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Shapiro, J. B.

Publications and source records attributed to Shapiro, J. B..

2 recordsLinked to original sources

Efficient genetic perturbation of murine sensory neurons in vivo using CRISPR/Cas9

Gene editing using CRISPR/Cas9 in vivo offers a powerful tool to investigate pain mechanisms. We validated the use of conditional knock-in mouse model expressing Streptococcus pyogenes CRISPR associated protein 9 selectively in sensory neurons by crossing with Scn10a-Cre driver. Transgene expression was confirmed in key tissues including the dorsal root ganglia (DRG) and sciatic nerve. To assess in vivo editing efficacy, RNA guides targeting GFP or TRPV1 were intrathecally administered. A dose of 3 {micro}g RNA guides significantly reduced GFP expression, and two rounds of nanoparticle delivery targeting TRPV1 resulted in [~]65% reduction in DRG and [~]55% in sciatic nerve without triggering caspase-3-mediated apoptosis or motor deficits. Edited animals exhibited increased withdrawal latencies to heat and reduced nocifensive behaviors following capsaicin injection. Their responses to capsaicin-evoked thermal hyperalgesia and mechanical allodynia were diminished. This approach enables rapid and efficient sensory neuron-specific CRISPR/Cas9 gene perturbations for pain research in mice. We envisage that this method can be employed both for the exploration of molecular mechanisms underlying nociception and for the validation of therapeutic targets associated with pain.

neuroscience↗

Cellular Dynamics of Skeletal Muscle Regeneration

The function of many organs, including skeletal muscle, depends on its three-dimensional structure. Muscle regeneration therefore requires not only reestablishment of myofibers, but restoration of tissue architecture. Resident muscle stem cells (SCs) are essential for regeneration, but how SCs regenerate muscle architecture is largely unknown. We address this problem using genetic labeling of SCs and whole mount imaging to reconstruct in three dimensions muscle regeneration. Unexpectedly, we found that the residual basement membrane of necrotic myofibers is critical for promoting fusion and orienting regenerated myofibers and myofibers form via two distinct phases of fusion. Furthermore, the centralized myonuclei characteristic of regenerated myofibers are associated with myofibrillogenesis and permanently mark regenerated myofibers. Finally, we elucidate a new cellular mechanism for the formation of branched myofibers, a pathology characteristic of diseased muscle. We provide a new synthesis of the cellular events of regeneration and show these differ from those used during development.

cell biology↗