Parathyroid hormone-related protein (1-37) induces cAMP response in human osteoblast-like cells

During recent years parathyroid hormone-related protein (PTHrP) research has been focused on the physiological functions of different fragments of the PTHrP molecule. Here we demonstrate that PTHrP (1-37) induced cyclic adenosine monophosphate (cAMP) response in primary human osteoblast-like cells, which were well characterized by the presence of Alkaline Phosphatase activity and osteocalcin production after stimulation with 1,25-dihydroxyvitamin D3. However, there was no cAMP response to PTHrP (58-77). Furthermore, the response to PTHrP (1-37) was dose dependent, with a significant increase at 1 nM. The presence of PTHrP (1-37)-induced cAMP response in human osteoblast-like cells implies that aminoterminal PTHrP fragments may exert important functions in the bone.