Targeting pancreatic islets with phage display assisted by laser pressure catapult microdissection
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Targeting pancreatic islets with phage display assisted by laser pressure catapult microdissection. / Yao, Virginia J; Ozawa, Michael G; Trepel, Martin; Arap, Wadih; McDonald, Donald M; Pasqualini, Renata.
In: AM J PATHOL, Vol. 166, No. 2, 02.2005, p. 625-36.Research output: SCORING: Contribution to journal › SCORING: Journal article › Research › peer-review
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TY - JOUR
T1 - Targeting pancreatic islets with phage display assisted by laser pressure catapult microdissection
AU - Yao, Virginia J
AU - Ozawa, Michael G
AU - Trepel, Martin
AU - Arap, Wadih
AU - McDonald, Donald M
AU - Pasqualini, Renata
PY - 2005/2
Y1 - 2005/2
N2 - Heterogeneity of the microvasculature in different organs has been well documented by multiple methods including in vivo phage display. However, less is known about the diversity of blood vessels within functionally distinct regions of organs. Here, we combined in vivo phage display with laser pressure catapult microdissection to identify peptide ligands for vascular receptors in the islets of Langerhans in the murine pancreas. Protein database analyses of the peptides, CVSNPRWKC and CHVLWSTRC, showed sequence identity to two ephrin A-type ligand homologues, A2 and A4. Confocal microscopy confirmed that most immunoreactivity of CVSNPRWKC and CHVLWSTRC phage was associated with blood vessels in pancreatic islets. Antibodies recognizing EphA4, a receptor for ephrin-A ligands, were similarly associated with islet blood vessels. Importantly, binding of both islet-homing phage and anti-EphA4 antibody was strikingly increased in blood vessels of pancreatic islet tumors in RIP-Tag2 transgenic mice. These results indicate that endothelial cells of blood vessels in pancreatic islets preferentially express EphA4 receptors, and this expression is increased in tumors. Our findings show in vivo phage display and laser pressure catapult microdissection can be combined to reveal endothelial cell specialization within focal regions of the microvasculature.
AB - Heterogeneity of the microvasculature in different organs has been well documented by multiple methods including in vivo phage display. However, less is known about the diversity of blood vessels within functionally distinct regions of organs. Here, we combined in vivo phage display with laser pressure catapult microdissection to identify peptide ligands for vascular receptors in the islets of Langerhans in the murine pancreas. Protein database analyses of the peptides, CVSNPRWKC and CHVLWSTRC, showed sequence identity to two ephrin A-type ligand homologues, A2 and A4. Confocal microscopy confirmed that most immunoreactivity of CVSNPRWKC and CHVLWSTRC phage was associated with blood vessels in pancreatic islets. Antibodies recognizing EphA4, a receptor for ephrin-A ligands, were similarly associated with islet blood vessels. Importantly, binding of both islet-homing phage and anti-EphA4 antibody was strikingly increased in blood vessels of pancreatic islet tumors in RIP-Tag2 transgenic mice. These results indicate that endothelial cells of blood vessels in pancreatic islets preferentially express EphA4 receptors, and this expression is increased in tumors. Our findings show in vivo phage display and laser pressure catapult microdissection can be combined to reveal endothelial cell specialization within focal regions of the microvasculature.
KW - Amino Acid Sequence
KW - Animals
KW - Antigens, CD31
KW - Clinical Trials as Topic
KW - Databases as Topic
KW - Dissection
KW - Ephrin-A1
KW - Humans
KW - Immunohistochemistry
KW - Islets of Langerhans
KW - Lasers
KW - Ligands
KW - Male
KW - Mice
KW - Mice, Inbred C57BL
KW - Mice, Transgenic
KW - Microcirculation
KW - Microscopy, Confocal
KW - Microscopy, Fluorescence
KW - Molecular Sequence Data
KW - Peptide Library
KW - Peptides
KW - Protein Structure, Secondary
KW - Software
KW - Journal Article
KW - Research Support, Non-U.S. Gov't
KW - Research Support, U.S. Gov't, P.H.S.
U2 - 10.1016/S0002-9440(10)62283-3
DO - 10.1016/S0002-9440(10)62283-3
M3 - SCORING: Journal article
C2 - 15681844
VL - 166
SP - 625
EP - 636
JO - AM J PATHOL
JF - AM J PATHOL
SN - 0002-9440
IS - 2
ER -