Department of Orthodontics, School of Stomatology, Tongji University, Shanghai Engineering Research Center of Tooth Restoration and Regeneration, 399 Middle Yanchang Road, Shanghai, 200072, China.
Department of Orthodontics, School of Stomatology, Tongji University, Shanghai Engineering Research Center of Tooth Restoration and Regeneration, 399 Middle Yanchang Road, Shanghai, 200072, China.
Arch Oral Biol. 2020 Sep;117:104821. doi: 10.1016/j.archoralbio.2020.104821. Epub 2020 Jun 17.
To investigate the effects of endogenous hydrogen sulfide (HS) synthase, cystathionine-γ-lyase (CSE), on the healing of mandibular defect and the osteogenic differentiation of human mandibular bone marrow mesenchymal stem cells (HM-BMMSCs).
Sixty 8-week male C57BL/6 wild-type (WT) mice and CSE knockout (CSE) mice were divided into WT group, CSE group and CSE + GYY4137 (a slow-releasing HS donor) group. Mandibular defect healing in each group was identified by micro-CT. The histological staining and immunohistochemical staining were adopted to evaluate bone regeneration and reconstruction of mandibular defect. HM-BMMSCs were extracted and cultured for osteogenic induction, which were divided into control group, PAG (a CSE inhibitor) group, GYY4137 group and PAG + GYY4137 group. The mineralization of HM-BMMSCs in each group was determined by alkaline phosphatase (ALP) staining and alizarin red staining. Moreover, mRNA expressions of ALP and Runt-related transcription factor 2 (RUNX2) were detected by RT-PCR.
Mandibular defect healing in CSE mice was undesirable. When exogenous HS were supplemented to CSE mice, the new bone mass increased with higher degrees of bone mineralization and bone maturity. Bone mineral density (BMD), bone volume fraction (BV/TV) and bone trabecular thickness (Tb.Th) also significantly increased. in vitro experiments showed that PAG attenuated ALP activity and mineralized nodule formation ability in HM-BMMSCs, and repressed mRNA expressions of ALP and RUNX2. All these osteogenic indexes of HM-BMMSCs were reversed after exogenous HS was supplemented.
It is demonstrated that CSE deficiency thwarts the healing of mandibular defect. Blocking the synthesis of HS inhibits the osteogenic differentiation of HM-BMMSCs, thereby affects bone healing.
探讨内源性硫化氢（HS）合酶胱硫醚-γ-裂解酶（CSE）对下颌骨缺损愈合和人下颌骨髓间充质干细胞（HM-BMMSCs）成骨分化的影响。
将 60 只 8 周龄雄性 C57BL/6 野生型（WT）小鼠和 CSE 敲除（CSE）小鼠分为 WT 组、CSE 组和 CSE+GYY4137（一种缓慢释放 HS 供体）组。通过 micro-CT 鉴定各组下颌骨缺损愈合情况。采用组织学染色和免疫组织化学染色评价下颌骨缺损的骨再生和重建。提取并培养 HM-BMMSCs 进行成骨诱导，分为对照组、PAG（CSE 抑制剂）组、GYY4137 组和 PAG+GYY4137 组。通过碱性磷酸酶（ALP）染色和茜素红染色测定各组 HM-BMMSCs 的矿化情况。此外，通过 RT-PCR 检测 ALP 和 runt 相关转录因子 2（RUNX2）的 mRNA 表达。
CSE 小鼠的下颌骨缺损愈合不良。当补充外源性 HS 时，CSE 小鼠的新生骨量增加，骨矿化和骨成熟程度更高。骨密度（BMD）、骨体积分数（BV/TV）和骨小梁厚度（Tb.Th）也显著增加。体外实验表明，PAG 减弱了 HM-BMMSCs 的 ALP 活性和矿化结节形成能力，并抑制了 ALP 和 RUNX2 的 mRNA 表达。补充外源性 HS 后，所有这些 HM-BMMSCs 的成骨指标均得到逆转。
CSE 缺乏会阻碍下颌骨缺损的愈合。阻断 HS 的合成抑制了 HM-BMMSCs 的成骨分化，从而影响骨愈合。
