Hepcidin in non-alcoholic fatty liver disease regulated by the TLR4/NF-κB signaling pathway

The aim of our study was to analyze the role of toll-like receptor 4 (TLR4)/nuclear factor (NF)-κB signal pathway on Hepcidin regulation in non-alcoholic fatty liver disease (NAFLD). A total of 60 male Sprague-Dawley rats were randomly divided into the control, NAFLD and intervention groups. Rats in the control group were fed with standard laboratory diet, and rats in the NAFLD and intervention groups were fed with a high-fat diet. A final volume of 2 ml of pathenolide (10 µmol/l) was administered intraperitoneally only to the rats in the intervention group. The tissue sections were stained with hematoxylin and eosin and the pathological changes in liver tissues were observed and scored. The levels of TLR4 and NF-κB in liver tissues were quantified by western blotting. NAFLD rats appeared to have typical liver fatty degeneration and the expression of TLR4/NF-κB proteins and Hepcidin mRNA was significantly higher than that in the control group (P<0.05). However, the pathological changes observed in the intervention group had a marked improvement with a significant reduction in the TLR4/NF-κB protein and Hepcidin mRNA expression (P<0.05). In conclusion, the abnormal activation of the TLR4/NF-κB signaling pathway may cause NAFLD through the overexpression of Hepcidin.

Fabrication of porous poly(epsilon-caprolactone) microparticles for protein release

The particle morphology and in vitro release of protein from porous and non-porous PCL-F127 blended microparticles were evaluated. The BSA loaded PCL microparticles were prepared by the w/o/o/o emulsion-solvent evaporation method. Two types of homogenizer, a Polytron homogenizer and a probe ultrasonicator, were used to prepare the emulsion systems. The effects of solvent evaporation rate on the crystallinity and the performance of the microparticles were investigated. Both microparticles showed quite different shapes as well as surface morphology and release characteristics. The microparticles prepared with a Polytron homogenizer were quite porous in structure, which created channels for protein to continuously diffuse out, and resulted in sustained- and controlled-release characteristics. In addition, the initial burst release of protein from the microparticles was also reduced. Alteration of the evaporation rate of solvent did not change the crystallinity of the final microparticles. An influence of evaporation rate on the size of resulting microparticles was observed. The porous PCL microparticles were developed by choosing a proper homogenizer and fabrication conditions. Carefully controlling these variables resulted in microparticles with desirable release performance.

Characterization of protein-loaded poly(epsilon-caprolactone) microparticles based on a factorial design

This study was designed to systematically investigate the characteristics of bovine serum albumin (BSA) loaded poly(epsilon-caprolactine) (PCL) microparticles based on a 2(4) factorial experiment. The influences of polyvinyl pyrrolidone (PVP) concentration, BSA/PCL ratio, w/o/o/o ratio, and PEG/PCL ratio on the surface morphology, particle size, as well as the yield of microparticles, encapsulation efficiency of BSA, and in vitro release properties were evaluated. The microparticles were prepared by the w/o/o/o solvent evaporation method. The structure of BSA retained its integrity using this technique. The mean particle sizes of BSA-loded microparticles were in the range of 20-50 microm, and a highly porous morphology existed in these microparticles, irrespective of the formulations. The production yields of microparticles were in the range of 52.1-89.0%, and the encapsulation efficiencies were in the range of 13.8-68.3%. The burst release of BSA was in the range of 6.9-69.0%. The volume ration of the multi-phases significantly affected the encapsulation efficiency of BSA in PCL microparticles, and the initial amount of BSA encapsulated by PCL in terms of BSA/PCL ratio significantly affected the amount of BSA released at the end of 14 days (p < 0.05).

Influence of pluronics on protein-loaded poly(epsilon-caprolactone) microparticles

The objective of this study was designed to elucidate the importance of adding pluronics to PCL microparticles for the delivery of proteins. The influences of the type and the amount of pluronic on the surface morphology and release properties of protein-loaded PCL microparticles were evaluated. Microparticles were prepared by the w/o/o/o solvent evaporation technique with an ultrasonicator. All of the microparticles prepared were spherical in shape, with a rough surface due to crystallization of PCL in the microparticles. The pluronics efficiently prevented microparticles from aggregation, and the size of microparticles prepared was significantly reduced. The significant increase in the encapsulation efficiency and decrease in the burst release of protein from PCL microparticles were achieved by using pluronic F127. Incorporation of pluronic F127 increased the hydrophilicity of the matrix, which further retained protein in blended microparticles. Both pluronics PE10100 and L61 significantly reduced the crystallinity of PCL microparticles. Nevertheless, this result did not further influence the release property of BSA from these microparticles.

Reductions in binding and functions of D2 dopamine receptors in the rat ventral striatum during amphetamine sensitization

Rats receiving amphetamine (5 mg/kg, i.p. once daily) for 14 continuous days develop behavioral sensitization to a subsequent amphetamine challenge (1 mg/kg) at withdrawal days 8 to 10. The present study was aimed at investigating whether there are changes in binding or functions of striatal D2 dopamine receptors in amphetamine-sensitized rats. The results indicated that the Bmax value of D2 receptors in the ventral striatum decreased 40% and 52% 7 and 10 days after amphetamine withdrawal, respectively, without changes in their binding affinities (Kd). During this withdrawal period, the D(2/3) receptor agonist-induced (a) locomotor activation (bromocriptine, 5 mg/kg, i.p. or quinpirole, 1 mg/kg, i.p.) and (b) inhibition of forskolin-enhanced adenylyl cyclase activity (bromocriptine, 50 or 150 microM) in the ventral striatum were both suppressed as compared with saline controls. The decreases in D2 receptor function were unrelated to the coupled G-proteins, since none of the G alpha i-3, G alpha o or G alpha q in the ventral striatum exhibited quantitative differences between control and amphetamine sensitized rats. Collectively, these results demonstrate that intermittent amphetamine administration for a period of 14 days leads to diminished D2 receptor expression and functions in the ventral striatum at late withdrawal periods. The decrease of D2 receptors might reflect cellular mechanisms underlying the expression of amphetamine sensitization.