bluuebunny/crossref_metadata_2025 huggingface dataset:
Testing hypotheses of hybrid origins for two seashore species ofCarexsectionPhacocystis(Cyperaceae)
Authors: Nowak Michael D , Pedersen A Tiril M , Brysting Anne K , Schrøder-Nielsen Audun , Elven Reidar , Bjorå Charlotte S
Published: April 2020

Taxonomists have proposed numerous hybrid species in plants, but to gain a better understanding of the role that hybridization may play in plant diversification, such taxonomic hypotheses must be tested using genomic data. In this study, we employ ddRAD sequence data to test taxonomic hypotheses of hybrid origins in Carex salina and C. ramenskii (Carex section Phacocystis). Sequence data from multiple Norwegian and Icelandic populations of the putative hybrid and parental species were generated for hundreds of ddRAD loci. These data were used to estimate geographical structuring of genetic diversity and admixture and to explicitly test for hybrid origins using several analytical approaches. Our results indicate recurrent hybrid origins for the populations of C. salina and C. ramenskii sampled in our study and show that these populations are characterized by high interspecific heterozygosity. Our results support the idea that hybridization may indeed play an important role in the diversification of lineages of Carex and highlight the important role that clonal propagation might play in maintaining hybrid populations. Future studies focusing on a broader geographical sampling would be needed to assess if the genetic structuring in these Nordic populations reflects range-wide patterns in these hybrid lineages.
Downregulated Gene Expression Spectrum and Immune Responses Changed During the Disease Progression in Patients With COVID-19
Authors: Ouyang Yabo , Yin Jiming , Wang Wenjing , Shi Hongbo , Shi Ying , Xu Bin , Qiao Luxin , Feng Yingmei , Pang Lijun , Wei Feili , Guo Xianghua , Jin Ronghua , Chen Dexi
Published: April 2020

Background

The World Health Organization characterizes novel coronavirus disease 2019 (COVID-19), which is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), as a pandemic. Here, we investigated the clinical, cytokine levels; T-cell proportion; and related gene expression occurring in patients with COVID-19 on admission and after initial treatment.

Methods

Eleven patients diagnosed with COVID-19 with similar initial treatment regimens were enrolled in the hospital. Plasma cytokine, peripheral T cell proportions, and microfluidic quantitative polymerase chain reaction analyses for gene expression were conducted.

Results

Five patients with mild and 6 with severe disease were included. Cough and fever were the primary symptoms in the 11 COVID-19 cases. Older age, higher neutrophil count, and higher C-reactive protein levels were found in severe cases. IL-10 level significantly varied with disease progression and treatment. Decreased T-cell proportions were observed in patients with COVID-19, especially in severe cases, and all were returned to normal in patients with mild disease after initial treatment, but only CD4+ T cells returned to normal in severe cases. The number of differentially expressed genes (DEGs) increased with the disease progression, and decreased after initial treatment. All downregulated DEGs in severe cases mainly involved Th17-cell differentiation, cytokine-mediated signaling pathways, and T-cell activation. After initial treatment in severe cases, MAP2K7 and SOS1 were upregulated relative to that on admission.

Conclusions

Our findings show that a decreased T-cell proportion with downregulated gene expression related to T-cell activation and differentiation occurred in patients with severe COVID-19, which may help to provide effective treatment strategies for COVID-19.
Clofazimine, a Promising Drug for the Treatment of Babesia microti Infection in Severely Immunocompromised Hosts
Authors: Tuvshintulga Bumduuren , Vannier Edouard , Tayebwa Dickson S , Gantuya Sambuu , Sivakumar Thillaiampalam , Guswanto Azirwan , Krause Peter J , Yokoyama Naoaki , Igarashi Ikuo
Published: April 2020

Background

Persistent and relapsing babesiosis caused by Babesia microti often occurs in immunocompromised patients, and has been associated with resistance to antimicrobial agents such as atovaquone. Given the rising incidence of babesiosis in the United States, novel drugs are urgently needed. In the current study, we tested whether clofazimine (CFZ), an antibiotic used to treat leprosy and drug-resistant tuberculosis, is effective against B. microti.

Methods

Mice with severe combined immunodeficiency were infected with 107B. microti–infected erythrocytes. Parasites were detected by means of microscopic examination of Giemsa-stained blood smears or nested polymerase chain reaction. CFZ was administered orally.

Results

Uninterrupted monotherapy with CFZ curtailed the rise of parasitemia and achieved radical cure. B. microti parasites and B. microti DNA were cleared by days 10 and 50 of therapy, respectively. A 7-day administration of CFZ delayed the rise of parasitemia by 22 days. This rise was caused by B. microti isolates that did not carry mutations in the cytochrome b gene. Accordingly, a 14-day administration of CFZ was sufficient to resolve high-grade parasitemia caused by atovaquone-resistant B. microti parasites.

Conclusions

Clofazimine is effective against B. microti infection in the immunocompromised host. Additional preclinical studies are required to identify the minimal dose and dosage of CFZ for babesiosis.
Association of residual feed intake with growth performance, carcass traits, meat quality, and blood variables in native chickens
Authors: Yang Lei , Wang Xiaolong , He Tingting , Xiong Fengliang , Chen Xianzhen , Chen Xingyong , Jin Sihua , Geng Zhaoyu
Published: April 2020

Improving feed efficiency is a primary goal in poultry breeding strategies. Residual feed intake (RFI) in chickens typically calculated during the growing period is a measure of feed efficiency that is independent of the level of production. The objective of this study was to evaluate phenotypic correlations of growth performance, carcass traits, meat quality, and blood variables with RFI in growing native chickens. A total of 1,008 chickens were selected for the experiment to derive RFI. After the RFI measurement period of 42 d, 25 chickens with low RFI values, 25 chickens with medium RFI values, and 25 chickens with high RFI values were selected. The RFI was significantly positively correlated with feed conversion ratio and average daily feed intake, while it was not significantly correlated with initial body weight (BW), final BW, average daily body weight gain, and metabolic BW0.75. The abdominal fat weight and yield of high RFI group were significantly greater than those of medium and low RFI groups, and the abdominal fat yield was significantly positively correlated with RFI. Moreover, the plasma insulin-like growth factor 1 (IGF-1) content of low RFI group was significantly greater than those of high and medium RFI groups. The plasma concentrations of adrenocorticotropic hormone, triiodothyronine (T3), and cortisol of high RFI birds were significantly greater than that of low RFI birds. RFI was significantly positively correlated with plasma concentrations of T3 and cortisol, while it was significantly negatively correlated with plasma concentration of IGF-1. In addition, the serum levels of glucose and triglyceride of high RFI birds were significantly lower than that of low RFI birds. The serum low-density lipoprotein cholesterol (LDL-C) content of high RFI group was significantly greater than that of medium and low RFI groups, and it was significantly positively correlated with RFI. Our data suggested that selection of chickens with low RFI values may be beneficial to reduce fat deposition in native chickens without affecting the meat quality. Circulating IGF-1, T3, cortisol, and LDL-C concentrations can be used as indirect selection indicators of feed efficiency in native chickens. The effect of IGF-1, T3, cortisol, and LDL-C on feed efficiency of native chickens should be carefully examined and validated in future breeding programs.
Low Homeownership in Germany—a Quantitative Exploration
Authors: Kaas Leo , Kocharkov Georgi , Preugschat Edgar , Siassi Nawid
Published: April 2020

The homeownership rate in Germany is one of the lowest among advanced economies. To better understand this fact, we evaluate the role of specific housing policies that tend to discourage homeownership. In comparison to other countries with higher homeownership such as the United States, Germany has an extensive social housing sector with broad eligibility criteria, high transfer taxes when buying real estate, and no tax deductions for mortgage interest payments by owner-occupiers. We build a life-cycle model with uninsurable income and housing risks and endogenous homeownership in order to quantify the policy impact on homeownership and welfare. Adjusting all three policies has a strong impact on housing tenure choices, closing the gap in homeownership rates between Germany and the United States by about two thirds. At the same time, household welfare would be reduced by moving to a policy regime with low transfer taxes, but it would improve in the absence of social housing, in particular, when coupled with housing subsidies for low-income households.
Fever Without a Source in an Infant Due to Severe Acute Respiratory Syndrome Coronavirus-2
Authors: Kan Matthew J , Grant Lauren M C , Muña Martha A , Greenhow Tara L
Published: April 2020

A 5-week-old infant female admitted for fever without a source subsequently tested positive for severe acute respiratory syndrome coronavirus 2. She had a mild hospital course without respiratory distress. This unexpected presentation changed regional hospital screening for coronavirus disease 2019 and personal protective equipment use by medical providers who evaluate febrile infants.
On ageing star clusters using red supergiants independent of the fraction of interacting binary stars
Authors: Eldridge J J , Beasor Emma R , Britavskiy N
Published: April 2020

We use the Binary Population and Spectral Synthesis models to test the recent suggestion that red supergiants can provide an accurate age estimate of a coeval stellar population that is unaffected by interacting binary stars. Ages are estimated by using both the minimum luminosity of red supergiants and the mean luminosity of red supergiants in a cluster. We test these methods on a number of observed star clusters and find our results in agreement with previous estimates. Importantly, we find the difference between the ages derived from stellar population models with and without a realistic population of interacting binary stars is only a few hundred thousand years at most. We find that the mean luminosity of red supergiants in a cluster is the best method to determine the age of a cluster because it is based on the entire red supergiant population rather than using only the least luminous red supergiant.
A critical role of telomere chromatin compaction in ALT tumor cell growth
Authors: Shi Guang , Hu Yang , Zhu Xing , Jiang Yuanling , Pang Junjie , Wang Chuanle , Huang Wenjun , Zhao Yong , Ma Wenbin , Liu Dan , Huang Junjiu , Songyang Zhou
Published: April 2020

ALT tumor cells often contain abundant DNA damage foci at telomeres and rely on the alternative lengthening of telomeres (ALT) mechanism to maintain their telomeres. How the telomere chromatin is regulated and maintained in these cells remains largely unknown. In this study, we present evidence that heterochromatin protein 1 binding protein 3 (HP1BP3) can localize to telomeres and is particularly enriched on telomeres in ALT cells. HP1BP3 inhibition led to preferential growth inhibition of ALT cells, which was accompanied by telomere chromatin decompaction, increased presence of C-circles, more pronounced ALT-associated phenotypes and elongated telomeres. Furthermore, HP1BP3 appeared to participate in regulating telomere histone H3K9me3 epigenetic marks. Taken together, our data suggest that HP1BP3 functions on telomeres to maintain telomere chromatin and represents a novel target for inhibiting ALT cancer cells.
Regulation of alternative polyadenylation in the yeast Saccharomyces cerevisiae by histone H3K4 and H3K36 methyltransferases
Authors: Kaczmarek Michaels Katarzyna , Mohd Mostafa Salwa , Ruiz Capella Julia , Moore Claire L
Published: April 2020

Adjusting DNA structure via epigenetic modifications, and altering polyadenylation (pA) sites at which precursor mRNA is cleaved and polyadenylated, allows cells to quickly respond to environmental stress. Since polyadenylation occurs co-transcriptionally, and specific patterns of nucleosome positioning and chromatin modifications correlate with pA site usage, epigenetic factors potentially affect alternative polyadenylation (APA). We report that the histone H3K4 methyltransferase Set1, and the histone H3K36 methyltransferase Set2, control choice of pA site in Saccharomyces cerevisiae, a powerful model for studying evolutionarily conserved eukaryotic processes. Deletion of SET1 or SET2 causes an increase in serine-2 phosphorylation within the C-terminal domain of RNA polymerase II (RNAP II) and in the recruitment of the cleavage/polyadenylation complex, both of which could cause the observed switch in pA site usage. Chemical inhibition of TOR signaling, which causes nutritional stress, results in Set1- and Set2-dependent APA. In addition, Set1 and Set2 decrease efficiency of using single pA sites, and control nucleosome occupancy around pA sites. Overall, our study suggests that the methyltransferases Set1 and Set2 regulate APA induced by nutritional stress, affect the RNAP II C-terminal domain phosphorylation at Ser2, and control recruitment of the 3′ end processing machinery to the vicinity of pA sites.
A splice site-sensing conformational switch in U2AF2 is modulated by U2AF1 and its recurrent myelodysplasia-associated mutation
Authors: Warnasooriya Chandani , Feeney Callen F , Laird Kholiswa M , Ermolenko Dmitri N , Kielkopf Clara L
Published: April 2020

An essential heterodimer of the U2AF1 and U2AF2 pre-mRNA splicing factors nucleates spliceosome assembly at polypyrimidine (Py) signals preceding the major class of 3′ splice sites. U2AF1 frequently acquires an S34F-encoding mutation among patients with myelodysplastic syndromes (MDS). The influence of the U2AF1 subunit and its S34F mutation on the U2AF2 conformations remains unknown. Here, we employ single molecule Förster resonance energy transfer (FRET) to determine the influence of wild-type or S34F-substituted U2AF1 on the conformational dynamics of U2AF2 and its splice site RNA complexes. In the absence of RNA, the U2AF1 subunit stabilizes a high FRET value, which by structure-guided mutagenesis corresponds to a closed conformation of the tandem U2AF2 RNA recognition motifs (RRMs). When the U2AF heterodimer is bound to a strong, uridine-rich splice site, U2AF2 switches to a lower FRET value characteristic of an open, side-by-side arrangement of the RRMs. Remarkably, the U2AF heterodimer binds weak, uridine-poor Py tracts as a mixture of closed and open U2AF2 conformations, which are modulated by the S34F mutation. Shifts between open and closed U2AF2 may underlie U2AF1-dependent splicing of degenerate Py tracts and contribute to a subset of S34F-dysregulated splicing events in MDS patients.
Reciprocal regulation of hnRNP C and CELF2 through translation and transcription tunes splicing activity in T cells
Authors: Mallory Michael J , McClory Sean P , Chatrikhi Rakesh , Gazzara Matthew R , Ontiveros Robert J , Lynch Kristen W
Published: April 2020

RNA binding proteins (RBPs) frequently regulate the expression of other RBPs in mammalian cells. Such cross-regulation has been proposed to be important to control networks of coordinated gene expression; however, much remains to be understood about how such networks of cross-regulation are established and what the functional consequence is of coordinated or reciprocal expression of RBPs. Here we demonstrate that the RBPs CELF2 and hnRNP C regulate the expression of each other, such that depletion of one results in reduced expression of the other. Specifically, we show that loss of hnRNP C reduces the transcription of CELF2 mRNA, while loss of CELF2 results in decreased efficiency of hnRNP C translation. We further demonstrate that this reciprocal regulation serves to fine tune the splicing patterns of many downstream target genes. Together, this work reveals new activities of hnRNP C and CELF2, provides insight into a previously unrecognized gene regulatory network, and demonstrates how cross-regulation of RBPs functions to shape the cellular transcriptome.
Encoding multiple digital DNA signals in a single analog channel
Authors: Yan Yan Helen , Zhang David Yu , Wu Lucia R
Published: April 2020

For many analytic and biomedical applications, the presence of an analyte above or below a critical concentration is more informative for decision making than the actual concentration value. Straightforward analog-to-digital signal conversion does not take full advantage of the precision and dynamic range of modern sensors. Here, we present and experimentally demonstrate an analog-to-multiple-digital signal conversion, reporting digital signals that indicate whether the concentrations of specific DNA sequences exceed respective threshold values. These threshold values can be individually programmed for each target sequence. Experimentally, we showed representation of four DNA targets’ information in a single fluorescence channel.
Acute cognitive effects of the hypocretin receptor antagonist almorexant relative to zolpidem and placebo: a randomized clinical trial
Authors: Neylan Thomas C , Richards Anne , Metzler Thomas J , Ruoff Leslie M , Varbel Jonathan , O’Donovan Aoife , Sivasubramanian Melinda , Motraghi Terri , Hlavin Jennifer , Batki Steven L , Inslicht Sabra S , Samuelson Kristin , Morairty Stephen R , Kilduff Thomas S
Published: April 2020

Study Objectives

Hypnotic medications can adversely affect behavior during unanticipated awakenings during the night. Animals treated with the hypocretin (Hcrt) receptor antagonist almorexant (ALM) have less acute cognitive impairment compared to the GABAA receptor modulator zolpidem (ZOL). This study aimed to determine whether ALM produces less acute cognitive impairment than ZOL in human subjects.

Methods

Healthy, young adult, unmedicated male and female subjects participated in a controlled trial of a single dose of ALM 100 mg (N = 48), ALM 200 mg (N = 53), ZOL 10 mg (N = 49), and placebo (PBO, N = 52).

Results

ZOL and both doses of ALM produced similar levels of subjective sleepiness and impaired the ability of subjects to remain awake in a dark, low-stimulus setting relative to PBO. For most cognitive measures, performance under ZOL was significantly worse than ALM or PBO. For tasks involving verbal memory or visual-motor coordination, ZOL impaired performance, whereas the two doses of ALM were no different than PBO. For tasks involving higher-order executive function, ZOL produced impairment in processing speed and inhibitory control, whereas the two doses of ALM were no different than PBO. Performance decrements for ALM were less than ZOL but greater than PBO for some reaction time measures.

Conclusions

The data provide support for the hypothesis that Hcrt receptor antagonists produce less functional impairment than a benzodiazepine receptor agonist (BzRA). These observations are particularly relevant to patients treated with sedative-hypnotics who are at elevated risk for falls and other untoward events during the intended hours for sleep.
Help-Seeking Behaviors as Cultural Capital: Cultural Guides and the Transition from High School to College among Low-Income First Generation Students
Authors: Richards Bedelia Nicola
Published: April 2020

This article argues that educational institutions can transmit cultural capital in the form of help-seeking dispositions (feeling empowered to ask for and receive help) and specialized knowledge (information about how to gain access to resources) that can positively impact students’ academic outcomes. Additionally, this article questions the perception that educational institutions function primarily as agents of social reproduction, by showing that institutional agents such as high school teachers and administrators can function as “cultural guides” to bolster students’ opportunities for social mobility. Drawing on interviews with graduates of King and Chavez, two early college high schools which target low-income, first-generation college students, I find that King graduates were more strategic help-seekers and were more likely to use campus-based resources than their counterparts at Chavez, in part because their school’s curriculum explicitly and systematically taught this skill. This article challenges the perception that teachers and administrators function exclusively as gatekeepers in educational institutions. Instead, the data presented show that these institutional agents can also function as “cultural guides” who transmit cultural capital in the form of help-seeking values and behaviors to students from economically marginalized communities; promoting their upward mobility.
The Dynamics of Bird Diversity in the New World
Authors: Machac Antonin
Published: April 2020

Three prominent explanations have been proposed to explain the dramatic differences in species richness across regions and elevations, (i) time for speciation, (ii) diversification rates, and (iii) ecological limits. But the relative importance of these explanations and, especially, their interplay and possible synthesis remain largely elusive. Integrating diversification analyses, null models, and geographic information systems, I study avian richness across regions and elevations of the New World. My results reveal that even though the three explanations are differentially important (with ecological limits playing the dominant role), each contributes uniquely to the formation of richness gradients. Further, my results reveal the likely interplay between the explanations. They indicate that ecological limits hinder the diversification process, such that the accumulation of species within a region gradually slows down over time. Yet, it does not seem to converge toward a hard ceiling on regional richness. Instead, species-rich regions show suppressed, but continued, diversification, coupled with signatures of possible competition (esp. Neotropical lowlands). Conversely, species-poor, newly-colonized regions show fast diversification and weak to no signs of competition (esp. Nearctic highlands). These results held across five families of birds, across grid cells, biomes, and elevations. Together, my findings begin to illuminate the rich, yet highly consistent, interplay of the mechanisms that together shape richness gradients in the New World, including the most species-rich biodiversity hotspots on the planet, the Andes and the Amazon. [Biogeography; community; competition; macroevolution; phylogenetics; richness gradient.]
S. mediterranea Ataxia telangiectasia and Rad3‐related kinase (SmedATR) May be Required to Prevent DNA Replication Stress
Authors: Ishaq Ariana , Nguyen Lillian , Sheppard Taylor , Velasquez Elizabeth , Ahmed Youssef , Montes Patricia , Arroyo Jimena , Tirgar Reyehana , Shamoon Ushna , Akapti Lois , Nam Edward
Published: April 2020

DNA replication is an important mechanism involved in cellular processes like reproduction, repair, and regeneration. S. mediterranea, a planarian with an amazing regenerative ability, goes through continuous rounds of cell division. Consequently, DNA replication stress occurs with each cell division and must be resolved. From yeast to man, The DNA replication stress response (RSR) is evolutionarily conserved and necessary for life among organisms. 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, including DNA damage. However, the RSR has not yet been established in the planarian and its involvement in regeneration is currently unknown. We hypothesize that ATR may be essential in replication by preventing and resolving DNA damage. Regeneration experiments were conducted and results indicated that the regenerative ability of planaria were reduced in the presence of hydroxyurea (HU), a replication stress inducing agent. Low HU concentrations (2mM) had similar phenotypic results to the control which suggests that ATR and the RSR may be present in this low dosage to overcome the replication stress. However, when treated with a combination of 2mM HU and ATR inhibitor (ATRi), planarian regeneration was severely hindered. To confirm replication stress shown phenotypically in the regeneration experiments, comet assays were performed to quantify the levels of DNA damage in each experimental group. The ATRi and 2mM HU combination group exhibited the highest average comet tail moment, a parameter used to measure the amounts of fragmented DNA within each planarian cell. The synergistic effects of ATR in combination with HU suggest 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 as ATRi. Future experiments will allow us to support the presence of CHK1 and its important role in resolving replication stress. 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 Information

UST Committee for Student Research Alvarado Sanchez Lab, Stowers Institute for Medical Research Jim Jenkin for S. mediterranea Department of Education HSI‐STEM grant UST Biology Smith Chair UST Biology Department
Role of PPAR Pathway in Atrial Fibrillation Associated with Heart Valvular Disease: Transcriptomics and Proteomics in the Human Atrial Tissue
Authors: Chen Huan-Xin , Jiang Yi-Yao , Li Ming-Yang , Hou Hai-Tao , Wang Jun , Yang Qin , He Guo-Wei
Published: April 2020

Objective

Atrial fibrillation (AF) is one of the most common cardiac arrhythmias. Previous studies have shown that electrical, contractile, and structural remodeling play the key role in the onset and maintenance of AF. Heart valvular disease (HVD) is associated with an increased risk of thromboembolic events, mainly in patients with AF. However, the molecular mechanism of AF in HVD remains unrevealed, although there was an attempt to discover the plasma biomarkers in HVD.

Methods

Human atrial tissues from patients with HVD in persistent AF preoperatively for at least 6 months or remaining sinus rhythm (as control) undergoing heart valve replacement surgery were studied by combined transcriptomics and proteomics. Owing to the fact that there are maximal 8 Isobaric tags in proteomics analysis by iTRAQ technology, 8 tissue samples were allocated, including left atrial tissues from 3 AF patients (AFLA) and right atrial tissues (3 AFRA and 2 SRRA) from 5 patients. The analysis of transcriptomics and proteomics were from the same samples. Big data obtained from omics study were analyzed by bioinformatics tools. The fold changes of >1.2 (or <0.8) and P value < 0.05 were considered as significant.

Result

Hierarchical clustering analysis revealed that the genomic expressions of three groups have differences in transcriptomics. Pairwise comparison was performed and differentially expressed genes were identified, including 193 genes up‐regulated and 279 genes down‐regulated. Heat map from differentially expressed proteins in proteomics analysis indicates that there are significant differences in patients with or without AF and between the left and right atrium. Based on Gene ontology (GO) function and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis, we found that the expression of genes and proteins associated with PPARα, β/δ, γ was altered in omics study in AF patients. Genes/proteins, such as FATCD36, SCD‐1, FABP, ADIPO, APOA1, APOA2, FATP, FADS2, ACBP, CPT‐1, aP2, CAP, and etc., are included in the PPAR pathway. These genes/proteins may be developed as potential biomarkers for disease pathogenesis and progress in AF.

Conclusion

Our study provides an integrative analysis of transcriptomics and proteomics in human atrial tissues of AF‐associated HVD patients and reveals that PPAR signaling pathway plays an important role in pathogenesis of AF. Some of differential proteins may become biomarkers and provide new diagnostic and therapeutic methods for AF in the future.

Support or Funding Information

This work was supported by the National Natural Science Foundation of China [81870288 & 81870227]; the Non‐profit Central Research Institute Fund of Chinese Academy of Medical Sciences [2019XK310001& 2018TX31002]; Tianjin Science and Technology Committee[18PTZWHZ00060];Binhai New Area Health Bureau (2018BWKZ005)
Anatomical Variation of Tendinous Interconnection between Flexor Hallucis Longus and Flexor Digitorum Longus Tendon and Its Location regarding Master Knot of Henry
Authors: Wan-ae-loh Perin , Dangintawat Pimpimol , Huanmanop Thanasil , Agthong Sithiporn , Chentanez Vilai
Published: April 2020

Tendinous interconnections between flexor hallucis longus (FHL) and flexor digitorum longus (FDL) have functional importance in toe movement and act as a natural tenodesis after harvesting FHL tendon proximal to master knot of Henry (MKH). This anatomical study aimed to clarify the type, location and distribution to lesser toes of tendinous interconnection between FHL and FDL tendons in 102 embalmed and 62 soft cadaveric feet. According to the classification of Beger et al., three types of interconnection (type I, II, V) were found in 85.4 %, 0.6%, and 7.9% of specimen, respectively. In addition, a new type of connection (6.1%) in which is FHL tendon bifurcated into one tendon to the first toe and the other tendon fused with FDL tendon. The tendinous interconnection was located either proximal (−) or distal (+) to MKH. The mean distance from MKH in type I was1.38±10.40 mm (from −59.47 to 20.52 mm). The proximal and distal interconnection slips in type V were located at 6.61±4.69 mm (from 0.00 to 12.47mm) and 12.95±3.48mm (from 7.05 to 16.13 mm) from MKH. In the new type, the interconnection slip was located at −6.59±8.93 mm (from −20.81 to 5.48 mm) from MKH. The distribution of tendinous slip to lesser toes was determined by pulling the FHL tendon and observing the lesser toes’ movement. According to the classification of Plaass et al., the prevalence of distribution of tendinous slip to lesser toes in type a, b, c and d was 19.5%, 67.7%, 11.0%, and 1.8%, respectively. Knowledge of the tendinous interconnection and its location are important for enhancing the clinical efficacy of FHL tendon transfer and minimizing of the functional loss of toes in post‐operative period.

Support or Funding Information

1. The ๑ ๐ ๐ th Anniversary Chulalongkorn University Fund for Doctoral Scholarship from the Graduate School, Chulalongkorn University 2. Overseas Academic Presentation Scholarship for Graduate Students from the Graduate School, Chulalongkorn University
Role of Mineralocorticoid receptor (MR) and NEDD4‐2 in the regulation of ENaC and ROMK in the Distal Convoluted Tubule (DCT) and Cortical Collecting Duct (CCD)
Authors: Zhang Dandan , Wu Peng , Duan Xin-Peng , Lin Dao-Hong , Staub Olivier , Ellison David H. , Wang Wen-Hui
Published: April 2020

Background

ENaC and ROMK (Kir1.1) are expressed in the apical membrane of aldosterone‐sensitive distal nephron (ASDN). Aldosterone has been shown to play an important role in the regulation of ENaC and ROMK expression in ASDN. Also, NEDD4‐2 is an E3 ubiquitin ligase expressed in the ASDN and NEDD4‐2 has been shown to play a role in mediating the effect of aldosterone on ENaC. The aims of the present study are:1) To examine whether MR plays a similar role in regulating ENaC and ROMK in the DCT2 and CCD; 2) To examine whether NEDD4‐2 regulates ROMK channels in ASDN.

Methods

The whole‐cell recording technique has been used to measure the amiloride‐sensitive Na currents (ENaC) at −60 mV and TPNQ‐sensitive K currents (ROMK) at −40 mV in the DCT2/early connecting tubule (CNT) and in the CCD of tubule‐specific MR‐KO, NEDD4‐2 KO and corresponding WT mice on a normal rodent diet (0.4% Na and 0.9% K).

Results

Deletion of MR receptor decreased ENaC currents from10.2 pA/pf to 6.3 pA/pf (at −60 mV) in the DCT2/CNT but it largely abolished ENaC currents in the CCD (from 4.9 pA/pf to 0.7 pA/pf). In contrast, the deletion of MR had no significant effect on ROMK currents in the DCT2 since TPNQ‐sensitive K currents were the same between WT and Ks‐MR‐KO mice (WT, 51.0 pA/pf; Ks‐MR‐KO, 50.0 pA/pf at −40 mV). However, the ROMK currents of the CCD were significantly smaller in MR‐KO (22.1 pA/pf) than in WT (33.8 pA/pf), suggesting that MR plays a role in regulating ROMK only in the CCD but not in the DCT2/CNT. Deletion of NEDD4‐2 increased amiloride sensitive Na currents from 10 pA/pf to 13 pA/pf in the DCT2/CNT but it robustly increased ENaC currents from 5.1 pA/pf to 15 pA/pf in the CCD, suggesting that NEDD4‐2 plays a bigger role in regulating ENaC in the CCD than in the DCT2/CNT. Deletion of NEDD4‐2 inhibited rather than stimulated ROMK channel activity in both DCT2/CNT and in the CCD. TPNQ‐sensitive K currents were decreased from 46 pA/pf (WT) to 24.6 pA/pf (NEDD4‐2 KO) in the DCT2/CNT and from 34 pA/pf (WT) to 23.6 pA/pf (NEDD4‐2) in the CCD.

Conclusion

MR plays a key role in the regulation of ENaC in the CCD but to a less degree in the DCT2/CNT. ROMK channel activity is modestly regulated by MR in the CCD but not in the DCT2/CNT. NEDD4‐2 plays a role in the down‐regulation of ENaC activity in the ASDN, especially in the CCD, but it may not directly regulate ROMK.

Support or Funding Information

DK54983
Methionine Aminopeptidase Inhibitors in Mammalian Cells
Authors: Condic Natalia , Ramtahal Cassandra , Boukari Jamila , Croes Alex , Nguyen Calvin , Alvarez Melissa , Olaleye Omonike , Rosell Rosemarie
Published: April 2020

Mycobacterium tuberculosis (Mtb) is the leading cause of mortality from an infectious disease, worldwide. Mtb benefits from an HIV‐weakened immune system, and leads to a statistically increased risk of HIV/TB co‐infection. The rise of multi‐drug resistant Mtb strains makes treatment difficult, thus a novel drug may be required to eliminate Mtb infection. Our collaborators at Texas Southern University have identified novel bacterial methionine aminopeptidase (MtMetAP1) inhibitors. Genetic knockout studies support the lethality of the deletion of MtMetAP1 in Mtb. Further studies support the existence of an ortholog of MtMetAP1 in Homo sapiens (HsMetAP1). In addition, humans have several paralogs of MetAP, which perform similar essential functions to MetAP1. Although these novel inhibitors are effective against Mtb, the cytotoxicity in mammalian cells has not been established. To address this, we tested a MtMetAP1 inhibitor (UST‐001) on H1299 human lung carcinoma cells and Mlg‐2908 mouse lung fibroblast cells. Using flow cytometry and a WST‐1 assay to assess cell viability, we determined the LC50 to be 1.652μM in the H1299 lung carcinoma cell line. The consistent non‐significance of our data supports our hypothesis regarding the non‐fatal nature of this drug in a human cell line, as there were no significant differences between controls and experimental conditions. Initial results from WST‐1 assays with Mlg‐2908 cells indicate that the LC50 for Mlg‐2908 is between 5 and 10μM, higher than that of H1299. Further studies using flow cytometry analysis are required to solidify this comparison, while another apoptotic assay may also be beneficial to determine an exact LC50 and ultimately the efficacy of this drug.

Support or Funding Information

U.S. DOE, Hispanic‐Serving Institutions, STEM Articulation Grant P031C110128, the Cullen‐Smith Foundation, and the UST Committee for Student Research for their financial support
Down Regulation of HMGB1‐RAGE pathway by Ethyl Pyruvate
Authors: Mun Seok-Jun , Yang Chul-Su
Published: April 2020

HMGB1 (high Mobility Group Box 1) protein is released by nuclear after that binds to DNA. HMGB1 can also be secreted from cells, it can bind receptor for advanced glycation end products (RAGE) that inflammatory receptor. Interaction between HMGB1 and RAGE causes upregulation of NF‐kB that leads to increased production of cytokines. Ethyl pyruvate (EP) is the ethyl ester of pyruvic acid. In recent research, EP has shown HMGB1 inhibitory effecting in many inflammation‐related diseases through pathway inhibition. In this study, we measured that expression of HMGB1 mRNA and proteins stimulated by LPS in presence of ethyl pyruvate (EP) or other inflammatory stimulants was measured as RT‐qPCR and immunoblotting analysis in BMDMs. Furthermore, levels of cytokine in the supernatant of BMDM stimulated by LPS in presence of EP or other inflammatory stimulants or mouse serum were measured by ELISA. Here in we found that EP inhibits HMGB1 pathway leading to reduced RAGE expression and NF‐κB activation. Moreover, we demonstrated EP reduced HMGB1 in serum levels of mice. Our results suggested that EP is effective inhibitors of HMGB1/RAGE signaling pathway, offering a novel potential therapeutic approach to patients and HMGB1 has been proposed as a target for inflammatory disease.

Support or Funding Information

ACKNOWLEDGEMENTS

This work was supported by the NRF grant funded by the Korea government (MSIP) 2019R1I1A2A01064237.
MMP9 inhibition increases autophagic flux in chronic heart failure
Authors: Nandi Shyam S. , Katsurada Kenichi , Sharma Neeru M. , Anderson Daniel R. , Mahata Sushil K. , Patel Kaushik P.
Published: April 2020

An increased matrix metalloprotease 9 (MMP9) during post‐myocardial infarction (post‐MI) exacerbates ischemia‐induced chronic heart failure (CHF). MMP9 abrogation is cardioprotective during post‐MI remodeling, however, whether MMP9 abrogation protects the heart via upregulation of autophagic activity is unknown. This study aimed to determine whether the MMP9 inhibition upregulates cardiac autophagic flux during post‐MI CHF in rats. Sprague‐Dawley rats underwent either Sham or coronary artery ligation, 6–8 weeks prior to being treated with MMP9‐inhibitor for 7 days, followed by cardiac autophagic flux measurement using lysosomal inhibitor BafilomycinA1. Further, autophagic flux was measured in vitro by treating H9c2 cardiomyocytes with two independent pharmacological MMP9 inhibitors, Salvianolic‐Acid‐B (SalB) or MMP9‐inhibitor‐I and CRISPR/cas9–mediated MMP9 genetic ablation. CHF rats showed cardiac infarct, significantly increased left‐ventricular end diastolic pressure (LVEDP), and increased MMP9 activity and fibrosis in the peri‐infarct areas of left‐ventricular myocardium. The autophagic markers LC3B‐II and p62 measurement with lysosomal inhibition showed decreased autophagic activity in the peri‐infarct myocardium. Treatment with SalB for 7 days in CHF rats decreased MMP9 activity, cardiac fibrosis, and increased autophagic flux in the peri‐infarct myocardium. As an in vitro corollary study, measurement of autophagic flux in H9c2 cardiomyocytes showed that pharmacological inhibition or genetic ablation of MMP9 upregulates autophagic flux. These data are consistent with our observations that MMP9 inhibition upregulates autophagic flux in the heart of rat with CHF. In conclusion, the results in this study suggest that the beneficial outcome of MMP9 inhibition on pathological cardiac remodeling is in part mediated by improved autophagic flux.

Support or Funding Information

This work was supported by American Heart Association Career Development Grant Award 19CDA34490029 to S.S. Nandi, and National Institutes of Health Grants R01‐DK‐114663, P01‐HL‐62222, and endowed McIntyre Professorship to K.P. Patel.
A Mixed Reality Application To Visualize Amino Acids
Authors: Srinivasan Rekha , Ali Ridaa
Published: April 2020

This study examines the benefit of using mixed reality to visualize amino acid molecules for students in introductory biochemistry courses at the undergraduate and graduate level. A Novel Microsoft HoloLens application that tests understanding of amino acid structures was developed. The application was made accessible to students by making it compatible with multiple platforms in addition to Universal Windows Platform; these platforms include Android and iOS as well as PC, Mac, and Linux stand‐alone. This was done using Unity3D with coding in C#. The success of application development and implementation in the classroom was tested by students of Biochemistry. The results of student attitude survey regarding the ease and benefit of the application on mixed reality, and any other platforms they choose to use it on, is presented herein

Support or Funding Information

PRISE, WISER, Flora Stone Mather Center for Women, Case Western Reserve University
Melatonin Mitigates Ovarian Toxicity In Cannabis‐treated Female Wistar Rats
Authors: Olayaki Luqman Aribidesi , Oluwasola Amuda
Published: April 2020

OBJECTIVES

This study investigated the effects of Cannabis sativa (CS) and melatonin on oestrus cycle, ovulation and reproductive hormones.

METHODS

Twenty female rats were assigned into four groups of five animals each, such that the rats received orally 1mL distilled water, 2mg/kg body weight (BW) of CS, 2mg/kg BW of CS plus 4mg/kg BW of melatonin and 4mg/kg BW of melatonin, respectively. Vaginal smears were taken daily to determine the stages of oestrus cycle. Ova counts were done according to the method described by Kim et al., 1994. Gonadotropin releasing hormone (GnRH), Luteinising hormone (LH), follicle stimulating hormone (FSH), oestradiol (E) and progesterone were determined using standard methods.

RESULTS

CS significantly (p<0.05) lengthened the metestrus and dioestrus phases of oestrus cycle. However, it significantly (p<0.05) shortened the proestrus and estrus phases respectively. There was significant (p<0.05) decrease in the ova count of the cannabis‐treated group when compared with the control and other treatment groups. In addition, animal treated with CS significantly (p<0.05) decreased the GnRH, FSH, LH, E and progesterone levels respectively. All these effects were ameliorated when combined with melatonin to the level comparable to the control.

CONCLUSION

This study showed some of the gonadotoxic effects of CS which could be mediated by endocrine disruption. However, these effects could be ameliorated by melatonin.
Role of Intracellular Toll Like Receptors (TLRs) in the Secondary Events of Traumatic Brain Injury
Authors: Paterniti Irene , Campolo Michela , Lanza Marika , Filippone Alessia , Scuderi Sarah , Casili Giovanna , Cuzzocrea Salvatore , Esposito Emanuela
Published: April 2020

The mechanisms underlying secondary brain damage following traumatic brain injury (TBI) is still unclear. Many studies demonstrated that inflammatory cascades contribute to brain damage through the activation of immune/inflammatory responses, including the increased release of cytokines and chemokines as well as the recruitment of leukocytes. The cells and tissues damaged by primary mechanical injury released a number of endogenous factors acting as damage‐associated molecular patterns (DAMPs), which initiate and perpetuate noninfectious inflammatory responses through transduction signaling pathways. Toll‐like receptors (TLRs) are a transmembrane receptor family that can recognize the specific DAMPs released from damaged cells and recruit a set of adaptors leading to the activation of downstream kinases and nuclear factors which regulate the expression of inflammatory genes. The activation of inflammatory responses mediated by TLR signaling is closely associated with brain tissue damage and neurological dysfunction following TBI. Since the role of intracellular TLRs such as 7, 8 and 9 after TBI is still unclear, we decided to evaluate the outcome and the secondary brain damage after TBI in TLR 7/8−/−and TLR 7/9−/−double KO mice. We performed a TBI, using a validate experimental model of controlled cortical impact injury (CCI), both TLR 7/8−/−and TLR 7/9−/−and in wild type (WT) mice. 24h thereafter we evaluated the contusion volume, the brain edema formation, the expression of pro‐inflammatory cytokines as well as the activation of immune response.Thus the obtained results demonstrated that modulation of intracellular TLR‐mediated signaling may attenuate brain damage and improve TBI outcome. Therefore, the intracellular TLRs and their downstream protein kinases may be potential targets for the treatment of TBI.
Crystal structure of the human phospholipase D1 catalytic domain provides insight into activation by PI(4,5)P2 and RhoA
Authors: Airola Michael V. , Bowling Forrest , Salazar Christian , Frohman Mike
Published: April 2020

The signal transduction enzyme phospholipase D1 (PLD1) hydrolyzes phosphatidylcholine to generate the lipid second‐messenger phosphatidic acid, which plays roles in disease processes such as thrombosis and cancer. PLD1 is directly and synergistically regulated by Protein Kinase C, ARF and Rho GTPases, and the membrane lipid phosphatidylinositol‐4,5‐bisphosphate (PIP2). Here, we present a 1.8Å‐resolution crystal structure of the human PLD1 catalytic domain that is characterized by a globular fold with a funnel‐shaped hydrophobic cavity leading to the active site. Adjacent is a PIP2‐binding polybasic pocket at the membrane interface that is essential for activity. The C‐terminus folds into and contributes part of the catalytic pocket, which harbors a phosphohistidine that mimics an intermediate stage of the catalytic cycle. Mapping of PLD1 mutations that disrupt RhoA activation identifies the RhoA‐PLD1 binding interface. This structure sheds light on PLD1 regulation by lipid and protein effectors, enabling rationale inhibitor design for this well‐studied therapeutic target.

Support or Funding Information

This work was supported by the NIH awards: R35GM128666 (MVA), T32GM092714 (FZB), and R01GM084251 (MAF), and the NSF award: 1612689 (CMS).
Why Donate Your Body to Science?: Analysis of Mississippi’s Donor Rationale
Authors: Mueller Caroline Marie , Klender Sara Marie , Conway Marianne
Published: April 2020

Whole body donation is fundamental to medical education and research because human dissection provides an educational tool for the training of healthcare professionals. Current research is limited regarding the characteristics and the rationale of donors who bequeath their bodies to whole body donation programs. Most studies have been conducted outside of the United States and have focused on demographics. The few studies that have focused on donor rationale found that the majority of donors donate for altruistic reasons. In continuation with a previous study on retrospective donor pool demographics in Mississippi, this study looked to further investigate the reasons for body donation. Mississippi has a high number of preregistered donors and investigation as to why this population donates could aid in recruitment of donors in other states. This study aimed to investigate the demographics and motives of prospective donors who have completed whole body preregistration forms within the state of Mississippi from January 2017 to August 2019. A survey was sent to registered donors via email or was included in an updated preregistration form for perspective donors. Demographic information and responses to the rationale survey were analyzed using descriptive statistics. Further analysis will aim to compare these demographics with retrospective data on previous donor populations to determine potential changes. The analysis of the motives and demographics of the donors may contribute to improving the efficiency of donor recruitment in order to continue training healthcare practitioners.