Enhanced M1 Macrophage Polarization in Human Helicobacter pylori-Associated Atrophic Gastritis and in Vaccinated Mice

Background: Infection with Helicobacter pylori triggers a chronic gastric inflammation that can progress to atrophy and gastric adenocarcinoma. Polarization of macrophages is a characteristic of both cancer and infection, and may promote progression or resolution of disease. However, the role of macrophages and their polarization during H. pylori infection has not been well defined. Methodology/Principal Findings: By using a mouse model of infection and gastric biopsies from 29 individuals, we have analyzed macrophage recruitment and polarization during H. pylori infection by flow cytometry and real-time PCR. We found a sequential recruitment of neutrophils, eosinophils and macrophages to the gastric mucosa of infected mice. Gene expression analysis of stomach tissue and sorted macrophages revealed that gastric macrophages were polarized to M1 after H. pylori infection, and this process was substantially accelerated by prior vaccination. Human H. pylori infection was characterized by a mixed M1/M2 polarization of macrophages. However, in H. pylori-associated atrophic gastritis, the expression of inducible nitric oxide synthase was markedly increased compared to uncomplicated gastritis, indicative of an enhanced M1 macrophage polarization in this pre-malignant lesion. Conclusions/Significance: These results show that vaccination of mice against H. pylori amplifies M1 polarization of gastric macrophages, and that a similar enhanced M1 polarization is present in human H. pylori-induced atrophic gastritis

Lawson criterion for ignition exceeded in an inertial fusion experiment

For more than half a century, researchers around the world have been engaged in attempts to achieve fusion ignition as a proof of principle of various fusion concepts. Following the Lawson criterion, an ignited plasma is one where the fusion heating power is high enough to overcome all the physical processes that cool the fusion plasma, creating a positive thermodynamic feedback loop with rapidly increasing temperature. In inertially confined fusion, ignition is a state where the fusion plasma can begin "burn propagation" into surrounding cold fuel, enabling the possibility of high energy gain. While "scientific breakeven" (i.e., unity target gain) has not yet been achieved (here target gain is 0.72, 1.37 MJ of fusion for 1.92 MJ of laser energy), this Letter reports the first controlled fusion experiment, using laser indirect drive, on the National Ignition Facility to produce capsule gain (here 5.8) and reach ignition by nine different formulations of the Lawson criterion

Omega-3 fatty acid EPA improves regenerative capacity of mouse skeletal muscle cells exposed to saturated fat and inflammation

© 2016 The Author(s) Sarcopenic obesity is characterised by high fat mass, low muscle mass and an elevated inflammatory environmental milieu. We therefore investigated the effects of elevated inflammatory cytokine TNF-α (aging/obesity) and saturated fatty acid, palmitate (obesity) on skeletal muscle cells in the presence/absence of EPA, a-3 polyunsaturated fatty acid with proposed anti-inflammatory, anti-obesity activities. In the present study we show that palmitate was lipotoxic, inducing high levels of cell death and blocking myotube formation. Cell death under these conditions was associated with increased caspase activity, suppression of differentiation, reductions in both creatine kinase activity and gene expression of myogenic factors; IGF-II, IGFBP-5, MyoD and myogenin. However, inhibition of caspase activity via administration of Z-VDVAD-FMK (caspase-2), Z-DEVD-FMK (caspase-3) and ZIETD-KMK (caspase 8) was without effect on cell death. By contrast, lipotoxicity associated with elevated palmitate was reduced with the MEK inhibitor PD98059, indicating palmitate induced cell death was MAPK mediated. These lipotoxic conditions were further exacerbated in the presence of inflammation via TNF-α co-administration. Addition of EPA under cytotoxic stress (TNF-α) was shown to partially rescue differentiation with enhanced myotube formation being associated with increased MyoD, myogenin, IGF-II and IGFBP-5 expression. EPA had little impact on the cell death phenotype observed in lipotoxic conditions but did show benefit in restoring differentiation under lipotoxic plus cytotoxic conditions. Under these conditions Id3 (inhibitor of differentiation) gene expression was inversely linked with survival rates, potentially indicating a novel role of EPA and Id3 in the regulation of apoptosis in lipotoxic/cytotoxic conditions. Additionally, signalling studies indicated the combination of lipo- and cyto-toxic effects on the muscle cells acted through ceramide, JNK and MAPK pathways and blocking these pathways using PD98059 (MEK inhibitor) and Fumonisin B1 (ceramide inhibitor) significantly reduced levels of cell death. These findings highlight novel pathways associated with in vitro models of lipotoxicity (palmitate-mediated) and cytotoxicity (inflammatory cytokine mediated) in the potential targeting of molecular modulators of sarcopenic obesity

Inefficient skeletal muscle repair in inhibitor of differentiation knockout mice suggests a crucial role for BMP signaling during adult muscle regeneration

The bone morphogenetic protein (BMP) pathway is known to be involved in limb myogenesis during development, but whether it is involved in postnatal muscle regeneration is unclear. We have found that adult inhibitor of differentiation (Id)-mutant (Id1+/−Id3−/−) mice display delayed and reduced skeletal muscle regeneration after injury compared with either wild-type littermates or Id3-null mice. Immunoblotting of wild-type muscle lysates revealed that, not only were Id1 and Id3 highly upregulated within 24 h after injury, but other upstream components of the BMP pathway were as well, including the BMP receptor type II and phosphorylated Smad1/5/8 (pSmad1/5/8). Inhibition of BMP signaling in injured skeletal muscle by Noggin injection reduced pSmad1/5/8, Id1, and Id3 protein levels. The mouse myoblast-derived cell line C2C12 also expressed Id1, Id3, BMP receptor type II, and pSmad1/5/8 during proliferation, but all were reduced upon differentiation into myotubes. In addition, these cells secreted mature BMP-4, and BMP signaling could be inhibited with exogenous Noggin, causing a reduction in pSmad1/5/8, Id1, and Id3 levels. Confocal immunofluorescence microscopy revealed that activated Pax7+ myoblasts coexpressed nuclear pSmad1/5/8, Id1, and Id3 in injured mouse skeletal muscle sections. Although we did not observe differences in the numbers of quiescent Pax7+ satellite cells in adult uninjured hindlimb muscles, we did observe a significant reduction in the number of proliferating Pax7+ cells in the Id-mutant mice after muscle injury compared with either wild-type or Id3-null mice. These data suggest a model in which BMP signaling regulates Id1 and Id3 in muscle satellite cells, which directs their proper proliferation before terminal myogenic differentiation after skeletal muscle injury in postnatal animals

Potential role for Id myogenic repressors in apoptosis and attenuation of hypertrophy in muscles of aged rats

Aging attenuates the overload-induced increase in myogenic regulatory transcription factor (MRF) expression and the extent of muscle enlargement. To identify whether mRNA levels of repressors of the MRFs are greater in overloaded muscles from aged animals, overload was achieved in plantaris muscle of aged (33 mo; n = 14) and adult (9 mo; n = 17) rats. After 14 days, plantaris muscles in the overloaded limb were ~25% and 6% larger in adult and aged rats, respectively, compared with the contralateral limb. Hypertrophied muscles of adult rats had significantly greater levels of mRNA and protein levels for myogenin and MyoD compared with control muscles, but neither MRF increased with overload in muscles of aged rats. Muscles of aged rats had greater Id mRNA (150-700%) and protein repressor (200-6,000%) levels compared with adult rats. BAX and caspase 9 protein levels were 9,500% and 300% greater, respectively, in both control and hypertrophied muscles of aged rats compared with young adult rats. These data are consistent with the hypothesis that aging increases Id transcripts that activate apoptotic pathways involving BAX. This may contribute to sarcopenia by attenuating MRF protein levels in muscles of old animals

Peptide affinity chromatography based on combinatorial strategies for protein purification

We describe a method to develop affinity chromatography matrices with short peptide ligands for protein purification. The method entitles the following: a) synthesis of a combinatorial library on the HMBA-ChemMatrix resin by the divide-couple-recombine (DCR) method using the Fmoc chemistry, b) library screening with the protein of interest labeled with a fluorescent dye or biotin, c) identification of peptides contained on positive beads by tandem matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS/MS), d) solid phase peptide ligands synthesis and immobilization in chromatographic supports, e) evaluation of protein adsorption on peptide affinity matrices from the equilibrium isotherms and breakthrough curves.Fil: Camperi, Silvia Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Microbiología, Inmunología y Biotecnología. Cátedra de Microbiología Industrial y Biotecnología; ArgentinaFil: Martínez Ceron, María Camila. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Microbiología, Inmunología y Biotecnología. Cátedra de Microbiología Industrial y Biotecnología; ArgentinaFil: Giudicessi, Silvana Laura. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Microbiología, Inmunología y Biotecnología. Cátedra de Microbiología Industrial y Biotecnología; ArgentinaFil: Marani, Mariela Mirta. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Microbiología, Inmunología y Biotecnología. Cátedra de Microbiología Industrial y Biotecnología; ArgentinaFil: Albericio Palomera, Fernando. Universidad de Barcelona; EspañaFil: Cascone, Osvaldo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Microbiología, Inmunología y Biotecnología. Cátedra de Microbiología Industrial y Biotecnología; Argentin

Developing professional identity in health professional students

Professional identity formation is a relatively new area of interest within health professional education, gaining academic attention after the Carnegie Foundation Report on Medical Education of 2010 called for its introduction into medical curricula in the United States. This chapter presents a critical discussion, introducing various schools of thought, and provides theoretically informed suggestions for practice. The authors explore both conventional identity formation and more complex modern reconfigurations of healthcare professional identity. The chapter starts with an overview of different stances on what professional identity means, drawing on a variety of literatures including sociological and organizational scholarship. Next, a range of theories of identity formation are presented, including socialization and transformation. A matrix model is introduced to inform curricular planning, which can be used flexibly within different institutions or contexts. The authors discuss and critique a number of focused strategies for educators including role modeling, mentoring, reflective practice, responding to the hidden curriculum, authentic role experiences and simulation-based education, communities of practice and activity theory, student engagement, and assessment practices. The chapter concludes with possible future directions in healthcare professional identity education. Kathleen Leedham-Green is a research fellow in the Medical Education Research Unit at Imperial College London with interests in the social and behavioral aspects of clinical practice as well as healthcare innovation and quality. Alec Knight is a postdoctoral researcher and educator at King’s College London with interests in health services research, applied psychology, medical education, public health, health policy, and implementation science. Rick Iedema is professor and director of the Centre for Team-Based Practice and Learning in Health Care at King’s College London