Time Is Ripe for Targeting Per- and Polyfluoroalkyl Substances-Induced Hormesis: Global Aquatic Hotspots and Implications for Ecological Risk Assessment.

Globally implemented ecological risk assessment (ERA) guidelines marginalize hormesis, a biphasic dose-response relationship characterized by low-dose stimulation and high-dose inhibition. The present study illuminated the promise of hormesis as a scientific dose-response model for ERA of per- and polyfluoroalkyl substances (PFAS) represented by perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS). A total of 266 hormetic dose-response relationships were recompiled from 1237 observations, covering 30 species from nine representative taxonomic groups. The standardized hormetic amplitudes followed the log-normal probability distribution, being subject to the limits of biological plasticity but independent of stress inducers. The SHapley Additive exPlanations algorithm revealed that the target endpoint was the most important variable explaining the hormetic amplitudes. Subsequently, quantitative frameworks were established to incorporate hormesis into the predicted no-effect concentration levels, with a lower induction dose and a zero-equivalent point but a broader hormetic zone for PFOS. Realistically, 10,117 observed concentrations of PFOA and PFOS were gathered worldwide, 4% of which fell within hormetic zones, highlighting the environmental relevance of hormesis. Additionally, the hormesis induction potential was identified in other legacy and emerging PFAS as well as their alternatives and mixtures. Collectively, it is time to incorporate the hormesis concept into PFAS studies to facilitate more realistic risk characterizations.

Development and validation of a urinary microRNA biomarker panel as a tool for early detection of prostate cancer in a Chinese population.

INTRODUCTION: Urinary microRNAs (miRNAs) may serve as promising biomarkers for non-invasive early detection of prostate cancer (PCa). We aimed to identify multi-miRNA urinary biomarker panel for early detection of PCa. METHODS: Urine samples from 83 PCa patients and 88 healthy control subjects in a Chinese population were collected for miRNA profiling. The absolute expression of 360 unique miRNAs were measured in each sample using a highly sensitive and robust RT-qPCR workflow. Candidate urinary miRNA biomarkers were identified based on differential expression between PCa patients and healthy controls. Multi-miRNA biomarker panels were optimised for detection of PCa using three regression algorithms (Lasso, Stepwise, Exhaustive) to identify an optimal biomarker panel with best detection performance and least number of miRNAs. RESULTS: A total of 312 miRNAs were detected in urine samples, 10 candidate urinary miRNA biomarkers differentially expressed between PCa and healthy samples were identified. A panel comprising these 10 miRNAs detected PCa with an area under the curve (AUC) of 0.738. Optimization of multi-miRNA panels resulted in a 6-miRNA biomarker panel (hsa-miR-375, hsa-miR-520d-5p, hsa-miR-199b-5p, hsa-miR-518e-5p, hsa-miR-31-3p and hsa-miR-4306) that had an AUC of 0.750. CONCLUSION: We identified a urinary miRNA biomarker panel for early detection of PCa in a Chinese population.

Responses of microRNA in digestive glands of mussel Mytilus galloprovincialis exposed to polystyrene nanoplastics.

Polystyrene nanoplastics (PS-NPs) are typical accumulated nanoplastics in the marine environment and organisms, and have strong potential risks to marine ecological environment and human health. MiRNAs could respond to and participate in the response process of environmental stressors. However, the response of miRNAs to nanoplastics has not been fully explored. In this study, miRNA responses of digestive glands in mussels Mytilus galloprovincialis treated by 200 nm PS-NPs (20, 200, 2000 µg/L) for 7 days were characterized by BGISEQ-500 deep sequencing and bioinformatics analysis, along with histopathological quantification with planimetric parameters on hematoxylin and eosin (H&E) staining. Results showed that one novel miRNA (novel_mir63) and seven known miRNAs (miR-34_2, miR-34_5, miR-281_8, let-7-5p_6, miR-10, miR-124, miR-29b-3p) were significantly (adjusted P-value < 0.05) differentially expressed after PS-NPs treatments, and most of them were down-regulated expect for novel_mir63 and miR-34_2. Function analysis of target genes corresponding to these differentially expressed miRNAs indicated that PS-NPs disturbed the process related to metabolism, aging, cardiac function, neural excitation, and repairment. Among them, acetyl-CoA C-acetyltransferase and purine metabolism pathway played vital connection roles. Meanwhile, significantly morphology changes of digestive tubes obtained from H&E stained sections also implied severely disrupted metabolic capability in digestive glands, reflected by significantly increased mean diverticular radius (MDR) and mean luminal radius (MLR) values and the ratio of MLR to mean epithelial thickness (MET), and significantly decreased MET value and MET/MDR. Overall, these findings have revealed new characterization of miRNAs and their target genes in mussel M. galloprovincialis under PS-NPs stress, and provide important clues to further elucidate the toxicity mechanisms of PS-NPs.

Throughput Maximization Using Deep Complex Networks for Industrial Internet of Things.

The high-density Industrial Internet of Things needs to meet the requirements of high-density device access and massive data transmission, which requires the support of multiple-input multiple-output (MIMO) antenna cognitive systems to keep high throughput. In such a system, spectral efficiency (SE) optimization based on dynamic power allocation is an effective way to enhance the network throughput as the channel quality variations significantly affect the spectral efficiency performance. Deep learning methods have illustrated the ability to efficiently solve the non-convexity of resource allocation problems induced by the channel multi-path and inter-user interference effects. However, current real-valued deep-learning-based power allocation methods have failed to utilize the representational capacity of complex-valued data as they regard the complex-valued channel data as two parts: real and imaginary data. In this paper, we propose a complex-valued power allocation network (AttCVNN) with cross-channel and in-channel attention mechanisms to improve the model performance where the former considers the relationship between cognitive users and the primary user, i.e., inter-network users, while the latter focuses on the relationship among cognitive users, i.e., intra-network users. Comparison experiments indicate that the proposed AttCVNN notably outperforms both the equal power allocation method (EPM) and the real-valued and the complex-valued fully connected network (FNN, CVFNN) and shows a better convergence rate in the training phase than the real-valued convolutional neural network (AttCNN).

Coupling strength of human-natural systems mediates the response of ecosystem services to land use change.

Addressing the dynamics of human-natural systems (HNS) driven by land use change (LC) is a key challenge for the sustainable development of ecosystem services (ES). However, how changes to the HNS coupling relationships affect ES is rarely reported. We used network analysis methods to construct an HNS correlation network in the Loess Plateau based on the correlation between the main components of HNS, such as ES, human factors, landscape pattern, vegetation cover, climate change and geomorphic characteristics, and quantitatively described the HNS coupling relationships through key network attributes. We analyzed the variation in HNS network attributes and their relationships with ES along an LC intensity gradient. The results show that carbon storage and soil conservation in the Loess Plateau increased by 0.56% and 0.26%, respectively, during the study period, while the habitat quality and water yield decreased by 0.11% and 0.18%, respectively. An increase in LC intensity reduces connectivity and density in the HNS network, which results in looser connections among HNS components. Importantly, we found that HNS network attributes explained 85% of ES variation across different LC intensity gradients and that connectivity and density had the strongest explanatory power. This means that LC mainly affects ES dynamics by changing the coupling strength of HNS. Our research offers a new perspective for linking LC-HNS-ES, which will help guide practitioners toward establishing and maintaining the sustainability of human well-being amidst changing HNS.

Analysis of Voiding Impairment after Prostate Biopsy and the Effect of Doxazosin Treatment: Outcomes from a Regional Cancer Center.

INTRODUCTION: The aim of this study was to investigate the association of transrectal ultrasound (TRUS)-guided prostate biopsy with voiding impairment and the efficacy of doxazosin treatment. METHODS: A prospective observational study including 200 male patients undergoing TRUS-guided prostate biopsy was performed between May 2020 and December 2020. One hundred patients underwent biopsy with doxazosin (doxazosin group). The remaining 100 patients underwent biopsy without doxazosin (control group). All patients were questioned regarding post-biopsy voiding difficulty and acute urinary retention. The International Prostate Symptom Score (IPSS), maximal urinary flow rate (Qmax), and residual urine volume were recorded before biopsy and at 7 and 30 days after biopsy. RESULTS: There were no significant differences in baseline parameters between the two groups. The rate of post-biopsy voiding difficulty in the doxazosin group was significantly lower than that in the control group. Compared with baseline values, doxazosin treatment significantly improved IPSS, quality of life scores, and Qmax after biopsy (p < 0.05). The baseline values of IPSS and prostate size may be risk factors for post-biopsy voiding difficulty. CONCLUSION: TRUS-guided prostate biopsy causes transient voiding impairments, which may be improved by doxazosin treatment.

Toxicological responses of juvenile Chinese shrimp Fenneropenaeus chinensis and swimming crab Portunus trituberculatus exposed to cadmium.

Cadmium (Cd) is one of the typical metal pollutants in the Bohai Sea. To evaluate the acute toxicological effects of Cd on marine crustaceans, juvenile Fenneropenaeus chinensis and Portunus trituberculatus were exposed to Cd at environmentally relevant concentrations (5 and 50 µg/L) for 96 h. Cd accumulation, antioxidants and metabolite profiles were characterized to elucidate the responses of juvenile crustaceans to Cd stress. Significant Cd accumulation was observed in both juvenile crustaceans in 50 µg/L Cd-treated group. Results showed that Cd exposure induced hormesis based on the alterations of GSH, SOD and CAT activities (i.e. increased levels in the low concentration of Cd treatment and recovered levels in the high concentration of Cd treatment) in juvenile P. trituberculatus. Similarly, the responses of GSH contents presented hormesis pattern in Cd-treated juvenile F. chinensis. Na+-K+-ATPase contents were significantly elevated in 50 µg/L Cd-treated group. In addition, untargeted NMR-based metabolomics indicated Cd caused the disturbance in osmotic regulation and energy consumption in both juvenile F. chinensis and P. trituberculatus via different pathways. The immunotoxicity and movement disorder were uniquely demonstrated in juvenile P. trituberculatus after Cd exposure.

Stress responses in expressions of microRNAs in mussel Mytilus galloprovincialis exposed to cadmium.

MicroRNAs (miRNAs) are known to have complicated functions in aquatic species, but little is known about the role of miRNAs in mollusk species under environmental stress. In this study, we performed small RNA sequencing to characterize the differentially expressed miRNAs in different tissues (whole tissues, digestive glands, gills, and gonads) of blue mussels (Mytilus galloprovincialis) exposed to cadmium (Cd). In summary, 107 known miRNAs and 32 novel miRNAs were significantly (p < 0.01) differentially expressed after Cd exposure. The peak size of miRNAs was 22 nucleotides. Target genes of these differentially expressions of miRNAs related to immune defense, apoptosis, lipid and xenobiotic metabolism showed significant changes under Cd stress. These findings provide the first characterization of miRNAs in mussel M. galloprovincialis and expressions of many target genes in response to Cd stress.

Graphene-triphenyl phosphate (TPP) co-exposure in the marine environment: Interference with metabolism and immune regulation in mussel Mytilus galloprovincialis.

Both immune regulation and endocrine systems are great challenges to marine organisms, and effective protocols for determining these adverse outcome pathways are limited, especially in vivo. The increasing usage of graphene nanomaterials can lead to the frequent exposure to marine organisms. Triphenyl phosphate (TPP), an organophosphate flame retardant, is frequently detected in natural environments. In this study, the combined toxic effects of co-exposure to graphene and TPP was investigated in Mytilus galloprovincialis using computational toxicology and multi-omics technology. Noticeably, graphene could disturb the membrane stability and increase the tissue accumulation of TPP. The adsorption behavior of TPP on graphene could inhibit the surface activity of graphene. In the digestive gland, transcriptomics analysis revealed the down-regulated genes in graphene + TPP treatment, including glyceraldehyde-3-phosphate dehydrogenase (GAPDH), sorbitol dehydrogenase (SORD), glutathione s-transferase mu 3 (GSTM3) and 4-aminobutyrate aminotransferase (ABAT), were mainly associated with oxidative stress and energy metabolism. Moreover, metabolic responses indicated that graphene + TPP could cause disturbances in energy metabolism and osmotic regulation marked by differentially altered ATP, glucose and taurine in mussels. These data underline the need for further knowledge on the potential interactions of nanomaterials with existing contaminants in marine organisms.

Ammonia nitrogen exposure caused structural damages to gill mitochondria of clam Ruditapes philippinarum.

Ammonia nitrogen has been one of the key pollution indicators along the Chinese coastline for quite a few years. Our previous studies have proved that ammonia nitrogen is harmful for Ruditapes philippinarum clam in several aspects. Environmental concentrations of ammonia nitrogen were found to significantly decrease ATP contents and disturb ATP metabolism, in addition to reducing the potential across the mitochondrial membrane in clam gill tissues. Accordingly, mitochondrion is considered as one of the target organelles of ammonia nitrogen toxicity in clams. However, there is a lack of direct evidence to prove it. In order to reveal detail information of ammonia nitrogen toxicity on clam mitochondria and screen the related biomarker to indicate ammonia nitrogen pollution, mitochondrial parameters in gill tissues including swelling, mtDNA copy number and marker enzyme (succinic dehydrogenase, SDH) activity were measured after the clams were exposed to 0.1 mg/L and 0.5 mg/L ammonia nitrogen for 3 days and 21 days, respectively. Moreover, adverse effects of ammonia nitrogen exposure on clam mitochondrial ultra-structures, mitochondrial swelling and division were also discriminated under transmission electron microscope (TEM). Final results showed that ammonia nitrogen exposure to both concentrations significantly induced mitochondrial swelling, reduced the number of mitochondria and messed their normal structure, decreased the number of mtDNA copies and down-regulated SDH activity, all in a concentration and duration dependent manner. So, the present study helps us to better understand the structural damage of ammonia nitrogen on mitochondria in clam gill cells and provides fundamental data for ammonia nitrogen control in aquaculture.

New insights into the mechanism of hepatocyte apoptosis induced by typical organophosphate ester: An integrated in vitro and in silico approach.

Apoptosis is one of the typical features of liver diseases, therefore molecular targets of hepatic apoptosis and regulatory mechanisms need to be further investigated. The caspases play important functions in the execution of apoptosis and many studies have focused on classical caspase-dependent cell death pathways. However, other types of cell death pathways (such as mitochondrial poly (ADP-ribose) polymerase-1 (PARP1) pathway) are suggested to be also as important as the caspase-mediated pathways in reflection of early toxic effects in hepatocytes, which requires additional research. In this work, an approach integrated in silico and in vitro was used to investigate the underlying toxicological mechanisms of hepatocyte apoptosis through the PARP1 dependent cell death pathway induced by triphenyl phosphate (TPP). Docking view showed that TPP could interact with helix αJ to affect the activation of PARP1 as a molecular initial event. In vitro assays suggested some biochemical events downstream of PARP1 activation, such as mitochondrial injury, apoptosis inducing factor (AIF) release, reactive oxygen species (ROS) production, and DNA damage. Moreover, the apoptosis was alleviated when cells were pretreated with PJ34 hydrochloride (PARP1 inhibitor), suggesting the mitochondrial PARP1 dependent pathway played a pivotal role in L02 cells apoptosis. This study indicated that PARP1 was an important molecular target in this process. And it also helped to understand the mechanism of hepatocytes apoptosis, early hepatic toxicity, and even liver diseases.

Design and Measurement of a Dual FBG High-Precision Shape Sensor for Wing Shape Reconstruction.

FBG shape sensors based on soft substrates are currently one of the research focuses of wing shape reconstruction, where soft substrates and torque are two important factors affecting the performance of shape sensors, but the related analysis is not common. A high-precision soft substrates shape sensor based on dual FBGs is designed. First, the FBG soft substrate shape sensor model is established to optimize the sensor size parameters and get the optimal solution. The two FBG cross-laying method is adopted to effectively reduce the influence of torque, the crossover angle between the FBGs is 2α, and α = 30° is selected as the most sensitive angle to the torquer response. Second, the calibration test platform of this shape sensor is built to obtain the linear relationship among the FBG wavelength drift and curvature, rotation radian loaded vertical force and torque. Finally, by using the test specimen shape reconstruction test, it is verified that this shape sensor can improve the shape reconstruction accuracy, and that its reconstruction error is 6.13%, which greatly improves the fit of shape reconstruction. The research results show that the dual FBG high-precision shape sensor successfully achieves high accuracy and reliability in shape reconstruction.

Long noncoding RNA HOXA-AS2 mediates microRNA-106b-5p to repress sepsis-engendered acute kidney injury.

HOXA cluster antisense RNA 2 (HOXA-AS2) is a long noncoding RNA associated with the development of numerous cancers. But, whether HOXA-AS2 exhibits a certain function in sepsis-engendered acute kidney injury (AKI) remains uninvestigated. We strived to unveil the role of HOXA-AS2 in sepsis-engendered AKI. The expression of HOXA-AS2 in sepsis patients, animal models and lipopolysaccharide (LPS)-impaired HK-2 cells was primarily assessed via a real-time quantitative polymerase chain reaction. The effects of HOXA-AS2 on cell survival of HK-2 cells under LPS irritation were evaluated after overexpression of HOXA-AS2. The correlation between HOXA-AS2 and microRNA (miR)-106b-5p was forecasted via bioinformatics software and verified by using a luciferase report system. Subsequently, the functions of miR-106b-5p in LPS-damaged HK-2 cells were reassessed. Western blot was used for the determination of Wnt/ß-catenin and nuclear factor-κB (NF-κB) pathways. HOXA-AS2 expression was decreased in sepsis patients, animal operation group and LPS-irritated HK-2 cells. Overexpressed HOXA-AS2 mollified LPS-triggered impairment in HK-2 cells. In addition, a negative mediatory relation between HOXA-AS2 and miR-106b-5p was predicated. Synchronously, overexpressed miR-106b-5p counteracted the protection of HOXA-AS2 in LPS-damaged HK-2 cells. Ultimately, Wnt/ß-catenin and NF-κB pathways were hindered by HOXA-AS2 via targeting miR-106b-5p. HOXA-AS2 exhibited protection in sepsis-engendered AKI via targeting miR-106b-5p and hindering the Wnt/ß-catenin and NF-κB pathways.

Transcriptomic, proteomic and metabolomic profiling unravel the mechanisms of hepatotoxicity pathway induced by triphenyl phosphate (TPP).

Triphenyl phosphate (TPP) has been found in various environmental media and in biota suggesting widespread human exposure. However, there is still insufficient information on the hepatotoxicity mechanisms of health risk exposed to TPP. In this study, TPP could induce human normal liver cell (L02) apoptosis, injury cell ultrastructure and elevate the levels of reactive oxygen species (ROS). The integrated multi-omic (transcriptomic, proteomic, and metabolomic) analysis was used to further investigate the mechanisms. Transcriptomic analysis revealed that TPP exposure markedly affected cell apoptosis, oncogene activation, REDOX homeostasis, DNA damage and repair. Additionally, proteomic analysis found that the related proteins associated with apoptosis, oxidative stress, metabolism and membrane structure were affected. And metabolomic analysis verified that the related metabolic pathways, such as glycolysis, citrate cycle, oxidative phosphorylation, lipid and protein metabolism, were also significantly disrupted. Based on the multi-omic results, a hypothesized network was constructed to discover the key molecular events in response to TPP and illustrate the mechanism of TPP-induced hepatotoxicity in L02 cells. Therefore, molecular responses could be elucidated at multiple biological levels, and multi-omic analysis could provide scientific tools for exploring potential mechanisms of toxicity and chemical risk assessment.

Tissue distribution and functional characterization of mytimacin-4 in Mytilus galloprovincialis.

Antimicrobial peptides (AMPs) play fundamental roles in the innate immunity of invertebrates. Mytimacin-4 is a kind of AMP gene previously sequenced from Mytilus galloprovincialis based on an identified EST sequence in our lab. In the present study, the tissue distribution and antimicrobial activities of mytimacin-4 were further investigated. A qRT-PCR analysis revealed that mytimacin-4 transcripts were constitutively expressed in all of the tested tissues of M. galloprovincialis, with the highest expression level in the posterior adductor muscle. After challenge by Vibrio anguillarum, the expression level of mytimacin-4 gene was significantly increased at 24 h (P < 0.05) in the mantle and increased at 48 h (P < 0.05) in the posterior adductor muscle. This finding suggested that mytimacin-4 transcripts were inducible upon pathogen infection. A minimal inhibitory concentration (MIC) assay indicated that recombinant mytimacin-4 protein had potent antimicrobial activities against gram-positive and gram-negative bacteria. Among the tested microorganisms, mytimacin-4 protein exhibited strong inhibition activities against Bacillus subtilis and Vibrio parahaemolyticus with MICs of 0.315 µM and 0.62 µM, respectively. This study provides for the first time direct evidence of antimicrobial action of mytimacin-4 in M. galloprovincialis.

Dose-dependent effects induced by cadmium in polychaete Perinereis aibuhitensis.

Cadmium is a known metal contaminant in the Bohai Sea. In this study, the dose-dependent responses induced by Cd were characterized in marine polychaete Perinereis aibuhitensis using the endpoints, including activities of enzymes, expression levels of stress-responsive genes and metabolic responses. Both enzyme activities and gene expression levels exhibited the hormetic effects induced by Cd in P. aibuhitensis, as shown by the typical U-shaped or inverted U-shaped response profiles. The highest concentration (1280 µg/L) of Cd exposure induced obvious oxidative stresses. NMR-based metabolomics revealed that Cd induced both linear dose-dependent effects (69.13% of the total variation) and a relatively slight hormesis (5.54% of the total variation) in energy metabolism in P. aibuhitensis at metabolite level. In details, Cd exposures linearly reduced the consumption of amino acids and enhanced the consumption of glucose for energy supply, resulting in elevated contents of amino acids and depleted contents of glucose. Additionally, Cd treatments induced hormesis in the conversion of ATP hydrolysis to AMP. This work suggested that the hormetic effects should be considered in the ecological risk assessment for the environmental pollutants.

Digital gene expression analysis in the gills of Ruditapes philippinarum after nitrite exposure.

Due to the overload of pollutants from highly intensive anthropic activities, nitrite accumulates in offshore seawater and has been a long-lasting pollutant to the healthy aquaculture of the mollusk. In the present study, Ruditapes philippinarum was used as the target bivalve to receive nitrite exposure at environmental concentration for 1 and 7 days. Differentially expressed genes (DEGs) were detected and analyzed by a digital gene expression (DGE) approach to describe the toxicity of nitrite on the bivalve at the gene level. In the N1 group, 185 DEGs were generated and enriched in six Gene Ontology (GO) terms, including oxidoreductase activity, heme binding, tetrapyrrole binding, iron ion binding, metal binding and cation binding. The DEGs in the N1 group were also enriched in two Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways, e.g., arachidonic acid metabolism and ovarian steroidogenesis. In the N7 group, 81 DEGs were generated without any GO enrichment but were enriched in five KEGG pathways, including protein processing in the endoplasmic reticulum, protein export, prion diseases, thyroid hormone synthesis and arachidonic acid metabolism. This suggested that nitrite exposure might cause adverse effects to the clams in several aspects, including oxidative damage, depressed immunity, and disorders in cell proliferation, hormone metabolism and tissue regeneration. Evaluation of oxidative stress indicated that nitrite exposure actually induced redox state imbalance by enhancing the contents of thiobarbituric acid reactive substances (TBARSs) and glutathione (GSH), and the activity of glutathione peroxidase (GSH-PX) but not superoxide dismutase (SOD). These results will provide valuable gene references for further study on the toxicology mechanism of bivalves under environmental nitrite stress.

A defensin-like antimicrobial peptide from the manila clam Ruditapes philippinarum: Investigation of the antibacterial activities and mode of action.

Defensins are small cysteine-rich cationic proteins that are ubiquitously present in both vertebrates and invertebrates and constitute the front line of host innate immunity. In the present study, a defensin-like antimicrobial peptide (designed as RpdefB) was identified and characterized from the manila clam Ruditapes philippinarum. The open reading frame of RpdefB encoded a 70-amino acid polypeptide with a calculated molecular mass of 7.5 kDa and isoelectric point of 8.16. Multiple alignments and phylogenetic analysis strongly suggested that RpdefB was a new member of the defensin family. In non-stimulated clams, RpdefB transcripts were constitutively expressed in all five tested tissues, especially in the hepatopancreas. After Vibrio anguillarum challenge, expression of RpdefB mRNA in hemocytes was significantly up-regulated at 6 h, 12 h and 72 h. The synthetic peptide RpdefB showed high antibacterial activity against the Gram-negative bacterium Vibrio splendidus. Moreover, membrane integrity analysis revealed that RpdefB increased the membrane permeability of Escherichia coli and then resulted in cell death. Overall, our results suggested that RpdefB played an important role in the elimination of invading bacterium, perhaps through membrane-disruptive activity.

Metabolite and gene expression responses in juvenile flounder Paralichthys olivaceus exposed to reduced salinities.

Seawater salinity is one of the most important changeable environmental factors influencing the behavior, survival, growth and production of marine organisms. In this work, metabolite and gene expression profiles were used to elucidate the biological effects of reduced salinities in juvenile flounder Paralichthys olivaceus. Metabolic profiling indicated that both reduced salinities (23.3‰ and 15.6‰) enhanced proteolysis and disturbed osmotic regulation and energy metabolism in juvenile flounder P. olivaceus. Furthermore, the low salinity (15.6‰) enhanced anaerobic metabolism indicated by the elevated lactate in flounder tissue extracts. Gene expression profiles exhibited that reduced salinities could induce immune stress and oxidative stress and disturb energy metabolism in juvenile flounder P. olivaceus. In addition, reduced salinities might promote the growth and gonadal differentiation in juvenile flounder P. olivaceus.

Molecular characterization, expression and functional analysis of two Kazal-type serine protease inhibitors from Venerupis philippinarum.

Kazal-type serine protease inhibitors (KSPIs) act as negative regulators in immune signaling pathway by controlling the extent of serine protease (SP) activities. In this study, the full-length cDNA of two KSPIs (designed as VpKSPI-1 and VpKSPI-2) were identified from Venerupis philippinarum by rapid amplification of cDNA ends (RACE) approaches. The open reading frame (ORF) of VpKSPI-1 and VpKSPI-2 was of 552 bp and 402 bp, encoding a polypeptide of 183 and 133 amino acids, respectively. The transcripts of VpKSPI-1 and VpKSPI-2 were ubiquitously expressed in all tissues tested with the highest expression level in hepatopancreas. After Vibrio anguillarum challenge, the relative mRNA expression of VpKSPI-1 and VpKSPI-2 in hepatopancreas was both up-regulated within 96 h. The recombinant VpKSPI-1 (rVpKSPI-1) displayed weak activities towards chymotrypsin, moderate inhibitory activity to trypsin, while rVpKSPI-2 showed significant inhibitory activities against chymotrypsin and trypsin. When the molar ratio of rVpKSPI-2 to chymotrypsin and trypsin reached 1:4 and 1:2, the protease activities could be almost entirely inhibited. All these results suggested that both VpKSPI-1 and VpKSPI-2 perhaps play a vital role in the innate immunity of V. philippinarum.