• Ghrelin对糖尿病大鼠海马DKK-1表达和学习记忆功能的影响

    Subjects: Medicine, Pharmacy >> Preclinical Medicine submitted time 2017-12-27 Cooperative journals: 《南方医科大学学报》

    Abstract: Objective To explore the effects of ghrelin on learning and memory abilities and expressions of DKK-1 and β-catenin in the hippocampus of diabetic rats. Methods Sixty male SD rats were randomly assigned into 4 groups, namely the control group, diabetic group, ghrelin-treated diabetic group (DM1 group), and ghrelin- and D-lys3-GHRP-6 (a GHSR-1a receptor antagonist)-treated diabetic group (DM2 group). Diabetic rat models were established by a single intraperitoneal injection of streptozotocin (65 mg/kg). The learning and memory abilities of the rats were assessed with Morris water maze (MWM) test. The ultrastructure of the hippocampal CA1 area of the rats were observed with electron microscopy. Serum levels of DKK-1 were examined by ELISA, and the expressions of DKK-1 and β-catenin in the hippocampus were examined by quantitative real-time PCR and Western blotting. Results Compared with the control group, the diabetic rats exhibited significantly impaired learning and memory abilities (P<0.05), increased expression of DKK-1 and lowered β-catenin expression in the hippocampus (P<0.05), significant ultrastructural injuries and disordered arrangement of neurons with the nuclear pycnosis in the hippocampal CA1 area. Ghrelin treatment of the diabetic rats obviously improved their learning and memory abilities (P<0.05), reduced DKK-1 and increased β-catenin expressions (P<0.05), ameliorated ultrastructural damages in the hippocampal CA1 area and restored normal neuronal alignment with clear cell layers. Such effects of ghrelin were antagonized by treatment with D-lys3-GHRP-6 in the diabetic rats. Conclusion Ghrelin can alleviate learning and memory dysfunction in diabetic rats possibly by down-regulating the expressions of DKK-1 and activating the WNT signaling pathways.

  • 下调RbAp48 表达可抑制人宫颈癌MS751细胞株的迁移侵袭能力

    Subjects: Medicine, Pharmacy >> Preclinical Medicine submitted time 2017-12-07 Cooperative journals: 《南方医科大学学报》

    Abstract: Objective To investigate the effect of RbAp48 knockdown on the migration and invasion of human cervical cancer cells and explore the mechanism. Methods A small interference RNA (siRNA) was used to knock down the expression of RbAp48 in MS751 cells. The changes in cell migration and invasion were evaluated using wound healing assay and Transwell assay, respectively, and the expressions of RbAp48, vimentin, N-cadherin, E-cadherin, Snail, Twist, MMP-2 and TIMP-2 were determined with Western blotting. Results After siRNA-mediated RbAp48 knockdown, MS751 cells showed a significantly reduced expression of RbAp48 with significantly suppressed cell migration and invasion (P<0.01). RbAp48 knockdown induced obvious down-regulation of the expressions of interstitial cell phenotype proteins vimentin, N-cadherin, and MMP-2 and up-regulation of epithelial cell phenotype proteins E-cadherin and TIMP-2, suggesting the inhibition of epithelial- mesenchymal transition of the cells. The expressions of Snail and Twist were significantly down-regulated in the cells following RbAp48 knockdown. Conclusion Knockdown of RbAp48 can significantly inhibit epithelial-mesenchymal transition and suppress the migration and invasion of cervical cancer cell line MS751, the mechanism of which may involve the down-regulation of Snail and Twist expressions.