ABSTRACT
Different functional regions of brain are fundamental for basic neurophysiological activities. However, the regional specification remains largely unexplored during human brain development. Here, by combining spatial transcriptomics (scStereo-seq) and scRNA-seq, we built a spatiotemporal developmental atlas of multiple human brain regions from 6-23 gestational weeks (GWs). We discovered that, around GW8, radial glia (RG) cells have displayed regional heterogeneity and specific spatial distribution. Interestingly, we found that the regional heterogeneity of RG subtypes contributed to the subsequent neuronal specification. Specifically, two diencephalon-specific subtypes gave rise to glutamatergic and GABAergic neurons, whereas subtypes in ventral midbrain were associated with the dopaminergic neurons. Similar GABAergic neuronal subtypes were shared between neocortex and diencephalon. Additionally, we revealed that cell-cell interactions between oligodendrocyte precursor cells and GABAergic neurons influenced and promoted neuronal development coupled with regional specification. Altogether, this study provides comprehensive insights into the regional specification in the developing human brain.
Subject(s)
Brain , Transcriptome , Humans , Dopaminergic Neurons , GABAergic Neurons , Mesencephalon , Neocortex , Brain/growth & development , Brain/metabolismABSTRACT
Programmed cell death and caspase proteins play a pivotal role in host innate immune response combating pathogen infections. Blocking cell death is employed by many bacterial pathogens as a universal virulence strategy. CopC family type III effectors, including CopC from an environmental pathogen Chromobacterium violaceum, utilize calmodulin (CaM) as a co-factor to inactivate caspases by arginine ADPR deacylization. However, the molecular basis of the catalytic and substrate/co-factor binding mechanism is unknown. Here, we determine successive cryo-EM structures of CaM-CopC-caspase-3 ternary complex in pre-reaction, transition, and post-reaction states, which elucidate a multistep enzymatic mechanism of CopC-catalyzed ADPR deacylization. Moreover, we capture a snapshot of the detachment of modified caspase-3 from CopC. These structural insights are validated by mutagenesis analyses of CopC-mediated ADPR deacylization in vitro and animal infection in vivo. Our study offers a structural framework for understanding the molecular basis of arginine ADPR deacylization catalyzed by the CopC family.
Subject(s)
Calmodulin , Caspases , Animals , Calmodulin/genetics , Calmodulin/metabolism , Caspases/metabolism , Caspase 3/metabolism , Arginine , Catalysis , Bacterial Proteins/genetics , Bacterial Proteins/metabolismABSTRACT
BACKGROUND: Cancer stem-like cell is a key barrier for therapeutic resistance and metastasis in various cancers, including breast cancer, yet the underlying mechanisms are still elusive. Through a genome-wide lncRNA expression profiling, we identified that LINC00115 is robustly upregulated in chemoresistant breast cancer stem-like cells (BCSCs). METHODS: LncRNA microarray assay was performed to document abundance changes of lncRNAs in paclitaxel (PTX)-resistant MDA-MB-231 BCSC (ALDH+) and non-BCSC (ALDH-). RNA pull-down and RNA immunoprecipitation (RIP) assays were performed to determine the binding proteins of LINC00115. The clinical significance of the LINC00115 pathway was examined in TNBC metastatic lymph node tissues. The biological function of LINC00115 was investigated through gain- and loss-of-function studies. The molecular mechanism was explored through RNA sequencing, mass spectrometry, and the CRISPR/Cas9-knockout system. The therapeutic potential of LINC00115 was examined through xenograft animal models. RESULTS: LINC00115 functions as a scaffold lncRNA to link SETDB1 and PLK3, leading to enhanced SETDB1 methylation of PLK3 at both K106 and K200 in drug-resistant BCSC. PLK3 methylation decreases PLK3 phosphorylation of HIF1α and thereby increases HIF1α stability. HIF1α, in turn, upregulates ALKBH5 to reduce m6A modification of LINC00115, resulting in attenuated degradation of YTHDF2-dependent m6A-modified RNA and enhanced LINC00115 stability. Thus, this positive feedback loop provokes BCSC phenotypes and enhances chemoresistance and metastasis in triple-negative breast cancer. SETDB1 inhibitor TTD-IN with LINC00115 ASO sensitizes PTX-resistant cell response to chemotherapy in a xenograft animal model. Correlative expression of LINC00115, methylation PLK3, SETDB1, and HIF1α are prognostic for clinical triple-negative breast cancers. CONCLUSIONS: Our findings uncover LINC00115 as a critical regulator of BCSC and highlight targeting LINC00115 and SETDB1 as a potential therapeutic strategy for chemotherapeutic resistant breast cancer.
Subject(s)
RNA, Long Noncoding , Triple Negative Breast Neoplasms , Animals , Humans , RNA, Long Noncoding/genetics , RNA, Long Noncoding/metabolism , Cell Line, Tumor , Breast/metabolism , Signal Transduction , Triple Negative Breast Neoplasms/drug therapy , Triple Negative Breast Neoplasms/genetics , Triple Negative Breast Neoplasms/metabolism , Paclitaxel/pharmacology , Disease Models, Animal , Neoplastic Stem Cells/metabolism , Histone-Lysine N-Methyltransferase/metabolism , Polo-like Kinases , Protein Serine-Threonine Kinases/metabolism , Tumor Suppressor Proteins/metabolismABSTRACT
The eco-friendliness, safety, and affordability of aqueous potassium batteries (AKIBs) have made them popular for large-scale energy storage devices. However, the cycling and rate performance of research materials, particularly cobalt hexacyanoferrate, have yet to meet satisfactory standards. Herein, a room-temperature drafted K1.66 Fe0.25 Co0.75 [Fe(CN)6 ]·0.83H2 O (KFCHCF) sample is reported using an in situ substitution strategy. A higher concentration of ferrocyanide ions decreases the water content and increases the potassium content, while citric acid works as a chelating agent and is responsible for Fe-substitution in the KFCHCF sample. The resultant KFCHCF sample exhibits good rate performance, and about 97% and 90.6% of discharge capacity are conserved after 400 and 1000 cycles at 100 and 200 mA g-1 , respectively. The full cell using the KFCHCF cathode and 1,4,5,8-naphthalenetetracarboxylic dianhydride-derived polyimide (PNTCDA) anode maintains ≈74.93% and 74.35% of discharge capacity at 200 mA g-1 and 1000 mA g-1 for 1000 and >10,000 cycles, respectively. Furthermore, ex situ characterizations demonstrate the high reversibility of K-ions and structural stability during the charge-discharge process. Such high performance is attributed to the fast K-ion migration and crystal structure stabilization caused by in situ Fe-substitution in the KFCHCF sample. Other hexacyanoferrates can be synthesized using this method and used in grid-scale storage systems.
ABSTRACT
A large amount of evidence shows that biomarkers are discriminant features related to disease development. Thus, the identification of disease biomarkers has become a basic problem in the analysis of complex diseases in the medical fields, such as disease stage judgment, disease diagnosis and treatment. Research based on networks have become one of the most popular methods. Several algorithms based on networks have been proposed to identify biomarkers, however the networks of genes or molecules ignored the similarities and associations among the samples. It is essential to further understand how to construct and optimize the networks to make the identified biomarkers more accurate. On this basis, more effective strategies can be developed to improve the performance of biomarkers identification. In this study, a multi-objective evolution algorithm based on sample similarity networks has been proposed for disease biomarker identification. Specifically, we design the sample similarity networks to extract the structural characteristic information among samples, which used to calculate the influence of the sample to each class. Besides, based on the networks and the group of biomarkers we choose in every iteration, we can divide samples into different classes by the importance for each class. Then, in the process of evolution algorithm population iteration, we develop the elite guidance strategy and fusion selection strategy to select the biomarkers which make the sample classification more accurate. The experiment results on the five gene expression datasets suggests that the algorithm we proposed is superior over some state-of-the-art disease biomarker identification methods.
Subject(s)
Algorithms , BiomarkersABSTRACT
BACKGROUND: Enzymatic crosslinking is a method that can be used to modify Inca peanut albumin (IPA) using polyphenols, and provides desirable functionalities; however, the effect of polyphenol structures on conjugate properties is unclear. In this study, we selected four polyphenols with different numbers of phenolic hydroxyl groups [para-hydroxybenzoic acid (HBA), protocatechuic acid (PCA), gallic acid (GA), and epigallocatechin gallate (EGCG)] for covalent modification of IPA by enzymatic crosslinking, and explored the structure-function changes of the IPA-polyphenol conjugates. RESULTS: Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) analysis showed that laccase successfully promoted covalent crosslinking of IPA with polyphenols, with the order of degree of conjugation as EGCG > GA > PCA > HBA, the IPA-EGCG conjugate showed the highest polyphenol binding equivalents (98.35 g kg-1 protein), and a significant reduction in the content of free amino, sulfhydryl, and tyrosine group. The oxidation of polyphenols by laccase forms quinone or semiquinone radicals that are covalently crosslinked to the reactive groups of IPA, leading to significant changes in the secondary and tertiary structures of IPA, with spherical structures transforming into dense lamellar structures. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging ability and emulsification stability of IPA-EGCG conjugates improved by almost 6-fold and 2.7-fold, respectively, compared with those of unmodified IPA. CONCLUSION: These data suggest that the higher the number of polyphenol hydroxyl groups, the higher the degree of IPA-polyphenol conjugation; additionally, enzymatic crosslinking can significantly improve the functional properties of IPA. © 2024 Society of Chemical Industry.
Subject(s)
Catechin , Polyphenols , Polyphenols/chemistry , Arachis/metabolism , Laccase/metabolism , Phenols , Antioxidants/chemistry , Catechin/chemistry , Catalysis , Gallic Acid , AlbuminsABSTRACT
T-acute lymphoblastic leukemia/lymphoma (T-ALL/LBL) is a malignant neoplasm of immature lymphoblasts. Terminal deoxynucleotidyl transferase (TDT) is a template-independent DNA polymerase that plays an essential role in generating diversity for immunoglobulin genes. T-ALL/LBL patients with TDT- have a worse prognosis. However, how TDT- promotes the disease progression of T-ALL/LBL remains unknown. Here we analyzed the prognosis of T-ALL/LBL patients in Shanghai Children's Medical Center (SCMC) and confirmed that TDT- patients had a higher rate of recurrence and remission failure and worse outcomes. Cellular experiments demonstrated that TDT was involved in DNA damage repair. TDT knockout delayed DNA repair, arrested the cell cycle and decreased apoptosis to induce the accumulation of chromosomal abnormalities and tolerance to abnormal karyotypes. Our study demonstrated that the poor outcomes in TDT- T-ALL/LBL might be due to the drug resistance (VP16 and MTX) induced by chromosomal abnormalities. Our findings revealed novel functions and mechanisms of TDT in T-ALL/LBL and supported that hematopoietic stem cell transplantation (HSCT) might be a better choice for these patients.
Subject(s)
Lymphoma , Precursor Cell Lymphoblastic Leukemia-Lymphoma , Precursor T-Cell Lymphoblastic Leukemia-Lymphoma , Child , Humans , Precursor T-Cell Lymphoblastic Leukemia-Lymphoma/metabolism , DNA Nucleotidylexotransferase/genetics , DNA Nucleotidylexotransferase/metabolism , China , Precursor Cell Lymphoblastic Leukemia-Lymphoma/genetics , DNA-Directed DNA Polymerase/genetics , Chromosome Aberrations , Drug ResistanceABSTRACT
Juvenile myelomonocytic leukaemia (JMML) is an aggressive paediatric leukaemia characterized by mutations in five canonical RAS pathway genes, including the NF1 gene. JMML is driven by germline NF1 gene mutations, with additional somatic aberrations resulting in the NF1 biallelic inactivation, leading to disease progression. Germline mutations in the NF1 gene alone primarily cause benign neurofibromatosis type 1 (NF1) tumours rather than malignant JMML, yet the underlying mechanism remains unclear. Here, we demonstrate that with reduced NF1 gene dose, immune cells are promoted in anti-tumour immune response. Comparing the biological properties of JMML and NF1 patients, we found that not only JMML but also NF1 patients driven by NF1 mutations could increase monocytes generation. But monocytes cannot further malignant development in NF1 patients. Utilizing haematopoietic and macrophage differentiation from iPSCs, we revealed that NF1 mutations or knockout (KO) recapitulated the classical haematopoietic pathological features of JMML with reduced NF1 gene dose. NF1 mutations or KO promoted the proliferation and immune function of NK cells and iMacs derived from iPSCs. Moreover, NF1-mutated iNKs had a high capacity to kill NF1-KO iMacs. NF1-mutated or KO iNKs administration delayed leukaemia progression in a xenograft animal model. Our findings demonstrate that germline NF1 mutations alone cannot directly drive JMML development and suggest a potential cell immunotherapy for JMML patients.
Subject(s)
Leukemia, Myelomonocytic, Juvenile , Neurofibromatosis 1 , Animals , Humans , Leukemia, Myelomonocytic, Juvenile/genetics , Leukemia, Myelomonocytic, Juvenile/therapy , Leukemia, Myelomonocytic, Juvenile/metabolism , Neurofibromin 1/genetics , Genes, Neurofibromatosis 1 , Germ-Line Mutation , Neurofibromatosis 1/genetics , Neurofibromatosis 1/therapy , Mutation , Immunity , Germ Cells/metabolism , Germ Cells/pathologyABSTRACT
The construction of low-fouling biosensors for assaying biomarkers in complex biological samples remains a challenge, and the key limitation is the lack of effective anti-fouling materials. Inspired by the biomimetic process of protein phosphorylation, we herein designed a new phosphorylated peptide modified with the dihydrogen phosphate (-PO4H2) group, which significantly increased the hydrophilicity and anti-fouling capability of the peptide when compared with natural and normal peptides. Molecular simulation (MS) illustrated that, compared with the -COOH and -NH2 groups, the -PO4H2 group formed the most numbers of hydrogen bonds and stronger hydrogen bonds with water molecules. As a result, the PO4H2-oligopeptide was proved by MS to be able to attract the greatest number of water molecules, so as to form a compact layer of H2O to resist further adsorption of nonspecific biomolecules. The modification of electrodes with the designed PO4H2-oligopeptides, in addition to the adoption of neutral peptide nucleic acids (PNAs) as the sensing probes, ensured the fabrication of anti-fouling electrochemical biosensors capable of detecting nucleic acids in complex saliva. The constructed anti-fouling biosensor was able to detect the nucleic acid of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in undiluted saliva, with a wide linear response range (0.01 pM-0.01 µM) and a low limit of detection (LOD) of 3.4 fM (S/N = 3). The phosphorylation of oligopeptides offers an effective strategy to designing ultra-hydrophilic peptides suitable for the construction of promising anti-biofouling biosensors and bioelectronics.
Subject(s)
Biofouling , Biosensing Techniques , COVID-19 , Nucleic Acids , Humans , Biofouling/prevention & control , Phosphorylation , Saliva , SARS-CoV-2 , Peptides/chemistry , Oligopeptides , Electrochemical TechniquesABSTRACT
The rational design of efficient and cost-effective electrocatalysts for oxygen evolution reaction (OER) with sluggish kinetics, is imperative to diverse clean energy technologies. The performance of electrocatalyst is usually governed by the number of active sites on the surface. Crystalline/amorphous heterostructure has exhibited unique properties and opens new paradigms toward designing electrocatalysts with abundant active sites for improved performance. Hence, Fe doped Ni-Co phosphite (Fe-NiCoHPi) electrocatalyst with cauliflower-like structure, comprising crystalline@amorphous core-shell nanorod, is reported. The experiments uncover that Fe is enriched in the amorphous shell due to the flexibility of the amorphous component. Further density functional theory calculations indicate that the strong electronic interaction between the enriched Fe in the amorphous shell and crystalline core host at the core-shell interface, leads to balanced binding energies of OER intermediates, which is the origin of the catalyst-activity. Eventually, the Fe-NiCoHPi exhibits remarkable activity, with low overpotentials of only 206 and 257 mV at current density of 15 and 100 mA cm-2 . Unceasing durability over 90 h is achieved, which is superior to the effective phosphate electrocatalysts. Although the applications at high current remain challenges , this work provides an approach for designing advanced OER electrocatalysts for sustainable energy devices.
ABSTRACT
Noble metal doping can achieve an increase in mass activity (MA) without sacrificing catalysis efficiency and stability, so that alkaline hydrogen evolution reaction (HER) performance of the catalyst can be optimized to the maximum degree. However, its excessively large ionic radius makes it difficult to achieve either interstitial doping or substitutional doping under mild conditions. Herein, a hierarchical nanostructured electrocatalyst with enriched amorphous/crystalline interfaces for high-efficiency alkaline HER is reported, which is composed of amorphous/crystalline (Co, Ni)11 (HPO3 )8 (OH)6 homogeneous hierarchical structure with an ultra-low doped Pt (Pt-a/c-NiHPi). Benefiting from the structural flexibility of the amorphous component, extremely low Pt (0.21 wt.%, totally 3.31 µg Pt on 1 cm-2 NF) are stably doped on it via a simple two-phase hydrothermal method. The DFT calculations show that due to the strongly electron transfer between the crystalline/amorphous components at the interfaces, electrons finally concentrate toward Pt and Ni in the amorphous components, thus the electrocatalyst has near-optimal energy barriers and adsorption energy for H2 O* and H* . With the above benefits, the obtained catalyst exhibits an exceptionally high MA (39.1 mA µg-1 Pt ) at 70 mV, which is almost the highest level among the reported Pt-based electrocatalysts for alkaline HER.
ABSTRACT
Aqueous zinc ion batteries (ZIBs), especially those with self-charging properties, have been promisingly developed in recent years. Yet, most inorganic materials feature high redox potential, which limit their development in the self-charging field. To achieve this target, by pre-embedding potassium ions into δ-MnO2 to reduce the energy barrier in oxygen adsorption, the first application of MnO2 in self-charging ZIBs is realized. The design features a facile two-electrode configuration with no excessively complex component to allow for energy storage and conversion. Due to the voltage difference between the oxygen in the air and the discharge products, a redox reaction can be carried out spontaneously to realize the self-charging process. After the chemical self-charging process, the Zn-K0.37 MnO2 ·0.54H2 O/C cell achieves an open circuit voltage of around 1.42 V and a discharge capacity of 201 mAh g-1 , reflecting the promising self-charging capability. Besides, the chemically self-charging ZIBs operate well in multiple modes of constant current charge/discharge/chemical charging. And decent cycling capability can also be achieved at extreme temperatures and high mass loading. This work promotes the development of ZIBs and further broadens the application of inorganic metal oxides in the self-charging systems.
ABSTRACT
Electrocatalytic hydrogen evolution reaction (HER) in alkaline media is important for hydrogen economy but suffers from sluggish reaction kinetics due to a large water dissociation energy barrier. Herein, Pt5 P2 nanocrystals anchoring on amorphous nickel phosphate nanorods as a high-performance interfacial electrocatalyst system (Pt5 P2 NCs/a-NiPi) for the alkaline HER are demonstrated. At the unique polycrystalline/amorphous interface with abundant defects, strong electronic interaction, and optimized intermediate adsorption strength, water dissociation is accelerated over abundant oxophilic Ni sites of amorphous NiPi, while hydride coupling is promoted on the adjacent electron-rich Pt sites of Pt5 P2 . Meanwhile, the ultra-small-sized Pt5 P2 nanocrystals and amorphous NiPi nanorods maximize the density of interfacial active sites for the Volmer-Tafel reaction. Pt5 P2 NCs/a-NiPi exhibits small overpotentials of merely 9 and 41 mV at -10 and -100 mA cm-2 in 1 M KOH, respectively. Notably, Pt5 P2 NCs/a-NiPi exhibits an unprecedentedly high mass activity (MA) of 14.9 mA µgPt -1 at an overpotential of 70 mV, which is 80 times higher than that of Pt/C and represents the highest MA of reported Pt-based electrocatalysts for the alkaline HER. This work demonstrates a phosphorization and interfacing strategy for promoting Pt utilization and in-depth mechanistic insights for the alkaline HER.
ABSTRACT
Leukemogenesis is characterized by chromosomal rearrangements with additional molecular disruptions, yet the cooperative mechanisms are still unclear. Using whole-exome sequencing of a pair of monozygotic twins who were discordant for childhood acute lymphoblastic leukemia (ALL) with ETV6-RUNX1 (E/R) gene fusion successively after birth, we identified the R209C mutation of G protein subunit α o1 (GNAO1) as a new ALL risk loci. Moreover, GNAO1 missense mutations are recurrent in ALL patients and are associated with E/R fusion. Ectopic expression of the GNAO1 R209C mutant increased its GTPase activity and promoted cell proliferation and cell neoplastic transformation. Combined with the E/R fusion, the GNAO1 R209C mutation promoted leukemogenesis through activating PI3K/Akt/mTOR signaling. Reciprocally, activated mTORC1 phosphorylated p300 acetyltransferase, which acetylated E/R and thereby enhanced the E/R transcriptional activity of GNAO1 R209C. Thus, our study provides clinical evidence of the functional cooperation of GNAO1 mutations and E/R fusion, suggesting GNAO1 as a therapeutic target in human leukemia.
Subject(s)
Carcinogenesis/genetics , GTP-Binding Protein alpha Subunits, Gi-Go/genetics , Precursor Cell Lymphoblastic Leukemia-Lymphoma/genetics , Animals , Cell Line, Tumor , Core Binding Factor Alpha 2 Subunit/genetics , Female , HEK293 Cells , Humans , Male , Mice , Models, Molecular , Mutation , Mutation, Missense , Oncogene Proteins, Fusion/genetics , Point MutationABSTRACT
Organic film capacitors have incredibly high power density and have an irreplaceable position in pulsed power systems, high-voltage power transmission networks and other fields. At present, the energy storage density and energy storage efficiency of organic film capacitors are relatively low, resulting in excessive equipment volume. The performance of organic film capacitors is determined by polymer materials, so it is crucial to develop a polymer composite with high energy storage density and high charge-discharge efficiency. Poly(vinylidene fluoride-co-chlorotrifluoroethylene) (P(VDF-CTFE)) is incorporated into the polyvinylidene fluoride (PVDF) matrix by solution blending. The successful preparation of the all-polymer composite material solves the problems of low breakdown electric field strength, low discharge energy density, and low charge-discharge efficiency of high-dielectric ferroelectric materials. The discharge energy density of the PVDF/P(VDF-CTFE) (70/30) film is more than twice that of pure PVDF due to the increase of phases α and γ and the decrease of crystallinity. Under the breakdown electric field (380 kV mm-1 ), PVDF/P(VDF-CTFE) (70/30) film also has an ultrahigh energy storage efficiency of 64%. The relationship between the structure and properties of composite materials is investigated in this study, which has important implications for the development of capacitors with high energy storage density.
Subject(s)
Electricity , Fluorocarbon Polymers , Polymers , PolyvinylsABSTRACT
OBJECTIVE: Gastric cancer (GC) is a malignant tumor rooting in the gastric mucosal epithelium, ranking the first among various malignant tumors. Therefore, the influence of microRNA-128-3p (miR-128-3p) by regulation of Tuftelin1 (TUFT1) on GC cells was investigated. METHODS: The expression levels of miR-128-3p and TUFT1 in GC tissues and cells were detected. The correlation between miR-128-3p expression and overall survival of GC patients was analyzed. Human GC cells MGC803 were transfected with miR-128-3p or TUFT1-related oligonucleotides to figure their roles in viability, apoptosis, invasion, as well as epithelial-mesenchymal transition (EMT). The relationship between miR-128-3p and TUFT1 was validated. RESULTS: miR-128-3p expression was low and TUFT1 expression was high in GC tissues. miR-128-3p expression was positively correlated with the overall survival of patients with GC. miR-128-3p targeted TUFT1. Up-regulated miR-128-3p or suppressed TUFT1 repressed viability, invasion, and EMT, and accelerated apoptosis of GC cells. Overexpressed TUFT1 reduced miR-128-3p-mediated growth inhibition of GC cells. CONCLUSION: The study stresses that miR-128-3p can inhibit TUFT1 expression, thereby repressing GC cell activities.
Subject(s)
MicroRNAs , Stomach Neoplasms , Humans , Apoptosis , Cell Line, Tumor , Cell Movement , Cell Proliferation , Epithelial-Mesenchymal Transition , Gene Expression Regulation, Neoplastic , MicroRNAs/genetics , MicroRNAs/metabolism , Stomach Neoplasms/pathologyABSTRACT
A reliable and brief ultralow fouling electrochemical sensing system capable of monitoring targets in complex biological media was constructed and validated based on gold nanoparticles-peptide hydrogel-modified screen-printed electrode. The self-assembled zwitterionic peptide hydrogel was prepared by a newly designed peptide sequence of Phe-Phe-Cys-Cys-(Glu-Lys)3 with the N-terminal modified with a fluorene methoxycarbonyl group. The thiol groups on cysteine of the designed peptide are able to self-assemble with AuNPs to form a three-dimensional nanonetwork structure, which showed satisfactory antifouling capability in complex biological media (human serum). The developed gold nanoparticles-peptide hydrogel-based electrochemical sensing platform displayed notably sensing properties for dopamine determination, with a wide linear range (from 0.2 nM to 1.9 µM), a low limit of detection (0.12 nM), and an excellent selectivity. This highly sensitive and ultralow fouling electrochemical sensor was fabricated via simple preparation with concise components that avoid the accumulation of layers with single functional material and complex activation processes. This ultralow fouling and highly sensitive strategy based on the gold nanoparticles-peptide hydrogel with a three-dimensional nanonetwork offers a solution to the current situation of various low-fouling sensing systems facing impaired sensitivity and provides a potential path for the practical application of electrochemical sensors.
Subject(s)
Biofouling , Metal Nanoparticles , Humans , Dopamine/analysis , Gold/chemistry , Metal Nanoparticles/chemistry , Hydrogels , Biofouling/prevention & control , Peptides/chemistryABSTRACT
Cranioplasty is a common neurosurgical procedure; however, the optimal material choice remains controversial. At the time of this writing, autologous bone, the preferred choice for primary cranioplasty, has a high incidence of complications such as infection and resorption, thus requiring frequent use of synthetic materials. Therefore, this study aimed to compare the clinical benefits of titanium mesh (Ti), polyetheretherketone (PEEK), and composite bone cement (CBC) in cranioplasty to provide a clear selection basis for clinicians and patients. This study retrospectively collected data from 207 patients who underwent cranioplasty with Ti (n=129), PEEK (n=54), and CBC (n=24) between January 2018 and December 2020 at Henan Provincial People's Hospital. Postoperative follow-up information after 6 months was used to compare the long-term effects of the 3 materials on the patients. There were no significant differences in the overall complication rate after cranioplasty among the 3 materials. However, subcutaneous effusion was more frequent with PEEK (24.07%) and CBC (20.83%) than with Ti (2.33%). Second, there were no significant differences in the increase in Glasgow Outcome Scale and Karnofsky Performance Status scores after cranioplasty among the 3 materials. Finally, we found that PEEK had the highest patient satisfaction and hospitalization cost, whereas the opposite was true for Ti. Although the surgical outcomes of the 3 implant materials were similar, an examination of clinical outcomes such as patient satisfaction showed significant differences, deepening people's perceptions of the 3 materials.
Subject(s)
Dental Implants , Plastic Surgery Procedures , Humans , Retrospective Studies , Bone Cements , Titanium , Surgical Mesh/adverse effects , Polyethylene Glycols , Ketones , Skull/surgery , Postoperative Complications/etiologyABSTRACT
Sensing noxiously high temperatures is crucial for living organisms to avoid heat-induced injury. The TRPV1 channel has long been known as a sensor for noxious heat. However, the mechanism of how this channel is activated by heat remains elusive. Here we found that a series of polyols including sucrose, sorbitol, and hyaluronan significantly elevate the heat activation threshold temperature of TRPV1. The modulatory effects of these polyols were only observed when they were perfused extracellularly. Interestingly, mutation of residues E601 and E649 in the outer pore region of TRPV1 largely abolished the effects of these polyols. We further observed that intraplantar injection of polyols into the hind paws of rats reduced their heat-induced pain response. Our observations not only suggest that the extracellular regions of TRPV1 are critical for the modulation of heat activation by polyols, but also indicate a potential role of polyols in reducing heat-induced pain sensation.
Subject(s)
Hot Temperature , Polymers/pharmacology , TRPV Cation Channels/metabolism , Amino Acid Sequence , Animals , Capsaicin/pharmacology , Extracellular Space/chemistry , Female , HEK293 Cells , Humans , Ion Channel Gating/drug effects , Polymers/chemistry , Protons , Rats, Wistar , TRPV Cation Channels/chemistryABSTRACT
Transient receptor potential vanilloid 1 (TRPV1) ion channel serves as the detector for noxious temperature above 42 °C, pungent chemicals like capsaicin, and acidic extracellular pH. This channel has also been shown to function as an ionotropic cannabinoid receptor. Despite the solving of high-resolution three-dimensional structures of TRPV1, how endocannabinoids such as anandamide and N-arachidonoyl dopamine bind to and activate this channel remains largely unknown. Here we employed a combination of patch-clamp recording, site-directed mutagenesis, and molecular docking techniques to investigate how the endocannabinoids structurally bind to and open the TRPV1 ion channel. We found that these endocannabinoid ligands bind to the vanilloid-binding pocket of TRPV1 in the "tail-up, head-down" configuration, similar to capsaicin; however, there is a unique interaction with TRPV1 Y512 residue critical for endocannabinoid activation of TRPV1 channels. These data suggest that a differential structural mechanism is involved in TRPV1 activation by endocannabinoids compared with the classic agonist capsaicin.