Inhibition of cytokine signaling in human retinal endothelial cells through modification of caveolae/lipid rafts by docosahexaenoic acid

Weiqin Chen, Donald B. Jump, Walter J. Esselman, Julia V. Busik

Research output: Contribution to journalArticle

64 Citations (Scopus)

Abstract

PURPOSE. Docosahexaenoic acid (DHA22:6,n3) is the principal n3 polyunsaturated fatty acid (PUFA) in the retina. The authors previously demonstrated that DHA22:6,n3 inhibited cytokine-induced adhesion molecule expression in primary human retinal vascular endothelial (hRVE) cells, the target tissue affected by diabetic retinopathy. Despite the importance of vascular inflammation in diabetic retinopathy, the mechanisms underlying anti-inflammatory effects of DHA22:6,n3 in vascular endothelial cells are not understood. In this study the authors address the hypothesis that DHA22:6,n3 acts through modifying lipid composition of caveolae/lipid rafts, thereby changing the outcome of important signaling events in these specialized plasma membrane microdomains. METHODS. hRVE cells were cultured in the presence or absence of DHA22:6,n3. Isolated caveolae/lipid raft- enriched detergent-resistant membrane domains were prepared using sucrose gradient ultracentrifugation. Fatty acid composition and cholesterol content of caveolae/lipid rafts before and after treatment were measured by HPLC. The expression of Src family kinases was assayed by Western blotting and immunohistochernistry. RESULTS. Disruption of the caveolae/lipid raft structure with a cholesterol-depleting agent, methyl-cyclodextrin (MCD), diminished cytokine-induced signaling in hRVE cells. Growth of hRVE cells in media enriched in DHA22:6,n3 resulted in significant incorporation of DHA 22:6,n3 into the major phospholipids of caveolae/lipid rafts, causing an increase in the unsaturation index in the membrane microdomain. DHA 22:6,n3 enrichment in the caveolae/raft was accompanied by a 70% depletion of cholesterol from caveolae/lipid rafts and displacement of the SFK, Fyn, and c-Yes from caveolae/lipid rafts. Adding water-soluble cholesterol to DHA22:6,n3-treated cells replenished cholesterol in caveolae/lipid rafts and reversed the effect of DHA22:6,n3 on cytokine-induced signaling. CONCLUSIONS. Incorporation of DHA22:6,n3 into fatty acyl chains of phospholipids in caveolae/lipid rafts, followed by cholesterol depletion and displacement of important signaling molecules, provides a potential mechanism for anti-inflammatory effect of DHA22:6,n3 in hRVE cells.

Original languageEnglish (US)
Pages (from-to)18-26
Number of pages9
JournalInvestigative Ophthalmology and Visual Science
Volume48
Issue number1
DOIs
StatePublished - Jan 1 2007
Externally publishedYes

Fingerprint

Caveolae
Docosahexaenoic Acids
Endothelial Cells
Cytokines
Lipids
Retinal Vessels
Cholesterol
Membrane Microdomains
Diabetic Retinopathy
Phospholipids
Anti-Inflammatory Agents
src-Family Kinases
Ultracentrifugation
Omega-3 Fatty Acids
Cyclodextrins
Detergents
Blood Vessels
Sucrose
Retina
Fatty Acids

ASJC Scopus subject areas

  • Ophthalmology
  • Sensory Systems
  • Cellular and Molecular Neuroscience

Cite this

Inhibition of cytokine signaling in human retinal endothelial cells through modification of caveolae/lipid rafts by docosahexaenoic acid. / Chen, Weiqin; Jump, Donald B.; Esselman, Walter J.; Busik, Julia V.

In: Investigative Ophthalmology and Visual Science, Vol. 48, No. 1, 01.01.2007, p. 18-26.

Research output: Contribution to journalArticle

@article{56f46ed102414137a0157f98d0b8f43d,
title = "Inhibition of cytokine signaling in human retinal endothelial cells through modification of caveolae/lipid rafts by docosahexaenoic acid",
abstract = "PURPOSE. Docosahexaenoic acid (DHA22:6,n3) is the principal n3 polyunsaturated fatty acid (PUFA) in the retina. The authors previously demonstrated that DHA22:6,n3 inhibited cytokine-induced adhesion molecule expression in primary human retinal vascular endothelial (hRVE) cells, the target tissue affected by diabetic retinopathy. Despite the importance of vascular inflammation in diabetic retinopathy, the mechanisms underlying anti-inflammatory effects of DHA22:6,n3 in vascular endothelial cells are not understood. In this study the authors address the hypothesis that DHA22:6,n3 acts through modifying lipid composition of caveolae/lipid rafts, thereby changing the outcome of important signaling events in these specialized plasma membrane microdomains. METHODS. hRVE cells were cultured in the presence or absence of DHA22:6,n3. Isolated caveolae/lipid raft- enriched detergent-resistant membrane domains were prepared using sucrose gradient ultracentrifugation. Fatty acid composition and cholesterol content of caveolae/lipid rafts before and after treatment were measured by HPLC. The expression of Src family kinases was assayed by Western blotting and immunohistochernistry. RESULTS. Disruption of the caveolae/lipid raft structure with a cholesterol-depleting agent, methyl-cyclodextrin (MCD), diminished cytokine-induced signaling in hRVE cells. Growth of hRVE cells in media enriched in DHA22:6,n3 resulted in significant incorporation of DHA 22:6,n3 into the major phospholipids of caveolae/lipid rafts, causing an increase in the unsaturation index in the membrane microdomain. DHA 22:6,n3 enrichment in the caveolae/raft was accompanied by a 70{\%} depletion of cholesterol from caveolae/lipid rafts and displacement of the SFK, Fyn, and c-Yes from caveolae/lipid rafts. Adding water-soluble cholesterol to DHA22:6,n3-treated cells replenished cholesterol in caveolae/lipid rafts and reversed the effect of DHA22:6,n3 on cytokine-induced signaling. CONCLUSIONS. Incorporation of DHA22:6,n3 into fatty acyl chains of phospholipids in caveolae/lipid rafts, followed by cholesterol depletion and displacement of important signaling molecules, provides a potential mechanism for anti-inflammatory effect of DHA22:6,n3 in hRVE cells.",
author = "Weiqin Chen and Jump, {Donald B.} and Esselman, {Walter J.} and Busik, {Julia V.}",
year = "2007",
month = "1",
day = "1",
doi = "10.1167/iovs.06-0619",
language = "English (US)",
volume = "48",
pages = "18--26",
journal = "Investigative Ophthalmology and Visual Science",
issn = "0146-0404",
publisher = "Association for Research in Vision and Ophthalmology Inc.",
number = "1",

}

TY - JOUR

T1 - Inhibition of cytokine signaling in human retinal endothelial cells through modification of caveolae/lipid rafts by docosahexaenoic acid

AU - Chen, Weiqin

AU - Jump, Donald B.

AU - Esselman, Walter J.

AU - Busik, Julia V.

PY - 2007/1/1

Y1 - 2007/1/1

N2 - PURPOSE. Docosahexaenoic acid (DHA22:6,n3) is the principal n3 polyunsaturated fatty acid (PUFA) in the retina. The authors previously demonstrated that DHA22:6,n3 inhibited cytokine-induced adhesion molecule expression in primary human retinal vascular endothelial (hRVE) cells, the target tissue affected by diabetic retinopathy. Despite the importance of vascular inflammation in diabetic retinopathy, the mechanisms underlying anti-inflammatory effects of DHA22:6,n3 in vascular endothelial cells are not understood. In this study the authors address the hypothesis that DHA22:6,n3 acts through modifying lipid composition of caveolae/lipid rafts, thereby changing the outcome of important signaling events in these specialized plasma membrane microdomains. METHODS. hRVE cells were cultured in the presence or absence of DHA22:6,n3. Isolated caveolae/lipid raft- enriched detergent-resistant membrane domains were prepared using sucrose gradient ultracentrifugation. Fatty acid composition and cholesterol content of caveolae/lipid rafts before and after treatment were measured by HPLC. The expression of Src family kinases was assayed by Western blotting and immunohistochernistry. RESULTS. Disruption of the caveolae/lipid raft structure with a cholesterol-depleting agent, methyl-cyclodextrin (MCD), diminished cytokine-induced signaling in hRVE cells. Growth of hRVE cells in media enriched in DHA22:6,n3 resulted in significant incorporation of DHA 22:6,n3 into the major phospholipids of caveolae/lipid rafts, causing an increase in the unsaturation index in the membrane microdomain. DHA 22:6,n3 enrichment in the caveolae/raft was accompanied by a 70% depletion of cholesterol from caveolae/lipid rafts and displacement of the SFK, Fyn, and c-Yes from caveolae/lipid rafts. Adding water-soluble cholesterol to DHA22:6,n3-treated cells replenished cholesterol in caveolae/lipid rafts and reversed the effect of DHA22:6,n3 on cytokine-induced signaling. CONCLUSIONS. Incorporation of DHA22:6,n3 into fatty acyl chains of phospholipids in caveolae/lipid rafts, followed by cholesterol depletion and displacement of important signaling molecules, provides a potential mechanism for anti-inflammatory effect of DHA22:6,n3 in hRVE cells.

AB - PURPOSE. Docosahexaenoic acid (DHA22:6,n3) is the principal n3 polyunsaturated fatty acid (PUFA) in the retina. The authors previously demonstrated that DHA22:6,n3 inhibited cytokine-induced adhesion molecule expression in primary human retinal vascular endothelial (hRVE) cells, the target tissue affected by diabetic retinopathy. Despite the importance of vascular inflammation in diabetic retinopathy, the mechanisms underlying anti-inflammatory effects of DHA22:6,n3 in vascular endothelial cells are not understood. In this study the authors address the hypothesis that DHA22:6,n3 acts through modifying lipid composition of caveolae/lipid rafts, thereby changing the outcome of important signaling events in these specialized plasma membrane microdomains. METHODS. hRVE cells were cultured in the presence or absence of DHA22:6,n3. Isolated caveolae/lipid raft- enriched detergent-resistant membrane domains were prepared using sucrose gradient ultracentrifugation. Fatty acid composition and cholesterol content of caveolae/lipid rafts before and after treatment were measured by HPLC. The expression of Src family kinases was assayed by Western blotting and immunohistochernistry. RESULTS. Disruption of the caveolae/lipid raft structure with a cholesterol-depleting agent, methyl-cyclodextrin (MCD), diminished cytokine-induced signaling in hRVE cells. Growth of hRVE cells in media enriched in DHA22:6,n3 resulted in significant incorporation of DHA 22:6,n3 into the major phospholipids of caveolae/lipid rafts, causing an increase in the unsaturation index in the membrane microdomain. DHA 22:6,n3 enrichment in the caveolae/raft was accompanied by a 70% depletion of cholesterol from caveolae/lipid rafts and displacement of the SFK, Fyn, and c-Yes from caveolae/lipid rafts. Adding water-soluble cholesterol to DHA22:6,n3-treated cells replenished cholesterol in caveolae/lipid rafts and reversed the effect of DHA22:6,n3 on cytokine-induced signaling. CONCLUSIONS. Incorporation of DHA22:6,n3 into fatty acyl chains of phospholipids in caveolae/lipid rafts, followed by cholesterol depletion and displacement of important signaling molecules, provides a potential mechanism for anti-inflammatory effect of DHA22:6,n3 in hRVE cells.

UR - http://www.scopus.com/inward/record.url?scp=33846898577&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=33846898577&partnerID=8YFLogxK

U2 - 10.1167/iovs.06-0619

DO - 10.1167/iovs.06-0619

M3 - Article

VL - 48

SP - 18

EP - 26

JO - Investigative Ophthalmology and Visual Science

JF - Investigative Ophthalmology and Visual Science

SN - 0146-0404

IS - 1

ER -