Effect of gingival stem cells-derived exosomes on interlukin (IL)-6 and tumor necrosis factor (TNF)-α expression in rats with periodontitis / 预防医学

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.