Search

The industrial wastes, sewage effluents, agricultural run-off and decomposition of biological waste may cause high environmental concentration of chemicals that can interfere with the cell cycle activating the programmed process of cells death (apoptosis). In order to provide a detailed understanding of environmental pollutants-induced apoptosis, here we reviewed the current knowledge on the interactions of environmental chemicals and programmed cell death. Metals (aluminum, arsenic, cadmium, chromium, cobalt, zinc, copper, mercury and silver) as well as other chemicals including bleached kraft pulp mill effluent (BKME), persistent organic pollutants (POPs), and pesticides (organo-phosphated, organo-chlorinated, carbamates, phyretroids and biopesticides) were evaluated in relation to apoptotic pathways, heat shock proteins and metallothioneins. Although research performed over the past decades has improved our understanding of processes involved in apoptosis in fish, yet there is lack of knowledge on associations between environmental pollutants and apoptosis. Thus, this review could be useful tool to study the cytotoxic/apoptotic effects of different pollutants in fish species., (Copyright © 2018 Elsevier B.V. All rights reserved.) more...

An 8-week feeding trial was performed to assess the effects of dietary white button mushroom (Agaricus bisporus) powder (WBMP) on the mucosal immunity and growth of rainbow trout (Oncorhynchus mykiss). Trout (n = 192; weight 13.76 ± 1.17 g) were stocked in 12 cages (65 × 65 × 65 cm) placed in 4 raceways with a flow-through water system. Trout were fed a basal diet (control group) or a basal diet supplemented with 0.5%, 1%, or 2% WBMP for 8 weeks. Evaluation of total protein levels and lysozyme activity in skin mucus revealed noticeable increases in trout fed 1% or 2% WBMP (P < 0.05), but no significant difference was observed with 0.5% WBMP administration (P > 0.05). The results of sodium dodecyl sulphate-polyacrylamide gel electrophoresis revealed alterations in the protein profile of skin mucus following dietary administration of WBMP. Molecular studies showed a noticeable increase (P < 0.05) in tumor necrosis factor-α messenger RNA in the intestine of WBMP-fed trout, regardless of the inclusion level. Also, fish receiving the 1% or 2% WBMP treatments had a remarkable increase in interleukin (IL)-1β expression compared with the control group (P < 0.05). In a similar way, intestinal IL-8 expression was upregulated with the 1% and 2% WBMP treatments (P < 0.05). However, no significant difference was found between the control group and the 0.5% WBMP treatment group in the case of IL-8 gene expression (P > 0.05). Furthermore, after 8 weeks of WBMP feeding, no improvement was seen in the growth parameters of trout compared with those fish fed the nonsupplemented diet (P > 0.05). These results hint at the potential immunomodulatory effects of dietary WBMP. more...

Pacific white shrimp Litopenaeus vannamei (Boone, 1931) is an important economical shrimp species worldwide, especially in the Middle East region, and farming activities of this species have been largely affected by diseases, mostly viral and bacterial diseases. Scientists have started to use prebiotics for bolstering the immune status of the animal. This study aimed to investigate the influence of Immunogen ® on growth, digestive enzyme activity and immune related gene expression of Litopenaeus vannamei post-larvae. All post-larvae were acclimated to the laboratory condition for 14 days. Upon acclimation, shrimps were fed on different levels of Immunogen ® (0, 0.5, 1 and 1.5 g kg -1 ) for 60 days. No significant differences were detected in weight gain, specific growth rate (SGR) and food conversion ratio (FCR) in shrimp post-larvae in which fed with different levels of Immunogen ® and control diet. The results showed that digestive enzymes activity including protease and lipase increased with different amounts of Immunogen ® in the shrimp diet. Protease activity increased with 1.5 g kg -1 Immunogen ® after 60 days and lipase activity increased with 1 and 1.5 g kg -1 Immunogen ® after 30 and 60 days of the trial respectively (P < 0.05), while amylase activity did not change in response to different levels of Immunogen ® (P > 0.05). The expression of immune related genes including, prophenoloxidase, crustin and g-type lysozyme increased with diet 1.5 g kg -1 Immunogen ® (P < 0.05) while expression of penaeidin gene increased only with experimental diet 1 g kg -1 of Immunogen ® . These results indicated that increase in digestive enzymes activity and expression of immune related genes could modulate the Immunogen ® in the innate immune system in L. vannamei in this study., (Copyright © 2017. Published by Elsevier Ltd.) more...

Apoptosis, a form of programmed cell death, is a critical component in maintaining homeostasis and growth in all tissues and plays a significant role in immunity and cytotoxicity. In contrast to necrosis or traumatic cell death, apoptosis is a well-controlled and vital process characterized mainly by cytoplasmic shrinkage, chromatin condensation, DNA fragmentation, membrane blebbing and apoptotic bodies. Our understanding of apoptosis is partly based on observations in invertebrates but mainly in mammals. Despite the great advantages of fish models in studying vertebrate development and diseases and the tremendous interest observed in recent years, reports on apoptosis in fish are still limited. Although apoptotic machinery is well conserved between aquatic and terrestrial organisms throughout the history of evolution, some differences exist in key components of apoptotic pathways. Core parts of apoptotic machinery in fish are virtually expressed as equivalent to the mammalian models. Some differences are, however, evident, such as the extrinsic and intrinsic pathways of apoptosis including lack of a C-terminal region in the Fas-associated protein with a death domain in fish. Aquatic species inhabit a complex and highly fluctuating environment, making these species good examples to reveal features of apoptosis that may not be easily investigated in mammals. Therefore, in order to gain a wider view on programmed cell death in fish, interactions between the main environmental factors, chemicals and apoptosis are discussed in this review. It is indicated that apoptosis can be induced in fish by exposure to environmental stressors during different stages of the fish life cycle. more...

This experiment was conducted to study the effect of various levels of ACV ® and Propionic acid (PA) on expression of immune related genes and growth performance in white shrimp (Litopenaeus vannamei). Three hundred and seventy-five shrimps with an average initial weight of 10.2 ± 0.04 g were collected and acclimatized for two weeks. Five experimental diets including control diet, 0.5% PA diet and 1%, 2% and 4% ACV ® diets were applied to feed the shrimps. They were fed 4 times a day with 2.5% of body weight. After 60 days of culture, shrimps fed with ACV ® and PA diets showed no significant difference in growth performance. Expression of prophenoloxidase (proPo), lysozyme (Lys), penaeidin-3a (Pen-3a) and Crustin (Cru) genes were determined from hepatopancreas, using the real-time PCR after 15, 30 and 60 days. Expression of Lys and proPo genes was significantly up regulated in shrimps fed with ACV ® and PA diets compared to the control group after 30 and 60 days of treatment. After 15 days, Pen-3a gene expression was significantly higher in PA group compared to the control group. Also, shrimps fed with 1% and 4% ACV ® and PA diets showed significantly increased expression of Pen-3a after 30 days. In contrast, expression of Cru was significantly down regulated in response to ACV ® diets, but, Cru expression in treated shrimps with PA diet was greater than the control group after 30 and 60 days. Overall, the results provided evidence that ACV ® could be used as a natural immunostimulant for shrimps in order to adjust and enhance expression of the immune related genes., (Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.) more...

The present study investigates the effects of supplementation of goldfish (Carassius auratus gibelio) diet with galactooligosaccharide (GOS) on serum immune response, mucosal immune parameters as well as appetite-related (Ghrelin) and immune-related (TNF-1α and TNF-2α) genes expression. One hundred and eighty fish with an average weight of 4.88 ± 0.28 g were stocked in twelve 500-L fiberglass tank assigned to four treatments repeated in triplicates. Fish were fed on experimental diets contain 0.5, 1 and 2% GOS for 6 weeks. Supplementation of diet with GOS had no remarkable effect on goldfish growth performance (P > 0.05). Evaluation of serum innate immune parameters revealed that supplementation of diet with GOS significantly elevated total protein, Albumin, Globulins, Lysozyme and Alkaline phosphatase activity as well as agglutination compared to control group in a dose dependent manner (P < 0.0.5). Also, Fish fed 2% GOS supplemented diet showed increased skin mucus immune response (total protein and lysozyme activity) compared other groups (P < 0.0.5); except in case of ALP activity. Molecular studies on appetite (ghrelin) and inflammatory cytokine (TNF-1α and TNF-2α) genes expression revealed remarkably decrease and increase, respectively in GOS fed fish (P < 0.0.5). These results showed immunomodulatory effects of dietary GOS on serum and skin mucus response as well as expression of inflammatory cytokines in goldfish, though this supplement decreased appetite gene expression and had no effect on growth performance., (Copyright © 2016 Elsevier Ltd. All rights reserved.) more...

The present study investigated the effects of various levels of multi-strain probiotic on the immune related gene expression, digestive enzyme activity, growth performance, body chemical composition and survival of Litopenaeus vannamei post-larvae. After transferring post-larvae of L. vannamei to indoor conditions and subsequent acclimation to laboratory condition for 14 days, the shrimp were fed multi-strain probiotic at four different doses of 0, 0.25, 0.5 and 1.0 g kg(-1) for eight weeks. Shrimp fed 0.5 and 1.0 g kg(-1) probiotic PrimaLac(®) exhibited significantly (p < 0.05) higher weight gain, specific growth rate, body crude protein as well as lower FCR compared to other groups. Feeding on 0.5 and 1 g kg(-1) dietary multi-strain probiotic significantly (p < 0.05) increased the level of body crude protein. Oral administration of 0.5 and 1.0 g kg(-1) multi-strain probiotic significantly (p < 0.05) decreased body crude lipid and body moisture respectively. 30 days after feeding, protease, amylase and lipase activity increased in groups fed 0.5 and 1.0 g kg(-1) probiotic PrimaLac(®). However, on the 60th day, specific protease and amylase activity in all treatment groups were significantly higher than control group (p < 0.05) but lipase activity was higher (p < 0.05) in groups fed 0.5 and 1.0 g kg(-1) multi-strain probiotic. Oral administration of 1.0 g kg(-1) probiotic increased (p < 0.05) the level of prophenoloxidase and g-type lysozyme gene on day 30th and 60th after treatment. On day 30th and 60th, penaeidin gene expression was significantly higher in all treatment groups compared to the control group (p < 0.05). In general, findings of this study demonstrated that oral administration of 0.5 and 1.0 g kg(-1) multi-strain probiotic improved the performance of the fish and increased the expression of immune related genes., (Copyright © 2016. Published by Elsevier Ltd.) more...

Sturgeon is one of the endangered families of fish in the Caspian Sea region, where there is up to 80% of their global caching. Unfortunately, in recent years, increase of pollutants has been resulted in their total population reduction. Due to their benthic nature, sturgeons are at great risk of exposing to contaminants such as cadmium. Despite their endangered status in the Caspian Sea, there are only a few studies on characterizing the relative sensitivity of sturgeons to cadmium. Adverse effects associated with pollution on angiogenesis are mediated by hypoxia inducing factor-1 (HIF-1) and vascular endothelial growth factor (VEGF). In this investigation, gene expression of two distinct HIFs-1, HIF-1α and HIF-2α, and VEGF was investigated at the mRNA transcript levels after exposure of Persian sturgeon (Acipenser persicus) to cadmium. VEGF, HIF-1α and HIF-2α expressions in treated Persian sturgeon were greater than controls. Significant increases (P<0.05) were also observed in cortisol and glucose levels compared to the control group especially in the fish exposed to higher cadmium concentration (800 μg/L). Plasma aspartate aminotransferase (AST), alanine aminotransferase (ALT) and lactic acid dehydrogenase (LDH) levels were increased in the cadmium-exposed fish, although the observed increases were not significant between the control and 200 μg/L cadmium treatment at some sampling time points. Gill tissues also showed histopathological changes in the cadmium treatments. Overall, results indicated that cadmium resulted in some alterations in biochemical parameters, mRNA transcript level expression of two important angiogenesis related genes as well as histological alterations in Persian sturgeon., (Copyright © 2015 Elsevier Inc. All rights reserved.) more...

The present study investigated the effects of various stocking densities on the health status (stress and immune responses) of rainbow trout (Onchorhynchus mykiss). Juvenile rainbow trout were acclimated, placed in circular tanks under stocking densities of 10, 40 and 80 kg m(-3) and reared for 30 days. The relative expression of genes involved in stress and immunity such as HSP70, LyzII, TNF-1α, IL-1β, IL-8 and IFN-γ1 in the head kidney was determined. Serum cortisol, ACTH, total antioxidant capacity, osmolality and lactate were measured after 30 days of culture at different stocking densities (D1:10 kg m(-3), D2: 40 kg m(-3) and D3: 80 kg m(-3)) as indices of stress responses. In addition, the effects of stocking densities on serum complement, bactericidal activity, agglutinating antibody titers, serum IgM, anti-protease activity, serum total protein and alkaline phosphatase of the fish were measured. HSP70 gene expression was significantly density-dependent upregulated in D2 and D3 densities compared to D1 (P < 0.05). Also, there was significant downregulation in expression of LyzII, TNF-1α, IL-1β, IL-8 and IFN-γ1 in fish reared at density of either D2 or D3 (P < 0.05). In terms of stress responses, serum ACTH, cortisol and lactate level showed significant density-dependent increase (P < 0.05) while serum osmolality and total antioxidant capacity showed significant decline (P < 0.05) in fish reared at higher densities (D2 and D3) compared to fish reared at lower density (D1) (P < 0.05). Concordant with the expression of the immune-related genes, the serum complement and bactericidal activity as well as specific antibody titer against Aeromonas hydrophila, IgM and anti-protease activity decreased along with elevation of stocking density from D1 to D3 (P < 0.05). However, different stocking densities had no significant effect on serum total protein level and alkaline phosphatase activity. These results suggested that elevation of stocking densities and crowding resulted in the increase in HSP70 gene expression and the levels of selected stress responses in the serum. However, there was down-regulation of immune genes expression and decreased innate immune responses in the fish. The mRNA expression of the genes and immune parameters that were measured in this study could be helpful in monitoring the health status and welfare of the fish in aquaculture systems particularly in relation to increased stocking densities., (Copyright © 2015 Elsevier Ltd. All rights reserved.) more...

Background: Metal pollution of waterways directly affects human health and can impact the food chain. Seafood living in polluted water can accumulate trace metals. The purpose of this study was to analyze the toxic metals Pb and Cd and the dietary essential metals Zn and Mn in 120 cans of tuna species from four different brands processed in Iran and purchased in 2012., Results: The mean level of metals for each brands of canned fish obtained in mg/kg were as follows: yellowfin tuna (Pb: 0.19 ± 0.015, Zn: 5.77 ± 4.17, Mn: 0.08 ± 0.07, Cd: 0.15 ± 0.12), Kilka (Pb: 0.95 ± 0.88, Zn: 30.47 ± 29.82, Mn: 1.01 ± 0.73, Cd: 0.07 ± 0.05), Kawakawa (Pb: 0.28 ± 0.23, Zn: 6.77 ± 5.21, Mn: 0.17 ± 0.12, Cd: 0.12 ± 0.09), longtail tuna (Pb: 1.59 ± 1.56, Zn: 7.44 ± 6.11, Mn: 0.04 ± 0.03, Cd: 0.06 ± 0.04). Pb, Zn and Cd levels were generally higher than the FAO/WHO permissible limits (Pb: 0.50 mg/kg, Zn: 50.0 mg/kg and Cd: 0.50 mg/kg) and the European Union acceptable dietary limits., Conclusions: Based on the United States Environmental Protection Agency health criteria, there is no health risk associated with Mn concentration in the samples analyzed. The limits of detection of the method for Pb, Zn, Mn and Cd in mg/kg were 0.01, 0.5, 0.01 and 0.01, respectively. The result of the one-way analysis of variance suggested significant variations (p < 0.05) in the concentration of the metals in the different types of canned fish with the following being outside of compliance levels. more...

Among vertebrates, teleost fishes have evolved the most impressive adaptations to variable oxygen tensions in water (Shoubridge and Hochachka 1980; Nilsson and Randall 2010). Under conditions of oxygen deprivation (hypoxia), major changes in gene expression are mediated by hypoxia-inducible factors (HIF alpha). Here we show that hif alpha genes were duplicated in the teleost specific whole-genome duplication. Although one of each paralogous gene pair was lost in most teleosts, both copies were retained in cyprinids. Computational analyses suggest that these duplicates have become subfunctionalized with complementary changes in coding and regulatory sequences within each paralogous gene pair. We tested our predictions with comparisons of hif alpha transcription in zebrafish, a cyprinid, and sturgeon, an outgroup that diverged from teleosts before the duplication event. Our experiments revealed distinct transcriptional profiles in the cyprinid duplicates: while one of each paralogous pair maintained the ancestral developmental response, the other was more sensitive to changes in oxygen tension. These results demonstrate the subfunctionalization of cyprinid hif alpha paralogs for specialized roles in development and the hypoxic stress response., (© 2012 The Author(s). Evolution© 2012 The Society for the Study of Evolution.) more...

In the present study, we surveyed developmental changes in the transcription of growth hormone (gh), insulin-like growth factor-I (igf-I), ghrelin (ghrl) and vascular endothelial growth factor (vegf) genes in the largest freshwater fish, European sturgeon (Beluga, Huso huso) and compared the same parameters to that of its phylogenically close moderate-sized species, Persian sturgeon (Acipenser persicus). The transcripts of gh, igf-I, ghrl and vegf were detected at all developmental time-points of Persian sturgeon and Beluga from embryos to juvenile fish. Changes in normalized gh, igf-I, ghrl and vegf transcription by using the geometric average of genes encoding ribosomal protein L6 (RPL6) and elongation factor (EF1A) over the time of development of Persian sturgeon and Beluga were statistically significant (P<0.05). Our results showed that the mRNA expression levels of both igf-I and ghrl were low during early larval development and then increased significantly to the late larval time-points when larvae started exogenous feeding. In both Beluga and Persian sturgeon, after a low mRNA expression during the embryonic stage, the transcript levels of vegf displayed an increasing trend during yolk-sac fry, consistent with organogenesis. The vegf level remained constantly high in the time of exogenous feeding. The highest detection of gh transcripts coincided with the end of the embryonic stage (hatching time) in Persian sturgeon and 3 days-post-hatching (dph) in Beluga. In Persian sturgeon, the gh transcript started to decrease to the rest of the developmental time-points, whereas in Beluga gh transcript had a marked second increase from the time of exogenous feeding (20-dph). This Beluga specific increase in gh transcription may be associated with the marked growth rate and extraordinary size of this fish species., (Copyright © 2012 Elsevier Inc. All rights reserved.) more...