Lens proteome map and -crystallin profile of the catfish Rita rita.

Crystallins are a diverse group of proteins that constitute nearly 90% of the total soluble proteins of the vertebrate eye lens and these tightly packed crystallins are responsible for transparency of the lens. These proteins have been studied in different model and non-model species for understanding the modifications they undergo with ageing that lead to cataract, a disease of protein aggregation. In the present investigation, we studied the lens crystallin profile of the tropical freshwater catfish Rita rita. Profiles of lens crystallins were analyzed and crystallin proteome maps of Rita rita were generated for the first time. A-crystallins, member of the -crystallin family, which are molecular chaperons and play crucial role in maintaining lens transparency were identified by 1-and 2-D immunoblot analysis with anti-A-crystallin antibody. Two protein bands of 19-20 kDa were identified as A-crystallins on 1-D immunoblots and these bands separated into 10 discrete spots on 2-D immunoblot. However, anti-B-crystallin and antiphospho-B-crystallin antibodies were not able to detect any immunoreactive bands on 1- and 2-D immunoblots, indicating B-crystallin was either absent or present in extremely low concentration in Rita rita lens. Thus, Rita rita -crystallins are more like that of the catfish Clarias batrachus and the mammal kangaroo in its A- and B-crystallin content (contain low amount from 5-9% of aB-crystallin) and unlike the dogfish, zebrafish, human, bovine and mouse -crystallins (contain higher amount of B-crystallin from 25% in mouse and bovine to 85% in dogfish). Results of the present study can be the baseline information for stimulating further investigation on Rita rita lens crystallins for comparative lens proteomics. Comparing and contrasting the -crystallins of the dogfish and Rita rita may provide valuable information on the functional attributes of A- and B-isoforms, as they are at the two extremes in terms of A-and B-crystallin content.

A Case of Crystalline Keratopathy in Monoclonal Gammopathy of Undetermined Significance (MGUS)

A 62-year-old female visited our clinic with progressively decreased vision in both eyes beginning 12 years prior. Idiopathic corneal opacity in all layers of the cornea was found in both eyes. One year later, we performed penetrating keratoplasty on the undiagnosed right eye. During post-surgical follow-up, corneal edema and stromal opacity recurred, and penetrating keratoplasty was performed two more times. The patient's total serum protein level, which had previously been normal, was elevated prior to the final surgery. She was diagnosed with monoclonal gammopathy of undetermined significance. We made a final diagnosis of monoclonal gammopathy-associated crystalline keratopathy after corneal biopsy. Monoclonal gammopathy-associated crystalline keratopathy is difficult to diagnose and may lead to severe visual loss. A systemic work-up, including serologic tests like serum protein or cholesterol levels, is needed in patients with unexplainable corneal opacity.

Studies on protein and taurine in normal, senile and diabetic cataractous human lenses.

An attempt has been made to explore the possible role of Taurine in cataractogenesis. Normal lenses were obtained from eye bank donors and cataractous lenses from patients who had undergone surgery for cataract extraction. Lenses were weighed and homogenised. Extraction, isolation and estimation of protein and taurine were carried out. It has been found that the lens wet weight increased progressively with the stage of maturation of cataract, i.e., from mature to hypermature which was significant and also with increase in age. Diabetic cataract group also showed an increase similar to that of senile cataract. Taurine and total protein decreases with different stages of maturation of cataract but not with age. It may be suggested that in the process of development of human senile cataract, there is (a) alteration in the structural integrity and permeability of lens membrane to protein and amino acids including taurine, (b) changes in the lens function including possible inhibition of proteins and amino acids (taurine) synthesis and transport across the cell membrane.

Selenite cataract and its attenuation by vitamin E in Wistar rats.

PURPOSE: To study the role of vitamin E in preventing cataract formation in experimental animals. METHODS: An experimental model (selenite cataract) was selected for this study. Selenite cataract was produced in rats by subcutaneous administration of sodium selenite. Biochemical and histological changes following induction of selenite cataract in weanling Wistar rats were studied vis-a-vis the role of vitamin E in attenuating or preventing cataractogenesis. RESULTS: Vitamin E was capable of preventing selenite cataractogenesis. Selenite cataract did not develop in 91.6% (11 of 12) and 76.7% (8 of 12) vitamin E treated rats, when administered on the 12th and 10th post partum day respectively. CONCLUSION: The study confirmed that selenite induced cataract in Wistar rats is attenuated by vitamin E.

Human lens epithelial layer in cortical cataract.

Normal and cataractous human eye lenses were studied by morphology and protein analysis. A marked decrease in protein sulfhydryl (PSH) and nonprotein sulfhydryl (NSPH) was observed in nuclear and cortical cataractous epithelia. Moreover, decrease in PSH contents and an increase in insoluble proteins were found to be correlated only in cortical cataractous epithelium which is also accompanied by various morphological abnormalities. In nuclear cataractous epithelium, however, there was very little insolubilisation of proteins. The epithelial morphology in nuclear cataracts was almost similar to normal lens epithelium. Hence, it is assumed that the protein insolubilisation and various morphological abnormalities are characteristics of cortical cataractous epithelium. This leads us to believe that opacification in cortical cataract might initiate in the epithelial layer.

Role of proteins and cholesterol in human senile cataractogenesis.

Cataracts are a major cause of blindness in man with far reaching personal, social and economic consequences. The clarity of the lens is dependent upon the maintenance of the integrity of the fiber cell plasma membrane whose important component is cholesterol. In the present study, we have demonstrated that cataract formation influences the cholesterol and protein distribution within the lens.