Gene regulation in activated microglia by adenosine A3 receptor agonists. A transcriptomics analysis.

Most neurodegenerative disorders, including the two most common, Alzheimer's disease (AD) and Parkinson's disease (AD), course with activation of microglia, the resident innate immune cells of central nervous system. A3 adenosine receptor (A3R) agonists have been proposed to be neuroprotective by regulating the phenotype of activated microglia. RNAseq was performed using samples isolated from lipopolysaccharide/interferon-? activated microglia treated with 2-Cl-IB-MECA, a selective A3R agonist. The results showed that the number of negatively regulated genes in the presence of 2-Cl-IB-MECA was greater than the number of positively regulated genes. Gene ontology enrichment analysis showed regulation of genes participating in several cell processes, including those involved in immune-related events. Analysis of known and predicted protein-protein interactions showed that Smad3 and Sp1 are transcription factors whose genes are regulated by A3R activation. Under the conditions of cell activation and agonist treatment regimen, 2-Cl-IB-MECA did not lead to any tendency to favor the expression of genes related to neuroprotective microglia (M2). Overall design: Cells were maintained in a humid atmosphere of 5% CO2 at 37ºC and were used for RNA extraction after 15 days of culture. Cells were activated for 48 h with 0.01% (v/v) LPS and 0.002% (v/v) IFN-? in Dulbecco's modified Eagle medium and, at 24, 32 and 40 h, vehicle or 200 nM 2-Cl-IB-MECA was added.