scholarly journals Interaction of Graphene Oxide Modified with Linear and Branched PEG with Monocytes Isolated from Human Blood

Nanomaterials ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 126
Author(s):  
Pavel Khramtsov ◽  
Maria Bochkova ◽  
Valeria Timganova ◽  
Anton Nechaev ◽  
Sofya Uzhviyuk ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Immune Cells ◽  
Human Peripheral Blood ◽  
Oxide Surface ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Composition And Structure ◽  
Luminescent Signal ◽  
Ros Formation ◽  
The Impact

Multiple graphene-based therapeutics have recently been developed, however potential risks related to the interaction between nanomaterials and immune cells are still poorly understood. Therefore, studying the impact of graphene oxide on various populations of immune cells is of importance. In this work, we aimed to investigate the effects of PEGylated graphene oxide on monocytes isolated from human peripheral blood. Graphene oxide nanoparticles with lateral sizes of 100–200 nm and 1–5 μm were modified with linear and branched PEG (GO-PEG). Size, elemental composition, and structure of the resulting nanoparticles were characterized. We confirmed that PEG was successfully attached to the graphene oxide surface. The influence of GO-PEG on the production of reactive oxygen species (ROS), cytokines, phagocytosis, and viability of monocytes was studied. Uptake of GO-PEG by monocytes depends on PEG structure (linear or branched). Branched PEG decreased the number of GO-PEG nanoparticles per monocyte. The viability of monocytes was not altered by co-cultivation with GO-PEG. GO-PEG decreased the phagocytosis of Escherichia coli in a concentration-dependent manner. ROS formation by monocytes was determined by measuring luminol-, lucigenin-, and dichlorodihydrofluorescein-dependent luminescence. GO-PEG decreased luminescent signal probably due to inactivation of ROS, such as hydroxyl and superoxide radicals. Some types of GO-PEG stimulated secretion of IL-10 by monocytes, but this effect did not correlate with their size or PEG structure.

scholarly journals Effects of silver-graphene oxide on seed germination and early growth of crop species

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e8387
Author(s):  
Min-Ji Kim ◽  
Woong Kim ◽  
Haegeun Chung
Keyword(s):  
Graphene Oxide ◽  
Seed Germination ◽  
Antimicrobial Agents ◽  
Germination Rate ◽  
Early Growth ◽  
Trophic Levels ◽  
Dependent Manner ◽  
Crop Species ◽  
Concentration Dependent Manner ◽  
The Impact

Due to its excellent material properties, silver-graphene oxide (Ag-GO) is being studied for diverse applications, such as antimicrobial agents, catalysts and absorbents. Such use of Ag-GO may lead to its release into terrestrial ecosystems, but little is known about the impact of Ag-GO on plants. In the present study, we determined the effects of Ag-GO on seed germination and early growth of crop species by analyzing the germination rate, growth of roots and shoots, hydrogen peroxide (H2O2) accumulation, and the uptake of Ag in alfalfa, radish and cucumber treated with 0.2–1.6 mg mL−1 of Ag-GO. Ag-GO treatment increased the shoot growth of radish at 0.2–1.6 mg mL−1 but decreased that of cucumber at 0.8 mg mL−1. In addition, Ag-GO enhanced the root elongation of radish at 0.2 mg mL−1 but inhibited that of alfalfa at 0.2, 0.8 and 1.6 mg mL−1. Ag-GO treatment induced H2O2 production in alfalfa, radish and cucumber in a concentration-dependent manner. Larger amounts of Ag accumulated in the seedlings as the concentration of Ag-GO increased, and such accumulation suggests that Ag may be transferred to higher trophic levels when plants are exposed to Ag-GO in ecosystems. Our study can, thus, serve as an important basis for setting guidelines for the release of nanomaterials into the environment.

The impact of cryopreservation on human peripheral blood leucocyte bioenergetics

2015 ◽  
Vol 128 (10) ◽  
pp. 723-733 ◽  
Author(s):  
Kevin N. Keane ◽  
Emily K. Calton ◽  
Vinicius F. Cruzat ◽  
Mario J. Soares ◽  
Philip Newsholme
Keyword(s):  
Immune Cells ◽  
Human Peripheral Blood ◽  
Coupling Efficiency ◽  
Isolated Cells ◽  
Peripheral Blood Leucocyte ◽  
Atp Production ◽  
Functional Changes ◽  
Glycolytic Activity ◽  
Bioenergetic Analysis ◽  
The Impact

Circulating immune cells are considered a source for biomarkers in health and disease, since they are exposed to nutritional, metabolic and immunological stimuli in the vasculature. Cryopreservation of leucocytes is routinely used for long-term storage and determination of phenotypic/functional changes at a later date. Exploring the role of bioenergetics and mitochondrial (dys)function in leucocytes is often examined by using freshly isolated cells. The aim of the pilot study described herein was to assess leucocyte bioenergetics in cryopreserved cells. Leucocytes were isolated from whole blood, counted and frozen in liquid nitrogen (LN2) for a period of 3 months. Cells were thawed at regular intervals and bioenergetic analysis performed using the Seahorse XFe96 flux analyser. Cryogenic storage reduced cell viability by 20%, but cell bioenergetic responses were largely intact for up to 1 month storage in LN2. However, after 1 month storage, mitochondrial function was impaired as reflected by decreasing basal respiration, ATP production, maximum (MAX) respiration, reserve capacity and coupling efficiency. Conversely, glycolytic activity was increased after 1 month, most notably the enhanced glycolytic response to 25 mM glucose without any change in glycolytic capacity. Finally, calculation of bioenergetic health index (BHI) demonstrated that this potential diagnostic parameter was sensitive to cryopreservation. The present study has demonstrated for the first time that cryopreservation of primary immune cells modified their metabolism in a time-dependent fashion, indicated by attenuated aerobic respiration and enhanced glycolytic activity. Taken together, we recommend caution in the interpretation of bioenergetic responses or BHI in cryopreserved samples.

scholarly journals Robust Magnetized Graphene Oxide Platform for In Situ Peptide Synthesis and FRET-Based Protease Detection

Sensors ◽  
2020 ◽  
Vol 20 (18) ◽  
pp. 5275
Author(s):  
Seongsoo Kim ◽  
Sang-Myung Lee ◽  
Je Pil Yoon ◽  
Namhun Lee ◽  
Jinhyo Chung ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Peptide Synthesis ◽  
Solid Phase ◽  
Solid Phase Peptide Synthesis ◽  
Resonance Energy ◽  
Precursor Solution ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Biomarker Analysis

Graphene oxide (GO)/peptide complexes as a promising disease biomarker analysis platform have been used to detect proteolytic activity by observing the turn-on signal of the quenched fluorescence upon the release of peptide fragments. However, the purification steps are often cumbersome during surface modification of nano-/micro-sized GO. In addition, it is still challenging to incorporate the specific peptides into GO with proper orientation using conventional immobilization methods based on pre-synthesized peptides. Here, we demonstrate a robust magnetic GO (MGO) fluorescence resonance energy transfer (FRET) platform based on in situ sequence-specific peptide synthesis of MGO. The magnetization of GO was achieved by co-precipitation of an iron precursor solution. Magnetic purification/isolation enabled efficient incorporation of amino-polyethylene glycol spacers and subsequent solid-phase peptide synthesis of MGO to ensure the oriented immobilization of the peptide, which was evaluated by mass spectrometry after photocleavage. The FRET peptide MGO responded to proteases such as trypsin, thrombin, and β-secretase in a concentration-dependent manner. Particularly, β-secretase, as an important Alzheimer’s disease marker, was assayed down to 0.125 ng/mL. Overall, the MGO platform is applicable to the detection of other proteases by using various peptide substrates, with a potential to be used in an automated synthesis system operating in a high throughput configuration.

scholarly journals Forced Expression of Keratin 16 Alters the Adhesion, Differentiation, and Migration of Mouse Skin Keratinocytes

2000 ◽  
Vol 11 (10) ◽  
pp. 3315-3327 ◽  
Author(s):  
Matthew Wawersik ◽  
Pierre A. Coulombe
Keyword(s):  
Mouse Skin ◽  
Cellular Level ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Keratin 16 ◽  
Skin Keratinocytes ◽  
Steady State Levels ◽  
And Migration ◽  
Mouse Skin Keratinocytes ◽  
The Impact

Injury to the skin results in an induction of keratins K6, K16, and K17 concomitant with activation of keratinocytes for reepithelialization. Forced expression of human K16 in skin epithelia of transgenic mice causes a phenotype that mimics several aspects of keratinocyte activation. Two types of transgenic keratinocytes, with forced expression of either human K16 or a K16-C14 chimeric cDNA, were analyzed in primary culture to assess the impact of K16 expression at a cellular level. High K16-C14-expressing and low K16-expressing transgenic keratinocytes behave similar to wild type in all aspects tested. In contrast, high K16-expressing transgenic keratinocytes show alterations in plating efficiency and calcium-induced differentiation, but proliferate normally. Migration of keratinocytes is reduced in K16 transgenic skin explants compared with controls. Finally, a subset of high K16-expressing transgenic keratinocytes develops major changes in the organization of keratin filaments in a time- and calcium concentration-dependent manner. These changes coincide with alterations in keratin content while the steady-state levels of K16 protein remain stable. We conclude that forced expression of K16 in progenitor skin keratinocytes directly impacts properties such as adhesion, differentiation, and migration, and that these effects depend upon determinants contained within its carboxy terminus.

scholarly journals Leukotriene B4 stimulates c-fos and c-jun gene transcription and AP-1 binding activity in human monocytes

1992 ◽  
Vol 282 (3) ◽  
pp. 625-629 ◽  
Author(s):  
J Staňková ◽  
M Rola-Pleszczynski
Keyword(s):  
Human Peripheral Blood ◽  
Leukotriene B4 ◽  
Binding Activity ◽  
Dependent Manner ◽  
Blood Monocytes ◽  
Concentration Dependent Manner ◽  
Nuclear Factors ◽  
Oncogene Products ◽  
Kinetics Of

We have examined the effect of leukotriene B4 (LTB4), a potent lipid proinflammatory mediator, on the expression of the proto-oncogenes c-jun and c-fos. In addition, we looked at the modulation of nuclear factors binding specifically to the AP-1 element after LTB4 stimulation. LTB4 increased the expression of the c-fos gene in a time- and concentration-dependent manner. The c-jun mRNA, which is constitutively expressed in human peripheral-blood monocytes at relatively high levels, was also slightly augmented by LTB4, although to a much lower extent than c-fos. The kinetics of expression of the two genes were also slightly different, with c-fos mRNA reaching a peak at 15 min after stimulation and c-jun at 30 min. Both messages rapidly declined thereafter. Stability of the c-fos and c-jun mRNA was not affected by LTB4, as assessed after actinomycin D treatment. Nuclear transcription studies in vitro showed that LTB4 increased the transcription of the c-fos gene 7-fold and the c-jun gene 1.4-fold. Resting monocytes contained nuclear factors binding to the AP-1 element, but stimulation of monocytes with LTB4 induced greater AP-1-binding activity of nuclear proteins. These results indicate that LTB4 may regulate the production of different cytokines by modulating the yield and/or the function of transcription factors such as AP-1-binding proto-oncogene products.

The cytoprotective effects of bilirubin and biliverdin on rat hepatocytes and human erythrocytes and the impact of albumin

1991 ◽  
Vol 69 (12) ◽  
pp. 828-834 ◽  
Author(s):  
Tai-Wing Wu ◽  
Doug Carey ◽  
Jun Wu ◽  
Hiroshi Sugiyama
Keyword(s):  
Rat Hepatocytes ◽  
Human Erythrocytes ◽  
Red Cells ◽  
Peroxyl Radicals ◽  
Blood Levels ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Hepatocyte Necrosis ◽  
The Impact ◽  
First Time

The hypothesis that unconjugated bilirubin and biliverdin are cytoprotective antioxidants has been examined for the first time in systems containing cells. In primary rat hepatocytes exposed to xanthine oxidase and hypoxanthine, bilirubin (0–60 μM) failed to prolong cell survival. In contrast, biliverdin (20–100 μM) markedly delayed hepatocyte necrosis in a concentration-dependent manner. When 0.3 mM of albumin was present, bilirubin (0–50 μM) became protective of hepatocytes, while biliverdin was less dramatically enhanced in its cytoprotective effect. In human erythrocytes exposed to peroxyl radicals, bilirubin and biliverdin inhibited 50% cell lysis at lower concentrations than Trolox and ascorbate, respectively. Albumin alone appeared less cytoprotective in red cells than in hepatocytes, but its presence enhanced the effects of both pigments on erythrocytes. Of probable physiologic relevance, bilirubin with albumin present or biliverdin alone protected hepatocytes substantially (and to a lesser extent red cells) at the normal blood levels of bilirubin (3.4–26 μM). Moreover, the fact that the pigments are cytoprotective at higher bilirubin levels (e.g., 50–100 μM) tempts the speculation that they may be circulating cytoprotectors of overlooked importance in jaundice.Key words: cytoprotection, biliverdin, bilirubin, albumin.

scholarly journals Cell-free Expression of Proton-Coupled Folate Transporter in the Presence of Nanodiscs

2021 ◽  
Author(s):  
Hoa Quynh Do ◽  
Carla M Bassil ◽  
Elizabeth I Andersen ◽  
Michaela Jansen
Keyword(s):  
Tumor Cells ◽  
Plasma Membranes ◽  
In Vitro Translation ◽  
Translation System ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
E Coli ◽  
Membrane Scaffold ◽  
The Impact

The Proton-Coupled Folate Transporter (PCFT) is a transmembrane transport protein that controls the absorption of dietary folates in the small intestine. PCFT also mediates uptake of chemotherapeutically used antifolates into tumor cells. PCFT has been identified within lipid rafts observed in phospholipid bilayers of plasma membranes, a micro environment that is altered in tumor cells. The present study aimed at investigating the impact of different lipids within Lipid-protein nanodiscs (LPNs), discoidal lipid structures stabilized by membrane scaffold proteins, to yield soluble PCFT expression in an E. coli lysate-based cell-free transcription/translation system. In the absence of detergents or lipids, we observed PCFT quantitatively as precipitate in this system. We then explored the ability of LPNs to support solubilized PCFT expression when present during in-vitro translation. LPNs consisted of either dimyristoyl phosphatidylcholine (DMPC), palmitoyl-oleoyl phosphatidylcholine (POPC), or dimyristoyl phosphatidylglycerol (DMPG). While POPC did not lead to soluble PCFT expression, both DMPG and DMPC supported PCFT translation directly into LPNs, the latter in a concentration dependent manner. The results obtained through this study provide insights into the lipid preferences of PCFT. Membrane-embedded or solubilized PCFT will enable further studies with diverse biophysical approaches to enhance the understanding of the structure and molecular mechanism of folate transport through PCFT.

scholarly journals (R,S)-Ketamine Metabolites (R,S)-norketamine and (2S,6S)-hydroxynorketamine Increase the Mammalian Target of Rapamycin Function

2014 ◽  
Vol 121 (1) ◽  
pp. 149-159 ◽  
Author(s):  
Rajib K. Paul ◽  
Nagendra S. Singh ◽  
Mohammed Khadeer ◽  
Ruin Moaddel ◽  
Mitesh Sanghvi ◽  
...  
Keyword(s):  
Parent Compound ◽  
Mammalian Target Of Rapamycin ◽  
Mtor Pathway ◽  
Target Of Rapamycin ◽  
Dependent Manner ◽  
Α7 Nicotinic Acetylcholine Receptor ◽  
Concentration Dependent Manner ◽  
Pheochromocytoma Cells ◽  
The Impact

Abstract Background: Subanesthetic doses of (R,S)-ketamine are used in the treatment of neuropathic pain and depression. In the rat, the antidepressant effects of (R,S)-ketamine are associated with increased activity and function of mammalian target of rapamycin (mTOR); however, (R,S)-ketamine is extensively metabolized and the contribution of its metabolites to increased mTOR signaling is unknown. Methods: Rats (n = 3 per time point) were given (R,S)-ketamine, (R,S)-norketamine, and (2S,6S)-hydroxynorketamine and their effect on the mTOR pathway determined after 20, 30, and 60 min. PC-12 pheochromocytoma cells (n = 3 per experiment) were treated with escalating concentrations of each compound and the impact on the mTOR pathway was determined. Results: The phosphorylation of mTOR and its downstream targets was significantly increased in rat prefrontal cortex tissue by more than ~2.5-, ~25-, and ~2-fold, respectively, in response to a 60-min postadministration of (R,S)-ketamine, (R,S)-norketamine, and (2S,6S)-hydroxynorketamine (P < 0.05, ANOVA analysis). In PC-12 pheochromocytoma cells, the test compounds activated the mTOR pathway in a concentration-dependent manner, which resulted in a significantly higher expression of serine racemase with ~2-fold increases at 0.05 nM (2S,6S)-hydroxynorketamine, 10 nM (R,S)-norketamine, and 1,000 nM (R,S)-ketamine. The potency of the effect reflected antagonistic activity of the test compounds at the α7-nicotinic acetylcholine receptor. Conclusions: The data demonstrate that (R,S)-norketamine and (2S,6S)-hydroxynorketamine have potent pharmacological activity both in vitro and in vivo and contribute to the molecular effects produced by subanesthetic doses of (R,S)-ketamine. The results suggest that the determination of the mechanisms underlying the antidepressant and analgesic effects of (R,S)-ketamine requires a full study of the parent compound and its metabolites.

scholarly journals Size of Cells and Physicochemical Properties of Membranes are Related to Flavor Production during Sake Brewing in the Yeast Saccharomyces cerevisiae

Membranes ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 440
Author(s):  
Tsuyoshi Yoda ◽  
Tomoaki Saito
Keyword(s):  
Isoamyl Alcohol ◽  
Lipid Vesicles ◽  
Caproic Acid ◽  
Yeast Cells ◽  
Dependent Manner ◽  
Yeast Saccharomyces Cerevisiae ◽  
Concentration Dependent Manner ◽  
Generalized Polarization ◽  
Flavor Components ◽  
The Impact

Ethyl caproate (EC) and isoamyl acetate (IA) are key flavor components of sake. Recently, attempts have been made to increase the content of good flavor components, such as EC and IA, in sake brewing. However, the functions of EC and IA in yeast cells remain poorly understood. Therefore, we investigated the effects of EC and IA using cell-sized lipid vesicles. We also investigated lipid vesicles containing EC and/or caproic acid (CA) as well as IA and/or isoamyl alcohol (IAA). CA and IAA are precursors of EC and IA, respectively, and are important flavors in sake brewing. The size of a vesicle is influenced by flavor compounds and their precursors in a concentration-dependent manner. We aimed to establish the conditions in which the vesicles contained more flavors simultaneously and with different ratios. Interestingly, vesicles were largest in a mixture of 50% of 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) with 25% EC and 25% CA or a mixture of 50% DOPC with 25% IA and 25% IAA. The impact of flavor additives on membrane fluidity was also studied using Laurdan generalized polarization. During the production process, flavors may regulate the fluidity of lipid membranes.

scholarly journals The Immunomodulatory Effects of Nidus Vespae on Human Peripheral Blood Immune CellsIn Vitro

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Ming Zhu ◽  
Yang Ling ◽  
Qiufeng Qi ◽  
Yaping Zhang ◽  
Yanqing Bao ◽  
...  
Keyword(s):  
B Cells ◽  
Tumor Cell ◽  
Cell Viability ◽  
Immune Cells ◽  
Peripheral Blood ◽  
Human Peripheral Blood ◽  
Cell Counting ◽  
Dependent Manner ◽  
Immunomodulatory Effects ◽  
Gastric Cancer Cells

Nidus Vespae has been used in traditional Chinese medicine (TCM) to treat various cancers, but the underlying mechanisms were not yet clarified. This study was to investigate the effect of Nidus Vespae decoction (NVD) on tumor cell viability and immunoregulating functions of human peripheral blood immune cells. The effects on tumor cell viability, peripheral blood mononuclear cell (PBMC) proliferation activity, and the tumor cell phagocytosis of monocytes were evaluated by cell counting kit-8. Tumor-killing activity of cytotoxic T lymphocyte (CTL) was analyzed by51Cr releasing assay. IgG production of B cells and cytokine (TNF-αand IL-6) secretion of monocytes were determined by ELISA method. Data showed that NVD has no significant inhibiting effects on gastric cancer cells growth. Nevertheless, it could obviously promote PBMC proliferation in a time- and concentration-dependent manner. After treatment with NVD, the CTL cytotoxicity against SGC-7901 was significantly greater than control. The TNF-αand IL-6 secretion of monocytes and the IgG production of B cells also increased remarkably. Furthermore, NVD could significantly promote the phagocytosis of monocytes on tumor cells. These results suggest that NVD appears to have an immunoenhancing effect on immune cells, indicating that Nidus Vespae is worth exploring for immunomodulatory effects in tumor treatment.

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