The SMAC mimetic LCL-161 selectively targets JAK2V617F mutant cells.

Background:Evasion from programmed cell death is a hallmark of cancer and can be achieved in cancer cells by overexpression of inhibitor of apoptosis proteins (IAPs). Second mitochondria-derived activator of caspases (SMAC) directly bind to IAPs and promote apoptosis; thus, SMAC mimetics have been investigated in a variety of cancer types. particularly in diseases with high inflammation and NFĸB activation. Given that elevated TNFα levels and NFĸB activation is a characteristic feature of myeloproliferative neoplasms (MPN), we investigated the effect of the SMAC mimetic LCL-161 on MPN cell survival in vitro and disease development in vivo. Methods:To investigate the effect of the SMAC mimetic LCL-161 in vitro, we utilized murine and human cell lines to perform cell viability assays as well as primary bone marrow from mice or humans with JAK2V617F-driven MPN to interrogate myeloid colony formation. To elucidate the effect of the SMAC mimetic LCL-161 in vivo, we treated a JAK2V617F-driven mouse model of MPN with LCL-161 then assessed blood counts, splenomegaly, and myelofibrosis. Results:We found that JAK2V617F-mutated cells are hypersensitive to the SMAC mimetic LCL-161 in the absence of exogenous TNFα. JAK2 kinase activity and NFĸB activation is required for JAK2V617F-mediated sensitivity to LCL-161, as JAK or NFĸB inhibitors diminished the differential sensitivity of JAK2V617F mutant cells to IAP inhibition. Finally, LCL-161 reduces splenomegaly and may reduce fibrosis in a mouse model of JAK2V617F-driven MPN. Conclusion:LCL-161 may be therapeutically useful in MPN, in particular when exogenous TNFα signaling is blocked. NFĸB activation is a characteristic feature of JAK2V617F mutant cells and this sensitizes them to SMAC mimetic induced killing even in the absence of TNFα. However, when exogenous TNFα is added, NFĸB is activated in both mutant and wild-type cells, abolishing the differential sensitivity. Moreover, JAK kinase activity is required for the differential sensitivity of JAK2V617F mutant cells, suggesting that the addition of JAK2 inhibitors to SMAC mimetics would detract from the ability of SMAC mimetics to selectively target JAK2V617F mutant cells. Instead, combination therapy with other agents that reduce inflammatory cytokines but preserve JAK2 signaling in mutant cells may be a more beneficial combination therapy in MPN

Active Learning in Introductory Economics: Do MyEconLab and Aplia Make Any Difference?

This paper reports experiment results of teaching large classes of introductory economics with modern learning technology such as MyEconLab or Aplia. This new technology emerges partially in response to the enrollment pressure currently facing many institutions of higher education. Among other things, the technology provides an integrated online teaching and learning environment that allows active learning through student direct participation in the learning process as well as interaction with their instructor, peers, and the outside Internet. Our results showed that, for the classes in the experiment, modern learning technology could make a difference in helping students improve their class mark averages by a small but statistically significant amount of 2% regardless whether the technology was used as a required or optional course component. We noted that students responded more favorably when the technology component was given more weight in the marking scheme

Mechanisms of enhanced non-viral gene delivery to human mesenchymal stem cells induced by glucocorticoid priming

Background: Because of unique roles in wound healing, trophic tissue support, immunomodulation, differentiation ability, and immune privileged status, human mesenchymal stem cells (hMSCs), which can be easily derived from many adult tissues (e.g. bone marrow (BMSCs) and adipose tissue (AMSCs)), are under intense study for the applications of cell and gene therapeutics, as well as tissue engineering and regenerative medicine1. Genetic modification of hMSCs could allow for targeted delivery of transgenic therapeutic factors or genetically-guided differentiation. Non-viral gene delivery (i.e. cationic polymer- and lipid-mediated) is safer and more flexible than immunogenic and mutagenic viral vectors2, but it is less effective, especially in hMSCs (i.e. maximum 10-30% transfection)3. As part of an approach to understand molecular mechanisms of non-viral gene delivery4 and ‘prime’ cells to be more receptive to transfection5, our lab recently demonstrated that transgene expression from lipofected hMSCs can be increased about 10-fold by priming cells, 30 mins before plasmid DNA (pDNA) transfection, with 100 nM dexamethasone (DEX), a glucocorticoid (Gc) drug, relative to EtOH vehicle control (VC)6. This work investigates the mechanisms by which Gc priming enhances non-viral gene delivery, which are currently unknown. Studies provide insights into the biological processes of Gc priming and transfection to inform future gene delivery technologies, and characterize a simple protocol to significantly enhance non-viral gene delivery of therapeutic transgenes for future clinical applications. Please click Additional Files below to see the full abstract

Nucleic acid delivery to mesenchymal stem cells: a review of nonviral methods and applications

Background: Mesenchymal stem cells (MSCs) are multipotent stem cells that can be isolated and expanded from many tissues, and are being investigated for use in cell therapies. Though MSC therapies have demonstrated some success, none have been FDA approved for clinical use. MSCs lose stemness ex vivo, decreasing therapeutic potential, and face additional barriers in vivo, decreasing therapeutic efficacy. Culture optimization and genetic modification of MSCs can overcome these barriers. Viral transduction is efficient, but limited by safety concerns related to mutagenicity of integrating viral vectors and potential immunogenicity of viral antigens. Nonviral delivery methods are safer, though limited by inefficiency and toxicity, and are flexible and scalable, making them attractive for engineering MSC therapies. Main text: Transfection method and nucleic acid determine efficiency and expression profile in transfection of MSCs. Transfection methods include microinjection, electroporation, and nanocarrier delivery. Microinjection and electroporation are efficient, but are limited by throughput and toxicity. In contrast, a variety of nanocarriers have been demonstrated to transfer nucleic acids into cells, however nanocarrier delivery to MSCs has traditionally been inefficient. To improve efficiency, plasmid sequences can be optimized by choice of promoter, inclusion of DNA targeting sequences, and removal of bacterial elements. Instead of DNA, RNA can be delivered for rapid protein expression or regulation of endogenous gene expression. Beyond choice of nanocarrier and nucleic acid, transfection can be optimized by priming cells with media additives and cell culture surface modifications to modulate barriers of transfection. Media additives known to enhance MSC transfection include glucocorticoids and histone deacetylase inhibitors. Culture surface properties known to modulate MSC transfection include substrate stiffness and specific protein coating. If nonviral gene delivery to MSCs can be sufficiently improved, MSC therapies could be enhanced by transfection for guided differentiation and reprogramming, transplantation survival and directed homing, and secretion of therapeutics. We discuss utilized delivery methods and nucleic acids, and resulting efficiency and outcomes, in transfection of MSCs reported for such applications. Conclusion: Recent developments in transfection methods, including nanocarrier and nucleic acid technologies, combined with chemical and physical priming of MSCs, may sufficiently improve transfection efficiency, enabling scalable genetic engineering of MSCs, potentially bringing effective MSC therapies to patients

The Effects of Musical Mood and Musical Arousal on Visual Attention

The presence of music is a visceral part of the human experience and its influence on cognitive function is a growing area of research in psychology. In particular, perceptual properties of music (mood and arousal) have been shown to significantly affect performance. There has been minimal research in the field on the interaction of mood and arousal and their influence on attention, thus the purpose of this study. Fifty undergraduate students currently enrolled at the University of Western Ontario were recruited for this study. Given that music is a highly subjective experience, participants rated an assortment of music clips on their mood and arousal levels. The clips that participants rated highest and lowest on mood (positive and negative) and arousal (low and high) were chosen for use on the Posner cueing task. This visual attention task was either performed in silence or while listening to music clips as per their ratings. Results indicated that musical mood and musical arousal, independently of one another, had no significant effect on visual attention. Rather, a significant interaction between the two perceptual properties was observed. The fastest reaction times were recorded when participants listened to high arousal positive music and the longest reaction times were found when participants listened to high arousal negative music. Intermediate performance occurred when participants listened to low arousal negative music and low arousal positive music. Future studies should investigate whether the combined modulatory effects of musical mood and musical arousal generalize to other attentional paradigms

“It’s a puzzle!” Elementary School-AgedYouth Concept-Mapping the Intersections ofCommunity Narratives

We present a concept-mapping activity, developed within a youth Participatory Action Research (yPAR) after-school program, to demonstrate how the activity contributed to young people’s conceptualization of social structures as interconnected. We analyze fieldnotes from the Change 4 Good yPAR program, which includes primarily Latina/o 4th and 5th grade students attending a California public elementary school. We discuss the concept-mapping activity in terms of its processes and outcomes, and how youth constructed interconnected meanings from thematic community narratives

Malignant ventricular arrhythmias induction by programmed electrical stimulation of the right ventricular outflow tract only during type 1 brugada ECG maximization

OBJECTIVE: The role of electrophysiology study in Brugada syndrome (BS) sudden cardiac death risk stratification remains controversial and seems to depend on the phenotypic expression of the channelopathy. Ajmaline has a key role in the diagnosis of BS. We observed that programmed electrical stimulation (PES) of the right ventricular outflow tract (RVOT), only when type 1 BS ECG is unmasked by ajmaline administration, induces ventricular arrhythmias. CASE REPORT: We describe a case of ventricular fibrillation induction by PES of the RVOT when type 1 BS ECG is revealed by ajmaline, in a patient with a baseline dynamic intermittent type 1 and 2 BS ECG. CONCLUSIONS: The heterogeneous clinical presentations of BS are due to the underlying mechanisms. PES of the RVOT during positive ajmaline test maximizes the channelopathy and therefore sudden cardiac death risk-stratification in BS