A novel CAVIN1/GAS5 axis suppresses skin fibrosis through mitochondrial fission-mediated attenuation of the TGF-β/Smad pathway

Abstract

Background: Keloids, which are characterized by excessive collagen deposition and fibroblast hyperactivation, present significant therapeutic challenges because of their high recurrence rates and incompletely understood pathogenesis. The transforming growth factor-β (TGF-β) pathway is a central driver, but its upstream regulators in the development of skin fibrosis remain elusive. In this study, we aimed to identify novel upstream modulators of skin fibrosis and to elucidate the underlying molecular mechanisms by which these modulators regulate TGF-β signaling in keloid pathogenesis. Methods: We integrated results of transcriptomic and proteomic analyses of patient-derived keloid and normal skin tissues. Functional validation was performed by using primary keloid fibroblasts (KFs) with gain-and loss-of-function approaches, RNA immunoprecipitation sequencing (RIP-seq), and actinomycin D chase assays. Two independent bleomycin-induced skin fibrosis mouse models were employed for in vivo validation. Results: Multiomics profiling revealed that caveolae-associated protein 1 (CAVIN1) was consistently downregulated in keloids. CAVIN1 overexpression in KFs suppressed fibrotic phenotypes, including migration, invasion, collagen contraction, and extracellular matrix protein expression. Mechanistically, CAVIN1 directly bound to and stabilized the mitochondrial long noncoding RNA GAS5. This CAVIN1/GAS5 axis inhibited Drp1/Fis1-mediated mitochondrial fission and subsequent reactive oxygen species (ROS) production, leading to the attenuation of the canonical TGF-β/Smad2/3 signaling pathway. Critically, GAS5 silencing abrogated the antifibrotic effects of CAVIN1. Furthermore, database screening revealed that the histone deacetylase inhibitor vorinostat was a CAVIN1-upregulating compound. Both AAV-mediated CAVIN1 overexpression and vorinostat treatment significantly ameliorated skin fibrosis in the mouse models. Conclusions: Our study reports a novel CAVIN1/GAS5 axis that concurrently targets mitochondrial fission and the TGF-β/Smad pathway to suppress skin fibrosis. These findings not only reveal a previously unrecognized mechanistic link in keloid pathogenesis but also identify CAVIN1 as a promising therapeutic target, with vorinostat as a potential repurposable drug for treating fibrotic skin disorders.

Keywords

CAVIN1 / Long non-coding RNA GAS5 / Mitochondrial fission / Skin fibrosis / Keloid

References

[1] Zhang M, Chen H, Qian H, Wang C. Characterization of the skin keloid microenvironment. Cell Commun Signal 2023; 21:207. https://doi.org/10.1186/s12964-023-01214-0.

[2] Kim HJ, Kim YH. Comprehensive insights into keloid pathogenesis and advanced therapeutic strategies. Int J Mol Sci 2024; 25:8776. https://doi.org/10.3390/ijms25168776.

[3] Bijlard E, Kouwenberg CA, Timman R, Hovius SE, Busschbach JJ, Mureau MA. Burden of keloid disease: a cross-sectional health-related quality of life assessment. Acta Derm Venereol 2017; 97:225-9. https://doi.org/10.2340/00015555-2498.

[4] Yin Q, Niessen FB, Gibbs S, Lapid O, Louter JMI, Zuijlen V, et al. Intralesional corticosteroid administration in the treatment of keloids: a survey among Dutch dermatologists and plastic surgeons. J Dermatolog Treat 2023; 34:2159308. https://doi.org/10.1080/09546634.2022.2159308.

[5] Leszczynski R, da Silva CA, Pinto ACPN, Kuczynski U, da Silva EM. Laser therapy for treating hypertrophic and keloid scars. Cochrane Database Syst Rev 2022; 2022:CD011642. https://doi.org/10.1002/14651858.CD011642.pub2.

[6] Ekstein SF, Wyles SP, Moran SL, Meves A. Keloids: a review of therapeutic management. Int J Dermatol 2021; 60:661-71. https://doi.org/10.1111/ijd.15159.

[7] Meng XM, Nikolic-Paterson DJ, Lan HY. TGF-β: the master regulator of fibrosis. Nat Rev Nephrol 2016; 12:325-38. https://doi.org/10.1038/nrneph.2016.48.

[8] Hu HH, Chen DQ, Wang YN, Feng YL, Cao G, Vaziri ND, et al. New insights into TGF-β/Smad signaling in tissue fibrosis. Chem Biol Interact 2018; 292:76-83. https://doi.org/10.1016/j.cbi.2018.07.008.

[9] Kelsh RM, McKeown-Longo PJ, Clark RAF. EDA fibronectin in keloids create a vicious cycle of fibrotic tumor formation. J Invest Dermatol 2015; 135:1714-8. https://doi.org/10.1038/jid.2015.155.

[10] Si S, Liu H, Xu L, Zhan S. Identification of novel therapeutic targets for chronic kidney disease and kidney function by integrating multi-omics proteome with transcriptome. Genome Med 2024; 16:84. https://doi.org/10.1186/s13073-024-01356-x.

[11] Tillu VA, Rae J, Gao Y, Ariotti N, Floetenmeyer M, Kovtun O, et al. Cavin1 intrinsically disordered domains are essential for fuzzy electrostatic interactions and caveola formation. Nat Commun 2021; 12:931. https://doi.org/10.1038/s41467-021-21035-4.

[12] Wu Y, Lim YW, Stroud DA, Martel N, Hall TE, Lo HP, et al. Caveolae sense oxidative stress through membrane lipid peroxidation and cytosolic release of CAVIN1 to regulate NRF2. Dev Cell 2023; 58:376-397.e4. https://doi.org/10.1016/j.devcel.2023.02.004.

[13] Taniguchi T, Maruyama N, Ogata T, Kasahara T, Nakanishi N, Miyagawa K, et al. PTRF/Cavin-1 deficiency causes cardiac dysfunction accompanied by cardiomyocyte hypertrophy and cardiac fibrosis. PLoS One 2016; 11:e0162513. https://doi.org/10.1371/journal.pone.0162513.

[14] Zhou Y, Chen B. GAS5-mediated regulation of cell signaling (review). Mol Med Rep 2020; 22:3049-56. https://doi.org/10.3892/mmr.2020.11435.

[15] Tu B, Song K, Zhou Y, Sun H, Liu Z, Lin L, et al. METTL3 boosts mitochondrial fission and induces cardiac fibrosis by enhancing LncRNA GAS5 methylation. Pharmacol Res 2023; 194:106840. https://doi.org/10.1016/j.phrs.2023.106840.

[16] Zhang YY, Tan RZ, Yu Y, Niu YY, Yu C. LncRNA GAS5 protects against TGF-β-induced renal fibrosis via the Smad3/miRNA-142-5p axis. Am J Physiol Renal Physiol 2021; 321:F517-26. https://doi.org/10.1152/ajprenal.00085.2021.

[17] Dong Z, Li S, Wang X, Si L, Ma R, Bao L, et al. lncRNA GAS5 restrains CCl4-induced hepatic fibrosis by targeting miR-23a through the PTEN/PI3K/Akt signaling pathway. Am J Physiol Gastrointest Liver Physiol 2019; 316:G539-50. https://doi.org/10.1152/ajpgi.00249.2018.

[18] Patra S, Praharaj PP, Klionsky DJ, Bhutia SK. Vorinostat in autophagic cell death: a critical insight into autophagy-mediated, −associated and-dependent cell death for cancer prevention. Drug Discov Today 2022; 27:269-79. https://doi.org/10.1016/j.drudis.2021.08.004.

[19] Yang H, Xu H, Wang Z, Li X, Wang P, Cao X, et al. Analysis of miR-203a-3p/SOCS3-mediated induction of M2 macrophage polarization to promote diabetic wound healing based on epidermal stem cell-derived exosomes. Diabetes Res Clin Pract 2023; 197:110573. https://doi.org/10.1016/j.diabres.2023.110573.

[20] Yang H, Lv D, Li X, Chen Y, Xu H, Wu H, et al. Comprehensive analysis of keloid super-enhancer networks reveals FOXP1-mediated anti-senescence mechanisms in fibrosis. Cell Mol Biol Lett 2025; 30:88. https://doi.org/10.1186/s11658-025-00763-1.

[21] Yi K, Cui X, Liu X, Wang Y, Zhao J, Yang S, et al. PTRF/Cavin-1 as a novel RNA-binding protein expedites the NF-κB/PD-L1 Axis by stabilizing lncRNA NEAT1, contributing to tumorigenesis and immune evasion in glioblastoma. Front Immunol 2022; 12:802795. https://doi.org/10.3389/fimmu.2021.802795.

[22] Yu T, Wang L, Zhang L, Deuster PA. Mitochondrial fission as a therapeutic target for metabolic diseases: insights into antioxidant strategies. Antioxidants (Basel) 2023; 12:1163. https://doi.org/10.3390/antiox12061163.

[23] Zhang T, Wang XF, Wang ZC, Lou D, Fang QQ, Hu YY, et al. Current potential therapeutic strategies targeting the TGF-β/Smad signaling pathway to attenuate keloid and hypertrophic scar formation. Biomed Pharmacother 2020; 129:110287. https://doi.org/10.1016/j.biopha.2020.110287.

[24] Wynn TA. Cellular and molecular mechanisms of fibrosis. J Pathol 2008; 214:199-210. https://doi.org/10.1002/path.2277.

[25] Tao H, Zhang JG, Qin RH, Dai C, Shi P, Yang JJ, et al. LncRNA GAS5 controls cardiac fibroblast activation and fibrosis by targeting miR-21 via PTEN/MMP-2 signaling pathway. Toxicology. 2017; 386:11-8. https://doi.org/10.1016/j.tox.2017.05.007.

[26] Yu F, Zheng J, Mao Y, Dong PH, Lu ZQ, Li GJ, et al. Long non-coding RNA growth arrest-specific transcript 5 (GAS5) inhibits liver fibrogenesis through a mechanism of competing endogenous RNA. J Biol Chem 2015; 290:28286-98. https://doi.org/10.1074/jbc.M115.683813.

[27] Xiang Z, Liqing Y, Qingqing Y, Qiang H, Hongbo C . Retard or exacerbate: role of long non-coding RNA growth arrest-specific 5 in the fibrosis. Cytokine Growth Factor Rev 2022; 67:89-104. https://doi.org/10.1016/j.cytogfr.2022.06.001.

[28] Tong Z, Du X, Zhou Y, Jing FX, Ma JP, Feng YY, et al. Drp1-mediated mitochondrial fission promotes pulmonary fibrosis progression through the regulation of lipid metabolic reprogramming by ROS/HIF-1α. Cell Signal 2024; 117:111075. https://doi.org/10.1016/j.cellsig.2024.111075.

[29] Wang Y, Lu M, Xiong L, Fan JJ, Zhou Y, Li HY, et al. Drp1-mediated mitochondrial fission promotes renal fibroblast activation and fibrogenesis. Cell Death Dis 2020; 11:29. https://doi.org/10.1038/s41419-019-2218-5.

[30] Wang J, Yang Y, Sun F, Luo Y, Yang Y, Li J. et al. ALKBH5 attenuates mitochondrial fission and ameliorates liver fibrosis by reducing Drp1 methylation. Pharmacol Res 2023; 187:106608. https://doi.org/10.1016/j.phrs.2022.106608.

[31] Chen B, Yu D, Qin Z, Zhao R, Li Y, Li Q, et al. Mitochondrial dysfunctions of keloid fibroblasts and it’s effects on cell metabolic functions. Zhonghua Zheng Xing Wai Ke Za Zhi 2016; 32:359-64. https://doi.org/10.3760/cma.j.issn.1009-4598.2016.05.010.

[32] Jain M, Rivera S, Monclus EA, Synenki L, Zirk A, Eisenbart J, et al. Mitochondrial reactive oxygen species regulate transforming growth factor-β signaling. J Biol Chem 2013; 288:770-7. https://doi.org/10.1074/jbc.M112.431973.

[33] Liu RM, Desai LP. Reciprocal regulation of TGF-β and reactive oxygen species: a perverse cycle for fibrosis. Redox Biol 2015; 6:565-77. https://doi.org/10.1016/j.redox.2015.09.009.

[34] Zhang GY, Yu Q, Cheng T, Liao T, Nie CL, Wang AY, et al. Role of caveolin-1 in the pathogenesis of tissue fibrosis by keloid-derived fibroblasts in vitro. Br J Dermatol 2011; 164:623-7. https://doi.org/10.1111/j.1365-2133.2010.10111.x.

[35] Takamura N, Yamaguchi Y. Involvement of caveolin-1 in skin diseases. Front Immunol 2022; 13:1035451. https://doi.org/10.3389/fimmu.2022.1035451.

[36] Yoon S, Kang G, Eom GH. HDAC inhibitors: therapeutic potential in fibrosis-associated human diseases. Int J Mol Sci 2019; 20:1329. https://doi.org/10.3390/ijms20061329.

[37] Lyu X, Hu M, Peng J, Zhang X, Sanders YY. HDAC inhibitors as antifibrotic drugs in cardiac and pulmonary fibrosis. Ther Adv Chronic Dis 2019; 10:2040622319862697. https://doi.org/10.1177/2040622319862697.

[38] Sanders YY, Hagood JS, Liu H, Zhang W, Ambalavanan N, Thannickal VJ. Histone deacetylase inhibition promotes fibroblast apoptosis and ameliorates pulmonary fibrosis in mice. Eur Respir J 2014; 43:1448-58. https://doi.org/10.1183/09031936.00095113.

[39] Diao JS, Xia WS, Yi CG, Wang YM, Li B, Xia W, et al. Trichostatin a inhibits collagen synthesis and induces apoptosis in keloid fibroblasts. Arch Dermatol Res 2011; 303:573-80. https://doi.org/10.1007/s00403-011-1140-1.

[40] Fitzgerald O’Connor EJ, Badshah II, Addae LY, Kundasamy P, Thanabalasingam S, Abioye D, et al. Histone deacetylase 2 is upregulated in normal and keloid scars. J Invest Dermatol 2012; 132:1293-6. https://doi.org/10.1038/jid.2011.432.

[41] Diao JS, Xia WS, Yi CG, Yang Y, Zhang X, Xia W, et al. Histone deacetylase inhibitor reduces hypertrophic scarring in a rabbit ear model. Plast Reconstr Surg 2013; 132:61e-9. https://doi.org/10.1097/PRS.0b013e318290f698.

[42] Yin Q, Wolkerstorfer A, Lapid O, Qayumi K, Alam M, Al-Niaimi F, et al. KECORT study: an international e-Delphi study on the treatment of KEloids using Intralesional CORTicosteroids in clinical practice. Am J Clin Dermatol 2024; 25:1009-17. https://doi.org/10.1007/s40257-024-00888-7.

[43] Zhu K, Song Q, Pan L, Xiong F. Efficacy and safety of glucocorticoid-based therapies in the management of keloids: a systematic review and meta-analysis of clinical outcomes. Front Med (Lausanne) 2026; 12:1749329. https://doi.org/10.3389/fmed.2025.1749329.

[44] Ding J, Zhang Z, Li S, Wang W, Du TY, Fang Q, et al. Mdivi-1 alleviates cardiac fibrosis post myocardial infarction at infarcted border zone, possibly via inhibition of Drp1-activated mitochondrial fission and oxidative stress. Arch Biochem Biophys 2022; 718:109147. https://doi.org/10.1016/j.abb.2022.109147.

[45] Gegg ME, Cooper JM, Chau KY, Rojo M, Schapira AH, Taanman JW. Mitofusin 1 and mitofusin 2 are ubiquitinated in a PINK1/parkin-dependent manner upon induction of mitophagy. Hum Mol Genet 2010; 19:4861-70. https://doi.org/10.1093/hmg/ddq419.

[46] Limandjaja GC, Niessen FB, Scheper RJ, Gibbs S. The keloid disorder: heterogeneity, histopathology, mechanisms and models. Front Cell Dev Biol 2020; 8:360. https://doi.org/10.3389/fcell.2020.00360.

[47] Tan Q, Link PA, Meridew JA, Pham TX, Caporarello N, Ligresti G, et al. Spontaneous lung fibrosis resolution reveals novel antifibrotic regulators. Am J Respir Cell Mol Biol 2021;64:453-64. https://doi.org/10.1165/rcmb.2020-0396OC.

[48] Tan S, Khumalo N, Bayat A. Understanding keloid pathobiology from a quasi-neoplastic perspective: less of a scar and more of a chronic inflammatory disease with cancer-like tendencies. Front Immunol 2019; 10:1810. https://doi.org/10.3389/fimmu.2019.01810.

[49] Lee YI, Shim JE, Kim J, Lee WJ, Kim JW, Nam KH, et al. WNT5A drives interleukin-6-dependent epithelial-mesenchymal transition via the JAK/STAT pathway in keloid pathogenesis. Burns. Trauma 2022; 10:tkac023. https://doi.org/10.1093/burnst/tkac023.