Transcriptional Activation of Low-Density Lipoprotein Receptor Gene by DJ-1 and Effect of DJ-1 on Cholesterol Homeostasis

DJ-1 is a novel oncogene and also causative gene for familial Parkinson’s disease park7. DJ-1 has multiple functions that include transcriptional regulation, anti-oxidative reaction and chaperone and mitochondrial regulation. For transcriptional regulation, DJ-1 acts as a coactivator that binds to various transcription factors, resulting in stimulation or repression of the expression of their target genes. In this study, we found the low-density lipoprotein receptor (LDLR) gene is a transcriptional target gene for DJ-1. Reduced expression of LDLR mRNA and protein was observed in DJ-1-knockdown cells and DJ-1-knockout mice and this occurred at the transcription level. Reporter gene assays using various deletion and point mutations of the LDLR promoter showed that DJ-1 stimulated promoter activity by binding to the sterol regulatory element (SRE) with sterol regulatory element binding protein (SREBP) and that stimulating activity of DJ-1 toward LDLR promoter activity was enhanced by oxidation of DJ-1. Chromatin immunoprecipitation, gel-mobility shift and co-immunoprecipitation assays showed that DJ-1 made a complex with SREBP on the SRE. Furthermore, it was found that serum LDL cholesterol level was increased in DJ-1-knockout male, but not female, mice and that the increased serum LDL cholesterol level in DJ-1-knockout male mice was cancelled by administration with estrogen, suggesting that estrogen compensates the increased level of serum LDL cholesterol in DJ-1-knockout female mice. This is the first report that DJ-1 participates in metabolism of fatty acid synthesis through transcriptional regulation of the LDLR gene

Understanding the antecedents to customer loyalty by applying structural equation modeling

The purpose of this study is to employ structural equation modeling to find linear structural relationships related to customer satisfaction. Analysis of 495 car owners patronizing five automobile service and repair centers operated by Taiwan's three major car companies (Nissan, Toyota, and Mitsubishi), produced the following empirical results: customers' perceptions of price fairness, the level of employee - customer interaction, and customers' perceptions of product quality all have the direct, positive impact on customer satisfaction. The authors identified and examined three dimensions of perceived service quality that positively affect customers' trust levels. These three are tangibility, employee - customer interaction, and employee empathy. Customers' perceptions of price fairness and product quality, as well as customer satisfaction and trust are all positively related to customer loyalty. Customer satisfaction can also affect customer loyalty by helping customers create trust. In light of these empirical findings, this study also includes a discussion of possible implications for managers

Electron beam stimulated field-emission from single-walled carbon nanotubes

10.1116/1.1809628Journal of Vacuum Science and Technology B: Microelectronics and Nanometer Structures2263124-3127JVTB