Negative pressure promotes epidermal differentiation of bone marrow mesenchymal stem cells / 中国组织工程研究

BACKGROUND: As a physical factor, negative pressure can promote the osteogenic differentiation and endothelial differentiation of mesenchymal stem cells. If a negative pressure exerts effects on the epidermal differentiation of mesenchymal stem cells, it will be highly important for the combination use of negative pressure and mesenchymal stem cells in wound healing. OBJECTIVE: To explore the effect of negative pressure on the epidermal differentiation of bone marrow mesenchymal stem cells. METHODS: Bone marrow mesenchymal stem cells of New Zealand white rabbits were isolated and cultured. Then, the passage 3 cells were induced for epidermal differentiation under negative pressure (-16.625 kPA, twice a day, once for 4 hours) as experimental group. Another cells induced under no negative pressure were used as control group. After induction, cell growth curve was drawn in each group, and the expression of cytokeratin 5 and cytokeratin 10 mRNA was examined by real-time PCR at 2 weeks after induction. RESULTS AND CONCLUSION: The cell growth of the experimental group was inhibited, and the mRNA expression of cytokeratin 5 and cytokeratin 10 was significantly increased compared with the control group (P < 0.05). These findings indicate that under the condition of negative pressures, the epidermal differentiation ability of bone marrow mesenchymal stem cells is increased, and in contrary, the cell proliferation is inhibited.

Pericyst may be a new pharmacological and therapeutic target for hydatid disease / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Most hydatid cysts with calcified walls are biologically and clinically silent and inactive. Transforming growth factor-beta 1 (TGF-β1) plays a critical role in the calcification process of cells. The aim of this study was to assess the effect of modulating TGF-β1 signaling on the calcification of hydatid cysts.</p><p><b>METHODS</b>Pericyst cells isolated from hepatic hydatid cysts were cultured with osteogenic media. These cells were assessed for alkaline phosphatase activity and mineralization capacity using Alizarin Red staining. Cells were also treated with recombinant human TGF-β1 and TGF-β inhibitor, and the expression profiles of osteoblast markers (RUNX2, osterix, and osteocalcin) were analyzed using Western blotting. The effects of inhibiting TGF-β1 signaling on calcification of pericyst walls were assessed using different doses of TGF-β inhibitor for 7 weeks in a preclinical disease model of liver cystic echinococcosis.</p><p><b>RESULTS</b>Cells within the pericyst displayed high levels of alkaline phosphatase activity and mineralized nodule formation, as induced by osteogenic media. These activities, as well as expression profiles of osteoblast markers (RUNX2, osterix, and osteocalcin) could be inhibited by addition of recombinant human TGF-β1 (rhTGF-β1) and enhanced by TGF-β inhibitor. In the animal model of cystic echinococcosis, inhibition of TGF-β1 signaling increased calcification of the pericyst wall, which was associated with decreased cyst load index and lower viability of protoscoleces.</p><p><b>CONCLUSIONS</b>Cells within the pericysts adopt an osteoblast-like phenotype and have osteogenic potential. Inhibition of TGF-β1 signaling increases hydatid cyst calcification. Pharmacological modulation of calcification in pericysts may be a new therapeutic target in the treatment of hydatid disease.</p>

Effect of shRNAmir lentiviral vector-mediated COX-2 silencing on the radiosensitivity of nasopharyngeal carcinoma cells / 南方医科大学学报

<p><b>OBJECTIVE</b>To evaluate the effect of COX-2 silencing on the radiosensitivity of a nasopharyngeal carcinoma (NPC) cell line C666-1.</p><p><b>METHODS</b>Anti-COX-2 C666-1 cell line with COX-2 gene silencing mediated by shRNAmir lentiviral vector and the control cell line Anti-GL-2 C666-1 were exposed to various radiation doses. The clonogenic survival assay and curve fitting was used to calculate the radiobiological parameters and the sensitization enhancement ratio after the radiation. Cell cycle changes were assessed after the exposure by flow cytometric analysis. In a BALB/c nude mouse model, the growth curve of the xenografts was generated and the tumor growth inhibition rate was calculated.</p><p><b>RESULTS</b>Compared with the control cells, Anti-COX-2 C666-1 cells showed obviously lowered values of SF2, D0 and Dq but significantly increased α/β with a sensitivity enhancement ratio of 1.4014. COX-2 gene silencing increased the inhibition rate of the tumor xenografts after the radiation, and caused also decreased percentage of G2/M arrest resulting from the exposure.</p><p><b>CONCLUSION</b>Stable COX-2 silencing in NPC cells can improve the effect of radiotherapy both in vitro and in vivo. By changing the radiobiological parameters, genetically based COX-2 inhibitor may be a potentially promising radiosensitizer of NPC.</p>

[Explorative study on mechanism and drug intervention for chronic allograft nephropathy induced by renal ischemia-reperfusion injury].

OBJECTIVE: This study is aiming to investigate the mechanism and drug intervention of chronic allograft nephropathy (CAN) induced by renal ischemia-reperfusion injury. METHODS: The closed colony strain Sprague-Dawley (SD) and Wistar Rats were used as donor and recipient, respectively. Orthotopic kidney transplantation was performed following the procedure of our previous study. The rats were divided into five groups: Group A only received CsA with 10 mg/(kg x d); except CsA, Group B,C,D received Yi Sheng injection with 4 mg/(kg x d), 8 mg/(kg x d), and MMF (20 mg/(kg x d)], respectively. Group E was control group. According to Banff standard, the serum creatinine (SCr) level and pathological change of rat grafted kidney were observed at the 4th, 8th and 12th weeks post-transplantation. The immunohistochemistry and real-time fluorescence quantitative polymerase chain reaction were used to comprehend the localization and expression of TGFbeta1 and Smad2, 7 in the transplant kidney. RESULTS: Compared with the lower dosage group, the differences of SCr level and pathological changes of CAN at all the time points after 8th week were statistically significant in the high dosage Yi Sheng group. It was showed that the Yi Sheng injection had the protective effect on CAN with a dose-dependent fashion. After transplantation, the rat kidney-sclerosis model showed that the up-regulated expressions of TGF-P, and Smad2 and the down-regulated expression of Smad7 in Group A and Group B were statistically significant, which meant that the difference was obvious when Group A compared with the other 4 groups. The expressions of TGF-beta1, and Smad2 were strongly positive in tubular epithelial cell, interstitial cell and glomerulus, while the expression of Smad7 was weak. Thickening of endovascular could significantly be inhibited in high dosage of Yi Sheng and MMF group. CONCLUSION: The up-regulated expressions of TGF-beta1 and Smad2 and the down-regulated expression of Smad7 may accelerate the progression of CAN alone or with immune factors. The traditional Chinese medicine Yi Sheng injection and MMF can down-regulate the expression of TGF-beta1 and Smad2 and block the down-regulated expression of Smad7, which may postpone and lessen the progression of CAN.

[A new rat model of transplant kidney-sclerosis accelerated by prolonged cold ischemia time].

OBJECTIVE: To establish an accelerated animal model of the chronic renal allograft dysfunction in rat. METHODS: Kidney transplantation was performed from SD to Wistar strain (allogeneic) according to the procedure of Kamada with some modification. Before the transplantation, the kidney was preserved in 0-4 degrees C heparin sodium chloride solution for prolonging the one hour. The serum creatinine level and pathological change of transplant kidney were observed in the 2nd, 4th, 6th, 8th and 12th weeks post-transplantation. RESULTS: After transplantation, the serum creatinine level of recipient rats obviously increased in the 6th week and the pathologic changes of chronic nephropathy evidently appeared in the 8th week when compared to those of the control group with non-reinforcement I/R injury; a statistically significant difference was noted. CONCLUSION: It is simple and feasible to establish a rat model of (SD-->Wistar) transplant kidney-sclerosis accelerated by prolonging I/R injury.