Knockdown of long non-coding RNA TUG1 depresses apoptosis of hippocampal neurons in Alzheimer's disease by elevating microRNA-15a and repressing ROCK1 expression.

OBJECTIVE: Many studies have already suggested the role of long non-coding RNAs (lncRNAs) in Alzheimer's disease (AD), but the functions of lncRNA Taurine Upregulated Gene 1 (TUG1) in AD have been scarcely discussed. This study aims to verify how TUG1 affects hippocampal neurons in AD through modulation of microRNA-15a (miR-15a)/Rho-associated protein kinase 1 (ROCK1). METHOD: AD mice was modeled through injection of ß-amyloid 25-35 (Aß25-35) into the lateral ventricle. After modeling, the mice were injected with altered TUG1 and/or miR-15a agomir lentiviruses. The spatial learning ability and memory ability of mice were detected through Morris water maze test. Hippocampal neuronal apoptosis and oxidative stress indicators in AD mice were then detected. The hippocampal neuron AD model was induced by Aß25-35. Next, the neurons were, respectively, transfected with altered TUG1 vector and/or miR-15a mimics to determine the proliferation inhibition and apoptosis of hippocampal neurons. The interactions between TUG1 and miR-15a, and between miR-15a and ROCK1 were assessed using bioinformatic prediction, dual luciferase reporter gene assay and RNA-pull-down assay. RESULTS: In the animal models, Aß25-35-induced mice exhibited decreased spatial learning and memory ability, obvious pathological injury, promoted hippocampal neuronal apoptosis and decreased antioxidant ability. TUG1 silencing and miR-15a elevation improved spatial learning ability and memory ability, ameliorated pathological injury, depressed neuronal apoptosis, and strengthened antioxidant ability of hippocampal neurons in AD mice. In cellular models, Aß25-35-treated hippocampal neurons presented inhibited neuronal viability and promoted neuronal apoptosis. TUG1 silencing and miR-15a elevation increased viability and limited apoptosis of Aß25-35-treated hippocampal neurons. TUG1 specifically bound to miR-15a, and miR-15a targeted ROCK1. CONCLUSION: Collectively, this study reveals that TUG1 knockdown restricts apoptosis of hippocampal neurons in AD by elevating miR-15a and suppressing ROCK1 expression, and provides a new therapeutic target for AD treatment.

Hydrogen-rich saline ameliorates hippocampal neuron apoptosis through up-regulating the expression of cystathionine ß-synthase (CBS) after cerebral ischemia- reperfusion in rats.

OBJECTIVES: This study aimed to evaluate the potential role of hydrogen in rats after cerebral ischemic/reperfusion (I/R) injury. MATERIALS AND METHODS: The experimental samples were composed of sham group, model group of rats that received middle cerebral artery occlusion (MCAO) for 2 hr followed by reperfusion for 24 hr, and the hydrogen saline group treated by hydro¬gen-rich saline (1 ml/kg) after MCAO. Hydrogen sulfide (H2S), S100-ßprotein (S100-ß), and neuron-specific enolase (NSE) levels were measured; the levels of malondialdehyde (MDA), reactive oxygen species (ROS), and superoxide dismutase (SOD) were detected; the histologic structure and apoptotic cells of hippocampus were observed; the expressions of cystathionine ß-synthase (CBS), nuclear factor erythroid 2-related factor 2 (Nrf2), and hemeoxygenase-1 (HO-1) were measured. Statistical analyses were performed using one-way analysis of variance (ANOVA) followed by Fisher's least significant difference (LSD) test. RESULTS: Our results showed that hydrogen up-regulated H2S levels via promoting the expression of CBS in the hippocampus, and its treatment alleviated oxidative stress via activating the expression of Nrf2 and HO-1, and then cell apoptosis reduced, furthermore, brain function improved by down-regulating the levels of S100-ßand NSE. CONCLUSION: This study showed that hydrogen-rich saline ameliorates cell injury through up-regulating the expression of CBS in the hippocampus after cerebral ischemia reperfusion (I/R) in rats, this provides new experimental evidence for the treatment of stroke with hydrogen saline.

Influence of acetylsalicylate on plasma lysophosphatidic acid level in patients with ischemic cerebral vascular diseases.

BACKGROUND AND PURPOSE: Lysophosphatidic acid (LPA) is released from activated platelets. Acetylsalicylate (aspirin) is the most commonly used antiplatelet drug. The purpose of this study is to observe whether treatment with acetylsalicylate decreases the LPA level in patients with ischemic cerebrovascular diseases. METHODS: We performed a study examining LPA level in fresh plasma in cases and controls enrolled in the LPA and Stroke Prevention Study. Level of LPA was assayed by measuring its inorganic phosphorus after separation by chromatography. RESULTS: An elevated LPA level was seen in cases (n = 254) with ischemic cerebrovascular disease (3.11+/- 1.55 micromol/l) compared with 136 healthy controls (1.77 +/- 1.04 micromol/l) (p < 0.001). Administration of aspirin (100 mg q.d.) for 1 month significantly lowered LPA level in patients (n = 142) (2.41 +/- 1.03 mu mol/l) compared with that before taking acetylsalicylate (4.06 +/- 1.03 micromol/l) (p < 0.001). However, the LPA level in patients (n = 36) who stopped acetylsalicylate after taking it for 1 month was re-elevated. Before and after taking acetylsalicylate for 1 month, their LPA levels were 4.23 +/- 1.15 and 1.93 +/- 0.85 micromol/l, respectively. After 1 month withdrawal, level was 3.90 +/- 1.09 micromol/l (p < 0.001 compared that before taking acetylsalicylate). CONCLUSION: Our findings support a close association between increased plasma LPA level and platelet activation. Acetylsalicylate could decrease plasma LPA levels, which may be used as a mechanism for acetylsalicylate in the prevention of ischemic stroke.