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An 87-year-old woman was hospitalized for liver abscesses and cholangitis due to common bile duct stones. She developed worsening anemia and abdominal pain. Contrast-enhanced computed tomography revealed an intrahepatic pseudoaneurysm and an arteriovenous fistula between the hepatic arteries and inferior vena cava. The initial endovascular treatment was transarterial embolization. The pseudoaneurysm was embolized with an N-butyl-2-cyanoacrylate mixture, and the inflow arteries of the arteriovenous fistula were embolized with microcoils. However, the residual perfusion of the arteriovenous fistula remained. A second endovascular treatment was performed using the transarterial and transvenous approaches. The inflow arteries were embolized using microcoils and gelatin sponges and the dominant outflow vein was embolized using microcoils, resulting in the disappearance of the perfusion in the arteriovenous fistula.
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Protein kinase C γ (PKCγ), a neuronal isoform present exclusively in the central nervous system, is most abundantly expressed in cerebellar Purkinje cells (PCs). Targeted deletion of PKCγ causes a climbing fiber synapse elimination in developing PCs and motor deficit. However, physiological roles of PKCγ in adult mouse PCs are little understood. In this study, we aimed to unravel the roles of PKCγ in mature mouse PCs by deleting PKCγ from adult mouse PCs of PKCγfl/fl mice via cerebellar injection of adeno-associated virus (AAV) vectors expressing Cre recombinase under the control of the PC-specific L7-6 promoter. Whole cell patch-clamp recording of PCs showed higher intrinsic excitability in PCs virally lacking PKCγ [PKCγ-conditional knockout (PKCγ-cKO) PCs] than in wild-type (WT) mouse PCs in the zebrin-negative module, but not in the zebrin-positive module. AAV-mediated PKCγ re-expression in PKCγ-deficient mouse PCs in the zebrin-negative module restored the enhanced intrinsic excitability to a level comparable to that of wild-type mouse PCs. In parallel with higher intrinsic excitability, we found larger hyperpolarization-activated cyclic nucleotide-gated (HCN) channel currents in PKCγ-cKO PCs located in the zebrin-negative module, compared with those in WT mouse PCs in the same region. However, pharmacological inhibition of the HCN currents did not restore the enhanced intrinsic excitability in PKCγ-cKO PCs in the zebrin-negative module. These results suggested that PKCγ suppresses the intrinsic excitability in zebrin-negative PCs, which is likely independent of the HCN current inhibition.
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The cortico-basal ganglia circuit mediates decision making. Here, we generated transgenic tools for adult zebrafish targeting specific subpopulations of the components of this circuit and utilized them to identify evolutionary homologs of the mammalian direct- and indirect-pathway striatal neurons, which respectively project to the homologs of the internal and external segment of the globus pallidus (dorsal entopeduncular nucleus [dEN] and lateral nucleus of the ventral telencephalic area [Vl]) as in mammals. Unlike in mammals, the Vl mainly projects to the dEN directly, not by way of the subthalamic nucleus. Further single-cell RNA sequencing analysis reveals two pallidal output pathways: a major shortcut pathway directly connecting the dEN with the pallium and the evolutionarily conserved closed loop by way of the thalamus. Our resources and circuit map provide the common basis for the functional study of the basal ganglia in a small and optically tractable zebrafish brain for the comprehensive mechanistic understanding of the cortico-basal ganglia circuit.
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Ganglios Basales , Pez Cebra , Animales , Pez Cebra/genética , Ganglios Basales/fisiología , Cuerpo Estriado , Globo Pálido/fisiología , Animales Modificados Genéticamente , Mamíferos , Vías Nerviosas/fisiologíaAsunto(s)
Apoyo Vital Cardíaco Avanzado , Aorta , Oclusión con Balón , Procedimientos Endovasculares , Exsanguinación , Humanos , Apoyo Vital Cardíaco Avanzado/instrumentación , Apoyo Vital Cardíaco Avanzado/métodos , Aorta/cirugía , Oclusión con Balón/instrumentación , Oclusión con Balón/métodos , Procedimientos Endovasculares/instrumentación , Procedimientos Endovasculares/métodos , Exsanguinación/cirugíaRESUMEN
How the activity of neurons gives rise to natural vision remains a matter of intense investigation. The mid-level visual areas along the ventral stream are selective to a common class of natural images-textures-but a circuit-level understanding of this selectivity and its link to perception remains unclear. We addressed these questions in mice, first showing that they can perceptually discriminate between textures and statistically simpler spectrally matched stimuli, and between texture types. Then, at the neural level, we found that the secondary visual area (LM) exhibited a higher degree of selectivity for textures compared to the primary visual area (V1). Furthermore, textures were represented in distinct neural activity subspaces whose relative distances were found to correlate with the statistical similarity of the images and the mice's ability to discriminate between them. Notably, these dependencies were more pronounced in LM, where the texture-related subspaces were smaller than in V1, resulting in superior stimulus decoding capabilities. Together, our results demonstrate texture vision in mice, finding a linking framework between stimulus statistics, neural representations, and perceptual sensitivity-a distinct hallmark of efficient coding computations.
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Corteza Visual , Vías Visuales , Animales , Ratones , Estimulación Luminosa/métodos , Vías Visuales/fisiología , Corteza Visual/fisiología , Neuronas/fisiología , Percepción Visual/fisiologíaRESUMEN
The production of cell-type- and age-specific genetically modified mice is a powerful approach for unraveling unknown gene functions. Here, we present a simple and timesaving method that enables adeno-associated virus (AAV)-mediated cell-type- and age-specific recombination in floxed mice. To achieve astrocyte-specific recombination in floxed Ai14 reporter mice, we intravenously injected blood-brain barrier-penetrating AAV-PHP.eB vectors expressing Cre recombinase (Cre) using the astrocyte-specific mouse glial fibrillary acidic protein (mGfaABC1D) promoter. However, we observed nonspecific neuron-predominant transduction despite the use of an astrocyte-specific promoter. We speculated that subtle but continuous Cre expression in nonastrocytic cells triggers recombination, and that excess production of Cre in astrocytes inhibits recombination by forming Cre-DNA aggregates. Here, we resolved this paradoxical event by dividing a single AAV into two mGfaABC1D-promoter-driven AAV vectors, one expressing codon-optimized flippase (FlpO) and another expressing flippase recognition target-flanked rapidly degrading Cre (dCre), together with switching the neuron-tropic PHP.eB capsid to astrocyte-tropic AAV-F. Moreover, we found that the FlpO-dCre system with a target cell-tropic capsid can also function in neuron-targeting recombination in floxed mice.
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Cardiovascular complications of cancer therapy are among the most important factors affecting cancer prognosis. Cisplatin-induced aortic thrombosis is rare but can be life-threatening in the event of peripheral embolism. In this report, we describe a case of superior mesenteric artery (SMA) embolism associated with cisplatin-induced aortic thrombosis. A 66-year-old male, diagnosed with esophageal cancer, initiated systemic chemotherapy with a regimen consisting of 5-fluorouracil and cisplatin, combined with radiotherapy. After 7 days of chemoradiotherapy, the patient developed a floating thrombus in the ascending aorta and an SMA embolism; chemoradiotherapy was then discontinued. Laparoscopy revealed an ischemic small intestine that required resection; intravenous unfractionated heparin was initiated 3 days after. Computed tomography showed disappearance of the floating aortic thrombus and reduce SMA thrombus size. Early detection of cisplatin-induced aortic thrombosis may prevent fatal outcomes in symptomatic peripheral embolisms, such as SMA embolism, considering anticoagulation, and discontinuation of cisplatin-based chemotherapy may cause resolution of thrombus events.
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Bifidobacterium animalis subsp. lactis GCL2505 (GCL2505) improves the intestinal microbiota and reduces human visceral fat. This randomized, double-blind, placebo-controlled, parallel-group study was conducted to examine the effects of inulin, a prebiotic dietary fiber, and GCL2505 on vascular endothelial function in healthy subjects (n = 60). The test drink contained 2.0 g/100 g inulin and 1.0 × 1010 colony-forming units/100 g GCL2505 and was consumed daily for 12 weeks. Flow-mediated dilation was set as the primary endpoint. Subgroup analysis of vascular endothelial function demonstrated a significant increase in the change of flow-mediated dilation (%) from weeks 0 to 12 in the GCL2505 and inulin group (n = 24) compared with the placebo group (n = 23), while an improving trend in low-density lipoprotein cholesterol and plasminogen activator inhibitor-1 were confirmed. Our results indicated that the test drink had a positive effect on vascular endothelial function and related blood parameters.
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Bifidobacterium , Probióticos , Humanos , Inulina/farmacología , Fibras de la Dieta , Prebióticos , Método Doble Ciego , Ingestión de AlimentosRESUMEN
In this report, we present a case of gastrointestinal bleeding due to splenic artery rupture, which required repeated transcatheter arterial embolization (TAE) within a short period of time. A 75-year-old man with pancreatic carcinoma was transported to our hospital with active hematemesis and vital signs consistent with shock. Contrast-enhanced computed tomography images showed a pancreatic tumor that had caused a pseudoaneurysm of the splenic artery to rupture. The pseudoaneurysm was embolized using only an N-butyl-2-cyanoacrylate (NBCA) and lipiodol mixture. However, hematemesis with signs of shock recurred 13 h later, and angiography showed rebleeding from the origin of the splenic artery. The splenic artery was subsequently embolized using an NBCA and lipiodol mixture. Repeated TAE finally controlled the hemorrhage; however, asymptomatic splenic infarction and hepatic infarction occurred due to nontarget embolization.
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Sleep is a crucial component of health, and insomnia is among the most common and vexing of life-habit-related disorders. While dietary sleep-support supplements can improve sleep, choosing an effective dietary supplement can be challenging for users due to the wide variety of options available and the varying effects experienced by different individuals. In this study, to identify new criteria for estimating the effects of dietary supplements, we examined the relationships among the dietary supplements, the pre-conditions (PCs; defined as the life habits and sleep conditions before supplementation), and the sleep problems of subjects before supplementation. An open, randomized, cross-over intervention trial enrolling 160 subjects was conducted to test the efficacy of each dietary supplement (Analysis 1) and the relationships among dietary supplements, the PCs, and sleep problems (Analysis 2). To this end, l-theanine (200 mg/day), γ-aminobutyric acid (GABA) (111.1 mg/day), Apocynum venetum leaf extract (AVLE) (50 mg/day), and l-serine (300 mg/day) were administered to subjects. Before the first intervention period, life habits and sleep conditions were surveyed to identify each subject's PCs. For each combination of supplements and sleep problems, PCs were compared between subjects whose sleep problems were improved and subjects whose sleep problems were not improved via supplementation. All the tested supplements were found to ameliorate sleep problems significantly (Analysis 1). In Analysis 2, the PCs specific to improved subjects were found to differ depending on the dietary supplements and sleep problems. In addition, subjects who consumed dairy products often showed improvement in their sleep problems with all the tested supplements. This study suggests the possibility of personalizing sleep-support supplementation based on personal life habits, sleep conditions, and sleep problems, in addition to the known efficacy of dietary supplements.
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Suplementos Dietéticos , Trastornos del Sueño-Vigilia , Humanos , Sueño , Encuestas y Cuestionarios , HábitosRESUMEN
BACKGROUND: The aim of this study was to evaluate the effect of caffeine therapy in preventing severe hyperkalemia in preterm infants. METHODS: We performed a single-center, retrospective study of preterm infants of 25-29 weeks' gestation admitted in our neonatal intensive care unit from January 2019-August 2020. We divided the infants into two groups: the control group (January 2019-November 2019) and the early caffeine group (December 2019-August 2020). RESULTS: We identified 33 infants (early caffeine, 15; control, 18). Baseline potassium levels were 5.3 and 4.8 mEq/L, respectively (p = 0.274). Severe hyperkalemia (K > 6.5 mEq/L) was observed in 0 (0%) and 7 (39%) (p = 0.009), in the early caffeine group and control group. The linear mixed-effect model confirmed the correlation between caffeine therapy and time from birth for the prediction of potassium levels (p < 0.001). While the potassium levels increased from baseline potassium levels at birth by 0.869 mEq/L at 12 h of birth, 0.884 mEq/L at 18 h of birth, and 0.641 mEq/L at 24 h of birth in the control group, the potassium levels were similar to the baseline levels at 12, 18, and 24 h of life in the early caffeine group. Among the clinical features, only early caffeine therapy was negatively associated with the incidence of hyperkalemia within 72 h of life. CONCLUSION: Early caffeine therapy within a few hours of life effectively prevents the incidence of severe hyperkalemia within the first 72 h of life in preterm infants of 25-29 weeks' gestation. Prophylactic early caffeine therapy can, therefore, be considered in high-risk, preterm infants.
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Hiperpotasemia , Enfermedades del Prematuro , Lactante , Recién Nacido , Humanos , Recien Nacido Prematuro , Hiperpotasemia/prevención & control , Hiperpotasemia/epidemiología , Cafeína/uso terapéutico , Estudios Retrospectivos , Enfermedades del Prematuro/epidemiología , PotasioRESUMEN
Choice information appears in multi-area brain networks mixed with sensory, motor, and cognitive variables. In the posterior cortex-traditionally implicated in decision computations-the presence, strength, and area specificity of choice signals are highly variable, limiting a cohesive understanding of their computational significance. Examining the mesoscale activity in the mouse posterior cortex during a visual task, we found that choice signals defined a decision variable in a low-dimensional embedding space with a prominent contribution along the ventral visual stream. Their subspace was near-orthogonal to concurrently represented sensory and motor-related activations, with modulations by task difficulty and by the animals' attention state. A recurrent neural network trained with animals' choices revealed an equivalent decision variable whose context-dependent dynamics agreed with that of the neural data. Our results demonstrated an independent, multi-area decision variable in the posterior cortex, controlled by task features and cognitive demands, possibly linked to contextual inference computations in dynamic animal-environment interactions.
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Corteza Cerebral , Toma de Decisiones , Animales , Ratones , Redes Neurales de la Computación , Conducta de ElecciónRESUMEN
BACKGROUND & AIMS: We investigate interrelationships between gut microbes, metabolites, and cytokines that characterize COVID-19 and its complications, and we validate the results with follow-up, the Japanese 4D (Disease, Drug, Diet, Daily Life) microbiome cohort, and non-Japanese data sets. METHODS: We performed shotgun metagenomic sequencing and metabolomics on stools and cytokine measurements on plasma from 112 hospitalized patients with SARS-CoV-2 infection and 112 non-COVID-19 control individuals matched by important confounders. RESULTS: Multiple correlations were found between COVID-19-related microbes (eg, oral microbes and short-chain fatty acid producers) and gut metabolites (eg, branched-chain and aromatic amino acids, short-chain fatty acids, carbohydrates, neurotransmitters, and vitamin B6). Both were also linked to inflammatory cytokine dynamics (eg, interferon γ, interferon λ3, interleukin 6, CXCL-9, and CXCL-10). Such interrelationships were detected highly in severe disease and pneumonia; moderately in the high D-dimer level, kidney dysfunction, and liver dysfunction groups; but rarely in the diarrhea group. We confirmed concordances of altered metabolites (eg, branched-chain amino acids, spermidine, putrescine, and vitamin B6) in COVID-19 with their corresponding microbial functional genes. Results in microbial and metabolomic alterations with severe disease from the cross-sectional data set were partly concordant with those from the follow-up data set. Microbial signatures for COVID-19 were distinct from diabetes, inflammatory bowel disease, and proton-pump inhibitors but overlapping for rheumatoid arthritis. Random forest classifier models using microbiomes can highly predict COVID-19 and severe disease. The microbial signatures for COVID-19 showed moderate concordance between Hong Kong and Japan. CONCLUSIONS: Multiomics analysis revealed multiple gut microbe-metabolite-cytokine interrelationships in COVID-19 and COVID-19related complications but few in gastrointestinal complications, suggesting microbiota-mediated immune responses distinct between the organ sites. Our results underscore the existence of a gut-lung axis in COVID-19.
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COVID-19 , Microbioma Gastrointestinal , Humanos , Microbioma Gastrointestinal/genética , Estudios Transversales , SARS-CoV-2 , Heces/química , Inmunidad , Citocinas , Vitamina B 6/análisisRESUMEN
Pelvic fractures are common in cases of blunt trauma, which is strongly associated with mortality. Transcatheter arterial embolization is a fundamental treatment strategy for fatal arterial injuries caused by blunt pelvic trauma. However, vascular injuries due to blunt pelvic trauma can show various imaging findings other than arterial hemorrhage. We present a pictorial review of common and uncommon vascular injuries, including active arterial bleeding, pseudoaneurysm, arteriovenous fistula, arterial occlusion, vasospasm, and active venous bleeding. Knowledge of these vascular injuries can help clinicians select the appropriate therapeutic strategy and thus save lives.
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Fístula Arteriovenosa , Embolización Terapéutica , Lesiones del Sistema Vascular , Heridas no Penetrantes , Humanos , Lesiones del Sistema Vascular/diagnóstico por imagen , Lesiones del Sistema Vascular/etiología , Lesiones del Sistema Vascular/terapia , Pelvis/diagnóstico por imagen , Hemorragia/diagnóstico por imagen , Hemorragia/etiología , Hemorragia/terapia , Embolización Terapéutica/métodos , Fístula Arteriovenosa/diagnóstico por imagen , Fístula Arteriovenosa/etiología , Fístula Arteriovenosa/terapia , Heridas no Penetrantes/complicaciones , Heridas no Penetrantes/diagnóstico por imagen , Heridas no Penetrantes/terapiaRESUMEN
We investigated the feasibility of a new deep-learning (DL)-based lung analysis method for the evaluation of interstitial lung disease (ILD) by comparing it with evaluation using the traditional computer-aided diagnosis (CAD) system and patients' clinical outcomes. We prospectively included 104 patients (84 with and 20 without ILD). An expert radiologist defined regions of interest in the typical areas of normal, ground-glass opacity, consolidation, consolidation with fibrosis (traction bronchiectasis), honeycombing, reticulation, traction bronchiectasis, and emphysema, and compared them with the CAD and DL-based analysis results. Next, we measured the extent of ILD lesions with the CAD and DL-based analysis and compared them. Finally, we compared the lesion extent on computed tomography (CT) images, as measured with the DL-based analysis, with pulmonary function tests results and patients' overall survival. Pearson's correlation analysis revealed a significant correlation between DL-based analysis and CAD results. Forced vital capacity was significantly correlated with DL-based analysis (r = 0.789, p < 0.001 for normal lung volume and r = −0.316, p = 0.001 for consolidation with fibrosis volume). Consolidation with fibrosis measured using DL-based analysis was independently associated with poor survival. The lesion extent measured using DL-based analysis showed a negative correlation with the pulmonary function test results and prognosis.
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BACKGROUND & AIMS: Medication is a major determinant of human gut microbiome structure, and its overuse increases the risks of morbidity and mortality. However, effects of certain commonly prescribed drugs and multiple medications on the gut microbiome are still underinvestigated. METHODS: We performed shotgun metagenomic analysis of fecal samples from 4198 individuals in the Japanese 4D (Disease, Drug, Diet, Daily life) microbiome project. A total of 759 drugs were profiled, and other metadata, such as anthropometrics, lifestyles, diets, physical activities, and diseases, were prospectively collected. Second fecal samples were collected from 243 individuals to assess the effects of drug initiation and discontinuation on the microbiome. RESULTS: We found that numerous drugs across different treatment categories influence the microbiome; more than 70% of the drugs we profiled had not been examined before. Individuals exposed to multiple drugs, polypharmacy, showed distinct gut microbiome structures harboring significantly more abundant upper gastrointestinal species and several nosocomial pathobionts due to additive drug effects. Polypharmacy was also associated with microbial functions, including the reduction of short-chain fatty acid metabolism and increased bacterial stress responses. Even nonantibiotic drugs were significantly correlated with an increased antimicrobial resistance potential through polypharmacy. Notably, a 2-time points dataset revealed the alteration and recovery of the microbiome in response to drug initiation and cessation, corroborating the observed drug-microbe associations in the cross-sectional cohort. CONCLUSION: Our large-scale metagenomics unravels extensive and disruptive impacts of individual and multiple drug exposures on the human gut microbiome, providing a drug-microbe catalog as a basis for a deeper understanding of the role of the microbiome in drug efficacy and toxicity.
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Antiinfecciosos , Microbioma Gastrointestinal , Microbiota , Estudios Transversales , Ácidos Grasos Volátiles/farmacología , Heces/microbiología , Microbioma Gastrointestinal/fisiología , Humanos , MetagenómicaRESUMEN
BACKGROUND & AIMS: To identify gut and oral metagenomic signatures that accurately predict pancreatic ductal carcinoma (PDAC) and to validate these signatures in independent cohorts. METHODS: We conducted a multinational study and performed shotgun metagenomic analysis of fecal and salivary samples collected from patients with treatment-naïve PDAC and non-PDAC controls in Japan, Spain, and Germany. Taxonomic and functional profiles of the microbiomes were characterized, and metagenomic classifiers to predict PDAC were constructed and validated in external datasets. RESULTS: Comparative metagenomics revealed dysbiosis of both the gut and oral microbiomes and identified 30 gut and 18 oral species significantly associated with PDAC in the Japanese cohort. These microbial signatures achieved high area under the curve values of 0.78 to 0.82. The prediction model trained on the Japanese gut microbiome also had high predictive ability in Spanish and German cohorts, with respective area under the curve values of 0.74 and 0.83, validating its high confidence and versatility for PDAC prediction. Significant enrichments of Streptococcus and Veillonella spp and a depletion of Faecalibacterium prausnitzii were common gut signatures for PDAC in all the 3 cohorts. Prospective follow-up data revealed that patients with certain gut and oral microbial species were at higher risk of PDAC-related mortality. Finally, 58 bacteriophages that could infect microbial species consistently enriched in patients with PDAC across the 3 countries were identified. CONCLUSIONS: Metagenomics targeting the gut and oral microbiomes can provide a powerful source of biomarkers for identifying individuals with PDAC and their prognoses. The identification of shared gut microbial signatures for PDAC in Asian and European cohorts indicates the presence of robust and global gut microbial biomarkers.
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Metagenómica , Neoplasias Pancreáticas , Disbiosis/microbiología , Heces/microbiología , Humanos , Metagenoma , Neoplasias Pancreáticas/diagnóstico , Neoplasias Pancreáticas/genética , Estudios Prospectivos , Neoplasias PancreáticasRESUMEN
BACKGROUND: Non-alcoholic liver disease (NAFLD) is the hepatic manifestation of metabolic syndrome, and it can progress to non-alcoholic steatohepatitis (NASH). Alterations in the gut microbiome have been implicated in the development of NAFLD/NASH, although the underlying mechanisms remain unclear. RESULTS: We found that the consumption of the prebiotic inulin markedly ameliorated the phenotype of NAFLD/NASH, including hepatic steatosis and fibrosis, in mice. Inulin consumption resulted in global changes in the gut microbiome, including concomitant enrichment of the genera Bacteroides and Blautia, and increased concentrations of short-chain fatty acids, particularly acetate, in the gut lumen and portal blood. The consumption of acetate-releasing resistant starch protected against NAFLD development. Colonisation by Bacteroides acidifaciens and Blautia producta in germ-free mice resulted in synergetic effects on acetate production from inulin. Furthermore, the absence of free fatty acid receptor 2 (FFAR2), an acetate receptor, abolished the protective effect of inulin, as indicated by the more severe liver hypertrophy, hypercholesterolaemia and inflammation. These effects can be attributed to an exacerbation of insulin resistance in the liver, but not in muscle or adipose tissue. CONCLUSION: These findings demonstrated that the commensal microbiome-acetate-FFAR2 molecular circuit improves insulin sensitivity in the liver and prevents the development of NAFLD/NASH. Video abstract.
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Enfermedad del Hígado Graso no Alcohólico , Acetatos , Animales , Bacteroides , Clostridiales , Ratones , Receptores Acoplados a Proteínas G/genéticaRESUMEN
How liver tolerance is disrupted in immune-mediated liver injury is currently unclear. There is also insufficient information available regarding susceptibility, precipitation, escalation, and perpetuation of autoimmune hepatitis. To explore how dietary fiber influences hepatic damage, we applied the concanavalin A (ConA)-induced acute immune-mediated liver injury model in mice fed a diet supplemented with 6.8% inulin, a water-soluble fermentable fiber. Twelve hours after ConA administration, inulin-supplemented diet-fed mice demonstrated significantly alleviated hepatic damage histologically and serologically, with down-regulation of hepatic interferon-γ and tumor necrosis factor and reduced myeloperoxidase (MPO)-producing neutrophil infiltration. Preconditioning with an inulin-supplemented diet for 2 weeks significantly reduced hepatic adenosine triphosphate (ATP) content; suramin, a purinergic P2 receptor antagonist, abolished the protective effect. Of note, the portal plasma derived from mice fed the inulin-supplemented diet significantly alleviated ConA-induced immune-mediated liver injury. Mechanistically, increased portal short-chain fatty acid (SCFA) levels, such as those of acetate and butyrate, by inulin supplementation leads to up-regulation of hepatic γ-type peroxisome proliferator-activated receptor (Pparg) and uncoupling protein 2 (Ucp2), which uncouples mitochondrial ATP synthesis downstream of PPARγ. Pparg down-regulating small interfering RNA cancelled the protective effect of inulin supplementation against MPO-producing neutrophil infiltration and the subsequent immune-mediated liver injury, suggesting that the SCFA-PPARγ-UCP2 axis plays a key role in the protective effect by inulin supplementation. Moreover, significant changes in the gut microbiota, including increased operational taxonomic units in genera Akkermansia and Allobaculum, also characterized the protective effect of the inulin-supplemented diet. Conclusion: There is a possible unraveled etiopathophysiological link between the maintenance of liver tolerance and dietary fiber. The SCFA-PPARγ-UCP2 axis may provide therapeutic targets for immune-mediated liver injury in the future.
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During perceptual decision-making, the brain encodes the upcoming decision and the stimulus information in a mixed representation. Paradigms suitable for studying decision computations in isolation rely on stimulus comparisons, with choices depending on relative rather than absolute properties of the stimuli. The adoption of tasks requiring relative perceptual judgments in mice would be advantageous in view of the powerful tools available for the dissection of brain circuits. However, whether and how mice can perform a relative visual discrimination task has not yet been fully established. Here, we show that mice can solve a complex orientation discrimination task in which the choices are decoupled from the orientation of individual stimuli. Moreover, we demonstrate a typical discrimination acuity of 9°, challenging the common belief that mice are poor visual discriminators. We reached these conclusions by introducing a probabilistic choice model that explained behavioral strategies in 40 mice and demonstrated that the circularity of the stimulus space is an additional source of choice variability for trials with fixed difficulty. Furthermore, history biases in the model changed with task engagement, demonstrating behavioral sensitivity to the availability of cognitive resources. In conclusion, our results reveal that mice adopt a diverse set of strategies in a task that decouples decision-relevant information from stimulus-specific information, thus demonstrating their usefulness as an animal model for studying neural representations of relative categories in perceptual decision-making research.