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Expression of the Sodium‐neutral amino acid exchanger ASCT2 along the small intestinal crypt‐villus axis in the formula‐fed neonatal pig
Author(s) -
Yang Chengbo,
Fan Ming
Publication year - 2008
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.22.1_supplement.869.14
Subject(s) - crypt , enterocyte , brush border , chemistry , jejunum , ileum , andrology , cell , apical membrane , intestinal villus , messenger rna , amino acid , villin , microbiology and biotechnology , biology , small intestine , biochemistry , endocrinology , actin , membrane , gene , medicine , vesicle
The sodium‐neutral amino acid (AA) exchanger ASCT2 gene expressesATB0 protein responsible for the exchange of gut luminal neutral AAacross the apical membrane. The study was to quantify the ASCT2mRNA and protein expression along the jejunal crypt‐villus axis with six Yorkshiregilts at 14–16 d of age fed a milk‐based liquid formula. Threeepithelial cell fractions, representing cells from the uppervillus, the middle villus and the crypt regions, were sequentiallyisolated, with cell viability of 92–95% as assessed bytrypan blue exclusion, along the crypt‐villus axis from theentire jejunum by the distended sac method. Real time RT‐PCR analyses (SmartCycler using SYBRGreen‐I detection kit) revealed a linear decrease (P<0.05)in the ASCT2 mRNA level from the crypt cell to the upper villus cell with β‐actin as thehouse‐keeping control. No significant differences ( P >0.05) were observed in ASCT2 protein abundance in cellular homogenate, soluble, and brush border membrane among the cell fractions. These results suggest that neonatal pig enterocytes express ATB0 in the small intestinal enterocyte during the entire process of the cell proliferation and differentiation and the expression of ATB0 is not only regulated at transcriptional level but also at the post transcriptional levels. Supported by NSERC Discovery Program.