64 research outputs found

    The Impact of a GenCyber Camp on In-service Teachers’ TPACK

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    The purpose of this study was to examine the impact of a GenCyber camp curriculum on teachers’ technology, pedagogy, and content knowledge (TPACK). The camp was designed to engage participants in developing the knowledge and skills to incorporate GenCyber Cybersecurity First Principles and GenCyber Cybersecurity Concepts (GenCyber, 2019) into their curriculums. Participants (37 middle and high school teachers from a variety of disciplines) attended one of two weeklong camps held at a Midwestern liberal arts university. Using the TPACK Self-Reflection and TPACK Self-Assessment Surveys, pre- and post-camp data were collected from participants. Findings indicate that participants demonstrated an increase in all domains of the TPACK framework from pre- to post-survey. The greatest increase was in Technological Pedagogy Knowledge (TPK) (0.57), followed by Pedagogical Content Knowledge (PCK) (0.51), and Technological Pedagogical Content Knowledge (TPACK) (0.46). GenCyber participants also demonstrated an average increase in pre- and post-test scores in all areas on the TPACK Self-Assessment Survey Results; however, individual results were mixed. The majority of participants (n=21), sixty percent, saw an increase in composite score from pre- to post, whereas 12 participants\u27 (34%) scores decreased from pre- to post, and two (6%) stayed the same. Findings indicate the GenCyber Camp provided in-service teachers with the knowledge and skills necessary to incorporate GenCyber Principles and Cybersecurity Concepts into their curriculum. Recommendations for teacher professional development on cybersecurity are made

    The Evolution of Hypertension: old genes, new concepts

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    Hypertension is known as the “silent killer,” driving the global public health burden of cardiovascular and renal disease. Blood pressure homeostasis is intimately associated with sodium balance and the distribution of sodium between fluid compartments and within tissues. On a population level, most societies consume 10 times more salt that the 0.5 g required by physiological need. This high salt intake is strongly linked to hypertension and to the World Health Organization targeting a ∼30% relative reduction in mean population salt intake to arrest the global mortality due to cardiovascular disease. But how does a habitually high-salt diet cause blood pressure to rise? In this focused review, we discuss 2 “evolutionary medicine” concepts, presented at the ISN Forefront Meeting “Immunomodulation of Cardio-renal Function.” We first examine how ancestral variants in genes that conferred a selection advantage during early human development are now maladaptive. We then discuss the conservation of “renal” sodium transport processes across multiple organ systems, including the brain. These systems influence sodium appetite and can exert an often-overlooked effect on long-term blood pressure control

    Dissociation of sodium-chloride cotransporter expression and blood pressure during chronic high dietary potassium supplementation

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    Dietary potassium (K+) supplementation is associated with a lowering effect in blood pressure (BP), but not all studies agree. Here, we examined the effects of short- and long-term K+ supplementation on BP in mice, whether differences depend on the accompanying anion or the sodium (Na+) intake and molecular alterations in the kidney that may underlie BP changes. Relative to the control diet, BP was higher in mice fed a high NaCl (1.57% Na+) diet for 7 weeks or fed a K+free diet for 2 weeks. BP was highest on a K+-free/high NaCl diet. Commensurate with increased abundance and phosphorylation of the thiazide sensitive sodium-chloride-cotransporter (NCC) on the K+-free/high NaCl diet, BP returned to normal with thiazides. Three weeks of a high K+ diet (5% K+) increased BP (predominantly during the night) independently of dietary Na+ or anion intake. Conversely, 4 days of KCl feeding reduced BP. Both feeding periods resulted in lower NCC levels but in increased levels of cleaved (active) α and γ subunits of the epithelial Na+ channel ENaC. The elevated BP after chronic K+ feeding was reduced by amiloride but not thiazide. Our results suggest that dietary K+ has an optimal threshold where it may be most effective for cardiovascular health

    Investigation of the Proteolytic Functions of an Expanded Cercarial Elastase Gene Family in Schistosoma mansoni

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    Schistosome parasites are a major cause of disease in the developing world. The larval stage of the parasite transitions between an intermediate snail host and a definitive human host in a dramatic fashion, burrowing out of the snail and subsequently penetrating human skin. This process is facilitated by secreted proteases. In Schistosoma mansoni, cercarial elastase is the predominant secreted protease and essential for host skin invasion. Genomic analysis reveals a greatly expanded cercarial elastase gene family in S. mansoni. Despite sequence divergence, SmCE isoforms show similar expression profiles throughout the S. mansoni life cycle and have largely similar substrate specificities, suggesting that the majority of protease isoforms are functionally redundant and therefore their expansion is an example of gene dosage. However, activity-based profiling also indicates that a subset of SmCE isoforms are activated prior to the parasite's exit from its intermediate snail host, suggesting that the protease may also have a role in this process

    Glucocorticoids regulate mitochondrial fatty acid oxidation in fetal cardiomyocytes

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    Abstract: The late gestational rise in glucocorticoids contributes to the structural and functional maturation of the perinatal heart. Here, we hypothesized that glucocorticoid action contributes to the metabolic switch in perinatal cardiomyocytes from carbohydrate to fatty acid oxidation. In primary mouse fetal cardiomyocytes, dexamethasone treatment induced expression of genes involved in fatty acid oxidation and increased mitochondrial oxidation of palmitate, dependent upon a glucocorticoid receptor (GR). Dexamethasone did not, however, induce mitophagy or alter the morphology of the mitochondrial network. In vivo, in neonatal mice, dexamethasone treatment induced cardiac expression of fatty acid oxidation genes. However, dexamethasone treatment of pregnant C57Bl/6 mice at embryonic day (E)13.5 or E16.5 failed to induce fatty acid oxidation genes in fetal hearts assessed 24 h later. Instead, at E17.5, fatty acid oxidation genes were downregulated by dexamethasone, as was GR itself. PGC-1α, required for glucocorticoid-induced maturation of primary mouse fetal cardiomyocytes in vitro, was also downregulated in fetal hearts at E17.5, 24 h after dexamethasone administration. Similarly, following a course of antenatal corticosteroids in a translational sheep model of preterm birth, both GR and PGC-1α were downregulated in heart. These data suggest that endogenous glucocorticoids support the perinatal switch to fatty acid oxidation in cardiomyocytes through changes in gene expression rather than gross changes in mitochondrial volume or mitochondrial turnover. Moreover, our data suggest that treatment with exogenous glucocorticoids may interfere with normal fetal heart maturation, possibly by downregulating GR. This has implications for clinical use of antenatal corticosteroids when preterm birth is considered a possibility. Key points: Glucocorticoids are steroid hormones that play a vital role in late pregnancy in maturing fetal organs, including the heart. In fetal cardiomyocytes in culture, glucocorticoids promote mitochondrial fatty acid oxidation, suggesting they facilitate the perinatal switch from carbohydrates to fatty acids as the predominant energy substrate. Administration of a synthetic glucocorticoid in late pregnancy in mice downregulates the glucocorticoid receptor and interferes with the normal increase in genes involved in fatty acid metabolism in the heart. In a sheep model of preterm birth, antenatal corticosteroids (synthetic glucocorticoid) downregulates the glucocorticoid receptor and the gene encoding PGC-1α, a master regulator of energy metabolism. These experiments suggest that administration of antenatal corticosteroids in anticipation of preterm delivery may interfere with fetal heart maturation by downregulating the ability to respond to glucocorticoids

    Exosome signalling in the kidney

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    Urine contains exosomes originating from the circulation and all cells lining the urinary tract. Exosomes are a route of inter-cellular communication along the nephron potentially able to transfer of protein and/or RNA. It is not known whether this is a regulated process analogous to other cell-to-cell signalling systems. The aims of this study were to develop nanoparticle tracking analysis (NTA) as a technique to quantify exosomes in urine. Secondly, the hormonal regulation of exosome uptake in vitro and in vivo was investigated. Thirdly, exosome excretion in a central diabetes insipidus (DI) patient and a patient group after radiocontrast exposure was measured to investigate exosome excretion along the kidney in injury. Using the fluorescent capabilities of NTA, urinary exosomes were quantified in urine samples. NTA was able to detect changes in aquaporin 2 levels in vitro and in vivo. Storage conditions for human urinary exosomes were also optimised using NTA. A kidney cortical collecting duct cell line (CCDs) was used to model regulation of exosome uptake in vitro. CCDs were stimulated with desmopressin, a vasopressin analogue, and uptake of fluorescently-loaded or microRNA-loaded exosomes was measured. Desmopressin stimulated exosome uptake into collecting duct cells via V2 receptor stimulation. Intra-cellular uptake of exosomes was confirmed by microRNA specific mRNA down-regulation. Mechanistically, exosome uptake in response to desmopressin required cyclic AMP production, was mediated by clathrin-dependent endocytosis and was selective for exosomes from kidney tubular cells. In mice, fluorescently-loaded exosomes were systemically injected before and after administration of the V2 antagonist, tolvaptan, and urinary exosome excretion was measured. Basally, 2.5% of injected exosomes were recovered in urine; tolvaptan treatment resulted in a 5-fold increase. By combining antibodies to nephron segment-specific proteins with NTA we measured human urinary exosome excretion in central diabetes insipidus (DI) and after radiocontrast exposure (n=37). In DI, desmopressin reduced the excretion of exosomes derived from upstream glomerular and proximal tubule cells. In patients exposed to radiocontrast, urinary exosomes from the glomerulus were positively correlated with the tubular injury markers KIM- 1 and NGAL. These findings therefore show that tubular exosome uptake is a specific, hormonally regulated process that is reduced with injury. Physiologically, exosomes are a mechanism of inter-cellular communication; therapeutically, exosomes represent a novel vehicle by which RNA therapy could be targeted for the treatment of kidney disease

    Klf15 Is Critical for the Development and Differentiation of Drosophila Nephrocytes

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    Insect nephrocytes are highly endocytic scavenger cells that represent the only invertebrate model for the study of human kidney podocytes. Despite their importance, nephrocyte development is largely uncharacterised. This work tested whether the insect ortholog of mammalian Kidney Krüppel-Like Factor (Klf15), a transcription factor required for mammalian podocyte differentiation, was required for insect nephrocyte development. It was found that expression of Drosophila Klf15 (dKlf15, previously known as Bteb2) was restricted to the only two nephrocyte populations in Drosophila, the garland cells and pericardial nephrocytes. Loss of dKlf15 function led to attrition of both nephrocyte populations and sensitised larvae to the xenotoxin silver nitrate. Although pericardial nephrocytes in dKlf15 loss of function mutants were specified during embryogenesis, they failed to express the slit diaphragm gene sticks and stones and did not form slit diaphragms. Conditional silencing of dKlf15 in adults led to reduced surface expression of the endocytic receptor Amnionless and loss of in vivo scavenger function. Over-expression of dKlf15 increased nephrocyte numbers and rescued age-dependent decline in nephrocyte function. The data place dKlf15 upstream of sns and Amnionless in a nephrocyte-restricted differentiation pathway and suggest dKlf15 expression is both necessary and sufficient to sustain nephrocyte differentiation. These findings explain the physiological relevance of dKlf15 in Drosophila and imply that the role of KLF15 in human podocytes is evolutionarily conserve

    African-specific alleles modify risk for asthma at the 17q12-q21 locus in African Americans

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    BACKGROUND: Asthma is the most common chronic disease in children, occurring at higher frequencies and with more severe disease in children with African ancestry. METHODS: We tested for association with haplotypes at the most replicated and significant childhood-onset asthma locus at 17q12-q21 and asthma in European American and African American children. Following this, we used whole-genome sequencing data from 1060 African American and 100 European American individuals to identify novel variants on a high-risk African American-specific haplotype. We characterized these variants in silico using gene expression and ATAC-seq data from airway epithelial cells, functional annotations from ENCODE, and promoter capture (pc)Hi-C maps in airway epithelial cells. Candidate causal variants were then assessed for correlation with asthma-associated phenotypes in African American children and adults. RESULTS: Our studies revealed nine novel African-specific common variants, enriched on a high-risk asthma haplotype, which regulated the expression of GSDMA in airway epithelial cells and were associated with features of severe asthma. Using ENCODE annotations, ATAC-seq, and pcHi-C, we narrowed the associations to two candidate causal variants that are associated with features of T2 low severe asthma. CONCLUSIONS: Previously unknown genetic variation at the 17q12-21 childhood-onset asthma locus contributes to asthma severity in individuals with African ancestries. We suggest that many other population-specific variants that have not been discovered in GWAS contribute to the genetic risk for asthma and other common diseases

    Glucocorticoids and renal sodium transport:implications for hypertension and salt-sensitivity

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    The clinical manifestations of glucocorticoid excess include central obesity, hyperglycaemia, dyslipidaemia, electrolyte abnormalities and hypertension. A century on from Cushing's original case study, these cardinal features are prevalent in industrialized nations. Hypertension is the major modifiable risk factor for cardiovascular and renal disease and reflects underlying abnormalities of Na(+) homeostasis. Aldosterone is a master regulator of renal Na(+) transport but here we argue that glucocorticoids are also influential, particularly during moderate excess. The hypothalamic–pituitary–adrenal axis can affect renal Na(+) homeostasis on multiple levels, systemically by increasing mineralocorticoid synthesis and locally by actions on both the mineralocorticoid and glucocorticoid receptors, both of which are expressed in the kidney. The kidney also expresses both of the 11β-hydroxysteroid dehydrogenase (11βHSD) enzymes. The intrarenal generation of active glucocorticoid by 11βHSD1 stimulates Na(+) reabsorption; failure to downregulate the enzyme during adaption to high dietary salt causes salt-sensitive hypertension. The deactivation of glucocorticoid by 11βHSD2 underpins the regulatory dominance for Na(+) transport of mineralocorticoids and defines the ‘aldosterone-sensitive distal nephron’. In summary, glucocorticoids can stimulate renal transport processes conventionally attributed to the renin–angiotensin–aldosterone system. Importantly, Na(+) and volume homeostasis do not exert negative feedback on the hypothalamic–pituitary–adrenal axis. These actions are therefore clinically relevant and may contribute to the pathogenesis of hypertension in conditions associated with elevated glucocorticoid levels, such as the metabolic syndrome and chronic stress
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