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OR21 - Degradation of Kininogen and Fibrinogen by Porphyromonas Endodontalis

Wednesday, May 3, 2023

1:30 PM – 1:45 PM CT

Location: E353B (Level 3)

Presenter(s)

HJ

Hoonji Jang, D.D.S., M.S.

Resident
Temple University
Philadelphia, Pennsylvania

Disclosure information not submitted.

Co-Author(s)

CY

Cemil Yesilsoy, D.M.D., M.S.

Deputy Chair of Department of Endodontics
Temple University
Philadelphia, Pennsylvania

Disclosure information not submitted.
RN

Roni Nissan, D.M.D.

Associate Professor
Temple University
Philadelphia, Pennsylvania

Disclosure information not submitted.
MY

Maobin Yang, D.M.D., M.D.S., Ph.D.

Director of the postdoctoral endodontic program
Temple University
Philadelphia, Pennsylvania

Disclosure information not submitted.
EW

Eugene J. Whitaker, D.M.D., Ph.D.

Associate Professor Emeritus, Clinical Associate Professor
Temple University
Philadelphia, Pennsylvania

Disclosure information not submitted.

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Objectives: Kininogen and fibrinogen are precursor proteins for kinin and fibrin. Studies have suggested that endodontic bacteria may cause degradation of kininogen and fibrinogen. The objective of this research is to determine significant in vitro interaction between these plasma proteins and the endodontic pathogen Porphyromonas endodontalis.

Methods: Sonic extracts (1mg/ml) of the endodontic pathogens P. endodontalis, Enterococcus faecalis, and Fusobacterium nucleatum were incubated with low molecular weight kininogen (LMWK) (0.1mg/ml) and fibrinogen (0.1mg/ml) for 1 hr, 4 hr and 24 hr at 37°C. Degradation of these proteins was detected by polyacrylamide gel electrophoresis (PAGE). Kininognease activity was assayed by incubating sonic extracts (30 ml, 1 mg/ml) with either chromogenic amide substrate N-benzoyl-pro-phe-arg-pNA (70 ml, 7 mm, 15-60 min) or LMWK (70 ml, 0.1 mg/ml, 10-3 mm, 60 min). Release of pNA was determined spectrophotometrically and release of bradykinin from kininogen was measured by a competitive enzyme-linked immunosorbent assay (ELISA) (Enzo Life Sciences).

Results: P. endodontalis sonic extract (PESE) degraded both kininogen and fibrinogen as evidenced by PAGE (n=10,100% interoperator agreement). Sonic extracts of E. faecalis and F. nucleatum did not exhibit this activity. PESE also cleaved the protease substrate at the arginine residue releasing pNA linearly (n=2; m = 0.77mmole/min). Bradykinin (n=2, m=100pg/ml) was released from LMWK when incubated with PGSE for 60 min.

Conclusion: PESE degrades both kininogen and fibrinogen in vitro. These data suggest that P. endodontalis may contribute to the pathogenesis of pulpitis and periodontitis by modulating the inflammatory response via its effect on LMWK as well as hemostasis by its ability to degrade fibrinogen.