Peri-implant diseases have a relatively high incidence,and immune-inflammatory re-sponses are closely associated with peri-implant mucositis and peri-implantitis.The complement sys-tem is a vital component of the immune system.Its activation not only regulates the initiation and pro-gression of inflammatory responses but also plays a crucial role in bone remodeling.This review sum-marizes the roles of the core complement components C3 and C5 in various stages of bone remodeling after implant placement,as well as in peri-implant mucositis and peri-implantitis.The aim of the pa-per was to provide novel insights for the prevention and treatment of peri-implantitis through targeted regulation of complement protein levels.

Objective To investigate the protective effects and mechanism of insulin(INS) on brain in septic rats,and explore the possible role of uncoupling protein 2 (UCP2) in these effects.Methods Fifty male specific pathogen free(SPF) Sprague-Dawley rats were randomly divided into normal control (CN) group(n=10),lipopolysaccharide(LPS) group(n=20) and INS group (n=20) according to random number table.The septic rat model was established through an intraperitoneal injection of 15 mg/kg LPS of gram-negative bacteria.The rats in the INS group received a 1 U/kg INS injection subcutaneously 30 minutes before the injection of LPS,and the rats in the CN group were given equivalent 9 g/L saline in the same way.Eight rats in each group were killed,and their cerebral cortex were collected after the injection of LPS for 24 h.Pathological change of cerebral cortex was detected by Hematoxylin-Eosin(HE) staining.The cerebral cortex mitochondia were extracted for detecting the levels of reactive oxygen species(ROS),malondialdehyde (MDA) and the activity of superoxide dismutase(SOD).Neuronal apoptosis was detected by terminal dexynucleotidyl transferase(TdT)-mediated dUTP nick end labeling staining.UCP2 mRNA expression was detected by quantitative real-time(RT)-PCR.Apoptosis-associated protein B lymphocyte tumor-2(Bcl-2),Bcl-2 associated X protein(Bax),cleaved cysteinyl aspartate specific protease(cleaved Caspase-9) and UCP2 protein expression were determined by Western blot.Results (1)Compared with the CN group,obvious abnormal pathological change was revealed by HE staining in cerebral cortex of rats in the LPS group and the INS group,but the pathological change was attenuated in the INS group compared with the LPS group.(2)Compared with the CN group,the levels of mitochondrial ROS[(210.01±14.09) RFU vs.(49.06±7.28) RFU] and MDA[(2.19±0.18) nmol/mg pro vs.(1.25±0.11)nmol/mg pro]in the LPS group significantly increased,whereas SOD activity significantly decreased [(238.49±35.60) U/g pro vs.(446.66±24.90)U/g pro],and the differences were significant(all P<0.05).Compared with the LPS group,the levels of ROS [(152.69±15.83) RFU vs.(210.01±14.09) RFU] and MDA[(1.55±0.14) nmol/mg pro vs.(2.19±0.18) nmol/mg pro] in the INS group decreased,while SOD activity increased[(327.8±23.26) U/g pro vs.(238.49± 35.60) U/g pro],and the differences were significant(all P<0.05).(3)Compared with the CN group,the neuronal apoptosis index of cortex in the LPS group was elevated[(54.16±6.84)% vs.(5.45±1.43)%],while the expression of Bcl-2 decreased (627±0.018 vs.0.739±0.020),but the expressions of Bax(0.768±0.019 vs.0.520±0.010) and cleaved Caspase-9(0.739±0.016 vs.0.467±0.030) increased,and the differences were significant(all P<0.05).Compared with the LPS group,the neuronal apoptosis index of cortex in the INS group decreased [(33.30±3.07)% vs.(54.16±6.84)%],but the Bcl-2 expression increased (0.743±0.022 vs.0.627±0.018),and Bax (0.687±0.034 vs.0.768±0.019) and cleaved Caspase-9(0.551±0.013 vs.0.739±0.016) were reduced,and the differences were significant (all P<0.05).(4)Compared with the CN group,the mRNA (2.248±0.155 vs.1.000±0.100) and protein expression of UCP2 (0.659±0.016 vs.0.599±0.018) were elevated in the LPS group.Compared with the LPS group,the UCP2 mRNA (2.944±0.117 vs.2.248±0.155) and UCP2 protein (0.719±0.018 vs.0.659±0.016) increased,and the differences were significant(all P<0.05).Conclusions INS can protect the brain of septic rats through alleviating mitochondrial oxidative stress and inhibiting the mitochondrial-initiated apoptotic pathway to reduce neuronal apoptosis.INS upregulates UCP2 expression in the brain of septic rats,which may play a role in the protective effects mentioned above.

AIM: To identify the down-regulated genes in adult rat cardiac fibroblasts (CF) stimulated with angiotensin Ⅱ (AngⅡ). METHODS: Suppression subtractive hybridization (SSH) was performed between the CF stimulated by AngⅡ (driver) and unstimulated CF (tester) to generate subtractive cDNA library. The library was screened with dot blots hybridization to further verify the differentially expressed cDNA clones. Partial positive clones were sequenced and BLAST analyzed. RESULTS: Seventeen down-regulated genes related to intracellular signal transduction, transcriptional repression, deposition of fibrous matrix and cellular cytoskeletal rearrangement, and 4 new expression sequence tags (EST) were acquired. CONCLUSION: SSH is a powerful technique with high sensitivity for the detection and clone of down-regulated genes expressed in CF induced by AngⅡ, which is helpful to clarify the mechanism of cardiac remodeling.