COX-2 mRNA levels in AD, PD, cerebrovascular disease, and control cases were each significantly lower than in ALS and were not significantly different from each other.
A total of 7 case-control studies about COX-2rs20417 polymorphisms and AD risk, and 3 studies about COX-2rs689466 and AD risk were included in this meta-analysis.
After transfection by PTGS2 and miR-103 mimic plasmid in PC12 cellular AD model, the total neurite growth was shortened compared with miR-103 mimic group, and cells apoptosis was enhanced which indicated PTGS2 mimic attenuated the influence of miR-103 mimic on progression of AD.
Although the levels of COX-2 and its metabolic product prostaglandin (PG)E2 are elevated in the brain of AD patients, the mechanisms for the development of AD remain unknown.
As NSAIDs inhibit the enzymatic activity of the inflammatory cyclooxygenases COX-1 and COX-2, these findings suggest that downstream prostaglandin signaling pathways function in the preclinical development of AD.
As our sample size was limited, large-scale, well-designed studies are necessary to validate the association between the COX-2 765G>C polymorphism and AD.
Based on our findings, it is unlikely that neuronal COX-2 contributes to pathology in end stage AD; however, COX-2 in other cell types may participate in the inflammation-related response associated with the disease.
Because the inhibition of COX-1 is also known to cause tissue damage in the gastrointestinal system from the resultant reduced cytoprotection, selective COX-2 inhibitors are being investigated and tested clinically as potentially better therapeutics for AD patients.
Because there is extensive evidence that C1q and other complement components are involved in Alzheimer's disease (AD) neurodegeneration, this study advances our understanding of the apparent benefits of COX-2 inhibition in AD.
Beta-adrenergic receptor blockade is also implicated in AD due to its effects on matrix metalloproteinases, mitogen-activated protein kinase pathways, prostaglandins, cyclooxygenase-2, and nitric oxide synthase.
Hence, EP1 might mediate most of the toxicity associated with cyclooxygenase-2 and contribute substantially to the cell death pathways in AD and stroke.
Histopathologically, the alkaloidal fraction-treated 3xTg-AD mice exhibited a significant reduction in tauopathy and astrogliosis, as well as a significant decrease in the proinflammatory marker COX-2 and an increase in pAkt.
Importantly, mice already presented an overexpression of COX-2 at postnatal day 30, before neurodegeneration begins; which suggests that neuroinflammation may underlie the posterior neurodegeneration observed in individuals with Down syndrome and in Ts65Dn mice and could be a factor for the premature appearance of Alzheimer's disease.</i>.
In conclusion, the present results suggest that in DLB nigral COX-2 mRNA expression does not correlate with dopaminergic neurodegeneration and that the slight changes observed in the common type are probably due to the concomitant AD pathology.
In conclusion, the present results suggest that in DLB nigral COX-2 mRNA expression does not correlate with dopaminergic neurodegeneration and that the slight changes observed in the common type are probably due to the concomitant AD pathology.
In summary, our meta-analysis results showed that ABCA1 rs2422493 polymorphism was a risk factor for AD while PTGS2rs20417 variant showed a protective effect on AD risk.
In this sample, the C allele of COX-2 -765 promoter polymorphism is associated with decreased risk of Alzheimer's disease, a finding which further supports the involvement of COX-2 in AD etiology.
It has been reported that inhibition of COX-2 beside traditional effects of NSAIDs, reduces the risk of colorectal, breast and lung cancers and also slow the progress of Alzheimer's disease.Zarghi et al. reported 8-benzoyl-2-(4-(methylsulfonyl)phenyl)quinoline-4-carboxylic acid (AZGH 102) as a novel compound with similar IC50 to celecoxib besides improved selectivity index (COX-1/COX-2 inhibitory potency) in comparison with celecoxib.
Moreover, the expression of both COX-2 and PLA2 appears to be strongly activated during Alzheimer's disease (AD), indicating the importance of inflammatory gene pathways as a response to brain injury.