The Impact of EGCG and RG108 on SOCS1 Promoter DNA Methylation and Expression in U937 Leukemia Cells

Background:The available evidence has increasingly demonstrated that a combination of genetic and epigenetic factors, such as DNA methylation, could be considered as causing leukemia. Epigenetic changes and methylation of the suppressor of the cytokine signaling 1 promoter (SOCS1) CpG region silence SOCS1 expression in cancer. In the current study, we evaluated the impact of epigallocatechin gallate (EGCG) and RG108 on SOCS1 promoter methylation and expression in U937 cells.Methods:In the current study, U937 leukemic cells were treated with EGCG and RG108 for 12, 24, 48, and 72 h and SOCS1 promoter methylation and its expression were measured by methylation-specific PCR (MSP) and quantitative real-time PCR, respectively.Results:The outcomes indicated that the SOCS1 promoter is methylated in U937 cells, and treatment of these cells with either EGCG or RG108 reduced its methylation. Moreover, we observed that SOCS1 expression was significantly upregulated in a time-dependent manner by both EGCG and RG108 in U937 cells compared with control cells. In the RG108-treated group at 12, 24, 48, and 72 h, SOCS1 expression was upregulated by 1, 4.2, 16.6, and 32.6 -fold respectively, and in the EGCG-treated group, by 0.5, 3.2, 10.8, and 22.3 -fold, respectively. Conclusion:Treatment with either EGCG or RG108 reduced SOCS1 promoter methylation and increased SOCS1 expression in U937 cells in a time-dependent manner, which may play a role in leukemia therapy.Key Words: DNA Methylation, EGCG, Leukemia, RG108, SOCS1     

Hypoglycemic and Hypolipidemic Effects of Leucine,Zinc, and Chromium,Alone and in Combination,in Rats with Type 2 Diabetes

The main objective was to determine the elemental profile of the lung lining fluid of rats which are used as model animals in various experiments. Lung lining fluid elemental constitution obtained after bronchoalveolar lavage fluid (BALF) was analyzed by inductively coupled plasma mass spectrometry (ICP-MS) to determine the biological trace elements along with calcium and magnesium. BALF was collected from healthy rats using a tracheal cannula. However, cells in BALF were counted to monitor any underlying inflammatory lung condition. Cell free BALF samples were processed and analyzed for the elements including magnesium (Mg), calcium (Ca), chromium (Cr), manganese (Mn), iron (Fe), nickel (Ni), copper (Cu), zinc (Zn), selenium (Se), bromine (Br), and iodine (I). In view of this, calcium concentration was the highest (6318.08 ± 3094.3 μg/L) and copper concentration was the lowest (0.89 ± 0.21 μg/L). The detected elements, from high to low concentration, include Ca > Mg > Fe > Br > I > Cr > Ni > Zn > Mn > Se > Cu. Pearson’s correlation analysis revealed no significant correlation between cell count and concentration of any of the element detected in BALF. Correlation analysis also revealed significant positive correlation among Fe, I, Cr, Ni, and Mn. Ca was found to be correlated negatively with Cu and positively with Se. Br and Mg found to be positively correlated with each other. Zn remained the only element that was not found to be correlated with any of the elements in the rat BALF.     

Spatiotemporal Model of Barley and Cereal Yellow Dwarf Virus Transmission Dynamics with Seasonality and Plant Competition

Many generalist pathogens are influenced by the spatial distributions and relative abundances of susceptible host species. The spatial structure of host populations can influence patterns of infection incidence (or disease outbreaks), and the effects of a generalist pathogen on host community dynamics in a spatially heterogeneous community may differ from predictions derived via simple models. In this paper, we model the transmission of a generalist pathogen within a patch framework that incorporates the movement of vectors between discrete host patches to investigate the effects of local host community composition and vector movement rates on disease dynamics.     

Characterization of Lung Fibroblasts More than Two Decades after Mustard Gas Exposure

Purpose

In patients with short-term exposure to the sulfur mustard gas, the delayed cellular effects on lungs have not been well understood yet. The lung pathology shows a dominant feature consistent with obliterative bronchiolitis, in which fibroblasts play a central role. This study aims to characterize alterations to lung fibroblasts, at the cellular level, in patients with delayed respiratory complications after short-term exposure to the sulfur mustard gas.

Methods

Fibroblasts were isolated from the transbronchial biopsies of patients with documented history of exposure to single high-dose sulfur mustard during 1985–7 and compared with the fibroblasts of control subjects.

Results

Compared with controls, patients’ fibroblasts were thinner and shorter, and showed a higher population doubling level, migration capacity and number of filopodia. Sulfur mustard decreased the in vitro viability of fibroblasts and increased their sensitivity to induction of apoptosis, but did not change the rate of spontaneous apoptosis. In addition, higher expression of alpha smooth muscle actin showed that the lung''s microenvironment in these patients is permissive for myofibroblastic differentiation.

Conclusions

These findings suggest that in patients under the study, the delayed pulmonary complications of sulfur mustard should be considered as a unique pathology, which might need a specific management by manipulation of cellular components.     

Expression and Functional Characterization of <Emphasis Type="Italic">Pseudomonas aeruginosa</Emphasis> Recombinant <Emphasis Type="SmallCaps">l</Emphasis>.Asparaginase

Recombinant _l.asparaginase, L.ASNase, from Pseudomonas aeruginosa was purified using nickel affinity chromatography. The affinity purified L.ASNase exhibited a protein band with a molecular weight of 72.4 kDa on a native polyacrylamide gel and 36.276 kDa using SDS–PAGE. The activity of the purified L.ASNase was enhanced by Mg²⁺ and inhibited by Zn²⁺ at a concentration of 5 mM. The specificity of the recombinant L.ASNase towards different substrates was examined, and it was found that the enzyme showed the highest activity towards l.asparagine. Moreover, the enzyme showed lower activity towards other substrates such as _L.glutamine, urea and acrylamide. The in vitro hemolysis assay revealed that the purified L.ASNase did not show hemolysis effect on blood erythrocytes. Serum and trypsin half-life of L.ASNase suggested that the recombinant L.ASNase retained 50% of its initial activity after 90 and 60 min incubation period in serum and trypsin separately.     

The Human Cathelicidin LL-37, a Defensive Peptide Against Rotavirus Infection

International Journal of Peptide Research and Therapeutics - LL-37 is a 37 amino acid long cationic peptide belonging to the cathelicidin family of antimicrobial peptides. Limited investigations...     

Dissolved oxygen concentration regulates human hepatic organoid formation from pluripotent stem cells in a fully controlled bioreactor

Developing technologies for scalable production of human organoids has gained increased attention for “organoid medicine” and drug discovery. We developed a scalable and integrated differentiation process for generation of hepatic organoid from human pluripotent stem cells (hPSCs) in a fully controlled stirred tank bioreactor with 150 ml working volume by application of physiological oxygen concentrations in different liver tissue zones. We found that the 20–40% dissolved oxygen concentration [DO] (corresponded to 30–60 mmHg pO₂ within the liver tissue) significantly influences the process outcome via regulating the differentiation fate of hPSC aggregates by enhancing mesoderm induction. Regulation of the [DO] at 30% DO resulted in efficient generation of human fetal-like hepatic organoids that had a uniform size distribution and were comprised of red blood cells and functional hepatocytes, which exhibited improved liver-specific marker gene expressions, key liver metabolic functions, and, more important, higher inducible cytochrome P450 activity compared to the other trials. These hepatic organoids were successfully engrafted in an acute liver injury mouse model and produced albumin after implantation. These results demonstrated the significant impact of the dissolved oxygen concentration on hPSC hepatic differentiation fate and differentiation efficacy that should be considered ascritical translational aspect of established scalable liver organoid generation protocols for potential clinical and drug discovery applications.