Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 23
Filtrar
Mais filtros








Base de dados
Intervalo de ano de publicação
1.
PLoS One ; 18(12): e0296281, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38153951

RESUMO

OBJECTIVE: In December 2019, a novel pneumonia associated with the 2019 coronavirus emerged unexpectedly. However, limited data exist on the effects of COVID-19 on ACTH and cortisol levels. To address this gap in knowledge, we conducted a meta-analysis of published studies on the relationship between COVID-19 patients and their ACTH and cortisol levels. METHODS: We conducted a thorough search of the PubMed, Embase, Cochrane Library, and Web of Science databases up until May 2023. We assessed the relevance of each study we found, specifically looking for studies that reported on ACTH and cortisol levels in COVID-19 patients. We calculated weighted mean differences (WMD) and 95% confidence intervals (CI) to investigate the relationship between ACTH and cortisol levels in COVID-19 patients. We evaluated the quality of each study using the Newcastle Ottawa scale (NOS), and we assessed publication bias using Begg's rank correlation test, Egger's test, and funnel plot. We conducted our meta-analysis using the Stata 12.0 (Stata Corporation, TX). RESULTS: Our search yielded nine studies that met our inclusion criteria, which included a total of 440 COVID-19 patients and 474 controls, with data up to May 2023. Seven of these studies reported on ACTH levels, and six studies reported on cortisol levels. Our findings revealed that COVID-19 patients had significantly higher levels of cortisol compared to controls (WMD 3.46 (95% CI 2.29 to 4.62)). However, there was no significant difference in ACTH levels between COVID-19 patients and controls (WMD 1.58 (95% CI -5.79 to 8.94)). CONCLUSIONS: This meta-analysis indicates a potential relationship between elevated cortisol levels and COVID-19 infection. However, more well-designed, adequately powered, randomized controlled trial will be needed to assess the use of cortisol in patients with COVID-19 infection.


Assuntos
COVID-19 , Humanos , Hidrocortisona , Hormônio Adrenocorticotrópico
2.
JHEP Rep ; 5(4): 100687, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36923240

RESUMO

Background & Aims: Acetaminophen (APAP)-induced acute liver injury (AILI) is a leading cause of acute liver failure (ALF). N-acetylcysteine (NAC) is only effective within 24 h after APAP intoxication, raising an urgent need for alternative approaches to treat this disease. This study aimed to test whether cathelicidin (Camp), which is a protective factor in chronic liver diseases, protects mice against APAP-induced liver injury and ALF. Methods: A clinically relevant AILI model and an APAP-induced ALF model were generated in mice. Genetic and pharmacological approaches were used to interfere with the levels of cathelicidin in vivo. Results: An increase in hepatic pro-CRAMP/CRAMP (the precursor and mature forms of mouse cathelicidin) was observed in APAP-intoxicated mice. Upregulated cathelicidin was derived from liver-infiltrating neutrophils. Compared with wild-type littermates, Camp knockout had no effect on hepatic injury but dampened hepatic repair in AILI and reduced survival in APAP-induced ALF. CRAMP administration reversed impaired liver recovery observed in APAP-challenged Camp knockout mice. Delayed CRAMP, CRAMP(1-39) (the extended form of CRAMP), or LL-37 (the mature form of human cathelicidin) treatment exhibited a therapeutic benefit for AILI. Co-treatment of cathelicidin and NAC in AILI displayed a stronger hepatoprotective effect than NAC alone. A similar additive effect of CRAMP(1-39)/LL-37 and NAC was observed in APAP-induced ALF. The pro-reparative role of cathelicidin in the APAP-damaged liver was attributed to an accelerated resolution of inflammation at the onset of liver repair, possibly through enhanced neutrophil phagocytosis of necrotic cell debris in an autocrine manner. Conclusions: Cathelicidin reduces APAP-induced liver injury and ALF in mice by promoting liver recovery via facilitating inflammation resolution, suggesting a therapeutic potential for late-presenting patients with AILI with or without ALF. Impact and implications: Acetaminophen-induced acute liver injury is a leading cause of acute liver failure. The efficacy of N-acetylcysteine, the only clinically approved drug against acetaminophen-induced acute liver injury, is significantly reduced for late-presenting patients. We found that cathelicidin exhibits a great therapeutic potential in mice with acetaminophen-induced liver injury or acute liver failure, which makes up for the limitation of N-acetylcysteine therapy by specifically promoting liver repair after acetaminophen intoxication. The pro-reparative role of cathelicidin, as a key effector molecule of neutrophils, in the APAP-injured liver is attributed to an accelerated resolution of inflammation at the onset of liver repair, possibly through enhanced phagocytic function of neutrophils in an autocrine manner.

3.
Heliyon ; 8(8): e10049, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35992006

RESUMO

Objective: Aortic diseases, mainly including aortic dilatation, aortic aneurysm (AA) and aortic dissection (AD), have high morbidity and mortality. Many studies have suggested that obstructive sleep apnea (OSA) acts as a candidate risk factor for aortic diseases. Thus, we performed a meta-analysis to explore comprehensively the effect of OSA on the risk of aortic disease occurrence. Methods: We searched PubMed, Embase and Cochrane Library databases from inception to February 2022 to identify studies investigating the association between OSA and aortic diameter dilatation, the prevalence of OSA in individuals with or without AA/AD and the incidence of AA/AD in individuals with or without OSA. The Newcastle-Ottawa Scale (NOS) and the Agency for Healthcare Research and Quality (AHRQ) were respectively used to evaluate the quality of the included cohort and cross-sectional studies. A random or fixed effect model was used to generate pooled effects according to interstudy heterogeneity. Sensitivity analyses were performed to test the robustness of the results. Results: We identified 10 observational publications with 214,127 participants in this meta-analysis. OSA was significantly associated with increased aortic diameter (WMD = 1.46, 95% CI, 1.10-1.83, p < 0.001). OSA prevalence was higher in patients with AA/AD compared to their counterparts without AA/AD (OR = 1.90, 95% CI, 1.30-2.76, p = 0.001). No significant difference in the incidence of AA/AD was observed in individuals with or without OSA (RR = 0.85, 95% CI, 0.62-1.16, p = 0.307). Sensitivity analyses did not modify these results. Conclusions: This meta-analysis suggests that OSA is associated with aortic diameter dilatation but does not affect AA/AD occurrence.

4.
Commun Biol ; 5(1): 771, 2022 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-35915318

RESUMO

A unique feature of the liver is its high regenerative capacity, which is essential to maintain liver homeostasis. However, key regulators of liver regeneration (LR) remain ill-defined. Here, we identify hepatic miR-182-5p as a key regulator of LR. Suppressing miR-182-5p, whose expression is significantly induced in the liver of mice post two-thirds partial hepatectomy (PH), abrogates PH-induced LR in mice. In contrast, liver-specific overexpression of miR-182-5p promotes LR in mice with PH. Overexpression of miR-182-5p failed to promote proliferation in hepatocytes, but stimulates proliferation when hepatocytes are cocultured with stellate cells. Mechanistically, miR-182-5p stimulates Cyp7a1-mediated cholic acid production in hepatocytes, which promotes hedgehog (Hh) ligand production in stellate cells, leading to the activation of Hh signaling in hepatocytes and consequent cell proliferation. Collectively, our study identified miR-182-5p as a critical regulator of LR and uncovers a Cyp7a1/cholic acid-dependent mechanism by which hepatocytes crosstalk to stellate cells to facilitate LR.


Assuntos
Regeneração Hepática , MicroRNAs , Animais , Ácido Cólico/metabolismo , Proteínas Hedgehog/genética , Proteínas Hedgehog/metabolismo , Hepatócitos/metabolismo , Regeneração Hepática/genética , Camundongos , MicroRNAs/genética , MicroRNAs/metabolismo
5.
J Genet Genomics ; 49(3): 208-216, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-34861413

RESUMO

Decreased functional ß-cell mass is the hallmark of diabetes, but the cause of this metabolic defect remains elusive. Here, we show that the levels of the growth factor receptor-bound protein 10 (GRB10), a negative regulator of insulin and mTORC1 signaling, are markedly induced in islets of diabetic mice and high glucose-treated insulinoma cell line INS-1 cells. ß-cell-specific knockout of Grb10 in mice increased ß-cell mass and improved ß-cell function. Grb10-deficient ß-cells exhibit enhanced mTORC1 signaling and reduced ß-cell dedifferentiation, which could be blocked by rapamycin. On the contrary, Grb10 overexpression induced ß-cell dedifferentiation in MIN6 cells. Our study identifies GRB10 as a critical regulator of ß-cell dedifferentiation and ß-cell mass, which exerts its effect by inhibiting mTORC1 signaling.


Assuntos
Diabetes Mellitus Experimental , Proteína Adaptadora GRB10 , Animais , Desdiferenciação Celular/genética , Proliferação de Células/genética , Proteína Adaptadora GRB10/genética , Proteína Adaptadora GRB10/metabolismo , Insulina/metabolismo , Camundongos
6.
World J Biol Psychiatry ; 23(3): 228-235, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-34320901

RESUMO

AIM: Patients with depression have a high prevalence of developing dyslipidemia. In this study, we aim to investigate the difference of serum lipids, including total cholesterol (TCH), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), and triglycerides (TG), between the depressed patients and healthy controls. Sex differences in lipids and their psychological correlations were also included. METHODS: The study included 56 healthy controls (males/females = 26/30) and 110 first-diagnosed drug-naïve outpatients (males/females = 35/75). A total of 42 patients (males/females = 14/28) were followed for 3 months. RESULTS: A significant difference was found in TCH and LDL-C among healthy control and patients. Interestingly, female patients with first-diagnosed, drug-naïve depression had lower atherogenic indices than male patients. After 3 months of antidepressants therapy, female patients exhibited detrimental changes in serum lipids, namely increased TG and atherogenic index. Moreover, correlation analysis showed significant correlations between changes of depression inventory (HAMD and BDI) score and serum lipids (TCH, HDL-C) in depressed patients. CONCLUSION: We found that dyslipidemia was more common in female patients with depression during therapy with antidepressants. Moreover, the altered serum lipids and atherogenic index might be a hallmark of female patients. Further investigation of sex differences in lipid metabolism of depression is warranted.


Assuntos
Depressão , Dislipidemias , Humanos , Feminino , Masculino , LDL-Colesterol , Seguimentos , Depressão/epidemiologia , Caracteres Sexuais , Lipídeos , HDL-Colesterol , Triglicerídeos , Dislipidemias/epidemiologia , Estudos de Casos e Controles , Antidepressivos/uso terapêutico
7.
JCI Insight ; 6(17)2021 09 08.
Artigo em Inglês | MEDLINE | ID: mdl-34264867

RESUMO

A dynamically regulated microenvironment, which is mediated by crosstalk between adipocytes and neighboring cells, is critical for adipose tissue homeostasis and function. However, information on key molecules and/or signaling pathways regulating the crosstalk remains limited. In this study, we identify adipocyte miRNA-182-5p (miR-182-5p) as a crucial antiobesity molecule that stimulated beige fat thermogenesis by promoting the crosstalk between adipocytes and macrophages. miR-182-5p was highly enriched in thermogenic adipocytes, and its expression was markedly stimulated by cold exposure in mice. In contrast, miR-182-5p expression was significantly reduced in adipose tissues of obese humans and mice. Knockout of miR-185-5p decreased cold-induced beige fat thermogenesis whereas overexpression of miR-185-5p increased beiging and thermogenesis in mice. Mechanistically, miR-182-5p promoted FGF21 expression and secretion in adipocytes by suppressing nuclear receptor subfamily 1 group D member 1 (Nr1d1) at 5'-UTR, which in turn stimulates acetylcholine synthesis and release in macrophages. Increased acetylcholine expression activated the nicotine acetylcholine receptor in adipocytes, which stimulated PKA signaling and consequent thermogenic gene expression. Our study reveals a key role of the miR-182-5p/FGF21/acetylcholine/acetylcholine receptor axis that mediates the crosstalk between adipocytes and macrophages to promote beige fat thermogenesis. Activation of the miR-182-5p-induced signaling pathway in adipose tissue may be an effective approach to ameliorate obesity and associated metabolic diseases.


Assuntos
Acetilcolina/genética , Adipócitos/metabolismo , Fatores de Crescimento de Fibroblastos/genética , Macrófagos/metabolismo , MicroRNAs/genética , Obesidade/genética , Termogênese/genética , Acetilcolina/biossíntese , Adipócitos/patologia , Tecido Adiposo/citologia , Tecido Adiposo/metabolismo , Animais , Modelos Animais de Doenças , Fatores de Crescimento de Fibroblastos/biossíntese , Macrófagos/patologia , Camundongos , Camundongos Knockout , MicroRNAs/biossíntese , Obesidade/metabolismo , Obesidade/patologia , Transdução de Sinais
8.
J Exp Med ; 218(2)2021 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-33104171

RESUMO

ILC2s are present in adipose tissue and play a critical role in regulating adipose thermogenesis. However, the mechanisms underlying the activation of adipose-resident ILC2s remain poorly defined. Here, we show that IL-33, a potent ILC2 activator, stimulates phosphorylation of AMPK at Thr172 via TAK1 in primary ILC2s, which provides a feedback mechanism to inhibit IL-33-induced NF-κB activation and IL-13 production. Treating ILC2s with adiponectin or an adiponectin receptor agonist (AdipoRon) activated AMPK and decreased IL-33-NF-κB signaling. AdipoRon also suppressed cold-induced thermogenic gene expression and energy expenditure in vivo. In contrast, adiponectin deficiency increased the ILC2 fraction and activation, leading to up-regulated thermogenic gene expression in adipose tissue of cold-exposed mice. ILC2 deficiency or blocking ILC2 function by neutralization of the IL-33 receptor with anti-ST2 diminished the suppressive effect of adiponectin on cold-induced adipose thermogenesis and energy expenditure. Taken together, our study reveals that adiponectin is a negative regulator of ILC2 function in adipose tissue via AMPK-mediated negative regulation of IL-33 signaling.


Assuntos
Proteínas Quinases Ativadas por AMP/imunologia , Adiponectina/imunologia , Imunidade Inata/imunologia , Interleucina-33/imunologia , Linfócitos/imunologia , Transdução de Sinais/imunologia , Tecido Adiposo/imunologia , Animais , Retroalimentação , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , NF-kappa B/imunologia , Fosforilação/imunologia , Células Th2/imunologia , Termogênese/imunologia
9.
J Mol Cell Biol ; 11(9): 781-790, 2019 09 19.
Artigo em Inglês | MEDLINE | ID: mdl-31220300

RESUMO

Increasing brown and beige fat thermogenesis have an anti-obesity effect and thus great metabolic benefits. However, the molecular mechanisms regulating brown and beige fat thermogenesis remain to be further elucidated. We recently found that fat-specific knockout of Rheb promoted beige fat thermogenesis. In the current study, we show that Rheb has distinct effects on thermogenic gene expression in brown and beige fat. Fat-specific knockout of Rheb decreased protein kinase A (PKA) activity and thermogenic gene expression in brown adipose tissue of high-fat diet-fed mice. On the other hand, overexpression of Rheb activated PKA and increased uncoupling protein 1 expression in brown adipocytes. Mechanistically, Rheb overexpression in brown adipocytes increased Notch expression, leading to disassociation of the regulatory subunit from the catalytic subunit of PKA and subsequent PKA activation. Our study demonstrates that Rheb, by selectively modulating thermogenic gene expression in brown and beige adipose tissues, plays an important role in regulating energy homeostasis.


Assuntos
Tecido Adiposo Marrom/metabolismo , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Proteína Enriquecida em Homólogo de Ras do Encéfalo/metabolismo , Receptores Notch/metabolismo , Transdução de Sinais , Termogênese , Adipócitos/metabolismo , Tecido Adiposo Branco/metabolismo , Animais , Metabolismo Energético , Regulação da Expressão Gênica , Técnicas de Silenciamento de Genes , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Camundongos , Modelos Biológicos , Obesidade/metabolismo , Proteína Enriquecida em Homólogo de Ras do Encéfalo/genética , Proteína Desacopladora 1/genética , Proteína Desacopladora 1/metabolismo
10.
J Mol Endocrinol ; 60(4): 285-297, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29555819

RESUMO

The growth factor receptor bound protein GRB10 is an imprinted gene product and a key negative regulator of the insulin, IGF1 and mTORC1 signaling pathways. GRB10 is highly expressed in mouse fetal liver but almost completely silenced in adult mice, suggesting a potential detrimental role of this protein in adult liver function. Here we show that the Grb10 gene could be reactivated in adult mouse liver by acute endoplasmic reticulum stress (ER stress) such as tunicamycin or a short-term high-fat diet (HFD) challenge, concurrently with increased unfolded protein response (UPR) and hepatosteatosis. Lipogenic gene expression and acute ER stress-induced hepatosteatosis were significantly suppressed in the liver of the liver-specific GRB10 knockout mice, uncovering a key role of Grb10 reactivation in acute ER stress-induced hepatic lipid dysregulation. Mechanically, acute ER stress induces Grb10 reactivation via an ATF4-mediated increase in Grb10 gene transcription. Our study demonstrates for the first time that the silenced Grb10 gene can be reactivated by acute ER stress and its reactivation plays an important role in the early development of hepatic steatosis.


Assuntos
Estresse do Retículo Endoplasmático , Fígado Gorduroso/metabolismo , Fígado Gorduroso/patologia , Proteína Adaptadora GRB10/metabolismo , Inativação Gênica , Fígado/metabolismo , Fígado/patologia , Fator 4 Ativador da Transcrição/metabolismo , Envelhecimento/metabolismo , Animais , Dieta Hiperlipídica , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Ácidos Graxos/biossíntese , Fígado Gorduroso/genética , Comportamento Alimentar , Proteína Adaptadora GRB10/genética , Deleção de Genes , Regulação da Expressão Gênica/efeitos dos fármacos , Inativação Gênica/efeitos dos fármacos , Metabolismo dos Lipídeos/efeitos dos fármacos , Fígado/efeitos dos fármacos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Especificidade de Órgãos/efeitos dos fármacos , Tunicamicina/farmacologia
11.
J Mol Cell Biol ; 9(5): 422-434, 2017 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-29087480

RESUMO

Type 2 immune response has been shown to facilitate cold-induced thermogenesis and browning of white fat. However, whether alternatively activated macrophages produce catecholamine and substantially promote adaptive thermogenesis in adipose tissue remains controversial. Here, we show that tyrosine hydroxylase (TyrH), a rate-limiting enzyme of catecholamine biosynthesis, was expressed and phosphorylated in adipose-resident macrophages. In addition, the plasma level of adrenaline was increased by cold stress in mice, and treatment of macrophages with adrenaline stimulated phosphorylation of Ca2+/calmodulin-dependent protein kinase II (CaMKII) and TyrH. Genetic and pharmacological inhibition of CaMKII or PKA signaling diminished adrenaline-induced phosphorylation of TyrH in primary macrophages. Consistently, overexpression of constitutively active CaMKII upregulated basal TyrH phosphorylation, while suppressing the stimulatory effect of adrenaline on TyrH in macrophages. Myeloid-specific disruption of CaMKIIγ suppressed both the cold-induced production of norepinephrine and adipose UCP1 expression in vivo and the stimulatory effect of adrenaline on macrophage-dependent activation of brown adipocytes in vitro. Lack of CaMKII signaling attenuated catecholamine production mediated by cytokines IL-4 and IL-13, key inducers of type 2 immune response in primary macrophages. Taken together, these results suggest a feedforward mechanism of adrenaline in adipose-resident macrophages, and that myeloid CaMKII signaling plays an important role in catecholamine production and subsequent beige fat activation.


Assuntos
Adrenérgicos/metabolismo , Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina/metabolismo , Catecolaminas/biossíntese , Células Mieloides/metabolismo , Transdução de Sinais , Adaptação Biológica , Adipócitos Bege/metabolismo , Animais , Temperatura Baixa , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Metabolismo Energético , Epinefrina/sangue , Macrófagos/metabolismo , Camundongos , Fosforilação , Estresse Fisiológico/genética , Termogênese , Tirosina 3-Mono-Oxigenase/metabolismo
13.
FASEB J ; 31(6): 2314-2326, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28232481

RESUMO

Hepatic insulin resistance and hepatosteatosis in diet-induced obesity are associated with various metabolic diseases, yet the underlying mechanisms remain to be fully elucidated. Here we show that the expression levels of the disulfide-bond A oxidoreductase-like protein (DsbA-L) are significantly reduced in the liver of obese mice and humans. Liver-specific knockout or adenovirus-mediated overexpression of DsbA-L exacerbates or alleviates, respectively, high-fat diet-induced mitochondrial dysfunction, hepatosteatosis, and insulin resistance in mice. Mechanistically, we found that DsbA-L is localized in mitochondria and that its deficiency is associated with impairment of maximum respiratory capacity, elevated cellular oxidative stress, and increased JNK activity. Our results identify DsbA-L as a critical regulator of mitochondrial function, and its down-regulation in the liver may contribute to obesity-induced hepatosteatosis and whole body insulin resistance.-Chen, H., Bai, J., Dong, F., Fang, H., Zhang, Y., Meng, W., Liu, B., Luo, Y., Liu, M., Bai, Y., Abdul-Ghani, M. A., Li, R., Wu, J., Zeng, R., Zhou, Z., Dong, L. Q., Liu, F. Hepatic DsbA-L protects mice from diet-induced hepatosteatosis and insulin resistance.


Assuntos
Gorduras na Dieta/efeitos adversos , Fígado Gorduroso/induzido quimicamente , Glutationa Transferase/metabolismo , Resistência à Insulina/fisiologia , Fígado/efeitos dos fármacos , Trifosfato de Adenosina/metabolismo , Animais , Dieta Hiperlipídica/efeitos adversos , Regulação Enzimológica da Expressão Gênica , Técnica Clamp de Glucose , Glutationa Transferase/genética , Hepatócitos , Humanos , Fígado/enzimologia , Masculino , Camundongos , Camundongos Knockout , Mitocôndrias Hepáticas/metabolismo , Estresse Oxidativo , Consumo de Oxigênio
15.
Biochem Biophys Res Commun ; 438(4): 575-80, 2013 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-23954633

RESUMO

microRNAs (miRNAs) have been reported to play an essential role in the regulation of brown adipocyte adipogenesis. In the present study, we investigated the role of the miR-106b-93 cluster in the differentiation of brown adipocytes. We found that knockdown of miR-106b and miR-93 significantly induced the expression of brown fat-specific genes and promoted the accumulation of lipid-droplet in differentiating brown adipocytes. In addition, ectopic expression of miR-106b and miR-93 suppressed the mRNA level of Ucp1, a selective hallmark of brown adipocytes. Furthermore, the expression levels of miR-106b and miR-93 are higher in brown adipose tissues of high fat diet-induced obese mice compared to control mice. Taken together, our results identify miR-106b and miR-93 as negative regulators of brown adipocyte differentiation and the miR-106b-93 cluster may play an important role in regulating energy homeostasis.


Assuntos
Adipócitos Marrons/citologia , Adipogenia , Regulação da Expressão Gênica no Desenvolvimento , MicroRNAs/genética , Adipócitos Marrons/metabolismo , Animais , Linhagem Celular , Dieta Hiperlipídica , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Obesos , MicroRNAs/análise , Triglicerídeos/análise , Triglicerídeos/metabolismo , Regulação para Cima
16.
Huan Jing Ke Xue ; 34(1): 8-14, 2013 Jan.
Artigo em Chinês | MEDLINE | ID: mdl-23487911

RESUMO

The possible organic acid emission sources in PM10 in Xiamen urban atmosphere such as cooking, biomass burning, vehicle exhaust and soil/dust were obtained using a re-suspension test chamber. A total of 15 organic acids including dicarboxylic acids, fatty acids and aromatic acids were determined using GC/MS after derivatization with BF3/n-butanol. The results showed that the highest total concentration of 15 organic acids (53%) was found in cooking emission and the average concentration of the sum of linoleic acid and oleic acid was 24% +/- 14%. However, oxalic acid was the most abundant species followed by phthalic acid in gasoline vehicle exhaust. The ratios of adipic to azelaic acid in gasoline combustion emissions were significantly higher than those in other emission sources, which can be used to qualitatively differentiate anthropogenic and biological source of dicarboxylic acids in atmospheric samples. The ratios of malonic to succinic acid in source emissions (except gasoline generator emissions) were lower (0.07-0.44) than ambient PM10 samples (0.61-3.93), which can be used to qualitatively differentiate the primary source and the secondary source of dicarboxylic acids in urban PM10.


Assuntos
Poluentes Atmosféricos/análise , Atmosfera/análise , Monitoramento Ambiental , Compostos Orgânicos/análise , Material Particulado/química , Ácidos/análise , China , Cidades , Ácidos Dicarboxílicos/análise , Ácidos Graxos/análise , Cromatografia Gasosa-Espectrometria de Massas , Ácido Oxálico/análise , Tamanho da Partícula
17.
Acta Diabetol ; 50(2): 163-73, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21153483

RESUMO

Since most of the current studies of thiazolidinediones (TZDs) are only focused on improving glycemic control, increasing insulin sensitivity, and regulating inflammatory states in Type 2 Diabetes, it is still controversial whether TZDs have direct, protective effects on pancreatic ß-cells in autoimmune diabetes. Here, we show the protective effects of TZDs on mouse pancreatic ß-cell line cells (NIT-1) impaired by exposure to inflammatory cytokines (IL-1ß and IFN-γ) and explore the potential mechanisms for this. The apoptosis rate and caspase-3 activity were remarkably increased, and insulin secretion response to glucose was impaired severely by exposure to IL-1ß/IFN-γ for 48 h compared to control cells, whereas apoptosis rate and caspase-3 activity were significantly decreased in cells with treatment of rosiglitazone (RGZ) or pioglitazone (PIG), and the capacity for insulin secretion response to glucose was recovered. TZDs protect pancreatic ß-cells from cytokine-induced cytotoxicity through PPARγ activation. The protective effects of the TZDs on NIT-1 cells disappeared when PPARγ was blocked with PPARγ-siRNA interference or treatment with GW9662, the PPARγ antagonist. Additionally, the enhancement of PPARγ expression by treatment with TZDs inhibited the expression of caspase 3 in IL-1ß/IFN-γ-induced NIT-cells. Also, the inhibition of caspase 3 expression by TZDs was blocked by co-treatment with GW9662 or infection with PPARγ-siRNA. Taken together, our data suggest that TZDs might serve to protect pancreatic ß-cells directly from cytokine-induced cytotoxicity through a PPARγ-dependent pathway, and caspase-3 may play an important role in the mechanisms involved.


Assuntos
Citocinas/farmacologia , Células Secretoras de Insulina/efeitos dos fármacos , Células Secretoras de Insulina/fisiologia , PPAR gama/fisiologia , Tiazolidinedionas/farmacologia , Animais , Apoptose/efeitos dos fármacos , Caspase 3/fisiologia , Inibidores de Caspase/farmacologia , Linhagem Celular , Glucose/farmacologia , Insulina/metabolismo , Secreção de Insulina , Interferon gama/farmacologia , Interleucina-1beta/farmacologia , Camundongos , Camundongos Transgênicos , PPAR gama/genética , RNA Interferente Pequeno/genética , Transfecção
18.
Zhonghua Yi Xue Za Zhi ; 92(10): 695-9, 2012 Mar 13.
Artigo em Chinês | MEDLINE | ID: mdl-22781299

RESUMO

OBJECTIVE: To explore the protective effects and potential mechanisms of 1α, 25(OH)(2) D(3) (VitD(3)) on pancreatic ß-cells. METHODS: The apoptosis of NIT-1 cells was induced by interleukin-1ß (IL-1ß) and interferon-γ (IFN-γ) in vitro. Then the apoptotic rate of NIT-1 cells was determined by Hoechest33342 staining and Annexin V-FITC/PI flow cytometry. The insulin secretion level of NIT-1 cells was measured by ELISA. The NIT-1 cells were treated with VitD(3) at the final concentrations of 10(-8) mol/L or underwent transient transfection with vitamin D receptor (VDR)-SiRNA. RESULTS: After the treatment of VitD(3), the apoptotic rate of NIT-1 cells decreased to 39.7%. There were significant differences in apoptotic rate between the VitD(3) treatment and IL-1ß/IFN-γ groups (68.4%) (P < 0.01). Similarly impaired glucose-stimulated insulin secretion (GSIS) of NIT-1 cells recovered ((7.34 ± 0.21) ng/ml) after the treatment of VitD(3) as compared with the IL-1ß/IFN-γ group ((4.88 ± 0.32) ng/ml, P < 0.01). Moreover, most of the protective effects of VitD(3) on pancreatic ß-cells could be blocked by the transfection of VDR-SiRNA. CONCLUSION: VitD(3) may protect pancreatic ß-cells from cytokine-induced apoptosis and impaired insulin secretion through its conjugation with VDR.


Assuntos
Apoptose/efeitos dos fármacos , Calcitriol/farmacologia , Células Secretoras de Insulina/efeitos dos fármacos , Insulina/metabolismo , Animais , Linhagem Celular , Secreção de Insulina , Interferon gama/farmacologia , Interleucina-1beta/farmacologia , Camundongos
19.
Huan Jing Ke Xue ; 32(9): 2794-9, 2011 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-22165253

RESUMO

During the period from August 10, 2010 through August 14, 2010, particle and gas phase PAHs were collected and analyzed using double filters plus PUFs (Poly Urethane Foam) sampling system, and the uncertainties of gas/particle partitioning coefficients of PAHs were investigated using the propagation of errors formulas. The results showed that low-molecular weight PAHs such as naphthalene, acenaphthylene, acenaphthene and fluorene possessed the strong breakthrough capacity with the breakthrough rates close to 50% in double PUF cartridges. The corrected K(p) values based on the sorption of PAHs to the primary filter were more than an order of magnitude higher than those without sorption correction for naphthalene, acenaphthylene and acenaphthene. The uncertainties for all the 19 PAHs ranged from 28.14% to 50.37% based on the standard error propagation formulas, with higher values for volatile and involatile PAHs and lower values for semi-volatile PAHs. The results also showed that the uncertainties of K(p) were mainly contributed from the measurements of particle (average variance contribution was 77.9%) and gas (average variance contribution was 22.0%) phase PAHs while the contributions of total suspended particle were ignorable. Thus, getting more accurate data for gaseous PAHs using an appropriate sampling system is the key to increase the accuracy of gas/particle partitioning coefficients of PAHs.


Assuntos
Poluentes Atmosféricos/análise , Monitoramento Ambiental , Transição de Fase , Hidrocarbonetos Policíclicos Aromáticos/análise , Atmosfera/análise , China , Cidades , Filtração , Gases/análise , Tamanho da Partícula , Incerteza
20.
Huan Jing Ke Xue ; 32(11): 3277-83, 2011 Nov.
Artigo em Chinês | MEDLINE | ID: mdl-22295624

RESUMO

The levels and congener patterns of 28 PCBs compounds were investigated in soil and dust fallout collected in a capacitor storage site and an industrial brownfield, respectively in Sichuan Ziyang Locomotive Factory. The highest concentration of the total PCBs(sigma PCBs =227 502 ng x g(-1)) was found in soil collected from the front gate (unsealed) of the capacitor storage tunnel. Very high levels of sigma PCBs, exceed 10 microg x g(-1), were also found in the dust collected from the window sill of an iron foundry. There were significant positive correlations (P < 0.01) among PCB congener concentration in the storage site and the iron foundry samples. The major contribution to the total content of PCBs in the high contaminated samples was tetrachlorinated biphenyls, followed by tri- and penta-chlorinated biphenyls. Hexa- and higher chlorinated biphenyls contributed more to sigma PCBs in the iron foundry than those in the storage site. The total toxicity equivalents (TEQ) of 12 dioxin-like congeners varied in the range of 75.43-24 027 pg x g(-1) and were much higher than those in soils of e-waste recycling sites. However, PCB126 contribute the most to the TEQ in most cases.


Assuntos
Poluentes Ambientais/análise , Bifenilos Policlorados/análise , Bifenilos Policlorados/química , Solo/análise , China , Poeira/análise , Monitoramento Ambiental , Resíduos Industriais
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA