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1.
bioRxiv ; 2024 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-38645036

RESUMO

Polyamines are polycationic molecules that are crucial in a wide array of cellular functions. Their biosynthesis is mediated by aminopropyl transferases (APTs), promising targets in antimicrobial, antineoplastic and antineurodegenerative therapies. A major limitation, however, is the lack of high-throughput assays to measure their activity. We developed the first fluorescence-based assay, DAB-APT, for measurement of APT activity using 1,2-diacetyl benzene, which forms fluorescent conjugates with putrescine, spermidine and spermine with fluorescence intensity increasing with increasing carbon chain length. The assay has been validated using APT enzymes from S. cerevisiae and P. falciparum and is suitable for high-throughput screening of large chemical libraries. Given the importance of APTs in infectious diseases, cancer and neurobiology, our DAB-APT assay has broad applications, holding promise for advancing research and drug discovery efforts.

2.
medRxiv ; 2024 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-38585766

RESUMO

Human babesiosis is a rapidly emerging and potentially fatal tick-borne disease caused by intraerythrocytic apicomplexan parasites of the Babesia genus. Among the various species of Babesia that infect humans, B. duncani has been found to cause severe and life-threatening infections. Detection of active B. duncani infection is critical for accurate diagnosis and effective management of the disease. While molecular assays for the detection of B. duncani infection in blood are available, a reliable strategy to detect biomarkers of active infection has not yet been developed. Here, we report the development of the first B. duncani antigen capture assays that rely on the detection of two B. duncani -exported immunodominant antigens, BdV234 and BdV38. The assays were validated using blood samples from cultured parasites in human erythrocytes and B. duncani -infected laboratory mice at different parasitemia levels and following therapy. The assays display high specificity with no cross-reactivity with B. microti , B. divergens , Babesia MO1, or P. falciparum. The assay also demonstrates high sensitivity, detecting as low as 115 infected erythrocytes/µl of blood. Screening of 1,731 blood samples from diverse biorepositories, including previously identified Lyme and/or B. microti positive human samples and new specimens from field mice, showed no evidence of B. duncani infection in these samples. The assays could be useful in diverse diagnostic scenarios, including point-of-care testing for early B. duncani infection detection in patients, field tests for screening reservoir hosts, and high-throughput screening such as blood collected for transfusion. Short summary: We developed two ELISA-based assays, BdACA38 and BdACA234, for detecting B. duncani , a potentially fatal tick-borne parasite causing human babesiosis. The assays target two immunodominant antigens, BdV234 and BdV38, demonstrating high specificity (no cross-reactivity with other Babesia species or Plasmodium falciparum ) and sensitivity (detecting as low as 115 infected erythrocytes/µl). The assays were validated using in vitro-cultured parasites and infected mice. Screening diverse blood samples showed no evidence of B. duncani active infection among 1,731 human and field mice blood samples collected from the north-eastern, midwestern, and western US. These assays offer potential in diverse diagnostic scenarios, including early patient detection, reservoir animal screening, and transfusion-transmitted babesiosis prevention.

3.
Cell Commun Signal ; 22(1): 190, 2024 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-38521953

RESUMO

BACKGROUND: Solid tumors promote tumor malignancy through interaction with the tumor microenvironment, resulting in difficulties in tumor treatment. Therefore, it is necessary to understand the communication between cells in the tumor and the surrounding microenvironment. Our previous study revealed the cancer malignancy mechanism of Bcl-w overexpressed in solid tumors, but no study was conducted on its relationship with immune cells in the tumor microenvironment. In this study, we sought to discover key factors in exosomes secreted from tumors overexpressing Bcl-w and analyze the interaction with the surrounding tumor microenvironment to identify the causes of tumor malignancy. METHODS: To analyze factors affecting the tumor microenvironment, a miRNA array was performed using exosomes derived from cancer cells overexpressing Bcl-w. The discovered miRNA, miR-6794-5p, was overexpressed and the tumorigenicity mechanism was confirmed using qRT-PCR, Western blot, invasion, wound healing, and sphere formation ability analysis. In addition, luciferase activity and Ago2-RNA immunoprecipitation assays were used to study the mechanism between miR-6794-5p and its target gene SOCS1. To confirm the interaction between macrophages and tumor-derived miR-6794-5p, co-culture was performed using conditioned media. Additionally, immunohistochemical (IHC) staining and flow cytometry were performed to analyze macrophages in the tumor tissues of experimental animals. RESULTS: MiR-6794-5p, which is highly expressed in exosomes secreted from Bcl-w-overexpressing cells, was selected, and it was shown that the overexpression of miR-6794-5p increased migratory ability, invasiveness, and stemness maintenance by suppressing the expression of the tumor suppressor SOCS1. Additionally, tumor-derived miR-6794-5p was delivered to THP-1-derived macrophages and induced M2 polarization by activating the JAK1/STAT3 pathway. Moreover, IL-10 secreted from M2 macrophages increased tumorigenicity by creating an immunosuppressive environment. The in vitro results were reconfirmed by confirming an increase in M2 macrophages and a decrease in M1 macrophages and CD8+ T cells when overexpressing miR-6794-5p in an animal model. CONCLUSIONS: In this study, we identified changes in the tumor microenvironment caused by miR-6794-5p. Our study indicates that tumor-derived miR-6794-5p promotes tumor aggressiveness by inducing an immunosuppressive environment through interaction with macrophage.


Assuntos
Exossomos , MicroRNAs , Neoplasias , Animais , Neoplasias/genética , Bioensaio , Transporte Biológico , Linfócitos T CD8-Positivos , MicroRNAs/genética , Microambiente Tumoral
4.
Nat Microbiol ; 9(4): 905-921, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38528146

RESUMO

Some viruses are rarely transmitted orally or sexually despite their presence in saliva, breast milk, or semen. We previously identified that extracellular vesicles (EVs) in semen and saliva inhibit Zika virus infection. However, the antiviral spectrum and underlying mechanism remained unclear. Here we applied lipidomics and flow cytometry to show that these EVs expose phosphatidylserine (PS). By blocking PS receptors, targeted by Zika virus in the process of apoptotic mimicry, they interfere with viral attachment and entry. Consequently, physiological concentrations of EVs applied in vitro efficiently inhibited infection by apoptotic mimicry dengue, West Nile, Chikungunya, Ebola and vesicular stomatitis viruses, but not severe acute respiratory syndrome coronavirus 2, human immunodeficiency virus 1, hepatitis C virus and herpesviruses that use other entry receptors. Our results identify the role of PS-rich EVs in body fluids in innate defence against infection via viral apoptotic mimicries, explaining why these viruses are primarily transmitted via PS-EV-deficient blood or blood-ingesting arthropods rather than direct human-to-human contact.


Assuntos
Líquidos Corporais , Vesículas Extracelulares , Vírus , Infecção por Zika virus , Zika virus , Feminino , Humanos , Fosfatidilserinas , Ligação Viral
5.
Noncoding RNA Res ; 9(1): 33-43, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38075199

RESUMO

High-dose radiation (HDR) is widely used for cancer treatment, but the effectiveness of low-dose radiation (LDR) in the treatment of various diseases is controversial. Therefore, to safely utilize LDR for therapeutic purposes, further research on its numerous biological effects of LDR is required. Interest in the increased use of medical imaging devices or the effects of surrounding living environmental radiation on the human body, particularly on fibrosis, is rapidly increasing. Therefore, this study aimed to verify the relationship between LDR and pulmonary fibrosis by evaluating the changes in fibroblasts after LDR treatment and their associated signaling mechanisms. LDR increased the expression of fibrosis markers COL1A1 and α-SMA, cell proliferation, and migration by activating YAP1 and Twist in fibroblasts. Meanwhile, miRNA was employed as a tool to inhibit LDR-induced fibrosis and it was found that miR-765 simultaneously targeted COL1A1, α-SMA, and YAP1. At the cellular level, miR-765 reduced the proliferation and migration of fibroblasts by suppressing the expression of LDR-induced fibrosis factors COL1A1, α-SMA, and YAP1. The efficacy of miR-765 in vivo was confirmed using bleomycin (BLM)-induced fibrotic mouse model. The characteristics of pulmonary fibrosis were reduced after injection of miR-765-overexpressing cells into BLM-induced fibrotic mice. In addition, the suppression of miR-765 expression in the plasma of patients with pulmonary fibrosis confirmed the negative relationship between pulmonary fibrosis and miR-765 expression. Therefore, this study demonstrates that miR-765 is a potential novel diagnostic biomarker and major target for the development of therapeutic agents to inhibit pulmonary fibrosis.

6.
J Biol Chem ; 299(11): 105313, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37797695

RESUMO

Effective and safe therapies for the treatment of diseases caused by intraerythrocytic parasites are impeded by the rapid emergence of drug resistance and the lack of novel drug targets. One such disease is human babesiosis, which is a rapidly emerging tick-borne illness caused by Babesia parasites. In this study, we identified fosinopril, a phosphonate-containing, FDA-approved angiotensin converting enzyme (ACE) inhibitor commonly used as a prodrug for hypertension and heart failure, as a potent inhibitor of Babesia duncani parasite development within human erythrocytes. Cell biological and mass spectrometry analyses revealed that the conversion of fosinopril to its active diacid molecule, fosinoprilat, is essential for its antiparasitic activity. We show that this conversion is mediated by a parasite-encoded esterase, BdFE1, which is highly conserved among apicomplexan parasites. Parasites carrying the L238H mutation in the active site of BdFE1 failed to convert the prodrug to its active moiety and became resistant to the drug. Our data set the stage for the development of this class of drugs for the therapy of vector-borne parasitic diseases.


Assuntos
Babesia , Parasitos , Pró-Fármacos , Animais , Humanos , Inibidores da Enzima Conversora de Angiotensina/farmacologia , Fosinopril/farmacologia , Pró-Fármacos/farmacologia , Esterases/metabolismo
7.
J Biol Chem ; 299(5): 104659, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36997087

RESUMO

Decarboxylation of phosphatidylserine (PS) to form phosphatidylethanolamine by PS decarboxylases (PSDs) is an essential process in most eukaryotes. Processing of a malarial PSD proenzyme into its active alpha and beta subunits is by an autoendoproteolytic mechanism regulated by anionic phospholipids, with PS serving as an activator and phosphatidylglycerol (PG), phosphatidylinositol, and phosphatidic acid acting as inhibitors. The biophysical mechanism underlying this regulation remains unknown. We used solid phase lipid binding, liposome-binding assays, and surface plasmon resonance to examine the binding specificity of a processing-deficient Plasmodium PSD (PkPSDS308A) mutant enzyme and demonstrated that the PSD proenzyme binds strongly to PS and PG but not to phosphatidylethanolamine and phosphatidylcholine. The equilibrium dissociation constants (Kd) of PkPSD with PS and PG were 80.4 nM and 66.4 nM, respectively. The interaction of PSD with PS is inhibited by calcium, suggesting that the binding mechanism involves ionic interactions. In vitro processing of WT PkPSD proenzyme was also inhibited by calcium, consistent with the conclusion that PS binding to PkPSD through ionic interactions is required for the proenzyme processing. Peptide mapping identified polybasic amino acid motifs in the proenzyme responsible for binding to PS. Altogether, the data demonstrate that malarial PSD maturation is regulated through a strong physical association between PkPSD proenzyme and anionic lipids. Inhibition of the specific interaction between the proenzyme and the lipids can provide a novel mechanism to disrupt PSD enzyme activity, which has been suggested as a target for antimicrobials, and anticancer therapies.


Assuntos
Carboxiliases , Malária , Fosfolipídeos , Plasmodium , Motivos de Aminoácidos , Cálcio/metabolismo , Cálcio/farmacologia , Carboxiliases/antagonistas & inibidores , Carboxiliases/química , Carboxiliases/metabolismo , Precursores Enzimáticos/metabolismo , Lipossomos , Ácidos Fosfatídicos/metabolismo , Ácidos Fosfatídicos/farmacologia , Fosfatidilcolinas/metabolismo , Fosfatidilcolinas/farmacologia , Fosfatidiletanolaminas/metabolismo , Fosfatidiletanolaminas/farmacologia , Fosfatidilgliceróis/metabolismo , Fosfatidilgliceróis/farmacologia , Fosfatidilinositóis/metabolismo , Fosfatidilinositóis/farmacologia , Fosfatidilserinas/metabolismo , Fosfatidilserinas/farmacologia , Fosfolipídeos/química , Fosfolipídeos/metabolismo , Fosfolipídeos/farmacologia , Ligação Proteica , Malária/parasitologia , Proteólise/efeitos dos fármacos , Ressonância de Plasmônio de Superfície , Plasmodium/enzimologia
8.
Noncoding RNA Res ; 8(2): 164-173, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36632615

RESUMO

Radiotherapy is widely used for cancer treatment, but paradoxically, it has been reported that surviving cancer cells can acquire resistance, leading to recurrence or metastasis. Efforts to reduce radioresistance are required to increase the effectiveness of radiotherapy. miRNAs are advantageous as therapeutic agents because it can simultaneously inhibit the expression of several target mRNAs. Therefore, this study discovered miRNA that regulated radioresistance and elucidated its signaling mechanism. Our previous study confirmed that miR-5088-5p was associated with malignancy and metastasis in breast cancer. As a study to clarify the relationship between radiation and miR-5088-5p identified as onco-miRNA, it was confirmed that radiation induced hypomethylation of the promoter of miR-5088-5p and its expression increased. On the other hand, miR-5088-5p inhibitors were confirmed to reduce radiation-induced epithelial-mesenchymal transition, stemness, and metastasis by reducing Slug. Therefore, this study showed the potential of miR-5088-5p inhibitors as therapeutic agents to suppress radioresistance.

9.
Front Cell Infect Microbiol ; 12: 1039197, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36506011

RESUMO

The significant rise in the number of tick-borne diseases represents a major threat to public health worldwide. One such emerging disease is human babesiosis, which is caused by several protozoan parasites of the Babesia genus of which B. microti is responsible for most clinical cases reported to date. Recent studies have shown that during its intraerythrocytic life cycle, B. microti exports several antigens into the mammalian host using a novel vesicular-mediated secretion mechanism. One of these secreted proteins is the immunodominant antigen BmGPI12, which has been demonstrated to be a reliable biomarker of active B. microti infection. The major immunogenic determinants of this antigen remain unknown. Here we provide a comprehensive molecular and serological characterization of a set of eighteen monoclonal antibodies developed against BmGPI12 and a detailed profile of their binding specificity and suitability in the detection of active B. microti infection. Serological profiling and competition assays using synthetic peptides identified five unique epitopes on the surface of BmGPI12 which are recognized by a set of eight monoclonal antibodies. ELISA-based antigen detection assays identified five antibody combinations that specifically detect the secreted form of BmGPI12 in plasma samples from B. microti-infected mice and humans but not from other Babesia species or P. falciparum.


Assuntos
Babesia microti , Babesia , Gastrópodes , Malária Falciparum , Humanos , Animais , Camundongos , Epitopos , Anticorpos Monoclonais , Epitopos Imunodominantes , Mamíferos
10.
Structure ; 30(11): 1494-1507.e6, 2022 11 03.
Artigo em Inglês | MEDLINE | ID: mdl-36167065

RESUMO

Fungal infections are the leading cause of mortality by eukaryotic pathogens, with an estimated 150 million severe life-threatening cases and 1.7 million deaths reported annually. The rapid emergence of multidrug-resistant fungal isolates highlights the urgent need for new drugs with new mechanisms of action. In fungi, pantothenate phosphorylation, catalyzed by PanK enzyme, is the first step in the utilization of pantothenic acid and coenzyme A biosynthesis. In all fungi sequenced so far, this enzyme is encoded by a single PanK gene. Here, we report the crystal structure of a fungal PanK alone as well as with high-affinity inhibitors from a single chemotype identified through a high-throughput chemical screen. Structural, biochemical, and functional analyses revealed mechanisms governing substrate and ligand binding, dimerization, and catalysis and helped identify new compounds that inhibit the growth of several Candida species. The data validate PanK as a promising target for antifungal drug development.


Assuntos
Antifúngicos , Fosfotransferases (Aceptor do Grupo Álcool) , Antifúngicos/farmacologia , Fosfotransferases (Aceptor do Grupo Álcool)/genética , Fosfotransferases (Aceptor do Grupo Álcool)/metabolismo , Ácido Pantotênico/química , Ácido Pantotênico/metabolismo , Fungos
11.
J Clin Microbiol ; 60(9): e0092522, 2022 09 21.
Artigo em Inglês | MEDLINE | ID: mdl-36040206

RESUMO

The apicomplexan pathogen Babesia microti is responsible for most cases of human babesiosis worldwide. The disease, which presents as a malaria-like illness, is potentially fatal in immunocompromised or elderly patients, making the need for its accurate and early diagnosis an urgent public health concern. B. microti is transmitted primarily by Ixodes ticks but can also be transmitted via blood transfusion. The parasite completes its asexual reproduction in the host red blood cell, where each invading merozoite develops and multiplies to produce four daughter parasites. While various techniques, such as microscopy, PCR, and indirect fluorescence, have been used over the years for babesiosis diagnosis, detection of the secreted B. microti immunodominant antigen BmGPI12 using specific polyclonal antibodies was found to be the most effective method for the diagnosis of active infection and for evaluation of clearance following drug treatment. Here, we report the development of a panel of 16 monoclonal antibodies against BmGPI12. These antibodies detected secreted BmGPI12 in the plasma of infected humans. Antigen capture assays identified a combination of two monoclonal antibodies, 4C8 and 1E11, as a basis for a monoclonal antibody-based BmGPI12 capture assay (mGPAC) to detect active B. microti infection. Using a collection of 105 previously characterized human plasma samples, the mGPAC assay showed 97.1% correlation with RNA-based PCR (transcription-mediated amplification [TMA]) for positive and negative samples. The mGPAC assay also detected BmGPI12 in the plasma of six babesiosis patients at the time of diagnosis but not in three matched posttreatment samples. The mGPAC assay could thus be used alone or in combination with other assays for accurate detection of active B. microti infection.


Assuntos
Babesia microti , Babesiose , Idoso , Anticorpos Monoclonais , Antígenos de Protozoários , Babesia microti/genética , Babesiose/diagnóstico , Humanos , RNA
12.
Disaster Med Public Health Prep ; 16(1): 8-11, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-32843109

RESUMO

OBJECTIVE: A disaster in the hospital is particularly serious and quite different from other ordinary disasters. This study aimed at analyzing the activity outcomes of a disaster medical assistance team (DMAT) for a fire disaster at the hospital. METHODS: The data which was documented by a DMAT and emergent medical technicians of a fire department contained information about the patient's characteristics, medical records, triage results, and the hospital which the patient was transferred from. Patients were categorized into four groups according to results of field triage using the simple triage and rapid treatment method. RESULTS: DMAT arrived on the scene in 37 minutes. One hundred and thirty eight (138) patients were evacuated from the disaster scene. There were 25 patients (18.1%) in the Red group, 96 patients (69.6%) in the Yellow group, and 1 patient (0.7%) in the Green group. One patient died. There were 16 (11.6%) medical staff and hospital employees. The injury of the caregiver or the medical staff was more severe compared to the family protector. CONCLUSIONS: For an effective disaster-response system in hospital disasters, it is important to secure the safety of medical staff, to utilize available medical resources, to secure patients' medical records, and to reorganize the DMAT dispatch system.


Assuntos
Planejamento em Desastres , Serviços Médicos de Emergência , Incidentes com Feridos em Massa , Planejamento em Desastres/métodos , Hospitais , Humanos , Assistência Médica , Triagem
13.
Int J Mol Sci ; 24(1)2022 Dec 27.
Artigo em Inglês | MEDLINE | ID: mdl-36613877

RESUMO

Human PANK1, PANK2, and PANK3 genes encode several pantothenate kinase isoforms that catalyze the phosphorylation of vitamin B5 (pantothenic acid) to phosphopantothenate, a critical step in the biosynthesis of the major cellular cofactor, Coenzyme A (CoA). Mutations in the PANK2 gene, which encodes the mitochondrial pantothenate kinase (PanK) isoform, have been linked to pantothenate-kinase associated neurodegeneration (PKAN), a debilitating and often fatal progressive neurodegeneration of children and young adults. While the biochemical properties of these enzymes have been well-characterized in vitro, their expression in a model organism such as yeast in order to probe their function under cellular conditions have never been achieved. Here we used three yeast mutants carrying missense mutations in the yeast PanK gene, CAB1, which are associated with defective growth at high temperature and iron, mitochondrial dysfunction, increased iron content, and oxidative stress, to assess the cellular function of human PANK genes and functional conservation of the CoA-controlled processes between humans and yeast. Overexpression of human PANK1 and PANK3 in these mutants restored normal cellular activity whereas complementation with PANK2 was partial and could only be achieved with an isoform, PanK2mtmΔ, lacking the mitochondrial transit peptide. These data, which demonstrate functional conservation of PanK activity between humans and yeast, set the stage for the use of yeast as a model system to investigate the impact of PKAN-associated mutations on the metabolic pathways altered in this disease.


Assuntos
Estresse Oxidativo , Neurodegeneração Associada a Pantotenato-Quinase , Saccharomyces cerevisiae , Humanos , Homeostase , Ferro/metabolismo , Mitocôndrias/genética , Mitocôndrias/metabolismo , Estresse Oxidativo/genética , Neurodegeneração Associada a Pantotenato-Quinase/metabolismo , Ácido Pantotênico , Fosfotransferases (Aceptor do Grupo Álcool)/metabolismo , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo
14.
Mol Ther Oncolytics ; 22: 368-379, 2021 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-34553025

RESUMO

Bcl-w, a member of the Bcl-2 family, is highly expressed in various solid tumor, including lung cancer, suggesting that it is involved in cancer cell survival and carcinogenesis. Solid cancer-induced hypoxia has been reported to increase angiogenesis, growth factor, gene instability, invasion, and metastasis. Despite many studies on the treatment of non-small cell lung cancer (NSCLC) with a high incidence rate, the survival rate of patients has not improved because the cancer cells acquired resistance to treatment. This study investigated the correlation between Bcl-w expression and hypoxia in tumor malignancy of NSCLC. Meanwhile, microRNAs (miRNAs) are involved in a variety of key signaling mechanisms associated with hypoxia. Therefore, we discovered miR-519d-3p, which inhibits the expression of Bcl-w and hypoxia-inducing factor (HIF)-1α, and found that it reduces hypoxia-induced tumorigenesis. Spearman's correlation analysis showed that the expression levels of miR-519d-3p and Bcl-w/HIF-1α were negatively correlated, respectively. This showed that miR-519d-3p can be used as a diagnostic biomarker and target therapy for NSCLC.

15.
Mol Ther Nucleic Acids ; 25: 127-142, 2021 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-34457998

RESUMO

Breast cancer is the most common female cancer in the world. Despite the active research on metastatic breast cancer, the treatment of breast cancer patients is still difficult because the mechanism is not well known. Therefore, research on new targets and mechanisms for diagnosis and treatment of breast cancer patients is required. On the other hand, microRNA (miRNA) has the advantage of simultaneously regulating the expression of many target genes, so it has been proposed as an effective biomarker for the treatment of various diseases including cancer. This study analyzed the role and mechanism of DBC2 (deleted in breast cancer 2), which is known to inhibit its expression in breast cancer, and proposed microRNA (miR)-5088-5p, which regulates its expression. It was revealed that the biogenesis of miR-5088-5p was upregulated by hypomethylation of its promoter, promoted by Fyn, and was involved in malignancy in breast cancer. With the use of the cellular level, clinical samples, and published data, we verified that the expression patterns of DBC2 and miR-5088-5p were negatively related, suggesting the potential as novel biomarkers for the diagnosis of breast cancer patients.

16.
J Biol Chem ; 295(27): 9211-9222, 2020 07 03.
Artigo em Inglês | MEDLINE | ID: mdl-32430397

RESUMO

Phosphatidylserine decarboxylases (PSDs) catalyze the conversion of phosphatidylserine (PS) to phosphatidylethanolamine (PE), a critical step in membrane biogenesis and a potential target for development of antimicrobial and anti-cancer drugs. PSD activity has typically been quantified using radioactive substrates and products. Recently, we described a fluorescence-based assay that measures the PSD reaction using distyrylbenzene-bis-aldehyde (DSB-3), whose reaction with PE produces a fluorescence signal. However, DSB-3 is not widely available and also reacts with PSD's substrate, PS, producing an adduct with lower fluorescence yield than that of PE. Here, we report a new fluorescence-based assay that is specific for PSD and in which the presence of PS causes only negligible background. This new assay uses 1,2-diacetyl benzene/ß-mercaptoethanol, which forms a fluorescent iso-indole-mercaptide conjugate with PE. PE detection with this method is very sensitive and comparable with detection by radiochemical methods. Model reactions examining adduct formation with ethanolamine produced stable products of exact masses (m/z) of 342.119 and 264.105. The assay is robust, with a signal/background ratio of 24, and can readily detect formation of 100 pmol of PE produced from Escherichia coli membranes, Candida albicans mitochondria, or HeLa cell mitochondria. PSD activity can easily be quantified by sequential reagent additions in 96- or 384-well plates, making it readily adaptable to high-throughput screening for PSD inhibitors. This new assay now enables straightforward large-scale screening for PSD inhibitors against pathogenic fungi, antibiotic-resistant bacteria, and neoplastic mammalian cells.


Assuntos
Carboxiliases/análise , Corantes Fluorescentes/síntese química , Espectrometria de Fluorescência/métodos , Acetofenonas/química , Candida albicans/metabolismo , Carboxiliases/metabolismo , Membrana Celular/metabolismo , Etanolamina , Fluorescência , Células HeLa , Ensaios de Triagem em Larga Escala , Humanos , Mercaptoetanol/química , Mitocôndrias , Fosfatidiletanolaminas/metabolismo , Fosfatidilserinas/metabolismo , Estirenos/química
17.
Mol Ther Nucleic Acids ; 17: 245-255, 2019 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-31272074

RESUMO

Glioblastoma multiforme (GBM), a particularly aggressive type of malignant brain tumor, has a high mortality rate. Bcl-w, an oncogene, is reported to enhance cell survival, proliferation, epithelial-mesenchymal transition (EMT), migratory and invasive abilities, and stemness maintenance in a variety of cancer cell types, including GBM. In this study, we confirmed that Bcl-w-induced conditional medium (CM) enhances tumorigenic phenotypes of migration, invasiveness, and stemness maintenance. Notably, platelet-derived growth factor-A (PDGF-A) expression, among other factors of the tumor environment, was increased by CM of Bcl-w-overexpressing cells, prompting investigation of the potential correlation between Bcl-w and PDGF-A and their effects on GBM malignancy. Bcl-w and PDGF-A levels were positively regulated and increased tumorigenicity by Sox2 activation in GBM cells. miR-340-5p was further identified as a direct inhibitor of Bcl-w and Sox2. Overexpression of miR-340-5p reduced mesenchymal traits, cell migration, invasion, and stemness in GBM through attenuating Bcl-w and Sox2 expression. Our novel findings highlight the potential utility of miR-340-5p as a therapeutic agent for glioblastoma multiforme through inhibitory effects on Bcl-w-induced PDGF-A and Sox2 activation.

18.
J Biol Chem ; 294(32): 12146-12156, 2019 08 09.
Artigo em Inglês | MEDLINE | ID: mdl-31227523

RESUMO

Phosphatidylserine decarboxylases (PSDs) catalyze the decarboxylation of phosphatidylserine to generate phosphatidylethanolamine, a critical step in phospholipid metabolism in both prokaryotes and eukaryotes. Most PSDs are membrane-bound, and classical radioisotope-based assays for determining their activity in vitro are not suitable for high-throughput drug screening. The finding that the PkPSD from Plasmodium knowlesi can be purified in a soluble and active form and the recent development of a fluorescence-based distyrylbenzene-bis-aldehyde (DSB-3) assay to measure PSD activity in vitro have laid the groundwork for screening chemical libraries for PSD inhibitors. Using this assay, here we conducted a high-throughput screen of a structurally diverse 130,858-compound library against PkPSD. Further characterization of the hits identified in this screening yielded five PkPSD inhibitors with IC50 values ranging from 3.1 to 42.3 µm Lead compounds were evaluated against the pathogenic yeast Candida albicans in the absence or presence of exogenous ethanolamine, and YU253467 and YU254403 were identified as inhibiting both native C. albicans PSD mitochondrial activity and C. albicans growth, with an MIC50 of 22.5 and 15 µg/ml without ethanolamine and an MIC50 of 75 and 60 µg/ml with ethanolamine, respectively. Together, these results provide the first proof of principle for the application of DSB-3-based fluorescent readouts in high-throughput screening for PSD inhibitors. The data set the stage for future analyses to identify more selective and potent PSD inhibitors with antimicrobial or antitumor activities.


Assuntos
Carboxiliases/antagonistas & inibidores , Inibidores Enzimáticos/análise , Corantes Fluorescentes/química , Ensaios de Triagem em Larga Escala , Estirenos/química , Candida albicans/efeitos dos fármacos , Carboxiliases/genética , Carboxiliases/metabolismo , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Inibidores Enzimáticos/metabolismo , Inibidores Enzimáticos/farmacologia , Etanolamina/farmacologia , Humanos , Concentração Inibidora 50 , Fosfatidilserinas/metabolismo , Plasmodium knowlesi/enzimologia , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/isolamento & purificação
19.
Arch Plast Surg ; 46(2): 135-139, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30934177

RESUMO

BACKGROUND: In immediate breast reconstruction using an extended latissimus dorsi musculocutaneous (eLDMC) flap, the volume of the flap decreases, which causes a secondary deformity of the breast shape. Since little research has investigated this decrease in muscle volume, the authors conducted an objective study to characterize the decrease in muscle volume after breast reconstruction using an eLDMC flap. METHODS: Research was conducted from October 2011 to November 2016. The subjects included 23 patients who underwent mastectomy due to breast cancer, received immediate reconstruction using an eLDMC flap without any adjuvant chemotherapy or radiotherapy, and received a computed tomography (CT) scan from days 7 to 10 after surgery and 6 to 8 months postoperatively. In 10 patients, an additional CT scan was conducted 18 months postoperatively. Axial CT scans were utilized to measure the volumetric change of the latissimus dorsi muscle during the follow-up period. RESULTS: In the 23 patients, an average decrease of 54.5% was observed in the latissimus dorsi muscle volume between the images obtained immediately postoperatively and the scans obtained 6 to 8 months after surgery. Ten patients showed an average additional decrease of 11.9% from 6-8 months to 18 months after surgery. CONCLUSIONS: We studied changes in the volume of the latissimus dorsi muscle after surgery using an eLDMC flap performed after a mastectomy without adjuvant chemotherapy or radiotherapy. In this study, we found that immediate breast reconstruction using a latissimus dorsi muscle flap led to a decrease in muscle volume of up to 50%.

20.
Mol Ther Nucleic Acids ; 14: 450-464, 2019 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-30743214

RESUMO

Although radiotherapy has been successfully applied to treat many cancer types, surviving cancer cells often acquire therapeutic resistance, leading to increased risk of local recurrence and distant metastases via modification of the tumor microenvironment. Previously, we reported that high expression of Bcl-w in cancer patients is significantly correlated with poor survival as well as malignant activity. However, the relationship between ionizing radiation (IR)-induced resistance and Bcl-w expression in cancer cells is currently unclear. We showed that IR-induced Bcl-w contributes to EMT (epithelial-mesenchymal transition), migration, angiogenesis, stemness maintenance, and metastasis by promoting the expression of factors related to these phenotypes, both in vitro and in vivo. Meanwhile, IR enhanced hypermethylation of miR-205-5p CpG islands through Src activation, leading to decreased miR-205-5p expression and, in turn, potentially stimulating Bcl-w-mediated malignant activity and metastasis. The clinical applicability of Bcl-w and miR-205-5p from cells or animal models was confirmed using tissues and plasma of breast carcinoma patients. Based on the collective findings, we propose that miR-205-5ps as important negative mediators of resistance in radiotherapy could serve as useful potential targets of concurrently applied genetic therapy aimed to inhibit tumor aggressiveness and enhance the efficiency of radiotherapy in cancer patients.

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