title: Older Age Results in Differential Gene Expression after Mild Traumatic Brain Injury and Is Linked to Imaging Differences at Acute Follow-up.
abstract: Older age consistently relates to a lesser ability to fully recover from a traumatic brain injury (TBI); however, there is limited data to explicate the nature of age-related risks. This study was undertaken to determine the relationship of age on gene-activity following a TBI, and how this biomarker relates to changes in neuroimaging findings. A young group (between the ages of 19 and 35 years), and an old group (between the ages of 60 and 89 years) were compared on global gene-activity within 48 h following a TBI, and then at follow-up within 1-week. At each time-point, gene expression profiles, and imaging findings from both magnetic resonance imaging (MRI) and computed tomography were obtained and compared. The young group was found to have greater gene expression of inflammatory regulatory genes at 48 h and 1-week in genes such as basic leucine zipper transcription factor 2 (BACH2), leucine-rich repeat neuronal 3 (LRRN3), and lymphoid enhancer-binding factor 1 (LEF1) compared to the old group. In the old group, there was increased activity in genes within S100 family, including calcium binding protein P (S100P) and S100 calcium binding protein A8 (S100A8), which previous studies have linked to poor recovery from TBI. The old group also had reduced activity of the noggin (NOG) gene, which is a member of the transforming growth factor-β superfamily and is linked to neurorecovery and neuroregeneration compared to the young group. We link these gene expression findings that were validated to neuroimaging, reporting that in the old group with a MRI finding of TBI-related damage, there was a lesser likelihood to then have a negative MRI finding at follow-up compared to the young group. Together, these data indicate that age impacts gene activity following a TBI, and suggest that this differential activity related to immune regulation and neurorecovery contributes to a lesser likelihood of neuronal recovery in older patients as indicated through neuroimaging.
authors.affiliation: National Institute of Nursing Research, National Institutes of Health, Bethesda MD, USA.
authors.forename: Young-Eun
authors.initials: YE
authors.lastname: Cho
authors.affiliation: National Institute of Neurological Disorders, National Institutes of Health, Bethesda MD, USA.
authors.forename: Lawrence L
authors.initials: LL
authors.lastname: Latour
authors.affiliation: National Institute of Nursing Research, National Institutes of Health, Bethesda MD, USA.
authors.forename: Hyungsuk
authors.initials: H
authors.lastname: Kim
authors.affiliation: National Institute of Neurological Disorders, National Institutes of Health, Bethesda MD, USA.
authors.forename: L Christine
authors.initials: LC
authors.lastname: Turtzo
authors.affiliation: National Institute of Nursing Research, National Institutes of Health, Bethesda MD, USA.
authors.forename: Anlys
authors.initials: A
authors.lastname: Olivera
authors.affiliation: National Institute of Nursing Research, National Institutes of Health, Bethesda MD, USA.
authors.forename: Whitney S
authors.initials: WS
authors.lastname: Livingston
authors.affiliation: National Institute of Nursing Research, National Institutes of Health, Bethesda MD, USA.
authors.forename: Dan
authors.initials: D
authors.lastname: Wang
authors.affiliation: National Institute of Nursing Research, National Institutes of Health, Bethesda MD, USA.
authors.forename: Christiana
authors.initials: C
authors.lastname: Martin
authors.affiliation: National Institute of Nursing Research, National Institutes of Health, Bethesda MD, USA.
authors.forename: Chen
authors.initials: C
authors.lastname: Lai
authors.affiliation: National Institute of Nursing Research, National Institutes of Health, Bethesda MD, USA.
authors.forename: Ann
authors.initials: A
authors.lastname: Cashion
authors.affiliation: National Institute of Nursing Research, National Institutes of Health, Bethesda MD, USA.
authors.forename: Jessica
authors.initials: J
authors.lastname: Gill
keywords: aging; gene expression; imaging; inflammation; traumatic brain injury