bluuebunny/crossref_metadata_2025_split huggingface dataset:
Chemical Inhibition of the Replication Stress Response Causes DNA Damage and Delayed Regeneration in S. mediterranea
Authors: Nguyen Lillian , Ishaq Ariana , Sheppard Taylor , Velasquez Elizabeth , Ahmed Youssef , Montes Patricia , Arroyo Jimena , Sawyer Nathaniel , Tirgar Reyhaneh , Shamoon Ushna , Akpati Lois , Nam Edward 
Published: April 2020

S. mediterranea is a planarian with extensive regenerative ability which requires substantial cell division. However, DNA replication stress occurs every cell division and must be resolved. From yeast to man, an evolutionarily conserved DNA replication stress response (RSR) is essential for life. The RSR is a signal transduction pathway regulated by Ataxia telangiectasia and Rad3‐related kinase (ATR) and Checkpoint 1 kinase (CHK1) to respond to replication stress. However, the RSR has not been established in planarian nor do we know if it functions in regeneration. We hypothesize that ATR may be essential for regeneration. Preliminary results show reduced regenerative ability in the presence of hydroxyurea (HU), a replication stress inducing agent. However, low concentrations (2mM) did not attenuate regeneration, indicating that ATR and the RSR may be present and able to overcome replication stress. To test this, we treated amputated tails with HU, ATR inhibitor (ATRi), and a combination of both. In 2mM HU, tails regenerated similarly to control. We observed only a one day delay in regeneration with ATRi alone. However, ATRi and 2mM HU in combination prevented planarian regeneration completely. In addition, replication stress was confirmed through comet assays, which quantified levels of DNA damage within each planarian experimental group. The ATRi and 2mM HU combination group exhibited the highest average comet tail moment. These synergistic effect suggests that ATR is significant in the response to replication stress during regeneration. Additionally, inhibition of CHK1, another kinase in the RSR pathway, exhibited similar tail moment values with ATRi. Future experiments will allow us to support the presence of CHK1 and its important role in resolving replication stress. Further, determining the importance of RSR genes in planarian will elucidate the conserved components and allow us to understand how ATR and the RSR contributes to the incredible regenerative abilities in planarian.Support or Funding InformationUST Committee for Student ResearchAlvarado Sanchez LabJim Jenkin for S. mediterraneaDepartment of Education HSI‐STEM grantUST Biology Smith ChairUST Biology Department
Rap1 exacerbates myocardial ischemia/reperfusion injury through activation of NFκB signaling pathway and NLRP3 inflammasome
Authors: Cai Yin , Xie Xiang , Pan Qixian , Zhi Qiqi , Woolford Michael G. , Xia Zhengyuan 
Published: April 2020

BackgroundIschemic heart disease is a leading cause of morbidity and mortality worldwide. Activation of nuclear factor kappa B (NFκB)‐mediated inflammation has been demonstrated in various models of experimental myocardial ischemia/reperfusion injury (I/RI). Repressor activator protein 1 (Rap1), an established telomere‐associated protein, is a novel modulator of NFκB‐mediated inflammatory response. However, it is unknown whether Rap1 modulates NFκB signaling in cardiomyocytes to contribute to myocardial I/RI. Therefore, the present study aimed to explore the potential pro‐inflammatory role of Rap1 in myocardial I/RI and to determine the underlying molecular mechanism.Methods and ResultsIn a mouse model of myocardial I/RI (30 minutes of left descending coronary artery ligation followed by 24 hours reperfusion), Rap1 deficiency significantly reduced myocardial infarct size and improved cardiac systolic/diastolic function (all p < 0.05, Rap1−/− I/R vs. Rap1+/+ I/R). This was associated with a reduction in NFκB activity [reduced phosphorylation, degradation of IκBα and phosphorylation of p65] and suppressed production of NFκB‐mediated pro‐inflammatory cytokines, including tumor necrosis factor α (TNFα), interleukin (IL)6 and IL1β in the post‐ischemic myocardium (all p < 0.05, Rap1−/− I/R vs. Rap1+/+ I/R). In cultured cardiac origin H9C2 cardiomyocytes, Rap1 knockdown did not significantly influence the pro‐inflammatory response in hypoxia/reoxygenation or in lipopolysaccharide‐stimulated H9C2 cells, but deletion of Rap1 significantly attenuated macrophage infiltration into the post‐ischemic myocardium of mice (p < 0.05, Rap1−/− I/R vs. Rap1+/+ I/R). Also, knockdown of Rap1 significantly suppressed NLRP3 inflammasome formation in THP‐1 macrophages in response to LPS and ATP (p < 0.05, Rap1KD vs. Rap1WT). When post‐hypoxic H9C2 cardiomyocytes were co‐cultured with mock‐ or Rap1‐siRNA transfected THP‐1 macrophages, knockdown of Rap1 in macrophages significantly attenuated macrophage‐mediated/exacerbated cardiomyocyte injury (p < 0.05, Rap1KD vs. Rap1WT).ConclusionsThese data collectively suggest that Rap1 may exacerbate myocardial I/RI through enhancing activation of NFκB signaling pathway and NLRP3 inflammasome formation, which may yield a novel therapeutic target for myocardial I/RI.Support or Funding InformationThe work was supported by the National Natural Science Foundation of China (No. 81800245) and General Research Fund (17117217M, 17123718M Research Grants Council of Hong Kong).
STAT3 decoy oligodeoxynucleotides improve end‐organ tissue injury and survival in septic mice
Authors: Matsuda Naoyuki , Imbaby Samar , Hattori Kohshi , Hattori Yuichi 
Published: April 2020

STAT3 serves as a key transcription factor in both immunity and inflammatory pathways. We examined whether in vivo introduction of STAT3 decoy oligodeoxynucleotides (ODNs) is beneficial in reducing septic end‐organ injury. Polymicrobial sepsis was induced by cecal ligation and puncture (CLP) in mice. STAT3 was rapidly activated in major end‐organ tissues following CLP, which was accompanied by activation of the upstream kinase JAK2. Transfection of STAT3 decoy ODNs significantly improved histopathological changes in lung, liver, kidney, and heart tissues. STAT3 decoy ODN transfection downregulated pro‐inflammatory cytokine/chemokine overproduction and reduced the increases in tissue and serum levels of HMGB1 in CLP mice. These beneficial effects of STAT3 decoy ODNs led to s significant survival advantage in mice after CLP. Our results indicate a detrimental role of STAT3 in the sepsis pathophysiology and the potential usefulness of STAT3 decoy ODNs for sepsis therapy.Support or Funding InformationGrants‐in‐Aid for Scientific Research from Japan Society for Promotion of Science (17K08586, 19H03757)
EP1 Receptor Antagonism as a Therapeutic Intervention Strategy in Renal Fibrosis
Authors: Kresse Jean-Claude , Tingskov Stine Julie , Jensen Michael Schou , Mutsaers Henricus A. M. , Praetorius Helle , Nørregaard Rikke 
Published: April 2020

Renal fibrosis is a hallmark of Chronic Kidney Disease (CKD), which affects 10–16% of the world’s adult population. It has previously been shown that the cyclooxygenase/prostaglandin (COX/PG) system affects the progression of renal fibrosis. The downstream elements of this system, the eicosanoid prostaglandin (EP) receptors, EP1–4, have various physiological roles in health and disease. We therefore evaluated the effect of antagonizing one of these downstream receptors for prostaglandin, the EP1 receptor, on renal fibrosis.This was accomplished with a translational approach by utilizing three models of renal fibrosis; Transforming growth factor β (TGF‐β) treated Madin‐Darby Canine Kidney (MDCK) cells, mice that underwent seven days of unilateral ureteral obstruction (UUO), as well as TGF‐β treated Human Precision Cut Kidney Slices (HPCKS). We evaluated the extent of fibrosis in these models on the gene and protein level using QPCR as well as Western blotting and immunohistochemical analysis. Moreover, we determined the corresponding effects of the EP1 agonist 17‐phenyl trinor prostaglandin E2 (17‐phenyl PGE2) and the EP1 antagonist SC‐19220 on the intracellular Ca2+ concentration in MDCK cells measured by Flou‐4‐AM.We found, that as a whole, treatment with the EP1 receptor antagonist SC‐19220 successfully ameliorated renal fibrosis in all three models. Treatment with the EP1 receptor antagonist SC‐19220 (25mg/kg per day) diminished fibrosis in mice that underwent seven days of UUO. UUO‐induced protein expression of the fibrosis markers fibronectin (FN), α Smooth Muscle Actin (αSMA) and collagen measured by western blot, qPCR and immunohistochemical staining, was lowered by SC‐19220 treatment when compared to SHAM operated mice. Adding to this, treatment of HPCKS with SC‐19220 reduced TGF‐β‐mediated fibrosis as shown by decreased collagen 1A1, FN and αSMA gene expression as well as reduced staining intensity of Sirius Red and Masson’s Trichrome stains. In MDCK cells, fibrosis induced by TGF‐β was significantly reduced when treated with SC‐19220. This was evident by lower FN protein levels and possibly mediated by hampering of TGF‐β signalling. The specificity of SC‐19220 as an antagonist of the 17‐phenyl PGE2‐induced [Ca2+]i response was determined with standard concentration response experiments.Thus, this study shows that the EP1 receptor is a promising target for the treatment of renal fibrosis. However, further investigations into the mechanism underlying the anti‐fibrotic effect of EP1 receptor antagonism are necessary. It seems though, that intracellular calcium regulation is profoundly altered by the EP1 receptor and that this may alter fibrosis dynamics.Support or Funding InformationFunding for the project was provided by the Danish Research Council.
Alterations in Heart Rate Fragmentation After Myocardial Infarction in Rats: A Novel Approach in Heart Rate Variability Analysis
Authors: Omoto Ana Carolina Mieko , Lataro Renata Maria , da Silva Thaís Marques , Salgado Helio Cesar , Silva Luiz Eduardo Virgilio , Fazan Rubens 
Published: April 2020

Heart rate variability (HRV) has been largely studied by linear and nonlinear approaches, in a variety of clinical scenarios and animal models of diseases. Recently, a new pattern of ultra‐rapid heart rate variation has been proposed and named heart rate fragmentation (HRF). This approach showed that aging and coronary disease, increase the fragmentation of heart rate fluctuations. Since HRF was only evaluated in humans, we aimed to investigate this new HRV index in a rat model of myocardial infarction (MI). For this purpose, Wistar rats (250 a 300g) were submitted to MI by permanent ligation of the left anterior descending coronary artery, or sham‐operation (control animals). At the 4th or 12th weeks after MI, or sham‐operation, animals were instrumented with a polyethylene arterial catheter for arterial pressure recordings which were carried out in freely moving rats. At the end of the protocol, cardiac function was evaluated by echocardiography using a 21 MHZ transducer (VisualSonics‐VEVO2100®). For HRF analysis, the pulse interval (PI) series was transformed into a sequence of symbols named "−1”, “0” or “1", when the difference between successive values (transitions) was negative, zero, or positive, respectively. Next, sequences of 4 consecutive symbols were classified according to the numbers of transitions. The percentage of inflection points (PIP) of PI series were also quantified. As expected, cardiac function was found reduced in rats subjected to MI. Ejection fraction was smaller 4 (28±3 vs 68±2%) and 12 weeks after MI (38±3 vs 70±3%). Similarly, fractional shortening was also smaller 4 (13±2 vs 41±2%) and 12 weeks after MI (20±2 vs 41±3%). On the other hand, PIP values were increased in rats subjected to MI at the 4th (74±2 vs 69±1%) and 12th weeks after surgery (70±2 vs 63±1%), revealing a more fragmented pattern compared to control counterparts. We also found a significant correlation between cardiac functional parameters (ejection fraction and fractional shortening) and HRF (PIP) at both 4 and 12 weeks after MI. These findings reveal that in rats, cardiac ischemia also increases HRF, reinforcing the importance of this new HRV approach as a promising tool to explore physiological and pathophysiological conditions at clinical and experimental levels.Support or Funding InformationFinancial support: CNPq (870308/1997‐1) and FAPESP (2013/20549‐7).
Beyond Binding Kinetics: Stoichiometry via SPR can identify novel binding modes, assess ligand quality and inform functional design in biopharmaceutical discovery.
Authors: DiGiammarino Enrico L. , Izeradjene Kamel , Harding Fiona , Akamatsu Yoshiko , Xu Hattie , Chervin Adam , Stone Jennifer , Wang Ningyan , Durning Sean , Pefaur Noah , Durkin Travis , Urick Andrew , Harlan John 
Published: April 2020

Biological therapeutics have seen a dramatic increase in molecular complexity and biological mechanisms. Antibody drug conjugates (ADCs) and multi‐specific formats are filling therapeutic pipelines and fundamentally changing traditional platform approaches to biologics discovery. These new entities pose unique challenges for characterization; as with traditional mAbs they are generally triaged through the discovery process by a series of functional assays including ELISA, FACS and binding kinetics however, we have implemented an additional and often underutilized SPR measure to characterize the function and quality of these entities: binding stoichiometry. Here we will discuss the special requirements for quality stoichiometry measures and show how stoichiometry can be used to 1) identify novel binding modes for a mAb that may have implications to ADC function, 2) identify signs of molecular instability, 3) aid in engineering functional biotherapeutic molecules and 4) assess simultaneous binding of analytes in multi‐specific formats. These examples will show an important measure that can be used to identify liabilities and to demonstrate function of biotherapeutic candidates.Support or Funding InformationAll authors are employees of AbbVie. The design, study conduct, and financial support for this research were provided by AbbVie. AbbVie participated in the interpretation of data, review, and approval of the publication.
Muscle Wasting in Cancer Involves Suppression of Ribosomal Production and Increased Expression of the Ribophagy Receptor NUFIP1
Authors: Kim Hyo Gun , Huot Joshua , Pin Fabrizio , Bonetto Andrea , Nader Gustavo A. 
Published: April 2020

Muscle wasting/cachexia is a major contributor of mortality and morbidity in cancer and is frequently accompanied by functional and metabolic muscle abnormalities. Muscle mass is determined by the balance between protein synthesis and degradation, yet very little is known about the mechanisms controlling the translational capacity (i.e., ribosome biogenesis) of skeletal muscle in cancer cachexia. Muscle ribosome content is mainly regulated by transcription of the ribosomal (r)DNA genes and also by degradation of ribosomes via ribophagy. In this study, we investigated whether muscle wasting in a previously described model for the study of ovarian cancer cachexia is associated with reduced rDNA transcription and ribosomal mass. Nod SCID gamma mice were injected with 1 × 107 ES‐2 human high‐grade serous ovarian cancer cells and observed for fourteen days. Gastrocnemius muscle was collected for qPCR and western blot analysis. Fourteen days of tumor bearing resulted in a 24% (P < 0.0001) loss in gastrocnemius muscle weight. Muscle wasting was associated with ~50% (P = 0.0003) reduction in ribosomal capacity and a significant suppression in rDNA transcription rates (35%, P = 0.0086). This was accounted by a significant reduction in specific rDNA loci. Factors associated with the regulation of rDNA transcription (i.e., Pol1rb, UBF, RRN3, TAF1C, PAF53) were significantly higher than control (1.5 to 4‐fold, P < 0.05). Muscle wasting was also associated with a 4‐fold increased expression (P < 0.0001) of the ribophagy receptor NUFIP1. Our findings indicate that in cancer cachexia, the anabolic capacity of skeletal muscle is diminished due to reduced ribosome production and likely increased ribosome degradation via ribophagy.Support or Funding InformationSupported by NIH grant R56AR‐073385 to GAN, The Pennsylvania State University, and The Huck Institute of the Life Sciences.
Electronic Hookah Vaping: Inflammatory Biomarkers and Biomarkers of Exposure after Acute Exposure
Authors: Dobrin Daniel , Cheng Chiao-Wei , Means Angelica , Brecht Mary-Lynn , Rezk-Hanna Mary 
Published: April 2020

Electronic (e‐) hookah vaping has increased in popularity, especially among youth and young adults. Contributing to e‐hookah’s popularity is the unsubstantiated belief that smoke is detoxified as it passes through the water‐filled basin, rendering e‐hookah as a safer alternative to combustible tobacco smoking. With combustible tobacco smoking, vascular inflammation is a key component in the development and progression of atherosclerosis. However, the comparable effects of e‐hookah vaping have not been examined to date. In light of recent outbreaks of vaping‐associated deaths and related‐injuries, it is critical that the use of vaping devices is subjected to scientific scrutiny. Accordingly, the purpose of this work was to elucidate acute effects of e‐hookah vaping on a comprehensive set of systemic vascular inflammatory biomarkers and biomarkers exposure. In 23 young healthy subjects (age 26±1 years, BMI 24.1±0.6 kg·m2, mean±SE) who regularly smoke hookah but do not smoke cigarettes, we measured heart rate, blood pressure, systemic vascular inflammatory biomarkers, including, C□ reactive protein (hsCRP), interleukin‐6 (IL‐6), fibrinogen, and tumor necrosis factor alpha (TNFα), and biomarkers of exposure, including plasma nicotine and exhaled carbon monoxide (CO) before and after a typical 30‐minute session of e‐hookah bowl vaping and, for control comparison, before and after sham smoking (n=8). All biomarkers were measured before and ≤10 minutes after the vaping session. Our results show that after e‐hookah vaping, heart rate and blood pressure increased significantly (Δ heart rate: +9±2 beats.min−1; Δ systolic blood pressure: +16±1 mm Hg, Δ diastolic blood pressure: +10±1 mmHg, p<0.001 as compared with baseline). While nicotine levels increased after vaping (+5.34±1.24 ng/ml, p=0.002), exhaled carbon monoxide levels did not change (p=ns). Notably, plasma indices of systemic vascular inflammation increased significantly (all p<0.05, except for IL‐6: p=ns). All indices were unchanged after sham smoking. Though e‐hookah users endorse marketing claims that these products are safer alternatives to combustible tobacco smoking, our data herein show that despite the absence of combustion, acute exposure to e‐hookah among young healthy adults does not elude adverse cardiovascular effects and, in fact, leads to a transient increase in vascular systemic inflammation. Our data help inform the public about potential cardiovascular disease risk of vaping and guide further studies to examine the chronic long‐term vascular effects of exposure to e‐hookah vaping.Support or Funding InformationThis work was supported by the National Institutes of Health, National Heart, Lung, and Blood Institute 1R21HL145002‐01 and the University of California, Los Angeles Clinical and Translational Science Institute grant UL1TR000124.
Molecular basis for the exploitation of nuclear mRNA export by influenza A virus
Authors: Ren Yi , Zhang Ke , Xie Yihu , Morris Andrew , Wang Zhen , Muñoz-Moreno Raquel , Wang Juan , Zhang Liang , Esparza Matthew , García-Sastre Adolfo , Schey Kevin , Fontoura Beatriz 
Published: April 2020

Influenza A virus replicates in the cell nucleus and has evolved at least two mechanisms to exploit the host nuclear mRNA export pathway. First, we show that a key influenza virulence factor NS1 blocks nuclear export of host mRNAs. We identify the direct target of NS1 as the mRNA export receptor complex, NXF1‐NXT1, which is the principal receptor mediating docking and translocation of mRNAs through the nuclear pore complex via interactions with nucleoporins. We determined the crystal structure of NS1 in complex with NXF1‐NXT1 at 3.8 Å resolution. The structure reveals that NS1 prevents binding of NXF1‐NXT1 to nucleoporins, thereby inhibiting mRNA export through the nuclear pore complex into the cytoplasm for translation. Second, packaging of influenza virus genome has been suggested to require the mRNA export factor UAP56 through interaction with the influenza NP protein, but the mechanism remains elusive. Our biochemical characterization of the NP‐UAP56 interaction suggests that UAP56 primes NP for engaging with viral RNA. Together, our studies uncover the molecular basis of how influenza A virus targets nuclear mRNA export to inhibit host gene expression and promote viral proliferation.Support or Funding InformationNIH R01 GM113874, R01 AI125524, and R35 GM133743
The chondrocranial key: Development of the sphenoid bone in primates
Authors: Mano Nanami , Wood Brody , Oladipupo Lanre , Reynolds Rebecca , Vinyard Christopher , Cray James , DeLeon Valerie , Smith Tim 
Published: April 2020

It has been hypothesized that the human sphenoid bone is uniquely truncated, which in turn contributes to a reduction of forward midfacial growth. If so, the perinatal fusion of the intrasphenoidal synchondrosis (ISS) in humans may contribute to midfacial reduction. However, there is a lack of detailed knowledge on sphenoid development of non‐human primates. In this study, orientation and direction of growth of basicranial interface with the midface of late prenatal and early postnatal sphenoid development was examined in ontogenetic samples of primates including three species of monkeys (n = 25) and four species of lemurs and bushbabies (strepsirrhines; n= 28). Micro‐computed tomographic (CT) and histological methods were used to track cross‐sectional age changes in the sphenoid bone. In monkeys (Saguinus spp.), histological findings indicated the number of proliferating chondrocytes is reduced across age leading to a reduction in absolute anteroposterior length of the proliferating zone. Preliminary data from micro‐CT reconstructions suggest that absolute length of the ISS decreases more rapidly in monkeys than in strepsirrhines. Measurements of presphenoid (PS) and basisphenoid (BS) length indicate that in strepsirrhines, these bones grow similarly to one another as cranial length increases. In contrast, in monkeys, the PS increases at a faster pace (i.e. higher linear regression line slopes) than the BS. However, unlike humans, the monkeys studied have prolonged postnatal patency of the ISS. Thus, the reduced midfacial projection in humans and these monkeys cannot be explained by the timing of ISS fusion alone. Dichotomous growth patterns of the cranial base and midface among primates suggest different patterns of regional integration of the cranium. In particular, our results suggest that in monkeys, integration of the midface is stronger with the anterior compared to the posterior portion of the sphenoid bone. In strepsirrhines by comparison, growth of the midface progressively deviates from that of the sphenoid bone over time.Support or Funding InformationNSF; grant numbers BCS‐1830894, BCS‐1830919, BCS‐0959438