Lack of robust satellite cell activation and muscle regeneration during the progression of Pompe disease

Abstract

IntroductionMuscle stem cells termed satellite cells are essential for muscle regeneration. A central question in many neuromuscular disorders is why satellite cells are unable to prevent progressive muscle wasting. We have analyzed muscle fiber pathology and the satellite cell response in Pompe disease, a metabolic myopathy caused by acid alpha-glucosidase deficiency and lysosomal glycogen accumulation. Pathology included muscle fiber vacuolization, loss of cross striation, and immune cell infiltration.ResultsThe total number of Pax7-positive satellite cells in muscle biopsies from infantile, childhood onset and adult patients (with different ages and disease severities) were indistinguishable from controls, indicating that the satellite cell pool is not exhausted in Pompe disease. Pax7/Ki67 double stainings showed low levels of satellite cell proliferation similar to controls, while MyoD and Myogenin stainings showed undetectable satellite cell differentiation. Muscle regenerative activity monitored with expression of embryonic Myosin Heavy Chain was weak in the rapidly progressing classic infantile form and undetectable in the more slowly progressive childhood and adult onset disease including in severely affected patients.ConclusionsThese results imply that ongoing muscle wasting in Pompe disease may be explained by insufficient satellite cell activation and muscle regeneration. The preservation of the satellite cell pool may offer a venue for the development of novel treatment strategies directed towards the activation of endogenous satellite cells.Electronic supplementary materialThe online version of this article (doi:10.1186/s40478-015-0243-x) contains supplementary material, which is available to authorized users.

Novel GAA Variants and Mosaicism in Pompe Disease Identified by Extended Analyses of Patients with an Incomplete DNA Diagnosis

“…In addition, periodic acid-Schiff (PAS) staining showed minor glycogen accumulation ( Figure S3). These findings suggested that the patient might have late-onset Pompe disease, 24 but there were two inconsistencies: the lack of GAA deficiency in lymphocytes and the LVH, a characteristic of the classic infantile phenotype but not late-onset Pompe disease.…”

“…39 PAS staining was performed on sections of glycolmethacrylate (GMA)-processed tissue. 24 Hematoxylin and eosin (H&E) stainings were performed on both GMA fixated and cryosections. A Hamamatsu NanoZoomer 2.0 (Hamamatsu Photonics) was used for imaging, and images were analyzed with NDP.view software.…”

Modulation of HOXA9 after skeletal muscle denervation and reinnervation

“…In this model, overexpression and knockdown of HOXA9 were mediated through plasmids and detected 36h after transfected, showing a satisfactory overexpression average 4.16-fold at protein levels and 2750.83-fold at mRNA levels, and knockdown to 42.69% at protein levels and 48.75% at mRNA levels ( figure 3.B-E). [19,20], showed inhibited averagely to 38.29% (Myod) and 79.97% (Myogenin) by pIRES2-DsRed2-HOXA9 plasmids, while pPLK/GFP-Puro-HOXA9 shRNA plasmids could rescue them to 116.10% (Myod) and 137.24% (Myogenin) ( figure 4. A-C).…”

A Newly Built rAAV-SaCas9 Genome Editing System Enables Muscle-Directed Gene Editing to Improve Muscular Atrophy

“…All data were obtained and analyzed with Image Pro Plus 6.0 software. For immunostaining, the para n sections of muscle tissue were dewaxed as previously described [34], placed in a solution of sodium citrate at 100 °C for 10 minutes and then soaked in hydrogen peroxide. Cross-section samples were immunostained with mouse monoclonal anti-SaCas9 primary antibody (1:200, Epigentek, catalogue number: A-9001) and goat anti-mouse IgG-FITC (1:500, Abcam, catalogue number: ab6785) secondary antibody, and DAPI for nuclei.…”