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Neurobiology of Disease Jun 2024The vagus nerve serves as an interoceptive relay between the body and the brain. Despite its well-established role in feeding behaviors, energy metabolism, and cognitive...
The vagus nerve serves as an interoceptive relay between the body and the brain. Despite its well-established role in feeding behaviors, energy metabolism, and cognitive functions, the intricate functional processes linking the vagus nerve to the hippocampus and its contribution to learning and memory dynamics remain still elusive. Here, we investigated whether and how the gut-brain vagal axis contributes to hippocampal learning and memory processes at behavioral, functional, cellular, and molecular levels. Our results indicate that the integrity of the vagal axis is essential for long-term recognition memories, while sparing other forms of memory. In addition, by combing multi-scale approaches, our findings show that the gut-brain vagal tone exerts a permissive role in scaling intracellular signaling events, gene expressions, hippocampal dendritic spines density as well as functional long-term plasticities (LTD and LTP). These results highlight the critical role of the gut-brain vagal axis in maintaining the spontaneous and homeostatic functions of hippocampal ensembles and in regulating their learning and memory functions. In conclusion, our study provides comprehensive insights into the multifaceted involvement of the gut-brain vagal axis in shaping time-dependent hippocampal learning and memory dynamics. Understanding the mechanisms underlying this interoceptive body-brain neuronal communication may pave the way for novel therapeutic approaches in conditions associated with cognitive decline, including neurodegenerative disorders.
PubMed: 38885849
DOI: 10.1016/j.nbd.2024.106569 -
PLoS Pathogens Jun 2024Influenza viruses transcribe and replicate their genome in the nucleus of the infected cells, two functions that are supported by the viral RNA-dependent RNA-polymerase...
Influenza viruses transcribe and replicate their genome in the nucleus of the infected cells, two functions that are supported by the viral RNA-dependent RNA-polymerase (FluPol). FluPol displays structural flexibility related to distinct functional states, from an inactive form to conformations competent for replication and transcription. FluPol machinery is constituted by a structurally-invariant core comprising the PB1 subunit stabilized with PA and PB2 domains, whereas the PA endonuclease and PB2 C-domains can pack in different configurations around the core. To get insights into the functioning of FluPol, we selected single-domain nanobodies (VHHs) specific of the influenza A FluPol core. When expressed intracellularly, some of them exhibited inhibitory activity on type A FluPol, but not on the type B one. The most potent VHH (VHH16) binds PA and the PA-PB1 dimer with an affinity below the nanomolar range. Ectopic intracellular expression of VHH16 in virus permissive cells blocks multiplication of different influenza A subtypes, even when induced at late times post-infection. VHH16 was found to interfere with the transport of the PA-PB1 dimer to the nucleus, without affecting its handling by the importin β RanBP5 and subsequent steps in FluPol assembly. Using FluPol mutants selected after passaging in VHH16-expressing cells, we identified the VHH16 binding site at the interface formed by PA residues with the N-terminus of PB1, overlapping or close to binding sites of two host proteins, ANP32A and RNA-polymerase II RPB1 subunit which are critical for virus replication and transcription, respectively. These data suggest that the VHH16 neutralization is likely due to several activities, altering the import of the PA-PB1 dimer into the nucleus as well as inhibiting specifically virus transcription and replication. Thus, the VHH16 binding site represents a new Achilles' heel for FluPol and as such, a potential target for antiviral development.
Topics: Single-Domain Antibodies; Humans; Antiviral Agents; Influenza A virus; Virus Replication; Animals; RNA-Dependent RNA Polymerase; Viral Proteins; Influenza, Human; HEK293 Cells; Dogs; Madin Darby Canine Kidney Cells
PubMed: 38875296
DOI: 10.1371/journal.ppat.1011642 -
Nature Communications Jun 2024T cell receptor (TCR) signaling regulates important developmental transitions, partly through induction of the E protein antagonist, Id3. Although normal γδ T cell...
T cell receptor (TCR) signaling regulates important developmental transitions, partly through induction of the E protein antagonist, Id3. Although normal γδ T cell development depends on Id3, Id3 deficiency produces different phenotypes in distinct γδ T cell subsets. Here, we show that Id3 deficiency impairs development of the Vγ3 subset, while markedly enhancing development of NKγδT cells expressing the invariant Vγ1Vδ6.3 TCR. These effects result from Id3 regulating both the generation of the Vγ1Vδ6.3 TCR and its capacity to support development. Indeed, the Trav15 segment, which encodes the Vδ6.3 TCR subunit, is directly bound by E proteins that control its expression. Once expressed, the Vγ1Vδ6.3 TCR specifies the innate-like NKγδT cell fate, even in progenitors beyond the normally permissive perinatal window, and this is enhanced by Id3-deficiency. These data indicate that the paradoxical behavior of NKγδT cells in Id3-deficient mice is determined by its stereotypic Vγ1Vδ6.3 TCR complex.
Topics: Animals; Inhibitor of Differentiation Proteins; Receptors, Antigen, T-Cell, gamma-delta; Mice; Mice, Knockout; Mice, Inbred C57BL; Cell Differentiation; T-Lymphocyte Subsets; Signal Transduction
PubMed: 38871720
DOI: 10.1038/s41467-024-49496-3 -
Nature Communications Jun 2024Mood disorders are an enigmatic class of debilitating illnesses that affect millions of individuals worldwide. While chronic stress clearly increases incidence levels of...
Mood disorders are an enigmatic class of debilitating illnesses that affect millions of individuals worldwide. While chronic stress clearly increases incidence levels of mood disorders, including major depressive disorder (MDD), stress-mediated disruptions in brain function that precipitate these illnesses remain largely elusive. Serotonin-associated antidepressants (ADs) remain the first line of therapy for many with depressive symptoms, yet low remission rates and delays between treatment and symptomatic alleviation have prompted skepticism regarding direct roles for serotonin in the precipitation and treatment of affective disorders. Our group recently demonstrated that serotonin epigenetically modifies histone proteins (H3K4me3Q5ser) to regulate transcriptional permissiveness in brain. However, this non-canonical phenomenon has not yet been explored following stress and/or AD exposures. Here, we employed a combination of genome-wide and biochemical analyses in dorsal raphe nucleus (DRN) of male and female mice exposed to chronic social defeat stress, as well as in DRN of human MDD patients, to examine the impact of stress exposures/MDD diagnosis on H3K4me3Q5ser dynamics, as well as associations between the mark and depression-related gene expression. We additionally assessed stress-induced/MDD-associated regulation of H3K4me3Q5ser following AD exposures, and employed viral-mediated gene therapy in mice to reduce H3K4me3Q5ser levels in DRN and examine its impact on stress-associated gene expression and behavior. We found that H3K4me3Q5ser plays important roles in stress-mediated transcriptional plasticity. Chronically stressed mice displayed dysregulated H3K4me3Q5ser dynamics in DRN, with both AD- and viral-mediated disruption of these dynamics proving sufficient to attenuate stress-mediated gene expression and behavior. Corresponding patterns of H3K4me3Q5ser regulation were observed in MDD subjects on vs. off ADs at their time of death. These findings thus establish a neurotransmission-independent role for serotonin in stress-/AD-associated transcriptional and behavioral plasticity, observations of which may be of clinical relevance to human MDD and its treatment.
Topics: Animals; Dorsal Raphe Nucleus; Histones; Male; Female; Stress, Psychological; Humans; Antidepressive Agents; Depressive Disorder, Major; Mice; Serotonin; Mice, Inbred C57BL; Epigenesis, Genetic; Behavior, Animal; Gene Expression Regulation; Social Defeat
PubMed: 38871707
DOI: 10.1038/s41467-024-49336-4 -
Clinical Practice and Cases in... May 2024Severe hypernatremia is a critical situation, and when coupled with intravascular depletion and hypotension can create a treatment dilemma.
INTRODUCTION
Severe hypernatremia is a critical situation, and when coupled with intravascular depletion and hypotension can create a treatment dilemma.
CASE REPORT
We present the case of a medically complex patient who had gradually worsening alteration of mental status and mean arterial pressures in the 50s on presentation to the emergency department.
CONCLUSION
Final diagnoses included severe hypernatremia and hypovolemic shock secondary to poor oral intake. We used judicious fluid repletion with gradual improvement in sodium levels and permissive hypotension to avoid rapid osmotic shifts. Balancing reperfusion and the risk for osmotic effects of aggressive fluid resuscitation can be a challenging situation for the multidisciplinary team.
PubMed: 38869336
DOI: 10.5811/cpcem.1422 -
Microbiology Spectrum Jun 2024The emergence of the COVID-19 pandemic prompted an increased interest in seasonal human coronaviruses. OC43, 229E, NL63, and HKU1 are endemic seasonal coronaviruses that...
The emergence of the COVID-19 pandemic prompted an increased interest in seasonal human coronaviruses. OC43, 229E, NL63, and HKU1 are endemic seasonal coronaviruses that cause the common cold and are associated with generally mild respiratory symptoms. In this study, we identified cell lines that exhibited cytopathic effects (CPE) upon infection by three of these coronaviruses and characterized their viral replication kinetics and the effect of infection on host surface receptor expression. We found that NL63 produced CPE in LLC-MK2 cells, while OC43 produced CPE in MRC-5, HCT-8, and WI-38 cell lines, while 229E produced CPE in MRC-5 and WI-38 by day 3 post-infection. We observed a sharp increase in nucleocapsid and spike viral RNA (vRNA) from day 3 to day 5 post-infection for all viruses; however, the abundance and the proportion of vRNA copies measured in the supernatants and cell lysates of infected cells varied considerably depending on the virus-host cell pair. Importantly, we observed modulation of coronavirus entry and attachment receptors upon infection. Infection with 229E and OC43 led to a downregulation of CD13 and GD3, respectively. In contrast, infection with NL63 and OC43 leads to an increase in ACE2 expression. Attempts to block entry of NL63 using either soluble ACE2 or anti-ACE2 monoclonal antibodies demonstrated the potential of these strategies to greatly reduce infection. Overall, our results enable a better understanding of seasonal coronaviruses infection kinetics in permissive cell lines and reveal entry receptor modulation that may have implications in facilitating co-infections with multiple coronaviruses in humans.IMPORTANCESeasonal human coronavirus is an important cause of the common cold associated with generally mild upper respiratory tract infections that can result in respiratory complications for some individuals. There are no vaccines available for these viruses, with only limited antiviral therapeutic options to treat the most severe cases. A better understanding of how these viruses interact with host cells is essential to identify new strategies to prevent infection-related complications. By analyzing viral replication kinetics in different permissive cell lines, we find that cell-dependent host factors influence how viral genes are expressed and virus particles released. We also analyzed entry receptor expression on infected cells and found that these can be up- or down-modulated depending on the infecting coronavirus. Our findings raise concerns over the possibility of infection enhancement upon co-infection by some coronaviruses, which may facilitate genetic recombination and the emergence of new variants and strains.
PubMed: 38864599
DOI: 10.1128/spectrum.04220-23 -
Journal of Experimental & Clinical... Jun 2024Cancer-associated fibroblasts (CAFs) play a significant role in fueling prostate cancer (PCa) progression by interacting with tumor cells. A previous gene expression...
BACKGROUND
Cancer-associated fibroblasts (CAFs) play a significant role in fueling prostate cancer (PCa) progression by interacting with tumor cells. A previous gene expression analysis revealed that CAFs up-regulate genes coding for voltage-gated cation channels, as compared to normal prostate fibroblasts (NPFs). In this study, we explored the impact of antiarrhythmic drugs, known cation channel inhibitors, on the activated state of CAFs and their interaction with PCa cells.
METHODS
The effect of antiarrhythmic treatment on CAF activated phenotype was assessed in terms of cell morphology and fibroblast activation markers. CAF contractility and migration were evaluated by 3D gel collagen contraction and scratch assays, respectively. The ability of antiarrhythmics to impair CAF-PCa cell interplay was investigated in CAF-PCa cell co-cultures by assessing tumor cell growth and expression of epithelial-to-mesenchymal transition (EMT) markers. The effect on in vivo tumor growth was assessed by subcutaneously injecting PCa cells in SCID mice and intratumorally administering the medium of antiarrhythmic-treated CAFs or in co-injection experiments, where antiarrhythmic-treated CAFs were co-injected with PCa cells.
RESULTS
Activated fibroblasts show increased membrane conductance for potassium, sodium and calcium, consistently with the mRNA and protein content analysis. Antiarrhythmics modulate the expression of fibroblast activation markers. Although to a variable extent, these drugs also reduce CAF motility and hinder their ability to remodel the extracellular matrix, for example by reducing MMP-2 release. Furthermore, conditioned medium and co-culture experiments showed that antiarrhythmics can, at least in part, reverse the protumor effects exerted by CAFs on PCa cell growth and plasticity, both in androgen-sensitive and castration-resistant cell lines. Consistently, the transcriptome of antiarrhythmic-treated CAFs resembles that of tumor-suppressive NPFs. In vivo experiments confirmed that the conditioned medium or the direct coinjection of antiarrhythmic-treated CAFs reduced the tumor growth rate of PCa xenografts.
CONCLUSIONS
Collectively, such data suggest a new therapeutic strategy for PCa based on the repositioning of antiarrhythmic drugs with the aim of normalizing CAF phenotype and creating a less permissive tumor microenvironment.
Topics: Male; Humans; Prostatic Neoplasms; Anti-Arrhythmia Agents; Mice; Animals; Cancer-Associated Fibroblasts; Phenotype; Cell Line, Tumor; Drug Repositioning; Mice, SCID; Xenograft Model Antitumor Assays; Epithelial-Mesenchymal Transition; Cell Movement
PubMed: 38858661
DOI: 10.1186/s13046-024-03081-0 -
BioRxiv : the Preprint Server For... Jun 2024Rift Valley fever virus (RVFV) infection causes abortions in ruminant livestock and is associated with an increased likelihood of miscarriages in women. Using sheep and...
Rift Valley fever virus (RVFV) infection causes abortions in ruminant livestock and is associated with an increased likelihood of miscarriages in women. Using sheep and human placenta explant cultures, we sought to identify tissues at the maternal-fetal interface targeted by RVFV. Sheep villi and fetal membranes were highly permissive to RVFV infection resulting in markedly higher virus titers than human cultures. Sheep cultures were most permissive to wild-type RVFV and ΔNSm infection, while live attenuated RVFV vaccines (LAVs; MP-12, ΔNSs, and ΔNSs/ΔNSm) exhibited reduced replication. The human fetal membrane restricted wild-type and LAV replication, and when infection occurred, it was prominent in the maternal-facing side. Type-I and type-III interferons were induced in human villi exposed to LAVs lacking the NSs protein. This study supports the use of sheep and human placenta explants to understand vertical transmission of RVFV in mammals and whether LAVs are attenuated at the maternal-fetal interface.
PubMed: 38854055
DOI: 10.1101/2024.05.31.596800 -
Scientific Reports Jun 2024The pandemic of coronavirus disease 19 (COVID-19), caused by severe respiratory syndrome coronavirus 2 (SARS-CoV-2), had severe repercussions for breast cancer patients....
The pandemic of coronavirus disease 19 (COVID-19), caused by severe respiratory syndrome coronavirus 2 (SARS-CoV-2), had severe repercussions for breast cancer patients. Increasing evidence indicates that SARS-CoV-2 infection may directly impact breast cancer biology, but the effects of SARS-CoV-2 on breast tumor cells are still unknown. Here, we analyzed the molecular events occurring in the MCF7, MDA-MB-231 and HCC1937 breast cancer cell lines, representative of the luminal A, basal B/claudin-low and basal A subtypes, respectively, upon SARS-CoV-2 infection. Viral replication was monitored over time, and gene expression profiling was conducted. We found that MCF7 cells were the most permissive to viral replication. Treatment of MCF7 cells with Tamoxifen reduced the SARS-CoV-2 replication rate, suggesting an involvement of the estrogen receptor in sustaining virus replication in malignant cells. Interestingly, a metagene signature based on genes upregulated by SARS-CoV-2 infection in all three cell lines distinguished a subgroup of premenopausal luminal A breast cancer patients with a poor prognosis. As SARS-CoV-2 still spreads among the population, it is essential to understand the impact of SARS-CoV-2 infection on breast cancer, particularly in premenopausal patients diagnosed with the luminal A subtype, and to assess the long-term impact of COVID-19 on breast cancer outcomes.
Topics: Humans; Breast Neoplasms; COVID-19; Female; SARS-CoV-2; Virus Replication; Cell Line, Tumor; Tamoxifen; MCF-7 Cells; Gene Expression Profiling; Gene Expression Regulation, Neoplastic
PubMed: 38849411
DOI: 10.1038/s41598-024-63804-3 -
Nutrition Bulletin Jun 2024Research shows that features of food packaging can help to promote healthy food choices. Laboratory-based studies demonstrate that smart design of packaging facilitates...
Research shows that features of food packaging can help to promote healthy food choices. Laboratory-based studies demonstrate that smart design of packaging facilitates portion control. However, the extent to which consumers notice packaging features for portion control is not known. Therefore, this study investigated how individuals interact with food packaging, how they utilise the on-pack serving-size guidelines and how they make portion decisions. To do this, 25 adult participants were recruited to participate in an online semi-structured interview. Data were analysed using thematic analysis until saturation was achieved. Participants reported that they rarely attend to on-pack serving recommendations and indicated some resistance to them. Some structural features (small/single serving, pre-portioned and resealable packaging) were identified as facilitators of portion control. In contrast, the healthiness evaluation of the product from packaging cues was described as a permissive cue to eat more of the product. Participants in this study value their autonomy and control, preferring convenient behavioural choices over recommended portion servings. They also reported future concerns about the effects of their diet on health, but that current context (hunger, convenience) sometimes presented a barrier to healthy eating. Packaging does more than protect its contents, packaging can affect eating decisions to support portion control, and for some, offers permission to overconsume. This study identified ways that participants use packaging to make portion decisions, revealing the role of habits, current context and future health considerations. The interviews revealed the importance of consumer values on food choice in general and portion control in particular. In conclusion, smart food packaging design could use these findings to nudge healthy portion decisions by incorporating consumer values and by recognising consumer needs for habitual, current and future concerns.
PubMed: 38845598
DOI: 10.1111/nbu.12688