Effect of hyperhomocysteinemia on proteolytic activity in the spleen

Background: The aim of the study was to investigate the effect of hyperhomocysteinemia (HC) on proteolytic activity in the spleen of rats. Methods: Albino nonlinear male rats of different ages (young, adults, and old) were involved in the study. HC was induced by intragastric administration of DL-homocysteine thiolactone. The total proteolytic activity was evaluated using casein as a substrate. The activity of metal-dependent and serine proteases was determined using proteases inhibitors ethylenediaminetetraacetic acid and phenylmethylsulfonyl. The levels of matrix metalloproteinases (MMPs), tissue inhibitors of metalloproteinases (TIMPs), and cytokines were measured by enzyme-linked immunosorbent assay. The fraction of serine proteases was isolated by affinity chromatography. Results: HC causes an increase in the total proteolytic activity, which is due to an increase in the activity of proteases of various catalytic types (serine, cysteine, aspartic proteases, and metal-dependent enzymes). The levels of MMP-2, MMP-3, MMP-8, and MMP-10 were significantly reduced in the spleen of adult and old rats and were at the control level in young rats. A disorder of the balance between MMP-1 and TIMP-1 in the spleen of rats with HC in favor of the active form of MMP-1 was revealed. At the same time, the level of serine proteases was increased in the spleen of rats of all groups. A decrease in the level of some pro-inflammatory cytokines was also revealed. Conclusions: HC causes disturbances in the proteolytic balance, manifested by an increase in proteolytic activity. The pathogenesis of this disease is not associated with the development of inflammation in the spleen.