CRIS

Permanent URI for this communityhttps://investigadores.udd.cl/handle/123456789/1

Browse

Search Results

Now showing 1 - 10 of 72

Some of the metrics are blocked by your
consent settings
TGFβ links EBV to multisystem inflammatory syndrome in children
(Springer Science and Business Media LLC, 2025-03-12)
Carl Christoph Goetzke
;
Mona Massoud
;
Stefan Frischbutter
;
Gabriela Maria Guerra
;
Marta Ferreira-Gomes
<jats:title>Abstract</jats:title> <jats:p>In a subset of children and adolescents, SARS-CoV-2 infection induces a severe acute hyperinflammatory shock<jats:sup>1</jats:sup> termed multisystem inflammatory syndrome in children (MIS-C) at four to eight weeks after infection. MIS-C is characterized by a specific T cell expansion<jats:sup>2</jats:sup> and systemic hyperinflammation<jats:sup>3</jats:sup>. The pathogenesis of MIS-C remains largely unknown. Here we show that acute MIS-C is characterized by impaired reactivation of virus-reactive memory T cells, which depends on increased serum levels of the cytokine TGFβ resembling those that occur during severe COVID-19 (refs. <jats:sup>4,5</jats:sup>). This functional impairment in T cell reactivity is accompanied by the presence of TGFβ-response signatures in T cells, B cells and monocytes along with reduced antigen-presentation capabilities of monocytes, and can be reversed by blocking TGFβ. Furthermore, T cell receptor repertoires of patients with MIS-C exhibit expansion of T cells expressing TCRVβ21.3, resembling Epstein–Barr virus (EBV)-reactive T cell clones capable of eliminating EBV-infected B cells. Additionally, serum TGFβ in patients with MIS-C can trigger EBV reactivation, which is reversible with TGFβ blockade. Clinically, the TGFβ-induced defect in T cell reactivity correlates with a higher EBV seroprevalence in patients with MIS-C compared with age-matched controls, along with the occurrence of EBV reactivation. Our findings establish a connection between SARS-CoV-2 infection and COVID-19 sequelae in children, in which impaired T cell cytotoxicity triggered by TGFβ overproduction leads to EBV reactivation and subsequent hyperinflammation.</jats:p>
Scopus© Citations 4 2
Some of the metrics are blocked by your
consent settings
A Novel Homozygous 9385 bp Deletion in the FERMT1 (KIND1) Gene in a Malaysian Family with Kindler Epidermolysis bullosa and a Review of Large Deletions
(MDPI AG, 2025-04-29)
Alfred Klausegger
;
Fabian Leditzky
;
Susanne Krämer
;
PALISSON ETCHARREN, FRANCIS
;
YUBERO GONCALVEZ, MARIA JOAO
Kindler Epidermolysis bullosa (KEB; OMIM 173650) is a rare autosomal recessive genodermatosis characterized by bullous poikiloderma and photosensitivity. Additional presentations include blistering, poor wound healing, skin atrophy, and increased risk of skin cancer. Most cases of KEB result from aberrations in the FERMT1 (Fermitin family member 1) gene encoding kindlin-1 and include nonsense, frameshift, splicing, and missense variants. Large deletion variants have been reported in nine cases to date. Most variants are predicted to lead to premature termination of translation and to loss of kindlin-1 function. In this study, we report on a 33-year-old male patient who presented with typical clinical manifestations of KEB. As routine molecular testing failed to obtain a diagnosis, Next Generation Sequencing (NGS) of an Epidermolysis Bullosa (EB)-specific panel was carried out followed by the determination of the deletion breakpoints and verification at the mRNA and protein levels. This approach revealed a new large homozygous deletion of ~9.4 kb in the FERMT1 gene involving exons 7 to 9. Finally, we performed a literature review on large FERMT1 deletions. The deletion is predicted to skip exons 7 to 9 within the mRNA, which results in a frameshift. The patient’s phenotype is likely caused by the resulting truncated and non-functioning protein. Our report further enriches the spectrum of FERMT1 gene variants to improve genotype–phenotype correlations.
1
Some of the metrics are blocked by your
consent settings
New Dermoscopy Pattern in Nevus‐Associated Melanomas
(Wiley, 2025-04-19)
Nelson Lobos‐Guede
;
Dan Hartmann
;
Valentina Darlic
;
Cristina Carrera
;
Llucia Alos
Melanomas can appear de novo or in association with a pre‐existing nevus. The association of melanomas with pre‐existing nevi and its role as a melanoma precursor is a controversial issue. Dermoscopy can increase melanoma's diagnostic accuracy and help us suspect nevus‐associated melanomas (NAM). Differentiating NAMs clinically and dermoscopically can be challenging. There are few published studies so far describing dermoscopic features of NAM that have differentiated from <jats:italic>de novo</jats:italic> melanomas, such as multi‐component pattern, multifocal pigmentation, atypical pigment network, regression structures, negative pigment network, irregular globules, and streaks. Here, we report four acquired compound NAMs showing a starburst pattern (SP) within the lesion. No publications have reported NAMs with melanoma components in the form of SP arising within the center of the lesion. Therefore, when faced with a compound or intradermal nevus with incipient central reticulated pigmentation, especially if there is no history of trauma or previous surgery, we must pay alert to the possibility of an early development of melanoma.
2
Some of the metrics are blocked by your
consent settings
Multiomics dissection of human RAG deficiency reveals distinctive patterns of immune dysregulation but a common inflammatory signature
(American Association for the Advancement of Science (AAAS), 2025-01-10)
Marita Bosticardo
;
Kerry Dobbs
;
Ottavia M. Delmonte
;
Andrew J. Martins
;
Francesca Pala
<jats:p> Human recombination-activating gene (RAG) deficiency can manifest with distinct clinical and immunological phenotypes. By applying a multiomics approach to a large group of <jats:italic>RAG</jats:italic> -mutated patients, we aimed at characterizing the immunopathology associated with each phenotype. Although defective T and B cell development is common to all phenotypes, patients with hypomorphic <jats:italic>RAG</jats:italic> variants can generate T and B cells with signatures of immune dysregulation and produce autoantibodies to a broad range of self-antigens, including type I interferons. T helper 2 (T <jats:sub>H</jats:sub> 2) cell skewing and a prominent inflammatory signature characterize Omenn syndrome, whereas more hypomorphic forms of RAG deficiency are associated with a type 1 immune profile both in blood and tissues. We used cellular indexing of transcriptomes and epitopes by sequencing (CITE-seq) analysis to define the cell lineage–specific contribution to the immunopathology of the distinct RAG phenotypes. These insights may help improve the diagnosis and clinical management of the various forms of the disease. </jats:p>
Scopus© Citations 2 1
Some of the metrics are blocked by your
consent settings
MET Exon 14 Skipping and Novel Actionable Variants: Diagnostic and Therapeutic Implications in Latin American Non-Small-Cell Lung Cancer Patients
(MDPI AG, 2024-12-22)
RIVAS VERA, SOLANGE VERÓNICA
;
Romina V. Sepúlveda
;
TAPIA DUFEY, JUAN IGNACIO
;
Catalina Estay
;
Vicente Soto
<jats:p>Targeted therapy indications for actionable variants in non-small-cell lung cancer (NSCLC) have primarily been studied in Caucasian populations, with limited data on Latin American patients. This study utilized a 52-genes next-generation sequencing (NGS) panel to analyze 1560 tumor biopsies from NSCLC patients in Chile, Brazil, and Peru. The RNA sequencing reads and DNA coverage were correlated to improve the detection of the actionable MET exon 14 skipping variant (METex14). The pathogenicity of MET variants of uncertain significance (VUSs) was assessed using bioinformatic methods, based on their predicted driver potential. The effects of the predicted drivers VUS T992I and H1094Y on c-MET signaling activation, proliferation, and migration were evaluated in HEK293T, BEAS-2B, and H1993 cell lines. Subsequently, c-Met inhibitors were tested in 2D and 3D cell cultures, and drug affinity was determined using 3D structure simulations. The prevalence of MET variants in the South American cohort was 8%, and RNA-based diagnosis detected 27% more cases of METex14 than DNA-based methods. Notably, 20% of METex14 cases with RNA reads below the detection threshold were confirmed using DNA analysis. The novel actionable T992I and H1094Y variants induced proliferation and migration through c-Met/Akt signaling. Both variants showed sensitivity to crizotinib and savolitinib, but the H1094Y variant exhibited reduced sensitivity to capmatinib. These findings highlight the importance of RNA-based METex14 diagnosis and reveal the drug sensitivity profiles of novel actionable MET variants from an understudied patient population.</jats:p>
Scopus© Citations 4 8
Some of the metrics are blocked by your
consent settings
Kinin Receptors B1 and B2 Mediate Breast Cancer Cell Migration and Invasion by Activating the FAK-Src Axis
(2024)
Felipe González-Turén
;
Lorena Lobos-González
;
Alexander Riquelme-Herrera
;
Andrés Ibacache
;
Luis Meza Ulloa
Kinin receptors B1 and B2 are involved in migration and invasion in gastric, glioma, and cervical cancer cells, among others. However, the role of kinin receptors in breast cancer cells has been poorly studied. We aimed to reveal the impact of B1 and B2 receptors on migration and invasion in breast cancer cells and demonstrate their capacity to modulate in vivo tumor growth. MDA-MB-231, MCF-7, and T47D cells treated with Lys-des[Arg9]bradykinin (LDBK) or bradykinin (BK) were used to evaluate migration and invasion. Des-[Arg9]-Leu8-BK and HOE-140 were used as antagonists for the B1 and B2 receptors. MDA-MB-231 cells incubated or not with antagonists were subcutaneously inoculated in BALBc NOD/SCID mice to evaluate tumor growth. LDBK and BK treatment significantly increased migration and invasion in breast cancer cells, effects that were negated when antagonists were used. The use of antagonists in vivo inhibited tumor growth. Moreover, the migration and invasion induced by kinins in breast cancer cells were inhibited when focal adhesion kinase (FAK) and Src inhibitors were used. The novelty revealed in our work is that B1 and B2 receptors activated by LDBK and BK induce migration and invasion in breast cancer cells via a mechanism that involves the FAK–Src signaling pathway, and the antagonism of both receptors in vivo impairs breast tumor growth.
3Scopus© Citations 3
Some of the metrics are blocked by your
consent settings
Prostaglandin E2 Exposure Disrupts E-Cadherin/Caveolin-1-Mediated Tumor Suppression to Favor Caveolin-1-Enhanced Migration, Invasion, and Metastasis in Melanoma Models
(2023)
Lorena Lobos-González
;
Lorena Oróstica
;
Natalia Díaz-Valdivia
;
Victoria Rojas-Celis
;
America Campos
<jats:p>Caveolin-1 (CAV1) is a membrane-bound protein that suppresses tumor development yet also promotes metastasis. E-cadherin is important in CAV1-dependent tumor suppression and prevents CAV1-enhanced lung metastasis. Here, we used murine B16F10 and human A375 melanoma cells with low levels of endogenous CAV1 and E-cadherin to unravel how co-expression of E-cadherin modulates CAV1 function in vitro and in vivo in WT C57BL/6 or Rag−/− immunodeficient mice and how a pro-inflammatory environment generated by treating cells with prostaglandin E2 (PGE2) alters CAV1 function in the presence of E-cadherin. CAV1 expression augmented migration, invasion, and metastasis of melanoma cells, and these effects were abolished via transient co-expression of E-cadherin. Importantly, exposure of cells to PGE2 reverted the effects of E-cadherin expression and increased CAV1 phosphorylation on tyrosine-14 and metastasis. Moreover, PGE2 administration blocked the ability of the CAV1/E-cadherin complex to prevent tumor formation. Therefore, our results support the notion that PGE2 can override the tumor suppressor potential of the E-cadherin/CAV1 complex and that CAV1 released from the complex is phosphorylated on tyrosine-14 and promotes migration/invasion/metastasis. These observations provide direct evidence showing how a pro-inflammatory environment caused here via PGE2 administration can convert a potent tumor suppressor complex into a promoter of malignant cell behavior.</jats:p>
1Scopus© Citations 5
Some of the metrics are blocked by your
consent settings
Outcomes of hematopoietic stem cell gene therapy for Wiskott-Aldrich syndrome
(2023)
Roxane Labrosse
;
Julia I. Chu
;
Myriam A. Armant
;
John K. Everett
;
Danilo Pellin
<jats:title>Abstract</jats:title> <jats:p>Wiskott-Aldrich syndrome (WAS) is a rare X-linked disorder characterized by combined immunodeficiency, eczema, microthrombocytopenia, autoimmunity, and lymphoid malignancies. Gene therapy (GT) to modify autologous CD34+ cells is an emerging alternative treatment with advantages over standard allogeneic hematopoietic stem cell transplantation for patients who lack well-matched donors, avoiding graft-versus-host-disease. We report the outcomes of a phase 1/2 clinical trial in which 5 patients with severe WAS underwent GT using a self-inactivating lentiviral vector expressing the human WAS complementary DNA under the control of a 1.6-kB fragment of the autologous promoter after busulfan and fludarabine conditioning. All patients were alive and well with sustained multilineage vector gene marking (median follow-up: 7.6 years). Clinical improvement of eczema, infections, and bleeding diathesis was universal. Immune function was consistently improved despite subphysiologic levels of transgenic WAS protein expression. Improvements in platelet count and cytoskeletal function in myeloid cells were most prominent in patients with high vector copy number in the transduced product. Two patients with a history of autoimmunity had flares of autoimmunity after GT, despite similar percentages of WAS protein–expressing cells and gene marking to those without autoimmunity. Patients with flares of autoimmunity demonstrated poor numerical recovery of T cells and regulatory T cells (Tregs), interleukin-10–producing regulatory B cells (Bregs), and transitional B cells. Thus, recovery of the Breg compartment, along with Tregs appears to be protective against development of autoimmunity after GT. These results indicate that clinical and laboratory manifestations of WAS are improved with GT with an acceptable safety profile. This trial is registered at clinicaltrials.gov as #NCT01410825.</jats:p>
12Scopus© Citations 30
Some of the metrics are blocked by your
consent settings
The Role of MicroRNAs in Breast Cancer and the Challenges of Their Clinical Application
(2023)
Juan P. Muñoz
;
Pablo Pérez-Moreno
;
Yasmín Pérez
;
Gloria M. Calaf
<jats:p>MicroRNAs (miRNAs) constitute a subclass of non-coding RNAs that exert substantial influence on gene-expression regulation. Their tightly controlled expression plays a pivotal role in various cellular processes, while their dysregulation has been implicated in numerous pathological conditions, including cancer. Among cancers affecting women, breast cancer (BC) is the most prevalent malignant tumor. Extensive investigations have demonstrated distinct expression patterns of miRNAs in normal and malignant breast cells. Consequently, these findings have prompted research efforts towards leveraging miRNAs as diagnostic tools and the development of therapeutic strategies. The aim of this review is to describe the role of miRNAs in BC. We discuss the identification of oncogenic, tumor suppressor and metastatic miRNAs among BC cells, and their impact on tumor progression. We describe the potential of miRNAs as diagnostic and prognostic biomarkers for BC, as well as their role as promising therapeutic targets. Finally, we evaluate the current use of artificial intelligence tools for miRNA analysis and the challenges faced by these new biomedical approaches in its clinical application. The insights presented in this review underscore the promising prospects of utilizing miRNAs as innovative diagnostic, prognostic, and therapeutic tools for the management of BC.</jats:p>
Scopus© Citations 52
Some of the metrics are blocked by your
consent settings
Factors influencing neutralizing antibody response to the original SARS-CoV-2 virus and the Omicron variant in a high vaccination coverage country, a population-based study
(2023)
HORMAZABAL CASTILLO, JUAN PATRICIO
;
Loreto Nuñez-Franz
;
RUBILAR RAMIREZ, PAOLA ANDREA
;
APABLAZA SALINAS, MAURICIO IVÁN
;
VIAL COX, MARIA CECILIA
Scopus© Citations 3 2

CRIS

Browse

Filters

Settings

Sort By

Results per page

Search Results