Dataset Information

MicroRNA-298 and microRNA-328 regulate expression of mouse beta-amyloid precursor protein-converting enzyme 1.

ABSTRACT: MicroRNAs (miRNAs) are key regulatory RNAs known to repress mRNA translation through recognition of specific binding sites located mainly in their 3'-untranslated region (UTR). Loss of specific miRNA control of gene expression is thus expected to underlie serious genetic diseases. Intriguingly, previous post-mortem analyses showed higher beta-amyloid precursor protein-converting enzyme (BACE) protein, but not mRNA, levels in the brain of patients that suffered from Alzheimer disease (AD). Here we also observed a loss of correlation between BACE1 mRNA and protein levels in the hippocampus of a mouse model of AD. Consistent with an impairment of miRNA-mediated regulation of BACE1 expression, these findings prompted us to investigate the regulatory role of the BACE1 3'-UTR element and the possible involvement of specific miRNAs in cultured neuronal (N2a) and fibroblastic (NIH 3T3) cells. Through various experimental approaches, we validated computational predictions and demonstrated that miR-298 and miR-328 recognize specific binding sites in the 3'-UTR of BACE1 mRNA and exert regulatory effects on BACE1 protein expression in cultured neuronal cells. Our results may provide the molecular basis underlying BACE1 deregulation in AD and offer new perspectives on the etiology of this neurological disorder.

SUBMITTER: Boissonneault V

PROVIDER: S-EPMC2908704 | biostudies-literature | 2009 Jan

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

MicroRNA-298 and microRNA-328 regulate expression of mouse beta-amyloid precursor protein-converting enzyme 1.

Boissonneault Vincent V Plante Isabelle I Rivest Serge S Provost Patrick P

The Journal of biological chemistry 20081105 4

MicroRNAs (miRNAs) are key regulatory RNAs known to repress mRNA translation through recognition of specific binding sites located mainly in their 3'-untranslated region (UTR). Loss of specific miRNA control of gene expression is thus expected to underlie serious genetic diseases. Intriguingly, previous post-mortem analyses showed higher beta-amyloid precursor protein-converting enzyme (BACE) protein, but not mRNA, levels in the brain of patients that suffered from Alzheimer disease (AD). Here w ...[more]

PMID: 18986979

Similar Datasets

Project description:UnlabelledAngiotensin-1-converting enzyme (ACE), a zinc metallopeptidase, consists of two homologous catalytic domains (N and C) with different substrate specificities. Here we report kinetic parameters of five different forms of human ACE with various amyloid beta (Aβ) substrates together with high resolution crystal structures of the N-domain in complex with Aβ fragments. For the physiological Aβ(1-16) peptide, a novel ACE cleavage site was found at His14-Gln15. Furthermore, Aβ(1-16) was preferentially cleaved by the individual N-domain; however, the presence of an inactive C-domain in full-length somatic ACE (sACE) greatly reduced enzyme activity and affected apparent selectivity. Two fluorogenic substrates, Aβ(4-10)Q and Aβ(4-10)Y, underwent endoproteolytic cleavage at the Asp7-Ser8 bond with all ACE constructs showing greater catalytic efficiency for Aβ(4-10)Y. Surprisingly, in contrast to Aβ(1-16) and Aβ(4-10)Q, sACE showed positive domain cooperativity and the double C-domain (CC-sACE) construct no cooperativity towards Aβ(4-10)Y. The structures of the Aβ peptide-ACE complexes revealed a common mode of peptide binding for both domains which principally targets the C-terminal P2' position to the S2' pocket and recognizes the main chain of the P1' peptide. It is likely that N-domain selectivity for the amyloid peptide is conferred through the N-domain specific S2' residue Thr358. Additionally, the N-domain can accommodate larger substrates through movement of the N-terminal helices, as suggested by the disorder of the hinge region in the crystal structures. Our findings are important for the design of domain selective inhibitors as the differences in domain selectivity are more pronounced with the truncated domains compared to the more physiological full-length forms.DatabaseThe atomic coordinates and structure factors for N-domain ACE with Aβ peptides 4-10 (5AM8), 10-16 (5AM9), 1-16 (5AMA), 35-42 (5AMB) and (4-10)Y (5AMC) complexes have been deposited in the Protein Data Bank, Research Collaboratory for Structural Bioinformatics, Rutgers University, New Brunswick, NJ, USA (http://www.rcsb.org/).

Project description:BackgroundHyperactivity of the classical axis of the renin-angiotensin system (RAS), mediated by angiotensin II (Ang II) activation of the angiotensin II type 1 receptor (AT1R), is implicated in the pathogenesis of Alzheimer's disease (AD). Angiotensin-converting enzyme-2 (ACE-2) degrades Ang II to angiotensin 1-7 (Ang (1-7)) and counter-regulates the classical axis of RAS. We have investigated the expression and distribution of ACE-2 in post-mortem human brain tissue in relation to AD pathology and classical RAS axis activity.MethodsWe measured ACE-2 activity by fluorogenic peptide substrate assay in mid-frontal cortex (Brodmann area 9) in a cohort of AD (n = 90) and age-matched non-demented controls (n = 59) for which we have previous data on ACE-1 activity, amyloid β (Aβ) level and tau pathology, as well as known ACE1 (rs1799752) indel polymorphism, apolipoprotein E (APOE) genotype, and cerebral amyloid angiopathy severity scores.ResultsACE-2 activity was significantly reduced in AD compared with age-matched controls (P < 0.0001) and correlated inversely with levels of Aβ (r = -0.267, P < 0.001) and phosphorylated tau (p-tau) pathology (r = -0.327, P < 0.01). ACE-2 was reduced in individuals possessing an APOE ε4 allele (P < 0.05) and was associated with ACE1 indel polymorphism (P < 0.05), with lower ACE-2 activity in individuals homozygous for the ACE1 insertion AD risk allele. ACE-2 activity correlated inversely with ACE-1 activity (r = -0.453, P < 0.0001), and the ratio of ACE-1 to ACE-2 was significantly elevated in AD (P < 0.0001). Finally, we show that the ratio of Ang II to Ang (1-7) (a proxy measure of ACE-2 activity indicating conversion of Ang II to Ang (1-7)) is reduced in AD.ConclusionsTogether, our findings indicate that ACE-2 activity is reduced in AD and is an important regulator of the central classical ACE-1/Ang II/AT1R axis of RAS, and also that dysregulation of this pathway likely plays a significant role in the pathogenesis of AD.

Dataset Information

MicroRNA-298 and microRNA-328 regulate expression of mouse beta-amyloid precursor protein-converting enzyme 1.

Publications

MicroRNA-298 and microRNA-328 regulate expression of mouse beta-amyloid precursor protein-converting enzyme 1.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets