TY - JOUR
T1 - Vitamin A trafficking in Caco-2 cells stably transfected with cellular retinol binding proteins
AU - Lissoos, T. W.
AU - Davis, A. E.
AU - Levin, M. S.
PY - 1995
Y1 - 1995
N2 - During intestinal vitamin A absorption, retinol is esterified by long- chain fatty acids and secreted in chylomicron particles. Stable transfectants of the human intestinal Caco-2 cell line overexpressing cellular retinol binding protein II (CRBP II) or coexpressing CRBP II and CRBP were established to study their role in intestinal vitamin A trafficking. Compared with control cell lines, retinol uptake increased up to twofold by overexpression of CRBP II and up to 2.9-fold by coexpression of CRBP and CRBP II. Retinyl ester synthesis was increased proportionate to the increase in retinol absorption in all cell lines. Retinyl ester secretion was directly correlated with retinyl ester synthesis in control and CRBP II-transfected cell lines. However, transfection with CRBP increased the proportion secreted. Expression of CRBP and CRBP II also affected the polarity of retinyl ester secretion by increasing the proportion secreted basolaterally. Thus these studies provide evidence that intestinal retinol uptake, retinyl ester synthesis, and retinyl ester secretion are correlated with levels of CRBP and CRBP II and that the effects of CRBP on retinyl ester secretion can be distinguished from those of CRBP II.
AB - During intestinal vitamin A absorption, retinol is esterified by long- chain fatty acids and secreted in chylomicron particles. Stable transfectants of the human intestinal Caco-2 cell line overexpressing cellular retinol binding protein II (CRBP II) or coexpressing CRBP II and CRBP were established to study their role in intestinal vitamin A trafficking. Compared with control cell lines, retinol uptake increased up to twofold by overexpression of CRBP II and up to 2.9-fold by coexpression of CRBP and CRBP II. Retinyl ester synthesis was increased proportionate to the increase in retinol absorption in all cell lines. Retinyl ester secretion was directly correlated with retinyl ester synthesis in control and CRBP II-transfected cell lines. However, transfection with CRBP increased the proportion secreted. Expression of CRBP and CRBP II also affected the polarity of retinyl ester secretion by increasing the proportion secreted basolaterally. Thus these studies provide evidence that intestinal retinol uptake, retinyl ester synthesis, and retinyl ester secretion are correlated with levels of CRBP and CRBP II and that the effects of CRBP on retinyl ester secretion can be distinguished from those of CRBP II.
UR - http://www.scopus.com/inward/record.url?scp=0028963539&partnerID=8YFLogxK
U2 - 10.1152/ajpgi.1995.268.2.g224
DO - 10.1152/ajpgi.1995.268.2.g224
M3 - Article
C2 - 7864119
AN - SCOPUS:0028963539
VL - 268
SP - G224-G231
JO - American Journal of Physiology - Gastrointestinal and Liver Physiology
JF - American Journal of Physiology - Gastrointestinal and Liver Physiology
SN - 0193-1857
IS - 2 31-2
ER -