Biomedical subjects

Yu-Dong Qiu

Publications and source records attributed to Yu-Dong Qiu.

13 recordsLinked to original sources

PubMed2005

Differential gene expression during capillary morphogenesis in a microcarrier-based three-dimensional in vitro model of angiogenesis with focus on chemokines and chemokine receptors.

AIM: To globally compare the gene expression profiles during the capillary morphogenesis of human microvascular endothelial cells (HMVECs) in an in vitro angiogenesis system with affymetrix oligonucleotide array. METHODS: A microcarrier-based in vitro angiogenesis system was developed, in which ECs migrated into the matrix, proliferated, and formed capillary sprouts. The sprouts elongated, branched and formed networks. The total RNA samples from the HMVECs at the selected time points (0.5, 24, and 72 h) during the capillary morphogenesis were used for microarray analyses, and the data were processed with the softwares provided by the manufacturers. The expression patterns of some genes were validated and confirmed by semi-quantitative RT-PCR. The regulated genes were grouped based on their molecular functions and expression patterns, and among them the expression of chemokines and chemokine receptors was specially examined and their functional implications were analyzed. RESULTS: A total of 1 961 genes were up- or down-regulated two-folds or above, and among them, 468 genes were up- or down-regulated three-folds or above. The regulated genes could be grouped into categories based on their molecular functions, and were also clustered into six groups based on their patterns of expression. As for chemokines and chemokine receptors, CXCL1/GRO-alpha, CXCL2/GRO-beta, CXCL5/ENA-78, CXCL6/GCP2, IL-8/CXCL8, CXCL12/SDF-1, CXCL9/Mig, CXC11/ITAC, CX3CL1/fractalkine, CCL2/MCP-1, CCL3, CCL5/RANTES, CCL7, CCL15, CCL21, CCL23, CCL28, and CCR1, CCR9, CXCR4 were identified. Moreover, these genes demonstrated different changing patterns during the capillary morphogenesis, which implied that they might have different roles in the sequential process. Among the chemokines identified, CCL2/MCP-1, CCL5/RANTES and CX3CL1 were specially up-regulated at the 24-h time point when the sprouting characterized the morphological change. It was thus suggested that they might exert crucial roles at the early stage of angiogenesis. CONCLUSION: The present study demonstrates a global profile of gene expression during endothelial capillary morphogenesis, and the results provide us much information about the molecular mechanisms of angiogenesis, with which further evaluation of individual genes can be conducted.

Cell Culture Techniques↗

PubMed2005

In vitro differentiation of mouse bone marrow mononuclear cells into hepatocyte-like cells.

AIM: : It is imperative to explore some ways to gain the functional hepatocytes for hepatocyte transplantation. Bone marrow stem cells can differentiate into hepatocytes in vivo and in vitro. We select fibroblast growth factor-4 (FGF-4), oncostatin M (OSM), hepatocyte growth factor (HGF) and epithermal growth factor (EGF) as differentiation factors, and design the appropriate directed differentiation medium in order to gain hepatocytes through directed differentiation of bone marrow stem cells. METHODS: : Bone marrow mononuclear cells (BMMCs) were cultured in the directed differentiation media including FGF-4, OSM, HGF and EGF. In the course of cell differentiation, cell morphology was observed, and the expression patterns of some genes of the hepatocyte were validated and confirmed by RT-PCR. The ALB-, and CK18-expressed cells were gone further step to be confirmed by Western blot analysis, immunofluorescence and flow cytometric analysis. Hepatocyte functional activity, including glycogen synthesis and urea production, were confirmed by periodic acid-Shiff (PAS) staining and urea assay. RESULTS: : Some epithelial-like cells or polygonal cells appeared in the directed differentiation medium within 12 days, and the number and sizes of colonies of epithelial-like cells or polygonal cells increased in the course of the cell directed differentiation. AFP, HNF-3ss, ALB and CK18 mRNA expressions first appeared within day 7, and lasted throughout the later directed differentiation. TTR, G-6-P and TAT mRNA expressions could be detected within day 14, and their expressions lasted in the course of the later directed differentiation. ALB and CK18 were confirmed to exist in the differentiated BMMCs by Western blot analysis. ALB was found in the cytoplasm and cell membrane, while CK18 scattered in the cytoplasm by immunofluorescent staining. On day 21,the ratio of ALB-positive cells was 69.45%, and the ratio of CK18-positive cells was 67.36%. The accumulation of glucogen was detected in the cytoplasm of the differentiated cells. The directed differentiated BMMCs produced urea 3 days later, and they produced urea in a time-dependent manner. CONCLUSIONS: : BMMCs could differentiate into hepatocytes or hepatocyte-like cells in the differentiation media including HGF, FGF-4, EGF, and OSM. These hepatocyte-like cells were identified at the gene level and protein level. Furthermore, these hepatocyte-like cells had some hepatocellular synthesis and metabolism functions.

Journal Article↗

PubMed2004

In vivo suppressive effect of nuclear factor-kappaB inhibitor on neutrophilic inflammation of grafts after orthotopic liver transplantation in rats.

AIM: To investigate the effect of pyrrolidine dithiocarbamate (PDTC), a novel nuclear factor-kappaB (NF-kappaB) inhibitor, on expression of multiple inflammatory mediators and neutrophilic inflammation of cold preserved grafts after rat liver transplantation and its significance. METHODS: Orthotopic liver transplantation (OLT) was performed after 24 h of cold storage using University of Wisconsin solution with varied concentrations of PDTC. We determined the time course of NF-kappaB activation and expression of multiple inflammatory signals, such as tumor necrosis factor-alpha (TNF-alpha), cytokine-inducible neutrophil chemoattractant (CINC), and intercellular adhesion molecule-1 (ICAM-1) by ELISA methods. Serum alanine aminotransferase (ALT), intrahepatic myeloperoxidase (MPO)/WBC (a measure of neutrophil accumulation) and Mac-1 expression (a measure of circulating neutrophil activity) were also evaluated. RESULTS: PDTC decreased NF-kappaB activation induced by prolonged cold preservation in a dose dependent manner (from 20 mmol/L to 60 mmol/L), diminished TNF-alpha, CINC, ICAM-1 proteins in the grafts, and reduced the expression of increases in plasma TNF-alpha levels induced by prolonged cold preservation. Neutrophilic inflammation of the graft was significantly suppressed after preservation with PDTC (P<0.05). The total neutrophil accumulation in PDTC (40 mmol/L) group (7.04+/-0.97) was markedly reduced compared to control group (14.07+/-1.31) (P<0.05). Mac-1 expression was significantly reduced in PDTC (40 mmol/L) group (181+/-11.3%) compared with the control group (281+/-13.2%) (P<0.05) at 6 h after reperfusion. Furthermore, PDTC inhibited the increased serum ALT levels after liver transplantation. CONCLUSION: PDTC can inhibit B NF-kappaB activation and expression of the inflammatory mediators, which are associated with improved graft viability via inhibiting intrahepatic neutrophilic inflammation. Our study suggests that a therapeutic strategy directed at inhibition of NF-kappaB activation in the transplanted liver might be effective in reducing intrahepatic neutrophilic inflammation, and would be beneficial to cold preserved grafts.

Animals↗

PubMed2004

Angiogenic synergistic effect of basic fibroblast growth factor and vascular endothelial growth factor in an in vitro quantitative microcarrier-based three-dimensional fibrin angiogenesis system.

AIM: To develop an in vitro three-dimensional (3-D) angiogenesis system to analyse the capillary sprouts induced in response to the concentration ranges of basic fibroblast growth factor (bFGF) and vascular endothelial growth factor (VEGF) and to quantify their synergistic activity. METHODS: Microcarriers (MCs) coated with human microvascular endothelial cells (HMVECs) were embedded in fibrin gel and cultured in 24-well plates with assay media. The growth factors bFGF, or VEGF, or both were added to the system. The wells (n = 8/group) were digitally photographed and the average length of capillary-like sprouts (ALS) from each microcarrier was quantitated. RESULTS: In aprotinin-stabilized fibrin matrix, human microvascular endothelial cells on the MCs invaded fibrin, forming sprouts and capillary networks with lumina. The angiogenic effects of bFGF or VEGF were dose-dependent in the range from 10 to 40 ng/mL. At d 1, 10 ng/mL of bFGF and VEGF induced angiogenesis with an ALS of 32.13 +/- 16.6 microm and 43.75 +/- 27.92 microm, respectively, which were significantly higher than that of the control (5.88 +/- 4.45 microm, P<0.01), and the differences became more significant as the time increased. In addition, the combination of 10 ng/mL of bFGF and VEGF each induced a more significant effect than the summed effects of bFGF (10 ng/mL) alone and VEGF (10 ng/mL) alone when analyzed using SPSS system for general linear model (GLM) (P = 0.011), and that also exceeded the effects by 20 ng/mL of either bFGF or VEGF. CONCLUSION: A microcarrier-based in vitro three-dimensional angiogenesis model can be developed in fibrin. It offers a unique system for quantitative analysis of angiogenesis. Both bFGF and VEGF exert their angiogenic effects on HMVECs synergistically and in a dose-dependent manner.

Capillaries↗

PubMed2004

Rat liver transplantation without preservation of "phrenic ring" using double cuff method.

AIM: To develop a double cuff method for rat liver transplantation without preservation of "phrenic ring" to shorten the portal vein clamping time. METHODS: "Phrenic ring" was completely excluded from the donor liver, and end to end anastomosis of suprahepatic inferior vena cava was performed. RESULTS: The portal vein clumping time was shortened to 10.6 min, the successful rate was 83.1%. CONCLUSION: This method can simplify the operation and shorten the portal vein clumping time.

Animals↗

PubMed2004

Effect of cold-ischemia time on nuclear factor-kappaB activation and inflammatory response in graft after orthotopic liver transplantation in rats.

AIM: To study the mechanism and effect of nuclear factor-kappaB (NF-kappaB) activation and inflammatory response on the extended cold-preserved graft injury after orthotopic liver transplantation (OLT). METHODS: OLT was performed in rats with varying time of cold ischemia grafts (6, 18 and 24 h in University Wisconsin solution at 4 degrees ). We determined the time of NF-kappaB activation and expression of tumor necrosis factor-alpha (TNF-alpha), cytokine-inducible neutrophil chemoattractant (CINC), and intercellular adhesion molecule-1 (ICAM-1) within 6 h after reperfusion. Serum alarming aminotransferase (ALT), neutrophil sequestration, circulating neutrophil CD11b and L- selectin expression were also evaluated. RESULTS: The accumulation of neutrophils in the graft was significantly increased in the 18 h and 24 h cold-ischemia groups within 0.5 h after reperfusion, compared with the 6 h group. But the strongly activated neutrophils was slightly increased at 2 h after reperfusion and remained at high levels 4 h after reperfusion, which was synchronized with the common situation of recipients after transplantation. Prolonged cold-preservation did not affect neutrophil accumulation and activation. NF-kappaB activation preceded the expression of TNF-alpha, CINC, and ICAM-1 in the liver, which was significantly increased with prolonged cold preservation. In prolonged cold preserved grafts, prominently elevated NF-kappaB activation occurred at 0.5 h and 1 h, compared with that at 2 h after reperfusion, which was consistent with greatly increased intrahepatic TNF-alpha response. CONCLUSION: NF-kappaB activation is correlated with the expression of TNF-alpha, CINC, and ICAM-1 in vivo in OLT rats. Extended cold preservation of grafts might up-regulate TNF-alpha, CINC, and ICAM-1 expression in the grafts, most probably through elevated NF-kappaB activation, and might contribute to neutrophil infiltration in the grafts after reperfusion. Elevated NF-kappaB activity is harmful to inflammatory response in the grafts, and inhibited NF-kappaB activity might protect against early graft injury after liver transplantation.

Animals↗

PubMed2004

A reliable graded acute liver failure model in rats: treatment with internal bioartificial liver.

BACKGROUND: Appropriate animal models are important for studying acute liver failure. This study was to assess a new suitable rat model for acute liver failure. METHODS: After the right influent hepatic vessels were clamped for a period of time (45, 60 or 90 minutes respectively), the animal model was established by removal of the clamp for restoring blood flow of the right lobes while immediately removal of the median, left lateral and caudate lobes. Animal survival rate was observed in the following 14 days in each group. To study the pathophysiological changes of the model, some biochemical parameters in 5 consecutive days were evaluated in the 60-minute group. Internal bioartificial liver was transplanted in the peritoneal cavity to test the reversibility of the model. RESULTS: The survival rate of the models decreased, as the ischemia time of the right lobes prolonged to zero in the 90-minute group, to 50% in the 60-minute group and to 100% in the 45-minute group on the fifth day after operation. The levels of ammonia, alanine aminotransferase, alkaline phosphatase, total bilirubin and prothrombin were elevated dramatically 12 to 24 hours after operation in the 60-minute group. When internal bioartificial liver was transplanted, the survival rate increased significantly in addition to the levels of ammonia and total bilirubin. CONCLUSION: A period time of ischemic injury in the right lobe followed by 70% liver resection can produce a graded acute hepatic failure model in rats.

Animals↗

PubMed2004

Pyrrolidine dithiocarbamate added to University of Wisconsin solution inhibits reperfusion injury after orthotopic liver transplantation in rats.

This study investigated the effects of pyrrolidine dithiocarbamate (PDTC), a novel NF-kappaB inhibitor, on the expression of multiple inflammatory mediators and on neutrophilic inflammation of the graft in rats following liver transplantation. Orthotopic liver transplantation (OLT) was performed after 24 hr of cold storage using University of Wisconsin (UW) solution that contained various concentrations of PDTC. We determined the time course of NF-kappaB activation and of the expression of multiple inflammatory signals: tumor necrosis factor-alpha (TNF-alpha), cytokine-inducible neutrophil chemoattractant (CINC), and intercellular adhesion molecule-1 (ICAM)-1. Serum alanine aminotransferase (ALT), intrahepatic myeloperoxidase (MPO/WBC ratio, a measure of neutrophil accumulation), and Mac-1 expression (CD11b/CD18, a measure of circulating neutrophil activity) were also evaluated. The results showed that PDTC decreased OLT-induced NF-kappaB activation in a dose-dependent manner (from 20 mmol/L to 60 mmol/L), diminished TNF-alpha, CINC, and ICAM-1 protein levels in the graft, and reduced the OLT-induced increase of serum TNF-alpha level. Pretreatment with PDTC significantly suppressed OLT-induced neutrophilic inflammation of the graft. The PDTC-exposed livers (PDTC, 40 mmol/L), in comparison with the control livers, had a significant reduction of MPO/WBC ratio (7.04+/-0.97 vs 14.07+/-1.31) and Mac-1 expression (181+/-11.3% vs 281+/-13.2%) at 6 hr after reperfusion. Furthermore, PDTC inhibited the increase of serum ALT levels after liver transplantation. In conclusion, PDTC inhibited NF-kappaB activation and the expression of the inflammatory mediators. These effects were associated with improved graft viability through inhibited intrahepatic neutrophilic inflammation. A therapeutic strategy directed at inhibition of NF-kappaB activation within the transplanted liver might be effective in reducing intrahepatic neutrophilic inflammation, and be beneficial to prolonged graft storage.

Adenosine↗

PubMed2004

Molecular adsorbent recycling system in treating patients with acute liver failure: a bridge to liver transplantation.

BACKGROUND: Acute liver failure is still a life-threatening disease although it can be treated by liver transplantation. This study was conducted to assess the molecular adsorbent recycling system (MARS), which may bridge acute liver failure patients to liver transplantation. METHODS: Biochemical indexes and other clinical data were analyzed of 8 patients with acute liver failure, who had been treated by MARS for 34 times and subsequent Piggyback liver transplantation. RESULTS: After treatment with MARS, the levels of transaminase and total bilirubin decreased markedly, but coagulation function remained unimproved. All patients survived and discharged from the hospital. CONCLUSION: MARS is effective in bridging patients with acute liver failure to liver transplantation.

Acute Disease↗

PubMed2003

The development of a new bioartificial liver and its application in 12 acute liver failure patients.

AIM: Bioartificial liver is a hope of supporting liver functions in acute liver failure patients. Using polysulfon fibers, a new bioartificial liver was developed. The aim of this study was to show whether this bioartificial liver could support liver functions or not. METHODS: Hepatocytes were procured from swine using Seglen's methods. The bioartificial liver was constructed by polysulfon bioreactor and more than 10(10) hepatocytes. It was applied 14 times in 12 patients, who were divided into 7 cases of simultaneous HBAL and 5 cases of non-simultaneous HBAL. Each BAL treatment lasted 6 hours. The general condition of the patients and the biochemical indexes were studied. RESULTS: After treatment with bioartificial liver, blood ammonia, prothrombin time and total bilirubin showed significant decrease. 2 days later, blood ammonia still showed improvment. within one month period, 1 case (1/7) in simultaneous group died while in non-simultaneous group 2 cases (2/5) died. The difference was significant. Mortality rate was 25 %. CONCLUSION: The constructed bioartificial liver can support liver functions in acute liver failure. The simultaneous HBAL is better than non-simultaneous HBAL.

Adolescent↗

PubMed2003

Ischemic preconditioning decreases C-X-C chemokine expression and neutrophil accumulation early after liver transplantation in rats.

AIM: Polymorphonuclear neutrophil (PMN) plays a major role in liver ischemia/reperfusion injury. Protective effect of ischemic preconditioning (IP) has been confirmed in liver ischemia/reperfusion injury. The purpose of this study was to investigate the effect of IP on C-X-C chemokine expression and PMNs recruitment early after liver transplantation. METHODS: Male Sprague-Dawley rats were used as donors and recipients of orthotopic liver transplantation (OLT). The donor liver was stored 24 hours in University of Wisconsin (UW) solution at 4 degrees pre-implantation. IP was done by clamp of the portal vein and hepatic artery of the donor liver for 10 minutes followed by reperfusion for 10 minutes before harvesting. The neutrophilic infiltration in liver was quantified using a myeloperoxidase (MPO) assay. Intragraft expression of macrophage inflammatory protein-2 (MIP-2) mRNA was investigated with in situ hybridization. The serum levels of MIP-2 and tumor necrosis factor (TNF)-alpha were also monitored. RESULTS: After liver transplantation without IP, the hepatic MPO increased significantly compared with sham operated group. In IP group, PMN in liver indicated by MPO was reduced significantly. In situ hybridization showed no MIP-2 mRNA in sham group but dramatic expression in hepatocytes in non-IP group. In IP group, MIP-2 mRNA was significantly down-regulated. Similarly, serum MIP-2 and TNF-alpha levels were significantly elevated in non-IP group and both were reduced in IP group. CONCLUSION: IP might protect graft liver from preservation-reperfusion injury after OLT through down-regulating C-X-C chemokine expression of hepatocytes, and alleviating PMNs recruitment after reperfusion.

Animals↗

PubMed2003

Effect of matrine on cold ischemia and reperfusion injury of sinusoidal endothelial cells in rat orthotopic liver transplantation.

AIM: To study the mechanism and prevention of matrine (Mat) on cold ischemia/reperfusion injury of sinusoidal endothelial cells (SEC) in rat orthotopic liver transplantation (OLT). METHODS: One hundred and twenty-six syngeneic SD rats were randomly divided into four groups (n=18): untreated group, 40 mg/kg treated group, 80 mg/kg treated group, and pseudo-treated group. After 5 h of preservation in Ringer's (LR) solution, orthotopic implantation of the donor liver was performed. At 1, 2, and 4 h after reperfusion of the portal vein, 6 rats were killed in each group to collect the serum and the median lobe of liver for assay. RESULTS: The level of hylluronic acid (HA) and intercellular adhesion molecule-1 (ICAM-1) decreased significantly in both treated groups at different times post-transplantation, and their pathological changes of SEC were ameliorated, too. CONCLUSION: Matrine can prevent SEC from ischemia and reperfusion injury in rat orthotopic liver transplantation.

Alkaloids↗

PubMed2002

Effect of matrine on Kupffer cell activation in cold ischemia reperfusion injury of rat liver.

AIM: To study the effect of matrine on activation of Kupffer cell during cold ischemia and reperfusion injury in rat orthotopic liver transplantation (OLT). METHODS: 168 syngeneic SD rats were randomly divided into four groups: untreated group, small-dose treated group, large-dose treated group and sham operation group. After 5 hours of preservation in Ringer's (LR) solution, orthotopic implantation of the donor liver was performed. At 1 h, 2 h, 4 h and 24 h after reperfusion of the portal vein, 6 rats were killed in each group to collect the serum and the liver for assay and pathology. RESULTS: Matrine markedly inhibited the activation of Kupffer cells and their release of tumor necrosis factor (TNF). TNF cytotoxicity level at 2 h decreased significantly by matrine treatment (7.94+/-0.42, 2.39+/-0.19 and 2.01+/-0.13 U/ml, respectively; P<0.01), so did the other three time points. The level of hylluronic acid (HA) and alanine transaminase (ALT) decreased significantly in both treated groups, and matrine treatment markedly ameliorated focal necrosis of hepatocytes, inflammatory cells aggregating, rounding and detachment of sinusoidal endothelial cells (SEC). And no significant difference was observed between the treated groups. CONCLUSION: Matrine can inhibit the activation of Kupffer cell and prevent the donor liver from cold preservation and reperfusion injury in rat orthotopic liver transplantation.

Alanine Transaminase↗