[Cellular stress response in the eye].

Abstract

The cellular stress response consists of general inhibition of normal protein synthesis and enhancement of a group of stress or heat shock proteins (SPs or HSPs). Current studies show this response system to be present in various cells from bacteria to man. A number of HSPs have been described, and four are now regarded as universal. Three are described in terms of their molecular weights of 90K, 70K and 20--30K daltons, respectively, and a fourth is known as ubiquitin. Most of these have been highly preserved throughout evolution. One important role for HSPs is certainly related to cellular homeostasis including thermotolerance. It is quite possible that cytoskeletal changes occurring during heat shock are involved in the regulation of HSP synthesis and that HSPs themselves have cytoarchitectural roles. In this review, the history of research on heat shock proteins was introduced to elucidate their functions. Cellular stress response in ocular tissues was also taken into account. For example, immunocytochemical investigations have indicated that normally less detectable glial fibrillary acidic protein in Müller cells is expressed in response to neuronal injury, degeneration, retinal detachment and under in vitro conditions. Current studies, including our own, show the accumulation of HSPs or SPs in various retinal cells (e.g. Müller cells, retinal neurons, and retinal pigment epithelia) following either herpes simplex infection or heat shock. The possible clinicopathological significance of the above cellular responses is discussed.