bluuebunny/crossref_metadata_2025 huggingface dataset:
Protein–Protein Interactions Shape Genomic Autoimmunity in the Adaptively Evolving Rhino-Deadlock-Cutoff Complex
Authors: Kelleher Erin S
Published: June 2021

The Piwi-interacting RNA (piRNA) pathway is a genomic defense system that controls the movement of transposable elements (TEs) through transcriptional and post-transcriptional silencing. Although TE defense is critical to ensuring germline genome integrity, it is equally critical that the piRNA pathway avoids autoimmunity in the form of silencing host genes. Ongoing cycles of selection for expanded control of invading TEs, followed by selection for increased specificity to reduce impacts on host genes, are proposed to explain the frequent signatures of adaptive evolution among piRNA pathway proteins. However, empirical tests of this model remain limited, particularly with regards to selection against genomic autoimmunity.

I examined three adaptively evolving piRNA proteins, Rhino, Deadlock, and Cutoff, for evidence of interspecific divergence in autoimmunity between Drosophila melanogaster and Drosophila simulans. I tested a key prediction of the autoimmunity hypothesis that foreign heterospecific piRNA proteins will exhibit enhanced autoimmunity, due to the absence of historical selection against off-target effects. Consistent with this prediction, full-length D. simulans Cutoff, as well as the D. simulans hinge and chromo domains of Rhino, exhibit expanded regulation of D. melanogaster genes. I further demonstrate that this autoimmunity is dependent on known incompatibilities between D. simulans proteins or domains and their interacting partners in D. melanogaster. My observations reveal that the same protein–protein interaction domains that are interfaces of adaptive evolution in Rhino and Cutoff also determine their potential for autoimmunity.
A novel somatic mutation inGNB2provides new insights to the pathogenesis of Sturge–Weber syndrome
Authors: Fjær Roar , Marciniak Katarzyna , Sundnes Olav , Hjorthaug Hanne , Sheng Ying , Hammarström Clara , Sitek Jan Cezary , Vigeland Magnus Dehli , Backe Paul Hoff , Øye Ane-Marte , Fosse Johanna Hol , Stav-Noraas Tor Espen , Uchiyama Yuri , Matsumoto Naomichi , Comi Anne , Pevsner Jonathan , Haraldsen Guttorm , Selmer Kaja Kristine
Published: June 2021

Sturge–Weber syndrome (SWS) is a neurocutaneous disorder characterized by vascular malformations affecting skin, eyes and leptomeninges of the brain, which can lead to glaucoma, seizures and intellectual disability. The discovery of a disease-causing somatic missense mutation in the GNAQ gene, encoding an alpha chain of heterotrimeric G-proteins, has initiated efforts to understand how G-proteins contribute to SWS pathogenesis. The mutation is predominantly detected in endothelial cells and is currently believed to affect downstream MAPK signalling. In this study of six Norwegian patients with classical SWS, we aimed to identify somatic mutations through deep sequencing of DNA from skin biopsies. Surprisingly, one patient was negative for the GNAQ mutation, but instead harbored a somatic mutation in GNB2 (NM_005273.3:c.232A>G, p.Lys78Glu), which encodes a beta chain of the same G-protein complex. The positions of the mutant amino acids in the G-protein are essential for complex reassembly. Therefore, failure of reassembly and continuous signalling is a likely consequence of both mutations. Ectopic expression of mutant proteins in endothelial cells revealed that expression of either mutant reduced cellular proliferation, yet regulated MAPK signalling differently, suggesting that dysregulated MAPK signalling cannot fully explain the SWS phenotype. Instead, both mutants reduced synthesis of Yes-associated protein (YAP), a transcriptional co-activator of the Hippo signalling pathway, suggesting a key role for this pathway in the vascular pathogenesis of SWS. The discovery of the GNB2 mutation sheds novel light on the pathogenesis of SWS and suggests that future research on targets of treatment should be directed towards the YAP, rather than the MAPK, signalling pathway.
Possible future scenarios in the gateways to the Arctic for Subarctic and Arctic marine systems: II. prey resources, food webs, fish, and fisheries
Authors: Mueter Franz J , Planque Benjamin , Hunt George L , Alabia Irene D , Hirawake Toru , Eisner Lisa , Dalpadado Padmini , Chierici Melissa , Drinkwater Kenneth F , Harada Naomi , Arneberg Per , Saitoh Sei-Ichi
Published: June 2021

Climate change impacts are pronounced at high latitudes, where warming, reduced sea-ice-cover, and ocean acidification affect marine ecosystems. We review climate change impacts on two major gateways into the Arctic: the Bering and Chukchi seas in the Pacific and the Barents Sea and Fram Strait in the Atlantic. We present scenarios of how changes in the physical environment and prey resources may affect commercial fish populations and fisheries in these high-latitude systems to help managers and stakeholders think about possible futures. Predicted impacts include shifts in the spatial distribution of boreal species, a shift from larger, lipid-rich zooplankton to smaller, less nutritious prey, with detrimental effects on fishes that depend on high-lipid prey for overwinter survival, shifts from benthic- to pelagic-dominated food webs with implications for upper trophic levels, and reduced survival of commercially important shellfish in waters that are increasingly acidic. Predicted changes are expected to result in disruptions to existing fisheries, the emergence of new fisheries, new challenges for managing transboundary stocks, and possible conflicts among resource users. Some impacts may be irreversible, more severe, or occur more frequently under anthropogenic climate change than impacts associated with natural variability, posing additional management challenges.
Is SARS-CoV-2 Infection a Risk Factor for Early Pregnancy Loss? ACE2 and TMPRSS2 Coexpression and Persistent Replicative Infection in Primitive Trophoblast
Authors: Zhou Jie , Choi Sehee , Liu Heidi , Zhang Jialin , Tian Yuchen , Edlow Andrea G , Ezashi Toshihiko , Roberts R Michael , Ma Wenjun , Schust Danny J
Published: June 2021

Background

SARS-CoV-2 infection in term placenta is rare. However, growing evidence suggests that susceptibility of the human placenta to infection may vary by gestational age and pathogen. For several viral infections, susceptibility appears to be greatest during early gestation. Peri-implantation placental infections that result in pre-clinical pregnancy loss would typically go undetected. Little is known about the effects of SARS-CoV-2 on the peri-implantation human placenta since this time in pregnancy can only be modeled in vitro.

Methods

We used a human embryonic stem cell (hESC)-derived model of peri-implantation placental development to assess patterns of ACE2 and TMPRSS2 transcription and protein expression in primitive trophoblast. We then infected the same trophoblast cell model with a clinical isolate of SARS-CoV-2 and documented infection dynamics.

Results

ACE2 and TMPRSS2 were transcribed and translated in hESC-derived trophoblast, with preferential expression in syncytialized cells. These same cells supported replicative and persistent infection by SARS-CoV-2, while non-syncytialized trophoblast cells in the same cultures did not.

Conclusions

Co-expression of ACE2 and TMPRSS2 in hESC-derived trophoblast and the robust and replicative infection limited to syncytiotrophoblast equivalents support the hypothesis that increased viral susceptibility may be a defining characteristic of primitive trophoblast.
Safety concerns with glass particle contamination: improving the standard guidelines for preparing medication injections
Authors: Chiannilkulchai Natthacha , Kejkornkaew Siranee
Published: June 2021

Background

Glass ampoules are widely used to contain injection medications because of their properties. However, the existing literature reports that glass particle contamination is found in opening glass ampoules. To date, nursing practice standards on this issue have not gained attention in terms of the manual breaking methods generally used for opening ampoules in a clinical setting that can minimize the risk of glass particle contamination and, therefore, increase patient safety.

Objective

This study aimed to compare manual breaking methods commonly used to open ampoules in clinical practice that affected the number of glass particles and to identify the factors influencing glass particle contamination.

Methods

We used a comparative research design to evaluate the manual breaking methods for opening medication ampoules among 56 registered nurses from diverse clinical areas in a university hospital. Each participant broke 12 ampoules in two sizes using six methods, each method combined with wrapping material and one breaking direction. We measured the number of glass particles in five sizes for each method and the factors influencing glass particle contamination.

Results

In total, 449 of 672 ampoules were contaminated with glass particles. Breaking the ampoule with a cotton ball (partial ampoule neck wrapping) from an outward direction resulted in the fewest glass particles, while breaking the ampoule with a gauze pad (entire ampoule neck wrapping) from an inward direction resulted in the most glass particles. Breaking method, ampoule size and clinical experience significantly influence glass particle contamination (P < 0.05).

Conclusions

The method (wrapping technique and breaking direction) that nurses use to break ampoules affects the number of glass particles. Therefore, improving the standard guidelines for preparing medication injections and training in breaking methods for opening ampoules is essential.
Towards gender equity in artificial intelligence and machine learning applications in dermatology
Authors: Lee Michelle S , Guo Lisa N , Nambudiri Vinod E
Published: June 2021

There has been increased excitement around the use of machine learning (ML) and artificial intelligence (AI) in dermatology for the diagnosis of skin cancers and assessment of other dermatologic conditions. As these technologies continue to expand, it is essential to ensure they do not create or widen sex- and gender-based disparities in care. While desirable bias may result from the explicit inclusion of sex or gender in diagnostic criteria of diseases with gender-based differences, undesirable biases can result from usage of datasets with an underrepresentation of certain groups. We believe that sex and gender differences should be taken into consideration in ML/AI algorithms in dermatology because there are important differences in the epidemiology and clinical presentation of dermatologic conditions including skin cancers, sex-specific cancers, and autoimmune conditions. We present recommendations for ensuring sex and gender equity in the development of ML/AI tools in dermatology to increase desirable bias and avoid undesirable bias.
Evolutionary and Ecological Drivers Shape the Emergence and Extinction of Foot-and-Mouth Disease Virus Lineages
Authors: Di Nardo Antonello , Ferretti Luca , Wadsworth Jemma , Mioulet Valerie , Gelman Boris , Karniely Sharon , Scherbakov Alexey , Ziay Ghulam , Özyörük Fuat , Parlak Ünal , Tuncer-Göktuna Pelin , Hassanzadeh Reza , Khalaj Mehdi , Dastoor Seyed Mohsen , Abdollahi Darab , Khan Ehtisham-ul-Haq , Afzal Muhammad , Hussain Manzoor , Knowles Nick J , King Donald P
Published: June 2021

Livestock farming across the world is constantly threatened by the evolutionary turnover of foot-and-mouth disease virus (FMDV) strains in endemic systems, the underlying dynamics of which remain to be elucidated. Here, we map the eco-evolutionary landscape of cocirculating FMDV lineages within an important endemic virus pool encompassing Western, Central, and parts of Southern Asia, reconstructing the evolutionary history and spatial dynamics over the last 20 years that shape the current epidemiological situation. We demonstrate that new FMDV variants periodically emerge from Southern Asia, precipitating waves of virus incursions that systematically travel in a westerly direction. We evidence how metapopulation dynamics drive the emergence and extinction of spatially structured virus populations, and how transmission in different host species regulates the evolutionary space of virus serotypes. Our work provides the first integrative framework that defines coevolutionary signatures of FMDV in regional contexts to help understand the complex interplay between virus phenotypes, host characteristics, and key epidemiological determinants of transmission that drive FMDV evolution in endemic settings.
Acetylation of the CspA family protein CspC controls the type III secretion system through translational regulation ofexsAinPseudomonas aeruginosa
Authors: Li Shouyi , Weng Yuding , Li Xiaoxiao , Yue Zhuo , Chai Zhouyi , Zhang Xinxin , Gong Xuetao , Pan Xiaolei , Jin Yongxin , Bai Fang , Cheng Zhihui , Wu Weihui
Published: June 2021

The ability to fine tune global gene expression in response to host environment is critical for the virulence of pathogenic bacteria. The host temperature is exploited by the bacteria as a cue for triggering virulence gene expression. However, little is known about the mechanism employed by Pseudomonas aeruginosa to response to host body temperature. CspA family proteins are RNA chaperones that modulate gene expression. Here we explored the functions of P. aeruginosa CspA family proteins and found that CspC (PA0456) controls the bacterial virulence. Combining transcriptomic analyses, RNA-immunoprecipitation and high-throughput sequencing (RIP-Seq), we demonstrated that CspC represses the type III secretion system (T3SS) by binding to the 5′ untranslated region of the mRNA of exsA, which encodes the T3SS master regulatory protein. We further demonstrated that acetylation at K41 of the CspC reduces its affinity to nucleic acids. Shifting the culture temperature from 25°C to 37°C or infection of mouse lung increased the CspC acetylation, which derepressed the expression of the T3SS genes, resulting in elevated virulence. Overall, our results identified the regulatory targets of CspC and revealed a regulatory mechanism of the T3SS in response to temperature shift and host in vivo environment.
Architecture and evolution of subtelomeres in the unicellular green algaChlamydomonas reinhardtii
Authors: Chaux-Jukic Frédéric , O’Donnell Samuel , Craig Rory J , Eberhard Stephan , Vallon Olivier , Xu Zhou
Published: June 2021

In most eukaryotes, subtelomeres are dynamic genomic regions populated by multi-copy sequences of different origins, which can promote segmental duplications and chromosomal rearrangements. However, their repetitive nature has complicated the efforts to sequence them, analyse their structure and infer how they evolved. Here, we use recent genome assemblies of Chlamydomonas reinhardtii based on long-read sequencing to comprehensively describe the subtelomere architecture of the 17 chromosomes of this model unicellular green alga. We identify three main repeated elements present at subtelomeres, which we call Sultan, Subtile and Suber, alongside three chromosome extremities with ribosomal DNA as the only identified component of their subtelomeres. The most common architecture, present in 27 out of 34 subtelomeres, is a heterochromatic array of Sultan elements adjacent to the telomere, followed by a transcribed Spacer sequence, a G-rich microsatellite and transposable elements. Sequence similarity analyses suggest that Sultan elements underwent segmental duplications within each subtelomere and rearranged between subtelomeres at a much lower frequency. Analysis of other green algae reveals species-specific repeated elements that are shared across subtelomeres, with an overall organization similar to C. reinhardtii. This work uncovers the complexity and evolution of subtelomere architecture in green algae.
Less is more: wiring-economical modular networks support self-sustained firing-economical neural avalanches for efficient processing
Authors: Liang Junhao , Wang Sheng-Jun , Zhou Changsong
Published: June 2021

The brain network is notably cost-efficient, while the fundamental physical and dynamic mechanisms underlying its economical optimization in network structure and activity have not been determined. In this study, we investigate the intricate cost-efficient interplay between structure and dynamics in biologically plausible spatial modular neuronal network models. We observe that critical avalanche states from excitation-inhibition balance under modular network topology with less wiring cost can also achieve lower costs in firing but with strongly enhanced response sensitivity to stimuli. We derive mean-field equations that govern the macroscopic network dynamics through a novel approximate theory. The mechanism of low firing cost and stronger response in the form of critical avalanches is explained as a proximity to a Hopf bifurcation of the modules when increasing their connection density. Our work reveals the generic mechanism underlying the cost-efficient modular organization and critical dynamics widely observed in neural systems, providing insights into brain-inspired efficient computational designs.
Sacroplasty Augmentation of Instrumented Pelvic Reconstruction After High Sacrectomy: A Technical Case Report
Authors: Sacino Amanda N , Pairojboriboon Sutipat , Suk Ian , Lubelski Daniel , Yang Robin , Sciubba Daniel M , Lo Sheng-fu Larry
Published: June 2021

BACKGROUND AND IMPORTANCE

En bloc resection of sacral tumors is the most effective treatment to help prevent recurrence. Sacrectomy, however, can be destabilizing, depending on the extent of resection. Various surgical techniques for improving stability and enabling early ambulation have been proposed.

CLINICAL PRESENTATION

Here, we report a case in which we use PMMA (poly[methyl methacrylate]) to augment pelvic instrumentation to improve mechanical stability after sacrectomy for en bloc resection of a solitary fibrous tumor.

CONCLUSION

We highlight the use of sacroplasty augmentation of pelvic ring reconstruction to provide biomechanical stability without the need for fusion of any mobile spine segments, which allowed for early patient ambulation and no appreciable loss of range of motion or mobility.
Radiofrequency Ablation for Movement Disorders: Risk Factors for Intracerebral Hemorrhage, a Retrospective Analysis
Authors: Horisawa Shiro , Fukui Atsushi , Nonaka Taku , Kawamata Takakazu , Taira Takaomi
Published: June 2021

BACKGROUND

One of the greatest concerns associated with radiofrequency ablation is intracerebral hemorrhage (ICH). However, the majority of previous studies have mainly evaluated Parkinson disease patients with ablation of the globus pallidus internus (GPi).

OBJECTIVE

To investigate the hemorrhagic risk associated with radiofrequency ablation using ventro-oral (Vo) nucleus, ventral intermediate (Vim) nucleus, GPi, and pallidothalamic tract.

METHODS

Radiofrequency ablations for movement disorders from 2012 to 2019 at our institution were retrospectively analyzed. Multivariate analyses were performed to evaluate associations between potential risk factors and ICH.

RESULTS

A total of 558 patients underwent 721 stereotactic radiofrequency ablations for movement disorders. Among 558 patients, 356 had dystonia, 111 had essential tremor, and 51 had Parkinson disease. Among 721 procedures, the stereotactic targets used in this study were as follows: Vo: 230; Vim: 199; GPi: 172; pallidothalamic tract: 102; Vim/Vo: 18. ICH occurred in 37 patients (5.1%, 33 with dystonia and 4 with essential tremor). Symptomatic ICH developed in 3 Vo nuclei (1.3%), 3 Vim nuclei (1.5%), and 2 GPi (1.2%). Hypertension (odds ratio = 2.69, P = .0013), higher number of lesions (odds ratio = 1.23, P = .0221), and younger age (odds ratio = 1.04, P = .0055) were significant risk factors for ICH associated with radiofrequency ablation.

CONCLUSION

The present study revealed that younger age, higher number of lesions, and history of hypertension were independent risk factors for ICH associated with stereotactic radiofrequency ablation.
Computational methods in social neuroscience: recent advances, new tools and future directions
Authors: Parkinson Carolyn
Published: June 2021

Recent years have seen a surge of exciting developments in the computational tools available to social neuroscientists. This paper highlights and synthesizes recent advances that have been enabled by the application of such tools, as well as methodological innovations likely to be of interest and utility to social neuroscientists, but that have been concentrated in other sub-fields. Papers in this special issue are emphasized—many of which contain instructive materials (e.g. tutorials and code) for researchers new to the highlighted methods. These include approaches for modeling social decisions, characterizing multivariate neural response patterns at varying spatial scales, using decoded neurofeedback to draw causal links between specific neural response patterns and psychological and behavioral phenomena, examining time-varying patterns of connectivity between brain regions, and characterizing the social networks in which social thought and behavior unfold in everyday life. By combining computational methods for characterizing participants’ rich social environments—at the levels of stimuli, paradigms and the webs of social relationships that surround people—with those for capturing the psychological processes that undergird social behavior and the wealth of information contained in neuroimaging datasets, social neuroscientists can gain new insights into how people create, understand and navigate their complex social worlds.
Re-thinking administrative unworkability in discretionary trusts
Authors: Brown James , Pawlowski Mark
Published: June 2021

This article seeks to explain the current doctrine of administrative unworkability as it applies to discretionary trusts in the context of English trust law with a view to identifying some of its problems and suggesting a reframing of the doctrine in terms of economic viability in the light of modern information technology.
Potential Electron Transfer Protein Complexes During the Initiation of Polychlorinated Biphenyl Degradation Investigated by Small‐Angle X‐ray Scattering
Authors: Colbert Christopher , Jensen Jaime , LeVahn Benjamin , Staskywicz Zachery , Glover Karen , Neau David , Chakravarthy Srinivas , Sinha Sangita
Published: June 2021

The first step in the oxidative degradation of the persistent environmental pollutants polychlorinated biphenyls (PCBs) by the aerobic microbe Pandoraea pnomenusa B‐356 is the stereo‐ and regio‐selective insertion of both atoms from molecular oxygen into the aromatic substrate to form a cis‐dihydrodiol. This reaction is catalyzed by biphenyl 2,3‐dioxygenase (BPDO), Rieske Oxygenase containing a Rieske 2Fe‐2S cluster and a catalytic mononuclear Fe2+ atom. Electrons, required to activate molecular oxygen during hydroxylation of the aromatic substrate, are transferred to BPDO from NADH via a short electron transfer chain consisting of a FAD‐dependent ferredoxin reductase (BphG) and a 2Fe‐2S cluster containing Rieske‐type ferredoxin (BphF). To understand the solution characteristics of the potential electron transfer complexes, we performed size exclusion chromatography coupled with small‐angle X‐ray scattering (SEC‐SAXS) to determine the molecular envelopes of BphG in complex with BphF, as well as BphF in complex with BPDO. These envelopes are compared to the current crystallographic model of BphA3:BphA4 from Acidovorax sp. strain KKS102 and our predicted model for BphF:BPDO. These observations provide insights into the protein‐protein associations for intermolecular electron transfer during the initiation of PCB biodegradation.

Support or Funding Information

Funded by NSF ND EPSCoR DDA #FAR0025216 to JLJ; NIH NINDS 1R03 NS090939 and NSF MCB‐1413525 to SCS; NIH NIGMS 1R15 GM113227, NIH NCRR 2P20 RR015566, and NIH NIGMS P30 GM103332 to CLC.
Hyaluronan signals release and nuclear accumulation of WWOX and Smad from membrane Hyal‐2
Authors: Chang Nan‐Shan
Published: June 2021

A prerequisite condition prior to metastasis is the dramatic production of transforming growth factor beta (TGF‐β), hyaluronan and hyaluronidases by cancer cells. Here it is determined that knockdown of tumor suppressor WWOX (also known as WOX1 or FOR) significantly upregulates the expression of hyaluronidases Hyal‐1 and Hyal‐2 and enhances the metastatic potential cancer cells in vivo. In contrast, overexpressed WWOX suppresses the expression of Hyal‐1 and Hyal‐2 and cell migration in vivo. Hyaluronan binds membrane Hyal‐2, followed by recruiting WWOX and Smad4, and then the Hyal‐2/WWOX/Smad4 complex relocating to the nuclei. Overly activated SMAD responsive element causes apoptosis. Small interfering RNA (siRNA)‐targeting WWOX abolished overexpressed Smad4‐mediated apoptosis. Notably, stimulating membrane Hyal‐2 with a specific antibody or modified hyaluronan induces anticancer response in vivo. Together, hyaluronan invokes a novel signal pathway that causes activation of WWOX and Smad4 from membrane Hyal‐2, and this may invoke an innate mechanism in blocking cancer growth.

Support or Funding Information

AHA, DoD and MOST, Taiwan
Feasibility of an Online Nutrition Education eLearning Program from the Perspectives of Peer Nutrition Educators and Low‐Income Individuals in Georgia
Authors: Stotz Sarah , Lee Jung Sun , Rong Hui
Published: June 2021

The intent of this project was to examine peer nutrition educators and low‐income Georgians’ perceptions of an innovative nutrition education eLearning program titled Food eTalk. Four focus groups were conducted in a convenience sample (n=14, age 49.6 ± 9.7 years, 93% female, 50% black) of peer educators and low‐income Georgians. The focus group interviews were guided by the constructivist theory and the semi‐structured interview guide focused on three themes: accessibility, content, and literacy. To facilitate discussion, a prototype of the online nutrition education eLearning program, titled Food eTalk was shown during each focus group. The Food eTalk prototype included two lessons, each with didactic nutrition education information and interactive activities/learning games. Focus group interviews were digitally recorded, transcribed verbatim, and coded using Atlas.ti software and the constant comparative method. Neither peer educators nor low‐income participants indicated access to the Internet as a barrier, as mobile‐based access was considered ubiquitous among the target audience. Comfort navigating the Internet was a common concern specifically for individuals over 30 years old. Desired content included: cooking videos, recipes, and basic food preparation. Low‐income participants mentioned food safety in terms of animal‐based food products as an area for desired education whereas peer educators focused on the need for education to include food budgeting and meal planning. Peer educators and low‐income participants suggested that a government mandate for SNAP beneficiaries to complete Food eTalk would be the best motivation and incentive to use the program. Peer educators and low‐income Georgians perceived Food eTalk would be a well‐ accepted and feasible form of nutrition education for the target audience. Findings from this study will inform the user‐centered development of Food eTalk.

Support or Funding Information

This study was funded by USDA SNAP‐Ed
Cross‐Validation of Recent and Longstanding Resting Metabolic Rate Prediction Equations
Authors: Flack Kyle D , Siders William A , Johnson LuAnn , Roemmich James N
Published: June 2021

Resting metabolic rate (RMR) measurement is time consuming and requires specialized equipment. Prediction equations provide an easy method to estimate RMR; however, their accuracy likely varies across individuals. Understanding the factors that influence predicted RMR accuracy at the individual level will help to revise existing or develop new equations that are more accurate. The objective of the present study was to test the validity of established (Harris‐Benedict, WHO, Mifflin‐St. Jeor) and contemporary (3 meta equations of Sabounchi and colleagues, 1 equation of Nelson and colleagues, 1 by Wang and colleagues) RMR prediction equations in healthy adults.

Design

Predicted RMR was tested for agreement with indirect calorimetry. Men and women (n=30) age 18–65y from Grand Forks, ND were recruited and included for analysis during Spring/Summer 2014. Participants were nonobese to obese, primarly Caucasian and a representive sample of a healthy, free‐living population. The main outcome measure was bias between measured (indirect calorimetry) and predicted RMR. The methods of Bland and Altman were employed to determine mean bias (predicted minus measured RMR, kcal/day) and limits of agreement between predicted and measured RMR. Repeated measures ANOVA was utilized to test for differences in RMR predicted from each equation versus the measured RMR. Mean bias was lowest for the Harris‐Benedict (4 ± (2 SD) 386 kcal/24 hrs) and WHO (25 ± 402 kcal/24 hrs) equations and these mean predicted RMR did not differ from measured. Mean RMR predictions from all other equations significantly differed from indirect calorimetry. The 2 SD limits of agreement were moderate or large for all equations tested ranging from 282 to 445 kcal/24 hrs. Prediction bias was positively associated with the magnitude of RMR and with FFM. In conclusion, the traditional Harris‐Benedict and WHO equations were the most accurate. However, even these equations did not perform well at the individual level. As FFM increased, the prediction equations further underestimated RMR.

Support or Funding Information

Support: USDA‐ARS 3062‐51000‐051‐00D
Apo‐10′‐Lycopenoic acid Inhibits Cancer Cell Migration and Angiogenesis by Suppressing Lamellipodia Formation
Authors: Miao Benchun , Fu Xueyan , Wang Xiang‐Dong
Published: June 2021

Epidemiologic studies have shown that an increase in the dietary intake of tomato and tomato‐based products or higher blood levels of lycopene, is associated with a reduced risk of cancer. Apolycopenoids can be produced by either lycopene cleavage through carotenoid cleavage enzymes, such as beta‐carotene 9′,10′‐oxygenase or the consumption of tomato and tomato products, such as tomato juice. We have previously shown that apo‐10′‐lycopenoic acid, a relative stable derivative of apo‐10′‐lycopenoids, could inhibit tumorigenesis in both lung cancer and liver cancer animal models. To further elucidate the potential mechanisms for the chemopreventive effect of apo‐10′‐lycopenoic acid against cancer development, we examined the ability of apo‐10′‐lycopenoic acid on migration of cancer cells (A549 and HuH7 cells) and endothelial cells (HMEC‐1) using cell migration assays, and angiogenesis using endothelial tube formation and aortic ring assays. We demonstrated that apo‐10′‐lycopenoic acid, in dose‐dependent manner, is effective at inhibiting migration and invasion of both cancer and endothelial cells by suppressing actin remodeling and ruffling/lamellipodia formation. In addition, apo‐10‐lycopenoic acid treatment results in suppression of angiogenesis in both tube formation and aortic ring assays. Apo‐10‐lycopenoic acid also inhibits matrix metalloproteinase‐2 (MMP‐2) expression and activation in A549 cells. Overall, these data demonstrate that apo‐10′‐lycopenoic acid can inhibit cancer cell motility and angiogenesis which could be one of the potential mechanisms for the chemopreventive effect of apo‐10′‐lycopenoic acid against tumorigenesis.

Support or Funding Information

Supported by USDA/ARS (58‐1950‐0014)
Spirulina platensis organic extract increases spare respiratory capacity in RAW 264.7 macrophages to exert an anti‐inflammatory effect
Authors: Pham Tho X , Lee Ji‐Young
Published: June 2021

Recent evidence supports that crosstalk between energy metabolism and inflammatory processes is a critical determinant for macrophage phenotype. Macrophage energy metabolism greatly influences their activation state. For example, M1, pro‐inflammatory macrophages largely depend on glycolysis while M2, anti‐inflammatory macrophages prefer mitochondrial oxidative phosphorylation (OXPHOS) for their energy generation. We previously demonstrated that organic extract of Spirulina platensis (SPE), a blue‐green algae, exerts a potent anti‐inflammatory effect in vitro and ex vivo. Our recent study also suggests that the anti‐inflammatory effect of SPE is at least partly attributable to the induction of an endotoxin tolerance‐like state in macrophages. Interestingly, although SPE repressed LPS‐induced pro‐inflammatory gene expression as potently as endotoxin tolerant (ET) macrophages, there were some differences between SPE‐treated and ET macrophages. The objective of this study was to determine if SPE alters macrophage energy metabolism to exert its anti‐inflammatory effect in addition to its role in endotoxin tolerance. To determine the energy phenotype, we measured oxygen consumption rate (OCR) and extra cellular acidification rate (ECAR) of naïve, SPE‐treated, and ET macrophages by XF Mito Stress tests using a Seahorse XFe24 Analyzer. Treatment of RAW 264.7 macrophages with 25 mg/mL of SPE or endotoxin tolerization with 10 ng/mL of lipopolysaccharide (LPS) for 12 h increased basal ECAR compared to naïve cells with concomitant increases in the expression of interleukin‐1β and tumor necrosis factor‐α, suggesting that both SPE and LPS activated macrophages to a certain degree. The basal OCR values of naïve cells were the highest, followed by SPE‐treated and then ET cells, which indicates that SPE and LPS decreased cell's dependence on OXPHOS. Interestingly, RAW 264.7 macrophages treated with 25 mg/mL of SPE had the highest spare respiratory capacity (SRC), which is a measure of how much ATP may be produced through OXPHOS in response to a sudden increase in energy demand. When naïve, SPE‐pretreated and ET RAW 264.7 macrophages were stimulated with 100 ng/mL of LPS for 12 h, the SRC was significantly reduced in all treatment groups. During LPS‐stimulation, SPE‐pretreated cells may be better off to meet the energy demands of LPS stimulation as SPE pretreatment significantly increased the SRC. In conclusion, we found that SPE‐pretreated macrophage, but not ET macrophages, had increased the SRC, which may contribute to the potent anti‐inflammatory effects of SPE in macrophages.

Support or Funding Information

USDA AFRI (2014‐01870)
Constitutive phosphorylation of STAT3 by the human serotonin 2C receptor
Authors: Curtis Mary E , Fears Letimicia , Ivy Michael , Fentress Hugh
Published: June 2021

Serotonin (5‐HT) is a modulatory neurotransmitter in the central nervous system that plays a role in many physiological responses by binding to 16 different receptor subtypes. The 5‐HT2C receptor subtype, a 7‐transmembrane spanning G protein‐coupled receptor, is involved in neuronal excitability, spatial learning, mood, executive function, glucose and energy homeostasis, and appetite. This receptor activates signaling pathways downstream of the Gαq/11 protein, as well as other intracellular proteins that activate G protein‐independent pathways. The structurally similar 5‐HT2A receptor can additionally activate the JAK/STAT pathway, and has been shown to do so following chronic treatment with the atypical antipsychotic and 5‐HT2A and 5‐HT2C receptor antagonist, olanzapine. The purpose of the present study to was to investigate the ability of the 5‐HT2C receptor to activate the JAK/STAT pathway. Human Embryonic Kidney (HEK) 293 cells were transfected with the human 5‐HT2C receptor and stable cell lines were generated. Cells were treated with vehicle, serotonin, olanzapine, or the 5‐HT2CR inverse agonist, SB206553. Proteins were separated by SDS‐PAGE and levels of phosphorylated JAK2 and STAT3 were analyzed via immunoblot. Constitutive phosphorylation of STAT3 was observed in cells containing the 5‐HT2C receptor, while STAT3 phosphorylation was not observed in untransfected cells or cells treated with SB206553 or olanzapine. Treatment with 5‐HT increased the levels of phosphorylated STAT3, while JAK2 phosphorylation was unaffected in all treatment groups. This indicates that agonist binding enhances phosphorylation of STAT3 independently of JAK2 activation. This is the first report of the 5‐HT2C receptor activating this pathway and suggests that this receptor may be involved in growth, cell differentiation, the immune response, and transcription of other STAT activated genes. Future studies will examine activation of this pathway in the adult mouse brain and in the presence of other agonists and antagonists.

Support or Funding Information

Supported by the National Science Foundation HRD‐1238723 to Hugh. M. Fentress
A Case of Mistaken Identity: Are Reactive Oxygen Species Actually Reactive Sulfide Species?
Authors: Olson Kenneth R , Gao Yan , Huang Evelyn , Arif Maaz , Arora Nitin , Divietro Alexander , Patel Shivali , Deleon Eric R
Published: June 2021

Stepwise one‐electron reduction of oxygen to water produces reactive oxygen species (ROS), namely peroxide (H2O2), superoxide (O2.−) and the hydroxyl radical (HO.−). These are chemically and biochemically similar to reactive sulfide species (RSS) that are derived from one‐electron oxidation of hydrogen sulfide (H2S) to elemental sulfur, namely persulfide (H2S2), “supersulfide” (S2.−) and the thiyl radical (HS.−). H2S is also reactive and can act as a RSS. Both ROS and RSS are endogenously generated, signal via reactive protein thiols and have common effector targets. Given these similarities, we hypothesized that extant methods for measuring the former would also detect the latter. Here we compared the sensitivity of five methods commonly employed for measuring ROS to both ROS (H2O2 and superoxide as KO2), and to RSS (H2S, H2Sn where n=2–8, H2S2, H2S3 and H2S4. The methods examined were redox‐sensitive green fluorescent protein (roGFP), 2′, 7′‐dihydrodichlorofluorescein (DCF), MitoSox Red, Amplex Red and H2O2 amperometric electrodes. All methods detected RSS and were as or more sensitive to RSS than they were to ROS. roGFP, arguably the “gold standard” for ROS measurement, was over two‐hundred fold more sensitive to H2Sn (n=2–8) than H2O2. Likewise, ROS and RSS produced dose‐dependent increases in 10 ìM DCF fluorescence, with high (1, 3 mM) H2S giving the most rapid increase in DCF fluorescence. H2O2 and H2S were essentially equipotent, whereas KO2 was considerably less efficacious. Lastly, amperometric H2O2 sensors were nearly 30 times more sensitive to H2S than to H2O2 and two or three times more sensitive to H2S2, H2S3 and H2S4 than to H2O2. The responses of roGFP and DCF to RSS were not diminished by hypoxia (Po2 <4 mmHg) which indicates that they did not involve ROS generation from RSS. The estimated daily production of RSS by cysteine catabolism is similar to estimated ROS production from oxygen consumption, but may exceed it if ROS production is overestimated due to RSS interference. These findings suggest that RSS are far more prevalent in intracellular signaling than previously appreciated and that the contribution of ROS may be overestimated. This conclusion is further supported by the fact that both RSS and antioxidant mechanisms have been present since the origin of life nearly 4 billion years ago, long before the rise in environmental oxygen 600 million years ago. Although ROS are assumed to be the most biologically relevant oxidants, our results question this paradigm. We also anticipate our findings will direct attention toward development of novel and clinically relevant anti‐(RSS)‐oxidants.

Support or Funding Information

NSF IOS‐144‐6310 (KRO), NSF GRFP DGE‐131‐3583 (ERD)
Effects of Hypoxia on intracellular H2S and Polysulfides: Implications in O2 Sensing
Authors: Deleon Eric R , Huang Evelyn , Gao Yan , Olson Kenneth R
Published: June 2021

The mechanism(s) by which cells detect hypoxia and transduce this into appropriate homeostatic responses is a contentious issue. Vascular oxygen sensing is generally attributed to hypoxic generation of reactive oxygen species (ROS). However, we recently found that methods commonly employed to measure ROS cannot distinguish between ROS and reactive sulfur species (RSS) and that RSS and ROS have similar effects on intracellular redox status. Our previous studies suggest that metabolism of hydrogen sulfide (H2S) is the O2 sensor, as H2S mimics hypoxia in numerous systems and H2S metabolism is inversely coupled to O2 availability at physiological levels. In the present study we measure intracellular production of H2S and H2Sn using 7‐Azido‐4‐Methylcoumarin (AzMC) and 3,6‐DI(O‐Thiosalicyl) (SSP4), respectively in HEK‐293 cells and bovine pulmonary artery smooth muscle cells (BPASMC) under both normoxic (21% O2) and hypoxic (0.5% O2) conditions over a 48 hr period. In addition, we attempted to augment H2S and H2Sn production via the known intracellular pathways through addition of substrates (to increase production) and inhibitors (to decrease production). We found that hypoxia increased AzMC fluorescence by 50%, but did not affect SSP4 fluorescence. In normoxia, AzMC fluorescence did not change, whereas SSP4 fluorescence increased two‐fold. These results suggest that hypoxia increases intracellular H2S concentration and concomitantly prevents further the increase in H2Sn concentration. Intracellular H2S and H2Sn was not affected by either cysteine or cystine (10 and 100 uM). Both propargylglycine (10 mM), an inhibitor of cystathionine ã‐lyase and aspartate (1 mM) an inhibitor of cysteine aminotransferase reduced hypoxia stimulated AzMC fluorescence in HEK‐293 cells. Aminooxyacetate, an inhibitor of cystathionione â‐synthase, greatly increased AzMC fluorescence in HEK‐293 cells in normoxia and hypoxia. These are the first measurements of oxygen‐dependent changes in intracellular H2S and H2Sn in living cells and they support our hypothesis that RSS are directly coupled to O2 sensing.

Support or Funding Information

NSF Grant IOS‐144‐6310 (KRO), NSF GRFP DGE‐131‐3583 (ERD)
DLP1‐dependent mitochondrial fragmentation mediates heat shock‐induced injury in mouse C2C12 skeletal muscle cells
Authors: Yu Tianzheng , Deuster Patricia , Chen Yifan
Published: June 2021

Mitochondria regulate cell survival and coordinate cell‐wide stress responses by constantly changing their shapes to alterations in energy demands and/or environmental stimuli. In this study, we investigated the role of mitochondrial morphology in heat‐induced injury in mouse C2C12 skeletal muscle cells. Exposure to heat for 4 hours significantly reduced cell viability (96 ± 3 % at 37 °C vs. 62 ± 6 % at 43 °C, p < 0.01). Mitochondrial morphology analysis revealed that heat exposure caused rapid mitochondrial fragmentation (cells contained fragmented mitochondria: 9 ± 1 %, 47 ± 4 % and 91 ± 2 % at 0, 15 and 30 min, respectively). To identify the molecular mechanism(s) underlying heat‐induced mitochondrial fragmentation, we performed immunoblotting and immunostaining for mitochondrial fission and fusion proteins. Heat exposure increased mitochondrial translocation of fission factor dynamin‐like protein 1 (DLP1). Furthermore, loss of mitochondrial membrane potential and subsequent cleavage of mitochondrial fusion protein optic atrophy 1 (OPA1) in C2C12 cells were noted following heat exposure. Pretreatment with DLP1 chemical inhibitor Mdivi‐1 or knockdown of DLP1 gene expression reduced mitochondrial fragmentation, prevented loss of mitochondrial membrane potential, and improved viability of C2C12 cells in response to heat shock. These results suggest that heat stress is associated with altered mitochondrial dynamics and DLP1‐mediated mitochondrial fission serves a role in heat‐induced cell injury.

Support or Funding Information

Supported by Congressionally Directed Medical Research Programs W81XWH‐14‐2‐0133
Prior exercise and changes in plasma volume cause differential baroreflex responses to head‐up tilt
Authors: Charkoudian Nisha , Kenefick Robert W. , Caruso Elizabeth M , Luippold Adam J. , Heavens Kristen R. , Cheuvront Samuel N.
Published: June 2021

Prior exercise and loss of plasma volume each independently cause cardiovascular changes that can result in hypotension and orthostatic intolerance (OI). However, the profile of volume regulatory factors differs substantially between these conditions. We hypothesized that during isotonic hypovolemia (diuretic‐induced, 3.01±0.23 % body weight loss; n = 6, DIUR), sympathetic neural responses to tilt would be greater than in euhydrated, normothermic subjects (n = 6, EX) who had previously exercised in dry heat (40°C). We measured heart rate (HR), blood pressure (BP) and muscle sympathetic nerve activity (MSNA) during supine rest and head‐up tilt (HUT) to 30 and 45°. Plasma volume decreased 10.2±4.4% in DIUR, and 3.4±3.6% in EX (P<0.01). Supine HR was higher in EX compared to DIUR (82±12 vs. 64±9 beats/min, P < 0.01). However, supine MSNA was not different between groups, either as bursts/min (EX: 24±9 vs. DIUR: 24±10, P>0.05) or bursts/100hb (EX: 30±11 vs. DIUR: 40±19, P>0.05). In contrast to our hypothesis, MSNA responses to tilt were smaller in the DIUR group, both at 30° (EX: 12±7 vs. DIUR 3±4 bursts/100hb, P < 0.02) and at 45°HUT (deltas: EX: 14±8 vs. 3±3 bursts/100hb, P < 0.02). HR responses to tilt were larger in the DIUR group (P < 0.05). Systolic BP tended to be lower in DIUR during tilt (P = 0.05), but diastolic and mean BP values were not different between groups. These data provide an interesting example of differential responsiveness of two arms of the baroreflex (HR vs. MSNA) to successfully maintain BP during tilt in healthy humans based on pre‐tilt differences in cardiovascular and fluid volume status.

Support or Funding Information

Funded by USAMRMC; author views not official US Army or DOD policy.
Molecular phenotypes of gills from resident marine versus landlocked freshwater three‐spined sticklebacks (Gasterosteus aculeatus)
Authors: Li Johnathon , Paguio Darlene May , Kültz Dietmar
Published: June 2021

To analyze the influence of marine versus freshwater (FW) habitats on branchial proteomes of three‐spined sticklebacks, we compared a resident marine (Bodega Harbor, CA) with a landlocked FW (Lake Solano, CA) population. The marine population represents a classical fully plated morphotype whereas the FW population represents a typical low‐plated morphotype as assessed after staining fish with Alizarin Red and analysis of morphometric parameters that define stickleback morphotypes. Unbiased label‐free proteomics was used to identify and quantify over 1700 branchial proteins. Thirty four proteins identified to differ significantly (p<0.05) and by more than 2‐fold in abundance were targeted for data‐independent acquisition and quantitative tandem mass spectrometry (MS2) reaction monitoring with Skyline. Proteins confirmed to be significantly different in abundance were then further analyzed for gene ontology enrichment to assess population‐specific gill functions. Ion transport, oxidative metabolism and redox regulation were significantly enriched in gills of marine sticklebacks while cell/epithelial morphogenesis and proteolysis were significantly enriched in FW sticklebacks. We conclude that these branchial functions and the proteins that mechanistically support them are strong targets of selection when marine sticklebacks invade FW habitats.

Support or Funding Information

National Science Foundation IOS‐1355098.