bluuebunny/crossref_metadata_2025_split huggingface dataset:
Twist1 in Hypoxia‐induced Pulmonary Vascular Remodeling
Authors: Mammoto Akiko , Hendee Kathryn , Mammoto Tadanori 
Published: April 2020

Remodeling of distal pulmonary arterioles (PAs) associated with accumulation of pulmonary artery smooth muscle cells (PASMCs) represents one of the major pathologic features of pulmonary hypertension (PH). We have reported that a transcription factor, Twist1 in endothelial cells (ECs) contributes to hypoxia‐induced PH. However, the mechanism by which endothelial Twist1 controls SMC accumulation to PAs remains unclear. Here we found that Twist1 overexpression increases the expression of platelet‐derived growth factor (PDGFB) in cultured human pulmonary arterial endothelial cells (HPAECs). Conditioned media collected from Twist1 overexpressing HPAECs induce PASMC migration and proliferation. Hypoxia upregulates the levels of Twist1 and PDGFB in HPAECs. When we implant fibrin gel supplemented with ECs on the mouse lung, these ECs form vascular lumen structures and hypoxia stimulates accumulation of alpha smooth muscle actin (αSMA)–positive cells to blood vessels and upregulates PDGFB expression in the gel, while Twist1 knockdown in ECs suppresses the effects. The levels of Twist1 and PDGFB are higher in PAECs isolated from idiopathic pulmonary arterial hypertension (IPAH) patients compared to those from healthy controls. IPAH patient‐derived PAECs stimulate accumulation of αSMA–positive cells to blood vessels in the implanted gel, while knockdown of Twist1 inhibits the effects. These findings suggest that endothelial Twist1‐PDGFB signaling plays a key role in SMC accumulation to PAs in PH. Modulation of Twist1‐PDGFB signaling could be an effective strategy for PH.Support or Funding InformationNIHR01HL139638, AHA18TPA34170129
Alzheimer’s disease as a condition of accelerated aging of cerebrovascular endothelial function
Authors: Hakim Md A. , Behringer Erik J. 
Published: April 2020

Currently ~5.8 million Americans have Alzheimer’s disease (AD), whereby >95% of patients are ≥65 years old. Age‐related cognitive disorders including AD are associated with impaired blood flow delivery of oxygen and nutrients throughout the brain. Cerebrovascular endothelium is central to coordinating vasoreactivity of blood vessel networks for optimal cerebral blood flow. Thus we tested the hypothesis that cerebrovascular endothelial Gq‐protein‐coupled receptor (GPCR; P2Y) and K+ channel (KCa2.3/SK3 & KCa3.1/IK1, KIR2.1) function declines during progressive age and AD pathology. Using Fura‐2 photometry (intracellular Ca2+) and sharp electrodes (membrane potential), we measured the function of endothelial tubes of posterior cerebral arteries of male and female mice (n≥5/group): C57BL/6 [young (4–6 mo), middle‐aged (12–16 mo), and old (24–28 mo)] & 3xTgAD [young, no pathology (1–2 mo), mild cognitive impairment (MCI; 4–5 mo), extracellular Aβ plaques (Aβ; 6–8 mo), and Aβ plaques + neurofibrillary tangles (AβT; 12–15 mo)]. During normal aging, P2Y function in response to ATP (100 μM) was reduced in male vs. females during old age. In contrast, SKCa/IKCa channel function in response to NS309 (0.3–1 μM) decreased in old females vs. young females & old males. Activation of KIR channels to elevated extracellular K+ (15 mM KCl) decreased with advancing age regardless of sex. For 3xTgAD animals, P2Y function was maintained throughout AD pathology in females but decreased during AβT in males. SKCa/IKCa channel function was reduced in Aβ females vs. Aβ males. Further, KIR function decreased during Aβ and AβT groups regardless of sex. Altogether, AD pathology accelerates the impact of advancing age on cerebrovascular endothelium by at least 12 mo while indicating a sex‐based contrast in declined function of GPCRs and K+ channels across males and females respectively. Modulation of endothelial K+ channel activity may optimize cerebral blood flow during aging and AD to prevent and treat neurodegenerative disease.Support or Funding InformationThis research was supported by National Institutes of Health grants R00AG047198 & R56AG062169 (EJB).
Epithelial Na+ Channel (ENaC) in Human Arteries – An Emerging Player in Hypertension
Authors: Paudel Puia , McDonald Fiona , Fronius Martin 
Published: April 2020

The epithelial sodium channel (ENaC) in the kidney plays a key role in blood pressure regulation. Recent evidence from animal models indicates the expression of ENaC in vascular cells and suggests a role in the regulation of vascular tone and hypertension. However, it is unknown if ENaC is expressed in human arteries and if ENaC contributes to hypertension. The role of vascular ENaC in human hypertension may be further complicated by the existence of a fourth ENaC subunit δ, which is not expressed in rodents.In this study we aimed to characterise the expression of ENaC subunits in human arteries and to compare the expression of ENaC subunits in arteries from both normotensive and hypertensive patients. Human internal mammary arteries (HIMA) and human aortic punches from patients undergoing coronary artery bypass graft (CABG) surgery were collected through the HeartOtago network. The patients were divided into 3 groups on the basis of their medical history and recent blood pressure measurement: 1) Normotensive 2) Uncontrolled hypertensive and 3) Controlled hypertensive. The mRNA and protein expression of ENaC (α, β, γ and δ) were analysed with qPCR and western blot techniques respectively.We report for the first time that all four ENaC subunits are expressed at mRNA and protein levels in human arteries. In HIMA of the controlled hypertensive patients δ‐ENaC mRNA and protein expression were significantly decreased compared to normotensive patients and uncontrolled hypertensive patients (P<0.05), whereas, there was no significant difference observed between the normotensive and uncontrolled hypertensive groups. However, there were no changes in α‐, β‐ and γ‐ENaC between all 3 groups. In human aortic punches, there was a significant decrease in both β‐ (p<0.05) and γ‐ENaC (p<0.01) protein expression in controlled hypertensive patients compared to uncontrolled hypertensive and normotensive patients respectively.In summary, we observed downregulation of vascular ENaC subunits in controlled hypertensive patients compared to normotensive patients and uncontrolled hypertensive patients. Overall, our data provide new links between vascular ENaC expression and hypertension in human arteries.Support or Funding InformationDepartment of Physiology Doctoral Scholarship, University of Otago
Kidney‐specific conditional knockout of Klotho causes heart failure via impairing mitochondrial function
Authors: Zhang Bo , Chen Kai , Sun Zhongjie 
Published: April 2020

Background and objectiveHeat function declines with age which ultimately leads to heart failure. In humans, aging is associated with a decrease in serum level of anti‐aging protein, Klotho. Klotho, which was originally discovered as an aging‐suppressor gene, is primarily expressed in renal tubule epithelial cells. This gene encodes a type‐I membrane protein (Klotho protein) that exists in two forms, membrane Klotho and secreted Klotho. Secreted Klotho (sKL) enters blood and may regulate the functions of cells or tissues that do not express Klotho, such as cardiomyocytes. The objective of this study is to investigate whether kidney‐specific conditional knockout of Klotho (KL‐KO) affects mitochondrial function in cardiomyocytes.Methods and ResultsSerum sKL levels were decreased and heart function was impaired in KL‐KO mice as assessed using Doppler. Mitochondrial co‐enzyme (Co‐Q10) and respiratory enzyme Complex I were downregulated in myocytes isolated from KL‐KO mice. Interestingly, treatment with Co‐Q10 rescued KL‐KO‐induced mitochondrial dysfunction and heart failure, suggesting that Klotho deficiency‐induced heart failure may be partly due to impairment in mitochondrial function. We further investigated the underlying molecular mechanism in cultured rat heart H9C2 cells. Treatment with klotho deficient medium (50% reduction in klotho) decreased total mitochondrial DNA copy number and resulted in a downregulation of Complex I expression. Mitochondrial respiratory chain function was decreased as measured by ATP generation using Seahorse. Mitochondrial oxidative phosphorylation was impaired due to klotho deficiency. Klotho‐deficient medium also enhanced mitophagy as evidenced by increased PINK1 and Parkin expression. Klotho deficiency also induced mitochondrial fission in H9C2 cells. Treatment with Co‐Q10 rescued klotho deficiency‐induced downregulation of mitochondrial respiratory chain function and ATP generation and upregulation of mitophagy activity in H9C2 cells.ConclusionKlotho deficiency causes heart failure via downregulation of Co‐Q10 levels which impair mitochondrial respiratory chain enzyme activity and induce mitophagy.Support or Funding InformationNIH R01 Grants ‐ HL122166, HL116863, AG049780 and AG062375
Effect of High Glucose on Hypoxia/Reoxygenation Injury in Mouse Diabetic Coronary Artery Endothelial Cells
Authors: Carter Jasmine S. , Riess Matthias L. 
Published: April 2020

BackgroundType 2 diabetes mellitus (DM2) remains an increasing cause of morbidity and mortality in the Western world, including coronary artery disease and myocardial infarction. In order to eventually test mechanisms of cardioprotection by different agents, we sought to develop an in‐vitro model of mouse DM2 coronary artery endothelial cells (ECs) undergoing hypoxia/reoxygenation (HR) injury under normal and high glucose concentrations. We hypothesized that high glucose exacerbates HR injury.MethodsDM2‐ECs, grown to confluency in complete media (5% fetal bovine serum and 5.5 mM glucose), were exposed to normal (5.5 mM) or high (20.5 mM) glucose concentrations for 72 hrs. They were then were subjected to normoxic (21% O2, complete media) or hypoxic (0.0125% O2, FBS‐ and glucose‐free media) conditions for 8 hrs, followed by reoxygenation in complete media for 16 hrs. To assess the extent of injury, cell (CyQUANT GR dye) and mitochondrial viability (3‐(4,5‐dimethylthiazol‐2‐yl)‐5‐(3‐carboxymethoxyphenyl)‐2‐(4‐sulfophenyl)‐2H‐tetrazolium; MTS) as well as cellular injury (lactate dehydrogenase release; LDH) were measured. Statistics: Two‐Way ANOVA followed by Tukey post‐hoc testing; alpha = 0.05 (two‐tailed).ResultsUnder both normal and high glucose conditions, HR caused a significant decrease in cell number and increase in LDH release, while MTS remained unchanged. The injury by HR under high compared to under normal glucose conditions, was not different at either outcome parameter.ConclusionsIn contrast to our hypothesis, 20.5 mM glucose did not significantly exacerbate HR‐induced cellular or mitochondrial injury and also did not lead to significantly increased injury under normoxic conditions. It is conceivable that the DM2‐ECs in our in‐vitro model perceive a concentration of 20.5 mM as closer to normal and a concentration of 5.5 mM lower than normal than would be anticipated in‐vivo. Another explanation could be that the hypoxia we chose (0.0125% O2 for 8 hrs) was not strong and/or long enough to cause a significant enough damage to be exacerbated by an additional stressor. We also did not control for differences in osmolarity between normal and high glucose experiments that might have skewed our results. More research under different conditions will be necessary to elucidate the interplay of high glucose and HR injury in DM2.Support or Funding InformationThis work was supported, in part, by institutional funds; by a Merit Review Award (I01 BX003482) from the U.S. Department of Veterans Affairs Biomedical Laboratory R&D Service; by the American Heart Association’s PAECER Program (1R25HL145330); and by the National Institute of General Medical Sciences of the National Institutes of Health (R25GM113740).
Characterization of DMXAA‐Loaded Reconstituted High‐Density Lipoprotein Nanoparticles
Authors: Dossou Akpedje Serena , Sabnis Nirupama , Lacko Andras G. 
Published: April 2020

DMXAA is a drug agonist of the stimulator of interferon genes (STING) receptor. As such, it is capable of modulating the functional phenotype of tumor‐associated macrophages (TAMs) that originate from infiltrating monocytes and tissue‐resident macrophages. TAMs can account for up to 50% of the tumor mass and are recognized as major contributors to tumorigenesis. The pro‐tumoral activity of TAMs is linked to the ability of cancer cells and other components of the tumor microenvironment (TME) to educate TAMs, inducing them to take on a tumor‐promoting (M2) phenotype. The classical phenotype of macrophages (M1) is pro‐inflammatory and can facilitate anti‐tumoral effects. The M2 phenotype, on the other hand, sustains tumor growth, immunosuppression, matrix remodeling and metastasis. Amongst the several immunotherapy strategies used to target TAMs, DMXAA has been used to reverse the phenotype of TAMs back to the anti‐tumoral M1 phenotype in murine models of cancer. In order to avoid off‐target effects, there is a need to develop delivery strategies to direct such macrophage phenotype‐modulating drugs specifically to the tumor site since macrophages are present in all vertebrate tissues, contribute to homeostasis and act as central mediators of immune response. Biocompatible nanoparticles offer a way to achieve the selective delivery of DMXAA to TAMs, and reconstituted high‐density lipoprotein type nanoparticles (rHDL Nps) are particularly suitable for such task. Previous studies have shown that rHDL Nps readily penetrate the TME and scavenger receptors mediate the intracellular delivery of the rHDL payload. Protein expression analysis showed that M2 macrophages express these scavenger receptors. For the purpose of delivering DMXAA to TAMs and achieving a phenotype reversal, rHDL Nps transporting DMXAA (rHDL‐DMXAA) were prepared via a microfluidics process and characterized via dynamic light scattering (33.9 ± 14.28 nm particle diameter size). The fast protein liquid chromatography profile of this formulation suggested a homogeneous preparation with an estimated molecular weight of particles of about 132.3 kDa. The DMXAA encapsulation efficiency which was initially about 30.4 ± 12.4 % doubled when polyethylene glycol–phosphatidylethanolamine was included in the formulation. The rHDL‐DMXAA particles displayed increased fluorescence anisotropy over the free drug, indicating that the majority of DMXAA molecules were trapped in the core of the rHDL carrier. The characteristics of the rHDL‐DMXAA such as the small size of the particle and the receptor‐mediated uptake by the target cells suggest that DMXAA will be efficiently delivered to TAMs in the TME via the rHDL Nps. Thus, the rHDL‐DMXAA formulation is likely to impact tumor progression with potential therapeutic implications.Support or Funding Information2019 UNTHSC intramural seed grant
Analysis of Acute and Chronic Inflammatory Pain‐Depressed Wheel Running in the Rat
Authors: Quintana Taylor , Serrano Aurora K , Gupta Tanisha , Kandasamy Ram 
Published: April 2020

Traditional pain‐evoked tests (e.g., hot plate and tail withdrawal tests) do not mimic the disruptive effects of pain on daily life, a primary outcome measure used for pain in humans. This mismatch may contribute to the lack of translation of analgesics from the laboratory to the clinic. To solve this problem, we have previously demonstrated that pain‐depressed home cage wheel running is an objective and clinically relevant measure of the functional consequences of chronic inflammatory pain in the rat (Kandasamy et al., 2016, J. Neurosci. Methods). In this study, we extend this approach by assessing the extent to which acute formalin‐induced inflammatory pain depresses wheel running in the rat. The formalin test is a widely used test of acute nociception where animals are monitored for pain‐like behaviors (i.e., guarding or licking the paw) approximately one hour following formalin injection into the hindpaw. Few studies have examined the functional consequences of acute pain; thus, the aim of this study was to examine the effects of formalin‐induced inflammatory pain on function as measured by home cage wheel running. Rats were housed in individual cages containing a computerized running wheel where they remained for the rest of the experiment. Rats were allowed free access to the wheel 23 hours/day for 7 days prior to the induction of hindpaw inflammation to acquire stable running levels. Wheel running during the 23 hours immediately prior to induction of inflammation was used as the baseline. Inflammation was induced with an intraplantar injection of Complete Freund’s Adjuvant (CFA; 0.1 mL) or formalin (5%, 0.05 mL) into the right hindpaw. As expected, CFA almost completely inhibited wheel running in rats in the 23 hours following administration. Mechanical withdrawal thresholds, as measured by the von Frey test, remained low across the entire testing period. In contrast, the functional effects of a single formalin injection were apparent as indicated by decreased wheel running after the first hour following injection. Wheel running was depressed in the absence of mechanical allodynia, suggesting that inflammatory pain‐induced mechanical allodynia and decreased function are independent of each other. Importantly, these results indicate that continuous monitoring of the functional consequences of pain using home cage wheel running reveal insights into changes in behavior resulting from both acute and chronic pain.Support or Funding InformationSupport for this project was provided by a 2019–20 Faculty Support Grant from the California State University Division of Academic Affairs (RK) and funds from the College of Science at California State University, East Bay (RK).
Do I Sound Funny to You? The Role of Instructor Gender and Accent on Student Learning and Evaluation in a Digital Learning Environment
Authors: Zabalaga-Haberman Maria Francisca , Vinovskis Carissa , Stratford Jennifer M. , Lee Lisa M.J. 
Published: April 2020

In academia, student evaluation of instructors is the most utilized assessment of educators’ effectiveness, which in turn, can influence faculty promotion, tenure and career trajectory. However, ample body of literature demonstrates that students’ implicit bias and stereotyped expectations can negatively impact their evaluation of instructors in the classroom and in online learning environments. Studies on gender and age bias revealed that digital resources and instructors are evaluated differently based on the voice qualities that carry different age and gender characteristic. Further, in our previous study, male voice containing ethnic characteristics expressed in different accents showed differences in student evaluations despite the consistently positive learning outcomes. In the current, IRB‐exempt study (#17‐1510), the experimental condition expanded to test students’ learning outcomes and evaluation of digital resources narrated by a female voice with different ethnic qualities. Four identical digital learning resources introducing histology, embryology and anatomy of the pituitary were narrated by a female voice actor in 4 different accents (American, Chinese, Indian, British). Professional science students who had not yet learned any aspect of pituitary gland were recruited to participate in a randomized single blind study. Participants were randomly assigned to 4 groups (A, B, C, D) and received one of the four digital resources. All students completed a pre and post‐quiz before and after tutorial viewing and a resource and instructor evaluation. Learning outcomes were assessed by pre and post‐quiz comparison using Two‐Way ANOVAs. Quantitative data from evaluations were analyzed by Two‐way ANOVAs with Tukey post hoc tests where appropriate. Internal reliability of the evaluation items was measured across 4 groups by Cronbach’s Alpha (0.88, 0.94 for digital resource and instructor, respectively).126 students completed the study (A, n=33, B, n=28 C, n=32. D, n=30). All groups performed significantly better on the post‐quiz compared to the pre‐quiz (p<0.05; partial η2 = 0.53), but the performance increase across the 4 groups was not significantly different (p>0.05) suggesting that learning occurs from the digital tutorials and that narrator accent has no effect on learning. There was no significant difference in evaluation scores for the tutorial or the instructor across the 4 groups (p>0.05). Interestingly, all 4 groups rated the tutorials higher than the instructor (p<0.05; partial η2 = 0.14), suggesting that students value the digital resources higher than the instructor narrating them. This study reveals for the first‐time, student learning and evaluation of a female accented digital instructor, which may have important implications in the increasingly diverse and digital world of education.
Drosophila, a Novel Animal Model for Investigating Mechanisms behind Sex‐related Difference in Kidney Stone Formation
Authors: Kim Man Su , Cho Youngju , Kim Minkyong 
Published: April 2020

Kidney stones, a well‐known example of diseases that show a sex‐related difference in prevalence, are estimated to affect approximately 10 % of the population. Mechanisms behind male preponderance of the stone formation remain poorly understood mainly due to the lack of effective animal models. Here we aim to develop a Drosophila nephrolithiasis model with genetic manipulations. Drosophila’s renal system is comprised of two tubules (named Malpighian tubules) that coalesce into a common ureter. These are the equivalent of the mammalian renal system tubule and ureter since many ionic transporters are conserved in the tubules between Drosophila and humans, and fly’s ureter contains highly expressed genes unique to muscular cell types, even demonstrating ureteral peristaltic activity. Interestingly, we found genetically engineered male flies produce much larger amount of stone‐like materials than that of the female counterpart, strongly suggesting that the fly stone models have the potential to serve as a translational platform in which future studies on renal stone disorders could be performed. Using this model we plan to identify signaling pathways and genes that are involved in a sex‐related difference in stone formation. We hope this research will open a gateway to developing novel treatments and preventive strategies for patients suffering from nephrolithiasis with an emphasis on personalized medicine.Support or Funding InformationThis work was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by Ministry of Science and ICT (NRF‐2018R1A2A3074889)