Elevated levels of mitochondrial CoQ10 induce ROS-mediated apoptosis in pancreatic cancer.

Reactive oxygen species (ROS) are implicated in triggering cell signalling events and pathways to promote and maintain tumorigenicity. Chemotherapy and radiation can induce ROS to elicit cell death allows for targeting ROS pathways for effective anti-cancer therapeutics. Coenzyme Q10 is a critical cofactor in the electron transport chain with complex biological functions that extend beyond mitochondrial respiration. This study demonstrates that delivery of oxidized Coenzyme Q10 (ubidecarenone) to increase mitochondrial Q-pool is associated with an increase in ROS generation, effectuating anti-cancer effects in a pancreatic cancer model. Consequent activation of cell death was observed in vitro in pancreatic cancer cells, and both human patient-derived organoids and tumour xenografts. The study is a first to demonstrate the effectiveness of oxidized ubidecarenone in targeting mitochondrial function resulting in an anti-cancer effect. Furthermore, these findings support the clinical development of proprietary formulation, BPM31510, for treatment of cancers with high ROS burden with potential sensitivity to ubidecarenone.

Identification of a synergistic interaction between endothelial cells and retinal pigment epithelium.

The retinal pigment epithelium located between the neurosensory retina and the choroidal vasculature is critical for the function and maintenance of both the photoreceptors and underlying capillary endothelium. While the trophic role of retinal pigment epithelium on choroidal endothelial cells is well recognized, the existence of a reciprocal regulatory function of endothelial cells on retinal pigment epithelium cells remained to be fully characterized. Using a physiological long-term co-culture system, we determined the effect of retinal pigment epithelium-endothelial cell heterotypic interactions on cell survival, behaviour and matrix deposition. Human retinal pigment epithelium and endothelial cells were cultured on opposite sides of polyester transwells for up to 4 weeks in low serum conditions. Cell viability was quantified using a trypan blue assay. Cellular morphology was evaluated by H&E staining, S.E.M. and immunohistochemistry. Retinal pigment epithelium phagocytic function was examined using a fluorescent bead assay. Gene expression analysis was performed on both retinal pigment epithelium and endothelial cells by quantitative PCR. Quantification of extracellular matrix deposition was performed on decellularized transwells stained for collagen IV, fibronectin and fibrillin. Our results showed that presence of endothelial cells significantly improves retinal pigment epithelium maturation and function as indicated by the induction of visual cycle-associated genes, accumulation of a Bruch's membrane-like matrix and increase in retinal pigment epithelium phagocytic activity. Co-culture conditions led to increased expression of anti-angiogenic growth factors and receptors in both retinal pigment epithelium and endothelial cells compared to monoculture. Tube-formation assays confirmed that co-culture with retinal pigment epithelium significantly decreased the angiogenic phenotype of endothelial cells. These findings provide evidence of critical interdependent interactions between retinal pigment epithelium and endothelial cell involved in the maintenance of retinal homeostasis.

Morpholino-mediated Knockdown of DUX4 Toward Facioscapulohumeral Muscular Dystrophy Therapeutics.

Derepression of DUX4 in skeletal muscle has emerged as a likely cause of pathology in facioscapulohumeral muscular dystrophy (FSHD). Here we report on the use of antisense phosphorodiamidate morpholino oligonucleotides to suppress DUX4 expression and function in FSHD myotubes and xenografts. The most effective was phosphorodiamidate morpholino oligonucleotide FM10, which targets the polyadenylation signal of DUX4. FM10 had no significant cell toxicity, and RNA-seq analyses of FSHD and control myotubes revealed that FM10 down-regulated many transcriptional targets of DUX4, without overt off-target effects. Electroporation of FM10 into FSHD patient muscle xenografts in mice also down-regulated DUX4 and DUX4 targets. These findings demonstrate the potential of antisense phosphorodiamidate morpholino oligonucleotides as an FSHD therapeutic option.

PGC-1α Induces Human RPE Oxidative Metabolism and Antioxidant Capacity.

PURPOSE: Oxidative stress and metabolic dysregulation of the RPE have been implicated in AMD; however, the molecular regulation of RPE metabolism remains unclear. The transcriptional coactivator, peroxisome proliferator-activated receptor-gamma coactivator 1α (PGC-1α) is a powerful mediator of mitochondrial function. This study examines the ability of PGC-1α to regulate RPE metabolic program and oxidative stress response. METHODS: Primary human fetal RPE (hfRPE) and ARPE-19 were matured in vitro using standard culture conditions. Mitochondrial mass of RPE was measured using MitoTracker staining and citrate synthase activity. Expression of PGC-1 isoforms, RPE-specific genes, oxidative metabolism proteins, and antioxidant enzymes was analyzed by quantitative PCR and Western blot. Mitochondrial respiration and fatty-acid oxidation were monitored using the Seahorse extracellular flux analyzer. Expression of PGC-1α was increased using adenoviral delivery. ARPE-19 were exposed to hydrogen peroxide to induce oxidative stress. Reactive oxygen species were measured by CM-H2DCFDA fluorescence. Cell death was analyzed by LDH release. RESULTS: Maturation of ARPE-19 and hfRPE was associated with significant increase in mitochondrial mass, expression of oxidative phosphorylation (OXPHOS) genes, and PGC-1α gene expression. Overexpression of PGC-1α increased expression of OXPHOS and fatty-acid ß-oxidation genes, ultimately leading to the potent induction of mitochondrial respiration and fatty-acid oxidation. PGC-1α gain of function also strongly induced numerous antioxidant genes and, importantly, protected RPE from oxidant-mediated cell death without altering RPE functions. CONCLUSIONS: This study provides important insights into the metabolic changes associated with RPE functional maturation and identifies PGC-1α as a potent driver of RPE mitochondrial function and antioxidant capacity.

Fatty acid binding protein 4 deficiency protects against oxygen-induced retinopathy in mice.

Retinopathy of prematurity (ROP) is a leading cause of blindness in children worldwide due to increasing survival rates of premature infants. Initial suppression, followed by increased production of the retinal vascular endothelial growth factor-A (VEGF) expression are key events that trigger the pathological neovascularization in ROP. Fatty acid binding protein 4 (FABP4) is an intracellular lipid chaperone that is induced by VEGF in a subset of endothelial cells. FABP4 exhibits a pro-angiogenic function in cultured endothelial cells and in airway microvasculature, but whether it plays a role in modulation of retinal angiogenesis is not known. We hypothesized that FABP4 deficiency could ameliorate pathological retinal vascularization and investigated this hypothesis using a well-characterized mouse model of oxygen-induced retinopathy (OIR). We found that FABP4 was not expressed in retinal vessels, but was present in resident macrophages/microglial cells and endothelial cells of the hyaloid vasculature in the immature retina. While FABP4 expression was not required for normal development of retinal vessels, FABP4 expression was upregulated and localized to neovascular tufts in OIR. FABP4-/- mice demonstrated a significant decrease in neovessel formation as well as a significant improvement in physiological revascularization of the avascular retinal tissues. These alterations in retinal vasculature were accompanied by reduced endothelial cell proliferation, but no effect on apoptosis or macrophage/microglia recruitment. FABP4-/- OIR samples demonstrated decreased expression of genes involved in angiogenesis, such as Placental Growth Factor, and angiopoietin 2. Collectively, our findings suggest FABP4 as a potential target of pathologic retinal angiogenesis in proliferative retinopathies.

Direct effect of sodium iodate on neurosensory retina.

PURPOSE: To systematically characterize the effects of NaIO3 on retinal morphology and function. METHODS: NaIO3 at 10, 20, or 30 mg/kg was administered by retro-orbital injection into adult C57BL/6J mice. Phenotypic and functional changes of the retina were assessed at 1, 3, 5, and 8 days postinjection by fundus imaging, optical coherence tomography (OCT), ERG, and histology. Direct NaIO3 cytotoxicity on ARPE-19 and 661W cells was quantified using lactate dehydrogenase (LDH) apoptosis assay. Effect of NaIO3 on RPE and photoreceptor gene expression was assessed in vitro and in vivo by quantitative PCR. RESULTS: While little to no change was observed in the 10 mg/kg NaIO3-injected group, significant retinal anomalies, such as RPE atrophy and retinal thinning, were observed in both 20 and 30 mg/kg NaIO3-injected groups. Gene expression analysis showed rapid downregulation of RPE-specific genes, increase in heme oxygenase 1 expression, and induction of the ratio of Bax to Bcl-2. Electroretinographic response loss and photoreceptor gene repression preceded gross morphological changes. High NaIO3 toxicity on 661W cells was observed in vitro along with reactive oxygen species (ROS) induction. NaIO3 treatment also disrupted oxidative stress, phototransduction, and apoptosis gene expression in 661W cells. Exposure of ARPE-19 cells to NaIO3 increased expression of neurotrophins and protected photoreceptors from direct NaIO3 cytotoxicity. CONCLUSIONS: Systematic characterization of changes associated with NaIO3 injection revealed a large variability in the severity of toxicity induced. Treatment with >20 mg/kg NaIO3 induced visual dysfunction associated with rapid suppression of phototransduction genes and induced oxidative stress in photoreceptors. These results suggest that NaIO3 can directly alter photoreceptor function and survival.

Online versus Live Delivery of Education to Pharmacists in a Large Multicentre Health Region: A Non-inferiority Assessment of Learning Outcomes.

BACKGROUND: The prevalence of online modules for continuing education in the health professions has been increasing in recent years. However, the effectiveness of online modules for pharmacist learning has not been thoroughly studied. OBJECTIVES: The primary aim of this study was to determine if providing education to pharmacists through a self-paced enhanced online module was non-inferior to a face-to-face learning module with respect to knowledge application on the topic of postoperative insulin dosing. Secondary aims were to determine pharmacists' knowledge gain and retention, as well as their satisfaction with the modules. METHODS: The participants in this prospective, randomized, parallel-group non-inferiority trial were pharmacists in a large multicentre health region. Outcomes were measured by comparing scores obtained on pre- and post-module knowledge-assessment questionnaires. A between-group difference in change on knowledge application scores of less than 25 percentage points was the predetermined non-inferiority margin. RESULTS: A total of 74 pharmacists consented to participate, 38 randomly assigned to use the enhanced online module and 36 to attend the face-to-face learning session. For questions examining knowledge application, the mean improvement achieved by the online learning group was 26 percentage points greater than that achieved by the face-to-face learning group (95% confidence interval [CI] 25 to 27; p < 0.001). For questions testing knowledge gain, the improvement achieved by the online learning group was 7 percentage points less than that achieved by the face-to-face learning group (95% CI 2 to 12; p = 0.008). Therefore, the enhanced online module was deemed to be non-inferior to the face-to-face learning session in terms of knowledge application and knowledge gain. Insufficient data were available to analyze the secondary outcome of knowledge retention over time. Participant satisfaction was similar for the 2 groups (p = 0.62). CONCLUSION: The self-paced enhanced online module was non-inferior to facilitated face-to-face learning in terms of improving application and knowledge of insulin dosing. Pharmacists had similar levels of satisfaction with the 2 modes of learning.

CONTEXTE: La prévalence des modules d'apprentissage en ligne pour la formation continue des professionnels de la santé a augmenté ces dernières années. Cependant, l'efficacité de ces modules pour l'apprentissage des pharmaciens n'a pas fait l'objet d'études rigoureuses. OBJECTIFS: Le principal objectif de cette étude était de déterminer si la formation offerte aux pharmaciens au moyen d'un module d'autoapprentissage en ligne amélioré était non inférieure à un module d'apprentissage en personne pour ce qui est de l'application des connaissances sur le sujet de la détermination des doses d'insuline postopératoires. Les objectifs secondaires étaient de mesurer l'acquisition et la rétention des connaissances par les pharmaciens et leur satisfaction par rapport à l'apprentissage. MÉTHODES: Les participants à cette étude prospective de non-infériorité à répartition aléatoire et groupes parallèles étaient des pharmaciens d'une importante régie régionale de la santé multicentre. Les résultats ont été mesurés en comparant les scores obtenus aux questionnaires d'évaluation des connaissances pré- et post-formation. Une différence intergroupe du changement des scores de l'application des connaissances de moins de 25 points de pourcentage constituait la marge de non-infériorité prédéterminée. RÉSULTATS: En tout, 74 pharmaciens ont consenti à participer à l'étude, dont 38 ont été répartis de façon aléatoire dans le groupe module d'apprentissage en ligne amélioré et les 36 autres, dans le groupe séance d'apprentissage en personne. Pour les questions examinant l'application des connaissances, l'amélioration moyenne obtenue dans le groupe apprentissage en ligne était supérieure de 26 points de pourcentage à celle obtenue dans le groupe apprentissage en personne (intervalle de confiance [IC] à 95 %, 25 à 27; p < 0,001). Pour les questions testant l'acquisition de connaissances, l'amélioration obtenue dans le groupe apprentissage en ligne était inférieure de 7 points de pourcentage à celle obtenue dans le groupe apprentissage en personne (IC à 95 %, 2 à 12; p = 0,008). Par conséquent, le module d'apprentissage en ligne amélioré a été jugé non inférieur à la séance d'apprentissage en personne pour ce qui est de l'application des connaissances et de l'acquisition des connaissances. L'insuffisance des données n'a pas permis d'analyser le résultat secondaire relatif à la rétention des connaissances au fil du temps. La satisfaction des participants était similaire entre les deux groupes (p = 0,62). CONCLUSION: Le module d'autoapprentissage en ligne amélioré était non inférieur à une séance d'apprentissage en personne au chapitre des connaissances et de leur application pour déterminer les doses d'insuline postopératoires. Les niveaux de satisfaction des pharmaciens étaient similaires entre les deux méthodes d'apprentissage. [Traduction par l'éditeur].

Small molecule inhibition of cytoskeletal dynamics in melanoma tumors results in altered transcriptional expression patterns of key genes involved in tumor initiation and progression.

BACKGROUND: Rho kinase signaling plays an important role in the oncogenic process largely through its regulation of F-actin dynamics, and inhibition of this pathway results in reduction in tumor volume and metastasis across a number of tumor types. While the cytoskeletal-regulatory role of Rho kinase has been a topic of in-depth study, the mechanisms linking Rho kinase to altered gene expression are largely unknown. MATERIALS AND METHODS: Global gene expression analysis was performed on melanoma tumors treated with sham or the small molecule inhibitor Y27632. RESULTS: Inhibition of Rho kinase activity in melanoma tumors results in a statistically significant change in gene transcription of 94 genes, many of which are critically involved in tumor initiation and progression. CONCLUSION: In addition to regulating tumorigenesis through modulation of the phosphoproteome, Rho kinase signaling also contributes to the regulation of the tumor transcriptome.

Pharmacological inhibition of Rho-kinase (ROCK) signaling enhances cisplatin resistance in neuroblastoma cells.

The role of the RhoA/Rho kinase (ROCK) signaling pathway in cell survival remains a very controversial issue, with its activation being pro-apoptotic in many cell types and anti-apoptotic in others. To test if ROCK inhibition contributes to tumor cell survival or death following chemotherapy, we treated cisplatin damaged neuroblastoma cells with a pharmacological ROCK inhibitor (Y27632) or sham, and monitored cell survival, accumulation of a chemoresistant phenotype, and in vivo tumor formation. Additionally, we assayed if ROCK inhibition altered the expression of genes known to be involved in cisplatin resistance. Our studies indicate that ROCK inhibition results in increased cell survival, acquired chemoresistance, and enhanced tumor survival following cisplatin cytotoxicity, due in part to altered expression of cisplatin resistance genes. These findings suggest that ROCK inhibition in combination with cisplatin chemotherapy may lead to enhanced tumor chemoresistance in neuroblastoma.