Sandra Isabel Mota

Introduction: Physical inactivity is a major global health concern, while regular exercise yields well-documented physiological and metabolic benefits. Despite advances in molecular profiling, rapid, integrative, and cost-effective tools for assessing long-term adaptations to exercise remain limited. This study evaluated the potential of Fourier Transform Infrared (FTIR) spectroscopy, combined with machine learning (ML) algorithms, to discriminate between sedentary individuals and trained athletes (football players and ultramarathon runners) using multiple aqueous biofluids. Methods: A total of 132 participants (87 athletes and 45 sedentary individuals) were assessed. FTIR spectra were obtained from five biological matrices: serum, plasma, capillary blood, urine, and saliva. Data preprocessing included baseline correction, vector normalization, and spectral truncation. Dimensionality reduction and classification were conducted using Partial Least Squares Discriminant Analysis (PLS-DA) and a range of supervised learning models (Multilayer Perceptron (MLP), Random Forest, XGBoost and Decision Trees), with synthetic oversampling (SMOTE) applied within each cross-validation fold to address class imbalance. Data partitioning was performed at the participant level to prevent information leakage from repeated measures. Model performance was evaluated using cross-validation, with F1-score, area under the curve (AUC), balanced accuracy, and Matthews Correlation Coefficient (MCC) as primary metrics; bootstrapped 95% confidence intervals were estimated for each. Results: The best-performing models were obtained with capillary blood, serum, and plasma. A Decision Tree classifier applied to capillary blood spectra achieved a balanced accuracy of 0.917 (95% CI: 0.820–1.000), a weighted F1-score of 0.914, and an AUC of 0.937. An XGBoost classifier trained on serum spectra achieved a balanced accuracy of 0.765 (95% CI: 0.623–0.893) and an AUC of 0.877. In plasma, an MLP classifier trained across all three collection timepoints achieved a balanced accuracy of 0.757 (95% CI: 0.643–0.875) and an AUC of 0.909. Urine and saliva yielded substantially lower predictive accuracy (balanced accuracy below 0.60). Biochemical analysis of key spectral regions identified distinct differences in lipid- and protein-related functional groups between sedentary individuals and trained athletes, consistent with physiological adaptations to chronic exercise [1, 2]. Conclusion: This is the first study to apply FTIR spectroscopy across multiple biofluids to stratify individuals based on chronic exercise status. The findings demonstrate that FTIR spectroscopy, coupled with ML, offers a promising, label-free, and scalable approach for profiling physiological adaptations to exercise. These results support its further development for use in sports medicine, precision health monitoring, and personalized exercise prescription.

Background: Urine‐derived stem cells (UDSC) are an emerging, non‐invasive source of human stem cells combining easy collection, broad accessibility and high patient compliance with multilineage differentiation capacity. However, key gaps remain in UDSC research, particularly in understanding sex‐related differences and the lack of a validated cryopreservation protocol, a critical aspect for primary cells, given their variability in colony formation, proliferation rates and experimental timing. To address these limitations, this study aimed to establish, for the first time, a reliable protocol for UDSC cryopreservation and to explore potential sex‐related differences, with a specific focus on glycolysis and mitochondrial respiration. Methods: UDSC were isolated from urine samples of healthy donors (aged 27–50, 4 males and 4 females), cultured in 1:1 DMEM:KSFM supplemented with 10% fetal bovine serum and cryopreserved at passages 2–4 using the same medium with the sole addition of 5% dimethyl sulfoxide. Cells were evaluated for viability, apoptosis/necrosis, metabolic profile and multilineage differentiation potential. Comparisons were performed based on donor sex, as well as before and after cryopreservation. Results: Male‐ and female‐derived UDSC displayed no significant differences in viability and cell death or metabolic profile. Moreover, supervised and unsupervised machine learning methods were unable to discriminate between the two groups, allowing for pooled data analysis and improved statistical power. Similarly, fresh and cryopreserved UDSC displayed comparable viability, metabolic activity and multilineage differentiation relative to fresh cells, with no detectable differences in computational analyses. Conclusions: These findings support UDSC adoption for biobanking, disease modelling and regenerative medicine.

Background: Over the past few decades, the scientific community has recognized the impact of physical activity on health and performance. In parallel, researchers have been actively exploring novel methodologies to analyze the physiological and metabolic responses to exercise. Fourier transform infrared spectroscopy has emerged as a powerful tool in this effort, offering the potential to provide unique insights into exercise-related changes at the molecular level. Objective: The primary goal of this systematic review is to confirm the viability of utilizing Fourier transform infrared spectroscopy for the analysis of the biochemical changes associated with physical exercise and its potential applications. Methods: This systematic review adhered to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines and examined studies employing Fourier transform infrared spectroscopy to analyze exercise and physical activity, focusing on a biological sample collection and spectral analysis. Four databases (PubMed, SPORTDiscus, Web of Science, and Scopus) were searched, and inclusion criteria encompassed original English-language studies involving human participants aged 18–50 years, a biological sample collection (urine, saliva, and blood), and the use of Fourier transform infrared spectroscopy. The studies were analyzed considering the type of exercise or sport that was investigated, and also the type of spectral analysis conducted. Results: The review encompassed 15 studies that demonstrated the versatility of Fourier transform infrared spectroscopy in assessing various aspects of exercise, including metabolism, cardiovascular responses, and muscular fatigue. The largest study evaluated 57 athletes from several different sports. On average, almost all the studies were performed with around 20 athletes. Notably, the technique’s holistic approach allows for a comprehensive analysis of the complex network of metabolites and proteins within the human body. Data analysis methodologies, particularly when coupled with machine learning, show great potential for advancing the field of sports science. Conclusions: Fourier transform infrared spectroscopy emerges as a promising tool for monitoring and enhancing the performance of high-level athletes, preventing overtraining or even over-reaching, and assessing metabolism. Its accuracy, efficiency, and affordability also make it a candidate for broader applications in assessing the health and fitness of the general population. Future research should explore its applicability across diverse exercise modalities and demographic groups, aiming to prescribe exercise plans that consider a multitude of parameters for larger, more intricate exercise cohorts. Clinical Trial Registration: The study protocol was registered in the International Prospective Register of Systematic Reviews (PROSPERO) under the ID number CRD42023441965. Graphical

Amyloid‐beta peptide oligomers (AβO) have been considered “primum movens” for a cascade of events that ultimately cause selective neuronal death in Alzheimer's disease (AD). However, initial events triggered by AβO have not been clearly defined. Synaptic (Syn) N‐methyl‐d‐aspartate receptors (NMDAR) are known to activate cAMP response element‐binding protein (CREB), a transcriptional factor involved in gene expression related to cell survival, memory formation and synaptic plasticity, whereas activation of extrasynaptic (ESyn) NMDARs was linked to excitotoxic events. In AD brain, CREB phosphorylation/activation was shown to be altered, along with dyshomeostasis of intracellular Ca²⁺ (Ca²⁺_i). Thus, in this work, we analyze acute/early and long‐term AβO‐mediated changes in CREB activation involving Syn or ESyn NMDARs in mature rat cortical neurons. Our findings show that acute AβO exposure produce early increase in phosphorylated CREB, reflecting CREB activity, in a process occurring through Syn NMDAR‐mediated Ca²⁺ influx. Data also demonstrate that AβO long‐term (24 h) exposure compromises synaptic function related to Ca²⁺‐dependent CREB phosphorylation/activation and nuclear CREB levels and related target genes, namely Bdnf, Gadd45γ, and Btg2. Data suggest a dual effect of AβO following early or prolonged exposure in mature cortical neurons through the activation of the CREB signaling pathway, linked to the activation of Syn NMDARs. image

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. Highlights: ANT2 silencing promotes cell growth arrest and metabolic remodeling in CSCs. ANT2 depletion modulates HKII protein levels. ANT2 induce anoikis resistance in P19SCs

Stem cells have potential applications in the field of neurological diseases, as they allow for the development of new biological models. These models can improve our understanding of the underlying pathologies and facilitate the screening of new therapeutics in the context of precision medicine. Stem cells have also been applied in clinical tests to repair tissues and improve functional recovery. Nevertheless, although promising, commonly used stem cells display some limitations that curb the scope of their applications, such as the difficulty of obtention. In that regard, urine-derived cells can be reprogrammed into induced pluripotent stem cells (iPSCs). However, their obtaining can be challenging due to the low yield and complexity of the multi-phased and typically expensive differentiation protocols. As an alternative, urine-derived stem cells (UDSCs), included within the population of urine-derived cells, present a mesenchymal-like phenotype and have shown promising properties for similar purposes. Importantly, UDSCs have been differentiated into neuronal-like cells, auspicious for disease modeling, while overcoming some of the shortcomings presented by other stem cells for these purposes. Thus, this review assesses the current state and future perspectives regarding the potential of UDSCs in the ambit of neurological diseases, both for disease modeling and therapeutic applications.

Soluble Aβ_1–42 oligomers (AβO) are formed in the early stages of Alzheimer’s disease (AD) and were previously shown to trigger enhanced Ca²⁺ levels and mitochondrial dysfunction via the activation of N-methyl-D-aspartate receptors (NMDAR). Src kinase is a ubiquitous redox-sensitive non-receptor tyrosine kinase involved in the regulation of several cellular processes, which was demonstrated to have a reciprocal interaction towards NMDAR activation. However, little is known about the early-stage mechanisms associated with AβO-induced neurodysfunction involving Src. Thus, in this work, we analysed the influence of brief exposure to oligomeric Aβ_1–42 on Src activation and related mechanisms involving mitochondria and redox changes in mature primary rat hippocampal neurons. Data show that brief exposure to AβO induce H₂O₂-dependent Src activation involving different cellular events, including NMDAR activation and mediated intracellular Ca²⁺ rise, enhanced cytosolic and subsequent mitochondrial H₂O₂ levels, accompanied by mild mitochondrial fragmentation. Interestingly, these effects were prevented by Src inhibition, suggesting a feedforward modulation. The current study supports a relevant role for Src kinase activation in promoting the loss of postsynaptic glutamatergic synapse homeostasis involving cytosolic and mitochondrial ROS generation after brief exposure to AβO. Therefore, restoring Src activity can constitute a protective strategy for mitochondria and related hippocampal glutamatergic synapses.

Amyotrophic lateral sclerosis (ALS) is a severe and incurable neurodegenerative disease characterized by the progressive death of motor neurons, leading to paralysis and death. It is a rare disease characterized by high patient-to-patient heterogeneity, which makes its study arduous and complex. Extracellular vesicles (EVs) have emerged as important players in the development of ALS. Thus, ALS phenotype-expressing cells can spread their abnormal bioactive cargo through the secretion of EVs, even in distant tissues. Importantly, owing to their nature and composition, EVs’ formation and cargo can be exploited for better comprehension of this elusive disease and identification of novel biomarkers, as well as for potential therapeutic applications, such as those based on stem cell-derived exosomes. This review highlights recent advances in the identification of the role of EVs in ALS etiopathology and how EVs can be promising new therapeutic strategies.

Amyotrophic lateral sclerosis (ALS) is a severe and incurable neurodegenerative disease, char-acterized by the progressive death of motor neurons, leading to paralysis and death. It is a rare disease distinguished by high patient-to-patient heterogeneity, making its study arduous and complex. Extracellular vesicles (EVs) emerged as an important player in ALS development. Thus, ALS phenotype-expressing cells can spread their abnormal bioactive cargos through the secretion of EVs, even at far distant tissues. Importantly, due to their nature and composition, EVs’ formation and cargo can be exploited for the better comprehension of this elusive disease and identification of novel biomarkers, as well as for potential therapeutic applications, such as those based on stem cell-derived exosomes. This review highlights the recent advances in the identification of the role of EVs in ALS etiopathology and how EVs can be promising new approaches for therapeutic strategies.