Protection of blood retinal barrier and systemic vasculature by insulin-like growth factor binding protein-3

Yagna P R Jarajapu, Jun Cai, Yuanqing Yan, Sergio Calzi, Jennifer L. Kielczewski, Ping Hu, Lynn C. Shaw, Sue M. Firth, Tailoi Chan-Ling, Michael E. Boulton, Robert C. Baxter, Maria B. Grant

Research output: Contribution to journalArticle

16 Citations (Scopus)

Abstract

Previously, we showed that insulin growth factor (IGF)-1 binding protein-3 (IGFBP-3), independent of IGF-1, reduces pathological angiogenesis in a mouse model of the oxygen-induced retinopathy (OIR). The current study evaluates novel endothelium-dependent functions of IGFBP-3 including blood retinal barrier (BRB) integrity and vasorelaxation. To evaluate vascular barrier function, either plasmid expressing IGFBP-3 under the regulation of an endothelial-specific promoter or a control plasmid was injected into the vitreous humor of mouse pups (P1) and compared to the non-injected eyes of the same pups undergoing standard OIR protocol. Prior to sacrifice, the mice were given an injection of horseradish peroxidase (HRP). IGFBP-3 plasmid-injected eyes displayed near-normal vessel morphology and enhanced vascular barrier function. Further, in vitro IGFBP-3 protects retinal endothelial cells from VEGF-induced loss of junctional integrity by antagonizing the dissociation of the junctional complexes. To assess the vasodilatory effects of IGFBP-3, rat posterior cerebral arteries were examined in vitro. Intraluminal IGFBP-3 decreased both pressure- and serotonin-induced constrictions by stimulating nitric oxide (NO) release that were blocked by L-NAME or scavenger receptor-B1 neutralizing antibody (SRB1-Ab). Both wild-type and IGF-1-nonbinding mutant IGFBP-3 (IGFBP-3NB) stimulated eNOS activity/NO release to a similar extent in human microvascular endothelial cells (HMVECs). NO release was neither associated with an increase in intracellular calcium nor decreased by Ca2+/calmodulin-dependent protein kinase II (CamKII) blockade; however, dephosphorylation of eNOS-Thr495 was observed. Phosphatidylinositol 3-kinase (PI3K) activity and Akt-Ser473 phosphorylation were both increased by IGFBP-3 and selectively blocked by the SRB1-Ab or PI3K blocker LY294002. In conclusion, IGFBP-3 mediates protective effects on BRB integrity and mediates robust NO release to stimulate vasorelaxation via activation of SRB1. This response is IGF-1- and calcium-independent, but requires PI3K/Akt activation, suggesting that IGFBP-3 has novel protective effects on retinal and systemic vasculature and may be a therapeutic candidate for ocular complications such as diabetic retinopathy.

Original languageEnglish (US)
Article numbere39398
JournalPLoS One
Volume7
Issue number7
DOIs
StatePublished - Jul 6 2012
Externally publishedYes

Fingerprint

Blood-Retinal Barrier
Insulin-Like Growth Factor Binding Protein 1
Insulin-Like Growth Factor Binding Protein 3
insulin-like growth factor binding proteins
Insulin-Like Growth Factor I
binding proteins
Blood
blood
Phosphatidylinositol 3-Kinase
growth factors
Intercellular Signaling Peptides and Proteins
Nitric Oxide
nitric oxide
phosphatidylinositol 3-kinase
insulin
Insulin
Scavenger Receptors
Plasmids
retinal diseases
plasmids

ASJC Scopus subject areas

  • Agricultural and Biological Sciences(all)
  • Biochemistry, Genetics and Molecular Biology(all)
  • Medicine(all)

Cite this

Jarajapu, Y. P. R., Cai, J., Yan, Y., Calzi, S., Kielczewski, J. L., Hu, P., ... Grant, M. B. (2012). Protection of blood retinal barrier and systemic vasculature by insulin-like growth factor binding protein-3. PLoS One, 7(7), [e39398]. https://doi.org/10.1371/journal.pone.0039398

Protection of blood retinal barrier and systemic vasculature by insulin-like growth factor binding protein-3. / Jarajapu, Yagna P R; Cai, Jun; Yan, Yuanqing; Calzi, Sergio; Kielczewski, Jennifer L.; Hu, Ping; Shaw, Lynn C.; Firth, Sue M.; Chan-Ling, Tailoi; Boulton, Michael E.; Baxter, Robert C.; Grant, Maria B.

In: PLoS One, Vol. 7, No. 7, e39398, 06.07.2012.

Research output: Contribution to journalArticle

Jarajapu, YPR, Cai, J, Yan, Y, Calzi, S, Kielczewski, JL, Hu, P, Shaw, LC, Firth, SM, Chan-Ling, T, Boulton, ME, Baxter, RC & Grant, MB 2012, 'Protection of blood retinal barrier and systemic vasculature by insulin-like growth factor binding protein-3', PLoS One, vol. 7, no. 7, e39398. https://doi.org/10.1371/journal.pone.0039398
Jarajapu, Yagna P R ; Cai, Jun ; Yan, Yuanqing ; Calzi, Sergio ; Kielczewski, Jennifer L. ; Hu, Ping ; Shaw, Lynn C. ; Firth, Sue M. ; Chan-Ling, Tailoi ; Boulton, Michael E. ; Baxter, Robert C. ; Grant, Maria B. / Protection of blood retinal barrier and systemic vasculature by insulin-like growth factor binding protein-3. In: PLoS One. 2012 ; Vol. 7, No. 7.
@article{53b558c02eac4303b56c9346266de08d,
title = "Protection of blood retinal barrier and systemic vasculature by insulin-like growth factor binding protein-3",
abstract = "Previously, we showed that insulin growth factor (IGF)-1 binding protein-3 (IGFBP-3), independent of IGF-1, reduces pathological angiogenesis in a mouse model of the oxygen-induced retinopathy (OIR). The current study evaluates novel endothelium-dependent functions of IGFBP-3 including blood retinal barrier (BRB) integrity and vasorelaxation. To evaluate vascular barrier function, either plasmid expressing IGFBP-3 under the regulation of an endothelial-specific promoter or a control plasmid was injected into the vitreous humor of mouse pups (P1) and compared to the non-injected eyes of the same pups undergoing standard OIR protocol. Prior to sacrifice, the mice were given an injection of horseradish peroxidase (HRP). IGFBP-3 plasmid-injected eyes displayed near-normal vessel morphology and enhanced vascular barrier function. Further, in vitro IGFBP-3 protects retinal endothelial cells from VEGF-induced loss of junctional integrity by antagonizing the dissociation of the junctional complexes. To assess the vasodilatory effects of IGFBP-3, rat posterior cerebral arteries were examined in vitro. Intraluminal IGFBP-3 decreased both pressure- and serotonin-induced constrictions by stimulating nitric oxide (NO) release that were blocked by L-NAME or scavenger receptor-B1 neutralizing antibody (SRB1-Ab). Both wild-type and IGF-1-nonbinding mutant IGFBP-3 (IGFBP-3NB) stimulated eNOS activity/NO release to a similar extent in human microvascular endothelial cells (HMVECs). NO release was neither associated with an increase in intracellular calcium nor decreased by Ca2+/calmodulin-dependent protein kinase II (CamKII) blockade; however, dephosphorylation of eNOS-Thr495 was observed. Phosphatidylinositol 3-kinase (PI3K) activity and Akt-Ser473 phosphorylation were both increased by IGFBP-3 and selectively blocked by the SRB1-Ab or PI3K blocker LY294002. In conclusion, IGFBP-3 mediates protective effects on BRB integrity and mediates robust NO release to stimulate vasorelaxation via activation of SRB1. This response is IGF-1- and calcium-independent, but requires PI3K/Akt activation, suggesting that IGFBP-3 has novel protective effects on retinal and systemic vasculature and may be a therapeutic candidate for ocular complications such as diabetic retinopathy.",
author = "Jarajapu, {Yagna P R} and Jun Cai and Yuanqing Yan and Sergio Calzi and Kielczewski, {Jennifer L.} and Ping Hu and Shaw, {Lynn C.} and Firth, {Sue M.} and Tailoi Chan-Ling and Boulton, {Michael E.} and Baxter, {Robert C.} and Grant, {Maria B.}",
year = "2012",
month = "7",
day = "6",
doi = "10.1371/journal.pone.0039398",
language = "English (US)",
volume = "7",
journal = "PLoS One",
issn = "1932-6203",
publisher = "Public Library of Science",
number = "7",

}

TY - JOUR

T1 - Protection of blood retinal barrier and systemic vasculature by insulin-like growth factor binding protein-3

AU - Jarajapu, Yagna P R

AU - Cai, Jun

AU - Yan, Yuanqing

AU - Calzi, Sergio

AU - Kielczewski, Jennifer L.

AU - Hu, Ping

AU - Shaw, Lynn C.

AU - Firth, Sue M.

AU - Chan-Ling, Tailoi

AU - Boulton, Michael E.

AU - Baxter, Robert C.

AU - Grant, Maria B.

PY - 2012/7/6

Y1 - 2012/7/6

N2 - Previously, we showed that insulin growth factor (IGF)-1 binding protein-3 (IGFBP-3), independent of IGF-1, reduces pathological angiogenesis in a mouse model of the oxygen-induced retinopathy (OIR). The current study evaluates novel endothelium-dependent functions of IGFBP-3 including blood retinal barrier (BRB) integrity and vasorelaxation. To evaluate vascular barrier function, either plasmid expressing IGFBP-3 under the regulation of an endothelial-specific promoter or a control plasmid was injected into the vitreous humor of mouse pups (P1) and compared to the non-injected eyes of the same pups undergoing standard OIR protocol. Prior to sacrifice, the mice were given an injection of horseradish peroxidase (HRP). IGFBP-3 plasmid-injected eyes displayed near-normal vessel morphology and enhanced vascular barrier function. Further, in vitro IGFBP-3 protects retinal endothelial cells from VEGF-induced loss of junctional integrity by antagonizing the dissociation of the junctional complexes. To assess the vasodilatory effects of IGFBP-3, rat posterior cerebral arteries were examined in vitro. Intraluminal IGFBP-3 decreased both pressure- and serotonin-induced constrictions by stimulating nitric oxide (NO) release that were blocked by L-NAME or scavenger receptor-B1 neutralizing antibody (SRB1-Ab). Both wild-type and IGF-1-nonbinding mutant IGFBP-3 (IGFBP-3NB) stimulated eNOS activity/NO release to a similar extent in human microvascular endothelial cells (HMVECs). NO release was neither associated with an increase in intracellular calcium nor decreased by Ca2+/calmodulin-dependent protein kinase II (CamKII) blockade; however, dephosphorylation of eNOS-Thr495 was observed. Phosphatidylinositol 3-kinase (PI3K) activity and Akt-Ser473 phosphorylation were both increased by IGFBP-3 and selectively blocked by the SRB1-Ab or PI3K blocker LY294002. In conclusion, IGFBP-3 mediates protective effects on BRB integrity and mediates robust NO release to stimulate vasorelaxation via activation of SRB1. This response is IGF-1- and calcium-independent, but requires PI3K/Akt activation, suggesting that IGFBP-3 has novel protective effects on retinal and systemic vasculature and may be a therapeutic candidate for ocular complications such as diabetic retinopathy.

AB - Previously, we showed that insulin growth factor (IGF)-1 binding protein-3 (IGFBP-3), independent of IGF-1, reduces pathological angiogenesis in a mouse model of the oxygen-induced retinopathy (OIR). The current study evaluates novel endothelium-dependent functions of IGFBP-3 including blood retinal barrier (BRB) integrity and vasorelaxation. To evaluate vascular barrier function, either plasmid expressing IGFBP-3 under the regulation of an endothelial-specific promoter or a control plasmid was injected into the vitreous humor of mouse pups (P1) and compared to the non-injected eyes of the same pups undergoing standard OIR protocol. Prior to sacrifice, the mice were given an injection of horseradish peroxidase (HRP). IGFBP-3 plasmid-injected eyes displayed near-normal vessel morphology and enhanced vascular barrier function. Further, in vitro IGFBP-3 protects retinal endothelial cells from VEGF-induced loss of junctional integrity by antagonizing the dissociation of the junctional complexes. To assess the vasodilatory effects of IGFBP-3, rat posterior cerebral arteries were examined in vitro. Intraluminal IGFBP-3 decreased both pressure- and serotonin-induced constrictions by stimulating nitric oxide (NO) release that were blocked by L-NAME or scavenger receptor-B1 neutralizing antibody (SRB1-Ab). Both wild-type and IGF-1-nonbinding mutant IGFBP-3 (IGFBP-3NB) stimulated eNOS activity/NO release to a similar extent in human microvascular endothelial cells (HMVECs). NO release was neither associated with an increase in intracellular calcium nor decreased by Ca2+/calmodulin-dependent protein kinase II (CamKII) blockade; however, dephosphorylation of eNOS-Thr495 was observed. Phosphatidylinositol 3-kinase (PI3K) activity and Akt-Ser473 phosphorylation were both increased by IGFBP-3 and selectively blocked by the SRB1-Ab or PI3K blocker LY294002. In conclusion, IGFBP-3 mediates protective effects on BRB integrity and mediates robust NO release to stimulate vasorelaxation via activation of SRB1. This response is IGF-1- and calcium-independent, but requires PI3K/Akt activation, suggesting that IGFBP-3 has novel protective effects on retinal and systemic vasculature and may be a therapeutic candidate for ocular complications such as diabetic retinopathy.

UR - http://www.scopus.com/inward/record.url?scp=84863713673&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84863713673&partnerID=8YFLogxK

U2 - 10.1371/journal.pone.0039398

DO - 10.1371/journal.pone.0039398

M3 - Article

C2 - 22792172

AN - SCOPUS:84863713673

VL - 7

JO - PLoS One

JF - PLoS One

SN - 1932-6203

IS - 7

M1 - e39398

ER -