Single-Atom Cu Nanozyme-Loaded Bone Scaffolds for Ferroptosis-Synergized Mild Photothermal Therapy in Osteosarcoma Treatment.

The rapid multiplication of residual tumor cells and poor reconstruction quality of new bone are considered the major challenges in the postoperative treatment of osteosarcoma. It is a promising candidate for composite bone scaffold which combines photothermal therapy (PTT) and bone regeneration induction for the local treatment of osteosarcoma. However, it is inevitable to damage the normal tissues around the tumor due to the hyperthermia of PTT, while mild heat therapy shows a limited effect on antitumor treatment as the damage can be easily repaired by stress-induced heat shock proteins (HSP). This study reports a new type of single-atom Cu nanozyme-loaded bone scaffolds, which exhibit exceptional photothermal conversion properties as well as peroxidase and glutathione oxidase mimicking activities in vitro experiments. This leads to lipid peroxidation (LPO) and reactive oxygen species (ROS) upregulation, ultimately causing ferroptosis. The accumulation of LPO and ROS also contributes to HSP70 inactivation, maximizing PTT efficiency against tumors at an appropriate therapeutic temperature and minimizing the damage to surrounding normal tissues. Further, the bone scaffold promotes bone regeneration via a continuous release of bioactive ions (Ca2+, P5+, Si4+, and Cu2+). The results of in vivo experiments reveal that scaffolds inhibit tumor growth and promote bone repair.

Characterization and functional analysis of a novel C-type lectin in blunt snout bream (Megalobrama amblycephala).

C-type lectins, one of the pattern recognition receptors (PRRs), play significant roles in innate immune responses through binding to the pathogen-associated molecular patterns (PAMPs) presented on surfaces of microorganisms. Here, a novel C-type lectin (named as MaCTL) from blunt snout bream (Megalobrama amblycephala) was cloned and characterized. The open reading frame (ORF) of MaCTL is 573 bp long encoding a putative protein of 190 amino acids (aa), which contains a typical feature of signal peptide at 1-23 aa, a characteristic CRD domain at 45-178 aa and a WND/EPN motif that is required for carbohydrates-binding specificity. Phylogenetic analysis indicated that MaCTL is a novel member of CTL family and possessed the highest similarity to that of grass carp (92.11%). The qRT-PCR analysis revealed that MaCTL expressed widely in all examined normal tissues, including heart, liver, spleen, kidney, head-kidney, gill, intestine and muscle, with the higher expression in the spleen, liver and muscle. The expression of MaCTL in spleen was significantly elevated, peaking at 9 h and 6 h after LPS stimulation and Aeromonas hydrophila challenge, respectively, suggesting its association with involvement in innate immune response. The recombinant MaCTL protein (rMaCTL) agglutinated markedly both Gram-positive (Staphylococcus aureus) and Gram-negative bacteria, including Escherichia coli, Vibrio anguillarum, Vibrio vulnificus and Aeromonas hydrophila, in a Ca2+-dependent manner. Meanwhile, rMaCTL showed the binding effects on the five bacteria and four carbohydrates, such as glucose, surose, LPS and PGN. Moreover, rMaCTL could remarkably inhibit the growth of three types of bacteria in vitro. Overall, the results obtained above demonstrated firmly that MaCTL binds to carbohydrates on the surface of diverse pathogens as a PRR and elicits antimicrobial responses, which shed new light on a better understanding of antibacterial functions of CTLs in teleost fish.

Magnetic Field Boosts the Transmembrane Transport Efficiency of Magnesium Ions from PLLA Bone Scaffold.

In the system of magnesium-loaded scaffolds, the effect of magnesium ions (Mg2+ ) on the osteogenesis induction is restricted due to the low transmembrane transport efficiency of Mg2+ into the cell, which limits the application for bone defect repair. Inspired by the fact that magnetic field can regulate ion channel proteins on the cell membrane, magnetite nanoparticle is introduced into the poly (l-lactic acid) /magnesium oxide composite in this study, and a magnetic magnesium-loaded bone scaffold is prepared via selective laser sintering . Notably, the activities of the Mg2+ channel protein (MAGT1) on the membrane of bone marrow mesenchymal stem cells (rBMSCs) are enhanced via magnetic torque effect (via integrin αV ß3/actin), under the action of static magnetic field (SMF), which promoted rBMSCs to capture Mg2+ in the microenvironment and induced osteogenesis. In vitro experiments showed that the magnetic magnesium-loaded scaffold, under the action of SMF, can accelerate the inflow of Mg2+ from surrounding microenvironment, which improved cellular activities, osteogenesis-related gene expression (ALP, Runx2, OCN, and OPN), and mineralization. Besides, in vivo skull defect repair experiments showed that the scaffolds possessed good ability to promote bone differentiation and new bone regeneration.

Functions of circular RNAs and their potential applications in gastric cancer (Review).

As the fifth most common cancer and the fourth leading cause of cancer-related death in the world, gastric cancer (GC) poses a potential threat to human health. However, there is still a lack of effective means for the early screening and treatment of GC, and therefore, GC remains a difficult disease to overcome. With the continuous in-depth research on circular RNAs (circRNAs), an increasing body of evidence indicates that circRNAs play an important role in a wide variety of diseases, particularly cancer. Proliferation, invasion and metastatic spread of cancer cells are strongly associated with abnormal circRNA expression. Hence, circRNAs are considered a candidate biomarker for GC diagnosis and prognosis, and a target for cancer treatment. The focus has been on the association of GC with circRNAs, thus it is necessary to briefly review and summarize the relevant research to provide the research findings across the area to researchers, and to indicate the direction for future research. The present review provides an overview on the biogenesis and functions of circRNAs in GC, predicting their possible clinical application as ideal biomarkers and potential targets of treatment in GC.

Toll-interacting protein negatively regulated innate immune response via NF-κB signal pathway in blunt snout bream, Megalobrama amblycephala.

Toll-interacting protein (Tollip) is an important negative regulator of Toll-like receptor-mediated innate immunity by preventing excessive proinflammatory responses. The structure and function of Tollip have been well identified in mammals, but the piscine Tollip remains poorly understood. In the present study, a homologue of Tollip was identified and characterized from blunt snout bream (named MaTollip), which was composed of an 831 bp open reading frame encoding a protein of 276 amino acids. Phylogenetic analysis indicated that MaTollip is a novel member of Tollip family and possessed the highest similarity to that of grass carp (99.28%). Multiple alignment of amino acid sequence showed that MaTOLLIP shared a high degree of structural conservation, including a TBD domain, a C2 domain and a CUE domain, with its counterparts from other vertebrates. With regard to tissue-specific expression without immune challenge, MaTollip was constitutively expressed in a wide range of normal tissues, with the highest in the head-kidney and the lowest in the intestine. MaTollip expression in the head-kidney was strongly upregulated upon LPS stimulation and A. hydrophila infection. Fluorescence microscopic analysis revealed that the green fluorescent protein-TOLLIP was localized predominantly in the cytoplasm of EPC cells in a dot-like state. When MaTollip was overexpressed in HEK-293T and EPC cells, it could significantly inhibit the activity of nuclear factor-κB (NF-κB) promoter in a dose dependent manner. MaTollip overexpression in MAF cells lowered drastically the transcriptional expression level of lipopolysaccharide-induced proinflammatory cytokines (IL-1ß, IL-6 and IL-8), whereas they were dramatically promoted by MaTollip knock down with siRNA. Taken together, this study demonstrated that MaTollip played a pivotal role in mediating host innate immune response to pathogen invasion, and unveiled the involvement of MaTollip in NF-κB-mediated transcription of inflammation genes, which paved the way for further studies of immune negative regulation mechanisms mediated by Tollip in fish.

Identification and expression analysis of sex biased miRNAs in chinese hook snout carp Opsariichthys bidens.

As an economically important fish, Opsariichthys bidens has obvious sexual dimorphism and strong reproductive capacity, but no epigenetics study can well explain its phenotypic variations. In recent years, many microRNAs involved in the regulation of reproductive development have been explored. In this study, the small RNA libraries of O. bidens on the testis and ovary were constructed and sequenced. A total of 295 known miRNAs were obtained and 100 novel miRNAs were predicted. By comparing testis and ovary libraries, 115 differentially expressed (DE) miRNAs were selected, of which 53 were up-regulated and 62 were down-regulated. A total of 64 GO items (padj < 0.01) and 206 KEGG pathways (padj < 0.01) were enriched in the target gene of miRNA. After that, the expression levels of nine DE miRNAs, including let-7a, miR-146b, miR-18c, miR-202-5p, miR-135c, miR-9-5p, miR-34c-3p, miR-460-5p and miR-338 were verified by qRT-PCR. Furthermore, bidirectional prediction of DE miRNAs and sex-related genes was carried out and the targeting correlation between miR-9-5p and nanos1 was verified by Dual-Luciferase reporter assay. Our findings identified the differentially expressed miRNA and paved the way to new possibilities for the follow-up study on the mechanism of miRNA-mRNA interaction in the gonads of O. bidens.

A novel interleukin-1 receptor-associated kinase 4 from blunt snout bream (Megalobrama amblycephala) is involved in inflammatory response via MyD88-mediated NF-κB signal pathway.

Interleukin-1 receptor-associated kinase 4 (IRAK4) plays a crucial role in the Toll-like receptor/IL-1R signal pathway, which mediates the downstream signal transduction involved in innate and adaptive immunity. In the present study, an IRAK4 homologue (named as MaIRAK4) from blunt snout bream (Megalobrama amblycephala) was cloned and characterized. The open reading frame (ORF) of MaIRAK4 contains 1422 nucleotides, encoding a putative protein of 473 amino acids. Protein structural analysis revealed that MaIRAK4 has an N-terminal death domain (DD) and a central kinase domain (S_TKc), similar to those of mammals and other fishes. Multiple sequence alignment demonstrated that MaIRAK4 is highly homologous with that of grass carp (97.67%). The qRT-PCR analysis showed that MaIRAK4 expressed widely in all examined tissues, including heart, liver, spleen, kidney, head-kidney, gill, intestine and muscle, with the highest expression in the liver and spleen. After stimulation with LPS, MaIRAK4 expression upregulated significantly and reached a peak at 6 h and 12 h post LPS stimulation in the spleen and head-kidney, respectively. After challenge with Aeromonas hydrophila, MaIRAK4 expression peaked at 48 h and 72 h in spleen/head-kidney and liver, respectively. These results implied that MaIRAK4 is involved in the host defense against bacterial infection. Subcellular localization analysis indicated that MaIRAK4 distributed in the cytoplasm. Co-immunoprecipitation and subcellular co-localization assay revealed that MaIRAK4 can combine with MaMyD88 through DD domain. MaIRAK4 overexpression can induce slightly the NF-κB promoter activity in HEK 293 cells. However, the activity of NF-κB promoter was dramatically enhanced after co-transfection with MaIRAK4 and MaMyD88 plasmids. The results showed that MaIRAK4 was involved in NF-κB signal pathway mediated by maMyD88. The expression level of pro-inflammatory cytokines (IL-1ß, IL-6, IL-8 and TNF-α) decreased significantly after the siRNA-mediated knockdown of MaIRAK4. Together, these results suggest that MaIRAK4 plays an important function in the innate immunity of M. amblycephala by inducing cytokines expression.

TAK1 of blunt snout bream promotes NF-κB activation via interaction with TAB1 in response to pathogenic bacteria.

Transforming growth factor-ß activated kinase-1 (TAK1) is an important upstream signaling molecules involved in the NF-κB signaling pathway. TAK1 interacts with TAB1 to form the TAK1-TAB1 complex, which elicits NF-κB activation through a series of cascade reactions in mammals. However, the function of TAK1 in blunt snout bream (Megalobrama amblycephala ( maTak1) and the effects of their interaction between TAK1 and TAB1 on the NF-κB activation still remains largely unknown. In the present study, maTak1 was cloned and characterized successfully based on transcriptome data. Its open reading frame is composed of 1626 nucleotides and the predicted maTAK1 protein contains 541 amino acids, which includes an N-terminal Serine/Threonine protein kinases (S/TKc) and a C-terminal coiled-coil region. Phylogenetic analysis showed that maTAK1 were clustered with those of other teleosts. MaTak1 displayed ubiquitous transcriptional expression in all the examined tissues of healthy blunt snout bream but with varied expression levels. And maTrak1 expression was dramatically enhanced in different tissues and MAF cells after LPS stimulation and A. hydrophila challenge. The result from subcellular localization analysis indicated that both maTAK1 and maTAB1 were cytoplasmic protein. The activity of NF-κB promoter could not be induced by overexpression of maTak1 or maTab1 alone, however, it could be enhanced by co-expression of maTak1 and maTab1. Co-immunoprecipitation and subcellular co-localization assay revealed that maTAK1 can combine with maTAB1 directly. The transcriptional expression level of pro-inflammatory cytokines (IL-1ß, IL-6 and IL-8) increased distinctly after the overexpression of maTak1 and maTab1. Taken together, the data obtained in this study demonstrated that the direct interaction between maTAK1 and maTAB1 might play a pivotal role in mediating host innate immune response to pathogen invasion by the production of pro-inflammatory cytokines via NF-κB signaling pathway, which might lay a solid foundation for the establishment of novel therapeutic approach to combat bacterial infection in fish.

Low expression of miR-19a-5p is associated with high mRNA expression of diacylglycerol O-acyltransferase 2 (DGAT2) in hybrid tilapia.

DGAT2 (acyl CoA:diacylglycerol acyltransferase 2) is a key and rate-limiting enzyme that catalyzes the final step of triglyceride (TG) synthesis. In this study, hybrid tilapia were generated from Nile tilapia (♀) and blue tilapia (♂) crossing. The TG content levels in the liver of these tilapia were measured. The results showed that the TG content was higher in the hybrid tilapia. In addition, protein and mRNA expression levels in the tilapia livers were determined. Higher hepatic mRNA and protein expression of DGAT2 in the hybrid fish was found. A luciferase reporter assay with HEK293T cells revealed that miRNA-19a-5p targeted the 3'UTR of DGAT2, suggesting a direct regulatory mechanism. Using qRT-PCR, we found that DGAT2 mRNA levels had a negative correlation with miRNA-19a-5p expression in Nile tilapia and hybrid. Taken together, these findings provide evidence that miRNA-19a-5p is involved in TG synthesis in the regulation of lipid metabolism in tilapia.

Cadmium removal by MgCl2 modified biochar derived from crayfish shell waste: Batch adsorption, response surface analysis and fixed bed filtration.

Cadmium (Cd) pollution is regarded as a disturbing environmental problem due to its serious risks to the water body and human health. The removal of cadmium from wastewater is thus crucial to avoid its harmful effects on the ecosystem. This study comprehensively investigated Cd(II) adsorption onto MgCl2 modified biochar (MgC600) and results showed that the adsorption capacity of MgC600 was more than twice of that of pristine biochar due to its enhanced ion exchange ability. Response surface analysis revealed that reaction time played a crucial role in the Cd(II) adsorption, followed by initial concentration and solution pH. Moreover, the optimal adsorption conditions and capacity were precisely given by the quadratic regression model and thus proved that the model can be applied to predict the operation conditions of Cd(II) adsorption. Finally, a new model defined as BJP model [Formula: see text] was proposed and proved to be more suitable for the fixed bed filtration process. Overall, our findings provide a promising material in treatment of Cd(II)-rich wastewater and give a clear picture of its application. More importantly, the newly developed BJP model can accurately describe the fixed bed filtration process and further promote its application in wastewater treatment.

Effect of Different Forms of Selenium on the Physiological Response and the Cadmium Uptake by Rice under Cadmium Stress.

Cadmium (Cd) is a pollutant toxic to plants and a potential threat to human health. Selenium (Se), though not essential for plants, has beneficial effects on plants under abiotic stress. A hydroponic experiment was conducted to investigate the impact of different forms of Se (Nano-Se, selenite, selenate, and SeMet) on accumulation, subcellular distribution, and chemical forms of Cd, as well as oxidative stress in rice seedlings. Cd (20 µmol·L-1) treatment significantly decreased biomass accumulation and chlorophyll content. The application of all Se forms, except selenate, mitigated the adverse effects of Cd on growth and chlorophyll content. The application of selenite, Nano-Se, and SeMet decreased root and shoot Cd concentrations as well as root-to-shoot Cd translocation in rice seedlings. Selenate application decreased shoot Cd concentration and root-to-shoot Cd translocation with no effect on root Cd concentration. Accordingly, Se increased the sequestration of Cd in the cell wall and vacuoles and decreased the active chemical form of Cd in rice seedlings. SeMet was the most effective supplement that decreased Cd concentration and enhanced Se concentration in the roots and shoots of rice seedlings. All forms of Se further enhanced catalase (CAT) and glutathione peroxidase (GSH-Px) activities and inhibited MDA accumulation. To conclude, Se influenced Cd accumulation and translocation in rice seedlings by altering the subcellular distribution, chemical forms, and antioxidant defense system under Cd stress. These effects were highly significant with SeMet treatment, probably due to better absorption and utilization by the plant.

TRAF3 of blunt snout bream participates in host innate immune response to pathogenic bacteria via NF-κB signaling pathway.

Tumor necrosis factor receptor-associated factor 3 (TRAF3) is a multifunctional adaptor protein primarily involved in both bacterial defense and antiviral immunity in living organisms. However, the knowledge on TRAF3 in blunt snout bream (Megalobrama amblycephala), a freshwater fish with economic values, remained unclear. In the present study, we identified and characterized successfully Traf3 gene from M. amblycephala (maTraf3). The maTraf3 cDNA contained a 1722 bp open reading frame that encoded a protein of 573 amino acid residues. The deduced amino acid sequence comprised of a RING finger domain, two zinc finger motifs, a coiled-coil region and a MATH domain. Analysis of the transcriptional patterns of maTraf3 revealed that it was ubiquitously distributed in various tissues tested from M. amblycephala, with the abundance of expression in spleen and muscle. Following a challenge with Aeromonas hydrophila and lipopolysaccharide stimulation, the expression of maTraf3 was strongly enhanced at different time points in vitro and in vivo. MaTRAF3 was identified as a cytosolic protein and suggested to form aggregates or be associated with vesicles scattering in the cytoplasm. NF-κB transcription was activated by maTraf3 in reporter assay. The overexpression of maTraf3 produced high levels of pro-inflammatory cytokines such as IL-1ß, IL-6, IL-8 and TNF-α, implying its immune-regulatory role in M. amblycephala. Taken together, our results obtained in this study demonstrated the crucial role of maTraf3 in mediating host innate immune response to pathogen invasion via NF-κB signaling pathway, which might indicate a novel therapeutic approach to combat bacterial infection in fish.

Crayfish shell biochar modified with magnesium chloride and its effect on lead removal in aqueous solution.

In this study, crayfish shell was pyrolyzed at 600 °C to obtain an unmodified biochar (CS600). MgCl2 was used as a modifier to pretreat crayfish shell to produce a modified biochar (CS600-MgCl2) under the same pyrolysis conditions. The two biochars were characterized for physicochemical properties and evaluated for lead (Pb2+) sorption ability to determine the modification mechanism. Mono-element batch adsorption experiments were conducted to compare the sorption performances of CS600 and CS600-MgCl2 to Pb2+ in aqueous solutions. All the experiments were carried out at pH of 7. According to the Freundlich-Langmuir model, CS600-MgCl2 had a higher adsorption capacity (152.3 mg/g) than CS600 (134.3 mg/g). FTIR, SEM, XRD, BET, and ICP analyses were applied to inform the interpretation of the mechanism. CS600 was calcium-rich and mainly removed Pb2+ through the ion exchange mechanism by replacing Ca2+ in the biochar. The increased Pb2+ adsorption capacity of CS600-MgCl2 was mainly due to the enlarged specific surface area and the formation of Mg3(OH)5Cl·4H2O on the modified biochar. Findings of this study suggest that both CS600 and CS600-MgCl2 can be used to remove heavy metal ions from wastewater and MgCl2 can improve the sorption performance of biochar.

Ghrelin modulates the immune response and increases resistance to Aeromonas hydrophila infection in hybrid tilapia.

Ghrelin is a peptide hormone secreted by gastrointestinal tract which regulates multiple physiological processes such as appetite, metabolism, growth and gonad development in fish. In the present study, the effects of ghrelin on hybrid tilapia infected with Aeromonas hydrophila are elucidated. Juvenile hybrid tilapia fish (20.0 ± 5.0 g) were intraperitoneally injected with 0, 0.1, 1.0, or 10.0 ng/g ghrelin/body weight synthetic ghrelin alone or in combination with A. hydrophila (0.5 × 106 CFU). At 10 days post treatment, the survival rate in the group that received 1.0 ng/g ghrelin/body weight ghrelin in combination with A. hydrophila was higher (66.66%) than that of the Ah group (13.33%) that received A. hydrophila alone. In tilapia that received ghrelin injections, reactive oxygen species (ROS) levels tended to increase at 5 h, while injection of 10.0 ng/g ghrelin/body weight ghrelin resulted in a significant decrease in ROS levels at 10 h. No changes in serum immune or antioxidant-related indicators were observed in fish injected with A. hydrophila compared to controls. However, ghrelin injection decreased Albumin (ALB), glutathione peroxidase (GSH-Px), lysozyme (LZM) and superoxide dismutase (SOD). Histological analysis showed that ghrelin injection alleviated the pathological changes in liver and spleen caused by A. hydrophila infection. Overall, the expression of HSP70, IL-1ß, and TGF-ß in the liver tended to upregulate compared to the control. In the kidney, HSP70, IL-1ß and TGF-ß levels were increased, and TNF-α expression levels were decreased compared to the control. The HSP70 level in the spleen was decreased, and IL-1ß, TGF-ß, and TNF-α were expressed at significantly higher levels in the spleen in the tilapia that received ghrelin injections. Taken together, our results indicate that injection with 1.0 ng/g ghrelin/body weight ghrelin may effectively protect juvenile hybrid tilapia against A. hydrophila infection by improving hematological indicators, maintaining normal histology and regulating cytokine gene expression.

Enhanced alginate-based microsphere with the pore-forming agent for efficient removal of Cu(â ¡).

In order to increase the adsorption properties of sodium alginate gel beads, a series of SA@PF-beads (sodium alginate-based beads with different amount of pore-forming agent) were prepared with calcium carbonate as the pore forming agent. The experimental results showed that the adsorption capacity of Cu(Ⅱ) increased by at least two times (from 13.69 mg/g to 33.88 mg/g, treated with SA@PF-0 and SA@PF-2.0, respectively) with proper amount of calcium carbonate added, which is economical and effective. In the experiment, SEM was used to measure the morphology of gel beads with different amount of pore-forming agent. FTIR and XPS were used to analyze the variation of functional groups and bond energies in the adsorption process. Adsorption isotherms and kinetics were conducted and showed that the adsorption process was consistent with Langmuir model and Elovich kinetic model. The maximum Langmuir adsorption 229.746 mg/g. The effects of pH, temperature and solid-liquid ratio on adsorption capacity were also investigated. In brief, calcium carbonate is an efficient and convenient pore-forming agent, which can be used to improve the adsorption properties of alginate gel materials.

Nonadditive and Asymmetric Allelic Expression of Growth Hormone in Hybrid Tilapia.

Hybridization is a common breeding technique that can improve germplasm through heterosis in aquaculture. However, the regulation of key gene expression, including the details of transcriptional level changes at the beginning of hybridization events, remains largely undefined, especially in teleosts. In this study, by interspecies crossing between two pure lines of Nile tilapia and blue tilapia, we obtained a hybrid tilapia population as a model to elucidate heterosis, and we traced the molecular outcomes of growth hormone (GH) expression and allele-specific expression (ASE) in hybrids. The hybrids display growth vigor compared to their parents in the 120-day growth trial. GH mRNA expression was uniquely expressed in the pituitary. Higher GH expression was found in the hybrid than the midparent value, in both males and females, showing a nonadditive pattern. We identified four single-nucleotide polymorphism sites between Nile tilapia and blue tilapia. Subsequently, by pyrosequencing, we found asymmetric allelic expression in hybrids with higher maternal allelic transcript ratios in both males and females. Fasting significantly increased GH expression in hybrids, but asymmetric allelic expression was not affected by feeding or fasting conditions. Finally, we identified cis and trans effects via overall expression and ASE values in the hybrid, which showed that the cis and trans effects promoted the expression of maternal subgenome in the hybrid, contributing to the expression superiority of GH in hybrid tilapia. Taken together, the results of our study first illustrated the concept of GH expression superiority and its formation mechanism in hybrid fish with growth vigor.

Novel chitosan-ethylene glycol hydrogel for the removal of aqueous perfluorooctanoic acid.

It is urgent to explore an effective removal method for perfluorooctanoic acid (PFOA) due to its recalcitrant nature. In this study, a novel chitosan-based hydrogel (CEGH) was prepared with a simple method using chitosan and ethylene glycol through a repeated freezing-thawing procedure. The adsorption of PFOA anions to CEGH agreed well to the Freundlich-Langmuir model with a maximum adsorption capacity as high as 1275.9 mg/g, which is higher than reported values of most adsorbents for PFOA. The adsorption was influenced by experimental conditions. Experimental results showed that the main removal mechanism was the ionic hydrogen bond interaction between carbonyl groups (COO-) of PFOA and protonated amine (NH+) of the CEGH adsorbent. Therefore, CEGH is a very attractive adsorbent that can be used to remove PFOA from water in the future.

Nonadditive and allele-specific expression of insulin-like growth factor 1 in Nile tilapia (Oreochromis niloticus, ♀) × blue tilapia (O. aureus, ♂) hybrids.

Hybrid Nile tilapia (Oreochromis niloticus, ♀) × blue tilapia (O. aureus, ♂) is a widely cultured tilapia variety due to its growth vigor compared to the parent species. As a peptide hormone, insulin-like growth factor 1 (IGF-1) plays a critical role in regulating somatic growth. The present study focuses on the expression characteristics of IGF-1 in hybrid tilapia. The cloned complete open reading frame of IGF-1 in hybrid tilapia is 549 bp in length, encoding a protein of 182 amino acids. The deduced protein is highly similar to that of Nile tilapia and blue tilapia. IGF-1 was found to be primarily expressed in the liver and muscle in the hybrid; lower expression levels were found in other tissues such as the intestine, spleen, and head-kidney. Increased mRNA expression was observed in the liver and muscle of the hybrid compared to Nile tilapia and blue tilapia, indicating a nonadditive expression pattern in the hybrid. An IGF-1 SNP site (397 site: C in Nile tilapia, G in blue tilapia) for differentiating the Nile tilapia or blue tilapia subgenome in hybrids was identified. Pyrosequencing analysis of the liver transcriptome indicated that most of the hybrids (9 of 10 individuals) predominantly expressed the G allele, demonstrating bias of the blue tilapia subgenome. The present study provides novel data indicating, for the first time, overall gene expression of IGF-1 and allele-specific expression in hybrid tilapia.

Two novel MKKs (MKK4 and MKK7) from Ctenopharyngodon idella are involved in the intestinal immune response to bacterial muramyl dipeptide challenge.

Mitogen-activated protein kinase kinases (MKKs) are a class of evolutionarily conserved signalling intermediates of the MAPK signalling pathway that can be activated by a diverse range of pathogenic stimuli and are crucial for the regulation of host immune defence. In this study, two fish MKK genes (CiMKK4 and CiMKK7) were first identified and characterized from grass carp (Ctenopharyngodon idella). Similar to other reported MKKs, the present CiMKK4 and CiMKK7 contained a conserved serine/threonine protein kinase (S_TKc) domain and a canonical dual phosphorylation motif. Quantitative real-time PCR results showed that CiMKK4 and CiMKK7 were broadly transcribed in all selected tissues and developmental stages of grass carp. The mRNA expression levels of CiMKK4 and CiMKK7 in the intestine were significantly induced by bacterial muramyl dipeptide (MDP) challenge in a time-dependent manner (P < 0.01). Additionally, the stimulatory effects of bacterial MDP on CiMKK4 and CiMKK7 expression in the intestine were inhibited by the bioactive dipeptide ß-alanyl-l-histidine (carnosine) and alanyl-glutamine (Ala-Gln) (P < 0.05). Moreover, overexpression analysis revealed that CiMKK4 and CiMKK7 were localized throughout the entire cell and could significantly enhance AP-1 reporter gene activation in HEK293T cells. Taken together, these results provide the first experimental demonstration that CiMKK4 and CiMKK7 are involved in the intestinal immune response to MDP challenge in C. idella, which may provide new insight into the bacterial-induced intestinal inflammation of bony fishes.

Nonadditive expression of lipid metabolism pathway-related genes in intestine of hybrids of Nile tilapia females (Oreochromis niloticus) and blue tilapia males (Oreochromis aureus).

Nonadditive expression contributes to heterosis in hybrids. In this study, the expression profiles of twelve lipid metabolism pathway-related genes were investigated in the intestine of Nile tilapia (Oreochromis niloticus) ♀ × blue tilapia (Oreochromis aureus) ♂ hybrid. The expression of genes from the hybrid were assigned to nonadditive and additive expression pattern groups and compared with expression patterns from Nile tilapia and blue tilapia. In the intestine of the hybrid, apoA4B was expressed at intermediate levels, but apoB and MTP were assigned to ELD-B and ELD-N categories, respectively. The LPL and LRP1 showed transgressive up-regulation in the hybrid, but LDLR was assigned to the ELD-B category. For fatty acid uptake related genes, only FABP11a was categorized as nonadditive expression with transgressive up-regulation, while CD36 and FABP3 were categorized as additive expression in the intestine of the hybrid. Two genes in triacylglycerol metabolism, namely, FAS and DGAT2, showed transgressive up-regulation in the hybrid. Most of the genes analyzed in the present study showed nonadditive expression (8 in 12), and five genes showed transgressive up-regulation. These results indicated that the stimulation of lipid metabolism in the hybrid compared to that of its parents. The hyperactive expression of these genes in the hybrid may be associated with the growth and lipid usage vigor.