Periodontitis, pathogenesis and progression: miRNA-mediated cellular responses to .

is considered a keystone pathogen in periodontitis, a disease typically driven by dysbiosis of oral inflammophilic polymicrobial pathobionts. To combat infectious agents, the natural defense response of the host is to switch on inflammatory signaling cascades, whereby microRNA (miRNA) species serve as alternative genetic inhibitory transcriptional endpoints. miRNA profiles from diseased sites differ from those detected in disease-free tissues.

Anti-proliferative Properties of miR-20b and miR-363 from the miR-106a-363 Cluster on Human Carcinoma Cells.

Background: The miR-106a-363 cluster, encoding six miRNAs (miR- 106a, miR-18b, miR-20b, miR-19b-2, miR-92-2 and miR-363), has been shown to be overexpressed in various tumours. In oral carcinoma cells, however only miR- 106a was detectable from this cluster. We have investigated how effects of transfection of oral carcinoma cells with a non-expressed member of this cluster affect mRNA transcriptomes and cellular selected functions.

Mapping the global mRNA transcriptome during development of the murine first molar.

The main objective of this study was to map global gene expression in order to provide information about the populations of mRNA species participating in murine tooth development at 24 h intervals, starting at the 11th embryonic day (E11.5) up to the 7th post-natal day (P7). The levels of RNA species expressed during murine tooth development were mesured using a total of 58 deoxyoligonucleotide microarrays.

An investigation into anti-proliferative effects of microRNAs encoded by the miR-106a-363 cluster on human carcinoma cells and keratinocytes using microarray profiling of miRNA transcriptomes.

Transfection of human oral squamous carcinoma cells (clone E10) with mimics for unexpressed miR-20b or miR-363-5p, encoded by the miR-106a-363 cluster (miR-20b, miR-106a, miR-363-3p, or miR-363-5p), caused 40-50% decrease in proliferation. Transfection with mimics for miR-18a or miR-92a, encoded by the miR-17-92 cluster (all members being expressed in E10 cells), had no effect on proliferation. In contrast, mimic for the sibling miRNA-19a yielded about 20% inhibition of proliferation.

Expression of Clu and Tgfb1 during murine tooth development: effects of in-vivo transfection with anti-miR-214.

Expression of clusterin (Clu) in the murine first molar tooth germ was markedly increased at postnatal developmental stages. The time-course of expression of this gene paralleled those of other genes encoding proteins involved during the secretory phase of odontogenesis, as described previously. Immunohistochemical studies of clusterin in murine molar tooth germs suggested this protein to be located in outer enamel epithelium, regressing enamel organ, secretory ameloblasts, and the dental epithelium connecting the tooth to the oral epithelium at an early eruptive stage.

Gene Expression Profiling during Murine Tooth Development.

The aim of this study was to describe the expression of genes, including ameloblastin (Ambn), amelogenin X chromosome (Amelx), and enamelin (Enam) during early (pre-secretory) tooth development. The expression of these genes has predominantly been studied at post-secretory stages. Deoxyoligonucleotide microarrays were used to study gene expression during development of the murine first molar tooth germ at 24 h intervals, starting at the 11th embryonic day (E11.

Expression of delta-like 1 homologue and insulin-like growth factor 2 through epigenetic regulation of the genes during development of mouse molar.

Delta-like 1 homolog (Dlk1) and insulin-like growth factor 2 (Igf2) are two of six well-studied mouse imprinted gene clusters that are paternally expressed. Their expression is also linked to their maternally expressed non-coding RNAs, encoded by Gene trap locus 2 (Gtl2) and Imprinted maternally expressed transcript (H19), co-located as imprinted gene clusters. Using deoxyoligonucleotide microarrays and real-time RT-PCR analysis we showed Dlk1 and Gtl2 to exhibit a time-course of expression during tooth development that was similar to that of Igf2 and H19.

Deoxyoligonucleotide microarrays for gene expression profiling in murine tooth germs.

The use of deoxyoligonucleotide microarrays facilitates rapid expression profiling of gene expression using samples of about 1 μg of total RNA. Here are described practical aspects of the procedures involved, including essential reagents. Analysis of results is discussed from a practical, experimental, point of view together with software required to carry out the required statistical analysis to isolate populations of differentially expressed genes.

Expression of members of the miRNA17-92 cluster during development and in carcinogenesis.

The six microRNAs (miRNA) encoded by the miR-17-92 cluster, also named oncomir-1, have been associated with carcinogenesis and typically exhibit-increased expression in tumors. Despite the well-established role for the miR-17-92 cluster in an oncogenic network, the physiological function of these miRNAs in normal tissues remains unresolved. In order to investigate whether there are similar patterns of miR-17-92 expression during embryogenesis and carcinogenesis, we have preformed a systematic study of the expression in cultured carcinoma cells, cultured primary human keratinocytes (KC), and during development of some murine tissues.

Effects of in vivo transfection with anti-miR-214 on gene expression in murine molar tooth germ.

MicroRNAs (miRNAs) are an abundant class of noncoding RNAs that are believed to be important in many biological processes through regulation of gene expression. Little is known of their function in tooth morphogenesis and differentiation. MicroRNA-214 (miR-214), encoded by the polycistronic Dnm30os gene, is highly expressed during development of molar tooth germ and was selected as a target for silencing with anti-miR-214.

Expression of prion gene and presence of prion protein during development of mouse molar tooth germ.

In order to gain insight into possible cellular functions of the prion protein (PrP) during normal development, the expression of Prnp (encoding the PrP) and the distribution of the PrP were studied in murine tooth germs. Expression of Prnp in the mouse first molar tooth germ was highly dynamic, increasing several-fold during the secretory phase of odontogenesis, exhibiting a time-course of expression similar to that of genes coding for other extracellular proteins [e.g.

Gene expression and dental enamel structure in developing mouse incisor.

At the mouse incisor tip the initially differentiated ameloblasts produce a thin, prism-free enamel, while further apically, in the immediate adjacent segment, the enamel thickness increases and the four-layered enamel of mouse incisor is formed. Comparative gene-expression profiling was carried out on RNA isolated from these two segments of incisor tooth germs at embryonic day (E)17.5 and at postnatal days (P)0, 1, 2, and 10 using microarrays to measure messenger RNA (mRNA) and microRNA (miRNA) species present in the segments.

Signal transduction and gene transcription induced by TFF3 in oral keratinocytes.

Trefoil factor family 3 (TFF3) is secreted in saliva. The peptide improves the mechanical and chemical resistance of mucins, and it may act as a motility signal for oral keratinocytes during wound healing. This study aimed to identify novel functions of TFF3 in oral keratinocytes.

Family-with-sequence-similarity-46, member A (Fam46a) gene is expressed in developing tooth buds.

Objective: In search for possible novel genes that may be involved in tooth development, we analysed the genome-wide transcriptome of developing mandibular tooth germs of mouse during embryonic and early life and selected family-with-sequence-similarity-46, member A (Fam46a) gene for further expression analysis.

Methods: We applied microarray, quantitative real time polymerase chain reaction and in situ hybridisation methods for the expression study of the mouse Fam46a gene.

Results: We found the family-with-sequence-similarity-46, member A (Fam46a) gene to be highly expressed and further verify its temporo-spatial expression in the mouse tooth.

Differential gene expression profiling of the molar tooth germ in peroxisome proliferator-activated receptor-alpha (PPAR-alpha) knockout mouse and in wild-type mouse: molar tooth phenotype of PPAR-alpha knockout mouse.

Gene expression profiling of the first molar tooth germ at embryonic days (E)17.5 and 18.5, and at postnatal days (P)0, 2, and 6 from peroxisome proliferator-activated receptor-alpha (PPAR-alpha) knockout mouse and from wild-type mouse was carried out using microarrays and validated using real-time reverse transcription-polymerase chain reaction (RT-PCR) and western blotting.

Comparative hepatic gene expression profiling of rats treated with 1H,1H,2H,2H-heptadecafluorodecan-1-ol or with pentadecafluorooctanoic acid.

Pentadecafluorooctanoic acid is an established peroxisome proliferator. Little is known about effects of treatment with 1H,1H,2H,2H-heptadecafluorodecan-1-ol, which is metabolized to pentadecafluorooctanoic acid. We compared effects of various dosages (3, 10, or 25 mg/kg body wt) of each of these compounds on hepatic gene expression in rats with microarrays.

MicroRNA expression profiling of the developing murine molar tooth germ and the developing murine submandibular salivary gland.

Using microarrays, miRNA expression profiles have been established at selected times during development (E15.5, P0 and P5) of the murine first molar mandibular tooth germ and the right submandibular salivary gland (E15.5, P0, P5 and P25).

Changes in gene-expression during development of the murine molar tooth germ.

In a matter of a few days the murine tooth germ develops into a complex, mineralized, structure. Murine 30K microarrays were used to examine gene expression in the mandibular first molar tooth germs isolated at 15.5dpc and at 2DPN.

Enhanced susceptibility to periodontitis in an animal model of depression: reversed by chronic treatment with the anti-depressant tianeptine.

Objective: To test the hypothesis that the olfactory bulbectomy model of depression in rats could influence susceptibility to ligature-induced periodontitis, and that chronic treatment with the anti-depressant drug tianeptine could attenuate this effect.

Material And Methods: Tianeptine was given twice daily (10 mg/kg, i.p.

Neonatal dexamethasone and chronic tianeptine treatment inhibit ligature-induced periodontitis in adult rats.

Objective: The responsiveness of the hypothalamic-pituitary-adrenal (HPA) axis has been found to play a significant role for susceptibility and resistance to periodontal disease. In the present study we have investigated the effects of two different treatment strategies, which have been found to down-regulate the HPA axis, on ligature-induced periodontitis.

Methods: In experiment 1, newborn rats were treated with the synthetic glucocorticoid hormone dexamethasone-21-phosphate, which permanently down-regulates HPA axis responsiveness.

Effects on cholinergic markers in rat brain and blood after short and prolonged administration of donepezil.

Donepezil is a selective inhibitor of acetylcholinesterase (AChE) clinically used for treating Alzheimer's disease. Cholinergic effects after short-term exposure of donepezil (up to 12 h) have been extensively studied in rats, but few have addressed the potential long-term effects. After 14 days administration (1x3 mg/kg, decapitation 4 h after the last injection) the cerebral acetylcholine level was increased by 35% and the AChE activity was decreased by 66% and 32% in brain and blood, respectively.

Activity of peroxisomal enzymes, and levels of polyamines in LPA-transgenic mice on two different diets.

Background: In man, elevated levels of plasma plipoprotein (a) (Lp(a)) is a cardiovascular risk factor, and oxidized phospholipids are believed to play a role as modulators of inflammatory processes such as atherosclerosis. Polyamines are potent antioxidants and anti-inflammatory agents. It was therefore of interest to examine polyamines and their metabolism in LPA transgenic mice.

Chronic treatment with the glutamate receptor antagonist MK-801 alters periodontal disease susceptibility.

Objective: Previous experiments in rats suggest that hypothalamic-pituitary-adrenal (HPA) axis over-responsiveness, which leads to increased secretion of immunoregulatory glucocorticoid hormones, increases periodontal disease susceptibility, whereas HPA axis under-responsiveness is associated with increased resistance to the disease. The present study was designed to investigate whether MK-801 (dizocilipine malate), an antagonist of the glutamate receptor N-methyl-D-aspartate (NMDA) in the brain, which has been found to play an important role in the regulation of the HPA axis, would influence the outcome of experimental ligature-induced periodontal disease in a rat model.

Methods: Experimental periodontal disease was induced in periodontal disease susceptible and HPA axis high-responding Fischer 344 rats 2 days before chronic treatment with MK-801(1 mg/kg intraperitoneally).

Effects of in vivo treatment of rats with trimethyltin chloride on respiratory properties of rat liver mitochondria.

Liver mitochondria isolated from rats treated in vivo with trimethyltin chloride show stimulation of respiration using glutamate/malate as substrate, and a transient inhibition on rates of respiration using palmitoyl-L-carnitine as substrate. This phenomenon was observed with both ADP- and FCCP-stimulated respiration. In contrast, rates of respiration by liver mitochondria isolated from rats treated in vivo with trimethyltin chloride, following prior treatment with clofibrate, were inhibited when glutamate/malate was respiratory substrates.