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1.
Cell ; 185(8): 1325-1345.e22, 2022 04 14.
Article in English | MEDLINE | ID: mdl-35366418

ABSTRACT

Protein aggregation is a hallmark of multiple human pathologies. Autophagy selectively degrades protein aggregates via aggrephagy. How selectivity is achieved has been elusive. Here, we identify the chaperonin subunit CCT2 as an autophagy receptor regulating the clearance of aggregation-prone proteins in the cell and the mouse brain. CCT2 associates with aggregation-prone proteins independent of cargo ubiquitination and interacts with autophagosome marker ATG8s through a non-classical VLIR motif. In addition, CCT2 regulates aggrephagy independently of the ubiquitin-binding receptors (P62, NBR1, and TAX1BP1) or chaperone-mediated autophagy. Unlike P62, NBR1, and TAX1BP1, which facilitate the clearance of protein condensates with liquidity, CCT2 specifically promotes the autophagic degradation of protein aggregates with little liquidity (solid aggregates). Furthermore, aggregation-prone protein accumulation induces the functional switch of CCT2 from a chaperone subunit to an autophagy receptor by promoting CCT2 monomer formation, which exposes the VLIR to ATG8s interaction and, therefore, enables the autophagic function.


Subject(s)
Chaperonin Containing TCP-1 , Macroautophagy , Protein Aggregates , Animals , Mice , Apoptosis Regulatory Proteins/metabolism , Autophagy/physiology , Carrier Proteins/metabolism , Chaperonin Containing TCP-1/metabolism , Sequestosome-1 Protein/metabolism
2.
EMBO J ; 42(19): e112814, 2023 10 04.
Article in English | MEDLINE | ID: mdl-37635626

ABSTRACT

The regulation of autophagy initiation is a key step in autophagosome biogenesis. However, our understanding of the molecular mechanisms underlying the stepwise assembly of ATG proteins during this process remains incomplete. The Rab GTPase Ypt1/Rab1 is recognized as an essential autophagy regulator. Here, we identify Atg23 and Atg17 as binding partners of Ypt1, with their direct interaction proving crucial for the stepwise assembly of autophagy initiation complexes. Disruption of Ypt1-Atg23 binding results in significantly reduced Atg9 interactions with Atg11, Atg13, and Atg17, thus preventing the recruitment of Atg9 vesicles to the phagophore assembly site (PAS). Likewise, Ypt1-Atg17 binding contributes to the PAS recruitment of Ypt1 and Atg1. Importantly, we found that Ypt1 is phosphorylated by TOR at the Ser174 residue. Converting this residue to alanine blocks Ypt1 phosphorylation by TOR and enhances autophagy. Conversely, the Ypt1S174D phosphorylation mimic impairs both PAS recruitment and activation of Atg1, thus inhibiting subsequent autophagy. Thus, we propose TOR-mediated Ypt1 as a multifunctional assembly factor that controls autophagy initiation via its regulation of the stepwise assembly of ATG proteins.


Subject(s)
Saccharomyces cerevisiae Proteins , Autophagy/physiology , Autophagy-Related Proteins/metabolism , Phagosomes/metabolism , Phosphorylation , Saccharomyces cerevisiae/genetics , Saccharomyces cerevisiae/metabolism , Saccharomyces cerevisiae Proteins/metabolism
3.
EMBO Rep ; 2024 Sep 25.
Article in English | MEDLINE | ID: mdl-39322741

ABSTRACT

CCT2 serves as an aggrephagy receptor that plays a crucial role in the clearance of solid aggregates, yet the underlying molecular mechanisms by which CCT2 regulates solid aggrephagy are not fully understood. Here we report that the binding of Cct2 to Atg8 is governed by two distinct regulatory mechanisms: Atg1-mediated Cct2 phosphorylation and the interaction between Cct2 and Atg11. Atg1 phosphorylates Cct2 at Ser412 and Ser470, and disruption of these phosphorylation sites impairs solid aggrephagy by hindering Cct2-Atg8 binding. Additionally, we observe that Atg11, an adaptor protein involved in selective autophagy, directly associates with Cct2 through its CC4 domain. Deficiency in this interaction significantly weakens the association of Cct2 with Atg8. The requirement of Atg1-mediated Cct2 phosphorylation and of Atg11 for CCT2-LC3C binding and subsequent aggrephagy is conserved in mammalian cells. These findings provide insights into the crucial roles of Atg1-mediated Cct2 phosphorylation and Atg11-Cct2 binding as key mediators governing the interaction between Cct2 and Atg8 during the process of solid aggrephagy.

4.
Proc Natl Acad Sci U S A ; 120(1): e2215126120, 2023 01 03.
Article in English | MEDLINE | ID: mdl-36574691

ABSTRACT

Mec1 is a DNA damage sensor, which performs an essential role in the DNA damage response pathway and glucose starvation-induced autophagy. However, the functions of Mec1 in autophagy remain unclear. In response to glucose starvation, Mec1 forms puncta, which are recruited to mitochondria through the adaptor protein Ggc1. Here, we show that Mec1 puncta also contact the phagophore assembly site (PAS) via direct binding with Atg13. Functional analysis of the Atg13-Mec1 interaction revealed two previously unrecognized protein regions, the Mec1-Binding Region (MBR) on Atg13 and the Atg13-Binding Region (ABR) on Mec1, which mediate their mutual association under glucose starvation conditions. Disruption of the MBR or ABR impairs the recruitment of Mec1 puncta and Atg13 to the PAS, consequently blocking glucose starvation-induced autophagy. Additionally, the MBR and ABR regions are also crucial for DNA damage-induced autophagy. We thus propose that Mec1 regulates glucose starvation-induced autophagy by controlling Atg13 recruitment to the PAS.


Subject(s)
Saccharomyces cerevisiae Proteins , Saccharomyces cerevisiae Proteins/genetics , Saccharomyces cerevisiae Proteins/metabolism , Saccharomyces cerevisiae/metabolism , Protein Kinases/metabolism , Glucose/metabolism , Autophagy/physiology , Autophagy-Related Proteins/genetics , Autophagy-Related Proteins/metabolism , Protein Serine-Threonine Kinases/genetics , Protein Serine-Threonine Kinases/metabolism , Intracellular Signaling Peptides and Proteins/genetics , Intracellular Signaling Peptides and Proteins/metabolism , Adaptor Proteins, Signal Transducing/genetics , Adaptor Proteins, Signal Transducing/metabolism
5.
Bioinformatics ; 40(3)2024 03 04.
Article in English | MEDLINE | ID: mdl-38449297

ABSTRACT

MOTIVATION: The advancement of structural biology has increased the requirements for researchers to quickly and efficiently visualize molecular structures in silico. Meanwhile, it is also time-consuming for structural biologists to create publication-standard figures, as no useful tools can directly generate figures from structure data. Although manual editing can ensure that figures meet the standards required for publication, it requires a deep understanding of software operations and/or program call commands. Therefore, providing interfaces based on established software instead of manual editing becomes a significant necessity. RESULTS: We developed PyMOL-PUB, based on the original design of PyMOL, to effectively create publication-quality figures from molecular structure data. It provides functions including structural alignment methods, functional coloring schemes, conformation adjustments, and layout plotting strategies. These functions allow users to easily generate high-quality figures, demonstrate structural differences, illustrate inter-molecular interactions, and predict performances of biomacromolecules. AVAILABILITY AND IMPLEMENTATION: Our tool is publicly available at https://github.com/BGI-SynBio/PyMOL-PUB.


Subject(s)
Software , Molecular Conformation
6.
Br J Cancer ; 130(5): 755-768, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38228715

ABSTRACT

BACKGROUND: Radiotherapy is a critical treatment modality for nasopharyngeal carcinoma (NPC). However, the mechanisms underlying radiation resistance and tumour recurrence in NPC remain incompletely understood. METHODS: Oxidised lipids were assessed through targeted metabolomics. Ferroptosis levels were evaluated using cell viability, clonogenic survival, lipid peroxidation, and transmission electron microscopy. We investigated the biological functions of glutathione S-transferase mu 3 (GSTM3) in cell lines and xenograft tumours. Co-immunoprecipitation, mass spectrometry, and immunofluorescence were conducted to explore the molecular mechanisms involving GSTM3. Immunohistochemistry was performed to investigate the clinical characteristics of GSTM3. RESULTS: Ionising radiation (IR) promoted lipid peroxidation and induced ferroptosis in NPC cells. GSTM3 was upregulated following IR exposure and correlated with IR-induced ferroptosis, enhancing NPC radiosensitivity in vitro and in vivo. Mechanistically, GSTM3 stabilised ubiquitin-specific peptidase 14 (USP14), thereby inhibiting the ubiquitination and subsequent degradation of fatty acid synthase (FASN). Additionally, GSTM3 interacted with glutathione peroxidase 4 (GPX4) and suppressed GPX4 expression. Combining IR treatment with ferroptosis inducers synergistically improved NPC radiosensitivity and suppressed tumour growth. Notably, a decrease in GSTM3 abundance predicted tumour relapse and poor prognosis. CONCLUSIONS: Our findings elucidate the pivotal role of GSTM3 in IR-induced ferroptosis, offering strategies for the treatment of radiation-resistant or recurrent NPC.


Subject(s)
Ferroptosis , Nasopharyngeal Neoplasms , Humans , Nasopharyngeal Carcinoma/radiotherapy , Neoplasm Recurrence, Local , Radiation Tolerance , Fatty Acid Synthases , Nasopharyngeal Neoplasms/pathology , Glutathione Transferase , Ubiquitin Thiolesterase , Fatty Acid Synthase, Type I
7.
Anal Chem ; 96(14): 5580-5588, 2024 Apr 09.
Article in English | MEDLINE | ID: mdl-38532617

ABSTRACT

Herein, a novel strategy was implemented to modulate the supramolecular interaction between enantiomers and chiral recognition sites (CRSs), effectively resolving the issue of CRS saturation. Randomly methylated-ß-cyclodextrin (Rm-ß-CD) was used as the CRS (host molecule), and polymerized ionic liquids [poly([vbim]TFSI)] were used as the supramolecular modulator (guest molecule), which self-assembled to generate thermosensitive supramolecular host/guest complexes. The enantiomeric binding capacity and enantioselectivity of chiral separation systems centered on supramolecular host-guest complexes are characterized by a high degree of temperature dependence. Poly([vbim]TFSI) bonded to Rm-ß-CD at temperatures between 17 °C ± 3 and 50 °C ± 3 °C, and the binding free energy difference (|ΔΔG|) between the (S)- and (R)-enantiomer was 0.55. Conversely, poly([vbim]TFSI detached from Rm-ß-CD at temperatures >50 °C ± 3 °C or <17 °C ± 3 °C, and |ΔΔG| between (S)- and (R)-enantiomer was 0.03. The |ΔΔG| value of the (R)-enantiomer can reach 0.86 in two temperature intervals. Therefore, the binding of poly([vbim]TFSI) to Rm-ß-CD afforded the favorable separation of four racemic sample mixtures: mandelic acid (e.e.% = 61.3%), ibuprofen (e.e.% = 21.6%), warfarin (e.e.% = 14.9%), and naproxen (e.e% = 18.2%). The detachment of poly([vbim]TFSI) from Rm-ß-CD released the enantiomer bound to CRSs. The decomplexation of mandelic acid reached 75.1%.

8.
Anal Chem ; 96(21): 8416-8423, 2024 May 28.
Article in English | MEDLINE | ID: mdl-38755966

ABSTRACT

Nanogap-based plasmonic metal nanocrystals have been applied in surface-enhanced Raman scattering detection, while the closed and insufficient electromagnetic fields as well as the nonreproducible Raman signal of the substrate greatly restrict the actual application. Herein, a highly uniform Au/AgAu monolayer with abundant nanogaps and huge electromagnetic enhancement is prepared, which shows ultrasensitive and reproducible SERS detection. Au/AgAu with an inner nanogap is first prepared based on Au nanotriangles, and the nanogap is opened from the three tips via a subsequent etching process. The open-gap Au/AgAu displays much higher SERS efficiency than Au and Au/AgAu with an inner nanogap on detecting crystal violet due to the open-gap induced electromagnetic enhancement and improved molecular absorption. Furthermore, the open-gap Au/AgAu monolayer is prepared via interfacial self-assembly, which shows further improved SERS due to the dense and strong hotspots in the nanocavities induced by the electromagnetic coupling between adjacent open gaps. The monolayer possesses excellent signal stability, uniformity, and reproducibility. The analytic enhancement factor and relative standard deviation reach to 2.12 × 108 and 4.65% on detecting crystal violet, respectively. Moreover, the monolayer achieves efficient detection of thiram in apple juice, biphenyl-4-thiol, 4-mercaptobenzoic, melamine, and a mixed solution of four different molecules, showing great promise in practical detection.

9.
Immunol Cell Biol ; 102(7): 570-577, 2024 Aug.
Article in English | MEDLINE | ID: mdl-38710590

ABSTRACT

The γδ T cells are a subpopulation of T cells that are abundantly found in the skin and mucous membranes. Their reactivity to self-antigens and ability to secrete various cytokines make them a key component in psoriasis development. Although the correlation between the immune repertoire (IR) of γδ T-cell receptors and the occurrence and severity of psoriasis remains incompletely explored, high-throughput sequencing of γδ T cells has led to a deeper understanding of IR in psoriasis. This study investigated the differences between γδ T cells in patients with psoriasis and healthy controls. The γδ T cells were identified via immunofluorescence staining and a correlation analysis was performed according to the psoriasis area and severity index (PASI) scores. The IR sequencing method was used to detect IR in the γδ T-cell receptors. The findings demonstrated more skin γδ T cells in patients with psoriasis, which were positively correlated with the PASI score. There were subtle differences in most variable (V), diversity (D) and joining (J) gene segments and VJ/VDJ combination segments between patients with psoriasis and healthy controls. However, a higher diversity of complementarity-determining region 3 (CDR3) was observed in patients with psoriasis. In summary, the IR of skin γδ T cells was significantly altered in patients with psoriasis, and the diversity in the cell's CDR3 population is a promising biomarker for assessment of psoriasis severity.


Subject(s)
Complementarity Determining Regions , Psoriasis , Receptors, Antigen, T-Cell, gamma-delta , Humans , Psoriasis/immunology , Receptors, Antigen, T-Cell, gamma-delta/metabolism , Receptors, Antigen, T-Cell, gamma-delta/genetics , Receptors, Antigen, T-Cell, gamma-delta/immunology , Male , Female , Adult , Middle Aged , Complementarity Determining Regions/genetics , Skin/immunology , Skin/pathology , Severity of Illness Index , T-Lymphocytes/immunology , T-Lymphocytes/metabolism , Case-Control Studies
10.
Small ; : e2407425, 2024 Sep 30.
Article in English | MEDLINE | ID: mdl-39350438

ABSTRACT

The characteristics of solid electrolyte interphase (SEI) at both the cathode and anode interfaces are crucial for the performance of sodium-ion batteries (SIBs). The research demonstrates the merits of a balanced organic component, specifically the organic sodium alkyl sulfonate (ROSO2Na) featured in this work, in conjunction with the inorganic sodium fluoride (NaF), to enhance the interfacial stability. Using a customized electrolyte, it has optimized the interphase, curbing excess NaF production, and created a thin and uniform NaF/ROSO2Na-rich SEI layer. It offers exceptional protection against interface deterioration, transition metal dissolution, and concurrently ensures a consistent reduction in interfacial impedance. This creative approach results in a substantial improvement in the performance of both the Na0.9Ni0.4Fe0.2Mn0.4O2 cathode and the hard carbon anode. The cathode demonstrates remarkable average Coulombic efficiency exceeding 99.9% and a capacity retention of 81% after 500 cycles. Furthermore, the Ah-level pouch cell has shown outstanding performance with an 87% capacity retention after 400 cycles. Moving beyond the prevailing focus on inorganic-rich SEI, these results highlight the effectiveness of the customized organic-inorganic hybrid SEI formulation in improving SIB technology, offering an adaptable solution that ensures superior interfacial stability.

11.
Epidemiology ; 35(4): 559-567, 2024 Jul 01.
Article in English | MEDLINE | ID: mdl-38534181

ABSTRACT

BACKGROUND: Artificial light at night, a well-recognized circadian clock disrupter, causes disturbances in endocrine homeostasis. However, the association of artificial light at night with polycystic ovary syndrome (PCOS) is still unknown. This study examines the effects of outdoor artificial light at night on sex hormones, glucose homeostasis markers, and PCOS prevalence in Anhui Province, China. METHODS: We recruited 20,633 women of reproductive age from Anhui Medical University Reproductive Medicine Center. PCOS was diagnosed according to Rotterdam criteria. We estimated long-term (previous year) and short-term (previous month) artificial light at night values for residential addresses using 500 m resolution satellite imagery. We fitted multivariable models, using both linear and logistic regression, to estimate the association of artificial light at night with sex hormones, glucose homeostasis markers, and PCOS prevalence. RESULTS: Both long-term and short-term exposure to outdoor artificial light at night were negatively associated with follicle-stimulating hormone and luteinizing hormone levels, while positively associated with testosterone, fasting insulin, homeostasis model assessment-insulin resistance, and homeostasis model assessment-insulin resistance-ß levels. The second-highest quintile of artificial light at night was associated with increased PCOS prevalence (odds ratio [OR long-term ] = 1.4; 95% confidence interval [CI] = 1.2, 1.6 and OR short-term = 1.3; 95% CI = 1.1, 1.5) compared with the lowest quintile. In addition, prevalence of PCOS was linearly associated with long-term exposure to artificial light at night, but nonlinearly associated with short-term exposure. This association was more evident in younger, obese or overweight, moderately educated, rural women, and for the summer and fall seasons. CONCLUSION: Outdoor artificial light at night may be a novel risk factor for PCOS.


Subject(s)
Follicle Stimulating Hormone , Homeostasis , Insulin Resistance , Luteinizing Hormone , Polycystic Ovary Syndrome , Humans , Female , Polycystic Ovary Syndrome/epidemiology , Adult , China/epidemiology , Luteinizing Hormone/blood , Young Adult , Follicle Stimulating Hormone/blood , Blood Glucose/analysis , Lighting/adverse effects , Testosterone/blood , Prevalence , Adolescent , Insulin/blood , Logistic Models
12.
Chem Res Toxicol ; 37(7): 1187-1198, 2024 Jul 15.
Article in English | MEDLINE | ID: mdl-38837948

ABSTRACT

Hydroquinone(HQ) is a widely used industrial raw material and is a topical lightening product found in over-the-counter products. However, inappropriate exposure to HQ can pose certain health hazards. This study aims to explore the mechanisms of DNA damage and cell apoptosis caused by HQ, with a focus on whether HQ activates the nuclear factor-κB (NF-κB) pathway to participate in this process and to investigate the correlation between the NF-κB pathway activation and poly(ADP-ribose) polymerase 1(PARP1). Through various experimental techniques, such as DNA damage detection, cell apoptosis assessment, cell survival rate analysis, immunofluorescence, and nuclear-cytoplasmic separation, the cytotoxic effects of HQ were verified, and the activation of the NF-κB pathway was observed. Simultaneously, the relationship between the NF-κB pathway and PARP1 was verified by shRNA interference experiments. The results showed that HQ could significantly activate the NF-κB pathway, leading to a decreased cell survival rate, increased DNA damage, and cell apoptosis. Inhibiting the NF-κB pathway could significantly reduce HQ-induced DNA damage and cell apoptosis and restore cell proliferation and survival rate. shRNA interference experiments further indicated that the activation of the NF-κB pathway was regulated by PARP1. This study confirmed the important role of the NF-κB pathway in HQ-induced DNA damage and cell apoptosis and revealed that the activation of the NF-κB pathway was mediated by PARP1. This research provides important clues for a deeper understanding of the toxic mechanism of HQ.


Subject(s)
Apoptosis , Cell Survival , DNA Damage , Hydroquinones , NF-kappa B , Poly (ADP-Ribose) Polymerase-1 , Apoptosis/drug effects , Poly (ADP-Ribose) Polymerase-1/metabolism , Poly (ADP-Ribose) Polymerase-1/antagonists & inhibitors , Hydroquinones/pharmacology , Humans , NF-kappa B/metabolism , DNA Damage/drug effects , Cell Survival/drug effects , Cell Line , Signal Transduction/drug effects , Dose-Response Relationship, Drug
13.
FASEB J ; 37(3): e22806, 2023 03.
Article in English | MEDLINE | ID: mdl-36786722

ABSTRACT

Recent studies already confirmed that placenta mitochondrial dysfunction is associated with the progression of gestational diabetes mellitus (GDM). Besides, a possible relationship between adipokine chemerin and disulfide-bond A oxidoreductase-like protein (DsbA-L) had been revealed, whereas the potential interaction remains unclear. In addition, very little is still known about the cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) signaling pathway and its mechanisms of action in the context of GDM. The present study aims to investigate the underlying mechanism of cGAS-STING pathway and its regulatory relationship with chemerin in GDM. A total of 50 participants, including 25 cases of GDM patients and 25 pregnant women with normal glucose tolerance, were enrolled, and their placenta tissues at term labor were collected. Besides, an insulin resistance cell model was established on the human trophoblastic cell line to explore the molecular mechanism of chemerin on cGAS-STING pathway. Results showed that there were mitochondrial pathological changes in GDM placenta, accompanied by the decreased expression of DsbA-L, increased level of chemerin, and the activation of cGAS-STING pathway. In the insulin resistant cell model, overexpression of chemerin upregulated protein expression of DsbA-L, and recombinant chemerin presented time-dependent inhibition on the cGAS-STING pathway, but this effect was not dependent on DsbA-L. In conclusion, elevated chemerin is probably a protective mechanism, which may be a potential therapeutic strategy for GDM.


Subject(s)
Diabetes, Gestational , Female , Humans , Pregnancy , Adipokines , Diabetes, Gestational/metabolism , Nucleotidyltransferases/metabolism , Placenta/metabolism , Signal Transduction
14.
Mol Psychiatry ; 28(3): 1365-1382, 2023 03.
Article in English | MEDLINE | ID: mdl-36473997

ABSTRACT

Chronic stress exposure induces maladaptive behavioral responses and increases susceptibility to neuropsychiatric conditions. However, specific neuronal populations and circuits that are highly sensitive to stress and trigger maladaptive behavioral responses remain to be identified. Here we investigate the patterns of spontaneous activity of proopiomelanocortin (POMC) neurons in the arcuate nucleus (ARC) of the hypothalamus following exposure to chronic unpredictable stress (CUS) for 10 days, a stress paradigm used to induce behavioral deficits such as anhedonia and behavioral despair [1, 2]. CUS exposure increased spontaneous firing of POMC neurons in both male and female mice, attributable to reduced GABA-mediated synaptic inhibition and increased intrinsic neuronal excitability. While acute activation of POMC neurons failed to induce behavioral changes in non-stressed mice of both sexes, subacute (3 days) and chronic (10 days) repeated activation of POMC neurons was sufficient to induce anhedonia and behavioral despair in males but not females under non-stress conditions. Acute activation of POMC neurons promoted susceptibility to subthreshold unpredictable stress in both male and female mice. Conversely, acute inhibition of POMC neurons was sufficient to reverse CUS-induced anhedonia and behavioral despair in both sexes. Collectively, these results indicate that chronic stress induces both synaptic and intrinsic plasticity of POMC neurons, leading to neuronal hyperactivity. Our findings suggest that POMC neuron dysfunction drives chronic stress-related behavioral deficits.


Subject(s)
Anhedonia , Arcuate Nucleus of Hypothalamus , Depression , Neurons , Pro-Opiomelanocortin , Stress, Psychological , Animals , Female , Male , Mice , Acute Disease , Anhedonia/physiology , Arcuate Nucleus of Hypothalamus/metabolism , Arcuate Nucleus of Hypothalamus/physiopathology , Cerebral Cortex/metabolism , Cerebral Cortex/physiopathology , Chronic Disease , Cortical Excitability/physiology , Depression/metabolism , Depression/physiopathology , Disease Models, Animal , Mental Disorders/metabolism , Mental Disorders/physiopathology , Mice, Inbred C57BL , Nervous System Physiological Phenomena , Neuronal Plasticity/physiology , Neurons/metabolism , Neurons/physiology , Pro-Opiomelanocortin/biosynthesis , Pro-Opiomelanocortin/metabolism , Stress, Psychological/metabolism , Stress, Psychological/physiopathology , Synapses/metabolism , Synapses/physiology
15.
J Org Chem ; 89(19): 14164-14176, 2024 Oct 04.
Article in English | MEDLINE | ID: mdl-39291865

ABSTRACT

Based on rich sulfur-involving chemical transformations, a novel spokewise synthetic strategy, a subclass of the collective strategies, has been developed to concisely synthesize four erythrina alkaloids through a single-step transformation from a common synthetic precursor. Moreover, six additional erythrina alkaloids have also been synthesized by subsequent 1-2 steps chemical transformations. The current synthetic approaches provide a valuable platform for collective total syntheses of erythrina alkaloids and pseudo-natural erythrina alkaloids.

16.
Inorg Chem ; 63(17): 7926-7936, 2024 Apr 29.
Article in English | MEDLINE | ID: mdl-38621361

ABSTRACT

Heteroatom doping and heterostructure construction are the key methods to improve the performance of electrocatalysts. However, developing such catalysts remains a challenging task. Herein, we designed two comparable polymers, phytic acid/thiourea polymer (PATP) and phytic acid/urea polymer (PAUP), as precursors, which contain C, N, S/O, and P by microwave heating. To pinpoint how the introduction of sulfur would affect the electronic structure and catalytic activity, these two polymers were physically blended with CoCo-Prussian blue analogue (CoCo-PBA) and further calcination, respectively. The highly dispersed CoP/Co2P-rich interfacial catalysts anchored on the N,S-codoped or N-doped carbon support were successfully prepared (CoP/Co2P@CNS and CoP/Co2P@CN). The prepared CoP/Co2P@CNS catalyst showed good ORR properties (E1/2 = 0.856 V vs RHE) and OER properties (Ej10 = 1.54 V vs RHE), which were superior to the commercial Pt/C and RuO2 catalysts. The reversible oxygen electrode index (ΔE = Ej10 - E1/2) can reach ∼0.684 V. Meanwhile, the rechargeable zinc-air battery assembled with a CoP/Co2P@CNS catalyst as the air cathode also showed excellent performance, with a charge-discharge cycle stability of up to 900 h. DFT calculations further confirm that the introduction of S atoms can affect the electronic structure and enhance the catalytic activity of C and N atoms on carbon support.

17.
Nanotechnology ; 35(20)2024 Feb 27.
Article in English | MEDLINE | ID: mdl-38316042

ABSTRACT

A novel defect control approach based on laminated HfO2/ZrO2with multifunctional TiN/Mo/TiOxNyelectrode is proposed to significantly improve the endurance and data retention in HZO-based ferroelectric capacitor. The O-rich interface reduces leakage current and prolong the endurance up to 1011cycles while retaining a 2Pr value of 34 (µC cm-2) at 3.4 MV cm-1. Using first-principles calculations and experiments, we demonstrate that the enhancement of endurance is ascribed to the higher migration barrier of oxygen vacancies within the laminated HZO film and higher work function of MoOx/TiOxNybetween top electrode and the insulating oxide. This 2.5 nm thick TiOxNybarrier further increase the grain size of HZO, lowering the activation field and thus improving polarization reversal speed. This interfacial layer further decreases the overall capacitance, increases the depolarization field, thereby enhancing the data retention. By fitting the data using the Arrhenius equation, we demonstrate a 10 years data retention is achieved at 109.6 °C, surpassing traditional SS-HZO of 78.2 °C with a 450 °C rapid thermal annealing (required by backend-of-the-line). This work elucidates that interfacial engineering serves as a crucial technology capable of resolving the endurance, storage capability, and high-temperature data retention issues for ferroelectric memory.

18.
Bioorg Chem ; 153: 107791, 2024 Sep 02.
Article in English | MEDLINE | ID: mdl-39244974

ABSTRACT

Resveratrol (Res) has long been discovered to have antioxidant effects to prevent such as oxidation, inflammation, neurodegeneration and age-related diseases. However, its poor water solubility, low bioavailability and instability have become a barrier to its pharmaceutical application. In order to improve the neuroprotective effects and develop more potential usage of Res, three Res derivatives containing one or two glucose groups, i.e., Res-Glu1, Res-Glu2 and Res-Glu3, were designed and synthesized through click reaction. Res-Glu1, Res-Glu2 and Res-Glu3 were tested being better water solubility and stability compared to Res. Res derivatives reduced •OH radicals-induced DNA damage. PC12 assays indicated that glucosylated Res derivatives could alleviate H2O2-induced neurotoxicity and reduce intracellular ROS generation, demonstrating their neuroprotective effects. In addition, Res derivatives enhanced the protective effects on cerebral ischemia-reperfusion injury in rats. Res-Glu3 displayed the best neuroprotective effects among the three derivatives.

19.
Environ Res ; 257: 119159, 2024 Sep 15.
Article in English | MEDLINE | ID: mdl-38754605

ABSTRACT

Triphenyl phosphate (TPhP) is an organophosphate flame retardant that is widely used in many commercial products. The United States Environmental Protection Agency has listed TPhP as a priority compound that requires health risk assessment. We previously found that TPhP could accumulate in the placentae of mice and impair birth outcomes by activating peroxisome proliferator-activated receptor gamma (PPARγ) in the placental trophoblast. However, the underlying mechanism remains unknown. In this study, we used a mouse intrauterine exposure model and found that TPhP induced preeclampsia (PE)-like symptoms, including new on-set gestational hypertension and proteinuria. Immunofluorescence analysis showed that during placentation, PPARγ was mainly expressed in the labyrinth layer and decidua of the placenta. TPhP significantly decreased placental implantation depth and impeded uterine spiral artery remodeling by activating PPARγ. The results of the in vitro experiments confirmed that TPhP inhibited extravillous trophoblast (EVT) cell migration and invasion by activating PPARγ and inhibiting the PI3K-AKT signaling pathway. Overall, our data demonstrated that TPhP could activate PPARγ in EVT cells, inhibit cell migration and invasion, impede placental implantation and uterine spiral artery remodeling, then induce PE-like symptom and impair birth outcomes. Although the exposure doses used in this study was several orders of magnitude higher than human daily intake, our study highlights the placenta as a potential target organ of TPhP worthy of further research.


Subject(s)
Organophosphates , Placentation , Pre-Eclampsia , Animals , Female , Pregnancy , Pre-Eclampsia/chemically induced , Mice , Placentation/drug effects , Organophosphates/toxicity , Flame Retardants/toxicity , Placenta/drug effects , PPAR gamma/metabolism , PPAR gamma/genetics , Trophoblasts/drug effects , Prenatal Exposure Delayed Effects/chemically induced
20.
J Nanobiotechnology ; 22(1): 295, 2024 May 28.
Article in English | MEDLINE | ID: mdl-38807131

ABSTRACT

The signal sequence played a crucial role in the efficacy of mRNA vaccines against virus pandemic by influencing antigen translation. However, limited research had been conducted to compare and analyze the specific mechanisms involved. In this study, a novel approach was introduced by substituting the signal sequence of the mRNA antigen to enhance its immune response. Computational simulations demonstrated that various signal peptides differed in their binding capacities with the signal recognition particle (SRP) 54 M subunit, which positively correlated with antigen translation efficiency. Our data revealed that the signal sequences of tPA and IL-6-modified receptor binding domain (RBD) mRNA vaccines sequentially led to higher antigen expression and elicited more robust humoral and cellular immune protection against the SARS-CoV-2 compared to the original signal sequence. By highlighting the importance of the signal sequence, this research provided a foundational and safe approach for ongoing modifications in signal sequence-antigen design, aiming to optimize the efficacy of mRNA vaccines.


Subject(s)
Protein Sorting Signals , SARS-CoV-2 , mRNA Vaccines , Animals , Mice , SARS-CoV-2/immunology , COVID-19/prevention & control , COVID-19/immunology , Mice, Inbred BALB C , RNA, Messenger/genetics , COVID-19 Vaccines/immunology , Female , Humans , Antigens, Viral/immunology , Antigens, Viral/genetics , Antigens, Viral/chemistry , Antibodies, Viral/immunology , Immunity, Humoral , Vaccines, Synthetic/immunology , Immunity, Cellular
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