title: Daily supplementation of D-ribose shows no therapeutic benefits in the MHC-I transgenic mouse model of inflammatory myositis.
abstract: BACKGROUND
  Current treatments for idiopathic inflammatory myopathies (collectively called myositis) focus on the suppression of an autoimmune inflammatory response within the skeletal muscle. However, it has been observed that there is a poor correlation between the successful suppression of muscle inflammation and an improvement in muscle function. Some evidence in the literature suggests that metabolic abnormalities in the skeletal muscle underlie the weakness that continues despite successful immunosuppression. We have previously shown that decreased expression of a purine nucleotide cycle enzyme, adenosine monophosphate deaminase (AMPD1), leads to muscle weakness in a mouse model of myositis and may provide a mechanistic basis for muscle weakness. One of the downstream metabolites of this pathway, D-ribose, has been reported to alleviate symptoms of myalgia in patients with a congenital loss of AMPD1. Therefore, we hypothesized that supplementing exogenous D-ribose would improve muscle function in the mouse model of myositis. We treated normal and myositis mice with daily doses of D-ribose (4 mg/kg) over a 6-week time period and assessed its effects using a battery of behavioral, functional, histological and molecular measures.
  
  
  RESULTS
  Treatment with D-ribose was found to have no statistically significant effects on body weight, grip strength, open field behavioral activity, maximal and specific forces of EDL, soleus muscles, or histological features. Histological and gene expression analysis indicated that muscle tissues remained inflamed despite treatment. Gene expression analysis also suggested that low levels of the ribokinase enzyme in the skeletal muscle might prevent skeletal muscle tissue from effectively utilizing D-ribose.
  
  
  CONCLUSIONS
  Treatment with daily oral doses of D-ribose showed no significant effect on either disease progression or muscle function in the mouse model of myositis.
authors.affiliation: Research Center for Genetic Medicine, Children's National Medical Center, Washington, DC, United States of America.
authors.forename: William
authors.initials: W
authors.lastname: Coley
authors.forename: Sree
authors.initials: S
authors.lastname: Rayavarapu
authors.forename: Jack H
authors.initials: JH
authors.lastname: van der Meulen
authors.forename: Ayyappa S
authors.initials: AS
authors.lastname: Duba
authors.forename: Kanneboyina
authors.initials: K
authors.lastname: Nagaraju
mesh_terms: D000659:AMP Deaminase / Q000378:metabolism; D000249:Adenosine Monophosphate / Q000378:metabolism; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D001835:Body Weight / Q000187:drug effects; D019587:Dietary Supplements; D004195:Disease Models, Animal; D005260:Female; D015395:Histocompatibility Antigens Class I / Q000235:genetics*; D008297:Male; D053858:Metabolic Networks and Pathways; D051379:Mice; D008822:Mice, Transgenic; D009119:Muscle Contraction / Q000187:drug effects; D018482:Muscle, Skeletal / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D009220:Myositis / Q000188:drug therapy / Q000235:genetics*; D012266:Ribose / Q000008:administration & dosage / Q000378:metabolism / Q000494:pharmacology*
chemical_list: D015395:Histocompatibility Antigens Class I; D000249:Adenosine Monophosphate; D012266:Ribose; D000659:AMP Deaminase; C577245:AMPD1 protein, mouse