Efficient coupling of sulfadiazine removal with microalgae lipid production in a membrane photobioreactor.

This study explored the feasibility of a coupled system for antibiotic removal and biofuel production through microalgae cultivation. Initial, batch culture experiments demonstrated that sulfadiazine (SDZ) had an inhibitory effect on Chlorella sp. G-9, and 100.0 mg L-1 SDZ completely inhibited its growth. In order to improve SDZ removal efficiency by microalgae, three membrane photobioreactors (MPBRs) with different hydraulic retention times (HRTs) were established for continuous microalgae cultivation. The efficient coupling of SDZ removal and microalgal lipid production was achieved through the gradual increment of influent SDZ concentration from 0 to 100.0 mg L-1. The reduction in SDZ ranged between 57.8 and 89.7%, 54.7-91.7%, and 54.6-93.5% for the MPBRs with HRT of 4 d, 2 d, and 1 d, respectively. Chlorella sp. Was found to tolerate higher concentrations of SDZ in the MPBR system, and the resulting stress from high concentrations of SDZ effectively increased the lipid content of microalgae for potential biodiesel production. With the increase of influent SDZ concentration from 0 to 100.0 mg L-1, the lipid content of microalgae increased by 43.5%. Chlorophyll content, superoxide dismutase activity, and malondialdehyde content of microalgae were also evaluated to explore the mechanism of microalgae tolerance to SDZ stress in MPBR.

Efficient microalgal lipid production driven by salt stress and phytohormones synergistically.

In this study, a novel method of coupling phytohormones with saline wastewater was proposed to drive efficient microalgal lipid production. All the six phytohormones effectively promoted microalgae growth in saline wastewater, and further increased the microalgal lipid content based on salt stress, so as to achieve a large increase in microalgal lipid productivity. Among the phytohormones used, abscisic acid had the most significant promoting effect. Under the synergistic effect of 20 g/L salt and 20 mg/L abscisic acid, the microalgal lipid productivity reached 3.7 times that of the control. Transcriptome analysis showed that differentially expressed genes (DEGs) of microalgae in saline wastewater were mainly up-regulated under the effects of phytohormones except brassinolide. Common DEGs analysis showed that phytohormones all regulated the expression of genes related to DNA repair and substance synthesis. In conclusion, synergistic effect of salt stress and phytohormones can greatly improve the microalgal lipid production efficiency.

Rheum officinale Baill. Treats zebrafish embryo thrombosis by regulating NOS3 expression in the arginine biosynthesis pathway.

BACKGROUND: Rheum officinale Baill. (ROB), as one of the traditional Chinese medicines for promoting blood circulation and removing blood stasis, has a wide range of pharmacological effects, such as cardiovascular protection, and has become a common drug in the clinical care of thrombosis. OBJECTIVE: Although there are some pharmacological studies on ROB in the treatment of thrombotic diseases, the mechanism and material basis are still unclear. Based on the arginine biosynthesis signalling pathway, this research explored the target proteins and metabolites related to the intervention of ROB in thrombosis and expounded on the antithrombotic mechanism of ROB from the comprehensive perspectives of target prediction, intermediate metabolites and potential metabolic pathways. METHODS: In this research, ultraperformance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS) technology was used to qualitatively detect the chemical compounds of ROB, and the antithrombotic activity of ROB was evaluated by establishing a zebrafish model. The target function was predicted by network pharmacology, and differential metabolites were screened by metabolomics and multivariate statistical analysis methods. Correlation analysis of network pharmacology and metabolomics screening results was conducted to identify the potential pathway of ROB intervention in thrombosis, and the prediction results were further verified. RESULTS: ROB significantly reduced the reactive oxygen species (ROS) staining intensity in zebrafish induced by phenylhydrazine (PHZ) and improved the inhibition rate of thrombosis. By constructing the "herb-disease-component-target" network, it was concluded that the active ingredients of ROB in treating thrombosis involved emodin, aloe-emodin and physcion, and the key targets included nitric oxide synthase 2 (NOS2) and nitric oxide synthase 3 (NOS3). A total of 341 differential metabolites in zebrafish with thrombosis were screened by partial least squares discriminant analysis (PLS-DA). The results of reverse transcription-polymerase chain reaction (RT-PCR) experiments and targeted metabolomics verification showed that ROB was mainly involved in improving thrombosis by upregulating the expression of NOS3 mRNA and regulating the levels of arginine, glutamate and glutamine in the arginine biosynthesis pathway. CONCLUSIONS: ROB improved thrombosis by regulating the expression of NOS3 mRNA and the contents of arginine, glutamate and glutamine in the arginine biosynthesis signalling pathway.

Poria cum Radix Pini Rescues Barium Chloride-Induced Arrhythmia by Regulating the cGMP-PKG Signalling Pathway Involving ADORA1 in Zebrafish.

The traditional Chinese medicine Poria cum Radix Pini (PRP) is a fungal medicinal material that has been proven to play an important role in the treatment of arrhythmia. However, the mechanism of its effect on arrhythmia is still unclear. In this study, network pharmacology and metabolomics correlation analysis methods were used to determine the key targets, metabolites and potential pathways involved in the effects of PRP on arrhythmia. The results showed that PRP can significantly improve cardiac congestion, shorten the SV-BA interval and reduce the apoptosis of myocardial cells induced by barium chloride in zebrafish. By upregulating the expression of the ADORA1 protein and the levels of adenosine and cGMP metabolites in the cGMP-PKG signalling pathway, PRP can participate in ameliorating arrhythmia. Therefore, we believe that PRP shows great potential for the treatment of arrhythmia.

Anti-miR33 therapy improved hepatopancreatic lipid and immune metabolism disorders in grass carp, Ctenopharyngodon idella.

Lipid metabolism disorders are found ubiquitously in farmed fish and occur as a result of excessive fat accumulation. Previous studies have found that miR-33 is involved in lipid metabolism; however, its role in fish lipid metabolism is unclear. We sought to clarify this relationship in grass carp in vivo and in vitro. Our findings revealed the length of miR-33 to be 65 bp. Phylogenetic tree analysis showed that grass carp miR-33 was most closely related to fish miR-33 (Siganus canaliculatus). Hepatocytes transfected with miR-33 mimic displayed markedly raised TG content (P < 0.05) as well as increased levels of lipid synthesis-related transcription factors (P < 0.05). Compared with blank and saline groups, total serum cholesterol, AST, and LDL levels were suppressed in groups treated with the miR-33 antagomir (P < 0.05). Moreover, the expression levels of PPARγ and SREBP-1c mRNA were significantly decreased in contrast to those found in the control group (P < 0.05). Similar findings were noted in the expression of immune-related proinflammatory molecules (TNFα, IL-1ß, IL-6, and NF-κB), which also demonstrated decreased levels (P < 0.05). Conversely, high expressions of anti-inflammatory factors (TGF-ß1 and IL-10) were noted (P < 0.05). This investigation strongly supports the role of miR-33 in hepatopancreas-based lipid metabolism and immunity. miR-33 may have been highly conserved in early vertebrates in order to facilitate liver-specific metabolic and immunomodulatory functions. Our findings provide a basis for further investigations exploring the mechanisms surrounding fish lipid metabolism and may aid in preventing and treating immunocompromised fish as well as fish with fatty hepatopancreas, and other metabolic diseases.

Grape seed proanthocyanidin extract ameliorates hepatic lipid accumulation and inflammation in grass carp (Ctenopharyngodon idella).

Hepatic lipid metabolism disorder due to excessive fat accumulation in fish is a significant problem in aquaculture. Studies have shown that grape seed procyanidin extract (GSPE) can regulate fish lipid metabolism and improve fish immunity. However, the mechanism is unclear. In this study, we used grass carp that stores excess fat in the liver as a model. In vitro, GSPE treatment of hepatocytes for 3 h significantly decreased TG content, accompanied with decreased expression of SREBP-1c, FAS, and ACC and increased expression of PPARα, ATGL, and LPL. GSPE treatment for 1 h significantly decreased expression of pro-inflammatory cytokines (TNFα, IL-6, IL-1ß, and NF-κB) and increased the expression of anti-inflammatory cytokines (IL-10 and TGF-ß1). In vivo, the administration of GSPE significantly reduced high-fat diet-induced increase of serum CHOL, TG, and HDL, but increased LDL content. GSPE treatment for 3 h increased expression of ATGL and LPL, and significantly decreased the expression of HFD-fed-induced SREBP-1c, ACC, FAS, PPARγ, PPARα, and H-FABP. GSPE treatment for 3 h also significantly decreased the expression of pro-inflammatory cytokines (TNFα, IL-6, and IL-1ß) and increased the expression of the anti-inflammatory cytokine IL-10. The expression levels of the lipogenic miRNAs, miR-33, and miR-122, were suppressed both in vivo and in vitro by GSPE. In summary, GSPE had hypolipidemic and potential anti-inflammatory effects in the liver, potentially mediated by miR-33 and miR-122.

Enhancing Attention by Synchronizing Respiration and Fingertip Pressure: A Pilot Study Using Functional Near-Infrared Spectroscopy.

Sustained attention is a fundamental ability ensuring effective cognitive processing and can be enhanced by meditation practice. However, keeping a focused meditative state is challenging for novices because involuntary mind-wandering frequently occurs during their practice. Inspired by the potential of force-control tasks in invoking internal somatic attention, we proposed a haptics-assisted meditation (HAM) to help reduce mind-wandering and enhance attention. During HAM, participants were instructed to maintain awareness on the respiration and meanwhile adjust bimanual fingertip pressures to keep synchronized with the respiration. This paradigm required somatosensory attention as a physiological foundation, aiming to help novices meditate starting with the body and gradually gain essential meditation skills. A cross-sectional study on 12 novices indicated that the participants reported less mind-wandering during HAM compared with the classic breath-counting meditation (BCM). In a further longitudinal study, the experimental group with 10 novices showed significantly improved performance in several attentional tests after 5 days' practice of HAM. They tended to show more significant improvements in a few tests than did the control group performing the 5-day BCM practice. To investigate the brain activities related to HAM, we applied functional near-infrared spectroscopy (fNIRS) to record cerebral hemodynamic responses from the prefrontal and sensorimotor cortices when performing HAM, and we assessed the changes in cerebral activation and functional connectivity (FC) after the 5-day HAM practice. The prefrontal and sensorimotor regions demonstrated a uniform activation when performing HAM, and there was a significant increase in the right prefrontal activation after the practice. We also observed significant changes in the FC between the brain regions related to the attention networks. These behavioral and neural findings together provided preliminary evidence for the effectiveness of HAM on attention enhancement in the early stage of meditation learning.

A fluorescence method for determination of glucose transport by intestinal BBMV of common carp.

Epithelial brush-border membrane vesicles (BBMVs) were isolated from the intestine of common carp and studied systematically by enzyme activity, transmission electron microscopy and immunoblotting. The uptake time course and the substrate concentration effect were assessed, and then, the ability of phlorizin and cytochalasin B to inhibit uptake was analyzed. The results show that sucrase, alkaline phosphatase and Na+-K+-ATPase activities in these vesicles were enriched 7.94-, 6.74- and 0.42-fold, respectively, indicating a relatively pure preparation of apical membrane with little basolateral contamination. The vesicular structure was in complete closure, as confirmed by electron microscopy. The presence of SGLT1 on the BBMVs was confirmed by Western blot analysis. In the time course experiment, the glucose uptake by BBMVs in Na+ medium displayed an initial accumulation (overshoot) at 5 min followed by a rapid return to equilibrium values at 60 min. Over the 2-NBDG concentration range selected, the external 2-NBDG concentration in NaSCN medium graphed as a curved line. Phlorizin and cytochalasin B had an obvious inhibitory effect on 2-NBDG transport in carp BBMVs, and the detected fluorescence intensity decreased. The inhibition rate in the 1000 µM group was the strongest at 64.18% and 63.61% of phlorizin and cytochalasin B, respectively, indicating the presence of carriers other than SGLT1. This study is the first to demonstrate that 2-NBDG can be used as a convenient and sensitive probe to detect glucose uptake in fish BBMVs. This technology will provide a convenient method to discover new effects and factors in glucose metabolism.

Zinc mediates the SREBP-SCD axis to regulate lipid metabolism in Caenorhabditis elegans.

Maintenance of lipid homeostasis is crucial for cells in response to lipid requirements or surplus. The SREBP transcription factors play essential roles in regulating lipid metabolism and are associated with many metabolic diseases. However, SREBP regulation of lipid metabolism is still not completely understood. Here, we showed that reduction of SBP-1, the only homolog of SREBPs in Caenorhabditis elegans, surprisingly led to a high level of zinc. On the contrary, zinc reduction by mutation of sur-7, encoding a member of the cation diffusion facilitator (CDF) family, restored the fat accumulation and fatty acid profile of the sbp-1(ep79) mutant. Zinc reduction resulted in iron overload, which thereby directly activated the conversion activity of stearoyl-CoA desaturase (SCD), a main target of SREBP, to promote lipid biosynthesis and accumulation. However, zinc reduction reversely repressed SBP-1 nuclear translocation and further downregulated the transcription expression of SCD for compensation. Collectively, we revealed zinc-mediated regulation of the SREBP-SCD axis in lipid metabolism, distinct from the negative regulation of SREBP-1 or SREBP-2 by phosphatidylcholine or cholesterol, respectively, thereby providing novel insights into the regulation of lipid homeostasis.

[The effect of GDNF on matrix-degrading and cell-adhesion during perineural invasion of salivary adenoid cystic carcinoma].

PURPOSE: To investigate the possible contribution of GDNF in matrix-degrading, cell-adhesion during perineural invasion (PNI) of salivary adenoid cystic carcinoma (ACC). METHODS: Totally 42 ACCs and 5 normal salivary tissues were included in the present study．Immunohistochemical staining SP method was used to detect the expression of GDNF,MMP-9,NF-κB,integrin ß1 in ACC specimens and normal salivary tissues. Statistical analysis was performed using SPSS16.0 software package. RESULTS：GDNF was strongly expressed in ACC tumor cells and nerve fibers adjacent to ACC tumor cells. NF-κB, MMP-9, integrin ß1 were positively expressed in ACC cell cytoplasm, integrin ß1 was also found in ACC cell membrane, and NF-κB in nuclei occasionally. The positive expression rate was 69.05%（29/42）,66.67%（28/42）,61.90%（26/42）, respectively. The differences between the expression of NF-κB, MMP-9, integrinß1 in PNI group and non-PNI group were significant (P=0.005,P=0.011,P=0.001, respectively). Expression of NF-κB, MMP-9, integrin ß1 was correlated to that of GDNF(r=0.443, P=0.003; r=0.401, P=0.009; r=0.535, P=0.000, respectively). Expression of MMP-9 and integrin ß1 was positively correlated to that of NF-κB(r=0.501, P=0.001; r=0.429, P=0.005). Expression of MMP-9 was correlated positively to that of integrin ß1 (r=0.381, P=0.013). CONCLUSIONS：GDNF may increase the matrix-degrading and cell-adhesion of ACC in the process of PNI. NF-κB, MMP-9 and integrin ß1 involve in ACC cells invading nerves.

Retinoid-binding proteins: similar protein architectures bind similar ligands via completely different ways.

BACKGROUND: Retinoids are a class of compounds that are chemically related to vitamin A, which is an essential nutrient that plays a key role in vision, cell growth and differentiation. In vivo, retinoids must bind with specific proteins to perform their necessary functions. Plasma retinol-binding protein (RBP) and epididymal retinoic acid binding protein (ERABP) carry retinoids in bodily fluids, while cellular retinol-binding proteins (CRBPs) and cellular retinoic acid-binding proteins (CRABPs) carry retinoids within cells. Interestingly, although all of these transport proteins possess similar structures, the modes of binding for the different retinoid ligands with their carrier proteins are different. METHODOLOGY/PRINCIPAL FINDINGS: In this work, we analyzed the various retinoid transport mechanisms using structure and sequence comparisons, binding site analyses and molecular dynamics simulations. Our results show that in the same family of proteins and subcellular location, the orientation of a retinoid molecule within a binding protein is same, whereas when different families of proteins are considered, the orientation of the bound retinoid is completely different. In addition, none of the amino acid residues involved in ligand binding is conserved between the transport proteins. However, for each specific binding protein, the amino acids involved in the ligand binding are conserved. The results of this study allow us to propose a possible transport model for retinoids. CONCLUSIONS/SIGNIFICANCE: Our results reveal the differences in the binding modes between the different retinoid-binding proteins.

[Effect of nerve growth factor on adhesion and motional abilities of tumor cells and their correlation].

OBJECTIVE: To investigate the effect on adhesion and motion capbilities of adenoid cystic carcinoma (ACC), by detecting the expression of nerve growth factor (NGF), E-cadherin (E-cad) and S100A4 and the clinical significance in ACC tissues and analyzing the relationships between them with perineural invasion (PNI). METHODS: The expression of NGF, E-cad and S100A4 in ACC was detected with the way of immunohistochemistry SP, and then analyzing the expression level of them in different pathological types and histological regions in statistical ways on the basis of their relation with clinical and pathological parameters. RESULTS: The expression of NGF and S100A4 in PNI group [88% (23/26) and 77% (20/26)], was higher than that in NPNI group (8/16 and 7/16, P < 0.05), and a positive correlation between them was identified in PNI group (r = 0.316, P < 0.05). However the E-cad expression was lower in PNI group [31% (8/26), P < 0.05]. On the other hand it suggested a negative correlation with NGF (r = 0.385, P < 0.05) as well as that with S100A4 (r = -0.612, P = 0.000). The expression level of NGF in fasciculus [83% (25/30)] has significant deviation compared with it in distant tumor tissues [47% (14/30), P < 0.05]. CONCLUSIONS: In the PNI process of ACC, NGF plays important parts but not the only factor. It can increase the expression and activity of S100A4 but decrease E-cad expression through binding with its receptor. Thus, adhesion abilities of tumor cells was weakened and motional abilities was strengthen.

[The measurement of cutting forces in full crown preparation with three-dimensional transducer unit].

OBJECTIVE: To measure the cutting forces applied by clinicians during preparing full crown and to provide basic data for the training of dentistry in a virtual reality. METHODS: Each of six prosthodontists and six dental students prepared three extracted maxillary premolars. The cutting forces were measured with a three-dimensional transducer unit. Differences in cutting time and forces between groups were analyzed with independent-samples t-test. RESULTS: The cutting forces varied in the range from 0.10 N to 4.90 N. The average cutting force (1.71 N) of four axial surfaces was higher than that (0.45 N) of occlusal surface (including functional cusp inclines) (P < 0.01). The cutting time by prosthodontists was shorter than that by the students (P < 0.05). Moreover, the vertical component of the cutting force was higher than the horizontal one (P < 0.01). CONCLUSIONS: The magnitude of cutting forces could be greatly influenced by the motion direction and tendency of the handpiece. The data on cutting forces might serve as the foundation of cutting simulation algorithm for training in a virtual reality.