| Objectives Observe the effect of Wnt5 a gene knockout on the bone mass and microstructure of mouse osteoblasts,and specifically remove the bilateral ovaries of Wnt5 a female mice by excising osteoblasts to establish postmenopausal osteoporosis(PMOP)model to explore the effect of this gene knockout on PMOP bone loss.Methods Twelve 8-week-old osteoblast-derived Wnt5 a transgenic mice and 12 8-weekold wild-type mice born in the same litter without Cre were randomly divided into a sham operation group and an ovarian model group,namely the wild type sham operation group(WTS group),wild type model group(WTM group),transgenic sham operation group(KOS group),transgenic model group(KOM group),a total of 6 groups.The model group underwent bilateral oophorectomy and the sham operation group underwent sham operation.The mice in each group were weighed weekly.After 8 weeks,they were sacrificed and specimens were collected for relevant tests,including fallopian tube and uterine weight,body weight,abdominal fat weight,and HE staining to verify the success of ovarian removal surgery;Micro-CT analysis,three-point bending experiment,HE staining to analyze bone mass,bone micro Structure and bone biomechanical properties;TRAP staining to detect the number of osteoclasts;immunohistochemical staining to detect the expression of Wnt5 a,ROR2,OPG,RANKL in mature osteoblasts.Results The weight of fallopian tube and uterus and abdominal fat showed that: WTM group was significantly lower than WTS group(P<0.05)and KOS group(P<0.05),KOM group was significantly lower than WTS group(P<0.05)and KOS group(P<0.05).Adipose tissue HE staining showed that the WTM group and the WTS group,KOM and KOS than the fat cells increased compensatory,but the KOS group and the WTS group,the KOM group and the WTM group had no significant difference in the size and number of fat cells.Body weight display: The body weight of the model group was significantly increased compared with the sham operation group(P<0.05),and the body weight of the transgenic mice was not statistically different from that of the wild-type mice(P>0.05).Micro-CT results showed that WMD group had significantly lower BMD,BV/TV,Tb.N,Ct.Ar,and Ct.Th than WTS group and KOM group than KOS group(P<0.05),while Tb.Sp and Tb.pf,Ct.Po was significantly increased(P<0.05);compared with WTM group,Tb.Sp in KOM group was significantly increased(P<0.05).The three-point bending results showed that the model group had significantly lower maximum load,maximum stress and maximum radius than the sham operation group(P<0.05),and the KOS group and the WTS group had significantly lower maximum stress(P<0.05).HE staining of the distal femur showed that the bone microstructure in the WTS group was normal,the bone mass was significantly lost,the bone microstructure was abnormally changed in the WTM and KOM groups,and the microstructure in the KOS group was slightly changed.TRAP staining results showed that the number of positive cells in the WTM group was significantly higher than that in the WTS group(P<0.05),the number of positive cells in the KOM group was significantly higher than that in the KOS group(P<0.05),and the number of positive cells in the KOS group was significantly lower than that in the WTS group(P<0.05),the number of positive cells in the KOM group was significantly lower than that in the WTM group(P<0.05).The results of immunohistochemical staining showed that the average optical density of Wnt5 a and ROR2 in WTM group was significantly higher than that of WTS group(P<0.05);the average optical density of Wnt5 a and ROR2 in KOS group and KOM group was not statistically different(P>0.05);KOS group Compared with WTS group,the average optical density of Wnt5 a and ROR2 was significantly reduced(P<0.05);compared with WTM group,the average optical density of Wnt5 a and ROR2 was significantly reduced(P<0.05).Compared with the WTS group,the average optical density of OPG and RANKL in the WTM group was significantly increased(P<0.05).The average optical density of the OPG and RANKL was significantly increased in the KOM group and the KOS group(P<0.05).The KOS group was compared with the WTS group.Compared with OPG and RANKL,the average optical density decreased significantly(P<0.05).Compared with the WTM group,the average optical density of OPG and RANKL in the KOM group was significantly reduced(P<0.05).Conclusions The bilateral ovariectomy in mice successfully established the PMOP model and induced bone loss;the experimental results showed that the osteoblast-specific knockout of the Wnt5 a gene had no significant effect on bone mass under normal physiological and estrogen deficiency-induced bone loss.But slightly change the bone microstructure.Figure 18;Table 4;Reference 104... |
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