Adeno-associated virus 2/9 delivery of Cre recombinase in mouse primary afferents

Abstract

Genetically-modified animal models have significantly increased our understanding of the complex central nervous system circuits. Among these models, inducible transgenic mice whose specific gene expression can be modulated through a Cre recombinase/LoxP system are useful to study the role of specific peptides and proteins in a given population of cells. In the present study, we describe an efficient approach to selectively deliver a Cre-GFP to dorsal root ganglia (DRG) neurons. First, mice of different ages were injected in both hindpaws with a recombinant adeno-associated virus (rAAV2/9-CBA-Cre-GFP). Using this route of injection in mice at 5 days of age, we report that approximately 20% of all DRG neurons express GFP, 6 to 8 weeks after the infection. The level of infection was reduced by 50% when the virus was administered at 2 weeks of age. Additionally, the virus-mediated delivery of the Cre-GFP was also investigated via the intrathecal route. When injected intrathecally, the rAAV2/9-CBA-Cre-GFP virus infected a much higher proportion of DRG neurons than the intraplantar injection, with up to 51.6% of infected lumbar DRG neurons. Noteworthy, both routes of injection predominantly transduced DRG neurons over spinal and brain neurons.

In vivo mapping of a GPCR interactome using knockin mice

“…In this model, the Cre-driven removal of the translational STOP cassette makes it possible to rescue the expression of DOPr in a tissue-and/or cell-specific manner. We have previously demonstrated that the recombinant adenoassociated virus rAAV2/9-CBA-Cre-GFP predominantly targeted dorsal root ganglia (DRGs) following intrathecal administration (16). Interestingly, when administered to KO mice, our results showed that the antihyperalgesic effects of DLT II were partially reinstated 6 wk after the viral infection, supporting a role for DOPr expressed in primary afferents in the control of pain induced by a thermal stimulus (Fig.…”

“…In addition, our mice models are different from the recently reported HA-DOPr KI mouse (48), since it can be used to produce conditional KI within specific targeted regions using a tissue-specific Cre recombinase mouse line or viral approaches. This possibility was investigated by the injection of the recombinant adenoassociated virus rAAV2/9-CBA-Cre-GFP, which preferentially targets lumbar DRGs when injected intrathecally (16). In a CFA-induced chronic pain model, we observed that the antihyperalgesic effect of DLT II (specific DOPr agonist) was partially reinstated in KO mice intrathecally injected with the virus, thereby supporting a reexpression of DOPr in the spinal cord, presumably on central terminals of primary afferents.…”

Intraarticular Adeno‐Associated Virus Serotype AAV‐PHP.S–Mediated Chemogenetic Targeting of Knee‐Innervating Dorsal Root Ganglion Neurons Alleviates Inflammatory Pain in Mice

“…However, delivering genes by AAV injection into a peripheral organ to DRG neurons is challenging because of the low transduction capability of AAVs and the large anatomic distances involved in the PNS . A variety of AAV serotypes have shown little efficacy in transducing DRG neurons when injected subcutaneously, intramuscularly, or in an intraplantar manner in adult mice . To date, direct injection into DRG or intrathecal injection are the best ways of transducing DRG neurons.…”

Loss of POMC-mediated antinociception contributes to painful diabetic neuropathy

“…Mice showing less than 20% infected neurons were excluded from the analysis. A detailed characterization of rate of neuron transduction and neuron-specificity for both AAV (1/2) and AAV (9/2) in mouse DRG has been previously described 32 , 86 .…”