ABSTRACTS
2019 National McNair Scholars Conference at UCLA
Researcher: Lindsey Miles
Presentation Title: Acute Vascular Changes after Volumetric Muscle Loss Injury
School: University of Minnesota
Research Focus: Muscle Physiology
Presentation Type: Poster Presentation
Volumetric muscle loss (VML) injury is the traumatic loss of skeletal muscle fibers and function, resulting in long-term disability. This loss of tissue is expected to significantly impair the vascularity of skeletal muscle after injury. To date, many approaches have been developed to target de novo muscle fiber regeneration and vascular network expansion; although only limited regeneration and functional recovery are reported. New regenerative medicine strategies using gene therapy (e.g., modified mRNA) in combination with biomedical engineering approaches (e.g., aligned collagen scaffolds) could be transformative to promote both muscle fiber and vascular regeneration. We evaluated male Lewis rats (n=15) following unilateral VML injury to the tibialis anterior (TA) muscle; the VML injury was repaired with a mmRNA-loaded (nonsense RNA) aligned collagen scaffold and evaluated at 1, 2, and 4 weeks post-VML. TA muscles were evaluated histologically by hematoxylin and eosin, Masson’s trichrome, myosin heavy chains (skeletal muscle fiber isoforms), Pax7 (skeletal muscle satellite cell), and collagen I and III to examine tissue properties in the remaining TA muscle and the VML. Additionally, vascularity was evaluated by perivascular cells (CD146/MCAM), endothelial cells (CD31), and fiber capillarity. We characterized the temporal changes in vascularity after VML injury. We hypothesized that with each subsequent time point, increased vascular generation and capillary density would be observed. Our next step is to evaluate candidate mmRNAs to co-deliver with aligned collagen scaffolds, we hypothesize that a mmRNA-incorporated aligned collagen scaffold combined with various growth factors may stimulate increased muscle fiber and vascular regeneration following VML injury.