bluuebunny/crossref_metadata_2025 huggingface dataset:
A “Histodilutional Barrier” Formed in Gastric Mucosa by VEGF Pretreatment Protects Ethanol‐Induced Hemorrhagic Gastric Erosions in Rats
Authors: Deng Xiaoming , Xiong Ximing , Szabo Sandor
Published: June 2021

Since VEGF increases vascular permeability (VP), we tested the hypothesis that it might create a perivascular “histodilutional barrier”, like histamine, hence delay the absorption of damaging chemicals.

Methods

Fasted Sprague‐Dawley rats were given VEGF164 (0.01, 0.04, or 0.2 ug/100g) by gavage either alone or 30 min before administration of 75% ethanol (1 ml/kg). Evans blue was injected i.v. 15 min before autopsy. Rats were euthanized 30 min after VEGF alone or 1 hr after ethanol administration. Scrapings of gastric mucosa were harvested for VP measurement spectrophotometrically (560 nm) of Evans blueextravasation in the gastric mucosa. Hemorrhagic gastric mucosal lesions were measured by an Imaging Analysis System and calculated as % of glandular stomach, and also examined by histology.

Results

0.04ug/100g VEGF treatment significantly increased gastric VP compared to the controls (p < 0.05). Pretreatment with 0.01, 0.04, or 0.2 ug/100g VEGF reduced ethanol‐induced lesions from 10.6±1.7% (controls) to 8.9±1.8, 0.9±0.2 (p <0.01), or 2.8±0.7% (p <0.05), respectively. Histologic examination showed mild or moderate gastric edema in lamina propria or submucosa after VEGF alone, and no or only superficial gastric erosions in the rats treated with VEGF + ethanol.

Conclusions

1) Pretreatment with VEGF offered dose‐dependent gastroprotection in rats exposed to ethanol. 2) The likely mechanisms might be related to a histodilutional barrier induced by VEGF. 3) Further studies are needed to elucidate the molecular mechanisms of this new form of gastroprotection.

(Supported by VA Merit Review Grants to S. Szabo).
Transglutaminase 2 as a Possible Chemotherapeutic Target in Glioblastoma Multiforme
Authors: Monteagudo Alina , Gundemir Soner , Keillor Jeffrey , Johnson Gail
Published: June 2021

Glioblastoma multiforme (GBM) is the most common primary brain tumor in adults. Despite advances in therapies, patients with GBM still have a 14 month median survival rate after treatment. A common feature of GBM tumors is the presence of hypoxic microenvironments due to insufficient perfusion; which ranges from 4 to <1% oxygen. It has been reported that cells in these hypoxic regions show increased resistance to current therapies used to treat GBM patients. Therefore, it is important to define molecular mechanisms that help the cells survive in hypoxia. One possible therapeutic target is the multifunctional protein transglutaminase 2 (TG2), which plays a role in promoting cell proliferation and survival in various tissues. Interestingly, increased expression of TG2 in GBM tumors correlates with shorter survival times. The goal of this project is to determine if TG2 affects GBM proliferation and survival, in both normoxia and hypoxia, and whether we can use NC9, a novel TG2 inhibitor, as a chemotherapeutic agent in GBM cells. We found that NC9 effectively inhibits colony formation of GBM cells in a TG2‐dependent manner. Results from an EdU incorporation assay show that NC9 decreases the proliferation rate of GBM cells in both normoxic and hypoxic conditions. Markers for the NF‐κB proliferation pathway showed a marked reduction as a result of NC9 treatment. NC9 was not toxic to primary cortical neurons or astrocytes at the concentrations used, which is encouraging for clinical potential. Our results suggest that TG2 is involved in GBM proliferation and NC9, or its derivatives, have the potential to be clinically used for the treatment of GBM.
N‐cadherin Upregulation and EMT Progression in As3+ and Cd2+‐Transformed Urothelial Cells
Authors: Sandquist Elizabeth , Somji Seema , Sens Donald , Garrett Scott
Published: June 2021

Environmental agents are common causes of bladder cancer. Specifically, As3+ and Cd2+ are carcinogens implicated in bladder cancer development. Studies from our laboratory show that As3+ and Cd2+ cause malignant transformation of immortalized bladder urothelial cells, which form tumors in nude mice. Microarray analysis of repeated metal transformation in parallel revealed that N‐cadherin was the most upregulated gene in As3+ transformants, and a top induced gene in Cd2+ transformed cells. The E‐ to N‐cadherin switch is a well‐known indicator of the epithelial‐to‐mesenchymal transition (EMT) in cancer. N‐cadherin is correlated with tumor stage, increased recurrence, and decreased survival. While factors mediating E‐cadherin are well established, little is known of the regulation of N‐cadherin. The goal of the present study was to determine if N‐cadherin upregulation is maintained in animal models, the mechanism by which metal transformation leads to sustained N‐cadherin expression, and if this elevation is involved in EMT. Both mRNA and protein levels of N‐cadherin were increased in As3+ and Cd2+ transformed cell isolates, with focal expression present in intraperitoneal tumor heterotransplants. Twist and Snail were also elevated, indicating EMT. N‐cadherin may be epigenetically regulated, as MS‐275 and 5‐azacytidine altered N‐cadherin levels. Exposure of nontransformed urothelial cells to As3+ induced N‐cadherin, suggesting that heavy metal exposure promotes bladder cancer progression and EMT.

Grant Funding Source: ND INBRE: 8P20GM103442‐14 from NIGMS and R25 ES016250 from NIEHS
Caloric Restriction Confers Anti‐Oxidative, Pro‐Angiogenic, and Anti‐Inflammatory Effects and Promotes Anti‐Aging miRNA Expression Profile in Cerebromicrovascular Endothelial Cells of Aged Rats
Authors: Csiszar Anna , Gautam Tripti , Sosnowska Danuta , Tarantini Stefano , Banki Eszter , Tucsek Zsuzsanna , Toth Peter , Losonczy Gyorgy , Koller Akos , Reglodi Dora , Giles Cory , Wren Jonathan , Sonntag William , Ungavri Zoltan
Published: June 2021

Caloric restriction (CR) exerts cerebrovascular protective effects, but the underlying mechanisms remain elusive. Primary cerebromicrovascular endothelial cells (CMVECs) were isolated from young (3 mo old), aged (24 mo old) and aged CR F344xBN rats. Cellular and mitochondrial oxidative stress was increased in aging and prevented by CR. Expression and transcriptional activity of Nrf2 were reduced in aging, which was prevented by CR. Expression of miR‐144 was upregulated in aged cells, and its overexpression decreased Nrf2 expression in young and aged CR cells. Overexpression of a miR‐144 antagomir in aged cells significantly decreased expression of miR‐144 and upregulated Nrf2. CR prevented age‐related impairment of angiogenic processes (cell proliferation, adhesion to collagen, formation of capillary‐like structures) and inhibited apoptosis. CR also exerts significant anti‐inflammatory effects (decreased the transcriptional activity of NF‐κB aged cells and the pro‐inflammatory shift in endothelial secretome). Collectively, we find that CR confers anti‐oxidative, pro‐angiogenic, and anti‐inflammatory effects, preserving a youthful phenotype in rat CMVECs. CR may improve cerebrovascular function and prevent vascular cognitive impairment.
Exposure to E‐Vapor Extracts Alters Platelet Aggregation, Adhesion and Activation
Authors: Chen Li , Wang Tony , Yin Wei , Rubenstein David
Published: June 2021

Cardiovascular diseases remain to be the leading cause of death in the Western world. Tobacco smoke is a well‐known instigator of cardiovascular diseases, primarily through the delivery of fine particulate matter and oxidative stressors. The effects of e‐cigarettes, a relatively new source of both fine particulate matter and oxidative stressors, on cardiovascular health has not been investigated thoroughly. Here, we aimed to elucidate if the exposure to physiologically relevant levels of e‐vapor can alter platelet functions. To accomplish this aim, we exposed platelets to e‐vapor extracts and quantified platelet aggregation, expression of adhesion, activation and aggregation markers and participation in coagulation based reactions. Platelet aggregation was enhanced after exposure to e‐vapor extracts and for the e‐juice formulations with the highest concentration of nicotine, this enhancement mirrored the effects of mainstream and sidestream tobacco smoke extracts. Altered platelet aggregation was partially induced by an up‐regulation of CD42b. Adhesion potential of platelets was also enhanced via an up‐regulation of CD41a and CD62P, respectively. Each of these adhesion enhancements was e‐juice nicotine concentration and exposure duration dependent. After exposure to e‐vapor, platelets were more likely to participate in coagulation based reactions, suggesting an enhancement of the coagulation cascade. Enhanced platelet activation was at least partially mediated by an increased expression of phosphatidylserine and a release of platelet a‐granules. These enhancements were both time and dose dependent. Thus, our data illustrates preliminary evidence that e‐vapor exposure may alter platelet functions associated with cardiovascular disease progression.
Novel Nickel Superoxide Dismutase Treatment Delays FeCl3‐induced Arterial Thrombosis in Rats
Authors: Sung Yi‐Ting , Chien Chiang‐Ting
Published: June 2021

Nickel complexes, [Ni(H2BA(R)TPP)](ClO4)2 (R = Ph for 1 or iPr for 2), supported by a pentadentate ligand H2BA(R)TPP were synthesized to mimic the nickel superoxide dismutase (NiSOD). Diabetes may exacerbate oxidative stress‐induced thrombosis. We explored the antioxidant activity and its biomedical effects of the synthetic NiSOD in the FeCl3‐induced carotid arterial thrombosis in the type I diabetic rats.

We determined the scavenging reactive oxygen species responses in vitro by a chemiluminescent amplification method. Female Wistar rats in vivo were used and divided into four groups: control rats, streptozotocin (STZ, 60 mg/kg) treated rats, control rats with NiSOD (10 μg/ml), and STZ rats with NiSOD treatment. We investigated the underlying mechanisms of NiSOD on arterial thrombosis by immunohistochemistry and western blotting.

Our data showed that NiSOD dose‐dependently decreased O2‐. and H2O2. The FeCl3‐induced time to occlusion of the carotid artery was 21±5 min in control rats, 21±2 min in STZ rats, 24±4 min in control rats with NiSOD treatment and 28±6 min in STZ rats with NiSOD (10 μg/ml), respectively. By western blot and immunohistochemistry, FeCl3 increased reactive oxygen species production, chemokine (C‐X3‐C motif) ligand 1 (CX3CL1), intercellular adhesion molecule 1 (ICAM‐1), vascular cell adhesion molecule‐1 (VCAM‐1), 4‐hydroxynonenal (4‐HNE) and 3‐nitrotyrosine (3‐NT) expression in the damaged arterial endothelium. NiSOD treatment significantly depressed the level of reactive oxygen species, CX3CLl, ICAM‐1, VCAM‐1, 4‐HNE and 3‐NT in the endothelial areas of control and STZ rats.

These data suggest that a synthesized NiSOD can protect oxidative stress‐induced arterial thrombosis through the actions of antioxidant, anti‐adhesion, anti‐inflammation.
Associations between Plasma Antioxidant Capacity and Skeletal Muscle Antioxidant Gene Expression
Authors: Warren Jonathan , Resuehr Holly , Windham Samuel , Gower Barbara , Fisher Gordon
Published: June 2021

Oxidative stress has been implicated in the etiology of nearly all chronic diseases, including type 2 diabetes, cardiovascular disease, and cancer. In order to maintain redox homeostasis, exogenous antioxidants can be consumed in the diet and endogenous antioxidant enzymes, such as superoxide dismutase (SOD), can be produced within the cells. Antioxidant capacity is often measured in plasma, skeletal muscle, and other cellular compartments within the body. The purpose of this study was to assess associations between plasma antioxidant capacity and skeletal muscle antioxidant gene expression. This study recruited 15 healthy females (BMI=30.97 + 7.87, age=56.5 + 13.4 years) for cross‐sectional analysis. The oxygen radical absorbance capacity assay (ORAC) was used to assess antioxidant capacity in the plasma. Gene expression of SOD1 and SOD2 was assessed in the skeletal muscle from the vastus lateralis using RT‐PCR. The primary finding from this study was a positive association between plasma antioxidant capacity and skeletal muscle SOD1 (r=0.855, p<0.001) and SOD2 (r=0.712, p=0.003) gene expression, suggesting that antioxidant capacity measured in the plasma may be reflective of the antioxidant status within the skeletal muscle. These findings are important given the invasiveness and cost of performing muscle biopsies. While future work needs to be performed to confirm and further validate these findings, these data suggest a more simplistic approach of assessing antioxidant capacity of the plasma may also be reflective of antioxidant status in other tissue compartments.
Design of a LabVIEW‐Based Virtual Instrument for Langendorff‐Prepared Isolated Heart Experiments
Authors: Olson Matthew , Riess Matthias
Published: June 2021

Isolated heart preparations have the advantage of being void of confounding humoral and neuronal input when studying its response to drugs or other interventions. Dynamic changes in left ventricular pressure (LVP) and its derivatives, coronary flow and perfusion pressure, electrocardiogram (ECG), and other variables can be assessed over time. However, a reliable data acquisition system (DAS) is critical to successfully conduct a meaningful experiment. Plug‐and‐play DAS often have the disadvantage of limited flexibility because of proprietary software, limited programmability and/or required specific signal conditioning systems. In contrast, LabVIEW allows maximal user flexibility, but requires a significant amount of programming before use. We report the design and operation of a LabVIEW‐based Virtual Instrument (VI) for Langendorff‐prepared isolated heart experiments. All analog inputs from various signal conditioners are fed into an analog‐digital converter controlled by the VI's DA assistant and sampled and displayed at 200 Hz. Threshold‐controlled HR is calculated from ECG; systolic, diastolic and mean pressures are calculated from LVP; for all less dynamic signals a running 3 sec average is calculated. Continuous or discontinuous data recording can be initiated manually or by an internal or external trigger. Data read‐out is continuously appended into an Excel‐compatible file. Thus, the described VI turns LabVIEW into an affordable alternative to more rigid and expensive DAS while providing maximal flexibility for future adjustments. Supported by VA (CARA‐026‐10F), NIH & institutional funds.
Pretreatment of Human Polymorphonuclear Leukocytes (PMN) with a New Carbon Monoxide (CO)‐Releasing Molecule (CORM401) Inhibits PMN Migration across Vascular Endothelial Cells
Authors: Inoue Ken , Woo Martin , Patterson Eric , Potter Richard F. , Capretta Alfredo , Fraser Douglas D. , Cepinskas Gediminas
Published: June 2021

Background

We have demonstrated that carbon monoxide (CO)‐releasing molecules (CORMs) reduce septic inflammation by interfering with PMN recruitment to the inflamed organs. In this study, we assessed the effects/mechanisms of a newly synthesized Mn2+‐based water‐soluble CORM (CORM401) on PMN adhesion(A)/transendothelial migration(TM) in an experimental model of endotoxemia in vitro.

Methods

Human umbilical vein endothelial cells (HUVEC) grown on parallel flow channels were stimulated with LPS (1μg/ml; 6 hrs) and interacted with freshly isolated PMN (pretreated for 30 min with CORM401 or its inactive compound, iCORM401; 100μM) for 5 min in the presence of 1.0 dyn/cm2 shear stress. Subsequently, HUVEC:PMN co‐cultures were additionally perfused for 20 min with medium containing CORM/iCORM401. Video and confocal microscopy were used to analyze PMN A/TM.

Results

Stimulation of HUVEC with LPS significantly increased PMN A (0.6+/‐0.1 vs 30.9+/‐7.6 cells/mm2; p<0.05) and TM (0.0 vs 41.7+/‐6.8%; p<0.001). Pretreatment of PMN with CORM401 had no effect on PMN A, however significantly reduced PMN TM (41.7+/‐6.8% vs 15.2+/‐4.3; p<0.01). The above findings were confirmed employing confocal microscopy.

Conclusion

CORM401 interferes with PMN recruitment by specific suppression of PMN migratory potential. (HSFO 393, IRF‐25‐12).
Ischemic Tolerance and Conventional Preconditioning are Impaired by Chronic β1‐Blockade
Authors: See Hoe Louise , Schilling Jan , Busija Anna , Roth David , Patel Hemal , Peart Jason
Published: June 2021

β‐adrenoceptor (β‐AR) antagonists are commonly prescribed to ischemic heart disease (IHD) patients. In addition to age and disease, β‐blockade may impair efficacies of cardioprotective approaches. We assessed the effects of chronic β1‐AR antagonism on myocardial tolerance to ischemia‐reperfusion (I/R), and the efficacies of ischemic preconditioning (IPC) and sustained ligand‐activated preconditioning (SLP) in murine hearts. Male C57/Bl6 mice received β1‐AR‐blocker atenolol for 4 weeks (0.5 g/L in drinking water) before subcutaneous implantation of morphine (SLP) or placebo pellets 5 days prior to analysis of ischemic outcomes ex vivo. Atenolol significantly reduced in vivo heart rate and responses to isoproterenol in all groups, an effect exaggerated with SLP. Control (placebo) hearts exhibited significant post‐ischemic contractile depression, with ~50% recovery of developed pressure, significant diastolic dysfunction and lactate dehydrogenase (LDH) release, effects inflated by chronic β1‐AR blockade with atenolol. Both IPC and SLP significantly improved post‐ischemic outcomes and LDH release (~50% improvement). Interestingly, IPC protection was negated by chronic atenolol treatment, yet SLP‐mediated protection persisted irrespective of β1‐AR blockade. Western blot analysis suggests Src phosphorylation with IPC was blocked by atenolol. Data indicate that chronic β1‐AR blockade impairs intrinsic ischemic tolerance and classical preconditioning responses whereas novel SLP retains protective efficacy likely due to distinct signaling mechanisms.
Contrasting Effects of Ang II Receptors Following Ischemia‐Reperfusion in Ang II‐preconditioned Rat Hearts
Authors: Nuñez Rebeca , Castro Miriam , Javadov Sabzali , Escobales Nelson
Published: June 2021

Ang II‐preconditioning (APC) significantly improves post‐ischemic recovery of cardiac function although its cardioprotective mechanisms remain largely unknown. To evaluate the role of the Ang II receptors in APC, isolated‐perfused rat hearts were pre‐treated (15 min) with losartan (AT1R blocker, 10µM) and/or PD123319 (AT2R blocker, 1µM) prior to 4 cycles (5 min each) of Ang II (10nM) with or without drugs, followed by 30 min of global ischemia and 90 min of reperfusion (IR, n=4/group). The drugs were absent during the reperfusion period. Left‐ventricular developed pressure (LVDP), the first derivative of developed pressure (+dP/dt), the rate pressure product (RPP) and LDH release were monitored and infarct size was evaluated at the end of reperfusion. Losartan significantly reduced cardiac function compared to APC during the pre‐ischemic (PI) and post‐ischemic (PO) periods (35%, P<0.05). PD123319 did not affect cardiac function during PI but abolished the AT1R‐dependent component when co‐infused with losartan. PD123319 also increased cardiac function 2‐fold (P<0.05) during PO with or without losartan, indicating that the effect of AT2R blockade was independent of APC. These actions of AT1R and AT2R blockade were associated with significant reductions in infarct size (64%, P<0.05) and LDH release (72%, P<0.05) compared with controls. Both blockers also reduced LDH release (45%, P<0.05), but only losartan inhibited infarct size (64%, P<0.05) compared with APC. These findings suggest that whereas AT1Rs promote cardiac function and are critical for APC, AT2Rs suppress cardiac function after IR. Supported by: RCMI Program grant G12MD007600, the Univ. of Puerto Rico, and NIH grant SCIHL118669 (SJ).
A Role for Hydrogen Sulfide in Obesity‐dependent Microvascular Remodeling
Authors: Candela Joseph , Velmurugan Gopal , Lin Vivian , Chang Christopher , White Carl
Published: June 2021

Remodeling of the microvasculature occurs with obesity. Based on recent observations that impaired H2S signaling is associated with cardiovascular pathologies, the current study was designed to test the hypothesis that altered H2S homeostasis is involved in driving the remodeling process in a diet‐induced mouse model of obesity. The structural and passive mechanical properties of mesenteric arterioles isolated from 30 week‐old lean and obese mice were assessed using pressure myography. Vessels were loaded with the H2S indicator SF7‐AM and imaged confocally to determine H2S levels in the smooth muscle layer. Remodeling gene expression was assessed using qRT‐PCR and histological staining approaches used to quantify vessel collagen and elastin. Obesity was associated with increased arteriolar wall to lumen ratio, decreased compliance and a loss of elasticity. In addition, the vessel walls from obese animals contained more collagen and less elastin, as well increased expression of matrix metalloproteinases; connective tissue growth factor; collagen and fibronectin. Assessment of H2S levels revealed markedly lower levels in arterioles from obese compared to lean mice. Intriguingly, reversal of H2S depletion by overnight incubation with H2S donor reduced remodeling gene expression in arterioles from the obese mice. These data suggest that during obesity the microvasculature can undergo structural remodeling that is associated with depleted H2S, and demonstrate the potential for exogenous H2S repletion to modify the process. Supported by the American Heart Association and a Chicago Medical School/Advocate Lutheran General Hospital Pilot Grant.
BAY 60‐2770, An Activator of Soluble Guanylate Cyclase, Attenuates Postischemic Brain Injury in H129 WTMice
Authors: Wang Meifang , Wang Walter , Wang Derek , Jones Allan , Korthuis Ronald
Published: June 2021

Our previous studies showed that activation of soluble Guanylate Cyclase (sGC) protects against both postischemic intestinal and cardiac injury in wild type, heme‐oxygenase‐1 ‐/‐ (KO), and eNOS KO mice. The aim of this study was to determine whether a similar protective effect of sGC activation by BAY 60‐2770 (BAY 60) would occur in postischemic brain. In this study, leukocyte rolling (LR) and adhesion (LA) were quantified in single pial venules of male wild‐type (H129) mice using intravital fluorescence microscopy after two and three hours of reperfusion following 20 min of ischemia produced by bilateral common carotid artery occlusion. Levels of tumor necrosis factor‐a (TNF‐a) were measured in brain samples obtained after three hour reperfusion. Preconditioning with BAY 60 either 10 min (acute) or 24 hr (delayed) prior to ischemia/reperfusion (I/R) significantly reduced postischemic LR but had no effect on LA at both two and three hour reperfusion, while the elevated TNF‐a levels induced by brain I/R were significantly attenuated in both the hippocampus and cerebrum. These findings indicate that both acute and 24h BAY 60 treatment prior to brain I/R limits postischemic inflammation, and may have therapeutic value for suppressing stroke‐mediated damage. Supported by grants from the NIH (AA‐014945 and HL‐095486). BAY 60‐2770 was a gift from Bayer Schering Pharma AG.
Transient Impairment in Endothelial Vasodilation Following Excessive High‐Volume Endurance Training in Collegiate Female Swimmers
Authors: Van Guilder Gary , Weihl Fawn
Published: June 2021

Excessive endurance training (e.g., marathons, triathlon, ultra‐distance running etc.) has been linked with adverse structural remodeling of the heart and large arteries, yet data concerning its impact on the microcirculation is not clear. Moreover, while collegiate‐level endurance athletes often undergo similar volumes of training, it is unknown if they also experience vascular abnormalities, particularly reduced endothelial function. The aim of this study was to determine the impact of excessive, high‐volume endurance training and low‐volume tapered training on endothelial vasodilation. Microvascular vasodilation was assessed by the reactive hyperemia index (RHI) in 10 female NCAA Division 1 collegiate swimmers after 4 weeks of high‐volume training, and subsequently, after 3 weeks of low‐volume tapered training. The RHI was calculated as the ratio of the digital pulse volume amplitude following 5 minutes of brachial artery ischemia to the baseline amplitude, divided by the control arm ratio. High‐volume training consisted of 6 swims/wk at ~100% VO2max intervals for 120 min/practice (~8000 yd/swim). Low‐volume tapered training consisted of 3‐5 swims/wk at ~50% VO2max for 60 min/practice (~4000 yd/swim). All experiments conformed to the Declaration of Helsinki. The RHI (1.7±0.5) was markedly reduced in athletes after high‐volume training. However, after tapered training, the RHI improved by ~33% (2.3±0.4; P=0.02 versus high‐volume training). The results indicate that endothelial vasodilation is diminished following excessive swim training. However, the impairment is transient as a period of tapered training restored vasodilation in female collegiate swimmers.
Overexpression of MnSOD Does Not Improve Endothelial Function in Hypercholesterolemic Mice
Authors: Roos Carolyn , Hagler Michael , Zhang Bin , Richardson Arlan , Miller Jordan
Published: June 2021

We previously reported that MnSOD‐deficiency does not cause overt vasomotor dysfunction in aged or hypercholesterolemic mice. To determine whether increasing MnSOD protects against vasomotor dysfunction and deleterious molecular changes in atherosclerosis, we crossed hypercholesterolemic mice with mice overexpressing MnSOD to test the hypothesis that lifelong increases in MnSOD protect against vasomotor dysfunction. We used Ldlr‐/‐/ApoB100/100 mice that were wild‐type (MnSOD0/0) or transgenic (MnSODTg/0) and fed a western diet for 6 months. We used organ bath chambers to measure aortic endothelium‐dependent relaxation (relaxation to acetylcholine, Ach), and mRNA from aortic arch was used for qRT‐PCR. Surprisingly, relaxation to Ach was unchanged between MnSOD0/0 and MnSODTg/0 mice, as was relaxation to sodium nitroprusside. As expected, gene expression of MnSOD was significantly increased in the MnSODTg/0 mice compared to MnSOD0/0 mice. Unlike our findings in MnSOD+/‐ mice, however (where Nox2 was increased), Nox2 expression was unchanged between MnSOD0/0 and MnSODTg/0 mice. Importantly, markers of osteogenesis such as Runx2 and BMP2 were unchanged between genotypes. Furthermore, MnSOD overexpression did not alter cellular senescence markers. Collectively, our data support the surprising conclusion that physiologically relevant increases in MnSOD do not significantly affect endothelial function or molecular regulators of histopathological changes in advanced atherosclerosis in hypercholesterolemic mice.
Impairment of Vascular Function in a Mouse Model of Neurofibromatosis Type 1
Authors: Jett Kimberly , Chohan Harleen , Cui Jason , Tehrani Arash , Friedman Jan , van Breemen Cornelis , Esfandiarei Mitra
Published: June 2021

Neurofibromatosis 1 (NF1) is an autosomal dominant disorder, characterized by multiple café‐au‐lait spots, iris harmartomas, multiple nerve sheath tumors. Patients also present with heart and cerebrovascular disease, ischemia, or aneurysm. Though vasculopathy is well documented in NF1 patients, the pathophysiology is poorly understood. The objective of this study was to investigate the function and structural integrity of the thoracic aorta in a well‐established mouse model of NF1 (6‐month old). We observed a significant increase in contraction in response to depolarization of vascular smooth muscle and endothelial cells in Nf1+/‐ mice, but diminished contraction in response to phenylephrine. Interestingly, endothelium‐dependent relaxation was significantly higher in Nf1+/‐ mice, which was completely inhibited by the nitric oxide synthase (NOS) inhibitor, suggesting the relaxation results from nitric oxide (NO) production. Consistent with increased NO production, protein expression of endothelial NOS (eNOS), phospho‐eNOS, and the phospho‐Akt were increased in Nf1+/‐ aorta. Histological examination revealed that alteration in aortic function is also associated with elastin fiber disorganization within the aortic wall. This study, for the first time, underscores the pathological events underlying vascular complications in NF1, shedding light on potential new therapeutic targets to address vascular dysfunctions in NF1 patients. The presented study was funded by the Children's Tumor Foundation and the Canadian Institutes of Health Research.
Assessment of 18F‐NaF Positron Emission Tomography Imaging for Early Coronary Artery Calcification
Authors: McKenney Mikaela , Territo Paul , Salavati Ali , Houshmand Sina , Persohn Scott , Liang Yun , Alloosh Mouhamad , Moe Sharon , Weaver Connie , Alavi Abass , Sturek Michael
Published: June 2021

18F‐NaF uptake has been investigated as an in vivo biomarker of coronary artery calcification (CAC) in humans. CAC increases risk of fatal cardiac events in coronary artery disease (CAD) patients, thus making early diagnosis and clinical intervention extremely important. We assessed 18F‐NaF positron emission tomography (PET) as a diagnostic tool for early CAC in a preclinical swine model of metabolic syndrome (MetS) and CAD by comparing multiple imaging modalities: PET, computed tomography (CT), intravascular ultrasound (IVUS), and histopathology for their sensitivity. MetS Ossabaw swine (N=11) with early‐stage CAD underwent ECG‐gated 18F‐NaF PET/CT scans. Global cardiac and coronary tracking techniques were used to measure 18F‐NaF uptake. MetS swine had almost 2‐fold increased 18F‐NaF uptake in the conduit coronary arteries (p<0.05) and 2.5‐fold increased global molecular calcium score (p<0.05) compared to lean (N=3). IVUS resolved calcification in only 1 MetS pig. All pigs had Agatston CT calcium scores of 0. Histology revealed microcalcifications present in 36% of MetS pigs (NS). This is the first report of 18F‐NaF uptake at an early stage of CAD and microcalcification prior to clinically significant, ossified lesions resolvable by IVUS and CT.
Inhibitory effect of Xanthoceras sorbifolia on TNF‐α‐induced vascular dysfunction in human umbilical vein endothelial cells
Authors: Yoon Jung Joo , Lee Yun Jung , Choi Eun Sik , Ahn You Mee , Han Byung Hyuk , Kang Dae Gill , Lee Ho Sub
Published: June 2021

Xanthoceras sorbifolia Bunge, which belongs to the Sapindaceae family, is a shrub in Inner Mongolia and China. It has been used as a folk medicine for various diseases including hypertension and enuresis. In human umbilical vein endothelial cells (HUVEC), ethanol extract of seed from the Xanthoceras sorbifolia (EXS) significantly decreased TNF‐α‐induced expression of cell adhesion molecules such as intracellular adhesion molecule‐1 (ICAM‐1), vascular cell adhesion molecule‐1 (VCAM‐1), and endothelial cell selectin (E‐selectin) in a dose‐dependent manner. Pre‐treatment of EXS significantly inhibited the translocation and transcriptional activity of NF‐κB increased by TNF‐α. In addition, EXS also significantly inhibited the formation of intracellular reactive oxygen species (ROS). Furthermore, we found that the vascular protective effects of EXS were linked to the up‐regulation of heme oxygenase‐1 (HO‐1) and nuclear factor E2‐related factor‐2 (Nrf2) expressions in HUVEC. The inhibitory effects of EXS on the TNF‐α‐induced vascular inflammation were partially reversed by an inhibitor of HO‐1, tin protoporphyrin IX (SnPP), while increased by an inducer of HO‐1, cobalt protoporphyrin IX (CoPP).

In conclusion, these results suggested that EXS ameliorated TNF‐α‐induced vascular inflammation, possibly through the disturbing ROS/NF‐κB pathway and activation of Nrf‐2/HO‐1. Hence, EXS plays a key role in the vascular inflammation and further prevents the development of atherosclerosis.
Effects of Hydrogen Sulfide on Circulation
Authors: Sonobe Takashi , Haouzi Philippe
Published: June 2021

Hydrogen sulfide (H2S) has been suggested to relax the vascular smooth muscles and produce a vasodilation. However, it remains unclear whether endogenous H2S produced in the vessels, if any, can produce a vasodilatory effect, which has a relevant physiological or clinical meaning, as concentrations of H2S used in vitro to produce these effects are within a toxic range.

In urethane anesthetized mechanically ventilated rats, NaHS was intravenously infused in a stepwise manner to produce an increase in alveolar H2S partial pressure and thus arterial concentration of free H2S (CgH2S) from undetectable up to levels we have previously shown to depress breathing control.

Compared to saline infusion, blood pressure started to decrease significantly along with the peripheral vascular resistance by ‐19 ± 5%, (P<0.01) when CgH2S reached ~ 1 microM. As soon as CgH2S exceeded these levels, cardiac output decreased with a decrease in ventricular pressure, along with a significant elevation of blood lactate. Whenever H2S exposure was maintained at a higher level, above 3‐4 microM of CgH2S, a profound inhibition of cardiac contractility occurred leading to cardiac arrest by a pulseless electrical activity.

In conclusion, a small reduction in peripheral vascular resistance was found in the rat at relatively low H2S concentrations. These changes were extremely modest with an alarming overlap with the levels of H2S altering cardiac contractility.
Hydrogen Sulfide (H2S): A Novel Mediator in Adenosine A2A Receptor‐induced Vasorelaxation
Authors: Ponnoth Dovenia , Nayeem Mohammed , Tilley Stephen , Ledent Catherine , Mustafa S Jamal
Published: June 2021

Previously, we have shown that adenosine‐induced aortic relaxation occurs through activation of A2A adenosine receptor (AR) via opening of KATP channels (Ponnoth et al., 2009, 2012). In this study, we investigated whether H2S, an endogenous gaseous mediator of vasorelaxation, contributes to A2A‐induced aortic relaxation. Organ bath and western blot experiments were done using isolated aortas from A2AKO and WT mice. H2S donor sodium hydrosulfide (NaHS; 10‐3M) produced significantly higher relaxation in WT aorta compared to A2AKO (54.63±2.14% vs.17.16±5.84%). Removal of endothelium had no effect on NaHS responses in WT and A2AKO, neither were responses different in A1KO or A2BKO compared to WT. KATP blocker glibenclamide significantly inhibited NaHS responses in both WT (from relaxation of 54.63±2.14% to contraction of 17.76±6.46%) and A2AKO (from relaxation of 17.16±5.84% to contraction of 52.43±9.23%) and this effect was more pronounced in A2AKO. Non‐selective adenosine analog NECA (10‐5M) response in WT was changed to higher contraction in the presence of PAG [50uM, inhibitor of H2S synthesizing enzyme cystathionine γ‐lyase (CSE)] while no effect was observed in A2AKO. In addition, the expression of CSE was significantly lower in A2AKO aorta (64.27±3.67% vs 100±10.03% in WT). These data suggest that H2S may contribute toA2A AR‐induced aortic relaxation through KATP channels. Supported by HL027339,HL094447
Resuscitation with whole body cooling prevents multiple organ damage after hemorrhagic shock in rats
Authors: Wang Chung‐Han , Lin Hung‐Jung , Hsu Chien‐Chin , Huang Huei‐Sheng
Published: June 2021

Whole body cooling (WBC) has been shown to improve survival in hemorrhagic shock (HS) rat studies. We hypothesized that induction of WBC would be beneficial for multiple organ damage (MOD) during HS resuscitation. Light anesthesia was induced with ketamine in rats, and spontaneous breathing was maintained. Rectal temperature (Tr) was monitored at about 36oC. HS was induced by blood withdrawal of 6ml/100g body weight during a 60‐minute period, following by blood transfusion for a 30‐minute period. Immediately after blood transfusion, rats were randomized into three groups of 10 rats each: group 1, untreated HS rats maintained at Tr 36.5oC; group 2, HS rats maintained to Tr 37.5oC (with 36oC water blanket temperature); and group 3, HS rats maintained to Tr 34oC (with 16oC water blanket temperature). Rats were controlled at each target Tr for 30 min. It was found that resuscitation with blood, but not WBC, induced significant multiple organ dysfunction, manifested by a high plasma level of aspartate aminotransferase, alanine aminotransferase, blood urea nitrogen, creatinine, and lactate dehydrogenase. In addition, HS rats received blood transfusion alone has significant MOD, evidenced by a high score of lung, kidney, or liver. The MOD caused by HS were significantly attenuated by WBC, in particular with the 16oC WBC. Our data indicate that resuscitation with WBC prevents multiple organ dysfunction or damage after acute HS in rats.
Role for DNA damage and epigenetic signaling in coronary artery diseases
Authors: Meloche Jolyane , Henry Sarah , Tremblay Eve , Charbonneau Eric , Provencher Steeve , Bonnet Sebastien
Published: June 2021

Coronary artery disease (CAD) is the most common cause of heart attacks. Evidence demonstrated that coronary artery stenosis have increased inflammation leading to sustained DNA damage. In cancer, through the activation of poly(ADP)ribose‐polymerase 1 (PARP‐1), a critical enzyme acting as a DNA damage sensor, and the epigenetic reader Bromodomain‐containing protein 4 (BRD4), DNA damage promotes mitochondrial/metabolic dysfunction contributing to cell proliferation. Thus, we hypothesized that increased inflammation‐induced DNA damage in remodeled coronary arteries promotes BRD4 and PARP‐1 expression, triggering CoASMC proliferation. Both coronary arteries (n=10) and primary cultured CoASMC (n=4) from patients with stenosis exhibit increased (p<0.05) DNA damage (γ‐H2AX and 53BP1), PARP‐1 and BRD4 protein expression (western blot). This pathological phenotype significantly increased (p<0.05) cell proliferation (Ki67, MTT assay) through a mitochondrial (TMRM) and metabolic dysfunction (Seahorse XFe24) compared to control cells (n=3). Furthermore, co‐culture of CoASMC with peripheral blood mononuclear cells (PBMC) isolated from symptomatic CAD patients promotes BRD4 expression (qRT‐PCR). Finally, experimental rat model of carotid angioplasty exhibit a similar phenotype that the one seen in CAD patients. Our study suggests an important role for PARP‐1/BRD4 axis in CoASMC proliferation in CAD.

A “Fonds de recherche Quebec‐Sante” graduate scholarship to Jolyane Meloche, as well as Canadian Institutes of Health Research grants and a Canadian Research Chair in Vascular Remodeling Diseases to Sebastien Bonnet supported this work.
Aging Selectively Attenuates L‐Type Calcium Currents in Resistance Coronary Arteries
Authors: Mansour Fathi , Hassan Mohammed , Khan Abdul Aleem , Albarwani Sulayma
Published: June 2021

The current density of L‐type voltage‐gated calcium (L‐VGC) channels was reported to be inversely proportional to the diameter of coronary arteries. Since aging is a major risk factor for coronary artery disease, we investigated if the above relationship is altered with aging. Smooth muscle cells were isolated from coronary arteries of young (3‐4 months) and old (22‐26 months) male F344 rats. Whole‐cell L‐VGC currents were recorded using 10 mM Ba2+ as charge carrier from small (˂100µm) and large (250 to 400 µm) diameter arteries. Student's t‐test was used to compare peak inward current densities (pA/pF; mean± S.E.M) between young and old arteries of similar size and the 2‐way ANOVA was used to compare all four groups (P<0.05). In large arteries, current densities were not significantly different between old (‐5.44 ± 0.92; n=13) and young (‐4.33 ± 0.81, n=13) rats. In small arteries, current densities from old (‐3.66 ± 0.41; n=36) were reduced by 2.4 fold compared to those from young rats (‐8.8 ± 0.88; n=27); with similar V0.5 for both activation and inactivation voltages. Current densities recorded from large arteries of young and old rats and from small arteries of old rats were not significantly different. However, current densities recorded from small arteries of young rats were significantly higher than those from the other three groups. L‐type current density of small resistance arteries of young rats is significantly higher than in large arteries. This inverse diameter‐current density relationship is lost with aging. We conclude that aging selectively affects the density of L‐VGC currents of small resistance coronary arteries.

This work is funded by The Research Council of Oman
Obstructive Sleep Apnea Attenuates the Cerebrovascular Circadian Clock and Rhythms in Vascular Function
Authors: Durgan David , Lloyd Eric , Bryan Robert
Published: June 2021

Molecular circadian clock components oscillate in cells of the cardiovascular system. These clocks allow the cell to respond to a stimulus with proper timing and magnitude. Alterations in these rhythms are associated with and/or contribute to various cardiovascular diseases. We tested the hypothesis that obstructive sleep apnea (OSA) disrupts the normal rhythms of the cerebrovascular circadian clock and vascular function. OSA was produced in rats by remotely inflating a balloon placed in the trachea. Unanesthetized rats underwent 60 apneas/ hour for 8 hours/ day (sleep phase). Following 2 weeks of sham or OSA, cerebral arteries were isolated at; the transition from dark‐to‐light (i.e., zeitgeber time (ZT) 0), 6, 12, or 18. We identified significant diurnal rhythms in mRNA expression levels of the circadian clock genes period 1 (per1), period 2 (per2), and the clock controlled gene albumin d‐site binding protein (dbp) in cerebral vessels of sham rats, which were significantly attenuated following OSA (p<0.05 for each). Perfused posterior cerebral arteries from sham rats exhibit a significant diurnal rhythm in the sensitivity to ATP induced vasodilation, that was most responsive at the beginning of the awake phase (p<0.05). This rhythm was abolished in OSA arteries, which exhibit diminished ATP sensitivity independent of the time‐of‐day (p<0.05). In the presence of L‐NAME the diurnal rhythm in ATP sensitivity was abolished in sham vessels and not different from OSA, suggesting cerebral arteries exhibit a diurnal rhythm in nitric oxide induced vasodilation that is impaired following OSA. In conclusion, OSA significantly attenuates the diurnal rhythms of the cerebrovascular circadian clock and vascular function. Funded by 1R01NS080531
The effect of an acute increase in central blood volume on hypercapnia‐induced attenuation in dynamic cerebral autoregulation
Authors: Ogoh Shigehiko , Hirasawa Ai , Sugawara Jun , Nakahara Hidehiro , Ueda Shinya , Shoemaker J , Miyamoto Tadayoshi
Published: June 2021

It is well established that hypercapnia attenuates dynamic cerebral autoregulation. The impact of central blood volume on cerebral blood flow is controversial. The purpose of the present study was to examine whether hypercapnia‐induced attenuation in dynamic cerebral autoregulation is modified by acute central hypervolemia. Nine young healthy subjects voluntarily participated in this study. In order to measure dynamic cerebral autoregulation during normocapnic and hypercapnic (5%) conditions, the change in middle cerebral artery mean blood flow velocity (MCA Vmean) was analyzed during acute hypotension caused by two methods: 1) thigh‐cuff occlusion release (without change in central blood volume) and 2) lower body negative pressure (‐50 mmHg, LBNP) release (with acute increase in central blood volume). As expected, hypercapnia decreased the rate of regulation, as an index of dynamic cerebral autoregulation (0.236±0.053 and 0.167±0.074 sec‐1, respectively, P=0.025). In contrast, this attenuation was disappeared during central hypervolemia (P=0.574). This phenomenon may be associated with hypervolemia‐induced attenuation of dynamic cerebral autoregulation (P=0.009). These findings suggest that an acute change in central blood volume modifies carbon dioxide‐induced changes in dynamic cerebral autoregulation.
Reduced Dilatory Capacityof Brainstem Parenchymal Arteries of Young Spontaneously Hypertensive Rats
Authors: Mayorov Dmitry , Kasparov Sergey , Paton Julian
Published: June 2021

Our recent data suggest that spontaneously hypertensive rats (SHR) show reduced functional hyperemia and impaired relaxation of vertebral and basilar arteries. Here, using brainstem slices from pre‐hypertensive SHR (PHSHR, P21‐P30), young hypertensive SHR (YHSHR, P45‐P70) and age‐matched normotensive Wistar rats, we compared vascular dilatory capacity of both pial and penetrating parenchymal arterioles. Changes in vascular diameter in response to application of vasodilator agents, adenosine (1‐10 µM) and sodium nitroprusside (1‐10 µM), were assessed after pre‐constriction with a thromboxane agonist (U46619 70 nM). In PHSHR and aged‐matched Wistar rats, treatment with U46619 constricted parenchymal arterioles to 82±7% and 88±2% of their resting diameters: 15±3μm and 16±2μm, respectively. These responses remained unchanged in YHSHR and their aged‐matched controls. Adenosine reversed the U46619‐induced vasoconstriction by 24% and 30% in PHSHR and Wistar controls, respectively. In contrast, adenosine failed to reduce vasoconstriction in YHSHR, although its vasodilator efficiency in aged‐matched Wistar rats remained unaltered. Likewise, superfusion with sodium nitroprusside reduced the U46619‐induced vasoconstriction in penetrating arterioles from PHSHR, but not YHSHR. Intriguingly, vasodilator efficiency of adenosine in pial arterioles of a similar size (21±4 μm) was preserved in YHSHR. These results suggest that the dilatory capacity of brainstem parenchymal arteries is reduced in YHSHR. Whether this contributes to neurogenic hypertension remains to be determined. The distinct responses of parenchymal versus pial arterioles in YHSHR suggest that the impaired dilatory reserve cannot be ascribed to increased blood pressure per se. BHF funded research.
Blood Pressure and Cardiovascular Health in College Students and Campus Faculty/Staff
Authors: Lenzo Jessica , Cromwell Christina , Oakman Joyann , Aichele Kristin , Neal Michael , Perez Avery , Thiele Karla , Santaniello Erica , Bye Naomi , Hill Jessica , Evans Rachel , Wisdo Tia , Chavis Lauren , Getty Allyson , Louth Victoria , Feairheller Deborah
Published: June 2021

Previous research indicates that cardiovascular (CV) disease mortality has decreased in populations ages 55‐74, but has not for younger groups, suggesting a need for research in CV health in younger adults. We compared CV health measures between relatively healthy young (college students) and middle‐aged (faculty/staff) adults who were matched for body mass index (BMI) and blood pressure (BP) dipping status. Measures of CV health, including: VO2max, clinical BP, ambulatory blood pressure (ABP), BMI, and fasted plasma glucose/cholesterol were measured in students (n=10, 20.2±0.6 yrs) and faculty/staff (n=9, 44.8±8.3 yrs) of a small college campus. There was no difference in VO2max, glucose,/cholesterol, or clinical BP measures between the groups, but there were differences in diastolic 24 hr ABP, diastolic daytime ABP, and diastolic nighttime ABP (p<0.05 for all). In students, we found no relationships between ABP and CV health variables. However, in faculty/staff, there was a relationship between 24 hr systolic ABP and daytime systolic ABP with glucose, HDL, and triglycerides (p<0.05 for all). Our results indicate that, although there are no differences in BP dipping status, BMI, and clinical BP measures between the groups, there is a relationship between glucose, HDL, and triglycerides with ABP in only the faculty/staff adult group. This suggests that other measures, not examined in this study, may differ between the two groups.