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Updated: Jun 19, 2026
A Rat Carotid Balloon Injury Model to Test Anti-vascular Remodeling Therapeutics
Published on: September 19, 2016
DNA damage and repair in a model of rat vascular injury
Amalia Forte1, Mauto Finicelli, Mario Grossi
1Department of Experimental Medicine, Naples, Italy.
Abstract:
Restenosis rate following vascular interventions still limits their long-term success. Oxidative stress plays a relevant role in this pathophysiological phenomenon, but less attention has been devoted to its effects on DNA damage and to the subsequent mechanisms of repair. We analysed in a model of arteriotomy-induced stenosis in rat carotids the time-dependent expression of DNA damage markers and of DNA repair genes, together with the assessment of proliferation and apoptosis indexes. The expression of the oxidative DNA damage marker 7,8-dihydro-8-oxo-2'-deoxyguanosine was increased at 3 and 7 days after arteriotomy, with immunostaining distributed in the injured vascular wall and in perivascular tissue. The expression of the DNA damage marker phospho-H2A.X was less relevant but increasing from 4 hrs to 7 days after arteriotomy, with immunostaining prevalently present in the adventitia and, to a lesser extent, in medial smooth muscle cells at the injury site. RT-PCR indicated a decrease of 8 out of 12 genes of the DNA repair machinery we selected from 4 hrs to 7 days after arteriotomy with the exception of increased Muyth and Slk genes (p<0.05). Western Blot revealed a decrease of p53 and catalase at 3 days after arteriotomy (p<0.05). A maximal 7% of BrdU-positive cells in endothelium and media occurred at 7 days after arteriotomy, while the apoptotic index peaked at 3 days after injury (p<0.05). Our results highlight a persistent DNA damage presumably related to a temporary decreased expression of the DNA repair machinery and of the antioxidant enzyme catalase, playing a role in stenosis progression.
Insights
Vascular restenosis involves DNA damage and impaired repair mechanisms. Reduced DNA repair gene expression and catalase activity contribute to persistent damage, impacting stenosis progression after vascular injury.
Area of Science:
- Vascular Biology
- Molecular Biology
- Genetics
Background:
- Vascular restenosis remains a significant limitation for vascular interventions.
- Oxidative stress is implicated in restenosis, but its role in DNA damage and repair is less understood.
Purpose of the Study:
- To investigate the temporal relationship between DNA damage, repair gene expression, and cellular responses in a rat carotid arteriotomy model.
- To elucidate the contribution of oxidative DNA damage and impaired repair to vascular stenosis progression.
Main Methods:
- Analysis of oxidative DNA damage markers (7,8-dihydro-8-oxo-2'-deoxyguanosine, phospho-H2A.X) and DNA repair gene expression via RT-PCR.
- Assessment of protein levels for p53 and catalase using Western Blot.
- Evaluation of cell proliferation (BrdU incorporation) and apoptosis indexes post-arteriotomy.
Main Results:
- Increased oxidative DNA damage markers observed at 3 and 7 days post-injury.
- Downregulation of most DNA repair genes, with exceptions (Muyth, Slk), and decreased p53 and catalase expression.
- Peak cell proliferation at 7 days and apoptosis at 3 days post-arteriotomy.
Conclusions:
- Persistent DNA damage in vascular stenosis is linked to transiently reduced DNA repair machinery expression.
- Decreased expression of the antioxidant enzyme catalase may exacerbate DNA damage and contribute to restenosis progression.
- Targeting DNA repair pathways and oxidative stress could offer therapeutic strategies for vascular stenosis.
