TY - JOUR
T1 - CD36 Is Important for Chylomicron Formation and Secretion and May Mediate Cholesterol Uptake in the Proximal Intestine
AU - Nauli, Andromeda M.
AU - Nassir, Fatiha
AU - Zheng, Shuqin
AU - Yang, Qing
AU - Lo, Chun Min
AU - VonLehmden, Sarah B.
AU - Lee, Dana
AU - Jandacek, Ronald J.
AU - Abumrad, Nada A.
AU - Tso, Patrick
N1 - Funding Information:
Supported by the National Institute of Health (grants DK-56910, and DK-56863 to P Tso and DK60022 and DK33301 to N.A.), a predoctoral fellowship award from the American Heart Association, Ohio Valley Affiliate, and the National Health Research Institute scholarship for cardiovascular diseases (A.M.N.).
PY - 2006/10
Y1 - 2006/10
N2 - Background & Aims: Studies are aimed to determine the role of CD36 in intestinal lipid absorption. Methods: Knock-out (KO) and wild-type (WT) lymph fistula mice were used to study fatty acids (FA) and cholesterol uptake, and chylomicron formation and secretion. Uptake of FA and cholesterol was studied by using sucrose polybehenate and fecal dual isotope methods, respectively. Results: The CD36 KO exhibited significant accumulation of dietary cholesterol in the intestinal lumen at the end of 6-hour lipid infusion and significant reduction of dietary cholesterol transport into the lymph. Fecal dual isotope studies, however, did not show any significant difference in cholesterol uptake, suggesting that given sufficient time, the KO intestine could compensate for the reduced cholesterol uptake observed in the acute lymph fistula studies. Recovery of dietary FA in the intestinal lumen was comparable between WT and KO, consistent with the sucrose polybehenate study. However, the KO mice accumulated more, albeit not significantly, dietary triacylglycerols in the intestine, followed by a significant reduction in lymphatic transport. The ratio of intestinal dietary triacylglycerols to FA was not higher in WT than KO, arguing against impaired lipid esterification. It is rather a deficiency in the formation and secretion of chylomicrons, as supported by the significantly less apolipoprotein B-48 and the smaller, albeit not significantly, lipoprotein particles secreted into the lymph of the KO. Conclusions: CD36 may play an important role in chylomicron formation and secretion and may also facilitate cholesterol uptake in the proximal intestine.
AB - Background & Aims: Studies are aimed to determine the role of CD36 in intestinal lipid absorption. Methods: Knock-out (KO) and wild-type (WT) lymph fistula mice were used to study fatty acids (FA) and cholesterol uptake, and chylomicron formation and secretion. Uptake of FA and cholesterol was studied by using sucrose polybehenate and fecal dual isotope methods, respectively. Results: The CD36 KO exhibited significant accumulation of dietary cholesterol in the intestinal lumen at the end of 6-hour lipid infusion and significant reduction of dietary cholesterol transport into the lymph. Fecal dual isotope studies, however, did not show any significant difference in cholesterol uptake, suggesting that given sufficient time, the KO intestine could compensate for the reduced cholesterol uptake observed in the acute lymph fistula studies. Recovery of dietary FA in the intestinal lumen was comparable between WT and KO, consistent with the sucrose polybehenate study. However, the KO mice accumulated more, albeit not significantly, dietary triacylglycerols in the intestine, followed by a significant reduction in lymphatic transport. The ratio of intestinal dietary triacylglycerols to FA was not higher in WT than KO, arguing against impaired lipid esterification. It is rather a deficiency in the formation and secretion of chylomicrons, as supported by the significantly less apolipoprotein B-48 and the smaller, albeit not significantly, lipoprotein particles secreted into the lymph of the KO. Conclusions: CD36 may play an important role in chylomicron formation and secretion and may also facilitate cholesterol uptake in the proximal intestine.
UR - http://www.scopus.com/inward/record.url?scp=33749349147&partnerID=8YFLogxK
U2 - 10.1053/j.gastro.2006.08.012
DO - 10.1053/j.gastro.2006.08.012
M3 - Article
C2 - 17030189
AN - SCOPUS:33749349147
SN - 0016-5085
VL - 131
SP - 1197
EP - 1207
JO - Gastroenterology
JF - Gastroenterology
IS - 4
ER -