The Correlation Study Of Serum Sclerostin Level And WNT Signaling Pathway In The T2DM Patients With Femur Fracture

Background:Hyper-glycemia is the leading barrier to fracture healing since high blood sugar may promote cartilage cell apoptosis and osteoclast differentiation,as well as reduce the osteogenesis and endochondral ossific.Nevertheless,it remains unknown about the serum levels of sclerostin and other bone formation and remodeling-associated biomarkers,such as Osteocalcin,PINP and ?-CTX in the T2DM patients.The increased circulating sclerostin is also associated with the atherosclerotic lesions in T2DM patients,via modulating Wnt signaling pathway.Moreover,the increased sclerostin production in men with T2DM may be involved in the pathogenesis of increased skeletal fragility.Objectives:?.To determine the candidate key factors involved in bone formation andremodeling.For this purpose,the contents of bone turnover biomarkers(sclerostin,Osteocalcin,PINP and ?-CTX)were assessed and compared in hospitalized femoral fractures patients with T2DM and without T2DM.ii.To determine whether or not sclerostin can regulate the expression of Osteocalcin,PINP and ?-CTX.iii.To understand whether or not sclerostin regulates the bone formation via Wnt signaling pathway.iv.To detecte the change rule of osteocalcin,PINP and ?-CTX,we need to silence?-catenin of hFOB 1.19,then we may provide new targets for drug treatment of diabetes's fracture healing.Materials and Methods:A total of 59 patients with femoral fratures were recruited between June 2014 and June 2015 from in the department of orthopaedics,Hohhot hospital of Inner Mongolia.Among them,32 patients were associated with type 2 diabetes,whereas others were not.All patients in the emergency department were extracted vein blood samples.Osteocalcin,sclerostin,PINP and ?-CTX were measured with Enzyme-linked immunosorbent method(Elisa).Human osteoblast hFOB 1.19 were purchased from the Chinese academy of medical sciences cell center,and the cells were cultured with medium(DMEM).The quantitatively real-time PCR(qRT-PCR)was used to analysis the mRNA expression of Osteocalcin,PINP and ?-CTX in the hFOB 1.19 treated with sclerostin.Werstern blot analysis was used to detect the expression of ?-catenin and phosphorylated ?-catenin in human osteoblast hFOB 1.19 treated with sclerostin and wnt agonist,respectively.In order to confirm whether or not sclerostin downregulates the expression of Osteocalcin,PINP and P-CTX via Wnt signaling pathway in hFOB 1.19,?-catenin expression were knocked down through transfection of siRNA-?-catenin into hFOB 1.19 cells,and qRT-PCR was subsequently used to analysis the mRNA expression of Osteocalcin,PINP and ?-CTX in the transfected hFOB 1.19.ResultsThe level of sclerostin in the femur fracture patients with T2DM was significantly higher than those without T2DM.On the contrary,however,the levels of Osteocalcin,PINP and ?-CTX in the femur fracture patients with T2DM were significantly lower than those without T2DM.The mRNA levels of Osteocalcin,PINP and ?-CTX in hFOB 1.19 cells were significantly decreased after treated with different concentration of Sclerostin.The protein level of P-catenin in cytoplasm of hFOB 1.19 cells was no significantly changed,whereas,the phosphorylated ?-catenin(Ser675)in the cytoplasm was significantly downregulated by the Wnt agonist,and significantly upregulated by sclerostin.The mRNA level of ?-catenin,Osteocalcin,PINP and?-CTX in hFOB 1.19 cells were significantly decreased after transfected with different concentration of siRNA-?-catenin.Conclusions?.In the early stage of femur fracture healing,the level of sclerostin in the femur fracture patients with T2DM was significantly higher than in the femur fracture patients without T2DM.On the contrary,the levels of Osteocalcin,PINP and?-CTX in the femur fracture patients with T2DM were significantly lower.The results suggested that sclerostin may be involved in bone formation and remodeling in T2DM-associated fracture healing.?.Sclerostin can downregulate the mRNA levels of Osteocalcin,PINP and P-CTX in hFOB 1.19 cells after treated with different concentration of Sclerostin.The results suggested that sclerostin may regulate the expression of Osteocalcin,PINP and ?-CTX.?.Sclerostin can upregulate the protein level of p-?-catenin in a concentration dependent manner.The results suggested that sclerostin may regulate the bone formation via Wnt signaling pathway.?.Low expression of ?-catenin can downregulate the mRNA levels of Osteocalcin,PINP and ?-CTX in hFOB 1.19 cells.The results suggested that sclerostin may regulate the protein level of p-?-catenin via Wnt signaling pathway to impact the expression of osteocalcin,PINP and p-CTX.