Search Results (54,921)

Nitrification is a key process governing nitrogen (N) loss and greenhouse gas emissions in agricultural soils, and its regulation is strongly influenced by both chemical inhibitors and soil properties. Copper (Cu), a metal cofactor that is crucial for the function of ammonia monooxygenase (AMO), plays an important role in ammonia oxidation, whereas dicyandiamide (DCD) suppresses nitrification and may interact with Cu to inhibit AMO activity. However, the extent to which Cu availability and soil organic matter (SOM) jointly regulate DCD efficiency remains poorly understood. In this study, an incubation experiment was conducted using tropical paddy soils with contrasting SOM contents to explore how varying Cu levels (10 and 200 mg Cu kg⁻¹ soil) impact DCD efficiency in regulating the nitrification process and controlling nitrous oxide (N₂O) and carbon dioxide (CO₂) emissions. Our results showed that DCD generally suppressed nitrification, as indicated by reduced NO₃⁻ accumulation and lower NO₃⁻/NH₄⁺ ratios. However, the response to Cu was strongly SOM-dependent. Under low SOM, Cu addition was associated with a partial restoration of nitrification activity, suggesting a potential reduction in DCD efficiency, whereas under high SOM, this effect appeared to be attenuated, likely due to Cu complexation and reduced bioavailability. Increasing Cu levels further weakened DCD inhibition, particularly in low SOM soils. DCD significantly reduced N₂O emissions, but this mitigation effect declined with Cu addition, suggesting a Cu-mediated influence on nitrification–denitrification pathways. On the other hand, CO₂ emissions were reduced under DCD application and appeared to be further reduced under Cu treatments. Changes in enzyme activities and nitrifier gene abundances supported these patterns, suggesting distinct responses of AOA and AOB communities under varying SOM and Cu conditions. This study provided evidence that the interaction of Cu availability and SOM may play an important role in governing the efficacy of nitrification inhibitors. This highlights the importance of considering soil-specific chemical environments when optimizing N management strategies to reduce environmental N losses. Full article

Pomegranate peel is a food industry waste rich in polyphenols. To date, its effect in alleviating fatigue remains unclear. This study aimed to characterize the chemical composition of pomegranate peel polyphenols (PPPs), evaluate its antioxidant and anti-fatigue capacities, and investigate the underlying mechanism. In the current study, twenty main compounds, primarily flavonoids, phenolic acids, and anthocyanins, were identified from PPPs using LC-MS/MS. In H₂O₂-induced HepG2 cells, PPPs promoted cellular repair and reduced the production of intracellular malondialdehyde (MDA) and reactive oxygen species (ROS) via enhancing the activity of antioxidant enzymes (SOD, CAT, and GSH-Px). In the endurance swimming-induced fatigue mice model, PPPs prolonged mice exhaustion times, reduced accumulation of fatigue-related metabolites (BUN, LA, BA, LDH and CK), and alleviated liver and muscle tissue damage. Mechanistically, PPPs mitigated oxidative stress via activation of the Keap1/Nrf2 pathway, leading to increased expression of hemeoxygenase-1 (HO-1) and NAD(P)H quinone oxidoreductase 1 (NQO1). Furthermore, PPPs stimulated energy metabolism by activating the AMPK/PGC-1α/PPAR-α pathway, promoting mitochondrial biogenesis, enhancing glycogen storage, increasing ATPase activity (Na⁺-K⁺-ATPase, Ca²⁺-Mg²⁺-ATPase, and T-ATPase) and accelerating lipid β-oxidation. These findings suggest that PPPs is a promising anti-fatigue supplement and could be further utilized in the nutritional industry. Full article

Bax, a key member of the B-cell lymphoma 2 (Bcl-2) protein family, is essential for inducing mitochondrial apoptosis. In this study, we employed yeast two-hybrid screening to identify ubiquitin-specific protease 49 (USP49) as a binding partner of Bax. Subsequent immunoprecipitation and glutathione S-transferase (GST) pull-down assays confirmed their direct interaction. Functional assays showed that USP49 reduces Bax polyubiquitination at multiple lysine residues within ubiquitin, with the strongest effects observed on K11, K29, K33, and K63 linkages. In contrast, its effect on K48-linked ubiquitination was weak and insufficient to influence Bax protein stability, indicating that USP49 does not regulate Bax abundance through proteasomal degradation. Instead, RT-qPCR analysis revealed that USP49 overexpression significantly increased Bax mRNA levels, and this effect was maintained under apoptosis stimuli (UV, H₂O₂, and STS), indicating transcriptional regulation largely independent of stress-induced damage, whereas its effect was modest and not statistically significant under starurosporine treatment. Collectively, these findings demonstrate that USP49 regulates Bax primarily through K29/K33/K63-linked ubiquitination and transcriptional upregulation, highlighting its role as a stress-responsive modulator of apoptosis and a potential therapeutic target in cancer. Moreover, under DNA damage condition (UV), USP49 overexpression marked enhanced apoptosis. Full article

Amino acids are essential nutrients for both tumor growth and immune cell function. Cancer cells actively deplete intracellular and extracellular amino acid pools, and limited amino acid availability in the tumor microenvironment (TME) reinforces immunosuppression. Mitochondria are not merely adenosine triphosphate-producing organelles. Amino acid metabolism within mitochondria contributes to tumor progression and influences immune cell fate and effector function. These effects are mediated through biosynthetic precursor generation for lipid, nucleotide, and polyamine synthesis, maintenance redox homeostasis through glutathione and NAD⁺ metabolism, and regulation of gene expression through aryl hydrocarbon receptor signaling. In this review, we discuss four major mitochondrial amino acid metabolic pathways: glutamine-driven anaplerosis, serine/glycine-dependent one-carbon metabolism, arginine–ornithine metabolism, and tryptophan–kynurenine metabolism. We examine how these pathways are rewired in cancer cells, how they influence immune cell function through direct or mitochondria-associated mechanisms, and how such metabolic reprogramming promotes tumor progression while impairing antitumor immunity. Finally, we consider therapeutic strategies to improve cancer immunotherapy by targeting amino acid metabolism, including mitochondrial metabolic enzymes. This review may help guide the development of more effective metabolic biomarkers and mitochondria-based therapeutic strategies for cancer immunotherapy. Full article

Mitochondrial transplantation has been proposed as a strategy to restore cellular bioenergetics after oxidative injury, but the mechanisms governing ATP recovery remain unclear. Using placental mitochondria, we examined ATP restoration following H₂O₂-induced oxidative stress. Unmodified mitochondria modestly increased ATP under baseline conditions but failed to restore ATP after injury. In contrast, lipid-coated mitochondria (MitoCoat) and lipid-encapsulated mitochondria-associated mRNAs (MitoCoat–mRNA) significantly increased ATP levels in injured cells. Transcriptomic analyses revealed that ATP recovery occurred without the normalization of canonical glycolytic or oxidative phosphorylation (OXPHOS) gene programs. Instead, unmodified mitochondria induced broad transcriptional responses associated with immune activation and cellular stress, whereas MitoCoat elicited a more restricted transcriptional profile. Notably, mitochondria-associated mRNAs alone restored ATP without detectable changes in host transcriptional programs. The removal of mitochondrial surface-associated ribosomes or the inhibition of cytosolic but not mitochondrial translation attenuated ATP recovery. The restoration of key metabolic enzymes through cytosolic translation, including PFKP, pyruvate dehydrogenase, and ATP synthase subunit ATP5A suggests that mitochondria-associated mRNAs promote recovery by re-establishing coupling between glycolysis and mitochondrial OXPHOS. Together, these findings identify encapsulated mitochondria-associated mRNAs as a potential strategy to restore cellular bioenergetics under oxidative stress. Full article

Split nitrogen (N) application is an important agronomic measure for improving wheat yield and quality, yet how rhizosphere nitrogen-transforming microbes respond to split N strategies and the underlying mechanisms remain unclear. This study investigated the effects of six N treatments, including control, basal application, jointing-stage soil topdressing, and foliar applications at booting, anthesis, and 10 days post-anthesis, on the community structure and diversity of key rhizospheric nitrogen cyclers (ammonia-oxidizing archaea (AOA), ammonia-oxidizing bacteria (AOB), and nitrite-oxidizing bacteria (NOB)) in wheat. Results showed that AOB and NOB alpha diversity were significantly modified by split N application. N application at anthesis enhanced AOB richness and diversity more than the later application, while concurrently decreasing NOB diversity. Booting-stage application enriched Nitrosospira and Nitrosomonas in the AOB community, whereas anthesis application increased Nitrososphaera sp. JG1 in AOA, but decreased Candidatus Nitrospira inopinata in NOB. Redundancy analysis identified soil pH, moisture, organic carbon, and key enzyme activities as the main drivers of microbial community assembly. Although no significant differences were observed in key agronomic traits among treatments, the 10 days post-anthesis treatment showed numerically superior yield and N uptake. Notably, AOB community evenness was significantly positively correlated with grain yield, protein yield, and N uptake, whereas NOB community diversity showed negative correlations. These findings demonstrate that split N application, particularly late foliar spray at 10 days post-anthesis, can modulate soil physico-chemical properties to selectively shape nitrogen-transforming microbial communities (notably AOB) in the wheat rhizosphere. This study provides a theoretical foundation for designing precise N management strategies rooted in rhizosphere ecology, with the goal of simultaneously improving yield, grain quality, and nitrogen use efficiency. Full article

Neurodegenerative diseases (NDDs) in children represent a heterogeneous group of rare but collectively significant disorders characterized by progressive neurological decline, developmental regression, and substantial morbidity and mortality. Unlike adult-onset neurodegeneration, pediatric conditions are predominantly genetic and frequently arise from defects in fundamental cellular pathways, including lysosomal degradation, mitochondrial oxidative phosphorylation, peroxisomal lipid metabolism, and myelin maintenance. This comprehensive review synthesizes current knowledge regarding the epidemiology, molecular classification, pathophysiology, and emerging therapeutic strategies of major pediatric neurodegenerative disorders. Epidemiological data indicate a “rare-but-many” landscape, where individually uncommon diseases collectively impose a measurable population burden. Mechanistically, disease progression reflects converging processes such as toxic substrate accumulation, impaired autophagy–lysosome flux, mitochondrial bioenergetic failure, oxidative stress, neuroinflammation, and glial dysfunction. Representative groups discussed include lysosomal storage disorders, leukodystrophies, mitochondrial encephalopathies, peroxisomal disorders, and other monogenic neurodegenerative syndromes. Advances in next-generation sequencing, metabolic profiling, and neuroimaging have substantially improved diagnostic accuracy and enabled earlier detection, including through newborn screening programs. Therapeutic paradigms are shifting from primarily supportive care toward mechanism-based interventions, including enzyme replacement therapy, hematopoietic stem cell transplantation, substrate reduction strategies, and gene therapy approaches. Early molecular diagnosis is increasingly recognized as critical for optimizing outcomes, particularly in disorders amenable to presymptomatic intervention. Continued integration of genomic medicine, standardized epidemiologic surveillance, and translational research will be essential to refine disease classification, improve prognostication, and expand access to targeted therapies. Collectively, pediatric neurodegenerative diseases exemplify the intersection of developmental neurobiology and inherited metabolic dysfunction, underscoring the need for multidisciplinary, precision-based clinical strategies. Full article

In this study, the native activity of an arabinogalactan endo-β-1,4-galactanase from Aspergillus niger (AnGal) was evaluated under different reaction conditions, and in the presence of various acceptor molecules during the cleavage of the β-1,4-glycosidic linkage of a chromogenic compound and lupin galactan. A combination of spectrophotometric assays, mass spectrometry and chromatography techniques provided insights into the reaction mechanism of the enzyme and its use in the synthesis of galactosides and galactooligosaccharide derivatives. In reactions containing 2-nitrophenol galactopyranoside, AnGal promoted transglycosylation, generating longer galactooligosaccharide derivatives of 2-nitrophenol that have not previously been reported for GH53 enzymes. Furthermore, new alcoholysis products have been detected when AnGal acted on lupin galactan in the presence of benzyl alcohol. To the best of our knowledge, we are first to report the synthesis of galactotriose and galactotetraose derivatives formed by endo-β-1,4-galactanase alcoholysis. This work showcases the potential of utilizing galactanases in the synthesis of valuable galactosides and galactooligosaccharides, under mild conditions from sustainable biomass sources. Potential beneficial applications may be found in several industrial fields such as in the preparation of prodrugs and prebiotics. Full article

The ability to precisely edit genetic characteristics with a CRISPR (clustered regularly interspaced short palindromic repeats)/Cas (CRISPR-associated) immunity complex is a revolutionary advance in science. Originally discovered in bacteria as part of a natural defense mechanism against viruses, CRISPR/Cas provides a precise, efficient, and relatively simple method for editing genes in microbes, plants, animals, and humans. The process relies on the Cas protein, an enzyme that cleaves and unwinds DNA at targeted locations. This process is guided by RNA sequences complementary to the DNA or RNA sequence of interest, allowing for changes to the genome through innate non-homologous end joining (NHEJ) and homology-directed repair (HDR). The potential applications of CRISPR/Cas are immense and, in agriculture, is facilitating crop development with resistance to abiotic, biotic, and agronomic characteristics that improve yield, quality, and food security. Gene editing also facilitates the relatively rapid modification of regulatory and complex pathways that enable studies to advance our understanding of gene function. This review provides an update of the fast-evolving CRISPR/Cas modification of important crops to address emerging global population, as well as environmental and climate challenges. Full article

Aureobasidium pullulans is a polyextremotolerant yeast-like fungus increasingly recognized for its role in food ecosystems and its emerging potential in flavour development and nutrient modulation. However, systematic evaluations of autochthonous grape-associated populations integrating technological performance and safety-related traits remain limited. This study provides a broad phenotypic screening of 70 isolates from Maraština grapes (Dalmatia, Croatia), applying an integrated functional screening approach to link enzymatic potential, environmental resilience, and food safety. Most isolates displayed multiple hydrolytic enzymes, with widespread cellulase, pectinase, xylanase, esterase, and protease activities. Several isolates showed very high enzymatic indices, supporting their potential for plant-derived substrate transformation, aroma release, and food processing applications. β-glucosidase and urease activities were common, while amylase was limited. Ecological screening confirmed robust adaptability to salinity, osmotic stress, and wide pH ranges. Notably, 31% of isolates demonstrated phosphate solubilization capacity, indicating a possible contribution to mineral bioavailability and nutritional enhancement. Safety screening revealed decarboxylation of selected amino acids, while two isolates lacked detectable activity, highlighting them as candidates for further safety evaluation. Overall, this work establishes a framework for selecting A. pullulans isolates for next-generation, flavour-oriented and nutritionally enhanced food applications, supporting sustainable bioprocessing and future industrial validation. Full article

The Svx protein is an established virulence factor in the phytopathogenic pectolytic bacterium Pectobacterium atrosepticum and is secreted into the host plant apoplast. However, its particular role has long remained enigmatic. In our recent studies, we showed that Svx proteins from pectolytic bacteria are metallopeptidases composed of two domains: peptidase and acyltransferase-like domains. Structural organization of the peptidase domain active site led us to hypothesize that its preferred substrates are extensins—hydroxyproline-rich glycoproteins of the plant cell wall. Nevertheless, direct experimental confirmation of extensin hydrolysis by Svx was lacking, and the precise role of the acyltransferase-like domain remained unclear. The present study aimed to address these issues. We showed that Svx indeed cleaves extensins while not degrading some other glycosylated and non-glycosylated proteins. The acyltransferase-like domain was shown to be critical for recognition of arabinan substituents in extensins, thereby providing optimal enzyme–substrate complementarity. Deletion of the acyltransferase-like domain abolished extensin hydrolysis by the truncated variant of Svx. Our study provides the first example of an apoplast-secreted protease from a phytopathogenic bacterium whose specificity toward specific target proteins (extensins) is achieved, at least in part, through structural elements that specifically recognize the distinctive glycosylation pattern of the target proteins. Full article

Anthracnose, caused by Colletotrichum sp. isolate XCC1, is a major postharvest disease causing significant quality deterioration and economic losses in ‘Cat Chu’ mango during storage. This study evaluated the effectiveness of sodium alginate–carboxymethyl cellulose (SA-CMC) coating with natamycin for controlling anthracnose and maintaining postharvest fruit quality. Mango fruits were treated with the SA-CMC-Natamycin coating and stored under controlled conditions (25 ± 2 °C; RH = 60 ± 5%) to assess disease development, plant defense enzyme activities, and fruit quality attributes. Natamycin inhibited spore germination of Colletotrichum sp. isolate XCC1 with a Minimal Inhibitory Concentration (MIC) of 6.25 µg mL⁻¹. The SA-CMC-Natamycin coating significantly reduced anthracnose development, resulting in a three-fold decrease in disease incidence and a 3.86-fold reduction in disease severity compared with the control on day 9 of storage. However, the persistence of the treatment was limited since no significant disease incidence reduction was observed after 15 days. The treatment also enhanced chitinase (CHI) and β-1,3-glucanase (GLU) activities and increased phenolic compound accumulation. In addition, the coating delayed fruit ripening by maintaining firmness, titratable acidity (TA), vitamin C, and chlorophyll while suppressing increases in color change and total soluble solids (TSS). These results demonstrate that SA-CMC-Natamycin coating is a promising eco-friendly strategy for controlling anthracnose and preserving postharvest quality of ‘Cat Chu’ mango. Full article

Low-light (LL) stress is a major abiotic limiting factor in protected cherry tomato production, adversely affecting vegetative growth, inducing oxidative damage, and disrupting fruit sugar metabolism. To clarify the regulatory role of exogenous abscisic acid (ABA) in mitigating LL stress, we examined the effects of varying ABA concentrations on plant growth, antioxidant capacity, and fruit sugar metabolism in cherry tomatoes under low-light conditions. A two-factor randomized complete block design, with two light regimes—normal light (NL, 100% natural sunlight) and low light (LL, 25% natural sunlight)—and three ABA concentrations (CK: 0 mg·L⁻¹, T1: 10 mg·L⁻¹, T2: 20 mg·L⁻¹). Fruits were sampled at three typical ripening stages (green mature, breaker, and red ripe) to evaluate vegetative and reproductive physiological responses. The results showed that exogenous ABA application effectively suppressed LL-induced excessive stem elongation and alleviated LL-caused reductions in stem diameter and biomass accumulation. ABA treatment significantly increased peroxidase (POD) activity and reduced malondialdehyde (MDA) and hydrogen peroxide (H₂O₂) accumulation, thereby relieving LL-triggered oxidative damage. In addition, ABA regulated key sugar-metabolizing enzymes (soluble acid invertase (SAI), sucrose synthase (SS), sucrose phosphate synthase (SPS), and amylase (Amy)) and the transcript levels of related functional genes (HXK1, SPS, SS, AI), thereby mediating stage-dependent fruit sugar metabolism under LL stress. In conclusion, exogenous ABA effectively modulates vegetative growth, antioxidant homeostasis, and stage-specific fruit sugar metabolism, ultimately alleviating low-light stress damage in cherry tomato. Among the tested treatments, 20 mg·L⁻¹ ABA exhibited the most pronounced mitigation effects, which can be recommended as an optimal foliar application concentration for cherry tomato cultivation in low-light protected facilities. Full article

Iron overload significantly contributes to chronic kidney disease progression by triggering oxidative stress and mitochondrial impairment via the Fenton reaction. This study investigates the protective role of aldehyde dehydrogenase 1a3 (ALDH1a3), an enzyme that detoxifies reactive aldehydes, in renal iron overload. C57BL/6N mice were fed a 2.25% ferric citrate diet for 24 weeks to establish a chronic model, followed by treatment with the chelator Dimercaprol (DP). In vitro, TCMK−1 cells were subjected to iron intervention with ALDH1a3 overexpression or inhibition. Chronic iron overload induced significant renal iron deposition, lipid peroxidation (elevated MDA, depleted GSH), and mitochondrial structural damage. ALDH1a3 was endogenously upregulated in renal tubular epithelial cells under iron stress. Overexpressing ALDH1a3 significantly enhanced cell viability, suppressed reactive oxygen species and MDA levels, and preserved mitochondrial membrane potential, whereas its inhibition exacerbated cellular damage. Furthermore, DP treatment reduced iron deposition and was associated with increased ALDH1a3 expression. In conclusion, ALDH1a3 acts as a critical endogenous protective factor against iron−induced nephrotoxicity by mitigating oxidative damage and maintaining mitochondrial stability. These findings indicate that ALDH1a3 is a promising potential therapeutic target for the treatment of iron overload−related kidney diseases. Full article

Background: Percutaneous liver biopsy is a cornerstone in the diagnostic and therapeutic management of pediatric liver diseases. However, data on the optimal needle gauge for coaxial techniques in children remain scarce. Smaller-gauge needles may theoretically enhance safety but could potentially compromise diagnostic yield. Objectives: The primary objective of this study was to evaluate and compare the safety and diagnostic clinical adequacy of ultrasound-guided percutaneous liver biopsies performed with semi-automated 20G versus 18G coaxial needles in pediatric patients. Patients and Methods: This retrospective cohort study included consecutive patients aged ≤19 years who underwent percutaneous non-targeted liver biopsies at a tertiary medical center between 2006 and 2012. Patient demographics, biopsy technique parameters (including needle gauge, number of cores, and tract embolization), and procedure-related complications were analyzed. Procedural success was defined by diagnostic and clinical adequacy, requiring a definitive pathology report and the presence of ≥7 portal tracts (the widely accepted threshold for a reliable histologic diagnosis). Complications were classified according to the Society of Interventional Radiology guidelines. Results: A total of 320 biopsies were performed in 260 patients (44.6% female; mean age 7.4 ± 6.0 years). Common indications included post-liver transplantation surveillance (28.4%) and unexplained liver enzyme elevation (22.5%). Biopsies were performed using 18G (n = 148; 46.3%) or 20G (n = 172; 53.7%) coaxial needles. Diagnostic and clinical adequacy was achieved in 100% of the procedures, with biopsy results directly influencing clinical management in 39.7% of cases. The overall complication rate was 5.3% (3.4% minor, 1.9% major), with no procedure-related mortality. While raw complication rates were numerically higher in the 20G group (likely to reflect an operator-driven selection bias for younger or higher-risk patients), the differences between the 18G and 20G needles were not statistically significant. Notably, the use of the 20G needle was associated with a significantly reduced clinical need for post-biopsy tract embolization. Conclusions: Our findings demonstrate no statistically significant differences in complication rates or diagnostic clinical adequacy between 18G and 20G coaxial needles for pediatric percutaneous liver biopsies. When selected based on appropriate clinical judgment, the 20G needle provides a high diagnostic yield and serves as an effective option, particularly for reducing the need for tract embolization. However, both 18G and 20G needles represent acceptable clinical options within the pediatric interventional armamentarium. Ultimately, the choice of needle gauge should be meticulously tailored to individual patient characteristics, bleeding risk profiles, and specific clinical indications, rather than uniformly recommending a smaller gauge across all pediatric age groups. Full article