Effect of leptin on intestinal apolipoprotein AIV in response to lipid feeding

2001 ◽  
Vol 281 (3) ◽  
pp. R753-R759 ◽  
Author(s):  
Takashi Doi ◽  
Min Liu ◽  
Randy J. Seeley ◽  
Stephen C. Woods ◽  
Patrick Tso
Keyword(s):  
Small Intestine ◽  
Epithelial Cells ◽  
Intestinal Epithelial Cells ◽  
Regional Distribution ◽  
Intestinal Epithelial ◽  
Lipid Infusion ◽  
Intraduodenal Infusion ◽  
Crypt Cells

We determined apolipoprotein AIV (apo AIV) content in intestinal epithelial cells using immunohistochemistry when leptin was administered intravenously. Most of the apo AIV immunoreactivity in the untreated intestine was located in the villous cells as opposed to the crypt cells. Regional distribution of apo AIV immunostaining revealed low apo AIV content in the duodenum and high content in the jejunum that gradually decreases caudally toward the ileum. Intraduodenal infusion of lipid (4 h) significantly increased apo AIV immunoreactivity in the jejunum and ileum. Simultaneous intravenous leptin infusion plus duodenal lipid infusion markedly suppressed apo AIV immunoreactivity. Duodenal lipid infusion increased plasma apo AIV significantly (measured by ELISA), whereas simultaneous leptin infusion attenuated the increase. These findings suggest that leptin may regulate circulating apo AIV by suppressing apo AIV synthesis in the small intestine.

scholarly journals DES2 protein is responsible for phytoceramide biosynthesis in the mouse small intestine

2004 ◽  
Vol 379 (3) ◽  
pp. 687-695 ◽  
Author(s):  
Fumio OMAE ◽  
Masao MIYAZAKI ◽  
Ayako ENOMOTO ◽  
Minoru SUZUKI ◽  
Yusuke SUZUKI ◽  
...  
Keyword(s):  
Small Intestine ◽  
Epithelial Cells ◽  
Intestinal Epithelial ◽  
Vitro Assay ◽  
Peptide Antibody ◽  
Mouse Small Intestine ◽  
Mrna Content ◽  
Crypt Cells

The C-4 hydroxylation of sphinganine and dihydroceramide is a rate-limiting reaction in the biosynthesis of phytosphingolipids. Mouse DES1 (MDES1) cDNA homologous to the Drosophila melanogaster degenerative spermatocyte gene-1 (des-1) cDNA leads to sphingosine Δ4-desaturase activity, and another mouse homologue, MDES2, has bifunctional activity, producing C-4 hydroxysphinganine and Δ4-sphingenine in yeast [Ternes, Franke, Zahringer, Sperling and Heinz (2002) J. Biol. Chem. 277, 25512–25518]. Here, we report the characterization of mouse DES2 (MDES2) using an in vitro assay with a homogenate of COS-7 cells transfected with MDES2 cDNA and N-octanoyl-sphinganine and sphinganine as substrates. MDES2 protein prefers dihydroceramide as a substrate to sphinganine, and exhibits dihydroceramide Δ4-desaturase and C-4 hydroxylase activities. MDES2 mRNA content was high in the small intestine and abundant in the kidney. In situ hybridization detected signals of MDES2 mRNA in the crypt cells. Immunohistochemistry using an anti-MDES2 peptide antibody stained the crypt cells and the adjacent epithelial cells. These results suggest that MDES2 is the dihydroceramide C-4 hydroxylase responsible for the biosynthesis of enriched phytosphingoglycolipids in the microvillous membranes of intestinal epithelial cells.

scholarly journals Surface-membrane biogenesis in rat intestinal epithelial cells at different stages of maturation

1980 ◽  
Vol 192 (1) ◽  
pp. 133-144 ◽  
Author(s):  
A Quaroni ◽  
K Kirsch ◽  
A Herscovics ◽  
K J Isselbacher
Keyword(s):  
Epithelial Cells ◽  
Intestinal Epithelial Cells ◽  
Surface Membrane ◽  
Basal Membrane ◽  
Similar Process ◽  
Intestinal Epithelial ◽  
Protein Patterns ◽  
Luminal Membrane ◽  
Membrane Components ◽  
Crypt Cells

The biosynthesis of membrane proteins and glycoproteins has been studied in rat intestinal crypt and villus cells by measuring the incorporation of L-[5,6-3H] fucose, D-[2-3H] mannose and L-[3,4,5-3H] leucine, given intraperitoneally, into Golgi, lateral-basal and luminal membranes. Incorporation of leucine and mannose was approximately equal in crypt and villus cells, whereas fucose incorporation was markedly higher (3-4 times) in the differentiated villus cells. As previously reported [Quaroni, Kirsch & Weiser (1979) Biochem J. 182. 203-212] most of the fucosylated glyco-proteins synthesized in the villus cells and initially present in the Golgi and lateral-basal membranes were found re-distributed, within 3-4h of label administration, in the luminal membrane. A similar process appeared to occur in the crypt cells, where, however, only few fucose-labelled glycoproteins were identified. In contrast, most of the leucine-labelled and many mannose-labelled membrane components found in the lateral-basal membrane of both crypt and villus cells did not seen to undergo a similar re-distribution process. The fucosylated glycoproteins of the intestinal epithelial cells represent, therefore, a special class of membrane components, most of which appear with differentiation, that are selectively localized in the luminal portion of the plasmalemma. In contrast with the marked differences in protein and glycoprotein patterns between the luminal membrane of villus and crypt cells, only minor differences were found between their lateral-basal membrane components: their protein patterns on sodium dodecyl sulphate/polyacrylamide slab gels, and the patterns of fucose-, mannose- and leucine-labelled components (analysed 3-4h after label administration) were very similar. Although the minor differences detected may be of importance, it appears that most of the surface-membrane changes accompanying cell differentiation in the intestinal epithelial cells are localized in the luminal portion of their surface membrane.

scholarly journals Intectin, a Novel Small Intestine-specific Glycosylphosphatidylinositol-anchored Protein, Accelerates Apoptosis of Intestinal Epithelial Cells

2004 ◽  
Vol 279 (41) ◽  
pp. 42867-42874 ◽  
Author(s):  
Hidefumi Kitazawa ◽  
Tamao Nishihara ◽  
Tadahiro Nambu ◽  
Hitoshi Nishizawa ◽  
Masanori Iwaki ◽  
...  
Keyword(s):  
Small Intestine ◽  
Epithelial Cells ◽  
Intestinal Epithelial Cells ◽  
Intestinal Epithelial

scholarly journals Role of Intestinal Epithelial Cells in Immune Effects Mediated by Gram-Positive Probiotic Bacteria: Involvement of Toll-Like Receptors

2005 ◽  
Vol 12 (9) ◽  
pp. 1075-1084 ◽  
Author(s):  
Gabriel Vinderola ◽  
Chantal Matar ◽  
Gabriela Perdigon
Keyword(s):  
Small Intestine ◽  
B Cells ◽  
Epithelial Cells ◽  
Intestinal Epithelial Cells ◽  
Primary Cultures ◽  
Clonal Expansion ◽  
Probiotic Bacteria ◽  
Intestinal Epithelial ◽  
Toll Like Receptors

ABSTRACT The mechanisms by which probiotic bacteria exert their effects on the immune system are not completely understood, but the epithelium may be a crucial player in the orchestration of the effects induced. In a previous work, we observed that some orally administered strains of lactic acid bacteria (LAB) increased the number of immunoglobulin A (IgA)-producing cells in the small intestine without a concomitant increase in the CD4+ T-cell population, indicating that some LAB strains induce clonal expansion only of B cells triggered to produce IgA. The present work aimed to study the cytokines induced by the interaction of probiotic LAB with murine intestinal epithelial cells (IEC) in healthy animals. We focused our investigation mainly on the secretion of interleukin 6 (IL-6) necessary for the clonal expansion of B cells previously observed with probiotic bacteria. The role of Toll-like receptors (TLRs) in such interaction was also addressed. The cytokines released by primary cultures of IEC in animals fed with Lactobacillus casei CRL 431 or Lactobacillus helveticus R389 were determined. Cytokines were also determined in the supernatants of primary cultures of IEC of unfed animals challenged with different concentrations of viable or nonviable lactobacilli and Escherichia coli, previously blocked or not with anti-TLR2 and anti-TLR4. We concluded that the small intestine is the place where a major distinction would occur between probiotic LAB and pathogens. This distinction comprises the type of cytokines released and the magnitude of the response, cutting across the line that separates IL-6 necessary for B-cell differentiation, which was the case with probiotic lactobacilli, from inflammatory levels of IL-6 for pathogens.

Suppressor of cytokine signaling-2 limits intestinal growth and enterotrophic actions of IGF-I in vivo

2006 ◽  
Vol 291 (3) ◽  
pp. G472-G481 ◽  
Author(s):  
Carmen Z. Michaylira ◽  
James G. Simmons ◽  
Nicole M. Ramocki ◽  
Brooks P. Scull ◽  
Kirk K. McNaughton ◽  
...  
Keyword(s):  
Small Intestine ◽  
Epithelial Cells ◽  
Intestinal Epithelial Cells ◽  
Ex Vivo ◽  
Cytokine Signaling ◽  
Intestinal Epithelial ◽  
Growth Responses ◽  
Intestinal Growth ◽  
Igf I

Suppressors of cytokine signaling (SOCS) typically limit cytokine receptor signaling via the JAK-STAT pathway. Considerable evidence demonstrates that SOCS2 limits growth hormone (GH) action on body and organ growth. Biochemical evidence that SOCS2 binds to the IGF-I receptor (IGF-IR) supports the novel possibility that SOCS2 limits IGF-I action. The current study tested the hypothesis that SOCS2 normally limits basal or IGF-I-induced intestinal growth and limits IGF-IR signaling in intestinal epithelial cells. Intestinal growth was assessed in mice homozygous for SOCS2 gene deletion (SOCS2 null) and wild-type (WT) littermates at different ages and in response to infused IGF-I or vehicle or EGF and vehicle. The effects of SOCS2 on IGF-IR signaling were examined in ex vivo cultures of SOCS2 null and WT intestine and Caco-2 cells. Compared with WT, SOCS2 null mice showed significantly enhanced small intestine and colon growth, mucosal mass, and crypt cell proliferation and decreases in radiation-induced crypt apoptosis in jejunum. SOCS2 null mice showed significantly greater growth responses to IGF-I in small intestine and colon. IGF-I-stimulated activation of IGF-IR and downstream signaling intermediates were enhanced in the intestine of SOCS2 null mice and were decreased by SOCS2 overexpression in Caco-2 cells. SOCS2 bound directly to the endogenous IGF-IR in Caco-2 cells. The intestine of SOCS2 null mice also showed enhanced growth responses to infused EGF. We conclude that SOCS2 normally limits basal and IGF-I- and EGF-induced intestinal growth in vivo and has novel inhibitory effects on the IGF-IR tyrosine kinase pathway in intestinal epithelial cells.

scholarly journals Immunocytochemical localization of ornithine transcarbamylase in rat intestinal mucosa. Light and electron microscopic study.

1988 ◽  
Vol 36 (1) ◽  
pp. 29-35 ◽  
Author(s):  
Y Hamano ◽  
H Kodama ◽  
M Yanagisawa ◽  
Y Haraguchi ◽  
M Mori ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Small Intestine ◽  
Epithelial Cells ◽  
Light Microscopy ◽  
Intestinal Mucosa ◽  
Intestinal Epithelial Cells ◽  
Protein A ◽  
Intestinal Epithelial ◽  
Electron Microscopic ◽  
Small Intestinal

We investigated light and electron microscopic localization of ornithine transcarbamylase (OTC) in rat intestinal mucosa. In the immunoblotting assay of OTC-related protein, a single protein band with a molecular weight of about 36,500 is observed in extracts of liver and small intestinal mucosa but is not observed in those of stomach and large intestine. For light microscopy, tissue slices of the digestive system were embedded in Epon and stained by using anti-bovine OTC rabbit IgG and the immunoenzyme technique. For electron microscopy, slices of these and the liver tissues were embedded in Lowicryl K4M and stained by the protein A-gold technique. By light microscopy, the absorptive epithelial cells of duodenum, jejunum, and ileum stained positively for OTC, but stomach, large intestine, rectum, and propria mucosa of small intestine were not stained. Electron microscopy showed that gold particles representing the antigenic sites for OTC were confined to the mitochondrial matrix of hepatocytes and small intestinal epithelial cells. However, the enzyme was detected in mitochondria of neither liver endothelial cells, submucosal cells of small intestine, nor large intestinal epithelial cells. Labeling density of mitochondria in the absorptive epithelial cells of duodenum, jejunum, and ileum was about half of that in liver cells.

scholarly journals Molecular Mechanism of Stimulation of Na-K-ATPase by Leukotriene D4 in Intestinal Epithelial Cells

2021 ◽  
Vol 22 (14) ◽  
pp. 7569
Author(s):  
Niraj Nepal ◽  
Subha Arthur ◽  
Molly R. Butts ◽  
Soudamani Singh ◽  
Balasubramanian Palaniappan ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Atpase Activity ◽  
Intestinal Epithelial Cells ◽  
Intestinal Epithelial ◽  
Leukotriene D4 ◽  
Intestinal Crypt ◽  
Calphostin C ◽  
Chronic Intestinal Inflammation ◽  
Crypt Cells ◽  
Stimulation Of

Na-K-ATPase provides a favorable transcellular Na gradient required for the functioning of Na-dependent nutrient transporters in intestinal epithelial cells. The primary metabolite for enterocytes is glutamine, which is absorbed via Na-glutamine co-transporter (SN2; SLC38A5) in intestinal crypt cells. SN2 activity is stimulated during chronic intestinal inflammation, at least in part, secondarily to the stimulation of Na-K-ATPase activity. Leukotriene D4 (LTD4) is known to be elevated in the mucosa during chronic enteritis, but the way in which it may regulate Na-K-ATPase is not known. In an in vitro model of rat intestinal epithelial cells (IEC-18), Na-K-ATPase activity was significantly stimulated by LTD4. As LTD4 mediates its action via Ca-dependent protein kinase C (PKC), Ca levels were measured and were found to be increased. Phorbol 12-myristate 13-acetate (PMA), an activator of PKC, also mediated stimulation of Na-K-ATPase like LTD4, while BAPTA-AM (Ca chelator) and calphostin-C (Cal-C; PKC inhibitor) prevented the stimulation of Na-K-ATPase activity. LTD4 caused a significant increase in mRNA and plasma membrane protein expression of Na-K-ATPase α1 and β1 subunits, which was prevented by calphostin-C. These data demonstrate that LTD4 stimulates Na-K-ATPase in intestinal crypt cells secondarily to the transcriptional increase of Na-K-ATPase α1 and β1 subunits, mediated via the Ca-activated PKC pathway.

scholarly journals Changes in the synthesis of ribosomal ribonucleic acid and of poly(A)-containing ribonucleic acid during the differentiation of intestinal epithelial cells in the rat and in the chick

1980 ◽  
Vol 188 (3) ◽  
pp. 609-618 ◽  
Author(s):  
A Morrison ◽  
J W Porteous
Keyword(s):  
Epithelial Cells ◽  
Ribonucleic Acid ◽  
Vascular System ◽  
Intestinal Epithelial Cells ◽  
Intestinal Lumen ◽  
Intestinal Epithelial ◽  
Villus Cell ◽  
Turn Over ◽  
Crypt Cells

Epithelial cells were isolated from rat and chick small intestine by techniques which separated subpopulations of differentiating villus and upper crypt cells from each other and from populations of mitotically dividing lower crypt cells. Incorporation of precursors into epithelial-cell DNA, cytoplasmic rRNA and cytoplasmic poly(A)-containing RNA occurred in the lower crypt cells in vivo when precursor was supplied from the vascular system of the intestine. Incorporation of precursor into 28S and 18S rRNA continued in the upper crypt cells, but occurred to only a very slight extent (if at all) in villus cells, whereas incorporation into poly(A)-containing RNA continued (at a diminishing rate) as the differentiating cells migrated along the villi. When precursor was supplied from the intestinal lumen, its incorporation into DNA and into rRNA of crypt cells was not very different from that observed with the other mode of precursor administration, but incorporation into villus-cell poly(A)-containing RNA then occurred at essentially the same rate in all intestinal epithelial cells in vivo. Cytoplasmic poly(A)-containing RNA appeared to turn over in rat crypt cells with a half-life not exceeding 24 h; crypt-cell rRNA showed no turnover and no evidence could be found for the presence of ‘metabolic DNA’.

Functional involvement of RFVT3/SLC52A3 in intestinal riboflavin absorption

2014 ◽  
Vol 306 (2) ◽  
pp. G102-G110 ◽  
Author(s):  
Hiroki Yoshimatsu ◽  
Atsushi Yonezawa ◽  
Yoshiaki Yao ◽  
Kumiko Sugano ◽  
Shunsaku Nakagawa ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Small Intestine ◽  
Epithelial Cells ◽  
Intestinal Epithelial Cells ◽  
Biological Membrane ◽  
Transport Systems ◽  
Intestinal Epithelial ◽  
T84 Cells ◽  
Functional Involvement ◽  
Apical Membranes

Riboflavin, also known as vitamin B2, is transported across the biological membrane into various organs by transport systems. Riboflavin transporter RFVT3 is expressed in the small intestine and has been suggested to localize in the apical membranes of the intestinal epithelial cells. In this study, we investigated the functional involvement of RFVT3 in riboflavin absorption using intestinal epithelial T84 cells and mouse small intestine. T84 cells expressed RFVT3 and conserved unidirectional riboflavin transport corresponding to intestinal absorption. Apical [3H]riboflavin uptake was pH-dependent in T84 cells. This uptake was not affected by Na+ depletion at apical pH 6.0, although it was significantly decreased at apical pH 7.4. The [3H]riboflavin uptake from the apical side of T84 cells was prominently inhibited by the RFVT3 selective inhibitor methylene blue and significantly decreased by transfection of RFVT3-small-interfering RNA. In the gastrointestinal tract, RFVT3 was expressed in the jejunum and ileum. Mouse jejunal and ileal permeabilities of [3H]riboflavin were measured by the in situ closed-loop method and were significantly reduced by methylene blue. These results strongly suggest that RFVT3 would functionally be involved in riboflavin absorption in the apical membranes of intestinal epithelial cells.

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