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1.
Eur J Med Chem ; 270: 116393, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38588626

RESUMO

Estrogen receptor alpha (ERα), a nuclear transcription factor, is a well-validated therapeutic target for more than 70% of all breast cancers (BCs). Antagonizing ERα either by selective estrogen receptor modulators (SERMs) or selective estrogen receptor degraders (SERDs) forms the foundation of endocrine therapy and has achieved great success in the treatment of ERα positive (ERα+) BCs. Unfortunately, despite initial effectiveness, endocrine resistance eventually emerges in up to 30% of ERα+ BC patients and remains a significant medical challenge. Several mechanisms implicated in endocrine resistance have been extensively studied, including aberrantly activated growth factor receptors and downstream signaling pathways. Hence, the crosstalk between ERα and another oncogenic signaling has led to surge of interest to develop combination therapies and dual-target single agents. This review briefly introduces the synergisms between ERα and another anticancer target and summarizes the recent advances of ERα-based dual-targeting inhibitors from a medicinal chemistry perspective. Accordingly, their rational design strategies, structure-activity relationships (SARs) and biological activities are also dissected to provide some perspectives on future directions for ERα-based dual target drug discovery in BC therapy.


Assuntos
Neoplasias da Mama , Humanos , Feminino , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/metabolismo , Receptor alfa de Estrogênio/metabolismo , Receptores de Estrogênio/metabolismo , Antagonistas de Estrogênios/farmacologia , Moduladores Seletivos de Receptor Estrogênico/farmacologia , Resistencia a Medicamentos Antineoplásicos
2.
Microbiol Spectr ; : e0381123, 2024 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-38647341

RESUMO

In the nitrogen biogeochemical cycle, the reduction of nitrous oxide (N2O) to N2 by N2O reductase, which is encoded by nosZ gene, is the only biological pathway for N2O consumption. In this study, we successfully isolated a strain of denitrifying Paracoccus denitrificans R-1 from sewage treatment plant sludge. This strain has strong N2O reduction capability, and the average N2O reduction rate was 5.10 ± 0.11 × 10-9 µmol·h-1·cell-1 under anaerobic condition in a defined medium. This reduction was accompanied by the stoichiometric consumption of acetate over time when N2O served as the sole electron acceptor and the reduction can yield energy to support microbial growth, suggesting that microbial N2O reduction is related to the energy generation process. Genomic analysis showed that the gene cluster encoding N2O reductase of P. denitrificans R-1 was composed of nosR, nosZ, nosD, nosF, nosY, nosL, and nosZ, which was identified as that in other strains in clade I. Respiratory inhibitors test indicated that the pathway of electron transport for N2O reduction was different from that of the traditional electron transport chain for aerobic respiration. Cu2+, silver nanoparticles, O2, and acidic conditions can strongly inhibit the reduction, whereas NO3- or NH4+ can promote it. These findings suggest that modular N2O reduction of P. denitrificans R-1 is linked to the electron transport and energy conservation, and dissimilatory N2O reduction is a form of microbial anaerobic respiration. IMPORTANCE: Nitrous oxide (N2O) is a potent greenhouse gas and contributor to ozone layer destruction, and atmospheric N2O has increased steadily over the past century due to human activities. The release of N2O from fixed N is almost entirely controlled by microbial N2O reductase activities. Here, we investigated the ability to obtain energy for the growth of Paracoccus denitrificans R-1 by coupling the oxidation of various electron donors to N2O reduction. The modular N2O reduction process of denitrifying microorganism not only can consume N2O produced by itself but also can consume the external N2O generated from biological or abiotic pathways under suitable condition, which should be critical for controlling the release of N2O from ecosystems into the atmosphere.

3.
J Med Chem ; 67(7): 5567-5590, 2024 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-38512060

RESUMO

Androgen receptor (AR) has been extensively established as a potential therapeutic target for nearly all stages of prostate cancer (PCa). However, acquired resistance to AR-targeted drugs inevitably develops and severely limits their clinical efficacy. Particularly, there currently exists no efficient treatment for patients expressing the constitutively active AR splice variants, such as AR-V7. Herein, we report the structure-activity relationship studies of 55 N-heterocycle-substituted hydantoins, which identified the structural motifs required for AR/AR-V7 degradation. Among them, the most potent compound 27c exhibited selective AR/AR-V7 degradation over other hormone receptors and excellent antiproliferative activities in LNCaP and 22RV1 cells. RNA sequence analysis confirmed that 27c effectively suppressed transcriptional activity of the AR signaling pathway. Importantly, 27c demonstrated potent antitumor efficacy in an enzalutamide-resistant 22RV1 xenograft model. These results highlight the potential of 27c as a promising dual AR/AR-V7 degrader for overcoming drug resistance in advanced PCa expressing AR splice variants.


Assuntos
Neoplasias de Próstata Resistentes à Castração , Receptores Androgênicos , Masculino , Humanos , Receptores Androgênicos/metabolismo , Neoplasias de Próstata Resistentes à Castração/tratamento farmacológico , Linhagem Celular Tumoral , Transdução de Sinais , Relação Estrutura-Atividade , Nitrilas/farmacologia , Resistencia a Medicamentos Antineoplásicos
4.
Sci Rep ; 14(1): 6814, 2024 03 21.
Artigo em Inglês | MEDLINE | ID: mdl-38514736

RESUMO

The present study aims to assess the treatment outcome of patients with diabetes and tuberculosis (TB-DM) at an early stage using machine learning (ML) based on electronic medical records (EMRs). A total of 429 patients were included at Chongqing Public Health Medical Center. The random-forest-based Boruta algorithm was employed to select the essential variables, and four models with a fivefold cross-validation scheme were used for modeling and model evaluation. Furthermore, we adopted SHapley additive explanations to interpret results from the tree-based model. 9 features out of 69 candidate features were chosen as predictors. Among these predictors, the type of resistance was the most important feature, followed by activated partial throm-boplastic time (APTT), thrombin time (TT), platelet distribution width (PDW), and prothrombin time (PT). All the models we established performed above an AUC 0.7 with good predictive performance. XGBoost, the optimal performing model, predicts the risk of treatment failure in the test set with an AUC 0.9281. This study suggests that machine learning approach (XGBoost) presented in this study identifies patients with TB-DM at higher risk of treatment failure at an early stage based on EMRs. The application of a convenient and economy EMRs based on machine learning provides new insight into TB-DM treatment strategies in low and middle-income countries.


Assuntos
Diabetes Mellitus , Humanos , Comorbidade , Falha de Tratamento , Registros Eletrônicos de Saúde , Aprendizado de Máquina
5.
Appl Environ Microbiol ; 90(4): e0228423, 2024 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-38445904

RESUMO

Halocins are antimicrobial peptides secreted by haloarchaea capable of inhibiting the growth of other haloarchaea or bacteria. Halocin H4 (HalH4) is secreted by the model halophilic archaeon Haloferax mediterranei ATCC 33500. Despite attempts to express halH4 heterologously in Escherichia coli and subsequent careful renaturation procedures commonly employed for haloarchaeal proteins, no active halocin was obtained. However, it was discovered that the antihaloarchaeal activity of this halocin could be activated through cleavage by halolysin R4 (HlyR4), a serine protease also secreted by Hfx. mediterranei ATCC 33500. Replacement of the cysteine at the number 115 amino acid with glycine and deletion of the internal trans-membrane region (15 aa) markedly abolished HalH4's antihaloarchaeal activity. Compared to the N-terminus, the C-terminal amino acid sequence was found to be more crucial for HalH4 to exert its antihaloarchaeal activity. Mass spectrometry analysis revealed that the biologically active antihaloarchaeal peptide produced after hydrolytic cleavage by HlyR4 was the C-terminus of HalH4, suggesting a potential mechanism of action involving pore formation within competitor species' cell membranes. Taken together, this study offers novel insights into the interplay between halocins and secreted proteases, as well as their contribution to antagonistic interaction within haloarchaea. IMPORTANCE: The antihaloarchaeal function of halocin H4 (HalH4) can be activated by extracellular proteases from haloarchaea, as demonstrated in this study. Notably, we report the first instance of halocin activation through proteolytic cleavage, highlighting its significance in the field. The C-terminus of HalH4 (CTH4) has been identified as the antihaloarchaeal peptide present in hydrolysates generated by HlyR4. The CTH4 exhibited inhibitory activity against a range of haloarchaeal species (Haloarchaeobius spp., Haloarcula spp., Haloferax spp., Halorubellus spp., and Halorubrum spp.), as well as selected bacterial species (Aliifodinibius spp. and Salicola spp.), indicating its broad-spectrum inhibitory potential across domains. The encoding gene of halocin HalH4, halH4, from the model halophilic archaeon Haloferax mediterranei ATCC 33500 can be expressed in Escherichia coli without codon optimization.


Assuntos
Haloferax mediterranei , Haloferax , Serina Endopeptidases/metabolismo , Peptídeos/metabolismo , Haloferax/metabolismo , Escherichia coli/genética
6.
Nutrition ; 122: 112399, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38493542

RESUMO

OBJECTIVES: Systemic inflammation and skeletal muscle strength play crucial roles in the development and progression of cancer cachexia. In this study we aimed to evaluate the combined prognostic value of neutrophil-to-lymphocyte ratio (NLR) and handgrip strength (HGS) for survival in patients with cancer cachexia. METHODS: This multicenter cohort study involved 1826 patients with cancer cachexia. The NLR-HGS (NH) index was defined as the ratio of neutrophil-to-lymphocyte ratio to handgrip strength. Harrell's C index and receiver operating characteristic (ROC) curve analysis were used to assess the prognosis of NH. Kaplan-Meier analysis and Cox regression models were used to evaluate the association of NH with all-cause mortality. RESULTS: Based on the optimal stratification, 380 women (NH > 0.14) and 249 men (NH > 0.19) were classified as having high NH. NH has shown greater predictive value compared to other indicators in predicting the survival of patients with cancer cachexia according to the 1-, 3-, and 5-y ROC analysis and Harrell's C index calculation. Multivariate survival analysis showed that higher NH was independently associated with an increased risk of death (hazard ratio = 1.654, 95% confidence interval = 1.389-1.969). CONCLUSION: This study demonstrates that the NH index, in combination with NLR and HGS, is an effective predictor of the prognosis of patients with cancer cachexia. It can offer effective prognosis stratification and guidance for their treatment.


Assuntos
Neoplasias , Neutrófilos , Masculino , Humanos , Feminino , Caquexia/etiologia , Estudos de Coortes , Força da Mão , Linfócitos , Prognóstico , Neoplasias/complicações , Estudos Retrospectivos
7.
World J Clin Cases ; 12(6): 1150-1156, 2024 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-38464933

RESUMO

BACKGROUND: Giant congenital biliary dilation (CBD) is a rare condition observed in clinical practice. Infants born with this condition often experience a poor overall health status, and the disease progresses rapidly, leading to severe biliary obstruction, infections, pressure exerted by the enlarged CBD on abdominal organs, disturbances in the internal environment, and multiple organ dysfunction. The treatment of giant CBD using laparoscopy is challenging due to the high degree of variation in the shape of the bile duct and other organs, making it difficult to separate the bile duct wall from adjacent tissues or to control bleeding. CASE SUMMARY: Herein, we present the details of an 11-d-old male newborn who was diagnosed with giant CBD. The patient was admitted to the neonatal surgery department of our hospital due to a history of common bile duct cyst that was detected more than 3 mo ago, and also because the patient had been experiencing yellowish skin for the past 9 d. The abnormal echo in the fetal abdomen was first noticed by the patient's mother during a routine ultrasound examination at a local hospital, when the patient was at 24 wk + 6 d of pregnancy. This finding raised concerns about the possibility of congenital biliary dilatation (22 mm × 21 mm). Subsequent ultrasound examinations at different hospitals consistently confirmed the presence of a congenital biliary dilatation. No specific treatment was administered for biliary dilatation during this period. A computed tomography scan conducted during the hospitalization revealed a large cystic mass in the right upper quadrant and pelvis, measuring approximately 9.2 cm × 7.4 cm × 11.3 cm. Based on the scan, it was classified as a type I biliary dilatation. CONCLUSION: The analysis reveals that prenatal imaging techniques, such as ultrasound and magnetic resonance imaging, play a crucial role in the early diagnosis, fetal prognosis, and treatment plan for giant CBD. Laparoscopic surgery for giant CBD presents certain challenges, including difficulties in separating the cyst wall, anastomosis, and hemostasis, as well as severe biliary system infection and ulceration. Consequently, there is a high likelihood of converting to laparotomy. The choice between surgical methods like hepaticojejunostomy (HJ) or hepaticoduodenostomy has not been standardized yet. However, we have achieved favorable outcomes using HJ. Preoperative management of inflammation, biliary drainage, liver function protection, and supportive treatment are particularly vital in improving children's prognosis. After discharge, it is essential to conduct timely reexamination and close follow-up to identify potential complications.

8.
Appl Microbiol Biotechnol ; 108(1): 265, 2024 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-38498113

RESUMO

Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) is a type of polyhydroxyalkanoates (PHA) that exhibits numerous outstanding properties and is naturally synthesized and elaborately regulated in various microorganisms. However, the regulatory mechanism involving the specific regulator PhaR in Haloferax mediterranei, a major PHBV production model among Haloarchaea, is not well understood. In our previous study, we showed that deletion of the phosphoenolpyruvate (PEP) synthetase-like (pps-like) gene activates the cryptic phaC genes in H. mediterranei, resulting in enhanced PHBV accumulation. In this study, we demonstrated the specific function of the PPS-like protein as a negative regulator of phaR gene expression and PHBV synthesis. Chromatin immunoprecipitation (ChIP), in situ fluorescence reporting system, and in vitro electrophoretic mobility shift assay (EMSA) showed that the PPS-like protein can bind to the promoter region of phaRP. Computational modeling revealed a high structural similarity between the rifampin phosphotransferase (RPH) protein and the PPS-like protein, which has a conserved ATP-binding domain, a His domain, and a predicted DNA-binding domain. Key residues within this unique DNA-binding domain were subsequently validated through point mutation and functional evaluations. Based on these findings, we concluded that PPS-like protein, which we now renamed as PspR, has evolved into a repressor capable of regulating the key regulator PhaR, and thereby modulating PHBV synthesis. This regulatory network (PspR-PhaR) for PHA biosynthesis is likely widespread among haloarchaea, providing a novel approach to manipulate haloarchaea as a production platform for high-yielding PHA. KEY POINTS: • The repressive mechanism of a novel inhibitor PspR in the PHBV biosynthesis was demonstrated • PspR is widespread among the PHA accumulating haloarchaea • It is the first report of functional conversion from an enzyme to a trans-acting regulator in haloarchaea.


Assuntos
Poli-Hidroxialcanoatos , Poli-Hidroxialcanoatos/metabolismo , Hidroxibutiratos , DNA , Poliésteres/metabolismo
9.
Materials (Basel) ; 17(4)2024 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-38399136

RESUMO

Seeking novel high-performance elastocaloric materials with low critical stress plays a crucial role in advancing the development of elastocaloric refrigeration technology. Here, as a first attempt, the elastocaloric effect of TiZrNbAl shape memory alloy at both room temperature and finite temperatures ranging from 245 K to 405 K, is studied systematically. Composition optimization shows that Ti-19Zr-14Nb-1Al (at.%), possessing excellent room-temperature superelasticity with a critical stress of around 100 MPa and a small stress hysteresis of around 70 MPa and outstanding fracture resistance with a compressive strain of 20% and stress of 1.7 GPa, demonstrates a substantial advantage as an elastocaloric refrigerant. At room temperature, a large adiabatic temperature change (ΔTad) of -6.7 K is detected, which is comparable to the highest value reported in the Ti-based alloys. A high elastocaloric cyclic stability, with almost no degradation of ΔTad after 4000 cycles, is observed. Furthermore, the sizeable elastocaloric effect can be steadily expanded from 255 K to 395 K with a temperature window of as large as 140 K. A maximum ΔTad of -7.9 K appears at 355 K. The present work demonstrates a promising potential of TiZrNbAl as a low critical stress and low hysteresis elastocaloric refrigerant.

10.
Microorganisms ; 12(2)2024 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-38399707

RESUMO

Cellulolytic microorganisms play a crucial role in agricultural waste disposal. Strain QXD-8T was isolated from soil in northern China. Similarity analyses of the 16S rRNA gene, as well as the 120 conserved genes in the whole-genome sequence, indicate that it represents a novel species within the genus Microbacterium. The Microbacterium sp. QXD-8T was able to grow on the CAM plate with sodium carboxymethyl cellulose as a carbon source at 15 °C, forming a transparent hydrolysis circle after Congo red staining, even though the optimal temperature for the growth and cellulose degradation of strain QXD-8T was 28 °C. In the liquid medium, it effectively degraded cellulose and produced reducing sugars. Functional annotation revealed the presence of encoding genes for the GH5, GH6, and GH10 enzyme families with endoglucanase activity, as well as the GH1, GH3, GH39, and GH116 enzyme families with ß-glucosidase activity. Additionally, two proteins in the GH6 family, one in the GH10, and two of nine proteins in the GH3 were predicted to contain a signal peptide and transmembrane region, suggesting their potential for extracellularly degrade cellulose. Based on the physiological features of the type strain QXD-8T, we propose the name Microbacterium psychrotolerans for this novel species. This study expands the diversity of psychrotolerant cellulolytic bacteria and provides a potential microbial resource for straw returning in high-latitude areas at low temperatures.

11.
Front Nutr ; 11: 1354287, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38414489

RESUMO

Objective: The objective of this study is to explore the prevalence and attributable burden of diet high in processed meat (DHIPM) in global, regional, and national level due to the burden caused by unhealthy dietary pattern worldwide. Design: Cross-sectional study. Materials and design: All the data involved in this research were obtained from Global Burden of Diseases Study 2019. DisMod-MR 2.1, a Bayesian meta-regression tool, was used to estimate the prevalence, which was measured by summary exposure value (SEV) and attributable burden of DHIPM. The Spearman rank order correlation method was performed to measure the correlation between sociodemographic index (SDI) and the prevalence as well as attributable burden. The estimated annual percentage change (EAPC) was calculated to demonstrate the temporal trends. Results: Globally, there were 304.28 thousand deaths and 8556.88 disability-adjusted life years (DALYs) caused by DHIPM in 2019 and increased by 34.63 and 68.69%, respectively. The prevalence had decreased slightly from 1990 to 2019, however increased in most regions and countries, especially in middle SDI regions, despite the implicitly high prevalence in high SDI regions. Countries with higher SDI values were facing higher prevalence and attributable burden of DHIPM while developing countries were observed with severer temporal trends. Compared with women, men had suffered from lower exposure level however graver attributable burden of DHIPM in the past three decades. Conclusion: The progress of continuous urbanization allowed increasingly severe prevalence and attributable burden of DHIPM, thus the challenge to alleviate this trend was acute. Effective measures such as education on beneficial dietary pattern and supplement on healthy food were urgently required, especially in developing regions and countries.

12.
Analyst ; 149(5): 1489-1495, 2024 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-38314794

RESUMO

A novel cyclooxygenase-2 (COX-2) targeted H2S-activated cancer-specific fluorescent probe, namely, COX2-H2S, was designed and synthesized, with naphthalimide as the fluorophore and indomethacin as the targeting group. This H2S-sensing probe was developed to differentiate tumor cells from normal cells and was tested in living cells, Caenorhabditis elegans (C. elegans), and zebrafish. The probe could successfully be used for imaging endogenous and exogenous H2S in living cells, demonstrating high sensitivity and specificity and strong anti-interference. COX2-H2S had the ability to not only discern cancer cells from normal cells but also specifically recognize 9L/lacZ cells from other glioblastoma cells (U87-MG and LN229). It could also be successfully applied for the fluorescent live imaging of H2S in both C. elegans and zebrafish.


Assuntos
Sulfeto de Hidrogênio , Neoplasias , Animais , Humanos , Caenorhabditis elegans , Ciclo-Oxigenase 2 , Corantes Fluorescentes , Sulfeto de Hidrogênio/análise , Neoplasias/diagnóstico por imagem , Imagem Óptica/métodos , Peixe-Zebra , Linhagem Celular Tumoral
13.
Vaccines (Basel) ; 12(2)2024 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-38400198

RESUMO

Zika virus (ZIKV) is an emerging flavivirus that causes congenital syndromes including microcephaly and fetal demise in pregnant women. No commercial vaccines against ZIKV are currently available. We previously generated a chimeric ZIKV (ChinZIKV) based on the Chaoyang virus (CYV) by replacing the prME protein of CYV with that of a contemporary ZIKV strain GZ01. Herein, we evaluated this vaccine candidate in a mouse model and showed that ChinZIKV was totally safe in both adult and suckling immunodeficient mice. No viral RNA was detected in the serum of mice inoculated with ChinZIKV. All of the mice inoculated with ChinZIKV survived, while mice inoculated with ZIKV succumbed to infection in 8 days. A single dose of ChinZIKV partially protected mice against lethal ZIKV challenge. In contrast, all the control PBS-immunized mice succumbed to infection after ZIKV challenge. Our results warrant further development of ChinZIKV as a vaccine candidate in clinical trials.

14.
Luminescence ; 39(2): e4697, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38388787

RESUMO

As a high reactive oxygen species (ROS) and a reactive nitrogen species (RNS), peroxynitrite anion (ONOO- ) is widely present in organisms and plays influential roles in physiological and pathological processes. It is of great significance to develop effective fluorescent probes for imaging peroxynitrite variation in living systems. Herein we present a novel fluorescent probe TQC0 for monitoring ONOO- based on the iminocoumarin platform, and this probe was synthesized by the knoevenagel condensation between a dihydropyridine-salicylaldehyde derivative and 2-benzothiazole-acetonitrile, and subsequently masked with the boronate moiety. The obtained probe TQC0 exhibited a high signal-to-noise ratio (206-fold) and a quick 'turn-on' response (about 10 min) with great selectivity and sensitivity. Furthermore, the probe TQC0 was successfully applied for imaging ONOO- in living cells with low cytotoxicity.


Assuntos
Corantes Fluorescentes , Ácido Peroxinitroso , Razão Sinal-Ruído , Espécies Reativas de Nitrogênio , Imagem Óptica
15.
ISME J ; 18(1)2024 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-38366248

RESUMO

The origin of methanogenesis can be traced to the common ancestor of non-DPANN archaea, whereas haloarchaea (or Halobacteria) are believed to have evolved from a methanogenic ancestor through multiple evolutionary events. However, due to the accelerated evolution and compositional bias of proteins adapting to hypersaline habitats, Halobacteria exhibit substantial evolutionary divergence from methanogens, and the identification of the closest methanogen (either Methanonatronarchaeia or other taxa) to Halobacteria remains a subject of debate. Here, we obtained five metagenome-assembled genomes with high completeness from soda-saline lakes on the Ordos Plateau in Inner Mongolia, China, and we proposed the name Candidatus Ordosarchaeia for this novel class. Phylogenetic analyses revealed that Ca. Ordosarchaeia is firmly positioned near the median position between the Methanonatronarchaeia and Halobacteria-Hikarchaeia lineages. Functional predictions supported the transitional status of Ca. Ordosarchaeia with the metabolic potential of nonmethanogenic and aerobic chemoheterotrophy, as did remnants of the gene sequences of methylamine/dimethylamine/trimethylamine metabolism and coenzyme M biosynthesis. Based on the similarity of the methyl-coenzyme M reductase genes mcrBGADC in Methanonatronarchaeia with the phylogenetically distant methanogens, an alternative evolutionary scenario is proposed, in which Methanonatronarchaeia, Ca. Ordosarchaeia, Ca. Hikarchaeia, and Halobacteria share a common ancestor that initially lost mcr genes. However, certain members of Methanonatronarchaeia subsequently acquired mcr genes through horizontal gene transfer from distantly related methanogens. This hypothesis is supported by amalgamated likelihood estimation, phylogenetic analysis, and gene arrangement patterns. Altogether, Ca. Ordosarchaeia genomes clarify the sisterhood of Methanonatronarchaeia with Halobacteria and provide new insights into the evolution from methanogens to haloarchaea.


Assuntos
Euryarchaeota , Metano , Filogenia , Metano/metabolismo , Euryarchaeota/metabolismo , Archaea , Metagenoma
16.
J Med Chem ; 67(5): 3606-3625, 2024 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-38375763

RESUMO

DNA polymerase theta (Polθ) has recently emerged as a new attractive synthetic lethal target involved in DNA damage repair. Inactivating Polθ alone or in combination with PARP inhibitors has demonstrated substantial therapeutic potential against tumors with homologous recombination (HR) defects such as alternation of BRCA genes. Herein, we report the design and proof of concept of a highly potent dual Polθ/PARP inhibitor 25d, which exhibited low nanomolar inhibitory activities against both Polθ and PARP1. Compared to combination treatment, 25d demonstrated superior antitumor efficacy in both MDA-MB-436 cells and xenografts by inducing more DNA damage and apoptosis. Importantly, 25d retained sensitivity in PARP inhibitor-resistant MDA-MB-436 cells with 53BP1 defect. Altogether, these findings illustrate the potential advantages of 25d, a first-in-class dual Polθ/PARP inhibitor, over monotherapy in treating HR-deficient tumors, including those with acquired PARP inhibitor resistance.


Assuntos
Antineoplásicos , Neoplasias , Humanos , Inibidores de Poli(ADP-Ribose) Polimerases/farmacologia , Inibidores de Poli(ADP-Ribose) Polimerases/uso terapêutico , Neoplasias/tratamento farmacológico , Reparo do DNA , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Recombinação Homóloga , Linhagem Celular Tumoral
17.
Mar Environ Res ; 195: 106373, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38266547

RESUMO

Methanogens are considered to be crucial components of mangrove ecosystems with ecological significance. However, understanding the assembly processes of methanogenic communities in mangrove ecosystems is relatively insufficient. In the current study, a natural mangrove in a protection zone was employed to investigate the diversity and assembly processes of methanogenic community by using amplicon high-throughput sequencing, a null model as well as a neutral community model. The results showed that methanogenic community in mangrove sediments were highly diverse, with the predominance of methylotrophic Methanolobus, and hydrogenotrophic Methanogenium, Methanospirillum. The diversity, composition, and gene abundance varied obviously across the mangrove sampling sites, whereas the measured environmental variables exhibited a negligible effect. Null model showed that the values of beta nearest-taxon index were mostly between -2 and 2, indicating that stochastic processes contributed more than deterministic processes driving the methanogenic community assembly in mangrove sediments. Neutral community model revealed a high estimated migration rate of methanogenic community, further substantiating the significance of stochastic processes. Among the keystone species identified in network analysis, methanogens affiliated to hydrogenotrophic Methanospirillum may have a crucial role in maintaining the structure and function of methanogenic community. Notably, these keystone species were almost unaffected by measured environmental factors, indicating that the methanogenic community in mangrove sediments is more likely to be affected by stochastic processes. This study deepens the understanding of the diversity and assembly of methanogenic community in mangrove sediments, and provides clues to maintain mangrove ecosystem functioning.


Assuntos
Ecossistema , Processos Estocásticos
19.
Chem Commun (Camb) ; 60(12): 1607-1610, 2024 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-38230513

RESUMO

Extensive research has focused on genetic code reprogramming using flexizymes (Fxs), ribozymes enabling diverse tRNA acylation. Here we describe a nucleoside-modification strategy for the preparation of flexizyme variants derived from 2'-OMe, 2'-F, and 2'-MOE modifications with unique and versatile activities, enabling the charging of tRNAs with a broad range of substrates. This innovative strategy holds promise for synthetic biology applications, offering a robust pathway to expand the genetic code for diverse substrate incorporation.


Assuntos
RNA Catalítico , Aminoacilação de RNA de Transferência , Nucleosídeos/metabolismo , RNA de Transferência/metabolismo , Código Genético , RNA Catalítico/metabolismo
20.
Eur Radiol ; 34(1): 402-410, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37552255

RESUMO

OBJECTIVES: To evaluate the prognostic value of radiomics features based on late gadolinium enhancement (LGE) cardiac magnetic resonance (CMR) images in patients with cardiac amyloidosis (CA). METHODS: This retrospective study included 120 CA patients undergoing CMR at three institutions. Radiomics features were extracted from global and three different segments (base, mid-ventricular, and apex) of left ventricular (LV) on short-axis LGE images. Primary endpoint was all-cause mortality. The predictive performance of the radiomics features and semi-quantitative and quantitative LGE parameters were compared by ROC. The AUC was used to observe whether Rad-score had an incremental value for clinical stage. The Kaplan-Meier curve was used to further stratify the risk of CA patients. RESULTS: During a median follow-up of 12.9 months, 30% (40/120) patients died. There was no significant difference in the predictive performance of the radiomics model in different LV sections in the validation set (AUCs of the global, basal, middle, and apical radiomics model were 0.75, 0.77, 0.76, and 0.77, respectively; all p > 0.05). The predictive performance of the Rad-score of the base-LV was better than that of the LGE total enhancement mass (AUC:0.77 vs. 0.54, p < 0.001) and LGE extent (AUC: 0.77 vs. 0.53, p = 0.004). Rad-score combined with Mayo stage had better predictive performance than Mayo stage alone (AUC: 0.86 vs. 0.81, p = 0.03). Rad-score (≥ 0.66) contributed to the risk stratification of all-cause mortality in CA. CONCLUSIONS: Compared to quantitative LGE parameters, radiomics can better predict all-cause mortality in CA, while the combination of radiomics and Mayo stage could provide higher predictive accuracy. CLINICAL RELEVANCE STATEMENT: Radiomics analysis provides incremental value and improved risk stratification for all-cause mortality in patients with cardiac amyloidosis. KEY POINTS: • Radiomics in LV-base was superior to LGE semi-quantitative and quantitative parameters for predicting all-cause mortality in CA. • Rad-score combined with Mayo stage had better predictive performance than Mayo stage alone or radiomics alone. • Rad-score ≥ 0.66 was associated with a significantly increased risk of all-cause mortality in CA patients.


Assuntos
Amiloidose , Gadolínio , Humanos , Gadolínio/farmacologia , Meios de Contraste/farmacologia , Estudos Retrospectivos , Amiloidose/diagnóstico por imagem , Prognóstico , Valor Preditivo dos Testes , Imagem Cinética por Ressonância Magnética/métodos , Função Ventricular Esquerda
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