bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of a calcineurin inhibitor on Lipopolysaccharide‐induced loss of vascular tone and blood pressure decrease in conscious mice
Authors: Staehr Mette , Khatam‐Lashgari Apameh , Hansen Pernille B , Jensen Boye L 
Published: June 2021

The immunosuppressive drug cyclosporin A (CsA) inhibits the production of nitric oxide (NO) through inhibition of the NO synthases. Especially iNOS is involved in the synthesis of large amounts of NO seen in sepsis, which leads to hypotension and multiple organ dysfunction. We hypothesized that CsA counteracts the LPS‐induced blood pressure decrease and reduced vasoreactivity in isolated murine aorta rings in a model of septic shock.To test this, blood pressure and heart rate was measured in conscious mice with indwelling catheters given a bolus (20 or 40 mg/kg) of CsA followed by continuous infusion (20 or 40 mg/kg/day) for one day before an LPS bolus was given (2 mg/kg). In vitro, studies were performed with aortic rings incubated with LPS (50 μg/ml) w/wo CsA, with CsA alone or vehicle.CsA (20 and 40 mg/kg) induced a significant increase in blood pressure (≈11 mmHg), with no effect on heart rate. After an LPS bolus, blood pressure and heart rate decreased, but there was no difference in delta blood pressure and heart rate compared to LPS alone. iNOS mRNA and protein expression was significantly reduced by CsA as well as plasma NOx excretion. CsA significantly attenuated the LPS‐induced decrease in vasoreactivity. It is concluded that CsA improve vasoreactivity in vitro while in a murine model of septic shock in vivo, CsA at 20 and 40 mg/kg did not counteract the effect of LPS on blood pressure.
Aortic stiffening as a result of reduced elastin content leads to cerebral artery dysfunction
Authors: Walker Ashley E , Henson Grant D , Reihl Kelly D , Bramwell Colton , Li Dean Y , Lesniewski Lisa A , Donato Anthony J 
Published: June 2021

With advancing age, large artery stiffening is linked to reduced elastin content and is thought to result in resistance artery dysfunction, but this has not been empirically tested. To isolate the effects of large artery stiffness without other age‐related changes, we compared elastin haploinsufficient (ELN+/−) and wildtype (ELN+/+) mice (4–6 mo, n=4–10/group). ELN+/− had greater aortic stiffness (pulse wave velocity, 406±45 vs 306±29 cm/s, p=0.04) and blood pressure (p<0.05) compared with ELN+/+. In the middle cerebral artery (MCA), endothelium‐dependent dilation (EDD) to acetylcholine was impaired in ELN+/− vs ELN+/+ (max: 37±6 vs 54±4%, p=0.03). L‐NAME pretreatment abolished group differences in MCA EDD (p=0.54), indicating less nitric oxide mediated dilation in ELN+/−. MCA vasoconstrictor responses were greater in ELN+/− vs ELN+/+ for angiotensin II (−53±4 vs −20±6%, p=0.002) and norepinephrine (−62±3 vs −41±2%, p=0.002). In contrast, EDD and vasoconstrictor responses were similar between groups in gastrocnemius feed arteries (P>;0.05). Endothelium‐independent dilation was similar for groups in each artery (P>;0.05). In conclusion, aortic stiffness as a result of reduced elastin leads to impaired dilator and increased constrictor responses in small cerebral, but not skeletal muscle, arteries. Thus, large artery stiffening likely contributes to cerebral artery dysfunction with aging.Supported by AG029337, AG040297, AG033196, HL007576
LECTINIC BINDING OF CANDIDA GLABRATA TO OLIGOSACCHARIDES ON THE CORONARY LUMINAL MEMBRANE ALTERS FLOW‐INDUCED CARDIAC RESPONSES.
Authors: Torres‐Tirado David , Ramirez‐Zavaleta Candy , De Las Peñas Alejandro , Castaño Irene , Rubio Rafael 
Published: June 2021

Candida Glabrata (CG) is a yeast that may invade humans blood stream causing dead. CG surface is lectinic and binds with high affinity to oligosaccharides (O) present in cell membranes, as example, coronary endothelial luminal membrane (CELM).Conversely, coronary flow (CF) stimulates auricular‐ventricular transmission (A‐Vt). CF acts on CELM lectins (L) and O, causing a reversible L‐O complexing necessary for CF stimulation of A‐Vt. We hypothesized that CG upon binding to CELM's O prevents CF‐induced L‐O complexing; as a result inhibiting CF‐stimulation of A‐Vt.In Langendorff perfused isolated guinea pig hearts A‐Vt was determined at different CF. As CF (ml/min) increase A‐Vt (msec) decrease. (control curve). Thereafter, to study the effects of CG bound to the CELM, CG (CGM35 sir3Δ, 3.7×103 cells/ml), was intracoronary given for 5 min and wash at length for 5 min and an experimental CF‐A‐Vt curve determined. The experimental curve was on top of the control curve i. e. CG upon binding to CELM increases the A‐Vt value at any CF. To test the effect was due to CG bound to L, CG was displaced by perfusing sugars components of O; mannose or Galactose. Perfusion of any of these sugars after CG they reverted its inhibitory effects on CF‐induced A‐Vt stimulation. Furthermore, simultaneous perfusion of CG and any of these sugars prevented the CG‐inhibitory effects, likely competing with CELM's O for CG binding. Thus, CG upon binding to CELM's O competes with L preventing CF‐induced L‐O complexing; as a result inhibits CF‐stimulation of A‐Vt. In other experiments using CG like affinity beads and mixing with CELM proteins, we found that CG bind to angiotensin type 1 receptor, alpha 1 adrenergic receptor, endothelin receptor and vascular cell adhesion protein 1, by western blot. This mean that CG could be altered the response of its receptors by the only interaction L‐O.
The COP9 signalosome subunit 8 (CSN8) hypomorphism impairs deneddylation and exacerbates desmin‐related cardiomyopathy (DRC)
Authors: Su Huabo , Li Jie , Wei Ning , Wang Xuejun 
Published: June 2021

BackgroundInadequate protein quality control (PQC) contributes to the development of cardiac diseases. We previously identified the COP9 signalosome (CSN), a deneddylase that removes ubiquitin‐like protein Nedd8 from target proteins, is essential to proteasomal and autophagic proteolysis in the heart. The present study determines the impact of CSN8 hypomorphism (CSN8hypo) on the removal of misfolded proteins in mouse hearts.Methods and resultsCSN8hypo accumulated the neddylated forms of cullins and non‐cullin proteins in mouse hearts. Using a proteasome functional reporter mouse, we found the proteasomal function was compromised in CSN8hypo mouse hearts. When crossed with transgenic mice overexpressing CryABR120G, a bona fide misfolded protein, CSN8hypo reduced ubiquitinated proteins but increased protein aggregates in the heart, which eventually aggravated the CryABR120G‐induced cardiomyopathy and shortened the lifespan of the mice. In cultured cardiomyocytes, CSN8 knockdown suppressed the ubiquitination and degradation of CryABR120G, leading to accumulation of protein aggregates and exacerbation of CryABR120G‐mediated proteotoxicity.ConclusionThe CSN is required for the ubiquitination and clearance of misfolded proteins in cardiomyocytes, and therefore is critical to cardiac PQC. (Funding agencies: NIH and AHA)
Molecular Basis for Anabolic Resistance in Disuse Atrophy of Skeletal Muscle
Authors: Kelleher Andrew Ryan , Kimball Scot R , Dennis Michael D , Schilder Rudolf J , Jefferson Leonard S 
Published: June 2021

The present study employed a rat handlimb immobilization model of disuse atrophy to assess responses of mTORC1 signaling and protein synthesis, both in the basal state and after a nutrient stimulus. In the basal state, mTORC1 signaling and protein synthesis were repressed within 24h in the soleus of an immobilized compared to a non‐immobilized hindlimb. These responses were accompanied by a concomitant induction in expression of the mTORC1 repressors REDD1/2. The nutrient stimulus produced an elevation of similar magnitude in mTORC1 signaling in both the immobilized and non‐immobilized muscle. In contrast, phosphorylation of S6K1 on T229 and T389 in response to the nutrient stimulus was severely blunted. This result indicated an immobilization‐induced defect in PDK1 activity, which is required for phosphorylation of T229 as a prerequisite for phosphorylation of T389 by mTORC1. In conclusion, the results show an immobilization‐induced attenuation of mTORC1 signaling mediated by REDD1/2 that is nonetheless responsive to a nutrient stimulus. More importantly, they suggest that phosphorylation of S6K1 on T389, which is required for full activation of the kinase, fails to respond appropriately to the stimulus. This lack of response is apparently due to a defect in PDK1 activity and would explain the phenomenon of “anabolic resistance” referred to in other models of disuse atrophy.Supported by NIH grant DK‐15658.
Adrenergic agonists do not modify in vivo cholinergic eccrine sweating dose‐response relations
Authors: Wilson Thad E. , Jurovcik Andrew J. , Mann Sarah , Metzler‐Wilson Kristen , Simpson Chris 
Published: June 2021

Muscarinic and α‐ and β‐adrenergic receptors have been identified on secretory clear cells of human eccrine sweat glands. Potential interactions of these receptor populations in an intact in vivo model are unclear. To probe for subadditive, additive, or synergistic multiple agonist relations, 15 healthy subjects had 6 intradermal microdialysis probes placed in dorsal forearm skin perfused with: 1 & 2) 6 log M doses of acetylcholine (ACh); 3 & 4) ACh doses plus 200 or 80 μM isoproterenol; 5) ACh doses plus 3.16 μM norepinephrine and 1 mM propranolol; 6) ACh doses plus 100 μM phenylephrine. Sweat rate was measured via capacitance hygrometry and dose causing ½ maximal response (ED50) was identified by logistic modeling. ACh alone produced dose‐response relations with ED50 of −1.2±0.2. The addition of a β‐adrenergic agonist did not significantly alter the ED50 (200 μM = −1.3±0.1 and 80 μM = −1.1±0.3). Neither the addition of an α1‐adrenergic agonist nor α1‐ and α2‐adrenergic agonists co‐perfused with a β‐adrenergic antagonist significantly affected ED50 (−1.2±0.1 and −1.4±0.1, respectively). Combined, these data indicate that functional doses of adrenergic agonists do not modify the in vivo cholinergic eccrine sweating dose‐response relations. These results do not provide evidence for multiple agonist combinations causing augmented sweating responses in vivo.Funding: Osteopathic Heritage Foundation
Changes in Body Composition and Aerobic Capacity after High Altitude Exposure in Elite Climbers
Authors: Carlson Alex Robert , Kasak Alexander , Issa Amine , Taylor Bryan , Summerfield Douglas , Miller Andrew , Fuglestad Andrew , Johnson Bruce 
Published: June 2021

BACKGROUNDHigh altitude (HA) exposure influences appetite, protein synthesis and breakdown, and aerobic capacity. Thus, HA exposure typically causes weight (wt) loss, while the impact on aerobic capacity upon return to sea level is more variable.OBJECTIVETo examine the influence of hypobaric hypoxia on body composition and exercise capacity in elite HA climbers (n=4, 2 female) acclimating at ≥5,150 m over 2 mo. relative to trekkers (n=8, 0 female) acclimating at 5,150 m over 2 wks (Mt. Everest, Nepal). Each elite climber successfully summited Mt. Everest.METHODSBody composition (DEXA, skin folds, wt) and exercise capacity (treadmill) were assessed before and within 2 wks post HA.RESULTSHA exposure increased Hct and Hb, with peak values of 52±5% and 18±2 g/dl, and 50±3% and 17±1 g/dl for the climbers and trekkers, respectively. HA decreased lean and fat tissue in both the climbers (lean −4.4±2.3%, fat −8.2±4.0%) and trekkers (lean −1.8±1.6%, fat −5.8±6.1%) (all P≤0.06). No change was observed in skin folds for either group. Wt decreased in the climbers (−5±2%, P<0.03) and trekkers (−3±1%, P<0.01). There was no change in VO2max pre‐to post‐HA in either group (climbers 3.26 ± 0.37 vs. 3.27 ± 0.61 L/min; trekkers 3.60 ± 0.54 vs. 3.66 ± 0.43 L/min).CONCLUSIONHA results in both lean and fat tissue loss in well acclimatized climbers and trekkers with little subsequent impact on aerobic capacity. Mayo Clinic & TNF.
Renal mechanisms driving K excretion after a K containing meal
Authors: Rengarajan Srinivas , Youn Jang H , Lee Donna H. , McDonough Alicia A 
Published: June 2021

We aimed to determine the molecular mechanisms leading to renal K excretion after an acute meal induced K load by studying ion transporter regulation.MethodMale Sprague Dawley rats (n=8) were fasted overnight with free access to water and then fed a meal with no K+ (0K) or 2% K+ (2K) for 3 hours in metabolic cages. Urine was collected and after anesthesia (ketamine‐xylazine), blood was sampled, kidneys removed and cortex and medulla homogenates were prepared. Transporter abundance and phosphorylation were assessed by quantitative immunoblots with specific antibodies.ResultsA single K rich meal increased plasma [K+] within the normal range in the 2K versus 0K group: 5.18±0.16mEq versus 4.01±0.12mEq (p<0.01), and sharply increased urine K+ in the 2K versus 0K group: 713±48 versus 55±15μmol (p<0.01). Urine volume tended to increase in the 2K versus 0K group: 3.63±0.16 versus 1.97±0.54ml/3 hr, but urine Na was unchanged. Cortical NCC, NCC‐P and SPAK‐P abundance were decreased by 24±4% (p<0.01), 63±4% (p<0.01) and 38±5% (p<0.01) respectively in 2K versus 0K rats. NHE3, ENaC and ROMK were unchanged by 2K diet feeding.We postulate that the kaliuresis can be explained by a decrease in distal convoluted tubule (DCT) Na which would drive more Na to the cortical collecting duct (CCD) where Na reabsorption drives K secretion, analogous to the effect of an NCC inhibitor. Research support: NIH DK083785
Rotten eggs’ H2S acting on human airway smooth muscle mechanics
Authors: Fitzgerald Robert , Lee Danielle Y , Panettieri Reynold A , Wang Rui , An Steven S 
Published: June 2021

The well‐known and reported mechanisms of action of small molecular gases on the vasculature point to a possible therapeutic agent for patients suffering from hypertension and/or stroke. Hydrogen sulphide (H2S) is a new gas in this class. H2S relaxes vascular smooth muscle via the KATP channel in several species. Trachealis of dog and rat express ATP‐sensitive potassium channels. Here, we explored the impact of two agents capable of generating H2S (Na2S and GYY4137) on human airway smooth muscle (ASM). ASM cells were prepared from human bronchi obtained from lungs unsuitable for transplantation, and dynamic changes in stiffness were measured as an indicator of contraction and relaxation of isolated human ASM cells, using Magnetic Twisting Cytometry (MTC). Acute exposure to both Na2S and GYY4137 decreased cell stiffness in a dose‐dependent fashion, with maximal relaxation at 10mM and 5mM, respectively. In addition, cells exposed to varying doses of GYY4137 for 24 hours exhibited dose‐dependent decreases in cell stiffness that were substantially greater than acute responses (21% relaxation at 300s vs. 50% relaxation at 24h). These findings demonstrate that smooth muscle in the airway react quite similarly to that in the vasculature to H2S and suggest, thereby, this class of small gas molecules can be exploited for treating constricted human airways. We are currently validating the effects of H2S on human lung slices, as well as exploring for the presence of H2S synthesizing enzymes (cystathionine β‐synthase and cystathionine γ‐lyase) in human ASM and their mechanistic role using animal models.NIH Funding: HL107361, HL 050712–13
Klotho Regulation of TRPC Channels Involving Human Breast Cancer Cell Migration
Authors: Kong In Deok , Kim Ji‐Hee , Hwang Kyuhee , Jeong Yangsik , Cha Seung‐Kuy 
Published: June 2021

Klotho is a mammalian aging‐suppression gene and function as a suppressor of cancer. Here, we investigated the molecular mechanism of Klotho regulation of TRPC channels involving human breast cancer cell migration. Serum‐induced activation of TRPC and cell migration was specifically blocked by TRPC channel inhibitor, SKF96365, but not by voltage‐gated Ca2+ channel inhibitor, nimodipine. Treatment of purified Klotho protein inhibited TRPC6 channel activity. Interestingly, serum treatment increased the surface expression of TRPC6 channel. Klotho suppressed cell surface abundance of TRPC6 channels, whereas did not affect gating and activation kinetics of the channel. In addition, treatment of PI3K inhibitor (Wortmannin) or Erk1/2 inhibitor (U0126) blocked the serum‐induced augmentation of TRPC6. Suppression of vesicular trafficking by treatment of brefeldin A or tetanus toxin significantly decreased TRPC6 activity and Klotho regulation.Taken together, our data suggest that Klotho decreases surface expression of TRPC6 probably by reducing serum growth factor‐induced secretory pathway of the channel. Klotho may function as suppressor for human breast cancer cell migration caused by upregulation of TRPC6.[This research was supported by Basic Science Research Program through the National Research Foundation of Korea funded by the Ministry of Education, Science and Technology (2010–0024789)]
DHA‐enriched fish oil modulates B cell function and modifies clustering of lipid microdomains
Authors: Gurzell Eric Anthony , Teague Heather , Harris Mitchel , Clinthorne Jonathan , Shaikh Saame Raza , Fenton Jenifer 
Published: June 2021

Fish oil has significant immunomodulatory effects and is primarily associated with suppression of T lymphocyte and dendritic cell function. The purpose of this study was to investigate the changes that DHA‐enriched fish oil (DFO) feeding elicits on B cells, an understudied, yet important cell population with respect to inflammatory pathologies. Utilizing confocal microscopy and flow cytometric analyses of purified splenic B cells, we assessed the effects of DFO on B cell activation in 129Sv mice (n=10/treatment). DFO feeding altered the lipid composition of splenic B cells and diminished GM1 microdomain clustering in the membrane. The clusters on B cells from mice fed the DFO diet appear 0.275 μm larger compared to control fed mice. In vivo, DFO increased lymphoid tissue B cell populations and surface markers of activation compared to controls. Ex vivo, LPS‐stimulated B cells isolated from DFO fed mice expressed more CD40 and produced more IL‐6 (50% increase) and TNF‐α (40% increase) than those from control mice, however OVA‐FITC antigen uptake was similar. DFO fed mice had significantly higher plasma IL‐5, IL‐13, and IL‐9 (Th2‐biasing cytokines) and cecal IgA compared to control. These results support the hypothesis and an emerging concept that fish oil enhances B cell function in vivo. These data are consistent with observations in C57Bl/6 mice, suggesting dietary fish oil enhances humoral immunity.Grant Funding Source: NIH R03CA162427 (to J.I.F.) and NIH R15AT006122 (to S.R.S.)
Relationship Between In Vitro Absorption of Chondroitin Sulfate (CS) and Its Molecular Weight
Authors: Surapaneni Lahari , Haley‐Zitlin Vivian , Bodine Ashby , Jiang Xiuping , Brooks James 
Published: June 2021

ObjectiveThe purpose of this study was to investigate if the molecular weight of chondroitin sulfate (CS) has an impact on its absorption in vitro, in a Caco‐2 cell model.MethodsCaco‐2 cells in 24 well plates were incubated for 2 hours with eight CS samples of differing molecular weights (7 kDa – 35 kDa). The amount of CS transported into the basolateral side of the Caco‐2 monolayer was quantitatively determined to calculate the permeability coefficients (Papp).ResultsOf the 8 samples evaluated, four samples had a Papp value of 15 × 10−6 cm sec−1 or higher indicating moderate to high absorption. Two of the four samples with higher Papp values were high molecular weight compounds (~ 35 kDa).ConclusionWithin the molecular weight range used in this experiment, the absorption of CS samples did not have a correlation with their molecular weights but, interestingly, correlation was observed between the absorption and percentage of 6‐sulfated disaccharide in the CS samples.Grant Funding Source: Pharmavite, Inc.
Liquid and solid sources of added sugar and their associations with body weight and metabolic syndrome components in children
Authors: Wang Jiawei , Light Kelly , Johnson‐Down Louise , St‐Arnaud‐McKenzie Danielle , O'Loughlin Jennifer , Paradis Gilles , Gray‐donald Katherine 
Published: June 2021

Limited evidence exists in children relating added sugar (ASug) from solid‐food sources with obesity and metabolic syndrome (MetSyn) in contrast to considerable data on sugar‐sweetened beverages (SSB). Our aim was to examine dietary sources of ASug and their relationship with body weight indicators and MetSyn components. Exposure data were three 24‐hour dietary recalls from 613 Caucasian children (8–10 y) in the QUebec Adiposity and Lifestyle InvesTigation in Youth (QUALITY) study (2008–2010). Outcome measurements included body mass index (BMI), waist circumference (WC), waist‐to‐height ratio (WHR), triglyceride, HDL‐C, systolic blood pressure (SBP) and HOMA‐IR. Multivariate regressions were used with covariates of age, sex, fat mass index (fat mass by dual‐energy absorptiometry) and physical activity (7‐day accelerometer). On average, 12% of energy intake (204 kcal) came from ASug. Four top sources of ASug were sweets (contributed 28% of ASug), baked products (25.9%), SSB (17.1%) and ready‐to‐eat cereal (5.6%). No associations were found with overweight or metabolic indicators with solid‐food sources of ASug. This was in contrast to the association of ASug from SSB with BMI, WC, WHR and SBP. Although children consumed more ASug from sweets and baked products than from SSB, these solid sources of ASug were not associated with health indicators.Grant Funding Source: Canadian Institutes of Health Research, Heart and Stroke Foundation of Canada and Fonds de la recherche en sante du Quebec.
Salmonella Typhimurium Directs the Localization of the Desmosomal Protein, PERP, to Induce Inflammation
Authors: Hallstrom Kelly , Casanova James E , McCormick Beth A 
Published: June 2021

Salmonella enterica serovar Typhimurium is one of many Salmonella strains responsible for over 40,000 cases of Salmonella‐induced gastroenteritis in the U.S. yearly. Salmonella invade the apical surface of intestinal epithelial cells and trigger inflammation primarily through the activity of the type three secreted effector, SipA, which activates signal transduction cascades that ultimately lead to the recruitment of neutrophils (PMN) to the site of invasion. Previous studies showed that SipA acts extracellularly at the apical surface suggesting it interacts with an apically‐located host protein. Recently, we identified the desmosomal protein, PERP, as a SipA‐binding partner. PERP accumulates at the apical surface in response to Salmonella in a SipA‐dependent manner and is a key regulator of transepithelial PMN migration during Salmonella infection. In examining the mechanism by which this occurs, we noted that pharmacologic inhibition of the endocytic pathway by the drug dynasore blocks PERP re‐internalization. Sucrose gradient results also showed that during Salmonella infection PERP is enriched in the apical membrane and the endosomal fractions, suggesting that PERP is trafficked to the apical surface using the endosome recycling system. We propose that S. Typhimurium interferes with the homeostatic re‐uptake of PERP, which is governed by the endosome recycling pathway, via the activity of SipA.Funding Sources: NIH, NIDDK, Crohn's and Colitis Foundation of America