Sphingomyelins and ceramides with very-long-chain PUFA are excluded from low-density raft-like domains in differentiating spermatogenic cells

SANTIAGO VALTIERRA, F.X.; MATEOS, M.V.; AVELDAÑO, M.I.; ORESTI, G.M. (CORRESPONDING AUTHOR)

JLR PAPERS IN PRESS

AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC

Lugar: Bethesda, Maryland; Año: 2017

0022-2275

Rat spermatogenic cells contain sphingomyelins(SMs) and ceramides (Cers) with very long-chain PUFAs(VLCPUFAs) in nonhydroxylated (n-V) and 2-hydroxylated(h-V) forms. How these atypical species distribute amongmembrane fractions during differentiation was investigatedhere using a detergent-free procedure to isolate a small lightraft-like low-density fraction and a large heavy fraction, mostlyderived from the plasma membrane of spermatocytes, roundspermatids, and late spermatids. The light fraction containedcholesterol, glycerophospholipids (GPLs), and SM with thesame saturated fatty acids in all three stages. In the heavy fraction,as PUFA increased in the GPL and VLCPUFA in SM fromspermatocytes to spermatids, the concentration of cholesterolwas also augmented. The heavy fraction had mostly n-V SM inspermatocytes, but accumulated h-V SM and h-V Cer in spermatids.A fraction containing intracellular membranes hadless SM and more Cer than the latter, but in both fractions SMand Cer species with h-V increased over species with n-V withdifferentiation. This accretion of h-V was consistent with thedifferentiation-dependent expression of fatty acid 2-hydroxylase(Fa2h), as it increased significantly from spermatocytes tospermatids. The non-raft region of the plasma membrane isthus the main target of the dynamic lipid synthesis and remodelingthat is involved in germ cell differentiation.?SantiagoValtierra, F. X., M. V. Mateos, M. I. Aveldaño, and G. M.Oresti. Sphingomyelins and ceramides with VLCPUFAs areexcluded from low-density raft-like domains in differentiatingspermatogenic cells. J. Lipid Res. 2017. 58: 529?542.