DNase I Induces Other Endonucleases in Kidney Tubular Epithelial Cells by Its DNA-Degrading Activity

International Journal of Molecular Sciences

AlexeiG. Basnakian¹  Tariq Fahmi¹  DmitryD. Zhdanov¹  EugeneO. Apostolov¹  Intisar Islam¹  AlenaV. Savenka¹  Xiaoying Wang¹ 

[1] Department of Pharmacology & Toxicology, University of Arkansas for Medical Sciences, 4301 West Markham Street, 638, Little Rock, AR 72205, USA;

关键词: DNase I;    endonucleases;    DNA breaks;    cell death;    apoptosis;   

DOI  :  10.3390/ijms21228665

来源: DOAJ

【 摘 要 】

Endonuclease-mediated DNA fragmentation is both an immediate cause and a result of apoptosis and of all other types of irreversible cell death after injury. It is produced by nine enzymes including DNase I, DNase 2, their homologs, caspase-activated DNase (CAD) and endonuclease G (EndoG). The endonucleases act simultaneously during cell death; however, regulatory links between these enzymes have not been established. We hypothesized that DNase I, the most abundant of endonucleases, may regulate other endonucleases. To test this hypothesis, rat kidney tubular epithelial NRK-52E cells were transfected with the DNase I gene or its inactive mutant in a pECFP expression vector, while control cells were transfected with the empty vector. mRNA expression of all nine endonucleases was studied using real-time RT-PCR; DNA strand breaks in endonuclease genes were determined by PCR and protein expression of the enzymes was measured by Western blotting and quantitative immunocytochemistry. Our data showed that DNase I, but not its inactive mutant, induces all other endonucleases at varying time periods after transfection, causes DNA breaks in endonuclease genes, and elevates protein expression of several endonucleases. This is the first evidence that endonucleases seem to be induced by the DNA-degrading activity of DNase I.

【 授权许可】

Unknown