Promoter polymorphism of the erythropoietin gene in severe diabetic eye and kidney complications

doi:10.1073/pnas.0800454105

Promoter polymorphism of the erythropoietin gene in severe diabetic eye and kidney complications

Zongzhong Tong^a,^b,
Zhenglin Yang^c,^d,
Shrena Patel^a,^b,^e,
Haoyu Chen^a,^b,
Daniel Gibbs^a,^b,
Xian Yang^a,^b,
Vincent S. Hau^a,
Yuuki Kaminoh^a,^b,
Jennifer Harmon^a,^b,
Erik Pearson^a,^b,
Jeanette Buehler^a,^b,
Yuhong Chen^a,^b,
Baifeng Yu^a,^b,
Nicholas H. Tinkham^a,^b,
Norman A. Zabriskie^a,
Jiexi Zeng^a,^b,
Ling Luo^a,^b,
Jennifer K. Sun^f,
Manvi Prakash^f,
Rola N. Hamam^f,
Stephen Tonna^g,
Ryan Constantine^a,^b,
Cecinio C. Ronquillo^a,^b,
SriniVas Sadda^h,
Robert L. Averyⁱ,
John M. Brand^j,
Nyall London^b,
Alfred L. Anduze^k,
George L. King^l,
Paul S. Bernstein^a,
Scott Watkins^m,
Genetics of Diabetes and Diabetic Complication Study Groupⁿ,
Lynn B. Jorde^m,
Dean Y. Li^b,^d,
Lloyd Paul Aiello^f,
Martin R. Pollak^g, and
Kang Zhang^a,^b,^d,^j

^aDepartment of Ophthalmology and Visual Sciences,
^bProgram in Human Molecular Biology and Genetics, Eccles Institute of Human Genetics,
^eDivision of Neonatology, and
^mDepartment of Human Genetics, University of Utah School of Medicine, Salt Lake City, UT 84132;
^cSichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Sichuan 610072, China;
^fBeetham Eye Institute, Joslin Diabetes Center, and Department of Ophthalmology, Harvard Medical School, Boston, MA 02215;
^gDepartment of Medicine, Brigham and Women's Hospital, and Harvard Medical School, Boston, MA 02115;
^hDepartment of Ophthalmology, Doheny Eye Institute, Keck School of Medicine of the University of Southern California, Los Angeles, CA 90033;
ⁱCalifornia Retina Consultants and Research Foundation, Santa Barbara, CA 93103;
^jSalt Lake City Veterans Affairs Medical Center, 500 Foothill Drive, Salt Lake City, UT 84148;
^kIsland Medical Center, Christiansted, Saint Croix, VI 00823; and
^lJoslin Diabetes Center and Department of Medicine, Harvard Medical School, Boston, MA 02215

Edited by Helen H. Hobbs, University of Texas Southwestern Medical Center, Dallas, TX, and approved March 21, 2008 (received for review January 16, 2008)

Abstract

Significant morbidity and mortality among patients with diabetes mellitus result largely from a greatly increased incidence of microvascular complications. Proliferative diabetic retinopathy (PDR) and end stage renal disease (ESRD) are two of the most common and severe microvascular complications of diabetes. A high concordance exists in the development of PDR and ESRD in diabetic patients, as well as strong familial aggregation of these complications, suggesting a common underlying genetic mechanism. However, the precise gene(s) and genetic variant(s) involved remain largely unknown. Erythropoietin (EPO) is a potent angiogenic factor observed in the diabetic human and mouse eye. By a combination of case–control association and functional studies, we demonstrate that the T allele of SNP rs1617640 in the promoter of the EPO gene is significantly associated with PDR and ESRD in three European-American cohorts [Utah: P = 1.91 × 10⁻³; Genetics of Kidneys in Diabetes (GoKinD) Study: P = 2.66 × 10⁻⁸; and Boston: P = 2.1 × 10⁻²]. The EPO concentration in human vitreous body was 7.5-fold higher in normal subjects with the TT risk genotype than in those with the GG genotype. Computational analysis suggests that the risk allele (T) of rs1617640 creates a matrix match with the EVI1/MEL1 or AP1 binding site, accounting for an observed 25-fold enhancement of luciferase reporter expression as compared with the G allele. These results suggest that rs1617640 in the EPO promoter is significantly associated with PDR and ESRD. This study identifies a disease risk-associated gene and potential pathway mediating severe diabetic microvascular complications.

Footnotes

^dTo whom correspondence may be addressed. E-mail: zhenglin.yang{at}hsc.utah.edu, dean.li{at}hmbg.utah.edu, or kang.zhang{at}hsc.utah.edu
Author contributions: Z.T, Z.Y, and S.P. contributed equally to this work; Z.T., Z.Y., S.P., and K.Z. designed research; Z.T., Z.Y., S.P., H.C., D.G., X.Y., V.S.H., Y.K., J.H., E.P., J.B., Y.C., B.Y., N.H.T., N.A.Z., J.Z., L.L., J.K.S., M.P., R.N.H., S.T., R.C., C.C.R., S.S., R.L.A., J.M.B., N.L., A.L.A., G.L.K., P.S.B., and G.D.D.C.S.G. performed research; Z.T., Z.Y., D.G., S.W., G.D.D.C.S.G., L.B.J., D.Y.L., L.P.A., and M.R.P. analyzed data; and Z.T., Z.Y., S.P., D.Y.L., L.P.A., M.R.P., and K.Z. wrote the paper.
↵ ⁿGenetics of Diabetes and Diabetic Complication Study Group: Xiang Ma, D. Joshua Cameron, Melvin Rabena, Alex Goldfarb-Rumyantzev, Nick Banerjee, Hilary Keenan, Nick Mamalis, Charles Perez, and Bradley J. Katz.
This article is a PNAS Direct Submission.