Research The Effects Of Lactoferrin On Expressions Of IGF-IR/IGFBP-2/IGFBP-4 MRNA In Ovariectomized Rats

Objective :This study evaluated the effect of lactoferrin(LF) on IGF-1R,IGFBP-2 and IGFBP-4 gene expression of ovariectomized(Ovx) rat model, and to discuss the mechanism that lactoferrin mediate the anabolic in bone through the gene expression of IGF-1R,IGFBP-2 and IGFBP-4. Methods:Seventy female Sprague-Dawley rats about six-month-old were separated into the following groups(each group n=10) randomly: Bovine Serum Albumin(BSA) 100mg/kg/d+disstilled water 2ml,Ovx untreated(Ovx); Ovx+LF 100mg/kg/d +disstilledwater2ml(LF1);Ovx+LF1g/kg/d+disstilledwater2ml(Ovx+LF2);Ovx+LF2.0g/kg/d+disstilled water 2ml(LF3); Ovx+17β-estradiol 0.1 mg/kg/wk(E2),sham-operated(Sham).After 6 months of treatment,the weight of before and after different concentration of lactoferrin(LF) intervention was measured.By making HE paraffin pathology slice, using microscope to observe bone structure change.Through q RT-PCR namely quantitative real-time reverse transcription PCR, the levels of Insulin-like Growth Factor binding protein 2(IGFBP-2), the Insulin-like Growth Factor binding protein 4(IGFBP-4),the Insulin-like Growth Factor-I Receptor(IGF-1R)m RNA were obtained in the left femur. Results:1. Before the treatment,there were not significantly different from the body weights of the rats(P>0.05). After the 6-month experiment,in addition to the estrogen group,the body weight had been increased to the other groups. Compare with the E2 and Sham rats,the Con rats tended to increase more weight(P<0.05). The weight gained most is con group.The weights of the LF-treated rats were lower than the weights of the Con group,so we can say, the were not statistically significant(P>0.05).2.The pathological bone biopsy showed HE dyeing:The permutation of the Sham group and E2 group trabecular bone is dense and full,small spacine,more cell numbers.While Con group and BSA group, trabecular bone become thinner widened distance,sparse,less cell number,appeared large blank area.LF-treated group(LF1,LF2 and LF3) fall in between the two,and tightness of trabecular bone permutation LF3 is better than LF2,LF2 is better than LF1.So we can concluded that ovary osteoporosis rats model was builded successfully.3.We can receive the consequence of real-time fluorescence quantitative polymerase chain reaction(PCR) that treatment with100 mg/kg,1 g/kg, 2 g/kg LF, E2 and BSA. It caused a significant decrease in the IGFBP-2、 IGFBP-4 m RNA levels. While,there is a significance increase in the IGF-1R,treated with100mg/kg and 1 g/kg,2 g/kg LF and E2, compared with the Con group(P<0.01). In addition, the IGF-1R 、IGFBP-2、 IGFBP-4 m RNA levels were basically unchanged treated with Bovine Serum Albumin(BSA) 100mg/kg/d(P>0.05). Conclusion:1.We gained the replication animal model of osteoporosis successfully.2.Lactoferrin can promote IGF-1R but inhibit IGFBP-2 and IGFBP-4 gene’s expression in osteoblasts. Lactoferrin may have received via function in bone through the IGF-1R/ IGFBP-2/ IGFBP-4 pathway.