Relationship between aging and renal high-affinity sodium-dependent dicarboxylate cotransporter-3 expression characterized with antifusion protein antibody.

Sodium-dependent dicarboxylate cotransporter (NaDC), which is responsible for the transportation of intermediates of the Krebs cycle, has been implicated in extending the life span of drosophila. In the present study, we cloned an intracellular domain segment of human kidney NaDC-3, which is 75% identical to that of the rat, constructed a polyclonal antibody against fusion protein of glutathione S-transferase (GST)-NaDC-3, and detected its renal expression changes with aging in both Wistar rats and normal humans. Western blot and immunohistochemistry confirmed the specificity of the antibody, and its location was found to be on the basolateral membrane of the renal proximal tubule. In addition, Western and Northern blots showed that NaDC-3 in kidneys significantly increased with age in Wistar rats. In healthy humans, renal NaDC-3 abundance also increased with age. Our results demonstrated that NaDC-3 expression was increased in aged Wistar rats and aged people, indicating that NaDC-3 may have a role in the process of kidney aging.