| First Author | Mieczkowska A | Year | 2013 |
| Journal | Bone | Volume | 56 |
| Issue | 2 | Pages | 337-42 |
| PubMed ID | 23851294 | Mgi Jnum | J:203708 |
| Mgi Id | MGI:5528580 | Doi | 10.1016/j.bone.2013.07.003 |
| Citation | Mieczkowska A, et al. (2013) Glucose-dependent insulinotropic polypeptide (GIP) receptor deletion leads to reduced bone strength and quality. Bone 56(2):337-42 |
| abstractText | Bone is permanently remodeled by a complex network of local, hormonal and neuronal factors that affect osteoclast and osteoblast biology. In this context, a role for gastro-intestinal hormones has been proposed based on evidence that bone resorption dramatically falls after a meal. Glucose-dependent insulinotropic polypeptide (GIP) is one of the candidate hormones as its receptor, glucose-dependent insulinotropic polypeptide receptor (GIPR), is expressed in bone. In the present study we investigated bone strength and quality by three-point bending, quantitative x-ray microradiography, microCT, qBEI and FTIR in a GIPR knockout (GIPR KO) mouse model and compared with control wild-type (WT) animals. Animals with a deletion of the GIPR presented with a significant reduction in ultimate load (--11%), stiffness (-16%), total absorbed (-28%) and post-yield energies (-27%) as compared with WT animals. Furthermore, despite no change in bone outer diameter, the bone marrow diameter was significantly increased and as a result cortical thickness was significantly decreased by 20% in GIPR deficient animals. Bone resorption at the endosteal surface was significantly increased whilst bone formation was unchanged in GIPR deficient animals. Deficient animals also presented with a pronounced reduction in the degree of mineralization of bone matrix. Furthermore, the amount of mature cross-links of collagen matrix was significantly reduced in GIPR deficient animals and was associated with lowered intrinsic material properties. Taken together, these data support a positive effect of the GIPR on bone strength and quality. |
