bluuebunny/crossref_metadata_2025 huggingface dataset:
Serum albumin maintains Wnt water-solubility and activity
Authors: Yeo Joo Hye , Kwon Soon Sung , Chae Jiyeon , Kusen Ines , Han Jaeeun , Lim Ju Yeon , Cheong Jae-Ho , Kim Taeil , Jung Yang Ouk , Kim Chul Hoon , Lee Jinu
Published: January 2023

Wnt proteins regulate adult tissue homeostasis and repair by driving stem cell self-renewal and differentiation. High-performance Wnt preparations have enormous therapeutic potential, especially alongside various stem cell technologies. Currently, most of these Wnt preparations contain FBS or the detergent CHAPS to maintain Wnt solubility and activity. Recently, afamin was identified as a serum factor that solubilizes Wnt3a in conditioned media (CM), obviating the requirement for animal sera. Here, we report serum albumin (SA) is required for afamin-mediated solubilization of Wnt3a in CM. Moreover, SA-mediated solubilization of purified Wnt3a in tubes does not require afamin. This means conventional CHAPS-Wnt3a preparations can be modified into SA-purified Wnt3a (SA-pWnt3a) preparations by exchanging CHAPS for SA through dialysis. SA-pWnt3a preparations effectively promote the growth of human stem cell organoids. These data suggest SA as a physiological factor for maintaining Wnt3a activity in therapeutic applications.
Sensory constraints on volitional modulation of the motor cortex
Authors: Fisac Carmen F. , Chase Steven M.
Published: January 2023

Voluntary movement is driven by the primary motor cortex (M1), and individuals can learn to modulate even single neurons at will. Yet M1 also receives pronounced sensory inputs and contributes to sensory-driven motor responses. To what extent do these non-volitional signals restrict voluntary modulation of M1? Using a task in which the firing rate of a single neuron directly determines the position of a computer cursor along a visual axis, we assessed the ability of monkeys to modulate individual neurons under different sensory contexts. We found that sensory context persistently affected volitional control of single neurons in M1. For instance, visually rotating the biofeedback axis could render the same neural task effortless or problematic. Notably, extended training within or across days did not resolve this disparity. Our findings suggest that sensory context can limit the degree to which M1 activity is under volitional control.
Finding the LMA needle in the wheat proteome haystack
Authors: Vincent Delphine , Bui AnhDuyen , Ezernieks Vilnis , Shahinfar Saleh , Luke Timothy , Ram Doris , Rigas Nicholas , Panozzo Joe , Rochfort Simone , Daetwyler Hans , Hayden Matthew
Published: January 2023

Late maturity alpha-amylase (LMA) is a wheat genetic defect causing the synthesis of high isoelectric point (pI) alpha-amylase in the aleurone as a result of a temperature shock during mid-grain development or prolonged cold throughout grain development leading to an unacceptable low falling numbers (FN) at harvest or during storage. High pI alpha-amylase is normally not synthesized until after maturity in seeds when they may sprout in response to rain or germinate following sowing the next season’s crop. Whilst the physiology is well understood, the biochemical mechanisms involved in grain LMA response remain unclear. We have employed high-throughput proteomics to analyse thousands of wheat flours displaying a range of LMA values. We have applied an array of statistical analyses to select LMA-responsive biomarkers and we have mined them using a suite of tools applicable to wheat proteins. To our knowledge, this is not only the first proteomics study tackling the wheat LMA issue, but also the largest plant-based proteomics study published to date. Logistics, technicalities, requirements, and bottlenecks of such an ambitious large-scale high-throughput proteomics experiment along with the challenges associated with big data analyses are discussed. We observed that stored LMA-affected grains activated their primary metabolisms such as glycolysis and gluconeogenesis, TCA cycle, along with DNA- and RNA binding mechanisms, as well as protein translation. This logically transitioned to protein folding activities driven by chaperones and protein disulfide isomerase, as wellas protein assembly via dimerisation and complexing. The secondary metabolism was also mobilised with the up-regulation of phytohormones, chemical and defense responses. LMA further invoked cellular structures among which ribosomes, microtubules, and chromatin. Finally, and unsurprisingly, LMA expression greatly impacted grain starch and other carbohydrates with the up-regulation of alpha-gliadins and starch metabolism, whereas LMW glutenin, stachyose, sucrose, UDP-galactose and UDP-glucose were down-regulated. This work demonstrates that proteomics deserves to be part of the wheat LMA molecular toolkit and should be adopted by LMA scientists and breeders in the future.
“Self-inhibition of HER2 at fever temperatures may prevent dimerization with HER3”
Authors: Singh Puneet K. , Stan Razvan C.
Published: January 2023

Background

HER2 receptor is overexpressed in different aggressive and recurrent tumors, and the modulation of its conformational changes has been achieved using immunotherapy or chemotherapy.

Objective

To assess the role of fever temperatures on the dynamics of HER2 in the absence of a binding partner.

Methods

Molecular dynamics simulations of apo-HER2 were performed at 37□-40□, in order to gauge its intramolecular dynamics.

Results

HER2 assumes an inactive and “bent” conformation at 40□, while it maintains its extended, active conformation that can dimerize with other HER partners, in the 37□-39□ range.

Conclusion

These novel results indicate the role of fever temperatures on modulating conformational changes in an essential tumor target. Cancer treatment can leverage the use of thermal therapy at particular fever points, in order to complement existing radio or chemotherapy options.
A New Approach for Active Coronavirus Infection Identification by Targeting the Negative RNA Strand- A Replacement for the Current Positive RNA-based qPCR Detection Method
Authors: Davis Darnell , Ullah Hemayet
Published: January 2023

This manuscript describes the development of an alternative method to detect active coronavirus infection, in light of the current COVID-19 pandemic caused by the SARS-CoV-2 virus. The pandemic, which was first identified in Wuhan, China in December 2019, has had a significant impact on global health as well as on the economy and daily life in the world. The current positive RNA-based detection systems are unable to discriminate between replicating and non-replicating viruses, complicating decisions related to quarantine and therapeutic interventions. The proposed method targets the negative strand of the virus and has the potential to effectively distinguish between active and inactive infections, which could provide a more accurate means of determining the spread of the virus and guide more effective public health measures during the current pandemic.
Global analysis of aging-related protein structural changes uncovers enzyme polymerization-based control of longevity
Authors: Paukštytė Jurgita , López Cabezas Rosa María , Feng Yuehan , Tong Kai , Schnyder Daniela , Elomaa Ellinoora , Gregorova Pavlina , Doudin Matteo , Särkkä Meeri , Sarameri Jesse , Lippi Alice , Vihinen Helena , Juutila Juhana , Nieminen Anni , Törönen Petri , Holm Liisa , Jokitalo Eija , Krisko Anita , Huiskonen Juha , Sarin L. Peter , Hietakangas Ville , Picotti Paola , Barral Yves , Saarikangas Juha
Published: January 2023

Aging is associated with progressive phenotypic changes over time. Virtually all cellular phenotypes are produced by proteins and structural alterations in proteins can lead to age-related diseases. Nonetheless, comprehensive knowledge of proteins undergoing structural-functional changes during cellular aging and their contribution to age-related phenotypes is lacking. Here, we conducted proteome-wide analysis of early age-related protein structural changes in budding yeast using limited proteolysis-mass spectrometry. The results, compiled in online ProtAge-catalog, unravelled age-related functional changes in regulators of translation, protein folding and amino acid metabolism. Mechanistically, we found that folded glutamate synthase Glt1 polymerizes into supramolecular self-assemblies during aging causing breakdown of cellular amino acid homeostasis. Inhibiting Glt1 polymerization by mutating the polymerization interface restored amino acid levels in aged cells, attenuated mitochondrial dysfunction and led to life span extension. Altogether, this comprehensive map of protein structural changes enables identifying novel mechanisms of age-related phenotypes and offers opportunities for their reversal.
A planar-polarized MYO6-DOCK7-RAC1 axis promotes tissue fluidification in mammary epithelia
Authors: Menin Luca , Weber Janine , Villa Stefano , Martini Emanuele , Maspero Elena , Cancila Valeria , Maiuri Paolo , Palamidessi Andrea , Frittoli Emanuela , Bianchi Fabrizio , Tripodo Claudio , Walters Kylie J. , Giavazzi Fabio , Scita Giorgio , Polo Simona
Published: January 2023

Tissue fluidification and collective motility are pivotal in regulating embryonic morphogenesis, wound healing and tumor metastasis. These processes frequently require that each cell constituent of a tissue coordinates its migration activity and directed motion through the oriented extension of lamellipodia cell protrusions, promoted by RAC1 activity. While the upstream RAC1 regulators in individual migratory cells or leader cells during invasion or wound healing are well characterized, how RAC1 is controlled in follower cells remains unknown. Here, we identify a novel MYO6-DOCK7 axis that is critical for spatially restriction of RAC1 activity in a planar polarized fashion in model tissue monolayers. The MYO6-DOCK7 axis specifically controls the extension of cryptic lamellipodia required to drive tissue fluidification and cooperative mode motion in otherwise solid and static carcinoma cell collectives.

Highlights

Collective motion of jammed epithelia requires myosin VI activity

The MYO6-DOCK7 axis is critical to restrict the activity of RAC1 in a planar polarized fashion

MYO6-DOCK7-RAC1 activation ensures long-range coordination of movements by promoting orientation and persistence of cryptic lamellipodia

Myosin VI overexpression is exploited by infiltrating breast cancer cells
Assessing HLA imputation accuracy in a West African population
Authors: Nanjala Ruth , Mbiyavanga Mamana , Hashim Suhaila , de Villiers Santie , Mulder Nicola
Published: January 2023

The Human Leukocyte Antigen (HLA) region plays an important role in autoimmune and infectious diseases. HLA is a highly polymorphic region and thus difficult to impute. We therefore sought to evaluate HLA imputation accuracy, specifically in a West African population, since they are understudied and are known to harbor high genetic diversity. The study sets were selected from Gambian individuals within the Gambian Genome Variation Project (GGVP) Whole Genome Sequence datasets. Two different arrays, Illumina Omni 2.5 and Human Hereditary and Health in Africa (H3Africa), were assessed for the appropriateness of their markers, and these were used to test several imputation panels and tools. The reference panels were chosen from the 1000 Genomes dataset (1kg-All), 1000 Genomes African dataset (1kg-Afr), 1000 Genomes Gambian dataset (1kg-Gwd), H3Africa dataset and the HLA Multi-ethnic dataset. HLA-A, HLA-B and HLA-C alleles were imputed using HIBAG, SNP2HLA, CookHLA and Minimac4, and concordance rate was used as an assessment metric. Overall, the best performing tool was found to be HIBAG, with a concordance rate of 0.84, while the best performing reference panel was the H3Africa panel with a concordance rate of 0.62. Minimac4 (0.75) was shown to increase HLA-B allele imputation accuracy compared to HIBAG (0.71), SNP2HLA (0.51) and CookHLA (0.17). The H3Africa and Illumina Omni 2.5 array performances were comparable, showing that genotyping arrays have less influence on HLA imputation in West African populations. The findings show that using a larger population-specific reference panel and the HIBAG tool improves the accuracy of HLA imputation in West African populations.

Author Summary

For studies that associate a particular HLA type to a phenotypic trait for instance HIV susceptibility or control, genotype imputation remains the main method for acquiring a larger sample size. Genotype imputation, process of inferring unobserved genotypes, is a statistical technique and thus deals with probabilities. Also, the HLA region is highly variable and therefore difficult to impute. In view of this, it is important to assess HLA imputation accuracy especially in African populations. This is because the African genome has high diversity, and such studies have hardly been conducted in African populations. This work highlights that using HIBAG imputation tool and a larger population-specific reference panel increases HLA imputation accuracy in an African population.
PNAG exopolysaccharide eradication gives neutrophils access toStaphylococcus aureusbiofilm infections
Authors: Kratofil Rachel M. , Randall Trevor E. , Hommes Josefien W. , Sejuty Rehnuma , Chisholm Jessica , Raju Deepa , Vargas Mario , Howell P. Lynne , Pier Gerald B. , Morck Douglas W. , Harrison Joe J. , Kubes Paul
Published: January 2023

Staphylococcus aureus(S. aureus) can form biofilms on biotic or abiotic surfaces making biofilm infections a relevant clinical problem. Biofilms can evade immunity and resist antimicrobial treatment, and as such an understanding of biofilm infectionin vivois necessary to inform new therapeutics. Using a mouse model ofS. aureusforeign-body skin infection and intravital microscopy, we imaged the interactions between neutrophils andS. aureusbiofilm. We observed that neutrophils were separated from bacteria by a biofilm matrix composed of the polysaccharide intercellular adhesin (PIA), an exopolysaccharide chemically designated as poly-N-acetylglucosamine (PNAG) that is produced by enzymatic machinery encoded by theicaADBCoperon. Infection withicaADBC-deficient S. aureusstrains led to increased neutrophil infiltration and access to bacteria and resulted in full clearance of infection by 7 days. Moreover, enzymatic treatment with PgaB, which hydrolyzes partially deacetylated PNAG, was shown to disaggregate the biofilm giving neutrophils access into the infection site to improve clearance. Taken together, our results show that PNAG sheltersS. aureusbiofilms from innate host defense, and that targeting the biofilm matrix with glycoside hydrolases is a promising therapeutic avenue to treatS. aureusbiofilm infections.

Author Summary

Staphylococcus aureusis a major cause of biofilm-associated infections, which pose a major threat to human health. A biofilm is difficult to treat since bacteria are protected from antimicrobials within an extracellular matrix. This study is the first to show that the PgaB enzyme, a glycoside hydrolase, can disrupt theS. aureusbiofilm matrix in vivo. Disrupting the biofilm matrix with PgaB gives neutrophils access to bacteria for elimination.
YTHDC2 serves a distinct late role in spermatocytes during germ cell differentiation
Authors: Bailey Alexis S. , Fuller Margaret T.
Published: January 2023

Post-transcriptional regulation of gene expression by RNA-binding proteins can enhance the speed and robustness of cell state transitions by controlling RNA stability, localization, or if, when or where mRNAs are translated. The RNA helicase YTHDC2 is required to shut down components of the mitotic program to facilitate a proper switch from mitosis to meiosis in mouse germ cells. Here we show that YTHDC2 has a second essential role in promoting meiotic progression in late spermatocytes. Inducing conditional knockout ofYthdc2during the first wave of spermatogenesis, after initiation of meiotic prophase, allowedYthdc2-deficient germ cells to advance to the pachytene stage and properly express many meiotic markers. However, theYthdc2-deficient spermatocytes mis-expressed a number of genes, some up-regulated and some down-regulated, failed to transition to the diplotene stage, then quickly died. Co-immunoprecipitation experiments revealed that YTHDC2 interacts with several RNA-binding proteins in early or late spermatocytes, with many of the interacting proteins, including MEIOC, localizing to granules, similar to YTHDC2. Our findings suggest that YTHDC2 collaborates with other RNA granule components to facilitate proper progression of germ cells through multiple steps of meiosis via mechanisms influencing post-transcriptional regulation of RNAs.

SIGNIFICANCE STATEMENT

An effective, robust switch from mitosis to meiosis is essential for the production of gametes in sexually reproducing organisms. The RNA helicase YTHDC2 is required for germ cells to shut down aspects of the mitotic program as they initiate meiotic prophase in the mouse male germline. Here we utilize a timed conditional knockout strategy to show that, in addition to its conserved function in the mitosis-to-meiosis transition, YTHDC2 has a second critical role in promoting the pachytene-to-diplotene transition late in male meiotic prophase. YTHDC2 interacts with several proteins that are also present in RNA granules, including MEIOC, suggesting that YTHDC2 collaborates with RNA granule components to regulate RNAs as germ cells progress from one cell state to the next.
MHC class II antigen presentation by intestinal epithelial cells fine-tunes bacteria-reactive CD4 T cell responses
Authors: Heuberger C. E. , Janney A. , Ilott N. , Bertocchi A. , Pott S. , Gu Y. , Pohin M. , Friedrich M. , Mann E. H. , Pearson C. , Powrie F. M. , Pott J. , Thornton E. , Maloy K. J.
Published: January 2023

Although intestinal epithelial cells (IECs) can express major histocompatibility complex class II (MHC II), especially during intestinal inflammation, it remains unclear if antigen presentation by IECs favours pro- or anti-inflammatory CD4+T cell responses. Using selective gene ablation of MHC II in IECs and IEC organoid cultures, we assessed the impact of MHC II expression by IECs on CD4+T cell responses and disease outcomes in response to enteric bacterial pathogens. We found that intestinal bacterial infections elicit inflammatory cues that greatly increase expression of MHC II processing and presentation molecules in colonic IECs. Whilst IEC MHC II expression had little impact on disease severity followingCitrobacter rodentiumorHelicobacter hepaticusinfection, using a colonic IEC organoid-CD4+T cell co-culture system, we demonstrate that IECs can activate antigen-specific CD4+T cells in an MHC II-dependent manner, modulating both regulatory and effector Th cell subsets. Furthermore, we assessed adoptively transferredH. hepaticus-specific CD4+T cells during intestinal inflammationin vivoand report that IEC MHC II expression dampens pro-inflammatory effector Th cells. Our findings indicate that IECs can function as non-conventional antigen presenting cells and that IEC MHC II expression fine-tunes local effector CD4+T cell responses during intestinal inflammation.
A network pharmacology approach to assess the comparative pharmacodynamics of pharmaceutical excipient trehalose in human, mouse and rat
Authors: Friend Jack , Kumar Arun HS
Published: January 2023

Background

Trehalose is used as a pharmaceutical excipient due to its several desirable pharmacokinetic and historically evident safety features. However, information on the pharmacodynamic properties of trehalose is lacking. Hence this study evaluated the comparative pharmacodynamic properties of trehalose using a network pharmacology approach.

Materials and methods

The specific targets of trehalose in human, mouse and rat were identified from the SwissTargetPrediction database, categorised and compared. The expression profile and subcellular localisation of the targets of trehalose in human was identified and correlated with the affinity of trehalose to these targets to assess its impact on the pharmacodynamic properties of trehalose. The affinity of trehalose to its metabolising enzyme in human, mouse, and rat was assessed by molecular docking and compared.

Results

A significant difference in the target categories and target types of trehalose was observed in human, mouse, and rat. The affinity of trehalose to human (66.03 ± 5.1 μM), rat (102.53 ± 11.3 μM) and mouse (42.07 ± 5.3 μM) trehalase was significantly different. Family A G protein coupled receptors were identified as the major target category of trehalose and cyclin dependent kinase 1 was observed as the high affinity target of trehalose in human and mouse. The correlation of target expression and affinity indicated minimal pharmacodynamic influence under physiological conditions.

Conclusion

This study reports the selective targets of trehalose relevant to drug discovery and development protocols and highlights the limitations of rodent models in translating pharmacodynamic analysis of trehalose for development of human therapeutics.
Insights into the mechanism of oligodendrocyte protection and remyelination enhancement by the integrated stress response
Authors: Chen Yanan , Quan Songhua , Patil Vaibhav , Kunjamma Rejani B. , Tokars Haley M. , Leisten Eric D. , Chan Jonah , Wong Yvette , Popko Brian
Published: January 2023

CNS inflammation triggers activation of the integrated stress response (ISR). We previously reported that prolonging the ISR protects remyelinating oligodendrocytes and promotes remyelination in the presence of inflammation (Chen et al.,eLife, 2021). However, the exact mechanisms through which this occurs remain unknown. Here, we investigated whether the ISR modulator Sephin1 in combination with the oligodendrocyte differentiation enhancing reagent bazedoxifene (BZA) is able to accelerate remyelination under inflammation, and the underlying mechanisms mediating this pathway. We find that the combined treatment of Sephin1 and BZA is sufficient to accelerate early-stage remyelination in mice with ectopic IFN-γ expression in the CNS. IFN-γ, which is a critical inflammatory cytokine in multiple sclerosis (MS), inhibits oligodendrocyte precursor cell (OPC) differentiation in culture and triggers a mild ISR. Mechanistically, we further show that BZA promotes OPC differentiation in the presence of IFN-γ, while Sephin1 enhances the IFN-γ-induced ISR by reducing protein synthesis and increasing RNA stress granule formation in differentiating oligodendrocytes. Finally, the ISR suppressor 2BAct is able to partially lessen the beneficial effect of Sephin1 on disease progression, in an MS mouse model of experimental autoimmune encephalitis (EAE). Overall, our findings uncover distinct mechanisms of action of BZA and Sephin1 on oligodendrocyte lineage cells under inflammatory stress, suggesting that a combination therapy may effectively promote restoring neuronal function in MS patients.
A universal stress protein is essential for the survival ofMycobacterium tuberculosis
Authors: Banerjee Arka , Chakraborty Moubani , Sharma Suruchi , Chaturvedi Ruchi , Bose Avipsa , Biswas Priyanka , Singh Amit , Visweswariah Sandhya S.
Published: January 2023

Mycobacterium tuberculosisemploys several signaling pathways to regulate its cellular physiology and survival within the host. Mycobacterial genomes encode multiple adenylyl cyclases and cAMP effector proteins, underscoring the diverse ways in which these bacteria utilize cAMP. We have earlier identified universal stress proteins (USP), Rv1636 and MSMEG_3811 inM. tuberculosisandM. smegmatisrespectively, as abundantly expressed, novel cAMP-binding proteins. In this study, we show that these USPs may function to regulate cAMP signaling by direct sequestration of the second messenger. In slow-growing mycobacteria, concentrations of Rv1636 were equivalent to the amounts of cAMP present in the cell, and overexpression of Rv1636 inM. smegmatisincreased levels of ‘bound’ cAMP. Rv1636 is secreted via the SecA2 secretion system inM. tuberculosisbut is not directly responsible for the efflux of cAMP from the cell. Whilemsmeg_3811could be readily deleted from the genome ofM. smegmatis, we find that therv1636gene is essential for growth ofM. tuberculosis, and this functionality depends on the cAMP-binding ability of Rv1636. This is the first evidence of a ‘sink’ for any second messenger in bacterial signaling that would allow mycobacterial cells to regulate the available intracellular ‘free’ pool of cAMP.
Structural and regulatory insights into the glideosome-associated connector fromToxoplasma gondii
Authors: Kumar Amit , Vadas Oscar , Dos Santos Pacheco Nicolas , Zhang Xu , Chao Kin , Darvill Nicolas , Rasmussen Helena Ø. , Xu Yingqi , Lin Gloria , Stylianou Fisentzos A , Pedersen Jan Skov , Rouse Sarah L. , Morgan Marc L. , Soldati-Favre Dominique , Matthews Steve
Published: January 2023

The phylum of Apicomplexa groups intracellular parasites that employ substratedependent gliding motility to invade host cells, egress from the infected cells and cross biological barriers. The glideosome associated connector (GAC) is a conserved protein essential to this process. GAC facilitates the association of actin filaments with surface transmembrane adhesins and the efficient transmission of the force generated by myosin translocation of actin to the cell surface substrate. Here, we present the crystal structure ofToxoplasma gondiiGAC and reveal a unique, supercoiled armadillo repeat region that adopts a closed ring conformation. Characterisation of the membrane binding interface within the C-terminal PH domain as well as an N-terminal fragment necessary for association with F-actin suggest that GAC adopts multiple conformations. A multi-conformational model for assembly of GAC within the glideosome is proposed.
Caltubin regulates microtubule stability via Ca2+-dependent mechanisms favouring neurite regrowth
Authors: Barszczyk Andrew , Bandura Julia , Zhang Qi , Wang Haitao , Deurloo Marielle , Ahmed Yasmin , Dong Aiping , Meister Paul , Lee Jeffrey , Sun Hong-Shuo , Tong Yufeng , Feng Zhong-Ping
Published: January 2023

Microtubule regulation is highly controlled in nerve regeneration. Caltubin, a novel Lymnaea stagnalis protein, contains putative EF-hand calcium-binding motifs and promotes neuronal outgrowth in Lymnaea and mouse. Here, we generated cell-permeable caltubin proteins to investigate mechanisms underlying this effect. We observed increased neurite extension and outgrowth following injury in caltubin-treated mouse neurons compared to vehicle controls. Purified caltubin bound α-tubulin between its L391-V405 amino acids and promoted microtubule assembly. Caltubin competitively inhibited binding of tubulin tyrosine ligase, which catalyzes tubulin retyrosination, and increased the ratio of detyrosinated to tyrosinated tubulin. Our crystal structure analysis confirmed that caltubin has four Ca2+-binding EF-hand motifs, like calmodulin but has distinct peptide binding domains. Our work suggests a unique Ca2+-dependent regulatory mechanism of microtubule assembly by caltubin. This may represent an essential mechanism of axonal regulation, which may optimize its activity in response to various calcium states, both physiological and following injury.
N-glycosylation engineering in chimeric antigen receptor T cells enhances anti-tumor activity
Authors: De Bousser Elien , Festjens Nele , Meuris Leander , Plets Evelyn , Van Hecke Annelies , Wyseure Elise , De Munter Stijn , Vandekerckhove Bart , Callewaert Nico
Published: January 2023

Recently, chimeric antigen receptor (CAR) T cell technology has revolutionized cancer immunotherapy. This strategy uses synthetic CARs to redirect T cells to specific antigens expressed on the surface of tumor cells. Despite impressive progress in the treatment of hematological malignancies with CAR T cells, scientific challenges still remain for use of CAR T cell therapy to treat solid tumors. This is mainly due to the hostile tumor microenvironment and CAR-related toxicities. As the glycans decorating the T cell surface are implicated in T cell activation, differentiation, proliferation, and in the interaction of human T cells with tumor cells, we studied the role of human T cell glycosylation in more depth by manipulating their glycome. In this context, there isin vitroevidence that β-galactoside binding lectins (Galectins) can have a strong impact on the functionality of tumor-infiltrating T cells. The high-affinity poly-LacNAc N-linked galectin ligands are mainly synthesized onto the β1,6-GlcNAc branch introduced by N-acetylglucosaminyltransferase V (GnTV, encoded byMgat5). We showed that knocking outMgat5in CD70 targeting CAR T cells leads to lower densities of poly-LacNAc modifications on the CAR T cell surface. Most interestingly, our results indicate that MGAT5 KO CD70 CAR T cells show enhanced potency to control primary tumors and relapses.
Pot1 promotes telomere DNA replication via the Stn1-Ten1 complex in fission yeast
Authors: Carvalho Borges Pâmela C. , Escandell Jose Miguel , Matmati Samah , Coulon Stéphane , Ferreira Miguel Godinho
Published: January 2023

Telomeres are nucleoprotein complexes that protect the chromosome-ends from eliciting DNA repair while ensuring their complete duplication. Pot1 is a subunit of telomere capping complex that binds to the G-rich overhang and inhibits the activation of DNA damage checkpoints. In this study, we explore new functions of fission yeast Pot1 by using apot1-1temperature sensitive mutant. We show thatpot1inactivation impairs telomere DNA replication resulting in the accumulation of ssDNA leading to the complete loss of telomeric DNA. Recruitment of Stn1 to telomeres, an auxiliary factor of DNA lagging strand synthesis, is reduced inpot1-1mutants and overexpression of Stn1 rescues loss of telomeres and cell viability at restrictive temperature. We propose that Pot1 plays a crucial function in telomere DNA replication by recruiting Stn1-Ten1 and Polα-primase complex to telomeres, thus promoting lagging-strand DNA synthesis at stalled replication forks.
Peptidoglycan remodeling in response to cell wall acting antibiotics inBacillus subtilis
Authors: Cornilleau Charlène , Alvarez Laura , Wegler Christine , Billaudeau Cyrille , Cava Felipe , Carballido-López Rut
Published: January 2023

Most bacteria are encased into a load-bearing rigid framework, the cell wall (CW). The peptidoglycan (PG) layer, a network composed of glycan strands cross-linked by stem peptides, is the main component of the CW. During PG synthesis, precursors are first synthetized intracellularly, before being incorporated into the existing PG meshwork by transglycosylation (TG) and transpeptidation (TP) reactions. Covalent modifications of the PG meshwork such as amidation and acetylation participate in PG homeostasis by regulating PG-associated enzymes like PG hydrolases.

Because of its essential role, PG synthesis represents a primary target for antibiotic action. Here, we investigated the effect on PG composition of antibiotics targeting intracellular and extracellular steps of PG synthesis: inhibitors of PG precursors synthesis (fosfomycin, D-cycloserine, bacitracin and tunicamycin) and TG/TP inhibitors (vancomycin and penicillin G), respectively. Our study revealed interesting correlations between crosslinking and both de-N-acetylation and amidation of the sacculus. A thorough analysis of muropeptides composition put into light an unexpected anti-correlation between the degree of PG crosslinking and accumulation of de-amidated disaccharide-tripeptide monomer subunit (M3) in the presence of TP inhibitors. We confirmed these observations by analyzing mutants of the PG synthesis pathway.
Nonmotor symptoms associated with progressive loss of dopaminergic neurons in a mouse model of Parkinson’s disease
Authors: Radlicka Anna , Jabłońska Judyta , Lenarczyk Michał , Szumiec Łukasz , Harda Zofia , Bagińska Monika , Pera Joanna , Kreiner Grzegorz , Wójcik Daniel , Rodriguez Parkitna Jan
Published: January 2023

Parkinson’s disease (PD) is characterized by three main motor symptoms: bradykinesia, rigidity and tremor. PD is also associated with diverse nonmotor symptoms that may develop in parallel or precede motor dysfunctions, ranging from autonomic system dysfunctions and impaired sensory perception to cognitive deficits and depression. Here, we examine the role of the progressive loss of dopaminergic transmission in behaviors related to the nonmotor symptoms of PD in a mouse model of the disease (the TIF-IADATCreERT2strain). We found that in the period from 5 to 12 weeks after the induction of a gradual loss of dopaminergic neurons, mild motor symptoms became detectable, including changes in the distance between paws while standing as well as the step cadence and sequence. Male mutant mice showed no apparent changes in olfactory acuity, no anhedonia-like behaviors, and normal learning in an instrumental task; however, a pronounced increase in the number of operant responses performed was noted. Similarly, female mice with progressive dopaminergic neuron degeneration showed normal learning in the probabilistic reversal learning task and no loss of sweet-taste preference, but again, a robustly higher number of choices were performed in the task. In both males and females, the higher number of instrumental responses did not affect the accuracy or the fraction of rewarded responses. Taken together, these data reveal discrete, dopamine-dependent nonmotor symptoms that emerge in the early stages of dopaminergic neuron degeneration.
Mechanism of an alternative splicing switch mediated by cell-specific and general splicing regulators
Authors: Yang Yi , Lee Giselle C , Nakagaki-Silva Erick , Huang Yuling , Peacey Matthew , Partridge Ruth , Gooding Clare , Smith Christopher WJ
Published: January 2023

Alternative pre-mRNA splicing is regulated by RNA binding proteins (RBPs) that activate or repress regulated splice sites. Repressive RBPs bind stably to target RNAs via multivalent interactions, which can be achieved by both homo-oligomerization and by interactions with other RBPs mediated by intrinsically disordered regions (IDRs). Cell-specific splicing decisions commonly involve the action of widely expressed RBPs that can bind around target exons, but without effect in the absence of a key cell-specific regulator. To address how cell-specific regulators collaborate with constitutive RBPs in alternative splicing regulation we used the smooth-muscle specific regulator RBPMS. Recombinant RBPMS is sufficient to switch cell specific alternative splicing ofTpm1exon 3 in cell free assays by remodelling ribonucleprotein complexes and preventing assembly of ATP-dependent splicing complexes. This activity depends upon its C-terminal IDR, which facilitates dynamic higher-order self-assembly, cooperative binding to multivalent RNA, and interactions with other splicing co-regulators, including MBNL1 and RBFOX2. Our data show how a cell-specific RBP can co-opt more widely expressed regulatory RBPs to facilitate cooperative assembly of stable cell-specific regulatory complexes.
Integration of spatially opposing cues by a single interneuron guides decision making inC. elegans
Authors: Gat Asaf , Pechuk Vladyslava , Peedikayil-Kurien Sonu , Goldman Gal , Lubliner Jazz , Karimi Shadi , Krieg Michael , Oren-Suissa Meital
Published: January 2023

The capacity of animals to integrate and respond to multiple hazardous stimuli in the surroundings is crucial for their survival. In mammals, complex evaluations of the environment require large numbers and different subtypes of neurons. The nematodeC. elegansavoid hazardous chemicals they encounter by reversing their direction of movement. How does the worms’ compact nervous system processes the spatial information and directs the change of motion? We show here that a single interneuron, AVA, receives glutamatergic excitatory signals from head sensory neurons and glutamatergic inhibitory signals from the tail sensory neurons. AVA integrates the spatially distinct and opposing cues, whose output instructs the animal’s behavioral decision. We further find that the differential activation of AVA from the head and tail stems from distinct anatomical localization of inhibitory and excitatory glutamate-gated receptors along the AVA process, and from different threshold sensitivities of the sensory neurons to aversive stimuli. Our results thus uncover a cellular mechanism that mediates spatial computation of nociceptive cues for efficient decision-making inC. elegans.
In situ compression of micropillars under coherent X-ray diffraction: a case study of experimental and data-analysis constraints
Authors: Godard Pierre , Verezhak Mariana , Sadat Tarik , Mignerot Florent , Jacques Vincent L. R. , Le Bolloc'h David , Richter Carsten , Berenguer Felisa , Diaz Ana , Van Petegem Steven , Renault Pierre-Olivier , Thilly Ludovic
Published: January 2023

Micropillar compression is a method of choice to understand mechanics at small scale. It is mainly studied with electron microscopy or white-beam micro-Laue X-ray diffraction. The aim of the present article is to show the possibilities of the use of diffraction with a coherent X-ray beam. InSb micropillars in epitaxy with their pedestals (i.e. their support) are studied in situ during compression. Firstly, an experiment using a collimated beam matching the pillar size allows determination of when the sample enters the plastic regime, independently of small defects induced by experimental artefacts. A second experiment deals with scanning X-ray diffraction maps with a nano-focused beam; despite the coherence of the beam, the contributions from the pedestal and from the micropillar in the diffraction patterns can be separated, making possible a spatially resolved study of the plastic strain fields. A quantitative measurement of the elastic strain field is nevertheless hampered by the fact that the pillar diffracts at the same angles as the pedestal. Finally, no image reconstructions were possible in these experiments, either in situ due to a blurring of the fringes during loading or post-mortem because the defect density after yielding was too high. However, it is shown how to determine the elastic bending of the pillar in the elastic regime. Bending angles of around 0.3° are found, and a method to estimate the sample's radius of curvature is suggested.
Religious, contextual and media influence: determinants of the representation of female tour guides in travel agencies
Authors: Mousa Mohamed , Abdelgaffar Hala , Salem Islam Elbayoumi , Elbaz Ahmed Mohamed , Chaouali Walid
Published: January 2023

Purpose

This study aims to investigate the perceptions of female tour guides’ lower and top levels of management in travel agencies about how misunderstanding Islam and its culture may engender the poor representation of women in the tour guide profession.

Design/methodology/approach

A qualitative research method is used, and semi-structured interviews were conducted with 32 full-time female tour guides working at several travel agencies in Egypt. Thematic analysis helped extract main ideas from the transcripts.

Findings

The representation of female tour guides in travel agencies is shaped by the following three determinants: religious (familial obligations and marital status), contextual (nature of tour guide activities, poor representation of women in senior tourism-related jobs, cronyism, sexual harassment and spread of foreign female tour guides) and media influence. Understanding these three factors may enable a more comprehensive representation of female tour guides.

Practical implications

Female tour guides could work closely with tourism policymakers in Egypt to shape the media messages about them. This might include elaborating on the main challenges faced by female tour guides. Social support from families and friends may allow female tour guides more freedom and empowerment.

Originality/value

This study contributes by filling a gap in tourism, human resources management and gender studies in which empirical studies on the representation of females in travel agencies have been limited so far.
Analyzing the commonalities between Islamic social finance and sustainable development goals
Authors: Shahid Mohammad , Sulub Yasin Ahmed , Mohtesham Mohammed Meeran Jasir , Abdullah Mohammad
Published: January 2023

Purpose

This study aims to explore commonalities and differences between Islamic social finance (ISF) and sustainable development goals (SDGs).

Design/methodology/approach

The study has adopted a qualitative library-based research method, and the secondary data is collected through the available literature on the topic.

Findings

This study concludes that the majority of SDGs are compatible with ISF. Moreover, it finds that the global ISF possesses adequate financial resources to assist Muslim majority nations in achieving some of the most critical and urgent SDGs on time.

Research limitations/implications

The scope of this study is confined to examining the possible role of ISF in achieving many of the most pressing development goals aligned with the SDGs. To maintain coherence within the study’s focus, this paper makes no comparisons between the ISF and other types of endowments/charities.

Practical implications

This paper outlines an agenda for the ISF-led development strategy and makes some crucial recommendations on how the global ISF might potentially lead the charge of Islamic charities in achieving the SDGs in Muslim majority nations.

Originality/value

This paper adds original value to the available literature on the potential of ISF and SDGs in the arena of development. The paper analyses the role of ISF in achieving the SDGs.
Civil society organisations counter conduct about the Agyapa deal of Ghana
Authors: Nsor-Ambala Randolph
Published: January 2023

Purpose

The purpose of this paper is to test if activism by civil society organisations (CSOs hereafter) in successfully mobilising resistance to the Government of Ghana “collateralization” of gold resources and other mineral royalties in 2020 (dubbed the “Agyapa deal”) espouse tenets of Foucault’s (2009) “governmentality” and “counter conduct” dispositions.

Design/methodology/approach

This paper draws on Dean’s (1999) discussion of government analytics to highlight how CSO activism can simultaneously challenge government practice and share in it. This paper uses an evidence-based and interpretive qualitative content analysis approach. This paper relied on secondary data sources from 1 January 2020 to 21 August 2021. Data collection involved an extensive review of secondary materials concerning the Agyapa deal, relying on the author's local knowledge to identify the likely sources of information.

Findings

This paper exposes how the counteractions of CSOs, underpinned by the desire for so-called “good governance”, invariably extend governmentality and other neo-liberal ideals. In this case, CSOs' actions espoused the ideals of marketisation, extended governable spaces, engrained subjectivation and treated citizens as incapable of formulating and advancing their desires without overt help. Secondly, it provides evidence that massive deployment of accountability and other calculable practices, however wilful, complement efforts at shaping public opinion.

Practical implications

CSO counter-conduct is merely symbolic rather than substantive. Substantive counter-conduct requires the citizenry to actively lead the problematisation process, holding CSOs accountable for acting on their behalf. The current trajectory where CSO accountability is primarily to their international financiers, predominantly neo-liberal advocates, raises questions about “in whose interest they seek another form of governance?” Practically, the splinter of interests that may emanate from citizenry directly led counter-conduct can affect garnering the critical mass needed to force a policy change. That said, however, there is a case for citizenry “making themselves” rather than “being made” within the governmentality process.

Originality/value

To the best of the author’s knowledge, this is the first application of the Foucauldian and Dean framework to a data set from Ghana.
Word-of-mouth in business-to-business marketing: a systematic review and future research directions
Authors: Ishii Ryuta , Kikumori Mai
Published: January 2023

Purpose

The purpose of this study is to review and analyze the status of word-of-mouth (WOM) research in the business-to-business (B2B) context and discuss and identify new possible future directions.

Design/methodology/approach

A systematic review was conducted and 36 articles on B2B WOM were collected to evaluate the current state of the literature and clarify possible future research directions.

Findings

This thematic analysis categorize these articles into three themes: WOM generation, WOM usage and reference marketing. Under each theme, the authors reveal research findings unique to B2B research and different from business-to-consumer (B2C) WOM research. This study identifies several research questions that should be addressed by future research.

Originality/value

Both academic researchers and business practitioners recognize that WOM plays an essential role in B2B marketing. However, no review paper focuses on WOM in the B2B context. Findings in the B2C WOM literature suggest that WOM substantially influences firms’ performance, but that managers cannot simply attempt to extrapolate B2C findings to the B2B arena. By synthesizing and assessing prior research on WOM in the B2B context, this study contributes to a better understanding of the B2B WOM phenomenon and facilitates future research on this topic.
Does being religious or not matter? A qualitative investigation of community fundraising events
Authors: Kocaman Rıdvan , Özmen Müjdat , Erdoğan B. Zafer
Published: January 2023

Purpose

In the extant literature, the concepts of charity and philanthropy have been differentiated based on the belief that charity stems from religious motivations and philanthropy is often secular in origin. Accordingly, this paper aims to investigate whether there is a distinction between managerial practices regarding the given concepts as emphasized in the conceptual discussions.

Design/methodology/approach

To see the managerial practices, the authors determined bazaars, community fundraising events organized by nonprofit organizations (NPOs), as the research field. Then, this study followed the general systematic of qualitative research. Accordingly, the authors conducted 44 interviews with experienced bazaar organizers from 10 NPOs in total. Furthermore, four days of participant observation with field notes were made in each bazaar, which lasted from 7 to 10 days. This study also used archival data as a secondary data source and then analyzed all data with a content analysis technique.

Findings

This study found that the field practices mainly do not support the distinction drawn over the conceptual discussions. Both concepts are nouns describing the act of giving and helping the needy. They are actively performed based on different motives (religion-based and secular).

Originality/value

The relevant distinction is limited to the conceptual discussions and has not been supported by the findings obtained from the field. Also, most of the studies on helping were carried out in the Western context. Studies conducted outside these cultures are quite limited. The value of the current study lies in the fact that it was conducted in a cultural context different from the Western cultures and paves the pathway for future research.