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Muscle Massage Adding Capacitive Resistive Electric Transfer Therapy in Active or Sham Condition for Post-Exercise Recovery in Athletes: A Crossover Clinical Trial.

The increasing demands of elite sports reduce recovery time, impair performance, and increase injury risk. Efficient lactate transport is essential for postexercise recovery. Capacitive resistive electric transfer (CRET) therapy enhances deep tissue heating, induces vasodilation, and promotes circulation. To evaluate whether adding active CRET to a standardized muscle recovery massage, compared with the same massage plus sham CRET, influences indicators of muscle recovery following a maximal anaerobic effort test. A randomized, single-blind, sham-controlled, and crossover clinical trial was conducted in 25 athletes. Participants completed four visits and, after the maximal power and anaerobic capacity test (Wingate test), received a standardized muscle recovery massage combined with either active CRET or sham CRET. Blood lactate levels, muscle oxygenation, muscle thickness, echogenicity, knee extension force, and muscle activity were assessed before and after the test, after treatment, and 24&#xa0;hours later. Compared with massage plus sham CRET, massage plus active CRET was associated with lower blood lactate concentration at 60&#xa0;min postexercise (p&#xa0;=&#xa0;0.029). Ultrasound-derived muscle thickness and echogenicity also differed between conditions at several time points (p&#xa0;<&#xa0;0.05). However, no significant differences were observed in Wingate test performance, force, muscle activity, and oxygenation between conditions. In athletes performing repeated Wingate exercise, adding active CRET to massage was associated with lower blood lactate concentration at 60&#xa0;min postexercise and with differences in ultrasound-derived muscle thickness and echogenicity compared with sham CRET plus massage. However, these between-condition differences were not accompanied by clear short-term functional recovery benefits. TRIAL REGISTRATION: NCT06906146.

Humans

Proteomic characterization of the acquired enamel pellicle under acidic challenges at early and mature formation stages.

OBJECTIVES: This study aimed to characterize acquired enamel pellicle (AEP) proteomic changes after exposure to citric acid (CA) and hydrochloric acid (HCl) under different pellicle formation times (3 and 120&#x202f;min) in the same volunteers. DESIGN: Nine healthy volunteers participated in this randomized crossover in vivo study. The AEP was allowed to form for 3 or 120&#x202f;min and subsequently exposed for 10&#x202f;s to deionized water (control), 1% CA (pH 2.5), or 0.01&#x202f;M HCl (pH 2.0). Pellicle samples were collected, followed by protein extraction, tryptic digestion, and analysis by nanoliquid chromatography (nanoLC) coupled to mass spectrometry (MS) with MSE (data-independent acquisition; nanoLC-MS&#x1d31;). Label-free quantitative proteomics were performed for relative quantification using t-test (p&#x202f;<&#x202f;0.05). RESULTS: At 120&#x202f;min, CA exposure markedly reduced several typical AEP proteins, especially acidic proline-rich proteins (PRPs). Conversely, basic PRPs were upregulated, suggesting acid-resistance protein signature. At 3&#x202f;min, basal-layer proteins (PRPs, cystatins, histatins and mucins) were more abundant. Hemoglobins increased 6-8-fold (up to 150-fold in 3&#x202f;min control), suggesting association with early pellicle formation and an acid-resistant protein signature. CA exposures for 120&#x202f;min also upregulated typical AEP proteins (PRPs, mucins, cystatins, immunoglobulins), while HCl exposure depleted albumins and lactotransferrin. CONCLUSION: Intrinsic and extrinsic acids induce distinct proteomic signatures in the AEP. Hemoglobin and PRPs appear consistently enriched in the early pellicle layer, reflecting an initial acid-resistant protein signature. These findings provide new insights into the molecular remodeling of the AEP following intrinsic and extrinsic acid exposure, highlighting proteins potentially involved in early-stage pellicle formation.

Humans

Comprehensive identification of carboxylic acids by using bromine isotope-based chemical isotope labelling and structure-guided molecular network.

Carboxylic acids (CAs) are important contributors to the flavor quality of sauce-flavor Chinese Baijiu, yet their comprehensive analysis remains challenging due to poor ionization efficiency, weak chromatographic retention, and limited annotation capability. Herein, we developed a workflow for the high-coverage discovery and annotation of CAs in Baijiu by coupling chemical isotope labeling-liquid chromatography-mass spectrometry with a structure-guided molecular network strategy (SGMNS). A bromine-containing derivatization reagent, 1-(3-aminopropyl)-3-bromoquinolin-1-ium bromide (APBQ), was designed and synthesized to exploit the natural isotope distribution of bromine and characteristic MS/MS fragmentation behavior. Following APBQ derivatization, the target CAs showed superior chromatographic retention and favorable analytical performance. Based on isotopic peak pairing in MS1 and diagnostic fragment validation in MS2, 372 potential CA derivatives were discovered from pooled Baijiu samples and 355 of them were validated by diagnostic fragments in MS2 spectra. To address the scarcity of derivatized spectral libraries, SGMNS was employed for annotation using a background network constructed from APBQ-labeled candidates derived from the Expanded Chinese Baijiu Compound Database. The developed method was further applied to profile Baijiu samples, revealing pronounced differences in CA composition across the seven fermentation rounds. Notably, rounds 3 to 5 exhibited the largest numbers of differential CAs. This study provided an effective analytical strategy for large-scale CA profiling, offering new insight into the chemical basis of flavor formation during multi-round fermentation of sauce-flavor Baijiu.

Isotope Labeling

Early proteomic and metabolic signatures of liver and eye in OAT-deficient mice.

Ornithine aminotransferase (OAT) deficiency causes hyperornithinemia and gyrate atrophy (GA) of the choroid and retina, a rare inherited retinal degeneration. To understand the early molecular changes that make the eye susceptible to damage, we performed quantitative proteomic and metabolomic profiling of liver, retina, and retinal pigment epithelium and choroid (RPE/Cho) from OAT-deficient (Oatrhg) mice prior to detectable vision impairment. In addition to reduced OAT expression and elevated ornithine, methylation-related metabolites such as N(6)-methyl-lysine were altered in all examined tissues of Oatrhg mice. In the liver, excess ornithine was directed into urea cycle metabolism, together with altered expression of detoxification enzymes and histone H2B proteins. In contrast, the retina showed minimal proteomic changes but pronounced alterations in amino acid pathways that support glutamate homeostasis. The RPE/Cho demonstrated the most extensive proteomic changes, particularly in mitochondrial metabolism, cytoskeleton, and extracellular matrix, along with changes in metabolites involved in lysine metabolism, energy metabolism, and antioxidant capacity. Incubation with 13C lysine demonstrated that lysine was primarily degraded in RPE/Cho but not the retina, and ornithine enhanced lysine degradation in an OAT-dependent manner. Together, these findings highlight common and tissue-specific impacts of OAT on the liver and ocular tissues and provide insight into early molecular changes that contribute to the selective vulnerability of the eye in GA. Proteomics data are available via ProteomeXchange (PXD063614) and metabolomics data via MassIVE repository (MSV000101103).

Animals

Molecular characterization of 16 MAPK genes in silver carp (Hypophthalmichthys molitrix) and the differences of their mRNA expression between Qiandao Lake and Taihu Lake.

Mitogen-activated protein kinase (MAPK), a serine-threonine protein kinase, is involved in a variety of stress-induced responses and also plays an important regulatory role in cell metabolism. In the study the open reading frames (ORFs) of 16 MAPK genes in silver carp (Hypophthalmichthys molitrix) were obtained and verified, with the evaluations of their taxonomy, structures, conserved motifs, and evolutionary linkages. And the expression patterns of these genes in the silver carp from Qiandao Lake and Taihu Lake were explored for better understanding the response of MAPK genes to different water environment. MAPK genes of silver carp were divided into three subfamilies, including extracellular signal-regulated kinase (ERK) subfamily, p38 subfamily and C-Jun N-terminal kinase (JNK) subfamily. All these genes possessed similar structures and conserved motifs of MAPK family. Realtime qPCR revealed that the expression patterns of 10 MAPK genes (ScMAPK1, ScMAPK3, ScMAPK4, ScMAPK7, ScMAPK15, ScMAPK8a, ScMAPK8b, ScMAPK9, ScMAPK10 and ScMAPK11) in head kidney, spleen and gill of silver carp in Taihu Lake and Qiandao Lake were different. These findings provide a basis for further research on the function of MAPK in silver carp.

Animals

Nitrogen sources and concentrations shape algal odor compounds: Key drivers of &#x3b2;-cyclocitral and &#x3b2;-ionone in water bodies of the lower Yangtze River.

Taste and odor (T&O) compounds derived from cyanobacterial blooms pose escalating threats to freshwater security worldwide, yet the drivers of specific T&O metabolites remain poorly constrained. Here, we investigated the dual effects of nitrogen (N) sources and concentrations on the production of &#x3b2;-cyclocitral and &#x3b2;-ionone, two algal-derived T&O compounds, through integrated field surveys (54 sites across lakes and rivers) in the eutrophic lower Yangtze River, China, and laboratory cultivation of typical cyanobacteria (Microcystis aeruginosa and Pseudanabaena cinerea). Our field data revealed that the concentrations of &#x3b2;-cyclocitral and &#x3b2;-ionone in lakes and rivers were not significantly different, but increased with the trophic level index. Redundancy analysis and Mantel analysis showed that Microcystis and Pseudanabaena were potentially dominant contributors to &#x3b2;-cyclocitral and &#x3b2;-ionone in the water column. Structural equation modeling and variation partitioning analysis showed that enhanced nitrate (NO3--N) significantly promoted the production of these compounds. Laboratory experiments demonstrated that inorganic N (NaNO&#x2083;) maximized total T&O yields by promoting algal biomass, whereas organic N (urea and glutamic acid) elevated the T&O production per unit biomass by 1.5- to 9.5-fold. Notably, Pseudanabaena exhibited a 2.3-fold higher &#x3b2;-ionone yield than Microcystis, with greater sensitivity to N concentrations. Our study highlights the critical role of nitrogen pollution, both source and concentration, in the production of T&O compounds by phytoplankton and provides reference data for managing T&O issues in rivers and shallow lakes.

Norisoprenoids

Tranexamic acid protects human dermal fibroblasts from D-galactose-induced senescence via the GPR30/MAPK pathway.

BACKGROUND: Tranexamic acid (TXA) is widely used for pigmentary disorders, but its anti-ageing potential remains unclear. This study aimed to evaluate whether topical 3% TXA improves early periorbital wrinkles in women with facial melasma and to investigate whether TXA protects human dermal fibroblasts from D-galactose-induced senescence via the GPR30/MAPK pathway. METHODS: Fifty women with melasma were randomized to 3% TXA serum plus moisturizer or moisturizer alone for 8&#x2009;weeks, with follow-up to week 12. Periorbital wrinkles were graded using a modified Fitzpatrick Wrinkle Scale (MFWS). Separately, D-gal-induced senescence in HDFs was assessed via viability, SA-&#x3b2;-gal activity, senescence markers, ROS, antioxidant enzymes, SASP/ECM gene expression, and MAPK activation. GPR30 involvement was examined using antagonist G15, shRNA knockdown, and molecular docking. RESULTS: Topical TXA produced significantly greater MFWS reductions versus moisturizer alone at weeks 4, 8, and 12, with benefit persisting post-treatment. In HDFs, TXA preserved viability, reduced SA-&#x3b2;-gal positivity, attenuated p21/p16, restored Lamin B1, decreased ROS, and rescued antioxidant activities. TXA downregulated IL-6, IL-8, MMP1, and MMP3, and suppressed D-gal-induced ERK, JNK, and p38 phosphorylation. These effects were weakened by G15 or GPR30 knockdown; docking supported a stable TXA-GPR30 interaction. CONCLUSIONS: TXA showed clinical anti-wrinkle activity in melasma patients and protected HDFs from D-gal-induced senescence, partly via GPR30-dependent modulation of oxidative stress, SASP/ECM expression, and MAPK signalling. TXA is a promising candidate for skin ageing intervention.

Humans

Quantifying the aromatic amino acid metabolome: UPLC-MS/MS analysis of aromatic amino acids and their host and co-metabolites in plasma.

Aromatic amino acids (AAAs), tryptophan, phenylalanine, and tyrosine along with their pathway metabolites have been implicated in the pathogenesis of diseases ranging from cardiovascular, neurological, inflammatory, and cancer diseases, among others. As such, the measurement of the primary AAAs, their host pathway metabolites, and microbiome derived co-metabolites in blood can provide a sensitive reflection of systemic health. The aim of the study was to develop a method for the quantification of 17 metabolites, the three AAAs and various of their metabolites in plasma using a high-throughput ultra performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method. The method demonstrated a dynamic range (1 to 16,700&#xa0;ng/mL), with detection limits (LOD) as low as 0.05&#xa0;ng/mL. Quantification limits ranged from 3 to 5019&#xa0;ng/mL (LLOQ) and up to 16,700&#xa0;ng/mL (ULOQ). Recovery at LQC, MQC, and HQC was satisfactory and consistent across most metabolites, with significant matrix effects observed only for 4-ethylphenol sulfate. Furthermore, intra and inter-day accuracy and precision met all acceptance criteria at all quality control concentrations for most of the metabolites. Measurement of NIST SRM 1950 showcased the method's accuracy for most of the metabolites. Finally, the method was applied on the analysis of plasma samples from 55 individuals (13 males and 42 females) providing information on AAAs and their pathway metabolites relevant concentrations in human plasma.

Amino Acids, Aromatic

Evaluating the persistence of semen under controlled environmental conditions.

When semen is deposited at a crime scene, it may be exposed to harmful environmental conditions. It is important to understand to what extent the different components of semen, specifically acid phosphatase (AP), prostate specific antigens (PSA), sperm and DNA, may become less detectable after exposure to high temperatures and varying levels of humidity. In this study, semen (50&#xa0;&#x3bc;L) was deposited onto squares of black cotton and exposed to 45&#xa0;&#xb0;C and a relative humidity (RH) of 10 or 80% for 0, 7, 14, 21 or 28&#xa0;days (n&#xa0;=&#xa0;5 per day, per climate condition). Source testing included AP test reagent, ABAcard&#xae; p30 immunoassay kits, and hematoxylin and eosin staining. DNA was extracted using the DNA IQ&#x2122; System (Promega, Australia) and quantified using Quantfiler Trio&#x2122; (Thermo Fisher Scientific, Australia). Over the 28-day period under both RH conditions, the time taken for a positive AP test to develop increased significantly (p&#xa0;<&#xa0;0.01) and the number of sperm observed decreased significantly (p&#xa0;<&#xa0;0.01). All ABAcard&#xae; p30 tests were positive regardless of exposure time or conditions. No impact on the quantity of DNA recovered was observed when semen was exposed to 45&#xa0;&#xb0;C and 10% RH, with a higher median quantity of DNA recovered at day 28 compared to day 0. In contrast, when the RH was raised to 80%, the median quantity of DNA recovered was substantially less at day 28 (81.5&#xa0;ng, IQR: 87.5&#xa0;ng) compared to day 0 (181.5&#xa0;ng, IQR: 1172.4&#xa0;ng). This study highlights the impact that temperature and RH may have on the persistence of AP, PSA, sperm and DNA over time.

Humans

Proteomic insights into hepatic responses to high soybean meal inclusion with citric acid supplementation in hybrid grouper (Epinephelus fuscoguttatus&#xa0;&#xd7;&#xa0;Epinephelus lanceolatus) juveniles.

This study evaluated the growth performance and hepatic proteomic responses of juvenile hybrid grouper (Epinephelus fuscoguttatus&#xa0;&#xd7;&#xa0;Epinephelus lanceolatus) juveniles fed diets containing 30% or 40% soybean meal (SBM), with or without 3% citric acid supplementation, and compared with a fishmeal (FM) control diet over a 10-week feeding trial. Fish fed 30% SBM (LSBM) showed a final body weight comparable to the FM group, whereas fish fed 40% SBM (HSBM) recorded significantly reduced growth and net protein utilization (NPU) (p&#xa0;<&#xa0;0.05). Supplementation of citric acid in the 40% SBM diet (HSBM + CA) significantly improved NPU and partially restored growth relative to HSBM. LC-MS/MS based quantitative proteomics identified 1544 hepatic proteins and showed clear dietary segregation. Differentially expressed proteins were predominantly associated with reduced abundance of proteins involved in lipid metabolism, amino acid metabolism, pyruvate metabolism, and the tricarboxylic cycle across all SBM diets, suggesting a shift in oxidative metabolic capacity. In contrast, LSBM induced upregulation of spliceosome-associated proteins and RNA processing components, suggesting adaptive post-transcriptional regulation under moderate SBM inclusion. In contrast, HSBM exhibited greater reduction in metabolic protein abundance without comparable upregulation of adaptive regulatory components, coinciding with reduced nutrient retention. Protein-protein interaction analysis further confirms the correlation between the regulation of spliceosomal clusters and mitochondrial lipid-catabolic modules. Citric acid supplementation did not markedly reverse hepatic metabolic protein changes but improved protein retention. Data are available via ProteomeXchange with identifier PXD081994. These findings suggest a tolerance limit between 30% and 40% SBM inclusion, with 30% inducing adaptive hepatic proteomic responses compatible with maintained growth performance.

Animals

A conserved distal-tail helical extension defines a tailspike attachment architecture in Gram-negative siphophages.

Rapid growth of bacteriophage genome collections has outpaced functional annotation of tail-tip proteins, limiting comparative analysis of host-recognition structures. Starting from a shared distal-tail gene organization in the Salmonella phages 9NA and Jersey, I developed a morphogenetic bioinformatic framework integrating gene synteny, sequence comparison, profile hidden Markov model (HMM) screening, structural evidence, structure-aware searching, and AlphaFold modeling. Comparison with the experimentally characterized lambda and Sf11 tail assemblies identified a predominantly alpha-helical C-terminal extension of the distal-tail (DT) protein associated with tailspike attachment, termed the distal-tail helical extension (DT-helix). Screening 541,986 proteins from 5167 complete NCBI RefSeq tailed-phage genomes, followed by evidence-based evaluation of sequence, genomic context, and structural architecture, identified 165 curated DT-helical-extension-associated phages. Their DT proteins segregated into six sequence groups. In the four principal multi-member groups, cognate tailspikes showed group-specific conservation in proximal N-terminal regions but substantially greater downstream diversity, consistent with sequence constraint at the DT-tailspike attachment boundary. A complementary ProstT5/Foldseek search supported the established groups but revealed no convincing additional highly divergent family. Together with the experimentally characterized Sf11 attachment interface, these findings define a recurrent morphogenetic architecture linking conserved distal-tail scaffolds to more variable receptor-binding proteins across siphophages infecting Gram-negative bacteria. Although universal exchangeability is not established, the identified scaffold-receptor-binding boundaries provide a framework for molecular characterization and rational phage engineering. Accession-level information for the 165 curated phages is available through PhageTailDB.

Viral Tail Proteins

Tranexamic acid in spontaneous&#x2002;intracerebral&#x2002;hemorrhage: an updated systematic review and meta-analysis of randomized controlled trials.

BACKGROUND: Tranexamic acid (TXA) is a well-established antifibrinolytic medication in the general population. However, its efficacy and safety for patients with spontaneous intracerebral hemorrhage (ICH) remain inconclusive. Consequently, we conducted a systematic review and meta-analysis to assess the effectiveness and safety of TXA for spontaneous ICH. METHODS: We conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) following established methodological standards. Our search encompassed eight electronic databases from inception to April 25, 2024. The primary outcome was a reduction in all-cause mortality. The secondary outcomes included improvements in functional independence, neurological impairment, activities of daily living, and reduction in hematoma expansion (HE). Fixed-effects or random-effects model&#xa0;were performed for pooled data where eligible. RESULTS: A total of 9 RCTs that initially enrolled 3,124 patients were included. There were no significant differences observed concerning all-cause mortality (RR, 1.03; 95% CI [0.89-1.18]), hematoma expansion (RR, 0.90; 95% CI [0.80-1.00]), improvement of functional independence (RR, 1.02; 95% CI [0.92-1.12], neurological impairment (MD, -0.88 [95% CI, -2.22-0.45]), or activities in daily living (MD, -0.83 [95% CI, -29.25-12.59]). The pooled data indicated that TXA for ICH was associated with a decrease in hematoma volume from baseline (MD, -1.74; 95% CI [-2.47 to -1.02]). No significant difference in adverse events was observed between the TXA group and the control group. CONCLUSIONS: In summary, TXA does not affect all-cause mortality, functional outcomes, or neurological impairment, nor does it reduce HE, despite reducing hematoma volulume. TXA use for ICH requires careful clinical consideration.

Humans

Phentermine/Topiramate in Obese, Diabetic Uric Acid Stone Formers: An Open-Label Randomized Feasibility Trial.

PURPOSE: The purpose of this study was to determine whether medical treatment of obesity, diabetes, and low urine pH with combination phentermine/topiramate affects uric acid (UA) kidney stone burden. MATERIALS AND METHODS: Participants with obesity, diabetes mellitus, normal renal function, urine pH < 5.8, and stone analysis &#x2265; 80% UA were block randomized (2:1 ratio) to phentermine 18.75 mg/topiramate 100 mg vs pragmatic controls for an 18-month, prospective, open-label feasibility study with dose escalation. The primary outcome was change in CT stone volume. Secondary outcomes included medication adherence; patient safety; and change in anthropometrics, laboratory studies, and body composition. RESULTS: Nineteen participants (age 62.1 &#xb1; 9.8 years; 68% male; mean BMI = 36.3 &#xb1; 2.9 kg/m2) were randomized, and 15 completed the study with 73% pill adherence and no serious adverse events. Stone volume by intention-to-treat analysis fell by 52% in the intervention group and rose by 8.6% in the control group (P = .10), with per-protocol analysis demonstrating statistically significant stone volume reduction (P = .02). At study end and compared with means of controls, the intervention group had greater weight loss (-10.2 vs +2.9 kg), reduction in hemoglobin A1c levels (-0.2 vs +0.5), lower 24-hour urine citrate (309 &#xb1; 81 vs 951 &#xb1; 782 mg), and lower UA supersaturation (0.7 &#xb1; 1.1 vs 1.8 &#xb1; 1.0), along with higher 24-hour urine pH (6.2 &#xb1; 0.5 vs 5.5 &#xb1; 0.4) and calcium phosphate supersaturation (0.9 &#xb1; 0.8 vs 0.2 &#xb1; 0.1; all P < .05). CONCLUSIONS: Among obese participants with diabetes mellitus and UA nephrolithiasis, phentermine/topiramate was well tolerated and demonstrated significant stone burden reductions by per-protocol analysis. The intervention group also had greater weight loss, higher urinary pH, and lower hemoglobin A1c and urinary citrate levels. These data provide a framework to study the impact of this novel alternative UA therapy on a wider range of patients with obesity and diabetes.

Aged

In situ product monitoring in heterogeneous reaction of gaseous trimethylamine on Fe2O3/Fe(NO3)3: Effect of environmental factor and particle property.

Gas-particle reactions represent an important atmospheric heterogeneous transformation process for organic amines (OAs). Environmental factors and particle properties may impact the gas-particle reaction products. Although the products from gas-particle reactions can be monitored by various in situ techniques, related data remain scarce. Here, the interfacial and gaseous products from the reaction of trimethylamine on Fe2O3/Fe(NO3)3 particles under light irradiation with mixed NO2, O2, SO2 and H2O were monitored using in-situ diffuse reflectance Fourier transform infrared spectroscopy and proton transfer reaction time-of-flight mass spectrometry. Dark reaction of gaseous trimethylamine on Fe2O3/Fe(NO3)3 generated two interfacial products types: N-containing ones (CH3NCH2, CH3NO2, (CH3)2NCHO, and CH3N(OH)CHO) and N-free ones (alcohols, aldehydes and acids), both accumulating with reaction progression. Light irradiation and O2 oxidation enhanced formation of these products, while NO2 promoted the production of CH3NO2 and (CH3)2NCHO. H2O and SO2 occupied the active sites of particles to inhibit the formation of all products. Compared to Fe(NO3)3, Fe2O3 showed absolute dominance in contribution to the formation of products. Considering the smaller particle size of Fe2O3 and excess Fe(NO3)3, the physical mixing of them reduced the generation of interfacial products. Furthermore, gaseous products of CH3OH, HCHO, CH3CHO, HCOOH and CH3COOH detection clarified the N-free interfacial products. The presence of Fe(NO3)3 inhibited the formation of HCOOH and favored the formation of CH3CHO in the gas phase. By combining product information with thermodynamic calculations, the heterogeneous reaction pathways of trimethylamine were tentatively proposed. These findings provide a guiding significance for the migration of OAs in real atmospheric environment.

Methylamines

Carboxyl group number and acidity of organic acids regulate structural reorganization and low glycemic index in cassava pyrodextrins via molecular interactions.

Transforming high-glycemic cassava starch into functional dietary fiber via pyrodextrinization is a promising way to valorize tuber crops, yet the molecular mechanisms catalyzed by organic acids with different carboxyl numbers and acidity remain unclear. This study investigates how carboxyl number and acidity of acetic acid (AA), tartaric acid (TA), and citric acid (CA) affect structural reorganization and low glycemic properties of cassava pyrodextrins. Compared with AA, TA, and CA with stronger acidity and more carboxyl groups promoted more extensive hydrolysis, transglycosylation, repolymerization, and esterification. These changes increased indigestible glycosidic linkages and the branching degree, while reducing molecular weight. Molecular docking confirmed stronger hydrogen-bonding interactions between TA/CA and starch chains. Furthermore, TA- and CA-catalyzed pyrodextrins exhibited superior anti-digestive properties with resistant starch up to 54.26% and an estimated glycemic index as low as 42.46, highlighting the critical role of carboxyl numbers and acidities in modulating the functionality of pyrodextrins.

Manihot

Transcriptomic and RNAi analyses reveal chloride channel 3-associated osmoregulation in Litopenaeus vannamei under low-salinity stress.

Chloride channels and transporters are important for cellular volume regulation and salinity adaptation in euryhaline crustaceans, yet the intestinal transcriptional relationship between plasma-membrane and intracellular chloride pathways remains unclear in Litopenaeus vannamei. In this study, RNA interference of anoctamin 1 (ANO1) was combined with intestinal transcriptome sequencing under the production-relevant low-salinity condition of salinity 3. ANO1 silencing produced a focused transcriptional response, with 16 differentially expressed genes (DEGs) identified (11 upregulated and 5 downregulated). Functional enrichment indicated that these genes were associated with transporter activity, cytoskeletal organization, extracellular matrix-receptor interaction, membrane lipid metabolism, and vesicular processes. Notably, a transcript encoding chloride channel protein 3 (CLC-3) was significantly upregulated following ANO1 knockdown, suggesting a potential transcriptional relationship between ANO1 and CLC-3 in chloride homeostasis. Based on this finding, CLC-3 was selected for full-length cDNA cloning, sequence characterization, salinity-gradient expression analysis, and RNAi-based functional assessment. The cloned CLC-3 cDNA was 2883&#xa0;bp in length and encoded an 850 amino acid protein containing a conserved voltage-gated chloride channel (Voltage-CLC) domain and two cystathionine &#x3b2;-synthase domains. Phylogenetic analysis placed LvCLC-3 within the intracellular CLC-c clade, and tissue distribution analysis showed the highest CLC-3 expression in the intestine. Intestinal CLC-3 expression responded nonlinearly to salinity variation, peaking at salinity 20. Under salinity 3, CLC-3 knockdown reduced ANO1, Na+/K+-ATPase alpha subunit, and Na+-K+-2Cl- cotransporter transcript levels, whereas glutamate-gated chloride channel expression increased. Mild hepatopancreatic structural alterations were also observed after CLC-3 knockdown. These findings suggest that CLC-3 is a salinity-responsive intracellular chloride-transporter candidate associated with intestinal ion-transport-related transcriptional responses after ANO1 suppression in L. vannamei, although the underlying physiological mechanism requires further validation.

Animals

Acetic acid-induced translational repression involves eIF2B body formation and Ded1 sequestration into stress granules in yeast.

Elucidating the physiological impact of acetic acid stress and the corresponding yeast responses is essential for advancing fundamental biology and improving industrial alcoholic fermentation. Despite numerous genome-wide studies, information on the effects of acetic acid stress on yeast translational regulation remains limited. We found that a sublethal concentration of acetic acid (35 mM, 0.2% v/v) causes translational repression, accompanied by the formation of eIF2B bodies and the phosphorylation of eIF2&#x3b1;, both of which are involved in the regulation of translation initiation. Acetic acid also caused the sequestration of Ded1, a DEAD-box RNA helicase crucial for translation initiation, into stress granules. Removal of acetic acid restored translational activity and the proper localization of eIF2B and Ded1, indicating the reversibility of acetic acid-induced translational repression. Furthermore, when yeast cells were pretreated with 0.05% acetic acid, translational repression under subsequent 0.2% acetic acid stress was attenuated in wild-type cells but not in hrk1&#x394; cells. This indicates that Hrk1, a Pma1 activator, is required to sufficiently enhance tolerance to acetic acid-induced translational repression. These findings provide novel insights into the physiological effects of acetic acid stress on translational activity and translation-related factors in yeast cells.

Saccharomyces cerevisiae

A horizontally acquired gene mediates insect cocoon pigmentation in the eri silkmoth, Samia ricini.

Holometabolous insects make cocoons during larval-pupal metamorphosis to protect the pupal phase. The materials used for cocoon construction vary widely. Lepidopteran insects typically secrete silk to form cocoons, which display diverse colors. The eri silkworm, Samia cynthia ricini, is an economically important domesticated species that mostly produces white cocoons, with some varieties producing red cocoons. The enzyme kynureninase (KYNU), acquired from bacteria by horizontal gene transfer, has previously been implicated in insect coloration, while the tryptophan metabolite 3-hydroxyanthranilic acid (3-HAA) has been identified as a red pigment. However, exactly how KYNU is involved in cocoon pigmentation remains unclear. Here, we report that a horizontally transferred bacterial gene encoding KYNU regulates red cocoon formation. Metabolomic analysis revealed a high accumulation of 3-HAA in red cocoons, confirming its role as the primary pigment and associating the coloration with tryptophan metabolism. Quantitative real-time polymerase chain reaction (qPCR) analysis indicated that SrKYNU is highly expressed in the silk glands and significantly downregulated in the red cocoon strain compared to the white cocoon strain. Genomic sequencing identified a 141 bp deletion in the upstream regulatory region of KYNU in the red cocoon strain compared to the white cocoon strain. Dual-luciferase assays confirmed that this deletion significantly reduced promoter activity. CRISPR/Cas9 knockout of SrKYNU in the white-cocoon strain resulted in mutants producing red cocoons with elevated 3-HAA content. These findings reveal that the horizontally transferred gene SrKYNU exhibits tissue-specific expression and regulates cocoon coloration in S. ricini, illustrating that horizontal gene transfer can play an important role in regulating an insect physiological process.

Animals