التفاصيل البيبلوغرافية
العنوان: |
Renal ischemia induces tropomyosin dissociation-destabilizing microvilli microfilaments. |
المؤلفون: |
Ashworth, Sharon L., Wean, Sarah E., Campos, Silvia B., Temm-Grove, Constance J., Southgate, Erica L., Vrhovski, Bernadette, Gunning, Peter, Weinberger, Ron P., Molitoris, Bruce A. |
المصدر: |
American Journal of Physiology: Renal Physiology; May2004, Vol. 286, pF988-F996, 9p, 10 Color Photographs, 17 Black and White Photographs, 1 Diagram |
مصطلحات موضوعية: |
ISCHEMIA, KIDNEY injuries, TROPOMYOSINS, KIDNEY tubules, MICROFILAMENT proteins, CYTOPLASMIC filaments |
مستخلص: |
Ischemic-induced cell injury results in rapid duration-dependent actindepolymerizing factor (ADF)/cofilin-mediated disruption of the apical microvilli microfilament cores. Because intestinal microvillar microfilaments are bound and stabilized in the terminal web by the actinbinding protein tropomyosin, we questioned whether a protective effect of tropomyosin localization to the terminal web of the proximal tubule microfilament cores is disrupted during ischemic injury. With tropomyosin-specific antibodies, we examined rat cortical sections under physiological conditions and following ischemic injury by confocal microscopy. In addition, Western blot analysis of cortical extracts and urine was undertaken. Our studies demonstrated the presence of tropomyosin isoforms in the proximal tubule microvillar terminal web under physiological conditions and their dissociation in response to 25 min of ischemic injury. This correlated with the excretion of tropomyosin-containing plasma membrane vesicles in urine from ischemic rats. In addition, we noted increased tropomyosin Triton X-100 solubility following ischemia in cortical extracts. These studies suggest tropomyosin binds to and stabilizes the microvillar microfilament core in the terminal web under physiological conditions. With the onset of ischemic injury, we propose that tropomyosin dissociates from the microfilament core providing access to microfilaments in the terminal web for F-actin binding, severing and depolymerizing actions of ADF/cofilin proteins. [ABSTRACT FROM AUTHOR] |
|
Copyright of American Journal of Physiology: Renal Physiology is the property of American Physiological Society and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.) |
قاعدة البيانات: |
Complementary Index |