We show that thick (> 0.5 mm) vertically aligned carbon nanotube films, made by chemical vapour deposition, can be used as biocompatible substrates for the directional alignment of mouse muscle cells where the cells grow on the exposed sides of the films.
This was addressed in a recent study on adult mouse skeletal muscle, where expression of RyR3 resulted in the appearance of abundant Ca2+ sparks, while over expression of RyR1 did not [10].
A similar result was reported in mouse heart muscle, where the injection of 136 nmol/kg IGF-1 i.v. resulted in strong phosphorylation of the receptor, whereas no signal could be detected after i.v. injection of a therapeutic 4 nmol/kg dose [ 44].
Moreover, when transgenic mice expressing the calcineurin inhibitor myocyte-enriched calcineurin-interacting protein 1 (MCIP1) driven by the MCK promoter were crossed with the MEF2-lacZ reporter mice, the mice developed muscles where treadmill running did not induce lacZ expression (Wu et al., 2001).
One example is from mouse muscle progenitors (myoblasts), where Snai1 and Snai2 repress expression from MyoD target promoters and this is required to maintain their progenitor state (Soleimani et al, 2012).
Reviewer 1: The study by Gomez et al. reports that knockout of Lrp4 in all tissues in mice except skeletal muscle (where it is required for survival), causes impairment in hippocampal-dependent learning and memory behavioral tasks, LTP at the Schaffer collateral, and a reduction in spine density in CA1 primary apical dendrites.
In agreement, beta1-syntrophin, a component of the dystrophin-glycoprotein complex (DAPC) that is altered in DMD and BMD, was shown to be a target of miR-222, and its expression was found downregulated in mouse dystrophic muscles where miR-222 levels are increased [ 35].
We conclude that hrGFP is impractical for use as a transduction marker in preclinical, AAV-based RNA interference therapy studies where adult mouse muscle is the target organ.
The effect of overexpression of RIP140 in transgenic mice was examined focusing on the soleus muscle, where endogenous RIP140 levels are low and a putative repressive action may be most clearly observed.
Similarly, correlations of non-muscle human tissue in dataset H3 to mouse dataset M are lower and do not show a significantly higher correlation to any mouse muscle group – with one exception in the ST3 sample profile characterization where among non-muscle human tissue, brain and spinal cord had significantly higher correlation with mouse soleus than with non-soleus muscle profiles.
