Abstract
The impairment of autophagic and proteasomal cleansing together with changes in pigmentation has been documented in retinal pigment epithelial (RPE) cell degeneration. However, the function and co-operation of these mechanisms in melanosome-containing RPE cells is still unclear. We show that inhibition of proteasomal degradation with MG-132 or autophagy with bafilomycin A1 increased the accumulation of premelanosomes and autophagic structures in human embryonic stem cell (hESC)-derived RPE cells. Consequently, upregulation of the autophagy marker p62 (also known as sequestosome-1, SQSTM1) was confirmed in Western blot and perinuclear staining. Interestingly, cells treated with the adenosine monophosphatedependent protein kinase activator, AICAR (5-Aminoimidazole-4-carboxamide ribonucleotide), decreased the proteasome inhibitor-induced accumulation of premelanosomes, increased the amount of autophagosomes and eradicated the protein expression of p62 and LC3 (microtubule-associated protein 1A/1B-light chain 3). These results revealed that autophagic machinery is functional in hESC-RPE cells and may regulate cellular pigmentation with proteasomes.
Original language | English (US) |
---|---|
Article number | 1089 |
Journal | International journal of molecular sciences |
Volume | 18 |
Issue number | 5 |
DOIs | |
State | Published - May 19 2017 |
Keywords
- Autophagy
- Macula
- Melanosome
- Proteasome
- Stem cell
ASJC Scopus subject areas
- Catalysis
- Molecular Biology
- Spectroscopy
- Computer Science Applications
- Physical and Theoretical Chemistry
- Organic Chemistry
- Inorganic Chemistry