Decrease of mitochondrial protein levels in human OPMD muscle biopsies.

<p>A) Distribution of differentially expressed proteins from OPMD and control human muscle samples, following a quantitative label-free LC-MS profiling proteomic analysis. Proteins are sorted according to their GO terms in "cellular component" using DAVID. Each square represents a protein. The value of the fold change is color-coded. Yellow to red, over-expressed in OPMD samples (maximum 20-fold); blue, under-expressed in OPMD samples (minimum -20-fold). B) Number of subunits of the mitochondrial respiratory chain complexes down-regulated in OPMD patient muscle biopsies. C) Quantification of levels of mRNAs encoding mitochondrial respiratory chain subunits in control and OPMD patient muscle biopsies, using RT-qPCR. Normalization was with B2M (Beta-2 microglobulin) mRNA. Box plots are from 4–7 muscle biopsies, the median is indicated as an horizontal line within the box. * <i>p</i>-value <0.05 using the Student’s t-Test. For ATP5B and ATP5F1, the median is lower in OPMD than in control biopsies, although the difference is not recorded as significant. D) Quantification of mitochondrial DNA on muscle biopsies, using qPCR. The MT-RNR1 mitochondrial gene was quantified. Normalization was with B2M nuclear DNA. Means are from four biological replicates, error bars represent standard deviation. ns: not significant, using the Student’s t-Test.