Bone tissue regeneration holds the potential to solve both osteoporosis and large skeletal defects,two problems associated with significant morbidity.The differentiation of mesenchymal stem cells into the osteogenic l...Bone tissue regeneration holds the potential to solve both osteoporosis and large skeletal defects,two problems associated with significant morbidity.The differentiation of mesenchymal stem cells into the osteogenic lineage requires a specific microenvironment and certain osteogenic growth factors.Neural EGF Like-Like molecule 1(NELL-1)is a secreted glycoprotein that has proven,both in vitro and in vivo,to be a potent osteo-inductive factor.Furthermore,it has been shown to repress adipogenic differentiation and inflammation.NELL-1 can work synergistically with other osteogenic factors such as Bone Morphogenic Protein(BMP)2 and9,and has shown promise for use in tissue engineering and as a systemically administered drug for the treatment of osteoporosis.Here we provide a comprehensive up-to-date review on the molecular signaling cascade of NELL-1 in mesenchymal stem cells and potential applications in bone regenerative engineering.展开更多
Background Tissue engineering techniques combined with gene therapy have been recently used to improve osteogenesis. NEL-like molecule-1 （Nell-1）, a novel growth factor, has been reported to have specificity for ost...Background Tissue engineering techniques combined with gene therapy have been recently used to improve osteogenesis. NEL-like molecule-1 （Nell-1）, a novel growth factor, has been reported to have specificity for osteochondral lineage. The study assessed the osteogenic differentiation of rat bone marrow stromal cells （bMSCs） after Nell-1 gene modification and examined its ectopic bone formation ability in a nude mice model with tissue engineering technique. Methods bMSCs obtained from Fischer 344 rats were transduced with either AdNell-1 （Nell-1 group） or Ad-β-galactosidase （AdLacZ, LacZ group） or left untransduced （untransduced group）. The expression of Nell-1 protein was determined by Western blotting and transfer efficiency was assessed, mRNA expressions of osteopontin （OP）, bone sialoprotein （BSP） and osteocalcin （OC） were assessed by real-time PCR 0, 3, 7, 14, and 21 days after gene transfer. Alkaline phosphatase （ALP） activity was measured and von Kossa test was also conducted. Finally, with a tissue engineering technique, gene transduced bMSCs, combining with β-tricalcium phosphate （β-TCP） at a concentration of 2×10^7 cells/ml, were implanted at subcutaneous sites on the back of nude mice. Four weeks after surgery, the implants were evaluated with histological staining and computerized analysis of new bone formation. Results Under current transduction conditions, gene transfer efficiency reached （57.9±6.8）%. Nell-1 protein was detected in Nell-1 group but not in untransduced group and LacZ group. Induced by Nell-1, BSP and OP expression were increased at intermediate stage and OC expression was increased at later stage. ALP activity and the number of calcium nodules were highest in Nell-1 group. Four weeks after implanted into nude mice subcutaneously, the percentage of new bone area in Nell-1 group was （18.1±5.0）%, significantly higher than those of untransduced group （11.3±3.2）% and LacZ group （12.3±3.1）% （P〈0.05）. Conclusions This study has demonstrated the ability of Nell-1 to induce osteogenic differentiation of rat bMSCs in vitro and to enhance bone formation with a tissue engineering technique. The results suggest that Nell-1 may be a potential osteogenic gene to be used in bone tissue engineering.展开更多
The purposes of this study were to construct a novel tissue engineered bone composed of 3Dprinted bioactive glass block/chitosan nanoparticles(BD/CSn)composites loaded with Nel-like Type I molecular-1 DNA(pDNA-NELL1)a...The purposes of this study were to construct a novel tissue engineered bone composed of 3Dprinted bioactive glass block/chitosan nanoparticles(BD/CSn)composites loaded with Nel-like Type I molecular-1 DNA(pDNA-NELL1)and/or bone marrow mesenchymal stem cells(BMSCs),and study their osteogenic activities by repairing bone defects in rhesus monkeys.CSn with NELL1 gene plasmid and rhesus monkey BMSCs were composited with a BD scaffold to prepare the tissue-engineered bone.Four adult female rhesus monkeys with 10-to 12-years old and 5-7 kg in weight were used in animal experiments.The first and second premolar teeth from four regions of each monkey were removed to form bone defects with size of 10×10×5 mm,which were then implanted with above-mentioned tissue engineered bone.At 12 weeks after the implantation,gross observations,X-ray and micro-CT observations revealed that the new bone was extremely close to normal bone in mass,density,hardness,and structure.The bony cortex was smooth and closely connected to the surrounding normal bone.Histological observations revealed moderate inflammation in the repair area,and the new bone tissues were similar to normal ones.In conclusion,tissue engineered bone of this study exhibited good osteoconductivity for promoting the formation of new alveolar bone tissue,and NELL1 gene played a promotional role in bone regeneration.展开更多
基金Research in the authors’laboratories was supported in part by research grants from the National Institutes of Health(AT004418,DE020140 to TCH and RRR)the US Department of Defense(OR130096 to JMW)+4 种基金the Scoliosis Research Society(TCH and MJL)the 973 Program of the Ministry of Science and Technology(MOST)of China(#2011CB707906 to TCH)MP and SM were recipients of the Pritzker Summer Research Fellowship funded through the National Institute of Health(NIH)T-35 training grant(NIDDK)#T35DK062719-30The reported work was also supported in part by The University of Chicago Cancer Center Support Grant(P30CA014599)the National Center for Advancing Translational Sciences of the National Institutes of Health through Grant Number UL1 TR000430。
文摘Bone tissue regeneration holds the potential to solve both osteoporosis and large skeletal defects,two problems associated with significant morbidity.The differentiation of mesenchymal stem cells into the osteogenic lineage requires a specific microenvironment and certain osteogenic growth factors.Neural EGF Like-Like molecule 1(NELL-1)is a secreted glycoprotein that has proven,both in vitro and in vivo,to be a potent osteo-inductive factor.Furthermore,it has been shown to repress adipogenic differentiation and inflammation.NELL-1 can work synergistically with other osteogenic factors such as Bone Morphogenic Protein(BMP)2 and9,and has shown promise for use in tissue engineering and as a systemically administered drug for the treatment of osteoporosis.Here we provide a comprehensive up-to-date review on the molecular signaling cascade of NELL-1 in mesenchymal stem cells and potential applications in bone regenerative engineering.
基金This study was supported by grants from National Natural Science Foundation of China （No. 30400502 and 30772431）, Program for New Century Excellent Talents in University （NCET-08-0353）, Science and Technology Commission of Shanghai Municipality （No. 07DZ22007, 08410706400, 08JC1414400, and 08QH1401700）, Shanghai Rising-star Program （No. 05QMX1426）, and Shanghai Education Committee （No. 07SG 19）.
文摘Background Tissue engineering techniques combined with gene therapy have been recently used to improve osteogenesis. NEL-like molecule-1 （Nell-1）, a novel growth factor, has been reported to have specificity for osteochondral lineage. The study assessed the osteogenic differentiation of rat bone marrow stromal cells （bMSCs） after Nell-1 gene modification and examined its ectopic bone formation ability in a nude mice model with tissue engineering technique. Methods bMSCs obtained from Fischer 344 rats were transduced with either AdNell-1 （Nell-1 group） or Ad-β-galactosidase （AdLacZ, LacZ group） or left untransduced （untransduced group）. The expression of Nell-1 protein was determined by Western blotting and transfer efficiency was assessed, mRNA expressions of osteopontin （OP）, bone sialoprotein （BSP） and osteocalcin （OC） were assessed by real-time PCR 0, 3, 7, 14, and 21 days after gene transfer. Alkaline phosphatase （ALP） activity was measured and von Kossa test was also conducted. Finally, with a tissue engineering technique, gene transduced bMSCs, combining with β-tricalcium phosphate （β-TCP） at a concentration of 2×10^7 cells/ml, were implanted at subcutaneous sites on the back of nude mice. Four weeks after surgery, the implants were evaluated with histological staining and computerized analysis of new bone formation. Results Under current transduction conditions, gene transfer efficiency reached （57.9±6.8）%. Nell-1 protein was detected in Nell-1 group but not in untransduced group and LacZ group. Induced by Nell-1, BSP and OP expression were increased at intermediate stage and OC expression was increased at later stage. ALP activity and the number of calcium nodules were highest in Nell-1 group. Four weeks after implanted into nude mice subcutaneously, the percentage of new bone area in Nell-1 group was （18.1±5.0）%, significantly higher than those of untransduced group （11.3±3.2）% and LacZ group （12.3±3.1）% （P〈0.05）. Conclusions This study has demonstrated the ability of Nell-1 to induce osteogenic differentiation of rat bMSCs in vitro and to enhance bone formation with a tissue engineering technique. The results suggest that Nell-1 may be a potential osteogenic gene to be used in bone tissue engineering.
基金This work is in part supported by China Postdoctoral Science Foundation funded project(No.2013M540787).
文摘The purposes of this study were to construct a novel tissue engineered bone composed of 3Dprinted bioactive glass block/chitosan nanoparticles(BD/CSn)composites loaded with Nel-like Type I molecular-1 DNA(pDNA-NELL1)and/or bone marrow mesenchymal stem cells(BMSCs),and study their osteogenic activities by repairing bone defects in rhesus monkeys.CSn with NELL1 gene plasmid and rhesus monkey BMSCs were composited with a BD scaffold to prepare the tissue-engineered bone.Four adult female rhesus monkeys with 10-to 12-years old and 5-7 kg in weight were used in animal experiments.The first and second premolar teeth from four regions of each monkey were removed to form bone defects with size of 10×10×5 mm,which were then implanted with above-mentioned tissue engineered bone.At 12 weeks after the implantation,gross observations,X-ray and micro-CT observations revealed that the new bone was extremely close to normal bone in mass,density,hardness,and structure.The bony cortex was smooth and closely connected to the surrounding normal bone.Histological observations revealed moderate inflammation in the repair area,and the new bone tissues were similar to normal ones.In conclusion,tissue engineered bone of this study exhibited good osteoconductivity for promoting the formation of new alveolar bone tissue,and NELL1 gene played a promotional role in bone regeneration.
