[Summary]
 A research group led by Professor Abe Takaaki at Graduate School of Medical Sciences, Tohoku University and Professor Tomoyoshi Soga at Institute for Advanced Biosciences, Keio University (Director General Masao Tomita, Tsuruoka, Yamagata pref.) has discovered OATP-R in kidney, a novel target protein for chronic kidney disease (CKD) patients. So far, the fundamental therapy for CKD has not been established. Although OATP-R helps pump out uremic toxins accumulated in the body, this function is reduced in the renal failure. The research group has found that statin for the treatment of hyperlipidemia promotes OATP-R function, reducing uremic toxins followed by organ damages improvement. Their research results in helping development of a new treatment to reduce the progression of renal failure, and to delay initiation of dialysis.

 The research has been conducted with the aid of Collaborative Development of Innovative Seeds by Japan Science and Technology.

[Detail]
 The number of patients with renal failure and those who receive dialysis has been increasing, and more than 30,000 people initiate dialysis every year. Recently, 10 percent of the adult population possibly suffers from CKD. A vicious circle where uremic toxins accumulate because of deterioration in renal function causes further damages to kidney is a critical issue. So, the establishment of a mechanism to eliminate uremic toxins is urgently required. Although many toxic substances have been reported, a precise mechanism of elimination has not been clarified.

 The research group has discovered OATP-R, a transporter protein gene that plays an important role for uremic toxin elimination in 2004. Because protein expression of OATP-R decreases in the renal failure, and drugs or uremic toxins are not eliminated.

 

 In this study, the group made rats which OATP-R expresses only in their kidney. After comprehensive metabolome analysis of rats in the presence of renal failure, it is cleared that rats with OATP-R have improved survival rate by promoting uremic toxin elimination, returning blood pressure to normal, improving renal inflammation and cardiomegaly.

 The research group started looking for drugs that enhances OATP-R expression in the kidney, and found that statin for the treatment of hyperlipidemia has the beneficial effect in the renal failure.

 

 The treatment of CKD is mainly for curing hypertension and returning uric protein to normal. Because the drugs for renal diseases such as steroid and immunesuppressive drug is not originally developed for kidney dieseases, and has a significant side-effect. On the other hand, Statin as already been in clinical use, and its side-effect is easy to detect and not lethal. The research group has produced a new treatment to target OATP-R transporter by utilizing the in-use treatment for kidney disease.

 The research results have been published on-line in Journal of American Society of Nephrology on October 29, 2009. The paper’s title is SLCO4C1 transporter eliminates uremic toxins preventing hypertension and renal inflammation.

 

[Contact]
Professor Abe Takaaki
Tohoku University Graduate School of Medical Sciences
Address: 1-1 Seiryo-cho Aoba-ku, Sendai, Miyagi, 980-8574, Japan
Tel: +81-22-717-7163, FAX: +81-22-717-7168
E-mail: takaabe@mail.tains.tohoku.ac.jp

 

Tomoyoshi Soga
Institute for Advanced Biosciences, Keio University,
Baba-cho 14-1, Tsuruoka City, Yamagata, Japan
Tel: +81-235-29-0800, Fax: +81-235-29-0809
E-mail: soga@sfc.keio.ac.jp

 

[Public Information]
Associate Professor Fuji Nagami
PR Office of Tohoku University Graduate School of Medicine/School of Medicine
Address: 2-1 Seiryo-cho Aoba-ku, Sendai, Miyagi, 980-8575, Japan
TEL: +81-22-717-7908, FAX: +81-22-717-8187
E-mail: f-nagami@mail.tains.tohoku.ac.jp