Publications by authors named "Jinmo Koo"

6 Publications

  • Page 1 of 1

systemic RNA interference defective protein 1 enhances RNAi efficiency in a lepidopteran insect, the fall armyworm, in a tissue-specific manner.

RNA Biol 2020 Nov 9:1-9. Epub 2020 Nov 9.

Department of Botany, Kongunadu Arts and Science College (Autonomous), Bharathiar University, Coimbatore, India.

RNA interference (RNAi) is an important tool for gene function studies in insects, especially in non-model insects. This technology is also being developed for pest control. However, variable RNAi efficiency among insects is limiting its use in insects. Systemic RNAi in requires systemic RNA interference defective protein 1 (. The expression of Ce in insect cell lines was shown to improve RNAi. However, the mechanisms through which this double-stranded RNA (dsRNA) transporter improves RNAi efficiency in insects is not known. We stably expressed in two cell lines, Sf9 and Sf17 cells derived from ovary and midgut, respectively. Expression of enhanced RNAi efficiency in ovarian Sf9 cells, but not in midgut Sf17 cells. Reduced accumulation of dsRNA in late endosomes and successful processing dsRNA to siRNA contribute to enhanced RNAi efficiency in Sf9 cells. Transgenic expressing were produced and tested for RNAi efficiency. RNAi efficiency enhancement due to expression showed tissue specificity. Compared to RNAi efficiency in wild-type expressing transgenic showed a significant improvement of RNAi in tissues such as Verson's glands. In contrast, no improvement in RNAi was observed in tissues such as midgut. The cell-type specific and tissue-specific enhancement of RNAi efficiency by in provides valuable information for improving RNAi in insects such as those belonging to order Lepidoptera where RNAi is variable and inefficient.
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http://dx.doi.org/10.1080/15476286.2020.1842632DOI Listing
November 2020

Transport of orally delivered dsRNA in southern green stink bug, Nezara viridula.

Arch Insect Biochem Physiol 2020 Aug 22;104(4):e21692. Epub 2020 May 22.

Department of Entomology, University of Kentucky, Lexington, Kentucky.

The southern green stink bug (SGSB, Nezara viridula) is an emerging polyphagous pest in many regions of the world. RNA interference (RNAi) is a valuable method for understanding gene function and holds great potential for pest management. However, RNAi efficiency is variable among insects and the differences in transport of double-stranded RNA (dsRNA) are one of the major factors that contribute to this variability. In this study, Cy3 labeled dsRNA was used to track the transport of dsRNA in SGSB tissues. Cy3_dsRNA was detected in the hemocytes, fat body (FB), epidermis, and midgut tissues at 24-72 hr after injection. Orally delivered Cy3_dsRNA or Cypher-5E labeled dsRNA was mostly detected in the midgut and a few signals were detected in parts of the FB and epidermis. Both injected and fed Cy3_dsRNA showed stronger signals in SGSB tissues when compared to Cy3_siRNA (small interfering RNA) or Cy3_shRNA (short hairpin RNA). dsRNA targeting the gene for a vacuolar-sorting protein, SNF7, induced higher knockdown of the target gene and greater SGSB mortality compared to siRNA or shRNA targeting this gene. P-labeled dsRNA injected into SGSB was processed into siRNA, but fed P-labeled dsRNA was not efficiently processed into siRNA. These data suggest that transport of orally delivered dsRNA across the midgut epithelium is not efficient in SGSB which may contribute to variable RNAi efficiency. Targeting genes expressed in the midgut rather than other tissues and using dsRNA instead of siRNA or shRNA would be more effective for RNAi-mediated control of this pest.
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http://dx.doi.org/10.1002/arch.21692DOI Listing
August 2020

Evaluation of inhibitor of apoptosis genes as targets for RNAi-mediated control of insect pests.

Arch Insect Biochem Physiol 2020 Aug 11;104(4):e21689. Epub 2020 May 11.

Department of Entomology, University of Kentucky, Lexington, Kentucky.

Apoptosis has been widely studied from mammals to insects. Inhibitor of apoptosis (IAP) protein is a negative regulator of apoptosis. Recent studies suggest that iap genes could be excellent targets for RNA interference (RNAi)-mediated control of insect pests. However, not much is known about iap genes in one of the well-known insect model species, Tribolium castaneum. The orthologues of five iap genes were identified in T. castaneum by searching its genome at NCBI (https://www.ncbi.nlm.nih.gov/) and UniProt (https://www.uniprot.org/) databases using Drosophila melanogaster and Aedes aegypti IAP protein sequences as queries. RNAi assays were performed in T. castaneum cell line (TcA) and larvae. The knockdown of iap1 gene induced a distinct apoptotic phenotype in TcA cells and induced 91% mortality in T. castaneum larvae. Whereas, knockdown of iap5 resulted in a decrease in cell proliferation in TcA cells and developmental defects in T. castaneum larvae which led to 100% mortality. Knockdown of the other three iap genes identified did not cause a significant effect on cells or insects. These data increase our understanding of iap genes in insects and provide opportunities for developing iap1 and iap5 as targets for RNAi-based insect pest control.
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http://dx.doi.org/10.1002/arch.21689DOI Listing
August 2020

RNA interference-mediated control of cigarette beetle, Lasioderma serricorne.

Arch Insect Biochem Physiol 2020 Aug 28;104(4):e21680. Epub 2020 Apr 28.

Department of Entomology, College of Agriculture, University of Kentucky, Lexington, Kentucky.

The cigarette beetle (CB; Lasioderma serricorne) is a pest on many stored products including tobacco. Fumigation is the common control method currently used. However, the options for controlling this pest are limited, due to resistance issues and phasing out of currently used chemical insecticides. Here, we evaluated RNA interference (RNAi) as a potential method for controlling the CB. RNA isolated from different stages was sequenced and assembled into a transcriptome. The CB RNA sequences showed the highest homology with those in the red flour beetle, Tribolium castaneum. Orthologs of proteins known to function in RNAi pathway were identified in the CB transcriptome, suggesting that RNAi may work well in this insect. Also, P-labeled double-stranded RNA (dsRNA) injected into CB larvae and adults was processed to small interference RNAs. We selected 12 genes that were shown to be the effective RNAi targets in T. castaneum and other insects and identified orthologs of them in the CB by searching its transcriptome. Injection of dsRNA targeting genes coding for GAWKY, Kinesin, Sec23, SNF7, and 26S proteasome subunit 6B into the CB larvae caused 100% mortality. Feeding dsRNA targeting SNF7 and 26S proteasome subunit 6B by sucrose droplet assay induced more than 90% mortality, which is 1.8 times higher than the mortality induced by dsGFP control (53%). These data demonstrate an efficient RNAi response in CB, suggesting that RNAi could be developed as an efficient method to control this pest.
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http://dx.doi.org/10.1002/arch.21680DOI Listing
August 2020

Hydrolysis of Hyaluronic Acid in Lymphedematous Tissue Alleviates Fibrogenesis via T1 Cell-Mediated Cytokine Expression.

Sci Rep 2017 02 24;7(1):35. Epub 2017 Feb 24.

Department of Genetic Engineering, Sungkyunkwan University, Suwon, 16419, Republic of Korea.

Although surgery and radiation are beneficial for treating cancer, they can also lead to malfunctions of the lymphatic system such as secondary lymphedema. This abnormality of the lymphatic system is characterized by severe swelling, adipogenesis, inflammation, and fibrosis in the lymphedematous region. Moreover, the proliferation of fibrotic tissue in the lymphedematous region generates edema that is no longer spontaneously reversible. No treatment for fibrosis has been validated in patients with lymphedema. In our efforts to develop a therapeutic agent for lymphedema fibrosis, we used a newly established mouse hind limb model. Previous studies have demonstrated that hyaluronic acid accumulates in the lymphedematous region. Thus, we challenged mice with of hyaluronidase (HYAL), with the aim of reducing fibrogenesis. After subcutaneous injections in the lymphedematous mouse leg every two days, the volume of lymphedema had reduced significantly by 7 days post-operation. Histochemical analysis indicated that collagen accumulation and myofibroblast differentiation were decreased in epidermal tissues after HYAL injection. Moreover, it was associated with upregulation of interferon-gamma, increased numbers of Th1 cells, and downregulation of interleukin-4 and interleukin-6 in the lymphedematous region and spleen. These results indicate that hydrolysis of hyaluronic acid can boost an anti-fibrotic immune response in the mouse lymphedema model.
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http://dx.doi.org/10.1038/s41598-017-00085-zDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5428353PMC
February 2017

Effects of Lactobacillus acidophilus supplementation on growth performance, nutrient digestibility, fecal microbial and noxious gas emission in weaning pigs.

J Sci Food Agric 2017 Mar 28;97(4):1310-1315. Epub 2016 Jul 28.

Department of Animal Resource & Science, Dankook University, Cheonan, Choongnam 330-714, South Korea.

Background: Antibiotics used as growth promoters in livestock have been banned in the European Union since 2006. Antibiotics alternatives have focused on probiotics, such as Lactobacillus acidophilus. The concentration of L. acidophilus is considered crucial for obtaining the desired effects. However, limited studies have been conducted to test the dose-dependent effects of L. acidophilus. Therefore, the present study aimed to test the dose-dependent effects of L. acidophilus on growth performance, nutrient digestibility, fecal microbial flora and fecal noxious gas emission in weaning pigs.

Results: Lactobacillus acidophilus supplementation increased (P < 0.05) average daily gain, average daily feed intake, apparent nutrient digestibility of dry matter, nitrogen and gross energy, and Lactobacillus counts compared to the basal diet treatment, and a linear effect (P < 0.05) was observed on those criteria. Escherichia coli counts and NH emission were decreased (P < 0.05) by L. acidophilus supplementation, and a linear effect (P < 0.05) was observed on E. coli counts.

Conclusion: These results suggest that L. acidophilus could be used as an antibiotic alternative by improving growth performance, nutrient digestibility and gut balance (i.e. increased Lactobacillus counts and decreased E. coli counts), and decreasing NH3 emission, of weaning pigs. © 2016 Society of Chemical Industry.
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http://dx.doi.org/10.1002/jsfa.7866DOI Listing
March 2017