Diverse regulation of retinal pigment epithelium phagocytosis of photoreceptor outer segments by calcium-independent phospholipase A₂, group VIA and secretory phospholipase A₂, group IB

TY - JOUR

T1 - Diverse regulation of retinal pigment epithelium phagocytosis of photoreceptor outer segments by calcium-independent phospholipase A₂, group VIA and secretory phospholipase A₂, group IB

AU - Zhan, Chen

AU - Wang, Jinmei

AU - Kolko, Miriam

PY - 2012/10

Y1 - 2012/10

N2 - PURPOSE: To investigate the roles of the phospholipases A(2) (PLA(2)) subtypes, iPLA(2)-VIA and sPLA(2)-IB in retinal pigment epithelium (RPE) phagocytosis of photoreceptor outer segments (POS) and to explore a possible interaction between sPLA(2)-IB and iPLA(2)-VIA in the RPE.METHODS: To explore the role of iPLA(2)-VIA in RPE phagocytosis of POS, experiments with iPLA(2)-VIA vector transfection, iPLA(2)-VIA(-/-) knockout (KO) mice, and iPLA(2)-VIA inhibition by bromoenol lactone (BEL) were done. Exogenous addition of sPLA(2)-IB was used to investigate the role of sPLA(2)-IB in RPE phagocytosis. A Luciferase Reporter Vector containing the iPLA(2)-VIA promoter was used to study the effects of sPLA(2)-IB on the iPLA(2)-VIA promoter.RESULTS: ARPE-19 and primary mouse RPE cells transfected with iPLA(2)-VIA showed increased phagocytosis. Phagocytosis was reduced in primary mouse RPE inhibited with BEL and in RPE from KO mice. Exogenous addition of enzymatically active and inactive sPLA(2)-IB reduced phagocytosis in ARPE-19 and primary mouse RPE cells. Finally, sPLA(2)-IB did not seem to affect the iPLA(2)-VIA promoter.CONCLUSION: The present study confirms the involvement of iPLA(2)-VIA in efficient RPE phagocytosis of POS, while exogenously added sPLA(2)-IB decreases phagocytosis regardless of enzymatic activity. No apparent interaction between iPLA(2)-VIA and sPLA(2)-IB was found.

AB - PURPOSE: To investigate the roles of the phospholipases A(2) (PLA(2)) subtypes, iPLA(2)-VIA and sPLA(2)-IB in retinal pigment epithelium (RPE) phagocytosis of photoreceptor outer segments (POS) and to explore a possible interaction between sPLA(2)-IB and iPLA(2)-VIA in the RPE.METHODS: To explore the role of iPLA(2)-VIA in RPE phagocytosis of POS, experiments with iPLA(2)-VIA vector transfection, iPLA(2)-VIA(-/-) knockout (KO) mice, and iPLA(2)-VIA inhibition by bromoenol lactone (BEL) were done. Exogenous addition of sPLA(2)-IB was used to investigate the role of sPLA(2)-IB in RPE phagocytosis. A Luciferase Reporter Vector containing the iPLA(2)-VIA promoter was used to study the effects of sPLA(2)-IB on the iPLA(2)-VIA promoter.RESULTS: ARPE-19 and primary mouse RPE cells transfected with iPLA(2)-VIA showed increased phagocytosis. Phagocytosis was reduced in primary mouse RPE inhibited with BEL and in RPE from KO mice. Exogenous addition of enzymatically active and inactive sPLA(2)-IB reduced phagocytosis in ARPE-19 and primary mouse RPE cells. Finally, sPLA(2)-IB did not seem to affect the iPLA(2)-VIA promoter.CONCLUSION: The present study confirms the involvement of iPLA(2)-VIA in efficient RPE phagocytosis of POS, while exogenously added sPLA(2)-IB decreases phagocytosis regardless of enzymatic activity. No apparent interaction between iPLA(2)-VIA and sPLA(2)-IB was found.

KW - Animals

KW - Cattle

KW - Cell Line

KW - Cell Survival

KW - Gene Expression Regulation, Enzymologic

KW - Genes, Reporter

KW - Group IB Phospholipases A2

KW - Group VI Phospholipases A2

KW - Humans

KW - Mice

KW - Mice, 129 Strain

KW - Mice, Inbred C57BL

KW - Mice, Knockout

KW - Phagocytosis

KW - Primary Cell Culture

KW - Promoter Regions, Genetic

KW - RNA, Messenger

KW - Retinal Photoreceptor Cell Outer Segment

KW - Retinal Pigment Epithelium

U2 - 10.3109/02713683.2012.691598

DO - 10.3109/02713683.2012.691598

M3 - Journal article

C2 - 22680611

SN - 0271-3683

VL - 37

SP - 930

EP - 940

JO - Current Eye Research

JF - Current Eye Research

IS - 10

ER -