HSP27 modulates survival signaling in endosulfan-exposed human peripheral blood mononuclear cells treated with curcumin

Hsp27, a potential EcR target, protects nonylphenol-induced cellular and organismal toxicity in Drosophila melanogaster

Deciphering the potential mechanism of chemical-induced toxicity enables us to alleviate the cellular and organismal dysfunction. The environmental presence of nonylphenol (endocrine disruptor) has a major health concern due to its widespread usage in our day-to-day life. The current study establishes a novel functional link among nonylphenol-induced oxidative stress, Heat shock protein 27 (Hsp27, member of stress protein family), and Ecdysone receptor (EcR, a nuclear receptor), which eventually coordinates the nonylphenol-induced sub-cellular and organismal level toxicity in a genetically tractable model Drosophila melanogaster. Drosophila larvae exposed to nonylphenol (0.05, 0.5 and 5.0 μg/mL) showed a significant decrease in Hsp27 and EcR mRNA levels in the midgut. In concurrence, reactive oxygen species (ROS) levels were increased with a corresponding decline in glutathione (GSH) level and Thioredoxin reductase (TrxR) activity. Increased lipid peroxidation (LPO), protein carbonyl (PC) contents, and cell death were also observed in a correlation with the nonylphenol concentrations. Sub-cellular toxicity poses a negative organismal response, which was evident by delayed larval development and reduced Drosophila emergence. Subsequently, a positive genetic correlation (p < 0.001) between EcR and Hsp27 revealed that nonylphenol-dependent EcR reduction is a possible link for the downregulation of Hsp27. Further, Hsp27 overexpression in midgut cells showed a reduction in nonylphenol-induced intracellular ROS, LPO, PC content, and cell death through the TrxR mediated regenerative pathway and reduced GSH level improving the organismal response to the nonylphenol exposure. Altogether, the study elucidates the potential EcR-Hsp27 molecular interactions in mitigating the nonylphenol-induced cellular and organismal toxicity.

Endosulfan exposure alters transcription of genes involved in the detoxification and stress responses in Physella acuta

Endosulfan is a persistent pesticide that has been in use for more than five decades. During this time, it has contaminated soil, air, and water reservoirs worldwide. It is extremely toxic and harmful to beneficial non-target invertebrates, aquatic life, and even humans upon consumption, which is one of the many dangers of this pesticide since it biomagnifies in the food chain. The effects of three endosulfan concentrations (1, 10, and 100 µg/L) on the freshwater snail Physella acuta, an invasive cosmopolitan species, were examined over a week-long exposure period. Alterations in the expression of ten genes related to stress and xenobiotic detoxification were measured against the endogenous controls rpL10 and GAPDH by Real-Time polymerase chain reaction. Four genes are described here for the first time in this species, namely Hsp60, Grp78, GSTk1, and GSTm1. The rest of genes were Hsp90, sHsp16.6, cyp2u1, cyp3a7, cyp4f22, and MRP1. cyp2u1, sHsp16.6, and Grp78 expression were all altered by endosulfan. These results suggest a low pesticide concentration activates the acute response in P. acuta by affecting detoxification and stress responses and alter endoplasmic reticulum function and lipid metabolism. Furthermore, the newly identified genes extend the number of processes and cellular locations that can be analyzed in this organism.

Effects of endosulfan isomers on cytokine and nitric oxide production by differentially activated RAW 264.7 cells

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Non-cytotoxic concentrations of endosulfan suppressed NO production.

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Suppression of NO was a more sensitive endpoint than suppression of TNF.

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Endosulfan alpha had greater cytotoxic potency than endosulfan beta.

Endosulfan is an organochlorine insecticide comprised of two isomers: endosulfan-α and endosulfan-β. Endosulfan exposure has been shown to elevate some inflammatory factors, such as nitric oxide (NO) and tumor necrosis factor (TNF), in animals or cultures of animal cells. Because the two endosulfan isomers can vary in their biological activities, the goal of this study was to determine if individual endosulfan isomers differentially impact production of NO or TNF by the mouse macrophage cell RAW 264.7 at non-cytotoxic levels. We found elevated TNF with exposure to endosulfan-α (not endosulfan-β), but only at concentrations that were cytotoxic (≥100 μM), whereas neither endosulfan isomer altered baseline levels of NO at any concentration up to 300 μM. In interferon (IFN)-γ-activated cultures, NO levels were significantly suppressed by either endosulfan isomer at 10 μM (the lowest concentration examined), whereas only endosulfan-β significantly lowered TNF levels at non-cytotoxic concentrations. In lipopolysaccharide (LPS)-activated cultures, both endosulfan isomers significantly reduced NO, but not TNF, at non-cytotoxic concentrations. These results suggest that the endosulfan isomers have some capacity to alter inflammatory responses differentially, particularly with IFN-γ stimulation.