Biology subjects

Perez-Cruz, C.

Publications and source records attributed to Perez-Cruz, C..

3 recordsLinked to original sources

bioRxiv2024

Astroglial atrophy associates with loss of nuclear S100A10 in the hippocampus of aged male tree shrews

Astrocytes are glial cells that participate in multiple physiological functions, such as protecting neurons against all types of damage. However, astrocytes develop morphological alterations during aging, such as decreased length, volume, and branch points of their processes, also known as astrocytic atrophy. Until now, the exact mechanism associated with the onset of atrophy is unknown. Tree shrew (Tupaia belangeri) is a long-lived animal from the Scadentia order that develops several age-dependent brain alterations. In this study, we analyzed the morphology of GFAP+ astrocytes in the hippocampal region of adult, old, and aged male tree shrews. Aged animals presented more GFAP+ astrocytes in the proximal subiculum, CA3, and CA2-CA1 subregions than younger animals, being significantly higher only in CA3. However, in aged subjects, the number of atrophic astrocytes was significantly higher in the dentate gyrus and CA2 subregion compared to old animals. Interestingly, in the proximal subiculum, astrocytes had a reduced arborization at all ages evaluated. S100A10, a protein overexpressed by neuroprotective-type astrocytes, was mainly found in the nucleus of astrocytes of adult and old subjects. However, in old and aged animals, S100A10 was located in the cytoplasmic compartment of atrophic astrocytes. Furthermore, in astrocytes of aged tree shrews, cytoplasmic inclusions of S100A10 colocalized with the nuclear export protein, Crm-1. These results suggest that the transport of S100A10 from the nucleus to the cytoplasmic compartment of astrocytes could be a process related to astroglial atrophy during the aging process in the hippocampus of three shrews.

neuroscience↗

bioRxiv2023

Diversity and biotechnological potential of filamentous fungi isolated from sediments of Basque estuaries

Marine environments harbor a vast diversity of microorganisms, which have developed multiple strategies to adapt to challenging conditions and represent a valuable source for new products such as pigments, enzymes and bioactive compounds. From all microorganisms inhabiting marine environments, fungi have been the least studied, despite their ubiquitous presence and great biotechnological potential. Here, we focused on the isolation and characterization of filamentous fungi from marine sediment samples, which were collected along the Basque coast in Spain. Through phenotypic characterization, we identified isolates potentially able to produce secondary metabolites or grow on minimal culture medium supplemented with recalcitrant algal polysaccharides. Based on this screening, two Sordariomycetes isolates were selected for further analyses through genome sequencing and omics techniques: 1) a Marquandomyces marquandii strain able to stain the culture medium in yellow, indicative of secretion of pigments and secondary metabolites and 2) an Albophoma yamanashiensis strain able to grow in minimal culture medium supplemented with the recalcitrant algal polysaccharide fucoidan. Fungal co-culture experiments suggested an inhibitory effect of the secretome of M. marquandii on fungal growth. Under culture conditions inducing pigment secretion, a set of secondary metabolite gene clusters were differentially expressed, as analysed by RNA-seq. On the other hand, transcriptomic and proteomic experiments on A. yamanashiensis unveiled the enzymatic activities expressed in response to the presence of fucoidan. Overall, our results indicate that the isolated marine fungal strains could serve as a source of new enzymatic activities and secondary metabolites.

microbiology↗

bioRxiv2023

Atrophic astrocytes in aged marmosets present tau hyperphosphorylation, RNA oxidation, and DNA fragmentation

Astrocytes perform multiple essential functions in the brain showing morphological changes. Hypertrophic astrocytes are commonly observed in cognitively healthy aged animals, implying a functional defense mechanism without losing neuronal support. In neurodegenerative diseases, astrocytes show morphological alterations, such as decreased process length and reduced number of branch points, known as astroglial atrophy, with detrimental effects on neuronal cells. The common marmoset (Callithrix jacchus) is a non-human primate that, with age, develops several features that resemble neurodegeneration. In this study, we characterize the morphological alterations in astrocytes of adolescent (mean 1.75 y), adult (mean 5.33 y), old (mean 11.25 y), and aged (mean 16.83 y) male marmosets. We observed a significantly reduced arborization in astrocytes of aged marmosets compared to younger animals in the hippocampus and entorhinal cortex. These astrocytes also show oxidative damage to RNA and increased nuclear pTau (AT100). Astrocytes lacking S100A10 protein show a more severe atrophy and DNA fragmentation. Our results demonstrate the presence of atrophic astrocytes in the brains of aged marmosets.

neuroscience↗