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Different series of Au on carbon catalysts were prepared via sol-immobilization to investigate the role of polymers (polyvinylpyrrolidone PVP, polyethylene glycol PEG and polyvinyl alcohol PVA), employed as gold nanoparticle (NP) stabilizers, on catalyst properties and on catalytic activity. The synthesized materials were widely characterized with several techniques (DLS, XRD, TEM and XPS) and used as catalysts in the 5-hydroxymethylfurfural (HMF) oxidation to produce 2,5-furandicarboxylic acid (FDCA). The obtained results clearly demonstrated the PVA leading to the formation of smaller and more active NPs. On the contrary, polyethylene glycol was shown to affect gold exposure and, as a consequence, to reduce the catalyst activity due to steric effects while PVP-based catalysts presented bigger and more covered Au NPs. The investigation on the reusability of the catalysts demonstrated the presence of a significant deactivation on all prepared materials, but the presence of higher amounts of polymer seems to have a positive effect on catalyst stability even if associated with lower reactivity. Computational studies have provided interesting information on the NP-polymer interactions and consequently on the catalytic activities.

The ability to induce a hypothermia resembling that of natural torpor would be greatly beneficial in medical and non-medical fields. At present, two procedures based on central nervous pharmacological manipulation have been shown to be effective in bringing core body temperature well below 30°C in the rat, a non-hibernator: the first, based on the inhibition of a key relay in the central thermoregulatory pathway, the other, based on the activation of central adenosine A1 receptors. Although the role of mitochondria in the activation and maintenance of torpor has been extensively studied, no data are available for centrally induced hypothermia in non-hibernators. Thus, in the present work the respiration rate of mitochondria in the liver and in the kidney of rats following the aforementioned hypothermia-inducing treatments was studied. Moreover, to have an internal control, the same parameters were assessed in a well-consolidated model, i.e., mice during fasting-induced torpor. Our results show that state 3 respiration rate, which significantly decreased in the liver of mice, was unchanged in rats. An increase of state 4 respiration rate was observed in both species, although it was not statistically significant in rats under central adenosine stimulation. Also, a significant decrease of the respiratory control ratio was detected in both species. Finally, no effects were detected in kidney mitochondria in both species. Overall, in these hypothermic conditions liver mitochondria of rats remained active and apparently ready to be re-activated to produce energy and warm up the cells. These findings can be interpreted as encouraging in view of the finalization of a translational approach to humans.

We recently showed that the long-term in vivo administration of green tea catechin extract (GTE) resulted in hyperdynamic cardiomyocyte contractility. The present study investigates the mechanisms underlying GTE action in comparison to its major component, epigallocatechin-3-gallate (EGCG), given at the equivalent amount that would be in the entirety of GTE. Twenty-six male Wistar rats were given 40 mL/day of a tap water solution with either standardized GTE or pure EGCG for 4 weeks. Cardiomyocytes were then isolated for the study. Cellular bioenergetics was found to be significantly improved in both GTE- and EGCG-fed rats compared to that in controls as shown by measuring the maximal mitochondrial respiration rate and the cellular ATP level. Notably, the improvement of mitochondrial function was associated with increased levels of oxidative phosphorylation complexes, whereas the cellular mitochondrial mass was unchanged. However, only the GTE supplement improved cardiomyocyte mechanics and intracellular calcium dynamics, by lowering the expression of total phospholamban (PLB), which led to an increase of both the phosphorylated-PLB/PLB and the sarco-endoplasmic reticulum calcium ATPase/PLB ratios. Our findings suggest that GTE might be a valuable adjuvant tool for counteracting the occurrence and/or the progression of cardiomyopathies in which mitochondrial dysfunction and alteration of intracellular calcium dynamics constitute early pathogenic factors.

The role of reactive oxygen species (ROS) in the metabolic reprogramming of cells adapted to hypoxia and the interplay between ROS and hypoxia in malignancy is under debate. Here, we examined how ROS levels are modulated by hypoxia in human cancer compared to untransformed cells. Short time exposure (20 min) of either fibroblasts or 143B osteosarcoma cells to low oxygen tension down to 0.5% induced a significant decrease of the cellular ROS level, as detected by the CellROX fluorescent probe (&minus, 70%). Prolonging the cells&rsquo, exposure to hypoxia for 24 h, ROS decreased further, reaching nearly 20% of the normoxic value. In this regard, due to the debated role of the endogenous inhibitor protein (IF1) of the ATP synthase complex in cancer cell bioenergetics, we investigated whether IF1 is involved in the control of ROS generation under severe hypoxic conditions. A significant ROS content decrease was observed in hypoxia in both IF1-expressing and IF1- silenced cells compared to normoxia. However, IF1-silenced cells showed higher ROS levels compared to IF1-containing cells. In addition, the MitoSOX Red-measured superoxide level of all the hypoxic cells was significantly lower compared to normoxia, however, the decrease was milder than the marked drop of ROS content. Accordingly, the difference between IF1-expressing and IF1-silenced cells was smaller but significant in both normoxia and hypoxia. In conclusion, the interplay between ROS and hypoxia and its modulation by IF1 have to be taken into account to develop therapeutic strategies against cancer.

Dysfunctions caused by genetic defects in the mitochondrial DNA (mtDNA) of humans are called mitochondrial diseases; however, mtDNA mutations are also associated with aging and age-related diseases. Here, we present an original cellular model that allows gathering information on molecules that might contrast or prevent mitochondrial dysfunctions and their related diseases. This model allowed us to show that resveratrol (RSV), a phytochemical present in food, exerts protective effects at low concentrations on resting human fibroblasts carrying dysfunctional respiratory chain Complex I. Cells were maintained both in resting condition, to mimic the high energy demanding post-mitotic tissues (serum absence and gramicidin presence), and under glucose deficiency to push the synthesis of ATP via oxidative phosphorylation. Pre-incubation with RSV prolonged the viability of the fibroblasts exposed to rotenone, a well-known specific inhibitor of the respiratory chain Complex I, and decreased mitochondrial fragmentation. It significantly prevented the oxidative phosphorylation impairment indirectly caused by the rotenone-mediated Complex I inhibition, allowing for an almost complete preservation of the cellular ATP level. Indeed, RSV limited the rotenone-induced reactive oxygen species increase, allowing for the maintenance of a functional mitochondrial membrane potential. These findings indicate the potential usage of resveratrol to prevent or possibly treat many disorders, in which the bioenergetic defects and oxidative stress are the primary (mitochondrial encephalomyopathy), or the secondary (age-related diseases) causes of the pathology; and to also assist cell senescence during aging.

Thermal injuries affect 250,000 people annually in the United Kingdom. As burn survival improves, good scar management is paramount to help individuals living with the resultant scars lead a life without restrictions. Post-burn hypertrophic scars can limit growth in children, interfere with function and cause psychological problems. In the current literature there is great variation in post-burn scar management across the world and in the evidence available for the efficacy of these management modalities. The aim of this study was to investigate the variances if any, in the management of post-burn scarring in children across the UK. A telephone survey of UK paediatric burn services was conducted to obtain information on post-burn scar management and advice given to patients/carers. Of the 19 burn services that participated, all advised moisturising of scars but with variable emphasis on massaging. Silicones and pressure therapy were used by 18 services but commencement of use varied from soon after healing to onset of hypertrophic scarring. Laser therapy, ultrasound therapy and steroid therapy were used sporadically. This study highlights the common modalities of post-burn scar management in children across the UK. However, there is marked variation in timing and selection of the commonly used modalities. Although this study did not investigate the outcomes of scar management, it clearly identifies the need for a well-designed multi-centred study to establish evidence-based best practice in the management of post-burn scarring in children as these modalities are time consuming and not without potential complications. Evidence based practice could potentially lead to significant financial savings to the health service.

MicroRNAs (miRs) are small noncoding RNAs that regulate gene expression primarily through translational repression. In erythropoietic (E) culture of cord blood CD34+ progenitor cells, the level of miR 221 and 222 is gradually and sharply down-modulated. Hypothetically, this decline could promote erythropoiesis by unblocking expression of key functional proteins. Indeed, ( i ) bioinformatic analysis suggested that miR 221 and 222 target the 3′ UTR of kit mRNA; ( ii ) the luciferase assay confirmed that both miRs directly interact with the kit mRNA target site; and ( iii ) in E culture undergoing exponential cell growth, miR down-modulation is inversely related to increasing kit protein expression, whereas the kit mRNA level is relatively stable. Functional studies show that treatment of CD34+ progenitors with miR 221 and 222, via oligonucleotide transfection or lentiviral vector infection, causes impaired proliferation and accelerated differentiation of E cells, coupled with down-modulation of kit protein: this phenomenon, observed in E culture releasing endogenous kit ligand, is magnified in E culture supplemented with kit ligand. Furthermore, transplantation experiments in NOD-SCID mice reveal that miR 221 and 222 treatment of CD34+ cells impairs their engraftment capacity and stem cell activity. Finally, miR 221 and 222 gene transfer impairs proliferation of the kit+ TF-1 erythroleukemic cell line. Altogether, our studies indicate that the decline of miR 221 and 222 during exponential E growth unblocks kit protein production at mRNA level, thus leading to expansion of early erythroblasts. Furthermore, the results on kit+ erythroleukemic cells suggest a potential role of these miRs in cancer therapy.

Summary Background: Peer-assisted learning (PAL) involves medical students teaching other medical students. Although the concept is not new, formal PAL is a relatively new development in medical education. Context: PAL Manchester is a peer-assisted learning scheme that has run for over 6 years at Salford Royal NHS Foundation Trust. It is a student-led scheme that teaches clinical skills to medical students in years 3–5 of the Manchester curriculum. The scheme comprises small group sessions of 12 students and two peer tutors. Innovation: Here, we present the experiences of PAL Manchester from three perspectives: student (Francesca Liuzzi), peer tutor (Elspeth Hill) and student co-ordinator (James Giles). These accounts illustrate the roles within PAL Manchester and the personal benefits that may be derived from such a scheme. Implications: Different roles for medical students can be developed within a PAL scheme, presenting different challenges and benefits to participants.

Antioxidants-that is, scavengers of free radicals and anaerobic conditions (5%CO(2), 95% N(2))-protect monocytic U937 cells from damage-induced apoptosis. Antioxidants rescue the cells acting on the apoptotic pathway at a step downstream from gluthatione extrusion. Reducing agents, such as DTT, also reduce stress-induced apoptosis. Thus, apoptotic GSH extrusion triggers the downstream events of apoptosis by leaving cells unprotected against thiol\s oxidation and radical production.

It is generally accepted that microRNAs (miRs) control basic biological functions, such as cell proliferation and differentiation. However, only few targets of the ~ 300 known mammalian miRs have been validated so far, thus hampering delineation of miR-based control circuitries. Particularly, little is known on miR function in mammalian hematopoiesis. We have investigated by microarray and Northern blot evalutation miR expression profiles in human megakarypoiesis, as evaluated in cord blood hematopoietic progenitor cell (HPC) unilineage culture through the megakaryopoietic (MK) differentiation-maturation pathway. These studies indicated that miR-155, -221 and -222 are abundant in HPCs, but sharply decline during megakaryopoiesis. The decline may favour megakaryopoiesis by unblocking translation of key functional target protein(s). Bioinformatic analysis predicted that miR-155, -221 and -222 target Ets-1, a transcription factor up-regulated in Mk differentiation, which transactivates relevant Mk genes (e.g., TPO receptor, PF4, CD42 and von Willebrand factor). Consistently, in megakaryocytic cells the increase of Ets-1 protein expression coincides with the miR-155, -221 and -222 decrease. To find out whether Ets-1 mRNA is a possible target of miR-155, -221 and -222, we cloned segments of the 3′UTR of the Ets-1 gene downstream of a firefly luciferase ORF. Luciferase assay confirmed a direct interaction between each of these miRs and the 3′UTR of Ets-1. Functional studies showed that enhanced expression of these three miRs impairs proliferation, differentiation and maturation of MK cells, at least in part via enhanced degradation of Ets1 mRNA and down-modulation of Ets-1 protein. Similar results were obtained by RNA interference against Ets-1. Finally, HPCs transfected with miR-155, -221, and -222 showed a significant reduction of their Mk clonogenic capacity, suggesting that down-modulation of these miRs favours MK progenitor recruitment and commitment. Altogether, these studies indicate that a novel regulatory circuitry, based on miR-155, -221, -222 multitargeting Ets-1 mRNA leading in turn to transactivation of Mk-specific genes, plays a key role in the control of megakaryopoiesis at both progenitor and precursor level.

MicroRNAs (miRs) are small non-coding RNAs that regulate gene expression primarily through translational repression. In unilineage erythropoietic (E) culture of cord blood (CB) CD34+ progenitor cells, the level of miR 221 and 222 is gradually and sharply downmodulated. Hypothetically, this decline could promote erythropoiesis by unblocking expression of key functional proteins. Our studies indicate that miR 221 and 222 target the Kit receptor: specifically, (a) the luciferase targeting assay showed that miR 221 and 222 directly interact with the 3′UTR of Kit mRNA; (b) in E culture the miR 221 and 222 level is inversely related to Kit protein expression, whereas the abundance of Kit mRNA is relatively stable. Functional studies show that treatment of CD34+ cells with miR 221 and 222, via oligonucleotide transfection or lentiviral vector infection, causes impaired proliferation and accelerated differentiation of E cells, coupled with downmodulation of Kit protein: this phenomenon, observed in E culture releasing endogenous Kit ligand (KL), is magnified in E culture supplemented with KL. Furthermore, transplantation experiments into NOD-SCID mice reveal that miR 221 or 222 treatment of CD34+ cells impairs their engraftment capacity and stem cell activity. Finally, miR 221 and 222 gene transfer impairs proliferation of the TF1 erythroleukemic cell line, expressing the Kit receptor. Altogether, our studies indicate that in human erythropoiesis the decline of miR 221 and 222 unblocks Kit protein production at translational level, thus leading to expansion of early E cells. Furthermore, overexpression of miR 221 and 222 inhibits proliferation of Kit+ erythroleukemic cells, suggesting a potential role of these microRNAs in cancer therapy.

MicroRNAs (miRs) are a novel regulatory class of non-coding, single-stranded RNAs of ~ 22 nucleotides, identified in plants and animals. MiRs repress protein expression at post-transcriptional level, mostly through base pairing to the 3′ untranslated region (UTR) of the target mRNA, thus leading to its degradation and/or reduced translation. MiRs have been shown to control basic biological functions, such as cell proliferation and differentiation. However, little is known on their role in hematopoiesis. Furthermore, in diverse types of cancer miRs may function as “oncomirs”. We investigated the role of miR-17-5p, -20a and -106a, located in the miR-17-5p-92 and miR-106a-92 clusters respectively, in monocytic-macrophage (Mo) differentiation-maturation. In unilineage Mo culture generated by cord blood (CB) hematopoietic progenitor cells (HPC), these miRs are gradually and markedly downmodulated, whereas AML1 is upmodulated at protein but not at mRNA level. The acute myeloid leukaemia-1 protein (AML1, also known as Runt-related transcription factor 1, Runx1) is the DNA-binding subunit of the hematopoietic transcription factor CBF, which plays a pivotal role in Mo differentiation-maturation. Luciferase assay shows that miR-17/20/106 bind the AML1 mRNA 3′UTR, implying that during monocytopoiesis their decline unblocks AML1 translation. Mo culture transfection with miR-17/20/106 stimulates blast cell proliferation and inhibits differentiation-maturation: this is coupled with AML1 translation blockade, leading in turn to inhibition of M-CSF receptor (M-CSFR) expression. Equivalent results were observed in Mo clonogenic culture of HPCs. Knockdown of endogenous miR-17/20/106 by anti-miR oligonucleotide transfection causes opposite effects. Altoghether, our studies indicate that miR-17/20/106 downmodulation during monocytopoiesis “unblocks” the translation of AML1, which in turn transactivates the M-CSFR, thereby allowing Mo differentiation and maturation. We hence propose that these miRs function as a master gene complex underlying the monocytopoiesis gene program, at least in part through the regulation of two pivotal proteins, AML1 and M-CSFR. This study also sheds light on other relevant aspects:the regulatory action of miR-17/20/106 action on AML1 mRNA is restricted to the Mo lineage, implying a role for lineage-specific factor(s) to modulate the interaction of these miRs with their mRNA target;the subtle complexity of mechanisms controlling the transcription/processing of the miR-17-5p-92 cluster, implied by the differential expression patterns of the miRs comprised in the 17-5p-92 polycistron in Mo culture;the leukemogenesis mediated by AML1 fusion proteins.