Glycogen Synthase Kinase-3\u03b2 Inhibition with 9-ING-41 Attenuates the Progression of Pulmonary Fibrosis

Ann Jeffers,Steven Idell,Daniel M. Schmitt,Francis J. Giles,Kathleen B. Koenig,Satoshi Komatsu,Wenyi Qin,Shuzi Owens,Torry A. Tucker

doi:10.1038/s41598-019-55176-w

Abstract

Idiopathic pulmonary fibrosis (IPF) is a progressive interstitial lung disease with a median survival of 3 years after diagnosis. Although the etiology of IPF is unknown, it is characterized by extensive alveolar epithelial cell apoptosis and proliferation of myofibroblasts in the lungs. While the origins of these myofibroblast appear to be diverse, fibroblast differentiation contributes to expansion of myofibroblasts and to disease progression. We found that agents that contribute to neomatrix formation and remodeling in pulmonary fibrosis (PF); TGF-β, Factor Xa, thrombin, plasmin and uPA all induced fibroblast/myofibroblast differentiation. These same mediators enhanced GSK-3β activation via phosphorylation of tyrosine-216 (p-Y216). Inhibition of GSK-3β signaling with the novel inhibitor 9-ING-41 blocked the induction of myofibroblast markers; α-SMA and Col-1 and reduced morphological changes of myofibroblast differentiation. In in vivo studies, the progression of TGF-β and bleomycin mediated PF was significantly attenuated by 9-ING-41 administered at 7 and 14 days respectively after the establishment of injury. Specifically, 9-ING-41 treatment significantly improved lung function (compliance and lung volumes; p < 0.05) of TGF-β adenovirus treated mice compared to controls. Similar results were found in mice with bleomycin-induced PF. These studies clearly show that activation of the GSK-3β signaling pathway is critical for the induction of myofibroblast differentiation in lung fibroblasts ex vivo and pulmonary fibrosis in vivo. The results offer a strong premise supporting the continued investigation of the GSK-3β signaling pathway in the control of fibroblast-myofibroblast differentiation and fibrosing lung injury. These data provide a strong rationale for extension of clinical trials of 9-ING-41 to patients with IPF.

Highlights

Chronic infiltration by and proliferation of myofibroblasts result in progressive pulmonary fibrosis (PF)
GSK-3β had been shown to be important in the treatment of some cancers and the pathogenesis of fibrosis in other organs[13,14,15,16,23,24,42,43], its role in myofibroblast differentiation and the progression of PF has remained unclear until the present time
We show that GSK-3β activation is critical for fibroblast to myofibroblast differentiation

Summary

Introduction

Chronic infiltration by and proliferation of myofibroblasts result in progressive PF These cells express increased amounts of α-SMA and promote the accumulation of matrix proteins, including collagen, that contribute to fibrotic remodeling. This damage eventually culminates in destruction of alveolar architecture in IPF with formation of fibrotic foci and respiratory compromise with impaired gas exchange. While some studies have reported that inhibition of GSK-3β promotes myofibroblast differentiation and increased expression of mesenchymal markers, others show that GSK-3β inhibition blocks fibroblast activation and reduces indices of lung injury[5,13,16,23,24,25,26,27,28]. We provide evidence that GSK-3β regulates differentiation of lung myofibroblasts, that inhibition of the process can be achieved by 9-ING-41 and that administration of this inhibitor is well-tolerated and effectively blocks PF in two murine preclinical PF models

Methods

Results

Conclusion