Biology subjects

Arroyo, D. S.

Publications and source records attributed to Arroyo, D. S..

2 recordsLinked to original sources

bioRxiv2020

Systemic sterile induced-co-expression of IL-12 and IL-18 drives IFN-γ-dependent activation of microglia and recruitment of MHC-II-expressing inflammatory monocytes into the brain.

The development of neuroinflammation, as well as the progression of several neurodegenerative diseases, has been associated with the activation and mobilization of the peripheral immune system due to systemic inflammation. However, the mechanism by which this occurs remains unclear. Herein, we addressed the effect of systemic, endotoxin-free induced-co-expression of IL-12 and IL-18 in the establishment of a novel cytokine-mediated model of neuroinflammation. Following peripheral hydrodynamic shear of IL-12 plus IL-18 cDNAs in C57BL/6 mice, we induced systemic and persistent level of IL-12, which in turn promoted the elevation of circulating pro-inflammatory cytokines TNF- and IFN-{gamma}, accompanied with splenomegaly. Moreover, even though we identified an increased gene expression of both TNF- and IFN-{gamma} in the brain, only TNF- was shown to be dispensable, revealing an IFN-{gamma}-dependent activation of microglia and the recruitment of leukocytes, particularly of highly activated inflammatory monocytes. Taken together, our results argue for a systemic cytokine-mediated establishment and development of neuroinflammation, having identified IFN-{gamma} as a potential target for immunotherapy.

immunology↗

bioRxiv2017

Alpha-synuclein fibrils induce autophagy in microglial cells as a consequence of lysosomal damage.

Autophagy is a constitutive lysosomal catabolic pathway that degrades damaged organelles and protein aggregates. In Parkinsons disease, the synaptic protein alpha-synuclein (AS) accumulates in neuronal cell bodies and axons. Recent studies indicate that aggregation-prone proteins can spread to other brain cells - such as glia - contributing to progressive deterioration.\n\nAlthough autophagic dysfunction and protein aggregation have been linked to several neurodegenerative disorders, exact mechanisms are not clear and most work was done in neurons and not on microglial cells.\n\nHere we report that AS fibrils but not monomers induce lysosomal damage and autophagy in microglial cells and we extensively characterized the dynamics of this response by both live-cell imaging and correlative light-electron microscopy (CLEM). In addition, we found that autophagy inhibition in these cells impairs mitochondrial quality and leads to microglial cell death. We propose that AS accumulation in lysosomes leads to lysosomal damage, which in turn activates canonical autophagy as a rescue mechanism.\n\nOur results provide novel findings about the interaction between AS and the autophagy pathway in microglial cells, which may be important for targeting protein misfolding-associated neurodegenerative diseases.

cell biology↗