Xenogenic organ transplantation has been considered the most promising strategy in providing possible substitutes with the physiological function of the failing organs as well as solving the problem of insufficient donor sources. However, the xenograft, suffered from immune rejection and ischemia-reperfusion injury (IRI), causes massive reactive oxygen species (ROS) expression and the subsequent cell apoptosis, leading to the xenograft failure. Our previous study found a positive role of PPAR-γ in anti-inflammation through its immunomodulation effects, which inspires us to apply PPAR-γ agonist rosiglitazone (RSG) to address survival issue of xenograft with the potential to eliminate the excessive ROS. In this study, xenogenic bioroot was constructed by wrapping the dental follicle cells (DFC) with porcine extracellular matrix (pECM). The hydrogen peroxide (H₂O₂)-induced DFC was pretreated with RSG to observe its protection on the damaged biological function. Immunoflourescence staining and transmission electron microscope were used to detect the intracellular ROS level. SD rat orthotopic transplantation model and superoxide dismutase 1 (SOD1) knockout mice subcutaneous transplantation model were applied to explore the regenerative outcome of the xenograft. It showed that RSG pretreatment significantly reduced the adverse effects of H₂O₂ on DFC with decreased intracellular ROS expression and alleviated mitochondrial damage. In vivo results confirmed RSG administration substantially enhanced the host's antioxidant capacity with reduced osteoclasts formation and increased periodontal ligament-like tissue regeneration efficiency, maximumly maintaining the xenograft function. We considered that RSG preconditioning could preserve the biological properties of the transplanted stem cells under oxidative stress (OS) microenvironment and promote organ regeneration by attenuating the inflammatory reaction and OS injury.
Mice ; Humans ; Rats ; Animals ; Swine ; PPAR gamma/pharmacology* ; Reactive Oxygen Species/pharmacology* ; Heterografts ; Hydrogen Peroxide/pharmacology* ; Rats, Sprague-Dawley ; Rosiglitazone/pharmacology* ; Oxidative Stress

OBJECTIVE: To explore the effect of rosiglitazone (ROS) on proliferation of human laryngeal carcinoma Hep-2 cells and it's mechanism. METHOD: Methabenzthiazuron (MTT) was used to observe the proliferation of human laryngeal carcinoma Hep-2 cells by various concentrations of ROS at different times. Flow cytometry (FCM) used to measure the cell cycle and apoptosis rate. RT-PCR was used to measure the expression of cyclooxygenase-2 (COX-2) mRNA. RESULT: The inhibited growth of ROS to Hep-2 cells in a dose-dependent and time-dependent manner (P < 0.01). The cell cycle was arrested in G0/G1 phase, which with a typical sub G1 peak, and the apoptosis rate increased in a time-dependent manner (P < 0.05). The expression of COX-2 mRNA in Hep-2 cells was significantly down-regulated by ROS (P < 0.01). CONCLUSION The function of growth inhibition and apoptosis induction of ROS on human laryngeal cancer Hep-2 cells was obvious, and its mechanism was related to block cell cycle at the G0/G1 phase and decrease the expression of COX-2.
Apoptosis ; drug effects ; Carcinoma, Squamous Cell ; metabolism ; Cell Cycle ; drug effects ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Cyclooxygenase 2 ; metabolism ; Humans ; Hypoglycemic Agents ; pharmacology ; Laryngeal Neoplasms ; metabolism ; Rosiglitazone ; Thiazolidinediones ; pharmacology

OBJECTIVE: To observe the effect of rosiglitazone on the production of nitric oxide (NO) and the expression of phosphatidylinositol 3-kinase (PI3K)/protein kinase B (PKB) /the endothelial nitric oxide synthase (eNOS) in cultured human umbilical vein endothelial cells(HUVECs), and to investigate the mechanism of signal transduction of rosiglitazone in improving the endothelial function. METHODS: HUVECs were treated with various concentrations of rosiglitazone. The NO level was measured using Griess Reaction in cell culture supernatants; the expressions of PI3K-, PKB- and eNOS mRNA were measured using RT-PCR; and the expressions of PKB, eNOS, and phosphorylation of PKB-Ser473, eNOS-Ser1177 were measured using Western Blot. RESULTS: Rosiglitazone increased the endothelial NO production in a dose- and time-dependent manner in cultured HUVECs, and also increased the expression of PI3K mRNA and the phosphorylation of PKB-Ser473 and eNOS-Ser1177 in a concentration-dependent manner, with no alteration in the expression of PKB and eNOS in cultured HUVECs. N(w)-nitro-L- arginine methyl ester (L-NAME, eNOS synthase inhibitor) blocked the rosiglitazone-induced NO formation; LY294002 (a PI3K inhibitor) prevented the NO production; and the phosphorylation of eNOS and PKB was induced by rosiglitazone. CONCLUSION Treatment with rosiglitazone can increase the NO production and improve the endothelial function through up-regulating the PI3K/PKB/eNOS signal pathways in cultured HUVECs.
Cells, Cultured ; Human Umbilical Vein Endothelial Cells ; drug effects ; metabolism ; Humans ; Nitric Oxide ; metabolism ; Nitric Oxide Synthase Type III ; metabolism ; Phosphatidylinositol 3-Kinases ; metabolism ; Phosphorylation ; drug effects ; Proto-Oncogene Proteins c-akt ; metabolism ; Rosiglitazone ; Signal Transduction ; drug effects ; Thiazolidinediones ; pharmacology

The present study was undertaken to evaluate the influence of the methanolic fruit extract of Momordica cymbalaria (MFMC) on PPARγ (Peroxisome Proliferator Activated Receptor gamma) and GLUT-4 (Glucose transporter-4) with respect to glucose transport. Various concentrations of MFMC ranging from 62.5 to 500 μg·mL(-1) were evaluated for glucose uptake activity in vitro using L6 myotubes, rosiglitazone was used as a reference standard. The MFMC showed significant and dose-dependent increase in glucose uptake at the tested concentrations, further, the glucose uptake activity of MFMC (500 μg·mL(-1)) was comparable with rosigilitazone. Furthermore, MFMC has shown up-regulation of GLUT-4 and PPARγ gene expressions in L6 myotubes. In addition, the MFMC when incubated along with cycloheximide (CHX), which is a protein synthesis inhibitor, has shown complete blockade of glucose uptake. This indicates that new protein synthesis is required for increased GLUT-4 translocation. In conclusion, these findings suggest that MFMC is enhancing the glucose uptake significantly and dose dependently through the enhanced expression of PPARγ and GLUT-4 in vitro.
Biological Transport ; Dose-Response Relationship, Drug ; Fruit ; Gene Expression ; drug effects ; Glucose ; metabolism ; Glucose Transporter Type 4 ; metabolism ; Hypoglycemic Agents ; pharmacology ; In Vitro Techniques ; Insulin ; metabolism ; Momordica ; Muscle Fibers, Skeletal ; drug effects ; PPAR gamma ; metabolism ; Plant Extracts ; pharmacology ; Protein Biosynthesis ; Protein Synthesis Inhibitors ; pharmacology ; Rosiglitazone ; Thiazolidinediones ; pharmacology ; Up-Regulation