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1.
bioRxiv ; 2023 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-37904917

RESUMO

Bacterial artificial chromosome transgenic models, including most Cre-recombinases, enable potent interrogation of gene function in vivo but require rigorous validation as limitations emerge. Due to its high relevance to metabolic studies, we performed comprehensive analysis of the Ucp1-CreEvdr line which is widely used for brown fat research. Hemizygotes exhibited major brown and white fat transcriptomic dysregulation, indicating potential altered tissue function. Ucp1-CreEvdr homozygotes also show high mortality, growth defects, and craniofacial abnormalities. Mapping the transgene insertion site revealed insertion in chromosome 1 accompanied by large genomic alterations disrupting several genes expressed in a range of tissues. Notably, Ucp1-CreEvdr transgene retains an extra Ucp1 gene copy that may be highly expressed under high thermogenic burden. Our multi-faceted analysis highlights a complex phenotype arising from the presence of the Ucp1-CreEvdr transgene independently of the intended genetic manipulations. Overall, comprehensive validation of transgenic mice is imperative to maximize discovery while mitigating unexpected, off-target effects.

2.
J Vis Exp ; (195)2023 05 12.
Artigo em Inglês | MEDLINE | ID: mdl-37246886

RESUMO

Fatty acid synthesis is a complex and highly energy demanding metabolic pathway with important functional roles in the control of whole-body metabolic homeostasis and other physiological and pathological processes. Contrary to other key metabolic pathways, such as glucose disposal, fatty acid synthesis is not routinely functionally assessed, leading to incomplete interpretations of metabolic status. In addition, there is a lack of publicly available detailed protocols suitable for newcomers in the field. Here, we describe an inexpensive quantitative method utilizing deuterium oxide and gas chromatography mass spectrometry (GCMS) for the analysis of total fatty acid de novo synthesis in brown adipose tissue in vivo. This method measures the synthesis of the products of fatty acid synthase independently of a carbon source, and it is potentially useful for virtually any tissue, in any mouse model, and under any external perturbation. Details on the sample preparation for GCMS and downstream calculations are provided. We focus on the analysis of brown fat due to its high levels of de novo fatty acid synthesis and critical roles in maintaining metabolic homeostasis.


Assuntos
Tecido Adiposo Marrom , Ácidos Graxos , Camundongos , Animais , Tecido Adiposo Marrom/metabolismo , Óxido de Deutério , Ácidos Graxos/metabolismo , Lipogênese , Glucose/metabolismo , Tecido Adiposo/metabolismo
3.
Shock ; 59(5): 779-790, 2023 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-36840516

RESUMO

ABSTRACT: Introduction: Sepsis is a dysregulated host response to infection that can lead to life-threatening organ dysfunction. Clinical and animal studies consistently demonstrate that female subjects are less susceptible to the adverse effects of sepsis, demonstrating the importance of understanding how sex influences sepsis outcomes. The signal transducer and activator of transcription 3 (STAT3) pathway are a major signaling pathway that facilitates inflammation during sepsis. STAT3 is abundantly expressed in white adipose tissue; however, little is known about the contribution of white adipose tissue STAT3 activation during sepsis. We hypothesize that adipocyte STAT3 inhibition during severe sepsis will exaggerate the inflammatory response and impact organ injury, in a sex-dependent manner. Methods: We generated STAT3 flox/flox (wild-type [WT]) and adipocyte STAT3 knock out (A-STAT3 KO) mice using Cre-lox technology. Studies were done in 12- to 16-week-old male and female mice. Polymicrobial sepsis was induced by cecal ligation and puncture (CLP). Control nonseptic mice did not undergo CLP (0 h CLP). Tissues were harvested 18 h after CLP. Body composition was determined by echo magnetic resonance imaging. Energy metabolism was determined by indirect calorimetry. White adipose tissue morphology was determined by hematoxylin and eosin staining, while STAT3 activation in the white adipose tissue was determined by western blot analysis and immunohistochemistry staining of STAT3 activation/phosphorylation at tyrosine 705. Plasma cytokines (TNF-α, IL-6, and leptin) were determined by luminex assay. Neutrophil infiltration of the lung and liver was assessed by myeloperoxidase activity assay. Histological signs of organ injury on lung and liver tissue were assessed by hematoxylin and eosin staining. Liver injury was further assessed by measuring plasma alanine and aspartate aminotransferase. In a separate cohort of mice, sepsis was induced by CLP and mice were monitored every 6-12 h over a 7-day period to assess survival rate. Results: We demonstrate that neither body composition nor energy metabolism is altered with adipocyte STAT3 inhibition in male or female mice, under nonseptic conditions. Sepsis was associated with reduced adipocyte size in female WT and A-STAT3 KO mice, suggesting that this event is STAT3 independent. Sepsis did not alter adipocyte size in male WT and A-STAT3 KO mice, suggesting that this event is also sex dependent. Although STAT3 phosphorylation at tyrosine 705 expression is negligible in male and female A-STAT3 KO mice, septic female WT and A-STAT3 KO mice have higher white adipose tissue STAT3 activation than male WT and A-STAT3 KO mice. Adipocyte STAT3 inhibition did not alter the proinflammatory cytokine response during sepsis in male or female mice, as measured by plasma TNF-α, IL-6, and leptin levels. Adipocyte STAT3 inhibition reduced lung neutrophil infiltration and histological signs of lung injury during sepsis in male mice. On the contrary, adipocyte STAT3 inhibition had no effect on lung neutrophil infiltration or lung injury in female mice. We further demonstrate that neither liver neutrophil infiltration nor histological signs of liver injury are altered by adipocyte STAT3 inhibition during sepsis, in male or female mice. Lastly, adipocyte STAT3 inhibition did not affect survival rate of male or female mice during sepsis. Conclusions: Our study demonstrates that sex influences white adipose tissue STAT3 activation and morphology during sepsis, which is not dependent on the presence of functional STAT3 in mature adipocytes. Furthermore, genetic inhibition of adipocyte STAT3 activation in male, but not female mice, results in reduced lung neutrophil infiltration and lung injury during sepsis. The results from our study demonstrate the importance of considering biological sex and the white adipose tissue as potential sources and targets of inflammation during sepsis.


Assuntos
Lesão Pulmonar , Sepse , Masculino , Camundongos , Animais , Leptina , Lesão Pulmonar/complicações , Fator de Necrose Tumoral alfa , Interleucina-6 , Fator de Transcrição STAT3/genética , Amarelo de Eosina-(YS) , Hematoxilina , Sepse/patologia , Citocinas , Inflamação , Adipócitos , Camundongos Endogâmicos C57BL , Modelos Animais de Doenças
4.
Nanomaterials (Basel) ; 12(5)2022 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-35269316

RESUMO

Atomic layer deposition (ALD) is a vapor-phase deposition technique that has attracted increasing attention from both experimentalists and theoreticians in the last few decades. ALD is well-known to produce conformal, uniform, and pinhole-free thin films across the surface of substrates. Due to these advantages, ALD has found many engineering and biomedical applications. However, drawbacks of ALD should be considered. For example, the reaction mechanisms cannot be thoroughly understood through experiments. Moreover, ALD conditions such as materials, pulse and purge durations, and temperature should be optimized for every experiment. It is practically impossible to perform many experiments to find materials and deposition conditions that achieve a thin film with desired applications. Additionally, only existing materials can be tested experimentally, which are often expensive and hazardous, and their use should be minimized. To overcome ALD limitations, theoretical methods are beneficial and essential complements to experimental data. Recently, theoretical approaches have been reported to model, predict, and optimize different ALD aspects, such as materials, mechanisms, and deposition characteristics. Those methods can be validated using a different theoretical approach or a few knowledge-based experiments. This review focuses on recent computational advances in thermal ALD and discusses how theoretical methods can make experiments more efficient.

5.
Methods Mol Biol ; 2448: 203-215, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35167099

RESUMO

Techniques to trace and isolate brown adipocyte precursor and adipocytes during development and disease are essential to fully understand brown adipose tissue development and function. Here we report several protocols using the R26R-mTmG reporter mice in thermogenic tissues based on confocal microscopy and fluorescence based flow cytometry. These techniques may be useful to understand the influence of genetic or environmental alterations in brown adipocyte precursors and adipocyte biology.


Assuntos
Adipócitos Marrons , Tecido Adiposo Marrom , Adipogenia , Animais , Citometria de Fluxo , Camundongos , Termogênese/genética
6.
Nat Commun ; 12(1): 2911, 2021 05 18.
Artigo em Inglês | MEDLINE | ID: mdl-34006859

RESUMO

The impact of immune mediators on weight homeostasis remains underdefined. Interrogation of resistance to diet-induced obesity in mice lacking a negative regulator of Toll-like receptor signaling serendipitously uncovered a role for B cell activating factor (BAFF). Here we show that overexpression of BAFF in multiple mouse models associates with protection from weight gain, approximating a log-linear dose response relation to BAFF concentrations. Gene expression analysis of BAFF-stimulated subcutaneous white adipocytes unveils upregulation of lipid metabolism pathways, with BAFF inducing white adipose tissue (WAT) lipolysis. Brown adipose tissue (BAT) from BAFF-overexpressing mice exhibits increased Ucp1 expression and BAFF promotes brown adipocyte respiration and in vivo energy expenditure. A proliferation-inducing ligand (APRIL), a BAFF homolog, similarly modulates WAT and BAT lipid handling. Genetic deletion of both BAFF and APRIL augments diet-induced obesity. Lastly, BAFF/APRIL effects are conserved in human adipocytes and higher BAFF/APRIL levels correlate with greater BMI decrease after bariatric surgery. Together, the BAFF/APRIL axis is a multifaceted immune regulator of weight gain and adipose tissue function.


Assuntos
Fator Ativador de Células B/genética , Obesidade/genética , Transdução de Sinais/genética , Membro 13 da Superfamília de Ligantes de Fatores de Necrose Tumoral/genética , Aumento de Peso/genética , Adipócitos/citologia , Adipócitos/metabolismo , Tecido Adiposo Marrom/citologia , Tecido Adiposo Marrom/metabolismo , Tecido Adiposo Branco/citologia , Tecido Adiposo Branco/metabolismo , Animais , Fator Ativador de Células B/metabolismo , Células Cultivadas , Dieta Hiperlipídica/efeitos adversos , Perfilação da Expressão Gênica/métodos , Humanos , Masculino , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Obesidade/etiologia , Obesidade/metabolismo , Membro 13 da Superfamília de Ligantes de Fatores de Necrose Tumoral/metabolismo
7.
PLoS Comput Biol ; 16(9): e1008191, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32970665

RESUMO

Environmental toxicants affect human health in various ways. Of the thousands of chemicals present in the environment, those with adverse effects on the endocrine system are referred to as endocrine-disrupting chemicals (EDCs). Here, we focused on a subclass of EDCs that impacts the estrogen receptor (ER), a pivotal transcriptional regulator in health and disease. Estrogenic activity of compounds can be measured by many in vitro or cell-based high throughput assays that record various endpoints from large pools of cells, and increasingly at the single-cell level. To simultaneously capture multiple mechanistic ER endpoints in individual cells that are affected by EDCs, we previously developed a sensitive high throughput/high content imaging assay that is based upon a stable cell line harboring a visible multicopy ER responsive transcription unit and expressing a green fluorescent protein (GFP) fusion of ER. High content analysis generates voluminous multiplex data comprised of minable features that describe numerous mechanistic endpoints. In this study, we present a machine learning pipeline for rapid, accurate, and sensitive assessment of the endocrine-disrupting potential of benchmark chemicals based on data generated from high content analysis. The multidimensional imaging data was used to train a classification model to ultimately predict the impact of unknown compounds on the ER, either as agonists or antagonists. To this end, both linear logistic regression and nonlinear Random Forest classifiers were benchmarked and evaluated for predicting the estrogenic activity of unknown compounds. Furthermore, through feature selection, data visualization, and model discrimination, the most informative features were identified for the classification of ER agonists/antagonists. The results of this data-driven study showed that highly accurate and generalized classification models with a minimum number of features can be constructed without loss of generality, where these machine learning models serve as a means for rapid mechanistic/phenotypic evaluation of the estrogenic potential of many chemicals.


Assuntos
Algoritmos , Estrogênios/classificação , Aprendizado de Máquina , Linhagem Celular , Estrogênios/metabolismo , Humanos , Receptores de Estrogênio/metabolismo
8.
Nature ; 585(7825): 420-425, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32879486

RESUMO

The opsin family of G-protein-coupled receptors are used as light detectors in animals. Opsin 5 (also known as neuropsin or OPN5) is a highly conserved opsin that is sensitive to visible violet light1,2. In mice, OPN5 is a known photoreceptor in the retina3 and skin4 but is also expressed in the hypothalamic preoptic area (POA)5. Here we describe a light-sensing pathway in which POA neurons that express Opn5 regulate thermogenesis in brown adipose tissue (BAT). We show that Opn5 is expressed in glutamatergic warm-sensing POA neurons that receive synaptic input from several thermoregulatory nuclei. We further show that Opn5 POA neurons project to BAT and decrease its activity under chemogenetic stimulation. Opn5-null mice show overactive BAT, increased body temperature, and exaggerated thermogenesis when cold-challenged. Moreover, violet photostimulation during cold exposure acutely suppresses BAT temperature in wild-type mice but not in Opn5-null mice. Direct measurements of intracellular cAMP ex vivo show that Opn5 POA neurons increase cAMP when stimulated with violet light. This analysis thus identifies a violet light-sensitive deep brain photoreceptor that normally suppresses BAT thermogenesis.


Assuntos
Cor , Luz , Proteínas de Membrana/metabolismo , Neurônios/metabolismo , Neurônios/efeitos da radiação , Opsinas/metabolismo , Área Pré-Óptica/citologia , Termogênese/efeitos da radiação , Tecido Adiposo Marrom/inervação , Tecido Adiposo Marrom/metabolismo , Tecido Adiposo Marrom/efeitos da radiação , Animais , Temperatura Corporal , Temperatura Baixa , AMP Cíclico/metabolismo , Feminino , Masculino , Proteínas de Membrana/deficiência , Proteínas de Membrana/genética , Camundongos , Opsinas/deficiência , Opsinas/genética , Termogênese/genética
9.
Nat Commun ; 11(1): 2745, 2020 06 02.
Artigo em Inglês | MEDLINE | ID: mdl-32488081

RESUMO

White adipose tissue inflammation, in part via myeloid cell contribution, is central to obesity pathogenesis. Mechanisms regulating adipocyte inflammatory potential and consequent impact of such inflammation in disease pathogenesis remain poorly defined. We show that activation of the type I interferon (IFN)/IFNα receptor (IFNAR) axis amplifies adipocyte inflammatory vigor and uncovers dormant gene expression patterns resembling inflammatory myeloid cells. IFNß-sensing promotes adipocyte glycolysis, while glycolysis inhibition impeded IFNß-driven intra-adipocyte inflammation. Obesity-driven induction of the type I IFN axis and activation of adipocyte IFNAR signaling contributes to obesity-associated pathogenesis in mice. Notably, IFNß effects are conserved in human adipocytes and detection of the type I IFN/IFNAR axis-associated signatures positively correlates with obesity-driven metabolic derangements in humans. Collectively, our findings reveal a capacity for the type I IFN/IFNAR axis to regulate unifying inflammatory features in both myeloid cells and adipocytes and hint at an underappreciated contribution of adipocyte inflammation in disease pathogenesis.


Assuntos
Adipócitos/metabolismo , Inflamação/metabolismo , Interferon Tipo I/metabolismo , Obesidade/metabolismo , Animais , Modelos Animais de Doenças , Expressão Gênica , Humanos , Interferon beta/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Células Mieloides/metabolismo , Receptor de Interferon alfa e beta/metabolismo
10.
Cell Rep ; 30(3): 672-686.e8, 2020 01 21.
Artigo em Inglês | MEDLINE | ID: mdl-31968245

RESUMO

Almost all life forms can detect and decode light information for adaptive advantage. Examples include the visual system, in which photoreceptor signals are processed into virtual images, and the circadian system, in which light entrains a physiological clock. Here we describe a light response pathway in mice that employs encephalopsin (OPN3, a 480 nm, blue-light-responsive opsin) to regulate the function of adipocytes. Germline null and adipocyte-specific conditional null mice show a light- and Opn3-dependent deficit in thermogenesis and become hypothermic upon cold exposure. We show that stimulating mouse adipocytes with blue light enhances the lipolysis response and, in particular, phosphorylation of hormone-sensitive lipase. This response is Opn3 dependent. These data establish a key mechanism in which light-dependent, local regulation of the lipolysis response in white adipocytes regulates energy metabolism.


Assuntos
Adipócitos Marrons/metabolismo , Adipócitos Marrons/efeitos da radiação , Adipócitos Brancos/metabolismo , Adipócitos Brancos/efeitos da radiação , Luz , Opsinas de Bastonetes/metabolismo , Termogênese/efeitos da radiação , Animais , Temperatura Baixa , Metabolismo Energético/efeitos da radiação , Perfilação da Expressão Gênica , Lipólise/efeitos da radiação , Camundongos Endogâmicos C57BL , Fenótipo , Fótons , Termogênese/genética
11.
ESCAPE ; 46: 967-972, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31612156

RESUMO

The National Institute of Environmental Health Sciences (NIEHS) Superfund Research Program (SRP) aims to support university-based multidisciplinary research on human health and environmental issues related to hazardous substances and pollutants. The Texas A&M Superfund Research Program comprehensively evaluates the complexities of hazardous chemical mixtures and their potential adverse health impacts due to exposure through a number of multi-disciplinary projects and cores. One of the essential components of the Texas A&M Superfund Research Center is the Data Science Core, which serves as the basis for translating the data produced by the multi-disciplinary research projects into useful knowledge for the community via data collection, quality control, analysis, and model generation. In this work, we demonstrate the Texas A&M Superfund Research Program computational platform, which houses and integrates large-scale, diverse datasets generated across the Center, provides basic visualization service to facilitate interpretation, monitors data quality, and finally implements a variety of state-of-the-art statistical analysis for model/tool development. The platform is aimed to facilitate effective integration and collaboration across the Center and acts as an enabler for the dissemination of comprehensive ad-hoc tools and models developed to address the environmental and health effects of chemical mixture exposure during environmental emergency-related contamination events.

12.
Sci Total Environ ; 651(Pt 2): 2749-2761, 2019 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-30463129

RESUMO

A wide variety of water sources, treatment methods, and recycling options have created a myriad of water management options. For modeling of sustainable water treatment options, computationally efficient models may be required. This paper provides a comprehensive and comparative review of the water management systems and the associated economic, environmental, and performance metrics. The water management systems are represented as a network of sources, users, technologies, recycling options, and quality of water. Special attention is given to desalination systems. The two main technology categories currently used for desalination are thermal (e.g., Multistage Flash "MSF", Multi-Effect Distillation "MED", and Mechanical Vapor Compression "MVC") and membrane (e.g., seawater reverse osmosis "SWRO", brackish water reverse osmosis "BWRO"). The cost assessment includes a capital cost comparison (for which regression analysis has been used to account for the non-linear nature of the capacity-cost curves), an operating cost comparison, which includes energy requirements, labor costs, chemicals used, maintenance and repair costs, membrane replacement costs and a unit product cost ($/m3) breakdown, which combines the capital and operating costs. Numerous data were collected for the cost of desalination systems. Statistical methods were then used to analyze these collected data to establish deeper understanding of the relationship to capital cost, operating cost, capacity, constraints due to treatment method capabilities, requirements of the users. The paper also briefly discusses other cost considerations such as the water intake and distribution costs. The environmental impacts (concentrate disposal and CO2 footprint) have also been compared for the various technologies considered. Some integration strategies such as use of hybrid systems, cogeneration plants and use of renewable energy have shown reductions in cost associated due to energy consumption and thereby, reducing the unit product cost. Finally, the paper provides a selection guide suitable for various situations with consideration of the different factors affecting cost, environmental impact and energy demands.

13.
Hepatol Commun ; 2(5): 546-560, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29761170

RESUMO

Nonalcoholic fatty liver disease (NAFLD) represents a disease spectrum ranging from benign steatosis to life-threatening cirrhosis and hepatocellular carcinoma. Elevated levels of reactive oxygen species (ROS) and exacerbated inflammatory responses have been implicated in NAFLD progression. Nicotinamide adenine dinucleotide phosphate (reduced) oxidase 2 (NOX2; also known as gp91Phox), the main catalytic subunit of the nicotinamide adenine dinucleotide phosphate (reduced) oxidase complex, modulates ROS production, immune responsiveness, and pathogenesis of obesity-associated metabolic derangements. However, the role of NOX2 in the regulation of immune cell function and inflammatory vigor in NAFLD remains underdefined. Here, we demonstrate that obesogenic diet feeding promoted ROS production by bone marrow, white adipose tissue, and liver immune cells. Genetic ablation of NOX2 impeded immune cell ROS synthesis and was sufficient to uncouple obesity from glucose dysmetabolism and NAFLD pathogenesis. Protection from hepatocellular damage in NOX2-deficient mice correlated with reduced hepatic neutrophil, macrophage, and T-cell infiltration, diminished production of key NAFLD-driving proinflammatory cytokines, and an inherent reduction in T-cell polarization toward Th17 phenotype. Conclusion: Current findings demonstrate a crucial role of the NOX2-ROS axis in immune cell effector function and polarization and consequent NAFLD progression in obesity. Pharmacologic targeting of NOX2 function in immune cells may represent a viable approach for reducing morbidity of obesity-associated NAFLD pathogenesis. (Hepatology Communications 2018;2:546-560).

14.
JCI Insight ; 3(6)2018 03 22.
Artigo em Inglês | MEDLINE | ID: mdl-29563328

RESUMO

Nonalcoholic fatty liver disease (NAFLD), a metabolic predisposition for development of hepatocellular carcinoma (HCC), represents a disease spectrum ranging from steatosis to steatohepatitis to cirrhosis. Acox1, a rate-limiting enzyme in peroxisomal fatty acid ß-oxidation, regulates metabolism, spontaneous hepatic steatosis, and hepatocellular damage over time. However, it is unknown whether Acox1 modulates inflammation relevant to NAFLD pathogenesis or if Acox1-associated metabolic and inflammatory derangements uncover and accelerate potential for NAFLD progression. Here, we show that mice with a point mutation in Acox1 (Acox1Lampe1) exhibited altered cellular metabolism, modified T cell polarization, and exacerbated immune cell inflammatory potential. Further, in context of a brief obesogenic diet stress, NAFLD progression associated with Acox1 mutation resulted in significantly accelerated and exacerbated hepatocellular damage via induction of profound histological changes in hepatocytes, hepatic inflammation, and robust upregulation of gene expression associated with HCC development. Collectively, these data demonstrate that ß-oxidation links metabolism and immune responsiveness and that a better understanding of peroxisomal ß-oxidation may allow for discovery of mechanisms central for NAFLD progression.


Assuntos
Acil-CoA Oxidase/metabolismo , Carcinoma Hepatocelular/imunologia , Carcinoma Hepatocelular/metabolismo , Neoplasias Hepáticas/metabolismo , Hepatopatia Gordurosa não Alcoólica/metabolismo , Acil-CoA Oxidase/genética , Tecido Adiposo Marrom/metabolismo , Animais , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/patologia , Citocinas/metabolismo , Dieta , Modelos Animais de Doenças , Progressão da Doença , Ácidos Graxos/metabolismo , Regulação Neoplásica da Expressão Gênica , Hepatócitos/patologia , Inflamação , Fígado/imunologia , Fígado/metabolismo , Fígado/patologia , Cirrose Hepática , Neoplasias Hepáticas/genética , Camundongos , Camundongos Endogâmicos C57BL , Mitocôndrias/metabolismo , Hepatopatia Gordurosa não Alcoólica/patologia , Obesidade , Mutação Puntual , Estresse Fisiológico , Linfócitos T
16.
Nat Med ; 23(7): 829-838, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28604704

RESUMO

Nonalcoholic fatty liver disease (NAFLD), a common prelude to cirrhosis and hepatocellular carcinoma, is the most common chronic liver disease worldwide. Defining the molecular mechanisms underlying the pathogenesis of NAFLD has been hampered by a lack of animal models that closely recapitulate the severe end of the disease spectrum in humans, including bridging hepatic fibrosis. Here we demonstrate that a novel experimental model employing thermoneutral housing, as opposed to standard housing, resulted in lower stress-driven production of corticosterone, augmented mouse proinflammatory immune responses and markedly exacerbated high-fat diet (HFD)-induced NAFLD pathogenesis. Disease exacerbation at thermoneutrality was conserved across multiple mouse strains and was associated with augmented intestinal permeability, an altered microbiome and activation of inflammatory pathways that are associated with the disease in humans. Depletion of Gram-negative microbiota, hematopoietic cell deletion of Toll-like receptor 4 (TLR4) and inactivation of the IL-17 axis resulted in altered immune responsiveness and protection from thermoneutral-housing-driven NAFLD amplification. Finally, female mice, typically resistant to HFD-induced obesity and NAFLD, develop full disease characteristics at thermoneutrality. Thus, thermoneutral housing provides a sex-independent model of exacerbated NAFLD in mice and represents a novel approach for interrogation of the cellular and molecular mechanisms underlying disease pathogenesis.


Assuntos
Dieta Hiperlipídica , Abrigo para Animais , Hepatopatia Gordurosa não Alcoólica/metabolismo , Obesidade/metabolismo , Receptores de Interleucina-17/imunologia , Estresse Fisiológico/imunologia , Temperatura , Receptor 4 Toll-Like/metabolismo , Animais , Temperatura Baixa , Corticosterona/metabolismo , Modelos Animais de Doenças , Progressão da Doença , Feminino , Citometria de Fluxo , Microbioma Gastrointestinal/imunologia , Perfilação da Expressão Gênica , Bactérias Gram-Negativas/imunologia , Células-Tronco Hematopoéticas/metabolismo , Humanos , Inflamação , Mucosa Intestinal/metabolismo , Jejuno/metabolismo , Aprendizado de Máquina , Masculino , Camundongos , Camundongos Knockout , Hepatopatia Gordurosa não Alcoólica/imunologia , Obesidade/imunologia , Permeabilidade , Receptores de Interleucina-17/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fatores Sexuais , Receptor 4 Toll-Like/genética
17.
Mol Metab ; 5(11): 1121-1130, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27818938

RESUMO

OBJECTIVES: Obesity and obesity-associated inflammation is central to a variety of end-organ sequelae including atherosclerosis, a leading cause of death worldwide. Although mouse models have provided important insights into the immunopathogenesis of various diseases, modeling atherosclerosis in mice has proven difficult. Specifically, wild-type (WT) mice are resistant to developing atherosclerosis, while commonly used genetically modified mouse models of atherosclerosis are poor mimics of human disease. The lack of a physiologically relevant experimental model of atherosclerosis has hindered the understanding of mechanisms regulating disease development and progression as well as the development of translational therapies. Recent evidence suggests that housing mice within their thermoneutral zone profoundly alters murine physiology, including both metabolic and immune processes. We hypothesized that thermoneutral housing would allow for augmentation of atherosclerosis induction and progression in mice. METHODS: ApoE-/- and WT mice were housed at either standard (TS) or thermoneutral (TN) temperatures and fed either a chow or obesogenic "Western" diet. Analysis included quantification of (i) obesity and obesity-associated downstream sequelae, (ii) the development and progression of atherosclerosis, and (iii) inflammatory gene expression pathways related to atherosclerosis. RESULTS: Housing mice at TN, in combination with an obesogenic "Western" diet, profoundly augmented obesity development, exacerbated atherosclerosis in ApoE-/- mice, and initiated atherosclerosis development in WT mice. This increased disease burden was associated with altered lipid profiles, including cholesterol levels and fractions, and increased aortic plaque size. In addition to the mild induction of atherosclerosis, we similarly observed increased levels of aortic and white adipose tissue inflammation and increased circulating immune cell expression of pathways related to adverse cardiovascular outcome. CONCLUSIONS: In sum, our novel data in WT C57Bl/6 mice suggest that modulation of a single environmental variable, temperature, dramatically alters mouse physiology, metabolism, and inflammation, allowing for an improved mouse model of atherosclerosis. Thus, thermoneutral housing of mice shows promise in yielding a better understanding of the cellular and molecular pathways underlying the pathogenesis of diverse diseases.


Assuntos
Aterosclerose/imunologia , Inflamação , Temperatura , Animais , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout
18.
Mol Cell Biochem ; 415(1-2): 51-66, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26915100

RESUMO

We previously reported that curcumin induces browning of primary white adipocytes via enhanced expression of brown adipocyte-specific genes. In this study, we attempted to identify target proteins responsible for this fat-browning effect by analyzing proteomic changes in cultured white adipocytes in response to curcumin treatment. To elucidate the role of curcumin in fat-browning, we conducted comparative proteomic analysis of primary adipocytes between control and curcumin-treated cells using two-dimensional electrophoresis combined with MALDI-TOF-MS. We also investigated fatty acid metabolic targets, mitochondrial biogenesis, and fat-browning-associated proteins using combined proteomic and network analyses. Proteomic analysis revealed that 58 protein spots from a total of 325 matched spots showed differential expression between control and curcumin-treated adipocytes. Using network analysis, most of the identified proteins were proven to be involved in various metabolic and cellular processes based on the PANTHER classification system. One of the most striking findings is that hormone-sensitive lipase (HSL) was highly correlated with main browning markers based on the STRING database. HSL and two browning markers (UCP1, PGC-1α) were co-immunoprecipitated with these markers, suggesting that HSL possibly plays a role in fat-browning of white adipocytes. Our results suggest that curcumin increased HSL levels and other browning-specific markers, suggesting its possible role in augmentation of lipolysis and suppression of lipogenesis by trans-differentiation from white adipocytes into brown adipocytes (beige).


Assuntos
Adipócitos/efeitos dos fármacos , Biomarcadores/metabolismo , Curcumina/farmacologia , Proteômica , Adipócitos/citologia , Adipócitos/metabolismo , Animais , Diferenciação Celular , Células Cultivadas , Eletroforese em Gel Bidimensional , Ratos , Ratos Sprague-Dawley , Reação em Cadeia da Polimerase em Tempo Real , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz
19.
Life Sci ; 148: 112-7, 2016 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-26880535

RESUMO

AIMS: Galectin-1 (GAL1) is an important member of the lectin family with a carbohydrate recognition domain and has recently been demonstrated to be involved in adipose metabolism. In the present study, we investigated the effects of targeted inhibition of GAL1 by its binding inhibitor lactulose under high fat diet (HFD)-induced obesity. MAIN METHODS: Effects of targeted inhibition of GAL1 by lactulose on lipid metabolism were investigated in vitro and in vivo. Changes in lipogenic capacity in lactulose-treated adipocytes were demonstrated by Oil Red O staining, triglyceride quantification and major adipogenic marker expression patterns. After lactulose treatment in Sprague-Dawley rats, various important body weight parameters, food efficiency, plasma metabolic parameters (glucose, ALT, free fatty acid, triglycerides, leptin, and insulin) and metabolic protein expression patterns were evaluated. KEY FINDINGS: Lactulose treatment reduced adipogenesis and fat accumulation in vitro by down-regulation of major adipogenic transcription factors such as C/EBPα and PPARγ. In vivo treatment of lactulose to 5-week-old Sprague-Dawley male rats significantly alleviated HFD-induced body weight gain and food efficiency as well as improved plasma and other metabolic parameters. In addition, lactulose treatment down-regulated major adipogenic marker proteins (C/EBPα and PPARγ) in adipose tissue as well as stimulated expression of proteins involved in energy expenditure and lipolysis (ATP5B, COXIV, HSL, and CPT1). SIGNIFICANCE: In conclusion, reduced adipogenesis and increased energy expenditure mediated by lactulose treatment synergistically contribute to alleviation of HFD-induced body weight gain. Therefore, pharmaceutical targeting of GAL1 using lactulose would be a novel therapeutic approach for the treatment of obesity.


Assuntos
Adipogenia/fisiologia , Dieta Hiperlipídica/efeitos adversos , Galectina 1/antagonistas & inibidores , Lactulose/farmacologia , Obesidade/tratamento farmacológico , Aumento de Peso/efeitos dos fármacos , Células 3T3-L1 , Adipócitos/efeitos dos fármacos , Adipócitos/metabolismo , Adipogenia/efeitos dos fármacos , Animais , Fármacos Antiobesidade/farmacologia , Fármacos Antiobesidade/uso terapêutico , Relação Dose-Resposta a Droga , Galectina 1/sangue , Lactulose/uso terapêutico , Masculino , Camundongos , Obesidade/sangue , Obesidade/etiologia , Ratos , Ratos Sprague-Dawley , Aumento de Peso/fisiologia
20.
Microbiol Res ; 183: 80-91, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26805621

RESUMO

Profuse growth of Lycpodium cernuum L. was found in phosphate deficient red lateritic soil of West Bengal, India. Interaction of vesicular-arbuscular mycorrhiza (VAM) with Lycopodium rhizoids were described earlier but association of PGPR with their rhizoids were not studied. Three potent phosphate solubilizing bacterial strains (P4, P9 and P10) associated with L. cernuum rhizoids were isolated and identified by 16S rDNA homologies on Ez-Taxon database as Burkholderia tropica, Burkholderia unamae and Burkholderia cepacia respectively. Day wise kinetics of phosphate solubilization against Ca3(PO4)2 suggested P4 (580.56±13.38 µg ml(-1)) as maximum mineral phosphate solubilizer followed by P9 (517.12±17.15 µg ml(-1)) and P10 (485.18±14.23 µg ml(-1)) at 28 °C. Release of bound phosphates by isolated strains from ferric phosphate (FePO4), aluminum phosphate (AlPO4) and four different complex rock phosphates indicated their very good phosphate solubilizng efficacy. Nitrogen independent solubilizition also supports their nitrogen fixing capabilities. Inhibition of P solubilization by calcium salts and induction by EDTA suggested pH dependent chelation of metal cations by all of the isolates. Rhizoidal colonization potentials of Burkholderia spp. were confirmed by in planta experiment and also using scanning electron microscope (SEM). Increases of total phosphate content in Lycopodium plants upon soil treatment with these isolates were also recorded. In addition siderophore production on CAS agar medium, tryptophan dependent IAA production and antifungal activities against pathogenic fungi by rhizospheric isolates deep-rooted that they have definite role in nutrient mobilization for successful colonization of L. cernuum in nutrient deficient lateritic soil.


Assuntos
Burkholderia/metabolismo , Lycopodium/crescimento & desenvolvimento , Lycopodium/microbiologia , Fosfatos/metabolismo , Compostos de Alumínio/metabolismo , Burkholderia/genética , Burkholderia/crescimento & desenvolvimento , Burkholderia/isolamento & purificação , DNA Bacteriano/genética , DNA Ribossômico/genética , Concentração de Íons de Hidrogênio , Ácidos Indolacéticos/metabolismo , Ácidos Indolacéticos/farmacologia , Lycopodium/química , Microscopia Eletrônica de Varredura , Dados de Sequência Molecular , Micorrizas , Fatores de Crescimento Neural , Fixação de Nitrogênio , Fosfatos/química , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/microbiologia , RNA Ribossômico 16S/genética , Sideróforos/biossíntese , Microbiologia do Solo
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