scholarly journals Dielectrophoresis as a Tool to Reveal the Potential Role of Ion Channels and Early Electrophysiological Changes in Osteoarthritis

Micromachines ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 949
Author(s):  
Rula Abdallat ◽  
Emily Kruchek ◽  
Csaba Matta ◽  
Rebecca Lewis ◽  
Fatima H. Labeed
Keyword(s):  
Rapid Assessment ◽  
Disease Model ◽  
Membrane Conductance ◽  
Label Free ◽  
Dielectric Parameters ◽  
Whole Cell ◽  
Membrane Conductivity ◽  
Cell Capacitance

Diseases such as osteoarthritis (OA) are commonly characterized at the molecular scale by gene expression and subsequent protein production; likewise, the effects of pharmaceutical interventions are typically characterized by the effects of molecular interactions. However, these phenomena are usually preceded by numerous precursor steps, many of which involve significant ion influx or efflux. As a consequence, rapid assessment of cell electrophysiology could play a significant role in unravelling the mechanisms underlying drug interactions and progression of diseases, such as OA. In this study, we used dielectrophoresis (DEP), a technique that allows rapid, label-free determination of the dielectric parameters to assess the role of potassium ions on the dielectric characteristics of chondrocytes, and to investigate the electrophysiological differences between healthy chondrocytes and those from an in vitro arthritic disease model. Our results showed that DEP was able to detect a significant decrease in membrane conductance (6191 ± 738 vs. 8571 ± 1010 S/m2), membrane capacitance (10.3 ± 1.47 vs. 14.5 ± 0.01 mF/m2), and whole cell capacitance (5.4 ± 0.7 vs. 7.5 ± 0.3 pF) following inhibition of potassium channels using 10 mM tetraethyl ammonium, compared to untreated healthy chondrocytes. Moreover, cells from the OA model had a different response to DEP force in comparison to healthy cells; this was seen in terms of both a decreased membrane conductivity (782 S/m2 vs. 1139 S/m2) and a higher whole cell capacitance (9.58 ± 3.4 vs. 3.7 ± 1.3 pF). The results show that DEP offers a high throughput method, capable of detecting changes in membrane electrophysiological properties and differences between disease states.

scholarly journals Dual Role of Interleukin-10 in Murine NZB/W F1 Lupus

2021 ◽  
Vol 22 (3) ◽  
pp. 1347
Author(s):  
Anaïs Amend ◽  
Natalie Wickli ◽  
Anna-Lena Schäfer ◽  
Dalina T. L. Sprenger ◽  
Rudolf A. Manz ◽  
...  
Keyword(s):  
B Cell ◽  
Disease Model ◽  
Interleukin 10 ◽  
Immune Functions ◽  
Murine Lupus ◽  
Anti Inflammatory ◽  
In Vivo Effects

As a key anti-inflammatory cytokine, IL-10 is crucial in preventing inflammatory and autoimmune diseases. However, in human and murine lupus, its role remains controversial. Our aim was to understand regulation and immunologic effects of IL-10 on different immune functions in the setting of lupus. This was explored in lupus-prone NZB/W F1 mice in vitro and vivo to understand IL-10 effects on individual immune cells as well as in the complex in vivo setting. We found pleiotropic IL-10 expression that largely increased with progressing lupus, while IL-10 receptor (IL-10R) levels remained relatively stable. In vitro experiments revealed pro- and anti-inflammatory IL-10 effects. Particularly, IL-10 decreased pro-inflammatory cytokines and slowed B cell proliferation, thereby triggering plasma cell differentiation. The frequent co-expression of ICOS, IL-21 and cMAF suggests that IL-10-producing CD4 T cells are important B cell helpers in this context. In vitro and in vivo effects of IL-10 were not fully concordant. In vivo IL-10R blockade slightly accelerated clinical lupus manifestations and immune dysregulation. Altogether, our side-by-side in vitro and in vivo comparison of the influence of IL-10 on different aspects of immunity shows that IL-10 has dual effects. Our results further reveal that the overall outcome may depend on the interplay of different factors such as target cell, inflammatory and stimulatory microenvironment, disease model and state. A comprehensive understanding of such influences is important to exploit IL-10 as a therapeutic target.

Quantitative proteomics identifies FOLR1 to drive sorafenib resistance via activating autophagy in hepatocellular carcinoma cells

2021 ◽  
Author(s):  
Hongwei Chu ◽  
Changqing Wu ◽  
Qun Zhao ◽  
Rui Sun ◽  
Kuo Yang ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Folate Receptor ◽  
Mass Spectrometry Analysis ◽  
Label Free ◽  
Spectrometry Analysis ◽  
Underlying Mechanisms ◽  
Related Proteins ◽  
Hcc Cells

Abstract Sorafenib is commonly used to treat advanced human hepatocellular carcinoma (HCC). However, clinical efficacy has been limited by drug resistance. In this study, we used label-free quantitative proteomic analysis to systematically investigate the underlying mechanisms of sorafenib resistance in HCC cells. A total of 1709 proteins were confidently quantified. Among them, 89 were differentially expressed, and highly enriched in the processes of cell-cell adhesion, negative regulation of apoptosis, response to drug and metabolic processes involving in sorafenib resistance. Notably, folate receptor α (FOLR1) was found to be significantly upregulated in resistant HCC cells. In addition, in-vitro studies showed that overexpression of FOLR1 decreased the sensitivity of HCC cells to sorafenib, whereas siRNA-directed knockdown of FOLR1 increased the sensitivity of HCC cells to sorafenib. Immunoprecipitation-mass spectrometry analysis suggested a strong link between FOLR1 and autophagy related proteins. Further biological experiments found that FOLR1-related sorafenib resistance was accompanied by the activation of autophagy, whereas inhibition of autophagy significantly reduced FOLR1-induced cell resistance. These results suggest the driving role of FOLR1 in HCC resistance to sorafenib, which may be exerted through FOLR1-induced autophagy. Therefore, this study may provide new insights into understanding the mechanism of sorafenib resistance.

scholarly journals The Ser/Thr kinase p90RSK promotes kidney fibrosis by modulating fibroblast–epithelial crosstalk

2019 ◽  
Vol 294 (25) ◽  
pp. 9901-9910 ◽  
Author(s):  
Ling Lin ◽  
Chaowen Shi ◽  
Zhaorui Sun ◽  
Nhat-Tu Le ◽  
Jun-Ichi Abe ◽  
...  
Keyword(s):  
Chronic Kidney Disease ◽  
Kidney Disease ◽  
Nuclear Translocation ◽  
Disease Model ◽  
Kidney Fibrosis ◽  
Cellular Processes ◽  
Ribosomal Protein S6 ◽  
Forkhead Box

Healthy kidney structure and environment rely on epithelial integrity and interactions between epithelial cells and other kidney cells. The Ser/Thr kinase 90 kDa ribosomal protein S6 kinase 1 (p90RSK) belongs to a protein family that regulates many cellular processes, including cell motility and survival. p90RSK is predominantly expressed in the kidney, but its possible role in chronic kidney disease (CKD) remains largely unknown. Here, we found that p90RSK expression is dramatically activated in a classic mouse obstructive chronic kidney disease model, largely in the interstitial FSP-1–positive fibroblasts. We generated FSP-1–specific p90RSK transgenic mouse (RSK-Tg) and discovered that these mice, after obstructive injury, display significantly increased fibrosis and enhanced tubular epithelial damage compared with their wt littermates (RSK-wt), indicating a role of p90RSK in fibroblast–epithelial communication. We established an in vitro fibroblast–epithelial coculture system with primary kidney fibroblasts from RSK-Tg and RSK-wt mice and found that RSK-Tg fibroblasts consistently produce excessive H2O2 causing epithelial oxidative stress and inducing nuclear translocation of the signaling protein β-catenin. Epithelial accumulation of β-catenin, in turn, promoted epithelial apoptosis by activating the transcription factor forkhead box class O1 (FOXO1). Of note, blockade of reactive oxygen species (ROS) or β-catenin or FOXO1 activity abolished fibroblast p90RSK-mediated epithelial apoptosis. These results make it clear that p90RSK promotes kidney fibrosis by inducing fibroblast-mediated epithelial apoptosis through ROS-mediated activation of β-catenin/FOXO1 signaling pathway.

scholarly journals Electropermeabilization and fluorescent tracer exchange: The role of whole-cell capacitance

Cytometry ◽  
1995 ◽  
Vol 21 (3) ◽  
pp. 230-240 ◽  
Author(s):  
Vladimir L. Sukhorukov ◽  
Cholpon S. Djuzenova ◽  
Hermann Frank ◽  
W. Michael Arnold ◽  
Ulrich Zimmermann
Keyword(s):  
Fluorescent Tracer ◽  
Whole Cell ◽  
Cell Capacitance ◽  
Tracer Exchange

scholarly journals A whole-cell recording database of neuromodulatory action in the adult neocortex

2022 ◽  
Author(s):  
Xuan Yan ◽  
Niccolo Calcini ◽  
Payam Safavi ◽  
Asli Ak ◽  
Koen Kole ◽  
...  
Keyword(s):  
Information Processing ◽  
Biological Networks ◽  
Neural Coding ◽  
Inhibitory Neurons ◽  
Systematic Analysis ◽  
Whole Cell ◽  
Adult Mice ◽  
Insight Into

Background: The recent release of two large intracellular electrophysiological databases now allows high-dimensional systematic analysis of mechanisms of information processing in the neocortex. Here, to complement these efforts, we introduce a freely and publicly available database that provides a comparative insight into the role of various neuromodulatory transmitters in controlling neural information processing. Findings: A database of in vitro whole-cell patch-clamp recordings from primary somatosensory and motor cortices (layers 2/3) of the adult mice (2-15 months old) from both sexes is introduced. A total of 464 current-clamp experiments from identified excitatory and inhibitory neurons are provided. Experiments include recordings with (i) Step-and-Hold protocol during which the current was transiently held at 10 steps, gradually increasing in amplitude, (ii) 'Frozen Noise' injections that model the amplitude and time-varying nature of synaptic inputs to a neuron in biological networks. All experiments follow a within neuron across drug design which includes a vehicle control and a modulation of one of the following targets in the same neuron: dopamine and its receptors D1R, D2R, serotonin 5HT1f receptor, norepinephrine Alpha1, and acetylcholine M1 receptors. Conclusions: This dataset is the first to provide a systematic and comparative insight into the role of the selected neuromodulators in controlling cellular excitability. The data will help to mechanistically address how bottom-up information processing can be modulated, providing a reference for studying neural coding characteristics and revealing the contribution of neuromodulation to information processing.  

Abstract 18708: Vascular Dysfunction in Hyperhomocysteinemia: In vitro Evidence for Endoplasmic Reticulum Stress-mediated Calcium-activated Potassium Channel Dysfunction

Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Wen-Tao Sun ◽  
Xiang-Chong Wang ◽  
Cheuk-Man Yu ◽  
Shun-Hay Pun ◽  
Qin Yang
Keyword(s):  
Endoplasmic Reticulum ◽  
Smooth Muscle ◽  
Cell Surface ◽  
Er Stress ◽  
Vascular Dysfunction ◽  
Cell Protein ◽  
Α Subunit ◽  
Whole Cell

Objectives: KCa channels play an important role in the control of vascular tone. Opening of IKCa and SKCa in endothelial cells underlies the classic EDHF pathway and promotes NO production. Smooth muscle BKCa provides a negative feedback mechanism opposing vasoconstriction and is an effector of NO and EDHF. Previous studies demonstrated homocysteine (Hcy), a risk factor for atherosclerosis, compromises NO and EDHF function, however, whether KCa is involved is poorly studied and the underlying mechanisms remain unknown. We studied the effect of Hcy on vascular KCa with the role of endoplasmic reticulum (ER) stress explored. Methods: In vitro studies were performed in porcine coronary arteries and primary cultured porcine coronary endothelial (PCECs) and smooth muscle cells (PCSMCs). IKCa and SKCa-, and BKCa-mediated relaxations were studied in endothelium-intact and -denuded arteries in a myograph. IKCa and SKCa currents in PCECs and BKCa current in PCSMCs were analyzed by whole-cell patch clamp and channel expressions were examined by western blot. Results: Hcy impairs the role of IKCa and SKCa, and BKCa in vasorelaxation. Relaxant responses to channel activators NS309 and NS1619 were attenuated and EDHF-type response was inhibited. Hcy suppressed IKCa and SKCa currents in PCECs and BKCa currents in PCSMCs. Inhibition of ER stress enhanced KCa currents and improved EDHF-type and channel activators-induced responses. Whole-cell protein levels of IKCa and SKCa remained unchanged in Hcy-exposed PCECs whereas IKCa and SKCa at cell surface were significantly decreased. Hcy lowered protein of β1 but not α subunit of BKCa in PCSMCs. The decrease in cell surface IKCa and SKCa and reduction of BKCa β1 were restored by ER stress inhibition. Further, inhibition of PERK increased BKCa β1 protein and enhanced BKCa current. Conclusion: ER stress mediates Hcy-induced vascular dysfunction through inhibition of KCa. Suppression of cell surface expression underlies ER stress-mediated IKCa and SKCa inhibition. Downregulation of BKCa β1 by PERK-ER stress pathway plays a key role in the loss of BKCa function. This study provides new mechanistic insights into the role of ER stress in vascular dysfunction. Supported by RGC GRF CUHK4774/12M & CUHK14118414, and NSFC 81200123.

scholarly journals Critical Role of Type 1 Cytokines in Controlling Initial Infection with Burkholderia mallei

2006 ◽  
Vol 74 (9) ◽  
pp. 5333-5340 ◽  
Author(s):  
Caroline A. Rowland ◽  
Ganjana Lertmemongkolchai ◽  
Alison Bancroft ◽  
Ashraful Haque ◽  
M. Stephen Lever ◽  
...  
Keyword(s):  
T Cells ◽  
Critical Role ◽  
Disease Model ◽  
Cell Mediated Immunity ◽  
Burkholderia Mallei ◽  
Monocyte Chemoattractant Protein 1 ◽  
Ifn Γ

ABSTRACT Burkholderia mallei is a gram-negative bacterium which causes the potentially fatal disease glanders in humans; however, there is little information concerning cell-mediated immunity to this pathogen. The role of gamma interferon (IFN-γ) during B. mallei infection was investigated using a disease model in which infected BALB/c mice normally die between 40 and 60 days postinfection. IFN-γ knockout mice infected with B. mallei died within 2 to 3 days after infection, and there was uncontrolled bacterial replication in several organs, demonstrating the essential role of IFN-γ in the innate immune response to this pathogen. Increased levels of IFN-γ, interleukin-6 (IL-6), and monocyte chemoattractant protein 1 were detected in the sera of immunocompetent mice in response to infection, and splenic mRNA expression of IFN-γ, IL-6, IL-12p35, and IL-27 was elevated 24 h postinfection. The effects of IL-18, IL-27, and IL-12 on stimulation of the rapid IFN-γ production were investigated in vitro by analyzing IFN-γ production in the presence of heat-killed B. mallei. IL-12 was essential for IFN-γ production in vitro; IL-18 was also involved in induction of IFN-γ, but IL-27 was not required for IFN-γ production in response to heat-killed B. mallei. The main cellular sources of IFN-γ were identified in vitro as NK cells, CD8+ T cells, and TCRγδ T cells. Our data show that B. mallei is susceptible to cell-mediated immune responses which promote expression of type 1 cytokines. This suggests that development of effective vaccines against glanders should target the production of IFN-γ.

scholarly journals Proteome Analysis of Camellia nitidissima Chi Revealed Its Role in Colon Cancer Through the Apoptosis and Ferroptosis Pathway

2021 ◽  
Vol 11 ◽  
Author(s):  
Yiwei Chen ◽  
Fan Zhang ◽  
Zhengcai Du ◽  
Jinling Xie ◽  
Lei Xia ◽  
...  
Keyword(s):  
Colon Cancer ◽  
Cancer Progression ◽  
Proteome Analysis ◽  
Heme Oxygenase 1 ◽  
Label Free ◽  
Alternative Source ◽  
Camellia Nitidissima

Colon cancer is the third most common cancer in the world with a high mortality rate. At present, surgery combined with radiotherapy and chemotherapy is the primary treatment, but patient prognosis remains poor. Traditional Chinese medicine (TCM) has become a complementary and alternative source of anti-cancer drugs. Camellia nitidissima Chi (CNC) is a TCM used to treat a variety of cancers. However, the role of CNC in cancer remains elusive, and its effect and mechanism on colon cancer have not been reported. Here, we show that CNC exerts an excellent inhibitory effect on colon cancer proliferation and apoptosis induction in vitro and in vivo. We performed label free-based quantitative proteomic analysis to evaluate the HCT116 cells treated with CNC. Our data revealed a total of 363 differentially expressed proteins, of which 157 were up-regulated and 206 down-regulated. Gene Ontology enrichment analysis showed that these proteins were involved in tumor occurrence and development through multiple biological processes such as cell proliferation, cell apoptosis, cell cycle, and cell death. Interestingly, we also found significant changes in ferroptosis pathways. The role of essential proteins glutathione peroxidase 4 (GPX4) and heme oxygenase-1 (HMOX1) were verified. CNC decreased the expression of GPX4 and increased the expression of HMOX1 at the mRNA and protein levels in vivo and in vitro. Collectively, these findings reveal that CNC regulates colon cancer progression via the ferroptosis pathway and could be an attractive treatment for colon cancer.

The role of silicon in forages: A quantitative X-Ray study

1987 ◽  
Vol 45 ◽  
pp. 416-417
Author(s):  
Janet H. Woodward ◽  
D. E. Akin
Keyword(s):  
Sodium Acetate ◽  
Dry Matter ◽  
Acetate Buffer ◽  
Plant Tissues ◽  
Sodium Acetate Buffer ◽  
X Ray ◽  
Dry Matter Digestibility ◽  
Percent Composition

Silicon (Si) is distributed throughout plant tissues, but its role in forages has not been clarified. Although Si has been suggested as an antiquality factor which limits the digestibility of structural carbohydrates, other research indicates that its presence in plants does not affect digestibility. We employed x-ray microanalysis to evaluate Si as an antiquality factor at specific sites of two cultivars of bermuda grass (Cynodon dactvlon (L.) Pers.). “Coastal” and “Tifton-78” were chosen for this study because previous work in our lab has shown that, although these two grasses are similar ultrastructurally, they differ in in vitro dry matter digestibility and in percent composition of Si.Two millimeter leaf sections of Tifton-7 8 (Tift-7 8) and Coastal (CBG) were incubated for 72 hr in 2.5% (w/v) cellulase in 0.05 M sodium acetate buffer, pH 5.0. For controls, sections were incubated in the sodium acetate buffer or were not treated.

An integrated screening method for evaluating the pulmonary toxicity of inhaled particulates: Role of microscopic techniques in assessing pulmonary macrophage clearance functions

1990 ◽  
Vol 48 (3) ◽  
pp. 826-827
Author(s):  
David B. Warheit ◽  
Lena Achinko ◽  
Mark A. Hartsky
Keyword(s):  
Bronchoalveolar Lavage ◽  
Pulmonary Toxicity ◽  
Screening Method ◽  
Pulmonary Response ◽  
Inhaled Particles ◽  
Cytochemical Analysis ◽  
Pulmonary Macrophages ◽  
Integrated Screening

There is a great need for the development of a rapid and reliable bioassay to evaluate the pulmonary toxicity of inhaled particles. A number of methods have been proposed, including lung clearance studies, bronchoalveolar lavage analysis, and in vitro cytotoxicity tests. These methods are often limited in scope inasmuch as they measure only one dimension of the pulmonary response to inhaled, instilled or incubated dusts. Accordingly, a comprehensive approach to lung toxicity studies has been developed.To validate the method, rats were exposed for 6 hours or 3 days to various concentrations of either aerosolized alpha quartz silica (Si) or carbonyl iron (CI) particles. Cells and fluids from groups of sham and dust-exposed animals were recovered by bronchoalveolar lavage (BAL). Alkaline phosphatase, LDH and protein values were measured in BAL fluids at several time points postexposure. Cells were counted and evaluated for viability, as well as differential and cytochemical analysis. In addition, pulmonary macrophages (PM) were cultured and studied for morphology, chemotaxis, and phagocytosis by scanning electron microscopy.

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