The long-term photobiomodulation of 810 nm LED light on the IMR-32 human neuroblastoma cell line was investigated. Daily light treatments of 1.26 J/cm2 and 1.755 J/cm2 both increase resistance to doxorubicin, sodium azide, and FCCP toxicity. However, 1.26 J/cm2 increases the mitochondrial DNA copy number, alters cell cycle-related pathways’ RNA expression, and promotes cell division. Operating differently, 1.755 J/cm2 decreases the mitochondrial DNA copy number and activates the oxidative phosphorylation pathway at the RNA, protein, and functional levels. The 810 nm light treatment shows two different long-term dose-dependent effects on cellular and mitochondrial activities.
Significance: Investigating cell death dynamics at the single-cell level plays an essential role in biological research. Quantitative phase imaging (QPI), a label-free method without adverse effects of exogenous labels, has been widely used to image many types of cells under various conditions. However, the dynamics of QPI features during cell death have not been thoroughly characterized.
Aim: We aim to develop a label-free technique to quantitatively characterize single-cell dynamics of cellular morphology and intracellular mass distribution of cells undergoing apoptosis and necrosis.
Approach: QPI was used to capture time-lapse phase images of apoptotic, necrotic, and normal cells. The dynamics of morphological and QPI features during cell death were fitted by a sigmoid function to quantify both the extent and rate of changes.
Results: The two types of cell death mainly differed from normal cells in the lower phase of the central region and differed from each other in the sharp nuclear boundary shown in apoptotic cells.
Conclusions: The proposed method characterizes the dynamics of cellular morphology and intracellular mass distributions, which could be applied to studying cells undergoing state transition such as drug response.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.