Résumé
@#Diabetes mellitus is a group of metabolic diseases characterized by hyperglycemia, often accompanied by bone metabolic disorders, microvascular diseases, etc. At present, it is still controversial whether diabetes will reduce the survival rate of implants, but studies have shown that diabetes can damage the bone tissue around the implants and interfere with the process of osseointegration by producing excessive reactive oxygen species(ROS). In this paper, combined with the literature published worldwide in recent years, the effect and mechanism of ROS on the osteointegration of implants of diabetic patients and the measures to improve the osteointegration under the condition of diabetes are reviewed. The results of literature review showed that excessive ROS induced by diabetes can damage osseointegration through adenosine 5′-monophosphate -activated protein kinase, Wnt/catenin, phosphatidylinositol 3-kinase-protein kinase B, mitogen activated protein kinase and other signaling pathways, as well as vascular injury. In animal models of diabetes, some drugs, such as insulin, curcumin, 1,25-dihydroxyvitamin D3, and metformin, have been shown to improve the osseointegration of implants to some extent by reducing ROS levels. These results suggest that ROS may be a key therapeutic target for improving success rate of dental implant treatment in diabetic patients.
Résumé
Objective In the present study, we investigated the effects of advanced oxidation protein products(AOPP) on reactive oxygen species(ROS) production in murine osteoblastic MC3T3-E1 cells by NADPH oxidase enzymes pathway. Methods Experiments were divided into three groups, including control group, rats albumin(RSA) group, and AOPP group. Different concentrations of AOPP were added to the osteoblastic MC3T3-E1 cells culture medium. The production of ROS in MC3T3-E1 cells was measured by the fluorescence intensity of intracellular fluoroprobe ( DCFD ) . In order to verify the effect of enzyme of the production of ROS, the specific inhibitors of corresponding enzymes were added in the MC3T3-E1 cells which were cultured in the medium with AOPP. Finally, western blot and immunofluorescence were used to observe the changes of NADPH oxidase enzymes subunits. Results Different concentrations of AOPP (50,100,200μg/ml) induced MC3T3-E1 cells to produce different amount of ROS. The higher concentrations of AOPP were added, the more ROS were produced. Furthermore,200μg/ml AOPP induced the maximum amount of ROS production(P<0. 05). Meanwhile, AOPP induced MC3T3-E1 cells to produce different amount of ROS with a time-dependent manner. The peak amount of ROS production in MC3T3-E1 cells was observed in 3h when AOPP were added (P<0. 05). In addition, when specific inhibitors of corresponding enzymes were added in the MC3T3-E1 cells, the production of ROS were significantly suppressed by C-SOD, DPI, and apocynin(P<0. 05). On the other hand, AOPP can up-regulate the expression of Nox4 protein of the MC3T3-E1 cells, which is one of the subunits of NADPH oxidase enzymes. Meanwhile, AOPP can also induce the membrane migration of p47phox subunit. Conclusion AOPP induces osteoblastic MC3T3-E1 cells to produce ROS by NADPH oxidase enzymes pathway, and which may be one of the pathogenesis of AOPP involved in osteoporosis.
Résumé
The changes of active oxygen species and some enzymes in Grifola umbellata induced by Armillaria mellea elicitor were studied.The results showed that active oxygen species appeared in both mycelia and sclerotia of G.umbellata after treated with A.mellea.There were two phases of active oxygen production upon addition of A.mellea elicitor.Phase I occured at 10 minute after addition of A.mellea elicitor.Phase Ⅱ occurred about 90 minute.The changes of some enzyme activity were also studied in this paper.Compared with control,the A.mellea elicitor could reduce the activity of superoxide dismutase and peroxidase.The catalase activity changed only little.The phenylanine ammonia lyase activity declined in the early stages and then increased in the late stages.