Read by QxMD icon Read

Erjun Ling

Erjun Ling, Zhen Zou
No abstract text is available yet for this article.
June 2018: Developmental and Comparative Immunology
Kai Wu, Fang Han, Yi Yuan, Yining Liu, Erjun Ling, Qian Wang, Wuren Huang
Insect prophenoloxidase (PPO) induces melanization around pathogens. Before melanization, PPO is cleaved into phenoloxidase (PO) by serine proteases. Insect PPO can also be activated by exogenous proteases secreted by pathogens as well as by other compounds, such as ethanol and cetylpyridinium chloride (CPC). However, the effect of these activators on the activity of PO is unclear. In this study, the insect endogenous serine protease AMM1, α-chymotrypsin, and ethanol were used to activate recombinant Drosophila PPO1 (rPPO1), and the PO activity differed depending on the activator applied...
March 23, 2018: Archives of Insect Biochemistry and Physiology
Jie Zhang, Wuren Huang, Chuanfei Yuan, Yuzhen Lu, Bing Yang, Cheng-Yuan Wang, Peng Zhang, Leonard Dobens, Zhen Zou, Chengshu Wang, Erjun Ling
Skin immunity protects animals from airborne pathogen infection. Unlike mammals, arthropods, including insects, undergo periodic ecdysis to grow and develop. Newly molted insects emerge with unsclerotized thin cuticles but successfully escape pathogenic infections during the post-molt period. Here we show that prophenoloxidases (PPOs) in molting fluids remain bioactive on the integument and impede fungal infection after ecdysis. We found that the purified plasma PPOs or recombinant PPOs could effectively bind to fungal spores (conidia) by targeting the cell wall components chitin and β-1,3-glucan...
2017: Frontiers in Immunology
Shenglei Yuan, Wuren Huang, Lei Geng, Brenda T Beerntsen, Hongsheng Song, Erjun Ling
Integuments are the first line to protect insects from physical damage and pathogenic infection. In lepidopteran insects, they undergo distinct morphology changes such as scale formation during metamorphosis. However, we know little about integument development and scale formation during this stage. Here, we use the silkworm, Bombyx mori, as a model and show that stem cells in the integument of each segment, but not intersegmental membrane, divide into two scale precursor cells during the spinning stage. In young pupae, the scale precursor cell divides again...
2017: Cell Cycle
Bing Yang, Wuren Huang, Jie Zhang, Qiuyun Xu, Shoulin Zhu, Qiaoli Zhang, Brenda T Beerntsen, Hongsheng Song, Erjun Ling
BACKGROUND: Insects can be models for understanding human intestinal infection and pathology. Molting, a special period during which the old insect cuticle is shed and a new one is produced, is crucial for insect development. Holometabolous insects may experience several larva-to-larva moltings to become larger, a pupal molt and adult eclosion to become adults. During the larval molts, they stop feeding and become quiescent. Although the molting larvae become quiescent, it is not known if changes in microbiome, physiology, development and immunity of midguts occur...
November 3, 2016: BMC Genomics
Kai Wu, Bing Yang, Wuren Huang, Leonard Dobens, Hongsheng Song, Erjun Ling
Lepidopteran insects constitute one of the largest fractions of animals on earth, but are considered pests in their relationship with man. Key to the success of this order of insects is its ability to digest food and absorb nutrition, which takes place in the midgut. Because environmental microorganisms can easily enter Lepidopteran guts during feeding, the innate immune response guards against pathogenic bacteria, virus and microsporidia that can be devoured with food. Gut immune responses are complicated by both resident gut microbiota and the surrounding peritrophic membrane and are distinct from immune responses in the body cavity, which depend on the function of the fat body and hemocytes...
November 2016: Developmental and Comparative Immunology
Kai Wu, Jie Zhang, Qiaoli Zhang, Shoulin Zhu, Qimiao Shao, Kevin D Clark, Yining Liu, Erjun Ling
Plant phenolics are a group of important secondary metabolites that are toxic to many animals and insects if ingested at high concentrations. Because most insects consume plant phenolics daily, they have likely evolved the capacity to detoxify these compounds. Here, we used Drosophila melanogaster, Bombyx mori and Helicoverpa armigera as models to study the metabolism of plant phenolics by prophenoloxidases. We found that insect foreguts release prophenoloxidases into the lumen, and that the survival of prophenoloxidase-deletion mutants was impaired when fed several plant phenolics and tea extracts...
November 23, 2015: Scientific Reports
Yujia Hu, Yi Han, Yingyao Shao, Xingjun Wang, Yeqing Ma, Erjun Ling, Lei Xue
In any gamogenetic species, attraction between individuals of the opposite sex promotes reproductive success that guarantees their thriving. Consequently, mate determination between two sexes is effortless for an animal. However, choosing a spouse from numerous attractive partners of the opposite sex needs deliberation. In Drosophila melanogaster, both younger virgin females and older ones are equally liked options to males; nevertheless, when given options, males prefer younger females to older ones. Non-volatile cuticular hydrocarbons, considered as major pheromones in Drosophila, constitute females' sexual attraction that act through males' gustatory receptors (Grs) to elicit male courtship...
January 14, 2015: Scientific Reports
Jie Zhang, Anrui Lu, Lulu Kong, Qiaoli Zhang, Erjun Ling
Molting fluid accumulates between the old and new cuticles during periodical ecdysis in Ecdysozoa. Natural defects in insect ecdysis are frequently associated with melanization (an immunity response) occurring primarily in molting fluids, suggesting that molting fluid may impact immunity as well as affect ecdysis. To address this hypothesis, proteomic analysis of molting fluids from Bombyx mori during three different types of ecdysis was performed. Many proteins were newly identified, including immunity-related proteins, in each molting fluid...
December 26, 2014: Journal of Biological Chemistry
Anrui Lu, Qiaoli Zhang, Jie Zhang, Bing Yang, Kai Wu, Wei Xie, Yun-Xia Luan, Erjun Ling
Insect prophenoloxidase (PPO) is an important innate immunity protein due to its involvement in cellular and humoral defense. It belongs to a group of type-3 copper-containing proteins that occurs in almost all organisms. Insect PPO has been studied for over a century, and the PPO activation cascade is becoming clearer. The insect PPO activation pathway incorporates several important proteins, including pattern-recognition receptors (PGRP, β GRP, and C-type lectins), serine proteases, and serine protease inhibitors (serpins)...
2014: Frontiers in Physiology
Lulu Kong, Anrui Lu, Jingmin Guan, Bing Yang, Muwang Li, Julián F Hillyer, Nalini Ramarao, Kenneth Söderhäll, Chaoliang Liu, Erjun Ling
Thermolysin, a metallopeptidase secreted by pathogenic microbes, is concluded as an important virulence factor due to cleaving purified host proteins in vitro. Using the silkworm Bombyx mori as a model system, we found that thermolysin injection into larvae induces the destruction of the coagulation response and the activation of hemolymph melanization, which results in larval death. Thermolysin triggers the rapid degradation of insect and mammalian plasma proteins at a level that is considerably greater than expected in vitro and/or in vivo...
January 2015: Archives of Insect Biochemistry and Physiology
Anrui Lu, Xuquan Li, Julián F Hillyer, Brenda T Beerntsen, Kenneth Söderhäll, Erjun Ling
Insect prophenoloxidase (PPO) is an essential innate immunity protein to induce pathogen into melanization. In Bombyx mori, pro-phenoloxidase-activating enzyme (PPAE) can directly cleave and activate PPO. However, PPO in Manduca sexta cannot be cleaved into active phenoloxidase (PO) by serine proteases unless cofactors are involved, which indicates that PPO activation is complicated. Here we use recombinant Drosophila melanogaster prophenoloxidase 1 (rPPO1) to study the mechanism of PPO activation induced by a typical serine protease, α-chymotrypsin...
July 2014: Biochimie
Anrui Lu, Qin Peng, Erjun Ling
Type 3 copper proteins, including insect prophenoloxidase (PPO), contain two copper atoms in the active site pocket and can oxidize phenols. Insect PPO plays an important role in immunity. Insects and other invertebrates show limited recovery from pathogen invasion and wounds if phenoloxidase (PO) activity is low. In most insect PPOs, two disulfide bonds are present near the C-terminus. However, in Pimpla hypochondriaca (a parasitoid wasp), each PPO contains one disulfide bond. We thus questioned whether the formation of two sulfide bonds in insect PPOs improved protein stability and/or increased insect innate immunity over time...
June 2014: Developmental and Comparative Immunology
Bing Yang, Anrui Lu, Qin Peng, Qing-Zhi Ling, Erjun Ling
Insect prophenoloxidase (PPO) is essential for physiological functions such as melanization of invading pathogens, wound healing and cuticle sclerotization. The insect PPO activation pathway is well understood. However, it is not very clear how PPO is released from hemocytes and how PPO takes part in cellular immunity. To begin to assess this, three Drosophila melanogaster PPO genes were separately fused with GFP at the C-terminus (rPPO-GFP) and were over-expressed in S2 cells. The results of staining and morphological observation show that rPPO-GFP expressed in S2 cells has green fluorescence and enzyme activity if Cu(2+) was added during transfection...
2013: PloS One
Xiaoguang Duan, Jia Xu, Erjun Ling, Peng Zhang
Lepidopteran insects affect cassava production globally, especially in intercropping system. The expression of Cry toxins in transgenic crops has contributed to an efficient control of insect pests, leading to a significant reduction in chemical insecticide usage. Helicoverpa armigera is a Lepidopteran pest that feeds on a wide range of plants like cotton and cassava. In the present study, transgenic cassava plants over-expressing Cry1Aa, which we named as Bt cassava, were developed and used to evaluate its efficacy against H...
September 2013: Plant Molecular Biology
Qiuyun Xu, Anrui Lu, Guohua Xiao, Bing Yang, Jie Zhang, Xuquan Li, Jingmin Guan, Qimiao Shao, Brenda T Beerntsen, Peng Zhang, Chengshu Wang, Erjun Ling
BACKGROUND: Lepidoptera insects have a novel development process comprising several metamorphic stages during their life cycle compared with vertebrate animals. Unlike most Lepidoptera insects that live on nectar during the adult stage, the Bombyx mori silkworm adults do not eat anything and die after egg-laying. In addition, the midguts of Lepidoptera insects produce antimicrobial proteins during the wandering stage when the larval tissues undergo numerous changes. The exact mechanisms responsible for these phenomena remain unclear...
2012: PloS One
Yupu Diao, Anrui Lu, Bing Yang, Wenli Hu, Qing Peng, Qing-Zhi Ling, Brenda T Beerntsen, Kenneth Söderhäll, Erjun Ling
In insects, hemocytes are considered as the only source of plasma prophenoloxidase (PPO). PPO also exists in the hemocytes of the hematopoietic organ that is connected to the wing disc of Bombyx mori. It is unknown whether there are other cells or tissues that can produce PPO and release it into the hemolymph besides circulating hemocytes. In this study, we use the silkworm as a model to explore this possibility. Through tissue staining and biochemical assays, we found that wing discs contain PPO that can be released into the culture medium in vitro...
2012: PloS One
Yang Chen, Fei Liu, Bing Yang, Anrui Lu, Shiwei Wang, Jingfang Wang, Qing-Zhi Ling, Xuan Li, Brenda T Beerntsen, Erjun Ling
Insect prophenoloxidase (PPO) is a key enzyme that induces melanization around invading pathogens and at wounds to prevent further infection. Drosophila melanogaster has three PPO genes which have different biochemical properties following over-expression in S2 cells. As shown by automatic melanization of S2 cells, recombinant PPO3 (rPPO3) became activated upon Cu(2+) addition (Cu(2+)-aided cells melanization without ethanol activation and substrate addition: +Cu(2+); -DOPA, -Ethanol). The exact reasons for this phenomenon are still unknown...
September 2012: Developmental and Comparative Immunology
Qimiao Shao, Bing Yang, Qiuyun Xu, Xuquan Li, Zhiqiang Lu, Chengshu Wang, Yongping Huang, Kenneth Söderhäll, Erjun Ling
Many insects eat the green leaves of plants but excrete black feces in an as yet unknown mechanism. Insects cannot avoid ingesting pathogens with food that will be specifically detected by the midgut immune system. However, just as in mammals, many pathogens can still escape the insect midgut immune system and arrive in the hindgut, where they are excreted out with the feces. Here we show that the melanization of hindgut content induced by prophenoloxidase, a key enzyme that induces the production of melanin around invaders and at wound sites, is the last line of immune defense to clear bacteria before feces excretion...
April 20, 2012: Journal of Biological Chemistry
Fei Liu, Yang Chen, Bing Yang, Jingfang Wang, Qin Peng, Qimiao Shao, Xuan Li, Brenda T Beerntsen, Yechun Xu, Jianyong Li, Xiao-Qiang Yu, Erjun Ling
Dipteran insects, like mosquitoes, possess more than two prophenoloxidase (PPO) genes, but it is unclear whether their gene products differ in biochemical properties and physiological functions. Here, we used three Drosophila melanogaster PPOs as models to study their properties through expression in S2 cells. Our data revealed that the PPOs were expressed in the ethanol-activatable conformation: rPPO1 and rPPO2 needed additional Cu(2+) in the medium, but rPPO3 did not. rPPO1 bound Cu(2+) within minutes; rPPO2 did that in hours when Cu(2+) were present at a higher concentration...
March 2012: Developmental and Comparative Immunology
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"