BACKGROUND & AIMS Excessive consumption of ethanol is one of the most common causes of acute and chronic pancreatitis. Alterations to the gene encoding the cystic fibrosis transmembrane conductance regulator (CFTR) also cause pancreatitis. However, little is known about the role of CFTR in the pathogenesis of alcohol-induced pancreatitis. METHODS We measured CFTR activity based on chloride concentrations in sweat from patients with cystic fibrosis, patients admitted to the emergency department because of excessive alcohol consumption, and healthy volunteers. We measured CFTR levels and localization in pancreatic tissues and in patients with acute or chronic pancreatitis induced by alcohol. We studied the effects of ethanol, fatty acids, and fatty acid ethyl esters on secretion of pancreatic fluid and HCO3− , levels and function of CFTR, and exchange of Cl− for HCO3− in pancreatic cell lines as well as in tissues from guinea pigs and CFTR knockout mice after administration of alcohol. RESULTS Chloride concentrations increased in sweat samples from patients who acutely abused alcohol but not in samples from healthy volunteers, indicating that alcohol affects CFTR function. Pancreatic tissues from patients with acute or chronic pancreatitis had lower levels of CFTR than tissues from healthy volunteers. Alcohol and fatty acids inhibited secretion of fluid and HCO3− , as well as CFTR activity, in pancreatic ductal epithelial cells. These effects were mediated by sustained increases in concentrations of intracellular calcium and adenosine 3’,5’-cyclic monophosphate, depletion of adenosine triphosphate, and depolarization of mitochondrial membranes. In pancreatic cell lines and pancreatic tissues of mice and guinea pigs, administration of ethanol reduced expression of CFTR messenger RNA, reduced the stability of CFTR at the cell surface, and disrupted folding of CFTR at the endoplasmic reticulum. CFTR knockout mice given ethanol or fatty acids developed more severe pancreatitis than mice not given ethanol or fatty acids. CONCLUSIONS Based on studies of human, mouse, and guinea pig pancreata, alcohol disrupts expression and localization of the CFTR. This appears to contribute to development of pancreatitis. Strategies to increase CFTR levels or function might be used to treat alcohol-associated pancreatitis.
PurposeThe 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.MethodsTear 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.ResultsSignificant 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.ConclusionsOur 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.
Although the pathogenesis of cervical inlet patch (CIP) is not fully understood, most authors consider it as a congenital abnormality, whereas others surmise it to be related to gastroesophageal reflux disease (GERD). We aimed to evaluate esophageal function and the prevalence of GERD and Barrett's esophagus in patients with CIP. GERD is defined by the presence of erosive esophagitis or an abnormal pH monitoring. Seventy-one consecutive patients with endoscopic and histological evidence of CIP were prospectively evaluated. Esophageal symptom analysis, 24-hour simultaneous biliary reflux and double-channel pH-monitoring, and esophageal manometry were carried out in 65/71 (92%) patients and in 25 matched controls. Six patients were not suitable for testing and were, therefore, excluded. The histological evaluation of the heterotopic islands showed cardia and/or oxyntic mucosa in 64/65 (98%) patients and specialized intestinal metaplasia (SIM) in one patient (2%). The cardia and/or oxyntic mucosa was accompanied by focally appearing pancreatic acinar metaplasia and pancreatic ductal metaplasia in 7/64 (11%) and in 1/64 (2%), superficial mucous glands in 6/64 (9%), and SIM in 2/64 (3%) cases. In total, SIM was present in three patients (5%), and one of them had low-grade dysplasia. At the gastroesophageal junction, 28 (43%) patients had columnar metaplasia, including nine (14%) patients with SIM. Erosive esophagitis was present in 37 (57%) cases. Thirty-two patients (49%) had abnormal acid reflux in the distal and 25 (38%) in the proximal esophagus. Abnormal biliary reflux was present in 25 (38%) cases. On the basis of endoscopic and pH studies, GERD was established in 44/65 (68%) patients. Typical reflux symptoms were common (33/65, 51%). The combined 24-hour biliary and double-channel pH-monitoring detected significantly more significant acidic reflux at both measurement points and significantly longer bile exposure time in the distal esophagus in patients with CIP. Acid secretion in the CIP was detected in three (5%) cases. Esophageal manometry revealed decreased LES pressure and prolonged relaxation with decreased peristaltic wave amplitude, and an increased number of simultaneous contractions in the esophageal body. The detailed evaluation of the esophageal morphology and function in subjects with CIP showed a high prevalence of GERD and Barrett's esophagus. Further studies are needed to evaluate whether combined acidic and biliary reflux is able to promote similar histomorphological changes in the CIP, as it is shown distally in patients with Barrett's esophagus.
Antireflux surgery can appropriately control the reflux disease in a majority of the patients who had unsuccessful medical treatment, and it may inhibit the progression and induce the regression of Barrett's metaplasia in a significant proportion of these patients.
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