Microtubule depolymerization modifies the incorporation of fatty acids into glycerolipids

MARRA C. A.; TACCONI DE ALANIZ M.J.

MEDICAL SCIENCE MONITOR

INT SCIENTIFIC LITERATURE, INC

Año: 2009 vol. 15 p. 157 - 165

1234-1010

SUMMARY Background: The influence of cytoskeleton integrity on fatty acid metabolism is an almost unexplored field of biochemistry research. Thus, we studied the influence of cytoskeleton integrity on the incorporation of palmitate and eicosa-8,11,4-trienoate into glycerolipids of Hep G2 human hepatoma cells. Materials and Methods: Attached cultures and suspended cells were exposed to colchicine (COL, 10 µM) or dihidrocytochalasin B (DHCB, 20 µM) and supplemented with [14C]FAs bound to delipidated BSA or [14C]glycerol during 0-300 min incubation time. Various key enzymes of lipid metabolism were also determined after COL or DHCB treatment. Results: Incorporation of both FAs into phospholipids (PL) was strongly reduced by COL treatment especially in PE and PC subfractions at short incubation times and in PS and SM at 300 min. COL also produced increased incorporation of both FAs into neutral lipids (NL), especially in TG and its precursors (MG and DG). DHCB increased the labeling into lyso-PL and reduced the incorporation into PE and SM. However, this drug did not modify the ratio [14C]NL/ [14C]PL. DG-acyltransferase and phosphatidate-phosphohydrolase were stimulated by COL treatment. Phospholipase A2 activity was reduced significantly by COL and stimulated by DHCB treatment. Conclusions: We demonstrated that microtubule and microfilament network is involved in the incorporation of FAs and in its channeling to neutral lipids and phospholipids. These effects had differential characteristics depending of the type of FA involved, and may have potential significance in the understanding of physiological and/or pathological process.