Isopropoxy Tetramethyl Dioxaborolane on TiO: Reaction Pathway and Formation of a Visible-Light-Sensitive Photocatalyst.

Borate toxicity is a concern in agriculture since a high level of borates may likely exist in irrigation water systems. In this research, transmission infrared spectroscopy and X-ray photoelectron spectroscopy are employed to study the thermal and photochemical reactions of isopropoxy tetramethyl dioxaborolane (ITDB) on TiO, with the aid of density functional theory calculations. In addition, the possibility for the formation of a boron-modified TiO (B/TiO) surface, using ITDB as the boron source, is explored and the photocatalytic activity of the B/TiO is tested.

Bhlhe40 differentially regulates the function and number of peroxisomes and mitochondria in myogenic cells.

PGC-1α is a key regulator of oxidative metabolism facilitating the expression of genes critical for the function and biogenesis of the two key oxidative organelles, mitochondria and peroxisomes, in skeletal muscle (SKM) and other organs. Our recent studies have found that the transcription factor Bhlhe40 negatively regulates PGC-1α gene expression and its coactivational activity, therefore, this factor should have profound influence on the biogenesis and metabolic activity of mitochondria and peroxisomes. Here we found that both the number and activity of peroxisomes were increased upon knockdown of Bhlhe40 expression but were repressed by its over-expression.

Negative feedback regulation of AXL by miR-34a modulates apoptosis in lung cancer cells.

The AXL receptor tyrosine kinase is frequently overexpressed in cancers and is important in cancer invasion/metastasis and chemoresistance. Here, we demonstrate a regulatory feedback loop between AXL and microRNA (miRNA) at the post-transcriptional level. Both the GAS6-binding domain and the kinase domain of AXL, particularly the Y779 tyrosine phosphorylation site, are shown to be crucial for this autoregulation.

Bhlhe40 Represses PGC-1α Activity on Metabolic Gene Promoters in Myogenic Cells.

PGC-1α is a transcriptional coactivator promoting oxidative metabolism in many tissues. Its expression in skeletal muscle (SKM) is induced by hypoxia and reactive oxidative species (ROS) generated during exercise, suggesting that PGC-1α might mediate the cross talk between oxidative metabolism and cellular responses to hypoxia and ROS. Here we found that PGC-1α directly interacted with Bhlhe40, a basic helix-loop-helix (bHLH) transcriptional repressor induced by hypoxia, and protects SKM from ROS damage, and they cooccupied PGC-1α-targeted gene promoters/enhancers, which in turn repressed PGC-1α transactivational activity.

Insulin and LiCl synergistically rescue myogenic differentiation of FoxO1 over-expressed myoblasts.

Most recent studies reported that FoxO1 transcription factor was a negative regulator of myogenesis under serum withdrawal condition, a situation not actually found in vivo. Therefore, the role of FoxO1 in myogenesis should be re-examined under more physiologically relevant conditions. Here we found that FoxO1 was preferentially localized to nucleus in proliferating (PMB) and confluent myoblasts (CMB) and its nuclear exclusion was a prerequisite for formation of multinucleated myotubes (MT).

FoxO6 and PGC-1α form a regulatory loop in myogenic cells.

Transcription factors of the FoxO (forkhead box O) family regulate a wide range of cellular physiological processes, including metabolic adaptation and myogenic differentiation. The transcriptional activity of most FoxO members is inhibitory to myogenic differentiation and overexpression of FoxO1 inhibits the development of oxidative type I fibres in vivo. In this study, we found that FoxO6, the last discovered FoxO family member, is expressed ubiquitously in various tissues but with higher expression levels in oxidative tissues, such as brain and oxidative muscles.