The effects of DNA methyl transferases on antiaging klotho gene expression

Abstract

Several intracellular metabolic pathways in which multiple genes have a role affect the aging process. One important genetic factor associated with aging is klotho gene. In some recently published studies, klotho gene has also been associated with several types of cancer and identified as a tumor suppressor gene. Therefore, elucidation of the control of klotho gene expression has become more important. Results suggesting that the promoter region of human klotho gene could be epigenetically controlled by DNA methylation have been reported. In contrast, a study revealing whether a change in the expression level of DNMT enzymes in the cells affects klotho gene expression has not been found. Herein, the effects of DNMT3A and DNMT3B enzymes on the expression of klotho gene, an important genetic factor relating to the aging process and some human cancer types, were investigated. For this purpose, the expression levels of DNMT3A and DNMT3B in HEK293 cells were artificially changed, and the effect on klotho gene promoter activity was investigated using a reporter gene. The results of this research showed that DNMT enzymes have negative regulatory effects on klotho gene promoter organized as a chromatin structure, and they have an enhancing effect on promoter activity when it is located on plasmid DNA. These results elucidate the control mechanism of human klotho gene expression.

Inhibition of DNase I Enzyme with Nickel(II) Triphenylphosphine Complexes Incorporating Tridentate Schiff Base Ligands in Vitro

“…The pHKP-Luc plasmid, purified by the plasmid DNA isolation kit from Escherichia coli DH5α cells, was used as the DNA molecule. Plasmid DNA was obtained from K.Turan (23). The reaction was carried out in 15 μL of DNase I buffer (10 mM tris, 2.5 mM MgCl2, 0.5 mM CaCl2, pH 7.5) containing 2 m units of DNase, 1 μg of plasmid DNA and 0.1, 0.01 or 0.001 μg of complex by allowing to stand for 20 minutes at 37 °C.…”