The expression of platelet-derived growth factor and connective tissue growth factor in different types of abdominal aortic aneurysms.
OBJECTIVE
An atherosclerotic abdominal aortic aneurysms (AAAA) differ from inflammatory abdominal aortic aneurysms (IAAA), which are characterized by a non specific inflammatory reaction leading to considerable aneurysmal wall thickness from the media to adventitia and retroperitoneal fibrosis in the surrounding tissue. Platelet-derived growth factor (PDGF) and its receptor have been localized to specific cell types within atherosclerotic plaques. Human connective tissue growth factor (CTGF) is a cysteine rich polypeptide that has similar structures to PDGF and has been implicated in connective tissue formation. PDGF and CTGF may play a role in the development of aneurysmal walls in both AAAA and IAAA.


METHODS
Using in situ hybridization technique with DIG-labeled RNA probes and immunostaining, we investigated CTGF gene expression, and expression of PDGF and its receptor protein, in human aneurysmal walls.


RESULTS
Expression of CTGF mRNA was found on vascular smooth muscle cells (VSMC) in specimens from AAAA and IAAA. Strong CTGF expression was localized in VSMC around calcification in AAAA. In IAAA, strong expression of CTGF was observed around inflammatory cells. In the aneurysmal walls of AAAA, PDGF A and B chains were strongly stained on small vessels, and the PDGF beta receptor was also strongly stained on VSMC around calcification. In the aneurysmal wall of IAAA, weak expressions of PDGF A and B chains were observed in endothelial cells of vessel walls around the inflammatory cells, but the intensity of expression was much weaker than that on the vessel walls in AAAA.


CONCLUSIONS
Such differences in fibrogenic cytokine expression may be involved in characteristic aneurysmal formation.
Kanazawa
S
S
Division of Cardiovascular Surgery, Himeji Central Hospital, Himeji, Hyogo, Japan.
Miyake
T
T
Kakinuma
T
T
Tanemoto
K
K
Tsunoda
T
T
Kikuchi
K
K
D000328:Adult; D000368:Aged; D017544:Aortic Aneurysm, Abdominal / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D055513:Connective Tissue Growth Factor; D005260:Female; D015870:Gene Expression; D006801:Humans; D017874:Immediate-Early Proteins / Q000235:genetics*; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D018969:Insulin-Like Growth Factor Binding Proteins / Q000235:genetics; D036341:Intercellular Signaling Peptides and Proteins / Q000235:genetics*; D008297:Male; D009131:Muscle, Smooth, Vascular / Q000378:metabolism / Q000473:pathology; D010982:Platelet-Derived Growth Factor / Q000235:genetics*; D011379:Prognosis; D012333:RNA, Messenger / Q000235:genetics*
C526317:CCN2 protein, human; D017874:Immediate-Early Proteins; D018969:Insulin-Like Growth Factor Binding Proteins; D036341:Intercellular Signaling Peptides and Proteins; D010982:Platelet-Derived Growth Factor; D012333:RNA, Messenger; D055513:Connective Tissue Growth Factor