Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 34
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Front Mol Neurosci ; 15: 1048713, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36743289

RESUMO

Formation of dendritic spine and synapse is an essential final step of brain wiring to establish functional communication in the developing brain. Recent findings have displayed altered dendritic spine and synapse morphogenesis, plasticity, and related molecular mechanisms in animal models and post-mortem human brains of autism spectrum disorders (ASD) and intellectual disability (ID). Many genes and proteins are shown to be associated with spines and synapse development, and therefore neurodevelopmental disorders. In this review, however, particular attention will be given to chromatin modifiers such as AT-Rich Interactive Domain 1B (ARID1B), KAT8 regulatory non-specific lethal (NSL) complex subunit 1 (KANSL1), and WD Repeat Domain 5 (WDR5) which are among strong susceptibility factors for ASD and ID. Emerging evidence highlights the critical status of these chromatin remodeling molecules in dendritic spine morphogenesis and synaptic functions. Molecular and cellular insights of ARID1B, KANSL1, and WDR5 will integrate into our current knowledge in understanding and interpreting the pathogenesis of ASD and ID. Modulation of their activities or levels may be an option for potential therapeutic treatment strategies for these neurodevelopmental conditions.

2.
Sci Rep ; 11(1): 3856, 2021 02 16.
Artigo em Inglês | MEDLINE | ID: mdl-33594090

RESUMO

Genetic evidence indicates that haploinsufficiency of ARID1B causes intellectual disability (ID) and autism spectrum disorder (ASD), but the neural function of ARID1B is largely unknown. Using both conditional and global Arid1b knockout mouse strains, we examined the role of ARID1B in neural progenitors. We detected an overall decrease in the proliferation of cortical and ventral neural progenitors following homozygous deletion of Arid1b, as well as altered cell cycle regulation and increased cell death. Each of these phenotypes was more pronounced in ventral neural progenitors. Furthermore, we observed decreased nuclear localization of ß-catenin in Arid1b-deficient neurons. Conditional homozygous deletion of Arid1b in ventral neural progenitors led to pronounced ID- and ASD-like behaviors in mice, whereas the deletion in cortical neural progenitors resulted in minor cognitive deficits. This study suggests an essential role for ARID1B in forebrain neurogenesis and clarifies its more pronounced role in inhibitory neural progenitors. Our findings also provide insights into the pathogenesis of ID and ASD.


Assuntos
Transtorno do Espectro Autista/etiologia , Deficiência Intelectual/etiologia , Neurogênese , Telencéfalo/embriologia , Fatores de Transcrição/fisiologia , Animais , Feminino , Masculino , Camundongos Endogâmicos C57BL , Camundongos Knockout , Células-Tronco Neurais/fisiologia , Gravidez , Telencéfalo/metabolismo , beta Catenina/metabolismo
3.
Int J Mol Sci ; 21(17)2020 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-32854424

RESUMO

Selective autolysosomal degradation of damaged mitochondria, also called mitophagy, is an indispensable process for maintaining integrity and homeostasis of mitochondria. One well-established mechanism mediating selective removal of mitochondria under relatively mild mitochondria-depolarizing stress is PINK1-Parkin-mediated or ubiquitin-dependent mitophagy. However, additional mechanisms such as LC3-mediated or ubiquitin-independent mitophagy induction by heavy environmental stress exist and remain poorly understood. The present study unravels a novel role of stress-inducible protein Sestrin2 in degradation of mitochondria damaged by transition metal stress. By utilizing proteomic methods and studies in cell culture and rodent models, we identify autophagy kinase ULK1-mediated phosphorylation sites of Sestrin2 and demonstrate Sestrin2 association with mitochondria adaptor proteins in HEK293 cells. We show that Ser-73 and Ser-254 residues of Sestrin2 are phosphorylated by ULK1, and a pool of Sestrin2 is strongly associated with mitochondrial ATP5A in response to Cu-induced oxidative stress. Subsequently, this interaction promotes association with LC3-coated autolysosomes to induce degradation of mitochondria damaged by Cu-induced ROS. Treatment of cells with antioxidants or a Cu chelator significantly reduces Sestrin2 association with mitochondria. These results highlight the ULK1-Sestrin2 pathway as a novel stress-sensing mechanism that can rapidly induce autophagic degradation of mitochondria under severe heavy metal stress.


Assuntos
Proteína Homóloga à Proteína-1 Relacionada à Autofagia/metabolismo , Cobre/farmacologia , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Mitocôndrias/fisiologia , Proteínas Nucleares/metabolismo , Proteômica/métodos , Autofagia , Sítios de Ligação , Células HEK293 , Humanos , Proteínas Associadas aos Microtúbulos/metabolismo , ATPases Mitocondriais Próton-Translocadoras/metabolismo , Mitofagia , Proteínas Nucleares/química , Estresse Oxidativo , Fosforilação , Transdução de Sinais/efeitos dos fármacos
4.
Sci Rep ; 10(1): 7834, 2020 05 12.
Artigo em Inglês | MEDLINE | ID: mdl-32398858

RESUMO

Inhibitory interneurons are essential for proper brain development and function. Dysfunction of interneurons is implicated in several neurodevelopmental disorders, including autism spectrum disorder (ASD) and intellectual disability (ID). We have previously shown that Arid1b haploinsufficiency interferes with interneuron development and leads to social, cognitive, and emotional impairments consistent with ASD and ID. It is unclear, however, whether interneurons play a major role for the behavioral deficits in Arid1b haploinsufficiency. Furthermore, it is critical to determine which interneuron subtypes contribute to distinct behavioral phenotypes. In the present study, we generated Arid1b haploinsufficient mice in which a copy of the Arid1b gene is deleted in either parvalbumin (PV) or somatostatin (SST) interneurons, and examined their ASD- and ID-like behaviors. We found that Arid1b haploinsufficiency in PV or SST interneurons resulted in distinct features that do not overlap with one another. Arid1b haploinsufficiency in PV neurons contributed to social and emotional impairments, while the gene deletion in the SST population caused stereotypies as well as learning and memory dysfunction. These findings demonstrate a critical role of interneurons in Arid1b haploinsufficient pathology and suggest that PV and SST interneurons may have distinct roles in modulating neurological phenotypes in Arid1b haploinsufficiency-induced ASD and ID.


Assuntos
Transtorno do Espectro Autista/genética , Haploinsuficiência , Deficiência Intelectual/genética , Interneurônios/metabolismo , Parvalbuminas/metabolismo , Somatostatina/metabolismo , Fatores de Transcrição/genética , Animais , Ansiedade/complicações , Transtorno do Espectro Autista/complicações , Transtorno do Espectro Autista/patologia , Transtorno do Espectro Autista/fisiopatologia , Comportamento Animal , Depressão/complicações , Regulação da Expressão Gênica , Deficiência Intelectual/complicações , Deficiência Intelectual/patologia , Deficiência Intelectual/fisiopatologia , Interneurônios/patologia , Memória , Fenótipo , Comportamento Social , Aprendizagem Espacial
5.
Artigo em Inglês | MEDLINE | ID: mdl-30149092

RESUMO

Haploinsufficiency of the chromatin remodeling factor ARID1B leads to autism spectrum disorder and intellectual disability. Several independent research groups, including our own, recently examined the effects of heterozygous deletion of Arid1b in mice and reported severe behavioral abnormalities reminiscent of autism spectrum disorders and intellectual disability as well as marked changes in gene expression and decreased body size. Arid1b heterozygous mice also display significant cortical excitatory/inhibitory imbalance due to altered GABAergic neuron numbers and impaired inhibitory synaptic transmission. Abnormal epigenetic modifications, including histone acetylation and methylation, are additionally associated with Arid1b haploinsufficiency in the brain. Treating adult Arid1b mutant mice with a positive GABA allosteric modulator, however, rescues multiple behavioral abnormalities, such as cognitive and social impairments, as well as elevated anxiety. While treating Arid1b haploinsufficient mice with recombinant mouse growth hormone successfully increases body size, it has no effect on aberrant behavior. Here we summarize the recent findings regarding the role of ARID1B in brain development and behavior and discuss the utility of the Arid1b heterozygous mouse model in neurodevelopmental and psychiatric research. We also discuss some of the opportunities and potential challenges in developing translational applications for humans and possible avenues for further research into the mechanisms of ARID1B pathology in the brain.


Assuntos
Comportamento/fisiologia , Encéfalo/crescimento & desenvolvimento , Encéfalo/metabolismo , Proteínas de Ligação a DNA/metabolismo , Fatores de Transcrição/metabolismo , Animais , Proteínas de Ligação a DNA/genética , Humanos , Transtornos Mentais/genética , Transtornos Mentais/metabolismo , Fatores de Transcrição/genética
6.
Aging (Albany NY) ; 8(11): 2667-2688, 2016 09 12.
Artigo em Inglês | MEDLINE | ID: mdl-27922816

RESUMO

Myelination, the process by which oligodendrocytes form the myelin sheath around axons, is key to axonal signal transduction and related motor function in the central nervous system (CNS). Aging is characterized by degenerative changes in the myelin sheath, although the molecular underpinnings of normal and aberrant myelination remain incompletely understood. Here we report that axon myelination and related motor function are dependent on BubR1, a mitotic checkpoint protein that has been linked to progeroid phenotypes when expressed at low levels and healthy lifespan when overabundant. We found that oligodendrocyte progenitor cell proliferation and oligodendrocyte density is markedly reduced in mutant mice with low amounts of BubR1 (BubR1H/H mice), causing axonal hypomyelination in both brain and spinal cord. Expression of essential myelin-related genes such as MBP and PLP1 was significantly reduced in these tissues. Consistent with defective myelination, BubR1H/H mice exhibited various motor deficits, including impaired motor strength, coordination, and balance, irregular gait patterns and reduced locomotor activity. Collectively, these data suggest that BubR1 is a key determinant of oligodendrocyte production and function and provide a molecular entry point to understand age-related degenerative changes in axon myelination.


Assuntos
Axônios/metabolismo , Encéfalo/metabolismo , Proteínas de Ciclo Celular/genética , Marcha/genética , Atividade Motora/genética , Bainha de Mielina/metabolismo , Proteínas Serina-Treonina Quinases/genética , Medula Espinal/metabolismo , Animais , Encéfalo/citologia , Proteínas de Ciclo Celular/metabolismo , Proliferação de Células/genética , Camundongos , Camundongos Knockout , Oligodendroglia/citologia , Oligodendroglia/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo
7.
Sci Rep ; 6: 30111, 2016 07 21.
Artigo em Inglês | MEDLINE | ID: mdl-27439777

RESUMO

Non-alcoholic fatty liver disease (NAFLD) is one of the most frequent causes of liver disease and its prevalence is a serious and growing clinical problem. Caloric restriction (CR) is commonly recommended for improvement of obesity-related diseases such as NAFLD. However, the effects of CR on hepatic metabolism remain unknown. We investigated the effects of CR on metabolic dysfunction in the liver of obese diabetic db/db mice. We found that CR of db/db mice reverted insulin resistance, hepatic steatosis, body weight and adiposity to those of db/m mice. (1)H-NMR- and UPLC-QTOF-MS-based metabolite profiling data showed significant metabolic alterations related to lipogenesis, ketogenesis, and inflammation in db/db mice. Moreover, western blot analysis showed that lipogenesis pathway enzymes in the liver of db/db mice were reduced by CR. In addition, CR reversed ketogenesis pathway enzymes and the enhanced autophagy, mitochondrial biogenesis, collagen deposition and endoplasmic reticulum stress in db/db mice. In particular, hepatic inflammation-related proteins including lipocalin-2 in db/db mice were attenuated by CR. Hepatic metabolomic studies yielded multiple pathological mechanisms of NAFLD. Also, these findings showed that CR has a therapeutic effect by attenuating the deleterious effects of obesity and diabetes-induced multiple complications.


Assuntos
Peso Corporal , Restrição Calórica , Fígado/metabolismo , Hepatopatia Gordurosa não Alcoólica/dietoterapia , Animais , Cromatografia Líquida , Colágeno/metabolismo , Estresse do Retículo Endoplasmático , Cetonas/metabolismo , Metabolismo dos Lipídeos , Lipogênese , Espectrometria de Massas , Metabolômica , Camundongos , Hepatopatia Gordurosa não Alcoólica/metabolismo , Espectroscopia de Prótons por Ressonância Magnética , Triglicerídeos/biossíntese
8.
Neurobiol Aging ; 44: 127-137, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27318140

RESUMO

Diabetes may adversely affect cognitive function and, conversely, caloric restriction (CR) increases longevity and improves memory. To shed light on the unknown underlying mechanisms involved in these observations, we examined the effects of CR on serum metabolic parameters and hippocampal protein expression in the ob/ob mice model of obesity-induced diabetes. We found that CR reduced hepatic steatosis and insulin resistance in ob/ob mice. In addition, CR increased the levels of hippocampal O-linked-N-acetylglucosamine (O-GlcNAc) and GlcNAc transferase and decreased the expression of calcium/calmodulin-dependent protein kinase II, lipocalin-2, and phosphorylated tau. Furthermore, CR lessened the learning deficits that are typically seen in ob/ob mice. These findings indicate that CR may reverse obesity-related brain glucose impairment and intracellular Ca(2+) dysfunction and relieve learning impairment associated with diabetes.


Assuntos
Acetilglucosamina/metabolismo , Sinalização do Cálcio/fisiologia , Restrição Calórica , Hipocampo/metabolismo , Hipocampo/fisiopatologia , Deficiências da Aprendizagem/etiologia , Aprendizagem , Animais , Quinase da Proteína Quinase Dependente de Cálcio-Calmodulina/metabolismo , Complicações do Diabetes/complicações , Fígado Gorduroso/prevenção & controle , Resistência à Insulina , Masculino , Camundongos Endogâmicos C57BL , Camundongos Obesos , N-Acetilglucosaminiltransferases/metabolismo , Fosforilação , Proteínas tau/metabolismo
9.
J Cereb Blood Flow Metab ; 36(6): 1098-110, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-26661177

RESUMO

Diabetes-induced cognitive decline has been recognized in human patients of type 2 diabetes mellitus and mouse model of obesity, but the underlying mechanisms or therapeutic targets are not clearly identified. We investigated the effect of caloric restriction on diabetes-induced memory deficits and searched a molecular mechanism of caloric restriction-mediated neuroprotection. C57BL/6 mice were fed a high-fat diet for 40 weeks and RNA-seq analysis was performed in the hippocampus of high-fat diet-fed mice. To investigate caloric restriction effect on differential expression of genes, mice were fed high-fat diet for 20 weeks and continued on high-fat diet or subjected to caloric restriction (2 g/day) for 12 weeks. High-fat diet-fed mice exhibited insulin resistance, glial activation, blood-brain barrier leakage, and memory deficits, in that we identified neurogranin, a down-regulated gene in high-fat diet-fed mice using RNA-seq analysis; neurogranin regulates Ca(2+)/calmodulin-dependent synaptic function. Caloric restriction increased insulin sensitivity, reduced high-fat diet-induced blood-brain barrier leakage and glial activation, and improved memory deficit. Furthermore, caloric restriction reversed high-fat diet-induced expression of neurogranin and the activation of Ca(2+)/calmodulin-dependent protein kinase II and calpain as well as the downstream effectors. Our results suggest that neurogranin is an important factor of high-fat diet-induced memory deficits on which caloric restriction has a therapeutic effect by regulating neurogranin-associated calcium signaling.


Assuntos
Sinalização do Cálcio , Restrição Calórica , Transtornos Cognitivos/dietoterapia , Diabetes Mellitus Tipo 2/complicações , Neurogranina/genética , Animais , Transtornos Cognitivos/etiologia , Dieta Hiperlipídica , Perfilação da Expressão Gênica , Hipocampo/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Análise de Sequência de RNA
10.
Korean J Physiol Pharmacol ; 18(4): 333-9, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25177166

RESUMO

Exendin-4 (Ex-4), a glucagon-like peptide-1 receptor (GLP-1R) agonist, has been known to reverse hepatic steatosis in ob/ob mice. Although many studies have evaluated molecular targets of Ex-4, its mechanism of action on hepatic steatosis and fibrosis has not fully been determined. In the liver, glucose transporter 4 (GLUT4) is mainly expressed in hepatocytes, endothelial cells and hepatic stellate cells (HSCs). In the present study, the effects of Ex-4 on GLUT4 expression were determined in the liver of ob/ob mice. Ob/ob mice were treated with Ex-4 for 10 weeks. Serum metabolic parameters, hepatic triglyceride levels, and liver tissues were evaluated for hepatic steatosis. The weights of the whole body and liver in ob/ob mice were reduced by long-term Ex-4 treatment. Serum metabolic parameters, hepatic steatosis, and hepatic fibrosis in ob/ob mice were reduced by Ex-4. Particularly, Ex-4 improved hepatic steatosis by enhancing GLUT4 via GLP-1R activation in ob/ob mice. Ex-4 treatment also inhibited hepatic fibrosis by decreasing expression of connective tissue growth factor in HSCs of ob/ob mice. Our data suggest that GLP-1 agonists exert a protective effect on hepatic steatosis and fibrosis in obesity and type 2 diabetes.

11.
Biosci Biotechnol Biochem ; 78(3): 482-9, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25036839

RESUMO

A Vigna nakashimae (VN) extract has been shown to have antidiabetic and anti-obesity effects. However, the mechanism underlying the effect of a VN extract on hepatic inflammation and endoplasmic reticulum (ER) stress remains unclear. In the present study, we investigated how a VN extract protects against the development of non-alcoholic fatty liver disease (NAFLD). A VN extract for 12 weeks reduced the body weight, serum metabolic parameters, cytokines, and hepatic steatosis in high-fat diet (HFD)-fed mice. A VN extract decreased HFD-induced hepatic acetyl CoA carboxylase and glucose transporter 4 expressions. In addition to the levels of high-mobility group box 1 and receptor for advanced glycation, the hepatic expression of ATF4 and caspase-3 was also reduced by a VN extract. Thus, these data indicate that a chronic VN extract prevented NAFLD through multiple mechanisms, including inflammation, ER stress, and apoptosis in the liver.


Assuntos
Fabaceae/química , Inflamação/tratamento farmacológico , Hepatopatia Gordurosa não Alcoólica/tratamento farmacológico , Extratos Vegetais/administração & dosagem , Acetil-CoA Carboxilase/biossíntese , Animais , Apoptose/efeitos dos fármacos , Dieta Hiperlipídica , Regulação da Expressão Gênica/efeitos dos fármacos , Transportador de Glucose Tipo 4/biossíntese , Humanos , Inflamação/metabolismo , Inflamação/patologia , Metabolismo dos Lipídeos/efeitos dos fármacos , Camundongos , Hepatopatia Gordurosa não Alcoólica/metabolismo , Hepatopatia Gordurosa não Alcoólica/patologia , Extratos Vegetais/química
12.
Metab Brain Dis ; 29(3): 635-43, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24756314

RESUMO

Obesity-induced fatty liver disease is associated with increased hypothalamic inflammation. Previous reports have demonstrated that the deletion of SIRT1 in hepatocytes increases hepatic steatosis and inflammation. Using myeloid cell-specific SIRT1 knockout (KO) mice, we investigated whether ablation of SIRT1 in macrophages plays a role in regulating hepatic steatosis and hypothalamic inflammation. When challenged with a high-fat diet (HFD) for 24 weeks, hyperleptinemia, hyperinsulinemia, hepatic steatosis and macrophage infiltrations in HFD-fed KO mice were increased compared with HFD-fed WT mice. Hypothalamic expression levels of iba1 were increased in HFD-fed KO mice compared with HFD-fed WT mice. In particular, the expression levels of choline acetyltransferase were decreased in the hypothalamus of HFD-fed KO mice compared with HFD-fed WT mice. Thus, our findings suggest that SIRT1 plays a key role for hepatic steatosis and hypothalamic inflammation and that anti-inflammatory effect of SIRT1 may be important for the prevention of obesity-induced metabolic syndromes.


Assuntos
Fígado Gorduroso/metabolismo , Hipotálamo/metabolismo , Inflamação/metabolismo , Células Mieloides/metabolismo , Sirtuína 1/metabolismo , Animais , Dieta Hiperlipídica , Fígado Gorduroso/genética , Fígado Gorduroso/patologia , Teste de Tolerância a Glucose , Hipotálamo/patologia , Inflamação/genética , Inflamação/patologia , Insulina/sangue , Resistência à Insulina/genética , Leptina/sangue , Masculino , Camundongos , Camundongos Knockout , Células Mieloides/patologia , Sirtuína 1/genética
13.
Epilepsy Res ; 108(3): 367-78, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24518891

RESUMO

Status epilepticus (SE) leads to neurodegeneration which likely contributes to the development of chronic temporal lobe epilepsy (TLE). Therefore, neuroprotection following SE is considered as a promising strategy for preventing chronic TLE, but molecular changes that occur following SE still remain unclear. The Forkhead homeobox type O (FoxO) family of Forkhead transcription factors mediates cell death in several pathological conditions, but the role of FoxO in the excitotoxic effects of kainic acid (KA) remains largely unknown. The present study examined how FoxO3a and its interaction with other proteins changed in response to excitotoxic stimuli in the mouse hippocampus after SE. Mice were given intraperitoneal injection of kainate and seizure behavior was monitored for 2h to ensure SE. Western blot analyses, co-immunoprecipitation experiments, sub-cellular fractionation and double immunofluorescence analyses were used to determine changes in levels of FoxO3a, Akt, Bim, cleaved caspase-3 and phospho-FoxO3a or phospho-Akt, and their interactions at 6 or 24h after KA treatment. We found that SE activated FoxO3a and increased levels of Bim or cleaved caspase-3, and decreased levels of phospho-FoxO3a or phospho-Akt in the hippocampus. In addition, we noted extensive hippocampal cell death at 24h after KA treatment, evidenced by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling (TUNEL), fluoro-jade B or anti-active caspase-3 staining. Furthermore, co-immunoprecipitation experiments revealed that phospho-Akt interaction with FoxO3a was significantly lowered in the hippocampus at 24h after KA treatment, paralleling enhanced Bim levels and Bim interaction with Bcl-xL. Moreover, double immunofluorescence analyses showed increased co-localization of FoxO3a or Bim and TUNEL in the hippocampi at 24h after KA treatment. Identifying molecular mechanism underlying SE-induced neuronal death can provide a novel strategy to protect against seizure-induced neuronal injury. We found that Akt-FoxO3a signaling relates to seizure-induced neuronal death, providing insight into neuroprotection following SE.


Assuntos
Fator 3-gama Nuclear de Hepatócito/metabolismo , Neurônios/patologia , Proteína Oncogênica v-akt/metabolismo , Convulsões/patologia , Animais , Proteínas Reguladoras de Apoptose/metabolismo , Proteína 11 Semelhante a Bcl-2 , Caspase 3/metabolismo , Morte Celular/efeitos dos fármacos , Modelos Animais de Doenças , Agonistas de Aminoácidos Excitatórios/toxicidade , Regulação da Expressão Gênica/efeitos dos fármacos , Regulação da Expressão Gênica/fisiologia , Hipocampo/efeitos dos fármacos , Hipocampo/patologia , Ácido Caínico/toxicidade , Masculino , Proteínas de Membrana/metabolismo , Camundongos , Camundongos Endogâmicos ICR , Neurônios/ultraestrutura , Fosfopiruvato Hidratase/metabolismo , Fosforilação/efeitos dos fármacos , Proteínas Proto-Oncogênicas/metabolismo , Convulsões/induzido quimicamente , Frações Subcelulares/efeitos dos fármacos , Frações Subcelulares/metabolismo , Fatores de Tempo
14.
Mol Cell Endocrinol ; 382(1): 178-189, 2014 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-24096089

RESUMO

Several association studies have implicated the PARK2 gene that encodes parkin--the key molecule orchestrating the mitochondrial quality control system--as a candidate susceptibility gene for diabetes. A total of 7551 unrelated Korean KARE cohort subjects were analyzed to investigate the association between the PARK2 single nucleotide polymorphism (SNP) and quantitative glycemic traits. Two SNPs, rs10455889 and rs9365294, were significantly associated with fasting plasma glucose level (p=∼1.2×10(-4)) and insulin secretion indices (p=∼7.4×10(-5)) in male KARE subjects. Parkin was expressed predominantly in the rat pancreatic islets. Downregulation of the Park2 gene in rat INS-1 ß-cells resulted in a significant decrease in the glucose-stimulated insulin secretion, intracellular insulin gene expression, and intracellular ATP level. The Park2-depleted ß-cells also exhibited increased mitochondrial fragmentation and ROS production and decreased mitochondrial membrane potential. Both population-based statistical evaluation and experimental evidence demonstrated a fundamental role of the PARK2 gene in the maintenance of ß-cell function.


Assuntos
Células Secretoras de Insulina/metabolismo , Insulina/biossíntese , Insulina/metabolismo , Ubiquitina-Proteína Ligases/genética , Trifosfato de Adenosina/metabolismo , Adulto , Idoso , Animais , Estudos de Coortes , Perfilação da Expressão Gênica , Técnicas de Silenciamento de Genes , Humanos , Secreção de Insulina , Masculino , Pessoa de Meia-Idade , Mitocôndrias/metabolismo , Polimorfismo de Nucleotídeo Único/genética , Característica Quantitativa Herdável , Ratos , Ubiquitina-Proteína Ligases/metabolismo
15.
Korean J Physiol Pharmacol ; 17(4): 267-74, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23946685

RESUMO

A beneficial radioprotective agent has been used to treat the radiation-induced lung injury. This study was performed to investigate whether curcumin, which is known to have anti-inflammatory and antioxidant properties, could ameliorate radiation-induced pulmonary inflammation and fibrosis in irradiated lungs. Rats were given daily doses of intragastric curcumin (200 mg/kg) prior to a single irradiation and for 8 weeks after radiation. Histopathologic findings demonstrated that macrophage accumulation, interstitial edema, alveolar septal thickness, perivascular fibrosis, and collapse in radiation-treated lungs were inhibited by curcumin administration. Radiation-induced transforming growth factor-ß1 (TGF-ß1), connective tissue growth factor (CTGF) expression, and collagen accumulation were also inhibited by curcumin. Moreover, western blot analysis revealed that curcumin lowered radiation-induced increases of tumor necrosis factor-α (TNF-α), TNF receptor 1 (TNFR1), and cyclooxygenase-2 (COX-2). Curcumin also inhibited the nuclear translocation of nuclear factor-κ B (NF-κB) p65 in radiation-treated lungs. These results indicate that long-term curcumin administration may reduce lung inflammation and fibrosis caused by radiation treatment.

16.
Neurotox Res ; 23(3): 238-48, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22810835

RESUMO

Rho-associated coil kinase (ROCK) inhibitors reportedly prevent neurodegeneration, and abnormal ROCK activation in the central nervous system induces neurite collapse and retraction. However, it is unclear whether the ROCK inhibitor Y-27632 directly protects hippocampal neurons from excitotoxicity. Here, we determined the effects of Y-27632 on neuroprotection following kainic acid (KA)-induced seizures in mice and during glutamate-induced excitotoxicity in HT22 cells. One day after Y-27632 injection, mice were treated with KA and killed 1-2 days later. Fluoro-Jade B and rapid Golgi staining showed that Y-27632 protected against KA-induced neurodegeneration and neurite dystrophy. Y-27632 inhibited increases in hippocampal RhoA and ROCK2 in KA-treated mice as determined by western blot analysis. Immunohistochemical analysis revealed ROCK2-positive neurons and astrocytes in the KA-treated hippocampus. In HT22 cells, Y-27632 also protected neurons and neurite formation during glutamate-induced excitotoxicity in vitro. These results indicate that ROCK inhibition modulates neurite growth and protects neurons from excitotoxicity-induced cell death.


Assuntos
Amidas/uso terapêutico , Anticonvulsivantes/uso terapêutico , Hipocampo/efeitos dos fármacos , Proteínas do Tecido Nervoso/antagonistas & inibidores , Neurônios/efeitos dos fármacos , Neurotoxinas/toxicidade , Inibidores de Proteínas Quinases/uso terapêutico , Piridinas/uso terapêutico , Convulsões/prevenção & controle , Quinases Associadas a rho/antagonistas & inibidores , Amidas/farmacologia , Animais , Anticonvulsivantes/farmacologia , Astrócitos/efeitos dos fármacos , Astrócitos/enzimologia , Morte Celular , Células Cultivadas/efeitos dos fármacos , Convulsivantes/antagonistas & inibidores , Convulsivantes/toxicidade , Proteína Glial Fibrilar Ácida , Ácido Glutâmico/toxicidade , Hipocampo/citologia , Hipocampo/enzimologia , Hipocampo/patologia , Ácido Caínico/toxicidade , Masculino , Camundongos , Camundongos Endogâmicos ICR , Cadeias Leves de Miosina/biossíntese , Cadeias Leves de Miosina/genética , Proteínas do Tecido Nervoso/biossíntese , Proteínas do Tecido Nervoso/genética , Neuritos/efeitos dos fármacos , Neurônios/enzimologia , Neurônios/ultraestrutura , Inibidores de Proteínas Quinases/farmacologia , Piridinas/farmacologia , Convulsões/induzido quimicamente , Método Simples-Cego , Proteínas rho de Ligação ao GTP/biossíntese , Proteínas rho de Ligação ao GTP/genética , Proteína rhoA de Ligação ao GTP
17.
Cardiovasc Diabetol ; 11: 111, 2012 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-22992429

RESUMO

BACKGROUND: Hyperglycemia leads to cardiac oxidative stress and an imbalance in glucose homeostasis. Diabetic cardiomyopathy is characterised by cardiac hypertrophy and fibrosis. However, the underlying mechanisms of diabetic cardiomyopathy are not fully understood. This study aimed to investigate the effects of alpha-lipoic acid (ALA) on cardiac energy metabolism, antioxidant effect, and fibrosis in the hearts of Otsuka Long-Evans Tokushima fatty (OLETF) rats. METHODS: Animals were separated into non-diabetic Long-Evans Tokushima Otsuka (LETO) rats and diabetes-prone OLETF rats with or without ALA (200 mg/kg/day) administration for 16 weeks. Diabetic cardiomyopathy was assessed by staining with Sirius Red. The effect of ALA on AMPK signalling, antioxidant enzymes, and fibrosis-related genes in the heart of OLETF rats were performed by Western blot analysis or immunohistochemistry. RESULTS: Western blot analysis showed that cardiac adenosine monophosphate-activated kinase (AMPK) signalling was lower in OLETF rats than in LETO rats, and that ALA treatment increased the signalling in OLETF rats. Furthermore, the low antioxidant activity in OLETF rats was increased by ALA treatment. In addition to increased Sirius red staining of collagen deposits, transforming growth factor-ß1 (TGF-ß1) and connective tissue growth factor (CTGF) were expressed at higher levels in OLETF rat hearts than in LETO rat hearts, and the levels of these factors were decreased by ALA. CONCLUSIONS: ALA enhances AMPK signalling, antioxidant, and antifibrogenic effect. Theses findings suggest that ALA may have beneficial effects in the treatment of diabetic cardiomyopathy.


Assuntos
Diabetes Mellitus Tipo 2/tratamento farmacológico , Cardiomiopatias Diabéticas/tratamento farmacológico , Ácido Tióctico/farmacologia , Proteínas Quinases Ativadas por AMP/metabolismo , Animais , Antioxidantes/metabolismo , Antioxidantes/farmacologia , Diabetes Mellitus Tipo 2/metabolismo , Cardiomiopatias Diabéticas/metabolismo , Cardiomiopatias Diabéticas/patologia , Metabolismo Energético/efeitos dos fármacos , Fibrose , Masculino , Ratos , Ratos Endogâmicos OLETF , Ratos Long-Evans , Transdução de Sinais/efeitos dos fármacos
18.
Liver Int ; 32(10): 1565-73, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22863080

RESUMO

BACKGROUND: Insulin resistance, oxidative stress, inflammation and innate immune system activation contribute to the development of non-alcoholic fatty liver disease (NAFLD) through steatosis and inflammation in the liver. The powerful antioxidant α-lipoic acid (ALA) has been shown to improve insulin sensitivity and suppress inflammatory responses. This study explores how ALA administration protects against NAFLD. METHODS: Otsuka Long-Evans Tokushima Fatty (OLETF) rats were divided into two groups (treated with 200 mg/kg/day of ALA or untreated) at 12 weeks of age and sacrificed at 28 weeks of age. RESULTS: Serum levels of insulin, free fatty acids, total cholesterol, triglyceride, leptin, IL-6 and blood glucose were decreased in ALA-treated rats. Serum adiponectin levels were higher in ALA-treated rats. ALA treatment decreased the expression of sterol regulatory element binding protein-1 and acetyl CoA carboxylase, and increased glucose transporter-4 expression in the livers of OLETF rats. Expression of the antioxidant enzymes heme oxygenase-1 and Cu/Zn-superoxide dismutase was increased in the livers of ALA-treated rats. The lipid peroxidation marker 4-hydroxynonenal was decreased in the liver of ALA-treated rats. Proteins associated with innate immune activation (Toll-like receptor-4 and high-mobility group protein box-1) and inflammatory markers (vascular cell adhesion molecule-1, intercellular adhesion molecule-1, and cyclooxygenase-2) were decreased in the livers of ALA-treated rats. CONCLUSIONS: Chronic ALA supplementation prevents NAFLD through multiple mechanisms by reducing steatosis, oxidative stress, immune activation and inflammation in the liver.


Assuntos
Fígado Gorduroso/prevenção & controle , Regulação da Expressão Gênica/efeitos dos fármacos , Imunidade Inata/efeitos dos fármacos , Fígado/metabolismo , Ácido Tióctico/farmacologia , Acetil-CoA Carboxilase/metabolismo , Adiponectina/sangue , Aldeídos/metabolismo , Animais , Compostos Azo , Glicemia/metabolismo , Western Blotting , Colesterol/sangue , Ciclo-Oxigenase 2/metabolismo , Ácidos Graxos/sangue , Imunofluorescência , Transportador de Glucose Tipo 4/metabolismo , Imuno-Histoquímica , Insulina/sangue , Molécula 1 de Adesão Intercelular/metabolismo , Interleucina-6/sangue , Leptina/sangue , Peroxidação de Lipídeos/efeitos dos fármacos , Hepatopatia Gordurosa não Alcoólica , Ratos , Ratos Endogâmicos OLETF , Proteína de Ligação a Elemento Regulador de Esterol 1/metabolismo , Ácido Tióctico/uso terapêutico , Receptor 4 Toll-Like/imunologia , Receptor 4 Toll-Like/metabolismo , Triglicerídeos/sangue , Molécula 1 de Adesão de Célula Vascular/metabolismo
19.
J Sex Med ; 9(10): 2544-51, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22906304

RESUMO

INTRODUCTION: Herbal preparations have long been used as folk remedies for erectile dysfunction (ED). AIM: This study examined the effects of Tribulus terrestris and Cornus officinalis extracts on relaxation of the smooth muscle of the corpus cavernosum (CC), their mechanisms of action, and the effects of oral administration of a mixture of the herbal extracts on penile erection. METHODS: The relaxation effects and the mechanisms of action of T. terrestris extract, C. officinalis extract, and the mixture of both extracts on the rabbit CC were investigated in an organ bath. To evaluate whether the relaxation response of the CC shown in an organ bath occurs in vivo, intracavernous pressure (ICP) was calculated in rats after oral administration for a month. Additionally, adenosine 3',5'-cyclic monophosphate (cAMP) and guanosine 3', 5'-cyclic monophosphate (cGMP) in the CC were measured using immunoassay. MAIN OUTCOME MEASURES: Smooth muscle relaxation was expressed as the percent decrease in precontraction induced by phenylephrine. ICP was assessed in rats after the oral administration of a mixture of both extracts for 1 month and changes in cGMP and cAMP concentrations were measured based on the concentration of the mixture of both extracts. RESULTS: T. terrestris extract, C. officinalis extract, and the mixture of both extracts showed concentration-dependent relaxation effects of the CC. In both the endothelium-removed group and N(G)-nitro-L-arginine methyl ester pretreatment group, T. terrestris extract inhibited relaxation. ICP measured after oral administration of the extract mixture for a month was higher than that measured in the control group, and a significant increase in cAMP was observed in the mixture group. CONCLUSIONS: T. terrestris extract and C. officinalis extract exhibited concentration-dependent relaxation in an organ bath. In the in vivo study of the extract mixture, ICP and cAMP was significantly potentiated. Accordingly, the mixture of T. terrestris extract and C. officinalis extract may improve erectile function.


Assuntos
Cornus/efeitos dos fármacos , Disfunção Erétil/tratamento farmacológico , Relaxamento Muscular/efeitos dos fármacos , Músculo Liso/efeitos dos fármacos , Ereção Peniana/efeitos dos fármacos , Extratos Vegetais/farmacologia , Tribulus/efeitos dos fármacos , Animais , Masculino , Relaxamento Muscular/fisiologia , Músculo Liso/fisiologia , Ereção Peniana/fisiologia , Extratos Vegetais/administração & dosagem , Coelhos , Ratos
20.
Korean J Physiol Pharmacol ; 16(3): 159-65, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22802696

RESUMO

Squamous cell carcinoma (SCC) and adenocarcinoma (AC) are the major histological types of non-small cell lung carcinoma (NSCLC). Although both SCCs and ACs have been characterized histologically and clinically, the precise mechanisms underlying their migration and invasion are not yet known. Here, we address the involvement in NSCLC of the p21-associated kinase1 (Pak1)/LIM kinase1 (LIMK1)/cofilin pathway, which recently has been reported to play a critical role in tumor migration and invasion. The Pak1/LIMK1/cofilin pathway was evaluated in tumors from SCC (n=35) and AC (n=35) patients and in SCC- and AC-type cell lines by western blotting, immunohistochemistry, and in vitro migration and invasion assays. The levels of phosphorylated Pak1, LIMK1, and cofilin in lung tumor tissues from SCC patients were increased as compared to normal tissues. In addition, immunohistochemistry showed greater expression of phosphorylated cofilin in SCC tissues. Expression of phosphorylated Pak1 and LIMK1 proteins was also significantly higher in SCC-type cells than in AC-type cells. Moreover, migration and invasion assays revealed that a higher percentage of SCC type cells exhibited migration and invasion compared to AC type cells. Migration was also decreased in LIMK1 knockdown SK-MES-1 cells. These findings suggest that the activation of the Pak1/LIMK1/cofilin pathway could preferentially contribute to greater tumor migration and invasion in SCC, relative to that in AC.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...