The metabolism of phospholipids oscillates rhythmically in cultures of fibroblasts and is regulated by the clock protein PERIOD 1.

MARQUEZ S; CRESPO P; CARLINI V; GARBARINO PICO E; BALER R; CAPUTTO BL; GUIDO ME

FEDERATION AMER SOC EXP BIOL

Año: 2004 vol. 18 p. 519 - 519

p class="abstract">The mammalian circadian timing system is composed of countless cell oscillators distributed throughout the body and central pacemakers regulating temporal physiology and behavior. Peripheral clocks display circadian rhythms in gene expression both in vivo and in culture. We examined the biosynthesis of phospholipids as well as the expression of the clock gene period 1 (Per1) and its potential involvement in the regulation of the phospholipid metabolism in cultured quiescent NIH 3T3 cells synchronized by a 2 h serum shock. A 30 min pulse of radiolabeled precursor was given at phases ranging from 0.5 to 62 h after serum treatment. We observed a daily rhythm in the phospholipid labeling that persisted at least for two cycles, with levels significantly decreasing 29 and 58 h after treatment. Per1 expression exhibited a rapid and transient induction and a daily rhythmicity in antiphase to the lipid labeling. After Per1 expression knockdown, the rhythm of phospholipid lab