Pathologic features of hepatolithiasis in Japan

Gross and histological lesions in the livers of sika deer with particular emphasis on fascioliasis

We performed gross and histological examinations of the livers of sika deer (Cervus nippon yesoensis) in Hokkaido, Japan. Out of 1,381 deer slaughtered for venison production, thickening and dilation of the large intrahepatic bile ducts and Fasciola flukes in the duct lumens were detected in 621 deer (45.0%). Furthermore, 107 non-bile lesions (75 intrahepatic and 32 capsular lesions) were detected during gross examinations. Histologically, the bile duct lesions included chronic proliferative cholangitis, papillary hyperplasia, goblet cell and pyloric gland metaplasia, and periductal fibrosis. Many of the intrahepatic non-bile duct lesions (53/75, 71%) were considered to be Fasciola fluke migration-associated lesions, including two lesion types: necrosis, hemorrhage, and eosinophilic granuloma formation (29 lesions), and lymphoid tissue formation (24 lesions). Lymphoid tissue formation was considered to result from the persistent immune responses against dead Fasciola flukes. An epidermoid liver cyst was found incidentally, which has not been reported in the veterinary literature. In summary, this study demonstrated the predominance of fascioliasis-associated lesions in sika deer livers. The gross and histological lesions caused by Fasciola flukes in sika deer were similar to fascioliasis in other animals. Moreover, we described lymphoid tissue formation as a fascioliasis-associated lesion for the first time. The fact that bile duct lesions (45.0%) had a markedly higher prevalence than fascioliasis-associated parenchymal lesions (53/1,381, 3.8%) indicated that sika deer are a permissive host for fascioliasis. Our results provide information that will aid pathological examinations of sika deer.

Perihilar Hepatectomy for Hepatolithiasis with Compressed Hilar Bile Duct Induced by Perihilar Hyperplasia of Liver

Background: Stone recurrence is a major problem limiting the effects of surgical treatment for hepatolithiasis. It was showed that hyperplasia of perihilar liver may compress the hepatic portal and cause deficient bile flow because of compressed hilar bile duct, thereby leading to the formation of bile stasis and precipitating stone recurrence. This retrospective study aimed to evaluate the efficiency of perihilar hepatectomy for hepatolithiasis with compressed hilar bile duct induced by perihilar hyperplasia of liver. Methods: 135 patients with compressed hilar bile duct induced by hypertrophied perihilar liver were included in this study from January 2011 to July 2016. Among these patients, 77 underwent conventional operation procedure (control group) and 58 underwent conventional operation procedure added by perihilar hepatectomy (perihilar hepatectomy group). Clinical data containing preoperative data, intraoperative data, operation complications, and short-term and long-term outcomes were collected. Results: The demographic and disease-related characteristics of the two groups were comparable. The two groups were not remarkably different in operation-related characteristics. The incidence of bile leakage in the perihilar hepatectomy group was substantially higher than that in the control group. Other postoperative complications were not remarkably different between the two groups. In the long-term postoperative follow-up period, the incidence of the recurrence of stones and cholangitis in the control group was considerably higher than that in the perihilar hepatectomy group. Conclusions: Based on conventional operation procedure, additional perihilar hepatectomy is a reliable intervention with definite clinical effects for hepatolithiasis with compressed hilar bile duct induced by hypertrophied perihilar liver.

Is Osteopontin a Friend or Foe of Cell Apoptosis in Inflammatory Gastrointestinal and Liver Diseases?

Osteopontin (OPN) is involved in a variety of biological processes, including bone remodeling, innate immunity, acute and chronic inflammation, and cancer. The expression of OPN occurs in various tissues and cells, including intestinal epithelial cells and immune cells such as macrophages, dendritic cells, and T lymphocytes. OPN plays an important role in the efficient development of T helper 1 immune responses and cell survival by inhibiting apoptosis. The association of OPN with apoptosis has been investigated. In this review, we described the role of OPN in inflammatory gastrointestinal and liver diseases, focusing on the association of OPN with apoptosis. OPN changes its association with apoptosis depending on the type of disease and the phase of disease activity, acting as a promoter or a suppressor of inflammation and inflammatory carcinogenesis. It is essential that the roles of OPN in those diseases are elucidated, and treatments based on its mechanism are developed.

How the biliary tree maintains immune tolerance?

The liver is a vital organ with distinctive anatomy, histology and heterogeneous cell populations. These characteristics are of particular importance in maintaining immune homeostasis within the liver microenvironments, notably the biliary tree. Cholangiocytes are the first line of defense of the biliary tree against foreign substances, and are equipped to participate through various immunological pathways. Indeed, cholangiocytes protect against pathogens by TLRs-related signaling; maintain tolerance by expression of IRAK-M and PPARγ; limit immune response by inducing apoptosis of leukocytes; present antigen by expressing human leukocyte antigen molecules and costimulatory molecules; recruit leukocytes to the target site by expressing cytokines and chemokines. However, breach of tolerance in the biliary tree results in various cholangiopathies, exemplified by primary biliary cholangitis, primary sclerosing cholangitis and biliary atresia. Lessons learned from immune tolerance of the biliary tree will provide the basis for the development of effective therapeutic approaches against autoimmune biliary tract diseases. This article is part of a Special Issue entitled: Cholangiocytes in Health and Disease edited by Jesus Banales, Marco Marzioni, Nicholas LaRusso and Peter Jansen.

The 2016 diagnostic criteria for primary sclerosing cholangitis

BACKGROUND

Primary sclerosing cholangitis (PSC) is a chronic cholestatic liver disease of unknown cause that is characterized pathologically by an inflammatory and fibrotic process centered on the epithelium, leading to diffuse biliary stenosis and increased wall thickness throughout the intra- and extra-hepatic biliary trees. A nationwide survey in Japan revealed several differences in the clinical aspects of PSC between Japan and Western countries. PSC was recently designated an intractable hepatobiliary disease in Japan. The aim of this study was to establish Japanese diagnostic criteria for PSC according to the current Japanese conditions.

METHODS

The Intractable Hepato-Biliary Diseases Study Group in Japan of the Committee of Research on Measures for Intractable Diseases established a working group consisting of researchers specializing in PSC and proposed the 2016 Japanese diagnostic criteria for PSC.

RESULTS

The diagnostic criteria consisted of the major and minor items. Major items are directly related to bile duct changes based on biliary tract imaging and an increased alkaline phosphatase level. Minor items consist of an association with inflammatory bowel disease and liver histology.

CONCLUSION

The diagnostic criteria for PSC are useful for general physicians in practice.

Choledochoscopic high-frequency needle-knife electrotomy for treatment of anastomotic strictures after Roux-en-Y hepaticojejunostomy

BACKGROUND

Anastomotic stricture is a complex and substantial complication following Roux-en-Y hepaticojejunostomy. Initially, endoscopic and percutaneous approaches are often attempted, but the gold standard remains surgical biliary reconstruction, especially for refractory stricture. However, this solution leaves much room for improvement, due to the challenging nature of the biliary reconstruction procedure, in which anastomotic stricture may still occur.

AIMS

To investigate the feasibility and effectiveness of choledochoscopic high-frequency needle-knife electrotomy as an intervention in the treatment of anastomotic strictures following Roux-en-Y hepaticojejunostomy.

METHODS

From February 2010 to October 2014, clinical data was collected and retrospectively compared for patients who underwent balloon dilation or/and choledochoscopic high-frequency needle-knife electrotomy for the treatment of anastomotic strictures after Roux-en-Y hepaticojejunostomy.

RESULTS

A total of 38 patients underwent successful choledochoscopic treatment and all the anastomotic strictures were removed successfully, 19 of which were treated with electrotomy, 7 with balloon dilation, and 12 with both electrotomy and balloon dilation. Among these groups,the average operating times were 6.9 ± 2.4 min,10.1 ± 6.8 min, and 20.2 ± 13.5 min, respectively. The average stent supporting times were 6.3 ± 0.7 months, 6.5 ± 0.6 months, and 6.1 ± 0.4 respectively. The mean follow-up after stent removal was 42.1 ± 27.4 months, and in 26.3 % (5/19), 28.5 % (2/7) and 16.7 % (2/12) of cases, recurrent anastomotic stricture occurred. Of these 9 total patients with recurrent anastomotic, two patients were successfully rescued by full-covered self-expanding removable metal stents and 7 patients by electrotomy combined with balloon dilation.

CONCLUSIONS

Choledochoscopic high-frequency needle-knife electrotomy is both feasible and safe in the treatment of anastomotic stricture after Roux-en-Y hepaticojejunostomy, with a similar long-term outcome to balloon dilation in treating anastomotic stricture after Roux-en-Y hepaticojejunostomy. A combination of choledochoscopic electrotomy concurrent with balloon dilation should be recommended based on the low rate of recurrence.

Hepatolithiasis and intrahepatic cholangiocarcinoma: A review

Although the incidence of hepatolithiasis is decreasing as the pattern of gallstone disease changes in Asia, the prevalence of hepatolithiasis is persistently high, especially in Far Eastern countries. Hepatolithiasis is an established risk factor for cholangiocarcinoma (CCA), and chronic proliferative inflammation may be involved in biliary carcinogenesis and in inducing the upregulation of cell-proliferating factors. With the use of advanced imaging modalities, there has been much improvement in the management of hepatolithiasis and the diagnosis of hepatolithiasis-associated CCA (HL-CCA). However, there are many problems in managing the strictures in hepatolithiasis and differentiating them from infiltrating types of CCA. Surgical resection is recommended in cases of single lobe hepatolithiasis with atrophy, uncontrolled stricture, symptom duration of more than 10 years, and long history of biliary-enteric anastomosis. Even after resection, patients should be followed with caution for development of HL-CCA, because HL-CCA is an independent prognostic factor for survival. It is not yet clear whether hepatic resection can reduce the occurrence of subsequent HL-CCA. Furthermore, there are no consistent findings regarding prediction of subsequent HL-CCA in patients with hepatolithiasis. In the management of hepatolithiasis, important factors are the reduction of recurrence of cholangitis and suspicion of unrecognized HL-CCA.

Choledochoscopic high-frequency needle-knife electrotomy as an effective treatment for intrahepatic biliary strictures

BACKGROUND AND AIM

Hepatolithiasis is associated with the presence of intrahepatic biliary strictures, and balloon dilatation is the main approach. However, this method is difficult to implement if the bile duct distal to the stricture is blocked by stones. Therefore, alternative methods need to be explored to effectively treat hepatolithiasis. The aim of this study is to investigate the feasibility and effectiveness of choledochoscopic high-frequency needle-knife electrotomy for the treatment of intrahepatic biliary strictures.

METHODS

Clinical data of 58 patients suffering from intrahepatic bile duct strictures from January 2011 to January 2013 were retrospectively analyzed. Choledochoscopic electrotomy was used to resolve the strictures.

RESULTS

One hundred thirty-four sites of intrahepatic bile duct strictures were discovered. The average operating time of electrotomy is 5.6 min (range, 1 ∼ 15 min). Structured bile duct tissue bleeding occurred in eight sites (8/134, 6.0%) but were resolved by endoscopic high-frequency electric cautery. After the operations, 14 cases of cholangitis (14/58, 24.1%), three cases of delayed hemobilia, one case of liver abscess (1/58, 1.7%), and seven cases of stenting exodus (7/58, 12.1%) were observed despite conservative treatment and stenting reset. The average supporting time was 7.0 months (6 ∼ 9 months). No abnormal bile duct structure or presence of stone was found according to choledochoscopy. The follow-up period ranged from 12 to 48 months. Hepatolithiasis recurred in five (5/58, 8.6%) patients, and the cumulative recurrent probability of intrahepatic bile duct stricture was 5.2% (7/134).

CONCLUSIONS

Choledochoscopic high-frequency needle-knife electrotomy could be considered as a simple, safe, and effective complementary approach for treating intrahepatic biliary strictures.

Participation of peribiliary glands in biliary tract pathophysiologies

AIM: To investigate the roles of peribiliary glands around the bile ducts in the pathophysiology of the biliary tract.

METHODS: The expression of fetal pancreatic markers, pancreatic duodenal homeobox factor 1 (PDX1) and hairy and enhancer of split 1 (HES1) and endodermal stem/progenitor (S/P) cell markers [CD44s, chemokine receptor type 4 (CXCR4), SOX9 and epithelial cell adhesion molecule (EpCAM)] were examined immunohistochemically in 32 normal adult livers (autopsy livers) and 22 hepatolithiatic livers (surgically resected livers). The latter was characterized by the proliferation of the peribiliary glands. Immunohistochemistry was performed using formalin-fixed, paraffin-embedded tissue sections after deparaffinization. Although PDX1 and HES1 were expressed in both the nucleus and cytoplasm of epithelial cells, only nuclear staining was evaluated. SOX9 was expressed in the nucleus, while CD44s, CXCR4 and EpCAM were expressed in the cell membranes. The frequency and extent of the expression of these molecules in the lining epithelia and peribiliary glands were evaluated semi-quantitatively based on the percentage of positive cells: 0, 1+ (focal), 2+ (moderate) and 3+ (extensive).

RESULTS: In normal livers, PDX1 was infrequently expressed in the lining epithelia, but was frequently expressed in the peribiliary glands. In contrast, HES1 was frequently expressed in the lining epithelia, but its expression in the peribiliary glands was focal, suggesting that the peribiliary glands retain the potential of differentiation toward the pancreas and the lining epithelia exhibit properties to inhibit such differentiation. This unique combination was also seen in hepatolithiatic livers. The expression of endodermal S/P cell markers varied in the peribiliary glands in normal livers: SOX9 and EpCAM were frequently expressed, CD44s infrequently, and CXCR4 almost not at all. The expression of these markers, particularly CD44s and CXCR4, increased in the peribiliary glands and lining epithelia in hepatolithiatic livers. This increased expression of endodermal S/P cell markers may be related to the increased production of intestinal and gastric mucin and also to the biliary neoplasia associated with the gastric and intestinal phenotypes reported in hepatolithiasis.

CONCLUSION: The unique expression pattern of PDX1 and HES1 and increased expression of endodermal S/P cell markers in the peribiliary glands may be involved in biliary pathophysiologies.

Osteopontin Expression in Patients with Hepatolith

To investigate the role of osteopontin (OPN) in the formation of hepatolith, we have immunohistochemically studied the involvement of OPN in hepatolithiasis in the intrahepatic bile ducts and the intramural and extramural glands, and in stones. In our hospital, 17 hepatic resections for hepatolithiasis were carried out from June 2006 to October 2009. Immunohistochemistry was performed on 17 liver specimens with hepatolith and on 24 control liver specimens without hepatolith. We compared the osetopontin expression in the epithelia of the intrahepatic bile ducts and peribiliary glands or periglandular macrophages. Staining for OPN was positive in the cytoplasm of the epithelial cells of stone-containing intrahepatic bile ducts and the intramural and extramural glands, and in stones. But there were no significant differences between the hepatolithiasis group and the control group for the OPN immunoreactivity of the luminal surface of the epithelial cells of the intrahepatic bile ducts and intramural and extramural glands. The stone-containing intrahepatic bile ducts were infiltrated by macrophages that showed intense staining for OPN. The core and matrix of the stones showed OPN immunoreactivity. The degree of OPN from the cytoplasm of the epithelia of the intrahepatic bile ducts and peribiliary glands or periglandular macrophages was different between hepatolithiasis and control groups. Our result suggests that the OPN from the intrahepatic bile ducts and peribiliary glands plays a role in the formation of intrahepatic stone.

Monolobar ductal plate malformation disease of the liver

We herein report a unique monolobar hepatic disease composed of Caroli's disease, peribiliary cysts, ductal plate malformations, peribiliary gland proliferation, hepatolithiasis, and portal phlebosclerosis with thrombi. A 73-year-old man underwent abdominal imaging, which revealed multiple segmental dilations of the left intrahepatic bile ducts. Polycystic kidney diseases were absent. Intrahepatic cholangiocarcinoma was suspected, and extended left lobectomy of the liver was preformed. Grossly, the hepatic left lobe was atrophic, and partly replaced by fibrous tissue. The intrahepatic bile ducts were dilated (Caroli's disease), and showed small calcium bilirubinate hepatoliths. Microscopically, the intrahepatic bile duct showed non-obstructive segmental dilations (Caroli's disease), numerous peribiliary cysts, numerous ductal plate malformations, proliferation of intrahepatic peribiliary glands, and calcium bilirubinate hepatolithiasis. Portal veins showed phlebosclerosis with thrombi. Immunohistochemically, the various biliary epithelial cells were positive for cytokeratin (CK) 7, 8, 18, and 19, and for MUC6 and CD10. They were negative for MUC2 and MUC5AC. The ductal plate malformations were positive for fetal biliary antigen MUC1, but other biliary cell types were negative for MUC1. The present case resembles 'monolobar Caroli's disease'. We believe that the present monolobular liver disease was congenital in origin.

Anti-proliferation activity of celecoxib in cholangitis

AIM: To investigate the application value of celecoxib in treating chronic proliferative cholangitis (CPC).

METHODS: Thirty healthy male Sprague-Dawley rats were randomly divided into three groups: sham-operation group (n = 10), CPC model group (n = 10), and celecoxib therapy group (n = 10). CPC was induced in rats by inserting a 5-0 nylon suture into the common bile duct up to the porta hepatis retrogradely through the vater papilla. Rats in the sham-operation group only underwent abdominal wall incision and suturing. Celecoxib [50 mg/(kg·d)] was injected into the abdominal cavity of each rat in the therapy group from day 1 after operation. All rats were executed 1 wk after operation. The anti-proliferation activity of celecoxib was evaluated by hematoxylin and eosin (HE) staining, periodic acid-Schiff (PAS) staining, Masson staining and immunohistochemistry staining of the biliary epithelial mucosa, submucosal gland and collagen fiber in the bile duct wall of CPC rats.

RESULTS: The proliferative degree of the biliary epithelial mucosa and submucosal gland as well as the fibrotic degree of the biliary wall in the celecoxib therapy group were obviously lower than those in the CPC group, but still higher than those in the sham-operation group. Immunohistochemistry analysis showed that the expression intensity of cyclooxygenase 2 (COX-2) in the celecoxib therapy group was obviously inferior to that in the CPC model group (IA: 8.62 ± 0.19 vs 35.27 ± 0.43, P < 0.05), but close to that in the sham-operation group (IA: 8.62 ± 0.19 vs 8.41 ± 0.13, P > 0.05).

CONCLUSION: By down-regulating COX-2 expression, celecoxib can effectively inhibit the hyperplasia of the biliary epithelial mucosa, submucosal gland, and collagen fiber and reduce the amount of mucous glycoprotein secreted by the submucosal gland, thus holding the promise for controlling CPC and reducing the recurrence of intrahepatic bile duct stones.

Efficacy of antisense gene therapy for proliferative cholangitis

AIM: To compare the effects of short hairpin RNAs (shRNAs) targeting the proliferating cell nuclear antigen (PCNA), c-Myc and cdc2 k genes on the hyperplastic behavior and lithogenic potential of proliferative cholangitis (PC), and to select the best target for antiproliferative treatment of PC.

METHODS: A rat model of PC was developed by retrogradely inserting a nylon thread into the common bile duct. Using the nylon thread as the guide wire, an intralumenal injection of PCNA, c-Myc and cdc2 k shRNAs into the common bile duct was performed in three different groups of model rats, respectively.

RESULTS: Compared to the c-Myc and cdc2 k shRNA treatment groups, the degree of hyperplasia of biliary epithelium and collagen fibers in the bile duct wall in the PCNA shRNA treatment group were significantly decreased. In addition, the protein expression and secretion of mucin from the hyperplastic biliary epithelium and peribiliary gland were remarkably reduced in the PCNA shRNA treatment group.

CONCLUSION: PCNA shRNA possesses more strong inhibitory effects on collagen fiber hyperplasia in and mucin secretion from the bile duct wall of rats with experimental PC than c-Myc and cdc2 k shRNAs. Therefore, PCNA shRNA holds more promise for prevention of postoperative biliary restenosis and stone recurrence in PC patients.

Significance of controlling chronic proliferative cholangitis in the treatment of hepatolithiasis

BACKGROUND

Recently, high stone recurrence and biliary restenosis rates in hepatolithiasis patients have been confirmed to be closely related to chronic proliferative cholangitis (CPC). However, the effective management of CPC has not yet been established.

METHODS AND RESULTS

A vicious cycle exists between the presence of intrahepatic calculi and CPC: both the stone itself and secondary biliary infection can stimulate persistent hyperplasia in the biliary duct wall, leading to the occurrence of CPC and biliary stricture. The recurrent attacks of CPC will, in turn, facilitate new stone formation via mucoglycoprotein production, or induced biliary stricture and cholestasis. Thus, even when the stone is completely removed and the biliary tract stenosis is corrected, residual CPC will persist and progress, with an underlying risk for postoperative stone recurrence and biliary tract restenosis. Therefore, the perfect hepatolithiasis treatment would target stone removal and correction of the biliary tract stricture, as well as control of postoperative residual CPC. In fact, CPC, the management of which has been traditionally ignored, is the key to breaking this vicious cycle.

CONCLUSIONS

Overall, the subsequent treatment of residual CPC after operation or choledochoscopic lithotomy would be helpful to decrease postoperative stone recurrence and the rate of biliary restenosis. Adding such treatment would reduce the incidence of surgical reintervention and choledochoscopic lithotomy, and it would also improve the postoperative hepatolithiasis outlook.

Effects of lipopolysaccharide on platelet-derived growth factor isoform and receptor expression in cultured rat common bile duct fibroblasts and cholangiocytes

BACKGROUND AND AIM

Little is known about the role of platelet-derived growth factor (PDGF) in biliary fibrosis in the setting of bacterial colonization of the biliary tree. We therefore sought to investigate whether exposure to bacterial lipopolysaccharide (LPS) alters PDGF isoform and receptor expression in cultured rat common bile duct fibroblasts (CBDF) and normal rat cholangiocytes (NRC).

METHODS

Collagen content in cells and media was assessed by colorimetric assay and gel electrophoresis. mRNA levels of PDGF-A and -B, and PDGF-Receptors (PDGF-R) alpha and beta were measured by relative quantitative real-time PCR. Protein levels of PDGF-AA, AB and BB were measured by ELISA, and PDGF-Ralpha and PDGF-Rbeta by Western blot.

RESULTS

In CBDF, LPS increased total soluble collagen synthesis and secretion. PDGF-Ralpha and beta mRNA and protein were also increased by LPS treatment in CBDF. Lipopolysaccharide treatment elicited an increase in PDGF-A and -B mRNA levels in CBDF. In NRC, levels of PDGF-AmRNAincreased in a dose-dependent fashion following LPS treatment, whereas PDGF-B mRNA showed no response. PDGF-AA secretion was higher by CBDF than by NRC. PDGF-BB levels were also higher in CBDF than in NRC. While PDGF-BB levels did not respond to LPS treatment in CBDF, there was a dosedependent response of this isoform to LPS in NRC. Intracellular and secreted PDGF-AB increased with LPS treatment in NRC.

CONCLUSIONS

These results support a model in which chronic bacterial colonization of the biliary tree induces fibrosis through PDGF-dependent mechanisms.

Proliferating cell nuclear antigen shRNA treatment attenuates chronic proliferative cholangitis in rats

BACKGROUND AND AIM

Chronic proliferative cholangitis (CPC) is currently considered as a pathological basis and major cause for the high recurrence rate of intrahepatic stones. Since CPC is a form of chronic proliferative disease, this study was designed to preliminarily investigate the inhibitory effect of proliferating cell nuclear antigen (PCNA) shRNA on the hyperplastic behavior and lithogenic potentiality of CPC.

METHODS

The rat model of CPC was given an intralumenal administration of 0.5 mL PCNA shRNA through a 20-gauge venous retained needle. PCNA shRNA-mediated effects on CPC-associated hyperplastic behavior and lithogenic potential were assessed by investigating histological changes, immunohistochemistry for Ki-67, biochemistry for beta-glucuronidase, real-time polymerase chain reaction, and western blot analysis of PCNA, procollagen I, and mucin-3.

RESULTS

PCNA shRNA treatment could efficiently inhibit the mRNA and protein expressions of the proliferation-related gene, PCNA, and Ki-67, which efficiently inhibited the hyperplastic behavior of the biliary epithelium, submucosal gland, and collagen fibers in the diseased bile duct wall. This novel treatment could efficiently inhibit the formation of acidic mucus glands, the expression of mucin-3 mRNA, and the secretion of endogenous beta-glucuronidase, thus effectively inhibiting the lithogenic potentiality of CPC. A further analysis revealed that PCNA shRNA-1 might display a more robust inhibitory effect on CPC-associated hyperplastic behavior and lithogenic potential than other gene sequences targeted in this study.

CONCLUSIONS

PCNA shRNA-1 treatment could effectively inhibit the hyperplastic behavior and lithogenic potentiality of CPC, which might facilitate the prevention of stone recurrence and biliary restenosis.

Treatment of chronic proliferative cholangitis with c-myc shRNA

AIM: To investigate the feasibility and effectiveness of c-myc shRNA in inhibiting the hyperplastic behavior and lithogenic potentiality of chronic proliferative cholangitis (CPC), in order to prevent stone recurrence and biliary restenosis.

METHODS: An animal model of CPC was established by giving intralumenally 0.5 mL of c-myc shRNA. Then, the effects of c-myc shRNA on hyperplastic behavior and lithogenic potentiality of CPC were evaluated by histological observation, immunohistochemistry, real-time PCR and Western blotting for c-myc, proliferating cell nuclear antigen (PCNA), procollagen III, mucin 5AC, enzymatic histochemistry for β-glucuronidase, and biochemistry for hydroxyproline in the diseased bile duct.

RESULTS: Treatment with c-myc shRNA efficiently suppressed the hyperplasia of biliary epithelium, submucosal gland, and collagen fiber by inhibiting mRNA and protein expression of c-myc. More importantly, it decreased the lithogenic potentiality of CPC by inhibiting the expression of mucin 5AC and the secretion of endogenous β-glucuronidase. Further investigation indicated that c-myc shRNA-3 had a better inhibitory effect on CPC.

CONCLUSION: Treatment with c-myc shRNA-3 can control CPC and reduce the lithogenic potentiality of CPC.

An immunohistochemical study of osteopontin in hepatolithiasis

BACKGROUND/PURPOSE

Mucin glycoprotein from the intrahepatic bile ducts, and from the intramural and extramural glandular epithelia, is thought to contribute to the formation of the matrix, or nucleus, in hepatolithiasis and to contribute to biomineralization systems. Osteopontin (OPN), a noncollagenous acidic bone matrix glycoprotein that possesses calcium-binding properties. To investigate the role of OPN in the genesis of hepatolithiasis, OPN was immunohistochemically studied in the intrahepatic bile ducts, intramural and extramural glands, and in stones.

METHODS

An immunohistochemical study was performed in 21 human liver specimens with hepatolithiasis, by the EnVision (Dako Japan, Kyoto, Japan) method.

RESULTS

Staining for OPN was strongly positive in the epithelium of stone-laden intrahepatic bile ducts, intramural and extramural glands, and in stones. The stone-laden intrahepatic bile ducts were infiltrated by macrophages showing intense staining for OPN. Sections of the hepatolithiasis, viewed under low magnification, showed a lamellar pattern of OPN immunolabeling, and they showed a reticular pattern under high magnification. In the center of the stones, large nestlike membranous structures were frequently present.

CONCLUSIONS

Our result indicates that OPN, an acidic glycoprotein from intrahepatic bile ducts and from intramural and extramural glandular epithelia, seems to be involved in lithiasis, both as a core protein in the early phase, and in the late phase.

Tumor necrosis factor-alpha induces the aberrant expression of mucus core protein-2 in non-neoplastic biliary epithelial cells via the upregulation of CDX2 in chronic cholangitis

AIM

Chronic cholangitis, such as hepatolithiasis, is frequently associated with goblet cell metaplasia and the aberrant expression of mucus core protein-2 (MUC2). In this study, we clarified the role of inflammatory cytokines in the expression of MUC2 in lining biliary epithelial cells (BEC) in chronic cholangitis with an emphasis on CDX2, an intestine-specific transcription factor.

METHODS

We used human hepatolithiatic livers and polycystic kidney (PCK) rats, an animal model of Caroli's disease, and cultured BEC from PCK rats. As a control, extrahepatic biliary obstruction and histologically normal livers and Crj:CD rats were used.

RESULTS

Immunohistochemically, tumor necrosis factor-alpha (TNF-alpha) was expressed in periductal inflammatory cells and BEC of the affected intrahepatic bile ducts with an aberrant expression of MUC2 and CDX2 in hepatolithiasis and the PCK rats. In cultured BEC, TNF-alpha, interleukin (IL)-1beta, IL-6, and interferon-gamma induced the expression of CDX2 mRNA, though only TNF-alpha additionally induced the expression of MUC2 mRNA. The expression of CDX2 mRNA and the MUC2 protein induced in BEC by TNF-alpha were abolished by pretreatment of nuclear factor-kappaB inhibitors.

CONCLUSION

The aberrant expression of CDX2 and MUC2 in the affected bile ducts showing goblet cell metaplasia was closely associated with TNF-alpha expressed in periductal infiltrating inflammatory cells and BEC. TNF-alpha induced the expression of CDX2 and MUC2 in cultured BEC. Taken together, it seems likely that TNF-alpha plays a role in MUC2 expression via CDX2 upregulation in the bile ducts with chronic cholangitis and goblet cell metaplasia.

Immunohistochemical analysis of the progression of flat and papillary preneoplastic lesions in intrahepatic cholangiocarcinogenesis in hepatolithiasis

BACKGROUND

Two types of precursor lesions, flat-type 'biliary intraepithelial neoplasia (BilIN)' and papillary-type 'intraductal papillary neoplasm of the bile duct (IPNB)', are proposed in the tumorigenesis of intrahepatic cholangiocarcinoma (ICC) in hepatolithiasis.

METHODS

In this study, the participation of cancer-related molecules in the progression of these two precursor lesions was examined, using 64 hepatolithiatic livers with BilIN lesions (45 livers) and IPNB lesions (19 livers) and 10 hepatolithiatic livers without neoplastic lesions as a control. The expression of E-cadherin, beta-catenin, matrix metalloproteinase-7 (MMP-7), membrane type 1-MMP (MT1-MMP), cyclin D1 and c-myc was immunohistochemically examined.

RESULTS

The membranous expression of beta-catenin decreased along with the progression in both BilIN and IPNB lineages. Membranous expression of E-cadherin was significantly decreased in invasive ICC with BilIN and IPNB in comparison with non-invasive counterparts. MMP-7 and MT1-MMP were commonly expressed in invasive ICC with BilIN (100%), while non-invasive lesions (BilIN-1, -2, -3) and the IPNB lineage were only occasionally and weakly positive for these molecules. Cyclin D1 and c-myc, target molecules of Wnt signalling, were frequently positive in the IPNB lineage (65 and 54% respectively), and interestingly nuclear beta-catenin staining, reflecting activation of Wnt signalling, was observed only in the IPNB lineage (22%) (P<0.05).

CONCLUSIONS

Decreased membranous expression of beta-catenin and E-cadherin is an early event in the tumorigenesis of both BilIN and IPNB lineages. The expression of MMP-7 and MT1-MMP was closely associated with invasive growth of the BilIN lineage. The Wnt signalling pathway may play an important role in the tumorigenesis of the IPNB lineage.

Intraductal papillary cholangiocarcinoma associated with von Meyenberg complexes: a case report

Intraductal papillary cholangiocarcinoma (IPC) is a rare form of bile duct neoplasm with only 28 cases reported in the English literature to date. We report a rare case of an IPC arising in a liver containing many von Meyenberg complexes (VMC) in a 70-year-old woman. She presented with colicky right upper quadrant pain and nausea, mimicking biliary colic. Imaging studies showed a mass in the left lobe of the liver. A left hepatectomy, which included segments 2 and 3 was performed, and an ill-defined shiny polypoid nonhomogenous mass (8.2x2.9 cm) was identified within the lumen of a dilated bile duct without invading the liver parenchyma. Histologically, the tumor was composed of papillary fronds with fine fibrovascular cores lined by tall biliary columnar mucus secreting epithelium. Focally the cells were of the gastric foveolar type. The tumor extended into the peribiliary glands and merged with an adjacent large VMC. A possibility that the carcinoma may have originated in a VMC was considered. On follow-up after 12 months the patient is doing well and is without any disease or recurrence.

Paclitaxel interrupts TGF-beta1 signaling between gallbladder epithelial cells and myofibroblasts

BACKGROUND

The cellular and molecular mechanisms of fibrogenesis in the extrahepatic biliary epithelium are not known. Transforming growth factor-beta1 (TGF-beta1) is a cytokine implicated in signaling pathways that mediate collagen formation. An observation that paclitaxel (PT), applied topically into the rat common bile duct, inhibited stricture formation led us to hypothesize that PT's effects might be due to interruption of TGF-beta1 signaling between biliary epithelial cells and subepithelial myofibroblasts.

MATERIALS AND METHODS

We tested this hypothesis using an in vitro cell-culture model in which murine gallbladder epithelial cells (GBEC) are cultured separately or cocultured with human gallbladder myofibroblasts (GBMF).

RESULTS

Exposure to Escherichia coli lipopolysaccharide (LPS) enhanced TGF-beta1 mRNA expression and stimulated TGF-beta1 protein secretion into both apical and basolateral compartments in GBEC. This effect was more prominent with basolateral secretion and was also more pronounced in the coculture system. In GBMF, collagen I mRNA expression and protein secretion were stimulated by treatment with LPS or TGF-beta1. GBMF also expressed TGF-beta1 mRNA, whose levels were enhanced by exposure to either LPS or exogenous TGF-beta1. PT inhibited LPS-induced TGF-beta1 mRNA expression and protein secretion in GBEC in both culture systems. Tumor necrosis factor-alpha mRNA expression and protein secretion were not affected by PT in GBEC, demonstrating that the effects were specific for TGF-beta1. PT also inhibited LPS- and TGF-beta1-induced collagen I mRNA expression and protein secretion in GBMF.

CONCLUSIONS

These findings support a model in which GBEC communicate with subepithelial GBMF via TGF-beta1, leading to collagen deposition and fibrosis, and in which GBMF possess autocrine mechanisms involving TGF-beta1 that could regulate collagen production. PT inhibits these fibrogenic pathways.

Interaction of Toll-like receptors with bacterial components induces expression of CDX2 and MUC2 in rat biliary epithelium in vivo and in culture

The mechanism of transformation of biliary epithelium leading to intestinal metaplasia, which is significantly involved in biliary diseases, remains unclear. CDX2, an intestine-specific transcription factor, is thought to regulate intestinal mucin MUC2 (mucus core protein) expression. We took advantage of polycystic kidney (PCK) rats as a model of chronic suppurative cholangitis with intestinal metaplasia and of cultured biliary epithelial cells (BECs) from PCK rats to clarify the causal relation between bacterial components such as pathogen-associated molecular patterns (PAMPs) and the development of intestinal metaplasia of bile ducts. Histological, immunohistochemical, and in situ hybridization studies were conducted in PCK rat livers. In cultured BECs, CDX2 and MUC2 were expressed following treatment with PAMPs and inhibitors (anti-Toll-like receptor (TLR)2/TLR4 antibody, nuclear factor-kappaB (NF-kappaB) inhibitor MG132). Chronic suppurative cholangitis with intestinal metaplasia developed as the PCK rats aged, and intestinal metaplasia and aberrant CDX2 and MUC2 expression developed in parallel. Intraluminal bacteria and the expression of TLR2 and TLR4 in BECs were demonstrated in the bile ducts, showing chronic suppurative cholangitis. In cultured BECs, treatment with PAMPs induced upregulation of CDX2 and MUC2 expression, and this effect was abolished by pretreatment with anti-TLR2 and anti-TLR4 antibody and MG132. A knockdown of CDX2 by CDX2 small interfering RNA inhibited MUC2 expression in cultured BECs induced by PAMPs, and transfection of CDX2 expression vector induced MUC2 expression. In conclusion, bacterial components may induce upregulation of the CDX2 expression followed by MUC2 expression via TLR and the NF-kappaB system in cultured BECs, and could be related to the development of intestinal metaplasia of the bile ducts.

Expression profiles of MUC mucins and trefoil factor family (TFF) peptides in the intrahepatic biliary system: physiological distribution and pathological significance

Mucin secreted by mucosal epithelial cells plays a role in the protection of the mucosal surface and also is involved in pathological processes. So far, MUC1-4, 5AC, 5B, 6-8, 11-13 and 15-17 genes coding the backbone mucin core protein have been identified in humans. Their diverse physiological distribution and pathological alterations have been reported. Trefoil factor family (TFF) peptides are mucin-associated molecules co-expressed with MUC mucins and involved in the maintenance of mucosal barrier and the biological behavior of epithelial and carcinoma cells. Intrahepatic biliary system is a route linking the bile canaliculi and the extrahepatic bile duct for the excretion of bile synthesized by hepatocytes. Biliary epithelial cells line in the intrahepatic biliary system, secreting mucin and other molecules involved in the maintenance and regulation of the system. In this review, the latest information regarding properties, expression profiles and regulation of MUC mucins and TFF peptides in the intrahepatic biliary system is summarized. In particular, we focus on the expression profiles and their significance of MUC mucins in developmental and normal livers, various hepatobiliary diseases and intrahepatic cholangiocarcinoma.

Chronic bile duct injury associated with fibrotic matrix microenvironment provokes cholangiocarcinoma in p53-deficient mice

Intrahepatic cholangiocarcinoma (CCA) is a lethal malignancy of the biliary epithelium associated with p53 mutations, bile duct injury, inflammation, and fibrosis. Here, to validate these processes in CCA, we developed a liver cirrhosis model driven by chronic intermittent toxin exposure, which provokes bile duct injury/necrosis and proliferation, fibroblast recruitment, and progressive extracellular matrix (ECM) changes. Fibrotic changes in the matrix microenvironment, typified by increased type I and III collagens and fibroblast recruitment, were shown to stimulate biliary epithelium hyperplasia with subsequent progression to malignant intrahepatic CCA only in mice harboring a p53 mutant allele. These murine CCAs bear histologic and genetic features of human intrahepatic CCA, including dense peritumoral fibrosis, increased inducible nitric oxide synthase, nitrotyrosine, and cyclooxygenase-2 expression, c-Met activation, cErbB2 overexpression, down-regulation of membrane-associated E-cadherin, and p53 codon 248 mutation. Thus, p53 deficiency, chronic bile duct injury/proliferation, and the fibrotic matrix microenvironment cooperate to induce intrahepatic CCA, highlighting the key role of the ECM microenvironment in this common liver cancer.

Preliminary study of chemical bile duct embolization to treat hepatolithiasis in rabbits

BACKGROUND

The high recurrence rate of hepatolithiasis is still a problem to be solved. The purpose of the present study was therefore to carry out a preliminary study of the practical value of chemical bile duct embolization (CBDE) to treat hepatolithiasis in rabbits.

METHODS

Chemical bile duct embolization was performed with phenol or absolute ethanol along with N-butyl-cyanoacrylate. The feasibility and effectiveness of CBDE for chemical hepatectomy was assessed by investigating histological changes, biochemistry for hydroxyproline and in situ hybridization for collagen I.

RESULTS

Histologically, the mucosal epithelia of the embolized bile ducts were entirely replaced by collagen fibers, thus effectively eradicating chronic proliferative cholangitis. Also of note, the diseased biliary duct lumens were completely filled with N-butyl-cyanoacrylate, thus effectively preventing calculus formation. The hepatocytes also disappeared completely in the periphery of the embolized lobe, demonstrating that the desired effects of chemical hepatectomy were achieved through CBDE. In a further comparison of embolizing agents, the phenol-cyanoacrylate embolized livers and bile ducts had a higher level of hydroxyproline and collagen I than those embolized with ethanol plus cyanoacrylate.

CONCLUSION

Chemical bile duct embolization is a promising approach to prevent the recurrence of hepatolithiasis and to achieve the effect of chemical hepatectomy.

Characterization of biliary intra-epithelial lymphocytes at different anatomical levels of intrahepatic bile ducts under normal and pathological conditions: numbers of CD4+CD28- intra-epithelial lymphocytes are increased in primary biliary cirrhosis

Distribution of intra-epithelial lymphocytes along intrahepatic biliary tree (bIEL), and their density and phenotype were examined in normal and diseased livers, particularly in primary biliary cirrhosis (PBC). Immunohistochemically, bIEL were examined in 28 normal livers, 13 cases of chronic viral hepatitis (CVH), 13 cases of PBC, five cases of primary sclerosing cholangitis (PSC), seven cases of extrahepatic biliary obstruction (EBO), and 16 hepatolithiatic livers. In normal livers, bIEL were relatively dense at large and septal bile ducts compared to interlobular ducts. Most of them were positive for CD3 and CD8, while a few were positive for CD4, CD20 and CD57. In CVH, PSC and EBO, neither distribution, phenotype nor density of bIEL differed from normal liver. In hepatolithiasis, numbers of CD8(+)bIEL were increased in stone-containing ducts. In PBC, numbers of CD4(+)CD28(-)bIEL, which are reportedly responsible for target tissue destruction in autoimmune diseases, were markedly increased in damaged interlobular ducts. In conclusion, CD3(+)CD8(+)bIEL may be involved in immune homeostasis of intrahepatic bile ducts in normal livers and in CVH, PSC and EBO. Altered distribution and phenotypes of bIEL in PBC and hepatolithiasis may reflect their participation in biliary lesions. Increased CD4(+)CD28(-)bIEL in damaged bile ducts of PBC may be related to immune-mediated biliary damage.

Favorable outcomes of hilar duct oriented hepatic resection for high grade Tsunoda type hepatolithiasis

AIM: To evaluate the efficacy of hilar duct oriented hepatectomy for intractable hepatolithiasis, the ventral hilum exposure (VHE) method that has been applied by the authors.

METHODS: From June 1994 to June 2004 for a period of 10 years, 153 patients who had Tsunoda type III or IV hepatolithiasis, received hepatectomy at our institution. Among these patients, 128 who underwent hepatectomy by the VHE method were the subjects for the study. We analyzed the risk of this procedure, residual rate of intra-hepatic stones, and stone recurrent rates.

RESULTS: The average age was 54.2 years, and the male to female ratio was 1:1.7. The average follow-up period was 25.6 mo (6-114 mo). There was no post-operative severe complication or mortality after the operation. The rate of residual stones was 5.4% and the rate of recurrent stones was 4.2%.

CONCLUSION: VHE is a safe surgical procedure and provides favorable treatment results of intractable hepatolithiasis. Especially, this procedure has advantage in that intra-hepatic bile duct stricture may be confirmed and corrected directly during surgery.

Adenovirus-mediated p53 gene transfer to the bile duct by direct administration into the bile in a rat cholangitis model

BACKGROUND

Hepatolithiasis is a common disease in East Asia and its aggravating factor is bile duct stenosis because of refractory cholangitis. This study investigated the feasibility of gene therapy for bile duct stenosis by administration of p53 adenoviral vectors into the bile.

MATERIALS AND METHODS

Adenoviral vectors (AxCALacZ or AxCAhp53) were injected transpapillarily into the bile in the bile duct in a rat model of cholangitis. The extent and duration of the gene expression was evaluated with X-gal staining and p53 immunostaining. The bile duct tissue was examined to evaluate the inhibitory effect on the proliferative changes at 3 and 7 days after administration, and Ki-67 labeling index was determined.

RESULTS

beta-galactosidase was expressed in the bile duct epithelia, the bile duct wall and the surrounding connective tissue. The expression of beta-galactosidase was detected at 4 weeks after the administration. Mean thickness of the bile duct wall at 7 days was 343.2 +/- 14.0 microm for the AxCAhp53 group, 446.5 +/- 25.3 microm for the AxCALacZ group and 447.1 +/- 53.4 microm for the control group. The proliferation of the bile duct wall was significantly suppressed in the AxCAhp53 group (P < 0.05). Maximum thickness was 408.0 +/- 23.9 microm for the AxCAhp53 group (P < 0.05), 650.0 +/- 49.3 microm for the AxCALacZ group, and 590.0 +/- 64.3 microm for the control group. Mean Ki-67 labeling index for the three groups was 20.7% (P < 0.05), 34.4% and 37.4%, respectively.

CONCLUSIONS

P53 gene transfer by administration of the adenoviral vector into the bile suppressed the proliferative changes in the bile duct in a rat cholangitis model.

The practical value of applying chemical biliary duct embolization to chemical hepatectomy for treatment of hepatolithiasis

BACKGROUND

The high recurrence rate of hepatolithiasis, together with the high operative risk of hepatectomy for specifically located stones, has not been effectively settled until now. Thus, the aim of this study was to investigate the feasibility and effectiveness of using chemical biliary duct embolization (CBDE) to achieve chemical hepatectomy in a rabbit model of hepatolithiasis.

MATERIALS AND METHODS

The animal model of hepatolithiasis was established using the methods of obstruction plus infection. Seven days later, the left hepatic ducts were embolized using phenol plus cyanoacrylate or absolute ethanol plus cyanoacrylate. Subsequently, the influence of CBDE on bile duct, liver, and stone formation was analyzed by histology, RT-PCR for procollagen, biochemistry, and enzymatic histochemistry for beta-glucuronidase (beta-G).

RESULTS

CBDE resulted in the entire ablation of the diseased biliary duct mucosa and the complete occlusion of the diseased biliary duct lumen, thus effectively eradicating chronic proliferative cholangitis and preventing stone formation. More importantly, CBDE also resulted in the complete fibrosis and "self-cut" in the periphery of the embolized lobe, thus achieving chemical hepatectomy. Also of note, the embolized lobe exhibited a much lower level of endogenous beta-G than the nonembolized lobe, indicating an inhibitory effect of CBDE on beta-G. Besides, the mRNA level of procollagen I in the embolized bile duct wall of phenol embolization group was significantly higher than the ethanol embolization group.

CONCLUSION

Chemical biliary duct embolization, especially using phenol plus cyanoacrylate, may prevent the recurrence of intrahepatic stone and concurrently achieve the effect of chemical hepatectomy.

Frequent p16ink4a inactivation is an early and frequent event of intraductal papillary neoplasm of the liver arising in hepatolithiasis

Intraductal papillary neoplasm of the liver (IPNL) is a precursor lesion of intrahepatic cholangiocarcinoma (ICC) arising in hepatolithiasis. In this study, 98 foci of IPNL identified in 39 surgically resected hepatolithiatic livers were investigated for expression of p16INK4a, cyclin D1, p21WAF1/CIP1, p53, mouse double-minute 2 (MDM2), and pRb. In addition, methylation-specific polymerase chain reaction (MSP) for p16 INK4a promoter region was performed in these foci. Nonneoplastic bile ducts from 11 hepatolithiatic livers, 5 histologically normal livers, and 9 cases of nonpapillary conventional ICC were used as controls. Decreased expression of p16INK4A was seen in IPNL group 1 with mild dysplasia and continued along the progression of IPNL to ICC. The expression of cyclin D1, p21WAF1/CIP1,and pRb gradually increased along the progression of IPNL to ICC and became significantly high in IPNL of group 3 (carcinoma in situ). The expression of p53 and MDM2 was increased in IPNL group 3 and group 4 with evident invasive carcinoma. MSP revealed that 54.6% of 44 IPNL foci harbored p16INK4a promoter hypermethylation, and such foci were significantly correlated with decreased expression of p16INK4a protein. Ki-67 labeling index exhibited a stepwise increase from IPNL group 1 to group 4. We conclude that p16INK4a inactivation, due mainly to its promoter hypermethylation, is a frequent and early event of IPNL and may be responsible for genetic and epigenetic alterations of other cell cycle regulators in IPNL.

IgG4-related sclerosing cholangitis with and without hepatic inflammatory pseudotumor, and sclerosing pancreatitis-associated sclerosing cholangitis: do they belong to a spectrum of sclerosing pancreatitis?

Sclerosing cholangitis (SC) is a heterogeneous disease entity. Different etiologies such as choledocholithiasis, biliary tumor, or pericholangitis can manifest as SC. Hepatic inflammatory pseudotumor (IP) is rarely associated with SC (sclerosing cholangitis associated with hepatic inflammatory pseudotumor; SC-hepatic IP), but sclerosing pancreatitis (SP) is not infrequently associated with bile duct lesions (sclerosing pancreatitis-associated sclerosing cholangitis; SP-SC). In this study, we compared the histologic changes of hepatic hilar and extrahepatic bile duct lesions of SC (7 cases), SC-hepatic IP (5 cases), SP-SC (5 cases), and typical primary sclerosing cholangitis (PSC) (5 cases). Histologically, all SP-SC cases showed extensive and dense fibrosis with marked lymphoplasmacytic infiltration, many eosinophils, and obliterative phlebitis. Four cases of SC showed bile duct lesions similar to those of SP-SC, whereas other three cases of SC showed milder lymphoplasmacytic infiltration, scant eosinophilic cell infiltration, and no obliterative phlebitis. All SC-hepatic IP cases showed bile duct lesions identical to those of SP-SC. Immunohistochemically, many IgG4-positive plasma cells were found in the bile duct lesions of all SP-SC cases, 4 SC cases with marked lymphoplasmacytic infiltration, and all SC-hepatic IP cases. By contrast, IgG4-positive plasma cells were scarce or hardly found in the remaining 3 SC cases and all PSC cases. In conclusion, 4 SC cases and all SC-hepatic IP cases showed bile duct lesions identical to those of SP-SC, suggesting that these three conditions may be a single disease entity. Their pathogenesis may be similar or closely related to that of SP, and in that respect they may represent an IgG4-related biliary disease. They may respond to steroid therapy as SP does.

Peptide antibiotic human beta-defensin-1 and -2 contribute to antimicrobial defense of the intrahepatic biliary tree

Human beta-defensins (hBDs) are important antimicrobial peptides that contribute to innate immunity at mucosal surfaces. This study was undertaken to investigate the expression of hBD-1 and hBD-2 in intrahepatic biliary epithelial cells in specimens of human liver, and 4 cultured cell lines (2 consisting of biliary epithelial cells and 2 cholangiocarcinoma cells). In addition, hBD-1 and hBD-2 were assayed in specimens of bile. hBD-1 was nonspecifically expressed immunohistochemically in intrahepatic biliary epithelium and hepatocytes in all patients studied, but expression of hBD-2 was restricted to large intrahepatic bile ducts in 8 of 10 patients with extrahepatic biliary obstruction (EBO), 7 of 11 with hepatolithiasis, 1 of 6 with primary biliary cirrhosis (PBC), 1 of 5 with primary sclerosing cholangitis (PSC), 0 of 6 with chronic hepatitis C (CH-C), and 0 of 11 with normal hepatic histology. hBD-2 expression was evident in bile ducts exhibiting active inflammation. Serum C reactive protein levels correlated with biliary epithelial expression of hBD-2. Real-time PCR revealed that in all of 28 specimens of fresh liver, including specimens from patients with hepatolithiasis, PBC, PSC, CH-C and normal hepatic histology, hBD-1 messenger RNA was consistently expressed, whereas hBD-2 messenger RNA was selectively expressed in biliary epithelium of patients with hepatolithiasis. Immunobloting analysis revealed hBD-2 protein in bile in 1 of 3 patients with PSC, 1 of 3 with PBC, and each of 6 with hepatolithiasis; in contrast, hBD-1 was detectable in all bile samples examined. Four cultured biliary epithelial cell lines consistently expressed hBD-1; in contrast these cell lines did not express hBD-2 spontaneously but were induced to express hBD-2 by treatment with Eschericia coli, lipopolysaccharide, interleukin-1beta or tumor necrosis factor-alpha. In conclusion, these findings suggest that in the intrahepatic biliary tree, hBD-2 is expressed in response to local infection and/or active inflammation, whereas hBD-1 may constitute a preexisting component of the biliary antimicrobial defense system.

Cholesterol hepatolithiasis with peribiliary cysts

A 78-year-old man was admitted to our clinic because of fatigue. Imaging modalities showed beaded stricture and dilation of the intrahepatic left segmental bile duct. Anomalous pancreatico-biliary ductal union and polycystic kidney disease were absent. Resection of the hepatic left lobe was performed. Grossly, cholesterol stones were impacted in the dilated intrahepatic large bile ducts, and multiple tiny cysts measuring 2-8 mm were noted in the peribiliary areas (peribiliary cysts). Histologically, the cholesterol hepatoliths consisted of cholesterol empty spaces and fibrinous materials, and, in places, foreign body giant cells were seen around the cholesterol crystals. The peribiliary cysts were lined by a layer of cuboidal epithelia. They were intimately intermingled with intrahepatic peribiliary glands, and a close association between the two components was recognized in some places. A mild degree of ascending cholangitis was noted. Bile duct anomalies including von-Meyenburg complexes and simple cysts were not recognized. Peribiliary cysts have been reported in various liver diseases, including portal hypertension, portal thrombosis, cirrhosis, hepatocellular carcinoma, and adult polycystic kidney disease. However, to the best of our knowledge, there have been no reports on peribiliary cysts developing in hepatolithiasis. The present case indicates that peribiliary cysts occur in cholesterol hepatolithiasis, and suggests that they are derived from cystic dilations of intrahepatic peribiliary glands.

Decrease of deleted in malignant brain tumour-1 (DMBT-1) expression is a crucial late event in intrahepatic cholangiocarcinoma

AIMS

To investigate the participation of DMBT-1, a candidate tumour suppressor gene, in the development of intrahepatic cholangiocarcinoma via intraductal papillary neoplasm of the liver (IPN-L) arising in hepatolithiasis. DMBT-1 plays a role in mucosal immune defence.

METHODS AND RESULTS

The expression of DMBT-1 was examined immunohistochemically in biliary epithelial cells in hepatolithiasis (n = 25), invasive and non-invasive cholangiocarcinoma associated with hepatolithiasis (n = 52), IPN-L with hepatolithiasis (n = 49), cholangiocarcinoma without hepatolithiasis (n = 32), and 10 normal control livers. DMBT-1 was expressed more frequently in the biliary epithelia of hepatolithiasis when compared with normal livers (P < 0.05). DMBT-1 expression was also frequent in IPN-L (57%) and non-invasive cholangiocarcinoma (79%). By contrast, DMBT-1 was decreased in invasive cholangiocarcinoma with and without hepatolithiasis (50% and 30%, respectively) (P < 0.05). The homozygous deletion of the DMBT-1 gene was recognized in four (20%) of 20 cholangiocarcinoma tissues and two (50%) of four cholangiocarcinoma cell lines, corresponding to the reduction of DMBT-1 expression. No deletion was detected in hepatolithiasis tissues.

CONCLUSION

DMBT-1 expression is increased in IPN-L and non-invasive cholangiocarcinoma as well as in biliary epithelia in hepatolithiasis. Decreased expression of DMBT-1 and homozygous deletion of the DMBT-1 gene in invasive cholangiocarcinoma suggest that they occur in the late stage of cholangiocarcinogenesis.

Expression of trefoil factor family 1, 2, and 3 peptide is augmented in hepatolithiasis

Trefoil factor family (TFF) 1, 2, and 3 is a mucin-associated protein involved in the maintenance of mucosal barrier and restitution of lining epithelial cells. In this study, the expression of TFF1, 2, and 3 and MUC mucins were examined immunohistochemically in hepatolithiasis and control livers. The expression of TFF1, 2, and 3 were augmented markedly in biliary mucosa in hepatolithiasis in coordinate with gel-forming mucin. TFF3 was detected in hepatic bile samples of hepatolithiasis. Augmented expression and secretion of TFF in biliary mucosa in hepatolithiasis may play a role in lithogenesis together with gel-forming mucin in addition to mucosal defense and repair.

Aberrant expression of CDX2 is closely related to the intestinal metaplasia and MUC2 expression in intraductal papillary neoplasm of the liver in hepatolithiasis

Intraductal papillary neoplasia of the liver (IPNL) frequently presents gastrointestinal metaplasia with aberrant expression of MUC2 and MUC5AC and oversecretion of mucin into the ductal lumen. In this study, the involvement of CDX2, a homeodomain protein involved in the regulation of intestinal development and differentiation, in the expression of MUC2 was examined in mucinous intrahepatic cholangiocarcinoma (ICC) (n=7) and IPNL with hepatolithiasis (n=19) with comparison to conventional ICC (n=11), and intraductal papillary mucinous tumor and invasive ductal carcinoma of the pancreas (n=9 and 11, respectively). A total of 33 cases of hepatolithiasis, extrahepatic biliary obstruction and normal livers were used as the control. Immunohistochemically, both MUC2 and MUC5AC were frequently expressed in mucinous ICC and IPNL, while expression of MUC2 was not seen in conventional ICC. The nuclear expression of CDX2 was closely associated with the expression of MUC2 in mucinous ICC and IPNL. This intimate association of MUC2 and CDX2 was confirmed by double immunostaining. The cytoplasmic CDX2 expression was frequent in the mucinous and the conventional ICC and pancreatic carcinoma, irrespective of MUC2 and MUC5AC expression. CDX2 mRNA was detected in neoplastic cells showing cytoplasmic as well as nuclear expression of CDX2 by reverse transcriptase-polymerase chain reaction. One IPMT expressed MUC2 associated with nuclear CDX2 expression, while the other IPMT and conventional pancreatic carcinoma expressed MUC5AC only. Aberrant expression of CDX2 is closely related to the overexpression of MUC2 in mucinous ICC and IPNL associated with hepatolithiasia, suggesting its role in intestinal differentiation and its association with carcinogenesis in these tumors.

Aberrant expression of trefoil factor family 1 in biliary epithelium in hepatolithiasis and cholangiocarcinoma

Stepwise progression of intrahepatic cholangiocarcinoma (ICC) has been proposed in hepatolithiasis. We examined the participation of trefoil factor family 1 (TFF1), which is critical for mucosal protection and tumor suppression in the stomach, in the development and progression of ICC. We used 16 livers of ICC with hepatolithiasis, 11 of biliary epithelial dysplasia with hepatolithiasis, 16 of hepatolithiasis without dysplasia or carcinoma, 18 of ICC without hepatolithiasis, and 39 control livers. TFF1 expression in the biliary epithelium was increased in hepatolithiasis compared with control livers (p < 0.01). In biliary epithelial dysplasia and noninvasive ICC with hepatolithiasis, TFF1 was extensively expressed and MUC5AC gastric mucin was usually colocalized with TFF1. However, TFF1 expression was significantly decreased in invasive ICC despite preserved expression of MUC5AC. A total of four missense mutations were detected: three in two noninvasive ICC with hepatolithiasis (28.6%) and one in invasive ICC (11%). Loss of heterozygosity of the TFF1 gene was not detectable. The decreased expression of TFF1 in invasive ICC may be explained by the methylation of the TFF1 promoter region. Up-regulation of TFF1 coupled with MUC5AC in biliary epithelium in hepatolithiasis, biliary epithelial dysplasia, and noninvasive ICC may reflect the gastric metaplasia and early neoplastic lesion. Under such conditions, decreased TFF1 expression may lead to increased cell proliferation and then to the invasive character of ICC.

Marked diffuse dilations of the biliary tree associated with intrahepatic calculi, biliary sludges and a mucinous cyst of the pancreatic head in a 99-year-old woman

A 99-year-old woman was admitted to Shizuoka Shimizu Municipal Hospital because of fever and anasarca. Imaging and laboratory tests showed pneumonia, urinary tract infection, and cardiac failure. The patient died 20 days after admission. An autopsy revealed marked diffuse dilations of the biliary tree ranging from the lower common bile duct to intrahepatic bile ducts. Intrahepatic calcium bilirubinate stones and biliary sludges were recognized within the dilated bile ducts. A unilocular cyst (2 cm in diameter) was present in the pancreatic head adjacent to the lower common bile duct, and it appeared to compress the common bile duct. Histologically, the walls of the dilated biliary tree showed proliferation of peribiliary glands, fibrosis, and infiltration of lymphocytes and neutrophils (cholangitis). The lumens of the dilated biliary ducts contained neutral and acidic mucins, fibrinous materials, bacteria, neutrophils, and Aspergillus fungi, in addition to the calculi and sludges. The background liver showed atrophy (400 g). The pancreatic unilocular cyst was composed of mucous columnar cells with a few infoldings, and the pancreas also showed foci of mucinous duct hyperplasia and ectasia; the pathological diagnosis of the cyst was cystic dilations of a pancreatic duct branch (mucinous ductal ectasia or mucinous cyst). Other lesions included aspiration pneumonia, emaciation, atrophy of systemic organs, gastric leiomyoma, serous cystadenoma of the right ovary, and arteriosclerotic nephrosclerosis. The present case suggests that a mucinous cyst of the pancreas may compress the biliary tree and lead to marked diffuse dilations of the biliary tree. Alternatively, the dilations of the bile ducts may be associated with aging or may be of congenital origin. The dilated bile ducts may, in turn, give rise to bacterial and fungal cholangitis and formation of biliary sludges and intrahepatic calcium bilirubinate stones.

Prostaglandin E receptors in bile ducts of hepatolithiasis patients and the pathobiological significance for cholangitis

BACKGROUND & AIMS

In hepatolithiasis, chronic proliferative cholangitis may influence the progression of the disease. Prostaglandin (PG) E(2) experimentally causes morphologic changes to intrahepatic bile ducts, analogous to the changes found in cholangitis. This study was designed to gain an understanding of the involvement of PGE(2) and PGE receptor (EP) subtypes in the development of cholangitis.

METHODS

The expression levels of secretory-type group IIA phospholipase A(2) (sPLA(2)-IIA) and cyclooxygenase (COX)-2 as well as EP subtypes were determined in the bile ducts with change of cholangitis. In in vitro experiments, growth promotion and mucin secretagogue properties of biliary epithelial cells in response to EP-selective agonists or antagonists were studied.

RESULTS

The messenger RNA (mRNA) level of sPLA(2)-IIA and the protein and mRNA levels of COX-2 were significantly increased in the bile ducts of patients with hepatolithiasis compared with the levels of the bile ducts of control subjects. These changes were associated with a concomitant increase in PGE(2) and total mucin concentrations in the bile. The mRNAs of EP subtypes EP(2), EP(3), and EP(4) but not EP(1) were amplified in the bile ducts. Treatment with an EP(4)-selective agonist (ONO-AE1-329) caused a dose-dependent increase in DNA synthesis, colony number, and mucin secretion in the cells. Conversely, treatment with an EP(4)-selective antagonist (ONO-AE3-208) abolished the biological effects of PGE(2) on the cells.

CONCLUSIONS

In hepatolithiasis, an enhanced synthesis of sPLA(2)-/COX-2-derived PGE(2) and its actions mediated via the EP(4) receptor in the bile ducts may be of pathobiological significance for chronic proliferative cholangitis.

Lipopolysaccharide induces overexpression of MUC2 and MUC5AC in cultured biliary epithelial cells: possible key phenomenon of hepatolithiasis

Bacterial infection, bile stasis, mucin hypersecretion, and an alteration of the mucin profile such as an aberrant expression of gel-forming apomucin (MUC2 and MUC5AC) in the intrahepatic biliary tree are thought to be important in the lithogenesis of hepatolithiasis. So far, there have been no detailed studies linking bacterial infection to altered mucus secretion of biliary epithelium. In this study, the influence of lipopolysaccharide (LPS), a bacterial component, on apomucin expression in cultured murine biliary epithelial cells was examined with emphasis on the participation of tumor necrosis factor (TNF)-alpha. It was found that LPS up-regulated the expression of MUC2 and MUC5AC in cultured murine biliary epithelial cells. LPS also induced the expression of TNF-alpha in biliary epithelial cells and its secretion into the culture medium. The up-regulation of these apomucins was inhibited by pretreatment with TNF-alpha antibody. TNF-alpha alone also induced the overexpression of MUC2 and MUC5AC in cultured biliary epithelial cells. This overexpression was inhibited by pretreatment with calphostin C, an inhibitor of protein kinase C. These findings suggest that LPS can induce overexpression of MUC2 and MUC5AC in biliary epithelial cells via synthesis of TNF-alpha and activation of protein kinase C. This mechanism might be involved in the lithogenesis of hepatolithiasis.

Suppression of proliferative cholangitis by E2F decoy oligodeoxynucleotide

BACKGROUND

Proliferative cholangitis (PC) associated with hepatolithiasis results in stricture of the main bile ducts and is a major cause of residual and/or recurrent stones after repeated treatment for hepatolithiasis. The transcription factor E2F controls the expression of several genes involved in cell proliferation. The aim of this study was to inhibit PC using cytostatic gene therapy by transferring fusigenic anionic liposome-hemagglutinating virus of Japan (HVJ-anionic liposome) complexes containing a synthetic double-stranded oligodeoxynucleotide with high affinity for E2F (E2F decoy).

MATERIALS AND METHODS

PC was induced by introducing a fine nylon thread into the bile duct in a rat model. HVJ-anionic liposomes containing the E2F decoy were administered directly into the biliary tract. HVJ-anionic liposomes containing a missense oligodeoxynucleotide (scramble decoy) were also given as a control. The count of peribiliary glands in the bile duct, 5'-bromodeoxyuridine (BrdU) labeling index, and immunohistochemical staining for proliferating cell nuclear antigen (PCNA) in the bile duct were compared among untransfected, scramble decoy-transfected, and E2F decoy-transfected rats.

RESULTS

E2F decoy-transfected bile ducts showed inhibition of the papillary proliferation of the biliary epithelium and peribiliary gland hyperplasia. BrdU incorporation and PCNA expression in the bile ducts were inhibited in E2F decoy-transfected rats.

CONCLUSION

Our cytostatic gene therapy approach using direct E2F decoy transfer into the biliary tract suppressed PC in a rat model and may offer an effective therapeutic option for reducing recurrence following treatment for hepatolithiasis.

Tumor vessel: a valuable cholangioscopic clue of malignant biliary stricture

BACKGROUND

An irregularly dilated and tortuous vessel, the so-called tumor vessel, is considered to be one of the cholangioscopic features that suggest biliary malignancy. This is a prospective analysis of the presence of a tumor vessel as a finding that discriminates between benign and malignant biliary strictures.

METHODS

From August 1997 to August 1998, a total of 63 patients with biliary strictures diagnosed with endoscopic retrograde cholangiography or percutaneous transhepatic cholangiography obtained during percutaneous transhepatic biliary drainage tube placement were included in this study. Strictures were characterized as benign or malignant based on the observation of tumor vessels. The results were compared with those of percutaneous transhepatic cholangiography-guided biopsy and final diagnosis.

RESULTS

Forty-one patients were confirmed to have malignant strictures and 22 had benign biliary strictures. Cancer was confirmed by histopathologic evaluation of biopsies in 33 of 41 patients with malignancy (80.4%). Tumor vessel was seen in 25 of 41 patients with malignancy (61%). No patients with benign stricture had tumor vessels. Of the 8 patients with negative percutaneous transhepatic cholangioscopy-guided biopsies but with a final diagnosis of malignancy, 6 had tumor vessels. Combining the observation of tumor vessel and percutaneous transhepatic cholangiography-guided biopsy resulted in a diagnosis of malignancy in 39 of 41 patients (96%) and significantly increased the rate of preoperative diagnosis when compared with percutaneous transhepatic cholangiography-guided biopsy or presence of tumor vessel alone (p<0.05).

CONCLUSION

The presence of tumor vessel may be a valuable cholangioscopic finding that indicates the presence of a malignant biliary stricture. The combination of tumor vessel observation and percutaneous transhepatic cholangiography-guided biopsy may improve the preoperative diagnosis of malignancy.

Bacteriology and antimicrobial choice in hepatolithiasis

BACKGROUND AND AIMS

Hepatolithiasis is prevalent in southeast Asia and presents a difficult management problem. Acute repeated episodes of cholangitis are frequently manifested in patients with hepatolithiasis. Without proper treatment, such infection can lead to liver abscess, secondary biliary cirrhosis, portal hypertension, and death from sepsis or hepatic failure. In addition to clearance of the stones and relief of bile stasis either by surgery or by interventional radiologic manipulation, effective antimicrobial therapy also plays a crucial role in the treatment of patients with hepatolithiasis. The aim of this study is to clarify the bacteriology in hepatolithiasis and to provide the information for an appropriate antimicrobial choice.

METHODS

From July 1993 to June 1996, 150 patients with hepatolithiasis underwent surgical intervention. Bile specimens were routinely obtained by syringe aspiration from common bile duct. The syringe was immediately capped, and the bile was subsequently cultured for both aerobes and anaerobes.

RESULTS

Bacteria were present in the bile of all patients. The bacteria most frequently found were gram-negative bacteria such as Klebsiella sp, Escherichia coli, and Pseudomonas sp, and the gram-positive Enterococcus sp. Bacteroides sp were the most frequently found anaerobes.

CONCLUSIONS

This study demonstrated the close relationship between acute cholangitis in hepatolithiasis and enteric bacteria and also displayed the detailed antibiotic sensitivity results. Armed with this fruitful information, we believe the antibiotic treatment for acute cholangitis in hepatolithiasis should first aim at enteric bacteria and be adjusted later according to the results of bacteriologic cultures and clinical situation to achieve an effective microbial control.

The significance of hepatectomy for primary intrahepatic stones

The objective of this study was to evaluate the significance of performing hepatectomy for primary intrahepatic stones. Observations on the morphology of the bile ducts, histopathological findings of the excised liver, and treatment results were reviewed in 29 of 35 patients with primary intrahepatic stones. The remaining 6 patients (17.1%) were excluded because they had intrahepatic cholangiocarcinoma. The subjects were classified into two groups according to the morphological characteristics of the bile ducts; one group comprised 25 patients having strictures in the central bile duct, and another group comprised 4 patients having no biliary stricture, but a localized dilatation in the distal bile duct. Calcium bilirubinate stones were found in all the patients with a biliary stricture, whereas cholesterol stones were found in those without a biliary stricture. Hepatectomy was performed in 25 of the 29 patients (86.2%), the results of which were excellent. In fact, during the past 10 years, no postoperative complications have occurred, nor have there been any retained or recurrent stones. Moreover, the postoperative hospitalization period was as short as 15.3 days. The findings of this study indicate that hepatectomy allows treatment for primary intrahepatic stones to be completed within a short period of time without incurring serious postoperative complications, and serves as a useful prophylactic technique for recurrent stones.

Aberrant expression of stem cell factor on biliary epithelial cells and peribiliary infiltration of c-kit-expressing mast cells in hepatolithiasis and primary sclerosing cholangitis: a possible contribution to bile duct fibrosis

Hepatolithiasis and primary sclerosing cholangitis (PSC) are intractable chronic biliary diseases. In hepatolithiasis, bilirubin-calcium stones are packed in multiple irregularly dilated intrahepatic bile ducts. In PSC, small bilirubin-calcium stones develop terminally. The progressive periductal fibrosis with dilated and stenotic bile ducts in these two diseases may play a role in their incurability. This immunohistochemical study has investigated the expression of some factors that might be involved in fibrogenesis in hepatolithiasis and PSC. Many mast cells positive for c-kit were found in the periductal and ductal fibrosis around the intrahepatic large bile ducts and also around the proliferative peribiliary glands. These mast cells also expressed basic fibroblast growth factor and/or tumour necrosis factor-alpha, which are known as fibrogenetic factors. It was of interest that the aberrant expression of stem cell factor (SCF), a ligand of c-kit, was demonstrated on biliary epithelia of the dilated and stenotic bile ducts showing periductal fibrosis and inflammation and also of the proliferated peribiliary glands in hepatolithiasis and PSC, while no such expression was seen in non-affected bile ducts in hepatolithiasis or in the bile ducts in normal livers. Some of the infiltrating mononuclear cells around the SCF-expressing bile ducts were also positive for SCF. It seems likely that aberrantly expressed SCF on biliary epithelial cells accumulates and stimulates mast cells via the c-kit receptor and that these up-regulated mast cells induce progressive periductal and portal fibrosis by displaying fibrogenetic factors in hepatolithiasis and PSC.

Secretory low-molecular-weight phospholipases A2 and their specific receptor in bile ducts of patients with intrahepatic calculi: factors of chronic proliferative cholangitis

Intrahepatic calculi is characterized by an intractable course and frequent recurrences, requiring multiple operative interventions. Chronic proliferative cholangitis, an active and long-standing inflammation of the stone-containing bile ducts with the hyperplasia of epithelia and the proliferation of the duct-associated mucus glands, may underlie the complex nature of the disease. In terms of the pathophysiology, interest has been focused on the role of secretory low-molecular-weight phospholipases A2 (sPLA2s) as inflammatory mediators or factors modulating cell functions via their specific sPLA2-receptor, and also on the production and secretion of altered mucin molecules from the inflamed bile ducts. In search of factors involving chronic proliferative cholangitis, the sPLA2 isoforms in the bile such as the pancreatic-type sPLA2 (group IB sPLA2) and the arthritic-type sPLA2 (group IIA sPLA2), were assayed to correlate protein masses of the sPLA2s with alterations in biliary composition. Furthermore, the steady-state messenger RNA (mRNA) levels of the sPLA2s, the membrane-bound sPLA2-receptor, cystic fibrosis transmembrane conductance regulator (CFTR), and mucin core polypeptide (MUC) genes in the bile ducts were assayed by reverse- transcriptase polymerase chain reaction (RT-PCR). Immunoreactive sPLA2-IB and sPLA2-IIA levels were significantly higher in the bile from the stone-containing hepatic ducts (2315 +/- 677 for sPLA2-IB; 281 +/- 42 for sPLA2-IIA ng/dL, mean +/- SEM; n = 20) than in the ductal bile from gallbladder stone patients (609 +/- 92, P <.01; 22 +/- 2, P <.01; n = 24). The increased sPLA2 levels were associated with a concomitant increase in lysophosphatidylcholine, prostaglandin E2 (PGE2), and total mucin concentrations. The affected bile ducts showed an increased mRNA level of sPLA2-IB and sPLA2-IIA compared with the ducts from control subjects, in whom the mRNAs of the sPLA2-receptor and other sPLA2 isoforms, such as groups V and X sPLA2s, were coincidently expressed. Reflecting the increased amounts of total biliary mucins, the affected ducts showed an increase in mRNA levels of CFTR as well as MUC2, MUC3, MUC5AC, MUC5B, and MUC6 compared with the ducts from control subjects. In intrahepatic calculi, an enhanced expression of the sPLA2s and their possible cross-talk via sPLA2-receptor may be of pathophysiological significance for the chronic proliferative cholangitis, in association with the enhanced CFTR expression and the alterations in mucin gene expression in the bile ducts, probably through potentiating arachidonate metabolism with associated biliary alterations favoring growth of preexisting stones and even further progressions.

Generation of monoclonal antibodies to murine bile duct epithelial cells: identification of annexin V as a new marker of small intrahepatic bile ducts

Biliary epithelial cells (BECs) are distributed along the length of both the extrahepatic and intrahepatic biliary tree, but have distinctly different phenotypes and functions according to their anatomical location. It has been reasoned that the distinct appearance of pathogenic lesions in different biliary diseases may be associated with the expression of distinct proteins. These data prompted us to immunize rats with cultured murine BECs with the objective of determining if there are unique antigens on BECs. Of the 45 monoclonal antibodies (mAbs) produced, 12 mAbs (MBEC 1-12) were selected for detailed study based on their classification into three major groups. These groups included four antibodies (MBEC 1-4) that reacted in a staining pattern typical of mucin. A second group of mAbs, MBECs 5 to 8, reacted strongly along the biliary tract and by immunoblot analysis, reacted with several bands ranging from 44 kd to 64 kd. These antibodies were considered as markers of pan BECs and their staining pattern proved similar to that of a control polyclonal pan-cytokeratin. The final group of mAbs, MBECs 9 to 12, recognized a 36-kd antigen using lysates of murine BECs. These antibodies also predominantly stained small peripheral bile ducts. The reactive antigen was purified by immunoprecipitation and microsequenced; the peptides sequenced showed 100% homology with murine annexin V. The identification of annexin V with predominantly intrahepatic bile ducts, is of significant interest because of the multiple roles of annexin V, including that of membrane cytoskeletal interactions during transport and apoptosis.