Cpne7 deficiency induces cellular senescence and premature aging of dental pulp.

Once tooth development is complete, odontoblasts and their progenitor cells in the dental pulp play a major role in protecting tooth vitality from external stresses. Hence, understanding the homeostasis of the mature pulp populations is just as crucial as understanding that of the young, developing ones for managing age-related dentinal damage. Here, it is shown that loss of Cpne7 accelerates cellular senescence in odontoblasts due to oxidative stress and DNA damage accumulation. Thus, in Cpne7-null dental pulp, odontoblast survival is impaired, and aberrant dentin is extensively formed. Intraperitoneal or topical application of CPNE7-derived functional peptide, however, alleviates the DNA damage accumulation and rescues the pathologic dentin phenotype. Notably, a healthy dentin-pulp complex lined with metabolically active odontoblasts is observed in 23-month-old Cpne7-overexpressing transgenic mice. Furthermore, physiologic dentin was regenerated in artificial dentinal defects of Cpne7-overexpressing transgenic mice. Taken together, Cpne7 is indispensable for the maintenance and homeostasis of odontoblasts, while promoting odontoblastic differentiation of the progenitor cells. This research thereby introduces its potential in oral disease-targeted applications, especially age-related dental diseases involving dentinal loss.

CPNE7 regenerates periodontal ligament via TAU-mediated alignment and cementum attachment protein-mediated attachment.

AIM: Once the periodontal ligament (PDL) is damaged, it is difficult to regenerate its characteristic structure. Copine7 (CPNE7) reportedly plays a functional role in supporting periodontal attachment and PDL alignment. Here we demonstrate the regulatory mechanism of CPNE7 coordination with cytoskeleton reorganization and cementum attachment protein (CAP)-mediated attachment in PDL regeneration. MATERIALS AND METHODS: The expression and localization of CPNE7, α-TUBULIN, ACTIN, and microtubule associated protein tau (TAU) were investigated in vitro. The effects of recombinant CPNE7 (rCPNE7) and CPNE7-derived peptides (CPNE7-DP) on the regulation of CAP were analysed in vitro, and PDL repair capacity was analysed in vivo. RESULTS: CPNE7 co-localized with F-ACTIN and induced α-TUBULIN expansion to the edge of human PDL cells (hPDLCs). ACTIN and α-TUBULIN protein expressions were not elevated in rCPNE7-treated hPDLCs. rCPNE7 elevated the protein expression of TAU, which co-localized with F-ACTIN and α-TUBULIN. Replantation studies on mice revealed that well-attached and well-aligned PDLs were repaired in the rCPNE7 group. CPNE7-DP directly up-regulate the expression of CAP in vitro and promote PDL regeneration in three-wall defect canine models in vivo. CONCLUSIONS: Our findings suggest that CPNE7 helps in PDL repair by supporting PDL alignment through TAU-mediated cytoskeleton reorganization and direct regulation of CAP-mediated PDL attachments of PDLCs.

CPNE7-Induced Autophagy Restores the Physiological Function of Mature Odontoblasts.

Dentin, which composes most of the tooth structure, is formed by odontoblasts, long-lived post-mitotic cells maintained throughout the entire life of the tooth. In mature odontoblasts, however, cellular activity is significantly weakened. Therefore, it is important to augment the cellular activity of mature odontoblasts to regenerate physiological dentin; however, no molecule regulating the cellular activity of mature odontoblasts has yet been identified. Here, we suggest that copine-7 (CPNE7) can reactivate the lost functions of mature odontoblasts by inducing autophagy. CPNE7 was observed to elevate the expression of microtubule-associated protein light chain 3-II (LC3-II), an autophagy marker, and autophagosome formation in the pre-odontoblast and mature odontoblast stages of human dental pulp cells. CPNE7-induced autophagy upregulated DSP and DMP-1, odontoblast differentiation and mineralization markers, and augmented dentin formation in mature odontoblasts. Furthermore, CPNE7 also upregulated NESTIN and TAU, which are expressed in the physiological odontoblast process, and stimulated the elongation of the odontoblast process by inducing autophagy. Moreover, lipofuscin, which progressively accumulates in long-lived post-mitotic cells and hinders their proper functions, was observed to be removed in recombinant CPNE7-treated mature odontoblasts. Thus, CPNE7-induced autophagy reactivated the function of mature odontoblasts and promoted the formation of physiological dentin in vivo. On the other hand, the well-known autophagy inducer, rapamycin, promoted odontoblast differentiation in pre-odontoblasts but did not properly reactivate the function of mature odontoblasts. These findings provide evidence that CPNE7 functionally reactivates mature odontoblasts and introduce its potential for dentinal loss-targeted clinical applications.

Different Responsiveness of Alveolar Bone and Long Bone to Epithelial-Mesenchymal Interaction-Related Factor.

Alveolar bone is both morphologically and functionally different from other bones of the axial or peripheral skeleton. Because of its sensitive nature to external stimuli including mechanical stress, bone loss stimuli, and medication-related osteonecrosis of the jaw, alveolar bone rendering is seen as an important factor in various dental surgical processes. Although multiple studies have validated the response of long bone to various factors, how alveolar bone responds to functional stimuli still needs further clarification. To examine the characteristics of bone in vitro, we isolated cells from alveolar, femur, and tibia bone tissue. Although primary cultured mouse alveolar bone-derived cells (mABDCs) and mouse long bone-derived cells (mLBDCs) exhibited similar osteoblastic characteristics, morphology, and proliferation rates, both showed distinct expression of neural crest (NC) and epithelial-mesenchymal interaction (EMI)-related genes. Furthermore, they showed significantly different mineralization rates. RNA sequencing data demonstrated distinct transcriptome profiles of alveolar bone and long bone. Osteogenic, NC-, and EMI-related genes showed distinct expression between mABDCs and mLBDCs. When the gene expression patterns during osteogenic differentiation were analyzed, excluding several osteogenic genes, NC- and EMI-related genes showed different expression patterns. Among EMI-related proteins, BMP4 elevated the expression levels of osteogenic genes, Msx2, Dlx5, and Bmp2 the most, more noticeably in mABDCs than in mLBDCs during osteogenic differentiation. In in vivo models, the BMP4-treated mABDC group showed massive bone formation and maturation as opposed to its counterpart. Bone sialoprotein expression was also validated in calcified tissues. Overall, our data suggest that alveolar bone and long bone have different responsiveness to EMI by distinct gene regulation. In particular, BMP4 has critical bone formation effects on alveolar bone, but not on long bone. © 2020 The Authors. JBMR Plus published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research.

Dentin sialophosphoprotein expression in enamel is regulated by Copine-7, a preameloblast-derived factor.

OBJECTIVE: Dentin sialophosphoprotein (Dspp) is expressed in odontoblasts and transiently expressed in early ameloblasts. However, the origin of Dspp in ameloblasts remains unclear. Our previous studies demonstrated that copine-7 (CPNE7), a molecule that is secreted by the dental epithelium, is expressed in early ameloblasts and is then translocated to differentiating odontoblasts; its expression levels correlate with odontoblast differentiation under the control of Dspp expression. The objective of this study is to figure out the relationship between CPNE7 and Dspp during amelogenesis. DESIGN: The gene expression patterns of CPNE7 and dentin sialoprotein (DSP) were examined by immunohistochemistry, western blot analysis, and real-time polymerase chain reaction. The effects of CPNE7 on Dspp regulation were investigated using luciferase and chromatin immunoprecipitation assays in ameloblastic HAT-7 cells. RESULTS: The gene expression pattern of Cpne7 was similar to that of Dspp during ameloblast differentiation. Moreover, Gene expression omnibus profiles indicated that there is a close correlation between Cpne7 and Dspp expression in various normal human tissues. We also confirmed the effects of CPNE7 on the induction of Dspp in ameloblastic HAT-7 cells. Cpne7 overexpression promoted Dspp expression, whereas Dspp expression was down-regulated by Cpne7 inactivation. CONCLUSIONS: These results suggest that the expression of Dspp in early amelogenesis is linked to CPNE7, a preameloblast-derived factor.

Sonographic and MR imaging findings of testicular epidermoid cysts.

OBJECTIVE: The purpose of this study is to analyze the sonographic and MR imaging findings of testicular epidermoid cysts. CONCLUSION: Sonographic findings of a markedly heterogeneous intratesticular mass with or without alternating hypo- and hyperechoic layers surrounded by a hypoechoic or echogenic rim and the absence of flow on color Doppler sonography suggest the preoperative diagnosis of testicular epidermoid cysts. T2-weighted MR imaging findings of a high-signal-intensity mass with or without low-signal-intensity foci surrounded by a low-signal-intensity rim and the absence of enhancement on contrast-enhanced T1-weighted MR images can strengthen the preoperative diagnosis. These imaging findings can offer a basis for surgeons to attempt testis-sparing surgery instead of orchiectomy.

Tumor-associated proteins in rat submandibular gland induced by DMBA and irradiation / 대한구강악안면방사선학회지

This study was performed in order to identify changes of the plasma membrane proteins in rat submandibular gland tumors induced by 7,12-dimethylbenz[a]anthracene [DMBA] and X-irradiation. Two kinds of tumor associated membrane proteins (protein A and B) were isolated with 3 M KCl extraction from rat submandibular gland tumors induced by DMBA and X-irradiation. To identify their antigenicities, immunoelectrophoresis and double immunodiffusion was carried out with various proteins extracted from liver, heart, skin and pancreas of adult rats and from embryonic liver, heart and skin. The rabbit antisera against the protein A did not cross-react with any of the proteins extracted from the above mentioned tissues, suggesting that protein A might be tumor specific antigen. However, the rabbit antisera against protein B was precipitated with proteins extracted from the liver of adult and embryonic rats. Polyacrylamide gel electrophoresis of these two proteins (A and B) showed that protein A was a dimer with molecular weights of 69,000 and 35,000 dalton, whereas protein B was a monomer with molecular weight of 50,000 dalton.