bluuebunny/crossref_metadata_2025_split huggingface dataset:
Expression of TLR9 in Horse, Cow, and Human Lung
Authors: Schneberger David , Caldwell Sarah , Suri Sarabjeet Singh , Kanthan Rani , Singh Baljit 
Published: June 2021

Toll‐like receptor 9 (TLR9) is the receptor used for responding to bacterial DNA in many species. Recent work has shown that this receptor is expressed in a diverse set of cells within the lung. However, much of this work has been done in tumors, explanted cells, or cell cultures. We examined the in situ expression of TLR9 in the lung of cattle, horses and humans. The data show expression of TLR9 in monocytes, airway epithelial cells, and capillary endothelium in the lungs of all the species. Pulmonary intravascular macrophages of the horse and cattle also express TLR9. Immno‐electron microscopy revealed TLR9 expression in the cytoplasm and, more interestingly, in the nucleus of pulmonary intravascular macrophages (PIMs) and other lung cells. Lung inflammation as a result of E. coli LPS (horses), Mannheimia hemolytica infection (calves), or sepsis (human) resulted in an influx of TLR9‐positive cells. Finally, we show that the LPS‐induced increase in TLR9 gene transcription in the horse lung was abrogated by pre‐treatment with gadolinium chloride to deplete PIMs which demonstrates PIMs as a major source of TLR9 in the horse lung. We conclude that TLR9 is constitutively expressed in lungs of horse, cow and human. The implications of TLR9 expression in PIMs in the horse and cow for infections need to be clarified. (NSERC)Grant Funding SourceNSERC
AMPK: A Critical Metabolic Signal
Authors: Goodyear Laurie J. , Koh Ho‐Jin , Fujii Nobuharu , Toyoda Taro , Witczak Carol A. , Middelbeek Jan Willem , Jung Michelle , Hirshman Michael 
Published: June 2021

The AMP‐activating protein kinase (AMPK) and its upstream kinase LKB1 are serine/threonine kinases that have been proposed to function as master regulators for a diverse array of cellular processes. In skeletal muscle, there is emerging evidence that AMPK and LKB1 regulate multiple metabolic functions, including glucose transport. Our group and others have generated mice lacking AMPK activity in skeletal muscle, as well as muscle‐specific LKB1 knockout mice. In this talk, the putative role of LKB1 and AMPK in regulating skeletal muscle metabolism will be discussed. In addition, recent data will be shown on sucrose non‐fermenting AMPK‐related kinase (SNARK), an AMPK‐related kinase that has previously been shown to be regulated by multiple cellular stresses in kidney and several tumor cell lines. This presentation will discuss our work showing that exercise and contractile activity increase SNARK activity in skeletal muscle. Data will also be presented suggesting a role for SNARK in glucose transport regulation in skeletal muscle.This research is supported by the American Physiological Society Postdoctoral Fellowship in Physiological Genomics (HJK) and NIH grants AR45670 and DK68626 (LJG).
Supratherapeutic Insulin Alters Intracellular pH in Human Kidney Tubular Epithelial Cells
Authors: Kruss Szilvia Ilona , Valyi‐Nagy Klara , Setty Suman 
Published: June 2021

BackgroundThe profile of metabolic syndrome includes high fasting sugars and hypertension. Intracellular pH (pHi) is vital for the maintenance of the normal metabolic function of human kidney tubular epithelial cells (HK‐2). In the present study we investigated whether high glucose levels and two common agents that are used to treat metabolic syndrome, insulin and lisinopril have an effect on pHi in cultured HK‐2 cells.MethodsImmortalized tubular kidney HK‐2 cells were cultured in media containing normal (5 mM) or increased (25 mM) amounts of glucose. Cultures were then exposed to therapeutic or supratherapeutic (3 times higher) doses of insulin and lisinopril and consequent changes in pHi were determined using a SNARF 5‐(and‐6)‐carboxy SNARF®‐1, acetoxymethyl ester agent (Invitrogen, Carlsbad) at 8 days after treatment.ResultspHi was significantly higher (p<.05) in cells treated with 25 mM versus 5 mM glucose. Supratherapeutic insulin treatment was associated with significantly (p<.01) increased pHi relative to cells cultured in normal and increased glucose. Intracellular pH in the supratherapeutic insulin condition was also significantly elevated (p<.01) relative to lisinopril treated cells.ConclusionsIncreased glucose and supratherapeutic insulin lead to increased (more basic) pHi in human kidney tubular epithelial cells. Altered pHi in these cells may have extensive effects on a variety of cellular functions, including promoting insulin resistance. Furthermore, alkalinic changes could assist the propagation of certain types of cancers which will be the basis of further research in our laboratory.
Influence of Endogenous Testosterone on Vascular Endothelium‐Leukocyte Interaction in Spontaneously Hypertensive Rats (SHRs)
Authors: Filgueira Fernando Paranaiba , Lobato Núbia Souza , dos Santos Rosângela Aparecida , Oliveira Maria Aparecida , Fortes Zuleica Bruno , Tostes Rita , Carvalho Maria Helena Catelli 
Published: June 2021

AimEndogenous testosterone exerts influence on the vascular endothelium dysfunction in hypertension, and inflammation may play a important role in the onset and progress of cardiovascular diseases. So, we decided to evaluate the impact of castration on the leukocyte behavior in the SHR mesenteric post‐capillary venules.Methods and ResultsMale SHRs were castrated at 12 weeks of age and the leukocyte behavior was studied in vivo‐in situ by intravital microscopy. It was investigated after 6 weeks of orchidectomy and compared to the ones in the intact group. Castration reduced the number of leukocytes rolling and sticking along the venular endothelium, but not modified migrating after leukotriene B4 stimulation. P‐selectin protein expression (immunohistochemistry) as well as VCAM‐1 and PECAM‐1 gene expression (Real Time PCR) were reduced by castration and might be involved in the reduced rollers and stickers. However no difference was detected in ICAM‐1 protein and gene expression between groups. Venular shear rate, leukocyte and blood flow velocity, venular diameter and leukocyte counts were similar between groups. Castration reduced testosterone levels (EIA Kit) and blood pressure (tail pletismography).ConclusionsOur results suggest that endogenous testosterone might has proinflammatory effect contributing to the development of vascular alterations in hypertension. FAPESP,CNPq/PRONEX,CAPES
Enzymatic sources of basal hydrogen peroxide (H2O2) levels in rat arterial and venous tissues
Authors: Szasz Theodora , Sattler‐Leja Rebecca L , Watts Stephanie W 
Published: June 2021

Reactive oxygen species (ROS) production in vascular tissues is linked with the initiation and progression of diseases such as hypertension and atherosclerosis. An important but less studied sector of the vasculature is the venous system. We have shown that ROS production is greater in rat vena cava (VC) compared to aorta (Ao). Here we investigated the relative contribution of ROS enzymes to basal vascular H2O2 levels, hypothesizing that xanthine oxidase (XO) would be the most important H2O2 source in veins. Using two rat artery‐vein pairs: Ao‐VC and carotid artery (CA)‐jugular vein (JV), we examined H2O2 production in the presence of inhibitors for NADPH oxidase (100μM apocynin), XO (100μM allopurinol/oxypurinol), eNOS (100μM LNNA), mitochondrial complex I (10μM rotenone), and cyclooxygenase (COX, 10μM indomethacin/10mM ketorolac). Aortic H2O2 production was abolished by apocynin, allopurinol and indomethacin. Allopurinol also abolished H2O2 production in the CA and decreased it by 88% in the JV, but did not significantly lower VC H2O2 production. Surprisingly, COX inhibition with indomethacin decreased H2O2 levels of the JV by 82% and of the CA by 41%, while ketorolac decreased H2O2 production in the VC by 38%. LNNA and rotenone had no effect in any tissue. These findings highlight the importance of investigating non‐classical sources of ROS in vascular tissues.Funding: PO1 HL70687 (SWW), AHA 0715679Z (TS).
Pharmacologic response of regenerated bladders in a preclinical model
Authors: Bertram Tim , Christ George J , Andersson Karl‐Erik , Aboushwareb Tamer , Fuellhase Claudius , Soler Roberto , Wagner Belinda J , Jain Deepak , Ludlow John W , Payne Richard , Jayo Manuel J 
Published: June 2021

PurposeNeo‐bladder pharmacology was evaluated in animals after total cystectomy and implant of Autologous Neo‐Bladder Replacement constructs (NBR) made from bladder smooth muscle cells (SMC).MethodsNBR were seeded with SMC to form three test groups in which 25, 12, or 4x106 SMC were seeded per construct (n= 8/grp). A fourth group (n=8) in which radically cystectomized bladders were immediately reimplanted (R) served as a control. Ex‐vivo pharmacological and histological studies were conducted on neo‐bladder tissues at study termination.ResultsAt 9 mo post‐implantation, neo‐bladders of all groups had tissue histology (including mucosal and serosal linings, detrusor muscle, vasculature, and nerve components) consistent with native bladder. Contractile responses to parasympathomimetic (carbachol) and sympathomimetic (phenylephrine) agonists were similar among all groups. Logistic analysis of bladder tissue strips subjected to electrical field stimulation (EFS) revealed similar EC50 and slope factor values for all groups.ConclusionsAn Autologous Neo‐bladder Replacement construct is capable of regenerating a complete urinary bladder as a total organ with structural, urodynamic, and pharmacological features similar to native bladder. There was no evidence of abnormal tissue development, immune response, or systemic response to the neo‐bladder regeneration in any group.
The protective effect of tetrahydrobiopterin on rat hearts during long‐term hypothermic preservation
Authors: Zheng Ming‐zhi , ZHU Li , CHEN Ying‐ying , SHEN Yue‐liang 
Published: June 2021

ObjectiveTo assess the protective effect of tetrahydrobiopterin (BH4) on rat hearts suffered from long‐term hypothermic preservation.MethodsThe Langendorff model of isolated rat heart was used. Forty SD rat hearts were divided randomly into five groups (n=8): control group, hypothermic preservation groups (preserved in celsior solution for 6 or 12 h), BH4 groups (preserved in celsior solution containing 20 μmol/L of BH4 for 6 or 12 h). The myocardial contents of formazan, nitric monoxide (NO), and malonaldehyde (MDA) were measured. The myocardial ultrastructure was observed by transmission electron microscope.ResultsCompared with control group, hypothermic preservation of isolated hearts for 6 or 12 h could reduce the formazan and NO contents, and increase the MDA contents of myocardium. BH4 partly inhibited the hypothermic preservation‐induced decrease in formazan and NO contents, and enhancement of MDA content (P<0.05). After hypothermic preserved rat hearts for 6 or 12 h, the myocardial ultrastructure was impaired. Treatment with BH4 resulted in improvement in myocardial ultrastructure in hypothermic preserved hearts.ConclusionBH4 could reduce rat myocardial injury that induced by long‐term hypothermic preservation. The mechanism might be through the enhancement of myocardial NO production and inhibition of the generation of reactive oxygen species.
3,3′‐Diindolylmethane Enhances the Efficacy of Butyrate in Colon Cancer Prevention through Down‐regulation of Survivin
Authors: Bhatnagar Namrata , Li Xia , Chen Yue , Zhou Xudong , Garrett Scott H , Guo Bin 
Published: June 2021

Butyrate is an inhibitor of histone deacetylase (HDAC) and has been extensively evaluated as a chemoprevention agent for colon cancer. We recently demonstrated that mutations in the adenomatous polyposis coli (APC) gene confer resistance to HDAC inhibitor‐induced apoptosis in colon cancers (Huang and Guo, Cancer Research, 66(18), 9245‐9251, 2006). Here we show that APC mutation rendered colon cancer cells resistant to butyrate‐induced apoptosis due to the failure of butyrate to down‐regulate survivin in these cells. Another cancer preventive agent, 3,3′‐Diindolylmethane (DIM), was identified to be able to down‐regulate survivin in colon cancers expressing mutant APC. Pre‐treatment with DIM enhanced butyrate‐induced apoptosis. Down‐regulation of survivin by DIM occurred at both transcription and post‐translation level through increased protein degradation. We further demonstrated that DIM was able to down‐regulate survivin and enhance the effects of butyrate in apoptosis induction and prevention of familial adenomatous polyposis in APCmin/+ mice. Thus, the combination of DIM and butyrate is potentially an effective strategy for the prevention of colon cancer.This research was supported by Grants 1R03CA130062, 5R21CA111765 and 2P20RR015566 from the National Institutes of Health (NIH).
Estradiol (βE) Promotes Adhesion and Mitogenesis in CD34+ Human Progenitor Endothelial Cells (PECs)
Authors: Baruscotti Isabella , Barchiesi Fedreica , Jackson Edwin K. , Gillespie Delbert G. , Imthurn Bruno , Dubey Raghvendra K. 
Published: June 2021

Here we investigated whether βE promotes endothelium recovery by promoting PECs adhesion and proliferation. PECs were isolated from blood using CD34+‐antibody‐based magnetic separation and placed in culture or used for adhesion studies. For adhesion studies, early PECs, late differentiated PECs or mononuclear cells (MNC) labelled with fluorescent‐dye calcein were layered over monolayers of endothelial cells (ECs) pre‐treated with βE, and the number of adherent cells analyzed by ELISA. βE promoted adhesion of early PECs, but not late differentiated PECs or MNC, to ECs. Increased PECs colony formation and proliferation were observed in cultures of MNC isolated from IVF subjects where βE synthesis was induced. PECs expressed functional ERα and ERβ, and βE induced PECs growth (DNA/cell number) The mitogenic effects of âE were mimicked by PPT (ERα agonist), but not DPN (ERβ agonist), moreover these effects were blocked by ICI (ER antagonist) and MPP (ERα antagonist), βE treatment induced ERK1/2 phosphorylation and upregulated positive growth regulators including cyclin D1, A, B and E and downregulated the negative growth regulator p21. The effects of βE were mimicked by PPT but not DPN, moreover, ICI and MPP blocked the effects, suggesting the effects are ERα mediated.ConclusionβE selectively promotes the adhesion of early CD34+ PECs to ECs and promotes their proliferation via ERα mediated ERK1/2 activation.
Acute Antioxidant (AOX) Treatment Increases Muscle Microvascular O2 Extraction in Young Rats
Authors: Copp Steven W , Hirai Daniel M , Schwagerl Peter J , Herspring Kyle F , Musch Timothy I , Poole David C 
Published: June 2021

AOX treatment (76 mg/kg vitamin C, 52 mg/kg tempol) elevates microvascular O2 pressures (PO2mv) at rest and following the onset of muscle contractions in aged (A) rats reducing fractional O2 extraction (Herspring et al. J. Appl. Physiol. 2008).PURPOSETo test the hypothesis that this specific AOX treatment would elevate PO2mv in the spinotrapezius muscle of young (Y) rats at rest and during contractions.METHODSPO2mv, which reflects the dynamic balance between O2 delivery/utilization (fractional O2 extraction), was measured via phosphorescence quenching in the spinotrapezius of 12 Y (6‐8 mo) and 15 A (26‐30 mo) Fisher 344 x BN rats. Electrically‐induced contraction bouts (1 Hz twitch) were performed with and without (CON) intra‐arterial AOX administration. The PO2mv response was fitted with an exponential model and compared using two‐way ANOVA (age x condition).RESULTSThe CON baseline PO2mv was not different (P>0.05) between Y (31±4 mmHg) and A (30±3 mmHg). However, AOX decreased baseline PO2mv in Y (25±5 mmHg) whilst it was increased in A (36±3 mmHg) (both P<0.05). Moreover, throughout contractions in Y, AOX decreased PO2mv below CON values by 21+6% on average (P<0.05).CONCLUSIONSThe impact of AOX supplementation on PO2mv is age‐dependent. In contrast to A rats, in Y rats, AOX reduced PO2mv (increased fractional O2 extraction) at rest and during contractions.Support: AHA, Heartland Affiliate 0750090Z
Myostatin gene knockout increases vascular function in skeletal and cardiac muscle tissues
Authors: Ali Mohammed Irfan , Mintz James D , Elms Shawn , Hamrick Mark W , Stepp David W 
Published: June 2021

Exercise improves vascular health through mechanisms yet to be defined. Exercise enhances both muscle mass and metabolism, in part by decreasing myostatin (MS). Genetic MS deletion increases muscle mass and metabolism but vascular effects of these changes are unknown. This study tested the hypothesis that MS deletion would alter vascular function in the microcirculation. To test this hypothesis, we compared Ms−/− mice on an ICR background with Ms+/+ ICR as controls. Gracilis (SA), coronary (CA), gonadal (GA) and mesenteric (MA) resistance arteries were analyzed in vitro (±Ca2+, i.d. < 150μm). Acetylcholine (ACh) reactivity was used to assess endothelial relaxation. Similarity was seen between Ms−/− and Ms+/+ in mean arterial pressure (90±9 vs. 90±10 mmHg), heart rate (600±136 vs. 545±93 bpm) but in Ms−/− visceral adiposity and plasma leptin (2.4±0.3 vs. 0.6±0.1 ng/ml, p<0.01) were reduced. Maximum passive i.d. was similar in both strains in all arteries. In Ms−/−, dilation to ACh was increased in SA (88±1 vs. 71±4%, p<0.01) and CA (63±2 vs. 51±4%, p<0.01), unchanged in GA and reduced in MA (45±2 vs. 63±4%, p<0.01). Myogenic tone was reduced in CA and SA but unchanged in MA or GA. Taken together, these data indicate that increased muscle mass has pro‐dilatory effects on the microcirculation of muscular organs. These findings may explain, in part, improvements in vascular health seen with exercise training.HL76533
Differentiation of mechanical forces in perfused artery
Authors: Takahashi Maki , Mell Blair M , AbouAlaiwi Wissam A , Jones Thomas J , Ratnam Shobha , Kolb Robert J , Nauli Surya M 
Published: June 2021

BackgroundMechanical forces in the blood vessel can be biophysically observed in the forms of stretch due to distention of surrounding muscle and shear stress due to drag force generated by the blood flow. We report here a novel approach to distinguish these two forces.Methods and ResultsAorta of an adult mouse is isolated and cleaned from connective tissues. The aorta, which is to be perfused, is then submerged freely in phosphate buffer saline solution or placed inside a capillary tubing. The aorta inside the capillary tube has very limited room for stretching or expanding by the perfusate pressure. Our data shows that the changes in cytosolic calcium are much more prolonged in freely‐placed than in capillary‐enclosed aortas. The perfuse‐induced calcium signal can be inhibited by apyrase more substantially in freely‐placed than in capillary‐enclosed aortas.ConclusionDifferent forms of mechanical forces may be physiologically impossible to differentiate in vivo because of the complex nature of the vascular system and its surrounding tissue. Here, we are introducing a new setup that allows us to distinguish the mechanical force of stretching and shear stress in an ex vivo study.
Proteinuria is associated with increased systemic and glomerular water permeability
Authors: Ferguson Joanne K , Neal Chris R , Bates David O , Harper Steven J , Salmon Andrew H J 
Published: June 2021

Proteinuria is associated with an increased risk of cardiovascular death. Evidence suggests that proteinuria reflects systemic endothelial dysfunction as well as renal pathology. The Munich Wistar Fromter (MWF) rat strain develops spontaneous proteinuria, permitting study of altered endothelial function under conditions of increased proteinuria. Male MWF rats (15‐24 wks) were significantly proteinuric (MWF:15.0±1.5 n=14 Wistar: 1.8±0.20 n=10, p<0.0001). Hydraulic conductivity (Lp) and effective oncotic pressure (σδπ) were measured in individually perfused microvessels of the mesentery. Male MWF rats had significantly increased Lp (x10−7 cm s−1 cmH20−1) but unchanged σδπ (cmH20) compared with age matched wistar controls (Lp MWF:6.4±1.8 n=7; Wistar: 2.8±0.4 n=15, p<0.05 σδπ MWF:24.6±2.0 n=7; Wistar:23.7±0.9 n=7). Normalised glomerular ultrafiltration coefficient (LpA/Vi) was measured using an oncometric assay. The increase in systemic Lp was mirrored by a significant increase in glomerular LpA/Vi (MWF: 1.5±0.1 min−1mmHg−1 n=58; Wistar: 1.0±0.1 min−1mmHg−1 n=24, p<0.01). These results suggest proteinuria is associated with increased glomerular and systemic water permeability. The mechanistic links require further investigation and may provide insight into the predictive link between proteinuria and increased cardiovascular mortality.Supported by BHF
Disruption of Intermediate‐conductance Calcium‐activated Potassium Channels, KCa3.1, Unchanges NO‐dependent Relaxations in Mouse Aortas
Authors: Ohta Masanori , Miura Hiroto 
Published: June 2021

Endothelial NO release and vasorelaxation are preceded by KCa channel activation causing hyperpolarization, facilitated influx of extracellular calcium and NO synthesis in endothelial cells. The aim of this study was to investigate the precise role of KCa3.1 in vascular responses in mouse aortas.MethodsWire myography was performed using KCa3.1+/+ (WT) and −/− (KO) mouse aortic rings precontracted with phenylephrine.ResultsRelaxation to acetylcholine (10−10 to 10−4 M) was identical between strains (%max relaxation: KO 78±5 p=ns vs WT 87±5% and EC50; KO 4.4±1.4 p=ns vs WT 5.0±2.0 x 10−8 M, n=5‐6) and was abolished by endothelial denudation. Nω‐nitro‐L‐arginine methyl ester significantly reduced the relaxation in both to a similar extent (WT 34±9 and KO 36±9%, p<0.05 vs control, respectively, n=7‐8), while indomethacin had no effect. No further reduction in relaxations was seen with the combination of inhibitors. Relaxation to sodium nitroprusside (10−12 to 10−4 M) was also unaltered in KO compared to WT (%max relaxation: KO 90±4 p=ns vs WT 83±8% and EC50; KO 2.9±1.5 p=ns vs WT 21.3±13.6 x 10−8 M, n=5‐6).ConclusionKCa3.1 alone plays no discernible role in mediating NO‐dependent vasorelaxation in mice, supporting a role for small‐conductance KCa channel either alone or in combination with KCa3.1. Supported by an NIH grant.
Effects of age on training‐induced adaptations of the neuromuscular junction
Authors: Roby Mackenzie Anne , Glass Emily , Deschenes Michael 
Published: June 2021

Unlike skeletal muscle, the effect of aging on training induced adaptations of the neuromuscular junction (NMJ) has received scant attention. This study aimed to determine whether this important synapse exhibits age‐specific adaptations to endurance training. Twenty young adult (8 mo) and 20 aged (24 mo) male Fischer 344 rats were assigned to either exercise trained or sedentary control groups (4 groups, N=10/group). All trained rats participated in the same 10 week program of treadmill running (5days/wk). Following the 10 week intervention, all rats were euthanized and soleus muscles were removed and quickly frozen at resting length. Muscles were sectioned and stained with cytofluorescent procedures to visualize pre‐synaptic nerve terminal branches, and post‐synaptic acetylcholine receptors. Pre‐ and post‐synaptic images were collected with confocal microscopy and used to quantify various parameters of NMJ morphology. Results showed that young, but not aged rats demonstrated significant (P<0.05) training‐induced increases in pre‐synaptic nerve terminal branch number, total branch length, and branching complexity. Similarly, only the NMJs of young rats displayed significant training‐induced increments in perimeter length around endplate regions, and expanded areas occupied by acetylcholine receptors. Our data show that aging blunts the ability of the NMJ to adapt to endurance exercise training.Supported by the National Institute on Aging, and The Foundation for Aging Studies and Exercise Science Research.