LAMP1 and mitochondrial neurogastrointestinal encephalomyopathy: To further investigate whether autophagosomes were efficiently degraded or whether there was disruption in autophagic flux, the protein expression levels of autophagy markers (including LC3B, SQSTM1 and ubiquitin) and the lysosome marker protein LAMP1 were analyzed by Western blot in muscle samples from MNGIE patients.