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1.
Clin Transl Oncol ; 2024 Sep 06.
Article in English | MEDLINE | ID: mdl-39240303

ABSTRACT

PURPOSE: The aim of this study is to investigate the expression of TET3 in prostate cancer and its effect on the efficacy of anti-androgen therapy (ADT). METHODS: The expression of TET3 in 1965 cases of prostate cancer and 493 cases of normal prostate tissues were analyzed. The CIBERSORT algorithm evaluated the abundance of 22 tumor-infiltrating immune cells in 497 prostate cancers. Subsequently, the expression of TET3 in prostate cancer TAMs was analyzed using 21,292 cells from single-cell RNA sequencing (scRNAseq). In addition, the trajectory of the differentiation process was reconstructed based on pseudotime analysis. Sensitivity prediction of prostate cancers to ADT was evaluated based on GDSC2 and CTRP databases. Another dataset GSE111177 was employed for further analysis. RESULTS: TET3 was over-expressed in prostate cancer, and the expression of TET3 in metastatic prostate cancer was higher than that in non-metastatic prostate cancer. The scRNAseq analysis of prostate cancer showed that TET3 was mainly expressed in TAM. TET3 expressed in early and active TAMs, with the activation of signaling pathways such as energy metabolism, cell communication, and cytokine production. Prostate cancer in TET3 high expression group was more sensitive to ADT drugs such as Bicalutamide and AZD3514, and was also more sensitive to chemotherapy drugs such as Cyclophosphamide, Paclitaxel, and Vincristine, and MAPK pathway inhibitors of Docetaxel and Dabrafenib. CONCLUSIONS: The efficacy of ADT in prostate cancer is related to the expression of TET3 in TAMs, and TET3 may be a potential therapeutic target for coordinating ADT.

2.
J Neural Eng ; 21(5)2024 Sep 04.
Article in English | MEDLINE | ID: mdl-39230033

ABSTRACT

Objective.With prolonged life expectancy, the incidence of memory deficits, especially in Alzheimer's disease (AD), has increased. Although multiple treatments have been evaluated, no promising treatment has been found to date. Deep brain stimulation (DBS) of the fornix area was explored as a possible treatment because the fornix is intimately connected to memory-related areas that are vulnerable in AD; however, a proper imaging biomarker for assessing the therapeutic efficiency of forniceal DBS in AD has not been established.Approach.This study assessed the efficacy and safety of DBS by estimating the optimal intersection volume between the volume of tissue activated and the fornix. Utilizing a gold-electroplating process, the microelectrode's surface area on the neural probe was increased, enhancing charge transfer performance within potential water window limits. Bilateral fornix implantation was conducted in triple-transgenic AD mice (3 × Tg-AD) and wild-type mice (strain: B6129SF1/J), with forniceal DBS administered exclusively to 3 × Tg-AD mice in the DBS-on group. Behavioral tasks, diffusion tensor imaging (DTI), and immunohistochemistry (IHC) were performed in all mice to assess the therapeutic efficacy of forniceal DBS.Main results.The results illustrated that memory deficits and increased anxiety-like behavior in 3 × Tg-AD mice were rescued by forniceal DBS. Furthermore, forniceal DBS positively altered DTI indices, such as increasing fractional anisotropy (FA) and decreasing mean diffusivity (MD), together with reducing microglial cell and astrocyte counts, suggesting a potential causal relationship between revised FA/MD and reduced cell counts in the anterior cingulate cortex, hippocampus, fornix, amygdala, and entorhinal cortex of 3 × Tg-AD mice following forniceal DBS.Significance.The efficacy of forniceal DBS in AD can be indicated by alterations in DTI-based biomarkers reflecting the decreased activation of glial cells, suggesting reduced neural inflammation as evidenced by improvements in memory and anxiety-like behavior.


Subject(s)
Alzheimer Disease , Deep Brain Stimulation , Diffusion Tensor Imaging , Disease Models, Animal , Fornix, Brain , Mice, Transgenic , Animals , Alzheimer Disease/therapy , Alzheimer Disease/diagnostic imaging , Alzheimer Disease/psychology , Deep Brain Stimulation/methods , Mice , Diffusion Tensor Imaging/methods , Fornix, Brain/diagnostic imaging , Biomarkers , Male , Treatment Outcome
3.
Cardiovasc Toxicol ; 24(9): 889-903, 2024 Sep.
Article in English | MEDLINE | ID: mdl-39138741

ABSTRACT

Aortic aneurysm and dissection (AAD) is a cardiovascular disease that poses a severe threat to life and has high morbidity and mortality rates. Clinical and animal-based studies have irrefutably shown that fluoroquinolones, a commonly prescribed antibiotic for treating infections, significantly increase the risk of AAD. Despite this, the precise mechanism by which fluoroquinolones cause AAD remains unclear. Therefore, this study aims to investigate the molecular mechanism and role of Ciprofloxacin definitively-a type of fluoroquinolone antibiotic-in the progression of AAD. Aortic transcriptome data were collected from GEO datasets to detect the genes and pathways expressed differently between healthy donors and AAD patients. Human primary Vascular Smooth Muscle Cells (VSMCs) were isolated from the aorta. After 72 h of exposure to 110ug/ml Ciprofloxacin or 100 nmol/L AngII, either or combined, the senescent cells were identified through SA-ß-gal staining. MitoTracker staining was used to examine the morphology of mitochondria in each group. Cellular Reactive Oxygen Species (ROS) levels were measured using MitoSox and DCFH-DA staining. Western blot assay was performed to detect the protein expression level. We conducted an analysis of transcriptome data from both healthy donors and patients with AAD and found that there were significant changes in cellular senescence-related signaling pathways in the latter group. We then isolated and identified human primary VSMCs from healthy donors (control-VSMCs) and patients' (AAD-VSMCs) aortic tissue, respectively. We found that VSMCs from patients exhibited senescent phenotype as compared to control-VSMCs. The higher levels of p21 and p16 and elevated SA-ß-gal activity demonstrated this. We also found that pretreatment with Ciprofloxacin promoted angiotensin-II-induced cellular senescence in control-VSMCs. This was evidenced by increased SA-ß-gal activity, decreased cell proliferation, and elevation of p21 and p16 protein levels. Additionally, we found that Angiotensin-II (AngII) induced VSMC senescence by promoting ROS generation. We used DCFH-DA and mitoSOX staining to identify that Ciprofloxacin and AngII pretreatment further elevated ROS levels than the vehicle or alone group. Furthermore, JC-1 staining showed that mitochondrial membrane potential significantly declined in the Ciprofloxacin and AngII combination group compared to others. Compared to the other three groups, pretreatment of Ciprofloxacin plus AngII could further induce mitochondrial fission, demonstrated by mitoTracker staining and western blotting assay. Mechanistically, we found that Ciprofloxacin impaired the balance of mitochondrial fission and fusion dynamics in VSMCs by suppressing the phosphorylation of AMPK signaling. This caused mitochondrial dysfunction and ROS generation, thereby elevating AngII-induced cellular senescence. However, treatment with the AMPK activator partially alleviated those effects. Our data indicate that Ciprofloxacin may accelerate AngII-induced VSMC senescence through modulating AMPK/ROS signaling and, subsequently, hasten the progression of AAD.


Subject(s)
AMP-Activated Protein Kinases , Angiotensin II , Aortic Dissection , Cellular Senescence , Ciprofloxacin , Muscle, Smooth, Vascular , Myocytes, Smooth Muscle , Reactive Oxygen Species , Signal Transduction , Humans , Cellular Senescence/drug effects , Muscle, Smooth, Vascular/drug effects , Muscle, Smooth, Vascular/pathology , Muscle, Smooth, Vascular/metabolism , Muscle, Smooth, Vascular/enzymology , Aortic Dissection/chemically induced , Aortic Dissection/pathology , Aortic Dissection/enzymology , Aortic Dissection/metabolism , Signal Transduction/drug effects , Reactive Oxygen Species/metabolism , Myocytes, Smooth Muscle/drug effects , Myocytes, Smooth Muscle/pathology , Myocytes, Smooth Muscle/enzymology , Myocytes, Smooth Muscle/metabolism , Angiotensin II/toxicity , Cells, Cultured , Ciprofloxacin/pharmacology , AMP-Activated Protein Kinases/metabolism , Case-Control Studies , Aortic Aneurysm/chemically induced , Aortic Aneurysm/pathology , Aortic Aneurysm/metabolism , Aortic Aneurysm/enzymology , Male , Middle Aged , Oxidative Stress/drug effects
4.
Neurospine ; 21(2): 665-675, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38955536

ABSTRACT

OBJECTIVE: This study aims to overcome challenges in lumbar spine imaging, particularly lumbar spinal stenosis, by developing an automated segmentation model using advanced techniques. Traditional manual measurement and lesion detection methods are limited by subjectivity and inefficiency. The objective is to create an accurate and automated segmentation model that identifies anatomical structures in lumbar spine magnetic resonance imaging scans. METHODS: Leveraging a dataset of 539 lumbar spinal stenosis patients, the study utilizes the residual U-Net for semantic segmentation in sagittal and axial lumbar spine magnetic resonance images. The model, trained to recognize specific tissue categories, employs a geometry algorithm for anatomical structure quantification. Validation metrics, like Intersection over Union (IOU) and Dice coefficients, validate the residual U-Net's segmentation accuracy. A novel rotation matrix approach is introduced for detecting bulging discs, assessing dural sac compression, and measuring yellow ligament thickness. RESULTS: The residual U-Net achieves high precision in segmenting lumbar spine structures, with mean IOU values ranging from 0.82 to 0.93 across various tissue categories and views. The automated quantification system provides measurements for intervertebral disc dimensions, dural sac diameter, yellow ligament thickness, and disc hydration. Consistency between training and testing datasets assures the robustness of automated measurements. CONCLUSION: Automated lumbar spine segmentation with residual U-Net and deep learning exhibits high precision in identifying anatomical structures, facilitating efficient quantification in lumbar spinal stenosis cases. The introduction of a rotation matrix enhances lesion detection, promising improved diagnostic accuracy, and supporting treatment decisions for lumbar spinal stenosis patients.

5.
Bioorg Chem ; 147: 107328, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38583248

ABSTRACT

Discovering novel NDM-1 inhibitors is an urgent task for treatment of 'superbug' infectious diseases. In this study, we found that naturally occurring houttuynin and its sulfonate derivatives might be effective NDM-1 inhibitors with novel mechanism, i.e. the attribute of partially covalent inhibition of sulfonate derivatives of houttuynin against NDM-1. Primary structure-activity relationship study showed that both the long aliphatic side chain and the warhead of aldehyde group are vital for the efficiency against NDM-1. The homologs with longer chains (SNH-2 to SNH-5) displayed stronger inhibitory activities with IC50 range of 1.1-1.5 µM, while the shorter chain the weaker inhibition. Further synergistic experiments in cell level confirmed that all these 4 compounds (at 32 µg/mL) recovered the antibacterial activity of meropenem (MER) against E. coli BL21/pET15b-blaNDM-1.


Subject(s)
Anti-Bacterial Agents , Dose-Response Relationship, Drug , Escherichia coli , Microbial Sensitivity Tests , Structure-Activity Relationship , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/chemical synthesis , Escherichia coli/drug effects , Escherichia coli/enzymology , Molecular Structure , beta-Lactamases/metabolism , beta-Lactamase Inhibitors/pharmacology , beta-Lactamase Inhibitors/chemistry , beta-Lactamase Inhibitors/chemical synthesis , Biological Products/pharmacology , Biological Products/chemistry , Biological Products/chemical synthesis , Humans , Escherichia coli Proteins
6.
Anim Cells Syst (Seoul) ; 28(1): 84-92, 2024.
Article in English | MEDLINE | ID: mdl-38440122

ABSTRACT

Aortic aneurysm/dissection (AAD) poses a life-threatening cardiovascular emergency with complex mechanisms and a notably high mortality rate. Zebrafish (Danio rerio) serve as valuable models for AAD due to the conservation of their three-layered arterial structure and genome with that of humans. However, the existing studies have predominantly focused on larval zebrafish, leaving a gap in our understanding of adult zebrafish. In this study, we utilized ß-Aminopropionic Nitrile (BAPN) impregnation to induce AAD in both larval and adult zebrafish. Following induction, larval zebrafish exhibited a 28% widening of the dorsal aortic diameter (p < 0.0004, n = 10) and aortic arch malformations, with a high malformation rate of 75% (6/8). Conversely, adult zebrafish showed a 41.67% (5/12) mortality rate 22 days post-induction. At this time point, the dorsal aortic area had expanded by 2.46 times (p < 0.009), and the vessel wall demonstrated significant thickening (8.22 ± 2.23 µM vs. 26.38 ± 10.74 µM, p < 0.05). Pathological analysis revealed disruptions in the smooth muscle layer, contributing to a 58.33% aneurysm rate. Moreover, the expression levels of acta2, tagln, cnn1a, and cnn1b were decreased, indicating a weakened contractile phenotype. Transcriptome sequencing showed a significant overlap between the molecular features of zebrafish tissues post-BAPN treatment and those of AAD patients. Our findings present a straightforward and practical method for generating AAD models in both larval and adult zebrafish using BAPN.

7.
Heliyon ; 9(9): e19505, 2023 Sep.
Article in English | MEDLINE | ID: mdl-37809895

ABSTRACT

The cellular senescence of mesenchymal stem cells (MSCs) limits their application in regenerative medicine. This study aimed to clarify the role of TNF receptor-associated factor 3 interacting protein 2 (TRAF3IP2), a pro-inflammatory cytoplasmic adaptor protein, in regulating MSC senescence and to explore the potential mechanisms. Methods: MSC senescence was determined by senescence-associated ß-galactosidase (SA-ß-gal) staining. The expression of TRAF3IP2 and senescence-related proteins was detected by Western blotting. The nicotinamide adenine dinucleotide (NAD+) level and nicotinamide phosphoribosyl transferase (NAMPT) expression in MSCs was measured. Results: Compared with that in MSCs isolated from young donors (YMSCs), the expression of TRAF3IP2 was greatly increased in MSCs derived from aged donors (AMSCs). Overexpression of TRAF3IP2 accelerated YMSC senescence whereas downregulation significantly rescued cellular senescence. The protein level of NAMPT and the level of NAD+ were significantly decreased in AMSCs compared with YMSCs. Mechanistically, TRAF3IP2 induced MSC senescence via downregulation of NAMPT expression and NAD + level by inhibiting the AMPK signaling pathway. These effects were partially reversed by treatment with an AMPK or NAMPT activator. Conclusion: We revealed that TRAF3IP2 accelerated MSC senescence via downregulation of NAMPT-mediated NAD biosynthesis by mediation of the AMPK pathway, highlighting a novel means to rejuvenate senescent MSCs.

8.
Neurobiol Stress ; 26: 100566, 2023 Sep.
Article in English | MEDLINE | ID: mdl-37664874

ABSTRACT

Major depressive disorder (MDD), a common psychiatric condition, adversely affects patients' moods and quality of life. Despite the development of various treatments, many patients with MDD remain vulnerable and inadequately controlled. Since anhedonia is a feature of depression and there is evidence of leading to metabolic disorder, deep brain stimulation (DBS) to the nucleus accumbens (NAc) might be promising in modulating the dopaminergic pathway. To determine whether NAc-DBS alters glucose metabolism via mitochondrial alteration and neurogenesis and whether these changes increase neural plasticity that improves behavioral functions in a chronic social defeat stress (CSDS) mouse model. The Lab-designed MR-compatible neural probes were implanted in the bilateral NAc of C57BL/6 mice with and without CSDS, followed by DBS or sham stimulation. All animals underwent open-field and sucrose preference testing, and brain resting-state functional MRI analysis. Meanwhile, we checked the placement of neural probes in each mouse by T2 images. By confirming the placement location, mice with incorrect probe placement (the negative control group) showed no significant therapeutic effects in behavioral performance and functional connectivity (FC) after receiving electrical stimulation and were excluded from further analysis. Western blotting, seahorse metabolic analysis, and electron microscopy were further applied for the investigation of NAc-DBS. We found NAc-DBS restored emotional deficits in CSDS-subjected mice. Concurrent with behavioral amelioration, the CSDS DBS-on group exhibited enhanced FC in the dopaminergic pathway with increased expression of BDNF- and NeuN-positive cells increased dopamine D1 receptor, dopamine D2 receptors, and TH in the medial prefrontal cortex, NAc, ventral hippocampus, ventral tegmental area, and amygdala. Increased pAMPK/total AMPK and PGC-1α levels, functions of oxidative phosphorylation, and mitochondrial biogenesis were also observed after NAc-DBS treatment. Our findings demonstrate that NAc-DBS can promote BDNF expression, which alters FC and metabolic profile in the dopaminergic pathway, suggesting a potential strategy for ameliorating emotional processes in individuals with MDD.

9.
Ecotoxicol Environ Saf ; 263: 115373, 2023 Sep 15.
Article in English | MEDLINE | ID: mdl-37619400

ABSTRACT

Fine particulate matter (PM2.5) is thought to exacerbate Parkinson's disease (PD) in the elderly, and early detection of PD progression may prevent further irreversible damage. Therefore, we used diffusion tensor imaging (DTI) for probing microstructural changes after late-life chronic traffic-related PM2.5 exposure. Herein, 1.5-year-old Fischer 344 rats were exposed to clean air (control), high-efficiency particulate air (HEPA)-filtered ambient air (HEPA group), and ambient traffic-related PM2.5 (PM2.5 group, 9.933 ± 1.021 µg/m3) for 3 months. Rotarod test, DTI tractographic analysis, and immunohistochemistry were performed in the end of study period. Aged rats exposed to PM2.5 exhibited motor impairment with decreased fractional anisotropy and tyrosine hydroxylase expression in olfactory and nigrostriatal circuits, indicating disrupted white matter integrity and dopaminergic (DA) neuronal loss. Additionally, increased radial diffusivity and lower expression of myelin basic protein in PM2.5 group suggested ageing progression of demyelination exacerbated by PM2.5 exposure. Significant production of tumor necrosis factor-α was also observed after PM2.5 exposure, revealing potential inflammation of injury to multiple fiber tracts of DA pathways. Microstructural changes demonstrated potential links between PM2.5-induced inflammatory white matter demyelination and behavioral performance, with indication of pre-manifestation of DTI-based biomarkers for early detection of PD progression in the elderly.


Subject(s)
Air Pollution , Demyelinating Diseases , White Matter , Rats , Animals , Diffusion Tensor Imaging , Dopamine , Dust , Particulate Matter/toxicity
10.
Biosensors (Basel) ; 13(2)2023 Feb 13.
Article in English | MEDLINE | ID: mdl-36832031

ABSTRACT

Owing to its capacity to eliminate a long-standing methodological limitation, fiber photometry can assist research gaining novel insight into neural systems. Fiber photometry can reveal artifact-free neural activity under deep brain stimulation (DBS). Although evoking neural potential with DBS is an effective method for mediating neural activity and neural function, the relationship between DBS-evoked neural Ca2+ change and DBS-evoked neural electrophysiology remains unknown. Therefore, in this study, a self-assembled optrode was demonstrated as a DBS stimulator and an optical biosensor capable of concurrently recording Ca2+ fluorescence and electrophysiological signals. Before the in vivo experiment, the volume of tissue activated (VTA) was estimated, and the simulated Ca2+ signals were presented using Monte Carlo (MC) simulation to approach the realistic in vivo environment. When VTA and the simulated Ca2+ signals were combined, the distribution of simulated Ca2+ fluorescence signals matched the VTA region. In addition, the in vivo experiment revealed a correlation between the local field potential (LFP) and the Ca2+ fluorescence signal in the evoked region, revealing the relationship between electrophysiology and the performance of neural Ca2+ concentration behavior. Concurrent with the VTA volume, simulated Ca2+ intensity, and the in vivo experiment, these data suggested that the behavior of neural electrophysiology was consistent with the phenomenon of Ca2+ influx to neurons.


Subject(s)
Calcium , Thalamus , Fluorescence , Thalamus/physiology , Computer Simulation , Electrophysiology/methods
11.
Front Cell Neurosci ; 15: 655305, 2021.
Article in English | MEDLINE | ID: mdl-34149359

ABSTRACT

Administration of 12-(3-adamantan-1-yl-ureido)-dodecanoic acid (AUDA) has been demonstrated to alleviate infarction following ischemic stroke. Reportedly, the main effect of AUDA is exerting anti-inflammation and neovascularization via the inhibition of soluble epoxide hydrolase. However, the major contribution of this anti-inflammation and neovascularization effect in the acute phase of stroke is not completely elucidated. To investigate the neuroprotective effects of AUDA in acute ischemic stroke, we combined laser speckle contrast imaging and optical intrinsic signal imaging techniques with the implantation of a lab-designed cranial window. Forepaw stimulation was applied to assess the functional changes via measuring cerebral metabolic rate of oxygen (CMRO2) that accompany neural activity. The rats that received AUDA in the acute phase of photothrombotic ischemia stroke showed a 30.5 ± 8.1% reduction in the ischemic core, 42.3 ± 15.1% reduction in the ischemic penumbra (p < 0.05), and 42.1 ± 4.6% increase of CMRO2 in response to forepaw stimulation at post-stroke day 1 (p < 0.05) compared with the control group (N = 10 for each group). Moreover, at post-stroke day 3, increased functional vascular density was observed in AUDA-treated rats (35.9 ± 1.9% higher than that in the control group, p < 0.05). At post-stroke day 7, a 105.4% ± 16.4% increase of astrocytes (p < 0.01), 30.0 ± 10.9% increase of neurons (p < 0.01), and 65.5 ± 15.0% decrease of microglia (p < 0.01) were observed in the penumbra region in AUDA-treated rats (N = 5 for each group). These results suggested that AUDA affects the anti-inflammation at the beginning of ischemic injury and restores neuronal metabolic rate of O2 and tissue viability. The neovascularization triggered by AUDA restored CBF and may contribute to ischemic infarction reduction at post-stroke day 3. Moreover, for long-term neuroprotection, astrocytes in the penumbra region may play an important role in protecting neurons from apoptotic injury.

12.
Langmuir ; 37(21): 6406-6413, 2021 Jun 01.
Article in English | MEDLINE | ID: mdl-33999641

ABSTRACT

Evolution of LiMn2O4 mechanical property during charge/discharge cycles is a critical issue because it is closely related to the performance of lithium-ion batteries. Extensive studies have been conducted by first-principles calculations/molecular dynamics simulation at the atomic level and by the nanoindentation technique at the micron scale. In this study, cycling-induced topographic and mechanical evolutions of the LiMn2O4 films are investigated at the nanoscale using the bimodal atomic force microscopy (AFM), which provides a complementary approach to bridge the gap between atomic-level calculation and micron-scale measurement. The topographic change and elastic modulus degradation of the LiMn2O4 films during the charge/discharge cycles are found to occur simultaneously and irreversibly. Moreover, a dramatic decrease in the elastic modulus of the films takes place at the first 10 cycles, which is consistent with the significant loss of the capacity and the change of the Coulombic efficiency measured by the galvanostatic method. By considering the nanoscale phenomena and the macroscopic measurement results, the reasons for the elastic modulus degradation are discussed. This study would be a valuable addition to a better understanding of the degradation mechanisms of this cathode material.

13.
Rev Sci Instrum ; 91(10): 103701, 2020 Oct 01.
Article in English | MEDLINE | ID: mdl-33138593

ABSTRACT

Development of lithium ion batteries with ultrafast charging rate as well as high energy/power densities and long cycle-life is one of the imperative works in the field of batteries. To achieve this goal, it requires not only to develop new electrode materials but also to develop nano-characterization techniques that are capable of investigating the dynamic evolution of the surface/interface morphology and property of fast charging electrode materials during battery operation. Although electrochemical atomic force microscopy (EC-AFM) holds high spatial resolution, its imaging speed is too slow to visualize dynamics occurring on the timescale of minutes. In this article, we present an electrochemical high-speed AFM (EC-HS-AFM), developed by addressing key technologies involving optical detection of small cantilever deflection, dual scanner capable of high-speed and wide-range imaging, and electrochemical cell with three electrodes. EC-HS-AFM imaging from 1 fpm to ∼1 fps with a maximum scan range of 40 × 40 µm2 has been stably and reliably realized. Dynamic morphological changes in the LiMn2O4 nanoparticles during cyclic voltammetry measurements in the 0.5 mol/l Li2SO4 solution were successfully visualized. This technique will provide the possibility of tracking dynamic processes of fast charging battery materials and other surface/interface processes such as the formation of the solid electrolyte interphase layer.

14.
Langmuir ; 36(17): 4689-4694, 2020 May 05.
Article in English | MEDLINE | ID: mdl-32279502

ABSTRACT

Exploring dynamic dimension change and lithium-ion diffusion kinetics of active nanoparticles is important to further improve the qualities of lithium-ion batteries (LIBs), such as the cycle life and charge rate. For advancing such research, an imaging technique that is capable of operating in an electrochemical environment with high spatial and temporal resolutions is really needed. In this work, we successfully developed electrochemical high-speed atomic force microscopy (EC-HS-AFM), which enabled nanoscale imaging at the rate of ∼1 frame/s during electrochemical cycling. The dimensional evolutions of LiMn2O4 single nanoparticles accompanying an insertion/extraction reaction of lithium ions were visualized. The surface area-potential hysteresis loops of the single nanoparticles at different sweep rates were quantitatively extracted from the successive HS-AFM images or video. The first-order derivative of the hysteresis loop was interestingly similar to the cyclic voltammetry (CV). Moreover, the EC-HS-AFM experiments confirmed that the utilization of the nanoparticles in the cathode can indeed improve the rate performance of the LIBs. These results demonstrated that EC-HS-AFM would be a promising tool to study dimensional evolutions and lithium-ion diffusion kinetics at a nanoscale.

15.
Sci Rep ; 8(1): 118, 2018 01 08.
Article in English | MEDLINE | ID: mdl-29311641

ABSTRACT

Inhibition and deletion of soluble epoxide hydrolase (sEH) has been suggested to ameliorate infarction in experimental ischemic stroke possibly via vasoactive epoxyeicosatrienoic acids. However, it is unknown whether the neuroprotective mechanisms involve alteration of post-ischemic neuronal transmission and neurotrophic signaling. We used a permanent middle cerebral artery occlusion (MCAO) model in adult wild-type mice with the sEH inhibitor 12-(3-adamantan-1-yl-ureido)dodecanoic acid (AUDA) post-treatment and in sEH knockout (sEH KO) mice. We found that sensorimotor recovery was significantly enhanced after MCAO in both AUDA-treated and sEH KO mice, with decreased sEH activity and brain infarction. Decreased post-ischemic long-term potentiation (iLTP) was observed in an ex vivo hippocampal oxygen-glucose deprivation model. Tropomyosin receptor kinase B (TrkB) activation, rather than glutamate receptor alteration, was consistently found after the different manipulations. Immunohistochemistry further revealed peri-infarct neuronal TrkB activation and microvasculature augmentation in AUDA-treated and sEH KO mice, suggesting parallel neurovascular enhancement. Mechanistically, pretreatment with a selective TrkB antagonist ANA12 countered the effect of iLTP attenuation induced by sEH deletion ex vivo and abolished the infarct reduction in vivo. Together, the neuroprotective effects of sEH inhibition and gene deletion can both be mediated partially via enhancement of TrkB signaling which attenuated post-ischemic neuroexcitation and neurological deficits.


Subject(s)
Epoxide Hydrolases/antagonists & inhibitors , Excitatory Postsynaptic Potentials , Membrane Glycoproteins/metabolism , Neurons/metabolism , Protein-Tyrosine Kinases/metabolism , Stroke/metabolism , Stroke/physiopathology , Animals , Cerebral Cortex/blood supply , Cerebral Cortex/metabolism , Cerebral Cortex/pathology , Disease Models, Animal , Enzyme Activation , Epoxide Hydrolases/deficiency , Gene Deletion , Hippocampus/metabolism , Male , Mice , Mice, Knockout , Motor Activity , Neuroprotective Agents , Psychomotor Performance , Stroke/etiology , Synaptic Transmission
16.
Neurophotonics ; 4(3): 035003, 2017 Jul.
Article in English | MEDLINE | ID: mdl-28983488

ABSTRACT

Current treatments for ischemic stroke have focused on the administration of a tissue plasminogen activator, although the associated side effects and subsequent reperfusion injury remain challenging. Peripheral electrical stimulation has shed light on therapeutic interventions for ischemia by increasing cerebral blood flow (CBF) to the target region through collateral circulation, although the mechanism remains elusive. Here, a focal photothrombotic ischemic (PTI) stroke was induced in the right hemispheric primary somatosensory forelimb cortex (S1FL) of rat brains, and the therapeutic effects of forelimb and hindlimb stimulation were characterized at the contralesional S1FL. We observed that PTI stroke rats that received forelimb stimulation exhibited significantly restored CBF of the ischemic penumbra ([Formula: see text] for the S1FL and [Formula: see text] for the primary somatosensory hindlimb cortex, respectively), electrocorticography (ECoG) delta band coherence of the intercortical S1FL ([Formula: see text]) at the 75th min poststroke and an ischemic infarct ([Formula: see text]) via collateral circulation recruitment. Importantly, anterior cerebral artery/middle cerebral artery (ACA-MCA) interarterial anastomotic regulation occurred upon forelimb stimulation and played roles in the recovery of neurovascular functions. These results indicated that receptive field-specific stimulation further restores CBF, neuronal activities, and tissue viability through the enhancement of ACA-MCA interarterial anastomosis-mediated collateral circulation and provides a feasible therapeutic intervention for stroke recovery.

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