PMID- 20430871
OWN - NLM
STAT- MEDLINE
DCOM- 20100712
LR  - 20211020
IS  - 1522-1547 (Electronic)
IS  - 0193-1857 (Print)
IS  - 0193-1857 (Linking)
VI  - 299
IP  - 1
DP  - 2010 Jul
TI  - The apical (hPepT1) and basolateral peptide transport systems of Caco-2 cells are 
      regulated by AMP-activated protein kinase.
PG  - G136-43
LID - 10.1152/ajpgi.00014.2010 [doi]
AB  - The effect of 5-aminoimidazole-4-carboxamide-ribonucleoside (AICAR) activation of 
      the AMP-activated protein kinase (AMPK) on the transport of the model 
      radiolabeled dipeptide [(3)H]-D-Phe-L-Gln was investigated in the human 
      epithelial colon cancer cell line Caco-2. Uptake and transepithelial fluxes of 
      [(3)H]-D-Phe-L-Gln were carried out in differentiated Caco-2 cell monolayers, and 
      hPepT1 and glucose transporter 2 (GLUT2) protein levels were quantified by 
      immunogold electron microscopy. AICAR treatment of Caco-2 cells significantly 
      inhibited apical [(3)H]-D-Phe-L-Gln uptake, matched by a decrease in brush-border 
      membrane hPepT1 protein but with a concomitant increase in the facilitated 
      glucose transporter GLUT2. A restructuring of the apical brush-border membrane 
      was seen by electron microscopy. The hPepT1-mediated transepithelial (A-to-B) 
      peptide flux across the Caco-2 monolayers showed no significant alteration in 
      AICAR-treated cells. The electrical resistance in the AICAR-treated monolayers 
      was significantly higher compared with control cells. Inhibition of the 
      sodium/hydrogen exchanger 3 (NHE3) had an additive effect to AICAR, suggesting 
      that the AMPK effect is not via NHE3. Fluorescence measurement of intracellular 
      pH showed no reduction in the proton gradient driving PepT1-mediated apical 
      uptake. The reduction in apical hPepT1 protein and dipeptide uptake after AICAR 
      treatment in Caco-2 cells demonstrates a regulatory effect of AMPK on hPepT1, 
      along with an influence on both the microvilli and tight junction structures. The 
      absence of an associated reduction in transepithelial peptide movement implies an 
      additional stimulatory effect of AICAR on the basolateral peptide transport 
      system in these cells. These results provide a link between the hPepT1 
      transporter and the metabolic state of this model enterocyte.
FAU - Pieri, Myrtani
AU  - Pieri M
AD  - School of Life Sciences, Oxford Brookes University, Headington, Oxford OX3 0BP, 
      UK.
FAU - Christian, Helen C
AU  - Christian HC
FAU - Wilkins, Robert J
AU  - Wilkins RJ
FAU - Boyd, C A R
AU  - Boyd CA
FAU - Meredith, David
AU  - Meredith D
LA  - eng
GR  - Cancer Research UK/United Kingdom
GR  - Wellcome Trust/United Kingdom
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20100429
PL  - United States
TA  - Am J Physiol Gastrointest Liver Physiol
JT  - American journal of physiology. Gastrointestinal and liver physiology
JID - 100901227
RN  - 0 
      (3-(2-(3-guanidino-2-methyl-3-oxo-propenyl)-5-methylphenyl)-N-isopropylidene-2-methyl-acrylamide 
      dihydrochloride)
RN  - 0 (Dipeptides)
RN  - 0 (Enzyme Activators)
RN  - 0 (Glucose Transporter Type 2)
RN  - 0 (Guanidines)
RN  - 0 (Methacrylates)
RN  - 0 (Peptide Transporter 1)
RN  - 0 (Ribonucleotides)
RN  - 0 (SLC15A1 protein, human)
RN  - 0 (SLC2A2 protein, human)
RN  - 0 (SLC9A3 protein, human)
RN  - 0 (Sodium-Hydrogen Exchanger 3)
RN  - 0 (Sodium-Hydrogen Exchangers)
RN  - 0 (Symporters)
RN  - 360-97-4 (Aminoimidazole Carboxamide)
RN  - EC 2.7.11.31 (AMP-Activated Protein Kinases)
RN  - F0X88YW0YK (AICA ribonucleotide)
SB  - IM
MH  - AMP-Activated Protein Kinases/*metabolism
MH  - Aminoimidazole Carboxamide/analogs & derivatives/pharmacology
MH  - Biological Transport
MH  - Caco-2 Cells
MH  - Cell Polarity
MH  - Cell Shape
MH  - Dipeptides/*metabolism
MH  - Dose-Response Relationship, Drug
MH  - Electric Impedance
MH  - Enzyme Activation
MH  - Enzyme Activators/pharmacology
MH  - Epithelial Cells/drug effects/*enzymology
MH  - Fluorometry
MH  - Glucose Transporter Type 2/metabolism
MH  - Guanidines/pharmacology
MH  - Humans
MH  - Hydrogen-Ion Concentration
MH  - Intestinal Mucosa/drug effects/*enzymology
MH  - Kinetics
MH  - Methacrylates/pharmacology
MH  - Microscopy, Electron, Transmission
MH  - Peptide Transporter 1
MH  - Ribonucleotides/pharmacology
MH  - Sodium-Hydrogen Exchanger 3
MH  - Sodium-Hydrogen Exchangers/antagonists & inhibitors/metabolism
MH  - Symporters/*metabolism
PMC - PMC2904111
EDAT- 2010/05/01 06:00
MHDA- 2010/07/14 06:00
PMCR- 2010/04/29
CRDT- 2010/05/01 06:00
PHST- 2010/05/01 06:00 [entrez]
PHST- 2010/05/01 06:00 [pubmed]
PHST- 2010/07/14 06:00 [medline]
PHST- 2010/04/29 00:00 [pmc-release]
AID - ajpgi.00014.2010 [pii]
AID - GI-00014-2010 [pii]
AID - 10.1152/ajpgi.00014.2010 [doi]
PST - ppublish
SO  - Am J Physiol Gastrointest Liver Physiol. 2010 Jul;299(1):G136-43. doi: 
      10.1152/ajpgi.00014.2010. Epub 2010 Apr 29.