osteoblast

Introduction

Function:

• bone formation
• production of osteoid containing collagen type 1 & in much smaller quantities, osteocalcin & osteopontin, which compose the organic matrix of bone
• mineralization of osteoid matrix
• remodeling of bone in conjunction with osteoclasts
• osteoblasts trapped in the bone matrix become osteocytes

Formation:

• differentiation induced by bone morphogenic proteins
• other growth factors may be involved
  • FGF, PDGF, TGF-beta

Markers:

• osteoprogenitor cells express Cbfa1/Runx2
• osteoblasts express osterix, col1, ALP, osteocalcin, osteopontin, osteonectin

Regulation of osteoclasts by RANKL, cell surface & secreted

Morphology:

• cytoplasm is basophilic on H&E stain due to presence of large amounts of rough endoplasmic reticulum
• nucleus is large & spherical
• stain positively for collagen tyep 1 of alkaline phosphatase

More general terms

• osteocyte