Differentiation-dependent activation of the human intestinal alkaline phosphatase promoter by HNF-4 in intestinal cells

2005 ◽  
Vol 289 (2) ◽  
pp. G220-G226 ◽  
Author(s):  
Line Olsen ◽  
Simon Bressendorff ◽  
Jesper T. Troelsen ◽  
Jorgen Olsen
Keyword(s):  
Alkaline Phosphatase ◽  
Binding Site ◽  
Promoter Sequence ◽  
Computer Assisted ◽  
Intestinal Epithelial ◽  
Intestinal Alkaline Phosphatase ◽  
Cis Element ◽  
Nuclear Extracts ◽  
Brush Border Enzyme ◽  
Translational Start

The intestinal alkaline phosphatase gene ( ALPI) encodes a digestive brush-border enzyme, which is highly upregulated during small intestinal epithelial cell differentiation. To identify new putative promoter motifs responsible for the regulation of ALPI expression during differentiation of the enterocytes, we have conducted a computer-assisted cis-element search of the proximal human ALPI promoter sequence. A putative recognition site for the transcription factor hepatocyte nuclear factor (HNF)-4 was predicted at the positions from −94 to −82 in relation to the translational start site. The ability of HNF-4α to stimulate the expression from the ALPI promoter was investigated in the nonintestinal Hela cell line. Cotransfection with an HNF-4α expression vector demonstrated a direct activation of the ALPI promoter through this −94 to −82 element. EMSA showed that HNF-4α from nuclear extracts of differentiated intestinal epithelial cells (Caco-2) bound with high affinity to the predicted HNF-4 binding site. A 521 bp promoter fragment containing the HNF-4 binding site demonstrated a differentiation-dependent increase in promoter activity in Caco-2 cells. The presence of the HNF-4 binding site was necessary for this increase to occur.

Pattern of rat intestinal brush-border enzyme gene expression changes with epithelial growth state

1995 ◽  
Vol 269 (2) ◽  
pp. C385-C391 ◽  
Author(s):  
R. A. Hodin ◽  
S. M. Chamberlain ◽  
S. Meng
Keyword(s):  
Gene Expression ◽  
Alkaline Phosphatase ◽  
Brush Border ◽  
Longitudinal Axis ◽  
Mrna Levels ◽  
Intestinal Alkaline Phosphatase ◽  
Enzyme Gene ◽  
Growth State ◽  
Brush Border Enzyme ◽  
Epithelial Growth

Enterocyte growth and differentiation occur simultaneously within the epithelium, but little is known regarding any relationship between these two processes. Four rat models of small intestinal epithelial hypo- and hyperplasia (neonatal ontogeny, fasting/refeeding, hypo-/hyperthyroidism, and bombesin treatment) were used to study the regulation of enterocyte gene expression in relation to epithelial growth state. Mucosal scrapings, as well as crypt and villus cell populations, were subjected to Northern blot analyses using radiolabeled cDNA probes corresponding to lactase, intestinal alkaline phosphatase, villin, ornithine decarboxylase (ODC), and the actin control. In all four models, the hypoplastic (atrophic) condition is characterized by high levels of lactase and low levels of the 3.0-kb intestinal alkaline phosphatase mRNA, whereas under hyperplastic conditions this pattern is reversed. The changes in intestinal alkaline phosphatase and lactase are qualitatively similar along the longitudinal axis of the intestine and are proportional to the degree of hyperplasia, as verified by ODC mRNA levels. Furthermore, the crypt-villus axis of differentiation is maintained regardless of epithelial growth state. In conclusion, the pattern of brush-border enzyme gene expression changes as a function of epithelial growth state, indicating a previously unrecognized degree of plasticity to the state of enterocyte differentiation.

Differential regulation of intestinal alkaline phosphatase gene expression by Cdx1 and Cdx2

2005 ◽  
Vol 289 (2) ◽  
pp. G285-G290 ◽  
Author(s):  
Fuad Alkhoury ◽  
Madhu S. Malo ◽  
Moushumi Mozumder ◽  
Golam Mostafa ◽  
Richard A. Hodin
Keyword(s):  
Alkaline Phosphatase ◽  
Transcription Factors ◽  
Mrna Expression ◽  
Marker Gene ◽  
Human Colon ◽  
Luciferase Reporter ◽  
Intestinal Alkaline Phosphatase ◽  
Human Colon Cancer ◽  
Response Element ◽  
Cis Element

We have examined the role that the caudal-related homeobox transcription factors Cdx1 and Cdx2 play in activating the enterocyte differentiation marker gene intestinal alkaline phosphatase ( IAP). Human colon cancer Caco-2 cells were transiently transfected with Cdx1 and/or Cdx2, and semiquantitative RT-PCR was used to study the effects on IAP mRNA expression. Transfections with a variety of IAP-luciferase reporter constructs were used to identify a Cdx response element located within the human IAP gene promoter. Protein-DNA interactions were examined by EMSA. Results showed that Cdx1 markedly induced IAP mRNA expression, whereas Cdx2 did not, and, in fact, inhibited the Cdx1 effects. Functional analysis revealed that Cdx1 transactivates (fourfold, P < 0.05) the IAP promoter through a novel Cdx response element (GTTTAGA) located between −2369 and −2375 upstream of the translational start site. EMSA showed that both Cdx1 and Cdx2 could bind to the cis element, but in cotransfection experiments, Cdx2 inhibited the Cdx1 effects by ∼50%. Thus we have identified a previously unrecognized interaction between two important gut transcription factors, Cdx1 and Cdx2, in the context of IAP gene regulation. Cdx1 activates the IAP gene via a novel cis element, whereas Cdx2 inhibits the Cdx1 effects.

The effect of intestinal alkaline phosphatase on intestinal epithelial cells, macrophages and chronic colitis in mice

Life Sciences ◽  
2014 ◽  
Vol 100 (2) ◽  
pp. 118-124 ◽  
Author(s):  
Changhyun Lee ◽  
Jaeyoung Chun ◽  
Sung Wook Hwang ◽  
Seung Joo Kang ◽  
Jong Pil Im ◽  
...  
Keyword(s):  
Alkaline Phosphatase ◽  
Epithelial Cells ◽  
Intestinal Epithelial Cells ◽  
Intestinal Epithelial ◽  
Chronic Colitis ◽  
Intestinal Alkaline Phosphatase

Enterocyte differentiation marker intestinal alkaline phosphatase is a target gene of the gut-enriched Krüppel-like factor

2004 ◽  
Vol 286 (1) ◽  
pp. G23-G30 ◽  
Author(s):  
Brian F. Hinnebusch ◽  
Aleem Siddique ◽  
J. Welles Henderson ◽  
Madhu S. Malo ◽  
Wenying Zhang ◽  
...  
Keyword(s):  
Alkaline Phosphatase ◽  
Protein Interactions ◽  
Target Gene ◽  
Marker Gene ◽  
Luciferase Reporter ◽  
Intestinal Alkaline Phosphatase ◽  
Human Colon Cancer ◽  
Cis Element ◽  
Differentiation Marker ◽  
Enterocyte Differentiation

We have examined the role that the transcription factor gut-enriched Krüppel-like factor (KLF4 or GKLF) plays in activating the enterocyte differentiation marker gene intestinal alkaline phosphatase (IAP). A yeast one-hybrid screen was used to identify proteins interacting with a previously identified cis-element (IF-III) located within the human IAP gene promoter. DNA-protein interactions were determined by using EMSA. Northern blot analysis was used to study RNA expression in human colon cancer RKO cells engineered to overexpress KLF4. Transient transfections with IAP-luciferase reporter constructs were used to characterize the mechanisms by which KLF4 activates IAP transcription. The yeast one-hybrid screen and EMSA identified KLF4 as binding to IF-III. RKO cells induced to overexpress KLF4 demonstrated a corresponding dose-dependent increase in IAP expression, and EMSA with nuclear extract from these cells confirmed that KLF4 binds to the IF-III element. Transient transfections revealed that KLF4 transactivated the IAP gene largely via a critical segment in the IAP promoter that includes the IF-III cis-element. Mutant KLF4 constructs failed to fully activate IAP. We have identified the enterocyte differentiation marker IAP as a KLF4 target gene. IAP transactivation by KLF4 is likely mediated through a critical region located within the proximal IAP promoter region.

scholarly journals Targeting the Intestinal Barrier to Prevent Gut-Derived Inflammation and Disease: A Role for Intestinal Alkaline Phosphatase

2021 ◽  
pp. 1-11
Author(s):  
Florian Kühn ◽  
Ruifeng Duan ◽  
Matthias Ilmer ◽  
Ulrich Wirth ◽  
Fatemeh Adiliaghdam ◽  
...  
Keyword(s):  
Alkaline Phosphatase ◽  
Intestinal Barrier ◽  
Multiple Organ ◽  
Intestinal Alkaline Phosphatase ◽  
Alkaline Phosphatases ◽  
Gut Barrier Function ◽  
Proximal Small Intestine ◽  
Therapeutic Value ◽  
Organ Systems ◽  
Brush Border Enzyme

<b><i>Background:</i></b> Intestinal alkaline phosphatase (IAP) as a tissue-specific isozyme of alkaline phosphatases is predominantly produced by enterocytes in the proximal small intestine. In recent years, an increasing number of pathologies have been identified to be associated with an IAP deficiency, making it very worthwhile to review the various roles, biological functions, and potential therapeutic aspects of IAP. <b><i>Summary:</i></b> IAP primarily originates and acts in the intestinal tract but affects other organs through specific biological axes related to its fundamental roles such as promoting gut barrier function, dephosphorylation/detoxification of lipopolysaccharides (LPS), and regulation of gut microbiota. <b><i>Key Messages:</i></b> Numerous studies reporting on the different roles and the potential therapeutic value of IAP across species have been published during the last decade. While IAP deficiency is linked to varying degrees of physiological dysfunctions across multiple organ systems, the supplementation of IAP has been proven to be beneficial in several translational and clinical studies. The increasing evidence of the salutary functions of IAP underlines the significance of the naturally occurring brush border enzyme.

Intestinal alkaline phosphatase contributes to the reduction of severe intestinal epithelial damage

2010 ◽  
Vol 633 (1-3) ◽  
pp. 71-77 ◽  
Author(s):  
Marianne Bol-Schoenmakers ◽  
Daniëlle Fiechter ◽  
Willem Raaben ◽  
Ine Hassing ◽  
Rob Bleumink ◽  
...  
Keyword(s):  
Alkaline Phosphatase ◽  
Intestinal Epithelial ◽  
Intestinal Alkaline Phosphatase ◽  
Epithelial Damage
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