A2E selectively induces cox-2 in ARPE-19 and human neural cells.
OBJECTIVE
To investigate the expression of cyclooxygenase (COX)-1, -2, and -3 RNA and protein in retinal pigment epithelial (ARPE-19) cells and in human neural (HN) cells exposed to the stress-inducing cytokines IL-1beta and TNF-a, the oxidizing peroxide H(2)O(2), the combination of TNF-alpha + H(2)O(2), and the lipofuscin fluorophore A2E.


METHODS
Three-week-old ARPE-19 and HN cells were incubated with IL-1beta (10 ng/ml), TNF-alpha (10 ng/ml), H(2)O(2) (0.6 microM), TNF-alpha + H(2)O(2) (10 ng/ml and 0.6 microM), or A2E (10 microM) for 8 hr, after which total RNA and whole cellular proteins were isolated. Cyclooxygenase-1, -2, and -3 RNA and protein levels were quantified using Northern and Western immunoassay.


RESULTS
IL-1beta-, H(2)O(2)-, TNF-alpha-, TNF-alpha + H(2)O(2)-, or A2E-stressed ARPE-19 or HN cells displayed no significant upregulation in COX-1 or COX-3 RNA message abundance; however, significant upregulation was observed in COX-2 RNA message and protein abundance. A2E treatment of HN cells resulted in modest increases in COX-3 protein, an effect that was not observed in ARPE-19 cells.


CONCLUSIONS
COX-2 RNA levels were induced in cytokine-, peroxide-, and A2E-stressed ARPE-19 and HN cells. Lack of induction of COX-3 RNA message by A2E, coupled with increases in COX-3 protein under identical treatment conditions, suggest that significant post-transcriptional or post-translational controls may regulate COX-3 gene expression in HN cells. Stress-induced upregulation of COX-2 gene expression in ARPE-19 and HN cells may play a mechanistic role in promoting proinflammatory and/or pro-oxidative pathology in these tissues.
LSU Neuroscience Center of Excellence and Department of Ophthalmology, Louisiana State University Health Sciences Center School of Medicine in New Orleans, New Orleans, 70112, USA. wlukiw@lsuhsc.edu
Walter J
WJ
Lukiw
Pranab K
PK
Mukherjee
Jian-Guo
JG
Cui
Nicolas G
NG
Bazan
D015152:Blotting, Northern; D015153:Blotting, Western; D051546:Cyclooxygenase 2 / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism; D015870:Gene Expression / Q000187:drug effects*; D006801:Humans; D066298:In Vitro Techniques; D009457:Neuroglia / Q000166:cytology / Q000187:drug effects / Q000201:enzymology*; D010857:Pigment Epithelium of Eye / Q000166:cytology / Q000187:drug effects / Q000201:enzymology*; D011726:Pyridinium Compounds / Q000494:pharmacology*; D012313:RNA / Q000235:genetics*; D012176:Retinoids / Q000494:pharmacology*
C112040:A2-E (N-retinylidene-N-retinylethanolamine); D011726:Pyridinium Compounds; D012176:Retinoids; D012313:RNA; D051546:Cyclooxygenase 2