Lysosomal enzyme and inhibitor levels in the human trabecular meshwork. Invest Ophthalmol Vis Sci 1994 Jan;35(1):251-61
Date
01/01/1994Pubmed ID
8300353Scopus ID
2-s2.0-0028082389 (requires institutional sign-in at Scopus site) 9 CitationsAbstract
PURPOSE: To examine in the human trabecular meshwork lysosomal enzymes and one inhibitor of serine proteases that actively participate in the degradation of macromolecules into low molecular weight constituents.
METHODS: Using an avidin-biotin-peroxidase technique, lysosomal proteases and alpha 1-proteinase inhibitor were examined in the trabecular meshwork of 23 human eyes with donor ages ranging from 2 to 90 years. These eyes were categorized into three age groups (< or = 20, 21 to 49, and > or = 50 years). Histochemical staining for lysosomal hydrolases was also performed on frozen sections of 20 human eyes. The staining was analyzed by an image analyzer and the levels of lysosomal proteases were further measured by biochemical assays.
RESULTS: The trabecular meshwork from all the eyes stained intensely against antibodies to cathepsins B and G and alpha 1-proteinase inhibitor. The staining for elastase was weaker but evident. Image analyses revealed that the staining intensity for each protease or inhibitor was similar in all age groups. The staining in the uveal meshwork appeared to be the strongest among all the trabecular meshwork regions. Biochemical assays of tissue extracts confirmed that the enzyme and inhibitor levels were comparable among the three donor age groups. Activities of two lysosomal hydrolases, acid phosphatase and acid esterase, were also found in trabecular meshwork cells of 20 eyes. No apparent difference in enzyme activities was found with increasing age, and variation related to region was not observed.
CONCLUSIONS: This study demonstrated the age-independent distribution of a variety of lysosomal enzymes and a protease inhibitor in the human trabecular meshwork. The presence of these proteins suggests a possible role in the metabolic operation of the trabecular meshwork.
Author List
Sawaguchi S, Yue BY, Kawa JE, Chang IL, Twining SS, Meberg BAuthor
Sally S. Twining PhD Assistant Dean, Professor in the Biochemistry department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
AdolescentAdult
Aged
Aged, 80 and over
Aging
Child, Preschool
Enzyme-Linked Immunosorbent Assay
Humans
Hydrolases
Image Processing, Computer-Assisted
Immunoenzyme Techniques
Lysosomes
Middle Aged
Trabecular Meshwork
alpha 1-Antitrypsin
