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1.
Nature ; 559(7714): 415-418, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29995859

RESUMO

Bioactive natural products have evolved to inhibit specific cellular targets and have served as lead molecules for health and agricultural applications for the past century1-3. The post-genomics era has brought a renaissance in the discovery of natural products using synthetic-biology tools4-6. However, compared to traditional bioactivity-guided approaches, genome mining of natural products with specific and potent biological activities remains challenging4. Here we present the discovery and validation of a potent herbicide that targets a critical metabolic enzyme that is required for plant survival. Our approach is based on the co-clustering of a self-resistance gene in the natural-product biosynthesis gene cluster7-9, which provides insight into the potential biological activity of the encoded compound. We targeted dihydroxy-acid dehydratase in the branched-chain amino acid biosynthetic pathway in plants; the last step in this pathway is often targeted for herbicide development10. We show that the fungal sesquiterpenoid aspterric acid, which was discovered using the method described above, is a sub-micromolar inhibitor of dihydroxy-acid dehydratase that is effective as a herbicide in spray applications. The self-resistance gene astD was validated to be insensitive to aspterric acid and was deployed as a transgene in the establishment of plants that are resistant to aspterric acid. This herbicide-resistance gene combination complements the urgent ongoing efforts to overcome weed resistance11. Our discovery demonstrates the potential of using a resistance-gene-directed approach in the discovery of bioactive natural products.


Assuntos
Produtos Biológicos/metabolismo , Produtos Biológicos/farmacologia , Herbicidas/metabolismo , Herbicidas/farmacologia , Compostos Heterocíclicos com 3 Anéis/metabolismo , Compostos Heterocíclicos com 3 Anéis/farmacologia , Arabidopsis/efeitos dos fármacos , Arabidopsis/enzimologia , Arabidopsis/genética , Arabidopsis/crescimento & desenvolvimento , Produtos Biológicos/análise , Inibidores Enzimáticos/análise , Inibidores Enzimáticos/farmacologia , Resistência a Herbicidas/genética , Herbicidas/análise , Compostos Heterocíclicos com 3 Anéis/análise , Hidroliases/antagonistas & inibidores , Hidroliases/química , Hidroliases/metabolismo , Modelos Moleculares , Família Multigênica/genética , Reguladores de Crescimento de Plantas/análise , Reguladores de Crescimento de Plantas/farmacologia , Plantas Geneticamente Modificadas/genética , Transgenes/genética
2.
J Am Chem Soc ; 145(49): 27131-27139, 2023 12 13.
Artigo em Inglês | MEDLINE | ID: mdl-38018127

RESUMO

Azoxy compounds exhibit a wide array of biological activities and possess distinctive chemical properties. Although there has been considerable interest in the biosynthetic mechanisms of azoxy metabolites, the enzymatic basis responsible for azoxy bond formation has remained largely enigmatic. In this study, we unveil the enzyme cascade that constructs the azoxy bond in valanimycin biosynthesis. Our research demonstrates that a pair of metalloenzymes, comprising a membrane-bound hydrazine synthase and a nonheme diiron azoxy synthase, collaborate to convert an unstable pathway intermediate to an azoxy product through a hydrazine-azo-azoxy pathway. Additionally, by characterizing homologues of this enzyme pair from other azoxy metabolite pathways, we propose that this two-enzyme cascade could represent a conserved enzymatic strategy for azoxy bond formation in bacteria. These findings provide significant mechanistic insights into biological N-N bond formation and should facilitate the targeted isolation of bioactive azoxy compounds through genome mining.


Assuntos
Bactérias , Hidrazinas
3.
Molecules ; 28(15)2023 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-37570714

RESUMO

Secoisolariciresinol (SECO) is one of the major lignans occurring in various grains, seeds, fruits, and vegetables. The gut microbiota plays an important role in the biotransformation of dietary lignans into enterolignans, which might exhibit more potent bioactivities than the precursor lignans. This study aimed to identify, synthesize, and evaluate the microbial metabolites of SECO and to develop efficient lead compounds from the metabolites for the treatment of osteoporosis. SECO was fermented with human gut microbiota in anaerobic or micro-aerobic environments at different time points. Samples derived from microbial transformation were analyzed using an untargeted metabolomics approach for metabolite identification. Nine metabolites were identified and synthesized. Their effects on cell viability, osteoblastic differentiation, and gene expression were examined. The results showed that five of the microbial metabolites exerted potential osteogenic effects similar to those of SECO or better. The results suggested that the enterolignans might account for the osteoporotic effects of SECO in vivo. Thus, the presence of the gut microbiota could offer a good way to form diverse enterolignans with bone-protective effects. The current study improves our understanding of the microbial transformation products of SECO and provides new approaches for new candidate identification in the treatment of osteoporosis.


Assuntos
4-Butirolactona , Lignanas , Humanos , Dieta , Lignanas/farmacologia , Lignanas/metabolismo , Butileno Glicóis/farmacologia , Butileno Glicóis/metabolismo
4.
Molecules ; 27(3)2022 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-35163988

RESUMO

The Zuojin Pill consists of Coptidis Rhizoma (CR) and Euodiae Fructus (EF). It has been a classic prescription for the treatment of gastrointestinal diseases in China since ancient times. Alkaloids are considered to be its main pharmacologically active substances. The authors of the present study investigated the feasibility of preparing high purity total alkaloids (TAs) from CR and EF extracts separately and evaluated the effect for the treatment of bile reflux gastritis (BRG). Coptis chinensis Franch. and Evodia rutaecarpa (Juss.) Benth. were used in the study. An optimized method for the enrichment and purification of TAs with macroporous resin was established. Furthermore, qualitative analysis by using ultra-high performance liquid chromatography coupled with electrospray ionization and quadrupole-time of flight mass spectrometry (UHPLC-ESI-QTOF-MS) was explored to identify the components of purified TAs. Thirty-one compounds, thirty alkaloids and one phenolic compound, were identified or tentatively assigned by comparison with reference standards or literature data. A method of ultra-high performance liquid chromatography coupled with diode array detector (UHPLC-DAD) for quantitative analysis was also developed. The contents of nine alkaloids were determined. Moreover, a rat model of BRG was used to investigate the therapeutic effect of the combination of purified TAs from CR and EF. Gastric pathologic examination suggested that the alkaloids' combination could markedly attenuate the pathological changes of gastric mucosa.


Assuntos
Alcaloides/isolamento & purificação , Alcaloides/farmacologia , Refluxo Biliar/tratamento farmacológico , Coptis/química , Evodia/química , Gastrite/tratamento farmacológico , Resinas Vegetais/química , Alcaloides/química , Animais , Refluxo Biliar/metabolismo , Refluxo Biliar/patologia , Gastrite/metabolismo , Gastrite/patologia , Ratos , Ratos Sprague-Dawley
5.
J Am Chem Soc ; 2021 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-34132537

RESUMO

Acetohydroxyacid synthase (AHAS) is the first enzyme in the branched-chain amino acid biosynthetic pathway and is a validated target for herbicide and fungicide development. Here we report harzianic acid (HA, 1) produced by the biocontrol fungus Trichoderma afroharzianum t-22 (Tht22) as a natural product inhibitor of AHAS. The biosynthetic pathway of HA was elucidated with heterologous reconstitution. Guided by a putative self-resistance enzyme in the genome, HA was biochemically demonstrated to be a selective inhibitor of fungal AHAS, including those from phytopathogenic fungi. In addition, HA can inhibit a common resistant variant of AHAS in which the active site proline is mutated. Structural analysis of AHAS complexed with HA revealed the molecular basis of competitive inhibition, which differs from all known commercial AHAS inhibitors. The alternative binding mode also rationalizes the selectivity of HA, as well as effectiveness toward resistant mutants. A proposed role of HA biosynthesis by Tht22 in the rhizosphere is discussed based on the data.

6.
BMC Infect Dis ; 19(1): 535, 2019 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-31208369

RESUMO

BACKGROUND: Cysticercosis is spreading all over the world and it is a major health problem in most countries of Latin America, Africa, and Asia. Extensive disseminated cysticercosis is relatively rare and fewer than 120 case have been reported in the worldwide. We reported a rare case of extensive disseminated cysticercosis in Yunan province, China. CASE PRESENTATION: A rare case of extensive disseminated cysticercosis, in a 61-year-old male Chinese was detected from Yunnan province in 2018. Clinical and etiological examination was performed, as well as the epidemiological investigation. CONCLUSION: The life cycle of T. solium in the area where the case came from is complete. We expect this case could raise the attentions to the control of Taenia solium infection and subsequent cysticercosis there.


Assuntos
Cisticercose/diagnóstico , Taenia solium , Animais , China , Cisticercose/diagnóstico por imagem , Humanos , Masculino , Pessoa de Meia-Idade , Tomografia Computadorizada por Raios X
7.
Cell Tissue Bank ; 20(3): 379-387, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31240495

RESUMO

To evaluate the characteristics of microbiological contamination in donor corneas preserved for medium-term. A total of 82 donated corneas from June 1, 2014 to November 30, 2014 were retrospectively analyzed. The corneas were preserved in cornea chambers medium-term solution at 4-8 °C for keratoplasty. After removal of the central corneas for transplantation, the corneoscleral rims were put back into the medium for 1 month at room temperature (20-25 °C). The suspicious contaminated storage solutions indicated with transparency or color change were examined with bacteria and fungi cultivation for strain identification. The data collected included gender, age, procurement site and causes of death of donors, and follow-up of recipients. Statistical analysis was performed using Microsoft Excel and SPSS 24.0. Significance level was set at a P value < 0.05. The overall pathogen positive rate was 9.8% (n = 8), including 7 (87.5%) fungi and 1 (12.5%) bacteria. They were 2 (2.44%) Fusarium, 2 (2.44%) Chromomycosis, 1 (1.22%) Candida albicans, 1 (1.22%) Aspergillus versicolor, 1 (1.22%) Acremonium species, and 1 (1.22%) Enterococcus. 5 contaminated corneas were used for penetrating keratoplasty; although four out of five (80%) had not been given antifungal drugs during more than 6 months following-up period, none of the recipients was infected with a graft. Donor age (P = 0.839), gender (P = 0.062), procurement sites (P = 0.713) and cause of death (P = 0.711) had no statistically significant influence on the contamination rate. All donor corneas have a possibility of microbiological contamination. Strict tissue preservation protocol but not antifungal drugs following keratoplasty seems necessary to prevent graft infection.


Assuntos
Córnea/microbiologia , Transplante de Córnea/métodos , Preservação de Órgãos/efeitos adversos , Preservação de Órgãos/métodos , Manejo de Espécimes/efeitos adversos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Bactérias , Criança , Pré-Escolar , Meios de Cultura , Bancos de Olhos , Feminino , Fungos , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Doadores de Tecidos , Preservação de Tecido/métodos , Adulto Jovem
8.
Biol Reprod ; 98(3): 286-298, 2018 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-29373650

RESUMO

In 2011, DEHP (plasticizer) was reported to illegally be added in food and beverage products in Taiwan, which caused great concerns about food safety worldwide. DHEP has multiple toxic effects to human and animals such as endocrine disruption, cardiotoxicity, reproductive function, and development defects. However, the toxic effects of DEHP on mammalian oocyte quality are still unclear. Since MEHP is the active metabolite of DEHP in vivo, in this study we used porcine oocyte as model to explore the effects of MEHP on oocyte maturation and we also studied the effects of melatonin administration on MEHP exposure-induced meiosis defects. Our results showed that exposure to MEHP significantly decreased the polar body extrusion rate in porcine oocytes. Further study showed that cell cycle progression, meiotic spindle organization, and actin assembly were all disturbed after MEHP exposure. Moreover, the DNA and histone methylation levels were also affected, showing with altered 5mC and H3K4me2 levels. These results indicated that MEHP affected porcine oocyte maturation, while MEHP exposure-induced meiotic defects were all remarkably ameliorated by the administration of melatonin in porcine oocytes. We further tried to explore the causes of MEHP toxicity on oocytes, and we found that MEHP exposure resulted in significant elevations of oxidative stress and induced early apoptosis as well as elevated autophagy, while melatonin administration could reduce these. Taken together, our results indicated that MEHP exposure induced deterioration of oocyte quality, whereas melatonin supplement showed amelioration on oocyte maturation through its rescue effects on oocyte oxidative stress-mediated apoptosis and autophagy.


Assuntos
Antioxidantes/farmacologia , Dietilexilftalato/análogos & derivados , Meiose/efeitos dos fármacos , Melatonina/farmacologia , Oócitos/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Plastificantes/farmacologia , Animais , Apoptose/efeitos dos fármacos , Autofagia/efeitos dos fármacos , Ciclo Celular/efeitos dos fármacos , Citoesqueleto/efeitos dos fármacos , Citoesqueleto/metabolismo , Dietilexilftalato/farmacologia , Feminino , Oócitos/metabolismo , Oogênese/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Suínos
9.
Planta Med ; 82(4): 362-70, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26829520

RESUMO

Angelicae Sinensis Radix is commonly used in traditional Chinese medicine. Pharmacological studies show that Angelicae Sinensis Radix has clear anticoagulant activity. Therefore, in this study, the anticoagulant activity of crude Angelicae Sinensis Radix extracts was investigated by measuring the thrombin times of the extracts. The results revealed that the petroleum ether-soluble fraction of Angelicae Sinensis Radix exhibited significant anticoagulant activity in vitro, and 26 compounds were characterized by high-performance liquid chromatography with diode array detection combined with electrospray ionization ion trap time-of-flight multistage mass spectrometry. In addition, 5 prototype constituents, 24 in vivo metabolites in rat urine and 7 prototype constituents, and 9 in vitro metabolites in the rat hepatic S9 incubation system of the petroleum ether-soluble fraction were tentatively identified. All metabolites were found from Angelicae Sinensis Radix for the first time. Among them, 13 (three ferulic acid-related constituents, six senkyunolide D-related constituents, and four senkyunolide F-related constituents) were identified as new metabolites (new compounds). This study is the first to qualitatively characterize the chemical constituents of the potent anticoagulative extract of Angelicae Sinensis Radix and to explore its metabolism. The result is a notable improvement in the discovery of Angelicae Sinensis Radix metabolites, and it provides the chemical basis for the effective forms and pharmacodynamic substances (prototypes, metabolites, or both) of the anticoagulant activity of Angelicae Sinensis Radix.


Assuntos
Angelica sinensis/química , Anticoagulantes/química , Medicamentos de Ervas Chinesas/química , Animais , Anticoagulantes/metabolismo , Anticoagulantes/farmacologia , China , Cromatografia Líquida de Alta Pressão/métodos , Medicamentos de Ervas Chinesas/metabolismo , Medicamentos de Ervas Chinesas/farmacologia , Masculino , Raízes de Plantas/química , Coelhos , Ratos , Ratos Sprague-Dawley , Espectrometria de Massas por Ionização por Electrospray/métodos
10.
Zhongguo Zhong Yao Za Zhi ; 40(24): 4873-83, 2015 Dec.
Artigo em Zh | MEDLINE | ID: mdl-27245037

RESUMO

This study is to establish the characteristic HPLC chromatogram of phenols in Ephedrae Herba, from which to pick out the marker peaks, followed by the analysis of the regularity of their distribution and content in the herbaceous stems of Ephedra sinica, E. intermedia and E. equisetina. The HPLC-DAD method for the characteristic chromatogram as well as quantitative analysis was established. The separation was carried out on a YMC-Pack ODS-A column (4.6 mm x 250 mm, 5 µm), eluted with the mobile phases as 0.01% formic acid aqueous solution (A) and acetonitrile (B) in a linear gradient (0-10 min, 17% B; 10-25 min, 17%-19% B; 25- 33 min, 19%-48% B; 33-35 min, 48%-51% B; 35-44 min, 51% B). The flow rate was kept at 1.0 mL · min⁻¹. The column tem- perature was 40 °C, and the detection wavelength was set at 350 nm (0-16 min) and 330 nm (16-44 min). Forty-six batches of collected samples from three official origins of Ephedrae Herba were detected, whose liquid chromatograms proven to be helpful to the differentiation of different origins. With principal component analysis and the analysis of distribution of peak area, twelve key peaks from the chromatogram were discussed in details on their contributions to the characteristics and differences of three official origins of the herb: peak area of peak 10, 11, 12 were found out to be significantly higher in E. equisetina than in other two origins, whose sum (higher than 146 mAU in E. equisetina) was useful for the discrimination between E. equisetina and the other two origins; peak area of 1 and 4 were respectively higher in E. sinica and E. intermedia than in other official origins, indicating their important effect on the differen- tiation of corresponding origins; peak 8 and 9 were picked out as two characteristic common peaks in three official origins of the herb, whose peak area showed little difference among different origins; further, peak area of other key peaks in the chromatogram also showed some difference among three origins, which make contributions to the differentiation of origins as well. Then, four phenols as 2"-O-α- L-rhamnosyl-isovitexin (1), vitexin (2), pollenitin B (5) and herbacetin-7-O-ß-D-glucoside (6) were quantitative analyzed with the above-mentioned method, with good linear relationship and accuracy (recoveries in a range of 97.8%-102.5%). The content of the four phenols were firstly reported in Ephedrae Herba from official origins, which were respectively trace-1.55 (1), trace-0.160 (2), trace-0.284 (5) and trace-0.620 (6) mg · g⁻¹ in all of the tested samples. In addition, the content of these phenols showed differences in three official origins, especially 1, whose content in E. sinica [(0.670 ± 0.88) mg ± g⁻¹] were significantly higher than in other two origins (lower than 0.16 mg ± g⁻¹ besides sample Ei-060630-2-2), and 6, whose average content in E. equisetina [(0.260 ± 0.039 2) mg · g⁻¹] were twice as high as in E. sinica [(0.120 ± 0.270) mg · g⁻¹] and E. intermedia [(0.136 ± 0.485) mg g⁻¹], indicating the important effects of the two constituents on the differentiation among three official origins of the herb. The method established for the characteristic HPLC chromatogram and quantitative analysis of phenols was simple and accurate, and the marker constituents selected may provide new guides for the discrimination of official origins as well as the improvement of quality criteria of EphedraeHerba.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Ephedra/química , Fenóis/análise
11.
Biomed Chromatogr ; 28(3): 401-11, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24105958

RESUMO

(+)-Catechin, a potential beneficial compound to human health, is widely distributed in plants and foods. A high-performance liquid chromatography with diode array detector and combined with electrospray ionization ion trap time-of-flight multistage mass spectrometry method was applied to profile and identify the metabolites of (+)-catechin in rats and to study the distribution of these metabolites in rat organs for the first time. In total, 51 phase II metabolites (44 new) and three phase I metabolites were tentatively identified, comprising 16 (+)-catechin conjugates, 14 diarylpropan-2-ol metabolites, 6 phenyl valerolactone metabolites and 18 aromatic acid metabolites. Further, 19 phase II metabolites were new compounds. The in vivo metabolic reactions of (+)-catechin in rats were found to be ring-cleavage, sulfation, glucuronidation, methylation, dehydroxylation and dehydrogenation. The numbers of detected metabolites in urine, plasma, small intestine, kidney, liver, lung, heart, brain and spleen were 53, 23, 27, 9, 7, 5, 3, 2 and 1, respectively. This indicated that small intestine, kidney and liver were the major organs for the distribution of (+)-catechin metabolites. In addition, eight metabolites were found to possess bioactivities according to literature. These results are very helpful for better comprehension of the in vivo metabolism of (+)-catechin and its pharmacological actions, and also can give strong indications on the effective forms of (+)-catechin in vivo.


Assuntos
Catequina , Cromatografia Líquida de Alta Pressão/métodos , Espectrometria de Massas por Ionização por Electrospray/métodos , Animais , Catequina/sangue , Catequina/metabolismo , Catequina/farmacocinética , Catequina/urina , Masculino , Redes e Vias Metabólicas , Modelos Moleculares , Ratos , Ratos Sprague-Dawley , Distribuição Tecidual
12.
Int Immunopharmacol ; 140: 112816, 2024 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-39083930

RESUMO

Vaccines represent a significant milestone in the history of human medical science and serve as the primary means for controlling infectious diseases. In recent years, the geographical distribution of Japanese encephalitis viruses (JEV) of various genotypes has become increasingly complex, which provides a rationale for the development of safer and more effective vaccines. The advent of subunit and nucleic acid vaccines, especially propelled by advancements in genetic engineering since the 1980s, has accelerated the application of novel adjuvants. These novel vaccine adjuvants have diversified into toll-like receptor (TLR) agonists, complex adjuvants, nanoparticles and so on. However, the efficacy of adjuvant combinations can vary depending on the host system, disease model, or vaccine formulation, sometimes resulting in competitive or counteractive effects. In our previous study, we constructed a pJME-LC3 chimeric DNA vaccine aimed at inducing an immune response through autophagy induction. Building on this, we investigated the impact of the TLR7/8 agonist imiquimod (IMQ) and the TLR9 agonist CpG ODN 1826 as adjuvants on the immunogenicity of the Japanese encephalitis chimeric DNA vaccine. Our findings indicate that the combination of the pJME-LC3 vaccine with IMQ and CpG ODN 1826 adjuvants enhanced the innate immune response, promoting the maturation and activation of antigen-presenting cells in the early immune response. Furthermore, it played a regulatory and optimizing role in subsequent antigen-specific immune responses, resulting in effective cellular and humoral immunity and providing prolonged immune protection. The synergistic effect of IMQ and CpG ODN 1826 as adjuvants offers a novel approach for the development of Japanese encephalitis nucleic acid vaccines.

13.
Int J Surg Case Rep ; 114: 109128, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38091707

RESUMO

INTRODUCTION: Aspergillus endocarditis is a rare fungal infection associated with a poor prognosis. Most cases of Aspergillus endocarditis involve prosthetic valves, with native valve involvement being rarely reported. CASE PRESENTATION: A 53-year-old asian female patient presented with fever, chills, dyspnea, generalized fatigue, and significant weight loss one month after undergoing left lower lobectomy for a pulmonary abscess. Echocardiogram showed a large mobile vegetation with a broad base on the anterior leaflet of the mitral valve, resembling atrial myxoma. Despite negative blood cultures, circulating DNA of Aspergillus fumigatus was detected by metagenome Next Generation Sequencing, prompting the initiation of empiric antifungal therapy with voriconazole. Emergency surgery, involving thorough debridement and mitral valve replacement, was successfully performed. Indefinite fungal suppression therapy with oral voriconazole is continued to mitigate the risk of recurrence. The patient survived with no signs of Aspergillus disease recurrence for four years. CLINICAL DISCUSSION: Diagnosis of Aspergillus endocarditis requires a high index of suspicion and is often delayed due to consistently negative results from blood cultures. Non-culture-based methods, particularly metagenome Next-Generation Sequencing, play a crucial role in early diagnosis and therapeutic decision-making. Surgical debridement and valve replacement are imperative for survival in cases of Aspergillus endocarditis. Voriconazole should be considered the primary fungicidal agent for its treatment. Moreover, lifelong fungal suppression therapy is strongly recommended for all survivors to ensure long-term survival and minimize the risk of recurrence. CONCLUSION: Despite grim prognosis associated with Aspergillus endocarditis, patients can attain long-term survival through meticulous surgical debridement and lifelong antifungal therapy.

14.
Adv Sci (Weinh) ; : e2401748, 2024 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-38994891

RESUMO

Persister cells (PS) selected for anticancer therapy have been recognized as a significant contributor to the development of treatment-resistant malignancies. It is found that imposing glutamine restriction induces the generation of PS, which paradoxically bestows heightened resistance to glutamine restriction treatment by activating the integrated stress response and initiating the general control nonderepressible 2-activating transcription factor 4-alanine, serine, cysteine-preferring transporter 2 (GCN2-ATF4-ASCT2) axis. Central to this phenomenon is the stress-induced ATF4 translational reprogramming. Unfortunately, directly targeting ATF4 protein has proven to be a formidable challenge because of its flat surface. Nonetheless, a G-quadruplex structure located within the promoter region of ATF4 (ATF4-G4) is uncovered and resolved, which functions as a transcriptional regulator and can be targeted by small molecules. The investigation identifies the natural compound coptisine (COP) as a potent binder that interacts with and stabilizes ATF4-G4. For the first time, the high-resolution structure of the COP-ATF4-G4 complex is determined. The formation of this stable complex disrupts the interaction between transcription factor AP-2 alpha (TFAP2A) and ATF4-G4, resulting in a substantial reduction in intracellular ATF4 levels and the eventual death of cancer cells. These seminal findings underscore the potential of targeting the ATF4-G4 structure to yield significant therapeutic advantages within the realm of persister cancer cells induced by glutamine-restricted therapy.

15.
Carbohydr Res ; 538: 109094, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38564900

RESUMO

Human diseases often correlate with changes in protein glycosylation, which can be observed in serum or plasma samples. N-glycosylation, the most common form, can provide potential biomarkers for disease prognosis and diagnosis. However, glycoproteins constitute a relatively small proportion of the total proteins in human serum and plasma compared to the non-glycosylated protein albumin, which constitutes the majority. The detection of microheterogeneity and low glycan abundance presents a challenge. Mass spectrometry facilitates glycoproteomics research, yet it faces challenges due to interference from abundant plasma proteins. Therefore, methods have emerged to enrich N-glycans and N-linked glycopeptides using glycan affinity, chemical properties, stationary phase chemical coupling, bioorthogonal techniques, and other alternatives. This review focuses on N-glycans and N-glycopeptides enrichment in human serum or plasma, emphasizing methods and applications. Although not exhaustive, it aims to elucidate principles and showcase the utility and limitations of glycoproteome characterization.


Assuntos
Glicopeptídeos , Glicoproteínas , Humanos , Glicopeptídeos/química , Glicoproteínas/química , Glicosilação , Espectrometria de Massas/métodos , Polissacarídeos
16.
Front Cardiovasc Med ; 10: 1033489, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36818352

RESUMO

Background: Late severe tricuspid regurgitation (TR) after left-side valve surgery (LSVS) is not uncommon. However, the tricuspid valve has been deemed the forgotten valve because the isolated TR is well tolerated with medication, and reoperation has a higher rate of adverse events. With the advancement of minimally invasive techniques, isolated tricuspid valve reoperation (ITVR) via totally endoscopy or transcatheter approach brings the tricuspid valve into spotlight. Our aim is to report the safety and efficacy of minimally invasive ITVR using endoscopic and transcatheter approaches. Methods: From October 2020 to October 2021, 21 patients with LSVS history and secondary massive TR underwent minimally invasive ITVR in our institution. Baseline characteristics, surgical outcomes and follow-up results were analyzed, and data between the totally endoscopy approach and the transcatheter approach were compared. Results: Of the 21 cases, totally endoscopic isolated tricuspid valve surgery (EITVS) accounts for 16 (76.2%) cases, with 14 tricuspid valvuloplasty cases, and 2 tricuspid valve replacement cases; the remaining 5 (23.8%) cases underwent transcatheter tricuspid valve replacement (TTVR). The mean age was (60.0 ± 8.4) years, with 15 (71.4%) being female. Minimally invasive ITVR procedures were 100% successfully performed in all patients without any perioperative mortality, sternotomy conversion, or reoperation. During the median follow-up of 16.8 months (IQR, 13.0-20.6 months), New York Heart Association Class improved significantly from baseline (P = 0.004). TR severity was significantly improved during postoperative and follow-up period (both P < 0.001). Compared with the EITVS group, the TTVR group had a higher clinical risk score [8.00 (8.00, 9.00) vs. 5.00 (3.25, 5.00), P = 0.001], but a higher success rate in reducing TR to less than grade 1+ (100 vs. 43.8%, P = 0.045) at follow-up. Conclusion: In our series, minimally invasive ITVR, including EITVS and TTVR, is a safe and feasible option for severe TR after LSVS, and presents excellent early outcomes in selected patients. TTVR is a reliable alternative for patients with high surgical risk. To improve the results of ITVR, it is necessary to improve patient's preoperative status or perform reoperation before the onset of significant right heart failure. Further studies with a larger sample size and a longer follow-up period are awaited.

17.
J Cardiothorac Surg ; 18(1): 161, 2023 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-37098556

RESUMO

OBJECTIVES: To compare the safety and efficacy of del-Nido cardioplegia (DNC) with traditional 4:1 cold blood cardioplegia (CBC) in coronary artery bypass grafting and/or valve surgeries in elderly patients. METHODS: The present study is a retrospective case-series study that included 302 consecutive patients aged 70 years and over who underwent on-pump valve surgery and/or coronary artery bypass graft (CABG). DNC was administered to 90 patients and CBC to 212 patients. After propensity-score matching, 89 pairs were compared. The safety and efficacy were analyzed between the two groups. RESULTS: The DNC group had a similar mortality (3.4% vs. 5.6%, OR = 0.79, P = 0.720) and extracorporeal membrane oxygenation (ECMO) implantation rate (1.1% vs. 2.2%, OR = 0.75, P = 1.000) to the CBC group, a lower incidence of postoperative intra-aortic balloon pump (IABP) implantation (1.1% vs. 9.0%, OR = 0.54, P = 0.034) and a higher left ventricular ejection fraction (LVEF) at discharge (60 (56-64) % vs. 57 (51-62)%, P = 0.007). The estimated glomerular filtration rate (eGFR) in the DNC group was higher when the patient was transferred to the intensive care unit (79.4 (65.0-94.3) ml/min/1.73m2 vs. 77.2 (59.8-88.7) ml/min/1.73m2, P = 0.014), but no significant differences were identified after 24 h. The serum lactate values of the DNC group were significantly lower than those of the CBC group (0 h: 2.7 (2.0-3.2) vs. 3.2 (2.4-4.4), P = 0.001; 3 h: 3.2 (2.0-4.8) vs. 4.8 (2.8-6.6), P < 0.001; 6 h: 3.5 (2.2-5.4) vs. 5.8 (3.4-8.4), P < 0.001; 9 h: 3.4 (2.0-7.0) vs. 5.5 (2.9-8.3), P = 0.005). There were no differences between the two groups in respect of lactate levels at 12 h and thereafter. Postoperative creatinine kinase-MB concentrations were similar between the two groups. CONCLUSIONS: Del-Nido cardioplegia is safe and effective in elderly patients undergoing CABG and/or valve surgery.


Assuntos
Soluções Cardioplégicas , Função Ventricular Esquerda , Idoso , Humanos , Idoso de 80 Anos ou mais , Estudos Retrospectivos , Pontuação de Propensão , Volume Sistólico , Parada Cardíaca Induzida/métodos , Lactatos
18.
Br J Pharmacol ; 180(24): 3175-3193, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37501645

RESUMO

BACKGROUND AND PURPOSE: Osteosarcoma, a primary malignant bone tumour prevalent among adolescents and young adults, remains a considerable challenge despite protracted progress made in enhancing patient survival rates over the last 40 years. Consequently, the development of novel therapeutic approaches for osteosarcoma is imperative. Sanguinarine (SNG), a compound with demonstrated potent anticancer properties against various malignancies, presents a promising avenue for exploration. Nevertheless, the intricate molecular mechanisms underpinning SNG's actions in osteosarcoma remain elusive, necessitating further elucidation. EXPERIMENTAL APPROACH: Single-stranded DNA-binding protein 1 (SSBP1) was screened out by differential proteomic analysis. Apoptosis, cell cycle, reactive oxygen species (ROS) and mitochondrial changes were assessed via flow cytometry. Western blotting and quantitative real-time reverse transcription PCR (qRT-PCR) were used to determine protein and gene levels. The antitumour mechanism of SNG was explored at a molecular level using chromatin immunoprecipitation (ChIP) and dual luciferase reporter plasmids. KEY RESULTS: Our investigation revealed that SNG exerted an up-regulated effect on SSBP1, disrupting mitochondrial function and inducing apoptosis. In-depth analysis uncovered a mechanism whereby SNG hindered the JAK/signal transducer and activator of transcription 3 (STAT3) signalling pathway, relieved the inhibitory effect of STAT3 on SSBP1 transcription, and inhibited the downstream PI3K/Akt/mTOR signalling axis, ultimately activating apoptosis. CONCLUSIONS AND IMPLICATIONS: The study delved further into elucidating the anticancer mechanism of SNG in osteosarcoma. Notably, we unravelled the previously undisclosed apoptotic potential of SSBP1 in osteosarcoma cells. This finding holds substantial promise in advancing the development of novel anticancer drugs and identification of therapeutic targets.


Assuntos
Neoplasias Ósseas , Osteossarcoma , Adolescente , Humanos , Fator de Transcrição STAT3/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Proteômica , Linhagem Celular Tumoral , Apoptose , Osteossarcoma/tratamento farmacológico , Osteossarcoma/genética , Osteossarcoma/metabolismo , Neoplasias Ósseas/tratamento farmacológico , Neoplasias Ósseas/genética , Neoplasias Ósseas/patologia , Proteínas de Ligação a DNA/genética , Regiões Promotoras Genéticas , Proliferação de Células , Proteínas Mitocondriais/metabolismo
19.
Front Med (Lausanne) ; 9: 964062, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36213642

RESUMO

Toxic epidermal necrolysis (TEN) and Stevens-Johnson syndrome (SJS) are acute inflammatory skin adverse reactions characterized by epidermal exfoliation and multi-site mucositis and are considered medical emergencies. The risk factors for SJS/TEN include immune disorders, malignancy, and genetic susceptibility. In most cases, medication is considered to be the leading cause of TEN. In addition, several studies suggest that infections, such as the herpes simplex virus, human immunodeficiency virus (HIV), Mycoplasma pneumoniae, streptococcus, and meningococcus infections, can trigger the occurrence of SJS/TEN. In this rare case, we share our experience managing TEN in a hepatitis A virus infection with an acute-on-chronic liver failure patient. A 38-year-old man was infected with hepatitis A virus on the basis of liver cirrhosis and progressed to acute-on-chronic liver failure. As the infection progressed, the target-like skin lesions accompanied by mucosal involvement worsened. The condition of the patient progressively worsened with a severe generalized rash, bullae, and epidermal detachment accompanied by severe erosive mucosal lesions. His skin detachment area gradually involved 30% of the body surface area (BSA), and the disease progressed to TEN. The intravenous infusion of corticosteroids alleviated the patient's hypersensitivity, and the patient obtained lasting remission without severe adverse reactions and complications.

20.
Front Aging Neurosci ; 14: 872134, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35547626

RESUMO

For decades, it has been widely believed that the blood-brain barrier (BBB) provides an immune privileged environment in the central nervous system (CNS) by blocking peripheral immune cells and humoral immune factors. This view has been revised in recent years, with increasing evidence revealing that the peripheral immune system plays a critical role in regulating CNS homeostasis and disease. Neurodegenerative diseases are characterized by progressive dysfunction and the loss of neurons in the CNS. An increasing number of studies have focused on the role of the connection between the peripheral immune system and the CNS in neurodegenerative diseases. On the one hand, peripherally released cytokines can cross the BBB, cause direct neurotoxicity and contribute to the activation of microglia and astrocytes. On the other hand, peripheral immune cells can also infiltrate the brain and participate in the progression of neuroinflammatory and neurodegenerative diseases. Neurodegenerative diseases have a high morbidity and disability rate, yet there are no effective therapies to stop or reverse their progression. In recent years, neuroinflammation has received much attention as a therapeutic target for many neurodegenerative diseases. In this review, we highlight the emerging role of the peripheral and central immune systems in neurodegenerative diseases, as well as their interactions. A better understanding of the emerging role of the immune systems may improve therapeutic strategies for neurodegenerative diseases.

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