Activation of phospholipase A2 and MAP kinases by oxidized low-density lipoproteins in immortalized GP8.39 endothelial cells

Lupo, Gabriella; Nicotra, Ambra; Giurdanella, Giovanni; Anfuso, Carmelina Daniela; Romeo, Loriana; Biondi, Giovanni; Tirolo, Cataldo; Marchetti, Bianca; Ragusa, N.; Alberghina, Mario

doi:10.1016/j.bbalip.2005.05.008

Cited by 42 publications

(33 citation statements)

References 49 publications

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“…There are several reports indicating that cPLA 2 may be a substrate for PKC phosphorylating activity (17,28). Our recent work has also provided in vitro evidence that PKC upstream activates cPLA 2 after stimulation of ECs by oxidized LDL or of pericytes by b-amyloid peptides (29,30). To date, direct evidence for any of the PKC isoforms being involved in the signaling pathway during endothelial cell-pericyte coupling has not been defined.…”

mentioning

confidence: 96%

“…The cell line was already characterized, and our cell cultures were prepared and characterized according to previously described procedures (31,32). Morphological changes and cell viability determined by [3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyl-tetrazolium bromide] test were assessed as reported previously (29,33). Pure microvessel pericyte cultures were prepared from bovine retinas as described previously (34).…”

Section: Cell Culturesmentioning

confidence: 99%

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Endothelial cell-pericyte cocultures induce PLA2 protein expression through activation of PKCα and the MAPK/ERK cascade

Anfuso

Lupo

Romeo

et al. 2007

Journal of Lipid Research

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Little is known about the regulatory mechanisms of endothelial cell (EC) proliferation by retinal pericytes and vice versa. In a model of coculture with bovine retinal pericytes lasting for 24 h, rat brain ECs showed an increase in arachidonic acid (AA) release, whereas Western blot and RT-PCR analyses revealed that ECs activated the protein expression of cytosolic phospholipase A 2 (cPLA 2 ) and its phosphorylated form and calcium-independent intracellular phospholipase A 2 (iPLA 2 ). No activation of the same enzymes was seen in companion pericytes. In ECs, the protein level of phosphorylated extracellular signal-regulated kinase (ERK) 1/2 was also enhanced significantly, a finding not observed in cocultured pericytes. The expression of protein kinase C-a (PKCa) and its phosphorylated form was also enhanced in ECs. Wortmannin, LY294002, and PD98059, used as inhibitors of upstream kinases (the PI3-kinase/Akt/PDK1 or MEK-1 pathway) in cultures, markedly attenuated AA release and the expression of phosphorylated forms of endothelial cPLA 2 , PKCa, and ERK1/2. By confocal microscopy, activation of PKCa in perinuclear regions of ECs grown in coculture as well as strong activation of cPLA 2 in ECs taken from a model of mixed culture were clearly observed. However, no increased expression of both enzymes was found in cocultured pericytes. Our findings indicate that a sequential activation of PKCa contributes to endothelial ERK1/2 and cPLA 2 phosphorylation induced by either soluble factors or direct cell-tocell contact, and that the PKCa-cPLA 2 pathway appears to play a key role in the early phase of EC-pericyte interactions regulating blood retina or blood-brain barrier maturation.-

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mentioning

confidence: 96%

Section: Cell Culturesmentioning

confidence: 99%

Endothelial cell-pericyte cocultures induce PLA2 protein expression through activation of PKCα and the MAPK/ERK cascade

Anfuso

Lupo

Romeo

et al. 2007

Journal of Lipid Research

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“…Intracellular membrane-associated calcium-independent phospholipase A2-Á (PNPLA8 or iPLA2-Á) is lately upregulated at 5 and 8 h pt (3.8-and 2.7-fold) via MAPK pathways and its activity is linked with the stimulation of PKC-ERK-p38-JNK pathways (71). Induced by ROS in ER and mitochondria (67)(68)(69), possibly as protection against ROS to prevent or repair oxidant-induced cell death and lipid peroxidation (67), it has an effect on the permeability transition of mitochondria and the release of intermembrane space proteins (69).…”

Section: Ros Affect Ermentioning

confidence: 99%

“…On the other hand, PNPLA8 seems to be induced via MAPK pathways (71) as protection against ROS to prevent or repair oxidant-induced cell death and lipid peroxidation (67). The stimulation of PKC-ERKp38-JNK pathways is linked with its activity (71). PNPLA8 is also involved in clearance of apoptotic cells by generating, in a caspase-3-dependent fashion, the phospholipid lysophosphatidylcholin (LPC) mediated attraction of monocytic cells to apoptotic cells (72).…”

Section: Pnpla8 Patatin-like Phospholipase Domain Containing 8 [Intrmentioning

confidence: 99%

Time-resolved gene expression profiling of human squamous cell carcinoma cells during the apoptosis process induced by photodynamic treatment with hypericin

Verwanger¹

2009

Int J Oncol

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Abstract. Hypericin is used as a powerful naturally occurring photosensitizer in photodynamic therapy (PDT). Activated by visible light, it kills tumour cells and tissues via generation of reactive oxygen species (ROS). Depending on the protocol, apoptotic cell death can be achieved very effectively by hypericin-PDT. To analyze the fundamental molecular mechanisms leading to apoptosis induced by photodamage especially with regard to human skin cancer cells, we studied the alteration of the gene expression pattern in the human squamous cell carcinoma cell line A-431 at 1.5, 3, 5 and 8 h after hypericin-PDT by cDNA-macroarray technique. Radioactively labelled samples were hybridized onto macroarray filters containing PCR products of 9738 ESTs of the Incyte Human UniGEM Microarray clone set. In total, 168 genes were found to be differentially upregulated and 45 downregulated. Verification of expression changes of 45 genes of interest was performed by quantitative real-time PCR. Due to the observed significant expression changes the following can be concluded: lipoprotein receptor-mediated endocytosis could play a role in the uptake of lipophilic hypericin. Extracellular signal transduction to the cell is reduced, cell detachment facilitated, changes of the morphology, cytoskeleton and formation of apoptotic bodies occur. The promotion of p38 MAPK , ERK, JNK and Ras signalling pathways supports survival and/or apoptosis. Switches between life and death could be the strongly upregulated transcription factors c-jun and FOSB as well as the MAPKphosphatase 1 DUSP-1, possibly activated via H3 histone modifications. ROS activate ER-stress pathways or adaptive response, and provoke damage protection against ROS, partly in a cell-type specific way.

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“…In the in vitro model of control blood brain barrier or tumor-conditioned blood brain barrier (see Fig. 2, panel b-2, c-3), 48 hours after incubation ECs were scraped from the insert with a rubber policeman, and lysates were resolved by SDS/PAGE (Lupo et al, 2005). Expressed proteins were independently revealed with cPLA 2 , p-cPLA 2 , PKCα, COX-2 or p-ERK monoclonal antibodies, and iPLA 2 , p-PKCα, COX-1 or ERK1/2 polyclonal antibodies.…”

Section: Phospholipase a 2 Activationmentioning

confidence: 99%

Melanoma-Induced Endothelial Cell Growth Involves Phospholipase A2 and COX2 Upregulation

Alberghina¹,

Motta²,

Lupo³

et al. 2011

Breakthroughs in Melanoma Research

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Activation of phospholipase A2 and MAP kinases by oxidized low-density lipoproteins in immortalized GP8.39 endothelial cells

Cited by 42 publications

References 49 publications

Endothelial cell-pericyte cocultures induce PLA2 protein expression through activation of PKCα and the MAPK/ERK cascade

Endothelial cell-pericyte cocultures induce PLA2 protein expression through activation of PKCα and the MAPK/ERK cascade

Time-resolved gene expression profiling of human squamous cell carcinoma cells during the apoptosis process induced by photodynamic treatment with hypericin

Melanoma-Induced Endothelial Cell Growth Involves Phospholipase A2 and COX2 Upregulation

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