bluuebunny/crossref_metadata_2025_split huggingface dataset:
Probing the crosslinking independent roles of tissue transglutaminase in vascular aging using a novel transamidation‐deficient TGM2‐C277S mouse model
Authors: Santhanam Lakshmi , Chen James , Melucci Sean , Jandu Sandeep , Nandakumar Kavitha , Wang Huilei , Barreto-Ortiz Sebastian 
Published: April 2020

IntroductionTissue transglutaminase (TG2) is a multifunctional protein of the transglutaminase family with putative transamidation‐independent functions in aging associated vascular stiffening and dysfunction. The development of preclinical models is critical to fully understand the physiological relevance of transamidation independent functions of TG2 and to identify the specific function of TG2 for therapeutic targeting. Therefore, In this study we harnessed the CRISPR‐Cas9 gene editing technology to introduce a mutation at the active site cysteine (C277) in the mouse TGM2 gene.Methods and resultsWe investigated the contributions of the transamidation‐dependent vs. transamidaiton‐independent functions of TG2 in vascular aging using TGM2‐C277S mice, littermate WT mice, and age‐matched TG2−/− mice. Heterozygous and homozygous TGM2‐C277S mice were phenotypically normal and were born at the expected Mendelian frequency. TG2 protein abundance was similar to wild‐type (WT) in the TGM2‐C277S mutant mice in the liver, lung, heart, aorta, and kidney. GTP binding, and interactions with fibronectin and integrin beta1 were preserved in the TG2‐C277S mouse protein. Transglutaminase function was absent in the TG2 protein from TGM2‐C277S mice when compared with wild‐type (WT) littermates. Loss of transamidation function resulted in a marked loss in serotonin induced vasoconstriction and in vitro remodeling of the carotid artery in response to chronic vasoconstriction. On the other hand, cell adhesion and proliferation were comparable to that of WT in the vascular smooth muscle cells from TGM2‐C277S but not in those from TG2−/− mice. Vascular stiffness increased with age in WT mice, as measured by pulse wave velocity, tensile testing, and pressure myography. TGM2‐C277S mice were markedly protected from age‐associated vascular stiffening, but not to the same extent as TG2−/− mice.ConclusionsTogether, these studies show that the TGM2‐C277S mice ubiquitously express a TG2 protein that lacks transamidation function and retains its other functions and can be used a tool for in vivo studies to examine the transamidation‐independent roles of TG2 in physiology and pathophysiology. While TG2‐mediated ECM crosslinking and VSMC dysfunction, both propagate vascular stiffening in aging, the transamidation function is the primary shareholder in aging associated mechanical decline of the large vessels.Support or Funding InformationThis work was funded by a StAAR Investigator Award (to LS) and a MedImmune Research Funds Award (to LS).
Endothelial shear stress in the common carotid artery during boxing training in prehypertension
Authors: Gomez Manuel , Morales-Acuna Francisco , Rodriguez Lisa , Caraveo Paulina , Gurovich Alvaro N. 
Published: April 2020

PURPOSEEndothelial function is highly regulated by the friction between blood flow and the endothelium. Endothelial shear stress (ESS) is defined as the dragging force generated by this interaction and it has been reported that low ESS affects nitric oxide bioavailability which in turn might increase blood pressure. Exercise programs are one of the best suited approaches to treat high blood pressure, however, there are no studies describing changes on ESS in the common carotid artery during upper‐body exercise, such as boxing training. Therefore, the purpose of this study was to quantify ESS in the common carotid artery during 60% and 95% of the maximal boxing exercise capacity in normotensive and pre‐hypertensive subjects.METHODSA total of 5 healthy normotensive and 5 pre‐hypertensive subjects matched by age, gender, height, and weight were recruited for this study. All 10 subjects performed two boxing exercise tests. The first was a graded maximal boxing test to estimate their maximal oxygen uptake (VO2max). The second one, performed 48 hours after the first evaluation, was a 2‐workload steady‐state boxing test at 60%VO2max and at 95%VO2max for 3 minutes each. A high‐definition Doppler ultrasound recorded common carotid artery diameters and blood flow velocities throughout each steady‐state condition. ESS was estimated using Womersley’s approximation.RESULTSThere was a significant increase in antegrade ESS with higher workloads in both groups (p < 0.05 for all). No difference were found in anterograde ESS at baseline (Normotensive: 33.9±13.9 dynes/cm2, Pre‐HTA: 34.7±5.5 dynes/cm2; p = 0.936), at 60%VO2max (Normotensive: 51.3±19.1 dynes/cm2, Pre‐HTA: 49.6±7.6 dynes/cm2; p = 0.894, and at 95%VO2max (Normotensive: 72.9±30.9 dynes/cm2, Pre‐HTA: 85.2±12.5 dynes/cm2; p = 0.560) between both groups. Meanwhile, no retrograde blood flow was present at baseline for either groups, but it was identified at 60%VO2max (Normotensive: 8.1±0.7 dynes/cm2, Pre‐HTA: 7.8±7.8 dynes/cm2; p = 0.971) and 95%VO2max (Normotensive: 22.5±18.9 dynes/cm2, Pre‐HTA: 20.8±5.6 dynes/cm2; p = 0.891).CONCLUSIONESS increases in an exercise‐intensity manner during boxing training in normotensive and prehypertensive population. Boxing training might be beneficial in high blood pressure prevention due to increments on ESS.
Investigating the role of the mesentery in the innervation of the gut and enteric nervous system during embryological development ‐ an immunohistochemistry approach
Authors: McDermott Kieran , Cronin Fiona , Coffey Calvin 
Published: April 2020

Recent clarification of mesenteric anatomy has indicated that, unlike classical descriptions, the intestines are enveloped in a continuous, rather than a fragmented mesentery. This has prompted a need to re‐examine its development and it anatomical relationships with the developing gastrointestinal tract(GIT). Advances in understanding the development of the mesenteric tissues has also highlighted its potential role as a facilitator of neural crest cell migration during enteric nervous system development. Furthermore spatial and temporal differences in the nature of the mesentery may influence how the different regions of the GIT develop.The aim of this research is to describe the development of the mesentery, gut and enteric nervous system independently and subsequently determine how each of these components relates to each other during development. Of particular interest is clarifying the manner in which efferent and afferent autonomic fibres develop, traverse the mesentery and, ultimately innervate the gut and the enteric nervous system. Histological and immunohistochemical approaches are being employed to highlight autonomic axons and mesenteric components of rat tissue at different embryonic ages. Animal procedures were in accordance with Republic of Ireland Department of Health and Children license. Immunohistochemical analysis of serially sectioned rat embryos at embryonic days 12, 14 and 16 is being undertaken, which will allow detailed microscopic confirmation of the continuous mesenteric structure, arising from its primitive mesodermal framework, and will illuminate the process underpinning how autonomic fibres are distributed to the GIT. A further objective is to advance this study of mesenteric development in rodent tissue to human embryonic tissue and, ultimately, to describe key molecular determinants of mesenteric‐directed axonal pathfinding. This will address the paucity of information available on the development and anatomical course of peripheral nerves through the mesentery in the human. An understanding of the developmental innervation of the mesentery and gut has implications for advancing knowledge of normal anatomy as well as relevant pathological states such as Hirschsprung’s Disease.
Dietary iron modulates fecal microbiota and severity of enterotoxigenic E. coli infection in a weanling pig model
Authors: Ji Peng , Li Chong , Kim Byeonghyeon , Jinno Cynthia Nanako 
Published: April 2020

BackgroundEnterotoxigenic E. coli (ETEC) infection is among the leading causes of diarrhea in young children who live in resource‐limited countries, wherein iron deficiency anemia is usually more prevalent. It is debated whether iron supplementation increases the risk of enteric infection.Objectivethe study used a weanling piglet model to investigate the effect of dietary iron on severity of ETEC infection and host microbiota.MethodsThirty‐two weaned piglets were blocked by body weight and randomized to the treatments. Pigs were fed 1) an iron‐replete diet (150 mg iron/kg) and received sham inoculation (CON), 2) a low‐iron diet (54 mg iron/kg) and orally inoculated with ETEC (LOI), 3) the iron‐replete diet and orally inoculated with ETEC (COI), or 4) a high‐iron diet (700 mg elemental iron /kg) and orally inoculated with ETEC (HII). Pigs were individually housed with free access to water and diets. After 10 days adaptation to diet, pigs were orally inoculated with a 3‐mL dose of F18+ ETEC (1010 cfu) or sterile saline solution for 3 days. Alertness and fecal consistency were scored daily since day 0 post‐inoculation (d0PI). Fecal samples were collected for 16S RNA sequencing and examining the presence of pathogen. Data was analyzed using PROC MIXED of SAS (v.9.4) with repeated measures for variables measured over time.ResultsPathogen was positive in fecal samples from inoculated pigs on d3PI, but was absent in most pigs on d6PI. Pigs in LOI had lower hemoglobin and hematocrit compared to those in HII before ETEC infection (P < 0.05), but dietary iron content did not affect growth before infection. Enterotoxigenic E. coli infection reduced hemoglobin and hematocrits compared to CON, but only pigs in LOI had significantly retarded growth after infection (P < 0.05). There were more days of diarrhea (fecal score > 2) in LOI than in CON and COI (P < 0.05). Treatment did not affect alpha‐diversity on d0 or d7PI. Relative abundance of Actinobacteria and Firmicutes were affected by treatment on d7PI. Within the phylum of Actinobacteria, Bifidobacteriaceae was more abundant in LOI (37.3%) than that in CON (2.0%) and HII (5.0%), while the opposite pattern was observed for Coriobacteriaceae. Within the phylum of Firmicutes, Lactobacillaceae had the greatest abundance in LOI (28.8% and 31.7%) in comparison with all the other groups (7.8% – 17.7%) on d0 and d7PI (P < 0.05). Same pattern was observed for Veillonellaceae, while Clostridiaceae had the highest abundance in HII (22.8%) and the lowest in LOI (5.7%) on d7PI (P = 0.07).ConclusionIron deficiency predisposed host to increased vulnerability to ETEC infection in weanling pigs. Both iron‐deficient and iron‐excess diet alters fecal microbiota with more prominent effect post‐ETEC infection.Support or Funding InformationNIFA hatch project
Manipulating PrP Glycan Structure to Understand Toxic Signaling Pathways Driving Prion‐Induced Neurodegeneration
Authors: Callender Julia A. , Sevillano Alejandro M. , Soldau Katrin , Khuu Helen , Aguilar-Calvo Patricia , Sigurdson Christina J. 
Published: April 2020

Prion proteins cause an infectious and rapidly progressive neurodegenerative disease characterized by an exponential increase in prion aggregates as well as spongiform encephalopathy, dystrophic neurites, and neuronal death. These processes depend on the neuronal expression of prion protein (PrPC), which exists on the outer leaflet of the cell membrane as a glycosylphosphatidylinositol (GPI)‐anchored glycoprotein containing two variably occupied N‐linked glycosylation sites on its carboxy terminus. Previous work has shown that glycan modifications may impact PrP aggregation and neuronal toxicity. To further investigate the role of glycans in prion‐induced neurotoxicity, we have engineered a new knockin mouse model that expresses PrP with an additional glycan on its amino terminus. This mouse spontaneously develops neurodegeneration characterized by spongiform encephalopathy. In contrast to other murine models of prion disease, this neurodegenerative pathology develops in the absence of PrP aggregates or infectivity, as shown by RT‐QuIC, ThT fluorescence, and inoculation of wild‐type mice with brain homogenates from the knockin mouse. Therefore, this model provides the opportunity to investigate the neurotoxic role of PrPC, uncoupled from its aggregation. We show that although the extra glycan does not affect PrPC expression, stability, or turnover in cells, the brains of mice display alterations in autophagy signaling proteins. We are currently further defining the N‐linked glycans on PrPC, with the goal of understanding how glycans mediate the neurotoxic functions of prion protein. These studies hold relevance not only to diseases of prion aggregation, but also to neurodegenerative diseases characterized by protein aggregation in general, including Alzheimer’s, Parkinson’s, and Huntington’s Disease.Support or Funding InformationThis work was supported by NIH NS15498 awarded to Christina Sigurdson, and by the National Heart, Lung, and Blood Institute of the National Instituters of Health under K12HL141956. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.
Oxygen Consumption and Substrate Oxidation Rates Following Passive Acclimation to a Hot Environment
Authors: Etter Clara Vada , Beaudin Andrew E. , Walsh Michael L. , White Matthew D. 
Published: April 2020

IntroductionAcclimation to a hot environment via prolonged or repeated, daily exposure to a heat stress results in adaptations of the human thermoregulatory responses. In this study, it was investigated whether metabolic responses to passive heat acclimation (HA) adapted similarly to thermoregulatory heat loss responses including following a 10‐day, 2 h·day−1 passive heat acclimation (HA) to 50°C and 20 % RH. This study was approved by the Simon Fraser University Office of Research Ethics.PurposeIt was hypothesized that, similar to that seen during active heat acclimation with exercise, there would be an elevation of oxygen consumption following a passive heat acclimation. It was also hypothesized that following heat acclimation there would be increased lipid oxidation relative to the pre‐acclimation state.MethodsNine male participants performed two immersions in a 40°C bath separated by a 10‐day passive heat acclimation. Heat acclimation was performed in a climatic chamber controlled at 50°C and 20 % RH where participants remained seated at rest for 2 hr·day−1 with their rectal temperature maintained between 38.5 – 39.0°C. A two‐way repeated measures ANOVA with factors of Acclimation State (Pre and Post) and delta TES (0 to 1.4°C above rest) was employed with post hoc analysis completed with two‐tailed, paired t‐tests. The significance level was p<0.05.ResultsHA was confirmed by a significant decrease in resting esophageal temperature (TES) from 37.60 ± 0.19 (mean ± SD) to 37.31 ± 0.11°C (p=0.001). During the 40°C immersions significant decreases in the TES thresholds for temple cutaneous blood velocity from 37.34 ± 0.12 to 37.14 ± 0.16°C (p=0.008) and for forehead eccrine sweating from 37.61 ± 0.21 to 37.24 ± 0.24°C (p=0.007) also confirmed heat acclimation. HA did not influence oxygen consumption from 0.21 ± 0.07 to 0.22 ± 0.07 L/min (p=0.15). Carbohydrate oxidation rate increased from 0.21 ± 0.21 to 0.28 ± 0.26 g·min−1 (p=0.002). Lipid oxidation rate decreased from 1.16 ± 0.22 to 1.09 ± 0.24 g·min−1 (p<0.001).ConclusionFollowing a passive heat acclimation the evidence reports no change in oxygen consumption, and contrary to that hypothesized, there was a decrease in lipid oxidation rate and an increase in carbohydrate oxidation rate.Support or Funding Information Funding SourceThis project was supported by Natural Sciences and Engineering Research Council of Canada and the Canada Foundation for Innovation.
IL‐4 Stimulated Macrophages Induce a Pro‐Inflammatory Secretome in Fibroblasts
Authors: Julian Dana Rose , Buechel Heather , Kulkarni Mangesh , Ismail Nahed , Brown Bryan , Yates Cecelia C. 
Published: April 2020

The precis continuum manifold of cell state of macrophages and fibroblast cells during skin fibrosis, described as a chronic inflammatory and tissue remodeling microenvironment, is not well understood. Both cell populations respond directly to damage and present a coordinated chain of activation states that dictates the reparative outcome. The spectrum change in phenotype during late remodeling is important, because it is by both cells that autocrine and paracrine communication contribute to the deposition of extracellular matrix (ECM) and chronic inflammation. Here, we provide evidence that the anti‐inflammatory M2‐like (IL‐4 induced) macrophage cell state drives activated fibroblasts to secrete important pro‐inflammatory mediators and thus changing the fibroblast cell state to one that promotes a continuous fibrotic milieu. Indirect and direct co‐culture systems were used to elevate the effects paracrine and autocrine feedback of secreted factors and cell‐contact dependent factors. These studies showed the exposure of TGF‐β‐activated fibroblasts to M2‐like macrophages altered the cytokine/chemokine secretion profile of fibroblasts to express IL‐1β, TNFα, and CXCL10 and enhanced its expression of profibrotic matrix production by using transcriptomic analysis. To understand the necessity of fibroblast‐macrophage crosstalk in the fibrotic process a gain of function approach was used by reconstituting the mice with IL‐4 polarized macrophage in an in vivo sterile wound/fibrosis bleomycin model. Tissue fibroblasts increased expression of pro‐inflammatory cytokines included IL‐10, INF‐γ, and IL‐13, as confirmed by transcriptomic analysis. These analyses additionally identified an imbalance in proteolytic remodeling actions of TIMPs and MMPs. These findings identify an important role of macrophage‐specific cell state and phenotype‐directed crosstalk with tissue remodeling activated fibroblast in signaling to orchestrate a chronic inflammatory and fibrotic microenvironment.Support or Funding InformationThis work was supported by NIH grants R01AR68317, R01AG055564, and R01GM121558.
Behavioral and histopathological examination of antidepressant‐like effect of Vitamin D in rats
Authors: Filali Houda , Kadil Youness , Agoub Mohamed 
Published: April 2020

Exposure to repetitive stressful life situations is clearly associated with the onset of depression. Convergent evidence demonstrates that vitamin D has surprisingly diverse functions in the Nervous central system. The aim of the present study is to investigate the behavioral and the histopathological effect of Vitamin D in rats been exposed to the Unpredictable Chronic Mild Stress.Twenty‐four rats were randomly divided into three groups of eight received respectively Nacl, Vit D (200 UI/kg/day) and Fluoxetine (10mg/kg/day) intraperitoneally during 6 weeks. All animals were exposed to various stressful situations, with a frequency of two stressors per day throughout the 5‐weeks. Forced swim test and histopathological evaluation were used to evaluate the antidepressant potential effect of vitamin D versus fluoxetine.The administration of Vitamin D daily reduces significantly the immobilization time during the forced swim test versus the control groupe (p=0.003). The histopathological analysis showed that supplementation by vitamin D prevent against apoptosis by a significant reduction of apoptotic neurons. Vitamin D provides a significant protective effect against neuronal loss and cellular disorganization at the hippocampus.The interpretation of our results supports our theory which suggest the antidepressant‐like effect of Vitamin D. Other investigations in the same field are being conducted to demonstrate the mechanisms of action involved in this approach
Unraveling the Pathology of the Blood‐Tumor Barrier in an Experimental Model of Brain Metastases of Lung Cancer
Authors: Auld Claudine , Reddy Alexandra , Uzunalli Gozde , Dieterly Alexandra , Lyle L. Tiffany 
Published: April 2020

Lung cancer is the leading cause of cancer‐related deaths worldwide (1.76 million deaths in 2018) and the leading cause of brain metastatic disease among all primary cancers. As tumor cells colonize the neuroparenchyma, they breach the tightest and most effective vascular barrier in the body, the blood‐brain barrier (BBB). The functional components of the BBB include endothelial cells, basement membranes, pericytes and astrocytes. Herein, we hypothesized that dynamic transformation of the BBB to the blood‐tumor barrier (BTB) would correlate with changes in paracellular permeability. An experimental model of lung cancer brain metastases was developed using twelve 6‐week‐old athymic nude mice. Mice were injected with 250,000 brain‐seeking cells, which colonized the brain for 4–6 weeks. Animals were injected with 3 kd Texas Red dextran at the time of euthanasia, and brains were harvested, cryosectioned and prepared for immunofluorescence analysis. Metastatic tumors were characterized as highly or poorly permeable based on the diffusion of Texas Red dextran within and around the tumor parenchyma. Brain metastases were roughly spherical and measured between 50–500 μm in diameter, irrespective of their permeability status. The most striking BTB pathology was identified in tight junctions and associated adapter proteins. Highly permeable tumors exhibited haphazard expression of claudin‐5 and a loss of zona occludens‐1 adapter protein compared to metastases with low paracellular permeability. Understanding the cellular and molecular alterations occurring within the BBB during brain metastatic disease from non‐small cell lung cancer is imperative for the identification of novel therapeutic targets and improved methods of drug delivery.Support or Funding InformationClaudine Auld was supported by the Summer Research Opportunities Program, sponsored by the American Society of Investigative Pathology. This research was supported in part by the Showalter Research Trust.
Angiotensin‐Converting Enzyme I/D Polymorphism on Hematological Changes after Marathon Race
Authors: Cury-Boaventura Maria Fernanda , Rogante Julliane Izidoro , Sierra Ana Paula Renno , Oliveira Rodrigo Assunção , Lima Giscard Humberto Oliveira , Benetti Marino Pereira , Kiss Maria Augusta , Pesquero João Bosco 
Published: April 2020

The aim of this study was to determine the influence of ACE I/D polymorphisms on hematological changes induced by marathon race. One hundred and eleven Brazilian amateurs’ male endurance runners participated in the study. Blood samples and urine were collected before, immediately after, one, three and fifteen days after the marathon race. Urine (hematuria), hematological parameters (erythrocytes, hemoglobin, Hb, hematocrit, Ht, red blood cell distribution width, RDW, mean corpuscular volume, MCV, mean corpuscular hemoglobin, MCH, and mean corpuscular hemoglobin concentration, MCHC) and ACE I/D genotyping analyses were performed. Immediately after the race we observed hematuria in ID and DD genotypes but not in II genotypes. The marathon induced a decrease in erythrocyte counts and hematocrit; and an increase in MCV one and three days after marathon in ID and DD genotypes, but there was no change in athletes with genotype II. There was also a reduction of hemoglobin 3 days after the marathon in genotypes ID and DD, but there was no significant change in genotype II runners. We observed an increase in RDW and CHCM three and fifteen days after the marathon, respectively, in runners with genotype ID, suggesting compensation for a reduction in the number of erythrocytes. ACE II genotype has a protective role on hematological changes induced by marathon avoiding the risk of athletic anemia and acute renal failure.Support or Funding InformationThis work was supported by Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) [Grant Number 2014/21501‐0].