Interaction Of Platelet Factor 4 And Tumor Necrosis Factor-α In The Pathogenesis Of Periodontitis

Periodontitis,also known as destructive periodontal disease,is a chronic inflammation caused by the invasion of periodontal tissue by bacteria in dental plaque,which can lead to the destruction of periodontal support tissues(gingiva,periodontal membrane,alveolar bone and cementum),the formation of periodontal pockets,loss of attachment and absorption of alveolar bone.As the disease progresses,teeth will slowly loosen,and gingival recession can eventually lead to tooth loss.Platelets are small circulating blood cells that store and release a large number of proinflammatory cytokines.The proinflammatory effect of platelets may be attributed to Platelet factor 4(PF4),which is a 7.8 kDa cytokine,accounting for α The majority of particle content acts by promoting neutrophil chemotaxis and activation,as well as by inducing monocytes to produce cytokines.Therefore,PF4 is involved in the pathogenesis of many chronic inflammatory diseases,including atherosclerosis.Therefore,people also speculate that PF4 may be associated with the pathogenesis of chronic periodontitis.Tumor Necrosis Factor-α(TNF-α)It is a cytokine that promotes neutrophil phagocytosis and invasion of bacteria,and is one of the main markers of various bacterial inflammations.Currently,PF4 and TNF-α The interaction in the pathogenesis of periodontal disease is not clear.This study explores PF4 and TNF-α The interaction in periodontitis and providing certain assistance for clinical treatment of periodontitis.Objective:In this study,the concentration changes of PF4 and TNF-α in gingival crevicular fluid and serum of patients before and after periodontal basic treatment were measured by enzyma-linked immunosorbent assay(ELISA),and the secretion of PF4 in platelets in whole blood before and after treatment stimulated by lipopolysaccharide(LPS)of porphyromonas gingivalis.To explore the interaction between PF4 and TNF-α in the pathogenesis of periodontitis.Methods:Patients with periodontitis who were treated in the Periodontal Department of the Affiliated Stomatological Hospital of Nanchang University were recruited as the research subjects,including 29 patients with stage Ⅱ,grade B periodontitis(GPⅡ-B)and 24 patients with stage Ⅲ,grade B periodontitis(GPⅢ-B).At the same time,23 healthy volunteers with normal periodontal conditions,who were employees or students of the Affiliated Stomatological Hospital of Nanchang University,were recruited as the control group.Gingival crevicular fluid and blood samples were collected from all participants for further experiments.1.Four parameters,including probing depth(PD),bleeding index(BI),clinical attachment level(CAL),and plaque index(PLI),were used to evaluate the efficacy of periodontal treatment.2.Enzyme-linked immunosorbent assay(ELISA)was used to detect changes in the concentrations of platelet factor 4(PF4)and tumor necrosis factor-alpha(TNF-α)in gingival crevicular fluid before and after periodontal treatment.3.Peripheral blood samples were collected from 22 individuals with periodontal health,22 patients with GPII-B,and 22 patients with GPIII-B to observe changes in the levels of circulating PF4 and TNF-α before and after periodontal treatment.4.Gingival crevicular fluid samples were collected from 22 individuals with periodontal health,22 patients with GPII-B,and 22 patients with GPIII-B.Microscopic platelet counts were performed using flow cytometry with single staining of CD45 and dual staining of CD41/CD61 to detect the number of platelets in the gingival crevicular fluid.5.Platelets from peripheral blood were treated with lipopolysaccharides(LPS)from Porphyromonas gingivalis for 30 minutes before and after periodontal treatment.The levels of PF4 secreted by platelets before and after LPS stimulation were measured using ELISA.Results:1.The differences in age and gender between the groups were not statistically significant after matching.The PD,CAL,and PLI of the healthy group,GPⅡ-B group before treatment,and the GPⅢ-B group before treatment were significantly different in pairwise comparisons with p<0.05.The BI of the GPⅡ-B group before treatment and the GPⅢ-B group before treatment were significantly different from that of the periodontally healthy group with p<0.05.In addition,the PD,BI,CAL,and PLI of the GPⅡ-B and GPⅢ-B treatment groups after treatment were significantly different from those of their respective groups before treatment with p<0.05.2.The levels of PF4 and TNF-α in GCF were significantly different between the GPⅡ-B group,GPⅢ-B group,and healthy group before treatment(p<0.05).The levels of PF4 and TNF-α in GCF were also significantly different between the GPⅡ-B group,GPⅢ-B group after treatment,and their respective pre-treatment groups(p<0.05).There was a significant correlation(P<0.05)between the levels of PF4 and TNF-α in GCF and the clinical parameters of PD,BI,CAL,and PLI before and after treatment in both the GPⅡ-B and GPⅢ-B groups.3.The levels of free PF4 and TNF-α in the peripheral blood of GPⅡ-B and GPⅢ-B groups before treatment were compared with those of the periodontally healthy group,and the results showed that there was a significant difference(p<0.05).Furthermore,the levels of free PF4 and TNF-α in the peripheral blood of GPⅢ-B group before and after treatment were compared,and the results showed a significant difference(p<0.05).Additionally,there was a significant difference(p<0.05)in the levels of free PF4 and TNF-α in the peripheral blood between the groups of GPⅢ-B and GPⅡ-B after treatment.4.The number of CD41/CD61 double-positive cells and CD45-negative cells in gingival crevicular fluid were compared pairwise among the healthy group,the GPⅡ-B group before treatment,and the GPⅢ-B group before treatment,and there was a significant difference with p<0.05.5.The amount of platelet-released PF4 in the blood of the healthy group,GPⅡ-B pre-treatment group,and GPⅢ-B pre-treatment group significantly increased after stimulation with Porphyromonas gingivalis LPS(P<0.05).After LPS stimulation,the amount of platelet-released PF4 in the blood of GPII-B pre-and post-treatment groups and GPⅢ-B pre-and post-treatment groups significantly increased compared to that of the healthy group(P<0.05).After LPS stimulation,the amount of platelet-released PF4 in the blood of the GPⅡ-B and GPⅢ-B pre-treatment groups significantly increased compared to that of their respective post-treatment groups(P<0.05).Conclusion:The results of this study showed that periodontitis was associated with increased platelet aggregation in gingival crevicular fluid and enhanced platelet activation in peripheral blood,and gingival crevicular fluid was associated with increased PF4 and TNF-α in peripheral blood.After perfect periodontal treatment,platelet activation could be weakened and the amount of PF4,TNF-α in gingival crevicular fluid could be reduced.PF4 and TNF-α have synergistic effect in the development of periodontitis.