Immunocytochemical localization of cathepsin D in the rat osteoclast

Abstract

We performed immunocytochemical localization of cathepsin D in osteoclasts of the proximal growth plate of the rat femurs using both the avidin-biotin-peroxidase complex method for cryo-semi-thin (1 micron) sections and the colloidal gold-labeled IgG method for K4M ultra-thin sections. At the light microscopic level, cathepsin D immunoreactivity in the osteoclasts appeared at the vesicles, granules, and/or small vacuoles. They were distributed throughout the cytoplasm of each cell and were relatively numerous close to the bone surface. This antigen could not be detected at the eroded bone surface. As for other cells, immunoreactivity was seen only in the lysosomes of osteoblast-like cells. Immunoreactivity in the osteoclasts was stronger and greater in the density and number than in osteoblast-like cells. At the electron microscopic level, osteoclasts with well-developed ruffled border possessed numerous cathepsin D-containing lysosomes, vacuoles, and coated vesicle-like structures. Cathepsin D-containing lysosomes fused with cathepsin-negative vacuoles and formed large secondary lysosomes. Osteoclasts with poorly developed ruffled border possessed fewer cathepsin D-containing lysosomes than those with well-developed ruffled border. No immunogold particles were seen in vacuole-like channel expansions of the ruffled borders, between the channels of the ruffled borders, or on the eroded bone surface. These findings demonstrate that osteoclasts contain a large amount of cathepsin D. They suggest that cathepsin D is necessary for osteoclastic bone resorption, that it plays an indirect rather than direct role.

The expression of cathepsin-D in odontogenic cysts and tumors: Immunohistochemistry study

“…Cathepsin-D is necessary for osteoclastic bone resorption, and it plays an indirect rather than a direct role. [16] A large amount of cathepsin-D in osteoclast at the proximal growth plate of the rat femurs was demonstrated using both the avidinbiotin-peroxidase complex method for cryo-semi-thin sections and the colloidal gold-labeled IgG method for K4M ultrathin sections indicating the role of cathepsin-D in osteoclastmediated bone resorption. [16] To the best of our knowledge, this is the first study on the expression of cathepsin-D in odontogenic cysts and tumors although studies on various other lysosomal enzymes like leucine amino peptidase, etc., have been published.…”

“…[16] A large amount of cathepsin-D in osteoclast at the proximal growth plate of the rat femurs was demonstrated using both the avidinbiotin-peroxidase complex method for cryo-semi-thin sections and the colloidal gold-labeled IgG method for K4M ultrathin sections indicating the role of cathepsin-D in osteoclastmediated bone resorption. [16] To the best of our knowledge, this is the first study on the expression of cathepsin-D in odontogenic cysts and tumors although studies on various other lysosomal enzymes like leucine amino peptidase, etc., have been published. [9] Hence, it may be presumptuous on our part to make claims on the role of cathepsin-D in aggressive behavior of odontogenic cysts and tumors, however that there is perceptible variation in expression would suggest that additional efforts in the area may help to understand the metabolic processes that lead to aggressive behavior.…”

Lysosomal cysteine and aspartic proteinases, acid phosphatase, and an endogenous cysteine proteinase inhibitor, cystatin-beta, in rat osteoclasts.

“…Cathepsin L has been believed to be one of the most potent enzymes, which has collagenolytic activity in the acidic mileu (Kirschke et al, 1982), while cathepsin B is able to depolymerize collagen (DelaissE et al, 1991). Until recently, however, no immunohistochemical localization of these proteinases has been shown in bone tissue, except for cathepsin D in osteoclasts (Goto et al, 1992) and cathepsin C in the resorption lacunae (Baron et al, 1988). Therefore, to further understand the mechanism that mediates bone resorption by osteoclasts, it is essential to examine the presence of lysosomal cysteine proteinases in the cells.…”

High levels of substance P and CGRP in pseudosynovial fluid from patients with aseptic loosening of their hip prosthesis

“…Fibroblasts, lymphocytes, and macrophages are equipped with SP receptors and SP has been shown to induce the release of IL-1, IL-6, and TNF from these cells (Yamaguchi et al 2004). SP receptors have also been found on the plasma membrane and in the cytoplasm of osteoclasts (Goto et al 1992). In an experiment using mouse calvaria, SP caused increased bone resorption (Sherman et al 1995).…”