Transmission electron microscopy of the benzbromarone-induced change in mitochondrial morphology in HepG2 cells

Background: Right ventricular dysfunction (RVD) is the leading cause of death in pulmonary arterial hypertension (PAH), but no RV-specific therapy exists. We showed microtubule-mediated junctophilin-2 dysregulation (MT-JPH2 pathway) causes t-tubule disruption and RVD in rodent PAH, but the druggable regulators of this critical pathway are unknown. GP130 (glycoprotein 130) activation induces cardiomyocyte microtubule remodeling in vitro; however, the effects of GP130 signaling on the MT-JPH2 pathway and RVD resulting from PAH are undefined. Methods: Immunoblots quantified protein abundance, quantitative proteomics defined RV microtubule-interacting proteins (MT-interactome), metabolomics evaluated the RV metabolic signature, and transmission electron microscopy assessed RV cardiomyocyte mitochondrial morphology in control, monocrotaline, and monocrotaline-SC-144 (GP130 antagonist) rats. Echocardiography and pressure-volume loops defined the effects of SC-144 on RV-pulmonary artery coupling in monocrotaline rats (8–16 rats per group). In 73 patients with PAH, the relationship between interleukin-6, a GP130 ligand, and RVD was evaluated. Results: SC-144 decreased GP130 activation, which normalized MT-JPH2 protein expression and t-tubule structure in the monocrotaline RV. Proteomics analysis revealed SC-144 restored RV MT-interactome regulation. Ingenuity pathway analysis of dysregulated MT-interacting proteins identified a link between microtubules and mitochondrial function. Specifically, SC-144 prevented dysregulation of electron transport chain, Krebs cycle, and the fatty acid oxidation pathway proteins. Metabolomics profiling suggested SC-144 reduced glycolytic dependence, glutaminolysis induction, and enhanced fatty acid metabolism. Transmission electron microscopy and immunoblots indicated increased mitochondrial fission in the monocrotaline RV, which SC-144 mitigated. GP130 antagonism reduced RV hypertrophy and fibrosis and augmented RV-pulmonary artery coupling without altering PAH severity. In patients with PAH, higher interleukin-6 levels were associated with more severe RVD (RV fractional area change 23±12% versus 30±10%, P =0.002). Conclusions: GP130 antagonism reduces MT-JPH2 dysregulation, corrects metabolic derangements in the RV, and improves RVD in monocrotaline rats.

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Quercetin ameliorates mitochondrial dysfunction and mitigates methamphetamine-induced anxiety-like behavior

10.1101/2021.06.29.450268 ◽

2021 ◽

Author(s):

Fengrong Chen ◽

Jiaxue Sun ◽

Yongjin Zhang ◽

Yicong Dai ◽

Zherui Zhang ◽

...

Keyword(s):

Electron Microscopy ◽

Transmission Electron Microscopy ◽

Oxygen Consumption ◽

Mitochondrial Dysfunction ◽

Consumption Rate ◽

Mitochondrial Morphology ◽

Transmission Electron ◽

Anxiety Behavior ◽

And Function

Methamphetamine (MA) abuse results in neurotoxic outcomes, including increased anxiety and depression, during both MA use and withdrawal. Although numerous studies have reported an association between MA exposure and anxiety, the underlying mechanism remains elusive. In this study, escalating dose of MA was used to establish an MA-treated mouse model presenting anxiety behavior. RNA seq was then performed to profile the gene expression patterns in the hippocampus (HIPP). Differentially expressed genes (DEGs) were identified and function enrichment analysis was conducted to explore the underlying mechanisms. Quercetin as an mitochondria protector was used in vivo and in vitro. The C57BL/6J mice were co-treated with 50 mg/kg Quercetin and escalating MA. Anxiety behavior was evaluated by utilizing the elevated plus maze and the open field test. Transmission electron microscopy and immunohistochemistry were conducted to study the pathology of MA-inducced anxiety . The effects of MA and Quercetin on astrocytes were investigated by fluorescence staining, transmission electron microscopy, flow cytometry, and oxygen consumption rate. Western blot and qPCR were performed to analyze altered protein and gene levels of HIPP in mice and astrtocytes. The results demonstrated that forteen upregulated differentially expressed genes were identified and significantly enriched in signaling pathways related to psychiatric disorders and mitochondrial function. Interestingly, we found that quercetin was able to alleviate MA-induced anxiety-like behavior by improving neuron number and mitochondria injury. Mechanistically, quercetin can mitigate aberrant mitochondrial morphology and mitochondrial dysfunction not only by decreasing the levels of total cytoplasmic reactive oxygen species (ROS), mitochondria-derived ROS (mtROS), and mitochondrial membrane potential (MMP), but also increasing the oxygen consumption rate (OCR) and mitochondrial ATP production in vitro, indicating Quercetin ameliorated MA-induced anxiety-like behavior by modifying mitochondrial morphology and function. Furthermore, quercetin reversed OPA1 and DRP1 expression in astrocytes, and mitigated astrocyte activation and the release of inflammatory factors, which can trigger neuronal apoptosis and synaptic loss. Taken together, we provided evidence showing that MA can induce anxiety-like behavior via the induction of oxidative stress and mitochondrial dysfunction. Quercetin exerted antipsychotic activity through mitochondrial modulation, suggesting its potential for further therapeutic development in MA-induced anxiety.

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Effection of cordycepin on Inhibition proliferation by activating autophagy in HepG2 cell

E3S Web of Conferences ◽

10.1051/e3sconf/202018902026 ◽

2020 ◽

Vol 189 ◽

pp. 02026

Author(s):

Li Tianjiao ◽

Cheng Bijun ◽

Li Fenglin

Keyword(s):

Electron Microscopy ◽

Transmission Electron Microscopy ◽

Cell Proliferation ◽

Hepg2 Cells ◽

Active Component ◽

Liver Tumors ◽

Biological Activities ◽

Related Protein ◽

Immunofluorescence Method ◽

Transmission Electron

Cordycepin, the main active component of Cordyceps militaris, possesses a variety of biological activities. This paper investigated the inhibition of cordycepin on liver tumors. HepG2 cells were treated with cordycepin. The inhibition rates of cell proliferation was detected by MTT, LC3 protein was detected by immunofluorescence method, autophagy was observed by transmission electron microscopy, autophagy related protein was detected by Western blot. The results showed that cordycepin significantly inhibited the proliferation of HepG2 cells, and significantly increased the expression level of LC3 protein (<0.05). and the autophagy increased in the cells. The Atg-related protein analysis showed that cordycepin significantly reduced the p-mTOR / β-actin ratio and p62 / β-actin ratio (<0.01), and significantly increased the LC3II/LC3I ratio (P<0.01). The results suggested that cordycepin inhibited the proliferation by activating autophagy in HepG2 cells.

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Preparation, Characterization, and Cytotoxicity of Various Chitosan Nanoparticles

Journal of Nanomaterials ◽

10.1155/2013/183871 ◽

2013 ◽

Vol 2013 ◽

pp. 1-6 ◽

Cited By ~ 4

Author(s):

Qian Yao ◽

Wei Liu ◽

Xiao-Jun Gou ◽

Xiao-Qiang Guo ◽

Jun Yan ◽

...

Keyword(s):

Electron Microscopy ◽

Transmission Electron Microscopy ◽

Biological Activity ◽

Hepg2 Cells ◽

Drug Loading ◽

Chitosan Nanoparticles ◽

Inhibitory Effect ◽

Hepatic Carcinoma ◽

Transmission Electron ◽

Diverse Biological Activity

Chitosan nanoparticles (CS-NPs) without drug loading have diverse biological activity. In this study, we prepared CS-NPs, CS-NPs solidified by different amount of glutaraldehyde, and CS-NPs modified with either biotin (B-CS-NPs) or biotin and avidin (A-B-CS-NPs) and examined their cytotoxicity on HepG2 cells. The morphology and size were measured by transmission electron microscopy and photon correction spectroscopy, respectively. The extent of solidification was validated by the approach of sonication. Biotin connect density on the surface of B-CS-NPs and A-B-CS-NPs was determined by biotin assay kit. The results showed that most of the NPs were round and their mean sizes were all below 300 nm. Biotin connect density of B-CS-NPs and A-B-CS-NPs was 2.18 ± 0.36 and 1.26 ± 0.11 mol biotin/mol CS, respectively. At relatively low concentration, CS-NPs with higher extent of solidification exhibited more vigorous inhibitory effect against HepG2 cells than those without solidification. When NPs were incubated with cancer cells for 48 h, compared with CS-NPs, the anticancer activity of B-CS-NPs and A-B-CS-NPs was enhanced significantly(P<0.05). In addition, A-B-CS-NPs showed superior cytotoxicity over B-CS-NPs. This study demonstrates that modification with biotin and avidin may be an efficient way in improving antitumor activity of CS-NPs against hepatic carcinoma.

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Techniques for Transmission Electron Microscopy of Fiber-Matrix Interfaces in Aluminum Alloy-Boron Composites by Ion Erosio

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100065079 ◽

1971 ◽

Vol 29 ◽

pp. 204-205

Author(s):

G. G. Shaw

Keyword(s):

Electron Microscopy ◽

Transmission Electron Microscopy ◽

Aluminum Alloy ◽

Electron Beam ◽

Pure Aluminum ◽

Ion Milling ◽

Transmission Electron ◽

Fiber Matrix ◽

Ion Erosion ◽

Row Of Fibers

The morphology and composition of the fiber-matrix interface can best be studied by transmission electron microscopy and electron diffraction. For some composites satisfactory samples can be prepared by electropolishing. For others such as aluminum alloy-boron composites ion erosion is necessary.When one wishes to examine a specimen with the electron beam perpendicular to the fiber, preparation is as follows: A 1/8 in. disk is cut from the sample with a cylindrical tool by spark machining. Thin slices, 5 mils thick, containing one row of fibers, are then, spark-machined from the disk. After spark machining, the slice is carefully polished with diamond paste until the row of fibers is exposed on each side, as shown in Figure 1.In the case where examination is desired with the electron beam parallel to the fiber, preparation is as follows: Experimental composites are usually 50 mils or less in thickness so an auxiliary holder is necessary during ion milling and for easy transfer to the electron microscope. This holder is pure aluminum sheet, 3 mils thick.

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Direct Observation of Heat Exchanger Deposits by Cross Sectioning

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100061835 ◽

1967 ◽

Vol 25 ◽

pp. 364-365

Author(s):

R. W. Anderson ◽

D. L. Senecal

Keyword(s):

Electron Microscopy ◽

Transmission Electron Microscopy ◽

Heat Exchanger ◽

Direct Observation ◽

Cross Sections ◽

Preparation Method ◽

Specimen Preparation ◽

Flowing Water ◽

Transmission Electron ◽

Deposit Layer

A problem was presented to observe the packing densities of deposits of sub-micron corrosion product particles. The deposits were 5-100 mils thick and had formed on the inside surfaces of 3/8 inch diameter Zircaloy-2 heat exchanger tubes. The particles were iron oxides deposited from flowing water and consequently were only weakly bonded. Particular care was required during handling to preserve the original formations of the deposits. The specimen preparation method described below allowed direct observation of cross sections of the deposit layers by transmission electron microscopy.The specimens were short sections of the tubes (about 3 inches long) that were carefully cut from the systems. The insides of the tube sections were first coated with a thin layer of a fluid epoxy resin by dipping. This coating served to impregnate the deposit layer as well as to protect the layer if subsequent handling were required.

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Phase Transformations in Ti-7w/oMo-3w/oMe Alloy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100052584 ◽

1974 ◽

Vol 32 ◽

pp. 514-515

Author(s):

S. Fujishiro

Keyword(s):

Electron Microscopy ◽

Mechanical Properties ◽

Transmission Electron Microscopy ◽

Tensile Strength ◽

Mechanical Processing ◽

Ray Method ◽

X Ray ◽

Transmission Electron ◽

Water Quench ◽

Alpha Beta

The mechanical properties of three titanium alloys (Ti-7Mo-3Al, Ti-7Mo- 3Cu and Ti-7Mo-3Ta) were evaluated as function of: 1) Solutionizing in the beta field and aging, 2) Thermal Mechanical Processing in the beta field and aging, 3) Solutionizing in the alpha + beta field and aging. The samples were isothermally aged in the temperature range 300° to 700*C for 4 to 24 hours, followed by a water quench. Transmission electron microscopy and X-ray method were used to identify the phase formed. All three alloys solutionized at 1050°C (beta field) transformed to martensitic alpha (alpha prime) upon being water quenched. Despite this heavily strained alpha prime, which is characterized by microtwins the tensile strength of the as-quenched alloys is relatively low and the elongation is as high as 30%.

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Two- or three-way observations of the identical cell elements within the same sections by LM, TEM and/or SEM

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100081279 ◽

1978 ◽

Vol 36 (2) ◽

pp. 82-83 ◽

Cited By ~ 1

Author(s):

Nakazo Watari ◽

Yasuaki Hotta ◽

Yoshio Mabuchi

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

Transmission Electron Microscopy ◽

Fine Structure ◽

Light Microscopy ◽

Thin Sections ◽

Transmission Electron ◽

Identical Cell ◽

Electron Microscopes ◽

Scanning Electron

It is very useful if we can observe the identical cell elements within the same sections by light microscopy (LM), transmission electron microscopy (TEM) and/or scanning electron microscopy (SEM) sequentially, because, the cell fine structure can not be indicated by LM, while the color is; on the other hand, the cell fine structure can be very easily observed by EM, although its color properties may not. However, there is one problem in that LM requires thick sections of over 1 μm, while EM needs very thin sections of under 100 nm. Recently, we have developed a new method to observe the same cell elements within the same plastic sections using both light and transmission (conventional or high-voltage) electron microscopes.In this paper, we have developed two new observation methods for the identical cell elements within the same sections, both plastic-embedded and paraffin-embedded, using light microscopy, transmission electron microscopy and/or scanning electron microscopy (Fig. 1).

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Comparative Microstructures of Ion Milled and Electrochemically Thinned Composite Materials

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100052742 ◽

1974 ◽

Vol 32 ◽

pp. 546-547

Author(s):

R.R. Russell

Keyword(s):

Electron Microscopy ◽

Transmission Electron Microscopy ◽

Composite Materials ◽

Great Difficulty ◽

Ion Milling ◽

Transmission Electron ◽

Ion Damage ◽

Intermetallic Composite

Transmission electron microscopy of metallic/intermetallic composite materials is most challenging since the microscopist typically has great difficulty preparing specimens with uniform electron thin areas in adjacent phases. The application of ion milling for thinning foils from such materials has been quite effective. Although composite specimens prepared by ion milling have yielded much microstructural information, this technique has some inherent drawbacks such as the possible generation of ion damage near sample surfaces.

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Maytansine-Induced Mitotic Arrest in Human Lymphoblasts

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100079747 ◽

1977 ◽

Vol 35 ◽

pp. 460-461

Author(s):

Tai-Te Chao ◽

John Sullivan ◽

Awtar Krishan

Keyword(s):

Electron Microscopy ◽

Cell Cycle ◽

Transmission Electron Microscopy ◽

Tubulin Polymerization ◽

Vinca Alkaloids ◽

Antimitotic Activity ◽

Transmission Electron ◽

Flow Microfluorometry ◽

Brain Tubulin

Maytansine, a novel ansa macrolide (1), has potent anti-tumor and antimitotic activity (2, 3). It blocks cell cycle traverse in mitosis with resultant accumulation of metaphase cells (4). Inhibition of brain tubulin polymerization in vitro by maytansine has also been reported (3). The C-mitotic effect of this drug is similar to that of the well known Vinca- alkaloids, vinblastine and vincristine. This study was carried out to examine the effects of maytansine on the cell cycle traverse and the fine struc- I ture of human lymphoblasts.Log-phase cultures of CCRF-CEM human lymphoblasts were exposed to maytansine concentrations from 10-6 M to 10-10 M for 18 hrs. Aliquots of cells were removed for cell cycle analysis by flow microfluorometry (FMF) (5) and also processed for transmission electron microscopy (TEM). FMF analysis of cells treated with 10-8 M maytansine showed a reduction in the number of G1 cells and a corresponding build-up of cells with G2/M DNA content.

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