Overexpression of miR-122 promotes the hepatic differentiation and maturation of mouse ESCs through a miR-122/FoxA1/HNF4a-positive feedback loop.

BACKGROUND & AIMS: microRNA-122 is the only identified liver-specific miRNA and plays a crucial role in liver development, maintenance of hepatic homeostasis as well as tumourigenesis. In our previous differentiation of ESCs into hepatocytes, microRNA-122 (miR-122) was expressed at a relatively low level. Here, we aim to elucidate the effect and underlying mechanisms of miR-122 during differentiation of ESCs into hepatocytes. METHODS: Mouse ESCs were initially induced towards HPCs by activin A, FGF-4 and sodium butyrate and were subsequently transfected with a recombinant adenovirus expressing vector pAV.Ex1d-CMV>miR-122/IRES/eGFP 9 days after induction. Cells were analysed by real-time PCR, immunofluorescence, flow cytometry, microscopy and functional assays. Furthermore, microarray analysis was performed. RESULTS: We demonstrated that overexpression of miR-122 could effectively promote hepatic differentiation and maturation, as assessed by morphological and functional tests. The microarray analysis revealed that 323 genes were down-regulated, whereas 59 were up-regulated. Particularly, two liver-specific transcription factors, FoxA1 and HNF4a, were significantly up-regulated. Moreover, the expression of E-cadherin was dramatically increased and the proliferation of HPCs was suppressed, whereas knockdown of FoxA1 reduced E-cadherin expression and increased the proliferation of HPCs. In addition, the expression levels of FoxA1, HNF4a and E-cadherin in time-course transfection experiments with miR-122 were not significantly increased except in cells in which transfection with miR-122 occurred 9 days after induction. CONCLUSION: Overexpression of miR-122 at an appropriate stage could promote hepatic differentiation and maturation by regulating the balance between proliferation and differentiation, as well as the balance between EMT and MET, partially through a miR-122/FoxA1/HNF4a-positive feedback loop.

[The clinic research of the modified laparoscopic splenectomy for massive splenomegaly in the treatment of children with hematologic diseases].

OBJECTIVE: To summarize the experience and characteristics of the modified laparoscopic splenectomy for massive splenomegaly in the treatment of children with hematologic disease. METHODS: The clinical data of 30 cases of laparoscopic splenectomy for massive splenomegaly of children with hematologic disease from March 2007 to December 2011 was analyzed retrospectively. There were 18 male and 12 female patients, aging from 2 to 14 years. Primary disease included mediterranean anemia (17 cases), hereditary spherocytosis (4 cases) and idiopathic thrombocytopenic purpura (ITP, 9 cases). Dissection started with cutting off the gastrosplenic ligaments and lesser sac to fully reveal the splenic hilum, the splenic artery was clamped twice with 10 mm tiatanum clamp. When most of blood stored in the spleen back to heart through the veins and the splenic volume had already decreased, the splenic vein was ligated with 10 mm titanium clip and cut with ligsure and splenic pedicle separated. The Surgery and complication were recorded. For 1 week after surgery, the hemoglobin and platelet counts were reviewed. RESULTS: Twenty-six cases were performed successfully, and 4 cases were converted to open procedure. Of the 4 cases, 2 cases was obesity because of idiopathic thrombocytopenic purpura, 1 case was ß thalassaemia combined severe liver enlargement, and 1 case was after partial splenic embolization. In cases of laparoscopic splenectomy, operation time was 110 to 130 minutes, with an average of 120 minutes, and blood loss during operation was 35 to 180 ml, with an average of 45 ml. Compared with pre-operation, the hemoglobin of mediterranean anemia and hereditary spherocytosis patients were (92 ± 8) g/L, and blood platelet count of ITP patients was (127 ± 20)×10(9)/L, and they increased obviously at 1 week after operation (t = 4.175 and 8.253, both P = 0.000). CONCLUSION: The modified surgical method make the laparoscopic splenectomy for massive splenomegaly in many children with hematologic diseases possible, which was thought to be impossible in the past.

A modified laparoscopic splenectomy for massive splenomegaly in children with hematological disorder: a single institute retrospective clinical research.

PURPOSE: With the optimal acceptance of its clinical advantages, laparoscopic splenectomy (LS) emerged as a gold standard procedure as compared with open splenectomy (OS). However, it is still controversial and even counted as contraindication for massive splenomegaly. Here, we aim to summarize the experiences, characteristics and trends of modified LS for massive splenomegaly in children with hematological disorders. METHODS: Retrospective series of 57 pediatric patients with massive splenomegaly who underwent splenectomy from March 2007 to December 2011 were designated for this clinical analysis. The main outcome measures were dealt by statistics. For 30 cases of LS, we strictly adhered to the principle of using only three trocars to operate and initial ligation of the splenic artery, followed by retrieving the piecemeal of spleen through an accessory incision of 2-3 cm at 12 mm trocar port site. RESULTS: Of the 57 pediatric patients, 27 underwent OS and 30 underwent LS, respectively. Despite the operative time being shorter for OS than for LS (P < 0.001), the blood loss was lower in LS than in OS (P < 0.001); the time required for oral intake as well as duration of hospital stay was lower in LS than in OS (P < 0.001). Post-operatively, 7 (25.9 %) complications occurred in OS and 3 (10 %) in LS. The conversion rate of LS to OS was 13.33 % in four cases till 2009. CONCLUSIONS: Despite the conflicting reports regarding the safety of LS for massive splenomegaly, we demonstrated that our modified laparoscopic splenectomy in the treatment of children with massive splenomegaly in hematological diseases seemed to achieve the fundamental goal of less invasion; it was safe and feasible.

Selection of hepatocyte-like cells from mouse differentiated embryonic stem cells and application in therapeutic liver repopulation.

UNLABELLED: BACKGROUD/AIM: Because of the oncogenic risk, it is important to gain the homogeneous and purified cells from differentiated ESCs before transplantation. Here, we aim to select hepatocyte-like cells from differentiated ESCs, and investigate their growth, differentiation and neoplastic formation after intrahepatic transplantation. METHODS: Mouse ESCs were primarily induced by Dexamethesone, FGF-4 and HGF sequentially, then placed to a conditioning selection media consisting of 5% cholestatic sera and cultivated for 2 wks. After labeled by CFDA-SE, the selected cells were transplanted into mouse liver in therapeutic liver repopulation models. RESULTS: In the early stage of screening cultivation, most cells were suffered from apoptosis or even death. 1w later, some hepatocyte-like colony-forming units were observed, then the selected cells could grow and tend to be more mature, as assessed by morphological and functional tests. After intrahepatic transplantation, the labeled cells could proliferate and expressed albumin. Moreover, teratoma didn't form over 3 months. CONCLUSION: Our conditioning selection media could not only effectively select hepatocyte-like cells from differentiated ESCs, but further promote their growth and differentiation as well. After intrahepatic transplantation in therapeutic liver repopulation models, the selected cells could grow, differentiate and keep partial hepatic function. In particular, the transplantation was safe.