show any pathological changes. However, in PAN, rats with massive proteinuria showed increased deposition of C3 and C5b-9 in tubules in antisense-treated kidneys, and histological assessment revealed more severe tubulointerstitial injury in antisense-treated animals compared with controls. CONCLUSION These results establish a pathogenic role for complement in leading to tubulointerstitial injury during proteinuria and, to our knowledge for the first time, show a protective role of a complement regulatory protein, Crry, in renal interstitial disease.
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MESH Headings
- Animals
- Antigens, Surface
- Antisense Elements (Genetics)/pharmacokinetics
- Cells, Cultured
- Complement C3/analysis
- Complement C3/metabolism
- Complement System Proteins/metabolism
- Fluorescent Antibody Technique
- Glomerular Mesangium/chemistry
- Glomerular Mesangium/cytology
- Kidney Tubules, Proximal/cytology
- Kidney Tubules, Proximal/physiology
- Male
- Nephritis, Interstitial/etiology
- Nephritis, Interstitial/pathology
- Nephrotic Syndrome/complications
- Nephrotic Syndrome/pathology
- Oligonucleotides/pharmacokinetics
- Periodic Acid-Schiff Reaction
- Proteinuria/complications
- Proteinuria/pathology
- Rats
- Rats, Wistar
- Receptors, Cell Surface
- Receptors, Complement/analysis
- Receptors, Complement/genetics
- Renal Artery
- Transfection
- Vimentin/analysis
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Affiliation(s)
- Y Hori
- Department of Internal Medicine, University of Tokyo School of Medicine, Tokyo, Japan
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Lee HS, Kim BC, Hong HK, Kim YS. LDL stimulates collagen mRNA synthesis in mesangial cells through induction of PKC and TGF-beta expression. THE AMERICAN JOURNAL OF PHYSIOLOGY 1999; 277:F369-76. [PMID: 10484520 DOI: 10.1152/ajprenal.1999.277.3.f369] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Abnormal lipid accumulation in glomeruli could be implicated in the pathogenesis of glomerulosclerosis. Low-density lipoprotein (LDL) stimulates collagen mRNA expression in cultured human mesangial cells (HMC). To explore the possible molecular mechanisms by which LDL promotes collagen gene expression, we examined the effects of LDL on protein kinase C (PKC) activity and transforming growth factor-beta (TGF-beta) expression in relation to collagen gene regulation in HMC. LDL (200 microg/ml) induced an acute increase in PKC activity, particularly PKC-alpha and -delta, within 15 min, which decreased to control value at 2 h. LDL stimulated TGF-beta1, and alpha1(I) and alpha1(IV) collagen mRNA expression within 30 min of incubation with HMC, and levels remained elevated until hour 4. LDL induced the secretion of TGF-beta by HMC. This TGF-beta was shown by CCL-64 mink lung cell assay to be, in part, bioactive. The stimulatory effects of LDL on collagen gene regulation in HMC were blocked by the inhibition of PKC using GF-109203X (GFX) or the downregulation of PKC using phorbol myristate acetate. Neutralizing antibody to TGF-beta inhibited the increased collagen mRNA expression by HMC exposed to LDL. The downregulation or inhibition of PKC did not affect the stimulatory effect of LDL on TGF-beta mRNA or protein expression. These results suggest that in HMC, LDL stimulates collagen mRNA expression through the rapid activation of PKC-alpha and -delta and transcriptional upregulation of TGF-beta. Thus PKC and TGF-beta may function as independent key signaling intermediaries in the pathway by which LDL upregulates collagen gene expression in HMC.
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Affiliation(s)
- H S Lee
- Department of Pathology, Seoul National University College of Medicine, Seoul 110-799, Korea.
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Abstract
The balance between local offense factors and defense machinery determines the fate of tissue injury: progression or resolution. In glomerular research, the most interest has been on the offensive side, for example, the roles of leukocytes, platelets, complement, cytokines, eicosanoids, and oxygen radical intermediates. There has been little focus on the defensive side, which is responsible for the attenuation and resolution of disease. The aim of this review is to address possible mechanisms of local defense that may be exerted during glomerular injury. Cytokine inhibitors, proteinase inhibitors, complement regulatory proteins, anti-inflammatory cytokines, anti-inflammatory eicosanoids, antithrombotic molecules, and extracellular matrix proteins can participate in the extracellular and/or cell surface defense. Heat shock proteins, antioxidants, protein phosphatases, and cyclin kinase inhibitors may contribute to the intracellular defense. This article outlines how the glomerulus, when faced with injurious cells or exposed to pathogenic mediators, defends itself via the intrinsic machinery that is brought into play in resident glomerular cells.
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Affiliation(s)
- M Kitamura
- Department of Medicine, University College London Medical School, England, United Kingdom.
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Kihara M, Yabana M, Toya Y, Kobayashi S, Fujita T, Iwamoto T, Ishigami T, Umemura S. Angiotensin II inhibits interleukin-1 beta-induced nitric oxide production in cultured rat mesangial cells. Kidney Int 1999; 55:1277-83. [PMID: 10200991 DOI: 10.1046/j.1523-1755.1999.00377.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND Macrophage-type nitric oxide synthase (NOS-II) is expressed in glomerular mesangial cells in response to inflammatory cytokines. Nitric oxide (NO) has antithrombotic and cytostatic activities in glomerular diseases. Recent studies have suggested that several vasoactive substances and growth factors modulate NO production in a tissue-specific manner. The aim of this study was to examine whether angiotensin II and transforming growth factor-beta (TGF-beta) modulate cytokine-stimulated NO production and NOS-II gene expression in rat glomerular mesangial cells. METHODS Cultured rat mesangial cells were incubated with interleukin-1 beta (IL-1 beta) for 24 hours. The effects of angiotensin II and TGF-beta on stimulated nitrite accumulation and NOS-II mRNA levels were determined. RESULTS Angiotensin II and TGF-beta significantly decreased IL-1 beta-stimulated nitrite accumulation. The angiotensin type 1 receptor antagonist CV11974 prevented angiotensin II-mediated inhibition of NO production. TGF-beta-neutralizing antibody reversed the effect of TGF-beta without affecting angiotensin II-mediated inhibition of NO production. TGF-beta markedly decreased steady-state levels of NOS-II mRNA and the half-life of the message, whereas angiotensin II did not alter these parameters. CONCLUSIONS These results suggest that in mesangial cells, angiotensin II and TGF-beta participate in the inhibitory regulation of cytokine-induced NO production. TGF-beta inhibits NO production by decreasing NOS-II mRNA levels, whereas angiotensin II may regulate NO production at the levels after NOS-II gene expression. An autocrine action of TGF-beta induced by angiotensin II is unlikely to contribute to angiotensin II-mediated inhibition of NO production.
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Affiliation(s)
- M Kihara
- Department of Medicine II, Yokohama City University, Japan
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Gabriel A, Kuddus RH, Rao AS, Gandhi CR. Down-regulation of endothelin receptors by transforming growth factor beta1 in hepatic stellate cells. J Hepatol 1999; 30:440-50. [PMID: 10190727 DOI: 10.1016/s0168-8278(99)80103-2] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
BACKGROUND/AIMS Hepatic endothelin-1 (ET-1) receptor density as well as the levels of both ET-1 and transforming growth factor beta1 (TGF-beta1) increase in liver cirrhosis. Considering their potent contractile (ET-1) and fibrogenic (TGF-beta1) actions on myofibroblastic stellate cells found in the fibrotic/cirrhotic liver, we aimed to investigate the effects of TGF-beta1 on ET-1 receptors and ET-1 synthesis in these cells. METHODS Stellate cells isolated from rat liver by enzymatic digestion were cultured and subjected to TGF-beta1 treatment. Cellular ET-1 receptors and ET-1 released in the medium were determined. RESULTS TGF-beta1 treatment produced time- and dose-dependent decrease in ET-1 binding sites, but did not affect the affinity of the receptors for ET-1. TGF-beta1 also stimulated the release of ET-1 from stellate cells. The extent of TGF-beta1-induced inhibition of [125I]ET-1 binding was much greater for ETB subtype (73+/-18% inhibition), which comprised a major portion (78+/-12%) of the total ET-1 receptors, than for ETA subtype (35+/-11% inhibition). The mRNA expression of the ET-1 receptors also was reduced by TGF-beta1 treatment. TGF-beta1-induced reduction in ET-1 receptor density was coupled to the inhibition of ET-1-stimulated release of [3Hlarachidonic acid from the prelabeled cells. The effects of TGF-beta1 were inhibited by a TGF-beta1 neutralizing monoclonal antibody. CONCLUSIONS These results suggest that the TGF-beta1-induced decrease in ET-1 receptor density may be an important mechanism in limiting the pathologic actions of ET-1 on stellate cells in chronic liver disease.
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Affiliation(s)
- A Gabriel
- Thomas E. Starzl Transplantation Institute, University of Pittsburgh, PA 15213, USA
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Oh JH, Ha H, Yu MR, Lee HB. Sequential effects of high glucose on mesangial cell transforming growth factor-beta 1 and fibronectin synthesis. Kidney Int 1998; 54:1872-8. [PMID: 9853252 DOI: 10.1046/j.1523-1755.1998.00193.x] [Citation(s) in RCA: 106] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND Transforming growth factor (TGF)-beta is recognized as the final common mediator of the principal lesions of diabetic nephropathy such as renal hypertrophy and mesangial expansion. To gain better understanding of the temporal relationships between high glucose (HG) and mesangial cell (MC) TGF-beta 1 synthesis and between TGF-beta 1 and extracellular matrix (ECM) synthesis, the present study examined early and sequential effects of HG on TGF-beta 1 and fibronectin (FN) mRNA expression and protein synthesis. METHODS Confluent primary rat MC was stimulated with 5.6 (control) or 30 (high) mM glucose after synchronizing the growth by incubation with serum-free media for 48 hours. RESULTS Mesangial cell TGF-beta 1 mRNA expression increased significantly in six hours and continued to increase until 48 hours in response to HG. The level of TGF-beta 1 mRNA was 1.5-fold higher than that of control glucose at six hours and 1.8-fold at 48 hours. TGF-beta activity in heat-activated conditioned media under HG increased 1.5- and 1.6-fold at 24 and 48 hours, respectively, compared to control glucose. FN mRNA increased significantly at 24 and 48 hours and 1.4-fold that of control glucose at both time points. FN protein also increased 1.5-fold that of control glucose at 48 hours. Anti-TGF-beta antibody completely abolished HG-induced FN synthesis. CONCLUSIONS The present finding demonstrate that HG stimulates TGF-beta 1 very early and prior to FN production and that HG-induced FN production is mediated by TGF-beta. This finding is consistent with the view that TGF-beta mediates increased ECM accumulation by MC under high glucose conditions.
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Affiliation(s)
- J H Oh
- Hyonam Kidney Laboratory, Soon Chun Hyang University, Seoul, Korea
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40
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Kasho M, Sakai M, Sasahara T, Anami Y, Matsumura T, Takemura T, Matsuda H, Kobori S, Shichiri M. Serotonin enhances the production of type IV collagen by human mesangial cells. Kidney Int 1998; 54:1083-92. [PMID: 9767524 DOI: 10.1046/j.1523-1755.1998.00114.x] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND The plasma concentration of 5-hydroxytryptamine (5-HT) in diabetic patients is higher than that in normal subjects. Since recent reports have demonstrated the presence of 5-HT2A receptor in glomerular mesangial cells, it is possible that 5-HT may be involved in the development of diabetic nephropathy through the 5-HT2A receptor in mesangial cells. Because expansion of the glomerular mesangial lesion is a characteristic feature of diabetic nephropathy, we examined the effect of 5-HT on the production of type IV collagen by human mesangial cells. METHODS Human mesangial cells were incubated with 5-HT with or without 5-HT receptor antagonists, protein kinase C (PKC) inhibitor or transforming growth factor-beta (TGF-beta) antibody. Type IV collagen mRNA and protein concentration in medium were measured by Northern blot analysis and enzyme-linked immunosorbent assay (ELISA), respectively. TGF-beta mRNA and bioactivity in the medium were measured by Northern blot analysis and bioassay using mink lung epithelial cells, respectively. RESULTS 5-HT stimulated the production of type IV collagen by human mesangial cells, which was inhibited by ketanserin and sarpogrelate hydrochloride, 5-HT2A receptor antagonists, but not by ondansetron, a 5-HT3 receptor antagonist. 5-HT increased the bioactivities of both active and total TGF-beta. However, the 5-HT-enhanced production of type IV collagen was completely inhibited by an anti-TGF-beta antibody. Furthermore, a PKC inhibitor, calphostin C, inhibited the 5-HT-induced increase in type IV collagen secretion, and the activity of membrane PKC was increased by 5-HT. Phorbol ester activated type IV collagen production as well as active and total TGF-beta. Calphostin C completely inhibited the 5-HT-enhanced activity of active TGF-beta, but did not inhibit exogenous TGF-beta-induced increase in type IV collagen secretion. CONCLUSIONS Our results suggest that 5-HT-enhanced production of type IV collagen by human mesangial cells is mediated by activation of PKC and subsequent increase in active TGF-beta activity.
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Affiliation(s)
- M Kasho
- Department of Metabolic Medicine, Kumamoto University School of Medicine, Honjo, Japan
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41
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Ikeda H, Nagoshi S, Ohno A, Yanase M, Maekawa H, Fujiwara K. Activated rat stellate cells express c-met and respond to hepatocyte growth factor to enhance transforming growth factor beta1 expression and DNA synthesis. Biochem Biophys Res Commun 1998; 250:769-75. [PMID: 9784421 DOI: 10.1006/bbrc.1998.9387] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Hepatocyte growth factor (HGF) decreases transforming growth factor beta1 (TGFbeta1) levels in the liver and attenuates hepatic fibrosis caused by dimethylnitrosamine in rats. In the liver, HGF is presumed to act predominantly on parenchymal cells, and TGFbeta1 is produced mainly by mesenchymal cells. In hepatic fibrosis, stellate cells play a central role with undergoing activation, which also occurs when the cells are cultured on plastic. Thus, we wondered if HGF could act directly on stellate cells. c-Met was detected in rat stellate cells activated by culture for 10 days, but not in the cells cultured for 3 days. Specific binding of HGF to the activated cells was determined, and Scatchard analysis indicated an apparent Kd of 1.5 nM. c-Met mRNA was detected in freshly isolated stellate cells from rats treated with carbon tetrachloride for 8 weeks, but not in those cells from normal rats. These results indicate that stellate cells express c-met when activated in vitro and in vivo. HGF enhanced TGFbeta1 production and DNA synthesis in the activated cells.
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Affiliation(s)
- H Ikeda
- First Department of Internal Medicine, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
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Abstract
The treatment of the patient with diabetes, with or without hypertension, is complex and challenging. Hyperglycemic treatment should ideally not only control blood glucose, but also prevent the chronic complications and associated metabolic derangements that can lead to increased morbidity and mortality. Hypertensive treatment should not only decrease blood pressure, but also reduce the risk of macrovascular and microvascular disease. The use of antihypertensive agents that improve insulin resistance, dyslipidemia, glycemic control, and nephropathy is preferred whenever possible. The real key to success in the care of the hypertensive diabetic patient is adequate screening and appropriate, early treatment. Currently, there is ample evidence to support the use of intensive management with the goal of near-normalization of blood glucose levels in most patients with diabetes. Similarly, aggressive treatment of hypertension is the current standard. Accomplishing these goals helps to prevent the development of chronic diabetic complications, including nephropathy. ESRD need not be the inevitable outcome for individuals with early diabetic nephropathy. Interventions currently available that are targeted at the known modifiable risk factors underlying the development and progression of diabetic nephropathy offer the best hope for reducing the incidence and severity of this complication. Prevention of the complications of diabetes, including nephropathy, must be the goal for the future on behalf of all those who now have diabetes.
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Affiliation(s)
- J B Marks
- Department of Medicine, University of Miami School of Medicine, Florida, USA
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43
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Yagi M, Yamamoto T, Kato S, Nagano N, Kihara I. Long-term observation of glomerulonephritis induced by multiple injections with anti-Thy-1 antibody in rats. Pathol Int 1998; 48:491-8. [PMID: 9701010 DOI: 10.1111/j.1440-1827.1998.tb03939.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Multiple injections with a mouse monoclonal anti-rat Thy-1 antibody (five times, at weekly intervals) induced marked glomerular sclerotic lesions which are characterized by adhesion of glomerular capillaries to Bowman's capsule and persistent proteinuria in rats. Abnormal production of type I collagen and increased accumulation of type IV collagen and fibronectin were observed in these glomeruli. The glomerular expression of mRNA for these matrix components and transforming growth factor-beta1 (TGF-beta1) were markedly increased at 4 days after the last injections with anti-Thy-1 antibody, but decreased to below the levels of control rats at 5 weeks. This may be down-regulation of mRNA in mesangial cells. The glomerular sclerotic lesions were not progressive but the process of glomerular healing seemed to be retarded. The proteinuria and the glomerular adhesion were irreversible.
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Affiliation(s)
- M Yagi
- Pharmaceutical Research Laboratory, Kirin Brewery Co., Ltd, Takasaki, Gunma, Japan.
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44
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Kallincos NC, Pollard AN, Couper JJ. Evidence for a functional hepatocyte growth factor receptor in human mesangial cells. REGULATORY PEPTIDES 1998; 74:137-42. [PMID: 9712174 DOI: 10.1016/s0167-0115(98)00034-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
In this study we have investigated both the expression of c-met in cultured human mesangial cells and the proliferative effect of HGF on these cells. RNAse protection analysis using a c-met riboprobe showed c-met to be expressed and further that this expression was unaffected by the glucose concentration or osmolality of the media. Immunofluorescence studies performed using anti-HGF or anti-c-met antibodies clearly showed that both proteins are localised to human mesangial cells. Proliferation of human mesangial cells after 24-h treatment with HGF was also examined. HGF 10 ng/ml and 100 ng/ml stimulated 3-H-Thymidine incorporation 1.35-fold (P = 0.001) and 1.6-fold (P<0.00001) respectively in cells made quiescent for 24 h. A similar dose-dependent stimulation of proliferation was observed in cells made quiescent for 48 h. Finally, using RNAse protection analysis we have shown that HGF (10 ng/ml, 100 ng/ml) induces the expression of c-met in these cells in a dose-dependent manner. Together these results indicate for the first time a potential autocrine role for HGF in the human mesangium.
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Affiliation(s)
- N C Kallincos
- Department of Endocrinology, Women's and Children's Hospital, Adelaide, S.A. Australia.
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45
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Sugiura T, Yamauchi A, Kitamura H, Matusoka Y, Horio M, Imai E, Hori M. Effects of hypertonic stress on transforming growth factor-beta activity in normal rat kidney cells. Kidney Int 1998; 53:1654-60. [PMID: 9607197 DOI: 10.1046/j.1523-1755.1998.00903.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Hypertonicity is known to modulate the expression of some genes and the action of several cytokines. We evaluated whether hypertonicity would increase the expression and/or activity of transforming growth factor-beta (TGF-beta) in normal rat kidney (NRK) cells. The bioassay for TGF-beta showed that mature TGF-beta activity was significantly increased when the cells were cultured in a hypertonic medium (500 mOsm/kg). Comparing to the isotonic medium, hypertonicity accelerated the increase in TGF-beta activity during the initial 24 hours after changing the medium. The activity was increased as the medium osmolality increased from 300 to 500 mOsm/kg. Raffinose was found to be the most effective in increasing TGF-beta activity. NaCl, glucose, and mannitol also increased TGF-beta activity. In contrast, total TGF-beta (mature and latent) activity and TGF-beta mRNA abundance did not change significantly, suggesting that hypertonicity activated TGF-beta without affecting the synthesis of TGF-beta. To determine whether collagen synthesis was increased by hypertonicity, we examined [3H] proline incorporation into NRK cells cultured in hypertonic medium. Proline incorporation increased in an osmolality-dependent manner. Raffinose was also the most effective solute at increasing the proline incorporation. Furthermore, anti-TGF-beta antibody prevented the increase in proline incorporation induced by hypertonicity. These results suggest that hypertonicity promotes the processing of latent TGF-beta to the biologically active form, resulting in the stimulation of collagen synthesis in NRK cells.
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Affiliation(s)
- T Sugiura
- First Department of Medicine, Osaka University School of Medicine, Japan
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46
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Hori Y, Katoh T, Hirakata M, Joki N, Kaname S, Fukagawa M, Okuda T, Ohashi H, Fujita T, Miyazono K, Kurokawa K. Anti-latent TGF-beta binding protein-1 antibody or synthetic oligopeptides inhibit extracellular matrix expression induced by stretch in cultured rat mesangial cells. Kidney Int 1998; 53:1616-25. [PMID: 9607192 DOI: 10.1046/j.1523-1755.1998.00908.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Transforming growth factor-beta (TGF-beta) is usually secreted as a large latent complex associated with latent TGF-beta binding protein-1 (LTBP-1), which is known to bind to extracellular matrix (ECM) components. Although the LTBP-ECM interaction has been suggested to play a role in the activation and biological action of TGF-beta, the precise mechanism is still unclear. In glomerular hypertension mesangial cells are believed to perceive the increased cyclic strain and we have recently reported that cyclic mechanical stretch in vitro enhances the expression of ECM components via an autocrine/paracrine secretion of TGF-beta in cultured rat mesangial cells. Therefore, in this study we examined the role of LTBP-1 in the stretch-induced, TGF-beta-mediated ECM expression. Mesangial cells expressed mRNA for short and long forms of LTBP-1 (LTBP-1S and LTBP-1L, respectively). Mesangial cells were subjected to cyclic stretch to provide a maximal elongation of 20% at a rate of 60 cycles/min for 24 to 36 hours in the presence of polyclonal antibody raised against human LTBP-1 or synthetic oligopeptides corresponding to the N-terminal portions of human LTBP-1, which may work as competitive inhibitors against the LTBP-ECM association. Both anti-LTBP-1 antibody (Ab39) and synthetic oligopeptides inhibited the stretch-induced mRNA expression of type I collagen and fibronectin in a dose-dependent manner, but the inhibition by Ab39 or the oligopeptides was recovered by adding recombinant TGF-beta. Ab39 or the oligopeptides did not change the effect of exogenously added TGF-beta, such as growth-inhibition in mink lung epithelial cells. These results suggest that mesangial cells secrete TGF-beta as a large latent complex, and the LTBP-ECM interaction may be a pivotal step in TGF-beta action and ECM accumulation, providing a new therapeutic strategy against progression of glomerulosclerosis and other fibrotic diseases.
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Affiliation(s)
- Y Hori
- 1st Department of Internal Medicine, University of Tokyo School of Medicine, Japan
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47
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Kitamura M. TGF-β1 as an Endogenous Defender Against Macrophage-Triggered Stromelysin Gene Expression in the Glomerulus. THE JOURNAL OF IMMUNOLOGY 1998. [DOI: 10.4049/jimmunol.160.10.5163] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Abstract
Recent investigation has indicated that TGF-β1, the macrophage (Mφ) deactivator, may attenuate Mφ-mediated acute glomerular injury. Using stromelysin as an indicator, this study investigated whether and how endogenous TGF-β1 modulates the glomerular cell activation triggered by Mφ. Rat mesangial cells were stably transfected with a cDNA encoding the active form of TGF-β1 and a cDNA coding for a dominant-negative mutant of the TGF-βR type II. Compared with mock-transfected cells, TGF-β1 transfectants exhibited blunted expression of stromelysin in response to the Mφ-derived, inflammatory cytokine IL-1β. In contrast, mesangial cells expressing the dominant-interfering TGF-βR showed enhanced expression of stromelysin in response to IL-1β, suggesting that endogenous TGF-β functions as an autocrine inhibitor of the IL-1 response. In isolated, normal rat glomeruli, externally added TGF-β1 suppressed the induction of stromelysin by mediators that were elaborated by activated Mφ. Similarly, when isolated, nephritic glomeruli producing the active form of TGF-β1 were stimulated by IL-1β or Mφ-conditioned medium, the induction of stromelysin was dramatically suppressed as compared with normal glomeruli. To investigate whether endogenous TGF-β1 affects the glomerular cell activation triggered by Mφ, a technique for adoptive Mφ transfer was used. LPS-stimulated reporter Mφ were transferred into either normal rat glomeruli or nephritic glomeruli expressing active TGF-β1. In the normal glomeruli, stromelysin expression was markedly induced in resident cells after the transfer of activated Mφ. This induction was substantially repressed in those glomeruli producing active TGF-β1. These results reinforce the idea that TGF-β1 is an endogenous defender that attenuates certain actions of infiltrating Mφ in the glomerulus.
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Affiliation(s)
- Masanori Kitamura
- Glomerular Bioengineering Unit, Department of Medicine, University College London Medical School, London, United Kingdom
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48
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Harada K, Ogura T, Yamauchi T, Otsuka F, Mimura Y, Hashimoto M, Oishi T, Makino H. Effect of continuous infusion of vasopressin on glomerular growth response in spontaneously hypertensive rats. REGULATORY PEPTIDES 1998; 74:11-8. [PMID: 9657353 DOI: 10.1016/s0167-0115(98)00009-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Vasopressin (VP) is thought to play an important role in the pressor and proliferative responses of renal glomeruli. We have utilized the spontaneously hypertensive rat (SHR) model to determine if glomerular proliferation is induced by chronic infusion of exogenous VP. SHR were continuously infused with 0.1 ng/kg/min VP (H-VP group), 1.0 ng/kg/min (H-VP group), or vehicle alone (control group) for fifteen days using osmotic minipumps, and the histological alterations and level of expression of platelet-derived growth factor B-chain (PDGF-B) and transforming growth factor (TGF)-beta1 mRNA were determined. We observed no significant differences in systolic blood pressure, heart rate, serum electrolytes, protein and creatinine among the three groups of rats, but urine volume was found to be significantly decreased, and urine osmolality significantly increased, in the H-VP group. Kidney weight was significantly higher in the H-VP and L-VP groups than in the control group, and glomerular diameter was higher in the H-VP group. When we measured mesangial injury score and cellularity in the glomeruli of these animals, we observed VP dose-dependent proliferative changes. In the immunofluorescence study, although we did not find an obvious difference in depositions of collagen types III, IV and VI, alpha-smooth muscle actin and PDGF-B among the groups, the collagen type I and TGF-beta1 increased in several glomeruli in the H-VP group. Reverse transcription polymerase chain reaction (RT-PCR) revealed no significant differences in the glomerular levels of PDGF-B mRNA among the three groups of rats, but the level of expression of TGF-beta1 mRNA was significantly higher in the L-VP and H-VP groups than in the control group. These findings suggest that VP may contribute to glomerular proliferation, and that VP may exert its effects in part through the induction of TGF-beta1 expression. These results also raise the possibility that blockade of VP receptors may be useful in the treatment of some forms of glomerular disease.
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Affiliation(s)
- K Harada
- Department of Medicine III, Okayama University Medical School, Japan
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49
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Ying WZ, Sanders PW. Dietary salt modulates renal production of transforming growth factor-beta in rats. THE AMERICAN JOURNAL OF PHYSIOLOGY 1998; 274:F635-41. [PMID: 9575885 DOI: 10.1152/ajprenal.1998.274.4.f635] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Transforming growth factors (TGF) are potent multifunctional polypeptides that are involved in renal function and glomerular sclerosis. We postulated that dietary salt modified renal production of TGF-beta. An increase in dietary salt produced sustained increases in steady-state levels of mRNA for TGF-beta 1, -beta 2, and -beta 3 in the rat kidney. While serum concentration of TGF-beta 1 did not change, the 8.0% NaCl diet increased urinary excretion of TGF-beta 1, indicating enhanced renal production was the source of TGF-beta 1. Increasing urinary flow rates with diuretics did not further increase synthesis of TGF-beta 1 in animals receiving the 8.0% NaCl diet. The 8.0% NaCl diet increased production of TGF-beta 1 in both glomeruli and tubules, although active TGF-beta 1 was secreted in greater amounts only from glomeruli. Enhanced glomerular production of both inactive and active TGF-beta 1 induced by the 8.0% NaCl diet was inhibited by tetraethylammonium (TEA) and not glybenclamide. Cardiac production of TGF-beta 1 also increased on the 8.0% NaCl diet but was not affected by TEA. The results demonstrated that increased dietary salt augmented glomerular TGF-beta production by a mechanism that included a TEA-sensitive potassium channel. Dietary salt, by facilitating glomerular expression of TGF-beta, may directly promote development of glomerulosclerosis.
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Affiliation(s)
- W Z Ying
- Nephrology Research and Training Center, University of Alabama at Birmingham 35294-0007, USA
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50
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García-Ocaña A, Peñaranda C, Esbrit P. Comparison of antiproliferative effects of atrial natriuretic peptide and transforming growth factor beta on rabbit kidney proximal tubule cells. Life Sci 1998; 58:251-8. [PMID: 9499166 DOI: 10.1016/0024-3205(95)02283-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The effects of atrial natriuretic peptide (ANP) and transforming growth factor beta (TGF beta) on cell proliferation were investigated in rabbit kidney proximal tubule cells. At 48 h, each agonist inhibited cell growth dose dependently. Moreover, the antiproliferative effect of both factors together was greater than that of each factor alone. However, coincubation of a high concentration (100 nM) of ANP and epidermal growth factor (EGF) was found to induce cell hypertrophy. This hypertrophic effect induced by ANP in the presence of EGF was mimicked by 8-BrcGMP but not by various cAMP analogues, at 100 microM, and was independent of the tyrosine kinase inhibitor genistein (10 microM). However, it was inhibited by 100 pM TGF beta. These in vitro results suggest that the antiproliferative effects of ANP and TGF beta may be part of a mechanism to modulate the hyperplastic effect of EGF in the renal proximal tubule during compensatory kidney growth.
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Affiliation(s)
- A García-Ocaña
- Laboratorio de la Unidad Metabólica, Fundación Jiménez Díaz, Madrid, Spain
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