RESUMO
Osteoporosis is particularly prevalent among postmenopausal women and the elderly. In the present study, we investigated the effect of the novel small molecule E0924G (N-(4-methoxy-pyridine-2-yl)-5-methylfuran-2-formamide) on osteoporosis. E0924G significantly increased the protein expression levels of osteoprotegerin (OPG) and runt-related transcription factor 2 (RUNX2), and thus significantly promoted osteogenesis in MC3T3-E1 cells. E0924G also significantly decreased osteoclast differentiation and inhibited bone resorption and F-actin ring formation in receptor activator of NF-κB ligand (RANKL)-induced osteoclasts from RAW264.7 macrophages. Importantly, oral administration of E0924G in both ovariectomized (OVX) rats and SAMP6 senile mice significantly increased bone mineral density and decreased bone loss compared to OVX controls or SAMR1 mice. Further mechanistic studies showed that E0924G could bind to and then activate peroxisome proliferator-activated receptor delta (PPARδ), and the pro-osteoblast effect and the inhibition of osteoclast differentiation induced by E0924G were significantly abolished when PPARδ was knocked down or inhibited. In conclusion, these data strongly suggest that E0924G has the potential to prevent OVX-induced and age-related osteoporosis by dual regulation of bone formation and bone resorption through activation of the PPARδ signaling pathway.
Assuntos
Reabsorção Óssea , Osteogênese , Ovariectomia , PPAR delta , Transdução de Sinais , Animais , Camundongos , Reabsorção Óssea/tratamento farmacológico , Reabsorção Óssea/prevenção & controle , Reabsorção Óssea/metabolismo , Ratos , PPAR delta/metabolismo , Feminino , Osteogênese/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Relação Estrutura-Atividade , Estrutura Molecular , Células RAW 264.7 , Osteoporose/tratamento farmacológico , Osteoporose/prevenção & controle , Osteoporose/metabolismo , Relação Dose-Resposta a Droga , Bibliotecas de Moléculas Pequenas/farmacologia , Bibliotecas de Moléculas Pequenas/química , Ratos Sprague-Dawley , Osteoclastos/efeitos dos fármacos , Osteoclastos/metabolismo , Diferenciação Celular/efeitos dos fármacosRESUMO
Proprotein convertase subtilisin/kexin type 9 (PCSK9) binds to the epidermal growth factor precursor homologous domain A (EGF-A) of low-density lipoprotein receptor (LDLR) in the liver and triggers the degradation of LDLR via the lysosomal pathway, consequently leading to an elevation in plasma LDL-C levels. Inhibiting PCSK9 prolongs the lifespan of LDLR and maintains cholesterol homeostasis in the body. Thus, PCSK9 is an innovative pharmacological target for treating hypercholesterolemia and atherosclerosis. In this study, we discovered that E28362 was a novel small-molecule PCSK9 inhibitor by conducting a virtual screening of a library containing 40,000 compounds. E28362 (5, 10, 20 µM) dose-dependently increased the protein levels of LDLR in both total protein and the membrane fraction in both HepG2 and AML12 cells, and enhanced the uptake of DiI-LDL in AML12 cells. MTT assay showed that E28362 up to 80 µM had no obvious toxicity in HepG2, AML12, and HEK293a cells. The effects of E28362 on hyperlipidemia and atherosclerosis were evaluated in three different animal models. In high-fat diet-fed golden hamsters, administration of E28362 (6.7, 20, 60 mg·kg-1·d-1, i.g.) for 4 weeks significantly reduced plasma total cholesterol (TC), triglyceride (TG), low-density lipoprotein-cholesterol (LDL-C) and PCSK9 levels, and reduced liver TC and TG contents. In Western diet-fed ApoE-/- mice (20, 60 mg·kg-1·d-1, i.g.) and human PCSK9 D374Y overexpression mice (60 mg·kg-1·d-1, i.g.), administration of E28362 for 12 weeks significantly decreased plasma LDL-C levels and the area of atherosclerotic lesions in en face aortas and aortic roots. Moreover, E28362 significantly increased the protein expression level of LDLR in the liver. We revealed that E28362 selectively bound to PCSK9 in HepG2 and AML12 cells, blocked the interaction between LDLR and PCSK9, and induced the degradation of PCSK9 through the ubiquitin-proteasome pathway, which finally resulted in increased LDLR protein levels. In conclusion, E28362 can block the interaction between PCSK9 and LDLR, induce the degradation of PCSK9, increase LDLR protein levels, and alleviate hyperlipidemia and atherosclerosis in three distinct animal models, suggesting that E28362 is a promising lead compound for the treatment of hyperlipidemia and atherosclerosis.
RESUMO
Nonalcoholic fatty liver disease (NAFLD) is one of the most common liver diseases. Silencing information regulator 1 (SIRT1) was demonstrated to modulate cholesterol and lipid metabolism in NAFLD. Here, a novel SIRT1 activator, E1231, was studied for its potential improvement effects on NAFLD. C57BL/6J mice were fed a high-fat and high-cholesterol diet (HFHC) for 40 weeks to create a NAFLD mouse model, and E1231 was administered by oral gavage (50 mg/kg body weight, once/day) for 4 weeks. Liver-related plasma biochemistry parameter tests, Oil Red O staining, and hematoxylin-eosin staining results showed that E1231 treatment ameliorated plasma dyslipidemia, plasma marker levels of liver damage (alanine aminotransferase (ALT) and aspartate aminotransferase (AST)), liver total cholesterol (TC) and triglycerides (TG) contents, and obviously decreased hepatic steatosis score and NAFLD Activity Score (NAS) in the NAFLD mouse model. Western blot results showed that E1231 treatment significantly regulated lipid-metabolism-related protein expression. In particular, E1231 treatment increased SIRT1, PGC-1α, and p-AMPKα protein expression but decreased ACC and SCD-1 protein expression. Additionally, in vitro studies demonstrated that E1231 inhibited lipid accumulation and improved mitochondrial function in free-fatty-acid-challenged hepatocytes, and required SIRT1 activation. In conclusion, this study illustrated that the SIRT1 activator E1231 alleviated HFHC-induced NAFLD development and improved liver injury by regulating the SIRT1-AMPKα pathway, and might be a promising candidate compound for NAFLD treatment.
RESUMO
Krüppel-like factor 2 (KLF2) is an atherosclerotic protective transcription factor that maintains endothelial cell homeostasis through its anti-inflammatory, anti-oxidant, and antithrombotic properties. The aim of this study was to discover KLF2 activators from microbial secondary metabolites and explore their potential molecular mechanisms. By using a high-throughput screening model based on a KLF2 promoter luciferase reporter assay, column chromatography, electrospray ionization mass spectrometry (ESI-MS), and nuclear magnetic resonance (NMR) spectra, trichostatin D (TSD) was isolated from the rice fermentation of Streptomyces sp. CPCC203909 and identified as a novel KLF2 activator. Real-time-quantitative polymerase chain reaction (RT-qPCR) results showed that TSD upregulated the mRNA level of KLF2 in endothelial cells. Functional assays showed that TSD attenuated monocyte adhesion to endothelial cells, decreased vascular cell adhesion protein 1 (VCAM-1) and intercellular adhesion molecule 1 (ICAM-1) expression, and exhibited an anti-inflammatory effect in tumor necrosis factor alpha (TNFα)-induced endothelial cells. We further demonstrated through siRNA and western blot assays that the effects of TSD on monocyte adhesion and inflammation in endothelial cells were partly dependent on upregulating KLF2 expression and then inhibiting the NOD-like receptor protein 3 (NLRP3)/Caspase-1/interleukin-1beta (IL-1ß) signaling pathway. Furthermore, histone deacetylase (HDAC) overexpression and molecular docking analysis results showed that TSD upregulated KLF2 expression by inhibiting HDAC 4, 5, and 7 activities. Taken together, TSD was isolated from the fermentation of Streptomyces sp. CPCC203909 and first reported as a potential activator of KLF2 in this study. Furthermore, TSD upregulated KLF2 expression by inhibiting HDAC 4, 5, and 7 and attenuated endothelial inflammation via regulation of the KLF2/NLRP3/Caspase-1/IL-1ß signaling pathway.
Assuntos
Células Endoteliais , Fator de Necrose Tumoral alfa , Humanos , Fator de Necrose Tumoral alfa/farmacologia , Fator de Necrose Tumoral alfa/metabolismo , Células Endoteliais/metabolismo , Fatores de Transcrição Kruppel-Like/genética , Fatores de Transcrição Kruppel-Like/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Simulação de Acoplamento Molecular , Inflamação/patologia , Molécula 1 de Adesão de Célula Vascular/metabolismo , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/metabolismo , Caspases/metabolismoRESUMO
The OPG/RANKL/RANK pathway is a promising target for the design of therapeutic agents used in the treatment of osteoporosis. E09241 with an N-methylpyridine-chlorofuranformamide structural skeleton was previously identified to decrease bone loss and thus protect against osteoporosis in ovariectomized rats through increasing osteoprotegerin (OPG) expression. In this study, 36 derivatives of E09241 (3a) were prepared. The synthesis, up-regulation of OPG activities, SAR (structure-activity relationship), and cytotoxicity of these compounds are presented. Compounds with good up-regulating OPG activities could inhibit RANKL (the receptor activator of nuclear factor-kappa B ligand)-induced osteoclastogenesis in RAW264.7 cells. Particularly, compounds 3c and 3i1 significantly reduced NFATc1 and MMP-9 protein expression through inhibition of the NF-κB and MAPK pathways in RANKL induced RAW264.7 cells. In addition, compounds 3c and 3v significantly promoted osteoblast differentiation in MC3T3-E1 cells in osteogenic medium, and compounds 3c, 3v, and 3i1 obviously increased OPG protein expression and secretion in MC3T3-E1 cells. Furthermore, the pharmacokinetic profiles, acute toxicity, and hERG K+ channel effects of compounds 3a, 3c, 3e, 3v, and 3i1 were investigated. Taken together, these results indicate that N-methylpyridine-chlorofuranformamide analog 3i1 could serve as a promising lead for the development of new agents for treating osteoporosis.
Assuntos
Formamidas/farmacologia , Furanos/farmacologia , Osteoprotegerina/metabolismo , Piridinas/farmacologia , Ligante RANK/antagonistas & inibidores , Células 3T3 , Animais , Relação Dose-Resposta a Droga , Formamidas/química , Furanos/química , Camundongos , Estrutura Molecular , Osteogênese/efeitos dos fármacos , Piridinas/química , Ligante RANK/metabolismo , Células RAW 264.7 , Ratos , Ratos Sprague-Dawley , Relação Estrutura-AtividadeRESUMO
In this work, we isolated and characterized fusapyrone A (1), a new γ-pyrone derivative, along with six previously described compounds from the rice fermentation of Fusarium sp. CPCC 401218, a fungus collected from the desert. The structure of 1 was characterized using various spectroscopic analyses, such as MS, IR, 1D, and 2D NMR. The absolute configuration of 1 was determined through the use of 13C NMR chemical shifts, electronic circular dichroism (ECD) and optical rotation (OR) calculations. Compound 1 was found to have weak antiproliferative activity for Hela cells, with an IC50 of 50.6 µM.[Formula: see text].
Assuntos
Fusarium , Pironas , Células HeLa , Humanos , Estrutura Molecular , Pironas/farmacologiaRESUMO
Eight compounds were isolated from the rice fermentation of Streptomyces sp. CPCC 202950 by a combination of various chromatographic techniques including column chromatography over silica, Sephadex LH-20, flash C18, and reversed-phase HPLC. Their structures were identified as 3-[(3'-amino-3'-oxoprop-1'-en-2'-yl)oxy]benzamide (1), m-hydroxybenzamide (2), leptosphaepin (3), 5-methyluracil (4), feruloylamide (5), p-hydroxyphenylacetoamide (6), vanillamide (7), cyclo (L-val-L-ala) (8). Among them, 1 was a new benzamide analogue, and 2 was a new natural product. In the preliminary assays, none of the compounds 1-8 exhibited obvious inhibition of HIV-1 protease activity, and toxic with the Hela, HepG2, and U2OS cells. (IC50 > 10 µmolâ¢L⻹).
Assuntos
Benzamidas/isolamento & purificação , Fermentação , Streptomyces/química , Linhagem Celular Tumoral , Humanos , Estrutura Molecular , OryzaRESUMO
Four new trichostatin analogues (1-4) and six known analogues have been isolated from the rice fermentation of the Streptomyces sp. CPCC 203909. The structures and absolute configurations of these compounds were determined by extensive spectroscopic analysis including 2D NMR and electronic circular dichroism (ECD) calculations based on the quantum-mechanical time-dependent density functional theory (TDDFT). Compounds 2, 5-7, 9, and 10 up-regulated the transcriptional activity of human high density lipoprotein receptor (CLA-1) with EC50 values of 0.38-78.83µM.
Assuntos
Ácidos Hidroxâmicos/química , Streptomyces/química , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Dicroísmo Circular , Células HEK293 , Células HeLa , Células Hep G2 , Humanos , Ácidos Hidroxâmicos/isolamento & purificação , Ácidos Hidroxâmicos/farmacologia , Espectroscopia de Ressonância Magnética , Conformação Molecular , Teoria Quântica , Receptores de Lipoproteínas/genética , Receptores de Lipoproteínas/metabolismo , Streptomyces/metabolismo , Transcrição Gênica/efeitos dos fármacosRESUMO
A new trichostatin analog (1) and two known analogs (2, 3) have been isolated from the rice fermentation of the Streptomyces sp. CPCC 203909. Their structures were determined by spectroscopic and chemical methods. The absolute configurations of 1 were assigned by Marfey's method, combined with comparing the NMR and circular dichroism spectroscopic data of 2 and 3. Compound 1 showed cytotoxicity against human embryonic kidney 293 cell line with IC50 value of 39.2 µM.
Assuntos
Ácidos Hidroxâmicos/isolamento & purificação , Streptomyces/química , Fermentação , Humanos , Ácidos Hidroxâmicos/química , Concentração Inibidora 50 , Estrutura Molecular , Ressonância Magnética Nuclear BiomolecularRESUMO
By using a cell-based high throughput screening model for the CLA-1 up-regulator, Streptomyces 203909 was found to produce up-regulator of CLA-1. A novel trichostatin analogue was isolated from the rice fermentation of Streptomyces sp. CPCC 203909by a combination of various chromatographic techniques including column chromatography (CC) over silica gel, flash C18 CC, and reversed-phase HPLC. Its structure was identified as (-)-(R,2E,4Z)-7-[(4'-dimethylamino) phenyl]-4,6-dimethyl-7-oxohepta-2,4-dienoyl-L-glutamine (1) by the spectroscopic and chemical methods, and combination with the CD spectroscopy and Marfey's method. In the prelimi- nary assays, Compound 1 showed cytotoxicity against human embryonic kidney 293 cell line with IC50 value 35.3 [µmol · L(-1).
Assuntos
Ácidos Hidroxâmicos/química , Ácidos Hidroxâmicos/metabolismo , Streptomyces/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Fermentação , Células Hep G2 , Humanos , Ácidos Hidroxâmicos/isolamento & purificação , Ácidos Hidroxâmicos/farmacologia , Estrutura Molecular , Streptomyces/químicaRESUMO
Eleven compounds were isolated from the culture of Streptomyces sp. CPCC 202950 by a combination of various chromatographic techniques including column chromatography over macroporous resin HP-20, MCI, and reversed-phase HPLC. Their structures were identified as 1H-pyrrole-2-carboxamide(1),5'-deoxy-5'-methylthioinosine(2), vanillamide(3), trans-3-methylthioacrylamide(4), 1,2,3,4-Tetraydro-1H-pyrido[3,4-b]indole-3-carboxylic acid(5), cyclo(L-pro-L-tyr) (6), N-[2-(4-hydroxyphenyl)]ethylacetamide(7), benzamide (8), cyclo ('L-leucyl-trans-4-hydroxy-L-proline)(9), cyclo-(Phe-Gly) (10), and tryptophan (11). Among them, compounds 1 and 2 were new natural products. In the preliminary assays, none of the compounds exhibited obvious inhibition of HIV-1 protease activity (IC50 > 10 micromol x L(-1)).
Assuntos
Meios de Cultura/química , Streptomyces/química , Meios de Cultura/metabolismo , Protease de HIV/análise , Inibidores da Protease de HIV/química , Inibidores da Protease de HIV/isolamento & purificação , Estrutura Molecular , Espectrometria de Massas por Ionização por Electrospray , Streptomyces/metabolismoRESUMO
ABCA1 and scavenger receptor class B type I (SR-BI)/CD36 and lysosomal integral membrane protein II analogous 1 (CLA-1) are the key transporter and receptor in reverse cholesterol transport (RCT). Increasing the expression level of ABCA1 and SR-BI/CLA-1 is antiatherogenic. The aim of the study was to find novel antiatherosclerotic agents upregulating expression of ABCA1 and SR-BI/CLA-1 from natural compounds. Using the ABCA1p-LUC and CLA-1p-LUC HepG2 cell lines, we found that rutaecarpine (RUT) triggered promoters of ABCA1 and CLA-1 genes. RUT increased ABCA1 and SR-BI/CLA-1 expression in vitro related to liver X receptor alpha and liver X receptor beta. RUT induced cholesterol efflux in RAW264.7 cells. ApoE-deficient (ApoE(-/-)) mice treated with RUT for 8 weeks showed â¼68.43, 70.23, and 85.56% less en face lesions for RUT (L), RUT (M), and RUT (H) groups, respectively, compared with the model group. Mouse macrophage-specific antibody and filipin staining indicated that RUT attenuated macrophages and cholesterol accumulations in atherosclerotic lesions, respectively. Additionally, ABCA1 and SR-BI expression was highly induced by RUT in livers of ApoE(-/-) mice. Meanwhile, RUT treatment significantly increased the fecal (3)H-cholesterol excretion, which demonstrated that RUT could promote RCT in vivo. RUT was identified to be a candidate that protected ApoE(-/-) mice from developing atherosclerosis through preferentially promoting activities of ABCA1 and SR-BI within RCT.
Assuntos
Transportador 1 de Cassete de Ligação de ATP/biossíntese , Apolipoproteínas E/genética , Aterosclerose/prevenção & controle , Alcaloides Indólicos/farmacologia , Fígado/metabolismo , Quinazolinas/farmacologia , Receptores Depuradores Classe B/metabolismo , Transportador 1 de Cassete de Ligação de ATP/genética , Animais , Apolipoproteínas E/metabolismo , Aterosclerose/genética , Aterosclerose/metabolismo , Aterosclerose/patologia , Fígado/patologia , Camundongos , Camundongos Knockout , Células RAW 264.7 , Receptores Depuradores Classe B/genéticaRESUMO
OBJECTIVE: Type 2 diabetes mellitus (T2DM) is a common chronic metabolic disease. Peroxisome proliferator-activated receptors (PPARs) play crucial roles in regulating glucolipid metabolism. Previous studies showed that E17241 could ameliorate atherosclerosis and lower fasting blood glucose levels in ApoE-/- mice. In this work, we investigated the role of E17241 in glycolipid metabolism in diabetic KKAy mice. APPROACH AND RESULTS: We confirmed that E17241 is a powerful pan-PPAR agonist with a potent agonistic activity on PPARγ, a high activity on PPARα, and a moderate activity on PPARδ. E17241 also significantly increased the protein expression of ATP-binding cassette transporter 1 (ABCA1), a crucial downstream target gene for PPARs. E17241 clearly lowered plasma glucose levels, improved OGTT and ITT, decreased islet cholesterol content, improved ß-cell function, and promoted insulin secretion in KKAy mice. Moreover, E17241 could significantly lower plasma total cholesterol and triglyceride levels, reduce liver lipid deposition, and improve the adipocyte hypertrophy and the inflammatory response in epididymal white adipose tissue. Further mechanistic studies indicated that E17241 boosts cholesterol efflux and insulin secretion in an ABCA1 dependent manner. RNA-seq and qRT-PCR analysis demonstrated that E17241 induced different expression of PPAR target genes in liver and adipose tissue differently from the PPARγ agonist rosiglitazone. In addition, E17241 treatment was also demonstrated to have an exhilarating cardiorenal benefits. CONCLUSIONS: Our results demonstrate that E17241 regulates glucolipid metabolism in KKAy diabetic mice while having cardiorenal benefits without inducing weight gain. It is a promising drug candidate for the treatment of T2DM.
Assuntos
Diabetes Mellitus Experimental , Diabetes Mellitus Tipo 2 , Dislipidemias , Hiperglicemia , Camundongos , Animais , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/tratamento farmacológico , PPAR gama/metabolismo , Diabetes Mellitus Experimental/tratamento farmacológico , Hipoglicemiantes/farmacologia , Hipoglicemiantes/uso terapêutico , Dislipidemias/tratamento farmacológico , Fígado/metabolismo , Hiperglicemia/tratamento farmacológico , Colesterol/metabolismo , Tecido Adiposo Branco/metabolismoRESUMO
We have isolated an extraordinary pentapeptide, called 4862F, from the culture broth of Streptomyces albosporus I03A-04862 by Diaion HP-20 macroporous adsorbent resin column, ODS-A and Sephadex LH-20 chromatography, followed by preparative HPLC. This peptide shows inhibitory activity against HIV-1 protease. The structure was elucidated by spectroscopic approaches, including ESI-MS and various NMR methods. Absolute configuration of the amino acid residues in 4862F was defined using Marfey's method, and the structure was identified as N,N,N-(trimethylated)-Tyr-L-Leu-L-Val-L-Leu-(dehydrated)-His. The peptide 4862F displays inhibitory activity against HIV-1 protease, with IC50 values of 15.26 nM, using a fluorescence-based assay.
Assuntos
Inibidores da Protease de HIV/química , Inibidores da Protease de HIV/farmacologia , Oligopeptídeos/química , Oligopeptídeos/farmacologia , Peptídeos/química , Peptídeos/farmacologia , Streptomyces/metabolismo , Aminoácidos/análise , Cromatografia Líquida de Alta Pressão , Fermentação , Concentração Inibidora 50 , Espectroscopia de Ressonância Magnética , Estrutura MolecularRESUMO
ATP-binding cassette transporter A1 (ABCA1) promotes cholesterol and phospholipid efflux from cells to lipid-poor apolipoprotein A-I (apoA-I), and plays a key role in the initial steps of the whole process of reverse cholesterol transport (RCT). Upregulation of ABCA1 is beneficial for atherosclerosis (AS) prevention and/or therapy, which indicated that ABCA1 was a target for anti-AS drug development. In the previous study, a high-throughput screening method was established using ABCA1p-LUC HepG2 cell line to find the upregulators of ABCA1. In the present study, compound 2030421B was found using this method, with EC50 of 0.50 microg x mL(-1). The compound was further identified as an upregulator of ABCA1 expression by real-time quantitative reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting analysis. Studies also showed that the 2030421B could induce apoA-I-mediated cholesterol efflux and inhibit lipids uptake into mouse peritoneal macrophages RAW264.7.
Assuntos
Transportadores de Cassetes de Ligação de ATP/metabolismo , Anticolesterolemiantes/farmacologia , Apolipoproteína A-I/metabolismo , Benzaldeídos/farmacologia , Colesterol/metabolismo , Transportador 1 de Cassete de Ligação de ATP , Transportadores de Cassetes de Ligação de ATP/genética , Animais , Anticolesterolemiantes/administração & dosagem , Anticolesterolemiantes/química , Benzaldeídos/administração & dosagem , Benzaldeídos/química , Transporte Biológico , Células Cultivadas , Relação Dose-Resposta a Droga , Células Hep G2 , Ensaios de Triagem em Larga Escala , Humanos , Metabolismo dos Lipídeos , Lipídeos/análise , Macrófagos Peritoneais/citologia , Macrófagos Peritoneais/metabolismo , Camundongos , Estrutura Molecular , RNA Mensageiro , Regulação para Cima/efeitos dos fármacosRESUMO
Many microorganisms have mechanisms that protect cells against attack from viruses. The fermentation components of Streptomyces sp. 1647 exhibit potent anti-influenza A virus (IAV) activity. This strain was isolated from soil in southern China in the 1970s, but the chemical nature of its antiviral substance(s) has remained unknown until now. We used an integrated multi-omics strategy to identify the antiviral agents from this streptomycete. The antibiotics and Secondary Metabolite Analysis Shell (antiSMASH) analysis of its genome sequence revealed 38 biosynthetic gene clusters (BGCs) for secondary metabolites, and the target BGCs possibly responsible for the production of antiviral components were narrowed down to three BGCs by bioactivity-guided comparative transcriptomics analysis. Through bioinformatics analysis and genetic manipulation of the regulators and a biosynthetic gene, cluster 36 was identified as the BGC responsible for the biosynthesis of the antiviral compounds. Bioactivity-based molecular networking analysis of mass spectrometric data from different recombinant strains illustrated that the antiviral compounds were a class of structural analogues. Finally, 18 pseudo-tetrapeptides with an internal ureido linkage, omicsynins A1-A6, B1-B6, and C1-C6, were identified and/or isolated from fermentation broth. Among them, 11 compounds (omicsynins A1, A2, A6, B1-B3, B5, B6, C1, C2, and C6) are new compounds. Omicsynins B1-B4 exhibited potent antiviral activity against IAV with the 50% inhibitory concentration (IC50) of approximately 1 µmolâL-1 and a selectivity index (SI) ranging from 100 to 300. Omicsynins B1-B4 also showed significant antiviral activity against human coronavirus HCoV-229E. By integrating multi-omics data, we discovered a number of novel antiviral pseudo-tetrapeptides produced by Streptomyces sp. 1647, indicating that the secondary metabolites of microorganisms are a valuable source of novel antivirals.
RESUMO
ATP-binding cassette transporter A1 (ABCA1) promotes cholesterol and phospholipid efflux from cells to lipid-poor apolipoprotein A-I and plays an important role in atherosclerosis. In a previous study, we developed a high-throughput screening method using an ABCA1p-LUC HepG2 cell line to find upregulators of ABCA1. Using this method in the present study, we found that mycophenolic acid (MPA) upregulated ABCA1 expression (EC50=0.09 µM). MPA upregulation of ABCA1 expression was confirmed by real-time quantitative reverse transcription-PCR and Western blot analysis in HepG2 cells. Previous work has indicated that MPA is a potent agonist of peroxisome proliferator-activated receptor gamma (PPARγ; EC50=5.2-9.3 µM). Liver X receptor α (LXRα) is a target gene of PPARγ and may directly regulate ABCA1 expression. Western blot analysis showed that MPA induced LXRα protein expression in HepG2 cells. Addition of PPARγ antagonist GW9662 markedly inhibited MPA-induced ABCA1 and LXRα protein expression. These data suggest that MPA increased ABCA1 expression mainly through activation of PPARγ. Thus, the effects of MPA on upregulation of ABCA1 expression were due mainly to activation of the PPARγ-LXRα-ABCA1 signaling pathway. This is the first report that the antiatherosclerosis activity of MPA is due to this mechanism.
Assuntos
Transportadores de Cassetes de Ligação de ATP/fisiologia , Aterosclerose/metabolismo , Ácido Micofenólico/farmacologia , Receptores Nucleares Órfãos/metabolismo , PPAR gama/agonistas , Transportador 1 de Cassete de Ligação de ATP , Transportadores de Cassetes de Ligação de ATP/genética , Anilidas/farmacologia , Animais , Linhagem Celular Tumoral , Células Espumosas/efeitos dos fármacos , Células Espumosas/metabolismo , Ensaios de Triagem em Larga Escala , Humanos , Receptores X do Fígado , PPAR gama/antagonistas & inibidores , PPAR gama/metabolismo , Ratos , Transcrição Gênica/efeitos dos fármacosRESUMO
Ahmpatinin iBu (1) and statinin iBu (2), two new linear peptides, a novel pyrrolidine derivative, (-)-(S)-2-[3-(6-methylheptanamido)-2-oxopyrrolidin-1-yl] acetic acid (3), and three known pepstatin derivatives (4-6) along with their corresponding methanolysis artifacts (7-9) were isolated from Streptomyces sp. CPCC 202950. Their structures were elucidated on the basis of extensive spectroscopic data using Marfey's analysis, chiral-phase HPLC, and ECD and OR calculation to determine the absolute configurations. Compound 1 contains an unusual amino acid, 4-amino-3-hydroxy-5-(4-methoxyphenyl)pentanoic acid (Ahmppa), and 3 is the first natural product with a 2-(3-amino-2-oxopyrrolidin-1-yl)acetic acid system. Compounds 1, 2, and 4-9 are HIV-1 protease inhibitors. In particular, ahmpatinin iBu (1) exhibits significant inhibitory activity against HIV-1 protease with an IC50 value of 1.79 nM. A preliminary structure-activity relationship is discussed.
RESUMO
CD36, a member of the class B scavenger receptor, is a high-affinity receptor for oxidatively modified low-density lipoprotein (oxLDL). Extensive evidence points to a significant role of CD36 in atherosclerosis and suggests that CD36 could be a potential target for treatment of atherosclerosis. Here, the extracellular domain of human CD36 (Gly(30)-Asn(439)) was expressed in Escherichia coli as His(6)-tagged soluble CD36 (sCD36), which could bind oxLDL specifically and effectively inhibit the uptake of oxLDL by murine macrophage RAW 264.7 cells. An enzyme-linked immunosorbent assay (ELISA)-like high-throughput screening (HTS) assay was developed for the discovery of CD36 antagonists, based on the competition of sCD36 binding to immobilized oxLDL and detection with a monoclonal antibody against His-tag. This assay was suitable for HTS in a 96-well format and was robust and reliable according to the evaluation parameter Z' value of 0.82. The developed HTS assay was applied to both pure chemical compounds and microbial secondary metabolite crude extracts to identify CD36 antagonists. Three active compounds-sodium danshensu (DSS), rosmarinic acid (RA), and salvianolic acid B (SAB)-were shown to be antagonistic to sCD36-oxLDL binding and further validated by their inhibition of oxLDL uptake in RAW 264.7 cells. These results suggest that the ELISA-like assay represents a promising screening for identifying bioactive molecules targeting atherosclerosis at the level of CD36-ligand binding.