Data from a targeted proteomics approach to discover biomarkers in saliva for the clinical diagnosis of periodontitis.

This study focused on the search for new biomarkers based on liquid chromatography-multiple reaction monitoring (LC-MRM) proteomics profiling of whole saliva from patients with periodontitis compared to healthy subjects. The LC-MRM profiling approach is a new and innovative method that has already been validated for the absolute and multiplexed quantification of biomarkers in several diseases. The dataset for this study was produced using LC-MRM to monitor protein levels in a multiplex assay, it provides clinical information on salivary biomarkers of periodontitis. The data presented here is an extension of our recently published research article (Mertens et al., 2017) [1].

Preproglucagon mRNA expression in adult rat submandibular glands.

Salivary glands of various animal species have been reported to contain and suggested to produce glucagon or glucagon-like material, but the origin and the nature of this salivary peptide are still doubtful. The present study was undertaken to ascertain whether the glucagon gene is expressed in rat submandibular glands and in an immortalized murine cell line derived from salivary glands (SCA-9 cell line). For this purpose, total RNA was isolated from submandibular glands or cultured cells and submitted to reverse transcription. The cDNAs obtained were amplified by a nested polymerase chain reaction using preproglucagon primers. The results showed that the preproglucagon mRNA was expressed in adult rat submandibular glands but not in the SCA-9 cell line. Determination of cyclic DNA (cDNA) sequence established identity with the coding regions of rat pancreatic pre-proglucagon gene. In conclusion, these results strongly support the idea that rat submandibular glands could represent a source of extrapancreatic glucagon or of its precursor's peptide.

[Epidermal growth factor: a probable oral and digestive health protector]. / Le facteur de croissance épidermique: un gardien potentiel de la santé oro-digestive.

The integrity of oral and digestive mucosa depend on many salivary components like the Epidermal Growth Factor (EGF). Sometimes indicative, sometimes stimulated or modulated factor of oral and digestive health, EGF appears as a clinical marker in neoplastic and inflammatory diseases. As cellular growth factor, it protects the digestive mucosa with stimulation of mucus production and with inhibition of gastric secretion. Equally implicated in healing process, it enhances this one, and determines, in patients, more or less sensibility to inflammatory damages. Its strategic place in various pathologies, as stomach ulcer and tumoral process, open research prospects with a real potential of repair and pronostic.

TEM observations on the ameloblast/enamel interface in the rat incisor.

The structure of rat incisor enamel is established at the topographically complex interface between secretory ameloblasts and forming enamel. The aim of this study was to gain additional information on this interface by sectioning parallel with the rows and the long axis of Tomes' processes and prisms. Rats were sacrificed and fixed by glutaraldehyde/paraformaldehyde perfusion. After dissection, demineralization and embedding transverse jaw/incisor segments were cut, reembedded, and reoriented. Sections were prepared for and observed in the transmission electron microscopy (TEM). The intraenamel part of Tomes' process was about 18 microns long. The forming prism occupied a longitudinally grooved invagination on its apical aspect. The parts of Tomes' process forming the side walls of the groove were attenuated and showed variation in extent and outline. Prism growth occurred over the whole grooved area. An estimation of Tomes' process secretory area in rat compared with data from humans suggests that there may be a relationship between secretory area and rate of prism formation. Prism crystals were oriented obliquely or parallel to the secretory surface of Tomes' process. At interprism growth sites matrix deposition was irregular and required some redistribution to conform to the pattern of interprism sheets.

Relationship between dental occlusion and visual focusing.

The purpose of this study is to show the effects of dental occlusion on visual focusing. Thirty subjects were divided into two groups: an experimental group who had worn mandibular orthopedic repositioning appliances and a control group who had not worn any oral device. All of the subjects underwent the same visual focusing tests with a Maddox rod and the Berens prismatic bars, from over five meters to 30 centimeters. The results seemed to confirm that the alteration of dental occlusion can induce some fluctuations in visual focusing. The phenomenon occurs after wearing a MORA (Mandibular Orthopedic Repositioning Appliance) for a while. Feedback effects are gradual after removing the mandibular splint.

Vanadyl treatment normalizes submandibular salivary gland insulin-like immunoreactivity in streptozotocin-diabetic rats.

Rat submandibular salivary glands (SSG) contain a compound displaying insulin-like immunoreactivity (ILI) and various biological activities of insulin. As SSG ILI levels were reported to be increased in streptozotocin (STZ)-induced diabetes but not normalized by a two-week insulin treatment, we decided to check whether another antidiabetic treatment, vanadyl sulphate (VOSO4), was able to regulate SSG ILI concentration. A short term (8 days) i.p. VOSO4 treatment (total dose = 1.3 mmol/kg) of rats made diabetic 8 days earlier by a single i.v. injection of STZ (60 mg/kg BW) was able to induce a long-term (4 weeks) correction of hyperglycemia while weight gain was re-established. In untreated diabetic animals (approximately -25%) and increased (approximately +175%) as compared to normal rats. Both parameters were normalized in VOSO4-treated diabetic rats.

Age-dependent changes in insulin-like immunoreactivity in rat submandibular salivary glands.

In recent years, a growing interest had arisen in hormonal factors in salivary glands. We have investigated the changes in the content of an insulin-like immunoreactive (ILI) compound in the submandibular salivary glands of Sprague Dawley rats during physiological aging, in the range 15 days-27 months. The amount of ILI in the submandibular glands of young adult rats was found to be doubled in the post-natal period until the age of puberty and was maintained in senescence. No significant correlation was found between age-dependent variations in ILI levels of submandibular salivary glands and circulating insulin concentrations, further supporting previous indications that ILI is being synthesized in situ. It is possible that ILI could exert paracrine effects within the glands, as regards the development of other glandular structures during the first months of life, as well as the preservation of glandular function in senescent animals as well.

Biological activity of immunoreactive insulin-like activity extracted from rat submandibular gland.

Earlier studies indicate the presence of an insulin-like immunoreactivity (ILI) in rat submandibular salivary glands (SSG). Previous observations also showed that streptozotocin (STZ)-induced diabetes was accompanied by an increase in SSG ILI concentrations. In the present work we studied the effect of SSG ILI from normal and STZ diabetic rats (ILI-N and ILI-D, respectively) on insulin receptor binding and function in LMH cell line. ILI-N and ILI-D inhibited 125I-insulin binding to intact cells and wheat germ agglutinin (WGA)-purified insulin receptors with a high affinity. Furthermore, ILI-N and ILI-D activated, although weakly, the beta-subunit autophosphorylation of solubilized and WGA-purified insulin receptors. An ATP hydrolytic activity was present in ILI-N and, to a greater extent, in ILI-D extracts, which can at least in part explain their low potency for activating autophosphorylation and kinase activity of insulin receptors in vitro. However, after ILI treatment of intact cells and immunoprecipitation of insulin receptors, ILI induced a dose-dependent tyrosine phosphorylation of the insulin receptor beta-subunit. Finally, ILI-N and ILI-D stimulated amino acid uptake and lipogenesis in LMH cells. These findings suggest that SSG ILI is biologically active and can participate in metabolic regulations.

Maturation and insulin-like immunoreactivity in rat submandibular salivary glands: possible implication of G regulatory proteins.

Streptozotocin-induced diabetes is accompanied by an increase in insulin-like immunoreactivity concentration in rat submandibular salivary glands. In this study we have examined whether, in normal state, maturation is accompanied by changes in insulin-like immunoreactivity concentration of rat submandibular salivary glands. Insulin-like immunoreactivity concentrations of submandibular salivary glands were significantly higher in 11 months old rats compared with 3.5 months old control animals. A pertussis toxin pretreatment provoked an increase in insulin-like immunoreactivity, suggesting that a pertussis toxin sensitive G-protein is involved in the regulation of insulin-like immunoreactivity in the rat submandibular salivary glands.

Increases in concentrations of somatostatin- and insulin-like immunoreactivities in submandibular salivary gland of diabetic rats: effect of insulin treatment.

To investigate whether systemic insulin levels can influence somatostatin-like immunoreactivity and insulin-like immunoreactivity concentrations in the rat submandibular salivary glands, we measured the concentrations of the two peptides in an experimental group rendered diabetic by streptozotocin administration. The diabetic group showed a low plasma level of insulin compared with the control group: 0.5 +/- 0.1 vs 3.5 +/- 0.8 micrograms/l, (P less than 0.01). Concomitantly, they exhibited clear glucosuria and a blood glucose level which was four times higher than in normal animals: 35.5 +/- 1.4 vs 8.8 +/- 0.8 mmol/l, (P less than 0.001). The two peptide concentrations in the submandibular glands of diabetic rats showed an increase compared with controls: 42.9 +/- 4.7 protein vs 24.7 +/- 3.1 pg/mg protein (P less than 0.001) and 34.9 +/- 4.9 protein vs 18.4 +/- 4.0 pg/mg protein (P less than 0.01), for insulin-like immunoreactivity concentration and somatostatin-like immunoreactivity concentration, respectively. Chronic insulin treatment of diabetic rats reversed the increase in somatostatin, but had no effect on the increase in insulin-like immunoreactivity concentration. A negative correlation (r = 0.24, P less than 0.05) was found between the plasma insulin level and the somatostatin concentration of the submandibular glands. Our results suggest that the submandibular glands of rats may participate in the peripheral regulation of glucose homeostasis.

Somatostatin-immunoreactive concentrations in human saliva and in the submandibular salivary glands of the rat. Possible sexual dependence in the human.

Many biologically active polypeptides have been detected either in the submandibular salivary glands (SSG) of the rat, and in the saliva of rats and humans. The present work has investigated the case of somatostatin (SRIF), since salivary data concerning the presence of this peptide are scarce and contradictory. In a group of healthy volunteers, SRIF-immunoreactivity (SRIF-IR) was tested in samples of mixed saliva. Not all the subjects revealed presence of SRIF-IR in saliva. For men, 5 out of 9 were positive (x = 26.40 +/- 10.03 pg/ml), whereas for women only one out of 10 was positive (x = 96.40 pg/ml). SRIF-IR was also determined in male rat submandibular glands from control animals (26.1 +/- 6.3 pg/mg protein, n = 18) and from animals injected one hour before with an alpha 1-adrenergic secretagogue, phenylephrine (27.9 +/- 7.1 pg/mg protein, n = 6). The results show that SRIF-IR is not constantly present in human saliva obtained from a young population, and that its presence apparently seems to differ between the sexes. On the other hand, the fact that SRIF-IR, unlike other peptides, is not modified when the animals are injected with phenylephrine, may simply indicate that the control mechanism of SRIF-IR release is not the same as that affecting other salivary peptides. Further studies must be carried out in order to elucidate the origin and role of salivary SRIF-IR.

[Salivary hormones: a new aspect of oral physiology]. / Les hormones salivaires: un aspect nouveau de la physiologie orale.

Aside from the digestive enzymes the submandibular salivary glands (SSG) synthetize other polypeptides, detected also in saliva, with varied biological activity; NGF and EGF are the knowest. However, over the last decade, steroids hormones have been also found out in the saliva at the same concentrations that the free plasma fraction. The origin of these hormones is largely discussed and certain authors have even proposed a local synthesis for them. This matter, is of clinical interest because gingiva and buccal tissues are knowingly sensitive to steroids. Besides, woman ovulation appears to be monitored through progesterone fluctuations in saliva. Another kind of salivary substances is formed by the neuropeptides of the gut-brain axis, mainly VIP and SRIF. The former likely of nervous origin seems to be involved in the atropine-resistant salivary secretion, whereas the latter-likely of SSG origin--appears as a factor associated with glycemia control.

[Evaluation of an in vivo perfusion technic for the dental pulp in rats as validated by demonstration of the release of prostaglandins]. / Mise au point d'une technique de perfusion in vivo de la pulpe dentaire de rat validée par la mise en évidence de la libération de prostaglandines.

Many different biologically active substances contribute to the metabolism of dental pulp. Until now, release of these substances has been evaluated only by in vitro studies. The aim of this study was to establish a technique of perfusion allowing the evaluation in vivo of the secreting activity of dental pulp. In order to validate this technique, the in vivo release of prostaglandins, substances which seem to play a key role in pulpal metabolism was measured. The "push-pull" perfusion technique was used, whereby a physiological medium was made to bath the pulpal surface by aspiration. Pulp was exposed by opening an upper incisor in an anaesthetized rat. The perfusion was kept constant by means of a device composed of cannula, catheters, and micropumps which produced a flow followed by an aspiration of the liquid. Every ten minute fraction was analysed by high performance liquid chromatography. Ten minutes after the beginning of perfusion, the results showed a kinetic for PGE2 and PGF2 alpha release, characterized by a base level of 7.4 +/- 6.7 and 28.6 +/- 12.0 pg/min respectively. These were interrupted by a very high peak as compared to base level (19 times higher for PGE2 and 6.6 times for PGF2 alpha), occurring fifty minutes after trepanation. This experiment is the first attempt made in vivo and in situ, to measure biologically active substances of pulpal origin.