Increased amount of type III pN-collagen in human abdominal aortic aneurysms: evidence for impaired type III collagen fibrillogenesis.

Abstract

PURPOSE:

This study aimed to characterize the distribution of structural domains of type I and III collagens in the wall of abdominal aortic aneurysms (AAAs), by the use of undilated atherosclerotic aortas (aortoiliac occlusive disease [AOD]) and healthy abdominal aortas as controls.

METHODS:

Immunohistochemical staining was applied with antibodies for the aminoterminal propeptides of type I (PINP) and type III (PIIINP) procollagens, which represent newly synthesized type I and III pN-collagens. In addition, an antibody against the aminoterminal telopeptide of type III collagen (IIINTP) was used as a means of detecting maturely cross-linked type III collagen fibrils.

RESULTS:

The newly synthesized type III procollagen detected by means of PIIINP staining was concentrated in the media in aneurysmal aortas, whereas type I pN-collagen was localized in the intima in both AAAs and AODs. The healthy aortas showed no immunoreactivity for either PIIINP or PINP. The cross-linked type III collagen, detected by means of IIINTP staining, stained transmurally in all study groups, but appeared more abundant in the media in AAAs.

CONCLUSION:

Our results strongly suggest that the metabolism of type III collagen is enhanced in AAAs. Intensive type III pN-collagen staining was present mainly in the media layer in AAAs, suggesting a role of type III collagen in aneurysm formation, whereas type I pN-collagen was present in the intima in both AAAs and AODs, suggesting that type I collagen synthesis is a fibroproliferative response related to the atherosclerotic process. The increased type III pN-collagen in AAAs may result in impaired fibril formation and, thus, in decreased tensile strength of aneurysmal tissue.

• Authors: M K Bode, Y Soini, J Melkko, J Satta, L Risteli, J Risteli
• Journal: Journal of vascular surgery (J Vasc Surg) Vol. 32 Issue 6 Pg. 1201-7 (Dec 2000) ISSN: 0741-5214 [Print] United States
• PMID: 11107093 (Publication Type: Comparative Study, Journal Article)

Chemical References

• Peptide Fragments
• Peptides
• Procollagen
• pN-collagen type III

Topics

• Aged
• Aneurysm, Ruptured (etiology)
• Aorta, Abdominal (metabolism, pathology)
• Aortic Aneurysm, Abdominal (etiology, metabolism, pathology)
• Aortic Diseases (metabolism, pathology)
• Arterial Occlusive Diseases (metabolism, pathology)
• Female
• Humans
• Immunohistochemistry
• Male
• Middle Aged
• Peptide Fragments (biosynthesis, immunology, metabolism, ultrastructure)
• Peptides (immunology, metabolism)
• Procollagen (biosynthesis, immunology, metabolism, ultrastructure)
• Staining and Labeling
• Tensile Strength
• Tunica Intima (metabolism, pathology)