Hypoxia‐Inducible Factor‐1α Is Constitutively Expressed in Murine Leydig Cells and Regulates 3β‐Hydroxysteroid Dehydrogenase Type 1 Promoter Activity

Wiley - Tập 30 Số 2 - Trang 146-156 - 2009
Jeffrey J. Lysiak1, Jennifer L. Kirby2, Jacques Tremblay3, Robin I. Woodson1, Michael A. Reardon1, Lisa A. Palmer4, Terry T. Turner5,1
1Department of Urology, University of Virginia Health System, Charlottesville, Virginia
2Department of Endocrinology, University of Virginia Health System, Charlottesville, Virginia
3The Centre for Research in Biology of Reproduction, Department of Obstetrics and Gynecology, Laval University, Quebec City, Canada
4Department of Pediatrics, University of Virginia Health System, Charlottesville, Virginia
5Department of Cell Biology, University of Virginia Health System, Charlottesville, Virginia.

Tóm tắt

ABSTRACT: Hypoxia‐inducible factor‐1α (HIF‐1α) is a transcription factor that plays an essential role in oxygen homeostasis. HIF‐1α is constitutively made in cells; however, it is ubiquitinated and degraded under normoxic conditions. Hypoxia prevents the ubiquitination of HIF‐1α, resulting in stabilization of the protein and activation of target genes. Because of its vascular arrangement and the high metabolic demand of spermatogenesis, the testis has been described previously as functioning on the brink of hypoxia; thus, we have hypothesized that HIF‐1α is constitutively expressed and stabilized in the testis, where it could play a role in testicular homeostasis. Western blot analysis using nuclear proteins from liver, kidney, and testis revealed the presence of HIF‐1α only in the testis. Immunohistochemistry confirmed this result and revealed that HIF‐1α was specifically located in interstitial Leydig cells. Electromobility shift assays employing nuclear extracts from the TM3 Leydig cell line revealed that these cells express HIF‐1α that is capable of binding DNA under normoxic conditions. Furthermore, we found that protein levels can be increased further when the TM3 cells are cultured under hypoxic conditions. Finally, transient transfections of TM3 Leydig cells revealed that the promoter of the mouse 3β‐hydroxysteroid dehydrogenase type 1 (Hsd3b1) gene, which encodes a key enzyme in testosterone production, is a potential target of HIF‐1α. In conclusion, HIF‐1α is constitutively present in the Leydig cells of the murine testis, where it potentially regulates Hsd3b1 transcription, and thus male reproductive function.

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Tài liệu tham khảo

10.1385/ENDO:25:3:265

10.1111/j.1745-7262.2006.00178.x

10.1158/0008-5472.CAN-03-0145

10.1530/jrf.0.0030377

10.1095/biolreprod.104.027797

10.1095/biolreprod14.4.481

10.1210/endo-121-4-1390

10.1016/S0303-7207(01)00461-0

10.1016/S0165-0378(02)00020-7

10.1080/03602530600570040

10.1101/gad.12.2.149

10.1126/science.1059796

10.1074/jbc.271.30.17771

10.1152/ajpcell.1996.271.4.C1172

10.1098/rstb.1970.0052

10.1101/gad.991402

10.1126/science.1068592

10.1095/biolreprod63.5.1383

10.1095/biolreprod65.3.718

10.1007/s00441-006-0341-y

Ma W., 2003, Hepatic vascular tumors, angiectasis in multiple organs, and impaired spermatogenesis in mice with conditional inactivation of the VHL gene, Cancer Res, 63, 5320

10.4049/jimmunol.171.12.6534

10.1210/me.16.2.234

10.4161/cbt.3.1.547

10.1113/expphysiol.2005.030924

10.1073/pnas.94.15.8104

10.1007/978-1-4757-3401-0_24

10.1038/20459

10.1016/j.reprotox.2004.11.011

10.1002/dvdy.20689

10.1152/ajpcell.00614.2005

10.1210/endo.139.3.5788

10.1095/biolreprod.101.002576

10.1111/j.1749-6632.1984.tb38363.x

Quinn PG, 1984, Oxygen‐mediated damage of microsomal cytochrome P‐450 enzymes in cultured leydig cells. Role in steroidogenic desensitization, J Biol Chem, 259, 4130, 10.1016/S0021-9258(17)43019-5

Ryan HE, 2000, Hypoxia‐inducible factor‐1alpha is a positive factor in solid tumor growth, Cancer Res, 60, 4010

10.1038/ng1266

10.1113/jphysiol.1964.sp007387

10.1530/jrf.0.0930233

10.1016/j.semcdb.2005.03.008

10.1038/sj.onc.1210149

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Wiley

Tập 30 Số 2

146-156

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