cosa e’ il metabolismo osseo?web.mit.edu/asabatin/www/med/smc1/20141020-brandi...oct 20, 2014  ·...

Cosa E’ Il Metabolismo

Osseo?

SISTEMA DI OMEOSTASI DEL RICAMBIO CALCICO

INTESTINO OSSO1000 Gm1.0 Gm

0.36

1

0.19

1.0 Gm

LEC

0.170 Gm

2

3

ESCREZIONE URINARIA

0.83 Gm

RIASSORBIMENTO OSSEO

Gli Osteoclasti

LA FORMAZIONE OSSEA

Gli Osteoblasti

Mechanisms of osteoclastogenesis

and osteoclastic bone resorption

/

OSTEOCYTES AS MULTIFUNCTIONAL CELLS

Osteocyte Conversion of Mechanical Strain into Biochemical Signals

Osteocyte Modification of Their Microenvironment

Osteocytes as Regulators of Mineralization and Phosphate and

Calcium Homeostasis

Osteocyte Can Move

Functional syncytium comprising osteocytes, osteoblasts, bone

marrow stromal cells, and endothelial cells

Adapted from:JCI 104:1363, 1999

Mechanical strains Hormonal signals

Osteocytes Osteoblasts

Bone marrow

cellsEndothelial

cells

SOST and Wnt

SOST is a homolog of WISE, which binds to LRP-6. SOST binds to LRP-5 which is a co-

receptor in the Wnt-signalling pathway. Thus, SOST inhibits Wnt-signalling pathway,

similar to Dkk inhibition.

La Mineralizzazione