Astragaloside IV prevents high glucose-induced podocyte apoptosis via downregulation of TRPC6.

Diabetic nephropathy (DN) is one of the most important causes of end‑stage renal disease. Astragaloside IV (AS-IV) is a saponin isolated from Astragalus membranaceus, which possesses various pharmacological activities. AS‑IV prevents podocyte apoptosis and ameliorates renal injury in DN; however, few studies have focused on its effects on ion channels. The transient receptor potential channel 6 (TRPC6) is an important Ca2+‑permeable ion channel in podocytes, which is involved in high glucose (HG)-induced podocyte apoptosis. The aim of the present study was to investigate whether AS‑IV prevented HG‑induced podocyte apoptosis via TRPC6. Cultured podocytes were pre‑treated with 10, 20 or 40 µM AS‑IV for 1 h prior to HG exposure for 24 h. Apoptosis, cell viability, expression of TRPC6, nuclear factor of activated T cells (NFAT2) and B‑cell lymphoma 2‑associated X protein (Bax), as well as the intracellular Ca2+ concentration were subsequently analyzed. The results indicated that HG induced podocyte apoptosis and upregulation of TRPC6, and increased intracellular Ca2+. Furthermore, enhanced NFAT2 and Bax expression was detected. Conversely, AS‑IV protected HG‑induced podocyte apoptosis, downregulated TRPC6 expression and suppressed intracellular Ca2+ in HG-stimulated podocytes. AS‑IV also suppressed NFAT2 and Bax expression. These results suggest that AS‑IV may prevent HG-induced podocyte apoptosis via downregulation of TRPC6, which is possibly mediated via the calcineurin/NFAT signaling pathway.