Orientia tsutsugamushi, a causative pathogen of Scrub typhus, is a gram-negative intracellular bacterium. Outer membrane vesicles (OMVs) are produced from the membrane of bacteria and play many roles related to the survival of the pathogen. However, there have been no reports confirming whether O. tsutsugamushi indeed produce OMVs. O. tsutsugamushi boryong was cultured in ECV-304 cells for the purification of OMVs. Western blot analysis and immunoenrichment using anti-O. tsutsugamushi monoclonal antibody and electron microscopy were employed for identification and characterization of OMVs. We confirm the presence of OMVs derived from O. tsutsugamushi, and also found that those OMVs contain a major surface antigen of 56-kDa protein and variant immunogenic antigens.
Antibodies, Monoclonal/*immunology ; Antigens, Bacterial/*immunology ; Antigens, Surface/*immunology ; Cell Line ; Cell Membrane/immunology ; Humans ; Microscopy, Electron ; Orientia tsutsugamushi/*immunology/metabolism ; Scrub Typhus/diagnosis/microbiology ; Secretory Vesicles/*immunology

Levofloxacin, a fluoroquinolone and L-isomer of the racemate ofloxacin, has been approved for the treatment of acute and chronic bacterial infections. Gastrointestinal complaints are the most frequently reported adverse drug reactions to fluoroquinolones. Other adverse events include headache, dizziness, increased liver enzyme levels, photosensitivity, tachycardia, QT prolongation, and eruptions. Anaphylaxis has been documented as a rare adverse drug reaction to levofloxacin; however, diagnostic tests are needed to evaluate whether these reactions are the result of levofloxacin treatment. While the results of skin tests are considered unreliable due to false-positive responses, the oral provocation test is currently considered to be the most reliable test. Tryptase, a neutral protease, is the dominant protein component of secretory granules in human mast cells, and an increased serum concentration of tryptase is a highly sensitive indicator of anaphylaxis. Herein, we report a case of levofloxacin-induced anaphylaxis in which the patient exhibited elevated serum tryptase levels and a positive oral levofloxacin challenge test result. As anaphylaxis is potentially life-threatening, the administration of fluoroquinolones to patients who have experienced a prior reaction to this type of agent should be avoided.
Anaphylaxis ; Bacterial Infections ; Diagnostic Tests, Routine ; Dizziness ; Drug Hypersensitivity ; Drug Toxicity ; Fluoroquinolones ; Headache ; Humans ; Liver ; Mast Cells ; Ofloxacin ; Secretory Vesicles ; Skin Tests ; Tachycardia ; Tryptases

Catecholamine secretory traits were significantly heritable, as were stress-induced blood pressure changes. Tyrosine hydroxylase (TH) is the rate-limiting enzyme in catecholamine biosynthesis. In the tyrosine hyroxylase promoter, significant associations were found for urinary catecholamine excretion and for blood pressure response to stress. TH promoter haplotype 2 (TGGG) showed pleiotropy, increasing both norepinephrine excretion and blood pressure during stress. In hypertension, 2 independent case-control studies (1,266 subjects with 53% women and 927 subjects with 24% women) replicated the effect of C-824T in the determination of blood pressure. Chromogranin A (CHGA) plays a fundamental role in the biogenesis of catecholamine secretory granules. Changes in the storage and release of CHGA in clinical and experimental hypertension prompted us to study whether genetic variation at the CHGA locus might contribute to alterations in autonomic function, and hence hypertension and its target organ consequences such as hypertensive kidney disease (nephrosclerosis). Systematic polymorphism discovery across the human CHGA locus revealed such regulatory regions as the proximal promoter and 3'-UTR. In chromaffin cell-transfected CHGA 3'-UTR and promoter/luciferase reporter plasmids, the functional consequences of the regulatory/non-coding allelic variants were documented. Variants in both the proximal promoter and the 3'-UTR displayed statistical associations with hypertension and hypertensive end stage renal disease. Therefore, I would like to review the common genetic variation in TH and CHGA as a cause of inter-individual variation in sympathetic activity, and ultimately blood pressure and hypertensive kidney disease.
Blood Pressure ; Case-Control Studies ; Chromogranin A ; Female ; Genetic Variation ; Genomics ; Haplotypes ; Humans ; Hypertension ; Kidney ; Kidney Diseases ; Kidney Failure, Chronic ; Norepinephrine ; Plasmids ; Regulatory Sequences, Nucleic Acid ; Secretory Vesicles ; Tyrosine ; Tyrosine 3-Monooxygenase ; Organelle Biogenesis

Botulinum toxin A (BTXA) has been used in several clinical trials to treat excessive glandular secretion; however, the precise mechanism of its action on the secretory function of salivary gland has not been fully elucidated. In this study, we aimed to investigate the effect of BTXA on secretion of submandibular gland in rabbits and to identify its mechanism of action on the secretory function of salivary gland. At 12 weeks after injection with 5 units of BTXA, we found a significant decrease in the saliva flow from submandibular glands, while the salivary amylase concentration increased. Morphological analysis revealed reduction in the size of acinar cells with intracellular accumulation of secretory granules that coalesced to form a large ovoid structure. Expression of M3-muscarinic acetylcholine receptor (M3 receptor) and aquaporin-5 (AQP5) mRNA decreased after BTXA treatment, and distribution of AQP5 in the apical membrane was reduced at 1, 2 and 4 weeks after BTXA injection. Furthermore, BTXA injection was found to induce apoptosis of acini. These results indicate that BTXA decreases the fluid secretion of submandibular glands and increases the concentration of amylase in saliva. Decreased expression of M3 receptor and AQP5, inhibition of AQP5 translocation, and cell apoptosis might involve in BTXA-reduced fluid secretion of submandibular glands.
Amylases ; drug effects ; Animals ; Apoptosis ; drug effects ; Aquaporin 5 ; antagonists & inhibitors ; Botulinum Toxins, Type A ; pharmacology ; Cell Membrane ; drug effects ; In Situ Nick-End Labeling ; Male ; Microscopy, Electron, Transmission ; Neuromuscular Agents ; pharmacology ; Organ Size ; Rabbits ; Random Allocation ; Receptor, Muscarinic M3 ; antagonists & inhibitors ; Saliva ; drug effects ; secretion ; Salivary Proteins and Peptides ; drug effects ; Salivation ; drug effects ; Secretory Rate ; drug effects ; Secretory Vesicles ; drug effects ; Submandibular Gland ; drug effects ; pathology ; secretion ; Time Factors

Mucin secretion in the airway epithelium acts as an essential barrier process that protects the upper respiratory tract from inhaled particles, environmental pathogens and toxicants. However, dysregulated mucin secretion contributes to pathophysiologic conditions such as rhinitis, asthma, and chronic obstructive pulmonary disease etc. The study on mucin hypersecretion has long been worked, but the exact molecular composition and mechanism for exocytic machinery remain mostly to be elucidated. The regulated mucin secretion, highly coordinated process, is mediated by the cooperative interaction of several proteins existing in the secretory granule, cytoplasm, and plasma membrane. This review provides the information on molecular components of the core exocytic machinery and their functional roles for mucin exocytosis in airway secretory cells.
Asthma ; Cell Membrane ; Cytoplasm ; Epithelium ; Exocytosis ; Mucins ; Proteins ; Pulmonary Disease, Chronic Obstructive ; Respiratory System ; Rhinitis ; Secretory Vesicles

Animals ; Biomarkers ; blood ; cerebrospinal fluid ; metabolism ; Brain ; metabolism ; Cell Line ; Cell Movement ; Central Nervous System ; metabolism ; Exocytosis ; Humans ; Mice ; MicroRNAs ; blood ; cerebrospinal fluid ; metabolism ; Secretory Vesicles ; metabolism

A major advance in the understanding of the regulation of food intake has been the discovery of the adipokine leptin a hormone secreted by the adipose tissue. After crossing the blood-brain barrier, leptin reaches its main site of action at the level of the hypothalamic cells where it plays fundamental roles in the control of appetite and in the regulation of energy expenditure. At first considered as a hormone specific to the white adipose tissue, it was rapidly found to be expressed by other tissues. Among these, the gastric mucosa has been demonstrated to secrete large amounts of leptin. Secretion of leptin by the gastric chief cells was found to be an exocrine secretion. Leptin is secreted towards the gastric lumen into the gastric juice. We found that while secretion of leptin by the white adipose tissue is constitutive, secretion by the gastric cells is a regulated one responding very rapidly to secretory stimuli such as food intake. Exocrine-secreted leptin survives the hydrolytic conditions of the gastric juice by forming a complex with its soluble receptor. This soluble receptor is synthesized by the gastric cells and the leptin-leptin receptor complex gets formed at the level of the gastric chief cell secretory granules before being released into the gastric lumen. The leptin-leptin receptor upon resisting the hydrolytic conditions of the gastric juice is channelled, to the duodenum. Transmembrane leptin receptors expressed at the luminal membrane of the duodenal enterocytes interact with the luminal leptin. Leptin is actively transcytosed by the duodenal enterocytes. From the apical membrane it is transferred to the Golgi apparatus where it binds again its soluble receptor. The newly formed leptin-leptin receptor complex is then secreted baso-laterally into the intestinal mucosa to reach the blood capillaries and circulation thus reaching the hypothalamus where its action regulates food intake. Exocrine-secreted gastric leptin participates in the short term regulation of food intake independently from that secreted by the adipose tissue. Adipose tissue leptin on the other hand, regulates in the long term energy storage. Both tissues work in tandem to ensure management of food intake and energy expenditure.
Adipokines ; Adipose Tissue ; Adipose Tissue, White ; Appetite ; Blood-Brain Barrier ; Capillaries ; Chief Cells, Gastric ; Dietary Sucrose ; Duodenum ; Eating ; Energy Metabolism ; Enterocytes ; Gastric Juice ; Gastric Mucosa ; Golgi Apparatus ; Hand ; Hypothalamus ; Intestinal Mucosa ; Leptin ; Membranes ; Phenobarbital ; Receptors, Leptin ; Secretory Vesicles

Pancreatic acinar cells exhibit a polarity that is characterized by the localization of secretory granules at the apical membrane. However, the factors that regulate cellular polarity in these cells are not well understood. In this study, we investigated the effect of Mist1, a basic helix-loop-helix transcription factor, on the cellular architecture of pancreatic acinar cells. Mist1-null mice displayed secretory granules that were diffuse throughout the pancreatic acinar cells, from the apical to basolateral membranes, whereas Mist1 heterozygote mice showed apical localization of secretory granules. Deletion of the Mist1 gene decreased the expression of type 3 inositol 1,4,5-triphosphate receptors (IP3R) but did not affect apical localization and expression of IP3R2. Mist1-null mice also displayed an increase in luminal areas and an increase in the expression of zymogen granules in pancreatic acinar cells. These results suggest that Mist1 plays a critical role in polar localization of cellular organelles and in maintaining cellular architecture in mouse pancreatic acinar cells.
Acinar Cells ; Animals ; Cell Polarity ; Heterozygote ; Inositol 1,4,5-Trisphosphate Receptors ; Membranes ; Mice ; Organelles ; Phenobarbital ; Secretory Vesicles ; Transcription Factors

Insulin granule trafficking is a key step in the secretion of glucose-stimulated insulin from pancreatic β-cells. The main feature of type 2 diabetes (T2D) is the failure of pancreatic β-cells to secrete sufficient amounts of insulin to maintain normal blood glucose levels. In this work, we developed and applied tomography based on scanning transmission electron microscopy (STEM) to image intact insulin granules in the β-cells of mouse pancreatic islets. Using three-dimensional (3D) reconstruction, we found decreases in both the number and the grey level of insulin granules in db/db mouse pancreatic β-cells. Moreover, insulin granules were closer to the plasma membrane in diabetic β-cells than in control cells. Thus, 3D ultra-structural tomography may provide new insights into the pathology of insulin secretion in T2D.
Animals ; Diabetes Mellitus, Type 2 ; pathology ; Electron Microscope Tomography ; Insulin ; metabolism ; Insulin-Secreting Cells ; metabolism ; pathology ; Male ; Mice ; Mice, Inbred C57BL ; Mice, Obese ; Secretory Vesicles ; metabolism ; pathology

Primary acinic cell carcinoma (ACC) of the lung is very rare and this tumor is thought to arise from pluripotent cells of the submucosal glands of the tracheobronchial tree. We report here on a case of primary ACC of the lung in a 68-year-old man who had a solitary pulmonary nodule in the left lower lobe. The patient was symptomless and the lesion was found on a chest X-ray taken during a regular health checkup. The video assisted thoracoscopic surgery wedge resection revealed an ovoid yellow tan solid mass that was 1.8 cm at the largest diameter. Microscopically, the neoplastic cells grew in solid sheets of round cells with eccentric nuclei and abundant basophilic granular cytoplasm. There were no mitotic figures or areas of pleomorphic or anaplastic cells. Immunohistochemical staining for cytokeratin (AE1/AE3) was positive, but the staining for chromogranin A and CD56 was negative. Ultrastructural examination revealed polyhedral cells with many zymogen granules of varying electron density. The patient is well 4 months postoperatively.
Acinar Cells ; Aged ; Basophils ; Carcinoma, Acinar Cell ; Chromogranin A ; Cytoplasm ; Electrons ; Humans ; Keratins ; Lung ; Lung Neoplasms ; Secretory Vesicles ; Solitary Pulmonary Nodule ; Thoracic Surgery, Video-Assisted ; Thorax ; Triacetoneamine-N-Oxyl