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1.
J Med Internet Res ; 23(4): e27060, 2021 04 19.
Article in English | MEDLINE | ID: mdl-33764883

ABSTRACT

BACKGROUND: The number of deaths from COVID-19 continues to surge worldwide. In particular, if a patient's condition is sufficiently severe to require invasive ventilation, it is more likely to lead to death than to recovery. OBJECTIVE: The goal of our study was to analyze the factors related to COVID-19 severity in patients and to develop an artificial intelligence (AI) model to predict the severity of COVID-19 at an early stage. METHODS: We developed an AI model that predicts severity based on data from 5601 COVID-19 patients from all national and regional hospitals across South Korea as of April 2020. The clinical severity of COVID-19 was divided into two categories: low and high severity. The condition of patients in the low-severity group corresponded to no limit of activity, oxygen support with nasal prong or facial mask, and noninvasive ventilation. The condition of patients in the high-severity group corresponded to invasive ventilation, multi-organ failure with extracorporeal membrane oxygenation required, and death. For the AI model input, we used 37 variables from the medical records, including basic patient information, a physical index, initial examination findings, clinical findings, comorbid diseases, and general blood test results at an early stage. Feature importance analysis was performed with AdaBoost, random forest, and eXtreme Gradient Boosting (XGBoost); the AI model for predicting COVID-19 severity among patients was developed with a 5-layer deep neural network (DNN) with the 20 most important features, which were selected based on ranked feature importance analysis of 37 features from the comprehensive data set. The selection procedure was performed using sensitivity, specificity, accuracy, balanced accuracy, and area under the curve (AUC). RESULTS: We found that age was the most important factor for predicting disease severity, followed by lymphocyte level, platelet count, and shortness of breath or dyspnea. Our proposed 5-layer DNN with the 20 most important features provided high sensitivity (90.2%), specificity (90.4%), accuracy (90.4%), balanced accuracy (90.3%), and AUC (0.96). CONCLUSIONS: Our proposed AI model with the selected features was able to predict the severity of COVID-19 accurately. We also made a web application so that anyone can access the model. We believe that sharing the AI model with the public will be helpful in validating and improving its performance.


Subject(s)
Artificial Intelligence , COVID-19/epidemiology , Adolescent , Adult , Aged , Aged, 80 and over , COVID-19/mortality , Child , Child, Preschool , Female , Humans , Infant , Infant, Newborn , Male , Middle Aged , Models, Statistical , Mortality , Republic of Korea/epidemiology , Research Design , Retrospective Studies , Risk Factors , SARS-CoV-2 , Young Adult
2.
Int J Mol Sci ; 19(11)2018 Nov 13.
Article in English | MEDLINE | ID: mdl-30428563

ABSTRACT

Lymphatic filariasis and onchocerciasis caused by filarial nematodes are important diseases leading to considerable morbidity throughout tropical countries. Diethylcarbamazine (DEC), albendazole (ALB), and ivermectin (IVM) used in massive drug administration are not highly effective in killing the long-lived adult worms, and there is demand for the development of novel macrofilaricidal drugs affecting new molecular targets. A Ca2+ binding protein, calumenin, was identified as a novel and nematode-specific drug target for filariasis, due to its involvement in fertility and cuticle development in nematodes. As sterilizing and killing effects of the adult worms are considered to be ideal profiles of new drugs, calumenin could be an eligible drug target. Indeed, the Caenorhabditis elegans mutant model of calumenin exhibited enhanced drug acceptability to both microfilaricidal drugs (ALB and IVM) even at the adult stage, proving the roles of the nematode cuticle in efficient drug entry. Molecular modeling revealed that structural features of calumenin were only conserved among nematodes (C. elegans, Brugia malayi, and Onchocerca volvulus). Structural conservation and the specificity of nematode calumenins enabled the development of drugs with good target selectivity between parasites and human hosts. Structure-based virtual screening resulted in the discovery of itraconazole (ITC), an inhibitor of sterol biosynthesis, as a nematode calumenin-targeting ligand. The inhibitory potential of ITC was tested using a nematode mutant model of calumenin.


Subject(s)
Antinematodal Agents/chemistry , Antinematodal Agents/pharmacology , Drug Discovery , Albendazole/chemistry , Albendazole/pharmacology , Albendazole/therapeutic use , Amino Acid Sequence , Animals , Antinematodal Agents/therapeutic use , Caenorhabditis elegans/drug effects , Caenorhabditis elegans/metabolism , Caenorhabditis elegans Proteins/chemistry , Caenorhabditis elegans Proteins/metabolism , Calcium-Binding Proteins/chemistry , Calcium-Binding Proteins/metabolism , Diethylcarbamazine/chemistry , Diethylcarbamazine/pharmacology , Diethylcarbamazine/therapeutic use , Drug Evaluation, Preclinical , Filariasis/drug therapy , Itraconazole/chemistry , Itraconazole/pharmacology , Itraconazole/therapeutic use , Ivermectin/chemistry , Ivermectin/pharmacology , Ivermectin/therapeutic use , Models, Molecular , Quantitative Structure-Activity Relationship
3.
Exp Parasitol ; 143: 24-9, 2014 Aug.
Article in English | MEDLINE | ID: mdl-24830752

ABSTRACT

Since pyrimethamine, the general therapeutic drug for toxoplasmosis, presents several adverse side effects, the need to develop and evaluate new drugs for the condition is critical. In this study, anti-Toxoplasma gondii activities of 3-[{2-((E)-furan-2-ylmethylene)hydrazinyl}methylene]-1,3-dihydroindol-2-one (ATT-5126) and 6-trifluoromethyl-2-thiouracil (KH-0562) were evaluated in vitro using a 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assay and in vivo by measuring amount of the tachyzoites in mice ascites. Biochemical parameters such as lipid peroxidation (LPO), glutathione (GSH), alanine aminotransferase (ALT), and aspartate aminotransferase (AST) were also evaluated in livers of mice at 4 days post-infection. As a result, the ATT-5126 and KH-0562 showed anti-T. gondii activity in vitro. Treatment of ATT-5126 or KH-0562 decreased the amount of tachyzoites in T. gondii infected ICR mice. The relative weight of liver and spleen increased by T. gondii infection were decreased by treatment of ATT-5126 or KH-0562. The levels of LPO, ALT and AST, which are biochemical parameters involved in liver injury, were also significantly recovered by treatment of ATT-5126 or KH-0562 (p<0.05). In particular, the recovered levels by KH-0562 were similar to those of pyrimethamine-treated group (p<0.05). However, the level of GSH, which is an antioxidant indicator, showed insignificant statistics. The results suggest that KH-0562 show anti-T. gondii activities in vitro and in vivo with low hepatotoxicity. Therefore, KH-0562 may be a useful candidate for treating T. gondii infection.


Subject(s)
Coccidiostats/pharmacology , Liver/drug effects , Thiouracil/analogs & derivatives , Toxoplasma/drug effects , Toxoplasmosis/drug therapy , Alanine Transaminase/blood , Alanine Transaminase/drug effects , Animals , Aspartate Aminotransferases/blood , Aspartate Aminotransferases/drug effects , Coccidiostats/therapeutic use , Female , Glutathione/drug effects , Glutathione/metabolism , HeLa Cells , Humans , Lipid Peroxidation/drug effects , Liver/metabolism , Liver/pathology , Mice , Mice, Inbred ICR , Organ Size/drug effects , Spleen/drug effects , Spleen/pathology , Thiouracil/pharmacology , Thiouracil/therapeutic use
4.
Malar J ; 12: 47, 2013 Feb 04.
Article in English | MEDLINE | ID: mdl-23374507

ABSTRACT

BACKGROUND: With the increasing resistance of malaria parasites to available drugs, there is an urgent demand to develop new anti-malarial drugs. Calpain inhibitor, ALLN, is proposed to inhibit parasite proliferation by suppressing haemoglobin degradation. This provides Plasmodium calpain as a potential target for drug development. Pf-calpain, a cysteine protease of Plasmodium falciparum, belongs to calpain-7 family, which is an atypical calpain not harboring Ca2+-binding regulatory motifs. In this present study, in order to establish the screening system for Pf-calpain specific inhibitors, the active form of Pf-calpain was first identified. METHODS: Recombinant Pf-calpain including catalytic subdomain IIa (rPfcal-IIa) was heterologously expressed and purified. Enzymatic activity was determined by both fluorogenic substrate assay and gelatin zymography. Molecular homology modeling was carried out to address the activation mode of Pf-calpain in the aspect of structural moiety. RESULTS: Based on the measurement of enzymatic activity and protease inhibitor assay, it was found that the active form of Pf-calpain only contains the catalytic subdomain IIa, suggesting that Pf-calpain may function as a monomeric form. The sequence prediction indicates that the catalytic subdomain IIa contains all amino acid residues necessary for catalytic triad (Cys-His-Asn) formation. Molecular modeling suggests that the Pf-calpain subdomain IIa makes an active site, holding the catalytic triad residues in their appropriate orientation for catalysis. The mutation analysis further supports that those amino acid residues are functional and have enzymatic activity. CONCLUSION: The identified active form of Pf-calpain could be utilized to establish high-throughput screening system for Pf-calpain inhibitors. Due to its unique monomeric structural property, Pf-calpain could be served as a novel anti-malarial drug target, which has a high specificity for malaria parasite. In addition, the monomeric form of enzyme may contribute to relatively simple synthesis of selective inhibitors.


Subject(s)
Antimalarials/pharmacology , Calpain/antagonists & inhibitors , Drug Evaluation, Preclinical/methods , High-Throughput Screening Assays/methods , Plasmodium falciparum/drug effects , Plasmodium falciparum/enzymology , Amino Acid Sequence , Antimalarials/isolation & purification , Calpain/genetics , Calpain/isolation & purification , Models, Molecular , Molecular Sequence Data , Protein Conformation , Recombinant Proteins/antagonists & inhibitors , Recombinant Proteins/genetics , Recombinant Proteins/isolation & purification , Sequence Homology, Amino Acid
5.
Bioorg Med Chem Lett ; 23(5): 1293-6, 2013 Mar 01.
Article in English | MEDLINE | ID: mdl-23357632

ABSTRACT

Malaria is the most common of the parasitic diseases in tropical and subtropical regions. Adverse side effects of anti-malarial drugs have precluded them as a potential clinical drug. In this study, novel derivatives of N-acetyl-L-leucyl-L-leucyl-L-norleucinal (ALLN) based on a variety of dipeptidyl α,ß-unsaturated amides containing lysine as a part were synthesized and evaluated. Lower toxicity was achieved by reducing or eliminating the tendency of forming chemically reactive and toxic intermediates and metabolites. The synthesized compounds were evaluated for anti-malarial efficacy against Plasmodium falciparum and cytotoxicity in human epitheloid carcinoma cervix (HeLa cells) by estimating the therapeutic index (TI). N-Methyl amide with N'-Boc protection among them exhibited strong anti-malarial activity and N-methyl amide with N'-m-methylbenzyl amide showed excellent anti-malarial activity with much lower toxicity than the ALLN. Therefore, the two chemicals, as well as the underlying design rationale, could be useful in the discovery and development of new anti-malarial drugs.


Subject(s)
Antimalarials/chemistry , Antimalarials/pharmacology , Leupeptins/chemistry , Leupeptins/pharmacology , Plasmodium falciparum/drug effects , Amides/chemistry , Amides/pharmacology , Dipeptides/chemistry , Dipeptides/pharmacology , HeLa Cells , Humans , Leupeptins/chemical synthesis , Plasmodium falciparum/growth & development
6.
Biology (Basel) ; 12(3)2023 Mar 17.
Article in English | MEDLINE | ID: mdl-36979156

ABSTRACT

Caenorhabditis elegans can adapt and survive in dynamically changing environments by the smart and delicate switching of molecular plasticity. C. elegans dauer diapause is a form of phenotypic and developmental plasticity that induces reversible developmental arrest upon environmental cues. An ER (endoplasmic reticulum)-resident Ca2+ binding protein, calumenin has been reported to function in a variety of malignant diseases in vertebrates and in the process of muscle contraction-relaxation. In C. elegans, CALU-1 is known to function in Ca2+-regulated behaviors (pharyngeal pumping and defecation) and cuticle formation. The cuticles of dauer larvae are morphologically distinct from those of larvae that develop in favorable conditions. The structure of the dauer cuticle is thicker and more highly reinforced than that of other larval stages to protect dauer larvae from various environmental insults. Since the calu-1(tm1783) mutant exhibited abnormal cuticle structures such as highly deformed annuli and alae, we investigated whether CALU-1 is involved in dauer formation or not. Ascaroside pheromone (ascr#2) and crude daumone were used under starvation conditions to analyze the rate of dauer formation in the calu-1(tm1783) mutant. Surprisingly, the dauer ratio of the calu-1(tm1783) mutant was extremely low compared to that of the wild type. In fact, the calu-1(tm1783) mutants were mostly unable to enter diapause. We also found that calu-1 is expressed in body-wall muscle and AIA interneurons at the dauer stage. Taken together, our results suggest that CALU-1 is required for normal entry into diapause in C. elegans.

7.
Parasitol Res ; 111(4): 1645-50, 2012 Oct.
Article in English | MEDLINE | ID: mdl-22740294

ABSTRACT

Malaria is a worldwide infectious disease. There are many diagnostic kits to detect malaria infection. However, the sensitivity of these diagnostic kits remains a problem. To develop a diagnostic kit for malaria that has high sensitivity, it is necessary to produce monoclonal antibodies (McAbs) with high affinity. The present study was undertaken to produce hybridoma cells that can be used to generate McAbs with high affinity and specificity against Plasmodium vivax lactate dehydrogenase (pvLDH). In this study, BALB/c mice were immunized with purified recombinant polypeptides that encode pvLDH. McAbs against pvLDH were produced according to the protocol of hybridoma technique using myeloma cells (SP2/0 cell lines). The McAbs were characterized by isotyping and by Western blot analysis. Two McAbs (D2H and D7E) against pvLDH antigen were obtained. The isotypes of D2H and D7E were IgG2b. They recognize 33 kDa proteins that were defined as pvLDH by Western blot analysis. In the affinity test, D2H and D7E showed positively optical density value until each McAbs were serially diluted at concentrations of 0.156 and 0.078 µg/ml, respectively. To evaluate sensitivity and specificity against clinical specimens of P. vivax, purified McAbs were tested with alkaline phosphatase-conjugated monoclonal antibodies and blood samples (n = 180) of P. vivax patients using the sandwich enzyme-linked immunosorbent assay, showing the 98% sensitivity. We suggest that McAbs produced in this study may be used for developing efficient and rapid diagnostic kits.


Subject(s)
Antibodies, Monoclonal , Antibodies, Protozoan , Antigens, Protozoan/blood , Clinical Laboratory Techniques/methods , L-Lactate Dehydrogenase/blood , Malaria, Vivax/diagnosis , Plasmodium vivax/immunology , Animals , Antibodies, Monoclonal/isolation & purification , Antibodies, Protozoan/isolation & purification , Antigens, Protozoan/immunology , Enzyme-Linked Immunosorbent Assay/methods , Female , Humans , L-Lactate Dehydrogenase/immunology , Mass Screening/methods , Mice , Mice, Inbred BALB C , Parasitology/methods , Plasmodium vivax/enzymology , Sensitivity and Specificity
8.
Int J Mol Sci ; 13(9): 11912-11922, 2012.
Article in English | MEDLINE | ID: mdl-23109891

ABSTRACT

Many phytochemicals have been recognized to have potential therapeutic efficacy in cancer treatment. In this study, we investigated ethyl gallate (EG) for possible proapoptotic effects in the human promyelocytic leukemia cell line, HL-60. We examined cell viability, morphological changes, DNA content and fragmentation, and expression of apoptosis-related proteins for up to 48 h after EG treatment. The results showed that EG induced morphological changes and DNA fragmentation and reduced HL-60 cell viability in a dose-dependent and time-dependent manner. Western blotting analysis indicated that EG-mediated HL-60 apoptosis mainly occurred through the mitochondrial pathway, as shown by the release of cytochrome c, apoptosis-inducing factor (AIF), and endonuclease G (Endo G), as well as the upregulation of Bcl-2-associated X protein (Bax). EG also activated the death receptor-dependent pathway of apoptosis by enhancing the expression of caspases-8, -9, and -3 and the Bcl-2 interacting domain (Bid). Collectively, our results showed that EG induces apoptosis in HL-60 via mitochondrial-mediated pathways.


Subject(s)
Apoptosis/drug effects , BH3 Interacting Domain Death Agonist Protein/biosynthesis , Caspase 3/biosynthesis , Caspase 8/biosynthesis , Caspase 9/biosynthesis , Endodeoxyribonucleases/biosynthesis , Gallic Acid/analogs & derivatives , Gene Expression Regulation/drug effects , Dose-Response Relationship, Drug , Gallic Acid/pharmacology , HL-60 Cells , Humans , bcl-2-Associated X Protein/biosynthesis
9.
Metabolites ; 12(11)2022 Nov 17.
Article in English | MEDLINE | ID: mdl-36422268

ABSTRACT

BAM15 was recently screened as a protonophore uncoupler specifically for the mitochondrial membrane but not the plasma membrane. It is equally as potent as FCCP, but less toxic. Previously, mitochondrial uncoupling via DNP alleviates neurodegeneration in the nematode Caenorhabditis elegans during aging. Therefore, we investigated whether BAM15 uncouplers could phenotypically and functionally reduce neuronal defects in aged nematodes. We observed green fluorescence protein-tagged mechanosensory neurons and performed touch and chemotaxis assays during aging. Wild-type animals treated with both 50 µM BAM15 and 10 µM DNP showed reduced mechanosensory neuronal defects during aging, which correlates with the maintenance of touch responses and short-term memory during aging. Uncoupler mutant ucp-4 also responded the same way as the wild-type, reducing neurodegeneration in 50 µM BAM15 and 10 µM DNP-treated animals compared to the DMSO control. These results suggest that 50 µM BAM15 alleviates neurodegeneration phenotypically and functionally in C. elegans during aging, potentially through mitochondrial uncoupling. In accordance with the preserved neuronal shape and function in aged C. elegans, 50 µM BAM15 extended the mean lifespan of both wild-type and ucp-4 mutants.

10.
Korean J Parasitol ; 49(4): 431-6, 2011 Dec.
Article in English | MEDLINE | ID: mdl-22355214

ABSTRACT

The onset, severity, and ultimate outcome of malaria infection are influenced by parasite-expressed virulence factors as well as by individual host responses to these determinants. In both humans and mice, liver injury follows parasite entry, persisting to the erythrocytic stage in the case of infection with the fatal strain of Plasmodium falciparum. Hepatic nuclear factor (HNF)-1α is a master regulator of not only the liver damage and adaptive responses but also diverse metabolic functions. In this study, we analyzed the expression of host HNF-1α in relation to malaria infection and evaluated its interaction with the 5'-untranslated region of subtilisin-like protease 2 (subtilase, Sub2). Recombinant human HNF-1α expressed by a lentiviral vector (LV HNF-1α) was introduced into mice. Interestingly, differences in the activity of the 5'-untranslated region of the Pf-Sub2 promoter were detected in 293T cells, and LV HNF-1α was observed to influence promoter activity, suggesting that host HNF-1α interacts with the Sub2 gene.


Subject(s)
5' Untranslated Regions/genetics , Gene Expression Regulation/genetics , Hepatocyte Nuclear Factor 1-alpha/metabolism , Malaria, Falciparum/parasitology , Plasmodium falciparum/genetics , Subtilisins/genetics , Animals , Cell Line , DNA, Protozoan/genetics , Genetic Vectors , Hepatocyte Nuclear Factor 1-alpha/administration & dosage , Hepatocyte Nuclear Factor 1-alpha/genetics , Host-Parasite Interactions , Humans , Injections, Intravenous , Lentivirus/genetics , Malaria, Falciparum/metabolism , Malaria, Falciparum/pathology , Mice , Plasmodium falciparum/drug effects , Promoter Regions, Genetic/genetics , RNA, Messenger/genetics , RNA, Protozoan/genetics , Recombinant Proteins , Signal Transduction , Subtilisins/metabolism
11.
Food Sci Nutr ; 8(12): 6633-6642, 2020 Dec.
Article in English | MEDLINE | ID: mdl-33312547

ABSTRACT

Dietary supplementation of flavonoids has been shown to reduce the severity of neurodegenerative disorders such as dementia, Parkinson's disease, and Alzheimer's disease by their antioxidant effects. However, their low bioavailabilityin vivo raises the question of how much their antioxidant capacity actually contributes to the mitigating effects. The physicochemical properties of flavonoids suggest they could function as mitochondrial uncouplers. Moreover, mitochondrial uncoupling alleviated neurodegeneration in Caenorhabditis elegans during aging in previous research. Therefore, we investigated whether various flavonoids (fisetin, quercetin, apigenin, chrysin, catechin, and naringenin) could reduce neuronal defects by mitochondrial uncoupling in C. elegans. Both neuronal defects and mitochondrial membrane potential were reduced in aged worms in nearly all of the flavonoid treatments suggesting that flavonoids may reduce neurodegeneration in C. elegans. However, there was no significant reduction of neuronal defects in mitophagy-deficient pink-1/pdr-1 double mutants under flavonoid treatments. These results suggest that flavonoids could function as mitochondrial uncouplers to mitigate neurodegeneration in aged C. elegans, possibly via a PINK1/Parkin mitophagy process.

12.
Biochem Biophys Res Commun ; 390(1): 136-41, 2009 Dec 04.
Article in English | MEDLINE | ID: mdl-19785996

ABSTRACT

Nramp1 (natural resistance-associated macrophage protein-1) is a functionally conserved iron-manganese transporter in macrophages. Manganese (Mn), a superoxide scavenger, is required in trace amounts and functions as a cofactor for most antioxidants. Three Nramp homologs, smf-1, smf-2, and smf-3, have been identified thus far in the nematode Caenorhabditis elegans. A GFP promoter assay revealed largely intestinal expression of the smf genes from early embryonic through adult stages. In addition, smf deletion mutants showed increased sensitivity to excess Mn and mild sensitivity to EDTA. Interestingly, these smf deletion mutants demonstrated hypersensitivity to the pathogen Staphylococcus aureus, an effect that was rescued by Mn feeding or knockdown of the Golgi calcium/manganese ATPase, pmr-1, indicating that Mn uptake is essential for the innate immune system. This reversal of pathogen sensitivity by Mn feeding suggests a protective and therapeutic role of Mn in pathogen evasion systems. We propose that the C. elegans intestinal lumen may mimic the mammalian macrophage phagosome and thus could be a simple model for studying Mn-mediated innate immunity.


Subject(s)
Caenorhabditis elegans/metabolism , Cation Transport Proteins/metabolism , Intestinal Mucosa/metabolism , Manganese/metabolism , Animals , Caenorhabditis elegans/genetics , Caenorhabditis elegans/microbiology , Caenorhabditis elegans Proteins/genetics , Caenorhabditis elegans Proteins/metabolism , Calcium-Transporting ATPases/genetics , Calcium-Transporting ATPases/metabolism , Cation Transport Proteins/genetics , Edetic Acid/pharmacology , Gene Knockdown Techniques , Immunity, Innate , Staphylococcus aureus
13.
Mol Cells ; 25(4): 566-71, 2008 Jun 30.
Article in English | MEDLINE | ID: mdl-18460897

ABSTRACT

Calcineurin (Cn) is a calcium/calmodulin-dependent serine/threonine protein phosphatase that has diverse functions in different cell types and organisms. We screened proteins interacting with the C. elegans CnA homolog, TAX-6, by the yeast two-hybrid system. CNP-3 (Calcineurin interacting protein-3) is a novel protein that physically interacts with the catalytic domain of TAX-6. It is strongly expressed in the nuclei of intestine, hypodermis, dorsal uterine regions and spermatheca. Expression begins around the 60-cell stage and proceeds during all larval stages and the adult. To elucidate the biological function of cnp-3 we isolated a cnp-3 deletion mutant. Since CNP-3 binds CnA, we looked at factors associated with calcineurin loss-of-function mutants, such as brood size, body size, serotonin- and levamisole-mediated egg-laying behavior. The cnp-3(jh145) single mutant had no gross defects compared to wild-type animal. However, the phenotypes of the double mutants, tax-6(p675);cnp-3(jh145) and cnb-1(jh103);cnp-3(jh145), were more severe in terms of brood size, body size and serotonin-mediated egg-laying defects than tax-6(p675) and cnb-1(jh103), respectively. These results suggest that dysfunction of cnp-3 enhances certain calcineurin loss-of-function phenotypes in C. elegans.


Subject(s)
Caenorhabditis elegans Proteins/metabolism , Calcineurin/metabolism , Carrier Proteins/metabolism , Animals , Caenorhabditis elegans , Caenorhabditis elegans Proteins/genetics , Calcineurin/genetics , Calmodulin/metabolism , Carrier Proteins/genetics , Cloning, Molecular , Organisms, Genetically Modified/genetics , Organisms, Genetically Modified/metabolism , Protein Binding/genetics , Sequence Deletion , Signal Transduction/genetics , Two-Hybrid System Techniques
14.
Mol Cells ; 40(11): 864-870, 2017 Nov 30.
Article in English | MEDLINE | ID: mdl-29081084

ABSTRACT

The uncoupling protein 4 (ucp-4) gene is involved in age-dependent neurodegeneration in C. elegans. Therefore, we aimed to investigate the mechanism underlying the association between mitochondrial uncoupling and neurodegeneration by examining the effects of uncoupling agents and ucp-4 overexpression in C. elegans. Treatment with either DNP or CCCP improved neuronal defects in wild type during aging. Uncoupling agents also restored neuronal phenotypes of ucp-4 mutants to those exhibited by wild type, while ucp-4 overexpression attenuated the severity of age-dependent neurodegeneration. Neuronal improvements were further associated with reductions in mitochondrial membrane potentials. However, these age-dependent neuroprotective effects were limited in mitophagy-deficient mutant, pink-1, background. These results suggest that membrane uncoupling can attenuate age-dependent neurodegeneration by stimulating mitophagy.


Subject(s)
2,4-Dinitrophenol/pharmacology , Aging/genetics , Caenorhabditis elegans Proteins/genetics , Mitochondrial Uncoupling Proteins/genetics , Neurodegenerative Diseases/etiology , Organophosphonates/pharmacology , Piperazines/pharmacology , 2,4-Dinitrophenol/therapeutic use , Animals , Caenorhabditis elegans , Caenorhabditis elegans Proteins/metabolism , Disease Models, Animal , Membrane Potential, Mitochondrial/drug effects , Mitochondria/drug effects , Mitochondria/physiology , Mitochondrial Uncoupling Proteins/metabolism , Mitophagy/drug effects , Mutation , Neurodegenerative Diseases/drug therapy , Neurodegenerative Diseases/genetics , Organophosphonates/therapeutic use , Piperazines/therapeutic use
15.
FEBS Lett ; 580(13): 3161-6, 2006 May 29.
Article in English | MEDLINE | ID: mdl-16684534

ABSTRACT

Vacuolar H+-ATPase (V-ATPase) is an ATP-dependent proton pump, which transports protons across the membrane. It is a multi-protein complex which is composed of at least 13 subunits. The Caenorhabditis elegans vha-8 encodes the E subunit of V-ATPase which is expressed in the hypodermis, intestine and H-shaped excretory cells. VHA-8 is necessary for proper intestinal function likely through its role in cellular acidification of intestinal cells. The null mutants of vha-8 show a larval lethal phenotype indicating that vha-8 is an essential gene for larval development in C. elegans. Interestingly, characteristics of necrotic cell death were observed in the hypodermis and intestine of the arrested larvae suggesting that pH homeostasis via the E subunit of V-ATPase is required for the cell survival in C. elegans.


Subject(s)
Caenorhabditis elegans Proteins/physiology , Caenorhabditis elegans/growth & development , Genes, Lethal , Vacuolar Proton-Translocating ATPases/genetics , Vacuolar Proton-Translocating ATPases/physiology , Amino Acid Sequence , Animals , Apoptosis/genetics , Caenorhabditis elegans/enzymology , Caenorhabditis elegans/genetics , Caenorhabditis elegans Proteins/analysis , Caenorhabditis elegans Proteins/genetics , Gene Deletion , Homeostasis , Intestines/enzymology , Larva/enzymology , Molecular Sequence Data , Protein Subunits/analysis , Protein Subunits/genetics , Protein Subunits/physiology , Vacuolar Proton-Translocating ATPases/analysis
16.
J Mol Biol ; 352(2): 313-8, 2005 Sep 16.
Article in English | MEDLINE | ID: mdl-16084527

ABSTRACT

The enteric muscle contraction (EMC) is the last step of the defecation behavior which occurs every 50 s in Caenorhabditis elegans. This EMC is regulated by intestinal and anal depressor muscles, which are innervated by GABA motor neurons. Our data show that calcineurin (tax-6) is expressed in intestinal muscle and anal depressor muscle, and the gain-of-function mutant of calcineurin, tax-6(jh107), shows defects in enteric muscle contractions. In addition, the intracellular region of EXP-1, an excitatory GABA receptor, specifically binds to calcineurin A. This interaction between TAX-6 and EXP-1 appears to be independent of both calcium and CNB, which is the calcium-binding regulatory subunit. Genetic evidence of epistasis between cnb-1(jh103) and exp-1(sa6) suggests that calcineurin functions as a negative regulator of excitatory GABA receptor in GABA signaling in C.elegans.


Subject(s)
Caenorhabditis elegans Proteins/physiology , Caenorhabditis elegans/physiology , Calcineurin/physiology , Receptors, GABA/physiology , Amino Acid Sequence , Animals , Caenorhabditis elegans/genetics , Caenorhabditis elegans Proteins/genetics , Digestive System/innervation , Digestive System Physiological Phenomena , Molecular Sequence Data , Motor Neurons/physiology , Muscle Contraction/physiology , Muscle, Smooth/innervation , Muscle, Smooth/physiology , Mutation , Receptors, GABA/genetics , Signal Transduction
17.
Int J Biol Sci ; 12(7): 824-35, 2016.
Article in English | MEDLINE | ID: mdl-27313496

ABSTRACT

Rapid diagnostic tests (RDTs) can detect anti-malaria antibodies in human blood. As they can detect parasite infection at the low parasite density, they are useful in endemic areas where light infection and/or re-infection of parasites are common. Thus, malaria antibody tests can be used for screening bloods in blood banks to prevent transfusion-transmitted malaria (TTM), an emerging problem in malaria endemic areas. However, only a few malaria antibody tests are available in the microwell-based assay format and these are not suitable for field application. A novel malaria antibody (Ab)-based RDT using a differential diagnostic marker for falciparum and vivax malaria was developed as a suitable high-throughput assay that is sensitive and practical for blood screening. The marker, merozoite surface protein 1 (MSP1) was discovered by generation of a Plasmodium-specific network and the hierarchical organization of modularity in the network. Clinical evaluation revealed that the novel Malaria Pf/Pv Ab RDT shows improved sensitivity (98%) and specificity (99.7%) compared with the performance of a commercial kit, SD BioLine Malaria P.f/P.v (95.1% sensitivity and 99.1% specificity). The novel Malaria Pf/Pv Ab RDT has potential for use as a cost-effective blood-screening tool for malaria and in turn, reduces TTM risk in endemic areas.


Subject(s)
Diagnostic Tests, Routine/methods , Malaria/diagnosis , Antigens, Protozoan/immunology , Malaria/metabolism , Malaria/transmission , Malaria, Falciparum/diagnosis , Malaria, Falciparum/metabolism , Malaria, Falciparum/transmission , Malaria, Vivax/diagnosis , Malaria, Vivax/metabolism , Malaria, Vivax/transmission , Merozoite Surface Protein 1/metabolism , Transfusion Reaction
18.
J Mol Biol ; 344(2): 585-95, 2004 Nov 19.
Article in English | MEDLINE | ID: mdl-15522306

ABSTRACT

Ca(2+)/calmodulin-dependent calcineurin has been shown to have important roles in various Ca(2+) signaling pathways. We have previously reported that cnb-1(jh103) mutants, null mutants of a regulatory B subunit, displayed pleiotropic defects including uncoordinated movement and delayed egg laying in Caenorhabditis elegans. Interestingly, gain-of-function mutants of a catalytic A subunit showed exactly opposite phenotypes to those of cnb-1(null) mutants providing an excellent genetic model to define calcium-mediated signaling pathway at the organism level. Furthermore, calcineurin is also important for normal cuticle formation, which is required for maintenance of normal body size in C.elegans. Genetic interactions between tax-6 and several mutants including egl-30 and egl-10, which are known to be involved in G-protein signaling pathways suggest that calcineurin indeed regulates locomotion and serotonin-mediated egg laying through goa-1(Goalpha) and egl-30(Gqalpha). Our results indicate that, along with CaMKII, calcineurin regulates G-protein-coupled phosphorylation signaling pathways in C.elegans.


Subject(s)
Caenorhabditis elegans/metabolism , Calcineurin/genetics , Calcineurin/metabolism , Calcium-Calmodulin-Dependent Protein Kinases/metabolism , GTP-Binding Proteins/metabolism , Gene Expression Regulation, Developmental , Oviposition/genetics , Animals , Body Size/genetics , Caenorhabditis elegans/drug effects , Caenorhabditis elegans/ultrastructure , Caenorhabditis elegans Proteins , Calcium-Calmodulin-Dependent Protein Kinase Type 2 , Female , Gene Deletion , Green Fluorescent Proteins/metabolism , Locomotion/genetics , Models, Genetic , Phosphorylation , Recombinant Fusion Proteins/metabolism , Reverse Transcriptase Polymerase Chain Reaction , Serotonin/pharmacology , Signal Transduction , Two-Hybrid System Techniques
19.
Mol Cells ; 19(1): 149-54, 2005 Feb 28.
Article in English | MEDLINE | ID: mdl-15750353

ABSTRACT

Cyclic nucleotide-gated (CNG) channels encoded by the tax-4 and tax-2 genes are required for chemosensing and thermosensing in the nematode C. elegans. We identified a gene in the C. elegans genome, which we designated cng-1, that is highly homologous to tax-4. Partial CNG-1 protein tagged with green fluorescent protein was expressed in several sensory neurons of the amphid. We created a deletion mutant of cng-1, cng-1 (jh111), to investigate its in vivo function. The mutant worms had no detectable abnormalities in terms of their basic behavior or morphology. Whereas tax-4 and tax-2 mutants failed to respond to water-soluble or volatile chemical attractants, the cng-1 null mutant exhibited normal chemotaxis to such chemicals and a tax-4;cng-1 double mutant had a similar phenotype to tax-4 single mutants. Interestingly, cng-1 and tax-4 had a synergistic effect on brood size.


Subject(s)
Caenorhabditis elegans Proteins/isolation & purification , Caenorhabditis elegans/genetics , Ion Channels/isolation & purification , Amino Acid Sequence , Animals , Base Sequence , Caenorhabditis elegans/physiology , Caenorhabditis elegans Proteins/genetics , Caenorhabditis elegans Proteins/physiology , Chemotaxis/genetics , Gene Deletion , Ion Channels/genetics , Ion Channels/physiology , Molecular Sequence Data , Mutation , Neurons/metabolism , Odorants , Reproduction
20.
Diagn Microbiol Infect Dis ; 82(2): 128-34, 2015 Jun.
Article in English | MEDLINE | ID: mdl-25824725

ABSTRACT

Early diagnosis of dengue virus (DENV) is important. There are numerous products on the market claiming to detect DENV NS1, but these are not always reliable. In this study, a highly sensitive and accurate rapid diagnostic test (RDT) was developed using anti-dengue NS1 monoclonal antibodies. A recombinant NS1 protein was produced with high antigenicity and purity. Monoclonal antibodies were raised against this purified NS1 antigen. The RDT was constructed using a capturing (4A6A10, Kd=7.512±0.419×10(-9)) and a conjugating antibody (3E12E6, Kd=7.032±0.322×10(-9)). The diagnostic performance was evaluated with NS1-positive clinical samples collected from various dengue endemic countries and compared to SD BioLine Dengue NS1 Ag kit. The constructed RDT exhibited higher sensitivity (92.9%) with more obvious diagnostic performance than the commercial kit (83.3%). The specificity of constructed RDT was 100%. The constructed RDT could offer a reliable point-of-care testing tool for the early detection of dengue infections in remote areas and contribute to the control of dengue-related diseases.


Subject(s)
Dengue/diagnosis , Immunoassay/methods , Point-of-Care Systems , Viral Nonstructural Proteins/blood , Antibodies, Monoclonal/immunology , Antibodies, Monoclonal/isolation & purification , Antibodies, Viral/immunology , Antibodies, Viral/isolation & purification , Early Diagnosis , Humans , Sensitivity and Specificity , Time Factors
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