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Hu Y, Ma X, Liu R, Mushtaq I, Qi Y, Yuan C, Huang D. 2,4-Dichlorophenol Increases Primordial Germ Cell Numbers via ESR2a-Dependent Pathway in Zebrafish Larvae. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:13878-13887. [PMID: 36106461 DOI: 10.1021/acs.est.2c05212] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Previous studies have reported the feminizing effects of 2,4-dichlorophenol (2,4-DCP) on zebrafish (Danio rerio). However, the effect of 2,4-DCP on the number of primordial germ cells (PGCs), an indicator for early sex differentiation, remains elusive. In the present study, Tg (piwil1:egfp-UTR nanos3) zebrafish (GFP-labeled PGCs) were treated with 2,4-DCP (10, 20, and 40 μg/L) from 5 to 15 days postfertilization to explore the effect on PGC numbers and to elucidate associated molecular mechanisms. The results showed that 2,4-DCP exposure increased PGC numbers, as evidenced by larger GFP fluorescent areas, upregulated expressions of PGC marker genes (vasa and dnd), and raised the female ratio. Notably, the mRNA level of estrogen receptor 2a (esr2a) was also increased subsequently. Moreover, docking studies revealed stable 2,4-DCP interactions with ESR2a, speculating a role of ESR2a signaling pathway in 2,4-DCP toxicity. Furthermore, in esr2a knockout (esr2a-/-) zebrafish, the effects of 2,4-DCP were considerably minimized, proving the involvement of the ESR2a signaling pathway in the 2,4-DCP-mediated increase in PGC numbers. Dual-luciferase reporter gene assay and point mutation studies demonstrated that 2,4-DCP-stimulated promoter activity was mediated by estrogen response element (ERE) located in -686/-674 of the vasa promoter and -731/-719 of the dnd promoter. Overall, 2,4-DCP can potentially enhance the expression of vasa and dnd by binding to zebrafish ESR2a, thus leading to increased PGC numbers and subsequent female-biased sex differentiation.
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Affiliation(s)
- Yan Hu
- Gansu Key Laboratory of Biomonitoring and Bioremediation for Environmental Pollution, School of Life Sciences, Lanzhou University, Lanzhou 730000, People's Republic of China
| | - Xuan Ma
- Gansu Key Laboratory of Biomonitoring and Bioremediation for Environmental Pollution, School of Life Sciences, Lanzhou University, Lanzhou 730000, People's Republic of China
| | - Rongjian Liu
- Gansu Key Laboratory of Biomonitoring and Bioremediation for Environmental Pollution, School of Life Sciences, Lanzhou University, Lanzhou 730000, People's Republic of China
| | - Iqra Mushtaq
- Gansu Key Laboratory of Biomonitoring and Bioremediation for Environmental Pollution, School of Life Sciences, Lanzhou University, Lanzhou 730000, People's Republic of China
| | - Yongmei Qi
- Gansu Key Laboratory of Biomonitoring and Bioremediation for Environmental Pollution, School of Life Sciences, Lanzhou University, Lanzhou 730000, People's Republic of China
| | - Cong Yuan
- Gansu Key Laboratory of Biomonitoring and Bioremediation for Environmental Pollution, School of Life Sciences, Lanzhou University, Lanzhou 730000, People's Republic of China
| | - Dejun Huang
- Gansu Key Laboratory of Biomonitoring and Bioremediation for Environmental Pollution, School of Life Sciences, Lanzhou University, Lanzhou 730000, People's Republic of China
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Segner H, Bailey C, Tafalla C, Bo J. Immunotoxicity of Xenobiotics in Fish: A Role for the Aryl Hydrocarbon Receptor (AhR)? Int J Mol Sci 2021; 22:ijms22179460. [PMID: 34502366 PMCID: PMC8430475 DOI: 10.3390/ijms22179460] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Revised: 08/25/2021] [Accepted: 08/27/2021] [Indexed: 02/07/2023] Open
Abstract
The impact of anthropogenic contaminants on the immune system of fishes is an issue of growing concern. An important xenobiotic receptor that mediates effects of chemicals, such as halogenated aromatic hydrocarbons (HAHs) and polyaromatic hydrocarbons (PAHs), is the aryl hydrocarbon receptor (AhR). Fish toxicological research has focused on the role of this receptor in xenobiotic biotransformation as well as in causing developmental, cardiac, and reproductive toxicity. However, biomedical research has unraveled an important physiological role of the AhR in the immune system, what suggests that this receptor could be involved in immunotoxic effects of environmental contaminants. The aims of the present review are to critically discuss the available knowledge on (i) the expression and possible function of the AhR in the immune systems of teleost fishes; and (ii) the impact of AhR-activating xenobiotics on the immune systems of fish at the levels of immune gene expression, immune cell proliferation and immune cell function, immune pathology, and resistance to infectious disease. The existing information indicates that the AhR is expressed in the fish immune system, but currently, we have little understanding of its physiological role. Exposure to AhR-activating contaminants results in the modulation of numerous immune structural and functional parameters of fish. Despite the diversity of fish species studied and the experimental conditions investigated, the published findings rather uniformly point to immunosuppressive actions of xenobiotic AhR ligands in fish. These effects are often associated with increased disease susceptibility. The fact that fish populations from HAH- and PAH-contaminated environments suffer immune disturbances and elevated disease susceptibility highlights that the immunotoxic effects of AhR-activating xenobiotics bear environmental relevance.
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Affiliation(s)
- Helmut Segner
- Centre for Fish and Wildlife Health, Department of Pathobiology and Infectious Diseases, Vetsuisse Faculty, University of Bern, 3012 Bern, Switzerland
| | | | | | - Jun Bo
- Laboratory of Marine Biology and Ecology, Third Institute of Oceanography, Xiamen 361005, China
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Williams MB, Watts SA. Current basis and future directions of zebrafish nutrigenomics. GENES AND NUTRITION 2019; 14:34. [PMID: 31890052 PMCID: PMC6935144 DOI: 10.1186/s12263-019-0658-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Accepted: 12/16/2019] [Indexed: 12/19/2022]
Abstract
This review investigates the current state of nutrigenomics in the zebrafish animal models. The zebrafish animal model has been used extensively in the study of disease onset and progression and associated molecular changes. In this review, we provide a synopsis of nutrigenomics using the zebrafish animal model. Obesity and dyslipidemia studies describe the genomics of dietary-induced obesity in relation to high-fat/high-calorie diets. Inflammation and cardiovascular studies describe dietary effects on the expression of acute inflammatory markers and resulting chronic inflammatory issues including atherosclerosis. We also evaluated the genomic response to bioactive dietary compounds associated with metabolic disorders. Carbohydrate metabolism and β-cell function studies describe the impacts of high-carbohydrate dietary challenges on nutritional programming. We also report tumorigenesis in relation to dietary carcinogen exposure studies that can result in permanent genomic changes. Vitamin and mineral deficiency studies demonstrate transgenerational genomic impacts of micronutrients in the diet and temporal expression changes. Circadian rhythm studies describe the relation between metabolism and natural temporal cycles of gene expression that impacts health. Bone formation studies describe the role of dietary composition that influences bone reabsorption regulation. Finally, this review provides future directions in the use of the zebrafish model for nutrigenomic and nutrigenetic research.
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Affiliation(s)
- Michael B Williams
- Department of Biology, University of Alabama at Birmingham, Birmingham, AL 35294 USA
| | - Stephen A Watts
- Department of Biology, University of Alabama at Birmingham, Birmingham, AL 35294 USA
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Chen YY, Chan KM. Modulations of TCDD-mediated induction of zebrafish cyp1a1 and the AHR pathway by administering Cd 2+in vivo. CHEMOSPHERE 2018; 210:577-587. [PMID: 30029150 DOI: 10.1016/j.chemosphere.2018.07.032] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Revised: 07/06/2018] [Accepted: 07/07/2018] [Indexed: 06/08/2023]
Abstract
Trace metal ions such as cadmium (Cd2+) and trace organics typified by 2,3,7,8- tetrachlorodibenzo-p-dioxin (TCDD) are common co-contaminants in the environment and cause toxic effects in aquatic organisms that pose serious health risks. We studied the effects of Cd2+ on the regulation of cytochrome P450 1A1 (cyp1a1) gene-induction by TCDD using zebrafish embryos and larvae and adult zebrafish tissues. Our results showed that TCDD induced the cyp1a1 gene in all developmental stages and tissues of zebrafish, and the induction was higher in females than males. However, for the upstream genes (ahr2 and arnt2b) that mediate cyp1a1 gene induction in the zebrafish liver cell line was not induced by TCDD similar to the pattern of cyp1a1 in all investigated groups. After co-treatment with Cd2+, induction of the aryl hydrocarbon receptor pathway by TCDD was inhibited in the zebrafish larvae and the livers, intestines, kidneys and gills of adult zebrafish, but not in the embryos or brains of adult zebrafish, indicating that the toxicological effects of Cd2+ on TCDD are dependent on the developmental stages and tissue types. The present study confirms that Cd2+ blocks the TCDD-induced cyp1a1 gene in vivo but emphasizes that the effects are specific to the developmental stage, type of tissue and sex. The combined effects of Cd2+ and TCDD must be taken into consideration together with these parameters to accurately predict and assess cadmium and TCDD-induced toxicity in fish and carcinogenesis in animals in general.
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Affiliation(s)
- Ying Ying Chen
- School of Life Sciences, The Chinese University of Hong Kong, Sha Tin, Hong Kong
| | - King Ming Chan
- School of Life Sciences, The Chinese University of Hong Kong, Sha Tin, Hong Kong.
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Wolf JC, Wheeler JR. A critical review of histopathological findings associated with endocrine and non-endocrine hepatic toxicity in fish models. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2018; 197:60-78. [PMID: 29448125 DOI: 10.1016/j.aquatox.2018.01.013] [Citation(s) in RCA: 90] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Revised: 01/05/2018] [Accepted: 01/15/2018] [Indexed: 06/08/2023]
Abstract
Although frequently examined as a target organ for non-endocrine toxicity, histopathological evaluation of the liver is becoming a routine component of endocrine disruption studies that utilize various fish species as test subjects. However, the interpretation of microscopic liver findings can be challenging, especially when attempting to distinguish adverse changes associated with endocrine disrupting substances from those caused by systemic or direct hepatic toxicity. The purpose of this project was to conduct a critical assessment of the available peer-reviewed and grey literature concerning the histopathologic effects of reproductive endocrine active substances (EAS) and non-endocrine acting substances in the livers of fish models, and to determine if liver histopathology can be used to reliably distinguish endocrine from non-endocrine etiologies. The results of this review suggest that few compound-specific histopathologic liver effects have been identified, among which are estrogen agonist-induced increases in hepatocyte basophilia and proteinaceous intravascular fluid in adult male teleosts, and potentially, decreased hepatocyte basophilia in female fish exposed to substances that possess androgenic, anti-estrogenic, or aromatase inhibitory activity. This review also used published standardized methodology to assess the credibility of the histopathology data in each of the 117 articles that reported liver effects of treatment, and consequently it was determined that in only 37% of those papers were the data considered either highly credible or credible. The outcome of this work highlights the value of histopathologic liver evaluation as an investigative tool for EAS studies, and provides information that may have implications for EAS hazard assessment.
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Affiliation(s)
- Jeffrey C Wolf
- Experimental Pathology Laboratories, Inc., 45600 Terminal Drive, Sterling, VA, 20166, USA.
| | - James R Wheeler
- Dow AgroSciences, 3 B Park Square, Milton Park, Abingdon, Oxfordshire, OK14 4RN, UK.
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Baker BB, Yee JS, Meyer DN, Yang D, Baker TR. Histological and Transcriptomic Changes in Male Zebrafish Testes Due to Early Life Exposure to Low Level 2,3,7,8-Tetrachlorodibenzo-p-Dioxin. Zebrafish 2017; 13:413-23. [PMID: 27618130 DOI: 10.1089/zeb.2016.1275] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
We have shown that zebrafish (Danio rerio) are an excellent model for evaluating the link between early life stage exposure to environmental chemicals and disease in adulthood and subsequent unexposed generations. Previously, we used this model to identify transgenerational effects of dioxin (2,3,7,8-tetrachlorodibenzo-p-dioxin [TCDD]) on skeletal development, sex ratio, and reproductive capacity. Transgenerational inheritance of TCDD toxicity, notably decreased reproductive capacity, appears to be mediated through the male germ line. Thus, we examine testicular tissue for structural and gene expression changes using histology, microarray, and quantitative reverse transcription polymerase chain reaction (qRT-PCR). Histological analysis revealed decreased spermatozoa with concurrent increase in spermatogonia, and decreased germinal epithelium thickness in TCDD-exposed males compared with controls. We also identified altered expression of genes associated with testis development, steroidogenesis, spermatogenesis, hormone metabolism, and xenobiotic response. Altered genes are in pathways involving lipid metabolism, molecular transport, small molecule biochemistry, cell morphology, and metabolism of vitamins and minerals. These data will inform future investigations to elucidate the mechanism of adult-onset and transgenerational infertility due to TCDD exposure in zebrafish.
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Affiliation(s)
- Bridget B Baker
- 1 Fisheries Management, Fish, Wildlife, and Parks Division, Wisconsin Department of Natural Resources , Madison, Wisconsin
| | - Jeremiah S Yee
- 2 Molecular and Environmental Toxicology Center, University of Wisconsin-Madison , Madison, Wisconsin
| | - Danielle N Meyer
- 3 Department of Pharmacology, School of Medicine, Wayne State University , Detroit, Michigan
| | - Doris Yang
- 4 School of Pharmacy, University of Wisconsin-Madison , Madison, Wisconsin
| | - Tracie R Baker
- 2 Molecular and Environmental Toxicology Center, University of Wisconsin-Madison , Madison, Wisconsin.,3 Department of Pharmacology, School of Medicine, Wayne State University , Detroit, Michigan.,4 School of Pharmacy, University of Wisconsin-Madison , Madison, Wisconsin.,5 Institute of Environmental Health Sciences, Center for Urban Responses to Environmental Stressors, Wayne State University , Detroit, Michigan
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Kumar G, Denslow ND. Gene Expression Profiling in Fish Toxicology: A Review. REVIEWS OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2017; 241:1-38. [PMID: 27464848 DOI: 10.1007/398_2016_10] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
In this review, we present an overview of transcriptomic responses to chemical exposures in a variety of fish species. We have discussed the use of several molecular approaches such as northern blotting, differential display reverse transcription-polymerase chain reaction (DDRT-PCR), suppression subtractive hybridization (SSH), real time quantitative PCR (RT-qPCR), microarrays, and next-generation sequencing (NGS) for measuring gene expression. These techniques have been mainly used to measure the toxic effects of single compounds or simple mixtures in laboratory conditions. In addition, only few studies have been conducted to examine the biological significance of differentially expressed gene sets following chemical exposure. Therefore, future studies should focus more under field conditions using a multidisciplinary approach (genomics, proteomics and metabolomics) to understand the synergetic effects of multiple environmental stressors and to determine the functional significance of differentially expressed genes. Nevertheless, recent developments in NGS technologies and decreasing costs of sequencing holds the promise to uncover the complexity of anthropogenic impacts and biological effects in wild fish populations.
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Affiliation(s)
- Girish Kumar
- Faculty of Fisheries and Protection of Waters, South Bohemian Research Center of Aquaculture and Biodiversity of Hydrocenoses, University of South Bohemia in Ceske Budejovice, Zátiší 728/II, 389 25, Vodňany, Czech Republic.
| | - Nancy D Denslow
- Department of Physiological Sciences and Center for Environmental and Human Toxicology, University of Florida, Gainesville, FL, 32611, USA
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Ahi EP. Signalling pathways in trophic skeletal development and morphogenesis: Insights from studies on teleost fish. Dev Biol 2016; 420:11-31. [PMID: 27713057 DOI: 10.1016/j.ydbio.2016.10.003] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2016] [Revised: 10/02/2016] [Accepted: 10/03/2016] [Indexed: 12/12/2022]
Abstract
During the development of the vertebrate feeding apparatus, a variety of complicated cellular and molecular processes participate in the formation and integration of individual skeletal elements. The molecular mechanisms regulating the formation of skeletal primordia and their development into specific morphological structures are tightly controlled by a set of interconnected signalling pathways. Some of these pathways, such as Bmp, Hedgehog, Notch and Wnt, are long known for their pivotal roles in craniofacial skeletogenesis. Studies addressing the functional details of their components and downstream targets, the mechanisms of their interactions with other signals as well as their potential roles in adaptive morphological divergence, are currently attracting considerable attention. An increasing number of signalling pathways that had previously been described in different biological contexts have been shown to be important in the regulation of jaw skeletal development and morphogenesis. In this review, I provide an overview of signalling pathways involved in trophic skeletogenesis emphasizing studies of the most species-rich group of vertebrates, the teleost fish, which through their evolutionary history have undergone repeated episodes of spectacular trophic diversification.
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Affiliation(s)
- Ehsan Pashay Ahi
- Institute of Zoology, University of Graz, Universitätsplatz 2, A-8010 Graz, Austria; Institute of Life and Environmental Sciences, University of Iceland, Sturlugata 7, 101 Reykjavik, Iceland.
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Iida M, Fujii S, Uchida M, Nakamura H, Kagami Y, Agusa T, Hirano M, Bak SM, Kim EY, Iwata H. Identification of aryl hydrocarbon receptor signaling pathways altered in TCDD-treated red seabream embryos by transcriptome analysis. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2016; 177:156-170. [PMID: 27288597 DOI: 10.1016/j.aquatox.2016.05.014] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2015] [Revised: 05/16/2016] [Accepted: 05/20/2016] [Indexed: 06/06/2023]
Abstract
2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) induces a broad spectrum of toxic effects including craniofacial malformation and neural damage in fish embryos. These effects are mainly mediated by the aryl hydrocarbon receptor (AHR). However, the mode of action between TCDD-induced AHR activation and adverse outcomes is not yet understood. To provide a comprehensive picture of the AHR signaling pathway in fish embryos exposed to TCDD, red seabream (Pagrus major) embryos were treated with graded concentrations of TCDD (0.3-37nM) in seawater, or with a mixture of TCDD and 500nM CH223191, an AHR-specific antagonist. The transcriptome of red seabream embryos was analyzed using a custom-made microarray with 6000 probes specifically prepared for this species. A Jonckheere-Terpstra test was performed to screen for genes that demonstrated altered mRNA expression levels following TCDD exposure. The signals of 1217 genes (as human homologs) were significantly altered in a TCDD concentration-dependent manner (q-value<0.2). Notably, the TCDD-induced alteration in mRNA expression was alleviated by co-exposure to CH223191, suggesting that the mRNA expression level of these genes was regulated by AHR. To identify TCDD-activated pathways, the microarray data were further subjected to gene set enrichment analysis (GSEA) and functional protein-protein interaction (PPI) network analysis. GSEA demonstrated that the effects of TCDD on sets of genes involved calcium, mitogen-activated protein kinase (MAPK), actin cytoskeleton, chemokine, T cell receptor, melanoma, vascular endothelial growth factor (VEGF), axon guidance, and renal cell carcinoma signaling pathways. These results suggest the hypotheses that TCDD induces immunosuppression via the calcium, MAPK, chemokine, and T cell receptor signaling pathways, neurotoxicity via VEGF signaling, and axon guidance alterations and teratogenicity via the dysregulation of the actin cytoskeleton and melanoma and renal cell carcinoma signaling pathways. Furthermore, the PPI network analysis indicated that the adverse outcome pathways of TCDD in the embryos might be propagated through several hub genes such as cell division control protein 42, phosphoinositide-3-kinase regulatory subunit 1, and guanine nucleotide-binding proteins. Understanding these pathways potentially allows for exploring the adverse outcome pathway of the effects of TCDD on the red seabream embryos.
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Affiliation(s)
- Midori Iida
- Center for Marine Environmental Studies (CMES), Ehime University, Matsuyama, 790-8577, Japan; Computer Science and Systems Engineering, Kyusyu Institute of Technology, Iizuka, 820-0067, Japan.
| | - Satoshi Fujii
- Computer Science and Systems Engineering, Kyusyu Institute of Technology, Iizuka, 820-0067, Japan.
| | | | | | | | - Tetsuro Agusa
- Graduate School of Environmental and Symbiotic Sciences, Prefectural University of Kumamoto, Kumamoto, 862-0920, Japan.
| | - Masashi Hirano
- Center for Marine Environmental Studies (CMES), Ehime University, Matsuyama, 790-8577, Japan.
| | - Su-Min Bak
- Department of Life and Nanopharmaceutical Science and Department of Biology, Kyung Hee University, Seoul, 130-701, Korea.
| | - Eun-Young Kim
- Department of Life and Nanopharmaceutical Science and Department of Biology, Kyung Hee University, Seoul, 130-701, Korea.
| | - Hisato Iwata
- Center for Marine Environmental Studies (CMES), Ehime University, Matsuyama, 790-8577, Japan.
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Ahi EP, Steinhäuser SS, Pálsson A, Franzdóttir SR, Snorrason SS, Maier VH, Jónsson ZO. Differential expression of the aryl hydrocarbon receptor pathway associates with craniofacial polymorphism in sympatric Arctic charr. EvoDevo 2015; 6:27. [PMID: 26388986 PMCID: PMC4574265 DOI: 10.1186/s13227-015-0022-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Accepted: 09/04/2015] [Indexed: 12/03/2022] Open
Abstract
Background The developmental basis of craniofacial morphology hinges on interactions of numerous signalling systems. Extensive craniofacial variation in the polymorphic Arctic charr, a member of the salmonid family, from Lake Thingvallavatn (Iceland), offers opportunities to find and study such signalling pathways and their key regulators, thereby shedding light on the developmental pathways, and the genetics of trophic divergence. Results To identify genes involved in the craniofacial differences between benthic and limnetic Arctic charr, we used transcriptome data from different morphs, spanning early development, together with data on craniofacial expression patterns and skeletogenesis in model vertebrate species. Out of 20 genes identified, 7 showed lower gene expression in benthic than in limnetic charr morphs. We had previously identified a conserved gene network involved in extracellular matrix (ECM) organization and skeletogenesis, showing higher expression in developing craniofacial elements of benthic than in limnetic Arctic charr morphs. The present study adds a second set of genes constituting an expanded gene network with strong, benthic–limnetic differential expression. To identify putative upstream regulators, we performed knowledge-based motif enrichment analyses on the regulatory sequences of the identified genes which yielded potential binding sites for a set of known transcription factors (TFs). Of the 8 TFs that we examined using qPCR, two (Ahr2b and Ap2) were found to be differentially expressed between benthic and limnetic charr. Expression analysis of several known AhR targets indicated higher activity of the AhR pathway during craniofacial development in benthic charr morphotypes. Conclusion These results suggest a key role of the aryl hydrocarbon receptor (AhR) pathway in the observed craniofacial differences between distinct charr morphotypes. Electronic supplementary material The online version of this article (doi:10.1186/s13227-015-0022-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Ehsan Pashay Ahi
- Institute of Life and Environmental Sciences, University of Iceland, Sturlugata 7, 101 Reykjavik, Iceland
| | - Sophie S Steinhäuser
- Biomedical Center, University of Iceland, Vatnsmýrarvegur 16, 101 Reykjavik, Iceland
| | - Arnar Pálsson
- Institute of Life and Environmental Sciences, University of Iceland, Sturlugata 7, 101 Reykjavik, Iceland ; Biomedical Center, University of Iceland, Vatnsmýrarvegur 16, 101 Reykjavik, Iceland
| | - Sigrídur Rut Franzdóttir
- Institute of Life and Environmental Sciences, University of Iceland, Sturlugata 7, 101 Reykjavik, Iceland
| | - Sigurdur S Snorrason
- Institute of Life and Environmental Sciences, University of Iceland, Sturlugata 7, 101 Reykjavik, Iceland
| | - Valerie H Maier
- Institute of Life and Environmental Sciences, University of Iceland, Sturlugata 7, 101 Reykjavik, Iceland ; Biomedical Center, University of Iceland, Vatnsmýrarvegur 16, 101 Reykjavik, Iceland
| | - Zophonías O Jónsson
- Institute of Life and Environmental Sciences, University of Iceland, Sturlugata 7, 101 Reykjavik, Iceland ; Biomedical Center, University of Iceland, Vatnsmýrarvegur 16, 101 Reykjavik, Iceland
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Gene Expression Profiling and Pathway Network Analysis Predicts a Novel Antitumor Function for a Botanical-Derived Drug, PG2. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2015; 2015:917345. [PMID: 25972907 PMCID: PMC4417974 DOI: 10.1155/2015/917345] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/03/2014] [Revised: 02/16/2015] [Accepted: 03/11/2015] [Indexed: 12/20/2022]
Abstract
PG2 is a botanical drug that is mostly composed of Astragalus polysaccharides (APS). Its role in hematopoiesis and relieving cancer-related fatigue has recently been clinically investigated in cancer patients. However, systematic analyses of its functions are still limited. The aim of this study was to use microarray-based expression profiling to evaluate the quality and consistency of PG2 from three different product batches and to study biological mechanisms of PG2. An integrative molecular analysis approach has been designed to examine significant PG2-induced signatures in HL-60 leukemia cells. A quantitative analysis of gene expression signatures was conducted for PG2 by hierarchical clustering of correlation coefficients. The results showed that PG2 product batches were consistent and of high quality. These batches were also functionally equivalent to each other with regard to how they modulated the immune and hematopoietic systems. Within the PG2 signature, there were five genes associated with doxorubicin: IL-8, MDM4, BCL2, PRODH2, and BIRC5. Moreover, the combination of PG2 and doxorubicin had a synergistic effect on induced cell death in HL-60 cells. Together with the bioinformatics-based approach, gene expression profiling provided a quantitative measurement for the quality and consistency of herbal medicines and revealed new roles (e.g., immune modulation) for PG2 in cancer treatment.
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