Species-Specific Transcriptional Regulation of Genes Involved in Nitric Oxide Production and Arginine Metabolism in Macrophages

Activated mouse macrophages metabolize arginine via NO synthase (NOS2) to produce NO as an antimicrobial effector. Published gene expression datasets provide little support for the activation of this pathway in human macrophages. Generation of NO requires the coordinated regulation of multiple genes. We have generated RNA-sequencing data from bone marrow–derived macrophages from representative rodent (rat), monogastric (pig and horse), and ruminant (sheep, goat, cattle, and water buffalo) species, and analyzed the expression of genes involved in arginine metabolism in response to stimulation with LPS. In rats, as in mice, LPS strongly induced Nos2, the arginine transporter Slc7a2, arginase 1 (Arg1), GTP cyclohydrolase (Gch1), and argininosuccinate synthase (Ass1). None of these responses was conserved across species. Only cattle and water buffalo showed substantial NOS2 induction. The species studied also differed in expression and regulation of arginase (ARG2, rather than ARG1), and amino acid transporters. Variation between species was associated with rapid promoter evolution. Differential induction of NOS2 and ARG2 between the ruminant species was associated with insertions of the Bov-A2 retrotransposon in the promoter region. Bov-A2 was shown to possess LPS-inducible enhancer activity in transfected RAW264.7 macrophages. Consistent with a function in innate immunity, NO production and arginine metabolism vary greatly between species and differences may contribute to pathogen host restriction

Macrophage colony-stimulating factor (CSF1) controls monocyte production and maturation and the steady-state size of the liver in pigs

Macrophage colony-stimulating factor (CSF1) is an essential growth and differentiation factor for cells of the macrophage lineage. To explore the role of CSF1 in steady-state control of monocyte production and differentiation and tissue repair, we previously developed a bioactive protein with a longer half-life in circulation by fusing pig CSF1 with the Fc region of pig IgG1a. CSF1-Fc administration to pigs expanded progenitor pools in the marrow and selectively increased monocyte numbers and their expression of the maturation marker CD163. There was a rapid increase in the size of the liver, and extensive proliferation of hepatocytes associated with increased macrophage infiltration. Despite the large influx of macrophages, there was no evidence of liver injury and no increase in circulating liver enzymes. Microarray expression profiling of livers identified increased expression of macrophage markers, i.e., cytokines such as TNF, IL1, and IL6 known to influence hepatocyte proliferation, alongside cell cycle genes. The analysis also revealed selective enrichment of genes associated with portal, as opposed to centrilobular regions, as seen in hepatic regeneration. Combined with earlier data from the mouse, this study supports the existence of a CSF1-dependent feedback loop, linking macrophages of the liver with bone marrow and blood monocytes, to mediate homeostatic control of the size of the liver. The results also provide evidence of safety and efficacy for possible clinical applications of CSF1-Fc

Aggressive juvenile fibromatosis of the paranasal sinuses: case report and brief review

Desmoid fibromatoses are benign, slow growing fibroblastic neoplasms, arising from musculoaponeurotic stromal elements. Desmoids are characterized by local invasion, with a high rate of local recurrence and a tendency to destroy adjacent structures and organs. Desmoid fibromatoses are rare in children, and though they may occur in the head and neck region, are extremely rare in the paranasal sinuses. Here we report a case of extraabdominal desmoid fibromatosis in a seven-year-old boy involving the sphenoid sinus, one of only six published reports of desmoid fibromatosis of the paranasal sinuses. The expansile soft tissue mass eroded the walls of the sphenoid sinus as well as the posterior ethmoid air cells extending cephalad through the base of the skull. We discuss the clinicopathologic features of this lesion, including structural and ultrastructural characteristics, and we review the literature regarding treatment and outcome

Genomic epidemiology of SARS-CoV-2 in a UK university identifies dynamics of transmission

AbstractUnderstanding SARS-CoV-2 transmission in higher education settings is important to limit spread between students, and into at-risk populations. In this study, we sequenced 482 SARS-CoV-2 isolates from the University of Cambridge from 5 October to 6 December 2020. We perform a detailed phylogenetic comparison with 972 isolates from the surrounding community, complemented with epidemiological and contact tracing data, to determine transmission dynamics. We observe limited viral introductions into the university; the majority of student cases were linked to a single genetic cluster, likely following social gatherings at a venue outside the university. We identify considerable onward transmission associated with student accommodation and courses; this was effectively contained using local infection control measures and following a national lockdown. Transmission clusters were largely segregated within the university or the community. Our study highlights key determinants of SARS-CoV-2 transmission and effective interventions in a higher education setting that will inform public health policy during pandemics.</jats:p

Therapeutic potential for phenytoin : targeting Nav1.5 sodium channels to reduce migration and invasion in metastatic breast cancer

Voltage-gated Na(+) channels (VGSCs) are heteromeric membrane protein complexes containing pore-forming α subunits and smaller, non-pore-forming β subunits. VGSCs are classically expressed in excitable cells, including neurons and muscle cells, where they mediate action potential firing, neurite outgrowth, pathfinding, and migration. VGSCs are also expressed in metastatic cells from a number of cancers. The Na(v)1.5 α subunit (encoded by SCN5A) is expressed in breast cancer (BCa) cell lines, where it enhances migration and invasion. We studied the expression of SCN5A in BCa array data, and tested the effect of the VGSC-blocking anticonvulsant phenytoin (5,5-diphenylhydantoin) on Na(+) current, migration, and invasion in BCa cells. SCN5A was up-regulated in BCa samples in several datasets, and was more highly expressed in samples from patients who had a recurrence, metastasis, or died within 5 years. SCN5A was also overexpressed as an outlier in a subset of samples, and associated with increased odds of developing metastasis. Phenytoin inhibited transient and persistent Na(+) current recorded from strongly metastatic MDA-MB-231 cells, and this effect was more potent at depolarized holding voltages. It may thus be an effective VGSC-blocking drug in cancer cells, which typically have depolarized membrane potentials. At a concentration within the therapeutic range used to treat epilepsy, phenytoin significantly inhibited the migration and invasion of MDA-MB-231 cells, but had no effect on weakly metastatic MCF-7 cells, which do not express Na(+) currents. We conclude that phenytoin suppresses Na(+) current in VGSC-expressing metastatic BCa cells, thus inhibiting VGSC-dependent migration and invasion. Together, our data support the hypothesis that SCN5A is up-regulated in BCa, favoring an invasive/metastatic phenotype. We therefore propose that repurposing existing VGSC-blocking therapeutic drugs should be further investigated as a potential new strategy to improve patient outcomes in metastatic BCa

Proposed clinical pathway for nonoperative management of high-grade pediatric pancreatic injuries based on a multicenter analysis: A pediatric trauma society collaborative

Copyright © 2017 Wolters Kluwer Health, Inc. All rights reserved. BACKGROUND Guidelines for nonoperative management (NOM) of high-grade pancreatic injuries in children have not been established, and wide practice variability exists. The purpose of this study was to evaluate common clinical strategies across multiple pediatric trauma centers to develop a consensus-based standard clinical pathway. METHODS A multicenter, retrospective review was conducted of children with high-grade (American Association of Surgeons for Trauma grade III-V) pancreatic injuries treated with NOM between 2010 and 2015. Data were collected on demographics, clinical management, and outcomes. RESULTS Eighty-six patients were treated at 20 pediatric trauma centers. Median age was 9 years (range, 1-18 years). The majority (73%) of injuries were American Association of Surgeons for Trauma grade III, 24% were grade IV, and 3% were grade V. Median time from injury to presentation was 12 hours and median ISS was 16 (range, 4-66). All patients had computed tomography scan and serum pancreatic enzyme levels at presentation, but serial enzyme level monitoring was variable. Pancreatic enzyme levels did not correlate with injury grade or pseudocyst development. Parenteral nutrition was used in 68% and jejunal feeds in 31%. 3Endoscopic retrograde cholangiopancreatogram was obtained in 25%. An organized peripancreatic fluid collection present for at least 7 days after injury was identified in 59% (42 of 71). Initial management of these included: observation 64%, percutaneous drain 24%, and endoscopic drainage 10% and needle aspiration 2%. Clear liquids were started at a median of 6 days (IQR, 3-13 days) and regular diet at a median of 8 days (IQR 4-20 days). Median hospitalization length was 13 days (IQR, 7-24 days). Injury grade did not account for prolonged time to initiating oral diet or hospital length; indicating that the variability in these outcomes was largely due to different surgeon preferences. CONCLUSION High-grade pancreatic injuries in children are rare and significant variability exists in NOM strategies, which may affect outcomes and effective resource utilization. A standard clinical pathway is proposed. LEVEL OF EVIDENCE Therapeutic/care management, level V (case series)

Proposed clinical pathway for nonoperative management of high-grade pediatric pancreatic injuries based on a multicenter analysis: A pediatric trauma society collaborative

Copyright © 2017 Wolters Kluwer Health, Inc. All rights reserved. BACKGROUND Guidelines for nonoperative management (NOM) of high-grade pancreatic injuries in children have not been established, and wide practice variability exists. The purpose of this study was to evaluate common clinical strategies across multiple pediatric trauma centers to develop a consensus-based standard clinical pathway. METHODS A multicenter, retrospective review was conducted of children with high-grade (American Association of Surgeons for Trauma grade III-V) pancreatic injuries treated with NOM between 2010 and 2015. Data were collected on demographics, clinical management, and outcomes. RESULTS Eighty-six patients were treated at 20 pediatric trauma centers. Median age was 9 years (range, 1-18 years). The majority (73%) of injuries were American Association of Surgeons for Trauma grade III, 24% were grade IV, and 3% were grade V. Median time from injury to presentation was 12 hours and median ISS was 16 (range, 4-66). All patients had computed tomography scan and serum pancreatic enzyme levels at presentation, but serial enzyme level monitoring was variable. Pancreatic enzyme levels did not correlate with injury grade or pseudocyst development. Parenteral nutrition was used in 68% and jejunal feeds in 31%. 3Endoscopic retrograde cholangiopancreatogram was obtained in 25%. An organized peripancreatic fluid collection present for at least 7 days after injury was identified in 59% (42 of 71). Initial management of these included: observation 64%, percutaneous drain 24%, and endoscopic drainage 10% and needle aspiration 2%. Clear liquids were started at a median of 6 days (IQR, 3-13 days) and regular diet at a median of 8 days (IQR 4-20 days). Median hospitalization length was 13 days (IQR, 7-24 days). Injury grade did not account for prolonged time to initiating oral diet or hospital length; indicating that the variability in these outcomes was largely due to different surgeon preferences. CONCLUSION High-grade pancreatic injuries in children are rare and significant variability exists in NOM strategies, which may affect outcomes and effective resource utilization. A standard clinical pathway is proposed. LEVEL OF EVIDENCE Therapeutic/care management, level V (case series)