Effects of xenon on the expression of EphB4 and EphrinB2 mRNA in neonatal rats with white matter damage / 中国新生儿科杂志

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.

Imatinib atenua a fibrose miocárdica em associação com a inibição da atividade do PDGFRα / Imatinib attenuates myocardial fibrosis in association with inhibition of the PDGFRα activity

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.

Role of phosphatidylinositol 3-kinase/protein-serine-threonine kinases signal transduction pathway in EphB receptor-mediated neuropathic pain in rats / 中华麻醉学杂志

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.