Summary Saccharomyces cerevisiae is traditionally used for alcoholic beverage and bioethanol production; however, its performance during fermentation is compromised by the impact of ethanol accumulation on cell vitality. This article reviews studies into the molecular basis of the ethanol stress response and ethanol tolerance of S. cerevisiae; such knowledge can facilitate the development of genetic engineering strategies for improving cell performance during ethanol stress. Previous studies have used a variety of strains and conditions, which is problematic, because the impact of ethanol stress on gene expression is influenced by the environment. There is however some commonality in Gene Ontology categories affected by ethanol assault that suggests that the ethanol stress response of S. cerevisiae is compromised by constraints on energy production, leading to increased expression of genes associated with glycolysis and mitochondrial function, and decreased gene expression in energy‐demanding growth‐related processes. Studies using genome‐wide screens suggest that the maintenance of vacuole function is important for ethanol tolerance, possibly because of the roles of this organelle in protein turnover and maintaining ion homoeostasis. Accumulation of Asr1 and Rat8 in the nucleus specifically during ethanol stress suggests S. cerevisiae has a specific response to ethanol stress although this supposition remains controversial.

No abstract

Formononetin, an isoflavone, is extracted from various medicinal plants and herbs, including the red clover (Trifolium pratense) and Chinese medicinal plant Astragalus membranaceus. Formononetin’s antioxidant and neuroprotective effects underscore its therapeutic use against Alzheimer’s disease. Formononetin has been under intense investigation for the past decade as strong evidence on promoting apoptosis and against proliferation suggests for its use as an anticancer agent against diverse cancers. These anticancer properties are observed in multiple cancer cell models, including breast, colorectal, and prostate cancer. Formononetin also attenuates metastasis and tumor growth in various in vivo studies. The beneficial effects exuded by formononetin can be attributed to its antiproliferative and cell cycle arrest inducing properties. Formononetin regulates various transcription factors and growth-factor-mediated oncogenic pathways, consequently alleviating the possible causes of chronic inflammation that are linked to cancer survival of neoplastic cells and their resistance against chemotherapy. As such, this review summarizes and critically analyzes current evidence on the potential of formononetin for therapy of various malignancies with special emphasis on molecular targets.

Saccharomyces spp. are widely used for ethanologenic fermentations, however yeast metabolic rate and viability decrease as ethanol accumulates during fermentation, compromising ethanol yield. Improving ethanol tolerance in yeast should, therefore, reduce the impact of ethanol toxicity on fermentation performance. The purpose of the current work was to generate and characterise ethanol-tolerant yeast mutants by subjecting mutagenised and non-mutagenised populations of Saccharomyces cerevisiae W303-1A to adaptive evolution using ethanol stress as a selection pressure. Mutants CM1 (chemically mutagenised) and SM1 (spontaneous) had increased acclimation and growth rates when cultivated in sub-lethal ethanol concentrations, and their survivability in lethal ethanol concentrations was considerably improved compared with the parent strain. The mutants utilised glucose at a higher rate than the parent in the presence of ethanol and an initial glucose concentration of 20 g l(-1). At a glucose concentration of 100 g l(-1), SM1 had the highest glucose utilisation rate in the presence or absence of ethanol. The mutants produced substantially more glycerol than the parent and, although acetate was only detectable in ethanol-stressed cultures, both mutants produced more acetate than the parent. It is suggested that the increased ethanol tolerance of the mutants is due to their elevated glycerol production rates and the potential of this to increase the ratio of oxidised and reduced forms of nicotinamide adenine dinucleotide (NAD(+)/NADH) in an ethanol-compromised cell, stimulating glycolytic activity.

Saccharomyces spp. are widely used for ethanol production; however, fermentation productivity is negatively affected by the impact of ethanol accumulation on yeast metabolic rate and viability. This study used microarray and statistical two-way ANOVA analysis to compare and evaluate gene expression profiles of two previously generated ethanol-tolerant mutants, CM1 and SM1, with their parent, Saccharomyces cerevisiae W303-1A, in the presence and absence of ethanol stress. Although sharing the same parentage, the mutants were created differently: SM1 by adaptive evolution involving long-term exposure to ethanol stress and CM1 using chemical mutagenesis followed by adaptive evolution-based screening. Compared to the parent, differences in the expression levels of genes associated with a number of gene ontology categories in the mutants suggest that their improved ethanol stress response is a consequence of increased mitochondrial and NADH oxidation activities, stimulating glycolysis and other energy-yielding pathways. This leads to increased activity of energy-demanding processes associated with the production of proteins and plasma membrane components, which are necessary for acclimation to ethanol stress. It is suggested that a key function of the ethanol stress response is restoration of the NAD(+)/NADH redox balance, which increases glyceraldehyde-3-phosphate dehydrogenase activity, and higher glycolytic flux in the ethanol-stressed cell. Both mutants achieved this by a constitutive increase in carbon flux in the glycerol pathway as a means of increasing NADH oxidation.

Trehalose is known to protect cells from various environmental assaults; however, its role in the ethanol tolerance of Saccharomyces cerevisiae remains controversial. Many previous studies report correlations between trehalose levels and ethanol tolerance across a variety of strains, yet variations in genetic background make it difficult to separate the impact of trehalose from other stress response factors. In the current study, investigations were conducted on the ethanol tolerance of S. cerevisiae BY4742 and BY4742 deletion strains, tsl1Delta and nth1Delta, across a range of ethanol concentrations. It was found that trehalose does play a role in ethanol tolerance at lethal ethanol concentrations, but not at sublethal ethanol concentrations; differences of 20-40% in the intracellular trehalose concentration did not provide any growth advantage for cells incubated in the presence of sublethal ethanol concentrations. It was speculated that the ethanol concentration-dependent nature of the trehalose effect supports a mechanism for trehalose in protecting cellular proteins from the damaging effects of ethanol.

Methamphetamine (METH, or ice) use is a global burden, which continues to pervade and plague contemporary society with estimates of up to 35 million users worldwide. METH is a psychotropic compound which acts on the central nervous system, and, in chronic doses, can induce psychotic behavior from its highly addictive nature. METH harbours the capacity to cause modulation of immune cells, enabling the drug to have lasting, long-term effects which may manifest into neuropsychiatric disorders, as well as leading to increased susceptibility to communicable diseases, such as HIV. In addition, changes to the cytokine balance have been associated with blood brain barrier compromise, resulting to alterations to brain plasticity, creating lasting neurotoxicity. Furthermore, immune-related signaling pathways are key to further evaluating how METH impacts the host immunity through these neurological and peripheral modifications. Layering this knowledge with current data on inflammatory responses can help facilitate a better understanding of how the host adaptive and innate immunity responds to METH, how this can activate premature-ageing processes and how METH exacerbates disturbances leading to non-communicable age-related diseases, including cardiovascular disease, stroke, depression and dementia.

Purpose. Oxaliplatin is a platinum-based chemotherapeutic agent demonstrating significant antitumor efficacy. Unlike conventional anticancer agents which are immunosuppressive, oxaliplatin has the capacity to stimulate immunological effects in response to the presentation of damage associated molecular patterns (DAMPs) elicited upon cell death. However, the effects of oxaliplatin treatment on systemic immune responses remain largely unknown. Aims of this study were to investigate the effects of oxaliplatin treatment on the proportions of (1) splenic T cells, B cells, macrophages, pro-/anti-inflammatory cytokines, gene expression of splenic cytokines, chemokines, and mediators; (2) double-positive and single-positive CD4+and CD8+T thymocytes; (3) bone-marrow hematopoietic stem and progenitor cells.Methods. Male BALB/c mice received intraperitoneal injections of oxaliplatin (3mg/kg/d) or sterile water tri-weekly for 2 weeks. Leukocyte populations within the spleen, thymus, and bone-marrow were assessed using flow cytometry. RT-PCR was performed to characterise changes in splenic inflammation-associated genes.Results. Oxaliplatin treatment reduced spleen size and cellularity (CD45+cells), increased the proportion of CD4+, CD8+, and Treg cells, and elevated TNF-αexpression. Oxaliplatin was selectively cytotoxic to B cells but had no effect on splenic macrophages. Oxaliplatin treatment altered the gene expression of several cytokines, chemokines, and cell mediators. Oxaliplatin did not deplete double-positive thymocytes but increased the single-positive CD8+subset. There was also an increase in activated (CD69+) CD8+T cells. Bone-marrow hematopoietic progenitor pool was demonstrably normal following oxaliplatin treatment when compared to the vehicle-treated cohort.Conclusion. Oxaliplatin does not cause systemic immunosuppression and, instead, has the capacity to induce beneficial antitumor immune responses.