ABSTRACT
BACKGROUND: Although some glycolytic intermediates have been shown to modulate several cell type formation and activation, the functional role of fructose 1,6-bisphosphate (FBP) on osteoclastogenesis is still unknown. METHODS: Osteoclastogenesis was evaluated on bone marrow preosteoclasts cultured with M-CSF - 30 ng/ml, RANKL - 10 ng/ml, and two concentrations of FBP (100 and 300 µM). TRAP-positive stained cells were counted, and osteoclastogenic marker genes expression were evaluated by qPCR. Osteoclasts resorption capacity was evaluated by the expression of specific enzymes and capacity to resorb a mineralized matrix. The NF-κB activation was detected using RAW 264.7, stably expressing luciferase on the NF-κB responsive promoter. RESULTS: We show that FBP, the product of the first stage of glycolysis, inhibited RANKL-induced osteoclasts differentiation and TRAP activity. The treatment of preosteoclasts with FBP attenuated osteoclast fusion and formation, without affecting cell viability. Moreover, the inhibition of several osteoclastogenic marker genes expression (TRAP, OSCAR, DC-STAMP, Integrin αv, NFATc1) by FBP correlates with a reduction of mineralized matrix resorption capacity. The mechanism underlying FBP-inhibition of osteoclastogenesis involves NF-κB/NFATc1 signaling pathway inhibition. CONCLUSION: Altogether these data show a protective role of a natural glycolytic intermediate in bone homeostasis that may have therapeutic benefit for osteolytic diseases.
Subject(s)
Fructosediphosphates/pharmacology , NF-kappa B/metabolism , NFATC Transcription Factors/genetics , Osteoclasts/drug effects , Osteogenesis/drug effects , RANK Ligand/pharmacology , Animals , Bone Marrow Cells/cytology , Bone Marrow Cells/drug effects , Cell Differentiation/drug effects , Cells, Cultured , Femur/cytology , Male , Mice, Inbred C57BL , Osteoclasts/cytology , Tibia/cytologyABSTRACT
Four young male subjects (age range, 17 4/12 to 25 5/12 years), previously treated with human growth hormone for non-growth hormone-dependent short stature, showed reduced testicular volume and hypergonadotropic hypogonadism. They also showed impaired spermatogenesis and altered testicular texture as determined by ultrasonography. No clinical or laboratory finding showed disease associated with testicular dysfunction. An unfavorable gonadal outcome could occur in boys without growth hormone deficiency treated with human growth hormone.