Lysosomal alterations in peripheral blood mononuclear cells of Parkinson's disease patients

Reduced expression of lysosomal-associated membrane protein 2a and heatshock-cognate 70 proteins, involved in chaperone-mediated autophagy and of glucocerebrosidase, is reported in PD brains. The aim of this study was to identify systemic alterations in lysosomal-associated membrane protein 2a, heatshock cognate-70, and glucocerebrosidase levels/activity in peripheral blood mononuclear cells from PD patients.

Protein/mRNA levels were assessed in PD patients from genetically undetermined background, alpha-synuclein (G209A/A53T), or glucocerebrosidase mutation carriers and age-/sex-matched controls.

Heatshock cognate 70 protein levels were reduced in all PD groups, whereas its mRNA levels were decreased only in the genetically undetermined group. Glucocerebrosidase protein levels were decreased only in the genetic PD groups, whereas increased mRNA levels and decreased activity were detected only in the glucocerebrosidase mutation group.

Reduced heatshock cognate-70 levels are suggestive of an apparent systemic chaperone-mediated autophagy dysfunction irrespective of genetic background. Glucocerebrosidase activity may serve as a screening tool to identify glucocerebrosidase mutation carriers with PD.