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1.
Enzyme Microb Technol ; 179: 110472, 2024 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-38889604

RESUMO

Lipases play a vital role in various biological processes, from lipid metabolism to industrial applications. However, the ever-evolving challenges and diverse substrates necessitate the continual exploration of novel high-performance lipases. In this study, we employed an in silico mining approach to search for lipases with potential high sn-1,3 selectivity and catalytic activity. The identified novel lipase, PLL, from Paenibacillus larvae subsp. larvae B-3650 exhibited a specific activity of 111.2 ± 5.5 U/mg towards the substrate p-nitrophenyl palmitate (pNPP) and 6.9 ± 0.8 U/mg towards the substrate olive oil when expressed in Escherichia coli (E. coli). Computational design of cysteine mutations was employed to enhance the catalytic performance of PLL. Superior stability was achieved with the mutant K7C/A386C/H159C/K108C (2M3/2M4), showing an increase in melting temperature (Tm) by 1.9°C, a 2.05-fold prolonged half-life at 45°C, and no decrease in enzyme activity. Another mutant, K7C/A386C/A174C/A243C (2M1/2M3), showed a 4.9-fold enhancement in specific activity without compromising stability. Molecular dynamics simulations were conducted to explore the mechanisms of these two mutants. Mutant 2M3/2M4 forms putative disulfide bonds in the loop region, connecting the N- and C-termini of PLL, thus enhancing overall structural rigidity without impacting catalytic activity. The cysteines introduced in mutant 2M1/2M3 not only form new intramolecular hydrogen bonds but also alter the polarity and volume of the substrate-binding pocket, facilitating the entry of large substrate pNPP. These results highlight an efficient in silico exploration approach for novel lipases, offering a rapid and efficient method for enhancing catalytic performance through rational protein design.

2.
Comput Methods Programs Biomed ; 254: 108295, 2024 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-38905987

RESUMO

BACKGROUND AND OBJECTIVE: To evaluate the feasibility and accuracy of radiomics, dosiomics, and deep learning (DL) in predicting Radiation Pneumonitis (RP) in lung cancer patients underwent volumetric modulated arc therapy (VMAT) to improve radiotherapy safety and management. METHODS: Total of 318 and 31 lung cancer patients underwent VMAT from First Affiliated Hospital of Wenzhou Medical University (WMU) and Quzhou Affiliated Hospital of WMU were enrolled for training and external validation, respectively. Models based on radiomics (R), dosiomics (D), and combined radiomics and dosiomics features (R+D) were constructed and validated using three machine learning (ML) methods. DL models trained with CT (DLR), dose distribution (DLD), and combined CT and dose distribution (DL(R+D)) images were constructed. DL features were then extracted from the fully connected layers of the best-performing DL model to combine with features of the ML model with the best performance to construct models of R+DLR, D+DLD, R+D+DL(R+D)) for RP prediction. RESULTS: The R+D model achieved a best area under curve (AUC) of 0.84, 0.73, and 0.73 in the internal validation cohorts with Support Vector Machine (SVM), XGBoost, and Logistic Regression (LR), respectively. The DL(R+D) model achieved a best AUC of 0.89 and 0.86 using ResNet-34 in training and internal validation cohorts, respectively. The R+D+DL(R+D) model achieved a best performance in the external validation cohorts with an AUC, accuracy, sensitivity, and specificity of 0.81(0.62-0.99), 0.81, 0.84, and 0.67, respectively. CONCLUSIONS: The integration of radiomics, dosiomics, and DL features is feasible and accurate for the RP prediction to improve the management of lung cancer patients underwent VMAT.

3.
Radiat Oncol ; 19(1): 72, 2024 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-38851718

RESUMO

BACKGROUND: To integrate radiomics and dosiomics features from multiple regions in the radiation pneumonia (RP grade ≥ 2) prediction for esophageal cancer (EC) patients underwent radiotherapy (RT). METHODS: Total of 143 EC patients in the authors' hospital (training and internal validation: 70%:30%) and 32 EC patients from another hospital (external validation) underwent RT from 2015 to 2022 were retrospectively reviewed and analyzed. Patients were dichotomized as positive (RP+) or negative (RP-) according to CTCAE V5.0. Models with radiomics and dosiomics features extracted from single region of interest (ROI), multiple ROIs and combined models were constructed and evaluated. A nomogram integrating radiomics score (Rad_score), dosiomics score (Dos_score), clinical factors, dose-volume histogram (DVH) factors, and mean lung dose (MLD) was also constructed and validated. RESULTS: Models with Rad_score_Lung&Overlap and Dos_score_Lung&Overlap achieved a better area under curve (AUC) of 0.818 and 0.844 in the external validation in comparison with radiomics and dosiomics models with features extracted from single ROI. Combining four radiomics and dosiomics models using support vector machine (SVM) improved the AUC to 0.854 in the external validation. Nomogram integrating Rad_score, and Dos_score with clinical factors, DVH factors, and MLD further improved the RP prediction AUC to 0.937 and 0.912 in the internal and external validation, respectively. CONCLUSION: CT-based RP prediction model integrating radiomics and dosiomics features from multiple ROIs outperformed those with features from a single ROI with increased reliability for EC patients who underwent RT.


Assuntos
Neoplasias Esofágicas , Nomogramas , Pneumonite por Radiação , Humanos , Neoplasias Esofágicas/radioterapia , Pneumonite por Radiação/etiologia , Feminino , Masculino , Estudos Retrospectivos , Pessoa de Meia-Idade , Idoso , Dosagem Radioterapêutica , Prognóstico , Idoso de 80 Anos ou mais , Tomografia Computadorizada por Raios X , Radiômica
4.
J Agric Food Chem ; 2024 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-38913033

RESUMO

Lipase from Rhizopus oryzae (ROL) exhibits remarkable sn-1,3 stereoselectivity and catalytic activity, but its poor thermostability limits its applications in the production of 1,3-dioleoyl-2-palmitoyl glycerol (OPO, a high-quality substitute for human milk fat). In this work, a semirational method was proposed to engineer the thermostability and catalytic activity of 4M (ROL mutant in our previous study). First, a computer-aided design is performed using 4M as a template, and N-glycosylation mutants are then recombinantly expressed and screened in Pichia pastoris, the optimal mutant N227 exhibited a half-life of 298.8 h at 45 °C, which is 7.23-folds longer than that of 4M. Its catalytic activity also reached 1043.80 ± 61.98 U/mg, representing a 29.2% increase compared to 4M (808.02 ± 47.02 U/mg). Molecular dynamics simulations of N227 suggested that the introduction of glycan enhanced the protein rigidity, while the strong hydrogen bonds formed between the glycan and the protein stabilized the lipase structure, thereby improving its thermostability. The acidolysis reaction between oleic acid (OA) and glycerol tripalmitate (PPP) was successfully carried out using immobilized N227, achieving a molar conversion rate of 90.2% for PPP. This engineering strategy guides the modification of lipases, while the glycomutants obtained in this study have potential applications in the biosynthesis of OPO.

5.
Chembiochem ; : e202400285, 2024 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-38752893

RESUMO

ω-Transaminases (ω-TAs) are attractive biocatalysts asymmetrically catalyzing ketones to chiral amines. However, poor non-native catalytic activity and substrate promiscuity severely hamper its wide application in industrial production. Protein engineering efforts have generally focused on reshaping the substrate-binding pockets of ω-TAs. However, hotspots around the substrate tunnel as well as distant sites outside the pockets may also affect its activity. In this study, the ω-TA from Bacillus megaterium (BmeTA) was selected for engineering. The tunnel mutation Y164F synergy with distant mutation A245T which was acquired through a multiple sequence alignment showed improved soluble expression, a 3.7-fold higher specific activity and a 19.9-fold longer half-life at 45℃. Molecule Dynamics simulation explains the mechanism of improved catalytic activity, enhanced thermostability and improved soluble expression of BmeTAY164F/A245T(2M). Finally, the resting cells of 2M were used for biocatalytic processes. 450 mM of S-methoxyisopropylamine (S-MOIPA) was obtained with an ee value of 97.3% and a conversion rate of 90%, laying the foundation for its industrial production. Mutant 2M was also found to be more advantageous in catalyzing the transamination of various ketones. These results demonstrated that sites that are far away from the active center also play an important role in the redesign of ω-TAs.

6.
Int J Biol Macromol ; 269(Pt 2): 132102, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38729465

RESUMO

Optically pure 1,2,3,4-tetrahydroquinolines (THQs) represent a class of important motifs in many natural products and pharmaceutical agents. While recent advances on redox biocatalysis have demonstrated the great potential of amine oxidases, all the transformations focused on 2-substituted THQs. The corresponding biocatalytic method for the preparation of chiral 4-substituted THQs is still challenging due to the poor activity and stereoselectivity of the available enzyme. Herein, we developed a biocatalytic kinetic resolution approach for enantiodivergent synthesis of 4-phenyl- or alkyl-substituted THQs. Through structure-guided protein engineering of cyclohexylamine oxidase derived from Brevibacterium oxidans IH-35 A (CHAO), the variant of CHAO (Y215H/Y214S) displayed improved specific activity toward model substrate 4-phenyl substituted THQ (0.14 U/mg, 13-fold higher than wild-type CHAO) with superior (R)-stereoselectivity (E > 200). Molecular dynamics simulations show that CHAO Y215H/Y214S allows a suitable substrate positioning in the expanded binding pocket to be facilely accessed, enabling enhanced activity and stereoselectivity. Furthermore, a series of 4-alkyl-substituted THQs can be transformed by CHAO Y215H/Y214S, affording R-isomers with good yields (up to 50 %) and excellent enantioselectivity (up to ee > 99 %). Interestingly, the monoamine oxidase from Pseudomonas fluorescens Pf0-1 (PfMAO1) with opposite enantioselectivity was also mined. Together, this system enriches the kinetic resolution methods for the synthesis of chiral THQs.


Assuntos
Quinolinas , Cinética , Estereoisomerismo , Quinolinas/química , Biocatálise , Brevibacterium/enzimologia , Especificidade por Substrato , Simulação de Dinâmica Molecular , Monoaminoxidase/metabolismo , Monoaminoxidase/química
7.
Food Res Int ; 183: 114184, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38760126

RESUMO

The global market for plant-based meat alternatives (PBMAs) is expanding quickly. In this narrative review, analysis of the most recent scientific literature was achieved to understand the nutritional profile, health implications, and the challenges faced by PBMAs. On the positive side, most PBMAs are good sources of dietary fiber, contain phytochemicals, have comparable levels of iron, and are lower in calories, saturated fat, and cholesterol than meat. However, PBMAs frequently contain anti-nutrients, have less protein, iron, and vitamin B12, are lower in protein quality, and also have higher amounts of sodium. Substituting PBMAs for meats may cause iron, vitamin B12, and less likely protein deficiency for these vulnerable population such as women, older adults, and individuals with disorders. PBMAs fall into the category of ultra-processed foods, indicating a need to develop minimally processed, clean-label products. Replacing red meat with healthy plant-based foods is associated with lower risks of cardiovascular diseases, type 2 diabetes, and total mortality. There is a lack of robust, long-term evidence on the role of PBMAs consumption in health. As the nutrient contents of PBMAs can vary, consumers must read nutrition facts labels and ingredient lists to select a product that best fits their nutritional and health objectives.


Assuntos
Dieta Vegetariana , Valor Nutritivo , Humanos , Dieta Saudável , Carne/análise , Substitutos da Carne
8.
Br J Nutr ; : 1-18, 2024 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-38818723

RESUMO

The potential threshold for dietary energy intake (DEI) that might prevent protein-energy wasting (PEW) in chronic kidney disease (CKD) is uncertain. The subjects were non-dialysis CKD patients aged ≥ 14 years who were hospitalized from September 2019 to July 2022. PEW was measured by subjective global assessment (SGA). DEI and dietary protein intake (DPI) were obtained by 3-days diet recalls. Patients were divided into adequate DEI group and inadequate DEI group according to DEI ≥ 30 or < 30 kcal/kg/d. Logistic regression analysis and restricted cubic spline (RCS) were used in this study. We enrolled 409 patients, with 53.8% had hypertension and 18.6% had diabetes. The DEI and DPI was 27.63 ± 5.79 kcal/kg/day and 1.00 (0.90,1.20) g/kg/day, respectively. 69.2% of participants in inadequate DEI group. Malnutrition occurred in 18.6% of patients. Comparing to patients in adequate DEI group, those in inadequate DEI group had significantly lower total lymphocyte count (TLC), serum cholesterol (Chol) and low-density cholesterol (LDL), and a higher prevalence of PEW. For every 1kcal/kg/day increase in DEI, the incidence of PEW was reduced by 12.0% [odds ratio (OR): 0.880, 95% confidence interval (CI): 0.830 to 0.933, P < 0.001]. There was a nonlinear curve relationship between DEI and PEW (overall P < 0.001), and DEI ≥ 27.6 kcal/kg/d may have a preventive effect on PEW in CKD. Low DPI was also significantly associated with malnutrition, but not when DEI was adequate. Decreased energy intake may be a more important factor of PEW in CKD than protein intake.

9.
J Agric Food Chem ; 72(23): 12896-12914, 2024 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-38810024

RESUMO

Angiotensin-converting enzyme 2 (ACE2) is a key enzyme in the renin-angiotensin system (RAS), also serving as an amino acid transporter and a receptor for certain coronaviruses. Its primary role is to protect the cardiovascular system via the ACE2/Ang (1-7)/MasR cascade. Given the critical roles of ACE2 in regulating numerous physiological functions, molecules that can upregulate or activate ACE2 show vast therapeutic value. There are only a few ACE2 activators that have been reported, a wide range of molecules, including food-derived compounds, have been reported as ACE2 up-regulators. Effective doses of bioactive peptides range from 10 to 50 mg/kg body weight (BW)/day when orally administered for 1 to 7 weeks. Protein hydrolysates require higher doses at 1000 mg/kg BW/day for 20 days. Phytochemicals and vitamins are effective at doses typically ranging from 10 to 200 mg/kg BW/day for 3 days to 6 months, while Traditional Chinese Medicine requires doses of 1.25 to 12.96 g/kg BW/day for 4 to 8 weeks. ACE2 activation is linked to its hinge-bending region, while upregulation involves various signaling pathways, transcription factors, and epigenetic modulators. Future studies are expected to explore novel roles of ACE2 activators or up-regulators in disease treatments and translate the discovery to bedside applications.


Assuntos
Enzima de Conversão de Angiotensina 2 , Regulação para Cima , Enzima de Conversão de Angiotensina 2/metabolismo , Enzima de Conversão de Angiotensina 2/genética , Humanos , Animais , Regulação para Cima/efeitos dos fármacos , Sistema Renina-Angiotensina/efeitos dos fármacos , Peptidil Dipeptidase A/metabolismo , Peptidil Dipeptidase A/genética , Compostos Fitoquímicos/metabolismo , Compostos Fitoquímicos/química , Compostos Fitoquímicos/farmacologia
10.
Appl Environ Microbiol ; 90(6): e0000124, 2024 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-38771056

RESUMO

Global change factors are known to strongly affect soil microbial community function and composition. However, as of yet, the effects of warming and increased anthropogenic nitrogen deposition on soil microbial network complexity and stability are still unclear. Here, we examined the effects of experimental warming (3°C above ambient soil temperature) and nitrogen addition (5 g N m-2 year-1) on the complexity and stability of the soil microbial network in a subtropical primary forest. Compared to the control, warming increased |negative cohesion|:positive cohesion by 7% and decreased network vulnerability by 5%; nitrogen addition decreased |negative cohesion|:positive cohesion by 10% and increased network vulnerability by 11%. Warming and decreased soil moisture acted as strong filtering factors that led to higher bacterial network stability. Nitrogen addition reduced bacterial network stability by inhibiting soil respiration and increasing resource availability. Neither warming nor nitrogen addition changed fungal network complexity and stability. These findings suggest that the fungal community is more tolerant than the bacterial community to climate warming and nitrogen addition. The link between bacterial network stability and microbial community functional potential was significantly impacted by nitrogen addition and warming, while the response of soil microbial network stability to climate warming and nitrogen deposition may be independent of its complexity. Our findings demonstrate that changes in microbial network structure are crucial to ecosystem management and to predict the ecological consequences of global change in the future. IMPORTANCE: Soil microbes play a very important role in maintaining the function and health of forest ecosystems. Unfortunately, global change factors are profoundly affecting soil microbial structure and function. In this study, we found that climate warming promoted bacterial network stability and nitrogen deposition decreased bacterial network stability. Changes in bacterial network stability had strong effects on bacterial community functional potentials linked to metabolism, nitrogen cycling, and carbon cycling, which would change the biogeochemical cycle in primary forests.


Assuntos
Bactérias , Florestas , Fungos , Microbiota , Nitrogênio , Microbiologia do Solo , Nitrogênio/metabolismo , Bactérias/metabolismo , Fungos/metabolismo , Solo/química , Aquecimento Global , Mudança Climática
11.
J Agric Food Chem ; 72(15): 8606-8617, 2024 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-38581395

RESUMO

Peptide IRW is the first food-derived angiotensin-converting enzyme 2 (ACE2) upregulator. This study aimed to investigate the pharmacokinetic characteristics of IRW and identify the metabolites contributing to its antihypertensive activity in spontaneously hypertensive rats (SHRs). Rats were administered 100 mg of IRW/kg of the body weight via an intragastric or intravenous route. The bioavailability (F %) was determined to be 11.7%, and the half-lives were 7.9 ± 0.5 and 28.5 ± 6.8 min for gavage and injection, respectively. Interestingly, significant blood pressure reduction was not observed until 1.5 h post oral administration, or 2 h post injection, indicating that the peptide's metabolites are likely responsible for the blood pressure-lowering activity. Time-course metabolomics revealed a significant increase in the level of kynurenine, a tryptophan metabolite, in blood after IRW administration. Kynurenine increased the level of ACE2 in cells. Oral administration of tryptophan (W), but not dipeptide IR, lowered the blood pressure and upregulated aortic ACE2 in SHRs. Our study supports the key role of tryptophan and its metabolite, kynurenine, in IRW's blood pressure-lowering effects.


Assuntos
Enzima de Conversão de Angiotensina 2 , Hipertensão , Ratos , Animais , Ratos Endogâmicos SHR , Enzima de Conversão de Angiotensina 2/metabolismo , Disponibilidade Biológica , Cinurenina/metabolismo , Cinurenina/farmacologia , Triptofano/metabolismo , Peptídeos/metabolismo , Anti-Hipertensivos/farmacologia , Pressão Sanguínea , Hipertensão/metabolismo , Peptidil Dipeptidase A/metabolismo
12.
Nat Chem ; 2024 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-38632367

RESUMO

Despite their intriguing photophysical and photochemical activities, naturally occurring photoenzymes have not yet been repurposed for new-to-nature activities. Here we engineered fatty acid photodecarboxylases to catalyse unnatural photoredox radical C-C bond formation by leveraging the strongly oxidizing excited-state flavoquinone cofactor. Through genome mining, rational engineering and directed evolution, we developed a panel of radical photocyclases to facilitate decarboxylative radical cyclization with excellent chemo-, enantio- and diastereoselectivities. Our high-throughput experimental workflow allowed for the directed evolution of fatty acid photodecarboxylases. An orthogonal set of radical photocyclases was engineered to access all four possible stereoisomers of the stereochemical dyad, affording fully diastereo- and enantiodivergent biotransformations in asymmetric radical biocatalysis. Molecular dynamics simulations show that our evolved radical photocyclases allow near-attack conformations to be easily accessed, enabling chemoselective radical cyclization. The development of stereoselective radical photocyclases provides unnatural C-C-bond-forming activities in natural photoenzyme families, which can be used to tame the stereochemistry of free-radical-mediated reactions.

13.
Int J Biol Macromol ; 267(Pt 2): 131415, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38582485

RESUMO

The complete enzyme catalytic cycle includes substrate binding, chemical reaction and product release, in which different dynamic conformations are adopted. Due to the complex relationship among enzyme activity, stability and dynamics, the directed evolution of enzymes for improved activity or stability commonly leads to a trade-off in stability or activity. It hence remains a challenge to engineer an enzyme to have both enhanced activity and stability. Here, we have attempted to reconstruct the dynamics correlation network involved with active center to improve both activity and stability of a 2,3-butanediol dehydrogenase (2,3-BDH) by introducing inter-chain disulfide bonds. A computational strategy was first applied to evaluate the effect of introducing inter-chain disulfide bond on activity and stability of three 2,3-BDHs, and the N258C mutation of 2,3-BDH from Corynebacterium glutamicum (CgBDH) was proved to be effective in improving both activity and stability. In the results, CgBDH-N258C showed a different unfolding curve from the wild type, with two melting temperatures (Tm) of 68.3 °C and 50.8 °C, 19.7 °C and 2 °C higher than 48.6 °C of the wild type. Its half-life was also improved by 14.8-fold compared to the wild type. Catalytic efficiency (kcat/Km) of the mutant was increased by 7.9-fold toward native substrate diacetyl and 8.8-fold toward non-native substrate 2,5-hexanedione compared to the wild type. Molecular dynamics simulations revealed that an interaction network formed by Cys258, Arg162, Ala144 and the catalytic residues was reconstructed in the mutant and the dynamics change caused by the disulfide bond could be propagated through the interactions network. This improved the enzyme stability and activity by decreasing the flexibility and locking more "reactive" pose, respectively. Further construction of mutations including A144G showing a 44-fold improvement in catalytic efficiency toward meso-2,3-BD confirmed the role of modifying dynamics correlation network in tunning enzyme activity and selectivity. This study provided important insights into the relationship among dynamics, enzyme catalysis and stability, and will be useful in the designing new enzymes with co-evolution of stability, activity and selectivity.


Assuntos
Oxirredutases do Álcool , Corynebacterium glutamicum , Dissulfetos , Estabilidade Enzimática , Simulação de Dinâmica Molecular , Oxirredutases do Álcool/química , Oxirredutases do Álcool/genética , Oxirredutases do Álcool/metabolismo , Dissulfetos/química , Corynebacterium glutamicum/enzimologia , Corynebacterium glutamicum/genética , Mutação , Domínio Catalítico , Cinética , Conformação Proteica , Engenharia de Proteínas/métodos
14.
Bioresour Bioprocess ; 11(1): 26, 2024 Feb 29.
Artigo em Inglês | MEDLINE | ID: mdl-38647789

RESUMO

The use of enzymes to catalyze Henry reaction has advantages of mild reaction conditions and low contamination, but low enzyme activity of promiscuous catalysis limits its application. Here, rational design was first performed to identify the key amino acid residues in Henry reaction catalyzed by Lactococcal multidrug resistance Regulator (LmrR). Further, non-canonical amino acids were introduced into LmrR, successfully obtaining variants that enhanced the catalytic activity of LmrR. The best variant, V15CNF, showed a 184% increase in enzyme activity compared to the wild type, and was 1.92 times more effective than the optimal natural amino acid variant, V15F. Additionally, this variant had a broad substrate spectrum, capable of catalyzing reactions between various aromatic aldehydes and nitromethane, with product yielded ranging from 55 to 99%. This study improved enzymatic catalytic activity by enhancing affinity between the enzyme and substrates, while breaking limited types of natural amino acid residues by introducing non-canonical amino acids into the enzyme, providing strategies for molecular modifications.

15.
Nat Struct Mol Biol ; 2024 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-38658622

RESUMO

The PIWI-interacting RNA (piRNA) pathway is an adaptive defense system wherein piRNAs guide PIWI family Argonaute proteins to recognize and silence ever-evolving selfish genetic elements and ensure genome integrity. Driven by this intensive host-pathogen arms race, the piRNA pathway and its targeted transposons have coevolved rapidly in a species-specific manner, but how the piRNA pathway adapts specifically to target silencing in mammals remains elusive. Here, we show that mouse MILI and human HILI piRNA-induced silencing complexes (piRISCs) bind and cleave targets more efficiently than their invertebrate counterparts from the sponge Ephydatia fluviatilis. The inherent functional differences comport with structural features identified by cryo-EM studies of piRISCs. In the absence of target, MILI and HILI piRISCs adopt a wider nucleic-acid-binding channel and display an extended prearranged piRNA seed as compared with EfPiwi piRISC, consistent with their ability to capture targets more efficiently than EfPiwi piRISC. In the presence of target, the seed gate-which enforces seed-target fidelity in microRNA RISC-adopts a relaxed state in mammalian piRISC, revealing how MILI and HILI tolerate seed-target mismatches to broaden the target spectrum. A vertebrate-specific lysine distorts the piRNA seed, shifting the trajectory of the piRNA-target duplex out of the central cleft and toward the PAZ lobe. Functional analyses reveal that this lysine promotes target binding and cleavage. Our study therefore provides a molecular basis for the piRNA targeting mechanism in mice and humans, and suggests that mammalian piRNA machinery can achieve broad target silencing using a limited supply of piRNA species.

16.
Food Chem X ; 22: 101352, 2024 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-38601950

RESUMO

α-Amylase, essential for carbohydrate digestion, relies on calcium (Ca) for its structural integrity and enzymatic activity. This study explored the inhibitory effect of salmon bone peptides on α-amylase activity through their interaction with the enzyme's Ca-binding sites. Among the various salmon bone hydrolysates, salmon bone trypsin hydrolysate (SBTH) exhibited the highest α-amylase inhibition. The peptide IEELEEELEAER (PIE), with a sequence of Ile-Glu-Glu-Leu-Glu-Glu-Glu-Glu-Leu-Glu-Ala-Glu-Arg from SBTH, was found to specifically target the Ca-binding sites in α-amylase, interacting with key residues such as Asp206, Trp203, His201, etc. Additionally, cellular experiments using 3 T3-L1 preadipocytes indicated PIE's capability to suppress adipocyte differentiation, and decreases in intracellular triglycerides, total cholesterol, and lipid accumulation. In vivo studies also showed a significant reduction in weight gain in the group treated with PIE(6.61%)compared with the control group (33.65%). These findings suggest PIE is an effective α-amylase inhibitor, showing promise for obesity treatment.

17.
Acta Trop ; 255: 107234, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38688444

RESUMO

Aedes albopictus (Diptera: Culicidae) plays a crucial role as a vector for mosquito-borne diseases like dengue and zika. Given the limited availability of effective vaccines, the prevention of Aedes-borne diseases mainly relies on extensive efforts in vector surveillance and control. In multiple mosquito control methods, the identification and elimination of potential breeding sites (PBS) for Aedes are recognized as effective methods for population control. Previous studies utilizing unmanned aerial vehicles (UAVs) and deep learning to identify PBS have primarily focused on large, regularly-shaped containers. However, there has been a small amount of empirical research into their practical application in the field. We have thus constructed a PBS dataset specifically tailored for Ae. albopictus, including items such as buckets, bowls, bins, aquatic plants, jars, lids, pots, boxes, and sinks that were common in the Yangtze River Basin in China. Then, a YOLO v7 model for identifying these PBS was developed. Finally, we recognized and labeled the area with the highest PBS density, as well as the subarea with the most urgent need for source reduction in the empirical region, by calculating the kernel density value. Based on the above research, we proposed a UAV-AI-based methodological framework to locate the spatial distribution of PBS, and conducted empirical research on Jinhulu New Village, a typical model community. The results revealed that the YOLO v7 model achieved an excellent result on the F1 score and mAP(both above 0.99), with 97% of PBS correctly located. The predicted distribution of different PBS categories in each subarea was completely consistent with true distribution; the five houses with the most PBS were correctly located. The results of the kernel density map indicate the subarea 4 with the highest density of PBS, where PBS needs to be removed or destroyed with immediate effect. These results demonstrate the reliability of the prediction results and the feasibility of the UAV-AI-based methodological framework. It can minimize repetitive labor, enhance efficiency, and provide guidance for the removal and destruction of PBS. The research can shed light on the investigation of mosquito PBS investigation both methodologically and practically.


Assuntos
Aedes , Aprendizado Profundo , Controle de Mosquitos , Mosquitos Vetores , Animais , Aedes/fisiologia , Aedes/crescimento & desenvolvimento , Mosquitos Vetores/fisiologia , China , Controle de Mosquitos/métodos , Tecnologia de Sensoriamento Remoto
18.
ACS Nano ; 18(12): 9137-9149, 2024 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-38470845

RESUMO

Point-of-care monitoring of small molecules in biofluids is crucial for clinical diagnosis and treatment. However, the inherent low degree of recognition of small molecules and the complex composition of biofluids present significant obstacles for current detection technologies. Although nanopore sensing excels in the analysis of small molecules, the direct detection of small molecules in complex biofluids remains a challenge. In this study, we present a method for sensing the small molecule drug gentamicin in whole blood based on the mechanosensitive channel of small conductance in Pseudomonas aeruginosa (PaMscS) nanopore. PaMscS can directly detect gentamicin and distinguish its main components with only a monomethyl difference. The 'molecular sieve' structure of PaMscS enables the direct measurement of gentamicin in human whole blood within 10 min. Furthermore, a continuous monitoring device constructed based on PaMscS achieved continuous monitoring of gentamicin in live rats for approximately 2.5 h without blood consumption, while the drug components can be analyzed in situ. This approach enables rapid and convenient drug monitoring with single-molecule level resolution, which can significantly lower the threshold for drug concentration monitoring and promote more efficient drug use. Moreover, this work also lays the foundation for the future development of continuous monitoring technology with single-molecule level resolution in the living body.


Assuntos
Antibacterianos , Nanoporos , Humanos , Ratos , Animais , Antibacterianos/farmacologia , Gentamicinas , Nanotecnologia , Pseudomonas aeruginosa
19.
Cardiovasc Res ; 120(7): 796-810, 2024 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-38498586

RESUMO

AIMS: Long non-coding RNA (LncRNA) small nucleolar RNA host gene 18 (SNHG18) has been widely implicated in cancers. However, little is known about its functional involvement in vascular diseases. Herein, we attempted to explore a role for SNHG18 in modulating vascular smooth muscle cell (VSMC) contractile phenotype and injury-induced neointima formation. METHODS AND RESULTS: Analysis of single-cell RNA sequencing and transcriptomic datasets showed decreased levels of SNHG18 in injured and atherosclerotic murine and human arteries, which is positively associated with VSMC contractile genes. SNHG18 was upregulated in VSMCs by TGFß1 through transcription factors Sp1 and SMAD3. SNHG18 gene gain/loss-of-function studies revealed that VSMC contractile phenotype was positively regulated by SNHG18. Mechanistic studies showed that SNHG18 promotes a contractile VSMC phenotype by up-regulating miR-22-3p. SNHG18 up-regulates miR-22 biogenesis and miR-22-3p production by competitive binding with the A-to-I RNA editing enzyme, adenosine deaminase acting on RNA-2 (ADAR2). Surprisingly, we observed that ADAR2 inhibited miR-22 biogenesis not through increasing A-to-I editing within primary miR-22, but by interfering with the binding of microprocessor complex subunit DGCR8 to primary miR-22. Importantly, perivascular SNHG18 overexpression in the injured vessels dramatically up-regulated the expression levels of miR-22-3p and VSMC contractile genes, and prevented injury-induced neointimal hyperplasia. Such modulatory effects were reverted by miR-22-3p inhibition in the injured arteries. Finally, we observed a similar regulator role for SNHG18 in human VSMCs and a decreased expression level of both SNHG18 and miR-22-3p in diseased human arteries; and we found that the expression level of SNHG18 was positively associated with that of miR-22-3p in both healthy and diseased human arteries. CONCLUSION: We demonstrate that SNHG18 is a novel regulator in governing VSMC contractile phenotype and preventing injury-induced neointimal hyperplasia. Our findings have important implications for therapeutic targeting snhg18/miR-22-3p signalling in vascular diseases.


Assuntos
Lesões das Artérias Carótidas , Modelos Animais de Doenças , Hiperplasia , Camundongos Endogâmicos C57BL , MicroRNAs , Músculo Liso Vascular , Miócitos de Músculo Liso , Neointima , Fenótipo , RNA Longo não Codificante , Músculo Liso Vascular/patologia , Músculo Liso Vascular/metabolismo , Miócitos de Músculo Liso/metabolismo , Miócitos de Músculo Liso/patologia , Humanos , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , MicroRNAs/metabolismo , MicroRNAs/genética , Animais , Lesões das Artérias Carótidas/patologia , Lesões das Artérias Carótidas/genética , Lesões das Artérias Carótidas/metabolismo , Células Cultivadas , Masculino , Transdução de Sinais , Proteínas de Ligação a RNA/metabolismo , Proteínas de Ligação a RNA/genética , Regulação da Expressão Gênica , Camundongos , Camundongos Knockout para ApoE
20.
Front Pediatr ; 12: 1332989, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38523842

RESUMO

Introduction: To investigate the epidemiological features and prevalence of cruciate ligament injuries (CLI) in children and adolescents, and to examine the potential risk factors associated with concomitant meniscal tear (MT) among this population. Methods: The demographic data and injury details of children and adolescents with CLI from Southeast China were analyzed to describe their distribution characteristics, alongside an analysis of the prevalence of MTs, the most frequent complication. In addition, binary logistic analysis was employed to ascertain the risk factors linked to MT in individuals suffering from CLI. Results: A total of 203 patients with CLI (n = 206) met the inclusion criteria, with a male-to-female ratio of 2.3:1. Notably, a higher proportion of females were aged ≤16 years old compared to males, who predominated in patients aged >16 years (P = 0.001). Among children and adolescents, anterior cruciate ligament (ACL) injuries were the primary type of CLI, accounting for 88.18% (179/203) of all cases. The majority of cases (132/203, 65.02%) were sustained during sports activities, and sprains were the predominant mechanism of injury (176/203, 86.7%). Additionally, the most common associated injury was an MT (157/203, 77.34%). The posterior horn is the most frequently affected site for both medial MT (62.93% out of 73 cases) and lateral MT (70.19% out of 73 cases). Moreover, vertical tears constituted the majority of medial MTs (59.48% out of 116 cases). Furthermore, patients with a higher BMI faced an increased risk of associated MT in comparison to non-overweight patients (88% vs. 73.86%; P = 0.038). Each increase in BMI unit was linked with a 14% higher probability of associated MT occurrence in children and adolescents with CLI (OR = 1.140; P = 0.036). Discussion: ACL injuries are a common form of knee ligament injury among children and adolescents, especially those over the age of 16, and are often the result of a sprain. Meniscal posterior horn injury is the most commonly associated injury of youth with CLI. Additionally, overweight or obese people with CLI are at a greater risk of developing MT.

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