Oxidative Stress Group

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The OSG ethos is to nurture and support all group members, helping them to achieve their goals, and become the best researchers possible. We aim to hone OSG member's individual skills, creativity, and innovation to advance them in their study of oxidative stress and genomic instability.

(Put simply, no one is too senior, or too experienced to be mentored.)

Welcome to the Oxidative Stress Group (OSG).

We study the impact of the exposome (the sum of environmental exposures across the lifespan) on oxidative stress, and genomic instability. We evaluate basic mechanisms all the way to translational application of validated biomarkers to study human health and disease. To do this, we to combine our teamwork, with national and international, multidisciplinary collaborations, to apply the very best expertise to address major medical questions.

Specifically, we examine the formation and repair of damage to nuclear/mitochondrial DNA and the nucleotide precursor pools; and the development and application of nucleic acid adductomics i.e., (i) the totality of nucleic acid adducts in cells, and urine; and (ii) the genome-wide mapping of DNA damage, to study the role of nucleic acid damage in health and disease.

In the beginning...

Dr. Cooke became the lead of OSG in 2005 at the University of Leicester UK, and in the subsequent nine years it developed into one of the foremost groups in the world undertaking oxidative stress research, specifically examining DNA damage. OSG transferred to the US in 2014, moving to the University of South Florida in 2020.

Learn about what we're doing!

Our research at a glance

Use of urinary DNA adductomics to dissect the substrates and pathways of DNA repair

The exposome is a concept that encompasses the totality of endogenous and exogenous exposures throughout the lifespan of an individual. Evaluation of the exposome across the life course of a person is a difficult challenge from the absence of methodologies to the lack of sensitivity. Cellular DNA adductomics aims to assess the totality of DNA adducts in the genome, however, the method requires invasive sampling of tissue to obtain sufficient DNA. We recently proposed the development of a non-invasive technique to circumvent this problem by applying DNA adducomics to urine to simultaneously assess 2'-deoxyribonucleosides and nucleobase adducts using LC QqQ-MS/MS. Our method will provide the tools to non-invasively assess the totality of DNA adducts and contribute to the evaluation of the exposome.

Influence of bacterial infection on host genome instability

We have shown that bacterial infection can influence the host DNA damage response, but we are yet to understand the mechanisms responsible, and whether this influences the outcome of infection. In order to investigate this, we are currently using S. aureus as a bacterial model for infection. We will be employing techniques such as comet assay and qPCR to detect damage.

Full list of research projects here

Recent Activities and Publications

JoVe video!

Check out our video on how to perform the comet assay using our modified methods and patented equipment. See the video below or check out this link Video

A High-Throughput Comet Assay Approach for Assessing Cellular DNA Damage

Yunhee Ji, Mahsa Karbaschi, Abdulhadi Abdulwahed, Natalia S. Quinete, Mark D. Evans, Marcus S. Cooke

PDF download

Full list of publications

A High-Throughput Comet Assay Approach for Assessing Cellular DNA Damage | ProtocolScientific Video Article | The comet assay is a popular means of detecting DNA damage. This study describes an approach to running slides in representative...

A High-Throughput Comet Assay Approach for Assessing Cellular DNA Damage

Yunhee Ji (*1), Mahsa Karbaschi (*2), Abdulhadi Abdulwahed (*3), Natalia S. Quinete (4), Mark D. Evans (5), Marcus S. Cooke (1)

Oxidative Stress Group, Dept. Cell Biology, Microbiology and Molecular Biology, College of Arts and Sciences, University of South Florida
Cepheid (Danaher Corp.), US Technical Operations
Department of Clinical Laboratory Sciences, College of Applied Medical Sciences, King Saud University
Department of Chemistry and Biochemistry, Institute of Environment, Florida International University
Leicester School of Allied Health Sciences, Faculty of Health and Life Sciences, De Montfort University

* These authors contributed equally

The comet assay is a popular means of detecting DNA damage. This study describes an approach to running slides in representative variants of the comet assay. This approach significantly increased the number of samples while decreasing assay run-time, the number of slide manipulations, and the risk of damage to gels.

Interested in our field of research? Check out these webinars to gain more insight:

Joining Forces of Data Science and the Exposome

Chirag Patel Ph.D., of Harvard Medical School and Arcot Rajasekar, Ph.D., of UNC School of Information September 16, 20221:00 PM – 2:00 PM EDT

Description: "Exposomics datasets can be very large and originate from heterogeneous sources. Gaining meaningful insights from datasets can be streamlined by data science methods. These methods, including machine learning and artificial intelligence models, can help to discover relationships among phenotypes, biological responses and exposures."

See the recorded session here

Translation of Exposomics to Precision Medicine and Precision Nutrition

Robert O. Wright, MPH, MD, Professor, Icahn School of Medicine at Mount Sinai and Susan Sumner, PhD., University of North Carolina

Description: "An individual’s exposome can modulate their response to a drug or nutritional interventions by interacting with the targeted biological mechanisms. Integration of exposomics in precision medicine and precision nutrition strategies can enable new tailored approaches to maximize a person’s response to therapeutics. In this webinar Dr. Wright and Dr. Sumner will discuss the emerging role of exposomics in precision medicine and precision nutrition research."

See the recorded session here.

A Bird's Eye Overview of the Exposome and HHEAR Program

David Balshaw, Ph.D. , Branch Chief, Exposure, Response, and Technology Branch, NIHMarch 1, 2022

Description: "In this inaugural event of the HHEAR Exposomics Webinar Series, Dr. David Balshaw, Chief of the Exposure, Response, and Technology Branch at NIEHS, provides an overview of the exposome and the Human Health Exposure Analysis Resource (HHEAR)."

See the recorded session here