bluuebunny/crossref_metadata_2025_split huggingface dataset:
A direct effect of erythropoietin on hepcidin expression involving EPOR signaling
Authors: Pinto Jorge P , Ribeiro Sara , Pontes Helena , Thowfeequ Shifaan , Tosh David , Carvalho Félix , Porto Graça 
Published: June 2021

Background/Aims: Hepcidin is the main iron regulatory hormone, controlling the systemic absorption and remobilization of iron from stores. In vivo studies showed that hepcidin is down‐regulated by erythropoiesis, anemia and hypoxia, which conforms to the need for iron input for erythrocyte production. The hormone erythropoietin (EPO) is the primary signal triggering erythropoiesis in anemia and hypoxia. Therefore, a direct involvement of erythropoietin in hepcidin regulation can be hypothesized. The aim of this study was to test the effect of EPO on hepcidin expression in vitro and to begin characterization of the mechanisms involved.Methods: Fresh mouse hepatocytes and the HepG2 cell line were supplemented with physiological and supra‐physiological doses of EPO. Blocking of EPOR was performed with a specific antibody. Quantification of hepcidin and C/EBPA mRNA was performed by quantitative Real‐Time PCR. C/EBPA protein levels were quantified by Western blot hybridization.Results: EPO regulates hepcidin expression in HepG2 cells and in mouse hepatocytes, in a dose‐dependent manner. This effect is mediated through EPOR signaling, since hepcidin expression is restored by EPOR‐blocking. A pattern of expression similar to hepcidin after EPO and α‐EPOR treatments was observed for CEBPA at mRNA and protein levels, suggesting the involvement of this transcription factor in the regulation of hepcidin by EPO.
Antenatal glucocorticoid at clinically relevant doses alter glucose tolerance in the adult offspring in sheep
Authors: Figueroa Jorge P. , Massmann Angela G , Zhang Jie , Rose James C 
Published: June 2021

Exposure to glucocorticoids (GC) in the perinatal period is associated with alterations in glucose tolerance and hypertension in adult life. The aim of the present study was to study the effects of clinically relevant doses of GC on glucose tolerance and adipose tissue leptin expression.Pregnant sheep were treated with two IM doses of betamethasone (BM, 0.17 mg/kg) or vehicle 24‐hours apart at 80 days gestational age (term 145) and allowed to deliver at term. Adult offspring (12–18 months of age) of both sexes were chronically instrumented under general anesthesia to place intravascular catheters. Insulin sensitivity was evaluated both by iv glucose tolerance test (IVGTT) and euglycemic clamp (HEC) techniques. Leptin mRNA expression was determined by RPA in perirenal, omental and subcutaneous fat. Data Mean±SEM were analyzed by two way ANOVA and/or t test.A significant time and treatment (BM) effect was observed in plasma glucose during the IVGTT. BM also was associated with higher insulin plasma levels, but did not reach statistical significance. Leptin expression was significantly higher in perirenal but not omental adipose tissue of BM exposed sheep [0.28±0.1 vs 0.88±0.2;0.60±0.2 vs 1.0±0.2]. Exposure to a single course of GC at 0.55 gestation has longterm effects on glucose metabolism regulation. BM‐exposed sheep exhibit alterations in glucose tolerance, hyperinsulinemia and insulin resistance. HL 68728.
Aseptic externalized catheter placement and patency in cage confined and exercising yucatan miniature swine
Authors: Fleenor Bradley Stephen , Ivey Jan , Bowles Douglas K. 
Published: June 2021

Chronic venous catheters in swine often malfunction and can lead to infection. Because of the similarities in human coronary anatomy the use of swine in biomedical research is an excellent model for studying cardiovascular disease. Here we describe the aseptic placement of externalized jugular catheters in 14 Yucatan miniature swine which remained patent (86%) and infection free (93%) for 28 days. Furthermore, 8 of the 14 swine underwent ∼ 90 minutes of treadmill exercise 20 of 28 days whereas the remaining 6 were cage confined. Following a small paratrachel incision, a custom designed trocar was used to subcutaneously tunnel a tygon catheter from the ventral to the midline of the dorsal neck. The proximal catheter was inserted into the jugular vein and secured 2 mm cranial to the heart within the vena cava. The distal catheter was exposed dorsally (1.5 cm) with a 17F stub adaptor and injection cap which allowed for drug injections as well as catheter flushing (3 times a week) and lock (1ml of 1000u/ml heparin). One animal that did develop an infection presented with signs late but still had a functional catheter. Our results demonstrate that external catheters can be highly functional and infection free in sedentary and exercised swine.*Authors contributed equallySupported by: NIH HL 52490
O‐GlcNAcylation increases vascular reactivity in rat aorta
Authors: Lima Victor Vitorino , Giachini Fernanda R. C. , Carneiro Fernando Silva , Webb R. Clinton , Tostes Rita C. 
Published: June 2021

Introduction: O‐Linked N‐acetylglucosaminylation (O‐GlcNAcylation) plays an important role in many aspects of protein function. Whereas elevated O‐GlcNAc levels contribute to diabetes related end‐organ damage, O‐GlcNAcylation is also physiologically important.Aim: Because proteins that play a role in vascular tone regulation can be O‐GlcNAcylated, we hypothesized that O‐GlcNAcylation increases vascular reactivity to contractile stimuli.Methods: Aortas from Sprague‐Dawley male rats were incubated for 24 h with vehicle, PugNAc (O‐GlcNAcase inhibitor, 100μM), azaserine (GFAT inhibitor, 20μM), high glucose (25mM) or manitol (25mM).Results: PugNAc incubation, but not azaserine, manitol or high glucose, significantly increased O‐GlcNAc‐proteins (Fig A), as determined by Western blot. PugNAc also increased phenylephrine and KCl contractions, which was not observed in the presence of L‐NAME. PugNAc decreased acetylcholine (Fig B), but not sodium nitroprusside, relaxation. Incubation with azaserine, high glucose or manitol did not change vascular reactivity. PugNAc incubation augmented e‐NOS levels, but decreased e‐NOS1177 phosphorylation.Conclusions: Vascular O‐GlcNAcylation modulates vascular reactivity, possibly due to its effects on e‐NOS expression and activity, reinforcing the idea that O‐GlcNAcylation is important in physiological conditions.Support: NIH / CAPES
Enhanced expression of pluripotency gene Oct‐4 in pulmonary artery smooth muscle cells from patients with idiopathic pulmonary arterial hypertension
Authors: Yao Weijuan , Firth Amy L. , Ogawa Aiko , Yuan Jason X.‐J. 
Published: June 2021

Pulmonary vascular remodeling is a major cause for the elevated pulmonary vascular resistance in patients with idiopathic pulmonary arterial hypertension (IPAH). This study aimed at testing the hypothesis that the vascular medial hypertrophy may partially result from the de‐differentiation of pulmonary artery smooth muscle cells (PASMCs). RT‐PCR was performed to determine transcripts of pluripotency genes (Oct‐4/Nanog) and progenitor cell markers (CD34/Flk‐1) in PASMCs from normal subjects (n=3) and IPAH patients (n=3). The mRNA level of Oct‐4 in IPAH PASMCs was significantly higher than in normal PASMC, whereas Nanog was not detectable in IPAH and normal cells. The mRNA level of CD34/Flk‐1 was very low and no difference was found between IPAH and normal cells. Oct‐4 is a transcription factor highly expressed in undifferentiated cells (e.g., embryonic stem cells and multipotent adult progenitor cells). The upregulation of Oct‐4 indicates that PASMCs from IPAH patients are in the de‐differentiated state, and the transition from a differentiated (contractile and synthetic) phenotype to a de‐differentiated (proliferative) phenotype may serve as an important cause for vascular medial hypertrophy in IPAH.Founding source: NIH grants (HL064945, HL054043, HL066012)
Tempol treatment ameliorates pulmonary hypertension in the TG (mREN2) 27 rat
Authors: DeMarco Vincent Gerard , Habibi Javad , Whaley‐Connell Adam T. , Andresen Bradley T. , Bosanquet James Percival , Delcour Kimberly S. , Schneider Rebecca Irene , Hayden Melvin R. , Sowers James R. , Dellsperger Kevin C. 
Published: June 2021

Background: We recently reported that Ren‐2 rats, which express the mouse renin gene in extra‐renal tissues leading to local Ang II formation and hypertension, exhibit pulmonary hypertension (PH) and remodeling small pulmonary arteries. Here we test the hypothesis that PH and pulmonary vascular remodeling in the Ren‐2 rat is modulated by intrapulmonary oxidative stress.Methods: 6 week old Ren‐2 and Sprague Dawley (SD) rats were treated with tempol (superoxide scavenger) or vehicle for 3 weeks. Right ventricular systolic pressure (RVSP), wall thickness of small pulmonary arteries (PA), intrapulmonary NADPH oxidase activity and reactive oxygen species (ROS) were compared.Results: RVSP was higher in Ren2 compared to SD (61±7 mmHg vs 36±1; p<0.01); RVSP of tempol treated Ren2 (43±6 mmHg) was not different from untreated SD. Compared to SD, medial surface area of PA was 38% greater (p<0.001) and luminal surface area was 54% less (p<0.001) in Ren2; tempol treatment prevented these changes (p<0.05). ROS and NADPH oxidase activity were elevated in Ren2 lungs compared to SD (p<0.05) and tempol treatment prevented these increases (p<0.05).Conclusions: Ren2 rats exhibit intrapulmonary oxidative stress, medial thickening of PA, and PH, and tempol treatment ameliorates these changes. This study supports a role for enhanced tissue RAS/oxidative stress as factors in development of PH and pulmonary vascular remodeling.
Increased cavernosal relaxation in type 2 diabetic Goto‐Kakizaki rats
Authors: Carneiro Fernando S. , Giachini Fernanda R. C. , Carneiro Zidonia N. , Lima Victor V. , Ergul Adviye , Tostes Rita C. , Webb R. C. 
Published: June 2021

Introduction: Diabetes mellitus (DM) is an important risk factor for erectile dysfunction (ED). Commonly used experimental models of diabetes include the chemically‐induced streptozotocin model of type 1 diabetes, which displays highly elevated glucose levels, or obesity‐induced models such as Zucker rats and db/db mice.Aim: In this study we evaluated cavernosal reactivity in Goto‐Kakizaki (GK) rats, which are not obese and display moderate changes in blood glucose, insulin resistance and blood pressure. This model is particularly relevant to ED studies since the great majority of patients with prediabetes or type 2 diabetes display mild defects in glucose‐stimulated insulin secretion, insulin resistance, hyperinsulinemia and hyperglycemia.Methods and Results: Male GK and Wistar control (C) rats were used at 18 weeks of age (n=5 and 7, respectively). Sympathetic‐mediated contractile responses (induced by electrical field stimulation (EFS), 50V, 1 ms pulse, 1–64 Hz) were attenuated in cavernosal strips from GK rats (C: 6.3±0.7 vs GK: 2.5±0.4, mN). Similarly, cavernosum from GK rats showed decreased contractions to phenylephrine (C: 7.0±0.4 vs GK: 1.9±0.2, mN) and KCl (C: 4.6±0.3 vs GK: 1.4±0.2, mN). Non‐adrenergic‐non‐cholinergic (NANC)‐induced relaxation was increased in cavernosal strips from GK rats (Figure 1), but relaxation to sodium nitroprusside was not.Conclusion: In contrast to other models of diabetes, GK rats exhibit changes in cavernosal reactivity that would facilitate erectile responses. This may be due to compensatory mechanisms activated at this stage of diabetes.
Mice with null mutation of Ceacam1 exhibit metabolic syndrome with cardiac hypertrophy
Authors: Morgan Eric E. , Ledford Kelly J , DeAngelis Anthony M , Buehler Jason , Patel Payal , Najjar Sonia M , Khouri Samer , Pierre Sandrine V 
Published: June 2021

Metabolic syndrome is a risk factor for cardiovascular disease. Because the carcinoembryonic antigen‐related cell adhesion molecule 1 (Ceacam1) regulates insulin and lipid metabolism in liver, we hypothesized that null mutation of Ceacam1 (Cc1−/−) leads to metabolic syndrome and cardiovascular abnormalities. We characterized the metabolic and cardiovascular phenotypes of six month old male Cc1−/− mice.Cc1−/− mice developed visceral obesity, elevated fasting plasma free fatty acids (FFA), and insulin resistance, as evidenced by fasting hyperinsulinemia and euglycemia (Table). Tail‐cuff measurements revealed higher systolic blood pressure in Cc1−/− mice, and echocardiography of left ventricular end‐diastolic diameter (LVDd), septal (SW) and posterior (PW) wall thicknesses revealed an increased relative wall thickness (RWT; calculated as SW+PW/LVDd). No differences in systolic function were observed (data not shown).We conclude that null mutation of Ceacam1 mimics metabolic syndrome and results in elevated systolic blood pressure and left ventricular hypertrophy with preserved systolic function.This work was supported by NIH grants DK054254 (SMJ) and HC36573 (SVP).
IL‐10 KO female mice infused with TNF‐α show impaired ACh induced relaxation as compared to IL‐10KO male mice
Authors: Zemse Saiprasad M. , Hilgers Rob H. P. , Cleghorn Donald , Chiao Chin Wei , Brands Michael , Webb R. Clinton 
Published: June 2021

Background: TNF‐α is a pro‐inflammatory cytokine, and is an important mediator of maternal endothelial dysfunction. In this study, we tested whether IL‐10 improves TNF‐α induced endothelial dysfunction.Methods: C57BL6/IL‐10 KO female and male mice were treated with saline or TNF‐α (220ng/kg/min) for 14 days. Aortic rings were isolated and mounted in a wire myograph (Danish Myotech) and stretched to a tension of 5mN. Endothelium‐dependent relaxation was assessed by constructing cumulative concentration‐response curves to acetylcholine (ACh, 0.001–10 μmol/L) during phenylephrine PE, 10 μmol/L)‐induced contraction. Endothelium‐independent relaxations were assessed by the NO donor sodium nitroprusside (SNP).Results: IL‐10 KO female mice treated with TNF‐ α showed significant impairment in ACh induced relaxation as compared to C57BL6 female mice treated with TNF‐ α (Emax = 52 ± 3% versus 76 ± 5% respectively; P<0.05). IL‐10 KO male mice treated with TNF‐α showed no significant impairment in ACh induced relaxation as compared to C57BL6 male mice treated with TNF‐α(Emax = 57 ± 3% versus 66 ± 3% respectively; P<0.05). TNF‐α infusion had no effect on endothelium‐independent relaxations by SNP in all the groups.Conclusion: The anti‐inflammatory cytokine IL‐10 prevents impairment in endothelium‐dependent vasorelaxation in response to 14 days of TNF‐α infusion which is more in female mice but not male mice.
Glu298Asp eNOS Gene Polymorphism Causes Attenuation in Exercise‐Induced Muscle Vasodilatation in Humans
Authors: Dias Rodrigo Goncalves , Alves Maria Janieire Nunes , Pereira Alexandre da Costa , Rondon Maria Urbana P. B. , Krieger José Eduardo , Krieger Marta Helena , Negrão Carlos Eduardo 
Published: June 2021

We tested the hypothesis that the vasodilatation responses to exercise were attenuated in homozygous individuals for the allele Asp298.Methods: from 287 volunteers genotyped, we studied 24 individuals: Glu/Glu (n=15, age 43±3 yr, BMI 22.9±0.3 kg/m2) and Asp/Asp (n=9, age 40±4 yr, BMI 23.5±0.9 kg/m2). Heart rate (HR), mean blood pressure (MBP) and forearm blood flow (FBF) were recorded during handgrip exercise (30% MVC).Results: FVC responses to exercise were lower in Asp/Asp, compared with Glu/Glu (Δ=0.07±0.14 vs. 0.57±0.09 units, P=.002). To investigate the mechanisms underlying the lowered vasodilatation in Asp/Asp, we studied FBF during L‐NMMA and L‐NMMA + phentolamine in a subset of 8 Glu/Glu and 7 Asp/Asp. We measured muscle sympathetic nerve activity (MSNA). L‐NMMA did not change FVC responses to exercise in Asp/Asp, compared with saline (Δ=−0.05±0.20 vs. −0.09±0.18 units, P=.52). In contrast, L‐NMMA reduced FVC in Glu/Glu (Δ0.79±0.14 vs. 0.14±0.09 units) and the difference between genotypes were no longer observed (P=.62). L‐NMMA + phento increased similarly FVC responses to exercise in Glu/Glu and Asp/Asp (Δ=1.16±0.26 vs. 0.56±0.24 units, P=.43). MBP and MSNA were similar among genotypes.Conclusion:Asp/Asp individuals have attenuated muscle vasodilatation responsiveness to exercise, which seems to be primarily mediated by a reduced nitric oxide bioavailability.
Inhibitory effects of Tumor Necrosis Factor (TNF)‐α on myoblast to myotube differentiation are attenuated by eicosapentaenoic acid (EPA)
Authors: Magee Peter , Pearson Stephen , Allen Jeremy 
Published: June 2021

Elevated concentrations of TNF‐α are associated with muscle wasting, exerted through inhibition of myogenic differentiation and enhanced apoptosis. Previously, we found that EPA, an omega‐3 fatty acid, has a protective effect against apoptosis during myogenesis and therefore we hypothesized that EPA may ameliorate the apoptotic effects of TNF‐α.To investigate this, murine C2C12 myoblasts were differentiated in culture medium containing 2% horse serum. EPA (50μM) was added at the start of differentiation and myotube formation allowed to progress for up to 5days in the presence or absence of TNF‐α (20ng/ml). Differentiation was evaluated by morphology and anti‐myosin antibody. Apoptosis was quantified by measurement of caspase activity.It was found that EPA alone had no effect on myogenesis after 5 days compared with controls, whereas TNF‐α significantly reduced (P<0.05) myosin expression after 5 days and significantly increased (P<0.001) caspase‐8 activity. The effects of TNF‐α were ameliorated for both myosin (P<0.05) and apoptosis (P<0.008) by co‐treatment with EPA.In conclusion, EPA has a protective action against the damaging effects of TNF‐α on myogenesis. Our findings support potential therapeutic applications for EPA in associated muscle wasting conditions such as ageing and during skeletal muscle regeneration following injury. Supported by the University of Salford.
IL‐6 Inhibits Hyperoxia Induced Bax Translocation Through Pi3kinase/AKT Mediated Bax Phosphorylation
Authors: Kolliputi Narasaiah V , Meloney Laura G , Kathryn Steiner M , Waxman Aaron B 
Published: June 2021

We have shown that IL‐6 over expression protects mice from hyperoxic acute lung injury (HALI) in vivo and treatment with IL‐6 protects against oxidant mediated cell death in vitro. However, the mechanisms to account for these findings are not yet known. We hypothesized that Bax, a pro‐apoptotic member of Bcl‐2 family, may play an important role in oxidant mediated cell death and that IL‐6 may block this pathway. We characterized the expression, and localization of Bax and its regulation in WT and IL‐6 lung specific over expression transgenic (IL‐6 Tg(+)) mice exposed to 100% oxygen for 72 hours in vivo. We also analyzed the same proteins in HUVEC with and without H2O2 in the presence or absence of IL‐6. In control HUVEC treated with H2O2, or WT mice exposed to 100% oxygen, there was marked induction of Bax translocation and dimirization associated with increased pJNK and p38kinase activity. In contrast, JNK or p38 kinase inhibitors, or treatment with IL‐6 inhibited Bax mitochondrial translocation and apoptosis of HUVEC cells. IL‐6 Tg(+) mice exposed to 100% oxygen, have reduced pJNK, p38 levels, enhanced Pi3kinase/AKT kinase, and increased serine phosphorylation of Bax compared with WT mice. Moreover IL‐6 treated cells or S184 transfected cells have increased Bax phosphorylation and decreased translocation. IL‐6 potently blocks either hyperoxia or oxidant‐induced Bax insertion intomitochondrial membranes. We concluded that IL‐6 is cytoprotective, in part, by suppressing Bax translocation and dimirization through Pi3kinase/AKT mediated Bax phosphorylation.This work is supported by NIH grant RO1HL074859 to Waxman A.B and NIH training grant 5 T32 HL 007874‐12 to Steiner M. K.
Developmental changes in endothelium‐dependent relaxation of the chicken ductus arteriosus
Authors: Villamor Eduardo , Ågren Pia , van der Sterren Saskia , Frazziano Giovanna , Blanco Carlos E , Perez‐Vizcaino Francisco , Cogolludo Angel L 
Published: June 2021

We tested the hypothesis that endothelium‐dependent relaxation in the chicken ductus arteriosus (DA) is developmentally regulated. Isolated DA rings from 15‐, 19‐ and 21‐day‐old chicken embryos relaxed to acetylcholine (ACh). This relaxation was unaffected by indomethacin but impaired by endothelium removal, by the NO synthase inhibitor L‐NAME, and by the soluble guanylate cyclase inhibitor ODQ, suggesting the involvement of NO. This NO production was confirmed with the fluorescent probe DAF‐2DA. The combination of apamin and charybdotoxin with L‐NAME produced a further inhibition of ACh‐induced relaxation, suggesting the participation of a putative EDHF. In the 21‐day DA, the relaxations induced by ACh and sodium nitroprusside SNP were markedly reduced and scanning electron microscopy demonstrated an irregular endothelial lining with protrusion and detachment of endothelial cells. The relaxations induced by BAY 41‐2272 and 8‐Br cGMP were not affected by age. In summary, we found that ACh induces endothelium‐dependent relaxation of the chicken DA and that NO and EDHF are involved in this response. During chicken DA closure, endothelial cells undergo morphologic and functional alterations that result in the lack of endothelium‐dependent relaxation.Supported by “Fundación de Investigación Médica Mutua Madrileña”
Lipid effects of prescription omega‐3‐acid ethyl esters plus simvastatin in subjects with hypertriglyceridemia
Authors: Maki Kevin C. , McKenney James , Lubin Barry C. , Reeves Matthew S. 
Published: June 2021

Prescription omega‐3‐acid ethyl esters (P‐OM3) are approved as an adjunct to diet for treatment of very high triglyceride (TG) levels, and are frequently used in combination with a statin to lower persistent hypertriglyceridemia. The present randomized, crossover trial evaluated 6 weeks of combination therapy with simvastatin 20 mg/d (S) plus P‐OM3 4 g/d (Lovaza™) or placebo in 39 men and women with TG 200 to 600 mg/dL and non‐HDL cholesterol (C) above the subject's treatment goal after a 5‐week diet lead‐in. Median baseline concentrations of non‐HDL‐C, TG, LDL‐C, and HDL‐C were 209, 304, 163 and 38 mg/dL, respectively. Non‐HDL‐C decreased by 40.0% with S+P‐OM3 compared to 34.3% for S + placebo (p<0.001). The following also showed favorable changes (p<0.05) with S + P‐OM3 compared to S + placebo: VLDL‐C (−41.5% vs. −22.4%), TG (−43.6% vs. −28.7%), total‐C (−31.0% vs. −26.4%), HDL‐C (+16.4% vs. +10.6%), apolipoprotein B (−31.6% vs. −28.4%), total‐C:HDL‐C ratio (−39.1% vs. −32.6%) and TG:HDL‐C ratio (−50.6% vs. −36.9%). LDL‐C (−37.2% vs. −38.4%) and apolipoprotein A‐I (+0.9% vs. +4.3%) responses did not differ significantly between treatments. Thus, S + P‐OM3 and dietary counseling improved non‐HDL‐C and other lipid and lipoprotein parameters to a greater extent than S alone.This was funded as an Investigator‐Initiated Trial (NCT00487591) by Reliant Pharmaceuticals, Inc.