Search Results (338)

Procambarus clarkii and Macrobrachium nipponense are two freshwater shrimp species used in rice-farming systems. To guide their cultivation in saline–alkaline waters, two 96 h experiments were conducted on juvenilels of each species using 540 juveniles per species (initial body length: 1.51 ± 0.16 cm for P. clarkii and 0.88 ± 0.03 cm for M. nipponense): combined salinity–pH stress (0/15.0/25.0‰ at pH 7.4/9.0/10.0) and NaHCO₃ alkalinity stress (0/10/20 mmol/L). Under salinity–pH stress, survival of P. clarkii was 100%, 72.23%, and 53.33%, respectively; for M. nipponense, it was 93.33%, 61.13%, and 23.33%. Under alkalinity stress, survival of P. clarkii was 92.22%, 82.22%, and 61.11%; for M. nipponense, it was 91.11%, 65.55%, and 46.67%. In both species, superoxide dismutase, acid phosphatase, and alkaline phosphatase decreased while malondialdehyde increased with stress intensity. Metabolomics revealed species-specific reprogramming: P. clarkii upregulated protective lipids (e.g., glycerophosphoethanolamines, fatty acid esters), whereas M. nipponense showed depletion of critical osmolytes (glycerophosphocholines) and accumulation of apoptosis-related ceramides. KEGG analysis confirmed that energy metabolism, amino acid homeostasis, and ABC transporters were primary pathways affected. In conclusion, extreme stress significantly reduced survival, suppressed immunity, and triggered metabolic reprogramming in both species, with P. clarkii showing substantially higher tolerance. For cultivation, P. clarkii is preferred in moderately high saline–alkaline waters, while M. nipponense requires low-alkalinity freshwater with strict monitoring. These findings support species-specific management of saline–alkaline rice–shrimp systems. Full article

Background: Low maternal folate status is associated with placental dysfunction and adverse pregnancy outcomes; however, the mechanisms linking reduced folate availability to altered placental function remain incompletely understood. We investigated whether folate deficiency directly alters trophoblast function and microRNA (miRNA) expression, and whether folate-responsive miRNAs mediate these functional changes. Methods and Results: Human placental villous explants, BeWo choriocarcinoma cells, and primary human cytotrophoblasts were cultured under physiological or folate-deficient conditions to assess the direct impact of reduced folate availability. Although intracellular folate depletion was achieved in all models, only primary cytotrophoblasts reproduced functional changes consistent with those observed in placentas from folate-deficient pregnancies, exhibiting increased apoptosis and reduced system A amino acid transport. Of sixteen miRNAs previously associated with low maternal folate status, miR-30e-3p and miR-34b-5p were significantly reduced in trophoblast following folate depletion. Targeted inhibition of either miRNA did not alter apoptosis or system A activity. Pathway analysis of differentially expressed genes following miRNA inhibition identified processes related to cytoskeletal organisation, cell adhesion, PI3K/AKT and MAPK signalling. Conclusions: Folate deficiency directly impairs trophoblast survival, amino acid transport, and miRNA expression in primary trophoblasts. Our findings demonstrate that only a subset of folate-associated placental miRNAs respond directly to folate depletion and that inhibition of individual folate-responsive miRNAs is insufficient to reproduce the trophoblast phenotype. These results indicate that trophoblast adaptation to reduced folate availability is likely mediated through coordinated nutrient-sensitive regulatory networks rather than individual miRNAs acting in isolation. Full article

Fungal nitrogen metabolism is a central determinant of yeast growth, fermentative performance, and secondary metabolism in fungi associated with fermented environments. For Saccharomyces cerevisiae, the assimilation of nitrogen sources found in grape must, including ammonium, free amino acids, and peptides, has been widely characterized, establishing a consumption hierarchy in which proline is considered a non-preferential nitrogenous source. However, the regulation and hierarchy of nitrogen-source utilization in non-conventional fungi remain poorly characterized, particularly in yeasts adapted to anthropized fermentative niches. In this context, Brettanomyces bruxellensis represents a useful fungal model to study the different nitrogen sources that are used, strain-dependent physiology, and survival under nutrient-limited fermentative conditions. We hypothesized that apparent depletion of amino acid and the expression of selected amino acid permease genes are strain-dependent traits linked to the survival of B. bruxellensis. In this study, we evaluated the strain-dependent physiology and amino acid depletion patterns of two B. bruxellensis strains from wine (LAMAP2480 and LAMAP1359). In both cases, the highest apparent depletion values under the 20 amino acid condition were observed for arginine, glutamine, tryptophan and proline, indicating that these compounds contributed substantially to the organic nitrogen pool under the assayed conditions. Only LAMAP2480 isolate was able to grow in the condition without added amino acids, indicating strain and nitrogen source dependence under limited organic nitrogen availability. Transcriptional analysis of GAP1, GNP1, and TAT1 permeases showed expression patterns dependent on both the strain and the available nitrogen source. This is the first study to combine the evaluation of physiological performance, amino acid consumption, apparent nitrogen depletion derived from amino acids normalized to OD₆₀₀ (OD-AA-N depletion), and the transcriptional responses of selected amino acid permease genes. This knowledge may contribute to understanding the survival of B. bruxellensis in fermentation environments with limited nutritional resources. Full article

Parkinson’s disease (PD) is characterized by progressive dopaminergic degeneration and maladaptive motor cortical plasticity. However, the cellular pathways underlying cortical surface activity in the primary motor cortex (M1) remain unclear, despite serving as a potential target for electrotherapy. We investigated the excitatory–inhibitory (E-I) balance and synaptic plasticity of superficial M1 circuits in a unilateral 6-hydroxydopamine (6-OHDA)-induced rat model of PD. Using extracellular local field potential and whole-cell patch recordings from the contralateral and ipsilateral M1 hemispheres of hemi-parkinsonian rats, we observed a significantly elevated field excitatory postsynaptic potential (fEPSP) input–output function but unchanged intrinsic neuronal excitability in the M1 superficial layer. An altered relative contribution between alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR)- and N-methyl-D-aspartate receptor (NMDAR)-mediated transmission was reflected by a significantly increased AMPA/NMDA ratio. Markedly reduced inhibitory synaptic tone was also evidenced by the decreased amplitude and frequency of spontaneous inhibitory postsynaptic currents (sIPSCs), supporting an E-I imbalance favoring excitation in PD. Furthermore, group I metabotropic glutamate receptor (mGluR_1/5)-dependent long-term depression (LTD) was abolished in the ipsilateral PD hemisphere, whereas NMDAR-dependent LTD remained intact. In summary, dopamine depletion appears to enhance network excitation and disrupt mGluR_1/5-mediated control of M1 surface circuitry. Our findings identify altered cortical surface mGluR-dependent plasticity in the hemi-parkinsonian model; however, the relationship between these electrophysiological alterations and individual motor outcomes remains to be determined. Full article

Background/Objectives: Mesoporous silica nanoparticles (MSNs) are widely investigated as nanocarriers for drug delivery, gene transfer, and bioimaging. However, the mechanisms underlying their size-dependent cytotoxicity at the metabolic level remain incompletely understood. This study aimed to determine whether different-sized MSNs induce distinct patterns of subcellular injury and metabolic reprogramming in lung epithelial cells. Methods: A549 cells were exposed to 80 nm and 600 nm MSNs at 50 and 200 μg/mL for 24 h. Ultrastructural changes were examined by transmission electron microscopy (TEM). Intracellular reactive oxygen species (ROS) and Ca²⁺ were measured by 2′,7′-dichlorodihydrofluorescein diacetate (DCFH-DA) and Fluo-4 AM fluorescence, respectively. Inflammatory gene expression (IL1B, IL6, TNFA, HIF1A) was quantified by reverse transcription quantitative polymerase chain reaction (RT-qPCR). Untargeted metabolomics were performed using combined gas chromatography–mass spectrometry (GC-MS) and liquid chromatography–mass spectrometry (LC-MS) platforms, followed by principal component analysis (PCA), partial least squares discriminant analysis (PLS-DA), and MetaboAnalyst-based pathway enrichment. Results: TEM revealed distinct size-dependent subcellular distributions: 80 nm MSNs were predominantly associated with mitochondrial abnormalities, including cristae disruption, swelling, and mitophagy-like features, whereas 600 nm MSNs accumulated in endocytic vesicles with membrane disruption. Metabolomic profiling showed that 80 nm MSNs were associated with TCA cycle blockade—characterized by the accumulation of early intermediates (citrate, oxaloacetate) and the depletion of distal intermediates (fumarate, malate)—with compensatory glycolytic activation (increased glyceraldehyde-3-phosphate and pyruvate) and reduced deoxynucleotide pools (dCDP, dUMP). By contrast, 600 nm MSNs triggered broad nucleotide triphosphate accumulation (ATP, CTP, dGTP, dCTP), amino acid depletion, and robust inflammatory activation, including a ~136-fold increase in IL1B expression and HIF1A transcriptional upregulation. PCA and PLS-DA confirmed distinct size-dependent metabolic phenotypes. Conclusions: MSN size strongly influences subcellular targeting—80 nm particles were predominantly associated with mitochondrial injury while 600 nm particles disrupted endocytic vesicles—driving qualitatively distinct patterns of metabolic reprogramming and inflammatory signaling. These findings establish a correlative mechanistic framework linking particle size to organelle-specific injury and provide candidate metabolic markers for nanotoxicological evaluation. Full article

Improper disposal of coffee-processing by-products can cause environmental pollution, greenhouse gas emissions, and resource loss, whereas their reuse in coffee plantations may support sustainable production. This review systematically examines the material properties, stabilization methods, field application pathways, agronomic effects, quality responses, and environmental risks of coffee-pulp-type by-products in cultivation. Relevant studies published up to June 2026 were retrieved from Web of Science, Scopus, ScienceDirect, SpringerLink, Google Scholar, and CNKI and qualitatively synthesized along the soil–plant–quality continuum. Current evidence suggests that properly stabilized materials, applied at appropriate rates, can improve soil organic matter, structure, water and nutrient retention, microbial activity, plant growth, photosynthesis, and crop yield in plantations. They may also indirectly influence green bean quality by regulating sugars, amino acids, chlorogenic acids, and caffeine. However, these effects depend strongly on material properties, maturity, application rate, coffee genotype, soil and climatic conditions, and management practices. Excessive or insufficiently decomposed materials may cause soil acidification, phytotoxicity, oxygen depletion, nutrient imbalance, and yield–quality trade-offs. Overall, recycling within plantations can turn processing waste into farm inputs, reinforce on-farm carbon and nutrient cycles, ease disposal burdens, and advance BCG and wider circular-economy principles in practice. Full article

Metabolic reprogramming constitutes a fundamental hallmark of malignancy, orchestrating a hostile tumor microenvironment (TME) that severely compromises anti-tumor immunity. Despite the transformative success of immune checkpoint blockade and adoptive cell therapies, clinical efficacy is frequently curtailed by the metabolic barriers imposed by the TME. This review systematically elucidates the complex metabolic interplay between tumor cells and infiltrating T cells, highlighting two defining mechanisms driving immune evasion: the competitive sequestration of essential nutrients and the accumulation of immunosuppressive oncometabolites. We detail how the depletion of glucose and critical amino acids (glutamine, arginine, methionine, etc.) imposes a state of “metabolic siege” on T cells, impairing their bioenergetics and effector functions. Concurrently, we explore how accumulated metabolites—such as lactate, succinate, 2-hydroxyglutarate, kynurenine, and lipids—function as non-canonical signaling molecules to subvert immune surveillance via epigenetic remodeling and oxidative stress. Furthermore, we synthesize emerging therapeutic strategies designed to dismantle this metabolic barrier, including targeting metabolic enzymes (IDO1 and FASN) and transporters, repurposing metabolic waste, and genetically engineering T cells with enhanced metabolic fitness and resilience. By integrating the latest insights into the “metabolism–epigenetics–immunity” axis, this review provides a theoretical foundation for developing next-generation immunotherapies that target metabolic vulnerabilities to overcome resistance in cancer treatment. Full article

Exposure to stressful low temperatures during development can cause chilling injury, leading to impaired physiological performance. In insects, chilling injury is often associated with metabolic imbalance, oxidative stress and disruption of energy homeostasis, which can collectively compromise survival and growth. Because Tuta absoluta (Meyrick, 1917) is a tomato pest adapted to warm environments, we hypothesized that low-temperature exposure would induce chilling injury by disrupting metabolism and cellular function. We investigated the responses of T. absoluta larvae to three thermal regimes (25, 15 and 5 °C) over a 7-day period, using integrated physiological, metabolomic and transcriptomic analysis. Low-temperature stress reduced survival and feeding performance, accompanied by suppressed digestive enzyme activities (α-amylase, lipase and trypsin) and depletion of glycogen reserves, indicating impaired energy acquisition. In contrast, increased trehalose and proline accumulation suggested a shift toward protective metabolism. Importantly, low temperature induced a pronounced decoupling of energy metabolism and redox homeostasis, characterized by reduced antioxidant capacity (peroxidase; POD and superoxide dismutase; SOD) and elevated levels of reactive oxygen species (ROS). Metabolomic and transcriptomic analysis of stressed larvae revealed alterations in amino acid and carbohydrate metabolism, showing differential regulation of the genes involved in energy production, oxidative stress responses and growth. Integrative analysis demonstrated that metabolic reprogramming and transcriptional regulation are tightly linked under low-temperature conditions, revealing a resource allocation trade-off between growth and stress defense. Together, these findings identify metabolic and redox imbalances as mechanisms underlying cold-induced physiological decline, providing new insight into how low temperature constrains insect performance. Full article

Cisplatin is an effective platinum-based chemotherapeutic agent used to treat a variety of cancers. However, its clinical utility is limited by dose-dependent neurotoxicity, yet no approved neuroprotective strategy currently exists. Our integrated cellular, metabolic, and in vivo approaches unraveled the neuroprotective potential of Areca catechu ethyl acetate extract (AC-EA) against cisplatin-induced neurotoxicity. Importantly, AC-EA did not reduce cisplatin-induced cytotoxicity in A549 lung cancer cells. In HT22 hippocampal neurons, AC-EA restored cell viability, suppressed reactive oxygen species generation, preserved mitochondrial-associated fluorescence, and attenuated phosphorylated histone H2AX (γH2AX)-marked DNA damage. AC-EA was associated with increased pNRF2 expression, consistent with activation of NRF2-dependent antioxidant signaling, suppressed inducible nitric oxide synthase iNOS (inducible nitric oxide synthase )-mediated neuroinflammation, and prevented the depletion of total AKT (protein kinase B) protein. Untargeted metabolomics and Caenorhabditis elegans survival assays were performed for mechanistic and in vivo validation. Metabolomics data showed restoration of several critical amino acids, including L-tyrosine and β-alanine, disrupted by cisplatin. Moreover, C. elegans studies confirmed in vivo activation of antioxidants via the SKN-1/GST-4 (glutathione S-transferase 4) pathway. While AC-EA shows neuroprotective potential, arecoline’s toxicity demands caution. To our knowledge, this is the first study to demonstrate the neuroprotective activity of A. catechu against cisplatin-induced neurotoxicity, laying the foundation for developing plant-derived adjunct therapies for chemotherapy-associated neuropathy. Full article

Developmental regression, the loss of previously acquired language and social skills during the second year of life, affects 20–40% of children with autism spectrum disorder (ASD), yet its metabolic underpinnings remain poorly defined. Existing metabolomics studies have focused on amino acid and acylcarnitine alterations, leaving the eicosanoid, sphingolipid, and glycoconjugate axes largely unexamined. Plasma from 25 children with regressive ASD (REG+), 27 with non-regressive ASD (REG−), and 21 typically developing controls (aged 2–6 years) was profiled using untargeted Q-TOF LC/MS (Agilent 6530, ESI+ mode, 100–1700 m/z). From 6657 detected features, a stepwise curation pipeline combining statistical significance (raw p < 0.05 with Benjamini–Hochberg FDR correction, q < 0.05; FC > 1.5), analytical plausibility, endogenous origin verification, and literature-based directional alignment yielded a prioritized set of 14 annotated metabolic features. Exploratory PLS-DA (Partial Least-Squares Discriminant Analysis) visualization showed separation among the three groups within the present dataset; however, diagnostic or predictive performance was not evaluated. The 14-feature panel clustered along four biochemical axes. A feature putatively annotated as prostaglandin E3 (PGE3) showed a 7.13-fold reduction in REG+ versus controls (1.58-fold in REG−; FC REG+/REG− = 4.52). N-Acetylneuraminosyl-(α2-6)lactosamine and aspartylglycosamine were decreased 4.44-fold and 5.42-fold in REG+, respectively, with regression-specific amplification (FC REG+/REG− > 2.0). Six sphingolipid–myelin metabolites showed coordinated biosynthetic depletion and catabolic elevation in both ASD groups without regression specificity. DHEA-S exhibited the largest subgroup differential (FC REG+/REG− = 8.89), with paradoxically greater depletion in the non-regressive group. This exploratory study identified several plasma metabolic features showing abundance differences among children with REG+, REG−, and typically developing controls. These findings are hypothesis-generating and require confirmation using authenticated standards, targeted quantitative methods, and independently recruited cohorts before any diagnostic, predictive, or therapeutic relevance can be established. Full article

Frozen mysid shrimp is the core feed for commercial seahorse aquaculture, yet quality deterioration caused by long-term cold storage severely constrains the survival and reproductive performance of seahorses. By integrating targeted metabolomics, physicochemical spoilage indicators, and 16S rRNA high-throughput sequencing, this study multidimensionally analyzed the stage-specific mechanisms of nutritional degradation and microecological deterioration of mysid feed at −20 °C under fresh (0 months), short-term frozen (2 months), and long-term frozen (10 months) conditions. The results demonstrate that short-term storage (2 months) effectively suppresses microbial-induced spoilage of mysids; however, freeze–thaw stress triggers cellular lysis, leading to a significant depletion of key water-soluble feeding-attractant amino acids, notably glycine and aspartate. In contrast, long-term frozen storage (10 months) induces severe lipid peroxidation and a massive accumulation of total volatile basic nitrogen (TVB-N). Microbiome analysis confirmed that the fundamental trigger for feed deterioration during the late storage stage is the explosive community succession of psychrotrophic specific spoilage organisms (SSOs), with Shewanella, Photobacterium, and Pseudoalteromonas emerging as the absolute dominant taxa. The highly active extracellular lipases and proteases secreted by these microbial communities extensively degrade the structural lipids of the feed, ultimately resulting in a paradoxical rebound in free fatty acid content during long-term storage. In summary, our research comprehensively details how freezing compromises diet quality through specific biological and chemical pathways. This establishes essential scientific groundwork aimed at refining commercial preservation techniques, executing precise dietary enrichments, and ultimately securing long-term viability across the captive Hippocampus breeding sector. Full article

Hepatocellular carcinoma (HCC) arises predominantly in chronic liver disease with a uniquely tolerogenic microenvironment. Immune checkpoint inhibitors (ICIs) have improved the prognosis of advanced HCC, yet most patients exhibit low response rates or therapeutic resistance due to the highly immunosuppressive tumor microenvironment. Metabolic reprogramming is not only a core hallmark of HCC but also a key regulatory axis connecting tumor cells and the immune system. HCC cells exhibit pronounced Warburg glycolysis, upregulated glutaminolysis, aberrant lipid storage and oxidation, enhanced ketone metabolism, and altered polyamine flux. These metabolic alterations lead to nutrient competition, lactate accumulation, amino acid depletion, and oncometabolite signaling, resulting in T cell exhaustion, macrophage polarization, T cell expansion, and impaired dendritic cell function, thereby influencing tumor progression, immune escape, and therapeutic resistance. Targeting metabolic–immune crosstalk represents a promising strategy for reversing immunosuppression and enhancing the efficacy of immunotherapy. In this review, we systematically summarize the core patterns of metabolic reprogramming in HCC, dissect the molecular mechanisms of metabolic crosstalk at the tumor–immune interface, and discuss the role of immunometabolic remodeling in therapeutic resistance. This review aims to provide a comprehensive theoretical basis and new research directions for improving the efficacy of HCC treatment by targeting the metabolic–immune regulatory axis. Full article

Background/Objectives: Metabolic dysfunction-associated steatotic liver disease (MASLD), a leading cause of chronic liver disease, encompasses a continuum from steatosis to metabolic dysfunction-associated steatohepatitis (MASH), fibrosis, cirrhosis, and hepatocellular carcinoma. This review aimed to synthesize current evidence on how metabolomic, lipidomic, and spatial multi-omic approaches illuminate MASLD pathogenesis and support precision hepatology. Methods: A structured narrative review was conducted through searches of PubMed, Scopus, and Web of Science, complemented by manual screening of key references. Studies were prioritized when they addressed MASLD biology, metabolic rewiring, lipid remodeling, mitochondrial dysfunction, inflammatory and fibrogenic pathways, gut–liver–adipose crosstalk, biomarker development, or therapeutic monitoring. Results: The reviewed evidence identifies MASLD as a systemic metabolic disorder shaped by excess lipid flux, enhanced de novo lipogenesis, impaired mitochondrial adaptation, oxidative and endoplasmic reticulum stress, sterile inflammation, and hepatic stellate-cell activation. Recurrent metabolomic signatures include altered amino acid, fatty acids, bile acid, and microbial co-metabolite pathways. Lipidomic studies consistently implicate depletion of protective polyunsaturated fatty acids, lysophosphatidylcholines, and phosphatidylcholines, in association with accumulation of diacylglycerols and ceramides, in the transition from steatosis to MASH and fibrosis. Emerging spatial and multi-omic analyses further resolve cell-specific metabolic niches involving hepatocytes, macrophages, endothelial cells, and stellate cells. Conclusions: Metabolomics provides a mechanistic and translational bridge between molecular injury, histological progression, and non-invasive risk stratification in MASLD. Future progress requires standardized analytical workflows, longitudinal validation, causal pathway interrogation, and integration with imaging, genetics, microbiome profiling, and treatment-response phenotyping. Clinical implementation will require standardized platforms, transparent metabolite identification, external validation across diverse populations, cost-effectiveness analyses, and regulatory-grade evidence of clinical utility. Full article

Background/Objectives: Major depressive disorder (MDD) has been increasingly associated with alterations of the gut microbiome through the microbiota–gut–brain axis. However, published findings remain highly heterogeneous, limiting identification of reproducible microbial signatures associated with depression. This systematic review aimed to evaluate reproducible taxonomic and functional gut microbiome alterations in patients with MDD compared with healthy controls. Methods: A systematic literature search was conducted in PubMed/MEDLINE, Scopus, Web of Science Core Collection, and the Cochrane Library for studies published between January 2016 and December 2025. Observational human studies evaluating gut microbiome composition in adults with clinically diagnosed MDD and healthy control groups were included. Methodological quality was assessed using the Newcastle-Ottawa Scale. Due to substantial methodological heterogeneity, findings were synthesized using structured qualitative narrative analysis. Results: Sixteen observational studies were included in the qualitative synthesis. Findings related to alpha diversity were inconsistent across studies, whereas beta diversity alterations demonstrated greater reproducibility across independent cohorts. The most recurrent microbiome pattern involved depletion of short-chain fatty acid (SCFA)-producing bacteria, particularly Faecalibacterium and Roseburia, together with recurrent alterations affecting members of the Ruminococcaceae, Lachnospiraceae, and Clostridia groups. Functional microbiome alterations demonstrated greater consistency than higher-level taxonomic findings and included reduced butyrate synthesis pathways, dysregulated amino acid and tryptophan metabolism, increased lipopolysaccharide biosynthesis, and enrichment of pro-inflammatory microbial signatures. Antidepressant-naïve cohorts generally demonstrated more homogeneous dysbiosis patterns than mixed-treated populations. Conclusions: Current evidence suggests that functional gut microbiome dysregulation may represent a more reproducible biological feature of MDD than isolated taxonomic alterations alone. However, substantial heterogeneity in study design, participant characteristics, sequencing methodologies, and analytical approaches continues to limit clinical translation. Large-scale longitudinal multi-omics studies using standardized methodologies are required to clarify the role of the gut microbiome in depressive disorders and to evaluate the potential utility of microbiome-based biomarkers and interventions in mental health and public health practice. Full article

Background/Objectives: The treatment of multidrug-resistant and hypervirulent Klebsiella pneumoniae is one of today’s biggest healthcare challenges. The depletion of therapeutic options necessities the application of new methods. One promising approach is to use phage-derived enzymes that target the capsule and make the causative more visible to the immune system. As proteins, these enzymes must be optimised by reducing their size and antigenicity to make them suitable for repeated use. Methods: In this study, the recently isolated and cloned K2B1orf61 K2 capsule-specific depolymerase was analysed structurally, and certain amino acid residues were deleted by cloning. The following amino acid residues were removed from the 80th (D2_N80), 115th (D3_N115), and 200th (D4_N200) N-terminal, and 250 (D5_C250) and 20 (D6_C20) from the C-terminal positions of the wild-type molecule (D1_wt). The resulting derivative molecules were compared with in vitro and in vivo tests. Results: In the presence of wild-type depolymerase, human serum was able to eliminate the target bacterium and save the lives of mice challenged with the bacterium in an originally lethal intraperitoneal model. However, the D5_C250 derivative lost all activity, meaning that the bacteria with the K2 capsule in the serum survived and all the mice died. Derivatives D2_N80, D3_N115, and D6_C20 exhibited prolonged activity in the serum killing assay, effectively eliminating bacteria within 5 h. Similar activity differences were revealed in the intraperitoneal experiment: D5_C250 had no rescue effect; however, D1_wt, D2_N80, D3_N115, D4_200, and D6_20 resulted in survival rates of 100%, 60%, 80%, 100%, and 20%, respectively. Conclusions: Our results demonstrate that molecular trimming is a promising procedure for developing ideal therapeutic depolymerases. Full article