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Aims: Neurodegenerative diseases are the leading cause of morbidity and mortality worldwide. Several studies have shown that tetramethylpyrazine (TMP) is an effective therapy for neurodegenerative diseases and that it acts by inhibiting the activation of microglial cells in response to inflammatory stimuli. However, the molecular mechanisms underlying the action of TMP remain unknown., Main Methods: Proteomic analysis was used to generate novel insights into the mechanism by which TMP inhibits microglial activation, and western blotting was used to validate candidate proteins., Key Findings: To identify candidate proteins affected by TMP in lipopolysaccharide-activated microglia, we performed proteomic analysis using iTRAQ labelling coupled with LC TRIPLE-TOF, and we identified 5187 unique proteins. Among these, 266 proteins were differentially expressed and considered putative candidate proteins. Protein annotation revealed that the differentially expressed proteins, such as inducible nitric oxide synthase (iNOS) and ERO1-like protein (ERO1L), might be involved in reducing cellular oxidation in response to stress. Ingenuity pathway analysis revealed that the differentially expressed proteins were involved in a variety of signalling pathways, including liver X receptor/retinoid X receptor (LXR/RXR) activation and the production of nitric oxide and reactive oxygen species in macrophages. Furthermore, one of the differentially expressed protein candidates detected by iTRAQ, iNOS, was confirmed by western blotting., Significance: Our data suggest that iTRAQ technology is an effective tool to study the mechanism by which TMP inhibits activated microglia. TMP decreased the expression of LXR/RXR-mediated iNOS, which reduced microglial activation in response to inflammatory stimuli., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Aim: The aim of this study is to explore the underlying molecular mechanism of curcumin-induced apoptosis in human hepatocellular carcinoma (HCC) Huh7 cells., Main Methods: Fas and FasL mRNA expression was analyzed by reverse transcription PCR. Western blot was applied to detect the protein expression of Bcl-2 family members, MAPK family members, c-Jun, c-Fos, ATF-2, caspase-3, PARP, TNF receptor family members and the respective ligands. Apoptotic cells were assayed with annexin V/PI double staining and flow cytometry., Key Findings: Curcumin treatment resulted in a fast and significant increase of Fas and Fas ligand (FasL) along with activation of caspase-3 and cleavage of PARP in Huh7 cells. Inhibition of caspase-3 activity by the specific inhibitor Z-DEVD-FMK rescued Huh7 cells from curcumin-induced apoptosis. Neutralization of FasL significantly protected the cells from curcumin-induced caspase-3 activation and apoptosis in a dose-dependent manner. Moreover, p38 was rapidly activated in response to curcumin, and inactivation of p38 by pharmacologic inhibitor SB203580 dramatically suppressed curcumin-induced FasL expression and apoptosis., Significance: Our results demonstrated that curcumin induces apoptosis through p38-denpendent up-regulation of FasL in Huh7 cells., (Copyright © 2012 Elsevier Inc. All rights reserved.)