Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 57
Filtrar
Mais filtros

Bases de dados
País/Região como assunto
Tipo de documento
País de afiliação
Intervalo de ano de publicação
1.
Plant Cell ; 33(1): 66-84, 2021 03 22.
Artigo em Inglês | MEDLINE | ID: mdl-33751089

RESUMO

After double fertilization, zygotic embryogenesis initiates a new life cycle, and stem cell homeostasis in the shoot apical meristem (SAM) and root apical meristem (RAM) allows plants to produce new tissues and organs continuously. Here, we report that mutations in DEAD-BOX RNA HELICASE 27 (RH27) affect zygote division and stem cell homeostasis in Arabidopsis (Arabidopsis thaliana). The strong mutant allele rh27-1 caused a zygote-lethal phenotype, while the weak mutant allele rh27-2 led to minor defects in embryogenesis and severely compromised stem cell homeostasis in the SAM and RAM. RH27 is expressed in embryos from the zygote stage, and in both the SAM and RAM, and RH27 is a nucleus-localized protein. The expression levels of genes related to stem cell homeostasis were elevated in rh27-2 plants, alongside down-regulation of their regulatory microRNAs (miRNAs). Further analyses of rh27-2 plants revealed reduced levels of a large subset of miRNAs and their pri-miRNAs in shoot apices and root tips. In addition, biochemical studies showed that RH27 associates with pri-miRNAs and interacts with miRNA-biogenesis components, including DAWDLE, HYPONASTIC LEAVES 1, and SERRATE. Therefore, we propose that RH27 is a component of the microprocessor complex and is critical for zygote division and stem cell homeostasis.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Núcleo Celular/genética , Núcleo Celular/metabolismo , Desenvolvimento Embrionário/genética , Desenvolvimento Embrionário/fisiologia , Regulação da Expressão Gênica de Plantas/genética , Regulação da Expressão Gênica de Plantas/fisiologia , MicroRNAs/metabolismo , Zigoto/metabolismo
2.
Plant Cell Rep ; 42(2): 309-319, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36445461

RESUMO

KEY MESSAGE: OsVP1 and Sdr4 play an important role in regulating seed dormancy that involved in multiple metabolism and regulatory pathways. Seed dormancy and germination are critical agricultural traits influencing rice grain yield. Although there are some genes have identified previously, the comprehensive understanding based on transcriptome is still deficient. In this study, we generated mutants of two representative regulators of seed germination, Oryza sativa Viviparous1 (OsVP1) and Seed dormancy 4 (Sdr4), by CRISPR/Cas9 approach and named them cr-osvp1 and cr-sdr4. The weakened dormancy of mutants indicated that the functions of OsVP1 and Sdr4 are required for normal early seed dormancy. There were 4157 and 8285 differentially expressed genes (DEGs) were identified in cr-osvp1 vs. NIP and cr-sdr4 vs. NIP groups, respectively, with a large number of overlapped DEGs between two groups. The gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis of common DEGs in two groups showed that genes related to carbohydrate metabolic, nucleoside metabolic, amylase activity and plant hormone signal transduction were involved in the dormancy regulation. These results suggest that OsVP1 and Sdr4 play an important role in regulating seed dormancy by multiple metabolism and regulatory pathways. The systematic analysis of the transcriptional level changes provides theoretical basis for the research of seed dormancy and germination in rice.


Assuntos
Oryza , Dormência de Plantas , Dormência de Plantas/genética , Oryza/genética , Oryza/metabolismo , Germinação/genética , Perfilação da Expressão Gênica , Reguladores de Crescimento de Plantas/metabolismo , Transcriptoma/genética , Sementes/genética , Sementes/metabolismo , Regulação da Expressão Gênica de Plantas/genética
3.
Biochem Biophys Res Commun ; 522(2): 348-354, 2020 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-31761324

RESUMO

Chaperone-mediated autophagy (CMA) is one of the three types of autophagy. In recent years, CMA has been shown to be associated with the pathogenesis of several types of cancer. However, whether CMA is involved in the pathogenesis of colorectal cancer (CRC) remains unclear. In this study, we investigated CMA activity in tissue specimens from CRC patients and mouse models of colitis-associated CRC (induced by administration of AOM plus DSS). In addition, we down-regulated CMA in CT26 colon carcinoma cells stably transfected with a vector expressing a siRNA targeting LAMP-2A, the limiting component in the CMA pathway, to explore the role of CMA in these cells. Apoptosis was detected using TUNEL assay, and the apoptosis-related proteins were detected using western blotting. Cell proliferation was assessed using MTT assay, Ki-67 labelling and western blotting for PCNA. We found that LAMP-2A expression was significantly increased in CRC patients and mouse models and varied according to the stage of the disease. Inhibition of CMA in CT26 cells facilitated apoptosis, as evidenced by increased TUNEL immunolabeling, increased expression of Bax and Bnip3, and decreased expression of Bcl-2. Cell proliferation assays showed that inhibition of CMA impeded the proliferation of CT26 cells. These data support the hypothesis that CMA is up-regulated in CRC, and inhibition of CMA may be a new therapeutic strategy for CRC patients.


Assuntos
Apoptose , Autofagia Mediada por Chaperonas , Neoplasias do Colo/patologia , Animais , Linhagem Celular Tumoral , Proliferação de Células , Humanos , Proteína 2 de Membrana Associada ao Lisossomo/metabolismo , Masculino , Camundongos Endogâmicos BALB C , Estadiamento de Neoplasias
4.
J Org Chem ; 84(4): 2297-2306, 2019 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-30632746

RESUMO

A palladium-catalyzed ring-opening oxo-formal [3 + 2]-cycloaddition reaction of novel donor-acceptor spirovinylcyclopropyl oxindole with 3-oxindole is described. The developed protocol provides facile access to oxo-bispirooxindole derivatives in good yields (up to 82% yield) with excellent diastereoselectivities (up to 20:1 dr).

5.
J Integr Plant Biol ; 61(10): 1043-1061, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31127689

RESUMO

The phloem, located within the vascular system, is critical for delivery of nutrients and signaling molecules throughout the plant body. Although the morphological process and several factors regulating phloem differentiation have been reported, the molecular mechanism underlying its initiation remains largely unknown. Here, we report that the small peptide-coding gene, CLAVATA 3 (CLV3)/EMBEYO SURROUNDING REGION 25 (CLE25), the expression of which begins in provascular initial cells of 64-cell-staged embryos, and continues in sieve element-procambium stem cells and phloem lineage cells, during post-embryonic root development, facilitates phloem initiation in Arabidopsis. Knockout of CLE25 led to delayed protophloem formation, and in situ expression of an antagonistic CLE25G6T peptide compromised the fate-determining periclinal division of the sieve element precursor cell and the continuity of the phloem in roots. In stems of CLE25G6T plants the phloem formation was also compromised, and procambial cells were over-accumulated. Genetic and biochemical analyses indicated that a complex, consisting of the CLE-RESISTANT RECEPTOR KINASE (CLERK) leucine-rich repeat (LRR) receptor kinase and the CLV2 LRR receptor-like protein, is involved in perceiving the CLE25 peptide. Similar to CLE25, CLERK was also expressed during early embryogenesis. Taken together, our findings suggest that CLE25 regulates phloem initiation in Arabidopsis through a CLERK-CLV2 receptor complex.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Floema/metabolismo , Raízes de Plantas/metabolismo , Plantas Geneticamente Modificadas/metabolismo , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Regulação da Expressão Gênica de Plantas/genética , Regulação da Expressão Gênica de Plantas/fisiologia , Raízes de Plantas/genética , Plantas Geneticamente Modificadas/genética , Transdução de Sinais/genética , Transdução de Sinais/fisiologia
6.
J Mol Cell Cardiol ; 114: 243-252, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-29196099

RESUMO

AIMS: Cardiac pressure and humoral factors induce cardiac hypertrophy and fibrosis, which are characterized by increased stiffness, reduced contractility and altered perfusion. Angiotensin II (AngII) is well known to promote this pathology. Angiotensin-converting enzyme (ACE) 2, which cleaves AngII and forms Ang-(1-7), exerts protective anti-hypertrophy and anti-fibrosis effects. A disintegrin and metalloproteinase 17 (ADAM17), a membrane-bound enzyme reported to cleave ACE2, may participate in the pathological process of AngII perfusion-induced heart damage. However, researchers have not clearly determined whether dickkopf-3 (DKK3) regulates the ADAM17/ACE2 pathway and, if so, whether DKK3-mediated regulation is related to the glycogen synthase kinase-3ß (GSK-3ß)/ß-catenin pathway. In this study, we explored whether DKK3 overexpression ameliorates the development of AngII-induced cardiac fibrosis and hypertrophy through the ADAM17/ACE2 and GSK-3ß/ß-catenin pathways. METHODS: Mice were injected with a DKK3-overexpressing adenovirus or vehicle and then infused with AngII or saline using subcutaneously implanted mini-pumps for four weeks. Hearts were stained with hematoxylin-eosin, Masson's trichrome and immunohistochemical markers for histology. Primary fibroblasts were treated with the adenovirus and AngII and then examined using western blotting, EdU (5-ethynyl-2'-deoxyuridine) assays and immunofluorescence. Additionally, siRNA silencing was performed to study the role of DKK3 and the involved pathways. RESULTS: AngII-induced cardiac hypertrophy and interstitial and perivascular fibrosis were less severe in DKK3-overexpressing mice than in control mice. Moreover, the expression levels of fibrotic genes, such as collagen I and III, and the hypertrophic genes atrial natriuretic peptide (ANP) and beta-myosin heavy chain (ß-MHC) were decreased. DKK3 overexpression also exerted a protective effect by inhibiting ADAM17 phosphorylation, thus increasing ACE2 expression and subsequently promoting AngII degradation. Furthermore, this process was mediated by the inhibition of GSK-3ß and ß-catenin and decreased translocation of ß-catenin to the nucleus. On the other hand, the DKK3 knockdown by siRNA achieved opposite results. CONCLUSION: DKK3 overexpression substantially alleviated AngII infusion-induced cardiac hypertrophy and fibrosis by regulating ADAM17/ACE2 pathway activity and inhibiting the GSK-3ß/ß-catenin pathway.


Assuntos
Proteína ADAM17/metabolismo , Angiotensina II/farmacologia , Cardiomegalia/metabolismo , Cardiomegalia/patologia , Glicogênio Sintase Quinase 3 beta/metabolismo , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Transdução de Sinais , beta Catenina/metabolismo , Proteínas Adaptadoras de Transdução de Sinal , Angiotensina I , Enzima de Conversão de Angiotensina 2 , Animais , Animais Recém-Nascidos , Apoptose/efeitos dos fármacos , Cardiomegalia/fisiopatologia , Proliferação de Células/efeitos dos fármacos , Modelos Animais de Doenças , Fibroblastos/efeitos dos fármacos , Fibroblastos/metabolismo , Fibroblastos/patologia , Fibrose , Inflamação/patologia , Metaloproteinases da Matriz/metabolismo , Camundongos Endogâmicos C57BL , Fragmentos de Peptídeos , Peptidil Dipeptidase A/metabolismo , Perfusão , Fosforilação/efeitos dos fármacos , Proteína Smad3/metabolismo , Fator de Crescimento Transformador beta1/metabolismo
7.
Biochim Biophys Acta Mol Basis Dis ; 1864(5 Pt A): 1754-1769, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29510196

RESUMO

Glioblastoma multiforme (GBM) is the most aggressive primary brain tumor due to the lack of effective therapeutic drugs. Cancer therapy targeting programmed cell death protein 1 (PD-1) or programmed death ligand-1 (PD-L1) is of revolutionary. However, the role of intrinsic PD-L1, which determines immune-therapy outcomes, remains largely unclear. Here we demonstrated an oncogenic role of PD-L1 via binding and activating Ras in GBM cells. RNA-sequencing transcriptome data revealed that PD-L1 significantly altered gene expression enriched in cell growth/migration/invasion pathways in human GBM cells. PD-L1 overexpression and knockout or knockdown demonstrated that PD-L1 promoted GBM cell proliferation and migration in vitro and in vivo. Mechanistically, PD-L1 prominently activated epithelial mesenchymal transition (EMT) process in a MEK/Erk- but not PI3K/Akt-dependent manner. Further, we identified intracellular interactions of PD-L1 and H-Ras, which led to Ras/Erk/EMT activation. Finally, we demonstrated that PD-L1 overexpression promoted while knockdown abolished GBM development and invasion in orthotopic GBM models of rodents. Taken together, we found that intracellular PD-L1 confers GBM cell malignancy and aggressiveness via binding Ras and activating the downstream Erk-EMT signaling. Thus, these results shed important insights in improving efficacy of immune therapy for GBM as well as other malignant tumors.


Assuntos
Antígeno B7-H1/metabolismo , Transição Epitelial-Mesenquimal , Glioblastoma/metabolismo , Sistema de Sinalização das MAP Quinases , Animais , Antígeno B7-H1/genética , MAP Quinases Reguladas por Sinal Extracelular/genética , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Glioblastoma/genética , Glioblastoma/patologia , Humanos , Gelo , Masculino , Camundongos Endogâmicos BALB C , Camundongos Nus , Fosfatidilinositol 3-Quinases/genética , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteínas Proto-Oncogênicas p21(ras)/genética , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , Ratos , Ratos Sprague-Dawley
10.
Metab Brain Dis ; 33(5): 1721-1731, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30019267

RESUMO

Previous studies have shown that agmatine, a potential neuromodulator or co-transmitter, exhibited antidepressant-like action in animal models, yet its mechanism, especially the receptor mechanism, remains unclear. In the present study, using efaroxan, a preferential antagonist of I1 imidazoline receptor (I1R) and yohimbine, an antagonist of α2 adrenergic receptor (α2AR), we investigated the roles of I1R and α2AR in agmatine's antidepressant-like effect in acute and sub-acute depression models in mice. We found that in the tail-suspension test (TST) and the forced swimming test (FST), acute administration of agmatine (20 and 40 mg/kg, p.o.) significantly shortened the immobility time. Concurrent administration of efaroxan (1 mg/kg, i.p.) completely abolished the antidepressant-like effects of agmatine (40 mg/kg, p.o.) whereas yohimbine (5 mg/kg, i.p.) failed to exert similar effects, suggesting that the acute antidepressant-like effects of agmatine was mainly mediated by I1R but not α2AR. Additionally, in the learned helplessness (LH) test, repeated administration of agmatine (20 mg/kg, p.o., q.d.) for 5 days significantly decreased the escape latency and the number of escape failure, and these effects were respectively abolished by concurrent administration of efaroxan (0.5 mg/kg,i.p., q.d.) and yohimbine (3 mg/kg, i.p., q.d.) for 5 days, suggesting that the antidepressant-like action of agmatine in the LH test was achieved via the activation of both I1R and α2AR. In summary, we found that the antidepressant-like effects of agmatine in the TST and the FST were mediated by activating I1R and in the sub-acute LH test were mediated by activating both I1R and α2AR.


Assuntos
Agmatina/uso terapêutico , Antidepressivos/uso terapêutico , Comportamento Animal/efeitos dos fármacos , Depressão/tratamento farmacológico , Atividade Motora/efeitos dos fármacos , Antagonistas Adrenérgicos alfa/farmacologia , Agmatina/farmacologia , Animais , Antidepressivos/farmacologia , Benzofuranos/farmacologia , Modelos Animais de Doenças , Elevação dos Membros Posteriores , Imidazóis/farmacologia , Receptores de Imidazolinas/antagonistas & inibidores , Masculino , Camundongos , Natação , Ioimbina/farmacologia
11.
Acta Haematol ; 135(2): 88-93, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26505491

RESUMO

BACKGROUND: Osmotic fragility testing based on flow cytometry was recently introduced for the screening of hereditary spherocytosis (HS). This study was undertaken to evaluate the clinical diagnostic value of a flow-cytometric osmotic fragility test for HS. METHODS: Peripheral blood was collected from 237 subjects at the First Affiliated Hospital of Guangxi Medical University, including 56 HS patients, 86 thalassemia patients and 95 healthy controls. The samples were examined by flow-cytometric osmotic fragility test and the percentage of residual red blood cells was used to determine HS. Peripheral blood smears were performed to examine the red blood cell morphology. RESULTS: With clinical diagnosis of HS as the gold standard and the percentage of residual red blood cells <23.6% as the diagnostic threshold in the flow-cytometric osmotic fragility test, the sensitivity of the flow-cytometric osmotic fragility test for HS was 85.71% and the specificity was 97.24%. CONCLUSION: The flow-cytometric osmotic fragility test combined with a red blood cell morphology test by peripheral blood smear could be a simple, practical and accurate laboratory screening method for HS.


Assuntos
Fragilidade Osmótica/fisiologia , Esferocitose Hereditária/diagnóstico , Adolescente , Adulto , Área Sob a Curva , Povo Asiático , Estudos de Casos e Controles , Criança , Pré-Escolar , China , Feminino , Citometria de Fluxo , Humanos , Masculino , Pessoa de Meia-Idade , Pacientes , Curva ROC , Esferocitose Hereditária/patologia , Talassemia/diagnóstico , Talassemia/patologia , Adulto Jovem
12.
Ann Hematol ; 94(5): 747-51, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25501660

RESUMO

The objective of this study is to compare and evaluate the diagnostic value of hereditary spherocytosis (HS) by three screening tests, comparing mean spherical corpuscular volume (MSCV) to mean corpuscular volume (MCV), mean corpuscular hemoglobin concentration (MCHC), and flow cytometric osmotic fragility test. Peripheral blood was collected from 237 participators diagnosed at the First Affiliated Hospital of Guangxi Medical University, including 56 hereditary spherocytosis patients, 86 thalassemia patients, and 95 healthy people. The samples were examined by three tests, and the three screening tests were evaluated by the sensitivity and specificity of tests. The sensitivity was only 41.07%, and specificity was 94.47% when using MCHC >355 g/L as diagnostic criteria. The sensitivity was 89.28%, and specificity was 96.14% when using MSCV < MCV as the optimum cutoff point. When using the residual red cell percentage <23.6% as the diagnostic threshold in flow cytometric osmotic fragility test, the sensitivity was 85.71% and the specificity was 97.24%. Flow cytometry osmotic fragility test or comparing MSCV to MCV combined with smear examination of peripheral red blood cells morphology can be a simple, practical, and accurate hereditary spherocytosis (HS) laboratory screening method.


Assuntos
Anquirinas/deficiência , Esferocitose Hereditária/diagnóstico , Adolescente , Adulto , Criança , Pré-Escolar , Eritrócitos/metabolismo , Feminino , Citometria de Fluxo , Hemoglobinas/metabolismo , Humanos , Masculino , Fragilidade Osmótica/fisiologia , Talassemia/diagnóstico , Adulto Jovem
13.
Chemistry ; 20(51): 16980-6, 2014 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-25339060

RESUMO

For a complementary hydrogen-bonded complex, when every hydrogen-bond acceptor is on one side and every hydrogen-bond donor is on the other, all secondary interactions are attractive and the complex is highly stable. AAA-DDD (A=acceptor, D=donor) is considered to be the most stable among triply hydrogen-bonded sequences. The easily synthesized and further derivatized AAA-DDD system is very desirable for hydrogen-bonded functional materials. In this case, AAA and DDD, starting from 4-methoxybenzaldehyde, were synthesized with the Hantzsch pyridine synthesis and Friedländer annulation reaction. The association constant determined by fluorescence titration in chloroform at room temperature is 2.09×10(7) M(-1) . The AAA and DDD components are not coplanar, but form a V shape in the solid state. Supramolecular polymers based on AAA-DDD triply hydrogen bonded have also been developed. This work may make AAA-DDD triply hydrogen-bonded sequences easily accessible for stimuli-responsive materials.

14.
Clin Exp Pharmacol Physiol ; 41(11): 863-9, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25224515

RESUMO

The chemokine, fractalkine, independently enhances the vulnerability of coronary atherosclerotic plaques. The present study investigated the combined effects of CD36 and fractalkine on coronary plaque progression in patients with unstable angina pectoris. In the present study, 120 unstable angina pectoris patients undergoing coronary angiography and intravascular ultrasound were divided into two groups: an intermediate lesion group (lumen diameter stenosis 50-70%, 80 patients) and a severe lesion group (at least one lesion with lumen diameter stenosis > 70%, 40 patients). The control group consisted of 40 healthy age- and sex-matched subjects. Concentrations of CD36 and fractalkine were measured by enzyme-linked immunosorbent assay. Major adverse cardiovascular events were monitored over a 2-year follow up. Intravascular ultrasound showed that patients with severe lesions had more calcified and mixed plaques, and a larger plaque area and plaque burden than patients with intermediate lesions (P < 0.05-0.01). More patients with severe lesions underwent stent deployment (P < 0.05) than those with intermediate lesions. CD36 and fractalkine concentrations were significantly higher in the severe lesion patients (P < 0.05), and both had significant positive correlations (P < 0.05) with the plaque burden of atherosclerotic lesions. Using the matched nested case-control study, we found that CD36 and fractalkine levels were higher in patients with recurrent major adverse cardiovascular events than controls (P < 0.05). In conclusion, CD36 and fractalkine both promote, and might synergistically enhance, the progression of coronary atherosclerotic plaques.


Assuntos
Angina Instável/patologia , Antígenos CD36/sangue , Quimiocina CX3CL1/sangue , Estenose Coronária/patologia , Placa Aterosclerótica/patologia , Idoso , Idoso de 80 Anos ou mais , Angina Instável/sangue , Angina Instável/diagnóstico por imagem , Biomarcadores/sangue , Estudos de Casos e Controles , Angiografia Coronária , Estenose Coronária/sangue , Estenose Coronária/diagnóstico por imagem , Progressão da Doença , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Placa Aterosclerótica/sangue , Placa Aterosclerótica/diagnóstico por imagem , Ultrassonografia de Intervenção
15.
Neural Regen Res ; 17(10): 2238-2246, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35259844

RESUMO

Extracellular vesicles (EVs) from mesenchymal stromal cells (MSCs) have previously been shown to protect against brain injury caused by hypoxia-ischemia (HI). The neuroprotective effects have been found to relate to the anti-inflammatory effects of EVs. However, the underlying mechanisms have not previously been determined. In this study, we induced oxygen-glucose deprivation in BV-2 cells (a microglia cell line), which mimics HI in vitro, and found that treatment with MSCs-EVs increased the cell viability. The treatment was also found to reduce the expression of pro-inflammatory cytokines, induce the polarization of microglia towards the M2 phenotype, and suppress the phosphorylation of selective signal transducer and activator of transcription 3 (STAT3) in the microglia. These results were also obtained in vivo using neonatal mice with induced HI. We investigated the potential role of miR-21a-5p in mediating these effects, as it is the most highly expressed miRNA in MSCs-EVs and interacts with the STAT3 pathway. We found that treatment with MSCs-EVs increased the levels of miR-21a-5p in BV-2 cells, which had been lowered following oxygen-glucose deprivation. When the level of miR-21a-5p in the MSCs-EVs was reduced, the effects on microglial polarization and STAT3 phosphorylation were reduced, for both the in vitro and in vivo HI models. These results indicate that MSCs-EVs attenuate HI brain injury in neonatal mice by shuttling miR-21a-5p, which induces microglial M2 polarization by targeting STAT3.

16.
Zhongguo Wei Zhong Bing Ji Jiu Yi Xue ; 23(12): 743-8, 2011 Dec.
Artigo em Zh | MEDLINE | ID: mdl-22153013

RESUMO

OBJECTIVE: To examine the impact of mild hypothermia on cardiac function, myocardial tissue integrity, and 48 hours mortality in a rabbits model of ventricular fibrillation after restoration of spontaneous circulation (ROSC). METHODS: The rabbits were randomly divided into four groups: normothermic post ROSC (NTPR, n = 10), mild hypothermia post ROSC (HTPR, n = 10), normothermic control (NTC, n = 8) and mild hypothermia control (HTC, n = 8). Ventricular fibrillation was induced by trans-epicardium electric-shook with alternating current in all the animals and ROSC was achieved through administration of adrenaline (i.v.) and artificial ventilation in group NTPR and HTPR. The body temperature of the animals was kept either at (39.0 ± 0.5) centigrade (NTPR and NTC) or (33.5 ± 0.5) centigrade (HTPR and HTC) for 4 hours after surgery for hemodynamic index data collection 0.5, 1, 2, 3 and 4 hours after surgery, 48 hours later, the mortality in the animals was recorded, and myocardial tissue samples were collected from survived animals for morphological examination by light and electric microscopy and analysis of apoptosis by terminal-deoxynucleotidyl transferase mediated nick end labeling (TUNEL) staining. The content of ATP, ADP and AMP in the tissue samples was measured by high performance liquid chromatography (HPLC) for the calculation of energy charges (EC). RESULTS: (1)Hemodynamic indexes: as compared to the NTC group, HTC group exhibited significantly lower levels of heart rate (HR) and -dp/dt max in all the time points. No significant difference between the two groups in the levels of +dp/dt max and mean artery pressure (MAP) was found in all the time points but 0.5 hour. There was no significant difference in the levels of left ventricular end-diastolic pressure (LVEDP), left ventricular end-systolic pressure (LVESP), and femoral artery blood pressure between the two groups.(2) In comparison with NTPR group, HTPR group exhibited significantly (all P < 0.05) lower levels of HR (bpm) and -dp/dt max in all time points (ROSC 0.5, 1, 2, 3, 4 hours: HR 216.5 ± 33.3 vs. 292.9 ± 38.4, 218.2 ± 28.0 vs. 294.3 ± 37.0, 227.5 ± 25.4 vs. 291.4 ± 25.3, 232.4 ± 27.4 vs. 278.1 ± 30.8, 230.6 ± 22.0 vs. 285.1 ± 38.2; -dp/dt max 1847.1 ± 241.2 vs. 2383.3 ± 470.9, 1860.7 ± 167.8 vs. 2154.6 ± 319.5, 1822.3 ± 389.7 vs. 2239.7 ± 379.0, 1950.6 ± 412.9 vs. 2229.6 ± 392.4, 1875.7 ± 555.6 vs. 2396.7 ± 420.1). There was no significant difference between the two groups in the levels of LVEDP, +dp/dt max, LVESP, and femoral artery blood pressure. (3)Optical and electron microscopy revealed myocardium injury in samples from animals underwent ROSC. However, in comparison with the NTPR group, samples from HTPR group exhibited less damage to the myocardium structure. (4) Apoptosis index (AI) of myocardium was significantly (P < 0.05) higher in NTPR group (42.02%) than in HTPR group (26.39%). (5) Tests of myocardial energy: ATP level (µmol/g) in HTPR was significantly (P < 0.05) higher than NTPR (0.97 ± 0.26 vs. 0.65 ± 0.16). EC in NTPR was significant lower than it in two control groups [(0.33 ± 0.13)% vs. (0.52 ± 0.12)%, (0.55 ± 0.06)%, both P < 0.05], whereas no such difference was found between HTPR [(0.41 ± 0.12)%] and two control groups. (6) 48 hours survival rate in HTPR group was significantly higher (P = 0.043) as compared to NTPR group (100% vs. 60%). CONCLUSIONS: Myocardial dysfunction and myocardium tissue injury both develop in post-resuscitation rabbits with ventricular fibrillation. In these animals, reducing body temperature to the level of mild hypothermia after ROSC may improve the 48 hours survival rate, probably via mechanisms that suppress myocardial cell apoptosis. In our study, such intervention produced no obvious negative impact neither on the cardiac function nor hemodynamics.


Assuntos
Hipotermia Induzida , Miocárdio/patologia , Ressuscitação , Fibrilação Ventricular/patologia , Fibrilação Ventricular/fisiopatologia , Animais , Masculino , Coelhos
17.
Zhonghua Xin Xue Guan Bing Za Zhi ; 39(4): 343-7, 2011 Apr.
Artigo em Zh | MEDLINE | ID: mdl-21624311

RESUMO

OBJECTIVE: To detect the optimal predictors of vulnerable atherosclerotic plaques. METHODS: Forty New Zealand white rabbits underwent balloon-induced abdominal aortic wall injury and were fed a high cholesterol and saturated fat diet containing 1% cholesterol for 8 weeks. Rabbits were then randomly divided into two groups: group A (n = 20, the aortic segments rich in plaques were incubated transluminally with recombinant adenovirus carrying p53) and group B [n = 20, incubated transluminally with ß galactosidase (LacZ) genes]. Two weeks later, rabbits underwent pharmacological triggering with injection of Chinese Russell's viper venom (CRVV) and histamine. Before pharmacologically triggering, concentrations of hs-CRP, sVCAM-1 and sICAM-1 were measured by means of Enzyme-linked-immunosorbent assay (ELISA). Fibrinogen was analyzed by nephelometer. Ultrasound imaging, accuracy densitometry (AD) examination and intravascular ultrasound (IVUS) were performed to analyze the in vivo features of vulnerable plaques. Logistic regression was used to detect the predictors for vulnerable plaques. RESULTS: The ratio of plaque rupture after pharmacological triggering was significantly higher in group A (89.5%, 17/19) than in group B (22.2%, 4/18). Serum hs-CRP level was significantly higher in plaque rupture group than in non-rupture group before pharmacological triggering (P < 0.05). In the meantime, parameters derived from ultrasound imaging [intima-media thickness (IMT) and peak velocity (VP), values of accuracy densitometry], measurements of IVUS [external elastic membrance area (EEMA), plaque area (PA), plaque burden (PB), eccentric index (EI) and remodeling index (RI)] were significantly larger in plaque rupture group than in non-rupture group. Logistic regression showed that EI (OR = 26.917), PA (OR = 19.301), sVCAM-1 (OR = 1.339) and AII-c% (OR = 0.458) were independent predictors for plaque rupture (all P < 0.05). CONCLUSION: The major predictors of vulnerable plaques were eccentric index (EI) and plaque area (PA), sVCAM-1 and AII-c% in this model.


Assuntos
Aterosclerose/diagnóstico , Placa Aterosclerótica/diagnóstico , Molécula 1 de Adesão de Célula Vascular/sangue , Animais , Aterosclerose/diagnóstico por imagem , Proteína C-Reativa/análise , Colesterol na Dieta/administração & dosagem , Dieta Hiperlipídica , Modelos Animais de Doenças , Diagnóstico Precoce , Masculino , Placa Aterosclerótica/diagnóstico por imagem , Coelhos , Ultrassonografia
18.
Zhonghua Xin Xue Guan Bing Za Zhi ; 39(9): 797-801, 2011 Sep.
Artigo em Zh | MEDLINE | ID: mdl-22321225

RESUMO

OBJECTIVE: To elucidate the roles of monocyte chemotactic factors (MCP-1, RANTES and Fractalkine) on the vulnerability of atherosclerotic plaques in patients with stable (SAP) and unstable angina pectoris (UAP). METHODS: Patients with SAP (n = 50) and UAP (n = 50) underwent coronary angiography (CAG) and intravenous ultrasound (IVUS) were included in the study. Monocyte chemotaxis was assayed by the transwell chamber. Concentrations of hs-CRP, MCP-1, RANTES and Fractalkine were measured by Enzyme-linked-immunosorbent assay (ELISA). mRNA expression of MCP-1, RANTES and Fractalkine in the monocytes was detected by RT-PCR. RESULTS: IVUS evidenced soft lipid plaques in 48% UAP patients and in 16% SAP patients (P < 0.05). SAP patients had mainly fibrous and mixed plaques. Plaque burden and vascular remodeling index were significantly higher in UAP patients than in SAP patients (P < 0.01). The averaged number of migrated monocytes in the UAP patients were higher than that in patients with SAP (P < 0.01). Concentration of hs-CRP, MCP-1, RANTES and Fractalkine were significantly higher in UAP patients than those of SAP patients (P < 0.05 or P < 0.01). mRNA expression of MCP-1, RANTES and Fractalkine in patients with UAP was significantly higher than those of SAP patients (P < 0.05). CONCLUSION: Upregulated monocyte chemotactic factors (MCP-1, RANTES and Fractalkine) might promote coronary plaque vulnerability in UAP patients.


Assuntos
Angina Pectoris/metabolismo , Angina Instável/metabolismo , Quimiocina CCL2/metabolismo , Quimiocina CCL5/metabolismo , Quimiocina CX3CL1/metabolismo , Placa Aterosclerótica/patologia , Angina Pectoris/patologia , Angina Instável/patologia , Angiografia Coronária , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , RNA Mensageiro/genética
19.
Front Bioeng Biotechnol ; 9: 764306, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34881235

RESUMO

The nucleic acid-based technique has been widely utilized in many fields including for on-site detection. However, traditional molecular detection techniques encounter limitations like relying on instruments, time consuming or complex operation, and cannot meet the demands of on-site testing. In this study, a rapid DNA extraction method (RDEM), recombinase aided amplification (RAA), and chemical heating packet (CHP) are integrated and termed as RRC platform for on-site detection of nucleic acid. For demonstration purposes, SHZD32-1 (a new transgenic soybean line from China) was detected using the novel platform to demonstrate its feasibility and capability for on-site detection. Using the RDEM, high-quality DNA appropriate for molecular detection was quickly extracted in 3-5 min. The heat energy generated by CHP was met the temperature requirements of RAA. Using the RRC platform, the whole detection process can be accomplished within only 30 min, and the results can be visually detected with glasses under blue light. No special or expensive instrument was needed for the detection process. This study provides a novel approach for on-site detection of nucleic acids besides providing valuable insight on related future research.

20.
J Cardiovasc Transl Res ; 14(4): 661-669, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-32285315

RESUMO

Chaperone-mediated autophagy (CMA) serves as a critical upstream regulator of lipophagy and lipid metabolism in hepatocyte. However, the role of CMA in lipid metabolism of macrophage, the typical component of atherosclerotic plaque, remains unclear. In our study, LAMP-2A (L2A, a CMA marker) was reduced in macrophages exposed to high dose of oleate, and lipophagy was impaired in advanced atherosclerosis in ApoE (-/-) mice. Primary peritoneal macrophages isolated from macrophage-specific L2A-deficient mice exhibited pronounced intracellular lipid accumulation. Lipid regulatory enzymes, including long-chain-fatty-acid-CoA ligase 1 (ACSL1) and lysosomal acid lipase (LAL), were increased and reduced in L2A-KO macrophage, respectively. Other lipid-related proteins, such as SR-A, SR-B (CD36), ABCA1, or PLIN2, were not associated with increased lipid content in L2A-KO macrophage. In conclusion, deficient CMA promotes lipid accumulation in macrophage probably by regulating enzymes involved in lipid metabolism. CMA may represent a novel therapeutic target to alleviate atherosclerosis by promoting lipid metabolism. Graphical abstract.


Assuntos
Aterosclerose/metabolismo , Autofagia , Metabolismo dos Lipídeos , Proteína 2 de Membrana Associada ao Lisossomo/metabolismo , Macrófagos Peritoneais/metabolismo , Animais , Aterosclerose/genética , Aterosclerose/patologia , Autofagia/efeitos dos fármacos , Células Cultivadas , Coenzima A Ligases/metabolismo , Modelos Animais de Doenças , Metabolismo dos Lipídeos/efeitos dos fármacos , Proteína 2 de Membrana Associada ao Lisossomo/genética , Macrófagos Peritoneais/efeitos dos fármacos , Macrófagos Peritoneais/patologia , Masculino , Camundongos Endogâmicos C57BL , Camundongos Knockout para ApoE , Ácido Oleico/toxicidade , Esterol Esterase/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA