👤 Charles A Banks

Subjective cognitive complaints (SCC) can precede cognitive decline and are associated with demographic, exposure, lifestyle, and psychological factors. Prevalences of SCC and their correlates in individuals with repetitive head impacts (RHI) are poorly understood. This study characterized SCC in former elite American football players by frequency, mood and behavioral correlates, concordance with informant reports, and associations with neuropsychological test performance, cerebrospinal fluid (CSF), and magnetic resonance imaging (MRI) markers of neurodegeneration. Former American football players ( Rates of SCC ranged from 43 to 77% depending on the domain. Symptoms of depression, impulsivity, and anxiety were strongly associated with SCC. Self- and informant-reported SCC showed moderate inter-rater agreement. Adjusting for age, race, education, SCC are strongly associated with neuropsychiatric factors in former American football players. SCC may also be a marker of cognitive decline and neurodegeneration. Show less

Apolipoprotein E receptor 2 (apoER2), a primary receptor for apoE, has recently been linked to Alzheimer's disease. Compared with the most common form of apoE, apoE3, the apoE4 isoform increases the risk for developing Alzheimer's disease. ApoE4 impairs brain insulin signaling, a feature of Alzheimer's disease that correlates with cognitive decline. Insulin availability in the brain largely depends on blood-brain barrier (BBB) transport and contributes to brain insulin signaling. We have previously shown that the apoE4 isoform leads to regional reductions in insulin BBB transport in mice on a Western diet compared to apoE3 isoform. However, how insulin transport across the BBB is regulated by apoE isoforms is not well understood. Here we investigated a role of endothelial apoER2 in the effects of apoE isoforms on insulin BBB transport, using mice genetically expressing human apoE3 or apoE4 and expressing or lacking endothelial apoER2. We found that a loss of endothelial apoER2 did not overtly affect insulin BBB transport in either apoE3- or apoE4-expressing mice, except in the frontal cortex and pons/medulla, where decreased transport was observed in apoE3 mice lacking endothelial apoER2. These findings indicate that the effect of apoE4 on insulin BBB transport is largely independent of endothelial apoER2. In contrast, endothelial apoER2 may regulate insulin BBB transport in limited regions of the brain through its binding to apoE3. Show less

Resistance and resilience are pathways through which modifiable behaviors may reduce Alzheimer's disease (AD) risk. Sleep - a known modifiable factor - is understudied in this context, especially among older women at elevated risk for AD. Forty-five functionally intact older women (≥65 years) at heightened risk for AD completed wrist actigraphy to capture average nocturnal sleep duration. Tau positron emission tomography imaging ( Shorter sleep duration amplified the association between APOE ε4 status and tau, while longer sleep mitigated it. Similarly, tau burden was related to worse memory performance only among those with short sleep duration. Longer sleep duration may promote resistance and resilience to AD in at-risk older women, highlighting sleep as a critical intervention target. Sleep was measured via wrist actigraphy, tau via PET imaging, and memory with a composite score. Longer sleep attenuated the link between APOE ε4 carriership and tau PET across Braak regions. Greater sleep duration weakened the negative impact of tau on memory performance. This is the first study to examine sleep in AD resistance and resilience among older women at heightened risk. Show less

The tumor-suppressing function of SMAD4 is frequently subverted during mammary tumorigenesis, leading to cancer growth, invasion, and metastasis. A long-standing concept is that SMAD4 is not regulated by phosphorylation but ubiquitination. Our search for signaling pathways regulated by breast tumor kinase (BRK), a nonreceptor protein tyrosine kinase that is up-regulated in ~80% of invasive ductal breast tumors, led us to find that BRK competitively binds and phosphorylates SMAD4 and regulates transforming growth factor-β/SMAD4 signaling pathway. A constitutively active BRK (BRK-Y447F) phosphorylates SMAD4, resulting in its recognition by the ubiquitin-proteasome system, which accelerates SMAD4 degradation. Activated BRK-mediated degradation of SMAD4 is associated with the repression of tumor suppressor gene Show less

Proteins that respond to DNA damage play critical roles in normal and diseased states in human biology. Studies have suggested that the S. cerevisiae protein CMR1/YDL156w is associated with histones and is possibly associated with DNA repair and replication processes. Through a quantitative proteomic analysis of affinity purifications here we show that the human homologue of this protein, WDR76, shares multiple protein associations with the histones H2A, H2B, and H4. Furthermore, our quantitative proteomic analysis of WDR76 associated proteins demonstrated links to proteins in the DNA damage response like PARP1 and XRCC5 and heterochromatin related proteins like CBX1, CBX3, and CBX5. Co-immunoprecipitation studies validated these interactions. Next, quantitative imaging studies demonstrated that WDR76 was recruited to laser induced DNA damage immediately after induction, and we compared the recruitment of WDR76 to laser induced DNA damage to known DNA damage proteins like PARP1, XRCC5, and RPA1. In addition, WDR76 co-localizes to puncta with the heterochromatin proteins CBX1 and CBX5, which are also recruited to DNA damage but much less intensely than WDR76. This work demonstrates the chromatin and DNA damage protein associations of WDR76 and demonstrates the rapid response of WDR76 to laser induced DNA damage. Show less