Bone from Healthy Individuals and Patients with CKD Expresses the Sodium-Glucose Co-transporter-2 (SGLT2)

Sodium-glucose co-transporter 2 (SGLT2) inhibitors are used in type 2 diabetes mellitus management, reducing the risk of cardiovascular and renal complications. It has been stated that bone cells do not express the SGLT2 co-transporter; however, the establishment of a direct SGLT2 expression in bone and osteoblast-like cells would provide a significant advance in our understanding of direct SGLT2i effects on bone tissue from patients with metabolic bone diseases, such as chronic kidney disease or osteoporosis. SLC5A2 gene expression was investigated in osteoblast-like and renal HK-2 cells, and in human iliac crest bone samples from healthy individuals and patients with diverse stages of CKD from total RNA by real-time PCR. Additionally, SGLT2 protein qualitative expression was evaluated by Western blot in osteoblast-like cell lysates and by immunohistochemistry in bone samples from apparently healthy individuals and patients with CKD. Statistical significance was set at p < 0.05. SLC5A2 gene expression in osteoblast-like cells is comparable to HK-2 cells. Notably, in human bone samples, SLC5A2 was detected above threshold in both healthy individuals and patients with CKD; thus, absolute quantification of its transcript number of copies was feasible in bone samples for these conditions. SGLT2 protein was detected in osteoblast-like cells. Additionally, this protein was immunodetected in osteocytes embedded in mineralized trabecular and cortical bone samples from healthy subjects and patients with CKD. SLC5A2 gene expression and SGLT2 protein were detected in human osteoblast-like cells and bone from both healthy individuals and patients with CKD. These findings constitute an essential step toward advancing the understanding of effects, if any, of SGLT2 inhibitors on bone tissue from patients with CKD.