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Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - The Amyloid Precursor Protein Plays Differential Roles in the UVA Resistance and Proliferation of Human Retinal Pigment Epithelial Cells
AU - Sultan, Fatima
AU - Parkin, Edward
N1 - The published manuscript is available at EurekaSelect via http://www.eurekaselect.com/10.2174/0929866529666220217124152
PY - 2022/3/30
Y1 - 2022/3/30
N2 - Background: Age-related macular degeneration (AMD) can be characterised by degeneration of retinal pigment epithelial (RPE) cells and the accumulation, in retinal drusen deposits, of amyloid beta-peptides proteolytically derived, by secretases, from the amyloid precursor protein (APP). Ultraviolet (UV) light exposure is a risk factor for the development of AMD. Objectives: In the current study, we investigated whether APP and/or its proteolysis are linked to the UVA resistance or proliferation of ARPE-19 human RPE cells. Methods: Cell viability was determined, following UVA exposure, with prior small interfering RNA-mediated APP depletion or secretase inhibitor treatments. APP levels/proteolysis were analysed by immunoblotting. Cells were also grown in the presence/absence of secretase inhibitors to assess their effects on longer-term culture growth. Finally, the effects of APP proteolytic fragments on ARPE-19 cell proliferation were monitored following co-culture with human embryonic kidney cells stably over-expressing these fragments. Results: Endogenous APP was depleted following UVA irradiation and β-secretase, but not -secretase, processing of the protein was reduced. Experimental APP depletion or -secretase (but not - or β-secretase) inhibition ablated the detrimental effect of UVA on cell viability. In contrast, -secretase, and possibly -secretase but not β-secretase activity, appeared to promote the longer-term proliferation of ARPE-19 cells in the absence of UVA irradiation Conclusions: There are clear but differential links between APP expression/proteolysis and the proliferation and UVA resistance of ARPE-19 cells indicating that the protein should be investigated further in relation to the identification of possible drug targets for the treatment of AMD.
AB - Background: Age-related macular degeneration (AMD) can be characterised by degeneration of retinal pigment epithelial (RPE) cells and the accumulation, in retinal drusen deposits, of amyloid beta-peptides proteolytically derived, by secretases, from the amyloid precursor protein (APP). Ultraviolet (UV) light exposure is a risk factor for the development of AMD. Objectives: In the current study, we investigated whether APP and/or its proteolysis are linked to the UVA resistance or proliferation of ARPE-19 human RPE cells. Methods: Cell viability was determined, following UVA exposure, with prior small interfering RNA-mediated APP depletion or secretase inhibitor treatments. APP levels/proteolysis were analysed by immunoblotting. Cells were also grown in the presence/absence of secretase inhibitors to assess their effects on longer-term culture growth. Finally, the effects of APP proteolytic fragments on ARPE-19 cell proliferation were monitored following co-culture with human embryonic kidney cells stably over-expressing these fragments. Results: Endogenous APP was depleted following UVA irradiation and β-secretase, but not -secretase, processing of the protein was reduced. Experimental APP depletion or -secretase (but not - or β-secretase) inhibition ablated the detrimental effect of UVA on cell viability. In contrast, -secretase, and possibly -secretase but not β-secretase activity, appeared to promote the longer-term proliferation of ARPE-19 cells in the absence of UVA irradiation Conclusions: There are clear but differential links between APP expression/proteolysis and the proliferation and UVA resistance of ARPE-19 cells indicating that the protein should be investigated further in relation to the identification of possible drug targets for the treatment of AMD.
KW - Amyloid precursor protein
KW - ultraviolet
KW - resistance
KW - proliferation
KW - retinal
KW - pigment
KW - epithelial
U2 - 10.2174/0929866529666220217124152
DO - 10.2174/0929866529666220217124152
M3 - Journal article
VL - 29
SP - 313
EP - 327
JO - Protein and Peptide Letters
JF - Protein and Peptide Letters
SN - 0929-8665
IS - 4
ER -