Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 1.286
Filter
2.
FASEB Bioadv ; 6(5): 131-142, 2024 May.
Article in English | MEDLINE | ID: mdl-38706754

ABSTRACT

The leading cause of death among patients with metabolic dysfunction-associated steatotic liver disease (MASLD) is cardiovascular disease. A significant percentage of MASLD patients develop heart failure driven by functional and structural alterations in the heart. Previously, we observed cardiac dysfunction in hepatocyte-specific peroxisome proliferator-activated receptor alpha knockout (Ppara HepKO), a mouse model that exhibits hepatic steatosis independent of obesity and insulin resistance. The goal of the present study was to determine mechanisms that underlie hepatic steatosis-induced cardiac dysfunction in Ppara HepKO mice. Experiments were performed in 30-week-old Ppara HepKO and littermate control mice fed regular chow. We observed decreased cardiomyocyte contractility (0.17 ± 0.02 vs. 0.24 ± 0.02 µm, p < 0.05), increased cardiac triglyceride content (0.96 ± 0.13 vs. 0.68 ± 0.06 mM, p < 0.05), collagen type 1 (4.65 ± 0.25 vs. 0.31 ± 0.01 AU, p < 0.001), and collagen type 3 deposition (1.32 ± 0.46 vs. 0.05 ± 0.03 AU, p < 0.05). These changes were associated with increased apoptosis as indicated by terminal deoxynucleotidyl transferase dUTP nick end labeling staining (30.9 ± 4.7 vs. 13.1 ± 0.8%, p < 0.006) and western blots showing increased cleaved caspase-3 (0.27 ± 0.006 vs. 0.08 ± 0.01 AU, p < 0.003) and pro-caspase-3 (5.4 ± 1.5 vs. 0.5 ± 0.3 AU, p < 0.02), B-cell lymphoma protein 2-associated X (0.68 ± 0.07 vs. 0.04 ± 0.04 AU, p < 0.001), and reduced B-cell lymphoma protein 2 (0.29 ± 0.01 vs. 1.47 ± 0.54 AU, p < 0.05). We further observed elevated circulating natriuretic peptides and exercise intolerance in Ppara HepKO mice when compared to controls. Our data demonstrated that lipotoxicity, and fibrosis underlie cardiac dysfunction in MASLD.

3.
Polymers (Basel) ; 16(9)2024 May 03.
Article in English | MEDLINE | ID: mdl-38732752

ABSTRACT

In this research work, a coated paper was prepared with poly (butylene adipate-co-terephthalate) (PBAT) film to explore its use in eco-friendly food packaging. The paper was coated with PBAT film for packaging using hot pressing, a production method currently employed in the packaging industry. The coated papers were evaluated for their structural, mechanical, thermal, and barrier properties. The structural morphology and chemical analysis of the coated paper confirmed the consistent formation of PBAT bi-layered on paper surfaces. Surface coating with PBAT film increased the water resistance of the paper samples, as demonstrated by tests of barrier characteristics, including the water vapor transmission rate (WVTR), oxygen transmission rate (OTR), and water contact angle (WCA) of water drops. The transmission rate of the clean paper was 2010.40 cc m-2 per 24 h for OTR and 110.24 g m-2 per 24 h for WVTR. If the PBAT-film was coated, the value decreased to 91.79 g m-2 per 24 h and 992.86 cc m-2 per 24 h. The hydrophobic nature of PBAT, confirmed by WCA measurements, contributed to the enhanced water resistance of PBAT-coated paper. This result presents an improved PBAT-coated paper material, eliminating the need for adhesives and allowing for the fabrication of bi-layered packaging.

4.
Am J Epidemiol ; 2024 May 17.
Article in English | MEDLINE | ID: mdl-38754872

ABSTRACT

Childhood adversity is an important risk factor for adverse health across the life course. Epigenetic modifications, such as DNA methylation (DNAm), are one hypothesized mechanism linking adversity to disease susceptibility. Yet, few studies have determined whether adversity-related DNAm alterations are causally related to future health outcomes or if their developmental timing plays a role in these relationships. Here, we used two-sample Mendelian Randomization to obtain stronger causal inferences about the association between adversity-associated DNAm loci across development (i.e., birth; childhood; adolescence; young adulthood) and 24 mental, physical, and behavioral health outcomes. We identified particularly strong associations between adversity-associated DNAm and ADHD, depression, obsessive-compulsive disorder, suicide attempts, asthma, coronary artery disease, and chronic kidney disease. A greater number of associations were identified for birth and childhood DNAm, while adolescent and young adulthood DNAm were more closely linked to mental health. Childhood DNAm loci also showed primarily risk suppressing relationships with health outcomes, suggesting that DNAm might reflect compensatory or buffering mechanisms against childhood adversity, rather than acting solely as an indicator of disease risk. Together, our results suggest adversity-related DNAm alterations are linked to both physical and mental health outcomes, with particularly strong impacts of DNAm differences emerging earlier in development.

5.
J Fungi (Basel) ; 10(5)2024 Apr 28.
Article in English | MEDLINE | ID: mdl-38786678

ABSTRACT

When cultivating on wheat bran or deactivated fungal mycelium as a model of "natural growth", the ability of Trichoderma to synthesize extracellular L-lysine-α-oxidase (LysO) simultaneously with cell-wall-degrading enzymes (proteases, xylanase, glucanases, chitinases, etc.), responsible for mycoparasitism, was shown. LysO, in turn, causes the formation of H2O2 and pipecolic acid. These compounds are known to be signaling molecules and play an important role in the induction and development of systemic acquired resistance in plants. Antagonistic effects of LysO have been demonstrated against phytopathogenic fungi and Gram-positive or Gram-negative bacteria with dose-dependent cell death. The antimicrobial effect of LysO decreased in the presence of catalase. The generating intracellular ROS in the presence of LysO was also shown in both bacteria and fungi, which led to a decrease in viable cells. These results suggest that the antimicrobial activity of LysO is due to two factors: the formation of exogenous hydrogen peroxide as a product of the enzymatic oxidative deamination of L-lysine and the direct interaction of LysO with the cell wall of the micro-organisms. Thus, LysO on its own enhances the potential of the producer in the environment; namely, the enzyme complements the strategy of the fungus in biocontrol and indirectly participates in inducing SAR and regulating the relationship between pathogens and plants.

6.
Polymers (Basel) ; 16(7)2024 Mar 29.
Article in English | MEDLINE | ID: mdl-38611195

ABSTRACT

Biobased plastics provide a sustainable alternative to conventional food packaging materials, thereby reducing the environmental impact. The present study investigated the effectiveness of chitosan with varying levels of Moringa oleifera seed powder (MOSP) and tannic acid (TA). Chitosan (CS) biocomposite films with tannic acid acted as a cross-linker, and Moringa oleifera seed powder served as reinforcement. To enhance food packaging and film performance, Moringa oleifera seed powder was introduced at various loadings of 1.0, 3.0, 5.0, and 10.0 wt.%. Fourier-transform infrared spectroscopy, X-ray diffraction, and scanning electron microscopy analyses were performed to study the structure and morphology of the CS/TA/MOSP films. The scanning electron microscopy results confirmed that chitosan/TA with 10.0 wt.% of MOSP produced a lightly miscible droplet/matrix structure. Furthermore, mechanical properties, swelling, water solubility, optical barrier, and water contact angle properties of the film were also calculated. With increasing Moringa oleifera seed powder contents, the biocomposite films' antimicrobial and antifungal activity increased at the 10.0 wt.% MOSP level; all of the observed bacteria [Staphylococcus aureus (S. aureus), Escherichia coli (E. coli), Aspergillus niger (A. niger), and Candida albicans (C. albicans)] had a notably increased percentage of growth. The film, with 10.0 wt.% MOSP content, effectively preserves strawberries' freshness, making it an ideal food packaging material.

7.
Molecules ; 29(7)2024 Mar 25.
Article in English | MEDLINE | ID: mdl-38611744

ABSTRACT

The green synthesis of zinc oxide nanoparticles (ZnO NPs) using plants has grown in significance in recent years. ZnO NPs were synthesized in this work via a chemical precipitation method with Jasminum sambac (JS) leaf extract serving as a capping agent. These NPs were characterized using UV-vis spectroscopy, FT-IR, XRD, SEM, TEM, TGA, and DTA. The results from UV-vis and FT-IR confirmed the band gap energies (3.37 eV and 3.50 eV) and the presence of the following functional groups: CN, OH, C=O, and NH. A spherical structure and an average grain size of 26 nm were confirmed via XRD. The size and surface morphology of the ZnO NPs were confirmed through the use of SEM analysis. According to the TEM images, the ZnO NPs had an average mean size of 26 nm and were spherical in shape. The TGA curve indicated that the weight loss starts at 100 °C, rising to 900 °C, as a result of the evaporation of water molecules. An exothermic peak was seen during the DTA analysis at 480 °C. Effective antibacterial activity was found at 7.32 ± 0.44 mm in Gram-positive bacteria (S. aureus) and at 15.54 ± 0.031 mm in Gram-negative (E. coli) bacteria against the ZnO NPs. Antispasmodic activity: the 0.3 mL/mL sample solution demonstrated significant reductions in stimulant effects induced by histamine (at a concentration of 1 µg/mL) by (78.19%), acetylcholine (at a concentration of 1 µM) by (67.57%), and nicotine (at a concentration of 2 µg/mL) by (84.35%). The antipyretic activity was identified using the specific Shodhan vidhi method, and their anti-inflammatory properties were effectively evaluated with a denaturation test. A 0.3 mL/mL sample solution demonstrated significant reductions in stimulant effects induced by histamine (at a concentration of 1 µg/mL) by 78.19%, acetylcholine (at a concentration of 1 µM) by 67.57%, and nicotine (at a concentration of 2 µg/mL) by 84.35%. These results underscore the sample solution's potential as an effective therapeutic agent, showcasing its notable antispasmodic activity. Among the administered doses, the 150 mg/kg sample dose exhibited the most potent antipyretic effects. The anti-inflammatory activity of the synthesized NPs showed a remarkable inhibition percentage of (97.14 ± 0.005) at higher concentrations (250 µg/mL). Furthermore, a cytotoxic effect was noted when the biologically synthesized ZnO NPs were introduced to treated cells.


Subject(s)
Antipyretics , Jasminum , Nanoparticles , Zinc Oxide , Zinc Oxide/pharmacology , Parasympatholytics , Acetylcholine , Escherichia coli , Histamine , Nicotine , Spectroscopy, Fourier Transform Infrared , Staphylococcus aureus , Anti-Inflammatory Agents/pharmacology , Anti-Bacterial Agents/pharmacology , Plant Extracts/pharmacology
8.
An Acad Bras Cienc ; 96(1): e20230539, 2024.
Article in English | MEDLINE | ID: mdl-38597500

ABSTRACT

Green manure (GM) may reduce the use of chemical fertilizers, been an ecologically appropriate strategy to cultivation of medicinal plants. Crotalaria juncea, is one of the most used because it adapts to different climatic and high nitrogen content. Origanum vulgare. is widely used in cooking, pharmaceutical, cosmetic industries and food products. The objectives of this study were to evaluate the GM on biomass, essential oil (EO), phenolic and antioxidant. The experiment consisted: control; 150, 300, 450, and 600 g (Sh= leaves+steam) more 200 g roots (R); 600 g aerial part; 200 g roots; and soil with 300 g cattle manure per pot. The highest dry weights were observed in the presence of GM and cattle manure (90 days). The control had an EO production 75% lower in relation to the dose of 450 g GM (Sh+R). Principal component analysis showed that GM and cattle manure positively influenced the dry weight, content, yield, and EO constituents, and total flavonoids. The GM contributed to the accumulation of the major EO compounds (trans-sabinene hydrate, thymol, terpinen-4-ol). The GM management may be beneficial for cultivating, because it can increase the production of biomass and the active components, in addition to being an inexpensive resource.


Subject(s)
Crotalaria , Oils, Volatile , Origanum , Cattle , Animals , Oils, Volatile/chemistry , Origanum/chemistry , Manure , Biomass , Phytochemicals
9.
Shock ; 61(6): 861-868, 2024 Jun 01.
Article in English | MEDLINE | ID: mdl-38662598

ABSTRACT

ABSTRACT: There is evidence to suggest that the hypothermia observed in the most severe cases of systemic inflammation or sepsis is a regulated response with potential adaptive value, but the mechanisms involved are poorly understood. Here, we investigated the interplay between brain oxygenation (assessed by tissue P o2 ) and the development of hypothermia in unanesthetized rats challenged with a hypotension-inducing dose of bacterial LPS (1 mg/kg i.v.). At an ambient temperature of 22°C, oxygen consumption (V̇O 2 ) began to fall only a few minutes after the LPS injection, and this suppression in metabolic rate preceded the decrease in core temperature. No reduction in brain P o2 was observed prior to the development of the hypometabolic, hypothermic response, ruling out the possibility that brain hypoxia served as a trigger for hypothermia in this model. Brain P o2 was even increased. Such an improvement in brain oxygenation could reflect either an increased O 2 delivery or a decreased O 2 consumption. The former explanation seems unlikely because blood flow (cardiac output) was being progressively decreased during the recording period. On the other hand, the decrease in V̇O 2 usually preceded the rise in P o2 , and an inverse correlation between V̇O 2 and brain P o2 was consistently observed. These findings do not support the existence of a closed-loop feedback relationship between brain oxygenation and hypothermia in systemic inflammation. The data are consistent with a feedforward mechanism in which hypothermia is triggered (possibly by cryogenic inflammatory mediators) in anticipation of changes in brain oxygenation to prevent the development of tissue hypoxia.


Subject(s)
Brain , Hypothermia , Oxygen Consumption , Oxygen , Shock, Septic , Animals , Brain/metabolism , Rats , Male , Shock, Septic/metabolism , Shock, Septic/physiopathology , Oxygen Consumption/physiology , Oxygen/metabolism , Hypothermia/metabolism , Hypothermia/physiopathology , Lipopolysaccharides , Rats, Wistar
10.
Article in English | MEDLINE | ID: mdl-38654146

ABSTRACT

Evidence suggests that MDMA-assisted psychotherapy (MDMA-AP) has therapeutic potential for treatment of psychiatric illness. We conducted the first comprehensive systematic review and meta-analysis of the side effects of MDMA-AP across indications. We also assessed the quality of side effects-reporting in published trials of MDMA-AP. PubMed, EMBASE, PsycINFO, MEDLINE and Cochrane Central Register of Controlled Trials (CENTRAL) were systematically searched. Phase 2 and 3 MDMA-AP studies were included; Phase 1 studies, which assessed MDMA without psychotherapy, were not. Quality of side effects-reporting was assessed against the CONSORT Harms 2022 guidelines. We also compared numbers of adverse events reported in publications to those recorded in ClinicalTrial.gov registers. Thirteen studies were included, with eight contributing to the meta-analysis. In Phase 2 studies, MDMA-AP was associated with increased odds of any side effect during medication sessions (OR = 1.67, 95%CI (1.12, 2.49)) and in the 7 days following (OR = 1.59, 95%CI (1.12, 2.24)) relative to control conditions. In Phase 3 studies, MDMA-AP was associated with increased odds of any adverse event during the treatment period relative to placebo-assisted psychotherapy (OR = 3.51, 95%CI (2.76, 4.46)). The majority of RCTs were rated as having high risk of bias. Certainty of the evidence was rated as very low to moderate according to the GRADE framework. No included RCT had adequate adherence to the CONSORT Harms 2022 recommendations and reporting rates were also low. Compared to placebo, MDMA-AP was associated with increased odds of side effects, which were largely transient and mild or moderate in severity. However, identified limitations in existing evidence indicate that further investigation is needed to better characterize the safety profile of MDMA-AP and guide implementation.

11.
Am J Physiol Renal Physiol ; 326(5): F727-F736, 2024 May 01.
Article in English | MEDLINE | ID: mdl-38511219

ABSTRACT

Although obesity is recognized as a risk factor for cardiorenal and metabolic diseases, the impact of parental obesity on the susceptibility of their offspring to renal injury at adulthood is unknown. We examined the impact of parental obesity on offspring kidney function, morphology, and markers of kidney damage after acute kidney injury (AKI). Offspring from normal (N) diet-fed C57BL/6J parents were fed either N (NN) or a high-fat (H) diet (NH) from weaning until adulthood. Offspring from obese H diet-fed parents were fed N (HN) or H diet (HH) after weaning. All offspring groups were submitted to bilateral AKI by clamping the left and right renal pedicles for 30 min. Compared with male NH and NN offspring from lean parents, male HH and HN offspring from obese parents exhibited higher kidney injury markers such as urinary, renal osteopontin, plasma creatinine, urinary albumin excretion, and neutrophil gelatinase-associated lipocalin (NGAL) levels, and worse histological injury score at 22 wk of age. Only albumin excretion and NGAL were elevated in female HH offspring from obese parents compared with lean and obese offspring from lean parents. We also found an increased mortality rate and worse kidney injury scores after AKI in male offspring from obese parents, regardless of the diet consumed after weaning. Female offspring were protected from major kidney injury after AKI. These results indicate that parental obesity leads to increased kidney injury in their offspring after ischemia-reperfusion in a sex-dependent manner, even when their offspring remain lean.NEW & NOTEWORTHY Offspring from obese parents are more susceptible to kidney injury and worse outcomes following an acute ischemia-reperfusion insult. Male, but not female, offspring from obese parents exhibit increased blood pressure early in life. Female offspring are partially protected against major kidney injury induced by ischemia-reperfusion.


Subject(s)
Acute Kidney Injury , Kidney , Mice, Inbred C57BL , Reperfusion Injury , Animals , Male , Female , Reperfusion Injury/pathology , Reperfusion Injury/metabolism , Acute Kidney Injury/etiology , Acute Kidney Injury/metabolism , Acute Kidney Injury/physiopathology , Acute Kidney Injury/pathology , Kidney/physiopathology , Kidney/pathology , Kidney/metabolism , Sex Factors , Obesity/complications , Obesity/physiopathology , Diet, High-Fat , Pregnancy , Lipocalin-2/metabolism , Obesity, Maternal/metabolism , Obesity, Maternal/complications , Obesity, Maternal/physiopathology , Prenatal Exposure Delayed Effects , Mice , Risk Factors , Disease Models, Animal , Biomarkers/blood
12.
Polymers (Basel) ; 16(6)2024 Mar 11.
Article in English | MEDLINE | ID: mdl-38543380

ABSTRACT

The structural and electro-thermophysical characteristics of organosilicon elastomers modified with multilayer carbon nanotubes (MWCNTs) synthesized on Co-Mo/Al2O3-MgO and metallic (Cu or Ni) microparticles have been studied. The structures were analyzed with scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopy, and energy-dispersive X-ray spectroscopy (EDX). The main focus of this study was the influence of metallic dispersed fillers on the resistance of a modified elastomer with Cu and Ni to the degradation of electrophysical parameters under the action of applied electrical voltage. The distribution of the temperature field on the surface of a modified polymer composite with metallic micro-dimensional structures has been recorded. The collected data demonstrate the possibility of controlling the degradation caused by electrical voltage. It has been found that repeated on/off turns of the elastomer with an MWCNTs on 50 and 100 cycles leads to a deterioration in the properties of the conductive elastomer from the available power of 1.1 kW/m2 (-40 °C) and, as a consequence, a decrease in the power to 0.3 kW/m2 (-40 °C) after 100 on/off cycles. At the same time, the Ni additive allows increasing the power by 1.4 kW/m2 (-40 °C) and reducing the intensity of the degradation of the conductive structures (after 100 on/off cycles up to 1.2 kW/m2 (-40 °C). When Ni is replaced by Cu, the power of the modified composite in the heating mode increases to 1.6 kW/m2 (-40 °C) and, at the same time, the degradation of the conductive structures in the composite decreases in the mode of cyclic offensives (50 and 100 cycles) (1.5 kW/m2 (-40 °C)). It was found that the best result in terms of heat removal is typical for an elastomer sample with an MWCNTs and Cu (temperature reaches 93.9 °C), which indicates an intensification of the heat removal from the most overheated places of the composite structure. At the same time, the maximum temperature for the Ni additives reaches 86.7 °C. A sample without the addition of a micro-sized metal is characterized by the local unevenness of the temperature field distribution, which causes undesirable internal overheating and destruction of the current-conducting structures based on the MWCNTs. The maximum temperature at the same time reaches a value of 49.8 °C. The conducted studies of the distribution of the micro-sizes of Ni and Cu show that Cu, due to its larger particles, improves internal heat exchange and intensifies heat release to the surface of the heater sample, which improves the temperature regime of the MWCNTs and, accordingly, increases resistance to electrophysical degradation.

13.
Anal Chem ; 96(14): 5392-5398, 2024 Apr 09.
Article in English | MEDLINE | ID: mdl-38526848

ABSTRACT

Along with mass spectrometry (MS), ion mobility separations (IMS) are advancing to ever larger biomolecules. The emergence of electrospray ionization (ESI) and native MS enabled the IMS/MS analyses of proteins up to ∼100 kDa in the 1990s and whole protein complexes and viruses up to ∼10 MDa since the 2000s. Differential IMS (FAIMS) is substantially orthogonal to linear IMS based on absolute mobility K and offers exceptional resolution, unique selectivity, and steady filtering readily compatible with slower analytical methods such as electron capture or transfer dissociation (ECD/ETD). However, the associated MS stages had limited FAIMS to ions with m/z < 8000 and masses under ∼300 kDa. Here, we integrate high-definition FAIMS with the Q-Exactive Orbitrap UHMR mass spectrometer that can handle m/z up to 80,000 and MDa-size ions in the native ESI regime. In the initial evaluation, the oligomers of monoclonal antibody adalimumab (148 kDa) are size-selected up to at least the nonamers (1.34 MDa) with m/z values up to ∼17,000. This demonstrates the survival and efficient separation of noncovalent MDa assemblies in the FAIMS process, opening the door to novel analyses of the heaviest macromolecules.


Subject(s)
Ion Mobility Spectrometry , Proteins , Mass Spectrometry/methods , Proteins/chemistry , Ions
14.
Acad Emerg Med ; 31(6): 564-575, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38497320

ABSTRACT

OBJECTIVES: We previously described derivation and validation of the emergency department trigger tool (EDTT) for adverse event (AE) detection. As the first step in our multicenter study of the tool, we validated our computerized screen for triggers against manual review, establishing our use of this automated process for selecting records to review for AEs. METHODS: This is a retrospective observational study of visits to three urban, academic EDs over 18 months by patients ≥ 18 years old. We reviewed 912 records: 852 with at least one of 34 triggers found by the query and 60 records with none. Two first-level reviewers per site each manually screened for triggers. After completion, computerized query results were revealed, and reviewers could revise their findings. Second-level reviewers arbitrated discrepancies. We compare automated versus manual screening by positive and negative predictive values (PPVs, NPVs), present population trigger frequencies, proportions of records triggered, and how often manual ratings were changed to conform with the query. RESULTS: Trigger frequencies ranged from common (>25%) to rare (1/1000) were comparable at U.S. sites and slightly lower at the Canadian site. Proportions of triggered records ranged from 31% to 49.4%. Overall query PPV was 95.4%; NPV was 99.2%. PPVs for individual trigger queries exceeded 90% for 28-31 triggers/site and NPVs were >90% for all but three triggers at one site. Inter-rater reliability was excellent, with disagreement on manual screening results less than 5% of the time. Overall, reviewers amended their findings 1.5% of the time when discordant with query findings, more often when the query was positive than when negative (47% vs. 23%). CONCLUSIONS: The EDTT trigger query performed very well compared to manual review. With some expected variability, trigger frequencies were similar across sites and proportions of triggered records ranged 31%-49%. This demonstrates the feasibility and generalizability of implementing the EDTT query, providing a solid foundation for testing the triggers' utility in detecting AEs.


Subject(s)
Emergency Service, Hospital , Adult , Female , Humans , Male , Middle Aged , Canada , Emergency Service, Hospital/statistics & numerical data , Medical Errors/statistics & numerical data , Reproducibility of Results , Retrospective Studies , United States
15.
Nat Commun ; 15(1): 1807, 2024 Feb 28.
Article in English | MEDLINE | ID: mdl-38418512

ABSTRACT

Understanding the complex relationships between enzyme sequence, folding stability and catalytic activity is crucial for applications in industry and biomedicine. However, current enzyme assay technologies are limited by an inability to simultaneously resolve both stability and activity phenotypes and to couple these to gene sequences at large scale. Here we present the development of enzyme proximity sequencing, a deep mutational scanning method that leverages peroxidase-mediated radical labeling with single cell fidelity to dissect the effects of thousands of mutations on stability and catalytic activity of oxidoreductase enzymes in a single experiment. We use enzyme proximity sequencing to analyze how 6399 missense mutations influence folding stability and catalytic activity in a D-amino acid oxidase from Rhodotorula gracilis. The resulting datasets demonstrate activity-based constraints that limit folding stability during natural evolution, and identify hotspots distant from the active site as candidates for mutations that improve catalytic activity without sacrificing stability. Enzyme proximity sequencing can be extended to other enzyme classes and provides valuable insights into biophysical principles governing enzyme structure and function.


Subject(s)
Mutation, Missense , Mutation , Enzyme Stability
16.
PLoS Genet ; 20(2): e1011158, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38359090

ABSTRACT

Elucidating gene function is a major goal in biology, especially among non-model organisms. However, doing so is complicated by the fact that molecular conservation does not always mirror functional conservation, and that complex relationships among genes are responsible for encoding pathways and higher-order biological processes. Co-expression, a promising approach for predicting gene function, relies on the general principal that genes with similar expression patterns across multiple conditions will likely be involved in the same biological process. For Cryptococcus neoformans, a prevalent human fungal pathogen greatly diverged from model yeasts, approximately 60% of the predicted genes in the genome lack functional annotations. Here, we leveraged a large amount of publicly available transcriptomic data to generate a C. neoformans Co-Expression Network (CryptoCEN), successfully recapitulating known protein networks, predicting gene function, and enabling insights into the principles influencing co-expression. With 100% predictive accuracy, we used CryptoCEN to identify 13 new DNA damage response genes, underscoring the utility of guilt-by-association for determining gene function. Overall, co-expression is a powerful tool for uncovering gene function, and decreases the experimental tests needed to identify functions for currently under-annotated genes.


Subject(s)
Cryptococcosis , Cryptococcus neoformans , Humans , Cryptococcus neoformans/genetics , Cryptococcosis/genetics , Cryptococcosis/microbiology , DNA Repair/genetics , Phenotype , DNA Damage/genetics , Fungal Proteins/genetics
17.
Nature ; 627(8004): 564-571, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38418889

ABSTRACT

Numerous studies have shown reduced performance in plants that are surrounded by neighbours of the same species1,2, a phenomenon known as conspecific negative density dependence (CNDD)3. A long-held ecological hypothesis posits that CNDD is more pronounced in tropical than in temperate forests4,5, which increases community stabilization, species coexistence and the diversity of local tree species6,7. Previous analyses supporting such a latitudinal gradient in CNDD8,9 have suffered from methodological limitations related to the use of static data10-12. Here we present a comprehensive assessment of latitudinal CNDD patterns using dynamic mortality data to estimate species-site-specific CNDD across 23 sites. Averaged across species, we found that stabilizing CNDD was present at all except one site, but that average stabilizing CNDD was not stronger toward the tropics. However, in tropical tree communities, rare and intermediate abundant species experienced stronger stabilizing CNDD than did common species. This pattern was absent in temperate forests, which suggests that CNDD influences species abundances more strongly in tropical forests than it does in temperate ones13. We also found that interspecific variation in CNDD, which might attenuate its stabilizing effect on species diversity14,15, was high but not significantly different across latitudes. Although the consequences of these patterns for latitudinal diversity gradients are difficult to evaluate, we speculate that a more effective regulation of population abundances could translate into greater stabilization of tropical tree communities and thus contribute to the high local diversity of tropical forests.


Subject(s)
Biodiversity , Forests , Geographic Mapping , Trees , Models, Biological , Species Specificity , Trees/classification , Trees/physiology , Tropical Climate
18.
Anal Chem ; 96(6): 2318-2326, 2024 02 13.
Article in English | MEDLINE | ID: mdl-38301112

ABSTRACT

Ion mobility spectrometry (IMS) coupled to mass spectrometry (MS) has become a versatile tool to fractionate complex mixtures, distinguish structural isomers, and elucidate molecular geometries. Along with the whole MS field, IMS/MS advances to ever larger species. A topical proteomic problem is the discovery and characterization of d-amino acid-containing peptides (DAACPs) that are critical to neurotransmission and toxicology. Both linear IMS and FAIMS previously disentangled d/l epimers with up to ∼30 residues. In the first study using all three most powerful IMS methodologies─trapped IMS, cyclic IMS, and FAIMS─we demonstrate baseline resolution of the largest known d/l peptides (CHH from Homarus americanus with 72 residues) with a dynamic range up to 100. This expands FAIMS analyses of isomeric modified peptides, especially using hydrogen-rich buffers, to the ∼50-100 residue range of small proteins. The spectra for d and l are unprecedentedly strikingly similar except for a uniform shift of the separation parameter, indicating the conserved epimer-specific structural elements across multiple charge states and conformers. As the interepimer resolution tracks the average for smaller DAACPs, the IMS approaches could help search for yet larger DAACPs. The a priori method to calibrate cyclic (including multipass) IMS developed here may be broadly useful.


Subject(s)
Peptides , Proteomics , Peptides/chemistry , Mass Spectrometry/methods , Proteins , Ion Mobility Spectrometry , Amino Acids/chemistry
19.
Nat Commun ; 15(1): 986, 2024 Feb 02.
Article in English | MEDLINE | ID: mdl-38307857

ABSTRACT

Microalgae are a renewable and promising biomass for large-scale biofuel, food and nutrient production. However, their efficient exploitation depends on our knowledge of the cell wall composition and organization as it can limit access to high-value molecules. Here we provide an atomic-level model of the non-crystalline and water-insoluble glycoprotein-rich cell wall of Chlamydomonas reinhardtii. Using in situ solid-state and sensitivity-enhanced nuclear magnetic resonance, we reveal unprecedented details on the protein and carbohydrate composition and their nanoscale heterogeneity, as well as the presence of spatially segregated protein- and glycan-rich regions with different dynamics and hydration levels. We show that mannose-rich lower-molecular-weight proteins likely contribute to the cell wall cohesion by binding to high-molecular weight protein components, and that water provides plasticity to the cell-wall architecture. The structural insight exemplifies strategies used by nature to form cell walls devoid of cellulose or other glycan polymers.


Subject(s)
Chlamydomonas reinhardtii , Chlamydomonas , Chlamydomonas reinhardtii/metabolism , Glycoproteins/metabolism , Cell Wall/metabolism , Cellulose/metabolism , Water/metabolism
20.
Pulmonology ; 2024 Feb 02.
Article in English | MEDLINE | ID: mdl-38309995

ABSTRACT

INTRODUCTION AND OBJECTIVES: Hypersensitivity pneumonitis (HP) is an interstitial lung disease with diverse clinical features that can present a fibrotic phenotype similar to idiopathic pulmonary fibrosis (IPF) in genetically predisposed individuals. While several single nucleotide polymorphisms (SNPs) have been associated with IPF, the genetic factors contributing to fibrotic HP (fHP) remain poorly understood. This study investigated the association of MUC5B and TOLLIP variants with susceptibility, clinical presentation and survival in Portuguese patients with fHP. MATERIAL AND METHODS: A case-control study was undertaken with 97 fHP patients and 112 controls. Six SNPs residing in the MUC5B and TOLLIP genes and their haplotypes were analyzed. Associations with risk, survival, and clinical, radiographic, and pathological features of fHP were probed through comparisons among patients and controls. RESULTS: MUC5B rs35705950 and three neighboring TOLLIP variants (rs3750920, rs111521887, and rs5743894) were associated with increased susceptibility to fHP. Minor allele frequencies were greater among fHP patients than in controls (40.7% vs 12.1%, P<0.0001; 52.6% vs 40.2%, P = 0.011; 22.7% vs 13.4%, P = 0.013; and 23.2% vs 12.9%, P = 0.006, respectively). Haplotypes formed by these variants were also linked to fHP susceptibility. Moreover, carriers of a specific haplotype (G-T-G-C) had a significant decrease in survival (adjusted hazard ratio 6.92, 95% CI 1.73-27.64, P = 0.006). Additional associations were found between TOLLIP rs111521887 and rs5743894 variants and decreased lung function at baseline, and the MUC5B SNP and radiographic features, further highlighting the influence of genetic factors in fHP. CONCLUSION: These findings suggest that TOLLIP and MUC5B variants and haplotypes may serve as valuable tools for risk assessment and prognosis in fibrotic hypersensitivity pneumonitis, potentially contributing to its patient stratification, and offer insights into the genetic factors influencing the clinical course of the condition.

SELECTION OF CITATIONS
SEARCH DETAIL
...