Biliary Tract Epithelium Research Articles

H+-peptide cotransport in the human bile duct epithelium cell line SK-ChA-1.

This study describes for the first time the presence of H+-peptide cotransport in cells of the bile duct. Uptake of [glycine-1-14C]glycylsarcosine ([14C]Gly-Sar) in human extrahepatic cholangiocarcinoma SK-ChA-1 cells was stimulated sevenfold by an inwardly directed H+ gradient. Transport was mediated by a low-affinity system with a transport constant (Kt) value of 1.1 mM. Several dipeptides, cefadroxil, and delta-aminolevulinic acid, but not glycine and glutathione, were strong inhibitors of Gly-Sar uptake. SK-ChA-1 cells formed tight, polarized monolayers on permeable membranes. The transepithelial electrical resistance was 856 +/- 29 omega x cm(2). The transepithelial flux of [14C]Gly-Sar in apical-to-basolateral direction exceeded the basolateral-to-apical flux 11-fold. Uptake was 20-fold higher from the apical side. RT-PCR analysis using primer pairs specific for the intestinal-type peptide transporter (PEPT1) or kidney-type (PEPT2) revealed that the transport system expressed in SK-ChA-1 and also in cells of the native rabbit bile duct is PEPT1. Immunohistochemistry localized PEPT1 to the apical membrane of cholangiocytes of mouse extrahepatic biliary duct. We conclude that the cells of the mammalian extrahepatic biliary tract epithelium express the intestinal-type H+-peptide cotransporter in their apical membrane. SK-ChA-1 cells represent a convenient model to study the physiological and clinical aspects of peptide transport in cholangiocytes.

Mucosal cell proliferation activity of the gallbladder in children with anomalous arrangement of the pancreaticobiliary duct.

Anomalous arrangement of the pancreaticobiliary duct (AAPBD) is an anatomical maljunction of the bile duct and the pancreatic duct that is frequently associated with gallbladder carcinoma. In patients with AAPBD, it has been postulated that pancreatic juice regurgitates into the biliary tree, and the mixture of refluxed pancreatic juice and stagnant bile juice acts as an irritant factor to the biliary tract epithelium, leading to chronic inflammation and metaplasia. Eventually these mucosal changes may progress to invasive carcinoma. We reviewed clinicopathologic studies on epithelial changes of the gallbladder in patients with AAPBD to clarify the implications relevant to carcinogenesis. Conventional histological studies have shown that the most characteristic change observed in the gallbladder of children with this anomaly was epithelial hyperplasia. Furthermore, the incidence of mucosal hyperplasia was significantly increased in the gallbladder of children in whom the pancreatic duct joined the common bile duct (P-C type) compared with the incidence in children in whom the common bile duct joined the pancreatic duct (C-P type). In addition, cell kinetic studies have demonstrated increased cellular proliferative activity of the gallbladder in children with AAPBD. Cell proliferative activity was significantly elevated in children with the P-C type of AAPBD compared with that in children with the C-P type of anomaly. In conclusion, AAPBD may yield increased cell proliferation in the gallbladder of patients with this anomaly in early childhood, resulting in epithelial hyperplasia. Although it remains unknown which agents are responsible for promoting the activation of cellular function, it seems that bile acids and refluxed pancreatic proteases are likely play a role in such promotion. Further investigations are needed to elucidate the mechanism of increased cellular function.

Abnormal duodenal bile composition in patients with acalculous chronic cholecystitis.

Our goal was to characterize biliary lipid composition in patients with the syndrome of chronic biliary pain, absence of gallstones, and inflammation of the gallbladder mucosa (acalculous chronic cholecystitis). Duodenal bile, obtained from 27 patients with a history of right upper quadrant pain and with negative imaging studies of the biliary tract, was analyzed enzymatically for bile acids, phospholipids, and cholesterol. Fifteen patients were found to have inflammation and/or fibrosis of the gallbladder at cholecystectomy. The 15 patients with abnormal gallbladder histology had more dilute duodenal bile, as indicated by a low bile acid concentration and a lower proportion of phospholipids (p < 0.01) when values were compared with those of duodenal bile samples from postmenopausal women without gallbladder disease or from radiolucent gallstone subjects participating in the National Cooperative Gallstone Study. Cholecystectomy relieved pain in 9 of 14 patients. Some patients with acalculous chronic cholecystitis have duodenal bile samples characterized by a decreased bile acid concentration and a decreased proportion of biliary phospholipids. The low biliary bile acid concentration may result from impaired gallbladder contraction and/or secretion by the biliary tract epithelium. The low proportion of phospholipid may result from posthepatic hydrolysis of luminal phosphatidylcholine followed by absorption of the hydrolysis products. The latter process could be caused by and/or contribute to mucosal inflammation and would also elevate the cholesterol saturation of bile, increasing the risk for cholesterol gallstone formation.

Clinical problems in the surgical treatment of pancreaticobiliary maljunction

The results of surgical treatment of pancreaticobiliary maljunction at our department are described. The 67 patients who underwent surgery for this disease were divided by age into an adult group (45 patients, aged 16 years and over) and a pediatric group (22 patients, aged less than 16 years). The incidence of concomitant carcinoma before surgery and the incidence and severity of postoperative cholangitis were compared between these two groups. In addition, the cell proliferating activity of the biliary tract epithelium in cancer-free patients was compared between the two groups, using the proliferating cell nuclear antigen labeling index (PCNA LI). Ten patients (all adults) were diagnosed with cancer (gallbladder carcinoma in 7 and bile duct carcinoma in 3) before surgery. The surgical techniques used for reconstruction in the cancer-free patients were: in the adult group, hepaticoduodenostomy in 9 patients, Roux-en-Y hepaticojejunostomy in 17, jejunal interposition in 8, and another technique in 1. In the pediatric group, hepatico-duodenostomy was performed in 17 patients. Roux-en-Y hepaticojejunostomy in 3, and jejunal interposition in 2. Postoperative cholangitis occurred in 6 adults (including 2 with severe form) and 1 child (mild case). The PCNA LI of the biliary tract epithelium was high compared to control findings in the biliary tract epithelium of 10 adult patients without pancreaticobiliary maljunction. In the adult group with dilated extrahepatic bile ducts (n=10 examined) this index was 11.4% for the bile duct epithelium (control, 1.5%) and 12.7% for the gallbladder epithelium (control, 1.4%). In the adult group with non-dilated extrahepatic bile ducts (n=5 examined) it was 5.9% for the bile duct epithelium and 13.1% for the gallbladder epithelium. In the pediatric group (n=10 with extrahepatic bile duct dilatation) it was 7.5% for the bile duct and 9.7% for the gallbladder epithelium. (Differences from control values were all significant.) These results suggest that surgery for this disease should be performed as early as possible and that extrahepatic bile duct excision and biliary reconstruction should be performed whether or not extrahepatic bile ducts are dilated.

K-ras point mutations in cancerous and noncancerous biliary epithelium in patients with pancreaticobiliary maljunction

Pancreaticobiliary maljunction (PBM), an anomalous union of the pancreatic duct with the common bile duct, has frequently been shown to be associated with biliary carcinoma. However, the mechanism of carcinogenesis is unknown. Mutations of the K-ras oncogene were examined in cancerous and noncancerous biliary tract epithelium of 20 patients with PBM by an extraction of DNA from surgically resected histologic specimens. DNA was analyzed by a polymerase chain reaction single strand conformation polymorphism (PCR-SSCP) method and direct sequencing. An abnormally mobilized DNA band was detected not only in cancerous epithelium but also in hyperplastic, metaplastic, and inflammatory epithelium of the gallbladder and/or common bile duct in patients with PBM. Among the biliary epithelium of patients with PBM, point mutation of K-ras oncogenes were detected in 4 of 5 (80%) cancerous epithelium, 7 of 12 (58%) hyperplastic and metaplastic epithelium, and 8 of 18 (44%) inflammatory epithelium, whereas no point mutation of the K-ras oncogene was detected in the gallbladder epithelium in 3 control patients without PBM. Direct sequence analysis of the K-ras oncogene revealed the mutation at codon 12 substituting the wild-type glycine (GGT) for aspartic acid (GAT) in all cancerous lesions of patients with PBM. Simultaneous two-point mutations from the wild-type glycine (GGC) to arginine (CGC) at codon 13 associated with the mutation at codon 12 were also found in one case of gallbladder carcinoma and one case of bile duct carcinoma. K-ras gene mutation is involved in the carcinogenesis of biliary tract epithelium in patients with PBM, and appears to be a high risk factor for carcinogenesis of the biliary tract.

Neoplastic Disorders in 100 Patients with Adult Celiac Disease

Previous reports have suggested that the incidence of some neoplastic disorders, particularly malignant lymphoma, is increased in patients with celiac disease. In this study, the type and number of neoplastic disorders detected in 100 consecutive celiac disease patients were explored. Sixty-five patients were initially diagnosed with celiac disease before, and 35 after, age 60 years. Ten elderly celiac patients had lymphoma or small intestinal adenocarcinoma. Although the overall incidence of malignant lymphoma was 8%, similar to that in other centres, the incidence in elderly celiac patients was 23% in this study. Celiac disease was detected before or after the diagnosis of lymphoma or small intestinal adenocarcinoma. In some patients, epithelial lymphocytosis was evident in the gastric, colonic or biliary tract epithelium. In addition, other immune-mediated disorders, dermatitis herpetiformis and autoimmune thyroiditis, were common. Finally, other malignant disorders of the esophagus, stomach and colon were not detected.

Biliary epithelial cells from mice with congenital polycystic kidney disease are hyperresponsive to epidermal growth factor.

Epithelial hyperplasia is an early feature of the renal and biliary lesions in autosomal recessive polycystic kidney disease (ARPKD). To explore the cellular basis of this hyperplasia we isolated, cultured, and characterized biliary tract epithelium from common bile duct explants of mice with ARPKD (the BPK mouse) and controls. Primary cultures resulted in dense colonies of contact-inhibited epithelial cells with a homogenous growth pattern. Colony growth in serum-free basal medium (BM) of BPK-derived cells was not different from controls. Supplementation of BM with epidermal growth factor (EGF) induced a proliferative response in BPK-derived cells that was significantly increased over controls as assessed by [3H]thymidine uptake and expressed as percent change over growth in BM (BPK 239% and controls 131% of BM growth). In contrast, no differences between BPK- and control-derived cells were found with regard to the effects of BM supplementation with IGF-I, IGF-II, acidic fibroblast growth factor, keratinocyte growth factor, hepatocyte growth factor, or transforming growth factor-beta. Primary culture of biliary epithelium may provide a useful in vitro model for the study of the cellular pathophysiology of ARPKD. Our data demonstrate that increased epithelial sensitivity to EGF-like proteins may play a role in biliary epithelial proliferative changes which parallel renal tubular epithelial proliferation in ARPKD.

Choledochocele: Importance of histological evaluation

Choledochocele is a rare abnormality of unknown etiology that consists of cystic or diverticular dilatations of the intramural part of the common bile duct. The authors present a case of choledochocele with a common channel in a 15-year-old boy who had a 5-year history of intermittent right upper abdominal pain. In a review of the literature, macroscopic variations were noted as well as different types of epithelial lining inside the choledochocele. Whereas in young children mostly duodenal mucosa is described, biliary tract epithelium and undifferentiated epithelium are predominant later on. Etiologically, congenital intraluminal duodenal diverticulum should be suggested in relation to the pathogenesis of choledochocele. Treatment is total excision and reinsertion of both ducts in cases of biliary or undifferentiated epithelium; endoscopic sphincterotomy or marsupialization is indicated only when duodenal mucosa covers both sides of the choledochocele.

Experimental studies on carcinogenesis in anomalous arrangement of the pancreaticobiliary ducts.

An experimental model of anomalous arrangement of the pancreaticobiliary ducts (APBD) was produced by pancreaticocholecystostomy performed in 29 mongrel dogs. Our purpose was to study carcinogenesis of the extrahepatic biliary tract by DNA ploidy analysis with cytofluorometry. The amylase level in the bile was elevated in all 25 dogs tested except the controls. The phospholipase A2 level in the bile was elevated in all selected dogs except the controls. Common bile duct (CBD) dilatation was found in 23/29 (79%) of the dogs, and biliary stones were found in 3/29 (10%) dogs. Inflammatory changes were observed microscopically in all specimens except those from the controls. Intramural glandular structures were found in 17/25 (68%) of gallbladder (GB) specimens and 10/25 (40%) of CBD specimens; goblet cells were found in 7/25 (28%) of GB specimens and 2/25 (8%) of CBD specimens. In the controls neither glandular structures nor goblet cells were observed except for two GB specimens showing mild cholecystitis. Cytofluorometry showed 21% GB and 7% CBD diploidy, 69% GB and 65% CBD low ploidy, 10% GB and 28% CBD high ploidy patterns of histograms. These results show that, APBD may be central to high risk condition or play a key role to develop atypical biliary tract epithelium and DNA ploidy abnormality with or without biliary duct dilatation.

Established mouse liver cell lines as a model system for studying epithelio-mesenchymal interactions in morphogenesis

Four cell lines were established from both fetal and adult livers of mice (ddY strain) by colony isolation methods, and these were characterized by morphological, immunological and biochemical examination. An epithelial cell line from a fetus (eE1-10) was identified to be derived from the biliary tract epithelium. Another epithelial cell line from an adult (aE3) reconstructed bile canaliculi-like structures in aggregates and secreted several serum proteins, indicating that it was derived from the hepatic parenchyma. The other two lines (eF1 and aF1) are fibroblastic in morphology. These were derived from fetal and adult livers, respectively. Both eE1-10 and the fetal fibroblastic cell line (eF1) are hypotetraploid, whereas both aE3 and the adult fibroblastic cell line (aF1) are hypodiploid. All four cell lines showed both contact inhibition and anchorage dependency of growth. Luminal structures with basal laminar, similar to bile ducts, were reconstituted from eE1-10 cells when co-aggregated with aF1 fibroblastic cells. Luminal structures were also formed from eE1-10 cells embedded in collagen gel. These, however, had no basal lamina and there was less development of microvilli than in aggregates mixed with fibroblastic cells. These results indicate that the fibroblastic cells afford favourable conditions for maintenance of the elaborated luminal structure of epithelial cells through production of the basal lamina.

Cultured biliary tract epithelial cells/alkaline and neutral elution as a model for the detection of carcinogens to the biliary tract epithelium

Cultured biliary tract epithelial cells/alkaline and neutral elution as a model for the detection of carcinogens to the biliary tract epithelium

Distribution of TPA and cytokeratins in gastrointestinal carcinomas as revealed by immunohistochemistry

The presence and distribution of tissue polypeptide antigen (TPA) were assessed in gastrointestinal carcinomas of different origin, morphology and degree of differentiation. Immunocytochemistry was employed, using the PAP technique on formalin-fixed, paraffin-embedded material and compared with the results obtained with antibodies to cytokeratins. Like cytokeratins, TPA was a reliable marker of epithelial differentiation and showed tissue distribution patterns similar to cytokeratins, as revealed by antibodies with broad-range cytokeratin immunoreactivity. In most carcinomas, TPA-specific immunostaining was less intense than in non-neoplastic tissue. No direct relationship between intensity of TPA staining and morphological degree of differentiation and proliferation was found. TPA staining was most pronounced at the periphery of the cells. In stratified epithelium, i.e. oesophageal mucosa, basally located cells exceeded superficial cells in TPA immunoreactivity in contrast to the cytokeratin antibodies which decorated the more superficially placed cell layers. TPA and cytokeratin staining patterns were similar in neoplastic and non-neoplastic gastric, intestinal mucosa, as well as in biliary tract epithelium. Antral and cardial mucoid glands of the stomach as well as gastric carcinomas of the pylorocardial type remained unstained with both types of antibodies. Similar staining with TPA and cytokeratin antibodies was also observed in pancreatic and liver tissue. In this study, hepatocytes were, although weakly, stained by TPA antibodies and an identical staining was found with benign and malignant hepatocellular neoplasms. Ductal and ductular TPA-staining was most conspicuous and so was the immunoreactivity of cholangiocellular carcinomas. A comparison between TPA and cytokeratins was also made by immunoblotting which revealed immunoreactivity of antibodies to TPA with cytokeratin polypeptides of different species (man, mouse) and organs (epidermis, liver), particularly with the cytokeratin component 8 of human liver and the related component A of mouse liver. The significance of this finding is uncertain until the pertinent epitopes have been revealed by monoclonal mapping of the components which exhibit similar molecular weights by SDS polyacrylamide gel electrophoresis.

The influence of thyroid and testicular hormones on globule leucocytes in the rat duodenal crypt epithelium.

The globule leucocyte is a cell with a wide distribution in the digestive, respiratory, biliary, urinary and genital tract epithelia of homeotherms. It occurs in the crypts of the rat small intestine and within the epithelium on the villous bases but not on the remainder of the villi. A characteristic feature of this cell is the presence of acidophilic cytoplasmic granules, 0.5 to a few micrometers in diameter. The nucleus resembles that of intraepithelial intestinal lymphocytes. In this investigation, a quantitative study was made of the effect of thyroidectomy and/or castration on the number of globule leucocytes in the duodenal crypts of immature and adult rats. In sham-operated rats, globule leucocytes were rare, occurring with a frequency of 1 or 2 per 1,000 epithelial cells. After thyroidectomy, they increased to 14--20 per 1,000 epithelial cells. Castration did not influence the number of globule leucocytes but resulted in an increase in the number, size and acidophilia of their cytoplasmic granules. In immature rats, but not in adults, castration combined with thyroidectomy enhanced the effect of thyroidectomy, increasing globule leucocyte number to 32 per 1,000 epithelial cells. Treatment of thyroidectomized-castrates with thyroxine, initiated 38 days after operation, reduced the crypt globule leucocyte population to normal, whereas treatment with testosterone did not. Growth hormone failed to influence the elevated number of globule leucocytes in thyroidectomized rats, suggesting that this action of thyroxine was not mediated via an influence on growth hormone release. Because of their similar nuclear morphology, intraepithelial crypt lymphocytes were also counted and there was no obvious relationship in the fluctuations of these two cell populations. It is suggested that the greater number of crypt globule leucocytes in thyroid deficiency may reflect changes in the intestinal secretory immunoglobulin system and this is being investigated, beginning with a study of the distribution of IgE.

Stimulation of thymidine incorporation in mouse liver and biliary tract epithelium by lithocholate and deoxycholate

Lithocholate produces bile duct and ductular cell hyperplasia, and adenomatous hepatic nodules. The early effects of lithocholate and related bile salts on the liver and biliary tract were investigated by measuring tritiated thymidine (3HTdR) incorporation into DNA after single oral doses of bile salts. Lithocholate, in doses of 12.5 mg and above, enhanced incorporation of 3HTdR at 28 and 36 hr in gallbladder epithelium and at 36 hr in hepatocytes. Areas of hepatocellular necrosis, resembling the lesions of peliosis hepatis, occurred with 12.5- and 25-mg doses of lithocholate, but were not seen with deoxycholate, cholate, chenodeoxycholate, ursodeoxycholate, or hyodeoxycholate. Deoxycholate, and to a lesser extent cholate, also stimulated 3HTdR incorporation in both liver and gallbladder, but chenodeoxycholate did not. These studies suggest that certain bile acids rapidly exert major effects on cell kinetics in the liver and biliary tract, and that these effects depend on the structure of the bile acid molecule. Bile duct (organ) hyperplasia induced by lithocholate must depend on additional factors. The stimulation of proliferative activity by certain (particularly secondary) bile acids may have important consequences for tissues and organs exposed to the bile acid pool during its enterohepatic circulation and subsequent excretion via the colon.