Autophagy is afundamental cellular homeostatic mechanism, whereby cells autodigest parts oftheir cytoplasm for removal or turnover. Paradoxically, although autophagy is primarily a protective process forthe cell, it can also play a role in cell death. Microglialcells (MC) are resident macrophages in thecentral nervous system (CNS) and have multiple functions, such as phagocytosis,production of growth factors and cytokines, and antigen presentation.

The aim of this study was to evaluate the effects ofautophagy on the production of pro-inflammatory mediators by BV2 MC, and onneuronal viability in a co-culture model.

Autophagy was induced in MC before or after TLR oralpha-synuclein (α-syn) stimulation by rapamycin or trehalose and blocked byusing 3-Methyladenine. Supernatants were isolated and analyzed by ELISA andGriess assay to determine cytokines and nitric oxide (NO) levels, respectively.Autophagic activity was followed by confocal microscopy and WB. Cell death wasevaluated using AnnexinV/propidium iodide staining and subsequent flowcytometric analysis.

Autophagyinduction in BV2 cells before LPS or α-synstimulation downregulated IL1β, IL-6, TNFα and NO production (p<0.01).

Inaddition, we observed in BV2/N2A co-cultures stimulated with LPS or α-syn fibers that induction of autophagy inmicroglial cells rescued LPS and α-syn-inducedneuronal cell death (p<0.05).

Moreover,we wanted to determine if autophagy activity could regulate the phosphorylationstatus (p-) of p38 and ERK1/2, two MAPKs involved in cellular programs such asinflammation and cell death. We observed a reduction in both p-p38 and p-ERK1/2levels after inducing autophagy in MC stimulated with α-syn fibers or LPS (p<0.05).

Despitethe increasing reports studying the effects of autophagy in the CNS, slightlyemphasis is placed on MC. These results suggest that modulation of microglialcells by autophagy could be an important strategy in the context ofneurodegenerative diseases.