TNF-α mediates obstruction-induced renal tubular cell apoptosis and proapoptotic signaling

• Published in: American journal of physiology. Renal physiology 2005-02, Vol.57 (2), p.F406-F411
• Main Authors: MISSERI, R, MELDRUM, D. R, DINARELLO, C. A, DAGHER, P, HILE, K. L, RINK, R. C, MELDRUM, K. K
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; Cells; Fundamental and applied biological sciences. Psychology; Kidneys; Proteins; Vertebrates: urinary system
• ISSN: 1931-857X; 1522-1466

Obstruction of the upper urinary tract induces a progressive loss in renal mass through apoptotic renal cell death. Although TNF-alpha has been implicated in ischemia-reperfusion-induced apoptotic renal cell death, its role in obstructive renal cell apoptosis remains unknown. To study this, male Sprague-Dawley rats were subjected to left unilateral ureteral obstruction vs. sham operation. Twenty-four hours before surgery and every 84 h thereafter, rats received either vehicle or a pegylated form of soluble TNF receptor type 1 (PEG-sTNFR1). The kidneys were harvested 1, 3, or 7 days postoperatively, and tissue samples were subsequently analyzed for TNF-alpha (ELISA, RT-PCR), Fas ligand (RT-PCR), apoptosis (TUNEL, ELISA), and caspase 8 and 3 activity (Western blot). Renal obstruction induced increased tissue TNF-alpha and Fas ligand mRNA levels, TNF-alpha protein production, apoptotic renal tubular cell death, and elevated caspase 8 and 3 activity, whereas treatment with PEG-sTNFR1 significantly reduced obstruction-induced TNF-alpha production, renal tubular cell apoptosis, and caspase activity. PEG-sTNFR1 did not significantly alter Fas ligand expression. These results demonstrate that TNF-alpha mediates obstruction-induced renal tubular cell apoptosis and proapoptotic signaling and identify TNF-alpha neutralization as a potential therapeutic option for the amelioration of obstruction-induced renal injury. [PUBLICATION ABSTRACT]