RESUMO
[Objective]To investigate the rlpairing effect on articular cartilage defects by composite of cocultures of autogenic bone marrow-derived mesenchymal stem cells(BMSCs) and chondrocytes with allogenic fully deproteinized bone(FDB),in order to provide basis for optimizing seeding cells resources.[Method]Seeding cells were collected from two-passaged BMSCsand chondroeytes and then cocultured at the rate of 2 to 1.Full thickness articular cartilage defects in the knee joints of rabbits repaired by cocultured cells seeded into allogenic FDB were served as experimental group A,by simple FDB as control group B and by nothing as blank control group C.Repaired tissues were evaluated with macroscopic views,histological scores and immunohistochemistrical stains at 8 and 16 weeks postoperatively.[Result]Chondrocytes cocultured riched in extracellular matrix and proliferated promptly.In A regenerated tissues represented hyaline-like,smoothness and flat.In group B and C,repaired tissues were fiberous and no repaire in group C.Histological scores of experimental group A excelled group B and C with statistically significant differences(P0.05).Immunohistochemistrical stains showed that cells in the zones of repaired tissues were larger in size,arranged columnnedly,riched in type-Ⅱ collagen matrix and integrated satisfactorily with native adjacent cartilages and subchondral bones in the experimental group A at 16 weeks postoperatively.[Conclusion]Cocultures of autogenic BMSCS with chondrocytes can promote proliferation of chondrocytes and production of chondral matrix.Cocultures as seeding cells can save a number of chondrocytes,shorten culturing periods and reduce subcultured times.Cocultures embedded into FDB can repair articular cartilage defects effectively.
RESUMO
Aim To investigate the role of p38 mitogen-activated protein kinases(MAPKs) in genistein-induced osteoblastic differentiation of mouse bone marrow-derived mesenchymal stem cells(BMSCs).Methods Mouse BMSCs cultured in phenol red-free ?-MEM containing 10% V/V FBS,were added ?-glycerophosphate and ascorbic acid for inducing osteoblastic differentiation,and treated with 0.01~1 ?mol?L~(-1) genistein and/or SB203580 and PD98059.The temporal sequence of osteoblastic differentiation in BMSCs cultures was assayed by measuring alkaline phosphatase activity(ALP) and calcium deposition.The MAPK phosphorylation level was detected by Western-blot.Results Genistein(0.01~1 ?mol?L~(-1)) showed a dose-dependent effect on osteoblastic differentiation as evidenced by increased alkaline phosphatase(ALP) activity and calcium deposition in mouse BMSCs cultures.Genistein(1 ?mol?L~(-1))-induced osteoblastic differentiation of BMSCs was diminished by p38 MAPK inhibitor but not the p44/42 MAPK inhibitor.The effects of Genistein were associated with rapid and sustained activation of p38 MAPK in the BMSCs cultures,which was blocked by SB203580(1 ?mol?L~(-1)).In contrast,Genistein treatment resulted in inactivation of p42/44MAPK,which was further attenuated by PD98059(25 ?mol?L~(-1)).Conclusion p38 MAPK plays an important role in genistein-induced osteoblastic differentiation of mouse BMSCs cultures.