Characterization and function analysis of Hsp60 and Hsp10 under different acute stresses in black tiger shrimp, Penaeus monodon

Toxicity of Ammonia Stress on the Physiological Homeostasis in the Gills of Litopenaeus vannamei under Seawater and Low-Salinity Conditions

Ammonia is a major water quality factor influencing the survival and health of shrimp, among which the gill is the main effector organ for ammonia toxicity. In this study, we chose two types of Litopenaeus vannamei that were cultured in 30‱ seawater and domesticated in 3‱ low salinity, respectively, and then separately subjected to ammonia stress for 14 days under seawater and low-salinity conditions, of which the 3‱ low salinity-cultured shrimp were domesticated from the shrimp cultured in 30‱ seawater after 27 days of gradual salinity desalination. In detail, this study included four groups, namely the SC group (ammonia-N 0 mg/L, salinity 30‱), SAN group (ammonia-N 10 mg/L, salinity 30‱), LC group (ammonia-N 0 mg/L, salinity 3‱), and LAN group (ammonia-N 10 mg/L, salinity 3‱). The ammonia stress lasted for 14 days, and then the changes in the morphological structure and physiological function of the gills were explored. The results show that ammonia stress caused the severe contraction of gill filaments and the deformation or even rupture of gill vessels. Biochemical indicators of oxidative stress, including LPO and MDA contents, as well as T-AOC and GST activities, were increased in the SAN and LAN groups, while the activities of CAT and POD and the mRNA expression levels of antioxidant-related genes (nrf2, cat, gpx, hsp70, and trx) were decreased. In addition, the mRNA expression levels of the genes involved in ER stress (ire1 and xbp1), apoptosis (casp-3, casp-9, and jnk), detoxification (gst, ugt, and sult), glucose metabolism (pdh, hk, pk, and ldh), and the tricarboxylic acid cycle (mdh, cs, idh, and odh) were decreased in the SAN and LAN groups; the levels of electron-transport chain-related genes (ndh, cco, and coi), and the bip and sdh genes were decreased in the SAN group but increased in the LAN group; and the level of the ATPase gene was decreased but the cytc gene was increased in the SAN and LAN groups. The mRNA expression levels of osmotic regulation-related genes (nka-β, ca, aqp and clc) were decreased in the SAN group, while the level of the ca gene was increased in the LAN group; the nka-α gene was decreased in both two groups. The results demonstrate that ammonia stress could influence the physiological homeostasis of the shrimp gills, possibly by damaging the tissue morphology, and affecting the redox, ER function, apoptosis, detoxification, energy metabolism, and osmoregulation.

Heat shock protein paradigms in cancer progression: future therapeutic perspectives

Heat-shock proteins (HSPs), also known as stress proteins, are ubiquitously present in all forms of life. They play pivotal roles in protein folding and unfolding, the formation of multiprotein complexes, the transportation and sorting of proteins into their designated subcellular compartments, the regulation of the cell cycle, and signalling processes. These HSPs encompass HSP27, HSP40, HSP70, HSP60, and HSP90, each contributing to various cellular functions. In the context of cancer, HSPs exert influence by either inhibiting or activating diverse signalling pathways, thereby impacting growth, differentiation, and cell division. This article offers an extensive exploration of the functions of HSPs within the realms of pharmacology and cancer biology. HSPs are believed to play substantial roles in the mechanisms underlying the initiation and progression of cancer. They hold promise as valuable clinical markers for cancer diagnosis, potential targets for therapeutic interventions, and indicators of disease progression. In times of cellular stress, HSPs function as molecular chaperones, safeguarding the structural and functional integrity of proteins and aiding in their proper folding. Moreover, HSPs play a crucial role in cancer growth, by regulating processes such as angiogenesis, cell proliferation, migration, invasion, and metastasis.

Toxic effects of triclocarban on the histological morphology, physiological and immune response in the gills of the black tiger shrimp Penaeus monodon

Triclocarban (TCC) is a widely used broad-spectrum antimicrobial agent that has become a pollutant threatening the health of aquatic animals. However, the toxic effects of TCC on Penaeus monodon are still lacking. In this study, we exposed P. monodon to 1 μg/L (TCC-1) and 10 μg/L TCC (TCC-10) for 14 days, and the changes of histological morphology, physiological and immune responses in the gills were investigated. The results showed that TCC exposure caused the deformation of the gill vessels and the disordered arrangement of the gill filaments. Oxidative stress biochemical indexes such as H2O2 content, CAT and GPx activity and the relative expression levels of antioxidant-related genes (SOD, GPx and Nrf2) were increased in the TCC-1 and TCC-10 groups; the levels of CAT and HSP70 genes were increased but POD activity was decreased in the TCC-10 group. The relative expression levels of endoplasmic reticulum (ER) stress indexes such as ERP15 and ATF-6 genes were increased in the TCC-10 group, while the level of GRP78 gene was decreased in the TCC-1 and TCC-10 groups. The relative expression levels of apoptosis indexes such as p53 and JNK genes were increased, but CytC and Casp-3 genes were decreased in the TCC-1 and TCC-10 groups. Furthermore, the relative expression levels of detoxification metabolism-related genes (cytP450 and GST) and osmotic regulation-related genes (NKA-α, NKA-β, CA, AQP, CLC and CCP) were increased in the TCC-10 group. The results showed that TCC exposure could affect the physiological homeostasis in the gills of P. monodon, probably via damaging histological morphology, inducing oxidative stress, and disordering ER stress, apoptosis, detoxification and osmotic regulation.

A novel perlucin-like protein (PLP) protects Litopenaeus vannamei against Vibrio harveyi infection

C-type lectins (CTLs), as pattern recognition receptors (PRRs), play an important role in the innate immunity of Litopenaeus vannamei. In this study, a novel CTL, named perlucin-like protein (PLP), was identified from L. vannamei, which shared homology sequences of PLP from Penaeus monodon. PLP from L. vannamei was expressed in the hepatopancreas, eyestalk, muscle and brain and could be activated in the tissues (hepatopancreas, muscle, gill and intestine) after infection with the pathogen Vibrio harveyi. Bacteria (Vibrio alginolyticus, V. parahaemolyticus, V. harveyi, Streptococcus agalactiae and Bacillus subtilis) could be bound and agglutinated by the PLP recombinant protein in a Ca2+-dependent manner. Moreover, PLP could stabilise the expression of the immune-related genes (ALF, SOD, HSP70, Toll4 and IMD) and apoptosis gene (Caspase2). The RNAi of PLP could remarkably affect the expression of antioxidant gene, antimicrobial peptide genes, other CTLs, apoptosis genes, Toll signaling pathways, and IMD signaling pathways. Moreover, PLP reduced the bacterial load in the hepatopancreas. These results suggested that PLP was involved in the innate immune response against V. harveyi infection by recognising bacterial pathogens and activating the expression of immune-related and apoptosis genes.

Transcriptional and metabolomic investigation of the stress response in snow crab during simulated transport condition (Chionoecetes opilio)

The molecular mechanisms underlying the stress response are poorly described in crustaceans. This includes the snow crab (Chionoecetes opilio), a commercially important stenotherm species distributed throughout the northern hemisphere. A better understanding of the stress response in C. opilio is desperately needed for commercial and conservation purposes. The purpose of this study was to investigate the transcriptional and metabolomic response of C. opilio exposed to stressors. Crabs were randomly assigned to 24 or 72 h treatment groups where they were exposed to conditions simulating live transport (handling and air exposure). A control group was kept in cold (2 °C) and well‑oxygenated saltwater. The hepatopancreas of the crabs was sampled to perform RNA-sequencing and high-performance chemical isotope labeling metabolomics. Differential gene expression analyses showed that classic crustaceans' stress markers, such as crustacean hyperglycemic hormones and heat shock proteins, were overexpressed in response to stressors. Tyrosine decarboxylase was also up-regulated in stressed crabs, suggesting an implication of the catecholamines tyramine and octopamine in the stress response. Deregulated metabolites revealed that low oxygen was an important trigger in the stress response as intermediate metabolites of the tricarboxylic acid cycle (TCA) accumulated. Lactate, which accumulated unevenly between crabs could potentially be used to predict mortality. This study provides new information on how stressors affect crustaceans and provides a basis for the development of stress markers in C. opilio.

A novel C-type lectin for Litopenaeus vannamei involved in the innate immune response against Vibrio infection

C-type lectins (CTLs), as a member of pattern recognition receptors, play a vital role in the innate immune response of invertebrates to eliminate micro-invaders. In this study, a novel CTL of Litopenaeus vannamei, namely, LvCTL7, was successfully cloned, with an open reading frame of 501 bp and a capability to encode 166 amino acids. Blast analysis showed that the amino acid sequence similarity between LvCTL7 and MjCTL7 (Marsupenaeus japonicus) was 57.14%. LvCTL7 was mainly expressed in hepatopancreas, muscle, gill and eyestalk. Vibrio harveyi can significantly affect LvCTL7 expression level in hepatopancreases, gills, intestines and muscles (p < 0.05). LvCTL7 recombinant protein can bind to Gram-positive bacteria (Bacillus subtilis) and Gram-negative bacteria (Vibrio parahaemolyticus and V. harveyi). It can cause the agglutination of V. alginolyticus and V. harveyi, but it had no effect on Streptococcus agalactiae and B. subtilis. The expression levels of SOD, CAT, HSP 70, Toll 2, IMD and ALF genes in the challenge group added with LvCTL7 protein were more stable than those in the direct challenge group (p < 0.05). Moreover, knockdown of LvCTL7 by double-stranded RNA interference downregulated the expression levels of genes (ALF, IMD and LvCTL5) that protect against bacterial infection (p < 0.05). These results indicated that LvCTL7 had microbial agglutination and immunoregulatory activity, and it was involved in the innate immune response against Vibrio infection in L. vannamei.

Transcriptome analysis of hepatopancreas in penaeus monodon under acute low pH stress

The decrease of seawater pH can affect the metabolism, acid-base balance, immune response and immunoprotease activity of aquatic animals, leading to aquatic animal stress, impairing the immune system of aquatic animals and weakening disease resistance, etc. In this study, we performed high-throughput sequencing analysis of the hepatopancreas transcriptome library of low pH stress penaeus monodon, and after sequencing quality control, a total of 43488612-56271828 Clean Reads were obtained, and GO annotation and KEGG pathway enrichment analysis were performed on the obtained Clean Reads, and a total of 395 DEGs were identified. we mined 10 differentially expressed and found that they were significantly enriched in the Metabolic pathways (ko01100), Biosynthesis of secondary metabolites (ko01110), Nitrogen metabolism (ko00910) pathways, such as PIGA, DGAT1, DGAT2, UBE2E on Metabolic pathways; UGT, GLT1, TIM genes on Biosynthesis of secondary metabolites; CA, CA2, CA4 genes on Nitrogen metabolism, are involved in lipid metabolism, induction of oxidative stress and inflammation in the muscular body of spot prawns. These genes play an important role in lipid metabolism, induction of oxidative stress and inflammatory response in the muscle of the shrimp. In summary, these genes provide valuable reference information for future breeding of low pH-tolerant shrimp.

Heat Shock Proteins (Hsps) in Cellular Homeostasis: A Promising Tool for Health Management in Crustacean Aquaculture

Heat shock proteins (Hsps) are a family of ubiquitously expressed stress proteins and extrinsic chaperones that are required for viability and cell growth in all living organisms. These proteins are highly conserved and produced in all cellular organisms when exposed to stress. Hsps play a significant role in protein synthesis and homeostasis, as well as in the maintenance of overall health in crustaceans against various internal and external environmental stresses. Recent reports have suggested that enhancing in vivo Hsp levels via non-lethal heat shock, exogenous Hsps, or plant-based compounds, could be a promising strategy used to develop protective immunity in crustaceans against both abiotic and biotic stresses. Hence, Hsps as the agent of being an immune booster and increasing disease resistance will present a significant advancement in reducing stressful conditions in the aquaculture system.

Apoptotic susceptibility of pancreatic alpha cells to environmentally relevant dose levels of bisphenol-A versus dibutyl phthalate is mediated by HSP60/caspase-3 expression in male albino rats

Unfortunately, humanity is exposed to mixed plasticizers such as bisphenol-A (BPA) and dibutyl phthalate (DBP) that are leached from the daily used plastic products. Previous studies have demonstrated their potential in pancreatic beta cell injury and diabetes induction. The study hypothesized that both compounds would affect the pancreatic alpha cells in albino rats when administered at environmentally relevant doses. Heat shock protein 60 (HSP60) and caspase-3 protein expression was also investigated as potential mechanisms. Thirty-six male Wistar albino rats were separated into four equal groups: control, BPA alone, DBP alone, and BPA + DBP combined groups. BPA and DBP were given in drinking water for 45 days in a dose of 4.5 and 0.8 µg/L, respectively. Fasting blood glucose, serum insulin, pancreatic tissue levels of malondialdehyde, and superoxide dismutase were measured. Pancreatic sections were subjected to hematoxylin & eosin (H & E) staining, glucagon, HSP60, and caspase-3 immunohistochemistry. Although all three experimental groups showed diffuse islet cell HSP60 immunoreactivity, rats exposed to BPA alone showed α-cell-only apoptosis, indicated by H & E changes and caspase-3 immunoreactivity, associated with reduced glucagon immunoreaction. However, rats exposed to DBP alone showed no changes in either α or β-cells. Both combined-exposed animals displayed α and β apoptotic changes associated with islet atrophy and reduced glucagon expression. In conclusion, the study suggested HSP60/caspase-3 interaction, caspase-3 activation, and initiation of apoptosis in α-cell only for BPA-alone exposure group, meanwhile DBP alone did not progress to apoptosis. Interestingly, both α/β cell effect was observed in the mixed group implying synergetic/additive action of both chemicals when combined.

Integrating transcriptome and physiological analysis to reveal the essential responses of Daphnia magna to antimony trioxide nanoparticle

Antimony (Sb) pollution has already posed a severe threat to the aquatic ecosystem. However, the toxicity mechanisms of Sb on aquatic organisms are far from being elucidated. One of the crucial questions remaining unresolved is the characterization of molecular toxicity of Sb(III). Transcriptomics profiling combined with physiological characterizations was applied to investigate the response of Daphnia magna to nano-size antimony trioxide (nATO) and its soluble Sb(III) counterpart antimony potassium tartrate (APT) in the present study. Both nATO and APT induced the formation of oxidative stress, enhanced the activities of anti-oxidative enzymes, altered the metabolism of xenobiotics, increased the concentration of hydrogen sulfide (H₂S) and nitric oxide (NO), and triggered the self-protection mechanisms such as ubiquitin-mediated proteolysis. In addition, nATO and APT caused damage to the nervous system of D. magna, inhibited its locomotion and nutrient uptake in a concentration-dependent manner. Moreover, nATO exposure enhanced the autophagy activity, reflected by the up-regulated expression of hypoxia-inducible factor-1α, calmodulin-dependent protein kinase-β, and inositol-requiring enzyme 1. The present study, for the first time, depicted a global map of cellular response to nATO, provided essential information on Sb(III) toxicity to aquatic organisms, and is of great significance to the development of Sb management strategies.

Role of myo-inositol supplementation against toxicity of excessive dietary copper in Pacific white shrimp Litopenaeus vannamei

Raw materials for making dried shrimp (a type of foodstuff) are mostly from farmed shrimp and preliminary findings indicated that head copper (Cu) concentrations in some commercial dried shrimp products exceeded the safe limit specified in pollution-free aquatic products (50 mg/kg), which may influence food safety. Therefore, a 63-day feeding trial was conducted to explore effects of dietary Cu concentrations on accumulation of Cu in tissues, growth performance, immune response and antioxidant status of Pacific white shrimp (Litopenaeus vannamei). Moderating effect of myo-inositol (MI, adding 200 mg/kg diet) on the adverse impacts caused by excessive dietary Cu was also investigated. 600 shrimp (initial weight: 0.89 ± 0.00 g) were divided into five groups: 37.08 mg Cu/kg diet group (control group), 62.57 mg Cu/kg diet group, 125.99 mg Cu/kg diet group, 63.41 mg Cu/kg diet group (supplemented with MI) and 119.19 mg Cu/kg diet group (supplemented with MI). The results showed that dietary Cu concentrations increased from 37.08 to over 62.57 mg/kg, hepatopancreas Cu concentrations raised from 29.04 to 233.43-263.65 mg/kg, and muscle Cu concentrations only increased from 6.22 to 6.99-8.39 mg/kg. Report to control group, excessive Cu concentration (125.99 mg/kg) didn't significantly affect growth performance, but it notably reduced whole body lipid content and immune response, induced oxidative stress and damaged the hepatopancreas structure, which was ameliorated by MI supplementation. The results suggested that consuming shrimp head and its processed products weren't recommended. Cu concentrations of commercial feeds for Pacific white shrimp should be controlled below 62.57 mg/kg. Additionally, MI supplementation mitigated the negative impacts induced by excessive dietary Cu.

Transcriptome Analysis to Study the Molecular Response in the Gill and Hepatopancreas Tissues of Macrobrachium nipponense to Salinity Acclimation

Macrobrachium nipponense is an economically important prawn species and common in Chinese inland capture fisheries. During aquaculture, M. nipponense can survive under freshwater and low salinity conditions. The molecular mechanism underlying the response to salinity acclimation remains unclear in this species; thus, in this study, we used the Illumina RNA sequencing platform for transcriptome analyses of the gill and hepatopancreas tissues of M. nipponense exposed to salinity stress [0.4‰ (S0, control group), 6‰ (S6, low salinity group), and 12‰ (S12, high salinity group)]. Differentially expressed genes were identified, and several important salinity adaptation-related terms and signaling pathways were found to be enriched, such as “ion transport,” “oxidative phosphorylation,” and “glycometabolism.” Quantitative real-time PCR demonstrated the participation of 12 key genes in osmotic pressure regulation in M. nipponense under acute salinity stress. Further, the role of carbonic anhydrase in response to salinity acclimation was investigated by subjecting the gill tissues of M. nipponense to in situ hybridization. Collectively, the results reported herein enhance our understanding of the mechanisms via which M. nipponense adapts to changes in salinity.

Transcriptome analysis of acute high temperature-responsive genes and pathways in Palaemon gravieri

Temperature is an important variable factor in aquaculture which affects the health, survival, behavior, growth, and development of aquatic animals. Palaemon gravieri is one of the main economic shrimps in marine capture fisheries of the East China Sea and the South China Yellow Sea; however, it cannot tolerate high temperatures, thereby, resulting in unsuccessful large-scale farming. Thus far, there are few studies on the effects of acute high temperature on P. graviera. Therefore, it is especially important to study the effects of temperature fluctuations, especially acute high temperature, on P. gravieri. In this study, P. gravieri was treated with acute high-temperature stress, which gradually rose from 15 °C to 30 °C in 3 h, then remained at 30 °C for 12 h. The hepatopancreas of shrimps from five time points was collected once at 15 °C and thereafter, every 3 h after 30 °C. The samples of G0, G1, and G4 were selected for transcriptome analysis. A total of 18,308 unigenes were annotated, of which 7744 were differentially expressed. Most differentially expressed genes (DEGs) come from several physiological and biochemical processes, such as metabolism (GRHPR, ALDH5A1, GDH), immunity (HSP70, Rab5B, Rab10, CASP7), and stress-related process (UGT, GST, HSP60, HSP90). The results indicated that acute high temperature significantly reduced the metabolic capacity of shrimp but enhanced the immune capacity, which seemed to be an emergency metabolic compensation technique to resist stress. This study contributes to ongoing research on the physiological mechanism of P. gravieri response to acute high temperature.

Structure, gene expression, and putative functions of crustacean heat shock proteins in innate immunity

Heat shock proteins (HSPs) are molecular chaperones with critical roles in the maintenance of cellular proteostasis. HSPs, which regulate protein folding and refolding, assembly, translocation, and degradation, are induced in response to physiological and environmental stressors. In recent years, HSPs have been recognized for their potential role in immunity; in particular, these proteins elicit a variety of immune responses to infection and modulate inflammation. This review focuses on delineating the structural and functional roles of crustacean HSPs in the innate immune response. Members of crustacean HSPs include high molecular weight HSPs (HSP90, HSP70, and HSP60) and small molecular weight HSPs (HSP21 and HSP10). The sequences and structures of these HSPs are highly conserved across various crustacean species, indicating strong evolutionary links among this group of organisms. The expression of HSP-encoding genes across different crustacean species is significantly upregulated upon exposure to a wide range of pathogens, emphasizing the important role of HSPs in the immune response. Functional studies of crustacean HSPs, particularly HSP70s, have demonstrated their involvement in the activation of several immune pathways, including those mediating anti-bacterial resistance and combating viral infections, upon heat exposure. The immunomodulatory role of HSPs indicates their potential use as an immunostimulant to enhance shrimp health for control of disease in aquaculture.

Identification of co-chaperone Cdc37 in Penaeus monodon: coordination with Hsp90 can reduce cadmium stress-induced lipid peroxidation

Cell division cycle 37 (Cdc37) is an important cytoplasmic phosphoprotein, which usually functions as a complex with heat shock protein 90 (Hsp90), to effectively reduce the damage caused by heavy metals, such as cadmium (Cd), in aquatic animals. The high toxicity of Cd in aquatic systems generally has a deleterious effect on healthy farming of shrimps. In the present study, a novel Cdc37 gene from Penaeus monodon was identified and designated as PmCdc37. Following exposure to Cd stress, the expression levels of PmCdc37 were upregulated at the transcriptional level in both the hepatopancreas and hemolymph. RNA interference and recombinant protein injection experiments were carried out to determine the function of PmCdc37 in P. monodon following Cd exposure. To clarify the correlations between PmCdc37 and PmHsp90, the respective recombinant proteins were expressed in vitro, and the ATPase activity of PmHsp90, with or without PmCdc37, was assessed. Moreover, a pull-down assay was conducted to detect the correlation between PmCdc37 and PmHsp90. After analyzing the expression patterns of PmHsp90 following Cd challenge, whether PmHsp90 can promote the ability of PmCdc37 to resist Cd stress or not was investigated. The results showed that formation of a PmHsp90/PmCdc37 complex protected shrimp against Cd stress-induced damage. Moreover, we also confirmed that PmSOD is involved in Cd stress, and that the PmHsp90/PmCdc37 complex can regulate SOD enzymatic activity. PmSOD was involved in decreasing the MDA content in shrimp hemolymph caused by Cd stress. We concluded that during exposure to Cd, the PmHsp90/PmCdc37 complex increases SOD enzyme activity, and in turn decreases the MDA content, thereby protecting shrimp against the damage caused by Cd stress. The present studies contribute to understanding the molecular mechanism underlying resistance to Cd stress in shrimp.

Molecular cloning and characterization of HSP60 gene in domestic pigeons (Columba livia) and differential expression patterns under temperature stress

Heat shock protein 60 (HSP60) is a well-recognized multifunctional protein, playing a substantial role in protecting organisms from environmental stress. The domestic pigeon (Columba livia) is a promising model organism, with important economic and ecological value, and its health is susceptible to temperature stress. To explore the molecular characteristics, tissue expression profile, and response to temperature stress for HSP60 of Columba livia (ClHSP60), we firstly cloned and characterized the complete cDNA sequence and investigated its expression profile under optimal conditions and acute temperature stress. The cDNA of ClHSP60 contained 2257 nucleotides, consisting of 12 exons with length ranging from 65 to 590 bp. The open reading frame (ORF) encoded 573 amino acids with calculated molecular weight of 60.97 kDa that contained a number of structurally prominent domains or motifs. Under optimal temperature conditions, levels of ClHSP60 expression differed between all the tested tissues (the highest was noted in liver and the lowest in pectoralis major muscle). Under acute temperature stress, five patterns of change were detected in the tested tissues, suggesting that different tissues in domestic pigeons differentially responded to various temperature stress conditions. Upregulation of ClHSP60 expression was highest in the lung and pectoralis major muscle, reflecting the crucial role of these two tissues in temperature regulation. However, the crop, cerebrum, and heart showed little change or decreased ClHSP60 expression. The results indicate that ClHSP60 may be sensitive to and play pivotal roles in responding to acute temperature stress.

Novel 2-Cys Peroxiredoxin gene confers biotic and abiotic stress resistance in Penaeus monodon

Peroxiredoxins (Prxs) are crucial antioxidant proteins that protect against biotic and abiotic stresses in many organisms, ranging from bacteria to mammals. In the present work, a novel 2-Cys Peroxiredoxin gene (PmPrxn), which contains a 153 bp 5'-terminal untranslated region (5'-UTR), a 636 bp open reading frame encoding a protein with 211 amino acids, and an 898 bp 3'-UTR, was successfully identified and characterized in the black tiger shrimp, Penaeus monodon. Tissue-specific expression analysis revealed that the PmPrxn mRNA was ubiquitously expressed and was comparatively highly expressed in the hepatopancreas. To explore the immunity-related and anti-stress roles of PmPrxn, the gills and hepatopancreas were chosen as target tissues in P. monodon and challenged with Vibrio harveyi, Streptococcus agalactiae, and toxic environmental stressors. The results indicate that PmPrxn might play a vital role in response to biotic and abiotic stresses. Furthermore, the antimicrobial and heavy metal toxicity stress-resistance properties of PmPrxn were evaluated and investigated in vitro using a prokaryotic expression system. These results provide useful information that will help further understand the functional mechanisms of PmPrxn in the defense against bacterial pathogens and environmental acute stresses in shrimp.

Effects of Dietary Clostridium butyricum on the Growth, Digestive Enzyme Activity, Antioxidant Capacity, and Resistance to Nitrite Stress of Penaeus monodon

The present study investigated the effects of the dietary probiotic Clostridium butyricum (CB) on the growth, intestine digestive enzyme activity, antioxidant capacity and resistance to nitrite stress, and body composition of Penaeus monodon. For 56 days, shrimps were fed diets containing different levels of C. butyricum (1 × 10⁹ CFU g^-1), 0% (control), 0.5% (CB1), 1.0% (CB2), and 2.0% (CB3), as treatment groups, followed by an acute nitrite stress test for 48 h. The results indicated that dietary supplementation of C. butyricum increased the growth of shrimp in the CB2 and CB3 groups. The survival rate of shrimp increased after nitrite stress for 24 and 48 h. The intestine amylase and trypsin activities increased in all three C. butyricum groups, while the lipase activity was only affected in the CB3 group. The superoxide dismutase (SOD) activity as well as heat shock protein 70 (hsp70) and ferritin gene expression levels were increased in the intestines of shrimps cultured under normal conditions for 56 days, while the catalase (CAT) activity was not changed and glutathione peroxidase (GPx) activity was only increased in the CB2 and CB3 groups. After exposure to nitrite stress for 24 and 48 h, the intestine antioxidant enzyme (SOD, CAT, and GPx) activity and gene (hsp70 and ferritin) expression levels in the three C. butyricum groups were higher than those of the control. C. butyricum had no effects on the whole body composition of the shrimp. These results revealed that C. butyricum improved the growth as well as enhanced the intestine digestive enzyme and antioxidant activities of P. monodon against nitrite stress, and C. butyricum may be a good probiotic for shrimp aquaculture.

Protection of teprenone against hypoxia and reoxygenation stress in stomach and intestine of Lateolabrax maculatus

Teprenone (geranylgeranylacetone) is one kind of safe and effective agent in gastrointestinal mucosa, which have been widely used in human and veterinary, but rarely used in aquaculture animals. In this study, Lateolabrax maculatus, an important economic fish species in southern China, was taken as the object of study to investigate the protective effect of teprenone on intestinal stress. The present study was designed to investigate the potential mechanism underlying the protection offered by teprenone to protect the gastrointestinal tract against hypoxia and reoxygenation injury of L. maculatus. (a) For oxidative stress parameters, SOD, CAT, and T-AOC in control group were higher than those in teprenone group. MDA content was significantly higher than that in teprenone group at N and 12h time points in intestine (P < 0.05), and at 12, 24, and 48 h time points in stomach. (b) For immune-associated proteins, LZM activity in the control group was lower than that in the teprenone group, and the difference between the two groups in stomach and intestine was significant at 12.48 h and 6.48 h time points, respectively (P < 0.05). Compared with time point N, the content of HSP70 in the control group increased at 0 h in intestine. At 0-48 h, intestine HSP70 content in the control group showed a gradually decreasing trend, which was higher than that in the teprenone group. (c) For apoptosis-related factors, the activity of Cyt-C, caspase9, and caspase3 increased first and then decreased in both groups. The content of Cyt-C in the control group was significantly higher than that in the teprenone group at N-3.6 h, and 3.48 h time points in stomach and intestine, respectively (P<0.05). The activity of caspase9 and caspase3 was higher than that in the teprenone group at N-48 h. Results indicated that acute hypoxia and reoxygenation cause the expression levels of oxidative stress and apoptosis-related factors in the stomach and intestine increased first and then decreased within 0-48 h. Acute hypoxia and reoxygenation also that causes the level of nonspecific immunity decreased first and then increased. A total of 400-mg/kg treatment of teprenone can protect stomach and intestinal tissues to a certain extent. It can effectively protect oxidative stress and apoptosis within 0-48 h after acute hypoxia and reoxygenation and enhance non-specific immunity.

Role of HSP60/HSP10 in Lung Cancer: Simple Biomarkers or Leading Actors?

Cancers are one of the major challenges faced by modern medicine both because of their impact in terms of the amount of cases and of the ineffectiveness of therapies used today. A concrete support to the fight against them can be found in the analysis and understanding of the molecular mechanisms involving molecular chaperones. In particular, HSP60 and HSP10 seem to play an important role in carcinogenesis, supporting tumours in their proliferation, survival, and metastasis. Efforts must be directed toward finding ways to eliminate or block this "mistaken" chaperone. Therefore, the scientific community must develop therapeutic strategies that consider HSP60 and HSP10 as the possible target of an anti-tumoural treatment and not only as diagnostic biomarkers, since they contribute to the evolution of pre-cancerous respiratory pathologies in lung tumours. HSP60 acts at the mitochondrial, cytoplasmic, and extracellular levels in the development of cancer pathologies. The molecular mechanisms in which these chaperones are involved concern cell survival, the restoration of a condition of absence of replicative senescence, the promotion of pro-inflammatory environments, and an increase in the ability to form metastases. In this review, we will also present examples of interactions between HSP60 and HSP10 and different molecules and ways to exploit this knowledge in anticancer therapies for lung tumours. In order to improve not only chances for an earlier diagnosis but also treatments for patients suffering from this type of disease, chaperones must be considered as key agents in carcinogenesis and primary targets in therapeutics.

Cross talk between heat shock protein 10 and a heat shock factor identified from Marsupenaeus japonicus

Heat shock factors (HSFs) and heat shock proteins (HSPs) are crucial regulators and effectors of the heat shock response (HSR). In this study, the full-length cDNA sequences of MjHSP10 and MjHSF1 were cloned by rapid amplification of cDNA ends (RACE). The deduced MjHSP10 and MjHSF1 amino acid (aa) sequences exhibited conserved structures and the functional features of HSP10 and HSF1, respectively. The tissue distributions and mRNA expression profiles of the two genes in response to heat stress were analyzed by quantitative real-time PCR (qRT-PCR). MjHSP10 and MjHSF1 were ubiquitously expressed in various tissues. Heat stress induced a significant increase in MjHSP10 expression that tend to positively correlate with temperature. Additionally, MjHSF1 transcription was up-regulated less than MjHSP10 transcription under heat stress. MjHSF1 expression in the hepatopancreas was up-regulated under only long-term (48 h) heat stress, and MjHSF1 transcription in the gill increased under only acute (34 °C) heat stress. MjHSF1 knockdown by RNA interference (RNAi) down-regulated MjHSP10 expression. Glutathione-S-transferase (GST) pull-down assays showed an interaction between MjHSP10 and the DNA-binding domain (DBD) of MjHSF1. This study provided new insights into cross talk between HSP10 and HSF1 in Marsupenaeus japonicus.

RNA-seq revealed the signatures of immunity and metabolism in the Litopenaeus vannamei intestine in response to dietary succinate

The intestine is important for nutrition, metabolism and immunity. Succinate (SA) plays a vital role in the physiological homeostasis of animal intestines. However, the effects of dietary SA on the intestinal immunity and metabolism in shrimp are not clear. In this study, we investigated the immune and metabolic responses in the intestine of Litopenaeus vannamei that were fed diets consisting of different levels of SA: 0 g/kg (Con) and 10 g/kg (SA) for 56 days. The results from a RNA-seq analysis identified 6005 differentially expressed genes (DEGs), including 2728 upregulated genes and 3277 downregulated genes, which were grouped into 312 pathways. The DEGs were most enriched in pathways related to protein synthesis and amino acid metabolism, including "ribosome", "aminoacyl-tRNA biosynthesis", "pyrimidine metabolism", and "arginine and proline metabolism"; additionally, carbohydrate and lipid metabolism pathways were also activated. A large number of immune-related genes were associated with mucus barrier modification, antimicrobial activity, pathogen attachment and recognition, antioxidant activity, and apoptosis. The expression patterns of several candidate genes involved in the immune response and nutrition metabolism were detected by qPCR. This study provides insight into the transcriptomic modulating mechanisms associated with intestinal immunity and the metabolism of L. vannamei in response to the intake of dietary SA.

Effects of dietary anthocyanin on innate immune parameters, gene expression responses, and ammonia resistance of Nile tilapia (Oreochromis niloticus)

The present study investigated the effects of dietary anthocyanin on the growth performance, haematological, non-specific immune, and spleen gene expression responses of Nile tilapia, Oreochromis niloticus. Five experimental groups of fish with mean weights of 8.24 ± 0.64 g were used in the study; four of these were fed with diets incorporating anthocyanin (20 mg kg -¹, 40 mg kg^-1, 80 mg kg^-1 and 160 mg kg^-1), while the fifth was a control group without dietary anthocyanin. Growth performance and haematological parameters of tilapia were not affected by anthocyanin-supplemented diets (p > 0.05). Dietary anthocyanin significantly increased respiratory burst activity, phagocytic activity, phagocytic index, lysozyme activity, myeloperoxidase activity, serum total superoxide dismutase (T.SOD) activity, and serum catalase (CAT) activity (p < 0.05). The total immunoglobulin level was highest in the 80 mg kg^-1 group compared with the other groups (p < 0.05). In addition, with the anthocyanin-containing diets, the gene levels of interleukin 1, beta (IL-1β), interleukin 8 (IL-8), tumor necrosis factor (TNF-α), heat shock protein 70 (HSP70), and interferon gamma (IFN-γ) were increased in the fish spleen, and the gene levels of CAT, GPx, and SOD were also increased in fish liver (p < 0.05). At the end of the experiment, the fish were subjected to ammonia stress. The groups fed with 20 and 40 mg kg^-1 anthocyanin exhibited higher survival rates than the other groups. In summary, feeding Nile tilapia with anthocyanin-containing diets caused increases in the innate immune parameters, gene expression responses, and the survival rate of the fish subjected to ammonia stress.

Changes in the intestine barrier function of Litopenaeus vannamei in response to pH stress

pH of water environment affects the survival of aquatic animals. Intestine barrier function influences the health of animals, which is related to its mucosa structure, immune components, and microbial communities. In this study, we investigated the histological structure, digestive and metabolic capacity, immune responses, and microbial composition in the intestine of Litopenaeus vanmei under three different conditions: control (pH 8.3), low pH stress (pH 6.9), and high pH stress (pH 9.7) for 72 h. The results showed both low and high pH stress disrupted the intestine morphological structure, and induced variations in the activities of digestive (AMS, LPS, Tryp, and Pep) and metabolic (HK, PK, CCO, and LDH) enzymes. Low and high pH stress also increased oxidative stress (MDA, LPO, PC, and ·O₂^- generation), and decreased the antioxidant enzyme activities (T-AOC, SOD, and GST); shrimp enhanced CAT activity and HSP70, Trx, MT and Fer gene transcripts as defense mechanism. Additionally, Immune confusion was also found in the shrimp intestine in response to low and high pH stress, including the antibacterial ability (T-NOS, PO, proPO, ALF, and Lys), pathogen recognition (TLR and Lec), apoptosis (Casp, IAP and p53), and mucus homeostasis (Muc-1, Muc-2, Muc-5AC, Muc-5B, and Muc-19). pH exposure also decreased the diversity of the intestine bacterial, disturbed the composition of microbiota, and decreased the microbial metabolite SCFA contents. Our results indicated that acute pH stress can impair the intestine barrier function of white shrimp, probably via destroying mucosa structure, confusing digestion and metabolism, inducing oxidative stress, disordering immunity, and disrupting the microbial composition.

Transcriptomic and microbiota response on Litopenaeus vannamei intestine subjected to acute sulfide exposure

Harmful effects of water pollutants are myriad. Sulfide from water bodies affects the aquatic animals. Intestine barrier function serves as the front-line of animals defense. Our previous study confirmed the toxic effect of sulfide on intestine immune response of Litopenaeus vannamei, but the underlying mechanisms remained elusive. Therefore, in this study, we investigated the transcriptomic and microbiota responses of the L. vannamei intestine subjected to acute sulfide exposure. Sulfide decreased bacterial richness and altered the intestine microbiota composition. Specifically, sulfide increased the abundances of Bacteroidetes and Actinobacteria, but decreased the abundance of Proteobacteria. At the genus level, sulfide increased typical cellulolytic characteristics bacteria, such as Formosa, Sphingomonas, and Demequina. RNA-seq analysis identified differential expression of 1799 genes (701 up-regulated and 1098 down-regulated) were grouped into 267 pathways. The most enriched pathway 'amoebiasis' was related to the intestine mucus homeostasis. A number of immune-related genes associated with antimicrobial, antioxidant, pathogen attachment and recognition, and apoptosis processes in contrasting accessions; they were correlated with the abundance of intestine bacterial at the phylum level. This study provides an insight into the mechanisms associated with molecular and microbiota response and processes involved in adaptation strategies towards sulfide stress.

Changes in the intestine microbial, digestion and immunity of Litopenaeus vannamei in response to dietary resistant starch

Resistant starch (RS) is a constituent of dietary fibre that has beneficial effects on the intestine physiological function of animals. However, the roles of RS on shrimp intestine health is unknown. In this study, we investigated the the effects of dietary RS on the microbial composition, and digestive and immune-related indices in the intestine of Litopenaeus vannamei. The shrimp were fed with diets containing different levels of RS: 0 g/kg (Control), 10 g/kg (RS1), 30 g/kg (RS2) and 50 g/kg (RS3) for 56 days. The results showed that dietary RS improved the morphology of the intestine mucosa. RS also increased the activity of digestive enzymes (AMS, LPS, Tryp, and Pep) and immune enzymes (PO, T-AOC, T-NOS, and NO), and the expression levels of immune-related genes (proPO, ALF, Lys, HSP70, Trx, Muc-1, Muc-2, Muc-5AC, Muc-5B, and Muc-19). A microbiome analysis indicated that dietary RS increased the short-chain fatty acids (SCFAs) contents and altered the composition of the intestine microbial. Specifically, RS increased the abundances of Proteobacteria and decreased the abundance of Bacteroidetes. At the genus level, the beneficial bacteria (Lutimonas, Ruegeria, Shimia, Mesoflavibacter, and Mameliella) were enriched, which might be involved in degrading toxins and producing beneficial metabolites; while potential pathogens (Formosa and Pseudoalteromonas) were decreased in response to dietary RS. Our results revealed that dietary RS could improve the intestine health of L. vannamei, probably via modulating the intestine microbial composition and SCFAs contents, and enhancing the digestion and immunity of the shrimp.

Effects of environmental stress on shrimp innate immunity and white spot syndrome virus infection

The shrimp aquaculture industry is plagued by disease. Due to the lack of deep understanding of the relationship between innate immune mechanism and environmental adaptation mechanism, it is difficult to prevent and control the diseases of shrimp. The shrimp innate immune system has received much recent attention, and the functions of the humoral immune response and the cellular immune response have been preliminarily characterized. The role of environmental stress in shrimp disease has also been investigated recently, attempting to clarify the interactions among the innate immune response, the environmental stress response, and disease. Both the innate immune response and the environmental stress response have a complex relationship with shrimp diseases. Although these systems are important safeguards, allowing shrimp to adapt to adverse environments and resist infection, some pathogens, such as white spot syndrome virus, hijack these host systems. As shrimp lack an adaptive immune system, immunization therapy cannot be used to prevent and control shrimp disease. However, shrimp diseases can be controlled using ecological techniques. These techniques, which are based on the innate immune response and the environmental stress response, significantly reduce the impact of shrimp diseases. The object of this review is to summarize the recent research on shrimp environmental adaptation mechanisms, innate immune response mechanisms, and the relationship between these systems. We also suggest some directions for future research.

Heat Shock Protein 40 (HSP40) in Pacific White Shrimp (Litopenaeus vannamei): Molecular Cloning, Tissue Distribution and Ontogeny, Response to Temperature, Acidity/Alkalinity and Salinity Stresses, and Potential Role in Ovarian Development

Heat shock proteins (HSPs), a family of conserved proteins that are produced by cells in response to stresses, are known as molecular chaperones with a range of housekeeping and cellular protective functions. The 40 kD heat shock protein (HSP40) is a co-chaperone for HSP70 in the regulation of ATP hydrolysis. Unlike its well-documented cofactor HSP70, little is currently known regarding the biological functions of HSP40 in crustacean species such as penaeid shrimp. In the present study, the cDNA encoding HSP40 (Lv-HSP40) was identified from the Pacific white shrimp Litopenaeus vannamei, a highly significant commercial culture species. The structural organization indicates that Lv-HSP40 belongs to the type-I HSP40s. The muscle, gill, and hepatopancreas are the main sites of Lv-HSP40 transcript expression. Within these tissues, Lv-HSP40 mRNA were predominantly exhibited in the myocytes, epithelial cells and hepatopancreatic cells, respectively. Under acute thermal stress in the culture environment, Lv-HSP40 transcript levels are significantly induced in these three tissues, while low pH stress only upregulates Lv-HSP40 mRNA in the hepatopancreas and gill. During ontogenesis, Lv-HSP40 transcript levels are high at early embryonic stages and drop sharply at late embryonic and early larval stages. The ovary is another major organ of Lv-HSP40 mRNA expression in female shrimp, and Lv-HSP40 transcripts were mainly presented in the follicle cells but only weekly detected in the oocytes. Ovarian Lv-HSP40 mRNA levels increase continuously during gonadal development. Silencing of the Lv-HSP40 gene by RNA interference may effectively delay ovarian maturation after unilateral eyestalk ablation. The roles of Lv-HSP40 in ovarian development are speculated to be independent of its cofactor HSP70, and the vitellogenesis factor vitellogenin (Vg) and vitellogenin receptor (VgR). Our study, as a whole, provides new insights into the roles of HSP40 in multiple physiological processes in L. vannamei: (1) HSP40 is a responding factor during stressful conditions; and (2) HSP40 participates in embryonic and ovarian development.

Identification of microRNAs with heat stress responsive and immune properties in Marsupenaeus japonicus based on next-generation sequencing and bioinformatics analysis: Essential regulators in the heat stress-host interactions

Summer mortality syndrome is one of the most serious issue for Marsupenaeus japonicus aquaculture in China. Since it causes massive economic loss and threatens sustainability of M. japonicus aquaculture industry, thus, there is an urgent desire to reveal the heat stress-host interactions mechanisms that lead to mass mortalities of M. japonicus in hot summer months. MicroRNAs (miRNAs) are small noncoding RNAs that involved in regulation of diverse biological processes, including stress and immune response, and might serve as potential regulators in the heat stress-host interactions. In the present study, miRNAs with heat stress responsive and immune properties were identified and characterized in M. japonicus by small RNA sequencing and bioinformatics analysis. In total, 79 host miRNAs were identified, among which 15 miRNAs were differentially expressed in response to heat stress. Target genes prediction and function annotation revealed that a variety of host cellular processes, such as signal transduction, transcription, anti-stress response, ribosomal biogenesis, lipid metabolism, cytoskeleton, etc, were potentially subject to miRNA-mediated regulation in response to heat stress. Furthermore, a total of 30 host miRNAs that potentially involved in interaction with white spot syndrome virus (WSSV) were obtained via predicting and analyzing the target genes from WSSV. The results showed that a batch of WSSV genes that code for structural proteins and enzymes that are essential for WSSV infection and proliferation, such as envelope proteins, capsid proteins, immediate-early proteins, collagen-like protein, protein kinase, thymidylate synthetase, TATA-box bind protein, etc, were predicted to be targeted by host miRNAs. Several of the host miRNAs with predicted antiviral capacity were down-regulated under heat stress, indicating a repression of host miRNA-mediated antiviral immune response. This study highlighted the essential roles of host miRNAs in the heat stress-host interactions and provided valuable information for further investigation on the mechanism of miRNA-mediated heat stress and immune response of shrimp.

The acute stresses role of the atypical 2-cys peroxiredoxin PmPrx5 in black tiger shrimp (Penaeus monodon) from biological immunity and environmental toxicity stress

As a unique atypical 2-Cys Peroxiredoxin (Prx) of the Prx-like superfamily, Peroxiredoxin5 (Prx5) possesses special properties, such as its enzymatic mechanism, wide subcellular distribution and high affinity for peroxides and peroxynitrite. Prx5 plays a crucial role in oxidative stress, immune responses, cell apoptosis, proliferation, differentiation, intracellular signaling, the modulation of gene expression, ecdysis, etc. In this paper, we obtained a full-length Prx5 cDNA sequence (designated PmPrx5) from black tiger shrimp (P. monodon). The full-length PmPrx5 cDNA sequence was 1686 bp containing a 5' untranslated region (UTR) of 76 bp with two nucleotide sequences (AAA), a 3' UTR of 1040 bp with a poly (A) tail and two canonical polyadenylation signal sequences (AATAAA), and an open reading frame of 570 bp encoding 189 amino acid residues with a predicted molecular mass of 20 kDa and a theoretical isoelectric point of 6.29. Phylogenetic trees and multiple sequence alignment showed that the PmPrx5 had strong homology with Prx5 proteins from other species, such as similarity with Palaemon carinicauda (69%) and Macrobrachium rosenbergii (69%), containing the highly conserved functional domain. PmPrx5 mRNA was ubiquitously detected in all tested tissues. After P. monodon was exposed to pathogenic bacteria, osmotic pressure, acidity and alkalinity and the heavy metal, the mRNA expression of PmPrx5 in the gills and hepatopancreas was significantly enhanced (P < 0.01) because of the immune response and declined with heavy metal copper and cadmium challenges as time progressed. The recombinant PmPrx5 protein purified in E. coli (DE3) was further confirmed to exhibit antioxidant activity and antibacterial properties to a certain extent using a bacterial growth inhibition test in both liquid and solid cultures in vitro. E. coli transformed with pRSET-PmPrx5 were dramatically protected in response to metal toxicity stress. Thus, PmPrx5 may be developed as a potential therapeutic drug against pathogenic bacteria and as a biomarker for pollutant levels. This work offers useful clues to further explore the functional mechanism of Prx5 in marine shrimp immunity.

Physiological and immune response in the gills of Litopenaeus vannamei exposed to acute sulfide stress

Sulfide is a harmful environmental pollutant that affects the survival and immunity of shrimps. The gill is important for shrimp respiratory and osmotic adjustment, the physiological and immune homeostasis of the organ can be influenced by sulfide. In this study, we investigated the acute toxicity of sulfide (5 mg/L) on the morphology, physiological and immune response in the gills of Litopenaeus vannamei. H&E stain showed that sulfide stress damaged the gills histological structure. Specifically, osmoregulation capacity including of Na⁺/K⁺-ATPase and Ca²⁺/Mg²⁺-ATPase activity was both increased at 6 h and 12 h, and decreased at 72 h; the contents of free amino acid including of Gly, Pro, Ser, Thr and Ala were decreased at 72 h. Respiratory metabolic enzymes, such as cytochrome c oxidase and succcinate dehydrogenase activity was decreased at 12 h-72 h, while fumarate reductase and lactate dehydrogenase activity kept a higher level at 12 h-72 h. Significant variations in the activities of immune enzymes (acid phosphatase, alkaline phosphatase, total antioxidant capacity and lysozyme). The expression of immune-related genes (heat shock protein 70, thioredoxin and caspase-3) was increased at first and then decreased, while hypoxia inducible factor 1α kept a higher level at 6 h-72 h. These results revealed that sulfide stress influenced the L. vannamei gills physiological and immune function by damaging histological structure, and confusing osmoregulation, respiratory metabolic and immune capacity.

Regulation of Antimicrobial Pathways by Endogenous Heat Shock Proteins in Gastrointestinal Disorders

Heat shock proteins (HSPs) are essential mediators of cellular homeostasis by maintaining protein functionality and stability, and activating appropriate immune cells. HSP activity is influenced by a variety of factors including diet, microbial stimuli, environment and host immunity. The overexpression and down-regulation of HSPs is associated with various disease phenotypes, including the inflammatory bowel diseases (IBD) such as Crohn’s disease (CD). While the precise etiology of CD remains unclear, many of the putative triggers also influence HSP activity. The development of different CD phenotypes therefore may be a result of the disease-modifying behavior of the environmentally-regulated HSPs. Understanding the role of bacterial and endogenous HSPs in host homeostasis and disease will help elucidate the complex interplay of factors. Furthermore, discerning the function of HSPs in CD may lead to therapeutic developments that better reflect and respond to the gut environment.

Changes in the Intestine Microbial, Digestive, and Immune-Related Genes of Litopenaeus vannamei in Response to Dietary Probiotic Clostridium butyricum Supplementation

The intestine barrier serves as the front-line defense in shrimp. Clostridium butyricum (CB) can produce butyric acid that provides energy for the intestine epithelial cells of the host. However, the effects of dietary CB on the intestine microbiome and the digestion and immunity of the host is not clear. In this study, we therefore investigated the composition and metabolic activity of the intestine microbiome, and digestive and immune-related gene expression in Litopenaeus vannamei fed with diets containing different levels of CB: basal diet (control), 2.5 × 10⁹ CFU kg^-1 diet (CB1), 5.0 × 10⁹ CFU kg^-1 diet (CB2), and 1.0 × 10¹⁰ CFU kg^-1 diet (CB3) for 56 days. Dietary CB altered the composition of the intestine microbiome. Specifically, the dominant bacterial phylum Proteobacteria was enriched in the CB3 group and weakened in the CB1 and CB2 groups. The Bacteroidetes was enriched in the CB1 and CB2 groups and weakened in the CB3 group. The Firmicutes was enriched in all three CB groups. At the genus level, the potential pathogen (Desulfovibrio and Desulfobulbus) were weakened, and beneficial bacteria (Bacillus, Clostridium, Lachmoclostridium, Lachnospiraceae, and Lactobacillus) were enriched in response to dietary CB; these might contribute to the expression of the host digestive genes (α-amylase, lipase, trypsin, fatty acid-binding protein, and fatty acid synthase) and immune-related genes (prophenoloxidase, lipopolysaccharide and β-1,3-glucan binding protein, lysozyme, crustin, and superoxide dismutase). Additionally, CB enhanced the bacterial metabolism, especially that of carbohydrates, polymers, amino acids, carboxylic acids, and amines. These results revealed that dietary CB had a beneficial effect on the intestine health of L. vannamei by modulating the composition of the intestine microbiome, enhancing the microbial metabolism activity, and promoting the digestion and immunity of the host. The optimal dietary supplementation dosage was found to be 5.0 × 10⁹ CFU kg^-1 in the diet.

Molecular characterization and expression of six heat shock protein genes in relation to development and temperature in Trichogramma chilonis

Trichogramma is a kind of egg parasitoid wasp that is widely used to control lepidopterous pests. Temperature is one of the main factors that determines the various life activities of this species, including development, reproduction and parasitism efficiency. Heat shock proteins (HSPs) are highly conserved and ubiquitous proteins that are best known for their responsiveness to temperature and other stresses. To explore the potential role of HSPs in Trichogramma species, we obtained the full-length cDNAs of six HSP genes (Tchsp10, Tchsp21.6, Tchsp60, Tchsp70, Tchsc70-3, and Tchsp90) from T. chilonis and analyzed their expression patterns during development and exposure to temperature stress. The deduced amino acid sequences of these HSP genes contained the typical signatures of their corresponding protein family and showed high homology to their counterparts in other species. The expression levels of Tchsp10, Tchsp21.6 and Tchsp60 decreased during development. However, the expression of Tchsc70-3 increased from the pupal stage to the adult stage. Tchsp70 and Tchsp90 exhibited the highest expression levels in the adult stage. The expression of six Tchsps was dramatically upregulated after 1 h of exposure to 32 and 40°C but did not significantly change after 1 h of exposure to 10 and 17°C. This result indicated that heat stress, rather than cold stress, induced the expression of HSP genes. Furthermore, the expression of these genes was time dependent, and the expression of each gene reached its peak after 1 h of heat exposure (40°C). Tchsp10 and Tchsp70 exhibited a low-intensity cold response after 4 and 8 h of exposure to 10°C, respectively, but the other genes did not respond to cold at any time points. These results suggested that HSPs may play different roles in the development of this organism and in its response to temperature stress.

Identification of MicroRNAs and Their Target Genes Associated with Ovarian Development in Black Tiger Shrimp (Penaeus monodon) Using High-Throughput Sequencing

Plenty of evidence showing that microRNAs (miRNAs) post-transcriptionally regulate gene expression and are involved in a wide range of biological processes. However, the roles of miRNAs in ovarian development process remain largely unknown in shrimp. In the present study, high-throughput sequencing of small RNAs was performed to find specific miRNAs that are involved in ovarian development process in Penaeus monodon. Two small RNA libraries were constructed from undeveloped (UNDEV group) and developed (DEV group) ovarian tissues in P. monodon. In total, 43 differentially expressed miRNAs were identified between the two groups (P ≤ 0.05, |log2 ratio| ≥1), and their expression profiles were validated by qRT-PCR. In order to further clarify the functional roles of these differentially expressed miRNAs during ovarian development process, target gene prediction was performed. In total, 4,102 target genes of 43 miRNAs were predicted, then clustered by the Kyoto Encyclopedia of Genes and Genomes (KEGG) database; only four specific pathways related to ovarian development were obtained (P < 0.05). Dual-luciferase reporter assays and integrated expression analysis were also conducted to further clarify the interaction between the miRNAs and their target mRNAs. This study provides important information about the function of miRNAs involved in ovarian developmental stages in P. monodon.

Molecular cloning of heat shock protein 10 (Hsp10) and 60 (Hsp60) cDNAs from Galeruca daurica (Coleoptera: Chrysomelidae) and their expression analysis

Galeruca daurica (Joannis) is a new outbreak pest in the Inner Mongolia grasslands in northern China. Heat shock protein 10 and 60 (Hsp10 and Hsp60) genes of G. daurica, designated as GdHsp10 and GdHsp60, were cloned by rapid amplification of cDNA ends techniques. Sequence analysis showed that GdHsp10 and GdHsp60 encoded polypeptides of 104 and 573 amino acids, respectively. Sequence alignment and phylogenetic analysis clearly revealed that the amino acids of GdHsp10 and GdHsp60 had high homology and were clustered with other Hsp10 and Hsp60 genes in insects which are highly relative with G. daurica based on morphologic taxonomy. The mRNA expression analysis by real-time PCR revealed that GdHsp10 and GdHsp60 were expressed at all development stages and in all tissues examined, but expressed highest in eggs and in adults' abdomen; both heat and cold stresses could induce mRNA expression of GdHsp10 and GdHsp60 in the 2nd instar larvae; the two Hsp genes were expressed from high to low with the extension of treatment time in G. daurica eggs exposed to freezing point. Overall, our study provides useful information to understand temperature stress responses of Hsp60 and Hsp10 in G. daurica, and provides a basis to further study functions of Hsp60/Hsp10 relative to thermotolerance and cold hardiness mechanism.

A transcriptome study on Macrobrachium nipponense hepatopancreas experimentally challenged with white spot syndrome virus (WSSV)

White spot syndrome virus (WSSV) is one of the most devastating pathogens of cultured shrimp, responsible for massive loss of its commercial products worldwide. The oriental river prawn Macrobrachium nipponense is an economically important species that is widely farmed in China and adult prawns can be infected by WSSV. However, the molecular mechanisms of the host pathogen interaction remain unknown. There is an urgent need to learn the host pathogen interaction between M. nipponense and WSSV which will be able to offer a solution in controlling the spread of WSSV. Next Generation Sequencing (NGS) was used in this study to determin the transcriptome differences by the comparison of control and WSSV-challenged moribund samples, control and WSSV-challenged survived samples of hepatopancreas in M. nipponense. A total of 64,049 predicted unigenes were obtained and classified into 63 functional groups. Approximately, 4,311 differential expression genes were identified with 3,308 genes were up-regulated when comparing the survived samples with the control. In the comparison of moribund samples with control, 1,960 differential expression genes were identified with 764 genes were up-regulated. In the contrast of two comparison libraries, 300 mutual DEGs with 95 up-regulated genes and 205 down-regulated genes. All the DEGs were performed GO and KEGG analysis, overall a total of 85 immune-related genes were obtained and these gene were groups into 13 functions and 4 KEGG pathways, such as protease inhibitors, heat shock proteins, oxidative stress, pathogen recognition immune receptors, PI3K/AKT/mTOR pathway, MAPK signaling pathway and Ubiquitin Proteasome Pathway. Ten genes that valuable in immune responses against WSSV were selected from those DEGs to furture discuss the response of host to WSSV. Results from this study contribute to a better understanding of the immune response of M. nipponense to WSSV, provide information for identifying novel genes in the absence of genome of M. nipponense. Furthermore, large number of transcripts obtained from this study could provide a strong basis for future genomic research on M. nipponense.

Dietary effects of succinic acid on the growth, digestive enzymes, immune response and resistance to ammonia stress of Litopenaeus vannamei

Organic acids acts as an growth promoter and antimicrobial agent in aquaculture. The present study investigated the effects of a natural organic acid - succinic acid (SA) on the growth, digestive enzymes, immune response and resistance to ammonia stress of Litopenaeus vannamei. The shrimps were firstly fed with diets containing different levels of SA: 0% (Control), 0.25% (SA1), 0.50% (SA2), and 1.0% (SA3) (w/w) for 56 days, followed by an acute ammonia stress for 48 h. The results indicated that dietary of SA improved the growth of shrimp, and increased the survival rate of shrimp after ammonia stress for 48 h. The amylase, lipase and pepsin activity increased in hepatopancreas in three SA group, while trypsin activity was only increased in the SA1 and SA2 groups. At 56 d, T-NOS activity, proPO and HSP70 gene expression level increased in the three SA group, PO activity increased in the SA1 and SA2 groups, T-AOC content and Toll gene expression level increased in the SA2 and SA3 groups, Trx and SOD gene expression level increased in the SA2 group, while Imd, GS and GDH gene expression level was no changes. After exposure to ammonia stress for 48 h, immune biochemical parameters (T-AOC and PO) and genes (proPO, HSP70, Trx and GDH) expression level increased in the three SA group, T-NOS activity, Toll, Imd and GS gene expression level increased in the SA2 and SA3 groups, while SOD gene expression level increased in the SA1 and SA2 groups. These results indicated that SA improved growth, enhanced digestive and immune capacities of L. vannamei against ammonia stress, and may be a potential feed additive for shrimp. The optimal dietary supplementation dosage is 0.50% (w/w) in diet.

HSP60 expression profile under different extreme temperature stress in albino northern snakehead, Channa argus

The great albino northern snakehead, Channa argus, is one of the most important economical fish in China. In the present study, cDNA encoding heat shock protein 60 (HSP60) was cloned and characterized. The cDNA was 2462 bp, containing an open reading frame (ORF) encoding a 575-amino-acids polypeptide of 61.10 kDa (theoretical isoelectric point [pI]: 5.66). BLAST analysis showed that AcaHSP60 was highly similar with other HSP60s, and three conserved amino acid blocks and characteristic motifs or domains defined as HSP60 protein family signatures. Genomic DNA analysis showed that AcaHSP60 had ten exons in the coding region (from 94 to 336 bp). Changes in AcaHSP60 gene expression profiles in albino C. argus experimentally exposed to different temperature stress (8.5, 26, and 37 °C) was investigated. Quantitative real-time PCR and western blot analysis revealed that tissue-specific AcaHSP60 expressions were in the spleen, muscle, liver, kidney, heart and brain. Expression was highly significantly stimulated after heat shock (37 °C), but showed no significant differences after cold treatment (8.5 °C) except in the brain. In summary, these results showed that AcaHSP60 was significantly tissue specific and indicate that AcaHSP60 expression might be sensitive to thermal resistance in albino C. argus.

Genomic structure, expression, and functional characterization of checkpoint kinase 1 from Penaeus monodon

Chk1 is a cell-cycle regulator. Chk1 has been identified in organisms ranging from yeast to humans, but few researchers have studied Chk1 in shrimps. We cloned Chk1 from the black tiger shrimp (Penaeus monodon). The full-length cDNA sequence of PmChk1 had 3,334 base pairs (bp), with an open reading frame of 1,455 bp. The complete genomic sequence of PmChk1 (11,081 bp) contained 10 exons separated by nine introns. qRT-PCR showed that PmChk1 was highly expressed in the ovaries and gills of P. monodon. The lowest PmChk1 expression was noted in stage III of ovarian development in P. monodon. PmChk1 expression decreased significantly after injection of 5-hydroxytryptamine and eyestalk ablation in P. monodon ovaries. RNA interference experiments were undertaken to examine the expression of PmChk1, PmCDC2, and PmCyclin B. PmChk1 knockdown in the ovaries and hepatopancreas by dsRNA-Chk1 was successful. The localization and level of PmChk1 expression in the hepatopancreas was studied using in situ hybridization, which showed that data were in accordance with those of qRT-PCR. The Gonadosomatic Index of P. monodon after dsRNA-Chk1 injection was significantly higher than that after injection of dsRNA-GFP or phosphate-buffered saline. These data suggest that PmChk1 may have important roles in the ovarian maturation of P. monodon.

Heat shock cognate 70 gene in Haliotis diversicolor: responses to pathogen infection and environmental stresses and its transcriptional regulation analysis

Heat shock cognate 70 (HSC70) is a class of highly conserved proteins which functions as a molecular chaperon, participates in tolerance processes, and is involved in protein folding, degradation, targeting, translocation, and protein complex remodeling. In this study, the mRNA expression level of the Haliotis diversicolor HSC70 (HdHSC70) gene was detected by quantitative real-time PCR in different tissues and under different stresses. The results showed that the HdHSC70 gene was ubiquitously expressed in seven selected tissues. The highest expression level was detected in gills (P < 0.05). The expression level of the HdHSC70 gene was significantly upregulated by thermal stress, hypoxia stress, Vibrio parahaemolyticus infection, and combined thermal and hypoxia stress. The upregulation occurred at the early stage of stress. These results indicated that the HdHSC70 is an important component in the immune system of H. diversicolor and is involved in the early stress response. Meanwhile, 5'-flanking region sequence (2013 bp) of the HdHSC70 gene was cloned; it contains a putative core promoter region, heat shock element, CpG, and transcription elements including NF-1, Sp1, Oct-1, interferon consensus sequence binding protein (ICSBP), etc. In HEK 293T cells, the 5'-flanking region sequence is able to drive expression of the enhanced green fluorescent protein (EGFP), proving its promoter function. The promoter activity increased after high-temperature treatment, which may be the immediate reason why the expression of the HdHSC70 gene was significantly upregulated by thermal stress. After the ICSBP-binding site was mutated, we found the luciferase activity significantly reduced, which suggested that the ICSBP-binding site has a certain enhancement effect on the activity of the HdHSC70 promoter.

The anti-stresses capability of GRP78 in Penaeus monodon: Evidence from in vitro and in vivo studies

Glucose-regulated protein 78 (GRP78) is an important member of the heat shock protein 70 (HSP70) family, which plays important roles in the response to stimulation from various external environmental stimuli. In this study, the full-length cDNA of GRP78 (PmGRP78) was cloned from Penaeus monodon. The qRT-PCR analysis showed that PmGRP78 was ubiquitously expressed in all the tested shrimp tissues, and the expression pattern of PmGRP78 in the gill and hepatopancreas tissues after a pH challenge, osmotic stress, and heavy metal exposure was also detected. A chaperone activity assay was performed to study the function of PmGRP78, and the results showed that the recombinant PmGRP78 possesses biological activity and could protect alcohol dehydrogenase (ADH) from denaturing in vitro. To further explore the role played by PmGRP78 in vivo, RNA interference (RNAi) technology was adopted to silence the expression of PmGRP78 in P. monodon, and a cumulative mortality rate assay was carried out. In conclusion, we inferred that PmGRP78 may play important roles in the defence against environmental stresses in P. monodon.

Gene characteristics, immune and stress responses of PmPrx1 in black tiger shrimp (Penaeus monodon): Insights from exposure to pathogenic bacteria and toxic environmental stressors

Peroxiredoxins (Prxs) are ubiquitous, multifunctional and evolutionarily conserved enzymes that can protect cells from oxidative damage caused by ROS and play a vital role in immune responses. Here, a full-length Prx1 cDNA sequence (PmPrx1) was isolated from Penaeus monodon. The PmPrx1 cDNA was 951 base pairs (bp), encoding 198 amino acid polypeptides. The results of qRT-PCR showed that the PmPrx1 mRNA was ubiquitously expressed in all tissues tested and had a comparatively high expression level in immune-associated tissues (gill, hepatopancreas). To explore the immune and anti-stress roles of PmPrx1, the gills and hepatopancreas were chosen as target tissues in Penaeus monodon and were challenged with bacteria (Vibrio harveyi and Streptococcus agalactiae) and toxic environmental stresses. To further clarify the immune function of PmPrx1 after bacterial challenge, the recombinant PmPrx1 protein was acquired using a prokaryotic expression method. The antioxidant activity of the recombinant PmPrx1 was assessed by the catalyzing hydrogen peroxide assay method, and the results showed obvious antioxidant activity in a dose-dependent and temperature-dependent manner. The antimicrobial activity of purified PmPrx1 protein was evaluated and further studied in vitro relying on a bacterial growth inhibition test which was conducted in both liquid and solid cultures. Furthermore, E. coli transferred with pRSET-PmPrx1 was dramatically protected in response to metal toxicity and H₂O₂ oxidative stress. In summary, this study provides useful information about the role of the Prx1 gene in defense against a variety of toxic factors in shrimps that help to further clarify the functional mechanism of Prx.

Heat shock 70 kDa protein cognate 5 involved in WSSV toleration of Litopenaeus vannamei

The expression levels of 97 unigenes encoding heat shock proteins of Litopenaeus vannamei was scanned, and ten of them were significantly induced by white spot syndrome virus (WSSV). Among these genes, heat shock 70 kDa protein cognate 5 (LvHSC70-5) was upregulated to the highest extent and subjected to further studies. Subcellular localization assay revealed that LvHSC70-5 was located in the mitochondria. Aside from WSSV infection, unfolded protein response activation and thermal stress could also upregulate LvHSC70-5. Results of reporter gene assay demonstrated that promoter of LvHSC70-5 was activated by L. vannamei heat shock factor protein 1, activating transcription factor 4 and thermal stress. A decrease in the expression of LvHSC70-5 could reduce the aggregation of proteins in hemocytes and the cumulative mortality of WSSV-infected L. vannamei. LvHSC70-5 in L. vannamei hemocytes was upregulated by mild thermal stress. In addition, mild thermal stress, decreased the copy number of WSSV in shrimp muscle and the cumulative mortality of WSSV-infected L. vannamei. Therefore, collecting results suggested that LvHSC70-5 should be involved in WSSV toleration of shrimp L. vannamei.

Genomic structure, expression pattern, and functional characterization of transcription factor E2F-2 from black tiger shrimp (Penaeus monodon)

Transcription factor E2F-2 is a regulator of cell cycle. Researchers identified E2F-2 genes from yeasts to humans, but few reports investigated E2F-2 gene from black tiger shrimp. In the present study, we cloned E2F-2 gene from black tiger shrimp (Penaeus monodon). Full-length PmE2F-2 complementary DNA sequence measures 3,189 bp with an open reading frame of 1,371 bp. Complete PmE2F-2 genomic sequence (17,305 bp) of P. monodon contains nine exons, which are separated by eight introns. Quantitative real-time polymerase chain reaction (qRT-PCR) analysis indicated that PmE2F-2 is highly expressed in hepatopancreas and ovaries of P. monodon. Highest PmE2F-2 expression levels were observed in stage III ovarian development of P. monodon. PmE2F-2 expression levels were significantly augmented in ovaries of P. monodon after 5-hydroxytryptamine injection and eyestalk ablation. RNA interference experiments were conducted to examine PmE2F-2, PmCDK2, and PmCyclin E expression profiles. PmE2F-2 was successfully knocked down in ovaries and hepatopancreas via double-stranded RNA (dsRNA)-E2F-2 injection. In the same organs, PmE2F-2 expression localization and level were investigated through in situ hybridization, which revealed consistent results with those of qRT-PCR. After dsRNA-E2F-2 injection, gonadosomatic index of shrimp was significantly lower than those following dsRNA-GFP and phosphate-buffered solution injections. Therefore, PmE2F-2 may be involved in ovarian maturation in P. monodon.

The immune response of the C-Jun in the black tiger shrimp (Penaeus monodon) after bacterial infection

The transcription factor C-Jun widely exists in vertebrates and invertebrates and plays an important role in various kinds of stimulus response. In this study, PmC-jun gene was first cloned from Penaeus monodon. The full-length cDNA of PmC-jun was 1857 bp in length and included an 879 bp open reading frame (ORF), which encoded 293 amino acids. qRT-PCR analysis results showed that PmC-jun mRNAs were ubiquitously expressed in all the examined tissues. The highest expression level was observed in gill, followed by hepatopancreas. The expression patterns of PmC-jun after Vibrio harveyi and Streptococcus agalactiae injections were studied by qRT-PCR experiment. PmC-jun increased obviously in the gill and hepatopancreas. The expression pattern of PmC-jun in the hepatopancreas was further studied using in situ hybridization (ISH) method. The mRNA expression level of PmC-jun significantly increased in the hepatopancreas after bacterial infection. The expression sites of PmC-jun were almost unchanged. PmC-jun played a regulatory role in pathogen invasion.