| Research Basics Once diabetic retinopathy?DR?,one of the most serious complications of diabetes,occurs,patients' conditions progressively aggravate,and the treatment is relatively difficult and less effective.Proliferative diabetic retinopathy?PDR?occurs during the late stage of DR,and is often manifested as vitreous hemorrhage and tractional detachment of retina,with blindness in severe cases.Clinical observations and studies show that patients with high myopia,even with a long history of diabetes,do not often develop severe PDR;long axis oculi?mostly in high myopia?is a protective factor for DR.In recent years,domestic and foreign studies have shown that bone morphogenetic protein-2?BMP2?regulates the elongation of axis oculi by participating in scleral remodeling through the animal based experiment.Besides,BMP2,as a downstream factor of the transforming growth factor-beta?TGF-beta?regulatory pathway,exerts proinflammatory effects by increasing the secretion of the vascular endothelial growth factor?VEGF?indirectly,thus being involved in revascularization of ischemic tissues,and affects the function of the retinal tissue through a variety of links,thereby affecting the development and progression of DR.VEGF is the most studied cytokine which promotes angiogenesis and whose expression can be induced in hypoxia both in vitro and in vivo.It is also known currently as the cytokine most closely related to DR neovascularization,a turning point of the transformation from DR to PDR.Studies have shown that the concentration of VEGF in the vitreum of patients with high myopia and diabetes mellitus was significantly lower than that in the PDR group,and that the concentration of VEGF in patients with high myopia was significantly lower than that in non-diabetic patients.In addition,some scholars found that the concentration of VEGF was negatively correlated with the length of axis oculi.The human sclera retains the characteristics of cartilage,BMP2 and VEGF 165 play a role in the formation of bone,1?,25-dihydroxyvitamin D3 binds to vitamin D receptor?VDR?and further binds to BMP2 transcriptional regulatory region to inhibit the expression of BMP2 m RNA in different types of bone cells,thus affecting the formation of bone tissue.Foreign scholars have found through studies that deficiency or lack of serum 1?,25-dihydroxyvitamin D3 is an independent risk factor for the development and progression of DR and myopia?especially high myopia?.The insuffcient of serum 1?,25-dihydroxyvitamin D3 may cause pathological changes in the sclera through some biological pathways to elongate the axis oculi,thereby accelerating the process of myopia.Vitamin D deficiency and polymorphism of the VDR gene are significantly associated with high myopia.High levels of serum 1?,25-dihydroxyvitamin D3 are protective factors of DR because they may reduce the incidence of DR and delay the progression of DR.Objective In this study,the corresponding experimental groups were established,and the axial lengths of patients,the contents of BMP2 in the serum and vitreum,serum 1?,25-dihydroxyvitamin D3 and VEGF were measured,to explore the role of BMP2 in PDR,and to evaluate the significance and clinical value of BMP2 in predicting the development of DR.Methods 126 eyes of 126 cases of PDR patients,73 eyes of 73 cases of high myopia patients combined retinal detachment,and 37 eyes of 37 cases of patients with rhegmatogenous retinal detachment and relative emmetropia while no history of diabetes in need of 23 G standard three-channel vitrectomy who had been admitted to the ophthalmology department I of Zhengzhou University First Affiliated Hospital from March,2016 to February,2017 were selected,and their clinical case data were collected and sorted out,including age,sex,diabetes duration and other clinical data.They received conventional ophthalmology special examinations,including measurement of refraction,and the length of axis oculi using IOLMaster.The enrolled patients were subjected to sampling of venous blood and vitreous specimens,and the measurement of BMP2 in the serum and vitreum of the patients,and their serum 1?,25-dihydroxyvitamin D3 and VEGF,the data were sorted out and analyzed statistically.The differences in their expression levels among different groups were analyzed,the correlation of axial length with the contents of serum BMP2,1?,25-dihydroxyvitamin D3 and VEGF,the expression level of BMP2 in the vitreum and its correlation with axial length and the expression level in the serum were also analyzed.Result 1,The axial length of the control group?n=26?was 23.63±0.90 mm,the axial length of the high myopia group?n=65?was 28.67±2.20 mm,the length of the axial length of the PDR group?n=78?was 22.74±0.78 mm.The axial length of PDR group was lower than that of control group?P<0.05?,the axial length of PDR group and control group was lower than that of high myopia group?P<0.05?.2,The serum BMP2 concentration in the control group?n=9?was 1915.03±122.01 pg·ml-1,the serum BMP2 concentration in the high myopia group?n=15?was 1563.51±120.15 pg·ml-1,the serum BMP2 concentration in the PDR group?n=9?was 2081.24±322.91 pg·ml-1.The serum BMP2 concentration in the PDR group was higher than that in in high myopia group?P<0.05?,The serum BMP2 concentration in control group was higher than that in in high myopia group?P<0.05?, and the serum BMP2 concentration in PDR group was higher than that in control group?P>0.05?,the difference was not statistically significant.3,The concentration of BMP2 in the vitreous of the control group?n=15?was 1812.26±302.77 pg·ml-1,the concentration of BMP2 in the vitreous of the high myopia group?n=15?was 1535.16±159.77 pg·ml-1,the concentration of BMP2 in the vitreous of the PDR group?n=12?was 2269.08±284.50 pg·ml-1.The concentration of BMP2 in vitreous of PDR group was higher than that in control group?P<0.05?and high myopia group?P<0.05?,there was no statistically significant difference in BMP2 concentration in the vitreous of the high myopia group was lower than that in the control group?P>0.05?.4,The serum concentration of 1?,25-dihydroxyvitamin D3 was 72.17±17.29 nmol·L-1 in the control group?n=14?and in the high myopia group?n=17?was 53.35±14.87 nmol·L-1,The concentration of serum 1?,25-dihydroxyvitamin D3 in PDR group?n=69?was 49.21±20.46 nmol·L-1.The concentration of 1?,25-dihydroxyvitamin D3 in PDR group and high myopia group was lower than that in control group?P<0.05?,the concentration of 1?,25-dihydroxyvitamin D3 in PDR group was lower than that in high myopia group?P>0.05?,the difference was not statistically significant.5,The serum VEGF concentration in the control group?n=15?was 138.91±61.14 pg·ml-1,and in the high myopia group?n=17?was 191.44±84.73 pg·ml-1,the serum VEGF concentration was 211.75±145.47 pg·ml-1 in the PDR group?n=72?.The serum VEGF level in PDR group was higher than that in high myopia group,and the serum VEGF level in high myopia group was higher than that in control group?P=0.282?,the difference was not statistically significant.6,There was a negative correlation between the BPM2 concentration in vitreous and the axial length?r=-0.602,P=0.030?,there was a positive correlation between age and diabetes mellitus in PDR group?r=0.266,P=0.003?,and there was a positive correlation between serum VEGF concentration and duration of diabetes mellitus?r=0.282,P=0.016?.Conclusions 1,In PDR group,the concentration of BMP2 was significantly higher than that in control group and high myopia group,suggesting that BMP2 was involved in the development of DR.2,In PDR group,the concentration of BMP2 in vitreous was higher than that in high myopia group,the axial length of high myopia group was higher than that of PDR group,and there was a negative correlation between the BPM2 concentration in vitreous and the axial length,suggesting that BMP2 might affect the occurrence of DR by affecting the axial length.3,The patients of PDR and high myopia with low levels of serum 1?,25-dihydroxyvitamin D3 expression,suggesting that the deficiency or lack of 1?,25-dihydroxyvitamin D3 are related to the occurrence and development of DR and high myopia. |
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