Osteoporosis is a lesser known complication of diabetes mellitus type I (DM1). Patients with DM1-associated osteoporosis experience increased fracture risk and delayed fracture healing, resulting from decreased bone formation while bone resorption remains unchanged. However little is known about the mechanism of the diabetic bone phenotype. Our lab has shown that the NO/cGMP/PKG II pathway is highly involved in osteoblast mechanotransduction and estrogen induced osteoblast proliferation and survival. We therefore hypothesized that defects in the NO/cGMP/PKG II signaling may contribute to the pathology of diabetes associated osteoporosis. Multiple points within the signaling pathway were assessed with osteoblasts isolated from control and streptozotocin (STZ) induced DM1 mice to elucidate alterations due to diabetes. Immunoprecipitation of eNOS showed decreased eNOS-Hsp90[alpha] association, suggesting lower eNOS activity confirmed by reduced NO production in diabetic osteoblasts. Cytosolic PKG I levels were unaltered and membrane-bound PKG II showed decreased expression in diabetic osteoblasts. Further defective Erk/Akt signaling and reduced sensitivity to the NO donor, PAPA NONOate was also observed under hyperglycemic conditions. We also explored if cGMP-elevating agent cinaciguat was effective in enhancing PKG activity and the downstream signaling. Treatment of diabetic osteoblasts with cinaciguat showed increased VASP phosphorylation, Erk/Akt activation and fos family gene expression. Further, bromodeoxyuridine (BrDU) labeling of diabetic osteoblasts treated with cinaciguat effectively increased osteoblast proliferation. In this project, we found that the NO/cGMP/PKG signaling is impaired in diabetic osteoblasts and cinaciguat may be effective in treating osteoporosis in patients with type 1 diabetes