Saint Francis University

About: Saint Francis University is a education organization based out in Loretto, Pennsylvania, United States. It is known for research contribution in the topics: Population & Osteoblast. The organization has 1694 authors who have published 2038 publications receiving 87149 citations.

Growth Factors and Cytokines in Bone Cell Metabolism

Abstract: Growth factors regulate the growth and differentiated function of cells. Skeletal cells synthesize fibroblast growth factor, platelet-derived growth factor, insulin-like growth factor, transforming growth factor beta, and additional cytokines. Some of the growth factors produced by bone cells primarily stimulate bone cell replication, whereas others also affect the differentiated function of the osteoblast. Skeletal growth factors also may play a role in the pathogenesis and therapy of metabolic bone disease.

Notch 1 Impairs Osteoblastic Cell Differentiation

Abstract: Notch receptors are single pass transmembrane receptors activated by membrane-bound ligands with a role in cell proliferation and differentiation. As Notch 1 and 2 mRNAs are expressed by osteoblasts and induced by cortisol, we postulated that Notch could regulate osteoblastogenesis. We investigated the effects of retroviral vectors directing the constitutive expression of the Notch 1 intracellular domain (NotchIC) in murine ST-2 stromal and in MC3T3 cells. NotchIC overexpression was documented by increased Notch 1 transcripts and activity of the Notch-dependent Hairy Enhancer of Split promoter. In the presence of bone morphogenetic protein-2 (BMP-2), ST-2 cells differentiated toward osteoblasts forming mineralized nodules, and Notch 1 opposed this effect and decreased the expression of osteocalcin, type I collagen, and alkaline phosphatase transcripts and Δ2Δ FosB protein. Further, NotchIC decreased Wnt/β-catenin signaling. As cells differentiated in the presence of BMP-2, they underwent apoptosis, and No...

Interleukin-1 has independent effects on deoxyribonucleic acid and collagen synthesis in cultures of rat calvariae.

Abstract: Interleukin-1 (IL-1), a monokine known to be important in host defense mechanisms and recently reported to stimulate bone resorption, was studied for its effects on bone formation in cultures of 21-day-old fetal rat calvariae. IL-1 at 0.1–5 U/ml stimulated the incorporation of [3H] thymidine into acid-insoluble residues (DNA) by 29–123% in calvariae treated for 24–96 h. IL-1 also increased the bone DNA content and the number of mitoses after colcemid arrest. IL-1 stimulated total protein synthesis. Treatment with IL-1 at 0.01–1 U/ml for 24 h caused a small increase in the incorporation of [3H]proline into collagenase-digestible protein (CDP) and noncollagen protein (NCP). However, higher doses of IL-1 (5 U/ml) or longer exposure to the agent (1 U/ml for 96 h) inhibited the labeling of CDP but not of NCP. IL-1 affected only type I collagen. The stimulatory effects of IL-1 on DNA, CDP, and NCP labeling were independent, since they were observed at different doses, and hydroxyurea abolished the effect on DNA...