CometChip analysis of human primary lymphocytes enables quantification of inter-individual differences in the kinetics of repair of oxidative DNA damage

Le P Ngo; Simran Kaushal; Isaac A Chaim; Patrizia Mazzucato; Catherine Ricciardi; Leona D Samson; Zachary D Nagel; Bevin P Engelward

doi:10.1016/j.freeradbiomed.2021.07.033

CometChip analysis of human primary lymphocytes enables quantification of inter-individual differences in the kinetics of repair of oxidative DNA damage

Free Radic Biol Med. 2021 Oct:174:89-99. doi: 10.1016/j.freeradbiomed.2021.07.033. Epub 2021 Jul 26.

Authors

Le P Ngo¹, Simran Kaushal², Isaac A Chaim³, Patrizia Mazzucato⁴, Catherine Ricciardi⁵, Leona D Samson⁶, Zachary D Nagel⁷, Bevin P Engelward⁸

Affiliations

¹ Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA; MIT Center for Environmental Health Sciences, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA.
² Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA; MIT Center for Environmental Health Sciences, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA; Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA, 02115, USA. Electronic address: kaushal@mit.edu.
³ Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA; MIT Center for Environmental Health Sciences, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA. Electronic address: iachaim@ucsd.edu.
⁴ Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA; MIT Center for Environmental Health Sciences, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA. Electronic address: patrizia.mazzucato@gmail.com.
⁵ MIT Center for Environmental Health Sciences, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA; MIT Clinical Research Center, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA. Electronic address: c_ricci@mit.edu.
⁶ Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA; MIT Center for Environmental Health Sciences, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA; Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA. Electronic address: lsamson@mit.edu.
⁷ Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA, 02115, USA. Electronic address: znagel@hsph.harvard.edu.
⁸ Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA; MIT Center for Environmental Health Sciences, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA. Electronic address: bevin@mit.edu.

PMID: 34324980
PMCID: PMC8477454
DOI: 10.1016/j.freeradbiomed.2021.07.033

Abstract

Although DNA repair is known to impact susceptibility to cancer and other diseases, relatively few population studies have been performed to evaluate DNA repair kinetics in people due to the difficulty of assessing DNA repair in a high-throughput manner. Here we use the CometChip, a high-throughput comet assay, to explore inter-individual variation in repair of oxidative damage to DNA, a known risk factor for aging, cancer and other diseases. DNA repair capacity after H₂O₂-induced DNA oxidation damage was quantified in peripheral blood mononuclear cells (PBMCs). For 10 individuals, blood was drawn at several times over the course of 4-6 weeks. In addition, blood was drawn once from each of 56 individuals. DNA damage levels were quantified prior to exposure to H₂O₂ and at 0, 15, 30, 60, and 120-min post exposure. We found that there is significant variability in DNA repair efficiency among individuals. When subdivided into quartiles by DNA repair efficiency, we found that the average t_1/2 is 81 min for the slowest group and 24 min for the fastest group. This work shows that the CometChip can be used to uncover significant differences in repair kinetics among people, pointing to its utility in future epidemiological and clinical studies.

Keywords: CometChip; DNA damage; DNA repair; Repair kinetics.

Publication types

Research Support, N.I.H., Extramural

MeSH terms

Comet Assay
DNA Damage
DNA Repair
Humans
Hydrogen Peroxide*
Individuality
Kinetics
Leukocytes, Mononuclear*
Lymphocytes
Oxidative Stress / genetics

Substances

Hydrogen Peroxide

Abstract

Publication types

MeSH terms

Substances

Grants and funding