Eresheim C, Plieschnig J, Ivessa NE, Schneider WJ, Hermann M. Expression of microsomal triglyceride transfer protein in lipoprotein-synthesizing tissues of the developing chicken embryo.
Biochimie 2014;
101:67-74. [PMID:
24394625 PMCID:
PMC4008936 DOI:
10.1016/j.biochi.2013.12.020]
[Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2013] [Accepted: 12/21/2013] [Indexed: 12/01/2022]
Abstract
In contrast to mammals, in the chicken major sites of lipoprotein synthesis and secretion are not only the liver and intestine, but also the kidney and the embryonic yolk sac. Two key components in the assembly of triglyceride-rich lipoproteins are the microsomal triglyceride transfer protein (MTP) and apolipoprotein B (apoB). We have analyzed the expression of MTP in the embryonic liver, small intestine, and kidney, and have studied the expression of MTP in, and the secretion of apoB from, the developing yolk sac (YS). Transcript and protein levels of MTP increase during embryogenesis in YS, liver, kidney, and small intestine, and decrease in YS, embryonic liver, and kidney after hatching. In small intestine, the MTP mRNA level rises sharply during the last trimester of embryo development (after day 15), while MTP protein is detectable only after hatching (day 21). In the YS of 15- and 20-day old embryos, apoB secretion was detected by pulse-chase metabolic radiolabeling experiments and subsequent immunoprecipitation. Taken together, our data reveal the importance of coordinated production of MTP and apoB in chicken tissues capable of secreting triglyceride-rich lipoproteins even before hatching.
MTP is expressed in liver, small intestine, and kidney of chicken embryos.
MTP is expressed in the chicken yolk sac.
ApoB is secreted from the chicken yolk sac.
Embryonic tissues contribute to the lipoprotein pool of the developing chick.
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