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Awais MM, Fei S, Xia J, Feng M, Sun J. Insights into midgut cell types and their crucial role in antiviral immunity in the lepidopteran model Bombyx mori. Front Immunol 2024; 15:1349428. [PMID: 38420120 PMCID: PMC10899340 DOI: 10.3389/fimmu.2024.1349428] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2023] [Accepted: 01/18/2024] [Indexed: 03/02/2024] Open
Abstract
The midgut, a vital component of the digestive system in arthropods, serves as an interface between ingested food and the insect's physiology, playing a pivotal role in nutrient absorption and immune defense mechanisms. Distinct cell types, including columnar, enteroendocrine, goblet and regenerative cells, comprise the midgut in insects and contribute to its robust immune response. Enterocytes/columnar cells, the primary absorptive cells, facilitate the immune response through enzyme secretions, while regenerative cells play a crucial role in maintaining midgut integrity by continuously replenishing damaged cells and maintaining the continuity of the immune defense. The peritrophic membrane is vital to the insect's innate immunity, shielding the midgut from pathogens and abrasive food particles. Midgut juice, a mixture of digestive enzymes and antimicrobial factors, further contributes to the insect's immune defense, helping the insect to combat invading pathogens and regulate the midgut microbial community. The cutting-edge single-cell transcriptomics also unveiled previously unrecognized subpopulations within the insect midgut cells and elucidated the striking similarities between the gastrointestinal tracts of insects and higher mammals. Understanding the intricate interplay between midgut cell types provides valuable insights into insect immunity. This review provides a solid foundation for unraveling the complex roles of the midgut, not only in digestion but also in immunity. Moreover, this review will discuss the novel immune strategies led by the midgut employed by insects to combat invading pathogens, ultimately contributing to the broader understanding of insect physiology and defense mechanisms.
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Affiliation(s)
| | | | | | - Min Feng
- Guangdong Provincial Key Laboratory of Agro-Animal Genomics and Molecular Breeding, College of Animal Science, South China Agricultural University, Guangzhou, China
| | - Jingchen Sun
- Guangdong Provincial Key Laboratory of Agro-Animal Genomics and Molecular Breeding, College of Animal Science, South China Agricultural University, Guangzhou, China
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Liu H, Xu J, Wang L, Guo P, Tang Z, Sun X, Tang X, Wang W, Wang L, Cao Y, Xia Q, Zhao P. Serpin-1a and serpin-6 regulate the Toll pathway immune homeostasis by synergistically inhibiting the Spätzle-processing enzyme CLIP2 in silkworm, Bombyx mori. PLoS Pathog 2023; 19:e1011740. [PMID: 37851691 PMCID: PMC10629668 DOI: 10.1371/journal.ppat.1011740] [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: 06/04/2023] [Revised: 11/07/2023] [Accepted: 10/07/2023] [Indexed: 10/20/2023] Open
Abstract
The Toll receptor signaling pathway is an important innate immune response of insects to pathogen infection; its extracellular signal transduction involves serine protease cascade activation. However, excessive or constitutive activation of the Toll pathway can be detrimental. Hence, the balance between activation and inhibition of the extracellular protease cascade must be tightly regulated to achieve favorable outcomes. Previous studies have shown that serpins-serine protease inhibitors-negatively regulate insect innate immunity by inhibiting extracellular protease cascade signaling. Although the roles of serpins in insect innate immunity are well described, the physiological mechanisms underlying their synergistic effects remain poorly understand. Here, we characterize the molecular mechanism by which serpin-1a and serpin-6 synergistically maintain immune homeostasis of the silkworm Toll pathway under physiological and pathological conditions. Through in vitro biochemical assays and in vivo bioassays, we demonstrate that clip-domain serine protease 2 (CLIP2), as the Toll cascade-activating terminal protease, is responsible for processing proSpätzle1 to induce the expression of antimicrobial peptides. Further biochemical and genetic analyses indicate that constitutively expressed serpin-1a and inducible serpin-6 synergistically target CLIP2 to maintain homeostasis of the silkworm Toll pathway under physiological and pathological conditions. Taken together, this study provides new insights into the precise regulation of Toll cascade activation signals in insect innate immune responses and highlights the importance and complexity of insect immune homeostasis regulation.
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Affiliation(s)
- Huawei Liu
- Integrative Science Center of Germplasm Creation in Western China (CHONGQING) Science City, Biological Science Research Center, Southwest University, Chongqing, China
- Key Laboratory for Germplasm Creation in Upper Reaches of the Yangtze River, Ministry of Agriculture and Rural Affairs, Chongqing, China
| | - Jiahui Xu
- Integrative Science Center of Germplasm Creation in Western China (CHONGQING) Science City, Biological Science Research Center, Southwest University, Chongqing, China
| | - Luoling Wang
- Integrative Science Center of Germplasm Creation in Western China (CHONGQING) Science City, Biological Science Research Center, Southwest University, Chongqing, China
| | - Pengchao Guo
- Integrative Science Center of Germplasm Creation in Western China (CHONGQING) Science City, Biological Science Research Center, Southwest University, Chongqing, China
- Key Laboratory for Germplasm Creation in Upper Reaches of the Yangtze River, Ministry of Agriculture and Rural Affairs, Chongqing, China
| | - Zhangchen Tang
- Integrative Science Center of Germplasm Creation in Western China (CHONGQING) Science City, Biological Science Research Center, Southwest University, Chongqing, China
| | - Xiaotong Sun
- Integrative Science Center of Germplasm Creation in Western China (CHONGQING) Science City, Biological Science Research Center, Southwest University, Chongqing, China
| | - Xin Tang
- Chongqing Key Laboratory of Chinese Medicine & Health Science, Chongqing Academy of Chinese Materia Medica, Chongqing College of Traditional Chinese Medicine, Chongqing, China
| | - Wei Wang
- Integrative Science Center of Germplasm Creation in Western China (CHONGQING) Science City, Biological Science Research Center, Southwest University, Chongqing, China
- Key Laboratory for Germplasm Creation in Upper Reaches of the Yangtze River, Ministry of Agriculture and Rural Affairs, Chongqing, China
| | - Lingyan Wang
- Integrative Science Center of Germplasm Creation in Western China (CHONGQING) Science City, Biological Science Research Center, Southwest University, Chongqing, China
- Key Laboratory for Germplasm Creation in Upper Reaches of the Yangtze River, Ministry of Agriculture and Rural Affairs, Chongqing, China
| | - Yang Cao
- Integrative Science Center of Germplasm Creation in Western China (CHONGQING) Science City, Biological Science Research Center, Southwest University, Chongqing, China
- Key Laboratory for Germplasm Creation in Upper Reaches of the Yangtze River, Ministry of Agriculture and Rural Affairs, Chongqing, China
| | - Qingyou Xia
- Integrative Science Center of Germplasm Creation in Western China (CHONGQING) Science City, Biological Science Research Center, Southwest University, Chongqing, China
- Key Laboratory for Germplasm Creation in Upper Reaches of the Yangtze River, Ministry of Agriculture and Rural Affairs, Chongqing, China
| | - Ping Zhao
- Integrative Science Center of Germplasm Creation in Western China (CHONGQING) Science City, Biological Science Research Center, Southwest University, Chongqing, China
- Key Laboratory for Germplasm Creation in Upper Reaches of the Yangtze River, Ministry of Agriculture and Rural Affairs, Chongqing, China
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3
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Adaptation of Helicoverpa armigera to Soybean Peptidase Inhibitors Is Associated with the Transgenerational Upregulation of Serine Peptidases. Int J Mol Sci 2022; 23:ijms232214301. [PMID: 36430785 PMCID: PMC9693090 DOI: 10.3390/ijms232214301] [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: 10/12/2022] [Revised: 11/02/2022] [Accepted: 11/07/2022] [Indexed: 11/19/2022] Open
Abstract
Molecular phenotypes induced by environmental stimuli can be transmitted to offspring through epigenetic inheritance. Using transcriptome profiling, we show that the adaptation of Helicoverpa armigera larvae to soybean peptidase inhibitors (SPIs) is associated with large-scale gene expression changes including the upregulation of genes encoding serine peptidases in the digestive system. Furthermore, approximately 60% of the gene expression changes induced by SPIs persisted in the next generation of larvae fed on SPI-free diets including genes encoding regulatory, oxidoreductase, and protease functions. To investigate the role of epigenetic mechanisms in regulating SPI adaptation, the methylome of the digestive system of first-generation larvae (fed on a diet with and without SPIs) and of the progeny of larvae exposed to SPIs were characterized. A comparative analysis between RNA-seq and Methyl-seq data did not show a direct relationship between differentially methylated and differentially expressed genes, while trypsin and chymotrypsin genes were unmethylated in all treatments. Rather, DNA methylation potential epialleles were associated with transcriptional and translational controls; these may play a regulatory role in the adaptation of H. armigera to SPIs. Altogether, our findings provided insight into the mechanisms of insect adaptation to plant antiherbivore defense proteins and illustrated how large-scale transcriptional reprograming of insect genes can be transmitted across generations.
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Xu X, Wang Y, Chen J, Du X, Yao L, Xu J, Zhang Y, Huang Y, Wang Y. Mutation of Serine protease 1 Induces Male Sterility in Bombyx mori. Front Physiol 2022; 13:828859. [PMID: 35222089 PMCID: PMC8867212 DOI: 10.3389/fphys.2022.828859] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2021] [Accepted: 01/17/2022] [Indexed: 01/19/2023] Open
Abstract
Serine proteases are important in reproduction, embryonic development, cell differentiation, apoptosis, and immunity. The genes encoding some serine proteases are essential for male fertility in both humans and rodents and are functionally conserved among metazoan. For example, the Serine protease 1 (Ser1) gene determines male reproductive success in the model lepidopteran insect Bombyx mori. In this study, we explored the function of BmSer1 through transgenic CRISPR/Cas9 technology-mediated mutations in silkworm. We found that the mutation of BmSer1 gene resulted in male sterility but had no effect on female fertility. Male mutants produce normal eupyrene sperm bundles, but the sperm bundles do not dissociate into single sperm. Male sterility caused by the BmSer1 gene mutation was inherited stably through female individuals. Therefore, the serine protease encoded by BmSer1 is essential for male reproductive success in lepidopterans and is a potential target gene for biological reproductive regulation.
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Affiliation(s)
- Xia Xu
- Institute of Sericulture and Tea, Zhejiang Academy of Agricultural Sciences, Hangzhou, China
| | - Yaohui Wang
- Key Laboratory of Insect Developmental and Evolutionary Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
| | - Jine Chen
- Institute of Sericulture and Tea, Zhejiang Academy of Agricultural Sciences, Hangzhou, China
| | - Xin Du
- Institute of Sericulture and Tea, Zhejiang Academy of Agricultural Sciences, Hangzhou, China
| | - Lusong Yao
- Institute of Sericulture and Tea, Zhejiang Academy of Agricultural Sciences, Hangzhou, China
| | - Jun Xu
- Institute of Sericulture and Tea, Zhejiang Academy of Agricultural Sciences, Hangzhou, China
| | - Yong Zhang
- Key Laboratory of Insect Developmental and Evolutionary Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
| | - Yongping Huang
- Key Laboratory of Insect Developmental and Evolutionary Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
- *Correspondence: Yongping Huang,
| | - Yongqiang Wang
- Institute of Sericulture and Tea, Zhejiang Academy of Agricultural Sciences, Hangzhou, China
- Yongqiang Wang,
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Liu H, Heng J, Wang L, Li Y, Tang X, Huang X, Xia Q, Zhao P. Homeodomain proteins POU-M2, antennapedia and abdominal-B are involved in regulation of the segment-specific expression of the clip-domain serine protease gene CLIP13 in the silkworm, Bombyx mori. INSECT SCIENCE 2022; 29:111-127. [PMID: 33860633 DOI: 10.1111/1744-7917.12916] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2020] [Revised: 02/20/2021] [Accepted: 02/26/2021] [Indexed: 06/12/2023]
Abstract
Clip-domain serine proteases (CLIPs) play important roles in insect innate immunity and development. Our previous studies indicated that CLIP13, an epidermis-specific gene, was involved in cuticle remodeling during molting and metamorphosis in the silkworm, Bombyx mori. However, the transcriptional regulatory mechanism and regulatory pathways of CLIP13 remained unclear. In the present study, we investigated CLIP13 expression and the regulation pathway controlled by 20-hydroxyecdysone (20E) in the silkworm. At the transcriptional level, expression of CLIP13 exhibited pronounced spatial and temporal specificity in different regions of the epidermis; homeodomain transcription factors POU-M2, antennapedia (Antp), and abdominal-B (Abd-B) showed similar expression change trends as CLIP13 in the head capsule, thorax, and abdomen, respectively. Furthermore, results of cell transfection assays, electrophoretic mobility shift assays, and chromatin immunoprecipitation demonstrated that POU-M2, Antp, and Abd-B were involved in the transcriptional regulation of CLIP13 by directly binding to their cis-response elements in CLIP13 promoter. RNA interference-mediated silencing of POU-M2, Antp, and Abd-B led to a decrease of CLIP13 expression in the head capsule, the epidermis of the 1st to 3rd thoracic segments and the 7th to 10th abdominal segments, respectively. Consistent with CLIP13, 20E treatment significantly upregulated expression of POU-M2, Antp, and Abd-B in the silkworm epidermis. Taken together, these data suggest that 20E positively regulates transcription of CLIP13 via homeodomain proteins POU-M2, Antp, and Abd-B in different regions of the silkworm epidermis during metamorphosis, thus affecting the molting process. Our findings provide new insight into the functions of homeodomain transcription factors in insect molting.
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Affiliation(s)
- Huawei Liu
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, 400716, China
- Biological Science Research Center, Southwest University, Chongqing, 400716, China
- Chongqing Key Laboratory of Sericultural Science, Chongqing Engineering and Technology Research Center for Novel Silk Materials, Southwest University, Chongqing, 400716, China
| | - Jingya Heng
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, 400716, China
- Biological Science Research Center, Southwest University, Chongqing, 400716, China
| | - Luoling Wang
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, 400716, China
| | - Youshan Li
- College of Biological Science and Engineering, Shaanxi University of Technology, Hanzhong, Shaanxi Province, 723001, China
| | - Xin Tang
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, 400716, China
- Biological Science Research Center, Southwest University, Chongqing, 400716, China
| | - Xuan Huang
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, 400716, China
- Biological Science Research Center, Southwest University, Chongqing, 400716, China
| | - Qingyou Xia
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, 400716, China
- Biological Science Research Center, Southwest University, Chongqing, 400716, China
- Chongqing Key Laboratory of Sericultural Science, Chongqing Engineering and Technology Research Center for Novel Silk Materials, Southwest University, Chongqing, 400716, China
| | - Ping Zhao
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, 400716, China
- Biological Science Research Center, Southwest University, Chongqing, 400716, China
- Chongqing Key Laboratory of Sericultural Science, Chongqing Engineering and Technology Research Center for Novel Silk Materials, Southwest University, Chongqing, 400716, China
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6
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Zhang S, Feng T, Ji J, Wang L, An C. Serine protease SP7 cleaves prophenoloxidase and is regulated by two serpins in Ostrinia furnacalis melanization. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2022; 141:103699. [PMID: 34920078 DOI: 10.1016/j.ibmb.2021.103699] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Revised: 07/18/2021] [Accepted: 11/17/2021] [Indexed: 06/14/2023]
Abstract
Melanization is an innate immune response in insects to defend against the invading pathogens and parasites. During melanization, prophenoloxidase (PPO) requires proteolytic activation by its upstream prophenoloxidase-activating protease (PAP). We here cloned a full-length cDNA for a serine protease, named as SP7, from Ostrinia furnacalis. The open reading frame of SP7 encodes 421-amino acid residue protein with a 19-residue signal peptide. qRT-PCR analysis showed that SP7 mRNA levels were significantly upregulated upon exposure to microbial infection. Recombinant SP7 zymogen was activated by serine protease SP2. The active SP7 could cleave O. furnacalis PPOs including PPO2, PPO1b and PPO3. Additionally, active SP7 could form covalent complexes with serine protease inhibitor serpin-3 and serpin-4. The activity of SP7 in cleaving a colorimetric substrate IEARpNA or O. furnacalis PPOs was efficiently blocked by either serpin-3 or serpin-4. Our work thus revealed that SP7 and SP2 partially constituted a PPO activation cascade in which SP7 was activated by SP2 and then likely worked as a PAP. SP7 was effectively regulated by serpin-3 and serpin-4. The results would allow further advances in the understanding of melanization mechanisms in O. furnacalis.
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Affiliation(s)
- Shasha Zhang
- Department of Entomology, College of Plant Protection, China Agricultural University, Beijing, 100193, PR China
| | - Ting Feng
- Department of Entomology, College of Plant Protection, China Agricultural University, Beijing, 100193, PR China
| | - Jiayue Ji
- Department of Entomology, College of Plant Protection, China Agricultural University, Beijing, 100193, PR China
| | - Lei Wang
- Department of Entomology, College of Plant Protection, China Agricultural University, Beijing, 100193, PR China
| | - Chunju An
- Department of Entomology, College of Plant Protection, China Agricultural University, Beijing, 100193, PR China.
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7
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Zupanič N, Počič J, Leonardi A, Šribar J, Kordiš D, Križaj I. Serine pseudoproteases in physiology and disease. FEBS J 2022; 290:2263-2278. [PMID: 35032346 DOI: 10.1111/febs.16355] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Revised: 12/20/2021] [Accepted: 01/12/2022] [Indexed: 01/01/2023]
Abstract
Serine proteases (SPs) constitute a very important family of enzymes, both physiologically and pathologically. The effects produced by these proteins have been explained by their proteolytic activity. However, the discovery of pharmacologically active SP molecules that show no enzymatic activity, as the so-called pseudo SPs or SP homologs (SPHs), has exposed a profoundly neglected possibility of nonenzymatic functions of these SP molecules. In this review, the most thoroughly described SPHs are presented. The main physiological domains in which SPHs operate appear to be in reproduction, embryonic development, immune response, host defense, and hemostasis. Hitherto unexplained actions of SPs should therefore be considered also as the result of the ligand-like attributes of SPs. The gain of a novel function by an SPH is a consequence of specific amino acid replacements that have resulted in a novel interaction interface or a 'catalytic trap'. Unraveling the SP/SPH interactome will provide a description of previously unknown physiological functions of SPs/SPHs, aiding the creation of innovative medical approaches.
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Affiliation(s)
- Nina Zupanič
- Department of Molecular and Biomedical Sciences Jožef Stefan Institute Ljubljana Slovenia
| | - Jernej Počič
- Department of Molecular and Biomedical Sciences Jožef Stefan Institute Ljubljana Slovenia
- Biotechnical Faculty University of Ljubljana Slovenia
| | - Adrijana Leonardi
- Department of Molecular and Biomedical Sciences Jožef Stefan Institute Ljubljana Slovenia
| | - Jernej Šribar
- Department of Molecular and Biomedical Sciences Jožef Stefan Institute Ljubljana Slovenia
| | - Dušan Kordiš
- Department of Molecular and Biomedical Sciences Jožef Stefan Institute Ljubljana Slovenia
| | - Igor Križaj
- Department of Molecular and Biomedical Sciences Jožef Stefan Institute Ljubljana Slovenia
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Zhuang XN, Luan YY, Lv TR, Ren CM, Wang L, Li Q, Li DX. PAP1 activates the prophenoloxidase system against bacterial infection in Musca domestica. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2021; 124:104184. [PMID: 34171367 DOI: 10.1016/j.dci.2021.104184] [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: 03/27/2021] [Revised: 06/20/2021] [Accepted: 06/21/2021] [Indexed: 06/13/2023]
Abstract
We previously identified three putative prophenoloxidase-activating proteinase (mdPAP1, mdPAP2, and mdPAP3) genes from housefly Musca domestica by transcriptomic analysis. In this study, mdPAP1 cDNA was cloned, and the function of its encoded protein was analyzed. The cDNA of mdPAP1 was 1358 bp, and it contained a single open reading frame of 1122 bp encoding a predicted MdPAP1 protein of 373 amino acids. The estimated molecular weight of MdPAP1 was 41267.08 Da with an isoelectric point of 6.25. The deduced amino acid sequence of MdPAP1 exhibited high similarity to known PAPs of insects. mdPAP1 was detected in larvae, pupae, and adult housefly, and the expression level of mdPAP1 was upregulated in bacterial challenged larvae. The recombinant protein of MdPAP1 expressed in Escherichia coli could cleave the prophenoloxidase into phenoloxidase in M. domestica hemolymph infected by bacteria and result in a significant increase of the total phenoloxidase activity. In addition, RNA interference-mediated gene silencing of mdPAP1 significantly increased the mortality of M. domestica larvae. Results indicated that mdPAP1 was involved in the activation of the prophenoloxidase against bacterial infection in M. domestica.
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Affiliation(s)
- Xu-Na Zhuang
- Biotechnology Department, School of Biological Sciences and Biotechnology, University of Jinan, Jinan, 250022, China
| | - Yuan-Yuan Luan
- Biotechnology Department, School of Biological Sciences and Biotechnology, University of Jinan, Jinan, 250022, China
| | - Tong-Rui Lv
- Biotechnology Department, School of Biological Sciences and Biotechnology, University of Jinan, Jinan, 250022, China
| | - Cheng-Ming Ren
- Biotechnology Department, School of Biological Sciences and Biotechnology, University of Jinan, Jinan, 250022, China
| | - Lei Wang
- Biotechnology Department, School of Biological Sciences and Biotechnology, University of Jinan, Jinan, 250022, China
| | - Qiang Li
- Biotechnology Department, School of Biological Sciences and Biotechnology, University of Jinan, Jinan, 250022, China
| | - Dian-Xiang Li
- Biotechnology Department, School of Biological Sciences and Biotechnology, University of Jinan, Jinan, 250022, China.
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Li T, Xia Y, Xu X, Wei G, Wang L. Functional analysis of Dicer-2 gene in Bombyx mori resistance to BmNPV virus. ARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY 2020; 105:e21724. [PMID: 32623793 DOI: 10.1002/arch.21724] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2020] [Revised: 06/22/2020] [Accepted: 06/23/2020] [Indexed: 06/11/2023]
Abstract
Bombyx mori nucleopolyhedrovirus (BmNPV) is a primary pathogen in silkworm, and the molecular mechanism of B. mori defense to BmNPV infection is still unclear. RNA interference (RNAi) is well-known as an intracellular conserved mechanism that is critical in gene regulation and cell defense. The antiviral RNAi pathway processes viral double-stranded RNA (dsRNA) into viral small interfering RNAs that guide the recognition and cleavage of complementary viral target RNAs. In this study, a Dicer-2 (Dcr2) gene was identified in B. mori and its antiviral function was explored. Dcr2 messenger RNA (mRNA) expression was the highest in hemocytes and expressed in all stages of silkworm growth. After infection with BmNPV, the expression of Dcr2 mRNA was significantly increased after infection in midgut and hemocytes. The expression of Dcr2 was significantly upregulated by injecting dsRNA (dsBmSPH-1) into silkworm after 48 hr. Knocking down the expression level of Dcr2 using specific dsRNA in silkworm, which modestly enhanced the production of viral genomic DNA. Our results suggested that the Dcr2 gene in B. mori plays an important role in against BmNPV invasion.
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Affiliation(s)
- Taohong Li
- School of Life Science, Anhui Agricultural University, Hefei, China
| | - Yuchen Xia
- School of Life Science, Anhui Agricultural University, Hefei, China
| | - Xinyue Xu
- School of Life Science, Anhui Agricultural University, Hefei, China
| | - Guoqing Wei
- School of Life Science, Anhui Agricultural University, Hefei, China
| | - Lei Wang
- School of Life Science, Anhui Agricultural University, Hefei, China
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10
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Wang Q, Yin M, Yuan C, Liu X, Hu Z, Zou Z, Wang M. Identification of a Conserved Prophenoloxidase Activation Pathway in Cotton Bollworm Helicoverpa armigera. Front Immunol 2020; 11:785. [PMID: 32431706 PMCID: PMC7215089 DOI: 10.3389/fimmu.2020.00785] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Accepted: 04/07/2020] [Indexed: 01/03/2023] Open
Abstract
Melanization is a prominent insect humoral response for encapsulation of and killing invading pathogens. It is mediated by a protease cascade composed of a modular serine protease (SP), and clip domain SPs (cSPs), which converts prophenoloxidase (PPO) into active phenoloxidase (PO). To date, melanization pathway in cotton bollworm Helicoverpa armigera, an important agricultural pest, remains largely unclear. To biochemically reconstitute the pathway in vitro, the putative proteases along with modified proteases containing the factor Xa cleavage site were expressed by Drosophila S2 cell expression system. Purified recombinant proteins were used to examine their role in activating PPO. It is revealed that cascade is initiated by a modular SP-SP41, followed by cSP1 and cSP6. The three-step SP41/cSP1/cSP6 cascade could further activate PPO, and the PO activity was significantly enhanced in the presence of two cSP homologs (cSPHs), cSPH11 and cSPH50, suggesting the latter are cofactors for PPO activation. Moreover, baculovirus infection was efficiently blocked by the reconstituted PPO activation cascade, and the effect was boosted by cSPH11 and cSPH50. Taken together, we unraveled a conserved PPO activation cascade in H. armigera, which is similar to that exists in lepidopteran biochemical model Manduca sexta and highlighted its role in antagonizing viral infection.
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Affiliation(s)
- Qianran Wang
- State Key Laboratory of Virology, Center for Biosafety Mega-Science, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, China.,Savaid Medical School, University of Chinese Academy of Sciences, Beijing, China
| | - Mengyi Yin
- State Key Laboratory of Virology, Center for Biosafety Mega-Science, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, China.,Savaid Medical School, University of Chinese Academy of Sciences, Beijing, China
| | - Chuanfei Yuan
- State Key Laboratory of Virology, Center for Biosafety Mega-Science, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, China.,State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Xijia Liu
- State Key Laboratory of Virology, Center for Biosafety Mega-Science, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, China
| | - Zhihong Hu
- State Key Laboratory of Virology, Center for Biosafety Mega-Science, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, China
| | - Zhen Zou
- Savaid Medical School, University of Chinese Academy of Sciences, Beijing, China.,State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.,Key Laboratory of Tropical Translational Medicine, Laboratory of Medicine, School of Tropical Medicine, Ministry of Education, Hainan Medical University, Haikou, China
| | - Manli Wang
- State Key Laboratory of Virology, Center for Biosafety Mega-Science, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, China
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Liu H, Heng J, Wang L, Tang X, Guo P, Li Y, Xia Q, Zhao P. Identification, characterization, and expression analysis of clip-domain serine protease genes in the silkworm, Bombyx mori. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2020; 105:103584. [PMID: 31863792 DOI: 10.1016/j.dci.2019.103584] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2019] [Revised: 12/11/2019] [Accepted: 12/17/2019] [Indexed: 06/10/2023]
Abstract
Clip-domain serine proteases (CLIPs), characterized by regulatory module clip domains, constitute an important serine protease family identified in insects and other arthropods. They participate in host immune response and embryonic development in a cascade-activated manner. Here, we present a genome-wide identification and expression analysis of CLIP genes in the silkworm, Bombyx mori. A total of 26 CLIP genes were identified in the silkworm genome. Bioinformatics analysis indicated that these CLIPs clustered into four subfamilies (CLIPA-D), and exhibit a close evolutionary relationship with CLIPs of Manduca sexta. Tissue expression profiling revealed that silkworm CLIP genes are mainly expressed in the integument, head, fat body, and hemocytes. Temporal expression profiles showed that 15 CLIP genes were predominantly expressed during the fifth-instar larval stage, early and later period of the pupal stage, and adult stage, whereas 10 CLIP genes were mainly expressed in the wandering stage and middle to later period of the pupal stage in the integument. Pathogens and 20-hydroxyecdysone (20E) induction analysis indicated that 14 CLIP genes were positively regulated by 20E, 9 were negatively regulated by 20E but positively regulated by pathogens, and 5 were positively regulated by both factors in the integument. Together, these results suggested that silkworm CLIP genes may play multiple functions in integument development, including melanization of new cuticle, molting and immune defense. Our data provide a comprehensive understanding of CLIP genes in the silkworm integument and lays a foundation for further functional studies of CLIP genes in the silkworm.
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Affiliation(s)
- Huawei Liu
- Biological Science Research Center Southwest University, Chongqing, 400715, China; Chongqing Key Laboratory of Sericultural Science, Chongqing Engineering and Technology Research Center for Novel Silk Materials, Southwest University, Chongqing, 400715, China
| | - Jingya Heng
- Biological Science Research Center Southwest University, Chongqing, 400715, China
| | - Luoling Wang
- Biological Science Research Center Southwest University, Chongqing, 400715, China
| | - Xin Tang
- Biological Science Research Center Southwest University, Chongqing, 400715, China
| | - Pengchao Guo
- Biological Science Research Center Southwest University, Chongqing, 400715, China; Chongqing Key Laboratory of Sericultural Science, Chongqing Engineering and Technology Research Center for Novel Silk Materials, Southwest University, Chongqing, 400715, China
| | - Youshan Li
- College of Biological Science and Engineering, Shaanxi University of Technology, Hanzhong, 723001, Shaanxi Province, China
| | - Qingyou Xia
- Biological Science Research Center Southwest University, Chongqing, 400715, China; Chongqing Key Laboratory of Sericultural Science, Chongqing Engineering and Technology Research Center for Novel Silk Materials, Southwest University, Chongqing, 400715, China
| | - Ping Zhao
- Biological Science Research Center Southwest University, Chongqing, 400715, China; Chongqing Key Laboratory of Sericultural Science, Chongqing Engineering and Technology Research Center for Novel Silk Materials, Southwest University, Chongqing, 400715, China.
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12
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Li R, Hu C, Geng T, Lv D, Gao K, Guo X, Hou C. Expressional analysis of the silkworm storage protein 1 and identification of its interacting proteins. INSECT MOLECULAR BIOLOGY 2020; 29:66-76. [PMID: 31301266 DOI: 10.1111/imb.12610] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Revised: 07/07/2019] [Accepted: 07/08/2019] [Indexed: 06/10/2023]
Abstract
Storage proteins are haemolymph-specific proteins in insects, mainly synthesized in the fat body, released into the haemolymph, and then selectively reabsorbed by the fat body before pupation. These storage proteins play an important role in insect metamorphosis and egg development. Some of these storage proteins are responsive to pathogen infection and can even suppress pathogen multiplication. However, the mechanisms of the physiological, biochemical and immune-responsive functions of storage proteins remain unclear. In this study, the expression patterns of Bombyx mori storage protein 1 (BmSP1) during the larval stage were analysed. Then, BmSP1 protein fused with enhanced green fluorescent protein (EGFP) was successfully expressed in a B. mori baculovirus vector expression system. Quantitative real-time PCR showed that the expression level of BmSP1 increased with the advance of instars and reached the highest level in the fifth instar, especially in the fat body. Recombinant BmSP1 expressed in silkworm larvae inhibited haemolymph melanization. Then, proteins that interact with BmSP1 were identified with EGFP used as an antigenic determinant by co-immunoprecipitation. A 30 kDa low molecular weight lipoprotein PBMHP-6 precursor (BmLP6) was shown to interact with BmSP1. Yeast two-hybrid experiments confirmed the interaction between BmSP1 and BmLP6. The results obtained in this study will be helpful for further study of the functions of BmSP1 and BmLP6 in the regulatory network of silkworm development and innate immunity.
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Affiliation(s)
- Ruilin Li
- School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang, China
- Sericultural Research Institute, Chinese Academy of Agricultural Sciences, Zhenjiang, China
| | - Congwu Hu
- School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang, China
- Sericultural Research Institute, Chinese Academy of Agricultural Sciences, Zhenjiang, China
| | - Tao Geng
- Environment and Plant Protection Research Institute, Chinese Academy of Tropical Agricultural Sciences, Haikou, China
| | | | - Kun Gao
- School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang, China
- Sericultural Research Institute, Chinese Academy of Agricultural Sciences, Zhenjiang, China
| | - Xijie Guo
- School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang, China
- Sericultural Research Institute, Chinese Academy of Agricultural Sciences, Zhenjiang, China
| | - Chengxiang Hou
- School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang, China
- Sericultural Research Institute, Chinese Academy of Agricultural Sciences, Zhenjiang, China
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13
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Lü D, Xu P, Hou C, Gao K, Guo X. Label-free LC-MS/MS proteomic analysis of the hemolymph of silkworm larvae infected with Beauveria bassiana. J Invertebr Pathol 2019; 166:107227. [PMID: 31386830 DOI: 10.1016/j.jip.2019.107227] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2019] [Revised: 07/31/2019] [Accepted: 08/02/2019] [Indexed: 11/16/2022]
Abstract
Beauveria bassiana, a pathogen of the economically important silkworm (Bombyx mori), causes serious losses in the sericulture industry; however, the mechanisms underlying B. bassiana infection and the silkworm response are not fully understood. To obtain new insights into the interaction between B. bassiana and its host, hemolymph samples from fifth instar silkworm larvae infected with B. bassiana were analyzed at 36-h post-inoculation using a label-free LC-MS/MS proteomic technique. In total, 671 proteins were identified in the hemolymph, including 87 differentially expressed proteins, 42 up-regulated and 45 down-regulated in infected larvae. Six were detected only in infected larvae, and five were detected only in uninfected larvae. Based on GO annotations, 48 of the differentially expressed proteins were involved in molecular functions, 42 were involved in biological processes, and 39 were involved in cell components. A KEGG pathway analysis indicated that these differentially expressed proteins participate in 85 signal transduction pathways, including the amoebiasis, MAPK signaling, Hippo signaling, Toll and Imd signaling, and lysosome pathways. The silkworm hemolymph is the main site for B. bassiana replication. We identified differentially expressed proteins involved in the regulation of the host response to B. bassiana infection, providing important experimental data for the identification of key factors contributing to the interaction between the pathogenic fungus and its host.
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Affiliation(s)
| | - Ping Xu
- Sericultural Research Institute, Jiangsu University of Science and Technology, Zhenjiang 212018, China
| | - Chengxiang Hou
- Sericultural Research Institute, Jiangsu University of Science and Technology, Zhenjiang 212018, China
| | - Kun Gao
- Sericultural Research Institute, Jiangsu University of Science and Technology, Zhenjiang 212018, China
| | - Xijie Guo
- Sericultural Research Institute, Jiangsu University of Science and Technology, Zhenjiang 212018, China.
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