No abstract

Baicalein is one of the major flavonoids found in the root of Scutellaria baicalensis Georgi. Previous studies suggest that baicalein displays protective effect on experimental cardiac models in vitro and in vivo. However, the mode of action remains unclear. Here, we showed that baicalein conferred cardioprotective effect against oxidative stress-induced cell injury in H9c2 cells and human embryonic stem cells-derived cardiomyocytes. Immunoprecipitation with anti-NF-E2-related factor 2 (Nrf2) antibody in baicalein-treated cells demonstrated that baicalein effectively disrupted the association between Nrf2 and Kelch-like epichlorohydrin-associated protein 1 (Keap1). In addition, the unbounded Nrf2 translocated from cytoplasm to nucleus and increased Nrf2/heme oxygenase-1 (HO-1) content in a time-dependent manner. Moreover, antioxidant response element transcriptional activity was enhanced by baicalein treatment, and the Nrf2 siRNA transfection could block the cytoprotective effect of baicalein. Taken together, these results demonstrate that baicalein protected cardiomyocytes against oxidative stress-induced cell injury through the Nrf2/Keap1 pathway.

Using a yeast two-hybrid screen, human 14-3-3 epsilon protein was found to interact with human calmodulin. In vitro binding assay between human 14-3-3 epsilon protein/peptide and calmodulin was demonstrated by native gel electrophoresis, and the interaction was shown to be calcium dependent. Our results, along with the association of the 14-3-3 epsilon protein with other signaling proteins, suggest that the 14-3-3 protein could provide a link between signal transduction and cell proliferation.

No abstract

A novel cDNA clone was isolated from a human adult heart cDNA library. This cDNA clone is similar to the small heat shock protein (smhsp) in both DNA and amino acid sequences, especially in the conserved region. Sequence analysis has shown that the putative novel smhsp, named 27 kDa heat-shock-protein-like protein (HSPL27) is a protein of 241 amino acids with a deduced molecular mass of 26.7 kDa and a deduced pI of 8.0. We have expressed the HSPL27 in E. coli and the expressed protein was found to be present in the soluble fraction of the bacterial cell lysate. Chromosomal mapping data shows that the HSPL27 gene is located at human chromosome 5q11.2.