ECM Stiffness Regulates Lung Fibroblast Survival Through RasGRF1-dependent Signaling

Overview

Journal J Biol Chem

Date 2025 Jan 10

PMID 39793891

Authors

Elizabeth Monaghan-Benson

Julien Aureille

Christophe Guilluy

Affiliations

Soon will be listed here.

Abstract

Extracellular matrix stiffness is one of the multiple mechanical signals that alter cellular behavior. During studies exploring the effect of matrix rigidity on lung fibroblast survival, we discovered that enhanced survival on stiff substrates is dependent on elevated Ras activity, owing to the activation of the guanine nucleotide exchange factor, RasGRF1. Mechanistically, we found that the increased Ras activity lead to the activation of both the AKT and ERK pathways. Pharmacological inhibition of AKT or ERK signaling attenuates the elevated survival observed on stiff substrates. AKT signaling regulates the phosphorylation and inactivation of the transcription factor FOXO3a. RNAi experiments demonstrate that FOXO3a activity is critical for the cell death observed on soft substrates. Additionally, downregulation of FOXO3a activity on stiff substrate leads to the degradation of the proapoptotic protein Bim. Depletion of Bim increased the survival of cells on soft substrates. Together, our data show that enhanced matrix stiffness activates a RasGRF1/Ras signaling cascade that regulates the activity of AKT and ERK-dependent FOXO3a and Bim expression to alter cell survival.

References

Guerrero C, Rojas J, Chedid M, Esteban L, Zimonjic D, Popescu N . Expression of alternative forms of Ras exchange factors GRF and SOS1 in different human tissues and cell lines. Oncogene. 1996; 12(5):1097-107. View

Frye M, Taddei A, Dierkes C, Martinez-Corral I, Fielden M, Ortsater H . Matrix stiffness controls lymphatic vessel formation through regulation of a GATA2-dependent transcriptional program. Nat Commun. 2018; 9(1):1511. PMC: 5904183. DOI: 10.1038/s41467-018-03959-6. View

Biggs 3rd W, Meisenhelder J, Hunter T, Cavenee W, Arden K . Protein kinase B/Akt-mediated phosphorylation promotes nuclear exclusion of the winged helix transcription factor FKHR1. Proc Natl Acad Sci U S A. 1999; 96(13):7421-6. PMC: 22101. DOI: 10.1073/pnas.96.13.7421. View

Burgering B, Kops G . Cell cycle and death control: long live Forkheads. Trends Biochem Sci. 2002; 27(7):352-60. DOI: 10.1016/s0968-0004(02)02113-8. View

Tsai T, Lin C, Chua S, Chung S, Chen S, Lee C . Deletion of RasGRF1 Attenuated Interstitial Fibrosis in Streptozotocin-Induced Diabetic Cardiomyopathy in Mice through Affecting Inflammation and Oxidative Stress. Int J Mol Sci. 2018; 19(10). PMC: 6213028. DOI: 10.3390/ijms19103094. View

Liu F, Tschumperlin D . Micro-mechanical characterization of lung tissue using atomic force microscopy. J Vis Exp. 2011; (54). PMC: 3217627. DOI: 10.3791/2911. View

Liu F, Lagares D, Choi K, Stopfer L, Marinkovic A, Vrbanac V . Mechanosignaling through YAP and TAZ drives fibroblast activation and fibrosis. Am J Physiol Lung Cell Mol Physiol. 2014; 308(4):L344-57. PMC: 4329470. DOI: 10.1152/ajplung.00300.2014. View

Leaner V, Donninger H, Ellis C, Clark G, Birrer M . p75-Ras-GRF1 is a c-Jun/AP-1 target protein: its up regulation results in increased Ras activity and is necessary for c-Jun-induced nonadherent growth of Rat1a cells. Mol Cell Biol. 2005; 25(8):3324-37. PMC: 1069594. DOI: 10.1128/MCB.25.8.3324-3337.2005. View

Weston C, Balmanno K, Chalmers C, Hadfield K, Molton S, Ley R . Activation of ERK1/2 by deltaRaf-1:ER* represses Bim expression independently of the JNK or PI3K pathways. Oncogene. 2003; 22(9):1281-93. DOI: 10.1038/sj.onc.1206261. View

10.

Cen H, Papageorge A, Vass W, Zhang K, Lowy D . Regulated and constitutive activity by CDC25Mm (GRF), a Ras-specific exchange factor. Mol Cell Biol. 1993; 13(12):7718-24. PMC: 364843. DOI: 10.1128/mcb.13.12.7718-7724.1993. View

11.

Le Gall M, Chambard J, Breittmayer J, Grall D, Pouyssegur J, Van Obberghen-Schilling E . The p42/p44 MAP kinase pathway prevents apoptosis induced by anchorage and serum removal. Mol Biol Cell. 2000; 11(3):1103-12. PMC: 14834. DOI: 10.1091/mbc.11.3.1103. View

12.

Meadows K, Bryant P, Pumiglia K . Vascular endothelial growth factor induction of the angiogenic phenotype requires Ras activation. J Biol Chem. 2001; 276(52):49289-98. DOI: 10.1074/jbc.M108069200. View

13.

Paoli P, Giannoni E, Chiarugi P . Anoikis molecular pathways and its role in cancer progression. Biochim Biophys Acta. 2013; 1833(12):3481-3498. DOI: 10.1016/j.bbamcr.2013.06.026. View

14.

Discher D, Janmey P, Wang Y . Tissue cells feel and respond to the stiffness of their substrate. Science. 2005; 310(5751):1139-43. DOI: 10.1126/science.1116995. View

15.

Fernandez-Medarde A, Santos E . The RasGrf family of mammalian guanine nucleotide exchange factors. Biochim Biophys Acta. 2010; 1815(2):170-88. DOI: 10.1016/j.bbcan.2010.11.001. View

16.

Meng Z, Qiu Y, Lin K, Kumar A, Placone J, Fang C . RAP2 mediates mechanoresponses of the Hippo pathway. Nature. 2018; 560(7720):655-660. PMC: 6128698. DOI: 10.1038/s41586-018-0444-0. View

17.

Bouillet P, Cory S, Zhang L, Strasser A, Adams J . Degenerative disorders caused by Bcl-2 deficiency prevented by loss of its BH3-only antagonist Bim. Dev Cell. 2001; 1(5):645-53. DOI: 10.1016/s1534-5807(01)00083-1. View

18.

Li Z, Razavi P, Li Q, Toy W, Liu B, Ping C . Loss of the FAT1 Tumor Suppressor Promotes Resistance to CDK4/6 Inhibitors via the Hippo Pathway. Cancer Cell. 2018; 34(6):893-905.e8. PMC: 6294301. DOI: 10.1016/j.ccell.2018.11.006. View

19.

Al-Tamari H, Dabral S, Schmall A, Sarvari P, Ruppert C, Paik J . FoxO3 an important player in fibrogenesis and therapeutic target for idiopathic pulmonary fibrosis. EMBO Mol Med. 2017; 10(2):276-293. PMC: 5801513. DOI: 10.15252/emmm.201606261. View

20.

Brunet A, Bonni A, Zigmond M, Lin M, Juo P, Hu L . Akt promotes cell survival by phosphorylating and inhibiting a Forkhead transcription factor. Cell. 1999; 96(6):857-68. DOI: 10.1016/s0092-8674(00)80595-4. View