Expression analysis of heat shock genes in the skin, spleen and blood of common carp (Cyprinus carpio) after cadmium exposure and hypothermia

Huanglian Jiedu Decoction enhances the stability of atherosclerotic plaques through SLC2A1-mediated efferocytosis

BACKGROUND

Atherosclerotic (AS) plaques require a dense necrotic core and a robust fibrous cap to maintain stability. While previous studies have indicated that the traditional Chinese medicine Huang Lian Jie Du Decoction (HLJDD) possesses the capability to stabilize AS plaques, the underlying mechanisms remain obscure. This study aims to delve deeper into the potential mechanisms by which HLJDD improves AS through an integrated research strategy.

METHODS

Leveraging an AS model in ApoE-/- mice exposed to a high-fat diet (HFD), we scrutinized the therapeutic effects of HLJDD using microscopic observations, oil red O staining, HE staining and Masson staining. Employing comprehensive techniques of network pharmacology, bioinformatics, and molecular docking, we elucidated the mechanism by which HLJDD stabilizes AS plaques. In vitro experiments, utilizing ox-LDL-induced macrophages and apoptotic vascular smooth muscle cells (VSMCs), assessed the impact of HLJDD on efferocytosis and the role of SLC2A1.

RESULTS

In vivo experiments showcased the efficacy of HLJDD in reducing the quantity of aortic plaques, diminishing lipid deposition, and enhancing plaque stability in AS mice. Employing network pharmacology and machine learning, we pinpointed SLC2A1 as a crucial regulatory target. Molecular docking further validated the binding of HLJDD components with SLC2A1. The experiments demonstrated a dose-dependent upregulation in SLC2A1 expression by HLJDD, amplifying efferocytosis. Importantly, this effect was reversed by the SLC2A1 inhibitor STF-31, highlighting the pivotal role of SLC2A1 as a target.

CONCLUSION

The HLJDD can modulate macrophage efferocytosis by enhancing the expression levels of SLC2A1, thereby improving the stability of atherosclerotic plaques.

Sea water acclimation of rainbow trout (Oncorhynchus mykiss) modulates the mucosal transcript immune response induced by Vibrio anguillarum and Aeromonas salmonicida vaccine, and prevents further transcription of stress-immune genes in response to acute stress

Mucosal tissues appear to be more important in fish than in mammals due to living in a microbial-rich aquatic milieu, yet the complex interaction between the immune and the neuroendocrine system in these tissues remains elusive. The aim of this work was to investigate the mucosal immune response in immunized rainbow trout vaccinated with Alpha ject vaccine (bivalent), kept in fresh water (FW) or transferred to seawater (SW), and to evaluate their response to acute stress (chasing). Acute stress resulted in higher levels of plasma cortisol (Sham + Stress and Vaccine + Stress). A similar response was observed in skin mucus, but it was lower in Vaccine + Stress compared with stressed fish. With a few exceptions, minimal alterations were detected in the transcriptomic profile of stress-immune gene in the skin of vaccinated and stressed fish in both FW and SW. In the gills, the stress elicited activation of key stress-immune components (gr1, mr, β-ar, hsp70, c3, lysozyme, α-enolase, nadph oxidase, il1β, il6, tnfα, il10 and tgfβ1) in FW, but fewer immune changes were induced by the vaccine (nadph oxidase, il6, tnfα, il10 and igt) in both SW and FW. In the intestine, an array of immune genes was activated by the vaccine particularly those related with B cells (igm, igt) and T cells (cd8α) in FW with no stimulation observed in SW. Therefore, our survey on the transcriptomic mucosal response demonstrates that the immune protection conferred by the vaccine to the intestine is modulated in SW. Overall, our results showed: i) plasma and skin mucus cortisol showed no additional stress effect induced by prolonged SW acclimation, ii) the stress and immune response were different among mucosal tissues which indicates a tissue-specific response to specific antigens/stressor. Further, the results suggest that the systemic immune organs may be more implicated in infectious events in SW (as few changes were observed in the mucosal barriers of immunized fish in SW) than in FW.

The effect of lavender on mood disorders associated with the use of combined oral contraceptives (COCs): a triple-blinded randomized controlled trial

BACKGROUND

The use of contraceptive methods is influenced by their effectiveness, availability, and minimal side effects. OCPs are one of the most effective and widely used methods of pregnancy prevention worldwide. This method not only prevents pregnancy but also helps prevent and treat other diseases. One of the main reasons for discontinuing this method is the emotional disturbances associated with its use. Lavender is an evergreen, fragrant plant that has gained significant attention for its anti-anxiety effects. This study was conducted to investigate the effect of lavender essential oil capsules on mood disorders during the use of COCs.

METHODS

This triple-blinded clinical trial was conducted on 60 married women (aged 15-49 years old) who were consumers of COCs, referring to 26 health centers in Tabriz, Iran. The participants were randomly assigned to either the intervention (consuming one gelatin capsule containing 80 mg LEO daily) or control (consuming one placebo capsule daily) group. The intervention continued for 56 days. Scores for positive and negative were determined using the Positive and Negative Affect Schedule (PANAS) questionnaire; and for stress, depression, and anxiety were measured using the DASS-21 questionnaire on day's 28th and 56th post-intervention. Data analysis was conducted using the t-test and ANOVA with repeated measures, and a p-value of < 0.05 was considered significant for all analyses.

RESULTS

A statistically significant difference was observed in mood disorders, stress, and depression between women receiving LEO or placebo. The consumption of LEO increased the positive mood on day 28 [MD (95% CI): 4.5 (2.1 to 7.0), p = 0.001] and day 56 [5.9 (3.4 to 8.3), p < 0.001] while decreased the negative mood on day 28 [MD (95% CI): -3.5 (-5.3 to -1.3), p < 0.001] and day 56 [-4.3 (-6.3 to -2.2), p < 0.001], stress on day 28 [MD (95% CI): -4.9 (-7.1 to -2.8), p = 0.001] and day 56 [-5.3 (-7.6 to -3.1), p < 0. 001], and depression on day 28 [MD (95% CI): -3.0 (-4.9 to 1.1), p = 0.003] and day 56 [-3.1 (-5.0 to 1.2), p = 0.002]. There was no statistically significant difference between the two groups in terms of anxiety.

CONCLUSIONS

The consumption of LEO with COCs improved mood disorders and reduced stress and depression. The use of hormonal contraceptives and mood changes should be considered by providers. Therefore, regarding the possibility of mood changes, it is expected that appropriate counseling and education will be provided to women who consume COC., providing appropriate solutions, including the simultaneous use of LEO.

Antioxidant therapy for hepatic diseases: a double-edged sword

Liver diseases are complex conditions, significantly influenced by oxidative stress. This comprehensive review assesses the therapeutic role of antioxidants like l-ascorbic acid and α tocopherol, beta-carotene, various minerals, and plant-based ingredients in mitigating oxidative stress-induced liver diseases. The manuscript delves into the critical influence of genetic and epigenetic factors on disease susceptibility, progression, and response to antioxidant therapy. While animal studies suggest antioxidant efficacy in liver disease treatment, human trials remain inconclusive, and caution is advised due to its possible potential pro-oxidant effects. Moreover, the interactions of antioxidants with other drugs necessitate careful consideration in the management of polypharmacy in liver disease patients. The review underscores the need for further research to establish the clinical benefits of antioxidants with understanding of possible antioxidant toxicities to elucidate the intricate interplay of genetic, epigenetic, and environmental factors in liver diseases. The aim is to foster a better understanding of the knowledge on hepatic disease management with judicial antioxidant therapies.

Anticancer Potential of the Plant-Derived Saponin Gracillin: A Comprehensive Review of Mechanistic Approaches

With the increasing prevalence of cancer and the toxic side effects of synthetic drugs, natural products are being developed as promising therapeutic approaches. Gracillin is a naturally occurring triterpenoid steroidal saponin with several therapeutic activities. It is obtained as a major compound from different Dioscorea species. This review was designated to summarize the research progress on the anti-cancer activities of gracillin focusing on the underlying cellular and molecular mechanisms, as well as its pharmacokinetic features. The data were collected (up to date as of May 1, 2023) from various reliable and authentic literatures comprising PubMed, Springer Link, Scopus, Wiley Online, Web of Science, ScienceDirect, and Google Scholar. The findings demonstrated that gracillin displays promising anticancer effects through various molecular mechanisms, including anti-inflammatory effects, apoptotic cell death, induction of oxidative stress, cytotoxicity, induction of genotoxicity, cell cycle arrest, anti-proliferative effect, autophagy, inhibition of glycolysis, and blocking of cancer cell migration. Additionally, this review highlighted the pharmacokinetic features of gracillin, indicating its lower oral bioavailability. As a conclusion, it can be proposed that gracillin could serve as a hopeful chemotherapeutic agent. However, further extensive clinical research is recommended to establish its safety, efficacy, and therapeutic potential in cancer treatment.

Remediation of Cadmium Stress in Strawberry Plants Using Humic Acid and Silicon Applications

(1) Background: Strawberry plants are strongly affected by heavy-metal-contaminated soils, which affects plant growth, yield and fruit quality. The aim of this work was to study the effects of a combination and individual application of silicon (Si) and humic acid (HA) on growth and development of Rubygem strawberries exposed to cadmium (Cd) in greenhouse conditions. (2) Methods: Morphological, physiological and biochemical parameters, including minerals in roots and leaves were determined. (3) Results: Cd stress in strawberry plants decreased plant fresh and dry weight; leaf stomatal conductance; leaf relative water content and chlorophyll content; number of leaves; leaf area; leaf N, P and K levels; and root P, N, Mg, K and Ca contents. Cd increased membrane permeability, leaf temperature, proline levels and lipid peroxidation. Si and HA individual applications to strawberries mitigated the negative effect of Cd stress on biochemical, physiological, morphological and minerals parameters by decreasing membrane permeability, leaf temperature, proline levels and lipid peroxidation. (4) Conclusions: Our findings highlighted that applications of Si, HA and Si + HA were effective in conferring Cd tolerance in strawberry plants by upregulating their many morphological, physiological and biochemical properties and reducing Cd stress.

Genus Lupinus (Fabaceae): a review of ethnobotanical, phytochemical and biological studies

OBJECTIVES

Lupinus is a large and diverse genus comprising approximately 200 species, belonging to the family Fabaceae. Lupinus plants have been used for heart stimulants, nerves, urinary tract infections, skin disorders, and psoriasis in folk medicine. This review aims to recap the traditional medicinal uses, nutritional value, phytochemical profile, and biological activities of Lupinus species.

KEY FINDINGS

From the literature survey, Lupinus is considered as a factory of various phytochemicals like flavonoids, iso-flavonoids, alkaloids, triterpenoids. The presence of proteins, essential fatty acids, and amino acids, as well as alkaloids, minerals, and dietary fibers, indicated that the plants in this genus had a high nutritional value. The Lupinus extracts displayed promising antidiabetic, anticancer, antimicrobial, antidiabetic, antihypertensive, antioxidant, anti-inflammatory, and antimicrobial activities.

CONCLUSIONS

The current review provides updated information that could drive the researchers for further studies. The in vitro and in vivo experiments have demonstrated various pharmacological properties. Some pharmacokinetic and toxicological investigations are warranted to ensure its safety and validity for human use.

An updated review of cold shock and cold stress in fish

Temperature is critical in regulating virtually all biological functions in fish. Low temperature stress (cold shock/stress) is an often-overlooked challenge that many fish face as a result of both natural events and anthropogenic activities. In this study, we present an updated review of the cold shock literature based on a comprehensive literature search, following an initial review on the subject by M.R. Donaldson and colleagues, published in a 2008 volume of this journal. We focus on how knowledge on cold shock and fish has evolved over the past decade, describing advances in the understanding of the generalized stress response in fish under cold stress, what metrics may be used to quantify cold stress and what knowledge gaps remain to be addressed in future research. We also describe the relevance of cold shock as it pertains to environmental managers, policymakers and industry professionals, including practical applications of cold shock. Although substantial progress has been made in addressing some of the knowledge gaps identified a decade ago, other topics (e.g., population-level effects and interactions between primary, secondary and tertiary stress responses) have received little or no attention despite their significance to fish biology and thermal stress. Approaches using combinations of primary, secondary and tertiary stress responses are crucial as a research priority to better understand the mechanisms underlying cold shock responses, from short-term physiological changes to individual- and population-level effects, thereby providing researchers with better means of quantifying cold shock in laboratory and field settings.

The effects of population and thermal acclimation on the growth, condition and cold responsive mRNA expression of age-0 lake sturgeon (Acipenser fulvescens)

In Manitoba, Canada, wild lake sturgeon (Acipenser fulvescens) populations exist along a latitudinal gradient and are reared in hatcheries to bolster threatened populations. We reared two populations of lake sturgeon, one from each of the northern and southern ends of Manitoba and examined the effects of typical hatchery temperatures (16°C) as well as 60-day acclimation to elevated rearing temperatures (20°C) on mortality, growth and condition throughout early development. Additionally, we examined the cold shock response, which may be induced during stocking, through the hepatic mRNA expression of genes involved in the response to cold stress and homeoviscous adaptation (HSP70, HSP90a, HSP90b, CIRP and SCD). Sturgeon were sampled after 1 day and 1 week following stocking into temperatures of 8, 6 and 4°C in a controlled laboratory environment. The southern population showed lower condition and higher mortality during early life than the northern population while increased rearing temperature impacted the growth and condition of developing northern sturgeon. During the cold shock, HSP70 and HSP90a mRNA expression increased in all sturgeon treatments as stocking temperature decreased, with higher expression observed in the southern population. Expression of HSP90b, CIRP and SCD increased as stocking temperature decreased in northern sturgeon with early acclimation to 20°C. Correlation analyses indicated the strongest molecular relationships were in the expression of HSP90b, CIRP and SCD, across all treatments, with a correlation between HSP90b and body condition in northern sturgeon with early acclimation to 20°C. Together, these observations highlight the importance of population and rearing environment throughout early development and on later cellular responses induced by cold stocking temperatures.

Blood Will Tell: What Hematological Analyses Can Reveal About Fish Welfare

Blood analyses provide substantial information about the physiological aspects of animal welfare assessment, including the activation status of the neuroendocrine and immune system, acute and long-term impacts due to adverse husbandry conditions, potential diseases, and genetic predispositions. However, fish blood is still not routinely analyzed in research or aquaculture for the assessment of health and/or welfare. Over the years, the investigative techniques have evolved from antibody-based or PCR-based single-parameter analyses to now include transcriptomic, metabolomic, and proteomic approaches and from hematological observations to fluorescence-activated blood cell sorting in high-throughput modes. The range of testing techniques established for blood is now broader than for any other biogenic test material. Evaluation of the particular characteristics of fish blood, such as its cell composition, the nucleation of distinct blood cells, or the multiple isoforms of certain immune factors, requires adapted protocols and careful attention to the experimental designs and interpretation of the data. Analyses of fish blood can provide an integrated picture of the endocrine, immunological, reproductive, and genetic functions under defined environmental conditions and treatments. Therefore, the scarcity of high-throughput approaches using fish blood as a test material for fish physiology studies is surprising. This review summarizes the wide range of techniques that allow monitoring of informative fish blood parameters that are modulated by different stressors, conditions, and/or treatments. We provide a compact overview of several simple plasma tests and of multiparametric analyses of fish blood, and we discuss their potential use in the assessment of fish welfare and pathologies.

Transcriptome analysis reveals molecular mechanisms responsive to acute cold stress in the tropical stenothermal fish tiger barb (Puntius tetrazona)

BACKGROUND

Tropical stenothermal fish exhibit special tolerance and response to cold stress. However current knowledge of the molecular mechanisms response to cold stress in aquatic ectotherms is largely drawn from eurythermal or extreme stenothermal species. The tiger barb Puntius tetrazona is a tropical stenothermal fish, with great popularity in aquarium trade and research.

RESULTS

To investigate the response mechanism of P. tetrazona to low temperature, fish were exposed to increasing levels of acute cold stress. Histopathological analysis showed that the brain, gill, liver and muscle tissues appeared serious damage after cold stress (13 °C). Brain, gill, liver and muscle tissues from control (CTRL) groups (27 °C) and COLD stress groups (13 °C) of eight-month fish (gender-neutral) were sampled and assessed for transcriptomic profiling by high-throughput sequencing. 83.0 Gb of raw data were generated, filtered and assembled for de novo transcriptome assembly. According to the transcriptome reference, we obtained 392,878 transcripts and 238,878 unigenes, of which 89.29% of the latter were annotated. There were 23,743 differently expressed genes (DEGs) been filtered from four pairs of tissues (brain, gill, liver and muscle) between these cold stress and control groups. These DEGs were mainly involved in circadian entrainment, circadian rhythm, biosynthesis of steroid and fatty acid. There were 64 shared DEGs between the four pairs of groups, and five were related to ubiquitylation/deubiquitylation. Our results suggested that ubiquitin-mediated protein degradation might be necessary for tropical stenothermal fish coping with acute cold stress. Also, the significant cold-induced expression of heat shock 70 kDa protein (HSP70) and cold-induced RNA-binding protein (CIRBP) was verified. These results suggested that the expression of the molecular chaperones HSP70 and CIRBP in P. tetrazona might play a critical role in coping with acute cold stress.

CONCLUSIONS

This is the first transcriptome analysis of P. tetrazona using RNA-Seq technology. Novel findings about tropical stenothermal fish under cold stress (such as HSP70 and CIRBP genes) are presented here. This study contributes new insights into the molecular mechanisms of tropical stenothermal species response to acute cold stress.

Evaluation of heat stress effects on cellular and transcriptional adaptation of bovine granulosa cells

Background

Heat stress is known to affect follicular dynamics, oocyte maturation, and fertilization by impairing steroidogenic ability and viability of bovine granulosa cell (bGCs). The present study explored the physiological and molecular response of bGCs to different heat stress intensities in-vitro. We exposed the primary bGCs to heat stress (HS) at 39 °C, 40 °C and 41 °C along with control samples (38 °C) for 2 h. To evaluate the impact of heat stress on bGCs, several in vitro cellular parameters including cell apoptosis, intracellular reactive oxygen species (ROS) accumulation and HSP70 kinetics were assessed by flow cytometry, florescence microscopy and western blot, respectively. Furthermore, the ELISA was performed to confirm the 17β-estradiol (E₂) and progesterone (P₄) levels. In addition, the RNA sequencing (RNA-Seq) method was used to get the molecular based response of bGCs to different heat treatments.

Results

Our findings revealed that the HS significantly decreased the cell viability, E₂ and P₄ levels in bGCs, whereas, increased the cellular apoptosis and ROS. Moreover, the RNA-Seq experiments showed that all the treatments (39 °C, 40 °C and 41 °C) significantly regulated many differentially expressed genes (DEGs) i.e. BCL2L1, STAR, CYP11A1, CASP3, SOD2, HSPA13, and MAPK8IP1 and pathways associated with heat stress, apoptosis, steroidogenesis, and oxidative stress. Conclusively, our data demonstrated that the impact of 40 °C treatment was comparatively detrimental for cell viability, apoptosis and ROS accumulation. Notably, a similar trend of gene expression was reported by RT-qPCR for RNA-seq data.

Conclusions

Our study presented a worthy strategy for the first time to characterize the cellular and transcriptomic adaptation of bGCs to heat stress (39, 40 and 41 °C) in-vitro. The results infer that these genes and pathways reported in present study could be useful candidates/indicators for heat stress research in dairy cattle. Moreover, the established model of bGCs to heat stress in the current study provides an appropriate platform to understand the mechanism of how heat-stressed bGCs can affect the quality of oocytes and developing embryo.

Cellular and Molecular Adaptation of Bovine Granulosa Cells and Oocytes under Heat Stress

Simple Summary

Heat stress can have large effects on most aspects of reproductive function in dairy cows. A hot environment can increase blood, rectal, and uterine temperatures, alter ovarian folliculogenesis, suppress fertility, oogenesis, and embryogenesis and ultimately reduce conception and pregnancy rates. Among the components of the female reproductive tract, the ovarian pool of follicles and their enclosed granulosa cells and oocytes are highly sensitive to hyperthermia. Many effects of elevated temperature on granulosa cells and developing oocytes involve increased production of reactive oxygen species, subsequently induce cellular apoptosis, and decrease the developmental ability of oocytes to be fertilized. Furthermore, heat stress-associated reproductive disorders are associated with altered progesterone and reduced estradiol production by ovarian follicles. The review mainly focuses on the follicle-enclosed granulosa cells and oocytes, provides new insights into the cellular and molecular adaptations of granulosa cells and oocyte under heat stress, depicts the role of the follicle microenvironment, and discusses some mechanisms that might underlie oocyte impairment. This study provides a possible way for the genetic adaptation to heat stress both for the regulation of body temperature and cellular resistance to elevated temperature.

Abstract

Heat stress has long been recognized as a challenging issue that severely influences the reproductive functions of dairy cattle, disrupting oocyte development during fetal growth. These detrimental effects of heat stress are the result of either the hyperthermia associated with heat stress or the physiological adjustments made by the heat-stressed animal to regulate body temperature. In addition, elevated temperatures have been implicated in increasing the production of reactive oxygen species. Thus, understanding the impact of heat stress on reproductive functions, from a cellular to molecular level, might help in selecting heat-resilient dairy cattle and developing heat stress mitigation strategies. In the present paper, we have attempted to describe the changes in the reproductive system and function of dairy cattle in response to heat stress by reviewing the latest literature in this area. The review provides useful knowledge on the cellular and genetic basis of oocyte and granulosa cells in heat-stressed dairy cattle, which could be helpful for future research in this area.

Selenium for the mitigation of toxicity induced by lead in chicken testes through regulating mRNA expressions of HSPs and selenoproteins

Lead (Pb) is a toxic element and environmental pollutant. Pb toxicity and antagonistic effect of selenium (Se) on Pb have been deeply studied in mammals. The testis is one of the target organs of Pb in birds. The aim of this study was to investigate the mitigating effect of Se on Pb toxicity in chicken testes by determining messenger RNA (mRNA) expressions of 5 heat shock proteins (HSPs) and 25 selenoproteins. Sixty male chickens (7-day-old) were randomly divided into the control group, the Se group, the Pb group, and the Pb + Se group, and were fed for 90 days. The feeding methods of chickens were as follows: The control group was fed drinking water and commercial diet (0.49 mg/kg Se). Lead acetate was added into the drinking water (350 mg/L Pb). Sodium selenite was added into the commercial diet (1 mg/kg Se). Multivariate correlation analysis and principal component analysis (PCA) were used to define the relationships among all the measured factors and the most important parameters that could be used as key factors, respectively. The results indicated that Se decreased the increase of mRNA expressions of all the HSPs and increased the decrease of mRNA expressions of all the selenoproteins induced by Pb in the chicken testes. HSP70 may be a biomarker of Pb poisoning in the chicken testes. Se alleviated Pb-induced toxicity in the chicken testes through regulating mRNA expressions of HSPs and selenoproteins.

Molecular characterization and expression analysis of Hsp90 in Schizothorax prenanti

Aquatic animals suffer from various environmental stresses because the aquatic environment is a very complex system. To monitor the health status of fish, Hsp90 a potential early warning marker was determined in Schizothorax prenanti after infection with a bacterium. In this study, we cloned Hsp90 from S. prenanti for the first time. The full-length cDNA sequence of SpHsp90 was 2663 bp, contains an open reading frame of 2181 bp, and has a gene encoding 726 amino acids, an estimated molecular mass of 83.38 kDa, and a theoretical isoelectric point of 4.91. The SpHsp90 amino acid sequence has five conserved HSP90 family signatures and shares 87.0-95.5 % identity with other vertebrates. Phylogenetic analysis and structure comparison indicated that SpHsp90 should be a β isoform of the HSP90 family. SpHsp90 was ubiquitously expressed in all examined tissues, and the highest level of expression was in the kidney. After Streptococcus agalactiae infection, the level of SpHsp90 expression had significant changes (P < 0.05) in the hepatopancreas, spleen, kidney, and blood. The expression increased to the highest level at 6 h in the blood and at 24 h in the hepatopancreas, spleen, and kidney. The results suggested that the SpHsp90 gene could be induced by S. agalactiae in S. prenanti and that SpHsp90 may be involved in resistance to bacterial infection and provide an early warning information. The kidney is the most suitable for detecting SpHsp90 after bacterial infection.

Impact of Heat Stress on Cellular and Transcriptional Adaptation of Mammary Epithelial Cells in Riverine Buffalo (Bubalus Bubalis)

The present study aims to identify the heat responsive genes and biological pathways in heat stressed buffalo mammary epithelial cells (MECs). The primary mammary epithelial cells of riverine buffalo were exposed to thermal stress at 42°C for one hour. The cells were subsequently allowed to recover at 37°C and harvested at different time intervals (30 min to 48 h) along with control samples (un-stressed). In order to assess the impact of heat stress in buffalo MECs, several in-vitro cellular parameters (lactate dehydrogenase activity, cell proliferation assay, cellular viability, cell death and apoptosis) and transcriptional studies were conducted. The heat stress resulted in overall decrease in cell viability and cell proliferation of MECs while induction of cellular apoptosis and necrosis. The transcriptomic profile of heat stressed MECs was generated using Agilent 44 K bovine oligonucleotide array and at cutoff criteria of ≥3-or ≤3 fold change, a total of 153 genes were observed to be upregulated while 8 genes were down regulated across all time points post heat stress. The genes that were specifically up-regulated or down-regulated were identified as heat responsive genes. The upregulated genes in heat stressed MECs belonged to heat shock family viz., HSPA6, HSPB8, DNAJB2, HSPA1A. Along with HSPs, genes like BOLA, MRPL55, PFKFB3, PSMC2, ENDODD1, ARID5A, and SENP3 were also upregulated. Microarray data revealed that the heat responsive genes belonged to different functional classes viz., chaperons; immune responsive; cell proliferation and metabolism related. Gene ontology analysis revealed enrichment of several biological processes like; cellular process, metabolic process, response to stimulus, biological regulation, immune system processes and signaling. The transcriptome analysis data was further validated by RT-qPCR studies. Several HSP (HSP40, HSP60, HSP70, HSP90, and HSPB1), apoptotic (Bax and Bcl2), immune (IL6, TNFα and NF-kβ) and oxidative stress (GPX1 and DUSP1) related genes showed differential expression profile at different time points post heat stress. The transcriptional data strongly indicated the induction of survival/apoptotic mechanism in heat stressed buffalo MECs. The overrepresented pathways across all time points were; electron transport chain, cytochrome P450, apoptosis, MAPK, FAS and stress induction of HSP regulation, delta Notch signaling, apoptosis modulation by HSP70, EGFR1 signaling, cytokines and inflammatory response, oxidative stress, TNF-alpha and NF- kB signaling pathway. The study thus identified several genes from different functional classes and biological pathways that could be termed as heat responsive in buffalo MEC. The responsiveness of buffalo MECs to heat stress in the present study clearly suggested its suitability as a model to understand the modulation of buffalo mammary gland expression signature in response to environmental heat load.

Immunotoxicological effects of cadmium on Labeo rohita, with emphasis on the expression of HSP genes

The present study evaluated the effects of exposure (28 days) to a sub-lethal concentration of cadmium (Cd) (0.65 mg CdCl2 L(-1)) on the immune responses and expression of immune-related and heat shock protein (HSP) genes in Labeo rohita, an important aquacultured fish species. Among the immune parameters studied, significantly lower lysozyme activity was observed in fish 28 days post-exposure (dpe) to Cd as compared to control fish. Alternative complement pathway activity was slightly higher in the Cd-exposed group at 2 dpe than in controls, and this activity declined gradually thereafter. The phagocytic activity and serum immunoglobulin M (IgM) levels were insignificantly lower in the Cd-exposed group at all assessed time points than in controls. Among serum enzymatic activities, peroxidase activity was always higher in the Cd-exposed group than in controls, but the increase was insignificant at all assessed time points. Additionally, serum glutamic-pyruvic transaminase and alkaline phosphatase activities were significantly higher in the Cd-exposed group at 14 and 28 dpe. Immune and HSP gene expression patterns were observed in kidney and liver tissues, respectively, by RT-PCR, and HSPs were further analysed by immunoblotting. Cd had an immunosuppressive effect, leading to down-regulation of TNF-α, IL-1β, IL-10, and IFN-γ. However, Cd exposure led to the up-regulation of HSP47, HSP60, HSP70, HSP78, and HSP90, indicating Cd-induced cellular stress. Taken together, the results of this study demonstrate the immunotoxic effect of Cd. Cd exposure makes Labeo rohita immunocompromised, and this could subsequently increase the disease susceptibility of Labeo rohita.

Nutritional mitigation of winter thermal stress in gilthead seabream: Associated metabolic pathways and potential indicators of nutritional state

A trial was carried out with gilthead seabream juveniles, aiming to investigate the ability of an enhanced dietary formulation (diet Winter Feed, WF, containing a higher proportion of marine-derived protein sources and supplemented in phospholipids, vitamin C, vitamin E and taurine) to assist fish in coping with winter thermal stress, compared to a low-cost commercial diet (diet CTRL). In order to identify the metabolic pathways affected by WF diet, a comparative two dimensional differential in-gel electrophoresis (2D-DIGE) analysis of fish liver proteome (pH 4–7) was undertaken at the end of winter. A total of 404 protein spots, out of 1637 detected, were differentially expressed between the two groups of fish. Mass spectrometry analysis of selected spots suggested that WF diet improved oxidative stress defense, reduced endoplasmic reticulum stress, enhanced metabolic flux through methionine cycle and phenylalanine/tyrosine catabolism, and induced higher aerobic metabolism and gluconeogenesis. Results support the notion that WF diet had a positive effect on fish nutritional state by partially counteracting the effect of thermal stress and underlined the sensitivity of proteome data for nutritional and metabolic profiling purposes. Intragroup variability and co-measured information were also used to pinpoint which proteins displayed a stronger relation with fish nutritional state.

SIGNIFICANCE

Winter low water temperature is a critical factor for gilthead seabream farming in the Mediterranean region, leading to a reduction of feed intake, which often results in metabolic and immunological disorders and stagnation of growth performances. In a recent trial, we investigated the ability of an enhanced dietary formulation (diet WF) to assist gilthead seabream in coping with winter thermal stress, compared to a standard commercial diet (diet CTRL). Within this context, in the present work, we identified metabolic processes that are involved in the stress-mitigating effect observed with diet WF, by undertaking a comparative analysis of fish liver proteome at the end of winter. This study brings information relative to biological processes that are involved in gilthead seabream winter thermal stress and shows that these can be mitigated through a nutritional strategy, assisting gilthead seabream to deal better with winter thermal conditions. Furthermore, the results show that proteomic information not only clearly distinguishes the two dietary groups from each other, but also captures heterogeneities that reflect intra-group differences in nutritional state. This was exploited in this work to refine the variable selection strategy so that protein spots displaying a stronger correlation with “nutritional state” could be identified as possible indicators of gilthead seabream metabolic and nutritional state. Finally, this study shows that gel-based proteomics seems to provide more reliable information than transmissive FT-IR spectroscopy, for the purposes of nutritional and metabolic profiling.

Effects of Molybdenum or/and Cadmium on mRNA Expression Levels of Inflammatory Cytokines and HSPs in Duck Spleens

Cadmium (Cd) and high dietary intake of molybdenum (Mo) can cause multiple-organ injury in animals, but the co-induced toxicity of Mo and Cd to spleen in ducks is not well understood. The aim of this study was to investigate the co-induced effects of Mo and Cd on the mRNA expression levels of inflammatory cytokines and heat shock proteins (HSPs) in duck spleens. Two hundred forty healthy 11-day-old ducks were randomly divided into six groups and treated with a commercial diet containing Mo or/and Cd. After being treated with Mo or/and Cd for 30, 60, 90, and 120 days, the mRNA expression levels of nuclear factor-kappa B (NF-κB), tumor necrosis factor-α (TNF-α), cyclooxygenase-2 (COX-2), HSP60, HSP70, and HSP90 were examined in duck spleens. Histopathology was examined in duck spleens at 120 days. The results indicated that the mRNA expression levels of HSPs were significantly upregulated in the co-induced groups (P < 0.01), while these decreased in the high dietary intake of Mo combined with Cd group at 120 days. Exposure to Mo or/and Cd upregulated the mRNA expression levels of NF-κB, COX-2, and TNF-α in the combination groups (P < 0.01). Furthermore, severe congestion, bleeding, splenic corpuscle structure fuzzy, wall thickness of sheath artery thickening, and oxyhematin were observed in the spleens of combination groups. Meanwhile, the organizational structure damage of the combined groups was more severe than that of the other groups. These results suggested that exposure to Mo or/and Cd might lead to tissue damage, and high expression of HSPs and inflammatory cytokines may play a role in the resistance of spleen toxicity induced by Mo or/and Cd. Interaction of Mo and Cd may have a synergistic effect on spleen toxicity.

Skin mucus proteome map of European sea bass (Dicentrarchus labrax)

Skin mucus is the first barrier of fish defence. Proteins from skin mucus of European sea bass (Dicentrarchus labrax) were identified by 2DE followed by LC-MS/MS. From all the identified proteins in the proteome map, we focus on the proteins associated with several immune pathways in fish. Furthermore, the real-time PCR transcript levels in skin are shown. Proteins found include apolipoprotein A1, calmodulin, complement C3, fucose-binding lectin, lysozyme and several caspases. To our knowledge, this is the first skin mucus proteome study and further transcriptional profiling of the identified proteins done on this bony fish species. This not only contributes knowledge on the routes involved in mucosal innate immunity, but also establishes a non-invasive technique based on locating immune markers with a potential use for prevention and/or diagnosis of fish diseases.

Skin immune response in the zebrafish, Danio rerio (Hamilton), to Aeromonas hydrophila infection: a transcriptional profiling approach

Skin plays an important role in innate immune responses to bacterial infection, but its molecular mechanism remains unclear in fish. The transcriptional profiling of the skin immune response to Aeromonas hydrophila infection of the zebrafish, Danio rerio (Hamilton), was performed by Affymetrix microarray analysis. The results showed that 538 genes were differentially expressed, of which 388 genes were up-regulated and 150 genes were down-regulated. The expression patterns for 106 representative genes were observed to be up-regulated in zebrafish skin at 24 and 36 h post-infection, and gene expression changes were clearly greater at 36 h. Gene Ontology classification indicated that 222 genes were significantly associated with the skin immunity, including complement activation, acute-phase response, stress response, chemotaxis and apoptosis. Further Kyoto Encyclopedia of Genes and Genomes analysis showed that the significant pathways included MAPK, p53, Wnt, TGF-β, Notch, ErbB, JAK-STAT, VEGF, mTOR and Calcium signalling in skin immune responses, and several genes (e.g. akt2l, frap1, nras, rac1, xiap) were found to be involved in signalling networks. Moreover, expression changes in nine selected genes were verified by real-time qPCR analysis. This is the first known report on transcriptome analysis in the skin of zebrafish against the pathogen A. hydrophila.

Role of HSP70 in cytoplasm protection against thermal stress in rohu, Labeo rohita

To understand the function of HSP70 of Labeo rohita (LrHSP70) in cellular protection, LrHSP70 ORF cDNA was inserted into the plasmid of pET-32a(+) or pEGFP-L1. Then, the recombinant plasmids were transformed or transfected into Escherichia coli cells, mouse myeloma cells (MPC-11) or fish hepatoma cells (PLHC-1). Western blot results revealed that LrHSP70 was expressed in E. coli cells and molecular weight was estimated to be 70 kDa. In cells, LrHSP70 was over-expressed following thermal or cold stress. Results revealed that LrHSP70 protected prokaryotic cells against thermal or cold extremes as well as played the same role in MPC-11 and PLHC-1 cells. After heat treatment at 42 °C for 1 h, the viability of the cell was declined considerably. PLHC-1 cells with pEGFP-L1/LrHSP70 exhibited a higher survival rate (50%) than wild-type cells (18%) or cells with only pEGFP-L1 (21.2%). When the time lag extended to 2 h, the survival rates were 30%, 3.4% and 5.3% respectively. The present study revealed that LrHSP70 plays an important role in response to thermal and cold stress in fish.

Expression of heat shock protein 90 genes during early development and infection in Megalobrama amblycephala and evidence for adaptive evolution in teleost

Heat shock protein 90 (HSP90) are highly conserved molecular chaperones, playing a pivotal role in cellular progress. In this study, we reported the characterization of the Hsp90α and Hsp90β genes in Megalobrama amblycephala, the expression profiling during early development, in various healthy tissues and in response to bacterial infection, and the assessment of their adaptive evolution. The Hsp90α cDNA contains an open reading frame (ORF) of 2193 bp encoding 731 amino acids and the Hsp90β cDNA has an ORF of 2184 bp encoding 728 amino acids. Using quantitative real-time PCR (qRT-PCR) analysis, the mRNA of both Hsp90α and Hsp90β reached the highest level at 15th day post-hatch. Using qRT-PCR and Western blot, both Hsp90α and Hsp90β were widely expressed in various healthy tissues and significantly higher in blood than in other tissues. Expression of both Hsp90α and Hsp90β were up-regulated upon bacterial infection and reached the peak level at 4 h post infection. Site model analysis indicated that one positive selection site (T717) in Hsp90α was found, while no positive selection site was observed in Hsp90β. Branch-site model test showed that there were adaptively evolutionary evidences in the branches of Salmoniformes and Gasterosteiformes for Hsp90α gene, and in the branch of Salmoniformes for Hsp90β gene.