bluuebunny/crossref_metadata_2025_split huggingface dataset:
Skeletal muscle mitochondrial respiration in a model of age-related osteoarthritis is impaired after dietary rapamycin
Authors: Elliehausen Christian J. , Minton Dennis M. , Nichol Alexander D. , Konopka Adam R. 
Published: June 2021

AbstractA decline in skeletal muscle mitochondrial function is associated with the loss of skeletal muscle size and function during knee osteoarthritis (OA). We have recently reported that the 12-weeks of dietary rapamycin (Rap, 14ppm), with or without metformin (Met, 1000ppm), increased plasma glucose and OA severity in male Dunkin Hartley (DH) guinea pigs, a model of naturally occurring, age-related OA. The purpose of the current study was to determine if increased OA severity after dietary Rap and Rap+Met was accompanied by impaired skeletal muscle mitochondrial function. Mitochondrial respiration and hydrogen peroxide (H2O2) emissions were evaluated in permeabilized muscle fibers via high-resolution respirometry and fluorometry using either a saturating bolus or titration of ADP. Rap and Rap+Met decreased complex I (CI)-linked respiration and increased ADP sensitivity, consistent with previous findings in patients with end-stage OA. Rap also tended to decrease mitochondrial H2O2 emissions, however, this was no longer apparent after normalizing to respiration. The decrease in CI-linked respiration was accompanied with lower CI protein abundance. This is the first inquiry into how lifespan extending treatments Rap and Rap+Met can influence skeletal muscle mitochondria in a model of age-related OA. Collectively, our data suggest that Rap with or without Met inhibits CI-linked capacity and increases ADP sensitivity in DH guinea pigs that have greater OA severity.
p53 mutations exhibit sex specific gain-of-function activity in gliomagenesis
Authors: Rockwell Nathan , Yang Wei , Warrington Nicole , Griffith Malachi , Griffith Obi , Gurnett Christina , Cohen Barak , Baldridge Dustin , Rubin Joshua 
Published: June 2021

AbstractThe tumor suppressor TP53 is the most frequently mutated gene in cancer. Most TP53 mutations are missense mutations in the DNA-binding domain, which in addition to loss of canonical p53 activity, frequently confer gain-of-function (GOF) aberrant transcriptional activity through mutant p53 localization to non-canonical genes. GOF phenotypes differ by mutation and cell identity and are reported to include increased proliferation, migration, metabolic reprogramming, and therapy resistance. We found that several recurring p53 mutations exhibit a sex-bias in patients with glioblastoma (GBM). In vitro and in vivo analysis of three mutations, p53R172H, p53Y202C, and p53Y217C revealed sex differences in each mutation’s ability to transform primary mouse astrocytes. p53R172H exhibited a far greater ability to transform female astrocytes than males, p53Y202C transformed both male and female astrocytes with a small male bias, and p53Y217C only exhibited GOF transformation effects in male astrocytes. These phenotypic differences reflect an interaction between sex and GOF mutation to drive unique gene expression patterns in cancer pathways. We found that mutant p53 exhibits sex and mutation specific aberrant genomic localization to the transcriptional start sites of upregulated genes, whose promoter regions were enriched for different sets of transcription factor DNA-binding motifs. Together, our data establish a novel paradigm for sex specific mutant p53 GOF activity in GBM with implications for all cancer.
The YcnI protein from Bacillus subtilis contains a copper-binding domain
Authors: Damle Madhura S. , Peters Stephen C. , Szalai Veronika A. , Fisher Oriana S. 
Published: June 2021

AbstractBacteria require a precise balance of copper ions to ensure that essential cuproproteins are fully metalated while also avoiding copper-induced toxicity. The Gram positive bacterium Bacillus subtilis maintains appropriate copper homeostasis in part through its ycn operon. The ycn operon comprises genes encoding three proteins: the putative copper importer YcnJ, the copper-dependent transcriptional repressor YcnK, and the uncharacterized DUF1775 domain-containing YcnI. DUF1775 domains are found across bacterial phylogeny and bioinformatics analyses indicate that they frequently neighbor domains implicated in copper homeostasis and transport. Here, we investigated whether YcnI can interact with copper and, using electron paramagnetic resonance (EPR) and inductively-coupled plasma-mass spectrometry (ICP-MS) find that it can bind a single Cu(II) ion. We determine the structure of both the apo and copper-bound forms of the protein by X-ray crystallography, uncovering a copper binding site featuring a unique mono-histidine brace ligand set that is highly conserved among DUF1775 domains. These data suggest a possible role for YcnI as a copper chaperone and that DUF1775 domains in other bacterial species may also function in copper homeostasis.
In situ treatment of H. pylori infection in mice stomach with bioengineered probiotic bacteria releasing guided Antimicrobial peptides
Authors: Choudhury Ankan , Ortiz Patrick , Kearney Christopher M. 
Published: June 2021

AbstractObjectivesTargeted therapies seek to selectively eliminate a pathogen without disrupting the resident microbial community. This is even more important when a pathogen like H. pylori resides in stomach, a sensitive microbial ecosystem. Using a probiotic like Lactococcus lactis and bioengineering it to release a guided Antimicrobial Peptide (AMP) targeted towards the pathogen offers a pathway to specifically knock-out the deleterious species and not disturbing the stomach microbiome.ResultsThree AMPs, Alyteserin, CRAMP and Laterosporulin, were genetically fused to a guiding peptide MM1, which selectively binds to Vacuolating Toxin A (VacA) of H. pylori and cloned into an excretory vector pTKR inside L. lactis. The probiotics were then fed to mice infected with H. pylori, both as a therapeutic and prophylactic measure, and the samples were collected using a novel gavage method and analyzed using qPCR and Illumina sequencing of the extracted stomach samples over a 10-day period. Microbiome analysis with Next-Gen sequencing also revealed a dysbiosis created by H. pylori, determined by creating a Correlation network model with the relative abundances of taxa across the samples, and this dysbiosis was palliated by the bioengineered probiotics which preserved and boosted key microbiome species and reducing the load of deleterious ones. The bioengineered probiotic also significantly improved the OTU diversity compared to antibiotics and L. lactis cloned with empty vector, with gAMP-L. lactis faring the best.ConclusionsProbiotics bioengineered to excrete guided AMPs can be a novel and useful approach for combating pathogens without endangering the natural microbial flora. Given the wealth of AMPs and guiding ligands, both natural and synthetic, this approach can be adapted to develop a diverse array of chimeric guided AMPs and can be cloned into probiotics to create a safe and effective alternative to conventional chemical antibiotics.
Phytochemical Nrf2 activator attenuates skeletal muscle mitochondrial dysfunction and impaired proteostasis in a preclinical model of musculoskeletal aging
Authors: Musci Robert V. , Andrie Kendra M. , Walsh Maureen A. , Valenti Zackary J. , Afzali Maryam F. , Johnson Taylor , Kail Thomas E. , Martinez Richard , Nguyen Tessa , Sanford Joseph L. , Murrell Meredith D. , McCord Joe M. , Hybertson Brooks M. , Miller Benjamin F. , Zhang Qian , Javors Martin A. , Santangelo Kelly S. , Hamilton Karyn L. 
Published: June 2021

AbstractMusculoskeletal dysfunction is an age-related syndrome associated with impaired mitochondrial function and proteostasis. However, few interventions have tested targeting two drivers of musculoskeletal decline. Nuclear factor erythroid 2-related factor 2 (Nrf2) is a transcription factor that stimulates transcription of cytoprotective genes and improves mitochondrial function. We hypothesized daily treatment with a Nrf2 activator in Hartley guinea pigs, a model of age-related musculoskeletal dysfunction, attenuates the progression of skeletal muscle mitochondrial dysfunction and impaired proteostasis, preserving musculoskeletal function. We treated 2-month- and 5-month-old male and female Hartley guinea pigs for 3 and 10 months, respectively, with the phytochemical Nrf2 activator PB125 (Nrf2a). Longitudinal assessments of voluntary mobility were measured using Any-Maze™ open-field enclosure monitoring. Cumulative skeletal muscle protein synthesis rates were measured using deuterium oxide over the final 30 days of treatment. Mitochondrial oxygen consumption in permeabilized soleus muscles was measured using ex vivo high resolution respirometry. In both sexes, Nrf2a 1) increased electron transfer system capacity; 2) attenuated the disease/age-related decline in coupled and uncoupled mitochondrial respiration; and 3) attenuated declines in protein synthesis in the myofibrillar, mitochondrial, and cytosolic subfractions of the soleus. These improvements were not associated with statistically significant prolonged maintenance of voluntary mobility in guinea pigs. Collectively, these results demonstrate that treatment with an oral Nrf2 activator contributes to maintenance of skeletal muscle mitochondrial function and proteostasis in a pre-clinical model of musculoskeletal decline. Further investigation is necessary to determine if these improvements are also accompanied by slowed progression of other aspects of musculoskeletal decline.
Cell-matrix adhesion contributes to permeability control in human colon organoids
Authors: Varani James , McClintock Shannon D. , Aslam Muhammad N. 
Published: June 2021

ABSTRACTBackground and aimsCell-cell adhesion structures (desmosomes and, especially, tight junctions) are known to play important roles in control of transepithelial permeability in the colon. The involvement of cell-matrix interactions in permeability control is less clear. The goals of the present study were to: i) determine if disruption of colon epithelial cell interactions with the extracellular matrix alters permeability control and ii) determine if increasing the elaboration of protein components of cell-matrix adhesion complexes improves permeability control and mitigates the effects of cell-matrix disruption.MethodsHuman colon organoids were interrogated for transepithelial electrical resistance (TEER) under control conditions (0.25 mM calcium) and in the presence of Aquamin®, a multi-mineral product, at a level providing 1.5 mM calcium. The effects of Aquamin® on cell-matrix adhesion protein expression were determined in a proteomic screen and by Western blotting. In parallel, TEER was assessed in the presence of a function-blocking antibody directed at an epitope in the C-terminal region of laminin α3 chain.ResultsTreatment of colon organoids with Aquamin® increased the expression of multiple basement membrane and hemidesmosomal proteins as well as keratin 8 and 18. TEER values were higher in the presence of Aquamin® than they were under control conditions. Anti-laminin antibody reduced TEER values under all conditions but was most effective in the absence of Aquamin®, where laminin expression was low and TEER values were lower to begin with.ConclusionsThese findings provide evidence that cell-matrix interactions contribute to permeability control in the colon. They suggest that the elaboration of proteins important to cell-matrix interactions can be increased in human colon organoids by exposure to a multi-mineral natural product. Increasing the elaboration of such proteins may help to mitigate the consequences of disrupting cell-matrix interactions on permeability control.
Developmental Regulation of Homeostatic Plasticity in Mouse Primary Visual Cortex
Authors: Wen Wei , Turrigiano Gina G. 
Published: June 2021

AbstractHomeostatic plasticity maintains network stability by adjusting excitation, inhibition, or the intrinsic excitability of neurons, but the developmental regulation and coordination of these distinct forms of homeostatic plasticity remains poorly understood. A major contributor to this information gap is the lack of a uniform paradigm for chronically manipulating activity at different developmental stages. To overcome this limitation, we utilized Designer Receptors Exclusively Activated by Designer Drugs (DREADDs) to directly suppress neuronal activity in layer (L) 2/3 of mouse primary visual cortex (V1) at two important developmental timepoints: the classic visual system critical period (CP, P24-29), and adulthood (P45-55). We show that 24 hours of DREADD-mediated activity suppression simultaneously induces excitatory synaptic scaling up and intrinsic homeostatic plasticity in L2/3 pyramidal neurons during the CP, consistent with previous observations using prolonged visual deprivation. Importantly, manipulations known to block these forms of homeostatic plasticity when induced pharmacologically or via visual deprivation also prevented DREADD-induced homeostatic plasticity. We next used the same paradigm to suppress activity in adult animals. Surprisingly, while excitatory synaptic scaling persisted into adulthood, intrinsic homeostatic plasticity was completely absent. Finally, we found that homeostatic changes in quantal inhibitory input onto L2/3 pyramidal neurons were absent during the CP but present in adults. Thus, the same population of neurons can express distinct sets of homeostatic plasticity mechanisms at different development stages. Our findings suggest that homeostatic forms of plasticity can be recruited in a modular manner according to the evolving needs of a developing neural circuit.Significance statementDeveloping brain circuits are subject to dramatic changes in inputs that could destabilize activity if left uncompensated. This compensation is achieved through a set of homeostatic plasticity mechanisms that provide slow, negative feedback adjustments to excitability. Given that circuits are subject to very different destabilizing forces during distinct developmental stages, the forms of homeostatic plasticity present in the network must be tuned to these evolving needs. Here we developed a method to induce comparable homeostatic compensation during distinct developmental windows, and found that neurons in the juvenile and mature brain engage strikingly different forms of homeostatic plasticity. Thus, homeostatic mechanisms can be recruited in a modular manner according to the developmental needs of the circuit.
A panel of KSHV mutants in the polycistronic kaposin locus for precise analysis of individual protein products
Authors: Kleer Mariel , MacNeil Grant , Pringle Eric S. , Corcoran Jennifer A. 
Published: June 2021

AbstractKaposi’s sarcoma-associated herpesvirus (KSHV) is the cause of several human cancers including the endothelial cell (EC) malignancy, Kaposi’s sarcoma. Unique KSHV genes absent from other human herpesvirus genomes, the “K-genes”, are important for KSHV replication and pathogenesis. Among these, the kaposin transcript is highly expressed in all phases of infection, but its complex polycistronic nature has hindered functional analysis to date. At least three proteins are produced from the kaposin transcript: Kaposin A (KapA), B (KapB), and C (KapC). To determine the relative contributions of kaposin proteins during KSHV infection, we created a collection of mutant viruses unable to produce kaposin proteins individually or in combination. Kaposin-deficient latent iSLK cell lines displayed reduced viral genome copy number and often exhibited small LANA nuclear bodies; despite this, all were capable of progeny virion production. Primary infection with ΔKapB virus revealed decreased LANA expression and viral genome copy number, yet providing KapB protein in trans failed to complement these defects, suggesting a requirement for the kaposin locus in cis. Our previous work showed that KapB was sufficient to recapitulate the elevated proinflammatory cytokine transcripts associated with KS via the disassembly of RNA granules called processing bodies (PBs). We now show that KapB is necessary for PB disassembly during latent KSHV infection. These findings demonstrate that our panel of kaposin-deficient viruses enables precise analysis of the respective contributions of individual kaposin proteins to KSHV replication. Moreover, our mutagenesis approach serves as a guide for the functional analysis of other complex multicistronic viral loci.ImportanceKaposi’s sarcoma-associated herpesvirus (KSHV) expresses high levels of the kaposin transcript during both latent and lytic phases of replication. Due to its repetitive, GC-rich nature and polycistronic coding capacity, until now no reagents existed to permit a methodical analysis of the role of individual kaposin proteins in KSHV replication. We report the creation of a panel of recombinant viruses and matched producer cell lines that delete kaposin proteins individually or in combination. We demonstrate the utility of this panel by confirming the requirement of one kaposin translation product to a key KSHV latency phenotype. This study describes a new panel of molecular tools for the KSHV field to enable precise analysis of the roles of individual kaposin proteins during KSHV infection.
A quantitative gibberellin signalling biosensor reveals a role for gibberellins in internode specification at the shoot apical meristem
Authors: Shi Bihai , Felipo-Benavent Amelia , Cerutti Guillaume , Galvan-Ampudia Carlos , Jilli Lucas , Brunoud Geraldine , Mutterer Jérome , Vallet Elody , Sakvarelidze-Achard Lali , Davière Jean-Michel , Navarro-Galiano Alejandro , Walia Ankit , Lazary Shani , Legrand Jonathan , Weinstain Roy , Jones Alexander M. , Prat Salomé , Achard Patrick , Vernoux Teva 
Published: June 2021

AbstractGrowth at the shoot apical meristem (SAM) is essential for shoot architecture construction. The phytohormones gibberellins (GA) play a pivotal role in coordinating plant growth, but their role in the SAM remains mostly unknown. Here, we developed a ratiometric GA signalling biosensor by engineering one of the DELLA proteins, to suppress its master regulatory function in GA transcriptional responses while preserving its degradation upon GA sensing. We demonstrate that this novel degradation-based biosensor accurately reports on cellular changes in GA levels and perception during development. We used this biosensor to map GA signalling activity in the SAM. We show that high GA signalling is found primarily in cells located between organ primordia that are the precursors of internodes. By gain- and loss-of-function approaches, we further demonstrate that GAs regulate cell division plane orientation to establish the typical cellular organisation of internodes, thus contributing to internode specification in the SAM.
Extrusion and solid-state fermentation with Aspergillus oryzae on the phenolic compounds and radical scavenging activity of pecan nut (Carya illinoinensis) shell
Authors: Villasante Juliana , Espinosa-Ramírez Johanan , Pérez-Carrillo Esther , Heredia-Olea Erick , Almajano MariaPilar 
Published: June 2021

PurposeSolid-state fermentation (SSF) has been highlighted as an alternative to obtain valuable compounds using agro-industrial wastes as a substrate. The present study evaluated the impact of extrusion combined with SSF on the production of phenolic compounds and their antioxidant activity using pecan nut shell (PWS) as a substrate.Design/methodology/approachPWS and extruded pecan nut shell (PWSE) were fermented for 120 h at 30°C using Aspergillus oryzae (A. oryzae). Samples were withdrawn from incubator at 6 h, 12 h and then every 12 h until 120 h fermentation. PWS and PWSE samples were extracted. The total phenolic content (TPC) and radical scavenging activity (RSA) extracts were characterized from the resulting extracts.FindingsThe use of PWSE yielded higher A. oryzae biomass and at a higher rate after 120 h of fermentation (PWS 75.74% vs PWSE 87.50%). In general, the TPC and the RSA increased with fermentation time. However, the PWSE yielded significantly higher (p < 0.05) TPC and RSA values after SSF in comparison to the nonextruded PWS. Condensed tannins showed different trends depending on the fermented substrate. Overall, results showed that the extrusion pretreatment joint with the SSF represents a good alternative to raise the phenolic content and antiradical activity of lignocellulosic materials such as PWSs.Originality/valueThis study offers valuable information that may be used by the pecan walnut industry to valorize the shell coproduct as a substrate to produce functional ingredients or fungal enzymes.
Assessment of the effects of supervisor behaviour, safety motivation and perceived job insecurity on underground miner’s safety citizenship behaviour
Authors: Quansah Prince Ewudzie , Zhu Yongyue , Obeng Anthony Frank 
Published: June 2021

PurposeThis paper aims to investigate the effect of mining supervisor behaviour, safety motivation and perceived job insecurity on Ghanaian underground miner’s safety citizenship behaviour.Design/methodology/approachThe authors proposed a conceptual framework that tested supervisor behaviour as an independent variable, safety motivation as a mediator variable, perceived job insecurity as a moderator variable and safety citizenship behaviour as a dependent variable. The authors tested the hypothesized relationships using 351 valid responses collected through a structured questionnaire using hierarchical regression analysis.FindingsResults revealed that both components of supervisor behaviour significantly influenced safety motivation and safety citizenship behaviour. Furthermore, safety motivation could mediate the relationships between both components of supervisor behaviour and safety citizenship behaviour. Also, perceived job insecurity failed to moderate the relationship between safety motivation and safety citizenship behaviour.Originality/valueThis current study is vital for managerial practices. The complex conceptual framework also contributes to offering different ways of understanding how supervisors’ behaviours can catalyze improvement or worsen safety outcomes.