Localization of cathepsin D in rat ocular tissues. An immunohistochemical study

https://doi.org/10.1016/S0940-9602(11)80123-8Get rights and content

Summary

Numerous studies have demonstrated that cathepsin D as a major lysosomal acid protease plays an important role in the degradation of protein in several tissues. An important function of the retinal pigment epithelium is to interact with the photoreceptor cells in the renewal process. During the renewal process, the RPE cell phagocytoses discarded photoreceptor discs which are then degraded in the RPE phagolysosomes. It is believed that cathepsin D plays a main role in the degradation of rod outer segments and rhodopsin into glycopeptides. The cellular localization of cathepsin D immunoreactivity was examined at the light microscopic level in the ocular tissues of non-affected RCS-rdy+ rat strain by use of the alkaline phosphatase-antialka-line phosphatase (APAAP) technique. The presence of cathepsin D immunoreactivity was found in the cell cytoplasm of the following ocular tissues: retinal pigment epithelium; Müller cells; ganglion cells; pigmented and non-pigmented ciliary body; iris tissue; epithelium and endothelium of the cornea; endothelium of various vessels, including the tunica vasculosa lends. High activity of cathepsin D was found in the RPE cells, as well as in the cytoplasm of Müller cells, especially expressed in their foot plates lying close to the inner limiting membrane.

Literature (34)

  • T Shiono et al.

    Effect of temperature and pH on release of enzymes from lysosomes of the bovine retinal pigment epithelium in vitro

    Exp Eye Res

    (1983)
  • JN Whitaker et al.

    Immunocytochemical localization of cathepsin D in rat neural tissue

    Brain Res

    (1981)
  • BYJT Yue et al.

    Lysosomal enzyme activities in cultured trabecular-meshwork cells

    Exp Eye Res

    (1987)
  • AJ Adler et al.

    Lysosomal enzymes in the interphotoreceptor matrix: acid protease

    Curr Eye Res

    (1983)
  • J Cejkova et al.

    Alkali burns of the rabbit cornea I. A histochemical study of beta-glucuronidase, beta-galactosidase and N-acetyl-beta-D-glucosaminidase

    Histochemistry

    (1975)
  • E El-Hifnawi et al.

    The role of lysosomes in hereditary retinal dystrophy in RCS rats

  • E El-Hifnawi et al.

    Über die mögliche Wirkung von Aspirin auf den Degenerationsprozeß der Retina bei RCS-Ratten

    Klin Mbl Augenheilk

    (1989)
  • Cited by (19)

    • Cellular and molecular mechanisms of age-related macular degeneration: From impaired autophagy to neovascularization

      2013, International Journal of Biochemistry and Cell Biology
      Citation Excerpt :

      In the RPE cells, cathepsins A, D, E and S have been characterized (Im and Kazlauskas, 2007). Cathepsin D plays an important role in the degradation of rod outer segments and rhodopsin into glycopeptides. (el-Hifnawi, 1995). Interestingly, cathepsin D-deficient mice have been shown to develop postnatal retinal atrophy and suffer an increased incidence of apoptosis in the outer and inner nuclear layers (Koike et al., 2003).

    • The role of cathepsins in ocular physiology and pathology

      2007, Experimental Eye Research
      Citation Excerpt :

      Although the potential to use cathepsin inhibitors to prevent and/or manage ocular diseases is as yet unexplored, promising results from numerous clinical studies in other diseases suggest that targeting cathepsin activity will be a useful approach to prevent and/or cure ocular diseases. Cathepsin D found in the lysosome of retinal pigment epithelium cell plays a main role in degradation of the phagocytosed photoreceptor during their renewal process (el-Hifnawi, 1995). Cathepsin D degrades rod outer segments and rhodopsin into glycopeptides.

    View all citing articles on Scopus
    *

    Supported by DFG Grant Hi 434/3-2

    View full text