Role of interleukin‐1 and prostaglandin in in vitro bone resorption induced by Actinobacillus actinomycetemcomitans lipopolysaccharide

Abstract

Lipopolysaccharide (Y4 LPS) isolated from Actinobacillus actinomycetemcomitans strain Y4 induced bone resorption in BALB/c mouse calvaria organ culture. The calcium release from LPS-low responsive C3H/HeJ mouse calvaria by Y4 LPS was very low. Indomethacin almost completely inhibited prostaglandin E2 (PGE2) production by Y4 LPS-stimulated BALB/c mouse calvaria, but did not suppress interleukin-1 (IL-1) release from the calvaria, and partially suppressed the bone resorption. Dexamethasone strongly inhibited the PGE2 and IL-1 production by Y4 LPS-stimulated BALB/c mouse calvaria, as well as Y4 LPS-induced bone resorption. Dexamethasone inhibited expression of membrane IL-1 on osteoblastic cells stimulated with Y4 LPS, but indomethacin did not. Furthermore, anti-IL-1 serum partially suppressed the calcium release from Y4 LPS-stimulated BALB/c mouse calvaria. These results suggest that both PGE2 and IL-1 participate in Y4 LPS-induced bone resorption in vitro.

Gene Expression of Osteoclast Differentiation Factor Is Induced by Lipopolysaccharide in Mouse Osteoblasts Via Toll-Like Receptors

“…In addition, IL-1 and TNF-␣ also up-regulated expression of ODF gene in osteoblasts (13,14). Because LPS has been shown to stimulate osteoblasts to secrete the osteolytic factors IL-1 (28), IL-6 (41), TNF-␣ (29), and PGE (30), it is reasonable to presume that ODF gene expression by LPS may be indirectly mediated by one of these factors. However, in the present study, we have demonstrated that a potent protein synthesis inhibitor, cycloheximide, rather enhances synthetic lipid Amediated increase of ODF mRNA ( Fig.…”

“…LPS stimulates osteoblasts to secrete osteolytic factors, IL-1␤ (28), TNF-␣ (29), and PGE 2 (30). Each of these factors is also a known inducer of ODF from osteoblasts (11,13,14).…”

The Effects of Different Extract of LepidiumSativum on Induced Periodontitis in Dexamethasone Immunosuppressed Rats

“…(17) Fernandeset al (18) compared the histometric and morphometric methods and found that both are capable of detecting alveolar bone loss in rats. Li and Amar (19) likewise compared the different methods-morphometric isolated, histometric and morphometric associated and micro-computed tomography-in 100 male rats, and their findings showed that all the methods are accurate for quantification of alveolar bone loss (20) .The histological results of the present study revealed that in control ligature group lack of normal architechture of periodontal ligament (PDL), resorptive bays on bone detachment associatedwith PDL detachment in certain areas, In vehicle group, total degeneration of PDL, lack of normal architecture of PDL and resorptive bone area, Using watery extract of lepiduimsativum, at 15 days there were gradual healing of PDL with marked reduction in marrow spaces numbers, completebone attachment, while in 30 days, almost complete regeneration of PDL and reversal lines are observed. Normal bone trabeculae, In methanol 15 group there were minimal loss of PDL, periodontal fibers showed some degree of well orientation, while in 30 days best healing was seen (good architecture of PDL) and PDL fibers are well arranged.…”

Two different types of humoral immune response to Actinobacillus actinomycetemcomitans in high-responder periodontitis patients

“…LPS from A. actinomycetemcomitans has a broad spectrum of immunobiological and endotoxin activities, including mitogenic and polyclonal responses of B lymphocytes, macrophage activation and induction of IL-1 and prostaglandin E2 [8]. Also, the LPS is considered to be a potent mediator of alveolar bone resorption, which is one of the major features of periodontitis [5]. The high levels of anti-LPS antibody in group 2 patients may be effective in inhibiting immunological activity and preventing the progression of periodontitis.…”