Ou Yanjing, Zhou Yi, Liang Shanshan, Wang Yining
The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) and Key Laboratory of Oral Biomedicine Ministry of Education, School and Hospital of Stomatology, Wuhan University, Wuhan, China.
PeerJ. 2018 Oct 17;6:e5808. doi: 10.7717/peerj.5808. eCollection 2018.
Senescence-related impairment of proliferation and differentiation limits the use of dental pulp cells for tissue regeneration. Deletion of sclerostin improves the dentinogenesis regeneration, while its role in dental pulp senescence is unclear. We investigated the role of sclerostin in subculture-induced senescence of human dental pulp cells (HDPCs) and in the senescence-related decline of proliferation and odontoblastic differentiation.
Immunohistochemical staining and qRT-PCR analyses were performed to examine the expression pattern of sclerostin in young (20-30-year-old) and senescent (45-80-year-old) dental pulps. HDPCs were serially subcultured until senescence, and the expression of sclerostin was examined by qRT-PCR analysis. HDPCs with sclerostin overexpression and knockdown were constructed to investigate the role of sclerostin in HDPCs senescence and senescence-related impairment of odontoblastic differentiation potential.
By immunohistochemistry and qRT-PCR, we found a significantly increased expression level of sclerostin in senescent human dental pulp compared with that of young human dental pulp. Additionally, elevated sclerostin expression was found in subculture-induced senescent HDPCs in vitro. By sclerostin overexpression and knockdown, we found that sclerostin promoted HDPCs senescence-related decline of proliferation and odontoblastic differentiation potential with increased expression of p16, p53 and p21 and downregulation of the Wnt signaling pathway.
The increased expression of sclerostin is responsible for the decline of proliferation and odontoblastic differentiation potential of HDPCs during cellular senescence. Anti-sclerostin treatment may be beneficial for the maintenance of the proliferation and odontoblastic differentiation potentials of HDPCs.
衰老相关的增殖和分化受损限制了牙髓细胞在组织再生中的应用。硬骨素的缺失可改善牙本质生成再生，但其在牙髓衰老中的作用尚不清楚。我们研究了硬骨素在人牙髓细胞（HDPCs）传代培养诱导的衰老以及衰老相关的增殖和牙本质细胞分化下降中的作用。
采用免疫组织化学染色和qRT-PCR分析检测硬骨素在年轻（20 - 30岁）和衰老（45 - 80岁）牙髓中的表达模式。HDPCs连续传代培养直至衰老，通过qRT-PCR分析检测硬骨素的表达。构建硬骨素过表达和敲低的HDPCs，以研究硬骨素在HDPCs衰老和衰老相关的牙本质细胞分化潜能受损中的作用。
通过免疫组织化学和qRT-PCR，我们发现衰老的人牙髓中硬骨素的表达水平明显高于年轻的人牙髓。此外，在体外传代培养诱导的衰老HDPCs中也发现硬骨素表达升高。通过硬骨素过表达和敲低，我们发现硬骨素通过增加p16、p53和p21的表达以及下调Wnt信号通路，促进了HDPCs衰老相关的增殖和牙本质细胞分化潜能的下降。
硬骨素表达增加是HDPCs在细胞衰老过程中增殖和牙本质细胞分化潜能下降的原因。抗硬骨素治疗可能有利于维持HDPCs的增殖和牙本质细胞分化潜能。
