Functional proteomics reveals the protective effects of saffron ethanolic extract on hepatic ischemia‐reperfusion injury

Hepatic ischemia‐reperfusion (IR) injury is a common clinical problem and ROS may be a contributing factor on IR injury. The current study evaluates the potential protective effect of saffron ethanol extract (SEE) in a rat model upon hepatic IR injury. Caspases 3 and terminal deoxynucleotidyl transferase‐mediated dUTP biotin nick end labeling (TUNEL) results showed increased cell death in the IR samples; reversely, minor apoptosis was detected in the SEE/IR group. Pretreatment with SEE significantly restored the content of antioxidant enzymes (SOD1 and catalase) and remarkably inhibited the intracellular ROS concentration in terms of reducing p47phox translocation. Proteome tools revealed that 20 proteins were significantly modulated in protein intensity between IR and SEE/IR groups. Particularly, SEE administration could attenuate the carbonylation level of several chaperone proteins. Network analysis suggested that saffron extract could alleviate IR‐induced ER stress and protein ubiquitination, which finally lead to cell apoptosis. Taken together, SEE could reduce hepatic IR injury through modulating protein oxidation and our results might help to develop novel therapeutic strategies against ROS‐caused diseases.     

Functional proteomic and structural insights into molecular targets related to the growth inhibitory effect of tanshinone IIA on HeLa cells

Certain antitumor agents have recently been extracted from the roots of Salvia miltiorrhiza Bunge. The diterpene derivative, tanshinone IIA, possesses cytotoxic activity against several human carcinoma cell lines. It also inhibits invasion and metastasis of cancer cells. In the present study, we isolated tanshinone IIA from S. miltiorrhiza, and it exhibited strong growth inhibition against human cervical cancer cells in dose‐ and time‐dependent manners with a 50% cell growth inhibition value of 2.5 μg/mL (8.49 μM). Flow cytometric analysis of cell cycle progression revealed that G₂/M arrest was initiated after a 24 h exposure to the drug. It also resulted in DNA fragmentation and degradation of poly (ADP‐ribose) polymerase indicating that tanshinone IIA may be a potential antitumor agent. Furthermore, we performed a comprehensive proteomic analysis to survey global protein changes induced by tanshinone IIA treatment on HeLa cells. Significant changes in the levels of cytoskeleton proteins as well as stress‐associated proteins were observed. Immunoblot analysis and immunofluorescence staining were used to confirm the levels of protein expression. Overexpression of the vimentin rescued these tanshinone IIA‐induced events. Computational docking methods indicated that tanshinone IIA could stably bind to the β‐subunit of the microtubule protein. An interaction network analysis of these 12 proteins using MetaCore? software suggested that tanshinone IIA treatment regulated the expressions of proteins involved in apoptotic processes, spindle assembly, and p53 activation, including vimentin, Maspin, α‐ and β‐tubulin, and GRP75. Taken together, our results suggest that tanshinone IIA strongly inhibited the growth of cervical cancer cells through interfering in the process of microtubule assembly, leading to G₂/M phase arrest and sequent apoptosis. The success of this large‐scale effort was assessed by a bioinformatics analysis of proteins through predictions of protein domains and possible functional roles. The possible contributions of these proteins to the cytotoxicity of tanshinone IIA provide potential opportunities for the development of cancer therapeutics.     

Functional proteomics reveals hepatotoxicity and the molecular mechanisms of different forms of chromium delivered by skin administration

Chromium compounds are known to be associated with cytotoxicity and carcinogenicity when applied via the skin. However, there is no perspective research to elucidate the causations between chromium exposure and hepatotoxicity. In the present study, the impact of hexavalent/trivalent chromium on the liver and the underlying pathogenic processes were revealed in the female nude mice model. The liver damage under different treatments was evaluated by histologic examination. Functional proteome tools combined with a network analysis revealed statistically significant candidate protein networks predicted to be changed in the presence of chromium compounds. RNA interference-mediated silencing and immunohistochemistry were used to confirm whether the candidate protein was capable of resulting in hepatotoxicity elicited by chromium. Potassium chromate as the Cr(VI) compound generated greater oxidative stress, apoptosis and hepatotoxicity compared to chromium nitrate [Cr(III)]-treated samples. The most meaningful changes were observed amongst proteins involved in carbohydrate metabolism, endoplasmic reticulum (ER) stress, calcium homeostasis and apoptosis. Furthermore, abrogation of transitional ER ATPase (VCP) led to significant inhibition in hepatic cell viability under Cr(VI) administration, and the expression profiles of cytokeratin were closely correlated with apoptotic degrees of liver tissue. Collectively, our findings suggest that Cr(VI) might induce the accumulation of misfolded proteins and adverse effects leading to cell apoptosis and liver injury. These signature networks represent an approach to discover novel relationships in complex data, and functional proteomics of liver may provide solid evidence of chromium-caused hepatic damage via the skin.