OBJECTIVE: Two kinds of single nucleotide polymorphism (SNP; Asn130Asp and Val174Ala) are frequently observed in the liver specific transporter, organic anion transporting polypeptide 1B1 (OATP1B1/OATP-C) gene. Although these two SNPs occur independently in European-Americans, Val174Ala is mostly associated with Asn130Asp in Japanese. Our previous in-vivo studies in Japanese subjects indicated that the non-renal clearance of pravastatin was decreased to 13% of that in wild-type subjects (Nishizato et al. Clin Pharmacol Ther 2003;73(6):554-564). The purpose of the present study is to characterize the function of SNPs variants of OATP1B1 in cDNA transfected cells. METHODS: The localization and transport activity were analyzed in HEK293 cells stably expressing wild-type OATP1B1 (OATP1B1*1a), OATP1B1*1b (Asn130Asp), OATP1B1*5 (Val174Ala) and OATP1B1*15 (Asn130Asp and Val174Ala). To characterize the intrinsic Vmax, observed Vmax in uptake study were normalized by the expression level estimated from Western blotting. RESULTS: All SNP variants are predominantly located on the cell surface. No significant alteration was observed in Km values for the transport of 17beta-estradiol 17beta-d-glucuronide (E217betaG), a typical substrate of OATP1B1, among these SNP variants. However, the normalized Vmax value for OATP1B1*15 was drastically decreased to less than 30% compared with OATP1B1*1a. In contrast, the transport activity of OATP1B1*1b (Asn130Asp) and OATP1B1*5 (Val 174Ala) was similar to that of OATP1B1*1a. CONCLUSIONS: These results are consistent with the results of our previous clinical studies. It is thus suggested that in-vivo disposition may be predicted from in-vitro results using recombinant transporters.
OBJECTIVE: Two kinds of single nucleotide polymorphism (SNP; Asn130Asp and Val174Ala) are frequently observed in the liver specific transporter, organic anion transporting polypeptide 1B1 (OATP1B1/OATP-C) gene. Although these two SNPs occur independently in European-Americans, Val174Ala is mostly associated with Asn130Asp in Japanese. Our previous in-vivo studies in Japanese subjects indicated that the non-renal clearance of pravastatin was decreased to 13% of that in wild-type subjects (Nishizato et al. Clin Pharmacol Ther 2003;73(6):554-564). The purpose of the present study is to characterize the function of SNPs variants of OATP1B1 in cDNA transfected cells. METHODS: The localization and transport activity were analyzed in HEK293 cells stably expressing wild-type OATP1B1 (OATP1B1*1a), OATP1B1*1b (Asn130Asp), OATP1B1*5 (Val174Ala) and OATP1B1*15 (Asn130Asp and Val174Ala). To characterize the intrinsic Vmax, observed Vmax in uptake study were normalized by the expression level estimated from Western blotting. RESULTS: All SNP variants are predominantly located on the cell surface. No significant alteration was observed in Km values for the transport of 17beta-estradiol 17beta-d-glucuronide (E217betaG), a typical substrate of OATP1B1, among these SNP variants. However, the normalized Vmax value for OATP1B1*15 was drastically decreased to less than 30% compared with OATP1B1*1a. In contrast, the transport activity of OATP1B1*1b (Asn130Asp) and OATP1B1*5 (Val 174Ala) was similar to that of OATP1B1*1a. CONCLUSIONS: These results are consistent with the results of our previous clinical studies. It is thus suggested that in-vivo disposition may be predicted from in-vitro results using recombinant transporters.
Authors: Laura B Ramsey; Gitte H Bruun; Wenjian Yang; Lisa R Treviño; Selina Vattathil; Paul Scheet; Cheng Cheng; Gary L Rosner; Kathleen M Giacomini; Yiping Fan; Alex Sparreboom; Torben S Mikkelsen; Thomas J Corydon; Ching-Hon Pui; William E Evans; Mary V Relling Journal: Genome Res Date: 2011-12-06 Impact factor: 9.043
Authors: Paulo Caleb Junior Lima Santos; Ana Carolina Moron Gagliardi; Márcio Hiroshi Miname; Ana Paula Chacra; Raul Dias Santos; Jose Eduardo Krieger; Alexandre Costa Pereira Journal: Eur J Clin Pharmacol Date: 2011-09-18 Impact factor: 2.953
Authors: Tristan M Sissung; Caitlin E Baum; C Tyler Kirkland; Rui Gao; Erin R Gardner; William D Figg Journal: Mol Biotechnol Date: 2010-02 Impact factor: 2.695