scholarly journals Astrocytes Are More Vulnerable than Neurons to Silicon Dioxide Nanoparticle Toxicity in Vitro

Toxics ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 51
Author(s):  
Jorge Humberto Limón-Pacheco ◽  
Natalie Jiménez-Barrios ◽  
Alejandro Déciga-Alcaraz ◽  
Adriana Martínez-Cuazitl ◽  
Mónica Maribel Mata-Miranda ◽  
...  
Keyword(s):  
Nucleic Acids ◽  
Silicon Dioxide ◽  
Culture Media ◽  
Brain Cell ◽  
Attenuated Total Reflection ◽  
Random Coil ◽  
Silicon Dioxide Nanoparticles ◽  
Neurotoxic Effects ◽  
Α Helix

Some studies have shown that silicon dioxide nanoparticles (SiO2-NPs) can reach different regions of the brain and cause toxicity; however, the consequences of SiO2-NPs exposure on the diverse brain cell lineages is limited. We aimed to investigate the neurotoxic effects of SiO2-NP (0–100 µg/mL) on rat astrocyte-rich cultures or neuron-rich cultures using scanning electron microscopy, Attenuated Total Reflection-Fourier Transform Infrared spectroscopy (ATR-FTIR), FTIR microspectroscopy mapping (IQ mapping), and cell viability tests. SiO2-NPs were amorphous particles and aggregated in saline and culture media. Both astrocytes and neurons treated with SiO2-NPs showed alterations in cell morphology and changes in the IR spectral regions corresponding to nucleic acids, proteins, and lipids. The analysis by the second derivative revealed a significant decrease in the signal of the amide I (α-helix, parallel β-strand, and random coil) at the concentration of 10 µg/mL in astrocytes but not in neurons. IQ mapping confirmed changes in nucleic acids, proteins, and lipids in astrocytes; cell death was higher in astrocytes than in neurons (10–100 µg/mL). We conclude that astrocytes were more vulnerable than neurons to SiO2-NPs toxicity. Therefore, the evaluation of human exposure to SiO2-NPs and possible neurotoxic effects must be followed up.

Phospholipids modulate the biophysical properties and vasoactivity of PACAP-(1—38)

2002 ◽  
Vol 93 (4) ◽  
pp. 1377-1383 ◽  
Author(s):  
Takaya Tsueshita ◽  
Salil Gandhi ◽  
Hayat Önyüksel ◽  
Israel Rubinstein
Keyword(s):  
Conformational Transition ◽  
Critical Micellar Concentration ◽  
Random Coil ◽  
Cheek Pouch ◽  
Hamster Cheek Pouch ◽  
Pituitary Adenylate Cyclase ◽  
Peripheral Microcirculation ◽  
Α Helix

The purpose of this study was to elucidate the interactions between pituitary adenylate cyclase-activating peptide (PACAP)-(1—38) and phospholipids in vitro and to determine whether these phenomena modulate, in part, the vasorelaxant effects of the peptide in the intact peripheral microcirculation. We found that the critical micellar concentration of PACAP-(1—38) was 0.4–0.9 μM. PACAP-(1—38) significantly increased the surface tension of a dipalmitoylphosphatidylcholine monolayer and underwent conformational transition from predominantly random coil in saline to α-helix in the presence of distearoyl-phosphatidylethanolamine-polyethylene glycol (molecular mass of 2,000 Da) sterically stabilized phospholipid micelles (SSM) ( P < 0.05). Using intravital microscopy, we found that aqueous PACAP-(1—38) evoked significant concentration-dependent vasodilation in the intact hamster cheek pouch that was significantly potentiated when PACAP-(1—38) was associated with SSM ( P < 0.05). The vasorelaxant effects of aqueous PACAP-(1—38) were mediated predominantly by PACAP type 1 (PAC1) receptors, whereas those of PACAP-(1—38) in SSM predominantly by PACAP/vasoactive intestinal peptide type 1 and 2 (VPAC1/VPAC2) receptors. Collectively, these data indicate that PACAP-(1—38) self-associates and interacts avidly with phospholipids in vitro and that these phenomena amplify peptide vasoactivity in the intact peripheral microcirculation.

scholarly journals Biocompatibility of cerium dioxide and silicon dioxide nanoparticles with endothelial cells

2014 ◽  
Vol 5 ◽  
pp. 1795-1807 ◽  
Author(s):  
Claudia Strobel ◽  
Martin Förster ◽  
Ingrid Hilger
Keyword(s):  
Endothelial Cells ◽  
Silicon Dioxide ◽  
Cerium Dioxide ◽  
Culture Media ◽  
Cell Activity ◽  
Human Beings ◽  
Silicon Dioxide Nanoparticles ◽  
Inflammatory Reactions ◽  
Nanoparticle Exposure

Cerium dioxide (CeO2) and silicon dioxide (SiO2) nanoparticles are of widespread use in modern life. This means that human beings are markedly exposed to them in their everyday life. Once passing biological barriers, these nanoparticles are expected to interact with endothelial cells, leading to systemic alterations with distinct influences on human health. In the present study we observed the metabolic impact of differently sized CeO2 (8 nm; 35 nm) and SiO2 nanoparticles (117 nm; 315 nm) on immortalized human microvascular (HMEC-1) and primary macrovascular endothelial cells (HUVEC), with particular focus on the CeO2 nanoparticles. The characterization of the CeO2 nanoparticles in cell culture media with varying serum content indicated a steric stabilization of nanoparticles due to interaction with proteins. After cellular uptake, the CeO2 nanoparticles were localized around the nucleus in a ring-shaped manner. The nanoparticles revealed concentration and time, but no size-dependent effects on the cellular adenosine triphosphate levels. HUVEC reacted more sensitively to CeO2 nanoparticle exposure than HMEC-1. This effect was also observed in relation to cytokine release after nanoparticle treatment. The CeO2 nanoparticles exhibited a specific impact on the release of diverse proteins. Namely, a slight trend towards pro-inflammatory effects, a slight pro-thrombotic impact, and an increase of reactive oxygen species after nanoparticle exposure were observed with increasing incubation time. For SiO2 nanoparticles, concentration- and time-dependent effects on the metabolic activity as well as pro-inflammatory reactions were detectable. In general, the effects of the investigated nanoparticles on endothelial cells were rather insignificant, since the alterations on the metabolic cell activity became visible at a nanoparticle concentration that is by far higher than those expected to occur in the in vivo situation (CeO2 nanoparticles: 100 µg/mL; SiO2 nanoparticles: 10 µg/mL).

Structural Changes of Almost Completely Inactivated Papain with Higher Concentration of Parachloromercuribenzoic Acid

2019 ◽  
Vol 11 (5) ◽  
pp. 704-710
Author(s):  
Xueying Liu ◽  
Xiaoli Cao ◽  
Min Li ◽  
Yinyan Chen ◽  
Xiaojuan Li ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Structural Changes ◽  
Binding Pocket ◽  
Enzyme Engineering ◽  
Attenuated Total Reflection ◽  
Random Coil ◽  
Inhibition Mechanism ◽  
Hydrophobic Force ◽  
Key Functional Groups ◽  
Α Helix

A hydrolysis of casein by papain was carried out to explore interaction between parachloromercuribenzoic acid (PCMB) and papain through Attenuated Total Reflection Flourier transformed Infrared Spectroscopy (ATR-FTIR), Trp intrinsic fluorescence spectroscopy and molecular docking analysis. Papain activity was almost completely inactivated when PCMB concentration reached to 10–4 mol/L or higher. The content of α-helix was decreased from 36.79% to 19.79% even up to 17%. On the other hand, the content of β-sheet was decreased from 13.41% to 11.57% by a little degree of 1.84%. However, the contents of β-turn, random coil and intermolecular β-sheet aggregates were elevated by different degree of 2.67%, 8.87% and 7.3%, respectively at the papain exposure of 10–4 mol/L PCMB solution. PCMB could bind to papain mainly through hydrophobic force and hydrogen bonding. The hydrogen bond between PCMB and Gly66; while, the hydrophobic bonds between PCMB and Trp26 in the ligand-binding pocket of papain might be the key functional groups for the inhibition of papain activity. The L-domain of papain was destructed, leading to the inactivation and fluorescence quenching of papain. The inhibition mechanism of papain activity by 10–4mol/L PCMB was involved the formation of hydrophobic force and hydrogen bond between PCMB and papain. This attempt successfully brought forth the application of computational approaches to dissect the inhibition mechanism and directed design in enzyme engineering area.

The effect of single and combined exposures to magnetite and polymorphous silicon dioxide nanoparticles on the human A549 cell line: in vitro study

2019 ◽  
Vol 26 (31) ◽  
pp. 31752-31762 ◽  
Author(s):  
Athena Rafieepour ◽  
Mansour R. Azari ◽  
Fariba Khodagholi ◽  
Jalal Pourahmad Jaktaji ◽  
Yadollah Mehrabi ◽  
...  
Keyword(s):  
Silicon Dioxide ◽  
Cell Line ◽  
A549 Cell ◽  
In Vitro Study ◽  
Vitro Study ◽  
A549 Cell Line ◽  
Silicon Dioxide Nanoparticles ◽  
Combined Exposures ◽  
Human A549

Goldfish spexin: solution structure and novel function as a satiety factor in feeding control

2013 ◽  
Vol 305 (3) ◽  
pp. E348-E366 ◽  
Author(s):  
Matthew K. H. Wong ◽  
Kong Hung Sze ◽  
Ting Chen ◽  
Chi Kong Cho ◽  
Henry C. H. Law ◽  
...  
Keyword(s):  
Solution Structure ◽  
Brain Cell ◽  
Molecular Surface ◽  
Transcript Expression ◽  
Mrna Levels ◽  
Similar Treatment ◽  
Fish Model ◽  
Α Helix

Spexin (SPX) is a neuropeptide identified recently by bioinformatic approach. At present not much is known about its biological actions, and comparative studies of SPX in nonmammalian species are still lacking. To examine the structure and function of SPX in fish model, SPX was cloned in goldfish and found to be highly comparable with its mammalian counterparts. As revealed by NMR spectroscopies, goldfish SPX is composed of an α-helix from Gln5 to Gln14 with a flexible NH2 terminus from Asn1 to Pro4, and its molecular surface is largely hydrophobic except for Lys11 as the only charged residue in the helical region. In goldfish, SPX transcripts were found to be widely expressed in various tissues, and protein expression of SPX was also detected in the brain. In vivo feeding studies revealed that SPX mRNA levels in the telencephalon, optic tectum, and hypothalamus of goldfish brain could be elevated by food intake. However, brain injection of goldfish SPX inhibited both basal and NPY- or orexin-induced feeding behavior and food consumption. Similar treatment also reduced transcript expression of NPY, AgRP, and apelin, with concurrent rises in CCK, CART, POMC, MCH, and CRH mRNA levels in different brain areas examined. The differential effects of SPX treatment on NPY, CCK, and MCH transcript expression could also be noted in vitro in goldfish brain cell culture. Our studies for the first time unveil the solution structure of SPX and its novel function as a satiety factor through differential modulation of central orexigenic and anorexigenic signals.

scholarly journals Imaging of Oral SCC Cells by Raman Micro-Spectroscopy Technique

Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3640
Author(s):  
Hidetaka Kinoshita ◽  
Norio Miyoshi ◽  
Toshiyuki Ogasawara
Keyword(s):  
Nucleic Acids ◽  
Molecular Conformation ◽  
Molecular Structures ◽  
Random Coil ◽  
Malignant Tissue ◽  
Spectroscopy Technique ◽  
Cell Level ◽  
Frozen Tissue ◽  
Α Helix ◽  
Β Sheet

We used Raman micro-spectroscopy technique to analyze the molecular changes associated with oral squamous cell carcinoma (SCC) cells in the form of frozen tissue. Previously, Raman micro-spectroscopy technique on human tissue was mainly based on spectral analysis, but we worked on imaging of molecular structure. In this study, we evaluated the distribution of four components at the cell level (about 10 μm) to describe the changes in protein and molecular structures of protein belonging to malignant tissue. We analyzed ten oral SCC samples of five patients without special pretreatments of the use of formaldehyde. We obtained cell level images of the oral SCC cells at various components (peak at 935 cm−1: proline and valine, 1004 cm−1: phenylalanine, 1223 cm−1: nucleic acids, and 1650 cm−1: amide I). These mapping images of SCC cells showed the distribution of nucleic acids in the nuclear areas; meanwhile, proline and valine, phenylalanine, and amide I were detected in the cytoplasm areas of the SCC cells. Furthermore, the peak of amide I in the cancer area shifts to the higher wavenumber side, which indicates the α-helix component may decrease in its relative amounts of protein in the β-sheet or random coil conformation. Imaging of SCC cells with Raman micro-spectroscopy technique indicated that such a new observation of cancer cells is useful for analyzing the detailed distribution of various molecular conformation within SCC cells.

scholarly journals Chitosan, Nisin, Silicon Dioxide Nanoparticles Coating Films Effects on Blueberry (Vaccinium myrtillus) Quality

Coatings ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 962
Author(s):  
Rok Eldib ◽  
Ebtihal Khojah ◽  
Abeer Elhakem ◽  
Nada Benajiba ◽  
Mahmoud Helal
Keyword(s):  
Silicon Dioxide ◽  
Ambient Temperature ◽  
Chitosan Film ◽  
Decay Rates ◽  
Anthocyanin Content ◽  
Silicon Dioxide Nanoparticles ◽  
Coating Films ◽  
Chitosan Coating

Chitosan coating plus silicon dioxide nanoparticles and nisin were applied on fresh blueberry samples in order to find out safety packaging assay during the post-harvest process. Studies were performed in-vitro for fruit quality as physicochemical parameters and oxidation, while microbiological analyses as molds/yeast and mesophilics populations were examined in-vivo. The selected silicon dioxide nanoparticles 1% and nisin 1%, were added into a chitosan solution, which resulted in four groups of coated blueberries. After storage at ambient temperature, fruits were examined for two, four, six, and eight days. It was noticed that the hardness, chewiness, and cohesiveness of all blueberry samples were increased during the storage. Chitosan-nano-silicon dioxide (CHN-Nano) and (CHN-N-Nano) with the addition of nisin helped to control shrinking (38.52%) and decay rates (8.61%). Moreover, (CHN-N-Nano) reported the lowest L* values (10.54) for the color index, and inhibited the microbial populations (3.60 and 2.73 log CFU/g) for molds/yeast and mesophilics, respectively. (CHN-Nano) reported the lowest value for ph (2.61) and the highest for anthocyanin content (75.19 cyanidin-3-glucoside mg/100 g). The chitosan coating substantially maintained Vitamin C (7.34 mg/100 g) and polyphenoloxidase (PPO) (558.03 U min−1·g−1). The results suggest that nano-material with chitosan film coatings that contained nisin were effective for fresh blueberry preservation under ambient temperature.

scholarly journals Multiomics study of a heterotardigrade, Echinisicus testudo, suggests convergent evolution of anhydrobiosis-related proteins in Tardigrada

2020 ◽  
Author(s):  
Yumi Murai ◽  
Maho Yagi-Utsumi ◽  
Masayuki Fujiwara ◽  
Masaru Tomita ◽  
Koichi Kato ◽  
...  
Keyword(s):  
Water Content ◽  
Molecular Mechanism ◽  
Convergent Evolution ◽  
Structural Changes ◽  
Extreme Environments ◽  
Random Coil ◽  
Related Protein ◽  
Α Helix ◽  
Related Proteins

AbstractMany limno-terrestrial tardigrades can enter an ametabolic state upon desiccation, in which the animals can withstand extreme environments. To date, studies of the molecular mechanism have predominantly investigated the class Eutardigrada, and that in the Heterotardigrada, remains elusive. To this end, we report a multiomics study of the heterotardigrade Echiniscus testudo, which is one of the most desiccation-tolerant species. None of the previously identified tardigrade-specific anhydrobiosis-related genes was conserved, while the loss and expansion of existing pathways were partly shared. Furthermore, we identified two families of novel abundant heat-soluble proteins and the proteins exhibited structural changes from random coil to α-helix as the water content decreased in vitro. These characteristics are analogous to those of anhydrobiosis-related protein in eutardigrades, while there is no conservation at the sequence level. Our results suggest that Heterotardigrada have partly shared but distinct anhydrobiosis machinery compared with Eutardigrada, possibly due to convergent evolution within Tardigrada.

scholarly journals Effect of Silicon Dioxide Nanoparticles on Growth Improvement of Banana Shoots In Vitro within Rooting Stage

2017 ◽  
Vol 8 (9) ◽  
pp. 913-916 ◽  
Author(s):  
M. EL-Kady ◽  
M. El-Boray ◽  
A. Shalan ◽  
Lamiaa Mohamed
Keyword(s):  
Silicon Dioxide ◽  
Silicon Dioxide Nanoparticles
Sign in / Sign up

Export Citation Format

Share Document