Objective To summarize and review the heterogeneity of bone marrow derived stem cells (BMDSCs) and its formation mechanism and significance, and to analyze the possible roles and mechanisms in intestinal epithel ial reconstruction. Methods The related l iterature about BMDSCs heterogeneity and its role in intestinal epithel ial repair was reviewed and analyzed. Results The heterogeneity of BMDSCs provided better explanations for its multi-potency. The probable mechanisms of BMDSCs to repair intestinal epithel ium included direct implantation into intestinal epithel ium, fusion between BMDSCs and intestinal stem cells, and promotion of injury microcirculation reconstruction. Conclusion BMDSCs have a bright future in gastrointestinal injury caused by inflammatory bowl disease and regeneration.
Objective To study the effect of myofibroblast on the development of pathological scar. Methods From 1998 to 2000， 14 cases of keloid(k), 13 cases of hypertrophic scar(HS), and 7 cases of scar were studied through immunohistochemistry and electronical microscope. Results Myofibroblasts were often observed in the hypertrophic HS by electronical microscope, but no myofibroblast was observed in the K and NS. αSMactin was expressed in fibroblast of HS, but was not expressed in K and NS. Conclusion Myofibroblast may play a role in the development of hypertrophic scar. The difference between the absence of myofibroblast in keloid and the invasion of keloid deserves further study.
OBJECTIVE To study the influence and mechanism of gamma-IFN on fibroblasts in hypertrophic scars(HTS). METHODS The cultured fibroblastic cells were isolated from the hypertrophic scars of 10 patients. The fibroblasts were divided into two groups, one group was treated with gamma-IFN (100 U/ml, 5 days) and the other without gamma-IFN as control. The proliferative activity in both groups was investigated and compared by blood cytometer, the proportion of myofibroblast (MFB) and the ratio of apoptosis were examined and analysed between two groups by flow cytometry using alpha-smooth muscle actin (alpha-SMA) as marker. RESULTS The proliferative activity was downregulated with gamma-IFN. In gamma-IFN treated group, the differentiation of MFB were reduced and the decreasing ratio was 3.2% at the 2nd day and up to 10.5% at the 8th day, then it reduced gradually. The apoptosic ratio is 17.7% in gamma-IFN treated group, and is 10.9% in control group. The difference was statistically significant. CONCLUSION gamma-IFN could downregulate the proliferation of fibroblasts, decrease the differentiation of MFB and induce the apoptosis. It has beneficial effect in the treatment of hypertrophic scars(HTS).
Objective To investigate the expression of vascular endothelial growth factor-A （VEGF-A） and the phenotypic transition after the activation of fibroblasts by the supernatant of cultured tumor cells．Methods The growth tendency of fibroblasts was tested by the MTT assay．The expressions of alpha-smooth muscle actin （α-SMA） and VEGF-A mRNA were tested by RT-PCR．The expressions of α-SMA and VEGF-A protein were tested by immunohistochemistry and Western blot．Results The MTT assay indicated that the conditional medium which contained tumor cells supernatant could obviously promote the growth of the fibroblasts． RT-PCR and Western blot manifested that α-SMA expressed by the fibroblasts which cultured by normal medium reached its peak on day 5，then decreased to a low level on day 7．When the medium contained 2 ng/ml transforming growth factor-β1 （TGF-β1），the fibroblasts could steadily express more α-SMA．But the above two mediums could not make the fibroblasts express the VEGF-A. When using the conditional medium，the α-SMA peak advanced on the third day and maintained at a high level，so as the expression of the VEGF-A．Conclusions The results suggested that fibroblasts can be activated to be myofibroblasts when using the conditional medium．The best activation time of the fibroblasts is consistent with the time of the VEGF-A expression at the highest level by the activated fibroblasts．The fibroblasts which activated at the best time are expected to become a kind of cells which can be used for promoting revascularization．
ObjectivePulmonary vein banding was used to establish a piglet model of pulmonary vein stenosis. We investigated the pathomorphological alterations of pulmonary veins in the model and compared it with the vascular tissue of recurrent stenosis after total anomalous pulmonary venous connection (TAPVC).MethodsTen pigs of 6 weeks old were selected and randomly divided into 2 groups: 5 in a sham operation group and 5 in a pulmonary vein banding group. The operation had two stages, in which thoracotomies through intercostal space were done respectively on both sides. Biocompatible materials were applied around the pulmonary veins in the experimental group. The same method was used in the sham group. But the pulmonary veins were not banded. Six weeks after the operation, the pulmonary veins of the animals were harvested for hematoxylin-eosin staining and immunofluorescence staining to observe the pathological alterations of pulmonary veins. The proliferative tissues of patients with recurrent stenosis after TAPVC repair were collected and observed by hematoxylin-eosin staining and immunofluorescence staining.ResultsBoth the sham operation group and the pulmonary vein banding group survived. But the pulmonary vein banding group had obvious clinical manifestations of pulmonary venous stenosis. Compared with the sham group, the pulmonary vein banding group showed intimal hyperplasia, decreased expression of endothelial marker and increased expression of mesenchymal markers, and co-expression of endothelial and mesenchymal markers in intimal cells. Human pathology also showed intimal hyperplasia and co-expression of endothelial and mesenchymal markers in intimal cells.ConclusionThe surgical pulmonary vein stenosis in piglets shows intimal hyperplasia and myofibroblasts, which was consistent with clinical pathology.
Calnexin is a lectin-like molecular chaperone protein on the endoplasmic reticulum, mediating unfolded protein responses, the endoplasmic reticulum Ca2+ homeostasis, and Ca2+ signals conduction. In recent years, studies have found that calnexin plays a key role in the heart diseases. This study aims to explore the role of calnexin in the activation of cardiac fibroblasts. A transverse aortic constriction (TAC) mouse model was established to observe the activation of cardiac fibroblasts in vivo, and the in vitro cardiac fibroblasts activation model was established by transforming growth factor β1 (TGFβ1) stimulation. The adenovirus was respectively used to gene overexpression and silencing calnexin in cardiac fibroblasts to elucidate the relationship between calnexin and cardiac fibroblasts activation, as well as the possible underlying mechanism. We confirmed the establishment of TAC model by echocardiography, hematoxylin-eosin, Masson, and Sirius red staining, and detecting the expression of cardiac fibrosis markers in cardiac tissues. After TGFβ1 stimulation, markers of the activation of cardiac fibroblast, and proliferation and migration of cardiac fibroblast were detected by quantitative PCR, Western blot, EdU assay, and wound healing assay respectively. The results showed that the calnexin expression was reduced in both the TAC mice model and the activated cardiac fibroblasts. The overexpression of calnexin relieved cardiac fibroblasts activation, in contrast, the silencing of calnexin promoted cardiac fibroblasts activation. Furthermore, we found that the endoplasmic reticulum stress was activated during cardiac fibroblasts activation, and endoplasmic reticulum stress was relieved after overexpression of calnexin. Conversely, after the silencing of calnexin, endoplasmic reticulum stress was further aggravated, accompanying with the activation of cardiac fibroblasts. Our data suggest that the overexpression of calnexin may prevent cardiac fibroblasts against activation by alleviating endoplasmic reticulum stress.
Long non-coding RNA (lncRNA) Dnm3os plays a critical role in peritendinous fibrosis and pulmonary fibrosis, but its role in the process of cardiac fibrosis is still unclear. Therefore, we carried out study by using the myocardial fibrotic tissues obtained by thoracic aortic constriction (TAC) in an early study of our group, and the in vitro cardiac fibroblast activation model induced by transforming growth factor-β1 (TGF-β1). Quantitative real-time polymerase chain reaction (RT-qPCR), Western blot, and collagen gel contraction test were used to identify the changes of activation phenotype and the expression of Dnm3os in cardiac fibroblasts. Small interfering RNA was used to silence Dnm3os to explore its role in the activation of cardiac fibroblasts. The results showed that the expression of Dnm3os was increased significantly in myocardial fibrotic tissues and in the activated cardiac fibroblasts. And the activation of cardiac fibroblasts could be alleviated by Dnm3os silencing. Furthermore, the TGF-β1/Smad2/3 pathway was activated during the process of cardiac fibroblasts activation, while was inhibited after silencing Dnm3os. The results suggest that Dnm3os silencing may affect the process of cardiac fibroblast activation by inhibiting TGF-β1/Smad2/3 signal pathway. Therefore, interfering with the expression of lncRNA Dnm3os may be a potential target for the treatment of cardiac fibrosis.