stem cell therapy is a powerful technique for the treatment of a number of diseases. stem cells are derived from different tissue sources, the most important of which are the bone marrow (bm), umbilical cord (uc) blood and liver. human uc mesenchymal stem cells (huc-mscs) are multipotent, non-hematopoietic stem cells that have the ability to self-renew and differentiate into other cells and tis...

While mammals have a limited capacity to repair bone defects, zebrafish can completely regenerate amputated bony structures of their fins. Fin regeneration is dependent on formation of a blastema, a progenitor cell pool accumulating at the amputation plane. It is unclear which cells the blastema is derived from, whether it forms by dedifferentiation of mature cells, and whether blastema cells a...

Hematopoietic stem cell differentiation occurs in direct proximity to osteoblasts within the bone marrow cavity. Despite this striking affiliation, surprisingly little is known about the precise cellular and molecular impact of osteoblasts on the bone marrow microenvironment. Recently, we showed that human osteoblasts produce a variety of cytokine mRNAs including granulocyte colony-stimulating ...

Patients with HIV infection have decreased numbers of osteoblasts, decreased bone mineral density and increased risk of fracture compared to uninfected patients; however, the molecular mechanisms behind these associations remain unclear. We questioned whether Gp120, a component of the envelope protein of HIV capable of inducing apoptosis in many cell types, is able to induce cell death in bone-...

OssiMend® Bioactive (Collagen Matrix Inc., NJ) is a three-component porous composite bone graft device of 45S5 Bioglass/carbonate apatite/collagen. Our in vitro studies showed that conditioned media the dissolution products OssiMend stimulated primary human osteoblasts to form mineralized bone-like nodules one week, basal culture (no osteogenic supplements). Osteoblast differentiation was follo...

The ability of Brucella spp. to infect human osteoblasts and the cytokine response of these cells to infection were investigated in vitro. Brucella abortus, B. suis, B. melitensis, and B. canis were able to infect the SaOS-2 and MG-63 osteoblastic cell lines, and the first three species exhibited intracellular replication. B. abortus internalization was not significantly affected by pretreatmen...

We have studied the effect of insulin-like growth factor I (IGF-I) on the formation of osteocalcin and type I collagen in isolated human osteoblasts. IGF-I at and above 0.1 nM stimulated the formation of type I collagen as measured by the type I procollagen carboxyterminal peptide (PICP), in human osteoblasts, incubated for 72 hrs in serum free conditions. The secretion of osteocalcin was not a...

Over-production of hydrogen peroxide (H2O2) will lead to human osteoblast dysfunction and apoptosis, causing progression of osteoporosis and osteonecrosis. NF-E2-related factor 2 (Nrf2) is a well-characterized anti-oxidant signaling. Cullin 3 (Cul3) ubiquitin E3 ligase dictates Nrf2 degradation. We demonstrate that microRNA-455 ("miR-455") is a putative Cul3-targeting microRNA. Forced-expressio...

Obesity and osteoarthritis (OA) form a vicious circle in which obesity contributes to cartilage destruction in OA, and OA-associated sedentary behaviour promotes weight gain. Lipocalin-2 (LCN2), a novel adipokine with catabolic activities in OA joints, contributes to the obesity and OA pathologies and is associated with other OA risk factors. LCN2 is highly induced in osteoblasts in the absence...