TY - JOUR
T1 - Aging of rat heart fibroblasts
T2 - relationship between lipid composition, membrane organization and biological properties
AU - Yechiel, Elishalom
AU - Henis, Yoav I.
AU - Barenholz, Yechezkel
N1 - Funding Information:
This work was supported by the Umted States Pubhc Health Service, National /Institutes of Health, Grant HL17576, by The Basic Research Foundation of the Israel Academy of Sciences and Humanities, and by The Bat-Sheva de Rothschild Foundation The assistance of Ms Beryl Levene in the preparation of this manuscript is acknowledged with pleasure
PY - 1986/7/10
Y1 - 1986/7/10
N2 - The relationship between age-related alterations in the lipid composition of cultured rat-heart fibroblasts and several biochemical and biophysical parameters was investigated. Aged (14-15-day-old) cultures displayed higher mole ratios of sphingomyelin to phosphatidylcholine, as well as elevated cholesterol levels. A concomitant increase was observed in the total protein content of the cells and in the Vmax values of both membranal and cytoplasmic marker enzymes. Fluorescence photobleaching recovery was employed to study the lateral mobility of the lipid probe NBD-phosphatidylethanolamine and of membrane glycoproteins that bind succinylated concanavalin A. The mobile fractions of both probes were higher in aged cultures, while the lateral diffusion coefficients were lower. To further demonstrate the dependence of the above parameters on the cellular lipid composition, we have manipulated the lipid composition of old cultures by treatments with liposomes (small unilamellar vesicles) of specific compositions. Treatments which reversed the lipid composition towards that of young (5-6-day-old) cultures caused a concomitant reversal of the measured biochemical and biophysical parameters to the values observed in young cultures. These findings suggest that alterations in the organization and mobility of cell membrane constituents are involved in mediating changes in cellular functions. In view of our previous findings on cultures of rat-heart myocytes (Yechiel, E., Barenholz, Y. and Henis, Y.I. (1985) J. Biol. Chem. 260, 9132-9136), it appears that the modulation of cellular properties through the membrane lipid composition may be a general phenomenon in many cell types.
AB - The relationship between age-related alterations in the lipid composition of cultured rat-heart fibroblasts and several biochemical and biophysical parameters was investigated. Aged (14-15-day-old) cultures displayed higher mole ratios of sphingomyelin to phosphatidylcholine, as well as elevated cholesterol levels. A concomitant increase was observed in the total protein content of the cells and in the Vmax values of both membranal and cytoplasmic marker enzymes. Fluorescence photobleaching recovery was employed to study the lateral mobility of the lipid probe NBD-phosphatidylethanolamine and of membrane glycoproteins that bind succinylated concanavalin A. The mobile fractions of both probes were higher in aged cultures, while the lateral diffusion coefficients were lower. To further demonstrate the dependence of the above parameters on the cellular lipid composition, we have manipulated the lipid composition of old cultures by treatments with liposomes (small unilamellar vesicles) of specific compositions. Treatments which reversed the lipid composition towards that of young (5-6-day-old) cultures caused a concomitant reversal of the measured biochemical and biophysical parameters to the values observed in young cultures. These findings suggest that alterations in the organization and mobility of cell membrane constituents are involved in mediating changes in cellular functions. In view of our previous findings on cultures of rat-heart myocytes (Yechiel, E., Barenholz, Y. and Henis, Y.I. (1985) J. Biol. Chem. 260, 9132-9136), it appears that the modulation of cellular properties through the membrane lipid composition may be a general phenomenon in many cell types.
KW - (Rat fibroblast)
KW - Aging
KW - Fluorescence photobleaching recovery
KW - Lateral diffusion
KW - Lipid composition
UR - http://www.scopus.com/inward/record.url?scp=0022469602&partnerID=8YFLogxK
U2 - 10.1016/0005-2736(86)90322-6
DO - 10.1016/0005-2736(86)90322-6
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AN - SCOPUS:0022469602
SN - 0005-2736
VL - 859
SP - 95
EP - 104
JO - BBA - Biomembranes
JF - BBA - Biomembranes
IS - 1
ER -