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BACKGROUND: MicroRNA-21 (miR-21) is a regulator of osteoclastogenesis and a promoter of osteoclast differentiation, but its role in periodontitis remains unclear. OBJECTIVE: To investigate whether miR-21 is involved in bone destruction in periodontitis. METHODS: Real-time PCR was used to detect and analyze the differential expression of miR-21 in periodontitis samples. Using liposome transfection method, miR-21 mimics (up-regulating miR-21) or miR-21 inhibitor (down-regulating miR-21) was used to transfect osteoclasts. Expressions of miR-21 and bone destruction markers TRAP and CTSK were detected by real-time PCR. Cell counting kit-8 was used to detect the miR-21 effect on osteoclast proliferation. RESULTS AND CONCLUSION: (1) MiR-21 expression increased in periodontitis samples. (2) When miR-21 mimics was transfected into osteoclasts, miR-21, TRAP and CTSK mRNA expression increased; when miR-21 inhibitor was transfected into osteoclasts, miR-21, TRAP and CTSK mRNA expression decreased. (3) Transfection with miR-21 mimics promoted the proliferation of osteoclasts, while transfection with miR-21 inhibitor inhibited the proliferation of osteoclasts. To conclude, miR-21 can be used as an important target for the treatment of periodontitis.
RESUMO
AIM: To study the inhibitory effect of captopril on retinal neovascularization (RNV).METHODS: Sixty seven-day-old mice were randomly divided into treated group and control group with thirty mice in each group. These mice were exposed to 750 50mL/L oxygen for 5 days and then to room air.The treated group had been injected captopril (2.7mL/kg), while control group had been injected 9g/L sodium chloride (2.7mL/kg) by intravitreal for 5 days.The mice were sacrificed at the 17th day after birth and the eyes were enucleated. Adenosine diphosphate-ase(ADPase) stained retina flat-mounts was performed to assess the retinal vascular profiles, Hematoxylin Eosin (HE)staining method was applied to count the number of new vascular cell nuclei and the expression of matrix metalloproteinase-2(MMP-2)and pigment epithelium derived factor (PEDF)was detected by immunohistochemical method.RESULTS: Comparing with control group,regular distributions and good branch and reduced density of RNV were observed in the treated group. The number of nucleus of new vessels vascular endothelial cells breaking through the internal limiting membrane was less in the treated group than in the control group (P<0.05). Stain of retinal MMP-2 was weaker in the treated group than in the control group and stain of retinal PEDF was stronger in the treated group than in the control group.CONCLUSION: Intravitreal injection of captopril (2.7mL/kg) may block the RNV in the oxygen-induced mouse model and may provide an effective method for prevent-ing RNV.