ABSTRACT
Aim To identify alteration in key molecular components related to memory formation and insulin signaling in the hippocampus after rosiglitazone was in-jected into the ob/ob mice to test whether cognitive dysfunction was pharmacologically reversed by regula-tion of rosiglitazone. Methods The age-matched mice were divided into three groups ( n=18 ): Saline-trea-ted WT mice ( WT-Saline);Saline-treated ob/ob mice ( ob/ob-Saline) and RSG-treated ob/ob mice ( ob/ob-RSG) through intraperitoneal injection of rosiglitazone ( RSG) . The random glucose levels were measured for 10 days during the intraperitoneal injection period. No-vel object recognition was performed before mice were sacrificed. Western blot was implemented to evaluate the following proteins: BACE1, p-Tau, p-IRS1,IRS1, p-Akt and Akt in hippocampal tissues. The Aβ1-40 levels were detected by ELISA Kit. Results The random blood glucose levels were significantly re-duced in ob/ob-RSG compared with ob/ob-saline. RSG treatment led to an increase in hippocampus-de-pendent cognition of ob/ob mice according to the novel object recognition. The proteins levels of BACE1, p-Tau and Aβ were lowered in RSG-treated ob/ob mice. Furthermore, RSG treatment up-regulated hippocampal p-IRS1/IRS1 and p-Akt/Akt ratio. Conclusion Ros-iglitazone ameliorates cognitive deficits in ob/ob mice through up-regulating insulin signaling pathways in the hippocampus.
ABSTRACT
Aim To investigate the effect of Jinlida on cholesterol-related genes in skeletal muscle in fat-in-duced insulin resistance ApoE-/ - mice. Methods Ten male C57 BL/6 J mice were selected as normal group ( NF );50 male ApoE-/ - mice with a high-fat feeding after 16 weeks ( HF) were divided into model group, rosiglitazone ( LGLT ) , Jinlida low dose group ( JLDL, 0. 95 g · kg-1 · d-1 ) , Jinlida medium dose group ( JLDM, 1. 9 g·kg-1 ·d-1 ) , Jinlida high dose group (JLDH, 3. 8 g·kg-1·d-1), which were per-formed intragastric administration for 8 weeks. Oil red O staining of mouse skeletal muscle was used for fat ac-cumulation. Insulin receptor ( INSR) , insulin receptor body substrate-1 ( IRS-1 ) , low-density lipoprotein re-ceptor ( LDLR ) , cholesterol sensor ( SCAP ) mRNA and protein expression in mouse skeletal muscle were measured by quantitative reverse transcription PCR ( RT-PCR ) and Western blot. Results Compared with NF group, fasting blood glucose ( FBG) , choles-terol ( TC ) , triglyceride ( TG ) and low density lipo-protein cholesterol ( LDL-C ) of HF mice were signifi-cantly elevated, while high-density lipoprotein ( HDL-C ) significantly decreased ( P < 0. 05 ) . Compared with HF group, Jinlida group could reduce to varying degrees FBG, TC, TG and LDL-C in mice, and in-crease HDL-C ( P <0. 05 ) . Jinlida could downgrade fasting serum insulin ( FINS ) level, and improve the insulin sensitive index ( ISI ) ( P < 0. 05 ) . Jinlida could obviously improve skeletal muscle fat accumula-tion of mice. Compared with NF group, skeletal mus-cle INSR, IRS-1, LDLR mRNA and protein levels of HF group were significantly decreased ( P <0. 05 ) , while SCAP mRNA and protein level increased signifi-cantly (P<0. 05). Compared with HF group, Jinlida could increase to varying degrees INSR, IRS-1, LDLR mRNA and protein levels ( P < 0. 05 ) , and lower SCAP mRNA and protein levels ( P<0. 05 ) . Conclu-sion Jinlida can alleviate fat-induced insulin resist-ance in ApoE-/ - mice through regulation of cholester-ol-related gene expression.