RESUMEN
Eighteen new oleanane-type triterpenoids were isolated from the stems of Sabia limoniacea, including sabialimon A (1), a triterpenoid with an unprecedented 6/6/6/7/7 pentacyclic skeleton and seventeen undescribed triterpenoids, sabialimons B-R (2 - 18), along with six previously described analogs (19 - 24). Their structures were fully elucidated via extensive spectroscopic analysis including 1D and 2D NMR, high-resolution electrospray ionization mass spectrometry (HRESIMS), experimental electronic circular dichroism measurements and X-ray crystallographic studies. Compound 1 is the first triterpenoid that possesses a rare ring system (6/6/6/7/7) with an oxygen-bearing bridge between C-17 and C-18 and a hemiketal form at C-17, which is generated a larger ring by the degradation of C-28 and D/E-ring expansion. Biological evaluation revealed that sabialimon I (9), sabialimon K (11), sabialimon P (16) and 11,13(18)-oleanadien-28-hydroxymethyl 3-one (20) exhibited significantly inhibitory activities against nitric oxide (NO) release with IC50 values of 29.65, 23.41, 18.12 and 26.64 µM, respectively, as compared with the positive control (dexamethasone, IC50 value: 40.35 µM). Furthermore, sabialimon P markedly decreased the secretion of TNF-α, iNOS, IL-6 and NF-κB and inhibited the expression of COX-2 and NF-κB/p65 in LPS-induced RAW264.7 cells in a dose-dependent manner.
RESUMEN
With the emergence of drug-resistant strains, the treatment of tuberculosis (TB) is becoming more difficult and there is an urgent need to find new anti-TB drugs. Mycobacterium marinum, as a model organism of Mycobacterium tuberculosis, can be used for the rapid and efficient screening of bioactive compounds. The 14-membered resorcylic acid lactones (RALs) have a wide range of bioactivities such as antibacterial, antifouling and antimalarial activity. In order to further study their bioactivities, we initially constructed a 14-membered RALs library, which contains 16 new derivatives. The anti-M. marinum activity was evaluated in vitro. Derivatives 12, 19, 20 and 22 exhibited promising activity with MIC90 values of 80, 90, 80 and 80 µM, respectively. The preliminary structure-activity relationships showed that the presence of a chlorine atom at C-5 was a key factor to improve activity. Further studies showed that 12 markedly inhibited the survival of M. marinum and significantly reduced the dosage of positive drugs isoniazid and rifampicin when combined with them. These results suggest that 12 is a bioactive compound capable of enhancing the potency of existing positive drugs, and its effective properties make it a very useful leads for future drug development in combating TB resistance.
Asunto(s)
Antimaláricos , Mycobacterium marinum , Anticuerpos , Antituberculosos , LactonasRESUMEN
Owing to the emergence of drug resistance and high morbidity and mortality, the need for novel anti-influenza A virus (IAV) drugs with divergent targets is highly sought after. Herein, a novel quinolone alkaloid (QLA) derived from marine fungus was discovered with broad-spectrum anti-IAV activities with low toxicity. Distinct from current anti-IAV drugs, QLA may block virus replication and viral RNA (vRNA) export from the nucleus by targeting virus nucleoprotein (NP). QLA can block the binding of chromosome region maintenance 1 to nuclear export signal 3 of NP to inhibit the nuclear export of NP and vRNP. QLA may also affect vRNP assembly by interfering with the binding of NP to RNA rather than NP oligomerization. Arg305 and Phe488-Gly490 may be required for the interaction between QLA and NP, and the binding pocket around these amino acids may be a promising target for anti-IAV drugs. Importantly, oral administration of QLA can protect the mice against IAV-induced death and weight loss, superior to the effects of the clinical drug oseltamivir. In summary, the marine derived compound QLA has the potential to be developed into a novel anti-IAV agent targeting virus NP protein in the future.
Asunto(s)
Alcaloides , Virus de la Influenza A , Quinolonas , Replicación Viral , Animales , Ratones , Alcaloides/farmacología , Virus de la Influenza A/efectos de los fármacos , Virus de la Influenza A/fisiología , Nucleoproteínas , Quinolonas/farmacología , Proteínas del Núcleo Viral/metabolismo , Replicación Viral/efectos de los fármacosRESUMEN
Daptomycin is a new lipopeptide antibiotic for treatment of severe infection caused by multi-drug-resistant bacteria, but its production cost remains high currently. Thus, it is very important to improve the fermentation ability of the daptomycin producer Streptomyces roseosporus. Here, we found that the deletion of proteasome in S. roseosporus would result in the loss of ability to produce daptomycin. Therefore, transcriptome and 4D label-free proteome analyses of the proteasome mutant (Δprc) and wild type were carried out, showing 457 differential genes. Further, five genes were screened by integrated crotonylation omics analysis. Among them, two genes (orf04750/orf05959) could significantly promote the daptomycin synthesis by overexpression, and the fermentation yield in shake flask increased by 54% and 76.7%, respectively. By enhancing the crotonylation modification via lysine site mutation (K-Q), the daptomycin production in shake flask was finally increased by 98.8% and 206.3%, respectively. This result proved that the crotonylation modification of appropriate proteins could effectively modulate daptomycin biosynthesis. In summary, we established a novel strategy of gene screen for antibiotic biosynthesis process, which is more convenient than the previous screening method based on pathway-specific regulators. KEY POINTS: ⢠Δprc strain has lost the ability of daptomycin production ⢠Five genes were screened by multi-omics analysis ⢠Two genes (orf04750/orf05959) could promote the daptomycin synthesis by overexpression.
Asunto(s)
Daptomicina , Streptomyces , Antibacterianos/farmacología , Complejo de la Endopetidasa Proteasomal , Proteoma/metabolismo , Streptomyces/metabolismoRESUMEN
Under the guidance of MS/MS-based molecular networking and HPLC-UV, two new alkaloid racemates, (±)-17-hydroxybrevianamide N (1) and (±)-N1-methyl-17-hydroxybrevianamide N (2), featuring a rare o-hydroxyphenylalanine residue and an imide subunit, were isolated from a soft-coral-derived Aspergillus sp. fungus. The true natural products (+)-1 and (+)-2 were further monitored and obtained from the freshly prepared EtOAc extracts, while (-)-1 and (-)-2 are artifacts generated during extraction and purification processes. Simultaneously, the structures including absolute configurations of (+)-13S-1, (-)-13R-1, (+)-13S-2, and (-)-13R-2 were elucidated on the basis of comprehensive spectroscopic analysis, ECD calculations, and X-ray diffraction data. Interestingly, basic solution promotes the racemization of (+)-1 and (-)-1, whereas acidic solution suppresses the transformation. The current research was concerned with the true natural products and their artifacts, providing critical insight into the isolation and identification of natural products.
Asunto(s)
Alcaloides/química , Aspergillus/química , Quinazolinonas/química , Alcaloides/aislamiento & purificación , Animales , Antozoos/microbiología , Productos Biológicos/química , Productos Biológicos/aislamiento & purificación , China , Estructura Molecular , Quinazolinonas/aislamiento & purificación , EstereoisomerismoRESUMEN
Under the guidance of MS/MS-based molecular networking, four new cycloheptapeptides, namely, asperheptatides A-D (1-4), were isolated together with three known analogues, asperversiamide A-C (5-7), from the coral-derived fungus Aspergillus versicolor. The planar structures of the two major compounds, asperheptatides A and B (1 and 2), were determined by comprehensive spectroscopic data analysis. The absolute configurations of the amino acid residues were determined by advanced Marfey's method. The two structurally related trace metabolites, asperheptatides C and D (3 and 4), were characterized by ESI-MS/MS fragmentation methods. A series of new derivatives (8-26) of asperversiamide A (5) were semisynthesized. The antitubercular activities of 1, 2, and 5-26 against Mycobacterium tuberculosis H37Ra were also evaluated. Compounds 9, 13, 23, and 24 showed moderate activities with MIC values of 12.5 µM, representing a potential new class of antitubercular agents.
Asunto(s)
Agaricales/química , Antozoos/microbiología , Antituberculosos/química , Aspergillus/química , Cinamatos/química , Mycobacterium tuberculosis/química , Péptidos Cíclicos/química , Animales , Cromatografía Liquida , Cinamatos/farmacología , Estructura Molecular , Péptidos Cíclicos/metabolismo , Análisis Espectral , Espectrometría de Masas en TándemRESUMEN
A small library of 120 compounds was established with seventy new alkylated derivatives of the natural product terphenyllin, together with 45 previous reported derivatives and four natural p-terphenyl analogs. The 70 new derivatives were semi-synthesized and evaluated for cytotoxic activities against four cancer cell lines. Interestingly, 2',4''-diethoxyterphenyllin, 2',4,4''-triisopropoxyterphenyllin, and 2',4''-bis(cyclopentyloxy)terphenyllin showed potent activities with IC50 values in a range from 0.13 to 5.51â µM, which were similar to those of the positive control, adriamycin. The preliminary structure-activity relationships indicated that the introduction of alkyl substituents including ethyl, allyl, propargyl, isopropyl, bromopropyl, isopentenyl, cyclopropylmethyl, and cyclopentylmethyl are important for improving the cytotoxicity.
Asunto(s)
Antineoplásicos/farmacología , Productos Biológicos/farmacología , Bibliotecas de Moléculas Pequeñas/química , Compuestos de Terfenilo/farmacología , Antineoplásicos/síntesis química , Antineoplásicos/química , Aspergillus/química , Aspergillus/aislamiento & purificación , Productos Biológicos/síntesis química , Productos Biológicos/química , Ciclo Celular/efectos de los fármacos , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Ensayos de Selección de Medicamentos Antitumorales , Humanos , Estructura Molecular , Relación Estructura-Actividad , Compuestos de Terfenilo/síntesis química , Compuestos de Terfenilo/químicaRESUMEN
BACKGROUND: Anthurium andraeanum, an important ornamental flower, has to go through a growth-delaying period after transfer from tissue culture to soil, which requires time and extra costs. Furthermore, during this period, the plantlets are highly susceptible to bacterial infections, which results in impaired development and severe losses. Here, we aimed to address whether application of the endophytic fungus, Piriformospora indica protects the A. andraeanum root system during the critical propagation period, and whether P. indica reduce the mortality rate by stimulating the host's resistance against diseases. RESULTS: We demonstrate that P. indica shortens the recovery period of Anthurium, promotes growth and confers disease resistance. The beneficial effect of P. indica results in faster elongation of Anthurium roots early in the interaction. P. indica-colonized plants absorb more phosphorus and exhibit higher photosynthesis rates than uncolonized control plants. Moreover, higher activities of stress-related enzymes, of jasmonic acid levels and mRNA levels of jasmonic acid-responsive genes suggest that the fungus prepares the plant to respond more efficiently to potentially upcoming threats, including bacterial wilt. CONCLUSION: These results suggest that P. indica is a helpful symbiont for promoting Anthurium rooting and development. All our evidences are sufficient to support the disease resistance conferred by P. indica through the plant-fungal symbiosis. Furthermore, it implicates that P. indica has strong potential as bio-fertilizer for utilization in ornamental plant cultivation.
Asunto(s)
Araceae/inmunología , Basidiomycota/fisiología , Endófitos/fisiología , Araceae/crecimiento & desarrollo , Araceae/microbiología , Resistencia a la Enfermedad , Raíces de Plantas/microbiologíaRESUMEN
Three new diketopiperazine alkaloids, including two oxepine-containing diketopiperazines, chrysopiperazines A and B (1 and 2), and one quinazoline-containing diketopiperazine, chrysopiperazine C (5), together with three known analogues (3, 4, and 6), were isolated from the gorgonian-derived Penicillium chrysogenum fungus. The relative and absolute configurations of C-3 and C-15 in 1 and 2, C-3 and C-14 in 5 were established by NOE modified Marfey's analysis and electronic circular dichroism (ECD) calculations. Particularly, the absolute configurations of C-19 in 1 and 3, which was very challenging to be identified due to the flexible conformation in a short aliphatic chain, were successfully determined by the vibrational circular dichroism (VCD) method, supplying with a reliable and optional method to define the absolute configurations. Additionally, this is the first report on oxepine-containing diketopiperazines from the genus Penicillium.
Asunto(s)
Alcaloides/química , Antozoos/microbiología , Dicetopiperazinas/química , Penicillium chrysogenum/química , Alcaloides/aislamiento & purificación , Alcaloides/farmacología , Animales , Antibacterianos/química , Antibacterianos/aislamiento & purificación , Antibacterianos/farmacología , Antifúngicos/química , Antifúngicos/aislamiento & purificación , Antifúngicos/farmacología , Bacterias/efectos de los fármacos , Dicroismo Circular , Dicetopiperazinas/aislamiento & purificación , Dicetopiperazinas/farmacología , Hongos/efectos de los fármacos , Pruebas de Sensibilidad Microbiana , Conformación Molecular , Estructura Molecular , Espectroscopía de Protones por Resonancia MagnéticaRESUMEN
BACKGROUND: Low-molecular-weight chitosan oligosaccharide (LMCOS), a chitosan degradation product, is water-soluble and easily absorbable, rendering it a popular biomaterial to study. However, its effect on bone remodelling remains unknown. Therefore, we evaluated the effect of LMCOS on lipopolysaccharide (LPS)-induced bone resorption in mice. METHODS: Six-week-old male C57BL/6 mice (n = five per group) were randomly divided into five groups: PBS, LPS, LPS + 0.005% LMCOS, LPS + 0.05% LMCOS, and LPS + 0.5% LMCOS. Then, the corresponding reagents (300 µL) were injected into the skull of the mice. To induce bone resorption, LPS was administered at 10 mg/kg per injection. The mice were injected three times a week with PBS alone or LPS without or with LMCOS and sacrificed 2 weeks later. The skull was removed for micro-computed tomography, haematoxylin-eosin staining, and tartrate-resistant acid phosphatase staining. The area of bone damage and osteoclast formation were evaluated and recorded. RESULTS: LMCOS treatment during LPS-induced skull resorption led to a notable reduction in the area of bone destruction; we observed a dose-dependent decrease in the area of bone destruction and number of osteoclasts with increasing LMCOS concentration. CONCLUSIONS: Our findings showed that LMCOS could inhibit skull bone damage induced by LPS in mice, further research to investigate its therapeutic potential for treating osteolytic diseases is required.
Asunto(s)
Resorción Ósea , Quitosano , Animales , Resorción Ósea/tratamiento farmacológico , Quitosano/farmacología , Lipopolisacáridos/toxicidad , Masculino , Ratones , Ratones Endogámicos C57BL , Oligosacáridos , Osteoclastos , Cráneo/efectos de los fármacos , Cráneo/patología , Microtomografía por Rayos XRESUMEN
One new hydroanthraquinone dimer with a rare C-9-C-7' linkage, nigrodiquinone A (1), and four known anthraquinone monomers 2-5, were isolated from a fungus Nigrospora sp. obtained from the zoanthid Palythoa haddoni collected in the South China Sea. The structure of 1 was established through extensive NMR spectroscopy, and the absolute configuration was elucidated by comparing computed electronic circular dichroism (ECD) and optical rotations (OR) with experimental results. All the compounds were evaluated for antiviral activity, and 1 was also evaluated for antibacterial activity. Compound 4 displayed mild antiviral activity against coxsackie virus (Cox-B3) with the IC50 value of 93.7 µM, and 5 showed an IC50 value of 74.0 µM against respiratory syncytial virus (RSV).
Asunto(s)
Antraquinonas/aislamiento & purificación , Antibacterianos/aislamiento & purificación , Antivirales/aislamiento & purificación , Ascomicetos/química , Antraquinonas/química , Antraquinonas/farmacología , Antibacterianos/química , Antibacterianos/farmacología , Antivirales/química , Antivirales/farmacología , China , Dicroismo Circular , Concentración 50 Inhibidora , Espectroscopía de Resonancia Magnética , Océanos y Mares , Rotación ÓpticaRESUMEN
Heterotrimeric GTP-binding protein (G-protein)-mediated abscisic acid (ABA) and drought-stress responses have been documented in numerous plant species. However, our understanding of the function of rice G-protein subunits in ABA signalling and drought tolerance is limited. In this study, the function of G-protein subunits in ABA response and drought resistance in rice plants was explored. It was found that the transcription level of qPE9-1 (rice Gγ subunit) gradually decreased with increasing ABA concentration and the lack of qPE9-1 showed an enhanced drought tolerance in rice plants. In contrast, mRNA levels of RGB1 (rice Gß subunit) were significantly upregulated by ABA treatment and the lack of RGB1 led to reduced drought tolerance. Furthermore, the results suggested that qPE9-1 negatively regulates the ABA response by suppressing the expression of key transcription factors involved in ABA and stress responses, while RGB1 positively regulates ABA biosynthesis by upregulating NCED gene expression under both normal and drought stress conditions. Taken together, it is proposed that RGB1 is a positive regulator of the ABA response and drought adaption in rice plants, whereas qPE9-1 is modulated by RGB1 and functions as a negative regulator in the ABA-dependent drought-stress responses.
Asunto(s)
Ácido Abscísico/metabolismo , Aclimatación , Proteínas de Unión al GTP/genética , Regulación de la Expresión Génica de las Plantas , Oryza/genética , Proteínas de Plantas/genética , Sequías , Proteínas de Unión al GTP/metabolismo , Oryza/metabolismo , Proteínas de Plantas/metabolismo , Plantas Modificadas Genéticamente/genética , Plantas Modificadas Genéticamente/metabolismo , Transducción de SeñalRESUMEN
Effects of a phosphorus-solubilizing bacteria (PSB) Bacillus megatherium on growth and lipid production of Chlorella sorokiniana were investigated in synthesized swine wastewater with dissolved inorganic phosphorus (DIP), insoluble inorganic phosphorus (IIP), and organic phosphorus (OP). The results showed that the PSB significantly promoted the algal growth in OP and IIP, by 1.10 and 1.78-fold, respectively. The algal lipid accumulation was also greatly triggered, respectively by 4.39, 1.68, and 1.38-fold in DIP, IIP, and OP. Moreover, compared with DIP, OP improved the oxidation stability of algal lipid by increasing the proportion of saturated fatty acids (43.8 % vs 27.9 %), while the PSB tended to adjust it to moderate ranges (30.2-41.6 %). Further, the transcriptome analysis verified the OP and/or PSB-induced up-regulated genes involving photosynthesis, lipid metabolism, signal transduction, etc. This study provided novel insights to enhance microalgae-based nutrient removal combined with biofuel production in practical wastewater, especially with complex forms of phosphorus.
Asunto(s)
Chlorella , Lípidos , Fosfatos , Aguas Residuales , Aguas Residuales/microbiología , Animales , Chlorella/metabolismo , Chlorella/crecimiento & desarrollo , Porcinos , Fosfatos/metabolismo , Lípidos/biosíntesis , Fósforo/metabolismo , Metabolismo de los Lípidos , Solubilidad , Bacillus/metabolismoRESUMEN
OBJECTIVE: To analyze the complications of laparoscopic surgery for the past 11 years in the Urology Department of Peking Union Medical College Hospital. METHODS: The laparoscopic surgery of 5 386 cases from Jan. 2002 to Dec. 2012 was statistically analyzed. The patient's gender, age, surgery mode, blood loss, complications, total length of hospital stay, postoperative hospital stay and other data were analyzed. RESULTS: There were 5 386 cases in this group aged 8-86 years (the mean age: 49.0 years; 2 651 cases were male and 2 735 female). Of all the cases, 2 411 were of adrenal surgery, accounting for 44.7%, 167 of retroperitoneal tumor resection , accounting for 3.1%, 763 of radical nephrectomy surgery, accounting for 14.2%, 441 of partial nephrectomy surgery, accounting for 8.2%, 784 of renal cyst surgery, accounting for 14.6%; 279 of semi-urinary tract resection, accounting for 5.2%; 74 of renal pelvis and ureter plasty, accounting for 1.4%; 141 of radical prostatectomy surgery, accounting for 2.6%, 71 of cystectomy surgery, accounting for 1.3% and 255 of other surgery, accounting for 4.7%. The blood loss was 10-3 000 mL (average: 97.5 mL ) and the surgery requiring blood transfusion treatment involved 270 patients. The total hospital stay was 3-133 days (average: 18 days) and postoperative hospital stay was 2-35 days (average: 6.3 days). All kinds of complications occured in 346 cases (6.42%), of which 198 were of peritoneal injury, 12 of pleural injury; 72 of subcutaneous emphysema, 24 of urinary fistula, 15 of inferior vena cava injury, 6 of pancreatic fistula 10,of lymphatic fistula, 8 of wound delayed healing and 1 of, intestinal fistula. The incidence of the complications and blood transfusion showed a downward trend according to stratified analysis each year. CONCLUSION: The laparoscopic surgery coveres almost all treatment of urological diseases. The complications are different in different types of surgery at different times, but generally no serious complications occurr. The incidence of complications is in a downward trend as the laparoscopic technique level improves.
Asunto(s)
Laparoscopía/efectos adversos , Complicaciones Posoperatorias/epidemiología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Niño , Cistectomía/efectos adversos , Femenino , Humanos , Incidencia , Enfermedades Renales Quísticas/cirugía , Neoplasias Renales/cirugía , Pelvis Renal/cirugía , Tiempo de Internación , Masculino , Persona de Mediana Edad , Nefrectomía/efectos adversos , Prostatectomía/efectos adversos , Uréter/cirugía , Adulto JovenRESUMEN
OBJECTIVE: To explore the diagnosis and treatment of tuberous sclerosis complex complicated with renal angiomyolipoma. METHODS: The clinical data of 22 patients with tuberous sclerosis complex complicated with renal angiomyolipoma were analyzed retrospectively. RESULTS: There were 12 males and 10 females with a mean age of 23 (1-46) years. All of them had bilateral multiple renal angiomyolipomas. The mean tumor size was 8.5 (0.7-18.0) cm in diameter. The presence or absence of clinical symptoms showed a significant correlation with tumor size.Eight patients with angiomyolipoma under 4 cm in diameter were continuously monitored at an outpatient clinic. There were 8 patients with lesions of 4-10 cm.Five of them underwent nephron-sparing surgeries and another 3 monitored at an outpatient clinic. There were 6 patients with tumor over 10 cm. Three of them underwent transcatheter arterial embolization and one case took rapamycin after embolization.One patient with concurrent renal cell carcinoma underwent partial nephrectomy. Chronic renal failure occurred in one case dying of pulmonary lymphangiomyomatosis with serious hemoptysis. During a mean follow-up of 25 months, neither severe renal hemorrhage nor symptomatic aggravation was found.In the case of rapamycin, there was 10% reduction in the size of angiomyolipoma. CONCLUSIONS: Most cases of tuberous sclerosis complex are complicated with bilateral multiple renal angiomyolipoma. The small lesions under 4 cm in diameter may be monitored at an outpatient clinic.For those larger (>4 cm) or symptomatic ones, medication, embolization or surgery is necessary.
Asunto(s)
Angiomiolipoma/complicaciones , Neoplasias Renales/complicaciones , Esclerosis Tuberosa/complicaciones , Adolescente , Adulto , Angiomiolipoma/diagnóstico , Angiomiolipoma/terapia , Niño , Preescolar , Femenino , Humanos , Lactante , Neoplasias Renales/diagnóstico , Neoplasias Renales/terapia , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Esclerosis Tuberosa/diagnóstico , Esclerosis Tuberosa/terapia , Adulto JovenRESUMEN
The efficiency of drug biosynthesis depends on different transcriptional regulatory pathways in Streptomyces, and the protein degradation system adds another layer of complexity to the regulatory processes. AtrA, a transcriptional regulator in the A-factor regulatory cascade, stimulates the production of daptomycin by binding to the dptE promoter in Streptomyces roseosporus. Using pull-down assays, bacterial two-hybrid system and knockout verification, we demonstrated that AtrA is a substrate for ClpP protease. Furthermore, we showed that ClpX is necessary for AtrA recognition and subsequent degradation. Bioinformatics analysis, truncating mutation, and overexpression proved that the AAA motifs of AtrA were essential for initial recognition in the degradation process. Finally, overexpression of mutated atrA (AAA-QQQ) in S. roseosporus increased the yield of daptomycin by 225% in shake flask and by 164% in the 15 L bioreactor. Thus, improving the stability of key regulators is an effective method to promote the ability of antibiotic synthesis.
Asunto(s)
Daptomicina , Streptomyces , Daptomicina/metabolismo , Antibacterianos/metabolismo , Regiones Promotoras Genéticas , Mutación , Tretinoina/metabolismo , Streptomyces/genética , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismoRESUMEN
DNA methylation is a defense that microorganisms use against extreme environmental stress, and improving resistance against environmental stress is essential for industrial actinomycetes. However, research on strain optimization utilizing DNA methylation for breakthroughs is rare. Based on DNA methylome analysis and KEGG pathway assignment in Streptomyces roseosporus, we discovered an environmental stress resistance regulator, TagR. A series of in vivo and in vitro experiments identified TagR as a negative regulator, and it is the first reported regulator of the wall teichoic acid (WTA) ABC transport system. Further study showed that TagR had a positive self-regulatory loop and m4C methylation in the promoter improved its expression. The ΔtagR mutant exhibited better hyperosmotic resistance and higher decanoic acid tolerance than the wild type, which led to a 100% increase in the yield of daptomycin. Moreover, enhancing the expression of the WTA transporter resulted in better osmotic stress resistance in Streptomyces lividans TK24, indicating the potential for wide application of the TagR-WTA transporter regulatory pathway. This research confirmed the feasibility and effectiveness of mining regulators of environmental stress resistance based on the DNA methylome, characterized the mechanism of TagR, and improved the resistance and daptomycin yield of strains. Furthermore, this research provides a new perspective on the optimization of industrial actinomycetes. IMPORTANCE This study established a novel strategy for screening regulators of environmental stress resistance based on the DNA methylome and discovered a new regulator, TagR. The TagR-WTA transporter regulatory pathway improved the resistance and antibiotic yield of strains and has the potential for wide application. Our research provides a new perspective on the optimization and reconstruction of industrial actinomycetes.
Asunto(s)
Daptomicina , Streptomyces , Epigenoma , Antibacterianos , Streptomyces/genética , Streptomyces/metabolismo , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismoRESUMEN
Further insights on the secondary metabolites of a soft coral-derived fungus Aspergillus versicolor under the guidance of MS/MS-based molecular networking led to the isolation of seven known cycloheptapeptides, namely, asperversiamides A-C (1-3) and asperheptatides A-D (4-7) and an unusual pyrroloindoline-containing new cycloheptapeptide, asperpyrroindotide A (8). The structure of 8 was elucidated by comprehensive spectroscopic data analysis, and its absolute configuration was determined by advanced Marfey's method. The semisynthetic transformation of 1 into 8 was successfully achieved and the reaction conditions were optimized. Additionally, a series of new derivatives (10-19) of asperversiamide A (1) was semi-synthesized and their anti-tubercular activities were evaluated against Mycobacterium tuberculosis H37Ra. The preliminary structure-activity relationships revealed that the serine hydroxy groups and the tryptophan residue are important to the activity. Supplementary Information: The online version contains supplementary material available at 10.1007/s42995-022-00157-8.
RESUMEN
OBJECTIVE: To investigate the role of the lncRNA MEG3 (MEG3) in opposing the biochemical processes thought to be involved in the development of atherosclerosis (AS). METHODS: Thirty patients with AS and thirty healthy control subjects were enrolled in this study. The expression of MEG3, miR-200b-3p and ABCA1 was analyzed by RT-qPCR in the individuals and the macrophages-derived foam cells. Lipid accumulation was detected by oil red O staining. Cholesterol efflux was measured by ELISA assay in the foam cells. Expression of miR-200b-3p was identified by sequencing. Targeting relationships were determined by dual luciferase assay between MEG3 and miR-200b-3p, miR-200b-3p and ABCA1. RESULTS: In the patients with AS, MEG3 and ABCA1 expression were decreased and miR-200b-3p expression was upregulated. Foam cells transfected with an expression vector (pcDNA3.1) containing MEG3 (pcDNA3.1-MEG3) induced decrease of lipid accumulation and increase of cholesterol efflux compared to cells transfected with control plasmid alone. Foam cells transfected by pcDNA3.1-MEG3 also showed decreased miR-200b-3p and increased ABCA1 expression. Interestingly, co-expression of miR-200b-3p partially prevented these effects of MEG3 expression. CONCLUSION: Expression of MEG3 is downregulated in the patients with AS and foam cells. Overexpressed MEG3 may act as an anti-atherosclerotic factor by reducing lipid accumulation and accelerating cholesterol efflux through the miR-200b-3p/ABCA1 axis.
Asunto(s)
Aterosclerosis , MicroARNs , Humanos , Aterosclerosis/genética , Bioensayo , Colesterol , Lípidos , MicroARNs/genéticaRESUMEN
OBJECTIVE: To explore the significance of succinate dehydrogenase B (SDHB) mutation and EPAS1 overexpression in Zuckerkandl paragangliomas (PGL) and examine their correlations with malignant infiltration and metastasis. METHODS: From March 2008 to July 2011, the clinical profiles of 16 Zuckerkandl PGL patients were analyzed retrospectively. For increased diagnostic specificity, a complex immunohistochemical panel of tissue microarray was performed for SDHB, EPAS1 and MIB-1. Positive expression identified as a granular cytoplasmic staining. Greater than or equal to 50% as strongly positive (+++), 1% to 10% as weakly positive (+). RESULTS: Tissue microarray immunohistochemical staining showed SDHB immunoreactivity in the cytoplasm, whereas EPAS1 and MIB-1 in the nuclear of tumor cells. Positive expression of EPAS1 in which 13 cases of Zuckerkandl PGL. And high expression strongly associated with malignancy. SDHB mutation of 7 cases are all EPAS1 positive staining. Non-gene mutation 9 cases tumor specimens, 6 cases were EPAS1 positive expression (P < 0.05). CgA positive expression in 11 cases benign Zuckerkandl PGL, strongly positive in 4 malignant cases (4/4). MIB-1 below 1% in 12 cases of benign Zuckerkandl PGL. And in 4 malignant cases, MIB-1 was about 3%. Malignant neoplasms had significantly higher EPAS1, CgA and MIB-1 expression compared to benign counterparts (P < 0.05). CONCLUSIONS: The SDHB mutation causes the EPAS1 over expression in PGL and correlation with higher positive expression of CgA and MIB-1. It may be one of the mechanisms of malignant invasiveness and metastasis in PGL.