Hypertrophy and Loss of Podocytes in Diabetic Nephropathy

Objective The loss of podocytes has been reported to have a role in the onset and progression of diabetic nephropathy (DN). Although structural changes such as podocyte hypertrophy are considered to be associated with podocyte loss, the relationship has not been thoroughly investigated using human DN renal tissues. Methods The subjects were 17 patients with DN diagnosed histopathologically by renal biopsy. Immunostaining was performed with antibodies for Wilm's tumor 1 (WT1) and synaptopodin (SPD), which are markers of podocytes, to determine the number of podocytes and assess podocyte hypertrophy. Results The number of podocytes was decreased in DN patients compared with the controls. An inverse correlation was observed between the number of podocytes and both the urinary protein excretion and the extent of mesangial expansion. Podocyte hypertrophy was also more marked in DN patients compared with controls. Conclusion Based on these results, podocyte loss and hypertrophy were suggested to be involved in the development and progression of human DN.