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1.
Wei Sheng Yan Jiu ; 49(5): 785-822, 2020 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-33070825

RESUMO

OBJECTIVE: Establish the prokaryotic expression system of Amuc_1100 protein from Akkermansia muciniphila, and analyze the effects of this protein on the body weight, blood glucose, intestinal barrier function and Akkermansia muciniphila abundance in rats fed with high-fat diet combined streptozotocin(STZ)injection. METHODS: PCR product of Amuc_1100 Gene(Gene ID: 34174504) was linked to the double enzyme-digested pET-26 b plasmid vector. The recombinant expression plasmid pET-26 b-Amuc_1100 then transformed into E. Coli BL21. The verified clones through sequence analysis were induced by the addition of IPTG. High-fat diet rats were interfered with the purified protein at high and low doses. The changes of body weight, blood glucose, intestinal barrier function and Akkermansia muciniphila abundance were analyzed. RESULTS: The recombinant expression plasmid pET-26 b-Amuc_1100 was successfully constructed. The sequencing result showed 100% similarity to the Amuc_1100 gene in GenBank. The molecular weight of the protein obtained was 42 kDa. The intervention of Amuc_1100 protein can reduce the weight of rats fed with high-fat diet combined STZ injection to some extent, improve barrier function and increase the abundance of Akkermansia muciniphila in intestine. CONCLUSION: The prokaryotic expression system of Amuc_1100 protein was successfully constructed, which has a certain regulatory effect on rats fed with high-fat diet combined STZ injection.


Assuntos
Dieta Hiperlipídica , Escherichia coli , Animais , Dieta Hiperlipídica/efeitos adversos , Escherichia coli/genética , Ratos , Estreptozocina/toxicidade , Verrucomicrobia
2.
Nat Commun ; 11(1): 4981, 2020 10 05.
Artigo em Inglês | MEDLINE | ID: mdl-33020469

RESUMO

Antagonism or agonism of the glucose-dependent insulinotropic polypeptide (GIP) receptor (GIPR) prevents weight gain and leads to dramatic weight loss in combination with glucagon-like peptide-1 receptor agonists in preclinical models. Based on the genetic evidence supporting GIPR antagonism, we previously developed a mouse anti-murine GIPR antibody (muGIPR-Ab) that protected diet-induced obese (DIO) mice against body weight gain and improved multiple metabolic parameters. This work reconciles the similar preclinical body weight effects of GIPR antagonists and agonists in vivo, and here we show that chronic GIPR agonism desensitizes GIPR activity in primary adipocytes, both differentiated in vitro and adipose tissue in vivo, and functions like a GIPR antagonist. Additionally, GIPR activity in adipocytes is partially responsible for muGIPR-Ab to prevent weight gain in DIO mice, demonstrating a role of adipocyte GIPR in the regulation of adiposity in vivo.


Assuntos
Adipócitos/efeitos dos fármacos , Fármacos Antiobesidade/farmacologia , Receptores dos Hormônios Gastrointestinais/agonistas , Receptores dos Hormônios Gastrointestinais/antagonistas & inibidores , Adipócitos/metabolismo , Tecido Adiposo/efeitos dos fármacos , Tecido Adiposo/metabolismo , Animais , Fármacos Antiobesidade/química , Fármacos Antiobesidade/uso terapêutico , Anticorpos/farmacologia , Anticorpos/uso terapêutico , Peso Corporal/efeitos dos fármacos , Membrana Celular/metabolismo , Células Cultivadas , AMP Cíclico/metabolismo , Dieta Hiperlipídica/efeitos adversos , Ácidos Graxos/metabolismo , Polipeptídeo Inibidor Gástrico/farmacologia , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Obesidade/tratamento farmacológico , Obesidade/metabolismo , Obesidade/patologia , Receptores dos Hormônios Gastrointestinais/deficiência , Receptores dos Hormônios Gastrointestinais/metabolismo
3.
Zhong Nan Da Xue Xue Bao Yi Xue Ban ; 45(8): 892-900, 2020 Aug 28.
Artigo em Inglês, Chinês | MEDLINE | ID: mdl-33053529

RESUMO

OBJECTIVES: To investigate the effects of environmental enrichment on cognitive behavior and the expression of adenosine triphosphate binding cassette transporter A7 (ABCA7) in hippocampus of the adolescent mice with high fat diet. METHODS: A total of healthy 3-week-old male C57BL/6J mice were randomly divided into 3 groups: a control (Con) group, a high fat diet (HFD) group, and a high fat diet+environmental enrichment (HFD+EE) group, with 10 mice in each group. The Con group was given normal diet. The HFD group was given high fat diet. The HFD+EE group was given high fat diet; at the same time, they treated by environmental enrichment. After 10 weeks, open field test was used to detect activity. Novel object recognition test and Y maze test were used to detect cognitive behavior. After the test, the brain was collected and used to detect the protein expression of ABCA7 in the hippocampus by immunohistochemistry and Western blotting. And quantitative RT-PCR (RT-qPCR) was used to detect the ABCA7 mRNA expression level in the hippocampus. RESULTS: There was no significant difference in the total movement distance in the mice among the 3 groups (P>0.05). In the novel object recognition test, the discrimination index of the HFD group was much lower than that of the Con group, and the difference was significant (P<0.01). The discrimination index of the HFD+EE group was higher than that of the HFD group, and the difference was significant (P<0.01). In the Y maze test, there was no significant difference in the percentage of time spent on the new arm among the mice in the 3 groups (P=0.1279). The percentage of entries in new arm in the HFD group was much lower than that in the Con group, and the difference was significant (P<0.01). The percentage of the entries in new arm in the HFD+EE group was significantly higher than that in the HFD group (P<0.05). The results of immunohistochemistry showed that ABCA7 was positively expressed in the cytoplasm of hippocampal neurons in the mice from these 3 groups, and the expression of ABCA7 in the hippocampus of the HFD group was lower than that of the Con group (CA1: P<0.01, CA3: P=0.06), while the expression of ABCA7 in hippocampus of HFD+EE group was higher than that of HFD group (CA1: P=0.23, CA3: P<0.05). Western blotting results showed that compared with the Con group, the protein level of ABCA7 in the hippocampus of the HFD group was significantly reduced (P<0.05), while compared with the Con group, the protein level of ABCA7 in the hippocampus of the HFD+EE group showed an upward trend (P=0.06). The results of RT-qPCR showed that the mRNA level of ABCA7 in the hippocampus of HFD group was significantly lower than that of the Con group (P<0.01), while the mRNA level of ABCA7 in the hippocampus of HFD+EE group was significantly higher than that of the HFD group (P<0.01). CONCLUSIONS: High fat diet in adolescent can impair cognitive function with a decrease in the expression of ABCA7 in hippocampus, which can be ameliorate by environmental enrichment.


Assuntos
Transportadores de Cassetes de Ligação de ATP , Trifosfato de Adenosina , Dieta Hiperlipídica , Hipocampo , Animais , Cognição , Dieta Hiperlipídica/efeitos adversos , Hipocampo/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL
4.
Nat Commun ; 11(1): 4737, 2020 09 23.
Artigo em Inglês | MEDLINE | ID: mdl-32968070

RESUMO

Innate immune signaling through the NLRP3 inflammasome is activated by multiple diabetes-related stressors, but whether targeting the inflammasome is beneficial for diabetes is still unclear. Nucleoside reverse-transcriptase inhibitors (NRTI), drugs approved to treat HIV-1 and hepatitis B infections, also block inflammasome activation. Here, we show, by analyzing five health insurance databases, that the adjusted risk of incident diabetes is 33% lower in patients with NRTI exposure among 128,861 patients with HIV-1 or hepatitis B (adjusted hazard ratio for NRTI exposure, 0.673; 95% confidence interval, 0.638 to 0.710; P < 0.0001; 95% prediction interval, 0.618 to 0.734). Meanwhile, an NRTI, lamivudine, improves insulin sensitivity and reduces inflammasome activation in diabetic and insulin resistance-induced human cells, as well as in mice fed with high-fat chow; mechanistically, inflammasome-activating short interspersed nuclear element (SINE) transcripts are elevated, whereas SINE-catabolizing DICER1 is reduced, in diabetic cells and mice. These data suggest the possibility of repurposing an approved class of drugs for prevention of diabetes.


Assuntos
Diabetes Mellitus Tipo 2/tratamento farmacológico , Reposicionamento de Medicamentos , Inflamassomos/efeitos dos fármacos , Resistência à Insulina , Inibidores da Transcriptase Reversa/farmacologia , Adipócitos/metabolismo , Animais , Sobrevivência Celular , RNA Helicases DEAD-box/metabolismo , Diabetes Mellitus Tipo 2/prevenção & controle , Dieta Hiperlipídica/efeitos adversos , HIV-1/efeitos dos fármacos , Hepatite B , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Células Musculares/metabolismo , Ribonuclease III/metabolismo
5.
Nat Commun ; 11(1): 4458, 2020 09 07.
Artigo em Inglês | MEDLINE | ID: mdl-32895383

RESUMO

In rodent models of type 2 diabetes (T2D), sustained remission of hyperglycemia can be induced by a single intracerebroventricular (icv) injection of fibroblast growth factor 1 (FGF1), and the mediobasal hypothalamus (MBH) was recently implicated as the brain area responsible for this effect. To better understand the cellular response to FGF1 in the MBH, we sequenced >79,000 single-cell transcriptomes from the hypothalamus of diabetic Lepob/ob mice obtained on Days 1 and 5 after icv injection of either FGF1 or vehicle. A wide range of transcriptional responses to FGF1 was observed across diverse hypothalamic cell types, with glial cell types responding much more robustly than neurons at both time points. Tanycytes and ependymal cells were the most FGF1-responsive cell type at Day 1, but astrocytes and oligodendrocyte lineage cells subsequently became more responsive. Based on histochemical and ultrastructural evidence of enhanced cell-cell interactions between astrocytes and Agrp neurons (key components of the melanocortin system), we performed a series of studies showing that intact melanocortin signaling is required for the sustained antidiabetic action of FGF1. These data collectively suggest that hypothalamic glial cells are leading targets for the effects of FGF1 and that sustained diabetes remission is dependent on intact melanocortin signaling.


Assuntos
Diabetes Mellitus Experimental/dietoterapia , Diabetes Mellitus Tipo 2/tratamento farmacológico , Fator 1 de Crescimento de Fibroblastos/administração & dosagem , Hipoglicemiantes/administração & dosagem , Hipotálamo/efeitos dos fármacos , Proteínas Recombinantes/administração & dosagem , Proteína Relacionada com Agouti/metabolismo , Animais , Astrócitos/efeitos dos fármacos , Astrócitos/metabolismo , Glicemia/análise , Comunicação Celular , Núcleo Celular/efeitos dos fármacos , Núcleo Celular/metabolismo , Diabetes Mellitus Experimental/sangue , Diabetes Mellitus Experimental/etiologia , Diabetes Mellitus Experimental/patologia , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/etiologia , Diabetes Mellitus Tipo 2/patologia , Dieta Hiperlipídica/efeitos adversos , Sacarose na Dieta/administração & dosagem , Sacarose na Dieta/efeitos adversos , Humanos , Hipotálamo/citologia , Hipotálamo/patologia , Injeções Intraventriculares , Leptina/genética , Masculino , Melanocortinas/metabolismo , Hormônios Estimuladores de Melanócitos/administração & dosagem , Camundongos , Camundongos Knockout , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Oligodendroglia/efeitos dos fármacos , Oligodendroglia/metabolismo , RNA-Seq , Receptor Tipo 4 de Melanocortina/genética , Receptores de Melanocortina/antagonistas & inibidores , Receptores de Melanocortina/metabolismo , Indução de Remissão/métodos , Transdução de Sinais/efeitos dos fármacos , Análise de Célula Única , Técnicas Estereotáxicas , Transcriptoma/efeitos dos fármacos
6.
Am J Chin Med ; 48(6): 1409-1433, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32907360

RESUMO

Scutellaria baicalensis (SB), a herbal medicine, is commonly used to treat metabolic diseases, while Metformin (MF) is a widely used drug for type 2 diabetes. The purpose of this study was to investigate whether co-treatment of SB with MF could produce a potential therapeutic effect on high-fat and high-fructose diet (HFFD)-induced metabolic dysregulation. First, we optimized the dose of SB (100, 200, 400, and 800[Formula: see text]mg/kg) with MF (200[Formula: see text]mg/kg) in HFFD-induced C57BL6J mice. Next, the optimized dose of SB (400[Formula: see text]mg/kg) was co-administered with MF (50, 100, and 200[Formula: see text]mg/kg) in a similar animal model to find the effective combinations of SB and MF. Metabolic markers were determined in serum and tissues using different assays, histology, gene expression, and gut microbial population. The SB and MF co-treatment significantly decreased the body, liver, and VAT weights. The outcome of OGTT was improved, and the fasting insulin, HbA1c, TG, TC, LDL-c, AST, and ALT were decreased, while HDL-c was significantly increased. Histological analyses revealed maintained the integrity of liver, adipose tissue, and intestine prevented lipid accumulation in the liver and intestine and combated neuronal damage in the brain. Importantly, controlled the expression of PPAR[Formula: see text], and IL-6 genes in the liver, and expression of BDNF, Glut1, Glut3, and Glut4 genes in the brain. Treatment-specific gut microbial segregation was observed in the PCA chart. Our findings indicate that SB and MF co-treatment is an effective therapeutic approach for HFFD-induced metabolic dysregulation which is operated through the gut-liver-brain axis.


Assuntos
Encéfalo/metabolismo , Microbioma Gastrointestinal , Fígado/metabolismo , Doenças Metabólicas/tratamento farmacológico , Doenças Metabólicas/metabolismo , Metformina/administração & dosagem , Metformina/farmacologia , Fitoterapia , Extratos Vegetais/administração & dosagem , Extratos Vegetais/farmacologia , Animais , Fator Neurotrófico Derivado do Encéfalo/genética , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Dieta da Carga de Carboidratos/efeitos adversos , Dieta Hiperlipídica/efeitos adversos , Modelos Animais de Doenças , Quimioterapia Combinada , Transportador de Glucose Tipo 1/genética , Transportador de Glucose Tipo 1/metabolismo , Interleucina-6/genética , Interleucina-6/metabolismo , Masculino , Doenças Metabólicas/genética , Doenças Metabólicas/microbiologia , Camundongos Endogâmicos C57BL , PPAR gama/genética , PPAR gama/metabolismo
7.
Nat Commun ; 11(1): 4765, 2020 09 21.
Artigo em Inglês | MEDLINE | ID: mdl-32958780

RESUMO

Fatty acids (FAs) are essential nutrients, but how they are transported into cells remains unclear. Here, we show that FAs trigger caveolae-dependent CD36 internalization, which in turn delivers FAs into adipocytes. During the process, binding of FAs to CD36 activates its downstream kinase LYN, which phosphorylates DHHC5, the palmitoyl acyltransferase of CD36, at Tyr91 and inactivates it. CD36 then gets depalmitoylated by APT1 and recruits another tyrosine kinase SYK to phosphorylate JNK and VAVs to initiate endocytic uptake of FAs. Blocking CD36 internalization by inhibiting APT1, LYN or SYK abolishes CD36-dependent FA uptake. Restricting CD36 at either palmitoylated or depalmitoylated state eliminates its FA uptake activity, indicating an essential role of dynamic palmitoylation of CD36. Furthermore, blocking endocytosis by targeting LYN or SYK inhibits CD36-dependent lipid droplet growth in adipocytes and high-fat-diet induced weight gain in mice. Our study has uncovered a dynamic palmitoylation-regulated endocytic pathway to take up FAs.


Assuntos
Antígenos CD36/metabolismo , Endocitose/fisiologia , Ácidos Graxos/metabolismo , Lipoilação , Células 3T3-L1 , Aciltransferases/metabolismo , Adipócitos/metabolismo , Animais , Antígenos CD36/deficiência , Antígenos CD36/genética , Cavéolas/metabolismo , Células Cultivadas , Dieta Hiperlipídica/efeitos adversos , Humanos , Gotículas Lipídicas/metabolismo , Masculino , Proteínas de Membrana/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Mutação , Obesidade/tratamento farmacológico , Fosforilação , Transdução de Sinais , Quinase Syk/antagonistas & inibidores , Quinase Syk/metabolismo , Ganho de Peso/efeitos dos fármacos , Quinases da Família src/antagonistas & inibidores , Quinases da Família src/metabolismo
8.
Orv Hetil ; 161(35): 1456-1465, 2020 08.
Artigo em Húngaro | MEDLINE | ID: mdl-32822324

RESUMO

INTRODUCTION: Fatty liver can develop as a result of diseases, surgical procedures, medicaments, malnutrition or excessive alcohol consumption, however, fat and poor fiber feeding can be attributed as the primary cause. Non-alcoholic fatty liver can be found in 20-30% of the population. Generally, alimentary-induced fatty liver in early state is described as uncomplicated liver injury. AIM: The aim of our research was to study the effect of fat rich nutrition on the gut-liver axis by routine laboratory, analytical and histological methods in rats. METHODS: We also examined the redox parameters of the liver and of the bowel. Fatty acid composition and element content of liver were measured. RESULTS: Significant changes were found in parameters of redox homeostasis as well as alterations in liver enzymes and metabolites. The changes could be detected in the liver, blood and bowel parts. The development of fatty liver is associated with the decrease of transmethylation capacity. Fatty acid composition and metal ion homeostasis were also altered in liver. Histological examinations showed that hepatocytes were swollen in the central part of the liver lobules, showed droplets and pycnotic nuclei, which were characterized by fatty degeneration. Small and large bowel enterocytes were damaged, sometimes pushed from the surface, and sometimes inflammatory reactions in the mucous membrane were observed. CONCLUSION: Our results suggest that alimentary fatty liver in early state is not considered simply as a reversible alteration because it alters the entire body's redox homeostasis and establishes heart and serious metabolic diseases as well as hasten the development of gastrointestinal tumors. Orv Hetil. 2020; 161(35): 1456-1465.


Assuntos
Dieta Hiperlipídica , Inflamação/patologia , Fígado/patologia , Hepatopatia Gordurosa não Alcoólica , Animais , Ácidos Graxos , Hepatócitos , Intestinos/patologia , Síndrome Metabólica/complicações , Ratos
9.
PLoS One ; 15(8): e0234750, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32785220

RESUMO

The incidence of nonalcoholic steatohepatitis (NASH) is increasing worldwide, including in Asian countries. We reported that the hepatic expression of bile salt export pump (BSEP) was downregulated in patients with NASH, suggesting that BSEP is involved in the pathogenesis of NASH. To identify the underlying mechanism, we analyzed Bsep heterozygous knock-out (Bsep+/- mice) and wild-type (WT) C57BL/6J mice fed a high-fat diet (HFD) (32.0% animal fat) or normal diet. We examined histological changes, levels of hepatic lipids and hepatic bile acids, and expression of genes related to bile acid and cholesterol metabolism. HFD-fed Bsep+/- mice exhibited milder hepatic steatosis and less weight gain, compared to HFD-fed WT mice. The concentrations of total bile acid, triglycerides, and cholesterols were reduced in the liver of HFD-fed Bsep+/- mice. Regarding hepatic bile acid metabolism, the expression levels of Farnesoid X receptor (Fxr) and Multidrug resistance-associated protein 2 were significantly upregulated in HFD-fed Bsep+/- mice, compared to HFD-fed WT mice. Furthermore, several alterations were observed in upstream cholesterol metabolism in the liver. The expression levels of bile acid metabolism-related genes were also altered in the intestine of HFD-fed Bsep+/- mice. In conclusion, HFD-fed Bsep+/- mice exhibited significant alterations of the expression levels of genes related to bile acid and lipid metabolism in both the liver and ileum, resulting in alleviated steatosis and less weight gain. These results suggest the importance of BSEP for maintenance of bile acid and cholesterol metabolism. Further investigations of the involvement of BSEP in the pathogenesis of NASH will provide greater insight and facilitate the development of novel therapeutic modalities.


Assuntos
Membro 11 da Subfamília B de Transportadores de Cassetes de Ligação de ATP/deficiência , Dieta Hiperlipídica/efeitos adversos , Hepatopatia Gordurosa não Alcoólica/etiologia , Hepatopatia Gordurosa não Alcoólica/metabolismo , Membro 11 da Subfamília B de Transportadores de Cassetes de Ligação de ATP/genética , Animais , Ácidos e Sais Biliares/metabolismo , Colesterol/metabolismo , Modelos Animais de Doenças , Heterozigoto , Íleo/metabolismo , Metabolismo dos Lipídeos , Fígado/metabolismo , Fígado/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Hepatopatia Gordurosa não Alcoólica/patologia
10.
Life Sci ; 258: 118240, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32781072

RESUMO

As a dicarboxylic acid with the structural formula HOOCCH (OH) COOH, tartronic acid is considered as an inhibitor of the transformation of carbohydrates into fat under fat-deficient diet conditions. However, the effect of tartronic acid on lipogenesis under high-fat diet conditions has yet to be established. In this work, we investigated the regulatory role of tartronic acid in lipogenesis in 3T3-L1 adipocytes and C57BL/6J mice. The results confirmed that tartronic acid promoted weight gain (without affecting food intake) and induced adipocyte hypertrophy in epididymal white adipose tissue and lipid accumulation in the livers of high-fat diet-induced obese mice. In vitro, tartronic acid promoted 3T3-L1 adipocyte differentiation by increasing the protein expression of FABP-4, PPARγ and SREBP-1. Moreover, the contents of both acetyl-CoA and malonyl-CoA were significantly upregulated by treatment with tartronic acid, while the protein expression of CPT-1ß were inhibited. In summary, we proved that tartronic acid promotes lipogenesis by serving as substrates for fatty acid synthesis and inhibiting CPT-1ß, providing a new perspective for the study of tartronic acid.


Assuntos
Acetilcoenzima A/biossíntese , Carnitina O-Palmitoiltransferase/antagonistas & inibidores , Lipogênese/efeitos dos fármacos , Malonil Coenzima A/biossíntese , Tartronatos/farmacologia , Regulação para Cima/efeitos dos fármacos , Células 3T3-L1 , Animais , Carnitina O-Palmitoiltransferase/metabolismo , Dieta Hiperlipídica/efeitos adversos , Lipogênese/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Regulação para Cima/fisiologia
11.
Pediatr Endocrinol Rev ; 17(4): 308-316, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32780954

RESUMO

Childhood obesity is a considerable worldwide health problem and a major risk factor for several chronic diseases. Fat rich diets result in altered serum levels of lipids, cytokines and hormonal factors, which influence skeletal acquisition and promote microstructural and mechanical behavior changes in bone, especially to bone quality and quantity. However, the possible longterm implications of high-fat diets in childhood are controversial. Despite not fully understood, multiple signaling pathways which support bone tissue homeostasis are altered under hyperlipidic conditions, including RANKL/RANK/OPG, PPAR-γ/Alox5/5-LO, leptin/IGF-I/AGE, ApoE/Lrp-1, Thy-1, IL-6, TNFα, calcium, vitamin D and K metabolism. Moreover, the expression of reactive oxygen species is also modified. Considering the importance of this subject, the aim of this review was to explore the mechanisms of bone formation affected by obesity during childhood during childhood.


Assuntos
Osso e Ossos , Obesidade Pediátrica , Criança , Dieta Hiperlipídica , Humanos , Leptina , Osteogênese
12.
Nat Commun ; 11(1): 3794, 2020 07 30.
Artigo em Inglês | MEDLINE | ID: mdl-32732906

RESUMO

Defective rhythmic metabolism is associated with high-fat high-caloric diet (HFD) feeding, ageing and obesity; however, the neural basis underlying HFD effects on diurnal metabolism remains elusive. Here we show that deletion of BMAL1, a core clock gene, in paraventricular hypothalamic (PVH) neurons reduces diurnal rhythmicity in metabolism, causes obesity and diminishes PVH neuron activation in response to fast-refeeding. Animal models mimicking deficiency in PVH neuron responsiveness, achieved through clamping PVH neuron activity at high or low levels, both show obesity and reduced diurnal rhythmicity in metabolism. Interestingly, the PVH exhibits BMAL1-controlled rhythmic expression of GABA-A receptor γ2 subunit, and dampening rhythmicity of GABAergic input to the PVH reduces diurnal rhythmicity in metabolism and causes obesity. Finally, BMAL1 deletion blunts PVH neuron responses to external stressors, an effect mimicked by HFD feeding. Thus, BMAL1-driven PVH neuron responsiveness in dynamic activity changes involving rhythmic GABAergic neurotransmission mediates diurnal rhythmicity in metabolism and is implicated in diet-induced obesity.


Assuntos
Fatores de Transcrição ARNTL/genética , Ritmo Circadiano/fisiologia , Obesidade/patologia , Núcleo Hipotalâmico Paraventricular/metabolismo , Receptores de GABA-A/metabolismo , Animais , Ritmo Circadiano/genética , Dieta Hiperlipídica , Metabolismo Energético/fisiologia , Comportamento Alimentar/fisiologia , Camundongos , Camundongos Knockout , Neurônios/fisiologia , Obesidade/genética , Núcleo Hipotalâmico Paraventricular/citologia
13.
An Acad Bras Cienc ; 92(2): e20191230, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32785427

RESUMO

This work evaluated the effect of grape juice, red wine and resveratrol in liver parameters of rats submitted to high-fat diet. Experimental model was conducted with groups of adult females Rattus norvegicus: control (CG); high-fat (HG); grape juice (JG); red wine (RW) and resveratrol solution (RG). The high-fat diet significantly altered hepatocytes and Kupffer cells in all treated groups. HG group presented severe steatosis followed hepatocyte ballooning and tissue damages. JG group minimized hepatic histological lesion caused by high-fat diet and WG group also induced steatosis and inflammation in hepatocytes, similar to HG. Still, resveratrol protected the tissue against fatty liver disease by reducing fat infiltration and inflammation, indicating possible therapeutic effects on the liver. Cell cycle analysis showed that HG promoted damage to the tissue, reducing the viable cell content and increasing apoptosis, even when associated with wine consumption or isolated resveratrol. However, JG protected the liver against cell damage generated by the diet. Consumption of grape juice, even associated with a high-fat diet, represents a promising protection of the liver against cellular damage, but red wine further affects the tissue, and resveratrol alone was able to reduce damage but did not minimize cellular damage to the liver.


Assuntos
Vitis , Vinho , Animais , Dieta Hiperlipídica , Feminino , Sucos de Frutas e Vegetais , Fígado , Ratos , Ratos Wistar , Resveratrol , Estilbenos
14.
Proc Natl Acad Sci U S A ; 117(33): 20149-20158, 2020 08 18.
Artigo em Inglês | MEDLINE | ID: mdl-32747560

RESUMO

The C2 domain containing protein extended synaptotagmin (E-Syt) plays important roles in both lipid homeostasis and the intracellular signaling; however, its role in physiology remains largely unknown. Here, we show that hypothalamic E-Syt3 plays a critical role in diet-induced obesity (DIO). E-Syt3 is characteristically expressed in the hypothalamic nuclei. Whole-body or proopiomelanocortin (POMC) neuron-specific ablation of E-Syt3 ameliorated DIO and related comorbidities, including glucose intolerance and dyslipidemia. Conversely, overexpression of E-Syt3 in the arcuate nucleus moderately promoted food intake and impaired energy expenditure, leading to increased weight gain. Mechanistically, E-Syt3 ablation led to increased processing of POMC to α-melanocyte-stimulating hormone (α-MSH), increased activities of protein kinase C and activator protein-1, and enhanced expression of prohormone convertases. These findings reveal a previously unappreciated role for hypothalamic E-Syt3 in DIO and related metabolic disorders.


Assuntos
Regulação da Expressão Gênica/fisiologia , Obesidade/induzido quimicamente , Obesidade/genética , Sinaptotagminas/metabolismo , Animais , Dieta Hiperlipídica/efeitos adversos , Predisposição Genética para Doença , Hipotálamo/metabolismo , Masculino , Camundongos , Camundongos Knockout , Neurônios/metabolismo , Pró-Proteína Convertase 1/genética , Pró-Proteína Convertase 1/metabolismo , Pró-Proteína Convertase 2/genética , Pró-Proteína Convertase 2/metabolismo , Sinaptotagminas/genética
15.
Life Sci ; 258: 118030, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32739470

RESUMO

The risk of atherosclerosis (AS) ascends among post-menopausal women, while current hormone replacement therapy exerts several adverse effects. Alisol B 23-acetate (AB23A), a tetracyclic triterpenoid isolated from the rhizome of Alisma orientale, was reported to show multiple physiological activities, including regulating lipid metabolism. According to molecular docking analysis, it was predicted to bind with estrogen receptor α (ERα). In this study, we aimed to observe the effect of AB23A on preventing post-menopausal AS and explore whether the mechanism was mediated by ERα. In vitro, free fatty acid (FFA) was applied to induce the abnormal lipid metabolism of L02 cells. In vivo, the ApoE-/- mice were ovariectomized to mimic the cessation of estrogen. The high-fat diet was also given to induce post-menopausal AS. We demonstrated AB23A attenuated the accumulation of total cholesterol and triglyceride induced by free fatty acids in hepatocytes. In high-fat diet-ovariectomy-treated ApoE-/- mice, AB23A eliminated lipids in blood and liver. AB23A not only reduced the synthesis of proprotein convertase subtilisin/kexin type 9 (PCSK9) through sterol-regulatory element binding proteins (SREBPs) but also suppressed the secretion of PCSK9 through silent information regulator 1 (SIRT1). Notably, AB23A promoted the expression of ERα in vivo and in vitro. The both ERα inhibitor and ERα siRNA were also applied in confirming whether the hepatic protective effect of AB23A was mediated by ERα. We found that AB23A significantly promoted the expression of ERα. AB23A could inhibit the synthesis and secretion of PCSK9 through ERα, lower the accumulation of triglyceride and cholesterol, and prevent post-menopausal AS.


Assuntos
Aterosclerose/patologia , Colestenonas/farmacologia , Receptor alfa de Estrogênio/metabolismo , Metabolismo dos Lipídeos/efeitos dos fármacos , Pós-Menopausa/efeitos dos fármacos , Animais , Aterosclerose/genética , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Colestenonas/química , Dieta Hiperlipídica , Ácidos Graxos/metabolismo , Feminino , Lipoproteínas LDL/metabolismo , Camundongos , Ovariectomia , Regiões Promotoras Genéticas/genética , Pró-Proteína Convertase 9/genética , Pró-Proteína Convertase 9/metabolismo , Receptores de LDL/genética , Receptores de LDL/metabolismo , Sirtuína 1/metabolismo , Proteínas de Ligação a Elemento Regulador de Esterol/genética , Proteínas de Ligação a Elemento Regulador de Esterol/metabolismo , Regulação para Cima/efeitos dos fármacos
16.
Life Sci ; 258: 118204, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32763296

RESUMO

AIMS: Liver kinase B1 (LKB1) is a serine/threonine kinase. Although many biological functions of LKB1 have been identified, the role of hypothalamic LKB1 in the regulation of central energy metabolism and susceptibility to obesity is unknown. Therefore, we constructed POMC neuron-specific LKB1 knockout mice (PomcLkb1 KO) and studied it at the physiological, morphological, and molecular biology levels. MAIN METHODS: Eight-week-old male PomcLkb1 KO mice and their littermates were fed a standard chow fat diet (CFD) or a high-fat diet (HFD) for 3 months. Body weight and food intake were monitored. Dual-energy X-ray absorptiometry was used to measure the fat mass and lean mass. Glucose and insulin tolerance tests and serum biochemical markers were evaluated in the experimental mice. In addition, the levels of peripheral lipogenesis genes and central energy metabolism were measured. KEY FINDINGS: PomcLkb1 KO mice did not exhibit impairments under normal physiological conditions. After HFD intervention, the metabolic phenotype of the PomcLkb1 KO mice changed, manifesting as increased food intake and an enhanced obesity phenotype. More seriously, PomcLkb1 KO mice showed increased leptin resistance, worsened hypothalamic inflammation and reduced POMC neuronal expression. SIGNIFICANCE: We provide evidence that LKB1 in POMC neurons plays a significant role in regulating energy homeostasis. LKB1 in POMC neurons emerges as a target for therapeutic intervention against HFD-induced obesity and metabolic diseases.


Assuntos
Deleção de Genes , Neurônios/enzimologia , Obesidade/enzimologia , Pró-Opiomelanocortina/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Tecido Adiposo/patologia , Animais , Dieta Hiperlipídica , Epididimo/patologia , Comportamento Alimentar , Regulação da Expressão Gênica , Glucose/metabolismo , Hipotálamo/patologia , Inflamação/patologia , Leptina/metabolismo , Fígado/enzimologia , Fígado/patologia , Masculino , Camundongos Endogâmicos C57BL , Camundongos Knockout , NF-kappa B/metabolismo , Obesidade/sangue , Obesidade/patologia , Pró-Opiomelanocortina/genética , Ganho de Peso
17.
Nat Commun ; 11(1): 4313, 2020 08 27.
Artigo em Inglês | MEDLINE | ID: mdl-32855402

RESUMO

It has been suggested that beige fat thermogenesis is tightly controlled by epigenetic regulators that sense environmental cues such as temperature. Here, we report that subcutaneous adipose expression of the DNA demethylase TET1 is suppressed by cold and other stimulators of beige adipocyte thermogenesis. TET1 acts as an autonomous repressor of key thermogenic genes, including Ucp1 and Ppargc1a, in beige adipocytes. Adipose-selective Tet1 knockout mice generated by using Fabp4-Cre improves cold tolerance and increases energy expenditure and protects against diet-induced obesity and insulin resistance. Moreover, the suppressive role of TET1 in the thermogenic gene regulation of beige adipocytes is largely DNA demethylase-independent. Rather, TET1 coordinates with HDAC1 to mediate the epigenetic changes to suppress thermogenic gene transcription. Taken together, TET1 is a potent beige-selective epigenetic breaker of the thermogenic gene program. Our findings may lead to a therapeutic strategy to increase energy expenditure in obesity and related metabolic disorders.


Assuntos
Adipócitos Bege/metabolismo , Proteínas de Ligação a DNA/metabolismo , Epigênese Genética , Obesidade/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Termogênese/genética , Animais , Calorimetria Indireta , Linhagem Celular , Temperatura Baixa/efeitos adversos , Proteínas de Ligação a DNA/genética , Dieta Hiperlipídica/efeitos adversos , Modelos Animais de Doenças , Metabolismo Energético/genética , Regulação da Expressão Gênica/fisiologia , Células HEK293 , Humanos , Resistência à Insulina/genética , Masculino , Camundongos , Camundongos Knockout , Obesidade/etiologia , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/metabolismo , Proteínas Proto-Oncogênicas/genética , RNA-Seq , Gordura Subcutânea/citologia , Gordura Subcutânea/metabolismo , Proteína Desacopladora 1/metabolismo
18.
Chem Biol Interact ; 330: 109199, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32805210

RESUMO

Obesity is characterized by the deposition of excessive body fat, and is caused by energy imbalance, especially when consuming fat-rich diets. High fat diet (HFD)-associated obesity is greatly common in patients with non-alcoholic fatty liver disease (NAFLD) that is emerging as one of the most universal causes of liver disease worldwide, especially in Western countries. In spite of its high prevalence, only a small proportion of affected individuals will become inflamed, followed by fibrosis and chronic liver diseases, and most patients only show simple steatosis. In this case, the full comprehension of the mechanisms underlying the progression of NAFLD is of extreme significance; in spite of progress in this field, awareness on the development of NAFLD is still incomplete. Traditionally, liver steatosis is commonly connected with HFD, obesity, and insulin resistance (IR). Recently, various possible mechanisms have been put forward for liver damage, including endoplasmic reticulum stress, perturbation of autophagy, mitochondrial dysfunction, hepatocellular apoptosis, gut microbiota imbalance, dysregulation of microRNAs, and genetic/epigenetic risk factors, as well as an increase in inflammatory responses, among many others. Collectively, these proposed mechanisms allow for a variety of hits acting together on subjects to mediated NAFLD and will offer a more accurate explanation for progression of NAFLD. Therefore, this review summarizes the present information concerning NAFLD after HFD exposure, as well as discusses possible mechanisms through which it may arise.


Assuntos
Dieta Hiperlipídica/efeitos adversos , Hepatopatia Gordurosa não Alcoólica/induzido quimicamente , Animais , Microbioma Gastrointestinal/efeitos dos fármacos , Humanos , Fígado/efeitos dos fármacos , Fígado/metabolismo , Hepatopatia Gordurosa não Alcoólica/complicações , Hepatopatia Gordurosa não Alcoólica/metabolismo , Hepatopatia Gordurosa não Alcoólica/patologia , Obesidade/complicações
19.
Am J Physiol Regul Integr Comp Physiol ; 319(3): R347-R357, 2020 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-32755463

RESUMO

How low-level psychological stress and overnutrition interact in influencing cardiometabolic disease is unclear. Mechanistic overlaps suggest potential synergies; however, findings are contradictory. We test whether low-level stress and Western diet (WD) feeding synergistically influence homeostasis, mood, and myocardial ischemic tolerance. Male C57BL6/J mice were fed a control diet or WD (32%/57%/11% calories from fat/carbohydrates/protein) for 12 wk, with subgroups restrained for 30 min/day over the final 3 wk. Metabolism, behavior, tolerance of perfused hearts to ischemia-reperfusion (I/R), and cardiac "death proteins" were assessed. The WD resulted in insignificant trends toward increased body weight (+5%), glucose (+40%), insulin (+40%), triglycerides (+15%), and cholesterol (+20%) and reduced leptin (-20%) while significantly reducing insulin sensitivity [100% rise in homeostasis model assessment of insulin resistance (HOMA-IR), P < 0.05]. Restraint did not independently influence metabolism while increasing HOMA-IR a further 50% (and resulting in significant elevations in insulin and glucose to 60-90% above control) in WD mice (P < 0.05), despite blunting weight gain in control and WD mice. Anxiogenesis with restraint or WD was nonadditive, whereas anhedonia (reduced sucrose consumption) only arose with their combination. Neuroinflammation markers (hippocampal TNF-α, Il-1b) were unchanged. Myocardial I/R tolerance was unaltered with stress or WD alone, whereas the combination worsened dysfunction and oncosis [lactate dehydrogenase (LDH) efflux]. Apoptosis (nucleosome accumulation) and death protein expression (BAK, BAX, BCL-2, RIP-1, TNF-α, cleaved caspase-3, and PARP) were unchanged. We conclude that mild, anxiogenic yet cardio-metabolically "benign" stress interacts synergistically with a WD to disrupt homeostasis, promote anhedonia (independently of neuroinflammation), and impair myocardial ischemic tolerance (independently of apoptosis and death protein levels).


Assuntos
Dieta Hiperlipídica , Ingestão de Energia/fisiologia , Homeostase/fisiologia , Isquemia Miocárdica/fisiopatologia , Miocárdio/metabolismo , Animais , Coração/fisiopatologia , Resistência à Insulina/fisiologia , Camundongos Endogâmicos C57BL , Isquemia Miocárdica/metabolismo , Obesidade/fisiopatologia
20.
PLoS One ; 15(8): e0237708, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32817646

RESUMO

Parental high-fat diet (HFD) programs for obesity and hypertension in female offspring in rats, but it is unknown how the pregnancies of these offspring are impacted. Therefore, the hypothesis was tested that parental HFD exaggerates obesity and hypertension during pregnancy of the offspring. Wistar Hannover rat dams (the parental, P generation) were maintained on normal-fat diet (NFD) or HFD from weaning and were kept on respective diets through pregnancy and lactation. Their offspring (the first filial, F1 generation) were weaned onto the same diet as the P generation, or they were changed to the other diet to determine if combined HFD in the P and F1 generations exaggerates body weight and blood pressure levels during pregnancy in these offspring. This diet paradigm resulted in the following groups of pregnant F1 offspring: P-NFD/F1-NFD, P-HFD/F1-NFD, P-NFD/F1-HFD, and P-HFD/F1-HFD. Maternal body and adipose tissue weights were greatest in the P-HFD/F1-HFD group compared to the other 3 groups by the end of pregnancy. Plasma leptin and conscious mean arterial blood pressure were not significantly different between any group, although there was a main effect for increased blood pressure in the F1-HFD groups. Circulating levels of the antihypertensive pregnancy factor, placental growth factor (PlGF), were assessed. Although average PlGF levels were similar among all groups, correlative studies revealed that lower levels of PlGF were associated with higher blood pressure only in the P-HFD/F1-HFD group. In summary, HFD feeding from the P generation exaggerated HFD-induced body and adipose tissue weights in the pregnant offspring.


Assuntos
Hipertensão/sangue , Leptina/sangue , Obesidade/sangue , Fator de Crescimento Placentário/sangue , Efeitos Tardios da Exposição Pré-Natal/sangue , Adiposidade/genética , Animais , Pressão Sanguínea/genética , Peso Corporal/genética , Dieta Hiperlipídica , Modelos Animais de Doenças , Feminino , Humanos , Hipertensão/genética , Hipertensão/fisiopatologia , Masculino , Herança Materna/genética , Obesidade/genética , Obesidade/fisiopatologia , Gravidez , Efeitos Tardios da Exposição Pré-Natal/fisiopatologia , Ratos , Desmame
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