Biology subjects

Medina, M. A.

Publications and source records attributed to Medina, M. A..

5 recordsLinked to original sources

bioRxiv2026

Strategies for the modulation of mitochondrial metabolism and activity in the treatment of neurodegenerative diseases: A systematic review and meta-analysis.

Neurodegenerative diseases (NDDs) are currently raising their prevalences and new preclinical low-cost investigations of drug design are urging. NDDs encompass a wide range of disorders, including Alzheimers, Parkinsons, ALS and others, many of which share mitochondrial dysfunction as a common pathological feature. As such, targeting mitochondrial metabolism has emerged as a promising therapeutic strategy. However, while rodent models are widely used in NDD research, they are costly and time-consuming, raising the need to consider other alternatives to accelerate the search for novel therapies. In this line, zebrafish (Danio rerio) have gained outstanding popularity as a valuable option. This systematic review aims to provide an extensive overview about the current strategies that use zebrafish assays to investigate modulations of mitochondrial function as new therapies against NDDs. The review was performed following an electronic search of different databases (PubMed, Embase, Scopus and Web of Science) after the PRISMA procedure. Articles published in the English language were identified and screened based on the keywords used: mitochondrial metabolism, therapy, neurodegenerative diseases and zebrafish. Following 176 entries, exclusion criteria reduced the record to 34 final studies. Overall, we found that these studies investigate 37 compounds: 24 natural, 6 semisynthetic, 5 synthetic and 2 compounds of not-determined origin; to ameliorate 9 prevalent diseases: ARSACS, Alzheimers, Parkinsons, Huntingtons diseases, Leigh and Wolfram syndromes, Amyotrophic lateral sclerosis, Limb - girdle muscular dystrophy 2G and hyperglycemia-associated amnesia. Additionally, a meta-analysis of these compounds and their gene interactions provides insights into their mechanisms of action and advances our understanding of NDDs, and furnishes us with a powerful tool to predictive potential new drugs or to repurpose existing ones. To conclude, this systematic review suggests that zebrafish have become an effective model for screening potential drugs for NDDs with symptomatology difficult to replicate in rodent models. Moreover, the use of computational tools is also emphasized as a promising strategy to guide therapeutic discovery more efficiently, reducing both time and costs, in developing treatments for NDDs. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=102 SRC="FIGDIR/small/710294v1_ufig1.gif" ALT="Figure 1"> View larger version (30K): org.highwire.dtl.DTLVardef@18893a1org.highwire.dtl.DTLVardef@1943a12org.highwire.dtl.DTLVardef@709146org.highwire.dtl.DTLVardef@51a488_HPS_FORMAT_FIGEXP M_FIG C_FIG

neuroscience↗

bioRxiv2025

Dynamic Tracking and Single-Cell Analysis of Starvation-Induced Autophagic Responses in Breast Cancer Cells

Nutrient stress induces dynamic and heterogeneous cellular responses that are often reduced to population averages or endpoint measurements. AURORA is a longitudinal single-cell phenotyping framework integrating high-content time-lapse imaging, trajectory-aware quality control, multi-compartment morphology, reference phenotypic states, and cross-cell-line aggregation of state-occupancy behaviors. AURORA is applied to MCF-7, MDA-MB-231, A-549, and HT-1080 cancer cells during 4 h exposure to Earle's balanced salt solution (EBSS). Population-level Total Autophagy shows sustained EBSS-associated elevation in MCF-7, A-549, and HT-1080, but a stronger early response followed by attenuation in MDA-MB-231. Longitudinal analysis shows that these averages arise from cell-line- and time-dependent changes in single-cell distributions rather than uniform displacement. Feature-level analysis further identifies distinct combinations of nuclear, whole-cell, and autophagosome-associated organization, compactness, and shape in each model. Projection of EBSS-treated cells into Complete-defined phenotypic landscapes reveals line-specific redistribution among reference states. Despite this specificity, dominant state-occupancy signatures converge into six recurrent higher-order programs, linking different cellular routes to partially shared remodeling architectures. Because DAPGreen is not paired with a flux inhibitor or ratiometric reporter, these findings describe an autophagy-associated imaging phenotype rather than autophagic flux. AURORA therefore distinguishes population-average change from heterogeneous single-cell adaptation during dynamic stress responses.

cancer biology↗

bioRxiv2024

Longitudinal transcriptional changes reveal genes from the natural killer cell-mediated cytotoxicity pathway as critical players underlying COVID-19 progression

Patients present a wide range of clinical severities in response SARS-CoV-2 infection, but the underlying molecular and cellular reasons why clinical outcomes vary so greatly within the population remains unknown. Here, we report that negative clinical outcomes in severely ill patients were associated with divergent RNA transcriptome profiles in peripheral immune cells compared with mild cases during the first weeks after disease onset. Protein-protein interaction analysis indicated that early-responding cytotoxic NK cells were associated with an effective clearance of the virus and a less severe outcome. This innate immune response was associated with the activation of select cytokine-cytokine receptor pathways and robust Th1/Th2 cell differentiation profiles. In contrast, severely ill patients exhibited a dysregulation between innate and adaptive responses affiliated with divergent Th1/Th2 profiles and negative outcomes. This knowledge forms the basis of clinical triage that may be used to preemptively detect high-risk patients before life-threatening outcomes ensue. Highlights- Mild COVID-19 patients displayed an early transcriptional commitment with NK cell function, whereas severe patients do so with neutrophil function. - The identified co-expressed genes give insights into a coordinated transcriptional program of NK cell cytotoxic activity being associated with mild patients. - Key checkpoints of NK cell cytotoxicity that were enriched in mild patients include: KLRD1, CD247, and IFNG. - The early innate immune response related to NK cells connects with the Th1/Th2 adaptive immune responses, supporting their relevance in COVID-19 progression.

immunology↗

bioRxiv2021

Nanoscale details of mitochondrial fission revealed by cryo-electron tomography

Mitochondrial fission is required for proper segregation during cell division, quality control, and cellular homeostasis (metabolism and energy production). Despite its importance, models of the process remain speculative. Here we apply cryogenic electron tomography to image the nanoscale architecture of mitochondrial fission in mammalian cells. We find that constriction of the inner and outer membranes is coordinated, suggesting that force on both membranes is applied externally. While we observe ER at constriction sites, it did not encircle constrictions. Instead, we find long bundles of both unbranched actin and septin filaments enriched at constrictions. Actin bundles align with the central region of division bridges and septin bundles with the necks on either side. Septin bundles appear to guide microtubules to constriction sites, suggesting, along with autolysosomes observed in the vicinity, a pathway for mitophagy. Together, our results rule out several existing models for mitochondrial fission and provide empirical parameters to inform the development of realistic coarse-grained models in the future.

cell biology↗

bioRxiv2021

The anti-angiogenic compound dimethyl fumarate inhibits the serine synthesis pathway and increases glycolysis in endothelial cells

A pathological and persistent angiogenesis is observed in several diseases like retinopathies, diabetes, psoriasis and cancer. Dimethyl fumarate, an ester from the Krebs cycle intermediate fumarate, is approved as a drug for the treatment of psoriasis and multiple sclerosis, and its anti-angiogenic activity has been reported in vitro and in vivo. However, it is not known whether dimethyl fumarate is able to modulate endothelial cell metabolism, considered an essential feature for the angiogenic switch. By means of different experimental approximations, including proteomics, isotope tracing and metabolomics experimental approaches, in this work we studied the possible role of dimethyl fumarate in endothelial cell energetic metabolism. We demonstrate for the first time that dimethyl fumarate promotes glycolysis and diminishes cell respiration, which could be a consequence of a down-regulation of serine and glycine synthesis through inhibition of PHGDH activity in endothelial cells. This new target can open a new field of study regarding the mechanism of action of dimethyl fumarate.

biochemistry↗