Peptides from Pilose antler aqueous extract(PAAE) have been shown to stimulate the proliferation and differentiation of bone marrow mesenchymal stem cells(BMSCs). However, the underlying molecular mechanisms are not w...Peptides from Pilose antler aqueous extract(PAAE) have been shown to stimulate the proliferation and differentiation of bone marrow mesenchymal stem cells(BMSCs). However, the underlying molecular mechanisms are not well understood. Here, PAAE was isolated and purified to explore the molecular mechanisms underlying PAAE’s effects on BMSCs as well as its osteoprotective effects in ovariectomized rats. Our results showed that PAAE promoted proliferation and differentiation of BMSCs to become osteoblasts by enhancing ALP activity and increasing extracellular matrix mineralization. The trabecular microarchitecture of ovariectomized rats was also found to be protected by PAAE. Quantitative reverse transcription-polymerase chain reaction(Quantitative RT-PCR) results suggest that PAAE also increased the expression of osteogenic markers including, alkaline phosphatase(ALP), runt-related transcription factor 2(Runx2), osteocalcin(OCN), bone morphogenetic protein-2(BMP-2), and collagen I(COL-I). Immunoblotting results indicated that PAAE upregulated the levels of BMP-2 and Runx2 and was associated with Smad1/5 phosphorylation. PAAE A at the concentration of 200μg·mL^-1 showed the strongest effect on proliferation and osteogenic differentiation of BMSCs after 48 h. Using matrix-assisted laser desorption/ionization time of flight mass spectrometry(MALDI-TOF MS), we identified the molecular weight of PAAE A and found that it is less than 3000 Da and showed several significant peaks. In conclusion, PAAE activates the BMP-2/Smad1, 5/Runx2 pathway to induce osteoblastic differentiation and mineralization in BMSCs and can inhibit OVX-induced bone loss. These mechanisms are likely responsible for its therapeutic effect on postmenopausal osteoporosis.展开更多
Adult bone structural integrity is maintained by remodeling via the coupling of osteoclastic bone resorption and osteoblastic bone formation.Osteocytes or osteoblasts express receptor activator of nuclear factor k-B l...Adult bone structural integrity is maintained by remodeling via the coupling of osteoclastic bone resorption and osteoblastic bone formation.Osteocytes or osteoblasts express receptor activator of nuclear factor k-B ligand(Rankl)or osteoprotegerin(Opg)to promote or inhibit osteoclastogenesis,respectively.Bone morphogenetic protein(BMP)is a potent bone inducer,but its major role in adult bone is to induce osteocytes to upregulate sclerostin(Sost)and increase the Rankl/Opg expression ratio,resulting in promotion of osteoclastogenesis.However,the precise effect of BMP-target gene(s)in osteoblasts on the Rankl/Opg expression ratio remains unclear.In the present study,we identified atonal homolog 8(Atoh8),which is directly upregulated by the BMPSmadl axis in osteoblasts.In vivo,Atoh8 was detected in osteoblasts but not osteocytes in adult mice.Although global Atoh8-knockout mice showed only a mild phenotype in the neonate skeleton,the bone volume was decreased and osteoclasts were increased in the adult phase.Atoh8-null marrow stroma cells were more potent than wild-type cells in inducing osteoclastogenesis in marrow cells.Atoh8 loss in osteoblasts increased Runx2 expression and the Rankl/Opg expression ratio,while Runx2 knockdown normalized the Rankl/Opg expression ratio.Moreover,Atoh8 formed a protein complex with Runx2 to inhibit Runx2 transcriptional activity and decrease the Rankl/Opg expression ratio.These results suggest that bone remodeling is regulated elaborately by BMP signaling;while BMP primarily promotes bone resorption,it simultaneously induces Atoh8 to inhibit Runx2 and reduce the Rankl/Opg expression ratio in osteoblasts,suppressing osteoclastogenesis and preventing excessive BMP-mediated bone resorption.展开更多
二膦酸盐不仅特异性抑制破骨细胞,同时对成骨细胞也起一定的作用.用酶消化法取乳鼠颅盖骨进行成骨细胞培养,分为空白对照组、阿仑膦酸钠高、中、低剂量组.从BMP-2/Smads/Runx2/Osterix信号通路角度观察二膦酸盐对成骨细胞分化的作用.结...二膦酸盐不仅特异性抑制破骨细胞,同时对成骨细胞也起一定的作用.用酶消化法取乳鼠颅盖骨进行成骨细胞培养,分为空白对照组、阿仑膦酸钠高、中、低剂量组.从BMP-2/Smads/Runx2/Osterix信号通路角度观察二膦酸盐对成骨细胞分化的作用.结果显示:比色法结果显示干预2和4d后各剂量阿仑膦酸钠组的碱性膦酸酶(AKP)显著增加,其中中剂量组表达最高,各组明显高于空白对照组(p<0.05),第6天各剂量阿仑膦酸钠组AKP逐渐下降,与空白对照组比较,无统计学意义(p>0.05);ELISA结果显示随着天数增加各剂量阿仑膦酸钠组的BMP-2逐渐增加,其中中剂量组表达最高,各组明显高于空白对照组(p<0.05),干预2和4d后各剂量阿仑膦酸钠组的I型胶原(Collagen Type I)显著增加,其中中剂量组表达最高,各组明显高于空白对照组(p<0.05),第6天各剂量阿仑膦酸钠组Collagen Type I逐渐下降,空白对照组随着天数逐渐增加,但均低于同时期用药组(p<0.05);荧光定量PCR(qPCR)检测结果显示BMP-2、Smad1/5、Runx2和Osterix mRNA表达在干预后,随着时间的延长,逐渐上升;阿仑膦酸钠组的含量高于同期的空白对照组.提示阿伦膦酸钠能刺激成骨细胞增殖,增强BMP、AKP活性,通过BMP-2/Smads/Runx2/Osterix通路上调相关基因表达,促进成骨细胞分化.展开更多
Osteoarthritis (OA) is a debilitating chronic joint disease affecting large populations of patients, especially the elderly. The pathological mechanisms of OA are currently unknown. Multiple risk factors are involved ...Osteoarthritis (OA) is a debilitating chronic joint disease affecting large populations of patients, especially the elderly. The pathological mechanisms of OA are currently unknown. Multiple risk factors are involved in OA development. Among these risk factors, alterations of mechanical loading in the joint leading to changes in biological signaling pathways have been known as a key event in OA development. The importance of AMPK-β-catenin-Runx2 signaling in the initiation and progression of OA has been recognized in recent years. In this review, we discuss the recent progress in understanding the role of this signaling pathway and the underlying interaction mechanisms during OA development. We also discuss the drug development aiming to target this signaling pathway for OA treatment.展开更多
基金supported by the National Natural Science Foundation of China(No.81473314)
文摘Peptides from Pilose antler aqueous extract(PAAE) have been shown to stimulate the proliferation and differentiation of bone marrow mesenchymal stem cells(BMSCs). However, the underlying molecular mechanisms are not well understood. Here, PAAE was isolated and purified to explore the molecular mechanisms underlying PAAE’s effects on BMSCs as well as its osteoprotective effects in ovariectomized rats. Our results showed that PAAE promoted proliferation and differentiation of BMSCs to become osteoblasts by enhancing ALP activity and increasing extracellular matrix mineralization. The trabecular microarchitecture of ovariectomized rats was also found to be protected by PAAE. Quantitative reverse transcription-polymerase chain reaction(Quantitative RT-PCR) results suggest that PAAE also increased the expression of osteogenic markers including, alkaline phosphatase(ALP), runt-related transcription factor 2(Runx2), osteocalcin(OCN), bone morphogenetic protein-2(BMP-2), and collagen I(COL-I). Immunoblotting results indicated that PAAE upregulated the levels of BMP-2 and Runx2 and was associated with Smad1/5 phosphorylation. PAAE A at the concentration of 200μg·mL^-1 showed the strongest effect on proliferation and osteogenic differentiation of BMSCs after 48 h. Using matrix-assisted laser desorption/ionization time of flight mass spectrometry(MALDI-TOF MS), we identified the molecular weight of PAAE A and found that it is less than 3000 Da and showed several significant peaks. In conclusion, PAAE activates the BMP-2/Smad1, 5/Runx2 pathway to induce osteoblastic differentiation and mineralization in BMSCs and can inhibit OVX-induced bone loss. These mechanisms are likely responsible for its therapeutic effect on postmenopausal osteoporosis.
基金This study was supported by research grants from the Japan Society for the Promotion of Science,KAKENHI:grant-in-aid for scientific research(C)(grant Nos.15K10486,17K10933,and 18K09111).We thank K.Yuki(the University of Tokyo)for mouse careHui Gao for technical assistance+1 种基金Isozo,Inc.for bone histomorphometry andμ-CT analysesand Bio Matrix Research Inc.for microarray analysis.
文摘Adult bone structural integrity is maintained by remodeling via the coupling of osteoclastic bone resorption and osteoblastic bone formation.Osteocytes or osteoblasts express receptor activator of nuclear factor k-B ligand(Rankl)or osteoprotegerin(Opg)to promote or inhibit osteoclastogenesis,respectively.Bone morphogenetic protein(BMP)is a potent bone inducer,but its major role in adult bone is to induce osteocytes to upregulate sclerostin(Sost)and increase the Rankl/Opg expression ratio,resulting in promotion of osteoclastogenesis.However,the precise effect of BMP-target gene(s)in osteoblasts on the Rankl/Opg expression ratio remains unclear.In the present study,we identified atonal homolog 8(Atoh8),which is directly upregulated by the BMPSmadl axis in osteoblasts.In vivo,Atoh8 was detected in osteoblasts but not osteocytes in adult mice.Although global Atoh8-knockout mice showed only a mild phenotype in the neonate skeleton,the bone volume was decreased and osteoclasts were increased in the adult phase.Atoh8-null marrow stroma cells were more potent than wild-type cells in inducing osteoclastogenesis in marrow cells.Atoh8 loss in osteoblasts increased Runx2 expression and the Rankl/Opg expression ratio,while Runx2 knockdown normalized the Rankl/Opg expression ratio.Moreover,Atoh8 formed a protein complex with Runx2 to inhibit Runx2 transcriptional activity and decrease the Rankl/Opg expression ratio.These results suggest that bone remodeling is regulated elaborately by BMP signaling;while BMP primarily promotes bone resorption,it simultaneously induces Atoh8 to inhibit Runx2 and reduce the Rankl/Opg expression ratio in osteoblasts,suppressing osteoclastogenesis and preventing excessive BMP-mediated bone resorption.
文摘二膦酸盐不仅特异性抑制破骨细胞,同时对成骨细胞也起一定的作用.用酶消化法取乳鼠颅盖骨进行成骨细胞培养,分为空白对照组、阿仑膦酸钠高、中、低剂量组.从BMP-2/Smads/Runx2/Osterix信号通路角度观察二膦酸盐对成骨细胞分化的作用.结果显示:比色法结果显示干预2和4d后各剂量阿仑膦酸钠组的碱性膦酸酶(AKP)显著增加,其中中剂量组表达最高,各组明显高于空白对照组(p<0.05),第6天各剂量阿仑膦酸钠组AKP逐渐下降,与空白对照组比较,无统计学意义(p>0.05);ELISA结果显示随着天数增加各剂量阿仑膦酸钠组的BMP-2逐渐增加,其中中剂量组表达最高,各组明显高于空白对照组(p<0.05),干预2和4d后各剂量阿仑膦酸钠组的I型胶原(Collagen Type I)显著增加,其中中剂量组表达最高,各组明显高于空白对照组(p<0.05),第6天各剂量阿仑膦酸钠组Collagen Type I逐渐下降,空白对照组随着天数逐渐增加,但均低于同时期用药组(p<0.05);荧光定量PCR(qPCR)检测结果显示BMP-2、Smad1/5、Runx2和Osterix mRNA表达在干预后,随着时间的延长,逐渐上升;阿仑膦酸钠组的含量高于同期的空白对照组.提示阿伦膦酸钠能刺激成骨细胞增殖,增强BMP、AKP活性,通过BMP-2/Smads/Runx2/Osterix通路上调相关基因表达,促进成骨细胞分化.
基金supported by National Key Research and Development Program of China(No.2021YFB3800800 to D.C.and L.T)the National Natural Science Foundation of China(No.82030067,82250710174,82161160342,82060406,82360429 and 82172397 to D.C.and L.T.and Y.C.)+2 种基金the Hong Kong RGC(China)(No.HKU-17101821 to W.W.L and D.C.)Shenzhen Science and Technology Program(Guangdong,China)(No.JSGGKQTD20210831174330015 to H.P.and D.C.)Natural Science Foundation of Guangxi(No.2022JJA141126 to Y.C.).
文摘Osteoarthritis (OA) is a debilitating chronic joint disease affecting large populations of patients, especially the elderly. The pathological mechanisms of OA are currently unknown. Multiple risk factors are involved in OA development. Among these risk factors, alterations of mechanical loading in the joint leading to changes in biological signaling pathways have been known as a key event in OA development. The importance of AMPK-β-catenin-Runx2 signaling in the initiation and progression of OA has been recognized in recent years. In this review, we discuss the recent progress in understanding the role of this signaling pathway and the underlying interaction mechanisms during OA development. We also discuss the drug development aiming to target this signaling pathway for OA treatment.
