Abstract for presentation at Australia and New Zealand Society of Nephrology Annual Scientific Conference

Purpose: The aim of this study was to assess whether proximal tubular cells (PTCs) from DM patients were more likely to acquire a myofibroblastic phenotype than of patients without diabetes (NDM).
Methods: Primary cultures of PTCs were cultured from 4 DM and 5 NDM patients. Cells were exposed to 10 ng/ml transforming growth factor beta (TGFβ) for 48 hrs and markers of EMT assessed.
Results: The basal levels of E-cadherin (epithelial marker) and vimentin (mesenchymal marker) were similar in PTCs from DM and NDM patients. Treatment with TGFβ showed a significant and similar loss of E-cadherin protein expression in both DM and NDM patients (23%+2.9 vs 18%+7.2; both P< 0,05 vs control). In parallel, similar increases in MMP-2 and -9 expression were observed in both patient groups. Increased protein expression of vimentin was observed in both groups but was greater in cells derived from patients with DM compared to NDM (41%+9.8 vs 25%+2.4 respectively; P<0.05). FACS analysis demonstrated a more pronounced increase of alpha smooth muscle actin in patients with DM compared to NDM (14+1.4% vs 4+0.3%; P<0.05). However, a similar increase in fibroblast antigen expression of 11.3%+ 1.0 vs 10.78%+0.9 was observed cells from both patient groups.
Conclusion: PTCs derived from DM and NDM patients exposed to a profibrogenic stimulus demonstrated a similar propensity to upregulate MMPs and lose markers of an epithelial phenotype. However, PTCs derived from patients with DM were more likely to gain fibroblastic characteristics compared to PTCs from NDM patients.