Klotho expression in osteocytes regulates bone metabolism and controls bone formation

Regulation of Bone Metabolism

Bone is formed through the processes of endochondral and intramembranous ossification. In endochondral ossification primary mesenchymal cells differentiate to chondrocytes and then are progressively substituted by bone, while in intramembranous ossification mesenchymal stem cells (MSCs) differentiate directly into osteoblasts to form bone. The steps of osteogenic proliferation, differentiation,...

Physiology of Bone Formation, Remodeling, and Metabolism

Bone is a highly specialized supporting framework of the body, characterized by its rigidity, hardness, and power of regeneration and repair. It protects the vital organs, provides an environment for marrow (both blood forming and fat storage), acts as a mineral reservoir for calcium homeostasis and a reservoir of growth factors and cytokines, and also takes part in acid–base balance (Taichman ...

Life history of osteocytes: relationship to bone age, bone remodeling, and bone fragility.

Calcineurin regulates bone formation by the osteoblast.

Two of the most commonly used immunosuppressants, cyclosporine A and tacrolimus (FK506), inhibit the activity of a ubiquitously expressed Ca(2+)/calmodulin-sensitive phosphatase, calcineurin. Because both drugs also cause profound bone loss in humans and in animal models, we explored whether calcineurin played a role in regulating skeletal remodeling. We found that osteoblasts contained mRNA an...

Osteocytes: a proposed multifunctional bone cell.

Most cell types are ascribed a single function. The osteoclast holds the unique distinction of performing only one function in the body - that of resorbing bone. The osteoblast has been ascribed the major function of bone matrix production. Other less well-defined cell types include progenitor cells and the nebulous cell type that can support osteoclast formation upon stimulation with various b...