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Vatanparast M, Esmaeily M, Stanley D, Kim Y. A PLA2 deletion mutant using CRISPR/Cas9 coupled to RNASeq reveals insect immune genes associated with eicosanoid signaling. PLoS One 2024; 19:e0304958. [PMID: 39018338 PMCID: PMC11253937 DOI: 10.1371/journal.pone.0304958] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2024] [Accepted: 05/21/2024] [Indexed: 07/19/2024] Open
Abstract
Eicosanoids mediate insect immune responses and synthesized by the catalytic activity of phospholipase A2 (PLA2). A uniquely encoded secretory PLA2 (sPLA2) is associated with immune responses of a lepidopteran insect, Spodoptera exigua. Its deletion mutant was generated using a CRISPR/Cas9 genome editing technology. Both wild and mutant lines were then immune-challenged, and the resulting transcripts were compared with their naïve transcripts by RNASeq using the Illumina-HiSeq platform. In total, 12,878 unigenes were further analyzed by differentially expressed gene tools. Over 69% of the expressed genes in S. exigua larvae are modulated in their expression levels by eicosanoids, recorded from CRISPR/Cas9 mutagenesis against an eicosanoid-synthetic gene, Se-sPLA2. Further, about 36% of the immune-associated genes are controlled by the eicosanoids in S. exigua. Indeed, the deletion mutant suffered significant immunosuppression in both cellular and humoral responses in response to bacterial challenge as well as severely reduced developmental and reproductive potentials.
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Affiliation(s)
- Mohammad Vatanparast
- Department of Plant Medicals, Andong National University, Andong, Korea
- Federal Research Centre for Cultivated Plants, Epigenetics and RNAi Lab, Institute for Biosafety in Plant Biotechnology, Julius Kühn Institute (JKI), Quedlinburg, Germany
| | - Mojtaba Esmaeily
- Department of Plant Medicals, Andong National University, Andong, Korea
| | - David Stanley
- USDA/Agricultural Research Service, Biological Control of Insects Research Laboratory, Columbia, MO, United States of America
| | - Yonggyun Kim
- Department of Plant Medicals, Andong National University, Andong, Korea
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2
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Esmaeily M, Kim Y. Four phospholipase A 2 genes encoded in the western flower thrips genome and their functional differentiation in mediating development and immunity. Sci Rep 2024; 14:9766. [PMID: 38684777 PMCID: PMC11059263 DOI: 10.1038/s41598-024-60522-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2023] [Accepted: 04/24/2024] [Indexed: 05/02/2024] Open
Abstract
Eicosanoids are synthesized from phospholipids by the catalytic activity of phospholipase A2 (PLA2). Even though several PLA2s are encoded in the genome of different insect species, their physiological functions are not clearly discriminated. This study identified four PLA2 genes encoded in the western flower thrips, Frankliniella occidentalis. Two PLA2s (Fo-PLA2C and Fo-PLA2D) are predicted to be secretory while the other two PLA2s (Fo-PLA2A and Fo-PLA2B) are intracellular. All four PLA2 genes were expressed in all developmental stages, of which Fo-PLA2B and Fo-PLA2C were highly expressed in larvae while Fo-PLA2A and Fo-PLA2D were highly expressed in adults. Their expressions in different tissues were also detected by fluorescence in situ hybridization. All four PLA2s were detected in the larval and adult intestines and the ovary. Feeding double-stranded RNAs specific to the PLA2 genes specifically suppressed the target transcript levels. Individual RNA interference (RNAi) treatments led to significant developmental retardation, especially in the treatments specific to Fo-PLA2B and Fo-PLA2D. The RNAi treatments also showed that Fo-PLA2B and Fo-PLA2C expressions were required for the induction of immune-associated genes, while Fo-PLA2A and Fo-PLA2D expressions were required for ovary development. These results suggest that four PLA2s are associated with different physiological processes by their unique catalytic activities and expression patterns.
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Affiliation(s)
- Mojtaba Esmaeily
- Department of Plant Medicals, College of Life Sciences, Andong National University, Andong, 36729, Korea
| | - Yonggyun Kim
- Department of Plant Medicals, College of Life Sciences, Andong National University, Andong, 36729, Korea.
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3
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Yu CW, Yen PL, How CM, Kuo YH, Hsiu-Chuan Liao V. Early-life long-term ibuprofen exposure reduces reproductive capacity involved in spermatogenesis impairment and associated with the transcription factor DAF-5 in Caenorhabditis elegans. CHEMOSPHERE 2024; 347:140717. [PMID: 37979808 DOI: 10.1016/j.chemosphere.2023.140717] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Revised: 10/16/2023] [Accepted: 11/12/2023] [Indexed: 11/20/2023]
Abstract
Pharmaceuticals and personal care products (PPCPs) are emerging environmental contaminants and have raised significant concern due to their potential adverse impact on the environment. Ibuprofen is one of the most extensively used non-steroidal anti-inflammatory drugs (NSAIDs) and is also considered an environmental contaminant. The negative impact of ibuprofen on non-target organisms has been documented; however, the molecular mechanisms behind its reproductive toxicity remain unclear. We investigated the impact of early-life long-term ibuprofen exposure on reproductive capacity and its involvement of spermiogenesis in the non-target model organism Caenorhabditis elegans. Hermaphrodites were exposed to various ibuprofen concentrations (0.1, 1, 10, and 100 mg/L), resulting in a dose-dependent inhibition of reproduction. In addition, the lowest observed adverse effect concentration (LOAEC) for ibuprofen exposure on the total brood size of C. elegans was 0.1 mg/L, a concentration that falls within the environmentally relevant range for ibuprofen. Outcross progeny assays revealed a significant 47% reduction in total brood size for larval males (him-5) exposed to ibuprofen, while females (fog-2) exhibited only a minor effect. We found that early-life long-term ibuprofen exposure impairs spermatogenesis. The number of mitotic cells significantly reduced by 31%. The rate of sperm malformation in exposed males was 63%, much higher than in unexposed males (11%). Additionally, the percentage of sperm activation decreased from 89% to 39% in ibuprofen-exposed worms. Mechanistic insights indicated that ibuprofen downregulated mRNA levels of genes related to spermatogenesis and DAF-7/TGF-β signaling. RNAi assays provided evidence for the crucial role of the transcription factor DAF-5 in mediating the spermatogenesis impairment by ibuprofen. Our study provides insight into the environmental impacts of pharmaceutical contaminants, such as ibuprofen, on both male and female reproductive systems to safeguard environmental health.
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Affiliation(s)
- Chan-Wei Yu
- Department of Bioenvironmental Systems Engineering, National Taiwan University, No. 1, Section 4, Roosevelt Road, Taipei, 106, Taiwan
| | - Pei-Ling Yen
- Department of Bioenvironmental Systems Engineering, National Taiwan University, No. 1, Section 4, Roosevelt Road, Taipei, 106, Taiwan
| | - Chun Ming How
- Department of Bioenvironmental Systems Engineering, National Taiwan University, No. 1, Section 4, Roosevelt Road, Taipei, 106, Taiwan
| | - Yu-Hsuan Kuo
- Department of Bioenvironmental Systems Engineering, National Taiwan University, No. 1, Section 4, Roosevelt Road, Taipei, 106, Taiwan
| | - Vivian Hsiu-Chuan Liao
- Department of Bioenvironmental Systems Engineering, National Taiwan University, No. 1, Section 4, Roosevelt Road, Taipei, 106, Taiwan.
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Choi DY, Kim Y. Prostaglandin E 2 mediates chorion formation of the Asian tiger mosquito, Aedes albopictus, at late oogenesis. INSECT MOLECULAR BIOLOGY 2023; 32:484-509. [PMID: 37158315 DOI: 10.1111/imb.12846] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Accepted: 04/25/2023] [Indexed: 05/10/2023]
Abstract
Chorion-i.e., the eggshell-is formed during the late stage of oogenesis by follicular epithelium in the ovary. Although the endocrine signal(s) driving choriogenesis remain unclear in mosquitoes, this process in other insects has been suspected to involve the mediation of prostaglandins (PGs). This study tested the role of PG in the choriogenesis of the Asian tiger mosquito, Aedes albopictus, and its influence on controlling the expressions of genes associated with chorion formation by a transcriptome analysis. An immunofluorescence assay showed that PGE2 is localised in follicular epithelium. With the treatment of aspirin, an inhibitor of PG biosynthesis, at mid oogenesis, the PGE2 signal disappeared in the follicular epithelium led to significantly inhibited chorion formation along with a malformed eggshell. Ovary transcriptomes were assessed by RNASeq at the mid and late ovarian developmental stages. Differentially expressed genes (DEGs) exhibiting more than twofold changes in expression levels included 297 genes at mid stage and 500 genes at late stage. These DEGs at these two developmental stages commonly included genes associated with egg and chorion proteins of Ae. albopictus. Most chorion-associated genes were clustered in the 168 Mb region on a chromosome and exhibited significantly induced expressions at both ovarian developmental stages. The inhibition of PG biosynthesis significantly suppressed the expression of the chorion-associated genes while the addition of PGE2 rescued the gene expressions and led to recovery of choriogenesis. These results suggest that PGE2 mediates the choriogenesis of Ae. albopictus.
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Affiliation(s)
- Du-Yeol Choi
- Department of Plant Medicals, College of Life Sciences, Andong National University, Andong, South Korea
| | - Yonggyun Kim
- Department of Plant Medicals, College of Life Sciences, Andong National University, Andong, South Korea
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Choi DY, Kim Y. PGE 2 mediation of egg development in Western flower thrip, Frankliniella occidentalis. ARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY 2023; 112:e21949. [PMID: 35749583 DOI: 10.1002/arch.21949] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Revised: 06/07/2022] [Accepted: 06/08/2022] [Indexed: 06/15/2023]
Abstract
Eicosanoids mediate various insect physiological processes, including reproduction. Especially, the eicosanoid prostaglandin E2 (PGE2 ) is known to mediate oocyte development in some insects. The explosive reproductive potential of the Western flower thrips, Frankliniella occidentalis, damages various agricultural crops. However, little is known about the underlying physiological processes of egg development in this pest. This study found that treatment with aspirin (ASP) (a specific cyclooxygenase (COX) inhibitor) used to inhibit PGE2 biosynthesis during ovarian development significantly suppressed the reproduction of female F. occidentalis. However, the addition of PGE2 to ASP-treated females significantly rescued the suppressed reproduction. PGE2 was detected in growing ovarian follicles in an immunofluorescence assay. The hypothetical biosynthetic machinery of PGE2 was predicted from the F. occidentalis genome and included phospholipase A2 (PLA2 ), COX-like peroxidase (POX), and PGE2 synthase (PGES). Three specific PLA2 s were highly expressed in female adults during active oogenesis. Specific POX and PGES genes also showed high expression during active oogenesis. The adverse effect of ASP treatment on oogenesis was observed in follicle formation in the germarium where the follicle numbers in an ovariole were decreased, which resulted in hypotrophied ovaries. This impairment was rescued by the addition of PGE2 . ASP treatment also significantly inhibited chorion formation and suppressed gene expression associated with choriogenesis, which included chorion protein, mucin, and yellow while it did not inhibit vitellogenin gene expression. However, the addition of PGE2 induced the expression of the target genes suppressed by ASP treatment and rescued chorion formation. These results suggest that PGE2 mediated ovarian development by affecting follicle formation and choriogenesis in F. occidentalis.
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Affiliation(s)
- Du-Yeol Choi
- Department of Plant Medicals, College of Life Sciences, Andong National University, Andong, Korea
| | - Yonggyun Kim
- Department of Plant Medicals, College of Life Sciences, Andong National University, Andong, Korea
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Aspirin Inhibition of Prostaglandin Synthesis Impairs Mosquito Egg Development. Cells 2022; 11:cells11244092. [PMID: 36552860 PMCID: PMC9776805 DOI: 10.3390/cells11244092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2022] [Revised: 12/08/2022] [Accepted: 12/14/2022] [Indexed: 12/24/2022] Open
Abstract
Several endocrine signals mediate mosquito egg development, including 20-hydroxyecdysone (20E). This study reports on prostaglandin E2 (PGE2) as an additional, but core, mediator of oogenesis in a human disease-vectoring mosquito, Aedes albopictus. Injection of aspirin (an inhibitor of cyclooxygenase (COX)) after blood-feeding (BF) inhibited oogenesis by preventing nurse cell dumping into a growing oocyte. The inhibitory effect was rescued by PGE2 addition. PGE2 was found to be rich in nurse cells and follicular epithelium after BF. RNA interference (RNAi) treatments of PG biosynthetic genes, including PLA2 and two COX-like peroxidases, prevented egg development. Interestingly, 20E treatment significantly increased the expressions of PG biosynthetic genes, while the RNAi of Shade (which is a 20E biosynthetic gene) expression prevented inducible expressions after BF. Furthermore, RNAi treatments of PGE2 receptor genes suppressed egg production, even under PGE2. These results suggest that a signaling pathway of BF-20E-PGE2 is required for early vitellogenesis in the mosquito.
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Al Baki MA, Chandra Roy M, Lee DH, Stanley D, Kim Y. The prostanoids, thromboxanes, mediate hemocytic immunity to bacterial infection in the lepidopteran Spodoptera exigua. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2021; 120:104069. [PMID: 33737116 DOI: 10.1016/j.dci.2021.104069] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Revised: 03/04/2021] [Accepted: 03/06/2021] [Indexed: 06/12/2023]
Abstract
We report on a new insect prostanoid in a lepidopteran insect, Spodoptera exigua. Thromboxane B2 (TXB2) was detected by LC-MS/MS in extracts of larval epidermis, midgut, fat body and hemocytes, with highest amounts in hemocytes (about 300 ng/g tissue with substantial variation). Thromboxane A2 (TXA2) is an unstable intermediate that is non-enzymatically hydrolyzed into the stable TXB2. In S. exigua, both thromboxanes mediate at least two cellular immune responses to bacterial infection, hemocyte-spreading behavior and nodule formation. At the molecular level, a TXA2 synthase (SeTXAS) was identified from a group of 139 S. exigua cytochrome P450 monooxygenases. SeTXAS was highly similar to mammalian TXAS genes and is expressed in all developmental stages and four tested larval tissues. Immune challenge significantly enhanced SeTXAS expression, especially in hemocytes. RNA interference (RNAi) injections using gene-specific double stranded RNA led to reduced SeTXAS expression and suppressed the cellular immune responses, which were rescued following TXA2 or TXB2 injections. Unlike other PGs, TXA2 or TXB2 did not influence oocyte development in adult females. We infer that thromboxanes are present in insect tissues, where they mediate innate immune responses.
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Affiliation(s)
- Md Abdullah Al Baki
- Department of Plant Medicals, College of Life Sciences, Andong National University, Andong, 36729, South Korea
| | - Miltan Chandra Roy
- Department of Plant Medicals, College of Life Sciences, Andong National University, Andong, 36729, South Korea
| | - Dong-Hee Lee
- Industry Academy Cooperation Foundation, Andong National University, Andong, 36729, South Korea
| | - David Stanley
- Biological Control of Insect Research Laboratory, USDA/ARS, 1503 South Providence Road, Columbia, MO, 65203, USA
| | - Yonggyun Kim
- Department of Plant Medicals, College of Life Sciences, Andong National University, Andong, 36729, South Korea.
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Ahmed S, Al Baki MA, Lee J, Seo DY, Lee D, Kim Y. The first report of prostacyclin and its physiological roles in insects. Gen Comp Endocrinol 2021; 301:113659. [PMID: 33166533 DOI: 10.1016/j.ygcen.2020.113659] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 11/03/2020] [Accepted: 11/04/2020] [Indexed: 12/13/2022]
Abstract
Prostaglandins (PGs) mediate physiological processes of insects as well as mammals. Prostaglandin I2 (PGI2) is a relatively well-known eicosanoid with potent hormone-like actions on various tissues of vertebrates, however, its presence and biosynthetic pathway have not been described in insects. This study demonstrated that fat bodies of the lepidopteran species, Spodoptera exigua, contained ~ 3.6 pg/g PGI2. To identify its biosynthetic pathway, a PGI2 synthase gene of S. exigua (Se-PGIS) was predicted from a transcriptome of S. exigua; 25.6% homology with human PGIS was demonstrated. Furthermore, a predicted three-dimensional structure of Se-PGIS was demonstrated to be 38.3% similar to the human PGIS ortholog, including catalytic residues. Se-PGIS was expressed in all developmental stages of S. exigua and most abundant larval and adult stages; immune challenging of larvae significantly up-regulated these expression levels. The inducible expression of Se-PGIS expression was followed by a greater than four-fold increase in the concentration of PGI2 in fat bodies 10 h after immune challenge. RNA interference (RNAi) against Se-PGIS was performed by injecting double-stranded RNA (dsRNA). Under these RNAi conditions, cellular immune responses (e.g., hemocyte-spreading behavior, nodulation, phenoloxidase activity) were not affected by bacterial challenge. The addition of PGI2 to larvae treated with an eicosanoid biosynthesis inhibitor did not rescue the immunosuppression. Interestingly, PGI2 injection significantly suppressed nodule formation in response to bacterial challenge. In addition to the negative effect of PGI2 against immunity, the Se-PGIS-RNAi treatment significantly interfered with immature development and severely impaired oocyte development in female adults; the addition of PGI2 to RNAi-treated females significantly recovered oocyte development. Se-PGIS RNAi treatment also impaired male fertility by reducing fecundity after mating with untreated females. These results suggest that PGI2 acts as a negative regulator of immune responses initiated by other factors and mediates S. exigua development and reproduction.
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Affiliation(s)
- Shabbir Ahmed
- Department of Plant Medicals, Andong National University, Andong 36729, Republic of Korea
| | - Md Abdullah Al Baki
- Department of Plant Medicals, Andong National University, Andong 36729, Republic of Korea
| | - Junbeom Lee
- Metabolomics Research Center for Functional Materials, Kyungsung University, Busan 48434, Republic of Korea
| | - Dong Yeon Seo
- Metabolomics Research Center for Functional Materials, Kyungsung University, Busan 48434, Republic of Korea
| | - Daeweon Lee
- Metabolomics Research Center for Functional Materials, Kyungsung University, Busan 48434, Republic of Korea; Department of Biology, Kyungsung University, Busan 48434, Republic of Korea
| | - Yonggyun Kim
- Department of Plant Medicals, Andong National University, Andong 36729, Republic of Korea.
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Ahmed S, Seo K, Kim Y. An ovary-specific mucin is associated with choriogenesis mediated by prostaglandin signaling in Spodoptera exigua. ARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY 2021; 106:e21748. [PMID: 33038048 DOI: 10.1002/arch.21748] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 09/26/2020] [Accepted: 09/27/2020] [Indexed: 06/11/2023]
Abstract
Polytrophic ovarioles of Spodoptera exigua, a lepidopteran insect, begins with the development of oocytes and differentiation of nurse cells followed by vitellogenesis and choriogenesis. Compared with previtellogenic and vitellogenic developments, choriogenesis has not been clearly understood yet in endocrine control. This study investigated the expression and function of a mucin-like structural protein of S. exigua called Se-Mucin1 in choriogenesis. It was highly expressed in ovarioles containing chorionated oocytes. The expression level of Se-Mucin1 was increased during adult stage as early as 18 h after adult emergence, reaching the maximal level at 24 h and later. Interestingly, DNA amount of Se-Mucin1 was increased by almost four folds during early adult stage while other genes (hexokinase and glyceraldehyde-3-phosphate dehydrogenase) not directly associated with chorion formation did not show genomic DNA increase, suggesting specific gene amplification of Se-Mucin1. RNA interference (RNAi) suppressed Se-Mucin1 expression by injecting 1 μg of double-strand RNA to teneral females (<5 h after emergence), which exhibited significantly impaired fecundity and egg hatching rate. Eggs laid by RNAi-treated females were malformed in eggshell structures with loss of mesh-like fibers. Treatment with aspirin, a prostaglandin (PG) biosynthesis inhibitor, suppressed the induction of Se-Mucin1 expression during early adult stage and impaired egg development. An addition of PGE2 significantly rescued such impairment in Se-Mucin1 expression and subsequent egg development. These results suggest that PGs mediate choriogenesis of S. exigua by activating the expression of chorion-associated genes including Se-Mucin1.
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Affiliation(s)
- Shabbir Ahmed
- Department of Plant Medicals, Andong National University, Andong, Korea
| | - Kiwon Seo
- Department of Plant Medicals, Andong National University, Andong, Korea
| | - Yonggyun Kim
- Department of Plant Medicals, Andong National University, Andong, Korea
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Ahmed S, Kim Y. Prostaglandin catabolism in Spodoptera exigua, a lepidopteran insect. J Exp Biol 2020; 223:jeb233221. [PMID: 32978320 DOI: 10.1242/jeb.233221] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Accepted: 09/18/2020] [Indexed: 08/25/2023]
Abstract
Several prostaglandins (PGs) and PG-synthesizing enzymes have been identified from insects. PGs mediate cellular and humoral immune responses. However, uncontrolled and prolonged immune responses might have adverse effects on survival. PG catabolism in insects has not been reported. Here, using a transcriptomic analysis, we predicted the presence of two PG-degrading enzymes, PG dehydrogenase (SePGDH) and PG reductase (SePGR), in Spodoptera exigua, a lepidopteran insect. SePGDH and SePGR expression levels were upregulated after immune challenge. However, their expression peaks occurred after those of PG biosynthesis genes, such as those encoding PGE2 synthase or PGD2 synthase. SePGDH and SePGR expression levels were upregulated after injection with PGE2 or PGD2 In contrast, such upregulated expression was not detected after injection with leukotriene B4, an eicosanoid inflammatory mediator. RNA interference (RNAi) using double-stranded RNAs specific to SePGDH or SePGR suppressed their expression levels. The RNAi treatment resulted in an excessive and fatal melanization of larvae even after a non-pathogenic bacterial infection. Phenoloxidase (PO) activity mediating the melanization in larval plasma was induced by bacterial challenge or PGE2 injection. Although the induced PO activity decreased after 8 h in control larvae, those treated with dsRNAs specific to PG-degrading enzyme genes kept a high PO activity for a longer period. These results suggest that SePGDH and SePGR are responsible for PG degradation at a late phase of the immune response.
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Affiliation(s)
- Shabbir Ahmed
- Department of Plant Medicals, Andong National University, Andong 36729, Korea
| | - Yonggyun Kim
- Department of Plant Medicals, Andong National University, Andong 36729, Korea
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Kim Y, Ahmed S, Al Baki MA, Kumar S, Kim K, Park Y, Stanley D. Deletion mutant of PGE 2 receptor using CRISPR-Cas9 exhibits larval immunosuppression and adult infertility in a lepidopteran insect, Spodoptera exigua. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2020; 111:103743. [PMID: 32464135 DOI: 10.1016/j.dci.2020.103743] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2020] [Revised: 05/06/2020] [Accepted: 05/08/2020] [Indexed: 06/11/2023]
Abstract
Prostaglandins (PGs) mediate various physiological processes in insects and other invertebrates, but there is very little information on PG receptors. This study identified a PGE2 receptor (SePGE2R) in the lepidopteran insect, Spodoptera exigua, and addressed its functional association with cellular immunity, development, and reproduction. SePGE2R is expressed in most developmental stages and tissues. After SePGR2R expression knock down by RNA interference (RNAi), larval nodule formation (clears bacterial infections from circulating hemolymph) was severely suppressed coupled with reduced F-actin growth in hemocytes. Treating female adults with RNAi prevented nurse cell dumping in follicles and interfered with oocyte development. SePGE2R was heterologously expressed in Sf9 cells, in which the endogenous S. frugiperda PGE2R was knocked down by small interfering RNA. This transiently expressed SePGE2R responded to PGE2, but not other PGs, with dose-dependent up-regulation of intracellular cAMP concentrations. Treating S. exigua larvae with PGE2 led to activation of a trimeric Gαs subunit, protein kinase A (PKA), and Rho family small intracellular G proteins in hemocytes. A deletion mutant of SePGE2R was generated using CRISPR/Cas9 which exhibited severely retarded larval development and adult reproduction. We infer that PGE2R mediates insect immune and reproductive processes via a PKA signal pathway.
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Affiliation(s)
- Yonggyun Kim
- Department of Plant Medicals, College of Life Sciences, Andong National University, Andong 36729, South Korea.
| | - Shabbir Ahmed
- Department of Plant Medicals, College of Life Sciences, Andong National University, Andong 36729, South Korea
| | - Md Abdullah Al Baki
- Department of Plant Medicals, College of Life Sciences, Andong National University, Andong 36729, South Korea
| | - Sunil Kumar
- Department of Plant Medicals, College of Life Sciences, Andong National University, Andong 36729, South Korea; Department of Biological Sciences, Sungkyunkwan University, Suwon, 440-746, South Korea
| | - Kunwoo Kim
- Department of Plant Medicals, College of Life Sciences, Andong National University, Andong 36729, South Korea
| | - Youngjin Park
- Department of Plant Medicals, College of Life Sciences, Andong National University, Andong 36729, South Korea; Plant Quarantine Technology Center, Animal and Plant Quarantine Agency, Gimcheon, 39660, South Korea
| | - David Stanley
- Biological Control of Insect Research Laboratory, USDA/Agricultural Research Service, Colombia, MO, USA
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Stanley D, Goodman CL, Ringbauer JA, Song Q. Prostaglandins influence protein phosphorylation in established insect cell line. ARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY 2020; 105:e21725. [PMID: 32681680 DOI: 10.1002/arch.21725] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Revised: 07/01/2020] [Accepted: 07/03/2020] [Indexed: 06/11/2023]
Abstract
Prostaglandins (PGs) are oxygenated metabolites of arachidonic acid and two other C20 polyunsaturated fatty acids. Among other actions in invertebrates, PGs act in ovarian development, renal functions, immunity, hemocyte migration, and gene/protein expression. Reversible phosphorylation is a major mechanism of regulating protein functions in eukaryotic cells and for some mammalian proteins it is influenced by PGs. We posed the hypothesis that PGs influence protein phosphorylation within insect cells, which we tested with the established insect cell line, BCIRL-HzAM1. After 20, 30, or 40 min incubations in the presence of one of three PGs (at 15 μM), PGA2 , PGE1 , or PGF2α , separate sets of cells were processed for analysis by two-dimensional electrophoresis followed by tandem mass spectrometry. We recorded significant phosphorylation changes in 31 proteins, decreases in 15, and increases in 15, and one protein with increased or decreased phosphorylation, depending on PG treatment. Increasing PG exposure times led to changes in fewer proteins, 20 min incubations led to changes in 16 proteins, 30 min to changes in 13, and 40 min to changes in 2 proteins. The proteins were identified by bioinformatic analyses, including transcript description, calculated molecular weights and isoelectric points, MOlecular Weight SEarch score, total ion score, numbers of peptides, percent protein coverage, E-value, and highest peptide score. The data presented in this paper firmly support our hypothesis that PGs influence protein phosphorylation within insect cells and adds a novel PG-signaled function to insect biology.
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Affiliation(s)
- David Stanley
- Biological Control of Insects Research Laboratory, United States Department of Agriculture, Agricultural Research Service, Columbia, Missouri
| | - Cynthia L Goodman
- Biological Control of Insects Research Laboratory, United States Department of Agriculture, Agricultural Research Service, Columbia, Missouri
| | - Joseph A Ringbauer
- Biological Control of Insects Research Laboratory, United States Department of Agriculture, Agricultural Research Service, Columbia, Missouri
| | - Qisheng Song
- Division of Plant Sciences, University of Missouri, Columbia, Missouri
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Sajjadian SM, Ahmed S, Al Baki MA, Kim Y. Prostaglandin D 2 synthase and its functional association with immune and reproductive processes in a lepidopteran insect, Spodoptera exigua. Gen Comp Endocrinol 2020; 287:113352. [PMID: 31794733 DOI: 10.1016/j.ygcen.2019.113352] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Revised: 11/29/2019] [Accepted: 11/29/2019] [Indexed: 12/21/2022]
Abstract
Several prostaglandins (PGs) have been identified in different insect species. However, their biosynthesis and physiological roles in insects remain unclear. PGD2 is synthesized by isomerization from PGH2 in mammals. This study identified a PGD2 synthase (SePGDS) in a lepidopteran insect, Spodoptera exigua. It showed sequence homology (32.8%) with human PGDS. Based on its conserved active site residues, its N-terminal tyrosine (Y8) was predicted to mediate electron relay from glutathione to PGH2 substrate, which was distinct from the catalysis of PGE2 (=PGD2 isomer) synthase (SePGES). SePGDS was highly expressed in larval and adult stages. RNA interference (RNAi) of SePGDS expression resulted in immunosuppression of cellular immune responses by suppressing the expression of actin polymerization-associated genes. It also suppressed the expression of some antimicrobial genes. Such immunosuppression induced by RNAi treatment was specifically rescued by the addition of PGD2, but not its precursor, arachidonic acid. Such RNAi treatment in adults prevented egg development in females by inhibiting choriogenesis. RNAi treatment also suppressed nurse cell dumping to growing oocytes. However, the addition of PGD2 rescued egg development of RNAi-treated females. These results suggest that SePGDS is responsible for the production of PGD2 which mediates immune and reproductive processes of S. exigua.
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Affiliation(s)
- Seyede Minoo Sajjadian
- Department of Plant Medicals, Andong National University, Andong 36729, Republic of Korea
| | - Shabbir Ahmed
- Department of Plant Medicals, Andong National University, Andong 36729, Republic of Korea
| | - Md Abdullah Al Baki
- Department of Plant Medicals, Andong National University, Andong 36729, Republic of Korea
| | - Yonggyun Kim
- Department of Plant Medicals, Andong National University, Andong 36729, Republic of Korea.
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Md Abdullah AB, Lee DW, Jung J, Kim Y. Deletion mutant of sPLA 2 using CRISPR/Cas9 exhibits immunosuppression, developmental retardation, and failure of oocyte development in legume pod borer, Maruca vitrata. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2020; 103:103500. [PMID: 31589887 DOI: 10.1016/j.dci.2019.103500] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Revised: 09/24/2019] [Accepted: 09/24/2019] [Indexed: 06/10/2023]
Abstract
Phospholipase A2 (PLA2) catalyzes release of free fatty acids linked to phospholipids at sn-2 position. Some of these released free fatty acids are used to synthesize eicosanoids that mediate various physiological processes in insects. Although a large number of PLA2s form a superfamily consisting of at least 16 groups, few PLA2s have been identified and characterized in insects. Furthermore, physiological functions of insect PLA2s remain unclear. Clustered regularly interspaced short parlindromic repeats/CRISPR-associated protein 9 (CRISPR/Cas9) has been a useful research tool to validate gene function. This study identified and characterized a secretory PLA2 (sPLA2) from legume pod borer, Maruca vitrata (Lepidoptera: Crambidae), and validated its physiological functions using CRISPR/Cas9. An open reading frame of M. vitrata sPLA2 (Mv-sPLA2) encoding 192 amino acids contained signal peptide, calcium-binding domain, and catalytic site. Phylogenetic analysis indicated that Mv-sPLA2 was related to other Group III sPLA2s. Mv-sPLA2 was expressed in both larval and adult stages. It was inducible by immune challenge. RNA interference (RNAi) of Mv-sPLA2 significantly suppressed cellular immunity and impaired larval development. Furthermore, RNAi treatment in female adults prevented oocyte development. These physiological alterations were also observed in a mutant line of M. vitrata with Mv-sPLA2 deleted by using CRISPR/Cas9. Mv-sPLA2 was not detected in the mutant line from western blot analysis. Addition of an eicosanoid, PGE2, significantly rescued oocyte development of females of the mutant line. These results suggest that Mv-sPLA2 plays crucial role in immune, developmental, and reproductive processes of M. vitrata.
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Affiliation(s)
- Al Baki Md Abdullah
- Department of Plant Medicals, Andong National University, Andong, 36729, South Korea
| | - Dae-Weon Lee
- School of Chemistry and Life Sciences, Kyungsung University, Busan, 48434, South Korea
| | - Jinkyo Jung
- Division of Crop Cultivation and Environment Research, Department of Central Area Crop Science, National Institute of Crop Science, Rural Development Administration, Suwon, 16429, South Korea
| | - Yonggyun Kim
- Department of Plant Medicals, Andong National University, Andong, 36729, South Korea.
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Ahmed S, Kim Y. PGE 2 mediates cytoskeletal rearrangement of hemocytes via Cdc42, a small G protein, to activate actin-remodeling factors in Spodoptera exigua (Lepidoptera: Noctuidae). ARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY 2019; 102:e21607. [PMID: 31338878 DOI: 10.1002/arch.21607] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Revised: 07/09/2019] [Accepted: 07/10/2019] [Indexed: 06/10/2023]
Abstract
Prostaglandin E2 (PGE2 ) mediates cellular immune responses in insects by stimulating hemocyte-spreading behavior that is driven by actin remodeling to form filopodial or lamellipodial cytoplasmic extensions. In Spodoptera exigua (Lepidoptera: Noctuidae), Cdc42, a small G protein, played a crucial role in mediating PGE2 signal on hemocyte-spreading behavior. Hemocyte-spreading behavior requires actin cytoskeletal rearrangement. A plethora of actin-related proteins have been predicted to have functional links with Cdc42. Here, we selected four actin-associated genes (Actin-related protein 2 [Arp2], Profilin, Cofilin, and Fascin) and evaluated their influences on cytoskeletal rearrangement in S. exigua. Bioinformatic analysis confirmed their gene identities. Transcript analysis using reverse-transcription polymerase chain reaction indicated that all four actin-associated genes were expressed in most developmental stages, showing high expression levels in larval hemocytes. RNA interference (RNAi) against these genes was performed by injecting double-stranded RNA (dsRNA) to hemocoel. Under RNAi condition, the hemocyte-spreading behavior was significantly impaired except for dsRNA treatment against Cofilin, an actin-depolymerizing factor. Alteration of cytoskeletal rearrangement appeared to vary after different RNAi treatments. RNAi against Arp2 markedly suppressed lamellipodial extension while RNAi against Profilin or Fascin adversely influenced filopodial extension. RNAi of these actin-associated factors prevented cellular immune responses measured by nodule formation against bacterial challenge. Under RNAi conditions, addition of PGE2 did not well induce hemocyte-spreading behavior, suggesting that these actin-associated factors might act downstream of the hormone signaling pathway. These results suggest that PGE2 can mediate hemocyte-spreading behavior via Cdc42 to activate downstream actin polymerization/branching/bundling factors, thus inducing actin cytoskeletal rearrangement.
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Affiliation(s)
- Shabbir Ahmed
- Department of Plant Medicals, College of Life Sciences, Andong National University, Andong, Korea
| | - Yonggyun Kim
- Department of Plant Medicals, College of Life Sciences, Andong National University, Andong, Korea
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Hasan MA, Ahmed S, Kim Y. Biosynthetic pathway of arachidonic acid in Spodoptera exigua in response to bacterial challenge. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2019; 111:103179. [PMID: 31255640 DOI: 10.1016/j.ibmb.2019.103179] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2019] [Revised: 06/24/2019] [Accepted: 06/24/2019] [Indexed: 06/09/2023]
Abstract
Eicosanoids play crucial roles in mediating insect immune responses. In vertebrates, phospholipase A2 (PLA2) releases arachidonic acid (AA) from phospholipids (PLs) for biosynthesis of various eicosanoids. However, little AA is found in PLs of lepidopteran insects. Spodoptera exigua, a lepidopteran insect, is known to use eicosanoids to mediate immunity. Although AA was not detected in PLs of hemocytes and fat body (two immune tissues) of naïve larvae, it was detected at small but significant level after bacterial infection, suggesting induction of AA biosynthesis for immunity. Based on a mammalian AA biosynthetic pathway, this study hypothesizes that AA is synthesized from C18 polyunsaturated fatty acid (PUFA) precursor by subsequent desaturation and elongation reactions because PLs of S. exigua larvae are rich in linoleic acid. After inhibiting PLA2 activity to prevent release of free fatty acids, different PUFA precursors were injected to S. exigua larvae followed by assessment of eicosanoid-mediated cellular immune response. ω-6 PUFAs were effective in inducing immune response whereas α-linolenic acid (an ω-3 PUFA) was not. Several fatty acyl desaturases (SeDESs) have been predicted from S. exigua transcriptomes. Specific inhibitors against Δ5 or Δ6 DESs inhibited eicosanoid-mediated immune responses. Furthermore, RNA interference (RNAi) specific to Δ5 or Δ6 DES genes significantly suppressed eicosanoid-mediated immune responses. Four very long chain fatty acid elongase genes (SeEloV-A ∼ SeEloV-D) were predicted. Among respective RNAi treatments of these genes, only one RNAi treatment specific to type 5 elongase (SeEloV-B) suppressed eicosanoid-mediated immune response. These results suggest that S. exigua larvae can synthesize AA from linoleic acid via Δ5- and Δ6-desaturations by SeDESs along with chain elongation by SeEloV-B. Finally, this study showed significant fitness cost of uncontrolled AA biosynthesis. AA injection alone without bacterial challenge significantly induced both cellular and humoral immune responses. This unnecessary energy expense due to free AA resulted in reduced pupal size and decreased adult egg production. The detrimental effect of free AA explains physiological significance of little AA content in lepidopteran insects except for life-or-death situation such as pathogen infection.
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Affiliation(s)
- Md Ariful Hasan
- Department of Plant Medicals, College of Life Sciences, Andong National University, Andong, 36729, South Korea
| | - Shabbir Ahmed
- Department of Plant Medicals, College of Life Sciences, Andong National University, Andong, 36729, South Korea
| | - Yonggyun Kim
- Department of Plant Medicals, College of Life Sciences, Andong National University, Andong, 36729, South Korea.
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