TY - JOUR
T1 - Mechanism of action of ZOT-derived peptide AT-1002, a tight junction regulator and absorption enhancer
AU - Gopalakrishnan, Shobha
AU - Pandey, Niranjan
AU - Tamiz, Amir P.
AU - Vere, John
AU - Carrasco, Rosa
AU - Somerville, Robert
AU - Tripathi, Amit
AU - Ginski, Mark
AU - Paterson, Blake M.
AU - Alkan, Sefik S.
PY - 2009/1/5
Y1 - 2009/1/5
N2 - Tight junctions (TJs) are intercellular structures that control paracellular permeability and epithelial polarity. It is now accepted that TJs are highly dynamic structures that are regulated in response to exogenous and endogenous stimuli. Here, we provide details on the mechanism of action of AT-1002, the active domain of Vibrio cholerae's second toxin, zonula occludens toxin (ZOT). AT-1002, a hexamer peptide, caused the redistribution of ZO-1 away from cell junctions as seen by fluorescence microscopy. AT-1002 also activated src and mitogen activated protein (MAP) kinase pathways, increased ZO-1 tyrosine phosphorylation, and rearrangement of actin filaments. Functionally, AT-1002 caused a reversible reduction in transepithelial electrical resistance (TEER) and an increase in lucifer yellow permeability in Caco-2 cell monolayers. In vivo, co-administration of salmon calcitonin with 1 mg of AT-1002 resulted in a 5.2-fold increase in AUC over the control group. Our findings provide a mechanistic explanation for AT-1002-induced tight junction disassembly, and demonstrate that AT-1002 can be used for delivery of other agents in vivo.
AB - Tight junctions (TJs) are intercellular structures that control paracellular permeability and epithelial polarity. It is now accepted that TJs are highly dynamic structures that are regulated in response to exogenous and endogenous stimuli. Here, we provide details on the mechanism of action of AT-1002, the active domain of Vibrio cholerae's second toxin, zonula occludens toxin (ZOT). AT-1002, a hexamer peptide, caused the redistribution of ZO-1 away from cell junctions as seen by fluorescence microscopy. AT-1002 also activated src and mitogen activated protein (MAP) kinase pathways, increased ZO-1 tyrosine phosphorylation, and rearrangement of actin filaments. Functionally, AT-1002 caused a reversible reduction in transepithelial electrical resistance (TEER) and an increase in lucifer yellow permeability in Caco-2 cell monolayers. In vivo, co-administration of salmon calcitonin with 1 mg of AT-1002 resulted in a 5.2-fold increase in AUC over the control group. Our findings provide a mechanistic explanation for AT-1002-induced tight junction disassembly, and demonstrate that AT-1002 can be used for delivery of other agents in vivo.
KW - AT-1002
KW - Mechanism of action
KW - Permeability
KW - Tight junctions
UR - http://www.scopus.com/inward/record.url?scp=57049114897&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=57049114897&partnerID=8YFLogxK
U2 - 10.1016/j.ijpharm.2008.08.047
DO - 10.1016/j.ijpharm.2008.08.047
M3 - Article
C2 - 18832018
AN - SCOPUS:57049114897
SN - 0378-5173
VL - 365
SP - 121
EP - 130
JO - International Journal of Pharmaceutics
JF - International Journal of Pharmaceutics
IS - 1-2
ER -