Search Results (35,018)

Mitochondrial dysfunction and impairment of high-energy phosphate transfer are increasingly recognised as shared pathogenic features across neurological disorders. Because neurons require large amounts of ATP to sustain synaptic transmission, ion gradients, axonal transport, and intracellular signalling, they are especially vulnerable to disturbances in energy metabolism. Neurological dysfunction, therefore, cannot be explained solely by reduced mitochondrial ATP production. It also involves failure of the creatine kinase/phosphocreatine (CK/PCr) and adenylate kinase/AMP-activated protein kinase (AK–AMPK) systems, which normally support local ATP buffering, high-energy phosphate transfer, and intracellular energy homeostasis. In parallel, extracellular ATP-dependent purinergic dysregulation contributes to glia-mediated inflammation, synaptic dysfunction, and cell death, linking intracellular energy failure to abnormal intercellular signalling. In this review, we integrate these mechanisms into a shared pathological continuum of disrupted energy homeostasis. We then compare Alzheimer’s disease, Parkinson’s disease, and epilepsy as representative disorders with shared and disease-specific manifestations of this continuum, characterised respectively by chronic cerebral energy crisis, selective metabolic fragility, and acute energy overload with purinergic dysregulation. Finally, we discuss how this comparative perspective may help identify shared therapeutic opportunities while preserving disorder-specific interpretation. Full article

Mandibular condylar cartilage (MCC) exhibits greater susceptibility to mechanical stress-induced degeneration than tibial articular cartilage (TAC). This study investigated whether differential epigenetic regulation of nuclear factor erythroid 2-related factor 2 (Nrf2), a master regulator of antioxidant responses, is associated with distinct antioxidant capacities between these cartilage types. Cartilage tissues from 5-week-old male ICR mice (n = 16 for gene analyses, n = 8 for protein analyses) were obtained using laser microdissection. Gene and protein expression was analyzed by microarray, real-time RT-PCR, and immunohistochemistry. DNA methylation of the Nrf2 promoter was evaluated using pyrosequencing and high-resolution melting analysis. Nrf2 expression in MCC was approximately 1/10 that in TAC at mRNA level and only 5% at protein level. Downstream antioxidant enzymes (NQO1, G6PD, HO-1) showed significantly reduced expression in MCC. Oxidative DNA damage marker 8-OHdG was significantly elevated in MCC compared to TAC (20.0% vs. 10.7%, p < 0.05). The Nrf2 promoter region showed higher DNA methylation levels in MCC, confirmed by high-resolution melting analysis. Higher Nrf2 promoter methylation in MCC is associated with reduced antioxidant capacity and elevated oxidative damage. This epigenetic–antioxidant relationship may contribute to MCC’s vulnerability to mechanical stress-induced degeneration and represents a potential therapeutic target for temporomandibular joint disorders. Full article

Amino alcohols are a class of compounds bearing both amino and hydroxyl groups, ubiquitous in natural products and extensively utilized as key structural motifs in pharmaceuticals and functional materials. Owing to their structural diversity, inherent chirality, and high reactivity, they exhibit significant application value in the pharmaceutical field, materials industry, and organic synthesis. Compared with chemical synthesis, which suffers from limitations such as insufficient enantioselectivity, dependence on precious metal catalysts, and environmental concerns, biosynthesis offers core advantages of high stereoselectivity, mild reaction conditions, and environmental sustainability. This review systematically delineates the diverse applications of amino alcohols in the pharmaceutical field (e.g., anti-HIV, antimalarial, and antitumor drugs), materials industry (e.g., polymer modification and metal corrosion protection), and organic synthesis (e.g., chiral ligands and catalysts). Particular emphasis is placed on the biosynthetic strategies and pathways of representative amino alcohols, including ethanolamine, (2S,3R)-2-amino-1,3,4-butanetriol, (R)-3-amino-1-butanol, sphingosine, and metaraminol, as well as the metabolic engineering design principles and downstream processing technologies for amino alcohol biosynthesis. Although current biosynthetic approaches still face bottlenecks in enzyme catalytic efficiency, substrate tolerance, cofactor regeneration, product toxicity, and thermodynamic equilibrium, substantial improvements in synthetic efficiency and stereoselectivity have been achieved through protein engineering, metabolic engineering, in situ product removal, and multi-enzyme cascade optimization. This review aims to provide systematic theoretical references and technical insights for the green and efficient biomanufacturing of amino alcohols. Full article

Carnobacterium maltaromaticum is a lactic acid bacterium with growing applications in food biopreservation, probiotics, and microbial time-temperature integrators for tracking food quality throughout the cold chain. To develop efficient, ready-to-use dried concentrates for these applications, this study evaluated the impact of different protective formulations on the freeze-drying and storage stability of C. maltaromaticum CNCM I-3298 and explored the underlying molecular mechanisms. The formulations included sucrose, trehalose, and trehalose combined with maltodextrins. Sodium ascorbate was added to the most promising formulations for its potential antioxidant effect. Specific acidifying activity measurements before and after freezing, after freeze-drying and during storage at 25 °C revealed a gradual loss of bacterial activity following freeze-drying and storage. Sucrose, and trehalose with sodium ascorbate provided the best and outstanding protection. Increasing the glass transition temperature using trehalose or trehalose–maltodextrin matrices did not improve stability at 25 °C. Based on prior studies of proteins, we hypothesized that fast relaxation dynamics contribute to the degradation of cells in the glassy state. Fourier transform infrared micro-spectroscopy revealed that freeze-drying primarily affected nucleic acids, proteins (amide I and II), and cell wall components. Storage caused minor additional changes. First results relating to sodium ascorbate’s positive effect when added to trehalose and some spectral features in the fingerprint region need further investigation. Full article

Background: The endocannabinoid system (ECS) and the Kisspeptin system (KS) play crucial roles in the central and peripheral regulation of male reproduction. The KS comprises Kisspeptins, the cleavage product of the Kiss1 protein, and its receptor Kiss1R; it is a critical central regulatory factor of the Gonadotropin Releasing Hormone (GnRH), but its role in the testis in sustaining spermatogenesis is not fully understood. Similarly, in addition to the brain, the ECS is widely expressed in the testis, where it regulates spermatogenesis, steroidogenesis, and the production of high-quality gametes. Since the possible crosstalk between KS and ECS at the gonadal level is poorly understood, this study investigates the possible mutual modulation between ECS and KS in rat testis. Methods: Experiment 1: Testis pieces collected from adult rats were treated ex vivo for 1 h with the endocannabinoid anandamide (AEA, 10⁻⁸ M) ± SR141716A (10⁻⁷ M, a cannabinoid receptor (CB) 1 antagonist), or with SR141716A alone. Experiment 2: Testis pieces were treated for 4 h with decreasing doses of Kisspeptin-10 (Kp10, 10⁻⁶–10⁻⁹ M) ± Kp234 (a Kiss1R antagonist). Proteins extracted from the treated tissues were analyzed by Western blot for Kiss1R, Kiss1, CB1, CB2, AEA-hydrolyzing enzyme Fatty Acid Amide Hydrolase (FAAH), and AEA-biosynthetic enzyme N-acylphosphatidylethanolamine-specific phospholipase D (NAPE-PLD) proteins. Results: AEA treatment, via CB1, reduced Kiss1R protein in testis. Kp10 treatment increased the expression of CBs and NAPE-PLD at all doses and increased FAAH at 10⁻⁹ M dose only. Pre-incubation with Kp234 abolished Kp10 effects on CB1, NAPE-PLD, and FAAH, suggesting a direct Kp10-dependent modulation; on the other hand, pre-incubation with Kp234 did not abolish Kp10’s effects on CB2, suggesting an indirect action of Kp10 on CB2. Conclusions: Mutual modulation between ECS and KS exists in the testis: AEA, via CB1, suppresses Kisspeptin signaling, while Kisspeptin regulates the ECS through both Kiss1R-dependent and independent mechanisms. These local interactions identify new potential mechanisms in the intratesticular communications sustaining spermatogenesis via ECS and suggest that KS might be a new therapeutic target to rescue ECS impairment in male reproductive dysfunction. Full article

Although estrogen has been identified to play crucial roles in the development of melasma, the exact mechanism of estrogen’s effect on pigmentation is incompletely elucidated. Recent studies have highlighted the pivotal role of immune cells in melasma. Interestingly, infiltrated macrophages are significantly enhanced in melasma lesions. Estrogen could facilitate M2 polarization. However, whether estrogen could stimulate melanogenesis via skewing M2 phenotype remains unknown. This study attempted to determine the significance and molecular mechanism of estrogen-induced M2 phenotype in melasma. We found that M2 infiltration was significantly increased in melasma lesions compared with perilesional skin. Arginase 1 was identified as the hub gene, and its expression was positively correlated with that of microphthalmia-associated transcription factor and tyrosinase-related protein 1 in melasma through transcriptome analysis. Moreover, β-estradiol (E2) was confirmed to promote M2 skewing while inhibiting M1 polarization via activating STAT6 signaling. Importantly, E2-induced M2 polarization robustly increased melanogenesis by increasing tyrosinase activity and expression of microphthalmia-associated transcription factor and tyrosinase in melanocytes, which were profoundly inhibited by VEGF knockdown or antagonism both in vitro and in ex vivo skin. Furthermore, VEGF was revealed to enhance melanogenesis through activating p38 MAPK and ERK1/2 signaling pathways in melanocytes. Additionally, dermal VEGF was significantly increased, and most of it colocalized with M2 macrophages in melasma lesions. Crucially, E2 administration potently reversed ovariectomy-decreased M2 skewing and subsequently promoted dermal VEGF expression and epidermal melanogenesis in the mouse tail skin, which were significantly suppressed by macrophage depletion. These findings suggest that estrogen may stimulate melanogenesis in melasma through increasing M2 skewing and VEGF expression and secretion in macrophages. Full article

The protective effect of Compound terminalia chebula extract (HL) against colonic injury induced by Porcine epidemic diarrhea virus (PEDV) infection in neonatal piglets remains unclear. This study aimed to evaluate the mitigating effects of HL on PEDV-induced colonic injury and elucidate the underlying mechanisms. Eighteen 7-day-old Duroc × Landrace × Large White piglets (2.58 ± 0.05 kg) were randomly assigned to three groups (n = 6/group): CON (blank control), PEDV (infected), and HL + PEDV (HL-supplemented + infected). The 11-day trial included 3 days of acclimatization (days 0–3) and an 8-day experimental period (days 4–11). HL (10 mg/kg BW) was orally administered daily to the HL + PEDV group. On day 8, PEDV and HL + PEDV groups were challenged with 3 mL PEDV (3 × 10⁶ TCID₅₀/mL), while CON received Dulbecco’s Modified Eagle Medium (DMEM). All piglets were euthanized on day 11 for colonic tissue collection. Results indicated that PEDV infection induced colonic injury, manifested by a significant increase in crypt depth and disruption of intestinal homeostasis. This was evidenced by impaired barrier integrity (upregulation of matrix metalloproteinase-7 gene [MMP7] and matrix metalloproteinase 13 gene [MMP13], mucus disorganization (elevation of mucin 5AC gene [MUC5AC]), oxidative stress (reduced catalase [CAT] activity and increased malondialdehyde [MDA] levels in serum and colon), and inflammation (upregulation of regenerative islet-derived protein 3γ gene [REG3G], S100 calcium-binding protein A8/A9 gene [S100A8/A9], and interleukin-1β gene [IL-1β]). Additionally, PEDV impaired colonic ion transport by downregulating calcium channel genes (Transient Receptor Potential Cation Channel Subfamily V Member 6 gene [TRPV6], Transient Receptor Potential Cation Channel Subfamily M Member 6 gene [TRPM6]). Notably, HL supplementation effectively reversed these adverse effects. HL restored colonic morphology, increased CAT activity, reduced MDA accumulation, and suppressed inflammatory gene expression. Furthermore, HL modulated the expression of genes involved in water and ion transport upregulating Aquaporin 7 gene (AQP7), Chloride Channel Accessory 4 gene (CLCA4), Sodium-Hydrogen Exchanger 3 gene (NHE3), Transient Receptor Potential Vanilloid 6 (TRPV6), and Transient Receptor Potential Melastatin 6 gene (TRPM6) and significantly inhibited PEDV replication, as indicated by the downregulation of the transcription levels of PEDV membranegene (M), nucleocapsid gene (N), and spike gene (S). Taken together, HL alleviates PEDV-triggered colonic tissue damage in suckling piglets via improving colonic antioxidant capacity, mitigating inflammatory response, partially regulating intestinal barrier and ion/water transport-related genes, and downregulating the transcription of PEDV structural genes at molecular and histological levels. Full article

The outbreak of coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has emerged as one of the most significant global health crises in recent history. Coronaviruses are a diverse group of RNA viruses classified into alpha, beta, gamma, and delta genera, with SARS-CoV-2 belonging to the beta-coronavirus family. The virus exhibits high transmissibility and causes a wide spectrum of clinical manifestations ranging from mild respiratory symptoms to severe complications such as acute respiratory distress syndrome, multi-organ failure, and death, particularly among elderly and immunocompromised individuals. Structurally, SARS-CoV-2 possesses a large single-stranded RNA genome encoding major structural proteins, including spike (S), envelope (E), membrane (M), and nucleocapsid (N) proteins, which play critical roles in host-cell recognition and viral infection. Understanding the molecular mechanisms of virus–host interactions, especially protein–protein interactions (PPIs), is essential for uncovering viral pathogenesis and identifying potential therapeutic targets. Traditional experimental techniques for PPI detection, such as yeast two-hybrid and affinity purification methods, are often expensive, labor-intensive, and prone to inaccuracies. Consequently, computational approaches based on machine learning (ML) and deep learning (DL) have gained significant attention for efficient and scalable PPI prediction. These methods use diverse biological information, including protein sequences, structural features, genomic data, Gene Ontology annotations, and interaction networks, to model complex biological relationships. This survey reviews computational approaches to PPI prediction, highlighting ML- and DL-based techniques, methodological advances, performance evaluation practices, and limitations that affect benchmark comparability. It also discusses biological databases and data sources commonly used in PPI studies and explicitly considers how models trained in coronavirus-centered settings may generalize to other viral families with different mechanisms of host interaction. Full article

The sodium-coupled citrate transporter NaCT (SLC13A5) imports extracellular citrate into cells. In the CNS, SLC13A5 is described to be expressed predominantly in neurons. Cytosolic citrate levels rely on citrate generated in mitochondria and imported from other CNS cells, regulating intermediary metabolism and supplying acetyl-CoA for lipid synthesis and histone acetylation. Despite evidence for NaCT’s role in neurometabolic homeostasis, its transcriptional behavior across Alzheimer’s disease (AD) progression and across astrocyte subtypes remains uncharacterized at single-cell resolution. We analyzed single-nucleus RNA sequencing data from 1,378,211 nuclei across 84 donors in the Seattle Alzheimer’s Disease Brain Cell Atlas (SEA-AD) Middle Temporal Gyrus dataset to profile SLC13A5 and seven citrate metabolism genes across a continuous AD pseudoprogression score. SLC13A5 expression was restricted to astrocytes (~20% prevalence) and concentrated in the Astro 2 supertype (24.0%), a homeostatic subtype characterized by low C3 (1.6%) and CD44 (5.5%), which expanded with pseudoprogression (Spearman rho = +0.345, FDR < 0.001). The A1-reactive Astro 3 supertype, where SLC13A5 prevalence was 0.87%, declined concordantly (rho = −0.393). Opposing compositional and transcriptional forces produced apparent stability in overall SLC13A5 prevalence. SLC13A3 and ACO1 showed progressive donor-level declines correlating with Braak stage and Thal phase (rho range: −0.307 to −0.349, FDR < 0.01). APOE4 carriers exhibited lower SLC13A5 prevalence specifically within Astro 2 nuclei (median 17.6% vs. 25.9%; Wilcoxon p = 0.025), though this association did not survive multivariate regression. No difference in Astro 2 SLC13A5 expression was detected between cognitively resilient and expected-AD donors with equivalent high Braak burden (p = 0.888). Contrary to the prevailing description of NaCT as a neuronal transporter, SLC13A5 transcript in the SEA-AD MTG dataset was detected almost exclusively in astrocyte nuclei, concentrated in the homeostatic Astro 2 subtype, and maintained as this subtype expanded with advancing AD pathology. Because these are nuclear transcript measurements, they delimit where SLC13A5 mRNA is detectable rather than establishing the cellular site of NaCT protein or activity, which requires in situ validation. Full article

Glycosylation is the most common post-translational modification in the human proteome, with over half of all human proteins bearing covalently attached glycans. These glycan structures direct protein folding through ER quality control machinery, shield polypeptides from proteolytic degradation, regulate circulatory half-life via the asialoglycoprotein receptor, and serve as molecular signals for immune recognition and intracellular trafficking. For biopharmaceuticals, which constitute a rapidly growing share of approved drugs, glycan profiles are critical quality attributes that directly determine clinical efficacy and safety. Yet achieving the correct glycosylation on a therapeutic protein remains one of the field’s central challenges, as glycan biosynthesis is non-template-driven and highly sensitive to expression system and manufacturing conditions. This review connects the biological functions of glycosylation to the practical strategies of glycoengineering, examining how sequence design, expression system selection, and downstream enzymatic remodeling are used to optimize therapeutic glycoproteins. Clinical case studies spanning monoclonal antibodies, cytokines, and enzyme replacement therapies illustrate how glycan engineering translates into improved patient outcomes. We conclude by surveying emerging technologies poised to make precisely glycosylated therapeutics more accessible. Full article

Whole-plant soybean (WPS) is a high-protein forage resource, but its natural ensiling is often unsatisfactory due to low water-soluble carbohydrate content and high buffering capacity. This study investigated the effects of exogenous melatonin (ME) at 0 (CK), 5 (ME1), 10 (ME2), and 20 (ME3) mg/kg fresh matter on fermentation quality, chemical composition, in vitro rumen fermentation, and bacterial community structure of WPS silage. ME2 and ME3 had lower pH values and higher lactic acid contents than CK, with both treatments achieving pH values below 4.2. Crude protein concentration increased from 15.42% in CK to 19.96% in ME3, while neutral detergent fiber was lower in all ME treatments, and acid detergent fiber was lower in ME2 and ME3 than in CK. At 36 h, no overall treatment effect was detected for cumulative gas production, whereas in vitro dry matter digestibility differed only between ME2 and ME3. 16S rRNA gene sequencing revealed that ME altered the bacterial community, with community-weighted rrn copy number elevated in ME2 and ME3. Random forest analysis identified Enterococcus as the genus with the highest importance for treatment classification, and functional predictions indicated higher predicted abundances of amino acid biosynthesis pathways in ME treatment groups. These results indicate that ME has potential as an additive for improving WPS silage fermentation, but practical dosage recommendations require further validation through aerobic stability, animal performance, economic, and safety assessments. Full article

Ulomoides dermestoides (Yangchong) is a tenebrionid beetle used in traditional medicine across Asia and Latin America. While crude extracts show effects on inflammation, oxidative stress, and other conditions, systematic integration of its bioactive substances, mechanisms, and translational potential is lacking. This review consolidates its chemical basis, comprising volatile benzoquinones, terpenes, and alkenes, alongside non-volatile fatty acids, proteins (antioxidant enzymes, glycoproteins), and phenolics. Pharmacological evidence indicates multi-target modulation of reactive oxygen species (ROS), cytokines, leukocyte recruitment, endothelial activation, and thromboinflammation. Recent advances include proteomic identification of antioxidant protein complexes, neuroprotection in a Parkinson’s disease model, chromosome-level genome assembly, and isolation of the UDP-glucose pyrophosphorylase 2a (UGP2A) glycoprotein, which alleviates thrombosis partly via toll-like receptor 4/myeloid differentiation primary response 88 (TLR4/MyD88)-mediated endothelial anti-inflammatory effects. However, most evidence remains preclinical, relying on non-standardized crude extracts, and benzoquinone-containing fractions display potential cytotoxicity and genotoxicity. Future research should integrate bioassay-guided isolation, structural characterization, multi-omics, pharmacokinetic/pharmacodynamic (PK/PD) analysis, standardized quality markers, and rigorous safety evaluation to transform U. dermestoides from an empirical insect-derived medicinal resource into a scientifically validated source of preclinical antioxidant and anti-inflammatory candidate substances. Full article

Objectives: To assess the feasibility and reproducibility of predicting antimicrobial resistance (AMR) in Escherichia coli from MALDI-TOF mass spectrometry data using a standardized, open-source machine learning (ML) workflow, we systematically compared four ML algorithms, evaluated the impact of culture conditions, extract storage, and spectral preprocessing on model performance, and validated results through nested cross-validation with statistical significance testing. Methods: A total of 282 clinical E. coli isolates were analyzed. Two MALDI-TOF MS datasets were generated from freshly cultured extracts (T₁) and recultured isolates one year later (T₃), yielding 4468 spectra. A third dataset from the T₁ extracts stored at −20 °C for one year (T₂) was evaluated for spectral stability but excluded from primary modeling likely due to storage-induced degradation. Protein spectra (m/z 2000–15,000) were preprocessed using an in-house developed MALDI-TOF preprocessing pipeline (MTPP) comprising variance stabilization, Savitzky–Golay smoothing, SNIP baseline correction, TIC normalization, LOWESS alignment, and MAD-based peak detection (SNR ≥ 3), yielding 121 m/z features. Four classifiers—Random Forest (RF), Logistic Regression, Support Vector Machine, and Gradient Boosting—were trained to predict resistance to 11 antibiotics using nested cross-validation: outer GroupShuffleSplit (5-fold, isolate-level) for evaluation and inner GroupKFold for recursive feature elimination (RFECV) and hyperparameter tuning (RandomizedSearchCV). Classification thresholds were optimized via the precision–recall curve. Model performance was assessed using AUROC, AUPRC, F1-score, Matthews Correlation Coefficient (MCC), and bootstrap 95% confidence intervals (1000 replicates). Pairwise model comparisons were tested with McNemar’s chi-squared test. Results: Among the 12 antibiotics included in the analysis (meropenem excluded for absence of resistance), resistance prevalence ranged from 1.1% (colistin) to 59.9% (amoxicillin). Colistin was subsequently also excluded from ML modeling due to insufficient resistant isolates (n = 3), leaving 11 antibiotics for prediction. The best predictive performance was observed for ciprofloxacin (AUROC 0.76 [95% CI 0.74–0.77]; F1 0.54; MCC 0.38) and ceftazidime (AUROC 0.68 [0.65–0.71]; F1 0.36; MCC 0.29), using 13 and 37 RFECV-selected features, respectively. Amoxicillin achieved the highest F1-score (0.76), driven by high recall (0.98) but modest AUROC (0.58). No meaningful predictive signal was detected for amikacin, cefepime, or tigecycline (AUROC ≤ 0.57, F1 ≤ 0.17), attributable to extreme class imbalance, and no robust multi-peak resistance signature was detected in this dataset. McNemar’s test confirmed that RF significantly outperformed Logistic Regression for all antibiotics (p < 0.01), while Gradient Boosting performed comparably to RF for ciprofloxacin (p = 0.17) and ceftazidime (p = 0.28). Frozen extracts (T₂) produced lower spectral similarity and were excluded from model training; the aligned T₁₊₃ dataset yielded the most stable performance across metrics. Conclusions: Machine learning analysis of MALDI-TOF spectra enables reproducible AMR prediction for selected antibiotics in E. coli, with ciprofloxacin and ceftazidime showing the strongest signal. Nested isolate-level cross-validation, multi-model comparison with statistical testing, and open-source code provide a transparent, reproducible foundation for integrating ML-assisted MALDI-TOF analysis into diagnostic AMR surveillance. Extract storage at −20 °C degrades spectral quality and should be avoided in ML training workflows. Full article

Background/Objectives: Cow’s milk protein allergy (CMPA), one of the most common allergies in early life, can present psychological, financial, and social challenges for caregivers. For mothers, this burden may be compounded by the fact that experiences with pediatric CMPA typically coincide with the perinatal period, which itself may be challenging. Our study aimed to explore the concerns, experiences, and needs of mothers navigating pediatric CMPA. Methods: We conducted a qualitative study involving three groups: mothers of children (18 months to 4 years) with, or who previously had, CMPA; mothers of infants (<18 months) with CMPA; and pregnant women concerned about their baby developing CMPA. All mothers completed a demographic questionnaire and participated in a virtual focus group or interview that was recorded, transcribed verbatim, and analyzed according to reflexive thematic analysis. Questionnaire data were described (n/N, %) to summarize participant characteristics. Results: In total, 16 mothers participated. Three themes were identified: (1) perceived negative psychosocial impacts, (2) perceived inadequacy of support from healthcare professionals, and (3) perceived negative dietary and financial implications. Conclusions: This study provides valuable insights into the perceived psychosocial implications and unmet management needs of CMPA. Full article

Mitochondria-targeting metal complexes (MTMCs) are a mechanistically distinct class of metallopharmaceuticals. Unlike first-generation platinum drugs that form nuclear DNA adducts, MTMCs exploit organelle-specific vulnerabilities such as hyperpolarised mitochondrial membrane potential (ΔΨm), elevated reactive oxygen species (ROS), limited mitochondrial DNA (mtDNA) repair capacity, and redox-dependent enzymes such as thioredoxin reductase (TrxR). We systematically searched PubMed, Web of Science, Scopus, and Google Scholar databases for studies published between 2016 and 2026, applying predefined inclusion criteria that included subcellular localization evidence and functional bioenergetic endpoints. The search identified 147 studies covering Pt(II/IV), Ru(II/III), Au(I/III), Ir(III), Os(II), Re(I), and V(IV/V) complexes and metal–organic framework nanoplatforms. Mechanistic evidence converges on four intramitochondrial target categories: inhibition of ETC (Electron Transport Chain) Complexes I/III with consequent ATP depletion; ROS overproduction, coupled with glutathione and TrxR depletion; outer mitochondrial membrane permeabilization and intrinsic apoptotic cascade activation; and mtDNA damage within a compartment limited to base excision repair. Multi-modal cell death—the co-occurrence of apoptosis, ferroptosis, necroptosis, and autophagic cell death—was a recurrent finding across the reviewed studies. This review thoroughly surveys the latest trends in MTMC drug design (metals, ligand structures, and mechanisms of action) and summarises analytical techniques for speciation, pharmacokinetics, safe monitoring, and resistance, while critically analysing translational barriers and clinical failures. To address the field’s inconsistent terminology, we introduce an explicit localization evidence hierarchy that distinguishes mitochondria-targeting complexes (through quantitative ICP-MS fractionation or co-localization with defined Pearson/Manders coefficients) from simply mitochondria-localising or mitochondria-perturbing agents, and we apply it throughout. We also point out that the idea of selectivity being purely driven by membrane voltage (ΔΨm) and thermodynamics is constrained by membrane and protein binding, as well as the transmembrane pH gradient, kinetic limitations, and demonstrated heterogeneity of cancer-cell membrane potential, and, as such, the functional mitochondrial effects must not be equated with mitochondrial accumulation. Since elemental quantification cannot distinguish intact complex from protein adducts and decomposition products, speciation-aware pharmacokinetics emerges as a prerequisite for a credible exposure–response interpretation. The translational progress will depend less on new chemotypes than on this analytical and pharmacokinetic rigour, together with organelle-level safety monitoring and biomarker-guided patient selection. Full article