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1.
Food Chem ; 462: 140987, 2025 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-39217748

RESUMO

This study aimed to investigate the textural changes of cooked germinated brown rice (GBR) during freeze-thaw treatment and propose a strategy for enhancing its texture using magnetic field (MF). Seven freeze-thaw cycles exhibited more pronounced effects compared to 7 days of freezing, resulting in increases in GBR hardness by 85.59 %-164.36 % and decreases in stickiness by 10.34 %-43.55 %. Water loss, structural damage of GBR flour, and starch retrogradation contributed to the deterioration of texture. MF mitigated these effects by inhibiting the transformation of bound water into free water, reducing water loss by 0.39 %-0.57 %, and shortening the phase transition period by 2.0-21.5 min, thereby diminishing structural damage to GBR flour and hindering starch retrogradation. Following MF treatment (5 mT), GBR hardness decreased by 21.00 %, while stickiness increased by 45.71 %. This study elucidates the mechanisms through which MF enhances the texture, offering theoretical insights for the industrial production of high-quality frozen rice products.


Assuntos
Culinária , Congelamento , Germinação , Campos Magnéticos , Oryza , Oryza/química , Oryza/crescimento & desenvolvimento , Oryza/metabolismo , Farinha/análise , Amido/química , Amido/metabolismo , Água/química , Dureza , Manipulação de Alimentos , Sementes/química , Sementes/crescimento & desenvolvimento
2.
J Ethnopharmacol ; 336: 118722, 2025 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-39182704

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Triptolide is a major bioactive and toxic ingredient isolated from the traditional Chinese herb Tripterygium wilfordii (T. wilfordii) Hook F. It exhibits potent antitumor, immunosuppressive, and anti-inflammatory biological activities; however, its clinical application is hindered by severe systemic toxicity. Two preparations of T. wilfordii, including T. wilfordii glycoside tablets and T. wilfordii tablets, containing triptolide, are commonly used in clinical practice. However, their adverse side effects, particularly hepatotoxicity, limit their safe use. Therefore, it is crucial to discover potent and specific detoxification medicines for triptolide. AIM OF THE STUDY: This study aimed to investigate the detoxification effects and potential mechanism of action of spironolactone on triptolide-induced hepatotoxicity to provide a potential detoxifying strategy for triptolide, thereby promoting the safe applications of T. wilfordii preparations in clinical settings. MATERIALS AND METHODS: Cell viability was assessed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and crystal violet staining. Nuclear fragmentation was visualized using 4',6-diamidino-2-phenylindole (DAPI) staining, and protein expression was analyzed by Western blotting. The inhibitory effect of spironolactone on triptolide-induced hepatotoxicity was evaluated by examining the effects of spironolactone on serum alanine aminotransferase and aspartate aminotransferase levels, as well as liver pathology in a mouse model of triptolide-induced acute hepatotoxicity. Furthermore, a survival assay was performed to investigate the effects of spironolactone on the survival rate of mice exposed to a lethal dose of triptolide. The effect of spironolactone on triptolide-induced global transcriptional repression was assessed through 5-ethynyl uridine staining. RESULTS: Triptolide treatment decreased the cell viability, increased the nuclear fragmentation and the cleaved caspase-3 levels in both hepatoma cells and hepatocytes. It also increased the alanine aminotransferase and aspartate aminotransferase levels, induced the hepatocyte swelling and necrosis, and led to seven deaths out of 11 mice. The above effects could be mitigated by pretreatment with spironolactone. Additionally, molecular mechanism exploration unveiled that spironolactone inhibited triptolide-induced DNA-directed RNA polymerase II subunit RPB1 degradation, consequently increased the fluorescence intensity of 5-ethynyl uridine staining for nascent RNA. CONCLUSIONS: This study shows that spironolactone exhibits a potent detoxification role against triptolide hepatotoxicity, through inhibition of RPB1 degradation induced by triptolide and, in turn, retardation of global transcriptional inhibition in affected cells. These findings suggest a potential detoxification strategy for triptolide that may contribute to the safe use of T. wilfordii preparations.


Assuntos
Doença Hepática Induzida por Substâncias e Drogas , Diterpenos , Compostos de Epóxi , Fenantrenos , Espironolactona , Compostos de Epóxi/toxicidade , Fenantrenos/toxicidade , Fenantrenos/farmacologia , Diterpenos/farmacologia , Diterpenos/toxicidade , Animais , Doença Hepática Induzida por Substâncias e Drogas/tratamento farmacológico , Doença Hepática Induzida por Substâncias e Drogas/patologia , Camundongos , Espironolactona/farmacologia , Masculino , Humanos , Sobrevivência Celular/efeitos dos fármacos , Fígado/efeitos dos fármacos , Fígado/patologia , Fígado/metabolismo , Células Hep G2
3.
Curr Top Med Chem ; 2024 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-39350415

RESUMO

AIMS: The aim of the current study was to explore the anti-diabetic potential of Ochradenus aucheri Boiss (O. aucheri). METHOD: All the fractions of O. aucheri were evaluated for α-glucosidase inhibition, followed by bioassay-guided isolation which resulted in a new sesquiterpenoid, as a potential α-glucosidase inhibitor. RESULTS: The preliminary screening showed that all the fractions including n-hexane (38.0 ± 1.38 µg/mL), dichloromethane (92.6 ± 6.18 µg/mL), ethyl acetate (29.2 ± 0.51 µg/mL) and n-butanol (361.8 ± 5.80 µg/mL) displayed significant α-glucosidase inhibitory activity. The activity-directed fractionation and purification of ethyl acetate fraction led to the isolation of one new sesquiterpenoid, Jardenol (1), and two known metabolites: ß-stitosterol-3-O-ß-D-glucopyranoside (2) and ß-Sitosterol (3). To the best of our knowledge, these metabolites have not been isolated from this plant previously. The structure of the new metabolite 1 was confirmed through 1D and 2D NMR spectroscopy, and MS analysis. Compound 1 showed significant α-glucosidase inhibition with an IC50 value of 138.2 ± 2.43 µg/mL as compared to positive control acarbose (IC50 = 942.0 ± 0.60 µg/mL). Additionally, in-silico docking was employed to predict the binding mechanism of compound 1 in the active site of the target enzyme, α-glucosidase. The docking results suggested that the compound forms strong interactions at the catalytic site of α-glucosidase. CONCLUSION: The results of the present study indicated that the newly purified secondary metabolite, Jardenol, can be a promising anti-diabetic compound.

4.
J Agric Food Chem ; 2024 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-39352105

RESUMO

Amino acids are necessary for life, and many must be consumed because they cannot be endogenously synthesized. Typically, we eat them as proteins and peptides, which have little taste. However, we also directly ingest free amino acids, several of which are aversive because they elicit bitterness. This bitterness often prevents many patient populations from taking formulas and supplements containing free amino acids. Here, we characterize which amino acids are the most bitter, their concentration-intensity functions, and individual differences in bitterness perception, and we explore how sodium salts suppress the bitterness of amino acids. We found that the essential amino acids comprise the most bitter stimuli, with six of them conveying the most bitterness. Clustering and correlating amino acids by individual differences in bitterness perception show that there are approximately four groupings of amino acids and suggest that within these clusters, amino acids may be activating the same or overlapping TAS2Rs. We also show that bitterness can be largely suppressed by sodium salts for 5 of the 6 most bitter amino acids. These results hold promise for managing the bitter taste of nutritional supplements that contain amino acids and improving compliance.

5.
Nano Lett ; 2024 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-39352880

RESUMO

The accumulation of abnormal protein deposits known as amyloid-ß (Aß) plaques contributes to the development and progression of Alzheimer's disease. Aggregated Aß exacerbates oxidative stress by stimulating the production of reactive oxygen species (ROS) in a detrimental feedback loop. 8-Hydroxyquinoline (8-HQ) is recognized for its ability to inhibit or reverse Aß aggregation and reduce neurotoxicity. Here, an 8-HQ-based polymer, DHQ, was developed to combat Aß-mediated neurotoxicity by delivering an antioxidant enzyme. DHQ efficiently delivers superoxide dismutase into targeted cells, thereby downregulating the intracellular ROS level. Additionally, the polymer effectively inhibits the fibrillization of three proteins involved in fibrosis, ß-lactoglobulin (BLG), insulin, and Aß1-40, at nanomolar concentrations. Cell culture models demonstrated that DHQ reduces ROS levels induced by Aß1-40 aggregation, rescuing cell viability and preventing apoptosis. Intracellular delivery of SOD further enhanced the ability to maintain the ROS homeostasis. This polymer offers a multifaceted approach to treating diseases associated with amyloidosis.

6.
Dev Cogn Neurosci ; 70: 101454, 2024 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-39357147

RESUMO

Cognitive control processes likely influence the extent to which adolescents can successfully regulate their emotions. This study examined whether individual differences in affective inhibition and heart rate variability (HRV), as a peripheral index of cognitive control, moderated the association between momentary emotion regulation and negative affect (NA). Ecological Momentary Assessments (EMA) over 14 days were obtained in 235 adolescents (Mage = 13.48 years; 106 females). At each assessment, participants reported their current NA and the extent to which they used cognitive reappraisal and rumination. Moreover, at three time points (approximately 1 year, 6 months, and just before the EMA), affective inhibition was assessed using an affective go/no-go task and HRV was recorded at rest. Results indicate that adolescents with lower affective inhibition reported lower average levels of daily rumination. However, affective inhibition did not moderate the association between either daily cognitive reappraisal or rumination and momentary NA. Consistent with hypotheses, the association between momentary rumination and NA was weaker in adolescents showing higher levels of resting HRV. Overall, findings may underscore the importance of interventions targeting HRV as a malleable factor for enhancing adolescents' affective well-being.

7.
J Colloid Interface Sci ; 679(Pt A): 64-74, 2024 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-39357227

RESUMO

The stability and high-dose addition of carbon dots in corrosion and scale inhibition are obstacles to their commercial application. Herein, we report a new type of functional CDs (PEI-CDA) based on Angelica residue and polyethyleneimine (PEI), which can remarkably boost the performance of corrosion and scale inhibition, while expending the application of traditional Chinese medicine waste residue. At 303.15 K, the corrosion inhibition efficiency of PEI-CDA for carbon steel in 1.0 M HCl medium was tested by weight loss method and electrochemical method and reached over 93 %, which is significantly better than that of CDA (83 %) under the same conditions. And its corrosion inhibition efficiency can still remain stable after 15 h. The ultra-low dose (5 mg·L-1) PEI-CDA has excellent anti-corrosion protection effect on carbon steel due to its ability to form a dense and well-organized adsorption film covering on the carbon steel surface, whose adsorption includes two types of chemical and physical adsorption, and follows the Langmuir adsorption model. Furthermore, static methods display that the CaSO4 scale inhibition efficiency of PEI-CDA is up to 100 % when its dosage is 100 mg·L-1. Analysis of the generated CaSO4 scale shows that the addition of PEI-CDA causes lattice distortion, chelation, and dispersion of scale. In addition, the fluorescence spectra imply that PEI-CDA can be expected to on-line detection of its residual content in the water system. The results demonstrate that PEI-CDA possesses significant potential in green inhibitors and the comprehensive utilization of waste resources.

8.
Child Neuropsychol ; : 1-18, 2024 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-39359060

RESUMO

The Hayling Completion Sentence Test (HSCT) is dedicated to assess inhibition of the dominant response and includes two conditions, an automatic condition in which the participants are asked to complete sentences properly and an inhibition condition in which the participants were asked to produce a word completely unrelated to the sentence. The aim of our study was 1) to adapt, 2) to evaluate the psychometric properties and 3) to standardize the HSCT into a French-school-aged pediatric population. We developed the Child-Hayling Test, a child adaptation of the adult French version of the HSCT. The reliability and validity of the Child-Hayling Test were then evaluated in a sample of 134 children aged 6-11 years. In the inhibition condition, children had lower response latency, as they get older. No effect of gender was observed. Reliability indices were low to moderate. Concerning the convergent and divergent validity, response latencies in the Child-Hayling Test correlated with latency scores in the Barre-Joe inhibition test, whereas the Child-Hayling Test scores were not related to children's lexical abilities. The Child-Hayling Test was then administered to 393 typically developing 6- to 11-year-old children. Normative data were calculated in the inhibition condition using a regression-based approach. Regression equations to calculate Z scores are provided for clinical use. In addition, we proposed a clear guideline on how to score children's inhibition responses. The Child-Hayling Test provides a useful tool for assessing prepotent response inhibition in children and can be recommended for use in clinical research and practice.

9.
J Virol ; : e0118624, 2024 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-39360825

RESUMO

Neuraminidase (NA)-specific antibodies have been associated with protection against influenza and thus NA is considered a promising target for next-generation vaccines against influenza A (IAV) and B viruses (IBV). NA inhibition (NI) by antibodies is typically assessed using an enzyme-linked lectin assay (ELLA). However, ELLA can be confounded by anti-hemagglutinin (anti-HA) antibodies that block NA by steric hindrance (termed HA interference). Although strategies have been employed to overcome HA interference for IAV, similar approaches have not been assessed for IBV. We found that HA interference is common in ELLA using IBV, rendering the technique unreliable. Anti-HA antibodies were not completely depleted from sera by HA-expressing cell lines, and this approach was of limited utility. In contrast, we find that treatment of virions with Triton X-100, but not Tween-20 or ether, efficiently separates the HA and NA components and overcomes interference caused by anti-HA antibodies. We also characterize a panel of recombinant IBV NA proteins that further validated the results from Triton X-100-treated virus-based ELLA. Using these reagents and assays, we demonstrate discordant antigenic evolution between IBV NA and HA over the last 80 years. This optimized ELLA protocol will facilitate further in-depth serological surveys of IBV immunity as well as antigenic characterization of the IBV NA on a larger scale.IMPORTANCEInfluenza B viruses (IBVs) contribute to annual epidemics and may cause severe disease, especially in children. Consequently, several approaches are being explored to improve vaccine efficacy, including the addition of neuraminidase (NA). Antigen selection and assessment of serological responses will require a reliable serological assay to specifically quantify NA inhibition (NI). Although such assays have been assessed for influenza A viruses (IAVs), this has not been done of influenza B viruses. Our study identifies a readily applicable strategy to measure the inhibitory activity of neuraminidase-specific antibodies against influenza B virus without interference from anti-hemagglutinin (anti-HA) antibodies. This will aid broader serological assessment of influenza B virus-specific antibodies and antigenic characterization of the influenza B virus neuraminidase.

10.
Neuroimage Clin ; 44: 103677, 2024 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-39362044

RESUMO

Deficiencies in inhibitory control are one of the hallmarks of attention-deficit-(hyperactivity) disorder (AD(H)D). Response inhibition demands can become increased through additional conflicts, namely when already integrated representations of perception-action associations have to be updated. Yet, the neural mechanisms of how such conflicts worsen response inhibition in AD(H)D are unknown, but, if identified, could help to better understand the complex nature of AD(H)D-associated impulsivity. We investigated both behavioral performance and EEG activity in the theta and alpha band of adolescents (10-18 years of age) with AD(H)D (n = 28) compared to neurotypical (NT) controls (n = 33) in a conflict-modulated Go/Nogo paradigm. We used multivariate pattern analysis (MVPA) and EEG-beamforming to examine how changes in representational content are coded by oscillatory activity and to delineate the cortical structures involved in it. The presented behavioral and neurophysiological data show that adolescents with AD(H)D are more strongly affected by increased response inhibition demands through additional conflicts than NT controls. Precisely, AD(H)D participants showed higher false alarm rates than NT controls in both, non-overlapping and overlapping Nogo trials, but performed even worse in the latter. This is likely due to an inefficient updating of representations related to delayed modulations of alpha band activity in the ventral stream and orbitofrontal regions. Theta band activity is also modulated by conflict but was not differentially affected in the two groups. By this, the present study provides novel insights into underlying neurophysiological mechanisms of the complex nature of response inhibition deficits in adolescents with AD(H)D, stressing the importance to examine the interplay of theta and alpha band activity more closely to better understand inhibitory control deficits in AD(H)D.

11.
Chemistry ; : e202403035, 2024 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-39354660

RESUMO

Achieving food sustainability is one of the biggest challenges in the new millennium. Plant factory cultivation systems provide an alternative for food sustainability, while they often suffer from algal blooms. The overuse of conventional algaecides has caused significant environmental pollution and concerns about food security. Here, we design a nanoenabled metal-organic algaecide that is self-assembled from natural polyphenols and two functional metal ions for providing shading effects and delivering active ingredients synergistically to suppress algal blooms. Black wattle tannin (BWT) and Fe3+ ions are utilized to develop self-assembled FeBWT nanoalgaecides with significant shading effects for decreasing light transmission (up to 97%) and effectively inhibiting algal photosynthesis. Further, the FeBWT is functionalized with Cu2+ ions (bimetallic Cu/FeBWT) to target the algal cells and release Cu2+ ions via phenolic-mediated cell surface interactions, thus enhancing the inhibition efficiency. Importantly, the biosafety of Cu/FeBWT is demonstrated through toxicity tests on zebrafish and NIH3T3 cells. In our real-world field test, the Cu/FeBWT demonstrates high algal inhibition performance (> 95%, over 30 days), and enhances the accumulation of food nutrients in model plant lettuces. Collectively, the supramolecular metal-organic nanoalgaecide provides a promise for nanoagrochemical application and promoting food sustainability and security.

12.
J Agric Food Chem ; 2024 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-39356107

RESUMO

The biosynthesis of amino acid derivatives of animal origin in plants represents a promising frontier in synthetic biology, offering a sustainable and eco-friendly approach to enhancing the nutritional value of plant-based diets. This study leverages the versatile capabilities of Nicotiana benthamiana as a transient expression system to test a synthetic modular framework for the production of creatine, carnosine, and taurine-compounds typically absent in plants but essential for human health. By designing and stacking specialized synthetic modules, we successfully redirected the plant metabolic flux toward the synthesis of these amino acid derivatives of animal origin. Our results revealed the expression of a standalone creatine module resulted in the production of 2.3 µg/g fresh weight of creatine in N. benthamiana leaves. Integrating two modules significantly carnosine yield increased by 3.8-fold and minimized the impact on plant amino acid metabolism compared to individual module application. Unexpectedly, introducing the taurine module caused a feedback-like inhibition of plant cysteine biosynthesis, revealing complex metabolic adjustments that can occur when introducing foreign pathways. Our findings underline the potential for employing plants as biofactories for the sustainable production of essential nutrients of animal origin.

13.
ACS Biomater Sci Eng ; 2024 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-39365184

RESUMO

In response to the challenges faced by clinicians treating bone defects caused by various factors, various bone repair materials have been investigated, but the efficiency of bone healing still needs to be improved due to the acting of scaffolds only in a single stage of bone tissue regeneration. We investigated the potential of a novel 3D scaffold to support different stages of bone tissue regeneration, including initial inflammation, proliferation, and remodeling. Eu (0, 0.5, 2, 3.5, 5, and 6.5%) was added to calcium polyphosphate to obtain 3D porous network-doped Eu calcium polyphosphate (EuCPP) scaffolds with ideal mechanical strength and pore size. Both in vitro and in vivo experiments proved that Eu3+ released from 5% EuCPP scaffolds could significantly promote the migration and proliferation of bone marrow stromal cells which effectively promote angiogenesis; 5% EuCPP could significantly upregulate the ratio of OPG/RANKL in MC3T3-E1 and promote the secretion of osteogenic-related growth factors (ALP and OPN) from MC3T3-E1, indicating the potential of the scaffold to inhibit bone resorption and promote bone formation. In conclusion, 5% EuCPP possesses the biological properties of pro-angiogenesis, anti-inflammation, pro-osteogenesis, and inhibiting bone resorption, which may provide a sustained positive effect throughout the process of bone tissue repair.

14.
Future Oncol ; : 1-11, 2024 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-39378065

RESUMO

Asparagine synthetase (ASNS) catalyzes the biosynthesis of asparagine from aspartate and glutamine. Cells lacking ASNS, however, are auxotrophic for asparagine. Use of L-asparaginase to promote asparagine starvation in solid tumors with low ASNS levels, such as pancreatic ductal adenocarcinoma (PDAC), is a rationale treatment strategy. However, tumor cell resistance to L-asparaginase has limited its clinical utility. Our preclinical studies show that RAS/MAPK signaling circumvents L-asparaginase-induced tumor killing, but L-asparaginase and MEK inhibition potentiated tumor killing; suggesting that this combination may provide meaningful clinical benefit to patients with PDAC. This Phase I trial (NCT05034627) will evaluate the safety and tolerability of the MEK inhibitor, cobimetinib, in combination with pegylated L-asparaginase, L calaspargase pegol-mknl, in patients with locally-advanced or metastatic PDAC.


[Box: see text].

15.
Food Chem Toxicol ; 193: 115028, 2024 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-39368542

RESUMO

This study explores the phytochemical composition and biological activities of Verbascum yemenense, a plant known for its medicinal properties. The plant extract revealed a rich presence of bioactive compounds that exhibited significant antioxidant properties against free radicals. The enzyme inhibition potential was particularly notable against cholinesterases (AChE: 2.56 mg GALAE/g; BChE: 1.98 mg GALAE/g), and tyrosinase (87.94 mg KAE/g), α-glucosidase suggesting potential therapeutic applications in neurodegenerative diseases, skin disorders and diabetes. Molecular docking studies and Molecular Dynamics simulations, providing insights into the interaction mechanisms of the identified compounds with the target proteins. Molecular docking studies revealed high binding affinities of the phytoconstituents, with compounds like VY4 and phyllanthusol-A (VY15) showing substantial docking scores against AChE (-9.840 kcal/mol) and BChE (-9.853 kcal/mol), respectively. For instance, the RMSD values during the MD simulations for compound VY17 in the AML complex showed a stable conformation, fluctuating within a range of 0.75 Å to 1.75 Å, indicating a strong and consistent interaction with the enzyme. MESP studies highlighted VY17's distinctive electrostatic features, notably a pronounced electronegative region, which might contribute to its binding efficiency. These findings suggest that V. yemenense is a promising candidate for developing novel therapeutic agents.

16.
Saudi Med J ; 45(10): 1064-1070, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39379119

RESUMO

OBJECTIVES: To ascertain the prevalence of ABH antigen secretors and non-secretors among Yemenis. In addition to explore the factors that may affect the expression of the secretion phenotype. METHODS: This cross-sectional study was carried out between May and September 2022 on 215 healthy Yemeni individuals at the International Malaysian University, Ibb, Yemen. The participants were tested for blood group antigen on their blood samples using standard test tube method using the suitable ABH antisera. Saliva was collected and tested for secretion using hemagglutination inhibition test with suitable A, B, and H antisera. Before collecting the blood samples, informed consent was obtained from each participant and complete data and history questionnaire were collected by the research team. RESULTS: In general, 78.1% of Yemini participants were found to be secretor (80% men and 73.3% females). This percentage increased within O blood group (95%) and decreased within AB blood group (54%) individuals. Both O and AB blood groups showed statistically significant association with secretor trait. Also, it was noticed that age advance increases the expression of Se gene. In addition, the secretor state increased among Rh-negative people. CONCLUSION: The frequency of ABH secretors was 78.1% among Ibb province population in Yemen. Blood group O revealed the greatest frequency (95%), whereas blood group AB showed the lowest secretor frequency (54%). The secretor phenotype was highly expressed gradually with advance age then decline.


Assuntos
Sistema ABO de Grupos Sanguíneos , Fenótipo , Humanos , Sistema ABO de Grupos Sanguíneos/genética , Masculino , Feminino , Estudos Transversais , Iêmen , Adulto , Pessoa de Meia-Idade , Adulto Jovem , Fatores Etários , Saliva/metabolismo , Saliva/química , Adolescente
17.
ACS Synth Biol ; 2024 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-39383016

RESUMO

l-Threonine, an essential amino acid, is widely used in various industries, with an annually growing demand. However, the present Corynebacterium glutamicum strains are difficult to achieve industrialization of l-threonine due to low yield and purity. In this study, we engineered an l-isoleucine-producing C. glutamicum WM001 to efficiently produce l-threonine by finely regulating the carbon flux. First, the threonine dehydratase in WM001 was mutated to lower the level of l-isoleucine production, then the homoserine dehydrogenase and aspartate kinase were mutated to release the feedback inhibition of l-threonine, and the resulting strain TWZ006 produced 14.2 g/L l-threonine. Subsequently, aspartate ammonia-lyase and aspartate transaminase were overexpressed to accumulate the precursor l-aspartate. Next, phosphoenolpyruvate carboxylase, pyruvate carboxylase and pyruvate kinase were overexpressed, and phosphoenolpyruvate carboxykinase, oxaloacetate decarboxylase were inactivated to fine-regulate the carbon flux among oxaloacetate, pyruvate and phosphoenolpyruvate. The resulting strain TWZ017 produced 21.5 g/L l-threonine. Finally, dihydrodipicolinate synthase was mutated with strong allosteric inhibition from l-lysine to significantly decrease byproducts accumulation, l-threonine export was optimized, and the final engineered strain TWZ024/pXTuf-thrE produced 78.3 g/L of l-threonine with the yield of 0.33 g/g glucose and the productivity of 0.82 g/L/h in a 7 L bioreactor. To the best of our knowledge, this represents the highest l-threonine production in C. glutamicum, providing possibilities for industrial-scale production.

18.
Mol Cell ; 2024 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-39383878

RESUMO

Poly (ADP-ribose) polymerase (PARP) 1 and 2 enzymatic inhibitors (PARPi) are promising cancer treatments. But recently, their use has been hindered by unexplained severe anemia and treatment-related leukemia. In addition to enzymatic inhibition, PARPi also trap PARP1 and 2 at DNA lesions. Here we report that, unlike Parp2-/- mice, which develop normally, mice expressing catalytically inactive Parp2 (E534A and Parp2EA/EA) succumb to Tp53- and Chk2-dependent erythropoietic failure in utero, mirroring Lig1-/- mice. While DNA damage mainly activates PARP1, we demonstrate that DNA replication activates PARP2 robustly. PARP2 is selectively recruited and activated by 5'-phosphorylated nicks (5'p-nicks), including those between Okazaki fragments, resolved by ligase 1 (Lig1) and Lig3. Inactive PARP2, but not its active form or absence, impedes Lig1- and Lig3-mediated ligation, causing dose-dependent replication fork collapse, which is detrimental to erythroblasts with ultra-fast forks. This PARylation-dependent structural function of PARP2 at 5'p-nicks explains the detrimental effects of PARP2 inactivation on erythropoiesis, shedding light on PARPi-induced anemia and the selection for TP53/CHK2 loss.

19.
Fungal Biol ; 128(7): 2190-2196, 2024 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-39384288

RESUMO

Heavy metal Cd2+ can easily be accumulated by fungi, causing significant stress, with the fungal cell membrane being one of the primary targets. However, the understanding of the mechanisms behind this stress remains limited. This study investigated the changes in membrane lipid molecules of Pleurotus ostreatus mycelia under Cd2+ stress and the antagonistic effect of Ca2+ on this stress. Cd2+ in the growth media significantly inhibited mycelial growth, with increasing intensity at higher concentrations. The addition of Ca2+ mitigated this Cd2+-induced growth inhibition. Lipidomic analysis showed that Cd2+ reduced membrane lipid content and altered lipid composition, while Ca2+ counteracted these changes. The effects of both Cd2+ and Ca2+ on lipids are dose dependent and phosphatidylethanolamine appeared most affected. Cd2+ also caused a phosphatidylcholine/phosphatidylethanolamine ratio increase at high concentrations, but Ca2+ helped maintain normal levels. The acyl chain length and unsaturation of lipids remained unaffected, suggesting Cd2+ doesn't alter acyl chain structure of lipids. These findings suggest that Cd2+ may affect the growth of mycelia by inhibiting the synthesis of membrane lipids, particular the synthesis of phosphatidylethanolamine, providing novel insights into the mechanisms of Cd2+ stress in fungi and the role of Ca2+ in mitigating the stress.


Assuntos
Cádmio , Cálcio , Micélio , Fosfatidiletanolaminas , Pleurotus , Pleurotus/crescimento & desenvolvimento , Pleurotus/metabolismo , Pleurotus/efeitos dos fármacos , Fosfatidiletanolaminas/metabolismo , Cádmio/metabolismo , Cádmio/farmacologia , Micélio/crescimento & desenvolvimento , Micélio/efeitos dos fármacos , Micélio/metabolismo , Cálcio/metabolismo , Lipídeos de Membrana/metabolismo , Membrana Celular/efeitos dos fármacos , Membrana Celular/metabolismo , Membrana Celular/química , Meios de Cultura/química
20.
Immuno ; 4(1): 108-124, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-39391865

RESUMO

The SARS-CoV-2 pandemic ignited global efforts to rapidly develop testing, therapeutics, and vaccines. However, the rewards of these efforts were slow to reach many low- to middle-income countries (LMIC) across the African continent and globally. Therefore, two bead-based multiplexed serological assays were developed to determine SARS-CoV-2 exposure across four counties in Liberia. This study was conducted during the summer of 2021 on 189 samples collected throughout Grand Bassa, Bong, Margibi, and Montserrado counties. Our multiplexed immunoassay (MIA) detected elevated exposure to SARS-CoV-2 and multiple variant antigens. Additionally, we detected evidence of exposure to Dengue virus serotype 2, Chikungunya virus, and the seasonal coronavirus NL63. Our multiplexed inhibition test (MINT) was developed from the MIA to observe antibody-mediated inhibition of SARS-CoV-2 spike protein binding to its cognate cellular receptor ACE-2. We detected inhibitory antibodies in the tested Liberian samples, which were collectively consistent with a convalescent serological profile. These complementary assays serve to supplement existing serological testing needs and may enhance the technical capacity of scientifically underrepresented regions globally.

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