Lipopolysaccharide is an endotoxin to induce sickness behavior in several animal models to explore the link between immune activation and cognition. Neuroinflammation playing a pivotal role in disease progress is evidently influenced by sphingosine-1-phosphate. As one of the sphingosine analogs in clinical use for multiple sclerosis, fingolimod (FTY720) was shown to substantially affect gene expression profile in the context of AD in our previous experiments. The present study was designed to evaluate the drug efficacy in the context of the mere inflammatory context leading to memory impairment. FTY720 was repeatedly administered for a few days before or after intracerebral lipopolysaccharide (LPS) injection in rats. Animal's brains were then assigned to histological as well as multiplex mRNA assay following memory performance test. Both FTY720 pre-treatment and post-treatment were similarly capable of ameliorating LPS-induced memory impairment as assessed by passive avoidance test. Such amending effects may be partly accountable by the concomitant alterations in transcriptional levels of mitogen-activated protein kinases as well as inflammatory genes determined by QuantiGene Plex analysis. These findings confirming FTY720 application benefits suggest its efficacy may not differ significantly while considered either as a preventive or as a therapeutic approach against neuroinflammation.
Alzheimer's disease (AD) as a neurodegenerative brain disorder is the most common cause of dementia. To date, there is no causative treatment for AD and there are few preventive treatments either. The sphingosine-1-phosphate receptor modulator FTY720 (fingolimod) prevents lymphocytes from contributing to an autoimmune reaction and has been approved for multiple sclerosis treatment. In concert with other studies showing the anti-inflammatory and protective effect of FTY720 in some neurodegenerative disorders like ischemia, we have recently shown that FTY720 chronic administration prevents from impairment of spatial learning and memory in AD rats. Here FTY720 was examined on AD rats in comparison to the only clinically approved NMDA receptor antagonist, Memantine. Passive avoidance task showed significant memory restoration in AD animals received FTY720 comparable to Memantine. Upon gene profiling by QuantiGene Plex, this behavioral outcomes was concurrent with considerable alterations in some genes transcripts like that of mitogen activated protein kinases (MAPKs) and some inflammatory markers that may particularly account for the detected decline in hippocampal neural damage or memory impairment associated with AD. From a therapeutic standpoint, our findings conclude that FTY720 may suggest new opportunities for AD management probably based on several modulatory effects on genes involved in cell death or survival.