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1.
New Microbiol ; 47(1): 52-59, 2024 May.
Article in English | MEDLINE | ID: mdl-38700884

ABSTRACT

Monitoring Epstein-Barr virus (EBV) and cytomegalovirus (CMV) infection after transplantation is recommended to enable preemptive therapy. However, the most suitable sample type remains unclear. Patients who underwent hematopoietic stem cell or liver transplantation were included in this study. Viral loads in sequential whole-blood and plasma samples were retrospectively analyzed. EBV DNA was detected more frequently in whole blood (55%) than in plasma (18%). The detection rate of CMV DNA was similar between the two sample types. The correlation of viral loads between the two sample types were 0.515 and 0.688 for EBV and CMV, respectively. Among paired samples in which EBV DNA was detected in whole blood, the plasma EBV detection rate was significantly higher in patients who underwent hematopoietic stem cell transplantation than in those who underwent liver transplantation. The viral DNA load in whole blood and plasma showed similar trends. The EBV detection rate was higher in whole blood, and a high correlation was observed between CMV DNA loads and whole blood and plasma. These results indicate that whole blood is more sensitive for monitoring both EBV and CMV, whereas plasma is a potential alternative sample for monitoring CMV.


Subject(s)
Cytomegalovirus Infections , Cytomegalovirus , Epstein-Barr Virus Infections , Herpesvirus 4, Human , Viral Load , Humans , Cytomegalovirus/genetics , Cytomegalovirus/isolation & purification , Cytomegalovirus Infections/virology , Cytomegalovirus Infections/blood , Cytomegalovirus Infections/diagnosis , Herpesvirus 4, Human/genetics , Herpesvirus 4, Human/isolation & purification , Epstein-Barr Virus Infections/virology , Epstein-Barr Virus Infections/blood , Epstein-Barr Virus Infections/diagnosis , Male , Female , Middle Aged , Adult , Retrospective Studies , DNA, Viral/blood , Young Adult , Hematopoietic Stem Cell Transplantation , Aged , Plasma/virology , Liver Transplantation , Adolescent
2.
Article in English | MEDLINE | ID: mdl-38775453

ABSTRACT

OBJECTIVES: Chronic recurrent multifocal osteomyelitis (CRMO) is an autoinflammatory disease characterized by sterile bone inflammation; however, its pathophysiology is poorly understood. Thus, this study aimed to characterize the serum proteomic profiles of patients with CRMO to better understand the molecular mechanisms underpinning CRMO pathogenesis. METHODS: Proteomic profiling of the sera collected from 11 patients with CRMO (five patients were in active phase, six were in inactive phase) was conducted using liquid chromatography-mass spectrometry. Sera from four children without inflammatory diseases were used as controls. Pathway analysis was performed to identify the upregulated and downregulated proteins in patients with active CRMO. RESULTS: Compared with the control group, 19 and 41 proteins were upregulated and downregulated, respectively, in patients with active CRMO. Pathway and process enrichment analyses revealed that axon guidance was the most enriched category of upregulated proteins in patients with active CRMO, followed by neutrophil degranulation and mitogen-activated protein kinase cascade regulation. In comparison to patients with inactive CRMO, 36 proteins, including 11 keratin proteins, were upregulated and highly enriched in the intermediate filament organization category. Rho GTPase pathway-related proteins were downregulated in ibuprofen-treated patients. CONCLUSION: Proteomic analysis identified upregulated proteins in the sera of patients with acute CRMO. These proteins can be used as biomarkers for disease diagnosis and activity. Furthermore, we anticipate that this study will contribute to a deeper understanding of the pathophysiology of CRMO, which, in turn, will contribute to the discovery of potential novel therapeutic targets.

3.
Vaccine ; 42(11): 2927-2932, 2024 Apr 19.
Article in English | MEDLINE | ID: mdl-38548526

ABSTRACT

BACKGROUND: The introduction of varicella vaccines into routine pediatric immunization programs has led to a considerable reduction in varicella incidence. However, there have been reports of varicella, herpes zoster, and meningitis caused by the vaccine strain of varicella-zoster virus (VZV), raising concerns. Establishing the relationship between the wild-type and vaccine strains in VZV infections among previously vaccinated individuals is crucial. Differences in the single nucleotide polymorphisms (SNPs) among vaccine strains can be utilized to identify the strain. In this study, we employed nanopore sequencing to identify VZV strains and analyzed clinical samples. METHODS: We retrospectively examined vesicle and cerebrospinal fluid samples from patients with VZV infections. One sample each of the wild-type and vaccine strains, previously identified using allelic discrimination real-time PCR and direct sequencing, served as controls. Ten samples with undetermined VZV strains were included. After DNA extraction, a long PCR targeting the VZV ORF62 region was executed. Nanopore sequencing identified SNPs, allowing discrimination between the vaccine and wild-type strains. RESULTS: Nanopore sequencing confirmed SNPs at previously reported sites (105,705, 106,262, 107,136, and 107,252), aiding in distinguishing between wild-type and vaccine strains. Among the ten unknown samples, nine were characterized as wild strains and one as a vaccine strain. Even in samples with low VZV DNA levels, nanopore sequencing was effective in strain identification. CONCLUSION: This study validates that nanopore sequencing is a reliable method for differentiating between the wild-type and vaccine strains of VZV. Its ability to produce long-read sequences is remarkable, allowing simultaneous confirmation of known SNPs and the detection of new mutations. Nanopore sequencing can serve as a valuable tool for the swift and precise identification of wild-type and vaccine strains and has potential applications in future VZV surveillance.


Subject(s)
Chickenpox , Herpes Zoster , Nanopore Sequencing , Humans , Child , Herpesvirus 3, Human/genetics , Retrospective Studies , Polymorphism, Restriction Fragment Length , Polymerase Chain Reaction/methods , Chickenpox Vaccine/genetics , Herpes Zoster/prevention & control , DNA, Viral/genetics
4.
Mitochondrion ; 73: 84-94, 2023 11.
Article in English | MEDLINE | ID: mdl-37956777

ABSTRACT

The sleeping chironomid (Polypedilum vanderplanki) is the only insect capable of surviving complete desiccation in an ametabolic state called anhydrobiosis. Here, we focused on the role of oxidative stress and we observed the production of reactive oxygen species (ROS) in desiccating larvae and in those exposed to salinity stress. Oxidative stress occurs to some extent in desiccating larvae, inducing carbonylation of proteins. Oxidative stress overcomes the antioxidant defenses of the larvae during the first hour following rehydration of anhydrobiotic larvae. It facilitates the oxidation of DNA and cell membrane lipids; however, these damages are quickly repaired after a few hours. In addition to its deleterious effects, we demonstrated that artificial exposure to oxidative stress could induce a response similar to desiccation stress, at the transcriptome and protein levels. Furthermore, the response of anhydrobiosis-related genes to desiccation and salinity stress was inhibited by antioxidant treatment. Thus, we conclude that oxidative stress is an essential trigger for inducing the expression of protective genes during the onset of anhydrobiosis in desiccating of P. vanderplanki larvae.


Subject(s)
Chironomidae , Animals , Chironomidae/genetics , Chironomidae/metabolism , Desiccation , Antioxidants/metabolism , Oxidative Stress , Larva/genetics , Larva/metabolism
5.
J Pediatric Infect Dis Soc ; 12(10): 525-533, 2023 Oct 28.
Article in English | MEDLINE | ID: mdl-37738566

ABSTRACT

BACKGROUND: Congenital cytomegalovirus (cCMV) infection is a leading cause of nonhereditary neurological complications. When considering antiviral treatment, it is important to differentiate between symptomatic and asymptomatic patients. This study aimed to identify candidate plasma biomarkers for neurological complications of cCMV infection using proteomic analysis. METHODS: This study retrospectively enrolled five patients with symptomatic cCMV infection, four with asymptomatic cCMV infection with isolated sensorineural hearing loss (SNHL), and five with asymptomatic cCMV infection. The plasma samples were collected during neonatal period. The peptides were analyzed using liquid chromatography-mass spectrometry. The concentrations of differentially expressed proteins were validated using an enzyme-linked immunosorbent assay. RESULTS: A total of 456 proteins were identified and quantified. The levels of 80 proteins were significantly different between patients with and without cCMV-related symptoms including isolated SNHL. The levels of 31 proteins were significantly different between patients with and without neuroimaging abnormalities. The plasma concentrations of Fms-related receptor tyrosine kinase 4 in patients with cCMV-related symptoms were significantly higher than those in patients with asymptomatic cCMV infection. Moreover, plasma peptidylprolyl isomerase A levels were significantly higher in patients with neuroimaging abnormalities than in those without. CONCLUSIONS: Proteomic analysis of patients with cCMV infection showed that Fms-related receptor tyrosine kinase 4 and peptidylprolyl isomerase A could be novel diagnostic biomarkers for neurological complications of cCMV infection.


Subject(s)
Cytomegalovirus Infections , Hearing Loss, Sensorineural , Infant, Newborn , Humans , Infant , Cytomegalovirus , Retrospective Studies , Proteomics , Cytomegalovirus Infections/congenital , Hearing Loss, Sensorineural/diagnosis , Hearing Loss, Sensorineural/etiology , Biomarkers , Peptidylprolyl Isomerase , Protein-Tyrosine Kinases
7.
Radiat Res ; 198(5): 475-487, 2022 11 01.
Article in English | MEDLINE | ID: mdl-36048240

ABSTRACT

Lung is one of the high-risk organs for radiation-induced carcinogenesis, but the risk of secondary lung-cancer development after particle-beam therapy and the underlying mechanism(s) remain to be elucidated. To investigate the effects of particle-beam radiation on adjacent normal tissues during cancer therapy, 7-week-old male and female B6C3F1 mice were irradiated with 0.2-4 Gy of gamma rays (for comparison), carbon ions (290 MeV/u, linear energy transfer 13 keV/µm), or fast neutrons (0.05-1 Gy, mean energy, ∼2 MeV), and lung-tumor development was assessed by histopathology. Mice irradiated with ≥2 Gy of carbon ions or ≥0.2 Gy of neutrons developed lung adenocarcinoma (AC) significantly sooner than did non-irradiated mice. The relative biological effectiveness values for carbon ions for lung AC development were 1.07 for male mice and 2.59 for females, and the corresponding values for neutrons were 4.63 and 4.57. Genomic analysis of lung ACs revealed alterations in genes involved in Egfr signaling. Hyperphosphorylation of Erk and a frequent nuclear abnormality (i.e., nuclear groove) were observed in lung ACs of mice irradiated with carbon ions or neutrons compared with ACs from non-irradiated or gamma-ray-irradiated groups. Our data indicate that the induction of lung AC by carbon ions occurred at a rate similar to that for gamma rays in males and approximately 2-to 3-fold greater than that for gamma rays in females. In contrast, the effect of neutrons on lung AC development was approximately 4- to 5-fold greater than that of gamma rays. Our results provide valuable information concerning risk assessment of radiation-induced lung tumors after particle-beam therapy and increase our understanding of the molecular basis of tumor development.


Subject(s)
Lung Neoplasms , Neoplasms, Radiation-Induced , Male , Female , Mice , Animals , Gamma Rays/adverse effects , Carbon/adverse effects , Relative Biological Effectiveness , Neutrons , Fast Neutrons , Neoplasms, Radiation-Induced/genetics , Neoplasms, Radiation-Induced/pathology , Lung Neoplasms/etiology , Ions , Lung/pathology , Dose-Response Relationship, Radiation
8.
Biomed Opt Express ; 12(2): 1036-1049, 2021 Feb 01.
Article in English | MEDLINE | ID: mdl-33680558

ABSTRACT

Spectrally encoded endoscopy (SEE) is an ultra-miniature endoscopy technology that encodes each spatial location on the sample with a different wavelength. One challenge in SEE is achieving color imaging with a small probe. We present a novel SEE probe that is capable of conducting real-time RGB imaging using three diffraction orders (6th order diffraction of the blue spectrum, 5th of green, and 4th of red). The probe was comprised of rotating 0.5 mm-diameter illumination optics inside a static, 1.2 mm-diameter flexible sheath with a rigid distal length of 5 mm containing detection fibers. A color chart, resolution target, and swine tissue were imaged. The device achieved 44k/59k/23k effective pixels per R/G/B channels over a 58° angular field and differentiated a wide gamut of colors.

9.
Radiat Res ; 187(2): 210-220, 2017 02.
Article in English | MEDLINE | ID: mdl-28135125

ABSTRACT

Epidemiology studies have shown that children are at greater overall risk of radiation-induced cancer, but the modifying effect of age at exposure in different tissues is heterogeneous. Early epidemiology findings of increased lung cancer risk with increasing age at the time of exposure have been dismissed, with suggestions that the trend is an artefact from a failure to adequately correct for the effects of tobacco smoking. Yet, differing models used in subsequent analyses have shown that the increased susceptibility with age, counter to the overall solid tumor trend, can either be confirmed or discounted depending on the model parameters used. In this study, we analyzed the induction of tumors in female Wistar rats exposed to increasing thoracic doses of X-ray as neonates, juveniles or young adults, to allow the effect of age at exposure in this early period to be observed in the absence of any interactions with smoking. Histology was used to compare tumor subtypes among groups, and genomic DNA copy number alterations in a number of tumors arising after irradiation at different ages were examined. Induction of lung cancers increased with radiation dose, with the frequency of early occurring lung adenomas greater in rats irradiated at older ages. At the highest dose, the rats irradiated at 5 or 15 weeks of age showed increased age-specific rates of lung adenocarcinomas in later life compared to those irradiated at 1 week of age. However, thoracic mammary gland tumors induced by the highest dose at the later ages significantly decreased the lifespan in these groups, reducing the number of rats at risk of radiation-induced lung adenocarcinoma. There was no induction of mammary tumors outside of the irradiated field. Lung adenocarcinomas showed widespread DNA copy number aberrations at the chromosome level, but the only recurrent lesions were intragenic Fhit deletions and losses on chromosome 4. The results presented here suggest that the risk of radiation-induced lung cancer after irradiation may not monotonically decrease with age, and demonstrate that increasing lung cancer risk with exposure age can be observed independent of corrections for smoking, and that mammary tumors may show a similar relationship with age.


Subject(s)
Aging/radiation effects , Lung Neoplasms/etiology , Mammary Neoplasms, Experimental/etiology , Neoplasms, Radiation-Induced/etiology , Thorax/radiation effects , Animals , DNA Copy Number Variations/radiation effects , Female , Incidence , Lung Neoplasms/genetics , Mammary Neoplasms, Experimental/genetics , Neoplasms, Radiation-Induced/genetics , Rats , Rats, Wistar , X-Rays/adverse effects
10.
Toxicol Appl Pharmacol ; 267(3): 266-75, 2013 Mar 15.
Article in English | MEDLINE | ID: mdl-23337358

ABSTRACT

Assessment of risks associated with childhood exposure to ionizing radiation when combined with chemical carcinogens is of great importance. We studied the age-dependence of the effect of combined exposure to ionizing radiation (IR) and a chemical carcinogen on lung carcinogenesis. Female 1-, 5-, and 22-week-old Wistar rats were locally irradiated on the thorax with X-rays (3.18 Gy) and/or were injected intraperitoneally with N-nitrosobis(2-hydroxypropyl)amine (BHP) (1g/kg body weight) 1 week after X-ray exposure or at 23 weeks of age. Rats were terminated at 90 weeks of age. We found that: (i) the incidence of lung tumors (adenoma and adenocarcinoma) increased slightly as a function of age at X-ray exposure, although this was not statistically significant, while the incidence induced by BHP decreased with increasing age at administration; (ii) combined exposure to X-rays at 5 or 22 weeks with BHP 1 week later enhanced the tumor incidence, and the effect at early-life stage (5 weeks irradiation) was more effective than that at late-life stage (22 weeks irradiation); (iii) combined exposure preferentially enhanced malignant transformation; (iv) although a longer interval between the X-ray and BHP treatments reduced the combined effect, risks of early-life irradiation at 1 or 5 weeks of age lasted into adulthood; (v) adenomas and adenocarcinomas induced by X-ray and/or BHP originated from surfactant apoprotein A-positive alveolar type II cells; and (vi), extracellular signal-regulated kinase pathway activation was observed in half the adenocarcinomas, regardless of the exposure schedule. In conclusion, combined exposure may enhance lung tumorigenesis more synergistically at early-life stage (5 weeks of age) than later-life stage.


Subject(s)
Carcinogens/toxicity , Cell Transformation, Neoplastic/drug effects , Cell Transformation, Neoplastic/radiation effects , Lung Neoplasms/chemically induced , Neoplasms, Radiation-Induced/chemically induced , Nitrosamines/toxicity , Thorax/drug effects , Thorax/radiation effects , Adenocarcinoma/chemically induced , Adenocarcinoma/etiology , Adenocarcinoma/pathology , Adenoma/chemically induced , Adenoma/etiology , Aging/drug effects , Aging/radiation effects , Animals , Animals, Newborn , Cell Transformation, Neoplastic/pathology , Female , Lung Neoplasms/etiology , Lung Neoplasms/pathology , Neoplasms, Radiation-Induced/pathology , Rats , Rats, Wistar , Thorax/pathology
11.
FEBS J ; 277(20): 4215-28, 2010 Oct.
Article in English | MEDLINE | ID: mdl-20825482

ABSTRACT

Larvae of an anhydrobiotic insect, Polypedilum vanderplanki, accumulate very large amounts of trehalose as a compatible solute on desiccation, but the molecular mechanisms underlying this accumulation are unclear. We therefore isolated the genes coding for trehalose metabolism enzymes, i.e. trehalose-6-phosphate synthase (TPS) and trehalose-6-phosphate phosphatase (TPP) for the synthesis step, and trehalase (TREH) for the degradation step. Although computational prediction indicated that the alternative splicing variants (PvTpsα/ß) obtained encoded probable functional motifs consisting of a typical consensus domain of TPS and a conserved sequence of TPP, PvTpsα did not exert activity as TPP, but only as TPS. Instead, a distinct gene (PvTpp) obtained expressed TPP activity. Previous reports have suggested that insect TPS is, exceptionally, a bifunctional enzyme governing both TPS and TPP. In this article, we propose that TPS and TPP activities in insects can be attributed to discrete genes. The translated product of the TREH ortholog (PvTreh) certainly degraded trehalose to glucose. Trehalose was synthesized abundantly, consistent with increased activities of TPS and TPP and suppressed TREH activity. These results show that trehalose accumulation observed during anhydrobiosis induction in desiccating larvae can be attributed to the activation of the trehalose synthetic pathway and to the depression of trehalose hydrolysis.


Subject(s)
Chironomidae/enzymology , Dehydration/enzymology , Sleep/physiology , Trehalase/metabolism , Animals , Chironomidae/physiology , Dehydration/genetics , Glucosyltransferases/genetics , Hydrolysis , Larva/physiology , Metabolic Networks and Pathways/genetics , Molecular Sequence Data , Phosphoric Monoester Hydrolases/genetics , Trehalase/genetics
12.
Cryobiology ; 60(2): 138-46, 2010 Apr.
Article in English | MEDLINE | ID: mdl-19850023

ABSTRACT

Dry-preservation of nucleated cells from multicellular animals represents a significant challenge in life science. As anhydrobionts can tolerate a desiccated state, their cells and organs are expected to show high desiccation tolerance in vitro. In the present study, we established cell lines derived from embryonic tissues of an anhydrobiotic chironomid, Polypedilum vanderplanki, designated as Pv11 and Pv210. Salinity stress induced the expression of a set of anhydrobiosis-related genes in both Pv11 and Pv210 cells, suggesting that at least a part of cells can autonomously control the physiological changes for the entry into anhydrobiosis. When desiccated with medium supplemented with 300 mM trehalose or sucrose and stored for 4 weeks in dry air (approximately 5% relative humidity), a small percentage of the cells was found to be viable upon rehydration, although surviving cells seemed not to be able to multiply. We also attempted dry-preservation of organs isolated from P. vanderplanki larvae, and found that a proportion of cells in some organs, including fat body, testis, nerve and dorsal vessel, tolerated in vitro desiccation.


Subject(s)
Chironomidae/cytology , Desiccation/methods , Preservation, Biological/methods , Animals , Base Sequence , Cell Line , Cell Survival , Chironomidae/embryology , Chironomidae/genetics , DNA Primers/genetics , Female , Gene Expression , Genes, Insect , Humans , Larva/anatomy & histology , Male , Organ Preservation/methods , Osmotic Pressure , Salinity , Stress, Physiological
13.
Zoolog Sci ; 26(3): 238-42, 2009 Mar.
Article in English | MEDLINE | ID: mdl-19341346

ABSTRACT

High hydrostatic pressure (HHP) can induce physical changes in DNA, proteins, and lipids, causing lethal or sublethal damage to organisms. However, HHP tolerance of animals has not been studied sufficiently. In this study, HHP tolerance of four species of invertebrate anhydrobiotes (the tardigrade Milnesium tardigradum, a nematode species in the family Plectidae, larvae of Polypedilum vanderplanki, and cysts of Artemia franciscana), which have the potential to enter anhydrobiosis upon desiccation, were investigated by exposing them to 1.2 GPa for 20 minutes. This exposure killed the anhydrobiotes in their ordinary hydrated state, but did not affect their survival in the anhydrobiotic state. The results indicated that the hydrated anhydrobiotes were vulnerable to HHP, but that HHP of 1.2 GPa was not sufficient to kill them in anhyrdobiosis.


Subject(s)
Hydrostatic Pressure , Invertebrates/physiology , Animals , Dehydration
14.
J Insect Physiol ; 54(8): 1220-5, 2008 Aug.
Article in English | MEDLINE | ID: mdl-18652833

ABSTRACT

Strategies to combat desiccation are critical for organisms living in arid and semi-arid areas. Larvae of the Australian chironomid Paraborniella tonnoiri resist desiccation by reducing water loss. In contrast, larvae of the African species Polypedilum vanderplanki can withstand almost complete dehydration, referred to as anhydrobiosis. For successful anhydrobiosis, the dehydration rate of P. vanderplanki larvae has to be controlled. Here, we desiccated larvae by exposing them to different drying regimes, each progressing from high to low relative humidity, and examined survival after rehydration. In larvae of P. vanderplanki, reactions following desiccation can be categorized as follows: (I) no recovery at all (direct death), (II) dying by unrepairable damages after rehydration (delayed death), and (III) full recovery (successful anhydrobiosis). Initial conditions of desiccation severely affected survival following rehydration, i.e. P. vanderplanki preferred 100% relative humidity where body water content decreased slightly. In subsequent conditions, unfavorable dehydration rate, such as more than 0.7 mg water lost per day, resulted in markedly decreased survival rate of rehydrated larvae. Slow dehydration may be required for the synthesis and distribution of essential molecules for anhydrobiosis. Larvae desiccated at or above maximum tolerable rates sometimes showed temporary recovery but died soon after.


Subject(s)
Chironomidae/physiology , Larva/physiology , Animals , Survival , Water/metabolism
15.
Biochem Biophys Res Commun ; 367(4): 834-9, 2008 Mar 21.
Article in English | MEDLINE | ID: mdl-18201556

ABSTRACT

The use of transgenic avian allows cost effective and safe production of pharmaceutical proteins. Here, we report the successful production of chimeric chickens expressing human erythropoietin (hEpo) using a high-titer retroviral vector. The hEpo expressed by transgenic hens accumulated abundantly in egg white and had N- and O-linked carbohydrates. While attachment of terminal sialic acid and galactose was incomplete, portions of N- and O-linked carbohydrates were present. In vitro biological activity of egg white-hEpo was comparable to that produced by recombinant CHO cells.


Subject(s)
Animals, Genetically Modified/metabolism , Chickens/physiology , Egg Proteins/biosynthesis , Erythropoietin/metabolism , Protein Engineering/methods , Recombinant Proteins/metabolism , Animals , Egg Proteins/genetics , Erythropoietin/genetics
16.
Proc Natl Acad Sci U S A ; 104(28): 11585-90, 2007 Jul 10.
Article in English | MEDLINE | ID: mdl-17606922

ABSTRACT

Trehalose is potentially a useful cryo- or anhydroprotectant molecule for cells and biomolecules such as proteins and nucleotides. A major obstacle to application is that cellular membranes are impermeable to trehalose. In this study, we isolated and characterized the functions of a facilitated trehalose transporter [trehalose transporter 1 (TRET1)] from an anhydrobiotic insect, Polypedilum vanderplanki. Tret1 cDNA encodes a 504-aa protein with 12 predicted transmembrane structures. Tret1 expression was induced by either desiccation or salinity stress. Expression was predominant in the fat body and occurred concomitantly with the accumulation of trehalose, indicating that TRET1 is involved in transporting trehalose synthesized in the fat body into the hemolymph. Functional expression of TRET1 in Xenopus oocytes showed that transport activity was stereochemically specific for trehalose and independent of extracellular pH (between 4.0 and 9.0) and electrochemical membrane potential. These results indicate that TRET1 is a trehalose-specific facilitated transporter and that the direction of transport is reversible depending on the concentration gradient of trehalose. The extraordinarily high values for apparent Km (>or=100 mM) and Vmax (>or=500 pmol/min per oocyte) for trehalose both indicate that TRET1 is a high-capacity transporter of trehalose. Furthermore, TRET1 was found to function in mammalian cells, suggesting that it confers trehalose permeability on cells, including those of vertebrates as well as insects. These characteristic features imply that TRET1 in combination with trehalose has high potential for basic and practical applications in vivo.


Subject(s)
Carrier Proteins/physiology , Chironomidae/chemistry , Chironomidae/metabolism , Trehalose/metabolism , Animals , Biological Transport, Active/physiology , CHO Cells , Cell Line, Tumor , Cell Membrane Permeability/physiology , Chironomidae/physiology , Cricetinae , Cricetulus , Humans , Mice , Molecular Sequence Data , NIH 3T3 Cells
17.
J Insect Physiol ; 52(11-12): 1189-93, 2006.
Article in English | MEDLINE | ID: mdl-17056058

ABSTRACT

Embryonic diapause is commonly terminated by exposure to low temperature for a certain duration. Previous studies using the silkworm, Bombyx mori, showed that extracellular signal-regulated kinase (ERK), a member of the mitogen-activated protein kinase family, was activated by cold exposure and regulated diapause termination. The involvement of ERK in regulation of diapause termination was investigated in the false melon beetle, Atrachya menetriesi. Embryonic diapause of this beetle is terminated both by cold exposure and by mercury. Phospho-ERK levels remained high during the pre-diapause period but decreased after the eggs entered diapause. Exposure to 7.5 degrees C, which was effective for diapause termination, increased phospho-ERK levels, and these levels were maintained under 7.5 degrees C at least for 100 d. Incubation at 25 degrees C after the eggs were kept at 7.5 degrees C for 20 d, which intensified diapause, decreased the phospho-ERK level. An insufficient cold treatment, i.e., incubation at 0 degrees C for diapause termination did not activate ERK. However, incubation at 0 degrees C after cold treatment at 7.5 degrees C, which is effective for diapause termination, induced high phospho-ERK levels. Moreover, mercury treatment also increased phospho-ERK. Therefore, changes in the phospho-ERK level correlated well with diapause intensity. The results suggest that ERK plays a key role in the regulation of embryonic diapause.


Subject(s)
Coleoptera/embryology , Coleoptera/enzymology , Embryonic Development/genetics , Extracellular Signal-Regulated MAP Kinases/physiology , Temperature , Animals , Antibodies/metabolism , Embryo, Nonmammalian/drug effects , Embryo, Nonmammalian/physiology , Embryonic Development/drug effects , Embryonic Development/physiology , Extracellular Signal-Regulated MAP Kinases/analysis , Extracellular Signal-Regulated MAP Kinases/immunology , Gene Expression Regulation, Developmental , Mercuric Chloride/pharmacology , Time Factors
18.
Biochem Biophys Res Commun ; 348(1): 56-61, 2006 Sep 15.
Article in English | MEDLINE | ID: mdl-16875677

ABSTRACT

Late embryogenesis abundant (LEA) proteins are associated with desiccation tolerance in anhydrobiotic organisms. The larvae of an African chironomid, Polypedilum vanderplanki, are able to withstand almost complete desiccation during which they enter a state of suspended animation. Here, we developed an EST database from desiccating larvae and isolated three cDNAs encoding proteins (PvLEA1, PvLEA2, and PvLEA3) with highly significant matches to Group 3 LEA proteins. Both mRNA and protein levels of all three examples were increased by dehydration stress imposed by either desiccation or hypersalinity, and one protein, PvLEA2, is likely to be post-translationally processed into smaller molecules. This first description of LEA protein genes in arthropods suggests that this protein family is widespread throughout invertebrate phyla, and that animals, plants, and microorganisms possess similar mechanisms for combating dehydration stress.


Subject(s)
Chironomidae/genetics , Databases, Genetic , Gene Expression Regulation, Developmental , Insect Proteins/genetics , Animals , Chironomidae/growth & development , Cloning, Molecular , Dehydration/genetics , Larva/genetics , Molecular Sequence Data
19.
J Insect Physiol ; 52(6): 569-75, 2006 Jun.
Article in English | MEDLINE | ID: mdl-16546206

ABSTRACT

The eggs of the silkworm Bombyx mori undergo a state of suspended overt development and diminished metabolism called "diapause" to escape adverse environmental conditions. Termination of Bombyx embryonic diapause requires 2-3 months of low temperature (5 degrees C), but the molecular mechanisms underlying diapause termination are unknown. Diapause termination requires a decrease in the sorbitol concentration, which arrests embryonic development, and the secretion factors from yolk cells that promote embryonic development. In the present study, we report that 20-hydroxyecdysone promoted the development of denuded embryos and that ecdysteroid-phosphate phosphatase (EPPase), which is a key enzyme for active ecdysteroid production, was induced by incubation of diapausing eggs at 5 degrees C. In dechorionated egg cultures, extracellular signal-regulated kinase (ERK), which is activated by incubating diapausing eggs at 5 degrees C, regulated sorbitol-glycogen conversion, ecdysteroid secretion via gene transcription of key enzymes, sorbitol dehydrogenase-2, and EPPase, suggesting that ERK has a key role in diapause termination.


Subject(s)
Bombyx/embryology , Ecdysteroids/metabolism , Embryonic Development/physiology , Extracellular Signal-Regulated MAP Kinases/physiology , Sorbitol/metabolism , Animals , Bombyx/metabolism , Bombyx/physiology , Cold Temperature , Ecdysteroids/physiology , Ecdysterone/physiology , Egg Yolk/physiology , Female , Gene Expression , Glycogen/biosynthesis , Phosphoric Monoester Hydrolases/metabolism
20.
J Insect Physiol ; 52(5): 473-9, 2006 May.
Article in English | MEDLINE | ID: mdl-16499923

ABSTRACT

To understand the hormonal control of embryonic diapause, juvenile hormone analogs (JHAs), methoprene and hydroprene, and 20-hydroxyecdysone (20E) were applied onto diapause eggs of Locusta migratoria and Oxya yezoensis. These insects enter diapause at the mid-stage of embryogenesis prior to blastokinesis. Topical application of JHAs significantly facilitated diapause termination in both species but JHA-treated embryos underwent abnormal morphogenesis, pigmentation and sclerotization without dorsal closure. The Locusta eggs immersed in the 20E solution for 24h terminated diapause in a dose-dependent manner. We also investigated phosphorylation of extracellular signal-regulated kinase (ERK), a member of mitogen-activated protein kinase (MAPK), during diapause-terminating process of Locusta migratoria and found that ERK was activated either by cold exposure or JHA treatment. The possible involvement of the hormones and ERK in embryonic diapause and the possibility of ecdysteroids synthesis by prothoracic glands of diapause embryo were proposed.


Subject(s)
Ecdysterone/physiology , Extracellular Signal-Regulated MAP Kinases/physiology , Juvenile Hormones/physiology , Locusta migratoria/growth & development , Ovum/growth & development , Animals , Cold Temperature , Grasshoppers/growth & development , Phosphorylation
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