Dynamic quantitative photothermal monitoring of cell death of individual human red blood cells upon glucose depletion.
Red blood cells (RBCs) have been found to undergo "programmed cell death," or eryptosis, and understanding this process can provide more information about apoptosis of nucleated cells. Photothermal (PT) response, a label-free photothermal noninvasive technique, is proposed as a tool to monitor the cell death process of living human RBCs upon glucose depletion. Since the physiological status of the dying cells is highly sensitive to photothermal parameters (e.g., thermal diffusivity, absorption, etc.), we applied linear PT response to continuously monitor the death mechanism of RBC when depleted of glucose. The kinetics of the assay where the cell's PT response transforms from linear to nonlinear regime is reported. In addition, quantitative monitoring was performed by extracting the relevant photothermal parameters from the PT response. Twofold increases in thermal diffusivity and size reduction were found in the linear PT response during cell death. Our results reveal that photothermal parameters change earlier than phosphatidylserine externalization (used for fluorescent studies), allowing us to detect the initial stage of eryptosis in a quantitative manner. Hence, the proposed tool, in addition to detection of eryptosis earlier than fluorescence, could also reveal physiological status of the cells through quantitative photothermal parameter extraction.
Nanyang Technological University, School of Electrical and Electronic Engineering, Photonics Research Center, 50 Nanyang Avenue, Singapore 639798.
Srivathsan
S
Vasudevan
George Chung Kit
GC
Chen
Marta
M
Andika
Shuchi
S
Agarwal
Peng
P
Chen
Malini
M
Olivo
D017209:Apoptosis / Q000502:physiology*; D001786:Blood Glucose / Q000378:metabolism*; D004905:Erythrocyte Aging; D004912:Erythrocytes / Q000166:cytology* / Q000378:metabolism*; D005434:Flow Cytometry; D006801:Humans; D066298:In Vitro Techniques; D007700:Kinetics; D054020:Lasers, Gas; D053844:Lasers, Solid-State; D018613:Microscopy, Confocal / Q000379:methods*; D008954:Models, Biological; D055620:Optical Phenomena
D001786:Blood Glucose