Observation on the expression of P62 protein in common neurodegenerative diseases

Abstract

Objective To evaluate the expression of P62 protein in the characteristic pathological changes of common neurodegenerative diseases and to explore its significance in pathological diagnosis. Methods Eleven cases of neurodegenerative diseases and 3 normal controls which were clinically and pathologically diagnosed from June 1994 to October 2017 were included. The neurodegenerative diseases consisted of 5 cases of Alzheimer's disease (AD) and 2 of which were diagnosed as AD combined with argyrophilic grain disease (AGD), 3 cases of Parkinson's disease (PD), 2 cases of progressive supranuclear palsy (PSP) and 1 case of multiple system atrophy (MSA). Three cases without neurological symptoms, signs and brain pathological changes were used as the normal control. Brain tissues were stained with HE, luxol fast blue (LFB) and Gallyas-Braak silver staining, as well as antibodies to amyloid β-protein (Aβ), AT8, α-synuclein and P62. The staining results were compared under microscope. Results P62 protein was present in the neurofibrillary tangles of AD, in the Lewy body and Lewy neurites of PD, in the tufted astrocyte of PSP, in the argyrophilic grain of AGD and in the glial cytoplasmic inclusion of MSA. The morphological characteristics were consistent with the results of staining with specific antibodies. P62 protein was only expressed in a small amount in the neuritic plaque of AD, and the diffuse plaques were negative. In addition, P62 protein was also deposited in corpora amylacea. No positive pathological structure of P62 immunohistochemical staining was found in normal control brain tissues. Conclusions The P62 protein is expressed in the characteristic pathological changes and corpora amylacea of AD, PD, PSP, MSA and other diseases. Morphological staining results are consistent with histology of various neurodegenerative diseases and corresponding specific protein expression staining results. So the P62 antibody is recommended as the aiding pathological diagnosis of neurodegenerative diseases.

Keywords

• Neurodegenerative diseases; Adaptor proteins
• signal transducing; Autophagy; Immunohistochemistry; Pathology