Modified adeno‐associated virus targets the bacterial enzyme chondroitinase ABC to select mouse neuronal populations in vivo using the Cre‐LoxP system

Autor: Bernd Gloss, Kelly E. Carstens, Georgia M. Alexander, Serena M. Dudek
Rok vydání: 2020
Předmět:
Zdroj: The European Journal of Neuroscience
ISSN: 1460-9568
0953-816X
DOI: 10.1111/ejn.15050
Popis: Current methods of experimentally degrading the specialized extracellular matrix (ECM), perineuronal nets (PNNs) have several limitations. Genetic knockout of ECM components typically has only partial effects on PNNs, and knockout of the major ECM component aggrecan is lethal in mice. Direct injection of the chondroitinase ABC (ChABC) enzyme into the mammalian brain is effective at degrading PNNs in vivo but this method typically lacks consistent, localized spatial targeting of PNN degradation. PNNs also regenerate within weeks after a ChABC injection, thus limiting the ability to perform long‐term studies. Previous work has demonstrated that viral delivery of ChABC in mammalian neurons can successfully degrade PNNs for much longer periods, but the effects are similarly diffuse beyond the injection site. In an effort to gain cell‐specific targeting of ChABC, we designed an adeno‐associated virus encoding ChABC under the control of the Cre‐LoxP system. We show that this virus is effective at targeting the synthesis of ChABC to Cre‐expressing mouse neurons in vivo. Although ChABC expression is localized to the Cre‐expressing neurons, we also note that ChABC is apparently trafficked and secreted at projection sites, as was previously reported for the non‐Cre dependent construct. Overall, this method allows for cell‐specific targeting of ChABC and long‐term degradation of PNNs, which will ultimately serve as an effective tool to study the function of cell‐autonomous regulation of PNNs in vivo. This novel approach may also aid in determining whether specific, long‐term PNN loss is an appropriate strategy for treatment of neurodevelopmental disorders associated with PNN pathology.
Cre‐Dependent AAV‐ChABC Construct: To express chondroitinaseABC (ChABC) in a Cre‐recombinase dependent way, a shuttle plasmid containing a double floxed mCherry under the control of human synapsin promoter was used for the viral vector backbone, pAAV‐hSyn‐DIO‐mCherry. We tested this virus in mice expressing a tamoxifen‐regulated Cre recombinase in hippocampal area CA2.fx1
Databáze: OpenAIRE
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