Secreted Stomatin Can Trigger Multi-nucleated Cell Formation

• Main Authors: Jui-Hao Lee, 李睿豪
• Other Authors: Chi-Hung Lin
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/51681262070811943174

碩士 === 國立陽明大學 === 微生物及免疫學研究所 === 97 === Stomatin is a 31.5 kDa integral membrane protein or lipid rafts associated protein. It was named after the rare overhydrated hereditary stomatocytosis (OHSt) occurred in human. The distribution of human stomatin expression is major in peripheral blood, bone marrow, placenta, fetal lung, and fetal liver. Stomatin was absent or reduced from OHSt patients, but the mutated stomatin gene or stomatin gene knock out mice were not implicated any erythrocytes phenotype as OHSt patients. Although, the function of the stomatin is still unknown, there are some researches or proposals about stomatin orthologues or stomatin-like proteins. For examples, MEC-2, and UNC-24 in Caenorhablitis elegans; P-stomatin in Archaea; Pfstomatin in Plasmodium falciparum; some of the function of the orthologues have been proposed and partly elucidated, and the proteins are crucial for ion transport, mechanosensation, and parasites infection. Because the function of the human stomatin that we know little, even unknown, this short report will indicate the new role of stomatin in multi-nucleated cell formation, especially stomatin may present as secreted form. In the past study of our lab, cell models were transfected with stomatin gene, and we discovered the multi-nucleated cell formations occurred. In this report, I found the stomatin could be secreted to the extracellular medium by using immunoprecipitation and transwell assay to prove. In addition, the secreted stomatin could associate directly with the cell membrane or lipid rafts of the neighboring cells through transwell. Therefore, the condition medium containing secreted stomatin were used to treat CHO-K1 cells or HEK-293T cells, and the multi-nucleated cell formations were induced, too. Besides, our data suggested how the multi-nucleated cells formed. A series of time-lapse images were analyzed, and we indicated that the multi-nucleated cells were from abnormal cell mitosis, called post-mitotic cell fusion or furrow regression, and cell fusion. We conclude that the stomatin can be secreted to the extracellular medium and associate with the membranes of neighboring cells. The affected cells are induced to form multi-nucleated cells through furrow regression and cell fusion.