The effects of the antifibrotic drug Halofuginone hydrobromide (Halo) on muscle function, regeneration and cardiorespiratory function were studied using mdx mice. It was hypothesized that Halo treatment would resolve pre-established fibrosis and prevent collagen deposits, improving muscle and cardio-respiratory function. Mice 8-9 mos were treated with saline or Halo for 5 (n = 4/group), 10 (n = 5/group) and 12 weeks (n = 4-5/group). Muscle strength and endurance, respiration and muscle susceptibility to damage were assessed. Tissues were collected from all mice. Additional mice were treated for 10 wks (3-4 wks n = 9-10/group; 8-9 mos n = 8-9/group) for echocardiography. Halo reduced fibrosis. As a consequence, there was muscle repair and damage was reduced. There were functional improvements and disease progression was slowed. There was resolution of pre-existing fibrosis and reduction of new collagen synthesis. This treatment could improve quality of life and lengthen the lifespan of DMD patients. / May 2007

Compensatory hypertrophy was induced on the plantaris (PL) and soleus (SOL) muscles of five week old normal and dystrophic (strain 14.6) hamsters. This was done to indicate whether submaximal exercise would be beneficial in reducing the progression of the muscular dystrophy (i.e., by causing muscle hypertrophy, reducing the total collagen content, and increasing the total protein content of the diseased muscle to approximate that of normal tissue).The hamsters were divided into four groups: 1) dystrophic overload (DO), 2) dystrophic control (DC), 3) normal overload (NO), and 4) normal control (NC). Eight weeks of overload of the PL and SOL muscles was induced by surgical ablation of the synergistic gastrocnemius muscle. Muscle wet weight data indicated significant muscle hypertrophy of 125% and 92% in the NO and DO PL respectively, and 60% in the NO SOL. Dry muscle weight data was comparable to the above results. There was no significant difference in the muscle collagen content between the NC and DC groups. Collagen content increased significantly in the NO and DO PL by 81% and 41% respectively, and in the NO and DO SOL by 127% and 57% respectively. The DC muscle was significantly lower in protein content than the NC muscle (180.2mg/g and 210.1 mg/g respectively) when expressed per g of wet muscle weight. This significance disappears when expressed per g dry muscle weight. The overload caused a significant decrease in the protein content of only the NO group when expressed by both wet and dry tissue weights (171.7mg/g and 678.3mg/g rrespectively). The hydration of the DC group was significantly higher than the NC group. The overload resulted in a significant increase in the water content of only the NO muscle.The results of this study indicate that dystrophic muscle will hypertrophy as indicated by muscle weight data. However, the significance of the data from the total collagen and total protein determination of the overload groups was inconclusive due to the formation of scar tissue. This scar tissue resulted in high collagen content. The high glycine content in this collagen in turn resulted in low protein values.

The effects of the antifibrotic drug Halofuginone hydrobromide (Halo) on muscle function, regeneration and cardiorespiratory function were studied using mdx mice. It was hypothesized that Halo treatment would resolve pre-established fibrosis and prevent collagen deposits, improving muscle and cardio-respiratory function. Mice 8-9 mos were treated with saline or Halo for 5 (n = 4/group), 10 (n = 5/group) and 12 weeks (n = 4-5/group). Muscle strength and endurance, respiration and muscle susceptibility to damage were assessed. Tissues were collected from all mice. Additional mice were treated for 10 wks (3-4 wks n = 9-10/group; 8-9 mos n = 8-9/group) for echocardiography. Halo reduced fibrosis. As a consequence, there was muscle repair and damage was reduced. There were functional improvements and disease progression was slowed. There was resolution of pre-existing fibrosis and reduction of new collagen synthesis. This treatment could improve quality of life and lengthen the lifespan of DMD patients.

The effects of the antifibrotic drug Halofuginone hydrobromide (Halo) on muscle function, regeneration and cardiorespiratory function were studied using mdx mice. It was hypothesized that Halo treatment would resolve pre-established fibrosis and prevent collagen deposits, improving muscle and cardio-respiratory function. Mice 8-9 mos were treated with saline or Halo for 5 (n = 4/group), 10 (n = 5/group) and 12 weeks (n = 4-5/group). Muscle strength and endurance, respiration and muscle susceptibility to damage were assessed. Tissues were collected from all mice. Additional mice were treated for 10 wks (3-4 wks n = 9-10/group; 8-9 mos n = 8-9/group) for echocardiography. Halo reduced fibrosis. As a consequence, there was muscle repair and damage was reduced. There were functional improvements and disease progression was slowed. There was resolution of pre-existing fibrosis and reduction of new collagen synthesis. This treatment could improve quality of life and lengthen the lifespan of DMD patients.

Thesis--University of Wisconsin--Madison. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 149-160).

No description available.

Abstract available in PDF document. / Thesis (Ph.D.)-University of KwaZulu-Natal, Durban, 2008.

Meesmann's epithelial corneal dystrophy (MEeD), which clinically presents with microcysts that can cause irritation, blurred vision or photophobia, is a genetic disorder caused by dominant-negative mutations in the KRT3 and KRT12 genes. Eradicating the mutant protein or tipping the balance strongly in favour of the wild type allele are viable options for therapeutic intervention. Here we studied two therapeutic approaches for suppression of the mutant KRTl2 allele and have developed, characterised and initiated in vivo testing using two novel KRTl2 mouse models. For a transient therapeutic approach, short interfering RNAs (siRNAs) were designed and proved capable of mutation-specific inhibition of the alleles responsible for two MEeD causative mutations (p.Leu132Pro and p.Arg135Thr; 70-90%) in vitro. No off-target issues were observed and suppression of endogenously expressed p.Leu132Pro was also shown in an ex vivo model. For a more generic, yet potentially permanent therapeutic approach, total KRTl2 was suppressed (~50%) with an siRNA expressed from a short hairpin by targeting a region homologus to both the WT and mutant mRNAs. KRT 12 was replaced with a co-expressed recoded allele made resistant to the siRNA. To further develop these potential therapeutics, two novel mouse models were generated allowing evaluation of gene modulation in vivo. (1) A humanised dominant negative mutant model that expresses K12 p.Leu132Pro revealed major changes to corneal phenotype in homozygous animals. Microcysts were observed and keratin expression patterns disrupted. Additionally, RNAseq analysis highlighted over 1600 dysregulated genes, which could feature other potential therapeutic targets for the treatment of symptomatic MEeD. Heterozygous mice presented with a subtler phenotype. (2) A Krt12 luciferase reporter mouse model was optimised and will facilitate live animal corneal imaging, thus aiding the development of topical siRNA delivery formulations. These mouse models in conjunction with our gene silencing development programme pave the way for in vivo assessment of RNA i-based therapeutics for the cornea.

No description available.

No description available.