RESUMEN
The disease severity of coronavirus disease 2019 (COVID-19) varies considerably from asymptomatic to serious, with fatal complications associated with dysregulation of innate and adaptive immunity. Lymphoid depletion in lymphoid tissues and lymphocytopenia have both been associated with poor disease outcomes in patients with COVID-19, but the mechanisms involved remain elusive. In this study, human angiotensin-converting enzyme 2 (hACE2) transgenic mouse models susceptible to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection were used to investigate the characteristics and determinants of lethality associated with the lymphoid depletion observed in SARS-CoV-2 infection. The lethality of Wuhan SARS-CoV-2 infection in K18-hACE2 mice was characterized by severe lymphoid depletion and apoptosis in lymphoid tissues related to fatal neuroinvasion. The lymphoid depletion was associated with a decreased number of antigen-presenting cells (APCs) and their suppressed functionality below basal levels. Lymphoid depletion with reduced APC function was a specific feature observed in SARS-CoV-2 infection but not in influenza A infection and had the greatest prognostic value for disease severity in murine COVID-19. Comparison of transgenic mouse models resistant and susceptible to SARS-CoV-2 infection revealed that suppressed APC function could be determined by the hACE2 expression pattern and interferon-related signaling. Thus, we demonstrated that lymphoid depletion associated with suppressed APC function characterizes the lethality of COVID-19 mouse models. Our data also suggest a potential therapeutic approach to prevent the severe progression of COVID-19 by enhancing APC functionality.
Asunto(s)
COVID-19 , Ratones , Humanos , Animales , SARS-CoV-2/metabolismo , Peptidil-Dipeptidasa A/metabolismo , Ratones Transgénicos , Susceptibilidad a Enfermedades , Células Presentadoras de Antígenos , Modelos Animales de Enfermedad , Pulmón/metabolismoRESUMEN
Four tunicamycin class compounds, tunicamycin VII (1), tunicamycin VIII (2), corynetoxin U17a (3), and tunicamycin IX (4), were isolated from the culture broth of the marine-derived actinomycete Streptomyces sp. MBTG32. The strain was identified using the 16S rDNA sequencing technique, and the isolated strain was closely related to Streptomyces bacillaris. The structures of the isolated compounds were elucidated based on spectroscopic data and comparisons with previously reported NMR data. Compounds 1-4 showed potent antibacterial activities against Gram-positive bacteria, especially Staphylococcus aureus, with MIC values of 0.13-0.25 µg/mL. Through a recombinant enzyme assay and overexpression analysis, we found that the isolated compounds exerted potent inhibitory effects on S. aureus MurNAc-pentapeptide translocase (MraY), with IC50 values of 0.08-0.21 µg/mL. The present results support that the underlying mechanism of action of tunicamycins isolated from marine-derived Streptomyces sp. is also associated with the inhibition of MraY enzyme activity in S. aureus.
Asunto(s)
Antibacterianos , Proteínas Bacterianas , Pruebas de Sensibilidad Microbiana , Staphylococcus aureus , Streptomyces , Tunicamicina , Staphylococcus aureus/efectos de los fármacos , Tunicamicina/farmacología , Antibacterianos/farmacología , Antibacterianos/aislamiento & purificación , Antibacterianos/química , Proteínas Bacterianas/metabolismo , Transferasas (Grupos de Otros Fosfatos Sustitutos) , Transferasas/antagonistas & inhibidores , Transferasas/metabolismo , Organismos AcuáticosRESUMEN
Throughout the recent COVID-19 pandemic, South Korea led national efforts to develop vaccines and therapeutics for SARS-CoV-2. The project proceeded as follows: 1) evaluation system setup (including Animal Biosafety Level 3 (ABSL3) facility alliance, standardized nonclinical evaluation protocol, and laboratory information management system), 2) application (including committee review and selection), and 3) evaluation (including expert judgment and reporting). After receiving 101 applications, the selection committee reviewed pharmacokinetics, toxicity, and efficacy data and selected 32 final candidates. In the nonclinical efficacy test, we used golden Syrian hamsters and human angiotensin-converting enzyme 2 transgenic mice under a cytokeratin 18 promoter to evaluate mortality, clinical signs, body weight, viral titer, neutralizing antibody presence, and histopathology. These data indicated eight new drugs and one repositioned drug having significant efficacy for COVID-19. Three vaccine and four antiviral drugs exerted significant protective activities against SARS-CoV-2 pathogenesis. Additionally, two anti-inflammatory drugs showed therapeutic effects on lung lesions and weight loss through their mechanism of action but did not affect viral replication. Along with systematic verification of COVID-19 animal models through large-scale studies, our findings suggest that ABSL3 multicenter alliance and nonclinical evaluation protocol standardization can promote reliable efficacy testing against COVID-19, thus expediting medical product development.
Asunto(s)
COVID-19 , Animales , Cricetinae , Ratones , Humanos , SARS-CoV-2 , Pandemias , Anticuerpos Neutralizantes , Mesocricetus , Modelos Animales de EnfermedadRESUMEN
Nuclear factor kappa B (NF-κB) signaling pathways progress inflammation and immune cell differentiation in the host immune response; however, the uncontrollable stimulation of NF-κB signaling is responsible for several inflammatory illnesses regardless of whether the conditions are acute or chronic. Innate immune cells, such as macrophages, microglia, and Kupffer cells, secrete pro-inflammatory cytokines, such as TNF-α, IL-6, and IL-1ß, via the activation of NF-κB subunits, which may lead to the damage of normal cells, including neurons, cardiomyocytes, hepatocytes, and alveolar cells. This results in the occurrence of neurodegenerative disorders, cardiac infarction, or liver injury, which may eventually lead to systemic inflammation or cancer. Recently, ginsenosides from Panax ginseng, a historical herbal plant used in East Asia, have been used as possible options for curing inflammatory diseases. All of the ginsenosides tested target different steps of the NF-κB signaling pathway, ameliorating the symptoms of severe illnesses. Moreover, ginsenosides inhibit the NF-κB-mediated activation of cancer metastasis and immune resistance, significantly attenuating the expression of MMPs, Snail, Slug, TWIST1, and PD-L1. This review introduces current studies on the therapeutic efficacy of ginsenosides in alleviating NF-κB responses and emphasizes the critical role of ginsenosides in severe inflammatory diseases as well as cancers.
Asunto(s)
Antineoplásicos , Ginsenósidos , Panax , FN-kappa B/metabolismo , Ginsenósidos/farmacología , Ginsenósidos/uso terapéutico , Panax/metabolismo , Transducción de Señal , Antiinflamatorios/farmacología , Antiinflamatorios/uso terapéutico , Inflamación/tratamiento farmacológico , Antineoplásicos/farmacologíaRESUMEN
Muscle atrophy, also known as muscle wasting, is the thinning of muscle mass due to muscle disuse, aging, or diseases such as cancer or neurological problems. Muscle atrophy is closely related to the quality of life and has high morbidity and mortality. However, therapeutic options for muscle atrophy are limited, so studies to develop therapeutic agents for muscle loss are always required. For this study, we investigated how orally administered specific collagen peptides (CP) affect muscle atrophy and elucidated its molecular mechanism using an in vivo model. We treated mice with dexamethasone (DEX) to induce a muscular atrophy phenotype and then administered CP (0.25 and 0.5 g/kg) for four weeks. In a microcomputed tomography analysis, CP (0.5 g/kg) intake significantly increased the volume of calf muscles in mice with DEX-induced muscle atrophy. In addition, the administration of CP (0.25 and 0.5 g/kg) restored the weight of the gluteus maximus and the fiber cross-sectional area (CSA) of the pectoralis major and calf muscles, which were reduced by DEX. CP significantly inhibited the mRNA expression of myostatin and the phosphorylation of Smad2, but it did not affect TGF-ß, BDNF, or FNDC5 gene expression. In addition, AKT/mTOR, a central pathway for muscle protein synthesis and related to myostatin signaling, was enhanced in the groups that were administered CP. Finally, CP decreased serum albumin levels and increased TNF-α gene expression. Collectively, our in vivo results demonstrate that CP can alleviate muscle wasting through a multitude of mechanisms. Therefore, we propose CP as a supplement or treatment to prevent muscle atrophy.
Asunto(s)
Colágeno , Atrofia Muscular , Miostatina , Animales , Ratones , Dexametasona/efectos adversos , Fibronectinas/metabolismo , Músculo Esquelético/metabolismo , Atrofia Muscular/inducido químicamente , Atrofia Muscular/metabolismo , Microtomografía por Rayos X , Colágeno/farmacologíaRESUMEN
In mammals, environmental cold sensing conducted by peripheral cold thermoreceptor neurons mostly depends on TRPM8, an ion channel that has evolved to become the main molecular cold transducer. This TRP channel is activated by cold, cooling compounds, such as menthol, voltage, and rises in osmolality. TRPM8 function is regulated by kinase activity that phosphorylates the channel under resting conditions. However, which specific residues, how this post-translational modification modulates TRPM8 activity, and its influence on cold sensing are still poorly understood. By mass spectrometry, we identified four serine residues within the N-terminus (S26, S29, S541, and S542) constitutively phosphorylated in the mouse ortholog. TRPM8 function was examined by Ca2+ imaging and patch-clamp recordings, revealing that treatment with staurosporine, a kinase inhibitor, augmented its cold- and menthol-evoked responses. S29A mutation is sufficient to increase TRPM8 activity, suggesting that phosphorylation of this residue is a central molecular determinant of this negative regulation. Biophysical and total internal reflection fluorescence-based analysis revealed a dual mechanism in the potentiated responses of unphosphorylated TRPM8: a shift in the voltage activation curve toward more negative potentials and an increase in the number of active channels at the plasma membrane. Importantly, basal kinase activity negatively modulates TRPM8 function at cold thermoreceptors from male and female mice, an observation accounted for by mathematical modeling. Overall, our findings suggest that cold temperature detection could be rapidly and reversibly fine-tuned by controlling the TRPM8 basal phosphorylation state, a mechanism that acts as a dynamic molecular brake of this thermo-TRP channel function in primary sensory neurons.SIGNIFICANCE STATEMENT Post-translational modifications are one of the main molecular mechanisms involved in adjusting the sensitivity of sensory ion channels to changing environmental conditions. Here we show, for the first time, that constitutive phosphorylation of the well-conserved serine 29 within the N-terminal domain negatively modulates TRPM8 channel activity, reducing its activation by agonists and decreasing the number of active channels at the plasma membrane. Basal phosphorylation of TRPM8 acts as a key regulator of its function as the main cold-transduction channel, significantly contributing to the net response of primary sensory neurons to temperature reductions. This reversible and dynamic modulatory mechanism opens new opportunities to regulate TRPM8 function in pathologic conditions where this thermo-TRP channel plays a critical role.
Asunto(s)
Membrana Celular/genética , Membrana Celular/metabolismo , Canales Catiónicos TRPM/genética , Canales Catiónicos TRPM/metabolismo , Animales , Células COS , Chlorocebus aethiops , Femenino , Células HEK293 , Humanos , Masculino , Ratones , Ratones Endogámicos C57BL , Fosforilación/fisiología , Ganglio del Trigémino/metabolismoRESUMEN
Two nitrogenous metabolites, bacillimide (1) and bacillapyrrole (2), were isolated from the culture broth of the marine-derived actinomycete Streptomyces bacillaris. Based on the results of combined spectroscopic and chemical analyses, the structure of bacillimide (1) was determined to be a new cyclopenta[c]pyrrole-1,3-dione bearing a methylsulfide group, while the previously reported bacillapyrrole (2) was fully characterized for the first time as a pyrrole-carboxamide bearing an alkyl sulfoxide side chain. Bacillimide (1) and bacillapyrrole (2) exerted moderate (IC50 = 44.24 µM) and weak (IC50 = 190.45 µM) inhibitory effects on Candida albicans isocitrate lyase, respectively. Based on the growth phenotype using icl-deletion mutants and icl expression analyses, we determined that bacillimide (1) inhibits the transcriptional level of icl in C. albicans under C2-carbon-utilizing conditions.
Asunto(s)
Antifúngicos/farmacología , Candida albicans/efectos de los fármacos , Isocitratoliasa/efectos de los fármacos , Streptomyces/metabolismo , Antifúngicos/aislamiento & purificación , Candida albicans/enzimología , Concentración 50 Inhibidora , Pruebas de Sensibilidad Microbiana , Nitrógeno/metabolismoRESUMEN
Four epipolythiodioxopiperazine fungal metabolites (1-4) isolated from the sponge-derived Aspergillus quadrilineatus FJJ093 were evaluated for their capacity to inhibit isocitrate lyase (ICL) in the glyoxylate cycle of Candida albicans. The structures of these compounds were elucidated using spectroscopic techniques and comparisons with previously reported data. We found secoemestrin C (1) (an epitetrathiodioxopiperazine derivative) to be a potent ICL inhibitor, with an inhibitory concentration of 4.77 ± 0.08 µM. Phenotypic analyses of ICL-deletion mutants via growth assays with acetate as the sole carbon source demonstrated that secoemestrin C (1) inhibited C. albicans ICL. Semi-quantitative reverse-transcription polymerase chain reaction analyses indicated that secoemestrin C (1) inhibits ICL mRNA expression in C. albicans under C2-assimilating conditions.
Asunto(s)
Candida albicans/efectos de los fármacos , Proteínas Fúngicas/antagonistas & inhibidores , Isocitratoliasa/antagonistas & inhibidores , Piperazinas/farmacología , Aspergillus/metabolismo , Candida albicans/genética , Candida albicans/metabolismo , Proteínas Fúngicas/química , Proteínas Fúngicas/genética , Glioxilatos/metabolismo , Isocitratoliasa/química , Isocitratoliasa/genética , Piperazinas/química , Piperazinas/metabolismo , Proteínas Recombinantes/químicaRESUMEN
Ochraceopetalin (1), a mixed-biogenetic salt compound and its component 2 were isolated from the culture broths of a marine-derived fungus, Aspergillus ochraceopetaliformis. Based on combined spectroscopic and chemical analyses, the structure of 1 was determined to be a sulfonated diphenylether-aminol-amino acid ester guanidinium salt of an unprecedented structural class, while 2 was determined to be the corresponding sulfonated diphenylether. Ochraceopetaguanidine (3), the other guanidine-bearing aminol amino acid ester component, was also prepared and structurally elucidated. Compound 1 exhibited significant cytotoxicity against K562 and A549 cells.
Asunto(s)
Antineoplásicos/farmacología , Aspergillus/química , Células A549/efectos de los fármacos , Organismos Acuáticos , Humanos , Células K562/efectos de los fármacos , Relación Estructura-ActividadRESUMEN
Three new bianthraquinones, alterporriol Z1-Z3 (1-3), along with three known compounds of the same structural class, were isolated from the culture broth of a marine-derived Stemphylium sp. fungus. Based upon the results of spectroscopic analyses and ECD measurements, the structures of new compounds were determined to be the 6-6'- (1 and 2) and 1-5'- (3) C-C connected pseudo-dimeric anthraquinones, respectively. Three new meroterpenoids, tricycloalterfurenes E-G (7-9), isolated together with the bianthraquinones from the same fungal culture broth, were structurally elucidated by combined spectroscopic methods. The relative and absolute configurations of these meroterpenoids were determined by modified Mosher's, phenylglycine methyl ester (PGME), and computational methods. The bianthraquinones significantly inhibited nitric oxide (NO) production and suppressed inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) expression in LPS-stimulated RAW 264.7 cells.
Asunto(s)
Antraquinonas/farmacología , Antiinflamatorios/farmacología , Ascomicetos/química , Macrófagos/efectos de los fármacos , Terpenos/farmacología , Animales , Antraquinonas/química , Antraquinonas/aislamiento & purificación , Antiinflamatorios/química , Antiinflamatorios/aislamiento & purificación , Bacterias/efectos de los fármacos , Línea Celular Tumoral , Ciclooxigenasa 2/metabolismo , Humanos , Macrófagos/metabolismo , Ratones , Óxido Nítrico/metabolismo , Óxido Nítrico Sintasa de Tipo II/metabolismo , Poríferos/microbiología , Células RAW 264.7 , Terpenos/química , Terpenos/aislamiento & purificaciónRESUMEN
Seven alkaloidal compounds (2-8) and one polyketide (1) were isolated from a semisolid rice culture of the marine-derived fungus Aspergillus sp. F452. Structures of the isolated compounds were elucidated based on spectroscopic data and comparisons with previously reported data. The alkaloidal compounds (2-8) displayed weak to moderate inhibitory activities against Staphylococcus aureus-derived sortase A (SrtA) without affecting cell viability. Aspermytin A (1) strongly inhibited SrtA activity, with an IC50 value of 146.0 µM, and significantly reduced bacterial adherence to fibronectin-coated surfaces. The present results indicate that the underlying mechanism of action of compound 1 is associated with the inhibition of SrtA-mediated S. aureus adhesion to fibronectin, thus potentially serving as an SrtA inhibitor.
Asunto(s)
Alcaloides/farmacología , Aminoaciltransferasas/antagonistas & inhibidores , Antibacterianos/farmacología , Aspergillus/metabolismo , Proteínas Bacterianas/antagonistas & inhibidores , Inhibidores Enzimáticos/farmacología , Staphylococcus aureus/efectos de los fármacos , Alcaloides/aislamiento & purificación , Aminoaciltransferasas/metabolismo , Antibacterianos/aislamiento & purificación , Adhesión Bacteriana/efectos de los fármacos , Proteínas Bacterianas/metabolismo , Línea Celular Tumoral , Cisteína Endopeptidasas/metabolismo , Inhibidores Enzimáticos/aislamiento & purificación , Fibronectinas/metabolismo , Humanos , Cinética , Estructura Molecular , Staphylococcus aureus/enzimología , Relación Estructura-ActividadRESUMEN
Six new bis(indole) alkaloids (1-6) along with eight known ones of the topsentin class were isolated from a Spongosorites sp. sponge of Korea. Based on the results of combined spectroscopic analyses, the structures of spongosoritins A-D (1-4) were determined to possess a 2-methoxy-1-imidazole-5-one core connecting the indole moieties, and these were linked by a linear urea bridge for spongocarbamides A (5) and B (6). The absolute configurations of spongosoritins were assigned by electronic circular dichroism (ECD) computation. The new compounds exhibited moderate inhibition against transpeptidase sortase A and weak inhibition against human pathogenic bacteria and A549 and K562 cancer cell lines.
Asunto(s)
Antibacterianos/farmacología , Antifúngicos/farmacología , Antineoplásicos/farmacología , Alcaloides Indólicos/farmacología , Poríferos/metabolismo , Células A549 , Aminoaciltransferasas/antagonistas & inhibidores , Aminoaciltransferasas/metabolismo , Animales , Antibacterianos/aislamiento & purificación , Antifúngicos/aislamiento & purificación , Antineoplásicos/aislamiento & purificación , Bacterias/efectos de los fármacos , Bacterias/enzimología , Bacterias/crecimiento & desarrollo , Proteínas Bacterianas/antagonistas & inhibidores , Proteínas Bacterianas/metabolismo , Supervivencia Celular/efectos de los fármacos , Cisteína Endopeptidasas/metabolismo , Hongos/efectos de los fármacos , Hongos/crecimiento & desarrollo , Humanos , Alcaloides Indólicos/aislamiento & purificación , Células K562 , Pruebas de Sensibilidad Microbiana , Estructura Molecular , Neoplasias/tratamiento farmacológico , Neoplasias/patología , Relación Estructura-ActividadRESUMEN
In brain ischemia, oxidative stress induces neuronal apoptosis, which is mediated by increased activity of the voltage-gated K+ channel Kv2.1 and results in an efflux of intracellular K+. The molecular mechanisms underlying the regulation of Kv2.1 and its activity during brain ischemia are not yet fully understood. Here this study provides evidence that oxidant-induced apoptosis resulting from brain ischemia promotes rapid tyrosine phosphorylation of Kv2.1. When the tyrosine phosphorylation sites Y124, Y686, and Y810 on the Kv2.1 channel are mutated to non-phosphorylatable residues, PARP-1 cleavage levels decrease, indicating suppression of neuronal cell death. The tyrosine residue Y810 on Kv2.1 was a major phosphorylation site. In fact, cells mutated Y810 were more viable in our study than were wild-type cells, suggesting an important role for this site during ischemic neuronal injury. In an animal model, tyrosine phosphorylation of Kv2.1 increased after ischemic brain injury, with an observable sustained increase for at least 2 h after reperfusion. These results demonstrate that tyrosine phosphorylation of the Kv2.1 channel in the brain may play a critical role in regulating neuronal ischemia and is therefore a potential therapeutic target in patients with brain ischemia.
Asunto(s)
Apoptosis/genética , Isquemia Encefálica/metabolismo , Canales de Potasio Shab/metabolismo , Tirosina/metabolismo , 2,2'-Dipiridil/análogos & derivados , 2,2'-Dipiridil/farmacología , Animales , Apoptosis/efectos de los fármacos , Isquemia Encefálica/genética , Supervivencia Celular/efectos de los fármacos , Supervivencia Celular/genética , Disulfuros/farmacología , Células HEK293 , Humanos , Inmunohistoquímica , Masculino , Ratones , Ratones Endogámicos C57BL , Mutación , Neuronas/efectos de los fármacos , Neuronas/metabolismo , Estrés Oxidativo/efectos de los fármacos , Fosforilación , Poli(ADP-Ribosa) Polimerasa-1/metabolismo , Ratas , Canales de Potasio Shab/genéticaRESUMEN
Four new peptides were isolated from the culture broths of the marine-derived fungi Aspergillus allahabadii and A. ochraceopetaliformis. Based on the results of chemical and spectroscopic analyses, two compounds (1 and 2) from A. allahabadii were determined to be cyclopentapeptides, while those from A. ochraceopetaliformis were a structurally-related cyclodepsihexapeptide (3) and its linear analog (4). In addition to the presence of a D-amino acid residue, the almost reversed sequence of peptides in 3 and 4, relative to those of the 1 and 2, is notable. These new compounds exhibited moderate inhibition against the enzyme sortase A as well as a weak inhibition against isocitrate lyase (2).
Asunto(s)
Antibacterianos/farmacología , Aspergillus/química , Bacterias/efectos de los fármacos , Péptidos Cíclicos/farmacología , Aminoaciltransferasas/antagonistas & inhibidores , Antibacterianos/química , Antibacterianos/aislamiento & purificación , Bacterias/enzimología , Proteínas Bacterianas/antagonistas & inhibidores , Cisteína Endopeptidasas , Pruebas de Enzimas , Sedimentos Geológicos/microbiología , Isocitratoliasa/antagonistas & inhibidores , Pruebas de Sensibilidad Microbiana , Estructura Molecular , Péptidos Cíclicos/química , Péptidos Cíclicos/aislamiento & purificaciónRESUMEN
Four 2-alkyl-4-hydroxyquinoline derivatives (1â»4) were isolated from a semisolid rice culture of the marine-derived actinomycete Streptomyces sp. MBTG13. The structures of these compounds were elucidated by a combination of spectroscopic methods, and their data were in good agreement with previous reports. Compounds 1 and 2 exhibited weak to moderate antibacterial activity against pathogenic bacteria. Unexpectedly, we found that compound 1 acted as a potent inhibitor of hyphal growth induction in the dimorphic fungus Candida albicans, with an IC50 value of 11.4 µg/mL. Growth experiments showed that this compound did not inhibit yeast cell growth, but inhibited hyphal growth induction. Semi-quantitative reverse transcription (RT)-PCR analysis of hyphal-inducing signaling pathway components indicated that compound 1 inhibited the expression of mRNAs related to the cAMP-Efg1 pathway. The expression of HWP1 and ALS3 mRNAs (hypha-specific genes positively regulated by Efg1, an important regulator of cell wall dynamics) was significantly inhibited by the addition of compound 1. These results indicate that compound 1 acts on the Efg1-mediated cAMP pathway and regulates hyphal growth in Candida albicans.
Asunto(s)
Candida albicans/efectos de los fármacos , Hidroxiquinolinas/farmacología , Hifa/efectos de los fármacos , Streptomyces/química , Antifúngicos , Candida albicans/crecimiento & desarrollo , Regulación Fúngica de la Expresión Génica , Inhibidores de Crecimiento/farmacología , Hidroxiquinolinas/química , Hidroxiquinolinas/aislamiento & purificación , Hifa/crecimiento & desarrollo , Transducción de Señal , Streptomyces/metabolismoRESUMEN
The glyoxylate cycle is a sequence of anaplerotic reactions catalyzed by the key enzymes isocitrate lyase (ICL) and malate synthase, and plays an important role in the pathogenesis of microorganisms during infection. An icl-deletion mutant of Candida albicans exhibited reduced virulence in mice compared with the wild type. Five diketopiperazines, which are small and stable cyclic peptides, isolated from the marine-derived Streptomyces puniceus Act1085, were evaluated for their inhibitory effects on C. albicans ICL. The structures of these compounds were elucidated based on spectroscopic data and comparisons with previously reported data. Cyclo(L-Phe-L-Val) was identified as a potent ICL inhibitor, with a half maximal inhibitory concentration of 27 µg/mL. Based on the growth phenotype of the icl-deletion mutants and icl expression analyses, we demonstrated that cyclo(L-Phe-L-Val) inhibits the gene transcription of ICL in C. albicans under C2-carbon-utilizing conditions.
Asunto(s)
Organismos Acuáticos/química , Candida albicans/efectos de los fármacos , Candida albicans/enzimología , Dicetopiperazinas/química , Dicetopiperazinas/farmacología , Isocitratoliasa/antagonistas & inhibidores , Streptomyces/química , Relación Dosis-Respuesta a Droga , Pruebas de Sensibilidad Microbiana , Estructura Molecular , Relación Estructura-Actividad , Especificidad por SustratoRESUMEN
Fluorescence detecting of exogenous EpCAM (epithelial cell adhesion molecule) or muc1 (mucin1) expression correlated to cancer metastasis using nanoparticles provides pivotal information on CTC (circulating tumor cell) occurrence in a noninvasive tool. In this study, we study a new skill to detect extracellular EpCAM/muc1 using quantum dot-based aptamer beacon (QD-EpCAM/muc1 ALB (aptamer linker beacon). The QD-EpCAM/muc1 ALB was designed using QDs (quantum dots) and probe. The EpCAM/muc1-targeting aptamer contains a Ep-CAM/muc1 binding sequence and BHQ1 (black hole quencher 1) or BHQ2 (black hole quencher2). In the absence of target EpCAM/muc1, the QD-EpCAM/muc1 ALB forms a partial duplex loop-like aptamer beacon and remained in quenched state because the BHQ1/2 quenches the fluorescence signal-on of the QD-EpCAM/muc1 ALB. The binding of EpCAM/muc1 of CTC to the EpCAM/muc1 binding aptamer sequence of the EpCAM/muc1-targeting oligonucleotide triggered the dissociation of the BHQ1/2 quencher and subsequent signal-on of a green/red fluorescence signal. Furthermore, acute inflammation was stimulated by trigger such as caerulein in vivo, which resulted in increased fluorescent signal of the cy5.5-EpCAM/muc1 ALB during cancer metastasis due to exogenous expression of EpCAM/muc1 in Panc02-implanted mouse model.
Asunto(s)
Células Neoplásicas Circulantes/patología , Animales , Aptámeros de Nucleótidos/metabolismo , Línea Celular Tumoral , Molécula de Adhesión Celular Epitelial/metabolismo , Femenino , Ratones , Ratones Endogámicos C57BL , Microscopía Confocal , Mucina-1/metabolismo , Células Neoplásicas Circulantes/metabolismo , Puntos CuánticosRESUMEN
BACKGROUND: Injection of bulking agents into the anal canal is limited by several factors, including biological resorption, particle migration, and ongoing degradation of the injected bulking agent. OBJECTIVE: We investigated whether an injection of polycaprolactone beads containing autologous myoblasts could improve sphincter function in a dog model of fecal incontinence. DESIGN: The control sham surgery group underwent skin incision around the anal sphincter (n = 5). Fecal incontinence was induced by resecting 25% of the posterior internal/external anal sphincter in another 10 dogs. After 1 month of sphincter injury, dogs were then treated with (n = 5) or without (n = 5) polycaprolactone beads containing PKH-26-labeled autologous myoblasts. SETTING: This study was conducted at the department of surgery in collaboration with the department of advanced materials. OUTCOME MEASURES: Three months after injection treatment, the resting and contractile pressure differences of the anal sphincter were compared, and histopathological studies were performed. RESULTS: The anal pressures in untreated dogs were significantly lower than those in the sham surgery group (p < 0.05). The resting and contractile pressure differences were higher in treated dogs than in untreated dogs (resting pressure difference: 0.7 ± 0.5 vs -0.6 ± 0.8 mmHg; coefficient of the difference in recovery rate, 0.38; 95% CI, 0.15-0.61, p = 0.001; contractile pressure difference: 1.1 ± 4.2 vs -3.9 ± 2.6 mmHg; coefficient, 1.63; 95% CI, 0.55-2.71, p = 0.003). Immunofluorescent staining confirmed that the myoblasts had differentiated and synthesized myosin heavy chain, as observed in vitro. LIMITATIONS: This study was limited by the lack of comparison of injecting beads containing autologous myoblasts with injecting myoblasts alone. CONCLUSION: This study shows that an injection of polycaprolactone beads containing autologous myoblasts may improve anal sphincter function in an animal model of fecal incontinence.
Asunto(s)
Canal Anal/lesiones , Materiales Biocompatibles/uso terapéutico , Incontinencia Fecal/terapia , Contracción Muscular , Mioblastos Esqueléticos/trasplante , Poliésteres/uso terapéutico , Animales , Diferenciación Celular , Modelos Animales de Enfermedad , Perros , Técnica del Anticuerpo Fluorescente , Manometría , Mioblastos Esqueléticos/metabolismo , Cadenas Pesadas de Miosina/metabolismo , Trasplante Autólogo , Resultado del TratamientoRESUMEN
Bacillus cereus is a ubiquitous environmental microbe implicated as a main cause of food poisoning with various symptoms, depending on the strain type and the isolation source. In this study, the potential virulence factors and biochemical properties of B. cereus isolated from infant formulas and ready-to-eat (RTE) foods were analyzed and compared. A total of 347 B. cereus strains were isolated and identified from 687 infant food formulas and RTE food samples. All the isolates had one or more enterotoxin genes, and one-half of the strains had all 3 enterotoxin genes (hbl, nhe, and cytK) that are involved in food poisoning in humans. Here, all the 3 genes were detected in 50% of the B. cereus isolates from RTE foods and only 14% of the isolates were identified from infant formulas. The latter harbored low cytK and bceT, and very low hbl genes. Most B. cereus isolates possessed the hemolysis gene, but not the ces gene. The infant formula isolates showed stronger hemolysis activity than the other isolates. In addition, 26% of the total isolates showed low lecithinase activities and 10% showed high lecithinase activities. A greater number of isolates from the infant formula showed high lecithinase activity than those from the RTE foods. Approximately 83% of the isolates were positive and 17% were negative for starch hydrolysis. Over 90% of the RTE food isolates and only 35% of the infant formula isolates were positive for starch hydrolysis. However, all the strains possessed nhe, but their harboring patterns of hbl and cytK were significantly different. Most starch-hydrolyzing strains possessed hbl, but only 23% nonstarch-hydrolyzing isolates possessed this gene. Moreover, very low nonstarch hydrolyzing strains harbored cytK. Most nonstarch-hydrolyzing isolates showed high lecithinase and strong hemolysis activities, and very low hbl and cytK harboring. In summary, most infant formula isolates showed stronger hemolysis and higher lecithinase activities with lower frequency of harboring hbl and cytK and lower starch hydrolysis compared with RTE food isolates.
Asunto(s)
Bacillus cereus/fisiología , Enterotoxinas/toxicidad , Comida Rápida/microbiología , Fórmulas Infantiles/microbiología , Factores de Virulencia/toxicidad , Bacillus cereus/genética , Enterotoxinas/genética , Hemólisis , Humanos , Hidrólisis , Recién Nacido , Fosfolipasas/metabolismo , Almidón/metabolismo , Factores de Virulencia/genéticaRESUMEN
ETHNOPHARMACOLOGICAL RELEVANCE: Panax ginseng (P. ginseng) C.A. Meyer. Has been studied for decades for its various biological activities, especially in terms of immune-regulatory properties. Traditionally, it has been known that root, leaves, and fruits of P. ginseng were eaten for improving body's Qi and homeostasis. Also, these were used to protect body from various types of infectious diseases. However, molecular mechanisms of immunomodulatory activities of ginseng berries have not been systemically studied as often as other parts of the plant. AIM OF THE STUDY: The aim of this research is to discover the regulatory effects of P. ginseng berries, more importantly, their ginsenosides, on innate immune responses and to elucidate the molecular mechanism. MATERIALS AND METHODS: Ginseng berry concentrate (GBC) was orally injected into BALB/c mice for 30 days, and spleens were extracted for evaluation of immune-regulatory effects. Murine macrophage RAW264.7 cells were used for detailed molecular mechanism studies. Splenic natural killer (NK) cells were isolated using the magnetic-activated cell sorting (MACS) system, and the cytotoxic activity of isolated NK cells was measured using a lactate dehydrogenase (LDH) release assay. The splenic immune cell population was determined by flow-cytometry. NF-κB promoter activity was assessed by in vitro luciferase assay. Expression of inflammatory proteins and cytokines of the spleen and RAW264.7 cells were evaluated using western blotting and real-time PCR, respectively. RESULTS: The GBC enhanced cytotoxic activity of NK cells and the immune-regulation-related splenic cell population. Moreover, GBC promoted NF-κB promoter activity and stimulated the NF-κB signaling cascade. In spleen and RAW264.7 cells, expression of pro-inflammatory cytokines was increased upon GBC application, while expression of anti-inflammatory cytokines decreased. CONCLUSIONS: These results suggest that P. ginseng berry can stimulate innate immune responses and help maintain a balanced immune condition, mostly due to the action of its key ginsenoside Re, along with other protopanaxadiol- and protopanaxatriol-type ginsenosides. Such finding will provide a new insight into the field of well-being diet research as well as non-chemical immune modulator, by providing nature-derived and plant-based bioactive materials.