bluuebunny/crossref_metadata_2025_split huggingface dataset:
Systems Biology Tools and Data for a Better Understanding of Mechanisms of Toxicity.
Authors: Boue Stephanie 
Published: June 2021

Risk assessment in the context of 21st century toxicology relies on the elucidation and understanding of mechanisms of toxicity. While no single experiment allows deciphering toxic mechanisms at the interplay of complex pathways, network models built from the knowledge accumulated in the scientific literature enable a more comprehensive view of the changes to the system caused by toxic or pharmaceutical agents. Moreover well‐designed and rich data collection in the context of toxicology or pharmacology will further advance risk assessment. Bringing the scientific community together and harnessing the wisdom of crowds is the method used by sbv IMPROVER to verify methods and biological networks used in systems toxicology, pharmacology and diagnostic through a series of collaborative competition challenges. We will present past challenges and their outcome regarding methods to classify biological samples based on their transcriptomics profiles and to assess the translatability of key pathways between human and rat cell cultures. Moreover, we will show how we apply crowd‐sourcing methods to verify and fine tune network models of lung biology.Our goal at Philip Morris International R&D is to develop and assess potentially reduced risk alternatives to combustible cigarettes in order to reduce the harm caused by smoking, which is one of the leading causes of preventable diseases. The next sbv IMPROVER challenge will focus on evaluating large pre‐clinical Systems Toxicology datasets generated from experimental systems exposed to conventional cigarette smoke and the aerosol generated from a prototype noncombustible product's aerosol.
Serotonin 5‐HT2C Receptor of the Rat Detrusor Muscle: Evaluation of the Atypical Antipsychotics Olanzapine and Ziprasidone on the Isolated Rat Detrusor Muscle
Authors: Morris Michelle , Gossell‐Williams Maxine , Nwokocha Chukwuemeka 
Published: June 2021

BackgroundAtypical antipsychotics are preferentially prescribed over typical agents for greater efficacy in treating symptoms associated with schizophrenia and related psychoses. However, these antipsychotics have been found to reduce bladder function in patients. Antagonism of serotonin (5‐HT) receptor, 5‐HT2C has been implicated as the cause. An in‐vitro preparation using the isolated rat detrusor muscle may be used to determine the effect of atypical agents Olanzapine and Ziprasidone on bladder contraction.Method: Bladders isolated from male Sprague Dawley rats (250–350g), were divided into longitudinal strips and immersed in Kreb's solution with carbogen (95% O2:5% CO2)at 370C. After equilibration at 0.5g tension, the strips were stimulated with electric field stimulation (EFS) while adding 5‐HT (0.01‐30 µM and 0.1 nM‐1 µM) cumulatively at half‐log concentrations. A control concentration‐response curve (CRC) was constructed after which another CRC was constructed in the presence of Olanzapine (0.3nM‐3 µM) and Ziprasidone (0.001 nM‐1 nM) during EFS.Results: 5‐HT caused concentration dependent potentiation of EFS induced contractions and therefore may be a co‐regulator of micturition with ACh. Olanzapine (P蠄0.00) and Ziprasidone (P蠄0.00) significantly inhibited 5‐HT potentiated contractions in a concentration dependent manner.ConclusionsThe results suggest that atypical agents Olanzapine and Ziprasidone have potential to cause urinary retention. This effect may be due to affinity for 5‐HT receptors in the bladder.Funding: UWI, Office of Graduate Studies & Research
Divergent Effects for Celecoxib and Diclofenac on Hemodynamic and Left Ventricular Actions of Cyclosporine in Female Rats
Authors: Ibrahim Karim , El‐Yazbi Ahmed , El‐Gowelli Hanan , El‐Mas Mahmoud 
Published: June 2021

The combined use of cyclosporine (CSA), a potent immunosuppressant, and nonsteroidal antiinflammatory drugs (NSAIDs) in arthritis is a common clinical practice. In this study, we evaluated whether diclofenac (nonselective COX‐1/COX‐2 inhibitor) and celecoxib (selective COX‐2 inhibitor) interact variably with CSA hemodynamics in conscious female rats. Changes evoked by acutely administered CSA in blood pressure (BP), heart rate (HR), HR variability (HRV), and myocardial contractility were assessed in the absence and presence of diclofenac or celecoxib. Compared with vehicle values, CSA (10 mg/kg i.v.) caused immediate and sustained increases in BP and decreases in the pulse pressure index and HR. CSA also increased the time and frequency domain indices of HRV and shifted the cardiac sympathovagal balance towards parasympathetic dominance. The pressor effect of CSA was intensified and abolished in rats pretreated i.v. with diclofenac (10 mg/kg) and celecoxib (10 mg/kg), respectively. The autonomic and PPI effects of CSA were blunted in the presence of celecoxib in contrast to no effect for diclofenac. We also report that celecoxib, but not diclofenac, eliminated the elevated LV contractility (dP/dtmax) and isovolumic relaxation constant (Τau, τ), which reflects the cardiac diastolic function, that accompanied the CSA‐evoked pressure load. The data highlight the preferential capacity of celecoxib to mitigate the pressor effect of CSA and consequent alterations in cardiac performance and autonomic balance in female rats.Supported by the ALEX‐REP Grant Fund, Alexandria University, Egypt (Grant HLTH‐13‐01).
Helium Postconditioning Regulates Caveolin‐1/‐3 Translocation and Gene Expression
Authors: Flick Moritz , Oei Gezina , Albrecht Martin , Hollmann Markus , Preckel Benedikt , Patel Hemal , Weber Nina 
Published: June 2021

Caveolae, lipid enriched invaginations of the plasma membrane, are epicentres of cellular signal transduction. Caveolins, structural proteins localized to caveolae, have been shown to play an important role in anesthetic‐induced cardioprotection. Helium (He) postconditioning is known to reduce infarct size and induces cardioprotection. We here hypothesize that He postconditioning regulates caveolin‐1 and ‐3 (Cav‐1 and Cav‐3) in the heart. Employing coronary artery occlusion, male Wistar rats (n=8 each group) were subjected to 25 min of cardiac ischemia and reperfusion (I/R) for 5, 15 or 30 min (I/R 5/15/30), respectively. The He postconditioning groups underwent I/R plus 70% He during reperfusion (He 5/15/30 minutes, respectively). The sham group received surgical treatment without I/R (Sham). After each protocol blood and hearts were retrieved. The tissue was obtained from the area at risk (AAR) and the non‐area at risk (NAAR) and processed for Western blot analyses and qRT‐PCR. The membrane fraction (AAR) of He 15 showed increased levels of Cav‐1 (p<0.05 vs. I/R 15) and Cav‐3 (p<0.05 vs. I/R 15). Elevated levels of Cav‐3 were also found in the He 15 serum (p<0.05 vs. I/R 15). Gene expression analyses revealed decreased expression of Cav‐3 in He 15 compared to Sham in AAR (p<0.05) and NAAR (p<0.05) tissue. These data suggest that 15 min He postconditioning might induce survival pathways by regulating caveolin‐1/‐3 translocation and gene expression.This study was funded by the SCA.
GATA4‐controlled HDAC1/HDAC2‐regulated Cardiogenesis of Mesenchymal Stem Cells
Authors: Wang Meijing , Wang Lina , Yu Qing , Turrentine Mark 
Published: June 2021

Histone modifications correlate with gene expression and contribute to cell fate commitment. We have reported that inhibition of histone deacetylase1 (HDAC1) or HDAC2 enhanced histone acetylation at cardiac gene loci and promoted cardiogenesis of mesenchymal stem cells (MSC). MSC infected with cardiac transcription factor GATA4 gene have demonstrated increased myocardial differentiation, indicating the transcription machinery in guidance of cardiac cell fate. However it is unclear whether functions of transcription factors and histone modifications are interdependent in control of cardiac cell fate. We hypothesize that HDAC1/HDAC2 and GATA4 competitively bind to cardiac‐specific gene promoters, thereby governing cardiac gene expression.MethodsMSC were isolated from bone marrow of C57BL mice based on our published methods. MSC were transfected with siRNA of scramble, HDAC1 or HDAC2, or infected with retrovirus vectors (GATA4 RV/Control ‐ EGFP only; GATA4 RV ‐ EGFP+GATA4). Cardiac gene expression, histone acetylation and DNA‐binding levels of GATA4 or HDAC1/HDAC2 were analyzed at cardiac specific gene promoters by Chromatin Immunoprecipitation–qPCR and RT‐qPCR.ResultsKnock‐down of HDAC1 or HDAC2 enhanced GATA4 occupancy at promoters of cardiac α‐MHC (Myh6) and troponin T (cTnT) in MSCimagewith increased gene expression and local levels of acH3/acH4. GATA4 overexpression [figure2A] did not change nuclear protein levels of HDAC1 and HDAC2 in MSC, but limited HDAC1/HDAC2 recruitment and decreased their bindings to Myh6 and cTnT promoters [figure2B]. Notably, this decreased occupancy of HDAC1 and HDAC2 was associated with upregulated gene expression and enhanced acH3/acH4 enrichment at the tested gene loci. Our results represent initial evidence that the interplay between GATA4 and HDAC1/HDAC2 controls promoter accessibility of cardiac genes, thus directing MSC cardiac commitment.
Pulmonary Slowly Adapting Sensory Units Being More Active in Large Than in Small Airways May Result From More Sensory Receptors in the Units
Authors: Liu Jun , Song Nana , Guardiola Juan , Yu Jerry 
Published: June 2021

It has been recognized for a long time that sensory units of pulmonary slowly adapting receptors (SARs) are more active in larger airways than in small airways. However, there is no explanation for this phenomenon. Structure is the basis for function. Sensory structures observed in peripheral airways resemble those found in central airways. However, in larger airways the sensory structures are bigger and more complex. Possibly, larger structures provide greater surface area for depolarization, and thus have a lower activating threshold and/or a higher sensitivity to stretch, leading to more activities. Recently, a single sensory unit has been reported to contain multiple receptors. Therefore, sensory structures in the large airway may contain more SARs, which may contribute to high activities. To test this hypothesis, we used a double staining approach to examine receptor structures in large (trachea and bronchi) vs small (bronchioles <500μm) airways in the rabbit. We labeled airway tissues with Na+/K+‐ATPase antibodies to show all structures of the sensory unit and with myelin basic protein (MBP) antibodies to show the myelin sheath. We define an SAR as the end structure beyond MBP labeling. We found that even though the whole structure was bigger in large airways (5577±373 μm2) than in small airways (2531±345 μm2; P<0.0001), there was no difference in receptor sizes (583±23 μm2 vs 627±37 μm2; P>0.05). Furthermore, the receptor structure contains more SARs in the large airways (9.56±0.60) than the small airways (4.03±0.39; P<0.0001). Thus, we conclude that the higher activities in large sensory units may be due to a large number of receptors.(Supported by a VA Merit Review award PULM‐029‐10S)
Control of a Mechanical Ventilator Using the pre‐Bötzinger Complex
Authors: C. Howard , A. Garcia , J. Bloom , J. Ford , M. Gonzalez , E. McCuen , P. Richardson , JM. Ramirez 
Published: June 2021

Chronic mechanical respiratory support is critical for patients unable to breathe spontaneously, yet current mechanical ventilators fail to synchronize to the body's physiological needs. Ventilator asynchrony often results in ventilator induced lung injury to those on respiratory support. We are developing a patient‐triggered ventilator to provide respiratory support in a more physiologically synchronous manner than existing ventilation methods. Our system utilizes neurological activity within the brainstem, particularly in the pre‐Bötzinger complex (pre‐BötC), to control a ventilator with minimal latency between brainstem electrical activity and ventilation.In vivo experiments were performed on anesthetized mice. Extracellular recordings of the pre‐BötC neurons were made; pre‐BötC electrical activity was amplified and integrated. This integrated signal was then processed into a valve‐control signal. Constant air pressure was supplied to the valve; airway pressure (Paw) between the valve and a test lung was measured using a pressure transducer. Pre‐BötC, diaphragmatic EMG, and Paw data were visualized and recorded for analysis. System latency was determined by measuring the time between the onset of pre‐BötC inspiratory activity and the onset of resulting Paw inspiratory swings. The system was effective in using the pre‐BötC electrical activity to ventilate a test lung. The average system latency was 20 ± 10ms.Our preliminary findings demonstrate that a mechanical ventilator can be operated using the respiratory signal produced by the pre‐BötC. Further, the system operates with latency less than the delays reported for existing patient‐triggered ventilators.Funding source: SCRI
Mitochondrial Fragmentation and Mitophagy Contribute to Doxorubicin‐induced Cardiomyocyte Death
Authors: Catanzaro Michael , Kobayashi Satoru , Gerdes Martin , Liang Qiangrong 
Published: June 2021

ObjectivesDoxorubicin (DOX) is a widely used and highly effective chemotherapeutic antineoplastic agent that can cause severe cardiotoxicity. Previous studies have demonstrated that DOX‐induced cardiomyocyte (CM) death is accompanied by excessive mitochondrial (MT) fragmentation. However, it is unclear if this MT fragmentation mediates DOX‐induced cardiomyocyte damage. This study aimed to determine whether or not inhibiting MT fragmentation can reduce DOX‐induced CM death, and whether changes in MT autophagic degradation (mitophagy) are involved.MethodsH9c2 cardiac myoblast cells were transfected with siRNA targeting DRP‐1, a protein required for MT fission, before DOX administration. Changes in MT morphology and mitophagy were monitored with confocal microscopy after infection with the adenovirus encoding mitochondria‐targeting reporter MitoDsRed or MitoRosella. Propidium iodide (PI) staining was used to quantify the extent of DOX‐induced cell injury, while protein expression levels of apoptotic markers, cleaved Caspase‐3 and cleaved PARP, were measured with western blotting.ResultsMorphometric analysis demonstrated that DRP‐1 knockdown with siRNA markedly diminished DOX‐induced MT fragmentation as shown by form factor, aspect ratio, and mitochondrial size. This led to reduced CM death as shown by percentage of PI‐positive cells, caspase‐3 cleavage, and PARP cleavage. DRP‐1 knockdown also attenuated DOX‐induced mitophagy as assessed by the dual fluorescent mitophagy reporter MitoRosella.ConclusionThese results suggest that DOX‐induced cardiotoxicity may be due to excessive mitochondrial fragmentation and degradation through autophagy.
Effects of Resveratrol on Mitochondrial Autophagy in Doxorubicin Treated Cardiac Myoblast Cells
Authors: Burina Lyudmila , Kobayashi Satoru , Gerdes Martin , Liang Qiangrong 
Published: June 2021

Background and ObjectiveDoxorubicin (DOX) is a widely used chemotherapeutic agent with dose‐dependent cardiotoxic effects. It is of great clinical significance to identify a cytoprotective agent which can attenuate DOX cardiotoxicity without affecting its anti‐tumor efficacy. Resveratrol (Rev) is a plant‐derived polyphenol shown to exert cardioprotective effects in DOX‐treated cardiomyocytes, but its mechanisms of cardioprotection remain partially understood. We tested the hypothesis that Rev protects against DOX‐induced cardiomyocyte injury by inhibiting excessive degradation of mitochondria through the autophagy‐lysosome pathway (mitophagy). MethodsH9C2 cardiac myoblasts were cultured under four conditions: 0.5 uM DOX, 5 uM Rev, 5 uM Rev + 0.5 uM DOX, and Ethanol (control). Propidium Iodide (PI) staining was used to assess necrotic cell death. Western Blotting was used to measure PARP cleavage, an apoptotic marker. Mitophagy was assessed via cellular infection with Adenovirus encoding MitoRosella, a novel dual fluorescent pH sensitive mitophagy reporter. ResultsDOX induced cardiomyocyte death as measured by PI positive cell and PARP cleavage, which was associated with increased mitophagy as assessed by the MitoRosella reporter. Pre‐treatment of cells with Rev not only attenuated DOX‐induced cell death but also inhibited DOX‐induced excessive mitophagy (Fig.1 C‐D). Rev alone had no effect on mitophagy (Fig.1 A‐B).imageConclusionThe cardioprotective effect of Resveratrol is associated with a significant reduction in DOX‐induced mitophagy in cardiomyocytes, suggesting the excessive destruction of mitochondria as a potential cardiotoxic mechanism of DOX.
Krüppel‐like factor 6 protects the podocyte from mitochondrial injury under cell stress
Authors: Mallipattu Sandeep , Horne Sylvia 
Published: June 2021

The primary etiology of chronic kidney disease is a direct consequence of initial glomerular dysfunction. Podocytes (visceral glomerular epithelial cells) in normal mature kidneys are regarded as highly differentiated and quiescent cells. Krüppel‐like factors (KLFs), zinc‐finger DNA‐binding transcription factors, play a critical role in podocyte biology. Specifically, KLF6 expression was reduced in models of podocyte injury. Podocyte‐specific loss of Klf6 (Cre+ podocin Klf6flox/flox) in mice resulted in significant albuminuria and podocyte injury with adriamycin (ADR) treatment (a model of podocyte injury). ADR‐treated Cre+ podocin Klf6flox/floxmice also exhibited dysmorphic mitochondria in the podocytes and promoter analysis revealed putative binding sites for KLF6 on cytochrome c oxidase assembly gene (SCO2).KLF6 expression increased within 6 hours of ADR (0.4μg/μl) treatment in human podocytes (HP). Knockdown of KLF6 (shRNA‐KLF6) in HP reduced the mitochondrial membrane potential as compared to shRNA‐EV HP (control). ADR‐treated shRNA‐KLF6 HP increased mitochondrial fragmentation with reduced SCO2 expression and ATP levels. Also, ADR‐treated shRNA‐KLF6 increased cleaved‐caspase 3, 9, and cytosolic cytochrome c expression and decreased pro‐caspase 3 expression. These changes were restored after reintroduction of KLF6 in HP. Also, knockdown of SCO2 (shRNA‐SCO2) increased cytosolic cytochrome c and cleaved‐caspase 9 levels. Finally, immunostaining revealed a reduction in podocyte‐specific KLF6 expression in biopsies from patients with glomerular disease.These findings suggest that KLF6 is an early inducible injury response gene, critical to the maintenance of mitochondrial function and preventing the activation of the intrinsic apoptotic pathway upon cell stress.
Maternal Obesity Alters Offspring Muscle Mitochondrial Function in Nonhuman Primates
Authors: Conner Blair , Hetrik Byron , Chicco Adam , McCurdy Carrie 
Published: June 2021

Offspring of obese mothers have increased risk for early obesity and insulin resistance. Impairment in mitochondrial (MT) function may be a primary mechanism leading to insulin resistance. This study seeks to determine if maternal western‐style diet (WSD) or obesity alone alter fetal muscle MT function and if this persists at 3yrs. Adult Japanese Macaques were chronically (>2yr) fed a control (CON) or WSD. Some WSD‐induced obese dams were switched to CON at the start of pregnancy (REV). Fetal samples were collected at gestational day 130/165. Offspring carried to term were weaned to a CON or WSD after exposure to either gestational WSD (WSD/WSD;WSD/CON) or CON (CON/WSD;CON/CON). Fetal and juvenile gastrocnemius fibers were assayed for MT function in the presence of carbohydrate (CHO) or palmitate (PALM) using high‐resolution respirometry. Fetal respiratory control ratios (RCR) decreased in WSD and REV, demonstrating 24% increased uncoupling. CHO‐stimulated state 3 respiration was reduced by 20% (p<0.01) in WSD and REV, but neither were significantly decreased in PALM. In juveniles, RCR was doubled in CON/WSD vs. CON/CON, but this increase did not occur in WSD/WSD. Likewise, CHO coupling control ratio was doubled in CON/CON vs. CON/WSD (p<0.05), but not in WSD/WSD. Maternal obesity with or without WSD reduces MT function and metabolic flexibility in fetal muscle. Inflexibility persists in the postnatal period, but only when lean offspring are challenged with WSD. Our data suggest that exposure to maternal obesity alters cellular systems responsible for MT adaptation to WSD and may contribute to increased risk of metabolic disease.Funding: NIH DK090964
The LMNA Mutation R321X Associated with Dilated Cardiomyopathy Leads to Reorganization of the Endoplasmic Reticulum and Aberrant Ca2+ Signaling in HEK 293 Cells
Authors: Gerbino Andrea , Carmosino Monica , Del Vecchio Francesca , Torretta Silvia , Schena Giorgia , Procino Giuseppe , Svelto Maria 
Published: June 2021

The lamin A/C (LMNA) are nuclear intermediate filament proteins composing the nuclear lamina. Mutations in LMNA are associated with a broad range of tissue‐specific laminopathies. In particular, dilated cardiomyopathy (DCM) with conduction system disease and sudden death is frequently caused by a premature termination codon mutation in LMNA resulting in an aberrant expression of a truncated LMNA on the nuclear envelope. In this study, we used a known LMNA nonsense mutation, R321X, to gain more insight into the pathophysiological mechanisms induced by LMNA‐R321X in human embryonic kidney (HEK293) cells.Western blot analysis of homogenate from HEK293 cells transfected with LMNA‐R321X showed a 65kDa band corresponding to the truncated LMNA. Also, immunofluorescence confocal analysis demonstrated that expression of GFP‐tagged LMNA‐R321X, but not GFP‐tagged LMNA‐WT, caused (I) loss of nuclear envelope shape and integrity (II) retention of lamin A in the endoplasmic reticulum (ER) and (III) dramatic reorganization of the ER. Interestingly, LMNA‐R321X‐induced ER reorganization dramatically perturbed Ca2+ homeostasis since both cyclopiazonic acid (CPA)‐induced Ca2+ release and capacitative Ca2+ entry were perturbed in HEK293 cells loaded with the Ca2+ dye Rhod‐2.Here, we proposed for the first time that the aberrant geometry of the ER induced by the expression of truncated LMNA may potentially lead to the development of DCM, rhythm disturbances and cardiac sudden death also via perturbance of Ca2+ homeostasis.
MALIGNANT HYPERTHERMIA:ORGANON 9426 WAS EVALUATED IN 10 mhs PIGS AND 8 CONTROL PIGS
Authors: Williams Charles 
Published: June 2021

Control pigs required 109.9 ug/kg/min and MHS pigs required 72.4 ug/kg/min infusion of ORG 9426 to maintain a 90% block. It appears that ORG 9426 is only one‐third to one‐half as potent as Vecuronium in pigs. The fact that MHS pigs only required 66% of the infusion dose to maintain a 90% block suggests that there is a marked difference in the neuromuscular effect of ORG 9426 in MHS vs control pigs.A linear regression analysis of the dose response data to ORG 9426 in MHS pigs indicated that 427.033 ug/kg would be required to produce a 100% neuromuscular blockade vs 586.31 ug/kg in control pigs.Nine of the ten MHS pigs did not develop MH or show any signs of impending MH during the halothane and succinylcholine challenge at the end of the infusion period. Organon 9426 is the first muscle relaxant to offer significant protective action at a clinical dose. This suggests that there is an allosteric site on the sodium channel (acetylcholine receptor) which regulates the flow of sodium ions through the sodium channel.Organon 9426 may be therapeutically effective in an active MH case.