Proliferation Of Periodontal Fibroblasts Research Articles

Effects of L-PRF and A-PRF+ on periodontal fibroblasts in in vitro wound healing experiments.

ObjectiveTo determine whether leukocyte‐platelet‐rich fibrin (L‐PRF) and advanced platelet‐rich fibrin (A‐PRF+) differ in their in vitro capacity to induce proliferation and migration of periodontal fibroblasts.BackgroundL‐PRF and A‐PRF + are autologous materials used in periodontal regenerative surgery. They derive from blood from patients, but have different characteristics. The literature is controversial regarding the effects of the two PRF preparations on periodontal tissue fibroblasts.Materials and methodsL‐PRF and A‐PRF + membranes were prepared from eight patients and incubated in 3 mL of culture medium for 2 days. Gingival fibroblasts (G‐F) and periodontal ligament fibroblast (PDL‐F) primary cells were retrieved from 7 donors. These cells were pre‐cultured for 1 day in wound healing experiment plates leaving a gap of 500 ± 50 µm in a concentration of 3.3 x 105 cells/mL. 70 µL of the cell suspension was placed in each half of the well. Thereafter, the pre‐cultured L‐PRF and A‐PRF + supernatants were added to the experimental plates, and the fibroblasts were incubated for another 24 h. Medium alone (NEG) and fibroblast growth factor II (FGF) were used as controls. Subsequently, cell migration was registered for 24 h with live cell imaging in a time frame microscope at 5% CO2 in air at 37°C. Images were analyzed using ImageJ. Cell proliferation and cell viability were measured.ResultsL‐PRF and A‐PRF + induced higher cell proliferation than FGF and NEG. Both A‐PRF + and L‐PRF induced significant faster artificial wound closure than controls. Both PRF conditioned media induced faster cell migration in the initial phase (P < .01), but in the stoppage phase, the induced migration was higher for the A‐PRF+, compared with L‐PRF (P < .01).ConclusionL‐PRF and A‐PRF + have a stimulatory effect on migration and proliferation of periodontal fibroblasts, and artificial wound closure was longer sustained by A‐PRF + than L‐PRF.

Inhibition of NF-κB by Pyrrolidine Dithiocarbamate Prevents the Inflammatory Response in a Ligature-Induced Peri-Implantitis Model: A Canine Study

Background/Aims: The roles of toll-like receptor 4 (TLR4) and nuclear factor-kappa B (NF-κB) in peri-implantitis are unclear. Here, we used a canine model of peri-implantitis to explore the effects of inhibiting NF-κB with pyrrolidine dithiocarbamate (PDTC) on the inflammatory response in ligature-induced peri-implantitis. Methods: After successfully establishing the peri-implantitis model, beagles were randomly assigned to normal, model or PDTC groups. ELISA tests were used to determine the levels of interleukin (IL)-1, IL-6, IL-8 and tumor necrosis factor alpha (TNF-α). Immunohistochemistry was employed to assess the expression of NF-κB p65. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was performed to determine the mRNA levels of TLR4 and NF-κB p65, and western blot analysis was used to measure the protein levels of TLR4 in periodontal tissues from each group. Periodontal ligament fibroblasts (PDLFs) were cultured and subsequently classified into PDLF normal, PDLF model, PDLF LPS, PDLF PDTC, and PDLF LPS + PDTC groups. An immunofluorescence assay was used to measure the expression level of NF-κB p65. The CCK-8 assay and flow cytometry were performed to evaluate cell proliferation and apoptosis. Results: The in vitro results indicated that NF-κB p65 and TLR4 were upregulated in canine periodontal tissues, and PDTC could suppress the expression levels of NF-κB p65 and TLR4. Inflammation could increase TLR4 protein expression in canine periodontal tissue, and PDTC could inhibit the inflammation-induced increase in TLR4 protein expression. These results revealed that PDTC could reverse the LPS-induced increases in the levels of IL-1, IL-6, IL-8 and TNF-α. In vivo, the results demonstrated that PDTC inhibited the LPS-induced NF-κB p65 upregulation, and PDTC could reverse the inhibitory effect of the PDLF model + LPS on the proliferation of periodontal fibroblasts. The results also showed that in the PDLF model, LPS promoted PDLF apoptosis by inducing implant periodontitis in canines, but PDTC inhibited the PDLF apoptosis and relieved implant periodontitis in canines. Conclusion: Based on our results, we concluded that PDTC can inhibit the expression of NF-κB and alleviate the inflammatory response induced by LPS, thereby preventing periodontal inflammation and reducing the development of peri-implantitis.

Beta2-adrenergic receptor agonists reduce proliferation but not protein synthesis of periodontal fibroblasts stimulated with platelet-derived growth factor-BB

ObjectiveCatecholamines released from β-adrenergic neurons upon stress can interfere with periodontal regeneration. The cellular mechanisms, however, are unclear. Here, we assessed the effect of catecholamines on proliferation of periodontal fibroblasts. MethodsFibroblasts from the gingiva and the periodontal ligament were exposed to agonists of the β-adrenergic receptors; isoproterenol (ISO, non-selective β-adrenergic agonist), salbutamol (SAL, selective β2-adrenergic receptor agonist) and BRL 37344 (BRL selective β3-receptor agonist). Proliferation was stimulated with platelet-derived growth factor-BB (PDGF-BB). Pharmacological inhibitors and gene expression analysis further revealed β-adrenergic signalling. ResultsGingiva and periodontal ligament fibroblast express the β2-adrenergic receptor. ISO and SAL but not BRL decreased proliferation of fibroblasts in the presence of PDGF-BB. The inhibitory effect of β-adrenergic signalling on proliferation but not protein synthesis in response to PDGF-BB was reduced by propranolol, a non-selective β-adrenergic antagonist. ConclusionsThese results suggest that β2-receptor agonists can reduce the mitogenic response of periodontal fibroblasts. These data add to the compelling concept that blocking of β2-receptor signalling can support tissue maintenance and regeneration.