Showing transmitters the door: synucleins accelerate vesicle release

Global ubiquitome analysis of substantia nigra in doubly-mutant human alpha-synuclein transgenic mice

Progression through neuronal loss of substantia nigra pars compacta (SNpc) with Parkinson's disease depends on various protein post-translational modifications mainly comprising ubiquitination. Although many ubiquitination sites have been identified through site-specific methods, systematic quantitative proteomic analysis of pre-symptomatic Parkinson's disease remains unexplored. Using quantitative proteomics, we have globally profiled ubiquitination in SNpc tissue of a Parkinson's disease transgenic mouse model (A30P*A53 T α-synuclein, hm²α-SYN-39 mouse strain) at pre-symptomatic stage; Our datasets of 3971 ubiquitination sites in 1595 proteins provide valuable insight into pre-symptomatic Parkinson's disease. Subsequent bioinformatics analysis, including gene ontology analysis, KEGG pathway annotation, functional cluster analysis, and motif analysis were performed to annotate quantifiable targets of ubiquitination sites. Therefore, this elucidation of the dysregulation of ubiquitination has implications for understanding the pathophysiological mechanism of dopaminergic neuron degeneration and for developing novel therapeutics for Parkinson's disease.

Harpagide, a natural product, promotes synaptic vesicle release as measured by nanoelectrode amperometry

Parkinson's disease (PD) is a neurodegenerative disorder characterized by progressive loss of dopaminergic (DAergic) neurons and low level of dopamine (DA) in the midbrain. Recent studies suggested that some natural products can protect neurons against injury, but their role on neurotransmitter release and the underlying mechanisms remained unknown. In this work, nanoelectrode electrochemistry was used for the first time to quantify DA release inside single DAergic synapses. Our results unambiguously demonstrated that harpagide, a natural product, effectively enhances synaptic DA release and restores DA release at normal levels from injured neurons in PD model. These important protective and curative effects are shown to result from the fact that harpagide efficiently inhibits the phosphorylation and aggregation of α-synuclein by alleviating the intracellular reactive oxygen level, being beneficial for vesicle loading and recycling. This establishes that harpagide offers promising avenues for preventive or therapeutic interventions against PD and other neurodegenerative disorders.

Nanoelectrode amperometry was used to monitor DA release inside single DAergic synapses, and demonstrated that harpagide effectively enhances synaptic DA release by reducing intracellular ROS generation and inhibiting α-Syn phosphorylation.

The contemporary role and impact of urine-based biomarkers in bladder cancer

Despite advances in the surgical and medical treatment of bladder cancer, there have only been minor improvements in mortality and morbidity rates over the past decades. Urine-based markers help to improve diagnosing bladder cancer with the aim of complementing or probably in future replacing cystoscopy. Biomarkers may allow individualized risk stratification and support decision-making regarding therapy and follow-up. This review summarizes the existing urine-based biomarkers in bladder cancer. We conducted a comprehensive review of the literature. We conducted a PubMed/Medline based research on English language articles and selected original articles and review articles that provided both description and assessment of urinary markers at time of screening, initial diagnosis, monitoring and prognostic evaluation of urothelial bladder cancer. Our research covered studies published between 2000 and 2017. The aim of this study was to give clinicians keys to understand the existing or promising urinary markers that may become alternatives to cytology/cystoscopy pair in the near future. Many urinary markers are now available, often with superior sensitivity to cytology. Their uses have been evaluated in numerous clinical situations in addition to the time of initial diagnosis and surveillance such as cases of isolated macroscopic hematuria or atypical cytology discordant with the rest of the explorations. However, their superiority over the cytology/cystoscopy association is not demonstrated. These new markers are lacking for the most part of standardization and simplicity making their use in common practice difficult. the types and forms of these new markers are very heterogeneous among themselves and between the studies that evaluate them. Well-designed protocols and prospective, controlled trials are needed to provide the basis to determine whether integration of urine- and blood-based biomarkers into clinical decision-making will be of value for bladder cancer detection and screening in the future.

Valproic Acid Induces Endocytosis-Mediated Doxorubicin Internalization and Shows Synergistic Cytotoxic Effects in Hepatocellular Carcinoma Cells

Valproic acid (VPA), a well-known histone deacetylase (HDAC) inhibitor, is used as an anti-cancer drug for various cancers, but the synergistic anti-cancer effect of VPA and doxorubicin (DOX) combination treatment and its potential underlying mechanism in hepatocellular carcinoma (HCC) remain to be elucidated. Here, we evaluate the mono- and combination-therapy effects of VPA and DOX in HCC and identify a specific and efficient, synergistic anti-proliferative effect of the VPA and DOX combination in HCC cells, especially HepG2 cells; this effect was not apparent in MIHA cells, a normal hepatocyte cell line. The calculation of the coefficient of drug interaction confirmed the significant synergistic effect of the combination treatment. Concurrently, the synergistic apoptotic cell death caused by the VPA and DOX combination treatment was confirmed by Hoechst nuclear staining and Western blot analysis of caspase-3 and poly (ADP-ribose) polymerase (PARP) activation. Co-treatment with VPA and DOX enhanced reactive oxygen species (ROS) generation and autophagy, which were clearly attenuated by ROS and autophagy inhibitors, respectively. Furthermore, as an indication of the mechanism underlying the synergistic effect, we observed that DOX internalization, which was induced in the VPA and DOX combination-treated group, occurred via by the caveolae-mediated endocytosis pathway. Taken together, our study uncovered the potential effect of the VPA and DOX combination treatment with regard to cell death, including induction of cellular ROS, autophagy, and the caveolae-mediated endocytosis pathway. Therefore, these results present novel implications in drug delivery research for the treatment of HCC.