Location: Jean Mayer Human Nutrition Research Center On Aging
2021 Annual Report
Objectives
Objective 1: Determine the effects of genetic, molecular and environmental influences on the aging brain, and the modifying impact of specific phytonutrients on neural cell function and behavior, including cognition.
Sub-Objective 1a: Characterize genetic and molecular signatures, especially pro-inflammatory markers, of normal adult brain stem/progenitor and differentiated cells, including neurons and microglia, in vitro and following the introduction of whole berry fruits and a combination phytonutrient: polymolecular botanical compound (PBC).
Sub-Objective 1b: Characterize genetic and molecular signatures of normal neural stem/progenitor and differentiated cells from Sub-Objective 1a in vivo following their grafting to the forebrains of immunocompromised mice, and subsequent feeding of the phytonutrients assayed in the in vitro model of Sub-Objective 1a.
Sub-Objective 1c: Characterize the genetic and molecular signatures, especially those associated with chronic inflammatory pathways, and the cognitive behavioral profile in aging models in rodents following feeding of phytonutrient compounds studied in Sub-Objectives 1a and b.
Sub-Objective 1d: Analyze biomarkers, especially those related to chronic inflammation and the cognitive behavioral profile, from liquid biopsies (e.g., serum) collected in human studies following phytonutrient supplementation with the candidate fruit and plant compounds studied in Sub-Objectives 1a-c.
Objective 2: Characterize in vitro and in vivo models that manifest aspects of human age-related neurological diseases, such as Parkinson’s and Alzheimer’s disease, for screening combinations of phytonutrient that can prevent or delay chronic inflammation and other deleterious micro-environmental conditions that contribute to cell degeneration in the neurodegenerative disorders.
Sub-Objective 2a: Characterize, in vitro, the genetic and molecular signatures, especially those associated with chronic inflammatory pathways, of stem/progenitor and differentiated neural and microglial cells (and exosomes isolated from them) isolated from patients with Parkinson’s Disease, following phytonutrient treatments studied in Objective 1.
Sub-Objective 2b: Characterize, in vivo, the genetic and molecular signatures (including mutant LRRK2-associated inflammation, stem cell and cell death/protection gene pathways) of cells, and exosomes derived from them, following xenotransplantation to the forebrain of immunocompromised mice and feeding of the phytonutrients studied in Objective 1.
Sub-Objective 2c: Characterize the genetic and molecular signatures of neural cells at-risk for abnormal functioning and cell death in transgenic mouse models of Parkinson’s disease, including behavioral studies, following feeding of candidate phytonutrient compounds studied in Objective 1.
Approach
As Americans are living longer, the incidence of age-related neurological disorders is a growing burden for older adults and the healthcare system. Our lab studies how plant-derived phytonutrients benefit the aging brain, especially in maintaining mobility and cognitive function and slowing the progression of neurological disease. Specifically, we look at the ways phytonutrients can counteract the changes in the aging brain that make it more susceptible to neurological disorders. We focus on the persistent activation of inflammatory pathways that reduce brain plasticity and, over time, contribute to destructive cellular changes which affect the nervous system’s functioning and ability to adapt to new experiences. We will analyze the anti-inflammatory properties of phytonutrient combinations and berries that contain numerous beneficial bioactives that target aging processes involving cellular communication and the propagation of disease. In vitro and in vivo bioassays utilizing human stem/progenitor cells and the brain’s innate immune cells, microglia, will be used to test combinations of phytonutrient components in normal aging and neuropathological models (i.e. Parkinson’s disease in the proposed studies here). Exosome microvesicles isolated from these assays are used as sensitive biomarkers for gene and protein expression patterns in interactive anti-inflammatory, neurogenic, and cell survival networks. Phytonutrient screening along with molecular and behavioral findings from cell culture, in vivo xenotransplantation, and human studies will establish phytonutrient effects that help counter neurodegeneration.
Progress Report
Progress was made on Objective 1 and its sub-objectives, as well as Sub-Objective 2a, which fall under NP107, Human Nutrition.
Under Sub-Objective 1a, all cell lines needed for in vitro and in vivo studies proposed in the plan are established. Specifically, adult human neuronal progenitor cells (AHNPs) derived from various areas of human brains were used as in vitro assays for treatments and evaluations. Rodent primary neurons and microglial cell lines were also established for similar studies. Human Induced Pluripotent Stem Cells (hiPSCs) are established and maintained in the lab for proposed in vivo xenograft studies (Sub-Objective 1b). For this reporting period, we studied the effects of various treatments on cell survival and differentiation and the potential cellular and molecular mechanisms underlying these effects. Our data indicated that blueberry and polymolecular botanical compound (PBC) treatments have beneficial effects on the survival and proliferation of the human hippocampal AHNPs, especially under stressed conditions. Additionally, our preliminary data also suggested that cellular stress increases the expression levels of certain oxidative stress and inflammation markers in hippocampal AHNPs, and that blueberry treatment can decrease their expression levels. Evaluation of other related markers and pathways on normal and patient-derived AHNPs is underway, and a manuscript associated with this study is being prepared for submission.
Under Sub-Objective 1b, control hIPSCs proposed to be used as donor cells for the xenograft study were established and characterized. The human neural stem/progenitor cell xenograft model was also established, and baseline information related to the survival and differentiation of the donor cells was obtained for future comparison with xenografted animals undergoing diet treatments. A manuscript for the evaluation of this model is being prepared for publication. Institutional Animal Care and Use Committee (IACUC) protocols are being prepared for the follow-up treatment studies on xenografted animals.
Under Sub-Objective 1c, we continued to analyze the results from our experiment to assess the association of neuro-available blueberry metabolites with motor and cognitive alterations following continuous or intermittent wild blueberry supplementation in old rats. This study was designed to assess whether the optimal intake of blueberries is continuous or intermittent consumption. For this reporting period, we analyzed inflammatory biomarkers in the serum of aged rats fed either a continuous control diet, a continuous 2% blueberry diet, or intermittent 2% blueberry diet for 7-8 weeks before testing on a battery of age-sensitive tests and subsequent serum collection. Continuous or intermittent feeding of wild blueberries had beneficial effects by reducing the inflammatory stress signals of cyclooxygenase-2 (COX-2) and inducible nitrous oxide synthase (iNOS), but only continuous feeding attenuated nitrite production.
In support of Sub-Objective 1d, we completed study participation in a multi-center, double-blind, placebo-controlled, crossover study in older (55-70 year-old), overweight/obese (BMI 27-35) adults to study the effects of acute raspberry intake on the relationship between enhanced metabolic control and cognitive and psychomotor function. This project collaborates with Dr. Britt-Burton Freeman at the Illinois Institute of Technology (ITT) in Chicago. This project aims to determine whether restoring meal-induced metabolic/inflammatory balance via supplementation with red raspberries results in improved cognitive performance in humans. Further, we are interested in determining if the expected enhancements are mediated through improvements in vascular function. We were able to complete collecting data on 6 participants at the Human Nutrition Research Center on Aging (HNRCA) before the pandemic shut down human intervention studies, but ITT was able to complete 30 participants. Therefore, we decided to end study participation because we do not know what impact the pandemic will have on cognition among older adults due to the stresses (e.g., social isolation, illness, etc.) they may have experienced in the last year. For this reason, it is not advisable to restart the study because the baseline cognitive data in the new participants may be different. The new data could not be combined with the data collected before the pandemic. Because we have enough power with the current participants, we decided to end enrollment and analyze the data.
Under Sub-Objective 2a, adult human neuronal progenitor cells (AHNPs) derived from midbrain or substantia nigra (SN) of Parkinson’s disease (PD) patients were established and characterized. These cells are being used as in vitro assays for follow-up treatments and evaluations. Treatment studies using PBC and blueberries are ongoing. Human Induced Pluripotent Stem Cells (hiPSCs) obtained from PD patients with familial mutations, including patients with the G2019S LRRK2 mutation, are currently maintained in the lab for proposed in vivo xenograft studies (Sub-Objective 2b).
Accomplishments
Review Publications
Rutledge, G.A., Sandhu, A.K., Miller, M.G., Edirisinghe, I., Burton-Freeman, B.B., Shukitt Hale, B. 2020. Blueberry phenolics are associated with cognitive enhancement in healthy supplemented older adults. Food and Function. 12:107-118. https://doi.org/10.1039/D0FO02125C.
Cahoon, D., Shukitt Hale, B., Bielinski, D.F., Hawkins, E.M., Cacioppo, A.M., Rabin, B.M. 2020. Effects of partial or whole-body exposures to 56Fe particles on brain function and cognitive performance in rats. Life Sciences in Space Research. 27:56-63. https://doi.org/10.1016/j.lssr.2020.07.006.
