bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Role of Angiotensin 1‐7 in Isolated Human Arterioles with SARS‐CoV‐2
Authors: Nishijima Yoshinori , Hader Shelby , Zhang David , Gutterman David , Beyer Andreas 
Published: May 2022

IntroductionThe vascular endothelium plays a crucial role to regulate vascular tone. Recently, our laboratory reported severe acute respiratory syndrome coronavirus‐2 (SARS‐CoV‐2) infection significantly reduced endothelial‐dependent vasodilation months after exposed to SARS‐CoV‐2 in human microvessels. SARS‐CoV‐2 enters host cells through angiotensin‐converting enzyme (ACE)2 as a cell surface receptor. Downregulation of ACE2 protein expression by the virus leads to imbalance between angiotensin (ANG) II and ANG 1‐7, causing vasoconstriction, inflammation and increase oxidative stress. With this background, we intend to test our new hypothesis that administration of ANG 1‐7 will improve vasodilation in human arterioles from previously SARS‐CoV‐2 positive subjects.MethodsFresh human tissues were obtained as de‐identified surgical discarded specimens. Control subjects (n=9) were SARS‐CoV‐2 negative and without known virus exposure. We had 11 previously SARS‐CoV‐2 positive subjects or post‐COVID. For all post‐COVID patients, a negative COVID test was obtained prior to collection of surgical specimens. We isolated arterioles (100‐200 µm) and cannulated onto glass micropipettes under 60 mmHg and examined for diameter changes to the endothelial‐dependent vasodilator acetylcholine (ACh; 10−9 to 10−5 M) using videomicroscopy. Flow‐mediated dilation (FMD) was recorded at steady‐state during varying intraluminal pressure gradients (5‐100 cm H2O). All post‐COVID vessels were incubated in a culture media at 37°C for 12–15 hours with or without 1 nM of ANG 1‐7.ResultsDilation to ACh and FMD in arterioles from post‐COVID was significantly reduced (ACh max. dilation at 10−5 M: 74±6% vs. 93±4% in control, n=7‐9, P<0.001; FMD max. dilation at 100 cm H2O: 49±3% vs. 86±2% in control, n=6‐11, P<0.001) while overnight incubation of 1 nM ANG 1‐7 significantly improved the dilation (ACh max. dilation at 10−5 M: 74±6% in post‐COVID vs. 88±5% in post‐COVID + AND 1‐7, n=11, P<0.001; FMD max. dilation at 100 cm H2O: 49±3% in post‐COVID vs. 76±3% in post‐COVID + ANG 1‐7, n=11, P<0.001).ConclusionAdministration of ANG 1‐7 significantly improved vasodilation in isolated arterioles from post‐COVID subjects.
Potassium Hydroxide Activated Titanium Dioxide Nanoparticles Diminishes Streptococcus mutans Biofilm Formation
Authors: Caudle K. , Morris M. , Bhalla S. , Kositangool P. , Falahati K. , Barragan J. , Hong B.Y. , Lee S. , Serizawa A. , Cervantes J. 
Published: May 2022

Dental caries represents one of the most common oral diseases. Streptococcus mutans is an oral bacterium involved in the process of caries development, forming a biofilm to promote bacterial adherence to the tooth surface and to other bacteria. Photocatalytically activated titanium dioxide (TiO2) has been shown to have antimicrobial properties on oral pathogens as well as on biofilm formation.We aimed to evaluate the effect of potassium‐incorporated TiO2 (KTiOx) nanostructures, a high performance photocatalyst, on biofilm formation by S. mutans.S.mutans was cultured in the presence of KTiOx 1M and 10M nanoparticles, as well as a elemental Ti control. Biofilm formation was assessed using a crystal violet biofilm formation after 24, 48, and 72 hours.A decrease in biofilm formation was observed in a dose response manner after 48 hours incubation with 32, 64, and 128 ug/mL of KTiOx.Our findings show that KTiOx nanoparticles have anti‐biofilm properties which may be applied to combat biofilm containing S.mutans, This novel approach may be a promising therapeutic alternative in caries prevention, though reduction of bacterial adhesion to dental surfaces.
In Silico Identification of a β2 Adrenergic Receptor Allosteric Site that Selectively Augments Canonical β2AR‐Gs Signaling and Function
Authors: Shah Sushrut D. , Lind Christoffer , De Pascali Francesco , Penn Raymond B. , MacKerell Alexander D. , Deshpande Deepak A. 
Published: May 2022

Objective & HypothesisActivation of β2‐adrenergic receptors (β2ARs) leads to airway smooth muscle (ASM) relaxation and bronchodilation. While this facilitates β2ARs agonists (β‐agonists) as the front‐line treatments for asthma and related obstructive airway diseases, their therapeutic efficacy of β‐agonists is limited by agonist‐induced β2AR desensitization and activation of non‐canonical β2AR signaling involving β‐arrestin. Accordingly, we undertook the identification of an allosteric site on β2AR and potential ligands, and ascertain their effects in‐vitro. We hypothesize that activation of specific allosteric site on β2AR could selectively modulate the activity of β‐agonists to overcome these limitations.MethodsWe employed the site identification by ligand competitive saturation (SILCS) computational method to map the entire 3D structure of an in silico‐generated β2AR intermediate conformation. Further, in‐silico database was screened to identify potential ligands using SILCS‐PHARM approach. Levels of cyclic‐AMP were used to assess activation of β2AR‐Gs activation using ELISA. Activation of downstream effector of cAMP, protein kinase A (PKA) was assessed by western blotting and luciferase assay. β‐arrestin recruitment to β2AR was assessed using Bioluminescence Resonance Energy Transfer (BRET) assay. ELISA and immunofluorescence were used to assess cell surface expression. Mutagenesis analysis was used to investigate the potential binding site for the allosteric modulators. Lastly, functional effects of the allosteric modulators were determined by assessing relaxation of human ASM cells embedded in 3D‐collagen gels and murine airways.ResultsDatabase screening using SILCS identified not only putative allosteric site but also potential drug‐like compounds that can bind to the site. Experimental assays in HEK293 cells and human ASM cells identified positive and negative allosteric modulators (PAM and NAM respectively) of β2AR as assessed by generation of cAMP. Co‐stimulation of cells with PAM or NAM modulated β‐agonist‐induced PKA activation. Allosteric modulators had no effect on β‐agonist‐induced recruitment of β‐arrestin to β2AR or β‐agonist‐induced loss of cell surface expression in HEK293 cells expressing β2AR. Mutagenesis analysis of β2AR confirmed the SILCS identified allosteric modulator binding site that comprises of F282, Y219, and R131. Finally, functional studies revealed augmentation of β‐agonist‐induced relaxation of contracted human ASM cells and bronchodilation of contracted murine airways by PAM.ConclusionThese findings identify a novel allosteric binding site on the β2AR, whose activation selectively augments β‐agonist‐induced Gs signaling and increases relaxation of ASM cells, the principal therapeutic effect of β‐agonists in obstructive lung disease such as asthma and COPD.
Using Q‐Methodology to Evaluate Student Perceptions of Online Anatomy in the Time of COVID‐19
Authors: Saini Jessica , Brewer‐Deluce Danielle , Akhtar‐Danesh Noori , Saraco Anthony N. , Bayer Ilana , Pitt Courtney , Wainman Bruce 
Published: May 2022

BackgroundSince the seventeenth century, the primary approach to teaching anatomy has involved hands‐on learning using cadaveric specimens. However, the ability to use this long‐standing tradition was curtailed in the 2020‐2021 school year due to the COVID‐19 pandemic. Many institutions closed physical classrooms entirely, launching experiential courses, such as anatomy, into the online space.HypothesisWe hypothesized that Q‐methodology could be used to uncover student perceptions of an introductory anatomy and physiology course that was offered online for the very first time.MethodsQ‐methodology, considered the study of subjectivity, is an approach that statistically uncovers groups of individuals with shared perceptions within a larger cohort. Instructors can use Q‐methodology to identify groups of students with shared needs, allowing for more specific and productive course reform. In the current study, Q‐methodology was used as a means of course evaluation in the fall 2020 and winter 2021 semesters. Students were asked to sort 44 opinion‐based statements in a quasi‐normal table based on their level of agreement. By‐person factor analysis of 166 responses revealed three statistically distinct groups of students.ResultsThe three groups were assigned the following monikers: Connected and Contented (CC), Disconnected and Disgruntled (DD), and Interconnected and Collaborative (IC). CC students (n=66) felt generally ambivalent toward course components and were comfortable with the technology skills required to participate in the online course space. DD students (n=50) were deeply unhappy with several elements of the course, including lectures, assignments, and evaluations. These students also felt as if they were teaching themselves. Finally, IC students (n=29) looked favourably upon the tutorial space and the role of teaching assistants. Analysis also revealed that some sentiments were shared across all three groups, including the preference for physical rather than virtual specimens, and the desire for more practice questions from faculty in order to prepare for bellringer exams. Interestingly, cohort opinions did not remain static across both semesters. There was a positive attitude shift as more students felt “Disconnected and Disgruntled” in the fall, and “Connected and Contented” in the winter.ConclusionsThese findings are useful for anatomy instructors interested in transitioning courses to an online or blended space, particularly in the face of ever evolving public health restrictions. The current study also models the wealth of information that can be uncovered using Q‐methodology ‐ useful for anyone interested in the previously amorphous study of subjectivity.
Obesity exacerbates SARS‐CoV‐2 infection in K18‐hACE2 mice
Authors: Berdasco Clara , Whitehead Anna , Qin Xuebin , Yue Xinping , Lazartigues Eric 
Published: May 2022

Hypertension and obesity are considered risk factors for severe coronavirus disease 2019 (COVID‐19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2). The aim of the current study was to examine whether hypertension and obesity alter SARS‐CoV‐2 infection, the development of the disease and possible underlying mechanisms, using the K18‐hACE2 transgenic mice.Three groups of male K18‐hACE2 mice (5 mice/group, 5‐month‐old) were infected intranasally with SARS‐CoV‐2 (strain USA_WA1/2020, 104 PFU in 100 µl). Prior to infection, one group of mice was fed a hypercaloric diet (HCD, high fat high sucrose diet) for 3 months to model obesity; the second group of mice, on regular diet (RD), was infused with Angiotensin (Ang)‐II (600 ng/kg/min) for 3 weeks to model hypertension; and the third group of mice on RD served as control. Body weight was monitored daily post infection (dpi), and all mice were sacrificed at 7 dpi. RNA was extracted from kidney, heart, and lung, and RT‐qPCR was performed to measure tissue viral load and cytokine expression. Tissue damage was assessed on formalin‐fixed and paraffin‐embedded sections.The three groups of mice suffered similar weight loss following infection (~15% by 7 dpi). Compared to control and hypertensive groups, in which the viral loads were similar across the tissues examined (lung, heart, and kidney), viral load in the heart of obese mice was significantly higher than in the lung and the kidney (Heart: 7.26 ±0.2 vs. Lung: 3.75 ±0.2 vs. Kidney: 2.48 ±0.4, expressed as Log10 of viral copy number per 100 ng RNA, p<0.05, two‐way ANOVA). In addition, compared to control mice, obese mice showed increased expression of CXCL1/KC in both kidney (HCD: 1.98 ±0.3 vs. RD: 0.74 ±0.1, p<0.05) and lung (HCD: 7.05 ±1.1 vs. RD: 2.39 ±0.3, p<0.05), and increased expression of IL‐17 in the lung (HCD: 1.44 ±0.1 vs. RD: 0.92 ±0.1, p<0.05). Furthermore, obese mice showed the highest expression of IL‐6 (HCD: 3.96 ±0.9 vs. Ang‐II: 1.1 ±0.1 vs. RD: 1.56 ±0.4, p<0.05) and TNFα (HCD: 14.08 ±0.6 vs. Ang‐II: 7.14 ±0.8 vs. RD: 6.03 ±1.13 mRNA expression level, p<0.05, one‐way ANOVA) in the lung among the three groups. Finally, the obese mice showed the highest lung infiltration (HCD: 15.6 ±1.4 vs. Ang‐II: 8.1 ±2.2 vs. RD: 6.38 ±1.3 infiltrated area/total area in %, p<0.05, one‐way ANOVA).Our study suggests that obesity significantly increases tissue inflammation following SARS‐CoV‐2 infection, with the heart at particular risk of higher SARS‐CoV‐2 infection; in contrast, acute hypertension induced by Ang‐II infusion does not significantly alter SARS‐CoV‐2 infection or COVID‐19 disease course.
Increased Muscle Sympathetic Nerve Activity with Acute Hyperinsulinemia: Role of Insulin‐stimulated Peripheral Vasodilation and the Response of the Arterial Baroreflex
Authors: McMillan Neil J. , Soares Rogerio N. , Harper Jennifer L. , Shariffi Brian , Moreno‐Cabanas Alfonso , Curry Timothy B. , Manrique‐Acevedo Camila , Padilla Jaume , Limberg Jacqueline K. 
Published: May 2022

ObjectiveHyperinsulinemia elicits an increase sympathetic nervous system activity directed toward skeletal muscle (muscle sympathetic nerve activity, MSNA). The insulin‐mediated increase in MSNA is primarily attributed to its effect within the central nervous system. In addition to direct central effects, insulin also elicits peripheral vasodilation, which may further increase MSNA via arterial baroreflex‐mediated mechanisms in order to maintain blood pressure (BP). Herein we examined the contribution of insulin‐induced peripheral vasodilation and role for the arterial baroreflex in the MSNA response to hyperinsulinemia. We hypothesized that rescuing peripheral resistance with co‐infusion of the vasoconstrictor phenylephrine would attenuate the MSNA response to hyperinsulinemia. We further hypothesized the insulin‐mediated increase in MSNA would be recapitulated with another vasodilator (sodium nitroprusside, SNP).MethodsIn 33 healthy adults (28M/5F, 28±1 yrs, BMI 25.0±0.5 kg/m2) MSNA (microneurography) and BP (Finometer/brachial catheter) were measured, and total peripheral resistance (TPR, ModelFlow) was calculated at rest and during intravenous insulin (n=20) or SNP (n=13) infusion. A subset of participants receiving insulin (n=7) were co‐infused with phenylephrine. Spontaneous arterial baroreflex sensitivity was determined over 5‐min at baseline and during pharmacological intervention(s).ResultsInsulin infusion increased MSNA (p=0.05) and decreased TPR (p<0.05), with no effects on arterial baroreflex sensitivity or BP (p>0.05). Co‐infusion with phenylephrine returned MSNA and TPR to baseline, with no effect on baroreflex sensitivity (p>0.05). Similar to insulin, SNP increased MSNA (p<0.01) and decreased TPR (p<0.05), with no effect on baroreflex sensitivity (p>0.05).ConclusionsPresent findings reveal that acute hyperinsulinemia increases MSNA without a change in arterial baroreflex sensitivity in healthy men and women. Insulin‐mediated increases in MSNA are lost with co‐infusion of phenylephrine and can be recapitulated with infusion of SNP. Results support a dynamic interplay between central and peripheral mechanisms during hyperinsulinemia to increase MSNA and maintain BP.
Cardiovascular and autonomic profiles in offspring of fructose fed parents: role of anti‐inflammatory cholinergic reflex and exercise training
Authors: da Silva Dias Danielle , dos Santos Camila P. , Araújo Amanda A. , Ferreira Maycon J. , Nascimento‐Filho Antonio V. , Bernardes Nathalia , Irigoyen Maria Cláudia , De Angelis Kátia 
Published: May 2022

AimConsidering that anti‐inflammatory cholinergic reflex has been implicated in cardiovascular disorder, and spleen seems to be a critical organ in this reflex, here we evaluated the impact of aerobic exercise training on cardiovascular and autonomic profiles in offspring of rats submitted to fructose overload, as well as, the role of the splenectomy in this condition.MethodsOffspring of Wistar rats treated with fructose or placebo (water) were divided into 5 groups: Sedentary Control (OC), Sedentary Fructose (OF), Trained Fructose (OFT), Splenectomized Sedentary Fructose (OFE) and Splenectomized Trained Fructose (OFST). Fructose overload (10%) was started 30 days after weaning only for the parents and continued until the end of lactation. The offspring received standard feeding and were evaluated 30 days after weaning, at which time the spleen was removed (splenectomy) and the aerobic exercise training was realized on treadmill (1h/d, 5d/week, 4 weeks, moderate intensity). Blood pressure (BP) and heart rate (HR) signals were direct recorded, baroreflex sensitivity (BRS) was measured using increasing doses of phenylephrine and sodium nitroprusside. Oxidative stress was measured in cardiac tissue.ResultsSystolic BP, Diastolic BP and Mean BP increase in OF compared to OC, OFT, OFE and OFST groups (OC: 105±1.3, OF: 112±1.6, OFT: 104±2.4, OFE: 103±3.1, OFST: 104±2 mmHg) HR reduced in the OFT compared to the OC group. Regarding BRS, bradycardic and tachycardic responses were impaired in OF compared to OC group; and OFE, OFT and OFST groups increased these parameters compared to OF group. In the antioxidant profile in cardiac tissue, the activities of catalase and superoxide dismutase were reduced in the OF group compared to the OC group, and increased in the OFE, OFT and OFST groups compared to the OF group. Protein oxidation was increased in the OF group compared to the OC, OFE, OFT and OFST groups (OC: 5.37±0.15, OF: 6.41±0.21, OFT: 4.93±0.3, OFE: 4.94±0.23, OFST: 4.66±0.46 nmol/mg protein). The redox balance of glutathione (GSH/GSSG) was decreased in the OF group compared to the OC and OFT groups.ConclusionThese results demonstrate that fructose exposure in parents induced early changes in offspring BP, BRS and cardiac oxidative stress, that seems to be mediated, at least in part, by the anti‐inflammatory cholinergic reflex. Moreover exercise training seems to prevent/attenuate such dysfunctions.
Tumor‐Suppressor Role of the Caveolar α1‐Na/K‐ATPase Signalosome in NASH related Hepatocellular Carcinoma
Authors: Udoh Utibe‐Abasi S. , Banerjee Moumita , Rajan Pradeep K. , Sanabria Juan D. , Smith Gary , Nakafuku Yuto , Sodhi Komal , Pierre Sandrine V. , Xie Zijian , Shapiro Joseph I. , Sanabria Juan R. 
Published: May 2022

BackgroundHepatocellular Carcinoma (HCC) is the second and fastest‐growing cause of cancer‐ related mortality worldwide. In the Western countries, due to the epidemic of obesity, non‐alcoholic steatohepatitis (NASH) has become the major cause of HCC. Intriguingly, the molecular mechanisms that underlie the progression of NASH to HCC is still unclear.HypothesisWe hypothesized that, the growing uncoupled metabolism during NASH progression to ESLD and HCC manifested by lower cell oxi‐redox status and an apoptotic ‘switch’ activity, follows a dysregulation in the wild type Caveolar α1‐Na/K‐ATPase (NKA)/Src signalosome, promoting an amplification of the pSrc → PI3K→ Akt pathway, which mediates survivin overexpression driving local carcinogenesis.MethodsExpression of Cav‐1/Smac‐Diablo/Survivin proteins was performed by confocal‐microscopy on immuno‐stained HCC cell lines (Hep3B and SNU475), and livers in both NASH and NASH‐HCC rodent models, and in humans. Apoptotic activity was assayed via TUNEL. Tumor burden in rodents’ livers were evaluated using ImageJ software on H&E‐stained liver tissues and fibrosis via trichrome staining. Furthermore, signaling pathway studies were explored in‐vitro guided by RNA sequencing. Selective blockage of Src‐p at its kinase domain was performed by administration of a synthetic peptide (pNaKtide). Significant differences among groups were established at p<0.05 using ANOVA/Turkey’s post hoc test.ResultsBlockage of Src‐p at the α1‐NKA promoted apoptosis of Human HCC cell lines and tumors of disease murine models in a dose dependent manner (p< 0.01). pNaKtide at IC50 drove the downregulation and upregulation of Survivin and SMAC expressions (p<0.05), respectively in HCC cell lines. In‐vivo, liver tumor burden and fibrosis were significantly lower in animals treated with pNaKtide vs non‐treated animals (p<0.01). Furthermore, Cav‐1 and Survivin expressions were significantly higher, while SMAC protein expression was significantly lower in livers from rodents with NASH/HCC vs animals treated with pNaKtide (p<0.01). Similar pattern of proteins expressions was noted in tumors from patients with NASH±HCC vs liver tissue from healthy subjects or subjects with liver metastases (p<0.05). In‐vitro, Src‐p at the α1‐NKA activates PI3K/Akt pathway with concomitant inhibition of the FoxO cascade, favoring cell division and primary liver carcinogenesis.ConclusionsCaveolar Src‐phosphorylation at the α1‐Na/K‐ATPase regulated Survivin/SMAC expressions, leading to cellular “switch” from apoptosis to cell division via the activation of the PI3K/Akt pro‐survival pathway with concomitant inhibition of the FoxO cascade. Therefore, point target blockage may be explored as a treatment for tumor regression in HCC.
Fenofibrate induced‐hepatomegaly and liver regeneration is PPARα dependent and partially related to the activation of YAP pathway
Authors: Fan Shicheng , Gao Yue , Qu Aijuan , Jiang Yiming , Xie Guomin , Yao Xinpeng , Yang Xiao , Yagai Tomoki , Tian Jianing , Wang Ruimin , Gonzalez Frank J. , Huang Min , Bi Huichang 
Published: May 2022

Background and ObjectiveFenofibrate, an agonist of peroxisome proliferator activated receptor α (PPARα), has been widely used as a lipid‐regulating agent in clinical practice. Recent studies found that fenofibrate can significantly induce hepatomegaly in mice, but the involved mechanisms remain unclear.MethodsThe effect of fenofibrate on hepatomegaly and liver regeneration was investigated in several strains of genetically‐modified mice including Pparafl/fland PparaΔHep mice. Staining assays were performed to investigate the effect of fenofibrate on hepatocyte size and proliferation during hepatomegaly and liver regeneration. AAV‐Yap shRNA mice model was further used to determine the role of YAP in PPARα‐induced hepatomegaly. Western blot analysis was used to detect the protein expressions of YAP signaling pathway as well as other factors potentially involved in fenofibrate‐induced hepatomegaly.ResultsThe study demonstrated that fenofibrate significantly induced liver enlargement in wild‐type and Pparafl/fl mice, while this effect was abolished in hepatocyte‐specific Ppara‐deficient (PparaΔHep) mice. Furthermore, fenofibrate significantly promoted liver regeneration in wild‐type mice following 70% partial hepatectomy (PHx). Staining assays revealed that fenofibrate promoted hepatocyte enlargement around the central vein area and hepatocyte proliferation around the portal vein area in wild‐type, Pparafl/fl and PHx mice. Fenofibrate regulated protein expressions of YAP and its downstream targets (CTGF, CRY61 and ANKRD1) as well as proliferation‐related proteins (CCNA1, CCND1 and CCNE1). Suppression of YAP using AAV‐Yap shRNA repressed fenofibrate‐induced hepatomegaly, as well as hepatocyte enlargement and proliferation. Other factors might also participate in fenofibrate‐induced hepatomegaly, including MYC, KRT23, RHOA and RAS.ConclusionThese studies revealed a novel role of fenofibrate in promoting liver enlargement and regeneration, which is PPARα dependent and partially related to the activation of YAP signaling pathway. These findings provide clinical relevance of fenofibrate as a potential medication for promoting liver regeneration.