Alkaline phosphatase

About: Alkaline phosphatase is a research topic. Over the lifetime, 20218 publications have been published within this topic receiving 540547 citations. The topic is also known as: Alkaline_phosphatase & IPR001952.

Alkaline phosphatase promotes radioprotection and accumulation of WR-1065 in V79-171 cells incubated in medium containing WR-2721.

Abstract: Addition of alkaline phosphatase and WR-2721 to culture medium containing V79-171 cells leads to production of WR-1065 and its disulphide forms in the medium, to cellular accumulation of WR-1065, and to radioprotection which correlates with cellular WR-1065 level.

Capacitively coupled electric fields accelerate proliferation of osteoblast-like primary cells and increase bone extracellular matrix formation in vitro.

Abstract: Over the last few years, electric and electromagnetic fields have gained more and more significance in the therapy of bone fracture healing and bone disease. Yet, the underlying mechanisms on a cellular and molecular level are not completely understood. In the present study we have investigated the effects of capacitively coupled, pulsed electric fields on cellular proliferation, alkaline phosphatase activity, and matrix protein synthesis of osteoblast-like primary cells in vitro. Cells were derived from bovine periosteum and electrically stimulated by saw-tooth pulses of 100 V external voltage and 16 Hz frequency. This corresponds to an electric field of 6 kV/m across the cell membranes as could be shown by computer simulation. Field application caused acceleration of cell culture development. A significant increase of proliferation concurrent with an enhancement of alkaline phosphatase activity was observed in sub-confluent cultures. Exposure of confluent osteoblast-like primary cells to electric fields resulted in enhanced synthesis and secretion of extracellular matrix-related proteins. These findings suggest that capacitively coupled electric fields accelerate bone cell proliferation and differentiation in vitro and enhance the synthesis of cells leading to promoted matrix formation and maturation.

Isolation of pluripotent stem cells from cultured porcine primordial germ cells.

Abstract: Embryonic germ (EG) cells are undifferentiated stem cells isolated from cultured primordial germ cells (PGC). To date, EG cells have been isolated only in the mouse. Murine EG cells share several characteristics with embryonic stem (ES) cells, including morphology, pluripotency, and the capacity for germline transmission. We report here the isolation of porcine EG cells. PGC collected from Day 24 or 25 porcine embryos were cultured on mitotically inactivated murine fibroblasts. Four EG cell lines were isolated from repeated subculture of porcine PGC. Porcine EG cells morphologically resembled murine ES cells and consistently expressed alkaline phosphatase activity. These cell lines maintained a normal diploid karyotype and survived after cryopreservation. Porcine EG cells were capable of differentiating into a wide range of cell types in culture, including endodermal, trophoblast-like, epithelial-like, fibroblast-like, and neuron-like cells. In suspension culture, porcine EG cells formed embryoid bodies. When injected into host blastocysts, the EG cells were able to differentiate and contribute to tissues of a chimeric piglet. Both in vitro and in vivo evidence demonstrates that the isolated EG cells were pluripotent. These cells are potentially useful for genetic manipulation in pigs.

Skeletal growth factor and other growth factors known to be present in bone matrix stimulate proliferation and protein synthesis in human bone cells.

Abstract: The purpose of the study was to investigate the effect of skeletal growth factor/insulinlike growth factor II and other growth factors known to be present in bone matrix on the proliferation and differentiation of human bone cells. Cells were isolated by collagenase digestion from femoral heads obtained during hip replacement operations. Cells were cultured in DMEM medium with 10% calf serum. Third to fifth passage cells were plated in multiwell plates and the medium changed to low serum (0.1%) for 2 days. The medium was changed to serum-free medium prior to addition of growth factors. Cell proliferation was measured by the incorporation of [3H]thymidine into DNA and by the percentage of cells that incorporate bromodeoxyuridine. Protein synthesis was measured by the incorporation of [3H]proline into trichloroacetic acid-precipitable material. Skeletal growth factor/insulinlike growth factor II and insulinlike growth factor I stimulated cell proliferation and protein synthesis in a dose-dependent manner. Alkaline phosphatase-specific activity was not increased by these factors. Transforming growth factor beta 1 did not affect cell proliferation but stimulated protein synthesis and increased the specific activity of alkaline phosphatase. Fibroblast growth factor did not affect any of the cell parameters. These studies suggest that skeletal growth factor/insulinlike growth factor II, insulinlike growth factor I, and transforming growth factor beta 1 may play a role in the local control of the proliferation and differentiation of human osteoblasts.