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Sp1 and Sp3 transcription factors mediate trichostatin A-induced and basal expression of extracellular superoxide dismutase.
Free Radic Biol Med. 2004 Oct 15; 37(8):1256-71.FR

Abstract

Extracellular superoxide dismutase (EC-SOD) is the major extracellular antioxidant enzyme and may play a critical role in the pathogenesis of a variety of pulmonary, neurological, and cardiovascular diseases. We report here that exposure to the deacetylase inhibitor trichostatin A (TSA) induces EC-SOD mRNA levels in mIMCD3 and Hepa 1-6 cells, but reduces EC-SOD mRNA levels in MLg cells. To determine the molecular mechanism of TSA-mediated EC-SOD gene regulation, we analyzed EC-SOD's proximal promoter region, which revealed two previously unknown but putative Sp1 cis elements. Transfection of systematically truncated 5'-flanking sequences revealed that the second Sp1 binding site contributes up to 70% of the constitutive EC-SOD promoter activity. Binding of Sp1 and Sp3 transcription factors to this region was confirmed by DNase I footprinting, electrophoretic mobility shift assay, super-shift assay, and chromatin immunoprecipitation. A dominant-negative Sp1 construct considerably reduced EC-SOD promoter activity in mammalian cells, whereas coexpression of Sp1 and Sp3 greatly enhanced reporter activity in SL2 cells. An EC-SOD promoter-reporter construct showed from 5- to 14-fold induction after exposure to TSA, whereas deletion of the Sp1 binding site significantly reduced reporter activation. These results are consistent with Sp1/Sp3 transcription factors providing essential TSA-dependent and basal transcription of the EC-SOD gene and may represent a novel pharmacological pathway for regulating EC-SOD levels in tissue.

Authors+Show Affiliations

Department of Medicine, Duke University Medical Center, Durham, NC 27710, USA.No affiliation info available

Pub Type(s)

Comparative Study
Journal Article
Research Support, U.S. Gov't, P.H.S.

Language

eng

PubMed ID

15451065

Citation

Zelko, Igor N., and Rodney J. Folz. "Sp1 and Sp3 Transcription Factors Mediate Trichostatin A-induced and Basal Expression of Extracellular Superoxide Dismutase." Free Radical Biology & Medicine, vol. 37, no. 8, 2004, pp. 1256-71.
Zelko IN, Folz RJ. Sp1 and Sp3 transcription factors mediate trichostatin A-induced and basal expression of extracellular superoxide dismutase. Free Radic Biol Med. 2004;37(8):1256-71.
Zelko, I. N., & Folz, R. J. (2004). Sp1 and Sp3 transcription factors mediate trichostatin A-induced and basal expression of extracellular superoxide dismutase. Free Radical Biology & Medicine, 37(8), 1256-71.
Zelko IN, Folz RJ. Sp1 and Sp3 Transcription Factors Mediate Trichostatin A-induced and Basal Expression of Extracellular Superoxide Dismutase. Free Radic Biol Med. 2004 Oct 15;37(8):1256-71. PubMed PMID: 15451065.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Sp1 and Sp3 transcription factors mediate trichostatin A-induced and basal expression of extracellular superoxide dismutase. AU - Zelko,Igor N, AU - Folz,Rodney J, PY - 2004/02/03/received PY - 2004/06/03/revised PY - 2004/06/17/accepted PY - 2004/9/29/pubmed PY - 2005/4/16/medline PY - 2004/9/29/entrez SP - 1256 EP - 71 JF - Free radical biology & medicine JO - Free Radic Biol Med VL - 37 IS - 8 N2 - Extracellular superoxide dismutase (EC-SOD) is the major extracellular antioxidant enzyme and may play a critical role in the pathogenesis of a variety of pulmonary, neurological, and cardiovascular diseases. We report here that exposure to the deacetylase inhibitor trichostatin A (TSA) induces EC-SOD mRNA levels in mIMCD3 and Hepa 1-6 cells, but reduces EC-SOD mRNA levels in MLg cells. To determine the molecular mechanism of TSA-mediated EC-SOD gene regulation, we analyzed EC-SOD's proximal promoter region, which revealed two previously unknown but putative Sp1 cis elements. Transfection of systematically truncated 5'-flanking sequences revealed that the second Sp1 binding site contributes up to 70% of the constitutive EC-SOD promoter activity. Binding of Sp1 and Sp3 transcription factors to this region was confirmed by DNase I footprinting, electrophoretic mobility shift assay, super-shift assay, and chromatin immunoprecipitation. A dominant-negative Sp1 construct considerably reduced EC-SOD promoter activity in mammalian cells, whereas coexpression of Sp1 and Sp3 greatly enhanced reporter activity in SL2 cells. An EC-SOD promoter-reporter construct showed from 5- to 14-fold induction after exposure to TSA, whereas deletion of the Sp1 binding site significantly reduced reporter activation. These results are consistent with Sp1/Sp3 transcription factors providing essential TSA-dependent and basal transcription of the EC-SOD gene and may represent a novel pharmacological pathway for regulating EC-SOD levels in tissue. SN - 0891-5849 UR - https://www.unboundmedicine.com/medline/citation/15451065/Sp1_and_Sp3_transcription_factors_mediate_trichostatin_A_induced_and_basal_expression_of_extracellular_superoxide_dismutase_ L2 - https://linkinghub.elsevier.com/retrieve/pii/S0891-5849(04)00493-9 DB - PRIME DP - Unbound Medicine ER -