2004 Fiscal Year Final Research Report Summary
Analysis of the mechanism of regulation of lipid rafts within the lymphocyte plasma membrane by the lamellar-shaped nanodomain-structured surface
| Project/Area Number |
15500329
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Biomedical engineering/Biological material science
|
|---|
| Research Institution | Tokyo Women's Medical University |
|---|
Principal Investigator |
ABE Kazuhiko Tokyo Women's Medical University, School of Medicine, Assistant, 医学部, 助手 (90212539)
|
|---|
| Project Period (FY) |
2003 – 2004
|
| Keywords | lamellar-shaped nanodomain structure / lymphocyte / lipid raft / cholesterol / methyl-β-cyclodextrin / endoglycoceramidase II / GPI-anchored protein / electron microscopy |
|---|
| Research Abstract |
Recently, the presence of lipid rafts allowing efficient signal transduction within the plasma membrane of the cell was proposed by Simons K and Ikonen E. It was reported that a decrease in the cholesterol content of lipid rafts by treatment with methyl-β-cyclodextrin(MβCD) disturbed signal transduction, and that selective removal of carbohydrates from the glycosphingolipid of lipid rafts by treatment with endoglycoceramidase II plus activator II(EGPA) impaired activation of the Src family of tyrosine kinases through crosslinking of glycosylphosphatidylinositol(GPI)-anchored proteins. Based on these findings, this study was conducted to determine the role of the cholesterol and GPI-anchored proteins present on lipid rafts, in order to clarify the mechanism of inhibition of lymphocyte activation on PHEMA-b-PSt-b-PHEMA ABA type block copolymer(HSB) having a nanodomain-structured surface with a lamellar width of 16nm, consisting of hydrophilic poly (2-hydroxyethyl methacrylate)(PHEMA) for
… More
ming the A segment and hydrophobic polystyrene(PSt) forming the B segment. PSt and P(HEMA-co-St) random copolymers(HSR) were used as controls. An experiment of to determine the efficiency of interaction of lymphocytes with material surfaces was carried out by the microsphere column method. The lymphocytes were divided into three groups ; non-treated, MβCD-treated and EGPA-treated. The adherence of the lymphocytes to the material surfaces at room temperature for one hour was analyzed by electron microscopy. The non-treated lymphocytes adhering to the PSt and HSR surfaces showed spreading necrosis, whereas the lymphocytes adhering to the nanodomain-structured surfaces showed maintained shape and cytoarchitecture, similar to control lymphocytes. In the case of MβCD-and EGPA-treated lymphocytes, all the lymphocytes adhering to the PSt, HSR and nanodomain-structured surfaces exhibited maintained shape and cytoarchitecture, similar to control lymphocytes. From the above these results, it is surmised that the nanodomain-structured surface of HSB, in contrast to the PSt and HSR surfaces, allows maintenance of the structural integrity of the lipid rafts, and that activation of the Src family of tyrosine kinases is inhibited without an accumulation of lipid rafts containing the GPI-anchored proteins at the sites of lymphocyte adhesion on the nanodomain-structured surface. Less
|
