bluuebunny/crossref_metadata_2025_split huggingface dataset:
The potential of N‐methylpyrrolidone to prevent osteoporosis and enhance bone regeneration in vivo (1139.5)
Authors: Gjoksi Bebeka , Ghayor Chafik , Weber Franz 
Published: June 2021

Osteoporosis is a chronic, skeletal disease highly prevalent in post‐menopausal women influenced by hormonal factors causing a huge burden on health care in an aging society. We previously demonstrated that NMP is a bioactive drug which enhances bone regeneration in vivo and acts as an enhancer of bone morphogenetic protein (BMP) in vitro. NMP also inhibits osteoclast differentiation and attenuates bone resorption. The present study used animal models established for the evaluation of enhanced osteoporosis through double ovariectomy (OVX) and treated systemically with different doses of (NMP). With this treatment we want to describe the preventive effect of NMP on bone mass loss.Female Sprague‐Dawley rats with an approximate weight of 220‐250g were randomly divided into sham‐operated group (Sham) either treated or not with NMP and four ovariectomized subgroups as OVX (control), OVX treated with three different graded doses of NMP. Bilateral ovariectomy or Sham operations were performed as previously designated and the weight of the animals was measured weekly. We assessed the pharmacological effects of NMP against osteoporosis by evaluating the body weight, serum biochemical parameters, bone mineral density (BMD), dynamic histomorphometry of bone and bone histomorphology.The results showed that over a 15 week period, in OVX rats the increase in body weight, serum osteocalcin levels and decreases of BMD were significantly reversed by NMP treatment. Additionally, the effect of the three different treatment dosages of NMP correlated dose‐dependently with their effect on bone resorption. Mineral apposition rate (MAR) showed the protective activity of NMP through promotion of bone formation and suppression of bone resorption.These results suggest that NMP has a remarkable antiosteoporotic activity, and may be a promising candidate for treatment of postmenopausal osteoporosis induced by estrogen deficiency.Grant Funding Source: Swiss National Science Foundation
Expression of vitamin D receptor and 1α‐hydroxylase in epicardial fat: association to plasma 25‐hydroxyvitamin D level in coronary artery disease patients (1139.8)
Authors: Corsi Romanelli Massimiliano , Vianello Elena , Briganti Silvia , Malavazos Alexis , Dozio Elena 
Published: June 2021

25‐hydroxyvitamin D (25OHD) is the main circulating vitamin D form and 1α‐hydroxylase (CYP27B1) is the key enzyme which activates 25OHD in tissues. In adipose tissue, reduced vitamin D and increased vitamin D receptor (VDR) levels have been associated to fat accumulation and inflammation.Alterations in epicardial fat (EAT) biology (i.e. increased fat thickness and inflammation) have been described in patients with coronary artery disease (CAD) but it is unknown whether low plasma level of 25OHD and/or inadequate levels of VDR and CYP27B1 at EAT level may contribute to these EAT functional alterations.Our aim was to evaluate in CAD patients the relationship between plasma 25OHD level and gene expression of VDR and CYP27B1 at EAT level.Plasma 25OHD was quantified by an immunoluminometric assay. Gene expression was performed by microarray.CAD patients had low 25OHD level. After patient stratification according to 25OHD level, we observed increased expression of VDR and reduced expression of CYP27B1 at EAT level only in patients with 25OHD deficiency (< 20 ng/mL) and insufficiency (20‐30 ng/mL).We may conclude that in CAD patients, EAT tries to compensate reduced plasma 25OHD level by increasing VDR expression. Anyway, due to the impairment in 25OHD activation, the local vitamin availability seems to be reduced. How this may contribute to EAT functional alterations observed in CAD needs further investigation.Grant Funding Source: Supported by DiaSorin S.P.A., Vercelli, Italy
The mechanism of amphetamine‐mediated trafficking of the dopamine transporter (1145.1)
Authors: Underhill Suzanne , Thiels Edda , Amara Susan 
Published: June 2021

Acute amphetamine (AMPH) exposure elevates extracellular dopamine by a variety of mechanisms including increasing the rate of internalization of the plasma membrane dopamine transporter (DAT). We report here that AMPH also activates the small GTPases, Rho and Rac. In recombinant expression systems, primary cultures and midbrain slices, activation of Rho and the downstream Rho‐kinase (ROCK) triggers endocytosis of DAT. Inhibition of RhoA activity blocks AMPH‐induced DAT internalization, while Rac1 inhibition has no significant effect on DAT trafficking. ROCK inhibitors also prevent AMPH‐induced DAT internalization. Intriguingly, we found that AMPH must enter the cell to initiate this cascade. Further, intracellular AMPH also increases cAMP, leading to the phosphorylation of Rho by protein kinase A (PKA) that inactivates Rho and serves as a break on DAT internalization, thus demonstrating an important interaction between PKA‐ and RhoA‐dependent signaling in mediating the actions of AMPH. In agreement with our observations in cell lines and brain slices, we have also shown that the activation of receptors that couple to PKA in dopamine neurons within the brain can antagonize the behavioral effects of AMPH in mice. These observations imply the existence of a novel intracellular target that mediates the effects of AMPH on Rho and cAMP signaling and suggest new pathways to target in order to disrupt AMPH action.Grant Funding Source: Supported by the National Institute of Mental Health Intramural Program.
Microarray approach in experimental hyperthyroidism reveals two novel responsive genes in the rat heart (1148.8)
Authors: Moriscot Anselmo , Rosanski Andrei , Takano Ana Paula , Garcia Antonio , Campos Juliane , Ferreira Julio , Barreto‐Chaves Maria Luiza 
Published: June 2021

In order to get further insight upon the effects of Thyroid hormone (T3) in the heart, we have used a microarray approach to identify responsive genes in rats submitted to T3 injections for 12, 24h and 7 days. Firstly, we have compared 5 different algorithms to analyze microarray data and found MAS5 to be the best fit in our model. We have detected novel responsive genes at the intercalated disk and sarcomere M‐band levels. qRT‐PCR analysis and western blot confirmed a transient increase in cadherin‐13 expression (2.7 fold for qRT‐PCR and 2.4 for Western Blot, both p<0.05) peaking at 24 hours of T3 treatment and a progressive decrease of M‐protein gene expression (0.2 fold, p <0.05, at 7 days of T3 treatment). Because M‐protein is a structural sarcomeric protein and has a predicted role in sarcomere stability we decided to further investigate cellular/molecular mechanisms. M‐protein is up regulated in hypothyroidism (3.4 fold) and repressed by T3 in a dose dependent manner in vivo and also in cultured neonatal cardiomyocytes. Reporter assays revealed that the M‐protein promoter is responsive to T3. siRNA M‐protein knock down showed reduced contractility, highlighting the importance of this protein for sarcomere stability. We conclude that T3 quickly and strongly repress M‐protein at the transcriptional level, which might help to explain the long‐term deleterious effects of T3 in the heart.Grant Funding Source: FAPESP and CNPq
Characterization of cardiovascular performance during ischemia‐reperfusion injury in obese vs. lean Ossabaw swine (1150.4)
Authors: Sassoon Daniel , Goodwill Adam , Conteh Abass , Noblet Jillian , Mather Kieren , Tune Johnathan 
Published: June 2021

This study examined the effects of obesity/metabolic syndrome (MetS) on left ventricular pressure‐volume relations at baseline and in response to ischemia‐reperfusion injury. Measurements were obtained in lean and obese Ossabaw swine at rest, following 30 min occlusion of the left circumflex artery, and 2 hours after the release of the occlusion. Baseline end‐diastolic volume (83±5 ml vs. 74±5 ml) and cardiac output (2215±389 ml/min vs. 2511±389 ml/min) were not significantly different in lean vs. MetS swine. However, mean arterial pressure was ~40% higher in MetS swine at rest and during reperfusion, while heart rate increased ~15‐20 beats/min with ischemia‐reperfusion in both groups. Assessment of inotropic status revealed that both cardiac output and blood pressure were augmented relative to end‐diastolic filling volumes in MetS vs. lean swine under all conditions (p<0.001). These apparent differences in cardiac function were associated with a marked reduction in the time to ischemia‐induced ventricular fibrillation in lean (17.5±7 min; n = 3 of 6) vs. MetS (3.3±1 min; n = 4 of 6) swine. These findings suggest that increases in blood pressure and cardiac function in MetS, at rest and following ischemia‐reperfusion injury, are independent of changes in filling volume and could contribute to increased susceptibility to fatal ventricular arrhythmias.Grant Funding Source: Supported by HL117620; This publication was made possible in part by Grant Number TL1 TR000162 (A. S
Syndecan‐4 promotes myocardial stiffness by regulating collagen expression and cross‐linking in response to pressure overload (1152.2)
Authors: Herum Kate , Lunde Ida , Skrbic Biljana , Tønnessen Theis , Louch William , Hasic Almira , Sjaastad Ivar , Linke Wolfgang , Gomez Maria , Christensen Geir 
Published: June 2021

Pressure overload of the heart leads to myocardial stiffening due to excessive production and cross‐linking of collagen, thereby compromising diastolic function. We recently identified the focal adhesion proteoglycan syndecan‐4 (syn4) as important for collagen expression in response to mechanical stress. Here we investigate the effect of syn4 deletion on the mechanical properties of the left ventricle following pressure overload. Passive tension increased in skinned muscle fiber bundles from wild‐type (WT) mice following aortic banding and this response was significantly blunted in syn4‐/‐ mice. Total collagen content determined by hydroxyproline quantification was increased in WT but not in syn4‐/‐ mice. Furthermore, mRNA levels of the collagen cross‐linking enzyme lysyl oxidase (LOX) were dramatically increased in WT left ventricles and mechanically stressed cardiac fibroblasts, whereas this response was blunted in syn4‐/‐ mice and cardiac fibroblasts, suggesting impaired collagen cross‐linking following mechanical stress in mice lacking syn4. Finally, recombinant extracellular syn4 and collagen I formed a precipitate when mixed in vitro, suggesting a direct role for syndecan‐4 in collagen fiber organization. In conclusion, we demonstrate reduced passive tension in left ventricular tissue of syn4‐/‐ mice possibly due to reduced ECM production and attenuated collagen cross‐linking.Grant Funding Source: Supported by the Norwegian Health Association and the Norwegian Research Council
Inhibition of lysyl oxidase activity reverses fibrosis and improves cardiac function (1152.8)
Authors: El Hajj Milad , El Hajj Elia , Bradley Jessica , Gardner Jason 
Published: June 2021

The collagen crosslinking enzyme, lysyl oxidase (LOX), is elevated in human dilated cardiomyopathy and heart failure, but it is not known if LOX plays a causative role in disease. However, clinical evidence shows that diuretics with LOX inhibitory properties are more effective at slowing the progression of heart failure. Using the aortocaval fistula (ACF) rat model of volume overload, we assessed the efficacy of LOX inhibition to reverse cardiac fibrosis and dysfunction in rodents with established cardiac disease. Serial echocardiography was used to evaluate cardiac structural and functional changes. LOX inhibition (100 mg/kg/d BAPN; osmotic minipumps) was initiated 8 wks post‐surgery in ACF and SHAM‐operated rats. Treatment continued for 6 wks and hearts were collected for analysis. Left ventricular (LV) sections were stained with PSR for collagen volume fraction (CVF). Protein expression was assessed in LV homogenates by WB. Untreated ACF had significantly increased LV LOX expression (65% increase), concomitant with LV dilatation (43% increase), depressed fractional shortening (26% decrease), increased collagen cross‐linking (52% increase), and interstitial fibrosis (CVF; 135% increase) relative to SHAM (p<0.05). LOX inhibition reversed fibrosis (CVF; Treated ACF vs SHAM; p=NS) and partially restored cardiac function (20% increase vs Untreated ACF). However, there was no significant reversal of LV hypertrophy or dilatation. LV NADPH oxidase‐4 was increased in untreated ACF (52% increase vs SHAM), but was not different in treated ACF, indicating a possible role for oxidative stress in the observed beneficial effects of LOX inhibition. These data identify inhibition of LOX activity as a potential therapeutic approach for the regression of cardiac fibrosis and improvement of function in heart failure patients.Grant Funding Source: Supported by LSUSOM REF grant (jdg) and the American Heart Association GSA 11GRNT7700002 (jdg)
Dendritic cell superoxide and isoketals activate T cells and promote angiotensin II hypertension (1153.2)
Authors: Kirabo Annet , Fontana Vanessa , Davies Sean , Roberts L. Jackson , de Faria Ana , Galindo Cristi , Wu Jing , Bikineyeva Alfiya , Dikalov Sergey , Loperena Roxana , Vinh Antony , Amarnath Venkataraman , Guzik Tomasz , Bernstein Kenneth , Shen Xiao , Moreno Heitor , Harrison David 
Published: June 2021

Oxidative injury and inflammation contribute to the genesis of hypertension but the mechanisms involved are not fully understood. We describe a new pathway where angiotensin II promotes dendritic cell (DC) activation of T cells and ultimately hypertension. NADPH oxidase‐dependent superoxide production is increased 5‐fold in DCs from hypertensive mice. This is associated with DC accumulation of protein‐isoketal adducts (isoketals are highly reactive γ‐ketoaldehydes produced via the isoprostane pathway of free radical mediated lipid peroxidation) and production of IL‐6, IL‐1β and IL‐23. DCs from hypertensive but not sham mice promote survival and proliferation of CD8+ T cells. Chemically diverse isoketal scavengers not only prevent activation and immunogenicity of DCs, but also attenuate angiotensin II hypertension (142.59 ± 8.98 mmHg vs. 175.53 ± 5.19 mmHg in controls). Moreover, adaptive transfer of DCs from hypertensive mice prime development of hypertension in response to a subpressor dose of angiotensin II (157.45 ± 33.86 mmHg vs. 119.90 ± 17.33 mmHg in controls). Plasma F2‐isoprostanes, which are formed in concert with isoketals, were found to be elevated in humans with treated hypertension and were markedly elevated in patients with resistant hypertension when compared to well‐controlled and normotensive subjects (23.2±11.5 vs. 18.3±10.3 vs. 11.6±7.0 pg/mL, p<0.05). We conclude that angiotensin II‐induced hypertension activates DCs, in large part by causing superoxide production and formation of isoketals. These studies define a new mechanism of hypertension and identify a potential new therapeutic approach for this disease.Grant Funding Source: AHA Post‐Doctoral Fellowship (13POST14440041), R01HL039006, R01HL105294, P01HL095070, P01GM015431
Lysophosphatidic acid signaling is required for NADPH oxidase activation during agonist stimulation in pulmonary microvascular endothelial cells (1153.8)
Authors: Vazquez‐Medina Jose Pablo , Chatterjee Shampa , Fisher Aron 
Published: June 2021

The phospholipase A2 (PLA2) activity of peroxiredoxin 6 (Prdx6) is required for NADPH oxidase 2 (Nox2) activation in pulmonary microvascular endothelial cells (PMVEC; JBC 286:1196, 2011). Lysophosphatidylcholine is a major product of the PLA2 activity of Prdx6 that is readily metabolized to lysophosphatidic acid (LPA). LPA is a bioactive lipid that signals through distinct G protein‐coupled receptors (LPA receptors 1‐5). LPA receptor activation results in the stimulation of signaling pathways regulated by small GTPases, such as the Nox2 cytosolic activator Rac1. We propose that LPA receptor signaling activates Nox2 by stimulating Rac1 in PMVEC. Treatment with Ki16425, a selective antagonist of the LPA receptors 1/3, decreased Rac1 translocation to the plasma membrane during phorbol 12‐myristate 13‐acetate (PMA) stimulation in PMVEC; as demonstrated by in situ proximity ligation assays (Duolink®) and western blotting of isolated plasma membrane proteins. In the same way, LPA receptor blockade decreased superoxide and hydrogen peroxide production in response to PMA stimulation. These results suggest that LPA signaling is required for Nox2 activation during agonist stimulation in PMVEC and that Rac1 is a main target of LPA receptor signaling during this process.Grant Funding Source: Supported by HL105509
Comparison of two methods to automatically quantify infarct size in rat isolated hearts following global ischemia and reperfusion (1154.6)
Authors: Riess Matthias , Shidham Sushrut , Nabbi Raha , Gaggl Wolfgang , Lerch‐Gaggl Alexandra 
Published: June 2021

Infarct size (IS) remains the gold standard to estimate cardiac injury in many animal models. 2,3,5‐triphenyltetrazolium chloride (TTC) staining delineates infarcted from non‐infarcted tissue. Here, we compare manual image analysis to commercially available software using Bayesian differentiation and a newly developed automated freeware algorithm using color thresholding. As part of a study on genome‐dependent cardioprotection we analyzed 855 slices from 156 isolated rat hearts subject to 30/120 min ischemia/reperfusion after different protective treatments. Hearts were cut into 2 mm transverse slices and TTC‐stained, slices scanned on green background and infarcted areas measured manually and automatically by VisiomorphTM and Image J (NIH) whose color threshold T was varied from 125 to 133 to determine the best differentiation for IS. Statistics: linear regression; alpha 0.05. VisiomorphTM correlated well with manual measurements as did Image J where T129 provided the best agreement. IS measurement by either software provides equal results to manual measurements. Both methods enable fast, operator‐independent and reliable IS assessment. Potential shortcomings such as lack of discrimination are offset by significant time‐ and cost‐savings and a better longitudinal resolution by analyzing more slices per heart. Supported by Department of Veterans Affairs (CARA‐026‐10F) and NIH.Grant Funding Source: Supported by Department of Veterans Affairs and NIH.
Transcriptome‐wide RNA sequencing analysis of rat skeletal muscle feed arteries (1156.12)
Authors: Jenkins Nathan , Padilla Jaume , Thorne Pamela , Martin Jeffrey , Rector R , Davis J , Laughlin M. 
Published: June 2021

We employed next generation RNA sequencing (RNA‐Seq) technology to determine the influence of obesity on global gene expression in skeletal muscle feed arteries. Transcriptional profiles of the gasctrocnemius and soleus muscle feed arteries (GFA and SFA, respectively) and aortic endothelial cell‐enriched samples from obese Otsuka Long Evans Tokushima Fatty (OLETF) and lean Long Evans Tokushima Otsuka (LETO) rats were examined. Obesity produced 282 upregulated and 133 downregulated genes in SFA and 163 upregulated and 77 downregulated genes in GFA (false discovery rate < 10%) with an overlap of 93 genes between the arteries. Within LETO, there were 89 upregulated and 114 downregulated genes in the GFA compared to the SFA. There were 244 upregulated and 275 downregulated within OLETF (FDR < 10%) in the GFA compared to the SFA, with an overlap of 76 differentially expressed genes common to both LETO and OLETF in both the GFA and SFA. A total of 396 transcripts were found to be differentially expressed between LETO and OLETF in aortic endothelial cell‐enriched samples. Overall, we found (i) the existence of heterogeneity in the transcriptional profile of the SFA and GFA within healthy LETO rats, (ii) that this between‐vessel heterogeneity was markedly exacerbated within the hyperphagic, obese OLETF rat, and (iii) a greater number of genes whose expression was altered by obesity in the SFA compared to the GFA. Also, results indicate that in OLETF rats, the GFA takes on a relatively more pro‐atherogenic phenotype compared to the SFA.Grant Funding Source: Supported by NIH RO1HL036088, T32‐AR048523, VHA‐CDA2 1299‐02
3β‐Diol, an endogenous androgen, elicits relaxation via estrogen receptor activation in rat mesenteric and cerebral arteries (1156.15)
Authors: Gonzales Rayna , Ramirez Angeleah , O'Connor Devin 
Published: June 2021

Nongenomic vasorelaxant effects of androgens, such as testosterone and dihydrotestosterone (DHT), have been shown to be beneficial in a variety of vascular beds. These nongenomic vasorelaxant actions have been shown to be independent of androgen receptor (AR) activation. However, the vascular properties and associated mechanisms for endogenous androgen metabolites downstream of these potent AR agonists have not been investigated. Therefore, we studied the direct vasorelaxing effects of the endogenous DHT metabolite, 5α‐androstane 3β, 17β diol (3β‐diol), on contracted mesenteric and basilar arterial rings isolated from male rats via wire myography. Previous studies have demonstrated that the actions of 3β‐diol are mediated by estrogen receptor beta (ERβ). Thus, we confirmed the presence of ERβ expression along with AR and ERα in mesenteric and cerebral arteries using western blot and RT‐PCR. In the contractile studies, 3β‐diol (10‐9 to 10‐5 M) reduced phenylephrine‐induced contractions in mesenteric rings. Similarly, serotonin‐induced contractions in basilar rings were also reduced by the addition of 3β‐diol (10‐9 to 10‐5 M). Vasorelaxing efficacy for 3β‐diol was greater in mesenteric rings (Rmax = 77.34%±17.05) compared to basilar rings (Rmax = 65.92% ±7.74). In both mesenteric and basilar arteries, non‐selective ER inhibition with ICI 182780 and selective ERβ inhibition with PHTPP attenuated 3β‐diol relaxation compared to vehicle. Based on these findings it is concluded that 1) the endogenous androgen metabolite, 3β‐diol, mediates direct vasorelaxation of arterial rings via ERβ and 2) regional differences in vasorelaxation of 3β‐diol exist between the peripheral and cerebral circulations.Grant Funding Source: Supported by the UA Sarver Heart Center
Skeletal muscle mitochondrial function in severely burned children improves following rehabilitative exercise (1159.13)
Authors: Chao Tony , Suman Oscar , Herndon David , Sidossis Labros , Porter Craig 
Published: June 2021

Severe burn injury results in skeletal muscle mitochondrial dysfunction. In this study, we determined in skeletal muscle mitochondrial function in children with severe burns (n=8) at discharge from hospital and following 6 weeks of rehabilitative exercise (REX).Mitochondrial respiration was determined in permeabilized myofibers following the addition of substrates, ADP, succinate, and oligomycin. After which, the respiratory control ratio (RCR), substrate control ratio (SCR), and coupling control ratio (CCR) were calculated.Maximum mitochondrial respiration significantly increased after exercise training (12.7±2.1 pmol/mg/sec vs. 38.6±5.4 pmol/mg/sec, p<0.01), RCR (1.0 vs. 1.5) and SCR (1.1 vs. 1.7) increased while the CCR decreased (0.7 vs. 0.4) post REX.Skeletal muscle mitochondrial function is increased in burn victims following REX. Increased RCR and SCR indicate greater ADP and succinate sensitivity. The decrease in CCR suggests that mitochondria are more coupled post REX. These data suggest that early REX restores skeletal muscle mitochondrial function in burn survivors.Grant Funding Source: Supported by NIH (P50‐GM60338, R01‐HD049471, R01‐GM056687), and SHC (84090, 84080 and 84085) grants.