HIV-1 Vpr accessory protein has a negative impact on astrocityc telomerase activity

OJEDA D.; QUARLERI J.; CAROBENE M

Washintong

Simposio; The 12th International Symposium on NeuroVirology; 2013

HIV-1 Infection leads to a wide spectrum of neurodegenerative diseases. Among central nervous system cells, astrocytes have been shown to be susceptible to HIV-1 infection. Vpr is an HIV- 1 accessory protein that negatively affects the highly controlled CNS compartment, inducing astrocytic apoptosis and secretion of neurotoxins that causes neuronal loss. Telomerase is a cellular ribonucleoprotein complex key in controlling cellular senes- cence, and involved in inhibition of apoptosis and improvement of DNA repair. Considering that HIV-1 has been shown to modify the cellular aging process by interfering with telomerase activity (TA), the aim of our study was to evaluate the impact of Vpr protein expression on TA in astrocytes. Vpr coding se- quence from HIV-1 NL4-3 strain was PCR-amplified and cloned into the pEGFP-C3 expression vector. U373 astrocytic cells were transfected with the pEGFP-Vpr vector, and TA was eval- uated by real-time PCR (expressed as Relative Telomerase Activity, RTA), 48 h post-transfection. Transfection efficiency, expressed as percentage of GFP-positive cells, was measured by FACS. Statistical differences were calculated by t-student test. Telomerase activity (RTA) was found to be significantly reduced in U373 astrocytic cells transfected with the HIV-1 Vpr- expression vector (25.7% RTA, p