Porphyromonas gingivalis Participates in Pathogenesis of Human Abdominal Aortic Aneurysm by Neutrophil Activation. Proof of Concept in Rats

International audienceBACKGROUND: Abdominal Aortic Aneurysms (AAAs) represent a particular form of atherothrombosis where neutrophil proteolytic activity plays a major role. We postulated that neutrophil recruitment and activation participating in AAA growth may originate in part from repeated episodes of periodontal bacteremia. METHODS AND FINDINGS: Our results show that neutrophil activation in human AAA was associated with Neutrophil Extracellular Trap (NET) formation in the IntraLuminal Thrombus, leading to the release of cell-free DNA. Human AAA samples were shown to contain bacterial DNA with high frequency (11/16), and in particular that of Porphyromonas gingivalis (Pg), the most prevalent pathogen involved in chronic periodontitis, a common form of periodontal disease. Both DNA reflecting the presence of NETs and antibodies to Pg were found to be increased in plasma of patients with AAA. Using a rat model of AAA, we demonstrated that repeated injection of Pg fostered aneurysm development, associated with pathological characteristics similar to those observed in humans, such as the persistence of a neutrophil-rich luminal thrombus, not observed in saline-injected rats in which a healing process was observed. CONCLUSIONS: Thus, the control of periodontal disease may represent a therapeutic target to limit human AAA progression

L' implication des polynucléaires neutrophiles dans le développement et la rupture des anévrysmes expérimentaux de l'aorte

PARIS7-Bibliothèque centrale (751132105) / SudocSudocFranceF

Applicabilité et résultats du traitement par endoprothèse des urgences aortiques thoraciques

PARIS7-Xavier Bichat (751182101) / SudocSudocFranceF

Economic impacts of treatment for type II or III thoracoabdominal aortic aneurysm in the United States

Background: Current treatment for extensive thoracoabdominal aortic aneurysms (TAAAs) involves high-risk surgical and endovascular repairs, with a hospital mortality exceeding 20%, and a postoperative paraplegia rate beyond 10.5%. Objectives: The aim of this study was to present an estimation of the economic impacts of surgical and endovascular treatments of types II and III TAAAs in the US as well as the economic consequences of the elimination of spinal cord injury and mortality via an endovascular repair of extensive TAAAs (1). Materials and Methods: We compared the current hospital charges of endovascular and surgical repair of extensive TAAAs, also provided a cost analysis of health care charges resulting from paraplegia in the United States, and determined the prevalence of extensive TAAAs found yearly during autopsies in the U.S. Based on the figures gathered and the frequency of Thoracic Aortic Aneurysms per year, we were able to calculate the nationwide inpatient hospital charges, the total average expenses affected by paraplegia during the first 12 months after the repair, the total average expenses after paraplegia for each subsequent year, mortality rate at 30 days and one year, and the number of extensive TAAAs ruptures. Results: The current nationwide inpatient hospital charges for type II or III TAAA repair cost $12484324 and$37612665 for endovascular repair and surgical repair respectively, and the total average expenses for patients affected by paraplegia during the first 12-month were $4882291 and$23179110 after endovascular repair and surgical repair respectively. The nationwide average expense after 10 years for patients undergoing surgical repair and affected by paraplegia is $33421910 and$6,316,183 for patients undergoing endovascular repair. Moreover, 55 patients with a type II or type III TAAA died after 30 days, and 100 after 1 year. The potential risk of type II or III TAAA ruptures is totally 1637 in a year. Conclusions: Major economic impacts of type II or III TAAA repairs in the United States have been identified. An endovascular repair excluding spinal cord injury and mortality with the same average costs as present endovascular treatments makes it possible to save at least $53189742 after one year, 100 lives of operated patients would be saved after one year, and 1637 type II and III TAAA ruptures would be avoided yearly

Fucoidan interferes with Porphyromonas gingivalis-induced aneurysm enlargement by decreasing neutrophil activation

PurposeNeutrophils have been shown to be involved in all stages of human and experimental abdominal aortic aneurysm (AAA) development. The initial processes of neutrophil rolling and trapping in the intraluminal thrombus (ILT) are mediated mainly by P-selectin expressed by activated platelets. In the present study, we propose to evaluate the beneficial effect of fucoidan, a competitive binding agent of P-selectin, on aneurysmal growth in a rat model of aortic aneurysm with neutrophil enrichment of the ILT induced by repeated episodes of weak bacteremia.MethodsSixty Lewis rats with experimental AAAs, developed from decellularized aortic xenografts, were divided into four groups. Two groups were used as controls: group fucoidan control (FC) was treated with 200 mg of fucoidan (F) delivered by 2 mL, 4-week osmotic pumps placed intraperitoneally before closing the abdomen, and group C received saline instead of fucoidan. Two more groups were injected weekly with Porphyromonas gingivalis (P. gingivalis [Pg]): group F+Pg received 200 mg of intraperitoneal fucoidan and group Pg received saline. AAAs were harvested after 4 weeks and peripheral blood was sampled at that time. Cell-free DNA (cf-DNA) and myeloperoxydase (MPO) antigen concentrations were determined in plasma and in AAA-conditioned media. Histology and P-selectin immunostaining were performed on AAA tissue samples.ResultsComparing rats injected with Pg, those receiving fucoidan presented reduced aneurysmal diameter. Histologic analysis of AAAs showed that fucoidan reduced the ILT thickness in Pg-injected rats, with fewer trapped neutrophils, and with signs of a healing process, as observed in control group C. Immunohistological analysis revealed a substantial decrease in P-selectin immunostaining at the luminal surface of aneurysms in fucoidan-treated rats compared to the other groups, suggesting an interaction between fucoidan and P-selectin. A significant decrease in MPO concentrations in both plasma and conditioned medium was induced by fucoidan treatment in Pg-injected rats, reflecting a pacification of the ILT biological activity. This effect was associated with a reduction in neutrophil activation and apoptosis, reflected by a significant decrease in cf-DNA concentration in both plasma and conditioned medium of fucoidan-treated rats.ConclusionsOur results suggest that fucoidan has a beneficial effect on experimental aneurysmal degeneration by decreasing neutrophil activation in the ILT enhanced by weak pathogen contamination. This effect seems to be related to its interaction with P-selectin, which may decrease the trapping of neutrophils into the ILT. Fucoidan could represent a therapeutic option in AAAs to decrease the neutrophil activation involved in the degenerative process of aneurysmal expansion and rupture.Clinical RelevanceIn the present study, we propose to evaluate the beneficial effect of fucoidan, a competitive binding agent of P-selectin, on aneurysmal growth in a rat model of aortic aneurysm with neutrophil enrichment of the intraluminal thrombus induced by repeated episodes of weak bacteremia. Our results suggest that fucoidan has a beneficial effect on experimental aneurysmal degeneration enhanced by weak pathogen contamination by decreasing the trapping of neutrophils and the release of proteolytic enzymes into the intraluminal thrombus. Fucoidan could, therefore, represent a therapeutic option in abdominal aortic aneurysm to decrease the degenerative process leading to aneurysmal expansion and rupture