José Carlos Santos Teixeira

Abstract Assisted reproductive technologies (ART) use has increased over the past decades. However, reports concerning ART's low efficiency continue to emerge, citing causes related to lower embryo quality and pregnancy rates compared to their in vivo counterparts. One of the setbacks of ART is oxidative stress, which can impair embryo developmental rates. Mitochondrial redox and energetic homeostasis determine both cell survival and death, so mitochondria are a key target for therapeutic intervention strategies. In the present work, our objective was to improve the quality of viable embryos by adding new mitochondria-targeted antioxidants in the embryo culture media to reduce oxidative stress. Two naturally derived antioxidants synthesized by our team, AntiOxBEN2 and AntiOxCIN4, based on hydroxybenzoic and hydroxycinnamic scaffolds, respectively, were studied in two different experimental protocols (here called experiments). The first experiment investigated the effects of the antioxidants on embryo development to determine their optimal concentrations. The first assay of the first experiment focused on the effects of AntiOxCIN4 at concentrations of 1, 2.5, and 10 mu M, while the second assay focused on the effects of AntiOxBEN2 at the same concentrations. A control group without supplementation was run simultaneously. The second experiment aimed to compare the best concentrations of these antioxidant molecules in the embryo culture media and their effect on embryos' resistance to vitrification/warming. In each experiment, the embryos were morphologically evaluated, and the total and viable cell numbers were examined. Reactive oxygen species (ROS) and mitochondrial polarization were also evaluated using specific fluorescent dyes. In experiment 1, an increased embryo quality was identified by using 2.5 mu M AntiOxCIN4 (p = 0.03) and 2.5 mu M AntiOxBEN2 (p = 0.001). Moreover, blastocysts supplemented with 2.5 mu M AntiOxCIN4 had higher viability (p = 0.008), while those supplemented with 2.5 mu M AntiOxBEN2 presented a greater total cell number (p = 0.01). An improvement in embryo cryosurvival following the supplementation during the culture process with either antioxidant was identified in experiment 2, with superior expansion scores after vitrification/warming and culture (2.5 mu M AntiOxCIN4, p = 0.056 and 2.5 mu M AntiOxBEN2, p = 0.059). In conclusion, both AntiOxCIN4 and AntiOxBEN2 had a beneficial effect on embryo development and cryosurvival, suggesting a potential intervention to reduce oxidative stress in assisted reproductive technologies.

Abstract Metabolic dysfunction-associated steatotic liver disease (MASLD) affects approximately 30 % of the global population. Its progression is commonly linked to excessive hepatic fat accumulation, elevated oxidative stress, and impaired mitochondrial function. Given the central role of mitochondria in cellular energy metabolism and redox balance, mitochondria-targeted bioactive molecules have emerged as a promising strategy for the prevention and treatment of MASLD. To this end, we develop AntiOxBEN<inf>2</inf>, a mitochondria-targeted compound generated by conjugating the antioxidant moiety of gallic acid with the lipophilic triphenylphosphonium cation . This design enables selective accumulation of AntiOxBEN<inf>2</inf> in the mitochondrial matrix, taking advantage of the organelle’s negative membrane potential. In multiple in vitro disease model s , AntiOxBEN<inf>2</inf> has demonstrated remarkable antioxidant properties, effectively mitigating oxidative stress and preserving mitochondrial function. However, effects on cellular and mitochondrial energy metabolism in vivo remain unexplored. In the present study, we tested whether chronic peripheral administration of AntiOxBEN<inf>2</inf> (0.5 or 2.5 mg/kg, 3x/week) could prevent MASLD development in male and female C57BL/6 J mice fed with a 30 % high-fat, 30 % high-sucrose (Western Diet, WD) diet for 16 weeks. Our results demonstrate that AntiOxBEN<inf>2</inf> treatment significantly reduced hepatic lipid accumulation in both sexes without affecting body weight. This reduction was accompanied by improvements in mitochondrial function, including enhanced fatty acid oxidation (FAO) and increased activities of mitochondrial electron transport chain (ETC) complexes. Moreover, AntiOxBEN<inf>2</inf> administration lowered circulating levels of hepatic damage markers (ALT and AST), as well as insulin and leptin. Notably, a clear sexual dimorphism was observed, with female mice displaying a more pronounced improvement in mitochondrial parameters. Collectively, these findings highlight the therapeutic potential of AntiOxBEN<inf>2</inf> for the prevention and/or treatment of MASLD. © © 2026. Published by Elsevier Masson SAS.

Abstract Metabolic syndrome (MetS) has been associated with disruptions in tissue mechanical homeostasis and inflammatory and metabolic derangements. However, the direct correlation between metabolic alterations and changes in tissue stiffness, and whether they could play a role as upstream initiators of disease pathology remains to be investigated. This emerging concept has yet to be put into clinical practice as many questions concerning the interplay between extracellular matrix mechanical properties and regulation of metabolic pathways remain unsolved. This review will highlight key foundational studies examining mutual regulation of cell metabolism and mechanotransduction, and opening questions lying ahead for better understanding MetS pathophysiology.

Abstract [No abstract available]

Abstract S-1 MitoPlates™ from Biolog enable the characterization of mitochondria’s function in live cells by measuring the rates of electron flow into and through the electron transport chain from different NADH or FADH2 producing metabolic substrates. This technology uses 96-well microplates pre-coated with triplicate repeats of a set of 31 substrates. Those 31 metabolic substrates have different routes of entry into the mitochondria, use different transporters, and are also oxidated by different dehydrogenases, producing reducing equivalents in the form of NADH or FADH2. The electrons produced upon oxidation of NADH or FADH2 at complex I or II, respectively, then travel to cytochrome c, where a tetrazolium redox dye (MC) can act as terminal acceptor, turning purple and absorbing at 590 nm. This mechanism allows the evaluation of cellular substrate preference by following the kinetics of MC reduction in the presence of selected substrates. In this chapter, we describe the step-by-step protocol to prepare an experiment using MitoPlate S-1 array and the OmniLog instrument to assess the metabolism of human dermal fibroblasts. We also give detailed information on how to analyze the raw data generated by the Biolog Data Analysis software to extract meaningful information and produce useful data visualizations, using reproducible methods based on a single structured dataset. © The Author(s), under exclusive license to Springer Science+Business Media, LLC, part of Springer Nature 2025.