Long-term dental intervention and laboratory examination in a patient with Vitamin D-dependent rickets type I: A case report.

RATIONALE: Vitamin D-dependent rickets type I (VDDR-I) is a rare form of rickets, which is an autosomal recessive disease caused by 1α-hydroxylase enzyme deficiency. However, long-term dental management and microscopic morphology of teeth remain largely unclear. PATIENT CONCERNS: We report the case of a 10-year-old Chinese boy complaining of yellowish-brown teeth with extensive caries. DIAGNOSES: Clinical and laboratory examinations were performed, and VDDR-I was confirmed. Scanning electron microscopy confirmed amelogenesis imperfecta. INTERVENTIONS: The patient had been taking drugs intervention for VDDR-I from the age of 3 years. The decayed teeth were treated, and metal-preformed crowns were placed to prevent further impairment. Sequence tooth extraction and remineralization therapy were also performed. OUTCOMES: After 3 years of follow-up, the patient exhibited normal tooth replacement and an acceptable oral hygiene status. However, the new erupted teeth had amelogenesis imperfecta. LESSONS: This case is the first to confirm amelogenesis imperfecta in a patient with VDDR-I that was not prevented by drug intervention. Importantly, it provides evidence that long-term dental intervention in patients with VDDR-I can result in an acceptable oral hygiene status. Therefore, early and long-term dental intervention is necessary in VDDR-I patients.

[Mechano-growth factor regulated cyclic stretch-induced osteogenic differentiation and MMP-1, MMP-2 expression in human periodontal ligament cells by activating the MEK/ERK1/2 pathway].

PURPOSE: To explore the role and mechanism of mechano-growth factor (MGF) in cyclic stretch (CS)-induced osteogenic differentiation and MMP-1, MMP-2 expression in human periodontal ligament cells (hPDLCs). METHODS: HPDLCs were isolated and transfected with si-MGF, or stimulated with MGF or MEK/ERK pathway inhibitor U0126. Cells were cultured in Flexercell system with 10% elongation at 0.1 Hz. An alkaline phosphatase (ALP) kit was used to detect ALP activity. QRT-PCR assay was performed to determine the transcript levels of MGF and osteogenic genes, including ALP, runt-related transcription factor 2 (Runx2) and osteopontin (OPN). Western bot was used to evaluate the effect on MEK/EKR1/2 signaling. Statistical analysis was performed using SPSS 19.0 software package. RESULTS: CS induced the expression of MGF in hPDLCs in a time-dependent manner (P＜0.05). In contrast to the control group, transfection with si-MGF inhibited the expression of MGF in hPDLCs (P＜0.05). Moreover, cessation of MGF dramatically suppressed ALP activity (P＜0.05) and the expression of osteogenic gene ALP, Runx2 and OPN (P＜0.05) in hPDLCs. Furthermore, down-regulation of MGF restrained the expression of MMP-1 and MMP-2, in contrast to CS group (P＜0.05). Conversely, stimulation with MGF further enhanced the effects of CS on osteogenic differentiation of hPDLCs and MMP-1, MMP-2 expression (P＜0.05). Additionally, MGC silencing abrogated CS-induced expression of p-ERK (P＜0.05), which was further enhanced following MGF treatment (P＜0.05). Simultaneously, precondition with U0126 antagonized MGF-enhanced effects on CS-triggered osteogenic differentiation and MMP-1, MMP-2 expression (P＜0.05). CONCLUSIONS: Mechano-growth factor regulates cyclic stretch-induced osteogenic differentiation and MMP-1, MMP-2 expression in human periodontal ligament cells by activating MEK/ERK1/2 signaling pathway.

Necrostatin-1 promotes ectopic periodontal tissue like structure regeneration in LPS-treated PDLSCs.

Necroptosis is a programmed necrosis, regulated by receptor interacting protein kinase 1(RIP1) and receptor interacting protein kinase 3(RIP3), and could be inhibited by necrostatin-1(Nec-1) specifically. This study aims to evaluate the effect of Nec-1 on LPS-treated periodontal ligament stem cells (PDLSCs). In the research, three groups were established: normal cultured PDLSCs, Porphyromonas gingivalis (Pg)-LPS stimulated PDLSCs and Pg-LPS+Nec-1 treated PDLSCs. The expression of RIP1 and RIP3 and osteogenic differentiation of PDLSCs in three groups were analyzed. Then, we constructed cell aggregates (CA) using PDLSCs, then PDLSCs-CA were combined with Bio-Oss in three groups were transplanted subcutaneously in nude mice to assess their potentials of periodontal tissue regeneration. The results showed that RIP1 and RIP3 were fully expressed in Pg-LPS stimulated PDLSCs and the level increased significantly. Nec-1 inhibited RIP1-RIP3 interaction, and further inhibited necroptosis of PDLSCs in inflammatory state. Moreover, Nec-1 pretreatment ameliorates the osteogenic differentiation of LPS-treated PDLSCs and can effectively promote the cementum like structure ectopic regenerative ability of PDLSCs in nude mice. These findings show RIP1/RIP3-mediated necroptosis is an important mechanism of cell death in PDLSCs. Nec-1 has a protective effect in reducing cell death and promotes ectopic periodontal tissue like structure regeneration by inhibiting necroptosis. Nec-1 is a hopeful therapeutic agent which protects cells from necroptosis and ameliorates functional outcome.

Receptor-Interacting Protein 3/Caspase-8 May Regulate Inflammatory Response and Promote Tissue Regeneration in the Periodontal Microenvironment.

BACKGROUND Periodontal ligament stem cells (PDLSCs) possess characteristics of multi-potential differentiation and immuno-modulation, and PDLSCs-mediated periodontal tissue regeneration is regarded as a hopeful method for periodontitis treatment. Recent studies demonstrated that RIP3 and caspase8 regulate bacteria-induced innate immune response and programmed necrosis, which is also called necroptosis. This study aimed to determine the role of the RIP3/Caspase8 signal pathway on necroptosis of PDLSCs under the inflammatory microenvironment, both [i]in vitro[/i] and [i]in vivo[/i]. MATERIAL AND METHODS PDLSCs were cultured, and transmission electron microscopy and flow cytometry were used to detect necroptosis. PCR, ALP, and Alizarin Red S staining were used to assess the effect of necroptosis on osteogenesis differentiation of PDLSCs [i]in vitro[/i], while HE and Masson staining were taken after the nude mouse subcutaneous transplant experiment. RESULTS Our research indicates that RIP3/caspase8 can regulate the immune response of PDLSCs, and blockade of RIP3/caspase8 can protect the biological characteristics of the PDLSCs, effectively promoting periodontal tissue regeneration in the inflammatory microenvironment. CONCLUSIONS Inhibiting RIP3/caspase8 can effectively promote periodontal tissue regeneration in the inflammatory microenvironment.

Response of mandibular condyles of juvenile and adult rats to abnormal occlusion and subsequent exemption.

OBJECTIVE: The adaptation capacities of the mandibular condyle in response to mechanical stimuli might be different between juveniles and adults, but has not been compared. This study aimed to investigate whether abnormal molar occlusion and subsequent molar extraction could lead to different remodeling responses in the mandibular condyles of juvenile and adult rats. METHODS: Abnormal molar occlusion (AMO) was established in the 5- and 16-wk old rats by moving their maxillary left and mandibular right third molars distally. AMO was removed in the molar extraction group at 4 weeks but remained in the AMO group. All rats were sacrificed at 8 weeks. Micro-computed tomography, histomorphology, immunohistochemistry and real-time PCR were adopted to evaluate the remodeling of condylar subchondral bone. RESULTS: Condylar subchondral bone loss and increased osteoclastic activities were observed in both juvenile and adult AMO groups, while increased osteoblastic activities were only seen in the juvenile AMO group. Decreased bone mineral density, bone volume fraction and trabecular thickness, but increased trabecular separation, number and surface of osteoclasts and mRNA levels of TRAP, cathepsin-K, RANKL in the juvenile AMO group were all reversed after molar extraction (all P<0.05). However, these parameters showed no difference between adult AMO and extraction groups (all P>0.05). CONCLUSIONS: Abnormal molar occlusion led to degenerative remodeling in the mandibular condyles of both juvenile and adult rats, while exemption of abnormal occlusion caused significant rescue of the degenerative changes only in the juvenile rats.

Clinical, pathological, and genetic evaluations of Chinese patient with otodental syndrome and multiple complex odontoma: Case report.

Otodental syndrome is a rare autosomal-dominant disease characterized by globodontia, associated with sensorineural, high-frequency hearing loss. Here, we describe the clinical, pathological, and genetic evaluations of a 9-year-old girl with otodental syndrome and multiple complex odontoma.The patient presented with a draining sinus tract in her left cheek, globodontia, and hearing loss. The odontomas which caused the cutaneous sinus tracts were extracted because of the odontogenic infection. The extracted odontoma and primary tooth was studied by micro-CT and further observed histopathologically. The micro-CT findings revealed that the primary tooth had three crowns with two separated pulp chambers, and their root canals were partially fused. The histological findings showed abnormal morphologies of odontoblasts and dentin, hyperplasia of enamel, and malformation of odontogenic epithelium. Furthermore, DNA sequencing and analyze of deafness associated gene GJB2, GJB3, and PDS had not revealed any SNP or mutation; but exon 3 of the causative gene FGF3 could not be amplified, which may be associated with the microdeletion at chromosome 11q13.3. Three month after surgery, the patient was found to be asymptomatic and even the evidence of the extra-oral sinus had disappeared.The dental abnormality of otodental syndrome included congenital missing teeth, globodontia, and multiple complex odontoma. Globodontia exhibited characteristic features of fusion teeth. In addition, gene FGF3 haploinsufficiency was likely to be the cause of otodental syndrome. The report provides some new information in the field of otodental syndrome, which would make dentists more familiar with this disease.

Betulinic Acid Inhibits Cell Proliferation in Human Oral Squamous Cell Carcinoma via Modulating ROS-Regulated p53 Signaling.

Oral squamous cell carcinoma (OSCC) is a common cancer of the head and neck. Betulinic acid (BA) is a naturally occurring pentacyclic triterpenoid. The present study was designed to explore the effects of BA on OSCC KB cell proliferation in vitro and on implanted tumor growth in vivo and to examine the possible molecular mechanisms. The results showed that BA dose-dependently inhibited KB cell proliferation and decreased implanted tumor volume. In addition, BA significantly promoted mitochondrial apoptosis, as reflected by an increase in TUNEL+ cells and the activities of caspases 3 and 9, an increase in Bax expression, and a decrease in Bcl-2 expression and the mitochondrial oxygen consumption rate. BA significantly increased cell population in the G0/G1 phase and decreases the S phase cell number, indicating the occurrence of G0/G1 cell cycle arrest. ROS generation was significantly increased by BA, and antioxidant NAC treatment markedly inhibited the effect of BA on apoptosis, cell cycle arrest, and proliferation. BA dose-dependently increased p53 expression in KB cells and implanted tumors. p53 reporter gene activity and p53 binding in the promoters of Bax were significantly increased by BA. Knockdown of p53 blocked BA-induced increase in apoptosis, cell cycle arrest, and inhibition of cell proliferation. NAC treatment suppressed BA-induced increase in p53 expression. Furthermore, phosphorylation of signal transducer and activator of transcription 3 (STAT3) was increased by BA. Taken together, the data demonstrated that ROS-p53 signaling was crucial for BA-exhibited antitumor effect in OSCC. BA may serve as a potential drug for the treatment of oral cancer.

MicroRNA-27a-3p regulates epithelial to mesenchymal transition via targeting YAP1 in oral squamous cell carcinoma cells.

MicroRNAs (miRNAs) are small non-coding RNAs frequently dysregulated in human malignancies. Here, we profiled isolated cells from freshly resected tumors from oral squamous cell carcinoma (OSCC) patients and OSCC cell lines using a SYBR Green-based qPCR miRNA array to identify the expression change of the miRNAs. Based on the microarray data and clincopathological factor analysis of 50 OSCC patients related to these miRNAs, miR-27a-3p was selected as a putative miRNA which might play important role in OSCC progression. By bioinformatics analysis and dual-luciferase reporter assay, we found that YAP1 (Yes-associated protein-1) was a direct target gene of miR-27a-3p. Intriguingly, increased expression of miR-27a-3p could significantly decrease the expression level of YAP1 as well as several epithelial to mesenchymal transition (EMT)-related molecules in OSCC cell lines, including Twist and Snail. Then, follow-up studies revealed that miR-27a-3p expression was able to downregulate the EMT-related molecules effectively, which might be involved in the regulation of Sox2 via the YAP1-OCT4-Sox2 signaling axis. In summary, this study found that miR-27a-3p could inhibit the YAP1 directly by post-transcriptionally silencing and potentially suppress EMT process, suggesting that miR­27a-3p might play pivotal roles in effectively manipulating the invasion and metastasis in oral squamous cell carcinoma cells through the EMT inhibition.

Exposure to a continuous low dose of tetrachlorodibenzo-p-dioxin impairs the development of the tooth root in lactational rats and alters the function of apical papilla-derived stem cells.

OBJECTIVES: Ubiquitous environmental pollutants such as 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) cause abnormalities in reproduction and development. TCDD inhibits the development of teeth, and its effects depend on its dose and the developmental stage of the tooth. Our aim here was to investigate the effect of lower doses of TCDD on the development of the tooth root in vivo and in vitro. DESIGN: We observed tooth root development in lactational rats exposed to continuous low doses of TCDD starting on postnatal day 6 using Mico-CT analyses and histopathological examinations. And then the characteristics of stem cells derived from the apical papilla (SCAPs) were evaluated and compared with SCAPs induced by lower doses of TCDD both in vitro and in vivo. RESULTS: The results of experiments showed that rat pups exposed to low dose TCDD at prenatal stage developed, dentine hypoplasia, and hypomineralization. Further, TCDD impaired the functions of SCAPs in vivo by inhibiting cell proliferation and osteogenic and odontogenic differentiation. The impairment of SCAPs after TCDD exposure was accompanied by increased expression of AHR, down-regulation of the expression of Runx2, and alkaline phosphatase, suggesting that the AHR pathway mediated the effects of TCDD. CONCLUSION: These results provide the first insights into the toxicity of TCDD, which adversely affects the development of the tooth root through indirectly altering the function of SCAPs.

Lipopolysaccharide enhances Wnt5a expression through toll-like receptor 4, myeloid differentiating factor 88, phosphatidylinositol 3-OH kinase/AKT and nuclear factor kappa B pathways in human dental pulp stem cells.

INTRODUCTION: Lipopolysaccharide (LPS) has been implicated in mesenchymal stem cell differentiation processes. Wnt5a, one of the "non-canonical" Wnt family members, is important in signaling stem cell differentiation and in the inflammatory responses of immune cells. Here we studied whether LPS can regulate the expression of Wnt5a in human dental pulp stem cells (hDPSCs) and investigated the intracellular signaling pathways activated by LPS. METHODS: Wnt5a mRNA and protein expression changes in hDPSCs were investigated by real-time polymerase chain reaction analysis and enzyme-linked immunosorbent assay. In addition, real-time polymerase chain reaction, enzyme-linked immunosorbent assay, and luciferase activity assays were used to determine whether toll-like receptor 4 (TLR4), myeloid differentiating factor 88 (MyD88), nuclear factor kappa B (NF-kB), or the phosphatidylinositol 3-OH kinase (PI3K)/AKT pathways are involved in LPS-induced Wnt5a expression. The activation of PI3K and AKT in hDPSCs was measured by Western blot analysis. RESULTS: Wnt5a mRNA and protein expression was rapidly increased in response to LPS in a time- and dose-dependent manner. LPS-induced Wnt5a expression was effectively attenuated by administration of a TLR4 neutralizing antibody, MyD88 inhibitory peptide, PI3-kinase inhibitors (LY294002 and wortmannin), an AKT inhibitor, or NF-κB inhibitor (pyrrolidine dithiocarbamate), IκBa phosphorylation inhibitor (Bay 117082), or IκB protease inhibitor (L-1-tosylamido-2-phenylethyl chloromethyl ketone). Treatment of hDPSCs with LPS activated PI3-kinase (p85) and AKT signaling in a time-dependent manner. Moreover, LPS-mediated increases in κB-luciferase activity were diminished by the overexpression of dominant negative mutants of TLR4, MyD88, p85, AKT, and IκBa. CONCLUSIONS: These results demonstrated that LPS-induced Wnt5a expression was mediated through the TLR4/MyD88/PI3-kinase/AKT pathway, which then initiated NF-κB activation in hDPSCs.

Oral and craniofacial manifestations and two novel missense mutations of the NTRK1 gene identified in the patient with congenital insensitivity to pain with anhidrosis.

Congenital insensitivity to pain with anhidrosis (CIPA) is a rare inherited disorder of the peripheral nervous system resulting from mutations in neurotrophic tyrosine kinase receptor 1 gene (NTRK1), which encodes the high-affinity nerve growth factor receptor TRKA. Here, we investigated the oral and craniofacial manifestations of a Chinese patient affected by autosomal-recessive CIPA and identified compound heterozygosity in the NTRK1 gene. The affected boy has multisystemic disorder with lack of reaction to pain stimuli accompanied by self-mutilation behavior, the inability to sweat leading to defective thermoregulation, and mental retardation. Oral and craniofacial manifestations included a large number of missing teeth, nasal malformation, submucous cleft palate, severe soft tissue injuries, dental caries and malocclusion. Histopathological evaluation of the skin sample revealed severe peripheral nerve fiber loss as well as mild loss and absent innervation of sweat glands. Ultrastructural and morphometric studies of a shed tooth revealed dental abnormalities, including hypomineralization, dentin hypoplasia, cementogenesis defects and a dysplastic periodontal ligament. Genetic analysis revealed a compound heterozygosity--c.1561T>C and c.2057G>A in the NTRK1 gene. This report extends the spectrum of NTRK1 mutations observed in patients diagnosed with CIPA and provides additional insight for clinical and molecular diagnosis.

Comprehensive and sequential management of an impacted maxillary central incisor with severe crown-root dilacerations.

Tooth dilaceration refers to a dental anomaly characterized by an abrupt deviation in the longitudinal axis of tooth. Crown-root dilaceration is diagnosed in teeth with sharp angles at the cement-enamel junction. The greater the bending degree is, the less chance there is for successful teeth preservation and relocation. In this report, a clinical case of an impacted maxillary central incisor with severe crown-root dilacerations was described by means of an operative evaluation using three-dimensional dental computed tomography and a multidisciplinary approach that included surgical, orthodontic, endodontic, prosthetic and periodontal therapy.

Clinical, pathological and genetic evaluations of Chinese patients with autosomal-dominant hypophosphatasia.

OBJECTIVES: Hypophosphatasia (HPP) is an inherited disorder characterised by defective bone and tooth mineralisation and deficient serum and bone alkaline phosphatase activity, and it results from mutations in alkaline phosphatase (ALPL) encoding tissue-nonspecific alkaline phosphatase (TNAP). The objective of the present work was to explore the correlations between genotype and phenotype in a Chinese family affected by autosomal-dominant HPP. DESIGN: We examined all individuals of a HPP family by clinical and radiographic examinations as well as laboratory assays. Furthermore, a prematurely exfoliated tooth was observed histopathologically. Based on the clinical and pathological manifestations, the causative gene ALPL was selected for further analysis and screened for mutations. RESULTS: The proband presented the characteristic clinical features of childhood HPP such as rachitic skeletal changes, early loss of primary teeth, and short root anomalies of the permanent teeth. Histopathological evaluation of a tooth revealed a "shell" structure, severe mineralisation defects of dentin, and an absence of cementum. The patient's mother and grandfather were clinically diagnosed with adult HPP. The family showed autosomal-dominant moderate hypophosphatasia. DNA sequencing and analysis revealed a novel missense mutation (c.251A>T) in exon4 of ALPL. This mutation (p.E84V) is located in the secondary structure of TNAP's homodimer interface, and it was predicted to have a dominant negative effect. CONCLUSION: Our findings suggest the missense transversion (c.251A>T, p.E84V) should be responsible for the HPP phenotype in this Chinese family.

Endodontic treatment of maxillary first molars presenting with unusual asymmetric palatal root morphology using spiral computerized tomography: a case report.

Variations in root number and canal morphology are challenges for successful endodontic therapy. This report describes 2 endodontically managed maxillary first molars with asymmetric presentation of unusual palatal root morphology. These included the left maxillary first molar with a single palatal root and 2 palatal canals and the right maxillary first molar with 2 separate palatal roots with 1 canal in each root. An accurate diagnosis was confirmed with the help of spiral computerized tomography. This case report discusses this asymmetric variation in the palatal root morphology and highlights the value of spiral computerized tomography in diagnosis of such unusual cases.

[Immunization with the fusion protein of GBD of Streptococcus mutans glucan binding protein-A against dental caries in SD rats].

PURPOSE: To observe the effect of immunization with the fusion protein of GBD of Streptococcus mutans glucan binding protein-A against dental caries. METHODS: Purified fusion protein of GBD of Streptococcus mutans glucan binding protein-A was used to immune SD rats by subcutaneous injection route. The rats were fed with Keyes Diet 2000 and infected by S.mutans. The caries level was determined and the result was analyzed by t test. RESULTS: The caries score of SD rats decreased in the group of immunized with GBD fusion protein,P<0.01. CONCLUSION: Immunization with GBD fusion protein resulted in significantly reduced dental caries after infection with S.mutans Ingbritt. Supported by PLA Tenth Five-Year Key Project (01Z089).