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.
Lukiw
Walter J
WJ
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
Mukherjee
Pranab K
PK
Cui
Jian-Guo
JG
Bazan
Nicolas G
NG
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