title: Allelic imbalance of tissue-type plasminogen activator (t-PA) gene expression in human brain tissue.
abstract: We have identified a single-nucleotide polymorphism (SNP) in the t-PA enhancer (-7351C>T), which is associated with endothelial t-PA release in vivo. In vitro studies demonstrated that this SNP is functional at the level of transcription. In the brain, t-PA has been implicated in both physiologic and pathophysiologic processes. The aim of the present study was to examine the effect of the t-PA -7351C>T SNP on t-PA gene expression in human brain tissue. Allelic mRNA expression was measured in heterozygous post-mortem brain tissues using quantitative TaqMan genotyping assay. Protein-DNA interactions were assessed using electrophoretic mobility shift assay (EMSA) and chromatin immunoprecipitation (ChIP). Significantly higher levels of t-PA mRNA were generated from chromosomes that harboured the wild-type -7351C allele, as compared to those generated from the mutant T allele (for the hippocampus, C to T allelic ratio of ~1.3, p=0.010, n=12; and for the cortex, C to T allelic ratio of ~1.2, p=0.017, n=12). EMSA showed reduced neuronal and astrocytic nuclear protein binding affinity to the T allele, and identified Sp1 and Sp3 as the major transcription factors that bound to the -7351 site. ChIP analyses confirmed that Sp1 recognises this site in intact cells. In conclusion, the t-PA -7351C>T SNP affects t-PA gene expression in human brain tissue. This finding might have clinical implications for neurological conditions associated with enhanced t-PA levels, such as in the acute phase of cerebral ischaemia, and also for stroke recovery.
authors: Institute of Neuroscience and Physiology, Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden.
authors: A
authors: A
authors: Tjarnlund-Wolf
authors: K
authors: K
authors: Hultman
authors: M A
authors: MA
authors: Curtis
authors: R L M
authors: RL
authors: Faull
authors: R L
authors: RL
authors: Medcalf
authors: C
authors: C
authors: Jern
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000483:Alleles; D001253:Astrocytes / Q000378:metabolism* / Q000473:pathology; D001921:Brain / Q000473:pathology; D002545:Brain Ischemia / Q000235:genetics / Q000378:metabolism*; D004252:DNA Mutational Analysis; D004742:Enhancer Elements, Genetic / Q000235:genetics; D005260:Female; D005786:Gene Expression Regulation; D006801:Humans; D008297:Male; D008875:Middle Aged; D009154:Mutation / Q000235:genetics; D009474:Neurons / Q000378:metabolism* / Q000473:pathology; D020641:Polymorphism, Single Nucleotide; D011485:Protein Binding / Q000235:genetics; D020521:Stroke / Q000235:genetics / Q000378:metabolism*; D010959:Tissue Plasminogen Activator / Q000235:genetics / Q000378:metabolism*
chemical_list: D010959:Tissue Plasminogen Activator