1.Expression of Vesicular Nucleotide Transporter in the Mouse Retina.
Moriyama S1, Hiasa M. Biol Pharm Bull. 2016;39(4):564-9. doi: 10.1248/bpb.b15-00872.
Vesicular nucleotide transporter (VNUT) is a membrane protein that is responsible for vesicular storage and subsequent vesicular release of nucleotides, such as ATP, and plays an essential role in purinergic chemical transmission. In the present study, we investigated whether VNUT is present in the rodent retina to define the site(s) of vesicular ATP release. In the mouse retina, reverse transcription polymerase chain reaction (RT-PCR) and immunological analyses using specific anti-VNUT antibodies indicated that VNUT is expressed as a polypeptide with an apparent molecular mass of 59 kDa. VNUT is widely distributed throughout the inner and outer retinal layers, particularly in the outer segment of photoreceptors, outer plexiform layer, inner plexiform layer, and ganglion cell layer. VNUT is colocalized with vesicular glutamate transporter 1 and synaptophysin in photoreceptor cells, while it is colocalized with vesicular γ-aminobutyric acid (GABA) transporter in amacrine cells and bipolar cells.
2.MAP30 inhibits autophagy through enhancing acetyltransferase p300 and induces apoptosis in acute myeloid leukemia cells.
Qian S1, Sun L1, Li J1, Wu J1, Hu G1, Han Y2, Yu K1, Zhang S1. Oncol Rep. 2016 Mar 24. doi: 10.3892/or.2016.4705. [Epub ahead of print]
Momordica anti-human immunodeficiency virus protein of 30 kDa (MAP30) has been shown to exhibit potent antitumor activities against several solid tumors. In the present investigation we demonstrated that MAP30 significantly inhibited the proliferation of acute myeloid leukemia (AML) HL-60 and THP-1 cell lines and patient AML cells through autophagy inhibition and apoptosis induction. Intriguingly, MAP30-induced cell death and apoptosis were partially rescued in combination with an autophagy activator rapamycin, and aggravated in combination with an autophagy inhibitor bafilomycin A1 in HL-60 cells, suggesting that autophagy is a pro-survival signal and its inhibition contributes to the induction of apoptosis in MAP30‑induced cell death. Further mechanism analysis demonstrated that MAP30 enhanced p300, and C646, a selective inhibitor of p300, markedly promoted autophagy and partially rescued the MAP30-induced cell death in HL-60 cells and patient AML cells.
3.Iron-Mediated Lysosomal Membrane Permeabilization in Ethanol-Induced Hepatic Oxidative Damage and Apoptosis: Protective Effects of Quercetin.
Li Y1, Chen M2, Xu Y2, Yu X2, Xiong T2, Du M2, Sun J2, Liu L2, Tang Y2, Yao P2. Oxid Med Cell Longev. 2016;2016:4147610. doi: 10.1155/2016/4147610. Epub 2015 Dec 28.
Iron, in its free ferrous states, can catalyze Fenton reaction to produce OH∙, which is recognized as a crucial role in the pathogenesis of alcoholic liver diseases (ALD). As a result of continuous decomposition of iron-containing compounds, lysosomes contain a pool of redox-active iron. To investigate the important role of intralysosomal iron in alcoholic liver injury and the potential protection of quercetin, male C57BL/6J mice fed by Lieber De Carli diets containing ethanol (30% of total calories) were cotreated by quercetin or deferoxamine (DFO) for 15 weeks and ethanol-incubated mice primary hepatocytes were pretreated with FeCl3, DFO, and bafilomycin A1 at their optimal concentrations and exposure times. Chronic ethanol consumption caused an evident increase in lysosomal redox-active iron accompanying sustained oxidative damage. Iron-mediated ROS could trigger lysosomal membrane permeabilization (LMP) and subsequent mitochondria apoptosis.
4.Autophagy inhibition in endogenous and nutrient-deprived conditions reduces dorsal root ganglia neuron survival and neurite growth in vitro.
Clarke JP1, Mearow K1. J Neurosci Res. 2016 Mar 28. doi: 10.1002/jnr.23733. [Epub ahead of print]
Peripheral neuropathies can result in cytoskeletal changes in axons, ultimately leading to Wallerian degeneration and cell death. Recently, autophagy has been studied as a potential target for improving axonal survival and growth during peripheral nerve damage. This study investigates the influence of autophagy on adult dorsal root ganglia (DRG) neuron survival and axonal growth under control and nutrient deprivation conditions. Constitutive autophagy was modulated with pharmacological activators (rapamycin; Rapa) and inhibitors (3-methyladenine, bafilomycin A1) in conjunction with either a nutrient-stable environment (standard culture medium) or a nutrient-deprived environment (Hank's balanced salt solution + Ca2+ /Mg2+ ). The results demonstrated that autophagy inhibition decreased cell viability and reduced neurite growth and branching complexity. Although autophagy was upregulated with nutrient deprivation compared with the control, it was not further activated by rapamycin, suggesting a threshold level of autophagy.