For differentiation of BMNCs into osteoclasts
, BMNCs were cultured for 7 days in medium containing macrophage colony-stimulating factor (M-CSF; 10 ng/ml), RANKL (50 ng/ml) (Reprotech; Rocky Hill, NJ, USA), and LPNS (0, 50, 100 or 200 mg/l).
The key signalling protein for osteoclast
differentiation is RANKL, which attaches to a receptor that is widely expressed on osteoclasts
In addition, the proteins needed for the differentiation of the macrophages into osteoclasts
will be incorporated in these NPs.
Osteoblasts not only play a central role in bone formation by synthesizing several bone matrix proteins, but regulate osteoclast
maturation through expression of soluble factors RANKL and M-CSF, resulting in bone resorption.
All peptides appeared to have an impact on osteoclasts
mediating bone resorption.
They discovered that human smokers produce unusually large amounts of two proteins that foster production of bone-resorbing osteoclasts
compared to non-smokers.
Osteblasts and osteoclasts
are not the only cellular elements contributing to the bone turnover process.
Bone resorption by osteoclasts
involves the breakdown of both the mineral and organic bone matrix of bone, the latter mainly involving type I collagen.
The bisphosphonates, which are non-metabolized synthetic analogs of pyrophosphate synthetase, function through their inhibition of osseous resorption via suppression of osteoclast
Osteopetrosis is caused by a defect in osteoclast
OPG binds to RANKL and neutralizes it, blocking the differentiation and activation of new osteoclasts
and shortening the survival time of existing osteoclasts
In the in vitro study, a mixed culture of osteoblasts and osteoclasts
was used to represent the composition of a normal bone and levels of alkaline phosphatase (ALP), a marker of osteoblast activity, were measured.