Identification of intracellular phospholipases A2 in the human eye: involvement in phagocytosis of photoreceptor outer segments.

Miriam Kolko; Jinmei Wang; Chen Zhan; Kristian A Poulsen; Jan Ulrik Prause; Mogens Holst Nissen; Steffen Heegaard; Nicolas G Bazan

doi:10.1167/iovs.06-0865

Identification of intracellular phospholipases A2 in the human eye: involvement in phagocytosis of photoreceptor outer segments.

Miriam Kolko, Jinmei Wang, Chen Zhan, Kristian A Poulsen, Jan Ulrik Prause, Mogens Holst Nissen, Steffen Heegaard, Nicolas G Bazan

32 Citations (Scopus)

Abstract

PURPOSE: To identify intracellular phospholipases A(2) (PLA(2)) in the human retina and to explore the role of these enzymes in human retinal pigment epithelium (RPE) phagocytosis of photoreceptor outer segments (POS). METHODS: PCR amplification and Western blot analysis were used to identify mRNA and protein expression of intracellular PLA(2) subtypes in the retinal pigment epithelial cell line ARPE-19. Immunohistochemical staining of normal human eye sections was performed to reveal the cellular location of the enzymes. A model of RPE phagocytosis of POS was used to explore the role of intracellular PLA(2) in phagocytosis. An activity assay was used to evaluate PLA(2) activity, and inhibitors of specific PLA(2) were applied to evaluate the role of PLA(2) in RPE phagocytosis. RESULTS: Genes encoding calcium-independent (i)PLA(2), group VIA; calcium-dependent cytosolic (c)PLA(2), groups IVA, IVB, and IVC; and iPLA(2), group VIB, were identified in the human RPE cell line ARPE-19. Furthermore, protein of iPLA(2)-VIA, cPLA(2)-IVA, and iPLA(2)-VIB were identified in ARPE-19 cells and in various parts of the normal human eye. iPLA(2)-VIA protein levels were upregulated during phagocytosis, and iPLA(2)-VIA activity was found to be specifically increased 12 hours after ARPE-19 cells were fed with POS. Finally, RPE phagocytosis was inhibited by the iPLA(2)-VIA inhibitor bromoenol lactone. CONCLUSIONS: Various intracellular PLA(2) subtypes are present in the human retina. iPLA(2)-VIA may play an important role in the regulation of RPE phagocytosis of POS and may also be involved in the regulation of photoreceptor cell renewal.

Original language	English
Journal	Investigative Ophthalmology & Visual Science
Volume	48
Issue number	3
Pages (from-to)	1401-9
Number of pages	8
ISSN	0146-0404
DOIs	https://doi.org/10.1167/iovs.06-0865
Publication status	Published - 2007

Access to Document

10.1167/iovs.06-0865

Cite this

@article{3450d300b7a211ddae57000ea68e967b,

title = "Identification of intracellular phospholipases A2 in the human eye: involvement in phagocytosis of photoreceptor outer segments.",

abstract = "PURPOSE: To identify intracellular phospholipases A(2) (PLA(2)) in the human retina and to explore the role of these enzymes in human retinal pigment epithelium (RPE) phagocytosis of photoreceptor outer segments (POS). METHODS: PCR amplification and Western blot analysis were used to identify mRNA and protein expression of intracellular PLA(2) subtypes in the retinal pigment epithelial cell line ARPE-19. Immunohistochemical staining of normal human eye sections was performed to reveal the cellular location of the enzymes. A model of RPE phagocytosis of POS was used to explore the role of intracellular PLA(2) in phagocytosis. An activity assay was used to evaluate PLA(2) activity, and inhibitors of specific PLA(2) were applied to evaluate the role of PLA(2) in RPE phagocytosis. RESULTS: Genes encoding calcium-independent (i)PLA(2), group VIA; calcium-dependent cytosolic (c)PLA(2), groups IVA, IVB, and IVC; and iPLA(2), group VIB, were identified in the human RPE cell line ARPE-19. Furthermore, protein of iPLA(2)-VIA, cPLA(2)-IVA, and iPLA(2)-VIB were identified in ARPE-19 cells and in various parts of the normal human eye. iPLA(2)-VIA protein levels were upregulated during phagocytosis, and iPLA(2)-VIA activity was found to be specifically increased 12 hours after ARPE-19 cells were fed with POS. Finally, RPE phagocytosis was inhibited by the iPLA(2)-VIA inhibitor bromoenol lactone. CONCLUSIONS: Various intracellular PLA(2) subtypes are present in the human retina. iPLA(2)-VIA may play an important role in the regulation of RPE phagocytosis of POS and may also be involved in the regulation of photoreceptor cell renewal.",

author = "Miriam Kolko and Jinmei Wang and Chen Zhan and Poulsen, {Kristian A} and Prause, {Jan Ulrik} and Nissen, {Mogens Holst} and Steffen Heegaard and Bazan, {Nicolas G}",

note = "Keywords: Blotting, Western; Cell Line; Enzyme Inhibitors; Eye; Humans; Immunoenzyme Techniques; Microscopy, Confocal; Phagocytosis; Phospholipases A; Pigment Epithelium of Eye; Polymerase Chain Reaction; RNA, Messenger; Rod Outer Segments; Tissue Distribution",

year = "2007",

doi = "10.1167/iovs.06-0865",

language = "English",

volume = "48",

pages = "1401--9",

journal = "Investigative Ophthalmology & Visual Science",

issn = "0146-0404",

publisher = "Association for Research in Vision and Ophthalmology",

number = "3",

}

TY - JOUR

T1 - Identification of intracellular phospholipases A2 in the human eye: involvement in phagocytosis of photoreceptor outer segments.

AU - Kolko, Miriam

AU - Wang, Jinmei

AU - Zhan, Chen

AU - Poulsen, Kristian A

AU - Prause, Jan Ulrik

AU - Nissen, Mogens Holst

AU - Heegaard, Steffen

AU - Bazan, Nicolas G

N1 - Keywords: Blotting, Western; Cell Line; Enzyme Inhibitors; Eye; Humans; Immunoenzyme Techniques; Microscopy, Confocal; Phagocytosis; Phospholipases A; Pigment Epithelium of Eye; Polymerase Chain Reaction; RNA, Messenger; Rod Outer Segments; Tissue Distribution

PY - 2007

Y1 - 2007

N2 - PURPOSE: To identify intracellular phospholipases A(2) (PLA(2)) in the human retina and to explore the role of these enzymes in human retinal pigment epithelium (RPE) phagocytosis of photoreceptor outer segments (POS). METHODS: PCR amplification and Western blot analysis were used to identify mRNA and protein expression of intracellular PLA(2) subtypes in the retinal pigment epithelial cell line ARPE-19. Immunohistochemical staining of normal human eye sections was performed to reveal the cellular location of the enzymes. A model of RPE phagocytosis of POS was used to explore the role of intracellular PLA(2) in phagocytosis. An activity assay was used to evaluate PLA(2) activity, and inhibitors of specific PLA(2) were applied to evaluate the role of PLA(2) in RPE phagocytosis. RESULTS: Genes encoding calcium-independent (i)PLA(2), group VIA; calcium-dependent cytosolic (c)PLA(2), groups IVA, IVB, and IVC; and iPLA(2), group VIB, were identified in the human RPE cell line ARPE-19. Furthermore, protein of iPLA(2)-VIA, cPLA(2)-IVA, and iPLA(2)-VIB were identified in ARPE-19 cells and in various parts of the normal human eye. iPLA(2)-VIA protein levels were upregulated during phagocytosis, and iPLA(2)-VIA activity was found to be specifically increased 12 hours after ARPE-19 cells were fed with POS. Finally, RPE phagocytosis was inhibited by the iPLA(2)-VIA inhibitor bromoenol lactone. CONCLUSIONS: Various intracellular PLA(2) subtypes are present in the human retina. iPLA(2)-VIA may play an important role in the regulation of RPE phagocytosis of POS and may also be involved in the regulation of photoreceptor cell renewal.

AB - PURPOSE: To identify intracellular phospholipases A(2) (PLA(2)) in the human retina and to explore the role of these enzymes in human retinal pigment epithelium (RPE) phagocytosis of photoreceptor outer segments (POS). METHODS: PCR amplification and Western blot analysis were used to identify mRNA and protein expression of intracellular PLA(2) subtypes in the retinal pigment epithelial cell line ARPE-19. Immunohistochemical staining of normal human eye sections was performed to reveal the cellular location of the enzymes. A model of RPE phagocytosis of POS was used to explore the role of intracellular PLA(2) in phagocytosis. An activity assay was used to evaluate PLA(2) activity, and inhibitors of specific PLA(2) were applied to evaluate the role of PLA(2) in RPE phagocytosis. RESULTS: Genes encoding calcium-independent (i)PLA(2), group VIA; calcium-dependent cytosolic (c)PLA(2), groups IVA, IVB, and IVC; and iPLA(2), group VIB, were identified in the human RPE cell line ARPE-19. Furthermore, protein of iPLA(2)-VIA, cPLA(2)-IVA, and iPLA(2)-VIB were identified in ARPE-19 cells and in various parts of the normal human eye. iPLA(2)-VIA protein levels were upregulated during phagocytosis, and iPLA(2)-VIA activity was found to be specifically increased 12 hours after ARPE-19 cells were fed with POS. Finally, RPE phagocytosis was inhibited by the iPLA(2)-VIA inhibitor bromoenol lactone. CONCLUSIONS: Various intracellular PLA(2) subtypes are present in the human retina. iPLA(2)-VIA may play an important role in the regulation of RPE phagocytosis of POS and may also be involved in the regulation of photoreceptor cell renewal.

U2 - 10.1167/iovs.06-0865

DO - 10.1167/iovs.06-0865

M3 - Journal article

C2 - 17325189

SN - 0146-0404

VL - 48

SP - 1401

EP - 1409

JO - Investigative Ophthalmology & Visual Science

JF - Investigative Ophthalmology & Visual Science

IS - 3

ER -

Identification of intracellular phospholipases A2 in the human eye: involvement in phagocytosis of photoreceptor outer segments.

Abstract

Access to Document

Fingerprint

Cite this