title: Pharmacologic inhibition of lactate production prevents myofibroblast differentiation.
abstract: Myofibroblasts are one of the primary cell types responsible for the accumulation of extracellular matrix in fibrosing diseases, and targeting myofibroblast differentiation is an important therapeutic strategy for the treatment of pulmonary fibrosis. Transforming growth factor-β (TGF-β) has been shown to be an important inducer of myofibroblast differentiation. We previously demonstrated that lactate dehydrogenase and its metabolic product lactic acid are important mediators of myofibroblast differentiation, via acid-induced activation of latent TGF-β. Here we explore whether pharmacologic inhibition of LDH activity can prevent TGF-β-induced myofibroblast differentiation. Primary human lung fibroblasts from healthy patients and those with pulmonary fibrosis were treated with TGF-β and or gossypol, an LDH inhibitor. Protein and RNA were analyzed for markers of myofibroblast differentiation and extracellular matrix generation. Gossypol inhibited TGF-β-induced expression of the myofibroblast marker α-smooth muscle actin (α-SMA) in a dose-dependent manner in both healthy and fibrotic human lung fibroblasts. Gossypol also inhibited expression of collagen 1, collagen 3, and fibronectin. Gossypol inhibited LDH activity, the generation of extracellular lactic acid, and the rate of extracellular acidification in a dose-dependent manner. Furthermore, gossypol inhibited TGF-β bioactivity in a dose-dependent manner. Concurrent treatment with an LDH siRNA increased the ability of gossypol to inhibit TGF-β-induced myofibroblast differentiation. Gossypol inhibits TGF-β-induced myofibroblast differentiation through inhibition of LDH, inhibition of extracellular accumulation of lactic acid, and inhibition of TGF-β bioactivity. These data support the hypothesis that pharmacologic inhibition of LDH may play an important role in the treatment of pulmonary fibrosis.
authors.affiliation: University of Rochester Department of Medicine, Rochester, New York; University of Rochester Lung Biology and Disease Program, Rochester, New York.
authors.forename: Robert Matthew
authors.initials: RM
authors.lastname: Kottmann
authors.affiliation: University of Rochester Department of Medicine, Rochester, New York; University of Rochester Lung Biology and Disease Program, Rochester, New York.
authors.forename: Emma
authors.initials: E
authors.lastname: Trawick
authors.affiliation: University of Rochester Department of Medicine, Rochester, New York; University of Rochester Lung Biology and Disease Program, Rochester, New York.
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: Judge
authors.affiliation: University of Rochester Department of Medicine, Rochester, New York;
authors.forename: Lindsay A
authors.initials: LA
authors.lastname: Wahl
authors.affiliation: University of Rochester Department of Medicine, Rochester, New York; University of Rochester Lung Biology and Disease Program, Rochester, New York.
authors.forename: Amali P
authors.initials: AP
authors.lastname: Epa
authors.affiliation: University of Rochester Department of Medicine, Rochester, New York; University of Rochester Lung Biology and Disease Program, Rochester, New York.
authors.forename: Kristina M
authors.initials: KM
authors.lastname: Owens
authors.forename: Thomas H
authors.identifier: http://orcid.org/0000-0001-7177-3041
authors.initials: TH
authors.lastname: Thatcher
authors.affiliation: University of Rochester Department of Medicine, Rochester, New York; University of Rochester Department of Environmental Medicine, Rochester, New York; and University of Rochester Lung Biology and Disease Program, Rochester, New York.
authors.forename: Richard P
authors.initials: RP
authors.lastname: Phipps
authors.affiliation: University of Rochester Department of Medicine, Rochester, New York; University of Rochester Department of Environmental Medicine, Rochester, New York; and University of Rochester Lung Biology and Disease Program, Rochester, New York patricia_sime@urmc.rochester.edu.
authors.forename: Patricia J
authors.initials: PJ
authors.lastname: Sime
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000187:drug effects*; D002460:Cell Line; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005109:Extracellular Matrix / Q000187:drug effects / Q000378:metabolism; D055785:Gene Knockdown Techniques; D006072:Gossypol / Q000494:pharmacology; D006801:Humans; D007770:L-Lactate Dehydrogenase / Q000037:antagonists & inhibitors / Q000378:metabolism; D019344:Lactic Acid / Q000096:biosynthesis*; D008168:Lung / Q000473:pathology; D008907:Mink; D058628:Myofibroblasts / Q000166:cytology* / Q000187:drug effects* / Q000378:metabolism; D011658:Pulmonary Fibrosis / Q000473:pathology; D014019:Tissue Donors; D016212:Transforming Growth Factor beta / Q000494:pharmacology
chemical_list: D004791:Enzyme Inhibitors; D016212:Transforming Growth Factor beta; D019344:Lactic Acid; D007770:L-Lactate Dehydrogenase; D006072:Gossypol
keywords: LDH; gossypol; lactate; myofibroblast; pulmonary fibrosis