bluuebunny/crossref_metadata_2025_split huggingface dataset:
Primary roles for human neutrophil Fc receptors in the initiation of nephrotoxic glomerulonephritis
Authors: Tsuboi Naotake , Mayadas Tanya 
Published: June 2021

Antibody‐antigen complexes promote inflammatory and autoimmune diseases. Mice deficient in γ‐chain of Fc‐receptors are protected in antibody mediated glomerulonephritis and lupus nephritis and FcR‐bearing macrophages have been implicated as the primary initiators of disease. However, how well studies of diseases mediated by murine receptors accurately reflect human inflammation remains unclear. Here we show that neutrophil selective transgenic expression of the two uniquely human FcγRIIA and FcγRIIIB in γ‐chain deficient mice (IIA+IIIBtg/γ−/−) was sufficient to promote progressive glomerulonephritis associated with glomerular neutrophil accumulation, glomerulosclerosis, macrophage and T cell accumulation, renal failure and mortality. These responses far exceeded those in wild‐type mice despite similar expression levels of activating receptors suggesting that the human and mouse FcγRs are not functionally equivalent. Both FcγRIIIB and FcγRIIA promoted robust neutrophil recruitment while FcγRIIA alone mediated tissue injury. The latter was consistent with the robust adhesion dependent H2O2 production in IIAtg/γ−/− and the lack there of in IIIBtg/γ−/ −. Thus, human neutrophil FcγRs serve as molecular links between immune complexes and renal injury suggesting a new paradigm for FcγRs on neutrophils in the initiation of antibody mediated‐glomerulonephritis.Funded by HL065095, AR050800 and Arthritis Foundation Postdoctoral Fellowship.
Creutzfeldt‐Jakob Disease in the Baltimore, Maryland Area: A Recent Survey
Authors: Gonzalez‐Cuyar Luis Francisco , Morrison Alan L , Castellani Rudy J 
Published: June 2021

Objective: To provide an overview of cases of Creutzfeldt‐Jakob disease (CJD) referred to the University of Maryland for autopsy.Methods: Autopsy tissue from subjects with CJD over two years was obtained and dissected per standard protocol. Routine histopathology, PrP immunohistochemistry, Western blot, and PrP gene analysis were performed. Results: Ten biochemically confirmed cases of CJD were identified. Age ranged from 51 to 77 years of age (5 male, 5 female). All were consistent with sporadic disease, with molecular phenotyping according to Parchi et al (Ann Neurol 1999 Aug;46(2):224‐33). 5 subjects had the classic phenotype (MM1); 3 had the kuru plaque variant (MV1), 1 had the ataxic phenotype (VV2), and 1 had the cortical phenotype (MM2). Of note, one subject had premorbid Parkinsonâ€™s disease, confirmed pathologically. A second subject (age 51) was an intravenous drug user who shared needles with an individual who expired from an uncharacterized neurological decline. No atypical clinical, pathological, or molecular features were noted. Conclusion: A recent survey of subjects with CJD in the Baltimore area demonstrated sporadic cases only, and a typical distribution of molecular phenotypes. One subject was had premorbid Parkinsonâ€™s disease, while a second subject was an intravenous drug user. Whether the latter comprises a significant risk factor for CJD awaits further study.
Cystatin C: A potential surrogate biomarker in amyotrophic lateral sclerosis
Authors: Wilson Meghan E. , Darko Samuel , Lacomis David , Bowser Robert 
Published: June 2021

Amyotrophic lateral sclerosis (ALS) is a fatal neurological disease characterized by progressive motor neuron degeneration. Currently, disease management is hindered by a lengthy diagnostic process which is based heavily on clinical criteria. A reliable panel of biomarkers is needed in order to accelerate the diagnosis of this disease and aid in monitoring its progression. We have previously reported proteomic evidence supporting a reduction of Cystatin C protien levels in the cerebrospinal fluid (CSF) of ALS patients relative to controls. In this study, we have evaluated the potential of Cystatin C as a diagnostic and/or prognostic biomarker by assessing its expression over the course of disease progression. We used a quantitative ELISA to evaluate Cystatin C concentration in both CSF and plasma at multiple time points following ALS symptom onset. Cystatin C levels in both fluids were found to correlate strongly with clinical measures of disease progression. This correlation was maintained during transient functional improvements observed in some patients during drug trial participation. Additionally, expression patterns were observed to vary between specific subpopulations of ALS patients. These data support the utility of Cystatin C as both a diagnostic biomarker and a surrogate biomarker for monitoring disease progression and treatment response.Funded by: University of Pittsburgh Center for ALS Research
Animal models to investigate lung inflammation induced following exposure to swine barn air
Authors: Charavaryamath Chandrashekhar , Podborochynski Rachel , Janardhan Kyathanahalli S , Juneau Vanessa , Suri Sarabjeet Singh , Townsend Hugh , Singh Baljit 
Published: June 2021

Modern swine barns house large number of pigs in confined buildings. The barn air contains microbes, dust, gases and endotoxin. Swine farmers experience loss of lung function and suffer from respiratory diseases. Exposure of naïve volunteers to swine barn air has shown to induce of lung inflammation and increased airway hyperresponsiveness (AHR) whose mechanisms remain unclear.We exposed rats to either swine barn or ambient air for eight hours per day for 1, 5 or 20 days. Following 20 day exposure and either 2 or 5 week recovery, rats were challenged either with saline or lipopolysaccharide. We measured AHR and lung inflammation. Exposure to barn induced AHR, mucus‐positive airway epithelial cells and lung inflammation while prolonged exposure dampened the AHR. Following barn exposures and recovery, rats showed lung inflammation with an increased intensity following lipopolysaccharide challenge.To clarify the role of Toll‐like receptor 4 (TLR4) in inducing lung inflammation and AHR, we exposed C3HeB/FeJ (intact TLR4, WT) and C3H/HeJ (defective TLR4, mutant) mice in a similar pattern. Both strains showed increased and dampened AHR following 5 and 20 exposures respectively while barn exposure induced lung inflammation in WT but not in mutant mice to show different roles of TLR4 in lung inflammation and AHR (CIHR's strategic training grant in PHARE and Lung Association of Saskatchewan).
Can we encourage our graduate students to develop a more scholarly approach to classroom teaching?
Authors: O'Loughlin Valerie Dean , Braun Mark , Kearns Katherine Dowell , Heacock Isaac 
Published: June 2021

Previous research indicates that graduate courses in pedagogical methods produce specific teaching behaviors in the short term. However, little assessment has been done to examine how teaching behaviors and attitudes endure over time. Assessments of pedagogy courses should continue well past the completion of the course, in order to determine the persistence and ongoing development of the students' perceptions of teaching and learning. Indiana University faculty members Valerie O'Loughlin and Mark Braun developed and team‐taught a three credit hour pedagogy course (M620: Pedagogical Methods in the Health Sciences) to prepare graduate students to be reflective and scholarly teachers. They examined the impact of the course on how well graduate students:
* Develop more complex and refined attitudes regarding student learning;
* Evaluate their current teaching methods and explore alternative teaching strategies;
* Practice methods of assessment and evaluation; and
* Plan to be involved in a public teaching resource network, such as teaching workshops or a scholarship of teaching and learning program.
Data examined include students' teaching philosophy statements, teaching portfolios, pre‐ and post‐course surveys, and course evaluations. In addition, data from a six‐month follow‐up student interview was used to examine the lasting and ongoing influence the course has on graduate student attitudes about teaching and learning. The results of this study should contribute to the literature on short‐term and longer‐term effects of these courses on the development of future faculty.This research was funded, in part, by an Indiana University Scholarship of Teaching and Learning Grant.
Polypeptide from 7S soy globulin alpha' subunit up‐regulates LDL‐receptors in HepG2 cells
Authors: Lovati Maria Rosa , Manzoni Cristina , Pizzagalli Anna , Castiglioni Silvia , Duranti Marcello Maria 
Published: June 2021

7S soy globulin and its alpha’ subunit have been shown to positively modulate LDL receptor activity and to decrease triglyceride synthesis both in vitro and in vivo. The aim of the study was to evaluate the effect of a short chain of alpha’ (S‐alpha’) from 7S globulin, on cell cholesterol homeostasis. HepG2 cells were incubated in the presence/absence of alpha’ subunit (3.5.10−6M) or the S‐alpha’ at concentration of 10−5 M and 10−6 M. A dose‐dependent increase in up‐regulation of LDL‐receptors has been detected in cells exposed to S‐alpha’ vs that found in controls. Moreover, the 125I‐LDL uptake (+ 192%) and degradation (+ 143%) of cells exposed to the highest dose of S‐alpha’ (8.10−6M) were similar to that found in cells incubated with 1 mM simvastatin; these results were confirmed by a dose‐dependent increase in the SREBP2 and LDL‐receptor mRNAs. Hep G2 cells exposed to S‐alpha’ for 24 h showed an increased uptake of fluorescent LDL vs both alpha’ and controls as detected by fluorescence microscopy: the fluorescence intensity was proportional to the amount of LDL uptaked by the cells as confirmed by FACS analysis.These findings open new prospects in the studies aimed at identifying the regulatory peptide/s from soybean proteins and the mechanism/s involved in this biological response, in view of their potential utilization in the management of human lipid disorders.Supported in part by a grant of MIUR of Italy.
Activation of anabolic signal transduction pathways in L6 muscle cells in response to Amino Acids (AA) and Insulin
Authors: Patel Rekha , Smith Ken , Rennie Michael , Atherton Philip 
Published: June 2021

Muscle protein synthesis (MPS) in vivo is stimulated by feeding‐associated increases in AA and insulin. However, there is limited knowledge of their separate and common effects on signal transduction pathways regulating MPS. We aimed to measure the activation and temporal responses of signalling proteins to insulin, AA or their combination in vitro.After withdrawal of serum for 6h and of AA for 3h L6 cells were treated with either, AA (1× plasma concentration) or insulin (5 μIU/ml) alone, or a combination thereof. Proteins were extracted at intervals between 15–105 min. Activation of most proteins studied occurred by 15 min. Insulin stimulated PKB, mTOR, 4EBP1, eIF4G, eIF4B and eIF2Bε by >300% at all time‐points. AA alone only stimulated eIF2Bε phosphorylation by ~50%. Addition of AA with insulin potentiated peak insulin‐stimulated phosphorylation of PKB, p70 and 4EBP1 >200%. eEF2 was activated from 45 min onward.Insulin with or without AA induced rapid activation of growth pathways and their co‐provision augmented insulin‐induced phosphorylation events. Conversely, AA provision alone was insufficient, to induce anabolic signalling, except for eIF2Bε. Delayed activation of eEF2 may be indicative of its role in elongation and not initiation. To conclude, insulin is required for AA‐induced stimulation of MPS, and their co‐provision potentiates activation of signalling proteins regulating MPS.
Rho kinase mediates Helicobacter pylori ‐induced tight junctional claudin‐4 disruption in human gastric epithelial cells
Authors: Lapointe Tamia K , OiConnor Pamela M , Ménard Daniel , Buret André G 
Published: June 2021

Gastric epithelial barrier function is primarily maintained by tight junctions (TJ). Small Rho GTPases and Rho kinase (ROCK) are involved in TJ regulation. The ability of H. pylori (Hp) to subvert normal cellular pathways regulating TJ permeability may contribute to the development of gastric ulcers and adenocarcinomas. The mechanisms involved in Hp‐mediated junctional disruptions remain unclear.AIMThe aim of this study was to assess the role of ROCK in Hp‐induced TJ disruption, using a human gastric epithelial (HGE‐20) cell line.RESULTSImmunostaining/Western blotting and activity assays showed cytosolic translocation of claudin‐4 and a 50% increase in ROCK activity in infected monolayers. ROCK inhibition reduced loss of claudin‐4 from the membrane. Treatment of HGE‐20 with conditioned media failed to induce the Hp‐mediated increase in ROCK activity. Caspase‐3 and Rho GTPases Rac‐1 and RhoA activity was significantly increased post infection, consistent with their involvement in the signaling events leading to ROCK activation and claudin‐4 redistribution.CONCLUSIONThese findings demonstrate that Hp activates ROCK and its upstream effectors caspase‐3 and Rho GTPases. The mechanism by which Hp disrupts gastric epithelial barrier structure involves ROCK‐dependent redistribution of claudin‐4, independently of epithelial or bacterial secreted factors. This work was funded by CIHR.
Statins and rapamycin act synergistically to enhance vascular endothelial cytoprotection
Authors: Mason Justin Charles , Hamdulay Shahir , Ali Faisal , Ali Nadira , Haskard Dorian O 
Published: June 2021

Background: Heme oxygenase‐1 (HO‐1) and decay‐accelerating factor (DAF) are endothelial cytoprotective genes which limit vascular injury. Statins induce DAF, while rapamycin (Rap) upregulates HO‐1 expression. We asked whether statins and Rap act synergistically to enhance vasculoprotection.Methods & Results: Treatment of EC with atorvastatin (AT) 0.5μM and Rap 1.25μM led to a synergistic increase in DAF expression 24‐72h post‐treatment (>200%, p<0.05). AT + Rap‐induced DAF expression was dependent upon gene transcription and de novo protein synthesis. Functional relevance was revealed by enhanced protection against complement‐mediated EC lysis, when compared to treatment with Rap or AT alone (35% v 75% and 55% lysis respectively, p<0.05), with protection lost in the presence of DAF inhibitory mAbs. Mevalonate inhibited synergy, confirming a role for HMG‐CoA reductase inhibition. Of note, AT + Rap increased HO‐1 enzyme activity, while HO‐1 antagonist ZnPPIX attenuated, and HO‐1 agonist CoPP enhanced, the synergistic response. Experiments, using iron chelator DFO and ferritin overexpression, suggested that depletion of intracellular free Fe2+ and increased ferritin, a consequence of HO‐1‐activation, was central to synergy. Finally, although synergy was reproduced by simvastatin and Rap, no synergy was seen between atorvastatin and cyclosporine, mycophenolate or methotrexate.Conclusion: Treatment of EC with Rap and AT results in HO‐1‐dependent synergistic enhancement of DAF expression and protection against complement‐mediated injury. Combination therapies may provide the means to deliver immunosuppression and vasculoprotection for patients with systemic autoimmune diseases.
FGF mediates maintenance of vascular integrity in a Csk dependent manner
Authors: Murakami Masahiro , Zhuang Zhenwu , Moodie Karen , Stan Radu , Simons Michael 
Published: June 2021

Background: Maintenance of vascular integrity is one of the most fundamental vascular functions; however, its regulation is not well understood.Methods: To address the effect of FGF inhibition in adult vasculature, two mouse models were used: (1) endothelium‐specific transgenic expression of the dominant‐negative form of FGF‐R1 (FGF‐R1DN) under the tetracycline‐regulated Tie2 promoter and (2) adenovirus‐mediated systemic expression of soluble FGFR‐IgFc chimera proteins (Ad‐sFGFR). Results: Various in vivo studies demonstrated that inhibition of FGF signaling leads to: (1) disruption of EC adhesion and alignment and (2) increased vascular permeability in normal and ischemic tissues. In vitro studies confirmed that inhibition of FGF signaling increases EC monolayer permeability. This is accompanied with disappearance of VE‐cadherin and other junction proteins from cell‐cell contacts without changing total expression levels of these proteins or cell density/viability. Co‐immunoprecipitation experiments revealed disruption of FGF signaling led to decreased p120‐catenin and Csk association with VE‐cadherin. The absence of Csk in the VE‐cadherin complex can promote local Src activation which potentially leads to VE‐cadherin internalization and junction disassembly. In FGF‐R1DN EC, a VE‐cadherin mutant (Y685E) that constitutively binds Csk restored VE‐cadherin junction localization. This suggests that Csk recruitment to VE‐cadherin is critical for VE‐cadherin stabilization, and this process is regulated by FGF signaling.Conclusion: Maintenance of vascular integrity is a dynamic process requiring ongoing FGF signaling.
The adhesion molecule ICAM‐2 regulates contact inhibition in endothelial cells
Authors: RANDI ANNA MARIA , Amsellem Valerie , Dryden Nicola , Birdsey Graeme , Haskard Dorian , Mason Justin Charles 
Published: June 2021

Endothelial junctions play a key role in angiogenesis. ICAM‐2, constitutively expressed at endothelial junctions, mediates leukocyte recruitment and angiogenesis. The ICAM‐2 intracellular tail binds ERM proteins and α‐actinin. We generated an ICAM‐2 deficient line (δIC2) from mouse cardiac endothelial cells (EC), isolated from ICAM‐2 −/− mice by positive selection and immortalized with polyoma middle T. We also generated an over‐expressing line by infecting the δIC2 cells with a retroviral vector encoding for full‐length (FL) mouse ICAM‐2 (IC2FL), and two mutant ICAM‐2 lines, one lacking the intracellular tail (IC2δTL) and one where the ERM binding sites in the tail have been mutated (IC2δERM). δIC2 cells show defective in vitro angiogenesis on Matrigel, decreased cell migration and Rac activity; over‐expression of ICAM‐2 (IC2FL) reverses the phenotypes. Interestingly, IC2FL cells form a cobblestone monolayer at confluence and are contact‐inhibited whilst δIC2 cells grow and overlap, suggesting that ICAM‐2 is required for junction formation and contact‐dependent inhibition of cell growth. This involves signalling via ERMs, since mutants (IC2δTL) and (IC2δERM) also lack contact‐inhibition. Contact inhibition can be restored by over‐expressing constitutively active Rac (RacV12). Thus ICAM‐2 regulates EC growth and contact inhibition via signalling pathways involving ERMs and Rac.Research supported by the British Heart Foundation and the EU FP6 Network MAIN.
JAM‐A regulates epithelial integrin expression and cell shape by activation of Rap1a and Rap1b through a complex with Afadin and PDZ‐GEFs
Authors: Severson Eric A , Parkos Charles A 
Published: June 2021

Junctional adhesion molecule‐A (JAM‐A) is a tight junction protein implicated in the regulation of epithelial β1 integrin expression, cell shape and barrier function. We previously determined that this regulation requires both dimerization and PDZ binding motifs on different regions of JAM‐A. To gain further insight into JAM‐A mediated signaling in vitro, we downregulated expression of scaffolding proteins and found that loss of Afadin resulted in cellular changes similar to those observed with loss of JAM‐A. Immunofluorescence (IF) and immunoprecipitation (IP) studies revealed co‐association of Afadin with JAM‐A. Interestingly, the small GTPase Rap1 is known to interact with Afadin, regulate integrin function and have decreased activity after loss of JAM‐A. Downregulation of Rap1a resulted in decreased β1 integrin protein levels whereas loss of Rap1b resulted in altered cell shape. Since Rap1 activation is dependent on guanine nucleotide exchange factors (GEFs) we assessed expression of GEFs in vitro and identified PDZ‐GEF1 and PDZ‐GEF2 as major transcripts in colonic epithelia. IF and IP studies revealed co‐association of the PDZ‐GEFs with JAM‐A and loss of the PDZ‐GEFs resulted in diminished Rap1 activity. These results suggest that dimerized JAM‐A signals through a complex that may contain both Afadin and PDZ‐GEFs which, in turn, activate Rap1a and Rap1b to regulate β1 integrin levels and cell shape.Supported by NIH DK‐61379
Renal Inflammation in Response to Cholesterol Feeding in the ApoE Deficient Mouse Detected In Vivo by Molecular Nanobeacons Targeted to VCAM‐1
Authors: Zhang Huiying , Kaneda Megan , Zhang Lei , Southworth Rick , Chen Junjie , Lanzan Gregory M , Wickline Samuel A 
Published: June 2021

Atherosclerosis elicits kidney damage based on cholesterol‐macrophage response associated upregulated vascular cell adhesion molecule‐1 (VCAM‐1) expression. We employed a novel VCAM‐1 targeted fluorescent nanoparticles (NP) and immunochemistry to define the VCAM‐1 expression in apolipoprotein E deficient (ApoE−/−) mice kidney.Methods: ApoE−/− mice fed on a high cholesterol diet for 35 weeks were injected with VCAM‐1 targeted NP (n=6). Control groups were comprised ApoE−/− littermates treated with non‐targeted NP (n=5), C57/BL6 mice treated with VCAM‐1 targeted (n=5) and non‐targeted (n=6) NP. Mice were sacrificed two hours after treatment to allow NP binding to vascular VCAM‐1 receptors. Frozen sections of mouse kidneys were prepared for fluorescent imaging. Immunostaining of VCAM‐1 was performed on three ApoE−/− and three C57/BL6 mice kidneys.Results: Relative area with VCAM‐1 expression was significantly higher in ApoE−/− kidneys than that of controls (Fig. A, p<0.05). Fluorescent imaging revealed that VCAM‐1 targeted NP bound specifically to the glomeruls of ApoE −/− mice kidney (Fig. B) but not to that of controls (images not shown).Discussion: Upregulated VCAM‐1 in ApoE −/− mouse kidneys can be visualized with the targeted NP, suggesting VCAM‐1 targeted NP is a potential molecular imaging agent for early detection and monitoring of inflammation in renal disease.
IFN‐γ production by neutrophils during S. pneumoniae pneumonia requires NADPH oxidase
Authors: Gomez John C. , Yamada Mitsuhiro , Rebert Nancy A. , Doerschuk Claire M. 
Published: June 2021

Lung neutrophils produce interferon‐γ (IFN‐γ) in pneumonia induced by Streptococcus pneumoniae. The intracellular signals that control this process are not understood. Reactive oxygen species generated by NADPH oxidase can regulate intracellular pathways, including gene transcription in neutrophils. Our studies determined the role of NADPH oxidase in the production of IFN‐γ by neutrophils during pneumonia induced by S. pneumoniae. IFN‐γ production by neutrophils in the lungs of wild type (WT) and NADPH oxidase deficient (gp91phox −/−) mice 24 hours after intratracheal instillation of S. pneumoniae was determined by flow cytometry. The percentage of lung neutrophils that produced intracellular IFN‐γ was less in gp91phox −/− mice compared to WT mice (1.7 ± 0.1% vs. 23.8 ± 1.9% respectively, p<0.001). The total number of lung neutrophils was similar in WT and gp91phox −/− mice (19.7 ± 1.7 × 10 6 vs. 23.1 ± 3.5 × 106, respectively). Decreased IFN‐γ production in gp91phox −/− lung neutrophils was associated with elevated levels of activated JNK. Activation of p38 MAPK, ERK and NF‐κB was similar in WT and gp91phox−/− lung neutrophils. IFN‐γ production by neutrophils during S. pneumoniae pneumonia proceeds through signals that require NADPH oxidase and may contribute to host defense.Supported by HL052466.