lithium-chloride and 3-methyladenine

Osteosarcoma is a common malignant bone tumor occurring in adolescents and children. The poor prognosis and low 5-year survival rate of osteosarcoma partly due to high metastasis of osteosarcoma. Triptolide (TPL), an extract from Tripterygium wilfordii, is widely used in cancer treatment. In our present study, we aimed to study the effect of TPL in osteosarcoma treatment and explore the associated regulation mechanism. Our study revealed that TPL inhibited angiogenesis by suppressing the expression of hypoxia inducible factor-1α (HIF-1α) and vascular endothelial growth factor (VEGF) in dose dependent manner. Besides, cell apoptosis was induced by TPL obviously in dose dependent manner. Further study demonstrated that TPL induced obvious cell autophagy with increased concentration. The cooperation of autophagy inhibitor 3-MA abolished the effect of TPL on anti-angiogenesis and apoptosis promoting. Moreover, we found that Wnt/β-Catenin signaling was inactivated by TPL and the adding of pathway inducer Licl neutralized the effect of TPL on autophagy induction, anti-angiogenesis and apoptosis promoting. Taken together, we suggested that TPL inhibited angiogenesis and induced cell apoptosis in osteosarcoma cells by inducing autophagy via repressing Wnt/β-Catenin signaling.

Topics: Adenine; Antineoplastic Agents, Alkylating; Apoptosis; Autophagy; beta Catenin; Cell Line, Tumor; Diterpenes; Dose-Response Relationship, Drug; Epoxy Compounds; Gene Expression Regulation, Neoplastic; Humans; Hypoxia-Inducible Factor 1, alpha Subunit; Lithium Chloride; Osteoblasts; Phenanthrenes; Signal Transduction; Vascular Endothelial Growth Factor A

This study evaluated whether lithium chloride (LiCl) prevents cytoplasmic accumulation of mutant-transforming growth factor β-induced protein (Mut-TGFBI) in granular corneal dystrophy (GCD) via activation of the autophagy pathway. Levels of TGFBI and microtubule-associated protein 1A/1B-light chain 3 (LC3) in 3 GCD patients and healthy controls were analyzed by immunohistochemistry (IHC) staining and Western blot. Primary corneal fibroblasts were isolated and transfected with wild type or mutant type TGFBI over-expressed vectors, and then treated with LiCl and/or autophagy inhibitor 3-methyladenine (3-MA). Then, levels of TGFBI, glycogen synthase kinase-3 (GSK-3) and LC3-I/-II were detected. Cell viability and transmission electron microscopy assay were also performed. Levels of TGFBI and LC3 were significantly increased in GCD patients. Over-expression of mutant type TGFBI inhibited cell viability and induced autophagy in corneal fibroblasts. LiCl downregulated the expression of TGFBI in mutant type TGFBI over-expressed cells in a dose- and time-dependent manner. LiCl enhanced autophagy in mutant type TGFBI over-expressed cells and recovered cell viability in those cells. However, the effects of LiCl were partly attenuated when autophagy was suppressed by 3-MA. To summarize, treatment with LiCl inhibited the expression of TGFBI and recovery the inhibitory of mutant type TGFBI in cell viability, at least part through enhancing of autophagy. These data strongly suggest that LiCl may be useful in the treatment of GCD.

Topics: Adenine; Adjuvants, Immunologic; Autophagy; Blotting, Western; Cell Survival; Corneal Dystrophies, Hereditary; Corneal Keratocytes; Down-Regulation; Extracellular Matrix Proteins; Fluorescent Antibody Technique, Indirect; Gene Expression Regulation; Glycogen Synthase Kinase 3; Humans; Immunohistochemistry; Lithium Chloride; Microscopy, Electron, Transmission; Microtubule-Associated Proteins; Real-Time Polymerase Chain Reaction; Transfection; Transforming Growth Factor beta

Trimethyltin (TMT) is a triorganotin compound which determines neurodegeneration of specific brain areas particularly damaging the limbic system. Earlier ultrastructural studies indicated the formation of autophagic vacuoles in neurons after TMT intoxication. However, no evaluation has been attempted to determine the role of the autophagic pathway in TMT neurotoxicity. To assess the contribution of autophagy to TMT-induced neuronal cell death, we checked the vulnerability of neuronal cultures to TMT after activation or inhibition of autophagy. Our results show that autophagy inhibitors (3-methyladenine and L-asparagine) greatly enhanced TMT neurotoxicity. Conversely, known activators of autophagy, such as lithium and rapamycin, displayed neuroprotection against this toxic compound. Due to its diverse targets, the action of lithium was complex. When lithium was administered according to a chronic treatment protocol (6 days pretreatment) it was able to rescue both hippocampal and cortical neurons from TMT (or from glutamate toxicity used as reference). This effect was accompanied by an increased phosphorylation of glycogen synthase kinase 3 which is a known target for lithium neuroprotection. If the pre-incubation time was reduced to 2 h (acute treatment protocol), lithium was still able to counteract TMT toxicity in hippocampal but not in cortical neurons. The neuroprotective effect of lithium acutely administered against TMT in hippocampal neurons can be completely reverted by an excess of inositol and is possibly related to the inactivation of inositol monophosphatase, a key regulator of autophagy. These data indicate that TMT neurotoxicity can be dramatically modified, at least in vitro, by lithium addition which seems to act through different mechanisms if acutely or chronically administered.

Topics: Adenine; Adjuvants, Immunologic; Aldehydes; Analysis of Variance; Animals; Asparagine; Autophagy; Brain; Cell Count; Cells, Cultured; Dose-Response Relationship, Drug; Embryo, Mammalian; Glycogen Synthase Kinase 3; Glycogen Synthase Kinase 3 beta; L-Lactate Dehydrogenase; Lithium Chloride; Mice; Mice, Inbred C57BL; Microscopy, Electron, Transmission; Mitochondria; Neurons; Phosphorylation; Serine; Sirolimus; Tetrazolium Salts; Thiazoles; Trimethyltin Compounds; Vacuoles

To investigate the in vivo functions of normal prion protein (PrP) in Drosophila, we utilized characterized transgenic flies expressing ³(F)⁴-tagged mouse PrP (Mo-PrP³(F)⁴). The neurotoxicity of pathogenic Machado-Joseph Disease (MJD) glutamine (Q) 78 and 127Q proteins were enhanced by the co-expression of Mo-PrP³(F)⁴in the fly eyes, while the eyes of controls flies and flies expressing Mo-PrP³(F)⁴) alone or together with MJD-Q27 or 20Q proteins did not show any defect. Susceptibilities to H₂O₂, paraquat, and Dithiothreitol (DTT) were altered in Mo-PrP³(F)⁴ flies. In addition, Mo-PrP³(F)⁴ flies were significantly more susceptible to the perturbation of autophagy signaling by an autophagy inhibitor, 3-methyladenine (3-MA), and inducer, LiCl. Taken together, our data suggest that Mo-PrP³(F)⁴ may enhance the neurotoxicity of pathogenic Poly-Q proteins by perturbing oxidative and autophagy signaling.

Topics: Adenine; Animals; Animals, Genetically Modified; Autophagy; Disease Models, Animal; Dithiothreitol; Drosophila melanogaster; Eye; Lithium Chloride; Machado-Joseph Disease; Mice; Models, Genetic; Neurons; Oxidative Stress; Paraquat; Peptides; Prions; Unfolded Protein Response; Water