Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 704
Filter
Add more filters

Country/Region as subject
Publication year range
1.
Nature ; 601(7892): 205-210, 2022 01.
Article in English | MEDLINE | ID: mdl-35022592

ABSTRACT

Fermi liquid theory forms the basis for our understanding of the majority of metals: their resistivity arises from the scattering of well defined quasiparticles at a rate where, in the low-temperature limit, the inverse of the characteristic time scale is proportional to the square of the temperature. However, various quantum materials1-15-notably high-temperature superconductors1-10-exhibit strange-metallic behaviour with a linear scattering rate in temperature, deviating from this central paradigm. Here we show the unexpected signatures of strange metallicity in a bosonic system for which the quasiparticle concept does not apply. Our nanopatterned YBa2Cu3O7-δ (YBCO) film arrays reveal linear-in-temperature and linear-in-magnetic field resistance over extended temperature and magnetic field ranges. Notably, below the onset temperature at which Cooper pairs form, the low-field magnetoresistance oscillates with a period dictated by the superconducting flux quantum, h/2e (e, electron charge; h, Planck's constant). Simultaneously, the Hall coefficient drops and vanishes within the measurement resolution with decreasing temperature, indicating that Cooper pairs instead of single electrons dominate the transport process. Moreover, the characteristic time scale τ in this bosonic system follows a scale-invariant relation without an intrinsic energy scale: h/τ ≈ a(kBT + γµBB), where h is the reduced Planck's constant, a is of order unity7,8,11,12, kB is Boltzmann's constant, T is temperature, µB is the Bohr magneton and γ ≈ 2. By extending the reach of strange-metal phenomenology to a bosonic system, our results suggest that there is a fundamental principle governing their transport that transcends particle statistics.


Subject(s)
Electrons , Superconductivity , Magnetic Fields , Metals , Temperature
2.
Nature ; 608(7922): 413-420, 2022 08.
Article in English | MEDLINE | ID: mdl-35922515

ABSTRACT

High cholesterol is a major risk factor for cardiovascular disease1. Currently, no drug lowers cholesterol through directly promoting cholesterol excretion. Human genetic studies have identified that the loss-of-function Asialoglycoprotein receptor 1 (ASGR1) variants associate with low cholesterol and a reduced risk of cardiovascular disease2. ASGR1 is exclusively expressed in liver and mediates internalization and lysosomal degradation of blood asialoglycoproteins3. The mechanism by which ASGR1 affects cholesterol metabolism is unknown. Here, we find that Asgr1 deficiency decreases lipid levels in serum and liver by stabilizing LXRα. LXRα upregulates ABCA1 and ABCG5/G8, which promotes cholesterol transport to high-density lipoprotein and excretion to bile and faeces4, respectively. ASGR1 deficiency blocks endocytosis and lysosomal degradation of glycoproteins, reduces amino-acid levels in lysosomes, and thereby inhibits mTORC1 and activates AMPK. On one hand, AMPK increases LXRα by decreasing its ubiquitin ligases BRCA1/BARD1. On the other hand, AMPK suppresses SREBP1 that controls lipogenesis. Anti-ASGR1 neutralizing antibody lowers lipid levels by increasing cholesterol excretion, and shows synergistic beneficial effects with atorvastatin or ezetimibe, two widely used hypocholesterolaemic drugs. In summary, this study demonstrates that targeting ASGR1 upregulates LXRα, ABCA1 and ABCG5/G8, inhibits SREBP1 and lipogenesis, and therefore promotes cholesterol excretion and decreases lipid levels.


Subject(s)
Asialoglycoprotein Receptor , Cholesterol , Lipid Metabolism , AMP-Activated Protein Kinases/metabolism , ATP Binding Cassette Transporter 1 , ATP Binding Cassette Transporter, Subfamily G, Member 5 , ATP Binding Cassette Transporter, Subfamily G, Member 8 , Asialoglycoprotein Receptor/antagonists & inhibitors , Asialoglycoprotein Receptor/deficiency , Asialoglycoprotein Receptor/genetics , Asialoglycoprotein Receptor/metabolism , Asialoglycoproteins/metabolism , Atorvastatin/pharmacology , BRCA1 Protein , Cardiovascular Diseases/genetics , Cardiovascular Diseases/metabolism , Cholesterol/metabolism , Drug Synergism , Endocytosis , Ezetimibe/pharmacology , Humans , Lipids/analysis , Lipids/blood , Liver/metabolism , Liver X Receptors/metabolism , Lysosomes/metabolism , Mechanistic Target of Rapamycin Complex 1/antagonists & inhibitors , Sterol Regulatory Element Binding Protein 1 , Ubiquitin-Protein Ligases/metabolism
3.
EMBO J ; 42(3): e111513, 2023 02 01.
Article in English | MEDLINE | ID: mdl-36524353

ABSTRACT

Hedgehog (Hh) signaling pathway plays a pivotal role in embryonic development. Hh binding to Patched1 (PTCH1) derepresses Smoothened (SMO), thereby activating the downstream signal transduction. Covalent SMO modification by cholesterol in its cysteine-rich domain (CRD) is essential for SMO function. SMO cholesterylation is a calcium-accelerated autoprocessing reaction, and STIM1-ORAI1-mediated store-operated calcium entry promotes cholesterylation and activation of endosome-localized SMO. However, it is unknown whether the Hh-PTCH1 interplay regulates the activity of the endoplasmic reticulum (ER)-localized SMO. Here, we found that PTCH1 inhibited the COPII-dependent export of SMO from the ER, whereas Hh promoted this process. The RRxWxR amino acid motif in the cytosolic tail of SMO was essential for COPII recognition, ciliary localization, and signal transduction activity. Hh and PTCH1 regulated cholesterol modification of the ER-localized SMO, and SMO cholesterylation accelerated its exit from ER. The GRAMD1/ASTER sterol transport proteins facilitated cholesterol transfer to ER from PM, resulting in increased SMO cholesterylation and enhanced Hh signaling. Collectively, we reveal a regulatory role of GRAMD-mediated cholesterol transport in ER-resident SMO maturation and Hh signaling.


Subject(s)
Calcium , Hedgehog Proteins , Biological Transport , Calcium/metabolism , Cholesterol/metabolism , Hedgehog Proteins/genetics , Hedgehog Proteins/metabolism , Receptors, G-Protein-Coupled/metabolism , Signal Transduction/physiology , Smoothened Receptor/genetics , Smoothened Receptor/metabolism , Membrane Proteins/metabolism
4.
Proc Natl Acad Sci U S A ; 121(13): e2315531121, 2024 Mar 26.
Article in English | MEDLINE | ID: mdl-38498704

ABSTRACT

Mating type (sex) plays a crucial role in regulating sexual reproduction in most extant eukaryotes. One of the functions of mating types is ensuring self-incompatibility to some extent, thereby promoting genetic diversity. However, heterothallic mating is not always the best mating strategy. For example, in low-density populations or specific environments, such as parasitic ones, species may need to increase the ratio of potential mating partners. Consequently, many species allow homothallic selfing (i.e., self-fertility or intraclonal mating). Throughout the extensive evolutionary history of species, changes in environmental conditions have influenced mating strategies back and forth. However, the mechanisms through which mating-type recognition regulates sexual reproduction and the dynamics of mating strategy throughout evolution remain poorly understood. In this study, we show that the Cip1 protein is responsible for coupling sexual reproduction initiation to mating-type recognition in the protozoal eukaryote Tetrahymena thermophila. Deletion of the Cip1 protein leads to the loss of the selfing-avoidance function of mating-type recognition, resulting in selfing without mating-type recognition. Further experiments revealed that Cip1 is a regulatory subunit of the Cdk19-Cyc9 complex, which controls the initiation of sexual reproduction. These results reveal a mechanism that regulates the choice between mating and selfing. This mechanism also contributes to the debate about the ancestral state of sexual reproduction.


Subject(s)
Fertility , Reproduction , Reproduction/genetics , Eukaryota/genetics , Genes, Mating Type, Fungal
5.
Genes Dev ; 33(5-6): 348-364, 2019 03 01.
Article in English | MEDLINE | ID: mdl-30808657

ABSTRACT

RNAi and Polycomb repression play evolutionarily conserved and often coordinated roles in transcriptional silencing. Here, we show that, in the protozoan Tetrahymena thermophila, germline-specific internally eliminated sequences (IESs)-many related to transposable elements (TEs)-become transcriptionally activated in mutants deficient in the RNAi-dependent Polycomb repression pathway. Germline TE mobilization also dramatically increases in these mutants. The transition from noncoding RNA (ncRNA) to mRNA production accompanies transcriptional activation of TE-related sequences and vice versa for transcriptional silencing. The balance between ncRNA and mRNA production is potentially affected by cotranscriptional processing as well as RNAi and Polycomb repression. We posit that interplay between RNAi and Polycomb repression is a widely conserved phenomenon, whose ancestral role is epigenetic silencing of TEs.


Subject(s)
DNA Transposable Elements/genetics , Polycomb-Group Proteins/genetics , Protozoan Proteins/genetics , RNA Interference , Tetrahymena thermophila/genetics , Transcriptional Activation/genetics , Epigenesis, Genetic , Gene Silencing , Mutation , RNA, Messenger/genetics , RNA, Untranslated/genetics
6.
Nature ; 588(7838): 479-484, 2020 12.
Article in English | MEDLINE | ID: mdl-33177714

ABSTRACT

Cholesterol is an essential lipid and its synthesis is nutritionally and energetically costly1,2. In mammals, cholesterol biosynthesis increases after feeding and is inhibited under fasting conditions3. However, the regulatory mechanisms of cholesterol biosynthesis at the fasting-feeding transition remain poorly understood. Here we show that the deubiquitylase ubiquitin-specific peptidase 20 (USP20) stabilizes HMG-CoA reductase (HMGCR), the rate-limiting enzyme in the cholesterol biosynthetic pathway, in the feeding state. The post-prandial increase in insulin and glucose concentration stimulates mTORC1 to phosphorylate USP20 at S132 and S134; USP20 is recruited to the HMGCR complex and antagonizes its degradation. The feeding-induced stabilization of HMGCR is abolished in mice with liver-specific Usp20 deletion and in USP20(S132A/S134A) knock-in mice. Genetic deletion or pharmacological inhibition of USP20 markedly decreases diet-induced body weight gain, reduces lipid levels in the serum and liver, improves insulin sensitivity and increases energy expenditure. These metabolic changes are reversed by expression of the constitutively stable HMGCR(K248R). This study reveals an unexpected regulatory axis from mTORC1 to HMGCR via USP20 phosphorylation and suggests that inhibitors of USP20 could be used to lower cholesterol levels to treat metabolic diseases including hyperlipidaemia, liver steatosis, obesity and diabetes.


Subject(s)
Cholesterol/biosynthesis , Eating/physiology , Hydroxymethylglutaryl CoA Reductases/metabolism , Mechanistic Target of Rapamycin Complex 1/metabolism , Ubiquitin Thiolesterase/metabolism , Animals , Cell Line , Glucose/metabolism , Humans , Insulin/metabolism , Liver/metabolism , Male , Metabolic Diseases/genetics , Metabolic Diseases/metabolism , Metabolism/genetics , Mice , Mice, Inbred C57BL , Phosphorylation , Phosphoserine/metabolism , Ubiquitin Thiolesterase/antagonists & inhibitors , Ubiquitin Thiolesterase/chemistry , Ubiquitin Thiolesterase/deficiency , Ubiquitination , Weight Gain
7.
Nucleic Acids Res ; 52(D1): D747-D755, 2024 Jan 05.
Article in English | MEDLINE | ID: mdl-37930867

ABSTRACT

Protists, a highly diverse group of microscopic eukaryotic organisms distinct from fungi, animals and plants, exert crucial roles within the earth's biosphere. However, the genomes of only a small fraction of known protist species have been published and made publicly accessible. To address this constraint, the Protist 10 000 Genomes Project (P10K) was initiated, implementing a specialized pipeline for single-cell genome/transcriptome assembly, decontamination and annotation of protists. The resultant P10K database (https://ngdc.cncb.ac.cn/p10k/) serves as a comprehensive platform, collating and disseminating genome sequences and annotations from diverse protist groups. Currently, the P10K database has incorporated 2959 genomes and transcriptomes, including 1101 newly sequenced datasets by P10K and 1858 publicly available datasets. Notably, it covers 45% of the protist orders, with a significant representation (53% coverage) of ciliates, featuring nearly a thousand genomes/transcriptomes. Intriguingly, analysis of the unique codon table usage among ciliates has revealed differences compared to the NCBI taxonomy system, suggesting a need to revise the codon tables used for these species. Collectively, the P10K database serves as a valuable repository of genetic resources for protist research and aims to expand its collection by incorporating more sequenced data and advanced analysis tools to benefit protist studies worldwide.


Subject(s)
Databases, Genetic , Eukaryota , Fungi , Genome , Animals , Codon , Eukaryota/genetics , Fungi/genetics , Plants/genetics
8.
J Proteome Res ; 23(5): 1689-1701, 2024 May 03.
Article in English | MEDLINE | ID: mdl-38565891

ABSTRACT

Cyanobacteria are the oldest prokaryotic photoautotrophic microorganisms and have evolved complicated post-translational modification (PTM) machinery to respond to environmental stress. Lysine 2-hydroxyisobutyrylation (Khib) is a newly identified PTM that is reported to play important roles in diverse biological processes, however, its distribution and function in cyanobacteria have not been reported. Here, we performed the first systematic studies of Khib in a model cyanobacterium Synechococcus sp. strain PCC 7002 (Syn7002) using peptide prefractionation, pan-Khib antibody enrichment, and high-accuracy mass spectrometry (MS) analysis. A total of 1875 high-confidence Khib sites on 618 proteins were identified, and a large proportion of Khib sites are present on proteins in the cellular metabolism, protein synthesis, and photosynthesis pathways. Using site-directed mutagenesis and functional studies, we showed that Khib of glutaredoxin (Grx) affects the efficiency of the PS II reaction center and H2O2 resistance in Syn7002. Together, this study provides novel insights into the functions of Khib in cyanobacteria and suggests that reversible Khib may influence the stress response and photosynthesis in both cyanobacteria and plants.


Subject(s)
Lysine , Protein Processing, Post-Translational , Synechococcus , Lysine/metabolism , Synechococcus/metabolism , Synechococcus/genetics , Bacterial Proteins/metabolism , Bacterial Proteins/genetics , Hydrogen Peroxide/metabolism , Glutaredoxins/metabolism , Glutaredoxins/genetics , Photosystem II Protein Complex/metabolism , Photosystem II Protein Complex/genetics , Mutagenesis, Site-Directed , Photosynthesis , Cyanobacteria/metabolism , Cyanobacteria/genetics , Mass Spectrometry
9.
Oncologist ; 2024 Jul 11.
Article in English | MEDLINE | ID: mdl-38990195

ABSTRACT

BACKGROUND: Encouraging antitumor activity of nab-paclitaxel plus S-1 (AS) has been shown in several small-scale studies. This study compared the efficacy and safety of AS versus standard-of-care nab-paclitaxel plus gemcitabine (AG) as a first-line treatment for advanced pancreatic cancer (PC). METHODS: In this multicenter, randomized, phase II trial, eligible patients with unresectable, locally advanced, or metastatic PC were recruited and randomly assigned (1:1) to receive AS (nab-paclitaxel 125 mg/m2 on days 1 and 8; S-1 twice daily on days 1 through 14) or AG (nab-paclitaxel 125 mg/m2 on days 1 and 8; gemcitabine 1000 mg/m2 on days 1 and 8) for 6 cycles. The primary endpoint was progression-free survival (PFS). RESULTS: Between July 16, 2019, and September 9, 2022, 62 patients (AS, n = 32; AG, n = 30) were treated and evaluated. With a median follow-up of 8.36 months at preplanned interim analysis (data cutoff, March 24, 2023), the median PFS (8.48 vs 4.47 months; hazard ratio [HR], 0.402; P = .002) and overall survival (OS; 13.73 vs 9.59 months; HR, 0.226; P < .001) in the AS group were significantly longer compared to the AG group. More patients had objective response in the AS group than AG group (37.50% vs 6.67%; P = .005). The most common grade 3-4 adverse events were neutropenia and leucopenia in both groups, and gamma glutamyl transferase increase was observed only in the AG group. CONCLUSION: The first-line AS regimen significantly extended both PFS and OS of Chinese patients with advanced PC when compared with the AG regimen, with a comparable safety profile. (ClinicalTrials.gov Identifier: NCT03636308).

10.
Small ; : e2312230, 2024 Mar 22.
Article in English | MEDLINE | ID: mdl-38516959

ABSTRACT

All inorganic CsPbI2Br perovskite (AIP) has attracted great attention due to its excellent resistance against thermal stress as well as the remarkable capability to deliver high-voltage output. However, CsPbI2Br perovskite solar cells (PeSCs) still encounter critical challenges in attaining both high efficiency and mechanical stability for commercial applications. In this work, formamidine disulfide dihydrochloride (FADD) modified ZnO electron transport layer (ETL) has been developed for fabricating inverted devices on either rigid or flexible substrate. It is found that the FADD modification leads to efficient defects passivation, thereby significantly reducing charge recombination at the AIP/ETL interface. As a result, rigid PeSCs (r-PeSCs) deliver an enhanced efficiency of 16.05% and improved long-term thermal stability. Moreover, the introduced FADD can regulate the Young's modulus (or Derjaguin-Muller-Toporov (DMT) modilus) of ZnO ETL and dissipate stress concentration at the AIP/ETL interface, effectively restraining the crack generation and improving the mechanical stability of PeSCs. The flexible PeSCs (f-PeSCs) exhibit one of the best performances so far reported with excellent stability against 6000 bending cycles at a curvature radius of 5 mm. This work thus provides an effective strategy to simultaneously improve the photovoltaic performance and mechanical stability.

11.
Mol Phylogenet Evol ; 197: 108110, 2024 Aug.
Article in English | MEDLINE | ID: mdl-38768875

ABSTRACT

Ciliophora, an exceptionally diverse lineage of unicellular eukaryotes, exhibits a remarkable range of species richness across classes in the ciliate Tree of Life. In this study, we have acquired transcriptome and genome data from 40 representative species in seven ciliate classes. Utilizing 247 genes and 105 taxa, we devised a comprehensive phylogenomic tree for Ciliophora, encompassing over 60 % of orders and constituting the most extensive dataset of ciliate species to date. We established a robust phylogenetic framework that encompasses ambiguous taxa and the major classes within the phylum. Our findings support the monophyly of each of two subphyla (Postciliodesmatophora and Intramacronucleata), along with three subclades (Protocruzia, CONTHREEP, and SAPML) nested within Intramacronucleata, and elucidate evolutionary positions among the major classes within the phylum. Drawing on the robust ciliate Tree of Life and three constraints, we estimated the radiation of Ciliophora around 1175 Ma during the middle of the Proterozoic Eon, and most of the ciliate classes diverged from their sister lineage during the latter half of this period. Additionally, based on the time-calibrated tree and species richness pattern, we investigated net diversification rates of Ciliophora and its classes. The global net diversification rate for Ciliophora was estimated at 0.004979 species/Ma. Heterogeneity in net diversification rates was evident at the class level, with faster rates observed in Oligohymenophorea and Spirotrichea than other classes within the subclades CONTHREEP and SAPML, respectively. Notably, our analysis suggests that variations in net diversification rates, rather than clade ages, appear to contribute to the differences in species richness in Ciliophora at the class level.


Subject(s)
Ciliophora , Phylogeny , Ciliophora/genetics , Ciliophora/classification , Transcriptome , Evolution, Molecular , Genetic Speciation
12.
Environ Res ; 252(Pt 4): 119036, 2024 Jul 01.
Article in English | MEDLINE | ID: mdl-38701889

ABSTRACT

An increasing number of per- and polyfluoroalkyl substances (PFAS) exposed to the environment may pose a threat to organisms and human beings. However, there is a lack of simulations comprehensively addressing and comparing the bioaccumulation of PFAS across all three major exposure routes (oral, inhalation, and dermal), especially for dermal uptake. In this study, we proposed a physiologically based kinetic (PBK) model for PFAS, aiming to predict bioaccumulation factors (BAF) in fish by considering these diverse exposure routes. 15 PFAS were used for model validation, and 11 PFAS from Taihu Lake were used for exposure contribution modeling. Approximately 64% of estimations fell within 10-fold model bias from measurements in Taihu Lake, underscoring the potential efficacy of the developed PBK model in predicting BAFs for fish. The dermal route emerges as a contributor to short-chain PFAS exposure. For example, it ranged widely from 46% to 75% (mean) for all modeling short-chain PFAS (C6-C7) in Taihu Lake. It indicated the criticality of considering dermal exposure for PFAS in fish, highlighting a gap in field studies to unravel cutaneous intake mechanisms and contributions. For longer carbon chains of PFAS (C8-C12), dermal exposure accounted for 2%-27% for all species of aquatic organisms. The fish's lipid fraction and water content played a significant role in the contribution of PFAS intake through cutaneous exposure and inhalation. Kow had a significant positive correlation with skin intake rate (p < 0.05) and gill intake rate (p < 0.001), while having a significant negative correlation with skin intake (p < 0.05) and skin intake contribution (p < 0.001). Based on the proposed modeling approach, we have introduced a simulation spreadsheet for projecting PFAS BAFs in fish tissues, hopefully broadening the predictive operational tool for a variety of chemical species.


Subject(s)
Fishes , Fluorocarbons , Water Pollutants, Chemical , Animals , Fishes/metabolism , Water Pollutants, Chemical/analysis , Water Pollutants, Chemical/metabolism , Fluorocarbons/metabolism , Fluorocarbons/analysis , Fluorocarbons/pharmacokinetics , Bioaccumulation , Models, Biological , Lakes/chemistry , Environmental Monitoring/methods
13.
Mol Cell ; 62(2): 222-236, 2016 Apr 21.
Article in English | MEDLINE | ID: mdl-27151440

ABSTRACT

PRDM16 is a transcription co-factor that plays critical roles in development of brown adipose tissue, as well as maintenance of adult hematopoietic and neural stem cells. Here we report that PRDM16 is a histone H3K4 methyltransferase on chromatin. Mutation in the N-terminal PR domain of PRDM16 abolishes the intrinsic enzymatic activity of PRDM16. We show that the methyltransferase activity of PRDM16 is required for specific suppression of MLL fusion protein-induced leukemogenesis both in vitro and in vivo. Mechanistic studies show that PRDM16 directly activates the SNAG family transcription factor Gfi1b, which in turn downregulates the HOXA gene cluster. Knockdown Gfi1b represses PRDM16-mediated tumor suppression, while Gfi1b overexpression mimics PRDM16 overexpression. In further support of the tumor suppressor function of PRDM16, silencing PRDM16 by DNA methylation is concomitant with MLL-AF9-induced leukemic transformation. Taken together, our study reveals a previously uncharacterized function of PRDM16 that depends on its PR domain activity.

14.
Nucleic Acids Res ; 50(19): 11255-11272, 2022 10 28.
Article in English | MEDLINE | ID: mdl-36273819

ABSTRACT

Understanding the molecular and cellular mechanisms of human primordial germ cells (hPGCs) is essential in studying infertility and germ cell tumorigenesis. Many RNA-binding proteins (RBPs) and non-coding RNAs are specifically expressed and functional during hPGC developments. However, the roles and regulatory mechanisms of these RBPs and non-coding RNAs, such as microRNAs (miRNAs), in hPGCs remain elusive. In this study, we reported a new regulatory function of DAZL, a germ cell-specific RBP, in miRNA biogenesis and cell proliferation. First, DAZL co-localized with miRNA let-7a in human PGCs and up-regulated the levels of >100 mature miRNAs, including eight out of nine let-7 family, miR21, miR22, miR125, miR10 and miR199. Purified DAZL directly bound to the loops of precursor miRNAs with sequence specificity of GUU. The binding of DAZL to the precursor miRNA increased the maturation of miRNA by enhancing the cleavage activity of DICER. Furthermore, cell proliferation assay and cell cycle analysis confirmed that DAZL inhibited the proliferation of in vitro PGCs by promoting the maturation of these miRNAs. Evidently, the mature miRNAs up-regulated by DAZL silenced cell proliferation regulators including TRIM71. Moreover, DAZL inhibited germline tumor cell proliferation and teratoma formation. These results demonstrate that DAZL regulates hPGC proliferation by enhancing miRNA processing.


Subject(s)
MicroRNAs , Humans , Cell Proliferation/genetics , Germ Cells/metabolism , MicroRNAs/genetics , MicroRNAs/metabolism , RNA-Binding Proteins/metabolism , Tripartite Motif Proteins , Ubiquitin-Protein Ligases/metabolism
15.
BMC Biol ; 21(1): 46, 2023 02 28.
Article in English | MEDLINE | ID: mdl-36855107

ABSTRACT

BACKGROUND: Immune cells that infiltrate lesions are important for atherosclerosis progression and immunotherapies. This study was aimed at gaining important new insights into the heterogeneity of these cells by integrating the sequencing results of multiple samples and using an enhanced single-cell sequencing workflow to overcome the limitations of a single study. RESULTS: Integrative analyses identified 28 distinct subpopulations based on gene expression profiles. Further analysis demonstrated that these cells manifested high heterogeneity at the levels of tissue preferences, genetic perturbations, functional variations, immune dynamics, transcriptional regulators, metabolic changes, and communication patterns. Of the T cells, interferon-induced CD8+ T cells were involved in the progression of atherosclerosis. In contrast, proinflammatory CD4+ CD28null T cells predicted a poor outcome in atherosclerosis. Notably, we identified two subpopulations of foamy macrophages that exhibit contrasting phenotypes. Among them, TREM2- SPP1+ foamy macrophages were preferentially distributed in the hypoxic core of plaques. These glycolytic metabolism-enriched cells, with impaired cholesterol metabolism and robust pro-angiogenic capacity, were phenotypically regulated by CSF1 secreted by co-localised mast cells. Moreover, combined with deconvolution of the bulk datasets, we revealed that these dysfunctional cells had a higher proportion of ruptured and haemorrhagic lesions and were significantly associated with poor atherosclerosis prognoses. CONCLUSIONS: We systematically explored atherosclerotic immune heterogeneity and identified cell populations underlying atherosclerosis progression and poor prognosis, which may be valuable for developing new and precise immunotherapies.


Subject(s)
Atherosclerosis , CD8-Positive T-Lymphocytes , Immunotherapy , Humans , Atherosclerosis/genetics , Atherosclerosis/therapy , Biological Transport
16.
J Liposome Res ; : 1-13, 2024 May 07.
Article in English | MEDLINE | ID: mdl-38712581

ABSTRACT

Liposomes are small spherical vesicles composed of phospholipid bilayers capable of encapsulating a variety of ingredients, including water- and oil-soluble compound, which are one of the most commonly used piggybacking and delivery techniques for many active ingredients and different compounds in biology, medicine and cosmetics. With the increasing number of active cosmetic ingredients, the concomitant challenge is to effectively protect, transport, and utilize these substances in a judicious manner. Many cosmetic ingredients are ineffective both topically and systemically when applied to the skin, thus changing the method of delivery and interaction with the skin of the active ingredients is a crucial step toward improving their effectiveness. Liposomes can improve the delivery of active ingredients to the skin, enhance their stability, and ultimately, improve the efficacy of cosmetics and and pharmaceuticals. In this review, we summarized the basic properties of liposomes and their recent advances of functionalities in cosmetics and and pharmaceuticals. Also, the current state of the art in the field is discussed and the prospects for future research areas are highlighted. We hope that this review will provide ideas and inspiration on the application and development of cosmetics and pharmaceuticals.

17.
Nurs Crit Care ; 2024 Jun 04.
Article in English | MEDLINE | ID: mdl-38837818

ABSTRACT

BACKGROUND: Extracorporeal membrane oxygenation (ECMO) can be a life-saving treatment for patients requiring advanced cardiopulmonary support. Several ECMO centres offer interhospital transport (ECMO IHT) services that involve establishing ECMO teams to initiate ECMO at referring hospitals and then transfer patients to ECMO centres. ECMO IHT is often high risk and complex. Understanding the experience of transport team members is crucial to ensure patient safety and promote quality improvement. AIM: To explore the experiences of transport teams performing ECMO IHT. STUDY DESIGN: A descriptive qualitative methodology was adopted. RESULTS: Thirteen health care professionals who have performed ECMO IHT at a general hospital in China agreed to be interviewed and enrolled in this study. Two investigators conducted face-to-face individual interviews in September-November 2022. All interviews were audio-recorded, transcribed verbatim and analysed using inductive thematic analysis. Three main themes and nine sub-themes were developed: (1) practicing with good organizational management (conducting training programs, cultivating the spirit of good teamwork and developing a standardized transport procedure), (2) dedicated to ensuring patient safety (adequate preparation and regular checking to reduce risk, accurate evaluation to avoid futility and maintaining communication to increase safety) and (3) having confidence despite being uneasy (feeling stressed is common, facing insecurity in transport settings and gaining confidence through practice). CONCLUSIONS: Health care professionals must adequately prepare and assess ECMO IHT to ensure patient safety. Supportive measures should be taken to ensure team members' health and improve patient safety. Good communication and teamwork could improve this challenging task. Further research is required for training programs and establishing standardized transport procedures. RELEVANCE TO CLINICAL PRACTICE: This study presents multi-professional perspectives on the experience of performing ECMO IHT to help management identify what needs to be further developed. With the increasing number of ECMO IHT, promoting its standardization is warranted.

18.
Actas Esp Psiquiatr ; 52(1): 28-36, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38454900

ABSTRACT

BACKGROUND: Depressive disorder is a chronic mental illness characterized by persistent low mood as its primary clinical symptom. Currently, psychotherapy and drug therapy stand as the primary treatment modalities in clinical practice, offering a certain degree of relief from negative emotions for patients. Nevertheless, sole reliance on drug therapy exhibits a delayed impact on neurotransmitters, and long-term usage often results in adverse side effects such as nausea, drowsiness, and constipation, significantly impeding medication adherence. This study aims to investigate the impact of combining transcranial magnetic stimulation with sertraline on the cognitive level, inflammatory response, and neurological function in patients with depressive disorder who engage in non-suicidal self-injury (NSSI) behavior. METHODS: A total of 130 depressive patients NSSI behavior, who were admitted to our hospital from December 2020 to February 2023, were selected as the subjects for this research. The single-group (65 cases) received treatment with oral sertraline hydrochloride tablets, while the combination group (65 cases) underwent repetitive transcranial magnetic stimulation (rTMS) in conjunction with sertraline. The Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) was utilized to assess the depression status and cognitive function levels of both groups. Additionally, the enzyme-linked immunosorbent assay (ELISA) was employed to measure serum levels of inflammatory factors, including tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß), and interleukin-6 (IL-6). Furthermore, serum levels of neurotransmitters (norepinephrine (NE), dopamine (DA), 5-hydroxytryptamine (5-HT)) and neuro-cytokines (brain-derived neurotrophic factor (BDNF), nerve growth factor (NGF), glial fibrillary acidic protein (GFAP)) were assessed. The clinical effects of the interventions on both groups were then evaluated. RESULTS: Following the treatment, the combination group exhibited significantly higher levels of immediate memory, delayed memory, attention, visual function, and language function compared to the single group, with statistically significant differences (p < 0.05). Additionally, the serum levels of TNF-α, IL-1ß, IL-6, and GFAP in the combination group were lower than those in the single group, while the levels of BDNF and NGF were higher in the combination group compared to the single group. These differences were also statistically significant (p < 0.05). Simultaneously, the total clinical effective rate in the combination group reached 95.38%, surpassing the 84.61% observed in the single group, and the disparity between the two groups was statistically significant (p < 0.05). CONCLUSIONS: The combined use of rTMS and sertraline in treating patients with depressive disorder exhibiting NSSI behavior has proven to be effective in enhancing cognitive function, mitigating inflammatory responses, and elevating levels of neurotransmitters and nerve cytokines in the patients.


Subject(s)
Depressive Disorder , Self-Injurious Behavior , Humans , Sertraline/therapeutic use , Transcranial Magnetic Stimulation/methods , Brain-Derived Neurotrophic Factor/metabolism , Tumor Necrosis Factor-alpha , Interleukin-6 , Nerve Growth Factor , Cytokines/metabolism , Cognition , Neurotransmitter Agents
19.
Circulation ; 145(9): 675-687, 2022 03.
Article in English | MEDLINE | ID: mdl-35189703

ABSTRACT

BACKGROUND: High blood cholesterol accelerates the progression of atherosclerosis, which is an asymptomatic process lasting for decades. Rupture of atherosclerotic plaques induces thrombosis, which results in myocardial infarction or stroke. Lowering cholesterol levels is beneficial for preventing atherosclerotic cardiovascular disease. METHODS: Low-density lipoprotein (LDL) receptor (LDLR) was used as bait to identify its binding proteins in the plasma, and the coagulation factor prekallikrein (PK; encoded by the KLKB1 gene) was revealed. The correlation between serum PK protein content and lipid levels in young Chinese Han people was then analyzed. To investigate the effects of PK ablation on LDLR and lipid levels in vivo, we genetically deleted Klkb1 in hamsters and heterozygous Ldlr knockout mice and knocked down Klkb1 using adeno-associated virus-mediated shRNA in rats. The additive effect of PK and proprotein convertase subtilisin/kexin 9 inhibition also was evaluated. In addition, we applied the anti-PK neutralizing antibody that blocked the PK and LDLR interaction in mice. Mice lacking both PK and apolipoprotein e (Klkb1-/-Apoe-/-) were generated to assess the role of PK in atherosclerosis. RESULTS: PK directly bound LDLR and induced its lysosomal degradation. The serum PK concentrations positively correlated with LDL cholesterol levels in 198 young Chinese Han adults. Genetic depletion of Klkb1 increased hepatic LDLR and decreased circulating cholesterol in multiple rodent models. Inhibition of proprotein convertase subtilisin/kexin 9 with evolocumab further decreased plasma LDL cholesterol levels in Klkb1-deficient hamsters. The anti-PK neutralizing antibody could similarly lower plasma lipids through upregulating hepatic LDLR. Ablation of Klkb1 slowed the progression of atherosclerosis in mice on Apoe-deficient background. CONCLUSIONS: PK regulates circulating cholesterol levels through binding to LDLR and inducing its lysosomal degradation. Ablation of PK stabilizes LDLR, decreases LDL cholesterol, and prevents atherosclerotic plaque development. This study suggests that PK is a promising therapeutic target to treat atherosclerotic cardiovascular disease.


Subject(s)
Atherosclerosis/metabolism , Atherosclerosis/prevention & control , Cholesterol, LDL/metabolism , Plaque, Atherosclerotic/metabolism , Plaque, Atherosclerotic/prevention & control , Prekallikrein/deficiency , Receptors, LDL/metabolism , Animals , Atherosclerosis/genetics , Cholesterol, LDL/genetics , Lysosomes/genetics , Lysosomes/metabolism , Mice , Mice, Knockout , Plaque, Atherosclerotic/genetics , Prekallikrein/metabolism , Proteolysis , Receptors, LDL/genetics
20.
Small ; 19(38): e2301433, 2023 Sep.
Article in English | MEDLINE | ID: mdl-37263991

ABSTRACT

Lithium metal batteries are intensively studied due to the potential to bring up breakthroughs in high energy density devices. However, the inevitable growth of dendrites will cause the rapid failure of battery especially under high current density. Herein, the utilization of tetrachloroethylene (C2 Cl4 ) is reported as the electrolyte additive to induce the formation of the LiCl-rich solid electrolyte interphase (SEI). Because of the lower Li ion diffusion barrier of LiCl, such SEI layer can supply sufficient pathway for rapid Li ion transport, alleviate the concentration polarization at the interface and inhibit the growth of Li dendrites. Meanwhile, the C2 Cl4 can be continuously replenished during the cycle to ensure the stability of the SEI layer. With the aid of C2 Cl4 -based electrolyte, the Li metal electrodes can maintain stable for >300 h under high current density of 50 mA cm-2 with areal capacity of 5 mAh cm-2 , broadening the compatibility of lithium metal anode toward practical application scenarios.

SELECTION OF CITATIONS
SEARCH DETAIL