BACKGROUND:Whether activating transcription factor 7 interacting protein(Atf7ip)is involved in the regulation in osteogenic differentiation is still controversial,and studying its impact on osteogenic differentiation and its specific mechanisms is of great significance. OBJECTIVE:To investigate the effect of Atf7ip on bone morphogenetic protein 2 promoting osteogenic differentiation of mouse embryonic osteoblast precursor cells(MC3T3-E1). METHODS:MC3T3-E1 cells cultured in vitro were divided into three groups:normal group,interference group(NC-siRNA group,Atf7ip-siRNA group),and high expression group(CMV-VC group and CMV-Atf7ip group),and were transfected for 24 hours,and then treated with 200 ng/mL bone morphogenetic protein 2 for 0,12,24,and 48 hours,respectively.qRT-PCR was used to detect the mRNA expression levels of Atf7ip,alkaline phosphatase,osteocalcin,type I collagen α1 in the cells of each group.Western blot assay was used to detect the protein expression of osteogenic differentiation markers Sp7 and Runx2,and the expression of Atf7ip binding molecule SETDB1,histone H3 and H3K9me3.Alkaline phosphatase activity was detected by alkaline phosphatase staining. RESULTS AND CONCLUSION:(1)With the increase of bone morphogenetic protein 2 treatment time,the protein and mRNA expression of Atf7ip decreased,while the protein expression of Sp7,Runx2 and the mRNA expression of osteocalcin and alkaline phosphatase increased significantly(P<0.05).There was no significant change in the protein expression of Atf7ip binding molecule SETDB1.(2)Compared with the NC-siRNA group,the protein expression of Sp7,Runx2 and the mRNA expression of osteocalcin and type I collagen α1 were significantly up-regulated(P<0.05),and alkaline phosphatase activity was significantly enhanced;and H3K9 methylation significantly decreased in the Atf7ip-siRNA group(P<0.05).(3)Compared with the CMV-VC group,the protein expression of Sp7 and Runx,as well as mRNA expression of osteocalcin,alkaline phosphatase,and type I collagen α1 was significantly downregulated(P<0.05),and the alkaline phosphatase activity was significantly reduced in the CMV-Atf7ip group,while the H3K9 methylation protein in the CMV-Atf7ip group was significantly upregulated compared to the control group(P<0.05).(4)In conclusion,Atf7ip expression was decreased during bone morphogenetic protein 2-induced osteogenic differentiation of MC3T3-E1,and osteogenic differentiation was significantly increased after knockdown of Atf7ip.Overexpression of Atf7ip significantly weakened osteogenic differentiation,indicating that Atf7ip is a negative regulatory factor of bone morphogenetic protein 2 promoting osteogenic differentiation of MC3T3-E1 cells.

Background It has been reported that orthokeratology has the effects of slowing down myopia progression and axial elongation.However,the affecting mechanism of orthokeratology wearing on ocular peripheral refraction is still not elucidated.Objective This study was to observe and compare the changes of ocular peripheral refraction and relative peripheral refraction (RPR) in low to moderate myopic eyes of children after wearing orthokeratology lens and spectacles for 6 months.Methods A randomized controlled clinical trial was carried out after approval of Ethic Committee of Beijing Tongren Hospital and informed consent of guardians of the children.One hundred myopic children aged (ll.0±1.9) years were recruited in Beijing Tongren Hospital from June 2014 to January 2015,with the diopter of-0.50 to-6.00 D.The subjects were randomized into orthokeratology group and spectacles group by the process PLAN PROC of software SAS 9.1.3,50 for each group.The subjects in the orthokeratology group wore orthokeratology lens for 6 months and those in the spectacles group wore spectacles for the same period.An infrared open-field autorefractor was employed to measure the refraction at central 0°,temporal 15°,temporal 30°,nasal 15°and nasal 30° radial lines before and after wearing lens for the assessment and comparison of the changes of peripheral refraction and RPR.Results There was no significant difference in spherical equivalent between the orthokeratology group and the spectacles group before wearing lens ([-3.35±1.31] D versus [-3.01± 1.15] D,P =0.20).The peripheral refraction values in the orthokeratology group were (-2.28 ± 1.60),(-3.28±1.41),(-3.40±1.23),(-3.38±1.12) and (-2.09±1.29)D at nasal 15°and nasal30°,central,temporal 15° and temporal 30°radial lines before wearing lens,and reduced by (0.29±1.67),(0.85±1.66),(0.92±1.76) and (0.66±1.66) D at nasal 30°,nasal 15°,central and temporal 15° after wearing lens,respectively,with significant differences at nasal 15°,central and temporal 15°(all at P＜0.05).The peripheral refraction values in the spectacles group were (-1.88±1.30),(-2.66±1.18),(-2.89±1.27) and (-1.94±1.31)D at nasal 15°,nasal 30°,temporal 15 ° and temporal 30°,radial lines before wearing lens and increased by (-0.25±0.80),(-0.43 ±0.67),(-0.32±0.64) and (-0.22±0.75)D after wearing lens,respectively,with significant differences between before and after wearing lens (all at P＜0.05).The RPR shifted from hyperopia defocus to myopia defocus before and after wearing lens in temporal 15° and 30° radial lines in the orthokeratology group,and at various radial lines in the spectacles group,the RPR showed gradually worsening of hyperopia defocus.Conclusions Long-term wearing of orthokeratology results in a hyperopia shifting in myopic children by exposing the peripheral retina towards relative myopia defocus,whereas wearing spectacles leads to a relative hyperopia defocus on retina.Thus,orthokeratology may slow down the myopia progression.