Telomerase activity and telomerase reverse transcriptase expression induced by selenium in rat hepatocytes

Area of Science:

• Biochemistry
• Cell Biology
• Gerontology

Background:

• Selenium is an essential trace element with antioxidant properties.
• Telomerase activity, apoptosis, and specific gene expressions (TERT, c-myc, p53) are crucial in cellular senescence and aging.

Purpose of the Study:

• To investigate the effects of sodium selenite on rat hepatocytes.
• To analyze its impact on telomerase activity, apoptosis, and the expression of TERT, c-myc, and p53.

Main Methods:

• Rats were administered varying doses of sodium selenite (2.5, 5.0, 10 micromol/kg) via gavage.
• Telomerase activity was measured using the TRAP assay.
• Apoptosis was assessed via flow cytometry.
• Gene and protein expression levels of TERT, c-myc, and p53 were analyzed using RT-PCR and immunochemistry.

Main Results:

• Sodium selenite significantly increased telomerase activity and induced apoptosis in a dose-dependent manner.
• While TERT mRNA expression showed no significant change, c-myc and p53 mRNA levels were elevated at the highest dose (10 micromol/kg).
• P53 protein content increased at 5.0 and 10 micromol/kg, with c-Myc protein significantly promoted only at 10 micromol/kg.

Conclusions:

• Selenium can enhance telomerase activity and TERT expression, while significantly inducing apoptosis and over-expression of c-myc and p53 at higher doses.
• These effects suggest that selenium's potential benefits in senescence and aging may involve modulation of telomerase and key regulatory genes in hepatocytes.