Dihydrosphingosine driven enrichment of sphingolipids attenuates TGFβ induced collagen synthesis in cardiac fibroblasts

Ruth R Magaye; Feby Savira; Xin Xiong; Kevin Huynh; Peter J Meikle; Christopher Reid; Bernard L Flynn; David Kaye; Danny Liew; Bing H Wang

doi:10.1016/j.ijcha.2021.100837

Dihydrosphingosine driven enrichment of sphingolipids attenuates TGFβ induced collagen synthesis in cardiac fibroblasts

Int J Cardiol Heart Vasc. 2021 Jul 6:35:100837. doi: 10.1016/j.ijcha.2021.100837. eCollection 2021 Aug.

Authors

Ruth R Magaye^{1

2}, Feby Savira^{1

2}, Xin Xiong^{1

2

3}, Kevin Huynh⁴, Peter J Meikle^{4

5}, Christopher Reid^{2

5}, Bernard L Flynn⁶, David Kaye⁷, Danny Liew², Bing H Wang^{1

2}

Affiliations

¹ Biomarker Discovery Laboratory, Baker Heart and Diabetes Institute, Melbourne, Australia.
² Monash Centre of Cardiovascular Research and Education in Therapeutics, Melbourne, Australia.
³ Shanghai Institute of Heart Failure, Research Centre for Translational Medicine, Shanghai East Hospital, Tongji University, School of Medicine, Shanghai 200120, PR China.
⁴ Metabolomics Research Group, Baker Heart and Diabetes Institute, Melbourne, Australia.
⁵ School of Public Health School, Curtin University, Perth, Australia.
⁶ Monash Institute of Pharmaceutical Sciences, Monash University, Melbourne, Australia.
⁷ Heart Failure Research Group, Baker Heart and Diabetes Institute, Melbourne, Australia.

Abstract

The sphingolipid de novo synthesis pathway, encompassing the sphingolipids, the enzymes and the cell membrane receptors, are being investigated for their role in diseases and as potential therapeutic targets. The intermediate sphingolipids such as dihydrosphingosine (dhSph) and sphingosine (Sph) have not been investigated due to them being thought of as precursors to other more active lipids such as ceramide (Cer) and sphingosine 1 phosphate (S1P). Here we investigated their effects in terms of collagen synthesis in primary rat neonatal cardiac fibroblasts (NCFs). Our results in NCFs showed that both dhSph and Sph did not induce collagen synthesis, whilst dhSph reduced collagen synthesis induced by transforming growth factor β (TGFβ). The mechanisms of these inhibitory effects were associated with the increased activation of the de novo synthesis pathway that led to increased dihydrosphingosine 1 phosphate (dhS1P). Subsequently, through a negative feedback mechanism that may involve substrate-enzyme receptor interactions, S1P receptor 1 expression (S1PR1) was reduced.

Keywords: Akt, protein kinase B; CTGF, connective tissue growth factor; Cardiac fibroblasts; Cer, ceramide; Cer1P, ceramide 1 phosphate; Coll1a1, collagen 1a1; Collagen synthesis; Degs1, dihydroceramide desaturase 1 gene; Des-1, dihydroceramide desaturase 1 enzyme; Dihydrosphingosine; ECM, extracellular matrix inhibitor of nuclear kappa B (NFKβ) kinase alpha and beta (IKKα/β); MA3PK, mitogen activated protein kinase kinase kinase; MAPK, mitogren activated protein kinase; MI, myocardial infarct; MMP2, matrix metalloproteinase 2; NCF, neonatal cardiac fibroblasts; RPS6, ribosomal protein S6; S1P, sphingosine-1 Phosphate; S1PR1, sphingosine -1-phosphate receptor 1; S1PRs, sphingosine 1 phosphate receptor 1-5; SK1, sphingosine kinase 1; Sph, sphingosine; Sphingolipid; TAK1, transforming growth factor β activating kinase 1; TGFβ; TGFβ, transforming growth factor β; TIMP1, tissue inhibitor of metalloproteinase 1; d7dhSph, deuterated dihydrosphingosine; dhCer, dihydroceramide; dhS1P, dihydrosphingosine 1 phosphate; mTOR, mammalian target for rapamycin.