Proliferative glomerulonephritis and the activity of lymphocyte DNA transcriptional enzymes

We investigated the activity of some enzymes of the transcriptive DNA system to assess lymphocyte metabolic potential in patients with proliferative glomerulopathies. This study included analysis of the activity of three classes DNA-dependent RNA polymerases, before and 6 months after immunosuppressive therapy (Azathioprine + Prednisone). The enzyme activity was measured in nuclear extracts of T and B lymphocytes by estimation of the uptake of 3/H/UTP in the presence of alpha-amanitine. The immunoblotting technique using anti-polymerase I antibodies and nuclear proteins separation with immobilized exogenous DNA were employed to assess a type of the increase of the DNA-dependent RNA polymerase activity in lymphocytes populations (enhancement of the synthesis or limited depolymerization and degradation of the active enzyme). We found that the RNA polymerizing activity was increased in both lymphocyte populations. In T lymphocytes the increase was caused by an enhanced activity of transcript DNA enzymes, secondary to increased gene expression. In B lymphocytes an increase in enzyme activity was rather due to large stability RNA-polymerases in these cells. DNA-dependent RNA polymerase I in T and B cells was not modified by immunosuppression, while reduction in enzymatic activity of the remaining RNA-polymerase classes in T lymphocytes depends on partial limitation of their gene expression. Our study indicates that profound and various lymphocyte metabolic changes occur in patients with proliferative glomerulonephritis resulting from modifications in a gene expression and initiation of DNA synthesis in these cells.