Investigating Correlation of Biomarkers in Individuals with Mild Cognitive Impairment

The size of the elderly population is increasing rapidly worldwide, and there is an increasing focus on maintaining cognitive function and preventing cognitive decline in older adults. The scale of cognitive decline seen in this older population ranges from normal cognitive decline seen with aging to dementia. Mild cognitive impairment (MCI) falls in between this range and can eventually progress to dementia. Physical exercise and mental exercise have been shown to induce different neurobiological mechanisms to promote neuroplasticity and neurogenesis. Combining both physical and cognitive exercise can maximize the neurological benefits from each, which is why the interactive Physical and Cognitive Exercise System (iPACES) was developed. The purpose of the iPACES study is to explore enhanced cognitive benefits of combining mental and physical exercise while using certain biomarkers to investigate their correlation with cognitive changes. One potential biomarker of interest is brain-derived neurotrophic factor (BDNF) which is a protein that plays a key role in the central nervous system through cell differentiation, neuronal development, neurogenesis, and synaptic plasticity. Another potential biomarker to study is ApoE, a protein secreted by brain cells that plays a key role in cellular uptake and clearance of amyloid deposits in neurodegenerative disorders. There are three alleles that result from single nucleotide polymorphisms: ApoE2, ApoE3, and ApoE4. We hypothesized that individuals with a certain ApoE genotype are more at risk to develop MCI and that BDNF can be used as a biomarker to track cognition in individuals with MCI. A novel approach was developed using dried blood spots to isolate DNA to determine ApoE genotypes by qPCR and to measure BDNF concentrations by ELISA. Identifying certain biomarkers should improve medical experts' ability to track cognitive function in patients with MCI.