Objective: To explore the possible cell biological mechanisms of the difference in prognosis between the acute tubular necrosis (ATN) induced by Manchurian Dutchmanspipe (MD-ATN) and that by antibiotics (A-ATN), by means of comparing their renal tubular mesenchymal cell phenotype characteristics and extra-cellular stroma secretion.
Methods: The expression of proliferative cell nuclear antigen (PCNA), epithelial cell growth factor (EGF), alpha-smooth muscle actin (alpha-SMA), fibronectin (FN), collagen type III and IV, transforming growth factor beta 1 (TGF beta 1) and connective tissue growth factor in renal biopsy samples of patients with MD-ATN (4 patients) and A-ATN(5 patients) were compared with immunohistochemical SP method. The analysis of above-mentioned parameters on repairing of injury and development of fibrosis was stressed for the obvious difference in clinical prognosis between the two groups.
Results: (1) The PCNA positive rate of renal tubular epithelial cell (RTEC) and EGF expression in the MD-ATN group were significantly lower than those in the A-ATN group respectively (P < 0.01); (2) Renal tubular mesenchymal alpha-SMA level increased in both groups with no significant difference; (3) TGF beta 1 positive cell infiltration and obvious CTGF expression revealed in renal mesenchyma of both groups with insignificant difference; (4) FN, collagen III and IV levels were significantly higher in the MD-ATN group than that in the A-ATN group (P < 0.05).
Conclusion: (1) As compared with A-ATN group, the RTEC auto-repairing ability was lower in the DM-ATN group, lower expression of EGF might be one of the mechanisms of its poor repair; (2) High expression of alpha-SMA, TGF beta 1 and CTGF presented in all patients with ATN, but extra-cellular stromal deposit appeared only in the renal stroma of patients with MD-ATN, suggesting that its chronical trend might be related with the reducing of extra-cellular stromal degradation factor and/or endogenous anti-fibrosis factor.