Comparison of cellular responses induced by low level light in different cell types

Ying Ying Huang, Aaron C.H. Chen, Sulbha K. Sharma, Qiuhe Wu, Michael R. Hamblin

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review

4 Citations (Scopus)


Discoveries are rapidly being made in multiple laboratories that shed "light" on the fundamental molecular and cellular mechanisms underlying the use of low level light therapy (LLLT) in vitro, in animal models and in clinical practice. Increases in cellular levels of respiration, in cytochrome c oxidase activity, in ATP levels and in cyclic AMP have been found. Increased expression of reactive oxygen species and release of nitric oxide have also been shown. In order for these molecular changes to have a major effect on cell behavior, it is likely that various transcription factors will be activated, possibly via different signal transduction pathways. In this report we compare and contrast the effects of LLLT in vitro on murine embryonic fibroblasts, primary cortical neurons, cardiomyocytes and bone-marrow derived dendritic cells. We also examined two human cell lines, HeLa cancer cells and HaCaT keratinocytes. The effects of 810-nm near-infra-red light delivered at low and high fluences were addressed. Reactive oxygen species generation, transcription factor activation and ATP increases are reported. The data has led to the hypothesis that cells with a high level of mitochondrial activity (mitochondrial membrane potential) have a higher response to light than cells with low mitochondrial activity.

Original languageEnglish
Title of host publicationMechanisms for Low-Light Therapy V
Publication statusPublished - 2010
Externally publishedYes
EventMechanisms for Low-Light Therapy V - San Francisco, CA, United States
Duration: 23 Jan 201025 Jan 2010

Publication series

NameProgress in Biomedical Optics and Imaging - Proceedings of SPIE
ISSN (Print)1605-7422


ConferenceMechanisms for Low-Light Therapy V
Country/TerritoryUnited States
CitySan Francisco, CA


  • ATP
  • Biostimulation
  • Cytochrome c oxidase
  • Low level laser therapy
  • Mitochondria
  • Nuclear factor kappa B
  • Reactive oxygen species

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Biomaterials
  • Atomic and Molecular Physics, and Optics
  • Radiology, Nuclear Medicine and Imaging


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