Highly Ordered Nanotube-Like Microstructure on Titanium Dental Implant Surface Fabricated via Anodization Enhanced Cell Adhesion and Migration of Human Gingival Fibroblasts.

Background: Titanium (Ti) surface with nanotubes array via anodization has been used in dental implants to enhance bone regeneration but little research was carried out to evaluate whether the presence of highly ordered or disorderly distributed nanotubes array on titanium surface would have an effect on cell behaviors of gingival fibroblasts. Methods: The present study fabricated nanotubes arrays with varied topography under different constant voltage of electrochemical anodization in fluorine-containing electrolyte. Human gingival fibroblasts (HGFs) from extracted third molar were harvested and co-cultured with titanium disks with different nanotubes topography. Then cell behaviors of gingival fibroblasts including cell proliferation, adhesive morphology and cell migration were estimated to investigate the influence of titanium nanotubes on cell biology. Besides, gene and protein expression of adhesion molecule (integrin ß1/ß4/α6, fibronectin, intracellular adhesion molecule-1 and collagen type I) were detected to evaluate the influence of different surfaces on cell adhesion. Results: Highly ordered arrays of nanotubes with pore diameter of 60 nm and 100 nm were fabricated under 30 and 40 V of anodization (TNT-30 and TNT-40) while disorderedly distributed nanotube arrays formed on the titanium surface under 50 V of anodization (TNT-50). Our results demonstrated that compared with raw titanium surface and disorderly nanotubes, surface with orderly nanotubes array increased cell area and aspect ratio, as well as cell migration ability in the early phase of cell adhesion (p<0.05). Besides, compared with raw titanium surface, gene and protein expression of adhesion molecules were upregulated in nanotubes groups to different extents, no matter whether in an orderly or disorderly array. Conclusion: Within the limitations of our study, we conclude that compared with raw titanium surface, the presence of nanotubes array on titanium surface could enhance cells adhesion and cell migration in the early phase. And compared with disorderly distributed nanotubes, highly ordered nanotubes array might provide a much more favorable surface for gingival fibroblasts to achieve a tight adhesion on the materials.

The moderating role of informatization between country risks and international tourism: A cross-country panel analysis.

Informatization plays an increasingly important role in the tourism industry, while its effectiveness in alleviating tourism risks remains to be verified. This research aims to explore the effects of country risks on the international tourism and the moderating role of informatization between the two. This study firstly measures country risks based on the ICRG database, quantifies international tourism by tourism revenue, tourism expenditure, and tourist arrival, and calculates informatization level from informatization facilities, informatization applications, and informatization skills. A dynamic SYS-GMM model is then adopted to verify the research hypotheses based on the panel data of 138 countries from 2000 to 2019. The research results show that the composite country risk, political risk, economic risk, and financial risk all show a negative impact on the international tourism indicators regardless of different time periods, regions, or income levels. However, the effects are more obvious before the global financial crisis in 2008 and regions and countries with lower income levels. In addition, informatization is found to positively mitigate the adverse impacts of country risks on international tourism, especially for economic and financial risks. The research findings indicate the risk hedge potential of informatization in the tourism industry, which provides a profound reference for destination risk management.

Integration of collagen fibers in connective tissue with dental implant in the transmucosal region.

Dental implants have been widely accepted as an ideal therapy to replace the missing teeth for its good performance in aspects of mechanical properties and aesthetic outcomes. Its restorative success is contributed by not only the successful osseointegration of the implant but also the tight soft tissue integration, especially the collagen fibers, in the transmucosal region. Soft tissue attaching to the dental implant/abutment is overall similar, but in some aspects distinct with that seen around natural teeth and soft tissue integration can be enhanced via several surface modification methods. This review is going to focus on the current knowledge of the transmucosal zone around the dental implants (compared with natural teeth), and latest strategies in use to fine-tune the collagen fibers assembly in the connective tissue, in an attempt to enhance soft tissue integration.

DLX6 promotes cell proliferation and survival in oral squamous cell carcinoma.

OBJECTIVE: Distal-less homeobox 6 (DLX6) has been reported to play important roles in the development of craniofacial structures, inner ear, limb, and brain. We found in our previous investigation that DLX6 was significantly highly expressed in oral cancer tissues in The Cancer Genome Atlas database. This study aimed to explore its roles and regulation mechanism in oral squamous cell carcinoma. MATERIALS AND METHODS: We analyzed the expression of DLX6 and its association with overall survival in OSCC by real-time quantitative PCR. Besides, clone formation, proliferation, and apoptosis were detected after knocking down DLX6 and microarray analysis was performed to explore the possible regulatory mechanism. RESULTS: DLX6 was overexpressed in oral cancer tissues and was associated with advance tumor stage and poor prognosis. In vitro studies have shown that DLX6 promotes proliferation and inhibits cell apoptosis in oral cancer cells. Microarray analysis along with Western blotting results indicated that DLX6 significantly associated with malignant tumors and may regulate OSCC cells proliferation through EGFR-CCND1 axis. CONCLUSION: DLX6 promotes cell proliferation and suppresses cell apoptosis in oral cancer cells. EGFR-CCND1 pathway might be the potential mechanism participating in the regulating axis.

Anlotinib as a promising inhibitor on tumor growth of oral squamous cell carcinoma through cell apoptosis and mitotic catastrophe.

BACKGROUND: Oral squamous cell carcinoma (OSCC) has been one of the most malignant cancers in head and neck region. Anlotinib is a tyrosine kinase inhibitor targeting several receptors such as vascular endothelial growth factor receptor (VEGFR), fibroblast growth factor receptor (FGFR), platelet-derived growth factor receptor (PDGFR) and c-Kit. Here we investigated whether Anlotinib have any antitumor effect on oral cancer and tried to explore and explain the possible mechanism. METHODS: Data from The Cancer Genome Atlas and the Gene Expression Omnibus and Gene Expression Omnibus database was collected to analyze the relationship between the expression of vascular epithelial growth factor receptor 2 and the overall survival rate of OSCC. Oral cancer cell lines Cal-27 and SCC-25 were cultured to conduct all the experiments. In vitro experiments such as CCK-8, colony formation, cell cycle assay and cell apoptosis assay were conducted to detect cell proliferation ability and the change of cell phase and apoptosis. Proteins concerning cell cycle and cell apoptosis were visualized via western blot. α-Tubulin were visualized via immunofluorescence to detect cells undergoing mitotic catastrophe. RESULTS: Higher expression of VEGFR-2 was significantly related to poorer prognosis. Experiment in vitro demonstrated that cell proliferation was significantly inhibited(p < 0.05) after Anlotinib administration and G2/M arrest and apoptosis were both detected in both cell lines. Cycle-related proteins promoting cell cycle progression and proteins related to cell survival were downregulated in Anlotinib group compared to the control group. Cell-death-related biomarker and phosphorylated histone 3 were upregulated in expression in Anlotinib group. Abnormal spindle apparatus was observed in cells undergoing mitotic catastrophe. CONCLUSIONS: Anlotinib could exert an antitumor effect on oral cancer cell lines via apoptotic pathway and mitotic catastrophe pattern, presenting a promising potential therapy for patients with OSCC.

Obesity-Linked PPARγ S273 Phosphorylation Promotes Insulin Resistance through Growth Differentiation Factor 3.

The thiazolidinediones (TZDs) are ligands of PPARγ that improve insulin sensitivity, but their use is limited by significant side effects. Recently, we demonstrated a mechanism wherein TZDs improve insulin sensitivity distinct from receptor agonism and adipogenesis: reversal of obesity-linked phosphorylation of PPARγ at serine 273. However, the role of this modification hasn't been tested genetically. Here we demonstrate that mice encoding an allele of PPARγ that cannot be phosphorylated at S273 are protected from insulin resistance, without exhibiting differences in body weight or TZD-associated side effects. Indeed, hyperinsulinemic-euglycemic clamp experiments confirm insulin sensitivity. RNA-seq in these mice reveals reduced expression of Gdf3, a BMP family member. Ectopic expression of Gdf3 is sufficient to induce insulin resistance in lean, healthy mice. We find Gdf3 inhibits BMP signaling and insulin signaling in vitro. Together, these results highlight the diabetogenic role of PPARγ S273 phosphorylation and focus attention on a putative target, Gdf3.

Unusual clinical and histologic findings in a child with mixed dentition with hereditary gingival fibromatosis: a case report.

Hereditary gingival fibromatosis (HGF) is characterized by an accumulation of extracellular matrix resulting in a fibrotic enlargement of keratinized gingiva. The goal of this article is to describe one kindred affected with HGF and discuss the diagnosis, treatment, recurrence risk and histopathology features of the proband with mixed dentition. An 8-year-old boy reported with a chief complaint of gingival enlargement. A series of examinations were performed to make a diagnosis and family histories of the patient were recorded. Surgical therapy included gingivectomy and gingivoplasty technique were performed for the proband to remove excess gingiva. Collagen bundles in the permanent incisors area were prevalently significantly bulkier than that of the deciduous teeth area and the arrangement was much more regular. Microscopic evaluation revealed that epithelial hyperplasia was severe in tissue with intense inflammation, whereas tissue with mild inflammation showed only long and deep epithelial papillae. The patient was placed on a 3-month recall schedule and didn't demonstrate any recurrence of gingival overgrowth over a 1-year follow-up period. The study revealed that the eruption of permanent teeth played an important role in accelerating gingival hyperplasia. For the first time, it was confirmed from histological perspective that inflammation in gingival tissue was crucial to the gingival overgrowth of HGF.

B4GALNT1 enhances cell proliferation and growth in oral squamous cell carcinoma via p38 and JNK MAPK pathway.

BACKGROUND: Beta-1,4-N-Acetyl-Galactosaminyltransferase 1 (B4GALNT1) was reported to play an important role in the development of the central nervous systems. We found higher expression of B4GALNT1 in oral squamous cell carcinoma (OSCC) tissues compared to the paired normal adjacent tissues in the TCGA database. This study aimed to investigate whether there was a potential relationship between B4GALNT1 and OSCC tumorigenesis and further explored the possible regulation mechanism. METHODS: Gene expression level was analyzed by means of real-time quantitative PCR and further cell function experiments were performed including cell proliferation and apoptosis test, cell cycle distribution detection after silencing B4GALNT1 by transfection with B4GALNT1-shRNA lentivirus. Western Blotting was carried out to explore the possible molecular mechanism. RESULTS: The present study confirmed the overexpression of B4GALNT1 in OSCC. Compared to the control group, cell proliferation after silencing B4GALNT1 was significantly inhibited and cell apoptosis percentage was significantly higher. Besides, the knockdown of B4GALNT1 resulted in cell cycle arrest at G1 phase in our experiment. CONCLUSIONS: B4GALNT1 enhances the proliferation and suppress the apoptosis of OSCC cells probably through JNK and p38 signaling pathway.

Stafne's bone defect: a case report and review of literatures.

Stafne's bone defect (SBD) or Stafne's bone cavity (SBC) is an uncommon bony defect occurred especially only at the lingual cortex of mandible. Clinically, patients with SBD are usually asymptomatic. In most cases, the defect is observed accidentally via X-ray panorama during other dental treatments. Here we presented a female with SBD and we reviewed relevant literatures on SBD, summarized the clinical characteristic and radiographic features with our experiences.

Ablation of PM20D1 reveals N-acyl amino acid control of metabolism and nociception.

N-acyl amino acids (NAAs) are a structurally diverse class of bioactive signaling lipids whose endogenous functions have largely remained uncharacterized. To clarify the physiologic roles of NAAs, we generated mice deficient in the circulating enzyme peptidase M20 domain-containing 1 (PM20D1). Global PM20D1-KO mice have dramatically reduced NAA hydrolase/synthase activities in tissues and blood with concomitant bidirectional dysregulation of endogenous NAAs. Compared with control animals, PM20D1-KO mice exhibit a variety of metabolic and pain phenotypes, including insulin resistance, altered body temperature in cold, and antinociceptive behaviors. Guided by these phenotypes, we identify N-oleoyl-glutamine (C18:1-Gln) as a key PM20D1-regulated NAA. In addition to its mitochondrial uncoupling bioactivity, C18:1-Gln also antagonizes certain members of the transient receptor potential (TRP) calcium channels including TRPV1. Direct administration of C18:1-Gln to mice is sufficient to recapitulate a subset of phenotypes observed in PM20D1-KO animals. These data demonstrate that PM20D1 is a dominant enzymatic regulator of NAA levels in vivo and elucidate physiologic functions for NAA signaling in metabolism and nociception.

Phosphorylation of Beta-3 adrenergic receptor at serine 247 by ERK MAP kinase drives lipolysis in obese adipocytes.

OBJECTIVE: The inappropriate release of free fatty acids from obese adipose tissue stores has detrimental effects on metabolism, but key molecular mechanisms controlling FFA release from adipocytes remain undefined. Although obesity promotes systemic inflammation, we find activation of the inflammation-associated Mitogen Activated Protein kinase ERK occurs specifically in adipose tissues of obese mice, and provide evidence that adipocyte ERK activation may explain exaggerated adipose tissue lipolysis observed in obesity. METHODS AND RESULTS: We provide genetic and pharmacological evidence that inhibition of the MEK/ERK pathway in human adipose tissue, mice, and flies all effectively limit adipocyte lipolysis. In complementary findings, we show that genetic and obesity-mediated activation of ERK enhances lipolysis, whereas adipose tissue specific knock-out of ERK2, the exclusive ERK1/2 protein in adipocytes, dramatically impairs lipolysis in explanted mouse adipose tissue. In addition, acute inhibition of MEK/ERK signaling also decreases lipolysis in adipose tissue and improves insulin sensitivity in obese mice. Mice with decreased rates of adipose tissue lipolysis in vivo caused by either MEK or ATGL pharmacological inhibition were unable to liberate sufficient White Adipose Tissue (WAT) energy stores to fuel thermogenesis from brown fat during a cold temperature challenge. To identify a molecular mechanism controlling these actions, we performed unbiased phosphoproteomic analysis of obese adipose tissue at different time points following acute pharmacological MEK/ERK inhibition. MEK/ERK inhibition decreased levels of adrenergic signaling and caused de-phosphorylation of the ß3-adrenergic receptor (ß3AR) on serine 247. To define the functional implications of this phosphorylation, we showed that CRISPR/Cas9 engineered cells expressing wild type ß3AR exhibited ß3AR phosphorylation by ERK2 and enhanced lipolysis, but this was not seen when serine 247 of ß3AR was mutated to alanine. CONCLUSION: Taken together, these data suggest that ERK activation in adipocytes and subsequent phosphorylation of the ß3AR on S247 are critical regulatory steps in the enhanced adipocyte lipolysis of obesity.

Cdkal1, a type 2 diabetes susceptibility gene, regulates mitochondrial function in adipose tissue.

OBJECTIVES: Understanding how loci identified by genome wide association studies (GWAS) contribute to pathogenesis requires new mechanistic insights. Variants within CDKAL1 are strongly linked to an increased risk of developing type 2 diabetes and obesity. Investigations in mouse models have focused on the function of Cdkal1 as a tRNALys modifier and downstream effects of Cdkal1 loss on pro-insulin translational fidelity in pancreatic ß-cells. However, Cdkal1 is broadly expressed in other metabolically relevant tissues, including adipose tissue. In addition, the Cdkal1 homolog Cdk5rap1 regulates mitochondrial protein translation and mitochondrial function in skeletal muscle. We tested whether adipocyte-specific Cdkal1 deletion alters systemic glucose homeostasis or adipose mitochondrial function independently of its effects on pro-insulin translation and insulin secretion. METHODS: We measured mRNA levels of type 2 diabetes GWAS genes, including Cdkal1, in adipose tissue from lean and obese mice. We then established a mouse model with adipocyte-specific Cdkal1 deletion. We examined the effects of adipose Cdkal1 deletion using indirect calorimetry on mice during a cold temperature challenge, as well as by measuring cellular and mitochondrial respiration in vitro. We also examined brown adipose tissue (BAT) mitochondrial morphology by electron microscopy. Utilizing co-immunoprecipitation followed by mass spectrometry, we performed interaction mapping to identify new CDKAL1 binding partners. Furthermore, we tested whether Cdkal1 loss in adipose tissue affects total protein levels or accurate Lys incorporation by tRNALys using quantitative mass spectrometry. RESULTS: We found that Cdkal1 mRNA levels are reduced in adipose tissue of obese mice. Using adipose-specific Cdkal1 KO mice (A-KO), we demonstrated that mitochondrial function is impaired in primary differentiated brown adipocytes and in isolated mitochondria from A-KO brown adipose tissue. A-KO mice displayed decreased energy expenditure during 4 °C cold challenge. Furthermore, mitochondrial morphology was highly abnormal in A-KO BAT. Surprisingly, we found that lysine codon representation was unchanged in Cdkal1 A-KO adipose tissue. We identified novel protein interactors of CDKAL1, including SLC25A4/ANT1, an inner mitochondrial membrane ADP/ATP translocator. ANT proteins can account for the UCP1-independent basal proton leak in BAT mitochondria. Cdkal1 A-KO mice had increased ANT1 protein levels in their white adipose tissue. CONCLUSIONS: Cdkal1 is necessary for normal mitochondrial morphology and function in adipose tissue. These results suggest that the type 2 diabetes susceptibility gene CDKAL1 has novel functions in regulating mitochondrial activity.