bluuebunny/crossref_metadata_2025 huggingface dataset:
Galleria mellonella as a superficial model for Malassezia globosa and its treatment
Authors: Torres Maritza , Diaz-Ortiz Juliana , Davis Michael G , Schwartz James R. , Celis Ramírez Adriana Marcela
Published: April 2024

Introduction. Malassezia globosa is a yeast species that belongs to the mycobiota of humans and animals, associated with dermatological disorders such as dandruff. This is a chronic scalp skin disorder characterized by flaking and itching. Treatments include commercial shampoo with different formulations that contain antifungal activities like Zinc pyrithione or Piroctone Olamine. The effectiveness of these formulations have been evaluated for decades  for dandruff symptom relief of volunteers. To date, non-mammalian, in-vivo methods exist to test formulations of these actives.
Aim. To evaluate in vivo in Galleria mellonella larva, two commercial antifungal shampoos (Shampoo with 1% ZPT & 1.6% Zinc Carbonate and shampoo with 0.5% PO) against this species.
Methodology. G. mellonella larvae were inoculated with M. globosa on abraded cuticular surface. Then, integument cell viability, histological changes, and fungal burden were evaluated.
Results. Larvae inoculated with M. globosa showed higher lesion melanization and tissue damage. In addition, M. globosa population showed to increase over time. Concerning the shampoo’s effectiveness, both formulations significantly reduced M. globosa burden and tissue damage.
Conclusion. G. mellonella larvae were allowed to evaluate M. globosa superficial infection and antifungal effectiveness. Shampoos with ZPT and PO showed a positive effect on inoculated larvae.
Retrospective analysis of Acinetobacter baumannii bacteraemia risk factors, complications, and mortality in a tertiary university hospital in Saudi Arabia

Authors: Kaki Reham
Published: April 2024

Introduction. Acinetobacter baumannii is a nosocomial pathogen of which many isolates are multidrug resistant. A. baumannii is a major cause of healthcare-acquired infections in patients who are critically ill, and A. baumannii bacteraemia (ABB) is associated with high mortality. Several factors are known to play a role in A. baumannii transmission and the emergence of resistance.
 
Aim. This study aimed to retrospectively analyse ABB cases in Saudi Arabia, where little is known about the prevalence, risk factors, clinical disease, treatment outcomes, and mortality associated with this infection.
 
Methods. A retrospective chart review was performed from January 1, 2015, until December 31, 2022, to identify all patients 14 years and above with ABB. Demographic and clinical data, as well as results from laboratory analyses, were collected from patients’ electronic charts. Statistical analyses were performed on the data to identify factors associated with 90-day mortality.
 
Results. In total, 112 ABB cases were identified with a mean age of 58.0 years, of which 66.1% were males. Of these cases, 71 (63.4%) died. The factors that were found to be associated with 90-day mortality were the Charlson comorbidity score, Pitt bacteraemia score, quick Sequential Organ Failure Assessment (qSOFA) score (p < 0.001 for each), hospital ward (p < 0.02), short duration of antibiotic treatment (p < 0.01), and higher age (p < 0.05). The most common source of infection was Central Line-associated Bloodstream Infection in 52.7%. Also associated with mortality were inappropriate antimicrobial therapy (p < 0.02) and empirical use of colistin (p < 0.05). In many patients, ABB was caused by carbapenem-resistant A. baumannii (CRAB) (69.6%), and 74.4% of those patients died.
 
Conclusion. CRAB is a growing threat in hospitals in Saudi Arabia especially in the critical care setting and carries a very high risk of mortality. Future studies should focus on novel ways of preventing CRAB infections and on the assessment of promising new antimicrobials such as cefiderocol or sulbactam-durlobactam and other treatment options such as bacteriophages.
Effects of the Covid-19 pandemic on the continuity of sexual and reproductive health care in the maternity ward of a health and social promotion centre in Burkina Faso: a qualitative study
Authors: Ngangue Patrice , Mahamat Mariam Ahmat , Sandra Yopa Danièle , Maxime Kiki Gbètogo , Bationo Nestor , Massom Douglas Mbang , Seu Josiane , Ly Birama Apho
Published: April 2024

Background

The COVID-19 pandemic has significantly impacted the continuity of maternity care in Burkina Faso. This study aimed to compare the volumes of in-person visits and to explore the experiences of healthcare providers and users regarding the continuity of healthcare in the maternity ward of a Health and Social Promotion Center (HSPC) before, during and after the lockdown during the COVID-19 pandemic in Ouagadougou, Burkina Faso.

Methods

We conducted a multimethod, cross-sectional exploratory study with a phenomenological approach. Monthly health administrative data regarding family planning visits, antenatal visits, deliveries, and postnatal care before, during, and after COVID-19 were collected and compared. Qualitative data were collected through semi-structured interviews with family healthcare providers and users and thematically analyzed.

Results

The study found that the pandemic led to a decline in the demand for healthcare, as people were afraid of contracting COVID-19. This was particularly true for pregnant women who had recently given birth. The study also found that the pandemic disrupted the supply of essential medicines and medical supplies, which made it difficult for healthcare providers to provide quality care.

The qualitative analysis allowed us to highlight three themes: the representation of respondents on COVID-19, their perception of the effectiveness of barrier measures and their analysis of the continuity of care in times of COVID-19: the picture of respondents on COVID-19, their perception of the efficacy of barrier measures and their analysis of the continuity of care in times of COVID-19. Despite these challenges, the study found that healthcare providers and users could find ways to maintain continuity of care.

Conclusion

The study concludes that the COVID-19 pandemic has significantly impacted the continuity of maternity care in Burkina Faso. However, healthcare providers and users have found ways to maintain continuity of care, and the study provides recommendations for improving continuity of care in the future.
Exploring the barriers and enablers of oral health care utilization and safe oral sex behaviour among Transgender women of Malaysia: a qualitative study
Authors: Telang Lahari A , Rashid Abdul , Cotter Aoife G
Published: April 2024

Background

Transgender women in Malaysia are vulnerable and marginalized. They experience unique social and interpersonal challenges that contribute to relatively unmet health care needs thereby increasing their risk of acquiring HIV and sexually transmitted infections (STIs). With research pertaining to oral health of transgender women being sparse in literature, this study aimed to understand their experiences by exploring the barriers and enablers of oral health care utilization as well as safe sexual behaviour relating to oral transmission of STIs among Transgender women.

Methods

Semi structured in-depth interviews (n=20) with a group of urban dwelling transgender women (mean age= 39.8 years) in Northern Malaysia and Focus group discussion (n=7) with key informants was conducted to gain insights into the needs of the community. Participants were recruited through a snow-balling method of sampling with the help of transgender women community workers. The data obtained was coded and transcribed and subjected to thematic analysis to interpret and derive major themes and subthemes. Community advocates were involved in planning of the study.

Results

All of participants reported experiencing high levels of stigma and discrimination in daily life. Routine engagement in oral sex practices (100%, n=20) was reported with multiple partners (60%, n=12) with a perceived low level of risk of transmission of STIs through this practice (80%, n=16). Nighty percent (n=18) never used barriers or inconsistently used them during oral sexual practices. Additionally, low utilization of dental services was reported with 80% (n=16) not having visited a dentist in the past 12 months or seeking self-medication or unprofessional care. The themes that emerged from the qualitative analysis were key to understanding the experiences of the community.

Conclusion

The results identified gaps in awareness of oral transmission of STIs among the transgender women. The importance of social support in positively influencing health promotion as well as improving health care and dental care utilization was highlighted. The development of an educational intervention is proposed as an instrument to address these gaps and provide support.
Neurovascular coupling and briefCO2interrogate distinct vascular regulations
Authors: Tournissac Marine , Chaigneau Emmanuelle , Pfister Sonia , Aydin Ali-Kemal , Goulam Houssen Yannick , O’Herron Philip , Filosa Jessica , Collot Mayeul , Joutel Anne , Charpak Serge
Published: April 2024

Neurovascular coupling (NVC), which mediates rapid increases in cerebral blood flow in response to neuronal activation, is commonly used to map brain activation or dysfunction. Here we tested the reemerging hypothesis that CO2generated by neuronal metabolism contributes to NVC. We combined functional ultrasound and two-photon imaging in the mouse barrel cortex to examine specifically the onsets of local changes in vessel diameter, blood flow dynamics, vascular/perivascular/intracellular pH, and intracellular calcium signals along the vascular arbor in response to briefCO2, a short and strong hypercapnic challenge (10 s, 20%) and whisker stimulation. We report that briefCO2reversibly acidifies all cells of the arteriole wall and the periarteriolar space 3-4 seconds prior to the arteriole dilation. During this prolonged lag period, NVC triggered by whisker stimulation is not affected by the acidification of the entire neurovascular unit. As it also persists under condition of continuous inflow of CO2, we conclude that CO2is not involved in NVC.
A high-throughput and sensitive method for food preference assays in the Argentine ant
Authors: Wagner Thomas , Galante Henrique , Czaczkes Tomer J.
Published: April 2024

Insects pose significant challenges in both pest management and ecological conservation. Often, the most effective strategy is employing toxicant-laced baits, which must also be designed to specifically attract and be preferred by the targeted species for optimal species-specific effectiveness. However, traditional methods for measuring bait preference are either non-comparative, meaning that most animals only ever taste one bait, or suffer from methodological or conceptual limitations. Here we demonstrate the value of direct comparison food preference assays using the invasive and pest ant Linepithema humile (Mayr, 1868) as a model. We compare the food preference sensitivity of non-comparative (one visit to a food source) and sequential comparative (visiting one type of food then another) assays at detecting low levels of aversive quinine in sucrose solution. We then introduce and test a novel dual-choice feeder method for simultaneous comparative evaluation of bait preferences, testing its effectiveness in discerning between foods with varying quinine or sucrose levels. While the non-sequential assay could not detect aversion to 1.25mM quinine in 1M sucrose, the sequential comparative approach detected aversion to quinine levels as low as 0.94mM. The novel dual feeder method approach could detect aversion to quinine levels as low as 0.31mM, and also preference for 1M sucrose over 0.75M sucrose. The dual-feeder method combines the sensitivity of comparative evaluation with high throughput, ease of use, and avoidance of interpretational issues. This innovative approach offers a promising tool for rapid and effective testing of bait solutions, contributing to the development of targeted control strategies. The method could also be easily extended to other ant species.
Nanoparticle-mediated delivery of placental gene therapy via uterine artery catheterization in a pregnant rhesus macaque
Authors: Schmidt Jenna K. , Wilson Rebecca L. , Davenport Baylea N. , Hacker Timothy A. , Fitz Casey , Simmons Heather A. , Schotzko Michele L. , Golos Thaddeus G. , Jones Helen N.
Published: April 2024

Nanoparticles offer promise as a mechanism to non-invasively deliver targeted placental therapeutics. Our previous studies utilizing intraplacental administration demonstrate efficient nanoparticle uptake into placental trophoblast cells and overexpression of humanIGF1(hIGF1). Nanoparticle-mediated placental overexpression ofhIGF1in small animal models of placental insufficiency and fetal growth restriction improved nutrient transport and restored fetal growth. The objective of this pilot study was to extend these studies to the pregnant nonhuman primate and develop a method for local delivery of nanoparticles to the placenta via maternal blood flow from the uterine artery. Nanoparticles containinghIGF1plasmid driven by the placenta-specificPLAC1promoter were delivered to a mid-gestation pregnant rhesus macaque via a catheterization approach that is clinically used for uterine artery embolization. Maternal-fetal interface, fetal and maternal tissues were collected four days post-treatment to evaluate the efficacy ofhIGF1treatment in the placenta. The uterine artery catheterization procedure and nanoparticle treatment was well tolerated by the dam and fetus through the four-day study period following catheterization. Nanoparticles were taken up by the placenta from maternal blood as plasmid-specifichIGF1expression was detected in multiple regions of the placenta via in situ hybridization and qPCR. The uterine artery catheterization approach enabled successful delivery of nanoparticles to maternal circulation in close proximity to the placenta with no concerns to maternal or fetal health in this short-term feasibility study. In the future, this delivery approach can be used for preclinical evaluation of the long-term safety and efficacy of nanoparticle-mediated placental therapies in a rhesus macaque model.

Highlights

Novel method to deliver therapeutics to maternal-fetal interface

Delivery of nanoparticles to the placenta via maternal catheterization
Microglia drive diurnal variation in susceptibility to inflammatory blood-brain barrier breakdown
Authors: Lawrence Jennifer H. , Patel Asha , King Melvin W. , Nadarajah Collin J. , Daneman Richard , Musiek Erik S.
Published: April 2024

The blood-brain barrier (BBB) is critical for maintaining brain homeostasis but is susceptible to inflammatory dysfunction. Permeability of the BBB to lipophilic molecules shows circadian variation due to rhythmic transporter expression, while basal permeability to polar molecules is non-rhythmic. Whether daily timing influences BBB permeability in response to inflammation is unknown. Here, we induced systemic inflammation through repeated lipopolysaccharide (LPS) injections either in the morning (ZT1) or evening (ZT13) under standard lighting conditions, then examined BBB permeability to a polar molecule, sodium fluorescein. We observed clear diurnal variation in inflammatory BBB permeability, with a striking increase in paracellular leak across the BBB specifically following evening LPS injection. Evening LPS led to persisting glia activation and inflammation in the brain that was not observed in the periphery. The exaggerated evening neuroinflammation and BBB disruption were suppressed by microglial depletion or through keeping mice in constant darkness. Our data show that diurnal rhythms in microglial inflammatory responses to LPS drive daily variability in BBB breakdown and reveals time-of-day as a key regulator of inflammatory BBB disruption.
Mosaic display of stable hemagglutinin monomers induces broad immune responses
Authors: Kim Hyojin , Min Seong Cheol , Lee Dan Bi , Jeong Ju Hwan , Kim Eun Jeong , Maeng Jin Young , Seok Jong Hyeon , Lee Ji-Hye , Jang Yuyeon , Jang Ui Soon , Ysenbaert Tine , Catani João Paulo Portela , Lee JeongAh , Lee Yeongeun , Kim Youn Kyung , Lee Gyudo , Mun Ji Young , Jun Hyun Sik , Baek Yun Hee , Saelens Xavier , Lee Jiwon , Chung Mi Sook , Song Min-Suk , Kim Kyung Hyun
Published: April 2024

The nature of the interplay between immunity and viral variation is infinitely adaptive. Infection frequently induces immune responses against variation-prone epitopes, rather than against spatially hidden conserved epitopes. It thus remains a substantial challenge to elicit the immune responses to the conserved epitopes providing broad-spectrum immunity. We developed an approach of scaffold-mediated mosaic display to present monomeric influenza virus hemagglutinins (HAs), which exposes highly conserved stem and interface epitopes. Stable monomers were rationally engineered from H1 and H3 subtypes and B type HA trimers, with amino acid mutations at the monomer-monomer interface and for disulfide bond formation, and fused to a self-assembling scaffold, to generate a mosaic HA monomer-displaying nanoparticle, 3HA-np. Immunization with 3HA-np induced broadly neutralizing antibodies (bnAbs) in mice and ferrets and protected against challenges with H1N1 and H3N2 viruses. Competitive immunoassays revealed that 3HA-np induced high interface- and stem-binding Ab titers as compared to head Ab titers, indicating that the monomeric and mosaic nature of 3HA-np elicit cross-reactive Abs. Our results suggest that exposure of the hidden conserved epitope by monomer-displaying nanoparticles is a promising approach to generate a universal influenza vaccine.
Discrete photoentrainment of mammalian central clock is regulated by bi-stable dynamic network in the suprachiasmatic nucleus
Authors: Yeh Po-Ting , Jhan Kai-Chun , Chua Ern-Pei , Chen Wun-Ci , Chu Shi-Wei , Wu Shun-Chi , Chen Shih-Kuo
Published: April 2024

The circadian clock, an evolutionarily conserved mechanism regulating the majority of physiological functions in many organisms, is synchronized with the environmental light-dark cycle through circadian photoentrainment. This process is mediated by light exposure at specific times, leading to a discrete phase shift including phase delays during early subjective night, phase advances during late subjective night, and no shift at midday, known as the dead zone. In mammals, such as mice, the intrinsically photosensitive retinal ganglion cells (ipRGCs) are crucial for conveying light information to the suprachiasmatic nucleus (SCN), the central clock consisting of approximately 20,000 neurons. While the intracellular signaling pathways that modulate clock gene expression post-light exposure are well-studied, the functional neuronal circuits responsible for the three discrete light responses are not well understood. Utilizingin vivotwo-photon microscopy with gradient-index (GRIN) endoscopes, we have identified seven distinct light responses from SCN neurons. Our findings indicate that light responses from individual SCN neurons are mostly stochastic from trial to trial. However, at the population level, light response composition remains similar across trials, with only minor variations between circadian times, suggesting a dynamic populational coding for light input. Additionally, only a small subset of SCN neurons shows consistent light responses. Furthermore, by utilizing the targeted recombination in active populations (TRAP) system to label neurons that respond to light during early subjective night, we demonstrate that their activation can induce phase delays at any circadian time, effectively breaking the gate that produce photoentrainment dead zone typically observed at midday. Our results suggest the existence of at least two separate time-dependent functional circuits within the SCN. We propose a dynamic bi-stable network model for circadian photoentrainment in the mammalian central clock, where a shifting clock is driven by a dynamic functional circuit utilizing population coding to integrate information flow similar to proposed cortical computational network, rather than a simplistic, consistent linear circuit.
Lysosomal Enzyme activity: Establishing Reference Intervals from Patient Data
Authors: Mordaunt Dylan , Stark Samantha , Fietz Michael , Fletcher Janice , Metz Michael
Published: April 2024

Objectives

To develop reference intervals for leukocyte lysosomal enzymology.

Design

Standards-based establishment of reference intervals by analysis of 7851 for 17 assays of 15 lysosomal enzymes in leukocyte and plasma (January 1985 through September 2013).

Methods

Reference intervals were calculated using MedCalc for Windows version 12.5 (MedCalc Software, Ostend, Belgium), according to the Clinical and Laboratory Standards Institute C-28A protocol (CSLI-C28A).

Results and Conclusion

Evidence based reference intervals are presented in tabular form for seventeen assays of fifteen lysosomal enzymes.
SARS-CoV-2 Antigen Rapid Detection Tests: test performance during the COVID-19 pandemic and the impact of COVID-19 vaccination
Authors: Wagenhäuser Isabell , Knies Kerstin , Pscheidl Tamara , Eisenmann Michael , Flemming Sven , Petri Nils , McDonogh Miriam , Scherzad Agmal , Zeller Daniel , Gesierich Anja , Seitz Anna Katharina , Taurines Regina , Ernestus Ralf-Ingo , Forster Johannes , Weismann Dirk , Weißbrich Benedikt , Liese Johannes , Härtel Christoph , Kurzai Oliver , Dölken Lars , Gabel Alexander , Krone Manuel
Published: April 2024

Introduction

During the COVID-19 pandemic, SARS-CoV-2 antigen rapid detection tests (RDTs) emerged as point-of-care diagnostics in addition to the RT-qPCR as the gold standard for SARS-CoV-2 diagnostics. Facing the course of the COVID-19 pandemic to an endemic characterised by several SARS-CoV-2 virus variants of concern (VOC) and an increasing public COVID-19 vaccination rate the aim of the study was to investigate the long-term test performance of SARS-CoV-2 RDT in large-scale, clinical screening use during and its influencing factors, above all SARS-CoV-2 VOC and COVID-19 vaccination.

Methods

In a prospective performance assessment conducted at a single centre tertiary care hospital, RDTs from three manufacturers (NADAL®, Panbio™, MEDsan®) were compared to RT-qPCR among individuals aged ≥ 6 month. The evaluation involved the determination of standardised viral load from oropharyngeal swabs as well as the evaluation of their influencing factors, especially the COVID-19 vaccination, for detecting SARS-CoV-2 in a clinical point-of-care environment spanning from 12 November 2020 to 30 June 2023 among patients, staff, and visitors of the hospital.

Results

Among the 78,798 RDT/RT-qPCR tandems analysed, 2,016 (2.6%) tandems tested positive for SARS-CoV-2, with an overall sensitivity of 34.5% (95% CI 32.4-36.6%). A logistic regression revealed that typical COVID-19 symptoms significantly declined over the course of the study and throughout the COVID-19 pandemic, and that among the vaccinated, significantly fewer presented with an infection exhibiting typical symptoms. The employed lasso regression model indicated that only higher viral load and typical COVID-19 symptoms significantly increase the likelihood of a positive RDT result in the case of a SARS-CoV-2 infection directly.

Conclusion

Our findings indicate that only viral load and COVID-19 symptoms directly influence RDT performance while the obtained effects of COVID-19 vaccination and Omicron VOC both reducing RDT performance were mediated by these two factors. RDTs remain an adequate diagnostic tool for detecting SARS-CoV-2 in individuals showing respiratory symptoms. RDTs show promise beyond SARS-CoV-2, proving adaptable for detecting other pathogens like Influenza and RSV, highlighting their ongoing importance in infection control and prevention efforts.
MOLGENIS VIP: an open-source and modular pipeline for high-throughput and integrated DNA variant analysis
Authors: Maassen W.T.K. , Johansson L.F. , Charbon B. , Hendriksen D. , van den Hoek S. , Slofstra M.K. , Mulder R. , Meems-Veldhuis M.T. , Sietsma R. , Lemmink H.H. , van Diemen C.C. , van Gijn M.E. , Swertz M.A. , van der Velde K.J.
Published: April 2024

In silicovariant interpretation pipelines have become an integral part of genetics research and genome diagnostics. However, challenges remain for automated variant interpretation and candidate shortlisting. Their reliability is affected by variability in input data caused due the use of differing sequencing platforms, erroneous nomenclature and changing experimental conditions. Similarly, differences in predictive algorithms can result in discordant results. Finally, scalability is essential to accommodate large amounts of input data, such as in whole genome sequencing (WGS). To accelerate causal variant detection and innovation in genome diagnostics and research, we developed the MOLGENIS Variant Interpretation Pipeline (VIP). VIP is a flexible open-source computational pipeline that generates interactive reports of variants in whole exome sequencing (WES) and WGS data for expert interpretation. VIP can process short- and long-read data from different platforms and offers tools for increased sensitivity: a configurable decision-tree, filters based on human phenotype ontology (HPO) and gene inheritance that can be used to pinpoint disease-causing variants or finetune a query for specific variants. Here, alongside presenting VIP, we provide a step-by-step protocol for how to use VIP to annotate, classify and filter genetic variants of patients with a rare disease that has a suspected genetic cause. Finally, we demonstrate how VIP performs using 25,664 previously classified variants from the data sharing initiative of the Vereniging van Klinisch Genetische Laboratoriumdiagnostiek (VKGL), a cohort of 18 diagnosed patients from routine diagnostics and a cohort of 41 patients with a rare disease (RD) who were not diagnosed in routine diagnostics but were diagnosed using novel omics approaches within the EU-wide project to solve rare diseases (EU-Solve-RD). VIP requires bioinformatic knowledge to configure, but once configured, any diagnostic professional can perform an analysis within 5 hours.
Network Spreading and Local Biological Vulnerability in Amyotrophic Lateral Sclerosis
Authors: Farahani Asa , Hansen Justine , Bazinet Vincent , Shafiei Golia , Collins D. Louis , Dadar Mahsa , Karla Sanjay , Dagher Alain , Misic Bratislav
Published: April 2024

Amyotrophic Lateral Sclerosis (ALS) is a progressive neurodegenerative disease that predominantly targets the motor system. Spread of pathology is thought to be driven by both local vulnerability and network architecture. Namely, molecular and cellular features may confer vulnerability to specific neuronal populations, while synaptic contacts may also increase exposure to pathology in connected neuronal populations. However, these principles are typically studied in isolation and it remains unknown how local vulnerability and network spreading interact to shape cortical atrophy. Here we investigate how network structure and local biological features jointly shape the spatial patterning of atrophy in ALS. We analyze the Canadian ALS Neuroimaging Consortium (CALSNIC) dataset and estimate cortical atrophy using deformation-based morphometry (DBM). We find that structural connectivity closely aligns with the course of atrophy. Atrophy is also more likely to occur in regions that share similar transcriptomic, neurotransmitter receptor and metabolic profiles. We identify disease epicenters in motor cortex. Epicenter probability maps show transcriptomic enrichment for biological pathways involved in mitochondrial function as well as support cells, including endothelial cells and pericytes. Finally, individual differences in epicenter location correspond to individual differences in clinical and cognitive symptoms, and differentiate patient subtypes.
Structural and Dynamic Insights into the Biased Signaling Mechanism of the Human Kappa Opioid Receptor
Authors: Suno-Ikeda Chiyo , Nishikawa Ryo , Suzuki Riko , Iwata Seiya , Takai Tomoyo , Ogura Takaya , Hirose Mika , Inoue Akitoshi , Asai Eri , Kise Ryoji , Sugita Yukihiko , Kato Takayuki , Nagase Hiroshi , Saitoh Tsuyoshi , Katayama Kota , Inoue Asuka , Kandori Hideki , Kobayashi Takuya , Suno Ryoji
Published: April 2024

The κ-opioid receptor (KOR) is a member of the G protein-coupled receptor (GPCR) family, responsible for modulating cellular responses through transducers such as G proteins and arrestins. G protein-biased KOR agonists hold promise due to their potential to mitigate side effects such as drug aversion and sedation while preserving analgesic and antipruritic effects. Here, we shed light on the structural dynamics of the human KOR-Gisignaling complex bound with either nalfurafine (a G-protein-biased agonist) or U-50,488H (a balanced agonist) using cryo-electron microscopy (cryo-EM). Cryo-EM structures of the KOR-Gisignaling complexes identify the ligand binding mode in the activated state. Vibrational spectroscopy analysis reveals changes in the ligand-binding pocket upon binding to these ligands. Cell-based mutant experiments pinpoint four amino acids (K2275.40, C2866.47, H2916.52, and Y3127.34; Ballesteros–Weinstein numbering is shown in superscript) that play crucial roles in arrestin recruitment. Among these four amino acids, H2916.52and Y3127.34are also implicated in G-protein coupling. Our findings pave the way for targeting specific residues in the KOR ligand-binding pocket to enhance KOR-mediated therapeutic effects while mitigating unwanted side effects.
Orbitofrontal cortex to dorsal striatum circuit is critical for incubation of oxycodone craving after forced abstinence
Authors: Lin Hongyu , Olaniran Adedayo , Luo Xiang , Strauch Jessica , Burke Megan AM , Matheson Chloe L. , Li Xuan
Published: April 2024

Relapse is a major challenge in treating opioid addiction, including oxycodone. During abstinence, oxycodone seeking progressively increases, and we previously demonstrated a causal role of the orbitofrontal cortex (OFC) in this incubation of oxycodone craving after forced abstinence. Here, we explored critical downstream targets of OFC by focusing on dorsal striatum (DS). We first examined dorsal striatal Fos (a neuronal activity marker) expression associated with oxycodone seeking after abstinence. Using a dopamine D1 receptor (D1R) antagonist, we also tested the causal role of DS in incubated oxycodone seeking. Next, we combined fluorescence-conjugated cholera toxin subunit B (CTb-555, a retrograde tracer) with Fos to assess whether the activation of OFC→DS projections was associated with incubated oxycodone seeking. We then used a series of pharmacological procedures to examine the causal role of the interaction between glutamatergic projections from OFC and D1R signaling in DS in incubation of oxycodone craving. We found that dorsal striatal Fos expression in DS exhibited a time-dependent increase in parallel with incubation of oxycodone craving, and DS inactivation decreased incubated oxycodone seeking. Moreover, OFC→DS projections were activated during incubated oxycodone seeking, and anatomical disconnection of OFC→DS projections, but not unilateral inactivation of OFC or DS, decreased incubated oxycodone seeking. Lastly, contralateral disconnection of OFC→DS projections had no effect on oxycodone seeking on abstinence day 1. Together, these results demonstrated a causal role of OFC→DS projections in incubation of oxycodone craving.
Overcoming the preferred orientation problem in cryoEM with self-supervised deep-learning
Authors: Liu Yun-Tao , Fan Hongcheng , Hu Jason J. , Zhou Z. Hong
Published: April 2024

While advances in single-particle cryoEM have enabled the structural determination of macromolecular complexes at atomic resolution, particle orientation bias (the so-called “preferred” orientation problem) remains a complication for most specimens. Existing solutions have relied on biochemical and physical strategies applied to the specimen and are often complex and challenging. Here, we develop spIsoNet, an end-to-end self-supervised deep-learning-based software to address the preferred orientation problem. Using preferred-orientation views to recover molecular information in under-sampled views, spIsoNet improves both angular isotropy and particle alignment accuracy during 3D reconstruction. We demonstrate spIsoNet’s capability of generating near-isotropic reconstructions from representative biological systems with limited views, including ribosomes, β-galactosidases, and a previously intractable hemagglutinin trimer dataset. spIsoNet can also be generalized to improve map isotropy and particle alignment of preferentially oriented molecules in subtomogram averaging. Therefore, without additional specimen-preparation procedures, spIsoNet provides a general computational solution to the preferred orientation problem.
Modeling cardiac microcirculation for the simulation of coronary flow and 3D myocardial perfusion
Authors: Montino Pelagi Giovanni , Regazzoni Francesco , Huyghe Jacques M. , Baggiano Andrea , Alì Marco , Bertoluzza Silvia , Valbusa Giovanni , Pontone Gianluca , Vergara Christian
Published: April 2024

Purpose

accurate modeling of blood dynamics in the coronary microcirculation is a crucial step towards the clinical application ofin silicomethods for the diagnosis of coronary artery disease (CAD). In this work, we present a new mathematical model of microcirculatory hemodynamics accounting for microvasculature compliance and cardiac contraction; we also present its application to a full simulation of hyperemic coronary blood flow and 3D myocardial perfusion in real clinical cases.

Methods

microvasculature hemodynamics is modeled with acompliantmulti-compartment Darcy formulation, with the new compliance terms depending on the local intramyocardial pressure generated by cardiac contraction. Nonlinear analytical relationships for vessels distensibility are included based on experimental data, and all the parameters of the model are reformulated based on histologically relevant quantities, allowing a deeper model personalization.

Results

Phasic flow patterns of high arterial inflow in diastole and venous outflow in systole are obtained, with flow waveforms morphology and pressure distribution along the microcirculation reproduced in accordance with experimental andin vivomeasures. Phasic diameter change for arterioles and capillaries is also obtained with relevant differences depending on the depth location. Coronary blood dynamics exhibits a disturbed flow at the systolic onset, while the obtained 3D perfusion maps reproduce the systolic impediment effect and show relevant regional and transmural heterogeneities in myocardial blood flow (MBF).

Conclusion

the proposed model successfully reproduces microvasculature hemodynamics over the whole heartbeat and along the entire intramural vessels. Quantification of phasic flow patterns, diameter changes, regional and transmural heterogeneities in MBF represent key steps ahead in the direction of the predictive simulation of cardiac perfusion.
“Poly (A) Binding Protein 2 is critical for stem-progenitor differentiation during regeneration in the planarianSchmidtea mediterranea.”
Authors: Mukundan Namita , Hariharan Nivedita , Sasidharan Vidyanand , Lakshmanan Vairavan , Palakodeti Dasaradhi , Jamora Colin
Published: April 2024

Post-transcriptional regulation has emerged as a key mechanism to regulate stem cell renewal and differentiation, which is essential for understanding tissue regeneration and homeostasis. Poly(A)-binding proteins are a family of RNA-binding proteins that play a vital role in post-transcriptional regulation by controlling mRNA stability and protein synthesis. The involvement of poly(A) binding proteins in a wide range of cellular functions is increasingly being investigated. In this study, we used the regenerative model organism planarianSchmidtea mediterranea, to demonstrate the critical role of poly(A)-binding protein 2 (PABP2) in regulating neoblast maintenance and differentiation. A deficit in PABP2 blocks the transition of neoblasts towards immediate early progenitors, leading to an enhanced pool of non-committed neoblasts and a decreased progenitor population. This is reflected in variations in the transcriptome profile, providing evidence of downregulation in multiple lineages. Thus, insufficiency of PABP2 resulted in defective formation and organization of tissue leading to abnormal regeneration. Our study reveals the essential role of PABP2 in regulating genes that mediate stem cell commitment to early progenitors during tissue regeneration.
The neonicotinoid acetamiprid is highly toxic to wild non-target insects
Authors: Sedlmeier Jan Erik , Grass Ingo , Bendalam Prasanth , Höglinger Birgit , Walker Frank , Gerhard Daniel , Piepho Hans-Peter , Brühl Carsten A. , Petschenka Georg
Published: April 2024

Although pesticides are seen as one of the main drivers of insect decline, there are still only few studies that assess their effects on non-target species under field conditions. Here we investigated the effects of the neonicotinoid insecticide Mospilan®SG (active ingredient acetamiprid) on plant bugs (Heteroptera: Miridae), a dominant group of European grassland insect communities. Abundance of three focal mirid species was reduced by up to 78% two days after field exposure at concentrations expected at field margins, with mortality varying considerably among species. Follow-up feeding assays with insecticide-treated host plants in the greenhouse and controlled dose-response assays in the laboratory confirmed the strong negative effects on non-target species. Strikingly, the neonicotinoid was nearly 10,000 times more toxic to plant bugs than to honeybees. In addition, male bugs were 20 times more sensitive than females in two of the three tested species. Thus, continuous exposure to neonicotinoids in the field may reduce the plant bug populations and promote a shift towards more insecticide-tolerant species, altering community composition. We suggest that sex-specific sensitivity should be considered in risk assessment and conclude that the real risk to non-target insects is currently greatly underestimated.
TheC. elegansuv1 neuroendocrine cells provide direct mechanosensory feedback of vulval opening
Authors: Yan Lijie , Claman Alexander , Bode Addys , Collins Kevin M.
Published: April 2024

Neuroendocrine cells react to physical, chemical, and synaptic signals originating from tissues and the nervous system, releasing hormones that regulate various body functions beyond the synapse. Neuroendocrine cells are often embedded in complex tissues making direct tests of their activation mechanisms and signaling effects difficult to study. In the nematode wormC. elegans, four uterine-vulval (uv1) neuroendocrine cells sit above the vulval canal next to the egg-laying circuit, releasing tyramine and neuropeptides that feedback to inhibit egg laying. We have previously shown uv1 cells are mechanically deformed during egg laying, driving uv1 Ca2+transients. However, whether egg-laying circuit activity, vulval opening, and/or egg release triggered uv1 Ca2+activity was unclear. Here we show uv1 responds directly to mechanical activation. Optogenetic vulval muscle stimulation triggers uv1 Ca2+activity following muscle contraction even in sterile animals. Direct mechanical prodding with a glass probe placed against the worm cuticle triggers robust uv1 Ca2+activity similar to that seen during egg laying. Direct mechanical activation of uv1 cells does not require other cells in the egg-laying circuit, synaptic or peptidergic neurotransmission, or TRPV and Piezo channels. EGL-19 L-type Ca2+channels, but not P/Q/N-type or Ryanodine Receptor Ca2+channels, promote uv1 Ca2+activity following mechanical activation. L-type channels also facilitate the coordinated activation of uv1 cells across the vulva, suggesting mechanical stimulation of one uv1 cells cross-activates the other. Our findings show how neuroendocrine cells like uv1 report on the mechanics of tissue deformation and muscle contraction, facilitating feedback to local circuits to coordinate behavior.

Significance Statement

Neuroendocrine cells respond to diverse physical and chemical signals from the body, releasing hormones that control reproduction, gut motility, and fight or flight responses. Neuroendocrine cells are often found embedded in complex tissues, complicating studies of how they are activated. Using the genetic and experimental accessibility ofC. elegans, we find the uv1 neuroendocrine cells of the egg-laying motor behavior circuit respond directly to mechanical stimulation and vulval opening. We show that L-type voltage-gated Ca2+channels facilitate uv1 mechanical activation and also coordinate cell activation across the vulval opening. In contrast to other mechanically activated cells, uv1 activation does not require Piezo or TRPV channels. This work shows how neuroendocrine cells relay critical mechanosensory feedback to circuits that control reproduction.
Regulation of lung cancer initiation and progression by the stem cell determinant Musashi
Authors: Barber Alison G , Quintero Cynthia M , Hamilton Michael , Rajbhandari Nirakar , Sasik Roman , Zhang Yan , Kim Carla , Husain Hatim , Sun Xin , Reya Tannishtha
Published: April 2024

Despite advances in therapeutic approaches, lung cancer remains the leading cause of cancer-related deaths. To understand the molecular programs underlying lung cancer initiation and maintenance, we focused on stem cell programs that are normally extinguished with differentiation but can be reactivated during oncogenesis. Here we have used extensive genetic modeling and patient-derived xenografts to identify a dual role for Msi2: as a signal that acts initially to sensitize cells to transformation, and subsequently to drive tumor propagation. Using Msi reporter mice, we found that Msi2-expressing cells were marked by a pro-oncogenic landscape and a preferential ability to respond to Ras and p53 mutations. Consistent with this, genetic deletion of Msi2 in an autochthonous Ras/p53-driven lung cancer model resulted in a marked reduction of tumor burden, delayed progression, and a doubling of median survival. Additionally, this dependency was conserved in human disease as inhibition of Msi2 impaired tumor growth in patient-derived xenografts. Mechanistically, Msi2 triggered a broad range of pathways critical for tumor growth, including several novel effectors of lung adenocarcinoma. Collectively, these findings reveal a critical role for Msi2 in aggressive lung adenocarcinoma, lend new insight into the biology of this disease, and identify potential new therapeutic targets.
Classifying native versus foreign speech perception from EEG using linguistic speech features
Authors: Puffay Corentin , Vanthornhout Jonas , Gillis Marlies , De Clercq Pieter , Accou Bernd , Van hamme Hugo , Francart Tom
Published: April 2024

When a person listens to natural speech, the relation between features of the speech signal and the corresponding evoked electroencephalogram (EEG) is indicative of neural processing of the speech signal. Using linguistic representations of speech, we investigate the differences in neural processing between speech in a native and foreign language that is not understood. We conducted experiments using three stimuli: a comprehensible language, an incomprehensible language, and randomly shuffled words from a comprehensible language, while recording the EEG signal of native Dutch-speaking participants. We modeled the neural tracking of linguistic features of the speech signals using a deep-learning model in a match-mismatch task that relates EEG signals to speech, while accounting for lexical segmentation features reflecting acoustic processing. The deep learning model effectively classifies languages. We also observed significant differences in tracking patterns between comprehensible and incomprehensible speech stimuli within the same language. It demonstrates the potential of deep learning frameworks in measuring speech understanding objectively.
An effector XopL enhances ethylene biosynthesis to promoteXanthomonas fragariaeinfection in strawberry
Authors: Cai Xiaolin , Zhang Wenyao , Luo Jinnan , Li Wei , Chen Rui-hong , Xu Xiang-nan , Wen Ying-qiang , Feng Jia-yue
Published: April 2024

Xanthomonas fragariae(Xaf) is the cause for strawberry crown dry cavity rot and strawberry leaf angular spots. Despite having a long evolutionary history with strawberries, the plant-pathogen connection is poorly understood. Pathogenicity for the majority of plant pathogens is mostly dependent on the type-III secretion system, which introduces virulence type III effectors (T3Es) into eukaryotic hosts cells. For most of these T3Es, the subcellular targets are yet unclear. Here, We used the yeast-two-hybrid (Y2H) technique to construct an interaction network of strawberry-XafT3Es. Multiple T3Es were discovered to converge onto the strawberry 1-aminocyclopropane-1-carboxylic acid oxidases (ACOs), which are the last rate-limited step in the production of ethylene. We then concentrated on the connection between XopL and FveACO9. Strawberry plants that overexpressed XopL accumulated higher levels of ethylene and exhibited more severeXafinfection. XopL boosted ethylene production by stabilizing the accumulation of FveACO9 protein and enhancing ACO enzyme activity. Additionally, strawberries treated with ACC or overexpressing FveACO9 were particularly vulnerable toXafinfection. On the other hand, pre-treatment with α-aminoinoisobutyric acid (AIB), an ACO inhibitor, effectively reducedXafinfection. Our research indicates thatXafutilizes a distinct approach to regulate the ethylene production of host plants in order to promote infection.
PAK6 rescues pathogenic LRRK2-mediated ciliogenesis and centrosomal cohesion defects in a mutation-specific manner
Authors: Iannotta Lucia , Fasiczka Rachel , Favetta Giulia , Zhao Yibo , Giusto Elena , Dall'Ara Elena , Wei Jianning , Ho Franz , Ciriani Claudia , Cogo Susanna , Tessari Isabella , Iaccarino Ciro , Liberelle Maxime , Bubacco Luigi , Taymans Jean-Marc , Manzoni Claudia , Kortholt Arjan , Civiero Laura , Hilfiker Sabine , Lu Michael , Greggio Elisa
Published: April 2024

P21 activated kinase 6 (PAK6) is a serine-threonine kinase with physiological expression enriched in the brain and overexpressed in a number of human tumors. While the role of PAK6 in cancer cells has been extensively investigated, the physiological function of the kinase in the context of brain cells is poorly understood. Our previous work uncovered a link between PAK6 and the Parkinson's disease (PD)-associated kinase LRRK2, with PAK6 controlling LRRK2 activity and subcellular localization via phosphorylation of 14-3-3 proteins. Here, to gain more insights into PAK6 physiological function, we performed protein-protein interaction arrays and identified a subgroup of PAK6 binders related to ciliogenesis. We confirmed that endogenous PAK6 localizes at both the centrosome and the cilium, and positively regulates ciliogenesis not only in tumor cells but also in neurons and astrocytes. Strikingly, PAK6 rescues ciliogenesis and centrosomal cohesion defects associated with the G2019S but not the R1441C LRRK2 PD mutation. Since PAK6 binds LRRK2 via its GTPase/Roc-COR domain and the R1441C mutation is located in the Roc domain, we used microscale thermophoresis and AlphaFold2-based computational analysis to demonstrate that PD mutations in LRRK2 affecting the Roc-COR structure substantially decrease PAK6 affinity, providing a rationale for the differential protective effect of PAK6 toward the distinct forms of mutant LRRK2. Altogether, our study discloses a novel role of PAK6 in ciliogenesis and points to PAK6 as the first LRRK2 modifier with PD mutation-specificity.