70 research outputs found

    Cell-Cell Death Communication by Signals Passing Through Non-Aqueous Environments: A Reply

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    The effects of the emission of low intensity light from cells and organelles, known as biophotons, or ultraweak photon emission, are not well understood and subject to debate. Potapovich & Kostyuk recently proposed that the induction of oxidative stress generates non-chemical death signals which can induce cell death in neighbouring, chemically isolated cells (termed detector cells). Given the significance of these results, here we attempt to replicate their findings. We found treatment of “inductor cells” with duroquinone dissolved in ethanol does indeed induce significant cell death in neighbouring “detector” cells relative to distant control cells (64.53% ± 14.42 vs 99.72% ± 6.09 cell viability), closely reproducing their original results. However, this was no longer true if the induction drug was dissolved in a less volatile solvent, suggesting that their original findings may have been a result of volatile solvent-based transmission as opposed to light-based non-chemical signalling

    Non-chemical Signalling Between Mitochondria

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    A wide variety of studies have reported some form of non-chemical or non-aqueous communication between physically isolated organisms, eliciting changes in cellular proliferation, morphology, and/or metabolism. The sources and mechanisms of such signalling pathways are still unknown, but have been postulated to involve vibration, volatile transmission, or light through the phenomenon of ultraweak photon emission. Here, we report non-chemical communication between isolated mitochondria from MCF7 (cancer) and MCF10A (non-cancer) cell lines. We found that mitochondria in one cuvette stressed by an electron transport chain inhibitor, antimycin, alters the respiration of mitochondria in an adjacent, but chemically and physically separate cuvette, significantly decreasing the rate of oxygen consumption compared to a control (p = <0.0001 in MCF7 and MCF10A mitochondria). Moreover, the changes in O2-consumption were dependent on the origin of mitochondria (cancer vs non-cancer) as well as the presence of "ambient" light. Our results support the existence of non-chemical signalling between isolated mitochondria. The experimental design suggests that the non-chemical communication is light-based, although further work is needed to fully elucidate its nature

    Cystic fibrosis co-existing with trisomy 21

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    AbstractPrevious reports of children with co-existence of cystic fibrosis and full trisomy 21 suggest a very poor prognosis, with the majority of cases dying in infancy and the oldest reported survivor being 6years of age. We report the case of a young man with genetically confirmed trisomy 21 and homozygous for the F508del cystic fibrosis mutation. Despite the diagnosis of cystic fibrosis being delayed until the age of 2years he has transitioned to adult services and is now 25years of age. Currently he has poor lung function and a continuous ambulatory oxygen requirement

    Cannabidiol modulates mitochondrial redox and dynamics in MCF7 cancer cells: a study using fluorescence lifetime imaging microscopy of NAD(P)H

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    The cannabinoid, cannabidiol (CBD), is part of the plant's natural defence system that when given to animals has many useful medicinal properties, including activity against cancer cells, modulation of the immune system, and efficacy in epilepsy. Although there is no consensus on its precise mode of action as it affects many cellular targets, CBD does appear to influence mitochondrial function. This would suggest that there is a cross-kingdom ability to modulate stress resistance systems that enhance homeostasis. As NAD(P)H autofluorescence can be used as both a metabolic sensor and mitochondrial imaging modality, we assessed the potential of this technique to study the in vitro effects of CBD using 2-photon excitation and fluorescence lifetime imaging microscopy (2P-FLIM) of NAD(P)H against more traditional markers of mitochondrial morphology and cellular stress in MCF7 breast cancer cells. 2P-FLIM analysis revealed that the addition of CBD induced a dose-dependent decrease in bound NAD(P)H, with 20 µM treatments significantly decreasing the contribution of bound NAD(P)H by 14.6% relative to control (p<0.001). CBD also increased mitochondrial concentrations of reactive oxygen species (ROS) (160 ± 53 vs. 97.6 ± 4.8%, 20 µM CBD vs. control, respectively, p<0.001) and Ca2+ (187 ± 78 vs. 105 ± 10%, 20 µM CBD vs. control, respectively, p<0.001); this was associated with significantly decreased mitochondrial branch length and increased fission. These are all suggestive of mitochondrial stress. Our results support the use of NAD(P)H autofluorescence as an investigative tool and provide further evidence that CBD can modulate mitochondrial function and morphology in a dose dependent manner, with clear evidence of it inducing oxidative stress at higher concentrations. This continues to support emerging data in the literature and may provide further insight into its overall mode of action, not only in cancer, but potentially its function in the plant and why it can act as a medicine

    Acetate induces growth arrest in colon cancer cells through modulation of mitochondrial function

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    Acetate is one of the main short chain fatty acids produced in the colon when fermentable carbohydrates are digested. It has been shown to affect normal metabolism, modulating mitochondrial function and fatty acid oxidation. Currently, there is no clear consensus regarding the effects of acetate on tumorigenesis and cancer metabolism. Here, we investigate the metabolic effects of acetate on colon cancer. HT29 and HCT116 colon cancer cell lines were treated with acetate and its effect on mitochondrial proliferation, reactive oxygen species, density, permeability transition pore, cellular bioenergetics, gene expression of acetyl-CoA synthetase 1 (ACSS1) and 2 (ACSS2) and lipid levels were investigated. Acetate was found to reduce proliferation of both cell lines under normoxia as well as reducing glycolysis; it was also found to increase both oxygen consumption and ROS levels. Cell death observed was independent of ACSS1/2 expression. Under hypoxic conditions, reduced proliferation was maintained in the HT29 cell line but no longer observed in the HCT116 cell line. ACSS2 expression together with cellular lipid levels was increased in both cell lines under hypoxia which may partly protect cells from the anti-proliferative effects of reversed Warburg effect caused by acetate. The findings from this study suggest that effect of acetate on proliferation is a consequence of its impact on mitochondrial metabolism and during normoxia is independent of ACCS1/2 expression

    Cannabidiol Affects Extracellular Vesicle Release, miR21 and miR126, and Reduces Prohibitin Protein in Glioblastoma Multiforme Cells

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    Glioblastoma multiforme (GBM) is the most common and aggressive form of primary malignant brain tumor in adults, with poor prognosis. Extracellular vesicles (EVs) are key-mediators for cellular communication through transfer of proteins and genetic material. Cancers, such as GBM, use EV release for drug-efflux, pro-oncogenic signaling, invasion and immunosuppression; thus the modulation of EV release and cargo is of considerable clinical relevance. As EV-inhibitors have been shown to increase sensitivity of cancer cells to chemotherapy, and we recently showed that cannabidiol (CBD) is such an EV-modulator, we investigated whether CBD affects EV profile in GBM cells in the presence and absence of temozolomide (TMZ). Compared to controls, CBD-treated cells released EVs containing lower levels of pro-oncogenic miR21 and increased levels of anti-oncogenic miR126; these effects were greater than with TMZ alone. In addition, prohibitin (PHB), a multifunctional protein with mitochondrial protective properties and chemoresistant functions, was reduced in GBM cells following 1 h CBD treatment. This data suggests that CBD may, via modulation of EVs and PHB, act as an adjunct to enhance treatment efficacy in GBM, supporting evidence for efficacy of cannabinoids in GBM

    The longitudinal impact of diet, physical activity, sleep, and screen time on Canadian adolescents' academic achievement: An analysis from the COMPASS study

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    The final publication is available at Elsevier via https://doi.org/10.1016/j.ypmed.2019.05.007. © 2019. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/Adequate amounts of physical activity, sleep, and screen time along with a healthy diet have been demonstrated to have positive associations with academic achievement. No longitudinal study has investigated the simultaneous relationship between all of these behaviours and academic achievement. Data from 11,016 adolescent participants of the COMPASS study in Alberta and Ontario were analysed. Students self-reported their adherence to Canadian recommendations for health behaviours and academic achievement in Math and English on school-based surveys administered in the 2015/16 and 2016/17 waves of COMPASS. Multinomial generalized estimating equations were used to evaluate the association between longitudinal changes in adherence to recommendations and academic achievement at follow-up. Models were adjusted for self-reported sociodemographic information, body weight status, and baseline academic achievement. Students who adhered to a greater number of recommendations performed better than students who adhered to fewer recommendations. Meeting recommendations for Meat and Alternatives (protein-rich foods) and screen time were consistently associated with higher academic achievement compared to students who did not meet these recommendations. A change from not meeting recommendations for Vegetables and Fruit to meeting the recommendation in the following year was associated with higher achievement in both subjects. There was no association between sleep behaviours or physical activity and academic achievement. Results indicate that adherence to recommendations for protein-rich foods, screen time, and vegetables and fruit show promise as behavioural targets for higher academic achievement among youth. Further study using objectives measurements of behaviours and further consideration of socioeconomic variables is merited.The COMPASS study was supported by a bridge grant from the Canadian Institutes of Health Research (CIHR) Institute of Nutrition, Metabolism and Diabetes through the “Obesity – Interventions to Prevent or Treat” priority funding awards (OOP-110788; grant awarded to S. Leatherdale) and an operating grant from the CIHR Institute of Population and Public Health (IPPH) (MOP-114875; grant awarded to S. Leatherdale). Dr. Faught was supported by a Libin Cardiovascular Institute/Cumming School of Medicine Post-Doctoral Fellowship award. Drs. Faulkner and Leatherdale are Chairs in Applied Public Health Research funded by the Public Health Agency of Canada (PHAC) in partnership with Canadian Institutes of Health Research (CIHR). Dr. Storey is supported as a Distinguished Researcher, Stollery Science Lab, Stollery Children's Hospital Foundation and is also a Member of the Women and Children's Health Research Institute. Dr. Carson is supported by a CIHR New Investigator Salary Award

    Cannabidiol (CBD) is a Novel Inhibitor for Exosome and Microvesicle (EMV) Release in Cancer

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    Exosomes and microvesicles (EMV) are lipid bilayer-enclosed structures, released by cells and involved in intercellular communication through transfer of proteins and genetic material. EMV release is also associated with various pathologies, including cancer, where increased EMV release is amongst other associated with chemo-resistance and active transfer of pro-oncogenic factors. Recent studies show that EMV-inhibiting agents can sensitise cancer cells to chemotherapeutic agents and reduce cancer growth in vivo. Cannabidiol (CBD), a phytocannabinoid derived from Cannabis sativa, has anti-inflammatory and anti-oxidant properties, and displays anti-proliferative activity. Here we report a novel role for CBD as a potent inhibitor of EMV release from three cancer cell lines: prostate cancer (PC3), hepatocellular carcinoma (HEPG2) and breast adenocarcinoma (MDA-MB-231). CBD significantly reduced exosome release in all three cancer cell lines, and also significantly, albeit more variably, inhibited microvesicle release. The EMV modulating effects of CBD were found to be dose dependent (1 and 5 μM) and cancer cell type specific. Moreover, we provide evidence that this may be associated with changes in mitochondrial function, including modulation of STAT3 and prohibitin expression, and that CBD can be used to sensitise cancer cells to chemotherapy. We suggest that the known anti-cancer effects of CBD may partly be due to the regulatory effects on EMV biogenesis, and thus CBD poses as a novel and safe modulator of EMV-mediated pathological events

    Heimler Syndrome is Caused by Hypomorphic Mutations in the Peroxisome-Biogenesis Genes PEX1 and PEX6

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    Heimler syndrome (HS) is a rare recessive disorder characterized by sensorineural hearing loss (SNHL), amelogenesis imperfecta, nail abnormalities and occasional or late onset retinal pigmentation. We ascertained eight families with HS, and - using a whole exome sequencing approach - identified biallelic mutations in PEX1 or PEX6 in six of them. Loss of function mutations in both genes are known causes of a spectrum of autosomal recessive peroxisome biogenesis disorders (PBDs), including Zellweger syndrome. PBDs are characterized by leukodystrophy, hypotonia, SNHL, retinopathy, and skeletal, craniofacial, and liver abnormalities. We demonstrate that each HS family has at least one hypomorphic allele that results in extremely mild peroxisomal dysfunction. Although individuals with HS share some subtle clinical features found in PBDs, the overlap is minimal and the diagnosis was not suggested by routine blood and skin fibroblast analyses used to detect PBDs. In conclusion, our findings define Heimler syndrome as a mild PBD, expanding the pleiotropy of mutations in PEX1 and PEX6
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