1
|
Judge JL, Owens KM, Pollock SJ, Woeller CF, Thatcher TH, Williams JP, Phipps RP, Sime PJ, Kottmann RM. Ionizing radiation induces myofibroblast differentiation via lactate dehydrogenase. Am J Physiol Lung Cell Mol Physiol 2015; 309:L879-87. [PMID: 26254422 DOI: 10.1152/ajplung.00153.2015] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2015] [Accepted: 08/04/2015] [Indexed: 12/13/2022] Open
Abstract
Pulmonary fibrosis is a common and dose-limiting side-effect of ionizing radiation used to treat cancers of the thoracic region. Few effective therapies are available for this disease. Pulmonary fibrosis is characterized by an accumulation of myofibroblasts and excess deposition of extracellular matrix proteins. Although prior studies have reported that ionizing radiation induces fibroblast to myofibroblast differentiation and collagen production, the mechanism remains unclear. Transforming growth factor-β (TGF-β) is a key profibrotic cytokine that drives myofibroblast differentiation and extracellular matrix production. However, its activation and precise role in radiation-induced fibrosis are poorly understood. Recently, we reported that lactate activates latent TGF-β through a pH-dependent mechanism. Here, we wanted to test the hypothesis that ionizing radiation leads to excessive lactate production via expression of the enzyme lactate dehydrogenase-A (LDHA) to promote myofibroblast differentiation. We found that LDHA expression is increased in human and animal lung tissue exposed to ionizing radiation. We demonstrate that ionizing radiation induces LDHA, lactate production, and extracellular acidification in primary human lung fibroblasts in a dose-dependent manner. We also demonstrate that genetic and pharmacologic inhibition of LDHA protects against radiation-induced myofibroblast differentiation. Furthermore, LDHA inhibition protects from radiation-induced activation of TGF-β. We propose a profibrotic feed forward loop, in which radiation induces LDHA expression and lactate production, which can lead to further activation of TGF-β to drive the fibrotic process. These studies support the concept of LDHA as an important therapeutic target in radiation-induced pulmonary fibrosis.
Collapse
Affiliation(s)
- J L Judge
- Department of Environmental Medicine, University of Rochester, Rochester, New York; Lung Biology and Disease Program, University of Rochester, Rochester, New York
| | - K M Owens
- Department of Medicine, Pulmonary and Critical Care Medicine, University of Rochester, Rochester, New York; and
| | - S J Pollock
- Department of Environmental Medicine, University of Rochester, Rochester, New York
| | - C F Woeller
- Department of Environmental Medicine, University of Rochester, Rochester, New York
| | - T H Thatcher
- Department of Medicine, Pulmonary and Critical Care Medicine, University of Rochester, Rochester, New York; and Lung Biology and Disease Program, University of Rochester, Rochester, New York
| | - J P Williams
- Department of Environmental Medicine, University of Rochester, Rochester, New York
| | - R P Phipps
- Department of Environmental Medicine, University of Rochester, Rochester, New York; Department of Medicine, Pulmonary and Critical Care Medicine, University of Rochester, Rochester, New York; and Lung Biology and Disease Program, University of Rochester, Rochester, New York
| | - P J Sime
- Department of Environmental Medicine, University of Rochester, Rochester, New York; Department of Medicine, Pulmonary and Critical Care Medicine, University of Rochester, Rochester, New York; and Lung Biology and Disease Program, University of Rochester, Rochester, New York
| | - R M Kottmann
- Department of Medicine, Pulmonary and Critical Care Medicine, University of Rochester, Rochester, New York; and Lung Biology and Disease Program, University of Rochester, Rochester, New York
| |
Collapse
|
2
|
Kuriyan AE, Lehmann GM, Kulkarni AA, Woeller CF, Feldon SE, Hindman HB, Sime PJ, Huxlin KR, Phipps RP. Electrophilic PPARγ ligands inhibit corneal fibroblast to myofibroblast differentiation in vitro: a potentially novel therapy for corneal scarring. Exp Eye Res 2011; 94:136-45. [PMID: 22178289 DOI: 10.1016/j.exer.2011.11.018] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2011] [Revised: 10/21/2011] [Accepted: 11/27/2011] [Indexed: 12/31/2022]
Abstract
A critical component of corneal scarring is the TGFβ-induced differentiation of corneal keratocytes into myofibroblasts. Inhibitors of this differentiation are potentially therapeutic for corneal scarring. In this study, we tested the relative effectiveness and mechanisms of action of two electrophilic peroxisome proliferator-activated receptor gamma (PPARγ) ligands: cyano-3,12-dioxolean-1,9-dien-28-oic acid-methyl ester (CDDO-Me) and 15-deoxy-Δ(-12,14)-prostaglandin J(2) (15d-PGJ(2)) for inhibiting TGFβ-induced myofibroblast differentiation in vitro. TGFβ was used to induce myofibroblast differentiation in cultured, primary human corneal fibroblasts. CDDO-Me and 15d-PGJ(2) were added to cultures to test their ability to inhibit this process. Myofibroblast differentiation was assessed by measuring the expression of myofibroblast-specific proteins (αSMA, collagen I, and fibronectin) and mRNA (αSMA and collagen III). The role of PPARγ in the inhibition of myofibroblast differentiation by these agents was tested in genetically and pharmacologically manipulated cells. Finally, we assayed the importance of electrophilicity in the actions of these agents on TGFβ-induced αSMA expression via Western blotting and immunofluorescence. Both electrophilic PPARγ ligands (CDDO-Me and 15d-PGJ(2)) potently inhibited TGFβ-induced myofibroblast differentiation, but PPARγ was only partially required for inhibition of myofibroblast differentiation by either agent. Electrophilic PPARγ ligands were able to inhibit myofibroblast differentiation more potently than non-electrophilic PPARγ ligands, suggesting an important role of electrophilicity in this process. CDDO-Me and 15d-PGJ(2) are strong inhibitors of TGFβ-induced corneal fibroblast to myofibroblast differentiation in vitro, suggesting this class of agents as potential novel therapies for corneal scarring warranting further study in pre-clinical animal models.
Collapse
Affiliation(s)
- A E Kuriyan
- University of Rochester School of Medicine and Dentistry, University of Rochester, Rochester, NY, United States
| | | | | | | | | | | | | | | | | |
Collapse
|
3
|
Simpson-Haidaris PJ, Pollock SJ, Ramon S, Guo N, Woeller CF, Feldon SE, Phipps RP. Anticancer Role of PPARgamma Agonists in Hematological Malignancies Found in the Vasculature, Marrow, and Eyes. PPAR Res 2010; 2010:814609. [PMID: 20204067 PMCID: PMC2829627 DOI: 10.1155/2010/814609] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2009] [Revised: 11/30/2009] [Accepted: 12/16/2009] [Indexed: 12/19/2022] Open
Abstract
The use of targeted cancer therapies in combination with conventional chemotherapeutic agents and/or radiation treatment has increased overall survival of cancer patients. However, longer survival is accompanied by increased incidence of comorbidities due, in part, to drug side effects and toxicities. It is well accepted that inflammation and tumorigenesis are linked. Because peroxisome proliferator-activated receptor (PPAR)-gamma agonists are potent mediators of anti-inflammatory responses, it was a logical extension to examine the role of PPARgamma agonists in the treatment and prevention of cancer. This paper has two objectives: first to highlight the potential uses for PPARgamma agonists in anticancer therapy with special emphasis on their role when used as adjuvant or combined therapy in the treatment of hematological malignancies found in the vasculature, marrow, and eyes, and second, to review the potential role PPARgamma and/or its ligands may have in modulating cancer-associated angiogenesis and tumor-stromal microenvironment crosstalk in bone marrow.
Collapse
Affiliation(s)
- P. J. Simpson-Haidaris
- Department of Medicine/Hem-Onc Division, School of Medicine and Dentistry, University of Rochester, Rochester, NY 14642, USA
- Department of Microbiology and Immunology, School of Medicine and Dentistry, University of Rochester, Rochester, NY 14642, USA
- Department of Pathology and Laboratory Medicine, School of Medicine and Dentistry, University of Rochester, Rochester, NY 14642, USA
| | - S. J. Pollock
- Department of Environmental Medicine, School of Medicine and Dentistry, University of Rochester, Rochester, NY 14642, USA
| | - S. Ramon
- Department of Microbiology and Immunology, School of Medicine and Dentistry, University of Rochester, Rochester, NY 14642, USA
| | - N. Guo
- Department of Opthalmology, School of Medicine and Dentistry, University of Rochester, Rochester, NY 14642, USA
| | - C. F. Woeller
- Department of Environmental Medicine, School of Medicine and Dentistry, University of Rochester, Rochester, NY 14642, USA
| | - S. E. Feldon
- Department of Opthalmology, School of Medicine and Dentistry, University of Rochester, Rochester, NY 14642, USA
| | - R. P. Phipps
- Department of Environmental Medicine, School of Medicine and Dentistry, University of Rochester, Rochester, NY 14642, USA
- Department of Opthalmology, School of Medicine and Dentistry, University of Rochester, Rochester, NY 14642, USA
- The Lung Biology and Disease Program, School of Medicine and Dentistry, University of Rochester, Rochester, NY 14642, USA
| |
Collapse
|