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

Abstract

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.

Evaluation of the hepatotoxic risk caused by lead acetate via skin exposure using a proteomic approach

“…The statistical relevance of the ontological matches was calculated as the p ‐value, which is the probability of a match occurring by chance, given the size of the database. The p ‐value was calculated using the following formula: ; where N is the total number of nodes in the MetaCore database; R is the number of network objects corresponding to genes and proteins in the list; n is the total number of nodes in each small network generated from the list; and r is the number of nodes with data in each small network generated from the list .…”

Proteomic analysis reveals tanshinone IIA enhances apoptosis of advanced cervix carcinoma CaSki cells through mitochondria intrinsic and endoplasmic reticulum stress pathways

“…Protein spots were quantified using the Prodigy SameSpots software (Nonlinear Dynamics, Newcastle, UK). The expression levels of protein spots dysregulated by >1.5 fold with statistical significance ( p ‐value <0.05) between Tan IIA and control should be considered as proteins of interest . All experiments were biologically repeated three times to confirm the reproducibility.…”

Explore the Molecular Mechanism of Apoptosis Induced by Tanshinone IIA on Activated Rat Hepatic Stellate Cells

“…The sample slices were stained with hematoxylin-eosin (H/E) and Masson's trichrome (MT) for a histological assessment. Immunohistochemistry with α -SM-actin (at a 1 : 150 dilution in PBS; Neomarkers) was applied to specimens, as previously described [25, 26]. The histological changes were evaluated by using optical microscopy (Olympus BX51, Olympus Optical Co., Tokyo, Japan) in non consecutive, randomly chosen 200x or 400x histological fields.…”

“…Each spot intensity volume (%) was processed by background subtraction and total spot volume normalization; the resulting spot volume percentage was used for comparison between groups. More than 2.0-fold alterations at 95% confidence interval ( P < 0.05) were considered as statistically significant [26]. All experiments were repeated 3 times from three independent experiments.…”

“…Silver-stained spots were excised and in-gel digested with trypsin according to previously described procedures [26]. Briefly, the proteins were reduced with 25 mM NH 4 HCO 3 containing 10 mM DTT and alkylated with 55 mM iodoacetamide.…”