bluuebunny/crossref_metadata_2025 huggingface dataset:
Sun compass neurons are tuned to migratory orientation in monarch butterflies
Authors: Nguyen Tu Anh Thi , Beetz M. Jerome , Merlin Christine , el Jundi Basil
Published: February 2021

Every autumn, monarch butterflies migrate from North America to their overwintering sites in Central Mexico. To maintain their southward direction, these butterflies rely on celestial cues as orientation references. The position of the sun combined with additional skylight cues are integrated in the central complex, a region in the butterfly's brain that acts as an internal compass. However, the central complex does not solely guide the butterflies on their migration but also helps monarchs in their non-migratory form manoeuvre on foraging trips through their habitat. By comparing the activity of input neurons of the central complex between migratory and non-migratory butterflies, we investigated how a different lifestyle affects the coding of orientation information in the brain. During recording, we presented the animals with different simulated celestial cues and found that the encoding of the sun was narrower in migratory compared to non-migratory butterflies. This feature might reflect the need of the migratory monarchs to rely on a precise sun compass to keep their direction during their journey. Taken together, our study sheds light on the neural coding of celestial cues and provides insights into how a compass is adapted in migratory animals to successfully steer them to their destination.
Autocrine and paracrine interferon signalling as ‘ring vaccination’ and ‘contact tracing’ strategies to suppress virus infection in a host
Authors: Michael Lavigne G. , Russell Hayley , Sherry Barbara , Ke Ruian
Published: February 2021

The innate immune response, particularly the interferon response, represents a first line of defence against viral infections. The interferon molecules produced from infected cells act through autocrine and paracrine signalling to turn host cells into an antiviral state. Although the molecular mechanisms of IFN signalling have been well characterized, how the interferon response collectively contribute to the regulation of host cells to stop or suppress viral infection during early infection remain unclear. Here, we use mathematical models to delineate the roles of the autocrine and the paracrine signalling, and show that their impacts on viral spread are dependent on how infection proceeds. In particular, we found that when infection is well-mixed, the paracrine signalling is not as effective; by contrast, when infection spreads in a spatial manner, a likely scenario during initial infection in tissue, the paracrine signalling can impede the spread of infection by decreasing the number of susceptible cells close to the site of infection. Furthermore, we argue that the interferon response can be seen as a parallel to population-level epidemic prevention strategies such as ‘contact tracing’ or ‘ring vaccination’. Thus, our results here may have implications for the outbreak control at the population scale more broadly.
High false-positive rate of fluorodeoxyglucose positron emission tomography to detect lymph node metastasis in microinvasive cervical cancer after conization
Authors: Kim Kidong , Kim Hayeon , Lee Hwajung , Lee Keun Ho , Lee Banghyun , Choi ChelHun , Shim Seung-Hyuk , Lee Jong-Min , Kim Miseon , Lee Jung-Yun
Published: February 2021

We aimed to estimate the positive predictive value of fluorodeoxyglucose positron emission tomography (FDG PET) to detect lymph node metastasis in patients with microinvasive cervical cancer who recently underwent conization. We retrospectively collected data of patients fulfilling the following criteria: 1) cervical cancer stage 1A1 (by FIGO staging revised in 1994) without invasion of the lymphovascular space diagnosed by conization from September 2008 to July 2018, 2) FDG PET within 3 months after diagnosis, 3) lymph node metastasis suspected by FDG PET, and 4) histologic confirmation or follow-up imaging study for suspected lymph node metastasis. Lymph node metastasis was suspected in 31 regions in 18 patients; however, no true metastasis was found. In conclusion, lymph node metastasis suspected by FDG PET in microinvasive cervical cancer after conization might be false positive. Lymph node dissection should not be performed for such patients.
Acceptance of COVID-19 Vaccine in Pakistan Among Health Care Workers
Authors: Malik Asmara , Malik Jahanzeb , Ishaq Uzma
Published: February 2021

Objective

Acceptance of the COVID-19 vaccine will impart a pivotal role in eradicating the virus. In Pakistan, health care workers (HCWs) are the first group to receive vaccination. This survey aimed at the level of acceptance to the COVID-19 vaccine and predictors of non-acceptance in HCWs.

Method

This was a cross-sectional study design and data were collected through 3rd December 2020 and February 14th, 2021. An English questionnaire was distributed through social media platforms and administration of affiliate hospitals along with snowball sampling for private hospitals.

Results

Out of 5,237 responses, 3,679 (70.2%) accepted COVID-19 vaccination and 1,284 (24.5%) wanted to delay until more data was available. Only 5.2% of HCWs rejected being vaccinated. Vaccine acceptance was more in young (76%) and female gender (63.3%) who worked in a tertiary care hospital (51.2%) and were direct patient care providers (61.3%). The reason for rejection in females was doubtful vaccine effectiveness (31.48%) while males rejected due to prior COVID-19 exposure (42.19%) and side effect profile of the vaccine (33.17%). Logistic regression analysis demonstrated age between 51-60 years, female gender, Pashtuns, those working in the specialty of medicine and allied, taking direct care of COVID-19 patients, higher education, and prior OCVID-19 infection as the predictors for acceptance or rejection of COVID-19 vaccine.

Conclusion

A high overall acceptance rate was observed among HCWs, favoring a successful nationwide vaccination program in Pakistan.
Impact of the Tier system on SARS-CoV-2 transmission in the UK between the first and second national lockdowns
Authors: Laydon Daniel J , Mishra Swapnil , Hinsley Wes R , Samartsidis Pantelis , Flaxman Seth , Gandy Axel , Ferguson Neil M , Bhatt Samir
Published: February 2021

Objective

Measure the effects of the Tier system on the COVID-19 pandemic in the UK between the first and second national lockdowns, before the emergence of the B.1.1.7 variant of concern.

Design

Modelling study combining estimates of the real-time reproduction number Rt (derived from UK case, death and serological survey data) with publicly available data on regional non-pharmaceutical interventions. We fit a Bayesian hierarchical model with latent factors using these quantities, to account for broader national trends in addition to subnational effects from Tiers.

Setting

The UK at Lower Tier Local Authority (LTLA) level.

Primary and secondary outcome measures

Reduction in real-time reproduction number Rt.

Results

Nationally, transmission increased between July and late September, regional differences notwithstanding. Immediately prior to the introduction of the tier system, Rt averaged 1.3 (0.9 – 1.6) across LTLAs, but declined to an average of 1.1 (0.86 – 1.42) two weeks later. Decline in transmission was not solely attributable to Tiers. Tier 1 had negligible effects. Tiers 2 and 3 respectively reduced transmission by 6% (5%-7%) and 23% (21%-25%). 93% of LTLAs would have begun to suppress their epidemics if every LTLA had gone into Tier 3 by the second national lockdown, whereas only 29% did so in reality.

Conclusions

The relatively small effect sizes found in this analysis demonstrate that interventions at least as stringent as Tier 3 are required to suppress transmission, especially considering more transmissible variants, at least until effective vaccination is widespread or much greater population immunity has amassed.

Strengths and limitations of this study

First study to measure effects of UK Tier system for SARS-CoV-2 control at national and regional level.

Model makes minimal assumptions and is primarily data driven.

Insufficient statistical power to estimate effects of individual interventions that comprise Tiers, or their interaction.

Estimates show that Tiers 1 and 2 are insufficient to suppress transmission, at least until widespread population immunity has amassed. Emergence of more transmissible variants of concern unfortunately supports this conclusion.
PRESENT SITUATION OF SUICIDE IN BANGLADESH: A REVIEW
Authors: Ferdous Most. Zannatul , Alam A.S.M. Mahbubul
Published: February 2021

The most important global cause of mortality is suicide. It is often neglected by researchers, health professionals, health policymakers, and the medical profession. This review was aimed to provide a narrative understanding of the present situation of suicide in Bangladesh based on the existing literature. We conducted a review combining articles and abstracts with full HTML and PDF format. We searched PubMed, PubMed Central, Google Scholar, ScienceDirect and BanglaJOL, google using multiple terms related to suicide without any date boundary and without any basis of types of studies, that is, all types of studies were scrutinized. Finally, 16 articles were selected for review. Report suggested that every day almost 32 people commit suicide in 2019 which was 29 and 30 in 2015 and 2017 respectively. The mortality rate of suicide found 39.6 per 100,000 in Bangladesh. The most common method is hanging followed by poisoning and jumping under the train. The most prevalent age group is age under 40 years. The rate of suicide in children is also increasing. In contrast to most Asian countries, more Bangladeshi women commit suicide than men. The mean age of male and female were 28.86 ± 11.27 years and 25.31 ± 7.70 years respectively. The most common associated factors of suicide are younger age, lower education, students, nuclear family, family history of suicide, use substance, problem in workplace, financial constraints, affair, domestic violence, divorce, and physical illness. Most of the suicidal event occurred at night, followed by morning (6 am–12 am), and evening. It’s a criminal offence in Bangladesh. The source of information is mainly police, forensic reports, media and courts. Till now there is no nationwide survey of suicide is conducted. Besides, suicide surveillance strategy is yet to be established. Suicide is a neglected and under attended public health problem in Bangladesh with few research and paucity of literature. Now nationwide survey conduction and establishment of national suicide surveillance are a time demanded step.
Naegleria’smitotic spindles are built from unique tubulins and highlight core spindle features
Authors: Velle Katrina B , Trupinić Monika , Ivec Arian , Swafford Andrew , Nolton Emily , Rice Luke , Tolić Iva M. , Fritz-Laylin Lillian K , Wadsworth Patricia
Published: February 2021

Naegleria gruberiis a unicellular eukaryote whose evolutionary distance from animals and fungi has made it useful for developing hypotheses about the last common eukaryotic ancestor.Naegleriaamoebae lack a cytoplasmic microtubule cytoskeleton and assemble microtubules only during mitosis, and thus provides a unique system to study the evolution and functional specificity of mitotic tubulins and the resulting spindle. Previous studies showed thatNaegleriaamoebae express a divergent α-tubulin during mitosis and we now show thatNaegleriaamoebae express a second mitotic α- and two mitotic β-tubulins. The mitotic tubulins are evolutionarily divergent relative to typical α- and β- tubulins, contain residues that suggest distinct microtubule properties, and may represent drug targets for the “brain-eating amoeba”Naegleria fowleri. Using quantitative light microscopy, we find thatNaegleria’s mitotic spindle is a distinctive barrel-like structure built from a ring of microtubule bundles. Similar to those of other species,Naegleria’s spindle is twisted and its length increases during mitosis suggesting that these aspects of mitosis are ancestral features. Because bundle numbers change during metaphase, we hypothesize that the initial bundles represent kinetochore fibers, and secondary bundles function as bridging fibers.
Single Unit Analysis and Wide-Field Imaging Reveal Alterations in Excitatory and Inhibitory Neurons in Glioma
Authors: Gill Brian J.A. , Khan Farhan A. , Merricks Edward M. , Goldberg Alexander R. , Wu Xiaoping , Sosunov Alexander A. , Sudhakar Tejaswi D. , Liou Jyun-you , Dovas Athanassios , McKhann Guy M. , Canoll Peter , Schevon Catherine
Published: February 2021

Several studies have attributed the development of tumor-associated seizures to an excitatory-inhibitory imbalance, highlighting the importance of resolving the spatiotemporal interplay of different neuronal populations within the peritumoral microenvironment. We combined methods for microelectrode array recordings and single unit analysis during ictal events with wide-field optical mapping of pyramidal neurons in anex vivoacute slice model of diffusely infiltrating glioma in Thy1-GCaMP6f mice. This approach allowed for characterization of excitatory and inhibitory populations across an extended peritumoral cortical region. As expected, measures of excitability were increased in tumor-bearing slices compared to control. This was accompanied by marked functional alterations in single units classified as fast-spiking interneurons, including reduced firing, altered timing with respect to excitatory firing, and deficits in surround inhibition. Inhibiting mTOR with AZD8055 reversed these glioma-induced changes to excitatory and inhibitory neuronal populations, suggesting a prominent role for functional mechanisms linked to mTOR activation.
REPROGRAMMING CBX8-PRC1 FUNCTION WITH A POSITIVE ALLOSTERIC MODULATOR
Authors: Suh Junghyun L. , Bsteh Daniel , Si Yibo , Hart Bryce , Weaver Tyler M. , Pribitzer Carina , Lau Roy , Soni Shivani , Ogana Heather , Rectenwald Justin M. , Norris Jacqueline L. , Cholensky Stephanie H. , Sagum Cari , Umana Jessica D. , Li Dongxu , Hardy Brian , Bedford Mark T. , Mumenthaler Shannon M. , Lenz Heinz-Josef , Kim Yong-mi , Wang Gang Greg , Pearce Ken H. , James Lindsey I. , Kireev Dmitri B. , Musselman Catherine A. , Frye Stephen V. , Bell Oliver
Published: February 2021

ABSTRACT

Canonical targeting of Polycomb Repressive Complex 1 (PRC1) to repress developmental genes is mediated by cell type-specific, paralogous chromobox (CBX) proteins (CBX2, 4, 6, 7 and 8). Based on their central role in silencing and their misregulation associated with human disease including cancer, CBX proteins are attractive targets for small molecule chemical probe development. Here, we have used a quantitative and target-specific cellular assay to discover a potent positive allosteric modulator (PAM) of CBX8. The PAM activity of UNC7040 antagonizes H3K27me3 binding by CBX8 while increasing interactions with nucleic acids and participation in variant PRC1. We show that treatment with UNC7040 leads to efficient PRC1 chromatin eviction, loss of silencing and reduced proliferation across different cancer cell lines. Our discovery and characterization of UNC7040 not only revealed the most cellularly potent CBX8-specific chemical probe to date, but also corroborates a mechanism of polycomb regulation by non-histone lysine methylated interaction partners.
DeTOKI identifies and characterizes the dynamics of chromatin topologically associating domains in a single cell
Authors: Li Xiao , Zhang Zhihua
Published: February 2021

The human genome has a dynamic, well-organized hierarchical 3D architecture, including megabase-sized topologically associating domains (TAD). TADs are a key structure of the genome regulating nuclear processes, such as gene expression, DNA replication and damage repair. However, owing to a lack of proper computational tools, TADs have still not been systematically and reliably surveyed in single cells. In the present work, we developed a new algorithm todecodeTAD boundaries thatkeep chromatininteraction insulated (deTOKI) from ultra-sparse Hi-C data. By nonnegative matrix factorization, this novel algorithm seeks out for regions that insulate the genome into blocks with minimal chance of clustering. We found that deTOKI outperformed competing tools and that it reliably identified TADs with single-cell Hi-C (scHi-C) data. By applying deTOKI, we found that domain structures are prevalent in single cells. Further, although domain structures are highly dynamic between cells, TADs adhere to the ensemble, suggesting tight regulation of single-cell TADs. Finally, we found that the insulation properties of TAD boundaries have major effect on the epigenetic landscape in individual cells. In sum, deTOKI serves as a powerful tool for profiling TADs in single cells.
Host-specific gene expression as a tool for introduction success inNaupactusparthenogenetic weevils
Authors: Mackay-Smith Ava , Dornon Mary Kate , Lucier Rosalind , Okimoto Anna , de Sousa Flavia Mendonca , Rodriguero Marcela , Confalonieri Viviana , Lanteri Analia A. , Sequeira Andrea S.
Published: February 2021

Food resource access can mediate establishment success in invasive species, and generalist herbivorous insects are thought to rely on mechanisms of transcriptional plasticity to respond to dietary variation. While asexually reproducing invasives typically have low genetic variation, the twofold reproductive capacity of asexual organisms is a marked advantage for colonization. We studied host-related transcriptional acclimation in parthenogenetic, invasive, and polyphagous weevils:Naupactus cervinusandN. leucoloma. We analyzed patterns of gene expression in three gene categories that can mediate weevil-host plant interactions through identification of suitable host plants, short-term acclimation to host plant defenses, and long-term adaptation to host plant defenses and their pathogens. This approach employed comparative transcriptomic methods to investigate differentially expressed host detection, detoxification, immune defense genes, and pathway-level gene set enrichment. Our results show that weevil gene expression responses can be host plant-specific, and that elements of that response can be transgenerational. Some host plant groups, such as legumes, appear to be more taxing as they elicit a complex gene expression response which is both strong in intensity and specific in identity. However, the weevil response to taxing host plants shares many differentially expressed genes with other stressful situations, such as host plant cultivation conditions and transition to novel host, suggesting that there is an evolutionarily favorable shared gene expression regime for responding to different types of stressful situations. Modulating gene expression in the absence of other avenues for phenotypic adaptation may be an important mechanism of successful colonization for these introduced insects.
The Mammalian Cytosolic Type 2 (R)-β-hydroxybutyrate Dehydrogenase (BDH2) is 4-oxo-L-proline Reductase (EC 1.1.1.104)
Authors: Kwiatkowski Sebastian P. , Bozko Maria , Zarod Michal , Witecka Apolonia , Jagielski Adam K. , Drozak Jakub
Published: February 2021

The early studies on chicken embryos revealed that exposition to 4-oxo-L-proline resulted in the explicit increase in 4-hydroxy-L-proline content in their tissues. In 1962, 4-oxo-L-proline reductase, an enzyme responsible for the reduction of 4-oxo-L-proline, was partially purified from rabbit kidneys and characterized biochemically, but only recently the molecular identity of the enzyme has been unveiled in our laboratory. The present investigation reports the purification, identification as well as biochemical characterization of 4-oxo-L-proline reductase. The enzyme was purified from rat kidneys about 280-fold. Following mass spectrometry analysis of the purified protein preparation, the mammalian cytosolic type 2 (R)-β-hydroxybutyrate dehydrogenase (BDH2) emerged as the only meaningful candidate for the reductase. Rat and human BDH2 were expressed inE. coli, purified, and shown to catalyze the reversible reduction of 4-oxo-L-proline tocis-4-hydroxy-L-proline, as confirmed by chromatographic and mass spectrometry analysis. Specificity studies carried out on both enzymes showed that 4-oxo-L-proline was the best substrate, particularly the human enzyme acted with 9400-fold higher catalytic efficiencies on 4-oxo-L-proline than on (R)-β-hydroxybutyrate. Finally, HEK293T cells efficiently metabolized 4-oxo-L-proline tocis-4-hydroxy-L-proline and simultaneously accumulatedtrans-4-hydroxy-L-proline in the culture medium, suggesting that 4-oxo-L-proline is most likely an inhibitor oftrans-4-hydroxy-L-proline metabolism in human cells. We conclude that BDH2 is mammalian 4-oxo-L-proline reductase that converts 4-oxo-L-proline tocis-4-hydroxy-L-proline, and not totrans-4-hydroxy-L-proline as currently thought, and hypothesize that the enzyme may be considered as a potential source ofcis-4-hydroxy-L-proline in mammalian tissues.
Previous estradiol treatment during midlife maintains transcriptional regulation of memory-related proteins by ERα in the hippocampus in a rat model of menopause
Authors: Baumgartner Nina E. , Black Katelyn L. , McQuillen Shannon M. , Daniel Jill M.
Published: February 2021

Previous midlife estradiol treatment, like continuous treatment, improves memory and results in lasting increases in hippocampal levels of estrogen receptor (ER) α and ER-dependent transcription in ovariectomized rodents. We hypothesized that previous and continuous midlife estradiol act to specifically increase levels of nuclear ERα, resulting in transcriptional regulation of proteins that mediate estrogen effects on memory. Ovariectomized middle-aged rats received estradiol or vehicle capsule implants. After 40 days, rats initially receiving vehicle received another vehicle capsule (Vehicle). Rats initially receiving estradiol received either another estradiol (Continuous Estradiol) or a vehicle (Previous Estradiol) capsule. One month later, hippocampal genes and proteins were analyzed. Continuous and previous estradiol increased levels of nuclear, but not membrane or cytosolic ERα and had no effect onEsr1. Continuous and previous estradiol impacted gene expression and/or protein levels of mediators of estrogenic action on memory including ChAT, BDNF, and PSD-95. Findings demonstrate a long-lasting role for hippocampal ERα as a transcriptional regulator of memory following termination of previous estradiol treatment in a rat model of menopause.
Arkadia-SKI/SnoN signaling cascade differentially regulates TGF-β-induced iTreg and Th17 cell differentiation
Authors: Xu Hao , Wu Lin , Nguyen Henry , Mesa Kailin R. , Raghavan Varsha , Episkopou Vasso , Littman Dan R.
Published: February 2021

TGF-β signaling is fundamental for both Th17 and regulatory T cell (Treg) differentiation. However, these cells differ in requirements for downstream signaling components, such as various SMAD effectors, for their differentiation. To further characterize the mechanisms that distinguish TGF-β signaling requirements for Th17 and Treg cell differentiation, we investigated the role of Arkadia (RNF111), a RING type E3 ubiquitin ligase known to enhance TGF-β signaling during development. We find that Arkadia mediates the differentiation of induced-Treg (iTreg) but not Th17 cells bothin vitroandin vivo. Inactivation of Arkadia in CD4+T cells resulted in impairment of Treg cell differentiationin vitroand loss of RORγt+FOXP3+iTreg cells in the intestinal lamina propriain vivo, which increased susceptibility to microbiota-induced mucosal inflammation. Furthermore, genetic ablation of two substrates of Arkadia, the transcriptional co-repressors SKI and SnoN, rescuedin vitroandin vivoiTreg cell-differentiation of Arkadia-deficient cells. These results reveal distinct TGF-β signaling modules that govern Th17 and iTreg cell differentiation programs and that could be exploited therapeutically to selectively modulate T cell subsets in pathological settings such as autoimmunity or cancer.
SPIN - Species by Proteome INvestigation
Authors: Rüther P.L. , Husic I.M. , Bangsgaard P. , Murphy Gregersen K. , Pantmann P. , Carvalho M. , Godinho R.M. , Friedl L. , Cascalheira J. , Jørkov M.L.S. , Benedetti M.M.. , Haws J. , Bicho N. , Welker F. , Cappellini E. , Olsen J.V.
Published: February 2021

Genetic species determination has become an indispensable tool in forensics, archaeology, ecology, and food authentication. The available methods are either suited for detecting a single taxon across many samples or for screening a wide range of species across a few samples. Here, we introduce “Species by Proteome INvestigation” (SPIN), a proteomics workflow capable of querying over 150 mammalian species in 7.2 minutes of mass spectrometry (MS) analysis. Streamlined and automated sample preparation by protein aggregation capture, high-speed chromatography and data-independent acquisition, and a confident species inference algorithm facilitate processing hundreds of samples per day. We demonstrate the correct classification of known references, reproducible species identification in degraded Iron-Age material from Scandinavia, and test the limits of our methods with Middle and Upper Palaeolithic bones from Southern European sites with late Neanderthal occupation. While this initial study is focused on modern and archaeological mammalian bone, SPIN will be open and expandable with other biological tissues and taxa.
Neural correlates of subsequent memory-related gaze reinstatement
Authors: Wynn Jordana S. , Liu Zhong-Xu , Ryan Jennifer D.
Published: February 2021

Mounting evidence linking gaze reinstatement- the recapitulation of encoding-related gaze patterns during retrieval- to behavioral measures of memory suggests that eye movements play an important role in mnemonic processing. Yet, the nature of the gaze scanpath, including its informational content and neural correlates, has remained in question. In the present study, we examined eye movement and neural data from a recognition memory task to further elucidate the behavioral and neural bases of functional gaze reinstatement. Consistent with previous work, gaze reinstatement during retrieval of freely-viewed scene images was greater than chance and predictive of recognition memory performance. Gaze reinstatement was also associated with viewing of informationally salient image regions at encoding, suggesting that scanpaths may encode and contain high-level scene content. At the brain level, gaze reinstatement was predicted by encoding-related activity in the occipital pole and basal ganglia, neural regions associated with visual processing and oculomotor control. Finally, cross-voxel brain pattern similarity analysis revealed overlapping subsequent memory and subsequent gaze reinstatement modulation effects in the parahippocampal place area and hippocampus, in addition to the occipital pole and basal ganglia. Together, these findings suggest that encoding-related activity in brain regions associated with scene processing, oculomotor control, and memory supports the formation, and subsequent recapitulation, of functional scanpaths. More broadly, these findings lend support to Scanpath Theory’s assertion that eye movements both encode, and are themselves embedded in, mnemonic representations.
FORMATION OF LIPOFUSCIN-LIKE AUTOFLUORESCENT GRANULES IN THE RETINAL PIGMENT EPITHELIUM REQUIRES LYSOSOME DYSFUNCTION
Authors: Escrevente Cristina , Falcão Ana S. , Hall Michael J. , Lopes-da-Silva Mafalda , Antas Pedro , Mesquita Miguel M. , Ferreira Inês S. , Cardoso M. Helena , Fradinho Ana C. , Futter Clare E. , Tenreiro Sandra , Seabra Miguel C.
Published: February 2021

Purpose

We aim to characterize the pathways required for autofluorescent granule (AFG) formation by retinal pigment epithelium (RPE) cells using cultured monolayers.

Methods

We fed RPE monolayers in culture with a single pulse of photoreceptor outer segments (POS). After 24h the cells started accumulating AFGs similar to lipofuscinin vivo. Using this model, we used a variety of light and electron microscopical techniques, flow cytometry and western blot to analyze the formation of AFGs. We also generated a mutant RPE line lacking Cathepsin D by gene editing.

Results

AFGs appear to derive from incompletely digested POS-containing phagosomes and are surrounded after 72h by a single membrane containing lysosome markers. We show by various methods that lysosome-phagosome fusion is required for AFG formation but that impairment of lysosomal pH or catalytic activity, particularly Cathepsin D activity, enhances AF accumulation.

Conclusions

We conclude that lysosomal dysfunction results in incomplete POS degradation and AFG accumulation.
Understanding LRRK2 kinase activity in preclinical models and human subjects through quantitative analysis of LRRK2 and pRab10
Authors: Wang Xiang , Negrou Elvira , Maloney Michael T. , Bondar Vitaliy V , Andrews Shan V. , Montalban Manuel , Llapashtica Ceyda , Maciuca Romeo , Nguyen Hoang , Solanoy Hilda , Arguello Annie , Przybyla Laralynne , Moerke Nathan J. , Huntwork-Rodriguez Sarah , Henry Anastasia G.
Published: February 2021

Variants in theleucine-rich repeat kinase 2(LRRK2) gene are associated with increased risk for familial and sporadic Parkinson’s disease (PD). Pathogenic variants in LRRK2, including the common variant G2019S, result in increased LRRK2 kinase activity, supporting the therapeutic potential of LRRK2 kinase inhibitors for PD. To better understand the role of LRRK2 in disease and to support the clinical development of LRRK2 inhibitors, quantitative and high-throughput assays to measure LRRK2 levels and activity are needed. We developed and applied such assays to measure the levels of LRRK2 as well as the phosphorylation of LRRK2 itself or one of its substrates, Rab10 (pT73 Rab10). We observed increased LRRK2 activity in various cellular models of disease, including iPSC-derived microglia, as well as in human subjects carrying disease-linked variant in LRRK2 (G2019S). Capitalizing on the high-throughput and sensitive nature of these assays, we detected a significant reduction in LRRK2 activity in subjects carrying missense variants in LRRK2 associated with reduced disease risk. Finally, we optimized these assays to enable analysis of LRRK2 activity following inhibition in human peripheral blood mononuclear cells (PBMCs) and whole blood, demonstrating their potential utility as biomarkers to assess changes in LRRK2 expression and activity in the clinic.
Altered environmental perception by parental stress and depression vulnerability: impact on mothers and offspring
Authors: Alves Renata L. , Portugal Camila C. , Lopes Igor M. , Oliveira Pedro , Alves Cecília J. , Barbosa Fernando , Summavielle Teresa , Magalhães Ana
Published: February 2021

Depressive mothers often find the mother-child interaction to be challenging. Parental stress may further impair mother-child attachment, which may increase the risk of negative developmental consequences. We used rats with different vulnerability to depression (Wistar and Kyoto) to investigate the impact of stress (maternal separation-MS) on maternal behaviour and adolescent offspring cognition. MS in Kyoto dams increased pup-contact, resulting in higher oxytocin levels and lower anxiety-like behaviour after weaning, while worsening their adolescent offspring cognitive behaviour. Whereas MS in Wistar dams elicited higher quality of pup-directed behaviour, increasing Brain-Derived Neurotrophic Factor (BDNF) in the offspring, which seems to have prevented a negative impact on cognition. Hypothalamic oxytocin seems to impact the salience of the social environment cues (as negative for Kyoto) leading to different coping strategies. Our findings highlight the importance of contextual and individual factors in the understanding of the oxytocin role in modulating maternal behaviour and stress regulatory processes.
Genes with Specificity for Expression in the Round Cell Layer of the Growth Plate are Enriched in GWAS of Human Height
Authors: Renthal Nora E. , Nakka Priyanka , Baronas John M. , Kronenberg Henry M. , Hirschhorn Joel N.
Published: February 2021

Human adult height reflects the outcome of childhood skeletal growth. Growth plate (epiphyseal) chondrocytes are key determinants of height. As epiphyseal chondrocytes mature and proliferate, they pass through three developmental stages, which are organized into three distinct layers in the growth plate: 1) resting (round), 2) proliferative (flat), and 3) hypertrophic. Recent genome-wide association studies (GWAS) of human height identified numerous associated loci, which are enriched for genes expressed in growth plate chondrocytes. However, it remains unclear which specific genes expressed in which layers of the growth plate regulate skeletal growth and human height.

To connect the genetics of height and growth plate biology, we analyzed GWAS data through the lens of gene expression in the three dissected layers of murine newborn tibial growth plate. For each gene, we derived a specificity score for each growth plate layer and regressed these scores against gene-level p-values from recent height GWAS data. We found that specificity for expression in the round cell layer, which contains chondrocytes early in maturation, is significantly associated with height GWAS p-values (p=8.5×10−9); this association remains after conditioning on specificity for the other cell layers. The association also remains after conditioning on membership in an “OMIM gene set” (genes known to cause monogenic skeletal growth disorders,p<9.7×10−6). We replicated the association in RNA-seq data from maturing chondrocytes sampled at early and late time points during differentiationin vitro: we found that expression early in differentiation is significantly associated withp-values from height GWAS (p=6.1×10−10) and that this association remains after conditioning on expression at 10 days in culture and on the OMIM gene set (p<0.006). These findings newly implicate genes highlighted by GWAS of height and specifically expressed in the round cell layer as being potentially important regulators of skeletal biology.
Control of Ca2+signals by astrocyte nanoscale morphology at tripartite synapses
Authors: Denizot Audrey , Arizono Misa , Nägerl Valentin U. , Berry Hugues , De Schutter Erik
Published: February 2021

Much of the Ca2+activity in astrocytes is spatially restricted to microdomains and occurs in fine processes that form a complex anatomical meshwork, the so-called spongiform domain. A growing body of literature indicates that those astrocytic Ca2+signals can influence the activity of neuronal synapses and thus tune the flow of information through neuronal circuits. Because of technical difficulties in accessing the small spatial scale involved, the role of astrocyte morphology on Ca2+microdomain activity remains poorly understood. Here, we use computational tools and idealized 3D geometries of fine processes based on recent super-resolution microscopy data to investigate the mechanistic link between astrocytic nanoscale morphology and local Ca2+activity. Simulations demonstrate that the nano-morphology of astrocytic processes powerfully shapes the spatio-temporal properties of Ca2+signals and promotes local Ca2+activity. The model predicts that this effect is attenuated upon astrocytic swelling, hallmark of brain diseases, which we confirm experimentally in hypo-osmotic conditions. Upon repeated neurotransmitter release events, the model predicts that swelling hinders astrocytic signal propagation. Overall, this study highlights the influence of the complex morphology of astrocytes at the nanoscale and its remodeling in pathological conditions on neuron-astrocyte communication at so-called tripartite synapses, where astrocytic processes come into close contact with pre- and postsynaptic structures.

Table of Contents

Main Points

Astrocyte nano-morphology favors the compartmentalization of biochemical signals

This compartmentalization promotes local Ca2+activity and signal propagation robustness

In contrast, its pathological remodeling upon swelling attenuates Ca2+activity

Table of Contents Image

Figure 1:

Proposed mechanisms that regulate astrocytic Ca2+activity in perisynaptic astrocytic processes.

Our simulation results demonstrate that the nano-morphology of astrocytic processes, consisting in the alternation of nodes and shafts, favors the compartmentalization of biochemical signals. This compartmentalization promotes local Ca2+activity and signal propagation robustness. Astrocyte swelling, observed in pathological conditions such as brain injury, stroke and epilepsy, results in an increased shaft width without altering node size. Our results suggest that such pathological alterations of the nanoscale morphology of astrocytes result in a decreased local Ca2+activity, which we confirm experimentally in hypo-osmotic conditions. Upon repeated neuronal stimuli, we predict that swelling hinders astrocytic signal propagation. Overall, this study highlights the impact of astrocyte nano-morphology on astrocyte activity at tripartite synapses, in health and disease.
The developing mouse coronal suture at single-cell resolution
Authors: Farmer D’Juan T. , Mlcochova Hana , Zhou Yan , Koelling Nils , Wang Guanlin , Ashley Neil , Maxson Robert E , Wilkie Andrew O. M. , Crump J Gage , Twigg Stephen R.F.
Published: February 2021

Sutures separate the flat bones of the skull and enable coordinated growth of the brain and overlying cranium. To uncover the cellular diversity within sutures, we generated single-cell transcriptomes and performed extensive expression validation of the embryonic murine coronal suture. We identifyErgandPthlhas markers of osteogenic progenitors in sutures, and distinct pre-osteoblast signatures between the bone fronts and periosteum. In the ectocranial layers above the suture, we observe a ligament-like population spanning the frontal and parietal bones. In the dura mater underlying the suture, we detect a chondrocyte-like signature potentially linked to cartilage formation under pathological conditions. Genes mutated in coronal synostosis are preferentially expressed in proliferative osteogenic cells, as well as meningeal layers, suggesting discrete cell types that may be altered in different syndromes. This single-cell atlas provides a resource for understanding development of the coronal suture, the suture most commonly fused in monogenic craniosynostosis.
Reliance of neuronal gene expression on cohesin scales with chromatin loop length
Authors: Calderon Lesly , Weiss Felix D , Beagan Jonathan A , Oliveira Marta S , Wang Yi-Fang , Carroll Thomas , Dharmalingam Gopuraja , Gong Wanfeng , Tossell Kyoko , de Paola Vincenzo , Whilding Chad , Ungless Mark A. , Fisher Amanda G , Phillips-Cremins Jennifer E , Merkenschlager Matthias
Published: February 2021

Cohesin and CTCF are major drivers of 3D genome organization, but their role in neurons is still emerging. Here we show a prominent role for cohesin in the expression of genes that facilitate neuronal maturation and homeostasis. Unexpectedly, we observed two major classes of activity-regulated genes with distinct reliance on cohesin in primary cortical neurons. Immediate early genes remained fully inducible by KCl and BDNF, and short-range enhancer-promoter contacts at the Immediate early geneFosformed robustly in the absence of cohesin. In contrast, cohesin was required for full expression of a subset of secondary response genes characterised by long-range chromatin contacts. Cohesin-dependence of constitutive neuronal genes with key functions in synaptic transmission and neurotransmitter signaling also scaled with chromatin loop length. Our data demonstrate that key genes required for the maturation and activation of primary cortical neurons depend cohesin for their full expression, and that the degree to which these genes rely on cohesin scales with the genomic distance traversed by their chromatin contacts.
MYC promotes immune-suppression in TNBC via inhibition of IFN signaling
Authors: Zimmerli Dario , Brambillasca Chiara S , Talens Francien , Bhin Jinhyuk , Bhattacharya Arkajyoti , Joosten Stacey E.P. , Da Silva Ana Moises , Wellenstein Max D. , Kersten Kelly , de Boo Mart , Roorda Maurits , Henneman Linda , de Bruijn Roebi , Annunziato Stefano , van der Burg Eline , Drenth Anne Paulien , Lutz Catrin , van de Ven Marieke , Wessels Lodewyk , de Visser Karin , Zwart Wilbert , Fehrmann Rudolf S.N. , van Vugt Marcel A.T.M. , Jonkers Jos
Published: February 2021

Immune checkpoint inhibitor (ICI) treatment has thus far shown limited efficacy in triple-negative breast cancer (TNBC) patients, presumably due to sparse or unresponsive tumor-infiltrating lymphocytes. We reveal a strong correlation between MYC expression and loss of immune signatures in human TNBC. In mouse models of BRCA1-proficient and -deficient TNBC, MYC overexpression dramatically decreased lymphocyte infiltration in tumors, along with immune signature loss. Likewise, MYC overexpression suppressed inflammatory signaling induced by BRCA1/2 inactivation in human TNBC cell lines. Moreover, MYC overexpression prevented the recruitment and activation of lymphocytes in co-cultures with human and mouse TNBC models. Chromatin immunoprecipitation (ChIP)-sequencing revealed that MYC directly binds promoters of multiple interferon-signaling genes, which were downregulated upon MYC expression. Finally, MYC overexpression suppressed induction of interferon signaling and tumor growth inhibition by a Stimulator of Interferon Genes (STING) agonist. Together, our data reveal that MYC suppresses innate immunity and facilitates immune escape, explaining the poor immunogenicity of MYC-overexpressing TNBCs.

Statement of Significance

MYC suppresses recruitment and activation of immune cells in TNBC by repressing the transcription of interferon genes. These findings provide a mechanistic rationale for the association of high MYC expression levels with immune exclusion in human TNBCs, which might underlie the relatively poor response of many TNBCs to ICI.
Impact of epidemics and pandemics on consumption pattern: evidence from Covid-19 pandemic in rural-urban India
Authors: Kumar Rahul , Abdin Md. Shahnawaz
Published: February 2021

Purpose

The present world is crippled with the pandemic coronavirus (Covid-19). The pandemic that originated in Wuhan city of China has sent every country in the world in an unprecedented situation that has social and economic impacts. This paper aims to explore whether epidemics and pandemics have any impact on consumption patterns among rural and urban consumers in India. Taking pandemic Covid-19 as a case study, it was explored how this pandemic impacted the consumption pattern of consumers in India; what are the similarities and/or differences between rural and urban consumers that are found in their consumption habits in the wake of Covid-19 pandemic.

Design/methodology/approach

The required data was collected through questionnaires sent to respondents. Approximately 500 respondents were contacted through the mail to fill in the survey questionnaire. Despite the sincere efforts, a total of 175 complete survey questionnaires were filled in by respondents. The study used SPSS Statistics version 25 software for the analysis of data.

Findings

It was found that epidemics and pandemics have a profound impact on the pattern of consumption in India. The study reveals that consumers resort to panic buying in the initial stages of epidemics and pandemics. It was found that consumption habits of consumers went a sea change and they were spending largely on essentials only. The study also reveals that the majority of consumers would like to continue in the same consumption habits as that of during COVID-19. The consumption pattern of urban consumers witnessed more change than the consumption pattern of rural consumers. It is due to the closure of eateries and restaurants, shopping malls, movie theatres, etc., in urban areas that forced the change in the consumption pattern of urban consumers.

Research limitations/implications

The research has a limitation of using a less sample size. For the generalizations, more robust studies can be conducted with more data.

Practical implications

The findings of the study will give marketers an insight for framing their policies in the wake of epidemics and pandemics.

Originality/value

The research adds to the existing body of knowledge. There are plenty of studies on the behaviour of consumers. However, there are no major studies that focus on the behaviour of consumers during the outbreak of a pandemic. So, this study fills this gap in the existing body of knowledge.
Application of a bottom-up approach to estimate economic impacts of building maintenance projects: cladding rectification program in Australia
Authors: Teo Pauline , Gajanayake Akvan , Jayasuriya Sajani , Izaddoost Ali , Perera Treshani , Naderpajouh Nader , Wong Peter S.P.
Published: February 2021

Purpose

This paper critically reviews economic impact assessment methods adopted in construction-related projects, to develop and present a novel bottom-up approach suitable to estimate regional economic impacts of building maintenance projects.

Design/methodology/approach

A thorough literature review of economic impact assessment in construction projects is carried out to identify the most relevant approach to estimate wider economic impacts of building maintenance projects. Based on these findings, a model based on the bottom-up approach to estimate wider economic impacts is developed. The applicability and face validity of the developed model is demonstrated through a case of cladding replacement program in Australia.

Findings

The literature review revealed that bottom-up models are better suited for estimating regional economic impacts of maintenance projects, given the challenges of obtaining micro-level economic data in the maintenance sector. In relation to the total economic impacts (direct and indirect), the results show that for every $1 of government spending on similar projects the Gross State Product would increase by $1.34. In terms of employment impact, over 70% of the direct economic value addition is driven by the increase in labour, where close to 3 FTE jobs will be required for each $1 million of spending on cladding replacement projects.

Originality/value

This paper presents a model to estimate the wider economic impacts of building maintenance projects, which is typically overlooked in the construction management field. The proposed model is developed to incorporate the variability of different building maintenance projects so that the economic impact resulting from these projects could be estimated more accurately. This model can be used by local government decision-makers to justify and prioritise maintenance projects in a similar manner to new construction projects.