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Inactivation of Ceramide Synthase 6 in Mice Results in an Altered Sphingolipid Metabolism and Behavioral Abnormalities

2013; Elsevier BV; Volume: 288; Issue: 29 Linguagem: Inglês

10.1074/jbc.m113.479907

1083-351X

Philipp Ebel, Katharina vom Dorp, Elisabeth Petrasch‐Parwez, Armin Zlomuzica, Kiyoka Kinugawa, Jean Mariani, David Minich, Christina Ginkel, Jochen Welcker, Joachim Degen, Matthias Eckhardt, Ekrem Dere, Peter Dörmann, Klaus Willecke,

Lysosomal Storage Disorders Research

The N-acyl chain length of ceramides is determined by the specificity of different ceramide synthases (CerS). The CerS family in mammals consists of six members with different substrate specificities and expression patterns. We have generated and characterized a mouse line harboring an enzymatically inactive ceramide synthase 6 (CerS6KO) gene and lacz reporter cDNA coding for β-galactosidase directed by the CerS6 promoter. These mice display a decrease in C16:0 containing sphingolipids. Relative to wild type tissues the amount of C16:0 containing sphingomyelin in kidney is ∼35%, whereas we find a reduction of C16:0 ceramide content in the small intestine to about 25%. The CerS6KO mice show behavioral abnormalities including a clasping abnormality of their hind limbs and a habituation deficit. LacZ reporter expression in the brain reveals CerS6 expression in hippocampus, cortex, and the Purkinje cell layer of the cerebellum. Using newly developed antibodies that specifically recognize the CerS6 protein we show that the endogenous CerS6 protein is N-glycosylated and expressed in several tissues of mice, mainly kidney, small and large intestine, and brain.Background: Ceramide synthases N-acylate (dihydro-)sphingosine to (dihydro-)ceramide in mammals.Results: Enzymatically inactive ceramide synthase 6 in mice (CerS6KO) results in an altered sphingolipid metabolism and behavioral abnormalities.Conclusion: Catalytically active CerS6 is necessary to maintain sphingolipid homeostasis in mice.Significance: The CerS6KO mouse reveals for the first time the metabolic and physiological consequences of CerS6 inactivation. The N-acyl chain length of ceramides is determined by the specificity of different ceramide synthases (CerS). The CerS family in mammals consists of six members with different substrate specificities and expression patterns. We have generated and characterized a mouse line harboring an enzymatically inactive ceramide synthase 6 (CerS6KO) gene and lacz reporter cDNA coding for β-galactosidase directed by the CerS6 promoter. These mice display a decrease in C16:0 containing sphingolipids. Relative to wild type tissues the amount of C16:0 containing sphingomyelin in kidney is ∼35%, whereas we find a reduction of C16:0 ceramide content in the small intestine to about 25%. The CerS6KO mice show behavioral abnormalities including a clasping abnormality of their hind limbs and a habituation deficit. LacZ reporter expression in the brain reveals CerS6 expression in hippocampus, cortex, and the Purkinje cell layer of the cerebellum. Using newly developed antibodies that specifically recognize the CerS6 protein we show that the endogenous CerS6 protein is N-glycosylated and expressed in several tissues of mice, mainly kidney, small and large intestine, and brain. Background: Ceramide synthases N-acylate (dihydro-)sphingosine to (dihydro-)ceramide in mammals. Results: Enzymatically inactive ceramide synthase 6 in mice (CerS6KO) results in an altered sphingolipid metabolism and behavioral abnormalities. Conclusion: Catalytically active CerS6 is necessary to maintain sphingolipid homeostasis in mice. Significance: The CerS6KO mouse reveals for the first time the metabolic and physiological consequences of CerS6 inactivation.