Validation of highly selective Sphingosine kinase 2 inhibitors SLM6031434 and HWG-35D as effective anti-fibrotic treatment options in a mouse model of tubulointerstitial fibrosis

Schwalm, Stephanie and Beyer, Sandra and Hafizi, Redona and Traufmann, Sandra and Geisslinger, Gerd and Adams, David R. and Pyne, Susan and Pyne, Nigel and Schaefer, Liliana and Huwiler, Andrea and Pfeilschifter, Josef (2021) Validation of highly selective Sphingosine kinase 2 inhibitors SLM6031434 and HWG-35D as effective anti-fibrotic treatment options in a mouse model of tubulointerstitial fibrosis. Cellular Signalling, 79. 109881. ISSN 1873-3913 (https://doi.org/10.1016/j.cellsig.2020.109881)

[thumbnail of Schwalm-etal-CS-2020-Validation-of-highly-selective-Sphingosine-kinase-2-inhibitors-SLM6031434-and-HWG-35D]
Preview
Text. Filename: Schwalm_etal_CS_2020_Validation_of_highly_selective_Sphingosine_kinase_2_inhibitors_SLM6031434_and_HWG_35D.pdf
Accepted Author Manuscript
License: Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 logo

Download (1MB)| Preview

Abstract

Renal fibrosis is characterized by chronic inflammation and excessive accumulation of extracellular matrix and progressively leads to functional insufficiency and even total loss of kidney function. In this study we investigated the anti-fibrotic potential of two highly selective and potent SK2 inhibitors, SLM6031434 and HWG-35D, in unilateral ureter obstruction (UUO), a model for progressive renal fibrosis, in mice. In both cases, treatment with SLM6031434 or HWG-35D resulted in an attenuated fibrotic response to UUO in comparison to vehicle-treated mice as demonstrated by reduced collagen accumulation and a decreased expression of collagen-1 (Col1), fibronectin-1 (FN-1), connective tissue growth factor (CTGF), and α-smooth muscle actin (α-SMA). Similar to our previous study in Sphk2 −/− mice, we found an increased protein expression of Smad7, a negative regulator of the pro-fibrotic TGFβ/Smad signalling cascade, accompanied by a strong accumulation of sphingosine in SK2 inhibitor-treated kidneys. Treatment of primary renal fibroblasts with SLM6031434 or HWG-35D dose-dependently increased Smad7 expression and ameliorated the expression of Col1, FN-1 and CTGF. In summary, these data prove the anti-fibrotic potential of SK2 inhibition in a mouse model of renal fibrosis, thereby validating SK2 as pharmacological target for the treatment of fibrosis in chronic kidney disease.