Implantation of a Tissue-Engineered Neo-Bile Duct in Domestic Pigs

2015 ◽  
Vol 56 (1-2) ◽  
pp. 61-75 ◽  
Author(s):  
Benjamin Struecker ◽  
Karl-Herbert Hillebrandt ◽  
Nathanael Raschzok ◽  
Korinna Jöhrens ◽  
Antje Butter ◽  
...  

Background: Extrahepatic bile duct injuries remain severe complications during cholecystectomies and often require reconstruction by bilioenteric anastomosis (i.e., hepaticojejunostomy), which comes with further long-term complications (e.g., recurring ascending cholangitis, secondary biliary cirrhosis). In the case of inherent extrahepatic biliary atresia or during liver transplant, artificial or engineered bile ducts could allow novel surgical strategies without the need for hepaticojejunostomy. Methods: We present data on the implantation of in vitro-generated neo-bile ducts in 5 domestic pigs. The neo-bile ducts were engineered through decellularization of allogeneic blood vessels and recellularization with autologous cholangiocytes. On postoperative days 0, 1, 7, and 14, blood samples were taken and analyzed (aspartate aminotransferase, alanine aminotransferase, bilirubin, alkaline phosphatase, creatinine, and leukocytes). Magnetic resonance cholangiopancreatography was performed on postoperative day 14 on 1 pig. Fourteen days after implantation, the pigs were sacrificed and the bile ducts were explanted. Results: All pigs survived the complete study period without severe complications. None of the pigs showed signs of biliary leakage or peritonitis. The neo-bile ducts were infiltrated by neutrophils, and neoangiogenesis was observed around and into the implanted tissue. Conclusion: We present a novel strategy for extrahepatic bile duct replacement by implantation of an autologous neo-bile duct generated ex vivo. Whether the presented technique allows the long-term replacement of native bile ducts must be further evaluated.

2019 ◽  
Author(s):  
Gauri Khandekar ◽  
Jessica Llewellyn ◽  
Alyssa Kriegermeier ◽  
Orith Waisbourd-Zinman ◽  
Nicolette Johnson ◽  
...  

AbstractBackground & AimsThe extrahepatic bile duct is the primary tissue initially affected by the cholangiopathy biliary atresia. Biliary atresia affects neonates exclusively and current animal models suggest that the developing bile duct is uniquely susceptible to damage. In this study, we aimed to define the anatomical and functional differences between the neonatal and adult mouse extrahepatic bile ducts.MethodsWe studied mouse passaged cholangiocytes, mouse BALB/c neonatal and adult primary cholangiocytes and isolated extrahepatic bile ducts, and a collagen reporter mouse. Methods included transmission electron microscopy, lectin staining, immunostaining, rhodamine uptake assays, bile acid toxicity assays, and in vitro modeling of the matrix.ResultsThe cholangiocyte monolayer of the neonatal extrahepatic bile duct was immature, lacking the uniform apical glycocalyx and mature cell-cell junctions typical of adult cholangiocytes. Functional studies showed that the glycocalyx protected against bile acid injury and that neonatal cholangiocyte monolayers were more permeable than adult monolayers. In adult ducts, the submucosal space was filled with collagen I, elastin, hyaluronic acid, and proteoglycans. In contrast, the neonatal submucosa had little collagen I and elastin, although both increased rapidly after birth. In vitro modeling suggested that the composition of the neonatal submucosa relative to the adult submucosa led to increased diffusion of bile. A Col-GFP reporter mouse showed that cells in the neonatal but not adult submucosa were actively producing collagen.ConclusionWe identified four key differences between the neonatal and adult extrahepatic bile duct. We showed that these features may have functional implications, suggesting the neonatal extrahepatic bile ducts are particularly susceptible to injury and fibrosis.Lay SummaryBiliary atresia is a disease that affects newborns and is characterized by extrahepatic bile duct injury and obstruction with resulting liver injury. We identify four key differences between the epithelial and submucosal layers of the neonatal and adult extrahepatic bile duct and show that these may render the neonatal duct particularly susceptible to injury.HighlightsThe apical glycocalyx is thin and patchy in neonatal compared to adult cholangiocytesNeonatal cholangiocytes have immature cell-cell junctions and increased permeabilityThe neonatal submucosal space has minimal collagen I or elastinThe neonatal submucosal space contains many actively collagen-secreting cellsGraphical abstract


Author(s):  
Fatima Aerts-Kaya

: In contrast to their almost unlimited potential for expansion in vivo and despite years of dedicated research and optimization of expansion protocols, the expansion of Hematopoietic Stem Cells (HSCs) in vitro remains remarkably limited. Increased understanding of the mechanisms that are involved in maintenance, expansion and differentiation of HSCs will enable the development of better protocols for expansion of HSCs. This will allow procurement of HSCs with long-term engraftment potential and a better understanding of the effects of the external influences in and on the hematopoietic niche that may affect HSC function. During collection and culture of HSCs, the cells are exposed to suboptimal conditions that may induce different levels of stress and ultimately affect their self-renewal, differentiation and long-term engraftment potential. Some of these stress factors include normoxia, oxidative stress, extra-physiologic oxygen shock/stress (EPHOSS), endoplasmic reticulum (ER) stress, replicative stress, and stress related to DNA damage. Coping with these stress factors may help reduce the negative effects of cell culture on HSC potential, provide a better understanding of the true impact of certain treatments in the absence of confounding stress factors. This may facilitate the development of better ex vivo expansion protocols of HSCs with long-term engraftment potential without induction of stem cell exhaustion by cellular senescence or loss of cell viability. This review summarizes some of available strategies that may be used to protect HSCs from culture-induced stress conditions.


2021 ◽  
Vol 3 (2) ◽  
pp. 20-24
Author(s):  
Aldona Wybraniec-Zaręba ◽  
Julia Tuchalska-Czuroń ◽  
Gabriela Półtorak-Szymczak ◽  
Mariusz Furmanek ◽  
Jerzy Walecki ◽  
...  

Primary sclerosing cholangitis (PSC) is a chronic liver disease in which there are inflammation and scarring of the bile ducts leading to fibrosis, destruction and narrowing of the bile ducts, resulting in cholestasis. In the long run, PSC can cause liver cirrhosis and failure. In clinical practice, the diagnosis of PSC is generally based on blood tests and imaging studies (currently preferably magnetic resonance cholangiopancreatography). To make a diagnosis of PSC it is necessary to exclude secondary causes of sclerosing cholangitis. The most common MRI features of PSC concerning bile ducts are: bile duct dilatation, beading, extrahepatic bile duct stenosis, wall enhancement and thickening. The most common MRI features of PSC concerning hepatic parenchyma are: rounded shape of the liver caused by hypertrophy of caudate lobe and left liver lobe, atrophy of the right lobe, enlargement of portal and/or portacaval lymph nodes, peripheral parenchymal inflammation, wedge-shaped confluent fibrosis, heterogeneity of the liver parenchyma, periportal oedema, cirrhosis with indirect signs of portal hypertension such as splenomegaly, ascites and collateral vasculature.


Author(s):  
M. A. Shorikov ◽  
O. N. Sergeeva ◽  
M. G. Lapteva ◽  
N. A. Peregudov ◽  
B. I. Dolgushin

Proximal extrahepatic bile ducts are the biliary tree segment within formal boundaries from cystic ductcommon hepatic duct junction to sectoral hepatic ducts. Despite being a focus of attention of diagnostic and interventional radiologists, endoscopists, hepatobiliary surgeons and transplantologists they weren’t comprehensively described in available papers. The majority of the authors regard bile duct confluence as a group of merging primitively arranged tubes providing bile flow. The information on the proximal extrahepatic bile duct embryonal development, variant anatomy, innervation, arterial, venous and lymphatic supply is too general and not detailed. The present review brought together and systemized exiting to the date data on anatomy and function of this biliary tract portion. Unique, different from the majority of hollow organs organization of the proximal extrahepatic bile duct adapts them to the flow of the bile, i.e. viscous aggressive due to pH about 8.0 and detergents fluid, under higher wall pressure than in other parts of biliary tree. 


Blood ◽  
1999 ◽  
Vol 94 (5) ◽  
pp. 1623-1636 ◽  
Author(s):  
Chu-Chih Shih ◽  
Mickey C.-T. Hu ◽  
Jun Hu ◽  
Jeffrey Medeiros ◽  
Stephen J. Forman

Abstract We have developed a stromal-based in vitro culture system that facilitates ex vivo expansion of transplantable CD34+thy-1+ cells using long-term hematopoietic reconstitution in severe combined immunodeficient-human (SCID-hu) mice as an in vivo assay for transplantable human hematopoietic stem cells (HSCs). The addition of leukemia inhibitory factor (LIF) to purified CD34+ thy-1+ cells on AC6.21 stroma, a murine bone marrow–derived stromal cell line, caused expansion of cells with CD34+ thy-1+ phenotype. Addition of other cytokines, including interleukin-3 (IL-3), IL-6, granulocyte-macrophage colony-stimulating factor, and stem cell factor, to LIF in the cultures caused a 150-fold expansion of cells retaining the CD34+ thy-1+ phenotype. The ex vivo–expanded CD34+ thy-1+ cells gave rise to multilineage differentiation, including myeloid, T, and B cells, when transplanted into SCID-hu mice. Both murine LIF (cannot bind to human LIF receptor) and human LIF caused expansion of human CD34+ thy-1+ cells in vitro, suggesting action through the murine stroma. Furthermore, another human HSC candidate, CD34+ CD38− cells, shows a similar pattern of proliferative response. This suggests thatex vivo expansion of transplantable human stem cells under this in vitro culture system is a general phenomenon and not just specific for CD34+ thy-1+ cells.


2008 ◽  
Vol 74 (1) ◽  
pp. 87-90 ◽  
Author(s):  
Niraj J. Gusani ◽  
J. Wallis Marsh ◽  
Michael A. Nalesnik ◽  
Mitchell E. Tublin ◽  
T. Clark Gamblin

Extrahepatic bile duct tumors, 80 per cent of which are adenocarcinomas, are rare neoplasms accounting for less than two per cent of all cancers. Carcinoid tumor of the extrahepatic bile ducts is a reportable lesion, with only approximately 50 cases described in the literature since 1959. We present a case of a primary extrahepatic bile duct carcinoid tumor resected for cure with the longest reported follow-up time (11 years) after surgery. We also summarize the existing literature with regard to this rare tumor. Our case lends strong support to the notion that extrahepatic biliary carcinoids are generally indolent lesions that, if aggressively resected, can result in excellent long-term survival. Complete excision with clear margins seems to provide the best chance of obtaining long-term survival and cure.


Blood ◽  
2000 ◽  
Vol 96 (5) ◽  
pp. 1748-1755 ◽  
Author(s):  
David Bryder ◽  
Sten E. W. Jacobsen

Abstract Although long-term repopulating hematopoietic stem cells (HSC) can self-renew and expand extensively in vivo, most efforts at expanding HSC in vitro have proved unsuccessful and have frequently resulted in compromised rather than improved HSC grafts. This has triggered the search for the optimal combination of cytokines for HSC expansion. Through such studies, c-kit ligand (KL), flt3 ligand (FL), thrombopoietin, and IL-11 have emerged as likely positive regulators of HSC self-renewal. In contrast, numerous studies have implicated a unique and potent negative regulatory role of IL-3, suggesting perhaps distinct regulation of HSC fate by different cytokines. However, the interpretations of these findings are complicated by the fact that different cytokines might target distinct subpopulations within the HSC compartment and by the lack of evidence for HSC undergoing self-renewal. Here, in the presence of KL+FL+megakaryocyte growth and development factor (MGDF), which recruits virtually all Lin−Sca-1+kit+ bone marrow cells into proliferation and promotes their self-renewal under serum-free conditions, IL-3 and IL-11 revealed an indistinguishable ability to further enhance proliferation. Surprisingly, and similar to IL-11, IL-3 supported KL+FL+MGDF-induced expansion of multilineage, long-term reconstituting activity in primary and secondary recipients. Furthermore, high-resolution cell division tracking demonstrated that all HSC underwent a minimum of 5 cell divisions, suggesting that long-term repopulating HSC are not compromised by IL-3 stimulation after multiple cell divisions. In striking contrast, the ex vivo expansion of murine HSC in fetal calf serum-containing medium resulted in extensive loss of reconstituting activity, an effect further facilitated by the presence of IL-3.


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