2022 VCOM Research Retreat Program

Abstracts

Increased IL-6, but not TNF-α Release, In Response to Post Alcohol Consumption Occurs in Binge Drinkers But Not Social Drinkers Presenter: Darren Beck, PhD Co-Authors: Sara K. Blaine, PhD; Clayton M. Ridner; Benjamin R. Campbell; Eric D. Claus, PhD; Juliet R. Wilson*; Summer N. West*; Austin J. McClanahan*; Anna S. Siddiq*; Isaak M.P. Layman*; Emily B. Ansell, PhD; Jennifer L Robinson, PhD Objective and Design: Preclinical and clinical studies suggest learned neuroimmune system responses to alcohol cues and consumption may contribute to alcohol’s pharmacodynamic properties and/or Alcohol Use Disorder (AUD) pathogenesis. Mechanistically, these neuroimmune alterations may be associated with increased craving during alcohol consumption both acutely and over time. We sought to characterize this relationship in a randomized, counter-balanced, crossover experiment. Methods: Thirty-three binge drinkers (BD) and 31 non-binge, social drinkers (SD), matched for demographic and psychological variables, were exposed to alcohol cues and water cues. Each exposure was followed by the Alcohol Taste Test (ATT) of implicit motivation for alcohol to examine acute effects of cues, and a post-experiment one-month prospective measurement of their “real world” drinking behavior to approximate chronic effects. Blood plasma and craving measures were collected repeatedly to examine the effects of alcohol cues and alcohol consumption on Tumor necrosis factor alpha (TNF-α) and Interleukin 6 (IL-6) levels. Results: BD demonstrated significantly higher craving when compared to SD in response to alcohol cues, while group differences in IL-6 cue responses were not significant. Greater ATT consumption in BD was positively associated with alcohol cue-induced craving and IL-6 release post alcohol consumption. Additionally, craving post alcohol consumption and IL-6 release in response to alcohol consumption were each independently related to the number of drinks consumed in the next month for BD. TNF-α release to alcohol cues and consumption was not related to craving, IL-6 levels, immediate alcohol consumption, or future alcohol consumption. Conclusions: BD show greater alcohol craving and IL-6 release to acute alcohol consumption when compared to SD. Trial registration: Clinical Trials NCT04412824. Funding: National Institutes of Health grant R00-AA025401(SKB). Rationale: Pneumonia is a leading cause of acute respiratory distress syndrome and sepsis. Despite the resolution of active infection, pro-inflammatory mediators and cytotoxins elicited during the acute phase promote secondary tissue injury, impede recovery, and contribute to poor patient prognoses. Acute lung infection with Pseudomonas aeruginosa, Klebsiella pneumoniae, and influenza elicit pathogenic lung amyloids that propagate injury and likely contribute to the inflammatory milieu. However, clinical trials targeting amyloid-beta (Aβ) have consistently failed. Lung endothelial-derived amyloids have been implicated as innate antimicrobials yet the contribution of Aβ to the defense of the air-blood barrier remains poorly resolved. Here, we tested whether lung endothelial Aβ contributes to 1) the attenuation of active infection, and 2) endothelial barrier resilience to infection. Methods: CRISPR/Cas9 was targeted to Aβ precursor protein (APP) in rat pulmonary microvascular endothelial cells (PMVECs), and the deletion was confirmed via PCR, sequencing, and immunoblotting. The contribution of APP expression to cell proliferation, self-replication, wound closure, angiogenesis, and barrier integrity both at baseline and during virulent infection was assessed in WT, guide RNA control, and APP-/- PMVECs. Amyloid content was monitored with immunoblotting and Thioflavin T staining. Antimicrobicity was measured via kinetic bactericidal assays, agglutination, and plating. Results: APP-/- cells were ~49% less effective in reducing the bacterial load of active infection as compared to APP expressing PMVECs. Immunodepletion of Aβ from cell supernatant comparably reduced bactericidal efficacy. APP-/- cells also exhibited markedly impaired proliferation and replication capacity, and little resilience to infection with loss of barrier integrity in roughly half the time of control cells. Conclusions: Lung endothelial APP is an important contributor to host defense. APP and its Aβ variant(s) appear to constrain infective bacterial burden whereas APP products appear to function as mitogens/morphogens within the microvascular milieu, likely contributing to tissue repair and recovery post-insult. Amyloid-Beta Precursor Protein: Essential to Lung Capillary Barrier Defense During Acute Infection Presenter: Sarah Voth, PhD Co-Authors: Chung-Sik Choi, PhD; Rebekah Morrow, PhD; Meredith Gwin, BS; Mike Lin, PhD; Samir Gautam, MD, PhD; Dara W. Frank, PhD; Jonathan P. Audia, PhD; Troy Stevens, Phd; Lokesh Sharma,Phd; Charles Dela Cruz, MD, PhD; K. Adam Morrow, PhD

*VCOM Student