RESUMO
BACKGROUND: Vascular disease in diabetes, for example, stroke, presents a significant public health burden. Recently, the dipeptidyl peptidase 4 (DPP-4) inhibitor linagliptin has been found to counteract stroke among diabetic patients, showing great promise in drug repurposing and indication expansion. However, the molecular basis of this protection mechanism remains unknown. METHODS: The expression and localization of DPP-4 in rat brain microvascular endothelial cells (rBMVECs) were assessed with immunofluorescent staining and Western blotting. The effects of DPP-4 inhibitors on cell proliferation and migration of rBMVECs were determined using MTT and transwell assays, separately. The influence of DPP-4 inhibition on the expression of molecular markers (eg, VEGF, eNOS, HIF-1α. SIRT1) was examined at both mRNA and protein levels with qRT-PCR and Western blotting, individually. RESULTS: DPP-4 inhibitors (40 nmol/L linagliptin, 30 µmol/L berberine) offer protection from hypoxia/high glucose induced impairments in the proliferation and migration of rBMVECs. Treatment with DPP-4 inhibitors counteracted the attenuating effects of hypoxic/high-glucose conditions on the expression of VEGF, eNOS, HIF-1α, and SIRT1, which can be completely eliminated by the inhibition of SIRT1 with 1 mmol/L nicotinamide. CONCLUSIONS: The protection of rBMVECs from hypoxia/high-glucose induced impairment by DPP-4 inhibitors may be mediated by the SIRT1/HIF-1α/VEGF pathway.
Assuntos
Encéfalo/efeitos dos fármacos , Hipóxia Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Inibidores da Dipeptidil Peptidase IV/farmacologia , Células Endoteliais/efeitos dos fármacos , Glucose/metabolismo , Animais , Encéfalo/irrigação sanguínea , Encéfalo/metabolismo , Hipóxia Celular/fisiologia , Linhagem Celular , Movimento Celular/efeitos dos fármacos , Movimento Celular/fisiologia , Proliferação de Células/fisiologia , Células Endoteliais/metabolismo , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Microvasos/efeitos dos fármacos , Microvasos/metabolismo , Fármacos Neuroprotetores/farmacologia , Óxido Nítrico Sintase Tipo III/metabolismo , Ratos , Transdução de Sinais , Sirtuína 1/metabolismo , Fator A de Crescimento do Endotélio Vascular/metabolismoRESUMO
AIMS: With developments of etiology of cerebral small vessel disease (CSVD) and genome-wide association study (GWAS) of stroke, the genetic studies of CSVD are focused on genes related to blood-brain barrier (BBB) and aging. The project aims to investigate the association between CSVD and susceptibility loci and candidate genes. METHODS: All study subjects admitted Beijing Tiantan Hospital from June 2009 to September 2010 including 197 cerebral small vessel disease patients(S), 198 large artery atherosclerosis control individuals (vascular stenotic rate ≥50% diameter reduction) (L), 200 hypertensive intracerebral hemorrhage control individuals (H) and 197 stroke-free control individuals (C). 15 SNPs in 4 genes (MYLK, AQP4, NINJ2, and INK4/ARF) were genotyped using Multiplex Snapshot assay. Each SNP was first examined between the groups S and C in different genetic models (codominant, dominant, recessive, overdominant, and log-additive). Permutation correction was used to adjust for multiple testing. The significant SNP loci were further analyzed in comparing S with L and H, respectively. Subgroup analysis was also performed for each risk-factor category. RESULTS: Among the 15 SNPs, rs2222823 and rs2811712 were found to be significantly associated with CSVD after multiple-testing adjustment. The heterozygote (A/T) of rs2222823 of MYLK has an odds ratio of 0.52 (95% CI =[0.35, 0.79], P= 0.002, adjusted P= 0.031) when compared with homozygotes. The heterozygote (C/T) of rs2811712 of INK4/ARF has an odds ratio of 1.75 (95% CI =[1.13-2.71], P= 0.004, adjusted P= 0.050). The SNP rs2222823 was significant (P= 0.035) in comparing S with H. In comparing S versus L, it is significant for the subgroups of patients without diabetes (P= 0.012) and drinking (P= 0.018). rs2811712 was significant in comparing S with L for the subgroups of patients with hyperlipidemia (P= 0.029) and drinking (P= 0.04). CONCLUSION: The heterozygotes (T/A) at the rs2222823 SNP locus of MYLK gene decreases the risk of having cerebral small vessel disease, while the heterozygotes (C/T) at the rs2811712 SNP locus of INK4/ARF gene increases the risk, suggesting that the MYLK and INK4/ARF are the associated genes of cerebral small vessel disease in Han Chinese population.
Assuntos
Povo Asiático/genética , Doenças de Pequenos Vasos Cerebrais/genética , Triagem de Portadores Genéticos , Estudo de Associação Genômica Ampla , Genótipo , Polimorfismo de Nucleotídeo Único/genética , Adulto , Idoso , Doenças de Pequenos Vasos Cerebrais/diagnóstico , Feminino , Estudo de Associação Genômica Ampla/métodos , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
Infantile spasms (IS) is a devastating epilepsy syndrome treated with adrenocorticotropic hormone (ACTH). To demonstrate the effects of adrenal dysfunction, adrenalectomy (ADX) and N-methyl-d-aspartate (NMDA)-induced rat model studies of IS were performed. The latency of the seizure in the ADX group decreased and the severity of seizures increased significantly. Hippocampal corticotropin-releasing hormone (CRH) mRNA was overexpressed in ADX rats. After ACTH administration, the latency increased and the severity of seizures decreased significantly. ADX increased seizure susceptibility of the rats to NMDA. Pretreatment with a single high dose of ACTH caused an obvious reduction in susceptibility to NMDA-induced seizures and suppressed CRH mRNA expression. These findings are especially useful for IS patients with adrenal diseases and worthy of further clinical study.
Assuntos
Doenças das Glândulas Suprarrenais/metabolismo , Doenças das Glândulas Suprarrenais/fisiopatologia , Hormônio Adrenocorticotrópico/administração & dosagem , N-Metilaspartato/toxicidade , Convulsões/metabolismo , Espasmo/metabolismo , Doenças das Glândulas Suprarrenais/tratamento farmacológico , Adrenalectomia , Fatores Etários , Animais , Animais Recém-Nascidos , Ratos , Ratos Wistar , Convulsões/induzido quimicamente , Convulsões/prevenção & controle , Espasmo/induzido quimicamente , Espasmo/prevenção & controleRESUMO
OBJECTIVE: The aim of this study was to perform perfusion CT imaging in the acute phase of myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS), to assess whether these patients had cerebral perfusion abnormalities. Furthermore, the pathology of muscle vessel was evaluated, to explore the role of vasculopathy and ischemic events in the pathogenesis of mitochondrial encephalomyopathies. METHODS: Computed tomography perfusion (CTP) imaging was applied to the evaluation of brain perfusion during the symptomatic period of mitochondrial encephalomyopathies. Mitochondria structures in the blood vessels wall within muscle fibers were observed by light and electron microscopy analyses. RESULTS: Neuroimaging studies demonstrated uni- and bilateral lesions predominantly in the occipital and temporal-parietal lobes. Compared with the healthy control subjects, significant decreases in cerebral blood flow and cerebral blood volume were noted in affected brain areas of individuals with MELAS. In particular, mean transit time and the time to peak were prolonged both in lesion and non-lesion brain areas. Muscle pathology showed large granular deposits on vessel wall as demonstrated by succinic acid dehydrogenase staining. Electron microscopy of blood vessels revealed swelling of cristae and a striking increase in the number of mitochondria in the smooth muscle and endothelial cells. CONCLUSION: Insufficient cerebral perfusion or vascular reserve and secondary metabolic dysfunction may represent an important feature of the pathogenesis of the stroke-like episodes in MELAS.
Assuntos
Transtornos Cerebrovasculares/patologia , Transtornos Cerebrovasculares/fisiopatologia , Síndrome MELAS/patologia , Síndrome MELAS/fisiopatologia , Adolescente , Adulto , Angiografia Cerebral , Artérias Cerebrais/patologia , Artérias Cerebrais/fisiopatologia , Córtex Cerebral/irrigação sanguínea , Córtex Cerebral/patologia , Córtex Cerebral/fisiopatologia , Circulação Cerebrovascular/fisiologia , Transtornos Cerebrovasculares/etiologia , Células Endoteliais/patologia , Feminino , Humanos , Síndrome MELAS/complicações , Masculino , Microscopia Eletrônica de Transmissão , Músculo Liso Vascular/patologia , Músculo Liso Vascular/fisiopatologia , Tomografia Computadorizada por Raios X , Adulto JovemRESUMO
OBJECTIVE: To investigate the ultrastructural features of mitochondrial cytopathies and its diagnostic value. METHODS: Muscle biopsy specimens from 33 cases of mitochondrial cytopathies were examined by routine pathological and electron microscopic examinations. RESULTS: The main pathologic changes included ragged red fibers in modified Gomori staining, hyper-intense staining myofibers in SDH, COX-negative fibers while dark counterstaining with SDH in COX/SDH double staining technique. Ultrastructural findings included subsarcolemmal and intramyofibrillar proliferation of mitochondria and the appearance of abnormal mitochondria, paracrystalline inclusions, concentric dystrophic cristae and excessive subsarcolemmal glycolipid compounds in subsarcolemmal. CONCLUSION: The presence of proliferation and abnormality of mitochondria, electro-dense granule and paracrystalline inclusions in mitochondria provide key diagnostic evidence for the diagnosis of this disease.
Assuntos
Mitocôndrias Musculares/patologia , Miopatias Mitocondriais/patologia , Músculo Esquelético/patologia , Adolescente , Adulto , Criança , Feminino , Humanos , Masculino , Mitocôndrias Musculares/ultraestrutura , Adulto JovemRESUMO
OBJECTIVE: To investigate whether the presence of structured CagA proteins in Western- and Eastern-type Helicobacter pylori (H. pylori) induces different incidences of gastric diseases. METHODS: CagA and phosphorylated CagA were expressed in AGS gastric epithelial cells infected with wild type and mutant strains. The ability of individual CagA was determined by immunoprecipitation and Western blot assay. Morphological changes of these cells were observed under microscope to evaluate the appearance of elongation hummingbird phenotype. RESULTS: The sizes of CagA proteins in different strains were different, and no phosphorylated CagA proteins were detected in wild-type strains. Meanwhile, the kinetics of CagA status in AGS infected with H. pylori was detected. The molecular weight of phosphorylated CagA with the same size of CagA proteins in H. pylori was different in infections with different wild-type strains. CagA and phosphorylated CagA increased in a time-dependent manner after the infection. The hummingbird phenotype with H. pylori for time-course was observed under microscope. Instead of HPK5 strain, the wild-type 26695 strain induced hummingbird phenotype in a time-dependent manner. CONCLUSION: Translocation and phosphorylation of CagA are necessary, but not sufficient, for the induction of hummingbird phenotype in AGS cells.