Status epilepticus (SE), a prolonged period of continuous or recurring seizures without regaining consciousness, is a condition that can lead to persistent neuroinflammation, neurodegeneration, and aberrant neurogenesis, as well as cognitive and memory impairments. Bone marrow-derived stem cells have shown potential for alleviating the adverse consequences of SE, but clinical therapies based on stem cells face considerable challenges.

Researchers investigated the effects of intranasal administration of extracellular vesicles (EVs) derived from human mesenchymal stem cells in a mouse model of SE. The EVs, called A1-exosomes, have been shown to have robust antiinflammatory properties.

Mice that received exosomes following SE exhibited lower levels of proinflammatory cytokines and microglial activation, and higher levels of antiinflammatory cytokines, in the hippocampus than mice that did not receive exosomes, indicating reduced inflammation in exosome-treated mice.

Mice that received exosomes also lost fewer hippocampal neurons than mice that did not receive exosomes, and did not exhibit the cognitive and memory impairment or abnormal neurogenesis observed in the nonexosome-treated mice following SE.

The results suggest the therapeutic potential of stem cell-derived EVs for preventing chronic hippocampus dysfunction induced by SE, according to the authors.

http://www.pnas.org/content/early/2017/04/05/1703920114