Browsing by Author "Fonseca, Benedita V."
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- Convergence of miRNA expression profiling, α-synuclein interacton and GWAS in Parkinson's diseasePublication . Martins, Madalena; Rosa, Alexandra; Guedes, Leonor C.; Fonseca, Benedita V.; Gotovac, Kristina; Violante, Sara; Mestre, Tiago; Coelho, Miguel; Rosa, Mário M.; Martin, Eden R.; Vance, Jeffery M.; Outeiro, Tiago F.; Wang, Liyong; Borovecki, Fran; Ferreira, Joaquim J.; Oliveira, Sofia A.miRNAs were recently implicated in the pathogenesis of numerous diseases, including neurological disorders such as Parkinson’s disease (PD). miRNAs are abundant in the nervous system, essential for efficient brain function and play important roles in neuronal patterning and cell specification. To further investigate their involvement in the etiology of PD, we conducted miRNA expression profiling in peripheral blood mononuclear cells (PBMCs) of 19 patients and 13 controls using microarrays. We found 18 miRNAs differentially expressed, and pathway analysis of 662 predicted target genes of 11 of these miRNAs revealed an over-representation in pathways previously linked to PD as well as novel pathways. To narrow down the genes for further investigations, we undertook a parallel approach using chromatin immunoprecipitation-sequencing (ChIP-seq) analysis to uncover genome-wide interactions of a-synuclein, a molecule with a central role in both monogenic and idiopathic PD. Convergence of ChIP-seq and miRNomics data highlighted the glycosphingolipid biosynthesis and the ubiquitin proteasome system as key players in PD. We then tested the association of target genes belonging to these pathways with PD risk, and identified nine SNPs in USP37 consistently associated with PD susceptibility in three genome-wide association studies (GWAS) datasets (0.46#OR#0.63) and highly significant in the meta-dataset (3.3661024 ,p,1.9461023 ). A SNP in ST8SIA4 was also highly associated with PD (p = 6.1561023 ) in the meta-dataset. These findings suggest that several miRNAs may act as regulators of both known and novel biological processes leading to idiopathic PD.
- Mitochondrial haplogroup H1 is protective for ischemic stroke in portuguese patientsPublication . Rosa, Alexandra; Fonseca, Benedita V.; Krug, Tiago; Manso, Helena; Gouveia, Liliana; Albergaria, Isabel; Gaspar, Gisela; Correia, Manuel; Viana-Baptista, Miguel; Simões, Rita Moiron; Pinto, Amélia Nogueira; Taipa, Ricardo; Ferreira, Carla; Fontes, João Ramalho; Silva, Mário Rui; Gabriel, João Paulo; Matos, Ilda; Lopes, Gabriela; Ferro, José M; Vicente, Astrid M; Oliveira, Sofia A.Background: The genetic contribution to stroke is well established but it has proven difficult to identify the genes and the disease-associated alleles mediating this effect, possibly because only nuclear genes have been intensely investigated so far. Mitochondrial DNA (mtDNA) has been implicated in several disorders having stroke as one of its clinical manifestations. The aim of this case-control study was to assess the contribution of mtDNA polymorphisms and haplogroups to ischemic stroke risk. Methods: We genotyped 19 mtDNA single nucleotide polymorphisms (SNPs) defining the major European haplogroups in 534 ischemic stroke patients and 499 controls collected in Portugal, and tested their allelic and haplogroup association with ischemic stroke risk. Results: Haplogroup H1 was found to be significantly less frequent in stroke patients than in controls (OR = 0.61, 95% CI = 0.45–0.83, p = 0.001), when comparing each clade against all other haplogroups pooled together. Conversely, the pre-HV/HV and U mtDNA lineages emerge as potential genetic factors conferring risk for stroke (OR = 3.14, 95% CI = 1.41–7.01, p = 0.003, and OR = 2.87, 95% CI = 1.13–7.28, p = 0.021, respectively). SNPs m.3010G>A, m.7028C>T and m.11719G>A strongly influence ischemic stroke risk, their allelic state in haplogroup H1 corroborating its protective effect. Conclusion: Our data suggests that mitochondrial haplogroup H1 has an impact on ischemic stroke risk in a Portuguese sample