bluuebunny/crossref_metadata_2025 huggingface dataset:
State-dependent alteration of respiration in a rat model of Parkinson disease
Authors: Walker Jean Jacques , Meunier Estelle , Garcia Samuel , Messaoudi Belkacem , Mouly Anne-Marie , Veyrac Alexandra , Buonviso Nathalie , Courtiol Emmanuelle
Published: November 2023

Parkinson disease (PD) is the second most frequent neurodegenerative disorder. Besides major deficits in motor coordination, patients may also display sensory and cognitive impairments, which are often overlooked despite being inherently part of the PD symptomatology. Amongst those symptoms, respiration, a key mechanism involved in the regulation of multiple physiological and neuronal processes, appears to be altered. Importantly, breathing patterns are highly correlated with the animal’s behavioral states, and although respiration has been investigated in different models of PD, no study has yet taken into consideration the potential impact of behavioral state on respiration deficits in these models. To explore this variable, we first characterized the respiratory parameters in a neurotoxin-induced rat model of PD (6-OHDA) across different vigilance states: sleep, quiet waking and exploration. We noted a significantly higher respiratory frequency in 6-OHDA rats during quiet waking compared to Sham rats. A higher respiratory amplitude was also observed in 6-OHDA rats during both quiet waking and exploration. No effect of the treatment was noted during sleep. Given the relation between respiration and olfaction and the presence of olfactory deficits in PD patients, we then investigated the odor-evoked sniffing response in PD rats, using an odor habituation/cross-habituation paradigm. No substantial differences were observed in olfactory abilities between the two groups, as assessed through sniffing frequency. These results corroborate the hypothesis that respiratory impairments in 6-OHDA rats are vigilance-dependent. Our results also shed light on the importance of considering the behavioral state as an impacting factor when analyzing respiration.

Highlights

Specific respiratory patterns associated to different vigilance states

Specific alteration of respiration during quiet waking in a rodent model of PD

Preserved olfactory abilities as assessed through sniffing in a rodent model of PD
Trinucleotide mRNA cap analog N6-benzylated at the site of posttranscriptionalm6Am mark facilitates mRNA purification and confers superior translational properties in vitro and in vivo
Authors: Warminski Marcin , Trepkowska Edyta , Smietanski Miroslaw , Sikorski Pawel J. , Baranowski Marek R. , Bednarczyk Marcelina , Kedzierska Hanna , Majewski Bartosz , Mamot Adam , Papiernik Diana , Popielec Agnieszka , Serwa Remigiusz A. , Shimanski Brittany A. , Sklepkiewicz Piotr , Sklucka Marta , Sokolowska Olga , Spiewla Tomasz , Toczydlowska-Socha Diana , Warminska Zofia , Wolosewicz Karol , Zuberek Joanna , Mugridge Jeffrey S. , Nowis Dominika , Golab Jakub , Jemielity Jacek , Kowalska Joanna
Published: November 2023

Eukaryotic mRNAs undergo co-transcriptional 5’-end modification with a 7-methylguanosine cap. In higher eukaryotes, the cap carries additional methylations, such asm6Am– a common epitranscriptomic mark unique to the mRNA 5’-end. This modification is regulated by the Pcif1 methyltransferase and the FTO demethylase, but its biological function is still unknown. Here, we designed and synthesized a trinucleotide FTO-resistantN6-benzyl analog of them6Am-cap – m7GpppBn6AmpG (termedAvantCap) and incorporated it into mRNA using T7 polymerase. mRNAs carryingBn6Amshowed several advantages over typical capped transcripts. TheBn6Ammoiety was shown to act as an RP-HPLC purification handle, allowing separation of capped and uncapped RNA species, and to produce transcripts with lower dsRNA content than reference caps. In some cultured cells,Bn6AmmRNAs provided higher protein yields than mRNAs carrying Amorm6Am, although the effect was cell line-dependent. m7GpppBn6AmpG-capped mRNAs encoding reporter proteins administered intravenously to mice provided up to 6-fold higher protein outputs than reference mRNAs, while mRNAs encoding tumor antigens showed superior activity in therapeutic setting as anti-cancer vaccines. The biochemical characterization suggests several phenomena underlying the biological properties ofAvantCap: (i) increased competitiveness of the mRNA 5’-end for eIF4E protein by reducing its propensity for unspecific interactions, (ii) direct involvement of eIF3 in alternative translation initiation, (iii) subtle differences in mRNA impurity profiles, or a combination of these effects.AvantCapped-mRNAs bearing theBn6Ammay pave the way for more potent mRNA-based vaccines and therapeutics and serve as molecular tools to unravel the role of them6Amin mRNA.
Dynamics of odor-source localization: Insights from real-time odor plume recordings and head-motion tracking in freely moving mice
Authors: Tariq Mohammad F. , Sterrett Scott C. , Moore Sidney , Lane  , Perkel David J. , Gire David H.
Published: November 2023

Animals navigating turbulent odor plumes exhibit a rich variety of behaviors, and employ efficient strategies to locate odor sources. A growing body of literature has started to probe this complex task of localizing airborne odor sources in walking mammals to further our understanding of neural encoding and decoding of naturalistic sensory stimuli. However, correlating the intermittent olfactory information with behavior has remained a long-standing challenge due to the stochastic nature of the odor stimulus. We recently reported a method to record real-time olfactory information available to freely moving mice during odor-guided navigation, hence overcoming that challenge. Here we combine our odor-recording method with head-motion tracking to establish correlations between plume encounters and head movements. We show that mice exhibit robust head-pitch motions in the 5-14Hz range during an odor-guided navigation task, and that these head motions are modulated by plume encounters. Furthermore, mice reduce their angles with respect to the source upon plume contact. Head motions may thus be an important part of the sensorimotor behavioral repertoire during naturalistic odor-source localization.
Continuity of Mitochondrial Budding: Insights from BS-C-1 Cells byin-situCryo-Electron Tomography
Authors: Hu Judy Z , Qiao Lijun , Zhao Xianhai , Liu Chang-Jun , Hu Guo-Bin
Published: November 2023

Mitochondrial division is a fundamental biological process that is crucial to cellular functionality and vitality. The prevailing hypothesis of Drp1 regulation with the involvement of ER and cytoskeleton does not account for all the observations. Following up our previous study in HeLa cells which led to the new hypothesis of mitochondrial division by budding, we employedin-situCryo-Electron Tomography (Cryo-ET) to visualize mitochondrial budding in intact healthy monkey kidney cells (BS-C-1 cells). Our findings reaffirm single and multiple mitochondrial budding, supporting the new hypothesis. Notably, the budding regions vary significantly in diameter and length, which may represent different stages of budding. More interestingly, no rings, or ring-like structures, or ER wrapping is presented in the budding regions suggesting mitochondrial budding is independent from Drp1 and ER. Meanwhile, we uncovered direct interactions between mitochondria and large vesicles, distinct from small mitochondrial-derived vesicles and extracellular mitovesicles. We propose these interacting vesicles may have mitochondrial origins.
Activation of glucocorticoid receptor signaling inhibits KSHV-induced inflammation and tumorigenesis
Authors: Chen Luping , Ding Ling , Wang Xian , Huang Yufei , Gao Shou-Jiang
Published: November 2023

Hyperinflammation is the hallmark of Kaposi’s sarcoma (KS), the most common cancer in AIDS patients caused by Kaposi’s sarcoma-associated herpesvirus (KSHV) infection. However, the role and mechanism of induction of inflammation in KS remain unclear. In a screening for inhibitors of KSHV-induced oncogenesis, over half of the identified candidates were anti-inflammatory agents including dexamethasone functions by activating glucocorticoid receptor (GR) signaling. Here, we examined the mechanism mediating KSHV-induced inflammation. We found that numerous inflammatory pathways were activated in KSHV-transformed cells. Particularly, interleukin-1 alpha (IL-1α) and IL-1 receptor antagonist (IL-1Ra) from the IL-1 family were the most induced and suppressed cytokines, respectively. We found that KSHV miRNAs mediated IL-1α induction while both miRNAs and vFLIP mediated IL-1Ra suppression. Furthermore, GR signaling was inhibited in KSHV-transformed cells, which was mediated by vFLIP and vCyclin. Dexamethasone treatment activated GR signaling, and inhibited cell proliferation and colony formation in soft agar of KSHV-transformed cells but had a minimal effect on matched primary cells. Consequently, dexamethasone suppressed the initiation and growth of KSHV-induced tumors in mice. Mechanistically, dexamethasone suppressed IL-1α but induced IL-1Ra expression. Treatment with recombinant IL-1α protein rescued the inhibitory effect of dexamethasone while overexpression of IL-1Ra caused a weak growth inhibition of KSHV-transformed cells. Furthermore, dexamethasone induced IκBα expression resulting in inhibition of NF-κB pathway and IL-1α expression. These results reveal an important role of IL-1 pathway in KSHV-induced inflammation and oncogenesis, which can be inhibited by dexamethasone-activated GR signaling, and identify IL-1-mediated inflammation as a potential therapeutic target for KSHV-induced malignancies.

Importance

Kaposi’s sarcoma (KS) is the most common cancer in HIV-infected patients caused by Kaposi’s sarcoma-associated herpesvirus (KSHV) infection. Hyperinflammation is the hallmark of KS. In this study, we have shown that KSHV mediates hyperinflammation by inducing IL-1α and suppressing IL-1Ra. Mechanistically, KSHV miRNAs and vFLIP induce hyperinflammation by activating the NF-κB pathway. A common anti-inflammatory agent dexamethasone blocks KSHV-induced hyperinflammation and tumorigenesis by activating glucocorticoid receptor signaling to suppress IL-1α and induce IL-1Ra. This work has identified IL-1-mediated inflammation as a potential therapeutic target and dexamethasone as a potential therapeutic agent for KSHV-induced malignancies.
A mathematical model of whole-body potassium regulation: Global parameter sensitivity analysis*
Authors: Stadt Melissa M. , Layton Anita T.
Published: November 2023

Potassium (K+) is an essential electrolyte that is tightly regulated by various complex physiological mechanisms. In this study, we analyze a mathematical model of whole-body K+regulation to investigate the sensitivity of different model outcomes to parameter values. We used the Morris method, a global sensitivity analysis technique, to evaluate the impact of the parameters on both steady state results and transient simulations during a single-meal. Our results shows that the most influential parameters and processes depend on what you are measuring. Specifically, steady state results relied primarily on parameters that were involved in kidney function, while transient results relied on hormonal feedback mechanisms. This study shows that our mathematical model of whole-body potassium regulation captures known physiological function of potassium regulation despite a large number of uncertain parameters.

MSC codes

68Q25, 68R10, 68U05
Understanding the bacterial imbalance in Hidradenitis Suppurativa patients: Insights into microbial community shifts and colonization by opportunistic pathogens
Authors: Bens Lene , Vanhoutvin Tine , Kerremans Alison , Jansen Daan , Depypere Melissa , Hillary Tom , Vermeire Séverine , Green Sabrina I. , Matthijnssens Jelle , Sabino João , Lavigne Rob , Laethem An Van , Wagemans Jeroen
Published: November 2023

Patients suffering from hidradenitis suppurativa (HS) develop painful skin lesions, significantly decreasing their quality of life. This chronic disease is triggered by plugged hair follicles resulting in an aberrant immune response, skin microbiome imbalance and secondary bacterial colonization. As a result, a diversity of treatment options are currently applied, including antibiotics, biologicals like adalimumab and surgery, which often provide only short-term relief. Alternative strategies, like phage therapy, have been proposed but identification of the target bacterium is key. Therefore, a spatial and longitudinal analysis was performed on skin swabs of lesions from 39 HS patients and 18 healthy controls, leading to a total collection of 108 lesional samples and 35 control samples at different time points and locations throughout the body. Samples were subjected to 16S rRNA community analysis, as well as bacterial isolation using aerobic and anaerobic culturing in combination with MALDI-TOF. Our data demonstrate that the bacterial community present in lesions of patients with HS is out of balance compared to healthy individuals, in which the niche ofStaphylococcusandCorynebacteriumis taken over byEscherichia-Shigella. Overall, three bacterial community profiles of HS lesions and one of healthy individuals could be distinguished. Although the overall bacterial composition was not associated with the disease severity defined by the Hurley classification system, lesions often become colonized with opportunistic pathogens includingStaphylococcus aureusandPseudomonas aeruginosaat increasing disease severities. Furthermore, patients with a concurrent IBD diagnosis did not reveal a significantly different bacterial skin community.
Efficient genome editing using modified Cas9 proteins in zebrafish
Authors: Dorner Laura , Stratmann Benedikt , Bader Laura , Podobnik Marco , Irion Uwe
Published: November 2023

The zebrafish (Danio rerio) is an important model organism for basic as well as applied bio-medical research. One main advantage is its genetic tractability, which was greatly enhanced by the introduction of the CRISPR/Cas method a decade ago. The generation of loss-of-function alleles via the production of small insertions or deletions in the coding sequences of genes with CRISPR/Cas systems is now routinely achieved with high efficiency. The method is based on the error prone repair of precisely targeted DNA double strand breaks by non-homologous end joining (NHEJ) in the cell nucleus. However, editing the genome with base pair precision, by homology-directed repair (HDR), is by far less efficient and therefore often requires large-scale screening of potential carriers by labour intensive genotyping. Here we show that the Cas9 protein variant SpRY with relaxed PAM requirement can be used for gene targeting in zebrafish, thus expanding the versatility of the method. In addition, we demonstrate that the incorporation of an artificial nuclear localisation signal (aNLS) into the Cas9 protein variants not only enhances the efficiency of gene knock-out but also the frequency of HDR thereby facilitating the efficient modification of single base pairs in the genome. Our protocols provide a guide for a cost-effective generation of versatile and potent Cas9 protein variants and efficient gene editing in zebrafish.
Perturbed sulfur homeostasis allowsC. elegansto escape growth retardation onActinobacteriafrom its natural microbiome
Authors: Patange Om , Breen Peter , Ruvkun Gary
Published: November 2023

The rate at which organisms grow is influenced by their biotic environment. The nematodeCaenorhabditis elegansgrows slower in the presence ofActinobacteria, but it is unknown why. Here, we show how perturbed levels of hydrogen sulfide and cysteine modulate the growth rate ofC. elegansonActinobacteria. Using an unbiased forward genetic screen ofC. eleganswe discovered alleles of the conserved cystathionine gamma-lyase (cth-2/CTH)that improved animal growth rate onActinobacteria. Conversely, null alleles ofcth-2cause developmental arrest of animals grown onActinobacteria, which can be rescued by exogenous H2S. We also discovered a leucine rich repeat gene that regulates cysteine and H2S production,lrr-2/LRRC58.A wild isolate ofC. elegansthat naturally grows well onActinobacteriahas a mutant allele oflrr-2, suggesting this sulfur metabolism pathway is important for the regulation of animal growth rate in its natural ecological context. We propose a model in which wild-type worms use sulfurous compounds to promote growth of their favored bacterial food sources by inhibitingActinobacteriagrowth. This strategy becomes a liability whenActinobacteriaare the sole food source but can be bypassed by mutations in sulfur metabolism. This study reveals how the homeostasis of sulfurous compounds controls the growth rate of animals in an ecological context.
A comparative medical genomics approach may facilitate the interpretation of rare missense variation
Authors: Haque Bushra , Guirguis George , Curtis Meredith , Mohsin Hera , Walker Susan , Morrow Michelle M. , Costain Gregory
Published: November 2023

Purpose

To determine the degree to which likely causal missense variants of single-locus traits in non-human livestock and domestic species have features suggestive of pathogenicity in a human genomic context.

Methods

We extracted missense variants from the Online Mendelian Inheritance in Animals database for nine animals (cat, cattle, chicken, dog, goat, horse, pig, rabbit, sheep), mapped coordinates to the human reference genome, and annotated variants using genome analysis tools. We also searched a private commercial laboratory database of genetic testing results from >400,000 individuals with suspected rare disorders.

Results

Of 339 variants that were mappable to the same residue and gene in the human genome, 56 had been previously classified with respect to pathogenicity: 31 (55.4%) pathogenic/likely pathogenic, 1 (1.8%) benign/likely benign, and 24 (42.9%) uncertain/other. The odds ratio for a pathogenic/likely pathogenic classification in ClinVar was 7.0 (95% confidence interval: 4.1-12.0, p<0.0001), compared to all other germline missense variants in these same 220 genes. The remaining 283 variants disproportionately had allele frequencies and REVEL scores that supported pathogenicity.

Conclusion

Cross-species comparisons could facilitate the interpretation of rare missense variation. These results provide further support for comparative medical genomics approaches that connect big data initiatives in human and veterinary genetics.
Lymphocyte profiles after a first demyelinating event suggestive of multiple sclerosis reveal early monocyte and B cell alterations
Authors: Alvarez-Gonzalez Cesar , Wiedemann Annika , Schroeder-Castagno Maria , Schepanski Steven , Asseyer Susanna , Chien Claudia , Kuchling Joseph , Bellmann-Strobl Judith , Ruprecht Klemens , Infante-Duarte Carmen , Dörner Thomas , Paul Friedemann
Published: November 2023

Introduction

Often, an isolated clinical event suggestive of CNS demyelination confers a risk of conversion to multiple sclerosis. In this study, we investigate lymphocyte profiles after a first clinical event suggestive of multiple sclerosis (MS), which could contribute to the current understanding of early inflammatory responses in this demyelinating disease.

Methods

Twenty treatment-naïve clinically isolated syndrome (CIS) patients and fifteen healthy participants were included in our assessment of lymphocyte profiles and B cell subsets using multicolour flow cytometry. Analysis was made at 3-6 months (Baseline), 12, and 24 months after a first clinical event. We also performed a sub-analysis of patients that received glatiramer acetate (GLAT) after their baseline visit up to 24 months after the first clinical event.

Results

Our analysis revealed monocyte and B cell differences between groups. Percentages of CD19+CD20+B cells were lower in CIS patients compared to healthy individuals at baseline. Additionally, monocyte distribution among groups was different. A subgroup analysis of patients treated with GLAT (n= 10) showed an increased percentage of naïve (p<0.05) and memory pre-switched (p<0.01) B cells up to 24 months after their baseline visit compared to the untreated group (n= 10).

Conclusion

Our results showed early monocyte and B cell subsets alterations in pwCIS. Moreover, GLAT-treated patients showed an increased percentage of naïve and memory pre-switched B cells after 24 months of treatment. Further research is needed to elucidate the role of B cells and monocyte disturbances during inflammatory processes after a first clinically-MS suggestive event.
MaSk-LMM: A Matrix Sketching Framework for Linear Mixed Models in Association Studies
Authors: Burch Myson , Bose Aritra , Dexter Gregory , Parida Laxmi , Drineas Petros
Published: November 2023

Linear mixed models (LMMs) have been widely used in genome-wide association studies (GWAS) to control for population stratification and cryptic relatedness. Unfortunately, estimating LMM parameters is computationally expensive, necessitating large-scale matrix operations to build the genetic relatedness matrix (GRM). Over the past 25 years, Randomized Linear Algebra has provided alternative approaches to such matrix operations by leveragingmatrix sketching, which often results in provably accurate fast and efficient approximations. We leveragematrix sketchingto develop a fast and efficient LMM method calledMatrix-SketchingLMM(MaSk-LMM) by sketching the genotype matrix to reduce its dimensions and speed up computations. Our framework comes with both theoretical guarantees and a strong empirical performance compared to current state-of-the-art.
Mapping the common barriers to optimal COPD care in high and middle-income countries: qualitative perspectives from clinicians
Authors: Shahaj Orjola , Meiwald Anne , Sudhir Krishnan Puri , Gara-Adams Rupert , Wark Peter , Cazaux Alexis , Rios Abelardo Elizondo , Avdeev Sergey , Adams Elisabeth J
Published: November 2023

Background

Although predominantly preventable and treatable, chronic obstructive pulmonary disease (COPD) is a leading cause of death globally. Guidelines for managing the condition are widely available, yet COPD care remains suboptimal in many settings, including high and middle-income countries (HICs and MICs). Several approaches are used to diagnose and manage COPD, resulting in substantial variation in its care pathways. This study aimed to explore how barriers to optimal COPD care vary across HICs and MICs by identifying common and unique barriers to COPD care in six countries to inform global policy initiatives for better care while addressing specific challenges.

Methods

Based on international and national guidelines, we mapped COPD care pathways for Australia, Spain, Taiwan, Argentina, Mexico, and Russia. Country-specific pathways were populated with published epidemiological, health economic, and clinical data identified through a pragmatic literature review. Semi-structured interviews with 17 respiratory care clinicians further informed and validated the pathways, data inputs, and key issues arising in each country. Thematic content analysis was used to analyse common and unique barriers across countries.

Results

Six themes were common in most HICs and MICs:“Challenges in COPD diagnosis”, “Strengthening the role of primary care”, “Fragmented healthcare systems and coordination challenges”, “Inadequate management of COPD exacerbations”; “Limited access to specialised care” and, “Impact of underfinanced and overloaded healthcare systems”. One theme,“Insurance coverage and reimbursement challenges”, was more relevant for MICs.

HICs and MICs differ in patient and healthcare provider awareness, primary care involvement, spirometry access, and specialised care availability. Both face issues with healthcare fragmentation, guideline adherence, and COPD exacerbation management. MICs also grapple with resource limitations and healthcare infrastructure challenges.

Conclusion

Many challenges to COPD care are the same in both HICs and MICs, underscoring the pervasive nature of these issues. While country-specific issues require customised solutions, there are untapped possibilities for implementing global respiratory strategies that motivate countries to manage COPD effectively. In addition to healthcare system-level initiatives, there is a crucial need for political prioritisation of COPD to secure the essential resources it requires.
Prevalence, treatment, and factors associated with cryptococcal meningitis post introduction of integrase inhibitors antiretroviral based regimens among people living with HIV in Tanzania
Authors: Minja Makyao , Mbilinyi Tusaligwe , Mkinga Bryceson , Philipo Erick G. , Owenya Joyce , Kilonzi Manase
Published: November 2023

Objective

This study aimed to assess the prevalence of CM, treatment practice, and the associated factor’s post-introduction of Tenofovir Lamivudine and Dolutegravir (TLD) regimen among PLHIV in Tanzania.

Methods

This was an analytical cross-sectional study, and the data was collected retrospectively in three public regional referral hospitals (RRHs) in Dar es Salaam, Tanzania. A total of 405 files of the PLHIV admitted in the medical wards on the TLD regimen from January 2019 to December 2022 were reviewed. The collected information includes patient demographic characteristics, Cryptococcal status, CD4 level at the time of CM diagnosis, status of using ART, CM treatment approach, and outcome. Data was analyzed using SPSS software version 23.

Results

Out of 405, the majority 267(65.9%) were female, 224(55.3%) were aged between 36 - 55 years, and 293(72.3%) married. ART defaulters were found to be 37(9.1%). The prevalence of CM was found to be 48(11.9%), out of which 42(87.5%) received fluconazole alone. ART defaulter and marital status significantly (p-value < 0.05) were associated with those who tested CM positive.

Conclusion

The study found the prevalence of CM among PLHIV to be significantly high and the majority were treated with fluconazole alone. ART defaulters and marital status were significantly associated with one being CM positive. Responsible authorities and stakeholders should enforce guideline adherence and PLHIV should be encouraged on medication adherence.
Cryptococcus neoformans rapidly invades the murine brain by sequential breaching of airway and endothelial tissues barriers, followed by engulfment by microglia
Authors: Francis Vanessa I. , Liddle Corin , Camacho Emma , Kulkarni Madhura , Junior Samuel R.S. , Harvey Jamie A , Ballou Elizabeth R. , Thomson Darren D. , Hardwick J. Marie , Casadevall Arturo , Witton Jonathan , Coelho Carolina
Published: November 2023

The fungusCryptococcus neoformanscauses lethal meningitis in humans with weakened immune systems and is estimated to account for 10-15% of AIDS-associated deaths worldwide. There are major gaps in our understanding of how this environmental fungus evades the immune system and invades the mammalian brain before the onset of overt symptoms. To investigate the dynamics ofC. neoformanstissue invasion, we mapped early fungal localisation and host cell interactions at early times in infected brain, lung, and upper airways using mouse models of systemic and airway infection. To enable this, we developed anin situimaging pipeline capable of measuring large volumes of tissue while preserving anatomical and cellular information by combining thick tissue sections, tissue clarification, and confocal imaging. Made possible by these techniques, we confirm high fungal burden in mouse upper airway turbinates after nasal inoculation. Surprisingly, most yeasts in turbinates were titan cells, indicating this microenvironment enables titan cell formation with faster kinetics than reported in mouse lungs. Importantly, we observed one instance of fungal cells enmeshed in lamina propria of upper airways, suggesting penetration of airway mucosa as a possible route of tissue invasion and dissemination to the bloodstream. We extend previous literature positing bloodstream dissemination ofC. neoformans, via imagingC. neoformanswithin blood vessels of mouse lungs and finding viable fungi in the bloodstream of mice a few days after intranasal infection, suggesting that bloodstream access can occur via lung alveoli. In a model of systemic cryptococcosis, we show that as early as 24 h post infection, majority ofC. neoformanscells traversed the blood-brain barrier, and are engulfed or in close proximity to microglia. Our work establishes thatC. neoformanscan breach multiple tissue barriers within the first days of infection. This work presents a new method for investigating cryptococcal invasion mechanisms and demonstrates microglia as the primary cells responding to C. neoformans invasion.
Transcriptomic reprogramming screen identifies SRSF1 as rejuvenation factor
Authors: Plesa Alexandru M. , Jung Sascha , Wang Helen H. , Omar Fawad , Shadpour Michael , Buentello David Choy , Perez-Matos Maria C. , Horwitz Naftali , Cai George , Ngian Zhen-Kai , de Magalhaes Carol V. , Wagers Amy J. , Mair William B. , del Sol Antonio , Church George M.
Published: November 2023

Aging is a complex process that manifests through the time-dependent functional decline of a biological system. Age-related changes in epigenetic and transcriptomic profiles have been successfully used to measure the aging process1,2. Moreover, modulating gene regulatory networks through interventions such as the induction of the Yamanaka factors has been shown to reverse aging signatures and improve cell function3,4. However, this intervention has safety and efficacy limitations forin vivorejuvenation5,6, underscoring the need for identifying novel age reversal factors. Here, we discovered SRSF1 as a new rejuvenation factor that can improve cellular functionin vitroandin vivo. Using a cDNA overexpression screen with a transcriptomic readout we identified that SRSF1 induction reprograms the cell transcriptome towards a younger state. Furthermore, we observed beneficial changes in senescence, proteasome function, collagen production, and ROS stress upon SRSF1 overexpression. Lastly, we showed that SRSF1 can improve wound healingin vitroandin vivoand is linked to organismal longevity. Our study provides a proof of concept for using transcriptomic reprogramming screens in the discovery of age reversal interventions and identifies SRSF1 as a promising target for cellular rejuvenation.
3-phenyllactic acid promotes healthspan through SKN-1/ATFS-1-mediated mitochondrial activation and stress resilience
Authors: Kim Juewon , Jo Yunju , Lim Gyumin , Ji Yosep , Roh Jong-Hwa , Kim Wan-Gi , Yi Hyon-Seung , Choi Dong Wook , Cho Donghyun , Ryu Dongryeol
Published: November 2023

The mechanisms underlying the impact of probiotic supplementation on health remain largely elusive. While previous studies have primarily focused on the discovery of novel bioactive bacteria and alterations in the microbiome environment to explain potential probiotic effects, our research delves into the role of living lactic acid bacteria (LAB) and their conditioned media, highlighting that only the former, not dead bacteria, enhance the healthspan ofCaenorhabditis elegans. To elucidate the underlying mechanisms, we conducted transcriptomic profiling through RNA-seq analysis inC. elegansexposed to LAB or 3-phenyllactic acid (PLA), mimicking the presence of key candidate metabolites of LAB and evaluating healthspan. Our findings reveal that PLA treatment significantly extends the healthspan ofC. elegansby promoting energy metabolism and stress resilience in a SKN-1/ATFS-1-dependent manner. Moreover, PLA-mediated longevity is associated with a novel age-related parameter, the Healthy Aging Index (HAI), introduced in this study, which comprises healthspan-related factors such as motility, oxygen consumption rate (OCR), and ATP levels. Extending the relevance of our work to humans, we observed an inverse correlation between blood PLA levels and physical performance in patients with sarcopenia, when compared to age-matched non-sarcopenic controls. Our investigation thus sheds light on the pivotal role of the metabolite PLA in probiotics-mediated enhancement of organismal healthspan, and also hints at its potential involvement in age-related sarcopenia. These findings warrant further investigation to delineate PLA’s role in mitigating age-related declines in healthspan and resilience to external stressors.

Highlights

Metabolites Produced by Lactic Acid Bacteria Function as Mediators of Longevity inC. elegans

3-Phenyllactic Acid (PLA) Augmented Lifespan Extension and Elevated the Healthy Aging Index (HAI)

PLA Facilitated Healthy Aging by Inducing Mitochondrial Activation and Stress Resistance Dependent on SKN-1/ATFS-1

Patients with Sarcopenia and Symptoms of Frailty Exhibited Reduced Blood PLA Levels.
Effects of high fat and sugar diet on motivation for food and resistance to punishment in rats: role of sex and age of exposure
Authors: Desmercieres Stevenson , Lardeux Virginie , Longueville Jean-Emmanuel , Dugast Emilie , Thiriet Nathalie , Solinas Marcello
Published: November 2023

Exposure to food rich in fat and sugar (High Fat and Sugar Diet, HFSD) is believed to induce behavioral and neurobiological changes that would produce addiction-like behavior and increase the risks of obesity and overweight. Studies in rodents have led to conflicting results suggesting that several factors such as sex and age of exposure contribute to the development of maladaptive behavior towards food. In addition, it is not clear whether the effects of exposure to HFSD persist after its discontinuation which would indicate long-term risk to develop addiction-like behavior. In this study, we investigated the persistent effects of an intermittent 8-week exposure to HFSD in male and female rats as a function of age of exposure (adult and adolescent). We found that intermittent exposure to HFSD did not alter body weight, but it affected consumption of standard food during the time of exposure in all groups. In addition, in adults, HFSD produced a decrease in the initial baseline responding in FR1 schedules that persisted for 4 weeks in males but not in female rats. However, we found that exposure to HFSD did not affect resistance to punishment measured by progressive shock strength (PSS) break points or motivation for food measured by progressive-ratio break points regardless of sex or age of exposure. Altogether, these results do not provide support to the hypothesis that intermittent exposure to HFSD produce persistent increases in the vulnerability to develop addiction-like behaviors towards palatable food.
The dorsolateral striatum encodes a temporal basis for the organization of behavior
Authors: Rodrigues Filipe S. , Monteiro Tiago , Motiwala Asma , Paton Joseph J.
Published: November 2023

To behave adaptively, the brain must register temporal structure in the environment and use it to organize behavior. The dorsolateral striatum (DLS) integrates sensorimotor input, and is necessary for accurate timing and structuring behavior in general. However, if DLS provides the basis for mapping temporal features in the environment to behavior, its activity should predict variation in that mapping. A reanalysis of DLS population activity in rats comparing the duration of two sequentially presented vibratory stimuli revealed a striking correspondence between neural activity and behavior. Varying vibration intensity of the second stimulus induced systematic biases in temporal judgments, and corresponding biases in multiple features of DLS activity during stimulus presentation, including population coding of time. In contrast, the same intensity manipulations applied to the first stimulus affected neither behavior nor neural activity. Furthermore, neuronal response profiles were best described as a continuum, arguing against hypotheses where categories of responses, e.g., ramping activity, selectively underpin temporal processing. These data represent important additional evidence that striatal population dynamics support the organization of behavior by mapping temporal information to action.
Structural insights in the GTP-driven monomerization and activation of a bacterial LRRK2 homologue using allosteric nanobodies
Authors: Galicia Christian , Guaitoli Giambattista , Fislage Marcus , Gloeckner Christian J. , Versées Wim
Published: November 2023

The Roco proteins are a family of GTPases, characterized by the conserved presence of a Roc-COR tandem domain. These proteins entered the limelight after mutations in human LRRK2 were identified as a major cause of familial Parkinson’s disease. LRRK2 is a large and complex protein combining a GTPase and protein kinase activity, and disease mutations increase the kinase activity, while presumably decreasing the GTPase activity. Although a cross-communication between both catalytic activities has been suggested, the underlying mechanisms and the regulatory role of the GTPase domain remain unknown. Recently, several structures of LRRK2 have been reported, but so far structures of Roco proteins in their activated GTP-bound state are lacking. Here, we use single particle cryo-EM to solve the structure of a simpler bacterial Roco protein (CtRoco) in its GTP-bound state, aided by the use of two conformation-specific nanobodies: NbRoco1and NbRoco2. This structure presents CtRoco in an active monomeric state, featuring very significant conformational changes compared to the previously solved nucleotide-free dimer structure. In particular, the structure shows a very large GTP-induced conformational change of the LRR domain, unleashing it from the Roc-COR domains, using the LRR-Roc linker as a hinge. Furthermore, this structure shows how NbRoco1and NbRoco2collaborate to activate CtRoco in an allosteric way. Altogether, our data provide important new insights in the activation mechanism of Roco proteins, with relevance to LRRK2 regulation, and suggest new routes for the allosteric modulation of their GTPase activity.
Tolerance to land-use changes through natural modulations of the plant microbiome
Authors: Zieschank Vincent , Muola Anne , Junker Robert R.
Published: November 2023

Land-use changes pose a threat to many ecosystems and are a major driver of species loss. Adaptations to altered environments or migration to more suitable habitats are potential mechanisms to resist global change, which can, however, lag behind rapid anthropogenic alterations of the environment. Our data show that rapid natural modulations of the plant microbiome in response to land-use change directly affect plant phenotype and performance, and thus increase plant tolerance to environmental changes. In a common garden experiment, the effects of the microbiome on the plant phenotype were stronger than the direct effects of fertilizer application and mowing. This finding was confirmed in a subsequent controlled laboratory experiment using plants inoculated with land-use-specific microbiomes. Therefore, natural modulations of the plant microbiome may be the key to species persistence and ecosystem stability. A prerequisite for this microbiome-mediated tolerance is the availability of diverse local sources of microorganisms that can function as a resource for rapid modulations in response to change. Thus, conservation efforts must protect microbial diversity, which can help mitigate the effects of global change and facilitate environmental and human health.
Adeno-associated virus (AAV2) can replicate its DNA by a rolling hairpin or rolling circle mechanism, depending on the helper virus
Authors: Lkharrazi Anouk , Tobler Kurt , Marti Sara , Bratus-Neuenschwander Anna , Vogt Bernd , Fraefel Cornel
Published: November 2023

Adeno-associated virus type 2 (AAV2) is a small, non-pathogenic, helper virus-dependent parvovirus with a single-stranded (ss) DNA genome of approximately 4.7 kb. AAV2 DNA replication requires the presence of a helper virus such as adenovirus type 5 (AdV5) or herpes simplex virus type 1 (HSV-1) and is generally assumed to occur as a strand-displacement rolling hairpin (RHR) mechanism initiated at the AAV2 3’ inverted terminal repeat (ITR). We have recently shown that AAV2 replication supported by HSV-1 leads to the formation of double-stranded head-to-tail concatemers, which provides evidence for a rolling circle replication (RCR) mechanism. We have revisited AAV2 DNA replication and specifically compared the formation of AAV2 replication intermediates in presence of either HSV-1 or AdV5 as the helper virus. The results confirmed that the AAV2 DNA replication mechanism is helper virus-dependent and follows a strand-displacement RHR mechanism when AdV5 is the helper virus and primarily an RCR mechanism when HSV-1 is the helper virus. We also demonstrate that recombination plays a negligible role in AAV2 genome replication. Interestingly, the formation of high molecular weight AAV2 DNA concatemers in presence of HSV-1 as the helper virus was dependent on an intact HSV-1 DNA polymerase.

Importance

AAV is a small helper virus-dependent, non-pathogenic parvovirus. The AAV genome replication mechanism was extensively studied in presence of AdV as the helper virus and described to proceed using RHR. Surprisingly, HSV-1 co-infection facilitates RCR of the AAV2 DNA. We directly compared AdV5 and HSV-1 supported AAV2 DNA replication and show that AAV2 can adapt its replication mechanism to the helper virus. Detailed understanding of the AAV replication mechanism expands our knowledge of virus biology and can contribute to increase gene therapy vector production.
Aberrant splicing exonizesC9ORF72repeat expansion in ALS/FTD
Authors: Yang Suzhou , Wijegunawardana Denethi , Sheth Udit , Veire Austin M. , Salgado Juliana M. S. , Agrawal Manasi , Zhou Jeffrey , Pereira João D. , Gendron Tania F. , Guo Junjie U.
Published: November 2023

A nucleotide repeat expansion (NRE) in the first annotated intron of theC9ORF72gene is the most common genetic cause of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). While C9 NRE-containing RNAs can be translated into several toxic dipeptide repeat proteins, how an intronic NRE can assess the translation machinery in the cytoplasm remains unclear. By capturing and sequencing NRE-containing RNAs from patient-derived cells, we found that C9 NRE was exonized by the usage of downstream 5ʹ splice sites and exported from the nucleus in a variety of spliced mRNA isoforms.C9ORF72aberrant splicing was substantially elevated in both C9 NRE+motor neurons and human brain tissues. Furthermore, NREs above the pathological threshold were sufficient to activate cryptic splice sites in reporter mRNAs. In summary, our results revealed a crucial and potentially widespread role of repeat-induced aberrant splicing in the biogenesis, localization, and translation of NRE-containing RNAs.
Psychometric Properties and Longitudinal Measurement Invariance of the Spanish Version of the Alcohol Expectancies Questionnaire – Short Form among Young Adult Binge Drinkers
Authors: González-Ponce Bella M. , Pilatti Angelina , Montejano Gabriela Rivarola , Bravo Adrian J. , Fernández-Calderón Fermín
Published: November 2023

Background

Longitudinal Measurement Invariance (LMI) is critically important to evaluate changes in the alcohol expectancies over time. However, few studies have yet explored the longitudinal properties of the Spanish EQ-SF.

Objectives

To examine the reliability, sources of validity (structural and concurrent validity), and LMI of the Spanish short version of the Alcohol Expectancy Questionnaire in a sample of young adults who engage in binge drinking.

Methods

The participants (n= 279; Mean age = 21.33,SD= 2.15; 48.4% female) completed the Spanish EQ-SF, and two months later they completed this measure again, along with measures to alcohol use, drinking motives, and protective behavioral strategies (PBS). Confirmatory Factor Analysis was used to identify which of two proposed models provided the best-fitting factor structure. We aimed to determine whether the best-fitting model was invariant across assessments and to evaluate the predictive validity and reliability of the scores.

Results

Our findings revealed that the eight-factor intercorrelated model provided the best fit. This model was invariant across assessments, providing evidence for longitudinal measurement invariance. Moreover, the scores showed adequate reliability (.68 to .90) and predictive validity (i.e., positive alcohol expectancies were positively related to alcohol use and drinking motives and negatively related to PBS).

Conclusion

Our results support the reliability, validity, and temporal invariance of the EQ-SF scores among Spanish young adults with binge drinking patterns. The evidence supports the suitability of this measure for accurately assessing changes in alcohol expectancies over time in interventions aimed at preventing binge drinking in young adults.
Tuberculosis-associated hemophagocytic lymphohistiocytosis: diagnostic challenges and determinants of outcome
Authors: Kurver Lisa , Seers Timothy , van Dorp Suzanne , van Crevel Reinout , Pollara Gabriele , van Laarhoven Arjan
Published: November 2023

Background

Tuberculosis (TB) can induce secondary hemophagocytic lymphohistiocytosis (HLH), a severe inflammatory syndrome with high mortality. To improve insight into optimal diagnostic and treatment strategies, we integrated all published reports of adult HIV-negative TB-associated HLH (TB-HLH) globally to define clinical characteristics and therapeutic approaches associated with improved survival.

Methods

PubMed, Embase, and Global Index Medicus were searched for eligible records. TB-HLH cases were categorized into patients with a confirmed TB diagnosis receiving antituberculosis treatment while developing HLH, and patients presenting with HLH of unknown cause later diagnosed with TB. We integrated patients’ clinical characteristics, diagnostic test results, and pre-specified parameters associated with survival into a logistic regression model.

Results

We identified 115 individually reported cases, 45 (39.1%) from low TB incidence countries (<10/100.000 per year). Compared to HLH patients with known TB (n=21), patients with HLH of unknown cause (n=94), more often had extrapulmonary TB (88.3% vs. 66.7%), while the opposite was true for pulmonary disease (59.6% vs. 91.5%). Overall,Mycobacterium tuberculosiswas identified in the bone marrow in 78.4% of patients for whom examination was reported (n=74). Only 10.5% (4/38) of patients tested had a positive tuberculin skin test or interferon gamma release assay. In-hospital survival was 71.9% (69/96) in those treated for TB and 0% (18/18) in those who did not receive antituberculosis treatment (p < 0.001).

Conclusions

Tuberculosis should be considered as a cause of unexplained HLH. TB-HLH is probably under-reported, and the diagnostic work-up of HLH patients should include bone marrow examination for evidence ofM. tuberculosisinfection. Prompt initiation of antituberculosis treatment will likely improve survival.

Key points

Hemophagocytic lymphohistiocytosis is an underreported complication of tuberculosis, often manifesting as extrapulmonary or miliary disease. TST and IGRA mostly show an anergic response. Threshold should be low bone marrow investigation for evidence ofM. tuberculosis,and commencement of antituberculosis treatment.