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- BPA analogues affect intestinal barrier integrity and pro-inflammatory response in a coculture modelPublication . Pereira, Gonçalo; Barros, Patrícia; Matos, Paulo; Jordan, PeterBackground: Bisphenol (BP) A and its structural analogues are environmental pollutants with endocrine-disrupting properties and potential immune-modulating effects. Following legal restrictions on the use of BPA, structurally related compounds including BPAP, BPP, and BPS-MAE have been introduced as alternatives; however, their potential hazardous profiles remain largely unknown. Here we used a coculture cell model to investigate the effects of exposure to these BP analogues on intestinal barrier integrity, intestinal cell stress, and pro-inflammatory macrophage activation. Methods: As cellular model, Caco-2 cells were grown on filter membranes to a polarized epithelium-like layer, and cocultured with underlying basolateral THP-1 derived M0 macrophages. After apical exposure of the Caco-2 cells layer to BPs (0.1 -100 µM for 24 h), we determined transepithelial electrical resistance (TEER), polarized cell morphology by confocal microscopy, cellular stress markers (p-p38MAPK, p-JNK, p-eIF2α) by Western blot, and macrophage activation by IL-1β-transcript expression changes. In addition, M0-type macrophages were also directly incubated with BPA for comparison. Results: When M0 macrophages were directly exposed, BPA triggered IL-1β expression, an effect more evident after macrophage sensitization by the presence of interferon-γ. Apical exposure to BPA and BPS-MAE had little effect on TEER but induced some increase in epithelial stress markers, while BPAP and especially BPP clearly reduced TEER and polarized cell morphology, and showed a tendency to induce stress markers. In addition, apical cell exposure to BPP and BPS-MAE triggered clear expression of the pro-inflammatory marker IL-1β in sensitized M0 macrophages cocultured at the basolateral side, whereas BPAP and BPA were only effective at the highest concentration. Conclusion: Together, our data show that exposure of an intestinal epithelium-like layer to BPAP and BPS-MAE revealed adverse cellular effects similar to BPA, while BPP was clearly the most deleterious BP analogue. Pro-inflammatory macrophage activation was strongest after exposure to BPP followed by BPS-MAE.
- Co-Inheritance of alpha-thalassemia and sickle cell disease in a cohort of Angolan pediatric patientsPublication . Santos, Brígida; Delgadinho, Mariana; Ginete, Catarina; Germano, Isabel; Miranda, Armandina; Arez, Ana Paula; Faustino, Paula; Brito, MiguelIntrodution: Sickle cell disease (SCD) is a recessive hereditary disease and a major global health problem, affecting over 300.000 newborn infants each year, and it is estimated that 75% of these births occur in Sub-Saharan Africa. SCD is a monogenic disease; the clinical manifestations are very heterogeneous due to environmental and genetic factors; in particular, the co-inheritance of alpha-thalassemia and an innate ability to produce fetal haemoglobin are two major modifiers that substantially impact disease pathophysiology. Objectives: This study explores the association between alpha-thalassemia, fetal haemoglobin, haematological indices, and clinical adverse events in pediatric Angolan sickle cell disease pediatric patients. Methods: A total of 200 SCD children were selected, after guardian written informed consent. None of them was treated with hydroxyurea or transfusion in the last 3 months. A venous blood sample was collected from each participant in the context of the routine medical and used for hematological analyses, fetal hemoglobin quantification, and genotyping of 3.7 kb alpha-thalassemia deletion by GAP-PCR. Mean values, standard deviation, and frequency distributions were performed to estimate the hematological, clinical, and genetic data. Results: The frequency of the 3.7 kb alpha-thalassemia deletion in homozygosity was 12.5%, and in heterozygosity was 55.0%. An increase in alpha-thalassemia frequency was observed in children older than 5 years old (11.7% vs. 13.00%). Furthermore, 3.7 kb alpha-thalassemia deletion homozygotes had a significantly higher age of the first manifestation, lower number of blood transfusions by year, higher haemoglobin, lower mean corpuscular volume, mean corpuscular haemoglobin, and lower hemolytic rate observed by a lower number of reticulocytes count. There were no differences in fetal haemoglobin between the three genotypes. Moreover, the number of stroke events, osteomyelitis, splenomegaly, splenectomy, and hepatomegaly were lower when alpha-thalassemia was co-inherited. Conclusion: The effect of alpha-thalassemia deletion in SCD was analysed, and results reinforce that this trait influences the haematological and clinical aspects and produces a milder phenotype.
- Deciphering the genetic modifiers of sickle cell anemia in children: the role of CYB5R3 genePublication . Nascimento, Djanira; Lopes, Pedro; Kjollerstrom, Paula; Maia, Raquel; Faria, Teresa; Faustino, PaulaIntroduction: Sickle cell anemia (SCA) is an autosomal recessive disorder caused by the c.20A>T alteration in the beta-globin gene (HBB), leading the synthesis of abnormal hemoglobin S (HbS). Under hypoxic conditions, HbS polymerizes within red blood cells (RBCs), causing them to adopt the characteristic sickle shape. This results in a clinically heterogenous disease, characterized by chronic hemolytic anemia, vaso-occlusive crises, and multi-organ damage. The CYB5R3 gene encodes the enzyme NADH-cytochrome b5 reductase 3, which plays a crucial role in protecting hemoglobin (Hb) from oxidative damage to unfunctional methemoglobin. Patients with SCA may develop methemoglobinemia, particularly under conditions of oxidative stress. This study aimed to evaluate the potential modulatory effects of a CYB5R3 variant, along with other well-established genetic modifiers within the globin genes, on the phenotypic variability of SCA in pediatric age. Methodology: Eighty-one children with SCA were followed by pediatricians at two hospitals in the Greater Lisbon area, who characterized their clinical, hematological, and biochemical phenotypes. For this specific study, CYB5R3, HBG2, HBA1, and HBA2 genes were genotyped using PCR, Sanger sequencing, and Gap-PCR. Association analyses were performed using SPSS. Results and Discussion: Co-inheritance of α-thalassemia with SCA was observed in 43.2% of the children and proved to be beneficial, as it was associated with higher RBC counts, milder anemia, and a significant reduction in hemolysis biomarkers (bilirubin and reticulocyte counts). Similarly, elevated fetal Hb levels (HbF ≥10%) were also beneficial, leading to less severe hemolytic anemia. In the HBG2 gene, the rs7482144_T allele had a frequency of 15% and was associated with higher HbF, reduced hemolytic parameters, lower HbS level, milder anemia, and a lower frequency of clinical comorbidities, except for heart disease. In the CYB5R3 gene, the rs1800457_G allele showed a very high allelic frequency of 35% and appears to exert a deleterious effect because patients carrying this allele presented with more severe anemia, elevated hemolysis biomarkers, and a greater tendency toward hepatomegaly and cardiac comorbidities. This study contributes to understanding how genetic modifiers influence SCA severity, complication risk and eventually treatment response. Identifying these factors supports personalized medicine and may help uncover new therapeutic targets.
- Dissecting the DIS3L2 target-specificity of transcripts committed to nonsense-mediated decay in human cellsPublication . Garcia-Moreno, Juan F.; Carvalho, Miguel P.; Lacerda, Rafaela; Romão, LuísaNonsense-mediated mRNA decay (NMD) is a conserved surveillance mechanism that eliminates mRNAs harboring premature termination codons (PTCs) and regulates the expression of certain physiological transcripts. The 3’-to-5’ exoribonuclease DIS3L2 degrades different RNAs independently of the RNA exosome, following uridylation at the 3' end by the terminal uridylyl transferases TUT4 and TUT7. We and others have shown that DIS3L2 is involved in NMD in an uridylation-dependent manner, being its function in NMD target-specific (Kurosaki et al. 2018; da Costa et al. 2019). Now, we aim to characterize the mechanisms involved in DIS3L2/NMD-target specificity. We used our RNA-seq data already obtained and validated and compared the transcripts upregulated upon DIS3L2 knockdown (REF) with a validated NMD-target set (Colombo et al., 2017). We observed that about 7% of DIS3L2-sensitive transcripts overlap with known NMD-targets. Considering the different groups of transcripts, we then analyzed specific features that make some NMD-targets sensitive to DIS3L2 (so called DIS3L2/NMD-targets; group 1), versus the remaining NMD-targets (DIS3L2-resistant NMD-targets; group 2), the remaining DIS3L2-sensitive targets (group 3), or the remaining transcriptome (DIS3L2-resistant NMD-targets plus NMD-resistant transcriptome; group 4). We assessed the following genomic features: 5’ and 3’ untranslated region (UTR) lengths, 3’UTR GC-, AU-, G-, C-, A-, and U-contents, presence of 5’UTR upstream open reading frames (uORFs), and 3’UTR introns. Elevated G-, C-, and GC-contents in the 3’UTRs were the most consistent features distinguishing DIS3L2/NMD-targets from the group 4. Comparison between group 1 and 2, and 1 and 3 was not significant. To better characterize the importance of each transcript portion, we are also analyzing hybrid constructs combining regions of the DIS3L2/NMD-resistant human β-globin (HBB) gene and the DIS3L2/NMD-sensitive GADD45A gene expressed in DIS3L2 depleted cultured cells.
- Early diagnosis of acid sphingomyelinase deficiency (ASMD) through biomarkers analysisPublication . Neiva, Raquel; da Silva Gaspar, Paulo Jorge Miranda; Sousa e Silva, Lisbeth Elena; Gonçalves, I.; Ferreira, S.; Diogo, Luisa; Vilarinho, LauraIntroduction: Acid sphingomyelinase deficiency (ASMD), historically known as Niemann–Pick disease (NPD) types A, A/B, and B, is a rare, progressive, potentially fatal lysosomal storage disease caused by pathogenic variants in SMPD1 gene. It presents a wide spectrum of symptoms, age of onset, and degree and type of organ effected. The disease manifestations frequently involve hepatosplenomegaly with progressive organ dysfunction, interstitial lung disease, and bleeding. In this work, we will present a patient whose lysosomal biomarkers study allowed the diagnosis of ASMD. Methods: This patient had hepatosplenomegaly, elevated transaminases in which the primary clinical suspicion was an acid lipase deficiency. By the analysis of our multiplex biomarker panel by LC-MS/MS analysis, we were able to do a differential diagnosis. Results/Case report: The lysosphingomyelin (lysoSM) and lysosphingomyelin-509 (lysoSm-509) were approximately 100 a 150x than normal, suggestive of Niemann–Pick disease. The diagnosis of ASMD was confirmed by reduced acid sphingomyelinase enzyme activity measured in peripheral blood leukocytes and the presence of a pathogenic variant in both alleles in the SMPD1 gene. Conclusion: ASMD can be underestimate and the diagnostic odissey arise from an overlap in symptomology with other diseases, including primary hepatic disease, Gaucher disease, Niemann–Pick disease, and lysosomal acid lipase deficiency. The multiplex biomarker panel, with different lysolipids, allows simultaneously diagnosis of different LSDs, in a timely manner, leading to an early intervention, before the appearance of more deleterious symtpoms.
- Is Antisense Oligonucleotide-Mediated Exon Skipping a Potential Therapeutic Approach for Mucolipidosis II?Publication . Gonçalves, Mariana; Moreira, Luciana; Encarnação, Marisa; Duarte, Ana Joana; Gaspar, Paulo; Santos, Juliana Inês; Coutinho Maria Francisca; Prata, Maria João; Omidi, Maryam; Pohl, Sandra; Silva, Frederico; Oliveira, Paula; Matos, Liliana; Alves, SandraIntridution: Mucolipidosis II (ML II) is a Lysosomal Storage Disorder caused by N-acetylglucosamine-1-phosphotransferase (GlcNAc-PT) deficiency, which impairs lysosomal hydrolases trafficking. Here, we explored an innovative therapeutic strategy based on the use of antisense oligonucleotides (ASOs) to promote targeted skipping of GNPTAB exon 19, which harbors c.3503_3504del, the most frequent disease-causing variant. Previously, in ML II patients’ fibroblasts, we tested ASOs to induce exon 19 skipping, successfully generating an in-frame mRNA1. Now, our aim is to determine if this in-frame transcript leads to increased GlcNAc-PT levels. Methodology: First, the GlcNAc-PT activity was measured in fibroblasts, but activity levels were similar in ML II and control fibroblasts (treated/non-treated) showing that the assay is not proper to measure endogenous levels. To overcome this, we designed 3 constructs: a WT (full GNPTAB cDNA), a del_ex19 (without exon 19) and a mutant (with the mutation c.3503_3504del) that were transfected in HEK293T cells. Then GlcNAc-PT expression was analyzed by Western Blot (WB). Also, we measured the activity of several hydrolases and evaluated the expression of α-galactosidase A (α-Gal) by WB after ASO treatment. To further validate this therapy we also generated a novel GlcNAc-PT antibody in rabbits. Results: Our results showed that HEK293T cells were able to express all the constructs. The WB of both WT and del_ex19 constructs showed bands corresponding to the α/β precursor. However, only the WT construct expressed the β-subunit, suggesting that there is no GlcNAc-PT activity in the absence of exon 19. As expected, in the delTC construct WB no α/β precursor band was detected. We also observed a slight increase in the activity of various lysosomal hydrolases in ML II fibroblasts after treatment. However, only the α-Gal values were statistically significant, but the WB analysis for this enzyme did not reveal any band in ASO-treated ML II cells. We also developed a novel antibody for GlcNAc-PT. Preliminary results showed a β-subunit band both in control and patient fibroblasts (unexpected), but in overexpression both WT and del_ex19 constructs presented α/β precursor bands. So, further assays are needed to assess its specificity. Conclusion: Our ASO-based approach effectively promotes exon 19 skipping. However, this strategy, as far as we have been able to prove, is not able to restore any GlcNAc-PT enzymatic activity. Further validation, including co-localization studies are planned to clarify these findings.
- Loss of BCL6 transcriptional repressor impacts migration but not viability in MCF-7 breast cancer cellsPublication . Dyson-Jorge, João; Jordan, Peter; Barros, Patrícia; Matos, PauloBreast cancer (BC) incidence has risen over the past two decades, now being the most prevalent cancer worldwide and the second leading cause of cancer-related deaths. Despite advancements in BC treatment, challenges like acquired resistance, recurrence, and metastasis persist. BCL6, a transcriptional repressor, acts as an oncogene in BC, being downregulated in about half of primary tumors of all BC subtypes and associated with disease progression and poor patient prognosis. This underscores the need to better understand BCL6 role in BC development. Therefore, we used RNA interference to explore the impact of BCL6 depletion on the oncogenic progression of MCF-7 cells, a low-tumorigenic estrogen receptor-positive cell line. While BCL6 is known to regulate normal mammary cell proliferation and differentiation, its depletion did not affect MCF-7 cell proliferation or viability but significantly reduced their individual and collective migratory properties. RNA microarray analysis identified a set of genes upregulated following BCL6 depletion, including S100A7, previously reported to inhibit MCF-7 cell migration and invasion by reducing MMP9 secretion. However, our findings showed that S100A7 downregulation alone did not affect MCF-7 migration. Moreover, simultaneous depletion of BCL6 and S100A7 failed to restore MCF-7 cell migratory behavior.
- Olipudase alfa enzyme replacement therapy. One-year outcomes in an adult patient with acid sphingomyelinase deficiency type BPublication . Cardoso, M.; Chaves, P.C.; Pintalhão, M.; da Silva Gaspar, Paulo Jorge Miranda; Castro, R.; Bastos, J.; Silva, A.; Campos, T.; Macedo, Fatima; Rodrigues, E.; Leão Teles, ElisaIntroduction: Acid Sphingomyelinase Deficiency (ASMD) is a rare autosomal recessive lysosomal storage disorder caused by variants in the SMPD1 gene, leading to a deficiency in the activity of sphingomyelinase (ASM) that catabolizes sphingomyelin (SPM). ASMD Type B is a late-onset, severe disease characterized by progressive hepatosplenomegaly, gradual deterioration of liver and pulmonary function, osteopenia and an atherogenic lipid profile. Olipudase alfa is a recombinant human ASM enzyme replacement therapy indicated for the treatment of non-C-NS manifestations of ASMD.
- The potential function of alternative translation initiation of Argonaute 1 in cancerPublication . Vieira da Silva, Verónica; Lacerda, Rafaela; Romão, LuísaTranslation is one of the most regulated and energy-consuming cellular processes crucial for proper cell function. Translation is initiated by the canonical cap-dependent mechanism. However, under stress conditions, the initiation of canonical translation is inhibited, which allows the translation of specific proteins via alternative mechanisms. This project aims to understand the biological relevance of alternative protein synthesis mechanisms in Argonaute 1 (AGO1) expression. The AGO1 protein is involved in microRNA regulation, gene expression modulation and inhibition. AGO1 is also involved in the regulation of gene expression by RNA interference (RNAi), and its deregulation can lead to the activation of oncogenes or the suppression of tumor suppressor genes, contributing to the development and progression of cancer. Our work has shown that AGO1 mRNA can be translated through a cap-independent initiation mechanism. An upstream open reading frame (uORF) has also been identified in its 5’ untranslated region (5’UTR), which may play a role in the initiation of AGO1 translation. The results showed that the 5’UTR of human AGO1 supports a cap-independent mechanism of translation initiation, which is maintained under stress conditions. However, our analyses did not provide conclusive evidence for a regulatory role of the uORF in this initiation process. To this end, the 5’UTR of human AGO1 was cloned into a bicistronic vector containing Renilla (RLuc) and Firefly luciferase (FLuc), with FLuc positioned downstream of the 5’UTR. Luminometry assays will be used to evaluate the relative FLuc/RLuc translation efficiency under the control of the AGO1 5’UTR. The same approach will be used with monocistronistic reporter vectors, contaning only FLuc. This project aims to understand how these alternative mechanisms of mRNA translation initiation can influence AGO1 expression and help explain their potential roles in certain pathologies and cancer progression, such as colorectal cancer.
- Public genomic cohort analyses reveal bcl6 expression as a prognostic marker in luminal a breast cancerPublication . Barros, Patrícia; Gonçalves, Vânia; Jordan, Peter; Matos, PauloIntroduction: Breast cancer (BC) is the most common malignant neoplasm among women worldwide and remains a leading cause of cancer-related mortality. It is a heterogeneous disease classified into molecular subtypes with distinct prognostic and therapeutic implications. Luminal A is the most prevalent subtype, characterised by high expression of hormone receptors (oestrogen and progesterone), low proliferation rate, and generally favourable prognosis. However, consistent evidence indicates a significant risk of late recurrence and new neoplastic events, posing challenges for clinical follow-up strategies. Methodology: We analysed genomic data from the TCGA breast cancer cohort (n = 1247) to assess the prognostic value of the BCL6 gene, a transcriptional regulator previously implicated in tumour progression. Data on BCL6 expression, molecular subtyping (PAM50), and overall survival (OS) were retrieved. Results: Although BCL6 expression was globally reduced in tumours compared to normal tissue, it was significantly higher in Luminal A tumours than in other subtypes, with a subgroup (44%) maintaining expression levels similar to normal tissue. Importantly, within the Luminal A subtype, higher BCL6 expression was associated with poorer long term survival (p = 0.041). Discussion: These findings support the potential of BCL6 as a stratification biomarker for the risk of long term neoplasm recurrence within Luminal A breast cancer, with possible implications for tailoring the intensity and duration of clinical follow-up.