BMP7 (Bone morphogenetic protein 7) is a TGF-Beta family protein expressed in the bladder, kidneys and brain that directs osteoblast differentiation, bone homeostasis and mesenchymal cell transformation into cartilage and bone. It is important for embryogenesis, neurogenesis, tissue development and tissue organization. Recombinant BMP7 is used as a treatment in cases of osteoporotic vertebral fractures and for nonunions of long bone fractures. Separately, BMP7 is important for the development and proper differentiation of noradrenergic and catecholamine neurons, and it may be suppressed in cases of major depression. Lowered levels of BMP7 in brainstem astrocytes have been reported, and this may play a role in the disrupted noradrenergic signaling found in major depressive disorders. Furthermore, induced upregulation could potentially function as an antidepressant. In immunohistochemistry, BMP7 has extracellular and secretory positivity in the brain, thyroid, bladder, kidney, esophagus (with lower levels of expression throughout the gastrointestinal tract), reproductive tissues and the skin. References: Growth Factors. 22 (4): 233–41, PMID: 15621726; Spine J. 2006 Sep-Oct;6(5):500-6, PMID: 16934718; Bone Joint J. 2015 Jul;97-B(7):997-1003; PLoS One. 2012;7(3):e34088, PMID: 22461901; International Journal of Neuropsychopharmacology. 2011. 2012 (15): 855–868, DOI: 10.1017/S1461145711001350