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1.
Cancer Sci ; 115(4): 1154-1169, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38278779

RESUMO

Advanced colorectal cancer (CRC) is characterized by a high recurrence and metastasis rate, which is the primary cause of patient mortality. Unfortunately, effective anti-cancer drugs for CRC are still lacking in clinical practice. We screened FDA-approved drugs by utilizing targeted organoid sequencing data and found that the antifungal drug itraconazole had a potential therapeutic effect on CRC tumors. However, the effect and mechanism of itraconazole on CRC tumors have not been investigated. A cell line-derived xenograft model in tumor-bearing mice was established and single-cell RNA sequencing was performed on tumor samples from four mice with or without itraconazole treatment. The proportion of cell populations and gene expression profiles was significantly different between the two groups. We found that itraconazole could inhibit tumor growth and glycolysis. We revealed that CEBPB was a new target for itraconazole, and that silencing CEBPB could repress CRC glycolysis and tumor growth by inhibiting ENO1 expression. Clinical analysis showed that CEBPB expression was obviously elevated in CRC patients, and was associated with poor survival. In summary, itraconazole treatment remodeled cell composition and gene expression profiles. Itraconazole inhibited cell glycolysis and tumor growth via the CEBPB-ENO1 axis. In this study, we illustrate a new energy metabolism mechanism for itraconazole on tumor growth in CRC that will provide a theoretical basis for CRC targeting/combination therapy.


Assuntos
Neoplasias Colorretais , Itraconazol , Humanos , Animais , Camundongos , Itraconazol/farmacologia , Itraconazol/uso terapêutico , Linhagem Celular Tumoral , Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/genética , Neoplasias Colorretais/patologia , Modelos Animais de Doenças , Glicólise , Proliferação de Células , Regulação Neoplásica da Expressão Gênica , Proteína beta Intensificadora de Ligação a CCAAT/genética
2.
Arch Toxicol ; 2024 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-38987487

RESUMO

Ferroptosis is a form of cell death that is induced by iron-mediated accumulation of lipid peroxidation. The involvement of ferroptosis in different pathophysiological conditions has offered new perspectives on potential therapeutic interventions. Natural products, which are widely recognized for their significance in drug discovery and repurposing, have shown great promise in regulating ferroptosis by targeting various ferroptosis players. In this review, we discuss the regulatory mechanisms of ferroptosis and its implications in different pathological conditions. We dissect the interactions between natural products and ferroptosis in cancer, ischemia/reperfusion, neurodegenerative diseases, acute kidney injury, liver injury, and cardiomyopathy, with an emphasis on the relevance of ferroptosis players to disease targetability.

3.
Angew Chem Int Ed Engl ; 62(26): e202305260, 2023 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-37118979

RESUMO

Only rarely have polyoxometalates been found to form core-shell nanoclusters. Here, we succeeded in isolating a series of rare giant and all-inorganic core-shell cobalt polyoxoniobates (Co-PONbs) with diverse shapes, nuclearities and original topologies, including 50-nuclearity {Co12 Nb38 O132 }, 54-nuclearity {Co20 Nb34 O128 }, 62-nuclearity {Co26 Nb36 O140 } and 87-nuclearity {Co33 Nb54 O188 }. They are the largest Co-PONbs and also the polyoxometalates containing the greatest number of Co ions and the largest cobalt clusters known thus far. These molecular Co-PONbs have intriguing and atomically precise core-shell architectures comprising unique cobalt oxide cores and niobate oxide shells. In particular, the encapsulated cobalt oxide cores with different nuclearities have identical compositions, structures and mixed-valence Co3+ /Co2+ states as the different sized Co-O moieties of the bulk cubic-spinel Co3 O4 , suggesting that they can serve as various molecular models of the cubic-spinel Co3 O4 . The successful construction of the series of the Co-PONbs reveals a feasible and versatile synthetic method for making rare core-shell heterometallic PONbs. Further, these new-type core-shell bimetal species are promising cluster molecular catalysts for visible-light-driven CO2 reduction.


Assuntos
Dióxido de Carbono , Óxidos , Óxidos/química , Cobalto/química
4.
Hum Mol Genet ; 29(3): 444-458, 2020 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-31915829

RESUMO

Inherited optic neuropathies are rare eye diseases of optic nerve dysfunction that present in various genetic forms. Previously, mutation in three genes encoding mitochondrial proteins has been implicated in autosomal recessive forms of optic atrophy that involve progressive degeneration of optic nerve and retinal ganglion cells (RGC). Using whole exome analysis, a novel double homozygous mutation p.L81R and pR212W in malonyl CoA-acyl carrier protein transacylase (MCAT), a mitochondrial protein involved in fatty acid biosynthesis, has now been identified as responsible for an autosomal recessive optic neuropathy from a Chinese consanguineous family. MCAT is expressed in RGC that are rich in mitochondria. The disease variants lead to structurally unstable MCAT protein with significantly reduced intracellular expression. RGC-specific knockdown of Mcat in mice, lead to an attenuated retinal neurofiber layer, that resembles the phenotype of optic neuropathy. These results indicated that MCAT plays an essential role in mitochondrial function and maintenance of RGC axons, while novel MCAT p.L81R and p.R212W mutations can lead to optic neuropathy.


Assuntos
Proteína de Transporte de Acila S-Maloniltransferase/genética , Genes Recessivos , Mitocôndrias/patologia , Doenças do Nervo Óptico/patologia , Nervo Óptico/patologia , Células Ganglionares da Retina/patologia , Proteína de Transporte de Acila S-Maloniltransferase/química , Proteína de Transporte de Acila S-Maloniltransferase/metabolismo , Sequência de Aminoácidos , Animais , Criança , Feminino , Humanos , Masculino , Camundongos , Camundongos Knockout , Mitocôndrias/metabolismo , Mutação , Nervo Óptico/metabolismo , Doenças do Nervo Óptico/etiologia , Doenças do Nervo Óptico/metabolismo , Linhagem , Conformação Proteica , Células Ganglionares da Retina/metabolismo , Homologia de Sequência , Sequenciamento do Exoma
5.
Mikrochim Acta ; 188(4): 111, 2021 03 05.
Artigo em Inglês | MEDLINE | ID: mdl-33666754

RESUMO

For the first time CoS-nanoparticles attached ZnS rods (CoS/ZnS composites) have been synthesized using cobalt(II)-ion-exchanged zinc-based biological metal-organic framework-1 (Zn-bio-MOF-1) as precursors by a solvothermal method. Among them, the cobalt(II)-ion-exchanged Zn-bio-MOF-1 was obtained by exchanging the dimethylammonium cations (Me2NH2+) of Zn-bio-MOF-1 with cobalt ions. A novel electrochemical sensor based on CoS/ZnS composites and molecularly imprinted polymers (MIPs) was proposed for rapid, sensitive, and highly selective detection of organochlorine pesticide chloroneb. The MIP film was obtained by cyclic voltammetry (CV), and differential pulse voltammetry (DPV) was used to detect chloroneb. Under the optimal conditions, the oxidation peak current density of chloroneb was linearly related to the concentration from 0.003 to 0.2 µM and 0.2 to 3.2 µM with a detection limit of 0.87 nM (S/N = 3) and a sensitivity of 52.27 µA·µM-1·cm-2. The proposed sensor exhibits a favorable selectivity, stability, and reproducibility, and was applied to detect chloroneb residues in licorice, cucumber, river water, and soil samples with satisfactory results.Graphical abstract.

6.
Mikrochim Acta ; 188(6): 204, 2021 05 27.
Artigo em Inglês | MEDLINE | ID: mdl-34043073

RESUMO

A molecularly imprinted ratiometric fluorescent sensor was synthesized for the detection of 4-bromophenoxybenzene (BDE-3) based on perovskite quantum dots and metal organic framework. First, aspartic acid (Asp) was introduced during the synthesis of perovskite CsPbX3 for the formation of a core-shell structure of CsPbX3@Asp-Cs4PbX6. Due to the protection of the shell layer Cs4PbX6, the stability of the core CsPbX3 was improved significantly. Compared to CsPb(BrI)3, the ultraviolet and thermal stabilities of CsPb(BrI)3@Asp-Cs4Pb(BrI)6 were increased by 26 times and 32 times, respectively, and, compared to CsPbBr3, these stabilities of CsPbBr3@Asp-Cs4PbBr6 were increased by 3 times and 13 times, respectively. The water stabilities of CsPb(BrI)3@Asp-Cs4Pb(BrI)6 and CsPbBr3@Asp-Cs4PbBr6 were greatly improved too. Then, a ratiometric fluorescence sensor was constructed by in situ growth of CsPb(BrI)3@Asp-Cs4Pb(BrI)6 in metal organic framework (NH2-MIL-53) for the detection of BDE-3, in which the orange fluorescence of CsPb(BrI)3@Asp-Cs4Pb(BrI)6 (614 nm) was regarded as the reference signal and the cyan fluorescence of NH2-MIL-53 (494 nm) was used as the fluorescence response signal. To improve the selectivity of the sensor, the molecular imprinting polymer (MIP) was modified on the NH2-MIL-53 and an imprinting factor of 3.17 was obtained. Under 365 nm light excitation, the fluorescent response signal at 494 nm was quenched gradually by BDE-3 in the range 11.4 to 68.5 nmol/L, while the reference signal at 614 nm remained unchanged. The limit of detection and limit of quantification were 3.35 and 11.2 nmol/L, respectively, and the fluorescent color of the sensor changed gradually from cyan to green to orange, which illustrated that the developed sensor has an ability to recognize BDE-3 specifically, a good anti-interference ability, and a sensitively visual detection ability. Moreover, the sensor was successfully applied to the BDE-3 detection in polyethylene terephthalate plastic bottle, polyvinyl chloride plastic bag, and circuit board with satisfactory recoveries (96.3-108.1%) and low relative standard deviations (5%). The preparation processes of NH2-MIL-53, NH2-MIL-53-CsPb(BrI)3@Asp-Cs4Pb(BrI)6, and the MIP-NH2-MIL-53-CsPb(BrI)3@Asp-Cs4Pb(BrI)6 composites.

7.
Biochem Biophys Res Commun ; 527(3): 611-617, 2020 06 30.
Artigo em Inglês | MEDLINE | ID: mdl-32423794

RESUMO

Induction of apoptosis is a strategy in the treatment of glioma, a malignant tumor with the highest prevalence in the brain. Sodium butyrate (NaB) induces apoptosis in glioma cells at pharmacological dosages (>2.5 mM), but the mechanism remains largely unknown beyond the mitochondrial potential drop. In this study, NaB was found to open the mitochondrial permeability transient pore (MPTP) to induce a proton leak in the mechanism of apoptosis. The MPTP opening led to collapse of mitochondrial potential and suppression of ATP production in the NaB-treated cells. Proton leak was increased in the mitochondria under the coupling and uncoupling conditions from the MPTP opening. The proton leak was associated with an elevation in the protein abundance of adenine nucleotide translocator 2 (ANT2) and was blocked by an ANT-specific inhibitor of bongkrekic acid (BA). These data suggest that the proton leak is induced by NaB for the mitochondrial potential drop in the induction of apoptosis. The mechanism may be related to activation of ANT2 in the MPTP complex.


Assuntos
Apoptose/efeitos dos fármacos , Ácido Butírico/farmacologia , Poro de Transição de Permeabilidade Mitocondrial/metabolismo , Linhagem Celular Tumoral , Glioma/tratamento farmacológico , Glioma/metabolismo , Humanos , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Prótons
8.
Biochem Biophys Res Commun ; 526(2): 519-524, 2020 05 28.
Artigo em Inglês | MEDLINE | ID: mdl-32245617

RESUMO

The intestinal barrier dysfunction is closely implicated in low-grade chronic inflammation for insulin resistance in diet-induced obesity (DIO). It is generally believed that degradation of colon enterocytes contributes to intestinal barrier dysfunction in the pathological process of obesity. Sennoside A (SA) is reported to improve metabolic disorders, but the effect and mechanism of SA on colonic barrier function of DIO remains unknown. In this study, SA was found to restore colonic barrier function by protecting the continuity and integrity of colon enterocytes in DIO mice. An increase in mRNA expression of tight junction proteins Occludin, Claudin-2 and ZO-1 provides another mechanism of restoring colonic barrier function in SA-treated group. In the research of mechanism, mitophagy was inhibited by SA via a protection of mitochondrial structure and function in colon. A reduction was found in production of reactive oxygen species (ROS) in the colon, and the benefical effect was attributed to an inhibition of activity in complex I and III with a reduction of protein expression and an increase of Mn-SOD activity. The results indicate that SA can restores colonic barrier function through protecting colon enterocytes from ROS-induced mitochondrial damage in DIO mice.


Assuntos
Colo , Enterócitos , Animais , Colo/patologia , Dieta , Enterócitos/metabolismo , Mucosa Intestinal/metabolismo , Camundongos , Camundongos Obesos , Obesidade/tratamento farmacológico , Obesidade/etiologia , Obesidade/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Senosídeos , Junções Íntimas/metabolismo
9.
Biochem Biophys Res Commun ; 525(3): 733-739, 2020 05 07.
Artigo em Inglês | MEDLINE | ID: mdl-32143825

RESUMO

Cigarette smoke is one of major risk factors in the pathogenesis of chronic obstructive pulmonary disease (COPD). It is generally believed that cigarette smoke induces mitochondrial damage in the alveolar epithelial cells to contribute to COPD. However, the exact molecular mechanism remains unknown for the mitochondrial damage. In this study, cigarette smoke extract (CSE) was found to induce the mitochondrial membrane permeability (MMP), which promoted proton leakage leading to the reduction in mitochondrial potential and ATP production. ANT in the mitochondrial inner membrane was activated by CSE for the alteration of MMP. The activation was observed without an alteration in the protein level of ANT. Inhibition of the ANT activity with ADP or bongkrekic acid prevented the MMP alteration and potential drop upon CSE exposure. The ANT activation was observed with a rise in ROS production, inhibition of the mitochondrial respiration, decrease in the complex III protein and rise in mitophagy activity. The results suggest that ANT may mediate the toxic effect of cigarette smoke on mitochondria and control of ANT activity is a potential strategy in intervention of the toxicity.


Assuntos
Translocador 1 do Nucleotídeo Adenina/metabolismo , Fumar Cigarros/efeitos adversos , Células Epiteliais/metabolismo , Pulmão/patologia , Membranas Mitocondriais/metabolismo , Células A549 , Trifosfato de Adenosina/metabolismo , Animais , Respiração Celular , Complexo III da Cadeia de Transporte de Elétrons/metabolismo , Humanos , Masculino , Potencial da Membrana Mitocondrial , Camundongos Endogâmicos C57BL , Mitocôndrias/metabolismo , Mitofagia , Modelos Biológicos , Permeabilidade , Doença Pulmonar Obstrutiva Crônica/patologia
10.
Mikrochim Acta ; 187(11): 623, 2020 10 22.
Artigo em Inglês | MEDLINE | ID: mdl-33090285

RESUMO

A molecularly imprinted ratiometric fluorescent probe (MIRF probe) was synthesized for the determination of aristolochic acid I (AAI) based on the Schiff-base fluorescent compound N,N'-bis(o-carboxybenzylidene)-p-4,4'-diaminobiphenyl (BDDB). The BDDB was immobilized in the silica nanoparticle (BDDB@SiO2) as an internal standard material. The blue-emitting BDDB@SiO2 and the yellow-emitting carbon quantum dots (y-CDs) were wrapped in the molecularly imprinted polymer (MIP) to provide a reliable reference signal at 440 nm and a fluorescent response signal at 530 nm at the excitation wavelength of 365 nm, respectively. In the preparation of the MIP of the MIRF probe, 4-vinylbenzoic acid as the functional monomer and AAI as the template molecule were used. An imprinting factor of 2.25 was obtained. Under the optimum conditions, the fluorescent response signal at 530 nm was quenched gradually by AAI in the range 1.0 to 120.0 µmol/L, while the reference signal at 440 nm remained unchanged. The limit of detection was 0.45 µmol/L, and the fluorescent color of the MIRF probe changed gradually from yellow to green to blue, which illustrated that the developed probe had a specific AAI recognition ability, a good anti-interference ability, and a sensitively visual determination ability. The probe was successfully applied to the AAI determination in traditional Chinese medicine (TCM) Asarum. The results showed that it had satisfactory recoveries (95.5-107.3%) and low relative standard deviations (2.0%). Furthermore, this method has a potential for the onsite naked eye determination of AAI in TCM samples.Graphical abstract.


Assuntos
Ácidos Aristolóquicos/química , Corantes Fluorescentes/química , Impressão Molecular/métodos , Reprodutibilidade dos Testes , Espectrometria de Fluorescência
11.
Sheng Li Xue Bao ; 72(4): 532-538, 2020 Aug 25.
Artigo em Zh | MEDLINE | ID: mdl-32820316

RESUMO

ATP is an important energy source for cells. Traditionally, intracellular ATP levels are believed to be relatively stable and will not rise consistently in the physiological conditions. However, new studies suggest that ATP levels may rise in multiple tissues under the condition of energy surplus contributing to the metabolic disorders in obesity. However, the molecular mechanism of ATP elevation remains unknown in obesity except the increase in energy supply. Based on our experimental results and the findings reported in the literature, we discuss the cellular and molecular mechanisms by which ATP levels are regulated in cells by multiple factors, including superoxide ions, mitochondrial flash, antioxidants, anti-apoptotic molecule Bcl-xL, AMP-activated protein kinase (AMPK) and metformin. Contribution of these factors to the alteration of ATP set-point will be discussed together with their impact on insulin resistance in type 2 diabetes mellitus. With a focus on the energy surplus in obesity, we explore the mechanism of insulin resistance induced by ATP elevation and provide an answer to the contradiction between the new experimental results and the traditional viewpoint of intracellular ATP. We propose that elevation of intracellular ATP may lead to metabolic disorder in obesity through activation of a feedback mechanism that inhibits mitochondrial function.


Assuntos
Diabetes Mellitus Tipo 2 , Metformina , Proteínas Quinases Ativadas por AMP , Trifosfato de Adenosina , Metabolismo Energético , Humanos , Obesidade
12.
Biochem Biophys Res Commun ; 512(1): 106-111, 2019 04 23.
Artigo em Inglês | MEDLINE | ID: mdl-30871779

RESUMO

LA (alpha-Lipoic acid) deficiency represents a risk factor in the pathogenesis of diabetic complications as synthetic LA is routinely used in the treatment of the complications in patients. The mechanism underlying LA deficiency remains elusive in the diabetic conditions. In the present study, we investigated the synthetic pathway of LA in both type 1 and 2 diabetic mice. LA deficiency was observed with a reduction in lipoylation of pyruvate dehydrogenase in the kidney of streptozocin-induced diabetic mice. Proteins of three enzymes (MCAT, OXSM and LIAS) in the LA synthetic pathway were examined in the kidney. A reduction was observed in OXSM, but not in the other two. In a 24h study in the cell culture, mRNA and protein of OXSM were transiently reduced by a high concentration of glucose (35 mM), and persistently decreased by TNF-α (20 nM). The high glucose effect was observed with the OXSM reduction in the kidney of db/db mice (type 2 diabetes model). The TNF-α effect was observed with OXSM reduction in the fat tissue of diet-induced obese mice. The result suggest that inhibition of OXSM by hyperglycemia and inflammation may contribute to the LA deficiency in the diabetic complications. The OXSM reduction suggests a new mechanism for the mitochondrial dysfunction in the pathogenesis of diabetic complications.


Assuntos
3-Oxoacil-(Proteína de Transporte de Acila) Sintase/metabolismo , Diabetes Mellitus Experimental/metabolismo , Ácido Tióctico/deficiência , 3-Oxoacil-(Proteína de Transporte de Acila) Sintase/genética , Células 3T3-L1 , Animais , Vias Biossintéticas , Diabetes Mellitus Experimental/genética , Glucose/metabolismo , Hiperglicemia/genética , Hiperglicemia/metabolismo , Rim/metabolismo , Lipoilação , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Mitocôndrias/metabolismo , Complexo Piruvato Desidrogenase/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ácido Tióctico/biossíntese , Fator de Necrose Tumoral alfa/metabolismo
13.
J Biol Chem ; 289(22): 15244-58, 2014 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-24759106

RESUMO

The small GTPase protein RAC1 participates in innate immunity by activating a complex program that includes cytoskeleton remodeling, chemotaxis, activation of NADPH oxidase, and modulation of gene expression. However, its role in regulating the transcriptional signatures that in term control the cellular inflammatory profiles are not well defined. Here we investigated the functional and mechanistic connection between RAC1 and the transcription factor NRF2 (nuclear factor erythroid 2-related factor 2), master regulator of the anti-oxidant response. Lipopolysaccharide and constitutively active RAC1(Q61L) mutant induced the anti-oxidant enzyme heme-oxygenase-1 (HO-1) through activation of NRF2. The use of KEAP1-insensitive NRF2 mutants indicated that RAC1 regulation of NRF2 is KEAP1-independent. Interestingly, NRF2 overexpression inhibited, whereas a dominant-negative mutant of NRF2 exacerbated RAC1-dependent activation of nuclear factor-κB (NF-κB), suggesting that NRF2 has an antagonistic effect on the NF-κB pathway. Moreover, we found that RAC1 acts through NF-κB to induce NRF2 because either expression of a dominant negative mutant of IκBα that leads to NF-κB degradation or the use of p65-NF-κB-deficient cells demonstrated lower NRF2 protein levels and basally impaired NRF2 signature compared with control cells. In contrast, NRF2-deficient cells showed increased p65-NF-κB protein levels, although the mRNA levels remain unchanged, indicating post-translational alterations. Our results demonstrate a new mechanism of modulation of RAC1 inflammatory pathway through a cross-talk between NF-κB and NRF2.


Assuntos
Inflamação/metabolismo , Microglia/imunologia , Fator 2 Relacionado a NF-E2/metabolismo , NF-kappa B/metabolismo , Proteínas rac1 de Ligação ao GTP/imunologia , Guanosina Trifosfato/metabolismo , Células HEK293 , Heme Oxigenase-1/genética , Heme Oxigenase-1/imunologia , Heme Oxigenase-1/metabolismo , Humanos , Inflamação/genética , Lipopolissacarídeos/farmacologia , Microglia/efeitos dos fármacos , Microglia/metabolismo , Fator 2 Relacionado a NF-E2/genética , Fator 2 Relacionado a NF-E2/imunologia , NF-kappa B/genética , NF-kappa B/imunologia , Estresse Oxidativo/imunologia , Espécies Reativas de Oxigênio/metabolismo , Proteínas rac1 de Ligação ao GTP/genética , Proteínas rac1 de Ligação ao GTP/metabolismo , Proteínas rho de Ligação ao GTP/genética , Proteínas rho de Ligação ao GTP/imunologia , Proteínas rho de Ligação ao GTP/metabolismo
14.
Am J Physiol Endocrinol Metab ; 308(6): E496-505, 2015 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-25564477

RESUMO

NF-κB induces transcriptional expression of proinflammatory genes and antiapoptotic genes. The two activities of NF-κB remain to be characterized in the mechanism of chronic inflammation in obesity. To address this issue, we inactivated NF-κB in adipose tissue by knocking out p65 (RelA) in mice (F-p65-KO) and examined the inflammation in lean and obese conditions. In the lean condition, KO mice exhibited a reduced inflammation in adipose tissue with a decrease in macrophage infiltration, M1 polarization, and proinflammatory cytokine expression. In the obese condition, KO mice had elevated inflammation with more macrophage infiltration, M1 polarization, and cytokine expression. In the mechanism of enhanced inflammation, adipocytes and macrophages exhibited an increase in cellular apoptosis, which was observed with more formation of crown-like structures (CLS) in fat tissue of KO mice. Body weight, glucose metabolism, and insulin sensitivity were not significantly altered in KO mice under the lean and obese conditions. A modest but significant reduction in body fat mass was observed in KO mice on HFD with an elevation in energy expenditure. The data suggest that in the control of adipose inflammation, NF-κB exhibits different activities in the lean vs. obese condition. NF-κB is required for expression of proinflammatory genes in the lean but not in the obese condition. NF-κB is required for inhibition of apoptosis in the obese condition, in which proinflammation is enhanced by NF-κB inactivation.


Assuntos
Adipócitos/metabolismo , Macrófagos/metabolismo , Obesidade/genética , Paniculite/genética , Magreza/genética , Fator de Transcrição RelA/genética , Adipócitos/patologia , Tecido Adiposo/imunologia , Tecido Adiposo/metabolismo , Animais , Inativação Gênica , Mediadores da Inflamação/metabolismo , Macrófagos/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Obesos , Obesidade/complicações , Obesidade/imunologia , Paniculite/metabolismo , Magreza/complicações , Magreza/imunologia , Fator de Transcrição RelA/metabolismo
16.
Rev Endocr Metab Disord ; 16(1): 47-54, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25526866

RESUMO

Inflammation regulates energy metabolism in both physiological and pathological conditions. Pro-inflammatory cytokines involves in energy regulation in several conditions, such as obesity, aging (calorie restriction), sports (exercise), and cancer (cachexia). Here, we introduce a view of integrative physiology to understand pro-inflammatory cytokines in the control of energy expenditure. In obesity, chronic inflammation is derived from energy surplus that induces adipose tissue expansion and adipose tissue hypoxia. In addition to the detrimental effect on insulin sensitivity, pro-inflammatory cytokines also stimulate energy expenditure and facilitate adipose tissue remodeling. In caloric restriction (CR), inflammatory status is decreased by low energy intake that results in less energy supply to immune cells to favor energy saving under caloric restriction. During physical exercise, inflammatory status is elevated due to muscle production of pro-inflammatory cytokines, which promote fatty acid mobilization from adipose tissue to meet the muscle energy demand. In cancer cachexia, chronic inflammation is elevated by the immune response in the fight against cancer. The energy expenditure from chronic inflammation contributes to weight loss. Immune tolerant cancer cells gains more nutrients during the inflammation. In these conditions, inflammation coordinates energy distribution and energy demand between tissues. If the body lacks response to the pro-inflammatory cytokines (Inflammation Resistance), the energy metabolism will be impaired leading to an increased risk for obesity. In contrast, super-induction of the inflammation activity leads to weight loss and malnutrition in cancer cachexia. In summary, inflammation is a critical component in the maintenance of energy balance in the body. Literature is reviewed in above fields to support this view.


Assuntos
Metabolismo Energético/fisiologia , Inflamação/metabolismo , Resistência à Insulina/fisiologia , Obesidade/metabolismo , Tecido Adiposo/metabolismo , Restrição Calórica , Homeostase/fisiologia , Humanos
17.
Biochim Biophys Acta ; 1832(12): 1980-8, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23816567

RESUMO

S6K (ribosomal S6 kinase p70, p70S6K) activation requires phosphorylation at two stages. The first phosphorylation is independent of insulin stimulation and mediated by an unknown kinase. The second phosphorylation is mediated by mTOR in insulin dependent manner. In this study, we identified JNK1 (c-Jun N-terminal kinase 1) as a kinase in the first phosphorylation. S6K protein was phosphorylated by JNK1 at S411 and S424 in the carboxyl terminal autoinhibitory domain. The phosphorylation was observed in kinase assay with purified S6K as a substrate, and in cells after JNK1 activation by TNF-α or MEKK1 expression. The phosphorylation was detected in JNK2 null cells, but not in JNK1 null cells after TNF-α treatment. When JNK1 activation was inhibited by MKK7 knockdown, the phosphorylation was blocked in cells. The phosphorylation led to S6K protein degradation in NF-κB deficient cells. The degradation was blocked by inhibition of proteasome activity with MG132. In wide type cells, the phosphorylation did not promote S6K degradation when IKK2 (IKKß, IκB kinase beta) was activated. Instead, the phosphorylation allowed S6K activation by mTOR, which stabilizes S6K protein. In IKK2 null cells or cells treated by IKK2 inhibitor, the phosphorylation led to S6K degradation. These data suggest that S6K is phosphorylated by JNK1 and the phosphorylation makes S6K protein unstable in the absence of IKK2 activation. This study provides a mechanism for regulation of S6K protein stability.


Assuntos
Ativação Enzimática/efeitos dos fármacos , Proteína Quinase 8 Ativada por Mitógeno/metabolismo , Subunidade p50 de NF-kappa B/fisiologia , Proteínas Quinases S6 Ribossômicas 90-kDa/metabolismo , Fator de Necrose Tumoral alfa/farmacologia , Ubiquitina/metabolismo , Animais , Western Blotting , Células Cultivadas , Embrião de Mamíferos/citologia , Embrião de Mamíferos/metabolismo , Fibroblastos/citologia , Fibroblastos/metabolismo , Células HEK293 , Humanos , Quinase I-kappa B/genética , Quinase I-kappa B/metabolismo , Imunoprecipitação , Masculino , Camundongos , Camundongos Knockout , Fosforilação , Proteólise , RNA Mensageiro/genética , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Proteínas Quinases S6 Ribossômicas 90-kDa/genética , Transdução de Sinais , Ubiquitinação
18.
Am J Physiol Endocrinol Metab ; 306(8): E929-36, 2014 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-24569592

RESUMO

Hepatocyte growth factor (HGF) is expressed as an angiogenic factor in adipose tissue. However, the molecular mechanism of Hgf expression remains largely unknown in the tissue. We addressed the issue by studying Hgf expression in adipocytes and macrophages. Hgf was expressed more in the stromal-vascular fraction than the adipocyte fraction. The expression was fivefold more in macrophages than the stromal-vascular faction and was reduced by 50% after macrophage deletion in adipose tissue. The expression was reduced by differentiation in adipocytes and by tumor necrosis factor-α or lipopolysaccharide treatment in macrophages. The expression was suppressed by nuclear factor (NF)-κB in C57BL/6 mice with NF-κB p65 overexpression under the aP2 gene promoter (aP2-p65 mice) but enhanced by inactivation of NF-κB p65 in mouse embryonic fibroblasts. The Hgf gene promoter was suppressed by p65 overexpression, which blocked peroxisome proliferator-activated receptor-γ (PPARγ) interaction with RNA polymerase II. The p65 activity was abolished by knockdown of histone deacetylase 3. Hgf expression was upregulated by hypoxia in vitro and in vivo. Compared with vascular endothelial growth factor (Vegf), which was predominately expressed in mature adipocytes, Hgf was mainly expressed in nonadipocytes, suggesting that Hgf and Vegf may have different cell sources in adipose tissue. In mechanism, Hgf expression is inhibited by NF-κB through suppression of PPARγ function in the Hgf gene promoter. Both Hgf and Vegf are induced by hypoxia. The study provides a molecular mechanism for the difference of inflammation and hypoxia in the regulation of angiogenic factors.


Assuntos
Tecido Adiposo/metabolismo , Fator de Crescimento de Hepatócito/genética , PPAR gama/fisiologia , Fator de Transcrição RelA/fisiologia , Células 3T3-L1 , Animais , Células Cultivadas , Regulação da Expressão Gênica , Células HEK293 , Fator de Crescimento de Hepatócito/metabolismo , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Obesos , Camundongos Transgênicos , Células NIH 3T3 , Fator de Transcrição RelA/genética
19.
Am J Physiol Regul Integr Comp Physiol ; 306(5): R352-62, 2014 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-24430883

RESUMO

Exaggerated GLP-1 and PYY secretion is thought to be a major mechanism in the reduced food intake and body weight after Roux-en-Y gastric bypass surgery. Here, we use complementary pharmacological and genetic loss-of-function approaches to test the role of increased signaling by these gut hormones in high-fat diet-induced obese rodents. Chronic brain infusion of a supramaximal dose of the selective GLP-1 receptor antagonist exendin-9-39 into the lateral cerebral ventricle significantly increased food intake and body weight in both RYGB and sham-operated rats, suggesting that, while contributing to the physiological control of food intake and body weight, central GLP-1 receptor signaling tone is not the critical mechanism uniquely responsible for the body weight-lowering effects of RYGB. Central infusion of the selective Y2R-antagonist BIIE0246 had no effect in either group, suggesting that it is not critical for the effects of RYGB on body weight under the conditions tested. In a recently established mouse model of RYGB that closely mimics surgery and weight loss dynamics in humans, obese GLP-1R-deficient mice lost the same amount of body weight and fat mass and maintained similarly lower body weight compared with wild-type mice. Together, the results surprisingly provide no support for important individual roles of either gut hormone in the specific mechanisms by which RYGB rats settle at a lower body weight. It is likely that the beneficial effects of bariatric surgeries are expressed through complex mechanisms that require combination approaches for their identification.


Assuntos
Derivação Gástrica , Receptores de Glucagon/metabolismo , Redução de Peso/fisiologia , Animais , Arginina/administração & dosagem , Arginina/análogos & derivados , Arginina/farmacologia , Benzazepinas/administração & dosagem , Benzazepinas/farmacologia , Composição Corporal , Peso Corporal/efeitos dos fármacos , Gorduras na Dieta , Ingestão de Alimentos , Metabolismo Energético , Receptor do Peptídeo Semelhante ao Glucagon 1 , Masculino , Camundongos , Camundongos Knockout , Atividade Motora , Obesidade/metabolismo , Obesidade/cirurgia , Consumo de Oxigênio , Fragmentos de Peptídeos/administração & dosagem , Fragmentos de Peptídeos/farmacologia , Ratos , Ratos Sprague-Dawley , Receptores de Glucagon/antagonistas & inibidores , Receptores de Glucagon/genética
20.
J AOAC Int ; 97(1): 50-7, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24672859

RESUMO

In the present study, an HPLC-DAD method was optimized for the quantitative determination of 6-gingerol, 6-shogaol, 8-gingerol, and 10-gingerol in ginger extracts. A chromatographic fingerprinting method was also established to differentiate and evaluate the ginger extracts for bioactivity. Twenty-one extracts were prepared by methods differing in ginger type (fresh versus dried), solvent, and extraction methods. The ANOVA analysis showed the methods' influence on the mean extraction yields of gingerols increased in the order of: high pressure-high temperature (HP)>blender (BD)>low pressure (LP). The optimal solvent to extract gingerols was found to be 95% ethanol. The type of ginger used had significant effects on the content of gingerols, but its overall influence depended on the solvent used. In order to maximize the extraction efficiency of gingerols, a combination of dry ginger, 95% ethanol, and the HP extraction method should be employed. The chromatographic fingerprints were obtained to differentiate the unknown components from all ginger extracts. The similarity of the chromatographic fingerprints was used to evaluate the differences among all extracts. It can be concluded that the chromatographic fingerprints are able to ensure the stability of each extract and have some correlation with the observed bioactivity.


Assuntos
Catecóis/química , Fracionamento Químico/métodos , Cromatografia Líquida de Alta Pressão/métodos , Cromatografia/métodos , Álcoois Graxos/química , Extratos Vegetais/química , Raízes de Plantas/química , Zingiber officinale/química
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