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Lingsong Li

Publications and source records attributed to Lingsong Li.

20 records · Page 2Linked to original sources
PubMed2003

[Transplantation of bone marrow cells up-regulated the expressions of HSP32 and HSP70 in the acute ischemic myocardium].

OBJECTIVE: To clarify the role of Heat shock proteins (HSPs) on the cardiac function during acute myocardial infarction (AMI) after bone marrow cell implantation (BMT), we examined the expression of HSP32 and HSP70 in a rat model of myocardial infarction. METHODS: Myocardial infarction model was induced in the inbred Lewis rats by left anterior descending artery ligation, and 5 x 10(6) of bone marrow-mononuclear cells (BM-MNCs) were injected into an ischemic zone. On days 1, 3, 7 and 14 post-infarct, the differentiations of transplanted cells and the expressions of HSP32 and HSP70 were determined by immunofluorescence or RT-PCR. The cardiac function was evaluated by echocardiography. RESULTS: Immunofluorescence microscopy of hearts from BMT group revealed that expressions of HSP32 and HSP70 were promoted within cardiomyocytes in the infarction zone and the peri-infarct zone, and expressed within some transplanted bone marrow cells as well. RT-PCR also showed the mRNA expression levels of HSP32 and HSP70 in BMT group were significantly higher than those of the control group, peaked on day 3 post-infarct (5.0-fold and 2.9-fold, respectively, P < 0.01), and then gradually reduced. On day 7 post-infarct, cardiac function (EF and FS) was improved, more than that of the control group (14% and 22%, P < 0.05). On day 14 post-infarct, the specific markers for myocardium or vascular endothelial cells were detected in the transplanted bone marrow cells. The cardiac function was further improved in the BMT group (P < 0.01). CONCLUSION: At the early phase after BMT, the expressions of HSP32 and HSP70 were upregulated in both transplanted cells and recipient endogenous cardiomyocytes, which improved the acute ischemic cardiac function.

Animals↗
PubMed2003

Hepatic differentiation from embryonic stem cells in vitro.

OBJECTIVE: To investigate an method for hepatic differentiation from embryonic stem cells (ES cells) in vitro and the resulting differentiation ratio, in order to develop a procedure for producing a new type of hepatocyte for hepatocyte replacement therapy in the treatment of liver failure. METHODS: ES cells from Balb/C mice were cultured and maintained in an undifferentiated state in gelatin-coated dishes using Dulbecco's modified Eagle's medium (DMEM) containing 1000 U/ml leukemia inhibitory factor (LIF). Then, LIF was withdrawn from the DMEM to allow the ES cells to develop into embryonic bodies (EBs). EBs were plated onto tissue culture dishes, and growth factors such as acidicfibroblast growth factor (aFGF) and hepatocyte growth factor (HGF) were added to the medium to promote directional differentiation. The course of development and differentiation was observed dynamically using an inversion microscope. The expression of hepatic proteins, such as alpha-fetoprotein (AFP), albumin (ALB), cytokeratin 8 (CK8), cytokeratin 18 (CK18), in cytoplasm was analyzed by immunocytochemistry (ICC). The concentration of ALB in the medium was determined dynamically by radioimmunoassay (RIA). RESULTS: ES cells replicated as clones, without differentiating, in DMEM containing LIF. They developed into EBs in medium without LIF. Our ICC assay showed that differentiating cells did not express hepatic proteins, such as AFP, ALB, CK8, and CK18 until day 7, day 9, day 11, and day 11, respectively (up to 2 days later when growth factors are not present). The concentration of AFP in the medium was first detected on day 8, at a concentration of 3.4 ng/ml, and increased to 22.8 ng/ml by day 15. The concentration of ALB in the medium was 0.2 micro g/ml on day 11, and increased to 2.2 micro g/ml by day 15. ALB-positive cells under ICC manifest morphological structures were consistent with normal mouse hepatocytes. The differentiation ratio of hepatocytes in the ES cell differentiation system was 30% on day 15 (significantly lower without the presence of growth factors). CONCLUSIONS: ES cells can differentiate into mature hepatocytes. Growth factors, such as aFGF and HGF, can enhance this differentiation and produce sufficient numbers of functional hepatocytes. This method may be a reliable new way of differentiating ES cells into hepatocytes for use in replacement therapy in the treatment of liver failure.

Animals↗