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Browsing by Author "Costa, P.P."

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  • Apoe isoforms in patients with psoriasis
    Publication . Ferreira, J.C.P.; Torres, T.; Carvalho, C.A.; Bettencourt, A.; Leal, B.; Vasconcelos, C.; Costa, P.P.; Selores, M.; Silva, B.M.
    Introduction: Psoriasis is a chronic inflammatory skin disease affecting 2–3% of the world population. Patients with psoriasis (Ps) have higher prevalence of lipid disorders when compared to unaffected individuals. These patients, especially those with severe and prolonged disease, have an increased morbidity and mortality from cardiovascular events. Apolipoprotein E (ApoE), a protein involved in lipid metabolism, cholesterol and phospholipid transport, has functionally relevant gene variants. It has been described that the e4 allele may increase the risk to develop atherosclerosis, and the e2 allele has been associated with hyperlipoproteinemia type III. An increased risk of psoriasis among persons with these two alleles has also been reported. Nevertheless, the role of ApoE in Psoriasis remains controversial. Objectives: The aim of this work was to investigate the relationship between APOE-e2/e3/e4 variants and psoriasis in a Portuguese population. Materials and Methods: A cohort of 178 unrelated (74 females, 104 males) severe psoriatic patients [according to the Psoriasis Area and Severity Index (PASI)] from Centro Hospitalar do Porto/Hospital de Santo Ant onio and 285 ethnically-matched healthy controls were studied. Genotyping of APOE was performed using a Polymerase chain reaction restriction fragment-length polymorphism (PCR-RFLP) assay. Results: The frequency of the e4 allele was significantly higher in patients than in controls [(11.5% vs. 7.6%), p = 0.044, OR=1.57 (1.01–2.45)]. Conclusion: The ApoE e4 isoform could be a risk factor for psoriatic disease in this population. Our result is in agreement with previous studies in a Spanish population that associated the e4 isoform with severe psoriasis. These results support the hypothesis that ApoE has a modulatory role in inflammatory conditions.
    2013-07-03Conference object Open access Show more
  • Association between vitamin D receptor (VDR) gene polymorphisms and systemic lupus erythematosus in Portuguese patients
    Publication . Carvalho, C.; Marinho, A.; Leal, B.; Bettencourt, A.; Boleixa, D.; Almeida, I.; Farinha, F.; Costa, P.P.; Vasconcelos, C.; Silva, B.M.
    Systemic lupus erythematosus (SLE) is a chronic autoimmune disease of unknown origin, in which both genetic and environmental factors are involved. One such environmental factor is vitamin D, a vital hormone that plays a specific function in the immune system homeostasis, acting through a nuclear receptor (VDR) expressed in all immune cells. Several polymorphisms of the gene that encodes this receptor have been described. Though inconsistently, these polymorphisms have been associated with clinical manifestations and SLE development.The aim of this study was to determine the possible association between VDR gene polymorphisms (BsmI, ApaI, TaqI e FokI) and SLE susceptibility and severity, in a cohort of lupus patients from the north of Portugal.A total of 170 patients (F = 155, M = 15; age = 45 ± 13.4 years) with SLE (diagnosed according the American College of Rheumatology criteria) with at least five years of disease evolution and followed in the Autoimmune Disease Clinical Immunology Unit of Centro Hospitalar do Porto were studied. Patients and 192 ethnicity-matched controls were genotyped for BsmI (rs1544410), ApaI (rs7975232), TaqI (rs731236) and FokI (rs2228570) polymorphisms by TaqMan allelic discrimination assay. Disease severity was assessed by SLICC damage score, number of affected organs, number of severe flares and pharmacological history.SLE patients with the CT genotype of FokI polymorphism have a higher SLICC value (p = 0.031). The same result was observed for the group of patients with the TT genotype of TaqI polymorphism (p = 0.046). No differences were observed in VDR genotype between patients and controls. Also, we observed that the other clinical features analysed were not influenced by VDR polymorphisms.Our study confirms a possible role of VDR gene polymorphisms in SLE. A positive association was found between VDR polymorphisms and SLE severity (chronic damage). The presence of CT genotype of FokI and TT genotype of TaqI seems to confer a worse prognosis and may constitute a risk factor for higher long-term cumulative damage in SLE patients.
    2015-07Journal article Restricted access Show more
  • Comparative evolutionary analysis of IL6 in lagomorphs
    Publication . Neves, F.; Abrantes, J.; Costa, P.P.; Esteves, P.J.
    Background and aims: Interleukin 6 (IL6), also known as interferon beta 2, is a class-I helical cytokine with a broad spectrum of biological activities in humoral and cellular defense. This class of cytokines has a gene structure conserved throughout vertebrates, with five coding exons. IL6 is involved in the immune response against rabbit hemorrhagic disease virus that causes a highly fatal disease in the European rabbit. Previously, IL6 from European rabbit samples belonging to the subspecies Oryctolagus cuniculus cuniculus, was shown to differ from the other mammals by extending for further 27 amino acids. This difference results from a mutation in the typical stop codon into a glutamate encoding codon. However, in other leporids (Sylvilagus spp. and Lepus spp.) that diverged from European rabbit approximately 12 million years ago this mutation was also not present. The purpose of this study was to confirm the mutation of the stop codon in other lagomorph specimens: Oryctolagus cuniculus algirus, Brachylagus idahoensis, Sylvilagus bachmanii, Lepus europaeus and Ochotona princeps. Methods: The IL6 gene was PCR-amplified and sequenced for the five lagomorph species. The obtained sequences were translated and compared with other mammalian IL6 sequences retrieved from public databases (GenBank, Ensembl and Uniprot). A maximum-likelihood (ML) tree was inferred in MEGA5 with the following options: HKY+G model, 500 bootstrap replicates and partial deletion to gaps/missing data treatment. Results: We confirmed the presence of the mutated stop codon in both O. c. cuniculus and O. c. algirus. In agreement with previous reports, we found that the stop codon is not mutated in S. bachmanii and L. europaeus. We further extended this observation to the leporid B. idahoensis and ochotonid O. princeps. In rabbits, sequence translation of IL6 continues into the exonic sequence and stops in the next STOP codon (81 nucleotides downstream). Typically, the IL6 protein has five cysteine residues that might be important to establish disulfide bonds. In rabbit, the 27 amino acid extension has four more cysteine residues. The inferred phylogeny for the IL6 gene is in agreement with what has been accepted for the mammals and lagomorphs.Conclusions: Our results indicate that in the ancestral of the Oryctolagusgenus, (approximately 2 million years ago), a single mutation at exon 5 occurred that made IL6 longer than for the other mammals. Biological implications of this extension remain to be assessed but the occurrence of the 4 extra cysteine residues might suggest some functional relevance.
    2013-11-29Conference object Open access Show more
  • Epilepsy, hippocampal sclerosis and febrile seizures linked by common genetic variation around SCN1A
    Publication . Kasperavičiute, D.; Catarino, C.B.; Matarin, M.; Leu, C.; Novy, J.; Tostevin, A.; Leal, B.; Hessel, E.V.S.; Hallmann, K.; Hildebrand, M.S.; Dahl, H-H.M.; Ryten, M.; Trabzuni, D.; Ramasamy, A.; Alhusaini, S.; Doherty, C.P.; Dorn, T.; Hansen, J.; Krämer, G.; Steinhoff, B.J.; Zumsteg, D.; Duncan, S.; Kälviäinen, R.K.; Eriksson, K.J.; Kantanen, A-M; Pandolfo, M.; Gruber-Sedlmayr, U.; Schlachter, K.; Reinthaler, E.M.; Stogmann, E.; Zimprich, F.; Theatre, E.; Smith, C.; Obrien, T.J.; Tan, K.M.; Petrovski, S.; Robbiano, A.; Paravidino, R.; Zara, F.; Striano, P.; Sperling, M.R.; Buono, R.J.; Hakonarson, H.; Chaves, J.; Costa, P.P.; Silva, B.M.; Da Silva, A.M.; De Graan, P.N.E.; Koeleman, B.P.C.; Becker, A.; Schoch, S.; Von Lehe, M.; Reif, P.S.; Rosenow, F.; Becker, F.; Weber, Y.; Lerche, H.; Roessler, K.; Buchfelder, M.; Hamer, H.M.; Kobow, K.; Coras, R.; Blumcke, I.; Scheffer, I.E.; Berkovic, S.F.; Weale, M.E.; Delanty, N.; Depondt, C.; Cavalleri, G.L.; Kunz, W.S.; Sisodiya, S.M.
    Epilepsy comprises several syndromes, amongst the most common being mesial temporal lobe epilepsy with hippocampal sclerosis. Seizures in mesial temporal lobe epilepsy with hippocampal sclerosis are typically drug-resistant, and mesial temporal lobe epilepsy with hippocampal sclerosis is frequently associated with important co-morbidities, mandating the search for better understanding and treatment. The cause of mesial temporal lobe epilepsy with hippocampal sclerosis is unknown, but there is an association with childhood febrile seizures. Several rarer epilepsies featuring febrile seizures are caused by mutations in SCN1A, which encodes a brain-expressed sodium channel subunit targeted by many anti-epileptic drugs. We undertook a genome-wide association study in 1018 people with mesial temporal lobe epilepsy with hippocampal sclerosis and 7552 control subjects, with validation in an independent sample set comprising 959 people with mesial temporal lobe epilepsy with hippocampal sclerosis and 3591 control subjects. To dissect out variants related to a history of febrile seizures, we tested cases with mesial temporal lobe epilepsy with hippocampal sclerosis with (overall n = 757) and without (overall n = 803) a history of febrile seizures. Meta-analysis revealed a genome-wide significant association for mesial temporal lobe epilepsy with hippocampal sclerosis with febrile seizures at the sodium channel gene cluster on chromosome 2q24.3 [rs7587026, within an intron of the SCN1A gene, P = 3.36 × 10(-9), odds ratio (A) = 1.42, 95% confidence interval: 1.26-1.59]. In a cohort of 172 individuals with febrile seizures, who did not develop epilepsy during prospective follow-up to age 13 years, and 6456 controls, no association was found for rs7587026 and febrile seizures. These findings suggest SCN1A involvement in a common epilepsy syndrome, give new direction to biological understanding of mesial temporal lobe epilepsy with hippocampal sclerosis with febrile seizures, and open avenues for investigation of prognostic factors and possible prevention of epilepsy in some children with febrile seizures.
    2013-09-06Journal article Open access Show more
  • Erythropoietin in Familial Amyloidosis ATTR V30M
    Publication . Beirão, I.; Costa, P.P.
    Familial amyloidosis ATTR V30M is an hereditary disorder, the most frequent type of transthyretin related amyloidosis. The main manifestation of the disease is a sensory-motor and autonomic polyneuropathy. Other manifestations occur such as cardiovascular, gastrointestinal, ocular, renal and hematological disorders. Anemia is a common feature, and occurs late in the disease course. It is associated with low erythropoietin production. Decreased production can start early in the course of the disease and precede clinical symptoms. The possible underlying pathogenic mechanisms are discussed.
    2013Book part Restricted access Show more
  • Estrogen Metabolism-Associated CYP2D6 and IL6-174G/C Polymorphisms in Schistosoma haematobium Infection
    Publication . Cardoso, R.; Lacerda, P.C.; Costa, P.P.; Machado, A.; Carvalho, A.; Bordalo, A.; Fernandes, R.; Soares, R.; Richter, J.; Alves, H.; Botelho, M.C.
    Schistosoma haematobium is a human blood fluke causing a chronic infection called urogenital schistosomiasis. Squamous cell carcinoma of the urinary bladder (SCC) constitutes chronic sequelae of this infection, and S. haematobium infection is accounted as a risk factor for this type of cancer. This infection is considered a neglected tropical disease and is endemic in numerous countries in Africa and the Middle East. Schistosome eggs produce catechol-estrogens. These estrogenic molecules are metabolized to active quinones that induce modifications in DNA. The cytochrome P450 (CYP) enzymes are a superfamily of mono-oxygenases involved in estrogen biosynthesis and metabolism, the generation of DNA damaging procarcinogens, and the response to anti-estrogen therapies. IL6 Interleukin-6 (IL-6) is a pleiotropic cytokine expressed in various tissues. This cytokine is largely expressed in the female urogenital tract as well as reproductive organs. Very high or very low levels of IL-6 are associated with estrogen metabolism imbalance. In the present study, we investigated the polymorphic variants in the CYP2D6 gene and the C-174G promoter polymorphism of the IL-6 gene on S. haematobium-infected children patients from Guine Bissau. CYP2D6 inactivated alleles (28.5%) and IL6G-174C (13.3%) variants were frequent in S. haematobium-infected patients when compared to previously studied healthy populations (4.5% and 0.05%, respectively). Here we discuss our recent findings on these polymorphisms and whether they can be predictive markers of schistosome infection and/or represent potential biomarkers for urogenital schistosomiasis associated bladder cancer and infertility.
    2017-11-28Journal article Open access Show more
  • Evidence for an ancient origin of the FGA p.Glu545Val (E526V) amyloidosis-causing mutation endemic in Northern Portugal
    Publication . Costa, P.P.; Lacerda, P.C.; Oliveira, M.E.; Maia, N.; Lobato, Luísa; Santos, Rosário; Tavares, Isabel
    Fibrinogen alpha chain amyloidosis is widely spread throughout the world, and is most frequently associated with the FGA p.Glu545Val (E526V) mutation, particularly in European countries, with endemic foci of the disease identified in the UK and in northern Portugal. All identified Portuguese patients are from the same region, and a preliminary attempt to characterize the disease-associated haplotype hinted at a common ancestor, but whether this is true and how far back in time the founding event would have taken place is still much an open question. In order to address these questions we studied all available Portuguese patients and relatives, 56 individuals in total, 33 of which were mutation carriers, belonging to 12 extended families. Thirteen polymorphic short tandem-repeats spanning 5.8Mbps over the FGA gene in chromosome 4 were genotyped. A control population of 67 unrelated individuals was also genotyped for the same polymorphisms. Haplotype phasing was carried out using an empirical linkage disequilibrium-based method implemented in the Beagle 4.1 computer program, with some manual adjustments to take into account pedigree constraints and to preserve parsimony. In total 7 different but closely related disease-associated haplotypes were identified, the most frequent of which (I), represented in 5 families, was presumed to be the ancestral haplotype. The age of the E526V mutation in this population was estimated by fitting a multipoint LD model, as implemented in the DMLE+ program. While this model is somewhat sensitive to estimates of population growth and other parameters, it consistently predicted a mutation age above 100 generations (2500 years). These results point to a relatively ancient mutation, which could explain, at least in part, its wide dissemination throughout the world. It would be interesting to extend this study to other populations, to see if there is evidence for a common ancestor, and to try to establish a pattern of mutation dissemination.
    2020-09-14Conference object Open access Show more
  • Expression of adenosine kinase in human mesial temporal lobe epilepsy with hippocampal sclerosis: A preliminary study
    Publication . Leal, B.; Rangel, R.; Chaves, J.; Carvalho, C.; Bettencourt, A.; Zenatti, L.; Santos, A.; Magalhães, T.; Martins da Silva, A.; Correia de Sá, P.; Martins da Silva, B.; Costa, P.P.
    Background: Adenosine is a ubiquitous homeostatic molecule that acts as an “endogenous neuromodulator”. Adenosine attenuates neuronal activity either presynaptically by inhibiting neurotransmitter release or by controlling neurotransmitter responsiveness at post-synaptic sites. Unbalanced adenosine metabolism has been implicated in pathological conditions such as epilepsy. Adenosine kinase (ADK), synthetized by astrocytes, is the key regulator of extracellular adenosine levels in the brain. Evidences from experimental studies support a role for ADK in brain injury associated with astrogliosis, a morphological hallmark of Mesial Temporal Lobe Epilepsy with Hippocampal Sclerosis (MTLE-HS). In fact, expression of astrocytic ADK was found to be increased in the hippocampus and temporal cortex of MTLE-HS patients. Overexpression of ADK decreases extracellular adenosine and consequently may cause seizures. The aim of this study was to characterize ADK gene expression in MTLE-HS patients. Methods: Previous studies used immunohistochemistry and Western blot analysis to investigate ADK expression. Here we quantified the expression levels of ADK by Real-Time PCR in the hippocampus (lesional and peri-lesional cortical area) of 10 MTLE-HS patients submitted to surgery as compared with 9 autopsy controls with no history of neurological disorders. Results: Our results showed that ADK expression levels were similar in the hippocampus and temporal cortex of MTLE-HS patients when compared to healthy controls. Conclusion: Our preliminary data demonstrate that ADK expression levels are not altered in MTLE-HS. These results do not preclude post-transcriptional ADK abnormalities at both protein and functional levels. Our results should be confirmed in a larger cohort as well as with complementary methodologies.
    2013-09-22Conference object Restricted access Show more
  • Familial pseudoxanthoma elasticum with nephrocalcinosis: a case report
    Publication . Lacerda, P.; Beirão, I.; Pestana, P.; Beirão, J.M.; Freitas, C.; Rocha, M.J.; Cabrita, A.; Costa, P.P.
    Pseudoxanthoma elasticum (PXE) is an autosomal recessive genetic disorder characterized by progressive calcification and fragmentation of elastic fibres. PXE commonly involves the reticular dermis, the Bruch membrane of the eye, and blood vessels. PXE is caused by mutations in the ABCC6 gene. More than 300 pathogenic ABCC6 mutations are known. Two of these mutations are common: p.R1141X in exon 24, with a prevalence of 30%, and the Alu–mediated deletion of exons 23 to 29 (EX23_29del; p.A999_S1403del) found in 10-20% of patients. Homozygosity is rare. A 40-year-old female with a previous diagnosis of PXE was admitted in Nephrology Outpatient Clinic for nephrocalcinosis. She has two sisters, one of which also has a diagnosis of PXE and nephrocalcinosis. Physical examination revealed the presence of typical skin and ocular abnormalities. Microscopic and gross hematuria was reported in both affected sisters. Abdominal ultrasound confirmed bilateral cortico-medullar nephrocalcinosis. Calcium and phosphorus levels in blood and urine were normal. Hyperparathyroidism, renal tubular acidosis, hypervitaminosis D and hyperoxaluria were excluded. Renal biopsy showed only minor glomerular abnormalities. Medullary sponge kidney was identified by excretory urography. Genomic DNA was used as a template for PCR amplification of the region spanning introns 22 to 29 of ABCC6 [Pfendner et al., J Med Genet 2007;44:621-8]. The oligonucleotide cocktail used generated a 552bp PCR product for the normal sequence, and a 652bp product for the deletion mutation. Both sisters with PXE were homozygous for the EX23_29del mutation. The third sister did not carry this deletion. There are occasional reports of diffuse visceral calcifications (testis, mammary gland) in PXE. PXE-associated nephrocalcinosis was previously noted in four patients belonging to different families. This is the first report of familiar co-occurrence of PXE and nephrocalcinosis with medullary sponge kidney. These sisters’ peculiar phenotype could be due to their unusual genotype, or other shared genetic and environmental factors.
    2013-12-12Conference object Open access Show more
  • How genetic characterization of Narcolepsy and hypersomnia is useful on phenotype definition
    Publication . Martins da Silva, A.; Lopes, J.; Ramalheira, J.; Carvalho, C.; Costa, P.P.; Silva, B.M.
    Introduction. The determination of HLA class II genotype is widely used to confirm the diagnosis of narcolepsy with or without cataplexy. It is known from studies carried out in the 80’s and 90’s that genetic markers, particularly HLA-DR2 (HLA-DRB1*15) and later DQB1*06:02, are strongly associated with susceptibility to narcolepsy (N). First studies in 1984 showed values of 100% of positive HLA-DR2 (Langdon et al; Lancet 1984) in narcoleptic patients with cataplexy (NC). Mignot et al (Sleep 1997) found values of 76.1% of HLA-DQB1*06:02 positive in NC and 40.9% in N. More recent studies emphasize difference between children and adults for HLA-DQB1*06:02. Values of 93.7% (adults) vs 92.6% (children) in NC and a frequency of 78,6% in adults vs 52.9% in children were found in N (Nevsimalova et al; J Neurol 2013). The dissemination of HLA genotyping was the result of two convergent reasons: i) the method is reliable, easy to perform and reassures the clinician; ii) the assay is less invasive than other methodologies, namely those involving cerebrospinal fluid (CSF) samples. Another contributing factor is the wide acceptance of the hypothesis of an autoimmune origin for Narcolepsy (a clinical field in which the relevance of HLA system is generally accepted). This hypothesis finds support in the virtually absent levels of hypocretin peptides in the CSF of patients with NC, which is postulated to be due to the autoimmune destruction of hypocretin producing neurons (Burgess et al; J Neurosci 2012). Aims. To evaluate the contribution of genetic markers (HLA) to the differential diagnosis between narcolepsy with (NC) or without cataplexy (N) and hypersomnia (H) and their relevance in the context of our population (Northern Portugal). Patients and methods. A cohort of 113 patients with sleep and hypersomnia complaints were observed at the Outpatient Sleep Clinic from Hospital Santo Antonio/CH Porto and were assessed by clinical, night sleep polygraphic recording, MSLT on the following day, blood sampling in a routine method. Data from laboratory parameters was confronted with the clinical diagnostic hypothesis. Clinical reevaluation of the patients was considered if results did not match. Of these patients, classified as NC, N or H (according to ICSD2, 2005), 38 were NC (age at testing: mean, 32.8 years; median, 30 years); 13 N (age at testing: mean, 34.2 years; median: 36 years); 62 patients had H (age at testing: mean, 38.2 years; median, 40 years). We used a control population (CP) of 206 reportedly healthy individuals from the same geographic origin. The allele frequencies of the control population were confirmed and compared with a larger cohort of another population (2500 individuals) from the central and south regions of the country. Results. The frequency of HLA-DQB1*06:02 allele was overrepresented in N and NC patients (46% and 71% respectively), as expected, and the p value is extremely significant for NC (p < 0.0000). HLA-DQB1*02 frequency was also increased in the population with H when compared with the CP (55% vs 34%; p = 0.00396). Interestingly the frequency of the HLADQB1*03 allele was decreased in the NC vs CP group (34% vs 56%; p =0.012153). No differences were found in the HLA-DQB1*06:03 frequency between the cohort of patients and the control population. Conclusions. The HLA-DQB1*06:02 allele, a susceptibility factor to other autoimmune disorders (e.g.: MS, SLE, sarcoidosis, sclerosing cholangitis), was confirmed as a susceptibility allele also to NC in our population. The frequency of this allele in our NC patients (71%) is within the range of other studies. This value is lower when compared to studies concerning only patients with severe cataplexy (frequencies between 85-95%). Some of the differences could be due to phenotypic uncertainty or to the clinical picture evolution in different age groups (Nevsimalova et al; J Neurol 2013). Also a modification of hypocretin levels, by circadian or other oscillations and the influence of environmental factors (infections, head trauma, immunization) can be involved. The role of the potential regeneration of CNS tissue is also a subject to be explored. Given these uncertainties, genetic characterization has the potential to enhance the ability to carry out differential diagnosis among diverse excessive daytime sleepiness phenotypes, helping in the distinction of diverse entities corresponding to fundamentally different biological processes. Finally a matter to be explored is the role of HLADQB1*06:03 allele, considered by some authors as a protective factor to NC (Hor et al; Nat Genet 2010) (Van der Heide et al; Sleep 2012). Our study did not confirm this assumption.
    2013-03-16Conference object Restricted access Show more