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1.
Disaster Med Public Health Prep ; 18: e113, 2024 Sep 18.
Article in English | MEDLINE | ID: mdl-39291345

ABSTRACT

OBJECTIVE: The World Health Organization declared the current monkeypox outbreak a public health emergency of international concern (PHEIC) on July 23, 2022, as it has posed a great threat to human health. This bibliometric analysis aimed to explore the current research hotspots focused on monkeypox. METHODS: A systematic search of the Web of Science Core Collection database was conducted for published articles on monkeypox from database inception to February 23, 2023. VOSviewer software was used for analysis and visualization of research results. RESULTS: A total of 1646 publications on monkeypox virus were included for bibliometric analysis. Results showed that (1) the number of publications about monkeypox virus increased significantly in 2022, (2) smallpox and monkeypox virus were popular research keywords, (3) the United States has made the most significant contribution to the study of monkeypox virus, (4) Journal of Virology was the most active journal in publishing articles about monkeypox, and (5) research themes mainly included the body's reaction after monkeypox infection, epidemiology, diagnosis, and pathological mechanisms. CONCLUSIONS: Future research should focus on early sensitive diagnostic measures of monkeypox and the development of vaccines based on the characteristics of the virus. Study findings also provided key areas for public health experts to focus on and collaborate with policymakers.


Subject(s)
Bibliometrics , Monkeypox virus , Mpox (monkeypox) , Humans , Monkeypox virus/pathogenicity , Mpox (monkeypox)/epidemiology , Disease Outbreaks/statistics & numerical data , Publications/statistics & numerical data , Publications/trends
2.
Mol Neurobiol ; 61(3): 1818-1832, 2024 Mar.
Article in English | MEDLINE | ID: mdl-37782443

ABSTRACT

Perioperative neurocognitive disorders (PNDs) are severe and common neurological complications among elderly patients following anesthesia and surgery. As the first line of defense of the innate immune system, Toll-like receptors (TLRs) have been found to be involved in the occurrence of neurodegenerative diseases in recent years. However, the role of TLR7 in the pathology and development of PNDs remains largely unclear. In our current study, we hypothesized that increased microRNA let-7b (let-7b) during anesthesia and surgical operation would activate TLR7 signaling pathways and mediate PNDs. Using a mouse model of PNDs, 18-20 months wild-type (WT) mice were undergoing unilateral nephrectomy, and increased TLR7 and let-7b expression levels were found in the surgery group compared with the Sham group. Of note, increased TLR7 was found to be co-localized with let-7b in the hippocampal area CA1 in the PNDs model. In addition, TLR7 and let-7b inhibition could improve hippocampus-dependent memory and attenuate the production of inflammatory cytokines. Together, our results indicated that TLR7 activation and up-regulation might be triggered by increased let-7b under stressful conditions and initiated the downstream inflammatory signaling, playing a substantial role in the development of PNDs.


Subject(s)
Anesthesia , Cognitive Dysfunction , MicroRNAs , Humans , Animals , Mice , Aged , Toll-Like Receptor 7/genetics , MicroRNAs/genetics , MicroRNAs/metabolism , Signal Transduction/physiology
3.
Adv Sci (Weinh) ; 11(10): e2305554, 2024 03.
Article in English | MEDLINE | ID: mdl-38143270

ABSTRACT

Acknowledging the neurological symptoms of COVID-19 and the long-lasting neurological damage even after the epidemic ends are common, necessitating ongoing vigilance. Initial investigations suggest that extracellular vesicles (EVs), which assist in the evasion of the host's immune response and achieve immune evasion in SARS-CoV-2 systemic spreading, contribute to the virus's attack on the central nervous system (CNS). The pro-inflammatory, pro-coagulant, and immunomodulatory properties of EVs contents may directly drive neuroinflammation and cerebral thrombosis in COVID-19. Additionally, EVs have attracted attention as potential candidates for targeted therapy in COVID-19 due to their innate homing properties, low immunogenicity, and ability to cross the blood-brain barrier (BBB) freely. Mesenchymal stromal/stem cell (MSCs) secreted EVs are widely applied and evaluated in patients with COVID-19 for their therapeutic effect, considering the limited antiviral treatment. This review summarizes the involvement of EVs in COVID-19 neuropathology as carriers of SARS-CoV-2 or other pathogenic contents, as predictors of COVID-19 neuropathology by transporting brain-derived substances, and as therapeutic agents by delivering biotherapeutic substances or drugs. Understanding the diverse roles of EVs in the neuropathological aspects of COVID-19 provides a comprehensive framework for developing, treating, and preventing central neuropathology and the severe consequences associated with the disease.


Subject(s)
COVID-19 , Central Nervous System Diseases , Extracellular Vesicles , Humans , Blood-Brain Barrier , Brain/pathology , Brain/virology , COVID-19/pathology , Central Nervous System Diseases/virology
4.
Brain Sci ; 13(9)2023 Aug 30.
Article in English | MEDLINE | ID: mdl-37759860

ABSTRACT

Drug addiction is one of the major worldwide health problems, which will have serious adverse consequences on human health and significantly burden the social economy and public health. Drug abuse is more common in anesthesiologists than in the general population because of their easier access to controlled substances. Although opioids have been generally considered the most commonly abused drugs among anesthesiologists and nurse anesthetists, the abuse of non-opioid anesthetics has been increasingly severe in recent years. The purpose of this review is to provide an overview of the clinical situation and potential molecular mechanisms of non-opioid anesthetics addiction. This review incorporates the clinical and biomolecular evidence supporting the abuse potential of non-opioid anesthetics and the foreseeable mechanism causing the non-opioid anesthetics addiction phenotypes, promoting a better understanding of its pathogenesis and helping to find effective preventive and curative strategies.

5.
Signal Transduct Target Ther ; 8(1): 292, 2023 08 07.
Article in English | MEDLINE | ID: mdl-37544956

ABSTRACT

Chronic pain is often associated with cognitive decline, which could influence the quality of the patient's life. Recent studies have suggested that Toll-like receptor 3 (TLR3) is crucial for memory and learning. Nonetheless, the contribution of TLR3 to the pathogenesis of cognitive decline after chronic pain remains unclear. The level of TLR3 in hippocampal neurons increased in the chronic constriction injury (CCI) group than in the sham group in this study. Importantly, compared to the wild-type (WT) mice, TLR3 knockout (KO) mice and TLR3-specific neuronal knockdown mice both displayed improved cognitive function, reduced levels of inflammatory cytokines and neuronal apoptosis and attenuated injury to hippocampal neuroplasticity. Notably, extracellular RNAs (exRNAs), specifically double-stranded RNAs (dsRNAs), were increased in the sciatic nerve, serum, and hippocampus after CCI. The co-localization of dsRNA with TLR3 was also increased in hippocampal neurons. And the administration of poly (I:C), a dsRNA analog, elevated the levels of dsRNAs and TLR3 in the hippocampus, exacerbating hippocampus-dependent memory. In additon, the dsRNA/TLR3 inhibitor improved cognitive function after CCI. Together, our findings suggested that exRNAs, particularly dsRNAs, that were present in the condition of chronic neuropathic pain, activated TLR3, initiated downstream inflammatory and apoptotic signaling, caused damage to synaptic plasticity, and contributed to the etiology of cognitive impairment after chronic neuropathic pain.


Subject(s)
Chronic Pain , Cognitive Dysfunction , Neuralgia , Mice , Animals , Chronic Pain/genetics , Chronic Pain/complications , Toll-Like Receptor 3/genetics , Neuralgia/genetics , Neuralgia/pathology , Cognitive Dysfunction/genetics , Mice, Knockout , RNA, Double-Stranded
7.
BMC Psychiatry ; 22(1): 731, 2022 11 24.
Article in English | MEDLINE | ID: mdl-36424595

ABSTRACT

BACKGROUND: With the rapid progress of high-throughput sequencing technology, characterization of schizophrenia (SZ) with underlying probing of the gut microbiome can explore pathogenic mechanisms, estimate disease risk, and allow customization of therapeutic and prophylactic modalities. In this study, we compared the differences in gut microbial diversity and composition between 50 SZ subjects and 50 healthy matched subjects in Zhejiang, China via targeted next-generation sequencing (16S rRNA amplicon). RESULTS: Accordingly, the alpha diversity indices (observed species index, Shannon index, and Simpson index) of the gut microbiome in the healthy control group were higher than those in the SZ group. Additionally, principal coordinate analysis and non-metric multidimensional scaling of beta diversity revealed that patients with SZ clustered more tightly than healthy controls. At the phylum level, we found that the abundance of Bacteroidetes and Proteobacteria in the SZ group was significantly increased. At the genus level, the relative abundances of Prevotella, Parabacteroides, and Sutterella were significantly higher, whereas the abundances of Faecalibacterium, Blautia, Lachnospira, Clostridium, Ruminococcus, and Coprococcus were lower than those in the healthy control group. Further analyses revealed that Succinivibrio, Megasphaera, and Nesterenkonia may serve as potential biomarkers for distinguishing patients with SZ from those in the control cohort. CONCLUSIONS: This study profiled differences in gut microbiome diversity, taxonomic composition, and function between SZ and healthy cohorts, and the insights from this research could be used to develop targeted next-generation sequencing-based diagnoses for SZ.


Subject(s)
Gastrointestinal Microbiome , Schizophrenia , Humans , Gastrointestinal Microbiome/genetics , RNA, Ribosomal, 16S/genetics , Cohort Studies , China
8.
Front Neurosci ; 16: 913042, 2022.
Article in English | MEDLINE | ID: mdl-35645714

ABSTRACT

Dexmedetomidine, as an α2-adrenoceptor agonist, plays anti-sympathetic, sedative and analgesic roles in perioperative period. Also, dexmedetomidine can reduce the minimal alveolar concentration (MAC) of sevoflurane and the risk of postoperative cognitive dysfunction (POCD) induced by sevoflurane anesthesia. But so far, the electroencephalogram (EEG) mechanism of dexmedetomidine deepening sevoflurane anesthesia is not clear. In this study, by analyzing the changes of the power spectrum and bicoherence spectrum of EEG before and after dexmedetomidine infusion, the EEG mechanism of dexmedetomidine deepening sevoflurane anesthesia was studied. We analyzed dexmedetomidine-induced changes in power spectrum and bicoherence spectrum in 23 patients under sevoflurane anesthesia. After anesthesia induction, the sevoflurane concentration was maintained at 0.8 MAC for 15 min, and then dexmedetomidine was administered at a loading dose of 0.8 µg/kg in 10 min, followed by a maintenance rate of 0.5 µg⋅kg-1⋅h-1. Frontal EEG data from 5 min before and 10 min after dexmedetomidine infusion were compared. After dexmedetomidine infusion, the mean α power peak decreased from 6.09 to 5.43 dB and shifted to a lower frequency, the mean θ bicoherence peak increased from 29.57 to 41.25% and shifted to a lower frequency, and the median α bicoherence peak increased from 41.49 to 46.36% and shifted to a lower frequency. These results demonstrate that dexmedetomidine deepens sevoflurane anesthesia, and enhances α and θ bicoherences while shifting peak values of these bands to lower frequencies through regulating thalamo-cortical reverberation networks probably.

9.
BMC Geriatr ; 22(1): 200, 2022 03 14.
Article in English | MEDLINE | ID: mdl-35287583

ABSTRACT

BACKGROUND: Perioperative neurocognitive disorders (PND) are common complications of major surgery among elderly patients, remarkably decreasing patients' life quality. Platelet count has been proved to be an essential factor in inflammation. However, as far as we know, the relationship between platelet count and PND is not clear yet in the orthopedic area. PND could be a long-term disease, which sometimes lasts for several years, and it is meaningful to find a biomarker of PND at the early stage. Thus, we designed this study to find out the association between perioperative platelet count and occurrence of PND, and determine whether preoperative platelet count could be a biomarker of the early stage of PND. METHODS: A prospective observational study was performed on the patients who would take total knee arthroplasty or total hip arthroplasty. Their peripheral platelets were counted by blood routine examination 1 day before and 3 days after the surgery. And we assessed their neurocognitive functions 1 day before and 3 days after the surgery. These data were recorded and analyzed to find out the relationship between platelet count and the occurrence of PND. RESULTS: Eventually, 70 patients finished the whole process, and 14 of them developed PND. The median preoperative platelet count in the PND group was significantly higher than that in the non-PND group (239 vs 168 × 10^9/L, p = 0.009). Preoperative platelet count was an independent risk factor for PND (odds ratio = 1.014, 95% confidence interval [CI] 1.000-1.027, P = 0.043) in the logistic multivariable regression, while the area under the curve of the receiver operating characteristic curve of the prediction model was 0.796 (95% CI 0.676-0.916). CONCLUSIONS: The higher preoperative and postoperative level of platelet count in the peripheral blood were associated with the early stage of PND, and preoperative platelet count could be a potential predictor of the early stage of PND in patients undergoing major orthopedic surgeries. TRIAL REGISTRATION: Chinese Clinical Trial Registry: ChiCTR2000033001 , registration date: 17 May 2020.


Subject(s)
Neurocognitive Disorders , Orthopedic Procedures , Aged , Humans , Neurocognitive Disorders/epidemiology , Orthopedic Procedures/adverse effects , Platelet Count , Postoperative Complications/diagnosis , Postoperative Complications/epidemiology , Postoperative Complications/etiology , Prospective Studies , Risk Factors
10.
Perioper Med (Lond) ; 10(1): 44, 2021 Dec 09.
Article in English | MEDLINE | ID: mdl-34879867

ABSTRACT

BACKGROUND: Although dexmedetomidine (Dex) is known to reduce bispectral index (BIS) values and propofol dosage, there is little information regarding raw electroencephalography (EEG) changes related to Dex deepening of propofol general anesthesia (GA). This study investigated the Dex effects on propofol GA via analysis of EEG changes. METHODS: A study cohort of 21 surgical patients (age range, 20-60 years) categorized as American Society of Anesthesiologists (ASA) class I or II was enrolled. We used time-varying spectral and bicoherence methods to compare electroencephalogram signatures 5 min before versus 10 min after intravenous Dex injection under propofol GA. The means and medians are reported with 95% confidence intervals (CIs) and inter-quartile ranges (IQRs), respectively. RESULTS: Dex augmented the slow waves power and theta (θ) oscillation bicoherence peak from a mean (95% CI) of 22.1% (19.0, 25.2) to 25.2% (21.8, 28.6). Meanwhile, Dex reduced alpha (α) peak power and bicoherence from 3.5 dB (1.0, 6.0) and 41.5% (34.0, 49.0) to 1.7 dB (- 0.6, 4.0) and 35.4% (29.0, 41.8), respectively, while diminishing the median frequency of α oscillation peak values and the mean frequency of α peaks in bicoherence spectra from 12.0 Hz (IQR 11.2, 12.6) and 11.7 Hz (11.3, 12.2) to 11.1 Hz (IQR 10.3, 11.8) and 11.2 Hz (10.9, 11.6), respectively. CONCLUSIONS: Profound EEG changes support the supposition that Dex enhances propofol-induced GA from a moderate to a deeper state. The present findings provide a theoretical basis and reference regarding protocols aimed at reducing anesthetic/sedative dosage while maintaining sufficient depth of GA. CLINICAL TRIAL REGISTRATION: ChiCTR, ChiCTR1900026955 . Registered on 27 October 2019.

11.
Anal Chem ; 93(37): 12556-12564, 2021 09 21.
Article in English | MEDLINE | ID: mdl-34477357

ABSTRACT

Scattering photon burst counting (SPBC) is a single-particle detection method, which is based on measuring scattering photon bursting of single nanoparticles through a detection volume of <1 fL. Although SPBC has been used for bioassays and analysis of nanoparticles, it is necessary to establish its theoretical model and develop a new detection mode in order to further enhance its sensitivity and enlarge its application fields. In this paper, we proposed a theoretical model for the confocal SPBC method and developed a novel SPBC detection mode using the fast objective scanning technique. The computer simulations and experiments documented that this model well describes the relation between photon counts and experimental parameters (such as nanoparticle concentration and diameter, temperature, and viscosity). Based on this model, we developed a novel SPBC detection mode by using the fast objective scanning technique. Compared to the current confocal SPBC method, the sensitivity of this new method was significantly increased due to the significantly increased photon counts per sampling time, the linear detection range is from 0.9 to 90 pM, and the limit of detection is reduced to 40 fM for 30 nm gold nanoparticles. Furthermore, this new method was successfully applied to determine the enzyme activity of caspase-3 and evaluate the inhibition effectiveness of some inhibitors.


Subject(s)
Gold , Metal Nanoparticles , Models, Theoretical , Photons
12.
Anal Chem ; 93(28): 9752-9759, 2021 07 20.
Article in English | MEDLINE | ID: mdl-34240602

ABSTRACT

Single-particle catalytic analysis plays an important role to understand the catalytic mechanism of nanocatalysts. Currently, some methods are used to study the relationship between single-particle catalytic activity and morphology. However, there is still lack of a simple and rapid analysis method for evaluating the catalytic activity of an individual nanocatalyst that freely moves in solution. Here, we proposed a novel single-particle catalytic analysis method for investigating the catalytic activity of a free nanocatalyst. Its working principle is based on the photon burst counting analysis on fluorescent catalytic products of an individual nanocatalyst combined with a microfluidic chip. In this study, we used the reduction reaction of resazurin (RZ) to resorufin (RF) catalyzed by gold nanoparticles (GNPs) as a model. When nonfluorescent RZ molecules in one microchannel of the microfluidic chip mixed with the GNPs flowing in another channel under the control of flow rates, each individual photon burst from the catalytic product RF by GNPs was measured in real time with a constructed flow single-particle catalytic analysis (SPCA) system. With the method, the obtained intensity of each photon burst reflects the capacity of a particle to catalyze RZ molecules into RF(s). The number of photon burst within sampling time reflects the particle number of GNPs with catalytic activity. The experimental conditions including the mixing mode of the nanocatalyst and the substrate, the flow rate, RZ concentration, and detection time were optimized. Finally, the method was successfully used to study the catalytic activity of GNPs with different sizes and morphologies.


Subject(s)
Gold , Metal Nanoparticles , Catalysis , Microfluidics , Photons
13.
Anal Chem ; 93(27): 9329-9336, 2021 07 13.
Article in English | MEDLINE | ID: mdl-34171193

ABSTRACT

Site-specific incorporation of unnatural amino acids (UAAs) into target proteins (UAA-proteins) provides the unprecedented opportunities to study cell biology and biomedicine. However, it is a big challenge to in situ quantitatively determine the expression level of UAA-proteins due to serious interferences from autofluorescence, background scattering, and different viscosity in living cells. Here, we proposed a novel single nanoparticle spectroscopy method, differenced resonance light scattering correlation spectroscopy (D-RLSCS), to measure the UAA-proteins in single living cells. The D-RLSCS principle is based on the simultaneous measurement of the resonance scattering light fluctuation of a single gold nanoparticle (GNP) in two detection channels irradiated by two coaxial laser beams and then autocorrelation analysis on the differenced fluctuation signals between two channels. D-RLSCS can avoid the interferences from intracellular background scattering and provide the concentration and rotational and translational diffusion information of GNPs in solution or in living cells. Furthermore, we proposed a parameter, the ratiometric diffusion time and found that this parameter is proportional to the square of particle size. The theoretical and experimental results demonstrated that the ratiometric diffusion time was not influenced by the intracellular viscosity. This method was successfully applied for in situ quantification of the UAA-protein within single living cells based on the increase in the ratiometric diffusion time of nanoprobes bound with proteins. Using UAA-EGFP (enhanced green fluorescent protein) as a model, we observed the significant difference in the UAA-protein concentrations at different positions in single living cells.


Subject(s)
Gold , Metal Nanoparticles , Amino Acids , Light , Spectrum Analysis
14.
Analyst ; 146(11): 3623-3632, 2021 Jun 07.
Article in English | MEDLINE | ID: mdl-33929479

ABSTRACT

DNA methylation is a critical part of epigenetics and plays a vital role in maintaining normal cell function, genetic imprinting, and human tumorigenesis. Thus, it is important to develop a sensitive method for the determination of DNA methyltransferase (MTase) activity. Here, we present a simple and sensitive method based on single molecule fluorescence correlation spectroscopy (FCS) and polystyrene polymer dots (PS Pdots) for the quantitative detection of DNA adenine methylation (Dam) MTase activity and its inhibitor screening in homogeneous solution without separation. Its principle is based on the measurement of the characteristic diffusion time (τD) of unmethylated and methylated DNA-fluorescent probes by FCS. A hairpin DNA probe including the 5'-GATC-3' sequence is used by doubly labelling fluorophore Alexa Fluor 488 (Alexa 488) and biotin at the 5'- and 3'-terminus, respectively. Dam MTase catalyzed the methylation of the sequence of 5'-GATC-3', and DpnI cleaved the sequence of 5'-G-Am-TC-3'. Streptavidin conjugated PS Pdots were used to react with DNA probes without methylation to further increase the difference in τD values between methylated and unmethylated DNA-Alexa 488 probes. We used the FCS method to measure the τD values of DNA-Alexa 488 probes and further obtained the activity of Dam MTase. It is found that the τD value of the methylated DNA probe is negatively correlated with the logarithm of Dam MTase concentration in the range from 0.025 U mL-1 to 3 U mL-1. The detection limit is as low as 0.025 U mL-1. Furthermore, we evaluated the inhibition effect of drug-related DNA methylation and the half-maximal inhibitory concentration (IC50) value is consistent with a previous study. The results demonstrated that our proposed method will become a promising platform for the determination of Dam MTase activity and inhibitor screening.


Subject(s)
Biosensing Techniques , Site-Specific DNA-Methyltransferase (Adenine-Specific) , DNA/genetics , DNA Methylation , Humans , Polymers , Polystyrenes , Site-Specific DNA-Methyltransferase (Adenine-Specific)/genetics , Site-Specific DNA-Methyltransferase (Adenine-Specific)/metabolism
15.
Analyst ; 146(8): 2581-2590, 2021 Apr 26.
Article in English | MEDLINE | ID: mdl-33899064

ABSTRACT

The mitogen-activated protein kinase (MAPK) pathway is a major module for cellular signal transduction. The dysregulation of the MAPK pathway has been involved in the pathogenesis of multiple diseases ranging from cancers to chronic inflammations. So far, we have not fully understood the influences of external factors and signaling networks on the MAPK pathway due to the lack of in situ methods for simultaneous detection of multiple kinases in the pathway in living cells. Herein, we present a new strategy for in situ and simultaneously monitoring MAPK pathway kinases in single living cells combining multi-channel fluorescence correlation spectroscopy (FCS) with affinity fluorescent probes. We chose rapidly growing fibrosarcoma kinase (RAF), mitogen-activated protein kinase (MEK), and extracellular signal-regulated kinase (ERK) as representative members in the MAPK pathway. We designed and synthesized three fluorescent affinity probes and experimental results demonstrated that the three probes specifically targeted endogenous BRAF, MEK1/2, and ERK1/2 in living cells. Based on the multi-channel FCS system, we studied the influences of biological substances, drugs and oxidative stress on the activities of endogenous MAPK kinases and the cross-talk between the MAPK and PI3K-mTOR pathways. We have found that serum, sorafenib, and hydrogen peroxide can regulate multiple MAPK kinases and the effects of external stimuli can transmit to the MAPK pathway; furthermore, we have observed that the MAPK pathway can be activated by modulating the PI3K-mTOR pathway. Our results illustrated the complexity of a cellular signal network and the necessity of in situ and simultaneous determination of biomolecules in living cells.


Subject(s)
Extracellular Signal-Regulated MAP Kinases , Mitogen-Activated Protein Kinase Kinases , Spectrum Analysis , Extracellular Signal-Regulated MAP Kinases/metabolism , Mitogen-Activated Protein Kinase Kinases/metabolism , Signal Transduction
17.
J Am Chem Soc ; 142(37): 15638-15643, 2020 09 16.
Article in English | MEDLINE | ID: mdl-32876439

ABSTRACT

Artificial aquaporins are synthetic molecules that mimic the structure and function of natural aquaporins (AQPs) in cell membranes. The development of artificial aquaporins would provide an alternative strategy for treatment of AQP-related diseases. In this report, an artificial aquaporin has been constructed from an amino-terminated tubular molecule, which operates in a unimolecular mechanism. The artificial channel can work in cell membranes with high water permeability and selectivity rivaling those of AQPs. Importantly, the channel can restore wound healing of the cells that contain function-lost AQPs.


Subject(s)
Aquaporins/pharmacology , Wound Healing/drug effects , Aquaporins/chemistry , Hep G2 Cells , Human Umbilical Vein Endothelial Cells/drug effects , Humans , Models, Molecular , Molecular Dynamics Simulation , Molecular Structure , Single Molecule Imaging
18.
Anal Chem ; 92(10): 7020-7027, 2020 05 19.
Article in English | MEDLINE | ID: mdl-32340449

ABSTRACT

The drug-target protein interaction is the basis of drug screening and precise therapy in modern clinical medicine. How to acquire the information about the drug-target protein interaction in single living cell is a great challenge due to the shortage of efficient methods. Here we propose a new strategy for in situ studying the drug-target protein interaction in single living cells based on the competition of candidate drugs to the fluorescent probe-target complexes and fluorescence correlation spectroscopy (FCS) with a microfluidic chip. In this study, we used ABL kinase (target) as a model and synthesized a fluorescent probe (Cy3-dasatinib) with an affinity to the target using ABL inhibitor dasatinib as a precursor. We systematically investigated the association of the probe with targets and the dissociation of the drug-target complexes in the presence of candidate drug. We presented a new parameter IC50 (τD) to assess the inhibitory effect of drugs on the basis of the changes in the characteristic diffusion time (τD) and the binding ratio (y) of fluorescent probes during the drug competition process in living cells. We found a remarkable difference of IC50 (τD) values in living cells and in solutions, suggesting it is quite necessary to evaluate the drug-target interactions in living cells. Compared with current methods, our approach can be used to in situ and real-time study the drug-target interaction in living cells, and it may become a promising and universal tool for in situ drug research at molecular level.


Subject(s)
Antineoplastic Agents/chemistry , Carbocyanines/chemistry , Dasatinib/chemistry , Fluorescent Dyes/chemistry , Protein Kinase Inhibitors/chemistry , Proto-Oncogene Proteins c-abl/antagonists & inhibitors , Antineoplastic Agents/pharmacology , Dasatinib/pharmacology , Humans , Molecular Structure , Protein Kinase Inhibitors/pharmacology , Proto-Oncogene Proteins c-abl/metabolism , Spectrometry, Fluorescence
19.
ACS Omega ; 4(25): 21161-21168, 2019 Dec 17.
Article in English | MEDLINE | ID: mdl-31867509

ABSTRACT

The assembly of noble-metal core-satellite (CS) nanostructures is an appealing means to control their plasmonic properties for their applications such as surface-enhanced fluorescence or Raman scattering. However, till now there is a lack of some rapid or convenient methods to construct stable CS nanostructures. Here, we proposed a "clicked-to-assembly" strategy based on the fast and specific "click chemistry" reaction between trans-cyclooctene (TCO) and 1,2,4,5-tetrazine (Tz). The CS nanostructures were constructed within 8 min by simple mixing of TCO- or Tz-modified nanoparticles (TCO-NPs or Tz-NPs) without any catalysts or heating required. Transmission electron microscopy experiments show that the constructed CS nanostructures are uniform, and particularly the number of "satellite" nanoparticles in the core surface is controllable by simply adjusting the feeding ratio of TCO-NPs or Tz-NPs in the reaction. The strong surface plasmon coupling effect (SPCE) was observed in these CS nanostructures, which was dependent on the coverage degree, size and composition of the satellite, and core NPs. The nanostructures with tuned surface plasmon resonance (SPR) effect were tried for the surface-enhanced fluorescence in living cells. Such well-defined CS nanostructures could potentially serve as efficient SPR-enhanced fluorescent probes as diagnostics or biomedical imaging agents in nanomedicine.

20.
Anal Chem ; 90(11): 6929-6935, 2018 06 05.
Article in English | MEDLINE | ID: mdl-29732881

ABSTRACT

Chemiluminescence (CL) is a promising bioimaging method due to no interferences of light source and autofluorescence. However, compared to fluorescent emission, most CL reactions show short emission time and wavelength and weak emission intensity, which limit their applications in in vivo imaging. Here, we report mimic-enzyme catalytic CL polymer dots (hemin-Pdots) consisting of hemin and fluorescent conjugated polymer based on chemiluminescence resonance energy transfer. Hemin-Pdots show about 700× enhanced CL and over 10 h light emission in the presence of CL substrates and H2O2. These properties are mainly due to high-catalytic activity of hemin-Pdots and slow-diffusion-controlled heterogeneous reaction. Hemin-Pdots also possess excellent biocompatibility, good stability, emission wavelength redshift, and ultrasensitive response to reactive oxygen species (ROS), and they were successfully used for real-time imaging ROS levels in the peritoneal cavity and normal and tumor tissues of mice. Hemin-Pdots as new CL probes have wide applications in bioassays, bioimaging, and photodynamic therapy.


Subject(s)
Luminescence , Optical Imaging , Polymers/chemistry , Quantum Dots/chemistry , Reactive Oxygen Species/analysis , Animals , Catalysis , Cell Line, Tumor , Female , HEK293 Cells , Humans , Mice , Mice, Nude , Neoplasms, Experimental/diagnostic imaging , Neoplasms, Experimental/metabolism , Reactive Oxygen Species/metabolism
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