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Analytical characterization of aberrant trisulfide bond formation in therapeutic proteins and their impact on product quality
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Aberrant miR-21 and miR-200b expression and its pro-fibrotic potential in hypertrophic scars
The post-traumatic hypertrophic scar (HS) is a fibrotic disease with excessive extracellular matrix (ECM) production by fibroblasts in response to tissue injury. Although dysregulation of miRNAs is known to be involved in a variety of pathophysiologic processes, the role of miRNA in hypertrophic scar formation is unclear. Abnormal expression of miRNA in fibrosis has been investigated in several studies. The transforming growth factor β1 (TGF-β1) promotes fibroblasts proliferation, the synthesis of collagen and other extracellular matrix, and ultimately leads to the formation of the HS by inducing excessive deposition of ECM. We identified two miRNAs whose expression was correlated with fibrotic diseases: miR-21 and miR-200b. This study further confirmed that after stimulation with TGF-β1, the expression of miR-21 was increased, whereas the mRNA level of SMAD7 was decreased in fibroblasts. TGF-β1 reduced the expression of miR-200b, while it augmented that of Zinc finger E-box-binding homeobox 1(Zeb1). Our experiments demonstrated that the expression of miR-21 and miR-200b are related to a disorder, and the TGF-β/miR-21/Smad7 and TGF-β/miR200b/Zeb1 pathways might participate in the pathogenesis of HS. Thus, a novel, beyond the traditional methods, approach for HS treatment via miRNA therapeutics could have been provided. - Highlights: • HS tissue had increased expression of miR-21 and decreased expression of Smad7, lower expression of miR-200b and higher expression of Zeb1. • TGF-β1 downregulated Smad7, which was correlated with the upregulation of miR-21. • TGF-β1 upregulated Zeb1, which was correlated with the downregulation of miR-200b. • miR-200b decreased the expression of Col1A1,Col3A1, Fn, and α-SMA, as well as that of the target Zeb1. • The miR-21 inhibitor decreased expression of Col1A1, Col3A1, Fn, and α-SMA and increased the expression of Smad7.
Inhibition of p300 histone acetyltransferase activity in palate mesenchyme cells attenuates Wnt signaling via aberrant E-cadherin expression
p300 is a multifunctional transcriptional coactivator that interacts with numerous transcription factors and exhibits protein/histone acetyltransferase activity. Loss of p300 function in humans and in mice leads to craniofacial defects. In this study, we demonstrated that inhibition of p300 histone acetyltransferase activity with the compound, C646, altered the expression of several genes, including Cdh1 (E-cadherin) in mouse maxillary mesenchyme cells, which are the cells that give rise to the secondary palate. The increased expression of plasma membrane-bound E-cadherin was associated with reduced cytosolic β-catenin, that led to attenuated signaling through the canonical Wnt pathway. Furthermore, C646 reduced both cell proliferation and the migratory ability of these cells. These results suggest that p300 histone acetyltransferase activity is critical for Wnt-dependent palate mesenchymal cell proliferation and migration, both processes that play a significant role in morphogenesis of the palate. - Highlights: • Inhibition of p300 HAT in cultured palate cells increased E-cadherin expression. • Inhibition of p300 HAT perturbed canonical Wnt signaling in cultured palate cells. • Blocking p300 HAT in palate cells altered rates of apoptosis, proliferation, and migration.
Patients with idiopathic endplate inflammation displayed aberrant Th17 responses resulting in proinflammatory monocyte activation
Endplate inflammation remains a difficult task to diagnose and treat, partly due to the absence of in-depth understanding of the cellular and molecular factors driving this condition. In the current study, we investigated the circulating immune cells in patients with idiopathic endplate inflammation. Compared to healthy controls, the patients with endplate inflammation presented a significant upregulation of Th17 cells, characterized by higher frequencies of circulating IL-17{sup +}CD4{sup +} T cells examined directly ex vivo and after PMA and ionomycin (PMA/I) stimulation. The frequency of Th17 cells in patients was not correlated with patient age, sex, or smoking status, but was significantly correlated with patient BMI. The total CD4{sup +} T cells from patients with end plate inflammation also presented significantly higher levels of IL-17 secretion directly ex vivo and after PMA/I stimulation. The IL-17 secretion was primarily mediated by CCR4{sup +}CCR6{sup +} CD4{sup +} T cells, followed by CCR4{sup -}CCR6{sup +} CD4{sup +} T cells and was nearly absent in CCR4{sup -}CCR6{sup -} CD4{sup +} T cells. Monocytes incubated with CCR4{sup +}CCR6{sup +} CD4{sup +} T cells presented significantly higher MHC class II expression, as well as higher CD80 and CD86 expression. The secretion of IL-6 and TNF was significantly higher in cell cultures containing CCR4{sup +}CCR6{sup +} CD4{sup +} T cells than in cell cultures containing CCR4{sup -}CCR6{sup -} CD4{sup +} T cells. These effects were reduced when the IL-17A cytokine was neutralized. Together, we identified a systemic upregulation of Th17 responses that could contribute to proinflammatory monocyte activation in patients with endplate inflammation.
Aberration corrected STEM and High Resolution EELS study Investigating Magnesium Intercalation in Vanadium Pentoxide Cathode
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Three-dimensional location of a single dopant with atomic precision by aberration-corrected scanning transmission electron microscopy
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Aberrant electronic and structural alterations in pressure tuned perovskite NaOsO 3
The perovskite NaOsO 3 has a metal–insulator transition at temperature 410 K, which is delicate, intriguing, and provokes a lot of debate on its nature. Our combined electrical resistance, Raman, and synchrotron x-ray diffraction experiments show that the insulating ground state in this osmate endures under high pressure up to at least 35 GPa. In this pressure range, compression reveals hidden hysteretic resistance properties with a transient metallic state near 200 K, manifested three electronic character anomalies (at 1.7, 9.0, and 25.5 GPa), and a structural transition to the singular polar phase (at ~18 GPa). We distinguish NaOsO 3 from the regular crystallographic behavior of perovskites, though the electrical specificities resemble iridates and nickelates. The theoretical first-principle band structure and lattice dynamics calculations demonstrate that the magnetically itinerant Lifshitz-type mechanism with spin–orbit and spin–phonon interactions is responsible for these pressure-induced changes. Our findings provide another new playground for the emergence of new states in 5d materials by using high-pressure methods.
Metabolomics and the pig model reveal aberrant cardiac energy metabolism in metabolic syndrome
Abstract Although metabolic syndrome (MS) is a significant risk of cardiovascular disease (CVD), the cardiac response (MR) to MS remains unclear due to traditional MS models’ narrow scope around a limited number of cell-cycle regulation biomarkers and drawbacks of limited human tissue samples. To date, we developed the most comprehensive platform studying MR to MS in a pig model tightly related to human MS criteria. By incorporating comparative metabolomic, transcriptomic, functional analyses, and unsupervised machine learning (UML), we can discover unknown metabolic pathways connections and links on numerous biomarkers across the MS-associated issues in the heart. For the first time, we show severely diminished availability of glycolytic and citric acid cycle (CAC) pathways metabolites, altered expression, GlcNAcylation, and activity of involved enzymes. A notable exception, however, is the excessive succinate accumulation despite reduced succinate dehydrogenase complex iron-sulfur subunit b (SDHB) expression and decreased content of precursor metabolites. Finally, the expression of metabolites and enzymes from the GABA-glutamate, GABA-putrescine, and the glyoxylate pathways significantly increase, suggesting an alternative cardiac means to replenish succinate and malate in MS. Our platform discovers potential therapeutic targets for MS-associated CVD within pathways that were previously unknown to corelate with the disease.
Revisiting the “In-clustering” question in InGaN through the use of aberration-corrected electron microscopy below the knock-on threshold
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Atomically resolved structure of ligand-protected Au{sub 9} clusters on TiO{sub 2} nanosheets using aberration-corrected STEM
Triphenylphosphine ligand-protected Au{sub 9} clusters deposited onto titania nanosheets show three different atomic configurations as observed by scanning transmission electron microscopy. The configurations observed are a 3-dimensional structure, corresponding to the previously proposed Au{sub 9} core of the clusters, and two pseudo-2-dimensional (pseudo-2D) structures, newly found by this work. With the help of density functional theory (DFT) calculations, the observed pseudo-2D structures are attributed to the low energy, de-ligated structures formed through interaction with the substrate. The combination of scanning transmission electron microscopy with DFT calculations thus allows identifying whether or not the deposited Au{sub 9} clusters have been de-ligated in the deposition process.
Static characterization of a highly optimized streak tube design incorporating a steering slot anode and an aberration-corrected Einzel lens
The BHx streak tube, under development at the Laboratory for Laser Energetics, incorporates a series of novel electron-optics elements to enable high fidelity measurements for high-energy-density physics experiments. The system is engineered to support a 25-mm active photocathode region compatible with sub-picosecond temporal resolution and with 70% internal photoelectron throughput. It exhibits negligible geometric distortion on a flat output screen, making it well suited for variety of measurements, such as ultrafast x-ray spectroscopy. Here, this paper presents characterization data from a prototype unit tested with an ultraviolet laser in a static deflection (non-swept) mode and shows good agreement with the predictions from numerical modeling, including focusing performance and geometric distortion measurements. Key design elements have been demonstrated and de-risked, laying the foundation for dynamic deflection testing. The anticipated improvements in data fidelity are expected to impact the fields as diverse as inertial confinement fusion, laboratory astrophysics, and materials science.
Limits of Three-Dimensional Resolution and Dose for Aberration-Corrected Electron Tomography
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Visualization of defects in single-crystal and thin-film PdCoO 2 using aberration-corrected scanning transmission electron microscopy
Single-crystal delafossite PdCoO 2 is known to have an extremely low intrinsic impurity concentration of ~0.001%, demonstrating extraordinarily high conductivity with a mean free path of ~20 μm at low temperatures. However, when grown as thin films, the resistivity at room temperature increases by a factor of 3–80 times, depending on the film thickness. Using scanning transmission electron microscopy, we identify different classes of defects for the single crystal vs epitaxial thin film. The dominant defect for single-crystal PdCoO 2 is found to be ribbonlike defects. For the thin films, we identify different types of defects arising in epitaxial thin films mainly due to substrate termination that disrupt the lateral connectivity of the conducting planes. Further, our results are consistent with the high conductivity of single crystals and increased electrical resistivity of the thin films compared to that of single crystals, suggesting that selecting a proper substrate, improving surface quality, and reducing the step density are the keys to enhance the film quality for utilizing PdCoO 2 as a platform for future applications.