bluuebunny/crossref_metadata_2025_split huggingface dataset:
Soluble VE‐cadherin disrupts endothelial barrier function via VE‐PTP/RhoA signalling
Authors: Knop Juna‐Lisa , Burkard Natalie , Flemming Sven , Schlegel Nicolas 
Published: May 2022

Increased levels of soluble VE‐cadherin fragments (sVE‐cadherin) have previously been linked to inflammation‐induced loss of endothelial barrier function. We hypothesized that sVE‐cadherin independent of pro‐inflammatory stimuli may be critically involved in the context of endothelial barrier dysfunction.Recombinant human sVE‐cadherin (extracellular domains EC1‐5) was generated and verified by sequencing and immunoblotting. Application of sVE‐cadherin on human dermal microvascular endothelial cells (HDMECs) dose‐dependently induced loss of endothelial barrier function as revealed by measurements of transendothelial electrical resistance (TER) and flux of 70 kDa FITC‐dextran across HDMEC monolayers. In an in vivo rat model i.v. application of sVE‐cadherin resulted in loss of endothelial barrier function and reduced microcirculatory flow, which was comparable to the conditions when bacterial Lipopolysaccharide (LPS) was applied in vivo. Immunofluorescence staining and western blot analysis revealed that the functional effects of sVE‐cadherin were paralleled by decreased expression of VE‐cadherin and reduction of α‐/ β‐/ γ‐/ δ‐catenin and tight‐junction associated protein ZO‐1 at the cell borders. VE‐protein tyrosine phosphatase (VE‐PTP) which is associated with VE‐cadherin under resting conditions was removed from the cell borders following application of sVE‐cadherin to HDMEC. These changes were accompanied by intercellular gap formation and increased stress fibers in the actin cytoskeleton. On a mechanistic level, sVE‐cadherin did not induce cell death but increased RhoA activity and reduced extracellular VE‐cadherin interaction as revealed by atomic force measurements. Rho‐kinase inhibitor Y27632 blocked all sVE‐cadherin‐induced effects on endothelial barrier function. Furthermore, VE‐PTP inhibitor AKB9778 attenuated both RhoA activation and all sVE‐cadherin‐induced effects.In summary, sVE‐cadherin disrupts endothelial barrier function by dismantling the VE‐cadherin complex at the cell border via VE‐PTP‐dependent RhoA activation. This points to a novel pathophysiological role of sVE‐cadherin in the context of endothelial barrier dysfunction in inflammation.
Cerebral Ischemic Reperfusion Increases Autotaxin Expression Elevating Brain Endothelial Permeability
Authors: Bhattarai Susmita , Sharma Sudha , Ara Hosne , Subedi Utsab , Li Chun , Sun Grace , Murov Milena , Bhuiyan Md. Shenuarin , Sun Hong , Miriyala Sumitra , Panchatcharam Manikandan 
Published: May 2022

IntroductionIschemic reperfusion during stroke treatment increases the pathological progression of stroke. Reperfusion with r‐TPA and mechanical thrombectomy applied to stroke patients increases the risk of intracerebral hemorrhage. In addition, various molecular signals initiated during ischemic reperfusion exacerbate the disease due to increased endothelial permeability. However, a detailed molecular therapeutic regimen with r‐TPA and mechanical thrombectomy could limit the detrimental effects and increase the survival rate. Lysophosphatidic acid (LPA) is a bioactive phospholipid regulated in physiological and pathological conditions. LPA is produced by the enzyme autotaxin (ATX). ATX and LPA have been observed to deteriorate physiological status in various diseases such as myocardial infarction, Alzheimer’s disease, liver fibrosis, neuropathic pain etc. In cerebral ischemic‐reperfusion, the ATX‐LPA axis could initiate the endothelium disruption.HypothesisIncreased ATX expression in endothelium disrupts the endothelial barrier by increasing LPA during ischemic‐reperfusion.MethodsTransient middle cerebral artery occlusion with 90 minutes of ischemia and 24 hours of reperfusion (I/R) was used as a stroke model in mice. LPA was analyzed with mass spectrometry and immunohistochemistry. AR‐2 probe fluorescence assay was used to measure ATX activity. Evans Blue Permeability in vivo was measured with an infrared imager. For the in‐vitro study, oxygen and glucose deprivation and reperfusion (OGDR) were carried out in mouse brain microvascular endothelial cells (MBMEC).ResultsATX enzymatic activity is prominently raised (P<0.01) in I/R mice compared to sham mice. Increased ATX activity coheres with the Evans Blue permeability in the mice brain. Simultaneously LPA levels are elevated (P<0.01) in I/R mice. LPA was increased in brain tissue along the vasculature, indicating an unfavorable role of ATX in maintaining endothelial integrity. LPA receptors expression was regulated following stroke with upregulation of LPAR1, LPAR2, LPAR5, and LPAR6 following I/R. Permeability measured in MBMEC showed that LPA treatment increased the permeability in a time and concentration‐dependent manner. ATX expression was increased (P<0.05) in MBMEC with OGDR suggesting ATX regulation in endothelial cells following ischemic‐reperfusion. LPA produced during the process can disrupt the blood‐brain barrier, increasing cerebral permeability.ConclusionAfter a stroke, enhanced LPA production by ATX can disrupt the blood‐brain barrier, leading to brain edema and neural cell damage followed by irreversible brain injury. Inhibition of the ATX‐LPA axis prospects to be a better therapeutic avenue for cerebral ischemic reperfusion.
Harness RNA‐binding protein HuR to boost Anti‐PD‐1 Immunotherapy in immunologically cold tumors
Authors: Zhang QI , Yang Zhe , Wu Xiaoqing , Wei Lanjing , Lan Lan , Xu Liang 
Published: May 2022

Cancer immunotherapy, especially those targeting the immune checkpoint PD‐1 and PD‐L1 has emerged as a revolutionizing treatment modality. Immune checkpoint inhibitors (ICIs)‐mediated anti‐tumor response depends on T cell capability of recognizing and killing tumor cells. ‘Hot’ tumors, which are characterized by the T cell infiltration, show a better response rate to immune checkpoint blockade (ICB) treatment. In contrast, ‘Cold’ tumors have a particularly low objective response rate (ORR) to ICB. In consideration of the durable and impressive responses observed in ‘hot’ tumors, it will be valuable to make an endeavor to turn immunologically cold tumors into hot tumors. The RNA‐binding protein HuR is a member of the embryonic lethal abnormal vision (ELAV) family that is overexpressed in a variety of cancers and promotes tumorigenesis by interacting with a subset of oncogenic mRNAs.In this study, we show the direct binding of HuR protein to PD‐L1 mRNA in multiple types of cells by Ribonucleoprotein immunoprecipitation (RNP‐IP) and further validated by RNA pulldown assay. We also show that PD‐L1 mRNA decay is greatly expedited in HuR‐knockout cells, which underlines the stabilization function of HuR on PD‐L1 transcripts. Immunoblotting results demonstrate that PD‐L1 protein expression level is decreased in HuR‐knockout cells while up‐regulated in HuR‐proficient cells in comparison with control. These data together clarify HuR is engaged in PD‐L1 post‐transcription regulation.Based on this mechanism, we develop a combination strategy using HuR inhibitors and anti‐PD1 antibody to overcome the limitation by regulating the tumor immune microenvironment.KH‐200 is a compound that disrupts the transportation of HuR from nuclear to cytoplasm. To test the combination strategy in vivo, we established the EMT6 syngeneic breast cancer model. After 4‐week treatment, the combination group shows great effects in inhibiting tumor growth and prolonging survival. The similar combination effect was further observed in Lewis lung syngeneic lung cancer model.In conclusion, we preliminarily explored the role of HuR in tumor immune evasion. The method using HuR inhibitors as a combination in immunotherapy shows an effective in immunologically cold tumor treatment and may have reference significance for clinical cancer therapy.
Hepatic Arterial Patterns and Variations: Using CT Data Visualization Software to Decrease Procedural Complications Due to Hepatic Arterial Variations
Authors: Krueger Christopher , Withnell Charles B. 
Published: May 2022

IntroThree‐dimensional (3D) models have recently been used in pre‐operative planning in rare, complex surgeries in many disciplines. The goal of this study was to determine the efficacy of using 3D models in common procedures that involve increased risk of injury to hepatic arteries in the biliary region. This would allow surgeons to plan around individual variation and prevent intra‐operative complications in these regions. This study focuses on the feasibility of converting computed tomography (CT) scans into 3D models to identify anatomical variation and compares the results to the published rates of anatomical variation for the structures considered.MethodsA total of 27 (n=27) CT scans of healthy individuals were obtained from the Cancer Imaging Archive and digitally segmented with Dragonfly and the 3D Slicer software using the semi‐automated grow from seeds tool. The results were then manually reviewed and edited for accuracy. The liver, gall bladder, and spleen were segmented as well as the associated hepatic arterial vasculature: celiac trunk, splenic artery, left gastric artery, common hepatic artery, gastroduodenal artery, proper hepatic artery, right and left hepatic arteries, and the superior mesenteric artery. The segmented scans were then converted to a 3D model where they were classified using the CRL classification system which has a 99.8% classification rate.ResultsAll 3D models were classified into a CRL classification type. Nineteen (n=19) models were classified as Type 1, two (n=2) models as Type 2, one (n=1) model as Type 3, one (n=1) model as Type 4, two (n=2) models as Type 5, one (n=1) model as Type 9, and one (n=1) model did not fit under the classification system and remained unclassified. Previously published data was used to calculate the statistical expected value of each CRL type. A chi‐square analysis was performed to determine if the dataset fit normal patterns of variation. The results of the statistical test were statistically different χ2=0.0008 than previously published patterns of anatomical variation due to the rare unclassifiable variant.ConclusionThe study showed that it is feasible to use pre‐operative CT scans to reconstruct 3D models that can be used to identify variant anatomy pre‐operatively to assist in the planning of complex surgeries. The 3D slicer software did not require a computer with substantial hardware requirements and is able to be used on a personal computer. This means it is not necessary to purchase special equipment to implement in the hospital and could potentially allow physicians to explain procedures to patients in clinics outside of hospitals. In order to expand on the capabilities of pre‐operative 3D models, it is necessary to investigate more automated methods to accurately segment the appropriate anatomy.
Application of a Second‐Order Control‐Systems Model to Investigate Effects of Impaired Capillary Signalling in Skeletal Muscle on Regulation of Capillary Blood Flow Velocity and Tissue Oxygenation
Authors: Afas Keith C. , Goldman Daniel 
Published: May 2022

Microcirculation is the main region of the vasculature where oxygen (O2) is transferred directly from blood to metabolically active tissue. Tissue O2 partial pressure (PO2) in the microcirculation has been historically infeasible to measure, but critical as an indicator of capillary and surrounding tissue health. Thus, theoretical modelling of capillary‐tissue O2 transport is crucial as a complement to in vivo experiments in exploring structure‐function relationships in microvascular networks (Ellis et al, Microcirc 2012, 19:5). To properly complement experiments which stimulate O2 flow‐dependent regulation systems, modelling of microcirculatory O2 transport requires incorporation of knowledge on regulatory mechanisms.Capillary networks modulate their blood velocity to recruit sufficient O2 delivery in many local O2 conditions; this has led to the conclusion that endothelium signals upstream to arterioles in an O2‐dependent manner (Ghonaim et al, Microcirc 2021, e12699). Recently, a second‐order control systems model was developed to investigate the interaction between capillary‐tissue O2 transport and O2‐dependent blood flow regulation under an externally applied O2 stimulus. This utilized elements from previous arteriolar diameter alteration models in response to skeletal muscle O2 gradients, as well as elements from a recently developed continuous‐capillary O2 transport model (Afas et al, Math Biosci 2021, 333:108535).The control systems model aimed to predict modulations in blood velocity through endothelial signalling which homogenized outlet capillary PO2 in skeletal muscle. The model demonstrated that variations in O2 transport parameters such as capillary network density and tissue O2 consumption rate had varying effects on the averaged blood velocity in a small skeletal muscle segment perfused by a capillary network. In addition, the externally supplied PO2 had an effect on both blood velocity and the tissue‐capillary O2 balance. While the tissue‐capillary PO2 balance and velocity adaptation were investigated, the endothelial signalling parameters were not reported (Afas & Goldman, Vasc. Bio. 2021, conference).The present study investigates implications of capillary network metric variations on the endothelial signal communicated upstream to modulate capillary blood flow in response to various muscle surface PO2 levels. Constraints imposed by pathogenic impairment of endothelial signalling will be investigated and interpreted in the context of capillary flow regulation.
N6‐Methyladenosine (m6A) Modifies Regenerative Transcripts in the Intestinal Epithelium
Authors: Danan Charles H. , Hayer Katharina E. , Simon Lauren A. , Weitzman Matthew D. , Hamilton Kathryn E. 
Published: May 2022

BackgroundThe intestinal epithelium forms a critical barrier between foreign antigens in the intestinal lumen and immune cells in the underlying mucosa. This barrier is compromised in inflammatory bowel disease (IBD), resulting in inflammation and epithelial cell death. Improved understanding of intestinal epithelial regeneration would identify novel therapeutic targets to enhance epithelial barrier repair in diseases such as IBD. After injury, tissues such as the blood, skeletal muscle, and central nervous system activate a regenerative program that is partially regulated by N6‐methyladeonsine (m6A) modification of RNA. However, few data exist regarding the role of m6A within the intestinal epithelium. The goal of this study was to profile m6A‐modification transcriptome‐wide in the regenerating intestinal epithelium. We hypothesize that after injury, m6A promotes regeneration within the intestinal epithelium by modifying transcripts important in epithelial repair.MethodsWildtype mice were given dextran sodium sulfate (DSS) in drinking water to induce intestinal inflammation and epithelial cell loss. Control mice were provided untreated water. DSS was followed by a two‐week washout period to allow for regenerating epithelium to appear adjacent to areas of epithelial ulceration. After DSS washout, regenerating intestinal epithelium was isolated by flow cytometry, RNA was extracted, and m6A‐modified transcripts were immunoprecipitated and sequenced (m6A‐seq).Resultsm6A‐seq yielded ~5500 total m6A‐modified sites within the regenerating intestinal epithelium. This corresponded to 314 m6A‐modified mRNAs that were unique to the regenerating as compared to the homeostatic epithelium. These unique transcripts were enriched for pathways involved in RNA transcription and processing, cell‐cell junctions, and Hippo pathway signaling, all of which have previously been implicated in intestinal epithelial regeneration.Conclusions. Our data support the hypothesis that m6A modifies many transcripts with known roles in intestinal epithelial regeneration. Ongoing studies are evaluating how m6A modification contributes to regulation of these transcripts and whether m6A identifies transcripts with previously unknown roles in regeneration. We are also evaluating whether m6A is required for optimal regeneration following epithelial injury.
Prenatal E‐Cigarette Use Disrupts Blood‐Brain Barrier (BBB) Integrity and Induces Pro‐Inflammatory Cytokines in Postnatal Brain
Authors: Rahman Archie Sabrina , Sifat Ali Ehsan , Villalba Heidi , Sharma Sejal , Nozohouri Saeideh , Zhang Yong , Abbruscato Thomas 
Published: May 2022

PurposeElectronic cigarette (e‐Cig) is often considered as a safer alternative to smoking for pregnant women however, its potential toxic effect on neonatal health warrants further investigation. Toxic effects of prenatal tobacco smoking on postnatal health have been reported in several studies however, regarding thorough investigation of e‐Cig exposure during pregnancy is currently unavailable. Due to the staggering growth in e‐Cig usage among pregnant women (10%), it has become critical to explore the consequences of maternal e‐cig use on postnatal health outcomes. Hence, in this study, we have evaluated the consequences of prenatal e‐Cig use during pregnancy on postnatal blood‐brain barrier (BBB) integrity, proinflammatory cytokine levels and behavioral outcomes in offspring.MethodPregnant CD1 mice (E5) were exposed to e‐Cig vapor (2.4% nicotine) till postnatal day (PD) 7. Weight of the offspring was measured up to PD 90. Nicotine and cotinine concentration in plasma and brain were measured in PD 7 offspring by LC‐MS/MS. The expression level of structural elements of the BBB including, tight junction proteins (ZO‐1, claudin‐5, occludin), astrocyte (GFAP), pericyte (PDGFRβ) and basement membrane (Laminin α1, Laminin α4) were analyzed in offspring using western blot and immunohistochemistry at PD 7, PD 23, PD 45 and PD 90. The expression level of pro‐inflammatory cytokines (IL‐1α, IL‐1β, IL‐2, IL‐4, IL‐5, IL‐6, IL‐7, IL‐10, IL‐12, IL‐17α, KC, LIX, MIP‐2 and TNF‐α) in brain were measured at PD 7 and PD 90. To evaluate behavioral outcomes, open field test, novel object recognition test and morris water maze test were performed on adolescent and adult offspring.ResultsReduced body weight was observed in e‐Cig exposed offspring at all time points till PD 90 compared to control (P <0.05). Plasma concentration of nicotine and cotinine in PD 7 offspring was 3.215 ng/mL and 3.373 ng/mL respectively whereas in brain, these two concentrations were 43.72 ng/mL and 1.123 ng/mL respectively. Significantly reduced expression of brain tight junction proteins and GFAP were observed in male and female offspring at PD 7, PD 23, PD 45 and PD 90 (P <0.05). Moreover, higher level of brain IL‐1α, IL‐6, IL‐7, IL‐10, IL‐17α, KC and TNF‐α was found in prenatally e‐cig exposed offspring at PD 7. However, only IL‐6 and IL‐17α were observed at higher levels in brain for prenatally e‐cig exposed adult offspring at PD 90 (P <0.05). Additionally, disrupted motor, learning and memory function were observed in prenatally e‐Cig exposed adolescent and adult offspring.ConclusionOur findings suggest that prenatal e‐Cig exposure induces potential neurotoxic effects on neonates by disrupting postnatal blood‐brain barrier integrity and inducing proinflammatory brain cytokines which may result in alteration in neurological, cerebrovascular, and behavioral outcomes.
Identification and functional analysis of variants in ISL1 promoter from patients with isolated atrial septal defects
Authors: Yin Xiu‐Yun , Chen Huan‐Xin , Chen Zhuo , Han Jun , Yang Qin , He Guo‐Wei 
Published: May 2022

ObjectiveAtrial septal defect (ASD) is one of the most common types of congenital heart disease (CHD). As a transcription factor, ISL1 is expressed specifically in second heart field during embryogenesis and plays a crucial role in heart development and cardiovascular morphogenesis. Studies have shown association of ISL1 multiple variants with diverse type of CHD including ASD, whereas the variants of ISL1 gene promoter region in ASD patients have not been reported. We hypothesized that variants in ISL1 promoter may be involved in the formation of ASD.MethodsBlood samples from 593 subjects, including 300 patients with isolated ASD and 293 healthy controls were studied. Total DNA from all subjects was extracted and the PCR combined with Sanger sequencing was used to identify ISL1 gene promoter variants. Functional analysis of DNA sequence variants was performed using a dual luciferase reporter assay. Electrophoretic mobility shift assay (EMSA) was selected to examine the influence of the variants in ISL1 gene promoter on binding of transcription factors. All possible binding sites of transcription factor influenced by the identified variants were predicted by the PROMO database.ResultsFour variants in ISL1 gene promoter were found only in patients with ASD by sequencing. Three of the 4 variations [g.4923 G>C (rs541081886), g.5079 A>G (rs1371835943), g.5309 G>A (rs116222082)] significantly decreased the transcriptional activities compared with the wild‐type ISL1 gene promoter (P < 0.05). The EMSA revealed that these variants [g.4923 G>C (rs541081886), g.5079 A>G (rs1371835943), g.5309 G>A (rs116222082)] in ISL1 promoter affected the number and affinity of binding sites of transcription factors. Further analysis with the online PROMO database demonstrated that a cluster of putative binding sites for transcription factors may be altered by these variants.ConclusionThese sequence variants identified from the promoter region of ISL1 gene in ASD patients are likely involved in the development of ASD by affecting the transcriptional activity and altering ISL1 levels. Therefore, these findings may provide new insights into the molecular etiology and potential therapeutic strategy of ASD.
Communicating Science at 24 fps
Authors: Khadria Ambalika S. , Rajan Ranga 
Published: May 2022

Video storytelling is a powerful way to share science with the research community and general public. Films can illustrate complex scientific concepts and democratize access to high quality science. In this work, we describe three categories of films created by us in collaboration with students, postdocs and principal investigators. First, behind‐the‐scenes videos of in‐progress experiments, shot in the lab and annotated with relevant context, provide global audiences with a candid view of the scientific process and personas. Second, promotional films created for well‐defined R&D stakeholder groups such as academic departments and graduate programs serve to highlight research philosophies, core values and technical strengths. Third, showcase videos on state‐of‐the‐art instrumentation facilities enable leadership and potential donors to appreciate shared‐resource models that exemplify collaboration and facilitate ambitious research programs. These videos address important goals for the research community such as faculty/student recruiting, fundraising and science advocacy. The biomedical research community would be well‐served in its overarching goals by embracing films as essential components of an increasingly complex science communication ecosystem.At KathASK Films, we combine more than 25 years of life sciences research experience with a passion for creative art and storytelling to produce impactful science videos. Our interdisciplinary background in basic research and sensitivity towards under‐represented attributes such as gender bias, racial disparity and mental health stigma allows us to weave the science and its underlying human element into engaging stories.