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Akkız H, Gieseler RK, Canbay A. Liver Fibrosis: From Basic Science towards Clinical Progress, Focusing on the Central Role of Hepatic Stellate Cells. Int J Mol Sci 2024; 25:7873. [PMID: 39063116 PMCID: PMC11277292 DOI: 10.3390/ijms25147873] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2024] [Revised: 06/28/2024] [Accepted: 06/29/2024] [Indexed: 07/28/2024] Open
Abstract
The burden of chronic liver disease is globally increasing at an alarming rate. Chronic liver injury leads to liver inflammation and fibrosis (LF) as critical determinants of long-term outcomes such as cirrhosis, liver cancer, and mortality. LF is a wound-healing process characterized by excessive deposition of extracellular matrix (ECM) proteins due to the activation of hepatic stellate cells (HSCs). In the healthy liver, quiescent HSCs metabolize and store retinoids. Upon fibrogenic activation, quiescent HSCs transdifferentiate into myofibroblasts; lose their vitamin A; upregulate α-smooth muscle actin; and produce proinflammatory soluble mediators, collagens, and inhibitors of ECM degradation. Activated HSCs are the main effector cells during hepatic fibrogenesis. In addition, the accumulation and activation of profibrogenic macrophages in response to hepatocyte death play a critical role in the initiation of HSC activation and survival. The main source of myofibroblasts is resident HSCs. Activated HSCs migrate to the site of active fibrogenesis to initiate the formation of a fibrous scar. Single-cell technologies revealed that quiescent HSCs are highly homogenous, while activated HSCs/myofibroblasts are much more heterogeneous. The complex process of inflammation results from the response of various hepatic cells to hepatocellular death and inflammatory signals related to intrahepatic injury pathways or extrahepatic mediators. Inflammatory processes modulate fibrogenesis by activating HSCs and, in turn, drive immune mechanisms via cytokines and chemokines. Increasing evidence also suggests that cellular stress responses contribute to fibrogenesis. Recent data demonstrated that LF can revert even at advanced stages of cirrhosis if the underlying cause is eliminated, which inhibits the inflammatory and profibrogenic cells. However, despite numerous clinical studies on plausible drug candidates, an approved antifibrotic therapy still remains elusive. This state-of-the-art review presents cellular and molecular mechanisms involved in hepatic fibrogenesis and its resolution, as well as comprehensively discusses the drivers linking liver injury to chronic liver inflammation and LF.
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Affiliation(s)
- Hikmet Akkız
- Department of Gastroenterology and Hepatology, University of Bahçeşehir, Beşiktaş, Istanbul 34353, Turkey
| | - Robert K. Gieseler
- Department of Internal Medicine, University Hospital Knappschaftskrankenhaus, Ruhr University Bochum, In der Schornau 23–25, 44892 Bochum, Germany; (R.K.G.); (A.C.)
| | - Ali Canbay
- Department of Internal Medicine, University Hospital Knappschaftskrankenhaus, Ruhr University Bochum, In der Schornau 23–25, 44892 Bochum, Germany; (R.K.G.); (A.C.)
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Kisseleva T, Brenner D. Molecular and cellular mechanisms of liver fibrosis and its regression. Nat Rev Gastroenterol Hepatol 2021; 18:151-166. [PMID: 33128017 DOI: 10.1038/s41575-020-00372-7] [Citation(s) in RCA: 766] [Impact Index Per Article: 255.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 09/23/2020] [Indexed: 01/18/2023]
Abstract
Chronic liver injury leads to liver inflammation and fibrosis, through which activated myofibroblasts in the liver secrete extracellular matrix proteins that generate the fibrous scar. The primary source of these myofibroblasts are the resident hepatic stellate cells. Clinical and experimental liver fibrosis regresses when the causative agent is removed, which is associated with the elimination of these activated myofibroblasts and resorption of the fibrous scar. Understanding the mechanisms of liver fibrosis regression could identify new therapeutic targets to treat liver fibrosis. This Review summarizes studies of the molecular mechanisms underlying the reversibility of liver fibrosis, including apoptosis and the inactivation of hepatic stellate cells, the crosstalk between the liver and the systems that orchestrate the recruitment of bone marrow-derived macrophages (and other inflammatory cells) driving fibrosis resolution, and the interactions between various cell types that lead to the intracellular signalling that induces fibrosis or its regression. We also discuss strategies to target hepatic myofibroblasts (for example, via apoptosis or inactivation) and the myeloid cells that degrade the matrix (for example, via their recruitment to fibrotic liver) to facilitate fibrosis resolution and liver regeneration.
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Affiliation(s)
- Tatiana Kisseleva
- Department of Surgery, University of California, San Diego, La Jolla, CA, USA.
| | - David Brenner
- Department of Medicine, University of California, San Diego, La Jolla, CA, USA
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3
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Fresta CG, Fidilio A, Lazzarino G, Musso N, Grasso M, Merlo S, Amorini AM, Bucolo C, Tavazzi B, Lazzarino G, Lunte SM, Caraci F, Caruso G. Modulation of Pro-Oxidant and Pro-Inflammatory Activities of M1 Macrophages by the Natural Dipeptide Carnosine. Int J Mol Sci 2020; 21:ijms21030776. [PMID: 31991717 PMCID: PMC7038063 DOI: 10.3390/ijms21030776] [Citation(s) in RCA: 65] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Revised: 12/23/2019] [Accepted: 01/22/2020] [Indexed: 12/21/2022] Open
Abstract
Carnosine is a natural endogenous dipeptide widely distributed in mammalian tissues, existing at particularly high concentrations in the muscles and brain and possesses well-characterized antioxidant and anti-inflammatory activities. In an in vitro model of macrophage activation, induced by lipopolysaccharide + interferon-gamma (LPS + IFN-γ), we here report the ability of carnosine to modulate pro-oxidant and pro-inflammatory activities of macrophages, representing the primary cell type that is activated as a part of the immune response. An ample set of parameters aimed to evaluate cytotoxicity (MTT assay), energy metabolism (HPLC), gene expressions (high-throughput real-time PCR (qRT-PCR)), protein expressions (western blot) and nitric oxide production (qRT-PCR and HPLC), was used to assess the effects of carnosine on activated macrophages challenged with a non cytotoxic LPS (100 ng/mL) + IFN-γ (600 U/mL) concentration. In our experimental model, main carnosine beneficial effects were: (1) the modulation of nitric oxide production and metabolism; (2) the amelioration of the macrophage energy state; (3) the decrease of the expressions of pro-oxidant enzymes (Nox-2, Cox-2) and of the lipid peroxidation product malondialdehyde; (4) the restoration and/or increase of the expressions of antioxidant enzymes (Gpx1, SOD-2 and Cat); (5) the increase of the transforming growth factor-β1 (TGF-β1) and the down-regulation of the expressions of interleukins 1β and 6 (IL-1β and IL-6) and 6) the increase of the expressions of Nuclear factor (erythroid-derived 2)-like 2 (Nrf2) and heme oxygenase-1 (HO-1). According to these results carnosine is worth being tested in the treatment of diseases characterized by elevated levels of oxidative stress and inflammation (atherosclerosis, cancer, depression, metabolic syndrome, and neurodegenerative diseases).
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Affiliation(s)
- Claudia G. Fresta
- Ralph N. Adams Institute for Bioanalytical Chemistry, University of Kansas, Lawrence, KS 66047-1620, USA; (C.G.F.); (S.M.L.)
- Department of Pharmaceutical Chemistry, University of Kansas, Lawrence, KS 66047-1620, USA
| | - Annamaria Fidilio
- Department of Drug Sciences, University of Catania, 95125 Catania, Italy; (A.F.); (M.G.); (F.C.)
| | - Giacomo Lazzarino
- UniCamillus—Saint Camillus International University of Health Sciences, 00131 Rome, Italy;
| | - Nicolò Musso
- Bio-nanotech Research and Innovation Tower (BRIT), University of Catania, 95125 Catania, Italy;
| | - Margherita Grasso
- Department of Drug Sciences, University of Catania, 95125 Catania, Italy; (A.F.); (M.G.); (F.C.)
- Oasi Research Institute—IRCCS, 94018 Troina (EN), Italy
| | - Sara Merlo
- Department of Biomedical and Biotechnological Sciences, University of Catania, 95125 Catania, Italy; (S.M.); (A.M.A.); (C.B.)
| | - Angela M. Amorini
- Department of Biomedical and Biotechnological Sciences, University of Catania, 95125 Catania, Italy; (S.M.); (A.M.A.); (C.B.)
| | - Claudio Bucolo
- Department of Biomedical and Biotechnological Sciences, University of Catania, 95125 Catania, Italy; (S.M.); (A.M.A.); (C.B.)
| | - Barbara Tavazzi
- Institute of Biochemistry and Clinical Biochemistry, Catholic University of Rome, 00168 Rome, Italy;
- Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168 Rome, Italy
| | - Giuseppe Lazzarino
- Department of Biomedical and Biotechnological Sciences, University of Catania, 95125 Catania, Italy; (S.M.); (A.M.A.); (C.B.)
- Correspondence: (G.L.); (G.C.)
| | - Susan M. Lunte
- Ralph N. Adams Institute for Bioanalytical Chemistry, University of Kansas, Lawrence, KS 66047-1620, USA; (C.G.F.); (S.M.L.)
- Department of Pharmaceutical Chemistry, University of Kansas, Lawrence, KS 66047-1620, USA
- Department of Chemistry, University of Kansas, Lawrence, KS 66047-1620, USA
| | - Filippo Caraci
- Department of Drug Sciences, University of Catania, 95125 Catania, Italy; (A.F.); (M.G.); (F.C.)
- Oasi Research Institute—IRCCS, 94018 Troina (EN), Italy
| | - Giuseppe Caruso
- Oasi Research Institute—IRCCS, 94018 Troina (EN), Italy
- Correspondence: (G.L.); (G.C.)
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Caruso G, Fresta CG, Fidilio A, O'Donnell F, Musso N, Lazzarino G, Grasso M, Amorini AM, Tascedda F, Bucolo C, Drago F, Tavazzi B, Lazzarino G, Lunte SM, Caraci F. Carnosine Decreases PMA-Induced Oxidative Stress and Inflammation in Murine Macrophages. Antioxidants (Basel) 2019; 8:E281. [PMID: 31390749 PMCID: PMC6720685 DOI: 10.3390/antiox8080281] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2019] [Revised: 07/23/2019] [Accepted: 07/31/2019] [Indexed: 02/06/2023] Open
Abstract
Carnosine is an endogenous dipeptide composed of β-alanine and L-histidine. This naturally occurring molecule is present at high concentrations in several mammalian excitable tissues such as muscles and brain, while it can be found at low concentrations in a few invertebrates. Carnosine has been shown to be involved in different cellular defense mechanisms including the inhibition of protein cross-linking, reactive oxygen and nitrogen species detoxification as well as the counteraction of inflammation. As a part of the immune response, macrophages are the primary cell type that is activated. These cells play a crucial role in many diseases associated with oxidative stress and inflammation, including atherosclerosis, diabetes, and neurodegenerative diseases. In the present study, carnosine was first tested for its ability to counteract oxidative stress. In our experimental model, represented by RAW 264.7 macrophages challenged with phorbol 12-myristate 13-acetate (PMA) and superoxide dismutase (SOD) inhibitors, carnosine was able to decrease the intracellular concentration of superoxide anions (O2-•) as well as the expression of Nox1 and Nox2 enzyme genes. This carnosine antioxidant activity was accompanied by the attenuation of the PMA-induced Akt phosphorylation, the down-regulation of TNF-α and IL-6 mRNAs, and the up-regulation of the expression of the anti-inflammatory mediators IL-4, IL-10, and TGF-β1. Additionally, when carnosine was used at the highest dose (20 mM), there was a generalized amelioration of the macrophage energy state, evaluated through the increase both in the total nucleoside triphosphate concentrations and the sum of the pool of intracellular nicotinic coenzymes. Finally, carnosine was able to decrease the oxidized (NADP+)/reduced (NADPH) ratio of nicotinamide adenine dinucleotide phosphate in a concentration dependent manner, indicating a strong inhibitory effect of this molecule towards the main source of reactive oxygen species in macrophages. Our data suggest a multimodal mechanism of action of carnosine underlying its beneficial effects on macrophage cells under oxidative stress and inflammation conditions.
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Affiliation(s)
- Giuseppe Caruso
- Department of Laboratories, Oasi Research Institute-IRCCS, 94018 Troina, Italy.
| | - Claudia G Fresta
- Ralph N. Adams Institute for Bioanalytical Chemistry, University of Kansas, Lawrence, KS 66047-1620, USA
- Department of Pharmaceutical Chemistry, University of Kansas, Lawrence, KS 66047-1620, USA
| | - Annamaria Fidilio
- Department of Drug Sciences, University of Catania, 95125 Catania, Italy
| | - Fergal O'Donnell
- School of Biotechnology, Dublin City University, D09W6Y4 Dublin, Ireland
| | - Nicolò Musso
- Bio-Nanotech Research and Innovation Tower (BRIT), University of Catania, 95125 Catania, Italy
| | - Giacomo Lazzarino
- Institute of Biochemistry and Clinical Biochemistry, Catholic University of Rome, 00168 Rome, Italy
- Fondazione Policlinico Universitario A. Gemelli IRCCS, Largo A. Gemelli 8, 00168 Rome, Italy
| | - Margherita Grasso
- Department of Laboratories, Oasi Research Institute-IRCCS, 94018 Troina, Italy
- Department of Drug Sciences, University of Catania, 95125 Catania, Italy
| | - Angela M Amorini
- Department of Biomedical and Biotechnological Sciences, University of Catania, 95125 Catania, Italy
| | - Fabio Tascedda
- Department of Life Sciences, University of Modena and Reggio Emilia, 41125 Modena, Italy
- Center for Neuroscience and Neurotechnology, University of Modena and Reggio Emilia, 41125 Modena, Italy
| | - Claudio Bucolo
- Department of Biomedical and Biotechnological Sciences, University of Catania, 95125 Catania, Italy
| | - Filippo Drago
- Department of Biomedical and Biotechnological Sciences, University of Catania, 95125 Catania, Italy
| | - Barbara Tavazzi
- Institute of Biochemistry and Clinical Biochemistry, Catholic University of Rome, 00168 Rome, Italy
- Fondazione Policlinico Universitario A. Gemelli IRCCS, Largo A. Gemelli 8, 00168 Rome, Italy
| | - Giuseppe Lazzarino
- Department of Biomedical and Biotechnological Sciences, University of Catania, 95125 Catania, Italy.
| | - Susan M Lunte
- Ralph N. Adams Institute for Bioanalytical Chemistry, University of Kansas, Lawrence, KS 66047-1620, USA
- Department of Pharmaceutical Chemistry, University of Kansas, Lawrence, KS 66047-1620, USA
- Department of Chemistry, University of Kansas, Lawrence, KS 66047-1620, USA
| | - Filippo Caraci
- Department of Laboratories, Oasi Research Institute-IRCCS, 94018 Troina, Italy
- Department of Drug Sciences, University of Catania, 95125 Catania, Italy
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Rekik R, Smiti Khanfir M, Larbi T, Zamali I, Beldi-Ferchiou A, Kammoun O, Marzouki S, Hamzaoui S, Mrad S, Barbouche MR, Houman MH, Ben Ahmed M. Impaired TGF-β signaling in patients with active systemic lupus erythematosus is associated with an overexpression of IL-22. Cytokine 2018; 108:182-189. [PMID: 29684755 DOI: 10.1016/j.cyto.2018.04.011] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Revised: 03/15/2018] [Accepted: 04/07/2018] [Indexed: 12/29/2022]
Abstract
The mechanisms leading to the disruption of self-tolerance in systemic lupus erythematosus (SLE) remain elusive. Herein, we aimed to decipher the molecular basis of the impaired response of mononuclear cells to TGF-β1. The Smad3-pathway was explored on CD3+ lymphocytes in either active or non active SLE patients. An impaired transcription of TGF-β1 target genes was demonstrated in the CD3+ lymphocytes of active SLE patients confirming that the defect involves T cells and pointing to its extrinsic nature. We further demonstrate that the defect did not result from an impaired TGF-βRII expression or Smad2/3 phosphorylation suggesting that the mechanism lies downstream Smad2/3 translocation. Interestingly, the TGF-1 signaling defect did not correlate with an increased expression of soluble or membrane-bound IL-15. However, it was associated with an overexpression of IL-22. This suggests that an excessive activation of AhR pathway (through UV radiations, infections, etc.) could lead to the inhibition of immunosuppressive actions of TGF-β thus disrupting immune homeostasis in SLE. Collectively, our data suggest that the impaired response to TGF-β in SLE patients is associated with disease activity and provide new insights into the pathogenesis of SLE since it could establish the link between the environmental factors and the aberrancies of the immune system usually described in SLE.
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Affiliation(s)
- Raja Rekik
- Laboratory of Transmission, Control and Immunobiology of Infections, LR11IPT02, Institut Pasteur de Tunis, 1002 Tunis, Tunisia
| | - Monia Smiti Khanfir
- Department of Internal Medicine, La Rabta Hospital, Tunis, Tunisia; Faculté de Médecine de Tunis, Université Tunis El Manar, Tunis, Tunisia
| | - Thara Larbi
- Faculté de Médecine de Tunis, Université Tunis El Manar, Tunis, Tunisia; Department of Internal Medicine, Mongi Slim Hospital, Tunis, Tunisia
| | - Imen Zamali
- Laboratory of Clinical Immunology, Tunis, Tunisia
| | - Asma Beldi-Ferchiou
- Department of Biological Hematology and Immunology, Assistance Publique Hôpiaux de Paris (AP-HP), Groupe Hospitalier Mondor, Créteil, France
| | - Ons Kammoun
- Laboratory of Clinical Immunology, Tunis, Tunisia
| | - Soumaya Marzouki
- Laboratory of Transmission, Control and Immunobiology of Infections, LR11IPT02, Institut Pasteur de Tunis, 1002 Tunis, Tunisia
| | - Saloua Hamzaoui
- Faculté de Médecine de Tunis, Université Tunis El Manar, Tunis, Tunisia; Department of Internal Medicine, Mongi Slim Hospital, Tunis, Tunisia
| | - Skander Mrad
- Faculté de Médecine de Tunis, Université Tunis El Manar, Tunis, Tunisia; Department of Internal Medicine, Mongi Slim Hospital, Tunis, Tunisia
| | - Mohamed Ridha Barbouche
- Laboratory of Transmission, Control and Immunobiology of Infections, LR11IPT02, Institut Pasteur de Tunis, 1002 Tunis, Tunisia; Faculté de Médecine de Tunis, Université Tunis El Manar, Tunis, Tunisia
| | - Mohamed Habib Houman
- Department of Internal Medicine, La Rabta Hospital, Tunis, Tunisia; Faculté de Médecine de Tunis, Université Tunis El Manar, Tunis, Tunisia
| | - Melika Ben Ahmed
- Laboratory of Transmission, Control and Immunobiology of Infections, LR11IPT02, Institut Pasteur de Tunis, 1002 Tunis, Tunisia; Faculté de Médecine de Tunis, Université Tunis El Manar, Tunis, Tunisia.
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Liu T, Yang T, Pan T, Liu C, Li S. Effect of Low-Selenium/High-Fat Diet on Pig Peripheral Blood Lymphocytes: Perspectives from Selenoproteins, Heat Shock Proteins, and Cytokines. Biol Trace Elem Res 2018; 183:102-113. [PMID: 28812292 DOI: 10.1007/s12011-017-1122-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/23/2017] [Accepted: 08/04/2017] [Indexed: 01/15/2023]
Abstract
The aim of the present study was to clarify the effect of low selenium (Se)/high fat on the mRNA expression of selenoproteins, heat shock proteins (HSPs) and cytokines in pig peripheral blood lymphocytes. Forty crossbred boar piglets with healthy lean body weights of 10 kg were randomly divided into four treatment groups (group C, group L-Se, group H-fat, and group L-Se-H-fat) (n = 10/group) and fed with the corresponding diet for 16 weeks. The pig peripheral blood lymphocytes were extracted, and the mRNA expression of selenoproteins, HSPs, and cytokines was measured. Most mRNA levels for selenoproteins decreased in group L-Se, group H-fat, and group L-Se-H-fat, except Gpx1, Gpx2, Selt, and Selm, which were elevated in group H-fat. At the same time, low-Se/high-fat diet increased the expression of HSPs (HSP40, HSP60, HSP70, and HSP90) and inflammatory cytokines (IL-1α, IL-1β, IL-6, IL-8, IL-9, iNOS, COX-2, NF-κB, and TNF-α) in group L-Se, group H-fat, and group L-Se-H-fat, and genes in group L-Se-H-fat showed greater increases. Also, low-Se/high-fat diet inhibits the expression of TGF-β1 and IFN-γ. In summary, a low-Se/high-fat diet can cause relevant selenoprotein expression changes and promote the expression of pro-inflammatory factors and HSPs, and low Se enhances the expression of HSPs and inflammation factors induced by high fat. This information is helpful for understanding the effects of low-Se and high-fat diet on pig peripheral blood lymphocytes.
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Affiliation(s)
- Tianqi Liu
- College of Veterinary Medicine, Northeast Agricultural University, Harbin, 150030, People's Republic of China
| | - Tianshu Yang
- College of Veterinary Medicine, Northeast Agricultural University, Harbin, 150030, People's Republic of China
| | - Tingru Pan
- College of Veterinary Medicine, Northeast Agricultural University, Harbin, 150030, People's Republic of China
| | - Ci Liu
- College of Veterinary Medicine, Northeast Agricultural University, Harbin, 150030, People's Republic of China
| | - Shu Li
- College of Veterinary Medicine, Northeast Agricultural University, Harbin, 150030, People's Republic of China.
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Zeisberg M, Tampe B, LeBleu V, Tampe D, Zeisberg EM, Kalluri R. Thrombospondin-1 deficiency causes a shift from fibroproliferative to inflammatory kidney disease and delays onset of renal failure. THE AMERICAN JOURNAL OF PATHOLOGY 2014; 184:2687-98. [PMID: 25111226 PMCID: PMC4715225 DOI: 10.1016/j.ajpath.2014.06.014] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2013] [Revised: 06/06/2014] [Accepted: 06/12/2014] [Indexed: 12/25/2022]
Abstract
Thrombospondin-1 (TSP1) is a multifunctional matricellular protein known to promote progression of chronic kidney disease. To gain insight into the underlying mechanisms through which TSP1 accelerates chronic kidney disease, we compared disease progression in Col4a3 knockout (KO) mice, which develop spontaneous kidney failure, with that of Col4a3;Tsp1 double-knockout (DKO) mice. Decline of excretory renal function was significantly delayed in the absence of TSP1. Although Col4a3;Tsp1 DKO mice did progress toward end-stage renal failure, their kidneys exhibited distinct histopathological lesions, compared with creatinine level-matched Col4a3 KO mice. Although kidneys of both Col4a3 KO and Col4a3;Tsp1 DKO mice exhibited a widened tubulointerstitium, predominant lesions in Col4a3 KO kidneys were collagen deposition and fibroblast accumulation, whereas in Col4a3;Tsp1 DKO kidney inflammation was predominant, with less collagen deposition. Altered disease progression correlated with impaired activation of transforming growth factor-β1 (TGF-β1) in vivo and in vitro in the absence of TSP1. In summary, our findings suggest that TSP1 contributes to progression of chronic kidney disease by catalyzing activation of latent TGF-β1, resulting in promotion of a fibroproliferative response over an inflammatory response. Furthermore, the findings suggest that fibroproliferative and inflammatory lesions are independent entities, both of which contribute to decline of renal function.
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Affiliation(s)
- Michael Zeisberg
- Department of Nephrology and Rheumatology, Göttingen University Medical Center, Georg August University, Göttingen, Germany; Division of Matrix Biology, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts.
| | - Björn Tampe
- Department of Nephrology and Rheumatology, Göttingen University Medical Center, Georg August University, Göttingen, Germany; Division of Matrix Biology, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
| | - Valerie LeBleu
- Division of Matrix Biology, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts; Department of Cancer Biology and the Metastasis Research Center, University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Desiree Tampe
- Department of Nephrology and Rheumatology, Göttingen University Medical Center, Georg August University, Göttingen, Germany; Division of Matrix Biology, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
| | - Elisabeth M Zeisberg
- Department of Cardiology and Pneumology, Göttingen University Medical Center, Georg August University, Göttingen, Germany; Department of Cancer Biology and the Metastasis Research Center, University of Texas MD Anderson Cancer Center, Houston, Texas; German Center for Cardiovascular Research (DZHK), Göttingen, Germany
| | - Raghu Kalluri
- Division of Matrix Biology, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts; Department of Cancer Biology and the Metastasis Research Center, University of Texas MD Anderson Cancer Center, Houston, Texas.
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9
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Han G, Li F, Singh TP, Wolf P, Wang XJ. The pro-inflammatory role of TGFβ1: a paradox? Int J Biol Sci 2012; 8:228-35. [PMID: 22253566 PMCID: PMC3258562 DOI: 10.7150/ijbs.8.228] [Citation(s) in RCA: 99] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2011] [Accepted: 12/14/2011] [Indexed: 01/02/2023] Open
Abstract
TGFβ1 was initially identified as a potent chemotactic cytokine to initiate inflammation, but the autoimmune phenotype seen in TGFβ1 knockout mice reversed the dogma of TGFβ1 being a pro-inflammatory cytokine to predominantly an immune suppressor. The discovery of the role of TGFβ1 in Th17 cell activation once again revealed the pro-inflammatory effect of TGFβ1. We developed K5.TGFβ1 mice with latent human TGFβ1 overexpression targeted to epidermal keratinocytes by keratin 5. These transgenic mice developed significant skin inflammation. Further studies revealed that inflammation severity correlated with switching TGFβ1 transgene expression on and off, and genome wide expression profiling revealed striking similarities between K5.TGFβ1 skin and human psoriasis, a Th1/Th17-associated inflammatory skin disease. Our recent study reveals that treatments alleviating inflammatory skin phenotypes in this mouse model reduced Th17 cells, and antibodies against IL-17 also lessen the inflammatory phenotype. Examination of inflammatory cytokines/chemokines affected by TGFβ1 revealed predominantly Th1-, Th17-related cytokines in K5.TGFβ1 skin. However, the finding that K5.TGFβ1 mice also express Th2-associated inflammatory cytokines under certain pathological conditions raises the possibility that deregulated TGFβ signaling is involved in more than one inflammatory disease. Furthermore, activation of both Th1/Th17 cells and regulatory T cells (Tregs) by TGFβ1 reversely regulated by IL-6 highlights the dual role of TGFβ1 in regulating inflammation, a dynamic, context and organ specific process. This review focuses on the role of TGFβ1 in inflammatory skin diseases.
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Affiliation(s)
- Gangwen Han
- Department of Pathology, University of Colorado Denver, Aurora, CO 80045, USA
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10
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Mantel PY, Schmidt-Weber CB. Transforming growth factor-beta: recent advances on its role in immune tolerance. Methods Mol Biol 2011; 677:303-38. [PMID: 20941619 DOI: 10.1007/978-1-60761-869-0_21] [Citation(s) in RCA: 100] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Transforming growth factor (TGF-β1) is a pleiotropic cytokine, secreted by immune and nonhematopoietic cells. TGF-β is involved in many different critical processes, such as embryonal development, cellular maturation and differentiation, wound healing, and immune regulation. It maintains immune homeostasis by acting as a potent immune suppressor through inhibition of proliferation, differentiation, activation, and effector function of immune cells. Paradoxically, depending on the context, it displays proinflammatory properties by being a potent chemoattractant for neutrophils and promoting inflammation. In addition, it does not only induce differentiation into the anti-inflammatory Treg cells, but also into the proinflammatory Th17 and Th9 cells and inhibits Th22 differentiation. TGF-β has been demonstrated to be involved in multiple pathologies. In infections, it protects against collateral damages caused by the immune system, but it also promotes immune evasion and chronic infections. In autoimmune diseases, a TGF-β dysfunction leads to the loss of tolerance to self-antigens. In cancer, TGF-β is a potent inhibitor of cell proliferation and acts as a tumor suppressor at the beginning of tumorogenesis. However, once the cells become resistant to TGF-β, it mainly supports tumor growth and metastasis by promoting immune evasion and angiogenesis. In asthma, it is assumed to promote allergen tolerance, but plays a detrimental role in irreversible remodeling of the airways. Despite the high numbers of TGF-β-targeted pathways, it is a promising drug target for treatment of autoimmunity, cancer, fibrosis, if cell specificity can be achieved.This review summarizes the progresses that have been accomplished on the understanding of TGF-β's signaling in the immune homeostasis and its role in pathogenesis.
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Affiliation(s)
- Pierre-Yves Mantel
- Department of Immunology and Infectious Diseases, Harvard School of Public Health, Harvard University, Boston, MA, USA.
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Interferon-regulatory factor 4 is essential for the developmental program of T helper 9 cells. Immunity 2010; 33:192-202. [PMID: 20674401 DOI: 10.1016/j.immuni.2010.07.014] [Citation(s) in RCA: 419] [Impact Index Per Article: 29.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2010] [Revised: 05/17/2010] [Accepted: 07/02/2010] [Indexed: 12/14/2022]
Abstract
Interferon-regulatory factor 4 (IRF4) is essential for the development of T helper 2 (Th2) and Th17 cells. Herein, we report that IRF4 is also crucial for the development and function of an interleukin-9 (IL-9)-producing CD4(+) T cell subset designated Th9. IRF4-deficient CD4(+) T cells failed to develop into IL-9-producing Th9 cells, and IRF4-specific siRNA inhibited IL-9 production in wild-type CD4(+) T cells. Chromatin-immunoprecipitation (ChIP) analyses revealed direct IRF4 binding to the Il9 promoter in Th9 cells. In a Th9-dependent asthma model, neutralization of IL-9 substantially ameliorated asthma symptoms. The relevance of these findings is emphasized by the fact that the induction of IL-9 production also occurs in human CD4(+) T cells accompanied by the upregulation of IRF4. Our data clearly demonstrate the central function of IRF4 in the development of Th9 cells and underline the contribution of this T helper cell subset to the pathogenesis of asthma.
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Das J, Ren G, Zhang L, Roberts AI, Zhao X, Bothwell ALM, Van Kaer L, Shi Y, Das G. Transforming growth factor beta is dispensable for the molecular orchestration of Th17 cell differentiation. ACTA ACUST UNITED AC 2009; 206:2407-16. [PMID: 19808254 PMCID: PMC2768861 DOI: 10.1084/jem.20082286] [Citation(s) in RCA: 176] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Interleukin (IL)-17–producing T helper (Th17) cells play a critical role in the pathophysiology of several autoimmune disorders. The differentiation of Th17 cells requires the simultaneous presence of an unusual combination of cytokines: IL-6, a proinflammatory cytokine, and transforming growth factor (TGF) β, an antiinflammatory cytokine. However, the molecular mechanisms by which TGF-β exerts its effects on Th17 cell differentiation remain elusive. We report that TGF-β does not directly promote Th17 cell differentiation but instead acts indirectly by blocking expression of the transcription factors signal transducer and activator of transcription (STAT) 4 and GATA-3, thus preventing Th1 and Th2 cell differentiation. In contrast, TGF-β had no effect on the expression of retinoic acid receptor–related orphan nuclear receptor γt, a Th17-specific transcription factor. Interestingly, in Stat-6−/−T-bet−/− mice, which are unable to generate Th1 and Th2 cells, IL-6 alone was sufficient to induce robust differentiation of Th17 cells, whereas TGF-β had no effect, suggesting that TGF-β is dispensable for Th17 cell development. Consequently, BALB/c Stat-6−/−T-bet−/− mice, but not wild-type BALB/c mice, were highly susceptible to the development of experimental autoimmune encephalomyelitis, which could be blocked by anti–IL-17 antibodies but not by anti–TGF-β antibodies. Collectively, these data provide evidence that TGF-β is not directly required for the molecular orchestration of Th17 cell differentiation.
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Affiliation(s)
- Jyoti Das
- Department of Molecular Genetics, Microbiology, and Immunology, Robert Wood Johnson Medical School-University of Medicine and Dentistry of New Jersey, Piscataway, NJ 08854, USA
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13
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Shen W, Li Y, Zhu J, Schwendener R, Huard J. Interaction between macrophages, TGF-beta1, and the COX-2 pathway during the inflammatory phase of skeletal muscle healing after injury. J Cell Physiol 2007; 214:405-12. [PMID: 17657727 DOI: 10.1002/jcp.21212] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Inflammation, an important phase of skeletal muscle healing, largely involves macrophages, TGF-beta1, and the COX-2 pathway. To improve our understanding of how these molecules interact during all phases of muscle healing, we examined their roles in muscle cells in vitro and in vivo. Initially, we found that depletion of macrophages in muscle tissue led to reduced muscle regeneration. Macrophages may influence healing by inducing the production of TGF-beta1 and PGE2 in different muscle cell types. We then found that the addition of TGF-beta1 induced PGE2 production in muscle cells, an effect probably mediated by COX-2 enzyme. It was also found that TGF-beta1 enhanced macrophage infiltration in wild-type mice after muscle injury. However, this effect was not observed in COX-2(-/-) mice, suggesting that the effect of TGF-beta1 on macrophage infiltration is mediated by the COX-2 pathway. Furthermore, we found that PGE2 can inhibit the expression of TGF-beta1. PGE2 and TGF-beta1 may be involved in a negative feedback loop balancing the level of fibrosis formation during skeletal muscle healing. In conclusion, our results suggest a complex regulatory mechanism of skeletal muscle healing. Macrophages, TGF-beta1, and the COX-2 pathway products may regulate one another's levels and have profound influence on the whole muscle healing process.
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Affiliation(s)
- Wei Shen
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
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14
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Levéen P, Carlsén M, Makowska A, Oddsson S, Larsson J, Goumans MJ, Cilio CM, Karlsson S. TGF-β type II receptor–deficient thymocytes develop normally but demonstrate increased CD8+ proliferation in vivo. Blood 2005; 106:4234-40. [PMID: 16131565 DOI: 10.1182/blood-2005-05-1871] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
We have taken advantage of the Cre/lox system to generate a mouse model with inducible deficiency of transforming growth factor β receptor II (TβRII). Using this approach, transforming growth factor β (TGF-β) signaling deficiency can be restricted to the hematopoietic system by bone marrow transplantation. Mice that received transplants with TβRII-/- bone marrow develop a lethal inflammatory disorder closely resembling that of TGF-β1-null mice. Previous in vitro studies have suggested multiple roles for TGF-β in T-cell development, including proliferation, apoptosis, and differentiation. We used our transplantation model to ask whether T-cell development is normal in the absence of TGF-β signaling. The findings show for the first time in vivo and in fetal thymus organ culture (FTOC) that TGF-β is not required for thymocytes to differentiate along the entire pathway of thymic T-cell development, as defined by the expression patterns of CD4, CD8, CD25, and CD44. In contrast to previous investigations, no increase of thymocyte apoptosis was observed. However, TβRII-deficient CD8+ thymocytes displayed a 2-fold increase in proliferation rate, as determined by bromodeoxyuridine (BrdU) incorporation in vivo. These results reinforce the importance of TGF-β as an immune regulator critical for T-cell function.
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Affiliation(s)
- Per Levéen
- Molecular Medicine and Gene Therapy, Institute of Laboratory Medicine and The Lund Strategic Research Center for Stem Cell Biology and Cell Therapy, Lund University, Sweden
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15
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Idiopathic Pulmonary Fibrosis. Proceedings of the 1st Annual Pittsburgh International Lung Conference. October 2002. Am J Respir Cell Mol Biol 2003; 29:S1-105. [PMID: 12936907 DOI: 10.1165/rcmb.2003-0159su] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
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16
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Abstract
Current animal models of human myositis include spontaneous, induced, and transgenic models. Although it is clear that none of these models possesses all the features of the human diseases, they may provide insight into the pathophysiologic mechanisms, and possibly the therapy, of inflammatory muscle disease. Because the human IIMs are phenotypically heterogeneous, but may be divided into more homogeneous subgroups based upon clinical or serologic features, it is possible that different pathogeneses are involved in different subgroups. It is unlikely that any single model would reproduce all features of the human disease. It may be possible, however, to gain insight into some subgroups of the human disease if certain animal models faithfully reproduce one or more subtypes or aspects of the IIMs. Because immunogenetic risk factors, and exposure to certain environmental agents important in triggering myositis in genetically susceptible persons, may be necessary components for human disease induction, transgenic approaches to humanizing murine immune systems and a better understanding of environmental risk factors will be productive avenues for future research. Additional investigations into the molecular basis of the human myositis syndromes and the pathogenesis of the spontaneous, induced, and transgenic animal models should ultimately allow for better understanding and therapy of these diseases.
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Affiliation(s)
- Kanneboyina Nagaraju
- Division of Rheumatology, Department of Medicine, Ross 1042, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
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17
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Levéen P, Larsson J, Ehinger M, Cilio CM, Sundler M, Sjöstrand LJ, Holmdahl R, Karlsson S. Induced disruption of the transforming growth factor beta type II receptor gene in mice causes a lethal inflammatory disorder that is transplantable. Blood 2002; 100:560-8. [PMID: 12091349 DOI: 10.1182/blood.v100.2.560] [Citation(s) in RCA: 193] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Recent studies in mouse models deficient in transforming growth factor beta (TGF-beta) signaling have documented TGF-beta as one of the major regulators of immune function. TGF-beta1-null animals demonstrated massive autoimmune inflammation affecting multiple organs, but attempts to transfer the phenotype to normal animals by bone marrow transplantation only resulted in minor inflammatory lesions. We wanted to ask whether a lethal inflammatory phenotype would develop following transplantation of bone marrow deficient for the TGF-beta type II receptor (TbetaRII) gene to normal recipient animals. The TbetaRII-null mutation would generate a cell autonomous phenotype that cannot be reverted by the influence of endocrine or paracrine TGF-beta derived from the recipient animal. We have generated conditional knockout mice in which the TbetaRII gene is disrupted upon induction with interferon-alphabeta or polyI:polyC. We show that induction of TbetaRII gene disruption in these mice by polyI:polyC results in a lethal inflammatory disease. Importantly, bone marrow from conditional knockout mice transferred to normal recipent mice caused a similar lethal inflammation, regardless of whether induction of TGF-beta receptor deficiency occurred in donor animals before, or in recipient animals after transplantation. These results show that TGF-beta signaling deficiency within cells of hematopoietic origin is sufficient to cause a lethal inflammatory disorder in mice. This animal model provides an important tool to further clarify the pathogenic mechanisms in animals deficient for TGF-beta signaling and the importance of TGF-beta to regulate immune functions.
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Affiliation(s)
- Per Levéen
- Department of Molecular Medicine and Gene Therapy, Lund University, Sweden
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18
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Guo M, Mathieu PA, Linebaugh B, Sloane BF, Reiners JJ. Phorbol ester activation of a proteolytic cascade capable of activating latent transforming growth factor-betaL a process initiated by the exocytosis of cathepsin B. J Biol Chem 2002; 277:14829-37. [PMID: 11815600 DOI: 10.1074/jbc.m108180200] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
12-O-Tetradecanoylphorbol-13-acetate (TPA) suppresses the proliferation of the human breast epithelial cell line MCF10A-Neo by initiating proteolytic processes that activate latent transforming growth factor (TGF)-beta in the serum used to supplement culture medium. Within 1 h of treatment, cultures accumulated an extracellular activity capable of cleaving a substrate for urokinase-type plasminogen activator (uPA) and tissue plasminogen activator (tPA). This activity was inhibited by plasminogen activator inhibitor-1 or antibodies to uPA but not tPA. Pro-uPA activation was preceded by dramatic changes in lysosome trafficking and the extracellular appearance of cathepsin B and beta-hexosaminidase but not cathepsins D or L. Co-treatment of cultures with the cathepsin B inhibitors CA-074 or Z-FA-FMK suppressed the cytostatic effects of TPA and activation of pro-uPA. In the absence of TPA, exogenously added cathepsin B activated pro-uPA and suppressed MCF10A-Neo proliferation. The cytostatic effects of both TPA and cathepsin B were suppressed in cells cultured in medium depleted of plasminogen/plasmin or supplemented with neutralizing TGF-beta antibody. Pretreatment with cycloheximide did not suppress the exocytosis of cathepsin B or the activation of pro-uPA. Hence, TPA activates signaling processes that trigger the exocytosis of a subpopulation of lysosomes/endosomes containing cathepsin B. Subsequently, extracellular cathepsin B initiates a proteolytic cascade involving uPA, plasminogen, and plasmin that activates serum-derived latent TGF-beta.
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Affiliation(s)
- Meng Guo
- Institute of Environmental Health Sciences, Wayne State University and the Department of Pharmacology, Wayne State University School of Medicine, Detroit, Michigan 48201, USA
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19
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Grande JP, Warner GM, Walker HJ, Yusufi ANK, Cheng J, Gray CE, Kopp JB, Nath KA. TGF-beta1 is an autocrine mediator of renal tubular epithelial cell growth and collagen IV production. Exp Biol Med (Maywood) 2002; 227:171-81. [PMID: 11856815 DOI: 10.1177/153537020222700304] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Recent studies in cultured cells have provided evidence that a variety of pathobiologic stimuli, including high glucose, angiotensin II, and thromboxane A(2), trigger a signaling pathway leading to autocrine induction of TGF-beta1. TGF-beta1 production through this pathway may profoundly affect cell growth, matrix synthesis, and response to injury. This study examines the role of autocrine versus exogenously added TGF-beta1 in cellular proliferation and collagen IV production, critical targets of TGF-beta1 signaling, using renal cells derived from TGF-beta1 knockout (KO) animals or wild-type (WT) controls. Growth of WT and KO cells was assessed by cell counting and [(3)H]thymidine uptake. Basal and TGF-beta1-stimulated collagen production was assessed by Northern and Western blotting; transcriptional activity of the alpha1(IV) collagen gene was assessed by transient transfection analysis. KO cells grew at a faster rate than WT cells carefully matched for plating density and passage number. This increased growth rate was paralleled by increases in [(3)H]thymidine uptake. KO cells expressed lower levels of the cell cycle inhibitors p21 and p27 than WT cells. KO cells failed to express TGF-beta1, as expected. Basal TGF-beta3 mRNA levels were higher in KO cells than in WT cells. WT cells expressed higher basal levels of TGF-beta2 mRNA than KO cells. Basal alpha1(IV) and alpha2(IV) collagen mRNA and protein expression were significantly lower in KO cells than WT cells. Administration of exogenous TGF-beta1 induced collagen IV production in both KO and WT cells. Although basal transcriptional activity of an alpha1(IV) collagen-CAT construct was lower in KO cells than WT cells, administration of exogenous TGF-beta1 was associated with significant increases in transcriptional activity of this construct in both KO and WT cells. These studies provide evidence that autocrine production of TGF-beta1 may play a critical role in regulation of growth and basal collagen IV production by renal tubular epithelial cells.
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Affiliation(s)
- Joseph P Grande
- Renal Pathophysiology Laboratory, Department of Laboratory Medicine and Pathology, and Division of Nephrology, Department of Internal Medicine, Mayo Clinic, Rochester, Minnesota 55905, USA.
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20
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Bousquet J, Van Cauwenberge P, Khaltaev N. Allergic rhinitis and its impact on asthma. J Allergy Clin Immunol 2001; 108:S147-334. [PMID: 11707753 DOI: 10.1067/mai.2001.118891] [Citation(s) in RCA: 2094] [Impact Index Per Article: 91.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- J Bousquet
- Department of Allergy and Respiratory Diseases, University Hospital and INSERM, Montpellier, France
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21
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DenBesten PK, Machule D, Gallagher R, Marshall GW, Mathews C, Filvaroff E. The effect of TGF-beta 2 on dentin apposition and hardness in transgenic mice. Adv Dent Res 2001; 15:39-41. [PMID: 12640737 DOI: 10.1177/08959374010150010901] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Transforming growth factor beta, TGF-beta, is expressed during tooth formation and can induce pre-odontoblast differentiation and formation of functional odontoblast-like cells in vitro. In addition, exogenous TGF-beta can increase reparative dentin formation, presumably by acting on odontoblasts. In this study, we examined the tooth phenotype of transgenic mice, in which TGF-beta 2 expression is directed by the osteocalcin promoter. Previous studies have shown that these mice have a bone phenotype that resembles that of human osteoporosis, including the existence of spontaneous fractures. Microhardness testing of the enamel and dentin showed no differences in the molars of these transgenic mice as compared with those of their wild-type littermates. Consistent with the increase in bone mineral apposition rate previously reported in these mice, the dentin apposition rate appeared to be increased in the TGF-beta 2-overexpressing mice. Thus, in teeth, as in bone, TGF-beta 2 appears to stimulate the synthesis and deposition of matrix. Further studies are needed to understand the effect of TGF-beta 2 on distinct mineralized tissues (bone, dentin, and cementum) and to determine whether exogenous TGF-beta 2 may be useful for tooth repair.
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Affiliation(s)
- P K DenBesten
- Department of Growth and Development, Box 0640, University of California, San Francisco, CA 94143-0640, USA.
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22
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Rosendahl A, Checchin D, Fehniger TE, ten Dijke P, Heldin CH, Sideras P. Activation of the TGF-beta/activin-Smad2 pathway during allergic airway inflammation. Am J Respir Cell Mol Biol 2001; 25:60-8. [PMID: 11472976 DOI: 10.1165/ajrcmb.25.1.4396] [Citation(s) in RCA: 102] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Changes in the levels of transforming growth factor (TGF)-beta cytokines or receptors observed during the progression of several inflammatory and fibrotic disorders have been used to implicate these cytokines in the pathophysiology of these diseases. Although correlative, these studies were inconclusive because they were unable to demonstrate actual continuous TGF-beta-mediated signaling in the involved tissues. We reasoned that the phosphorylation state and subcellular localization of Smad2, the intracellular effector of TGF-beta/activin-mediated signaling, could be used as a marker of active signaling mediated by these cytokines in situ. We therefore used an experimental model of ovalbumin-induced allergic airway inflammation and were able to demonstrate a dramatic increase in the numbers of bronchial epithelial, alveolar, and infiltrating inflammatory cells expressing nuclear phosphorylated Smad2 within the allergen-challenged lungs. This was accompanied by strong upregulation of the activin receptor ALK-4/ActR-IB and redistribution of the TGF-beta responsive ALK-5/TbetaR-I. Although levels of TGF-beta1, TGF-beta2, and TGF-beta3 messenger RNA (mRNA) were marginally altered, the level of activin mRNA was strongly upregulated during the inflammatory response. Our data illustrate the usefulness of antiphosphorylated Smad antibodies in demonstrating active TGF- beta/activin-mediated signaling in vivo and strongly suggest that activin/Smad-mediated signaling could be a critical contributor in the pathophysiology of allergic pulmonary diseases.
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Affiliation(s)
- A Rosendahl
- Department of Molecular Sciences and Biosciences, AstraZeneca R&D Lund, Scheelevägen 2, S-221 87 Lund, Sweden.
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23
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Abstract
One of the major obstacles in tumor-immunology is the outgrowth of malignant tumors despite their immunogenicity and recognition by the immune-system. Multiple mechanisms for this phenomenon have been proposed. We review the possible involvement of transforming growth factor beta (TGF-beta) in this context. TGF-beta is a cytokine with pleiotropic functions, involved in multiple physiologic processes including immunoregulation. Immune elimination of most cancers ultimately depends on cytolytic T cells (CTL). We propose a mechanism of specific suppression of cytolytic T cell (CTL)-responses mediated through immunoglobulin-bound TGF-beta (IgG-TGF-beta), secreted by activated B cells, and a cell of myeloid origin. This mononuclear "Veto" cell presumably binds IgG-TGF-beta through Fc-receptors and activates latent TGF-beta. The suggestion that B cell responses can inhibit tumor rejection is supported by observations in B cell-deficient mice. Ways for enhancing effective cancer immunity by interfering with the network of interactions involving IgG-TGF-beta are discussed.
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Affiliation(s)
- C Beck
- Immunology Division, Department of Pathology, University of Chicago, Chicago, Illinois 60637, USA.
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24
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Abstract
Transforming growth factor (TGF-beta) is a multifunctional polypeptide implicated in the regulation of a variety of cellular processes including growth, differentiation, apoptosis, adhesion, and motility. Abnormal activation or inhibition of these TGF-beta regulated processes is implicated in many diseases, including cancer. Cancers can develop through selective exploitation of defects in TGF-beta signaling that occur at several different levels in the pathway. The TGF-beta signal transduction cascade is initiated when TGF-beta binds to transmembrane receptors. The TGF-beta receptors then phosphorylate and activate Smad proteins, which transduce the signal from the cytoplasm to the nucleus. In the nucleus, Smads can bind directly to DNA and cooperate with other transcription factors to induce transcription of TGF-beta target genes. Mutations in target genes, Smads, or the TGF-beta receptor are associated with certain human cancers.
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Affiliation(s)
- J Rich
- Division of Neurology, Duke University Medical Center, Durham, North Carolina 27710, USA
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25
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Friedman SL, Maher JJ, Bissell DM. Mechanisms and therapy of hepatic fibrosis: report of the AASLD Single Topic Basic Research Conference. Hepatology 2000; 32:1403-8. [PMID: 11093750 DOI: 10.1053/jhep.2000.20243] [Citation(s) in RCA: 114] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- S L Friedman
- Division of Liver Diseases and Dept of Medicine, Mount Sinai School of Medicine, New York, NY 10029, USA.
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26
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Abstract
The field of transforming growth factor-beta (TGF-beta) signaling sees periodic discoveries that revolutionize our thinking, redirect our experiments, and peak our excitement. One of the first such discoveries was less than a decade ago: the molecular cloning of the type I and type II TGF-beta receptors. This breakthrough defined a novel family of serine/threonine kinase receptors, which led to the description of an ever-expanding superfamily. The discovery of how these receptors are grouped on the cell surface, bind TGF-beta and are activated by specific phosphorylation events further defined the uniqueness of this system in comparison to other families of growth factor receptors. Now, once again, the TGF-beta field has been revolutionized. This time, the discovery is the Smad family of proteins. Although one can hardly imagine TGF-beta without the Smads, the cloning of the Smads and their implication in TGF-beta signaling was only four years ago. Since that time, great advances have been made in our understanding of the Smads as transcription factors, which are activated by receptor mediated phosphorylation. In addition, animal models for a loss of Smad function have provided insight into the role of specific Smads in a variety of physiologic systems. The Smad field has been growing exponentially. A comprehensive review of all aspects of the Smads, therefore, would be beyond the scope of a single review. Instead, this review highlights some of the general aspects of Smad function, and then focuses on the role of specific Smad family members in transcriptional regulation, animal physiology, and disease processes.
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Affiliation(s)
- M Datto
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham 27710, USA
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27
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Datto MB, Frederick JP, Pan L, Borton AJ, Zhuang Y, Wang XF. Targeted disruption of Smad3 reveals an essential role in transforming growth factor beta-mediated signal transduction. Mol Cell Biol 1999; 19:2495-504. [PMID: 10082515 PMCID: PMC84042 DOI: 10.1128/mcb.19.4.2495] [Citation(s) in RCA: 398] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/1998] [Accepted: 12/22/1998] [Indexed: 11/20/2022] Open
Abstract
The Smads are a family of nine related proteins which function as signaling intermediates for the transforming growth factor beta (TGF-beta) superfamily of ligands. To discern the in vivo functions of one of these Smads, Smad3, we generated mice harboring a targeted disruption of this gene. Smad3 null mice, although smaller than wild-type littermates, are viable, survive to adulthood, and exhibit an early phenotype of forelimb malformation. To study the cellular functions of Smad3, we generated Smad3 null mouse embryonic fibroblasts (MEFs) and dermal fibroblasts. We demonstrate that null MEFs have lost the ability to form Smad-containing DNA binding complexes and are unable to induce transcription from the TGF-beta-responsive promoter construct, p3TP-lux. Using the primary dermal fibroblasts, we also demonstrate that Smad3 is integral for induction of endogenous plasminogen activator inhibitor 1. We subsequently demonstrate that Smad3 null MEFs are partially resistant to TGF-beta's antiproliferative effect, thus firmly establishing a role for Smad3 in TGF-beta-mediated growth inhibition. We next examined cells in which Smad3 is most highly expressed, specifically cells of immune origin. Although no specific developmental defect was detected in the immune system of the Smad3 null mice, a functional defect was observed in the ability of TGF-beta to inhibit the proliferation of splenocytes activated by specific stimuli. In addition, primary splenocytes display defects in TGF-beta-mediated repression of cytokine production. These data, taken together, establish a role for Smad3 in mediating the antiproliferative effects of TGF-beta and implicate Smad3 as a potential effector for TGF-beta in modulating immune system function.
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Affiliation(s)
- M B Datto
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, North Carolina 27710, USA
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28
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Hutchinson IV. An endothelin-transforming growth factor beta pathway in the nephrotoxicity of immunosuppressive drugs. Curr Opin Nephrol Hypertens 1998; 7:665-71. [PMID: 9864663 DOI: 10.1097/00041552-199811000-00007] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
An endothelin-transforming growth factor beta type 1 pathway is proposed to account for cyclosporin nephrotoxicity. Cyclosporin amplifies the production of endothelin. Enhanced endothelin production accentuates acute vascular events and promotes the synthesis and activation of transforming growth factor beta type 1, contributing to acute and chronic pathology. This scheme integrates many observations, including the involvement of the renin-angiotensin pathway and other activators of endothelin production, and provides a rationale for the amelioration of cyclosporin nephrotoxicity.
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Affiliation(s)
- I V Hutchinson
- School of Biological Sciences, University of Manchester, UK
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