Immunohistochemical Study of Expression of Involucrin, Loricrin, Filaggrin and Bcl-2 in Psoriasis

Kim, Kyung Dal; Kim, Hyun Jin; Kim, Nack In

Abstract

BACKGROUND: The pathogenesis of psoriasis remains uncertain. It is known that a variety of factors take a role in its pathogenesis. One of them is the alteration of keratinocytes differentiation. The terminal differentiation of keratinocytes includes the process of the synthesis of proteins such as involucrin, filaggrin, loricrin and cornifin, and produce keratohyaline granules and a structure termed cornified cell envelope finally. And the terminal differentiation of keratinocytes is known as a process of apoptosis, programmed cell death.
OBJECTIVE
In this study, we tried to clarify the pathogenetic mechanisms of psoriasis by comparing the expression patterns of several proteins(involucrin, loricrin, filaggrin) associated with keratinocyte differentiation and of bcl-2 protein, known as inhibitor of apoptosis, between lesional and non-lesional psoriatic skin.
RESULTS
The results were summarized as follows, firstly early expression of involucrin in lower epidermis, secondly no or reduced expression of filaggrin and loricrin in upper epidermis and lastly no expression of bcl-2 in basal layer of psoriatic skin.
CONCLUSION
This study clarified that the accelerated terminal differentiation, the shortening of cell-cycle of keratinocytes, and the increased turnover of keratinocytes may be involved in the pathogenetic role of psoriasis.