Reduced WIF-1 expression stimulates skin hyperpigmentation in patients with melasma.

The expression of Wnt inhibitory factor-1 (WIF-1) gene, which was detected by a microarray analysis of hyperpigmented and normally pigmented skin sets of melasma patients, was significantly reduced in the hyperpigmented skin from melasma patients, but not in healthy controls, regardless of UV irradiation. Wnt signals regulate skin pigmentation; however, WIF-1 is expressed in cultured skin keratinocytes and fibroblasts, but not in melanocytes. Therefore, we examined whether WIF-1 knockdown in neighboring keratinocytes and fibroblasts plays a role in melasma.

Predose blood gene expression profiles might identify the individuals susceptible to carbon tetrachloride-induced hepatotoxicity.

Although the extent of chemical-induced liver injury differs substantially from individual to individual, it is very hard to identify susceptible population priori to chemical exposure. We report here that the gene expression of the blood samples collected predose might identify the susceptible population without actual exposure to hepatotoxicant. The innate gene expressions in the blood samples collected at predose were compared using whole-genome microarray analysis and semiquantitative PCR with the extent of hepatotoxicity following the treatment of a model hepatotoxicant, carbon tetrachloride (CCl(4)) posteriori.

The effects of BADGE and caffeine on the time-course response of adiponectin and lipid oxidative enzymes in high fat diet-fed C57BL/6J mice: correlation with reduced adiposity and steatosis.

Adiponectin, which is expressed exclusively in adipose tissue, has been shown to increase fatty acid oxidation via activation of AMP-activated kinase (AMPK) and phosphorylation of acetyl CoA carboxylase (ACC). ACC phosphorylation and carnitine palmitoyl-transferase-1 (CPT1) activity have been shown to be rate controlling factors in fatty acid oxidation. In high fat diet (HFD)-induced obese mice, we analyzed the time-course of changes in the expression of adiponectin and lipid oxidative enzymes induced by treatment with bisphenol A diglycidyl ether (BADGE) or caffeine for 8 weeks, and investigated whether the changes of adiponectin and lipid oxidative enzymes expression correlated with reduced adiposity or steatosis after 8 weeks of treatment.

Chip-based analysis of SUMO (small ubiquitin-like modifier) conjugation to a target protein.

A chip-based analysis of protein interactions and modifications in cell signaling pathways has been of great potential in drug discovery, diagnostics, and cell biology, because it enables rapid and high-throughput biological assays with a small amount of samples. We report a chip-based analysis of sumoylation, the post-translational modification (PTM) process that involves covalent attachment of the small ubiquitin-like modifier (SUMO) protein to a target protein through multiple enzyme reactions in eukaryotic cells. Substrate proteins were spotted onto a glass surface followed by the addition of the reaction mixture for sumoylation, and the SUMO conjugation was readily detected by using fluorescent dye-labeled antibody.