PAR-2 Regulates Dental Pulp Inflammation Associated with Caries

Protease-activated receptors (PARs) are G-protein-coupled receptors that are activated enzymatically by proteolysis of an N-terminal domain. The cleavage and activation of PARs by serine proteases represent a novel mechanism by which such enzymes could influence the host inflammatory response. The aim of this study was to determine whether PAR-2 expression and activation were increased in dental caries. Using immunohistochemistry, we showed PAR-2 to be localized to pulp cells subjacent to caries lesions, but minimally expressed by healthy pulp tissue. Trypsin and the PAR-2 agonist (PAR2-AP) activated PAR-2 in an in vitro functional assay. Endogenous molecules present in pulp cell lysates from carious teeth specifically activated PAR-2, but those from healthy teeth failed to do so. The activation of PAR-2 in vitro was shown to increase the expression of the pro-inflammatory mediator cyclo-oxygenase-2 (COX-2), providing a mechanism whereby PAR-2 could modulate pulpal inflammation.

Palaeobiology of an extinct Ice Age mammal: Stable isotope and cementum analysis of giant deer teeth

The extinct giant deer, Megaloceros giganteus, is among the largest and most famous of the cervids. Megaloceros remains have been uncovered across Europe and western Asia. but the highest concentrations come from Irish bogs and caves Although Megaloceros has enjoyed a great deal of attention over the centuries, paleobiological study has focused oil morphometric and distributional work until now. This paper presents quantitative data that have implications for understanding its sudden extirpation in western Europe during a period of global climate change approximately 10.600 C-14 years ago (ca 12,500 calendar years BP). We report here the first stable isotope analysis of giant deer teeth. which we combine with dental cementum accretion in order to document age, diet and life-history seasonality from birth until death Enamel delta C-13 and delta O-18 measured in the second and third molars from seven individual giant deer Suggest a grass and forbbased diet supplemented with browse in a deteriorating. possibly water-stressed, environment, and a season of birth around spring/early summer Cementurm data indicate that the ages of the specimens ranged from 6.5 to 14 years and that they possessed mature antlers by autumn, similar to extant cervids. In addition. the possibility for combining these two techniques in future mammalian paleoccological studies is considered. The data presented in this study imply that Megoloceros would have indeed been vulnerable to extirpation during the terminal Pleistocene in Ireland. and this information is relevant to understanding the broader pattern of its extinction.

Human Dental Pulp Fibroblasts Express the “Cold-sensing” Transient Receptor Potential Channels TRPA1 and TRPM8

Introduction: Transient receptor potential (TRP) channels comprise a group of nonselective calcium-permeable cationic channels, which are polymodal sensors of environmental stimuli such as thermal changes and chemicals. TRPM8 and TRPA1 are cold-sensing TRP channels activated by moderate cooling and noxious cold temperatures, respectively. Both receptors have been identified in trigeminal ganglion neurones, and their expression in nonneuronal cells is now the focus of much interest. The aim of this study was to investigate the molecular and functional expression of TRPA1 and TRPM8 in dental pulp fibroblasts.
Methods: Human dental pulp fibroblasts were derived from healthy molar teeth. Gene and protein expression was determined by polymerase chain reaction and Western blotting. Cellular localization was investigated by immunohistochemistry, and TRP functionality was determined by Ca2+ microfluorimetry.
Results: Polymerase chain reaction and Western blotting showed gene and protein expression of both TRPA1 and TRPM8 in fibroblast cells in culture. Immunohistochemistry studies showed that TRPA1 and TRPM8 immunoreactivity co-localized with the human fibroblast surface protein. In Ca2+ microfluorimetry studies designed to determine the functionality of TRPA1 and TRPM8 in pulp fibroblasts, we showed increased intracellular calcium ([Ca2+]i) in response to the TRPM8 agonist menthol, the TRPA1 agonist cinnamaldehyde, and to cool and noxious cold stimuli, respectively. The responses to agonists and thermal stimuli were blocked in the presence of specific TRPA1 and TRPM8 antagonists.
Conclusions: Human dental pulp fibroblasts express TRPA1 and TRPM8 at the molecular, protein, and functional levels, indicating a possible role for fibroblasts in mediating cold responses in human teeth.

Overcoming hydrolytic sensitivity and low solubility of phosphitylation reagents by combining ionic liquids with mechanochemistry

Ionic liquids have been used in combination with ball milling on a range of chlorophosphoramidite reagents to phosphitylate nucleosides and 2-deoxynucleosides. The enhanced stability offered by the ionic liquid mediated processes combined with efficient mass transfer induced by ball milling has enabled excellent yields to be obtained even when using small dialkyl amino groups as well as the more commonly used diisopropylamino protection.

A comparison of four extraction methods for substance P, neurokinin A and calcitonin gene-related peptide from human dental pulp tissue

Measuring neuropeptides in biological tissues by radioimmunoassay requires efficient extraction that maintains their immunoreactivity. Many different methods for extraction have been described, but there is little information on optimal extraction methods for individual neuropeptides from human dental pulp tissue. The aim was therefore to identify an effective extraction procedure for three pulpal neuropeptides: substance P. neurokinin A and calcitonin gene-related peptide. Tissue was obtained from 20 pulps taken from teeth freshly extracted for orthodontic reasons. The pulp samples were divided into four equal groups and different extraction methods were used for each group. Boiling whole pulp in acetic acid gave the highest overall yield and, in addition, offered an easy and rapid means of pulp tissue processing. The use of protease inhibitors did not increase the recovery of the immunoreactive neuropeptides but did provide the best combination of maximal recoveries and minimal variability. These results should be useful for planning the extraction of these neuropeptides from human pulp tissue in future studies. (C) 1999 Elsevier Science Ltd. All rights reserved.