Investigating the Potential Role of SIRT1 in Glioblastoma Multiforme: A Comparison Between Glioma and Normal Astrocyte Cells in Culture

<p>Objective Glioblastomas (GBMs) are the most prevalent primary brain tumours in adults and the outcome for this disease remains very poor. With treatment options limited, there is growing interest to find potential differences between normal and malignant molecular signaling pathways for this disease. SIRT1 is a histone deacetylase enzyme with key functions in cellular signaling responses including protecting DNA from damage and changing transcriptional events. SIRT1 can act as a switch to affect cellular senescence or anti-apoptotic responses, or alternatively affect autophagic and pro-apoptotic responses. The role of SIRT1 in GBM is unclear. This study aimed to investigate differences between glioma and normal astrocytes with respect to SIRT1. Research design and methods SIRT1 was analysed in murine normal and glioma astrocyte cell lines, and results compared to a normal human astrocyte cell line and a panel of human primary glioma cells taken from patients with GBM. Analysis of SIRT1 was assessed using Western blots and flow cytometry. Sub-cellular localisation was examined using Western blots and immunofluorescent microscopy. Activity for SIRT1 was assessed using acetylation of a key histone SIRT1 substrate, histone 4 lysine 16, and cell proliferation was measured using the MTT assay. Oxidative stress was induced using H₂O₂ and viability measured using propidium iodide exclusion and flow cytometry. To ascertain that activity was SIRT1 related, inhibition and activation of SIRT1 was done using nicotinamide and resveratrol, respectively. Results SIRT1 was mainly localised in the nucleus and to mitochondria of normal cells but was aberrantly distributed in the cytoplasm of glioma cells, which has not been reported before. This was consistent in both murine and human glioma models. Nicotinamide significantly inhibited cell proliferation more for glioma cells compared to normal, and resveratrol had the opposing effect. Nicotinamide rescued normal but not glioma cells from H₂0₂-induced oxidative stress, and resveratrol had the opposing effect. Western blots revealed secondary protein bands for SIRT1 indicating possible smaller species of SIRT1, and results for nuclear/cytoplasmic extractions suggested FL-SIRT1 and the smaller species of SIRT1 have a dynamic pattern of localisation under oxidative stress, nicotinamide and resveratrol treatments. Conclusions These results indicated SIRT1 is involved in both cell proliferation and oxidative stress responses, with a differential activity between glioma and normal astrocyte cells. Aberrant localisation of SIRT1 to the cytoplasm in glioma cells is a significant finding that needs further exploration. The need for further studies to elucidate changes in localisation for SIRT1 under different conditions is highlighted, as is the possible role of truncated variants of SIRT1. This study suggests there may be some potential for SIRT1 inhibition in patients suffering from glioblastoma.</p>

Investigating the Potential Role of SIRT1 in Glioblastoma Multiforme: A Comparison Between Glioma and Normal Astrocyte Cells in Culture

<p>Objective Glioblastomas (GBMs) are the most prevalent primary brain tumours in adults and the outcome for this disease remains very poor. With treatment options limited, there is growing interest to find potential differences between normal and malignant molecular signaling pathways for this disease. SIRT1 is a histone deacetylase enzyme with key functions in cellular signaling responses including protecting DNA from damage and changing transcriptional events. SIRT1 can act as a switch to affect cellular senescence or anti-apoptotic responses, or alternatively affect autophagic and pro-apoptotic responses. The role of SIRT1 in GBM is unclear. This study aimed to investigate differences between glioma and normal astrocytes with respect to SIRT1. Research design and methods SIRT1 was analysed in murine normal and glioma astrocyte cell lines, and results compared to a normal human astrocyte cell line and a panel of human primary glioma cells taken from patients with GBM. Analysis of SIRT1 was assessed using Western blots and flow cytometry. Sub-cellular localisation was examined using Western blots and immunofluorescent microscopy. Activity for SIRT1 was assessed using acetylation of a key histone SIRT1 substrate, histone 4 lysine 16, and cell proliferation was measured using the MTT assay. Oxidative stress was induced using H₂O₂ and viability measured using propidium iodide exclusion and flow cytometry. To ascertain that activity was SIRT1 related, inhibition and activation of SIRT1 was done using nicotinamide and resveratrol, respectively. Results SIRT1 was mainly localised in the nucleus and to mitochondria of normal cells but was aberrantly distributed in the cytoplasm of glioma cells, which has not been reported before. This was consistent in both murine and human glioma models. Nicotinamide significantly inhibited cell proliferation more for glioma cells compared to normal, and resveratrol had the opposing effect. Nicotinamide rescued normal but not glioma cells from H₂0₂-induced oxidative stress, and resveratrol had the opposing effect. Western blots revealed secondary protein bands for SIRT1 indicating possible smaller species of SIRT1, and results for nuclear/cytoplasmic extractions suggested FL-SIRT1 and the smaller species of SIRT1 have a dynamic pattern of localisation under oxidative stress, nicotinamide and resveratrol treatments. Conclusions These results indicated SIRT1 is involved in both cell proliferation and oxidative stress responses, with a differential activity between glioma and normal astrocyte cells. Aberrant localisation of SIRT1 to the cytoplasm in glioma cells is a significant finding that needs further exploration. The need for further studies to elucidate changes in localisation for SIRT1 under different conditions is highlighted, as is the possible role of truncated variants of SIRT1. This study suggests there may be some potential for SIRT1 inhibition in patients suffering from glioblastoma.</p>

Psi Performance as a Function of Demographic and Personality Factors in Smartphone-Based Tests

Objective: We set out to gain a better understanding of human psychic or “psi” functioning by using a smartphone-based app to gather data from thousands of participants. Our expectations were that psi performance would often be revealed to be in the direction opposite to the participants’ conscious intentions (“expectation-opposing”; previously called “psi-missing”), and that gender and psi belief would be related to performance. Method:We created and launched three iOS-based tasks, available from 2017 to 2020, related to micro-psychokinesis (the ability to mentally influence a random number generator) and precognition (the ability to predict future randomly selected events). We statistically analyzed data from more than 2,613 unique logins and 995,995 contributed trials using null hypothesis significance testing as well as a pre-registered confirmatory analysis. Results: Our expectations were confirmed, and we discovered additional effects post-hoc. Our key findings were: 1) significant expectation-opposing effects, with a confirmatory pre-registered replication of a clear expectation-opposing effect on a micro-pk task, 2) performance correlated with psi belief on all three tasks, 3) performance on two of the three tasks related to gender, 4) men and women apparently used different strategies to perform micro-pk and precognition tasks. Conclusions: We describe our recommendations for future attempts to better understand performance on forced-choice psi tasks. The mnemonic for this strategy is SEARCH: Small effects, Early and exploratory, Accrue data, Recognize diversity in approach, Characterize rather than impose, and Hone in on big results.

Activation of Rac1 Has an Opposing Effect on Induction and Maintenance of Long-Term Potentiation in Hippocampus by Acting on Different Kinases

Rac1 is a small GTPase of the Rho family. A previous study showed that the activation of Rac1 had an opposing effect on induction and maintenance of long-term potentiation (LTP) in the hippocampus. However, the molecular mechanism underlying this opposing effect remains to be addressed. In the present work, we find that the activation of Rac1 during the induction of LTP leads to an activation of PKCι/λ by phosphatidylinositol-3-kinase (PI3K), whereas the activation of Rac1 during the maintenance of LTP leads to the inhibition of PKMζ by LIM_kinase (LIMK) in the hippocampus. This result suggests that during different stages of LTP, the activation of Rac1 can modulate different signaling pathways, which leads to an opposing effect on the induction and maintenance of LTP in the hippocampus.

IRF2 Destabilizes Oncogenic KPNA2 to Modulate the Tumorigenesis of Osteosarcoma via Regulating NF-κB/p65

Background: Osteosarcomas (OS) are the most frequent primary malignant bone tumor. Emerging evidence revealed that karyopherin alpha 2 (KPNA2) was strongly associated with the tumorigenesis and development of numerous human cancers. The aim of the present study was to investigate the expression pattern, biological functions and underlying mechanism of KPNA2 in OS. Methods: Bioinformatics TFBIND online was applied to forecast the transcription factor (TF) binding sites in the promoter region of KPNA2. The expression profile of KPNA2 in OS tissues were firstly assessed using TARGET dataset. The expression of KPNA2 in clinical OS samples and normal human adjacent samples were analyzed by RT-qPCR and western blot. CCK8, colony formation, wound-healing, and Transwell assays were used to assess cell viability, proliferation and migration in vitro, and in vivo experiments were performed to explore the effects of KPNA2 and interferon regulatory factor-2 (IRF2) on tumor growth. In addition, the correlation between IRF2 and KPNA2, and their roles on the NF-κB/p65 was investigated using chromatin immunoprecipitation (ChIP), RT-qPCR, western blot and dual-luciferase assays. Results: KPNA2 was obviously upregulated while IRF2 was significantly decreased in OS tissues and cell lines, as well as they were negatively correlated with each other. KPNA2 knockdown remarkably suppressed OS cell growth, migration, invasion in vitro and tumor growth in vivo, while IRF2 knockdown exerts an opposing effect. IRF2 binds to KPNA2 promoter to modulate the tumorigenic malignant phenotypes of OS via regulating NF-κB/p65 signaling. Conclusion: The present study demonstrated that KPNA2 performed the oncogenic function, possibly regulating tumorigenesis through NF-κB/p65 signaling pathway. Importantly, IRF2 was confirmed to serve a potential upstream TF of KPNA2 involving in the regulation of NF-κB/p65 pathway in OS.

Study the Effect of Using LPG in the Spark Ignition Engine Instead of Gasoline

Apprehension on contamination carry on to collect a moral arrangement of world interest due to its opposing effect on mortal fitness beside to postponement the surroundings. Current trainings reportable the essential associations between contamination and inevitable syndromes as glowing as an occurrence, falsification, infection, chest throbbing, nausea, respiratory ailment in addition to carcinoma, acute strength properties symbolize eye frustration, headache. The global Health Organization (WHO) statuses that millions persons decease n every time with contamination. The board of this paper is focused on the production investigation totally diverse ratios of two types of coals: LPG (propane) with gasoline (petrol) below changed laedings. The rudiments laboring in the investigation covers 4stroke, spark detonation the TD200 Small Engine Investigation, Gas deconstruct part (Techno investigation (T156/D3)), Gas Movement Meter that processes the LPG. The coals, gasoline in a liter (liters) with LPG in a liter (liters) besides were castoff to assess their impressions on the consume gas production unrestricted. The consequences are apparent that particle numeral attentiveness, (CO) augmented due to the engine loading will rise in gasoline (coal). Consuming LPG, the (CO) attentiveness equal was a fewer, momentous decrease in deplete emanations, conversely extraordinary hotness in the location than coal (gasoline) on engine stocking. The engine, mechanical via LPG coal, presented amended engine presentation in numerous phases containing global efficiency, coal frugality besides emanation physical appearance that are importantly lower from gasoline coal.

Assessing Combined Effects for Mixtures of Similar and Dissimilar Acting Neuroactive Substances on Zebrafish Embryo Movement

Risk assessment of chemicals is usually conducted for individual chemicals whereas mixtures of chemicals occur in the environment. Considering that neuroactive chemicals are a group of contaminants that dominate the environment, it is then imperative to understand the combined effects of mixtures. The commonly used models to predict mixture effects, namely concentration addition (CA) and independent action (IA), are thought to be suitable for mixtures of similarly or dissimilarly acting components, respectively. For mixture toxicity prediction, one important challenge is to clarify whether to group neuroactive substances based on similar mechanisms of action, e.g., same molecular target or rather similar toxicological response, e.g., hyper- or hypoactivity (effect direction). We addressed this by using the spontaneous tail coiling (STC) of zebrafish embryos, which represents the earliest observable motor activity in the developing neural network, as a model to elucidate the link between the mechanism of action and toxicological response. Our objective was to answer the following two questions: (1) Can the mixture models CA or IA be used to predict combined effects for neuroactive chemical mixtures when the components share a similar mode of action (i.e., hyper- or hypoactivity) but show different mechanism of action? (2) Will a mixture of chemicals where the components show opposing effect directions result in an antagonistic combined effect? Results indicate that mixture toxicity of chemicals such as propafenone and abamectin as well as chlorpyrifos and hexaconazole that are known to show different mechanisms of action but similar effect directions were predictable using CA and IA models. This could be interpreted with the convergence of effects on the neural level leading to either a collective activation or inhibition of synapses. We also found antagonistic effects for mixtures containing substances with opposing effect direction. Finally, we discuss how the STC may be used to amend risk assessment.

The impact of locomotion on the brain evolution of squirrels and close relatives

How do brain size and proportions relate to ecology and evolutionary history? Here, we use virtual endocasts from 38 extinct and extant rodent species spanning 50+ million years of evolution to assess the impact of locomotion, body mass, and phylogeny on the size of the brain, olfactory bulbs, petrosal lobules, and neocortex. We find that body mass and phylogeny are highly correlated with relative brain and brain component size, and that locomotion strongly influences brain, petrosal lobule, and neocortical sizes. Notably, species living in trees have greater relative overall brain, petrosal lobule, and neocortical sizes compared to other locomotor categories, especially fossorial taxa. Across millions of years of Eocene-Recent environmental change, arboreality played a major role in the early evolution of squirrels and closely related aplodontiids, promoting the expansion of the neocortex and petrosal lobules. Fossoriality in aplodontiids had an opposing effect by reducing the need for large brains.

Assessing Combined Effects for Mixtures of Similar and Dissimilar Acting Neuroactive Substances on Zebrafish Embryo Movement

Risk assessment of chemicals is usually conducted for individual chemicals whereas mixtures of chemical are occurring in the environment. Considering that neuroactive chemicals are a group of contaminants that dominate in the environment, it is then imperative to understand the combined effects from mixtures. The commonly used models to predict mixture effects, namely concentration addition (CA) and independent action (IA), are thought suitable for mixtures of similarly or dissimilarly acting components, respectively. For mixture toxicity prediction, one important challenge is to clarify whether to group neuroactive substances based on similar mechanisms of action, e.g. same molecular target or rather similar toxicological response, e.g. hyper- or hypoactivity (effect direction). We addressed this by using the spontaneous tail coiling (STC) of zebrafish embryos, which represents the earliest observable motor activity in the developing neural network, as a model to elucidate the link between mechanism of action and toxicological response. Two questions were asked: 1.) Can the mixture models CA or IA be used to predict combined effects for neuroactive chemical mixtures when the components share a similar mode of action (i.e. hyper- or hypoativity) but show different mechanism of action? 2.) Will a mixture of chemicals where the components show opposing effect directions result in an antagonistic combined effect? Results indicate that mixture toxicity of chemicals such as propafenone and abamectin as well as chlorpyrifos and hexaconazole that are known to show different mechanisms of action but similar effect directions were predictable using CA and IA models. This could be interpreted with the convergence of effects on the neural level leading to either a collective activation or inhibition of synapses. We also found antagonistic effects for mixtures containing substances with opposing effect direction. Finally, we discuss how the STC may be used to amend risk assessment.

Effects of weather and season on human brain volume

We present an exploratory cross-sectional analysis of the effect of season and weather on Freesurfer-derived brain volumes from a sample of 3,279 healthy individuals collected on two MRI scanners in Hartford, CT, USA over a 15 year period. Weather and seasonal effects were analyzed using a single linear regression model with age, sex, motion, scan sequence, time-of-day, month of the year, and the deviation from average barometric pressure, air temperature, and humidity, as covariates. FDR correction for multiple comparisons was applied to groups of non-overlapping ROIs. Significant negative relationships were found between the left- and right- cerebellum cortex and pressure (t = -2.25, p = 0.049; t = -2.771, p = 0.017). Significant positive relationships were found between left- and right- cerebellum cortex and white matter between the comparisons of January/June and January/September. Significant negative relationships were found between several subcortical ROIs for the summer months compared to January. An opposing effect was observed between the supra- and infra-tentorium, with opposite effect directions in winter and summer. Cohen’s d effect sizes from monthly comparisons were similar to those reported in recent psychiatric big-data publications, raising the possibility that seasonal changes and weather may be confounds in large cohort studies. Additionally, changes in brain volume due to natural environmental variation have not been reported before and may have implications for weather-related and seasonal ailments.