Hepatic differentiation capability of rat bone marrow-derived mesenchymal stem cells and hematopoietic stem cells

AIM: To investigate the different effects of mesenchymal stem cells (MSCs) and hematopoietic stem cells (HSCs) on hepatic differentiation.METHODS: MSCs from rat bone marrow were isolated and cultured by standard methods. HSCs from rat bone marrow were isolated and purified by magnetic activated cell sorting. Both cell subsets were induced. Morphology, RT-PCR and immunocytochemistry were used to identify the hepatic differentiation grade.RESULTS: MSCs exhibited round in shape after differentiation, instead of fibroblast-like morphology before differentiation. Albumin mRNA and protein were expressed positively in MSCs, without detection of alpha-fetoprotein (AFP). HSCs were polygonal in shape after differentiation. The expression of albumin signal decreased and AFP signal increased. The expression of CK18 was continuous in MSCs and HSCs both before and after induction.CONCLUSION: Both MSCs and HSCs have hepatic differentiation capabilities. However, their capabilities are not the same. MSCs can differentiate into mature hepatocyte-like cells, never expressing early hepatic specific genes, while Thy-1.1^+cells are incllned to differentiate into hepatic stem cell-like cells, with an increasing AFP expression and a decreasing albumin signal. CK18 mRNA is positive in Thy-1.1^+ cells and MSCs, negative in Thy-1.1^+ cells. It seems that CK18 has some relationship with Thy-1.1 antigen, and CK18 may be a predictive marker of hepatic differentiation capability.

Dendritic cells from chronic hepatitis B patients can induce HBV antigen-specific T cell responses

AIM: To determine whether dendritic cells (DCs) from chronic hepatitis B patients could induce HBV antigenspecific T cell responses or not. METHODS: DCs were generated from peripheral blood mononuclear cells of patients with chronic hepatitis B (CHB) infection and healthy donors. We compared the phenotypes of these DCs and their ability to secrete cytokines and to participate in mixed lymphocyte reactions. In addition, autologous lymphocytes were cultured with DCs loaded with HBV core region peptide HBcAg8-27, an epitope recognized by cytotoxic T lymphocytes(CTL), and bearing human leucocyte antigen (HLA)-A2 for 10 d. Cytokine secretion and lytic activity against peptide-pulsed target cells were assessed. RESULTS: DCs with typical morphology were generated successfully by culturing peripheral blood mononuclear cells (PBMCs) from CriB patients with AIM-V containing GM-CSF and IL-4. Compared with DCs from normal donors, the level of CD80 expressed in DCs from CHB patients was lower, and DCs from patients had lower capacity of stimulate T cell proliferation. When PBMCs isolated from patients with chronic or acute hepatitis B infection and from normal donors were cocultured with HBcAg18-27 peptide, the antigen-specific memory response of PBMCs from acute hepatitis B patients was stronger than that of PBMCs from chronic hepatitis B patients or normal donors. PBMCs cocultured with DCs treated with HBcAg18-27 CTL epitope peptide induced an antigen-specific T cell reaction, in which the level of secreted cytokines and lyric activity were higher than those produced by memory T cells. CONCLUSION: DCs from patients with CHB can induce HBV antigen-specific T cell reactions, including secretion of cytokines essential for HBV clearance and for killing cells infected with HBV.

Effect of operation-synchronizing transfusion of apoptotic spleen cells from donor rats on acute rejection of recipient rats after liver transplantation

AIM: To study effect of operation-synchronizing transfusion of apoptotic spleen cells from donor rats on acute rejection of recipient rats after liver transplantation.METHODS: Two of Wistar rats were chosen randomly for normal liver pathology control and ten of SD rats chosen randomly for liver function control as blank group (no operation). The rest of Wistar and SD rats were divided into four groups: control group (only liver transplantation),Dex group (donors receiving intraperitoneal injection of dexamethasone), SpC group (recipients receiving infusion of spleen cells of donors), Dex-SpC group (recipients receiving infusion of apoptotic spleen cells of donors),with each group except blank group, containing 10 SD rats and 10 Wistar rats, respectively. Wistar rats received liver transplantation from SD rats, in the meantime they received infusion of spleen cells of donors, which were induced by an intraperitoneal injection of dexamethasone The serum alanine transaminase (ALT), total bilirubin (T bili), liver pathological changes and survival time were analysed. Statistical analysis was carried out using SPSS 10.0 for Windows. Differences of the parametric data of ALT in means were examined by one-way ANOVA.Differences of ALT between two groups were examined by LSD. Differences of the nonparametric data of T bili in means and scores of pathology classification for acute rejection were examined by Kruskal-Willis H test. The correlations between ALT and T bili were analysed by Bivariate. Kaplan-Meier curves were used to demonstrate survival distribution. The log-rank test was used to compare the survival data.RESULTS: There were significant differences in ALT of the five groups (F= 23.164 P= 0.000), and ALT in DexSpC group was significantly higher than that in blank control, control, Dex, and SpC groups (P = 0.000), and ALT in SpC group was significantly higher than that in blank control (P = 0.000), control (P = 0.004), and Dex groups (P = 0.02). Results of nonparametric analysis of T bili showed that there were differences in T bili of the five groups (χ2 = 33.265 P= 0.000). T bili in Dex-SpC group was significantly higher than that in blank control, control,Dex, and SpC groups. T bili in SpC group was higher than that in blank control, control, and Dex groups. There were significant differences in scores of pathology classification for acute rejection in each of the groups (χ2 = 25.933,P = 0.000). The pathologically more serious acute rejection was found in Dex-SPC group than in other groups. No sign of acute rejection was observed in the blank control group.Slight acute rejection was observed in the control group.Slight-moderate acute rejection was observed in the Dex group. Moderate-acute rejection was observed in the SpC group. Severe-acute rejection was observed in the DexSpC group. The survival time in Dex-SpC group was shorter than in other groups (statistic = 11.13, P = 0.011). ALT and T bili were positively correlated (r= 0.747, P= 0.000,two-tailed).CONCLUSION: In order to reduce quantity of blood loss from rats after liver transplantation, only one of ALT or T bili is needed for liver function measurement of rats.Simultaneous injection of apoptotic spleen cells from donors induced by dexamethasone to liver transplantation rats aggravates acute rejection. One important mechanism of aggravation of acute rejection may be that apoptotic cells are not removed in time and that dead cells including apoptotic cells release inflammatory factors.

Chromic-P32 phosphate treatment of implanted pancreatic carcinoma: Mechanism involved

AIM: To study the effects of chromic-P32 phosphate (32p colloids) interstitial administration in Pc-3 implanted pancreatic carcinoma, and investigate its anticancer mechanism.METHODS: Ninety-eight tumor bearing nude mice werekilled at different time points after the injection of 32Pcolloids to the tumor core with observed radioactivity. The light microscopy, transmission electron microscopy (TEM) and immuno-histochemistry and flow cytometry were used to study the rates of tumor cell necrosis, proliferating cell nuclear antigen index, the micro vessel density (MVD). The changes of the biological response to the lymphatic transported 32p colloids in the inguinal lymph node (ILN) were dynamically observed, and the percentage of tumor cell apoptosis, and Apo2.7, caspase-3, Bcl-2, Baxrelated gene expression were observed too.RESULTS: The half-life of effective medication is 13 dafter injection of 32P colloids to the tumor stroma, in 1-6groups, the tumor cell necrosis rates were 20%, 45%,65%, 70%, 95% and 4%, respectively (F= 4.14-105.36, P＜0.01). MVD were 38.5±4.0, 28.0±2.9, 17.0±2.9, 8.8±1.5,5.7±2.3 and 65.0±5.2 (t= 11.9-26.1, P＜0.01), respectively.Under TEM fairly differentiated Pc-3 cells were found. Thirty days after medication, tumors were shrunk and dried with scabs detached, and those in control group increased in size prominently with plenty of hypodermic blood vessels. In all animals the ILN were enlarged but in medicated animals they appeared later and smaller than those in control group. The extent of irradiative injury in ILN was positively correlated to the dosage of medication. Typical tumor cell apoptosis could be found under TEM inanimals with intra-tumoral injection of low dosed 32P colloids. The peak of apoptosis occurred in 2.96 MBq group and 24 h after irradiation. In the course of irradiationinduced apoptosis, the value of Bcl-2/Bax was down regulated; Apo2.7 and caspase-3 protein expression were prominently increased dose dependently. CONCLUSION: 32p colloids intra-tumor injection having prominent anticancer effectiveness may reveal the ability of promoting cell differentiation. The low dose 32P colloids may induce human pancreatic carcinoma Pc-3 implanted tumor cell apoptosis; Apo2.7, caspase-3, Bcl-2 and Bax protein participated in regulating the process of irradiation induced cell apoptosis.

Effect of insulin on hyperkalemia during anhepatic stage of liver transplantation

AIM: To investigate the effectiveness of insulin on decreasing serum potassium concentration during anhepatic stage of orthotopic liver transplantation.METHODS: Sixteen patients with serum potassium concentrations greater than 4.0 mmol/L at the onset of anhepatic stage were randomized into two groups. The patients in control group (n = 8) received no treatment,while those in treatment group (n = 8) received an intravenous bolus injection of regular insulin (20 U) 10 min into the anhepatic stage, followed by a glucose infusion(500 mL 50 g/L dextrose) over 15 min.RESULTS: In control group, potassium concentration underwent no changes whereas in treatment group, it decreased from 4.8±0.48 mmol/L to 4.19±0.55 mmol/L(mean±SD) within 15 min and to 3.62±0.45 mmol/L 60 min after the therapy. The potassium concentration was lower in treatment group than in control group within 30 min of treatment (3.94+0.57 vs 4.47±0.42 mmol/L,respectively; P<0.05), and increased similarly 30 s after graft reperfusion in both groups of patients, but remained lower in treatment group (5.81±1.78 vs7.44±1.75 mmol/L,respectively; P<0.05). The potassium concentration returned to pre-reperfusion levels within 5 min after graft reperfusion.CONCLUSION: In patients undergoing orthotopic liver transplantation, the administration of insulin rapidly decreases serum potassium concentration even in the absence of the liver, suggesting an important contribution by extrahepatic tissues in insulin-stimulated uptake of potassium.

Altered Wnt Signaling Pathway in Cognitive Impairment Caused by Chronic Intermittent Hypoxia： Focus on Glycogen Synthase Kinase-3β and β-catenin

Background： Cognitive impairment is a severe complication caused by obstructive sleep apnea （OSA）. The mechanisms of causation are still unclear. The Wntβ-catenin signaling pathway is involved in cognition, and abnormalities in it are implicated in neurological disorders. Here, we explored the Wntβ-catenin signaling pathway abnormalities caused by chronic intermittent hypoxia （CIH）, the most characteristic pathophysiological component of OSA. Methods： We divided 32 4-week-old male C57/BL mice into four groups of eight each： a CIH ＋ normal saline （NS） group, CIH ＋ LiCI group, sham CIH ＋ NS group, and a sham CIH ＋ LiCI group. The spatial learning performance of each group was assessed by using the Morris water maze （MWM）. Protein expressions of glycogen synthase kinase-β （GSK-β） and β-catenin in the hippocampus were examined using the Western blotting test. EdU labeling and terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling staining methods were used, respectively, to determine the proliferation and apoptosis of neurons in the hippocampal dentate gyrus region. Results： Mice exposed to CIH showed impaired spatial learning performance in the MWM, including increased mean escape latencies to reach the target platform, decreased mean times passing through the target platform and mean duration in the target quadrant. The GSK-313 activity increased, and expression of β-catenin decreased significantly in the hippocampus of the CIH-exposed mice. Besides, CIH significantly increased hippocampal neuronal apoptosis, with an elevated apoptosis index. Meanwhile, LiCI decreased the activity of GSK-β and increased the expression of β-catenin and partially reversed the spatial memory deficits in MWM and the apoptosis caused by CIH. Conclusions： Wntβ-catenin signaling pathway abnormalities possibly play an important role in the development of cognitive deficits among mice exposed to CIH and that LiCI might attenuate CIH-induced cognitive impairment via Wntβ-catenin signaling pathway.

Osteogenic effects of antihypertensive drug benidipine on mouse MC3T3-E1 cells in vitro

Hypertension is a prevalent systemic disease in the elderly,who can suffer from several pathological skeletal conditions simultaneously,including osteoporosis.Benidipine(BD),which is widely used to treat hypertension,has been proved to have a beneficial effect on bone metabolism.In order to confirm the osteogenic effects of BD,we investigated its osteogenic function using mouse MC3T3-E1 preosteoblast cells in vitro.The proliferative ability of MC3T3-E1 cells was significantly associated with the concentration of BD,as measured by methylthiazolyldiphenyl-tetrazolium bromide(MTT)assay and cell cycle assay.With BD treatment,the osteogenic differentiation and maturation of MC3T3-E1 cells were increased,as established by the alkaline phosphatase(ALP)activity test,matrix mineralized nodules formation,osteogenic genetic test,and protein expression analyses.Moreover,our data showed that the BMP2/Smad pathway could be the partial mechanism for the promotion of osteogenesis by BD,while BD might suppress the possible function of osteoclasts through the OPG/RANKL/RANK(receptor activator of nuclear factor-κB(NF-κB))pathway.The hypothesis that BD bears a considerable potential in further research on its dual therapeutic effect on hypertensive patients with poor skeletal conditions was proved within the limitations of the present study.