Proline Absorption and SGK1 Expression are Inhibited in Intestinal Tis7 Transgenic Mice
Background/Aims: Expression of the transcriptional co-regulator tis7 is markedly increased in the adaptive small intestine in a mouse model of short bowel syndrome. Transgenic mice with enterocytic overexpression of tis7 (tis7tg) have accelerated triglyceride absorption, with increased adiposity yet...
| Main Authors: | , , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Cell Physiol Biochem Press GmbH & Co KG
2016-04-01
|
| Series: | Cellular Physiology and Biochemistry |
| Subjects: | |
| Online Access: | http://www.karger.com/Article/FullText/443094 |
| _version_ | 1818921566842388480 |
|---|---|
| author | Jianyun Lu Amy M. Garcia Taylor Geisman Derek Wakeman Brad W. Warner Elzbieta A. Swietlicki Marc S. Levin Deborah C. Rubin |
| author_facet | Jianyun Lu Amy M. Garcia Taylor Geisman Derek Wakeman Brad W. Warner Elzbieta A. Swietlicki Marc S. Levin Deborah C. Rubin |
| author_sort | Jianyun Lu |
| collection | DOAJ |
| description | Background/Aims: Expression of the transcriptional co-regulator tis7 is markedly increased in the adaptive small intestine in a mouse model of short bowel syndrome. Transgenic mice with enterocytic overexpression of tis7 (tis7tg) have accelerated triglyceride absorption, with increased adiposity yet reduced skeletal muscle mass. To further explore this phenotype, we examined whether tis7 also regulates amino acid and carbohydrate absorption. Methods: Small intestinal glucose and amino acid uptake were quantified in wild type (WT) and tis7tg mice. Amino acid transporter expression was assessed by qRT-PCR and immunoblot. Apical cell surface transporter expression was quantified by cell surface biotinylation. Results: Active glucose uptake rates were unchanged. Uptake of proline but not leucine was significantly reduced in tis7tg vs. WT jejunum. Expression of serum and glucocorticoid-induced kinase 1 (SGK1), a solute carrier activator, was inhibited in tis7tg jejunum. Apical membrane expression of the proline transporter SLC6A20 was reduced in tis7tg jejunum. Conclusions: Tis7 overexpression in enterocytes inhibits proline uptake, associated with decreased expression of activated SGK1 and reduced cell surface expression of SLC6A20. Consistent with the observed tis7tg phenotype, tis7 overexpression increases triglyceride absorption but has adverse effects on the uptake of selected amino acids. Tis7 has pleiotropic effects on nutrient absorption. |
| first_indexed | 2024-12-20T01:39:41Z |
| format | Article |
| id | doaj.art-96d0636d34f74c10a4615217efd9ded0 |
| institution | Directory Open Access Journal |
| issn | 1015-8987 1421-9778 |
| language | English |
| last_indexed | 2024-12-20T01:39:41Z |
| publishDate | 2016-04-01 |
| publisher | Cell Physiol Biochem Press GmbH & Co KG |
| record_format | Article |
| series | Cellular Physiology and Biochemistry |
| spelling | doaj.art-96d0636d34f74c10a4615217efd9ded02022-12-21T19:57:55ZengCell Physiol Biochem Press GmbH & Co KGCellular Physiology and Biochemistry1015-89871421-97782016-04-013841532154310.1159/000443094443094Proline Absorption and SGK1 Expression are Inhibited in Intestinal Tis7 Transgenic MiceJianyun LuAmy M. GarciaTaylor GeismanDerek WakemanBrad W. WarnerElzbieta A. SwietlickiMarc S. LevinDeborah C. RubinBackground/Aims: Expression of the transcriptional co-regulator tis7 is markedly increased in the adaptive small intestine in a mouse model of short bowel syndrome. Transgenic mice with enterocytic overexpression of tis7 (tis7tg) have accelerated triglyceride absorption, with increased adiposity yet reduced skeletal muscle mass. To further explore this phenotype, we examined whether tis7 also regulates amino acid and carbohydrate absorption. Methods: Small intestinal glucose and amino acid uptake were quantified in wild type (WT) and tis7tg mice. Amino acid transporter expression was assessed by qRT-PCR and immunoblot. Apical cell surface transporter expression was quantified by cell surface biotinylation. Results: Active glucose uptake rates were unchanged. Uptake of proline but not leucine was significantly reduced in tis7tg vs. WT jejunum. Expression of serum and glucocorticoid-induced kinase 1 (SGK1), a solute carrier activator, was inhibited in tis7tg jejunum. Apical membrane expression of the proline transporter SLC6A20 was reduced in tis7tg jejunum. Conclusions: Tis7 overexpression in enterocytes inhibits proline uptake, associated with decreased expression of activated SGK1 and reduced cell surface expression of SLC6A20. Consistent with the observed tis7tg phenotype, tis7 overexpression increases triglyceride absorption but has adverse effects on the uptake of selected amino acids. Tis7 has pleiotropic effects on nutrient absorption.http://www.karger.com/Article/FullText/443094Amino acid absorptionTis7/IFRD1Short bowel syndromeIntestineAdaptation |
| spellingShingle | Jianyun Lu Amy M. Garcia Taylor Geisman Derek Wakeman Brad W. Warner Elzbieta A. Swietlicki Marc S. Levin Deborah C. Rubin Proline Absorption and SGK1 Expression are Inhibited in Intestinal Tis7 Transgenic Mice Cellular Physiology and Biochemistry Amino acid absorption Tis7/IFRD1 Short bowel syndrome Intestine Adaptation |
| title | Proline Absorption and SGK1 Expression are Inhibited in Intestinal Tis7 Transgenic Mice |
| title_full | Proline Absorption and SGK1 Expression are Inhibited in Intestinal Tis7 Transgenic Mice |
| title_fullStr | Proline Absorption and SGK1 Expression are Inhibited in Intestinal Tis7 Transgenic Mice |
| title_full_unstemmed | Proline Absorption and SGK1 Expression are Inhibited in Intestinal Tis7 Transgenic Mice |
| title_short | Proline Absorption and SGK1 Expression are Inhibited in Intestinal Tis7 Transgenic Mice |
| title_sort | proline absorption and sgk1 expression are inhibited in intestinal tis7 transgenic mice |
| topic | Amino acid absorption Tis7/IFRD1 Short bowel syndrome Intestine Adaptation |
| url | http://www.karger.com/Article/FullText/443094 |
| work_keys_str_mv | AT jianyunlu prolineabsorptionandsgk1expressionareinhibitedinintestinaltis7transgenicmice AT amymgarcia prolineabsorptionandsgk1expressionareinhibitedinintestinaltis7transgenicmice AT taylorgeisman prolineabsorptionandsgk1expressionareinhibitedinintestinaltis7transgenicmice AT derekwakeman prolineabsorptionandsgk1expressionareinhibitedinintestinaltis7transgenicmice AT bradwwarner prolineabsorptionandsgk1expressionareinhibitedinintestinaltis7transgenicmice AT elzbietaaswietlicki prolineabsorptionandsgk1expressionareinhibitedinintestinaltis7transgenicmice AT marcslevin prolineabsorptionandsgk1expressionareinhibitedinintestinaltis7transgenicmice AT deborahcrubin prolineabsorptionandsgk1expressionareinhibitedinintestinaltis7transgenicmice |