Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 176
Filtrar
1.
Chem Rev ; 124(1): 164-209, 2024 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-38044580

RESUMO

The performance of a chemical reaction is critically dependent on the electronic and/or geometric structures of a material in heterogeneous catalysis. Over the past century, the Sabatier principle has already provided a conceptual framework for optimal catalyst design by adjusting the electronic structure of the catalytic material via a change in composition. Beyond composition, it is essential to recognize that the geometric atomic structures of a catalyst, encompassing terraces, edges, steps, kinks, and corners, have a substantial impact on the activity and selectivity of a chemical reaction. Crystal-phase engineering has the capacity to bring about substantial alterations in the electronic and geometric configurations of a catalyst, enabling control over coordination numbers, morphological features, and the arrangement of surface atoms. Modulating the crystallographic phase is therefore an important strategy for improving the stability, activity, and selectivity of catalytic materials. Nonetheless, a complete understanding of how the performance depends on the crystal phase of a catalyst remains elusive, primarily due to the absence of a molecular-level view of active sites across various crystal phases. In this review, we primarily focus on assessing the dependence of catalytic performance on crystal phases to elucidate the challenges and complexities inherent in heterogeneous catalysis, ultimately aiming for improved catalyst design.

2.
Chemistry ; 30(10): e202303476, 2024 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-38065837

RESUMO

The construction of an all-in-one catalyst, in which the photosensitizer and the transition metal site are close to each other, is important for improving the efficiency of metallaphotoredox catalysis. However, the development of convenient synthetic strategies for the precise construction of an all-in-one catalyst remains a challenging task due to the requirement of precise installation of the catalytic sites. Herein, we have successfully established a facile bottom-up strategy for the direct synthesis of Ni(II)-incorporated covalent organic framework (COF), named LZU-713@Ni, as a versatile all-in-one metallaphotoredox catalyst. LZU-713@Ni showed excellent activity and recyclability in the photoredox/nickel-catalyzed C-O, C-S, and C-P cross-coupling reactions. Notably, this catalyst displayed a better catalytic activity than its homogeneous analogues, physically mixed dual catalyst system, and, especially, LZU-713/Ni which was prepared through post-synthetic modification. The improved catalytic efficiency of LZU-713@Ni should be attributed to the implementation of bottom-up strategy, which incorporated the fixed, ordered, and abundant catalytic sites into its framework. This work sheds new light on the exploration of concise and effective strategies for the construction of multifunctional COF-based photocatalysts.

3.
Ann Hematol ; 103(7): 2257-2266, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38270644

RESUMO

To investigate the prognostic impact of serum beta-2 microglobulin (B2M) in adult lymphoma-associated hemophagocytic lymphohistiocytosis (HLH). The clinical and laboratory characteristics of 326 adult patients in a multicenter cohort with lymphoma-associated HLH with available baseline serum B2M levels were retrospectively analyzed. A total of 326 cases were included in this study, and the median serum B2M level was 5.19 mg/L. The optimal cut-off of serum B2M was 8.73 mg/L, and the cases with serum B2M level >8.73 mg/L were older and had a more advanced stage, lower levels of platelets, albumin, and fibrinogen, and higher creatinine level. The serum B2M >8.73 mg/L, creatinine ≥133 µmol/L, fibrinogen ≤1.5 g/L, agranulocytosis (<0.5 × 109/L), severe thrombocytopenia (<50 × 109/L), and high Epstein-Barr virus DNA copy number were found to have independent prognostic values in all patients, and the serum B2M >8.73 mg/L was also an independent prognostic factor in patients with creatinine <133 µmol/L. Finally, a prognostic scoring system was established based on independent prognostic factors of all patients and categorized the patients into three groups with significant prognostic differences. This study confirmed that the serum B2M level can be an independent prognostic factor in lymphoma-associated HLH and established a prognostic scoring system to predict patients' survival.


Assuntos
Linfo-Histiocitose Hemofagocítica , Linfoma , Microglobulina beta-2 , Humanos , Linfo-Histiocitose Hemofagocítica/sangue , Linfo-Histiocitose Hemofagocítica/diagnóstico , Linfo-Histiocitose Hemofagocítica/mortalidade , Linfo-Histiocitose Hemofagocítica/etiologia , Microglobulina beta-2/sangue , Feminino , Masculino , Pessoa de Meia-Idade , Adulto , Idoso , Estudos Retrospectivos , Prognóstico , Linfoma/sangue , Linfoma/diagnóstico , Linfoma/complicações , Linfoma/mortalidade , Idoso de 80 Anos ou mais , Adulto Jovem , Adolescente , Taxa de Sobrevida , Relevância Clínica
4.
Environ Res ; 258: 119456, 2024 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-38906445

RESUMO

Anaerobic biological treatment technology, especially denitrification and anaerobic ammonia oxidation (anammox) technology as mainstream process, played dominant role in the field of biological wastewater treatment. However, the above process was prone to sludge floating during high load operation and thereby affecting the efficient and stable operation of the system. Excessive production of extracellular polymeric substance (EPS) was considered to be the main reason for anaerobic granular sludge flotation, but the summaries in this area were not comprehensive enough. In this review, the potential mechanisms of denitrification and anammox sludge floatation were discussed from the perspective of granular sludge structural characteristics, nutrient transfer, and microbial flora change respectively, and the corresponding control strategies were also summarized. Finally, this paper indicated that future research on sludge flotation should focus on reducing the negative effects of EPS in sludge particles.

5.
J Clin Immunol ; 43(6): 1302-1310, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37093406

RESUMO

PURPOSE: To evaluate the role of circulating Epstein-Barr virus (EBV) DNA in lymphoma-associated hemophagocytic lymphohistiocytosis (HLH). METHODS: We conducted a retrospective cohort study to explore the clinical and prognostic significance of EBV DNA in lymphoma-associated HLH. We included adult patients with combined diagnoses of lymphoma and HLH from January 2010 and November 2022 by retrieving the medical record system. RESULTS: A total of 281 patients with lymphoma-associated HLH were identified. Elevated whole-blood EBV DNA was observed in 54.4% (153/281) of patients, and the median copy number was significantly higher in the T/NK-cell malignancies (199,500, interquartile range, 30,000-1,390,000) than that in the B-cell non-Hodgkin lymphoma (5520, interquartile range, 1240-28,400, P < 0.001). The optimum cutoff for predicting survival was 16,100 copies/mL. Compared to the patients with EBV DNA ≤ 16,100 copies/mL, those with EBV DNA > 16,100 copies/mL were younger and had more T/NK-cell malignancies, lower levels of neutrophils and fibrinogen, and higher levels of hemoglobin, alanine aminotransferase, aspartate aminotransferase, lactic dehydrogenase, and ß2-microglobulin. A higher load of EBV DNA (> 16,100 copies/mL), thrombocytopenia (< 100 × 109/L), neutropenia (< 1 × 109/L), hypofibrinogenemia (≤ 1.5 g/L), and elevated levels of creatinine (> 133 µmol/L) were independent adverse predictors of 60-day overall survival and overall survival. A prognostic index based on EBV DNA and the other four factors was established to categorize the patients into four groups with significantly different outcomes. CONCLUSION: Our study identified high EBV load as a risk factor for lymphoma-associated HLH and established a prognostic index to predict outcomes.


Assuntos
Infecções por Vírus Epstein-Barr , Linfo-Histiocitose Hemofagocítica , Linfoma , Adulto , Humanos , Linfo-Histiocitose Hemofagocítica/diagnóstico , Linfo-Histiocitose Hemofagocítica/complicações , Infecções por Vírus Epstein-Barr/complicações , Infecções por Vírus Epstein-Barr/diagnóstico , Herpesvirus Humano 4 , Prognóstico , Estudos Retrospectivos , Relevância Clínica , Linfoma/complicações , Linfoma/diagnóstico , DNA
6.
Mol Phylogenet Evol ; 189: 107914, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37666378

RESUMO

Phylogenetic studies in the phylogenomics era have demonstrated that reticulate evolution greatly impedes the accuracy of phylogenetic inference, and consequently can obscure taxonomic treatments. However, the systematics community lacks a broadly applicable strategy for taxonomic delimitation in groups characterized by pervasive reticulate evolution. The red-fruit genus, Stranvaesia, provides an ideal model to examine the influence of reticulation on generic circumscription, particularly where hybridization and allopolyploidy dominate the evolutionary history. In this study, we conducted phylogenomic analyses integrating data from hundreds of single-copy nuclear (SCN) genes and plastomes, and interrogated nuclear paralogs to clarify the inter/intra-generic relationship of Stranvaesia and its allies in the framework of Maleae. Analyses of phylogenomic discord and phylogenetic networks showed that allopolyploidization and introgression promoted the origin and diversification of the Stranvaesia clade, a conclusion further bolstered by cytonuclear and gene tree discordance. With a well-inferred phylogenetic backbone, we propose an updated generic delimitation of Stranvaesia and introduce a new genus, Weniomeles. This new genus is distinguished by its purple-black fruits, thorns trunk and/or branches, and a distinctive fruit core anatomy characterized by multilocular separated by a layer of sclereids and a cluster of sclereids at the top of the locules. Through this study, we highlight a broadly-applicable workflow that underscores the significance of reticulate evolution analyses in shaping taxonomic revisions from phylogenomic data.


Assuntos
Sonhos , Rosaceae , Filogenia , Rosaceae/genética
7.
Lipids Health Dis ; 22(1): 110, 2023 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-37525197

RESUMO

BACKGROUND: A previous study demonstrated that low-density lipoprotein cholesterol (LDL-C) is associated with hepatocellular carcinoma (HCC); however, the causality between them has not been proven due to conflicting research results and the interference of confounders. This study utilized Mendelian randomization (MR) to investigate the causal relationship between LDL-C and HCC and identify the mediating factors. METHODS: LDL-C, HCC, and coronary artery disease (CAD) genome-wide association study (GWAS) data were obtained from a public database. To investigate causality, inverse variance weighting (IVW) was the main analysis approach. MR‒Egger, simple mode, weighted median (WM), and weighted mode were employed as supplementary analytic methods. In addition, horizontal pleiotropy and heterogeneity were tested. To evaluate the stability of the MR results, a "leave-one-out" approach was used. Multivariate MR (MVMR) was utilized to correct the confounders that might affect causality, and mediation analysis was used to investigate the potential mediating effects. Finally, we used HCC risk to infer the reverse causality with LDL-C level. RESULTS: Random effects IVW results were (LDL-C-HCC: odds ratio (OR) = 0.703, 95% confidence interval (CI) = [0.508, 0.973], P = 0.034; CAD-HCC: OR = 0.722, 95% CI = [0.645, 0.808], P = 1.50 × 10-8; LDL-C-CAD: OR = 2.103, 95% CI = [1.862, 2.376], P = 5.65 × 10-33), demonstrating a causal link between LDL-C levels and a lower risk of HCC. Through MVMR, after mutual correction, the causal effect of LDL-C and CAD on HCC remained significant (P < 0.05). Through mediation analysis, it was proven that CAD mediated the causative connection between LDL-C and HCC, and the proportion of mediating effect on HCC was 58.52%. Reverse MR showed that HCC could affect LDL-C levels with a negative correlation (ORIVW = 0.979, 95% CI = [0.961, 0.997], P = 0.025). CONCLUSION: This MR study confirmed the causal effect between LDL-C levels and HCC risk, with CAD playing a mediating role. It may provide a new view on HCC occurrence and development mechanisms, as well as new metabolic intervention targets for treatment.


Assuntos
Carcinoma Hepatocelular , Doença da Artéria Coronariana , Neoplasias Hepáticas , Humanos , LDL-Colesterol/genética , Fatores de Risco , Carcinoma Hepatocelular/genética , Análise de Mediação , Triglicerídeos , Estudo de Associação Genômica Ampla , Análise da Randomização Mendeliana , HDL-Colesterol/genética , Neoplasias Hepáticas/genética , Polimorfismo de Nucleotídeo Único/genética
8.
Neoplasma ; 70(2): 260-271, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37226933

RESUMO

Metabolic reprogramming is a common feature of glioblastoma (GBM) progression and metastasis. Altered lipid metabolism is one of the most prominent metabolic alterations in cancer. Understanding the links between phospholipid remodeling and GBM tumorigenesis may help develop new anticancer strategies and improve treatments to overcome drug resistance. We used metabolomic and transcriptomic analyses to systematically investigate metabolic and molecular changes in low-grade glioma (LGG) and GBM. We then re-established the reprogrammed metabolic flux and membrane lipid composition in GBM based on metabolomic and transcriptomic analyses. By inhibiting Aurora A kinase via RNA interference (RNAi) and inhibitor treatment, we investigated the effect of Aurora A kinase on phospholipid reprogramming LPCAT1 enzyme expression and GBM cell proliferation in vitro and in vivo. We found that GBM displayed aberrant glycerophospholipid and glycerolipid metabolism compared with LGG. Metabolic profiling indicated that fatty acid synthesis and uptake for phospholipid synthesis were significantly increased in GBM compared to LGG. The unsaturated phosphatidylcholine (PC) and phosphatidylethanolamine (PE) levels were significantly decreased in GBM compared to LGG. The expression level of LPCAT1, which is required for the synthesis of saturated PC and PE, was upregulated in GBM, and the expression of LPCAT4, which is required for the synthesis of unsaturated PC and PE, was downregulated in GBM. Notably, the inhibition of Aurora A kinase by shRNA knockdown and treatment with Aurora A kinase inhibitors such as Alisertib, AMG900, or AT9283 upregulated LPCAT1 mRNA and protein expression in vitro. In vivo, the inhibition of Aurora A kinase with Alisertib increased LPCAT1 protein expression. Phospholipid remodeling and a reduction in unsaturated membrane lipid components were found in GBM. Aurora A kinase inhibition increased LPCAT1 expression and suppressed GBM cell proliferation. The combination of Aurora kinase inhibition with LPCAT1 inhibition may exert promising synergistic effects on GBM.


Assuntos
Glioblastoma , Glioma , Humanos , Glioblastoma/tratamento farmacológico , Fosfolipídeos , Aurora Quinase A , Lipídeos de Membrana , 1-Acilglicerofosfocolina O-Aciltransferase
9.
Biochem Genet ; 61(5): 2092-2115, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36943521

RESUMO

Immunogenic cell death (ICD) induces anti-tumor immunity and aids in dismantling the immunosuppressive immune microenvironment (TME), which belongs to a type of regulated cell death. The differentiation of gastric cancer (GC) subtypes and the discovery of prognostic biomarkers are crucial for its treatment because GC is a disease that is both highly heterogeneous and aggressive. However, although the induction of ICD in tumor cells is associated with a favorable prognosis, the exact mechanism of its role in GC remains unclear. Transcriptome profiling data and clinical data of GC patients were retrieved from The Cancer Genome Atlas (TCGA) database. Herein, patients were classified with the consensus clustering algorithm, and the associated biological functions and immune microenvironment infiltration were explored based on the expression of ICD-associated genes. A risk score signature consisting of 11 ICD-related genes was established via the least absolute shrinkage and selection operator regression (LASSO) method. We have retrieved similar studies in recent years and compared them with our study using the time-dependent receiver operating characteristic (ROC) curves. Gene set variation analysis (GSVA) and single sample gene set enrichment analysis (ssGSEA) were performed to explore the association between the signature and tumor microenvironment (TME). Two distinct subtypes associated with ICD in GC were identified, each with a different prognosis. The ICD-high expression subtype was associated with higher immune cell infiltration and a better prognosis. The ICD-related gene signature containing 11 genes (CGB5, Z84468.1, APOA5, EPHA8, CLEC18C, TLR7, MUC7, MUC15, CTLA4, CALB2, and UGT2B28), could independently and accurately predict the prognosis of GC. In this study, an ICD-based classification was conducted to assist in the diagnosis and personalized therapy for GC. The ICD-related genes risk score model was established to predict prognosis.


Assuntos
Neoplasias Gástricas , Humanos , Neoplasias Gástricas/genética , Morte Celular Imunogênica , Diferenciação Celular , Análise por Conglomerados , Microambiente Tumoral/genética , Mucinas
10.
Anal Chem ; 94(16): 6371-6379, 2022 04 26.
Artigo em Inglês | MEDLINE | ID: mdl-35426306

RESUMO

Although the CRISPR/Cas system has pioneered a new generation of analytical techniques, there remain many challenges in developing a label-free, accurate, and reliable CRISPR/Cas-based assay for reporting the levels of low abundance biomolecules in complex biological samples. Here, we reported a novel CRISPR-derived resonance Rayleigh scattering (RRS) amplification strategy and logical circuit based on a guanine nanowire (G-wire) assisted non-cross-linking hybridization chain reaction (GWancHCR) for label-free detection of lipopolysaccharide (LPS). In the presence of a target, the protospacer-adjacent motif-inserted aptamer is rationally designed to specifically combine with LPS rather than Cas12a, suppressing the trans-cleavage activity of CRISPR/Cas12a and retaining the reporter probes to trigger non-cross-linking aggregation. Owing to the automatic hybridization chain reaction (HCR), in the presence of Mg2+, the released G-quadruplex sequence aggregated to assemble the G-wire superstructure through non-cross-linking. As a result, a dramatically amplified RRS intensity is observed, allowing for reporting LPS levels in a low detection limit of 0.17 pg/mL and a wide linear range among 1.0-100.0 ng/mL. Moreover, this reaction event is capable of programming to perform classical Boolean logic tree analysis, including basic logic computing and complex integrated logic circuits. This study comprehensively analyzed with respect to information flow, matter (molecular events), and energy (RRS), revealing the potential promise in designing of molecular-level "Internet of Things", intelligent computing, and sensing systems.


Assuntos
Nanofios , Sistemas CRISPR-Cas/genética , Guanina , Lipopolissacarídeos , Lógica
11.
J Org Chem ; 87(10): 6927-6933, 2022 05 20.
Artigo em Inglês | MEDLINE | ID: mdl-35512323

RESUMO

Liriogerphines A-D (1-4, respectively), an unprecedented class of hybrids of germacranolide-type sesquiterpenoids and aporphine-type alkaloids, were isolated from the rare medicinal plant Liriodendron chinense. Their structures were elucidated by comprehensive spectroscopic analyses combined with electronic circular dichroism calculations and X-ray crystallographic data. Biosynthetically, an aza-Michael addition reaction is proposed to be involved in the assemblies of this class of hybrids. Compound 4 exhibited cytotoxicity against leukemia cells via inducing apoptosis and inhibiting Bcl-2 expression.


Assuntos
Alcaloides , Antineoplásicos , Liriodendron , Sesquiterpenos , Alcaloides/química , Alcaloides/farmacologia , China , Estrutura Molecular , Sesquiterpenos/química , Sesquiterpenos/farmacologia , Árvores
12.
Bioorg Chem ; 124: 105825, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35489273

RESUMO

A preliminary phytochemical investigation on the MeOH extract of the twigs and needles of Pseudotsuga gaussenii (a 'vulnerable' plant endemic to China) led to the isolation and characterization of 25 structurally diverse mono- and dimeric triterpenoids. 19 of them are previously undescribed, including eight cucurbitane-type triterpenoids (gaussenols A-H, 1-8, resp.), one serratene-type triterpene (gaussenol I, 9), and 10 triterpenic dimers (gaussenols J-S, 10-19, resp.). Their chemical structures were elucidated by means of spectroscopic data, some chemical transformations, the modified Mosher's method, and single crystal X-ray diffraction analyses. Compound 9 is the first 13R diastereoisomeric serratene-type triterpenoid derivative from nature. The unprecedented dimeric triterpenoids are constructed either through ester linkage (10-18) or via ether bond (19) among the side chains of same or different types of triterpenoid skeletons (e.g., cucurbitane-type, lanostane-type, and/or cycloartane-type). Compounds 9, 15, 21, and 25 exhibited inhibitory effects against the human protein tyrosine phosphatase 1B (PTP1B, a potential drug target for the treatment of type-II diabetes and obesity), with IC50 values of 3.1, 8.6, 9.0, and 5.6 µM, respectively. The interactions of the bioactive compounds with PTP1B were thereafter performed by employing molecular docking studies, with binding affinities ranging from - 6.9 to - 7.3 kcal/mol. The above findings could reveal the important role of protecting plant species diversity in support of chemical diversity and potential sources of new therapeutics.


Assuntos
Pseudotsuga , Traqueófitas , Triterpenos , Humanos , Simulação de Acoplamento Molecular , Estrutura Molecular , Proteína Tirosina Fosfatase não Receptora Tipo 1 , Triterpenos/química
13.
Bioorg Chem ; 120: 105630, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35091291

RESUMO

The ethanolic extracts of the dried flower buds of two Caprifoliaceae plants, Lonicera japonica and Abelia × grandiflora, showed considerable inhibitory activities against adenosine triphosphate (ATP)-citrate lyase (ACL), a new promising drug target for the treatment of metabolic disorders. Bioassay-guided purification in conjunction with HPLC-PDA profiling led to the isolation and characterization of thirty-five (1-35) and fourteen (1'-14') structurally diverse compounds from the above two plant extracts, respectively. Compounds 1-9 and 1'-6' are previously undescribed glycosides. Their structures were elucidated on the basis of spectroscopic data, electronic circular dichroism (ECD), and single crystal X-ray diffraction analyses. In particular, lonicejaposide A (1) has an unprecedented skeleton generated through the coupling of C-7 in secologanin with C-2'' in phenylacetaldehyde via an aldol condensation. Abeliflorosides A (1') and B (2') are hitherto unknown glycosides of triterpene and bisiridoid conjugates constructed through the formation of a 1,3-dioxane moiety. All the isolates were evaluated for their inhibitory activities against ACL. Compounds 9, 25-28, 31, 1', 2', and 14' displayed significant inhibitory effects, with IC50 values ranging from 0.1 to 14.2 µM. The interactions of selected compounds possessing different structure features (e.g., 9, 25, 31, and 2') with ACL were thereafter performed by employing molecular docking studies. In addition, compound 2', the most complex triterpene-bisiridoid conjugate glycoside reported herein, also inhibited acetyl-CoA carboxylase 1 (ACC1), with an IC50 value of 7.9 µM. The dried material of the flower buds of L. japonica (honeysuckle) is a well-known traditional oriental medicine (i.e., Flos Lonicerae Japonicae, FLJ) and has long been used in large quantities. The above findings not only provide new insights for the development of multipurpose utilization of FLJ in healthcare community, but also provide profitable clues indicating that the flower buds of A. × grandiflora might be a potential alternative to FLJ in the traditional Chinese medicine market.


Assuntos
Caprifoliaceae , Lonicera , Triterpenos , Trifosfato de Adenosina , Flores/química , Glicosídeos/química , Lonicera/química , Simulação de Acoplamento Molecular , Complexos Multienzimáticos , Oxo-Ácido-Liases
14.
Proc Natl Acad Sci U S A ; 116(20): 9820-9824, 2019 05 14.
Artigo em Inglês | MEDLINE | ID: mdl-31036653

RESUMO

Middle to Late Pleistocene human evolution in East Asia has remained controversial regarding the extent of morphological continuity through archaic humans and to modern humans. Newly found ∼300,000-y-old human remains from Hualongdong (HLD), China, including a largely complete skull (HLD 6), share East Asian Middle Pleistocene (MPl) human traits of a low vault with a frontal keel (but no parietal sagittal keel or angular torus), a low and wide nasal aperture, a pronounced supraorbital torus (especially medially), a nonlevel nasal floor, and small or absent third molars. It lacks a malar incisure but has a large superior medial pterygoid tubercle. HLD 6 also exhibits a relatively flat superior face, a more vertical mandibular symphysis, a pronounced mental trigone, and simple occlusal morphology, foreshadowing modern human morphology. The HLD human fossils thus variably resemble other later MPl East Asian remains, but add to the overall variation in the sample. Their configurations, with those of other Middle and early Late Pleistocene East Asian remains, support archaic human regional continuity and provide a background to the subsequent archaic-to-modern human transition in the region.


Assuntos
Fósseis , Crânio , China , Humanos , Dente
15.
Cancer Sci ; 111(7): 2400-2412, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32391593

RESUMO

Escape of cancer cells from chemotherapy is a problem in the management of cancer patients. Research on chemotherapy resistance has mainly focused on the heterogeneity of cancer cells, multiple gene mutations, and quiescence of malignant cancer cells. However, some studies have indicated that interactions between cancer cells and vascular cells promote resistance to chemotherapy. Here, we established mouse leukemia models using the cell lines THP-1 or MEG-1. These were derived from acute and chronic myeloid leukemias, respectively, and highly expressed DNA replication factor PSF1, a member of the GINS complex. We found that, after anti-cancer drug administration, surviving GFP-positive leukemia cells in the bone marrow were located adjacent to blood vessels, as previously reported in a subcutaneous solid tumor transplantation model. Treating THP-1 and MEG-1 cells with anti-cancer drugs in vitro revealed that those most strongly expressing PSF1 were most chemoresistant, suggesting that PSF1 induces not only cell cycle progression but also facilitates cell survival. Indeed, when PSF1 expression was suppressed by shRNA, the growth rate was reduced and cell death was enhanced in both cell lines. Furthermore, PSF1 knockdown in leukemia cells led to a change in their location at a distance from the blood vessels in a bone marrow transplantation model. These findings potentially reflect a mechanism of escape of leukemic cells from chemotherapy and suggest that PSF1 may be a possible therapeutic target to enhance the effect of chemotherapy.


Assuntos
Membro 2 da Subfamília B de Transportadores de Cassetes de Ligação de ATP/genética , Ciclo Celular/genética , Resistencia a Medicamentos Antineoplásicos/genética , Expressão Gênica , Leucemia/genética , Membro 2 da Subfamília B de Transportadores de Cassetes de Ligação de ATP/metabolismo , Animais , Antineoplásicos/farmacologia , Pontos de Checagem do Ciclo Celular/genética , Linhagem Celular Tumoral , Proliferação de Células , Modelos Animais de Doenças , Regulação Neoplásica da Expressão Gênica , Humanos , Camundongos , Camundongos Knockout , Ensaios Antitumorais Modelo de Xenoenxerto
16.
Fish Shellfish Immunol ; 103: 277-284, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32439510

RESUMO

Whey acidic protein domain (WAPD) occurs in a variety of proteins in animals and many of WAPD-containing proteins are involved in immunity. In the present study, a novel protein containing three WAPDs was identified from the weather loach, Misgurnus anguillicaudatus, designated as MaTWD. MaTWD share high identity with TWDs from fish but low identity with TWDs from other animal phyla. MaTWD transcripts mainly distributed in gills and head kidney responded to bacterial challenge with significant upregulation. In vitro assay with recombinant MaTWD protein revealed that MaTWD had antiprotease activity against bacterial proteases. Moreover, MaTWD exhibited bacterial binding capacity and antimicrobial activity. Most importantly, exogenous MaTWD protected loach against bacterial infection by reducing loach mortality. We infer that MaTWD participates in the antibacterial immunity of loach via its antiprotease and antimicrobial activities.


Assuntos
Cipriniformes/genética , Cipriniformes/imunologia , Doenças dos Peixes/imunologia , Proteínas de Peixes/genética , Proteínas de Peixes/imunologia , Regulação da Expressão Gênica/imunologia , Imunidade/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Proteínas de Peixes/química , Perfilação da Expressão Gênica/veterinária , Bactérias Gram-Negativas/fisiologia , Infecções por Bactérias Gram-Negativas/imunologia , Infecções por Bactérias Gram-Negativas/veterinária , Bactérias Gram-Positivas/fisiologia , Infecções por Bactérias Gram-Positivas/imunologia , Infecções por Bactérias Gram-Positivas/veterinária , Filogenia , Domínios Proteicos/imunologia , Alinhamento de Sequência/veterinária
17.
Bioorg Chem ; 105: 104445, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33197848

RESUMO

Rare and endangered plants (REPs) and their associated endophytes survived in unique habitats are promising sources for natural product-derived drug discovery. In this study, six new (cephaloverines A-F, 1-6, resp.) and 16 known (11-26) cephalotaxine-type alkaloids, together with three new (oliverbiflavones A-C, 7-9, resp.) and 11 known (27-37) biflavonoids were isolated and characterized from the twigs and leaves of Cephalotaxus oliveri, an endangered plant endemic to China. Meanwhile, a preliminary investigation on the secondary metabolites from a selected fungal endophyte (i.e., Alternaria alternate Y-4-2) associated with the title plant led to the isolation of 21 structurally distinct polyketides including one new dimeric xanthone (10). The new structures (1-10) with the absolute configurations were determined by detailed spectroscopic analyses, electronic circular dichroism (ECD) or Na2MoO4-induced ECD, the modified Mosher's method, and some chemical transformations. Compounds 1-4 are the first representatives of naturally occurring N-oxides of cephalotaxine esters, while compounds 7-9 have a special structural feature of having a C-methylated biflavonoid skeleton. The Cephalotaxus alkaloids with ester side-chains at C-3 (1-6, 13-22, and 26) and four biflavonoids (27-29 and 34) were found to show pronounced cytotoxicities against a small panel of human cancer cell lines (A549, NCI-H460, HL60, NCI-H929, and RPMI-8226), with IC50 values mainly ranging from 0.003 to 9.34 µM. The most potent compound, deoxyharringtonine (16), generally exhibited IC50 values less than 10 nM. The structure-activity relationship (SAR) of the aforementioned Cephalotaxus alkaloids was briefly discussed.


Assuntos
Alternaria/efeitos dos fármacos , Antineoplásicos/isolamento & purificação , Biflavonoides/isolamento & purificação , Cephalotaxus/química , Folhas de Planta/química , Antineoplásicos/farmacologia , Biflavonoides/farmacologia , Linhagem Celular Tumoral , Ensaios de Seleção de Medicamentos Antitumorais , Endófitos , Mepesuccinato de Omacetaxina/química , Humanos , Estrutura Molecular , Policetídeos/química , Metabolismo Secundário , Relação Estrutura-Atividade , Xantonas/química
18.
J Fish Dis ; 43(12): 1531-1539, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32924173

RESUMO

C-type lectins are carbohydrate-binding proteins that play important roles in immunity by serving as pattern recognition receptors. In the present study, a novel nattectin-like C-type lectin was obtained from the weather loach, Misgurnus anguillicaudatus, designated as MaCTL. MaCTL encodes a peptide with 165 amino acids, with a signal peptide and a single C-type lectin domain (CTLD), containing a galactose-specific QPD motif and a conserved Ca2+ -binding site. Transcripts of MaCTL were significantly upregulated after immune challenge with its pathogen A. hydrophila. In vitro assays with recombinant MaCTL protein revealed that it exhibited hemagglutinating and bacterial agglutinating activities, in a Ca2+ -dependent manner. MaCTL was found to bind to a wide range of bacteria, as well as bind to bacterial polysaccharides LPS and PGN. Moreover, MaCTL displayed antimicrobial activity by inhibiting the growth of bacteria. These results collectively suggest that MaCTL is involved in the antibacterial defence of weather loach.


Assuntos
Cipriniformes/imunologia , Doenças dos Peixes/imunologia , Lectinas Tipo C/imunologia , Aeromonas hydrophila/efeitos dos fármacos , Aglutinação , Sequência de Aminoácidos , Animais , Cipriniformes/genética , Proteínas de Peixes/química , Proteínas de Peixes/genética , Proteínas de Peixes/imunologia , Perfilação da Expressão Gênica , Infecções por Bactérias Gram-Negativas/imunologia , Lectinas Tipo C/química , Lectinas Tipo C/genética , Proteínas Recombinantes , Alinhamento de Sequência
19.
J Biol Chem ; 293(15): 5572-5584, 2018 04 13.
Artigo em Inglês | MEDLINE | ID: mdl-29475941

RESUMO

Recombinant therapeutic proteins are becoming very important pharmaceutical agents for treating intractable diseases. Most biopharmaceutical proteins are produced in mammalian cells because this ensures correct folding and glycosylation for protein stability and function. However, protein production in mammalian cells has several drawbacks, including heterogeneity of glycans attached to the produced protein. In this study, we established cell lines with high-mannose-type N-linked, low-complexity glycans. We first knocked out two genes encoding Golgi mannosidases (MAN1A1 and MAN1A2) in HEK293 cells. Single knockout (KO) cells did not exhibit changes in N-glycan structures, whereas double KO cells displayed increased high-mannose-type and decreased complex-type glycans. In our effort to eliminate the remaining complex-type glycans, we found that knocking out a gene encoding the endoplasmic reticulum mannosidase I (MAN1B1) in the double KO cells reduced most of the complex-type glycans. In triple KO (MAN1A1, MAN1A2, and MAN1B1) cells, Man9GlcNAc2 and Man8GlcNAc2 were the major N-glycan structures. Therefore, we expressed two lysosomal enzymes, α-galactosidase-A and lysosomal acid lipase, in the triple KO cells and found that the glycans on these enzymes were sensitive to endoglycosidase H treatment. The N-glycan structures on recombinant proteins expressed in triple KO cells were simplified and changed from complex types to high-mannose types at the protein level. Our results indicate that the triple KO HEK293 cells are suitable for producing recombinant proteins, including lysosomal enzymes with high-mannose-type N-glycans.


Assuntos
Expressão Gênica , Técnicas de Silenciamento de Genes , Complexo de Golgi/enzimologia , Manosidases , Glicosilação , Complexo de Golgi/genética , Células HEK293 , Humanos , Manosidases/genética , Manosidases/metabolismo , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/genética
20.
Chemistry ; 24(41): 10296-10299, 2018 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-29697162

RESUMO

A new 3D framework {[Eu2 Cu(IN)5 (CO3 )(H2 O)] ⋅3 H2 O}n  (1) was obtained and structurally characterized, containing CuI and an unusual lanthanide duplex chain. The luminescent explorations of compound 1 suggest that 1 could emit the characteristic emission of CuI , and 1 can act as the luminescent sensor of ClO- with the detection limit of 10-5  m. Notably, 1 represents the first example of MOF-based sensor for detecting ClO- .

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA