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1.
Molecules ; 29(11)2024 May 24.
Article in English | MEDLINE | ID: mdl-38893356

ABSTRACT

Photocatalysis is one of the most promising pathways to relieve the environmental contamination caused by the rapid development of modern technology. In this work, we demonstrate a green manufacturing process for the 3D/3D rod-shaped bamboo charcoal/Bi2WO6 photocatalyst (210BC-BWO) by controlled carbonization temperature. A series of morphology characterization and properties investigations (XRD, SEM, UV-vis DRS, transient photocurrent response, N2 absorption-desorption isotherms) indicate a 210BC-BWO photocatalyst with higher charge separation efficiency, larger surface area, and better adsorption capacity. The excellent photocatalytic performance was evaluated by degrading rhodamine B (RhB) (98.5%), tetracycline hydrochloride (TC-HCl) (77.1%), and H2 evolution (2833 µmol·g-1·h-1) coupled with furfuryl alcohol oxidation (3097 µmol·g-1·h-1) under visible light irradiation. In addition, the possible mechanisms for degradation of organic pollutants, H2 evolution, and furfuryl alcohol oxidation were schematically investigated, which make it possible to exert photocatalysis by increasing the active radical. This study shows that the combination of bamboo charcoal and bismuth tungstate can be a powerful photocatalyst that rationally combines H2 evolution coupled with furfuryl alcohol oxidation and degradation of pollutants.

2.
ACS Omega ; 8(30): 26882-26894, 2023 Aug 01.
Article in English | MEDLINE | ID: mdl-37546663

ABSTRACT

In this work, a novel two-dimensional/two-dimensional (2D/2D) hybrid photocatalyst consisting of Bi2WO6 (BWO) nanosheets and cotton fibers biochar (CFB) nanosheets was successfully prepared via a facile hydrothermal process. The as-prepared photocatalysts were characterized by a variety of techniques, including X-ray diffraction, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, and UV-vis diffuse reflectance spectroscopy. It was revealed that amorphous CFB nanosheets were uniformly immobilized on the surface of crystalline BWO nanosheets, and an intimate contact between CFB and BWO was constructed. The photocatalytic activities of the prepared BWO and CFB-BWO photocatalysts were evaluated by photocatalytic degradation of rhodamine B (RhB) and tetracycline hydrochloride (TC-HCl) in aqueous solutions under visible-light irradiation. Compared to the pristine BWO, the CFB-BWO composite photocatalysts exhibited significant enhancement in photocatalytic activities. Among all CFB-BWO samples, the 9CFB-BWO sample with the CFB mass ratio of 9% exhibited optimal photocatalytic activities for RhB or TC-HCl degradation, which was ca. 1.8 times or 2.4 times that of the pristine BWO, respectively. The improvement in photocatalytic activities of the CFB-BWO photocatalysts could be ascribed to the enhanced migration and separation of photogenerated charge carriers due to the formation of a 2D/2D interfacial heterostructure between CFB and BWO. Meanwhile, the possible mechanism of CFB-BWO for enhanced photocatalytic performance was also discussed. This work may provide a new approach to designing and developing novel BWO-based photocatalysts for the highly efficient removal of organic pollutants.

3.
Sci Rep ; 12(1): 14796, 2022 08 30.
Article in English | MEDLINE | ID: mdl-36042283

ABSTRACT

Bursaphelenchus xylophilus is a notorious invasive species, causing extensive losses to pine ecosystems globally. Previous studies had shown that the development of B. xylophilus was seriously suppressed by light. However, the mechanism involved in the inhibition is unknown. Here, it is the first report that Bxy-madd-4 is a light-regulated gene, plays a potential role in B. xylophilus in responding to the blue light. Transcriptome sequencing revealed that the expression level of Bxy-madd-4 declined by 86.39% under blue light. The reverse transcription quantitative real-time PCR results were in accord with the transcriptome sequencing, confirming the expression level of Bxy-madd-4 was suppressed by blue light. Bxy-madd-4 promoter::mCherry reporter constructed in Caenorhabditis elegans were utilized to mimic the spatiotemporal expression patterns of Bxy-madd-4. Bxy-madd-4A promoter activity had a strong continuity throughout all development stages in C. elegans. Further RNA interference indicated that only 36.8% of the Bxy-madd-4 dsRNA treated embryos were hatched. Moreover, 71.6% of the hatched nematodes were abnormal, such as particles on the body surface and concave tissues. Our findings contribute towards a better understanding of the mechanism of light against the destructive invasive nematode, providing a promising hint for control of the destructive invasive nematode.


Subject(s)
Caenorhabditis elegans Proteins , Pinus , Rhabditida , Tylenchida , Animals , Caenorhabditis elegans , Ecosystem , Nerve Tissue Proteins , Tylenchida/genetics , Xylophilus
4.
J Hazard Mater ; 421: 126741, 2022 01 05.
Article in English | MEDLINE | ID: mdl-34352526

ABSTRACT

Hydrochar (AAHC) with rich carboxylate groups was prepared by one-step hydrothermal carbonization (HTC) of bamboo and acrylic acid with the presence of ammonium persulphate, and then activated by a sodium hydroxide solution. AAHC was featured by elemental analysis, SEM, XPS, FTIR, Zeta potential analysis and N2 adsorption-desorption isotherms, and applied to test adsorptive ability of methylene blue (MB) by batch sorption experiments. Despite a small Brunauer-Emmett-Teller (BET) surface area of 5.03 m2·g-1, AAHC has excellent MB adsorbing capacity owing to the richness of carboxylate groups. Compared with hydrochar produced without adding ammonium persulphate, AAHC exhibits larger BET surface, pore volume and carboxylate groups, indicating a small amount of ammonium persulfate plays an important role in HTC in addition to the free radical initiator. This work provides a facile and cheap method combining HTC and polymerization for preparation of carboxylate-rich hydrochar.


Subject(s)
Methylene Blue , Water Pollutants, Chemical , Acrylates , Adsorption , Ammonium Sulfate , Methylene Blue/analysis , Water Pollutants, Chemical/analysis
5.
Bioresour Technol ; 323: 124616, 2021 Mar.
Article in English | MEDLINE | ID: mdl-33387711

ABSTRACT

Biochar was prepared by torrefaction of ammonium persulphate pretreated bamboo (labeled as APBC) and applied into elimination of Pb(II) from water solutions. APBC was characterized by N2 adsorption-desorption isotherms, elemental and Zeta potential analyses, SEM-EDS, XPS, and FTIR. Abundant N- and O-containing groups appeared atop APBC. Batch sorption assays revealed that APBC had high affinity and strong sorption ability towards Pb(II). The high Pb(II) adsorbing ability was attributed to the high contents of N- and O-containing functional groups of APBC. The adsorption mechanism mainly occurred by inner-sphere surface complexation. Hence, torrefaction of ammonium persulphate pretreated bamboo is a promising strategy for producing efficient biochar that is applicable for industrial wastewater treatment.


Subject(s)
Lead , Water Pollutants, Chemical , Adsorption , Ammonium Sulfate , Charcoal , Water Pollutants, Chemical/analysis
6.
Pest Manag Sci ; 77(1): 138-147, 2021 Jan.
Article in English | MEDLINE | ID: mdl-32652887

ABSTRACT

BACKGROUND: Bursaphelenchus xylophilus is one of the most destructive invasive species, causing extensive economic losses worldwide. The sex ratio of female to male of B. xylophilus plays an important role in the nematode infestation. However, little is known about the processes of its sex determination. The double sex/mab-3-related family of transcription factors are highly conserved in animals, playing crucial roles in sex determination, spermatogenesis and ontogenesis. We therefore investigated its orthologue, Bxy-mab-3, in B. xylophilus. RESULTS: Bxy-mab-3 has two typical conserved DNA-binding domains. It was observed in J2 (the second-stage of juveniles), J3, J4 and male adults (specifically on the spicules), but not in eggs or female adults via mRNA in situ hybridization. RNA-Seq indicated significantly higher expression in males. RNAi showed that the body size and sperm size of male adults were markedly smaller than those of the controls. Meanwhile, almost all the RNAi-treated males failed to mate with the normal females, even 26.34% of interfered males did not produce sperm. However, RNAi of Bxy-mab-3 had no effect on the sex ratio of B. xylophilus. CONCLUSION: Bxy-mab-3 is indispensable for spermatogenesis, ontogenesis and mating behavior. It is a typical sex-determination gene with differential expression in males and females. However, knocking down Bxy-mab-3 expression could not alter the sex ratio as seen in other species. Our findings contribute towards a better understanding of the molecular events of Bxy-mab-3 in B. xylophilus, which provides promising hints for control of pine wilt disease by blocking ontogenesis and decreasing nematode fecundity.


Subject(s)
Pinus , Rhabditida , Tylenchida , Animals , Female , Male , Spermatogenesis , Tylenchida/genetics , Xylophilus
7.
Pest Manag Sci ; 76(1): 205-214, 2020 Jan.
Article in English | MEDLINE | ID: mdl-31140718

ABSTRACT

BACKGROUND: The pine wood nematode (PWN) Bursaphelenchus xylophilus is the causal agent of pine wilt disease (PWD). This disease is a serious threat to pine forests globally. The fuca gene encodes α-L-fucosidase, which plays crucial roles in numerous biological and pathological processes in bacteria, fungi, plants and animals. To find promising control strategies against PWD, we investigated the expression and functions of Bxy-fuca in B. xylophilus. RESULTS: Bxy-fuca encoding α-L-fucosidase is highly conserved within the deduced functional domains and key residues. It is expressed continuously across all developmental stages of B. xylophilus. mRNA in situ hybridization demonstrated that Bxy-fuca was mainly localized in the body wall muscles and intestine. RNA interference indicated that the zygotic expression of Bxy-fuca was indispensable for embryogenesis. The rate of B. xylophilus egg hatch was significantly decreased after Bxy-fuca was interfered. Postembryonic silence of Bxy-fuca resulted in a dramatic decrease in the longevity of and the total number of eggs produced by B. xylophilus. In addition, the motility of the nematode was greatly hampered with a significant drop in head thrashing frequency. CONCLUSION: Bxy-fuca plays crucial roles in development, lifespan and reproduction of B. xylophilus. Our results provide promising hints for control of PWD by blocking embryogenesis and ontogenesis, decreasing nematode fecundity, and disrupting the connection between B. xylophilus and its vector beetle by preventing nematode movement into the tracheal system. © 2019 Society of Chemical Industry.


Subject(s)
Pinus , Animals , Plant Diseases , Reproduction , alpha-L-Fucosidase
8.
Medicine (Baltimore) ; 97(45): e12924, 2018 Nov.
Article in English | MEDLINE | ID: mdl-30407285

ABSTRACT

BACKGROUND: Postoperative hemorrhage following total-knee arthroplasty (TKA) remains an important topic. The objective of the meta-analysis is to assess the effectiveness of oral antifibrinolytics for blood management in patients undergoing TKA. METHODS: We searched Medline (1966 to August 2018), PubMed (1966 to August 2018), Embase (1980 to August 2018), ScienceDirect (1985 to August 2018), and the Web of Science (1995 to August 2018) for randomized control trials (RCTs). To assess the heterogeneity of study trial and determine the model for analysis (random-effect model or fixed-effect model), I tests and Chi-squared were conducted. We utilized the STATA 12.0 (StataCorp, College Station, TX) to perform all statistical analyses. RESULTS: A total of 5 RCTs met our inclusion criteria. This meta-analysis shows that there are significant differences between the 2 groups regarding total blood loss, hemoglobin reduction, and transfusion rates. In addition, no adverse effects were identified in treatment groups. CONCLUSION: The oral form of antifibrinolytics in TKA is able to significantly decrease blood loss, postoperative hemoglobin reduction, as well as transfusion requirements. No increased risk of postoperative complications was observed. Higher quality RCTs is necessary to confirm our finding.


Subject(s)
Antifibrinolytic Agents/administration & dosage , Arthroplasty, Replacement, Knee/adverse effects , Blood Loss, Surgical/prevention & control , Postoperative Hemorrhage/prevention & control , Tranexamic Acid/administration & dosage , Administration, Oral , Aged , Female , Humans , Male , Middle Aged , Postoperative Hemorrhage/etiology , Treatment Outcome
9.
J Vis Exp ; (118)2016 12 25.
Article in English | MEDLINE | ID: mdl-28060317

ABSTRACT

A method for observing and quantifying the mating behavior of the pinewood nematode, Bursaphelenchus xylophilus, was established under a stereomicroscope. To improve the mating efficiency of B. Xylophilus and to increase the chances of mating observation, virgin adults were cultured and used for the investigation. Eggs were obtained by keeping the nematodes in water and allowing the females to lay eggs for 10 min. The second-stage juveniles (J2) were synchronized by incubating the eggs for 24 h at 25 °C in the dark, and the early J4 were obtained by culturing the J2 with grey mold, Botrytis cinerea, for another 52 h. At this time point, most J4 nematodes could be clearly distinguished as being male or female using their genital morphology. The male and female J4 were collected and cultured separately in two different Petri dishes for 24 h to get virgin adult nematodes. A virgin male and a virgin female were paired in a drop of water in the well of a concave slide. The mating behavior was filmed with a video recorder under a stereomicroscope. The whole period of the mating process was 82.8 ±3.91 min (mean ±SE) and could be divided into 4 different phases: searching, contacting, copulating, and lingering. The mean minutes of duration were 21.8 ± 2.0, 28.0 ± 1.9, 25.8 ± 0.7 and 7.2 ± 0.5, respectively. Eleven sub-behaviors were described: cruising, approaching, encountering, touching, hooping, locating, attaching, ejaculating, separating, quiescence, and roaming. Interestingly, obvious intra-sexual competition was observed when one female was grouped with 3 males or one male with 3 females. This protocol is useful and valuable, not only in investigating the mating behavior of B. xylophilus, but also in acting as a reference for ethological studies of other nematodes.


Subject(s)
Microscopy , Sexual Behavior, Animal , Tylenchida/physiology , Video Recording , Animals , Female , Fungi , Male
10.
J Nematol ; 47(2): 126-32, 2015 Jun.
Article in English | MEDLINE | ID: mdl-26170474

ABSTRACT

To understand the efficacy of emamectin benzoate, avermectin, milbemectin, and thiacloprid on the reproduction and development of Bursaphelenchus xylophilus, seven parameters, namely population growth, fecundity, egg hatchability, larval lethality, percent larval development, body size, and sexual ratio, were investigated using sublethal (LC20) doses of these compounds in the laboratory. Emamectin benzoate treatment led to a significant suppression in population size, brood size, and percent larval development with 411, 3.50, and 49.63%, respectively, compared to 20850, 24.33, and 61.43% for the negative control. The embryonic and larval lethality increased obviously from 12.47% and 13.70% to 51.37% and 75.30%, respectively. In addition, the body length was also significantly reduced for both males and females in the emamectin benzoate treatment. Avermectin and milbemectin were also effective in suppressing population growth by increasing larval lethality and reducing larval development, although they did not affect either brood size or embryonic lethality. Body length for both male and female worms was increased by avermectin. Thiacloprid caused no adverse reproductive effects, although it suppressed larval development. Sexual ratio was not affected by any of these four nematicides. Our results indicate that emamectin benzoate, milbemectin, and avermectin are effective against the reproduction of B. xylophilus. We think these three nematicides can be useful for the control of pine wilt disease.

11.
Intensive Care Med ; 38(11): 1877-85, 2012 Nov.
Article in English | MEDLINE | ID: mdl-23011534

ABSTRACT

PURPOSE: Some of the neuroprotective effects of hydrogen sulfide (H(2)S) have been attributed to systemic hypometabolism and hypothermia. However, systemic metabolism may vary more dramatically than brain metabolism after cardiac arrest (CA). The authors investigated the effects of inhaled exogenous hydrogen sulfide on brain metabolism and neurological function in rabbits after CA and resuscitation. METHODS: Anesthetized rabbits were randomized into a sham group, a sham/H(2)S group, a CA group, and a CA/H(2)S group. Exogenous 80 ppm H(2)S was administered to the sham/H(2)S group and the CA/H(2)S group which suffered 3 min of untreated CA by asphyxia and resuscitation. Effects on brain metabolism (cerebral extraction of oxygen (CEO(2)), arterio-jugular venous difference of glucose [AJVD(glu)] and lactate clearance), S100B, viable neuron counts, neurological dysfunction score, and survival rate were evaluated. RESULTS: CEO(2), AJVD(glu), and lactate increased significantly after CA. Inhalation of 80 ppm H(2)S significantly increased CEO(2) (25.04 ± 7.11 vs. 16.72 ± 6.12 %) and decreased AJVD(glu) (0.77 ± 0.29 vs. 1.18 ± 0.38 mmol/L) and lactate (5.11 ± 0.43 vs. 6.01 ± 0.64 mmol/L) at 30 min after resuscitation when compared with the CA group (all P < 0.05). In addition, neurologic deficit scores, viable neuron counts, and survival rate were significantly better whereas S100B was decreased after H(2)S inhalation. CONCLUSIONS: The present study reveals that inhalation of 80 ppm H(2)S reduced neurohistopathological damage and improves early neurological function after CA and resuscitation in rabbits. The increased CEO(2) and decreased AJVD(glu) and enhanced lactate clearance may be involved in the protective effects.


Subject(s)
Brain Ischemia/prevention & control , Brain/metabolism , Cardiopulmonary Resuscitation/methods , Heart Arrest/drug therapy , Hydrogen Sulfide/therapeutic use , Neuroprotective Agents/therapeutic use , Administration, Inhalation , Animals , Body Temperature , Brain/pathology , Hydrogen Sulfide/administration & dosage , Hydrogen Sulfide/pharmacology , Male , Neuroprotective Agents/administration & dosage , Neuroprotective Agents/pharmacology , Rabbits , Random Allocation , Survival Analysis
12.
J AOAC Int ; 93(5): 1530-6, 2010.
Article in English | MEDLINE | ID: mdl-21140666

ABSTRACT

Celery was found to provoke human allergenic response in some countries. Labeling of celery ingredients was required by the European Union, and the threshold set at 10 mg/kg (0.001%). In our study, a celery mannitol transporter (Mat3) gene-based detection method was established by means of SYBR Green real-time PCR technique. No cross-reactivity was found between celery and the other food materials. Absolute detection limit (LODa), relative detection limit (LODr), and practical detection limit (LODp) of the method were determined through experiments on pure celery DNA, DNA mix, and spiked food samples. The method was able to detect 0.001% raw food sample and 0.01% heated food sample. The utility of the method was confirmed by the investigation of 13 commercial foods.


Subject(s)
Apium/genetics , DNA, Plant/analysis , Food Analysis/methods , Polymerase Chain Reaction/methods , Base Sequence , Benzothiazoles , Diamines , Limit of Detection , Molecular Sequence Data , Organic Chemicals , Quinolines
13.
Gastroenterology ; 134(7): 1994-2003, 2008 Jun.
Article in English | MEDLINE | ID: mdl-18440316

ABSTRACT

BACKGROUND & AIMS: Vesicular glutamate transporter (VGLUT) has been reported to be involved in glucose-induced insulin secretion. It has been shown that glucose stimulates the expression of VGLUT isoform 2 (VGLUT2) in beta cells via transcriptional mechanism. In this study, we identified the mouse VGLUT2 (mVGLUT2) promoter and characterized the transcriptional mechanism of glucose-stimulated mVGLUT2 expression in beta-cells. METHODS: A promoter region of mVGLUT2 was cloned by genomic polymerase chain reaction. The mechanism of Sp1 in glucose-induced transactivation of mVGLUT2 was investigated by luciferase assay, electrophoretic mobility shift assay, chromatin immunoprecipitation assay, and Western blot analysis. RESULTS: A promoter containing 2133 base pairs of upstream sequence of the 5'-flanking region of mVGLUT2 complementary DNA was cloned. Transient transfection of various 5'-end deletion constructs of the mVGLUT2 promoter/luciferase reporter indicated that the region between -96 to +68 base pair contains the basal promoter for mVGLUT2. Mutational analysis and electromobility shift assay showed an important role for the transcription factor Sp1 in both basal and glucose-induced mVGLUT2 transcription. The interaction between Sp1 and mVGLUT2 was confirmed by chromatin immunoprecipitation assays. Glucose stimulates the phosphorylation of Sp1 via mitogen-activated protein kinase P38 and P44/42. This leads to increased binding activity of Sp1 to the mVGLUT2 promoter and results in activation of the gene. CONCLUSIONS: We cloned the mouse VGLUT2 promoter and showed a novel molecular mechanism of glucose-induced mVGLUT2 transcription.


Subject(s)
Glucose/metabolism , Insulin-Secreting Cells/metabolism , Signal Transduction , Sp1 Transcription Factor/metabolism , Transcription, Genetic , Transcriptional Activation , Vesicular Glutamate Transport Protein 2/metabolism , 5' Flanking Region , Amino Acid Sequence , Animals , Blotting, Western , Cell Line , Chromatin Immunoprecipitation , Cloning, Molecular , Electrophoretic Mobility Shift Assay , Genes, Reporter , Insulin-Secreting Cells/enzymology , Mice , Mitogen-Activated Protein Kinase 1/metabolism , Mitogen-Activated Protein Kinase 3/metabolism , Molecular Sequence Data , Mutation , Phosphorylation , Promoter Regions, Genetic , Reverse Transcriptase Polymerase Chain Reaction , Transfection , Vesicular Glutamate Transport Protein 2/genetics , p38 Mitogen-Activated Protein Kinases/metabolism
14.
World J Gastroenterol ; 11(12): 1731-6, 2005 Mar 28.
Article in English | MEDLINE | ID: mdl-15793854

ABSTRACT

Glutamate is the major excitatory neurotransmitter in the mammalian central nervous system (CNS). Packaging and storage of glutamate into glutamatergic neuronal vesicles require ATP-dependent vesicular glutamate uptake systems, which utilize the electrochemical proton gradient as a driving force. Three vesicular glutamate transporters (VGLUT1-3) have been recently identified from neuronal tissue where they play a key role to maintain the vesicular glutamate level. Recently, it has been demonstrated that glutamate signaling is also functional in peripheral neuronal and non-neuronal tissues, and occurs in sites of pituitary, adrenal, pineal glands, bone, GI tract, pancreas, skin, and testis. The glutamate receptors and VGLUTs in digestive system have been found in both neuronal and endocrinal cells. The glutamate signaling in the digestive system may have significant relevance to diabetes and GI tract motility disorders. This review will focus on the most recent update of molecular physiology of digestive VGLUTs.


Subject(s)
Digestive System/metabolism , Membrane Transport Proteins/chemistry , Membrane Transport Proteins/metabolism , Amino Acid Transport Systems, Acidic/chemistry , Amino Acid Transport Systems, Acidic/metabolism , Animals , Humans , Protein Structure, Secondary , Vesicular Glutamate Transport Protein 1 , Vesicular Glutamate Transport Protein 2 , Vesicular Glutamate Transport Proteins
15.
Biochim Biophys Acta ; 1681(1): 53-8, 2004 Nov 24.
Article in English | MEDLINE | ID: mdl-15566944

ABSTRACT

We report the novel cloning and preliminary characterization of a human urate transporter (hURAT1) gene promoter. The transcription initiation site was mapped to a base 337 bp upstream of the ATG start codon by primer extension and 5'-RACE. The minimal functional promoter region is within 253 bp when the promoter/luciferase constructs were transfected into OK cells. The sex hormone testosterone significantly increases promoter activity, suggesting that hormonal regulation of hURAT1 is the root cause of observed differences in urate levels between males and females.


Subject(s)
Carrier Proteins/genetics , Organic Anion Transporters/genetics , Promoter Regions, Genetic/genetics , Transcription, Genetic , Base Sequence , Cloning, Molecular , Female , Gene Expression Regulation , Humans , Luciferases/metabolism , Male , Molecular Sequence Data , Organic Cation Transport Proteins , Plasmids , Sequence Deletion , Testosterone/pharmacology , Transcription Initiation Site
16.
Biochim Biophys Acta ; 1664(1): 38-44, 2004 Jul 01.
Article in English | MEDLINE | ID: mdl-15238256

ABSTRACT

The purpose of the present study was to determine the effect of angiotensin II (A-II) on membrane expression of Na+/H+ exchange isoforms NHE3 and NHE2 in the rat renal cortex. A-II (500 ng/kg per min) was chronically infused into the Sprague-Dawley rats by miniosmotic pump for 7 days. Arterial pressure and circulating plasma A-II level were significantly increased in A-II rats as compared to control rats. pH-dependent uptake of 22Na+ study in the presence of 50 microM HOE-694 revealed that Na+ uptake mediated by NHE3 was increased approximately 88% in the brush border membrane from renal cortex of A-II-treated rats. Western blotting showed that A-II increased NHE3 immunoreactive protein levels in the brush border membrane of the proximal tubules by 31%. Northern blotting revealed that A-II increased NHE3 mRNA abundance in the renal cortex by 42%. A-II treatment did not alter brush border NHE2 protein abundance in the renal proximal tubules. In conclusion, chronic A-II treatment increases NHE3-mediated Na+ uptake by stimulating NHE3 mRNA and protein content.


Subject(s)
Angiotensin II/metabolism , Sodium-Hydrogen Exchangers/metabolism , Animals , Blood Pressure , Blotting, Northern , Blotting, Western , Hydrogen-Ion Concentration , Kidney/metabolism , Kidney Cortex/metabolism , Male , Microvilli/metabolism , RNA/chemistry , RNA, Messenger/metabolism , Rats , Rats, Sprague-Dawley , Sodium/chemistry , Sodium/pharmacokinetics , Sodium-Hydrogen Exchanger 3 , Time Factors , Water/chemistry
17.
Pflugers Arch ; 447(5): 647-52, 2004 Feb.
Article in English | MEDLINE | ID: mdl-12759754

ABSTRACT

The SLC20 family transport proteins were originally identified as retroviral receptors (called Glvr-1 and Ram-1). Since then, they have been shown to function as sodium-phosphate (Na/P(i)) cotransporters, and have subsequently been classified as type III Na/P(i) cotransporters (now called Pit-1 and Pit-2). The Pit cotransporters share approximately 60% sequence homology, they have a high affinity for P(i), they are electrogenic with a coupling stoichiometry of >1 Na(+) per P(i) ion cotransported, and are inhibited by alkaline pH and phosphonoformic acid (PFA). Pit-1 and Pit-2 expression and/or activity has also been shown to be regulated by P(i) deprivation in some, but not all cells and tissues examined. The Pit-1 and Pit-2 cotransporters are widely expressed, but cell-type specific expression has only been investigated in bone, kidney and intestine. Both proteins are likely expressed on the basolateral membranes of polarized epithelial cells, where they are likely involved in cellular P(i) homeostasis. The Pit-1 and Pit-2 gene promoters have been cloned and characterized. While the exact roles of the Pit cotransporters in different cell types has not been definitively determined, they may be involved in important physiological pathways in bone, aortic smooth muscle cells, parathyroid glands, kidney and intestine.


Subject(s)
Phosphates/metabolism , Receptors, Virus/physiology , Sodium/metabolism , Symporters/physiology , Animals , Biological Transport/physiology , Humans , Multigene Family/physiology , Sodium-Phosphate Cotransporter Proteins , Sodium-Phosphate Cotransporter Proteins, Type III
18.
Am J Physiol Gastrointest Liver Physiol ; 284(5): G808-14, 2003 May.
Article in English | MEDLINE | ID: mdl-12444014

ABSTRACT

Glutamate has been suggested to play an important role in the release of insulin and glucagon from pancreatic cells via exocytosis. Vesicular glutamate transporter is a rate-limiting step for glutamate release and is involved in the glutamate-evoked exocytosis. Two vesicular glutamate transporters (VGLUT1 and -2) have recently been cloned from the brain. In this report, we first functionally characterized vesicular glutamate transporter in cultured pancreatic alpha- and beta-cells, and then detected mRNA expression of VGLUT1 and -2 in these cells. We also investigated the effect of high or low level of glucose on vesicular glutamate transport in cultured pancreas cells. Our results suggest that both alpha- and beta-cells contain functional vesicular glutamate transporter. The transport characteristics are similar to the cloned neuronal VGLUT1 and -2 in regard to ATP dependence, substrate specificity, kinetics, and chloride dependence. VGLUT2 mRNA is expressed in both alpha- and beta-cells, whereas VGLUT1 is only expressed in beta-cells. High (12.8 mM) and low (2.8 mM) concentrations of glucose increased vesicular glutamate transport in beta- and alpha-cells, respectively. VGLUT2 mRNA was significantly increased in beta- and alpha-cells by high and low glucose concentration, respectively. This increase in VGLUT2 mRNA was suppressed by actinomycin D. We conclude that both alpha- and beta-cells possess functional vesicular glutamate transporters regulated by alteration in glucose concentration, partly via the transcriptional mechanism.


Subject(s)
Carrier Proteins/metabolism , Glucose/pharmacology , Islets of Langerhans/cytology , Islets of Langerhans/metabolism , Membrane Transport Proteins , Vesicular Transport Proteins , Animals , Carrier Proteins/genetics , Cell Line , Cells, Cultured , Chlorides/pharmacology , Gene Expression Regulation/drug effects , Glucose/metabolism , Humans , Islets of Langerhans/drug effects , RNA, Messenger/genetics , RNA, Messenger/metabolism , Substrate Specificity , Time Factors , Vesicular Glutamate Transport Protein 1 , Vesicular Glutamate Transport Protein 2
19.
Am J Physiol Cell Physiol ; 282(3): C487-93, 2002 Mar.
Article in English | MEDLINE | ID: mdl-11832333

ABSTRACT

The current studies were designed to characterize type IIb sodium-inorganic phosphate (P(i)) cotransporter (NaP(i)-IIb) expression and to assess the effect of 1,25-(OH)(2) vitamin D(3) on NaP(i)-IIb gene expression during rat ontogeny. Sodium-dependent P(i) absorption by intestinal brush-border membrane vesicles (BBMVs) decreased with age, and NaP(i)-IIb gene expression also decreased proportionally with age. 1,25-(OH)(2) vitamin D(3) treatment increased intestinal BBMV P(i) absorption by approximately 2.5-fold in suckling rats and by approximately 2.1-fold in adult rats. 1,25-(OH)(2) vitamin D(3) treatment also increased NaP(i)-IIb mRNA abundance by approximately 2-fold in 14-day-old rats but had no effect on mRNA expression in adults. Furthermore, in rat intestinal epithelial (RIE) cells, 1,25-(OH)(2) vitamin D(3) increased NaP(i)-IIb mRNA abundance, an effect that was abolished by actinomycin D. Additionally, human NaP(i)-IIb gene promoter activity in transiently transfected RIE cells showed approximately 1.6-fold increase after 1,25-(OH)(2) vitamin D(3) treatment. In conclusion, we demonstrate that the age-related decrease in intestinal sodium-dependent P(i) absorption correlates with decreased NaP(i)-IIb mRNA expression. Our data also suggest that the effect of 1,25-(OH)(2) vitamin D(3) on NaP(i)-IIb expression is at least partially mediated by gene transcription in suckling rats.


Subject(s)
Aging/physiology , Calcitriol/pharmacology , Epithelial Cells/drug effects , Gene Expression Regulation/drug effects , Intestinal Mucosa/drug effects , Symporters/metabolism , Animals , Cell Line , Dactinomycin/pharmacology , Epithelial Cells/metabolism , Genes, Reporter , Humans , Intestinal Mucosa/cytology , Intestinal Mucosa/physiology , Nucleic Acid Synthesis Inhibitors/pharmacology , Promoter Regions, Genetic , RNA, Messenger/metabolism , Rats , Rats, Sprague-Dawley , Sodium-Phosphate Cotransporter Proteins , Sodium-Phosphate Cotransporter Proteins, Type IIb , Symporters/genetics
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