Multivariate evaluation of the functional recovery obtained by the overexpression of utrophin in skeletal muscles of the mdx mouse.

This paper summarizes the various aspects of functional recovery obtained in dystrophin-deficient muscles of the mdx mice where utrophin was overexpressed. This includes preliminary results on tetracycline-controlled expression of utrophin. It is shown that overexpression of utrophin leads to major functional improvements and that full-length utrophin is more efficient than truncated utrophin, missing a part of the central rod-segment. A generalized way of presenting improvements obtained by any treatment in the form of a 'recovery score' is emphasized. The quantitative aspect of the replacement of dystrophin by utrophin is discussed.