Objective To study the effects of the periosteum，synovium andcartilage tissues on the gene expressions of proteoglycan, collagen Ⅱ, andnuclear factor kappa B (NF-κB) and to investigate the different effects of these tissues on cartilage regeneration. Methods In 20 New Zealand white rabbits, 20 cartilage explants were taken from the knee joints in each rabbit, the sizeof which was 4 mm×4 mm×4 mm. All the cartilages were divided into the following 4 groups and cultured for 7 days: Group A, with 5 pieces (2 mm×2 mm) of the synovium of theknee joints in each dish; Group B, with 5 pieces (2 mm×2 mm) of the periosteum ineach dish; Group C, with 5 pieces (2 mm×2 mm×2 mm) of the cartilage in each dish; and Group D, with no addition of other tissues (control group). RNA was extracted from the cells of the cartilage explants (4 mm×4 mm×4 mm) in all the dishes. Thegene expressions of proteoglycan, collagen Ⅱ and NF-κB were defected by a reversetranscription-polymerase chain reaction (RT-PCR).Results In group A, the gene expression of proteoglycan was significantly decreased. The relative density of this gene expression had a significant difference when compared with that in group D (1.09±0.21 vs. 1.25±0.25, Plt;0.05); the gene expressions of collagen Ⅱ and NF-κB were also decreased, but they had no significant differences when compared with those in group D (Pgt;0.05). In groupB, the gene expressions of proteoglycan, collagen Ⅱ, and NF-κB were significantly increased. The relative densities of these gene expressions were 1.60±0.26, 1.57±0.24, and 4.20±2.22, respectively, which had significant differences when compared with those in group D (Plt;0.05). In group C, the relative density of the gene expression of collagen Ⅱ was 1.43±0.28, which had a significant difference when compared with that in group D (Plt;0.05), but therelative densities of the gene expressions of proteoglycan and NF-κB had no significant differences when compared with those in group D (Pgt;0.05). Conclusion The results indicate that the periosteum can up-regulate the gene expressions of proteoglycan, collagen Ⅱ and NF-κB. The NF-κB is likely to be an important nuclear transcription factor related to cartilage regeneration. The results also suggest that the periosteum maybe better in facilitating the cartilage repair and regeneration in clinical practice.
Objective To study the differentiation of the human osteoblasts during the construction of the tissue engineered periosteum with the human acellular amniotic membrane(HAAM).Methods To construct the tissue engineered periosteum (n=60) with HAAM, the human fetal osteoblasts were used. The fetal osteoblasts were cultured for 2, 4, 6, 8, and10 days, and then their total RNA was extracted, which were reversely transcripted to cDNA. The realtime PCR analysis was used to reveal Cbfal and Osterix, and the cycle threshold (Ct) was also measured. The simplycultured osteoblasts were used as the control group (n=20).Results The expression of Cbfa1 was higher in the experimental group on the 2nd day when compared with that on the 4th, 6th, and 8th day(P＜0.05). The same result existed on the 10th day when compared with that on the 4th and 8th day. The expression of Osterix increased and was highest on the 8th day when compared with the other results(P＜0.05). Both of the 2 gene expressions were decreased in the control group when compared with those in the experimental group, but with no significant difference(P＞0.05). Conclusion Cbfa1 and Osterix can be normally expressed by the osteoblasts after their integration with HAAM. As a scaffold, HAAM can be used to keep the osteoblast phenotype and differentiation with an osteoconductive ability. Such a cell-scaffold complex may provide a basis for the osteogenesis.