Cecilia Giulivi

GLP-1 receptor agonists (e.g., semaglutide; GLP-1 RAs) treat Type 2 Diabetes and obesity, mainly by improving glycemic control, suppressing appetite, delaying gastric emptying, and inducing weight loss. Emerging evidence suggests they also directly affect mitochondrial function independently of systemic metabolism. To our knowledge, this is the first systematic review and meta-analysis examining direct mitochondrial effects of GLP-1 RAs in human-derived in vitro models. Of 1547 records identified (1203 screened after deduplication), 17 studies met the criteria, and only 11 contributed to the quantitative synthesis of mitochondrial outcomes. Outcomes included mitochondrial membrane potential (MMP), bioenergetics (ATP-linked oxygen consumption, respiration, ATP production), and mitochondrial reactive oxygen species (MitoROS). Meta-analysis demonstrated significantly improved bioenergetics (SMD = 1.109, 95% CI: 0.556–1.662, P < 0.001) and reduced MitoROS (SMD = −3.489, 95% CI: −6.690 to −0.288, P = 0.034) following GLP-1RA treatment. No significant effect on MMP was observed in the primary analysis (SMD = 0.997, 95% CI: −1.678 to 3.672, P = 0.459), although an exploratory sensitivity analysis excluding statistically identified outlying effect sizes suggested a potential improvement in MMP (SMD = 3.145, 95% CI: 2.147–4.144, P < 0.01); however, this finding should be interpreted cautiously. Overall certainty of the evidence was very low for the primary outcomes due to methodological limitations, substantial heterogeneity, imprecision, and publication bias in some outcomes. Only the MMP sensitivity analysis achieved low-certainty evidence. These findings suggest that GLP-1 RAs may directly promote mitochondrial health, but more rigorous, standardized, and independent studies are needed to confirm their relevance to whole-body physiology.

Wilson disease (WD) is an inherited disorder of copper metabolism characterized by hepatic copper accumulation, mitochondrial injury, and systemic metabolic dysfunction. Metformin is a widely used antihyperglycemic agent with known effects on mitochondrial metabolism and cellular redox state. We tested whether metformin modifies hepatic mitochondrial abnormalities in a mouse model of WD, stratified by sex. Adult male and female Atp7b ^−/− mice were treated with metformin in drinking water (500 mg/kg/day) or water alone for 2 weeks. Liver mitochondria were evaluated by transmission electron microscopy and quantitative morphometry, respiratory chain enzyme activities, reactive oxygen species production, hepatic and mitochondrial copper and iron content, and targeted glucocorticoid and bile acid profiling. At baseline, female Atp7b ^−/− mice exhibited greater mitochondrial ultrastructural injury, smaller mitochondrial size, and higher hepatic and mitochondrial copper and iron levels compared with males. Metformin exposure was higher in females and was associated with marked changes in mitochondrial morphology, including increased size and more regularized structural features, along with alterations in respiratory enzyme activities, reduced oxidative stress, and changes in glucocorticoid and bile acid profiles. In contrast, males showed more limited structural and biochemical changes following treatment. These findings identify sex as an important determinant of mitochondrial phenotype and response to metformin in WD and support further investigation of sex-informed therapeutic strategies.

WDFY3/ALFY is an adaptor protein involved in selective autophagy. Loss of Wdfy3 in mice causes severe deficits in neuronal health, and pathogenic mutations in WDFY3 are associated with neurodevelopmental disorders in humans. As impaired autophagy is increasingly implicated in Parkinson’s disease (PD) and other neurodegenerative disorders, we investigated whether Wdfy3 haploinsufficiency produces early molecular and cellular signatures of neurodegeneration in Wdfy3 ^+/lacZ mice, given that these diseases often exhibit presymptomatic alterations preceding overt clinical manifestations. Cortical tissue from 3-month-old presymptomatic mice showed significant proteomic overlap with both patient-derived PD cell lines and human brain proteomic datasets, particularly from the substantia nigra, underscoring the translational relevance of this model. Consistent with disease progression, immunofluorescence analyses of the cortex and substantia nigra from 14-month-old mice revealed significant dysregulation of multiple markers associated with neurodegeneration. Together, these findings demonstrate that impaired autophagy resulting from reduced Wdfy3 expression recapitulates key features of neurodegenerative disease at both early and later stages. By providing a platform to investigate presymptomatic pathogenic mechanisms, this model may inform the development and testing of future diagnostic and therapeutic strategies aimed at preserving neuronal health.

Background & Aims: Wilson disease (WD) is a genetic disorder of copper metabolism caused by ATP7B mutations, leading to hepatic and systemic copper accumulation. While lysosomes are early storage sites, mitochondria appear highly vulnerable to copper toxicity. We performed a systematic review and meta–analysis to assess mitochondrial outcomes in WD patients and animal models. Methods: PubMed, Scopus, and SciFinder were searched through 11 September 2025, for studies reporting hepatic mitochondrial endpoints in WD (in patients and models using mice, rats, and dogs). Outcomes included mitochondrial copper, morphology, oxidative stress, mtDNA copy number, ATP production, and respiratory Complex activities. Random–effects meta–analyses were conducted. Results: Thirteen studies met the inclusion criteria. Mitochondrial copper was consistently elevated (standardized mean difference ±standard error: 6.7 ± 0.9, P < 0.001), with ultrastructural abnormalities (4 ± 2, P = 0.012). Oxidative stress markers increased (2.9 ± 0.9, P = 0.001), while MnSOD and aconitase declined with disease progression. mtDNA copy number was reduced (−0.7 ± 0.3, P = 0.032). ATP synthesis (−1.5 ± 0.6, P = 0.023) and Complex activities (−1.0 ± 0.3, P = 0.001) were impaired, especially in older or symptomatic subjects. Citrate synthase activity increased (2.8 ± 0.9, P = 0.003), consistent with compensatory biogenesis. Several abnormalities appeared in presymptomatic or young animals. Conclusion: Across human and animal studies, hepatic mitochondria in WD exhibit copper accumulation, structural injury, impaired bioenergetics, oxidative stress, and mitochondrial genome loss. Mitochondrial dysfunction arises early and worsens with progression, highlighting it as a central pathogenic feature and therapeutic target.

Introduction Bruce Ames stands among the most influential biochemists of the past half-century, leaving a profound mark on genetics, toxicology, nutrition, and aging research. Best known for developing the Ames test, a bacterial assay that detects mutagenic chemicals, Ames helped establish the principle that environmental mutagens can be reliably measured and systematically screened (1). This transformed toxicology and cancer prevention, saving countless lives by enabling the regulation of carcinogens. Yet Ames's legacy extends beyond mutagen detection. In the latter part of his career, he focused on oxidative stress and mitochondrial DNA (mtDNA) mutagenicity as central players in the biology of aging (2). While the foundational ideas of oxidative damage and mitochondrial contribution to aging were first proposed by researchers such as Gershman and Harman, Ames contributed by integrating these concepts with experimental observations on mitochondrial decay, nutrition, and disease. He highlighted how reactive oxygen species (ROS) produced during mitochondrial respiration could contribute to cumulative mtDNA damage, potentially impairing mitochondrial function over time. Ames also emphasized the role of micronutrients in modulating this process, proposing that suboptimal nutrition could accelerate oxidative damage and mitochondrial decline through his triage theory (3) (Figure 1). His work helped translate earlier theoretical ideas into a broader framework linking oxidative stress, mitochondrial function, and age-related health outcomes. While this concept was groundbreaking, the field has since evolved. Contemporary research has revealed a more complex picture, with some scientists challenging the causal role of mtDNA damage in aging, proposing instead that mitochondrial dysfunction may arise from signaling changes, metabolic imbalances, or programmed processes rather than cumulative mutations (4). This paper will examine Bruce Ames's contributions, with particular focus on mtDNA mutagenicity, and critically assess how his theories shaped — and continue to spark debate within — modern biogerontology. The Ames Test and the Assessment of Mutagenicity In the 1970s, Ames introduced a simple yet powerful tool for detecting chemical mutagens: a bacterial assay using strains of Salmonella typhimurium engineered to be highly sensitive to DNA mutations. If exposure to a chemical restored growth via human or rat liver-activated metabolism in these bacteria (via reversion mutations), the compound was considered mutagenic. Importantly, Ames demonstrated that many environmental chemicals, including industrial pollutants, food additives, and pesticides, scored positive in the assay — and many of these same compounds later proved carcinogenic in animals (5). The test revolutionized toxicology by offering a rapid, inexpensive alternative to long-term rodent studies. Regulatory agencies worldwide adopted it to screen thousands of compounds, dramatically reducing public exposure to carcinogens. The "Ames test" also established a broader principle: genetic mutagenesis underpins carcinogenesis, and therefore, mutagens can be used as predictors of cancer risk. This work reflected Ames's larger intellectual project: to bridge laboratory assays with real-world human health, from chemical safety to disease prevention. A Shift Toward Oxidative Stress and mtDNA Damage By the 1980s, Ames expanded his focus from exogenous mutagens (environmental chemicals) to endogenous sources of DNA damage within the cell. He became especially interested in mitochondria, the cellular organelles that generate energy but also produce ROS as a byproduct of oxidative phosphorylation (6-46). Unlike nuclear DNA, mtDNA is highly vulnerable. It is located near the electron transport chain, where ROS are generated, lacks protective histones, and has more limited repair mechanisms. Ames proposed that cumulative mtDNA mutations lead to a decline in mitochondrial efficiency, greater ROS leakage, and a vicious cycle of escalating damage (2). This "mitochondrial decay" hypothesis became central to his later research, with implications for cancer, neurodegeneration, cardiovascular disease, and aging. Ames further argued that nutrition plays a key role in modulating this process (6, 7, 10, 11, 24-27, 35, 38, 40, 41, 43). His "triage theory" suggested that when micronutrients (such as vitamins, minerals, and antioxidants) are limited, the body prioritizes short-term survival functions over long-term DNA maintenance. As a result, suboptimal nutrition accelerates oxidative damage, hastening mitochondrial decline and aging (3). An example of how modest micronutrient deficiencies can lead to long-term damage is illustrated in Ames' work on iron deficiency. Iron, an essential trace mineral for iron-sulfur clusters and heme synthesis, enables complex function in the electron transport chain. Ames posits that when iron is limited, decreased heme and iron-sulfur cluster availability impairs electron transport and causes mitochondrial uncoupling and superoxide release (44). If iron deficiency is persistent over time, the resulting ROS leads to ongoing oxidative stress, mtDNA damage, and mitochondrial decline associated with age. Subsequently, if iron deficiency is exacerbated, the preceding symptoms lead to iron deficiency anemia (47). This framework, applied to other micronutrients, has elevated nutrition and metabolism as key determinants of genomic stability and longevity. The work of Dr. Ames can be cross-referenced with that of our team, which has also extensively studied mitochondrial dysfunction in the context of aging and neurodegeneration. However, our focus is more disease-specific. While Dr. Ames emphasized systemic mitochondrial decay and the role of oxidative damage in aging and age-related diseases (2), our research explores mitochondrial bioenergetics, redox balance, and apoptotic pathways in long-lived or post-mitotic...

Mitochondria are central to cellular energy production and the regulation of oxidative stress. Traditional methods for assessing mitochondrial ATP and reactive oxygen species (ROS) rely on metal probes, which unintentionally ground the system, confounding results. To investigate the impact of grounding on mitochondrial function, we utilized fluorescence‐based experiments to assess these mitochondrial outcomes under three conditions: wired (grounded), sham, and naïve. Mitochondria under grounded conditions produced significantly more ATP (by 5–11%), reduced ROS production (by 22–33%), and decreased mitochondrial membrane potential (by 5–6%) than sham and naïve. These findings indicate that grounding improves mitochondrial bioenergetics by reducing oxidative stress. Future research should explore the broader implications of grounding over time on mitochondrial health and its potential therapeutic applications.

The field of molecular biosciences has long been driven by curiosity, innovation, and an unyielding quest for knowledge. Yet, despite their groundbreaking contributions, women remain underrepresented in scientific research, constituting less than 30% of researchers worldwide (1). This stark reality highlights the persistent challenges posed by gender biases and stereotypes, which continue to deter many women from pursuing careers in STEM (2,3). However, progress is being made, and interventions aiming at closing the gender gap, as mentoring programs, scholarships, and initiatives such as the Women in Science series by Frontiers in Molecular Biosciences play a crucial role in amplifying the voices of women researchers and showcasing their invaluable contributions to science.The latest collection highlights diverse and cutting-edge research in cellular biochemistry, spanning topics from disease mechanisms to novel therapeutic approaches. Dr. Alejandra Tomas and her team explore the variability in patient responses to incretin therapy for Type 2 diabetes, shedding light on the molecular and cellular factors influencing treatment success (4). Meanwhile, Rosa Catapano and colleagues investigate the role of the ZNF224 protein in chronic lymphocytic leukemia, uncovering its potential as a prognostic marker and its link to the NF-kB survival pathway (5).Beyond human disease, Zineb Fechtali-Moute et al. delve into the life cycle of Acanthamoeba castellanii, a free-living amoeba that can cause severe infections. Their study identifies enzyme treatments that promote excystment and rapid trophozoite proliferation, paving the way for potential therapeutic interventions (6). Estelle Sontag's research team examines the role of PP2A methylation in tight junction assembly, providing new insights into cell polarity and epithelial barrier function (7). Finally, Catarina Pimpão's review highlights the emerging role of aquaglyceroporin modulators in treating diseases related to energy homeostasis, demonstrating the translational impact of cellular biochemistry (8).These studies advance scientific understanding and underscore women's critical role in driving innovation and discovery. By celebrating their contributions, we reaffirm the importance of gender equality in science and encourage future generations of women to break barriers and pursue careers in STEM. Science thrives on diversity, and by fostering inclusivity, we ensure a more robust and dynamic research community-one that benefits all of humanity.