Analysis of the proteins of calf and cow trabecular meshwork: development of a model system to study aging effects and glaucoma

The proteins from the trabecular meshwork (TM) of calf and cow eyes were analysed to determine if differences in composition were present and to examine whether this tissue could be used as a framework for the study of glaucoma. Differences in polypeptide composition or amount of protein could be detected with extractions using either acetic acid, neutral buffers and urea, or guanidine hydrochloride. In general, the results suggest that an aggregation of proteins may be occurring with aging. The acid-soluble fraction of both calf and cow TM resembled older human TM specimens with the most prominent protein around 68 kD. To test the utility of the bovine TM system, a mixed function oxidation system was used to determine how the proteins of the TM would react to oxidative stress. Aggregation of the proteins in calf TM as well as actin could be demonstrated, consistent with the idea that the aggregation seen in the cow TM might be the result of oxidation of this tissue. The present study lays a foundation for future work on bovine TM and is consistent with the hypothesis that aging changes in this tissue might be a result of oxidative processes.