title: The neuroprotective role and mechanisms of TERT in neurons with oxygen-glucose deprivation.
abstract: Telomerase reverse transcriptase (TERT) is reported to protect neurons from apoptosis induced by various stresses including hypoxia-ischemia (HI). However, the mechanisms by which TERT exerts its anti-apoptotic role in neurons with HI injury remain unclear. In this study, we examined the protective role and explored the possible mechanisms of TERT in neurons with HI injury in vitro. Primary cultured neurons were exposed to oxygen and glucose deprivation (OGD) for 3h followed by reperfusion to mimic HI injury in vivo. Plasmids containing TERT antisense, sense nucleotides, or mock were transduced into neurons at 48h before OGD. Expression and distribution of TERT were measured by immunofluorescence labeling and western blot. The expression of cleaved caspase 3 (CC3), Bcl-2 and Bax were detected by western blot. Neuronal apoptosis was measured with terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL). The mitochondrial reactive oxygen species (ROS) were measured by MitoSOX Red staining. Fluorescent probe JC-1 was used to measure the mitochondrial membrane potential (ΔΨm). We found that TERT expression increased at 8h and peaked at 24h in neurons after OGD. CC3 expression and neuronal apoptosis were induced and peaked at 24h after OGD. TERT inhibition significantly increased CC3 expression and neuronal apoptosis after OGD treatment. Additionally, TERT inhibition decreased the expression ratio of Bcl-2/Bax, and enhanced ROS production and ΔΨm dissipation after OGD. These data suggest that TERT plays a neuroprotective role via anti-apoptosis in neurons after OGD. The underlying mechanisms may be associated with regulating Bcl-2/Bax expression ratio, attenuating ROS generation, and increasing mitochondrial membrane potential.
authors: Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu 610041, China; Key Laboratory of Obstetric & Gynecologic and Pediatric Diseases and Birth Defects of Ministry of Education, Sichuan University, 610041 Chengdu, Sichuan, China.
authors: J
authors: J
authors: Li
authors: Y
authors: Y
authors: Qu
authors: D
authors: D
authors: Chen
authors: L
authors: L
authors: Zhang
authors: F
authors: F
authors: Zhao
authors: L
authors: L
authors: Luo
authors: L
authors: L
authors: Pan
authors: J
authors: J
authors: Hua
authors: D
authors: D
authors: Mu
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D015153:Blotting, Western; D002478:Cells, Cultured; D005455:Fluorescent Antibody Technique; D005947:Glucose / Q000172:deficiency; D020925:Hypoxia-Ischemia, Brain / Q000378:metabolism*; D020287:In Situ Nick-End Labeling; D053078:Membrane Potential, Mitochondrial / Q000502:physiology; D009474:Neurons / Q000378:metabolism*; D010100:Oxygen / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D017382:Reactive Oxygen Species / Q000378:metabolism; D019098:Telomerase / Q000378:metabolism*; D014161:Transduction, Genetic
chemical_list: D017382:Reactive Oxygen Species; D019098:Telomerase; D005947:Glucose; D010100:Oxygen
keywords: AI; CC3; DIV; HBSS; HI; IPP; MAP-2; NB; OD; OGD; PBS; ROS; SD; Sprague–Dawley; TERT; TUNEL; apoptosis; apoptotic index; cleaved caspase 3; day in vitro; hank’s buffered salt solution; hypoxia–ischemia; image pro plus; microtubule associated protein 2; mitochondrial membrane potential; neurobasal; neuron; optical density; oxygen and glucose deprivation; phosphate-buffered Saline; rTdT; reactive oxygen species; standard deviation; telomerase reverse transcriptase; terminal deoxynucleotidyl transferase, recombinant; terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling; ΔΨm