title: PEDF Promotes Biosynthesis of a Novel Anti-inflammatory and Anti-apoptotic Mediator NPD1 in Retinal Pigment Epithelial Cells.
abstract: OBJECTIVE
  Neuroprotectin D1 is a stereospecific cytoprotective messenger synthesized from docosahexaenoic acid in retinal pigment epithelial cells challenged by oxidative stress. A key step in neuroprotectin D1 synthesis is to define how growth factors may modulate its formation and its bioavailability. Here we have explored the action of pigment epithelium derived factor, a neurotrophin made in retinal pigment epithelial cells, on neuroprotectin D1.
  
  
  METHODS
  ARPE-19 cells were serum starved and exposed to TNFα/H(2)O(2) in the presence and absence of pigment epithelium derived factor (10 mg/mL). Cells and incubation media were collected. LC-PDA-MS-MS-based lipidomic analysis was used to identify and quantitate neuroprotectin D1. Immunostaining for BCLxL was performed.
  
  
  RESULTS
  Oxidative stress promotes increases in neuroprotectin D1 levels in ARPE-19 cells, showing a rapid increase up to 6 hrs of incubation of 12 folds measured on cell pellets. Cell media, on the other hand, show time dependent accumulation of neuroprotectin D1 up to 55-fold after 12 hrs incubation. Treatment with 50 nM pigment epithelium derived factor increased such profile by at least two fold. Deuterated docosahexaenoic acid was incorporated to cell membranes and converted into neuroprotectin D1. After cells are exposed to oxidative stress, BCLxL appears to shift to the nucleus of the cell. With the addition of pigment epithelium derived factor and docosahexaenoic acid, this translocation seems to be prevented.
  
  
  CONCLUSIONS
  Here we demonstrate that pigment epithelium derived factor is an activator of neuroprotectin D1 synthesis in ARPE-19 cells exposed to oxidative stress. A major action of pigment epithelium derived factor-stimulated neuroprotectin D1 synthesis shown here is retinal pigment epithelial cytoprotection. Since the retinal pigment epithelial cell is impaired in retinal degeneration, these novel mechanisms potentially may be targeted in macular degeneration and other retinal degenerative diseases as a new therapeutic avenue and may be applicable for neuroprotection in glaucoma and in other neurodegenerative diseases.
authors: Maria A
authors: MA
authors: Reinoso
authors: Pranab
authors: P
authors: Mukherjee
authors: Victor
authors: V
authors: Marcheselli
authors: Donald
authors: D
authors: Bergsma
authors: Richard
authors: R
authors: Hesse
authors: Nicolas
authors: N
authors: Bazan
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