sirolimus and 3-methyladenosine

Genetic or nutritional deficiencies in homocysteine (Hcy)metabolism lead to the accumulation of Hcy and its metabolites in the blood. This can lead to hyperhomocysteinemia (HHcy), which is an independent risk factor for cardiovascular disease. Studies have shown that HHcy leads to endothelial dysfunction, a hallmark of atherosclerosis, which may explain this link. The precise mechanism remains unclear, but a strong possibility is excessive HHCy-induced autophagy. Autophagy has been better studied in ischemia/reperfusion (I/R) injuries, and previous work showed that Oxymatrine (OMT), a quinolizidine alkaloid, protects cells against myocardial I/R injury by inhibiting autophagy. The aim of this study was to determine whether OMT inhibits autophagy in HHcy.. Autophagy in HUVEC cells treated with Hcy in the presence and absence of OMT was visualized bytransmission electron microscopy and the degree was determined by western blotting and qRT-PCR. Small interfering RNA (siRNA)was used to determine the efficiency of Macrophage migration inhibitory factor (MIF) inhibition. Cell apoptosis wasdetected by western blotting and flow cytometric analysis.. OMT inhibited autophagy, MIF, and mTOR in HUVECs during Hcy exposure, depending on the dose. siRNA-mediated MIF knockdown decreased Hcy-induced autophagy, while administration of 3-methyladenosine and rapamycin showed that they also induce autophagy. Furthermore, OMT dose-dependently inhibited the Hcy-induced HUVEC apoptosis/death.. These results suggest that Hcy can evokeautophagy-activated HUVEC apoptosis/death via a MIF/mTOR signaling pathway, which can be reversed by OMT. Our results provide a new insight into a functional role of OMT in the prevention of Hcy-induced HUVEC injury and death.

Topics: Adenosine; Alkaloids; Apoptosis; Autophagy; Caspase 3; Homocysteine; Human Umbilical Vein Endothelial Cells; Humans; Intramolecular Oxidoreductases; Macrophage Migration-Inhibitory Factors; Microscopy, Electron, Transmission; Microtubule-Associated Proteins; Quinolizines; RNA Interference; RNA, Small Interfering; Sequestosome-1 Protein; Signal Transduction; Sirolimus; TOR Serine-Threonine Kinases

Oxidative stress plays a role in many neurological diseases. Hypoxic preconditioning (HPC) has been proposed as an intervention that protects neurons from damage by altering their response to oxidative stress. The aim of this study was to investigate the mechanisms by which HPC results in neuroprotection in cultured SH-SY5Y cells subjected to oxidative stress to provide a guide for future investigation and targeted interventions. SH-SY5Y cells were subjected to HPC protocols or control conditions. Oxidative stress was induced by H

Topics: Adenosine; Autophagy; Beclin-1; Cell Hypoxia; Cell Line, Tumor; Cell Survival; Down-Regulation; Humans; Hydrogen Peroxide; Microtubule-Associated Proteins; Oxidative Stress; Protective Agents; Reactive Oxygen Species; Sirolimus; Tumor Suppressor Protein p53