Andrographolide attenuates skeletal muscle dystrophy in mdx mice and increases efficiency of cell therapy by reducing fibrosis

Abstract

BackgroundDuchenne muscular dystrophy (DMD) is characterized by the absence of the cytoskeletal protein dystrophin, muscle wasting, increased transforming growth factor type beta (TGF-β) signaling, and fibrosis. At the present time, the only clinically validated treatments for DMD are glucocorticoids. These drugs prolong muscle strength and ambulation of patients for a short term only and have severe adverse effects. Andrographolide, a bicyclic diterpenoid lactone, has traditionally been used for the treatment of colds, fever, laryngitis, and other infections with no or minimal side effects. We determined whether andrographolide treatment of mdx mice, an animal model for DMD, affects muscle damage, physiology, fibrosis, and efficiency of cell therapy.Methodsmdx mice were treated with andrographolide for three months and skeletal muscle histology, creatine kinase activity, and permeability of muscle fibers were evaluated. Fibrosis and TGF-β signaling were evaluated by indirect immunofluorescence and Western blot analyses. Muscle strength was determined in isolated skeletal muscles and by a running test. Efficiency of cell therapy was determined by grafting isolated skeletal muscle satellite cells onto the tibialis anterior of mdx mice.Resultsmdx mice treated with andrographolide exhibited less severe muscular dystrophy than untreated dystrophic mice. They performed better in an exercise endurance test and had improved muscle strength in isolated muscles, reduced skeletal muscle impairment, diminished fibrosis and a significant reduction in TGF-β signaling. Moreover, andrographolide treatment of mdx mice improved grafting efficiency upon intramuscular injection of dystrophin-positive satellite cells.ConclusionsThese results suggest that andrographolide could be used to improve quality of life in individuals with DMD.

Decreased grip strength, muscle pain, and atrophy occur in rats following long‐term exposure to excessive repetitive motion

“…Cabrera et al . showed increased collagen type I in skeletal muscle after repetitive reaching and grasping tasks, and attributed muscle fibrosis to the muscle weakness. In our study, the grip strength of rats in the Task group was lowest at 6 weeks.…”

Angiotensin (1-7) Decreases Myostatin-Induced NF-κB Signaling and Skeletal Muscle Atrophy

“…The relevance of the anti-atrophic effect of Ang-(1-7) and especially the depletion of NF-κB signaling has been discussed. Moreover, in some muscle disorders, the NF-κB inhibition has been demonstrated to improve muscle function and mass [53][54][55].…”

“…The skeletal muscle cell line C 2 C 12 (American Type Culture Collection, NY, USA) was grown in Dulbecco's modified eagle's medium (DMEM) supplemented with 10% fetal serum bovine (FSB) and used for 10 passages. The cells were differentiated until day 5 by changing DMEM-FSB to DMEM supplemented with horse serum, as previously described [55][56][57][58]. The myotubes were incubated with 1 µg/ml of human recombinant myostatin (Cell Sciences Inc., MA, USA) and/or 10 nM of Ang-(1-7) (Sigma-Aldrich, USA), as indicated in each figure.…”

The complex of PAMAM-OH dendrimer with Angiotensin (1–7) prevented the disuse-induced skeletal muscle atrophy in mice

“…Muscle strength was determined as described previously. [31][32][33] Briefly, the optimum muscle length (Lo) and stimulation voltage were determined from micromanipulations of muscle length to produce the maximum isometric twitch force using a S48 rNa isolation, reverse transcription, and quantitative real-time polymerase chain reaction (Pcr)…”