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Thotakura S, Basova L, Makarenkova HP. FGF Gradient Controls Boundary Position Between Proliferating and Differentiating Cells and Regulates Lacrimal Gland Growth Dynamics. Front Genet 2019; 10:362. [PMID: 31191595 PMCID: PMC6546953 DOI: 10.3389/fgene.2019.00362] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Accepted: 04/04/2019] [Indexed: 12/17/2022] Open
Abstract
Fibroblast growth factor (FGF) signaling plays an important role in controlling cell proliferation, survival, and cell movements during branching morphogenesis of many organs. In mammals branching morphogenesis is primarily regulated by members of the FGF7-subfamily (FGF7 and FGF10), which are expressed in the mesenchyme, and signal to the epithelial cells through the “b” isoform of fibroblast growth factor receptor-2 (FGFR2). Our previous work demonstrated that FGF7 and FGF10 form different gradients in the extracellular matrix (ECM) and induce distinct cellular responses and gene expression profiles in the lacrimal and submandibular glands. The last finding was the most surprising since both FGF7 and FGF10 bind signal most strongly through the same fibroblast growth factor receptor-2b isoform (FGFR2b). Here we revisit this question to gain an explanation of how the different FGFs regulate gene expression. For this purpose, we employed our ex vivo epithelial explant migration assay in which isolated epithelial explants are grown near the FGF loaded beads. We demonstrate that the graded distribution of FGF induces activation of ERK1/2 MAP kinases that define the position of the boundary between proliferating “bud” and differentiating “stalk” cells of growing lacrimal gland epithelium. Moreover, we showed that gene expression profiles of the epithelial explants exposed to distinct FGFs strictly depend on the ratio between “bud” and “stalk” area. Our data also suggests that differentiation of “stalk” and “bud” regions within the epithelial explants is necessary for directional and persistent epithelial migration. Gaining a better understanding of FGF functions is important for development of new approaches to enhance tissue regeneration.
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Affiliation(s)
- Suharika Thotakura
- Department of Molecular Medicine, The Scripps Research Institute, San Diego, CA, United States
| | - Liana Basova
- Department of Molecular Medicine, The Scripps Research Institute, San Diego, CA, United States
| | - Helen P Makarenkova
- Department of Molecular Medicine, The Scripps Research Institute, San Diego, CA, United States
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Chai C, Song J, Tan Z, Tai I, Zhang C, Sun S. Adipose tissue‐derived stem cells inhibit hypertrophic scar (HS) fibrosis via p38/MAPK pathway. J Cell Biochem 2018; 120:4057-4064. [PMID: 30260015 DOI: 10.1002/jcb.27689] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Accepted: 08/27/2018] [Indexed: 02/05/2023]
Affiliation(s)
- Chi‐Yung Chai
- Department of Breast and Thyroid Surgery Renmin Hospital of Wuhan University Wuhan China
| | - Junlong Song
- Department of Breast and Thyroid Surgery Renmin Hospital of Wuhan University Wuhan China
| | - Zhenwei Tan
- Department of Orthopedic Sursery West China Hospital Chengdu Sichuan China
| | - I‐Chun Tai
- Southern Medical Science Ltd Kaohsiung Taiwan ROC
| | - Chaoying Zhang
- School of Basic Medical Sciences of Guangzhou University of Chinese Medicine, Guangzhou Guangdong China
| | - Shengrong Sun
- Department of Breast and Thyroid Surgery Renmin Hospital of Wuhan University Wuhan China
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Li Y, Zhang W, Gao J, Liu J, Wang H, Li J, Yang X, He T, Guan H, Zheng Z, Han S, Dong M, Han J, Shi J, Hu D. Adipose tissue-derived stem cells suppress hypertrophic scar fibrosis via the p38/MAPK signaling pathway. Stem Cell Res Ther 2016; 7:102. [PMID: 27484727 PMCID: PMC4970202 DOI: 10.1186/s13287-016-0356-6] [Citation(s) in RCA: 82] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2015] [Revised: 06/06/2016] [Accepted: 06/29/2016] [Indexed: 02/17/2023] Open
Abstract
BACKGROUND Hypertrophic scars (HS) generally occur after injury to the deep layers of the dermis, resulting in functional deficiency for patients. Growing evidence has been identified that the supernatant of adipose tissue-derived stem cells (ADSCs) significantly ameliorates fibrosis of different tissues, but limited attention has been paid to its efficacy on attenuating skin fibrosis. In this study, we explored the effect and possible mechanism of ADSC-conditioned medium (ADSC-CM) on HS. METHOD Real-time quantitative polymerase chain reaction (qRT-PCR) and Western blotting were used to detect the expression of collagen I (Col1), collagen III (Col3), and α-smooth muscle actin (α-SMA) after fibroblasts and cultured HS tissues were stimulated with ADSC-CM and p38 inhibitor/activator. Immunofluorescence staining was performed to test the expression of α-SMA. Masson's trichrome staining, hematoxylin and eosin (H&E) staining, and immunohistochemistry staining were carried out to assess the histological and pathological change of collagen in the BALB/c mouse excisional model. All data were analyzed by using SPSS17.0 software. Statistical analysis was performed by Student's t tests. RESULTS The in vitro and ex vivo study revealed ADSC-CM decreased the expression of Col1, Col3, and α-SMA. Together, thinner and orderly arranged collagen was manifested in HS tissues cultured with ADSC-CM. Dramatically, the assessed morphology showed an accelerated healing rate, less collagen deposition, and col1- and col3-positive cells in the ADSC-CM treated group. Importantly, the protein level of p-p38 was downregulated in a concentration-dependent manner in HS-derived fibroblasts with ADSC-CM treatment, which further decreased the expression of p-p38 after the application of its inhibitor, SB203580. SB203580 led to an obvious decline in the expression of Col1, Col3, and α-SMA in fibroblasts and cultured HS tissues and presented more ordered arrangement and thinner collagen fibers in BALB/c mice. Lastly, anisomycin, an agonist of p38, upregulated the expression of fibrotic proteins and revealed more disordered structure and denser collagen fibers. CONCLUSION This study demonstrated that ADSC-CM could decrease collagen deposition and scar formation in in vitro, ex vivo and in vivo experiments. The regulation of the p38/MAPK signaling pathway played an important role in the process. The application of ADSC-CM may provide a novel therapeutic strategy for HS treatment, and the anti-scarring effect can be achieved by inhibition of the p38/MAPK signaling pathway.
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Affiliation(s)
- Yan Li
- Department of Burns and Cutaneous Surgery, Xijing Hospital, Fourth Military Medical University, 127 West Chang-le Road, Xi'an, 710032, China
| | - Wei Zhang
- Department of Burns and Cutaneous Surgery, Xijing Hospital, Fourth Military Medical University, 127 West Chang-le Road, Xi'an, 710032, China
| | - Jianxin Gao
- Department of Burns and Cutaneous Surgery, Xijing Hospital, Fourth Military Medical University, 127 West Chang-le Road, Xi'an, 710032, China
| | - Jiaqi Liu
- Department of Burns and Cutaneous Surgery, Xijing Hospital, Fourth Military Medical University, 127 West Chang-le Road, Xi'an, 710032, China
| | - Hongtao Wang
- Department of Burns and Cutaneous Surgery, Xijing Hospital, Fourth Military Medical University, 127 West Chang-le Road, Xi'an, 710032, China
| | - Jun Li
- Department of Burns and Cutaneous Surgery, Xijing Hospital, Fourth Military Medical University, 127 West Chang-le Road, Xi'an, 710032, China
| | - Xuekang Yang
- Department of Burns and Cutaneous Surgery, Xijing Hospital, Fourth Military Medical University, 127 West Chang-le Road, Xi'an, 710032, China
| | - Ting He
- Department of Burns and Cutaneous Surgery, Xijing Hospital, Fourth Military Medical University, 127 West Chang-le Road, Xi'an, 710032, China
| | - Hao Guan
- Department of Burns and Cutaneous Surgery, Xijing Hospital, Fourth Military Medical University, 127 West Chang-le Road, Xi'an, 710032, China
| | - Zhao Zheng
- Department of Burns and Cutaneous Surgery, Xijing Hospital, Fourth Military Medical University, 127 West Chang-le Road, Xi'an, 710032, China
| | - Shichao Han
- Department of Burns and Cutaneous Surgery, Xijing Hospital, Fourth Military Medical University, 127 West Chang-le Road, Xi'an, 710032, China
| | - Maolong Dong
- Department of Burns and Cutaneous Surgery, Xijing Hospital, Fourth Military Medical University, 127 West Chang-le Road, Xi'an, 710032, China
| | - Juntao Han
- Department of Burns and Cutaneous Surgery, Xijing Hospital, Fourth Military Medical University, 127 West Chang-le Road, Xi'an, 710032, China
| | - Jihong Shi
- Department of Burns and Cutaneous Surgery, Xijing Hospital, Fourth Military Medical University, 127 West Chang-le Road, Xi'an, 710032, China.
| | - Dahai Hu
- Department of Burns and Cutaneous Surgery, Xijing Hospital, Fourth Military Medical University, 127 West Chang-le Road, Xi'an, 710032, China.
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Aguilar-Alonso FA, Solano JD, Vargas-Olvera CY, Pacheco-Bernal I, Pariente-Pérez TO, Ibarra-Rubio ME. MAPKs’ status at early stages of renal carcinogenesis and tumors induced by ferric nitrilotriacetate. Mol Cell Biochem 2015; 404:161-70. [PMID: 25724684 DOI: 10.1007/s11010-015-2375-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2014] [Accepted: 02/23/2015] [Indexed: 12/12/2022]
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Ren Z, Hou Y, Ma S, Tao Y, Li J, Cao H, Ji L. Effects of CCN3 on fibroblast proliferation, apoptosis and extracellular matrix production. Int J Mol Med 2014; 33:1607-12. [PMID: 24715059 DOI: 10.3892/ijmm.2014.1735] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2014] [Accepted: 03/14/2014] [Indexed: 11/06/2022] Open
Abstract
CCN2 and CCN3 belong to the CCN family of proteins, which show a high level of structural similarity.Previous studies have shown that CCN2 mediates the ability of transforming growth factor (TGF)‑β to stimulate collagen synthesis, leading to keloid formation. CCN2 and CCN3 are opposing factors in regulating the promoter activity and secretion of this extracellular matrix (ECM) protein. Thus, we hypothesize that CCN3 possesses an anti‑scarring effect. However, the exact mechanism of CCN3 in this anti‑scarring effect remains unclear. The aim of this study was to investigate the mechanism of CCN3 in reducing scar formation. Palatal fibroblasts were obtained from the explants of the oral palatal mucosa of 8‑week‑old male Sprague‑Dawley rats. CCN3 overexpression vector was constructed and then transfected into cells. The inhibitory effects of CCN3 on cell growth were detected via the 3‑(4,5‑dimethylthiazol‑2‑yl)‑2,5‑diphenyltetrazolium bromide (MTT) assay. Apoptosis was measured using an Annexin V‑fluorescein isothiocyanate (FITC)/propidium iodide (PI) apoptosis detection kit and flow cytometry. The expression levels of collagen I, collagen III and α‑smooth muscle actin (α‑SMA) were determined by western blot analysis and RT‑PCR. Following treatment with TGF‑β1, we detected the expression of CCN3 and Smad1 in the fibroblasts. CCN3 significantly inhibited the growth and induction of apoptosis of fibroblasts. The expression of collagen I, collagen III and α‑SMA was lower in the CCN3‑transfected group as compared to the control and vector groups. TGF‑β1 stimulation efficiently suppressed the expression of CCN3 at the mRNA and protein levels, and CCN3 was required for TGF‑β1‑induced Smad1 phosphorylation. Results of this study demonstrated that CCN3 is involved in the proliferation and apoptosis of fibroblasts and the synthesis of ECM proteins. Therefore, CCN3 may play an important role in the development of scar tissue, and may represent a novel therapeutic target for reducing scar formation.
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Affiliation(s)
- Zhanping Ren
- Department of Cranio‑Maxillofacial Trauma Plastic Surgery, Stomatology Hospital of Xi'an Jiaotong University College of Medicine, Xi'an, Shaanxi 710004, P.R. China
| | - Yuxia Hou
- Department of Orthodontics, Stomatology Hospital of Xi'an Jiaotong University College of Medicine, Xi'an, Shaanxi 710004, P.R. China
| | - Siwei Ma
- Department of Cranio‑Maxillofacial Trauma Plastic Surgery, Stomatology Hospital of Xi'an Jiaotong University College of Medicine, Xi'an, Shaanxi 710004, P.R. China
| | - Yongwei Tao
- Department of Cranio‑Maxillofacial Trauma Plastic Surgery, Stomatology Hospital of Xi'an Jiaotong University College of Medicine, Xi'an, Shaanxi 710004, P.R. China
| | - Jinfeng Li
- Department of Cranio‑Maxillofacial Trauma Plastic Surgery, Stomatology Hospital of Xi'an Jiaotong University College of Medicine, Xi'an, Shaanxi 710004, P.R. China
| | - Huiqin Cao
- Department of Cranio‑Maxillofacial Trauma Plastic Surgery, Stomatology Hospital of Xi'an Jiaotong University College of Medicine, Xi'an, Shaanxi 710004, P.R. China
| | - Lingling Ji
- Department of Orthodontics, Stomatology Hospital of Xi'an Jiaotong University College of Medicine, Xi'an, Shaanxi 710004, P.R. China
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Du QC, Zhang DZ, Chen XJ, Lan-Sun G, Wu M, Xiao WL. The effect of p38MAPK on cyclic stretch in human facial hypertrophic scar fibroblast differentiation. PLoS One 2013; 8:e75635. [PMID: 24130728 PMCID: PMC3794006 DOI: 10.1371/journal.pone.0075635] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2012] [Accepted: 08/17/2013] [Indexed: 02/06/2023] Open
Abstract
Hypertrophic scars (HTS), the excessive deposition of scar tissue by fibroblasts, is one of the most common skin disorders. Fibroblasts derived from surgical scar tissue produce high levels of α-smooth muscle actin (α-SMA) and transforming growth factor-β1 (TGF-β1). However, the molecular mechanisms for this phenomenon is poorly understood. Thus, the purpose of this study was to evaluate the molecular mechanisms of HTS and their potential therapeutic implications. Fibroblasts derived from skin HTS were cultured and characterized in vitro. The fibroblasts were synchronized and randomly assigned to two groups: cyclic stretch and cyclic stretch pre-treated with SB203580 (a p38MAPK inhibitor). Cyclic stretch at 10% strain was applied at a loading frequency of 10 cycles per minute (i.e. 5 seconds of tension and 5 seconds of relaxation) for 0 h, 6 h and 12 h. Cyclic stretch on HTS fibroblasts led to an increase in the expression of α-SMA and TGF-β1 mRNA and protein and the phosphorylation of p38MAPK. SB203580 reversed these effects and caused a decrease in matrix contraction. Furthermore, HTS fibroblast growth was partially blocked by p38MAPK inhibition. Therefore, the mechanism of cyclic stretch involves p38 MAPK, and its inhibition is suggested as a novel therapeutic strategy for HTS.
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Affiliation(s)
- Qi-cui Du
- Department of Stomatology, The Affiliated Hospital of Medical College, Qingdao University, Qingdao, the People's Republic of China
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Lu H, Kapur G, Mattoo TK, Lyman WD. Hypoxia decreases podocyte expression of slit diaphragm proteins. Int J Nephrol Renovasc Dis 2012; 5:101-7. [PMID: 22888268 PMCID: PMC3413038 DOI: 10.2147/ijnrd.s27332] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Background Chronic hypoxia contributes to progressive tubulointerstitial injury and, consequently, renal failure. However, the effect of hypoxia on glomerular podocytes, which are integral to the slit diaphragm complex and responsible for selectivity of the glomerular filtration barrier, has not been completely determined. Methods Conditionally immortalized mouse podocyte cells were exposed to hypoxic (1% O2) or normoxic (room air) conditions for 24, 48, or 72 hours, after which cell viability was determined by MTT assay. Cells were stained with podocin and phalloidin to determine podocin and intracellular actin distribution. Expression of synaptopodin, CD2-associated protein (CD2AP), NcK, transforming growth factor-β1 (TGF-β1), hypoxia-inducible factor (HIF-1α) were evaluated by real-time polymerase chain reaction. Results Podocytes exposed to hypoxia had significantly reduced viability at 48 (87%) and 72 hours (66%). There was disarrangement of intracellular filament actin by phalloidin staining, a 30% weaker fluorescence intensity by podocin staining, significantly reduced expression of synaptopodin (12%), CD2AP (42%), NcK (38%), and increased expression of TGF-β1 and P-ERK after hypoxia treatment. Conclusion Podocyte exposure to hypoxia leads to reduced viability and SD protein expression, which may explain persistent and/or increasing proteinuria in patients with progressive renal failure. Increased expression of TGF-β1 and P-ERK is associated with apoptosis and fibrosis, which could be the link between hypoxia and glomerular injury.
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Affiliation(s)
- Hong Lu
- Carman and Ann Adams Department of Pediatrics, Children's Hospital of Michigan, Detroit, MI, USA
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Pan J, Seeger-Nukpezah T, Golemis EA. The role of the cilium in normal and abnormal cell cycles: emphasis on renal cystic pathologies. Cell Mol Life Sci 2012; 70:1849-74. [PMID: 22782110 DOI: 10.1007/s00018-012-1052-z] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2012] [Revised: 05/08/2012] [Accepted: 06/05/2012] [Indexed: 12/28/2022]
Abstract
The primary cilium protrudes from the cell surface and acts as a sensor for chemical and mechanical growth cues, with receptors for a number of growth factors (PDGFα, Hedgehog, Wnt, Notch) concentrated within the ciliary membrane. In normal tissues, the cilium assembles after cells exit mitosis and is resorbed as part of cell cycle re-entry. Although regulation of the cilium by cell cycle transitions has been appreciated for over 100 years, only recently have data emerged to indicate the cilium also exerts influence on the cell cycle. The resorption/protrusion cycle, regulated by proteins including Aurora-A, VHL, and GSK-3β, influences cell responsiveness to growth cues involving cilia-linked receptors; further, resorption liberates the ciliary basal body to differentiate into the centrosome, which performs discrete functions in S-, G2-, and M-phase. Besides these roles, the cilium provides a positional cue that regulates polarity of cell division, and thus directs cells towards fates of differentiation versus proliferation. In this review, we summarize the specific mechanisms mediating the cilia-cell cycle dialog. We then emphasize the examples of polycystic kidney disease (PKD), nephronopthisis (NPHP), and VHL-linked renal cysts as cases in which defects of ciliary function influence disease pathology, and may also condition response to treatment.
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Affiliation(s)
- Junmin Pan
- Protein Science Laboratory of the Ministry of Education, School of Life Sciences, Tsinghua University, Beijing, 100084, China.
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Sethi A, Mao W, Wordinger RJ, Clark AF. Transforming growth factor-beta induces extracellular matrix protein cross-linking lysyl oxidase (LOX) genes in human trabecular meshwork cells. Invest Ophthalmol Vis Sci 2011; 52:5240-50. [PMID: 21546528 PMCID: PMC3176072 DOI: 10.1167/iovs.11-7287] [Citation(s) in RCA: 152] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2011] [Revised: 04/03/2011] [Accepted: 04/05/2011] [Indexed: 01/19/2023] Open
Abstract
PURPOSE The profibrotic cytokine TGFβ is associated with glaucoma and plays an important role in the regulation of extracellular matrix metabolism in the trabecular meshwork (TM). The purpose of this study was to determine whether expression of ECM cross-linking LOX genes is regulated by TGFβ in TM cells. METHODS Expression of the five LOX genes (LOX, LOXL1, LOXL2, LOXL3, and LOXL4) was examined in cultured human TM cells by using RT-PCR, quantitative RT-PCR, and Western immunoblot analysis. TM cells were treated with recombinant TGFβ1, -2, and -3, to determine the effects on LOX and LOXL1 to -4 expression. The TM cells were pretreated with TGFBR inhibitors (LY364947, SB431542), canonical Smad signaling pathway (SIS3 or Smad2, -3, and -4 siRNAs) inhibitors, or inhibitors of the non-Smad signaling pathways (SP600125, SR11302), to identify the signaling pathway(s) involved in TGFβ induction of LOX and LOXL gene and protein expression. A novel LOX activity assay was used to determine the effects of the LOX inhibitor BAPN on tropoelastin cross-linking. RESULTS All five LOX genes (LOX, LOXL1 to -4) were expressed in cultured human TM cells and were induced by all three isoforms of TGFβ. This TGFβ induction of LOX and LOXL expression was blocked by TGFβ inhibitors as well as by inhibitors of the canonical Smad2, -3, and -4 signaling and non-Smad JNK/AP-1 signaling pathways (P < 0.05). CONCLUSIONS Both Smad and non-Smad signaling pathways are involved in TGFβ-mediated LOX induction, suggesting complex regulation of these important extracellular matrix cross-linking enzymes. Increased LOX activity may be at least partially responsible for TGFβ-mediated IOP elevation and increased aqueous humor outflow resistance.
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Affiliation(s)
- Anirudh Sethi
- From the Department of Cell Biology and Anatomy, North Texas Eye Research Institute (NTERI), University of North Texas Health Science Center, Fort Worth, Texas
| | - Weiming Mao
- From the Department of Cell Biology and Anatomy, North Texas Eye Research Institute (NTERI), University of North Texas Health Science Center, Fort Worth, Texas
| | - Robert J. Wordinger
- From the Department of Cell Biology and Anatomy, North Texas Eye Research Institute (NTERI), University of North Texas Health Science Center, Fort Worth, Texas
| | - Abbot F. Clark
- From the Department of Cell Biology and Anatomy, North Texas Eye Research Institute (NTERI), University of North Texas Health Science Center, Fort Worth, Texas
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Sethi A, Jain A, Zode GS, Wordinger RJ, Clark AF. Role of TGFbeta/Smad signaling in gremlin induction of human trabecular meshwork extracellular matrix proteins. Invest Ophthalmol Vis Sci 2011; 52:5251-9. [PMID: 21642622 DOI: 10.1167/iovs.11-7587] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
PURPOSE The bone morphogenic protein (BMP) antagonist gremlin is elevated in glaucomatous trabecular meshwork (TM) cells and tissues and elevates intraocular pressure (IOP). Gremlin also blocks BMP4 inhibition of transforming growth factor (TGF)-β2 induction of TM extracellular matrix (ECM) proteins. The purpose of this study was to determine whether Gremlin regulates ECM proteins in cultured human TM cells. METHODS Human TM cells were treated with recombinant gremlin to determine the effects on ECM gene and protein expression. Expression of the ECM genes FN, COL1, PAI1, and ELN was examined in cultured human TM cells by quantitative RT-PCR and Western immunoblot analysis. TM cells were pretreated with TGFBR inhibitors (LY364947, SB431542 or TGFBR1/TGFB2 siRNAs), inhibitors of the Smad signaling pathway (SIS3 or Smad2/3/4 siRNAs), or CTGF siRNA to identify the signaling pathway(s) involved in gremlin induction of ECM gene and protein expression. RESULTS All ECM genes analyzed (FN, COL1, PAI1, and ELN) were induced by gremlin. This gremlin induction of ECM genes and protein expression was blocked by inhibitors of TGFBR and the canonical Smad2/3/4 and CTGF signaling pathways. CONCLUSIONS Gremlin employs canonical TGFβ2/Smad signaling to induce ECM genes and proteins in cultured human TM cells. Gremlin also induces both TGFβ2 and CTGF, which can act downstream to mediate some of these ECM changes in TM cells.
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Affiliation(s)
- Anirudh Sethi
- Department of Cell Biology and Anatomy, North Texas Eye Research Institute, University of North Texas Health Science Center, Fort Worth, Texas 76107, USA
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Fujita H, Hida M, Kanemoto K, Fukuda K, Nagata M, Awazu M. Cyclic stretch induces proliferation and TGF-β1-mediated apoptosis via p38 and ERK in ureteric bud cells. Am J Physiol Renal Physiol 2010; 299:F648-55. [DOI: 10.1152/ajprenal.00402.2009] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We previously reported that p38 mitogen-activated protein kinase (p38) and phosphorylated ERK are upregulated in cyst epithelium of human renal dysplasia and obstructive uropathy in fetal lambs (Omori S, Fukuzawa R, Hida M, Awazu M. Kidney Int 61: 899–906, 2002; Omori S, Kitagawa H, Koike J, Fujita H, Hida M, Pringle KC, Awazu M. Kidney Int 73: 1031–1037, 2008). Dysplastic epithelium is characterized by proliferation, apoptosis, and upregulation of Pax2 and transforming growth factor (TGF)-β1. In the present study, we investigated whether cyclic mechanical stretching of ureteric bud cells, a mimic of the hydrodynamic derangement after fetal urinary tract obstruction, reproduces events seen in vivo. Cyclic stretch activated p38 and ERK and upregulated Pax2 expression in a time-dependent manner in ureteric bud cells. Stretch-stimulated Pax2 expression was suppressed by a p38 inhibitor, SB203580, or a MEK inhibitor, PD98059. 5-Deoxyuridine incorporation was increased by stretch at 24 h, which was also abolished by SB203580 or PD98059. On the other hand, apoptosis was not induced at 24 h by stretch but was significantly increased at 48 h. TGF-β1 secretion was increased by stretch at 24 h, which was inhibited by SB203580 or PD98059. Inhibition of p38 or ERK as well as anti-TGF-β antibody abolished the stretch-induced apoptosis. Finally, exogenous TGF-β1 induced apoptosis of ureteric bud cells, which was inhibited by SB203580 and PD98059. In conclusion, cyclic stretch induces Pax2 upregulation, proliferation, and TGF-β1-mediated apoptosis, features characteristic of dysplastic epithelium, via p38 and ERK in ureteric bud cells.
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Affiliation(s)
| | | | - Katsuyoshi Kanemoto
- Department of Molecular Pathology, Institute of Basic Medical Sciences, Graduate School of Comprehensive Human Sciences, University of Tsukuba, Ibaraki, Japan
| | - Keiichi Fukuda
- Regenerative Medicine and Advanced Cardiac Therapeutics, Keio University School of Medicine, Tokyo; and
| | - Michio Nagata
- Department of Molecular Pathology, Institute of Basic Medical Sciences, Graduate School of Comprehensive Human Sciences, University of Tsukuba, Ibaraki, Japan
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