Search Results (394)

The Lon protease homolog 1 (LONP1) is an ATP-dependent mitochondrial protease essential for maintaining proteostasis, bioenergetics, and cellular homeostasis. LONP1 plays a pivotal role in protein quality control, mitochondrial DNA maintenance, and oxidative phosphorylation system (OXPHOS) regulation, particularly under stress conditions. Dysregulation of LONP1 has been implicated in various pathologies, including cancer, metabolic disorders, and reproductive diseases, positioning it as a promising pharmacological target. This review examines compounds that modulate LONP1 activity, categorizing them into inhibitors and activators. Inhibitors such as CDDO and its derivatives selectively target LONP1, impairing mitochondrial proteolysis, inducing protein aggregation, and promoting apoptosis, particularly in cancer cells. Compounds like Obtusilactone A and proteasome inhibitors (e.g., MG262) demonstrate potent cytotoxicity, further expanding the therapeutic landscape. Conversely, LONP1 activators, including Artemisinin derivatives and 84-B10, restore mitochondrial function and protect against conditions such as polycystic ovary syndrome (PCOS) and acute kidney injury (AKI). Future research should focus on improving the specificity, bioavailability, and pharmacokinetics of these modulators. Advances in structural biology and drug discovery will enable the development of novel LONP1-targeted therapies, addressing diseases driven by mitochondrial dysfunction and proteostasis imbalance. Full article

Background: GM3 Synthase Deficiency (GM3SD) is a rare autosomal recessive neurodevelopmental disease characterized by recurrent seizures and neurological deficits. The disorder stems from mutations in the ST3GAL5 gene, encoding GM3 synthase (GM3S), a key enzyme in ganglioside biosynthesis. While enzyme deficiencies affecting ganglioside catabolism are well-documented, the consequences of impaired ganglioside biosynthesis remain less explored. Methods: To investigate GM3SD, we used a Human Embryonic Kidney 293-T (HEK293-T) knockout (KO) cell model generated via CRISPR/Cas9 technology. Lipid composition was assessed via high-performance thin-layer chromatography (HPTLC); glycohydrolase activity in lysosomal and plasma membrane (PM) fractions was enzymatically analyzed. Lysosomal homeostasis was evaluated through protein content analysis and immunofluorescence, and cellular bioenergetics was measured using a luminescence-based assay. Results: Lipidome profiling revealed a significant accumulation of lactosylceramide (LacCer), the substrate of GM3S, along with increased levels of monosialyl-globoside Gb5 (MSGb5), indicating a metabolic shift in glycosphingolipid biosynthesis. Lipid raft analysis revealed elevated cholesterol levels, which may impair microdomain fluidity and signal transduction. Furthermore, altered activity of lysosomal and plasma membrane (PM)-associated glycohydrolases suggests secondary deregulation of glycosphingolipid metabolism, potentially contributing to abnormal lipid patterns. In addition, we observed increased lysosomal mass, indicating potential lysosomal homeostasis dysregulation. Finally, decreased adenosine triphosphate (ATP) levels point to impaired cellular bioenergetics, emphasizing the metabolic consequences of GM3SD. Conclusions: Together, these findings provide novel insights into the molecular alterations associated with GM3SD and establish the HEK293-T KO model as a promising platform for evaluating potential therapeutic strategies. Full article

Huntington’s disease (HD) is a detrimental neurodegenerative disease caused by the expansion of a CAG triplet in the HTT gene. This mutation leads to the production of mutant Huntingtin (Htt) protein with toxic gain-of-function. The mHtt is responsible in several ways for the establishment of an intricate pathogenetic scenario in affected cells, particularly in HD neurons. Among the features of HD, oxidative stress plays a relevant role in the progression of the disease at the cellular level. Mitochondrial dysfunction, bioenergetic deficits, Reactive Oxygen Species (ROS) production, neuroinflammation, and general reduction of antioxidant levels are all involved in the promotion of a toxic oxidative environment, eventually causing cell death. Nonetheless, neuronal cells exert antioxidant molecules to build up defense mechanisms. Key components of these defensive mechanisms are the nuclear factor erythroid 2-related factor 2 (NRF2) and peroxisome proliferator-activated receptor gamma coactivator-1 α (PGC-1α). Thus, this review aims to describe the involvement of oxidative stress in HD by exploring the roles of NRF2 and PGC-1α, crucial actors in this play. Finally, antioxidant therapeutic strategies targeting such markers are discussed. Full article

Type 4 cardiorenal syndrome (CRS-4) is a pathology in which chronic kidney disease (CKD) triggers the development of cardiovascular disease. CKD pathophysiology produces alterations that can affect the bioenergetics of heart mitochondria, causing oxidative stress and reducing antioxidant glutathione (GSH) levels. GSH depletion alters protein function by affecting post-translational modifications such as S-glutathionylation (RS-SG), exacerbating oxidative stress, and mitochondrial dysfunction. On the other hand, N-acetylcysteine (NAC) is an antioxidant GSH precursor that modulates oxidative stress and RS-SG. Moreover, recent studies have found that NAC can activate the Sirtuin 3 (SIRT3) deacetylase in diseases. However, the role of NAC and its effects on mitochondrial function, redox signaling, and SIRT3 modifications in the heart during CRS-4 have not been studied. This study aimed to investigate the role of NAC in mitochondrial function, redox signaling, and SIRT3 in the hearts of animals with CRS-4 at two months of follow-up. Our results showed that the oral administration of NAC (600 mg/kg/day) improved blood pressure and reduced cardiac fibrosis. NACs’ protective effect was associated with preserving cardiac mitochondrial bioenergetics and decreasing these organelles’ hydrogen peroxide (H₂O₂) production. Additionally, NAC increased GSH levels in heart mitochondria and regulated the redox state, which coincided with an increase in nicotinamide adenine dinucleotide oxidized (NAD⁺) levels and a decrease in mitochondrial acetylated lysines. Finally, NAC increased SIRT3 levels and the activity of superoxide dismutase 2 (SOD-2) in the heart. Thus, treatment with NAC decreases mitochondrial alterations, restores redox signaling, and decreases SIRT3 disturbances during CRS-4 through an antioxidant defense mechanism. Full article

Background/Objectives: Colorectal cancer (CRC) remains one of the most common and deadly malignancies worldwide, driven by metabolic reprogramming and mitochondrial dysfunction, which support tumor growth and progression. Several studies showed that nutrition is a contributing factor in the prevention and management of CRC. In this context, carnitines, amino acid derivatives abundant in food of animal origin, such as meat and milk, are crucial for mitochondrial function. Recently, l-carnitine and acetyl-l-carnitine have received particular attention due to their antioxidant, anti-inflammatory, and antitumor properties. However, to date, there is no conclusive evidence on the effects of l-carnitine and acetyl-l-carnitine in CRC or the underlying molecular mechanism. Methods: In this study, we investigated in HCT 116 and HT-29 CRC cells the effects of l-carnitine and acetyl-l-carnitine on mitochondrial homeostasis by XF HS Seahorse Bioanalyzer and cell death pathways by flow cytometry and western blot assays. Results: Data showed that l-carnitine and acetyl-l-carnitine reduced cell viability (p < 0.001), modulated cellular bioenergetics, and induced oxidative stress (p < 0.001). These phenomena promoted autophagic flux and the mitophagy process via PINK1 and Parkin modulation after 72 h of treatment. Of note, the combined treatment with l-carnitine and acetyl-l-carnitine showed a synergistic effect and enhanced the effect of single carnitines on tumor cell growth and metabolic dysfunction (p < 0.05). Moreover, exposure to l-carnitine and acetyl-l-carnitine promoted CRC cell apoptosis, suggesting a mechanism involving mitophagy-related cell death. These data were associated with increased SIRT4 expression levels (p < 0.01) and the activation of AMPK signaling (p < 0.01). Conclusions: Overall, the results, by supporting the importance of nutritional factors in CRC management, highlight l-carnitine and acetyl-l-carnitine as promising agents to target CRC metabolic vulnerabilities. Full article

Age-related oxidative stress is a critical factor in vascular dysfunction, contributing to hypertension and atherosclerosis. Smooth muscle cells and endothelial cells are particularly susceptible to oxidative damage, which exacerbates vascular aging through cellular senescence, chronic inflammation, and arterial stiffness. Gasotransmitters—hydrogen sulfide (H₂S), nitric oxide (NO), and carbon monoxide (CO)—are emerging as promising therapeutic agents for counteracting these processes. This review synthesizes findings from recent studies focusing on the mechanisms by which H₂S, NO, and CO influence vascular smooth muscle and endothelial cell function. Therapeutic strategies involving exogenous gasotransmitter delivery systems and combination therapies were analyzed. H₂S enhances mitochondrial bioenergetics, scavenges ROS, and activates antioxidant pathways. NO improves endothelial function, promotes vasodilation, and inhibits platelet aggregation. CO exhibits cytoprotective and anti-inflammatory effects by modulating heme oxygenase activity and ROS production. In preclinical studies, gasotransmitter-releasing molecules (e.g., NaHS, SNAP, CORMs) and targeted delivery systems show significant promise. Synergistic effects with lifestyle modifications and antioxidant therapies further enhance their therapeutic potential. In conclusion, gasotransmitters hold significant promise as therapeutic agents to combat age-related oxidative stress in vascular cells. Their multifaceted mechanisms and innovative delivery approaches make them potential candidates for treating vascular dysfunction and promoting healthy vascular aging. Further research is needed to translate these findings into clinical applications. Full article

Background/Objectives: Extracts of the plant Centella asiatica can enhance mitochondrial function, promote antioxidant activity and improve cognitive deficits. Asiatic acid (AA) is one of the constituent triterpene compounds present in the plant. In this study, we explore the effects of AA on brain mitochondrial function, antioxidant response and cognition in a beta-amyloid (Aβ)-overexpressing 5xFAD mouse line. Methods: Six- to seven-month-old 5xFAD mice were treated with 1% AA for 4 weeks. In the last week of treatment, associative memory was assessed along with mitochondrial bioenergetics and the expression of mitochondrial and antioxidant response genes from isolated cortical synaptosomes. The Aβ plaque burden was also evaluated. Results: AA treatment resulted in improvements in associative memory in female 5xFAD mice without altering the Aβ plaque burden. Cortical mitochondrial function and mitochondrial gene expression were increased in the AA-treated female 5xFAD mice, as was the expression of antioxidant genes. More modest effects of AA on cortical mitochondrial function and mitochondrial and antioxidant gene expression were observed in male 5xFAD mice. Conclusions: Oral AA treatment improved cognitive and mitochondrial function and activated antioxidant in Aβ-overexpressing mice. These changes occurred independent of alterations in Aβ plaque burden, suggesting that AA could have translational therapeutic relevance in later-stage AD when plaques are well established. Full article

Carnitine O-acetyltransferase (CRAT) is a key mitochondrial enzyme involved in maintaining metabolic homeostasis by mediating the reversible transfer of acetyl groups between acetyl-CoA and carnitine. This enzymatic activity ensures the optimal functioning of mitochondrial carbon flux by preventing acetyl-CoA accumulation, buffering metabolic flexibility, and regulating the balance between fatty acid and glucose oxidation. CRAT’s interplay with the mitochondrial carnitine shuttle, involving carnitine palmitoyltransferases (CPT1 and CPT2) and the carnitine carrier (SLC25A20), underscores its critical role in energy metabolism. Emerging evidence highlights the structural and functional diversity of CRAT and structurally related acetyltransferases across cellular compartments, illustrating their coordinated role in lipid metabolism, amino acid catabolism, and mitochondrial bioenergetics. Moreover, the structural insights into CRAT have paved the way for understanding its regulation and identifying potential modulators with therapeutic applications for diseases such as diabetes, mitochondrial disorders, and cancer. This review examines CRAT’s structural and functional aspects, its relationships with carnitine shuttle members and other carnitine acyltransferases, and its broader role in metabolic health and disease. The potential for targeting CRAT and its associated pathways offers promising avenues for therapeutic interventions aimed at restoring metabolic equilibrium and addressing metabolic dysfunction in disease states. Full article

Mitochondria serve an essential metabolic and energetic role in cellular activity, and their dysfunction has been implicated in a wide range of disorders, including cardiovascular conditions, neurodegenerative disorders, and metabolic syndromes. Mitochondria-targeted therapies, such as Elamipretide (SS-31, MTP-131, Bendavia), have consequently emerged as a topic of scientific and clinical interest. Elamipretide has a unique structure allowing for uptake in a variety of cell types and highly selective mitochondrial targeting. This mitochondria-targeting tetrapeptide selectively binds cardiolipin (CL), a lipid found in the inner mitochondrial membrane, thus stabilizing mitochondrial cristae structure, reducing oxidative stress, and enhancing adenosine triphosphate (ATP) production. Preclinical studies have demonstrated the protective and restorative efficacy of Elamipretide in models of heart failure, neurodegeneration, ischemia–reperfusion injury, metabolic syndromes, and muscle atrophy and weakness. Clinical trials such as PROGRESS-HF, TAZPOWER, MMPOWER-3, and ReCLAIM elaborate on preclinical findings and highlight the significant therapeutic potential of Elamipretide. Further research may expand its application to other diseases involving mitochondrial dysfunction as well as investigate long-term efficacy and safety of the drug. The following review synthesizes current knowledge of the structure, mechanisms of action, and the promising therapeutic role of Elamipretide in stabilizing mitochondrial fitness, improving mitochondrial bioenergetics, and minimizing oxidative stress. Full article

Background: Implants are integral to modern orthopedic surgery. The outcomes are good, but infections remain a serious issue. Staphylococcus aureus (S. aureus), along with Staphylococcus epidermidis, are predominant pathogens responsible for implant-associated infections, as conventional antibiotic treatments often fail due to biofilm formation or the pathogens’ ability to invade cells and to persist intracellularly. Objectives: This study therefore focused on interactions of S. aureus isolates from infected implants with MG63 and SaOS2 osteoblasts by investigating the adhesion, invasion, and the impact on the bioenergetics of osteoblasts. Methods and Results: We found that the ability of S. aureus to adhere to osteoblasts depends on the isolate and was not associated with a single gene or expression pattern of characteristic adhesion proteins, and further, was not correlated with invasion. However, analysis of invasion capabilities identified better invasion conditions for S. aureus isolates with the SaOS2 osteoblastic cells. Interestingly, metabolic activity of osteoblasts remained unaffected by S. aureus infection, indicating cell survival. In contrast, respiration assays revealed an altered mitochondrial bioenergetic turnover in infected cells. While basal as well as maximal respiration in MG63 osteoblasts were not influenced statistically by S. aureus infections, we found increased non-mitochondrial respiration and enhanced glycolytic activity in the osteoblasts, which was again, more pronounced in the SaOS2 osteoblastic cells. Conclusions: Our findings highlight the complexity of S. aureus-host interactions, where both the pathogen and the host cell contribute to intracellular persistence and survival, representing a major factor for therapeutic failures. Full article

Glutaminase controls the first step in glutaminolysis, impacting bioenergetics, biosynthesis and oxidative stress. Two isoenzymes exist in humans, GLS and GLS2. GLS is considered prooncogenic and overexpressed in many tumours, while GLS2 may act as prooncogenic or as a tumour suppressor. Glioblastoma cells usually lack GLS2 while they express high GLS. We investigated how GLS2 expression modifies the metabolism of glioblastoma cells, looking for changes that may explain GLS2’s potential tumour suppressive role. We developed LN-229 glioblastoma cells stably expressing GLS2 and performed isotope tracing using U-¹³C-glutamine and metabolomic quantification to analyze metabolic changes. Treatment with GLS inhibitor CB-839 was also included to concomitantly inhibit endogenous GLS. GLS2 overexpression resulted in extensive metabolic changes, altering the TCA cycle by upregulating part of the cycle but blocking the synthesis of the 6-carbon intermediates from acetyl-CoA. Expression of GLS2 caused downregulation of PDH activity through phosphorylation of S293 of PDHA1. GLS2 also altered nucleotide levels and induced the accumulation of methylated metabolites and S-adenosyl methionine. These changes suggest that GLS2 may be a key regulator linking glutamine and glucose metabolism, also impacting nucleotides and epigenetics. Future research should ascertain the mechanisms involved and the generalizability of these findings in cancer or physiological conditions. Full article

Advancements in cellular imaging have significantly enhanced our understanding of membrane potential and Ca²⁺ dynamics, which are crucial for various cellular processes. Voltage-sensitive dyes (VSDs) are pivotal in this field, enabling non-invasive, high-resolution visualization of electrical activity in cells. This review discusses the various types of VSDs, including electrochromic, Förster Resonance Energy Transfer (FRET)-based, and Photoinduced Electron Transfer (PeT)-based dyes. VSDs are essential tools for studying mitochondrial activity and neuronal function and are frequently used in conjunction with Ca²⁺ indicators to elucidate the complex relationship between membrane potential and Ca²⁺ fluxes. The development of novel dyes with improved photostability and reduced toxicity continues to expand the potential of VSDs in biomedical research. This review underscores the importance of VSDs in advancing our understanding of cellular bioenergetics, signaling, and disease mechanisms. Full article

The current study proposes the in vitro and in silico anticancer evaluation of clove (Syzygium aromaticum L.) essential oil (CEO). The steam hydrodistillation method used yielded 10.7% (wt) CEO. GC-MS analysis revealed that the obtained oil is rich in eugenol (75%), β-caryophyllene (20%), and α- caryophyllene (2.8%) and also contains several other minor components accounting for approximately 1.5%. The DPPH-based scavenging antioxidant activity was assessed for the obtained CEO, exhibiting an IC₅₀ value of 158 μg/mL. The cytotoxic effects of CEO, its major component eugenol, and CEO solubilized with Tween-20 and PEG-400 were tested against both noncancerous HaCaT cells and HT-29 human colorectal adenocarcinoma, RPMI-7951 melanoma, A431 skin carcinoma, and NCI-H460 non-small lung cancer cells, using the Alamar Blue and LDH assay after 48 h treatment. The Tween-20 and PEG-400 CEO formulations, at 200 μg/mL, recorded the highest cytotoxic and selective effects against RPMI-7951 (72.75% and 71.56%), HT-29 (71.51% and 45.43%), and A431 cells (61.62% and 59.65%). Furthermore, CEO disrupted mitochondrial function and uncoupled oxidative phosphorylation. This effect was more potent for the CEO against the RPMI-7951 and HT-29 cells, whereas for the other two tested cell lines, a more potent inhibition of mitochondrial function was attributed to eugenol. The present study is the first to specifically investigate the effects of CEO and Tween-20 and PEG-400 CEO formulations on the mitochondrial function of RPMI-7951, HT-29, A431, and NCI-H460 cancer cell lines using high-resolution respirometry, providing novel insights into their impact on mitochondrial respiration and bioenergetics in cancer cells. The results obtained may explain the increased ROS production observed in cancer cell lines treated with eugenol and CEO. Molecular docking identified potential protein targets, related to the CEO anticancer activity, in the form of PI3Kα, where the highest active theoretical inhibitor was calamenene (−7.5 kcal/mol). Docking results also showed that calamenene was the overall most active theoretical inhibitor for all docked proteins and indicated a potential presence of synergistic effects among all CEO constituents. Full article

The green synthesis of silver (Ag) and zinc oxide (ZnO) nanoparticles (NPs), as well as Ag/Ag₂O/ZnO nanocomposites (NCs), using polar and apolar extracts of Chlorella vulgaris, offers a sustainable method for producing nanomaterials with tunable properties. The impact of the synthesis environment and the nanomaterials’ characteristics on cytotoxicity was evaluated by examining reactive species production and their effects on mitochondrial bioenergetic functions. Cytotoxicity assays on PC12 cells, a cell line originated from a rat pheochromocytoma, an adrenal medulla tumor, demonstrated that Ag/Ag₂O NPs synthesized with apolar (Ag/Ag₂O NPs A) and polar (Ag/Ag₂O NPs P) extracts exhibited significant cytotoxic effects, primarily driven by Ag⁺ ion release and the disruption of mitochondrial function. However, it is more likely the organic content, rather than size, influenced anticancer activity, as commercial Ag NPs, despite smaller crystallite sizes, exhibit less effective activity. ZnO NPs P showed increased reactive oxygen species (ROS) generation, correlated with higher cytotoxicity, while ZnO NPs A produced lower ROS levels, resulting in diminished cytotoxic effects. A comparative analysis revealed significant differences in LD₅₀ values and toxicity profiles. Differentiated PC12 cells showed higher resistance to ZnO, while AgNPs and Ag/Ag₂O-based materials had similar effects on both cell types. This study emphasizes the crucial role of the synthesis environment and bioactive compounds from C. vulgaris in modulating nanoparticle surface chemistry, ROS generation, and cytotoxicity. The results provide valuable insights for designing safer and more effective nanomaterials for biomedical applications, especially for targeting tumor-like cells, by exploring the relationships between nanoparticle size, polarity, capping agents, and nanocomposite structures. Full article

Broiler breeder hens allowed ad libitum (Ad) feed intake developed obesity and cardiac pathogenesis and thereby were susceptible to sudden death. A supplement of 69 µg 25-hydroxycholecalciferol (25-OH-D3)/kg feed rescued the livability of feed-restricted (R) and Ad-hens (mortality; 6.7% vs. 8.9% and 31.1% vs. 48.9%). Necropsy with the surviving counterparts along the time course confirmed alleviation of myocardial remodeling and functional failure by 25-OH-D3, as shown by BNP and MHC-β expressions, pathological hypertrophy, and cardiorespiratory responses (p < 0.05). 25-OH-D3 mitigated cardiac deficient bioenergetics in Ad-hens by rescuing PGC-1α activation, mitochondrial biogenesis, dynamics, and electron transport chain complex activities, and metabolic adaptions in glucose oxidation, pyruvate/lactate interconversion, TCA cycle, and β-oxidation, as well as in TG and ceramide accumulation to limit lipotoxic development (p < 0.05). Supplemental 25-OH-D3 also sustained Nrf2 activation and relieved MDA accumulation, protein carbonylation, and GSH depletion to potentiate cell survival in the failing heart (p < 0.05). Parts of the redox amendments were mediated via lessened blood hematocrit and heme metabolism, and improved iron status and related gene regulations (p < 0.05). In conclusion, 25-OH-D3 ameliorates cardiac pathological remodeling and functional compromise to rescue the livability of obese hens through metabolic flexibility and mitochondrial bioenergetics, and by operating at antioxidant defense, and heme and iron metabolism, to maintain redox homeostasis and sustain cell viability. Full article