مطالعه اثر پروتيين BAX بر ليزوزومهاي كبدي و نقش آن در مرگ برنامه ريزي شده سلول با استفاده از ميكروسكوپ الكتروني تراسميشن TEM در موش

A transmition electron microscopic study of the effects of Bax protein on hepatic lysosome and its role in apoptosis

Living cell die in two ways: Necrosis and programmed cell death (apoptosis). Necrosis is considered as an accidental death of a group of cells in a tissue. However, apoptosis is induced by a variety of stimulating agents (viruses, chimicals, etc.) or is programmed in old or embryonic cells. Apoptosis develops as the result of two intracellular pathways: Mitochondria and death receptors. In both pathways a group of protein compounds Bax proteins affect mitochondria, lysosome, endoplasmic reticulum and Golgi apparatus to induce the release of caspases which in their active form induce apoptosis. This study was performed to examine the ultrastractural changes of lysosomes invitro at the time of apoptosis .At first lysosomes were isolated from liver using ultracentrifugation, then these agent were exposed to Bax proteins at different time points. After fixation, processing, bloking and ultrathin section, the samples were imaged by a h-800 Olympus transmition electron microscope. The ultrastructural changes in lysosome, induced by Bax proteins were membrane shrinkage, granulation of the matrix and the rupture of membrane. This study defines the morphological feature of the changes in the ultra structure of lysosome during apoptosis.