ABSTRACT
Objective: To investigate the effect of Liuwei Dihuangwan on connexin 32 (Cx32) in hepatoma cell line CBRH7919 and its gap junction intercellular communication (GJIC), and furthermore study its mechanism of enhancing the bystander killing effect of suicide gene therapy. Method: Liuwei Dihuangwan (32 g·kg·d-1) and the same volume of normal saline were given to the rats by intragastrical administration. Blood was taken to prepare the medicated serum of Liuwei Dihuangwan and blank control serum, respectively. The hepatoma cell line CBRH7919 were treated by control serum and medicated serum of Liuwei Dihuangwan in different concentrations. There were four groups in experiment:the blank control group (volume fraction of 10%), medicated serum high dose group of Liuwei Dihuangwan (the volume fraction of 10%), medicated serum middle dose group of Liuwei Dihuangwan (the volume fraction of 5%), and medicated serum low dose group of Liuwei Dihuangwan (the volume fraction of 2.5%). The expression levels of Cx32 protein and mRNA in hepatoma cell line CBRH7919 were detected by indirect immunofluorescence assay (ⅡA) and Real-time fluorescence quantitative polymerase chain reaction (Real-time PCR) assay. The fluorescence redistribution after photobleaching (FRAP) method was used to detect the function of GJIC of hepatoma cell line CBRH7919. Result: ① The indirect immunofluorescence assay (ⅡA) analysis indicated that as compared with the blank control group, the cx32 expression of CBRH7919 cells was up-regulated in a concentration-dependent manner in each dose group of the serum containing Liuwei Dihuangwan (PPPPConclusion: The mechanism of medicated serum of Liuwei Dihuangwan in enhancing the bystander killing effect of suicide geneis related to gap junction. Liuwei Dihuangwan may enhance the function of GJIC by increasing the localization of cx32 on the cell membrane of CBRH7919 cells and increasing the expression of cx32 mRNA and protein to achieve the synergistic action.
ABSTRACT
<p><b>BACKGROUND</b>Endothelial and smooth muscle cells were used as seeding cells and heterogeneous acellularized matrix was used as scaffold to construct the tissue-engineered graft.</p><p><b>METHODS</b>A 2 weeks piglet was selected as a donor of seeding cells. Two-centimetre length of common carotid artery was dissected. Endothelial cells and smooth muscle cells were harvested by trypsin and collagenase digestion respectively. The isolated cells were cultured and expanded using routine cell culture technique. An adult sheep was used as a donor of acellularized matrix. The thoracic aorta was harvested and processed by a multi-step decellularizing technique to remove the original cells and preserve the elastic and collagen fibers. The cultured smooth muscle cells and endothelial cells were then seeded to the acellularized matrix and incubated in vitro for another 2 weeks. The cell seeded graft was then transplanted to the cell-donated piglet to substitute part of the native pulmonary artery.</p><p><b>RESULTS</b>The cultured cells from piglet were characterized as endothelial cells by the presence of specific antigens vWF and CD31, and smooth muscle cells by the presence of specific antigen alpha-actin on the cell surface respectively with immunohistochemical technique. After decellularizing processing for the thoracic aorta from sheep, all the cellular components were extracted and elastic and collagen fibers kept their original morphology and structure. The maximal load of acellular matrix was decreased and 20% lower than that of untreated thoracic aorta, but the maximal tensions between them were not different statistically and they had similar load-tension curves. Three months after transplantation, the animal was sacrificed and the graft was removed for observation. The results showed that the inner surfaces of the graft were smooth, without thrombosis and calcification. Under microscopy, a great number of growing cells could be seen and elastic and collagen fibers were abundant.</p><p><b>CONCLUSION</b>Cultured self-derived endothelial and smooth muscle cells could be used as seeding cells and heterogeneous acellularized matrix could be used as scaffold in constructing tissue-engineered graft.</p>