Tlx1 regulates acinar and duct development in mouse salivary glands.

Tlx1 encodes a transcription factor expressed in several craniofacial structures of developing mice. The role of Tlx1 in salivary gland development was examined using morphological and immunohistochemical analyses of Tlx1 null mice. Tlx1 is expressed in submandibular and sublingual glands but not parotid glands of neonatal and adult male and female C57Bl/6J (Tlx1 ) mice.

Odontoblast processes of the mouse incisor are plates oriented in the direction of growth.

Odontoblast processes are thin cytoplasmic projections that extend from the cell body at the periphery of the pulp toward the dentin-enamel junction. The odontoblast processes function in the secretion, assembly and mineralization of dentin during development, participate in mechanosensation, and aid in dentin repair in mature teeth. Because they are small and densely arranged, their three-dimensional organization is not well documented.

Expression of aquaporin 5 during murine palatine glands development: a light and electron microscopic immunocytochemical study.

Although aquaporin 5 (AQP5) seems to play a role in cytodifferentiation and cell proliferation during the development of salivary glands, its distribution during minor salivary glands development has been scarcely reported. This study examined the temporal-spatial distribution of AQP5 in the developing rat palatine glands using light and electron microscopy. At embryonic (E) age E18, AQP5 labeling was observed on the cell membranes of some terminal bulb cells.

Effects of spaceflight on the mouse submandibular gland.

Objective: This study was conducted to determine if the morphology and biochemistry of the mouse submandibular gland is affected by microgravity and the spaceflight environment.

Design: Tissues from female mice flown on the US space shuttle missions Space Transportation System (STS)-131 and STS-135 for 15 and 13 d, respectively, and from male mice flown on the 30 d Russian Bion-M1 biosatellite, were examined using transmission electron microscopy and light and electron microscopic immunohistochemistry.

Results: In contrast to the parotid gland, morphologic changes were not apparent in the submandibular gland.

Developmental Morphology of the Palatine Glands in Rats: An Electron Microscope Study.

Although minor salivary glands play a significant functional role in the oral cavity, their developmental morphology and cell differentiation has been scarcely studied. This study aimed to describe the development of rat palatine glands with regard to the ultrastructural morphology of the secretory cells and surrounding myoepithelial cells (MECs). Palatine glands from rats at embryonic ages (E) 18 and 20 days, and postnatal days (PN) 0, 3, 7, 10, 13, 21, 30, 42, and 60 were fixed and prepared for morphological analysis and immunocytochemical labeling of alpha-smooth muscle actin (α-SMA).

Response of the mouse sublingual gland to spaceflight.

The ultrastructure and immunohistochemistry of secretory proteins of sublingual glands were studied in mice flown on the US space shuttles Discovery [Space Transportation System (STS)-131] and Atlantis (STS-135). No differences in mucous acinar or serous demilune cell structure were observed between sublingual glands of ground (control) and flight mice. In contrast, previous studies showed autophagy and apoptosis of parotid serous acinar cells in flight mice.

Responses to spaceflight of mouse mandibular bone and teeth.

Objective: To determine if spaceflight and microgravity affect non-weight bearing bones and development and mineralization of teeth, reasoning that combining an organ and a cellular level approach can lead to greater insights about these effects.

Design: Mandibles and incisors of mice flown on the US STS-135 space shuttle mission and the Russian Bion-M1 satellite were studied using micro-computed tomography and immunohistochemistry. Ground controls were mice housed in standard vivarium cages and flight habitats.

Localization of cystic fibrosis transmembrane conductance regulator signaling complexes in human salivary gland striated duct cells.

The cystic fibrosis transmembrane conductance regulator (CFTR) is a cyclic AMP-dependent protein kinase (PKA)-regulated Cl(-) channel, crucial for epithelial cell regulation of salt and water transport. Previous studies showed that ezrin, an actin binding and A-kinase anchoring protein (AKAP), facilitates association of PKA with CFTR. We used immunohistochemistry and immunogold transmission electron microscopy to localize CFTR, ezrin, and PKA type II regulatory (RII) and catalytic (C) subunits in striated duct cells of human parotid and submandibular glands.

Redistribution of Gαs in mouse salivary glands following β-adrenergic stimulation.

Objective: Signalling via β-adrenergic receptors activates heterotrimeric G-proteins, which dissociate into α and βγ subunits. In salivary glands, the α subunit of Gs stimulates adenylate cyclase, increasing cyclic AMP levels and promoting exocytosis. The goals of this study were to determine Gαs localization in salivary glands and whether it undergoes redistribution upon activation.

Microgravity alters the expression of salivary proteins.

Spaceflight provides a unique opportunity to study how physiologic responses are influenced by the external environment. Microgravity has been shown to alter the function of a number of tissues and organ systems. Very little, however, is known about how microgravity affects the oral cavity.

Classification and volumetric analysis of temporal bone pneumatization using cone beam computed tomography.

Objective: This study performed volumetric analysis and classified different repeated patterns of temporal bone pneumatization in adults using cone beam computed tomography (CBCT) scans.

Study Design: A total of 155 temporal bones were retrospectively evaluated from 78 patients with no radiographic evidence of pathology. Two reference structures were used to classify temporal bone pneumatization into 3 groups.

Stacked endoplasmic reticulum sheets are connected by helicoidal membrane motifs.

The endoplasmic reticulum (ER) often forms stacked membrane sheets, an arrangement that is likely required to accommodate a maximum of membrane-bound polysomes for secretory protein synthesis. How sheets are stacked is unknown. Here, we used improved staining and automated ultrathin sectioning electron microscopy methods to analyze stacked ER sheets in neuronal cells and secretory salivary gland cells of mice.

The sld genetic defect: two intronic CA repeats promote insertion of the subsequent intron and mRNA decay.

The autosomal recessive mutation, sld, attenuates mucous cell expression in murine sublingual glands with corresponding effects on mucin 19 (Muc19). We conducted a systematic study including genetic mapping, sequencing, and functional analyses to elucidate a mutation to explain the sld phenotype in neonatal mice. Genetic mapping and gene expression analyses localized the sld mutation within the gene Muc19/Smgc, specifically attenuating Muc19 transcripts, and Muc19 knock-out mice mimic the sld phenotype in neonates.

Distribution of dendritic cells in normal human salivary glands.

Dendritic cells (DC) are believed to contribute to development of autoimmune sialadenitis, but little is known about their distribution in normal salivary glands. In this study, DC were identified and their distribution was determined in normal human parotid and submandibular glands. For light microscopy, salivary gland sections were stained with H&E or immunocytochemically using antibodies to DC markers.

Electron microscopic immunogold localization of salivary mucin MUC5B in human buccal and palatal glands.

In recent years, minor salivary glands, due to their involvement in the health and homeostasis of the oral cavity, have been the focus of several research investigations. Despite the fact that a considerable amount of data has been collected, many aspects of their functional features, including the secretory components they produce, remain to be ascertained. In this study we have analyzed the ultrastructural distribution of the MUC5B mucin in human palatal and buccal glands by means of post-embedding immunoelectron microscopy.

cPLA2 is protective against COX inhibitor-induced intestinal damage.

Cytosolic phospholipase A(2) (cPLA(2)) is the rate-limiting enzyme responsible for the generation of prostaglandins (PGs), which are bioactive lipids that play critical roles in maintaining gastrointestinal (GI) homeostasis. There has been a long-standing association between administration of cyclooxygenase (COX) inhibitors and GI toxicity. GI injury is thought to be induced by suppressed production of GI-protective PGs as well as direct injury to enterocytes.

Amylase and cyclic amp receptor protein expression in human diabetic parotid glands.

Background: Salivary dysfunction and oral disorders have been described in both type 1 and type 2 diabetes mellitus. However, the cellular and molecular consequences of diabetes on oral tissues remain to be ascertained. The purpose of this investigation was to study, by means of electron microscopy, the morphologic and molecular changes that occur in salivary glands during diabetes.

Ultrastructural localization of salivary mucins MUC5B and MUC7 in human labial glands.

As a result of their presence throughout the mouth in the submucosa or between muscle fibers, minor salivary glands secrete directly and continuously into the oral cavity, providing mucosal surfaces with highly glycosylated proteins that are active in bacterial aggregation and in oral tissue lubrication. In this study, we investigated the ultrastructural localization of the MUC5B and MUC7 mucins in human labial glands by means of a postembedding immunogold technique. Thin sections of normal human labial glands, obtained during surgery, were incubated with polyclonal antibodies to human salivary mucins MUC5B and MUC7, and then with gold-labeled secondary antibodies.

Secretory proteins in the saliva of children.

The protein composition of oral fluid is modulated by environmental factors and physiological states, i.e. chemical, mechanical and pharmacologic stimuli, pathologic conditions, and psychological stress.

The structure of tight junctions in mouse submandibular gland.

Salivary gland cells are joined by junctional complexes consisting of a tight junction (TJ), zonula adherens and one or more desmosomes. TJs regulate paracellular permeability, maintain separate apical and basolateral membrane domains, and serve as signaling centers. We examined TJs of mouse submandibular glands (SMG) in thin sections and freeze-fracture replicas.

Tissue distibution of murine Muc19/smgc gene products.

The recently identified gene Muc19/Smgc encodes two diverse splice variants, Smgc (submandibular gland protein C) and Muc19 (mucin 19). Muc19 is a member of the large gel-forming mucin family and is an exocrine product of sublingual mucous salivary glands in mice. SMGC is a transiently expressed secretion product of developing rodent submandibular and sublingual glands.

Protein expression in salivary glands of rats with streptozotocin diabetes.

Diabetes mellitus (DM) is a widespread disease with high morbidity and health care costs. An experimental animal model was employed, using morphological and biochemical methods, to investigate the effects of DM on the expression and compartmentation of salivary gland proteins. The distribution of proline-rich proteins (PRP), submandibular mucin (Muc10) and the regulatory (RI and RII) subunits of cyclic AMP-dependent protein kinase type I and type II was determined in the parotid and submandibular (SMG) glands of rats treated with streptozotocin.

RANBP2 is an allosteric activator of the conventional kinesin-1 motor protein, KIF5B, in a minimal cell-free system.

The association of cargoes to kinesins is thought to promote kinesin activation, yet the validation of such a model with native cargoes is lacking because none is known to activate kinesins directly in an in vitro system of purified components. The RAN-binding protein 2 (RANBP2), through its kinesin-binding domain (KBD), associates in vivo with kinesin-1, KIF5B/KIF5C. Here, we show that KBD and its flanking domains, RAN GTPase-binding domains 2 and 3 (RBD2/RBD3), activate the ATPase activity of KIF5B approximately 30-fold in the presence of microtubules and ATP.

Proteomic analysis of human parotid gland exosomes by multidimensional protein identification technology (MudPIT).

Human ductal saliva contributes over a thousand unique proteins to whole oral fluids. The mechanism by which most of these proteins are secreted by salivary glands remains to be determined. The present study used a mass spectrometry-based, shotgun proteomics approach to explore the possibility that a subset of the proteins found in saliva are derived from exosomes, membrane-bound vesicles of endosomal origin within multivesicular endosomes.