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Beige fat plays key roles in the regulation of systemic energy homeostasis; however, detailed mechanisms and safe strategy for its activation remain elusive. In this study, we discovered that local hyperthermia therapy (LHT) targeting beige fat promoted its activation in humans and mice. LHT achieved using a hydrogel-based photothermal therapy activated beige fat, preventing and treating obesity in mice without adverse effects. HSF1 is required for the effects since HSF1 deficiency blunted the metabolic benefits of LHT. HSF1 regulates Hnrnpa2b1 (A2b1) transcription, leading to increased mRNA stability of key metabolic genes. Importantly, analysis of human association studies followed by functional analysis revealed that the HSF1 gain-of-function variant p.P365T is associated with improved metabolic performance in humans and increased A2b1 transcription in mice and cells. Overall, we demonstrate that LHT offers a promising strategy against obesity by inducing beige fat activation via HSF1-A2B1 transcriptional axis.
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Tecido Adiposo Bege , Tecido Adiposo Branco , Hipertermia Induzida , Obesidade/terapia , Tecido Adiposo Bege/metabolismo , Tecido Adiposo Marrom/metabolismo , Tecido Adiposo Branco/metabolismo , Animais , Camundongos , Camundongos Endogâmicos C57BL , Obesidade/metabolismoRESUMO
Cholesterol metabolism is vital for multiple cancer progression, while how cholesterol affects lung, a low-cholesterol tissue, for cancer metastasis and the underlying mechanism remain unclear. In this study, we found that metastatic lung adenocarcinoma cells acquire cellular dehydrocholesterol and cholesterol by endogenous cholesterol biosynthesis, instead of uptake upon cholesterol treatment. Besides, we demonstrated that exogenous cholesterol functions as signaling molecule to induce FOXA3, a key transcription factor for lipid metabolism via GLI2. Subsequently, ChIP-seq analysis and molecular studies revealed that FOXA3 transcriptionally activated Hmgcs1, an essential enzyme of cholesterol biosynthesis, to induce endogenous dehydrocholesterol and cholesterol level for membrane composition change and cell migration. Conversely, FOXA3 knockdown or knockout blocked cholesterol biosynthesis and lung adenocarcinoma metastasis in mice. In addition, the potent FOXA3 inhibitor magnolol suppressed metastatic gene programs in lung adenocarcinoma patient-derived organoids (PDOs). Altogether, our findings shed light onto unique cholesterol metabolism and FOXA3 contribution to lung adenocarcinoma metastasis.
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Adenocarcinoma de Pulmão , Colesterol , Progressão da Doença , Fator 3-gama Nuclear de Hepatócito , Neoplasias Pulmonares , Colesterol/metabolismo , Adenocarcinoma de Pulmão/metabolismo , Adenocarcinoma de Pulmão/patologia , Adenocarcinoma de Pulmão/genética , Animais , Humanos , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/genética , Camundongos , Fator 3-gama Nuclear de Hepatócito/metabolismo , Fator 3-gama Nuclear de Hepatócito/genética , Linhagem Celular Tumoral , Regulação Neoplásica da Expressão Gênica , Movimento CelularRESUMO
Peroxisome proliferator-activated receptor γ (PPARγ) is a master regulator of adipocyte differentiation, glucolipid metabolism, and inflammation. Thiazolidinediones are PPARγ full agonists with potent insulin-sensitizing effects, whereas their oral usage is restricted because of unwanted side effects, including obesity and cardiovascular risks. Here, via virtual screening, microscale thermophoresis analysis, and molecular confirmation, we demonstrate that diosmin, a natural compound of wide and long-term clinical use, is a selective PPARγ modulator that binds to PPARγ and blocks PPARγ phosphorylation with weak transcriptional activity. Local diosmin administration in subcutaneous fat (inguinal white adipose tissue [iWAT]) improved insulin sensitivity and attenuated obesity via enhancing browning of white fat and energy expenditure. Besides, diosmin ameliorated inflammation in WAT and liver and reduced hepatic steatosis. Of note, we determined that iWAT local administration of diosmin did not exhibit obvious side effects. Taken together, the present study demonstrated that iWAT local delivery of diosmin protected mice from diet-induced insulin resistance, obesity, and fatty liver by blocking PPARγ phosphorylation, without apparent side effects, making it a potential therapeutic agent for the treatment of metabolic diseases.
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Tecido Adiposo Marrom , Tecido Adiposo Branco , Diosmina , Fígado Gorduroso , Resistência à Insulina , PPAR gama , Animais , Camundongos , Tecido Adiposo Branco/efeitos dos fármacos , Tecido Adiposo Branco/metabolismo , Dieta Hiperlipídica , Diosmina/farmacologia , Diosmina/metabolismo , Diosmina/uso terapêutico , Fígado Gorduroso/metabolismo , Inflamação/metabolismo , Camundongos Endogâmicos C57BL , Obesidade/metabolismo , PPAR gama/metabolismo , Tecido Adiposo Marrom/metabolismoRESUMO
BACKGROUND: 8-Oxoguanine DNA glycosylase (OGG1), a well-known DNA repair enzyme, has been demonstrated to promote lung fibrosis, while the specific regulatory mechanism of OGG1 during pulmonary fibrosis remains unclarified. METHODS: A bleomycin (BLM)-induced mouse pulmonary fibrosis model was established, and TH5487 (the small molecule OGG1 inhibitor) and Mitochondrial division inhibitor 1 (Mdivi-1) were used for administration. Histopathological injury of the lung tissues was assessed. The profibrotic factors and oxidative stress-related factors were examined using the commercial kits. Western blot was used to examine protein expression and immunofluorescence analysis was conducted to assess macrophages polarization and autophagy. The conditional medium from M2 macrophages was harvested and added to HFL-1 cells for culture to simulate the immune microenvironment around fibroblasts during pulmonary fibrosis. Subsequently, the loss- and gain-of function experiments were conducted to further confirm the molecular mechanism of OGG1/PINK1. RESULTS: In BLM-induced pulmonary fibrosis, OGG1 was upregulated while PINK1/Parkin was downregulated. Macrophages were activated and polarized to M2 phenotype. TH5487 administration effectively mitigated pulmonary fibrosis, M2 macrophage polarization, oxidative stress and mitochondrial dysfunction while promoted PINK1/Parkin-mediated mitophagy in lung tissues of BLM-induced mice, which was partly hindered by Mdivi-1. PINK1 overexpression restricted M2 macrophages-induced oxidative stress, mitochondrial dysfunction and mitophagy inactivation in lung fibroblast cells, and OGG1 knockdown could promote PINK1/Parkin expression and alleviate M2 macrophages-induced mitochondrial dysfunction in HFL-1 cells. CONCLUSION: OGG1 inhibition protects against pulmonary fibrosis, which is partly via activating PINK1/Parkin-mediated mitophagy and retarding M2 macrophage polarization, providing a therapeutic target for pulmonary fibrosis.
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Bleomicina , DNA Glicosilases , Modelos Animais de Doenças , Macrófagos , Mitofagia , Proteínas Quinases , Fibrose Pulmonar , Animais , Mitofagia/efeitos dos fármacos , Fibrose Pulmonar/metabolismo , Fibrose Pulmonar/induzido quimicamente , Fibrose Pulmonar/etiologia , Fibrose Pulmonar/patologia , DNA Glicosilases/metabolismo , DNA Glicosilases/genética , Camundongos , Macrófagos/metabolismo , Proteínas Quinases/metabolismo , Bleomicina/efeitos adversos , Masculino , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitina-Proteína Ligases/genética , Estresse Oxidativo/efeitos dos fármacos , Camundongos Endogâmicos C57BL , Ativação de Macrófagos , Humanos , QuinazolinonasRESUMO
Complement factor H-related protein (CFHR) plays an important role in regulating complement activation and defensive responses. The function of CFHR2 (complement factor H related 2), a member of the CFHR family, in fish remains unclear. Here, we report the genetic relationship, expression characteristics and regulatory mechanism of cfhl5 (complement factor H like 5) gene, which encodes CFHR2 in Chinese tongue sole. We observed that the cfhl5 gene was widely expressed in several tissues, such as brain, heart and immune organs, and was most abundantly expressed in liver. After injection with Vibrio harveyi, the expression of cfhl5 was up-regulated significantly in liver, spleen and kidney at 12 or 24 hours post infection (hpi), suggesting an involvement of this gene in the acute immune response. Knockdown of cfhl5 in liver cells significantly up-regulated the expression of the pro-inflammatory cytokines tnf-α (tumor necrosis factor-alpha) and il1ß (interleukin-1beta), the immunomodulatory factor il10 (interleukin-10) and the lectin complement pathway gene masp1 (MBL-associated serine protease 1), and down-regulated the expression of complement components c3 (complement 3) and cfi (complement factor I). In our previous work, we found that cfhl5 gene was significantly higher methylated and lower expressed in the resistant family compared with the susceptible family. Therefore, we used dual-luciferase reporter system to determine the effect of DNA methylation on this gene and found that DNA methylation could inhibit the promoter activity to reduce its expression. These results demonstrated that the expression of cfhl5 is regulated by DNA methylation, and this gene might play an important role in the immune response by regulating the expression of cytokines and complement components genes in Chinese tongue sole.
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Doenças dos Peixes , Proteínas de Peixes , Linguados , Regulação da Expressão Gênica , Imunidade Inata , Vibrioses , Vibrio , Animais , Vibrio/fisiologia , Doenças dos Peixes/imunologia , Vibrioses/imunologia , Vibrioses/veterinária , Proteínas de Peixes/genética , Proteínas de Peixes/imunologia , Imunidade Inata/genética , Linguados/imunologia , Linguados/genética , Regulação da Expressão Gênica/imunologia , Perfilação da Expressão Gênica/veterinária , FilogeniaRESUMO
Frequent outbreaks of infectious diseases in aquaculture have led to significant economic losses. The leopard coral grouper (Plectropomus leopardus) often suffers from vibriosis. Improving host immunity presents a superior strategy for disease control, with minimal side effects compared to the use of antibiotics, highlighting the necessity of exploring the mechanisms underlying the fish's response to pathogen infections. Here, we conducted a comparative metabolomic analysis on the livers of the P. leopardus infected with Vibrio harveyi. A total of 1124 differential metabolites (DMs) were identified, with 190, 218, 359, and 353 DMs being identified at 6, 12, 24, and 48 h post-infection (hpi), respectively. Then, based on the time series analysis, we found that the lipid metabolism pathways were modulated in response to the Vibrio infection, with an increase in the quantity of eicosanoids and gycerophospholipids (GPLs), as well as a decrease in the quantity of bile acids (BAs), vitamin D, and sex hormones. Furthermore, 13 enriched pathways involving 31 DMs were identified through KEGG (Kyoto Encyclopedia of Genes and Genomes) enrichment analyses. We identified histamine, 15(S)-HpETE, and anandamide in the transient receptor potential (TRP) channels pathway, as well as (7S,8S)-DiHODE, 5S,8R-DiHODE, and 13(S)-HpODE in the linoleic acid (LA) metabolism pathway. The DM levels increased, which may be attributed to inflammation. The DMs in the thyroid hormone synthesis pathway were identified, and the contents of nicotinamide adenine dinucleotide phosphate (NADPH) and glutathione (GSH) decreased, which may be crucial in antioxidants. Our findings highlighted the dynamic adjustments in lipid metabolism and the response to inflammation and oxidative stress during the infection of V. harveyi in P. leopardus. This study not only deepens our understanding of the metabolic underpinnings of fish immune responses but also lays the groundwork for research into functional metabolomics and mechanisms of disease resistance.
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BACKGROUND: Receptor for Advanced Glycated Endproducts (RAGE) plays a major role in the inflammatory response to infectious and toxin induced acute lung injury. We tested the hypothesis that a RAGE blocking antibody when administered after the onset of injury can reduce lung inflammation compared to control antibody. METHODS: Male and female C57BL/6 (WT) mice were used. Forty-six received lipopolysaccharide (LPS) and 26 PBS by nasal instillation on day one, repeated on day three. On day 2, 36 mice receiving LPS were divided into two groups of 18, one treated with 200 µg of non-immune isotype control IgG and the second group treated with 200 µg of anti-RAGE Ab, each dose divided between IV and IP. Ten of the 46 were not treated. On day 4, before euthanasia, mice were injected with fluorescein isothiocyanate (FITC) labelled albumen. BALF and serum samples were collected as well as lung tissue for immunohistochemistry (IHC). BALF was analyzed for cell (leukocyte) counts, for FITC BALF/serum ratios indicating pulmonary vascular leak, and for cytokines/chemokines using bead based multiplex assays. Quantitative IHC was performed for MPO and RAGE. RESULTS: Ten LPS mice showed minimal inflammation by all measures indicating poor delivery of LPS and were excluded from analysis leaving n = 11 in the LPS + IgG group and n = 12 in the LPS + anti-RAGE group. BALF cell counts were low in the PBS administered mice (4.9 ± 2.1 × 105/ml) and high in the LPS injured untreated mice (109 ± 34) and in the LPS + IgG mice (91 ± 54) while in comparison, LPS + anti-RAGE ab mice counts were significantly lower (51.3 ± 18 vs. LPS + IgG, P = 0.03). The BALF/serum FITC ratios were lower for the LPS + anti-RAGE mice than for the LPS + IgG mice indicating less capillary leakiness. Quantitative IHC RAGE staining was lower in the LPS + anti-RAGE ab mice than in the LPS + IgG treated mice (P = 0.02). CONCLUSIONS: These results describe a four-day LPS protocol to sustain lung injury and allow for treatment and suggests that treatment aimed at blocking RAGE when given after onset of injury can reduce lung inflammation.
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Lesão Pulmonar Aguda , Pneumonia , Feminino , Masculino , Animais , Camundongos , Lipopolissacarídeos/toxicidade , Fluoresceína-5-Isotiocianato/metabolismo , Camundongos Endogâmicos C57BL , Lesão Pulmonar Aguda/tratamento farmacológico , Pulmão/metabolismo , Inflamação/metabolismo , Pneumonia/induzido quimicamente , Pneumonia/metabolismo , Imunoglobulina G/metabolismoRESUMO
A novel gold-catalyzed [4 + 1] heterocyclization of nonactivated alkyne and hydroxamic acid is developed for the regiospecific synthesis of 5-methyl-1,4,2-dioxazole, which is an important structural motif in various bioactive molecules. The current methodology is characterized by high efficiency, simple operation, mild reaction conditions, and good functional group compatibility. Moreover, gram-scale synthesis and synthetic application toward bioactive molecular skeletons have been realized.
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Alcinos , Ouro , Alcinos/química , Ouro/química , Ácidos Hidroxâmicos/química , Ciclização , CatáliseRESUMO
Chinese tongue sole (Cynoglossus semilaevis) is an economically important marine fish in China. However, vibriosis has caused huge mortality and economic losses in its culturing industry. To reveal the effect of DNA methylation on the resistance to vibriosis in tongue sole, we conducted RNA sequencing and whole genome bisulfite sequencing (WGBS), and compared the gene expressions and DNA methylation patterns between the resistant and susceptible families. We identified a total of 741 significantly differentially expressed genes (DEGs) in kidney and 17460 differentially methylated genes (DMGs), which were both enriched in immune-related pathways, such as "cAMP signaling pathway" and "NOD-like receptor signaling pathway". Through the correlation analysis of DEGs and DMGs, we identified two important immune pathways, including "complement and coagulation cascades", and "cytokine-cytokine receptor interaction", which played important roles in regulating the inflammation level and immune homeostasis. For example, the expression of proinflammatory cytokine il17c was down-regulated under the regulation of DNA methylation; in addition, the expression of protease-activated receptor 3 (par3) was up-regulated, which could induce the up-expressionof il8. These results demonstrated that the regulation of DNA methylation on the genes involved in immune responses might contribute to the resistance to vibriosis in tongue sole, and provided a basis for the control of diseases in fish aquaculture.
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Linguados , Linguado , Vibrioses , Humanos , Animais , Metilação de DNA , Linguado/metabolismo , Citocinas/genéticaRESUMO
BACKGROUND AND AIMS: Nonalcoholic fatty liver disease (NAFLD) is characterized by accumulation of excessive triglycerides (TGs) in hepatocytes. Obesity is a major risk factor for developing fatty liver, although the intracellular molecular basis remains largely unclear. N6 -methyladenosine (m6 A) RNA methylation is the most common internal modification in eukaryotic mRNA. APPROACH AND RESULTS: In the present study, by m6 A sequencing and RNA sequencing, we found that both m6 A enrichment and mRNA expression of lipogenic genes were significantly increased in leptin-receptor-deficient db/db mice. Importantly, our results showed that YT521-B homology domain-containing 2 (Ythdc2), an m6 A reader, was markedly down-regulated in livers of obese mice and NAFLD patients. Suppression of Ythdc2 in livers of lean mice led to TG accumulation, whereas ectopic overexpression of Ythdc2 in livers of obese mice improved liver steatosis and insulin resistance. Mechanistically, we found that Ythdc2 could bind to mRNA of lipogenic genes, including sterol regulatory element-binding protein 1c, fatty acid synthase, stearoyl-CoA desaturase 1, and acetyl-CoA carboxylase 1, to decrease their mRNA stability and inhibit gene expression. CONCLUSIONS: Our findings describe an important role of the m6 A reader, Ythdc2, for regulation of hepatic lipogenesis and TG homeostasis, which might provide a potential target for treating obesity-related NAFLD.
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Lipogênese/genética , Fígado/embriologia , Hepatopatia Gordurosa não Alcoólica/etiologia , Obesidade/complicações , RNA Helicases/metabolismo , Estabilidade de RNA/genética , Animais , Ácido Graxo Sintases/metabolismo , Células Hep G2 , Hepatócitos/metabolismo , Humanos , Fígado/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Obesos , Hepatopatia Gordurosa não Alcoólica/enzimologia , Hepatopatia Gordurosa não Alcoólica/genética , Hepatopatia Gordurosa não Alcoólica/patologia , Obesidade/enzimologia , Obesidade/genética , Obesidade/patologia , RNA Helicases/genética , Proteína de Ligação a Elemento Regulador de Esterol 1/metabolismo , Triglicerídeos/metabolismoRESUMO
BACKGROUND: Comparative-effectiveness studies using real-world data (RWD) can be susceptible to surveillance bias. In solid tumor oncology studies, analyses of endpoints such as progression-free survival (PFS) are based on progression events detected by imaging assessments. This study aimed to evaluate the potential bias introduced by differential imaging assessment frequency when using electronic health record (EHR)-derived data to investigate the comparative effectiveness of cancer therapies. METHODS: Using a nationwide de-identified EHR-derived database, we first analyzed imaging assessment frequency patterns in patients diagnosed with advanced non-small cell lung cancer (aNSCLC). We used those RWD inputs to develop a discrete event simulation model of two treatments where disease progression was the outcome and PFS was the endpoint. Using this model, we induced bias with differential imaging assessment timing and quantified its effect on observed versus true treatment effectiveness. We assessed percent bias in the estimated hazard ratio (HR). RESULTS: The frequency of assessments differed by cancer treatment types. In simulated comparative-effectiveness studies, PFS HRs estimated using real-world imaging assessment frequencies differed from the true HR by less than 10% in all scenarios (range: 0.4% to -9.6%). The greatest risk of biased effect estimates was found comparing treatments with widely different imaging frequencies, most exaggerated in disease settings where time to progression is very short. CONCLUSIONS: This study provided evidence that the frequency of imaging assessments to detect disease progression can differ by treatment type in real-world patients with cancer and may induce some bias in comparative-effectiveness studies in some situations.
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Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Viés , Carcinoma Pulmonar de Células não Pequenas/diagnóstico por imagem , Carcinoma Pulmonar de Células não Pequenas/epidemiologia , Humanos , Neoplasias Pulmonares/diagnóstico por imagem , Intervalo Livre de ProgressãoRESUMO
BACKGROUND & AIMS: Chronic endoplasmic reticulum (ER) stress in the liver has been shown to play a causative role in non-alcoholic fatty liver disease (NAFLD) progression, yet the underlying molecular mechanisms remain to be elucidated. Forkhead box A3 (FOXA3), a member of the FOX family, plays critical roles in metabolic homeostasis, although its possible functions in ER stress and fatty liver progression are unknown. METHODS: Adenoviral delivery, siRNA delivery, and genetic knockout mice were used to crease FOXA3 gain- or loss-of-function models. Tunicamycin (TM) and a high-fat diet (HFD) were used to induce acute or chronic ER stress in mice. Chromatin immunoprecipiation (ChIP)-seq, luciferase assay, and adenoviral-mediated downstream gene manipulations were performed to reveal the transcriptional axis involved. Key axis protein levels in livers from healthy donors and patients with NAFLD were assessed via immunohistochemical staining. RESULTS: FOXA3 transcription is specifically induced by XBP1s upon ER stress. FOXA3 exacerbates the excessive lipid accumulation caused by the acute ER-inducer TM, whereas FOXA3 deficiency in hepatocytes and mice alleviates it. Importantly, FOXA3 deficiency in mice reduced diet-induced chronic ER stress, fatty liver, and insulin resistance. In addition, FOXA3 suppression via siRNA or adeno-associated virus delivery ameliorated the fatty liver phenotype in HFD-fed and db/db mice. Mechanistically, ChIP-Seq analysis revealed that FOXA3 directly regulates Period1 (Per1) transcription, which in turn promotes the expression of lipogenic genes, including Srebp1c, thus enhancing lipid synthesis. Of pathophysiological significance, FOXA3, PER1, and SREBP1c levels were increased in livers of obese mice and patients with NAFLD. CONCLUSION: The present study identified FOXA3 as the bridging molecule that links ER stress and NAFLD progression. Our results highlighted the role of the XBP1s-FOXA3-PER1/Srebp1c transcriptional axis in the development of NAFLD and identified FOXA3 as a potential therapeutic target for fatty liver disease. LAY SUMMARY: The molecular mechanisms linking endoplasmic reticulum stress to non-alcoholic fatty liver disease (NAFLD) progression remain undefined. Herein, via in vitro and in vivo analysis, we identified Forkhead box A3 (FOXA3) as a key bridging molecule. Of pathophysiological significance, FOXA3 protein levels were increased in livers of obese mice and patients with NAFLD, indicating that FOXA3 could be a potential therapeutic target in fatty liver disease.
Assuntos
Estresse do Retículo Endoplasmático , Fator 3-gama Nuclear de Hepatócito/metabolismo , Animais , Descoberta de Drogas , Hepatócitos/metabolismo , Humanos , Lipogênese/genética , Camundongos , Camundongos Knockout , Hepatopatia Gordurosa não Alcoólica/metabolismo , Proteínas Circadianas Period/metabolismo , Transdução de Sinais , Proteína de Ligação a Elemento Regulador de Esterol 1/metabolismo , Proteína 1 de Ligação a X-Box/metabolismoRESUMO
Acute respiratory distress syndrome (ARDS) is characterized by pulmonary edema and poor gas exchange resulting from severe inflammatory lung injury. Neutrophilic infiltration and increased pulmonary vascular permeability are hallmarks of early ARDS and precipitate a self-perpetuating cascade of inflammatory signaling. The biochemical processes initiating these events remain unclear. Typically associated with extracellular matrix degradation, recent data suggest matrix metalloproteinases (MMPs) are regulators of pulmonary inflammation. To demonstrate that inhalation of a broad MMP inhibitor attenuates LPS induced pulmonary inflammation. Nebulized CGS27023AM (CGS) was administered to LPS-injured mice. Pulmonary CGS levels were examined by mass spectroscopy. Inflammatory scoring of hematoxylin-eosin sections, examination of vascular integrity via lung wet/dry and bronchoalveolar lvage/serum FITC-albumin ratios were performed. Cleaved caspase-3 levels were also assessed. Differential cell counts and pulse-chase labeling were utilized to determine the effects of CGS on neutrophil migration. The effects of CGS on human neutrophil migration and viability were examined using Boyden chambers and MTT assays. Nebulization successfully delivered CGS to the lungs. Treatment decreased pulmonary inflammatory scores, edema, and apoptosis in LPS treated animals. Neutrophil chemotaxis was reduced by CGS treatment, with inhalation causing significant reductions in both the total number and newly produced bromodeoxyuridine-positive cells infiltrating the lung. Mechanistic studies on cells isolated from humans demonstrate that CGS-treated neutrophils exhibit decreased chemotaxis. The protective effect observed following treatment with a nonspecific MMP inhibitor indicates that one or more MMPs mediate the development of pulmonary edema and neutrophil infiltration in response to LPS injury. In accordance with this, inhaled MMP inhibitors warrant further study as a potential new therapeutic avenue for treatment of acute lung injury.
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Lesão Pulmonar Aguda/tratamento farmacológico , Endotoxinas/farmacologia , Inibidores de Metaloproteinases de Matriz/farmacologia , Pneumonia/tratamento farmacológico , Lesão Pulmonar Aguda/metabolismo , Humanos , Lipopolissacarídeos/farmacologia , Infiltração de Neutrófilos/efeitos dos fármacos , Infiltração de Neutrófilos/fisiologia , Neutrófilos/efeitos dos fármacos , Neutrófilos/metabolismo , Pneumonia/induzido quimicamente , Pneumonia/metabolismo , Fator de Necrose Tumoral alfa/metabolismoRESUMO
Glucocorticoids (GCs) are widely prescribed anti-inflammatory agents, but their chronic use leads to undesirable side effects such as excessive expansion of adipose tissue. We have recently shown that the forkhead box protein A3 (Foxa3) is a calorie-hoarding factor that regulates the selective enlargement of epididymal fat depots and suppresses energy expenditure in a nutritional- and age-dependent manner. It has been demonstrated that Foxa3 levels are elevated in adipose depots in response to high-fat diet regimens and during the aging process; however no studies to date have elucidated the mechanisms that control Foxa3's expression in fat. Given the established effects of GCs in increasing visceral adiposity and in reducing thermogenesis, we assessed the existence of a possible link between GCs and Foxa3. Computational prediction analysis combined with molecular studies revealed that Foxa3 is regulated by the glucocorticoid receptor (GR) in preadipocytes, adipocytes, and adipose tissues and is required to facilitate the binding of the GR to its target gene promoters in fat depots. Analysis of the long-term effects of dexamethasone treatment in mice revealed that Foxa3 ablation protects mice specifically against fat accretion but not against other pathological side effects elicited by this synthetic GC in tissues such as liver, muscle, and spleen. In conclusion our studies provide the first demonstration, to our knowledge, that Foxa3 is a direct target of GC action in adipose tissues and point to a role of Foxa3 as a mediator of the side effects induced in fat tissues by chronic treatment with synthetic steroids.
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Tecido Adiposo/fisiologia , Fator 3-gama Nuclear de Hepatócito/fisiologia , Receptores de Glucocorticoides/fisiologia , Tecido Adiposo/metabolismo , Animais , Glucocorticoides/efeitos adversos , Hiperlipidemias/genética , Camundongos , Regiões Promotoras Genéticas , Transcrição GênicaRESUMO
Sphingolipids are a diverse class of essential cellular lipids that function as structural membrane components and as signaling molecules. Cells acquire sphingolipids by both de novo biosynthesis and recycling of exogenous sphingolipids. The individual importance of these pathways for the generation of essential sphingolipids in differentiated cells is not well understood. To investigate the requirement for de novo sphingolipid biosynthesis in adipocytes, a cell type with highly regulated lipid metabolism, we generated mice with an adipocyte-specific deletion of Sptlc1 Sptlc1 is an obligate subunit of serine palmitoyltransferase, the enzyme responsible for the first and rate-limiting step of de novo sphingolipid biosynthesis. These mice, which initially developed adipose tissue, exhibited a striking age-dependent loss of adipose tissue accompanied by evidence of adipocyte death, increased macrophage infiltration, and tissue fibrosis. Adipocyte differentiation was not affected by the Sptlc1 deletion. The mice also had elevated fasting blood glucose, fatty liver, and insulin resistance. Collectively, these data indicate that de novo sphingolipid biosynthesis is required for adipocyte cell viability and normal metabolic function and that reduced de novo sphingolipid biosynthesis within adipocytes is associated with adipocyte death, adipose tissue remodeling, and metabolic dysfunction.
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Adipócitos/citologia , Homeostase , Serina C-Palmitoiltransferase/genética , Esfingolipídeos/biossíntese , Adiposidade , Animais , Diferenciação Celular , Sobrevivência Celular , Deleção de Genes , Inflamação , Resistência à Insulina , Metabolismo dos Lipídeos , Lipogênese , Macrófagos/metabolismo , Camundongos , Camundongos Knockout , Serina C-Palmitoiltransferase/metabolismoRESUMO
PURPOSE: An association of Lynch syndrome (LS) with breast cancer has been long suspected; however, there have been insufficient data to address this question for each of the LS genes individually. METHODS: We conducted a retrospective review of personal and family history in 423 women with pathogenic or likely pathogenic germ-line variants in MLH1 (N = 65), MSH2 (N = 94), MSH6 (N = 140), or PMS2 (N = 124) identified via clinical multigene hereditary cancer testing. Standard incidence ratios (SIRs) of breast cancer were calculated by comparing breast cancer frequencies in our study population with those in the general population (Surveillance, Epidemiology, and End Results 18 data). RESULTS: When evaluating by gene, the age-standardized breast cancer risks for MSH6 (SIR = 2.11; 95% confidence interval (CI), 1.56-2.86) and PMS2 (SIR = 2.92; 95% CI, 2.17-3.92) were associated with a statistically significant risk for breast cancer whereas no association was observed for MLH1 (SIR = 0.87; 95% CI, 0.42-1.83) or MSH2 (SIR = 1.22; 95% CI, 0.72-2.06). CONCLUSION: Our data demonstrate that two LS genes, MSH6 and PMS2, are associated with an increased risk for breast cancer and should be considered when ordering genetic testing for individuals who have a personal and/or family history of breast cancer.
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Neoplasias da Mama/genética , Neoplasias Colorretais Hereditárias sem Polipose/genética , Proteínas de Ligação a DNA/genética , Endonuclease PMS2 de Reparo de Erro de Pareamento/genética , Adulto , Idoso , Neoplasias da Mama/complicações , Neoplasias da Mama/patologia , Neoplasias Colorretais Hereditárias sem Polipose/complicações , Neoplasias Colorretais Hereditárias sem Polipose/patologia , Feminino , Estudos de Associação Genética , Predisposição Genética para Doença , Testes Genéticos , Mutação em Linhagem Germinativa/genética , Humanos , Anamnese , Pessoa de Meia-Idade , Proteína 1 Homóloga a MutL/genética , Proteína 2 Homóloga a MutS/genética , Estudos Retrospectivos , Fatores de RiscoRESUMO
We investigate coherent controlling single-photon nonreciprocal propagation in a pair of waveguides chirally coupled to an atom by using a classical optical field. The results show that for a nonresonant photon, the perfect single-photon nonreciprocal propagation can be realized by adjusting the Rabi frequency and detuning. Furthermore, the nonreciprocal propagation is switchable by using the classic field. The calculated results also show that the system can be used as a frequency filter to filter out some special frequencies for single-photon nonreciprocal propagation. The influences of nonperfect chiral coupling and dissipations on the nonreciprocal propagation are also shown.
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Aging is associated with increased adiposity and diminished thermogenesis, but the critical transcription factors influencing these metabolic changes late in life are poorly understood. We recently demonstrated that the winged helix factor forkhead box protein A3 (Foxa3) regulates the expansion of visceral adipose tissue in high-fat diet regimens; however, whether Foxa3 also contributes to the increase in adiposity and the decrease in brown fat activity observed during the normal aging process is currently unknown. Here we report that during aging, levels of Foxa3 are significantly and selectively up-regulated in brown and inguinal white fat depots, and that midage Foxa3-null mice have increased white fat browning and thermogenic capacity, decreased adipose tissue expansion, improved insulin sensitivity, and increased longevity. Foxa3 gain-of-function and loss-of-function studies in inguinal adipose depots demonstrated a cell-autonomous function for Foxa3 in white fat tissue browning. Furthermore, our analysis revealed that the mechanisms of Foxa3 modulation of brown fat gene programs involve the suppression of peroxisome proliferator activated receptor γ coactivtor 1 α (PGC1α) levels through interference with cAMP responsive element binding protein 1-mediated transcriptional regulation of the PGC1α promoter. Overall, our data demonstrate a role for Foxa3 in energy expenditure and in age-associated metabolic disorders.
Assuntos
Envelhecimento/metabolismo , Fator 3-gama Nuclear de Hepatócito/metabolismo , Tecido Adiposo Marrom/metabolismo , Tecido Adiposo Branco/metabolismo , Adiposidade/genética , Adiposidade/fisiologia , Envelhecimento/genética , Animais , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Metabolismo Energético/genética , Metabolismo Energético/fisiologia , Fator 3-gama Nuclear de Hepatócito/deficiência , Fator 3-gama Nuclear de Hepatócito/genética , Resistência à Insulina/genética , Resistência à Insulina/fisiologia , Longevidade/genética , Longevidade/fisiologia , Masculino , Camundongos , Camundongos Knockout , Obesidade/genética , Obesidade/metabolismo , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo , Regiões Promotoras Genéticas , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Termogênese/genética , Termogênese/fisiologia , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Regulação para CimaRESUMO
Increasing evidence indicates that transcription and alternative splicing are coordinated processes; however, our knowledge of specific factors implicated in both functions during the process of adipocyte differentiation is limited. We have previously demonstrated that the zinc finger protein ZNF638 plays a role as a transcriptional coregulator of adipocyte differentiation via induction of PPARγ in cooperation with CCAAT/enhancer binding proteins (C/EBPs). Here we provide new evidence that ZNF638 is localized in nuclear bodies enriched with splicing factors, and through biochemical purification of ZNF638's interacting proteins in adipocytes and mass spectrometry analysis, we show that ZNF638 interacts with splicing regulators. Functional analysis of the effects of ectopic ZNF638 expression on a minigene reporter demonstrated that ZNF638 is sufficient to promote alternative splicing, a function enhanced through its recruitment to the minigene promoter at C/EBP responsive elements via C/EBP proteins. Structure-function analysis revealed that the arginine/serine-rich motif and the C-terminal zinc finger domain required for speckle localization are necessary for the adipocyte differentiation function of ZNF638 and for the regulation of the levels of alternatively spliced isoforms of lipin1 and nuclear receptor co-repressor 1. Overall, our data demonstrate that ZNF638 participates in splicing decisions and that it may control adipogenesis through regulation of the relative amounts of differentiation-specific isoforms.
Assuntos
Processamento Alternativo , Precursores de RNA/metabolismo , Fatores de Transcrição/fisiologia , Células 3T3-L1 , Transporte Ativo do Núcleo Celular , Adipogenia , Animais , Linhagem Celular Tumoral , Proteínas de Ligação a DNA , Células HEK293 , Humanos , Camundongos , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Estrutura Terciária de Proteína , Precursores de RNA/genética , Proteínas de Ligação a RNARESUMO
OBJECTIVE: Graves' disease (GD) is a common autoimmune disease involved autoantibody production. Although we previously reported that osteopontin (OPN), a proinflammatory protein, affected development of GD through NF-κB activation, little is known about the role of OPN in regulating immunoglobulin production in GD. CD40 Ligand (CD40L) is expressed on the surface of activated CD4+T cells and costimulates CD40 on B cells, stimulating production of immunoglobulins, a process which has been reported to play a vital role in immunological signalling transduction in several autoimmune diseases. This study sought to characterize the relationship between CD40L and GD development, as well as investigating the role of OPN in modulating immunoglobulin production in GD via CD40L. METHODS: Forty incident patients with GD, twenty-one patients with GD in remission and twenty-seven healthy controls were recruited. Both membrane-bound and soluble forms of CD40L were measured, and their correlations with clinical parameters were studied. In addition, correlation between OPN and CD40L level was also examined. Furthermore, we studied the regulatory effect of OPN on CD40L in CD4+T cells. RESULTS: We demonstrated that the CD40L levels were enhanced in patients with GD and recovered in patients with GD in remission. CD40L levels correlated with clinical GD diagnostic parameters and OPN concentration. Moreover, human recombinant OPN and plasma samples from patients with GD increased CD40L expression, which could be significantly suppressed by OPN monoclonal antibody. In addition, CD40L antibody blocked the immunoglobulin production augmented by OPN in cultured peripheral blood mononuclear cells (PBMCs), isolated from patients with GD and healthy subjects. CONCLUSION: These results indicate that CD40L is induced by OPN and serves as the downstream effector of OPN for immunoglobulin production in GD development.