Expression Of PRX1 And GLI1 In The Expanding Premaxillary Suture Of Rats

OBJECTIVES: PRX1 and GLI1 are markers of craniofacial skeletal stem cells.The purpose of this study was to observe the expression of PRX1 and GLI1 during development and expansion of rat premaxillary suture.METHODS: Eight 4-week-old male SD rats were subjected to premaxillary suture expansion by a helix spring on the upper incisors for 1 day,after which Ed U was injected.Then they were divided into two groups and sacrificed 3 hours and 2 days(n = 4)after the injection respectively.Another 9male SD rats of 1,2,4 weeks were utilized as normal development control group(n=3 each age).After decalcification and paraffin embedding,the sections of premaxillary suture were taken.The histomorphology was observed by HE staining.The expression of PRX1 and GL11 was detected by immunohistochemistry.The proliferation cells were labeled by Ed U fluorescence.RESULTS: During the development of rats,PRX1 was widely expressed in the osteoblasts and pre-osteoblasts at the edge of premaxillary suture while GLI1 was dispersedly expressed in the suture mesenchyme cells.After 1 day of expansion,the width of the suture widened,and the number of PRX1 or GLI1 positive cells in the suture increased.After 3 days of expansion,PRX1 and GLI1 positive cells appeared in the newly formed osteoid.Ed U positive proliferating cells were localized in the margin and mesenchyme of the suture.The number of proliferating cells in premaxillary suture increased after the expansion,and some proliferating cells are positive for PRX1 or GLI1.CONCLUSION: PRX1 and GLI1 are expressed in the mesenchymal cells and osteoprogenitor cells in the premaxillary suture.Skeletal stem cells may contribute to the development and osteogenesis during expansion of the premaxillary suture.