The Scientific World Journal

The Scientific World Journal / 2002 / Article

Short Communication | Open Access

Volume 2 |Article ID 514027 | https://doi.org/10.1100/tsw.2002.227

May-Ghee Lum, Tetsuhiro Minamikawa, Phillip Nagley, "Microscopic Photosensitization: A New Tool to Investigate the Role of Mitochondria in Cell Death", The Scientific World Journal, vol. 2, Article ID 514027, 11 pages, 2002. https://doi.org/10.1100/tsw.2002.227

Microscopic Photosensitization: A New Tool to Investigate the Role of Mitochondria in Cell Death

Received15 Feb 2002
Accepted20 Mar 2002

Abstract

Active involvement of mitochondria in cell death has been well-documented, but local apoptotic signaling between subsets of mitochondria has been poorly explored to date. Using mitochondrially localized CMXRos as a photosensitizer coupled to laser irradiation by confocal laser scanning microscopy, we demonstrate that partial irradiation of about half the mitochondria in human 143B TK cells induces rapid loss of mitochondrial membrane potential (ΔΨm) in nonirradiated mitochondria. Cells so partially irradiated show apoptotic indications, including mobilization of cytochrome c and binding of annexin V within 2 h following irradiation. The loss of ΔΨm in nonirradiated mitochondria did not occur in cells photoirradiated in the absence of CMXRos. Increasing the proportion of irradiated mitochondria in each cell (up to about 50%) generated a correspondingly greater percentage of cells in which nonirradiated mitochondria lost ΔΨm and which also showed apoptotic indications. Only at the highest level of irradiation (global for all mitochondria in one cell) were signs of necrosis evident (judged by uptake of propidium iodide). Because laser irradiation is specific to the subpopulation of mitochondria targeted, the data imply that a signal emanating from irradiated mitochondria is processed by their nonirradiated counterparts. We conclude that intermitochondrial signaling occurs in the subcellular response to induction of apoptosis.


More related articles

 PDF Download Citation Citation
 Order printed copiesOrder
Views112
Downloads426
Citations

Related articles

Article of the Year Award: Outstanding research contributions of 2020, as selected by our Chief Editors. Read the winning articles.