ABSTRACT
Objective @#To evaluate the effect of gingival stem cells-derived exosomes (GMSC-Exos) treatment on the expression of interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) in rats with periodontitis, so as to provide the evidence for periodontitis treatment.@*Methods@#Forty specific pathogen-free (SPF) rats at ages of 8 weeks were randomly divided into 4 groups, including the blank group, periodontitis group, GMSC-Exos group and PBS group. Rats in the periodontitis group, GMSC-Exos group and PBS group were modeled for periodontitis using the ligature method. Rats in the blank group and periodontitis group were given no treatment, while rats in the GMSC-Exos group and PBS group were given 20 μL GMSC-Exos and PBS by injection, respectively. The periodontal index was measured in all rats 4 weeks post-treatment, and the TNF-α and IL-6 levels were measured in rat serum samples using enzyme-linked immunosorbent assay (ELISA). The TNF-α and IL-6 gene expression was quantified using the polymerase chain reaction (PCR) assay in the gingival tissues of the rat left upper maxillary area, and the periodontal tissues in the left upper maxillary areas were sampled for pathological examinations. Periodontal clinical indexes, IL-6 and TNF-α levels were compared in each group.@*Results@#The gingival sulcus bleeding index, gingival index, probing depth, and plaque index in the GMSC-Exos group (1.87±0.41, 1.03±0.19, 1.91±0.09 and 1.11±0.17) were higher than those in the blank group (0.96±0.31, 0.83±0.31, 1.09±0.05 and 1.01±0.38), but lower than those in the periodontitis group (2.65±0.50, 1.36±0.22, 2.61±0.07 and 1.51±0.26) and PBS group (2.44±0.50, 1.23±0.20, 2.49±0.10 and 1.39±0.28) (all P<0.05). The serum IL-6 and TNF-α levels in the GMSC-Exos group [(205.97±11.47) and (90.11±8.57) pg/mL] were higher than those in the blank group [(143.10±4.87) and (80.07±5.13) pg/mL], but lower than those in the periodontitis group [(367.33±13.89) and (158.29±13.10) pg/mL] and PBS group [(364.23±13.62) and (140.60±11.73) pg/mL] (all P<0.05). The IL-6 and TNF-α mRNA expression in the rat gingival tissues in the GMSC-Exos group (1.09±0.14 and 1.61±0.29) was higher than that in the blank group (0.99±0.10 and 1.06±0.14), but lower than that in the periodontitis group (1.63±0.09 and 3.63±0.26) and PBS group (1.58±0.11 and 3.79±0.32) (all P<0.05). Pathological examinations showed alleviation of periodontal tissue destruction, inflammatory cell infiltration and alveolar bone resorption, and no obvious root dental root regeneration in the junctional combined epithelium in the GMSC-Exos group relative to the periodontitis group and the PBS group. @*Conclusion@#Administration of GMSC-Exos may reduce periodontal inflammation and alveolar bone resorption by inhibiting IL-6 and TNF-α expression in rats with periodontitis.
ABSTRACT
BACKGROUND: Periodontitis is a destructive inflammatory disorder of the periodontium caused by the destruction of periodontal tissues namely the PDL, cementum, alveolar bone, and gingiva. Once these tissues are lost, the foremost goal of periodontal therapy is to regenerate the diseased tissues if possible to their original form, architecture, and function. Various regenerative procedures were employed and still a gap was found in achieving the goal. As stem cells are characterized by their ability to self-renew and differentiate to produce specialized cells, there could be a possibility of using them for regenerative therapy. Recently, dental tissues such as the PDL, the dental pulp and the tooth follicle have been recognized as readily available sources of adult stem cells. AIM: The aim was to identify the various sources and methodologies in isolation of stem cells from human oral cavity and its differentiation into various lineages using markers. MATERIALS AND METHODS: The electronic databases PUBMED, GOOGLE SCHOLAR, SCIENCE DIRECT, COCHRANE LIBRARY along with a complimentary manual search of all periodontics journal till the year 2016. Thirteen articles were selected on the basis of the inclusion criteria. Isolation of stem cells from oral cavity through various methods has been evaluated and similarly characterization to different lineages were tabulated as variables of interest. They included human in-vitro and ex-vivo studies. RESULTS: The results showed that PDLSC's and pulpal stem cells are the most common source from where stem cells were isolated. Each source has used different methodology in isolating the stem cells and it was found that STRO-1 was the commonly used marker in all the studies mentioned. CONCLUSIONS: The studies showed that there is no standard protocol existed in isolating the stem cells from different sources of oral cavity. Moreover, there was no standard marker or methodology used in characterization.