Modulation of stress related protein genes in the bass (Epinephelus guaza) caught from the Gulf of Suez, the Red Sea, Egypt

Interactive effects of venlafaxine and thermal stress on zebrafish (Danio rerio) inflammatory and heat shock responses

Venlafaxine (VFX), a commonly prescribed antidepressant often detected in wastewater effluent, and acute temperature elevations from climate change and increased urbanization, are two environmental stressors currently placing freshwater ecosystems at risk. This study focused on understanding if exposure to VFX impacts the agitation temperature (T_ag) and critical thermal maximum (CT_max) of zebrafish (Danio rerio). Additionally, we examined the interactive effects of VFX and acute thermal stress on zebrafish heat shock and inflammatory immune responses. A 96 h 1.0 μg/L VFX exposure experiment was conducted, followed by assessment of thermal tolerance via CT_max challenge. Heat shock proteins and pro-inflammatory immune cytokines were quantified through gene expression analysis by quantitative PCR (qPCR) on hsp 70, hsp 90, hsp 47, il-8, tnfα, and il-1β within gill and liver tissue. No significant changes in agitation temperature between control and exposed fish were observed, nor were there any differences in CT_max based on treatment. Unsurprisingly, hsp 47, 70, and 90 were all upregulated in groups exposed solely to CT_max, while only hsp 47 within gill tissue showed signs of interactive effects, which was significantly decreased in fish exposed to both VFX and CT_max. No induction of an inflammatory response occurred. This study demonstrated that environmentally relevant concentrations of VFX have no impact on thermal tolerance performance in zebrafish. However, VFX can cause diminished function of protective heat shock mechanisms, which could be detrimental to freshwater fish populations and aquatic ecosystems as temperature spikes become more frequent from climate change and urbanization near watersheds.

Environmentally relevant concentrations of Triclosan cause transcriptomic and biomolecular alterations in the hatchlings of Labeo rohita

Suppression (p ≤ 0.05) of antioxidative/detoxification (except GPx and CYP3a) and cytoskeletal (except DHPR) genes but induction of metabolic (except for AST and TRY) and heat shock (except HSP60) genes of Labeo rohita hatchlings after 14 days of exposure to environmentally relevant concentrations of Triclosan (0.0063, 0.0126, 0.0252 and 0.06 mg/L) was followed by an increase (p ≤ 0.05) for most of the genes after 10 days recovery period. After recovery, LDH, ALT, CK, CHY, PA, HSP47 and DHPR declined, while SOD, CAT, GST, GR, GPx, CYP1a, CYP3a, AST, AChE, TRY, HSP60, HSP70, HSc71, HSP90 MLP-3, α-tropomyosin, desmin b and lamin b1 increased over exposure. Peak area of biomolecules (except 3290-3296, 2924-2925 and 2852-2855 cm^-1) declined (p ≤ 0.01) more after recovery [except for an increase (p ≤ 0.01) at 1398-1401 cm^-1]. CYP3a, CK, HSP90, MLP-3 and secondary structure of amide A are the most sensitive markers for the environmentally relevant concentrations of Triclosan.

Expression patterns of heat shock protein genes in Rita rita from natural riverine habitat as biomarker response against environmental pollution

River pollution is one of the principal environmental concerns and biomonitoring tools can play an important role in pollution assessment in the riverine environment. Heat shock proteins (Hsps) have been found to be suitable tools for monitoring stress response. In the present study, expression analyses of hsp genes (hsp27, hsp47, hsp60, hsp70, hsc70, and hsp90) and selected hsp-regulatory genes (hsf1, hyou1, ask1, jnk) were carried out by RT-qPCR in catfish Rita rita collected from selected stretches of river Ganga to investigate changes in their expression patterns as biomarker response. Water quality characteristics were measured in terms of physico-chemical characteristics (DO, BOD, COD, pH, conductivity), element profile (arsenic, mercury, cadmium, lead, chromium, zinc, copper) and persistent organic pollutants (POPs; HCH, DDT, aldrin, endosulphan, heptachlor). Water quality index was calculated and sampling sites were categorized as good/medium/bad. Multivariate analysis was carried out taking the water quality parameters and the fold changes in hsp gene expression as variables, which showed that hsp47 and hsp70b correlated well with BOD, an indicator of organic pollution. To identify the organic pollutant(s) which could be influencing the expression of hsps, again multivariate analysis was employed taking concentration of POPs and fold changes of hsps, which showed up-regulation of hsp47 and hsp70b (HSP72i) correlated well with concentrations of aldrin and HCH. Synergistic effects of these POPs could be responsible for the up-regulation of said hsps, although individually present in low concentration; thus, indicating synergistic effect of the POPs on hsp47 and hsp70b up-regulation as biomarker response.

Biochemical indicators and biomarkers in chub (Squalius cephalus L.) from the Sava River

Biochemical indicators and biomarkers were analyzed in the liver and gills of chub caught in three localities along the Sava River exposed to different environmental impacts. Sampling sites were: downstream from Zagreb (Zgd), downstream Sremska Mitrovica (SM) and downstream from Belgrade (Bgd). We observed that the relative amounts and levels of activity of Cu, Zn containing superoxide dismutase and glutathione in both the liver and gills, and the relative amounts of heat shock protein (HSP90) and metallothioneins in the gills were highest in the Zgd locality, suggesting a higher impact of metal pollution. The Zgd locality had higher concentrations of trace metals in the water, especially iron. In the SM and Bgd localities, higher relative levels of glutathione peroxidase and catalase were recorded (especially in SM) as compared to the Zgd locality, pointing to the presence of hydrogen peroxide and different classes of organic peroxides. Low water oxygen and high temperature levels in the Bgd locality suggesting different metabolic activity between examined locations. Our results suggest that different presence and concentrations of individual environmental factors (total environment) influence the way how fish establish homeostasis.

Assessment of pesticide residues and gene expression in common carp exposed to atrazine and chlorpyrifos: Health risk assessments

This study assessed the impacts of atrazine (ATR), chlorpyrifos (CPF) and combined ATR/CPF exposure on the kidney of common carp (Cyprinus carpio L.). The carp were sampled after a 40-d exposure to CPF and ATR, individually or in combination, followed by a 40-d recovery to measure the expression levels of heat shock proteins genes (HSP60, HSP70 and HSP90) and pesticide residues in the kidney tissue. The results revealed that the mRNA and protein levels of HSP60, HSP70 and HSP90 were induced in the kidney of common carp by ATR, CPF, and ATR/CPF mixture. The accumulated amounts of ATR, CPF, and their metabolites in the kidney tissues exhibited dose-dependency. These results exhibited that increasing concentration of ATR and CPF in the environment causes considerable stress for common carp, suggesting that the expression levels of HSP60, HSP70 and HSP90 may act as potential biomarkers for assessing the environmental ATR and CPF risk for carp.