MiR-200b attenuates IL-6 production through IKKß and ZEB1 in human gingival fibroblasts.

OBJECTIVE: MicroRNAs (miRNAs) play important roles in biological processes such as cell differentiation, development, infection, immune response, inflammation and tumorigenesis. We previously reported that the expression of miR-200b was significantly increased in inflamed gingiva compared with non-inflamed gingiva. To elucidate the roles of miR-200b in the inflamed gingiva, we have analyzed the effects of miR-200b on the expression of IL-6 in human gingival fibroblasts (HGF). MATERIALS AND METHODS: Total RNA and protein were extracted from HGF after stimulation by interleukin-1ß (IL-1ß; 1 ng/ml) or tumor necrosis factor-α (TNF-α; 10 ng/ml) and transfected with miR-200b expression plasmid or miR-200b inhibitor. IL-6, IL-1ß, inhibitor of nuclear factor kappa-B kinaseß (IKKß), Zinc-finger E-box-binding homeobox 1 (ZEB1) and E-cadherin mRNA and protein levels were analyzed by real-time PCR and Western blot. RESULTS: IL-1ß and TNF-α increased IL-6 mRNA and protein levels, and they were significantly suppressed by miR-200b overexpression, whereas they were further increased by miR-200b inhibitor in HGF. IKKß and ZEB1 which are target genes of miR-200b negatively regulate E-cadherin. MiR-200b suppressed the expression of IKKß and ZEB1 and increased E-cadherin mRNA and protein levels in HGF. CONCLUSIONS: These results suggest that miR-200b attenuates inflammatory response via IKKß and ZEB1 in periodontal tissue.

Hydrogen Bond Induces Hierarchical Self-Assembly in Liquid-Crystalline Block Copolymers.

Microphase-separated structures of block copolymers (BCs) with a size of sub-10 nm are usually obtained by hydrogen-bond-induced self-assembly of BCs through doping with small molecules as functional additives. Here, fabrication of hierarchically self-assembled sub-10 nm structures upon microphase separation of amphiphilic liquid-crystalline BCs (LCBCs) at the existence of hydrogen bonds but without any dopants is reported. The newly introduced urethane groups in the side chain of the hydrophobic block of LCBCs interact with the ether groups of the hydrophilic poly(ethylene oxide) (PEO) block, leading to imperfect crystallization of the PEO blocks. Both crystalline and amorphous domains coexist in the separated PEO phase, enabling a lamellar structure to appear inside the PEO nanocylinders. This provides an elegant method to fabricate controllable sub-10 nm microstructures in well-defined polymer systems without the introduction of any dopants.

Transcriptional regulation of amelotin gene by proinflammatory cytokines in gingival fibroblasts.

Amelotin (AMTN) is a secreted protein expressed during the late stages of enamel formation and in the junctional epithelium. Among many differentially expressed genes, we found significantly increased AMTN mRNA level in inflamed gingiva by DNA microarray. The inductions of AMTN mRNA expressions in inflamed gingiva and human gingival fibroblasts (HGF) were confirmed by real-time polymerase chain reaction. To determine the molecular basis of the expression of AMTN and its regulation by proinflammatory cytokines, we have isolated and characterized the promoter region of mouse AMTN gene. Transient transfection assays were performed using luciferase constructs including mouse AMTN gene promoter. Interleukin-1ß, Interleukin-6 and tumor necrosis factor-α induced AMTN mRNA levels in HGF. These cytokines increased the luciferase activities of the AMTN promoter constructs in HGF. The results suggest that proinflammatory cytokines induce AMTN gene transcription and a role for AMTN in gingival inflammation.

Reverse adhesion of a gecko-inspired synthetic adhesive switched by an ion-exchange polymer-metal composite actuator.

Inspired by how geckos abduct, rotate, and adduct their setal foot toes to adhere to different surfaces, we have developed an artificial muscle material called ion-exchange polymer-metal composite (IPMC), which, as a synthetic adhesive, is capable of changing its adhesion properties. The synthetic adhesive was cast from a Si template through a sticky colloid precursor of poly(methylvinylsiloxane) (PMVS). The PMVS array of setal micropillars had a high density of pillars (3.8 × 10(3) pillars/mm(2)) with a mean diameter of 3 µm and a pore thickness of 10 µm. A graphene oxide monolayer containing Ag globular nanoparticles (GO/Ag NPs) with diameters of 5-30 nm was fabricated and doped in an ion-exchanging Nafion membrane to improve its carrier transfer, water-saving, and ion-exchange capabilities, which thus enhanced the electromechanical response of IPMC. After being attached to PMVS micropillars, IPMC was actuated by square wave inputs at 1.0, 1.5, or 2.0 V to bend back and forth, driving the micropillars to actively grip or release the surface. To determine the adhesion of the micropillars, the normal adsorption and desorption forces were measured as the IPMC drives the setal micropillars to grip and release, respectively. Adhesion results demonstrated that the normal adsorption forces were 5.54-, 14.20-, and 23.13-fold higher than the normal desorption forces under 1.0, 1.5, or 2.0 V, respectively. In addition, shear adhesion or friction increased by 98, 219, and 245%, respectively. Our new technique provides advanced design strategies for reversible gecko-inspired synthetic adhesives, which might be used for spiderman-like wall-climbing devices with unprecedented performance.

Enamel hypoplasias related to famine stress in living Chinese.

The relationship between linear enamel hypoplasia (LEH) and nutritional stress caused by a grave historical famine (1959-1961) was investigated among contemporary Chinese. Based on dental observations in a sample of 3,014 subjects from rural and urban China, and data on famine stress from a variety of historical sources, hypotheses regarding the relation between LEH and nutritional stress were tested. Famine stress raised LEH prevalence significantly in the birth cohorts having their teeth developing during famine years; therefore, a correlation between nutritional stress and formation of LEH as suggested by previous studies was indicated. Rural subjects had significantly higher LEH prevalence than urban subjects, and this was attributed to poorer nutritional and living conditions in rural areas. Males had a slightly higher LEH prevalence than females, so that female biological buffering to environmental stress appears to have outweighed possible cultural practice of daughter neglect in this difference. Am. J. Hum. Biol. 10:723-733, 1998. © 1998 Wiley-Liss, Inc.

MicroRNA expression in inflamed and noninflamed gingival tissues from Japanese patients.

Periodontitis is a chronic inflammatory disease caused by specific bacteria and viruses. Local, systemic, and environmental factors affect the rate of disease progression. Immune responses to bacterial products, and the subsequent production of inflammatory cytokines, are crucial in the destruction of periodontal tissue. MicroRNAs (miRNAs) are a class of small RNAs that control various cell processes by negatively regulating protein-coding genes. In this study, we compared miRNA expression in inflamed and noninflamed gingival tissues from Japanese dental patients. Total RNAs were isolated from inflamed and noninflamed gingival tissues. miRNA expression profiles were examined by an miRNA microarray, and the data were analyzed by GeneSpring GX, Ingenuity Pathways Analysis, and the TargetScan databases. Observed miRNA expression levels in inflamed gingiva were confirmed by real-time PCR. The three most overexpressed (by >2.72-fold) miRNAs were hsa-miR-150, hsa-miR-223, and hsa-miR-200b, and the three most underexpressed (by <0.39-fold) miRNAs were hsa-miR-379, hsa-miR-199a-5p, and hsa-miR-214. In IPA analysis, hsa-miR-150, hsa-miR-223, and hsa-miR-200b were associated with inflammatory disease, organismal injury, abnormalities, urological disease, and cancer. The present findings suggest that miRNAs are associated with chronic periodontitis lesions in Japanese.

Proinflammatory cytokines induce amelotin transcription in human gingival fibroblasts.

Amelotin (AMTN) is a secreted protein transcribed predominantly during the maturation stage of enamel formation and localized in the junctional epithelium. We investigated differences in the levels of AMTN gene expression between non-inflamed gingiva and inflamed gingiva from patients with chronic periodontitis. Total RNAs were isolated from these tissues and their gene expression profiles were monitored by DNA microarray. The observed induction of AMTN mRNA in inflamed gingiva and cultured human gingival fibroblasts (HGF) was confirmed by real-time PCR. Transient transfection assays were performed using chimeric constructs of mouse AMTN gene promoter fragments linked to a luciferase reporter gene. Immunohistochemical localization of AMTN in inflamed and non-inflamed gingiva was assessed by immunohistochemistry. Among many differentially expressed genes, the level of AMTN mRNA was significantly increased in inflamed gingiva. Treatment of HGF with interleukin-1ß (IL-1ß), IL-6 and tumor necrosis factor-α (TNF-α) induced the expression of AMTN mRNA, and increased the luciferase activities of the AMTN promoter constructs. AMTN protein was detected in inflamed gingival connective tissue and junctional epithelium. These findings demonstrate that proinflammatory cytokines induce AMTN gene expression in human gingival fibroblasts and suggest a role for AMTN in gingival inflammation.