bluuebunny/crossref_metadata_2025 huggingface dataset:
Insights into the mechanisms of inflammatory acidification within the mucosa
Authors: Cartwright Ian Michael , Lanis Jordi M. , Alexeev Erica E. , Schaefer Rachael E.M. , Welch Nichole , Kostelecky Rachael , Gao Rachel , Onyiah Joseph C. , Colgan Sean P.
Published: April 2020

Tissue acidification is commonly associated with a number of inflammatory states. The primary mechanism of extracellular acidification is thought to be increased accumulation of lactic acid resulting from enhanced glycolysis. Like other chronic inflammatory diseases, tissue acidification has been observed in inflammatory bowel disease patients, with reports of colonic pH as low as 4. We have recently demonstrated that neutrophil (PMN) transepithelial migration rapidly acidifies the microenvironment resulting in inflammatory acidification in the mucosa. Very little is known with regard to the mechanism(s) involved in this acidification or the impact of such acidification on the intestinal epithelial cell (IEC) function. Initial observations showed that physical interaction between IEC and PMN was required for inflammatory acidification; however, when transmigration was blocked using anti‐CD11b antibodies, we observed significant extracellular acidification in the absence of PMN transepithelial migration. This observation suggests that binding of the CD11b receptor plays a crucial role promoting extracellular acidification. Expanding upon these observations, we analyzed extracellular lactate secretion. We observed that lactic acid was released by IEC 4 to 5 hours after the addition of PMN and in quantities not high enough to account for the extracellular acidification observed. Additionally, the concentration of lactic acid released in the anti‐CD11b treated cells was similar to control IEC in the absence of PMN. When combined, these data indicate lactate is not a significant mediator of extracellular acidification following PMN transmigration. Given the large number of PMNs present and chronic tissue acidification observed during active inflammation, we investigated the impact of extracellular acidification on the regulation of epithelial derived pro‐inflammatory markers. When T84 IEC were cultured in pH 6.0 media for 3 or 6 hours we observed increases in pro‐inflammatory markers, including IL‐8. To better understand how extracellular acidification alters IEC gene regulation, we utilized a transcription factor array to examine changes in transcription factor expression under acidic conditions. This screen identified CREB as one of the major transcription factors controlling responses to acidification. Further examination revealed that CREB phosphorylation occurs rapidly, is cAMP independent, and requires MSK1. Inhibition of MSK1 prevents the induction of IL‐8 and other acidification associated gene transcription. Theses result identified extracellular acidification as a significant signaling mechanism during tissue inflammation. Targeted regulation of MSK1 may serve as a new therapeutic approach to limit pro‐inflammatory signaling during mucosal inflammation.

Support or Funding Information

R01 DK095491, NIH
The Bacterial Serine Dipeptide Lipid, Lipid 654, Attenuates Atherosclerosis Development in LDL‐Receptor Knockout Mice Fed a Western‐Type Diet
Authors: Garcia Chelsea , Millar Courtney L. , Anto Liya , Nichols Frank C. , Blesso Christopher N.
Published: April 2020

Bacteroidetes of the oral and gut microbiome produce serine‐glycine dipeptide lipids that activate Toll‐like receptor 2. Lipid 654 (L654), a major serine dipeptide lipid class, has been detected in serum, brain, and carotid arteries of humans. We investigated the effects of L654 on atherosclerosis development in male low‐density lipoprotein receptor knockout (LDLr−/−) mice fed a high‐sucrose, Western‐type diet (HFD; 21% milk fat, 0.2% cholesterol, 34% sucrose by weight). Mice were fed either a standard chow diet (n = 9) or HFD (n = 30) for 14 weeks. During the last 7 weeks of the HFD, mice were intraperitoneal‐injected 3 times per week with either 1 μg of L654 (HFD‐L654, n = 15) or vehicle (HFD‐Veh, n = 15). L654 was detected in mouse feces and liver by UPLC‐MS/MS. Compared to chow‐fed mice, mice fed HFD had lower fecal Bacteroidetes relative abundance (−28%) and fecal L654 concentrations (−82%). In the context of HFD, L654 had a hypocholesterolemic effect with HFD‐L654 having significantly lower cholesterol concentrations in both serum (−24%) and liver (−35%) compared to HFD‐Veh. L654 also reduced hepatic inflammation, as HFD‐L654 had lower serum ALT (−43%) and hepatic pro‐inflammatory gene expression (~30–45% lower) compared to HFD‐Veh. Finally, L654 attenuated atherosclerosis, as HFD‐L654 had significantly lower aortic root lesion size (−39%) compared to HFD‐Veh. In summary, a Western‐type diet markedly lowered fecal L654 concentrations in LDLr−/− mice. Chronic L654 administration protected against several metabolic defects induced by Western‐type diet, including hyperlipidemia, liver inflammation, and atherosclerosis development. Further studies are warranted to assess the underlying metabolic effects of these unique class of bacterial lipids.
The Roles of Essential Proteins Prp6 and Dib1 During Pre‐mRNA Splicing in Saccharomyces cerevisiae
Authors: Embry Addie , Jameson Danielle , Turner Caitlyn , Maeder Corina
Published: April 2020

Pre‐mRNA splicing is a conserved biological process essential to all eukaryotes. Splicing defects lead to a variety of disorders in humans including Retinitis Pigmentosa and Burn‐McKeown Syndrome, defining the importance of splicing in health science fields. Pre‐mRNA splicing requires complex machinery composed of five small nuclear RNAs (snRNAs) complexed with numerous proteins that form five small nuclear ribonucleoproteins (snRNPs). Spliceosome assembly occurs over several dynamic steps to form a pre‐catalytic B complex before splicing reactions can occur (Will, et al. 2011; Plaschka, et al. 2017).

Splicing cannot occur until the pre‐mRNA can interact with the Prp8 protein and the U5 snRNA in the catalytic center of the spliceosome. Analysis of cryo‐EM structures reveal that the essential proteins Dib1 and Prp6 in the B complex block pre‐mRNA from interaction with the catalytic site. Dib1, a 17‐kDa protein with a thioredoxin‐like (TRXL) domain, sits at the center of the catalytic site (Plaschka, et al. 2017). Although small, Dib1 contains distinct features that includes a solvent‐exposed hydrophobic groove which appears to interact with the N‐terminus of Prp6, a large, 102‐kDa U4/U6.U5 triple‐snRNP protein (Reuter, et al. 1999; Plaschka et al. 2017). Studies of S. pombe and human splicing proteins demonstrated interactions between Prp6 and Dib1 orthologs, and deletion of at least the first 50 amino acids of the Prp6 N‐terminal region halted pre‐mRNA splicing in S. pombe (Liu, et al. 2006; Lutzelberger, et al. 2010).

Prp6 and Dib1 must depart the spliceosome before splicing can occur. The interactions between these proteins and the catalytic site of the B complex may serve to stabilize the spliceosome and prevent premature pre‐mRNA splicing. Interactions between Prp6 and Dib1 may also mediate assembly of the spliceosomal B complex. We previously reported that a temperature‐sensitive (ts) mutation in the Dib1 hydrophobic pocket impaired pre‐mRNA splicing, and preliminary assembly assays run on native polyacrylamide gels suggest the Dib1 mutation affects spliceosome assembly. Additionally, we reported that a N‐terminal deletion of Prp6 also halted splicing. Here, we will report new (ts) growth mutants in the N‐terminus of Prp6 that may interact with the Dib1 hydrophobic groove and determine if they inhibit splicing. We will also report continued studies of the effects of existing Prp6 and Dib1 mutants and how they affect splicing and spliceosome B complex assembly.

Support or Funding Information

NIH‐NIGMS R15GM120720 and The Welch Foundation
Determining the Role MK‐STYX plays in Autophagy in Regard to LC3B Expression
Authors: Leibow Spencer Robert , Christian Patrick , Hinton Shanta
Published: April 2020

Cellular processes are maintained at maximum efficiency by ridding cells of redundant and extraneous organelles, proteins, and other cellular compounds. Components of these cellular processes are not completely lost. Rather, they can be recycled into new materials, a cellular recycling system driven by autophagy (specifically macroautophagy). Autophagy has been reported to clear stress granules, aggregations of stalled mRNA, which are toxic to the cell at high concentrations. MK‐STYX [mitogen‐activated protein kinase (MAPK) phosphoserine/threonine/tyrosine‐binding protein] has also been reported to clear stress granules. MK‐STYX is an atypical member of the protein tyrosine phosphatase (PTP) superfamily, because its catalytic signature motif does not contain the essential nucleophilic cysteine required for catalytic activity. The correlation that stress granules decrease through MK‐STYX and/or autophagy provides a foundation for this research. We are investigating the role of pseudophosphatase MK‐STYX in autophagic pathways via its effects on the expression of the autophagosome‐promoting protein, LC3B (microtubule‐associated protein 1A/1B‐light chain 3). Western blots show that LC3B expression increased in HEK/293 cells overexpressing MK‐STYX. This correlation elaborates upon previous research, having potential for developing a deeper understanding of the mechanisms with which MK‐STYX affects the decrease of stress granules in the cell. Our future studies will characterize MK‐STYX’ relationship to other autophagic proteins. Further elucidating the interactions and mechanisms of and between MK‐STYX and autophagic proteins may aid in unfolding the ways in which MK‐STYX halts the assembly of stress granules.
Identification of Patent Foramen Ovale Channel Related Morphometric Features Increasing the Risk of Cerebrovascular Accidents: a Systematic Review and Meta‐analysis
Authors: Holda Jakub Piotr
Published: April 2020

Introduction

It is still disputable whether specific morphometric features of the patent foramen ovale (PFO) channel may stratify patients by the related probability that a discovered PFO is incidental or stroke related. Thus, we aimed to determine this using a meta‐analytical approach.

Materials and Methods

We performed a systematic review of electronic databases for studies that compared morphometric parameters of PFO channel assessed by transesophageal echocardiography in subjects with cryptogenic cerebrovascular accidents (Group 1) and control (Group 2). Data were extracted and pooled into a meta‐analysis.

Results

A total of 895 patients with PFO channel were reported (Group 1: 493, Group 2: 402). No difference was found in the PFO channel length (Group 1: 10.8 [8.6–12.9] mm vs. Group 2: 10.4 [9.1–11.7] mm), as well as in PFO height measured at rest (Group 1: 2.4 [1.5–3.3] mm vs. Group 2: 1.8 [1.4–2.2] mm). The PFO height measured during Valsalva was larger in Group 1 (3.5 [2.8–4.1] mm) than in Group 2 (1.7 [1.2–2.2] mm). Also, the septal excursion distance was larger in Group 1 (6.4 [5.1–7.8] mm) than in Group 2 (3.1 [1.8–4.4] mm). The risk of cerebrovascular accident was higher in patients with PFO and concomitant septal aneurysm (OR=4.00; 95%CI: 2.63–6.09; p<0.001) and large right‐to‐left shunt PFO (more than 20 microbubbles) (OR=3.81; 95%CI: 2.21–6.55; p<0.001).

Conclusions

Larger PFO height during Valsalva, larger septal excursion distance, concomitant atrial septal aneurysm and large right‐to‐left shunt are stroke high‐risk echocardiographic features of the PFO channel.
Ecm2 Functions to Support U6 snRNA Structure and Dynamics during Spliceosome Catalysis
Authors: Schneider Charles W. , van der Feltz Clarisse , Hoskins Aaron A.
Published: April 2020

Spliceosomes catalyze the removal of non‐coding regions, or introns, from pre‐mRNA. Assembly of the small nuclear RNA (snRNA) core of spliceosomes occurs anew on each intron via a series of carefully coordinated conformational rearrangements. However, the functional importance of many of the snRNA‐protein interactions guiding these rearrangements remain unknown. The splicing factor Ecm2 integrates into the spliceosome adjacent to the active site, where it interacts near a region of the U6 snRNA forming the catalytic RNA core of the spliceosome. By combining mutations in the U6 snRNA that perturb splicing catalysis with Ecm2 deletion in yeast, we have determined that Ecm2 functions during the chemical steps of splicing. While Ecm2 deletion or U6 mutations can be tolerated by yeast individually, we demonstrate strong synthetic interactions between these factors. We have further characterized the impact of Ecm2 deletion on splicing in vivo using a reporter pre‐mRNA. Neither Ecm2 deletion nor the U6 mutations impact splicing of pre‐mRNAs containing strong splice sites. However, both Ecm2 deletion and U6 mutation change splicing when the pre‐mRNAs contain weak, non‐consensus splice sites. Moreover, many changes observed with U6 and Ecm2 are dependent on both factors. For example, Ecm2 deletion promotes splicing of pre‐mRNAs containing a substitution at the +5 position of the 5'SS but mutation of U6 eliminates this effect. We propose that Ecm2 stabilizes U6 conformation so that it may re‐arrange to support the catalytic steps of splicing.
Neuroprotective Effects of N,N′bis‐(2‐mercaptoethyl) Isophthalamide (NBMI) Against Lead Induced Toxicity in U‐87 MG Cells
Authors: Gadde Rajitha , Betharia Swati
Published: April 2020

Background and Objective

Lead is one of the most dangerous and ubiquitous environmental toxins with no levels safe for human exposure. Lead causes neurotoxicity primarily by inducing oxidative stress. After crossing the blood brain barrier, lead is taken up by glial cells which serve as protective lead‐binding proteins. While chelation is the mainstay of therapy for lead poisoning, currently FDA approved chelators such as dimercaptosuccinic acid (DMSA) are associated with many adverse effects and safety concerns. N,N′bis‐(2‐mercaptoethyl) isophthalamide (NBMI) is a newer lipophilic water insoluble compound with potential metal chelating and antioxidant properties. The purpose of this study was to determine whether NBMI displayed neuroprotective effects in U‐87 malignant glioblastoma (U‐87 MG) cells exposed to lead acetate (PbAc).

Materials and Methods

U‐87 MG cells were treated with either vehicle, NBMI (0–100 μM), or DMSA (0–100 μM) for 24 hours followed by PbAc (0–300 μM) for 48 hours. Cell viability (CellTiter‐Glo® Assay), cell morphology (trypan blue staining), degree of oxidative stress (GSH‐GloTM Glutathione Assay), and impact on apoptosis (Bax and Bcl‐2 protein levels using Western blotting) were determined. Comparisons between multiple groups were performed using one‐way or two‐way analysis of variance (ANOVA) followed by a post‐hoc Tukey’s test. Results with a p value <0.05 were considered statistically significant.

Results

Exposure of U‐87 MG cells to PbAc decreased cell viability in both a concentration and time‐dependent manner. Trypan blue staining revealed that PbAc negatively altered the cell morphology. In addition, PbAc exposure led to an increase in total glutathione levels, as well as the Bax/Bcl‐2 ratio, indicating increased oxidative stress and initiation of the cell apoptotic pathway. Pretreatment with NBMI diminished PbAc‐induced cell death, morphology changes, increase in total GSH, and increase in the Bax/Bcl‐2 ratio. Interestingly, the effects of NBMI were more prominent compared to DMSA in attenuating PbAc‐induced cell death.

Conclusion

Lead exposure induces cell death and oxidative stress which are reversed by pretreatment with NBMI implying that NBMI is a new and promising chelator for treating PbAc‐induced neurotoxicity.
Predator scent stress induces anxiety and sensitizes the angiotensin II‐elicited hypertensive response
Authors: Xue Jiarui , Beltz Terry G. , Xue Baojian , Johnson Alan Kim
Published: April 2020

Post‐traumatic stress disorder (PTSD) is associated with increased risk of cardiovascular diseases. In the present study, we examined the cardiovascular, biochemical and behavioral consequences of exposing animals to a predatory scent paradigm. After exposures, we measured factors associated with stress responses in a standardized behavioral test. We also determined the hypertensive response to angiotensin (ANG) II and expression levels of the renin‐angiotensin system (RAS) and proinflammatory cytokines (PICs) in the lamina terminalis (LT), paraventricular nucleus (PVN) and amygdala (Amy). Rats (male Sprague‐Dawley) were placed in a plastic‐shoebox cage and exposed to coyote urine in three 20‐minute sessions on alternating days (stressed). A second group served as home‐cage controls. Three days after the last exposure, three separate cohorts of animals following an identical experimental protocol were studied for 1) sensitization of the hypertensive response, 2) performance in the elevated “plus” maze in order to assess anxiety and 3) changes in expression of mRNA for components of the RAS and markers of inflammation in the LT, PVN and Amy. Stressed rats, compared to the controls, had a significantly greater hypertensive response when challenged with a slow‐pressor dose of ANG II (sensitization), exhibited a significant preference to the closed arms as well as general immobility (i.e. enhanced anxiety) and an upregulated expression of several components of the RAS and PICs in the LT, PVN and amygdala. The results suggest that the predatory scent paradigm, a model for PTSD, sensitizes ANG II‐induced hypertension and induces behavioral signs of anxiety in rats, probably through upregulation of RAS and PICs components in key brain areas associated with fear and the central sympathetic control of blood pressure.

Support or Funding Information

NIH HL139575
Enteric Glia Contribute to Visceral Hypersensitivity Through Interactions with Nociceptors
Authors: Morales-Soto Wilmarie , Gulbransen Brian D.
Published: April 2020

Enteric glia regulate gut motility, secretions, and neuroinflammation through intercellular signaling mechanisms that involve connexin‐43 (Cx43) hemichannels. Glial Cx43 signaling is active during the acute phase of colitis when the sensitization of nociceptors occurs, but how glia contribute to nociceptor sensitization is not known. Here, we tested the hypothesis that alterations to intercellular signaling between glia and nociceptors mediated by Cx43 contribute to the sensitization of nociceptors during gut inflammation. We used the dinitrobenzene sulfonic acid (DNBS) model of acute colitis and tested the effects on enteric glia using immunohistochemistry, multiplex immunoassays, and ethidium bromide dye uptake to measure glial Cx43 channel activity. Specific interactions between glia and nociceptors were assessed using the glial specific GFAP::hM3Dq DREADD mouse model in combination with visceromotor reflex recordings and pERK expression, and by directly recording nociceptor nerve fiber activity in TRPV1‐GCaMP5g‐tdT mice. DNBS colitis drove an increase in proinflammatory cytokines including IL6, TNFα, and IL17, and IL1β showed a 5‐fold increase (p<0.05) at peak inflammation. Enteric glia contribute to IL1β production and immunolabeling data showed a 40% increase in glial IL1β (p<0.05) that was confirmed by RNAseq data (2‐fold, p<0.05). The pro‐inflammatory mediators IL1β, IL6, INFy, and TNFα increased glial dye uptake under basal conditions and IL1β and IL6 potentiated ADP‐stimulated dye uptake by 24% and 53%, respectively (p<0.0001), in a Cx43‐dependent manner. The selective activation of glial cells with clozapine‐N‐oxide in GFAP::hM3Dq mice increased visceromotor responses to colorectal distensions (p<0.05) and drove pERK expression in TRPV1+ sensory nerve fibers in the myenteric plexus. Neither IL1β nor glial activation alone significantly affected Ca2+ responses to capsaicin in TRPV1+ nerve fibers in the colon. However, glial activation in the presence of IL1β significantly potentiated nociceptor Ca2+ responses to capsaicin and this effect required signaling through Cx43 hemichannels. Our data show that enteric glia can affect the sensitivity visceral nociceptors in the context of inflammation through mechanisms that include the potentiation of glial Cx43 hemichannel function by IL1β and the subsequent sensitization of TRPV1 channels expressed by sensory neurons.

Support or Funding Information

National Institute of Health through NIDDK: R01DK103723, R01DK120862
Comparison of Student Perceptions of Flipped Teaching in Undergraduate STEM Courses Across Two Institutions
Authors: Dickey Paige E , Fickas Julie , Bartels Lynn , Bracey Georgia , Locke Sharon , Gopalan Chaya
Published: April 2020

Flipped teaching (FT) creates an environment to actively engage the learner as opposed to the often passive learning experience of traditional lecture‐based teaching (TT). Evidence has shown that FT can increase student engagement when lecture is shifted outside of the classroom through pre‐class activities while spending in‐class time working on activities at higher Bloom’s taxonomy levels. Research is lacking on which student population would benefit most from the FT. Six faculty from a four‐year institution and six faculty from a two‐year community college from STEM disciplines were selected to complete faculty development training on FT techniques. Upon completion of their training, faculty implemented FT in their classrooms the following semester. Student surveys were administered in each of these classes at the end of the semester. Students’ perception of engagement in the university STEM classes was significantly higher (p<0.0001) compared to community college STEM classes. Similarly, the university students’ level of confidence with the course material was significantly higher (p=0.0002) compared to the community college students. When overall attitude toward FT was assessed, the university students had a significantly more favorable attitude (p<0.0001) than the community college students. University students were significantly more likely to take another flipped course (p=0.0001) as well as recommend another student to take a flipped course (p<0.0001) than the community college students. Based on these results we conclude that students in the university setting have a more positive and receptive attitude toward FT compared to community college students.

Support or Funding Information

National Science Foundation
Musculature of the head and neck in naked mole‐rats (Heterocephalus glaber)
Authors: Thurber Mikaela , Diogo Rui , Sarko Diana
Published: April 2020

Naked mole‐rats (Heterocephalus glaber) are eusocial, subterranean rodents from the family Bathyergidae. Their unusual anatomical and physiological traits, including a number of adaptations to their fossorial and eusocial niche, have been relatively under‐studied compared to other rodent species. They have large incisors that are used for social interactions (as well as defense); for navigation and object manipulation; for feeding; and for digging complex tunnel systems. In addition, naked mole‐rats have unusual oral folds that close caudal to their incisors, preventing dirt from entering their oral cavity while digging. They are functionally blind and have reduced pinnae. However, their well‐developed tactile system ‐ relying on their incisors as well as tactile hairs covering the entire body ‐ compensates for their reduced visual and auditory systems.

Naked mole‐rat head and neck musculature might also be expected to have adapted to a subterranean niche and present with neotenic features. However, few studies to date have characterized naked mole‐rat musculature. To address this, we performed detailed anatomical dissections on adult naked mole‐rats in order to investigate the presence and attachment sites of the head and neck musculature. We found adaptations to a subterranean niche. For example, musculature associated with ear and eye movements was reduced. Overall, our findings provide insight into head and neck musculature as they relate to ecological and evolutionary adaptations, which can be placed within a comparative anatomical context based on what is present in other species.
Characterizing the coexistence of two stable sub‐populations in an experimentally evolved ionizing radiation resistant Escherichia coli lineage
Authors: Steigerwald Emma , Lancaster Illissa J. , Liu Jessica , Wood Elizabeth , Bruckbauer Steven , Cox Michael M.
Published: April 2020

After nearly 130 rounds of selection, experimental evolution of four replicate Escherichia coli populations has generated extreme ionizing radiation (IR) resistance. After approximately 80 rounds of selection, IR9—one of the evolved lineages—developed two distinct sub‐populations that are readily distinguishable by white and yellow colony phenotypes. Isolates that represent the two sub‐populations at round 100 of selection (IR9‐100‐1, a white isolate; IR9‐100‐2, a yellow isolate) share 367 point mutations; however, they have 401 (IR9‐100‐1) and 430 (IR9‐100‐2) mutations differentiating the two isolates. In addition, these isolates display differential IR‐resistance (with IR9‐100‐2 being more IR‐resistant than IR9‐100‐1) and growth phenotypes (IR9‐100‐1 exhibiting less of a growth defect). Furthermore, in the absence of IR‐selection, neither isolate out‐competes the other in growth competition assays. The yellow phenotype is founded in an accumulation of porphyrin (a precursor to heme) as cell lysates of IR9‐100‐2 produce an absorbance peak at approximately 400 nm, which is absent in IR9‐100‐1 and Founder strain; this absorption spectrum is suggestive of porphyrin accumulation in IR9‐100‐2. To further characterize this phenotype and understand the relationship between these two sub‐populations, the promoter of sodA (encoding super oxide dismutase A) and a synthetic promoter (PfepBS, controlled by the Fur iron sensing transcription factor) were utilized in β‐galactosidase assays. Preliminary results show that both subpopulations have elevated sodA expression compared to the Founder strain, indicating excess ROS stress. Additionally, the PfepBS activity assays reveal that both subpopulations, especially 9‐100‐1, are iron‐starved. Both the iron starvation and the elevated ROS levels could be contributing factors which drive the overproduction of porphyrin in IR9‐100‐2 and may explain the coexistence between each subpopulation.
Characterization of Viral Communities Carried by Male and Female Aedes Mosquitos Collected in Houston
Authors: Brittain David D.
Published: April 2020

Mosquitos are known vectors of many serious viral diseases, but little is known about the complete collection of viral strains that they might carry. This is because we have historically relied on culturing techniques to study microbial diversity, but the genomic era has shown us that there is much more out there than we initially suspected. In this work, we present a genomic approach to characterizing the viral populations carried by different species of mosquitos found in Houston. Specifically, we are using metagenomics – that is, sequencing the entire genetic material in a sample, followed by analyses by computational tools to identify each sequence obtained from the sample. We collected mosquitos from various locations in Houston and separated them by species and sex using morphological and genetic markers. Total DNA and RNA were purified from pooled samples in order to characterize both DNA and RNA viruses. RNA samples were converted to cDNA to facilitate sequencing and the combined DNA/cDNA libraries were sequenced using 454 technology. We used a modified BLAST workflow developed in‐house to analyze the sequences. Our first analysis shows viral sequences obtained for samples of male and female Aedes aegypti. While thousands of unknown sequences were obtained, our results show that we are also able to detect both DNA and RNA viral sequences in our samples. A total of 51 different species of viruses were identified in the female sample, and 40 different species were found in the male sample. Those of interest include West Nile and Dengue. Interestingly, the female sample carried more RNA viruses than the male sample, although further work will reveal if this finding is significant or an experimental artifact. We plan on further analyzing the sequence libraries obtained, with particular focus on the unknown sequences, many of which may be viral. We are also working on building new libraries from new samples of mosquitos, including other genera typically found in Houston, such as Culex. These analyses will help us better understand the viral collections carried by different mosquitos in our city.

Support or Funding Information

U.S. DOE Hispanic‐Serving Institutions STEM Articulation Grant P031C110128, the University of St. Thomas Cullen‐Smith Endowed Chair in Biology, and the University of St. Thomas Committee for Student Research.
Absolute Modification of Highly Reactive Cysteines via N‐ethylmaleimide Evokes Full, Prolonged TRPA1 Activation
Authors: Parks Thomas , Taylor-Clark Thomas
Published: April 2020

A subgroup of sensory nerve fibers called nociceptors is stimulated by noxious stimuli and evokes defensive responses in organ systems. Transient Receptor Potential Ankyrin 1 (TRPA1) is a tetrameric, non‐selective, cationic channel that is expressed in sensory neurons that initiate afferent signaling in nociceptive fibers when activated. Activation of TRPA1 initiates nociceptive signaling to the central nervous system and elicits defensive behaviors and reflexes in organ systems and throughout the body. TRPA1 is activated by environmental pollutants, exogenous food chemicals and endogenous irritants that are created during inflammation and oxidative stress. TRPA1 agonists are electrophilic compounds that covalently modify highly reactive cysteines on the intracellular side of the channel. Our lab has identified four highly reactive cysteines (C273, C621, C665, C1085) that rapidly bind to electrophiles, with C621 having a greater reactivity than the other three cysteines. It is known that electrophilic binding of cysteines contributes to TRPA1 activation; however, the underlying mechanism of activation is poorly understood. In this study, we utilize cell‐attached single channel patch‐clamp to observe stochastic gating events of human TRPA1 (hTRPA1) channels that is transiently expressed in HEK293 cells to better understand the mechanism that leads to TRPA1 activation. Recordings of stochastic TRPA1 gating events during N‐ethylmaleimide (NEM) treatment reveal two different activation profiles: (1) a weak activation (low open probability [Po]) that persists over time; (2) a weak activation followed by a rapid, spontaneous increase to full activation (near 100% Po). Mean open time histogram analysis shows that the full TRPA1 activation profile has longer event open time compared to weak TRPA1 activation, which has mean open times that are comparable to open times of random events during baseline conditions. Also, the mean maximum open times during full TRPA1 activation is 75 times longer than weak TRPA1 activation mean maximum open times. Our results suggest that differences in the full or weak TRPA1 activation profiles are due to a difference in how the cysteines are modified via NEM. We hypothesize that full activation is the result of absolute C621 modification (each C621 residue on the four TRPA1 subunits) that fully opens the channel, whereas weak activation is the result of individual C621 modification events (not all four C621 residues) that do not have an additive effect on TRPA1 channel activation.
Effects of combined exercise training and pharmacological treatment on blood pressure and renal parameters in an experimental model of hypertension and menopause.
Authors: dos Santos Ferreira Silva Michel Pablo , Shecaira Thânia Plens , Ferreira Maycon junior , de Araujo Amanda Aparecida , Bernardes Nathalia , da Silva Dias Danielle , De Angelis Kátia
Published: April 2020

In postmenopausal women, increased blood pressure (BP) has been well documented. Moreover, autonomic dysfunction, inflammation, and oxidative stress have important roles in the pathophysiology of hypertension, which was associated with end organ damage, such as the kidneys. On the other hand, pharmacological therapy and combined physical training have been clinically recommended for BP control. However, the impact of these therapies has not yet been fully understood, especially regarding to the impact on renal tissue. Thus, the aim of present study was to investigate the effects of combined physical training and antihypertensive pharmacological treatment on BP and renal parameters in an experimental model of hypertension and menopause. Spontaneously hypertensive 3‐month‐old rats (SHR) were divided into 5 groups: sedentary (S; n = 4), sedentary ovariectomized (SO; n = 4), hydrochlorothiazide‐treated sedentary ovariectomized (HSO; n = 4), trained ovariectomized (TO; n = 3) and trained hydrochlorothiazide‐treated ovariectomized (THO; n = 4). Ovariectomy was performed by bilateral removal of the ovaries. After 5 days of treatment (placebo or pharmacological) and adaptation to the treadmill and training ladder, groups S and OS continued with placebo treatment for 8 weeks, while the other groups continued treatment with antihypertensive drug (30mg / kg Hydrochlorothiazide diluted in drinking water) and / or CPT (3 days / week, 40–60% of maximum capacity). Tail plethysmography BP measurements were performed at one pre‐intervention week and at the 1st, 4th and 8th intervention weeks. At week 7, the rats were kept in metabolic cages for 24 hours to collect urine. There was no difference between the groups for pre‐intervention BP. The THO, TO and HSO groups had reduced BP levels compared to the SO group at the end of the protocol (p <0.01). There was a correlation between physical capacity on stairs (PCS) and BP levels at week 1 (r = −0.49) and week 4 (r = −0.48). There is no difference in urinary output between groups; However, metabolic cage urine output correlated with treadmill physical capacity (PCT) (r = −0.47). Right kidney weight was significantly lower (p <0,01) in TO and THO groups compared to SO group (0.63±0.01; 0.63±0.01 vs. 0.79±0.08 g). Kidney weight was correlated with PCT (r = −0.59), urinary output (r = 0.73) and water consumption (r = 0.53). In conclusion, despite the results suggest similar benefits of pharmacological and non‐pharmacological treatment in the management of BP in the presence of ovarian hormone deprivation, attenuation of hypertension and menopause induced‐renal alterations was associated with improvement in physical capacity.
Selective androgen receptor modulation with MK‐2866 favorably alters muscle mitochondrial bioenergetics
Authors: Walton Chase M. , Saito Erin , Jacobsen Samuel , Thomson David M. , Bikman Benjamin T.
Published: April 2020

Musculoskeletal pathologies such as sarcopenia and cachexia are increasingly prevalent within an aging global society. Musculoskeletal wasting is not limited to age and is increasingly recognized in the pathogenesis of multiple chronic diseases, including cardiometabolic disorders, such as insulin resistance and type 2 diabetes. Naturally, efforts to promote the maintenance of, if not increase in, lean mass could yield protective, disease‐delaying benefits. Selective androgen receptor modulators (SARMs) have been available for several years and have recently been studied as a treatment for muscle wasting. Considering how little is known regarding the effects of SARMS on muscle mitochondrial function, and in light of the relevance of mitochondria on muscle cell dynamics, we sought to determine the specific effects of MK‐2866 on muscle cell mitochondrial function. Following incubation of murine muscle cells with MK‐2866, we found that mitochondrial ATP production was significantly increased, while mitochondrial respiration significantly decreased. Moreover, this same treatment regimen yielded a significant increase in muscle cell proliferation and protein synthesis. Future work will reveal the degree to which the mitochondrial changes from MK‐2866 are necessary for muscle cell proliferation and protein anabolism.
Characterizing 17‐β Estradiol as a Precipitating Factor in Heightened Stress Susceptibility in Female Rats
Authors: Calatayud Brittney M , Harrington Evelynn N , Pope Brittany S , Wilson Marlene A , Wood Susan K
Published: April 2020

Social stress is a common risk factor for anxiety and women are twice as likely as men to develop stress‐related disorders. Mechanisms behind this increased risk remains unclear, thereby limiting targeted therapeutic options. Because females are only at increased risk following puberty until the end of menopause, this suggests that estrogen, the predominant female hormone, might be responsible for sensitizing neural targets involved in stress‐related psychopathology. The current study aimed to characterize the role that estrogen may play in sensitizing behavioral dysfunction produced by social stress exposure in females. First, timecourse studies were conducted to determine the appropriate dose and estradiol formulation to accurately mimic the estrous cycle. These findings led to the following study design: Female rats were either intact or ovariectomized (OVX) and treatment consisted of an injection of 17‐β Estradiol (17βE, 10ug/rat, subcutaneous) or vehicle (sesame oil) administered every 4 days to mimic the rat estrus cycle. Female rats (Intact + vehicle, OVX+vehicle, and OVX+17βE were then subjected to witnessing an aggressive social defeat encounter between a male intruder and a novel male resident for 15 min on 5 consecutive days, or a non‐stress control environment. Stress and anxiety‐like behaviors were quantified on days 1 and 5 including stress‐evoked burying, rearing and freezing. Despite witnessing a comparable number of attacks, intact females were highly sensitive to witness stress as demonstrated by increased anxiety‐like burying compared with OVX rats treated with vehicle. Importantly, cyclic administration of 17βE reinstated burying behavior in OVX females. Rearing and freezing behavior analysis is ongoing. These studies provide evidence of estrogen’s primary role in enhancing stress susceptibility, evidenced by increased anxiety‐like responses to social stress. Moreover, this study lays the foundation for future work to identify the specific neural systems that are sensitized by estradiol to identify neurotherapeutic targets to treat the increased stress susceptibility in females.

Support or Funding Information

Support provided by MH113892‐01A1 (SKW), NARSAD Young Investigator Award 26809 (SKW), South Carolina Honors College Exploration Scholars Research Program (BMC)
Diethyl pyrocarbonate modification of the ligating histidines in the CuA protein from Thermus thermophilus
Authors: Hunsicker-Wang Laura
Published: April 2020

The CuA protein is subunit II of cytochrome oxidase, the terminal enzyme in the electron transport chain. The binuclear metal center of the CuA protein is ligated by two bridging cysteines, two histidines and two weakly interacting ligands. Diethyl pyrocarbonate (DEPC) is a common chemical modifier that reacts with histidines, lysines, and the N‐terminus of proteins. DEPC was used to probe the reactivity of the ligating histidines of the CuA protein to identify if one or both of them would be susceptible to modification. Visible circular dichroism and UV‐Visible spectroscopies were utilized to show the changes in the spectra upon modification and the data suggest that at least one of the ligating histidines becomes modified. Using fewer equivalents showed that as few as 5 equivalents results in modification of the ligating histidine. Electron paramagnetic resonance indicated that the cluster remains oxidized after modification. These results point to the role of the ligating histidines in modulating the redox properties of this cluster. Mononuclear proteins, including azurin and Sco, were also tested and these proteins do not display ligating histidines reactive toward DEPC. Thus, DEPC reactivity is not a property of all ligating histidines.

Support or Funding Information

Arnold and Mabel Beckman Foundation Beckman Scholars Program
Lutibacter citreus sp. nov., isolated from Arctic surface sediment
Authors: Du Zhao-Zhong , Zhou Liu-Yan , Wang Tao-Jie , Li Hui-Rong , Du Zong-Jun
Published: April 2020

A Gram-stain-negative, aerobic, non-motile, non-gliding, yellow-pigmented and rod-shaped bacterial strain, designated 1KV19T, was isolated from a surface sediment sample collected near a bay in the Arctic. Growth of strain 1KV19T occurred in 1–4 % (w/v) NaCl (optimum, 2 %), at 4–35 °C (optimum, 25–30 °C) and at pH 6.5–8.0 (optimum, pH 7.0–7.5). The phylogenetic trees based on the 16S rRNA gene sequences showed that strain 1KV19T was associated with the genus

Lutibacter

and had the highest 16S rRNA gene sequence similarity to

Lutibacter oceani

325-5T with 98.1 % similarity. Similarity values between strain 1KV19T and the type strains of other

Lutibacter

species were in the range 95.9–97.6 %. The average nucleotide identity and digital DNA–DNA hybridization values between strain 1KV19T and related species of the genus

Lutibacter

were 76.4–79.1 and 19.9–22.3 %, respectively. The major cellular fatty acids of strain 1KV19T were iso-C15 : 0 3-OH, iso-C15 : 0 and iso-C16 : 1 H. The respiratory quinone was MK-6. The major polar lipids of strain 1KV19T were phosphatidylethanolamine, one unidentified aminolipid and two unidentified polar lipids. The phenotypic, genotypic and chemotaxonomic differences between strain 1KV19T and its phylogenetic relatives indicate that strain 1KV19T should be regarded as representing a novel species in the genus

Lutibacter

, for which the name Lutibacter citreus sp. nov. is proposed. The type strain is 1KV19T (=KCTC 62595T=MCCC 1H00307T).
Description of Eikenella halliae sp. nov. and Eikenella longinqua sp. nov., derived from human clinical materials, emendation of Eikenella exigua Stormo et al. 2019 and emendation of the genus Eikenella to include species which are strict anaerobes
Authors: Bernard Kathryn A. , Burdz Tamara , Wiebe Deborah , Bernier Anne-Marie
Published: April 2020

TheHaemophilus, Aggregatibacter, Cardiobacterium, Eikenella, Kingella(HACEK) group genusEikenellacontained a single species,Eikenella corrodens,for many years. In November 2019,Eikenella exiguawas described after recovery from a brain abscess and blood culture in Norway. Coincidentally, characterization of 22 Gram-negative bacteria resemblingEikenellafrom 17 Canadian patients had been underway. Seven isolates from five patients were conclusively identifiable asE. corrodens. One (NML 120819) was deemed to represent a species of the genusEikenellamost closely related toE. corrodens. Fourteen isolates had 97.6 to 98.8% similarities toE. corrodensby 16S rRNA gene sequencing, forming three distinct groups by genome analyses. The largest contained ten anaerobic isolates from eight patients recovered from blood, brain, bone and other abscesses; upon re-evaluation, this group was found to be most consistent withE. exigua. A second facultatively anaerobic clade consisted of two ocular isolates from one patient and a sinus isolate from a second patient. The third taxon consisted of a single strictly anaerobic blood culture isolate. The novel taxa, likeE. corrodens, were poorly reactive biochemically and difficult to discern from each other phenotypically and chemotaxonomically, including by cellular fatty acids. MALDI-TOF (Bruker) and whole-genome sequencing were used to further characterize isolates. Draft genomes for the strains had similar DNA G+C contents (55.38–58.53 mol%) while sizes varied from 1.82 Mb to 2.54 Mb. We propose here emendations of the genusEikenellaand the speciesEikenella exigua, as well as describingEikenella halliaesp. nov. NML 130454T(=LMG 30894T=NCTC 14180T) andEikenella longinquasp. nov. NML 02-A-017T(=LMG 30896T=NCTC 14179T), on the basis of these findings.
Estimating the effective reproduction number of the 2019-nCoV in China
Authors: Cao Zhidong , Zhang Qingpeng , Lu Xin , Pfeiffer Dirk , Jia Zhongwei , Song Hongbing , Zeng Daniel Dajun
Published: April 2020

We estimate the effective reproduction number for 2019-nCoV based on the daily reported cases from China CDC. The results indicate that 2019-nCoV has a higher effective reproduction number than SARS with a comparable fatality rate.

Article Summary Line

This modeling study indicates that 2019-nCoV has a higher effective reproduction number than SARS with a comparable fatality rate.
Arbidol treatment with reduced mortality of adult patients with COVID-19 in Wuhan, China: a retrospective cohort study
Authors: Liu Qibin , Fang Xuemin , Tian Lu , Vankadari Naveen , Chen Xianxiang , Wang Ke , Li Dan , Dai Xiyong , Xu Feng , Shen Lei , Wang Bing , Yao Li , Peng Peng
Published: April 2020

BACKGROUND

The worldwide COVID-19 pandemic is increasing exponentially and demands an effective and promising therapy at most emergency.

METHODS

We have assembled a cohort consisting 504 hospitalized COVID-19 patients. Detailed information on patients’ characteristics and antiviral medication use during their stay at designated hospitals along with their pre and post treatment results were collected. The study objective is to evaluate the treatment efficacy of Arbidol, together with the concurrent drugs Oseltamivir and Lopinavir/Ritonavir on mortality and lesion absorption based on chest CT scan.

FINDINGS

The overall mortality rate was 15.67% in the cohort. The older age, lower SpO2 level, larger lesion, early admission date, and the presence of pre-existing conditions were associated with higher mortality. After adjusting for the patients age, sex, pre-existing condition, SpO2, lesion size, admission date, hospital, and concurrent antiviral drug use, Arbidol was found promising and associated with reduced mortality. The OR for Arbidol is 0·183 (95% CI, 0·075 to 0·446; P<0·001). Furthermore, Arbidol is also associated with faster lesion absorption after adjusting for patient’s characteristics and concurrent antiviral drug use (P=0·0203).

INTERPRETATION

The broad-spectrum antiviral drug Arbidol was found to be associated with faster
A Fractal kinetics SI model can explain the dynamics of COVID-19 epidemics
Authors: Kosmidis Kosmas , Macheras Panos
Published: April 2020

The COVID-19 pandemic has already had a shocking impact on the lives of everybody on the planet. Here, we present a modification of the classical SI model, the Fractal Kinetics SI model which is in excellent agreement with the disease outbreak data available from the World Health Organization. The fractal kinetic approach that we propose here originates from chemical kinetics and has successfully been used in the past to describe reaction dynamics when imperfect mixing and segregation of the reactants is important and affects the dynamics of the reaction. The model introduces a novel epidemiological parameter, the “fractal” exponenthwhich is introduced in order to account for the self-organization of the societies against the pandemic through social distancing, lockdowns and flight restrictions.