Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 225
Filtrar
1.
Physiol Genomics ; 2019 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-31588872

RESUMO

The effects of exercise training on the skeletal muscle (SKM) lipidome and mitochondrial function have not been thoroughly explored in individuals with type 2 diabetes (T2D). We hypothesize that 10 weeks of supervised endurance training improves SKM mitochondrial function and insulin sensitivity that are related to alterations in lipid signatures within SKM of T2D (males n=8). We employed integrated multi-omics data analyses including ex vivo lipidomics [MS/MS-shotgun] and transcriptomics [RNAseq]. From biopsies of SKM, tissue and primary myotubes mitochondrial respiration were quantified by high resolution respirometry. We also performed hyperinsulinemic-euglycemic clamps and blood draws before and after the training. The lipidomics analysis revealed that endurance training (>95% compliance) increased monolysocardiolipin by 68.2 % (MLCL, p ≤ 0.03), a putative marker of mitochondrial remodeling and reduced total sphingomyelin by 44.8 % (SM, p ≤ 0.05) and phosphatidylserine by 39.7 % (PS, ≤ 0.04), and tended to reduce ceramides lipid content by 19.8 %. Endurance training also improved intrinsic mitochondrial respiration in SKM of T2D without alterations in mitochondrial DNA copy number or cardiolipin content. RNAseq revealed 71 transcripts in SKM of T2D that were differentially regulated. Insulin sensitivity was unaffected and HbA1c levels moderately increased by 7.3 % despite an improvement in cardiorespiratory fitness (VO2peak) following the training intervention. In summary, endurance training improves intrinsic and cell-autonomous SKM mitochondrial function and modifies lipid composition in men with T2D independent of alterations in insulin sensitivity and glycemic control.

2.
Sci Data ; 6(1): 212, 2019 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-31624257

RESUMO

Alzheimer's disease (AD) is the most common cause of dementia. The mechanism of disease development and progression is not well understood, but increasing evidence suggests multifactorial etiology, with a number of genetic, environmental, and aging-related factors. There is a growing body of evidence that metabolic defects may contribute to this complex disease. To interrogate the relationship between system level metabolites and disease susceptibility and progression, the AD Metabolomics Consortium (ADMC) in partnership with AD Neuroimaging Initiative (ADNI) is creating a comprehensive biochemical database for patients in the ADNI1 cohort. We used the Biocrates Bile Acids platform to evaluate the association of metabolic levels with disease risk and progression. We detail the quantitative metabolomics data generated on the baseline samples from ADNI1 and ADNIGO/2 (370 cognitively normal, 887 mild cognitive impairment, and 305 AD). Similar to our previous reports on ADNI1, we present the tools for data quality control and initial analysis. This data descriptor represents the third in a series of comprehensive metabolomics datasets from the ADMC on the ADNI.

3.
Artigo em Inglês | MEDLINE | ID: mdl-31479303

RESUMO

Skeletal muscle atrophy is a clinically important outcome of disuse due to injury, immobilization and bed rest. Disuse atrophy is accompanied by mitochondrial dysfunction which likely contributes to activation of the muscle atrophy program. However, the linkage of muscle mass and mitochondrial energetics, during disuse atrophy and its recovery is incompletely understood. Transcriptomic analysis of muscle biopsies from healthy older adults subject to complete bed rest revealed marked inhibition of mitochondrial energy metabolic pathways. To determine the temporal sequence of muscle atrophy, and changes in intramyocellular lipid and mitochondrial energetics, we conducted a time course of hind limb unloading induced atrophy in adult mice. Mitochondrial respiration and calcium retention capacity were diminished while H2O2emission was increased in as soon as 3 days of unloading, prior to significant muscle atrophy. These changes were associated with a decrease in total cardiolipin and profound changes in remodeled cardiolipin species. Hindlimb unloading performed in muscle-specific PGC-1a/bknockout mice, a model of mitochondrial dysfunction, did not affect muscle atrophy but impacted muscle function. These data suggest early mitochondrial remodeling affects muscle function but not mass during disuse atrophy. Early alterations in mitochondrial energetics and lipid remodeling may represent novel targets to prevent muscle functional impairment caused by disuse and to enhance recovery from periods of muscle atrophy.

4.
Oral Dis ; 2019 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-31541581

RESUMO

Growing evidence indicates that oral health and brain health are interconnected. Declining cognition and dementia coincide with lack of self-preservation, including oral hygiene. The oral microbiota plays an important role in maintaining oral health. Emerging evidence suggests a link between oral dysbiosis and cognitive decline in patients with Alzheimer's disease. This review showcases the recent advances connecting oral health and cognitive function during aging and the potential utility of oral-derived biospecimens to inform on brain health. Collectively, experimental findings indicate that the connection between oral health and cognition cannot be underestimated; moreover, oral biospecimens are abundant and readily obtainable without invasive procedures, which may help inform on cognitive health.

5.
Gut ; 2019 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-31462556

RESUMO

OBJECTIVE: Insulinomas and non-functional pancreatic neuroendocrine tumours (NF-PanNETs) have distinctive clinical presentations but share similar pathological features. Their genetic bases have not been comprehensively compared. Herein, we used whole-genome/whole-exome sequencing (WGS/WES) to identify genetic differences between insulinomas and NF-PanNETs. DESIGN: The mutational profiles and copy-number variation (CNV) patterns of 211 PanNETs, including 84 insulinomas and 127 NF-PanNETs, were obtained from WGS/WES data provided by Peking Union Medical College Hospital and the International Cancer Genome Consortium. Insulinoma RNA sequencing and immunohistochemistry data were assayed. RESULTS: PanNETs were categorised based on CNV patterns: amplification, copy neutral and deletion. Insulinomas had CNV amplifications and copy neutral and lacked CNV deletions. CNV-neutral insulinomas exhibited an elevated rate of YY1 mutations. In contrast, NF-PanNETs had all three CNV patterns, and NF-PanNETs with CNV deletions had a high rate of loss-of-function mutations of tumour suppressor genes. NF-PanNETs with CNV alterations (amplification and deletion) had an elevated risk of relapse, and additional DAXX/ATRX mutations could predict an increased relapse risk in the first 2-year period. CONCLUSION: These WGS/WES data allowed a comprehensive assessment of genetic differences between insulinomas and NF-PanNETs, reclassifying these tumours into novel molecular subtypes. We also proposed a novel relapse risk stratification system using CNV patterns and DAXX/ATRX mutations.

6.
JAMA Netw Open ; 2(7): e197978, 2019 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-31365104

RESUMO

Importance: Increasing evidence suggests an important role of liver function in the pathophysiology of Alzheimer disease (AD). The liver is a major metabolic hub; therefore, investigating the association of liver function with AD, cognition, neuroimaging, and CSF biomarkers would improve the understanding of the role of metabolic dysfunction in AD. Objective: To examine whether liver function markers are associated with cognitive dysfunction and the "A/T/N" (amyloid, tau, and neurodegeneration) biomarkers for AD. Design, Setting, and Participants: In this cohort study, serum-based liver function markers were measured from September 1, 2005, to August 31, 2013, in 1581 AD Neuroimaging Initiative participants along with cognitive measures, cerebrospinal fluid (CSF) biomarkers, brain atrophy, brain glucose metabolism, and amyloid-ß accumulation. Associations of liver function markers with AD-associated clinical and A/T/N biomarkers were assessed using generalized linear models adjusted for confounding variables and multiple comparisons. Statistical analysis was performed from November 1, 2017, to February 28, 2019. Exposures: Five serum-based liver function markers (total bilirubin, albumin, alkaline phosphatase, alanine aminotransferase, and aspartate aminotransferase) from AD Neuroimaging Initiative participants were used as exposure variables. Main Outcomes and Measures: Primary outcomes included diagnosis of AD, composite scores for executive functioning and memory, CSF biomarkers, atrophy measured by magnetic resonance imaging, brain glucose metabolism measured by fludeoxyglucose F 18 (18F) positron emission tomography, and amyloid-ß accumulation measured by [18F]florbetapir positron emission tomography. Results: Participants in the AD Neuroimaging Initiative (n = 1581; 697 women and 884 men; mean [SD] age, 73.4 [7.2] years) included 407 cognitively normal older adults, 20 with significant memory concern, 298 with early mild cognitive impairment, 544 with late mild cognitive impairment, and 312 with AD. An elevated aspartate aminotransferase (AST) to alanine aminotransferase (ALT) ratio and lower levels of ALT were associated with AD diagnosis (AST to ALT ratio: odds ratio, 7.932 [95% CI, 1.673-37.617]; P = .03; ALT: odds ratio, 0.133 [95% CI, 0.042-0.422]; P = .004) and poor cognitive performance (AST to ALT ratio: ß [SE], -0.465 [0.180]; P = .02 for memory composite score; ß [SE], -0.679 [0.215]; P = .006 for executive function composite score; ALT: ß [SE], 0.397 [0.128]; P = .006 for memory composite score; ß [SE], 0.637 [0.152]; P < .001 for executive function composite score). Increased AST to ALT ratio values were associated with lower CSF amyloid-ß 1-42 levels (ß [SE], -0.170 [0.061]; P = .04) and increased amyloid-ß deposition (amyloid biomarkers), higher CSF phosphorylated tau181 (ß [SE], 0.175 [0.055]; P = .02) (tau biomarkers) and higher CSF total tau levels (ß [SE], 0.160 [0.049]; P = .02) and reduced brain glucose metabolism (ß [SE], -0.123 [0.042]; P = .03) (neurodegeneration biomarkers). Lower levels of ALT were associated with increased amyloid-ß deposition (amyloid biomarkers), and reduced brain glucose metabolism (ß [SE], 0.096 [0.030]; P = .02) and greater atrophy (neurodegeneration biomarkers). Conclusions and Relevance: Consistent associations of serum-based liver function markers with cognitive performance and A/T/N biomarkers for AD highlight the involvement of metabolic disturbances in the pathophysiology of AD. Further studies are needed to determine if these associations represent a causative or secondary role. Liver enzyme involvement in AD opens avenues for novel diagnostics and therapeutics.

7.
Cell Biol Toxicol ; 2019 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-31468290

RESUMO

The article Is the clinical lipidomics a potential goldmine?, written by Linlin Zhang, Xianlin Han and Xiangdong Wang, was originally published electronically on the publisher's internet portal (currently SpringerLink) on 21 July 2018 with open access. With the author(s)' decision to step.

8.
JCI Insight ; 52019 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-31287806

RESUMO

Obesity-related insulin resistance is associated with intramyocellular lipid accumulation in skeletal muscle. We hypothesized that in contrast to current dogma, this linkage is related to an upstream mechanism that coordinately regulates both processes. We demonstrate that the muscle-enriched transcription factor MondoA is glucose/fructose responsive in human skeletal myotubes and directs the transcription of genes in cellular metabolic pathways involved in diversion of energy substrate from a catabolic fate into nutrient storage pathways including fatty acid desaturation and elongation, triacylglyeride (TAG) biosynthesis, glycogen storage, and hexosamine biosynthesis. MondoA also reduces myocyte glucose uptake by suppressing insulin signaling. Mice with muscle-specific MondoA deficiency were partially protected from insulin resistance and muscle TAG accumulation in the context of diet-induced obesity. These results identify MondoA as a nutrient-regulated transcription factor that under normal physiological conditions serves a dynamic checkpoint function to prevent excess energy substrate flux into muscle catabolic pathways when myocyte nutrient balance is positive. However, in conditions of chronic caloric excess, this mechanism becomes persistently activated leading to progressive myocyte lipid storage and insulin resistance.

9.
Proteomics ; : e1900070, 2019 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-31291508

RESUMO

Direct infusion-based shotgun lipidomics is one of the most powerful and useful tools in comprehensive analysis of lipid species from lipid extracts of various biological samples with high accuracy/precision. However, despite many advantages, the classical shotgun lipidomics suffers some general dogmas of limitations, such as ion suppression, ambiguous identification of isobaric/isomeric lipid species, and ion source-generated artifacts, restraining the applications in analysis of low-abundance lipid species, particularly those less ionizable or isomers that yield almost identical fragmentation patterns. This article reviews the strategies (such as modifier addition, prefractionation, chemical derivatization, charge feature utilization) that have been employed to improve/eliminate these limitations in modern shotgun lipidomics approaches (e.g., high mass resolution mass spectrometry-based and multidimensional mass spectrometry-based shotgun lipidomics). Therefore, with the enhancement of these strategies for shotgun lipidomics, comprehensive analysis of lipid species including isomeric/isobaric species is achieved in a more accurate and effective manner, greatly substantiating the aberrant lipid metabolism, signaling trafficking, and homeostasis under pathological conditions.

10.
Endocrine ; 65(3): 524-530, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31292840

RESUMO

PURPOSE: Long-standing hypoglycemia can cause cognitive impairment, and whether recurrent severe hypoglycemia impacts cognitive function in patients with insulinoma has not been studied. This study focused on exploring the cognitive function in patients with insulinoma. METHODS: A prospective study was conducted to assess cognitive function in patients with insulinoma by administering the Montreal Cognitive Assessment (MoCA) questionnaire between January 2016 and July 2017, and patients with cognitive impairment were followed up to undergo the MoCA test 1 year after surgery. The MoCA scores after surgery were compared with the scores before surgery, and the associations between cognitive impairment and relevant factors were further evaluated by multiple linear regression analysis. RESULTS: Eighteen out of thirty-four patients (53%) with insulinoma were screened positive for cognitive impairment as defined by a MoCA score <26. Performance in certain cognitive domains, including visuospatial and executive functions, delayed memory, attention, language, and abstraction, was significantly worse in patients with cognitive impairment. Multivariate analysis indicated that MoCA scores correlated significantly with tumor grade and years of education. Eight patients with cognitive impairment were lost to follow-up. The remaining ten patients with cognitive impairment showed improvements 1 year postoperatively, and seven patients recovered to normal cognitive function. CONCLUSIONS: Cognitive impairment was found in patients with insulinoma and was reversible in some patients 1 year after surgery. More studies are needed to explore the underlying mechanisms of the existence and reversibility of cognitive impairment in patients with insulinoma.

11.
Nat Immunol ; 20(6): 765-767, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31048759

RESUMO

In the version of this article initially published, two arrows in the far right plot of Fig. 3c were aimed incorrectly, and the error bars were missing in Fig. 6e,f. In Fig. 3c, the arrow labeled '5-LOX' should be aimed at the plot measuring LXB4, and the arrow labeled 'LTA4H' should be aimed at the plot measuring LTB4. The errors have been corrected in the HTML and PDF versions of the article.

12.
Nat Immunol ; 20(5): 626-636, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30936495

RESUMO

Muscle damage elicits a sterile immune response that facilitates complete regeneration. Here, we used mass spectrometry-based lipidomics to map the mediator lipidome during the transition from inflammation to resolution and regeneration in skeletal muscle injury. We observed temporal regulation of glycerophospholipids and production of pro-inflammatory lipid mediators (for example, leukotrienes and prostaglandins) and specialized pro-resolving lipid mediators (for example, resolvins and lipoxins) that were modulated by ibuprofen. These time-dependent profiles were recapitulated in sorted neutrophils and Ly6Chi and Ly6Clo muscle-infiltrating macrophages, with a distinct pro-resolving signature observed in Ly6Clo macrophages. RNA sequencing of macrophages stimulated with resolvin D2 showed similarities to transcriptional changes found during the temporal transition from Ly6Chi macrophage to Ly6Clo macrophage. In vivo, resolvin D2 increased Ly6Clo macrophages and functional improvement of the regenerating muscle. These results reveal dynamic lipid mediator signatures of innate immune cells and provide a proof of concept for their exploitable effector roles in muscle regeneration.


Assuntos
Mediadores da Inflamação/imunologia , Lipídeos/imunologia , Macrófagos/imunologia , Músculo Esquelético/imunologia , Regeneração/imunologia , Animais , Ácidos Docosa-Hexaenoicos/imunologia , Ácidos Docosa-Hexaenoicos/farmacologia , Expressão Gênica/efeitos dos fármacos , Expressão Gênica/imunologia , Perfilação da Expressão Gênica , Ontologia Genética , Sequenciamento de Nucleotídeos em Larga Escala , Metabolismo dos Lipídeos/imunologia , Lipídeos/análise , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Músculo Esquelético/lesões , Músculo Esquelético/fisiopatologia , Regeneração/genética
13.
J Lipid Res ; 60(5): 937-952, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30862696

RESUMO

High-fat diet (HFD) causes renal lipotoxicity that is ameliorated with AMP-activated protein kinase (AMPK) activation. Although bioactive eicosanoids increase with HFD and are essential in regulation of renal disease, their role in the inflammatory response to HFD-induced kidney disease and their modulation by AMPK activation remain unexplored. In a mouse model, we explored the effects of HFD on eicosanoid synthesis and the role of AMPK activation in ameliorating these changes. We used targeted lipidomic profiling with quantitative MS to determine PUFA and eicosanoid content in kidneys, urine, and renal arterial and venous circulation. HFD increased phospholipase expression as well as the total and free pro-inflammatory arachidonic acid (AA) and anti-inflammatory DHA in kidneys. Consistent with the parent PUFA levels, the AA- and DHA-derived lipoxygenase (LOX), cytochrome P450, and nonenzymatic degradation (NE) metabolites increased in kidneys with HFD, while EPA-derived LOX and NE metabolites decreased. Conversely, treatment with 5-aminoimidazole-4-carboxamide-1-ß-D-furanosyl 5'-monophosphate (AICAR), an AMPK activator, reduced the free AA and DHA content and the DHA-derived metabolites in kidney. Interestingly, kidney and circulating AA, AA metabolites, EPA-derived LOX, and NE metabolites are increased with HFD; whereas, DHA metabolites are increased in kidney in contrast to their decreased circulating levels with HFD. Together, these changes showcase HFD-induced pro- and anti-inflammatory eicosanoid dysregulation and highlight the role of AMPK in correcting HFD-induced dysregulated eicosanoid pathways.

14.
Anal Chim Acta ; 1061: 28-41, 2019 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-30926037

RESUMO

The mainstream of lipidomics involves mass spectrometry-based, systematic, and large-scale studies of the structure, composition, and quantity of lipids in biological systems such as organs, cells, and body fluids. As increasingly more researchers in broad fields are beginning to pay attention to and actively learn about the lipidomic technology, some introduction on the topic is needed to help the newcomers to better understand the field. This tutorial seeks to introduce the basic knowledge about lipidomics and to provide readers with some core ideas and the most important approaches for studying the field.


Assuntos
Lipídeos/química , Biologia Computacional , Humanos , Espectrometria de Massas
15.
Cell Mol Gastroenterol Hepatol ; 7(4): 763-781, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30831319

RESUMO

BACKGROUND & AIMS: Obesity promotes the development of nonalcoholic fatty liver diseases (NAFLDs), yet not all obese patients develop NAFLD. The underlying causes for this discrepancy remain elusive. LPGAT1 is an acyltransferase that catalyzes the remodeling of phosphatidylglycerol (PG), a mitochondrial phospholipid implicated in various metabolic diseases. Here, we investigated the role of LPGAT1 in regulating the onset of diet-induced obesity and its related hepatosteatosis because polymorphisms of the LPGAT1 gene promoter were strongly associated with susceptibility to obesity in Pima Indians. METHODS: Mice with whole-body knockout of LPGAT1 were generated to investigate the role of PG remodeling in NAFLD. RESULTS: LPGAT1 deficiency protected mice from diet-induced obesity, but led to hepatopathy, insulin resistance, and NAFLD as a consequence of oxidative stress, mitochondrial DNA depletion, and mitochondrial dysfunction. CONCLUSIONS: This study identified an unexpected role of PG remodeling in obesity, linking mitochondrial dysfunction to NAFLD.

16.
Nat Commun ; 10(1): 1432, 2019 03 29.
Artigo em Inglês | MEDLINE | ID: mdl-30926815

RESUMO

Of the four separate PE biosynthetic pathways in eukaryotes, one occurs in the mitochondrial inner membrane (IM) and is executed by phosphatidylserine decarboxylase (Psd1). Deletion of Psd1 is lethal in mice and compromises mitochondrial function. We hypothesize that this reflects inefficient import of non-mitochondrial PE into the IM. Here, we test this by re-wiring PE metabolism in yeast by re-directing Psd1 to the outer mitochondrial membrane or the endomembrane system and show that PE can cross the IMS in both directions. Nonetheless, PE synthesis in the IM is critical for cytochrome bc1 complex (III) function and mutations predicted to disrupt a conserved PE-binding site in the complex III subunit, Qcr7, impair complex III activity similar to PSD1 deletion. Collectively, these data challenge the current dogma of PE trafficking and demonstrate that PE made in the IM by Psd1 support the intrinsic functionality of complex III.


Assuntos
Complexo III da Cadeia de Transporte de Elétrons/metabolismo , Membranas Mitocondriais/metabolismo , Fosfatidiletanolaminas/metabolismo , Saccharomyces cerevisiae/metabolismo , Aerobiose , Complexo IV da Cadeia de Transporte de Elétrons/metabolismo , Retículo Endoplasmático/metabolismo , Retículo Endoplasmático/ultraestrutura , Membranas Mitocondriais/ultraestrutura , Mutação/genética , Reprodutibilidade dos Testes , Saccharomyces cerevisiae/ultraestrutura , Proteínas de Saccharomyces cerevisiae/metabolismo
17.
J Enzyme Inhib Med Chem ; 34(1): 150-162, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30427217

RESUMO

A series of new Olaparib derivatives was designed and synthesized, and their inhibitory activities against poly (ADP-ribose) polymerases-1 (PARP-1) enzyme and cancer cell line MDA-MB-436 in vitro were evaluated. The results showed that compound 5l exhibited the most potent inhibitory effects on PARP-1 enzyme (16.10 ± 1.25 nM) and MDA-MB-436 cancer cell (11.62 ± 2.15 µM), which was close to that of Olaparib. As a PARP-1 inhibitor had been reported to be viable to neuroprotection, in order to search for new multitarget-directed ligands (MTDLs) for the treatment of Alzheimer's disease (AD), the inhibitory activities of the synthesized compounds against the enzymes AChE (from electric eel) and BChE (from equine serum) were also tested. Compound 5l displayed moderate BChE inhibitory activity (9.16 ± 0.91 µM) which was stronger than neostigmine (12.01 ± 0.45 µM) and exhibited selectivity for BChE over AChE to some degree. Molecular docking studies indicated that 5l could bind simultaneously to the catalytic active of PARP-1, but it could not interact well with huBChE. For pursuit of PARP-1 and BChE dual-targeted inhibitors against AD, small and flexible non-polar groups introduced to the compound seemed to be conducive to improving its inhibitory potency on huBChE, while keeping phthalazine-1-one moiety unchanged which was mainly responsible for PARP-1 inhibitory activity. Our research gave a clue to search for new agents based on AChE and PARP-1 dual-inhibited activities to treat Alzheimer's disease.


Assuntos
Acetilcolinesterase/metabolismo , Antineoplásicos/farmacologia , Inibidores da Colinesterase/farmacologia , Simulação de Acoplamento Molecular , Ftalazinas/química , Ftalazinas/farmacologia , Piperazinas/química , Piperazinas/farmacologia , Poli(ADP-Ribose) Polimerase-1/antagonistas & inibidores , Animais , Antineoplásicos/síntese química , Antineoplásicos/química , Butirilcolinesterase/metabolismo , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Inibidores da Colinesterase/síntese química , Inibidores da Colinesterase/química , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Electrophorus , Cavalos , Humanos , Estrutura Molecular , Ftalazinas/síntese química , Piperazinas/síntese química , Poli(ADP-Ribose) Polimerase-1/metabolismo , Relação Estrutura-Atividade
18.
Cell Rep ; 25(12): 3283-3298.e6, 2018 12 18.
Artigo em Inglês | MEDLINE | ID: mdl-30566857

RESUMO

Accumulation of visceral adiposity is directly linked to the morbidity of obesity, while subcutaneous body fat is considered more benign. We have identified an unexpected role for B cell lymphoma 6 (BCL6), a critical regulator of immunity, in the developmental expansion of subcutaneous adipose tissue. In adipocyte-specific knockout mice (Bcl6AKO), we found that Bcl6 deletion results in strikingly increased inguinal, but not perigonadal, adipocyte size and tissue mass in addition to marked insulin sensitivity. Genome-wide RNA expression and DNA binding analyses revealed that BCL6 controls gene networks involved in cell growth and fatty acid biosynthesis. Using deuterium label incorporation and comprehensive adipokine and lipid profiling, we discovered that ablation of adipocyte Bcl6 enhances subcutaneous adipocyte lipogenesis, increases levels of adiponectin and fatty acid esters of hydroxy fatty acids (FAHFAs), and prevents steatosis. Thus, our studies identify BCL6 as a negative regulator of subcutaneous adipose tissue expansion and metabolic health.

19.
Proc Natl Acad Sci U S A ; 115(52): E12228-E12234, 2018 12 26.
Artigo em Inglês | MEDLINE | ID: mdl-30530672

RESUMO

There is a growing appreciation for a fundamental connection between lipid metabolism and the immune response. Macrophage phagocytosis is a signature innate immune response to pathogen exposure, and cytoplasmic membrane expansion is required to engulf the phagocytic target. The sterol regulatory element binding proteins (SREBPs) are key transcriptional regulatory proteins that sense the intracellular lipid environment and modulate expression of key genes of fatty acid and cholesterol metabolism to maintain lipid homeostasis. In this study, we show that TLR4-dependent stimulation of macrophage phagocytosis requires mTORC1-directed SREBP-1a-dependent lipid synthesis. We also show that the phagocytic defect in macrophages from SREBP-1a-deficient mice results from decreased interaction between membrane lipid rafts and the actin cytoskeleton, presumably due to reduced accumulation of newly synthesized fatty acyl chains within major membrane phospholipids. We show that mTORC1-deficient macrophages also have a phagocytic block downstream from TLR4 signaling, and, interestingly, the reduced level of phagocytosis in both SREBP-1a- and mTORC1-deficient macrophages can be restored by ectopic SREBP-1a expression. Taken together, these observations indicate SREBP-1a is a major downstream effector of TLR4-mTORC1 directed interactions between membrane lipid rafts and the actin cytoskeleton that are required for pathogen-stimulated phagocytosis in macrophages.


Assuntos
Lipídeos/biossíntese , Macrófagos/metabolismo , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Fagocitose , Proteína de Ligação a Elemento Regulador de Esterol 1/metabolismo , Receptor 4 Toll-Like/metabolismo , Animais , Células Cultivadas , Alvo Mecanístico do Complexo 1 de Rapamicina/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteína de Ligação a Elemento Regulador de Esterol 1/genética , Receptor 4 Toll-Like/genética
20.
Genes (Basel) ; 9(11)2018 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-30400254

RESUMO

Cardiovascular disease (CVD) and type 2 diabetes (T2D) are increasing worldwide. This is mainly due to an unhealthy nutrition, implying that variation in CVD risk may be due to variation in the capacity to manage a nutritional load. We examined the genomic basis of postprandial metabolism. Our main purpose was to introduce the GEMM Family Study (Genetics of Metabolic Diseases in Mexico) as a multi-center study carrying out an ongoing recruitment of healthy urban adults. Each participant received a mixed meal challenge and provided a 5-hours' time course series of blood, buffy coat specimens for DNA isolation, and adipose tissue (ADT)/skeletal muscle (SKM) biopsies at fasting and 3 h after the meal. A comprehensive profiling, including metabolomic signatures in blood and transcriptomic and proteomic profiling in SKM and ADT, was performed to describe tendencies for variation in postprandial response. Our data generation methods showed preliminary trends indicating that by characterizing the dynamic properties of biomarkers with metabolic activity and analyzing multi-OMICS data it could be possible, with this methodology and research design, to identify early trends for molecular biology systems and genes involved in the fasted and fed states.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA