A comprehensive evaluation of multicentric reliability of single-subject cortical morphological networks on traveling subjects.

Despite the prevalence of research on single-subject cerebral morphological networks in recent years, whether they can offer a reliable way for multicentric studies remains largely unknown. Using two multicentric datasets of traveling subjects, this work systematically examined the inter-site test-retest (TRT) reliabilities of single-subject cerebral morphological networks, and further evaluated the effects of several key factors. We found that most graph-based network measures exhibited fair to excellent reliabilities regardless of different analytical pipelines. Nevertheless, the reliabilities were affected by choices of morphological index (fractal dimension > sulcal depth > gyrification index > cortical thickness), brain parcellation (high-resolution > low-resolution), thresholding method (proportional > absolute), and network type (binarized > weighted). For the factor of similarity measure, its effects depended on the thresholding method used (absolute: Kullback-Leibler divergence > Jensen-Shannon divergence; proportional: Jensen-Shannon divergence > Kullback-Leibler divergence). Furthermore, longer data acquisition intervals and different scanner software versions significantly reduced the reliabilities. Finally, we showed that inter-site reliabilities were significantly lower than intra-site reliabilities for single-subject cerebral morphological networks. Altogether, our findings propose single-subject cerebral morphological networks as a promising approach for multicentric human connectome studies, and offer recommendations on how to determine analytical pipelines and scanning protocols for obtaining reliable results.

Computational Simulation of HIV Protease Inhibitors to the Main Protease (Mpro) of SARS-CoV-2: Implications for COVID-19 Drugs Design.

SARS-CoV-2 is highly homologous to SARS-CoV. To date, the main protease (Mpro) of SARS-CoV-2 is regarded as an important drug target for the treatment of Coronavirus Disease 2019 (COVID-19). Some experiments confirmed that several HIV protease inhibitors present the inhibitory effects on the replication of SARS-CoV-2 by inhibiting Mpro. However, the mechanism of action has still not been studied very clearly. In this work, the interaction mechanism of four HIV protease inhibitors Darunavir (DRV), Lopinavir (LPV), Nelfinavir (NFV), and Ritonavire (RTV) targeting SARS-CoV-2 Mpro was explored by applying docking, molecular dynamics (MD) simulations, and MM-GBSA methods using the broad-spectrum antiviral drug Ribavirin (RBV) as the negative and nonspecific control. Our results revealed that LPV, RTV, and NFV have higher binding affinities with Mpro, and they all interact with catalytic residues His41 and the other two key amino acids Met49 and Met165. Pharmacophore model analysis further revealed that the aromatic ring, hydrogen bond donor, and hydrophobic group are the essential infrastructure of Mpro inhibitors. Overall, this study applied computational simulation methods to study the interaction mechanism of HIV-1 protease inhibitors with SARS-CoV-2 Mpro, and the findings provide useful insights for the development of novel anti-SARS-CoV-2 agents for the treatment of COVID-19.

Interleukin-33 Predicts Poor Prognosis and Promotes Renal Cell Carcinoma Cell Growth Through its Receptor ST2 and the JNK Signaling Pathway.

BACKGROUND/AIMS: Renal cell carcinoma (RCC) is currently the ninth most common cancer in men. Interleukin (IL)-33 expression has previously been associated with a number of cancers; however, its biological role in RCC is poorly understood. In this study, we sought to elucidate the role of IL-33 in RCC. METHODS: Serum IL-33 levels were measured by ELISA. IL-33 expression in clinical RCC samples was examined by immunocytochemistry. The proliferation and apoptosis rate of RCC were determined by CCK8 and flow cytometry. Mcl1 and Bcl-2 expression were measured by quantitative real-time PCR and western blotting. JNK expression were measured by western blotting and flow cytometry. The in vivo role of IL-33 in RCC tumorigenesis was examined by animal models. RESULTS: We found that increased expression of IL-33 in RCC was associated with tumor-lymph node-metastasis (TNM) stage and inversely correlated with prognosis. IL-33 enhances RCC cell growth in vivo and stimulates RCC cell proliferation and prevents chemotherapy-induced tumor apoptosis in vitro. Furthermore, we demonstrated that IL-33 promotes RCC cell proliferation and chemotherapy resistance via its receptor ST2 and the JNK signaling activation in tumor cells. CONCLUSION: Our findings suggest that targeting IL-33/ST2 and JNK signaling may have potential value in the treatment of RCC.

Molecular characterization and expression analysis of tumor necrosis factor receptor-associated factors 3 and 6 in large yellow croaker (Larimichthys crocea).

The large yellow croaker (Larimichthys crocea) has a well-developed innate immune system. To gain a better understanding of the defense mechanisms involved in this system, we studied tumor necrosis factor receptor-associated factors (TRAFs), which play important roles in the Toll-like receptor (TLR) pathway. We characterized the full-length open reading frames and protein structures of TRAF3 and TRAF6 to determine their identities, and conducted phylogenetic analysis to determine their evolutionary relationships. To assess the roles of TRAFs in innate immune responses in the large yellow croaker, we performed quantitative reverse-transcription PCR (qRT-PCR) to characterize expression profiles in a range of tissues at different stages after challenge with polyinosinic polycytidylic acid (poly I:C) and Vibrio anguillarum. Following poly I:C challenge, the expression levels of TRAF3 and TRAF6 were highest in the kidneys and lowest in the spleen, whereas after infection with V. anguillarum, TRAF6 expression was the highest in the kidneys and lowest in the liver.

Molecular characterization and expression analysis of large yellow croaker (Larimichthys crocea) interleukin-12A, 16 and 34 after poly I:C and Vibrio anguillarum challenge.

Interleukin-12, 16 and 34 are important pro-inflammatory cytokines, some of the most important components of the innate immunity system. Herein, we identified interleukin-12A (lcIL12A), 16 (lcIL16) and 34 (lcIL34) in large yellow croaker (Larimichthys crocea), and determined their expression profile in unchallenged and challenged tissues. The coding sequence (CDS) of lcIL12A comprised 600 bp long encoding a protein of 199 amino acids (aa), the CDS of lcIL16 was 2454 bp encoding a protein of 817 aa, and the CDS of lcIL34 was 657 bp encoding a protein of 267 aa. Phylogenetic analysis revealed similar results to homology comparison that lcIL12A was closest to IL12A of Dicentrarchus labrax (73%) and Serola dumerili (73%), while lcIL16 had the closest relation to Lates calcarofer (72.6%), and lcIL34 to Sparus aurata (88.9%). Multiple sequence alignment showed these interleukins were highly conserved with other vertebrate interleukins in their functional domains. Further, quantitative real time PCR (qPCR) analysis revealed that lcIL12A, lcIL16 and lcIL34 were constitutively expressed in all examined tissues, with significantly higher expression in spleen, liver and kidney. This was especially true for lcIL34 gene. Importantly, when challenged with polyinosinic:polycytidylic acid (poly I:C) and Vibrio anguillarum (V. anguillarum), the mRNA expressions of these interleukins were up-regulated in liver, spleen and kidney. Their top values got over 4 folds at least relative to their expression at time 0, and even lcIL12 reached 13.37 fold at 12-h point in spleen. These suggested their anti-viral and anti-bacterial roles and their involvement in the innate immune response of Larimichthys crocea. These results would have major implications in improving our understanding of the functions of interleukins to defend against pathogen infections in teleost species.

Cloning and functional characterization of thioredoxin genes from large yellow croaker Larimichthys crocea.

Thioredoxin(Trx)with a redox-active disulfide/dithiol in the active site, is an ubiquitous disulfide reductase majorly responsible for maintaining the balance of reactive oxygen species. In this study, the complete thioredoxin-like protein 1 (designated as LcTrx) was cloned from large yellow croaker Larimichthys crocea through rapid amplification of cDNA ends. The full-length cDNA of LcTrx was 1295 bp in length containing a 131 bp 5' untranslated region (UTR) ,a 3'UTR of 294bp with a poly (A) tail, and an 870 bp open reading frame (ORF) encoding a polypeptide of 289 amino acids. Protein sequence analysis revealed that LcTrx contains the evolutionarily conserved redox motif CRPC (Cys-Arg-Pro-Cys-). Multiple alignments revealed that LcTrx is highly identical to Trx from other organisms, especially in the CRPC motifs. The recombinant LcTrx showed obvious insulin reduction activity in vitro. The LcTrx transcripts were constitutively expressed in all examined tissues with the highest levels found in the muscles and the lowest in the head kidney. Results of Vibrio parahaemolyticus infection experiment showed that the expression levels of LcTrx were tissue and time dependent. In the liver and kidney, LcTrx was down-regulated both at 12 h and 48 h post-infection. In contrast, LcTrx showed induced expression in the spleen and head kidney at same post-infection time points. The different responses to pathogen stimulation indicated the diversified physiological function of LcTrx in the four examined tissues.

A novel toll-like receptor from Mytilus coruscus is induced in response to stress.

Toll-like receptor (TLR) is considered to be an evolutionarily conserved transmembrane protein which promotes the Toll signal pathway to active the expression of transcription factors in the innate immunity of the organism. In this study, a full length of TLR homologue of 2525bp in Mytilus coruscus (named as McTLR-a, GenBank accession no: KY940571) was characterized. Its ORF was 1815 bp with a 5'untranslated region (UTR) of 128 bp and a 3'UTR of 582 bp, encoding 602 amino acid residues with a calculated molecular weight of 70.870 kDa (pI = 6.10). BLASTn analysis and phylogenetic relationship strongly suggested that this cDNA sequence was a member of TLR family. Quantitative real time RT-PCR showed that constitutive expression of McTLR-a was occurred, with increasing order in hemocyte, gonad, mantle, adducter, gill and hepatopancreas. Bacterial infection and heavy metals stimulation up-regulated the expression of McTLR-a mRNA in hepatopancreas with time-dependent manners. The maximum expression appeared at 12 h after pathogenic bacteria injection, with approximately 22-fold in Aeromonas hydrophila and 17-fold in Vibrio parahemolyticus higher than that of the blank group. In heavy metals stress group, they all reached peaks at 3d, while the diverse concentration caused the maximum expression were different. The highest expression reached approximately 7-fold higher than the blank in low concentration of Pb2+ exposure. In Cu2+ treated group, it reached the peak (approximately 12-fold higher than the blank)in middle concentration. These results indicated that McTLR-a might be involved in the defense response and had a significant role in mediating the environmental stress.

Transcriptome analysis demonstrates that long noncoding RNA is involved in the hypoxic response in Larimichthys crocea.

The large yellow croaker (Larimichthys crocea) has low hypoxia tolerance compared with other fish species, and the mRNA levels of hypoxia-inducible factor (HIF)-1α in its brain do not change markedly under hypoxic conditions. In this study, we investigated noncoding transcription in the hypoxic response mechanism of L. crocea. We generated a catalog of long noncoding RNAs (lncRNAs) from the brain of L. crocea individuals under hypoxic stress, investigated lncRNA expression patterns, and analyzed the HIF signaling pathway by RNA sequencing. Prolyl hydroxylase domain 2 (PHD2) expression significantly increased after 6 and 12 h of hypoxia, and a lncRNA (Linc_06633.1) was found in the upstream, antisense region of PHD2. Linc_06633.1 may be an important regulator that promotes PDH2 expression under hypoxia in L. crocea, and we constructed a regulatory profile of L. crocea under hypoxic conditions. To the best of our knowledge, it is the first study that has been conducted on hypoxia signaling pathway regulation by lncRNAs in L. crocea and elucidates the role played by lncRNAs in the regulation of the hypoxia stress response in teleost fish.

Molecular characterization and expression analysis of the large yellow croaker (Larimichthys crocea) chemokine receptors CXCR2, CXCR3, and CXCR4 after bacterial and poly I:C challenge.

The large yellow croaker (Larimichthys crocea) has a well-developed innate immune system. We studied a component of this system, chemokine receptor CXCR family. In this study, we report the full-length open reading frames, as well as the identification and characterization of the chemokine receptor genes CXCR2 (LycCXCR2), CXCR3 (LycCXCR3), and CXCR4 (LycCXCR4) of large yellow croaker. We report that LycCXCR3 and LycCXCR4 are evolving neutrally according to PAML analyses. Quantitative real-time PCR analysis revealed that CXCR transcripts were expressed in all examined tissues. The expression of chemokine receptors LycCXCR2, LycCXCR3, and LycCXCR4 was elevated in the kidney, spleen, and particularly the liver of the large yellow croaker after challenge with Vibrio anguillarum and polyinosinic:polycytidylic acid (poly I:C). These results suggest that LycCXCR2, LycCXCR3, and LycCXCR4 may be important immune-related genes, playing crucial roles in immune defence against bacterial infection.

Pre-acclimation to low copper mitigated immunotoxic effects in spleen and head-kidney of large yellow croaker (Pseudosciaena crocea) when exposed subsequently to high copper.

The hypothesis tested in this study was that Cu pre-acclimation would mitigate high Cu induced immunotoxic effects in large yellow croaker Pseudosciaena crocea. To the end, fish were pre-acclimation to 0 and 84µg CuL-1 for 48h and then exposed to 0 and 420µg CuL-1 for another 48h. Survival rate, Cu content, ROS, NO, activities and mRNA levels of inflammatory genes (iNOS and COX-2), and gene expressions of transcription factor NF-κB and its inhibitor IκBα were determined in spleen and head-kidney of large yellow croaker. Cu pre-acclimation significantly reduced mortality of fish exposed to 420µg CuL-1. Cu pre-acclimation triggered the up-regulation of both enzyme activities and express levels of iNOS and COX-2 in spleen under 420µg CuL-1 exposure, resulting in remarkable reduction of Cu content and ROS in this tissue. Contrast to spleen, iNOS activity remained unchanged but the mRNA level of iNOS increased, and the mRNA level of COX-2 remained constant though COX-2 activity enhanced in head-kidney, suggesting iNOS and COX-2 may be modulated by Cu at a post-transcriptional level. In this process, NF-κB/IκBα signaling molecules may play a vital role in the transcriptional activation of inflammatory genes in both spleen and head-kidney. In conclusion, low Cu pre-acclimation alleviated high Cu induced immunotoxicity in spleen and head-kidney of large yellow croaker by enhancing the activities and mRNA levels of inflammatory genes.

Negative effect of chronic cadmium exposure on growth, histology, ultrastructure, antioxidant and innate immune responses in the liver of zebrafish: Preventive role of blue light emitting diodes.

The present study explored the possible preventive effects of blue light emitting diodes (LEDs) on cadmium (Cd)-induced oxidative stress and immunotoxicity in zebrafish. To this end, zebrafish were exposed to a white fluorescent bulb or blue LEDs (LDB, peak at 450nm, at an irradiance of 0.9W/m2), and 0 or 30µgL-1 waterborne Cd for 5 weeks. Growth performance, survival rate, and hepatic histology, ultrastructure, antioxidant and innate immune responses were determined in zebrafish. Cd exposure alone reduced growth and survival rate, and induced oxidative damage and changes in histology and ultrastructure. However, Cd exposure in combination with LDB apparently relieved these negative effects. The alleviation of adverse effects might result from the up-regulation of antioxidant and innate immune genes at transcriptional, translational, or post-translational levels. Cd exposure alone dramatically enhanced mRNA levels of nuclear transcription factor κB (NF-κB) and E2-related factor (Nrf2). However, compared to Cd exposure alone, Cd exposure in combination with LDB apparently down-regulated both genes. Taken together, our results suggest that chronic Cd exposure induced a negative effect on zebrafish, possibly involved in NF-κB-induced immunotoxicity and Nrf2-induced oxidative stress. Finally, for the first time, our data demonstrated that LDB could protect fish against Cd toxicity.

Organ-specific effects of low-dose zinc pre-exposure on high-dose zinc induced mitochondrial dysfunction in large yellow croaker Pseudosciaena crocea.

The study was carried out to evaluate the effects of low-dose zinc (Zn) pre-exposure on survival rate, new Zn accumulation, and mitochondrial bioenergetics in the liver and spleen of large yellow croaker exposed to high-dose Zn. To the end, fish were pre-exposed to 0 and 2 mg L-1 Zn for 48 h and post-exposed to 0 and 12 mg L-1 Zn for 48 h. Twelve milligrams Zn per liter exposure alone reduced survival rate, but the effect did not appear in the 2 mg L-1 Zn pre-exposure groups. Two milligrams per liter Zn pre-exposure also ameliorated 12 mg Zn L-1 induced new Zn accumulation, reactive oxygen species (ROS) levels, and mitochondrial swelling in the liver. However, these effects did not appear in the spleen. In the liver, 2 mg L-1 Zn pre-exposure apparently relieved 12 mg L-1 Zn induced down-regulation of activities of ATP synthase (F-ATPase), succinate dehydrogenase (SDH), and malate dehydrogenase (MDH). The mRNA levels of these genes remained relatively stable in fish exposed to 12 mg L-1 Zn alone, but increased in fish exposed to 12 mg L-1 Zn with 2 mg L-1 Zn pre-treatment. In the spleen, 2 mg Zn L-1 pre-exposure did not mitigate the down-regulation of mRNA levels of genes and activities of relative enzymes induced by 12 mg L-1 Zn. In conclusion, our study demonstrated low-dose zinc pre-exposure ameliorated high-dose zinc induced mitochondrial dysfunction in the liver but not in the spleen of large yellow croaker, indicating an organ-specific effect.

Abrupt salinity stress induces oxidative stress via the Nrf2-Keap1 signaling pathway in large yellow croaker Pseudosciaena crocea.

The aim of the present study was to evaluate the effects of abrupt salinity stress (12, 26 (control), and 40) on lipid peroxidation, activities and mRNA levels of antioxidant enzymes (Cu/Zn-SOD, CAT, GPx, and GR), and gene expression of the Nrf2-Keap1 signaling molecules at different times (6, 12, 24, and 48 h) in the liver of large yellow croaker Pseudosciaena crocea. The results showed that lipid peroxidation was sharply reduced at 6 h and increased at 12 h before returning to control levels in the hypo-salinity group. Similarly, lipid peroxidation was significantly decreased at 6 h followed by a sharp increase towards the end of the exposure in the hyper-salinity group. Negative relationships between lipid peroxidation and antioxidant enzyme activities and positive relationships between activities and gene expression of antioxidant enzymes were observed, suggesting that the changes at molecular levels and enzyme activity levels may provide protective roles against damage from salinity stress. Obtained results also showed a coordinated transcriptional regulation of antioxidant genes, suggesting that Nrf2 is required for regulating these genes. Furthermore, there was a positive relationship between the mRNA levels of Nrf2 and Keap1, indicating that Keap1 plays an important role in switching off the Nrf2 response. In conclusion, this is the first study to elucidate effects of salinity stress on antioxidant responses in large yellow croaker through the Keap1-Nrf2 pathway.

Different effects of low- and high-dose waterborne zinc on Zn accumulation, ROS levels, oxidative damage and antioxidant responses in the liver of large yellow croaker Pseudosciaena crocea.

The aim of the present study was to assess survival rate, Zn accumulation, reactive oxygen species (ROS) levels, oxidative damage and antioxidant responses after Zn exposure (2 and 8 mg L-1 Zn) at different exposure times (6, 12, 24, 48 and 96 h) in the liver of large yellow croaker. Survival rate was reduced at 96 h, and hepatic Zn content increased during 24-96 by 8 mg L-1 Zn. In the 2 mg L-1 Zn group, no fish died and the increase in Zn content merely occurred at 96 h. Exposure to 8 mg L-1 Zn induced accumulation of ROS, lipid peroxidation and protein carbonylation during the late stage of exposure. In contrast, exposure to 2 mg L-1 Zn did not result in oxidative damage, which may result from the up-regulation of antioxidant defenses. Although exposure to 8 mg L-1 Zn increased activities and mRNA levels of antioxidant enzymes during the early stage of exposure, including Cu/Zn-SOD, Mn-SOD, CAT, GPx and GR, the activities of these enzymes except Cu/Zn-SOD were inhibited at 96 h. Furthermore, a sharp increase in Nrf2 expression was observed in fish exposed to 8 mg L-1 at 6 and 12 h, and 2 mg L-1 at 12 h and 24 h, suggesting that Nrf2 was required for the protracted induction of these genes. The late increase in Keap1 expression may support its role in switching off the Nrf2 response. In conclusion, the present study demonstrated different effects of low- and high-dose waterborne Zn on antioxidant responses, which could contribute to the understanding of antioxidant and toxic roles of zinc on a molecular level.

The cooperative expression of Heat Shock Protein 70 KD and 90 KD gene in juvenile Larimichthys crocea under Vibrio alginolyticus stress.

Heat shock proteins (HSPs) play significant roles in the immune response of fish in defending against diverse environmental threats or stresses. In this study, two complete HSP70 and HSP90 genes of Larimichthys crocea (designated as LycHSP70 and LycHSP90) were identified and characterized (GenBank accession no. KT456551 and KT456552). The complete open reading frame (ORF) fragments of LycHSP70 and LycHSP90 were 1917 bp and 2151 bp, encoding 638 and 716 amino acids residues respectively. Many significant functional domains and motifs were found, such as Hsp70 family signatures, Hsp90 family signatures, ATP-GTP binding site and EEVD motif regions, and they were associated with relative functions. Phylogenetic relationship and BLASTp analysis interpreted that they were unambiguously assigned to HSP70 and HSP90 family. The total length DNA of LycHSP70 was 7889bp, LycHSP90 was 5618 bp, and the gene location mapping were analyzed based on the whole-genomic DNA sequence of L. crocea. LycHSP70 and LycHSP90 were constantly expressed in eight tested tissues, with their expression peaks appearing in liver. Spleen, brain and head kidney also witnessed higher expression level. LycHSP70 and LycHSP90 were significantly induced by pathogenic bacteria V. alginolyticus, and they were both up-regulated in liver and spleen from 0 to 72 h post-injection. All the findings would contribute to better understanding the biologic function of HSPs in defending against pathogenic bacteria challenge and further exploring the innate immune response in fish.

Abundant members of Scavenger receptors family and their identification, characterization and expression against Vibrio alginolyticus infection in juvenile Larimichthys crocea.

Scavenger receptors (SRs) are crucial pattern recognition receptors (PRRs) to defense pathogen infection in fish innate immunity. In this paper, some members in SRs family of Larimichthys crocea were identified, including eight genes in the class A, B, D and F families. (G + C) % of all SRs members held 51% ∼ 59%, and these genes were no obvious codon bias by analyzing the distribution of A-, T-, G- and C-ended codons. The order of Enc for all SRs members by sequencing was LycCD68 > LycSCARA5 > LycSCARB1 > LycCD163 > LycMARCO > LycSREC1 > LycSCARA3 > LycSREC2. Moreover, different lengths and numbers of exons and introns led to the diverse mRNAs and respective functional domains or motifs, for example, an optional cysteine-rich (SRCR) domain in LycMARCO and LycSCARA5, an epidermal growth factor (EGF) and EGF-like domain in LycSREC1 and LycSREC2. The sub-cellular localization demonstrated SRs members mainly located in plasma membrane or extracellular matrix. Further, all of the SRs members in L. crocea were almost low expressed in heart, gill and intestine, whereas high in spleen and liver. After stimulation by Vibrio alginolyticus, the class A and F families were induced significantly, but the class B and D families expressed less even none after pathogenic infection. All the findings would pave the way to understand not only the evolution of the SR-mediated immune response, but also the complexity of fish immunity.

Characterisation and expression analysis of two terminal complement components: C7 and C9 from large yellow croaker, Larimichthys crocea.

The large yellow croaker Larimichthys crocea, as one of the most economically important marine fish in China and East Asian countries, are facing the fatal attraction of various pathogens in recent years. Elucidation of the organism immunomodulatory mechanism of croaker response to pathogen infection is essential for the disease control. In present study, we reported for the first time the molecular characterization and expression analysis of two terminal complement components (TCCs) of croaker, Lc-C7 and Lc-C9. These two structural conserved TCCs were detected in many tissues in adult healthy fish, with highest levels detected in liver. The transcriptional expression analysis of Lc-C7 and Lc-C9 at different developmental stages showed a continuous increase towards hatch, however the two TCCs mRNA were not detected at the unfertilized stage, hinting the origination of these two TCCs after fertilization. Rapid and drastic responses to Vibrio alginolyticus challenge were observed for Lc-C7 and Lc-C9, suggesting the involvement of component C7 and C9 in innate immune responses to pathogenic invasion in teleost fish. These findings could deepen our understanding about immunomodulatory mechanisms of croaker and shed a new light to the role of component system in teleostean immunomodulation.

Positive and negative innate immune responses in zebrafish under light emitting diodes conditions.

Certain light emitting diodes (LEDs) have become popular in fish farming beacause of a promoting effect on growth and reproduction. However, little information is available on innate immune responses in related tissues under LEDs conditions. The present study assessed the effects of a white fluorescent bulb (the control) and two different light-emitting diodes (LEDs: blue, LDB, peak at 450 nm; red, LDR, 630 nm) on growth and innate immune responses in the serum, liver and ovary of zebrafish for 8 weeks. LDB significantly enhanced specific growth rate (SGR), food intake (FI), and serum globulin levels. In contrast, LDR sharply inhibited SGR, FI, and the levels of albumin and globulin. Under LDB condition, there was an increase in protein levels of alkaline phophatase (AKP) and protein and activity levels of lysozyme (LZM) in the liver, and the levels of mRNA, protein, and activity of LZM in the ovary. Under LDR condition, LZM was dramatically down-regulated at mRNA, protein and activity levels in the ovary, suggesting that LZM was regulated at a transcriptional level. In the liver of the LDR group, though AKP mRNA levels sharply increased, its protein and activity levels significantly declined, indicating that AKP was regulated at translational level. Furthermore, a positive correlation between transcription factor NF-κB RelA mRNA levels and expression levels of AKP and LZM was observed in the liver and ovary, implying a transcriptional regulation of NF-κB RelA. In conclusion, the present study demonstrated a positive effect of LDB and negative effect of LDR on fish growth and innate immune responses, possibly associated with modifications at transcriptional, translational, and post-translational levels, and the transcriptional regulation of the NF-κB signaling molecule.

Transcriptome analysis demonstrate widespread differential expression of long noncoding RNAs involve in Larimichthys crocea immune response.

Long noncoding RNAs (lncRNAs) are a class of transcripts that longer than 200 bp and do not encode proteins. Recent genome-wide studies of vertebrate transcriptomes have annotated lncRNAs that are expressed in various tissues and development stages. The draft genome and several transcriptome sequencing data sets have been collected for the study of protein-coding genes in large yellow croaker (Larimichthys crocea), but little is known about the expression and functional roles of lncRNAs in this species. In order to obtain a catalog of lncRNAs for large yellow croaker, several RNA-seq datasets were integrated from various tissues including egg, muscle, liver, and spleen. A total of 48,953 high-confidence transcripts were reconstructed in 38,017 loci, recovering the most of expressed reference transcripts while thousands of novel expressed loci have been identified. The tissue expression profile revealed that most lncRNAs were specifically enriched in different tissues. A stringent set of 210 lncRNAs were identified as being specifically expressed in spleen and potentially involved in immune response. Our study first systematically identify lncRNAs in large yellow croaker, benefiting the future genomic study of this species.

Anti-infective mannose receptor immune mechanism in large yellow croaker (Larimichthys crocea).

Mannose receptor (MR) is a pattern recognition receptor (PRR) that plays a significant role in immunity responses. Its role has been described extensively in mammals, but very rarely in fish. Recently, with the rapid development of an aquaculture industry cultivating large yellow croaker (Larimichthys crocea), infectious diseases caused by viruses, bacteria and parasites are becoming more frequent and more severe, in particular bacterial infections caused by Vibrio anguillarum, resulting in great economical losses. Extensive use of antibiotics as conventional treatment has led to microenvironment imbalances, development of drug-resistant bacteria and deposition of drug residues, which cause environmental pollution and ultimately affect human health. The purpose of this pilot study was to detect the transcriptional levels of C-type mannose receptor genes MRC1 (4710-bp ORF; encoding 1437 aa; a signal peptide, a SMART RICIN domain, a SMART FN2 domain, eight SMART CLECT domain, and a transmembrane helix region) and MRC2 (3996-bp ORF; encoding 1484 aa; a SMART FN2 domain, eight SMART CLECT domains, and a transmembrane region) in the liver, kidney and spleen tissues of L. crocea challenged by V. anguillarum, to explore the effective domain and the molecular response mechanisms of MRC1 and MRC2, and, ultimately, to explore the possibility of developing a vaccine targeting V. anguillarum infections.