ALBERT

Description: Neonatal liver-derived rat epithelial cells (rLEC) from biliary origin are liver progenitor cells that acquire a hepatocyte-like phenotype upon sequential exposure to hepatogenic growth factors and cytokines. Undifferentiated rLEC express several liver-enriched transcription factors, including the hepatocyte nuclear factors (HNF) 3β and HNF6, but not the hepatic master regulator HNF4α. In this study, we first investigated the impact of the ectopic expression of HNF4α in rLEC on both mRNA and microRNA (miR) level by means of microarray technology. We found that HNF4α transduction did not induce major changes to the rLEC phenotype. However, we next investigated the influence of DNA methyl transferase (DNMT) inhibition on the phenotype of undifferentiated naïve rLEC by exposure to 5' azacytidine (AZA), which was found to have a significant impact on rLEC gene expression. The transduction of HNF4α or AZA treatment resulted both in significantly downregulated C/EBPα expression levels, while the exposure of the cells to AZA had a significant effect on the expression of HNF3β. Computationally, dysregulated miRNAs were linked to target mRNAs using the microRNA Target Filter function of Ingenuity Pathway Analysis. We found that differentially regulated miRNA–mRNA target associations predict ectopic HNF4α expression in naïve rLEC to interfere with cell viability and cellular maturation (miR-19b-3p/NR4A2, miR30C-5p/P4HA2, miR328-3p/CD44) while it predicts AZA exposure to modulate epithelial/hepatic cell proliferation, apoptosis, cell cycle progression and the differentiation of stem cells (miR-18a-5p/ESR1, miR-503-5p/CCND1). Finally, our computational analysis predicts that the combination of HNF4α transduction with subsequent AZA treatment might cause changes in hepatic cell proliferation and maturation (miR-18a-5p/ESR1, miR-503-5p/CCND1, miR-328-3p/CD44) as well as the apoptosis (miR-16-5p/BCL2, miR-17-5p/BCL2, miR-34a-5p/BCL2 and miR-494-3p/HMOX1) of naïve rLEC.

Description: Methacrylated hyaluronic acid (MeHA) and chondroitin sulfate (CS)-biofunctionalized MeHA (CS-MeHA), were crosslinked in the presence of a matrix metalloproteinase 7 (MMP7)-sensitive peptide. The synthesized hydrogels were embedded with either human mesenchymal stem cells (hMSCs) or chondrocytes, at low concentrations, and subsequently cultured in a stem cell medium (SCM) or chondrogenic induction medium (CiM). The pivotal role of the synthesized hydrogels in promoting the expression of cartilage-related genes and the formation of neocartilage tissue despite the low concentration of encapsulated cells was assessed. It was found that hMSC-laden MeHA hydrogels cultured in an expansion medium exhibited a significant increase in the expression of chondrogenic markers compared to hMSCs cultured on a tissue culture polystyrene plate (TCPS). This favorable outcome was further enhanced for hMSC-laden CS-MeHA hydrogels, indicating the positive effect of the glycosaminoglycan binding peptide on the differentiation of hMSCs towards a chondrogenic phenotype. However, it was shown that an induction medium is necessary to achieve full span chondrogenesis. Finally, the histological analysis of chondrocyte-laden MeHA hydrogels cultured on an ex vivo osteochondral platform revealed the deposition of glycosaminoglycans (GAGs) and the arrangement of chondrocyte clusters in isogenous groups, which is characteristic of hyaline cartilage morphology.

Description: The progression of mesenchymal stem cell-based therapy from concept to cure closely depends on the optimization of conditions that allow a better survival and favor the cells to achieve efficient liver regeneration. We have previously demonstrated that adult-derived human liver stem/progenitor cells (ADHLSC) display significant features that support their clinical development. The current work aims at studying the impact of a sustained pro-inflammatory environment on the principal biological features of ADHLSC in vitro. METHODS: ADHLSC from passages 4–7 were exposed to a cocktail of inflammatory cytokines for 24 h and 9 days and subsequently analyzed for their viability, expression, and secretion profiles by using flow cytometry, RT-qPCR, and antibody array assay. The impact of inflammation on the hepatocytic differentiation potential of ADHLSC was also evaluated. RESULTS: ADHLSC treated with a pro-inflammatory cocktail displayed significant decrease of cell yield at both times of treatment while cell mortality was observed at 9 days post-priming. After 24 h, no significant changes in the immuno-phenotype of ADHLSC expression profile could be noticed while after 9 days, the expression profile of relevant markers has changed both in the basal conditions and after inflammation treatment. Inflammation cocktail enhanced the release of IL-6, IL-8, CCL5, monocyte-chemo-attractant protein-2 and 3, CXCL1/GRO, and CXCL5/ENA78. Furthermore, while IP-10 secretion was increased after 24 h priming, granulocyte macrophage colony-stimulating factor enhanced secretion was noticed after 9 days treatment. Finally, priming of ADHLSC did not affect their potential to differentiate into hepatocyte-like cells. CONCLUSION: These results indicate that ADHLSCs are highly sensitive to inflammation and respond to such signals by adjusting their gene and protein expression. Accordingly, monitoring the inflammatory status of patients at the time of cell transplantation, will certainly help in enhancing ADHLSC safety and efficiency.

Description: Human skin-derived precursors (SKP) represent a group of somatic stem/precursor cells that reside in dermal skin throughout life that harbor clinical potential. SKP have a high self-renewal capacity, the ability to differentiate into multiple cell types and low immunogenicity, rendering them key candidates for allogeneic cell-based, off-the-shelf therapy. However, potential clinical application of allogeneic SKP requires that these cells retain their therapeutic properties under all circumstances and, in particular, in the presence of an inflammation state. Therefore, in this study, we investigated the impact of pro-inflammatory stimulation on the secretome and immunosuppressive properties of SKP. We demonstrated that pro-inflammatory stimulation of SKP significantly changes their expression and the secretion profile of chemo/cytokines and growth factors. Most importantly, we observed that pro-inflammatory stimulated SKP were still able to suppress the graft-versus-host response when cotransplanted with human PBMC in severe-combined immune deficient (SCID) mice, albeit to a much lesser extent than unstimulated SKP. Altogether, this study demonstrates that an inflammatory microenvironment has a significant impact on the immunological properties of SKP. These alterations need to be taken into account when developing allogeneic SKP-based therapies.

Description: This paper presents the results of recent work to develop and trial a mine machine radar sensor for underground coal mine vehicles. There is an urgent industry need for an integrated solution to the problem of operating an underground vehicle in conditions of dense ambient dust and/or smoke, such as may occur in underground coal mines after a fire or explosion. Under these conditions, sensors such as cameras and lidar offer limited assistance due to their inability to penetrate thick dust. Thermal infrared can penetrate dust but still results in poor vision, as there is insufficient temperature contrast between the tunnel walls and the ambient air. Microwave radar sensors are able to penetrate the dust, and suitable radar sensors have been developed for use in the automation industry. Adapting such sensors for use in an underground coal mining environment was the focus of this research effort, and involved trialing a suitable sensor in dust and smoke chambers as well as trials in an underground coal mine with introduced dust. Data processing and the development of a suitable user interface were key aspects of the research. Since any sensor would have to operate in an explosive atmosphere, a related research work developed a flameproof dielectric enclosure to allow the use of the radar in the mine environment.

Description: We measured the radiation tolerance of commercially available diamonds grown by the Chemical Vapor Deposition process by measuring the charge created by a 120 GeV hadron beam in a 50 μm pitch strip detector fabricated on each diamond sample before and after irradiation. We irradiated one group of samples with 70 MeV protons, a second group of samples with fast reactor neutrons (defined as energy greater than 0.1 MeV), and a third group of samples with 200 MeV pions, in steps, to (8.8±0.9) × 1015 protons/cm2, (1.43±0.14) × 1016 neutrons/cm2, and (6.5±1.4) × 1014 pions/cm2, respectively. By observing the charge induced due to the separation of electron–hole pairs created by the passage of the hadron beam through each sample, on an event-by-event basis, as a function of irradiation fluence, we conclude all datasets can be described by a first-order damage equation and independently calculate the damage constant for 70 MeV protons, fast reactor neutrons, and 200 MeV pions. We find the damage constant for diamond irradiated with 70 MeV protons to be 1.62±0.07(stat)±0.16(syst)× 10−18 cm2/(p μm), the damage constant for diamond irradiated with fast reactor neutrons to be 2.65±0.13(stat)±0.18(syst)× 10−18 cm2/(n μm), and the damage constant for diamond irradiated with 200 MeV pions to be 2.0±0.2(stat)±0.5(syst)× 10−18 cm2/(π μm). The damage constants from this measurement were analyzed together with our previously published 24 GeV proton irradiation and 800 MeV proton irradiation damage constant data to derive the first comprehensive set of relative damage constants for Chemical Vapor Deposition diamond. We find 70 MeV protons are 2.60 ± 0.29 times more damaging than 24 GeV protons, fast reactor neutrons are 4.3 ± 0.4 times more damaging than 24 GeV protons, and 200 MeV pions are 3.2 ± 0.8 more damaging than 24 GeV protons. We also observe the measured data can be described by a universal damage curve for all proton, neutron, and pion irradiations we performed of Chemical Vapor Deposition diamond. Finally, we confirm the spatial uniformity of the collected charge increases with fluence for polycrystalline Chemical Vapor Deposition diamond, and this effect can also be described by a universal curve.

Description: Injera, an East African leavened sourdough fermented pancake has remarkable textural properties despite being made from non-wheat flours. However, teff flour, which produces the best quality injera, is expensive and limited in availability. The effects of waxy (high amylopectin) and high protein digestibility (HD) traits in sorghum on injera quality were studied. Eight white tan-plant sorghum lines expressing these traits in various combinations and three normal sorghum types were studied, with teff flour as reference. Descriptive sensory profiling of fresh and stored injera revealed that injera from waxy sorghums were softer, spongier, more flexible and rollable compared to injera from normal sorghum and much closer in these important textural attributes to teff injera. Instrumental texture analysis of injera similarly showed that waxy sorghum injera had lower stress and higher strain than injera from normal sorghum. The improved injera textural quality was probably due to the slower retrogradation and better water-holding of amylopectin starch. The HD trait, however, did not clearly affect injera quality, probably because the lines had only moderately higher protein digestibility. In conclusion, waxy sorghum flour has considerable potential for the production of gluten-free sourdough fermented flatbread-type products with good textural functionality.

Description: Reducing greenhouse gas emissions in the transport sector is known to be an important contribution to climate change mitigation. Some parts of the transport sector are particularly difficult to decarbonize; this includes the heavy-duty vehicle sector, which is considered one of the “hard-to-abate” sectors of the economy. Transitioning from diesel trucks to hydrogen fuel cell trucks has been identified as a potential way to decarbonize the sector. However, the current and future costs and efficiencies of the enabling technologies remain unclear. In light of these uncertainties, this paper investigates the investments required to decarbonize New Zealand’s heavy-duty vehicle sector with green hydrogen. By combining system dynamics modelling literature and hydrogen transition modelling literature a customized methodology is developed for modelling hydrogen transitions with system dynamics modelling. Results are presented in terms of the investments required to purchase the hydrogen production capacity and the investments required to supply electricity to the hydrogen production systems. Production capacity investments are found to range between 1.59 and 2.58 billion New Zealand Dollars, and marginal electricity investments are found to range between 4.14 and 7.65 billion New Zealand Dollars. These investments represent scenarios in which 71% to 90% of the heavy-duty vehicle fleet are replaced with fuel cell trucks by 2050. The wide range of these findings reflects the large uncertainties in estimates of how hydrogen technologies will develop over the course of the next thirty years. Policy recommendations are drawn from these results, and a clear opportunity for future work is outlined. Most notably, the results from this study should be compared with research investigating the investments required to decarbonize the heavy-duty vehicle sectors with alternative technologies such as battery-electric trucks, biodiesel, and catenary systems. Such a comparison would ensure that the most cost effective decarbonization strategy is employed.

Description: The composition of human breast milk changes in the first two months of life, adapting itself to the evolving needs of the growing new-born. Lipids in milk are a source of energy, essential fatty acids (FA), fat-soluble vitamins, and vital bioactive components. Information on breast milk FA of Malaysian lactating women is scarce. Based on convenience sampling, a total of 20 Malay breastfeeding women who fulfilled the inclusion criteria were recruited. Breast milk was collected three times from each subject at consecutive intervals of 2–3 weeks apart. A total of 60 breast milk samples were collected and classified into “transitional milk” (n = 8), “early milk” (n = 26) and “mature milk” (n = 26). All milk samples were air freighted to University of Groningen, Netherlands for analysis. The dominant breast milk FA were oleic acid, constituting 33% of total fatty acids, followed by palmitic acid (26%). Both these FA and the essential FA, linoleic acid (10%) and alpha-linolenic acid (0.4%), showed no significant changes from transitional to mature milk. Breast milk ratio of n-6:n-3 polyunsaturated fatty acids (PUFA) was comparatively high, exceeding 10 throughout the lactation period, suggesting a healthier balance of PUFA intake is needed in pregnancy and at postpartum.

Description: Malignant melanoma is the major cause of skin cancer-related deaths. Surgery in combination with radiotherapy, immunotherapy or chemotherapy is used to eradicate cancer cells, however, this treatment option is limited by the tolerance of the surrounding healthy tissue. The extracts from Galenia africana have been shown to possess anti-cancer flavonoid compounds and can be a safer and cost-effective alternative treatment. The study aimed to compare the anti-proliferative effects of G. africana on human skin cells (HaCaT) and human malignant melanoma cells (A375). The cells were exposed to various concentrations of the G. africana extract at different times. In vitro assays were employed to determine cell viability and cytotoxicity. Hoechst 33342 staining was performed to observe the nuclear changes, including apoptosis. G. africana significantly reduced the cell viability of the A375 cells in a dose and time-dependent manner, while having no effect on the HaCaT cells. The A375 cells displayed nuclear condensation, brightly stained nuclei and nuclear fragmentation indicative of apoptosis. This suggests a clinical rationale for the use of G. africana as a potential anti-melanoma agent offering efficacy and low toxicity. This study provides new insights for future work on investigating the utilization of G. africana in malignant melanoma treatment.