PMID- 15521010
OWN - NLM
STAT- MEDLINE
DCOM- 20041203
LR  - 20190707
IS  - 0016-5085 (Print)
IS  - 0016-5085 (Linking)
VI  - 127
IP  - 5
DP  - 2004 Nov
TI  - hPepT1 transports muramyl dipeptide, activating NF-kappaB and stimulating IL-8 
      secretion in human colonic Caco2/bbe cells.
PG  - 1401-9
AB  - BACKGROUND AND AIMS: Bacterial proteoglycan-derived muramyl dipeptide (MDP) 
      activates the intracellular NOD2/CARD15 gene product. How intestinal epithelial 
      cells take up MDP is poorly understood. We hypothesized that the intestinal 
      apical di-/tripeptide transporter, hPepT1, transports MDP, thereby activating 
      downstream pathways similar to nuclear factor kappa B (NF-kappaB). METHODS: Time- 
      and concentration-dependent (3)H-MDP uptakes were studied in Caco2/bbe (C2) cell 
      monolayers where hPepT1 expression was either over- or underexpressed, using an 
      inducible adenovirus system or silencing RNA (siRNA), respectively. NF-kappaB 
      activation and interleukin (IL)-8 and monocyte chemoattractant protein-1 (MCP-1) 
      release were determined by enzyme-linked immunosorbent assay. NOD2/CARD15 
      expression was inhibited by siRNA. MDP in human duodenal, cecal, and stool 
      samples was measured. RESULTS: MDP, but not its isoforms, inhibited uptake of 
      glycosylsarcosine in C2 cells, indicating stereoselective and competitive 
      inhibition. Approximately 90% of the MDP was cytosolic, showing uptake rather 
      than binding. The K m for MDP uptake was 4.3 mmol/L. Cells overexpressing hPepT1 
      showed increased Gly-Sar and MDP uptake, whereas decreased uptake was observed 
      after hPepT1 siRNA-inhibition. MDP treatment activated NF-kappaB, resulting in 
      IL-8 release, an effect blocked by siRNA-inhibited expression of NOD2/CARD15. MDP 
      content in cecal and stool samples (in normal subjects) was 20-87 micromol/L, but 
      undetectable in duodenal fluid. CONCLUSIONS: In colonic epithelial cells, MDP is 
      taken up by hPepT1 and activates NF-kappaB and chemokine production. Because 
      hPepT1 expression in chronic colonic inflammation is increased, this may play an 
      important role in promoting colonocyte participation in host defense and pathogen 
      clearance through increased uptake of MDP.
FAU - Vavricka, Stephan R
AU  - Vavricka SR
AD  - IBD Research Center, University of Chicago, Chicago, IL 60637, USA.
FAU - Musch, Mark W
AU  - Musch MW
FAU - Chang, Jonathan E
AU  - Chang JE
FAU - Nakagawa, Yasushi
AU  - Nakagawa Y
FAU - Phanvijhitsiri, Kittiporn
AU  - Phanvijhitsiri K
FAU - Waypa, Tonya S
AU  - Waypa TS
FAU - Merlin, Didier
AU  - Merlin D
FAU - Schneewind, Olaf
AU  - Schneewind O
FAU - Chang, Eugene B
AU  - Chang EB
LA  - eng
GR  - DK-061941/DK/NIDDK NIH HHS/United States
GR  - DK-38510/DK/NIDDK NIH HHS/United States
GR  - DK-42086/DK/NIDDK NIH HHS/United States
GR  - DK-47722/DK/NIDDK NIH HHS/United States
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PT  - Research Support, U.S. Gov't, P.H.S.
PL  - United States
TA  - Gastroenterology
JT  - Gastroenterology
JID - 0374630
RN  - 0 (CCL2 protein, human)
RN  - 0 (Chemokine CCL2)
RN  - 0 (Interleukin-8)
RN  - 0 (NF-kappa B)
RN  - 0 (Peptide Fragments)
RN  - 0 (Peptide Transporter 1)
RN  - 0 (RNA, Small Interfering)
RN  - 0 (SLC15A1 protein, human)
RN  - 0 (Symporters)
RN  - 53678-77-6 (Acetylmuramyl-Alanyl-Isoglutamine)
SB  - IM
MH  - Acetylmuramyl-Alanyl-Isoglutamine/*metabolism
MH  - Amino Acid Sequence
MH  - Biological Transport
MH  - Cell Line, Tumor
MH  - Chemokine CCL2/metabolism
MH  - Colonic Neoplasms
MH  - Gene Expression Regulation, Neoplastic
MH  - Humans
MH  - Interleukin-8/*metabolism
MH  - Intestinal Mucosa
MH  - Molecular Sequence Data
MH  - NF-kappa B/*metabolism
MH  - Peptide Fragments/chemistry
MH  - Peptide Transporter 1
MH  - RNA, Small Interfering/genetics
MH  - Symporters/*genetics/metabolism
EDAT- 2004/11/03 09:00
MHDA- 2004/12/16 09:00
CRDT- 2004/11/03 09:00
PHST- 2004/11/03 09:00 [pubmed]
PHST- 2004/12/16 09:00 [medline]
PHST- 2004/11/03 09:00 [entrez]
AID - S0016508504013320 [pii]
AID - 10.1053/j.gastro.2004.07.024 [doi]
PST - ppublish
SO  - Gastroenterology. 2004 Nov;127(5):1401-9. doi: 10.1053/j.gastro.2004.07.024.