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PloS One 2017Tmem88a is a transmembrane protein that is thought to be a negative regulator of the Wnt signalling pathway. Several groups have used antisense morpholino... (Comparative Study)
Comparative Study
Tmem88a is a transmembrane protein that is thought to be a negative regulator of the Wnt signalling pathway. Several groups have used antisense morpholino oligonucleotides in an effort to characterise the role of tmem88a in zebrafish cardiovascular development, but they have not obtained consistent results. Here, we generate an 8 bp deletion in the coding region of the tmem88a locus using TALENs, and we have gone on to establish a viable homozygous tmem88aΔ8 mutant line. Although tmem88aΔ8 mutants have reduced expression of some key haematopoietic genes, differentiation of erythrocytes and neutrophils is unaffected, contradicting our previous study using antisense morpholino oligonucleotides. We find that expression of the tmem88a paralogue tmem88b is not significantly changed in tmem88aΔ8 mutants and injection of the tmem88a splice-blocking morpholino oligonucleotide into tmem88aΔ8 mutants recapitulates the reduction of erythrocytes observed in morphants using o-Dianisidine. This suggests that there is a partial, but inessential, requirement for tmem88a during haematopoiesis and that morpholino injection exacerbates this phenotype in tmem88a morpholino knockdown embryos.
Topics: Amino Acid Sequence; Animals; Animals, Genetically Modified; Base Sequence; Embryo, Nonmammalian; Gene Expression Regulation, Developmental; Gene Knockdown Techniques; Hematopoietic System; In Situ Hybridization; Membrane Proteins; Morpholinos; Mutation; Phenotype; Phylogeny; Reverse Transcriptase Polymerase Chain Reaction; Sequence Homology, Amino Acid; Sequence Homology, Nucleic Acid; Zebrafish; Zebrafish Proteins
PubMed: 28192479
DOI: 10.1371/journal.pone.0172227 -
Chemistry & Biodiversity Dec 2023The aim of this study was to examine a collection of 79 honeys derived from plants endemic to several Western Australian unique bioregions for bioactivity and...
The aim of this study was to examine a collection of 79 honeys derived from plants endemic to several Western Australian unique bioregions for bioactivity and physicochemical characteristics. For physicochemical analyses, total phenolic content, high performance thin layer chromatography (HPTLC) fingerprints, pH, Brix, colour and hydrogen peroxide generation were examined. Brix (82.6±1.3) and pH (4.34±0.24) values were within expected ranges, whereas hydrogen peroxide levels determined using an o-dianisidine/horseradish peroxidase assay were relatively low, ranging from 0-244 μM. Antibacterial activity determined by the broth microdilution assay showed that Moort (Eucalyptus platypus) and Yate (Eucalyptus occidentalis) honeys had the highest overall activity with mean minimum inhibitory concentrations of 24.8 % and 25.1 % (w/v) honey, respectively. Yate honey also had the highest overall antioxidant activity (4.38±0.58 mmol Fe /kg of honey), followed by Mallee honeys from various eucalypts, as determined by FRAP (Ferric reducing antioxidant power) and DPPH⋅ (2,2-Diphenyl-1-picrylhydrazyl) assays. This study identified new sources of honeys with potentially useful therapeutic properties from bioregions within Western Australia.
Topics: Western Australia; Honey; Hydrogen Peroxide; Australia; Phenols; Antioxidants; Eucalyptus
PubMed: 37968896
DOI: 10.1002/cbdv.202301678 -
International Journal of Biological... Nov 2017In the present paper, a peroxidase was purified from the leaves of a medicinal tree, namely Azadirachta indica, to 45.2 folds with overall recovery of 61%. Based on the...
In the present paper, a peroxidase was purified from the leaves of a medicinal tree, namely Azadirachta indica, to 45.2 folds with overall recovery of 61%. Based on the subunit size, the purified peroxidase was suggested to be a monomeric structure of size 50kDa and exhibited good thermostability as it was fully stable at 65°C for 1hr and also retained about 73% activity at 70°C till 30min. The substrate affinity was found to be in order of guaiacol>pyrogallol>o-dianisidine. The purified peroxidase was found to be insensitive towards high concentrations of Na, Ca, Mg and Mn. Heavy metals, namely Cs, Co and Cd activated the peroxidase while that of Hg deactivated the peroxidase in concentration dependent manner. The purified peroxidase exhibited tolerance towards organic solvents in order of ethanol>butanol>isopropanol>acetone. Immobilization of purified peroxidase by entrapment into chitosan beads led to shift in its optimum pH from pH 5 to 7 and considerable enhancement in dye decolorization ability as compared to that of free enzyme. Thus, based on all the above properties, it may be suggested that the purified A. indica peroxidase is a promising candidate for industrial applications.
Topics: Azadirachta; Chitosan; Color; Coloring Agents; Enzyme Stability; Enzymes, Immobilized; Hydrogen-Ion Concentration; Kinetics; Metals, Heavy; Molecular Weight; Peroxidase; Salts; Solvents; Temperature
PubMed: 28215563
DOI: 10.1016/j.ijbiomac.2017.02.047 -
Life Sciences May 2024Prolyl hydroxylase domain 2 (PHD2), encoded by the Egln1 gene, serves as a pivotal regulator of the hypoxia-inducible factor (HIF) pathway and acts as a cellular oxygen...
AIMS
Prolyl hydroxylase domain 2 (PHD2), encoded by the Egln1 gene, serves as a pivotal regulator of the hypoxia-inducible factor (HIF) pathway and acts as a cellular oxygen sensor. Somatic inactivation of Phd2 in mice results in polycythemia and congestive heart failure. However, due to the embryonic lethality of Phd2 deficiency, its role in development remains elusive. Here, we investigated the function of two egln1 paralogous genes, egln1a and egln1b, in zebrafish.
MAIN METHODS
The egln1 null zebrafish were generated using the CRISPR/Cas9 system. Quantitative real-time PCR assays and Western blot analysis were employed to detect the effect of egln1 deficiency on the hypoxia signaling pathway. The hypoxia response of egln1 mutant zebrafish were assessed by analyzing heart rate, gill agitation frequency, and blood flow velocity. Subsequently, o-dianisidine staining and in situ hybridization were used to investigate the role of egln1 in zebrafish hematopoietic function.
KEY FINDINGS
Our data show that the loss of egln1a or egln1b individually has no visible effects on growth rate. However, the egln1a; egln1b double mutant displayed significant growth retardation and elevated mortality at around 2.5 months old. Both egln1a-null and egln1b-null zebrafish embryo exhibited enhanced tolerance to hypoxia, systemic hypoxic response that include hif pathway activation, increased cardiac activity, and polycythemia.
SIGNIFICANCE
Our research introduces zebrafish egln1 mutants as the first congenital embryonic viable systemic vertebrate animal model for PHD2, providing novel insights into hypoxic signaling and the progression of PHD2- associated disease.
Topics: Animals; Mice; Hypoxia; Hypoxia-Inducible Factor 1, alpha Subunit; Hypoxia-Inducible Factor-Proline Dioxygenases; Polycythemia; Procollagen-Proline Dioxygenase; Zebrafish
PubMed: 38492922
DOI: 10.1016/j.lfs.2024.122564 -
Analytical Chemistry Dec 2019This study reports a microfluidic chip-based wearable colorimetric sensor for detecting sweat glucose. The device consisted of five microfluidic channels branching out...
This study reports a microfluidic chip-based wearable colorimetric sensor for detecting sweat glucose. The device consisted of five microfluidic channels branching out from the center and connected to the detection microchambers. The microchannels could route the sweat excreted from the epidermis to the microchambers, and each of them was integrated with a check valve to avoid the risk of the backflow of the chemical reagents from the microchamber. The microchambers contained the pre-embedded glucose oxidase (GOD)-peroxidase--dianisidine reagents for sensing the glucose in sweat. It was found that the color change caused by the enzymatic oxidation of -dianisidine could show a more sensitive response to the glucose than that of the conventional GOD-peroxidase-KI system. This sensor could perform five parallel detections at one time. The obtained linear range for sweat glucose was 0.1-0.5 mM with a limit of detection of 0.03 mM. The sensor was also used to detect the glucose in sweat samples from a group of subjects engaged in both fasting and postprandial trials. The results showed that our wearable colorimetric sensor can reveal the subtle differences existing in the sweat glucose concentration after the fasting and the oral glucose uptake.
Topics: Adult; Biosensing Techniques; Colorimetry; Dianisidine; Epidermis; Fasting; Glucose; Glucose Oxidase; Healthy Volunteers; Humans; Lab-On-A-Chip Devices; Limit of Detection; Peroxidase; Postprandial Period; Sweat; Wearable Electronic Devices
PubMed: 31553565
DOI: 10.1021/acs.analchem.9b03110 -
PloS One 2017We have previously shown that (1) an acute deficiency in blood serum holo-ceruloplasmin (Cp) developed in rats that were fed fodder containing silver ions (Ag-fodder)...
We have previously shown that (1) an acute deficiency in blood serum holo-ceruloplasmin (Cp) developed in rats that were fed fodder containing silver ions (Ag-fodder) for one month and (2) the deficiency in holo-Cp was compensated by non-hepatic holo-Cp synthesis in rats that were chronically fed Ag-fodder for 6 months (Ag-rats). The purpose of the present study is to identify the organ(s) that compensate for the hepatic holo-Cp deficiency in the circulation. This study was performed on rats that were fed Ag-fodder (40 mg Ag·kg-1 body mass daily) for 6 months. The relative expression levels of the genes responsible for copper status were measured by RT-PCR. The in vitro synthesis and secretion of [14C]Cp were analyzed using a metabolic labeling approach. Oxidase activity was determined using a gel assay with o-dianisidine. Copper status and some hematological indexes were measured. Differential centrifugation, immunoblotting, immunoelectrophoresis, and atomic absorption spectrometry were included in the investigation. In the Ag-rats, silver accumulation was tissue-specific. Skeletal muscles and internal (IAT) and subcutaneous (SAT) adipose tissues did not accumulate silver significantly. In SAT, the mRNAs for the soluble and glycosylphosphatidylinositol-anchored ceruloplasmin isoforms were expressed, and their relative levels were increased two-fold in the Ag-rats. In parallel, the levels of the genes responsible for Cp metallation (Ctr1 and Atp7a/b) increased correspondingly. In the SAT of the Ag-rats, Cp oxidase activity was observed in the Golgi complex and plasma membrane. Moreover, full-length [14C]Cp polypeptides were released into the medium by slices of SAT. The possibilities that SAT is part of a system that controls the copper balance in mammals, and it plays a significant role in supporting copper homeostasis throughout the body are discussed.
Topics: Animals; Ceruloplasmin; Copper; Female; Immunoblotting; Immunoprecipitation; Male; Muscle, Skeletal; Rats; Rats, Wistar; Silver; Subcutaneous Fat
PubMed: 28380026
DOI: 10.1371/journal.pone.0175214 -
Gene Jan 2015Fruit ripening associated full length cDNA of a peroxidase from papaya was cloned and heterologously expressed. The expressed peroxidase was activated by in-vitro...
Fruit ripening associated full length cDNA of a peroxidase from papaya was cloned and heterologously expressed. The expressed peroxidase was activated by in-vitro re-folding in the presence of hemin and calcium. The purified recombinant peroxidase exhibited broad substrate affinity in the order of o-dianisidine>pyrogallol>guaiacol and was found to be a homotetramer of 155kDa with each subunit having a size of 38kDa. The basis of the distinctive preferences for various substrates was investigated through in-silico molecular modeling approaches. Thus, when the modeled papaya peroxidase-heme complex was docked with these substrates, the in-silico binding efficiency was found to be in agreement with those of wet lab results with the involvement of Arg37, Phe40, His41, Pro137, Asn138, His139, His167, and Phe239 as the common interacting residues in all the cases. However, the binding of the different substrates were found to be associated with conformational changes in the peroxidase. Thus, in the case of o-dianisidine (the most efficient substrate), the protein was folded in the most compact fashion when compared to guaiacol (the least efficient substrate). Protein function annotation analyses revealed that the papaya peroxidase may have biological roles in oxidation-reduction processes, stresses, defense responses etc. In order to further validate its role in lignifications, the papaya peroxidase was compared with a lignin biosynthetic peroxidase from Leucaena leucocephala, a tree legume. Thus, based on 3D structure superimposition and docking, both peroxidases exhibited a great extent of similarity suggesting the papaya peroxidase having a role in lignification (defense response) too. The predicted functions of papaya peroxidase in defense response and lignification were further validated experimentally using qRT-PCR analyses and measurement of oxidation of coniferyl alcohol.
Topics: Amino Acid Sequence; Carica; Chromatography, Affinity; Cloning, Molecular; DNA, Complementary; Dianisidine; Escherichia coli; Guaiacol; Heme; Hydrogen-Ion Concentration; Molecular Docking Simulation; Molecular Sequence Data; Peroxidases; Plant Proteins; Protein Folding; Protein Structure, Secondary; Protein Structure, Tertiary; Pyrogallol; Real-Time Polymerase Chain Reaction; Recombinant Proteins; Substrate Specificity; Temperature
PubMed: 25447898
DOI: 10.1016/j.gene.2014.11.013 -
Bioprocess and Biosystems Engineering Feb 2017In this study, laccase was immobilized on nylon 6,6/Fe composite (NFC) nanofibrous membrane and used for the detoxification of 3,3'-dimethoxybenzidine (DMOB). The...
In this study, laccase was immobilized on nylon 6,6/Fe composite (NFC) nanofibrous membrane and used for the detoxification of 3,3'-dimethoxybenzidine (DMOB). The average size and tensile strength of the NFC membrane were found to be 60-80 nm (diameter) and 2.70 MPa, respectively. The FTIR results confirm that the amine (N-H) group of laccase was attached with Fe particles and the carbonyl (C=O) group of NFC membrane via hydrogen bonding. The half-life of the laccase-NFC membrane storage stability was increased from 6 to 11 weeks and the reusability was significantly extended up to 43 cycles against ABTS oxidation. Enhanced electro-oxidation of DMOB by laccase was observed at 0.33 V and the catalytic current was found to be 30 µA. The DMOB-treated mouse fibroblast 3T3-L1 preadipocytes showed maximum (97 %) cell inhibition at 75 µM L within 24 h. The cytotoxicity of DMOB was significantly decreased to 78 % after laccase treatment. This study suggests that laccase-NFC membrane might be a good candidate for emerging pollutant detoxification.
Topics: 3T3-L1 Cells; Animals; Caprolactam; Dianisidine; Enzymes, Immobilized; Ferric Compounds; Fungal Proteins; Laccase; Membranes, Artificial; Mice; Nanofibers; Polymers; Trametes
PubMed: 27757535
DOI: 10.1007/s00449-016-1686-6 -
Journal of Environmental Management May 2019Studies on the oxidation products of organic pollutants and their toxicity in textile dyeing sludge after the sludge was treated by the advance oxidation processes were...
Studies on the oxidation products of organic pollutants and their toxicity in textile dyeing sludge after the sludge was treated by the advance oxidation processes were limited, since textile dyeing sludge was a complicated mixture. For the first time, simulated sludge was used to study the degradation mechanism of 3,3'-dimethoxybenzidine (DMB) during the combined ultrasound-Mn(VII) treatment. The toxicity of DMB and its products was also evaluated. The results indicated that the compositions and microstructures of polyaluminium chloride (PAC)- and polyferric sulphate (PFS)-based simulated sludge were similar to those of real textile dyeing sludge. The optimum conditions of ultrasound-Mn(VII) treatment were: a KMnO dosage of 40 μM, an ultrasound power density of 0.36 W cm, and a reaction time of 20 min. 98.24% of DMB and 63.04% of total organic carbon (TOC) in the simulated sludge were removed. Six products, that is, 2-nitroanisole, 3-methoxy-4-nitrophenol, vanillylmandelic acid, vanillyl alcohol, m-anisic acid, and benzoic acid, were identified by GC-MS and LC-MS-MS. It was noted that all of these identified products were also detected in the real textile dyeing sludge after the ultrasound-Mn(VII) treatment. All of them were less toxic than DMB. Moreover, 53.30% and 54.80% of toxicity toward the alga Desmodesmus subspicatus and the bacterium Vibrio fischeri were removed in simulated sludge, respectively. Therefore, simulated sludge was helpful for studying a pollutant's degradation mechanism in the complex sludge mixtures. The results would also provide some useful suggestions for the sludge disposal after the sludge was treated by the advance oxidation processes.
Topics: Dianisidine; Oxidation-Reduction; Sewage; Waste Disposal, Fluid; Water Pollutants, Chemical
PubMed: 30849594
DOI: 10.1016/j.jenvman.2018.11.135 -
Biochemical and Biophysical Research... Jan 2015Hemoglobin synthesis by erythrocytes continues throughout a vertebrate's lifetime. The mechanism of mammalian heme synthesis has been studied for many years;...
Hemoglobin synthesis by erythrocytes continues throughout a vertebrate's lifetime. The mechanism of mammalian heme synthesis has been studied for many years; aminolevulinate synthase 2 (ALAS2), a heme synthetase, is associated with X-linked dominant protoporphyria in humans. Amphibian and mammalian blood cells differ, but little is known about amphibian embryonic hemoglobin synthesis. We investigated the function of the Xenopus alas2 gene (Xalas2) in primitive amphibian erythrocytes and found that it is first expressed in primitive erythroid cells before hemoglobin alpha 3 subunit (hba3) during primary hematopoiesis and in the posterior ventral blood islands at the tailbud stage. Xalas2 is not expressed during secondary hematopoiesis in the dorsal lateral plate. Hemoglobin was barely detectable by o-dianisidine staining and hba3 transcript levels decreased in Xalas2-knockdown embryos. These results suggest that Xalas2 might be able to synthesize hemoglobin during hematopoiesis and mediate erythrocyte differentiation by regulating hba3 expression in Xenopus laevis.
Topics: 5-Aminolevulinate Synthetase; Amino Acid Motifs; Amino Acid Sequence; Animals; Catalytic Domain; Cell Differentiation; Erythrocytes; Erythropoiesis; Gene Expression Regulation, Developmental; Hemangioblasts; Heme; Hemoglobins; Molecular Sequence Data; Oligonucleotides, Antisense; RNA, Messenger; Sequence Homology, Amino Acid; Stem Cells; Xenopus Proteins; Xenopus laevis
PubMed: 25482442
DOI: 10.1016/j.bbrc.2014.11.110