PTP-MEG2 regulates quantal size and fusion pore opening through two distinct structural bases and substrates.

Tyrosine phosphorylation of secretion machinery proteins is a crucial regulatory mechanism for exocytosis. However, the participation of protein tyrosine phosphatases (PTPs) in different exocytosis stages has not been defined. Here we demonstrate that PTP-MEG2 controls multiple steps of catecholamine secretion. Biochemical and crystallographic analyses reveal key residues that govern the interaction between PTP-MEG2 and its substrate, a peptide containing the phosphorylated NSF-pY83 site, specify PTP-MEG2 substrate selectivity, and modulate the fusion of catecholamine-containing vesicles. Unexpectedly, delineation of PTP-MEG2 mutants along with the NSF binding interface reveals that PTP-MEG2 controls the fusion pore opening through NSF independent mechanisms. Utilizing bioinformatics search and biochemical and electrochemical screening approaches, we uncover that PTP-MEG2 regulates the opening and extension of the fusion pore by dephosphorylating the DYNAMIN2-pY125 and MUNC18-1-pY145 sites. Further structural and biochemical analyses confirmed the interaction of PTP-MEG2 with MUNC18-1-pY145 or DYNAMIN2-pY125 through a distinct structural basis compared with that of the NSF-pY83 site. Our studies thus provide mechanistic insights in complex exocytosis processes.

Multifunctional organic nanomaterials with ultra-high photothermal conversion efficiency for photothermal therapy and inhibition of cancer metastasis.

Photothermal therapy (PTT) has gained extensive interest in tumor treatments due to its non-invasive and low-toxic nature. However, the currently available photothermal agents (PTAs) mostly show unsatisfactory photothermal conversion efficiency (PCE). Besides, as a local cancer treatment modality, PTT fails to inhibit metastasis of tumors. To address these issues, in this study, two aza-boron-dipyrromethene (aza-BODIPY)-based organic photothermal agents (OPTAs), Fc-aza-BODIPY and TPA-aza-BODIPY, were rationally coined by introducing two strong electron-donating ferrocene (Fc) moieties and two triphenylamine (TPA) rotors, which could boost intramolecular photo-induced electron transfer (PET) and molecular rotation respectively, thereby improving the PCE of aza-BODIPY dyes. After encapsulation of hydrophobic Fc-aza-BODIPY (or TPA-aza-BODIPY) and quercetin with biodegradable PLGA and DSPE-mPEG2000, the resulting nanoparticles (FAQ NPs and TAQ NPs) showed excellent optical properties with PCE of ∼72.0% and ∼79.7% and specific tumor accumulations through enhanced permeability and retention (EPR) effects. Consequently, these two NPs possessed prominent antitumor effects under 880 nm laser irradiation. Moreover, both FAQ NPs and TAQ NPs loaded with quercetin could inhibit tumor metastasis efficiently. These two multifunctional nanomaterials integrating OPTAs and anti-metastasis agents constructed a cooperative treatment program, which may provide a potential opportunity for future clinical cancer treatment.

EYA2 suppresses the progression of hepatocellular carcinoma via SOCS3-mediated blockade of JAK/STAT signaling.

BACKGROUND: Somatic mutations are involved in hepatocellular carcinoma (HCC) progression, but the genetic mechanism associated to hepatocarcinogenesis remains poorly understood. We report that Eyes absent homolog 2 (EYA2) suppresses the HCC progression, while EYA2(A510E) mutation identified by exome sequencing attenuates the tumor-inhibiting effect of EYA2. METHODS: Whole-exome sequencing was performed on six pairs of human HCC primary tumors and matched adjacent tissues. Focusing on EYA2, expression level of EYA2 in human HCC samples was evaluated by quantitative real-time PCR, western blot and immunohistochemistry. Loss- and gain-of-function studies, hepatocyte-specific deletion of EYA2 (Eya2-/-) in mice and RNA sequencing analysis were used to explore the functional effect and mechanism of EYA2 on HCC cell growth and metastasis. EYA2 methylation status was evaluated using Sequenom MassARRAY and publicly available data analysis. RESULTS: A new somatic mutation p.Ala510Glu of EYA2 was identified in HCC tissues. The expression of EYA2 was down-regulated in HCC and associated with tumor size (P = 0.001), Barcelona Clinic Liver Cancer stage (P = 0.016) and tumor differentiation (P = 0.048). High level of EYA2 was correlated with a favorable prognosis in HCC patients (P = 0.003). Results from loss-of-function and gain-of-function experiments suggested that knockdown of EYA2 enhanced, while overexpression of EYA2 attenuated, the proliferation, clone formation, invasion, and migration of HCC cells in vitro. Delivery of EYA2 gene had a therapeutic effect on inhibition of orthotopic liver tumor in nude mice. However, EYA2(A510E) mutation led to protein degradation by unfolded protein response, thus weakening the inhibitory function of EYA2. Hepatocyte-specific deletion of EYA2 in mice dramatically promoted diethylnitrosamine-induced HCC development. EYA2 was also down-regulated in HCC by aberrant CpG methylation. Mechanically, EYA2 combined with DACH1 to transcriptionally regulate SOCS3 expression, thus suppressing the progression of HCC via SOCS3-mediated blockade of the JAK/STAT signaling pathway. CONCLUSIONS: In our study, we identified and validated EYA2 as a tumor suppressor gene in HCC, providing a new insight into HCC pathogenesis.

Comparison of Safety and Efficacy of Different Models of Target Vessel Regional Chemotherapy for Gastric Cancer with Liver Metastases.

BACKGROUND/AIMS: We previously demonstrated the safety and efficacy of low-dose, short-interval target vessel regional chemotherapy (TVRC(LDSI)) delivered through the hepatic artery with transarterial embolization (TAE) in patients with advanced gastric cancer (AGC). The present study aimed to compare the efficacy of TAE + TVRC(LDSI) with that of standard TAE + TVRC in AGC patients with liver metastases who failed to respond to first- or second-line systemic chemotherapy. METHODS: This study recruited a total of 58 GC patients with liver metastases after failure of first- or second-line systemic chemotherapy. Twenty-eight patients were assigned to the TAE + TVRC(LDSI) group and 30 patients to the TAE + TVRC group. The primary end point was overall survival (OS(TVRC)), which was defined as the time from the initiation of TVRC until the last follow-up or death. RESULTS: OS(TVRC), time to progression (TTP) until appearance of intra- and extrahepatic metastases, and overall TTP and treatment periods in the TAE + TVRC(LDSI) group were all significantly longer than in the TAE + TVRC group (all p < 0.001). CONCLUSION: TAE + TVRC(LDSI) had a higher efficacy and safety, which was reflected by OS rates, progression-free survival rates, longer duration of treatment and milder side effects compared to standard TAE + TVRC.

4,4'-(Ethene-1,2-di-yl)dipyridinium 4-[2-(pyridin-4-yl)ethen-yl]pyridinium octa-cyanidomolybdate(V) tetra-hydrate.

The crystal structure of the title compound, (C12H12N2)(C12H11N2)[Mo(CN)8]·4H2O, consists of 4,4'-(ethene-1,2-di-yl)dipyridinium and 4-[2-(pyridin-4-yl)ethen-yl]pyridinium cations disordered over the same site, an [Mo(CN)8](3-) anion and four water mol-ecules of crystallization. The eight-coordinate [Mo(CN)8](3-) unit exhibits a slightly distorted square-anti-prismatic geometry. In the structure, the cations (crystallographic symmetry, 2) and anions (crystallographic symmetry, 222) are arranged alternately by N-H⋯O and O-H⋯N hydrogen bonds, forming layers parallel to the bc plane. These layers are further linked through O-H⋯N hydrogen bonds, generating a three-dimensional supra-molecular network.

Self-Reporting Molecular Prodrug for In Situ Quantitative Sensing of Drug Release by Ratiometric Photoacoustic Imaging.

Understanding the pharmacokinetics of prodrugs in vivo necessitates quantitative, noninvasive, and real-time monitoring of drug release, despite its difficulty. Ratiometric photoacoustic (PA) imaging, a promising deep tissue imaging technology with a unique capacity for self-calibration, can aid in solving this problem. Here, for the first time, a methylamino-substituted Aza-BODIPY (BDP-N) and the chemotherapeutic drug camptothecin (CPT) are joined via a disulfide chain to produce the molecular theranostic prodrug (BSC) for real-time tumor mapping and quantitative visualization of intratumoral drug release using ratiometric PA imaging. Intact BSC has an extremely low toxicity, with a maximum absorption at ∼720 nm; however, endogenous glutathione (GSH), which is overexpressed in tumors, will cleave the disulfide bond and liberate CPT (with full toxicity) and BDP-N. This is accompanied by a significant redshift in absorption at ∼800 nm, resulting in the PA800/PA720 ratio. In vitro, a linear relationship is successfully established between PA800/PA720 values and CPT release rates, and subsequent experiments demonstrate that this relationship can also be applied to the quantitative detection of intratumoral CPT release in vivo. Notably, the novel ratiometric strategy eliminates nonresponsive interference and amplifies the multiples of the signal response to significantly improve the imaging contrast and detection precision. Therefore, this research offers a viable alternative for the design of molecular theranostic agents for the clinical diagnosis and treatment of tumors.

A promising strategy for synergistic cancer therapy by integrating a photosensitizer into a hypoxia-activated prodrug.

Herein, we fabricate a multifunctional molecular prodrug BAC where the chemotherapeutical agent camptothecin (CPT) is linked with a boron dipyrromethene (BODIPY)-based photosensitizer by an azobenzene chain which is sensitive to over-expressed azoreductase in hypoxic tumor cells. This prodrug was further loaded into biodegradable monomethoxy poly(ethylene glycol)-b-poly(caprolactone) (mPEG-b-PCL) to improve its solubility and tumor accumulation. The formed BAC nanoparticles (BAC NPs) can destroy aerobic tumor cells with relatively short distance from blood vessels by photodynamic therapy (PDT) under illumination. The PDT action inevitably leads to consumption of O2, and subsequently acute hypoxia which can induce cleavage of azobenzene linkage to boost release of CPT killing the other hypoxic interior tumor cells survived from PDT. Both in vitro and in vivo studies have verified that BAC NPs possess remarkable antitumor activity by a synergistic action of PDT and chemotherapy.

Effects of miR-143 and its target receptor 5-HT2B on agonistic behavior in the Chinese mitten crab (Eriocheir sinensis).

Chinese mitten crab (Eriocheir sinensis) as a commercially important species is widely cultured in China. However, E. sinensis is prone to agonistic behavior, which causes physical damage and wastes energy resources, negatively impacting their growth and survival. Therefore, understanding the regulatory mechanisms that underlie the switching of such behavior is essential for ensuring the efficient and cost-effective aquaculture of E. sinensis. The 5-HT2B receptor is a key downstream target of serotonin (5-HT), which is involved in regulating animal behavior. In this study, the full-length sequence of 5-HT2B gene was cloned. The total length of the 5-HT2B gene was found to be 3127 bp with a 236 bp 5'-UTR (untranslated region), a 779 bp 3'-UTR, and a 2112 bp open reading frame encoding 703 amino acids. Phylogenetic tree analysis revealed that the 5-HT2B amino acid sequence of E. sinensis is highly conserved with that of Cancer borealis. Using in vitro co-culture and luciferase assays, the miR-143 targets the 5-HT2B 3'-UTR and inhibits 5-HT2B expression was confirmed. Furthermore, RT-qPCR and Western blotting analyses revealed that the miR-143 mimic significantly inhibits 5-HT2B mRNA and protein expression. However, injection of miR-143 did not decrease agonistic behavior, indicating that 5-HT2B is not involved in the regulation of such behavior in E. sinensis.

UBE2S interacting with TRIM28 in the nucleus accelerates cell cycle by ubiquitination of p27 to promote hepatocellular carcinoma development.

Genomic sequencing analysis of tumors provides potential molecular therapeutic targets for precision medicine. However, identifying a key driver gene or mutation that can be used for hepatocellular carcinoma (HCC) treatment remains difficult. Here, we performed whole-exome sequencing on genomic DNA obtained from six pairs of HCC and adjacent tissues and identified two novel somatic mutations of UBE2S (p. Gly57Ala and p. Lys63Asn). Predictions of the functional effects of the mutations showed that two amino-acid substitutions were potentially deleterious. Further, we observed that wild-type UBE2S, especially in the nucleus, was significantly higher in HCC tissues than that in adjacent tissues and closely related to the clinicopathological features of patients with HCC. Functional assays revealed that overexpression of UBE2S promoted the proliferation, invasion, metastasis, and G1/S phase transition of HCC cells in vitro, and promoted the tumor growth significantly in vivo. Mechanistically, UBE2S interacted with TRIM28 in the nucleus, both together enhanced the ubiquitination of p27 to facilitate its degradation and cell cycle progression. Most importantly, the small-molecule cephalomannine was found by a luciferase-based sensitive high-throughput screen (HTS) to inhibit UBE2S expression and significantly attenuate HCC progression in vitro and in vivo, which may represent a promising strategy for HCC therapy.

The transcriptome sequencing and functional analysis of eyestalk ganglions in Chinese mitten crab (Eriocheir sinensis) treated with different photoperiods.

Photoperiod plays an important role in individual growth, development, and metabolism in crustaceans. The growth and reproduction of crabs are closely related to the photoperiod. However, as of yet, there are still no transcriptomic reports of eyestalk ganglions treated under different photoperiods in the Chinese mitten crab (Eriocheir sinensis), which is a benthonic crab with high commercial value in Asia. In this study, we collected the eyestalk ganglions of crabs that were reared under different photoperiods, including a control group (L: D = 12 h: 12 h, named CC), a constant light group (L: D = 24 h: 0 h, named LL) and a constant darkness group (L: D = 0 h: 24 h, named DD). RNA sequencing was performed on these tissues in order to examine the effects of different photoperiods. The total numbers of clean reads from the CC, LL and DD groups were 48,772,584 bp, 53,943,281 bp and 53,815,178 bp, respectively. After de novo assembly, 161,380 unigenes were obtained and were matched with different databases. The DEGs were significantly enriched in phototransduction and energy metabolism pathways. Results from RT-qPCR showed that TRP channel protein (TRP) in the phototransduction pathway had a significantly higher level of expression in LL and DD groups than in the CC group. We found that the downregulation of the pyruvate dehydrogenase complex (PDC) gene and the upregulation phosphoenolpyruvate carboxykinase (PPC) gene were involved in energy metabolism processes in LL or DD. In addition, we also found that the upregulation of the expression level of the genes Gαq, pyruvate kinase (PK), NADH peroxidase (NADH) and ATPase is involved in phototransduction and energy metabolism. These results may shed some light on the molecular mechanism underlying the effect of photoperiod in physiological activity of E. sinensis.

5-HT2B, 5-HT7, and DA2 Receptors Mediate the Effects of 5-HT and DA on Agonistic Behavior of the Chinese Mitten Crab (Eriocheir sinensis).

The Chinese mitten crab (Eriocheir sinensis) is a commercially important crab in China and is usually managed at high stocking densities. Agonistic behavior directly impacts crab integrity, survival, and growth and results in economic losses. In the present study, we evaluated the modulatory effects of serotonin (5-HT) and dopamine (DA) though the 5-HT2 and DA2 receptor-cyclic adenosine monophosphate (cAMP)-protein kinase A (PKA) pathway on agonistic behavior. The results showed that injection of either 10-6 mol/crab 5-HT or DA reduced the agonistic behavior of E. sinensis (P < 0.05), as did 10-10 mol/crab DA and 10-8 mol/crab 5-HT and DA (P < 0.05); however, a dose of 10-10 mol/crab 5-HT promoted agonistic behavior. 5-HT significantly increased the mRNA expression level of 5-HT7 receptor and reduced that of the DA2 receptor in the cerebral ganglion (P < 0.05). In contrast to 5-HT, DA significantly decreased 5-HT2B mRNA levels and increased 5-HT7 and DA2 receptor levels in the thoracic ganglia (P < 0.05). In addition, injections of either 5-HT or DA increased the cAMP and PKA levels in hemolymph (P < 0.05). By using in vitro culture of the thoracic ganglia, the current study showed that ketanserin (5-HT2 antagonist) and [R(-)-TNPA] (DA2 agonist) had obvious effects on the expression levels of the two receptors (P < 0.05). In vivo experiments further demonstrated that ketanserin and [R(-)-TNPA] could both significantly reduce the agonistic behavior of the crabs (P < 0.05). Furthermore, both ketanserin and [R(-)-TNPA] promoted the cAMP and PKA levels (P < 0.05). The injection of CPT-cAMP (cAMP analogue) elevated the PKA levels and inhibited agonistic behavior. In summary, this study showed that 5HT-2B and DA2 receptors were involved in the agonistic behavior that 5-HT/DA induced through the cAMP-PKA pathway in E. sinensis.

The serotonin or dopamine by cyclic adenosine monophosphate-protein kinase A pathway involved in the agonistic behaviour of Chinese mitten crab, Eriocheir sinensis.

Agonistic behaviour is common in an encounter between two crustaceans. It often causes limb disability and consumes a lot of energy, which is harmful for the growth and survival of commercially important crustaceans. In the present study, we mainly focused on the agonistic behaviour of the Chinese mitten crab, Eriocheir sinensis, which is an important species of the aquaculture industry in China. We recorded agnostic behaviour with a high-definition camera and preliminarily evaluated the role of serotonin (5-HT) or dopamine (DA)-cyclic adenosine monophosphate (cAMP)-protein kinase A (PKA) pathway and eyestalk in the behaviour. The results showed that agonistic behaviour in E. sinensis consisted of three stages: approach, contact and fight. We found that the number of fights and cumulative time of fight were significantly higher in the male vs. male group than in the female vs. female and female vs. male groups (P < 0.05). After 1 h of agonistic behaviour, 5-HT concentration showed a significant increase and DA concentration showed a significant decrease when compared with the control group (no encounter; P < 0.05). 5-HT1B and 5-HT2B mRNA levels showed a significant increase in the eyestalk (P < 0.05). 5-HT7 mRNA levels showed significant downregulation in the thoracic ganglia and DA1A mRNA levels showed upregulation in the intestine (P < 0.05). DA2 mRNA levels showed a significant decrease in the eyestalk (P < 0.05). These changes were accompanied by a significant increase in cAMP level and significant decrease in PKA level in the haemolymph (P < 0.05). In addition, a significant decrease in glucose levels was detected after the agonistic behaviour. Crustacean hyperglycemic hormone (CHH) mRNA levels showed significant upregulation in the eyestalk and significant downregulation in the intestine (P < 0.05). The number of fights and cumulative time of fight in the left eyestalk ablation (L-X vs. L-X) group were more and longer than those in the intact eyestalk (C vs. C), right eyestalk ablation (R-X vs. R-X) and bilateral eyestalk ablation (D-X vs. D-X) groups. In short, E. sinensis shows special agonistic behaviour modulated by 5-HT or DA-cAMP-PKA pathway and eyestalk, especially the left eyestalk.

Changes in bud morphology, growth-related genes and nutritional status during cheliped regeneration in the Chinese mitten crab, Eriocheir sinensis.

During pond culture of Eriocheir sinensis, a high limb-impairment rate restricts the industry development and quality. Therefore, research on limb autotomy and regeneration has important practical significance for the industrial development and basic biology of E. sinensis. This study evaluated the changes in bud morphology, growth-related gene expression and nutritional status during cheliped regeneration in E. sinensis. The study found that the new cheliped was pre-formed in the bud and then regenerated with the completion of molting of E. sinensis. The new cheliped was similar in morphology to the normal cheliped after the first molting but smaller in size. The qRT-PCR results of growth-related genes showed that the expression levels of EcR-mRNA (ecdysteroid receptor) and Chi-mRNA (chitinase) were significantly up-regulated, whereas the expression of MIH-mRNA (molt-inhibiting hormone) was significantly down-regulated (P < 0.05). The nutritional status during the regeneration process showed that the hepatopancreas total lipid content decreased significantly within 28 days and was significantly lower in the autotomy group than in the control group at 14 d and 21 d (P < 0.05). The hepatopancreas fatty acid composition results showed that saturated fatty acids (SFA), highly unsaturated fatty acids (HUFA) and n-3/n-6 were significantly higher in the autotomy group than in the control group at 21 d (P < 0.05), whereas the ∑ n-6 PUFA and ∑ n-3 PUFA at 1 d and 7 d, and the monounsaturated fatty acid (MUFA) at 28 d in the autotomy group were significantly lower than in the control group (P < 0.05). Moreover, the levels of eicosatetraenoic acid (ARA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) showed that DHA was significantly lower at 7 d and significantly higher at 21 d in the autotomy group than in the control group (P < 0.05), whereas ARA and EPA were not significantly different between the two groups. Muscle L-tryptophan content was significantly lower at 1 d and significantly higher at 7 d in the autotomy group than in the control group (P < 0.05). These results indicate that during the cheliped regeneration process, crabs could accelerate molting and regeneration by regulating growth-related gene expression (e.g., EcR-mRNA and MIH-mRNA) and nutrient metabolism (e.g., lipid metabolism).

[Effects of Wastewater Nitrogen Concentrations and NH4+/NO3- on Nitrogen Removal Ability and the Nitrogen Component of Myriophyllum aquaticum (Vell.) Verdc].

Solution culture experiments were conducted to investigate the effect of wastewater nitrogen levels and NH4+/NO3- on nitrogen removal ability and the nitrogen component of Myriophyllum aquaticum. Experiments with three nitrogen levels and NH4+/NO3- were set up as follows:20, 100, and 200 mg·L-1and NH4+/NO3- 1:0, 0.5:0.5, and 0:1. The results showed that the biomass of plants increased fastest during the first week. The plants treated with NH4+/NO3-=1:0 with nitrogen levels of 20 and 100 mg·L-1 and those treated with NH4+/NO3-=0.5:0.5 with a nitrogen concentration of 200 mg·L-1 exhibited higher biomass than the others. The removal rates of water total nitrogen, ammonium nitrogen, and nitrate nitrogen during the first week were the maximum for all treatments and increased with water nitrogen levels. There were no significant differences in the removal rate between ammonium nitrogen and nitrate nitrogen with a nitrogen level of 20 mg/L, while with nitrogen levels of 100 and 200 mg·L-1, the nitrate removal rates were higher than those for ammonium nitrogen. The Myriophyllum aquaticum nitrogen accumulation and its contribution rate to nitrogen removal from water and sediment were all increased with water nitrogen levels and increased fastest during the first week. The contribution rate of nitrogen accumulated by plants with NH4+/NO3-=0:1 was the highest with nitrogen levels of 20 mg·L-1, while plants with NH4+/NO3-=0.5:0.5 were the highest with nitrogen levels of 100 and 200 mg·L-1. The protein, amino, and nitrate nitrogen contents in Myriophyllum aquaticum plants were all increased by increasing water nitrogen levels with a ranking of protein content > amino nitrogen content > nitrate nitrogen content. The protein concentrations in plants with NH4+/NO3-=1:0 and NH4+/NO3-=0.5:0.5 were higher regardless of water nitrogen levels, while the amino nitrogen concentration in plants with NH4+/NO3-=1:0 and the nitrate nitrogen content in plants with NH4+/NO3-=0:1 were higher than the others. It was concluded that the nitrogen removal ability of Myriophyllum aquaticum was improved by raising water nitrogen levels under the tested condition, which indicates that Myriophyllum aquaticum could purify high nitrogen wastewater. Myriophyllum aquaticum is an ammonium-nitrophile, but had the strongest capacity for growing and removing wastewater nitrogen exhibited with higher than 100 mg·L-1 nitrogen levels only with equal NH4+ to NO3-. The nitrogen component concentrations of protein, amino, and nitrate in Myriophyllum aquaticum plant were all affected by the ratio of NH4+/NO3-.

Cellular and biochemical parameters following autotomy and ablation-mediated cheliped loss in the Chinese mitten crab, Eriocheir sinensis.

In the pond culture of juvenile Eriocheir sinensis, various factors have frequently led to a high rate of autotomy and limb impairments. This study evaluated the differential effects of cheliped loss with autotomy and ablation on the short-term cellular and biochemical parameters of juvenile E. sinensis. In this study, compared with the crabs before treatment, the total hemocyte counts (THC), granulocyte counts (GC), hemocyte agglutination, phosphatase activity and glucose metabolism levels were significantly increased, while hyalinocyte counts (HC) and total antioxidant capacity (T-AOC) were significantly decreased within 3 h. However, the THC levels, hemocyte agglutination and hemocyte proliferation were significantly higher in the ablation group within 3 h compared to the autotomy group. Moreover, the changes of glucose metabolism and immune-related enzymes activities in ablation groups were later than autotomy groups. The bacterial challenge showed that the mortality rate of the ablation group was significantly higher than that of the autotomy group. Therefore, the observations in this study indicate that compared with the passive trauma response of ablation, autotomy is a congenital, efficient, and active trauma response mechanism, which is of great significance to the survival and growth of E. sinensis.

Melatonin Promotes Cheliped Regeneration, Digestive Enzyme Function, and Immunity Following Autotomy in the Chinese Mitten Crab, Eriocheir sinensis.

In the pond culture of juvenile Eriocheir sinensis, a high limb-impairment rate seriously affects the culture success. Therefore, it is particularly important to artificially promote limb regeneration. This study evaluated the effects of melatonin on cheliped regeneration, digestive ability, and immunity, as well as its relationship with the eyestalk. It was found that the injection of melatonin significantly increased the limb regeneration rate compared with the saline group (P < 0.05). The qRT-PCR results of growth-related genes showed that the level of EcR-mRNA (ecdysteroid receptor) and Chi-mRNA (chitinase) expression was significantly increased following the melatonin injection, while the expression of MIH-mRNA (molt-inhibiting hormone) was significantly decreased (P < 0.05). Melatonin significantly increased lipase activity (P < 0.05). We observed that the survival rates of limb-impaired and unilateral eyestalk-ablated crabs were substantially improved following melatonin treatment, whereas the survival of the unilateral eyestalk-ablated crabs was significantly decreased compared with the control group (P < 0.05). Furthermore, the results of serum immune and antioxidant capacity revealed that melatonin significantly increased the total hemocyte counts (THC), hemocyanin content, total antioxidant capacity (T-AOC), acid phosphatase (ACP), and glutathione peroxidase activity (GSH-Px), whereas the immune-related parameters were significantly decreased in eyestalk-ablated crabs (P < 0.05). Therefore, these findings indicate that melatonin exerts a protective effect on organism injury, which could promote limb regeneration by up-regulating the expression of growth-related genes, improve digestive enzyme activity, and strengthen the immune response, particularly antioxidant capacity.

[Effect of Wastewater Nitrogen Concentrations on Nitrogen Removal Ability of Myriophyllum aquaticum].

Myriophyllum aquaticum, which is an important plant for constructed wetlands, has powerful purification ability for wastewater, however, the relationship between nitrogen removal ability of Myriophyllum aquaticum and wastewater nitrogen concentrations is still unclear. In this study, pot culture experiment was conducted to investigate the effect of wastewater nitrogen levels on nitrogen removal ability of Myriophyllum aquaticum. 7 nitrogen levels were set up as following:2, 5, 10, 20, 100, 200, 400 mg·L-1. The results showed that when the wastewater nitrogen concentration was not higher than 20 mg·L-1, Myriophyllum aquaticum with 20 mg·L-1 of nitrogen concentration grew best in the first 3 weeks; the removal rates of total and ammonia nitrogen were nearly 100% after one week, while the nitrate nitrogen concentrations were very low and varied little; the nitrogen contents of Myriophyllum aquaticum had no significant change, the upper part nitrogen content was higher than the underneath, Myriophyllum aquaticum could also remove nitrogen from the sediment. When wastewater nitrogen concentrations were 100-400 mg·L-1, Myriophyllum aquaticum with 200 mg·L-1 of nitrogen concentration grew best from 4th to 5th week; the removal rates of total nitrogen were 76.5%, 71.5% and 48.1% in the three treatments, and the removal rates of ammonia nitrogen were 99.6%, 99.3% and 60.2% respectively, while the removal rates of nitrate nitrogen were all about 50% and there was no significant difference among treatments; the nitrogen contents of Myriophyllum aquaticum increased with nitrogen levels, but the difference between upper part and underneath was not remarkable, showing uniform distribution; nitrogen accumulations by Myriophyllum aquaticum and sediment accounted for 27.9%-48.4% and 12.2%-24.4% of total nitrogen loss in wastewater. Therefore, the nitrogen removal ability of Myriophyllum aquaticum should be inhibited by higher wastewater nitrogen level, the ammonia nitrogen removal rate was significantly higher than nitrate, the mechanism of Myriophyllum aquaticum nitrogen accumulation and distribution should also be affected by wastewater nitrogen level, and further research is needed.

Silver nanoparticles induce oocyte maturation in zebrafish (Danio rerio).

Public concern regarding silver nanoparticles (AgNPs) in the environment has been increasing since they can cause adverse effects in some aquatic species. However, few data are actually available on the effects of AgNPs on the germ cells. In the present study, we used the zebrafish ovarian follicle as a model to assess the potentially adverse effects of AgNPs on oocyte maturation (germinal vesicle breakdown, GVBD) in vitro. Similar to the maturation inducing hormone (17α, 20ß-dihydroxy-4-pregnen-3-one), AgNPs induced GVBD, and reduced the total cyclic adenosine monophosphate (cAMP) concentration in zebrafish ovarian follicles. The results from transmission electron microscope observation and Hoechst 33342 staining clearly indicated that AgNPs induced apoptosis in ovarian follicle cells surrounding the oocyte. Similar to AgNPs, AgNO3 also induced GVBD, decreased cAMP concentration and induced apoptosis of ovarian follicle cells. However, the results from gene expression analysis showed that transcript levels of oxidative stress related genes were more sensitive to AgNPs than AgNO3. Further more, H2O2 has an ability to induce zebrafish oocytes maturation by induction of apoptosis in ovarian follicle cells. Taken together, the results from our study indicated that oxidative stress appeared to be one of important mechanisms in AgNP induced apoptosis in ovarian follicle cells, which further triggered the GVBD.

Lanthanide-ion-tuned magnetic properties in a series of three-dimensional cyano-bridged Ln(III)W(V) assemblies.

The reaction of [W(CN)(8)](3-) with Ln(3+) and pyrazine in acetonitrile yielded a series of isostructural compounds formulated as Ln(H(2)O)(4)(pyrazine)(0.5)W(CN)(8) (Ln = La(1), Ce(2), Pr(3), Nd(4), Sm(5), Eu(6), Gd(7)). The Ln(III) and W(V) centers in the structure are linked through cyanide groups to form two-dimensional (2D) layers, which are further pillared by pyrazine, generating 3D frameworks. The magnetic behavior for compounds 1-7 were driven by the lanthanide ions involved. The Ln(III) and W(V) ions in compounds 2 and 5 are ferromagnetically coupled with magnetic ordering occurring at 2.8 K, comparable with magnetic ordering with the critical temperature of 1.9 K for compound 4. In addition, the antiferromagnetic interactions were observed in compounds 3 and 7, while no significant magnetic couplings were found in compounds 1 and 6.