Genetics of metallothioneins in Drosophilamelanogaster

Co-administration of resveratrol rescued lead-induced toxicity in Drosophila melanogaster

Lead toxicity poses a significant environmental concern linked to diverse health issues. This study explores the potential mitigating effects of resveratrol on lead-induced toxicity in Drosophila melanogaster. Adult fruit flies, aged three days, were orally exposed to lead (60 mg/L), Succimer (10 mg), and varying concentrations of resveratrol (50, 100, and 150 mg). The investigation encompassed the assessment of selected biological parameters, biochemical markers, oxidative stress indicators, and antioxidant enzymes. Resveratrol exhibited a dose-dependent enhancement of egg-laying, eclosion rate, filial generation output, locomotor activity, and life span in D. melanogaster, significantly to 150 mg of diet. Most of the investigated biochemical parameters were significantly rescued in lead-exposed fruit flies when co-treated with resveratrol (p < 0.05). However, oxidative stress remained unaffected by resveratrol. The findings suggest that resveratrol effectively protects against lead toxicity in Drosophila melanogaster and may hold therapeutic potential as an agent for managing lead poisoning in humans.

Metallothionein-2: An emerging target in inflammatory diseases and cancers

Metallothionein-2 (MT-2) was originally discovered as a mediator of zinc homeostasis and cadmium detoxification. However, MT-2 has recently received increased attention because altered expression of MT-2 is closely related to various diseases such as asthma and cancers. Several pharmacological strategies have been developed to inhibit or modify MT-2, revealing its potential as drug target in diseases. Therefore, a better understanding of the mechanisms of MT-2 action is warranted to improve drug development for potential clinical applications. In this review, we highlight recent advances in determining the protein structure, regulation, binding partners, and new functions of MT-2 in inflammatory diseases and cancers.

Chronic exposure to the star polycation (SPc) nanocarrier in the larval stage adversely impairs life history traits in Drosophila melanogaster

BACKGROUND

Nanomaterials are widely used as pesticide adjuvants to increase pesticide efficiency and minimize environmental pollution. But it is increasingly recognized that nanocarrier is a double-edged sword, as nanoparticles are emerging as new environmental pollutants. This study aimed to determine the biotoxicity of a widely applied star polycation (SPc) nanocarrier using Drosophila melanogaster, the fruit fly, as an in vivo model.

RESULTS

The lethal concentration 50 (LC₅₀) value of SPc was identified as 2.14 g/L toward third-instar larvae and 26.33 g/L for adults. Chronic exposure to a sub lethal concentration of SPc (1 g/L) in the larval stage showed long-lasting adverse effects on key life history traits. Exposure to SPc at larval stage adversely impacted the lifespan, fertility, climbing ability as well as stresses resistance of emerged adults. RNA-sequencing analysis found that SPc resulted in aberrant expression of genes involved in metabolism, innate immunity, stress response and hormone production in the larvae. Orally administrated SPc nanoparticles were mainly accumulated in intestine cells, while systemic responses were observed.

CONCLUSIONS

These findings indicate that SPc nanoparticles are hazardous to fruit flies at multiple levels, which could help us to develop guidelines for further large-scale application.

Interactions and toxicity of non-essential heavy metals (Cd, Pb and Hg): lessons from Drosophila melanogaster

Some heavy metals are essential in trace amounts, enhancing enzyme functioning and other intracellular molecules. Others are explicitly toxic at low concentrations, increasing the risk of organ-related toxicity. Non-essential metals have similar mechanisms of toxicity to essential metals. These include the modifiable change in oxidation states, interaction with sulfhydryl moieties of proteins and indirect modification of nucleic acids. Ultimately, oxidative stress is generated, and potentiation of damage ensues. The susceptibility, sensitivity, genetic resources, and cellular response of Drosophila melanogaster to heavy metal exposure and toxicity have made this insect appropriate for toxicological studies. In this review, we focus on the toxicological impacts of non-essential metals (Cd, Pb, and Hg) in Drosophila and discuss its cellular and developmental responses to increasing concentrations of these metals. We also suggest current or proposed therapeutic alternatives, as well as dimensions that may improve the studies of non-essential metal biology.

Molecular physiology of zinc in Drosophila melanogaster

New research in Drosophila melanogaster has revealed the molecular mechanisms of zinc involvement in many biological processes. A newly discovered Metallothionein is predicted to have a higher zinc specificity than the other isoforms. Zinc negatively regulates tyrosine hydroxylase activity by antagonizing iron binding, thus rendering the enzyme ineffective or non-functional. The identification of a new chaperone of the protein disulfide isomerase family provided mechanistic insight into the protein trafficking defects caused by zinc dyshomeostasis in the secretory pathway. Insect models of tumor pathogenesis indicate that zinc regulates the structural stabilization of cells by transcriptionally regulating matrix metalloproteinases while zinc dyshomeostasis in the secretory pathway modulates cell signaling through endoplastic recticulum stress.