Comparison of BiP and HSP70i as markers of unfolded protein response (UPR) in segmental and nonsegmental vitiligo

Abstract

Background: Unfolded protein response (UPR) is a misfolded protein that occurs because oxidative stress disrupts cellular redox potential that extends to the endoplasmic reticulum (ER). Binding immunoglobulin protein (BiP) and inducible heat shock protein (HSP70i) as ER chaperons play critical roles in melanocyte apoptosis. Our study aims to compare BiP and HSP70i as markers of UPR in patients with segmental vitiligo (SV) and non-segmental vitiligo (NSV). Methods: The subjects were composed of 64 patients diagnosed with vitiligo, of whom 33 had NSV and 31 had SV. Skin biopsy and immunofluorescence were performed. We used BiP and HSP70i as markers of UPR. Descriptive statistics were used to analyze the data. Results: UPR-BiP expression and UPR-HSP70i in the SV group was 2.66 ± 3.07 and 3.85 ± 4.92, respectively, with a p-value of 0.001 (<α = 0.05). In the NSV group UPR-BiP expression and UPR-HSP70i was 12.55 ± 11.85 and 14.79 ± 14.72 respectively, with a p-value of 0.001 (<α = 0.05). UPR expression using the HSP70i marker in both NSV and SV groups was higher than it was using the BiP marker. The relationship between UPR-HSP70i expression and UPR-BiP expression in the SV and NSV group was significant (p <0.05) and positive. Conclusions: HSP70i is superior to BiP as a marker for expressing UPR.