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1.
Front Chem ; 11: 1223335, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37426336

RESUMO

The Euphorbiaceae plant Euphorbia neriifolia L. is distributed widely in India, Thailand, Southeastern China, and Taiwan and used as a carminative and expectorant to treat several inflammation-related diseases, such as gonorrhoea, asthma, and cancer. In the course of our search for potential anti-inflammatory agents from the titled plant, 11 triterpenes from the stem of E. neriifolia were isolated and reported in our previous endeavor. Given its rich abundance in triterpenoids, the ethanolic extract in this follow-up exploration has led to the isolation of additional eight triterpenes, including six new euphanes-neritriterpenols H and J-N (1 and 3-7)-one new tirucallane, neritriterpenol I (2), and a known compound, 11-oxo-kansenonol (8). Their chemical structures were elucidated on the basis of spectroscopic data, including 1D- and 2D NMR, and HRESIMS spectra. The absolute stereochemistry of neritriterpenols was determined by single-crystal X-ray diffraction analysis, ICD spectra, and DP4+ NMR data calculations. Compounds 1-8 were also evaluated for their anti-inflammatory activity by using lipopolysaccharide (LPS)-stimulated IL-6 and TNF-α on RAW 264.7 macrophage cells. Intriguingly, the euphane-type triterpenes (1 and 3-8) showed an inhibitory effect on LPS-induced IL-6 but not on TNF-α, while tirucallane-type triterpene 2 showed strong inhibition on both IL-6 and TNF-α.

2.
Nat Commun ; 14(1): 2528, 2023 05 03.
Artigo em Inglês | MEDLINE | ID: mdl-37137912

RESUMO

Oxidized cysteine residues are highly reactive and can form functional covalent conjugates, of which the allosteric redox switch formed by the lysine-cysteine NOS bridge is an example. Here, we report a noncanonical FAD-dependent enzyme Orf1 that adds a glycine-derived N-formimidoyl group to glycinothricin to form the antibiotic BD-12. X-ray crystallography was used to investigate this complex enzymatic process, which showed Orf1 has two substrate-binding sites that sit 13.5 Å apart unlike canonical FAD-dependent oxidoreductases. One site could accommodate glycine and the other glycinothricin or glycylthricin. Moreover, an intermediate-enzyme adduct with a NOS-covalent linkage was observed in the later site, where it acts as a two-scissile-bond linkage facilitating nucleophilic addition and cofactor-free decarboxylation. The chain length of nucleophilic acceptors vies with bond cleavage sites at either N-O or O-S accounting for N-formimidoylation or N-iminoacetylation. The resultant product is no longer sensitive to aminoglycoside-modifying enzymes, a strategy that antibiotic-producing species employ to counter drug resistance in competing species.


Assuntos
Aminoglicosídeos , Cisteína , Cisteína/química , Ligantes , Sítios de Ligação , Antibacterianos , Cristalografia por Raios X , Glicina
3.
Nat Prod Res ; : 1-8, 2023 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-36606546

RESUMO

The spirohydantoin-containing cucurbitane-type triterpenoid, kaguacidine A (1), was isolated and purified from 95% ethanol extract of vines of Momordica charantia L. (Cucurbitaceae). Its unprecedented chemical structure, a spirohydantoin substituent at C-23 of cucurbitane, was elucidated by extensive spectroscopic analyses, including HRESIMS, IR, optical rotation, 1 D- and 2 D-NMR spectra. The possible biosynthetic pathway is deduced and may be attributed to the metabolic activity of microbial symbionts in M. charantia L. Compound 1 was evaluated for anti-inflammatory activity against LPS-induced NO production in RAW 264.7 cells and anti-proliferative activity against four cancer cell lines, including HEp-2, MCF-7, Hep-G2, and WiDr. Compound 1 showed moderate anti-inflammatory activity with an IC50 value of 18.5 ± 0.4 µg/mL and weak anti-proliferative activity against MCF-7, HEp-2, Hep-G2, and WiDr with IC50 values of >40, 33.8 ± 0.6, 31.0 ± 0.7, and 27.0 ± 0.7 µM, respectively.

4.
Appl Environ Microbiol ; 88(17): e0080622, 2022 09 13.
Artigo em Inglês | MEDLINE | ID: mdl-36000868

RESUMO

Albofungin, a hexacyclic aromatic natural product, exhibits broad-spectrum antimicrobial activity. Its biosynthesis, regulation, and resistance remain elusive. Here, we report the albofungin (abf) biosynthetic gene cluster (BGC) from its producing strain Streptomyces tumemacerans JCM5050. The nascent abf BGC encodes 70 putative genes, including regulators, transporters, type II polyketide synthases (PKSs), oxidoreductase, and tailoring enzymes. To validate the intactness and functionality of the BGC, we developed an Escherichia coli-Streptomyces shuttle bacterial artificial chromosome system, whereby the abf BGC was integrated into the genome of a nonproducing host via heterologous conjugation, wherefrom albofungin can be produced, confirming that the BGC is in effect. We then delimited the boundaries of the BGC by means of in vitro CRISPR-Cas9 DNA editing, concluding a minimal but essential 60-kb abf BGC ranging from orfL to abf58. The orfA gene encoding a reduced flavin adenine dinucleotide (FADH2)-dependent halogenase was examined and is capable of transforming albofungin to halogen-substituted congeners in vivo and in vitro. The orfL gene encoding a transporter was examined in vivo. The presence/absence of orfA or orfL demonstrated that the MIC of albofungin is subject to alteration when an extracellular polysaccharide intercellular adhesin was formed. Despite that halogenation of albofungin somewhat increases binding affinity to transglycosylase (TGase), albofungin with/without a halogen substituent manifests similar in vitro antimicrobial activity. Halogenation, however, limits overall dissemination and effectiveness given a high secretion rate, weak membrane permeability, and high hydrophobicity of the resulting products, whereby the functions of orfA and orfL are correlated with drug detoxification/resistance for the first time. IMPORTANCE Albofungin, a natural product produced from Streptomycetes, exhibits bioactivities against bacteria, fungi, and tumor cells. The biosynthetic logic, regulations, and resistance of albofungin remain yet to be addressed. Herein, the minimal albofungin (abf) biosynthetic gene cluster (BGC) from the producing strain Streptomyces tumemacerans JCM5050 was precisely delimited using the Escherichia coli-Streptomyces shuttle bacterial artificial chromosome system, of which the gene essentiality was established in vivo and in vitro. Next, we characterized two genes orfA and orfL encoded in the abf BGC, which act as a reduced flavin adenine dinucleotide (FADH2)-dependent halogenase and an albofungin-congeners transporter, respectively. While each testing microorganism exhibited different sensitivities to albofungins, the MIC values of albofungins against testing strains with/without orfA and/or orfL were subject to considerable changes. Halogen-substituted albofungins mediated by OrfA manifested overall compromised dissemination and effectiveness, revealing for the first time that two functionally distinct proteins OrfA and OrfL are associated together, exerting a novel "belt and braces" mechanism in antimicrobial detoxification/resistance.


Assuntos
Anti-Infecciosos , Produtos Biológicos , Streptomyces , Anti-Infecciosos/metabolismo , Produtos Biológicos/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo , Flavina-Adenina Dinucleotídeo/metabolismo , Halogenação , Halogênios/metabolismo , Família Multigênica , Streptomyces/genética , Xantenos
5.
Sci Rep ; 12(1): 429, 2022 01 10.
Artigo em Inglês | MEDLINE | ID: mdl-35013458

RESUMO

Having infected by Helicobacter pylori, the infection often leads to gastritis, gastric ulcer, or even gastric cancer. The disease is typically treated with antibiotics as they used to effectively inhibit or kill H. pylori, thus reducing the incidence of gastric adenoma and cancer to significant extent. H. pylori, however, has developed drug resistance to many clinically used antibiotics over the years, highlighting the crisis of antibiotic failure during the H. pylori treatment. We report here that the fucoidan from Sargassum hemiphyllum can significantly reduce the infection of H. pylori without developing to drug resistance. Fucoidan appears to be a strong anti-inflammation agent as manifested by the RAW264.7 cell model examination. Fucoidan can prohibit H. pylori adhesion to host cells, thereby reducing the infection rate by 60%, especially in post treatment in the AGS cell model assay. Mechanistically, fucoidan intervenes the adhesion of BabA and AlpA of H. pylori significantly lowering the total count of H. pylori and the level of IL-6 and TNF-α in vivo. These results all converge on the same fact that fucoidan is an effective agent in a position to protect the stomach from the H. pylori infection by reducing both the total count and induced inflammation.


Assuntos
Antineoplásicos/uso terapêutico , Infecções por Helicobacter/tratamento farmacológico , Polissacarídeos/uso terapêutico , Sargassum/química , Animais , Antineoplásicos/isolamento & purificação , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Citocinas/metabolismo , Avaliação Pré-Clínica de Medicamentos , Helicobacter pylori/efeitos dos fármacos , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Polissacarídeos/isolamento & purificação , Polissacarídeos/farmacologia , Células RAW 264.7 , Estômago/efeitos dos fármacos , Estômago/imunologia , Estômago/metabolismo
6.
Cancers (Basel) ; 12(9)2020 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-32872195

RESUMO

(1) Background: Radiotherapy (RT) is one of the major treatments for non-small cell lung cancer, but RT-associated toxicities usually impede its anticancer effect. Nutrient supplementation has been applied for cancer prevention or a complementary measure to anticancer therapy. Here, we explored the influence of total nutrition supplementation before and after cancer occurrence on the anticancer benefit and side effects of RT. (2) Methods: C57BL/6JNarl mice were inoculated with Lewis lung carcinoma cells and then treated with radiotherapy. TNuF, a total nutrition formula, was prescribed by oral gavage. In the preventive groups, TNuF supplementation started from seven days before tumor inoculation. In the complementary groups, TNuF supplementation began after tumor inoculation. (3) Results: TNuF successfully enhanced the anticancer effect of RT against primary tumor and lung metastasis. Additionally, the complementary supplement improved the high serum TNF-α level and the wasting of sartorius muscle in mice receiving RT. In histologic and molecular analysis, TNuF was observed to modulate EGFR, apoptosis, and VEGF and PD-1/PD-L1 pathways. Furthermore, the anticancer benefit of the preventive supplement was comparable to that of the complementary administration. (4) Conclusions: Our results demonstrated that the prescription of the TNuF total nutrition formula before and after cancer diagnosis attains similar benefits in testing subjects with typical anticancer RT. TNuF is also a potential sensitizer to anti-PD-1 immune therapy.

7.
Biomolecules ; 10(5)2020 05 09.
Artigo em Inglês | MEDLINE | ID: mdl-32397467

RESUMO

Plant type III polyketide synthases produce diverse bioactive molecules with a great medicinal significance to human diseases. Here, we demonstrated versatility of a stilbene synthase (STS) from Pinus Sylvestris, which can accept various non-physiological substrates to form unnatural polyketide products. Three enzymes (4-coumarate CoA ligase, malonyl-CoA synthetase and engineered benzoate CoA ligase) along with synthetic chemistry was practiced to synthesize starter and extender substrates for STS. Of these, the crystal structures of benzoate CoA ligase (BadA) from Rhodopseudomonas palustris in an apo form or in complex with a 2-chloro-1,3-thiazole-5-carboxyl-AMP or 2-methylthiazole-5-carboxyl-AMP intermediate were determined at resolutions of 1.57 Å, 1.7 Å, and 2.13 Å, respectively, which reinforces its capacity in production of unusual CoA starters. STS exhibits broad substrate promiscuity effectively affording structurally diverse polyketide products. Seven novel products showed desired cytotoxicity against a panel of cancer cell lines (A549, HCT116, Cal27). With the treatment of two selected compounds, the cancer cells underwent cell apoptosis in a dose-dependent manner. The precursor-directed biosynthesis alongside structure-guided enzyme engineering greatly expands the pharmaceutical repertoire of lead compounds with promising/enhanced biological activities.


Assuntos
Acil Coenzima A/metabolismo , Aciltransferases/metabolismo , Coenzima A Ligases/metabolismo , Rodopseudomonas/enzimologia , Acil Coenzima A/química , Acil Coenzima A/genética , Apoptose , Vias Biossintéticas , Domínio Catalítico , Linhagem Celular Tumoral , Forma Celular , Sobrevivência Celular , Cristalografia por Raios X , Humanos , Modelos Moleculares , Mutação/genética , Policetídeos/química , Policetídeos/metabolismo
8.
J Oncol ; 2019: 9206951, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31781219

RESUMO

Lung cancer and its related cachexia are the leading cause of cancer death in the world. In this study, we report the inhibitory effect of the combined therapy of Astragalus membranaceus and Angelica sinensis, on tumor growth and cachexia in tumor-bearing mice. Lewis lung carcinoma cells were inoculated into male C57BL/6 and CAnN.Cg-Foxn1nu nude mice. After tumor inoculation, mice were fed orally by the combination of AM and AS in different doses. In C57BL/6 mice, the combination of AM and AS significantly inhibited the growth of cancer tumor and prevented the loss of body weight and skeletal muscle. It also diminished the formation of free radicals and cytokines, stimulated the differentiation of NK and Tc cells, and rebalanced the ratios of Th/Tc cells, Th1/Th2 cytokines, and M1/M2 tumor-associated macrophages. The herbal combination also downregulated the expression of NFκΒ, STAT3, HIF-1α, and VEGF in tumors. In contrast, the findings were not observed in the nude mice. Therefore, the combination of AM and AS is confirmed to inhibit the progression of lung cancer, cancer cachexia, and cancer inflammation through the immunomodulatory function.

9.
Nutrients ; 11(8)2019 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-31426614

RESUMO

Non-small-cell lung cancer (NSCLC) causes high mortality. Radiotherapy is an induction regimen generally applied to patients with NSCLC. In view of therapeutic efficacy, the outcome is not appealing in addition to bringing about unwanted side effects. Total nutrition is a new trend in cancer therapy, which benefits cancer patients under radiotherapy. Male C57BL/6JNarl mice were experimentally divided into five groups: one control group, one T group (borne with Lewis lung carcinoma but no treatment), and three Lewis lung carcinoma-bearing groups administrated with a total nutrition formula (T + TNuF group), a local radiotherapy plus daily 3 Gy in three fractions (T + R group), or a combination TNuF and radiotherapy (T + R + TNuF group). These mice were assessed for their mean tumor volumes, cachectic symptoms and tumor metastasis. TNuF administration significantly suppressed tumor growth and activated apoptotic cell death in NSCLC-bearing mice under radiation. The body-weight gain was increased, while the radiation-induced cachexia was alleviated. Analysis of mechanisms suggests that TNuF downregulates EGFR and VEGF signaling pathways, inhibiting angiogenesis and metastasis. In light of radiation-induced tumor cell death, mitigation of radiation-induced cachexia and inhibition of tumor cell distant metastasis, the combination of TNuF and radiotherapy synergistically downregulates EGFR and VEGF signaling in NSCLC-bearing mice.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/terapia , Suplementos Nutricionais , Neoplasias Pulmonares/terapia , Nutrientes/uso terapêutico , Terapia Nutricional , Radiossensibilizantes/uso terapêutico , Animais , Apoptose , Caquexia , Carcinoma Pulmonar de Lewis , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Carcinoma Pulmonar de Células não Pequenas/patologia , Linhagem Celular Tumoral , Terapia Combinada , Receptores ErbB/metabolismo , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Masculino , Camundongos Endogâmicos C57BL , Neovascularização Patológica , Transdução de Sinais , Carga Tumoral , Fator A de Crescimento do Endotélio Vascular/metabolismo , Aumento de Peso , Ensaios Antitumorais Modelo de Xenoenxerto
10.
J Ethnopharmacol ; 243: 112075, 2019 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-31291609

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Cisplatin is an important chemotherapy to lung cancer, but it usually induces severe cachexia and acute kidney injury in patients. Scutellaria baicalensis Georgi (SB), commonly known as a skullcap, is a popular Chinese herbal medicine mainly used to treat inflammation, infection, and malignancy. In this study, we report the synergic effect of SB and cisplatin to Lewis lung carcinoma (LLC) cells, and the ameliorative effect of SB to cisplatin-induced cachexia and acute kidney injury. MATERIALS AND METHODS: The extract of SB was applied by water boiling and lyophilization. The MTS assay was used to exam the in-vitro effects of SB and cisplatin on the LLC viability. In the animal experiment, male C57BL/6J mice were inoculated with LLC cells, and then treated by cisplatin intraperitoneally and the SB extract orally. Tumor volume, weights of tumor, murine body, white adipose tissue and gastrocnemius muscle, as well as serum levels of BUN and creatinine were measured during the experiment. Murine kidney sample was observed after the H&E and annexin V staining. RESULTS: SB provided an enhancement of cisplatin action to inhibit tumor growth in vitro and in vivo. In the animal experiment, SB improved the loss of murine body weight and gastrocnemius muscle, the elevating BUN level, and the apoptosis of renal tubular cells in mice receiving cisplatin therapy. Meanwhile, the current treatment of SB did not further interfere with the blood cell counts of mice receiving chemotherapy. CONCLUSION: SB can enhance the anti-cancer effect of cisplatin. It also attenuates cisplatin-induced cachexia and acute kidney injury.


Assuntos
Injúria Renal Aguda/tratamento farmacológico , Antineoplásicos/uso terapêutico , Caquexia/tratamento farmacológico , Carcinoma Pulmonar de Lewis/tratamento farmacológico , Cisplatino/uso terapêutico , Extratos Vegetais/uso terapêutico , Animais , Antineoplásicos/efeitos adversos , Peso Corporal/efeitos dos fármacos , Carcinoma Pulmonar de Lewis/patologia , Cisplatino/efeitos adversos , Sinergismo Farmacológico , Masculino , Camundongos Endogâmicos C57BL , Músculo Esquelético/efeitos dos fármacos , Scutellaria baicalensis , Carga Tumoral/efeitos dos fármacos
11.
Oncotarget ; 6(28): 25741-54, 2015 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-26325335

RESUMO

Whereas cisplatin (cis-diamminedichloroplatinum II) is a first-line medicine to treat solid cancerous tumors, it often causes serious side effects. New medicines that have an equivalent or even better therapeutic effect but with free or less side effects than cisplatin are highly anticipated in cancer therapy. Recent reports revealed that Antrodia cinnamomea (AC) possesses hepatoprotective activity in addition to anticancer. In this study, we wanted to know whether AC enhances chemo-sensitivity of cisplatin and/or alleviates cisplatin-induced hepatotoxicity, as well as the underlying mechanisms thereof. Our results indicated that AC inhibited proliferation of line-1 lung carcinoma cells and rescued hepatic HepG2 cells from cisplatin-induced cell death in vitro. The fact is that AC and cisplatin synergized to constrain growth of line-1 lung carcinoma cells in BALB/cByJ mice. Quantitative real-time PCR further revealed that AC promoted expression of apoptosis-related genes, while it decreased expression of NF-κB and VEGF in tumor tissues. In liver, AC reduced cisplatin-induced liver dysfunctions, liver inflammation and hepatic apoptosis in addition to body weight restoration. In summary, AC is able to increase cisplatin efficacy by triggering expression of apoptosis-related genes in line-1 lung cancer cells as well as to protect liver from tissue damage by avoiding cisplatin-induced hepatic inflammation and cell death.


Assuntos
Antineoplásicos/toxicidade , Antioxidantes/farmacologia , Antrodia/química , Doença Hepática Induzida por Substâncias e Drogas/prevenção & controle , Cisplatino/toxicidade , Fígado/efeitos dos fármacos , Neoplasias Pulmonares/tratamento farmacológico , Extratos Vegetais/farmacologia , Animais , Antioxidantes/isolamento & purificação , Proteínas Reguladoras de Apoptose/genética , Proteínas Reguladoras de Apoptose/metabolismo , Morte Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Doença Hepática Induzida por Substâncias e Drogas/patologia , Relação Dose-Resposta a Droga , Células Hep G2 , Humanos , Fígado/metabolismo , Fígado/patologia , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Masculino , Camundongos Endogâmicos BALB C , NF-kappa B/genética , NF-kappa B/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Fitoterapia , Extratos Vegetais/isolamento & purificação , Plantas Medicinais , Fator A de Crescimento do Endotélio Vascular/genética , Fator A de Crescimento do Endotélio Vascular/metabolismo
12.
Mar Drugs ; 13(4): 1882-900, 2015 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-25854641

RESUMO

Fucoidan, a heparin-like sulfated polysaccharide, is rich in brown algae. It has a wide assortment of protective activities against cancer, for example, induction of hepatocellular carcinoma senescence, induction of human breast and colon carcinoma apoptosis, and impediment of lung cancer cells migration and invasion. However, the anti-metastatic mechanism that fucoidan exploits remains elusive. In this report, we explored the effects of fucoidan on cachectic symptoms, tumor development, lung carcinoma cell spreading and proliferation, as well as expression of metastasis-associated proteins in the Lewis lung carcinoma (LLC) cells-inoculated mice model. We discovered that administration of fucoidan has prophylactic effects on mitigation of cachectic body weight loss and improvement of lung masses in tumor-inoculated mice. These desired effects are attributed to inhibition of LLC spreading and proliferation in lung tissues. Fucoidan also down-regulates expression of matrix metalloproteinases (MMPs), nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and vascular endothelial growth factor (VEGF). Moreover, the tumor-bearing mice supplemented with fucoidan indeed benefit from an ensemble of the chemo-phylacticity. The fact is that fucoidan significantly decreases viability, migration, invasion, and MMPs activities of LLC cells. In summary, fucoidan is suitable to act as a chemo-preventative agent for minimizing cachectic symptoms as well as inhibiting lung carcinoma metastasis through down-regulating metastatic factors VEGF and MMPs.


Assuntos
Antineoplásicos/uso terapêutico , Carcinoma Pulmonar de Lewis/tratamento farmacológico , Inibidores de Metaloproteinases de Matriz/uso terapêutico , Metaloproteinases da Matriz/metabolismo , Proteínas de Neoplasias/antagonistas & inibidores , Polissacarídeos/uso terapêutico , Fatores de Crescimento do Endotélio Vascular/antagonistas & inibidores , Animais , Antineoplásicos/administração & dosagem , Antineoplásicos/farmacologia , Caquexia/etiologia , Caquexia/prevenção & controle , Carcinoma Pulmonar de Lewis/metabolismo , Carcinoma Pulmonar de Lewis/patologia , Carcinoma Pulmonar de Lewis/secundário , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Regulação para Baixo/efeitos dos fármacos , Pulmão/efeitos dos fármacos , Pulmão/metabolismo , Pulmão/patologia , Masculino , Inibidores de Metaloproteinases de Matriz/administração & dosagem , Inibidores de Metaloproteinases de Matriz/farmacologia , Metaloproteinases da Matriz/química , Camundongos Endogâmicos C57BL , NF-kappa B/antagonistas & inibidores , NF-kappa B/metabolismo , Invasividade Neoplásica/prevenção & controle , Proteínas de Neoplasias/metabolismo , Phaeophyceae/química , Polissacarídeos/administração & dosagem , Polissacarídeos/farmacologia , Alga Marinha/química , Carga Tumoral/efeitos dos fármacos , Fatores de Crescimento do Endotélio Vascular/metabolismo
13.
Oncotarget ; 6(10): 7758-73, 2015 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-25797259

RESUMO

Chemotherapy can cause cachexia, which is manifested by weight loss, inflammation and muscle atrophy. However, the mechanisms of tumor and chemotherapy on skeletal muscle proteolysis, remained unclear. In this report, we demonstrated that tumor-induced myostatin in turn induced TNF-α, thus activating calcium-dependent and proteasomal protein degradation. Chemotherapy activated myostatin-mediated proteolysis and muscle atrophy by elevating IL-6. In tumor-bearing mice under chemotherapy, supplementation with fish oil and selenium prevented a rise in IL-6, TNF-α and myostatin and muscle atrophy. The findings presented here allow us to better understand the molecular basis of cancer cachexia and potentiate nutrition supplementation in future cancer chemotherapy.


Assuntos
Caquexia/induzido quimicamente , Caquexia/metabolismo , Óleos de Peixe/farmacologia , Músculo Esquelético/efeitos dos fármacos , Músculo Esquelético/patologia , Selênio/farmacologia , Animais , Atrofia , Caquexia/patologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Cricetinae , Docetaxel , Interleucina-6/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Miostatina/metabolismo , Taxoides/efeitos adversos , Taxoides/farmacologia , Fator de Necrose Tumoral alfa/metabolismo
14.
J Am Chem Soc ; 136(31): 10989-95, 2014 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-25095906

RESUMO

Teicoplanin A2-2 (Tei)/A40926 is the last-line antibiotic to treat multidrug-resistant Gram-positive bacterial infections, e.g., methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococcus (VRE). This class of antibiotics is powered by the N-acyltransferase (NAT) Orf11*/Dbv8 through N-acylation on glucosamine at the central residue of Tei/A40926 pseudoaglycone. The NAT enzyme possesses enormous value in untapped applications; its advanced development is hampered largely due to a lack of structural information. In this report, we present eight high-resolution X-ray crystallographic unary, binary, and ternary complexes in order to decipher the molecular basis for NAT's functionality. The enzyme undergoes a multistage conformational change upon binding of acyl-CoA, thus allowing the uploading of Tei pseudoaglycone to enable the acyl-transfer reaction to take place in the occlusion between the N- and C-halves of the protein. The acyl moiety of acyl-CoA can be bulky or lengthy, allowing a large extent of diversity in new derivatives that can be formed upon its transfer. Vancomycin/synthetic acyl-N-acetyl cysteamine was not expected to be able to serve as a surrogate for an acyl acceptor/donor, respectively. Most strikingly, NAT can catalyze formation of 2-N,6-O-diacylated or C6→C2 acyl-substituted Tei analogues through an unusual 1,4-migration mechanism under stoichiometric/solvational reaction control, wherein selected representatives showed excellent biological activities, effectively counteracting major types (VanABC) of VRE.


Assuntos
Aciltransferases/metabolismo , Antibacterianos/síntese química , Antibacterianos/farmacologia , Glicopeptídeos/síntese química , Glicopeptídeos/farmacologia , Enterococos Resistentes à Vancomicina/efeitos dos fármacos , Acilação , Aciltransferases/química , Antibacterianos/química , Biocatálise , Técnicas de Química Sintética , Glicopeptídeos/química , Modelos Moleculares , Estrutura Terciária de Proteína , Relação Estrutura-Atividade
15.
Acta Crystallogr D Biol Crystallogr ; 70(Pt 6): 1549-60, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24914966

RESUMO

In biological systems, methylation is most commonly performed by methyltransferases (MTs) using the electrophilic methyl source S-adenosyl-L-methionine (SAM) via the S(N)2 mechanism. (2S,3S)-ß-Methylphenylalanine, a nonproteinogenic amino acid, is a building unit of the glycopeptide antibiotic mannopeptimycin. The gene product of mppJ from the mannopeptimycin-biosynthetic gene cluster is the MT that methylates the benzylic C atom of phenylpyruvate (Ppy) to give ßMePpy. Although the benzylic C atom of Ppy is acidic, how its nucleophilicity is further enhanced to become an acceptor for C-methylation has not conclusively been determined. Here, a structural approach is used to address the mechanism of MppJ and to engineer it for new functions. The purified MppJ displays a turquoise colour, implying the presence of a metal ion. The crystal structures reveal MppJ to be the first ferric ion SAM-dependent MT. An additional four structures of binary and ternary complexes illustrate the molecular mechanism for the metal ion-dependent methyltransfer reaction. Overall, MppJ has a nonhaem iron centre that bind, orients and activates the α-ketoacid substrate and has developed a sandwiched bi-water device to avoid the formation of the unwanted reactive oxo-iron(IV) species during the C-methylation reaction. This discovery further prompted the conversion of the MT into a structurally/functionally unrelated new enzyme. Through stepwise mutagenesis and manipulation of coordination chemistry, MppJ was engineered to perform both Lewis acid-assisted hydration and/or O-methyltransfer reactions to give stereospecific new compounds. This process was validated by six crystal structures. The results reported in this study will facilitate the development and design of new biocatalysts for difficult-to-synthesize biochemicals.


Assuntos
Ferro/química , Metiltransferases/química , Cristalografia por Raios X , Modelos Moleculares , Conformação Proteica , Engenharia de Proteínas , Streptomyces/enzimologia
16.
Acta Crystallogr D Biol Crystallogr ; 70(Pt 5): 1401-10, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24816108

RESUMO

Utilization of N-acetylhexosamine in bifidobacteria requires the specific lacto-N-biose/galacto-N-biose pathway, a pathway differing from the Leloir pathway while establishing symbiosis between humans and bifidobacteria. The gene lnpB in the pathway encodes a novel hexosamine kinase NahK, which catalyzes the formation of N-acetylhexosamine 1-phosphate (GlcNAc-1P/GalNAc-1P). In this report, seven three-dimensional structures of NahK in complex with GlcNAc, GalNAc, GlcNAc-1P, GlcNAc/AMPPNP and GlcNAc-1P/ADP from both Bifidobacterium longum (JCM1217) and B. infantis (ATCC15697) were solved at resolutions of 1.5-2.2 Å. NahK is a monomer in solution, and its polypeptide folds in a crescent-like architecture subdivided into two domains by a deep cleft. The NahK structures presented here represent the first multiple reaction complexes of the enzyme. This structural information reveals the molecular basis for the recognition of the given substrates and products, GlcNAc/GalNAc, GlcNAc-1P/GalNAc-1P, ATP/ADP and Mg(2+), and provides insights into the catalytic mechanism, enabling NahK and mutants thereof to form a choice of biocatalysts for enzymatic and chemoenzymatic synthesis of carbohydrates.


Assuntos
Bifidobacterium/enzimologia , Fosfotransferases/química , Fosfotransferases/metabolismo , Acetilglucosamina/metabolismo , Difosfato de Adenosina/metabolismo , Trifosfato de Adenosina/metabolismo , Bifidobacterium/metabolismo , Sítios de Ligação , Cristalografia por Raios X , Magnésio/metabolismo , Modelos Moleculares , Mutagênese Sítio-Dirigida , Fosfotransferases/genética , Conformação Proteica , Especificidade por Substrato
17.
PLoS One ; 8(1): e52912, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23349693

RESUMO

Growing evidence has shown that regulatory T cells (Tregs) and myeloid-derived suppressor cells (MDSCs) abnormally increase in cancer cachectic patients. Suppressions of Tregs and MDSCs may enhance anti-tumor immunity for cancer patients. Fish oil and selenium have been known to have many biological activities such as anti-inflammation and anti-oxidation. Whether fish oil and/or selenium have an additional effect on population of immunosuppressive cells in tumor-bearing hosts remained elusive and controversial. To gain insights into their roles on anti-tumor immunity, we studied the fish oil- and/or selenium-mediated tumor suppression and immunity on lung carcinoma, whereof cachexia develops. Advancement of cachexia in a murine lung cancer model manifested with such indicative symptoms as weight loss, chronic inflammation and disturbed immune functionality. The elevation of Tregs and MDSCs in spleens of tumor-bearing mice was positively correlated with tumor burdens. Consumption of either fish oil or selenium had little or no effect on the levels of Tregs and MDSCs. However, consumption of both fish oil and selenium together presented a synergistic effect--the population of Tregs and MDSCs decreased as opposed to increase of anti-tumor immunity when both fish oil and selenium were supplemented simultaneously, whereby losses of body weight and muscle/fat mass were alleviated significantly.


Assuntos
Antineoplásicos/farmacologia , Óleos de Peixe/farmacologia , Tolerância Imunológica/efeitos dos fármacos , Neoplasias Pulmonares/imunologia , Saccharomyces cerevisiae/fisiologia , Selênio/metabolismo , Baço/imunologia , Animais , Antineoplásicos/uso terapêutico , Células 3T3 BALB , Caquexia/complicações , Caquexia/dietoterapia , Caquexia/microbiologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Suplementos Nutricionais , Regulação para Baixo/efeitos dos fármacos , Óleos de Peixe/uso terapêutico , Humanos , Imunocompetência/efeitos dos fármacos , Imunocompetência/imunologia , Neoplasias Pulmonares/dietoterapia , Neoplasias Pulmonares/microbiologia , Neoplasias Pulmonares/patologia , Masculino , Camundongos , Células Mieloides/imunologia , Saccharomyces cerevisiae/metabolismo , Linfócitos T Citotóxicos/efeitos dos fármacos , Linfócitos T Citotóxicos/imunologia , Linfócitos T Citotóxicos/microbiologia , Regulação para Cima/efeitos dos fármacos
18.
Antiviral Res ; 95(2): 128-34, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22643729

RESUMO

Enterovirus 71 (EV 71), the newest member of Enteroviridae, is notorious for its etiological role in epidemics of the hand-foot-and-mouth disease, particularly in association with fatal neurological complications in young children. Searching for new and more effective agents against EV 71 infections has never relented as corresponding vaccines or antiviral drugs remain unavailable. Sulfated polysaccharides from seaweed are known to possess a broad range of biological activities across anti-virus, anti-tumor, immunomodulation, anti-coagulation, etc. In this study, we report kappa carrageenan also has a strong and effective anti-EV 71 activity able to reduce plaque formation, prevent viral replication before or during viral adsorption, as well as inhibit EV 71-induced apoptosis. In virus binding assay, kappa carrageenan was shown able to bind EV 71 firmly, forming carrageenan-viruses complexes, whereby the virus-receptor interaction is likely disrupted. Added together, kappa carrageenan may be an ideal candidate worthwhile to develop into anti-EV 71 agents.


Assuntos
Antivirais/farmacologia , Carragenina/farmacologia , Enterovirus Humano A/efeitos dos fármacos , Internalização do Vírus/efeitos dos fármacos , Animais , Apoptose/efeitos dos fármacos , Chlorocebus aethiops , Enterovirus Humano A/isolamento & purificação , Infecções por Enterovirus/virologia , Humanos , Testes de Sensibilidade Microbiana , Células Vero , Ensaio de Placa Viral
19.
Eur J Cancer ; 48(7): 1074-84, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-21782419

RESUMO

BACKGROUND: Cancer cachexia is characterised by the loss of body mass and directly compromises immune response and the quality of life of cancer patients. In the present study, we set out to investigate the role of Chinese herbs as anticancer medicines and/or chemotherapeutic adjuvants to increase therapeutic efficacy and/or ameliorate given side-effects in animal model. METHODS: Twelve kinds of herbs were chosen from the ingredients of major Chinese herbal medicines, and their effects on the antioxidant activity were investigated. To obtain the anticancer effects of 5-fluorouracil (5-FU) when consumed with minimal side-effects, we investigated the combination effect of Scutellaria baicalensis and Qing-Shu-Yi-Qi-Tang that may enhance the anticancer activity of 5-FU on subcutaneous tumour growth in C57BL/6 mice challenged with Lewis lung carcinoma cells. RESULTS: Qing-Shu-Yi-Qi-Tang, a multiple-component herbal extract, was shown to have high anti-oxidation activity, while S. baicalensis (Chinese skullcap) was demonstrated to have high tumour-growth inhibition activity. Thus, S. baicalensis and Qing-Shu-Yi-Qi-Tang were evaluated for their combinaton effects on the cancer-induced cachectic murine upon receiving 5-FU chemotherapy. As a result, tumour masses and losses of carcass and/or gastrocnemius muscle were found to be significantly decreased. This combination otherwise increased both Th1/Th2 ratio and NK cytotoxicity. In the mice receiving with or without 5-FU, the serum levels of monocyte chemoattractant protein-1 (MCP-1) increased by all means but otherwise decreased when the herbal combination was administrated. Additionally, the expressions of nuclear factor-kappa B (NF-κB) and muscle RING finger protein-1 (MuRF-1) decreased in the gastrocnemius muscle when the herbal combination was applied. CONCLUSION: Our results revealed that the combination of S. baicalensis and Qing-Shu-Yi-Qi-Tang is able to ameliorate cachectic symptoms and positively stimulate anti-tumour immunity while undergoing chemotherapy in animal model.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Caquexia/tratamento farmacológico , Carcinoma Pulmonar de Lewis/tratamento farmacológico , Carcinoma Pulmonar de Lewis/imunologia , Medicamentos de Ervas Chinesas/administração & dosagem , Fluoruracila/administração & dosagem , Extratos Vegetais/administração & dosagem , Animais , Antioxidantes/administração & dosagem , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Scutellaria baicalensis , Células Th1/efeitos dos fármacos , Células Th2/efeitos dos fármacos
20.
Cancer Lett ; 305(1): 40-9, 2011 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-21397390

RESUMO

Cachexia, also known as wasting syndrome notably with skeletal muscle atrophy, costs nearly one-third of all cancer deaths in man. (-)-Epigallocatechin-3-gallate (EGCG), the principal polyphenolic component in green tea, is a potent preventive against cachexia as well as cancers. However, how EGCG counteracts cachexia-provoked muscle wasting is unclear. EGCG was demonstrated to be able to retard tumor progression as well as to prevent body weight from loss, because EGCG attenuates skeletal muscle leukocytic infiltration and down-regulates tumor-induced NF-κB and E3-ligases in muscle. In mice, the dosages optimized against cachexia were determined to be 0.2 mg/mouse/day for prevention and to be 0.6 mg/mouse/day for treatment. Anti-cachexia effects were assessed using the LLC tumor model. Mice with the same body weight were divided into groups, including control, tumor bearing, and tumor-bearing but receiving water or EGCG in both prevention and treatment experiments. RT-PCR was used to assess mRNA expressions of NF-κB, MuRF 1, and MAFbx. The intracellular NF-κB, MuRF 1 and MAFbx were determined and quantified by immunofluorescence and Western blotting, respectively. Our results conclude EGCG regulates the expressions of NF-κB as well as downstream mediators, MuRF 1 and MAFbx, so EGCG may be an appropriate agent to be included in ensemble therapeutics of the tumor-induced muscle atrophy.


Assuntos
Anticarcinógenos/uso terapêutico , Caquexia/tratamento farmacológico , Carcinoma Pulmonar de Lewis/tratamento farmacológico , Catequina/análogos & derivados , Músculo Esquelético/efeitos dos fármacos , Atrofia Muscular/tratamento farmacológico , Animais , Western Blotting , Caquexia/etiologia , Caquexia/metabolismo , Carcinoma Pulmonar de Lewis/complicações , Carcinoma Pulmonar de Lewis/metabolismo , Catequina/uso terapêutico , Imunofluorescência , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Proteínas Musculares/biossíntese , Músculo Esquelético/metabolismo , Músculo Esquelético/patologia , Atrofia Muscular/etiologia , Atrofia Muscular/metabolismo , NF-kappa B/biossíntese , RNA Mensageiro/análise , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Proteínas Ligases SKP Culina F-Box/biossíntese , Transdução de Sinais/efeitos dos fármacos , Proteínas com Motivo Tripartido , Ubiquitina-Proteína Ligases/biossíntese
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