bluuebunny/crossref_metadata_2025_split huggingface dataset:
Investigating the Role of Mitochondrial Fission in Cardiac Myocyte Hypoxia/Re‐oxygenation‐Induced Cell Death
Authors: Pratt Amina Malika , Heine Erin , Chen Qian , Barsotti Robert , Young Lindon 
Published: November 2023

Currently there is no effective pharmacological intervention to attenuate myocardial ischemia reperfusion (IR) injury. Understanding the mechanisms that govern IR injury would benefit myocardial infarction, coronary bypass and organ transplant patients. Recent studies suggest that cardiac mitochondria undergo excessive fragmentation during IR, a process that is called fission. Increased mitochondrial fission may lead to increased cell death during IR. Mitochondrial fission has been shown to be mediated by association of dynamin related protein‐1(Drp1), a GTPase that translocates from the cytosol to interact with outer mitochondrial membrane proteins, fission protein 1 and mitochondrial fission factor, to induce fission. We hypothesize that attenuating mitochondrial fission during IR may prove to be an effective strategy to mitigate IR injury. To test this hypothesis, we used a pharmacological inhibitor of Drp‐1 GTPase activity, Mdivi‐1(MW=353 g/mol). We subjected murine cardiac myocytes (HL‐1 cells) to 12 hours of hypoxia in hypoxic buffer (pH 6.8, no glucose or pyruvate) and then 1 hour of re‐oxygenation in normoxic media (pH 7.4), in the presence/absence of Mdivi‐1 (5–25μM). We predicted that HL‐1 cells subjected to simulated IR (SIR) would exhibit increased cell death in relation to their normoxic control counterparts, and that Mdivi‐1 treated cells would have attenuated SIR‐induced cell death. Cell death was determined by trypan blue (0.3%) staining. Preliminary data shows that control SIR cells (n=4) exhibited 25% cell death, by contrast Mdivi‐1 treated cells only showed 7% (5μM, n=4) and 11% (25μM n=4) cell death. Normoxic untreated (n=3) and Mdivi‐1 treated cells (5 and 25 μM; n=3) showed only 2% cell death in all study groups. The data suggests that inhibiting Drp‐1 may mitigate cardiac cell death during SIR. Future studies will determine the role of Drp‐1 in the regulation of mitochondrial dynamics during SIR.Support or Funding InformationThis study was supported by the Department of Bio‐Medical Sciences, Division of Research and the Center for Chronic Disorders of Aging at Philadelphia College of Osteopathic Medicine
P2X receptor inhibition protects THP‐1 monocytes against cytolysis by α‐hemolysin from Escherichia Coli and leukotoxin from Aggregatibacter actinomycetemcomitans
Authors: Fagerberg Steen K , Skals Marianne G , Praetorius Helle A 
Published: November 2023

The Repeats in Toxins (RTX) α‐hemolysin (HlyA) from E. coli and leukotoxin A (LtxA) from A. actinomycetemcomitans are important virulence factors for ascending urinary tract infections and aggressive forms of periodontitis respectively. Upon insertion into the plasma membrane ATP is released through the toxin pore and is as signaling molecule essential for the HlyA‐ and LtxA‐induced erythrocyte damage. The immediate effects after ATP release are a massive erythrocyte shrinkage and phosphatidylserine exposure in the outer leaflet of the plasma membrane. These events are eminent for the erythrocytes to be recognized and engulfed by the monocyte cell line THP‐1. Here, we investigate how these toxins and ATP, affect the survival and function of THP‐1 monocytes.By measurements of [Ca2+]i, we demonstrate that the THP‐1 express functional P2X (P2X1, P2X4 and P2X7) and P2Y2 receptor. We show that desensitization of either P2X1 by either low (0.001 μM) or more pronounced of P2X4/P2X7 by high concentrations of ATP (0.1 to 1 mM) increases the survival rate of THP‐1 cells attacked by either HlyA or LtxA in a calcein release assay. This protection is also found by specific blockage of the ATP sensitive receptors P2X1 (100 μM NF449) or P2X7 (100 μM oxATP or A804589). By erythrocyte phagocytosis assay, we determined that low dose HlyA (EC25) preconditioning is increasing the function of erythrocyte clearance at the place of injury.These findings suggest a new target for protecting monocytes during pore‐former toxemia – both pharmacologically through P2X blockers or receptor desenzitisation. Both mechanisms may be relevant for improving monocyte survival and function in patients suffering from infection with RTX producing bacteria.Support or Funding InformationFunded by the Danish Council for Independent Research, MEMRANES and Lundbeck Foundation
Umbilical cord stromal cell (UCSC) exosomes protect tubular epithelial cells from gentamicin injury
Authors: Borges Fernanda Teixeira , Novaes Antonio , Schor Nestor 
Published: November 2023

Bone Marrow Mesenchymal Stromal Cells (MSCs) and Umbilical Cord Stromal Cells (UCSC) protect the kidney against nephrotoxic insults. This effect could be paracrine, possibly mediated by extracellular vesicles. Exosomes (EXOs) are extracellular vesicles that transfer mRNA and microRNA to the recipient cells, mediating the communication between them. Mir 126 mediates the protective effect of stem cell microvesicles. The goal of the present study was to analyze the effects of EXOs from MSCs and UCSC on proximal tubular epithelial cells from rats (RPTC) exposed to gentamicin (genta). UCSC and MSCs were maintained in culture conditions and every 3 days the culture medium was collected. EXOs were extracted through filtration in the 0.1μm filter, followed by ultracentrifugation (100,000g during 2h). Mir 126 from stromal cells and EXOs were extracted and analyzed by real time‐PCR. RPTC cells were exposed to gentamicin (2mM) in the presence or absence of exosomes (50 μg/ml), DNA damage and proliferation was analyzed by H2Ax and BrDU immunofluorescence, respectively. The expression of p21 and c‐myc was analyzed in RPTC through western blot. Mir 126 expression was increased in exosomes in comparison to stromal cells. It was increased in BM‐MSC exosomes (2.52 ± 0.12 AU) in comparison to UCSC exosomes (1.2 ± 0.2 AU). The treatment with UCSC‐EXO, but not with MSC‐EXO, stimulated the proliferation and decreased DNA damage induced by gentamicin in tubular cells. MSC‐EXO increased proliferation and decreased DNA damage when mir126 was depleted from exosomes with 126 antimir. RPTC cells treated with UCSC‐EXO increased the tumor suppressor protein p21 and increased in cell cycle progress protein c‐myc. MSC‐EXO did not show the same effect. Our results suggest that stromal cell exosomes carry mir 126 and this microRNA could be related to the paracrine protective effect of umbilical stromal cell exosome.Support or Funding InformationSupported by FAPESP, CNPq, CAPES and FOR
Generation of induced pluripotent stem cells from Epstein‐Barr Virus immortalized lymphoblastoid cell lines using Episomal vectors
Authors: Saito Kazuyoshi , Mayhew Christopher , Stanton Lori , Towbin Jeffrey Allen , Purevjav Enkhsaikhan 
Published: November 2023

IntroductionGenerating functional cardiomyocytes from human induced pluripotent stem cells (iPSCs) derived from fresh peripheral blood mononuclear cells (PBMCs) or skin fibroblasts has been widely implemented for drug discovery, cardiotoxicity screening, and modeling cardiac diseases and development in vitro. However, generating patient‐specific iPSCs using standard approaches has not been possible when patients are deceased or fresh blood or fibroblasts are unavailable. In these cases iPSC generation from alternative cell sources, such as Epstein‐Barr virus (EBV) immortalized lymphoblastoid B cell lines (LCLs), as unlimited sources, is desirable. Though several papers have been published that outline iPSCs generation from EBV‐LCLs, the efficiency remains low. The aim of this study was to establish a robust technique for iPSC generation from EBV‐LCLs.MethodsFour EBV‐LCLs from control individuals and patients were used. Multiple assessments of different conditions such as 1) cell number, 2) plasmid combination, 3) transfection methods (chemical or electroporation using 4D‐Nucleofector™ X unit System (LONZA) machine) and design, 4) media and cell culture conditions, including small molecule combinations, with or without feeder‐free, media changing methods, and 5) expansion techniques were performed.ResultsWe established the optimal conditions for generation of iPSCs from EBV‐LCLs included: a cell number of 1×10^5/100ul solution (P3 primary cell 4D‐Nucleofection Kit (Lonza)), the EO‐100 program on LONZA ZAP electroporation, and Thomson's plasmids combination (l‐Myc plasmid included) of total 10ug. We developed a specific media change approach using media containing small molecules. The harvesting time was around 20 days.ConclusionsWe improved and adjusted the conditions for establishing a robust system of generating iPSCs from EBV‐LCLs. Our approach resulted in 100% colony generation. We are in the process of improving the cell culture conditions in order to increase efficacy.Support or Funding InformationJohnson & Johnson K.K. Codman Neurovascular Fellowship for Pediatric Interventional Cardiology in Japan (2012)
Examining the Functional Role of Fragile X Related Protein 1(FXR1P) in Adult Neurogenesis
Authors: Patzlaff Natalie , Nemec Kelsey , Zhao Xinyu 
Published: November 2023

FXR1P is a member of the fragile X family of RNA binding proteins, which includes FMRP and FXR2P. Both FMRP and FXR2P regulate adult neural stem cells (aNSCs) and neurogenesis, a process affected in a number of neurological and neuropsychiatric disorders, including Fragile X syndrome. Although FXR1P has been implicated in diverse developmental processes and neuropsychiatric diseases, its role in neurodevelopment is not well understood. The goal of this study is to elucidate the function of FXR1P in adult neurogenesis. We used an inducible triple transgenic mouse model (Fxr1‐cKO; Nestin‐CreERT2; Ai14::tdTomato) that allows us to investigate how FXR1P deficiency in aNSCs affects proliferation and fate specification. Deletion of FXR1 in aNSCs resulted in fewer adult‐born cells and reduced populations of radial glia‐like cells, neuroblasts, immature neurons, neurons, and astrocytes. We hypothesize that this reduction in new cell numbers resulted from impaired proliferation, which we confirmed in vitro using primary aNSCs. In addition, we found that mRNAs related to cell cycle progression were downregulated in vitro. Ongoing work includes identification of mRNAs regulated by FXR1P in aNSCs. These results indicate that FXR1P plays an important role in regulating aNSC self‐renewal and maintenance in the adult brain.Support or Funding InformationNIH (MH080434, MH07897) to X.Z.; Waisman Center core grant NIH(P30HD03352); Molecular and Cellular Pharmacology Training Grant NIH(T32 GM008688) to N.E.P.; a NIMH‐NIH NSRA (F31MH103945) to N.E.P.; the Wayne and Jean Roper Memorial Wisconsin Distinguished Graduate Student Fellowship to N.E.P and the Hilldale Undergraduate Fellowship to KN.
Exposure to a Diet High in Saturated‐fat during Pre‐natal and Post‐weaning Brain Development Alters Hippocampal Gene Expression and Behavioral Indices for Anxiety and Depression
Authors: Page Kathleen C , Winkelmann Maegan E , Anday Endla K 
Published: November 2023

BackgroundWe have shown previously that high‐fat diets during critical periods of development perturb both hypothalamic and hippocampal function. More specifically, adult male rats in our studies that were exposed to dietary saturated fat during gestation and after weaning had perturbations in key hormones regulating metabolism, impaired spatial learning and memory, and alterations in both hypothalamic and hippocampal gene expression.ObjectiveOur current hypothesis is that maternal and postweaning exposure to excess saturated fat promotes an increased emotionality which is associated with altered expression of genes mediating hippocampal synaptic function.Design/MethodsDams were fed control or high fat diet (45% kcal saturated fat) prior to mating, pregnancy, and lactation. Male offspring from control and high fat‐fed dams were weaned to control (CC or HFC) or to high‐fat diet (CHF or HFF). At 120 d the forced swim test was used to measure differences in time spent immobile which is an index for depressive‐like behavior and at 150 d they were evaluated using the elevated plus maze which is an index for anxiety‐like behavior. Animals were sacrificed 2 weeks after completion of behavioral testing. Serum leptin, insulin and corticosterone were measured by radioimmunoassay; RT‐PCR and ELISA methods were used to analyze hippocampal gene expression.ResultsHippocampal synaptophysin mRNA level was significantly reduced in HFF offspring (maternal diet effect, P=0.044) and was susceptible to the modulating effects of the post‐weaning diet (post‐weaning diet effect, P=0.002). Reductions in the mRNA levels of ionotropic glutamate receptor subunit, AMPAR1 (P=0.003), glial‐derived neurotrophic factor, GDNF (P=0.034), microtubule‐associated protein 2, MAP2 (P=0.025) and synaptosomal‐associated protein, SNAP25 (P=0.011) were detected in offspring exposed to excess fat in the postweaning diet. Expression of the glutamate receptor subunit, AMPAR2, was not significantly different among the four groups. Protein expression for GDNF and SNAP‐25 was reduced in response to excess fat in both the maternal and postweaning diet, and an interaction between the maternal and the postweaning high fat diet was detected for MAP2 protein expression. Changes in hippocampal gene expression were associated with anxiety‐like and depressive‐like behavior using the elevated plus maze or forced swim test, respectively.ConclusionsThese data support the hypothesis that prenatal and postweaning exposure to dietary saturated fat during critical periods of brain development has a complex and detrimental effect on hippocampal synaptic plasticity that may lead to affective disorders in adult life.Support or Funding InformationSupported by Bucknell University Biology Department
Optogenetic stimulation of distinct populations of anterior preoptic neurons reveals a locus for the reciprocal control of thirst
Authors: Abbott Stephen B , Geerling Joel C , Saper Clifford B 
Published: November 2023

The median preoptic nucleus (MnPO) and organum vasculosum of the lamina terminalis (OVLT) regulates hydro‐mineral homeostasis in mammals. The neurochemical composition of this region is complex and the possibility of divergent roles for MnPO/OVLT neurons in thirst regulation has never been addressed. To this end, we injected a Cre‐dependent Channelrhodopsin2‐mCherry viral vector into the MnPO/OVLT of VGluT2‐ires‐Cre and VGAT‐ires‐Cre mice to selectively stimulate excitatory and inhibitory neurons respectively. Stimulation of excitatory MnPO/OVLT neurons caused water consumption in satiated mice (N=8). Water and physiological saline consumption during stimulation declined with successive trials over a 15 minute period, and fully recovered after 1 hour of rest, suggesting a pre‐systemic feedback gating of stimulus‐induced ”thirst”. Photostimulation of inhibitory MnPO/OVLT neurons reduced water consumption by 30% during 30 minutes of water access in dehydrated mice (N=8), but had no effect on food consumption following food deprivation. Axonal tracing of MnPO/OVLT excitatory and inhibitory neurons revealed overlapping innervation of areas important in hydro‐mineral homeostasis, including the paraventricular nucleus of the hypothalamus, sub‐fornical organ and supra‐optic nucleus. Together, these result indicate that the MnPO/OVLT region exerts a bi‐directional influence on thirst.Support or Funding InformationNational Health and Medical Research Council of Australia Early Career Fellowship (GNT1052674) (to S.B.A.)NIH‐NINDS R25 #NS070682 (to J.C.G.) NIH NS072337 (to C.B.S.)
Vasodilation and Hyperemia during Passive Limb Movement: Impact of Acute Sympathetic Activation
Authors: Trinity Joel Douglas , Lee Joshua F , Garten Ryan S , O'Keefe Zachary Barrett , Layec Gwenael , Wray David Walter , Richardson Russell S 
Published: November 2023

Heightened muscle sympathetic nerve activity (MSNA) is associated with impaired vasodilatory capacity and vascular dysfunction linked to aging and cardiovascular disease. The contribution of elevated MSNA to the vasodilatory response during continuous passive limb movement (PLM), a novel method to assess vascular function, has not been determined. This study sought to test the hypothesis that elevated MSNA will negatively impact the vasodilatory response to PLM in healthy young men (n=11, 25±2 yr). Post exercise circulatory occlusion (PECO) following 2 min of isometric handgrip (HG) exercise performed at 25% (PECO‐25%) and 40% (PECO‐40%) of maximum voluntary contraction (MVC) was utilized to incrementally engage the metaboreceptors and augment MSNA. Control (CON‐25% and CON‐40%) trials, without PECO, were performed to account for changes due to HG exercise. PLM was performed 2 min after the cessation of exercise and central (photoplethysmography) and peripheral hemodynamics (Doppler ultrasound) were assessed. MSNA was directly recorded by microneurography (n=8). MSNA was incrementally augmented during PECO‐25% (+ 8±3 burst/min) and PECO‐40% (+ 15±4 burst/min) and returned to pre‐HG levels during CON trials. Vasodilation, assessed by the overall change in leg vascular conductance (LVC) during PLM, was reduced following HG exercise in all conditions (Δ in peak LVC range; −15 to −41%). The peak change in LVC was not different between CON‐25% (7.2±1 ml/min/mmHg) and PECO‐25% (8.1±1.4 ml/min/mmHg, p <0.05) while the peak change in LVC during PECO‐40% (5.4±1.1 ml/min/mmHg) was significantly attenuated compared to PECO‐25% (p < 0.05). These findings indicate that alterations in MSNA can modify the vasodilatory response to PLM and that the magnitude of reduction in vasodilation during PLM appears to be graded in relation to the elevation in MSNA. In conclusion, elevations in MSNA that are typically exhibited with aging a cardiovascular disease, impact the vasodilatory response to PLM. Thus, basal sympathetic tone is important to consider when comparing vasodilatory capacity across heterogeneous groups.Support or Funding InformationAHA SDG (1850039), VA RR&D CDA2 (1215)
Functional Changes of Baroreceptor Afferent, Central and Vagal Efferent Components in the Baroreflex Arc: Effects of SOD1 Overexpression in Mice
Authors: Chen Jin , Hatcher Jeff , Gu He , Cheng Zixi Jack 
Published: November 2023

Overproduction of reactive oxygen species (ROS), such as the superoxide radical (O2‐.), is associated with diseases which compromise cardiac autonomic function. Overexpression of SOD1 may offer protection against ROS damage to the cardiac autonomic system, but reductions of O2‐. may interfere with normal cellular functions. Therefore, we need to consider whether or not SOD1 overexpression in animals can affect the neural components of the baroreflex loop in normal animals. We have selected the C57B6SJL‐Tg (SOD1)2 Gur/J mouse as a model to determine whether SOD1 overexpression alters baroreflex sensitivity (BRS), aortic depressor nerve (ADN) function, and heart rate (HR) responses to ADN and vagal nerve stimulation. Under isoflurane anesthesia, left femoral artery and vein of mice were catheterized and MAP and HR were measured. Baroreflex control of HR (baroreflex sensitivity: BRS) and aortic depressor nerve functions were assessed in response to hypotension and hypertension which were induced by sequential injections of sodium nitroprusside and phenylephrine. In addition, HR responses to electrical stimulation of aortic depressor nerves and vagal efferent nerves were measured. Our data indicated that SOD1 overexpression: 1) increased aortic depressor nerve function, 2) decreased HR responses to vagal efferent nerve stimulations, 3) did not alter HR responses to aortic baroreceptor afferent nerve stimulation, 4) did not change baroreflex control of HR. Collectively, our findings suggest that SOD1 overexpression preserved the normal BRS, but may alter the function of baroreceptor afferent, central, and vagal efferent components differently. While SOD1 overexpression enhanced aortic depressor nerve function and central component function, a decreased vagal efferent control over HR may explain an unchanged BRS in C57B6SJL‐Tg (SOD1)2 Gur/J mice.Support or Funding InformationNIH RO‐1 HL‐58727 to Zixi (Jack) Cheng
The Effect of Oral Hygiene on Cardiac Health as Determined by Heart Rate Variability
Authors: Bujnoski Emily Elizabeth 
Published: November 2023

Cardiac disease is the number one cause of death throughout the world (“The 10 Leading Causes of Death in the World, 2000 and 2012”, 2014). An indicator of physiological cardiac health is heart rate variability (HRV). HRV, determined using an electrocardiogram, measures the variation of time between R‐intervals of consecutive heartbeats due to autonomic influence. Higher variability between these R‐intervals indicates better cardiac health. HRV can be divided into low frequency and high frequency oscillations, whereas more low frequency indicates increased sympathetic activity and more high frequency indicate parasympathetic activity. This relationship is made possible via a Fast Fourier Transformation. The aim of this study is to relate these autonomic implications of the heart to oral hygiene, because little research in this field exists today. Over the course of five months, a random voluntary sample of college‐aged individuals completed oral hygiene surveys including information on brushing, flossing, and numbers of dental caries (cavities). HRVs were then taken from the sample group. Initial analysis shows significant positive correlation between low frequency HRV and number of cavities (>2) (n=55, r=0.71, p=0.014). The findings indicate a potential relationship between poor oral health and specific autonomic cardiac outcomes.Support or Funding InformationFunding for this project provided by the Elon University Undergraduate Research Program, the Elon College Fellows Program, and Elon University's Summer Undergraduate Research Program.
Electrical Stimulation of the Carotid Sinus Nerve Improves Hemodynamics and Heart Rate Variability in L‐NAME Hypertensive Rats
Authors: Souza Gean Domingos , Silva Luiz Eduardo Virgilio , Dias Daniel Penteado Martins , Santos‐Almeida Fernanda Machado , Castania Jaci Airton , Salgado Helio Cesar , Fazan Rubens 
Published: November 2023

Baroreflex activation by electrical stimulation of the carotid sinus (CS) has been recently used to treat resistant hypertensive patients. In the present study, we evaluated the effects of long‐term electrical stimulation (ES) of CS in L‐NAME hypertensive rats.Hypertension was induced in male Wistar rats by administration of L‐NAME (70 mg/kg, per os) for 10 days. 7 days after initiating L‐NAME administration the animals were anesthetized and implanted with a catheter into the femoral artery and received, subcutaneously, a miniaturized battery‐operated electrical stimulator connected to electrodes placed around the left CS. On the following day, basal AP was directly recorded for 60 min and the stimulator was turned on. Electrical pulses (1 ms, 3 V, 30 Hz) were delivered to the CS, intermittently (20/20s ‐ on/off), for the next 48 h. Basal mean arterial pressure (AP) from L‐NAME hypertensive rats was 176±3 mmHg but showed a marked fall (D= −51±5 mmHg) at the onset of ES of the CS. At the end of the stimulation period only a mild rise in AP was seen; however, the AP recorded during the first 60 min after ES of the CS was lower (159±3 mmHg) than before the stimulation period. Spectral analysis showed that ES of the CS reduced the LF power of AP spectra (10.0±1.9 to 3.7±0.4 mmHg2, p=0.014) and also increased the power of PI spectra at HF range (1.8±0.4 to 3.4±0.8 ms2, p=0.028). Moreover, LF/HF ratio of PI spectra was also markedly reduced after the stimulation period (0.42±0.09 to 0.14±0.02, p<0.01). In conclusion, ES of the CS for 48 h was effective to reduce the AP lasting 1 h after the stimulation period. In addition, the AP and heart rate variability strongly suggests a lower sympathetic modulation upon the cardiovascular system after ES of the CS in L‐NAME hypertensive rats.Support or Funding InformationFAPESP, CAPES, CNPq, FAEPA