Targeting of 12/15-Lipoxygenase in retinal endothelial cells, but not in monocytes/macrophages, attenuates high glucose-induced retinal leukostasis

Ahmed Salah Ibrahim, Heba Mohamed Saleh, Mohamed El-Shafey, Khaled A. Hussein, Khaled El-Masry, Babak Baban, Nader Sheibani, Mong-Heng Wang, Amany Mohamed Tawfik, Mohamed Al-Shabrawey

Research output: Contribution to journalArticle

4 Citations (Scopus)

Abstract

Aims Our previous studies have established a role for 12/15-lipoxygenase (LO) in mediating the inflammatory response in diabetic retinopathy (DR). However, the extent at which the local or systemic induction of 12/15-LO activity involved is unclear. Thus, the current study aimed to characterize the relative contribution of retinal endothelial versus monocytic/macrophagic 12/15-LO to inflammatory responses in DR. Materials & methods We first generated a clustered heat map for circulating bioactive lipid metabolites in the plasma of streptozotocin (STZ)-induced diabetic mice using liquid chromatography coupled with mass-spectrometry (LC–MS) to evaluate changes in circulating 12/15-LO activity. This was followed by comparing the in vitro mouse endothelium-leukocytes interaction between leukocytes isolated from 12/15-LO knockout (KO) versus those isolated from wild type (WT) mice using the myeloperoxidase (MPO) assay. Finally, we examined the effects of knocking down or inhibiting endothelial 12/15-LO on diabetes-induced endothelial cell activation and ICAM-1 expression. Results Analysis of plasma bioactive lipids' heat map revealed that the activity of circulating 12/15-LO was not altered by diabetes as evident by no significant changes in the plasma levels of major metabolites derived from 12/15-lipoxygenation of different PUFAs, including linoleic acid (13-HODE), arachidonic acid (12- and 15- HETEs), eicosapentaenoic acid (12- and 15- HEPEs), or docosahexaenoic acid (17-HDoHE). Moreover, leukocytes from 12/15-LO KO mice displayed a similar increase in adhesion to high glucose (HG)-activated endothelial cells as do leukocytes from WT mice. Furthermore, abundant proteins of 12-LO and 15-LO were detected in human retinal endothelial cells (HRECs), while it was undetected (15-LO) or hardly detectable (12-LO) in human monocyte-like U937 cells. Inhibition or knock down of endothelial 12/15-LO in HRECs blocked HG-induced expression of ICAM-1, a well-known identified important molecule for leukocyte adhesion in DR. Conclusion Our data support that endothelial, rather than monocytic/macrophagic, 12/15-LO has a critical role in hyperglycemia-induced ICAM-1 expression, leukocyte adhesion, and subsequent local retinal barrier dysfunction. This may facilitate the development of more precisely targeted treatment strategies for DR.

Original languageEnglish (US)
Pages (from-to)636-645
Number of pages10
JournalBiochimica et Biophysica Acta - Molecular and Cell Biology of Lipids
Volume1862
Issue number6
DOIs
StatePublished - Jun 1 2017

Fingerprint

Leukostasis
Monocytes
Endothelial Cells
Macrophages
Glucose
Diabetic Retinopathy
Leukocytes
Intercellular Adhesion Molecule-1
12-15-lipoxygenase
Hot Temperature
12-Hydroxy-5,8,10,14-eicosatetraenoic Acid
Arachidonate 12-Lipoxygenase
Arachidonate 15-Lipoxygenase
Lipids
U937 Cells
Eicosapentaenoic Acid
Docosahexaenoic Acids
Cell Adhesion Molecules
Linoleic Acid
Streptozocin

Keywords

  • 12-HETE
  • 12/15-Lipoxygenase
  • 15-HETE
  • Bioactive lipids
  • Blood retinal barrier
  • Diabetic retinopathy
  • Eicosanoids
  • ICAM-1
  • Leukostasis
  • Permeability

ASJC Scopus subject areas

  • Molecular Biology
  • Cell Biology

Cite this

Targeting of 12/15-Lipoxygenase in retinal endothelial cells, but not in monocytes/macrophages, attenuates high glucose-induced retinal leukostasis. / Ibrahim, Ahmed Salah; Saleh, Heba Mohamed; El-Shafey, Mohamed; Hussein, Khaled A.; El-Masry, Khaled; Baban, Babak; Sheibani, Nader; Wang, Mong-Heng; Tawfik, Amany Mohamed; Al-Shabrawey, Mohamed.

In: Biochimica et Biophysica Acta - Molecular and Cell Biology of Lipids, Vol. 1862, No. 6, 01.06.2017, p. 636-645.

Research output: Contribution to journalArticle

@article{6eab30560da047b1b28e9fb862181676,
title = "Targeting of 12/15-Lipoxygenase in retinal endothelial cells, but not in monocytes/macrophages, attenuates high glucose-induced retinal leukostasis",
abstract = "Aims Our previous studies have established a role for 12/15-lipoxygenase (LO) in mediating the inflammatory response in diabetic retinopathy (DR). However, the extent at which the local or systemic induction of 12/15-LO activity involved is unclear. Thus, the current study aimed to characterize the relative contribution of retinal endothelial versus monocytic/macrophagic 12/15-LO to inflammatory responses in DR. Materials & methods We first generated a clustered heat map for circulating bioactive lipid metabolites in the plasma of streptozotocin (STZ)-induced diabetic mice using liquid chromatography coupled with mass-spectrometry (LC–MS) to evaluate changes in circulating 12/15-LO activity. This was followed by comparing the in vitro mouse endothelium-leukocytes interaction between leukocytes isolated from 12/15-LO knockout (KO) versus those isolated from wild type (WT) mice using the myeloperoxidase (MPO) assay. Finally, we examined the effects of knocking down or inhibiting endothelial 12/15-LO on diabetes-induced endothelial cell activation and ICAM-1 expression. Results Analysis of plasma bioactive lipids' heat map revealed that the activity of circulating 12/15-LO was not altered by diabetes as evident by no significant changes in the plasma levels of major metabolites derived from 12/15-lipoxygenation of different PUFAs, including linoleic acid (13-HODE), arachidonic acid (12- and 15- HETEs), eicosapentaenoic acid (12- and 15- HEPEs), or docosahexaenoic acid (17-HDoHE). Moreover, leukocytes from 12/15-LO KO mice displayed a similar increase in adhesion to high glucose (HG)-activated endothelial cells as do leukocytes from WT mice. Furthermore, abundant proteins of 12-LO and 15-LO were detected in human retinal endothelial cells (HRECs), while it was undetected (15-LO) or hardly detectable (12-LO) in human monocyte-like U937 cells. Inhibition or knock down of endothelial 12/15-LO in HRECs blocked HG-induced expression of ICAM-1, a well-known identified important molecule for leukocyte adhesion in DR. Conclusion Our data support that endothelial, rather than monocytic/macrophagic, 12/15-LO has a critical role in hyperglycemia-induced ICAM-1 expression, leukocyte adhesion, and subsequent local retinal barrier dysfunction. This may facilitate the development of more precisely targeted treatment strategies for DR.",
keywords = "12-HETE, 12/15-Lipoxygenase, 15-HETE, Bioactive lipids, Blood retinal barrier, Diabetic retinopathy, Eicosanoids, ICAM-1, Leukostasis, Permeability",
author = "Ibrahim, {Ahmed Salah} and Saleh, {Heba Mohamed} and Mohamed El-Shafey and Hussein, {Khaled A.} and Khaled El-Masry and Babak Baban and Nader Sheibani and Mong-Heng Wang and Tawfik, {Amany Mohamed} and Mohamed Al-Shabrawey",
year = "2017",
month = "6",
day = "1",
doi = "10.1016/j.bbalip.2017.03.010",
language = "English (US)",
volume = "1862",
pages = "636--645",
journal = "Biochimica et Biophysica Acta - Molecular and Cell Biology of Lipids",
issn = "1388-1981",
publisher = "Elsevier",
number = "6",

}

TY - JOUR

T1 - Targeting of 12/15-Lipoxygenase in retinal endothelial cells, but not in monocytes/macrophages, attenuates high glucose-induced retinal leukostasis

AU - Ibrahim, Ahmed Salah

AU - Saleh, Heba Mohamed

AU - El-Shafey, Mohamed

AU - Hussein, Khaled A.

AU - El-Masry, Khaled

AU - Baban, Babak

AU - Sheibani, Nader

AU - Wang, Mong-Heng

AU - Tawfik, Amany Mohamed

AU - Al-Shabrawey, Mohamed

PY - 2017/6/1

Y1 - 2017/6/1

N2 - Aims Our previous studies have established a role for 12/15-lipoxygenase (LO) in mediating the inflammatory response in diabetic retinopathy (DR). However, the extent at which the local or systemic induction of 12/15-LO activity involved is unclear. Thus, the current study aimed to characterize the relative contribution of retinal endothelial versus monocytic/macrophagic 12/15-LO to inflammatory responses in DR. Materials & methods We first generated a clustered heat map for circulating bioactive lipid metabolites in the plasma of streptozotocin (STZ)-induced diabetic mice using liquid chromatography coupled with mass-spectrometry (LC–MS) to evaluate changes in circulating 12/15-LO activity. This was followed by comparing the in vitro mouse endothelium-leukocytes interaction between leukocytes isolated from 12/15-LO knockout (KO) versus those isolated from wild type (WT) mice using the myeloperoxidase (MPO) assay. Finally, we examined the effects of knocking down or inhibiting endothelial 12/15-LO on diabetes-induced endothelial cell activation and ICAM-1 expression. Results Analysis of plasma bioactive lipids' heat map revealed that the activity of circulating 12/15-LO was not altered by diabetes as evident by no significant changes in the plasma levels of major metabolites derived from 12/15-lipoxygenation of different PUFAs, including linoleic acid (13-HODE), arachidonic acid (12- and 15- HETEs), eicosapentaenoic acid (12- and 15- HEPEs), or docosahexaenoic acid (17-HDoHE). Moreover, leukocytes from 12/15-LO KO mice displayed a similar increase in adhesion to high glucose (HG)-activated endothelial cells as do leukocytes from WT mice. Furthermore, abundant proteins of 12-LO and 15-LO were detected in human retinal endothelial cells (HRECs), while it was undetected (15-LO) or hardly detectable (12-LO) in human monocyte-like U937 cells. Inhibition or knock down of endothelial 12/15-LO in HRECs blocked HG-induced expression of ICAM-1, a well-known identified important molecule for leukocyte adhesion in DR. Conclusion Our data support that endothelial, rather than monocytic/macrophagic, 12/15-LO has a critical role in hyperglycemia-induced ICAM-1 expression, leukocyte adhesion, and subsequent local retinal barrier dysfunction. This may facilitate the development of more precisely targeted treatment strategies for DR.

AB - Aims Our previous studies have established a role for 12/15-lipoxygenase (LO) in mediating the inflammatory response in diabetic retinopathy (DR). However, the extent at which the local or systemic induction of 12/15-LO activity involved is unclear. Thus, the current study aimed to characterize the relative contribution of retinal endothelial versus monocytic/macrophagic 12/15-LO to inflammatory responses in DR. Materials & methods We first generated a clustered heat map for circulating bioactive lipid metabolites in the plasma of streptozotocin (STZ)-induced diabetic mice using liquid chromatography coupled with mass-spectrometry (LC–MS) to evaluate changes in circulating 12/15-LO activity. This was followed by comparing the in vitro mouse endothelium-leukocytes interaction between leukocytes isolated from 12/15-LO knockout (KO) versus those isolated from wild type (WT) mice using the myeloperoxidase (MPO) assay. Finally, we examined the effects of knocking down or inhibiting endothelial 12/15-LO on diabetes-induced endothelial cell activation and ICAM-1 expression. Results Analysis of plasma bioactive lipids' heat map revealed that the activity of circulating 12/15-LO was not altered by diabetes as evident by no significant changes in the plasma levels of major metabolites derived from 12/15-lipoxygenation of different PUFAs, including linoleic acid (13-HODE), arachidonic acid (12- and 15- HETEs), eicosapentaenoic acid (12- and 15- HEPEs), or docosahexaenoic acid (17-HDoHE). Moreover, leukocytes from 12/15-LO KO mice displayed a similar increase in adhesion to high glucose (HG)-activated endothelial cells as do leukocytes from WT mice. Furthermore, abundant proteins of 12-LO and 15-LO were detected in human retinal endothelial cells (HRECs), while it was undetected (15-LO) or hardly detectable (12-LO) in human monocyte-like U937 cells. Inhibition or knock down of endothelial 12/15-LO in HRECs blocked HG-induced expression of ICAM-1, a well-known identified important molecule for leukocyte adhesion in DR. Conclusion Our data support that endothelial, rather than monocytic/macrophagic, 12/15-LO has a critical role in hyperglycemia-induced ICAM-1 expression, leukocyte adhesion, and subsequent local retinal barrier dysfunction. This may facilitate the development of more precisely targeted treatment strategies for DR.

KW - 12-HETE

KW - 12/15-Lipoxygenase

KW - 15-HETE

KW - Bioactive lipids

KW - Blood retinal barrier

KW - Diabetic retinopathy

KW - Eicosanoids

KW - ICAM-1

KW - Leukostasis

KW - Permeability

UR - http://www.scopus.com/inward/record.url?scp=85017318954&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85017318954&partnerID=8YFLogxK

U2 - 10.1016/j.bbalip.2017.03.010

DO - 10.1016/j.bbalip.2017.03.010

M3 - Article

VL - 1862

SP - 636

EP - 645

JO - Biochimica et Biophysica Acta - Molecular and Cell Biology of Lipids

JF - Biochimica et Biophysica Acta - Molecular and Cell Biology of Lipids

SN - 1388-1981

IS - 6

ER -