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

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

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

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.MethodsThe 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 cirrhosis (Child-Pugh C) have been submitted to the procedure and observed through a 12 months follow-up.ResultsThe 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 (Table1), and the second patient maintained a stable improvement for 12 months.ConclusionThis 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

Microperimetric evaluation and predictive factors of visual recovery after successful inverted internal limiting membrane-flap technique for macular hole in high myopic eyes

IntroductionInverted Internal Limiting Membrane (ILM)-flap technique demonstrated its effectiveness, in terms of anatomical closure rate and visual acuity recovery for high myopic macular holes. We evaluated macular function after a successful inverted ILM-flap for macular holes in high myopic eyes (hMMH) using microperimetry to predict visual prognosis.MethodsA retrospective study on 23 eyes of 23 patients after surgical closure of hMMH, was performed. All patients underwent inverted ILM-flap and gas tamponade. Cataract surgery was performed in phakic eyes. Study outcomes including best-corrected visual acuity (BCVA), retinal sensitivity (RS) at central 12°, central retinal sensitivity (CRS) at central 4° and mean deviation (MD), and fixation behavior as bivariate contour ellipse area (BCEA, degrees2) measured by microperimetry, were evaluated over 6 months. A mixed-effects model was used to evaluate and compare the repeated measurements of outcomes between phakic and pseudophakic eyes. A regression model was performed to assess the relationship between BCVA at 6 months and independent variables.ResultsOverall mean BCVA improved from 0.98 ± 0.21 logMAR at baseline to 0.47 ± 0.31 logMAR at the last follow-up (p < 0.001). Over 6 months, overall sensitivity measurements improved (RS, p = 0.001; CRS, p < 0.0001; MD, p = 0.03), and the BCEA decreased in dimension, although not significantly (p ≥ 0.05). The mixed model revealed a significantly better effect of inverted ILM-flap combined with cataract surgery on BCVA and CRS in phakic eyes than inverted ILM-flap alone in pseudophakic ones. The regression model revealed a relationship of 6-month BCVA with pre-operative BCVA (β = 0.60, p = 0.02) and RS (β = −0.03, p = 0.01).ConclusionThe inverted ILM-flap technique significantly improved visual acuity and retinal sensitivity after the hMMH closure, particularly when combined with cataract extraction. Pre-operative visual acuity and retinal sensitivity at central 12° may predict post-surgical visual acuity

Analisi dell'espressione e della funzione di DjMap durante la rigenerazione tissutale in planaria

Le cellule staminali sono cellule indifferenziate capaci di differenziarsi e di auto rinnovarsi. Queste capacità sono controllate tramite segnali esogeni ed endogeni, come fattori rilasciati da tessuti differenziati circostanti, la cosiddetta nicchia. Le planarie d’acqua dolce vengono ampiamente utilizzate come sistema modello per lo studio in vivo di cellule staminali adulte in quanto possiedono una abbondante popolazione di cellule staminali pluripotenti adulte, i neoblasti, grazie alla quale sono in grado di rigenerare in breve tempo qualsiasi parte del loro corpo. Sebbene si conoscano in planaria diversi fattori endogeni coinvolti nel controllo dei neoblasti, sono poco conosciuti i fattori esogeni. Scopo di questa tesi è, quindi, identificare in planaria fattori esogeni coinvolti nella biologia dei neoblasti al fine di contribuire alla comprensione del controllo delle cellule staminali. Durante il mio lavoro di tesi, ho analizzato l’espressione e la funzione del gene DjMap, un omologo del gene futsch di Drosophila che codifica per una proteina MAP coinvolta nell’organizzazione, la stabilizzazione e la funzione del citoscheletro durante lo sviluppo neuronale e la formazione assonale.Esperimenti di ibridazione in situ mostrano che il gene DjMap è preferenzialmente espresso a livello del sistema nervoso e il confronto dell’espressione tra animali irradiati letalmente e di controllo mostra che DjMap non è espresso nei neoblasti. Il silenziamento, mediante esperimenti di RNA interference, induce un ritardo rigenerativo con la formazione di un blastema di dimensioni ridotte. L’analisi in questi organismi dell’espressione di marcatori molecolari dei neoblasti come DjMcm2, Djsox, DjPiwi-1 mostra una riduzione dei neoblasti in animali silenziati per DjMap, e l’analisi dell’espressione di marcatori di cellule determinate verso diverse linee differenziative mostra una riduzione significativa delle progenie. Al fine di capire se DjMap svolga un ruolo nella rigenerazione del sistema nervoso, esperimenti di immunolocalizzazione con un marcatore del sistema nervoso (3C11) e del chiasma ottico (VC1) sono stati condotti in animali di controllo e silenziati. I dati ottenuti mostrano un ritardo nella formazione del sistema nervoso e difetti nel chiasma ottico che permangono anche dopo 16 giorni dall’induzione della rigenerazione. Difetti nel sistema nervoso sono stati evidenziati anche in animali intatti silenziati per l’espressione di DjMap. In questi animali, oltre ad una riduzione dei neoblasti, si verifica un’aberrante risposta quando gli organismi sono sottoposti a stimoli luminosi mediante test di fotofobicità, indicando difetti al livello del sistema nervoso. In conclusione, i dati ottenuti indicando che il gene DjMap è espresso al livello del sistema nervoso ed è implicato nella rigenerazione del sistema nervoso e nella biologia delle cellule staminali permettendo di ipotizzare che sia coinvolto indirettamente nel rilascio da parte del sistema nervoso di segnali necessari per il mantenimento e proliferazione delle cellule staminali di planaria

The Effect of Hyaluronic Acid and Chondroitin Sulphate-Based Medical Device Combined with Acid Suppression in the Treatment of Atypical Symptoms in Gastroesophageal Reflux Disease

Extraesophageal reflux symptoms are increasingly common in the Western population and their clinical management is still controversial. Although therapy with proton-pump inhibitors (PPIs) represents the gold standard, to date, many patients are refractory to this treatment. The aim of this study was to evaluate, in patients with a recent diagnosis of GERD experiencing extraesophageal symptoms, the efficacy and safety of a 6-week treatment with PPI acid suppression in combination with Gerdoff® (a hyaluronic acid and chondroitin sulphate-based medical device) compared to PPI monotherapy. The trial verified the reduction in symptom frequency and severity by evaluating the proportion of Responders and Non-Responder patients after 6 weeks of treatment, compared to baseline. The effects of Gerdoff® + PPI treatment on extraesophageal symptoms were also evaluated after a 12-week follow up only in Responder patients. The analysis of the change in total Reflux Symptoms Index (RSI) score from baseline to the other time points showed that the extent of the decrease from baseline was higher in the Gerdoff® + PPI group than in the PPI group at any time point. However, the comparison between groups did not show statistically significant differences at any time point. A statistically significant difference, in favor of the Gerdoff® + PPI group, was observed for individual RSI items. Even if the trial showed some limitations, this is the first published study on the efficacy of a medical device containing hyaluronic acid and chondroitin sulphate with antacid in the treatment of extraesophageal reflux symptoms

Cholangiocarcinoma: epidemiology and risk factors.

Cholangiocarcinoma (CCA) is a malignant tumour, arising from biliary epithelium at any portion of the biliary tree, characterized by a bad prognosis and poor response to current therapies. CCA is currently classified as intrahepatic (IHCCA) or extrahepatic (EH-CCA). The distinction between IH-CCA and EH-CCA has become increasingly important, as the epidemiological features (i.e., incidence and risk factors), the biologic and pathologic characteristics and the clinical course are largely different. New insights into hepatic and biliary tree stem cell niches organization, into cancer cells of origin and cancer stem cell biology are currently under evaluation as the biological bases of the observed heterogeneity of CCA and could explain the differences in epidemiology and risk factors between IH- and EH-CCA. The purpose of this manuscript is to revise recent literature dealing with the descriptive epidemiology, risk factors and clinical-pathological heterogeneity of CCA with a special effort to compare IH- versus EH-CCA

Intra-hepatic and extra-hepatic cholangiocarcinoma: New insight into epidemiology and risk factors

Cholangiocarcinoma (CCA) is a malignant tumour that arises from biliary epithelium at any portion of the biliary tree. CCA is currently classified as intra-hepatic or extra-hepatic CCA (EH-CCA). Recent evidences suggest that intra-hepatic CCA (IH-CCA) and EH-CCA are biologically different cancers, giving further support to a number of recent epidemiological studies showing large differences in terms of incidence, mortality and risk factors. The purpose of this manuscript is to review recent literature dealing with the descriptive epidemiology and risk factors of CCA with a special effort to compare IH- with EH-CCA