| Budget Amount *help |
¥3,600,000 (Direct Cost: ¥3,600,000)
Fiscal Year 2004: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 2003: ¥2,600,000 (Direct Cost: ¥2,600,000)
|
|---|
| Research Abstract |
Apoptosis, a programmed cell death, regulates many physiological homeostasis. Its deregulation is known to link to many human diseases such as cancer, neurodegenerative disorders, and atherosclerosis (Science 258:468,1992). There are two major pathways for induction of apoptosis. One is the extrinsic or receptor-mediated pathway represented by Fas and tumor necrosis factor α receptor. The other is the intrinsic pathway, in which mitochondria play a crucial role by releasing cytochrome C from the inter-membrane space into the cytoplasm. In this study, we have identified a novel gene upregulated in atherosclerotic lesions in apolipoprotein E-deficient mice, which are a model of atherosclerosis caused by hyperlipidemia. We compared the gene expression profile of vascular smooth muscle cells(VSMC) cultured from atherosclerotic plaque (P) to that from non-plaque in these mice. We succeeded to clone this novel gene and designated it as Apop-1. In order to clarify the function of this gene, A
… More
pop-1 expression vector, pcDNA3Apop-1, was introduced into cultured VSMC. Interestingly, introduction of this gene induces apoptosis of VSMC by releasing cytochrome C from mitochondria. The conditioned medium of the transfected cells had no capability to induce apoptosis, indicating that Apop-1-induced apoptosis is not mediated through secretary factors. We also demonstrated that Apop-1 gene has a mitochondria localization signal and Apop-1 protein is actually localized in mitochondria in Apop-1-transfected cells. Bcl-2 family proteins are known to regulate the release of cytochrome C from mitochondria. Importantly unlike Bcl-2 family members, Apop-1 possesses neither Bcl-2 homology (BH) nor carboxy terminal transmembrane (TM) domains. In addition, overexpression of Bcl-2 did not suppress Apop-1-induced apoptosis, suggesting that Apop-1 is a novel pro-apoptotic protein that release cytochrome C from mitochondria. We are now generating Apop-1 knockout mice and an adenoviral gene transfection system to analyze the function of this novel gene. Less
|
