Impact of murine intestinal apolipoprotein A-IV expression on regional lipid absorption, gene expression, and growth

ApoA-IV modulates the secretory trafficking of apoB and the size of triglyceride-rich lipoproteins

“…Because the intestine possesses a large reserve capacity for lipid absorption ( 52,53 ), it is possible that these animals were not given a big enough lipid challenge to discern an effect of apoA-IV deletion or overexpression on dietary fat absorption effi ciency. In this regard, we recently reported that although fat balance and lymph duct cannulation studies in wild-type and apoA-IV knockout mice found no effect of apoA-IV on total dietary fat absorption, lipid transport studies using everted gut sacs revealed that apoA-IV facilitates TG transport in the proximal gut ( 54 ). These data establish that the ability of apoA-IV to facilitate TG absorption at the cellular level is in fact discernible at the suborgan level but is masked in the intact animal by the functional redundancy of the small bowel.…”

Apolipoprotein A-IV: a protein intimately involved in metabolism

“…Lu and colleagues proposed that in the newborn piglet, as well as in stably transfected IPEC-1 cells, elevated expression of apoA-IV greatly enhanced fat absorption by facilitating the formation of larger chylomicron particles ( 73,(75)(76)(77). More recently, Weinberg and Simon provided some evidence from KO mice that apoA-IV is important in regional intestinal lipid absorption and is associated with related changes in gene expression ( 79 ).…”

Using primary murine intestinal enteroids to study dietary TAG absorption, lipoprotein synthesis, and the role of apoC-III in the intestine

“…Dietary TAG is absorbed from a proximal-to-distal gradient along the length of the small intestine (29)(30)(31)(32). Correspondingly, there is a gradient of terminally differentiated enterocytes responsible for TAG absorption, as well as a gradient of apolipoprotein expression.…”