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1.
Biochemistry (Mosc) ; 81(6): 591-9, 2016 Jun.
Article in English | MEDLINE | ID: mdl-27301287

ABSTRACT

Cadherin is an epidermal growth factor and laminin-G seven-pass G-type receptor 1 (CELSR1) is a key component of the noncanonical Wnt/planar cell polarity (PCP) pathway that critically regulates endothelial cell proliferation and angiogenesis. In this study, we examined the biological significance of CELSR1 in endothelial cell migration and angiogenesis. For this, we applied both gain-of-function and loss-of-function approaches. To increase the endogenous expression of CELSR1, we used the transcription activator-like effector (TALE) technology and constructed an artificial TALE-VP64 activator. To knock down the expression of CELSR1, we generated lentivirus containing short hairpin RNA sequences targeting different regions of CELSR1 mRNA. Following up- or down-regulation of CELSR1 in human aortic endothelial cells (HAEC), we assessed in vitro cell proliferation by MTT assay, migration by scratch and transwell migration assays, and angiogenesis by tube formation analysis. We found that CELSR1 was endogenously expressed in human umbilical vein endothelial cells (HUVEC) and HAEC. When focusing on HAEC, we found that upregulating CELSR1 expression significantly promoted cell growth, while knocking down CELSR1 inhibited the growth (p < 0.05). Using both scratch and transwell migration assays, we observed a positive correlation between CELSR1 expression and cell migratory capability. In addition, CELSR1 upregulation led to higher levels of tube formation in HAEC, while downregulating CELSR1 expression decreased tube formation (p < 0.05). Mechanistically, CELSR1-regulated migration and tube formation was mediated through disheveled segment polarity protein 3 (Dvl3). In conclusion, CELSR1 plays an important role in regulating multiple phenotypes of endothelial cells, including proliferation, migration, and formation of capillary-like structures.


Subject(s)
Cadherins/metabolism , Endothelial Cells/cytology , Neovascularization, Physiologic/genetics , Cadherins/antagonists & inhibitors , Cadherins/genetics , Cell Line , Cell Movement/genetics , Cell Proliferation , Endothelial Cells/metabolism , Human Umbilical Vein Endothelial Cells , Humans , Plasmids/genetics , Plasmids/metabolism , RNA Interference , RNA, Small Interfering/metabolism
2.
Ann Hum Biol ; 42(1): 26-30, 2015 Jan.
Article in English | MEDLINE | ID: mdl-25117632

ABSTRACT

BACKGROUND: Recently, CELSR1 was identified by genome-wide association studies (GWAS) as a susceptibility gene for ischaemic stroke (IS) in Japanese individuals. AIM: The goal was to examine whether CELSR1 variants are associated with IS in the Chinese Han population. SUBJECTS AND METHODS: This study genotyped two single nucleotide polymorphisms (SNPs) of CELSR1, rs6007897 and rs4044210, in a Chinese sample of 569 IS cases and 581 controls and assessed their genotype and allele associations with IS. RESULTS: The results showed that rs6007897 and rs4044210 variants of CELSR1 were significantly (p < 0.01) associated with IS. These associations remained after adjustment for age, gender, smoking status, hypertension, diabetes mellitus and hypercholesterolemia. In addition, a significant association was observed of rs6007897 and rs4044210 of CELSR1 with large artery atherosclerosis (LAA), a sub-type of IS (p < 0.01). CONCLUSION: Taken together, the present study has proven for the first time that CELSR1 is a susceptibility gene for IS in the Chinese Han population, especially for LAA.


Subject(s)
Atherosclerosis/genetics , Brain Ischemia/genetics , Cadherins/genetics , Stroke/genetics , Aged , Case-Control Studies , China , Ethnicity/genetics , Female , Genetic Predisposition to Disease , Humans , Male , Middle Aged , Polymorphism, Single Nucleotide
3.
Complement Ther Clin Pract ; 57: 101885, 2024 Jul 22.
Article in English | MEDLINE | ID: mdl-39098085

ABSTRACT

BACKGROUND AND PURPOSE: Previous studies have suggested that music listening has the potential to positively affect cognitive functions and mood in individuals with post-stroke cognitive impairment (PSCI), with a preference for self-selected music likely to yield better outcomes. However, there is insufficient clinical evidence to suggest the use of music listening in routine rehabilitation care to treat PSCI. This randomized control trial (RCT) aims to investigate the effects of personalized music listening on mood improvement, activities of daily living (ADLs), and cognitive functions in individuals with PSCI. MATERIALS AND METHODS: A total of 34 patients with PSCI were randomly assigned to either the music group or the control group. Patients in the music group underwent a three-month personalized music-listening intervention. The intervention involved listening to a personalized playlist tailored to each individual's cultural, ethnic, and social background, life experiences, and personal music preferences. In contrast, the control group patients listened to white noise as a placebo. Cognitive function, neurological function, mood, and ADLs were assessed. RESULTS: After three months of treatment, the music group showed significantly higher Montreal Cognitive Assessment (MoCA) scores compared to the control group (p=0.027), particularly in the domains of delayed recall (p=0.019) and orientation (p=0.023). Moreover, the music group demonstrated significantly better scores in National Institutes of Health Stroke Scale (NIHSS) (p=0.008), Barthel Index (BI) (p=0.019), and Zarit Caregiver Burden Interview (ZBI) (p=0.008) compared to the control group. No effects were found on mood as measured by the Hamilton Anxiety Rating Scale (HAMA) and the Hamilton Depression Rating Scale (HAMD). CONCLUSION: Personalized music listening promotes the recovery of cognitive and neurological functions, improves ADLs, and reduces caregiver burden in patients with PSCI.

4.
Front Neurosci ; 18: 1368552, 2024.
Article in English | MEDLINE | ID: mdl-38716255

ABSTRACT

Probucol has been utilized as a cholesterol-lowering drug with antioxidative properties. However, the impact and fundamental mechanisms of probucol in obesity-related cognitive decline are unclear. In this study, male C57BL/6J mice were allocated to a normal chow diet (NCD) group or a high-fat diet (HFD) group, followed by administration of probucol to half of the mice on the HFD regimen. Subsequently, the mice were subjected to a series of behavioral assessments, alongside the measurement of metabolic and redox parameters. Notably, probucol treatment effectively alleviates cognitive and social impairments induced by HFD in mice, while exhibiting no discernible influence on mood-related behaviors. Notably, the beneficial effects of probucol arise independently of rectifying obesity or restoring systemic glucose and lipid homeostasis, as evidenced by the lack of changes in body weight, serum cholesterol levels, blood glucose, hyperinsulinemia, systemic insulin resistance, and oxidative stress. Instead, probucol could regulate the levels of nitric oxide and superoxide-generating proteins, and it could specifically alleviate HFD-induced hippocampal insulin resistance. These findings shed light on the potential role of probucol in modulating obesity-related cognitive decline and urge reevaluation of the underlying mechanisms by which probucol exerts its beneficial effects.

5.
Liver Int ; 33(1): 137-48, 2013 Jan.
Article in English | MEDLINE | ID: mdl-23121546

ABSTRACT

BACKGROUND: Cyclin kinase subunit-2 (Cks2), a member of the human Cks family, plays an important role in the regulation of meiosis and mitosis; and its abnormal expression is usually associated with carcinogenesis. However, its exact functions and molecular mechanisms remain unclear. AIMS: To observe Cks2 expression in cholangiocarcinoma and explore its role in the carcinogenesis of cholangiocarcinoma and possible mechanism. METHODS: Cks2 expression in cholangiocarcinoma was detected with immunostaining and RT-PCR. MTT, colony formation, immunofluorescence, flow cytometry and Western blotting were performed to explore the role of Cks2 in cholangiocarcinoma and possible mechanism. RESULTS: Cks2 was significantly elevated in cholangiocarcinoma tissues and its over-expression was associated with poor differentiation, CA19-9 and poor prognosis. Furthermore, Cks2 down-regulation inhibited cholangiocarcinoma cell proliferation and colony formation in vitro, and the growth of cholangiocarcinoma xenografts in animals; especially, enhanced the sensitivity of cholangiocarcinoma cells to chemotherapy. We further found that Cks2 knockdown induced cholangiocarcinoma cell cycle arrest in G2/M phase through down-regulation of Cyclin A and Cyclin B1 and Bax up-regulation and activation, mitochondrial membrane permeabilization and caspase-3 activation, which resulted in facilitating cholangiocarcinoma apoptosis. CONCLUSIONS: These findings suggest that Cks2 may serve as an independent prognostic factor in patients with cholangiocarcinoma, and play an important role in the carcinogenesis of cholangiocarcinoma by facilitating cell cycle progression and Bax-mediated mitochondrial caspase-dependent apoptosis.


Subject(s)
Bile Duct Neoplasms/enzymology , Bile Ducts, Intrahepatic/enzymology , CDC2-CDC28 Kinases/metabolism , Carrier Proteins/metabolism , Cell Cycle Proteins/metabolism , Cholangiocarcinoma/enzymology , Animals , Antineoplastic Agents/pharmacology , Apoptosis , Bile Duct Neoplasms/blood , Bile Duct Neoplasms/genetics , Bile Duct Neoplasms/mortality , Bile Duct Neoplasms/pathology , Bile Duct Neoplasms/surgery , Bile Ducts, Intrahepatic/pathology , Blotting, Western , CA-19-9 Antigen/blood , CDC2-CDC28 Kinases/genetics , Carrier Proteins/genetics , Caspase 3/metabolism , Cell Cycle Proteins/genetics , Cell Differentiation , Cell Line, Tumor , Cell Proliferation , Cholangiocarcinoma/blood , Cholangiocarcinoma/genetics , Cholangiocarcinoma/mortality , Cholangiocarcinoma/pathology , Cholangiocarcinoma/surgery , Cyclin A/metabolism , Cyclin B1/metabolism , Drug Resistance, Neoplasm , Female , Flow Cytometry , Fluorescent Antibody Technique , G2 Phase Cell Cycle Checkpoints , Humans , Immunohistochemistry , Kaplan-Meier Estimate , Male , Mice , Mice, Inbred BALB C , Mice, Nude , Middle Aged , Polymerase Chain Reaction , Prognosis , RNA Interference , RNA, Messenger/analysis , Time Factors , Transfection , Tumor Burden , Up-Regulation , bcl-2-Associated X Protein/metabolism
6.
Behav Sci (Basel) ; 13(4)2023 Apr 07.
Article in English | MEDLINE | ID: mdl-37102832

ABSTRACT

The digital transformation and innovative development of museums have led consumers to increasingly prefer purchasing museum cultural and creative products through e-commerce platforms. Although this trend shows potential for market growth, the lack of distinct cultural identity and insufficient product differentiation hinder its stable development. Therefore, this study aims to explore consumers' perceptions on Palace Museum's cultural and creative products using cultural hierarchy theory. Taking the Palace Museum's Cultural and Creative Flagship Store on Tmall.com as a case study, the employed evaluation method involves constructing a lexicon of cultural features using Word2vec model and then analyzing online textual reviews to identify these features. Results reveal that among the various cultural features of the products, consumers placed the greatest emphasis on "Materials used" and the least on "Specialty craft". With regards to the cultural features of inner "intangible" level, consumers tend to have a limited comprehension and familiarity with the cultural heritage and histories behind the products. This study provides suggestions to museum professionals to optimize the use of traditional cultural resources and develop a product development plan.

7.
Anal Chem ; 84(19): 8102-5, 2012 Oct 02.
Article in English | MEDLINE | ID: mdl-22974138

ABSTRACT

Extraction of intracellular proteins from cells is often an important first step for conducting molecular biology and proteomics studies. Although ultrasensitive detection and analytical technology at the single molecule level is becoming routine, protein extraction techniques have not followed suit and still call for complete lysis that leads to cell death. In principle, with refined extraction techniques, intracellular proteins can potentially be extracted without killing the cell. In this Letter, we demonstrate that electroporation is capable of releasing intracellular proteins from adherent Chinese hamster ovary cells while preserving the cell viability. By tuning the duration and intensity of an electric pulse, we were able to control the average amount of protein release and the percentage of viable cells after the operation. Our results indicate that a substantial fraction of the cell population was able to release proteins under electroporation and survive the procedure. Interestingly, at the single cell level, the probability for cell death does not increase with more protein release. This work paves the way to extracting and analyzing intracellular proteins while keeping cells live.


Subject(s)
Electroporation , Proteins/metabolism , Animals , CHO Cells , Cell Survival , Cricetinae
8.
Sci China Life Sci ; 65(10): 1971-1984, 2022 10.
Article in English | MEDLINE | ID: mdl-35508791

ABSTRACT

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is characterized by a strong production of inflammatory cytokines such as TNF and IL-6, which underlie the severity of the disease. However, the molecular mechanisms responsible for such a strong immune response remains unclear. Here, utilizing targeted tandem mass spectrometry to analyze serum metabolome and lipidome in COVID-19 patients at different temporal stages, we identified that 611 metabolites (of 1,039) were significantly altered in COVID-19 patients. Among them, two metabolites, agmatine and putrescine, were prominently elevated in the serum of patients; and 2-quinolinecarboxylate was changed in a biphasic manner, elevated during early COVID-19 infection but levelled off. When tested in mouse embryonic fibroblasts (MEFs) and macrophages, these 3 metabolites were found to activate the NF-κB pathway that plays a pivotal role in governing cytokine production. Importantly, these metabolites were each able to cause strong increase of TNF and IL-6 levels when administered to wildtype mice, but not in the mice lacking NF-κB. Intriguingly, these metabolites have little effects on the activation of interferon regulatory factors (IRFs) for the production of type I interferons (IFNs) for antiviral defenses. These data suggest that circulating metabolites resulting from COVID-19 infection may act as effectors to elicit the peculiar systemic inflammatory responses, exhibiting severely strong proinflammatory cytokine production with limited induction of the interferons. Our study may provide a rationale for development of drugs to alleviate inflammation in COVID-19 patients.


Subject(s)
Agmatine , COVID-19 , Interferon Type I , Animals , Antiviral Agents/therapeutic use , Cytokines/metabolism , Fibroblasts/metabolism , Interferon Regulatory Factors/metabolism , Interferon Type I/metabolism , Interleukin-6/metabolism , Mice , NF-kappa B/metabolism , Putrescine , SARS-CoV-2
9.
Anal Chem ; 83(22): 8816-20, 2011 Nov 15.
Article in English | MEDLINE | ID: mdl-21967571

ABSTRACT

The manipulation of cells inside water-in-oil droplets is essential for high-throughput screening of cell-based assays using droplet microfluidics. Cell transfection inside droplets is a critical step involved in functional genomics studies that examine in situ functions of genes using the droplet platform. Conventional water-in-hydrocarbon oil droplets are not compatible with chemical transfection due to its damage to cell viability and extraction of organic transfection reagents from the aqueous phase. In this work, we studied chemical transfection of cells encapsulated in picoliter droplets in fluorocarbon oil. The use of fluorocarbon oil permitted high cell viability and little loss of the transfection reagent into the oil phase. We varied the incubation time inside droplets, the DNA concentration, and the droplet size. After optimization, we were able to achieve similar transfection efficiency in droplets to that in the bulk solution. Interestingly, the transfection efficiency increased with smaller droplets, suggesting effects from either the microscale confinement or the surface-to-volume ratio.


Subject(s)
Fluorocarbons/chemistry , Oils/chemistry , Transfection , Animals , CHO Cells , Cell Survival , Cells, Cultured , Cricetinae , DNA/analysis , Microfluidics , Water/chemistry
10.
Nat Cell Biol ; 23(3): 268-277, 2021 03.
Article in English | MEDLINE | ID: mdl-33664495

ABSTRACT

The sympathetic nervous system-catecholamine-uncoupling protein 1 (UCP1) axis plays an essential role in non-shivering adaptive thermogenesis. However, whether there exists a direct effector that physically connects catecholamine signalling to UCP1 in response to acute cold is unknown. Here we report that outer mitochondrial membrane-located AIDA is phosphorylated at S161 by the catecholamine-activated protein kinase A (PKA). Phosphorylated AIDA translocates to the intermembrane space, where it binds to and activates the uncoupling activity of UCP1 by promoting cysteine oxidation of UCP1. Adipocyte-specific depletion of AIDA abrogates UCP1-dependent thermogenesis, resulting in hypothermia during acute cold exposure. Re-expression of S161A-AIDA, unlike wild-type AIDA, fails to restore the acute cold response in Aida-knockout mice. The PKA-AIDA-UCP1 axis is highly conserved in mammals, including hibernators. Denervation of the sympathetic postganglionic fibres abolishes cold-induced AIDA-dependent thermogenesis. These findings uncover a direct mechanistic link between sympathetic input and UCP1-mediated adaptive thermogenesis.


Subject(s)
Adipocytes, Brown/metabolism , Adipose Tissue, Brown/innervation , Phospholipid Transfer Proteins/metabolism , Sympathetic Nervous System/physiology , Thermogenesis , Uncoupling Protein 1/metabolism , Adiponectin/genetics , Adiponectin/metabolism , Animals , Cells, Cultured , Cyclic AMP-Dependent Protein Kinases/metabolism , Energy Metabolism , Male , Mice, Inbred C57BL , Mice, Knockout , Oxidation-Reduction , Phospholipid Transfer Proteins/deficiency , Phospholipid Transfer Proteins/genetics , Phosphorylation , Signal Transduction , Uncoupling Protein 1/deficiency , Uncoupling Protein 1/genetics
11.
Lab Chip ; 10(16): 2046-8, 2010 Aug 21.
Article in English | MEDLINE | ID: mdl-20548993

ABSTRACT

Conventional biochemical analysis mainly focuses on the expression level of cellular proteins from entire cells. However, it has been increasingly acknowledged that the subcellular location of proteins often carries important information. Analysis of subcellular proteins conventionally requires subcellular fractionation which involves two steps: cell lysis to release proteins and high-speed centrifugation to separate the homogenate. Such approach requires bulky and expensive equipment and is not compatible with processing scarce cell samples of limited volume. In this study, we apply microfluidic flow-through electroporation to breach cell membranes and extract cytosolic proteins selectively in a single step. We demonstrate that this approach allows monitoring the translocation of the transcription factor NF-kappaB from the cytosol to the nucleus without the need of subcellular fractionation. Our technique is compatible with the processing of samples of various sizes and provides a simple and universal tool for bioanalytical analysis and spatial proteomics.


Subject(s)
Electroporation/methods , Eukaryotic Cells/chemistry , Proteins/isolation & purification , Animals , CHO Cells , Cell Membrane , Cricetinae , Cricetulus , NF-kappa B/isolation & purification , Subcellular Fractions/chemistry
12.
Lab Chip ; 10(16): 2057-61, 2010 Aug 21.
Article in English | MEDLINE | ID: mdl-20563345

ABSTRACT

Electroporation is one of the most widely used methods to deliver exogenous DNA payloads into cells, but a major limitation is that only a small fraction of the total membrane surface is permeabilized. Here we show how this barrier can be easily overcome by harnessing hydrodynamic effects associated with Dean flows that occur along curved paths. Under these conditions, cells are subjected to a combination of transverse vortex motion and rotation that enables the entire membrane surface to become uniformly permeabilized. Greatly improved transfection efficiencies are achievable with only a simple modification to the design of existing continuous flow electroporation systems.


Subject(s)
DNA/administration & dosage , DNA/chemistry , Drug Delivery Systems/methods , Electroporation/methods , Animals , CHO Cells , Cell Membrane/chemistry , Cell Membrane Permeability , Cricetinae , Cricetulus , DNA/genetics , Electroporation/instrumentation , Lab-On-A-Chip Devices , Microscopy, Confocal
13.
Lab Chip ; 10(21): 2911-6, 2010 Nov 07.
Article in English | MEDLINE | ID: mdl-20835431

ABSTRACT

Transport of protein and RNA cargoes between the nucleus and cytoplasm (nucleocytoplasmic transport) is vital for a variety of cellular functions. The studies of kinetics involved in such processes have been hindered by the lack of quantitative tools for measurement of the nuclear and cytosolic fractions of an intracellular protein at the single cell level for a cell population. In this report, we describe using a novel method, microfluidic electroporative flow cytometry, to study kinetics of nucleocytoplasmic transport of an important transcription factor NF-κB. With data collected from single cells, we quantitatively characterize the population-averaged kinetic parameters such as the rate constants and apparent activation barrier for NF-κB transport. Our data demonstrate that NF-κB nucleocytoplasmic transport fits first-order kinetics very well and is a fairly reversible process governed by equilibrium thermodynamics.


Subject(s)
Cell Nucleus/metabolism , Cytoplasm/metabolism , NF-kappa B/metabolism , Animals , CHO Cells , Cricetinae , Cricetulus , Flow Cytometry , Kinetics , Microfluidics , Microscopy, Fluorescence
14.
Front Neurol ; 11: 399, 2020.
Article in English | MEDLINE | ID: mdl-32536902

ABSTRACT

To determine the cortical mechanism that underlies the cognitive impairment and motor disability in hereditary spastic paraplegia (HSP), nine HSP patients from a Chinese family were examined using clinical evaluation, cognitive screening, and genetic testing. Controls were matched healthy subjects. White-matter fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD; tract-based spatial statistics), cortical thickness (FreeSurfer), and subcortical gray matter (FIRST) based on T1-weighted MRI and diffusion tensor imaging were analyzed. A novel mutation in the SPAST gene (NM_014946.3, c.1321+2T>C) was detected. Patients had motor disability and low Montreal Cognitive Assessment (MoCA) scores. Patients showed significantly decreased total gray- and white-matter volumes, corpus callosum volume, cortical thickness, and subcortical gray-matter volume as well as significantly lower FA and AD values and significantly higher MD and RD values in the corpus callosum and corticospinal tract. Cortical thickness, subcortical gray-matter volume, and MoCA score were negatively correlated with disease duration. Cortical thickness in the right inferior frontal cortex was negatively correlated with Spastic Paraplegia Rating Scale score. Cortical thickness and right hippocampus volume were positively correlated with the MoCA score and subscores. In conclusion, brain damage is not restricted to the white matter in SPG4-HSP patients, and widespread gray-matter damage may account for the disease progression, cognitive impairment, and disease severity in SPG4-HSP.

15.
Oncogene ; 39(13): 2707-2723, 2020 03.
Article in English | MEDLINE | ID: mdl-32005973

ABSTRACT

Mitochondrial fusion and fission dynamics fine-tune cellular calcium homeostasis, ATP production capacity and ROS production and play important roles in cell proliferation and migration. Dysregulated mitochondrial dynamics is closely related to tumor development, but the mechanism of mitochondrial dynamics dysregulation and its role in the development of lung cancer remains unclear. Here, we demonstrate that the DNA sensor protein absent in melanoma 2 (AIM2) is highly expressed in non-small cell lung cancer (NSCLC) cells and that high AIM2 expression is associated with poor prognosis in patients with NSCLC. High expression of AIM2 contributes to tumor cell growth and proliferation independent of inflammasome activation in vitro and in vivo. Further studies have shown that AIM2 colocalizes with mitochondria in NSCLC cells and that AIM2 knockdown leads to enhanced mitochondrial fusion and decreased cell proliferation. Mechanistic studies have shown that AIM2 downregulation promotes MFN2 upregulation, thereby enhancing mitochondrial fusion. Moreover, we found that mitochondrial fusion driven by AIM2 knockdown leads to a decrease of cellular reactive oxygen species (ROS) production, which further causes inactivation of the MAPK/ERK signaling pathway. Together, we discovered a novel function of AIM2 in promoting NSCLC development by regulating mitochondrial dynamics and revealed its underlying mechanism. Our work provides new intervention targets for the treatment of NSCLC.


Subject(s)
Carcinoma, Non-Small-Cell Lung/genetics , DNA-Binding Proteins/metabolism , Lung Neoplasms/genetics , Mitochondria/pathology , Mitochondrial Dynamics/genetics , Animals , Carcinoma, Non-Small-Cell Lung/mortality , Carcinoma, Non-Small-Cell Lung/pathology , Cell Line, Tumor , Cell Proliferation , DNA-Binding Proteins/genetics , Datasets as Topic , Female , GTP Phosphohydrolases/metabolism , Gene Expression Regulation, Neoplastic , Gene Knockdown Techniques , Humans , Kaplan-Meier Estimate , Lung Neoplasms/mortality , Lung Neoplasms/pathology , MAP Kinase Signaling System/genetics , Mice , Mitochondria/metabolism , Mitochondrial Proteins/metabolism , Prognosis , RNA, Small Interfering/metabolism , Reactive Oxygen Species/metabolism , Up-Regulation , Xenograft Model Antitumor Assays
16.
Anal Chem ; 81(5): 2027-31, 2009 Mar 01.
Article in English | MEDLINE | ID: mdl-19199389

ABSTRACT

Droplet-based microfluidics has raised a lot of interest recently due to its wide applications to screening biological/chemical assays with high throughput. Despite the advances on droplet-based assays involving cells, gene delivery methods that are compatible with the droplet platform have been lacking. In this report, we demonstrate a simple microfluidic device that encapsulates cells into aqueous droplets and then electroporates the encapsulated cells. The electroporation occurs when the cell-containing droplets (in oil) flow through a pair of microelectrodes with a constant voltage established in between. We investigate the parameters and characteristics of the electroporation. We demonstrate delivering enhanced green fluorescent protein (EGFP) plasmid into Chinese hamster ovary (CHO) cells. We envision the application of this technique to high-throughput functional genomics studies based on droplet microfluidics.


Subject(s)
Electroporation/methods , Microfluidics/methods , Animals , CHO Cells , Cell Separation/methods , Cell Survival/physiology , Cricetinae , Cricetulus , Electrochemistry , Female , Green Fluorescent Proteins/genetics , Green Fluorescent Proteins/physiology , Microfluidic Analytical Techniques/instrumentation
17.
Nanomedicine ; 5(2): 192-201, 2009 Jun.
Article in English | MEDLINE | ID: mdl-19223244

ABSTRACT

Fast cytoplasmic drug delivery can overcome cancer cells' drug resistance and thus have an enhanced therapeutic efficacy. Such a drug delivery regime requires drug carriers capable of entering cancer cells, localizing and rapidly releasing the drug into endosomes/lysosomes, and subsequently disrupting their membranes to release the drug into the cytosol. We herein report a low-toxic and degradable poly(beta-amino ester)-graft-polyethylene glycol (BAE-PEG) co-polymer forming pH-responsive nanoparticles capable of cytoplasmic drug delivery. BAE-PEG was synthesized by condensation polymerization of diacrylate and piperazine in the presence of a PEG-diacrylate macromonomer. BAE-PEG with 2% or 5% PEG side chains formed micelles (nanoparticles) with diameters of about 100 nm. The BAE-PEG nanoparticles were shown to rapidly enter cancer cells, localize in their endosomes/lysosomes, and subsequently disrupt them to release the drugs into the cytosol. Camptothecin loaded in the nanoparticles had a higher cytotoxicity to SKOV-3 ovarian cancer cells than free camptothecin.


Subject(s)
Antineoplastic Agents/administration & dosage , Drug Carriers/chemistry , Nanoparticles/chemistry , Piperazines/chemistry , Polyethylene Glycols/chemistry , Animals , Camptothecin/administration & dosage , Camptothecin/chemistry , Cell Line, Tumor , Cytosol/drug effects , Drug Carriers/metabolism , Endosomes/metabolism , Humans , Hydrogen-Ion Concentration , Microscopy, Confocal , Nanoparticles/toxicity , Piperazines/metabolism , Piperazines/toxicity , Polyethylene Glycols/metabolism , Polyethylene Glycols/toxicity , Polymers/chemistry , Polymers/metabolism , Polymers/toxicity , Sheep
18.
Cell Biosci ; 9: 60, 2019.
Article in English | MEDLINE | ID: mdl-31367332

ABSTRACT

BACKGROUND: Mutated epidermal growth factor receptor (EGFR) is one of the most successful targets in cancer targeted therapy. While this treatment has benefited many patients with an activating EGFR mutation (EGFRm), almost all those who initially benefited will eventually develop acquired drug resistance (ADR) after a certain period of time. New therapeutic strategies need to be explored to treat EGFRm tumors and overcome or minimize this recurring ADR. RESULTS: Our data showed that apigenin alone has only mild inhibitory effects on EGFRm tumor cells. By drug screening, we found that ABT-263 can significantly enhance the antitumor activities of apigenin in tumor cells harbouring an activating EGFR mutation and AZD9291-resistant H1975 cells. Mechanistically, apigenin upregulated the expression of Noxa in EGFRm tumor cells by targeting the AKT-FoxO3a pathway, thereby synergizing with ABT-263 to suppress tumor cell growth and proliferation in vitro and in vivo. CONCLUSIONS: Our study provides a rationale for the clinical application of the combination treatment of apigenin and BH3 mimetics in the treatment of EGFRm tumors.

19.
Anal Chem ; 80(20): 7714-9, 2008 Oct 15.
Article in English | MEDLINE | ID: mdl-18798650

ABSTRACT

Biomechanical properties of cells yield important information on the disease state of cells such as transformation and metastasis. Screening of cells based on their biomechanical properties provides rapid tools for label-free diagnosis and staging of cancers. However, existent single-cell techniques for measuring biomechanical properties suffer from low throughput (<1 cell/min). This prevents the application of these assays to a large cell population, which produces information with statistical significance. In this study, we applied microfluidics-based electroporative flow cytometry (EFC) that combined electroporation with flow cytometry to study deformability of cells at the single-cell level with a throughput of approximately 5 cells/s. The cell swelling during flow-through electroporation was recorded in real time. We believe that the degree of such swelling was indicative of the cell deformability and the cytoskeleton mechanics. Three cell types (MCF-10A, MCF-7, and 12- O-tetradecanoylphorbol-13-acetate-treated MCF-7) with different malignancy and metastatic potential were tested using our approach. We found that the more malignant and metastatic cell types exhibited more swelling due to higher cell deformability. Furthermore, the disruption of microtubules by colchicine caused substantial change in the EFC results, which confirmed that EFC data strongly reflected the cytoskeletal mechanics. Finally, the cell type with the highest metastatic potential also suffered the most cell death due to the flow-through electroporation treatment, presumably due to the most substantial cell swelling, which could irreversibly rupture the membrane. EFC provides a new method for examining single-cell biomechanics with high throughput. We believe that this technique will be useful for mechanistic studies of cytoskeleton dynamics and clinical applications such as diagnosis and staging of cancers in general.


Subject(s)
Cells/cytology , Electroporation/methods , Flow Cytometry/methods , Microfluidic Analytical Techniques/methods , Biomechanical Phenomena , Cell Line, Tumor , Cell Size , Cell Survival , Cytoskeleton , Humans
20.
Biochem Pharmacol ; 150: 72-85, 2018 04.
Article in English | MEDLINE | ID: mdl-29360439

ABSTRACT

Non-small cell lung cancer (NSCLC) is the most common malignancy worldwide. A significant fraction of NSCLC carries activating mutations in epidermal growth factor receptor (EGFR) or RAS oncogene. Dihydroartemisinin (DHA) is a semisynthetic derivative of the herbal antimalarial drug artemisinin that has been recently reported to exhibit anti-cancer activity. To develop new therapeutic strategies for NSCLC, we investigated the interactions between DHA and ABT-263 in NSCLC cells harboring EGFR or RAS mutation. Our data indicated that DHA synergized with ABT-263 to trigger Bax-dependent apoptosis in NSCLC cells in culture. DHA treatment antagonized ABT-263-induced Mcl-1 upregulation and sensitized NSCLC cells to ABT-263-triggered apoptosis. Additionally, DHA treatment caused downregulation of Survivin and upregulation of Bim, which also contribute to cotreatment-induced cytotoxicity. Moreover, DHA effectively suppressed STAT3 phosphorylation, and STAT3 inactivation resulted in the downregulation of Mcl-1 and Survivin, functioning to enhance ABT-263-induced cytotoxicity. Finally, cotreatment of DHA and ABT-263 significantly inhibited xenograft growth in nude mice. Together, DHA effectively inhibits STAT3 activity and modulates expression of Mcl-1, Survivin and Bim, thereby synergizing with ABT-263 to trigger apoptosis in NSCLC cells harboring EGFR or RAS mutation. Our data provide a novel therapeutic strategy for EGFR or RAS mutant NSCLC treatment.


Subject(s)
Aniline Compounds/administration & dosage , Artemisinins/administration & dosage , Carcinoma, Non-Small-Cell Lung/metabolism , Lung Neoplasms/metabolism , Myeloid Cell Leukemia Sequence 1 Protein/biosynthesis , STAT3 Transcription Factor/metabolism , Sulfonamides/administration & dosage , Survivin/biosynthesis , A549 Cells , Animals , Antineoplastic Agents/administration & dosage , Apoptosis/drug effects , Apoptosis/physiology , Carcinoma, Non-Small-Cell Lung/genetics , Dose-Response Relationship, Drug , Drug Synergism , ErbB Receptors/genetics , Female , Gene Expression Regulation, Enzymologic , Genes, ras/genetics , Humans , Lung Neoplasms/genetics , Mice , Mice, Inbred BALB C , Mice, Nude , Mutation/physiology , Myeloid Cell Leukemia Sequence 1 Protein/antagonists & inhibitors , Myeloid Cell Leukemia Sequence 1 Protein/genetics , STAT3 Transcription Factor/antagonists & inhibitors , Survivin/antagonists & inhibitors , Survivin/genetics , Xenograft Model Antitumor Assays/methods
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