Abstract
Objective Elastase-induced abdominal aortic aneurysm (AAA) model is widely used for aneurysmal pathogenesis and translational research. However, temporal alternations in aneurysmal histologies remain unknown. This study is aimed at analyzing temporal immunopathologies of aneurysmal aorta following experimental AAA induction. Methods Male C57BL/6J mice at the age of 10-14 weeks received intra-aortic infusion of elastase to induce AAAs. Aortic diameters at the baseline and indicated days after AAA induction were measured, and aortae were collected for histopathological analysis. Results Aorta diameters increased from 0.52 mm at the baseline levels to 0.99 mm, 1.34 mm, and 1.41 mm at days 7, 14, and 28, respectively, corresponding 90%, 158%, and 171% increases over the baseline level. Average aortic diameters did not differ between days 14 and 28. Severe elastin degradation and smooth muscle cell depletion were found at days 14 and 28 as compared to the baseline and day 7. No difference in the scores of medial elastin and SMC destruction was noted between days 14 and 28. Consistent results were found for leukocyte accumulation, neoangiogenesis, and matrix metalloproteinase expression. Twenty-eight days after AAA induction, all aneurysmal pathologies showed an attenuated trend, although most histopathological parameters did no differ between days 14 and 28. Conclusion Our data suggest that almost aneurysmal immunohistopathologies reach maximal 14 days following AAA induction. Analysis of day 14 histologies is sufficient for AAA pathogenesis and translational studies in elastase-induced mouse experimental AAAs.
Highlights
Abdominal aortic aneurysms (AAAs) are the localized dilatations of abdominal aortic segments defined as a more than 50% increase over the proximal segment or aortic diameter over 3.0 cm [1,2,3]
No further significant increase in aortic diameter was observed on day 28 as compared to those on day 14 (Figures 1(c)– 1(e)). These results suggest that aortic expansion induced by porcine pancreatic elastase (PPE) infusion reaches the plateau on day 14 after AAA induction
Similar results was found for smooth muscle cell (SMC) depletion, with the scores of 4 (3–4) and 3.5 (3–4) for days 14 and 28, respectively, again without differences between two time points (Figures 2 and 3(b)). These results suggested that, consistent with aortic enlargement, medial elastin degradation and SMC depletion achieved maximal 14 days after AAA induction
Summary
Abdominal aortic aneurysms (AAAs) are the localized dilatations of abdominal aortic segments defined as a more than 50% increase over the proximal segment or aortic diameter over 3.0 cm [1,2,3]. Histological examinations have been limited to one time point analysis such as day 14 or day 28 following AAA induction [9, 16,17,18]. It is not known whether one time point analysis at day 14 or 28 represents characteristics of AAA pathologies. It warrants temporal analysis of aneurysmal histopathologies for better understanding of AAA pathogenesis and translational studies
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
