Peribiliary Gland Niche Participates in Biliary Tree Regeneration in Mouse and in Human Primary Sclerosing Cholangitis.

BACKGROUND AND AIMS: Mechanisms underlying the repair of extrahepatic biliary tree (EHBT) after injury have been scarcely explored. The aims of this study were to evaluate, by using a lineage tracing approach, the contribution of peribiliary gland (PBG) niche in the regeneration of EHBT after damage and to evaluate, in vivo and in vitro, the signaling pathways involved. APPROACH AND RESULTS: Bile duct injury was induced by the administration of 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC) diet for 14 days to Krt19Cre TdTomatoLSL mice. Human biliary tree stem/progenitor cells (BTSC) within PBGs were isolated from EHBT obtained from liver donors. Hepatic duct samples (n = 10) were obtained from patients affected by primary sclerosing cholangitis (PSC). Samples were analyzed by histology, immunohistochemistry, western blotting, and polymerase chain reaction. DDC administration causes hyperplasia of PBGs and periductal fibrosis in EHBT. A PBG cell population (Cytokeratin19- /SOX9+ ) is involved in the renewal of surface epithelium in injured EHBT. The Wnt signaling pathway triggers human BTSC proliferation in vitro and influences PBG hyperplasia in vivo in the DDC-mediated mouse biliary injury model. The Notch signaling pathway activation induces BTSC differentiation in vitro toward mature cholangiocytes and is associated with PBG activation in the DDC model. In human PSC, inflammatory and stromal cells trigger PBG activation through the up-regulation of the Wnt and Notch signaling pathways. CONCLUSIONS: We demonstrated the involvement of PBG cells in regenerating the injured biliary epithelium and identified the signaling pathways driving BTSC activation. These results could have relevant implications on the pathophysiology and treatment of cholangiopathies.

Neoplastic Transformation of the Peribiliary Stem Cell Niche in Cholangiocarcinoma Arisen in Primary Sclerosing Cholangitis.

Primary sclerosing cholangitis (PSC) is a chronic inflammatory cholangiopathy frequently complicated by cholangiocarcinoma (CCA). Massive proliferation of biliary tree stem/progenitor cells (BTSCs), expansion of peribiliary glands (PBGs), and dysplasia were observed in PSC. The aims of the present study were to evaluate the involvement of PBGs and BTSCs in CCA which emerged in PSC patients. Specimens from normal liver (n = 5), PSC (n = 20), and PSC-associated CCA (n = 20) were included. Samples were processed for histology, immunohistochemistry, and immunofluorescence. In vitro experiments were performed on human BTSCs, human mucinous primary CCA cell cultures, and human cholangiocyte cell lines (H69). Our results indicated that all CCAs emerging in PSC patients were mucin-producing tumors characterized by PBG involvement and a high expression of stem/progenitor cell markers. Ducts with neoplastic lesions showed higher inflammation, wall thickness, and PBG activation compared to nonneoplastic PSC-affected ducts. CCA showed higher microvascular density and higher expression of nuclear factor kappa B, interleukin-6, interleukin-8, transforming growth factor ß, and vascular endothelial growth factor-1 compared to nonneoplastic ducts. CCA cells were characterized by a higher expression of epithelial-to-mesenchymal transition (EMT) traits and by the absence of primary cilia compared to bile ducts and PBG cells in controls and patients with PSC. Our in vitro study demonstrated that lipopolysaccharide and oxysterols (PSC-related stressors) induced the expression of EMT traits, the nuclear factor kappa B pathway, autophagy, and the loss of primary cilia in human BTSCs. Conclusion: CCA arising in patients with PSC is characterized by extensive PBG involvement and by activation of the BTSC niche in these patients, the presence of duct lesions at different stages suggests a progressive tumorigenesis.

Progenitor cell niches in the human pancreatic duct system and associated pancreatic duct glands: an anatomical and immunophenotyping study.

Pancreatic duct glands (PDGs) are tubule-alveolar glands associated with the pancreatic duct system and can be considered the anatomical counterpart of peribiliary glands (PBGs) found within the biliary tree. Recently, we demonstrated that endodermal precursor niches exist fetally and postnatally and are composed functionally of stem cells and progenitors within PBGs and of committed progenitors within PDGs. Here we have characterized more extensively the anatomy of human PDGs as novel niches containing cells with multiple phenotypes of committed progenitors. Human pancreata (n = 15) were obtained from cadaveric adult donors. Specimens were processed for histology, immunohistochemistry and immunofluorescence. PDGs were found in the walls of larger pancreatic ducts (diameters > 300 µm) and constituted nearly 4% of the duct wall area. All of the cells identified were negative for nuclear expression of Oct4, a pluripotency gene, and so are presumably committed progenitors and not stem cells. In the main pancreatic duct and in large interlobular ducts, Sox9(+) cells represented 5-30% of the cells within PDGs and were located primarily at the bottom of PDGs, whereas rare and scattered Sox9(+) cells were present within the surface epithelium. The expression of PCNA, a marker of cell proliferation, paralleled the distribution of Sox9 expression. Sox9(+) PDG cells proved to be Pdx1(+) /Ngn3(+/-) /Oct4A(-) . Nearly 10% of PDG cells were positive for insulin or glucagon. Intercalated ducts contained Sox9(+) /Pdx1(+) /Ngn3(+) cells, a phenotype that is presumptive of committed endocrine progenitors. Some intercalated ducts appeared in continuity with clusters of insulin-positive cells organized in small pancreatic islet-like structures. In summary, PDGs represent niches of a population of Sox9(+) cells exhibiting a pattern of phenotypic traits implicating a radial axis of maturation from the bottoms of the PDGs to the surface of pancreatic ducts. Our results complete the anatomical background that links biliary and pancreatic tracts and could have important implications for the common patho-physiology of biliary tract and pancreas.

Activation of biliary tree stem cells within peribiliary glands in primary sclerosing cholangitis.

BACKGROUND & AIMS: Primary sclerosing cholangitis (PSC) is characterised by fibro-stenosing strictures involving extrahepatic and/or large intrahepatic bile ducts. Mechanisms leading to bile duct injury are poorly understood. We aimed to study the biliary tree stem cell compartment located in peribiliary glands of extrahepatic and large intrahepatic bile ducts and its role in the pathogenesis of biliary fibrosis in PSC. METHODS: Specimens containing extrahepatic or large intrahepatic bile ducts were obtained from normal liver (n=6), liver explants from patients with PSC (n=11), and primary biliary cirrhosis (n=6). Specimens were processed for histology, immunohistochemistry and immunofluorescence. RESULTS: In PSC samples, progressive hyperplasia and mucinous metaplasia of peribiliary glands were observed in large ducts with fibrosis, but not in inflamed ducts without fibrosis. Peribiliary gland hyperplasia was associated with progressive biliary fibrosis and the occurrence of dysplastic lesions. Hyperplasia of peribiliary glands was determined by the expansion of biliary tree stem cells, which sprouted towards the surface epithelium. In PSC, peribiliary glands and myofibroblasts displayed enhanced expression of Hedgehog pathway components. Peribiliary glands in ducts with onion skin-like fibrosis expressed epithelial-to-mesenchymal transition traits associated with components of Hedgehog pathway, markers of senescence and autophagy. CONCLUSIONS: The biliary tree stem cell compartment is activated in PSC, its activation contributes to biliary fibrosis, and is sustained by the Hedgehog pathway. Our findings suggest a key role for peribiliary glands in the progression of bile duct lesions in PSC and could explain the associated high risk of cholangiocarcinoma.

Role of BK virus infection in end-stage renal disease patients waiting for kidney transplantation--viral replication dynamics from pre- to post-transplant.

We report the prevalence of BK virus (BKV) infection before renal transplantation and the dynamics of BKV viremia from pre- to post-transplantation. We assessed 60 kidney transplanted patients from a single cohort in Italy, treated with identical immunosuppressive therapy, for BK viremia at pre-transplantation, 12 h, and three and six months post-transplantation. Polymerase chain reaction showed that the prevalence of plasma BKV replication--considered a marker of infection--was 20% in pre-transplant patients. All pre-transplant-positive patients remained positive post-transplant, whereas the majority of pre-transplant-negative patients remained negative. Viremia dynamics classification revealed three clusters of patients: Cluster A++, pre-transplant-positive patients (20%) who tested positive at least once post-transplant; Cluster B-+, pre-transplant-negative patients (28%) who tested positive at least once post-transplant; and Cluster C- -, pre-transplant-negative patients (52%) who remained negative throughout. These clusters presented significant differences related to the prevalence of substantially positive patients with high plasma viral load (>10(3) copies/mL) in cluster A, but not in donors' or grafts' characteristics. We suggest that pre-transplant viral status should be considered as an additional risk factor for post-transplant BKV replication. Therefore, pre-transplant BKV infection screening in kidney transplant patients should be performed for improving planning of personalized immunosuppressant schemes and specific post-transplant surveillance.

Transplantation of human fetal biliary tree stem/progenitor cells into two patients with advanced liver cirrhosis.

BACKGROUND: Efforts to identify cell sources and approaches for cell therapy of liver diseases are ongoing, taking into consideration the limits recognized for adult liver tissue and for other forms of stem cells. In the present study, we described the first procedure of via hepatic artery transplantation of human fetal biliary tree stem cells in patients with advanced cirrhosis. METHODS: The cells were immune-sorted from human fetal biliary tree by protocols in accordance with current good manufacturing practice (cGMP) and extensively characterized. Two patients with advanced liver cirrhosis (Child-Pugh C) have been submitted to the procedure and observed through a 12 months follow-up. RESULTS: The resulting procedure was found absolutely safe. Immuno-suppressants were not required, and the patients did not display any adverse effects correlated with cell transplantation or suggestive of immunological complications. From a clinical point of view, both patients showed biochemical and clinical improvement during the 6 month follow-up and the second patient maintained a stable improvement for 12 months. CONCLUSION: This report represents proof of the concept that the human fetal biliary tree stem cells are a suitable and large source for cell therapy of liver cirrhosis. The isolation procedure can be carried out under cGMP conditions and, finally, the infusion procedure is easy and safe for the patients. This represents the basis for forthcoming controlled clinical trials.

Bilateral ex vivo repair and kidney autotransplantation for complex renal artery aneurysms: a case report and literature review.

We report the surgical management of a bilateral renal artery aneurysm diagnosed in a 41-year-old patient with a history of recurrent abdominal pain. The preoperative contrast-enhanced computed tomography showed a complex saccular aneurysm on both renal arteries within the renal hilum. The characteristics of aneurysms precluded endovascular procedures, and a double-step bilateral ex vivo reconstruction with kidney autotransplantation was planned. The intra- and postoperative period was uneventful. Imaging and laboratory examinations show preservation of renal function, and patient is symptom-free at 10-month follow up.

The role of transplant-related stressors and social support in the development of anxiety among renal transplant recipients: the direct and buffering effects.

Several studies have shown a relevant presence of anxiety feelings among renal transplant patients. This study examines the impact of transplant-related stress and social support on anxiety. Two hypotheses were examined: H1: High transplant-related stressors and low social support are related to high anxiety (additive hypothesis); H2: Social support moderates the detrimental impact of transplant-related stressors on anxiety (buffer hypothesis). One hundred and four kidney transplant recipients (54% male), with a mean age of 50.8 (SD = 12.6), volunteered to participate in a cross-sectional study that included a face-to-face interview and several self-administered scales. Hierarchical regression analyses indicated that higher transplant-related stressors are associated with higher levels of anxiety (F change (2, 92) = 17.4, p < .001, ∆R(2) = 24%), but, contrary to our prediction, social support was not directly related with anxiety. However, social support has a moderating effect on the relationship between high transplant-related stressors and anxiety (F change (1, 91) = 5.2, p < .05, ∆R(2) = 3%). The results are consistent with the hypothesis that social support has a buffering role on the patients' distress following renal transplantation and suggest that their psychological well-being could benefit from enhancing the perception of social support in post-operative care.

Graft macrosteatosis and time of T-tube removal as risk factors for biliary strictures after liver transplantation.

Biliary strictures (BS) remain a significant problem following liver transplantation (LT), representing an important cause of morbidity. The purpose of this follow-up study was to evaluate the incidence and risk factors associated with BS after LT. From 2001 to 2009, 244 consecutive patients underwent LT at our center. Multiple donor and recipient variables were collected for each patient. Exclusion criteria were hepaticojejunostomy, living-donor LT, and follow-up less than three months. We reviewed 177 patients, all of whom underwent an end-to-end choledochocholedochostomy and T-tube placement. BS occurred in 23% of patients. Multivariate analysis revealed that graft macrovesicular steatosis >25% (p = 0.05, OR 3.38) and time of T-tube removal less than six months (p = 0.02, OR 2.53) were independent risk factors for BS. Biliary strictures did not affect patient and graft survival. Donor macrovesicular steatosis represents a risk factor for BS, contributing to liver damage through a reduction in hepatic blood flow. Time of T-tube removal seems to play a role in the development of BS, although it is unclear whether it represents the cause or the consequence of the development of BS.

Multipotent stem/progenitor cells in human biliary tree give rise to hepatocytes, cholangiocytes, and pancreatic islets.

UNLABELLED: Multipotent stem/progenitors are present in peribiliary glands of extrahepatic biliary trees from humans of all ages and in high numbers in hepato-pancreatic common duct, cystic duct, and hilum. They express endodermal transcription factors (e.g., Sox9, SOX17, FOXA2, PDX1, HES1, NGN3, PROX1) intranuclearly, stem/progenitor surface markers (EpCAM, NCAM, CD133, CXCR4), and sometimes weakly adult liver, bile duct, and pancreatic genes (albumin, cystic fibrosis transmembrane conductance regulator [CFTR], and insulin). They clonogenically expand on plastic and in serum-free medium, tailored for endodermal progenitors, remaining phenotypically stable as undifferentiated cells for months with a cell division initially every ≈36 hours and slowing to one every 2-3 days. Transfer into distinct culture conditions, each comprised of a specific mix of hormones and matrix components, yields either cords of hepatocytes (express albumin, CYP3A4, and transferrin), branching ducts of cholangiocytes (expressing anion exchanger-2-AE2 and CFTR), or regulatable C-peptide secreting neoislet-like clusters (expressing glucagon, insulin) and accompanied by changes in gene expression correlating with the adult fate. Transplantation into quiescent livers of immunocompromised mice results in functional human hepatocytes and cholangiocytes, whereas if into fat pads of streptozocin-induced diabetic mice, results in functional islets secreting glucose-regulatable human C-peptide. CONCLUSION: The phenotypes and availability from all age donors suggest that these stem/progenitors have considerable potential for regenerative therapies of liver, bile duct, and pancreatic diseases including diabetes.

Biliary tree stem/progenitor cells in glands of extrahepatic and intraheptic bile ducts: an anatomical in situ study yielding evidence of maturational lineages.

Stem/progenitors have been identified intrahepatically in the canals of Hering and extrahepatically in glands of the biliary tree. Glands of the biliary tree (peribiliary glands) are tubulo-alveolar glands with mucinous and serous acini, located deep within intrahepatic and extrahepatic bile ducts. We have shown that biliary tree stem/progenitors (BTSCs) are multipotent, giving rise in vitro and in vivo to hepatocytes, cholangiocytes or pancreatic islets. Cells with the phenotype of BTSCs are located at the bottom of the peribiliary glands near the fibromuscular layer. They are phenotypically heterogeneous, expressing transcription factors as well as surface and cytoplasmic markers for stem/progenitors of liver (e.g. SOX9/17), pancreas (e.g. PDX1) and endoderm (e.g. SOX17, EpCAM, NCAM, CXCR4, Lgr5, OCT4) but not for mature markers (e.g. albumin, secretin receptor or insulin). Subpopulations co-expressing liver and pancreatic markers (e.g. PDX1(+)/SOX17(+)) are EpCAM(+/-), and are assumed to be the most primitive of the BTSC subpopulations. Their descendants undergo a maturational lineage process from the interior to the surface of ducts and vary in the mature cells generated: pancreatic cells in hepatopancreatic ducts, liver cells in large intrahepatic bile ducts, and bile duct cells along most of the biliary tree. We hypothesize that there is ongoing organogenesis throughout life, with BTSCs giving rise to hepatic stem cells in the canals of Hering and to committed progenitors within the pancreas. The BTSCs are likely to be central to normal tissue turnover and injury repair and to be key elements in the pathophysiology of liver, pancreas and biliary tree diseases, including oncogenesis.

Prostate apoptosis response-4 is expressed in normal cholangiocytes, is down-regulated in human cholangiocarcinoma, and promotes apoptosis of neoplastic cholangiocytes when induced pharmacologically.

Prostate apoptosis response-4 (Par-4) is a tumor suppressor protein that sensitizes cells to apoptosis; therefore, Par-4 modulation has therapeutic potential. No data currently exist on Par-4 expression in cholangiocarcinoma (CCA). We evaluated the expression of Par-4 in normal and neoplastic cholangiocytes and the effects of its pharmacological or genetic modulation. The study was performed in human and rat liver, CCA patient biopsies, and two CCA cell lines. PAR-4 was expressed in normal rat and human cholangiocytes, but its expression levels decreased in both human CCA and CCA cell lines. In both intrahepatic and extrahepatic CCA, Par-4 expression (as shown by immunohistochemistry) was inversely correlated with markers of proliferation (eg, proliferating cellular nuclear antigen) and directly correlated with apoptotic markers (eg, Bax and Bax/BCL2 ratio). Par-4 expression was decreased during CCA cell proliferation but was enhanced after apoptosis induction. Pharmacological induction of Par-4 expression in CCA cell lines by diindolymethane or withaferin A promoted activation of apoptosis and inhibition of proliferation. In contrast, specific Par-4 silencing by small-interfering RNA determined activation of CCA cell line proliferation. Par-4 is expressed in rat and human cholangiocytes and is down-regulated in both human CCA and CCA cell lines. Par-4 protein levels decrease during cell proliferation but increase during apoptosis. Pharmacological or genetic induction of Par-4 determines apoptosis of CCA cells, suggesting Par-4 targeting as a CCA treatment strategy.

Cholest-4,6-Dien-3-One Promote Epithelial-To-Mesenchymal Transition (EMT) in Biliary Tree Stem/Progenitor Cell Cultures In Vitro.

Human biliary tree stem/progenitor cells (hBTSCs), reside in peribiliary glands, are mainly stimulated by primary sclerosing cholangitis (PSC) and cholangiocarcinoma. In these pathologies, hBTSCs displayed epithelial-to-mesenchymal transition (EMT), senescence characteristics, and impaired differentiation. Here, we investigated the effects of cholest-4,6-dien-3-one, an oxysterol involved in cholangiopathies, on hBTSCs biology. hBTSCs were isolated from donor organs, cultured in self-renewal control conditions, differentiated in mature cholangiocytes by specifically tailored medium, or exposed for 10 days to concentration of cholest-4,6-dien-3-one (0.14 mM). Viability, proliferation, senescence, EMT genes expression, telomerase activity, interleukin 6 (IL6) secretion, differentiation capacity, and HDAC6 gene expression were analyzed. Although the effect of cholest-4,6-dien-3-one was not detected on hBTSCs viability, we found a significant increase in cell proliferation, senescence, and IL6 secretion. Interestingly, cholest-4.6-dien-3-one impaired differentiation in mature cholangiocytes and, simultaneously, induced the EMT markers, significantly reduced the telomerase activity, and induced HDAC6 gene expression. Moreover, cholest-4,6-dien-3-one enhanced bone morphogenic protein 4 (Bmp-4) and sonic hedgehog (Shh) pathways in hBTSCs. The same pathways activated by human recombinant proteins induced the expression of EMT markers in hBTSCs. In conclusion, we demonstrated that chronic exposition of cholest-4,6-dien-3-one induced cell proliferation, EMT markers, and senescence in hBTSC, and also impaired the differentiation in mature cholangiocytes.

Simulated microgravity promotes the formation of tridimensional cultures and stimulates pluripotency and a glycolytic metabolism in human hepatic and biliary tree stem/progenitor cells.

Many pivotal biological cell processes are affected by gravity. The aim of our study was to evaluate biological and functional effects, differentiation potential and exo-metabolome profile of simulated microgravity (SMG) on human hepatic cell line (HepG2) and human biliary tree stem/progenitor cells (hBTSCs). Both hBTSCs and HepG2 were cultured in a weightless and protected environment SGM produced by the Rotary Cell Culture System (Synthecon) and control condition in normal gravity (NG). Self-replication and differentiation toward mature cells were determined by culturing hBTSCs in Kubota's Medium (KM) and in hormonally defined medium (HDM) tailored for hepatocyte differentiation. The effects on the expression and cell exo-metabolome profiles of SMG versus NG cultures were analyzed. SMG promotes tridimensional (3D) cultures of hBTSCs and HepG2. Significative increase of stemness gene expression (p < 0.05) has been observed in hBTSCs cultured in SMG when compared to NG condition. At the same time, the expression of hepatocyte lineage markers in hBTSCs differentiated by HDM was significantly lower (p < 0.05) in SMG compared to NG, demonstrating an impaired capability of hBTSCs to differentiate in vitro toward mature hepatocytes when cultured in SMG condition. Furthermore, in HepG2 cells the SMG caused a lower (p < 0.05 vs controls) transcription of CYP3A4, a marker of late-stage (i.e. Zone 3) hepatocytes. Exo-metabolome NMR-analysis showed that both cell cultures consumed a higher amount of glucose and lower glutamate in SMG respect to NG (p < 0.05). Moreover, hBTSCs media cultures resulted richer of released fermentation (lactate, acetate) and ketogenesis products (B-hydroxybutyrate) in SGM (p < 0.05) than NG. While, HepG2 cells showed higher consumption of amino acids and release of ketoacids (3-Methyl-2-oxovalerate, 2-oxo-4-methyl-valerate) and formiate with respect to normogravity condition (p < 0.05). Based on our results, SMG could be helpful for developing hBTSCs-derived liver devices. In conclusion, SMG favored the formation of hBTSCs and HepG2 3D cultures and the maintenance of stemness contrasting cell differentiation; these effects being associated with stimulation of glycolytic metabolism. Interestingly, the impact of SMG on stem cell biology should be taken into consideration for workers involved in space medicine programs.

Appraisal of transplant-related stressors, coping strategies, and psychosocial adjustment following kidney transplantation.

This study examined the relations between appraisal of transplant-related stressors, coping, and adjustment dimensions following kidney transplantation (KT). Two models were tested: (1) the main effects model proposing that stress appraisal and coping strategies are directly associated with adjustment dimensions; and (2) the moderating model of stress proposing that each coping strategy interacts with stress appraisal. Importantly, there is a lack of research examining the two models simultaneously among recipients of solid organ transplantation. A total of 174 KT recipients completed the questionnaires. Predictors of post-transplant adjustment included appraisal of transplant-related stressors and coping strategies (task-, emotion-, and avoidance-focused). Adjustment dimensions were psychological distress, worries about the transplant, feelings of guilt, fear of disclosure of transplant, adherence, and responsibility for the functioning of the new organ. The main and moderating effects were tested with regression analyses. Appraisal of transplant-related stressors and emotion-oriented coping were related to all adjustment dimensions, except of adherence and responsibility. Task-oriented coping was positively related to responsibility. Avoidance-oriented coping was negatively correlated with adherence. Only 1 out of 18 hypothesized interactive terms was significant, yielding a synergistic interaction between appraisal of transplant-related stressors and emotion-oriented coping on the sense of guilt. The findings have the potential to inform interventions promoting psychosocial adjustment among KT recipients.

Hyaluronan coating improves liver engraftment of transplanted human biliary tree stem/progenitor cells.

BACKGROUND: Cell therapy of liver diseases with human biliary tree stem cells (hBTSCs) is biased by low engraftment efficiency. Coating the hBTSCs with hyaluronans (HAs), the primary constituents of all stem cell niches, could facilitate cell survival, proliferation, and, specifically, liver engraftment given that HAs are cleared selectively by the liver. METHODS: We developed a fast and easy method to coat hBTSCs with HA and assessed the effects of HA-coating on cell properties in vitro and in vivo. RESULTS: The HA coating markedly improved the viability, colony formation, and population doubling of hBTSCs in primary cultures, and resulted in a higher expression of integrins that mediate cell attachment to matrix components. When HA-coated hBTSCs were transplanted via the spleen into the liver of immunocompromised mice, the engraftment efficiency increased to 11% with respect to 3% of uncoated cells. Notably, HA-coated hBTSC transplantation in mice resulted in a 10-fold increase of human albumin gene expression in the liver and in a 2-fold increase of human albumin serum levels with respect to uncoated cells. Studies in distant organs showed minimal ectopic cell distribution without differences between HA-coated and uncoated hBTSCs and, specifically, cell seeding in the kidney was excluded. CONCLUSIONS: A ready and economical procedure of HA cell coating greatly enhanced the liver engraftment of transplanted hBTSCs and improved their differentiation toward mature hepatocytes. HA coating could improve outcomes of stem cell therapies of liver diseases and could be immediately translated into the clinic given that GMP-grade HAs are already available for clinical use.

Cryopreservation protocol for human biliary tree stem/progenitors, hepatic and pancreatic precursors.

Human biliary tree stem/progenitor cells (hBTSCs) are being used for cell therapies of patients with liver cirrhosis. A cryopreservation method was established to optimize sourcing of hBTSCs for these clinical programs and that comprises serum-free Kubota's Medium (KM) supplemented with 10% dimethyl sulfoxide (DMSO), 15% human serum albumin (HSA) and 0.1% hyaluronans. Cryopreserved versus freshly isolated hBTSCs were similar in vitro with respect to self-replication, stemness traits, and multipotency. They were able to differentiate to functional hepatocytes,cholangiocytes or pancreatic islets, yielding similar levels of secretion of albumin or of glucose-inducible levels of insulin. Cryopreserved versus freshly isolated hBTSCs were equally able to engraft into immunocompromised mice yielding cells with human-specific gene expression and human albumin levels in murine serum that were higher for cryopreserved than for freshly isolated hBTSCs. The successful cryopreservation of hBTSCs facilitates establishment of hBTSCs cell banking offering logistical advantages for clinical programs for treatment of liver diseases.

Chylous Leakage After a Laparoscopic Live-Donor Nephrectomy: Case Report and Literature Review.

Laparoscopic donor nephrectomy is an established operation for organ procurement in living-donor transplant. Minimal access approach for organ procurement from living donors ensures early convalescence and improved patient participation. Chylous leakage is a rare complication of laparoscopic living-donor nephrectomy. Chylous leakage is mostly determined by iatrogenic injury of cisterna chyli and its main tributaries. It may lead to malnutrition and immunologic deficits because of protein and lymphocyte depletion. An 18-year-old woman underwent left-hand-assisted laparoscopic donor nephrectomy for living donor transplant. She developed chylosus leakage in third postoperative day. A conservative manage-ment with total parenteral nutrition total paren-teral nutrition and subcutaneous somatostatin was immediately initiated. The patient had an abatement of drainage daily output in 4 days of therapy. Chylous leakage is a potentially insidious and perhaps misdiagnosed complication of laparoscopic donor nephrectomy. Conservative therapy is effective in most donors and should be initially attempted. Surgical ligatures or fibrin sealants may be indicated in case of refractory chylous leakage before the arising of malnutrition and/or relevant immunodeficiency.

Renal Papillary Carcinoma Developed in a Kidney Transplant Recipient With Late IgA-Nephropathy.

With improvements in immunosuppressive therapy, patient and graft survival in renal transplant recipients have been prolonged. Increasing donor age and patient survival rates have been related to an increase in the number of de novo tumors. Posttransplant malignancy in these patients is an important cause of graft loss and death in these patients. Among cancers occurring after a kidney transplant, renal cell carcinoma is the fifth most common malignancy after lymphoproliferative disorders, and skin, gastrointestinal, and lung cancers. When nonmelanoma skin cancers and in situ carcinoma of the cervix are excluded from malignancies, renal cell carcinoma accounts for 2% of all cancers in the general population, which increases to 5% in solid-organ recipients. The majority of renal cell carcinomas found in transplant recipients develop in the recipient 's native kidneys, but only 9% of tumors develop in the allograft itself. Tumors transmitted by donors represent only 0.02% to 0.2% of cases. Most de novo allograft renal cell carcinomas are single tumors. The mechanisms of development of renal cell carcinoma in renal grafts are not completely understood.