Combining proteomics and lipid analysis to unravel Confidor stress response in Saccharomyces cerevisiae

Metabolic perturbations in zebrafish (Danio rerio) larvae exposed to sulfentrazone and imidacloprid

The intensive and widespread application of pesticides in agroecosystems can lead to the simultaneous exposure of non-target aquatic organisms to insecticides and herbicides. However, the underlying mechanisms through which aquatic organisms undergo metabolic reprogramming to withstand the combined effects of the insecticide imidacloprid (IMI) and herbicide sulfentrazone (SUL) remain poorly elucidated. This study employs metabolomics to investigate the effects of individual and combined exposures to IMI and SUL on zebrafish (Danio rerio), aiming to simulate complex environmental conditions. Metabolomics analysis revealed extensive metabolic reprogramming in larvae induced by the selected agrochemicals. Both individual and combined exposures disrupted nucleotide metabolism, inhibited glycolysis, and led to the accumulation of acetylcholine through the shared modulation of differential metabolites. Notably, individual exposure exhibited a unique mode of action. Larvae exposed to IMI alone showed mitochondrial dysfunction, potentially stemming from interference with the electron transport chain, while SUL-induced disruptions were associated with glycerophospholipid accumulation, marking it as a critical target. Additionally, calculations of the metabolic effect level index indicated antagonistic interactions between SUL and IMI mixtures at an overall metabolic level. The results obtained through investigating the lethal and sub-lethal effects also revealed that the simultaneous application of SUL and IMI may have the potential to diminish acute and developmental toxicity in zebrafish. This study underscores the significance of metabolomics as a valuable and effective strategy for deciphering the toxicity and interactions of agrochemical mixtures.

Discovery of novel phenylhydrazone-based oxindole-thiolazoles as potent antibacterial agents toward Pseudomonas aeruginosa

With the soaring of bacterial infection and drug resistance, it is imperative to exploit new efficient antibacterial agents. This work constructed a series of unique phenylhydrazone-based oxindole-thiolazoles to combat monstrous bacterial resistance. Some target molecules showed potent antibacterial activity, among which oxindole-thiolimidazole derived carboxyphenylhydrazone 4e exhibited an 8-fold stronger inhibitory ability than norfloxacin on the growth of P. aeruginosa, with MIC value of 1 μg/mL. Compound 4e with imperceptible hemolysis could hamper bacterial biofilm formation and significantly impede the development of bacterial resistance. Subsequent mechanism studies demonstrated that 4e could destruct bacterial cytoplasmic membrane, causing the leakage of cellular contents (protein and nucleic acid). Moreover, metabolic stagnation and intracellular oxidative stress caused by 4e expedited the death of bacteria. Furthermore, molecule 4e existed supramolecular interactions with DNA to block DNA proliferation. These research results provided a promising light for phenylhydrazone-based oxindole-thiolazoles as novel potential antibacterial agents.

Discovery of novel purinylthiazolylethanone derivatives as anti-Candida albicans agents through possible multifaceted mechanisms

An unprecedented amount of fungal and fungal-like infections has recently brought about some of the most severe die-offs and extinctions due to fungal drug resistance. Aimed to alleviate the situation, new effort was made to develop novel purinylthiazolylethanone derivatives, which were expected to combat the fungal drug resistance. Some prepared purinylthiazolylethanone derivatives possessed satisfactory inhibitory action towards the tested fungi, among which compound 8c gave a MIC value of 1 μg/mL against C. albicans. The active molecule 8c was able to kill C. albicans with undetectable resistance as well as low hematotoxicity and cytotoxicity. Furthermore, it could hinder the growth of C. albicans biofilm, thus avoiding the occurrence of drug resistance. Mechanism research manifested that purinylthiazolylethanone derivative 8c led to damage of cell wall and membrane disruption, so protein leakage and the cytoplasmic membrane depolarization were observed. On this account, the activity of fungal lactate dehydrogenase was reduced and metabolism was impeded. Meanwhile, the increased levels of reactive oxygen species (ROS) and reactive nitrogen species (RNS) disordered redox equilibrium, giving rise to oxidative damage to fungal cells and fungicidal effect.

Response of Saccharomyces cerevisiae W303 to Iron and Lead Toxicity in Overloaded Conditions

Yeast Saccharomyces cerevisiae is an ideal model organism for studying molecular mechanisms of the stress response provoked by metals. In this work, yeast cells response to iron (Fe³⁺) or lead (Pb²⁺) exposure was tested and compared. Survival test was used to determine testing doses of metal ions-for Fe³⁺ it was 4 mM and for Pb²⁺ 8 mM. These (high, over-loaded) doses provoked comparable values of growth inhibition, but different values in vitality measurement. The percentage of metabolically active cells, determined by fluorescent FUN-1 dye, was lower in Pb²⁺ than in Fe³⁺ treated cells. Besides, endogenous antioxidant defence systems in the cells treated with Pb²⁺ were less efficient compared to Fe³⁺. At the mitochondrial level, the effects of metal ions were in correlation with the results of cell metabolic activity. The mitochondrial proteome of Pb²⁺ treated cells showed the domination of protein downregulation. Yeast cells treated either with Fe³⁺ or Pb²⁺ shared 19 common significantly changed proteins. The affected proteins were involved in different cellular process and amongst them only five proteins belong to energy and carbohydrate metabolism, and protein biosynthesis. Based on all obtained results, it is possible to conclude that the effects of Fe³⁺ and Pb²⁺ on yeast cells show rather specific patterns of toxicity and stress response.