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1.
Cell ; 165(2): 289-302, 2016 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-27040497

RESUMO

Chromosomal translocations encode oncogenic fusion proteins that have been proven to be causally involved in tumorigenesis. Our understanding of whether such genomic alterations also affect non-coding RNAs is limited, and their impact on circular RNAs (circRNAs) has not been explored. Here, we show that well-established cancer-associated chromosomal translocations give rise to fusion circRNAs (f-circRNA) that are produced from transcribed exons of distinct genes affected by the translocations. F-circRNAs contribute to cellular transformation, promote cell viability and resistance upon therapy, and have tumor-promoting properties in in vivo models. Our work expands the current knowledge regarding molecular mechanisms involved in cancer onset and progression, with potential diagnostic and therapeutic implications.


Assuntos
Neoplasias/genética , RNA/metabolismo , Translocação Genética , Animais , Sequência de Bases , Proliferação de Células , Transformação Celular Neoplásica , Humanos , Leucemia/genética , Camundongos , Dados de Sequência Molecular , Proteína de Leucina Linfoide-Mieloide/genética , Neoplasias/patologia , Proteínas de Fusão Oncogênica/genética , RNA Circular
2.
Nat Immunol ; 18(12): 1342-1352, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29058703

RESUMO

T cells reorganize their metabolic profiles after being activated, but the systemic metabolic effect of sustained activation of the immune system has remained unexplored. Here we report that augmented T cell responses in Pdcd1-/- mice, which lack the inhibitory receptor PD-1, induced a metabolic serum signature characterized by depletion of amino acids. We found that the depletion of amino acids in serum was due to the accumulation of amino acids in activated Pdcd1-/- T cells in the lymph nodes. A systemic decrease in tryptophan and tyrosine led to substantial deficiency in the neurotransmitters serotonin and dopamine in the brain, which resulted in behavioral changes dominated by anxiety-like behavior and exacerbated fear responses. Together these data indicate that excessive activation of T cells causes a systemic metabolomic shift with consequences that extend beyond the immune system.


Assuntos
Ansiedade/fisiopatologia , Comportamento Animal/fisiologia , Medo/fisiologia , Ativação Linfocitária/imunologia , Receptor de Morte Celular Programada 1/genética , Linfócitos T/imunologia , Aminoácidos/sangue , Animais , Encéfalo/metabolismo , Dopamina/deficiência , Interferon gama/sangue , Cinurenina/sangue , Linfonodos/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Receptor de Morte Celular Programada 1/deficiência , Serotonina/deficiência , Linfócitos T/metabolismo , Triptofano/metabolismo , Tirosina/metabolismo
3.
Immunity ; 48(4): 628-631, 2018 04 17.
Artigo em Inglês | MEDLINE | ID: mdl-29669247

RESUMO

Disruption of the gut microbiota is thought to contribute to disease onset in individuals with a genetic predisposition to autoimmunity. In a recent issue of Science, Manfredo Vieira et al. (2018) identify translocation of the gut commensal Enterococcus gallinarum into the liver as a trigger for the autoimmune disease systemic lupus erythematous.


Assuntos
Autoimunidade , Lobos , Animais , Galinhas , Feminino , Microbioma Gastrointestinal , Humanos , Camundongos
5.
J Physiol ; 602(15): 3793-3814, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-39004870

RESUMO

High voltage-gated Ca2+ channels (HVCCs) shape the electrical activity and control hormone release in most endocrine cells. HVCCs are multi-subunit protein complexes formed by the pore-forming α1 and the auxiliary ß, α2δ and γ subunits. Four genes code for the α2δ isoforms. At the mRNA level, mouse chromaffin cells (MCCs) express predominantly the CACNA2D1 gene coding for the α2δ-1 isoform. Here we show that α2δ-1 deletion led to ∼60% reduced HVCC Ca2+ influx with slower inactivation kinetics. Pharmacological dissection showed that HVCC composition remained similar in α2δ-1-/- MCCs compared to wild-type (WT), demonstrating that α2δ-1 exerts similar functional effects on all HVCC isoforms. Consistent with reduced HVCC Ca2+ influx, α2δ-1-/- MCCs showed reduced spontaneous electrical activity with action potentials (APs) having a shorter half-maximal duration caused by faster rising and decay slopes. However, the induced electrical activity showed opposite effects with α2δ-1-/- MCCs displaying significantly higher AP frequency in the tonic firing mode as well as an increase in the number of cells firing AP bursts compared to WT. This gain-of-function phenotype was caused by reduced functional activation of Ca2+-dependent K+ currents. Additionally, despite the reduced HVCC Ca2+ influx, the intracellular Ca2+ transients and vesicle exocytosis or endocytosis were unaltered in α2δ-1-/- MCCs compared to WT during sustained stimulation. In conclusion, our study shows that α2δ-1 genetic deletion reduces Ca2+ influx in cultured MCCs but leads to a paradoxical increase in catecholamine secretion due to increased excitability. KEY POINTS: Deletion of the α2δ-1 high voltage-gated Ca2+ channel (HVCC) subunit reduces mouse chromaffin cell (MCC) Ca2+ influx by ∼60% but causes a paradoxical increase in induced excitability. MCC intracellular Ca2+ transients are unaffected by the reduced HVCC Ca2+ influx. Deletion of α2δ-1 reduces the immediately releasable pool vesicle exocytosis but has no effect on catecholamine (CA) release in response to sustained stimuli. The increased electrical activity and CA release from MCCs might contribute to the previously reported cardiovascular phenotype of patients carrying α2δ-1 loss-of-function mutations.


Assuntos
Potenciais de Ação , Canais de Cálcio , Células Cromafins , Animais , Células Cromafins/metabolismo , Células Cromafins/fisiologia , Camundongos , Canais de Cálcio/genética , Canais de Cálcio/metabolismo , Camundongos Knockout , Células Cultivadas , Cálcio/metabolismo , Exocitose/fisiologia , Camundongos Endogâmicos C57BL , Masculino
6.
J Physiol ; 2024 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-39320231

RESUMO

Microneurographic recordings of the human cervical vagus nerve have revealed the presence of multi-unit neural activity with measurable cardiac rhythmicity. This suggests that the physiology of vagal neurones with cardiovascular regulatory function can be studied using this method. Here, the activity of cardiac rhythmic single units was discriminated from human cervical vagus nerve recordings using template-based waveform matching. The activity of 44 cardiac rhythmic neurones (22 with myelinated axons and 22 with unmyelinated axons) was isolated. By consideration of each unit's firing pattern with respect to the cardiac and respiratory cycles, the functional identification of each unit was attempted. Of note is the observation of seven cardiac rhythmic neurones with myelinated axons whose activity was recruited or enhanced by slow, deep breathing, was maximal during the nadir of respiratory sinus arrhythmia, and showed an expiratory peak. This is characteristic of cardioinhibitory efferent neurones, which are responsible for respiratory sinus arrhythmia. The remaining 15 cardiac rhythmic neurones with myelinated axons were categorised as cardiopulmonary receptors or arterial baroreceptors based on the position of their peak in firing with respect to the R-wave of the cardiac cycle. This latter method is not viable for neurones with unmyelinated axons due to their slow and unknown conduction velocities. With the exception of three neurones whose expiratory modulation implicates them as cardiac-projecting efferent neurones, this population is likely dominated by arterial baroreceptors. In conclusion, the activity of single units with cardiovascular function has been discriminated within the human cervical vagus, enabling their systematic study. KEY POINTS: Recordings of the electrical activity of the vagus nerve have recently been made at the level of the neck in humans. Examination of the gross activity of this nerve reveals subpopulations of neurones whose activity fluctuates in time with the heart's beat, suggesting that the neurones that monitor or modify cardiac function can be studied using this method. Here, the activity of individual cardiac rhythmic neurones was isolated from human vagus nerve recordings using template-based spike sorting. The relationship between this activity and the cardiac and respiratory cycles was used as a means of classifying each neurone. Neuronal firing patterns that are consistent with that of neurones that modify cardiac function, including heart-slowing 'cardioinhibitory' neurones, as well as neurones that inform the brain of cardiovascular status were observed. This approach enables, for the first time, the systematic study of the function of these neurones in humans in both health and disease.

7.
Am J Physiol Gastrointest Liver Physiol ; 326(6): G659-G675, 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38591132

RESUMO

Probiotic-containing fermented dairy foods have the potential to benefit human health, but the importance of the dairy matrix for efficacy remains unclear. We investigated the capacity of Lacticaseibacillus paracasei BL23 in phosphate-buffered saline (BL23-PBS), BL23-fermented milk (BL23-milk), and milk to modify intestinal and behavioral responses in a dextran sodium sulfate (DSS, 3% wt/vol) mouse model of colitis. Significant sex-dependent differences were found such that female mice exhibited more severe colitis, greater weight loss, and higher mortality rates. Sex differences were also found for ion transport ex vivo, colonic cytokine and tight junction gene expression, and fecal microbiota composition. Measurements of milk and BL23 effects showed BL23-PBS consumption improved weight recovery in females, whereas milk resulted in better body weight recovery in males. Occludin and Claudin-2 gene transcript levels indicated barrier function was impaired in males, but BL23-milk was still found to improve colonic ion transport in those mice. Proinflammatory and anti-inflammatory gene expression levels were increased in both male and female mice fed BL23, and to a more variable extent, milk, compared with controls. The female mouse fecal microbiota contained high proportions of Akkermansia (average of 18.1%) at baseline, and females exhibited more changes in gut microbiota composition following BL23 and milk intake. Male fecal microbiota harbored significantly more Parasutterella and less Blautia and Roseburia after DSS treatment, independent of BL23 or milk consumption. These findings show the complex interplay between dietary components and sex-dependent responses in mitigating inflammation in the digestive tract.NEW & NOTEWORTHY Sex-dependent responses to probiotic Lacticaseibacillus paracasei and milk and the potential of the dairy matrix to enhance probiotic protection against colitis in this context have not been previously explored. Female mice were more sensitive than males to colonic injury, and neither treatment effectively alleviated inflammation in both sexes. These sex-dependent responses may result from differences in the higher baseline proportions of Akkermansia in the gut microbiome of female mice.


Assuntos
Colite , Sulfato de Dextrana , Modelos Animais de Doenças , Leite , Probióticos , Animais , Feminino , Probióticos/farmacologia , Masculino , Colite/microbiologia , Colite/induzido quimicamente , Colite/metabolismo , Camundongos , Microbioma Gastrointestinal , Camundongos Endogâmicos C57BL , Colo/metabolismo , Colo/microbiologia , Fatores Sexuais , Mucosa Intestinal/metabolismo , Mucosa Intestinal/microbiologia
8.
Immunity ; 43(6): 1174-85, 2015 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-26680207

RESUMO

The central nervous system (CNS) is an immunologically privileged site protected from uncontrolled access of T cells by the blood-brain barrier (BBB), which is breached upon autoimmune inflammation. Here we have shown that receptor activator of nuclear factor-κB (NF-κB) ligand (RANKL) on T cells regulates C-C type chemokine ligand 20 (CCL20) production by astrocytes and T cell localization in the CNS. Importantly, mice specifically lacking RANKL in T cells were resistant to experimental autoimmune encephalomyelitis (EAE) due to altered T cell trafficking. Pharmacological inhibition of RANKL prevented the development of EAE without affecting the peripheral immune response, indicating that RANKL is a potential therapeutic target for treating autoimmune diseases in the CNS.


Assuntos
Quimiotaxia de Leucócito/imunologia , Encefalomielite Autoimune Experimental/imunologia , Ligante RANK/imunologia , Linfócitos T/imunologia , Animais , Astrócitos/imunologia , Técnicas de Cocultura , Ensaio de Imunoadsorção Enzimática , Citometria de Fluxo , Imuno-Histoquímica , Ativação Linfocitária/imunologia , Camundongos , Camundongos Knockout , Ligante RANK/deficiência , Reação em Cadeia da Polimerase em Tempo Real
9.
Prev Med ; 184: 107994, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38723779

RESUMO

BACKGROUND: The potential health effects of taxing sugar-sweetened beverages (SSBs) has been insufficiently examined in Asian contexts. This study aimed to assess the impact of SSB taxation on the prevalence of obesity/overweight and type 2 diabetes mellitus (T2DM) in Hong Kong using a willingness-to-pay (WTP) survey and simulation analysis. METHODS: A random telephone survey was conducted with 1000 adults from May to June 2020. We used a contingent valuation approach to assess individuals' WTP for SSBs under four tax payment scenarios (5%, 10%, 40%, and 50% of the current market price). Based on the WTP, a simulation analysis was conducted to project changes in SSB purchase and associated reductions in the prevalence of obesity/overweight and T2DM over a 10-year simulation period. FINDINGS: When 5% and 10% taxation rates were introduced, approximately one-third of the population were unwilling to maintain their SSB purchase. Our simulation demonstrated a gradual decline in the prevalence of obesity/overweight and diabetes with a more pronounced decrease when higher taxation rates were introduced. 10% taxation resulted in a mean reduction of 1532.7 cases of overweight/obesity per 100 thousand population at the sixth year, while T2DM prevalence decreased by 267.1 (0.3%). CONCLUSIONS: This study underscores the effects of an SSB tax on purchase behaviors and health outcomes in an affluent Asia setting, with a more pronounced influence on adult population. These findings are expected to inform policymakers in making decisions regarding an effective and equitable tax rate on SSBs.


Assuntos
Diabetes Mellitus Tipo 2 , Obesidade , Sobrepeso , Bebidas Adoçadas com Açúcar , Impostos , Humanos , Diabetes Mellitus Tipo 2/epidemiologia , Bebidas Adoçadas com Açúcar/economia , Bebidas Adoçadas com Açúcar/estatística & dados numéricos , Masculino , Feminino , Obesidade/epidemiologia , Adulto , Sobrepeso/epidemiologia , Pessoa de Meia-Idade , Hong Kong/epidemiologia , Prevalência , Inquéritos e Questionários
10.
Proc Biol Sci ; 290(2013): 20231763, 2023 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-38087922

RESUMO

In everyday life during terrestrial locomotion our body interacts with two media opposing the forward movement of the body: the ground and the air. Whereas the work done to overcome the ground reaction force has been extensively studied, the work done to overcome still air resistance has been only indirectly estimated by means of theoretical studies and by measurements of the force exerted on puppets simulating the geometry of the human body. In this study, we directly measured the force exerted by still air resistance on eight male subjects during walking and running on an instrumented treadmill with a belt moving at the same speed of a flow of laminar air facing the subject. Overall, the coefficient of proportionality between drag and velocity squared (Aeff) was smaller during running than walking. During running Aeff decreased progressively with increasing average velocity up to an apparently constant, velocity independent value, similar to that predicted in the literature using indirect methods. A predictive equation to estimate drag as a function of the speed and the height of the running subject is provided.


Assuntos
Locomoção , Corrida , Caminhada , Humanos , Masculino , Fenômenos Biomecânicos , Marcha , Fenômenos Mecânicos , Ar
11.
Nano Lett ; 22(14): 5765-5772, 2022 07 27.
Artigo em Inglês | MEDLINE | ID: mdl-35833741

RESUMO

We characterize in situ grown parallel nanowires bridged by a superconducting island. The magnetic-field and temperature dependence of Coulomb blockade peaks measured across different pairs of nanowire ends suggest the presence of a subgap state extended over the hybrid parallel-nanowire island. Being gate-tunable, accessible by multiple terminals, and free of quasiparticle poisoning, these nanowires show promise for the implementation of several proposals that rely on parallel nanowire platforms.


Assuntos
Nanofios , Transporte de Elétrons , Eletrônica , Temperatura
12.
J Physiol ; 600(13): 3113-3126, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35524982

RESUMO

We recently documented the first microelectrode recordings from the cervical vagus nerve in awake humans. Here we aimed to quantify cardiac and respiratory modulation of vagal activity to assess the feasibility of targeting axons supplying the heart and airways. Multi-unit activity was recorded from 43 sites in 19 healthy participants in the left (n = 10) and right (n = 9) vagus nerves with ECG, continuous non-invasive blood pressure and respiration. Cross-correlation histograms were constructed between axonal spikes and the R-waves or the peaks of inspiration. The latencies for the peak in cardiac modulation showed a bimodal distribution: while the majority of sites (72%) had peak latencies that preceded the R-wave by up to 550 ms (mean ± SD, -300 ± 178 ms), 12 sites had latencies of up to 250 ms following the R-wave (64 ± 87 ms). Interestingly, the majority of sites with negative latencies (68%) were found in the left nerve whereas most of those with positive latencies (75%) were found in the right. Conversely, on average the peak of respiratory modulation straddled the peak of inspiration. Sites showing respiratory modulation were more prevalent and showed stronger modulation than those with cardiac modulation: calculated for sites with modulation indices ≥15%, the median cardiac and respiratory modulation indices were 23.4% (n = 17) and 44.5% (n = 35), respectively. We conclude that, despite the fact that much of the vagus nerve supplies the gut, cardiac and respiratory modulation of vagal nerve activity can be identified through invasive recordings in awake humans. KEY POINTS: Intraneural recordings from the cervical vagus were obtained in awake humans via tungsten microelectrodes inserted into the nerve through ultrasound guidance. Cross-correlation analysis of multi-unit vagal activity revealed cardiac and respiratory modulation, from which the amplitude and latency of the peaks could be computed. The magnitude of the cardiac modulation (23%) was weaker than that of the respiratory modulation (45%). The latencies for the peak in cardiac modulation showed a bimodal distribution: the majority of sites (72%) had peak latencies that preceded the R-wave, while the remainder had latencies that followed the R-wave. The majority of sites with negative latencies (68%) were found in the left nerve whereas most of those with positive latencies (75%) were found in the right. On average the peak of respiratory modulation coincided with the peak of inspiration.


Assuntos
Coração , Nervo Vago , Axônios , Pressão Sanguínea , Coração/fisiologia , Humanos , Respiração , Nervo Vago/fisiologia
13.
FASEB J ; 35(10): e21899, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34569661

RESUMO

The cornea of the eye differs from other mucosal surfaces in that it lacks a viable bacterial microbiome and by its unusually high density of sensory nerve endings. Here, we explored the role of corneal nerves in preventing bacterial adhesion. Pharmacological and genetic methods were used to inhibit the function of corneal sensory nerves or their associated transient receptor potential cation channels TRPA1 and TRPV1. Impacts on bacterial adhesion, resident immune cells, and epithelial integrity were examined using fluorescent labeling and quantitative confocal imaging. TRPA1/TRPV1 double gene-knockout mice were more susceptible to adhesion of environmental bacteria and to that of deliberately-inoculated Pseudomonas aeruginosa. Supporting the involvement of TRPA1/TRPV1-expressing corneal nerves, P. aeruginosa adhesion was also promoted by treatment with bupivacaine, or ablation of TRPA1/TRPV1-expressing nerves using RTX. Moreover, TRPA1/TRPV1-dependent defense was abolished by enucleation which severs corneal nerves. High-resolution imaging showed normal corneal ultrastructure and surface-labeling by wheat-germ agglutinin for TRPA1/TRPV1 knockout murine corneas, and intact barrier function by absence of fluorescein staining. P. aeruginosa adhering to corneas after perturbation of nerve or TRPA1/TRPV1 function failed to penetrate the surface. Single gene-knockout mice showed roles for both TRPA1 and TRPV1, with TRPA1-/- more susceptible to P. aeruginosa adhesion while TRPV1-/- corneas instead accumulated environmental bacteria. Corneal CD45+/CD11c+ cell responses to P. aeruginosa challenge, previously shown to counter bacterial adhesion, also depended on TRPA1/TRPV1 and sensory nerves. Together, these results demonstrate roles for corneal nerves and TRPA1/TRPV1 in corneal resistance to bacterial adhesion in vivo and suggest that the mechanisms involve resident immune cell populations.


Assuntos
Aderência Bacteriana , Córnea , Pseudomonas aeruginosa/metabolismo , Canal de Cátion TRPA1/metabolismo , Canais de Cátion TRPV/metabolismo , Animais , Córnea/inervação , Córnea/metabolismo , Córnea/microbiologia , Feminino , Masculino , Camundongos , Camundongos Knockout , Canal de Cátion TRPA1/genética , Canais de Cátion TRPV/genética
14.
Behav Brain Funct ; 18(1): 5, 2022 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-35216588

RESUMO

BACKGROUND: Several findings suggest neuroinflammation as a contributing factor for the onset of psychiatric disorders such as Alzheimer's disease, depression, and anxiety. There is increasing evidence pointing out that the Mediterranean diet influences brain and behavior. Mediterranean herbs and spices have been shown to be within those components of the Mediterranean diet involved in cognitive enhancement. Thus, we investigated the influence of Mediterranean natural extracts (MNE), Rosemary extract (RE) and Glycyrrhiza glabra root extract (GGRE), on cognitive behavior. RESULTS: Adult zebrafish were exposed to RE or GGRE (100 and 250 mg/L) treatments. Both MNE improved memory retention during the T-maze test, although no improvements were observed during the novel object preference. Similarly, chronic administration of RE (150 mg/Kg) and GGRE (150 mg/Kg) improved, respectively, spatial and retention memory, as assessed by the Morris Water Maze (MWM), and the Elevated Plus Maze (EPM) in healthy male rats. However, no improvements were observed during the novel object recognition. Finally, male, and female rats were chronically treated with lipopolysaccharide [(LPS) 300 ug/kg] and orally administered with RE. Interestingly, RE reversed LPS-induced cognitive deficit during the MWM and EPM in female rats. CONCLUSIONS: We found that MNE improved cognition in both zebrafish and rats. Moreover, MNE rescued LPS-induced cognitive impairment in a gender-specific manner. Therefore, our study supports the view that zebrafish represent a valuable preclinical model for drug discovery in neuroscience. These findings contribute to an exciting and growing body of research suggesting that MNE may play an important role in the prevention of cognitive impairment.


Assuntos
Disfunção Cognitiva , Lipopolissacarídeos , Animais , Cognição , Disfunção Cognitiva/induzido quimicamente , Disfunção Cognitiva/tratamento farmacológico , Modelos Animais de Doenças , Feminino , Hipocampo , Lipopolissacarídeos/efeitos adversos , Masculino , Aprendizagem em Labirinto , Transtornos da Memória/tratamento farmacológico , Extratos Vegetais/farmacologia , Extratos Vegetais/uso terapêutico , Ratos , Peixe-Zebra
15.
Health Econ ; 31(4): 614-646, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-34989067

RESUMO

'Nudge'-based social norms messages conveying high population influenza vaccination coverage levels can encourage vaccination due to bandwagoning effects but also discourage vaccination due to free-riding effects on low risk of infection, making their impact on vaccination uptake ambiguous. We develop a theoretical framework to capture heterogeneity around vaccination behaviors, and empirically measure the causal effects of different messages about vaccination coverage rates on four self-reported and behavioral vaccination intention measures. In an online experiment, N = 1365 UK adults are randomly assigned to one of seven treatment groups with different messages about their social environment's coverage rate (varied between 10% and 95%), or a control group with no message. We find that treated groups have significantly greater vaccination intention than the control. Treatment effects increase with the coverage rate up to a 75% level, consistent with a bandwagoning effect. For coverage rates above 75%, the treatment effects, albeit still positive, stop increasing and remain flat (or even decline). Our results suggest that, at higher coverage rates, free-riding behavior may partially crowd out bandwagoning effects of coverage rate messages. We also find significant heterogeneity of these effects depending on the individual perceptions of risks of infection and of the coverage rates.


Assuntos
Vacinas contra Influenza , Influenza Humana , Adulto , Humanos , Vacinas contra Influenza/uso terapêutico , Influenza Humana/prevenção & controle , Intenção , Vacinação , Cobertura Vacinal
16.
Infect Immun ; 89(9): e0005921, 2021 08 16.
Artigo em Inglês | MEDLINE | ID: mdl-33820817

RESUMO

Diarrheal diseases are a leading cause of death in children under the age of 5 years worldwide. Repeated early-life exposures to diarrheal pathogens can result in comorbidities including stunted growth and cognitive deficits, suggesting an impairment in the microbiota-gut-brain (MGB) axis. Neonatal C57BL/6 mice were infected with enteropathogenic Escherichia coli (EPEC) (strain e2348/69; ΔescV [type III secretion system {T3SS} mutant]) or the vehicle (Luria-Bertani [LB] broth) via orogastric gavage at postnatal day 7 (P7). Behavior (novel-object recognition [NOR] task, light/dark [L/D] box, and open-field test [OFT]), intestinal physiology (Ussing chambers), and the gut microbiota (16S Illumina sequencing) were assessed in adulthood (6 to 8 weeks of age). Neonatal infection of mice with EPEC, but not the T3SS mutant, caused ileal inflammation in neonates and impaired recognition memory (NOR task) in adulthood. Cognitive impairments were coupled with increased neurogenesis (Ki67 and doublecortin immunostaining) and neuroinflammation (increased microglia activation [Iba1]) in adulthood. Intestinal pathophysiology in adult mice was characterized by increased secretory state (short-circuit current [Isc]) and permeability (conductance) (fluorescein isothiocyanate [FITC]-dextran flux) in the ileum and colon of neonatally EPEC-infected mice, along with increased expression of proinflammatory cytokines (Tnfα, Il12, and Il6) and pattern recognition receptors (Nod1/2 and Tlr2/4). Finally, neonatal EPEC infection caused significant dysbiosis of the gut microbiota, including decreased Firmicutes, in adulthood. Together, these findings demonstrate that infection in early life can significantly impair the MGB axis in adulthood.


Assuntos
Encéfalo/metabolismo , Escherichia coli Enteropatogênica/fisiologia , Infecções por Escherichia coli/metabolismo , Infecções por Escherichia coli/microbiologia , Retroalimentação Fisiológica , Microbioma Gastrointestinal , Intestinos , Animais , Suscetibilidade a Doenças , Humanos
17.
Brain Behav Immun ; 91: 437-450, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33157256

RESUMO

Myelination in the peripheral and central nervous systems is critical in regulating motor, sensory, and cognitive functions. As myelination occurs rapidly during early life, neonatal gut dysbiosis during early colonization can potentially alter proper myelination by dysregulating immune responses and neuronal differentiation. Despite common usage of antibiotics (Abx) in children, the impact of neonatal Abx-induced dysbiosis on the development of microbiota, gut, brain (MGB) axis, including myelination and behavior, is unknown. We hypothesized that neonatal Abx-induced dysbiosis dysregulates host-microbe interactions, impairing myelination in the brain, and altering the MGB axis. Neonatal C57BL/6 mice were orally gavaged daily with an Abx cocktail (neomycin, vancomycin, ampicillin) or water (vehicle) from postnatal day 7 (P7) until weaning (P23) to induce gut dysbiosis. Behavior (cognition; anxiety-like behavior), microbiota sequencing, and qPCR (ileum, colon, hippocampus and pre-frontal cortex [PFC]) were performed in adult mice (6-8 weeks). Neonatal Abx administration led to intestinal dysbiosis in adulthood, impaired intestinal physiology, coupled with perturbations of bacterial metabolites and behavioral alterations (cognitive deficits and anxiolytic behavior). Expression of myelin-related genes (Mag, Mog, Mbp, Mobp, Plp) and transcription factors (Sox10, Myrf) important for oligodendrocytes were significantly increased in the PFC region of Abx-treated mice. Increased myelination was confirmed by immunofluorescence imaging and western blot analysis, demonstrating increased expression of MBP, SOX10 and MYRF in neonatally Abx-treated mice compared to sham controls in adulthood. Finally, administration of the short chain fatty acid butyrate following completion of the Abx treatment restored intestinal physiology, behavior, and myelination impairments, suggesting a critical role for the gut microbiota in mediating these effects. Taken together, we identified a long-lasting impact of neonatal Abx administration on the MGB axis, specifically on myelin regulation in the PFC region, potentially contributing to impaired cognitive function and bacterial metabolites are effective in reversing this altered phenotype.


Assuntos
Microbioma Gastrointestinal , Microbiota , Animais , Antibacterianos , Encéfalo , Camundongos , Camundongos Endogâmicos C57BL , Bainha de Mielina
18.
J Physiol ; 598(17): 3569-3576, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32538473

RESUMO

KEY POINTS: The vagus nerve is the largest cranial nerve and innervates many structures in the neck, thorax and abdomen. Although single-unit recordings from the vagus nerve have been performed in experimental animals for several decades, no recordings have ever been made from the human vagus nerve. The vagus nerve is routinely stimulated clinically, yet we know little of its physiology in humans. We describe the methodology and provide preliminary results of the first intraneural single-unit recordings from the cervical vagus in awake humans, using tungsten microelectrodes inserted into the nerve through ultrasound guidance. ABSTRACT: Intraneural microelectrodes have been used extensively to record from single somatosensory axons supplying muscle, tendons, joints and skin, as well as to record from postganglionic sympathetic axons supplying muscle and skin, in accessible peripheral nerves in awake humans. However, the vagus nerve has never been targeted, probably because of its close proximity to the carotid artery and jugular vein in the neck. Here, we report the first unitary recordings from the human cervical vagus nerve, obtained using ultrasound-guided insertion of tungsten microelectrodes into fascicles of the nerve. We identified tonically-active neurones in which firing rates were inversely related to heart rate (and directly related to the cardiac interval), which we classified as putative preganglionic parasympathetic axons directed to the sinoatrial node of the heart. We also recorded from tonically-active presumed sensory axons from the airways and presumed motor axons to the larynx. This new methodology opens exciting new opportunities for studying the physiology of the human vagus nerve in health and disease.


Assuntos
Neurônios , Nervo Vago , Animais , Axônios , Humanos , Microeletrodos , Ultrassonografia de Intervenção , Nervo Vago/diagnóstico por imagem
19.
Eur J Neurosci ; 51(4): 1042-1058, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31339598

RESUMO

Nutritional interventions targeting the microbiota-gut-brain axis are proposed to modulate stress-induced dysfunction of physiological processes and brain development. Maternal separation (MS) in rats induces long-term alterations to behaviour, pain responses, gut microbiome and brain neurochemistry. In this study, the effects of dietary interventions (milk fat globule membrane [MFGM] and a polydextrose/galacto-oligosaccharide prebiotic blend) were evaluated. Diets were provided from postnatal day 21 to both non-separated and MS offspring. Spatial memory, visceral sensitivity and stress reactivity were assessed in adulthood. Gene transcripts associated with cognition and stress and the caecal microbiota composition were analysed. MS-induced visceral hypersensitivity was ameliorated by MFGM and to greater extent with the combination of MFGM and prebiotic blend. Furthermore, spatial learning and memory were improved by prebiotics and MFGM alone and with the combination. The prebiotic blend and the combination of the prebiotics and MFGM appeared to facilitate return to baseline with regard to HPA axis response to the restraint stress, which can be beneficial in times where coping mechanisms to stressful events are required. Interestingly, the combination of MFGM and prebiotic reduced the long-term impact of MS on a marker of myelination in the prefrontal cortex. MS affected the microbiota at family level only, while MFGM, the prebiotic blend and the combination influenced abundance at family and genus level as well as influencing beta-diversity levels. In conclusion, intervention with MFGM and prebiotic blend significantly impacted the composition of the microbiota as well as ameliorating some of the long-term effects of early-life stress.


Assuntos
Microbioma Gastrointestinal , Privação Materna , Microbiota , Animais , Encéfalo , Glicolipídeos , Glicoproteínas , Sistema Hipotálamo-Hipofisário , Gotículas Lipídicas , Sistema Hipófise-Suprarrenal , Prebióticos , Ratos , Estresse Fisiológico
20.
HPB (Oxford) ; 22(4): 570-577, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-31530450

RESUMO

BACKGROUND: Recent studies validated the possibility to detach colorectal liver metastases from vessels (R1vasc) featuring R1vasc equivalent to R0 and superior to tumor exposure along the transection plane (R1par). To clarify the outcome of R1 surgery (margin <1 mm) in patients with intrahepatic cholangiocarcinoma (MFCCC), distinguishing R1par and R1vasc resections. METHODS: Patients undergoing resection for MFCCC between 2008 and 2016 were considered. Tumor detachment from 1st/2nd-order Glissonean pedicles or hepatic veins was performed in advanced diseases. R0, R1par, and R1vasc were compared. RESULTS: The study included 84 resection areas in 59 patients (17 R1vasc). R1vasc group had local recurrence risk similar to R1par group (per-patient analysis 29% vs. 36%; per-resection area analysis 29% vs. 32%), higher than R0 group (3% and 2%, p = 0.003 and p = 0.0003). R1vasc and R1par groups had similar overall and recurrence-free survival (median OS 30 vs. 30 months; RFS 10 vs. 8 months), lower than R0 group (70 and 39 months, p = 0.066 and p = 0.007). CONCLUSION: In MFCCC patients, R1vasc resection is not an adequate treatment. Local disease control and survival after R1vasc resection are lower than after R0 resection and similar to R1par resection. R1vasc resection could be exclusively considered to achieve resectability in otherwise unresectable patients.


Assuntos
Neoplasias dos Ductos Biliares/patologia , Neoplasias dos Ductos Biliares/cirurgia , Colangiocarcinoma/patologia , Colangiocarcinoma/cirurgia , Margens de Excisão , Idoso , Neoplasias dos Ductos Biliares/mortalidade , Colangiocarcinoma/mortalidade , Estudos de Coortes , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Taxa de Sobrevida , Resultado do Tratamento
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