| Objectives: To establish an animal model of type 2 diabetes mellitus(T2DM)in Bama minipigs and to observe the histopathological changes of gingival tissue,tumor necrosis factor alpha(TNF-?)and interleukin-1?(IL-1?)in serum and gingival tissue,in order to further study mechanism of periodontal diseases in diabetes and the establishment of basic diabetes related dental implants treatment methods.Methods: Fourteen male Bama minipigs were divided into control group and experimental group,7 on each group.The control group was fed with basal diet,and the experimental group was fed with high-sugar and high-fat diet.By the end of 5 months,a single injection of Streptozotocin(STZ)(70 mg/kg)was given to the ear vein,and the high-sugar and high-fat diet was continued.The blood samples of minipigs were taken every month to detect the changes in fasting blood glucose(FPG),fasting insulin(FINS);the intravenous glucose tolerance test(IVGTT)and were determined whether it was type 2 diabetes mellitus.A periodontal examination,probing depth(PD)and attachment loss(AL),simplified oral hygiene index(OHI-S),bleeding index(BI),and tooth loosening were examined before sacrifice on both the groups.The X-ray and CBCT scans were performed to observe the periodontal imaging changes in both groups.By the end of 10 months,the animals were sacrificed and their gingival tissues,liver,kidney,pancreas,and heart were collected.Hematoxylin-eosin(H&E)was used to observe the histopathological changes and the levels of TNF-? and IL-1? in serum was detected by enzyme-linked immunosorbent assay(ELISA).The expressions of TNF-? and IL-1? in gingival tissue were detected by immunohistochemical method(IHC)and detected by fluorescence quantitative RT-PCR.SPSS17.0 statistical software was used to analyze the experimental results.The experimental results were expressed as mean ± standard deviation(±s),?=0.05.The difference was statistically significant at P<0.05.Results: 1.on the first day of modeling,the fasting plasma glucose in experimental group and control group was(4.46±0.52&4.43±0.34)mmol/L;fasting insulin was(175.50±30.02&177.20±33.04)pmol/L,respectively.There was no statistically significance.By the end of the experiment,fasting plasma glucose was(16.02±1.72&4.63±0.79)mmol/L in the experimental group and on the control group fasting insulin was(196.60±51.43&188.2±18.08)pmol/L.There was a significant difference between the two groups.The comparison between the control group and the experimental group showed symptoms of type 2 diabetes with hyperglycemia,insulin resistance,and impaired glucose tolerance which can be considered as a successful establishment of minipig as type 2 diabetes mellitus models.2.The levels of TNF-? and IL-1? in serum were detected by ELISA.The results showed that the levels of TNF-? and IL-1? in the serum of the control group and the experimental group had no significant difference(P>0.05).By the 4th month and 10 th month,the serum levels of TNF-? and IL-1? in the experimental group were all increased compared with the control group,and the difference was significant(P<0.05).In the comparison between the three different time periods,the levels of TNF-? and IL-1? in the serum of the control group were not significantly different(P>0.05);but in the serum of the experimental group,TNF-? was increased with time.The contents of IL-1? was also increased,and the difference was significant(P<0.05).3.Periodontal examination revealed that there was no difference in probing depth(PD)and loss of attachment(AL)between the experimental group and the control group,statistically significance(P>0.05).Simplified oral hygiene index(OHI-S)and bleeding index(BI)showed statistically significance,P<0.05).The physiological loosening of teeth showed no significance in both groups.4.By the end of the experiment,X-ray and CBCT scans showed that no significant alveolar bone resorption was observed in both the control and the experimental group minipigs.5.Histopathological observations of the gingiva,liver,kidney,heart and pancreas showed that the control group had normal histological structure and no obvious pathological changes were seen under the microscope.While in the experimental group,the epithelial nail mutations in the gingival tissue of the experimental group were round and thick,and the connective tissue was loose and reticulate.Fibrous destruction,local vascular hyperplasia,and a large number of inflammatory cell infiltration;hepatic tissue lobular structure is relatively loose,hepatic cells are disordered,hepatocytes are slightly swollen,nuclei are concentrated,vacuoles are present in the cells,and central lobule inflammation occurs.Vascular dilatation and congestion,lymphocytic infiltration,a large number of inflammatory cells has infiltrated renal tissue,tubular basement membrane thickening,some renal tubular atrophy,glomerular formation of small vacuoles,diffuse water degeneration,myocardial tissue disorder,Arranged in strips,the striated muscle interstitial space increases,there is inflammation,nuclear condensation,myocardial vascular congestion;pancreatic tissue islet is atrophic,the edge is irregular,the number of islet cells is reduced,chromatin is not uniform,and the cell arrangement is disordered A large number of vacuoles were observed.6.The detection of gingival tissue by Immunohistochemical staining showed that: compared with the control group,the expression of both TNF-? and IL-1? in the gingival connective tissue of the experimental group increased,and the difference was significant(P<0.01).7.Quantitative RT-PCR detection of gingival tissue compared with the control group and experimental group showed that the expression of TNF-? mRNA was significant(P<0.01);the expression of IL-1? mRNA was also significant(P < 0.05).Conclusions: 1.Models of type 2 diabetes in Bama minipigs were successfully established by intravenous injection of streptozotocin(STZ)at a dose of 70 mg/kg with supplementation of high-sugar and high-fat diets.2.The gingival tissues of diabetic minipigs had higher inflammation than normal minipigs.Our data suggest that diabetes may lead to increased expression of TNF-? and IL-1? in serum and gingival tissues.TNF-? and IL-1? may be involved in the pathogenesis of type 2 diabetes periodontal disease.This is consistent with the hypothesis that hyperglycemia causes an increased inflammatory response in the periodontium. |
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