Search

Suliman A Alsagaby,1 Rajendran Vijayakumar,2 Mariappan Premanathan,2 Suresh Mickymaray,2 Wael Alturaiki,1 Raid S Al-Baradie,1 Saleh AlGhamdi,3,4 Mohammad A Aziz,4,5 Fahad A Alhumaydhi,6 Faisal A Alzahrani,7 Ameen S Alwashmi,6 Waleed Al Abdulmonem,8 Naif Khalaf Alharbi,4,9 Chris Pepper10 1Department of Medical Laboratory Sciences, College of Applied Medical Sciences, Majmaah University, Majmaah 11932, Saudi Arabia; 2Department of Biology, College of Sciences, Majmaah University, Majmaah 11932, Saudi Arabia; 3Clinical Research Department, Research Center, King Fahad Medical City, Riyadh, Saudi Arabia; 4King Saud Bin Abdulaziz University for Health Sciences, Riyadh 11426, Saudi Arabia; 5Colorectal Cancer Research Program, King Abdullah International Medical Research Center, Riyadh, Saudi Arabia; 6Department of Medical Laboratories, College of Applied Medical Sciences, Qassim University, Buraydah, Kingdom of Saudi Arabia; 7Department of Biochemistry, Faculty of Science, King Abdulaziz University, Jeddah 21589, Saudi Arabia; 8Department of Pathology, College of Medicine, Qassim University, Buraidah, Saudi Arabia; 9Department of Infectious Disease Research, King Abdullah International Medical Research Center, Riyadh, Saudi Arabia; 10Brighton and Sussex Medical School, University of Sussex, Brighton, UKCorrespondence: Suliman A AlsagabyDepartment of Medical Laboratory Sciences, College of Applied Medical Sciences, Majmaah University, PO Box 1712, Majmaah 11932, Saudi ArabiaTel +966 542552749Email s.alsaqaby@mu.edu.saIntroduction: Zinc oxide nanoparticles (ZnO NPs) have recently attracted attention as potential anti-cancer agents. To the best of our knowledge, the toxicity of ZnO NPs against human chronic myeloid leukemia cells (K562 cell line) has not been studied using transcriptomics approach.Objective: The goals of this study were to evaluate the capability of ZnO NPs to induce apoptosis in human chronic myeloid leukemia cells (K562 cells) and to investigate the putative mechanisms of action.Methods: We used viability assay and flowcytometry coupled with Annexin V-FITC and propidium iodide to investigate the toxicity of ZnO NPs on K562 cells and normal peripheral blood mononuclear cells. Next we utilized a DNA microarray-based transcriptomics approach to characterize the ZnO NPs-induced changes in the transcriptome of K562 cells.Results: ZnO NPs exerted a selective toxicity (mainly by apoptosis) on the leukemic cells (p≤ 0.005) and altered their transcriptome; 429 differentially expressed genes (DEGs) with fold change (FC)≥ 4 and p≤ 0.008 with corrected p≤ 0.05 were identified in K562 cells post treatment with ZnO NPs. The over-expressed genes were implicated in “response to zinc”, “response to toxic substance” and “negative regulation of growth” (corrected p≤ 0.05). In contrast, the repressed genes positively regulated “cell proliferation”, “cell migration”, “cell adhesion”, “receptor signaling pathway via JAK-STAT” and “phosphatidylinositol 3-kinase signaling” (corrected p≤ 0.05). Lowering the FC to ≥ 1.5 with p≤ 0.05 and corrected p≤ 0.1 showed that ZnO NPs over-expressed the anti-oxidant defense system, drove K562 cells to undergo mitochondrial-dependent apoptosis, and targeted NF-κB pathway.Conclusion: Taken together, our findings support the earlier studies that reported anti-cancer activity of ZnO NPs and revealed possible molecular mechanisms employed by ZnO NPs to induce apoptosis in K562 cells.Keywords: transcriptomics, ZnO NPs, CML, apoptosis

Litter management is important when rearing meat chickens because litter conditions can affect production as well as chicken health and wellbeing. An industry survey was conducted to gather information from Australian meat chicken growers and integrators about their litter management practices, providing an opportunity to share their knowledge, experiences and perceptions about litter re-use and litter turning. This information was essential for researchers investigating litter management practices because it provided a better understanding about litter preparation and shed configuration to ensure that representative and timely data could be collected. Eighty-four survey responses were received from all major growing regions across Australia. The survey closely reflected the proportions of conventional and free-range production systems of Australian chicken meat industry, with approximately 21% of survey responses representing free range and 80% representing conventional barn housing. Concerning litter management practices, the survey showed that litter re-use is limited (32% of responses), but litter turning is a widespread practice (89% of responses). Litter turning is used to reduce the occurrence of caked litter and to keep litter 'working'. Maintaining 'dry and friable' litter has been shown to reduce the risk of health issues and allows chickens to display behaviours, such as dustbathing, which are believed to be associated with improved welfare. Comments from the survey indicated that litter turning alone does not achieve dry and friable litter, and that proactive ventilation, heater and drinker management are essential. Growers also explained that litter turning is not without its challenges, and can potentially contribute to spikes of dust, ammonia and/or odour. They also expressed concerns relating to operating machinery in poultry houses, particularly when there is high liveweight density. When growers were asked about litter re-use, several reported that it has benefits in reducing production costs and improving moisture holding capacity, but concerns were also expressed about risks relating to ammonia, litter beetle control and disease transmission. Researchers will be able to use these survey results to gain an insight into practices, perceptions, constraints, and challenges relating to the Australian chicken meat industry and ensure that future research relating to litter management reflects local conditions and practices. Litter management is important in meat chicken production because good litter contributes to good productivity, health and wellbeing. Many different practices are used to manage litter, and they can lead to different outcomes. This paper summarises the responses of a survey that allowed growers and integrators in the Australian chicken meat industry to share their litter management practices and experiences. This survey will provide researchers with a deeper understanding of industry practices and conditions and will enable them to tailor their studies to reflect these. [ABSTRACT FROM AUTHOR]