C18 dihydro Ceramide (d18:0/18:0)

C18 dihydro Ceramide is a bioactive sphingolipid and precursor in the de novo synthesis of C18 ceramide that lacks the 4,5-trans double bond. [1] Increased C18 dihydroceramide lipid levels lead to increased triacylglycerol storage and autophagosome accumulation as well as upregulation of the fibrosis markers α-SMA and FGF2 in Chang and LX-2 liver cells. C18 dihydro Ceramide is elevated in the plasma of pre-diabetics up to 9 years prior to the onset of type 2 diabetes. [2]  It is also elevated in the skin of patients with lesional atopic dermatitis.[3]

Reference:
[1]. Lee, A.Y., Lee, J.W., Kim, J.-E., et al. Dihydroceramide is a key metabolite that regulates autophagy and promotes fibrosis in hepatic steatosis model. Biochem. Biophys. Res. Commun. 494(3-4), 460-469 (2017).
[2]. Wigger, L., Cruciani-Guglielmacci, C., Nicolas, A., et al. Plasma dihydroceramides are diabetes susceptibility biomarker candidates in mice and humans. Cell Rep. 18(9), 2269-2279 (2017).
[3]. Joo, J.-M., Hwang, J.-H., Bae, S., et al. Relationship of ceramide-, and free fatty acid-cholesterol ratios in the stratum corneum with skin barrier function of normal, atopic dermatitis lesional and non-lesional skins. J. Dermatol. Sci. 77(1), 71-74 (2015).