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1.
Heliyon ; 10(5): e27345, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38495161

RESUMO

Background: Compound Taxus capsule, as an antineoplastic Chinese patent drug, has been increasingly applied as an adjunctive treatment for the management of non-small-cell lung cancer (NSCLC) and some other malignancies, but research about its antitumor activity and radiosensitization effect on hepatocellular carcinoma (HCC) cells is very rare. Purpose: To investigate the antitumor activity and radiosensitization effect of Compound Taxus on HCC cells and to preliminarily explore the possible molecule mechanisms involved. Methods: Cell viability, cell cycle distribution, apoptosis, DNA damage repair and protein expression levels were detected by CCK-8 assay, flow cytometry, immunofluorescence staining, western blotting analysis and immunohistochemical staining, respectively. The migration and invasion activities and vasculogenic mimicry (VM) formation and angiogenesis were evaluated by tube formation and VM formation assay. Radiation survival curves were obtained from the colony formation assay in human HCC cell lines, Smmc7721 and Bel7402 cells, pretreated with or without Compound Taxus before receiving X-ray irradiation. A Bel7402 tumor-bearing mouse model was established and the radiosensitization effect of Compound Taxus in vivo was evaluated by analyzing tumor volume and tumor weight in different groups receiving different treatments. Results: Compound Taxus decreased viability, induced G2/M arrest, promoted apoptosis, suppressed migration and invasion, and inhibited VM formation and angiogenesis in Smmc7721 and Bel7402 cells. Furthermore, Compound Taxus inhibited irradiation-induced DNA damage repair, enhanced the radiosensitivity of Smmc7721 and Bel7402 cells and improved the anti-tumor therapeutic efficacy of irradiation in Bel7402 tumor-bearing mice. Radiotherapy in combination with Compound Taxus showed the best tumor inhibition compared to that of Compound Taxus alone or irradiation alone. In addition, Compound Taxus significantly down-regulated NF-κB p65, p-NF-κB p65 and Bcl-2, and up-regulated Bax in vitro and in vivo, yet NF-κB p65 overexpression reversed the proapoptotic effect of Taxus on HCC cells, indicating that the NF-κB signaling pathway might be an important signal mediator in the Compound-Taxus-modulated biological responses. Conclusion: Our findings suggest that Compound Taxus shows marked antitumor activity and significant radiosensitization effect on HCC cells, making it possible for Compound Taxus to become a promising auxiliary modality for HCC management and a potential radiosensitizer of HCC in the future.

2.
Quant Imaging Med Surg ; 14(1): 1241-1244, 2024 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-38223083
3.
Clin Lab ; 69(12)2023 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-38084683

RESUMO

BACKGROUND: Urachal remnants (URs) represent uncommon and underdiagnosed entities that are usually detected incidentally at imaging or present clinically different manifestations. METHODS: Here we presented a boy with UR infection. Ultrasonography and bacterial culture and identification were performed. He received antibiotic treatment and underwent surgical excision of the cyst. RESULTS: The patient presented with both a urachal cyst and umbilical-urachal sinus. UR infection was caused by Actinomyces turicensis. He recovered well from the operation without complications. CONCLUSIONS: The present case reminds clinicians to be familiar with imaging features of different types of URs and their potential complications and indicates the necessity of pathogenic microorganism analysis to tailor antibiotic treatment and post-operative follow-up to prevent complications.


Assuntos
Laparoscopia , Cisto do Úraco , Úraco , Masculino , Humanos , Laparoscopia/métodos , Úraco/cirurgia , Cisto do Úraco/diagnóstico , Cisto do Úraco/cirurgia , Antibacterianos/uso terapêutico
5.
Clin Lab ; 69(1)2023 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-36649509

RESUMO

BACKGROUND: COVID-19 and malaria share some similar symptoms such as fever, difficulty in breathing, fatigue, and headaches of acute onset. With overlapping symptoms and travel history significant for COVID-19 and malaria, healthcare systems and professionals will face a great challenge in the case of COVID-19 and malaria co-infection. METHODS: Here we presented a patient with COVID-19 infection and refractory anemia of unknown reason. A diagnostic test for malaria was later performed. RESULTS: The patient was ultimately diagnosed with COVID-19 and plasmodium falciparum malaria co-infection. He recovered gradually after receiving anti-malaria treatment. CONCLUSIONS: The present case highlights the danger of focusing only on a diagnosis of COVID-19, reminding clinicians to be vigilant about the possibility of co-infections.


Assuntos
Anemia , COVID-19 , Coinfecção , Malária Falciparum , Malária , Humanos , Masculino , Anemia/diagnóstico , Coinfecção/diagnóstico , COVID-19/complicações , População do Leste Asiático , Malária Falciparum/complicações , Malária Falciparum/diagnóstico , Plasmodium falciparum , China
8.
Clin Lab ; 67(2)2021 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-33616318

RESUMO

BACKGROUND: Gastric cancer is the fifth most common malignancy worldwide. In early stages, no obvious symptoms are usually observed in gastric cancer patients, and it is especially hard to distinguish gastric cancer from benign gastric diseases, resulting in delayed diagnosis and poor prognosis. Common biomarkers of gastric cancer, such as CEA and CA19-9, are also elevated in benign diseases. There is an urgent need to develop a convenient and reliable biomarker for differentiating between gastric cancer and benign gastric diseases. METHODS: This study retrospectively analyzed the data of 126 patients, including 73 gastric cancer patients and 53 benign gastric disease patients. Patient characteristics collected for analysis included age, gender, laboratory data, and clinical staging. Unpaired t-test was used to check the difference of cholinesterase level between the gastric cancer group and the benign gastric disease group. Kruskal Wallis H test and Mann-Whitney U test were used to check the difference of cholinesterase level among different stage groups. Receiver operating characteristic (ROC) curve was used to assess whether cholinesterase level can be used as a biomarker for differentiating between gastric cancer and benign gastric diseases. RESULTS: Serum cholinesterase level was decreased significantly in the gastric cancer group in comparison to that of the benign gastric disease group (p < 0.001). In addition, cholinesterase level of stage IV patients was significantly lower than stage I patients. ROC curve analysis revealed that with a cutoff of 5,969.00 U/L, cholinesterase level showed an area under the curve of 0.819 (95% CI 0.732 - 0.905, p < 0.001) in differentiating between gastric cancer and benign gastric diseases. No significant difference in the levels of CEA and CA19-9 was observed between gastric cancer patients and benign gastric disease patients. CONCLUSIONS: This study indicated that serum cholinesterase level could be considered as a potential biomarker for differentiating between gastric cancer and benign gastric diseases.


Assuntos
Neoplasias Gástricas , Biomarcadores Tumorais , Antígeno CA-19-9 , Antígeno Carcinoembrionário , Colinesterases , Diagnóstico Diferencial , Humanos , Curva ROC , Estudos Retrospectivos , Neoplasias Gástricas/diagnóstico
9.
Transl Cancer Res ; 10(2): 1177-1182, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35116445

RESUMO

Neuroendocrine tumors (NETs) generally arise from endocrine cells of gut and bronchi. Primary NETs of spine are extremely rare and have been described in cervical spine, lumbar spine, sacrum, and coccyx. So far, primary NETs in thoracic spine have not been reported yet. Here we described a 46-year-old Chinese woman with NET in thoracic spine. Neuroimaging revealed a mass behind the vertebral body of T11, abnormal changes in the adnexa and surrounding soft tissue and compression of the spinal cord. She received a total resection of the tumor and T11 corpectomy. Histopathological examination and immunohistochemical staining proved the tumor to be a rare spinal NET. PET-CT and other examinations ruled out the existence of tumors in any other site. So, she was diagnosed with NET of thoracic spine. The patient received postoperative etoposide and nedaplatin chemotherapy for four cycles, and she recovered well with no evidence of tumor recurrence or metastasis during six-month medical follow-up. Spine location of NETs should be first considered as a metastatic disease unless there is proof ruling out the possibility. Complete tumor resection is the most effective therapy in NETs of spine and should be considered in priority, and chemotherapy and radiotherapy should be considered on an individual basis.

11.
Clin Lab ; 62(9): 1675-1681, 2016 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-28164589

RESUMO

BACKGROUND: Acute appendicitis is the most common surgical emergency in pediatrics. In this study, we aimed to evaluate the diagnostic value of D-dimer in differentiating between simple and other severe acute appendicitis in children combined with white blood cell (WBC) count, neutrophil percentage, and C-reactive protein (CRP). METHODS: A retrospective study enrolled 327 consecutive patients who underwent appendectomy for acute appendicitis (aged 13 days to 14 years) in Qingdao Women & Children's Hospital from Jan 2013 to Dec 2014. WBC count, neutrophil percentage, CRP, and D-dimer levels were measured. Descriptive analyses, Student's t-test, and receiver operating characteristic (ROC) analyses were used to quantify the correlation between D-dimer level and the severity of appendicitis and to evaluate the differential diagnostic value of D-dimer combined with WBC count, neutrophil percentage and CRP between simple and other severe appendicitis. RESULTS: Compared with simple appendicitis, WBC count, neutrophil percentage, CRP, and D-dimer levels were all significantly higher in other severe appendicitis (p < 0.01). Both CRP and D-dimer levels were positively correlated with the severity of disease. In differentiating between simple and other severe appendicitis, CRP (area under the ROC curve (AUC): 0.841) showed the highest sensitivity (80.7%) and the highest negative predictive value (NPV) (60.0%), while D-dimer (AUC: 0.793) showed the highest specificity (90.0%) and the highest positive predictive value (PPV) (94.9%). Combined CRP and D-dimer had a sensitivity, specificity, PPV, NPV, and accuracy of 87.5%, 94.6%, 97.8%, 72.9%, and 89.4%, respectively. CONCLUSIONS: CRP and D-dimer levels are positively correlated with the severity of acute appendicitis in children. Combined CRP and D-dimer are identified as suitable diagnostic markers for differentiating between simple and other severe appendicitis, which will provide important guidance for clinicians to determine the follow-up management of acute appendicitis.


Assuntos
Apendicite/diagnóstico , Proteína C-Reativa/análise , Produtos de Degradação da Fibrina e do Fibrinogênio/análise , Doença Aguda , Adolescente , Biomarcadores/sangue , Criança , Pré-Escolar , Diagnóstico Diferencial , Feminino , Humanos , Lactente , Recém-Nascido , Contagem de Leucócitos , Masculino , Neutrófilos/citologia , Curva ROC , Estudos Retrospectivos , Sensibilidade e Especificidade , Índice de Gravidade de Doença
12.
Chin J Integr Med ; 22(6): 457-66, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26033318

RESUMO

OBJECTIVE: To explore the neuroprotective effects of electroacupuncture (EA) on hypoxic-ischemic encephalopathy (HIE) and to further investigate the role of glial cell line-derived neurotrophic factor (GDNF) family receptor member RET (rearranged during transfection) and its key downstream phosphatidylinositol 3 kinase (PI-3K)/protein kinase B (Akt) pathway in the process. METHODS: A total of 220 seven-day-old SD rats (of either sex, from 22 broods) were randomly divided into two groups, one (30 rats) for sham-surgery group and the other (190 rats) for HIE model group. The HIE model was established using the left common carotid artery ligation method in combination with hypoxic treatment. The successfully established rats were randomly divided into five groups, including control model group, EA group, sham-EA group, antagonist group and antagonist plus electroacupuncture group, with 35 rats in each group. Baihui (GV 20), Dazhui (GV 14), Quchi (LI 11) and Yongquan (KI 1) acupoints were chosen for acupuncture. EA was performed at Baihui and Quchi for 10 min once a day for continuous 1, 3, 7 and 21 days, respectively. The rats were then killed after the operation and injured cerebral cortex was taken for the measurement of neurologic damage by hematoxylin-eosin (HE) staining and the degenerative changes of cortical ultrastructure by transmission electron microscopy. RET mRNA level and Akt protein level were detected by real-time reverse-transcription polymerase chain reaction (RT-PCR) and western blot analysis, respectively. RESULTS: EA could ameliorate neurologic damage of the first somatic sensory area (S1Tr) and alleviate the degenerative changes of ultrastructure of cortical neurons in rats subjected to HIE. And the longer acupuncture treatment lasted, the better its therapeutic effect would be. This was accompanied by gradually increased expression of GDNF family receptor RET at the mRNA level and its downstream signaling Akt at the protein level in the ischemic cortex. CONCLUSION: EA has neuroprotective effects on HIE and could be a potential therapeutic strategy for HIE in the neonate. Activation of RET/Akt signaling pathway might be involved in this process.


Assuntos
Eletroacupuntura , Fator Neurotrófico Derivado de Linhagem de Célula Glial/genética , Hipóxia-Isquemia Encefálica/genética , Hipóxia-Isquemia Encefálica/terapia , Fármacos Neuroprotetores/uso terapêutico , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-ret/genética , Animais , Western Blotting , Córtex Cerebral/patologia , Córtex Cerebral/ultraestrutura , Feminino , Fator Neurotrófico Derivado de Linhagem de Célula Glial/metabolismo , Hipóxia-Isquemia Encefálica/patologia , Masculino , Degeneração Neural/patologia , Neurônios/patologia , Neurônios/ultraestrutura , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteínas Proto-Oncogênicas c-ret/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos Sprague-Dawley , Reação em Cadeia da Polimerase em Tempo Real
13.
Aging Cell ; 13(5): 890-9, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25040736

RESUMO

The inactivation of plasminogen activator inhibitor-1 (PAI-1) has been shown to exert beneficial effects in age-related vascular diseases. Limited information is available on the molecular mechanisms regarding the negatively regulated expression of PAI-1 in the vascular system. In this study, we observed an inverse correlation between SIRT1, a class III histone deacetylase, and PAI-1 expression in human atherosclerotic plaques and the aortas of old mice, suggesting that internal negative regulation exists between SIRT1 and PAI-1. SIRT1 overexpression reversed the increased PAI-1 expression in senescent human umbilical vein endothelial cells (HUVECs) and aortas of old mice, accompanied by decreased SA-ß-gal activity in vitro and improved endothelial function and reduced arterial stiffness in vivo. Moreover, the SIRT1-mediated inhibition of PAI-1 expression exerted an antisenescence effect in HUVECs. Furthermore, we demonstrated that SIRT1 is able to bind to the PAI-1 promoter, resulting in a decrease in the acetylation of histone H4 lysine 16 (H4K16) on the PAI-1 promoter region. Thus, our findings suggest that the SIRT1-mediated epigenetic inhibition of PAI-1 expression exerts a protective effect in vascular endothelial senescence.


Assuntos
Senescência Celular/fisiologia , Inibidor 1 de Ativador de Plasminogênio/genética , Serpina E2/genética , Sirtuína 1/genética , Animais , Regulação para Baixo , Epigênese Genética , Células Endoteliais da Veia Umbilical Humana/metabolismo , Humanos , Masculino , Camundongos , Camundongos Transgênicos , Placa Aterosclerótica/metabolismo , Inibidor 1 de Ativador de Plasminogênio/metabolismo , Serpina E2/metabolismo , Sirtuína 1/metabolismo
14.
PLoS One ; 9(5): e97999, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24859347

RESUMO

SIRT1, a class III histone deacetylase, acts as a negative regulator for many transcription factors, and plays protective roles in inflammation and atherosclerosis. Transcription factor nuclear factor of activated T cells (NFAT) has been previously shown to play pro-inflammatory roles in endothelial cells. Inhibition of NFAT signaling may be an attractive target to regulate inflammation in atherosclerosis. However, whether NFAT transcriptional activity is suppressed by SIRT1 remains unknown. In this study, we found that SIRT1 suppressed NFAT-mediated transcriptional activity. SIRT1 interacted with NFAT, and the NHR and RHR domains of NFAT mediated the interaction with SIRT1. Moreover, we found that SIRT1 primarily deacetylated NFATc3. Adenoviral over-expression of SIRT1 suppressed PMA and calcium ionophore Ionomycin (PMA/Io)-induced COX-2 expression in human umbilical vein endothelial cells (HUVECs), while SIRT1 RNAi reversed the effects in HUVECs. Moreover, inhibition of COX-2 expression by SIRT1 in PMA/Io-treated HUVECs was largely abrogated by inhibiting NFAT activation. Furthermore, SIRT1 inhibited NFAT-induced COX-2 promoter activity, and reduced NFAT binding to the COX-2 promoter in PMA/Io-treated HUVECs. These results suggest that suppression of NFAT transcriptional activity is involved in SIRT1-mediated inhibition of COX-2 expression induced by PMA/Io, and that the negative regulatory mechanisms of NFAT by SIRT1 may contribute to its anti-inflammatory effects in atherosclerosis.


Assuntos
Ciclo-Oxigenase 2/genética , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Ionomicina/farmacologia , Fatores de Transcrição NFATC/metabolismo , Sirtuína 1/metabolismo , Acetato de Tetradecanoilforbol/farmacologia , Transcrição Gênica/efeitos dos fármacos , Acetilação/efeitos dos fármacos , Células HEK293 , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Células Endoteliais da Veia Umbilical Humana/metabolismo , Humanos , Regiões Promotoras Genéticas/genética
15.
Trends Cardiovasc Med ; 23(7): 237-41, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23499302

RESUMO

Accumulating evidence indicates that oxidative stress can occur through overproduction of reactive oxygen species (ROS) and/or reduced anti-oxidant potentials under pathophysiological conditions and plays an important role in the development of cardiovascular diseases (CVDs). Adapter protein p66Shc has the property to directly stimulate mitochondrial ROS generation by an oxidoreductase activity. A growing body of evidence implies that p66Shc plays a critical role in the pathophysiology of age-related vascular diseases. Silent mating type information regulator 2 homolog 1 (SIRT1), a nicotinamide adenine dinucleotide (NAD+)-dependent class III histone deacetylase (HDAC), has also been implicated in protection against vascular aging and age-related vascular diseases. Recently, we demonstrated that SIRT1 protects blood vessels from hyperglycemia-induced endothelial dysfunction through a novel mechanism involving the downregulation of p66Shc expression. In this review, we discuss the cross-talk between these two longevity genes as a mechanism of preventing vascular diseases by involving anti-oxidative stress responses and inhibiting endothelial senescence.


Assuntos
Proteínas Adaptadoras da Sinalização Shc/metabolismo , Sirtuína 1/metabolismo , Animais , Senescência Celular/genética , Regulação para Baixo , Endotélio Vascular/metabolismo , Humanos , Longevidade/genética , Estresse Oxidativo/genética , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais , Proteína 1 de Transformação que Contém Domínio 2 de Homologia de Src , Doenças Vasculares/genética , Doenças Vasculares/metabolismo
16.
Sci China Life Sci ; 56(1): 19-25, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23238746

RESUMO

Intercellular adhesion molecule-1 (ICAM-1) plays an important role in the recruitment of leukocytes to the endothelium, which causes inflammation and initiation of atherosclerosis. We have previously shown that endothelium-specific over-expression of class III deacetylase SIRT1 decreases atherosclerosis. We therefore addressed the hypothesis that SIRT1 suppresses ICAM-1 expression in the endothelial cells. Here, we found that expression of SIRT1 and ICAM-1 was significantly induced by PMA and ionomycin (PMA/Io) in human umbilical vein endothelial cells (HUVECs). Adenovirus-mediated over-expression of SIRT1 significantly inhibited PMA/Io-induced ICAM-1 expression in HUVECs. Knockdown of SIRT1 by RNA interference (RNAi) resulted in increased expression of ICAM-1 in HUVECs. Luciferase report assay showed that over-expression of SIRT1 suppressed ICAM-1 promoter activity both in basic and in PMA/Io-induced conditions. We further found that SIRT1 was involved in transcription complex binding on the ICAM-1 promoter by chromatin immunoprecipitation (ChIP) assays. Furthermore, SIRT1 RNAi increased NF-κB p65 binding ability to the ICAM-1 promoter by ChIP assays. Overall, these data suggests that SIRT1 inhibits ICAM-1 expression in endothelial cells, which may contribute to its anti-atherosclerosis effect.


Assuntos
Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Molécula 1 de Adesão Intercelular/metabolismo , Ionomicina/farmacologia , Sirtuína 1/metabolismo , Acetato de Tetradecanoilforbol/farmacologia , Western Blotting , Células Cultivadas , Imunoprecipitação da Cromatina , Expressão Gênica/genética , Células HEK293 , Células Endoteliais da Veia Umbilical Humana/citologia , Células Endoteliais da Veia Umbilical Humana/metabolismo , Humanos , Molécula 1 de Adesão Intercelular/genética , Luciferases/genética , Luciferases/metabolismo , Regiões Promotoras Genéticas/genética , Ligação Proteica , Interferência de RNA , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Sirtuína 1/genética
17.
Sci China Life Sci ; 55(6): 467-73, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22744176

RESUMO

The rapidly increasing prevalence of diabetes mellitus worldwide is one of the most serious and challenging health problems in the 21st century. Mammalian sirtuin 1 (SIRT1) has been shown to decrease high-glucose-induced endothelial cell senescence in vitro and prevent hyperglycemia-induced vascular dysfunction. However, a role for SIRT1 in prevention of hyperglycemia-induced vascular cell senescence in vivo remains unclear. We used endothelium-specific SIRT1 transgenic (SIRT1-Tg) mice and wild-type (WT) mice to construct a 40-week streptozotocin (STZ)-induced diabetic mouse model. In this mode, 42.9% of wild-type (WT) mice and 38.5% of SIRT1-Tg mice were successfully established as diabetic. Forty weeks of hyperglycemia induced significant vascular cell senescence in aortas of mice, as indicated by upregulation of expression of senescence-associated markers including p53, p21 and plasminogen activator inhibitor-1 (PAI-1). However, SIRT1-Tg diabetic mice displayed dramatically decreased expression of p53, p21 and PAI-1 compared with diabetic WT mice. Moreover, manganese superoxide dismutase expression (MnSOD) was significantly downregulated in the aortas of diabetic WT mice, but was preserved in diabetic SIRT1-Tg mice. Furthermore, expression of the oxidative stress adaptor p66Shc was significantly decreased in aortas of SIRT1-Tg diabetic mice compared with WT diabetic mice. Overall, these findings suggest that SIRT1-mediated inhibition of hyperglycemia-induced vascular cell senescence is mediated at least partly through the reduction of oxidative stress.


Assuntos
Senescência Celular , Células Endoteliais/metabolismo , Hiperglicemia/metabolismo , Sirtuína 1/metabolismo , Animais , Western Blotting , Inibidor de Quinase Dependente de Ciclina p21/metabolismo , Diabetes Mellitus Experimental/genética , Diabetes Mellitus Experimental/metabolismo , Regulação para Baixo , Endotélio Vascular/citologia , Endotélio Vascular/metabolismo , Feminino , Hiperglicemia/genética , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Fosforilação , Inibidor 1 de Ativador de Plasminogênio/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteínas Adaptadoras da Sinalização Shc/metabolismo , Sirtuína 1/genética , Proteína 1 de Transformação que Contém Domínio 2 de Homologia de Src , Superóxido Dismutase/metabolismo , Fatores de Tempo , Proteína Supressora de Tumor p53/metabolismo , Regulação para Cima
18.
Circ Res ; 109(6): 639-48, 2011 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-21778425

RESUMO

RATIONALE: Inactivation of the p66Shc adaptor protein confers resistance to oxidative stress and protects mice from aging-associated vascular diseases. However, there is limited information about the negative regulating mechanisms of p66Shc expression in the vascular system. OBJECTIVE: In this study, we investigated the role of SIRT1, a class III histone deacetylase, in the regulation of p66Shc expression and hyperglycemia-induced endothelial dysfunction. METHODS AND RESULTS: Expressions of p66Shc gene transcript and protein were significantly increased by different kinds of class III histone deacetylase (sirtuin) inhibitors in human umbilical vein endothelial cells and 293A cells. Adenoviral overexpression of SIRT1 inhibited high-glucose-induced p66Shc upregulation in human umbilical vein endothelial cells. Knockdown of SIRT1 increased p66Shc expression and also increased the expression levels of plasminogen activator inhibitor-1 expression, but decreased manganese superoxide dismutase expression in high-glucose conditions. However, knockdown of p66Shc significantly reversed the effects of SIRT1 knockdown. In addition, p66Shc overexpression significantly decreased manganese superoxide dismutase expression and increased plasminogen activator inhibitor-1 expression in high-glucose conditions, which were recovered by SIRT1 overexpression. Moreover, compared to streptozotocin-induced wild-type diabetic mice, endothelium-specific SIRT1 transgenic diabetic mice had decreased p66Shc expression at both the mRNA and the protein levels, improved endothelial function, and reduced accumulation of nitrotyrosine and 8-OHdG (markers of oxidative stress). We further found that SIRT1 was able to bind to the p66Shc promoter (-508 bp to -250 bp), resulting in a decrease in the acetylation of histone H3 bound to the p66Shc promoter region. CONCLUSION: Our findings indicate that repression of p66Shc expression by SIRT1 contributes to the protection of hyperglycemia-induced endothelial dysfunction.


Assuntos
Regulação para Baixo/genética , Endotélio Vascular/metabolismo , Hiperglicemia/genética , Proteínas Adaptadoras da Sinalização Shc/antagonistas & inibidores , Sirtuína 1/fisiologia , Envelhecimento/genética , Animais , Diabetes Mellitus Experimental/genética , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Experimental/patologia , Endotélio Vascular/patologia , Células HEK293 , Humanos , Hiperglicemia/patologia , Hiperglicemia/prevenção & controle , Imunidade Inata/genética , Masculino , Camundongos , Camundongos Transgênicos , Estresse Oxidativo/genética , Estabilidade Proteica , Proteínas Adaptadoras da Sinalização Shc/biossíntese , Proteína 1 de Transformação que Contém Domínio 2 de Homologia de Src
19.
Am J Med Sci ; 336(6): 519-23, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19092329

RESUMO

BACKGROUND: We evaluated the features of neuropathology, abnormal prion protein (PrP) molecules, and clinical data of a Chinese woman diagnosed with familiar Creutzfeldt-Jakob disease (CJD), having 7 octa-repeats inserted with codon 129 methionine homozygote in the PRNP gene. METHODS: Neuropathologic characteristics of the brain were analyzed by hemotoxylin-eosin stain and electronic microscopy. The presence of abnormal PrP in brains was detected by proteinase K and PrP molecules were evaluated by deglycosylation assay. RESULTS: Spongiform degeneration, with diffuse neuronal loss and mild astrocytic gliosis, as well as with profound degeneration of neurons and astrocytes was observed. Proteinase K-resistant PrP was deposited widely in various regions of the brain. Calculation of the glycosylation ratios of proteinase K-resistant PrP molecules identified that the monoglycosyl isomer was predominant. PrP deglycosylation tests allowed for the identification of a predominant 19-kDa PrP signal that represents a partially proteolytic C-terminal segment, a 27-kDa band that represents the full-length wild-type PrP molecule, and a 30-kDa band that probably corresponds to the full-length mutant PrP molecule. CONCLUSION: : Sporadic CJD-like neuropathologic changes and deposits of proteinase K-resistant PrP have been identified in this familiar CJD case with a 168 base pair nucleotide insertion. The clinical features differ from previously reported cases that had 7 octa-repeat insertion, but bear similarities to sporadic CJD.


Assuntos
Síndrome de Creutzfeldt-Jakob , Príons/metabolismo , Córtex Cerebral/química , Córtex Cerebral/patologia , Síndrome de Creutzfeldt-Jakob/genética , Síndrome de Creutzfeldt-Jakob/patologia , Síndrome de Creutzfeldt-Jakob/fisiopatologia , Evolução Fatal , Feminino , Humanos , Príons/genética , Sequências Repetitivas de Ácido Nucleico
20.
Mol Cell Biochem ; 310(1-2): 49-55, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18038270

RESUMO

Microtubule associated protein tau is considered to play roles in some types of human transmissible spongiform encephalopathies (TSE). In this study, the full-length and several truncated human tau proteins were expressed from E. coli and purified. Using GST pull down, co-immunoprecipitation assay and tau-coated ELISA, the molecular interaction between tau protein and PrP was confirmed in the context of the full-length human tau. The N terminus (amino acids 1-91) and tandem repeats region (amino acids 186-283) of tau protein were responsible for the interaction with PrP. The octapeptide repeats within PrP directly affected the binding activity of PrP with tau. GSS-related mutant PrP102L and fCJD- related mutants with two and seven extra octarepeats showed more active binding capacity with tau than wild-type PrP. The molecular interactions between PrP and tau protein highlight a potential role of tau in the biological function of PrP and the pathogenesis of TSE.


Assuntos
Síndrome de Creutzfeldt-Jakob/metabolismo , Doença de Gerstmann-Straussler-Scheinker/metabolismo , Proteínas Mutantes/metabolismo , Proteínas PrPC/metabolismo , Proteínas tau/metabolismo , Linhagem Celular Tumoral , Humanos , Peptídeos/metabolismo , Proteínas PrPC/química , Ligação Proteica , Estrutura Terciária de Proteína , Proteínas Recombinantes de Fusão/metabolismo , Sequências Repetitivas de Aminoácidos , Proteínas tau/química
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