UC Irvine

The heart and esophagus are two of many organs in the body that rely on tissue organization to function properly. For both, in the disease states, cytoskeletal structure is often compromised, leading to major complications. To better understand both healthy and diseased states in the heart and esophagus, this thesis quantified the structural organization of various cytoskeletal components. For the heart, the effect of the LMNA gene mutation on nuclei, sarcomere, and actin organization was elucidated using induced pluripotent stem cell (iPSC) derived cardiomyocytes from both patients and controls. There was significance in sarcomere organization between control and patient cell lines, but no significance was found with the orientation in actin fibrils. Additionally, it was concluded that there is no significant difference in the means of the percentages of dysmorphic nuclei between patient and control lines. To study esophageal structure, tissue sections were harvested from a porcine model and were stained for slow skeletal myosin heavy chain (SMHC) as well as sarcomeric z-lines. When quantifying the organization of SMHCs and z-lines in tissue sections sliced perpendicular to the lumen, it was determined that there is a significant difference between the esophageal regions. However, there was no significant difference between the z-line orientation in the two esophageal regions for the longitudinally sliced tissue. Overall, studies showed that important quantitative metrics can be evaluated to reveal how these organs function.