Biophotonic probing of macromolecular transformations during apoptosis — PNAS

Biophotonic probing of macromolecular transformations during apoptosis
Artem Pliss, Andrey N. Kuzmin, Aliaksandr V. Kachynski, and Paras N. Prasad1
+ Author Affiliations

Institute for Lasers, Photonics and Biophotonics, University at Buffalo, State University of New York, Buffalo, NY 14260-3000
Edited* by Peter M. Rentzepis, University of California, Irvine, CA, and approved June 8, 2010 (received for review May 10, 2010)

Abstract
We introduce here multiplex nonlinear optical imaging as a powerful tool for studying the molecular organization and its transformation in cellular processes, with the specific example of apoptosis. Apoptosis is a process of self-initiated cell death, critically important for physiological regulation and elimination of genetic disorders. Nonlinear optical microscopy, combining the coherent anti-Stokes Raman scattering (CARS) microscopy and two-photon excited fluorescence (TPEF), has been used for analysis of spatial distribution of major types of biomolecules: proteins, lipids, and nucleic acids in the cells while monitoring their changes during apoptosis. CARS imaging revealed that in the nuclei of proliferating cells, the proteins are distributed nearly uniformly, with local accumulations in several nuclear structures. We have found that this distribution is abruptly disrupted at the onset of apoptosis and is transformed to a progressively irregular pattern. Fluorescence recovery after photobleaching (FRAP) studies indicate that pronounced aggregation of proteins in the nucleoplasm of apoptotic cells coincides with a gradual reduction in their mobility.

biomolecular distributionCARS imagingcell

Footnotes
1To whom correspondence should be addressed. E-mail: pnprasad@acsu.buffalo.edu. Author contributions: A.P., A.N.K., A.V.K., and P.N.P. designed research; A.P., A.N.K., and A.V.K. performed research; A.P., A.N.K., A.V.K., and P.N.P. analyzed data; and A.P., A.N.K., A.V.K., and P.N.P. wrote the paper.
The authors declare no conflict of interest.
*This Direct Submission article had a prearranged editor.
This article contains supporting information online at www.pnas.org/lookup/suppl/doi:10.1073/pnas.1006374107/-/DCSupplemental.

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Biophotonic probing of macromolecular transformations during apoptosis — PNAS