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1.
Journal of Environmental and Occupational Medicine ; (12): 196-201, 2023.
Artigo em Chinês | WPRIM | ID: wpr-964933

RESUMO

Background Lead is widely distributed. Lead exposure interferes with early life development in zebrafish, but the mechanisms by which lead exposure affects skeletal development and cardiac development are not clear as yet. Objective To investigate the molecular mechanisms of bone development and cardiac development toxicity induced by lead acetate exposure. Methods Zebrafish embryos were exposed to different concentrations of lead acetate (0, 6, 12, 24, and 48 μmol·L−1) for 3 h post-fertilization (3 hpf) until 5 d post-fertilization (5 dpf). The malformation phenotypes of 5 dpf were counted, and the mRNA expressions of spinal development-related genes (bmp2b, bmp4, bmp9, runx2a, runx2b) and heart development-related genes (nkx2.5, myh6, myh7) were detected by quantitative PCR (qPCR). Expressions of genes of development-related regulatory pathways including Wnt/β-catenin pathway (wnt5a, wnt8a, wnt10a, β-catenin) and TGF-β pathway (tgf-β1, tgf-β2) as well as key molecule eph of Eph-Ephrin signaling were analyzed. Results At 5 dpf, the zebrafish in the lead acetate treated groups showed deformed phenotypes including spinal curvature and pericardial sac edema compared to the control group. In the lead acetate groups at 24 and 48 μmol·L−1, the spinal curvature deformity rates reached 26.47% and 71.52% (P<0.01) respectively. The qPCR results revealed that the expression levels of spinal development-related genes bmp2b, bmp4, bmp9, runx2a, and runx2b were downregulated in the 48 μmol·L−1 exposure group compared to the control group by 82.8%, 58.0%, 88.7%, 85.5%, and 69.2%, respectively (P<0.05 or P<0.01); the expression levels of heart development-related genes myh6, myh7, and nkx2.5 were down-regulated by 63.7%, 58.9%, and 55.2%, respectively (P<0.01); the expression levels of wnt8a and β-catenin in the Wnt/β-catenin pathway were down-regulated by 71.5% and 47.3% (P < 0.05 or P < 0.01), respectively; the expression level of tgf- β1 in the TGF-β pathway was down-regulated by 67.5% (P<0.01); the expression level of eph was down-regulated by 86.9% (P<0.01). Conclusion Lead acetate exerts developmental toxic effects on zebrafish heart and bone by down-regulating the expressions of genes related to spinal development and heart development, as well as inhibiting development-related Wnt/β-catenin and TGF-β pathways and Eph-Ephrin signaling, causing malformed phenotypes such as spinal curvature and pericardial sac edema.

2.
Chinese Journal of Biochemistry and Molecular Biology ; (12): 892-898, 2022.
Artigo em Chinês | WPRIM | ID: wpr-1015676

RESUMO

The erythropoietin-producing hepatocellular receptor (Eph receptor) family is the largest subfamily in the receptor tyrosine kinase (RTK) families which mediates cell morphology, adhesion, movement, proliferation, survival, and differentiation by its bidirectional signals coupled with Ephrin ligands. EphA2 receptor is an important isoform which is involved in the pathological changes in cataract, breast cancer, etc. Previous studies found that the kinase domain of the EphA2 receptor binds to the plasma membrane, and its kinase activity is regulated by the plasma membrane. However, it is still unclear that the impact of the adjacent SAM domain on the membrane binding and kinase activities of kinase domain. In this study we purified the cytoplasmic kinase-SAM tandem of the EphA2 receptor by co-expression with the phosphatase PTP1B 1-301 fragment. Our results showed that the SAM domain of EphA2 receptor can further enhance the interaction between the kinase domain and liposomes (4 mg/mL) by 6 folds (P<0. 001). And the phosphorylation of kinase-SAM tandem can enhance its lipid (4 mg/mL) binding ability by 2. 5 folds (P < 0. 05). In addition, the lipid binding ability and tyrosine phosphorylation activities of kinase domain are mutual promoted, which creating a positive feedback loop in the two biological processes. In conclusion, our studies indicate that the kinase domain and the adjacent SAM domain can function as an intact unit, whose lipid binding ability and kinase activity are quite different from the individual kinase domain. Therefore, our results provide a biochemical basis for better understanding of the regulation mechanism of other Eph receptors in its kinase domain.

3.
Chinese Journal of Clinical Oncology ; (24): 741-746, 2021.
Artigo em Chinês | WPRIM | ID: wpr-861647

RESUMO

The erythropoietin-producing hepatocellular receptor (Eph) and its ligand ephrin are the largest of the receptor tyrosine kinases (RTKs) family in humans. Since ephrin ligands and Eph receptors are membrane-bound proteins, binding and activation of Eph/ephrin intracellular signaling pathways can only occur via direct cell-cell interaction. Eph-ephrin complexes emanate bidirectional signals that affect cells expressing Eph and ephrin, respectively. Its repulsive signaling effects include retraction, which plays an important role in many physiological and pathological processes. EphA2 has been found to have a strong association with tumors and is most widely studied. EphA2 signal transduction in tumor cells may promote or inhibit tumor, depending on the tumor microenvironment. EphA2 "canonical" signaling involves ligand binding and kinase activity; thus EphA2 "noncanonical" signaling is ligand independent and lacks kinase activity. This review summarizes the pathogenesis of EphA2 in nasopharyngeal carcinoma (NPC), including ligand independent signal and EBV infection receptor, furthermore evaluates the prospect of its potential utilization as a target for cancer therapeutics. This may provide a new method for the prevention and treatment of NPC.

4.
Chinese Journal of Neonatology ; (6): 214-218, 2018.
Artigo em Chinês | WPRIM | ID: wpr-699294

RESUMO

Objective To investigate the pathogenesis of white matter damage (WMD) and the effects of xenon intervention on the expression of EphB4 and EphrinB2 mRNA in the brain tissue of neonatal rats.Method Three-day-old SD rat pups (n =96) were randomly assigned into sham group (n =24),model group (n =24),xenon intervention group 1 (n =24) and xenon intervention group 2 (n =24).The WMD model was established by injected of lipopolysaccharide (LPS) 0.05 mg/kg combined with ligation of the right carotid artery for 1 h in the last three groups.Rats in xenon intervention group 1 inhaled 50% xenon immediately for 3 h after modeling,while rats in xenon intervention group 2 inhaled 50% xenon for 3 h at 2 h after modeling.After the completion of xenon intervention,6 rat pups in each groups were sacrificed at 0 h,24 h,48 h and 72 h.The pathologic examination of periventricular tissue was conducted with hematoxylin-eosin staining (HE) and the expression of EphB4 and EphrinB2 mRNA was assayed by real-time quantitative polymerase chain reaction (RT-PCR).Statistical analysis was then performed.Result (1)The structure of white matter in model group became loose,band net-like,with significant nucleus pyknosis.The pathological damages in xenon intervention group 1 and 2 were lighter at 24 h,48 h and 72 h than model group,with less karyopycnosis.(2) Compared with the sham group,the expressions of EphB4 and EphrinB2 mRNA at 0 h,24 h,48 h and 72 h were significantly higher in the model group and xenon intervention group 1 and 2 (P < 0.05),except for the EphB4 mRNA in xenon intervention group 1 at 72 h (P > 0.05).The expressions of EphB4 and EphrinB2 mRNA at each time point in xenon intervention group 1 and 2 were decreased significantly than the model group (P < 0.05),except for the EphB4 mRNA in xenon intervention group 2 at 72 h (P > 0.05).However,there was no statistically significant difference on EphB4 and EphrinB2 mRNA between two xenon intervention groups at each time point (P > 0.05).Conclusion The expression of EphB4 and EphrinB2 mRNA are appreciably increased in brain tissue of neonatal rats with WMD,which indicates the reactive angiogenesis.The intervention with xenon may play a neuroprotective role through reducing the expressions of EphB4/EphrinB2 mRNA and angiogenesis,and early intervention may be better.

5.
Practical Oncology Journal ; (6): 164-168, 2018.
Artigo em Chinês | WPRIM | ID: wpr-697925

RESUMO

The Eph receptors and their ligand Ephrins are closely associated with angiogenesis,cell migration,neuronal local-ization and embryonic development.More and more studies have shown that the Eph receptor and Ephrins are involved in the occur-rence and development of various cancers.In this article,we will focus on the Eph receptor family involved in the formation and devel-opment of lung cancer and metastasis,drug resistance and other mechanisms as well as their potential as targeted therapy of lung canc-er.

6.
Chinese Journal of Pathophysiology ; (12): 2188-2194, 2017.
Artigo em Chinês | WPRIM | ID: wpr-663631

RESUMO

AIM:To investigate the effect of Eph receptor A2 (EphA2) on drug resistance of colorectal carci-noma cells and its possible mechanisms .METHODS:Real-time PCR and Western blot were used to detect the expression of EphA2 at mRNA and protein levels in LoVo and LoVo/5-FU cells.EphA2 siRNA was transfected to down-regulate the EphA2 expression in LoVo/5-FU cells, and the drug sensitivity was calculated by CCK-8 assay.Meanwhile, cell migration and invasion were measured by wound healing assay and Transwell assay , and the protein levels of E-cadherin,β-catenin, N-cadherin, vimentin, Notch and Snail were determined by Western blot .RESULTS: The expression of EphA2 at both mRNA and protein levels was significantly up-regulated in LoVo/5-FU cells (P<0.05).Knockdown of EphA2 suppressed the cell viability, and migration and invasion abilities , but promoted drug sensitivity of LoVo/5-FU cells.Up-regulation of E-cadherin and β-catenin, and down-regulation of N-cadherin and vimentin were observed , indicating that the epithelial-mesenchymal transition ( EMT) process was suppressed .Knockdown of EphA2 decreased the expression levels of Notch and Snail.CONCLUSION:Down-regulation of EphA2 partly reverses drug resistance of LoVo/5-FU cells.The mechanism may be related to suppressing cell growth , migration, invasion and EMT process via Notch/Snail signaling pathway .

7.
Chinese Journal of Behavioral Medicine and Brain Science ; (12): 1053-1056, 2015.
Artigo em Chinês | WPRIM | ID: wpr-488373

RESUMO

Objective Recent researches indicate that Eph/ephrin signaling pathway is possibly related to adult neurogenesis after cerebral injury..With brief introduction of their structures and interactions,the review focus on their possible mechanism in adult neurogenesis.Methods The literatures between 2010 and 2015 were retrieved following online databases:PUBMED,ScienceDirect,Wanfang and CNKI database.The key words used in the reasearch were Eph,ephrin,cerebral injury,adult neurogenesisand so on.Results Totally 42 related articles were enrolled.And these papers discribed how researchers performed their experiments and further explained Eph/ephrin 's vital roles in adult neurogenesis.Conclusion Eph/ephrin signaling can influence adult neurogenesis after cerebral injury.positively or negatively.And Akt may be a downstream signaling molecule of Eph/ephrin that change the progress of adult neurogenesis.However,the detailed mechanisms remain to be further study.

8.
Chinese Journal of Primary Medicine and Pharmacy ; (12): 223-225, 2014.
Artigo em Chinês | WPRIM | ID: wpr-445274

RESUMO

Objective To explore the effect of fluticasone propionate nasal spray(Fu Shu-liang) in improving children's symptoms of allergic rhinitis and recurrent asthma.Methods 100 children with allergic rhinitis and asthma syndrome were randomly divided into control group and experimental group.The control group was treated with loratadine.The experimental group was treated with water-soluble auxiliary Fu Shu-liang nasal spay on the basis of the control group.The treatment effects were observed.Results The total effective rate of the observation group was 94%,which was significantly higher than 76% of the control group (x2 =6.35,P < 0.05).After 10-12 weeks,the rhinitis symptom score and asthma symptom score between the two groups had statistically significant differences (t =2.47,2.64,3.41 ; 2.30,3.17,2.47,all P < 0.05).The incidence rate of adverse reactions such as nasal dryness,epistaxis between the two groups had statistically significant differences (x2 =7.11,7.53,all P < 0.05).Conclusion Fu Shu-liang(Eph propionate and fluticasone propionate nasal spray) has good effect in improving symptoms of children with allergic rhinitis and asthma,it is worthy of clinical vigorously promoted.

9.
Arq. bras. cardiol ; 99(6): 1082-1091, dez. 2012. ilus, graf, tab
Artigo em Português | LILACS | ID: lil-662371

RESUMO

FUNDAMENTO: O Imatinib é um inibidor do receptor tirosina-quinase que foi confirmada como exercendo um efeito inibidor sobre a atividade do receptor do PDGF, fator de crescimento plaquetário (PDGFRα e PDGFRβ). OBJETIVO: Investigar o efeito protetor do Imatinib na fibrose miocárdica em acetato de deoxicorticosterona (DOCA)/ratos com hipertensão induzida por sal. MÉTODOS: Sessenta ratos Sprague-Dawley machos, uninefrectomizados foram distribuídos em três grupos: ratos controles (grupo CON): grupo deoxicorticosterona (grupo DOCA); grupo deoxicorticosterona e Imatinib (grupo DOCA IMA). A Pressão Arterial Sistólica (PAS) foi medida quinzenalmente. Foi estudada a porção apical do ventrículo esquerdo. Foram empregados: coloração vermelho sirius, coloração de hematoxilina-eosina, imuno-histoquímica e ensaio de western blot. RESULTADOS: A PAS nos grupos DOCA e IMA+DOCA foi maior que no grupo CON nos dias 14 e 28. Os animais do grupo DOCA apresentaram fibrose intersticial e perivascular grave no dia 28, e as expressões de PI, PIII, tenascina-C e fibronectina foram significativamente maiores que nos grupos DOCA+IMA e CON. Quando comparados com o grupo CON, os grupos DOCA e DOCA+IMA apresentaram resposta inflamatória de tecido miocárdico e infiltração de monócitos/macrófagos de diferentes graus. As expressões proteicas do PDGF-A, PDGF-C e PDGFRα foram significativamente maiores nos grupos DOCA e DOCA+IMA que no grupo CON, mas a expressão proteica do p-PDGFRα no grupo DOCA+IMA foi menor que no DOCA. CONCLUSÃO: O Imatinib pode exercer efeitos inibitórios sobre a fibrose miocárdica em ratos com hipertensão induzida por DOCA/sal, os quais podem ser atribuídos à inibição da atividade do PDGFR-α.


BACKGROUND: Imatinib is a tyrosine kinase receptor inhibitor that has been confirmed to exert inhibitory effect on the platelet derived growth factor PDGF receptor (PDGFRα and PDGFRβ) activity. OBJECTIVE: To investigate the protective effect of imatinib on the myocardial fibrosis in deoxycorticosterone-acetate (DOCA)/salt induced hypertensive rats. METHODS: Sixty male uninephrectomized Sprague-Dawley rats were assigned to three groups: control rats (CON group); deoxycorticosterone group (DOCA group); deoxycorticosterone and imatinib group (DOCA+IMA group). Systolic blood pressure (SBP) was measured biweekly. The apical portion of the left ventricle was studied. Sirius-Red staining, Hematoxylin-Eosin staining, immunohistochemistry and Western blot assay were employed. RESULTS: SBP in the DOCA group and DOCA+IMA group was higher than that in the CON group on day 14 and 28. Animals in the DOCA group showed severe interstitial and perivascular fibrosis on day 28, and the expressions of PI, PIII, tenascin-C and fibronectin were significantly higher than those in the DOCA+IMA group and CON group. When compared with the CON group, myocardial tissue inflammatory response and monocyte/macrophage infiltration of different degrees were observed in the DOCA group and DOCA+IMA group. Protein expressions of PDGF-A, PDGF-C and PDGFRα were signiflcantly higher in the DOCA and DOCA+IMA groups than those in the CON group, but the p-PDGFRα protein expression in the DOCA+IMA group was lower than that in the DOCA group. CONCLUSION: Imatinib can exert inhibitory effects on myocardial fibrosis in DOCA/salt induced hypertensive rats, which may be attributed to the inhibition of PDGFR-α activity.


Assuntos
Animais , Masculino , Ratos , Benzamidas/farmacologia , Fibrose Endomiocárdica/tratamento farmacológico , Piperazinas/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Pirimidinas/farmacologia , Receptor alfa de Fator de Crescimento Derivado de Plaquetas/antagonistas & inibidores , Western Blotting , Benzamidas/uso terapêutico , Pressão Sanguínea/efeitos dos fármacos , Desoxicorticosterona , Modelos Animais de Doenças , Fibrose Endomiocárdica/patologia , Fibronectinas/análise , Fibronectinas/metabolismo , Fibrose/tratamento farmacológico , Fibrose/patologia , Hipertensão/induzido quimicamente , Hipertensão/fisiopatologia , Nefrectomia/métodos , Piperazinas/uso terapêutico , Inibidores de Proteínas Quinases/uso terapêutico , Pirimidinas/uso terapêutico , Ratos Sprague-Dawley , Receptor alfa de Fator de Crescimento Derivado de Plaquetas/metabolismo , Receptor beta de Fator de Crescimento Derivado de Plaquetas/antagonistas & inibidores , Receptor beta de Fator de Crescimento Derivado de Plaquetas/metabolismo , Resultado do Tratamento , Tenascina/análise , Tenascina/metabolismo
10.
Chinese Journal of Anesthesiology ; (12): 345-348, 2012.
Artigo em Chinês | WPRIM | ID: wpr-426304

RESUMO

Objective To investigate the role of phosphatidylinositol 3-kinase (PI3K)/protein-serine-threonine kinases(Akt) signal transduction pathway in EphB receptor-mediated neuropathic pain in rats.Methods Forty-eight pathogen-free male SD rats aged 2-3 months weighing 150-180 g were randomly divided into 6 groups (n =8 each):groups sham operation (groups S1 and S2 ); groups chronic constrictive injury (CCI) (groups C1and C2 ) and groups EphBI-Fc (EphB receptor antagonist) + CCI (groups E1 and E2 ).Neuropathic pain was induced by placing 4 ligatures on left sciatic nerve at 1 mm intervals with 5-0 silk thread in groups C1,C2,E1 and E2.EphBI-Fc 0.5 μg in 5 μl normal saline was injected intrathecally 1 h before operation and at 1 and 2 d after operation (group E1 ) or on 5th day after operation (group E2).Normal saline 5 μl was injected intrathecally instead of EphBI-Fc 1 h before operation and at 1 and 2 days after operation (groups S1 and C1 ) or on 5th day after operation (groups S2 and C2 ).Pain withdrawal latency to noxious thermal stimulation (PWL) and pain withdrawal threshold to noxious mechanical stimulation (PWT) were measured before operation and at 1,3 and 5 d after operation.The animals were sacrificed at 5 d after operation after measurement of pain threshold.The lumbar segment of spinal cord (L4-6) was removed for determination of c-Fos,PI3K and phosphorylated Akt(p-Akt) expression.Results CCI significantly reduced PWL and PWT and up-regulated spinal c-Fos,PI3K and p-Akt expression in groups C1 and C2 as compared with groups S1 and S2.EphB1-Fc significantly decreased hyperalgesia and the upregulated spinal Fos,PI3K and p-Akt protein expression induced by CCI in groups E1 and E2 as compared with groups C1 and C2.Conclusion Spinal EphB receptor is involved in the development and maintenance of neuropathic pain through PI3K/Akt signal transduction pathway.

11.
Chinese Journal of Primary Medicine and Pharmacy ; (12): 1067-1069, 2008.
Artigo em Chinês | WPRIM | ID: wpr-399555

RESUMO

Objective To explore the relationship of the expression, regulation and adhesion of PTA1 in pregnancy induced hypertension(PIH). Methods The expression,regulation and adhesion of PTA1 on vascular en- dothelial cells incubated by sera from 10 PIH patients and 10 normal pregnant women repectively was detected by flow cytometry. Results The positive rate of PTA1 15.51% (24h) and 6.32 % (48h) in PIH group is significantly higher than that 7.81% (24h) and 4.72 % (48h) in normal pregnant woman group( P < 0.01 ). After the incubation with platelets,the positive rate of PTA1 6.64% (24h) and 4.13% (48h) in PIH group is lower than before(P< 0.05). The PTA1 expression 8.11% (24h) and 4.28% (48h) in PIH group is much lower after blocking with PTA1/IgG than that before(P < 0.01 ). Conclusion There are some abnormal stimulated factors in PIH patients, which activate vascular endothelial cells. PTA1 plays an important role in the adhesion of platelets to vascular en- dothelial cells, PTA1 is closely related to the progress of PIH which indicates that PTA1 directly or indirectly takes part in the pathophysiologic consequences of PIH.

12.
Genomics & Informatics ; : 192-201, 2008.
Artigo em Inglês | WPRIM | ID: wpr-203274

RESUMO

Erythropoietin-producing human hepatocellular carcinoma receptor B1 (EPHB1) is a member of the Eph family of receptor tyrosine kinases that mediate vascular system development. Eph receptor overexpression has been observed in various cancers and is related to the malignant transformation, metastasis, and differentiation of cancers, including hepatocellular carcinoma (HCC). Eph receptors regulate cell migration and attachment to the extracellular matrix by modulating integrin activity. EphrinB1, the ligand of EPHB1, has been shown to regulate HCC carcinogenesis. Here, we sought to determine whether EPHB1 polymorphisms are associated with hepatitis B virus (HBV)-infected liver diseases, including chronic liver disease (CLD) and HCC. We genotyped 26 EPHB1 single nucleotide polymorphisms (SNPs) in 399 Korean CLD, HCC, and LD (CLD+HCC) cases and seroconverted controls (HBV clearance, CLE) using the GoldenGate assay. Two SNPs (rs6793828 and rs11717042) and 1 haplotype that were composed of these SNPs were associated with an increased risk for CLD, HCC, and LD (CLD+HCC) compared with CLE. Haplotypes that could be associated with HBV-infected liver diseases by affecting downstream signaling were located in the Eph tyrosine kinase domain of EPHB1. Therefore, we suggest that EPHB1 SNPs, haplotypes, and diplotypes may be genetic markers for the progression of HBV-associated acute hepatitis to CLD and HCC.


Assuntos
Humanos , Carcinoma Hepatocelular , Movimento Celular , Matriz Extracelular , Marcadores Genéticos , Haplótipos , Hepatite , Vírus da Hepatite B , Fígado , Hepatopatias , Metástase Neoplásica , Fosfotransferases , Polimorfismo de Nucleotídeo Único , Proteínas Tirosina Quinases , Receptor EphA1 , Receptores da Família Eph , Tirosina
13.
Progress in Biochemistry and Biophysics ; (12)2006.
Artigo em Chinês | WPRIM | ID: wpr-595850

RESUMO

Osteoclastic bone resorption and osteoblastic bone formation are coordinated as a coupled mechanism to effect the development of bone and to maintain bone homeostasis. Recently reported Eph/ephrin bidirectional signaling between osteoclasts and osteoblasts plays a pivol role in bone homeostasis and casts new light on coupling of bone resorption and bone formation, which is gaining more and more attention in researches of bone biology and bone diseases. The present article aims to address the researches on the Eph/ephrin bidirectional signaling between osteoblasts and osteoclasts with molecular constitution, mechanism of the signal transduction, biological significance and so on.

14.
Journal of the Korean Gastric Cancer Association ; : 25-30, 2006.
Artigo em Coreano | WPRIM | ID: wpr-178387

RESUMO

PURPOSE: The EphB2 receptor, a member of the receptor tyrosine kinase family, is a target gene of the Wnt signaling pathway and may achieve a tumor suppressor function through regulation of cell growth and migration. Our aim was to determine whether an altered expression of EphB2 might be associated with gastric cancer development and, if so, to determine to which pathologic parameter it is linked. MATERIALS AND METHODS: For the construction of the gastric cancer tissue microarray, 83 paraffin-embedded tissues containing gastric cancer areas were cored 3 times and transferred to the recipient master block. The expression patterns of EphB2 were examined on tissue microarray slides by using immunohistochemistry and were compared using pathologic parameters, including histological type, depth of invasion, lymph node metastatsis, and peritoneal dissemination. RESULTS: The EphB2 protein was expressed in the normal gastric mucosal epithelium, especially in the bottom of the mucosa. We found loss of EphB2 expression in 30 (36.1%) of the 83 gastric cancer tissues. Statistically, loss of EphB2 expression was more common in gastric cancer with lymph-node metastasis. There was no significant correlation between EphB2 expression and depth of invasion, histologic type, or peritoneal dissemination. CONCLUSION: Our findings suggest that loss of EphB2 expression may represent a critical step in gastric carcinogenesis.


Assuntos
Humanos , Carcinogênese , Epitélio , Genes Supressores de Tumor , Imuno-Histoquímica , Linfonodos , Mucosa , Metástase Neoplásica , Proteínas Tirosina Quinases , Receptor EphB2 , Neoplasias Gástricas , Via de Sinalização Wnt
15.
Progress in Biochemistry and Biophysics ; (12)2006.
Artigo em Chinês | WPRIM | ID: wpr-590291

RESUMO

Bidirectional signal transduction is a newly elucidated mechanism in intercellular communication. The bidirectional signal transduction mediated by the Eph-ephrin is an important representative in this field. The Eph family receptor tyrosine kinases and their membrane-bound ligands, the ephrins, play pivotal roles in the development of nervous system, angiogenesis, etc. The signal transduction into cells by Eph receptors is the forward signal, whereas the signal transduction by ephrins is the reverse signal. Based on their molecular structures, the ephrins can be divided into two subclasses, i.e. ephrinA and ephrinB. The ephrinBs are transmembrane proteins, which can activate FAK, JNK and Wnt signal transduction pathways through phosphotyrosine-dependent signaling and PDZ-binding motif-dependent signaling. The ephrinAs are glycosylphosphotidylinositol (GPI) anchored proteins, which can also mediate reverse signal transduction.

16.
Journal of Medical Postgraduates ; (12)2003.
Artigo em Chinês | WPRIM | ID: wpr-587586

RESUMO

Eph,the largest subfamily of tyrosine kinase receptor, could be divided into two groups,EphA and EphB.Ephs play a role in the embryonic development and differentiation of the nervous and vascular systems. In recent years,a large number of ephrins and Ephs had been found to be overexpressed in numerous human tumors,and have relation to development and prognosis of cancers.Down-regulated of EphA3 and EphA7 in cancers,was attributed to the hypermethylaiton of CpG island in promoter region.

17.
Journal of Medical Postgraduates ; (12)2003.
Artigo em Chinês | WPRIM | ID: wpr-591203

RESUMO

EphA1,the first member of the Eph receptor tyrosine kinase family,not only plays a pivotal role in embryonic development and angiogenesis,but also expresses in some types of adult human tissues.Its specific characteristics of Eph/ephrin binding and the Eph/ephrin signaling transduction are fundamentally involved in tumor initiation,progression and metastasis.The expression levels of EphA1 vary considerably in different types of normal tissues and tumors,or even in different phases of tumor development,suggestive of its functional pluralism.Intensive studies of EphA1 on angiogenesis,carcinogenesis and metastasis may provide a method for the early diagnosis and a potential target for the treatment of cancers.

18.
Chinese Journal of Ultrasonography ; (12): 333-335, 1999.
Artigo em Chinês | WPRIM | ID: wpr-400479

RESUMO

Objective To evaluate the value of Doppler indices of intrarenal artery (IRA) in clinicobservation in pregnancy induced hypertension(PIH).MethodsForty-six cases of PIH underwent Doppler measurment of PI,RI in IRA,and 186 normotensive pregnant women were measured as control.Results ①There was a larger increase of IRAPI and IRARI in PIH than in normal prgnant(P<0.001),and IRAPI is significantly higher in moderate and severe PIHs than in mild PIH(P<0.001),②IRAPI,IRARI correlate positively with classification of PIH(P<0.001),proteinuria(P<0.001)and MAP(P<0.05),and IRAPI is the best one.Conclusions It is of a certain significance to the clinical observation and treatment of PIH by using color Doppler to examine the indices of IRA in the pregnant women with PIH.

19.
Chinese Journal of Ocular Fundus Diseases ; (6)1996.
Artigo em Chinês | WPRIM | ID: wpr-521876

RESUMO

Objective To explore the effect of endothelin (ET)、nitric oxide (NO) in plasma on retinopathy in the pregnancy-induced hypertension (PIH). Methods The level of ET and NO in plasma of 75 cases of in-patient women with PIH and 20 cases of women with the full terms and normal pregnancy before and after delivery was determined by radioimmunoassay. The retinopathy of the patients with PIH before and after delivery was detected by appointed doctor. The levels of ET and NO in both groups were compared and the relationship between ET and NO in plasma and the retinopathy before and after the delivery was detected. Results The levels of ET [(145.00?54.41) ng/L] in serious PIH patients were much higher than that in the control [(81.50?43.80) ng/L], the minor [(85.30?33.33) ng/L] and middling PIH group [(90.20?39.25) ng/L]. The levels of ET in plasma before and after pregnancy were not changed in PIH patients [(118.70?33.44) ng/L], but were higher than that in the control group. The levels of plasma NO in serious [(87.56?35.58) ng/L] and middling [(78.11?28.96) ng/L] PIH group were both higher than that in the control group [(46.70?32.64) ng/L], and the levels in minor[(52.56?28.35) ng/L] and middling PIH group were lower than that in the serious PIH group. The level of NO in plasma of PIH patients after the delivery was much lower than that before the delivery, while higher than that in the control. The positive correlation between levels of ET and NO and retinopathy was found in PIH patients. Conclusions The levels of plasma ET and NO in PIH patients are related to the extent of the disease, and the level of ET in plasma is highly related to the retinopathy in PIH patients. ET and NO might be played an important role in pathogenesis of retinopathy and ET might be a good index in reflecting the rank of retinopathy in PIH.

20.
Chinese Pharmacological Bulletin ; (12)1987.
Artigo em Chinês | WPRIM | ID: wpr-556140

RESUMO

In recent years, the importance of tyrosine phosphorylation in the nervous system of mammalian is gaining recognition. Tyros ine protein kinases exert important modulatory effect on the proliferation, diff erentiation, migration and metabolism-related singal transduction pathways in c ells. In this paper we reviewed the signal cascade process of three different ty rosine protein kinase families, including Trk, Src and Eph tyrosine protein kina se families. Furthermore, we discussed important role and possible mechanisms of these tyrosine protein kinases on the neuron synapse plasticity and learning an d memory process.

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