bluuebunny/crossref_metadata_2025 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 Information

NIHR01HL139638, 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 Information

This 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 Information

Department 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 objective

Heat 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 Results

Serum 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.

Conclusion

Klotho deficiency causes heart failure via downregulation of Co‐Q10 levels which impair mitochondrial respiratory chain enzyme activity and induce mitophagy.

Support or Funding Information

NIH 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

Background

Type 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.

Methods

DM2‐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).

Results

Under 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.

Conclusions

In 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 Information

This 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 Information

2019 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 Information

Support 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).
Mannitol Reduces α‐Synuclein Aggregation in a Yeast Model of Parkinson’s Disease
Authors: Pacheco Alissa Mercedes
Published: April 2020

Parkinson’s Disease (PD) is an incurable, neurodegenerative disorder. This disorder is the second most common of its type and occurs by the accumulation of abnormal proteins called Lewy Bodies (LBs). LBs are found within the neurons of PD patients and trigger cell death. As a result of both damages and decreased neurons, dopamine levels decrease triggering common symptoms of the disease such as muscle stiffness, tremors, and slowed movements. Previous studies have revealed that the human protein alpha‐synuclein is one of the major components of Lewy Bodies. In the effort to better understand the relationship between both protein aggregation and cell death, a mechanism that overexpresses human alpha‐synuclein fused to GFP in the budding yeast Saccharomyces was derived. Our preliminary data suggests that the localization of the alpha synuclein protein is found in the cell membrane. Based upon other data, mannitol may alleviate the aggregation of alpha‐synuclein within the cell membrane of the yeast cells, suggesting a possible pharmacological intercession that may lower the amount of protein aggregation in PD.
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 Information

This 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)
Fluctuating Weak Magnetic Fields Induce Marked Mitophagy
Authors: Toda Takuro , Ito Mikako , Mori Kaneo , Ohno Kinji
Published: April 2020

Previous epidemiological studies have revealed that occupational exposure to extremely low frequency weak magnetic fields (ELF‐WMF) is associated with the development of neurodegenerative diseases including Alzheimer’s disease (AD) and amyotrophic lateral sclerosis (ALS). The molecular mechanism of these detrimental effects, however, remain mostly unelucidated.

We examined the effects of extremely low frequency fluctuation of weak magnetic fields (ELF‐WMF) on cultured mammalian cells. While applying ELF‐WMF, we examined the temporal profiles of expression levels of VDAC1, a mitochondrial outer membrane protein, and seven electron transport complex (ETC) proteins of NDUFS1 (ETC I), NDUFB8 (ETC I), SDHB (ETC II), UQCRFS1 (ETC III), UQCRC2 (ETC III), MTCOI (ETC IV), and ATP5A (ETC V). ELF‐WMF downregulated the amounts of these proteins at 3 h and recovered them at 12 h. Quantification of the amount of mitochondria with MitoTracker Green showed that the mitochondrial mass was decreased to 70% at 3 h and recovered at 12 h. In addition, mitophagy‐related proteins of PINK1 and LC3‐II were increased by ELF‐WMF at 1.5–2.5 h. Quantification of ETC enzymatic activities in protein homogenates revealed that ELF‐WMF exclusively suppressed the activity of ETC II in 10 min.

We report that ELF‐WMF much weaker than geomagnetic fields suppresses the enzymatic activity of ETC II, and provokes mitophagy. Mitophagy is a cellular quality‐assurance system to eliminate damaged mitochondria. Mitophagy induced by ELF‐WMF may be causally associated with the development and progression of AD and ALS. Contrarily, ELF‐WMF finely tuned to preferentially eliminate damaged mitochondria may be able to ameliorate Parkinson’s disease, in which compromised mitophagy is a cause of the disease.

Support or Funding Information

This research was supported by grants‐in‐aids from MEXT, MHLW, and AMED of Japan.
The CH2 Domain of Pseudophosphatase MK‐STYX Regulates Neurites in Neuronal Models
Authors: Zhang Ashley M. , Reed Kirstin M. , Hinton Shantá D.
Published: April 2020

Pseudoenzymes are emerging as key regulators in signal transduction cascades. Pseudophosphatases have been implicated in diseases such as Alzheimer’s, cancer, metabolic disorder, and obesity, highlighting their importance in cellular processes. The unique catalytically inactive member of the mitogen‐activated protein kinase phosphatases (MKP) family, MK‐STYX (mitogen activated kinase phosphoserine/threonine/tyrosine binding protein), is a regulator in the stress response, apoptosis, and neuronal differentiation. We previously reported that MK‐STYX increases neurite outgrowths in PC‐12 cells through the RhoA signaling pathway and these MK‐STYX‐induced neurites have post‐synaptic and pre‐synaptic properties when stained with the classical axon and dendrite markers, Tau‐1 and MAP2 (microtubule‐associated protein 2) respectively. In primary neurons, MK‐STYX causes morphological changes, such as axons and dendrites being visibly indistinguishable. Thus, it is apparent that MK‐STYX has a role in neuronal differentiation. To investigate the molecular mechanism that MK‐STYX utilizes to cause neurite formation, PC‐12 cells expressing GFP‐tagged truncated versions of MK‐STYX rhodanese (cdc 25 homology; CH2) or dual specificity phosphatase (DSP) domain and stimulated with NGF were analyzed for neurite outgrowths. Cells expressing the CH2 domain formed a significant number of neurites, whereas cells expressing the DSP domain produced no neurites. Moreover, we expressed the active form of MK‐STYX and wild type MK‐STYX in N2A cells and stimulated them with retinoic acid. Similar to our previous report, we again saw an increase in neurite outgrowths in cells expressing wild‐type MK‐STYX. In addition, we replicated expression of the truncated versions of MK‐STYX in N2A cells. Again, we observed an increase of neurites in N2A cells expressing the CH2 domain. Taken together, these data provide evidence that MK‐STYX is a regulator in neurite formation, and that the CH2 domain is key for regulation in neurite differentiation while the DSP domain may be the accessory domain. It also highlights that this unique member of the MKP subfamily potentially has a major role in neuronal signaling.
Structure and functions of the Mediator complex: A key regulator of RNA polymerase II transcription
Authors: SATO Shigeo , Tomomori-Sato Chieri , Ranjan Amol , Conaway Ronald C. , Conaway Joan W.
Published: April 2020

In eukaryotic cells from yeast to humans, the multi‐subunit Mediator complex contributes to transcriptional regulation of RNA polymerase II (Pol II) by acting as a coregulator. The Mediator regulates multiple stages of transcription by interacting with gene‐specific transcription factors, Pol II, and factors that regulate Pol II initiation and elongation. Mediator also affects the activities of factors involved in mRNA processing and chromatin regulation. Because of its central role in transcription, Mediator modulates pathways linked to cell differentiation, cell growth, and tissue development.

Metazoan Mediator is composed of over 30 subunits in organized into several modules. In metazoa, Mediator core, composed of head, middle, and tail modules, can interact with a dissociable subunit called MED26. When isolated from cells, a large fraction of MED26‐containing Mediator is associated with Pol II; however, it remains unclear whether or how MED26 contributes to the Mediator‐Pol II interaction. A second form of Mediator lacks MED26 and instead binds a dissociable kinase module containing one of two kinase‐cyclin pairs, CDK8/Cyclin C or CDK19/Cyclin C. Because kinase module interferes with binding of the Mediator core to Pol II, it was proposed that Mediator associated with kinase module might function as a repressive cofactor; however, more recent results from multiple labs supports the model that both MED26‐Mediator and kinase module‐associated Mediator contribute to gene activation.

A major focus of our research is to understand how these two forms of Mediator are involved in transcription regulation. Ongoing experiments seek to explore mechanisms that regulate Mediator‐Pol II interactions. In particular, we wish to understand (i) how Mediator recognizes Pol II and how the Mediator‐Pol II interaction is maintained, (ii) how Mediator is released from Pol II after transcription initiation, and (iii) whether and how the kinase module and MED26 contribute to each of these processes.

Support or Funding Information

The Stowers Institute for Medical ResearchThe Helen Nelson Medical Research Fund at Greater Kansas City Community Foundation
STUB Network: Statisticians and Biologists Improving Statistics Education in Introductory Biology
Authors: Keeling Elena , Bunting Jamie , Chance Beth , Roy Soma , Blank Jason , Tintle Nathan
Published: April 2020

Introductory biology courses typically incorporate data collection and analysis into laboratory assignments, and therefore teach some basic statistics. However, these curricula are generally developed without input from statisticians and are taught by instructors, often graduate students, with a range of experience using statistics but no training in statistics education. Given the importance of statistical thinking and other quantitative approaches in biology, the Statistical Thinking in Undergraduate Biology (STUB) network was established to facilitate coordination of best practices and assessment of statistical thinking in introductory biology students. As an example of the network’s benefits, we present a case study involving redesign of laboratory activities in an Introduction to Organismal Form and Function course. Changes include alignment of language with that used in statistics courses, more thorough instruction about experimental design and statistical tests, and use of an online simulation tool shown to improve understanding of statistical inference in statistics courses. These changes are supported by statistics faculty participating in the training of biology teaching assistants. An assessment in progress compares conceptual understanding and attitudes toward statistics before and after the redesigned lab activity; the assessment tool is being used throughout the STUB network, providing comparable data across institutions. This kind of cross‐disciplinary collaboration has the potential to improve statistical thinking in undergraduate biology students, better preparing them for advanced coursework and for careers in modern biology.

Support or Funding Information

NSF Research Coordination Network‐Undergraduate Biology Education (RCN‐UBE)
Electron Scavenging Not Free Radical Scavenging by Fullerene Materials Protects Against Mitochondrial Oxidative Stress in Complex Organisms.
Authors: Bourassa Daniel J. , Tulp Orien Lee , Einstein George P.
Published: April 2020

Fullerene materials are often reported to be excellent antioxidants in cells. Usually, direct free radical scavenging mechanisms, as seen in polymer and food industry research, is the proposed antioxidant mechanism. However, free radical scavenging by antioxidants in vivo is kinetically unlikely and conflicts with fullerene material’s molecular properties. Pristine fullerene materials, and many of their derivatives, are pro‐oxidant and form adducts, which are both potentially toxic mechanisms in vivo. Although they are electrophilic, and potentially oxidative molecules with an affinity for electrons, they appear to function like other non‐radical electrophilic antioxidants and stimulate enzymatic oxidative stress management and protection. We approach fullerene material’s antioxidant role from the perspective that they do not act as direct free radical scavengers. Other mechanisms have been previously proposed that are more consistent with fullerene properties, and antioxidant benefits in vivo. Here we discuss fullerene materials as electron scavenging antioxidants rather than free radical scavengers. We propose that fullerene materials scavenge excess electrons in the ETC preventing the formation of superoxide and hydroxyl radicals in the mitochondria. The scavenging of electrons would help in preventing damage to mitochondrial structures and DNA, maintaining optimum NAD+/NADH ratios, as well as in maintaining an oxidized OX/PHOS enzyme system in mitochondrial conditions resulting from excess caloric intake in the absence of cellular energy requirements and progressive mitochondrial dysfunction related to oxidative stress. Further research is needed to evaluate the utilization of fullerene materials for use in metabolic syndromes and neurodegenerative conditions complicated by progressive mitochondrial damage.

Support or Funding Information

Supported by Institutional Resources of the University of Science Arts and Technology, Montserrat, BWI, The University of Health and Humanities, BVI and the Einstein Medical Institute, Florida USA.
MiR 208a Deficiency Promotes Mitochondrial Biogenesis in the metabolic heart
Authors: Rosca Mariana Georgeta , Mekala Naveen , Kurdys Jacob G. , Vicenzi Alexis , Avramut Carmen , Ragina Neli Petrova
Published: April 2020

A high caloric regimen causes metabolic syndrome, which is a pre‐requisite for type 2 diabetes mellitus, and increases the risk for cardiovascular disease. Both metabolic syndrome and diabetes induce a common cardiac phenotype known as metabolic cardiomyopathy with an early onset as diastolic dysfunction that may progress to systolic dysfunction and congestive heart failure.

While the normal heart is able to freely switch between glucose and fatty acid (FA) oxidation, the metabolic heart becomes almost completely reliant on FA oxidation for ATP production. This energetic dysregulation is supported by increased mitochondrial metabolism, which includes an increased mitochondrial mass and function. Based on the reported cardiac specificity of the microRNA (miR) 208a, we investigated its role in bioenergetic metabolism in the metabolic heart. Lewis rats exposed to a high fat diet (HFD) exhibit obesity, systemic insulin resistance, hyperglycemia, hyperlipidemia, cardiac diastolic dysfunction, and cardiac fibrosis. Microarray studies highlighted an altered miRNA expression profile in the heart upon HFD, including a decrease in miR 208a. CRISPR deletion of the miR 208a in cultured human SV40 cardiomyocytes exposed to diabetogenic conditions (high glucose, high albumin‐bound palmitate) led to a bioenergetics profile that favors mitochondrial FA metabolism including an increase in mitochondrial biogenesis signaling, electron transport chain complexes and critical enzymes for FA beta‐oxidation. In addition, miR 208‐a deficiency prevented the switch in the myosin heavy chain isoforms by increasing myosin heavy chain alpha, thus preserving cardiac contractility. We analyzed in silico for putative miR 208a targets focusing on mitochondrial outcomes using the TargetScanHuman database (
http://www.targetscan.org/cgi‐bin/targetscan/vert_71/targetscan.cgi). We found that mitochondrial ribosomal protein 28 (involved in mitochondrial translation and generation of mitochondrial DNA‐encoded electron transport chain subunits), MINOS1 (a conserved component of mitofilin complexes required for mitochondrial function and cristae organization), and MED7 (component of the Mediator Complex that regulates the transcription by facilitating the interaction between nuclear receptors, transcriptional co‐activator and co‐repressors, and chromatic modification factors with RNA Pol II) are rescued by miR 208a deficiency in cardiomyocytes exposed to diabetogenic conditions. In summary, miR 208a regulates nuclear and mitochondrial transcription, mitochondrial cristae organization and integrity in the diabetic heart, and supports the metabolic remodeling towards increased FA oxidation. Our data suggest that miR 208a may be a therapeutic target to promote mitochondrial biogenesis in chronic diseases associated with mitochondrial defects.

Support or Funding Information

Central Michigan University Early Career Grant, AIREA American Heart Association
Feeding Patterns and Medical Diagnosis Frequency in a National Survey of Older Dogs
Authors: Hollar Regina L. , Schiefelbein Heidi M. , Stone Becky A. , MacLeay Jennifer M. , Wernimont Susan M.
Published: April 2020

Veterinarians and owners are often concerned with the nutrition of dogs, but most knowledge of real‐world pet feeding practices is anecdotal. A survey was conducted among owners of dogs aged ≥ 5 yrs at general practice veterinary clinics across the United States (2016–2017). Owners participated in a clinic visit with their dog, and demographics including age and breed were collected. Veterinarians documented the dog’s medical history and completed a physical exam including Body Fat Index (BFI) rated using a visual scale. Owners completed a nutrition survey by estimating the proportions of dry, wet, human food, treats, and other foods (including homemade petfoods) offered to their dog the prior day. Complete nutrition survey information was obtained from 992 dogs (5.0 to 20.8 yrs, median 9.4 yrs); of these 982 (99%) had complete medical histories. Dogs represented 15 states: PA (17%), CO (17%), NY (12.7%), IL (8.5%), VA (7.9%), FL (7.8%), MO (6.8%), NJ (5.0%), MI (4.6%), MD (4.5%), TX (3.3%), LA (2.5%), GA (1.5%), CT (0.6%), and CA (0.2%). In addition to mixed breeds, 115 dog breeds were reported by owners, most commonly: Labrador Retriever (13.1%), Golden Retriever (5.3%), Shih Tzu (3.9%), Other (3.7%), German Shepherd (3.7%), Dachshund (3.3%), Yorkshire Terrier (3.1%), Beagle (2.7%), Bichon Frise (2.6%) and Pug (2.4%). Giant breeds together represented 3.8% of all dogs. The 10 most common diagnoses observed in the medical history were mild/moderate dental/gum disease: 83.7%, benign tumors (including lipomas): 46.2%, overweight/obese: 34.8%, otitis (in which atopic dermatitis was ruled out): 20.3%, arthritis (elbow, stifle, back, and/or neck): 19.6%, atopic dermatitis: 15.3%, hypothyroidism: 13.1%, sebaceous cysts: 11.3%, arthritis of the hip: 10.7%, urinary tract infection: 10.0%. BFI as assessed by vets at the time of the survey ranged from 10 to 70, median 30; 69.2% dogs had a BFI of 20 or 30 while 23.5% had a BFI of 40 or more. 92.5% of dogs were offered any dry food while 72.6% of dogs were offered ≥ 90% of their intake as dry food and 19.5% of dogs were offered exclusively dry food. 23.6% of dogs were offered any wet food; 2.6% were offered ≥ 90% of their intake as wet food and only 0.7% of dogs were offered exclusively wet food. 58.8% of dogs were offered any treats, 32.0% of dogs were offered any human food, and 5.0% were offered other food, including homemade petfoods. Most owners of older dogs fed predominantly dry food and only a minority fed wet food exclusively. Treats and human food were commonly offered. The frequency of breeds and diagnoses observed in this population were generally similar to other national surveys; this analysis provides important information about feeding patterns among older dogs.

Support or Funding Information

This study was funded by Hill’s Pet Nutrition, Inc.
MSMEG_2432 of Mycobacterium smegmatis mc2155 is a dual function enzyme that exhibits DD-carboxypeptidase and β-lactamase activities
Authors: Pandey Satya Deo , Jain Diamond , Kumar Neeraj , Adhikary Anwesha , Kumar N. Ganesh , Ghosh Anindya S.
Published: April 2020

Mycobacterial peptidoglycan (PG) is an unsolved puzzle due to its complex structure and involvement of multiple enzymes in the process of its remodelling.dd-Carboxypeptidases are low molecular mass penicillin-binding proteins (LMM-PBPs) that catalyzes the cleavage of terminald-Ala of muramyl pentapeptide branches and thereby helps in the PG remodelling process. Here, we have assigned the function of a putative LMM-PBP, MSMEG_2432 ofMycobacterium smegmatis, by showing that it exhibits bothdd-CPase and β-lactamase activities. Like conventionaldd-CPase (PBP5 fromE. coli), upon ectopic complementation in a deformed seven PBP deletion mutant ofE. coli, MSMEG_2432 has manifested its ability to restore ~75 % of the cell population to their normal rod shape. Further,in vitrodd-CPase assay has confirmed its ability to release terminald-Ala from the synthetic tripeptide and the peptidoglycan mimetic pentapeptide substrates ending withd-Ala-d-Ala. Also, elevated resistance against penicillins and cephalosporins upon ectopic expression of MSMEG_2432 suggests the presence of β-lactamase activity, which is further confirmedin vitrothrough nitrocefin hydrolysis assay. Moreover, it is found apparent that D169A substitution in MSMEG_2432 influences both of itsin vivoandin vitrodd-CPase and β-lactamase activities. Thus, we infer that MSMEG_2432 is a dual function enzyme that possesses bothdd-CPase and β-lactamase activities.
Revealing variants in SARS-CoV-2 interaction domain of ACE2 and loss of function intolerance through analysis of >200,000 exomes
Authors: Cirulli Elizabeth T. , Riffle Stephen , Bolze Alexandre , Washington Nicole L.
Published: April 2020

Lay summary

Our researchers took a look at a sequence of DNA known as theACE2gene. This gene is most well known for its role in regulating blood pressure. But in recent times, it’s drawn a lot of attention from the scientific community because it may also serve as a doorway of sorts, enabling viruses like SARS-CoV-2 to infect cells. Our researchers looked at theACE2gene in more than 200,000 people, comparing their exact DNA sequences to see where there are differences among people. Variation in the DNA sequence of a gene is common and is sometimes meaningless. But other times, small changes in the DNA sequence can alter the protein that is made from that gene. In this case theACE2gene makes the ACE2 protein, which is what the SARS-CoV-2 virus interacts with. We found a lot of variation between individuals and checked to see if that variation coincided with any traits (i.e., people with variant X tend to have high blood pressure more often than people without variant X). All of the traits we looked at were non-COVID-19-related traits, meaning we haven’t asked these people anything about COVID-19 yet (this is because these DNA sequences were collected before the pandemic).

We found that there are a number of variations observed among people in a specific part of theACE2gene. These variations are expected to alter the shape or functionality of a specific part of the ACE2 protein: The part that interacts with the SARS-CoV-2 virus. We don’t yet know what the real-life significance of this variation is, but it’s possible that these variants decrease the protein’s ability to interact with the SARS-CoV-2 virus, thus decreasing the person’s likelihood of being infected. We can speculate that there will be a spectrum of vulnerability to COVID-19 among people, where some people are more vulnerable than others, and that variants in this part of theACE2gene may be one of the reasons. The research we presented here shines a light on this part of theACE2gene and may give future researchers a direction to go in as they try to figure out what makes people vulnerable to COVID-19 and similar viruses.
Improving Coronavirus (COVID-19) Diagnosis using Deep Transfer Learning
Authors: Rehman Arshia , Naz Saeeda , Khan Ahmed , Zaib Ahmad , Razzak Imran
Published: April 2020

Background

Coronavirus disease (COVID-19) is an infectious disease caused by a new virus. Exponential growth is not only threatening lives, but also impacting businesses and disrupting travel around the world.

Aim

The aim of this work is to develop an efficient diagnosis of COVID-19 disease by differentiating it from viral pneumonia, bacterial pneumonia and healthy cases using deep learning techniques.

Method

In this work, we have used pre-trained knowledge to improve the diagnostic performance using transfer learning techniques and compared the performance different CNN architectures.

Results

Evaluation results using K-fold (10) showed that we have achieved state of the art performance with overall accuracy of98.75%on the perspective of CT and X-ray cases as a whole.

Conclusion

Quantitative evaluation showed high accuracy for automatic diagnosis of COVID-19. Pre-trained deep learning models develop in this study could be used early screening of coronavirus, however it calls for extensive need to CT or X-rays dataset to develop a reliable application.
Lockdowns to Contain COVID-19 Increase Risk and Severity of Mosquito-Borne Disease Outbreaks
Authors: Jindal Akshay , Rao Shrisha
Published: April 2020

Many countries are implementing lockdown measures to slow the COVID-19 pandemic, putting more than a third of the world’s population under restrictions. The scale of such lockdowns is unprecedented, and while some effects of lockdowns are readily apparent, it is less clear what effects they may have on outbreaks of serious communicable diseases. We examine the impact of these lockdowns on outbreaks of mosquito-borne diseases. Using an agent-based model and simulations, we find that the risk and severity of such outbreaks is much greater under lockdown conditions, with the number of infected people doubling in some cases. This increase in number of cases varies by different mosquito-borne diseases, and is significantly higher for diseases spread by day-biting mosquitoes. We analysed various intervention strategies and found that during lockdowns, decentralised strategies such as insecticide-treated nets and indoor residual spraying are more effective than centralised strategies.