Targeted reversion of induced pluripotent stem cells from patients with human cleidocranial dysplasia improves bone regeneration in a rat calvarial bone defect model

BackgroundRunt-related transcription factor 2 (RUNX2) haploinsufficiency causes cleidocranial dysplasia (CCD) which is characterized by supernumerary teeth, short stature, clavicular dysplasia, and osteoporosis. At present, as a therapeutic strategy for osteoporosis, mesenchymal stem cell (MSC) transplantation therapy is performed in addition to drug therapy. However, MSC-based therapy for osteoporosis in CCD patients is difficult due to a reduction in the ability of MSCs to differentiate into osteoblasts resulting from impaired RUNX2 function. Here, we investigated whether induced pluripotent stem cells (iPSCs) properly differentiate into osteoblasts after repairing the RUNX2 mutation in iPSCs derived from CCD patients to establish normal iPSCs, and whether engraftment of osteoblasts derived from properly reverted iPSCs results in better regeneration in immunodeficient rat calvarial bone defect models.MethodsTwo cases of CCD patient-derived induced pluripotent stem cells (CCD-iPSCs) were generated using retroviral vectors (OCT3/4, SOX2, KLF4, and c-MYC) or a Sendai virus SeVdp vector (KOSM302L). Reverted iPSCs were established using programmable nucleases, clustered regularly interspaced short palindromic repeats (CRISPR)/Cas-derived RNA-guided endonucleases, to correct mutations in CCD-iPSCs. The mRNA expressions of osteoblast-specific markers were analyzed using quantitative reverse-transcriptase polymerase chain reaction. iPSCs-derived osteoblasts were transplanted into rat calvarial bone defects, and bone regeneration was evaluated using microcomputed tomography analysis and histological analysis.ResultsMutation analysis showed that both contained nonsense mutations: one at the very beginning of exon 1 and the other at the initial position of the nuclear matrix-targeting signal. The osteoblasts derived from CCD-iPSCs (CCD-OBs) expressed low levels of several osteoblast differentiation markers, and transplantation of these osteoblasts into calvarial bone defects created in rats with severe combined immunodeficiency showed poor regeneration. However, reverted iPSCs improved the abnormal osteoblast differentiation which resulted in much better engraftment into the rat calvarial bone defect.ConclusionsTaken together, these results demonstrate that patient-specific iPSC technology can not only provide a useful disease model to elucidate the role of RUNX2 in osteoblastic differentiation but also raises the tantalizing prospect that reverted iPSCs might provide a practical medical treatment for CCD

不正咬合者における下顎頭形態と咬合関係および顎顔面形態の相互関連性

本研究は,下顎頭形態と咬合関係および顎顔面形態の関連性を検討することを目的として行った.281名の女性不正咬合患者を対象とし,顎関節断層X線写真,側面頭部X線規格写真および口腔内模型を資料とした.下顎頭の形態を4つの型に分類し,臼歯部の咬合関係をAngle分類に準じ3つの型に分類した.また10項目の計測項目より顎顔面形態を評価した.それらのデータより,下顎頭形態と咬合関係,下顎頭形態と顎顔面形態との関連を検討した結果,以下の結論を得た.1.下顎頭形態1型が全ての咬合関係において最も多く認められ,特にAngle III級において多く認められた.下顎頭形態2型はAngle III級において少なく,下顎頭形態3型はAngle III級においてII級に比べ多く認められた.下顎頭形態4型はいずれの咬合関係においても少なかった.2.Angle I級においては,下顎頭形態2型,3型が前歯部被蓋の浅い顎顔面形態を示した.また下顎頭形態4型では下顎の前上方回転が軽度に認められた.Angle II級においては,下顎頭形態2型および3型が下顎の後方位,後下方回転という顎顔面形態を示していた.Angle III級においては,下顎頭形態2型のみが前歯部の被蓋が正被蓋であった.3.AICによる分析の結果,下顎頭形態と最も関連の深い計測項目はramus inclinationであったことから,下顎枝の傾斜と下顎頭形態との間に最も関連があることが推定された.また下顎骨の水平的関係が垂直的関係よりも,相対的に下顎頭形態に関連していることも推定された.This study was conducted in order to investigate correlations between mandibular condyle morphology with occlusion and maxillofacial morphology. A total of 281 female were subjected to the study, and tomograms of their temporomandibular joints (TMJ), lateral cephalograms and intraoral models were studied. Mandibular condyle morphology was classified into 4 types, and molar occlusions were classified into 3 types based on Angle's classification. In addition, maxillofacial morphology was assessed by measuring 10 items. Based on these data, correlations between mandibular condyle morphology and occlusion, and correlations between mandibular condyle morphology and maxillofacial morphology were investigated, and the following conclusions were reached. 1. Type 1 mandibular condyle morphology was observed most frequently throughout all occlusions, especially in the Angle class III. Type 2 was seen less frequently in the Angle class III, and type 3 was seen more frequently in the Angle class III than in the Angle class II. Type 4 was not observed very often throughout the occlusions. 2. In the Angle class I, type 2 and 3 mandibular condyle morphology presented maxillofacial morphology featuring small incisor overbites. In addition, a slight antero-superior rotation of the mandible was observed in type 4. In the Angle class II, type 2 and 3 presented posterior or postero-inferior rotations of the mandible. In the Angle class III, positive incisor overlap was seen only with type 2. 3. According to AIC analysis, the measurement item which was associated the most with mandibular condyle morphology was ramus inclination, suggesting that the most significant correlation was between the mandibular ramus inclination and the mandibular condyle morphology. Moreover, the horizontal relationship of mandible was assumed to be relatively more associated with mandibular condyle morphology than with vertical relationship

不正咬合者における下顎頭形態と咬合関係および顎顔面形態の相互関連性

本研究は,下顎頭形態と咬合関係および顎顔面形態の関連性を検討することを目的として行った.281名の女性不正咬合患者を対象とし,顎関節断層X線写真,側面頭部X線規格写真および口腔内模型を資料とした.下顎頭の形態を4つの型に分類し,臼歯部の咬合関係をAngle分類に準じ3つの型に分類した.また10項目の計測項目より顎顔面形態を評価した.それらのデータより,下顎頭形態と咬合関係,下顎頭形態と顎顔面形態との関連を検討した結果,以下の結論を得た.1.下顎頭形態1型が全ての咬合関係において最も多く認められ,特にAngle III級において多く認められた.下顎頭形態2型はAngle III級において少なく,下顎頭形態3型はAngle III級においてII級に比べ多く認められた.下顎頭形態4型はいずれの咬合関係においても少なかった.2.Angle I級においては,下顎頭形態2型,3型が前歯部被蓋の浅い顎顔面形態を示した.また下顎頭形態4型では下顎の前上方回転が軽度に認められた.Angle II級においては,下顎頭形態2型および3型が下顎の後方位,後下方回転という顎顔面形態を示していた.Angle III級においては,下顎頭形態2型のみが前歯部の被蓋が正被蓋であった.3.AICによる分析の結果,下顎頭形態と最も関連の深い計測項目はramus inclinationであったことから,下顎枝の傾斜と下顎頭形態との間に最も関連があることが推定された.また下顎骨の水平的関係が垂直的関係よりも,相対的に下顎頭形態に関連していることも推定された.This study was conducted in order to investigate correlations between mandibular condyle morphology with occlusion and maxillofacial morphology. A total of 281 female were subjected to the study, and tomograms of their temporomandibular joints (TMJ), lateral cephalograms and intraoral models were studied. Mandibular condyle morphology was classified into 4 types, and molar occlusions were classified into 3 types based on Angle\u27s classification. In addition, maxillofacial morphology was assessed by measuring 10 items. Based on these data, correlations between mandibular condyle morphology and occlusion, and correlations between mandibular condyle morphology and maxillofacial morphology were investigated, and the following conclusions were reached. 1. Type 1 mandibular condyle morphology was observed most frequently throughout all occlusions, especially in the Angle class III. Type 2 was seen less frequently in the Angle class III, and type 3 was seen more frequently in the Angle class III than in the Angle class II. Type 4 was not observed very often throughout the occlusions. 2. In the Angle class I, type 2 and 3 mandibular condyle morphology presented maxillofacial morphology featuring small incisor overbites. In addition, a slight antero-superior rotation of the mandible was observed in type 4. In the Angle class II, type 2 and 3 presented posterior or postero-inferior rotations of the mandible. In the Angle class III, positive incisor overlap was seen only with type 2. 3. According to AIC analysis, the measurement item which was associated the most with mandibular condyle morphology was ramus inclination, suggesting that the most significant correlation was between the mandibular ramus inclination and the mandibular condyle morphology. Moreover, the horizontal relationship of mandible was assumed to be relatively more associated with mandibular condyle morphology than with vertical relationship