Jessica T. Smith, Ph.D.

Postdoc Fellow

National Institute on Aging

Mitochondrial DNA (mtDNA) variants that define mtDNA haplogroups have been associated with disease risk or protection. However, few studies have examined the contribution of mtDNA haplogroup to exacerbated differences in age- and race-related health disparities, such as hypertension or inflammatory state. In addition, most research on mtDNA haplogroups has been performed in cell lines or in race/mtDNA ancestry homogeneous cohorts. Dr. Smith hypothesizes that ancestry as determined by mtDNA haplogroups will influence DNA damage and repair as well as mitochondrial function in the context of hypertension and inflammatory state.

The study’s pilot cohort will consist of 104 middle-aged Black/African American and White participants in the Healthy Aging in Neighborhoods of Diversity across the Life Span (HANDLS) study balanced across mtDNA ancestry, sex, and hypertension status. Dr. Smith will measure DNA damage and repair capacity in nuclear DNA by utilizing the high throughput alkaline comet assay, CometChip. The team will evaluate mitochondrial function via Seahorse assays and antibody kits. Dr. Smith will also assess serum inflammatory markers using a multiplex assay kit. mtDNA haplogroups in the expanded cohort of 287 HANDLS participants will be determined using allelic discrimination PCR assays.

Investigating the influence of mtDNA haplogroups on hypertension, mitochondrial function, and DNA damage/repair will lead to a more complete understanding of the mitochondrial connection to age-related health disparities, inflammatory state, and aging among racial and ethnic minority populations.