Functional TauT protects against acute kidney injury.
Nephrotoxicity is common with the use of the chemotherapeutic agent cisplatin, but the cellular mechanisms that modulate the extent of injury are unknown. Cisplatin downregulates expression of the taurine transporter gene (TauT) in LLC-PK1 proximal tubular renal cells, and forced overexpression of TauT protects against cisplatin-induced apoptosis in vitro. Because the S3 segments of proximal tubules are the sites of both cisplatin-induced injury and adaptive regulation of the taurine transporter, we hypothesized that TauT functions as an anti-apoptotic gene and protects renal cells from cisplatin-induced nephrotoxicity in vivo. Here, we studied the regulation of TauT in cisplatin nephrotoxicity in a human embryonic kidney cell line and in LLC-PK1 cells, as well as in TauT transgenic mice. Cisplatin-induced activation of p53 repressed TauT and overexpression of TauT prevented the progression of cisplatin-induced apoptosis and renal dysfunction in TauT transgenic mice. Although cisplatin activated p53 and PUMA (a p53-responsive proapoptotic Bcl-2 family protein) in the kidneys of both wildtype and TauT transgenic mice, only wildtype animals demonstrated acute kidney injury. These data suggest that functional TauT plays a critical role in protecting against cisplatin-induced nephrotoxicity, possibly by attenuating a p53-dependent pathway.
Department of Pediatrics, University of Tennessee Health Science Center, 50 North Dunlap, Room 301 WPT, Memphis, TN 38103, USA. xhan@utmem.edu
Xiaobin
X
Han
Junming
J
Yue
Russell W
RW
Chesney
D058186:Acute Kidney Injury / Q000139:chemically induced / Q000378:metabolism*; D000818:Animals; D000970:Antineoplastic Agents / Q000633:toxicity*; D051017:Apoptosis Regulatory Proteins; D002460:Cell Line; D002945:Cisplatin / Q000633:toxicity*; D015536:Down-Regulation; D005786:Gene Expression Regulation; D006801:Humans; D007668:Kidney / Q000378:metabolism; D008297:Male; D008562:Membrane Glycoproteins / Q000378:metabolism*; D026901:Membrane Transport Proteins / Q000378:metabolism*; D051379:Mice; D008822:Mice, Transgenic; D013552:Swine; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism*; D025521:Tumor Suppressor Proteins / Q000378:metabolism; D000099247:Taurine Transporters
D000970:Antineoplastic Agents; D051017:Apoptosis Regulatory Proteins; D002945:Cisplatin; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins; D016159:Tumor Suppressor Protein p53; D025521:Tumor Suppressor Proteins; D000099247:Taurine Transporters; C488588:PUMA protein, mouse