Regulation of colony-stimulating factor 1 receptor inhibitor pexidartinib on the senescence of mouse bone marrow-derived macrophages stimulated by lipopolysaccharide / 中华口腔医学杂志

Objective: To investigate the effects of colony-stimulating factor 1 receptor (CSF-1R) inhibitor pexidartinib (PLX3397) on the senescence of bone marrow-derived macrophages (BMDM) stimulated by lipopolysaccharide (LPS). Methods: BMDM were isolated and cultured from femurs and tibiae of 10 male C57BL/6 mice aged 6-8 weeks (obtained from Laboratory Animal Center of Guizhou Medical University). They were divided into blank control group, LPS group (treated with 1 μg/ml LPS for 24 h) as well as low, medium and high concentration PLX3397 pretreatment groups (treated with 100, 500 and 1 000 nmol/L PLX3397 for 4 h respectively followed by 1 μg/ml LPS for 24 h). The corresponding markers of macrophages were detected by flow cytometry. Cell viability was detected by cell counting kit-8 and cellular senescence was detected by senescence-associated-β-galactosidase (SA-β-gal) staining. Meanwhile, protein expressions of cycle-dependent kinase inhibitor p16, p21 and CSF-1R were detected by Western blotting, and the expressions of p16 and p21 were detected by intracellular immunofluorescence. Real-time fluorescence quantitative PCR (RT-qPCR) was used to investigate the mRNA levels of senescence-associated secretory phenotype (SASP) genes including interleukin (IL), IL-1β, chemokine-1/10 (CXCL-1/10), matrix metalloproteinase-8 (MMP-8), and transforming growth factor-β (TGF-β). Results: The rate of SA-β-gal positive staining in medium and high concentration PLX3397 pretreatment groups [(39.33±4.93)% and (36.33±3.06)% respectively] were significantly downregulated compared with LPS group [(52.00±3.00)%] (P=0.020, P=0.005). The expression of CSF-1R protein in low, medium and high concentration PLX3397 pretreatment groups were (0.74±0.18, 0.61±0.07, 0.54±0.06), all of which were significantly lower than that in LPS group (1.16±0.08) (P=0.013, P=0.002, P<0.001). The expression levels of CSF-1R mRNA in low, medium and high concentration PLX3397 pretreatment groups (1.04±0.06, 0.90±0.05, 1.18±0.08) showed similar trend (2.90±0.25) (P<0.001). The average fluorescence intensity of p16 in all PLX3397 pretreatment groups were 49.76±3.65, 48.21±1.72, 47.99±1.26 respectively, which were significantly lower than that in LPS group (66.88±5.85) (P=0.001, P<0.001, P<0.001). The average fluorescence intensity of p21 in medium and high concentration PLX3397 pretreatment groups were (34.43±3.62, 30.13±0.86), significantly lower than that in LPS group (46.82±5.33) (P=0.043, P=0.007). The expression of p16 protein in low, medium and high concentration PLX3397 pretreatment groups (0.56±0.04, 0.55±0.04, 0.35±0.19) were significantly lower than that in LPS group (0.98±0.10) (P=0.003, P=0.002, P<0.001), as well the expression of p21 protein (0.69±0.20, 0.42±0.08, 0.26±0.14) (P=0.032, P=0.002, P<0.001). According to the results of RT-qPCR, the expressions of IL-6, IL-1β, CXCL-1, CXCL-10 and MMP-8 in PLX3397 pretreatment groups were significantly lower than those in LPS group (P<0.001), while the expression of TGF-β increased (P<0.001). Conclusions: LPS could induce the cell senescence, increase the secretion of SASP and aggravate local inflammation by activating the CSF-1R on the cell surface of bone marrow-derived macrophages. CSF-1R inhibitor PLX3397 might attenuate CSF-1R activation associated with LPS and inhibit the senescence of bone marrow-derived macrophages induced by LPS.

Association between Volatile Sulfur Compounds Prevotella intermedia and Matrix Metalloproteinase-8 Expression

Abstract Objective: To determine the correlation between levels of methyl mercaptan (CH3SH) hydrogen sulfide (H2S), the proportion of Prevotella intermedia (Pi), and matrix metalloproteinase-8 (MMP-8) gene expression levels in periodontitis patients accompanied by halitosis. Material and Methods: Samples were obtained from gingival crevicular fluid (GCF) in the deepest pocket and by swabbing in the tongue coating area in patients with periodontitis presenting with halitosis (n = 23) and healthy subjects as controls (n = 7). The values of CH3SH and H2S were obtained using Oral Chroma. The proportion of Pi and MMP-8 expression levels were evaluated using PCR-RT. All the result was statistically analyzed using SPSS software. Results: The levels of CH3SH and H2S in participants with PD ≥ 6 mm showed a robust negative correlation with the proportion of P. intermedia in GCF and tongue coating. No statistically significant association was detected between CH3SH and H2S levels and MMP-8 expression levels (p>0.05). Conclusion: There is no association between CH3SH and H2S levels, the proportion of P. intermedia, and MMP-8 expression in patients with periodontitis accompanied by halitosis (AU).

Effects of vitamin C local application on ligature-induced periodontitis in diabetic rats

Abstract Objective: This study evaluated the effects of local vitamin C treatment on tissue advanced glycation end products (AGE), interleukin (IL)-6, 8-hydroxy-2-deoxyguanosine (8-OHdG), and matrix metalloproteinases (MMP)-8 in tissues; serum C-terminal telopeptide fragments (CTX); and alveolar bone loss (ABL) in rats. Methodology: 35 male Sprague Dawley rats were divided equally into five groups: 1) control (C), 2) experimental periodontitis (P), 3) experimental diabetes (D), 4) experimental diabetes and experimental periodontitis (D + P), and 5) experimental diabetes-experimental periodontitis-locally applied vitamin C (D + P + LvitC). Diabetes was induced in rats with alloxan monohydrate, after which periodontitis was induced by ligature placement in the right mandibular first molar teeth for 11 days. In the treatment group, vitamin C was administered locally three times with two-days interval after ligature removal. The animals were sacrificed, and the samples were analyzed histometrically and immunohistochemically. Results: CTX, 8-OHdG, and AGE values significantly decreased in the treatment group compared to the D + P group. IL-6 and MMP-8 values decreased in the treatment group compared to the D + P group, but this is not significant. ABL was significantly reduced by the local delivery of vitamin C. Conclusion: This study reveals that vitamin C treatment may be beneficial to reduce serum CTX and gingival MMP-8 levels, oxidative stress, inflammation, and AGE accumulation in periodontal tissue. Vitamin C may be an immunomodulator and antioxidant locally applied in the treatment of periodontitis to reduce the adverse effects of diabetes in periodontal tissues.

Effect of Garcinia mangostana L. and propolis extracts on the inhibition of inflammation and alveolar bone loss in ligature-induced periodontitis in rats

The purpose of this study was to evaluate the effect of mangosteen extract complex (MEC; Garcinia mangostana L. and propolis extracts) on the inhibition of inflammation and prevention of alveolar bone loss using a ligature-induced periodontitis model. Rat molars were ligatured with silk, and 1 µg/mL of lipopolysaccharide of Porphyromonas gingivalis was injected into the buccal and palatal gingivae of the teeth with or without treatment with the MEC. Changes in the expression levels of prostaglandin E₂ (PGE₂), interleukin-8 (IL-8), inducible nitric oxide synthase (iNOS), matrix metalloproteinase-8 (MMP-8), cyclooxygenase (COX)-1, and COX-2 in gingival tissues were evaluated using enzyme-linked immunosorbent assays. Alveolar bone loss around the ligated molars was examined using micro-computed tomography. The expression levels of PGE₂, IL-8, iNOS, MMP-8, COX-1, and COX-2 in gingival tissues were significantly reduced in the group treated with a mixture of 16 µg of mangosteen extract powder and 544 µg of propolis extract powder (ligation [Lig] + lipopolysaccharide extracted from P. gingivalis KCOM 2804 [L] + MEC 1:34). Additionally, alveolar bone loss was significantly reduced in the Lig + L + MEC 1:34 group compared with that in other groups. These results indicate that the MEC could be useful in preventing and treating periodontitis.

Clinical attachment loss and molecular profile of inflamed sites before treatment

Abstract Objective: To monitor early periodontal disease progression and to investigate clinical and molecular profile of inflamed sites by means of crevicular fluid and gingival biopsy analysis. Methodology: Eighty-one samples of twenty-seven periodontitis subjects and periodontally healthy individuals were collected for the study. Measurements of clinical parameters were recorded at day −15, baseline and 2 months after basic periodontal treatment aiming at monitoring early variations ofthe clinical attachment level. Saliva, crevicular fluid and gingival biopsies were harvested from clinically inflamed and non-inflamed sites from periodontal patients and from control sites of healthy patients for the assessment of IL-10, MMP-8, VEGF, RANKL, OPG and TGF-β1 protein and gene expression levels. Results: Baseline IL-10 protein levels from inflamed sites were higher in comparison to both non-inflamed and control sites (p<0.05). Higher expression of mRNA for IL-10, RANK-L, OPG, e TGF-β1 were also observed in inflamed sites at day −15 prior treatment (p<0.05). After the periodontal treatment and the resolution of inflammation, seventeen percent of evaluated sites still showed clinically detectable attachment loss without significant differences in the molecular profile. Conclusions: Clinical attachment loss is a negative event that may occur even after successful basic periodontal therapy, but it is small and limited to a small percentage of sites. Elevated inflammation markers of inflamed sites from disease patients reduced to the mean levels of those observed in healthy subjects after successful basic periodontal therapy. Significantly elevated both gene and protein levels of IL-10 in inflamed sites prior treatment confirms its modulatory role in the disease status.

Expression of Toll-Like Receptor 4 and Matrix Metalloproteinase 8 in Gingival Crevicular Fluid in Patients with Periodontitis

Abstract Objective: To determine the expression of TLR4 and MMP8 in gingival crevicular fluid [GCF] in patients with periodontitis. Material and Methods: Clinical samples were collected from 23 gingival crevicular fluid of periodontal disease subjects (n = 14) and healthy periodontal subjects (n=9). Measurement of Clinical parameters of probing pocket depth (PPD), bleeding on probing (BOP), and clinical attachment loss (CAL) were included as diagnostic criteria. Pocket Depth (PD) and CAL were defined as present if the PPD was ≥ 4 mm and the CAL ≥ 1 mm. Expression of TLR4 and MMP8 in the gingival crevicular fluid of deep pockets (PD≥ 6mm), shallow pockets (PD 4-5 mm) and healthy periodontal sulcus (0-3 mm) were evaluated by quantitative real-time polymerase chain reaction (qRT-PCR). Statistical analysis to compare the pocket was using Independent t-test and Mann-Whitney test. Correlation between mRNA expression and clinical parameters was analyzed using Spearman's correlation test Results: Expression of TLR4 was higher in shallow pockets compared to the control group, but the difference was not statistically significant (p>0.05). The expression of MMP8 was higher in shallow pockets compared to the control group, but the difference was not statistically significant (p>0.05) either. There is no significant correlation between TLR4 and MMP8 with clinical periodontal parameters Conclusion: TLR4 and MMP8 mRNA expression levels should not be used as a clinical biomarker in periodontitis diagnostic tools.

Local application of statins in the treatment of experimental periodontal disease in rats

Abstract Objective The objective of this study was to evaluate the local effects of statins as adjuvants for treatment by scaling and root planing (SRP) of periodontal disease induced in rats. Material and Methods Ninety rats were used in the present experiment. Periodontal disease was induced in all animals using a cotton thread placed in the left first mandibular molar. After 7 days of induction, the bandage was removed and the animals were divided into three groups: 1) NT group (n=30), no treatment; 2) SRP group (n=30): SRP and irrigation with control gel; 3) S group (n=30) - SRP and irrigation with Simvastatin. Ten animals from each group were euthanized at 7, 15 and 30 days after treatment. Gingival biopsy specimens were processed to analyze the expression of matrix metalloproteinase 8 (MMP-8). The mandibles were removed and submitted to radiographic and laboratory processing for histometric analysis. Results The S group showed a significantly lower expression of MMP-8 compared to NT and SRP groups in all experimental periods. In the radiographic and histometric analyses between the groups, S group showed a significantly lower bone loss (BL) compared to NT and SRP groups in all experimental periods. Conclusions Within the limits of this study, it can be concluded that locally applied statin was effective as an adjuvant treatment for SRP in rats with induced periodontal disease.

Analysis of salivary protease spectrum in chronic periodontitis / 华西口腔医学杂志

<p><b>OBJECTIVE</b>This study aimed to investigate the difference in salivary protease expression in patients with chronic periodontitis and normal individuals.</p><p><b>METHODS</b>The stimulating saliva in patients with chronic periodontitis and normal individuals were collected. Protein chip technology was adapted to analyze salivary protease spectrum.</p><p><b>RESULTS</b>Among the 34 proteases in the chip, disintegrin and metalloproteinase (ADAM)8, matrix metalloproteinase (MMP)-8, MMP-12, neprilysin/CD10, and uridylyl phosphate adenosine/urokinase showed a significantly increased concentration in the saliva of chronic periodontitis patients compared with those in the saliva of normal individuals (P<0.01). By contrast, the concentrations of ADAM9, a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS)1, ADAMTS13, cathepsin B, E, L, V, X/Z/P, kallikrein 6, 7, 11, 13, MMP-9, proteinase 3, presenilin-1, and proprotein convertase 9 sharply decreased (P<0.05).</p><p><b>CONCLUSIONS</b>The results demonstrated that protease spectrum in the saliva of chronic periodontitis patients and normal individuals significantly differed. Analysis of salivary protease spectrum is a potential clinical method to examine, diagnose, and monitor chronic periodontitis.</p>

Cytokine and metalloproteinases in gingival fluid from patients with chronic periodontitis / Niveles de citocinas y metaloproteinasas en fluido gingival de pacientes con periodontitis crónica

The purpose of the present research was to determine the levels of IL-1α, IL-1β, TNF-α, IL-6, IL-6sR, IL-8, IL-10, MMP-3 and MMP-8 in gingival crevicular fluid (GCF) of subjects with chronic periodontitis. Clinical measurements were carried out in 20 patients with chronic periodontitis and 11 periodontally healthy controls. The clinical indexes evaluated were: gingival index (GI), plaque index (PI), bleeding on probing (BOP), probing depth (PD) and clinical attachment loss (CAL); the measurements were taken at six sites per tooth in all teeth in each subject. GCF samples were taken from one tooth per quadrant, and the levels of mediators were measured using an ELISA test. Statistically significant differences were observed between patients and control group in relation to all clinical parameters evaluated (p<0.05). The gingival concentrations, in pg/mL, of IL-1α (patients: 239.06 ± 65.5 vs control: 97.79 ± 15.81), IL-1β (patients: 157.19 ± 36.4 vs control: 63.44 ± 19.04), TNF-α (patients: 10.87 ± 1.7 vs control: 1.15 ± 0.84), IL-6 (patients: 3.77 ±1.7 vs control: 0.43 ± 0.22), IL-6Sr (patients: 655.59 ± 185.8 vs control: 73.59 ± 23.18), IL-8 (patients: 496.3 ± 155.3 vs control: 206.13 ± 46.63), IL-10 (patients: 10.75 ± 3.6 vs control: 2.41 ± 0.57), MMP-3 (patients: 3531 ± 1558.2 vs control: 724.84 ± 289.51) and MMP-8 (patients: 8231.70± 1279.2 vs control: 1534.67± 814.90) were significantly greater in patients with periodontal disease than in the control group (p<0.001). The higher levels of the cytokines and metalloproteinases obtained in this study were significantly associated with the severity of the periodontal disease.

El propósito de la presente investigación fue determinar los niveles de IL-1α, IL-1β, TNF-α, IL-6, IL-6sR, IL-8, IL-10, MMP-3 and MMP-8 en fluido gingival crevicular (FGC) de sujetos con periodontitis crónica. Se evaluaron los parámetros clínicos en 20 pacientes con periodontitis crónica y 11 controles periodontalmente sanos. Los índices clínicos evaluados fueron: indice gingival (IG), indice de placa dental (IP), sangramiento al sondaje (SS), profundidad del saco (PS) y nivel de inserción (NI). Las muestras de FGC fueron tomadas de un diente por cada cuadrante y los niveles de los mediadores fueron medidos utilizando la prueba de ELISA. Se observaron diferencias estadísticamente significativas entre los pacientes y el grupo control en relación a todos los parámetros clínicos evaluados (p<0,05). Las concentraciones en fluido gingival en pg/mL de IL-1α(pacientes: 239,06 ± 65,5 vs control: 97,79 ± 15,81), IL-1β (pacientes: 157,19 ± 36,4 vs control: 63,44 ± 19,04), TNF-α (pacientes: 10,87 ± 1,7 vs control: 1,15 ± 0,84), IL-6 (pacientes: 3,77 ±1,7 vs control: 0,43 ± 0,22), IL-6Sr (pacientes: 655,59 ± 185,8 vs control: 73,59 ± 23,18), IL-8 (pacientes: 496,3 ± 155,3 vs control: 206,13 ± 46,63), IL-10 (pacientes: 10,75 ± 3.6 vs control: 2,41 ± 0,57), MMP-3 (pacientes: 3531 ± 1558,2 vs control: 724,84 ± 289,51) and MMP-8 (pacientes: 8231,70± 1279,2 vs control: 1534,67± 814,90), estuvieron significativamente mayores en pacientes con enfermedad periodontal que en el grupo control. (p<0,001). Los niveles elevados de citocinas y metaloproteinasas obtenidos en este estudio estuvieron significativamente asociados con la severidad de la enfermedad periodontal.

Effects of serum starvation on cell cycle synchronization in primary human umbilical vein endothelial cells / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the optimal starvation conditions of human umbilical vein endothelial cells (HUVECs) and establish a highly efficient and stable method for separating HUVECs.</p><p><b>METHODS</b>HUVECs harvested from human umbilical cords by digestion with 0.1% collagenase II for 15 min were cultured in endothelial culture medium (ECM) containing 5% fetal bovine serum (FBS), 1% endothelial cell growth factor (ECGS) and 1% penicillin/streptomycin solution(P/S) at 37 degrees celsius; in 5% CO2. The cells were observed for cell morphology under an inverted microscope and identified with immunofluorescence assay. The purity of HUVECs was detected using flow cytometry (FCM). The cell cycles of HUVECs cultured in the presence of 0, 0.1%, 0.5%, and 1% FBS for 0, 6, 12, 18, and 24 h were analyzed with flow cytometry.</p><p><b>RESULTS</b>s The purity of HUVECs harvested by digestion with 0.1% collagenase II reached 99.67%. The primary HUVECs showed a cobblestone or volute appearance in vitro. Immunocytochemistry showed that HUVECs highly expressed VIII-related antigen. Cell culture in the presence of different concentrations of FBS for 6 h resulted in 70% G0/G1 phase cells, which increased to 80%-90% at 12 h of cell culture, and further to around 95% at 18 and 24 h.</p><p><b>CONCLUSION</b>Digestion with 0.1% collagenase II can obtain high-purity primary HUVECs. Culturing HUVECs in serum-free medium for 12 h can result in a high purity (over 80%) of G0/G1 phase cells.</p>

Effects of hydrogen sulfide on myocardial fibrosis and MAPK1/3 and MMP-8 expression in diabetic rats / 南方医科大学学报

<p><b>OBJECTIVE</b>To explore the effects of hydrogen sulfide (H(2)S) on myocardial fibrosis and expressions of MAPK1/3 and MMP-8 in diabetic rats.</p><p><b>METHODS</b>Forty adult male SD rats were randomized into 4 groups, namely the control group, diabetes mellitus group (STZ group), diabetes mellitus with H(2)S treatment group (STZ+H(2)S group), and normal rats with H(2)S treatment group (H(2)S group). Diabetes was induced by intraperitoneal injections of 40 mg/kg streptozotocin (STZ). The rats in the control group received daily intraperitoneal injections of saline, and those in STZ+H(2)S group and H(2)S group were given NaHS (100 µmol/kg) injections. After 8 weeks, the pathologies of cardiac fibrosis were examined with HE staining, and the expressions of collagen I, MAPK1/3 and MMP-8 were analyzed with Western blotting.</p><p><b>RESULTS</b>Compared with the control group, the diabetic rats showed increased collagen content and obvious interstitial fibrosis in the myocardial tissue with significantly increased expression levels of collagen I, MAPK1/3 and MMP-8 (P<0.05); all these changes were obviously reversed by treatment with H(2)S (P<0.05). Collagen I, MAPK1/3 and MMP-8 expression levels and the degree of myocardial fibrosis were comparable between H(2)S group and control group (P>0.05).</p><p><b>CONCLUSION</b>Hydrogen sulfide can attenuate cardiac fibrosis in diabetic rats, and the mechanism may involve the inhibition of MAPK1/3/MMP-8 signal pathway.</p>

Umbilical Cord Blood Matrix Metalloproteinase-9 Levels are associated with Funisitis / 대한주산의학회잡지

PURPOSE: Intrauterine inflammation (IUI) is a leading cause of preterm delivery. Although matrix metalloproteinase-8 (MMP-8) and intercellular adhesion molecule-1 (ICAM-1) are known to be related with IUI, it has not been fully elucidated whether MMP-9 or ICAM-3 is associated with IUI. We performed this study to determine whether the levels of tumor necrosis factor-alpha (TNF-alpha), MMP-9 and ICAM-3 in umbilical cord blood of preterm infants are associated with chorioamnionitis, funisitis or bronchopulmonary dysplasia. METHODS: Eighty-two pairs of pregnant women and their preterm newborns <35 weeks gestation were enrolled. Levels of TNF-alpha, MMP-9 and ICAM-3 in umbilical cord blood were measured using immunoassays and compared with results of histological examination of placenta and clinical data of the study participants. RESULTS: The level of MMP-9 in umbilical cord blood was significantly associated with the presence of funisitis (P =0.007). The level of TNF-alpha in umbilical cord blood was significantly associated with the development of bronchopulmonary dysplasia (P =0.030). However, presence of chorioamnionitis or funisitis was not associated with development of bronchopulmonary dysplasia. With the establishment of receiver operating characteristic (ROC) curve, the best cut-off value for umbilical blood MMP-9 was 99.42 pg/mL in identification of funisitis. The area under a constructed ROC curve for prediction of funisitis was 0.847 (standard error, 0.112; 95% confidence interval, 0.750-0.917). CONCLUSION: Measurement of MMP-9 concentration in umbilical cord blood may be an alternative way to predict whether a preterm infant has been exposed to IUI. Further study with larger numbers of subjects will be necessary to elucidate the association between the presence of IUI and neonatal adverse outcome.

Matrix metalloproteinase-8 inhibitors mitigate sepsis-induced myocardial injury in rats / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Sepsis-induced myocardial injury (SIMI) is caused by a variety of mechanisms. The aim of the study is to investigate the effects of metalloproteinase-8 (MMP-8) on SIMI and its mechanisms in rats.</p><p><b>METHODS</b>Forty male Sprague Dawley rats were randomly divided into four groups: MMP-8 inhibitor (M8I), dexamethasone (DEX), sepsis, and sham groups. The sepsis model was established by cecal ligation and puncture (CLP). Rats in the M8I group immediately received an intraperitoneal injection of M8I (0.1 mg/kg) after CLP. Rats in the DEX group immediately received an intraperitoneal (IP) injection of DEX (2 mg/kg). Rats in the sepsis and sham groups received intraperitoneal injections of normal saline. Rats were sacrificed 12 hours after CLP. Paraffin sections were stained with hematoxylin and eosin to observe the myocardium. The myocardial ultrastructure was observed with transmission electron microscopy. MMP-8, tumor necrosis factor-α (TNF-α), and interleukin-1β (IL-1β) were detected by immunohistochemistry. The expression of MMP-8 was measured by Western blotting. TNF-α and IL-1β levels in serum and myocardial tissue were determined by enzyme-linked immunosorbent assay.</p><p><b>RESULTS</b>Compared with the sham group, the myocardium in the sepsis group was seriously injured. MMP-8, TNF-α and IL-1β expression was higher in the sepsis group than in the sham group. Treatment with M8I or DEX, however, attenuated sepsis induced histopathological changes in the heart, and was associated with significant reductions in serum and myocardial levels of TNF-α and IL-1β (P < 0.05). M8I significantly inhibited MMP-8 expression in myocardial tissue (P < 0.05). In addition, treatment with DEX was not associated with a change in myocardial levels of MMP-8 (P > 0.05).</p><p><b>CONCLUSION</b>MMP-8 inhibitor attenuated myocardial injury in septic rats, which might be related to reduced expression of TNF-α and IL-1β.</p>

Anti-proteolytic capacity and bonding durability of proanthocyanidin-biomodified demineralized dentin matrix / 国际口腔科学杂志·英文版

Our previous studies showed that biomodification of demineralized dentin collagen with proanthocyanidin (PA) for a clinically practical duration improves the mechanical properties of the dentin matrix and the immediate resin-dentin bond strength. The present study sought to evaluate the ability of PA biomodification to reduce collagenase-induced biodegradation of demineralized dentin matrix and dentin/adhesive interfaces in a clinically relevant manner. The effects of collagenolytic and gelatinolytic activity on PA-biomodified demineralized dentin matrix were analysed by hydroxyproline assay and gelatin zymography. Then, resin-/dentin-bonded specimens were prepared and challenged with bacterial collagenases. Dentin treated with 2% chlorhexidine and untreated dentin were used as a positive and negative control, respectively. Collagen biodegradation, the microtensile bond strengths of bonded specimens and the micromorphologies of the fractured interfaces were assessed. The results revealed that both collagenolytic and gelatinolytic activity on demineralized dentin were notably inhibited in the PA-biomodified groups, irrespective of PA concentration and biomodification duration. When challenged with exogenous collagenases, PA-biomodified bonded specimens exhibited significantly less biodegradation and maintained higher bond strengths than the untreated control. These results suggest that PA biomodification was effective at inhibiting proteolytic activity on demineralized dentin matrix and at stabilizing the adhesive/dentin interface against enzymatic degradation, is a new concept that has the potential to improve bonding durability.

Inhibitory effect of a novel crosslinking quaternary ammonium methacrylates on matrix metalloproteinases / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To evaluate the anti-matrix metalloproteinase (MMP) activity of a novel crosslinking quaternary ammonium methacrylates, 2-methacryloxylethyl dodecylmethyl ammonium bromide (MAE-DB).</p><p><b>METHODS</b>The effects of MAE-DB at different concentrations (1%, 3%, 5%, 7%) on soluble matrix metalloproteinase-8 (MMP-8) were investigated using fluorescent assay kit. Readings were taken every 20 min for 3 h. The 1, 10-phenanthroline provided by the assay kit served as control group. Demineralized dentin beams were randomly divided into three groups (n = 50) and immersed in different solutions: artificial saliva, MAE-DB incorporated artificial saliva and chlorhexidine incorporated artificial saliva. After temperature cycling, the changes of ultimate tensile strength were measured to determine the effect of MAE-DB on the activity of matrix-bound endogenous matrix metalloproteinases. The morphology of dentin collagen fibrils in the three groups was observed via transmission electron microscopy (TEM).</p><p><b>RESULTS</b>MAE-DB could effectively inhibit the activity of soluble MMP-8. The inhibition percentage of 3% MAE-DB was 99.53% after 1 h, and it was significantly higher than that of 1, 10-phenanthroline (95.71%, P < 0.05). After temperature cycling, the ultimate tensile strengths of MAE-DB groups were significantly higher than those of the artificial saliva groups and the chlorhexidine groups (P < 0.05). TEM micrographs of MAE-DB group revealed that the microstructure of the collagen fibrillar was intact, while the fibrillar in the artificial saliva group was disrupted, indicating a protective function of MAE-DB on dentin collagen.</p><p><b>CONCLUSIONS</b>MAE-DB can inhibit the activity of MMP and protect dentin collagen from enzyme degradation.</p>

Effect of quaternary ammonium methacrylates incorporation into a dental adhesive on the resistance of enzymatic degradation of resin-dentine interfaces / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To evaluate the effect of quaternary ammonium methacrylates incorporation into a dental adhesive on the resistance of enzymatic degradation of resin-dentine interfaces.</p><p><b>METHODS</b>Thirty caries-free extracted human third molars were randomly divided into three groups (n = 10): 2-methacryloxylethyl dodecylmethyl ammonium bromide (MAE-DB) incorporated adhesive served as the experimental group, pre-treatment with chlorhexidine (CHX) served as a positive control, Adper(TM) Single Bond 2 served as a negative control. The resin-dentin interfaces were prepared using total etch bond system. After storage in distilled water at 37 °C for 24 h, the bonded teeth were vertically sectioned into beams. Beams were respectively immersed in artificial saliva containing 2 g/L MMP-8 at 37 °C for 0 h, 24 h and 120 h (n = 30). Micro-tensile bond strength, failure modes and nanoleakage were examined.</p><p><b>RESULTS</b>There were no significantly differences of micro-tensile bond strength between groups before hydrolysis (P > 0.05). After the enzymatic hydrolysis of 24 h and 120 h, the micro-tensile bond strength of MAE-DB groups [(31.13 ± 8.77) MPa, (24.14 ± 6.64) MPa] were significantly higher than that of the negative control groups [(25.63 ± 6.90) MPa, (15.22 ± 6.57) MPa] (P < 0.05). Most of the failures were found in the base part of the hybrid layer in the negative control group, while failures occurred through the top of the hybrid layer in CHX and MAE-DB groups after the enzymatic hydrolysis.Specimens from each immediate group showed minor silver deposits in hybrid layer. After beams being enzymatic hydrolyzed for 120 h, it was shown that the silver nitrate uptake in the negative control group were significantly different from those in the CHX and MAE-DB groups (P < 0.05).</p><p><b>CONCLUSIONS</b>Dental adhesive incorporation of MAE-DB could improve the anti-degrade ability of resin-dentin interfaces.</p>

The frequency and clinical significance of intra-amniotic inflammation defined as an elevated amniotic fluid matrix metalloproteinase-8 in patients with preterm labor and low amniotic fluid white blood cell counts

OBJECTIVE: To determine the frequency and clinical significance of intra-amniotic inflammation (IAI) defined as an elevated amniotic fluid (AF) matrix metalloproteinase-8 (MMP-8) concentration in patients with preterm labor and intact membranes (PTL) and low AF white blood cell (WBC) counts. METHODS: Adverse pregnancy outcomes were compared according to the presence or absence of IAI in 220 singleton gestations who underwent amniocentesis due to PTL (gestational age or =23 ng/mL). RESULTS: IAI was present in 19% of study population. Adverse pregnancy outcomes were significantly more frequent in patients with IAI than in those without IAI (preterm birth within 5 days of amniocentesis, 88% vs. 41%; acute-HCA, 47% vs. 11%; positive AF culture, 10% vs. 2%; each for P<0.05). Patients with IAI had a significantly shorter median amniocentesis-to-delivery interval than those without IAI (7.8 hours [0.01-3,307.3 hours] vs. 310.3 hours [0.01-2,973.8 hours]; P<0.001 from survival analysis). Multiple logistic regression analysis demonstrated that only an IAI (odds ratio, 3.3; 95% confidence interval, 1.5-7.3; P<0.005) retained a statistical significance in the prediction of acute-HCA after other confounding variables were adjusted. CONCLUSION: Approximately one-fifth of patients with PTL and low AF WBC counts have an evidence of IAI and are at risk for impending preterm delivery and acute-HCA when AF MMP-8 concentration is used.

Which is more important for the intensity of intra-amniotic inflammation between total grade or involved anatomical region in preterm gestations with acute histologic chorioamnionitis?

OBJECTIVE: There is no data on which is more important for the intensity of intra-amniotic inflammation (IAI) between total grade or involved anatomical region in acute histologic chorioamnionitis (acute-HCA) of preterm-gestations. The objective of current study is to examine this issue. METHODS: The intensity of IAI was measured by amniotic fluid (AF) white blood cell (WBC) count and matrix metalloproteinase-8 (MMP-8) concentration in 225 singleton preterm-gestations (0.05) and between the four groups (group-3, cases with total grade 2 vs. group-4, cases with total grade 3 vs. group-5, cases with total grade 4 vs. group-6, cases with total grade 5-6) among cases with extension beyond chorio-decidua (each for P>0.05). However, group-3 (cases with extension beyond chorio-decidua) had a significantly higher median AF WBC and MMP-8 than group-2 (cases with chorio-decidua restriction) among cases with total grade 2 (each for P<0.05). CONCLUSION: Involved anatomical region is more important than total grade for the intensity of IAI in acute-HCA of preterm-gestations.

Association between matrix metalloproteinase-8 -799C/T polymorphism and instability of carotid plaque / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To investigate the association between a -799C/T polymorphism in the promotor region of matrix metalloproteinase-8 (MMP-8) gene and instability of carotid plaque in Chinese Han population.</p><p><b>METHODS</b>A total of 451 acute infarction patients from the Department of Neurology of Taizhou Hospital were divided into carotid vulnerable plaque group and carotid stable plaque group according to the results of carotid B-mode ultrasonography. Serum MMP -8 level was measured by the means of enzyme-linked immunosorbent assay (ELISA). At the same time, the MMP-8 -799C/T polymorphism was determined by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method.</p><p><b>RESULTS</b>Serum level of MMP-8 in the carotid vulnerable plaque group was higher than that in the carotid stable plaque group (t= 2.894, P= 0.004). The genotype distribution of -799C/T polymorphism between the two groups was significantly different (Chi-square = 13.65, P= 0.000). Serum level of MMP-8 in patients with TT genotype was higher than that in patients with CC genotype (t= 3.141, P= 0.001).</p><p><b>CONCLUSION</b>The present study suggested that serum level of MMP-8 and the -799C/T polymorphism of MMP-8 gene are associated with carotid vulnerable plaque in Chinese Han population, and the T allele may be a predictor for the susceptibility of carotid vulnerable plaque.</p>

dynamics of gene expression of matrix metalloproteinase-8 and tissue inhibitor metalloproteinase-1 on removable orthodontic appliance wearers

The teeth will move if subjected to pressure through orthodontic appliances which causes a remodeling of periodontal ligament and alveolar bone. MMP-8 plays an important role in the remodeling process during orthodontic movement. The expression of MMP-8 gene is regulated by a natural inhibitor namely TMP-1. The purpose of this study was to observe the MMP-8 and TIMP-1 gene expressions in the gingival crevicular fluid [GCF] of patients with removable orthodontic appliance. A sample of 8 patients wearing orthodontic appliances was obtained. The finger springs were activated with 75 grams of force to produce canine distalization. GCF samples were collected from the distal side of upper canines before force application, 1-, 2-, 3-, and 4 weeks after application consecutively. The samples were analyzed by using RT-PCR. Statistical univariate analysis was used to show the distribution and percentages of the gene expressions. The gene expression of MMP-8 at t[0] was 28.1% but the force application elevated its expression to 62.5% at t[1], and then decreased continuously at t[2] [37.5%], t[3] [34.4%], and t[4] [31.3%]. The gene expression of TIMP-1 at t[0] was 40, 6% but the force application elevated its expression to 59,4% at t[1], and then decreased continuously at t[2] [43,8%], t[3] [40.6%], and t[4] [37.5%]. In conclusion, there was a dynamic gene expressions of MMP-8 and TIMP-1 before and after force application and the pattern was similar, i.e. the highest level happened on the first week, but it declined continuously in the following weeks