[The pirymethamine influence on hexosoaminidase gene expression in synovial cell culture--preliminary report].

UNLABELLED: Inflammation process is leading to increasing of synovial fluid and value of its pressure. Moreover, the impairment of vascular flow within synovial membrane and increased permeability of blood vessels were described. The activity of lysosomal enzymes, such as N-acetyl-beta-glucosaminidase (HEX), was increased in patients with rheumatoid arthritis in comparison to health synovial fluid. It is supposed, that HEX takes part in joint destruction. The using of HEX inhibitors in synovial cell culture and evaluation of HEX mRNA expression before and after the adding of inhibitor may contribute in showing the new ways of understanding pathogenetic pathways of motion organ disorders. THE AIM of the study was to evaluate the expression of HEXA and HEXB genes in the synovial cell culture derived from human synovial inflammatory fluid obtained from patients suffered from rheumatoid arthritis. MATERIAL AND METHODS: The inflamed synovial fluid was taken from patients suffered from rheumatoid arthritis. The following solutions of potential inhibitor--pyrimethamine were used: 20 microg/ml, 10 microg/ml, 3 microg/ml and 1.5 microg/ml. Two separate control groups were established: control group 1 where only 0.6% of ethanol was added to the synovial cell culture; control group 2 where only 0.5% DMSO was added to the synovial cell culture. The relative quantitative real-time reverse transcriptase polymerase chain reaction (RT-PCR) was carried out. RESULTS. The difference in HEXA and HEXB expression was observed in synoviocytes obtained in synovial cell culture. Five time higher relative HEXA expression was determined after applying 3 microg/ml of pirymethamine compared with the control 1. The highest concentration of pirymethamine (10 and 20 microg/ml) caused the least elevation of HEXA expression. The slight decreased of HEXB expression was observed under the concentration of pirymethamine: 1.3 and 3 microg/ml. CONCLUSIONS. Pyrimethamine contributes to regulating the HEX gene expression from synovial cells. The change in gene expression level is dependent on the concentration of the pirymethamine. Our preliminary data don't let us establish the concentration of pyrimethamine that may significantly inhibit HEXA and HEXB expression. Further study may be conducted to put new insight into the pathogenesis of joint destruction in the course of rheumatoid arthritis.