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Biology subjects

Fernandez, G. J.

Publications and source records attributed to Fernandez, G. J..

4 recordsLinked to original sources

Molecular Analysis and Computational Modeling Reveal Temporally Separable Responses triggered by DENV-Induced Soluble Factors in Endothelial Cells

Dengue virus (DENV) represents a growing global health challenge with billions of people at risk. Severe Dengue (SD), a complication of DENV infection that involves generalized hemorrhage, is driven, at least in part, by endothelial dysfunction. Endothelial dysfunction refers to increased permeability due to inflammation, mechanical injury and/or modification of the genetic program of endothelial cells. Previous work showed that exposure of endothelial cells to conditioned media from DENV-infected cells (CMDV) increased permeability and cellular stiffness, repressed endothelial markers and induced mesenchymal genes. However, the generality, extent, mechanism and ultimate impact of these events in the onset of SD remain elusive. Here, we integrate analysis from in vitro infection of endothelial cells with computational modeling to investigate the key features of CMDV-induced endothelial alterations and their potential impact on endothelial dysfunction. We found that CMDV increased SNA1 and CDH2 expression, while suppressing endothelial genes OCLN and CDH5. Global transcriptomics analysis revealed that CMDV triggered a transient pro-inflammatory response, followed by induction of selected tissue repair genes and matrix remodeling. A non-directed asynchronous network model (NDAM-CMDV) identified IL6 and FN1 as central nodes of DENV-induced endothelial trans-differentiation, providing new molecular insights that predict the evolution of the disease and identify potential therapeutic targets.

cell biology↗

Serum Lipidome as an Early Peripheral Indicator in Familial Alzheimers Disease

Protein biomarkers in biofluids are highly sensitive indicators of prodromal cognitive impairment yet remain limited for primary prevention. Lipids, essential to brain structure and function, offer untapped prognostic value. Here, we identify a lipidomic signature in serum from asymptomatic PSEN1-E280A mutation carriers aged 6-40 years, that differentiate carriers from non-carriers with an AUC 80-90%. Similarly, to symptomatic carriers ([≥]41 years; 93%) and sporadic AD cases (85%), using high-resolution mass spectrometry. Latent profile analysis revealed lipid-based signatures of dementia risk and resilience, shaped by genotype, sex, and APOE isoform, and supported by SIMOA protein biomarkers. Age-dependent dysregulation in sphingolipid and glycolipid metabolism was validated by enzymatic activity (TLC), glial phenotyping (flow cytometry), and gene expression (snRNAseq) in postmortem brain. Ganglioside clearance deficits emerged by age 6-12, followed by proinflammatory shifts from age 13 and p-tau217 elevation by age 20, with greater burden in females and APOE4 carriers. APOE3Ch individuals showed differential salvage pathways of ceramides and gangliosides. These findings position early lipid pathway dysregulation as a biological contributor to Alzheimers pathogenesis and a potential therapeutic target for primary prevention.

neuroscience↗

Transcriptomic analysis of benznidazole-resistant Trypanosoma cruzi clone reveals nitroreductase I-independent resistance mechanisms

The enzyme nitroreductase I (NTRI) has been implicated as the primary gene responsible for resistance to benznidazole (Bz) and nifurtimox in Trypanosoma cruzi. However, Bz-resistant T. cruzi field isolates carrying the wild-type NTR-I enzyme suggest that additional mechanisms independent of this enzyme may contribute to the resistance phenotype. To investigate these alternative mechanisms, in this paper, we pressured a Trypanosoma cruzi clone with a high Bz concentration over several generations to select Bz-resistant clones. Surprisingly, we found a highly drug-resistant clone carrying a wild-type NTRI. However, the knockout of this gene using CRISPR-Cas9 in the sensitive clone showed that NTRI indeed induces resistance to Bz and supports the idea that the resistant one exhibits mechanisms other than NTRI. To explore these new mechanisms, we performed an RNA-seq analysis, which revealed genes involved in metabolic pathways related to oxidative stress, energy metabolism, membrane transporters, DNA repair, and protein synthesis. Our results support the idea that resistance to benznidazole is a multigenic trait. A Deeper understanding of these genes is essential for developing new drugs to treat Chagas disease.

bioinformatics↗

Muscle cell atrophy induced by miR-155-5p reveals molecular targets in skeletal muscle disorders

MicroRNAs are small regulatory molecules that control gene expression. An emerging property of muscle miRNAs is the cooperative regulation of transcriptional and epitranscriptional events controlling muscle phenotype. miR-155 has been related to muscular dystrophy and muscle cell atrophy. However, the function of miR-155 and its molecular targets in muscular dystrophies remain poorly understood. Through in silico and in vitro approaches we identify distinct transcriptional profile of muscle cell atrophy induced by miR-155-5p. The atrophic myotubes changed the expression of 359 genes (166 up-regulated and 193 down-regulated). We reanalyzed muscle transcriptomic data from dystrophin-deficient patients and detected overlap with gene expression patterns in miR-155-treated myotubes. Our analysis indicated that miR-155 regulates a set of transcripts, including Aldh1l, Nek2, Bub1b, Ramp3, Slc16a4, Plce1, Dync1i1, and Nr1h3. Enrichment analysis demonstrates 20 targets involved in metabolism, cell cycle regulation, muscle cell maintenance, and immune system. Moreover, digital cytometry confirmed a significant increase in M2 macrophages, indicating miR-155 effects on immune response in dystrophic muscles. We highlight a critical miR-155 associated with disease-related pathways in skeletal muscle disorders.

genomics↗