Rescue From Respiratory Dysfunction by Transduction of Full-length Dystrophin to Diaphragm via the Peritoneal Cavity in Utrophin/Dystrophin Double Knockout Mice

Abstract

Duchenne muscular dystrophy (DMD) is an inherited severe muscle wasting disorder with, thus far, no effective therapy. DMD causes respiratory and cardiac failure as well as muscle wastage. Among the various symptoms, respiratory insufficiency is a major cause of death in DMD patients at about 20 years of age. So, naturally, the improvement of respiratory function will extend the patient's life. We report here, for the first time, a sensitive procedure using whole-body plethysmography to monitor respiratory parameters detected in the utrophin/dystrophin double knockout mouse (dko mouse), showing quite similar systemic symptoms to human DMD including restrictive ventilatory impairment. Furthermore, we show that a highly efficient dystrophin-transduction to the dko's diaphragm--achieved by simple intraperitoneal injection of a helper-dependent adenovirus vector (HDAdv) containing the full-length dystrophin expression cassette--provided beneficial results. In spite of dystrophin expression only in the diaphragm, this focal gene transfer could result in the rescue from ventilatory impairment (increased tidal volume (TV) and improvement of compensatory hyperpnea). Our result suggests that a DMD patient's mortal ventilatory impairment may be improved via technically easy means through the intraperitoneal injection of HDAdv.

Animal models of Duchenne muscular dystrophy: from basic mechanisms to gene therapy

“…It has been used to express the full-length dystrophin cDNA ( Haecker et al, 1996 ; Kochanek et al, 1996 ; Kumar-Singh and Chamberlain, 1996 ). Tests conducted in mdx and utrophin/dystrophin dko mice have yielded promising results ( Clemens et al, 1996 ; DelloRusso et al, 2002 ; Ishizaki et al, 2011 ; Kawano et al, 2008 ). The current challenges are the host immune response to the adenoviral capsid and the contaminating wild-type adenovirus.…”

Strength and muscle specificity of a compact promoter derived from the slow troponin I gene in the context of episomal (gutless adenovirus) and integrating (lentiviral) vectors

“…Because of their large transport capacity of 35 kb, HDAd can carry two copies of the full-length dystrophin cDNA or its paralog utrophin. It has been demonstrated that HDAd-mediated gene transfer in the mouse model of DMD (mdx mice) can produce sufficient dystrophin or utrophin to mitigate the pathology caused by the absence of dystrophin [14][15][16][17][18][19][20].…”

Helper Dependent Adenovirus Vectors: Progress and Future Prospects

“…Thus, laparotomy administration of HDAd encoding dystrophin in the diaphragm of mdx mice resulted in functional amelioration for at least 30 days [81]. Similarly, intraperitoneal injection of the vector in double knock-out mice for dystrophin and utrophin showed efficient transduction of the diaphragm, dystrophin expression for at least 9 weeks, and rescue from ventilatory impairment [82]. Of note, recent advances in vector development have shown that, in adult mice, intramuscular administration of chimeric HDAd5/3 vectors transduced the skeletal muscle significantly better than HDAd serotype 5, and long-term gene expression was observed for at least 1 year, suggesting the feasibility of these vectors for muscledirected gene therapy [83].…”