Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 174
Filtrar
Más filtros

Banco de datos
Tipo del documento
Intervalo de año de publicación
1.
Proc Natl Acad Sci U S A ; 120(20): e2302937120, 2023 05 16.
Artículo en Inglés | MEDLINE | ID: mdl-37155852

RESUMEN

Implantation is the first direct encounter between the embryo and uterus during pregnancy, and Hbegf is the earliest known molecular signaling for embryo-uterine crosstalk during implantation. The downstream effectors of heparin-binding EGF (HB-EGF) in implantation remain elusive due to the complexity of EGF receptor family. This study shows that the formation of implantation chamber (crypt) triggered by HB-EGF is disrupted by uterine deletion of Vangl2, a key planar cell polarity component (PCP). We found that HB-EGF binds to ERBB2 and ERBB3 to recruit VANGL2 for tyrosine phosphorylation. Using in vivo models, we show that uterine VAGL2 tyrosine phosphorylation is suppressed in Erbb2/Erbb3 double conditional knockout mice. In this context, severe implantation defects in these mice lend support to the critical role of HB-EGF-ERBB2/3-VANGL2 in establishing a two-way dialogue between the blastocyst and uterus. In addition, the result addresses an outstanding question how VANGL2 is activated during implantation. Taken together, these observations reveal that HB-EGF regulates the implantation process by influencing uterine epithelial cell polarity comprising VANGL2.


Asunto(s)
Polaridad Celular , Implantación del Embrión , Animales , Femenino , Ratones , Embarazo , Polaridad Celular/fisiología , Implantación del Embrión/fisiología , Factor de Crecimiento Similar a EGF de Unión a Heparina/genética , Factor de Crecimiento Similar a EGF de Unión a Heparina/metabolismo , Ratones Noqueados , Transducción de Señal , Tirosina
2.
Proc Natl Acad Sci U S A ; 120(51): e2310053120, 2023 Dec 19.
Artículo en Inglés | MEDLINE | ID: mdl-38096412

RESUMEN

Systemic infections can yield distinct outcomes in different tissues. In mice, intravenous inoculation of Escherichia coli leads to bacterial replication within liver abscesses, while other organs such as the spleen clear the pathogen. Abscesses are macroscopic necrotic regions that comprise the vast majority of the bacterial burden in the animal, yet little is known about the processes underlying their formation. Here, we characterize E. coli liver abscesses and identify host determinants of abscess susceptibility. Spatial transcriptomics revealed that liver abscesses are associated with heterogenous immune cell clusters comprised of macrophages, neutrophils, dendritic cells, innate lymphoid cells, and T-cells that surround necrotic regions of the liver. Abscess susceptibility is heightened in the C57BL lineage, particularly in C57BL/6N females. Backcross analyses demonstrated that abscess susceptibility is a polygenic trait inherited in a sex-dependent manner without direct linkage to sex chromosomes. As early as 1 d post infection, the magnitude of E. coli replication in the liver distinguishes abscess-susceptible and abscess-resistant strains of mice, suggesting that the immune pathways that regulate abscess formation are induced within hours. We characterized the early hepatic response with single-cell RNA sequencing and found that mice with reduced activation of early inflammatory responses, such as those lacking the LPS receptor TLR4 (Toll-like receptor 4), are resistant to abscess formation. Experiments with barcoded E. coli revealed that TLR4 mediates a tradeoff between abscess formation and bacterial clearance. Together, our findings define hallmarks of E. coli liver abscess formation and suggest that hyperactivation of the hepatic innate immune response drives liver abscess susceptibility.


Asunto(s)
Infecciones por Escherichia coli , Absceso Hepático , Femenino , Ratones , Animales , Escherichia coli/metabolismo , Receptor Toll-Like 4/metabolismo , Inmunidad Innata/genética , Ratones Endogámicos C57BL , Linfocitos/metabolismo , Absceso Hepático/genética
3.
PLoS Genet ; 19(10): e1010997, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37871105

RESUMEN

Diet-related metabolic syndrome is the largest contributor to adverse health in the United States. However, the study of gene-environment interactions and their epigenomic and transcriptomic integration is complicated by the lack of environmental and genetic control in humans that is possible in mouse models. Here we exposed three mouse strains, C57BL/6J (BL6), A/J, and NOD/ShiLtJ (NOD), to a high-fat, high-carbohydrate diet, leading to varying degrees of metabolic syndrome. We then performed transcriptomic and genome-wide DNA methylation analyses for each strain and found overlapping but also highly divergent changes in gene expression and methylation upstream of the discordant metabolic phenotypes. Strain-specific pathway analysis of dietary effects revealed a dysregulation of cholesterol biosynthesis common to all three strains but distinct regulatory networks driving this dysregulation. This suggests a strategy for strain-specific targeted pharmacologic intervention of these upstream regulators informed by epigenetic and transcriptional regulation. As a pilot study, we administered the drug GW4064 to target one of these genotype-dependent networks, the farnesoid X receptor pathway, and found that GW4064 exerts strain-specific protection against dietary effects in BL6, as predicted by our transcriptomic analysis. Furthermore, GW4064 treatment induced inflammatory-related gene expression changes in NOD, indicating a strain-specific effect in its associated toxicities as well as its therapeutic efficacy. This pilot study demonstrates the potential efficacy of precision therapeutics for genotype-informed dietary metabolic intervention and a mouse platform for guiding this approach.


Asunto(s)
Síndrome Metabólico , Humanos , Ratones , Animales , Síndrome Metabólico/tratamiento farmacológico , Síndrome Metabólico/genética , Síndrome Metabólico/metabolismo , Epigenómica , Proyectos Piloto , Hígado/metabolismo , Ratones Endogámicos C57BL , Ratones Endogámicos NOD , Dieta Alta en Grasa/efectos adversos , Epigénesis Genética
4.
PLoS Genet ; 18(4): e1010075, 2022 04.
Artículo en Inglés | MEDLINE | ID: mdl-35417454

RESUMEN

Salmonella infections typically cause self-limiting gastroenteritis, but in some individuals these bacteria can spread systemically and cause disseminated disease. Salmonella Typhimurium (STm), which causes severe systemic disease in most inbred mice, has been used as a model for disseminated disease. To screen for new infection phenotypes across a range of host genetics, we orally infected 32 Collaborative Cross (CC) mouse strains with STm and monitored their disease progression for seven days by telemetry. Our data revealed a broad range of phenotypes across CC strains in many parameters including survival, bacterial colonization, tissue damage, complete blood counts (CBC), and serum cytokines. Eighteen CC strains survived to day 7, while fourteen susceptible strains succumbed to infection before day 7. Several CC strains had sex differences in survival and colonization. Surviving strains had lower pre-infection baseline temperatures and were less active during their daily active period. Core body temperature disruptions were detected earlier after STm infection than activity disruptions, making temperature a better detector of illness. All CC strains had STm in spleen and liver, but susceptible strains were more highly colonized. Tissue damage was weakly negatively correlated to survival. We identified loci associated with survival on Chromosomes (Chr) 1, 2, 4, 7. Polymorphisms in Ncf2 and Slc11a1, known to reduce survival in mice after STm infections, are located in the Chr 1 interval, and the Chr 7 association overlaps with a previously identified QTL peak called Ses2. We identified two new genetic regions on Chr 2 and 4 associated with susceptibility to STm infection. Our data reveal the diversity of responses to STm infection across a range of host genetics and identified new candidate regions for survival of STm infection.


Asunto(s)
Salmonelosis Animal , Infecciones por Salmonella , Salmonella enterica , Animales , Susceptibilidad a Enfermedades , Femenino , Antecedentes Genéticos , Masculino , Ratones , Fenotipo , Infecciones por Salmonella/genética , Salmonelosis Animal/microbiología , Salmonella typhimurium/genética , Serogrupo
5.
Proc Natl Acad Sci U S A ; 119(46): e2213308119, 2022 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-36346842

RESUMEN

Invasive rodents are a major cause of environmental damage and biodiversity loss, particularly on islands. Unlike insects, genetic biocontrol strategies including population-suppressing gene drives with biased inheritance have not been developed in mice. Here, we demonstrate a gene drive strategy (tCRISPR) that leverages super-Mendelian transmission of the t haplotype to spread inactivating mutations in a haplosufficient female fertility gene (Prl). Using spatially explicit individual-based in silico modeling, we show that tCRISPR can eradicate island populations under a range of realistic field-based parameter values. We also engineer transgenic tCRISPR mice that, crucially, exhibit biased transmission of the modified t haplotype and Prl mutations at levels our modeling predicts would be sufficient for eradication. This is an example of a feasible gene drive system for invasive alien rodent population control.


Asunto(s)
Biodiversidad , Tecnología de Genética Dirigida , Ratones , Femenino , Animales , Roedores , Genética de Población , Repeticiones Palindrómicas Cortas Agrupadas y Regularmente Espaciadas
6.
PLoS Genet ; 17(11): e1009931, 2021 11.
Artículo en Inglés | MEDLINE | ID: mdl-34843459

RESUMEN

ERBB3 has gained attention as a potential therapeutic target to treat colorectal and other types of cancers. To confirm a previous study showing intestinal polyps are dependent upon ERBB3, we generated an intestinal epithelia-specific ERBB3 deletion in C57BL/6-ApcMin/+ mice. Contrary to the previous report showing a significant reduction in intestinal polyps with ablation of ERBB3 on a B6;129 mixed genetic background, we observed a significant increase in polyp number with ablation of ERBB3 on C57BL/6J compared to control littermates. We confirmed the genetic background dependency of ERBB3 by also analyzing polyp development on B6129 hybrid and B6;129 advanced intercross mixed genetic backgrounds, which showed that ERBB3 deficiency only reduced polyp number on the mixed background as previously reported. Increased polyp number with ablation of ERBB3 was also observed in C57BL/6J mice treated with azoxymethane showing the effect is model independent. Polyps forming in absence of ERBB3 were generally smaller than those forming in control mice, albeit the effect was greatest in genetic backgrounds with reduced polyp numbers. The mechanism for differential polyp number in the absence of ERBB3 was through altered proliferation. Backgrounds with increased polyp number with loss of ERBB3 showed an increase in cell proliferation even in non-tumor epithelia, while backgrounds showing reduced polyp number with loss of ERBB3 showed reduced cellular proliferation. Increase polyp number caused by loss of ERBB3 was mediated by increased epidermal growth factor receptor (EGFR) expression, which was confirmed by deletion of Egfr. Taken together, this study raises substantial implications on the use of ERBB3 inhibitors against colorectal cancer. The prediction is that some patients may have increased progression with ERBB3 inhibitor therapy, which is consistent with observations reported for ERBB3 inhibitor clinical trials.


Asunto(s)
Pólipos del Colon/genética , Neoplasias Colorrectales/genética , Receptores ErbB/genética , Pólipos Intestinales/genética , Receptor ErbB-3/genética , Proteína de la Poliposis Adenomatosa del Colon/genética , Animales , Proliferación Celular/genética , Colon/metabolismo , Colon/patología , Pólipos del Colon/patología , Pólipos del Colon/terapia , Neoplasias Colorrectales/patología , Neoplasias Colorrectales/terapia , Modelos Animales de Enfermedad , Regulación Neoplásica de la Expresión Génica/genética , Silenciador del Gen , Humanos , Mucosa Intestinal/metabolismo , Mucosa Intestinal/patología , Pólipos Intestinales/patología , Pólipos Intestinales/terapia , Ratones , Receptor ErbB-3/antagonistas & inhibidores
7.
Stem Cells ; 40(3): 273-289, 2022 03 31.
Artículo en Inglés | MEDLINE | ID: mdl-35356986

RESUMEN

Insulin-like growth factor I (IGF-1) has been implicated in breast cancer due to its mitogenic and anti-apoptotic effects. Despite substantial research on the role of IGF-1 in tumor progression, the relationship of IGF-1 to tissue stem cells, particularly in mammary tissue, and the resulting tumor susceptibility has not been elucidated. Previous studies with the BK5.IGF-1 transgenic (Tg) mouse model reveals that IGF-1 does not act as a classical, post-carcinogen tumor promoter in the mammary gland. Pre-pubertal Tg mammary glands display increased numbers and enlarged sizes of terminal end buds, a niche for mammary stem cells (MaSCs). Here we show that MaSCs from both wild-type (WT) and Tg mice expressed IGF-1R and that overexpression of Tg IGF-1 increased numbers of MaSCs by undergoing symmetric division, resulting in an expansion of the MaSC and luminal progenitor (LP) compartments in pre-pubertal female mice. This expansion was maintained post-pubertally and validated by mammosphere assays in vitro and transplantation assays in vivo. The addition of recombinant IGF-1 promoted, and IGF-1R downstream inhibitors decreased mammosphere formation. Single-cell transcriptomic profiles generated from 2 related platforms reveal that IGF-1 stimulated quiescent MaSCs to enter the cell cycle and increased their expression of genes involved in proliferation, plasticity, tumorigenesis, invasion, and metastasis. This study identifies a novel, pro-tumorigenic mechanism, where IGF-1 increases the number of transformation-susceptible carcinogen targets during the early stages of mammary tissue development, and "primes" their gene expression profiles for transformation.


Asunto(s)
Factor I del Crecimiento Similar a la Insulina , Glándulas Mamarias Animales , Animales , Proliferación Celular , Femenino , Humanos , Factor I del Crecimiento Similar a la Insulina/metabolismo , Ratones , Ratones Transgénicos , Células Madre/metabolismo
8.
EMBO Rep ; 22(6): e51913, 2021 06 04.
Artículo en Inglés | MEDLINE | ID: mdl-33890711

RESUMEN

The N-Myc Downstream-Regulated Gene 4 (NDRG4), a prominent biomarker for colorectal cancer (CRC), is specifically expressed by enteric neurons. Considering that nerves are important members of the tumor microenvironment, we here establish different Ndrg4 knockout (Ndrg4-/- ) CRC models and an indirect co-culture of primary enteric nervous system (ENS) cells and intestinal organoids to identify whether the ENS, via NDRG4, affects intestinal tumorigenesis. Linking immunostainings and gastrointestinal motility (GI) assays, we show that the absence of Ndrg4 does not trigger any functional or morphological GI abnormalities. However, combining in vivo, in vitro, and quantitative proteomics data, we uncover that Ndrg4 knockdown is associated with enlarged intestinal adenoma development and that organoid growth is boosted by the Ndrg4-/- ENS cell secretome, which is enriched for Nidogen-1 (Nid1) and Fibulin-2 (Fbln2). Moreover, NID1 and FBLN2 are expressed in enteric neurons, enhance migration capacities of CRC cells, and are enriched in human CRC secretomes. Hence, we provide evidence that the ENS, via loss of Ndrg4, is involved in colorectal pathogenesis and that ENS-derived Nidogen-1 and Fibulin-2 enhance colorectal carcinogenesis.


Asunto(s)
Neoplasias Colorrectales , Sistema Nervioso Entérico , Proteínas de Unión al Calcio , Neoplasias Colorrectales/genética , Proteínas de la Matriz Extracelular , Humanos , Glicoproteínas de Membrana , Proteínas Musculares , Proteínas del Tejido Nervioso/genética , Neuronas , Microambiente Tumoral
9.
Int J Mol Sci ; 24(3)2023 Feb 02.
Artículo en Inglés | MEDLINE | ID: mdl-36769167

RESUMEN

Neurological dysfunction following viral infection varies among individuals, largely due to differences in their genetic backgrounds. Gait patterns, which can be evaluated using measures of coordination, balance, posture, muscle function, step-to-step variability, and other factors, are also influenced by genetic background. Accordingly, to some extent gait can be characteristic of an individual, even prior to changes in neurological function. Because neuromuscular aspects of gait are under a certain degree of genetic control, the hypothesis tested was that gait parameters could be predictive of neuromuscular dysfunction following viral infection. The Collaborative Cross (CC) mouse resource was utilized to model genetically diverse populations and the DigiGait treadmill system used to provide quantitative and objective measurements of 131 gait parameters in 142 mice from 23 CC and SJL/J strains. DigiGait measurements were taken prior to infection with the neurotropic virus Theiler's Murine Encephalomyelitis Virus (TMEV). Neurological phenotypes were recorded over 90 days post-infection (d.p.i.), and the cumulative frequency of the observation of these phenotypes was statistically associated with discrete baseline DigiGait measurements. These associations represented spatial and postural aspects of gait influenced by the 90 d.p.i. phenotype score. Furthermore, associations were found between these gait parameters with sex and outcomes considered to show resistance, resilience, or susceptibility to severe neurological symptoms after long-term infection. For example, higher pre-infection measurement values for the Paw Drag parameter corresponded with greater disease severity at 90 d.p.i. Quantitative trait loci significantly associated with these DigiGait parameters revealed potential relationships between 28 differentially expressed genes (DEGs) and different aspects of gait influenced by viral infection. Thus, these potential candidate genes and genetic variations may be predictive of long-term neurological dysfunction. Overall, these findings demonstrate the predictive/prognostic value of quantitative and objective pre-infection DigiGait measurements for viral-induced neuromuscular dysfunction.


Asunto(s)
Theilovirus , Virosis , Ratones , Animales , Virosis/genética , Ratones Endogámicos , Sitios de Carácter Cuantitativo , Marcha
10.
Heredity (Edinb) ; 129(3): 183-194, 2022 09.
Artículo en Inglés | MEDLINE | ID: mdl-35764696

RESUMEN

House mice (Mus musculus) have spread globally as a result of their commensal relationship with humans. In the form of laboratory strains, both inbred and outbred, they are also among the most widely used model organisms in biomedical research. Although the general outlines of house mouse dispersal and population structure are well known, details have been obscured by either limited sample size or small numbers of markers. Here we examine ancestry, population structure, and inbreeding using SNP microarray genotypes in a cohort of 814 wild mice spanning five continents and all major subspecies of Mus, with a focus on M. m. domesticus. We find that the major axis of genetic variation in M. m. domesticus is a south-to-north gradient within Europe and the Mediterranean. The dominant ancestry component in North America, Australia, New Zealand, and various small offshore islands are of northern European origin. Next we show that inbreeding is surprisingly pervasive and highly variable, even between nearby populations. By inspecting the length distribution of homozygous segments in individual genomes, we find that inbreeding in commensal populations is mostly due to consanguinity. Our results offer new insight into the natural history of an important model organism for medicine and evolutionary biology.


Asunto(s)
Genoma , Endogamia , Animales , Evolución Biológica , Europa (Continente) , Humanos , Ratones , Nueva Zelanda
11.
Int J Mol Sci ; 23(18)2022 Sep 09.
Artículo en Inglés | MEDLINE | ID: mdl-36142395

RESUMEN

A wide range of viruses cause neurological manifestations in their hosts. Infection by neurotropic viruses as well as the resulting immune response can irreversibly disrupt the complex structural and functional architecture of the brain, depending in part on host genetic background. The interaction between host genetic background, neurological response to viral infection, and subsequent clinical manifestations remains poorly understood. In the present study, we used the genetically diverse Collaborative Cross (CC) mouse resource to better understand how differences in genetic background drive clinical signs and neuropathological manifestations of acute Theiler's murine encephalomyelitis virus (TMEV) infection. For the first time, we characterized variations of TMEV viral tropism and load based on host genetic background, and correlated viral load with microglial/macrophage activation. For five CC strains (CC002, CC023, CC027, CC057, and CC078) infected with TMEV, we compared clinical signs, lesion distribution, microglial/macrophage response, expression, and distribution of TMEV mRNA, and identified genetic loci relevant to the early acute (4 days post-infection [dpi]) and late acute (14 dpi) timepoints. We examined brain pathology to determine possible causes of strain-specific differences in clinical signs, and found that fields CA1 and CA2 of the hippocampal formation were especially targeted by TMEV across all strains. Using Iba-1 immunolabeling, we identified and characterized strain- and timepoint-specific variation in microglial/macrophage reactivity in the hippocampal formation. Because viral clearance can influence disease outcome, we used RNA in situ hybridization to quantify viral load and TMEV mRNA distribution at both timepoints. TMEV mRNA expression was broadly distributed in the hippocampal formation at 4 dpi in all strains but varied between radiating and clustered distribution depending on the CC strain. We found a positive correlation between microglial/macrophage reactivity and TMEV mRNA expression at 4 dpi. At 14 dpi, we observed a dramatic reduction in TMEV mRNA expression, and localization to the medial portion of field CA1 and field CA2. To better understand how host genetic background can influence pathological outcomes, we identified quantitative trait loci associated with frequency of lesions in a particular brain region and with microglial/macrophage reactivity. These QTL were located near several loci of interest: lysosomal trafficking regulator (Lyst) and nidogen 1 (Nid1), and transmembrane protein 106 B (Tmem106b). Together, these results provide a novel understanding about the influences of genetic variation on the acute neuropathological and immunopathological environment and viral load, which collectively lead to variable disease outcomes. Our findings reveal possible avenues for future investigation which may lead to more effective intervention strategies and treatment regimens.


Asunto(s)
Theilovirus , Animales , Antecedentes Genéticos , Ratones , Enfermedades Neuroinflamatorias , ARN , ARN Mensajero , Theilovirus/genética
12.
Infect Immun ; 89(7): e0004821, 2021 06 16.
Artículo en Inglés | MEDLINE | ID: mdl-33875475

RESUMEN

The spirochetal bacterium Borrelia recurrentis causes louse-borne relapsing fever (LBRF). B. recurrentis is unique because, as opposed to other Borrelia spirochetes, this strictly human pathogen is transmitted by lice. Despite the high mortality and historically proven epidemic potential and current outbreaks in African countries and Western Europe, research on LBRF has been obstructed by the lack of suitable animal models. The previously used grivet monkey model is associated with ethical concerns, among other issues. An existing immunodeficient mouse model does not limit bacteremia due to its impaired immune system. In this study, we used genetically diverse Collaborative Cross (CC) lines to develop the first LBRF immunocompetent mouse model. Out of 12 CC lines tested, CC046 mice consistently developed B. recurrentis-induced spirochetemia during the first 3 days postchallenge as concordantly detected by dark-field microscopy, culture, and quantitative PCR. However, spirochetemia was not detected from day 4 through day 10 postchallenge. The high-level spirochetemia (>107 cells/ml of blood) observed in CC046 mice was similar to that recorded in LBRF patients as well as immunocompetent mouse strains experimentally infected by tick-borne relapsing fever (RF) spirochetes, Borrelia hermsii and Borrelia persica. In contrast to the Old World and New World RF spirochetes, which develop multiple relapses (n = 3 to 9), B. recurrentis produced only single culture-detectable spirochetemia in CC046 mice. The lack of relapses may not be surprising, as LBRF patients and the grivet monkey model usually develop no or only 1 to 2 spirochetemic relapses. The novel model will now allow scientists to study B. recurrentis in the context of intact immunity.


Asunto(s)
Infecciones por Borrelia/microbiología , Borrelia/fisiología , Modelos Animales de Enfermedad , Animales , Bacteriemia , Carga Bacteriana , Infecciones por Borrelia/diagnóstico , Humanos , Ratones , Microscopía , Reacción en Cadena de la Polimerasa , Fiebre Recurrente/microbiología
13.
Int J Obes (Lond) ; 45(6): 1284-1297, 2021 06.
Artículo en Inglés | MEDLINE | ID: mdl-33723359

RESUMEN

BACKGROUND/OBJECTIVES: There is a growing appreciation for individual responses to diet. In a previous study, mouse strain-specific responses to American and ketogenic diets were observed. In this study, we searched for genetic variants underlying differences in the responses to American and ketogenic diets between C57BL/6J (B6) and FVB/NJ (FVB) mouse strains. RESULTS: Genetic mapping of fat and lean mass gain revealed QTLs on Chromosome (Chr) 1 at 191.6 Mb (Fmgq1) (P < 0.001, CI = 180.2-194.4 Mb), Chr5 at 73.7 Mb (Fmgq2, Lmgq1) (P < 0.001, CI = 66.1-76.6 Mb), and Chr7 at 40.5 Mb (Fmgq3) (P < 0.01, CI = 36.6-44.5 Mb). Analysis of serum HDL cholesterol concentration identified a significant (P < 0.001, CI = 160.6-176.1 Mb) QTL on Chr1 at 168.6 Mb (Hdlq1). Causal network inference suggests that HDL cholesterol and fat mass gain are both linked to Fmgq1. CONCLUSIONS: Strong sex effects were identified at both Fmgq2 and Lmgq1, which are also diet-dependent. Interestingly, Fmgq2 and Fmgq3 affect fat gain directly, while Fmgq1 influences fat gain directly and via an intermediate change in serum cholesterol. These results demonstrate how precision nutrition will be advanced through the integration of genetic variation and sex in physiological responses to diets varied in carbohydrate composition.


Asunto(s)
Tejido Adiposo , Dieta Cetogénica , Dieta Occidental , Sitios de Carácter Cuantitativo/genética , Tejido Adiposo/metabolismo , Tejido Adiposo/fisiología , Animales , Ratones , Factores Sexuales
14.
Hepatology ; 72(4): 1191-1203, 2020 10.
Artículo en Inglés | MEDLINE | ID: mdl-31953865

RESUMEN

BACKGROUND AND AIMS: Indole is a microbiota metabolite that exerts anti-inflammatory responses. However, the relevance of indole to human non-alcoholic fatty liver disease (NAFLD) is not clear. It also remains largely unknown whether and how indole acts to protect against NAFLD. The present study sought to examine the association between the circulating levels of indole and liver fat content in human subjects and explore the mechanisms underlying indole actions in mice with diet-induced NAFLD. APPROACH AND RESULTS: In a cohort of 137 subjects, the circulating levels of indole were reversely correlated with body mass index. In addition, the circulating levels of indole in obese subjects were significantly lower than those in lean subjects and were accompanied with increased liver fat content. At the whole-animal level, treatment of high-fat diet (HFD)-fed C57BL/6J mice with indole caused significant decreases in the severity of hepatic steatosis and inflammation. In cultured cells, indole treatment stimulated the expression of 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3 (PFKFB3), a master regulatory gene of glycolysis, and suppressed macrophage proinflammatory activation in a PFKFB3-dependent manner. Moreover, myeloid cell-specific PFKFB3 disruption exacerbated the severity of HFD-induced hepatic steatosis and inflammation and blunted the effect of indole on alleviating diet-induced NAFLD phenotype. CONCLUSIONS: Taken together, our results demonstrate that indole is relevant to human NAFLD and capable of alleviating diet-induced NAFLD phenotypes in mice in a myeloid cell PFKFB3-dependent manner. Therefore, indole mimetic and/or macrophage-specific PFKFB3 activation may be the viable preventive and/or therapeutic approaches for inflammation-associated diseases including NAFLD.


Asunto(s)
Indoles/uso terapéutico , Inflamación/tratamiento farmacológico , Células Mieloides/enzimología , Enfermedad del Hígado Graso no Alcohólico/tratamiento farmacológico , Fosfofructoquinasa-2/fisiología , Adulto , Anciano , Anciano de 80 o más Años , Animales , Células Cultivadas , Dieta Alta en Grasa , Femenino , Hepatocitos/metabolismo , Humanos , Indoles/sangre , Indoles/farmacología , Lipogénesis/efectos de los fármacos , Activación de Macrófagos/efectos de los fármacos , Masculino , Ratones , Ratones Endogámicos C57BL , Persona de Mediana Edad , Enfermedad del Hígado Graso no Alcohólico/metabolismo , Obesidad/metabolismo
15.
Arch Toxicol ; 95(3): 949-958, 2021 03.
Artículo en Inglés | MEDLINE | ID: mdl-33458792

RESUMEN

Azoxymethane (AOM) is a widely used carcinogen to study chemical-induced colorectal carcinogenesis and is an agent for studying fulminant hepatic failure. The inter-strain susceptibility to acute toxicity by AOM has been reported, but its association with host genetics or gut microbiota remains largely unexplored. Here a cohort of genetically diverse Collaborative Cross (CC) mice was used to assess the contribution of host genetics and the gut microbiome to AOM-induced acute toxicity. We observed variation in AOM-induced acute liver failure across CC strains. Quantitative trait loci (QTL) analysis revealed three chromosome regions significantly associated with AOM toxicity. Genes located within these QTL, including peroxisome proliferator-activated receptor alpha (Ppara), were enriched for enzyme activator and nucleoside-triphosphatase regulator activity. We further demonstrated that the protein level of PPARα in liver tissues from sensitive strains was remarkably lower compared to levels in resistant strains, consistent with protective role of PPAR family in liver injury. We discovered that the abundance levels of gut microbial families Anaeroplasmataceae, Ruminococcaceae, Lactobacillaceae, Akkermansiaceae and Clostridiaceae were significantly higher in the sensitive strains compared to the resistant strains. Using a random forest classifier method, we determined that the relative abundance levels of these microbial families predicted AOM toxicity with the area under the receiver-operating curve (AUC) of 0.75. Combining the three genetic loci and five microbial families increased the predictive accuracy of AOM toxicity (AUC of 0.99). Moreover, we found that Ruminococcaceae and Lactobacillaceae acted as mediators between host genetics and AOM toxicity. In conclusion, this study shows that host genetics and specific microbiome members play a critical role in AOM-induced acute toxicity, which provides a framework for analysis of the health effects from environmental toxicants.


Asunto(s)
Azoximetano/toxicidad , Carcinógenos/toxicidad , Enfermedad Hepática Inducida por Sustancias y Drogas/etiología , Microbioma Gastrointestinal , Animales , Enfermedad Hepática Inducida por Sustancias y Drogas/genética , Enfermedad Hepática Inducida por Sustancias y Drogas/microbiología , Ratones de Colaboración Cruzada , Fallo Hepático Agudo/inducido químicamente , Fallo Hepático Agudo/genética , Fallo Hepático Agudo/microbiología , Masculino , Ratones , Sitios de Carácter Cuantitativo , Especificidad de la Especie
16.
Int J Mol Sci ; 22(21)2021 Oct 21.
Artículo en Inglés | MEDLINE | ID: mdl-34768809

RESUMEN

Virus-induced neurological sequelae resulting from infection by Theiler's murine encephalomyelitis virus (TMEV) are used for studying human conditions ranging from epileptic seizures to demyelinating disease. Mouse strains are typically considered susceptible or resistant to TMEV infection based on viral persistence and extreme phenotypes, such as demyelination. We have identified a broader spectrum of phenotypic outcomes by infecting strains of the genetically diverse Collaborative Cross (CC) mouse resource. We evaluated the chronic-infection gene expression profiles of hippocampi and thoracic spinal cords for 19 CC strains in relation to phenotypic severity and TMEV persistence. Strains were clustered based on similar phenotypic profiles and TMEV levels at 90 days post-infection, and we categorized distinct TMEV response profiles. The three most common profiles included "resistant" and "susceptible," as before, as well as a "resilient" TMEV response group which experienced both TMEV persistence and mild neurological phenotypes even at 90 days post-infection. Each profile had a distinct gene expression signature, allowing the identification of pathways and networks specific to each TMEV response group. CC founder haplotypes for genes involved in these pathways/networks revealed candidate response-specific alleles. These alleles demonstrated pleiotropy and epigenetic (miRNA) regulation in long-term TMEV infection, with particular relevance for resilient mouse strains.


Asunto(s)
Infecciones por Cardiovirus/genética , Regulación de la Expresión Génica , Hipocampo/metabolismo , Médula Espinal/metabolismo , Theilovirus , Animales , Enfermedades Desmielinizantes , Modelos Animales de Enfermedad , Susceptibilidad a Enfermedades , Femenino , Masculino , Ratones , Análisis de Secuencia de ARN
17.
Mamm Genome ; 31(9-12): 263-286, 2020 12.
Artículo en Inglés | MEDLINE | ID: mdl-33015751

RESUMEN

Genetic background is known to play a role in the ability to derive pluripotent, embryonic stem cells (ESC), a trait referred to as permissiveness. Previously we demonstrated that induced pluripotent stem cells (iPSC) can be readily derived from non-permissive mouse strains by addition of serum-based media supplemented with GSK3B and MEK inhibitors, termed 2iS media, 3 days into reprogramming. Here, we describe the derivation of second type of iPSC colony from non-permissive mouse strains that can be stably maintained independently of 2iS media. The resulting cells display transcriptional heterogeneity similar to that observed in ESC from permissive genetic backgrounds derived in conventional serum containing media supplemented with leukemia inhibitor factor. However, unlike previous studies that report exclusive subpopulations, we observe both exclusive and simultaneous expression of naive and primed cell surface markers. Herein, we explore shifts in pluripotency in the presence of 2iS and characterize heterogenous subpopulations to determine their pluripotent state and role in heterogenous iPSCs derived from the non-permissive NOD/ShiLtJ strain. We conclude that heterogeneity is a naturally occurring, necessary quality of stem cells that allows for the maintenance of pluripotency. This study further demonstrates the efficacy of the 2iS reprogramming technique. It is also the first study to derive stable ESC-like stem cells from the non-permissive NOD/ShiLtJ and WSB/EiJ strains, enabling easier and broader research possibilities into pluripotency for these and similar non-permissive mouse strains and species.


Asunto(s)
Células Madre Embrionarias/citología , Células Madre Embrionarias/metabolismo , Heterogeneidad Genética , Células Madre Pluripotentes Inducidas/citología , Células Madre Pluripotentes Inducidas/metabolismo , Transcriptoma , Animales , Biomarcadores , Diferenciación Celular , Células Cultivadas , Reprogramación Celular/genética , Perfilación de la Expresión Génica , Regulación del Desarrollo de la Expresión Génica , Inmunofenotipificación , Ratones , Molécula-1 de Adhesión Celular Endotelial de Plaqueta , Especificidad de la Especie
18.
Gut ; 68(11): 1942-1952, 2019 11.
Artículo en Inglés | MEDLINE | ID: mdl-30842212

RESUMEN

OBJECTIVE: The Collaborative Cross (CC) is a mouse population model with diverse and reproducible genetic backgrounds used to identify novel disease models and genes that contribute to human disease. Since spontaneous tumour susceptibility in CC mice remains unexplored, we assessed tumour incidence and spectrum. DESIGN: We monitored 293 mice from 18 CC strains for tumour development. Genetic association analysis and RNA sequencing were used to identify susceptibility loci and candidate genes. We analysed genomes of patients with gastric cancer to evaluate the relevance of genes identified in the CC mouse model and measured the expression levels of ISG15 by immunohistochemical staining using a gastric adenocarcinoma tissue microarray. Association of gene expression with overall survival (OS) was assessed by Kaplan-Meier analysis. RESULTS: CC mice displayed a wide range in the incidence and types of spontaneous tumours. More than 40% of CC036 mice developed gastric tumours within 1 year. Genetic association analysis identified Nfκb1 as a candidate susceptibility gene, while RNA sequencing analysis of non-tumour gastric tissues from CC036 mice showed significantly higher expression of inflammatory response genes. In human gastric cancers, the majority of human orthologues of the 166 mouse genes were preferentially altered by amplification or deletion and were significantly associated with OS. Higher expression of the CC036 inflammatory response gene signature is associated with poor OS. Finally, ISG15 protein is elevated in gastric adenocarcinomas and correlated with shortened patient OS. CONCLUSIONS: CC strains exhibit tremendous variation in tumour susceptibility, and we present CC036 as a spontaneous laboratory mouse model for studying human gastric tumourigenesis.


Asunto(s)
Carcinogénesis/patología , Modelos Animales de Enfermedad , Predisposición Genética a la Enfermedad/etiología , Neoplasias Gástricas/etiología , Animales , Carcinogénesis/genética , Ratones de Colaboración Cruzada , Femenino , Masculino , Ratones , Neoplasias Gástricas/patología
19.
Infect Immun ; 87(7)2019 07.
Artículo en Inglés | MEDLINE | ID: mdl-30988058

RESUMEN

Borrelia burgdorferi is a tick-borne bacterium responsible for approximately 300,000 annual cases of Lyme disease (LD) in the United States, with increasing incidences in other parts of the world. The debilitating nature of LD is mainly attributed to the ability of B. burgdorferi to persist in patients for many years despite strong anti-Borrelia antibody responses. Antimicrobial treatment of persistent infection is challenging. Similar to infection of humans, B. burgdorferi establishes long-term infection in various experimental animal models except for New Zealand White (NZW) rabbits, which clear the spirochete within 4 to 12 weeks. LD spirochetes have a highly evolved antigenic variation vls system, on the lp28-1 plasmid, where gene conversion results in surface expression of the antigenically variable VlsE protein. VlsE is required for B. burgdorferi to establish persistent infection by continually evading otherwise potent antibodies. Since the clearance of B. burgdorferi is mediated by humoral immunity in NZW rabbits, the previously reported results that LD spirochetes lose lp28-1 during rabbit infection could potentially explain the failure of B. burgdorferi to persist. However, the present study unequivocally disproves that previous finding by demonstrating that LD spirochetes retain the vls system. However, despite the vls system being fully functional, the spirochete fails to evade anti-Borrelia antibodies of NZW rabbits. In addition to being protective against homologous and heterologous challenges, the rabbit antibodies significantly ameliorate LD-induced arthritis in persistently infected mice. Overall, the current data indicate that NZW rabbits develop a protective antibody repertoire, whose specificities, once defined, will identify potential candidates for a much-anticipated LD vaccine.


Asunto(s)
Variación Antigénica/fisiología , Antígenos Bacterianos/inmunología , Borrelia burgdorferi/genética , Enfermedad de Lyme/inmunología , Enfermedad de Lyme/microbiología , Animales , Anticuerpos Antibacterianos/inmunología , Proteínas Bacterianas/genética , Lipoproteínas/genética , Plásmidos , Conejos
20.
Chem Res Toxicol ; 32(5): 887-898, 2019 05 20.
Artículo en Inglés | MEDLINE | ID: mdl-30990016

RESUMEN

Metabolism of 1,3-butadiene, a known human and rodent carcinogen, results in formation of reactive epoxides, a key event in its carcinogenicity. Although mice exposed to 1,3-butadiene present DNA adducts in all tested tissues, carcinogenicity is limited to liver, lung, and lymphoid tissues. Previous studies demonstrated that strain- and tissue-specific epigenetic effects in response to 1,3-butadiene exposure may influence susceptibly to DNA damage and serve as a potential mechanism of tissue-specific carcinogenicity. This study aimed to investigate interindividual variability in the effects of 1,3-butadiene using a population-based mouse model. Male mice from 20 Collaborative Cross strains were exposed to 0 or 635 ppm 1,3-butadiene by inhalation (6 h/day, 5 days/week) for 2 weeks. We evaluated DNA damage and epigenetic effects in target (lung and liver) and nontarget (kidney) tissues of 1,3-butadiene-induced carcinogenesis. DNA damage was assessed by measuring N-7-(2,3,4-trihydroxybut-1-yl)-guanine (THB-Gua) adducts. To investigate global histone modification alterations, we evaluated the trimethylation and acetylation of histones H3 and H4 across tissues. Changes in global cytosine DNA methylation were evaluated from the levels of methylation of LINE-1 and SINE B1 retrotransposons. We quantified the degree of variation across strains, deriving a chemical-specific human variability factor to address population variability in carcinogenic risk, which is largely ignored in current cancer risk assessment practice. Quantitative trait locus mapping identified four candidate genes related to chromatin remodeling whose variation was associated with interstrain susceptibility. Overall, this study uses 1,3-butadiene to demonstrate how the Collaborative Cross mouse population can be used to identify the mechanisms for and quantify the degree of interindividual variability in tissue-specific effects that are relevant to chemically induced carcinogenesis.


Asunto(s)
Butadienos/toxicidad , Aductos de ADN/metabolismo , Epigénesis Genética/efectos de los fármacos , Animales , Carcinógenos Ambientales/toxicidad , Aductos de ADN/química , Aductos de ADN/genética , Metilación de ADN/efectos de los fármacos , Guanina/análogos & derivados , Guanina/química , Histonas/metabolismo , Riñón/efectos de los fármacos , Hígado/efectos de los fármacos , Pulmón/efectos de los fármacos , Masculino , Ratones , Mutágenos/toxicidad
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA