Measurement of Oral Moisture on Oral Dryness Patients.

Many elderly patients have oral dryness; thus, it is necessary to evaluate the oral moisture in a clinical setting. The aim of this study was to clarify the importance of controlling the measuring pressure of the oral moisture-checking device. The influence of the measuring pressure of the oral moisture-checking device was examined using agar under 10 measuring pressure conditions (Kruskal-Wallis test).

Analysis of salivary factors related to the oral health status in children.

Early detection of oral disease is important to reduce its severity and increase the likelihood of successful treatment. This study aimed to perform a quantitative assessment of the saliva components as a first stage of the research to screen oral homeostasis. Here, saliva secretions collected from children were evaluated, and their constituents were analyzed to investigate the potential correlations between the buffering capacity and a range of salivary factors.

The Role of Genetic Factors in the Outbreak Mechanism of Dental Caries.

Objective: The aim of the present study was to investigate the relationships between cariogenic bacterial infection and single nucleotide polymorphisms (SNPs) in candidate genes associated with dental caries, and to explore the factors related to caries in children.

Study Design: Children aged 3 to 11 years were selected. Detection of cariogenic bacteria (Streptococcus mutans, Streptococcus oralis, Streptococcus sobrinus and Lactobacillus) from the plaque of each patient, and SNP analyses of five candidate genes (MBL2, TAS2R38, GLUT2, MMP13 and CA6) were performed using DNA isolated from buccal mucosal cells.

Characterization of cysteine string protein in rat parotid acinar cells.

Cysteine string proteins (CSPs) are secretory vesicle chaperone proteins that contain: (i) a heavily palmitoylated cysteine string (comprised of 14 cysteine residues, responsible for the localization of CSP to secretory vesicle membranes), (ii) an N-terminal J-domain (DnaJ domain of Hsc70, 70kDa heat-shock cognate protein family of co-chaperones), and (iii) a linker domain (important in mediating CSP effects on secretion). In this study, we investigated the localization of CSP1 in rat parotid acinar cells and evaluated the role of CSP1 in parotid secretion. RT-PCR and western blotting revealed that CSP1 was expressed and associated with Hsc70 in rat parotid acinar cells.

Atrophy of myoepithelial cells in parotid glands of diabetic mice; detection using skeletal muscle actin, a novel marker.

In mouse parotid glands, we found expression of skeletal muscle actin (actin-α1) protein and mRNA. We isolated myoepithelial cells from the mouse parotid glands and investigated their actin-α1 expression because smooth muscle actin (actin-α2) has been used as a marker for myoepithelial cells. We used actin-α1 expression to identify pathological changes in diabetic non-obese diabetic (NOD; NOD/ShiJcl) mice-a mouse model for Sjögren's syndrome-and found myoepithelial cells to be decreased or atrophied in the diabetic state.

MADD/DENN/Rab3GEP functions as a guanine nucleotide exchange factor for Rab27 during granule exocytosis of rat parotid acinar cells.

We previously reported that the small GTPase Rab27 and its effectors regulate isoproterenol (IPR)-stimulated amylase release from rat parotid acinar cells. Although activation of Rab27 by a specific guanine nucleotide exchange factor (GEF) is thought to be required for amylase release, its activation mechanism is poorly understood, because GEF for Rab27 has not been reported in parotid acinar cells. In the present study, we investigated the possible involvement of MADD/DENN/Rab3GEP, which was recently described as a Rab27-GEF in melanocytes, in amylase release from rat parotid acinar cells.

Antigen-presenting cells in parotid glands contain cystatin D originating from acinar cells.

Cystatin D encoded by Cst5 is a salivary classified type II cystatin. We investigated the dynamism of cystatin D by examining the distribution of cystatin D protein and mRNA in rats, to identify novel functions. The simultaneous expression of Cst5 and cystatin D was observed in parotid glands, however in situ hybridization showed that only acinar cells produced cystatin D.

Exocyst subunits are involved in isoproterenol-induced amylase release from rat parotid acinar cells.

Exocytosis of secretory granules in parotid acinar cells requires multiple events: tethering, docking, priming, and fusion with a luminal plasma membrane. The exocyst complex, which is composed of eight subunits (Sec3, Sec5, Sec6, Sec8, Sec10, Sec15, Exo70, and Exo84) that are conserved in yeast and mammalian cells, is thought to participate in the exocytotic pathway. However, to date, no exocyst subunit has been identified in salivary glands.

EPI64 protein functions as a physiological GTPase-activating protein for Rab27 protein and regulates amylase release in rat parotid acinar cells.

Rab27, a small GTPase, is generally recognized as an important regulator of secretion that interacts with Rab27-specific effectors to regulate events in a wide variety of cells, including endocrine and exocrine cells. However, the mechanisms governing the spatio-temporal regulation of GTPase activity of Rab27 are not firmly established, and no GTPase-activating protein (GAP) specific for Rab27 has been identified in secretory cells. We previously showed that expression of EPI64, a Tre-2/Bub2/Cdc16 (TBC)-domain-containing protein, in melanocytes inactivates endogenous Rab27A on melanosomes (Itoh, T.

Gene expression profiles of the three major salivary glands in rats.

The protein components of saliva reflect the condition of the whole body as well as the salivary glands. The aim of this study is to characterize the gene expression profiles in each of the rat major salivary glands-the parotid, submandibular, and sublingual glands. Gene expression was analyzed using DNA microarrays, and observed differences in expression of representative genes were confirmed by quantitative, real-time polymerase chain reaction.

Evidence for amylase release by cyclin-dependent kinase 5 in the rat parotid.

Cyclin-dependent kinase 5 (Cdk5) plays no apparent role in cell cycle regulation, and Cdk5 is not activated by cyclins but only p35 or p39. Although the enzymatic activity of Cdk5 is highest in the central nervous system, recent reports indicate that it also has important functions in non-neuronal cells. In the present study, we investigated whether Cdk5 and its activators are expressed in rat parotid acinar cells, whether a β-adrenergic agonist enhances the expression of Cdk5, and whether Cdk5 mediates amylase release.

Redistribution of small GTP-binding protein, Rab27B, in rat parotid acinar cells after stimulation with isoproterenol.

Small GTP-binding protein, Rab27, has been implicated in the regulation of different types of membrane trafficking, including melanosome transport in melanocytes and regulated secretion events in a wide variety of secretory cells. We have previously shown that Rab27 is involved in the control of isoproterenol (IPR)-induced amylase release from rat parotid acinar cells. Although Rab27 is predominantly localized on secretory granules under resting conditions, changes to its intracellular localization after beta-stimulation have never been elucidated.

Transferrin secretory pathways in rat parotid acinar cells.

Transferrin is the major iron transporter in blood plasma, and is also found, at lower concentrations, in saliva. We studied the synthesis and secretion of transferrin in rat parotid acinar cells in order to elucidate its secretory pathways. Two sources were identified for transferrin in parotid acinar cells: synthesis by the cells (endogenous), and absorption from blood plasma (exogenous).

Redistribution of Rab27-specific effector Slac2-c, but not Slp4-a, after isoproterenol-stimulation in rat parotid acinar cells.

Small GTPase Rab27 has been implicated in the regulation of different types of membrane trafficking, including melanosome transport and various regulated secretion events. We have previously shown that Rab27 and its effectors, Slac2-c/MyRIP and Slp4-a/granuphilin-a, are involved in the control of isoproterenol (IPR)-induced amylase release from rat parotid acinar cells. The ability of Rab to interact with the specific effectors is important.

Unstimulated amylase secretion is proteoglycan-dependent in rat parotid acinar cells.

It is well-known that amylase is secreted in response to extracellular stimulation from the acinar cells. However, amylase is also secreted without stimulation. We distinguished vesicular amylase as a newly synthesized amylase from the accumulated amylase in secretory granules by short time pulse and chased with (35)S-amino acid.

Evidence for amylase release by cGMP via cAMP-dependent protein kinase in rat parotid acinar cells.

Amylase release from the rat parotid gland is primarily mediated by a cAMP-dependent protein kinase (PKA). We previously reported that cGMP/cGMP-dependent protein kinase (PKG) signaling evokes amylase release. In the present study, we investigated whether cGMP-mediated amylase release might be due to cGMP/PKA signaling, as well as cGMP/PKG pathway.

Functional involvement of Noc2, a Rab27 effector, in rat parotid acinar cells.

Noc2 has recently been proposed to regulate exocytosis in both endocrine and exocrine cells; however, protein expression, subcellular localization and function of Noc2 in exocrine cells have never been elucidated. In this study, we investigated whether Noc2, a Rab27 effector, is involved in isoproterenol (IPR)-stimulated amylase release from acinar cells. Rab27 was detected in the apical plasma membrane (APM) and secretory granule membrane (SGM) fractions, and was translocated to the APM after IPR stimulation for 5 min, but was detected at lower levels in the APM after 30 min.

Slp4-a/granuphilin-a interacts with syntaxin-2/3 in a Munc18-2-dependent manner.

Slp4-a/granuphilin-a was originally described as a protein specifically associated with insulin-containing granules in pancreatic beta-cells, but it was subsequently found to be present on amylase-containing granules in parotid acinar cells. Although Slp4-a has been suggested to control insulin secretion through interaction with syntaxin-1a and/or Munc18-1, nothing is known about the binding partner(s) of Slp4-a during amylase release from parotid acinar cells, which do not endogenously express either syntaxin-1a or Munc18-1. In this study we systematically investigated the interaction between syntaxin-1-5 and Munc18-1-3 by co-immunoprecipitation assay using COS-7 cells and discovered that Slp4-a interacts with a closed conformation of syntaxin-2/3 in a Munc18-2-dependent manner, whereas Munc18-2 itself hardly interacts with Slp4-a at all.

Relation of Rab26 to the amylase release from rat parotid acinar cells.

Amylase secretion from rat parotid acinar cells is induced by the accumulation of cAMP in response to beta-adrenergic agonists as well as by the elevation of intracellular Ca2+ in response to muscarinic cholinergic stimulation. Several proteins including the low molecular weight GTP-binding protein Rab may participate in these exocytic processes. In the current studies, we investigated the role of Rab26 in the process of amylase secretion.

Stimulation of guanylate cyclase in rat parotid membranes by phosphate.

The natriuretic peptide receptor guanylate cyclases are members of the membrane-bound guanylate cyclase family. Atrial natriuretic pepticle (ANP) stimulates guanylate cyclase A, which is predominantly expressed in the rat parotid gland. ATP is well known to increase ANP-stimulated guanylate cyclase, with Mg2+ as a cofactor.

Presence of cytoskeleton proteins in parotid glands and their roles during secretion.

Amylase secretion is induced by the accumulation of cAMP in response to beta-adrenergic stimulation and by the augmentation of intracellular Ca2+ in response to muscarinic-cholinergic stimulation in rat parotid glands. The roles of cytoskeleton and motor proteins in the secretory process are not yet known. We examined the effects of cytoskeleton-modulating reagents on the amylase release induced by isoproterenol (IPR) and carbamylcholine (Cch) in rat parotid acinar cells.

Evidence for the involvement of cAMP-GEF (Epac) pathway in amylase release from the rat parotid gland.

Amylase release from the rat parotid gland is mainly mediated in a cAMP-dependent protein kinase (PKA)-dependent manner. In the present study, amylase release mediated in cAMP-dependent and PKA-independent manners was investigated with a cAMP-regulated guanine nucleotide exchange factor (cAMP-GEF: Epac)-selective cAMP analogue, 8CPT-2Me-cAMP. The Epac was localized in the intracellular and the plasma membrane fractions.

Soluble guanylyl cyclase is localised in the acinar cells and participates in amylase secretion in rat parotid gland.

It is well known that the muscarinic cholinergic agonists, carbachol and methacholine, enhance nitric oxide synthase (NOS) activity, and also stimulate salivary secretion. In the present study, we investigated whether salivary secretion by muscarinic cholinergic stimulation is mediated through the NO/cGMP signaling pathway in rat salivary glands. Since NO activates soluble guanylyl cyclase (sGC) and cGMP may function as a mediator, the localisation of sGC was investigated in the salivary glands.

The small GTPase Rab27B regulates amylase release from rat parotid acinar cells.

Small GTPase Rab is a large family of putative membrane trafficking proteins, and each member is thought to regulate a specific type(s) of membrane trafficking. However, little is known about the involvement of Rab protein(s) in secretory granule exocytosis in exocrine cells or the molecular mechanism underlying this process. We show that Rab27B, a closely related isoform of Rab27A that regulates lysosome-related granule exocytosis in cytotoxic T lymphocytes, is abundantly expressed on amylase-containing secretory granules in rat parotid gland acinar cells.