Download The Effect of Melatonin on CREB and NF-κB Levels on LPS

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The Effect of Melatonin on CREB and NF-κB Levels on LPS-induced Proinflammatory
Responses in Suprachiasmatic Nucleus Cells
Jay Shah
Mentor: Arezoo Campbell
Melatonin, beyond regulating the circadian cycle, is a powerful neuroprotective antioxidant that
modulates immune responses. To mediate these responses, it is hypothesized that melatonin
regulates NF-κB levels in the brain. For this project, suprachiasmatic nucleus (SCN) 2.2 cells were
chosen. These cells, which express melatonin receptors, were seeded in four groups: 1) Media alone;
2) Melatonin pretreatment only; 3) Lipopolysaccharide (LPS); and 4) Melatonin pretreatment
followed by LPS exposure. We analyzed the activated levels of the transcription factors, NF-κB and
cAMP response element binding protein (CREB)—which has been previously shown to decrease via
the effect of melatonin—using Gel shift mobility assays. Two bands were present and were used to
determine the activation of these two transcription factors. It is hypothesized that they represent celltype dependent isoforms. Band 1, which we hypothesize to be of glial origin, showed elevated levels.
For the second band, which we predict is neuronal, treatment with both Melatonin and LPS
drastically decreased the response. The future aim of this study is to conduct immunocytochemical
assays to provide evidence that the different cell types in culture are responding to the treatment in a
manner dependent on their functions.