Objective: To study expression of CD44 S and CD44 V6 in ameloblastoma (AB) and odontogenic keratocyst (OKC) . Methods: S-P method was used to detect CD44 S protein in 77 cases of AB (32 of primary, 39 of recurrent,6 of malignant), 19 cases of OKC and 12 cases of oral normal mucosa;and CD44 V6 protein in 61 cases of AB (24 of primary , 31 of recurrent and 6 of malignant), 19 cases of OKC and 12 cases of oral normal mucosa. Results: Expression of CD44 S and CD44 V6 were detected in cell membrane of stratum spinosum and stratum basale in normal oral mucosa. In 19 cases of OKC, loss of expression of CD44 S was detected in 10 cases, and loss of integrity of CD44 V6 expression was detected in 15 cases. Loss ration of expression and abnormal expression ratio of CD44 S in AB were 27.3% and 63.6%, respectively. That of CD44 V6 in AB were 11.5% and 50.8% respectively. There was a signifcant difference between loss of expression or abnormal expression of CD44 S and CD44 V6 in AB, OKC and normal oral mucosa (P

OBJECTIVE: To investigate the effect of periostin on hypoxia-induced oxidative stress and apoptosis in human periodontal ligament fibroblasts and the molecular mechanism involved. METHODS: cultured human periodontal ligament fibroblasts were placed in an anaerobic gas-producing bag for hypoxia treatment for 48 h followed by treatment with periostin at low (25 ng/mL), moderate (50 ng/mL) or high (100 ng/mL) doses. MTT assay was used to measure the cell viability, and the cell apoptosis rate was determined using flow cytometry. The contents of IL-1β, IL-6 and TNF-α in the cells were determined with ELISA, and ROS levels were measured using a fluorescent plate reader. The intracellular SOD activity was detected using ELISA. The expressions of HIF-1α, P21, cyclin D1, Bax, cleaved caspase-3, Bcl-2, P38MAPK and p-p38 MAPK proteins in the cells were detected with Western blotting. RESULTS: Hypoxia treatment significantly reduced the cell viability ( < 0.05), increased P21, Bax, and cleaved caspase-3 protein levels ( < 0.05), promoted cell apoptosis ( < 0.05), and decreased cyclin D1 and Bcl-2 protein levels ( < 0.05) in the cells. Compared with the hypoxic group, the cells treated with periostin at different concentrations showed significantly increased cell viability ( < 0.05) with significantly lowered apoptotic rates ( < 0.05) and decreased expression levels of Bax and cleaved caspase-3 ( < 0.05) but significantly increased expression levels of cyclin D1 and Bcl-2 ( < 0.05). Hypoxic exposure of the cells resulted in significantly increased expression levels of HIF-1α and p-p38 MAPK ( < 0.05) and increased levels of IL-1β, IL-6, TNF-α and ROS ( < 0.05) but decreased SOD activity ( < 0.05). Periostin treatment at different concentrations significantly lowered the expression levels of HIF-1α and p-p38 MAPK ( < 0.05) and the levels of IL-1β, IL-6, TNF-α and ROS ( < 0.05) and significantly increased SOD activity in the hypoxic cells ( < 0.05). CONCLUSIONS Periostin promotes the proliferation, inhibits apoptosis, enhances cellular antioxidant capacity, and reduces inflammatory damage in human periodontal ligament fibroblasts exposed to hypoxia possibly by inhibiting the activation of the p38 MAPK signaling pathway.
Apoptosis ; Fibroblasts ; Humans ; Hypoxia ; Oxidative Stress ; Periodontal Ligament ; Signal Transduction ; p38 Mitogen-Activated Protein Kinases

OBJECTIVE: To investigate the effect of periostin on hypoxia-induced oxidative stress and apoptosis in human periodontal ligament fibroblasts and the molecular mechanism involved. METHODS: cultured human periodontal ligament fibroblasts were placed in an anaerobic gas-producing bag for hypoxia treatment for 48 h followed by treatment with periostin at low (25 ng/mL), moderate (50 ng/mL) or high (100 ng/mL) doses. MTT assay was used to measure the cell viability, and the cell apoptosis rate was determined using flow cytometry. The contents of IL-1β, IL-6 and TNF-α in the cells were determined with ELISA, and ROS levels were measured using a fluorescent plate reader. The intracellular SOD activity was detected using ELISA. The expressions of HIF-1α, P21, cyclin D1, Bax, cleaved caspase-3, Bcl-2, P38MAPK and p-p38 MAPK proteins in the cells were detected with Western blotting. RESULTS: Hypoxia treatment significantly reduced the cell viability ( < 0.05), increased P21, Bax, and cleaved caspase-3 protein levels ( < 0.05), promoted cell apoptosis ( < 0.05), and decreased cyclin D1 and Bcl-2 protein levels ( < 0.05) in the cells. Compared with the hypoxic group, the cells treated with periostin at different concentrations showed significantly increased cell viability ( < 0.05) with significantly lowered apoptotic rates ( < 0.05) and decreased expression levels of Bax and cleaved caspase-3 ( < 0.05) but significantly increased expression levels of cyclin D1 and Bcl-2 ( < 0.05). Hypoxic exposure of the cells resulted in significantly increased expression levels of HIF-1α and p-p38 MAPK ( < 0.05) and increased levels of IL-1β, IL-6, TNF-α and ROS ( < 0.05) but decreased SOD activity ( < 0.05). Periostin treatment at different concentrations significantly lowered the expression levels of HIF-1α and p-p38 MAPK ( < 0.05) and the levels of IL-1β, IL-6, TNF-α and ROS ( < 0.05) and significantly increased SOD activity in the hypoxic cells ( < 0.05). CONCLUSIONS Periostin promotes the proliferation, inhibits apoptosis, enhances cellular antioxidant capacity, and reduces inflammatory damage in human periodontal ligament fibroblasts exposed to hypoxia possibly by inhibiting the activation of the p38 MAPK signaling pathway.
Apoptosis ; drug effects ; Cell Adhesion Molecules ; administration & dosage ; Cell Hypoxia ; Fibroblasts ; drug effects ; Humans ; Oxidative Stress ; drug effects ; Periodontal Ligament ; cytology ; Signal Transduction ; drug effects ; p38 Mitogen-Activated Protein Kinases

It is not fully clear why there is a higher contribution of pluripotent stem cells (PSCs) to the chimera produced by injection of PSCs into 4-cell or 8-cell stage embryos compared with blastocyst injection. Here, we show that not only embryonic stem cells (ESCs) but also induced pluripotent stem cells (iPSCs) can generate F0 nearly 100% donor cell-derived mice by 4-cell stage embryo injection, and the approach has a "dose effect". Through an analysis of the PSC-secreted proteins, Activin A was found to impede epiblast (EPI) lineage development while promoting trophectoderm (TE) differentiation, resulting in replacement of the EPI lineage of host embryos with PSCs. Interestingly, the injection of ESCs into blastocysts cultured with Activin A (cultured from 4-cell stage to early blastocyst at E3.5) could increase the contribution of ESCs to the chimera. The results indicated that PSCs secrete protein Activin A to improve their EPI competency after injection into recipient embryos through influencing the development of mouse early embryos. This result is useful for optimizing the chimera production system and for a deep understanding of PSCs effects on early embryo development.
Activins ; metabolism ; Animals ; Cells, Cultured ; Embryonic Development ; Germ Layers ; metabolism ; Mice ; Pluripotent Stem Cells ; cytology ; metabolism