Increase in Autophagy and amyloid beta uptake in ApoE expressing astrocytes after Calpain knock down by CRISPR-Cas9

ConclusionWe used the CRISPR-Cas9 system to knock down the small subunit of the calpain protein in mice astrocytes expressing either the human ApoE3 or ApoE4 alleles. We then investigated, the resulting effects of the Calpain knock down on the expression of autophagy-related proteins and on the uptake of fluorescent Aβ.We found that the levels of mitofusin1, a protein responsible for the fusion and integrity of the mitochondria and p62 a protein that undergoes degradation during autophagy, are higher in the ApoE4 compared to ApoE3. However, in astrocytes treated with CRISPR-Cas9, which reduced the levels calpain by 75%, the levels of both mitofusin1 and p62 were significantly reduced in the ApoE4 astrocytes and were similar to those of ApoE3 astrocytes. No change in these protein levels was found when ApoE3 astrocytes were treated with the CRISPR-Cas9. These results suggest higher autophagy and mitochondrial fusion in the CRISPR-Cas9 treated ApoE4 cells. Moreover, the Calpain directed CRISPR-Cas9 treatment increased the levels of Aβ uptake in both, ApoE4 and ApoE3 astrocytes.Improving the astrocyte capacity to clear the accumulated Aβ by knocking down Calpain, might be an interesting and new approach for a possible treatment of some aspects of the AD pathology.

Source: Cytotherapy - May 24, 2019 Category: Cytology Source Type: research