Age-Dependent Variation in Glycosylation Features of Alpha-2-Macroglobulin Abstract Alpha-2-macroglobulin (A2M) is a glycosylated broad spectrum inhibitor of numerous proteases, including those involved in blood coagulation. Glycosylation characteristics can affect protein structure and function. This study compares glycosylation characteristics of A2M in newborn umbilical cord (NUCP) and adult pooled plasmas. Peptide N-Glycosidase F treatment was used to evaluate the total N-glycan content of the molecules. Neuraminidase treatment, and affinity for Ricinus Communis Agglutinin I were used to examine terminal sialic acid and galactose content, respectively. Two-dimensional (2D) electrophoresis was used to determine charge-related isoform profiles and fluorophore-assisted carbohydrate electrophoresis (FACE) was used to characterize N-glycan profiles. Results revealed no difference in total N-glycan mass, however, a statistically significant difference was shown in the change in charge associated with sialic acid loss in the NUCP A2M population. 2D electrophoresis indicated a lower pI range for NUCP A2M isoforms. In addition, NUCP A2M displayed a trend toward higher terminal galactose quantities than adult A2M. FACE revealed an increased abundance of more branched, higher molecular weight glycans in NUCP A2M. These differences in glycan branching and charged residues may impact A2M receptor-based clearance and thus could be responsible for the increased A2M concentration seen in NUCP, and newborns.

Correction to: Heat Shock Protein 90 Stimulates Rat Mesenchymal Stem Cell Migration via PI3K/Akt and ERK1/2 Pathways An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Retraction Note to: miR-200 Regulates Epithelial–Mesenchymal Transition in Anaplastic Thyroid Cancer via EGF/EGFR Signaling An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Correction to: Effects of AMPK on Apoptosis and Energy Metabolism of Gastric Smooth Muscle Cells in Rats with Diabetic Gastroparesis An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Capsaicin And Genistein Override The Action Of Obestatin To Decrease Lipid Accumulation In 3T3-L1 Cells Abstract Satiety peptides convey information about short-term energy reserves in the gut to the hypothalamus and aid in regulation of appetite and food intake. Obestatin is one such gastro peptide that has been shown to upregulate glycerolipid metabolism and PPARγ signalling. Obestatin brings about moderate reduction in circulating and stored triglyceride levels and reduction in gain in body weight in mice. We wanted to test whether obestatin could be further potentiated by co-administration with nutraceuticals genistein and capsaicin that are well known to reduce triglyceride levels. Hence, we chose to administer the compounds individually and pair-wise with obestatin in 3T3-L1 cells at concentrations of 200 nM obestatin, 10 µM capsaicin and 100 µM genistein. When treated along with induction of differentiation, both capsaicin and genistein in combination with obestatin reduced triglyceride levels in 3T3-L1 cells by 25 and 20%, respectively, when accessed on day 14 after induction. The combined administrations were dominated by the effect of the nutraceuticals and showed the same effect as of capsaicin or genistein. Upregulation of Fatty acid synthase (Fasn) and Adipose triglyceride lipase (Atgl/Pnpla2) by obestatin were reversed by both capsaicin and genistein. However, their ability to upregulate Peroxisome proliferation activating receptor gamma (Pparγ), Hormone sensitive lipase (Hsl), Lipoprotein lipase (Lpl) were retained while upregulation of Uncoupling protein 1 (Ucp1) by capsaicin was unchanged upon co-administration. Over expression of the lipases and UCP1 in case of capsaicin could be resulting in net lowering of lipid accumulation in the cells.

Selective Covalent Inhibition of “Allosteric Cys121” Distort the Binding of PTP1B Enzyme: A Novel Therapeutic Approach for Cancer Treatment Abstract Covalent inhibition targeting noncatalytic residues is rapidly gaining attention in drug discovery. Protein tyrosine phosphatases 1B (PTP1B) is an attractive target for therapeutic interventions in cancer and other diseases. Two binding sites of PTP1B enzyme were identified, catalytic and allosteric. The catalytic site is deep and narrow which protects the active site amino acid residue Cys215 from covalent inhibition, whereas the allosteric site is more hydrophobic and less conserved with Cys121 residue, to which covalent inhibitors can bind. A recent experimental report highlighted that a highly selective inhibitor, 73U, was found to bind covalently in the allosteric region of PTP1B enzyme. Using a robust covalent simulations protocol which was developed in-house, we explore the origin and impact of covalent inhibition upon inhibitor binding to allosteric site. For this, covalently bound and apo enzymes were investigated. Results revealed that allosteric covalent inhibition has ensued in a significant disturbance in the overall network of interaction between Cys121 and other nearby residues, more specifically Tyr124 and His214. The covalent inhibition also exhibited better protein stability as evident from positive correlation between residues in the allosteric site and multiple van der Waal, hydrogen bond and ionic interactions. Surface analysis revealed an increase in the accessible surface area in order to facilitate for the covalent inhibitor to sink in. These findings indicate that exploring allosteric covalent mechanism of PTP1B enzyme offers an opportunity to develop novel PTP1B covalent inhibitors with high potency and selectivity for cancer and other diseases.

Merging Preclinical EPR Tomography with other Imaging Techniques Abstract This paper presents a survey of electron paramagnetic resonance (EPR) image registration. Image registration is the process of overlaying images (two or more) of the same scene taken at different times, from different viewpoints and/or different techniques. EPR-imaging (EPRI) techniques belong to the functional-imaging modalities and therefore suffer from a lack of anatomical reference which is mandatory in preclinical imaging. For this reason, it is necessary to merging EPR images with other modalities which allow for obtaining anatomy images. Methodological analysis and review of the literature were done, providing a summary for developing a good foundation for research study in this field which is crucial in understanding the existing levels of knowledge. Out of these considerations, the aim of this paper is to enhance the scientific community’s understanding of the current status of research in EPR preclinical image registration and also communicate to them the contribution of this research in the field of image processing.

The Ribosomal Protein RPLP0 Mediates PLAAT4-induced Cell Cycle Arrest and Cell Apoptosis Abstract Phospholipase A and acyltransferase 4 (PLAAT4) is a member of the HREV107 tumor suppressor gene family. The expression of PLAAT4 has been shown to induce cell death; however, the underlying mechanism remains unknown. Here, we found that RPLP0, a ribosomal protein, can interact with PLAAT4, as determined by yeast two-hybrid screening, coimmunoprecipitation, and colocalization. The level of RPLP0 was suppressed in HtTA cervical cancer cells expressing PLAAT4. In PLAAT4-expressing or RPLP0-silenced cells, decreased cell viability and cell proliferation combined with increased cell death were observed. Furthermore, the levels of cell cycle-associated proteins and anti-apoptotic proteins decreased in PLAAT4-expressing or RPLP0-silenced cells. Similar patterns of cell viability and expression levels of cell-cycle-associated proteins and apoptosis-related proteins were observed in PLAAT4-expressing and RPLP0-knockdown cells, indicating that RPLP0 deficiency might be involved in PLAAT4-mediated growth inhibition and cellular apoptosis.

Attenuation of cardiac ischemia-reperfusion injury by sodium thiosulfate is partially dependent on the effect of cystathione beta synthase in the myocardium Abstract Our early studies have shown that sodium thiosulfate (STS) treatment attenuated the ischemia-reperfusion (IR)-induced injury in an isolated rat heart model by decreasing apoptosis, oxidative stress, and preserving mitochondrial function. Hydrogen sulfide, the precursor molecule is reported to have similar efficacy. This study aims to investigate the role of endogenous hydrogen sulfide in STS-mediated cardioprotection against IR in an isolated rat heart model. d, l-propargylglycine (PAG), an inhibitor of cystathionine γ-lyase was used as endogenous H2S blocker. In addition, we used the hypoxia-reoxygenation (HR) model to study the impact of STS in cardiomyocytes (H9C2) and fibroblast (3T3) cells. STS treatment to animal and cells prior to IR or HR decreased cell injury. The sensitivity of H9C2 and 3T3 cells towards HR (6 h hypoxia followed by 12 h reoxygenation) challenge varies, where, 3T3 cells exhibited higher cell death (54%). Cells treated with PAG prior to STS abrogate the protective effect in 3T3 (cell viability 61%) but not in H9C2 (cell viability 82%). Further evaluation in rat heart model showed partial recovery (46% RPP) of heart from those hearts pretreated with PAG prior to STS condition. In conclusion, we demonstrated that STS-mediated cardioprotection to IR-challenged rat heart is not fully dependent on endogenous H2S level and this dependency may be linked to higher fibroblast content in rat heart.

Externally Controlled Cellular Transport of Magnetic Iron Oxide Particles with Polysaccharide Surface Coatings Abstract Recently, due to their promising applications in biomedicine, magnetic iron oxide nanoparticles (MPs) have become one of the research hotspots in the nanomedicine field. Since various synthetic modifications have been widely applied to these nanoparticles for better targeting behaviors, it is meaningful to apply the optimal magnetic field condition for each case. This will enable creating a safe and efficient drug targeting using different types of MPs. In the present study, we aimed to find out any changes of transepithelial transport of polysaccharide-coated MPs by applying the continuous or the pulsatile magnetic field condition. Our results with heparin-functionalized MPs indicate that the particle concentrations and the external magnetic field could influence the transepithelial permeability of the particles. In the presence of a continuously applied magnetic density, heparin-MPs at high concentrations, by forming magnetically-induced aggregation of particles over the cell surface layer, showed a lower cellular transport than those at low concentrations. Furthermore, the results from the quantitative chemical assays and imaging analyses showed that transepithelial transport of heparin-MPs (negatively charged) under the pulsatile magnetic field was higher than that under the continuous magnetic field (CP), whereas the starch-MPs (neutrally charged) showed a small difference in transepithelial transport or cell retention between pulsatile vs. continuous magnetic field conditions. Taken together, our results suggest that the external magnetic field should be differentially applied to control the cellular drug transport depending on the physicochemical properties of the surface chemistry of magnetic particles.