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Investigative Ophthalmology & Visual... Jan 2018The role of cystic fibrosis transmembrane conductance regulator (CFTR) in lacrimal gland (LG) function has only recently received some attention, mainly from our group....
PURPOSE
The role of cystic fibrosis transmembrane conductance regulator (CFTR) in lacrimal gland (LG) function has only recently received some attention, mainly from our group. In the present study, we investigated the potential changes of LG pathology, tear secretion, ocular surface integrity, and fluid secretion in isolated LG ducts from CFTR knockout (KO) mice.
METHODS
Tear production and ocular surface integrity were investigated in anesthetized wild-type (WT) and KO mice using cotton threads and fluorescein staining, respectively. Immunofluorescence was used to localize CFTR protein in the LGs. Ductal fluid secretions evoked by forskolin (10 μM); cell-permeable cAMP analogue (8-bromo cAMP, 100 μM); or carbachol (100 μM) were measured in isolated LG ducts using video-microscopy. Intracellular Ca2+ homeostasis underlying carbachol stimulation was investigated with microfluorometry.
RESULTS
Significant decrease in tear secretion and impaired ocular surface integrity were observed in KO mice. Immunofluorescence demonstrated the predominant presence of CFTR protein in the apical membranes of the duct cells from WT mice. Continuous fluid secretion was evoked by forskolin and 8-bromo cAMP in LG ducts from WT mice, while no secretory response was observed in ducts from KO mice. Carbachol caused similar secretory responses in ducts from WT and KO animals without significant differences in cytosolic Ca2+ signaling.
CONCLUSIONS
Our results suggest the important role of CFTR in LG ductal secretion and in the maintenance of ocular surface integrity, suggesting that CFTR may be a promising target of novel therapeutic approaches in the treatment of dry eye.
Topics: Animals; Biological Transport; Cells, Cultured; Cystic Fibrosis Transmembrane Conductance Regulator; Dry Eye Syndromes; Lacrimal Apparatus; Mice; Mice, Inbred CFTR; Tears
PubMed: 29305607
DOI: 10.1167/iovs.17-22533 -
BMC Pharmacology & Toxicology Jan 20202,3,5,4'-tetrahydroxystilbence-2-O-β-D-glucoside (TSG) is a polyhydroxyphenolic compound, which exhibited a broad spectrum of pharmacological activities, such as...
BACKGROUND
2,3,5,4'-tetrahydroxystilbence-2-O-β-D-glucoside (TSG) is a polyhydroxyphenolic compound, which exhibited a broad spectrum of pharmacological activities, such as anti-inflammatory, anti-depression, anti-oxidation and anti-atherosclerosis. However, the compound had poor bioavailability and the underlying absorption mechanisms had not been studied. Therefore, the purpose of this study was to investigate the intestinal absorption mechanism of TSG.
METHODS
This study used Caco-2 cell monolayer model and single-pass intestinal perfusion model to explore the gastrointestinal absorption mechanisms of TSG. The effects of basic parameters such as drug concentration, time and pH on the intestinal absorption of TSG were analyzed by high performance liquid chromatography. The absorption susceptibility of TSG to three inhibitors, P-gp inhibitors verapamil hydrochloride and quinidine, and MRP2 inhibitor probenecid were also assessed.
RESULTS
TSG was poorly absorbed in the intestines and the absorption of TSG in stomach is much higher than that in intestine. Both in vitro and in situ experiments showed that the absorption of TSG was saturated with increasing concentration and it was better absorbed in a weakly acidic environment pH 6.4. Moreover, TSG interacts with P-gp and MRP2, and TSG was not only the substrate of the P-gp and MRP2, but also affected the expression of P-gp and MRP2.
CONCLUSIONS
It was concluded that the gastrointestinal absorption the most unique active ingredient and considered as the mechanisms of TSG involved processes passive transport and the participation of efflux transporters.
Topics: ATP Binding Cassette Transporter, Subfamily B, Member 1; Animals; Caco-2 Cells; Cell Survival; Female; Gastric Juice; Glucosides; Humans; Intestinal Absorption; Intestinal Mucosa; Intestinal Secretions; Male; Multidrug Resistance-Associated Protein 2; Multidrug Resistance-Associated Proteins; Rats, Sprague-Dawley; Stilbenes
PubMed: 31969193
DOI: 10.1186/s40360-020-0384-9 -
Experimental Physiology Sep 1991Rabbits were trained to accept a standardized feeding regime. Under anaesthesia both parotid ducts were cannulated in a retrograde direction and saliva was subsequently...
Rabbits were trained to accept a standardized feeding regime. Under anaesthesia both parotid ducts were cannulated in a retrograde direction and saliva was subsequently collected in feeding sessions involving pellets and carrots before and after the administration of propranolol. Salivary total protein and amylase concentrations were assayed and protein analysed by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). Propranolol produced a reduction in protein secretion but not fluid secretion, indicating that protein secretion is partly under beta-adrenergic control. A transient increase in protein secretion was seen 8 h after the administration of propranolol and suggested the existence of different neural mechanisms involved in protein secretion compared to synthesis. Protein output (with high fluid secretion) during feeding on pellets was higher than on carrots (with high protein concentration) and suggested a significant role of the parasympathetic nervous system. The pattern of protein secretion as seen by SDS-PAGE was similar in individual rabbits and remained largely unchanged with the different foods and in the presence of propranolol.
Topics: Amylases; Animals; Eating; Electrophoresis, Polyacrylamide Gel; Injections, Intravenous; Male; Parotid Gland; Propranolol; Rabbits; Saliva; Salivary Proteins and Peptides; Secretory Rate
PubMed: 1720624
DOI: 10.1113/expphysiol.1991.sp003538 -
PloS One 2021The Common or Brown Garden Snail, Cornu aspersum, is an invasive land snail that has successfully colonized a diverse range of global environments. Like other invasive...
The Common or Brown Garden Snail, Cornu aspersum, is an invasive land snail that has successfully colonized a diverse range of global environments. Like other invasive land snails, it is a significant pest of a variety of agricultural crops, including citrus, grapes and canola. Cornu aspersum secretes a mucus trail when mobile that facilitates locomotion. The involvement of the trail in conspecific chemical communication has also been postulated. Our study found that anterior tentacle contact with conspecific mucus elicited a significant increase in heart rate from 46.9 to 51 beats per minute. In order to gain a better understanding of the constituents of the trail mucus and the role it may play in snail communication, the protein and volatile components of mucus trails were investigated. Using two different protein extraction methods, mass spectrometry analysis yielded 175 different proteins, 29 of which had no significant similarity to any entries in the non-redundant protein sequence database. Of the mucus proteins, 22 contain features consistent with secreted proteins, including a perlucin-like protein. The eight most abundant volatiles detected using gas chromatography were recorded (including propanoic acid and limonene) and their potential role as putative pheromones are discussed. In summary, this study has provided an avenue for further research pertaining to the role of trail mucus in snail communication and provides a useful repository for land snail trail mucus components. This may be utilized for further research regarding snail attraction and dispersal, which may be applied in the fields of agriculture, ecology and human health.
Topics: Animals; Helix, Snails; Locomotion; Mucus; Proteins; Volatile Organic Compounds
PubMed: 34043643
DOI: 10.1371/journal.pone.0251565 -
The Journal of Clinical Pediatric... 2018To measure and compare the levels of salivary flow rate, pH, buffering capacity, total protein, malondialdehyde (MDA) and total antioxidant capacity (TAC) between caries...
OBJECTIVES
To measure and compare the levels of salivary flow rate, pH, buffering capacity, total protein, malondialdehyde (MDA) and total antioxidant capacity (TAC) between caries active and caries free children and to study the correlation between the DMFS/dfs score and above salivary parameters in caries active children.
STUDY DESIGN
50 caries active (DMFS/dfs ≥ 5) and 50 caries free (DMFS/dfs = 0) children aged between 6 to 12 years were included in the study. From all the children, unstimulated, mid-morning saliva samples were collected and salivary flow rate was calculated. Salivary pH, buffering capacity, total protein, MDA and TAC were measured.
RESULTS
The mean levels of salivary flow rate, pH, buffering capacity were significantly decreased (p < 0.05) and total protein, MDA and TAC were significantly increased (p < 0.05) in caries active children when compared to caries free controls. There was a proportionate decrease (p < 0.05) in salivary flow rate, pH and buffering capacity and proportionate increase (p > 0.05) in salivary total protein, MDA and TAC as DMFS/dfs score increased in caries active children.
CONCLUSIONS
Significant alteration in the levels of salivary flow rate, pH, total proteins, MDA and TAC and their correlation with DMFS/dfs score in caries active children suggest, the levels of these physico-chemical properties of saliva can act as strong indicators of caries status in children.
Topics: Antioxidants; Case-Control Studies; Child; DMF Index; Dental Caries; Female; Humans; Hydrogen-Ion Concentration; Male; Malondialdehyde; Oxidative Stress; Proteins; Saliva; Secretory Rate
PubMed: 30085875
DOI: 10.17796/1053-4625-42.6.7 -
The Journal of Cell Biology Dec 1987The relationship of N-linked glycosylation and association with heavy chain binding protein (BiP) to the secretion of Factor VIII (FVIII), von Willebrand Factor (vWF),...
The relationship of N-linked glycosylation and association with heavy chain binding protein (BiP) to the secretion of Factor VIII (FVIII), von Willebrand Factor (vWF), and tissue plasminogen activator (tPA) was studied in Chinese hamster ovary (CHO) cells. FVIII has a heavily glycosylated region containing 20 clustered potential N-linked glycosylation sites. A significant proportion of FVIII was detected in a stable complex with BiP and not secreted. Deletion of the heavily glycosylated region resulted in reduced association with BiP and more efficient secretion. Tunicamycin treatment of cells producing this deleted form of FVIII resulted in stable association of unglycosylated FVIII with BiP and inhibition of efficient secretion. vWF contains 17 potential N-linked glycosylation sites scattered throughout the molecule. vWF was transiently associated with BiP and efficiently secreted demonstrating that CHO cells are competent to secrete a highly glycosylated protein. tPA, which has three utilized N-linked glycosylation sites, exhibited low level association with BiP and was efficiently secreted. Disruption of N-linked glycosylation of tPA by either site-directed mutagenesis or tunicamycin treatment resulted in reduced levels of secretion and increased association with BiP. This effect was enhanced by high levels of tPA expression. The glycosylation state and extent of association with BiP could be correlated with secretion efficiency.
Topics: Animals; Carrier Proteins; Cell Line; Clone Cells; Endoplasmic Reticulum Chaperone BiP; Factor VIII; Glycoproteins; Glycosylation; Heat-Shock Proteins; Immunoglobulin Heavy Chains; Kinetics; Molecular Chaperones; Protein Processing, Post-Translational; Tissue Plasminogen Activator; von Willebrand Factor
PubMed: 3121636
DOI: 10.1083/jcb.105.6.2665 -
International Journal of Molecular... Jun 2016The repair of early dental caries lesions has been demonstrated by the application of the remineralisation technology based on casein phosphopeptide-stabilised amorphous...
The repair of early dental caries lesions has been demonstrated by the application of the remineralisation technology based on casein phosphopeptide-stabilised amorphous calcium phosphate complexes (CPP-ACP). These complexes consist of an amorphous calcium phosphate mineral phase stabilised and encapsulated by the self-assembly of milk-derived phosphopeptides. During topical application of CPP-ACP complexes in the oral cavity, the CPP encounters the enamel pellicle consisting of salivary proteins and peptides. However the interactions of the CPP with the enamel salivary pellicle are not known. The studies presented here reveal that the predominant peptides of CPP-ACP complexes do interact with specific salivary proteins and peptides of the enamel pellicle, and provide a mechanism by which the CPP-ACP complexes are localised at the tooth surface to promote remineralisation.
Topics: Caseins; Dental Pellicle; Humans; Protein Binding; Saliva; Salivary Proteins and Peptides
PubMed: 27294918
DOI: 10.3390/ijms17060915 -
Gut Mar 1984Brunner's gland secretion in response to infusion of secretin and glucagon was studied in the rat. Secretin was infused in doses of 15, 150 and 1500 ng/kg/h. All dose...
Brunner's gland secretion in response to infusion of secretin and glucagon was studied in the rat. Secretin was infused in doses of 15, 150 and 1500 ng/kg/h. All dose significantly increased bicarbonate and protein output and depleted Brunner's glands of PAS-positive mucin. Bicarbonate secretion was related to plasma secretin concentration, and a marked stimulatory effect of secretin was found in very low, probably physiological, plasma concentrations. Maximal bicarbonate output was obtained at a plasma concentration of secretin about 20 pmol/l. Glucagon was infused at a rate of 1.0 micrograms/kg/h and did not influence secretion rate or cell morphology. Also large doses of 5.0 and 50.0 micrograms/kg/h had no effect on Brunner's gland secretion. It is concluded that secretin in very low plasma concentrations stimulates secretion of bicarbonate, protein and mucus from Brunner's glands in the rat, while glucagon has no effect, and it is suggested that secretin may be involved in the physiological regulation of Brunner's gland secretion.
Topics: Animals; Bicarbonates; Brunner Glands; Dose-Response Relationship, Drug; Duodenum; Female; Glucagon; Intestinal Secretions; Proglucagon; Protein Precursors; Proteins; Rats; Rats, Inbred Strains; Secretin; Secretory Rate
PubMed: 6698442
DOI: 10.1136/gut.25.3.264 -
Japanese Journal of Pharmacology Oct 1985Effects of bromhexine and pilocarpine on the secretions of submaxillary saliva in dogs and of tears in rabbits were investigated including their effects on lysozyme...
Effects of bromhexine and pilocarpine on the secretions of submaxillary saliva in dogs and of tears in rabbits were investigated including their effects on lysozyme activity in an attempt to elucidate the efficacy of bromhexine on Sjögren's syndrome. Pilocarpine (0.3 mg/kg, p.o.) significantly increased spontaneous salivary flow rate, but bromhexine (20 and 40 mg/kg, p.o.) had almost no influence on spontaneous salivary flow rate. Pilocarpine increased total protein, saccharide, lysozyme and IgA secretions in saliva under electrical stimulation of the chorda tympani. Bromhexine did more markedly increase total lysozyme and IgA secretions in saliva, with minor increases in total protein and saccharide secretions. Pilocarpine (0.4 mg/kg, i.v.) had almost no influence on lysozyme concentration in tears, whereas it markedly increased tear secretion volume leading to an increase in total lysozyme secretion. On the other hand, bromhexine (4 and 8 mg/kg, i.v.) significantly increased both lysozyme concentration and total lysozyme secretion in tears from 50 min after injection, without influencing tear secretion volume. From these findings, it is suggested that bromhexine may work effectively on Sjögren's syndrome by acting to accelerate the secretions of lysozyme and IgA in saliva and tears, which are known to have antiinflammatory and bacteriocidal effects.
Topics: Animals; Bromhexine; Dogs; Male; Muramidase; Pilocarpine; Proteins; Saliva; Salivation; Tears; Time Factors
PubMed: 4087569
DOI: 10.1254/jjp.39.241 -
Cell Research Sep 2020
Topics: Bodily Secretions; Protein Transport; Vesicular Transport Proteins
PubMed: 32728197
DOI: 10.1038/s41422-020-0382-x