Biology subjects

Marques, R.

Publications and source records attributed to Marques, R..

4 recordsLinked to original sources

bioRxiv2025

A cold-water coral garden with co-occurring Antipathella subpinnata and Dendrophyllia cornigera in the mesophotic zone of the northern Bay of Biscay

Large aggregations of cold-water corals (CWC), often termed CWC gardens, are considered as biodiversity hotspots and recognized as vulnerable marine ecosystems. Their three-dimensional structure creates important habitat complexity, providing refuge, nursery and feeding areas for many deep-water species. Their vulnerability and limited current knowledge highlight the importance of describing the distribution and habitats of these gardens. Using remotely operated vehicles (ROV), we describe an unprecedented large aggregation of the co-occurring black (Antipathella subpinnata) and yellow (Dendrophyllia cornigera) coral gardens in the mesophotic in the northern Bay of Biscay. These distributions acknowledged their latitudinal and bathymetric distributions, in particular for A. subpinnata. Black and yellow corals presented mean densities of 2.0 {+/-} 1.8 colonies.10 m-2 and 1.5 {+/-} 1.3 colonies.10 m-2, respectively. Following the complex topography of this area, they were mostly fixed on hard substrates, particularly in narrow crests close to or surrounded by sand or mud planes. These findings are essential to develop appropriate local spatial management plans, ultimately contributing to the conservation of these vulnerable ecosystems.

ecology↗

bioRxiv2024

Adenine nucleotide translocase 2 silencing promotes metabolic adaptations and anoikis in P19 embryonal carcinoma stem cells

Cancer stem cells (CSCs) are amongst the group of cells constituting tumors, being characterized by their strong self-renewal and survival properties. Cancer cells, CSCs included, are thought to rely mostly on glycolysis, even in the presence of oxygen, which confers them adaptative advantages. Adenine nucleotide translocator 2 (ANT2), responsible for the exchange of ADP and ATP in the mitochondrial inner membrane, has been correlated with a higher glycolytic metabolism and is known to be overexpressed in cancer cells. Using P19 embryonal carcinoma stem cells (P19SCs) as a CSCs model, we inhibit ANT2 translation by using siRNA. ANT2 protein levels were shown to be overexpressed in P19SC when compared to their differentiated counterparts. Furthermore, we showed here that the OXPHOS machinery and mitochondrial membrane potential are compromised after ANT2 depletion, exhibiting a metabolic adaptation towards a less oxidative phenotype. Interestingly, hexokinase II levels were downregulated, which was also accompanied by decreased cell growth, and decreased ability to form spheroids. Our findings underscore ANT2 as a key regulator of metabolic remodeling and cell survival of CSCs, suggesting its potential as a therapeutic target for controlling CSC-driven tumor progression. HighlightsO_LIANT2 silencing promotes cell growth arrest and metabolic remodeling in CSCs. C_LIO_LIANT2 depletion modulates HKII protein levels. C_LIO_LIANT2 induce anoikis resistance in P19SCs C_LI

cancer biology↗

bioRxiv2022

Oxidative stress profiles of lymphoblasts from Amyotrophic Lateral Sclerosis patients with or without known SOD1 Mutations

Amyotrophic lateral sclerosis (ALS) is a fatal and rapidly progressing neurodegenerative disease that affects motor neurons. This disease is associated with oxidative stress especially in mutant superoxide dismutase 1 (mutSOD1) patients. However, less is known for the most prevalent sporadic ALS due to a lack of disease models. Here, we studied oxidative the stress profiles in lymphoblasts from ALS patients with mutSOD1 or unknown (undSOD1) mutations. mutSOD1 and undSOD1 lymphoblasts, as well as sex/age-matched controls (3/group) were obtained from Coriell and divided in 46 years-old-men (C1), 46 years-old-women (C2) or 26/27 years-old-men (C3) cohorts. Growth curves were performed, and several parameters associated with redox homeostasis were evaluated, including SOD activity and expression, general oxidative stress levels, lipid peroxidation, response to oxidative stimulus, glutathione redox cycle, catalase expression, and activity, and Nrf2 transcripts. Pooled (all cohorts) and paired (intra-cohort) statistical analyses were performed, followed by clustering and principal component analyses (PCA). Although a high heterogeneity among lymphoblast redox profiles was found between cohorts, clustering analysis based on 7 parameters with high chi-square ranking (total SOD activity, oxidative stress levels, catalase transcripts, SOD1 protein levels, metabolic response to mM concentrations of tert-butyl hydroperoxide, glutathione reductase activity, and Nrf2 transcript levels) provided a perfect separation between samples from healthy controls and ALS (undSOD1 and mutSOD1), also visualized in the PCA analysis. Our results show distinct redox signatures in lymphoblasts from mutSOD1, undSOD1, and healthy controls that can be used as therapeutic targets for ALS drug development. Highlights Lymphoblasts from ALS patients present altered redox properties Redox profiling evidenced total SOD and glutathione reductase activities, SOD1 protein levels, DCF fluorescence, catalase and Nrf2 transcripts, and tert-butyl hydroperoxide cytotoxicity, as discriminant features for experimental groups. Lymphoblast redox profiles may be helpful for patient stratification and precision medicine

cell biology↗

bioRxiv2021

Effects of climatic change on the potential distribution of Lycoriella species (Diptera: Sciaridae) of economic importance

Lycoriella species (Sciaridae) are responsible for significant economic losses in greenhouse production (e.g. mushrooms, strawberry, and nurseries). Current distributions of species in the genus are restricted to cold-climate countries. Three species of Lycoriella are of particular economic concern in view of their ability to invade across the Northern Hemisphere. We used ecological niche models to determine the potential for range expansion under climate change future scenarios (RCP 4.5 and RCP 8.5) in distributions of these species of Lycoriella. Stable suitability under climate change was a dominant theme in these species; however, potential range increases were noted for key countries (e.g. USA, Brazil, and China). Our results illustrate the potential for range expansion in these species in the Southern Hemisphere, including some of the highest greenhouse production areas in the world.

bioinformatics↗