Auburn Research Day 2022

Shelby C. Osburn, Paulo H.C. Mesquita, Frances K. Neal, Bradley A. Ruple, Matthew T. Holmes, Michael D. Roberts Auburn University, School of Kinesiology 7 B i omed i ca l Resea rch | Gr adua te/Undergr adua te St udent Skeletal Muscle Line-1 Gene Regulation and Inflammatory Response to Chronic, Voluntary Endurance Training in Rodents

Objective: We sought to determine the effects of chronic, voluntary wheel running on Long Interspersed Nuclear Element-1 (LINE-1) mRNA expression and promoter methylation, as well as markers of the cGAS-STING inflammatory pathway, in skeletal muscle. Hypotheses: LINE-1 mRNA expression will increase with age, and exercise will mitigate this increase. This difference in expression will be driven through changes in promoter methylation. The cGAS- STING inflammatory pathway will be upregulated with age and downregulated with rats that exercise-trained. Methods: Plantaris and soleus skeletal muscles were collected from female Lewis rats that belonged to one of three groups: a young control group (CTL; n=10; 6 mos old), an aged sedentary group (SED; n=12; 15 mos old), and an aged exercise group with access to a running wheel for 9 months (EX; n=12; 15 mos old). RNA, DNA, and protein were isolated from the tissues for analysis. Analysis included RT-qPCR for LINE-1 mRNA expression, methylated DNA Immunoprecipitation (MeDIP) to assess the methylation status of the LINE-1 promoter via RT-qPCR, and Western blotting for markers of the cGAS-STING pathway and 4Hydroxynonenal (4HNE). Two primer sets were used for RT-qPCR: L1-3 probed for the most active form of LINE-1 and L1-Tot probed for all full-length LINE-1 elements.

Results: There was no significant difference in plantaris LINE-1 mRNA expression or for L1-3 or L1-Tot. Plantaris LINE-1 promoter methylation was undetectable in most samples, so the results are not presented herein. Soleus L1-3 mRNA was significantly higher in EX compared to CTL (p=0.036) and there was a trend between SED and EX (p=0.053). L1-Tot also was trending (p=0.059), where EX was higher than CTL (p=0.025). Methylation of the LINE-1 promoter was significantly different for both L1-3 and L1-Tot (p=0.021 and p=0.028, respectively). In both instances, LINE-1 DNA in SED and EX were significantly more methylated compared to CTL. There were no differences in cGAS protein expression, p-/pan STING protein expression, or 4HNE expression. Conclusions: Contrary to the original hypothesis, LINE-1 mRNA expression and DNA methylation were higher in the exercise group. Additionally, chronic exercise did not affect the cGAS-STING inflammatory pathway, highlighting this pathway may be more relevant in extreme age and disease states. Previous skeletal muscle research has focused on using mixed muscle types to look at LINE-1 expression and regulation, so the differences seen between type I (soleus) and type II (plantaris) fibers is a novel finding that warrants further investigation to understand the underlying mechanisms.

Cl i n i ca l Resea rch | Med i ca l St udent Clinical Outcomes of Behavioral Activation Therapy: Actigraphy and Mood

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Nora Rady, OMS I; Susannah Murphy, PhD VCOM-Louisiana Campus; Psychopharmacology and Emotion Research Laboratory, Department of Psychiatry, University of Oxford, United Kingdom

Objective: Behavioral Activation therapy (BA) is an effective treatment for depression and relies upon the practice of increasing engagement in activities promoting positive mood. The mechanism by which BA works to improve mood is not well understood. The study uses an objective measure of activity (actigraphy) to investigate whether BA increases motor activity and whether this is related to clinical improvements in mood. The study included an active control group, which allowed the isolation of the key active ingredients of the intervention in order to provide a mechanistic account of the role of daily activity in the clinical effects of BA. Methods: The study consisted of sixty-five participants each allocated to one of three groups. Those in the BA and active control groups underwent a 4-week intervention (divided into 3 blocks) of either BA or an “Activity Monitoring” intervention respectively while those in the control group received no intervention. Results: Both the BA and active control group displayed an improvement in mood via the Behavioral Activation for Depression (BADS) score and decrease in depression symptomology at the end of the study, while the control displayed no change. However, only

the BA group displayed an increase in diurnal motor activity (M10) while the active control and control groups displayed no change in M10. The BA group displayed an association between M10 and level of mood (p=.005, r=.45). Conclusion: An increase in diurnal motor activity may be a key moderator of the effect of BA on mood. Note: The entire study is from the University of Oxford and has been ongoing since 2018, it is a PhD student's study and I was part of both data collection and analysis during my time at the University of Oxford. My poster represents a subset of the data that was collected and analyzed by me however, the study was still ongoing up until recently (data collection ended September 2021). Since then and during this winter break (2021) I was assisting the PhD student with troubleshooting in her analysis of the data but I am not currently a part of the study since I graduated in November 2020. The data that I submitted in my abstract was my own work and I was really hoping to be able to present it at the student forum.

11 2022 Via Research Recognit ion Day