bluuebunny/crossref_metadata_2025_split huggingface dataset:
In vivo cardiac 31P MRS in a mouse model of heart failure
Authors: Prompers Jeanine J , Bakermans Adrianus J , van Nierop Bastiaan J , Abdurrachim Desiree , Nicolay Klaas 
Published: June 2021

ObjectiveTo investigate myocardial energy status in a mouse model of heart failure using in vivo 31P magnetic resonance spectroscopy (MRS).MethodsMale C57BL/6 mice underwent thoracic aortic constriction (TAC) surgery, inducing pressure‐overload cardiomyopathy, and were measured seven weeks after surgery (n = 5). Healthy wild‐type mice served as controls (n = 4). Cardiac cine 1H MR images were made for reference purposes and to quantify left ventricular (LV) function. Cardiac 31P MR spectra were measured from a ~6 mm cubic voxel enclosing the end‐diastolic LV myocardium using ECG triggered, respiratory gated 3D Image‐Selected In vivo Spectroscopy (ISIS).ResultsLV end‐diastolic volume and LV mass normalized to body weight were higher in TAC mice compared to controls (91.7 ± 19.0 versus 61.8 ± 6.0 μL and 4.4 ± 0.6 versus 3.1 ± 0.2 mg/g, P < 0.01), whereas LV ejection fraction was reduced in TAC mice (45.4 ± 20.0 versus 64.4 ± 5.2 %, P < 0.05). Myocardial phosphocreatine‐to‐ATP ratio was lower in TAC mice when compared to healthy controls (0.8±0.2 versus 1.2±0.2, P < 0.05).ConclusionDecreased EF in TAC mice is accompanied by decreased phosphocreatine‐to‐ATP ratio, indicating a disturbed energy homeostasis in this mouse model of heart failure. This research was funded by a VIDI grant from the Netherlands Organisation for Scientific Research (NWO).
Endogenous ATP and the Modulation of Sympathetic Vasoconstriction in Contracting Skeletal Muscle of Humans
Authors: Kirby Brett S , Richards Jennifer C , Crecelius Anne R , Garcia Leora J , Luckasen Gary J , Larson Dennis G , Dinenno Frank A 
Published: June 2021

Exogenous ATP administration in humans can blunt sympathetic vasoconstriction in a dose‐dependent manner, similar to what occurs within contracting skeletal muscle (sympatholysis). Here, we tested the hypothesis that endogenous ATP increases during exercise and is associated with the magnitude of sympatholysis in humans (N = 9). We measured deep venous plasma [ATP] and forearm blood flow (Doppler ultrasound), and calculated ATP effluent (FBF x [ATP]) at rest and during 5 and 15% MVC rhythmic handgrip exercise (EX), before and during superimposed lower body negative pressure (LBNP; −40 mmHg). LBNP‐induced vasoconstriction was similar during 5% EX vs rest (ΔFBF = −25 ± 2% vs −33 ± 5%), whereas this was blunted during 15% EX (−4 ± 2%). LBNP at rest did not alter [ATP] nor ATP effluent. During the 5% EX trial, [ATP] and ATP effluent were 44 ± 7, 70 ± 9, and 50 ± 10 nmol/L and 1 ± 1, 7 ± 1, and 4 ± 1 nmol/min at rest, EX, and EX + LBNP, respectively. During the 15% EX trial, [ATP] and ATP effluent were 47 ± 5, 79 ± 11, and 71 ± 8 nmol/L and 1 ± 1, 16 ± 3, and 14 ± 1 nmol/min at rest, EX, and EX + LBNP, respectively. We conclude that endogenous ATP release is increased during exercise and must remain elevated during sympathetic stimulation in order to blunt the vasoconstrictor response. Further, the contribution of intravascular ATP to vascular control may ultimately be dependent on an interaction between blood flow and [ATP].Supported by NIH HL102720
Opioid μ‐receptors in the rostral medullary raphe modulate hypoxia‐induced hyperpnea in unanesthetized rats
Authors: Dias Mirela Barros , Nucci Tatiane B , Branco Luiz Guilherme Siqueira , Gargaglioni Luciane H 
Published: June 2021

It has been suggested that the medullary raphe (MR) plays a key role in the physiological responses to hypoxia. As the rostral MR (rMR) expresses an extensive population of opioid μ‐receptors, we studied the putative role of opioid μ‐receptors in the rMR region on ventilation in normal and 7% hypoxic conditions. We measured pulmonary ventilation and the body temperatures of male Wistar rats before and after the selective opioid μ‐receptor antagonist CTAP (D‐Phe‐Cys‐Tyr‐D‐Trp‐Arg‐Thr‐Pen‐Thr‐NH2, cyclic, 0.1 μg/0.1 μL) was microinjected into the rMR during normoxia or after 60 minutes of hypoxia. The animals treated with intra‐rMR CTAP exhibited an attenuation of the ventilatory response to hypoxia (430 ± 86 mL kg−1 min−1) compared to the control group (790 ± 82 mL kg−1 min−1) (P<0.05) due to a reduced tidal volume (3.0 ± 0.41 versus 6.1 ± 0.6 ml kg−1; P<0.05). During hypoxic recovery, the ventilation remained reduced in the CTAP intra‐rRM group. No differences in the Tb were observed among groups during hypoxia. These data suggest that opioids acting on μ‐receptors in the rMR exert an excitatory modulation of hyperventilation induced by hypoxia.Financial support: FAPESP, CNPq, PRONEX.
Functional expression of the extracellular Ca2+‐sensing receptor in pulmonary neuroepithelial bodies
Authors: Lembrechts Robrecht , Brouns Inge , Schnorbusch Kathy , Pintelon Isabel , Kemp Paul J , Timmermans Jean-Pierre , Riccardi Daniela , Adriaensen Dirk 
Published: June 2021

The extracellular Ca2+‐sensing receptor (CaR) is a multimodal sensor that allows cells to detect and respond to changes in the extracellular Ca2+ concentration [Ca2+]o. Besides its role in Ca2+ homeostasis, the CaR has been shown in various specialized cells, suggesting its involvement in multiple cellular functions. Prenatal CaR expression was detected in mouse airway epithelium between E11,5 and E16,5 and was shown to play a role in airway branching morphogenesis. In postnatal lung tissue, the CaR so far has not been reported. Neuroepithelial bodies (NEBs) are densely innervated groups of neuroendocrine airway epithelial cells, believed to represent complex sensory receptors that are ideally placed to detect changes in the microenvironment. Immunostaining of postnatal mouse lungs showed a selective CaR expression on the basolateral membrane of NEB cells. Confocal Ca2+ imaging of NEBs in live mouse lung slices revealed that NEBs respond with a Ca2+ rise both to changes in [Ca2+]o and to various known CaR agonists (spermine, neomycin, calcimimetic R‐568). All responses were blocked by Calhex, a calcilytic CaR antagonist. The presented expression and proven functionality of the CaR in postnatal NEBs offer interesting perspectives for further unraveling NEB cell physiology.Support: IWT fellowship SB/81162 (RL); FWO grants G.0081.08 (DA) and G.0589.11N (DA, JPT); UA grants GOA BOF 2007 (DA) and KP BOF 2006 (IB)
Identification of lung priming area in frog brainstem, adjacent to the lung oscillator, distinct from the buccal oscillator: homologous to RTN/pFRG?
Authors: Baghdadwala Mufaddal , Duchcherer Maryana , Wilson Richard J.A. 
Published: June 2021

Data from mammals and frogs suggest tetrapods have an anatomically‐discrete inspiratory oscillator, necessary and sufficient for expression of the powerstroke phase of lung inflation (preBötzinger Complex in mammals; Lung Area in frogs). In mammals a second Pre‐Inspiratory / late‐phase expiratory oscillator has been hypothesized; this oscillator likely resides in the retrotrapezoid/parafacial respiratory group (RTN/pFRG) and is “conditional”, recruited during high respiratory demand. In isolated frog brainstems, lung bursts often have a powerstroke and priming phase. Though the priming phase is always observed with a subsequent powerstroke, the priming phase is “conditional”: powerstrokes can occur without a priming phase.Here we identify a region of the frog brainstem necessary and sufficient for the priming phase. This priming area is adjacent to the area that produces the powerstroke (between CNVII‐IX) and distinct from the buccal area (caudal of CN X). Using AMPA microinjections to locally excite the priming area, we demonstrate ectopic priming bursts uncoupled from powerstroke bursts. We propose the priming and powerstroke areas are homologous to the PreI and PreBötC, respectively. We further postulate that rhombomeric differences may be explained by a “gene cassette” for air breathing rhythmogenesis, turned on in different rhombomeres in different clades. Work funded by NSERC.
Sexually dimorphic expression of S1PR2 as candidate for susceptibility to CNS autoimmunity
Authors: Cruz-Orengo Lillian , Basak Sarah Alison , Dorsey Denise , Crosby Seth Daniel , Klein Robyn Sue 
Published: June 2021

Multiple Sclerosis (MS) is characterized by blood brain barrier (BBB) dysfunction with consequent autoimmune attack of oligodendrocytes. MS exhibits both a high sex bias and a sexually dimorphic progression, affecting more women than men whom exhibiting the relapsing‐remitting (RR) form. Specimens from MS patients and mice with EAE, exhibit relocation of CXCL12 to the lumenal surfaces of CNS vessels. This alteration in CXCL12 expression impacted on the infiltration of immune cells enhancing EAE severity. Here we show that naïve female SJL mice, which develop RR–EAE, exhibit lumenal CXCL12 expression within white matter microvasculature, while naïve male SJL mice, which do not develop RR‐EAE, exhibit ablumenal CXCL12 expression. Other experiments showed significantly increased expression of the Sphingosine 1‐Phosphate Receptor 2 (S1PR2), in the cerebella of female SJL mice compared with male SJL cerebella and cortices for both genders. Antagonists of S1P receptors have previously been shown to be effective targets for the treatment of EAE and MS, mainly through immunosuppressive mechanisms, inducing lymphopenia in vivo. Our preliminary data, however, suggests that an alternative receptor, S1PR2, may be a specific target for manipulation of BBB biology during CNS autoimmunity. In addition, our data reveals that white matter expression of this receptor exhibits sexual dimorphism, which suggests that it might be relevant for RR‐MS neuropathogenesis.Research support: National Institute of Neurological Disorders and Stroke, 1F32NS074824‐01 (LCO), National Multiple Sclerosis Society, RG3982A‐2 (RSK) and Dana Foundation (RSK).
Stress‐induced activation of distinct subpopulations of neurons in the basolateral amygdala of the rat
Authors: Bolanos Juan M. , Hamdan Jameel N. , Rosales Victor M. , Gosselink Kristin L. 
Published: June 2021

Previous studies showed that repeated exposure to 6h restraint stress causes hippocampal plasticity and shifts the profile of activated basolateral amygdala (BLA) neurons, suggesting alterations in mechanisms that affect learning and memory in repeatedly stressed rats. The purpose of this study was to determine whether a lesser stress exposure can induce similar consequences, and whether the effects are sex‐specific. Adult male and female rats were acutely (A; 30min x 1d) or repeatedly (R; 30min x 14d) restraint stressed and compared to unstressed controls (C). Stress occurred near the beginning of the light cycle (0900h). Series of perfused brain sections (30μm) were stained immunohistochemically for Fos, and the number of Fos‐expressing cells was quantified in the BLA. The number of Fos‐positive BLA cells tended to be higher in females than males in all groups, and varied by group: C/Male=47±19, A/Male=251±57, R/Male=152±44; C/Female=169±79, A/Female=151±83, R/Female=235±41. One significant difference was seen between C and A males (p<0.05). The data suggest that BLA responses to short‐term emotional stress vary according to sex and stress exposure. Further analyses will be done using fluorescent immunohistochemistry to quantify the specific types of stress‐activated BLA neurons in both sexes.Supported by: UTEP's COURI Program, NIH/NCRR 5G12RR008124, and the Egbert Endowment (to KLG).
Hypoxic environments cause differential facial shape variation in zebrafish
Authors: Parsons Trish Elizabeth , Weinberg Seth M , Tsang Michael , Vieira Alexandre R 
Published: June 2021

High altitude populations exhibit increased risk for craniofacial defects including cleft lip, microtia and branchial arch anomaly complex. A hypoxic maternal environment is thought to be the mechanism responsible for these malformations. In this study, zebrafish were used to test the hypothesis that different hypoxic levels will variably affect facial shape. Three sets of zebrafish were raised in uniform conditions with the exception of dissolved oxygen level. One group was raised at normal conditions (controls, n=7), the second at 30% hypoxia (30H) for 24 hours at 24 hours post fertilization (hpf) and the third at 50% hypoxia (50H) for 24 hours at 24 hpf. Larvae from each group were collected at 120 hpf and stained for cartilage. Dorsoventral images were taken of each specimen and then landmarked to capture viscerocranial morphology. A 2D morphometric analysis was performed on the landmark coordinates. The results show that the mean shape of each group was significantly different and the first two principal components showed a clear separation of the three groups with controls at one end of the shape spectrum, the 50H at the other end and 30H spanning the variation in between. This result indicates that low oxygen levels can cause differential variation in facial shape, which has implications not only for high altitude fetal health, but also other environments, behaviors and genes that affect fetal oxygen delivery.This project is supported by the University of Pittsburgh Central Research Development Fund (CRDF).Grant Funding Source : University of Pittsburgh Central
Identification of a proteoglycan‐associated regulatory region active during central nervous system development
Authors: Van Hong Annie , Feenstra Jennifer M , Pira Charmaine U , Oberg Kerby C 
Published: June 2021

Lmx1b is a homeodomain transcription factor necessary for limb, kidney, eye and central nervous system (CNS) development. Lmx1b KO mice show reduced cerebellum and tectum formation, loss of dopaminergic/serotonergic neurons, ocular malformations, and distal ventral‐ventral limb symmetry. Direct downstream targets of Lmx1b in the brain and limb remain unknown. Recent microarray studies have implicated the proteoglycans Keratocan, Lumican, and Decorin as possible downstream targets of Lmx1b. Interestingly, these proteoglycans cluster to a locus in the genome (KLD). Using in silico analysis, we identified a conserved non‐coding region with a known Lmx1b binding site (CNR Peak 3). We hypothesize that Lmx1b directly regulates KLD via CNR Peak 3. We isolated CNR Peak 3 and generated a green fluorescent protein (GFP) reporter construct. This construct was electroporated into the chick embryo at Hamburger‐Hamilton (HH) 4 and HH10. GFP was visualized under fluorescent microscopy. GFP expression was detected in the chick HH10 neural tube and HH19 surrounding the developing midbrain and cerebellum. At HH19, Lmx1b and KLD mRNA expression overlap GFP expression. The data suggests CNR Peak 3 plays a role in the regulation of KLD during CNS development. We suspect that Lmx1b mediates KLD regulation through the Lmx1b binding site in CNR Peak 3. Further studies are underway investigating Peak 3 CNR in other Lmx1b patterned tissues.Grant Funding Source: National Institutes of Child Health and Human Development
Effects of laminar shear stress on expression of MT1‐MMP in rat bone marrow‐derived mesenchymal stem cells
Authors: Qin Wang Han 
Published: June 2021

ObjectiveTo investigate the effect of laminar shear stress on the expression of membrane type‐1 matrix metalloproteinase (MT1‐MMP) in rat bone marrow‐derived mesenchymal stem cells (rMSCs).MethodsrMSCs were isolated from SD rat lower extremities and loaded by laminar shear stress with the parallel‐plate flow chamber system, and then the expression of MT1‐MMP mRNA of rMSCs was examined by real‐time PCR.ResultsShear stress with different magnitude of 5, 15, 30 dynes/cm2 all induced MT1‐MMP mRNA expression, especially high shear stress, 30 dynes/cm2, which was time‐dependent. The expression of MT1‐MMP mRNA was inhibited by SB202190, an inhibitor of p38, but enhanced by wortmannin, an inhibitor of PI3K/Akt.ConclusionShear stress can activate the expression of MT1‐MMP. The amount of MT1‐MMP expression is closely related to stimulating time and the strengths of shear stress, and p38MAPK and PI3K/Akt signal pathway may play a critical role during the process.
Cisplatin induces differentiation of breast cancer cells
Authors: Prabhakaran Praseetha , Hassiotou Foteini , Filgueira Luis 
Published: June 2021

Breast tumours are heterogeneous, including cells with cancer stem cell properties and more differentiated tumour cells. As breast cancer stem cells are often resistant to chemotherapy, recent efforts have been focusing on treatments that may shift them towards a more differentiated phenotype, making them more susceptible to treatment. Here, we examined whether t cisplatin induces cell differentiation in four breast cancer cell lines that represent different types of breast tumours (BT549, MDA‐MB‐468, MDA‐MB‐231, MCF7). Cisplatin treatment of 20 μM reduced cell viability from 100% to 50–80%, depending on the cell line. Flow cytometric quantification showed that treatment with cisplatin induced a 18–65% decrease of stem cell marker expression (CD49f, SSEA4) and a 4–97% increase in expression of differentiation markers (CK18, Tubulin). It is concluded that in addition to its effects on cell survival, cisplatin shifts breast cancer cell lines towards a more differentiated phenotype.Research Support: Malaysian Ministry of Higher Education Postgraduate Scholarship
Abnormal Proliferation and Defective Multilineage differentiation Potential of Adipose‐Derived Stem Cells Isolated from Dystrophin and Utrophin Knockout Mice
Authors: Sohn Jihee , Kozemchak Adam , Oyster Nick , Thompson Seth Davis , Lu Aiping , Gharaibeh Burhan , Tang Ying , Wang Bing , Huard Johnny 
Published: June 2021

Adipose derived stem cells (ADSCs) hold potential in cell therapy for a variety of musculoskeletal injuries and diseases including Duchenne Muscular Dystrophy (DMD). DMD is a genetic disease characterized by progressive weakening of the skeletal, cardiac, and diaphragmatic muscles. Using double knock‐out mice (dKO) for dystrophin and utrophin which is a DMD model that better emulates the human phenotype of the disease in mice, we determine if ADSCs from dKO mice are affected in their proliferation and differentiation capacities compared to wild type (WT) ADSCs. ADSCs were isolated from fat tissue of 6 week old dKO‐homo (dys−/−utro−/−), dKO‐hetero (dys−/−utro+/−) and C57BL WT mice and flow cytometry was used to confirm positive expressions of Sca‐1, CD34, CD44 and CD29. Cell proliferation and apoptotic rates investigated using a Live Cell Imaging system showed dKO ADSCs have a higher proliferation rate than WT cells. This may explain the gradual muscle weakness and pseudohypertrophy observed in DMD. Myogenesis, adipogenesis and chondrogenesis are impaired in dKO ADSCs. Impaired myogenesis observed with dKO cells may be a secondary effect of the increased proliferation observed with those cells. These results suggest a dysfunction in the dKO ADSCs and that blocking the exhaustion of ADSCs and stem cell therapy could be used to modulate adipose tissue formation in the muscles of DMD patients to restore structure and function.Grant Funding Source: NIH
Neuroprotective role of Alpha lipoic acid (ALA) in arsenic (As) induced developmental neurotoxicity in rat pups
Authors: Dhar Pushpa , Kaushal Parul , Mehra Raj D 
Published: June 2021

AimTo determine the role of exogenous ALA on arsenic induced morphological features and synaptophysin (SYP) expression in cerebellum of Wistar rat pups.Material and methodsThe experimental group of animals received either NaAsO2 alone (1.5 or 2.5mg/kg bw) or NaAsO2 + ALA (70 mg/kg bw) from postnatal day (PND) 1 to 21 by intraperitoneal (i.p) route whereas the controls received distilled water by the same route. Behavioral tests for evaluation of the arousal, cognition, vestibular and motor coordination ability (cliff avoidance, tail hung, negative geotaxis and midair righting) were carried out on PND 7, 9, 10 and 15 respectively. On PND 22, cerebellum obtained from perfusion fixed animals was processed for paraffin embedding and sectioning. Immunohistochemical localization (SYS) was carried out on cryostat sections.Results and conclusionDuring the experimental period, an apparent decrease (dose dependent) was noted in the performance of NaAsO2 alone exposed pups as compared to the controls. The animals receiving ALA with NaAsO2 showed an apparent improvement in these parameters. Substantial recovery was also evident in As induced disrupted cerebellar cytoarchitecture in animals receiving ALA with NaAsO2. SYP expression, localized mainly in the molecular and granular layers showed an apparent decrease in the NaAsO2 alone exposed animals as compared to control and ALA supplemented group, supporting the hypothesis of the important role of As induced oxidative stress in developmental neurotoxicity and the amelioration of these effects by exogenous ALA.
Whi3p Localizes To Cytoplasmic Foci During Slow Growth At High OD In Saccharyomyces cerevisiae
Authors: Dégallier Joshua Paul , Tembreull Jarrod , Theede Kelly , Segal Scott P. 
Published: June 2021

Regulation of cell cycle progression is necessary to ensure that cells do not undergo uncontrolled division, resulting in reduced cell volume. The cell cycle is regulated by several checkpoints, the most important of which is the G1/S checkpoint. In yeast, the G1/S checkpoint is sensitive to the levels of the mammalian cyclin D homolog Cln3p. To ensure that the cell passes through the G1/S checkpoint at the appropriate time, Cln3p levels throughout G1 phase are, in part, controlled by local translation of the CLN3 mRNA by Whi3p, an ER associated RNA binding protein.Previously, Whi3p was found to genetically interact with SBP1, which encodes a protein involved in general translational repression. This implies that Sbp1p may work in conjunction with Whi3p to control local translation of the CLN3 mRNA. In support, we found that Whi3p is found in cytoplasmic foci at high OD after nutrient exhaustion, where growth is reduced, but are not found during log phase growth. Future studies will determine whether these foci are P‐bodies or stress granules. Furthermore, strains lacking Whi3p have no change in P‐body formation at log phase. Our working model is that Sbp1p represses translation of CLN3 mRNA as it localizes to the endoplasmic reticulum. To ensure repression as the CLN3 mRNA enters the cytoplasm, Sbp1p may associate with the mRNA in the nucleus, as Sbp1p contains a 2‐3‐1 Nuclear Export Sequence.
Construction and characterization of a null allele of the hfq gene of the dissimilatory metal reducing bacterium Shewanella oneidensis
Authors: Brennan Christopher , Keane Meaghan , D'Agostino Christine , Goulet Matthew , Sexton Zachary , Hoegler Karl , Tjaden Brian , Pellock Brett 
Published: June 2021

Shewanella oneidensis is a dissimilatory metal reducing bacterium that can utilize a range of terminal electron acceptors when grown under anaerobic conditions. Our primary goal is to identify and characterize genes that encode small regulatory non‐coding RNAs (sRNAs) in S. oneidensis. sRNA genes are regulated by changes in environmental conditions and can themselves regulate other genes by inexact base pairing to their mRNA targets. We are particularly interested in sRNAs that may regulate the process of metal reduction.The highly conserved RNA chaperone protein Hfq has been widely implicated in bacterial sRNA function. We have constructed a null allele of the S. oneidensis hfq gene. The S. oneidensis hfq mutant has a modest delayed growth phenotype. In addition, our mutant displays reduced survival in stationary phase. Our hfq mutant also exhibits a decreased rate of Cr(VI) reduction when grown under anaerobic conditions compared to the rate of Cr(VI) reduction by wild type S. oneidensis. We are currently evaluating the growth and survival of the Shewanella hfq null mutant. We are also investigating the mutant's sensitivity to a variety of physical stresses, evaluating the capacity of the hfq mutant to reduce metals other than Cr(VI), and determining the role of Shewanella hfq in sRNA function.This research is funded by a grant from the RI‐INBRE program, award # P20RR016457‐10.