C3aR和晚期糖基化终产物受体对APP/PS1阿尔兹海默病小鼠模型骨代谢的影响

Effects of C3aR and receptor for advanced glycation end products on bone metabolism in APP/PS1 mice models of Alzheimer′s disease

目的研究补体C3a受体(complement C3a receptor,C3aR)和晚期糖基化终产物受体(receptor for advanced glycation end product,RAGE)对APP/PS1阿尔兹海默病小鼠模型骨代谢的影响。方法将APP/PS1(APPswe/PS1dE9)阿尔兹海默病小鼠分别与C3aR基因敲除鼠(C3aR^(-/-))、RAGE基因敲除鼠(RAGE^(-/-))杂交产生APP/PS1-C3aR^(-/-)和APP/PS1-RAGE^(-/-)。在体内,通过微计算机断层扫描(Micro-CT)、骨组织骨钙素免疫组织化学染色、抗酒石酸酸性磷酸酶(tartrate-resistant acid phosphatase,TRAP)染色和Goldner三色法染色,了解不同基因型鼠之间骨代谢的差异性;在体外,通过骨髓源成骨细胞和破骨细胞诱导培养了解C3aR和RAGE对成骨细胞和破骨细胞分化的影响。结果在体内实验中,与APP/PS1小鼠相比,APP/PS1-C3aR^(-/-)和APP/PS1-RAGE^(-/-)小鼠骨量增多,骨形成增加,骨吸收减弱,类骨质增多(P<0.05)。在体外实验中,APP/PS1-C3aR^(-/-)和APP/PS1-RAGE^(-/-)小鼠骨髓间充质干细胞(BMSCs)成骨分化能力增强,碱性磷酸酶(ALP)、成骨转录因子2(RUNX2)表达增加,破骨细胞分化能力减弱,TRAP染色阳性减少(P<0.05)。结论C3aR和RAGE都参与调节APP/PS1小鼠骨代谢过程,敲除C3aR和RAGE可以改善APP/PS1小鼠的骨质疏松,为临床上阿尔兹海默病合并骨质疏松的治疗提供了新的靶点。

Objective To investigate the effects of complement C3a receptor(C3aR)and receptor for advanced glycation end product(RAGE)on bone metabolism in APP/PS1 mice model of Alzheimer′s disease.Methods Alzheimer′s disease model APP/PS1 mice was hybridized with C3aR knockout mice(C3aR^(-/-)),RAGE knockout mice(RAGE^(-/-))to generate APP/PS1-C3aR^(-/-)and APP/PS1-RAGE^(-/-),respectively.In vivo,micro computed tomography(Micro-CT)scan,bone tissue osteocalcin immunohistochemical staining,tartrate-resistant acid phosphatase(TRAP)staining and Goldner′s trichrome staining were used to understand the variabilities of bone metabolism between different genotypes of mice;In vitro,bone marrow-derived osteoblast and osteoclast induction cultures were used to understand the effects of C3aR and RAGE on osteoblast and osteoclast differentiation.Results In in vivo experiments,APP/PS1-C3aR^(-/-)and APP/PS1-RAGE^(-/-)mice showed increased bone mass,increased bone formation,decreased bone resorption,and increased osteoid compared to APP/PS1 mice(P<0.05).In in vitro experiments,bone marrow mesenchymal stem cells(BMSCs)derived from APP/PS1-C3aR^(-/-)and APP/PS1-RAGE^(-/-)mice showed enhanced osteoblast differentiation and elevated expression levels of alkaline phosphatase(ALP)and runt-related transcription factor 2(RUNX2),diminished osteoclast differentiation,and reduced positive TRAP staining(P<0.05).Conclusions Both C3aR and RAGE are involved in regulating the process of APP/PS1 bone metabolism.Knockout of C3aR and RAGE can improve osteoporosis in APP/PS1,providing a new target for the clinical treatment of Alzheimer′s disease combined with osteoporosis.