bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nitric Oxide‐dependent Cutaneous Vasodilation is not Altered in Adults Following SARS‐CoV‐2 Infection
Authors: Dillon Gabrielle A. , Swanger Faith A. , Wolf S. T. , Alexander Lacy M. 
Published: May 2022

Cardiovascular complications are part of the clinical sequelae following SARS‐CoV‐2 infection. Vascular dysfunction, one of the earliest indicators of cardiovascular disease (CVD), has been reported in adults who have recovered from COVID‐19. To date, no studies have investigated the underlying mechanisms of persistent COVID‐19‐associated vascular dysfunction. Additionally, physical activity (PA) status has not been accounted for when examining vascular function in COVID‐19 recovered (CR) adults.PURPOSETo directly quantify nitric oxide (NO)‐dependent vasodilation in the microcirculation in adults who have recovered from SARS‐CoV‐2 infection. Using the skin as a model circulation, we hypothesized that CR adults would have impaired NO‐mediated vasodilation compared to appropriate controls, and PA would be positively associated with NO‐dependent vasodilation in CR.METHODSWe performed a cross‐sectional study including: 10 (5M/5W, 24 ± 4yrs) healthy control (HC) adults who were unvaccinated for COVID‐19, 11 (4M/7W, 25 ± 6yrs) healthy vaccinated (HV) adults, and 12 (5M/7W, 22 ± 3yrs) CR (19 ± 14 weeks post‐diagnosis) adults. COVID‐19 symptoms severity (survey) and PA (accelerometer) for 7 days prior to the experimental visit were assessed. A standardized 39°C local heating protocol was used to induce eNOS‐dependent vasodilation, quantified via perfusion (intradermal microdialysis) of 15 mM NG‐nitro‐l‐arginine methyl ester during the plateau of the heating response. Red blood cell flux was measured (laser‐Doppler flowmetry) and cutaneous vascular conductance (CVC = flux/mmHg) was expressed as a percentage of maximum (28mM sodium nitroprusside + 43°C). All data are means ± standard error.RESULTSThe local heating plateau (HC: 61 ± 20 %CVCmax, HV: 60 ± 19 %CVCmax, CR: 67 ± 19 %CVCmax, p=0.80) and NO‐dependent vasodilation (HC: 77 ± 9%, HV: 71 ± 7%, CR: 70 ± 10%, p=0.36) were not different among groups. In the CR group neither peak symptom severity (25 ± 12 AU) nor time since diagnosis correlated with NO‐dependent vasodilation (R2=0.21, p=0.13 and R2=0.17, p=0.19, respectively). PA was not different among groups (see Table). PA did not correlate with the NO‐dependent vasodilation in CR (sedentary: R2<0.01, p=0.89; light: R2=0.04, p=0.63; moderate‐to‐very vigorous: R2=0.35, p=0.16).CONCLUSIONOtherwise healthy young adults who have had COVID‐19 did not have impaired NO‐dependent cutaneous vasodilation. Additionally, in this cohort of CR adults, symptomology and physical activity was not related to microvascular function. As such, investigations in adults who have had more severe COVID‐19 cases are necessary. Discovering the underlying mechanisms linking SARS‐CoV‐2 infection and cardiovascular consequences are important for identifying additional treatment strategies for long haul COVID‐19.
An Evaluation of the Stability of Splicing Protein Dib1 Through Circular Dichroism Spectroscopy
Authors: Dunn Richard , Conde Anabelle , Lee Grace , Meeks Garrison , Pittner Nick , Maeder Corina 
Published: May 2022

Pre‐messenger RNA (pre‐mRNA) splicing is the process in which introns, noncoding regions of DNA, are removed and exons, coding regions of DNA, are ligated to produce a mature mRNA transcript. This process is mediated by the spliceosome, a dynamic macromolecular complex composed of five small nuclear ribonucleoproteins and other protein factors. At the catalytic center of the splicing machinery is the evolutionarily conserved yeast protein, Dib1, composed of 143 amino acids essential for splicing and cell viability. Dib1 and its human ortholog, hDim1, have demonstrated peptidase activity, specifically autocleavage of the last thirteen and fourteen amino acids, respectively, of their carboxy‐terminal tails. The mechanism and function of this autocleavage activity of the carboxy‐terminal tail is uncharacterized.Previous yeast growth assays comparing mutants to wildtype Dib1 have established that deletion of fifteen and sixteen amino acids off the carboxy‐terminal tail results in temperature‐sensitivity of yeast cell growth at 37ºC. Since Dib1 and splicing are essential for cell viability, the temperature‐sensitive mutants suggest that truncations to the carboxy‐terminal tail of Dib1 may result in defective splicing. Thus, the carboxy‐terminal tail may play a direct role in splicing or destabilize splicing complexes. To address these two possible hypotheses, we are investigating the effects of the carboxy‐terminal truncations on Dib1 stability. Protein purification of wild type and a series of truncated Dib1 mutants were performed. Circular dichroism spectroscopy employing increasing concentrations of guanidinium hydrochloride, a protein denaturant, was used to determine the stability of Dib1 and its truncated mutants. Overall, our findings show that Dib1 stability is directly linked to the length of the tail region and lead us to speculate that the tail is critical for stabilization of the spliceosomal complex.
Developing a Mouse Model to Test the Impact of Metabolic Syndrome on Systemic Lupus Erythematosus‐Induced Organ Damage
Authors: Kakalij Rahul M. , Boesen Erika I. 
Published: May 2022

Background/hypothesis of the studyMetabolic syndrome (MetS) is characterized by a group of conditions that include obesity, impaired glucose tolerance, dyslipidemia and hypertension. MetS is common in systemic erythematosus (SLE) patients and associated with increased cardio‐renal risk. The present study was carried out to develop a model to use in future investigations of whether MetS accelerates SLE‐induced organ damage.Methods and ResultsFemale C57BL/6 mice were untreated or treated epicutaneously with the TLR7 agonist imiquimod (IMQ) and fed a high‐fat (HF) “Western” diet (fat 42% kcal, sucrose 34% kcal) or control diet (fat 12.6% kcal, sucrose 34% kcal) for 6 weeks. Data at 6 weeks were compared by two‐way ANOVA, with n=8 mice per group. Supporting early‐stage induction of autoimmunity, spleen weights were significantly increased in IMQ‐treated mice (PTreatment<0.001), and renal cortex IgG deposition was confirmed by western blot. Increased body weight, gonadal fat pad mass, and plasma leptin levels were observed between HF and control animals (PDiet<0.001) for both IMQ and untreated mice. At the 6th week, HF animals showed an inrease in 24‐hour calorie intake (PDiet<0.05) in contrast to control animals. At the same time, HF diet increased total cholesterol (PDiet<0.05) when compared with control diet‐fed animals. However, the increase in these parameters with HF diet was significantly diminished in IMQ‐treated mice (PDiet*Treatment<0.05). Both the HF diet (PDiet<0.001) and IMQ treatment (PTreatment<0.05) significantly increased fasting blood glucose. IMQ treatment affected fasting insulin concentrations in a diet‐dependent manner (PDiet*Treatment<0.01), with hyperinsulinemia observed in IMQ‐HF treated mice (178±8 μIU/ml) compared to IMQ‐treated control diet mice (49±8 μIU/ml; P<0.05 by Bonferroni post‐hoc test), with plasma insulin similar between untreated mice on HF (112±19 μIU/ml) and control diets (98±20 μIU/ml; P>0.05).ConclusionTogether, these data indicate that the IMQ model of SLE is associated with metabolic alterations, impaired glycemic control, hypercholesterolemia, and hyperinsulinemia under HF intake conditions. In the future, this model may be helpful to understand the complex relationship between MetS and organ damage in SLE.
A New Family of Subnanomolar inhibitors of Soluble Epoxide Hydrolase
Authors: Escolano Carmen , Bagan Andrea , Turcu Andreea L. , Morisseau Christophe , Loza M. I. , Brea Jose , Bartra Clara , Sanfeliu Coral , Hammock Bruce D. , Vázquez Santiago 
Published: May 2022

The pharmacological inhibition of soluble epoxide hydrolase (sEH) has been suggested as a potential therapy for the treatment of pain and inflammatory diseases through the stabilization of epoxyeicosatrienoic acids, endogenous chemical mediators derived from arachidonic acid that show anti‐inflammatory and analgesic effects.1Although several potent sEH inhibitors (sEHI) have been developed, including clinical candidates AR9281, GSK2256294, and EC5026, so far no sEHI has reached the market.2Recently, a new series of benzohomoadamantane‐based ureas endowed with potent inhibitory activity for the human and murine sEH was reported. However, their very low microsomal stability prevented further development.3Herein, novel series of benzohomoadamantane‐based ureas were synthesized, fully characterized, and evaluated as sEHI. Most of them were endowed with subnanomolar inhibitory potencies at the human and murine enzymes. Further in vitro profiling (solubility, cytotoxicity, metabolic stability, CYP450s, hLOX‐5, hCOX‐2, hERG inhibition, permeability) allowed us to select a candidate for efficacy studies.In summary, these novel results and the previously reported studies using other families of sEHI, strongly suggest that sEH may be a target of clinical interest for the treatment of inflammatory and pain‐related disorders.4References:

1‐Morisseau, C.; Hammock, B. D. Annu.Rev. Pharmacol. Toxicol. 2013, 53, 37–58.
2‐Sun, C.‐P.; Zhang, X.‐Y.; Morisseau, C.; Hwang, S. H.; Zhang, Z.‐J.; Hammock, B. D.; Ma, X.‐C. J. Med. Chem. 2021, 64, 184–215.
3‐Codony, S.; Calvó‐Tusell, C.; Valverde, E.; Osuna, S.; Morisseau, C.; Loza, M. I.; Brea, J.; Pérez, C.; Rodríguez‐Franco, M. I.; Pizarro‐Delgado, J.; Corpas, R.; Griñán‐Ferré, C.; Pallàs, M.; Sanfeliu, C.; Vázquez‐Carrera, M.; Hammock, B. D.; Feixas, F.; Vázquez, S. J. Med. Chem., 2021, 64, 5429–5446.
4‐McReynolds, C.; Morisseau, C.; Wagner, K.; Hammock, B. D. Adv. Exp. Med. Biol. 2020, 1274, 71–99.
Protective effects of Empagliflozin against Transforming growth factor‐beta‐induced fibrosis in renal proximal tubular cells
Authors: Bayne Sarah , Munusamy Shankar 
Published: May 2022

BackgroundChronic kidney disease (CKD) is the condition where the kidneys are unable to filter and clean the blood of waste properly. Hypertension, obesity, and diabetes are the leading risk factors for developing CKD. Fibrosis is regarded as a final common pathway leading to CKD. Sodium‐glucose co‐transporter 2 (SGLT‐2) inhibitors have shown to be renoprotective in type 2 diabetes patients. However, the mechanisms that underlie the renoprotective effects of SGLT‐2 inhibitors are unclear. Our study investigated whether empagliflozin (an SGLT‐2 inhibitor) treatment inhibits transforming growth factor β (TGF‐β)‐mediated fibrosis and profibrotic signaling in rat renal proximal tubular cells (NRK‐52E).MethodsNRK‐52E cells were cultured and treated with TGF‐β with or without empagliflozin for 24 and 48 hours. The expression of fibrosis markers ‐ alpha‐smooth muscle actin (α‐SMA) and vimentin, autophagy marker – LC3II, and TGF‐b‐mediated profibrotic signaling marker ‐ SMAD 2 – were measured by western blotting.ResultsTGF‐β treatment (at 5 ng/mL and 10 ng/mL) for 24 and 48 hours induced fibrosis and activated autophagy signaling in renal proximal tubular cells. For instance, 48 h TGF‐β treatment at 10 ng/mL induced the expression of α‐SMA by 1.43‐fold and LC3II by 2.6‐fold as compared to vehicle‐treated cells. Co‐treatment with empagliflozin (100 and 500 nM) reduced the expression of the fibrotic markers (α‐SMA, vimentin), autophagy marker (LC3II) and TGF‐β‐mediated phosphorylation of SMAD‐2 in renal proximal tubular cells.ConclusionsOur preliminary findings indicate that TGF‐β‐mediated induction of fibrosis, autophagy, and profibrotic signaling could be attenuated by empagliflozin treatment. Further studies are required to understand the molecular mechanisms that underpin the antifibrotic effects of empagliflozin against TGF‐β‐induced renal fibrosis.
Global Toll‐like Receptor 4 Knockout Prevents Cerebrovascular Dysfunction Associated with Chronic Stress
Authors: Burrage Emily N. , Prabhu Saina , Frazier James , Englund Phillip , Mills James , Casto Makenzie , Bryner Randy W. , Kelley Eric E. , Chantler Paul D. 
Published: May 2022

Chronic stress is a risk factor for many cerebrovascular diseases including stroke and vascular dementia and our lab has previously shown that chronic stress impairs cerebrovascular function and induces a pro‐inflammatory environment. It is possible that this pro‐inflammatory environment is driven by the activation of toll‐like receptor 4 (TLR4), a potent mediator of inflammation. However, the potential role of TLR4 in chronic stress induced cerebrovascular dysfunction has yet to be examined.Here, we utilized a global TLR4 knock out (TLR4‐/‐) combined with our unpredicted chronic mild stress paradigm (UCMS) to assess middle cerebral artery (MCA) function. At 18 weeks‐of‐age, mice underwent the UCMS paradigm (5 days/weeks for 7hrs/day) to elicit a chronic stress phenotype. On week 26, mice were euthanized and the MCAs were removed and positioned in a pressurized myobath. To test for vessel health, the MCA was exposed to increasing concentrations of acetylcholine (ACh; 10‐9M to 10‐4M), phenylephrine (PE; 10‐9M to 10‐4M), and sodium nitroprusside (SNP; 10‐9M to 10‐4M).TLR4‐/‐ mice displayed a similar MCA response to ACh compared to controls (18.4±0.7mm to 19.4±0.5mm, respectively). Mice exposed to UCMS displayed impaired MCA response to ACh while TLR4‐/‐ mice exposed to UCMS did not display MCA impairment in response to ACh (8.1±0.4mm vs 18.1±0.4mm, respectively; p<0.05). No differences in response to SNP were noted between groups however both TLR4‐/‐and TLR4‐/‐ UCMS mice displayed an impaired response to PE compared to controls (‐16.6±2.3mm and ‐17.6±1.6mm and ‐24.2±2mm, respectively; p<0.05).These data suggest that TLR4 may play a role in the cerebrovascular dysfunction associated with chronic stress.
Human platelet‐mediated transfer of cardioprotection by remote ischemic conditioning is abrogated by aspirin, but not by ticagrelor
Authors: Lieder Helmut R. , Tsounami Maria , Schrör Karsten , Andreadou Ioanna , Heusch Gerd , Kleinbongard Petra 
Published: May 2022

BackgroundRepeated ischemia/reperfusion in a tissue/organ remote from the heart (remote ischemic conditioning, RIC) protects against injury from sustained myocardial ischemia/reperfusion (I/R). Platelets are considered as mediators/targets of RIC´s protection. We have recently reported that infusion of washed platelets, taken from healthy volunteers after RIC, reduced infarct size (IS) in isolated rat hearts (FASEB Journal 2021; 35; S1; DOI: 10.1096/fasebj.2021.35.S1.03444). Anti‐platelet drugs are potential confounders of RIC.AimTo study the impact of anti‐platelet drugs, the cyclooxygenase inhibitor aspirin and the P2Y12 inhibitor ticagrelor, on the platelet‐mediated transfer of cardioprotection.MethodsWe included 18 healthy volunteers. As a contemporary control, volunteers were subjected to RIC through 3 x 5 min blood pressure cuff inflation at 200 mmHg on the left upper arm/ 5 min deflation. After at least 2 weeks, these volunteers were again subjected to RIC 3 hours after pretreatment with oral aspirin (500‐1000 mg) and again at least another 2 weeks later 2 hours after pretreatment with oral ticagrelor (180 mg). Venous blood samples were taken before RIC and 60 min after RIC, respectively. Washed platelets were prepared using apyrase, prostaglandin E1 and citrated Tyrode‐buffer. The platelet count was adjusted to 2.5 x 105platelets/µL. The functionality of washed platelets was tested in response to thrombin (1U/ml), aggregation measured with turbodimetric light transmission aggregometry and expressed as the increase in light transmission in percent of control. Platelet preparations with an aggregation <60% were discarded. Male Lewis rats were sacrificed, their hearts isolated and perfused at constant pressure with buffer. Washed platelets before and after RIC, respectively, were infused for 8 min (2.5 x 104 platelets/µL) into rat hearts before global 30 min/ 120 min I/R. IS was demarcated by triphenyl tetrazolium chloride staining and calculated in percent of ventricular mass.ResultsWe confirm, that infusion of platelets after RIC reduces IS in isolated hearts with global I/R (Figure). This platelet‐mediated transfer of cardioprotection was abrogated by aspirin‐pretreatment of the volunteers (Figure). Platelets before RIC from ticagrelor‐pretreated volunteers reduced IS per se; nevertheless, platelets after RIC further reduced IS (Figure).ConclusionHuman platelets serve as carriers for RIC’s cardioprotective signal through an aspirin‐sensitive and thus cyclooxygenase‐dependent mechanism. The P2Y12 inhibitor ticagrelor per se induces a cardioprotective platelet‐dependent signal, which is further enhanced by RIC. The precise signal transfer from the platelets to the myocardium and the nature of the platelet‐derived factors remain to be further identified.
Inflammatory Activation and Nitric Oxide Oxidation in Exertional Dyspnea in Southwest Asia Deployed Military Veterans
Authors: Pappas Gregory , Vujic Ena , Gardner Carol , Guo Changjiang , Black Kathleen , Therkorn Jennifer , Laskin Debra , Kipen Howard , Falvo Michael , Gow Andrew 
Published: May 2022

Post deployment personnel of the Southwest Asia theater of war present with significant exertional dyspnea. While deployed, these service men and women were exposed to a variety of inhaled toxicants including geological dust, burn pit smoke, and heavy metals. Upon examination, a large portion of these veterans display near‐normal pulmonary function and gas exchange in the lung, making diagnosis and treatment difficult. The aim of this study is to define the physiological and biochemical profiles of individuals with unexplained exertional dyspnea. We hypothesized that exposure to airborne toxicants has led to a chronic activated inflammatory state in the systemic vasculature, resulting in increased oxidative stress and reducing the bioavailability of nitric oxide (NO), contributing to the symptoms of dyspnea.Eligible veterans were tested for lung function by spirometry including diffusing capacity for carbon monoxide (DLco). Resting blood samples were taken and immediately separated into plasma and cellular components. Granuloyctes were removed from whole blood by magnetic separation, and subsequent leukocytes were collected and gated on expression of the myeloid marker CD45. Within CD45+ cells, flow cytometry was used to analyze the expression of inflammatory macrophage activation markers CD87, CD11b, CD163, HLA‐DR, CD195, CD192, CD14, CD16. Circulating levels of nitrite and nitrate (oxidation products of NO) were measured in plasma via reductive chemiluminescence, and the ratio of nitrate/nitrite (NOx ratio) was used as a marker for reduced bioavailability of NO. Increased expression of inflammatory marker CD87 in CD11b+ cells was positively correlated with expression of CD163 in HLA‐DR+ and CD14 in CD16+ (rho = .54, p <.01; rho= .36, p= .047; n =30), but not CD195 in CD192+ (rho =‐.3, p =.1). Similar observations were observed in granulocytic cells regarding CD66b expression. This correlation between activation markers within the circulating myeloid‐derived cells is consistent with the presence of monocyte activation in the systemic vasculature. NOx levels were within normally observable bounds, however, the NOx ratio was negatively correlated with FEV1/FVC (a marker of lung obstruction) but not with %predicted DLco(rho =‐.56, p =.016; rho =.01, p = .96, n = 18). The reduction in FEV1/FVC with increased NOx ratio suggests potential loss of endothelial function, which may be contributing to exertional dyspnea and is currently under investigation.
Massage application to increase the spread of local anesthesia in sciatic nerve blocks: A cadaveric study
Authors: Robertson Taylor C. , Fisher Cara C. , Handler Emma C. , Nash Daniel 
Published: May 2022

IntroductionSciatic nerve blocks are essential for surgical treatment of various lower limb pathologies. Due to the complexity and variation of anatomical landmarks, ultrasound (US) guided injection of local anesthesia has become common practice. In patients with thicker thigh girth (i.e., obese patients) excess tissue may distort US penetration thereby diminishing efficacy of the nerve block and/or cause severe post‐operative pain. Dye tracing techniques have been used to test the effectiveness of nerve blocks, but there is little research on using massage to manipulate anesthetic spread. Therefore, the aim of this study is to assess the effects of massage to manipulate local anesthesia spread in sciatic nerve blocks. We hypothesize massaging after injection will increase the spread of local anesthesia compared to non‐massage post injection.MethodsForty un‐fixed cadaveric legs were injected with a mixture of methylene blue dye and 2% Lidocaine Hydrochloride. Specimens were divided into non‐massage (control) (n=20) and massage (n=20) groups. Sciatic nerve blocks were performed by a nurse anesthetist using US guidance at the popliteal fossa traveling proximally until the sciatic nerve was identified and the location was tagged. Immediately following, massage group specimens received five repeated proximally directed massages with the US transducer head. Specimens from both groups were then dissected to expose the sciatic nerve. Measurements of the distance traveled from marked site of injection to proximal end of dyed area were measured and compared.ResultsSpread of local anesthesia in the inferior‐superior direction was significantly higher in the massage group than the control group (p≤0.05).ConclusionsMassaging post‐injection caused a greater spread of local anesthesia during sciatic nerve block.SignificanceSciatic nerve block techniques often utilize nerve stimulation to identify the sciatic nerve location. This may be due to lack of US penetration through the gluteus maximus muscle. In patients with thicker thigh girth due to subcutaneous fat, imaging visibility may be more difficult as well. Our findings suggest that clinicians may block the sciatic nerve at a more distal location with US guidance and manipulate the anesthesia to the region of interest.
Blocking the entry of HIV into host cells through co‐receptor inhibition
Authors: Ralli Garyfallia , Pedzisa Lee 
Published: May 2022

The goal of our project is to synthesize a dual CXCR4/CCR5 co‐receptor inhibitor to block the entry of HIV into host cells.In the early phase of the HIV‐1 replication cycle, HIV‐1 binds to host cells through the CD4 protein present on the host cell surface. To infect the cell, HIV‐1 requires further interactions that promote fusion of the viral and cellular membranes. This can occur through binding to the chemokine co‐receptors such as CXCR4 and CCR5. We are choosing dual inhibition since under selective pressure of a CCR5 antagonist, CXCR4‐using strains have been shown to predominate. Through dual inhibition, we want to account for a possible resistance development that could occur when inhibiting only one of the two co‐receptors.Using a computational screen, a compound predicted to bind to both CCR5 and CXCR4 was identified (Hit 1). We established a reaction scheme to synthesize an analog of this compound (target compound 4) through solid phase peptide synthesis (Scheme 1). We completed the synthesis of compound 4 and we confirmed the addition of the first two amino acids (Fmoc‐phenylalanine and Fmoc‐proline) through LC‐MS and HPLC.We are currently expecting LC‐MS and HPLC results for the rest of the synthesis steps. Before the time of presentation, we plan to use our established methodology to synthesize multiple analogs through varying amino acids and evaluate them for biological activity. The goal of synthesizing analogs is to optimize CXCR4/CCR5 dual inhibition.