Biology subjects

Ortega, Z.

Publications and source records attributed to Ortega, Z..

4 recordsLinked to original sources

bioRxiv2026

Syndecan-1 Promotes Alveolar Type 2 Epithelial Cell Senescence during Lung Fibrosis.

Idiopathic pulmonary fibrosis (IPF) is an age-related, progressive, and fatal interstitial lung disease for which effective therapies remain limited. Alveolar type 2 (AT2) epithelial cells serve as facultative stem cells essential for alveolar repair; however, AT2 cell senescence disrupts epithelial regeneration and contributes to fibrotic remodeling in IPF. Syndecan-1 is a transmembrane heparan sulfate proteoglycan predominantly expressed by lung epithelial cells, but its role in AT2 dysfunction during fibrosis is poorly defined. Here, we demonstrate that syndecan-1 is robustly upregulated in AT2 cells in IPF and other fibrotic lung diseases, as well as in murine bleomycin-induced lung fibrosis. Syndecan-1 expression was further enhanced with aging and associated with increased fibrotic burden in aged mice. Using integrated human transcriptomic analyses, mouse genetic models, and epithelial cell-based systems, we show that excess syndecan-1 promotes cell-autonomous epithelial senescence and impairs AT2 progenitor function. Elevated syndecan-1 reduced AT2 renewal capacity, disrupted differentiation, and diminished surfactant protein C level, whereas genetic loss of syndecan-1 attenuated senescence and preserved epithelial function following injury. Together, these findings identify syndecan-1 as a critical epithelial regulator of AT2 senescence and maladaptive repair in pulmonary fibrosis and support targeting syndecan-1-driven epithelial dysfunction as a potential therapeutic strategy.

cell biology↗

bioRxiv2024

Seasonal behavioral patterns of the Caqueta titi monkey (Plecturocebus caquetensis)

The Caqueta titi monkey (Plecturocebus caquetensis) is Critically Endangered (CR) due to habitat destruction associated with extensive livestock ranching and farming. But unfortunately, information on the ecology and behavior of the species is scarce. Here we describe seasonal behavioral patterns and home range size of P. caquetensis in a 23-ha forest fragment in Colombia. In 2013, we collected focal animal behavioral data of a group of seven individuals of P. caquetensis. Overall, titi monkeys spent 33% of their time feeding, 4% locomotion, 42% resting, and 21% engaging in social interactions, such as grooming and vocalizations. However, the activity budgets differed substantially between seasons. In the dry season titi monkeys invested significantly more time feeding than in the rainy season, when they spent more time moving. They invested a similar amount of time in social interactions in both seasons. Home range size was larger during the rainy season; but the core areas of the home ranges had a similar size and they overlapped across seasons, suggesting the overall importance of this area for titi monkeys. These findings constitute the first study on the seasonal ecology and home range of this Critically Endangered species, and it identifies a priority local conservation area.

ecology↗

bioRxiv2020

Perch selection of three species of kingfishers at the Pantanal wetland, Brazil

Animal movement and behavior depend on the distribution of resources on the habitat. Therefore, individual animals are constantly making decisions on resource selection based on different attributes of the resource or its associated environmental variables. For fish-eating birds as kingfishers, selecting a suitable perch can report many benefits, as improving fishing success or reducing predation risk. Nowadays, not only natural structures, as branches, are available for birds to perch but also artificial ones, as electric lines. Thus, we aimed to understand which variables drive kingfishers perch selection, including the potential effect of its anthropic origin. We studied perch selection of three species of kingfishers inhabiting the Pantanal of Miranda of Brazil: Megaceryle torquata, Chloroceryle amazona and Chloroceryle americana. They feed in temporary ponds that are rich in trophic resources, where they have both natural and artificial potential perches. We hypothesized that artificial perches could be strongly selected, as they are more stable than natural ones and go through the ponds, providing a long surface to select optimal conditions. We assessed how kingfishers are selecting perches based on four ecologically relevant traits: (1) being artificial or natural, perch height, (3) distance to the water, and (4) plant cover. We used a resource selection function (RSF) approach to quantify the effect of these variables in the probability of presence of kingfishers. The artificial origin of a perch was independent of the probability of selection for the three species. Furthermore, birds acted randomly to the other studied variables, except for individuals of C. amazona, which select higher perches, above 3.20 m. We discuss the implications of these results for understanding the behavioral ecology and use of space of neotropical kingfishers, and how this affects their vulnerability to human habitat alterations. GRAPHICAL ABSTRACT O_FIG O_LINKSMALLFIG WIDTH=194 HEIGHT=200 SRC="FIGDIR/small/306027v1_ufig1.gif" ALT="Figure 1"> View larger version (58K): org.highwire.dtl.DTLVardef@6bc8d1org.highwire.dtl.DTLVardef@4d4d0dorg.highwire.dtl.DTLVardef@fdb9aborg.highwire.dtl.DTLVardef@1a88b15_HPS_FORMAT_FIGEXP M_FIG C_FIG

ecology↗

bioRxiv2020

Harlequin Frogs (Lysapsus) prefer mild places to park

Temperature affects most aspects of ectotherms life history, including physiology and behavior. Studying thermal sensitivity of jumping performance in frogs can help understanding the influence of temperature on different aspects of frog life. Still, studies on the effects of temperature on amphibians are commonly carried out on terrestrial and tree species, creating a gap for aquatic species. We experimentally tested the thermal sensitivity of jumping performance of the Uruguay Harlequin Frog, Lysapsus limellum, assessing three measures: response time, distance of first jump, and total distance travelled. We hypothesized that individuals submitted to extreme temperatures would increase response time, decrease first jump distance, and increase total jump distance. We used an arena with a gradient of air temperature (Ta) ranging from 20 to 40 {degrees}C. We placed frogs at different Ta and stimulated them to jump. Then, we analysed the influence of Ta on the three estimates of jumping performance, using generalized additive models. We found that temperature affected all three measurements of jumping performance, but some relationships were stronger than others. Extreme temperatures increased response time, reduced first jump distance, and increased total distance. The effect was weaker for response time and first jump distance, but substantially stronger for total distance jumped. Although individuals under extreme temperatures experience a reduced jumping performance, they travelled longer distances to find areas with milder temperatures. Thus, we showed that L. limellum thermoregulates by means of behavior, moving through places at different thermal conditions. Additionally, benefits of displacing to thermally suitable places -in terms of enhanced jumping performance-are bigger than the costs of jumping at reduced locomotor performance, at least under experimental conditions. Our results can help understand how climate change affects the locomotor performance of Neotropical amphibians.

ecology↗