Expression of plasma membrane proton-ATPase gene in salt-tolerant yeast Zygosaccharomyces rouxii is induced by sodium chloride

Abstract The amounts of mRNA and protein of plasma membrane proton-ATPase were measured in the salt-tolerant yeast Zygosaccharomyces rouxii by Northern and Western blot analyses. Although their amounts were independent of growth phase, their synthesis were induced when yeast cells were grown in the presence of NaCl or were subjected to NaCl shock. This finding was consistent with our previous result that plasma membrane proton-ATPase activity was elevated in Z. rouxii cells grown in medium containing high concentrations of NaCl.     

Hydrogen bonds in Zif268 proteins – a theoretical perspective

The aim of the work was to elucidate the presence of different hydrogen bond (H-bond) in five Zif268 proteins (1A1F, 1A1G, 1A1H, 1A1I and 1A1K). For this purpose, we have performed the QM/MM and molecular dynamics (MD) studies, the results of which reveal that H-bonds depend on the amino acid sequence and orientation of the H-bond donor atoms. Further, high specificity of Arg and Asn is observed for guanine and adenine, respectively. Furthermore, both conventional and non-conventional hydrogen bond also exists in the proteins, among them N–H?O H-bonds are the strongest. Besides, the non-conventional bonds play a role in the protein folding and DNA stacking. From the QSAR properties, amino acids such as asparagine and aspartic acids are the major reactive sites in the Zif268 protein. The electron affinities of Zif268 proteins are high, so the charge transfer occurs from the DNA to the protein molecules. NBO analysis indicates the majority of charge transfer occurs from DNA to the corresponding anti-bonding orbital of the peptides. Root mean square deviation and R_g (radius of gyration) show that 1A1F is more compact and in native state during MD simulation. The minimum R_g leads to the large number of hydrogen bonds formation in 1A1F. Higher solvent accessible surface area in 1A1I indicates that the cavity inside the protein is large.     

Cryopreservation of heat-shocked canine adipose-derived mesenchymal stromal cells with 10% dimethyl sulfoxide and 40% serum results in better viability,proliferation, anti-oxidation,and in-vitro differentiation

Cryopreserved canine adipose-derived mesenchymal stromal cells (Ad-MSCs) can be used instantly in dogs for clinical uses. However, cryopreservation results in a reduction of the cellular viability, proliferation, and anti-oxidation of post-thawed Ad-MSCs. Therefore, there is a need for in-vitro procedure to improve post-thawed Ad-MSCs’ viability, proliferation, anti-oxidation, and differentiation capacity. In this study, fresh-Ad-MSCs were activated with heat shock, hypoxia (5% O₂), or hypoxia (5% O₂) + heat shock treatments. The results showed that compared to the other treatments, heat shock significantly improved the proliferation rate, anti-oxidation, heat shock proteins and growth factors expressions of canine-fresh-Ad-MSCs. Consequently, fresh-Ad-MSCs were heat-shocked and then cryopreserved with different combinations of dimethyl sulfoxide (Me₂SO) and fetal bovine serum (FBS) to determine the combination that could effectively preserve the cellular viability, proliferation, anti-oxidation and differentiation capacity of Ad-MSCs after cryopreservation. We found that C-HST-Ad-MSCs cryopreserved with 10% Me₂SO + 40% FBS presented significantly (p < 0.05) improved cellular viability, proliferation rate, anti-oxidant capacity, and differentiation potential as compared to C-HST-Ad-MSCs cryopreserved with 1% Me₂SO + 10% FBS or 1% Me₂SO alone or control. We concluded, heat shock treatment is much better to enhance the characteristics of fresh-Ad-MSCs than other treatments, moreover, C-HST-Ad-MSCs in 10% Me₂SO + 40% FBS showed better results compared to other cryopreserved groups. However, future work is required to optimize the expression of heat shock proteins, which would further improve the characteristics of fresh- and cryopreserved-HST-Ad-MSCs and reduce the dependency on Me₂SO and FBS.     

A second Warburg-like effect in cancer metabolism: The metabolic shift of glutamine-derived nitrogen

Carbon and nitrogen are essential elements for life. Glucose as a carbon source and glutamine as a nitrogen source are important nutrients for cell proliferation. About 100 years ago, it was discovered that cancer cells that have acquired unlimited proliferative capacity and undergone malignant evolution in their host manifest a cancer-specific remodeling of glucose metabolism (the Warburg effect). Only recently, however, was it shown that the metabolism of glutamine-derived nitrogen is substantially shifted from glutaminolysis to nucleotide biosynthesis during malignant progression of cancer—which might be referred to as a “second” Warburg effect. In this review, address the mechanism and relevance of this metabolic shift of glutamine-derived nitrogen in human cancer. We also examine the clinical potential of anticancer therapies that modulate the metabolic pathways of glutamine-derived nitrogen. This shift may be as important as the shift in carbon metabolism, which has long been known as the Warburg effect.