ALBERT

Description: 〈p〉Publication date: September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 92〈/p〉 〈p〉Author(s): Yang Hu, Wei-Chao Chen, Yu-Feng Shen, Bin Zhu, Gao-Xue Wang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Viral diseases in aquaculture were challenging because there are few preventative measures and/or treatments. Our previous study indicated that imidazole arctigenin derivatives possessed antiviral activities against infectious hematopoietic necrosis virus (IHNV). Based on the structure-activity relationship in that study, a new imidazole arctigenin derivative, 4-(8-(2-ethylimidazole)octyloxy)-arctigenin (EOA), was designed, synthesized and its anti-IHNV activity was evaluated. By comparing inhibitory concentration at half-maximal activity (IC〈sub〉50〈/sub〉), we found that EOA (IC〈sub〉50〈/sub〉 = 0.56 mg/L) possessed a higher antiviral activity than those imidazole arctigenin derivatives in our previous study. Besides, EOA could significantly decrease cytopathic effect (CPE) and viral titer induced by IHNV in epithelioma papulosum cyprinid (EPC) cells. In addition, EOA significantly inhibited apoptosis induced by IHNV in EPC cells. Further data verified that EOA inhibited IHNV replication in rainbow trout, with reducing 32.0% mortality of IHNV-infected fish. The results suggested that EOA was more stable with a prolonged inhibitory half-life in the early stage of virus infection (1–4 days). Consistent with above results, EOA repressed IHNV glycoprotein gene expression in virus sensitive tissues (kidney and spleen) in the early stage of virus infection. Moreover, histopathological evaluation showed that tissues from the spleen and kidney of fish infected with IHNV exhibited pathological changes. But there were no lesions in any of the tissues from the control group and EOA-treaten group. In accordance with the histopathological assay, EOA could elicited anti-inflammation response in non-viral infected rainbow trout by down-regulating the expression of cytokine genes (〈em〉IL-8〈/em〉, 〈em〉IL-12p40〈/em〉, and 〈em〉TNF-α〈/em〉). Altogether, EOA was expected to be a therapeutic agent against IHNV infection in the field of aquaculture.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 92〈/p〉 〈p〉Author(s): Junjun He, Haiying Liang, Jiaping Zhu, Xiaochen Fang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Antibacterial peptides (AMPs) constitute an important part of the body's innate immune system and are responsible for a wide range of inhibitory effects against pathogens such as bacteria, fungi, and viruses. In this study, multi-step high performance liquid chromatography (HPLC), combined with Mass Spectrometry (MS), was used to isolate and identify proteins with antibacterial activity from the serum of 〈em〉Pinctada fucata martensii〈/em〉 (〈em〉P.f. Martensii〈/em〉) and obtain a component named 〈em〉P.f. Martensii〈/em〉 antimicrobial peptide-1 (PmAMP-1). 〈em〉PmAMP-1〈/em〉 cDNA was cloned and sequenced by rapid amplification of cDNA ends (RACE) and mRNA expression of was analyzed by quantitative real-time PCR (qRT-PCR). From the results of this study, full-length 〈em〉PmAMP-1 c〈/em〉DNA was shown to be 700 base pairs (bp) long with an open reading frame (ORF) of 294 bp, encoding 97 amino acids with a predicted structure that is mostly α-helices. 〈em〉PmAMP-〈/em〉1 mRNA was constitutively expressed in all tested tissues including the adductor muscle, mantle, hepatopancreas, gill, gonads and hemocytes. The highest level of 〈em〉PmAMP-〈/em〉1 transcription was observed at 8 h and 2 h after bacterial challenge in hemocytes and adductor muscle (p 〈 0.01), respectively. Furthermore, PmAMP-1 caused significant morphological alterations in 〈em〉E. coli,〈/em〉 as shown by transmission electron microscopy (TEM). The results from this study provide a valuable base for further exploration of molluscan innate immunity and immune response.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 92〈/p〉 〈p〉Author(s): Bin Zhong, Zeyin Jiang, Zhenhuang Chen, Kazue Ishihara, Huilin Mao, Shanghong Wang, Gang Lin, Chengyu Hu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Recently, studies have shown that IκB kinase β (IKKβ), a critical kinase in the nucleus factor kappa-B (NF-κB) pathway, participates in inflammatory responses associated with unfolded protein response (UPR) and plays an important role in ER stress-induced cell death. The unfolded protein response (UPR), which is a regulatory system to restore cellular homeostasis in the endoplasmic reticulum (ER), such as oxidative stress, bacterial infection, and virus invasion. The UPR pathways have been reported to be involved in immune responses in mammals, including the classical NF-κB pathway. However, the molecular mechanism of their crosstalk remains to be elucidated. Previously, we demonstrated that IKKβ also has some conserved functions between fish and human, as grass carp (〈em〉Ctenopharyngodon idella〈/em〉) IKKβ (CiIKKβ) can activate NF-κB pathway. In this study, we found that CiIKKβ level in nucleus was elevated under ER stress and CiIKKβ can interact with grass carp X-box-binding protein 1 (CiXBP1S), a key transcription factor in UPR. Consistently, fluorescent histochemical analysis of grass carp kidney (CIK) cells indicated that CiIKKβ and CiXBP1S colocalized under ER stress. Furthermore, overexpression of CiIKKβ in CIK cells enhanced ER stress tolerance by regulating UPR signaling and resulted in the significant increase of cell viability.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 92〈/p〉 〈p〉Author(s): Lu-Yun Ni, Qing Han, Hong-Ping Chen, Xiao-Chun Luo, An-Xing Li, Xue-Ming Dan, Yan-Wei Li〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Macrophage expressed gene 1 (Mpeg1) is a molecule that can form pores and destroy the cell membrane of invading pathogens. In this study, we identified two Mpeg1 isoforms from the orange-spotted grouper (〈em〉Epinephelus coioides〈/em〉) and named them EcMpeg1a and EcMpeg1b. Predicted proteins of the two EcMpeg1s contained a signal peptide, a conserved membrane attack complex/perforin (MACPF) domain, a transmembrane segment, and an intracellular region. Sequence alignment demonstrated that two EcMpeg1 proteins share a high sequence identity with that of other teleosts. Tissue distribution analysis showed that EcMpeg1s were expressed in all tissues tested in healthy grouper, with the highest expression in the head kidney and spleen. After infection with the ciliate parasite 〈em〉Cryptocaryon irritans〈/em〉, expression of the two EcMpeg1s was significantly upregulated in the spleen and gills. Furthermore, the recombinant EcMpeg1a showed antiparasitic and antibacterial activity against Gram-negative and -positive bacteria, whereas EcMpeg1b had an inhibitory effect only against Gram-positive bacteria. These results indicated that EcMpeg1s play an important role in the host response against invading pathogens.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 92〈/p〉 〈p〉Author(s): Pengfei Chu, Libo He, Cheng Yang, Wencheng Zeng, Rong Huang, Lanjie Liao, Yongming Li, Zuoyan Zhu, Yaping Wang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Autophagy is an essential and conserved process that plays an important role in physiological homeostasis, adaptive response to stress and the immune response. Autophagy-related proteins (ATGs) are key components of the autophagic machinery. In the study, grass carp (〈em〉Ctenopharyngodon idella〈/em〉) autophagy-related gene 5 (〈em〉ATG5〈/em〉) and 12 (〈em〉ATG12〈/em〉) were identified. In the gill and intestine, 〈em〉ATG5〈/em〉 and 〈em〉ATG12〈/em〉 were highly expressed, but after grass carp reovirus (GCRV) infection, they were decreased significantly. In 〈em〉Ctenopharyngodon idella〈/em〉 kidney (CIK) cells, the sharp variation of 〈em〉ATG5〈/em〉 and 〈em〉ATG12〈/em〉 expression was observed after poly(I:C) infection. Subcellular localisation showed that ATG5 and ATG12 were evenly distributed in the cytoplasm and nucleus. However, the interaction between ATG5 and ATG12 was only found in cytoplasm in both 293T cells and CIK cells. In addition, the overexpression of ATG5 or ATG12 in 293T cells showed enhanced autophagy, and autophagic process was facilitated when ATG5 and ATG12 were simultaneously overexpressed. Dual-luciferase activity assay indicated that both ATG5 and ATG12 remarkably suppressed the promoter activity of 〈em〉IRF3〈/em〉, 〈em〉IRF7〈/em〉, and 〈em〉IFN-I〈/em〉. Further, ATG5 and ATG12 conjugate showed far stronger inhibitory affection on the expression of 〈em〉IFN-I〈/em〉 than either ATG5 or ATG12 in response to poly(I:C) or GCRV infection. Taken together, the results demonstrate that grass carp ATG5 and ATG12 play an important role in innate immunity and autophagy.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 92〈/p〉 〈p〉Author(s): Chao Xu, Wen-Bin Liu, Sofie Charlotte Remø, Bing-Ke Wang, Hua-Juan Shi, Li Zhang, Jia-Dai Liu, Xiang-Fei Li〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉This study investigated the effects of restricted feeding on the growth performance, oxidative stress and inflammation of 〈em〉Megalobrama amblycephala〈/em〉 fed high-carbohydrate (HC) diets. Fish (46.94 ± 0.04 g) were randomly assigned to four groups containing the satiation of a control diet (30% carbohydrate) and three satiate levels (100% (HC1), 80% (HC2) and 60% (HC3)) of the HC diets (43% carbohydrate) for 8 weeks. Results showed that HC1 diet remarkably decreased final weight (FW), weight gain rate (WGR), specific growth rate (SGR), feed conversion ratio (FCR), hepatic activities of total anti-oxidation capacity (T-AOC), superoxide dismutase (SOD) and catalase (CAT), the AMP/ATP ratio, the p-AMPKα/t-AMPKα ratio, sirtuin-1 (SIRT1) protein expression and hepatic transcriptions of AMPKα2, SIRT1, nuclear factor erythroid 2-related factor 2 (Nrf2), catalase (CAT), manganese superoxide dismutase (Mn-SOD), glutathione peroxidase 1 (GPx1) and interleukin10 (IL 10) compared to the control group, whereas the opposite was true for protein efficiency ratio (PER), nitrogen retention efficiency (NRE), energy retention efficiency (ERE), plasma glucose levels, alanine transaminase (AST) and aspartate aminotransferase (ALT) activities, hepatic contents of malondialdehyde (MDA), tumour necrosis factor α (TNF α) and interleukin 1β (IL 1β), ATP and AMP contents and hepatic transcriptions of kelch-like ECH associating protein 1 (Keap1), IkB kinase α (IKK α), nuclear factor kappa B (NF-κB), TNF α, IL 1β, interleukin 6 (IL 6) and transforming growth factor β (TGF β). As for the HC groups, fish fed the HC2 diet obtained relatively high values of SGR, PER, NRE, ERE, hepatic activities of T-AOC, SOD and CAT, the AMP/ATP ratio, the p-AMPKα/t-AMPKα ratio, SIRT1 protein expression and hepatic transcriptions of AMPKα2, Nrf2, CAT, copper/zinc superoxide dismutase (Cu/Zn-SOD), Mn-SOD, GPx1, glutathione S-transferase (GST) and interleukin10 (IL 10), while the opposite was true for hepatic content of IL 6 and transcription of IKK α. Overall, an 80% satiation improved the growth performance and alleviated the oxidative stress and inflammation of blunt snout bream fed HC diets via the activation of the AMPK-SIRT1 pathway and the up-regulation of the activities and transcriptions of Nrf2-modulated antioxidant enzymes coupled with the depression of the levels and transcriptions of the NF-κB-mediated pro-inflammatory cytokines.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 92〈/p〉 〈p〉Author(s): Jiangfan Zhang, Chuanju Dong, Junchang Feng, Junpeng Li, Shengjie Li, Jianxin Feng, Xiaodi Duan, Gaigai Sun, Peng Xu, Xuejun Li〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉〈em〉HIFs〈/em〉 (Hypoxia inducible factors) are the main regulators of the expression change of oxygen-dependent genes, in addition, they also play important roles in immune regulation. 〈em〉HIFs〈/em〉 participate in infectious diseases and inflammatory responses, providing us a new therapeutic target for the treatment of diseases. In this study, 16 〈em〉HIFs〈/em〉 were identified in common carp genome database. Comparative genomics analysis showed large expansion of 〈em〉HIF〈/em〉 gene family and approved the four round whole genome duplication (WGD) event in common carp. To further understand the function of 〈em〉HIFs〈/em〉, the domain architectures were predicted. All HIF proteins had the conserved HLH-PAS domain, which were essential for them to form dimer and bind to the downstream targets. The differences in domain of HIFα and HIFβ might result in their different functions. Phylogenetic analysis revealed that all 〈em〉HIFs〈/em〉 were divided into two subfamilies and the 〈em〉HIFs〈/em〉 in common carp were clustered with their teleost counterparts indicating they are highly conservative during evolution. In addition, the tissue distribution was examined by RT-PCR showed that most of 〈em〉HIF〈/em〉 genes had a wide range of tissue distribution but exhibited tissue-specific expression patterns. The expression divergences were observed between the copy genes, for example, 〈em〉HIF1A-1〈/em〉, 〈em〉HIF2A-1〈/em〉, 〈em〉ARNT-〈/em〉2 had wide tissue distribution while their copies had limited tissue distribution, proving the function divergence of copies post the WGD event. In order to find an effective activation of 〈em〉HIFs〈/em〉 and apply to treatment of aquatic diseases, we investigate the dietary supplementation effects of different strains of 〈em〉Lactococcus lactis〈/em〉 on the expression of 〈em〉HIFα〈/em〉 subfamily members in kidney of common carp infected with 〈em〉A. hydrophila〈/em〉. In addition, all of the 〈em〉HIF〈/em〉 genes have a high expression in the early stages of infection, and decreased in the treatment time point of 48 h in common carp. This phenomenon confirms that as a switch, the main function of 〈em〉HIFs〈/em〉 is to regulate the production of immune response factors in early infection. So activation of the switch may be an effective method for infectious disease treatment. As expected, the treatment groups improved the expression of 〈em〉HIFs〈/em〉 compared with the control group, and the effects of the three strains are different. The strain1 of 〈em〉L. lactis〈/em〉 had a stronger induction on 〈em〉HIF〈/em〉 genes than strain2 and strain3, and it might be applied as a potential activation of 〈em〉HIF〈/em〉 genes for disease treatment. So, adding befitting 〈em〉L. lactis〈/em〉 maybe a well method to activate the 〈em〉HIF〈/em〉 genes to protect them from mycobacterial infection.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 92〈/p〉 〈p〉Author(s): K.A.S.N. Shanaka, M.D. Neranjan Tharuka, Thanthrige Thiunuwan Priyathilaka, Jehee Lee〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Viperin, also known as RSAD2 (Radical S-adenosyl methionine domain containing 2), is an interferon-induced endoplasmic reticulum-associated antiviral protein. Previous studies have shown that viperin levels are elevated in the presence of viral RNA, but it has rarely been characterized in marine organisms. This study was designed to functionally characterize rockfish viperin (〈em〉SsVip〈/em〉), to examine the effects of different immune stimulants on its expression, and to determine its subcellular localization. SsVip is a 349 amino acid protein with a predicted molecular mass of 40.24 kDa. It contains an S-adenosyl 〈span〉l〈/span〉-methionine binding conserved domain with a CNYKCGFC sequence. Unchallenged tissue expression analysis using quantitative real time PCR (qPCR) revealed 〈em〉SsVip〈/em〉 expression to be the highest in the blood, followed by the spleen. When challenged with poly I:C, 〈em〉SsVip〈/em〉 was upregulated by approximately 60-fold in the blood after 24 h, and approximately 50-fold in the spleen after 12 h. Notable upregulation was detected throughout the poly I:C challenge experiment in both tissues. Significant expression of 〈em〉SsVip〈/em〉 was detected in the blood following 〈em〉Streptococcus iniae〈/em〉 and lipopolysaccharide challenge, and viral hemorrhagic septicemia virus (VHSV) gene transcription was significantly downregulated during SsVip overexpression. Furthermore, cell viability assay and virus titer quantification with the presence of SsVip revealed a significant reduction in virus replication. As with previously identified viperin counterparts, SsVip was localized in the endoplasmic reticulum. Our findings show that SsVip is an antiviral protein crucial to innate immune defense.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 93〈/p〉 〈p〉Author(s): Jing Li, Zhi-Bin Wu, Zhao Zhang, Ji-Wei Zha, Shen-Ye Qu, Xiao-Zhou Qi, Gao-Xue Wang, Fei Ling〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Nowadays, there is no suitable treatment for vibriosis in groupers. So an eco-efficient and environmentally friendly treatment is necessary for the grouper industry. Probiotic-feeding has been a promising strategy to control the bacterial pathogens in aquaculture. A new 〈em〉Bacillus velezensis〈/em〉 strain named K2 was isolated from the intestinal tract of healthy grouper, and exhibited wide antimicrobial spectrum of against fish pathogens, including 〈em〉Vibrio harveyi〈/em〉, 〈em〉Vibrio alginolyticus〈/em〉, 〈em〉Aeromonas hydrophila〈/em〉, 〈em〉Aeromonas veronii〈/em〉, 〈em〉Aeromonas caviae〈/em〉, 〈em〉Enterococcus casseliflavus〈/em〉 and 〈em〉Lactococcus garvieae〈/em〉. Moreover, results of the safety of 〈em〉B. velezensis〈/em〉 K2 showed that intraperitoneal injection of K2 in healthy grouper did not cause any pathological abnormality or death, indicating this bacteria could be considered as a candidate probiotic in aquaculture. Groupers were fed with the diets containing 1 × 10〈sup〉7〈/sup〉 cfu/g of 〈em〉B. velezensis〈/em〉 K2 for 4 weeks. Various immune parameters were examined at 1, 2, 3, and 4 weeks of post-feeding. Results showed that diets supplemented with K2 significantly increased serum acid phosphatase (ACP) activity (〈em〉P〈/em〉 〈 0.05). Results of the mRNA expression of immune-related genes in the head kidney of hybrid grouper showed that the expression of lysozyme gene was significantly upregulated after 1 and 2 weeks of feeding (〈em〉P〈/em〉 〈 0.05). A significant up-regulation of the expression of piscidin, IgM and MyD88 were detected at day 21, whereas the TLR3 and TLR5 showed lower expression compared to the controls during 21 days, and a significant decrease of TLR3 gene was found at day 28 (〈em〉P〈/em〉 〈 0.05). After challenge with 〈em〉V. harveyi〈/em〉, the survival rate of fish administrated with the strain K2 for 28 days was signifiacantly higher than the controls without this strain (〈em〉P〈/em〉 〈 0.05). These results collectively suggest that 〈em〉B. velezensis〈/em〉 K2 is a potential probiotic species to improve health status and disease resistance and can be developed as a probiotic agent in grouper industry.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 93〈/p〉 〈p〉Author(s): Phennapa Promthale, Pattira Pongtippatee, Boonsirm Withyachumnarnkul, Kanokpan Wongprasert〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Fishmeal is the main source of protein in the shrimp feed industry and is normally derived from trash fish. As such, the production of fishmeal has an adverse effect on the marine environment by taking away small and juvenile fish, leading to depletion of marine species. There is a need for alternative sources of protein which will substitute fishmeal in the aquaculture industry. This study evaluated the components and nutritional efficacy of bioflocs, which were used to substitute fishmeal protein. The effect of bioflocs diets on growth performance, survival rate, and immune response in shrimp compared to normal fishmeal feed were determined. Bioflocs were harvested from the shrimp ponds (C:N ratio 〉12:1) at Shrimp Village, Chaiya district, Surat Thani, Thailand. The total protein in bioflocs was about 48% and the total lipid was about 5% (dried weight) and the percentages of essential amino acids (EAA) and fatty acids (EFA) in bioflocs were similar to those of fishmeal feed. Shrimp fed with the different dietary bioflocs feed regimens [% to replace fishmeal; 0% (B0), 25% (B25), 50% (B50), 75% (B75), and 100% (B100)] for 42 days revealed that all growth parameters were almost similar to those of the control shrimp (shrimp fed with normal fishmeal, B0) including final body weight, weight gain, specific growth rate, and feed conversion ratio. Remarkably, the survival rates, the levels of immune parameters, and expression of immune genes (proPO-I, PEN-4 and dicer) were significantly higher in bioflocs fed shrimp, especially in B25 and B50 shrimp. Moreover, B25 and B50 bioflocs fed shrimp showed notably increased survival rates following 〈em〉Vibrio parahaemolyticus (V. parahaemolyticus)〈/em〉 infection. In conclusion, the present study demonstrates that shrimp survival and immunity are enhanced by biofiocs substituted fishmeal. Significantly, the bioflocs diets activated the immune response to prevent 〈em〉V. parahaemolyticus〈/em〉 infection.〈/p〉〈/div〉 〈/div〉