Identification of differentially expressed genes in primary Sjögren's syndrome

Primary Sjögren's syndrome (pSS) is a chronic systemic autoimmune disease that affects exocrine glands. To study the molecular mechanism and identify crucial genes/pathways in pSS pathogenesis, the microarray-based whole-genome gene expression profiles from salivary glands of patients with pSS and non-sicca controls were retrieved. After normalization and subsequent batch effect adjustment, significance analysis of microarrays method was applied to five available datasets, and 379 differentially expressed genes (DEGs) were identified. The 300 upregulated DEGs were enriched in Gene Ontology terms of immune and inflammatory responses, including antigen processing and presentation, interferon-mediated signaling pathway, and chemotaxis. Previously reported pSS-associated genes, including HLA-DRA, TAP2, PRDM1, and IFI16, were found to be significantly upregulated. The downregulated DEGs were enriched in pathways of salivary secretion, carbohydrate digestion and absorption, and starch and sucrose metabolism, implying dysfunction of salivary glands during pathogenesis. Next, a protein-protein interaction network was constructed, and B2M, an upregulated DEG, was shown to be a hub, suggesting its potential involvement in pSS development. In summary, we found the activation of pSS-associated genes in pathogenesis, and provide clues for salivary glands dysfunction. Experimental investigation on the identified DEGs in this study will deepen our understanding on pSS.     

Light and electron microscopy studies of the midgut and salivary glands of second and third instars of the horse stomach bot,Gasterophilus intestinalis

A morphological study of the midgut and salivary glands of second and third instars of Gasterophilus intestinalis (De Geer) (Diptera: Oestridae) was conducted by light, scanning and transmission electron microscopy. The midgut is anteriorly delimited by a proventriculus, without caeca, and is composed of posterior foregut and anterior midgut tissue from which a double‐layered peritrophic matrix is produced. The midgut can be divided into anterior, median and posterior regions on the basis of the structural and physiological variations of the columnar cells which occur along its length. Two other types of cell were identified: regenerative cells scattered throughout the columnar cells, and, more rarely, endocrine cells of two structural types (closed and open). Different secretion mechanisms (merocrine, apocrine and microapocrine) occur along the midgut epithelium. Abundant microorganisms are observed in the endoperitrophic space of the anterior midgut. The origin and nature of these microorganisms remain unknown. No structural differences are observed between the second and third instar midguts. The salivary glands of G. intestinalis second and third instars consist of a pair of elongated tubular structures connected to efferent ducts which unite to form a single deferent duct linked dorsally to the pharynx. Several intermediate cells, without cuticle, make the junction with the salivary gland epithelium layer. Cytological characteristics of the gland epithelial cells demonstrate high cellular activity and some structural variations are noticed between the two larval stages.     

Bicarbonate and chloride secretion in Calu-3 human airway epithelial cells

Serous cells are the predominant site of cystic fibrosis transmembrane conductance regulator expression in the airways, and they make a significant contribution to the volume, composition, and consistency of the submucosal gland secretions. We have employed the human airway serous cell line Calu-3 as a model system to investigate the mechanisms of serous cell anion secretion. Forskolin-stimulated Calu-3 cells secrete HCO-3 by a Cl-offdependent, serosal Na+-dependent, serosal bumetanide-insensitive, and serosal 4,4'-dinitrostilben-2,2'-disulfonic acid (DNDS)-sensitive, electrogenic mechanism as judged by transepithelial currents, isotopic fluxes, and the results of ion substitution, pharmacology, and pH studies. Similar studies revealed that stimulation of Calu-3 cells with 1-ethyl-2-benzimidazolinone (1-EBIO), an activator of basolateral membrane Ca2+-activated K+ channels, reduced HCO-3 secretion and caused the secretion of Cl- by a bumetanide-sensitive, electrogenic mechanism. Nystatin permeabilization of Calu-3 monolayers demonstrated 1-EBIO activated a charybdotoxin- and clotrimazole- inhibited basolateral membrane K+ current. Patch-clamp studies confirmed the presence of an intermediate conductance inwardly rectified K+ channel with this pharmacological profile. We propose that hyperpolarization of the basolateral membrane voltage elicits a switch from HCO-3 secretion to Cl- secretion because the uptake of HCO-3 across the basolateral membrane is mediated by a 4,4 '-dinitrostilben-2,2'-disulfonic acid (DNDS)-sensitive Na+:HCO-3 cotransporter. Since the stoichiometry reported for Na+:HCO-3 cotransport is 1:2 or 1:3, hyperpolarization of the basolateral membrane potential by 1-EBIO would inhibit HCO-3 entry and favor the secretion of Cl-. Therefore, differential regulation of the basolateral membrane K+ conductance by secretory agonists could provide a means of stimulating HCO-3 and Cl- secretion. In this context, cystic fibrosis transmembrane conductance regulator could serve as both a HCO-3 and a Cl- channel, mediating the apical membrane exit of either anion depending on basolateral membrane anion entry mechanisms and the driving forces that prevail. If these results with Calu-3 cells accurately reflect the transport properties of native submucosal gland serous cells, then HCO-3 secretion in the human airways warrants greater attention.     

How much pilocarpine contaminates pilocarpine‐induced tick saliva?

Pilocarpine is often applied or injected into ticks to induce salivation, and the resulting saliva used to test for various pharmacological, biochemical and immunological activities. To measure the amount of pilocarpine in pilocarpine-induced tick saliva, an HPLC-MS/MS method, based on capillary strong cation exchange chromatography online with an ion trap mass spectrometer, was used to measure pilocarpine in the pg to ng range. Results indicate large concentrations of pilocarpine in Ixodes scapularis Say and Amblyomma americanum (Linnaeus) (Acari: Ixodidae) saliva, ranging from 3 to 50 mm. Due to the known effects of pilocarpine on smooth muscle and immune cells, appropriate controls are proposed and discussed for proper interpretation of results using this saliva preparation.     

Anogenital gland secretions of Lemur catta and Propithecus verreauxi coquereli: a preliminary chemical examination

Although prosimians are greatly olfaction-oriented, little is known about the specifics of how they use scent to communicate. In this preliminary study we attempted to delineate intra- and interspecific differences among the anogenital gland secretions of two lemur species (Lemur catta and Propithecus verreauxi coquereli) using gas chromatography-mass spectrometry (GC-MS). The results indicate that the two species are discernible through scent. Furthermore, we were able to identify reproductive status using this technique. The anogenital secretions of the different sexes in L. catta, though perhaps not P. v. coquereli, are chemically distinguishable. Given this information, it appears that at least some lemur species can use scent marks to determine species, sex, and reproductive status.     

A stingless bee uses labial gland secretions for scent trail communication (<Emphasis Type="Italic">Trigona recursa</Emphasis> Smith 1863)

The pheromones used by several species of stingless bees for scent trail communication are generally assumed to be produced by the mandibular glands. Here we present strong evidence that in Trigona recursa these pheromones originate from the labial glands, which are well developed in the heads of foragers. Analysis of the behavior involved in scent marking shows that a bee extends her proboscis and rubs it over the substrate. A single scent marking event lasts for 0.59±0.21 s while the bee runs a stretch of 1.04±0.37 cm on a leaf. According to choice experiments the bees are attracted by a feeder baited with labial gland extract (84.2±6% of the bees choose this feeder) but repelled from a feeder baited with mandibular gland extract (only 27.5±13.1% of the bees choose this feeder). They do not discriminate between two clean feeders (49.6±3% of the bees at a feeder). 87±5.1% of bees already feeding leave the feeder after the application of mandibular gland extract whereas only 6.2±4.9% and 2.6±4% do so when labial gland extract or pure solvent was applied.     

Ultrastructure and histochemistry of the foregut in<Emphasis Type="Italic"> Wirenia argentea</Emphasis> and<Emphasis Type="Italic"> Genitoconia rosea</Emphasis> (Mollusca,Solenogastres)

Wirenia argentea and Genitoconia rosea feed on Cnidaria like most representatives of the molluscan taxon Solenogastres (Aplacophora, Neomeniomorpha sensu Scheltema). The structure and histochemistry of the foregut are described based on histologic, semithin, and ultrathin section series. The ultrastructure was analyzed by means of transmission electron microscopy. There are two sets of unicellular glands: a narrow row of preoral gland cells opening to the preoral area, and pharyngeal gland cells in high numbers. Preoral gland cells produce serous secretions in W. argentea, but mucosubstances in G. rosea, whereas pharyngeal gland cells are similar in structure and histochemistry in both species. Based on the size and electron density of gland vesicles, five distinct types of pharyngeal gland cells can be defined. In contrast to earlier assumptions, all types of pharyngeal gland cells produce serous secretions, most probably representing digestive ferments, but no mucosubstances.     

Ultrastructural cytochemistry of the sex pheromone glands of Lutzomyia cruzi male sand flies (Diptera: Psychodidae: Phlebotominae)

The sex pheromone glands of Lutzomyia cruzi male sand flies (Diptera: Psychodidae) were analyzed by cytochemical techniques. In adult males, the epithelium at the fourth abdominal tergite is modified into a glandular epithelium, with large columnar gland cells located side by side. The gland cell cytoplasm contains a large number of mitochondria and peroxisomes, the latter with positive (electron-dense) reaction for catalase, a typical peroxisomal enzyme marker. The gland cell cytoplasm also contains a central vacuolated area, with a large number of electron-lucent vacuoles, not limited by a unit membrane. In well-preserved preparations such vacuoles present a homogenous and slightly electron-dense content, typical of lipid droplets. Indeed, incubation of the tergites with imidazole-buffered osmium tetroxide (to detect lipids) resulted in positive reaction in these vacuoles, as well as in between the microvilli of the gland cells. Use of the osmium–potassium iodide (Os–KI) technique allowed to demonstrate the presence of several endoplasmic reticulum (ER) profiles, as expected in secretory cells. Our data suggest that ER, lipid droplets and peroxisomes are involved in the sand fly pheromone biosynthesis.