ApoE in Oral Lichen Planus

Abstract

Oral lichen planus er en vanlig slimhinnelidelse med ukjent etiologi. Omtrent 3% av befolkningen rammes. Hovedvekt av kvinner. Målet med vårt studie var å undersøke om en oppregulering av ApoE i oral lichen planus kunne indusere differensiering av dendrittiske celler og dermed spille en rolle i økningen av regulatoriske T lymfocytter i tilstanden. Metodene vi brukte var microarray, real time pcr, immunohistokjemi og celle dyrking. Resultatet viser at det er klar forskjell mellom uttrykket av ApoE i sykt og friskt vev fra samme pasient. Stimuleringsforsøkene våre med human analog av et tidligere brukt musepeptid, hEp1.B, felte ut. Til tross for dette ble det observert en økning av dendritisk cellemarkør i THP-1 cellelinje. Dette er trolig som følge av en translokering fra intracellulære lagre til cellemembran. Vi konluderte med selv om ApoE er oppregulert og muligens kan spille en rolle i immun regulering ved oral lichen planus, så er det ikke noe bevis for dette på nåværende tidspunkt.

Background: Oral Lichen Planus is a common chronic mucocutaneous disease of unknown etiology. It affects up to 3% of females, is four times less frequent in males and is diagnosed predominantly after the age of 40. Aim: The goal of this study was to investigate whether up regulation of ApoE could induce DC differentiation in OLP and as such play a possible role in the increase of Tregs in oral lichen planus. Method: Gene expression from 2 patients diagnosed with OLP was analyzed using microarray. Selected genes were then analyzed using Rt-PCR to confirm results. Cell lines were grown to see if self peptide Ep1.B derived from ApoE could induce dendritic like morphology. Results: Gene expression between sick and control samples showed that ApoE was up regulated in OLP. We found that the human analogue to the self peptide derived from Ep1.B reported by Singh et al did not to have the ability to differentiate human monocytic cell lines into functional dendritic cells. Cell lines grown with ApoE self-peptide showed increase in DC marker DEC-205. This is however more likely due to translocation from cytoplasma to cell surface. No increase in DEC-205 mRNA was found in PCR analysis. Conclusion: Our study shows that although ApoE may play a role in immunoregulation. There is as of now no evidence to support a conclusion that ApoE play a key role in the complex immunological picture in oral lichen planus.