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1.
J Neuroinflammation ; 21(1): 169, 2024 Jul 03.
Article in English | MEDLINE | ID: mdl-38961424

ABSTRACT

BACKGROUND: Understanding the mechanism behind sepsis-associated encephalopathy (SAE) remains a formidable task. This study endeavors to shed light on the complex cellular and molecular alterations that occur in the brains of a mouse model with SAE, ultimately unraveling the underlying mechanisms of this condition. METHODS: We established a murine model using intraperitoneal injection of lipopolysaccharide (LPS) in wild type and Anxa1-/- mice and collected brain tissues for analysis at 0-hour, 12-hour, 24-hour, and 72-hour post-injection. Utilizing advanced techniques such as single-nucleus RNA sequencing (snRNA-seq) and Stereo-seq, we conducted a comprehensive characterization of the cellular responses and molecular patterns within the brain. RESULTS: Our study uncovered notable temporal differences in the response to LPS challenge between Anxa1-/- (annexin A1 knockout) and wild type mice, specifically at the 12-hour and 24-hour time points following injection. We observed a significant increase in the proportion of Astro-2 and Micro-2 cells in these mice. These cells exhibited a colocalization pattern with the vascular subtype Vas-1, forming a distinct region known as V1A2M2, where Astro-2 and Micro-2 cells surrounded Vas-1. Moreover, through further analysis, we discovered significant upregulation of ligands and receptors such as Timp1-Cd63, Timp1-Itgb1, Timp1-Lrp1, as well as Ccl2-Ackr1 and Cxcl2-Ackr1 within this region. In addition, we observed a notable increase in the expression of Cd14-Itgb1, Cd14-Tlr2, and Cd14-C3ar1 in regions enriched with Micro-2 cells. Additionally, Cxcl10-Sdc4 showed broad upregulation in brain regions containing both Micro-2 and Astro-2 cells. Notably, upon LPS challenge, there was an observed increase in Anxa1 expression in the mouse brain. Furthermore, our study revealed a noteworthy increase in mortality rates following Anxa1 knockdown. However, we did not observe substantial differences in the types, numbers, or distribution of other brain cells between Anxa1-/- and wildtype mice over time. Nevertheless, when comparing the 24-hour post LPS injection time point, we observed a significant decrease in the proportion and distribution of Micro-2 and Astro-2 cells in the vicinity of blood vessels in Anxa1-/- mice. Additionally, we noted reduced expression levels of several ligand-receptor pairs including Cd14-Tlr2, Cd14-C3ar1, Cd14-Itgb1, Cxcl10-Sdc4, Ccl2-Ackr1, and Cxcl2-Ackr1. CONCLUSIONS: By combining snRNA-seq and Stereo-seq techniques, our study successfully identified a distinctive cellular colocalization, referred to as a special pathological niche, comprising Astro-2, Micro-2, and Vas-1 cells. Furthermore, we observed an upregulation of ligand-receptor pairs within this niche. These findings suggest a potential association between this cellular arrangement and the underlying mechanisms contributing to SAE or the increased mortality observed in Anxa1 knockdown mice.


Subject(s)
Astrocytes , Brain , Disease Models, Animal , Lipopolysaccharides , Mice, Knockout , Microglia , Sepsis-Associated Encephalopathy , Animals , Mice , Lipopolysaccharides/toxicity , Sepsis-Associated Encephalopathy/pathology , Sepsis-Associated Encephalopathy/genetics , Sepsis-Associated Encephalopathy/metabolism , Microglia/metabolism , Microglia/pathology , Brain/pathology , Brain/metabolism , Astrocytes/metabolism , Astrocytes/pathology , Sequence Analysis, RNA/methods , Mice, Inbred C57BL , Transcriptome , Male
2.
Biomed Pharmacother ; 177: 117093, 2024 Jul 05.
Article in English | MEDLINE | ID: mdl-38971012

ABSTRACT

Protein phosphorylation is an important link in a variety of signaling pathways, and most of the important life processes in cells involve protein phosphorylation. Based on the amino acid residues of phosphorylated proteins, protein kinases can be categorized into the following families: serine/threonine protein kinases, tyrosine-specific protein kinases, histidine-specific protein kinases, tryptophan kinases, and aspartate/glutamyl protein kinases. Of all the protein kinases, most are serine/threonine kinases, where serine/threonine protein kinases are protein kinases that catalyze the phosphorylation of serine or threonine residues on target proteins using ATP as a phosphate donor. The current socially accepted classification of serine/threonine kinases is to divide them into seven major groups: protein kinase A, G, C (AGC), CMGC, Calmodulin-dependent protein kinase (CAMK), Casein kinase (CK1), STE, Tyrosine kinase (TKL) and others. After decades of research, a preliminary understanding of the specific classification and respective functions of serine/threonine kinases has entered a new period of exploration. In this paper, we review the literature of the previous years and introduce the specific signaling pathways and related therapeutic modalities played by each of the small protein kinases in the serine/threonine protein kinase family, respectively, in some common cardiovascular system diseases such as heart failure, myocardial infarction, ischemia-reperfusion injury, and diabetic cardiomyopathy. To a certain extent, the current research results, including molecular mechanisms and therapeutic methods, are fully summarized and a systematic report is made for the prevention and treatment of cardiovascular diseases in the future.

3.
Heliyon ; 10(12): e32609, 2024 Jun 30.
Article in English | MEDLINE | ID: mdl-38975192

ABSTRACT

Closed-loop neuromodulation with intelligence methods has shown great potentials in providing novel neuro-technology for treating neurological and psychiatric diseases. Development of brain-machine interactive neuromodulation strategies could lead to breakthroughs in precision and personalized electronic medicine. The neuromodulation research tool integrating artificial intelligent computing and performing neural sensing and stimulation in real-time could accelerate the development of closed-loop neuromodulation strategies and translational research into clinical application. In this study, we developed a brain-machine interactive neuromodulation research tool (BMINT), which has capabilities of neurophysiological signals sensing, computing with mainstream machine learning algorithms and delivering electrical stimulation pulse by pulse in real-time. The BMINT research tool achieved system time delay under 3 ms, and computing capabilities in feasible computation cost, efficient deployment of machine learning algorithms and acceleration process. Intelligent computing framework embedded in the BMINT enable real-time closed-loop neuromodulation developed with mainstream AI ecosystem resources. The BMINT could provide timely contribution to accelerate the translational research of intelligent neuromodulation by integrating neural sensing, edge AI computing and stimulation with AI ecosystems.

4.
Toxics ; 12(6)2024 May 23.
Article in English | MEDLINE | ID: mdl-38922061

ABSTRACT

Ischemic stroke (IS), chronic obstructive pulmonary disease (COPD) and diabetes mellitus (DM) account for a large burden of premature deaths. However, few studies have investigated the associations between fine particular matter (PM2.5) components and mortality of IS, COPD and DM. We aimed to examine these associations in Beijing, China. Data on daily mortality, air pollutants and meteorological factors from 2008 to 2011 in Beijing were collected. Daily concentrations of five PM2.5 components, namely, sulfate ion (SO42-), ammonium ion (NH4+), nitrate ion (NO3-), organic matter (OM) and black carbon (BC), were obtained from the Tracking Air Pollution (TAP) database in China. The association between PM2.5 components and daily deaths was explored using a quasi-Poisson regression with the distributed lag nonlinear model (DLNM). The average daily concentrations of SO42-, NH4+, NO3-, OM and BC were 11.24, 8.37, 12.00, 17.34 and 3.32 µg/m3, respectively. After adjusting for temperature, relative humidity, pressure, particulate matter less than 10 µm in aerodynamic diameter (PM10), nitrogen dioxide (NO2) and sulfur dioxide (SO2), an IQR increase in OM at lag day 2 and lag day 6 was associated with an increased DM mortality risk (RR 1.038; 95% CI: 1.005-1.071) and COPD mortality risk (RR 1.013; 95% CI: 1.001-1.026). An IQR increase in BC at lag day 0 and lag day 6 was associated with increased COPD mortality risk (RR 1.228; 95% CI: 1.017-1.48, RR 1.059; 95% CI: 1.001-1.121). Cumulative exposure to SO42- and NH4+ was associated with an increased mortality risk for IS, with the highest effect found for lag of 0-7 days (RR 1.085; 95% CI: 1.010-1.167, RR 1.083; 95% CI: 1.003-1.169). These effects varied by sex and age group. This study demonstrated associations of short-term exposure to PM2.5 components with increased risk of IS, COPD and DM mortality in the general population. Our study also highlighted susceptible subgroups.

5.
New Phytol ; 243(3): 1154-1171, 2024 Aug.
Article in English | MEDLINE | ID: mdl-38822646

ABSTRACT

Cross-kingdom RNA interference (RNAi) is a crucial mechanism in host-pathogen interactions, with RNA-dependent RNA polymerase (RdRP) playing a vital role in signal amplification during RNAi. However, the role of pathogenic fungal RdRP in siRNAs generation and the regulation of plant-pathogen interactions remains elusive. Using deep sequencing, molecular, genetic, and biochemical approaches, this study revealed that VmRDR2 of Valsa mali regulates VmR2-siR1 to suppress the disease resistance-related gene MdLRP14 in apple. Both VmRDR1 and VmRDR2 are essential for the pathogenicity of V. mali in apple, with VmRDR2 mediating the generation of endogenous siRNAs, including an infection-related siRNA, VmR2-siR1. This siRNA specifically degrades the apple intracellular LRR-RI protein gene MdLRP14 in a sequence-specific manner, and overexpression of MdLRP14 enhances apple resistance against V. mali, which can be suppressed by VmR2-siR1. Conversely, MdLRP14 knockdown reduces resistance. In summary, this study demonstrates that VmRDR2 contributes to the generation of VmR2-siR1, which silences the host's intracellular LRR protein gene, thereby inhibiting host resistance. These findings offer novel insights into the fungi-mediated pathogenicity mechanism through RNAi.


Subject(s)
Disease Resistance , Malus , Plant Diseases , Plant Proteins , RNA Interference , Malus/genetics , Malus/microbiology , Disease Resistance/genetics , Plant Diseases/microbiology , Plant Diseases/genetics , Plant Proteins/genetics , Plant Proteins/metabolism , Gene Expression Regulation, Plant , Fungal Proteins/metabolism , Fungal Proteins/genetics , RNA, Small Interfering/genetics , RNA, Small Interfering/metabolism , Genes, Plant
6.
STAR Protoc ; 5(2): 103124, 2024 Jun 21.
Article in English | MEDLINE | ID: mdl-38870017

ABSTRACT

Global warming will change the photosynthesis and transpiration of plants greatly and ultimately affect water use efficiency (WUE). Here, we present a protocol to investigate the response of maize WUE to the coupling effect of CO2 and temperature at ear stage using a specialized designed gradient. We describe steps for plant culture, parameter measurements, model fitting, and statistical analysis. This protocol holds potential for studying the response of WUE and CO2 adaptation across various plant species. For complete details on the use and execution of this protocol, please refer to Sun et al.1.


Subject(s)
Carbon Dioxide , Photosynthesis , Temperature , Zea mays , Zea mays/physiology , Carbon Dioxide/metabolism , Photosynthesis/physiology , Water/metabolism , Plant Transpiration/physiology
7.
Clin Dermatol ; 2024 Jun 15.
Article in English | MEDLINE | ID: mdl-38885851

ABSTRACT

Doxxing, a type of cyberbullying, occurs when an individual's personal information is shared without consent and with malintent. Doxxing can be seen as a form of vigilantism, a way to hold others accountable for their actions or opinions; however, this form of justice can have catastrophic impacts on the victim, especially physicians. Since the COVID-19 pandemic, where physicians and healthcare providers strongly led public health advocacy efforts on social media, the frequency of doxxing and cyberbullying has increased. Diversity, Equity, and Inclusion (DEI) initiatives have also recently sparked controversy in dermatology and medicine, where advocates for DEI and those opposed to DEI initiatives have also been doxxed. This behavior is incredibly taxing on an individual's mental health, with substantial negative implications on a person's social, personal, and professional life. We discuss the ethical considerations of doxxing and avenues for better protecting physicians.

8.
Pediatr Dermatol ; 2024 Jun 17.
Article in English | MEDLINE | ID: mdl-38887825

ABSTRACT

A current shortage of pediatric dermatologists limits access to dermatologic care among the pediatric population, yet comprehensive and updated data are lacking regarding access among the pediatric Medicaid population. This cross-sectional study characterized Medicaid acceptance among actively practicing board-certified pediatric dermatologists in the United States and revealed that of the 352 physicians compiled, 275 (78.1%) accept Medicaid. Significant differences in Medicaid acceptance status were observed based on practice type, region of practice, practice county median household income, and density of pediatric dermatologists. While the majority of practicing board-certified pediatric dermatologists accept Medicaid, our findings suggest that differences in access to Medicaid-accepting pediatric dermatologists exist based on practice type, geographic location, and density of pediatric dermatologists per county.

9.
Molecules ; 29(11)2024 Jun 05.
Article in English | MEDLINE | ID: mdl-38893544

ABSTRACT

The structural, electronic, magnetic, and optical properties of Co-doped 10-20-atom silver clusters are investigated by GGA/PBE via the density functional theory. The Ag-Co clusters form core-shell structures with a Co atom in the center. Co atom doping modulates electronic properties like energy gap, molecular softness, global hardness, electronegativity, and electrophilicity index. For the optical spectra of the Ag-Co clusters, the energy of their spectra overall exhibits little change with increasing numbers of atoms; the strongest peaks are roughly distributed at 3.5 eV, and the intensity of their spectra overall is strengthened. Raman and vibrational spectra reflect structural changes with Co atom addition. The addition of the Co atom alters magnetic moments of specific Ag-Co clusters, while others remain unchanged.

10.
Dermatol Surg ; 2024 Jun 05.
Article in English | MEDLINE | ID: mdl-38837756

ABSTRACT

BACKGROUND: Dermatologists are trained in diagnostic and therapeutic procedures for cutaneous lesions, yet comparative trends for basic dermatologic procedures across dermatology providers are lacking at the national level. OBJECTIVE: To trend common dermatologic procedures among general dermatologists, Mohs surgeons, primary care providers or primary care physicians (PCPs), and nonphysician clinicians (NPCs). METHODS: Longitudinal analysis of 2016 to 2021 Medicare Public Use Files. RESULTS: Aggregate dermatologic procedural volume decreased 3.0%. Procedural volume declined among general dermatologists (-11.7%), Mohs surgeons (-16.7%), and PCPs (-41.7%) but increased among NPCs (+57.5%). The proportion of procedures by general dermatologists decreased substantially for premalignant destructions (-6.2%), skin biopsies and shave removals (-4.7%), and malignant excisions (-4.1%) and more notably in counties that were nonmetro (-7.1%), low in income (-6.1%), and with <4.0 dermatologists per 100,000 population (-7.0%). CONCLUSION: Aggregate procedural volume decreased across the study period with general dermatologists, Mohs surgeons, and PCPs performing a progressively smaller proportion. The increase in procedures by NPCs may help to address demand but underscores the value of formalized procedural training. The procedural decline by general dermatologists in rural and low-income counties and those with baseline dermatologist shortages may exacerbate existing unmet need. Primary limitation included lack of commercial data.

11.
J Am Chem Soc ; 146(23): 15887-15896, 2024 Jun 12.
Article in English | MEDLINE | ID: mdl-38825776

ABSTRACT

Oxide thin films grown on metal surfaces have wide applications in catalysis and beyond owing to their unique surface structures compared to their bulk counterparts. Despite extensive studies, the atomic structures of copper surface oxides on Cu(111), commonly referred to as "44" and "29", have remained elusive. In this work, we demonstrated an approach for the structural determination of oxide surfaces using element-specific scanning tunneling microscopy (STM) imaging enhanced by functionalized tips. This approach enabled us to resolve the atomic structures of "44" and "29" surface oxides, which were further corroborated by noncontact atomic force microscopy (nc-AFM) measurements and Monte Carlo (MC) simulations. The stoichiometry of the "44" and "29" frameworks was identified as Cu23O16 and Cu16O11, respectively. Contrary to the conventional hypothesis, we observed ordered Cu vacancies within the "44" structure manifesting as peanut-shaped cavities in the hexagonal lattice. Similarly, a combination of Cu and O vacancies within the "29" structure leads to bean-shaped cavities within the pentagonal lattice. Our study has thus resolved the decades-long controversy on the atomic structures of "44" and "29" surface oxides, advancing our understanding of copper oxidation processes and introducing a robust framework for the analysis of complex oxide surfaces.

12.
Quant Imaging Med Surg ; 14(6): 3923-3938, 2024 Jun 01.
Article in English | MEDLINE | ID: mdl-38846315

ABSTRACT

Background: Complex degenerative cervical spondylotic myelopathy (DCM) is characterized by a variety of complex imaging features. The surgical method for DCM remains controversial. This study aimed to examine the correlation between the imaging characteristics of DCM with varying degrees of complexity and the surgical approach and clinical outcome. Methods: A retrospective cohort study involving retrospective data collection was performed. A total of 139 patients with DCM who underwent surgery between January 2015 and January 2018 in the Orthopedics Department of Shanxi Bethune Hospital were divided into 3 groups according to the complexity of imaging features: 18 patients in the mild group, 66 patients in the moderate group, and 55 patients in the severe group. The Visual Analog Scale (VAS) and Japanese Orthopaedic Association (JOA) scores were used to compare the effects of neck pain and neural function prior to surgery according to the rate of improvement as of the last follow-up. Routine X-ray films were obtained at the follow-up of 3-6 months. The necessity of computed tomography (CT) and magnetic resonance imaging (MRI) examinations was determined based on clinical findings and X-ray images. Analysis of variance (ANOVA) was used to compare groups, the least significant difference (LSD) test was used for multiple comparisons, and the Chi-square test was used to compare classification indicators (imaging manifestations, gender), with P<0.05 being statistically significant. Binary logistic regression analysis was performed to determine the primary influencing factors of the JOA recovery rate. Results: In all three groups, JOA and VAS scores at the final follow-up were significantly higher than those before surgery (P<0.001). There were significant differences in the preoperative VAS and JOA scores between any two groups, as well as in the VAS and JOA scores and improvement rates at the last follow-up between the mild group and the moderate group and between the mild group and the severe group (P<0.001). Age, preoperative JOA scores, MRI intramedullary hyperintensity signal, and the degree of spinal cord compression were primarily related to the nervous system recovery rate (P<0.001). Conclusions: Age, MRI intramedullary hyperintensity signal, degree of spinal cord compression, and other variables were associated with the improvement of neural function in patients with DCM. Therefore, in addition to the JOA improvement rate or VAS score, additional factors, such as the patient's condition, the improvement in quality of life, and the patient's financial capacity, should be considered in evaluating the improvement of postoperative neck pain and neural function.

13.
Cancer Lett ; 597: 217062, 2024 Jun 13.
Article in English | MEDLINE | ID: mdl-38878852

ABSTRACT

Immune checkpoint inhibitors (ICIs) have transformed cancer therapy, yet persistent challenges such as low response rate and significant heterogeneity necessitate attention. The pivotal role of the major histocompatibility complex (MHC) in ICI efficacy, its intricate impacts and potentials as a prognostic marker, warrants comprehensive exploration. This study integrates single-cell RNA sequencing (scRNA-seq), bulk RNA-seq, and spatial transcriptomic analyses to unveil pan-cancer immune characteristics governed by the MHC transcriptional feature (MHC.sig). Developed through scRNA-seq analysis of 663,760 cells across diverse cohorts and validated in 30 solid cancer types, the MHC.sig demonstrates a robust correlation between immune-related genes and infiltrating immune cells, highlighting its potential as a universal pan-cancer marker for anti-tumor immunity. Screening the MHC.sig for therapeutic targets using CRISPR data identifies potential genes for immune therapy synergy and validates its predictive efficacy for ICIs responsiveness across diverse datasets and cancer types. Finally, analysis of cellular communication patterns reveals interactions between C1QC+macrophages and malignant cells, providing insights into potential therapeutic agents and their sensitivity characteristics. This comprehensive analysis positions the MHC.sig as a promising marker for predicting immune therapy outcomes and guiding combinatorial therapeutic strategies.

14.
Org Lett ; 26(23): 5021-5026, 2024 Jun 14.
Article in English | MEDLINE | ID: mdl-38842216

ABSTRACT

We describe a simple and robust oxidation strategy for preparing N-terminal thiazolidine-containing peptide thioesters from peptide hydrazides. We find for the first time that l-thioproline can be used as a protective agent to prevent the nitrosation of N-terminal thiazolidine during peptide hydrazide oxidation. The thioproline-based oxidation strategy has been successfully applied to the chemical synthesis of CC chemokine ligand-2 (69aa) and omniligase-C (113aa), thereby demonstrating its utility in hydrazide-based native chemical ligation.


Subject(s)
Oxidation-Reduction , Peptides , Thiazolidines , Thiazolidines/chemistry , Thiazolidines/chemical synthesis , Molecular Structure , Peptides/chemistry , Peptides/chemical synthesis , Hydrazines/chemistry , Proline/chemistry , Esters/chemistry , Sulfhydryl Compounds/chemistry
15.
PLoS Negl Trop Dis ; 18(6): e0012231, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38865344

ABSTRACT

BACKGROUND: Malaria transmission-blocking vaccines (TBVs) aim to inhibit malaria parasite development in mosquitoes and prevent further transmission to the human host. The putative-secreted ookinete protein 25 (PSOP25), highly conserved in Plasmodium spp., is a promising TBV target. Here, we investigated PvPSOP25 from P. vivax as a TBV candidate using transgenic murine parasite P. berghei and clinical P. vivax isolates. METHODS AND FINDINGS: A transgenic P. berghei line expressing PvPSOP25 (TrPvPSOP25Pb) was generated. Full-length PvPSOP25 was expressed in the yeast Pichia pastoris and used to immunize mice to obtain anti-rPvPSOP25 sera. The transmission-blocking activity of the anti-rPvPSOP25 sera was evaluated through in vitro assays and mosquito-feeding experiments. The antisera generated by immunization with rPvPSOP25 specifically recognized the native PvPSOP25 antigen expressed in TrPvPSOP25Pb ookinetes. In vitro assays showed that the immune sera significantly inhibited exflagellation and ookinete formation of the TrPvPSOP25Pb parasite. Mosquitoes feeding on mice infected with the transgenic parasite and passively transferred with the anti-rPvPSOP25 sera showed a 70.7% reduction in oocyst density compared to the control group. In a direct membrane feeding assay conducted with five clinical P. vivax isolates, the mouse anti-rPvPSOP25 antibodies significantly reduced the oocyst density while showing a negligible influence on mosquito infection prevalence. CONCLUSIONS: This study supported the feasibility of transgenic murine malaria parasites expressing P. vivax antigens as a useful tool for evaluating P. vivax TBV candidates. Meanwhile, the moderate transmission-reducing activity of the generated anti-rPvPSOP25 sera necessitates further research to optimize its efficacy.


Subject(s)
Malaria Vaccines , Malaria, Vivax , Plasmodium berghei , Plasmodium vivax , Protozoan Proteins , Animals , Mice , Plasmodium vivax/genetics , Plasmodium vivax/immunology , Malaria Vaccines/immunology , Malaria Vaccines/administration & dosage , Plasmodium berghei/genetics , Plasmodium berghei/immunology , Protozoan Proteins/genetics , Protozoan Proteins/immunology , Humans , Malaria, Vivax/transmission , Malaria, Vivax/parasitology , Malaria, Vivax/prevention & control , Malaria, Vivax/immunology , Female , Antigens, Protozoan/genetics , Antigens, Protozoan/immunology , Antibodies, Protozoan/blood , Antibodies, Protozoan/immunology , Malaria/transmission , Malaria/prevention & control , Malaria/parasitology , Malaria/immunology , Mice, Inbred BALB C
16.
Opt Lett ; 49(11): 2942-2945, 2024 Jun 01.
Article in English | MEDLINE | ID: mdl-38824298

ABSTRACT

In this Letter, an optically transparent and broadband absorber designed using a multi-objective genetic algorithm (MOGA) is proposed. The absorption of the multilayer lossy frequency selective surface-based absorber is calculated by multilayer absorption equations and equivalent circuit models. To solve the problem of the unbalanced structure absorption bandwidth and thickness, an algorithm is used for optimizing the geometric and sheet resistance parameters of the structure. A multilayer and optically transparent absorber with 90% absorption bandwidth covering a frequency range of 2-18 GHz (S-band to Ku-band) is developed based on the MOGA design method with optical transmittance of 60%. Its total thickness consists of a wavelength of only 0.095, and it has high oblique incidence stability, which makes it useful in the stealth technology and transparent electromagnetic shielding applications.

17.
Ecology ; : e4375, 2024 Jun 26.
Article in English | MEDLINE | ID: mdl-38924062

ABSTRACT

Fungi are key decomposers of deadwood, but the impact of anthropogenic changes in nutrients and temperature on fungal community and its consequences for wood microbial respiration are not well understood. Here, we examined how nitrogen and phosphorus additions (field experiment) and warming (laboratory experiment) together influence fungal composition and microbial respiration from decomposing wood of angiosperms and gymnosperms in a subtropical forest. Nutrient additions significantly increased wood microbial respiration via fungal composition, but effects varied with nutrient types and taxonomic groups. Specifically, phosphorus addition significantly increased wood microbial respiration (65%) through decreased acid phosphatase activity and increased abundance of fast-decaying fungi (e.g., white rot), while nitrogen addition marginally increased it (30%). Phosphorus addition caused a greater increase in microbial respiration in gymnosperms than in angiosperms (83.3% vs. 46.9%), which was associated with an increase in Basidiomycota:Ascomycota operational taxonomic unit abundance in gymnosperms but a decrease in angiosperms. The temperature dependencies of microbial respiration were remarkably constant across nutrient levels, consistent with metabolic scaling theory hypotheses. This is because there was no significant interaction between temperature and wood phosphorus availability or fungal composition, or the interaction among the three factors. Our results highlight the key role of tree identity in regulating nutrient response of wood microbial respiration through controlling fungal composition. Given that the range of angiosperm species may expand under climate warming and forest management, our data suggest that expansion will decrease nutrient effects on forest carbon cycling in forests previously dominated by gymnosperm species.

18.
Chem Sci ; 15(25): 9649-9656, 2024 Jun 26.
Article in English | MEDLINE | ID: mdl-38939140

ABSTRACT

With the increasing attention paid to macrocyclic scaffolds in peptide drug development, genetically encoded peptide macrocycle libraries have become invaluable sources for the discovery of high-affinity peptide ligands targeting disease-associated proteins. The traditional phage display technique of constructing disulfide-tethered macrocycles by cysteine oxidation has the inherent drawback of reduction instability of the disulfide bond. Chemical macrocyclization solves the problem of disulfide bond instability, but the involved highly electrophilic reagents are usually toxic to phages and may bring undesirable side reactions. Here, we report a unique Sortase-mediated Peptide Ligation and One-pot Cyclization strategy (SPLOC) to generate peptide macrocycle libraries, avoiding the undesired reactions of electrophiles with phages. The key to this platform is to mine the unnatural promiscuity of sortase on the X residue of the pentapeptide recognition sequence (LPXTG). Low reactive electrophiles are incorporated into the X-residue side chain, enabling intramolecular cyclization with the cysteine residue of the phage-displayed peptide library. Utilizing the genetically encoded peptide macrocycle library constructed by the SPLOC platform, we found a high-affinity bicyclic peptide binding TEAD4 with a nanomolar KD value (63.9 nM). Importantly, the binding affinity of the bicyclic peptide ligand is 102-fold lower than that of the acyclic analogue. To our knowledge, this is the first time to mine the unnatural promiscuity of ligases to generate peptide macrocycles, providing a new avenue for the construction of genetically encoded cyclic peptide libraries.

19.
Molecules ; 29(11)2024 May 24.
Article in English | MEDLINE | ID: mdl-38893358

ABSTRACT

Pseudoginsenoside DQ (PDQ), an ocotillol-type ginsenoside, is synthesized with protopanaxadiol through oxidative cyclization. PDQ exhibits good anti-arrhythmia activity. However, the inhibitory effect of PDQ on the cytochrome 450 (CYP450) enzymes and major drug transporters is still unclear. Inhibition of CYP450 and drug transporters may affect the efficacy of the drugs being used together with PDQ. These potential drug-drug interactions (DDIs) are essential for the clinical usage of drugs. In this study, we investigated the inhibitory effect of PDQ on seven CYP450 enzymes and seven drug transporters with in vitro models. PDQ has a significant inhibitory effect on CYP2C19 and P-glycoprotein (P-gp) with a half-inhibitory concentration (IC50) of 0.698 and 0.41 µM, respectively. The inhibition of CYP3A4 and breast cancer-resistant protein (BCRP) is less potent, with IC50 equal to 2.02-6.79 and 1.08 µM, respectively.


Subject(s)
Cytochrome P-450 Enzyme System , Drug Interactions , Ginsenosides , Humans , Ginsenosides/pharmacology , Ginsenosides/chemistry , Cytochrome P-450 Enzyme System/metabolism , Cytochrome P-450 Enzyme Inhibitors/pharmacology , ATP Binding Cassette Transporter, Subfamily G, Member 2/metabolism , Cytochrome P-450 CYP3A/metabolism , Cytochrome P-450 CYP2C19/metabolism , Neoplasm Proteins/metabolism , Neoplasm Proteins/antagonists & inhibitors
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