A solar evaporator fabricated from corncob waste for the desalination of seawater and removal of oil/herbicides from contaminated water

Corncob (CC) based solar evaporators were employed to desalinize seawater brought from the Vallarta coast in Mexico. The pure CC produced an evaporation-rate and evaporation-efficiency of 0.63 kg m-2 h-1 and 38.4%, respectively, under natural solar light. Later, the CC was coated with carbonized CC (CCCE evaporator) or was coated with graphene (CCGE evaporator). Those evaporators were used for the desalination of seawater and obtained higher evaporation rates of 1.59-1.67 kg m-2 h-1, and higher evaporation efficiencies of 92-94% (under natural solar light). The desalination experiments were repeated under artificial solar light and the evaporation-rates/evaporation-efficiencies slightly decreased to 1.43-1.52 kg m-2 h-1/88-92%. The surface analysis of the evaporators by FTIR, XPS and Raman revealed that the CCGE evaporator had on its surface a lower content of defects and a higher amount of OH groups than the CCCE evaporator. Therefore, the CCGE evaporator had higher evaporation-rates/evaporation-efficiencies in comparison with the CCCE evaporator. Furthermore, we purified water contaminated with three different herbicides (fomesafen, 2-6 dichlorobenzamide and 4-chlorophenol at 30 ppm) by evaporation and using natural solar light. Interestingly, the CCCE and CCGE evaporators also removed the herbicides by physical adsorption with efficiencies of 12-22.5%. Moreover, the CCGE evaporator removed vegetable oil from contaminated water by adsorption and its maximum adsorption capacity was 1.72 g/g. Overall, our results demonstrated that the corncob-based evaporators studied here are a low-cost alternative to obtain clean water under natural solar light and this one was more effective for the desalination of seawater than the artificial sunlight (Xe lamp).

Using NIR irradiation and magnetic bismuth ferrite microparticles to accelerate the removal of polystyrene microparticles from the drinking water

Magnetic bismuth ferrite (BiFO) microparticles were employed for the first time for the removal of polystyrene (PS) nano/microplastics from the drinking water. BiFO is formed by porous agglomerates with sizes of 5-11 μm, while the PS nano/microparticles have sizes in the range of 70-11000 nm. X-ray diffraction studies demonstrated that the BiFO microparticles are composed of BiFeO3/Bi25FeO40 (the content of Bi25FeO40 is ≈ 8.6%). Drinking water was contaminated with PS nano/microparticles (1 g L-1) and BiFO microparticles were also added to the contaminated water. Later, the mixture of PS-particles + BiFO was irradiated with NIR light (980 nm). Consequently, PS nano/microparticles melted on the BiFO microparticles due to the excessive heating on their surface. At the same time, the NIR (near infrared) light generated oxidizing agents (∙OH and h+), which degraded the by-products formed during the photocatalytic degradation of PS nano/microparticles. Subsequently, the NIR irradiation was stopped, and a Neodymium magnet was utilized to separate the BiFO microparticles from the water. This last procedure also permitted the removal of PS nano/microparticles by physical adsorption. Zeta potential measurements demonstrated that the BiFO surface was positively charged, allowing the removal of the negatively charged PS nano/microparticles by electrostatic attraction. The combination of the photocatalytic process and the physical adsorption permitted a complete removal of PS nano/microparticles after only 90 min as well as a high mineralization of by-products (≈95.5% as confirmed by the total organic carbon measurements). We estimate that ≈23.6% of the PS nano/microparticles were eliminated by photocatalysis and the rest of PS particles (≈76.4%) by physical adsorption. An outstanding adsorption capacity of 195.5 mg g-1 was obtained after the magnetic separation of the BiFO microparticles from the water. Hence, the results of this research demonstrated that using photocatalysis + physical-adsorption is a feasible strategy to quickly remove microplastic contaminants from the water.

Role of Extracellular Vesicles Produced by Stem Cells in Tissue Repair

The purpose of this Special Issue is to emphasize the great potential of the translational applications of extracellular vesicles (EVs) produced by stem cells (mesenchymal stem cells, induced pluripotent stem cells, etc [...].

Novel polypropylene-TiO2:Bi spherical floater for the efficient photocatalytic degradation of the recalcitrant 2,4,6-TCP herbicide

In this work, spherical photocatalytic floaters were fabricated by depositing TiO₂:Bi (TBi) particles on polypropylene (PP) spheres (recycled from beer cans). These particles were deposited on the sphere (TBi-sphere) by the spray coating technique and evaluated their performance for the photocatalytic degradation of 2,4,6-trichlorophenol (2,4,6-TCP) herbicide. SEM images demonstrated that the BTi powders consisted in conglomerated grains with sizes of 20-80 nm and the analysis by X-ray diffraction confirmed the presence of rutile and anatase phases in the BTi. The photocatalytic experiments showed that the TBi and TBi-sphere produced maximum degradation of 90 and 97% for 2,4,6-TCP, respectively, after 4 h under UV-Vis light. The photocatalytic powders/composites were reused 3 times and the loss of degradation efficiency was 3 and 16% for the TBi powder and TBi-sphere, respectively. This means that the TBi-sphere is more stable for the continuous degradation of the 2,4,6-TCP contaminant. The TiO₂:Bi powder was compared with the commercial TiO₂ (P25) and found that the TiO₂:Bi powder had higher light absorption (≈42%) and higher surface area (≈105%) than the P25. Therefore, the degradation percentage for the 2,4,6-TCP was 52% higher in the sample doped with Bi. Also, scavenger experiments were carried out and found that the main oxidizing agents produced for the degradation of 2,4,6-TCP were •OH^- radicals and •O₂^- anions. Other species such as h⁺ were also produced at lower amount. Hence, our results demonstrated that spherical/floatable photocatalytic composites are a viable option to remove herbicide residuals from the water, which is of interest in water-treatment-plants.

Thrombospondin-1 induction and VEGF reduction by proteasome inhibition

The present study focuses on investigating the expression of thrombospondin-1 (TSP-1), a natural inhibitor of neovascularization. Immunofluorescent staining was used to detect the expression of TSP-1 in rabbit corneal tissue with vascularization induced by limbectomy. TSP-1 was detected in healthy and Cultured Autologous Oral Mucosal Epithelial Cell Sheet (CAOMECS) grafted rabbit corneas. TSP-1 was not detected in diseased corneas. Rabbit and human primary oral mucosal and corneal epithelial cells were cultured and treated with proteasome inhibitor (PI) in vitro. Changes in the expression of TSP-1, HIF-1 alpha and 2 alpha, VEGF-A, and VEGF receptor were analyzed by Western blotting. Neovascularization developed in rabbits' corneas as early as 1 month after limbectomy and was stable for at least 3 months. HIF-1 alpha and VEGF-A expression was reduced in CAOMECS grafted corneas, as compared to sham corneas. While TSP-1 expression was decreased in injured corneas, it was expressed in CAOMECS grafted corneas, but still less expressed compared to healthy corneas. PI treatment, of human oral mucosal and corneal epithelial cells increased TSP-1 expression and reduced VEGF-A expression. The results showed that TSP-1 expression was lost in injured corneal surface and that CAOMECS grafting restored TSP-1 expression to certain extent. Proteasome inhibition treatment increased TSP-1 and decreased VEGF-A expression in human oral mucosal and corneal epithelial cells. The result suggests that corneal neovascularization could be managed with the inhibition of the proteasome after CAOMECS grafting and increase corneal transparency.

Extensive morphological and behavioural diversity among fourteen new and seven described species in Phytophthora Clade 10 and its evolutionary implications

During extensive surveys of global Phytophthora diversity 14 new species detected in natural ecosystems in Chile, Indonesia, USA (Louisiana), Sweden, Ukraine and Vietnam were assigned to Phytophthora major Clade 10 based on a multigene phylogeny of nine nuclear and three mitochondrial gene regions. Clade 10 now comprises three subclades. Subclades 10a and 10b contain species with nonpapillate sporangia, a range of breeding systems and a mainly soil- and waterborne lifestyle. These include the previously described P. afrocarpa, P. gallica and P. intercalaris and eight of the new species: P. ludoviciana, P. procera, P. pseudogallica, P. scandinavica, P. subarctica, P. tenuimura, P. tonkinensis and P. ukrainensis. In contrast, all species in Subclade 10c have papillate sporangia and are self-fertile (or homothallic) with an aerial lifestyle including the known P. boehmeriae, P. gondwanensis, P. kernoviae and P. morindae and the new species P. celebensis, P. chilensis, P. javanensis, P. multiglobulosa, P. pseudochilensis and P. pseudokernoviae. All new Phytophthora species differed from each other and from related species by their unique combinations of morphological characters, breeding systems, cardinal temperatures and growth rates. The biogeography and evolutionary history of Clade 10 are discussed. We propose that the three subclades originated via the early divergence of pre-Gondwanan ancestors > 175 Mya into water- and soilborne and aerially dispersed lineages and subsequently underwent multiple allopatric and sympatric radiations during their global spread. Citation: Jung T, Milenković I, Corcobado T, et al. 2022. Extensive morphological and behavioural diversity among fourteen new and seven described species in Phytophthora Clade 10 and its evolutionary implications. Persoonia 49: 1-57. https://doi.org/10.3767/persoonia.2022.49.01.

An eco-friendly and sustainable support of agave-fibers functionalized with graphene/TiO2:SnO2 for the photocatalytic degradation of the 2,4-D herbicide from the drinking water

In this research, we evaluated the photocatalytic performance of biodegradable composites for the removal of the 2,4-Dichlorophenoxyacetic acid (2,4-D) herbicide. The composite was composed by agave fibers (AgF), graphene-microplates (GM) and titanium dioxide TiO₂/SnO₂ (TSn) nanoparticles (NPs) and was named TSn + AgF/GM. Both, the TSn NPs and the GM were deposited on the AgF using the Dip-coating method. According to the analysis by X-Ray Diffraction (XRD), the crystalline phase for the TiO₂ and SnO₂ was anatase and tetragonal-rutile, respectively. The Scanning Electron Microscopy (SEM) images demonstrated that the AgF were completely saturated by the GM (which had average dimensions of 15 μm × 22 μm) and by conglomerations of TSn NPs with average size of 642 nm. The TSn NPs and the TSn + AgF/GM composite were evaluated for the photocatalytic degradation of the 2,4-D herbicide under ultraviolet-visible (UV-Vis) light and found a maximum degradation of 98.4 and 93.7% (after 4 h) for the TSn NPs and the TSn + AgF/GM composite, respectively. Reuse cycles were also performed and the degradation percentage decreased by 13.1% and by 7.8% (after 3 cycles of reuse) when the TSn NPs and the TSn + AgF/GM composite are employed, respectively. Scavenger experiments were also carried out and found that the oxidizing agents are mainly produced in the order of: •OH>•O₂^- > h⁺; then, the main oxidizing agents generated during the photocatalytic reaction were the hydroxyl radicals. Thus, the photocatalytic system studied in this work for the degradation of 2,4-D could pave the way for the development of new eco-friendly/floatable photocatalysts, which can be applied in wastewater-treatment plants.

A sustainable and green chlorophyll/TiO2:W composite supported on recycled plastic bottle caps for the complete removal of Rhodamine B contaminant from drinking water

This investigation reports the photocatalytic performance of the tungsten doped titania (TiO₂:W or TW) with and without coating of chlorophyll (Chl) for the removal of the RhB dye from the drinking water. These particles were also supported on recycled plastic bottle caps (Bcap) to form other photocatalytic composites (TW/Bcap and TW + Chl/Bcap). The SEM images demonstrated that the TW particles without Chl had irregular shapes and sizes of 0.8-12 μm. The TW particles coated by the Chl presented shapes of quasi-rounded grains and smaller particle sizes of 0.8-1.8 μm. The photocatalytyic experiments showed that the photocatalyst powders containing Chl removed completely the RhB dye from the water after 2h under UV-VIS light, while the photocatalyst without Chl removed a maximum of 95% of the RhB. Interestingly, the TW/Bcap and TW + Chl/Bcap composites removed 94-100% of the RhB after 2h. Those ones removed such dye by photocatalysis and by physical adsorption at the same time (as confirmed by the absorbance and FTIR measurements), therefore, the removal of RhB was still very high. Scavenger experiments were also achieved and found that the •OH radicals are the main oxidizing species generated by the photocatalysts with and without Chl. The •O₂^- radicals and holes (h⁺) were the secondary oxidizing species. The presence of the chlorophyll on the photocatalyst increased in general the light absorption and the photocurrent. Overall, our work demonstrated that making composites with recycled plastic bottle caps is a feasible alternative to remove dyes from contaminated drinking water with high efficiency and low cost.

Abstract 1752: Switchable binding of TecApta to Atezolizumab provides the possibility of enhancing the therapeutic effects of this immune checkpoint inhibitor

One of the main goals of cancer therapeutics is to develop smart molecules that can deliver drugs or immunogens to cancer cells within the tumor, while avoiding the toxicity to normal cells. Lately, immune checkpoint inhibitors have shown significant effects in the field of cancer treatment. Atezolizumab is an immune check point inhibitor specific to PD-L1. In order to potentiate anti-tumor aspects of Atezolizumab, we have developed TecApta, a switchable single strand DNA oligonucleotide aptamer that specifically binds to this antibody with a high affinity and specificity. However, TecApta is detached from Atezolizumab upon binding of this antibody to its target PD-L1. This switchable aspect of TecApta makes it a suitable drug carrier for targeting cancer cells within the tumor microenvironment. We have developed modified versions of TecApta which include either the chemotherapy drug, gemcitabine, or the immune activator, TLR9A. Based on our in vitro data, both versions are biologically active. The gemcitabine sensitive cell line MDA-MB-231/Luc exhibits similar IC50s (20nM) for both gemcitabine-linked-TecApta (GMZ-TecApta) and the free unbound gemcitabine. Moreover, the same concentrations of TLR9A-linked-TecApta (TLR9A-TecApta) and the free TLR9A show similar effects in inducing TLR9 receptors in a cell-based assay. These results suggest that possibly GMZ-TecApta and TLR9A-TecApta can be carried by Atezolizumab and released within the tumor microenvironment, where they may induce apoptosis or aggravate an immune reaction, respectively. Animal studies will be conducted in the future to investigate the possibility of such favorable outcomes.

Citation Format: Mohammad Sadegh Atefi, Sola Takahashi, David Sich, Jessica Grondin, Rami Doueiri, Lindsay Bourgeois, Gary Olsem, Akiko Futamura, Julie Yang, Joan Oliva, John Elshimali, Carlos Pereira. Switchable binding of TecApta to Atezolizumab provides the possibility of enhancing the therapeutic effects of this immune checkpoint inhibitor [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1752.

Posology and Serum-/Xeno-Free Engineered Adipose Stromal Cells Cell Sheets

Well-characterized adipose stem cells and chemically defined culture media are important factors that control the production of the cell sheet, used in translational medicine. In this study, we have developed and engineered multilayer adipose stem cell cell sheets (ASCCSs) using chemically defined/serum-free culture media: undifferentiated or differentiated into osteoblasts and chondrocytes. In addition, using the cell sheet transmittance, we estimated the number of cells per cell sheet. Undifferentiated ASCCSs were engineered in 10 days, using serum-free/xeno-free culture media. They were CD29⁺, CD73⁺, CD90⁺, CD105+, HLA-A+, and HLA-DR-. ASCCSs differentiated into chondrocytes and osteoblasts were also engineered using chemically defined and animal-free culture media, in only 14 days. The addition of an ROCK inhibitor improved the chondrocyte cell sheet engineering. The decrease in the cell sheet transmittance rate was higher for the osteoblast cell sheets due to the intracellular Ca²⁺ accumulation. The estimation of cell number per cell sheet was carried out with the transmittance, which will provide important information for cell sheet posology. In conclusion, three types of ASCCSs were engineered using serum-free, xeno-free culture media, expressing their specific markers. Their transmittance measurement allowed estimating the number of cells per cell sheet, with a non-invasive methodology.

Photocatalytic materials immobilized on recycled supports and their role in the degradation of water contaminants: A timely review

Global concern about environmental pollution has increased in recent times due to the cumulative harmful impact on the human health occasioned by the diverse toxic substances released into the environment. Water reduced availability for human consumption and its pollution have been paid so much attention due to their relevance in agricultural and industrial activities. In this context, the advanced oxidation processes for removing contaminants from water, more specifically photocatalytic processes, have displayed their usefulness due to features such as easy application, low-cost, harmless effects and sustainable decontamination efficiency. This timely review is centered on worldwide studies, where efforts aimed at employing recycled materials as supports for purification applications such as the removal of different contaminants (dyes, pharmaceutical contaminants, and heavy metals) dissolved in aqueous environments have been reported. Materials like polyethylene terephthalic (PET), polystyrene (PS), disposal textile fabrics, newspapers, aluminum soda cans, rubber, waste electronic and electric components and used batteries have been employed either as supports for immobilizing catalysts or as photocatalysts. The present work offers a discussion of the ways through which photocatalytic composites have been immobilized or produced, employed characterization techniques, removal efficiencies achieved during photocatalytic degradation and possible degradation mechanism of pollutants; not only the highlights of all these studies are discussed, but also paths for future research works that could help improve the reported results are suggested. These new practical tools stand as novel sustainable strategies for the removal of emerging contaminants reusing waste flexible materials.

Efficient solar removal of acetaminophen contaminant from water using flexible graphene composites functionalized with Ni@TiO2:W nanoparticles

This work presents the morphological, structural and photocatalytic properties of flexible graphene composites decorated with Ni@TiO₂:W nanoparticles (TiNiW NPs) with an average size of 27 ± 2 nm. The TiNiW NPs were immobilized on the surface of a flexible graphene composite using a PVA-based slurry-paste (FG/TiNiW composite). The SEM study showed that the TiNiW NPs remained exposed on the surface of the FG/TiNiW composite, which benefited its photocatalytic activity. The photocatalytic performance for the degradation of acetaminophen (ACT) was evaluated using both the TiNiW powders and the FG/TiNiW composite, obtaining maximum degradation efficiencies of 100 and 86%, respectively, after 3 h under natural solar irradiation. The degradation of ACT was caused mainly by the reactive oxygen species such as OH radicals and h⁺, which was confirmed by scavenger experiments. Photoluminescence, XPS and absorbance experiments revealed that oxygen vacancy defects were created by i) doping the TiNiW NPs with W and by ii) introducing graphene into the composites. These defects enhanced the absorbance of light in the range of 400-800 nm, which in turn, promoted the photocatalytic degradation of ACT. Moreover, the reuse experiments confirmed that both the TiNiW NPs and FG/TiNiW composite were very stable for the degradation of ACT, since degradation efficiencies >82% were obtained after 4 reuse cycles for both photocatalysts. The experimental findings of this work demonstrate that the flexible TiO₂/graphene composites are a feasible option for the removal of pharmaceutical contaminants from water using natural solar irradiation.

Non-donor specific anti-human leukocyte antigen (HLA) antibodies are not associated with poor outcome in hematopoietic stem cell transplant recipients

Testing for anti-human leukocyte antigen (HLA) antibodies has now become standard practice in allogeneic hematopoietic stem cell transplantation (HSCT), and anti-HLA antibodies (both donor specific and non-donor specific) are being identified and have many potential consequences. Most studies suggest that donor-specific HLA antibodies lead to adverse outcomes, though little is reported on non-donor specific anti-HLA antibodies. We present the results of a retrospective cohort analysis of 157 patients who received HSCT at the University of Rochester over a period of four years. We identified 45 patients (28.7%) who had detectable anti-HLA antibodies, while only one patient (0.6%) had donor-specific anti-HLA antibodies. Patients with prior pregnancies and multiple transfusions were at increased risk to develop antibodies. In our cohort, the presence of non-donor specific anti-HLA antibodies did not significantly impact overall survival, progression free survival, graft failure, or transplant-related mortality.

Removal residues of pesticides in apricot, peach and orange processed and dietary exposure assessment

The effects of the industrial processing are evaluated of the removal of 16 pesticide residues in canned apricots and peaches and in orange juice. A method of multi-residual extraction that uses QuEChERS and liquid chromatography in tandem with triple quadrupole mass spectrometry was used. The method shows good linearity for the 16 pesticides studied (R2 > 0.999); it is accurate and precise (recoveries of 87-115%, relative standard deviation <8.0%). The processing factors are <0.6, indicating that all the processes significantly reduce the residue levels (spinosad, thiacloprid, pyridaben, bupirimate, flusilazole, triflumizole, flonicamid, imidacloprid, lambda-cyhalothrin, cyproconazole, fludioxinil and cyprodinil, abamectin, chlorpyrifos-methyl, hexythiazox and metalaxyl) initially present in the raw fruits and very significantly during washing/cutting, squeezing and hot pack canning (>55% loss). The risk quotient (EDI/ADI ratio) for canned foods is below 100, indicating that the potential consumer risk for the pesticides studied is practically negligent for human health.

Therapeutic Properties of Mesenchymal Stem Cell on Organ Ischemia-Reperfusion Injury

The shortage of donor organs is a major global concern. Organ failure requires the transplantation of functional organs. Donor’s organs are preserved for variable periods of warm and cold ischemia time, which requires placing them into a preservation device. Ischemia and reperfusion damage the organs, due to the lack of oxygen during the ischemia step, as well as the oxidative stress during the reperfusion step. Different methodologies are developed to prevent or to diminish the level of injuries. Preservation solutions were first developed to maximize cold static preservation, which includes the addition of several chemical compounds. The next chapter of organ preservation comes with the perfusion machine, where mechanical devices provide continuous flow and oxygenation ex vivo to the organs being preserved. In the addition of inhibitors of mitogen-activated protein kinase and inhibitors of the proteasome, mesenchymal stem cells began being used 13 years ago to prevent or diminish the organ’s injuries. Mesenchymal stem cells (e.g., bone marrow stem cells, adipose derived stem cells and umbilical cord stem cells) have proven to be powerful tools in repairing damaged organs. This review will focus upon the use of some bone marrow stem cells, adipose-derived stem cells and umbilical cord stem cells on preventing or decreasing the injuries due to ischemia-reperfusion.

Vitrification and storage of oral mucosa epithelial cell sheets

Shipping time and shipping delays might affect the quality of the stem cells based engineered "organs." In our laboratory, we have developed a limbal stem cell deficient (LSCD) rabbit model. To reverse the LSCD, we cultured oral mucosal epithelial cells for 2-3 weeks and engineered cultured autologous oral mucosa epithelial cell sheets (CAOMECS), which were grafted on the LSCD cornea. The purpose of this study was to vitrify CAOMECS and to store it until the CAOMECS can be grafted onto patients. CAOMECS were vitrified in LN₂ for up to 204 days. We tested two different methods of vitrification with different solutions; however, CAOMECS were only viable when they were not stored in a vitrification solution; results were only reported from this CAOMECS. On the basis of hematoxylin and eosin staining, we showed that the CAOMECS morphology was well preserved after long-term storage in LN₂ . Most of the preservation solutions maintained the CAOMECS phenotype (Ki67, proliferating cell nuclear antigen (PCNA), Beta-Catenin, ZO-1, E-Cadherin, CK3, CK4, CK13). The exception was the solution composed with ethylene glycol and Dimethyl sulfoxide (DMSO): this resulted in loss of DeltaN-p63 expression. DeltaN-p63 is an important marker for cell proliferation. The expression of proteins involved in cell-cell connection and the differentiation markers were maintained. Apoptosis was not detected in the thawed CAOMECS. We demonstrated that CAOMECS can be stored long-term in LN₂ without affecting their morphology and phenotype.

Engineering, differentiation and harvesting of human adipose-derived stem cell multilayer cell sheets

Aim: The study goals were to engineer and harvest scaffold-free undifferentiated/differentiated multilayer human adipose-derived stem cell (hADSC) cell sheets, in absence of treatment. Materials & methods: The hADSC are seeded in 35 mm culture dishes. At confluence or when multilayer cell sheets are formed, hADSC are treated with predefined differentiation culture media (adipocyte, chondrocyte and osteoblast). Results: Undifferentiated hADSC and differentiated adipocyte, osteoblast and chondrocyte hADSC multilayer cell sheets (hADSCmCS) have been harvested. Hematoxylin & eosin showed the formation of multilayer cell sheets. Undifferentiated hADSC multilayer cell sheets preserve their stem cell markers. Differentiated adipocyte, osteoblast and chondrocyte hADSCmCS expressed specific markers. Conclusion: This simple protocol opens possibilities to engineer scaffold-free hADSCm cell sheet to transplant them on damaged organs.

Proteasome and Organs Ischemia-Reperfusion Injury

The treatment of organ failure on patients requires the transplantation of functional organs, from donors. Over time, the methodology of transplantation was improved by the development of organ preservation solutions. The storage of organs in preservation solutions is followed by the ischemia of the organ, resulting in a shortage of oxygen and nutrients, which damage the tissues. When the organ is ready for the transplantation, the reperfusion of the organ induces an increase of the oxidative stress, endoplasmic reticulum stress, and inflammation which causes tissue damage, resulting in a decrease of the transplantation success. However, the addition of proteasome inhibitor in the preservation solution alleviated the injuries due to the ischemia-reperfusion process. The proteasome is a protein structure involved in the regulation the inflammation and the clearance of damaged proteins. The goal of this review is to summarize the role of the proteasome and pharmacological compounds that regulate the proteasome in protecting the organs from the ischemia-reperfusion injury.

Proteasomes in corneal epithelial cells and cultured autologous oral mucosal epithelial cell sheet (CAOMECS) graft used for the ocular surface regeneration

PURPOSE

This study focuses on characterizing proteasomes in corneal epithelial cells (CEC) and in cultured autologous oral mucosal epithelial cell sheets (CAOMECS) used to regenerate the ocular surface.

METHODS

Limbal stem cell deficiency (LSCD) was surgically induced in rabbit corneas. CAOMECS was engineered and grafted onto corneas with LSCD to regenerate the ocular surface.

RESULTS

LSCD caused an increase in inflammatory cells in the ocular surface, an increase in the formation of immunoproteasomes (IPR), and a decrease in the formation of constitutive proteasome (CPR). Specifically, LSCD-diseased CEC (D-CEC) showed a decrease in the CPR chymotrypsin-like, trypsin-like and caspase-like activities, while healthy CEC (H-CEC) and CAOMECS showed higher activities. Quantitative analysis of IPR inducible subunit (B5i, B2i, and B1i) were performed and compared to CPR subunit (B5, B2, and B1) levels. Results showed that ratios B5i/B5, B2i/B2 and B1i/B1 were higher in D-CEC, indicating that D-CEC had approximately a two-fold increase in the amount of IPR compared to CAOMECS and H-CEC. Histological analysis demonstrated that CAOMECS-grafted corneas had a re-epithelialized surface, positive staining for CPR subunits, and weak staining for IPR subunits. In addition, digital quantitative measurement of fluorescent intensity showed that the CPR B5 subunit was significantly more expressed in CAOMECS-grafted corneas compared to non-grafted corneas with LSCD.

CONCLUSION

CAOMECS grafting successfully replaced the D-CEC with oral mucosal epithelial cells with higher levels of CPR. The increase in constitutive proteasome expression is possibly responsible for the recovery and improvement in CAOMECS-grafted corneas.

The Role of E-Cadherin in Maintaining the Barrier Function of Corneal Epithelium after Treatment with Cultured Autologous Oral Mucosa Epithelial Cell Sheet Grafts for Limbal Stem Deficiency

The role of E-cadherin in epithelial barrier function of cultured autologous oral mucosa epithelial cell sheet (CAOMECS) grafts was examined. CAOMECS were cultured on a temperature-responsive surface and grafted onto rabbit corneas with Limbal Stem Cell Deficiency (LSCD). E-cadherin levels were significantly higher in CAOMECS compared to normal and LSCD epithelium. Beta-catenin colocalized with E-cadherin in CAOMECS cell membranes while phosphorylated beta-catenin was significantly increased. ZO-1, occludin, and Cnx43 were also strongly expressed in CAOMECS. E-cadherin and beta-catenin localization at the cell membrane was reduced in LSCD corneas, while CAOMECS-grafted corneas showed a restoration of E-cadherin and beta-catenin expression. LSCD corneas did not show continuous staining for ZO-1 or for Cnx43, while CAOMECS-grafted corneas showed a positive expression of ZO-1 and Cnx43. Cascade Blue® hydrazide did not pass through CAOMECS. Because E-cadherin interactions are calcium-dependent, EGTA was used to chelate calcium and disrupt cell adhesion. EGTA-treated CAOMECS completely detached from cell culture surface, and E-cadherin levels were significantly decreased. In conclusion, E cadherin high expression contributed to CAOMECS tight and gap junction protein recruitment at the cell membrane, thus promoting cellular adhesion and a functional barrier to protect the ocular surface.

Transcriptional responses of Norway spruce (Picea abies) inner sapwood against Heterobasidion parviporum

The white-rot fungus Heterobasidion parviporum Niemelä & Korhonen establishes a necrotrophic interaction with Norway spruce (Picea abies (L.) H.Karst.) causing root and butt rot and growth losses in living trees. The interaction occurs first with the bark and the outer sapwood, as the pathogen enters the tree via wounds or root-to-root contacts. Later, when the fungus reaches the heartwood, it spreads therein creating a decay column, and the interaction mainly occurs in the inner sapwood where the tree creates a reaction zone. While bark and outer sapwood interactions are well studied, little is known about the nature of the transcriptional responses leading to the creation of a reaction zone. In this study, we sampled bark and sapwood both proximal and distal to the reaction zone in artificially inoculated and naturally infected trees. We quantified gene expression levels of candidate genes in secondary metabolite, hormone biosynthesis and signalling pathways using quantitative polymerase chain reaction. An up-regulation of mainly the phenylpropanoid pathway and jasmonic acid biosynthesis was found at the inoculation site, when inoculations were compared with wounding. We found that transcriptional responses in inner sapwood were similar to those reported upon infection through the bark. Our data suggest that the defence mechanism is induced due to direct fungal contact irrespective of the tissue type. Understanding the nature of these interactions is important when considering tree breeding-based resistance strategies to reduce the spread of the pathogen between and within trees.

The role of defoliation and root rot pathogen infection in driving the mode of drought-related physiological decline in Scots pine (Pinus sylvestris L.)

Drought-related tree die-off episodes have been observed in all vegetated continents. Despite much research effort, however, the multiple interactions between carbon starvation, hydraulic failure and biotic agents in driving tree mortality under field conditions are still not well understood. We analysed the seasonal variability of non-structural carbohydrates (NSCs) in four organs (leaves, branches, trunk and roots), the vulnerability to embolism in roots and branches, native embolism (percentage loss of hydraulic conductivity (PLC)) in branches and the presence of root rot pathogens in defoliated and non-defoliated individuals in a declining Scots pine (Pinus sylvestris L.) population in the NE Iberian Peninsula in 2012, which included a particularly dry and warm summer. No differences were observed between defoliated and non-defoliated pines in hydraulic parameters, except for a higher vulnerability to embolism at pressures below -2 MPa in roots of defoliated pines. No differences were found between defoliation classes in branch PLC. Total NSC (TNSC, soluble sugars plus starch) values decreased during drought, particularly in leaves. Defoliation reduced TNSC levels across tree organs, especially just before (June) and during (August) drought. Root rot infection by the fungal pathogen Onnia P. Karst spp. was detected but it did not appear to be associated to tree defoliation. However, Onnia infection was associated with reduced leaf-specific hydraulic conductivity and sapwood depth, and thus contributed to hydraulic impairment, especially in defoliated pines. Infection was also associated with virtually depleted root starch reserves during and after drought in defoliated pines. Moreover, defoliated and infected trees tended to show lower basal area increment. Overall, our results show the intertwined nature of physiological mechanisms leading to drought-induced mortality and the inherent difficulty of isolating their contribution under field conditions.

Bortezomib enhances fatty liver preservation in Institut George Lopez-1 solution through adenosine monophosphate activated protein kinase and Akt/mTOR pathways

OBJECTIVES

The aim of this study is to investigate the protective mechanisms induced by bortezomib added to Institut George Lopez (IGL)-1 preservation solution to protect steatotic livers against cold ischaemia reperfusion injury and to examine whether these mechanisms occur through the activation of adenosine monophosphate activated protein kinase (AMPK), Akt/mTOR pathways.

METHODS

Steatotic livers from obese rats were preserved for 24 h (at 4 °C) in IGL-1 solution with or without bortezomib (100 nM) or pretreated with AMPK inhibitor adenine 9-α-D-arabinofuranoside and preserved in IGL-1 + bortezomib. Livers were then perfused for 2 h at 37 °C. Liver injury (alanine aminotransferase/aspartate aminotransferase) and function (bile production and vascular resistance) were measured. Also, Akt/mTOR, phosphorylated AMPK (pAMPK) and apoptosis were determined by Western blot analyses.

KEY FINDINGS

Bortezomib addition to IGL-1 solution significantly reduced steatotic liver injury, improved graft function and decreased liver apoptosis. These benefits were diminished by the pretreatment of obese rats with AMPK inhibitor Ara. Western blot analyses showed a significant increase in pAMPK after ischaemia and reperfusion. We also observed a significant phosphorylation of Akt in IGL-1 +bortezomib group that, in turn, induced the phosphorylation of mTOR and glycogen synthase kinase 3β.

CONCLUSIONS

Bortezomib, at low and non toxic concentration, is a promising additive to IGL-1 solution for steatotic liver preservation. Its protective effect is due to the activation of AMPK and Akt/mTOR pathways.

FAT10 knock out mice livers fail to develop Mallory-Denk bodies in the DDC mouse model

Mallory-Denk bodies (MDBs) are aggresomes composed of undigested ubiqutinated short lived proteins which have accumulated because of a decrease in the rate of their degradation by the 26s proteasome. The decrease in the activity of the proteasome is due to a shift in the activity of the 26s proteasome to the immunoproteasome triggered by an increase in expression of the catalytic subunits of the immunoproteasome which replaces the catalytic subunits of the 26s proteasome. This switch in the type of proteasome in liver cells is triggered by the binding of IFNγ to the IFNγ sequence response element (ISRE) located on the FAT10 promoter. To determine if either FAT10 or IFNγ are essential for the formation of MDBs we fed both IFNγ and FAT10 knock out (KO) mice DDC added to the control diet for 10weeks in order to induce MDBs. Mice fed the control diet and Wild type mice fed the DDC or control diet were compared. MDBs were located by immunofluorescent double stains using antibodies to ubiquitin to stain MDBs and FAT10 to localize the increased expression of FAT10 in MDB forming hepatocytes. We found that MDB formation occurred in the IFNγ KO mice but not in the FAT10 KO mice. Western blots showed an increase in the ubiquitin smears and decreases β 5 (chymotrypsin-like 26S proteasome subunit) in the Wild type mice fed DDC but not in the FAT10 KO mice fed DDC. To conclude, we have demonstrated that FAT10 is essential to the induction of MDB formation in the DDC fed mice.

A computational knowledge-based model for emulating human performance in the Iowa Gambling Task

A new computational knowledge-based model for emulating human performance in decision making tasks is proposed. This model is mainly based on the knowledge acquired through past experience, the knowledge extracted from the environment and the relationships between the concepts that represent these two kinds of knowledge. The proposed model divides the decision making process into two phases. The first phase lies in the estimation of the decision outcomes using a net of concepts. In the second phase, the proposed model uses a value function to score each possible alternative. The design of the model focuses on some psychological and neurophysiological evidence from current research. In order to validate the model, it is compared with other widely used models that implement different theories of decision making under risk and uncertainty. The model comparison is centered on a well defined task, the Iowa Gambling Task, used in several psychological experiments. The comparison applies an evaluation method based on the optimization of each model in order to emulate human performance individually starting both the participant and the model from the same environmentally available information. The results show that the performance of the proposed model is quantitatively better than the other compared models. Besides, using relevant concepts extracted from interviews with the participants increases the performance of the proposed model.

Biogenic hydroxyapatite (Apatite II™) dissolution kinetics and metal removal from acid mine drainage

Apatite II™ is a biogenic hydroxyapatite (expressed as Ca(5)(PO(4))OH) derived from fish bone. Using grains of Apatite II™ with a fraction size between 250 and 500 μm, batch and flow-through experiments were carried out to (1) determine the solubility constant for the dissolution reaction Ca(5)(PO(4))(3)(OH) ⇔ 5Ca(2+) + 3PO(4)(3-) + OH(-), (2) obtain steady-state dissolution rates over the pH range between 2.22 and 7.14, and (3) study the Apatite II™'s mechanisms to remove Pb(2+), Zn(2+), Mn(2+), and Cu(2+) from metal polluted water as it dissolves. The logK(S) value obtained was -50.8±0.82 at 25 °C. Far-from-equilibrium fish-bone hydroxyapatite dissolution rates decrease by increasing pH. Assuming that the dissolution reaction is controlled by fast adsorption of a proton on a specific surface site that dominates through the pH range studied, probably ≡PO(-), followed by a slow hydrolysis step, the dissolution rate dependence is expressed in mol m(-2) s(-1) as where Rate(25 °C) = -8.9 × 10(-10) × [9.96 × 10(5) × a(H+)]/[1 + 9.96 × 10(5) × a(H+)] where a(H+) is the proton activity in solution. Removal of Pb(2+), Zn(2+), Mn(2+) and Cu(2+) was by formation of phosphate-metal compounds on the Apatite II™ substrate, whereas removal of Cd(2+) was by surface adsorption. Increase in pH enhanced the removal of aqueous heavy metals. Using the kinetic parameters obtained (e.g., dissolution rate and pH-rate dependence law), reactive transport simulations reproduced the experimental variation of pH and concentrations of Ca, P and toxic divalent metal in a column experiment filled with Apatite II™ that was designed to simulate the Apatite II™-metal polluted water interaction.

The use of a reversible proteasome inhibitor in a model of Reduced-Size Orthotopic Liver transplantation in rats

Ischemia/reperfusion injury (IRI), inherent in liver transplantation (LT), is the main cause of initial deficiencies and primary non-function of liver allografts. Living-related LT was developed to alleviate the mortality resulting from the scarcity of suitable deceased grafts. The main problem in using living-related LT for adults is graft size disparity. In this study we propose for the first time that the use of a proteasome inhibitor (Bortezomib) treatment could improve liver regeneration and reduce IRI after Reduced-Size Orthotopic Liver transplantation (ROLT). Rat liver grafts were reduced by removing the left lateral lobe and the two caudate lobes and preserved in UW or IGL-1 preservation solution for 1h liver and then subjected to ROLT with or without Bortezomib treatment. Our results show that Bortezomib reduces IRI after LT and is correlated with a reduction in mitochondrial damage, oxidative stress and endoplasmic reticulum stress. Furthermore, Bortezomib also increased liver regeneration after reduced-size LT and increased the expression of well-known ischemia/reperfusion protective proteins such as nitric oxide synthase, heme oxigenase 1 (HO-1) and Heat Shock Protein 70. Our results open new possibilities for the study of alternative therapeutic strategies aimed at reducing IRI and increasing liver regeneration after LT. It is hoped that the results of our study will contribute towards improving the understanding of the molecular processes involved in IRI and liver regeneration, and therefore help to improve the outcome of this type of LT in the future.