Browsing by Author "Calado, Sofia"
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- Advancing glioblastoma research with innovative brain organoid-based modelsPublication . Dias Correia, Cátia; Calado, Sofia; Matos, Alexandra; Oleiro Esteves, Filipa Alexandra; De Sousa-Coelho, Ana Luísa; Campinho, Marco António; Teotónio Fernandes, Mónica AlexandraGlioblastoma (GBM) is a relatively rare but highly aggressive form of brain cancer characterized by rapid growth, invasiveness, and resistance to standard therapies. Despite significant progress in understanding its molecular and cellular mechanisms, GBM remains one of the most challenging cancers to treat due to its high heterogeneity and complex tumor microenvironment. To address these obstacles, researchers have employed a range of models, including in vitro cell cultures and in vivo animal models, but these often fail to replicate the complexity of GBM. As a result, there has been a growing focus on refining these models by incorporating human-origin cells, along with advanced genetic techniques and stem cell-based bioengineering approaches. In this context, a variety of GBM models based on brain organoids were developed and confirmed to be clinically relevant and are contributing to the advancement of GBM research at the preclinical level. This review explores the preparation and use of brain organoid-based models to deepen our understanding of GBM biology and to explore novel therapeutic approaches. These innovative models hold significant promise for improving our ability to study this deadly cancer and for advancing the development of more effective treatments.
- Altered bone microarchitecture in a type 1 diabetes mouse model Ins2 (Akita)Publication . Pires De Carvalho, Filipe Ricardo; Calado, Sofia; Silva, Gabriela A.; Diogo, Gabriela S.; Moreira da Silva, Joana; Reis, Rui L.; Cancela, M. Leonor; Gavaia, PauloType 1 diabetes mellitus (T1DM) has been associated to several cartilage and bone alterations including growth retardation, increased fracture risk, and bone loss. To determine the effect of long term diabetes on bone we used adult and aging Ins2 Akita mice that developed T1DM around 3-4 weeks after birth. Both Ins2 Akita and wild-type (WT) mice were analyzed at 4, 6, and 12 months to assess bone parameters such as femur length, growth plate thickness and number of mature and preapoptotic chondrocytes. In addition, bone microarchitecture of the cortical and trabecular regions was measured by microcomputed tomography and gene expression of Adamst-5, Col2, Igf1, Runx2, Acp5, and Oc was quantified by quantitative real-time polymerase chain reaction. Ins2 Akita mice showed a decreased longitudinal growth of the femur that was related to decreased growth plate thickness, lower number of chondrocytes and to a higher number of preapoptotic cells. These changes were associated with higher expression of Adamst-5, suggesting higher cartilage degradation, and with low expression levels of Igf1 and Col2 that reflect the decreased growth ability of diabetic mice. Ins2 Akita bone morphology was characterized by low cortical bone area (Ct.Ar) but higher trabecular bone volume (BV/TV) and expression analysis showed a downregulation of bone markers Acp5, Oc, and Runx2. Serum levels of insulin and leptin were found to be reduced at all-time points Ins2 Akita . We suggest that Ins2 Akita mice bone phenotype is caused by lower bone formation and even lower bone resorption due to insulin deficiency and to a possible relation with low leptin signaling.
- Cationic polyene phospholipids as DNA carriers for ocular gene therapyPublication . Machado, Susana; Calado, Sofia; Bitoque, Diogo; Oliveira, Ana Vanessa; Øpstad, Christer L.; Zeeshan, Muhammad; Sliwka, Hans-Richard; Partali, Vassilia; Pungente, Michael D.; Silva, GabrielaRecent success in the treatment of congenital blindness demonstrates the potential of ocular gene therapy as a therapeutic approach. The eye is a good target due to its small size, minimal diffusion of therapeutic agent to the systemic circulation, and low immune and inflammatory responses. Currently, most approaches are based on viral vectors, but efforts continue towards the synthesis and evaluation of new nonviral carriers to improve nucleic acid delivery. Our objective is to evaluate the efficiency of novel cationic retinoic and carotenoic glycol phospholipids, designated C20-18, C20-20, and C30-20, to deliver DNA to human retinal pigmented epithelium (RPE) cells. Liposomes were produced by solvent evaporation of ethanolic mixtures of the polyene compounds and coformulated with 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE) or cholesterol (Chol). Addition of DNA to the liposomes formed lipoplexes, which were characterized for binding, size, biocompatibility, and transgene efficiency. Lipoplex formulations of suitable size and biocompatibility were assayed for DNA delivery, both qualitatively and quantitatively, using RPE cells and a GFP-encoding plasmid. The retinoic lipoplex formulation with DOPE revealed a transfection efficiency comparable to the known lipid references 3β-[N-(N',N'-dimethylaminoethane)-carbamoyl]-cholesterol (DC-Chol) and 1,2-dioleoyl-sn-glycero-3-ethylphosphocholine (EPC) and GeneJuice. The results demonstrate that cationic polyene phospholipids have potential as DNA carriers for ocular gene therapy.
- CITED2 and the modulation of the hypoxic response in cancerPublication . Fernandes, Mónica T; Calado, Sofia; Mendes-Silva, Leonardo; Bragança, JoséCITED2 (CBP/p300-interacting transactivator with Glu/Asp-rich C-terminal domain, 2) is a ubiquitously expressed protein exhibiting a high affinity for the CH1 domain of the transcriptional co-activators CBP/p300, for which it competes with hypoxia-inducible factors (HIFs). CITED2 is particularly efficient in the inhibition of HIF-1α-dependent transcription in different contexts, ranging from organ development and metabolic homeostasis to tissue regeneration and immunity, being also potentially involved in various other physiological processes. In addition, CITED2 plays an important role in inhibiting HIF in some diseases, including kidney and heart diseases and type 2-diabetes. In the particular case of cancer, CITED2 either functions by promoting or suppressing cancer development depending on the context and type of tumors. For instance, CITED2 overexpression promotes breast and prostate cancers, as well as acute myeloid leukemia, while its expression is downregulated to sustain colorectal cancer and hepatocellular carcinoma. In addition, the role of CITED2 in the maintenance of cancer stem cells reveals its potential as a target in non-small cell lung carcinoma and acute myeloid leukemia, for example. But besides the wide body of evidence linking both CITED2 and HIF signaling to carcinogenesis, little data is available regarding CITED2 role as a negative regulator of HIF-1α specifically in cancer. Therefore, comprehensive studies exploring further the interactions of these two important mediators in cancer-specific models are sorely needed and this can potentially lead to the development of novel targeted therapies.
- Common mechanistic pathways in rare congenital syndromes with primary microcephalyPublication . Jorge, Xavier; Milagre, Ines; Ferreira, Anita; Calado, Sofia; Oliveira, Raquel; Carvalhal, SaraPrimary microcephaly is an often-seen phenotype in several rare congenital syndromes. It is characterised by a smaller brain size at birth compared to the norm. The causes of this malformation are not fully understood, but genetic testing suggests a connection with defective genes involved in mitotic regulation and proteins related to DNA repair and replication pathways. Cohesinopathies represent a group of rare syndromes, where several subtypes exhibit spontaneous railroad chromosomes and primary microcephaly. This includes Roberts Syndrome, Warsaw Breakage Syndrome and a recently characterised syndrome caused by mutations in the BUB1 gene. Currently, we are examining fibroblast cells from patients with these syndromes to identify common mechanistic pathways. In this context, we have identified a new promising candidate: Topoisomerase II alpha, a protein responsible for resolving of the DNA catenation both in the DNA replication and mitosis. Defective localisation of Topoisomerase II alpha may contribute to the observed mitotic defects in these cells. We are currently exploring the impact of these defects on brain development using reprogramming techniques to assess proper neuronal differentiation.
- Establishment of an induced pluripotent cell line (ABCRIi001-A) from an elderly female for ageing researchPublication . Esteves, Filipa; Vilhena Catarino Brito, David; Rajado, Ana Teresa; Silva, Nádia; Apolónio, Joana; Roberto, Vânia; Andrade, Raquel; Calado, Sofia; Faleiro, Maria Leonor; Albuquerque Andrade de Matos, Carlos Adriano; Marques, Nuno; Marreiros, Ana; Nzwalo, Hipólito; Pais, Sandra; Palmeirim, Isabel; Simãoa, Sónia; Joaquim, Natércia; Miranda, Rui; Pêgas, António; Raposo, Daniela Marques; Sardo, Ana; Araújo, Inês; Nóbrega, Clévio; Castelo-Branco, Pedro; Bragança, JoséHuman induced pluripotent stem cells (hiPSCs) hold promises to model and understand human diseases, including those associated with ageing. Here, we describe ABCRIi001-A, a hiPSC line generated from peripheral blood mononuclear cells (PBMCs) of a 79-year-old female enrolled in a study for development of an ageing score (ALFA Score). PBMCs were reprogrammed using three Sendai virus-based reprogramming vectors (hKOS, hc-Myc, and hKlf4). ABCRIi001-A showed normal morphology and karyotype, viral clearance, absence of genomic aberrations, and their pluripotency was confirmed by expression of pluripotency-related markers and their ability to differentiate into the three germ layers. ABCRIi001-A is valuable for ageing-related studies.
- Generation and cardiac differentiation of a human induced pluripotent stem cell line UALGi002-A from a female patient with Left-Ventricular Noncompaction CardiomyopathyPublication . Calado, Sofia; Bento, Dina; Marques, Nuno; Bragança, JoséLeft Ventricular Noncompaction Cardiomyopathy (LVNC) is characterized by abnormal number and prominence of trabeculations of the left ventricle of the heart. Although LVNC has been associated with mutations in several genes encoding for transcriptional regulators, ion channels, sarcomeric and mitochondrial proteins, approximately 60% of LVNC patients do not present these genetic alterations. Here, we describe an induced pluripotent stem cell (hiPSC) line (UALGi002-A) originated from a LVNC female patient (LVNC-hiPSC) who does not present any previously known mutations associated to LVNC. The LVNC-hiPSC exhibited full pluripotency and differentiation potential and retained a normal karyotype after reprogramming. Moreover, the LVNC-hiPSC differentiated into contracting cardiomyocytes. This cellular model will be useful to study the molecular, genetic and functional aspects of LVNC in vitro.
- Generation and characterization of two isogenic induced pluripotent stem cell lines from a young female with microcephaly carrying a compound heterozygous mutation in BUB1 genePublication . Ferreira, Anita; Calado, Sofia; Jorge, Xavier; Lange, Job de; Carvalhal, SaraMutations in the Budding uninhibited by benzimidazoles (BUB1) gene were recently associated with neurodevelopmental disorders (Carvalhal et al., 2022). Here, we describe the generation and characterization of two induced pluripotent stem cells (iPSC) clones from a young female with microcephaly. The patient carried two variants in the BUBfibroblast gene (OMIM # 602452), one (c.[2197dupG]; p.[D732fs*11]) paternally inherited and one (c.[2625+1G>A]; p.[V822_L875del] maternally inherited. The generated clones exhibit a normal karyotype (UALGi003-A) and trisomy 8 (UALGi003-B), express pluripotency markers, and differentiate into trilineage cells in vitro. These cell lines can be used to study neurodevelopment and the processes of chromosome segregation.
- Generation of a human induced pluripotent stem cell line (UALGi001-A) from a patient with Left-Ventricular Noncompaction CardiomyopathyPublication . Calado, Sofia; Bento, Dina; Justino, David; Mendes-Silva, Leonardo; Marques, Nuno; Bragança, JoséLeft Ventricular Noncompaction Cardiomyopathy (LVNC) is characterized by excessive trabeculation of the left ventricle. To date, mutations in more than 40 genes have been associated with LVNC, however the exact mechanisms underlying the disease remain unknown. Here, we describe an induced pluripotent stem cell (iPSC) line (UALGi001-A) from a LVNC patient (LVNC-iPSC) that does not present mutations in the genes most commonly associated with the disease (van Waning et al., 2019). The LVNC-iPSC exhibited full pluripotency and differentiation potential, and retained a normal karyotype after reprogramming. This in vitro cellular model will be useful to study the molecular, genetic and functional aspects of LVNC.
- GLUT1 activity contributes to the impairment of PEDF secretion by the RPEPublication . Calado, Sofia; Alves, Liliana S.; S, Simão; Silva, Gabriela A.Purpose: In this study, we aimed to understand whether glucose transporter 1 (GLUT1) activity affects the secretion capacity of antiangiogenic factor pigment epithelium-derived factor (PEDF) by the RPE cells, thus explaining the reduction in PEDF levels observed in patients with diabetic retinopathy (DR).Methods: Analysis of GLUT1 expression, localization, and function was performed in vitro in RPE cells (D407) cultured with different glucose concentrations, corresponding to non-diabetic (5 mM of glucose) and diabetic (25 mM of glucose) conditions, further subjected to normoxia or hypoxia. The expression of PEDF was also evaluated in the secretome of the cells cultured in these conditions. Analysis of GLUT1 and PEDF expression was also performed in vivo in the RPE of Ins2(Akita) diabetic mice and age-matched wild-type (WT) controls.Results: We observed an increase in GLUT1 under hypoxia in a glucose-dependent manner, which we found to be directly associated with the translocation and stabilization of GLUT1 in the cell membrane. This stabilization led to an increase in glucose uptake by RPE cells. This increase was followed by a decrease in PEDF expression in RPE cells cultured in conditions that simulated DR. Compared with non-diabetic WT mice, the RPE of Ins2Akita mice showed increased GLUT1 overexpression with a concomitant decrease in PEDF expression.Conclusions: Collectively, our data show that expression of GLUT1 is stimulated by hyperglycemia and low oxygen supply, and this overexpression was associated with increased activity of GLUT1 in the cell membrane that contributes to the impairment of the RPE secretory function of PEDF.