The Human Angiotensin II Type 1 Receptor +1166 A/C Polymorphism Attenuates MicroRNA-155 Binding

Abstract

The adverse effects of angiotensin II (Ang II) are primarily mediated through the Ang II type 1 receptor (AT 1 R). A silent polymorphism (؉1166 A/C) in the human AT 1 R gene has been associated with cardiovascular disease, possibly as a result of enhanced AT 1 R activity. Because this polymorphism occurs in the 3-untranslated region of the human AT 1 R gene, the biological importance of this mutation has always been questionable. Computer alignment demonstrated that the ؉1166 A/C polymorphism occurred in a cis-regulatory site, which is recognized by a specific microRNA (miRNA), miR-155. miRNAs are noncoding RNAs that silence gene expression by base-pairing with complementary sequences in the 3-untranslated region of target RNAs. When the ؉1166 C-allele is present, base-pairing complementarity is interrupted, and the ability of miR-155 to interact with the cis-regulatory site is decreased. As a result, miR-155 no longer attenuates translation as efficiently as demonstrated by luciferase reporter and Ang II radioreceptor binding assays. In situ hybridization experiments demonstrated that mature miR-155 is abundantly expressed in the same cell types as the AT 1 R (e.g. endothelial and vascular smooth muscle). Finally, when human primary vascular smooth muscle cells were transfected with an antisense miR-155 inhibitor, endogenous human AT 1 R expression and Ang II-induced ERK1/2 activation were significantly increased. Taken together, our study demonstrates that the AT 1 R and miR-155 are co-expressed and that miR-155 translationally represses the expression of AT 1 R in vivo. Therefore, our study provides the first feasible biochemical mechanism by which the ؉1166 A/C polymorphism can lead to increased AT 1 R densities and possibly cardiovascular disease.

Variations of the perforin gene in patients with multiple sclerosis

“…The others did not influence canonical splicing sites, but they might theoretically influence perforin expression by disturbing exonic splicing enhancers, mRNA processing and transport, efficiency of codon usage by tRNA stability of mRNA secondary structure, protein folding or interaction with microRNA. [23][24][25][26][27][28] An alternative possibility is that they do not have a direct effect, but they are linkage disequilibrium with other unknown PRF1 mutations in the 5 0 UTR. However, we could not assess perforin expression because fresh cells from the carriers were not available.…”

The impact of microRNAs and alternative splicing in pharmacogenomics

“…Polymorphisms in miRNA target sites of protein-coding genes that are associated to cancer, [58][59][60] hypertension, 61 asthma, 62 cardiovascular disease 63 and polymorphisms in microRNAs that are associated with schizophrenia 40 were also described.…”

“…The authors suggest that allele-specific targeting of these miRNAs can account at least in part for the observations that HLA-G is associated with asthma. 62 In cardiovascular disease, Martin et al 63 reported an association of the human angiotensin II type 1 receptor polymorphism and miR-155. Finally, Hansen et al 40 identified important associations between brain-expressed miRNAs and schizophrenia for two SNPs located in mir-206 and mir-198 sequences.…”

Incomplete penetrance and variable expressivity: is there a microRNA connection?

“…Co-expression of target gene-miRNA pairs in affected tissue is shown for IP-VE genes. The numbers in parenthesis are the total number of genes/miRNA/ pairs for which expression data is available in the public domain Differential regulation of products of homologous alleles: polymorphism in miRNA target site SNP in the miRNA binding site can alter the interaction between the target site and miRNA, (73,74) and SNP in premiRNA can alter the biogenesis or the structure of the resulting mature miRNA (75) and, hence, the phenotype in question. When the source of miRNA is an intron, sequence polymorphism within the miRNA per se does not alter the mRNA of the source gene.…”