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1.
J Transl Med ; 22(1): 577, 2024 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-38890669

RESUMO

BACKGROUND: Inherited variations in DNA double-strand break (DSB) repair pathway are known to influence ovarian cancer occurrence, progression and treatment response. Despite its significance, survival-associated genetic variants within the DSB pathway remain underexplored. METHODS: In the present study, we performed a two-phase analysis of 19,290 single-nucleotide polymorphisms (SNPs) in 199 genes in the DSB repair pathway from a genome-wide association study (GWAS) dataset and explored their associations with overall survival (OS) in 1039 Han Chinese epithelial ovarian carcinoma (EOC) patients. After utilizing multivariate Cox regression analysis with bayesian false-discovery probability for multiple test correction, significant genetic variations were identified and subsequently underwent functional prediction and validation. RESULTS: We discovered a significant association between poor overall survival and the functional variant GEN1 rs56070363 C > T (CT + TT vs. TT, adjusted hazard ratio (HR) = 2.50, P < 0.001). And the impact of GEN1 rs56070363 C > T on survival was attributed to its reduced binding affinity to hsa-miR-1287-5p and the resultant upregulation of GEN1 mRNA expression. Overexpression of GEN1 aggregated EOC cell proliferation, invasion and migration presumably by influencing the expression of immune inhibitory factors, thereby elevating the proportion of polymorphonuclear myeloid-derived suppressor cells (PMN-MDSCs) and then constructing an immunosuppressive tumor microenvironment. CONCLUSIONS: In conclusion, GEN1 rs56070363 variant could serve as a potential predictive biomarker and chemotherapeutic target for improving the survival of EOC patients.


Assuntos
Carcinoma Epitelial do Ovário , Resolvases de Junção Holliday , Neoplasias Ovarianas , Polimorfismo de Nucleotídeo Único , Feminino , Humanos , Pessoa de Meia-Idade , Carcinoma Epitelial do Ovário/genética , Carcinoma Epitelial do Ovário/mortalidade , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , China , População do Leste Asiático/genética , Regulação Neoplásica da Expressão Gênica , Estudo de Associação Genômica Ampla , Estimativa de Kaplan-Meier , MicroRNAs/genética , Invasividade Neoplásica , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/mortalidade , Prognóstico , Análise de Sobrevida , Resolvases de Junção Holliday/genética
2.
Mol Carcinog ; 2024 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-38812445

RESUMO

Interferon regulatory factor (IRF) family genes play a critical role in colorectal cancer (CRC) development and impact patient survival. This study evaluated the influence of functional single nucleotide polymorphisms (SNPs) in IRF genes on CRC survival, including functional predictions and experimental validations. Multivariate Cox regression analysis identified three linked SNPs as significant survival predictors, with the rs141112353 T/T genotype in the 3'UTR region of IRF6 significantly associated with decreased survival (HR = 1.60, P = 6E-04). Expression quantitative trait loci (eQTL) analysis indicated that the rs141112353 TA > T alteration reduced IRF6 expression. Dual luciferase assays showed lower activity for the T allele in the presence of hsa-miR-548ap-3p. Data from The Cancer Genome Atlas (TCGA) and other databases confirmed lower IRF6 levels in CRC tissues, correlating with worse survival and inversely with M2 macrophage infiltration. In vitro, IRF6 overexpression inhibited CRC cell proliferation and M2 macrophage polarization by downregulating MIF expression. These findings suggest that the IRF6 rs141112353 TA > T variant significantly affects CRC survival, potentially by enhancing miR-548-ap-3p binding affinity.

3.
J Pharm Anal ; 14(5): 100923, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38799232

RESUMO

Over-expression of glutathione S-transferase (GST) can promote Cisplatin resistance in hepatocellular carcinoma (HCC) treatment. Hence, inhibiting GST is an attractive strategy to improve Cisplatin sensitivity in HCC therapy. Although several synthesized GST inhibitors have been developed, the side effects and narrow spectrum for anticancer seriously limit their clinical application. Considering the abundance of natural compounds with anticancer activity, this study developed a rapid fluorescence technique to screen "green" natural GST inhibitors with high specificity. The fluorescence assay demonstrated that schisanlactone B (hereafter abbreviated as C1) isolated from Xue tong significantly down-regulated GST levels in Cisplatin-resistant HCC cells in vitro and in vivo. Importantly, C1 can selectively kill HCC cells from normal liver cells, effectively improving the therapeutic effect of Cisplatin on HCC mice by down-regulating GST expression. Considering the high GST levels in HCC patients, this compound demonstrated the high potential for sensitizing HCC therapy in clinical practice by down-regulating GST levels.

4.
Int J Mol Sci ; 25(10)2024 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-38791350

RESUMO

Plant growth is coordinated with the availability of nutrients that ensure its development. Nitrate is a major source of nitrogen (N), an essential macronutrient for plant growth. It also acts as a signaling molecule to modulate gene expression, metabolism, and a variety of physiological processes. Recently, it has become evident that the calcium signal appears to be part of the nitrate signaling pathway. New key players have been discovered and described in Arabidopsis thaliana (Arabidopsis). In addition, knowledge of the molecular mechanisms of how N signaling affects growth and development, such as the nitrate control of the flowering process, is increasing rapidly. Here, we review recent advances in the identification of new components involved in nitrate signal transduction, summarize newly identified mechanisms of nitrate signaling-modulated flowering time in Arabidopsis, and suggest emerging concepts and existing open questions that will hopefully be informative for further discoveries.


Assuntos
Arabidopsis , Flores , Regulação da Expressão Gênica de Plantas , Nitratos , Transdução de Sinais , Arabidopsis/metabolismo , Arabidopsis/genética , Arabidopsis/crescimento & desenvolvimento , Arabidopsis/fisiologia , Flores/crescimento & desenvolvimento , Flores/genética , Flores/metabolismo , Nitratos/metabolismo , Proteínas de Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética
5.
J Agric Food Chem ; 72(18): 10616-10626, 2024 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-38656193

RESUMO

Deoxynivalenol (DON) is a common food contaminant that can impair male reproductive function. This study investigated the effects and mechanisms of DON exposure on progenitor Leydig cell (PLC) development in prepubertal male rats. Rats were orally administrated DON (0-4 mg/kg) from postnatal days 21-28. DON increased PLC proliferation but inhibited PLC maturation and function, including reducing testosterone levels and downregulating biomarkers like HSD11B1 and INSL3 at ≥2 mg/kg. DON also stimulated mitochondrial fission via upregulating DRP1 and FIS1 protein levels and increased oxidative stress by reducing antioxidant capacity (including NRF2, SOD1, SOD2, and CAT) in PLCs in vivo. In vitro, DON (2-4 µM) inhibited PLC androgen biosynthesis, increased reactive oxygen species production and protein levels of DRP1, FIS1, MFF, and pAMPK, decreased mitochondrial membrane potential and MFN1 protein levels, and caused mitochondrial fragmentation. The mitochondrial fission inhibitor mdivi-1 attenuated DON-induced impairments in PLCs. DON inhibited PLC steroidogenesis, increased oxidative stress, perturbed mitochondrial homeostasis, and impaired maturation. In conclusion, DON disrupts PLC development in prepubertal rats by stimulating mitochondrial fission.


Assuntos
Células Intersticiais do Testículo , Mitocôndrias , Dinâmica Mitocondrial , Estresse Oxidativo , Ratos Sprague-Dawley , Tricotecenos , Animais , Masculino , Dinâmica Mitocondrial/efeitos dos fármacos , Ratos , Células Intersticiais do Testículo/efeitos dos fármacos , Células Intersticiais do Testículo/metabolismo , Células Intersticiais do Testículo/citologia , Tricotecenos/toxicidade , Estresse Oxidativo/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Testosterona/metabolismo , Células-Tronco/efeitos dos fármacos , Células-Tronco/metabolismo , Células-Tronco/citologia , Humanos , Dinaminas/metabolismo , Dinaminas/genética , Potencial da Membrana Mitocondrial/efeitos dos fármacos
6.
BMC Psychol ; 12(1): 125, 2024 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-38443976

RESUMO

BACKGROUND: The positive association of parental phubbing with internalising and externalising problems among adolescents has gained academic traction. To date, limited research has investigated the association of parental phubbing and adolescents' Problematic Internet Use (PIU). Furthermore, the mechanism underlying this association is largely unknown. These gaps limit our understanding of family-related issues affecting PIU among adolescents. The present study explores whether there is a relation between parental phubbing and PIU and investigates the mechanisms underlying this relation among adolescents. METHODS: The participants were 495 junior high schoolers aged 11-15 years. Participants completed questionnaires on their experiences with PIU, parental phubbing, parent-child relationships, and basic psychological needs satisfaction. RESULTS: The results showed a direct and indirect positive association between parental phubbing and PIU. Furthermore, parental phubbing indirectly influenced PIU and was mediated by the parent-child relationship and basic psychological needs satisfaction, respectively. Moreover, the parent-child relationship and basic psychological needs satisfaction were sequentially mediated. CONCLUSIONS: Our study highlights the crucial role of parents in the development of adolescent PIU and provides theoretical and practical guidelines for PIU prevention and intervention.


Assuntos
Uso da Internet , Relações Pais-Filho , Humanos , Adolescente , Pais
8.
J Psychol ; 158(5): 347-367, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38411967

RESUMO

According to the humility-helping hypothesis, the question of whether humility affects altruistic behavior has received extensive attention. However, researchers have not established many links between humility and international altruism. The study explored humility as a stable personality trait and assessed whether it encouraged international altruism. It also examined the underlying mechanism between the foregoing relationship. We recruited 940 college students aged 18-23 to participate in an anonymous online survey and obtained 929 data points. The results showed that humility has a direct impact on international altruism. They largely supported the theoretical framework of the humility-helping hypothesis on the inter-group level. We also addressed the mediating effect that identification with all humanity had in the relationship between humility and international altruism. The findings showed that two forms of empathy (empathy and group empathy) have a moderating effect, indicating that different forms of empathy should be more emphasized in different social situations. Taken together, the results show that developing people's humility and helping them to identify with all humanity are key to promoting inter-group altruism, especially for those who can empathize with other people or groups.


Assuntos
Altruísmo , Empatia , Humanos , Masculino , Adulto Jovem , Feminino , Adolescente , Adulto , Personalidade/fisiologia , Modelos Psicológicos
9.
BMC Gastroenterol ; 24(1): 81, 2024 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-38395765

RESUMO

PURPOSE: To assess the diagnostic performance of Ultrasound Attenuation Analysis (USAT) in the diagnosis and grading of hepatic steatosis in patients with non-alcoholic fatty liver disease (NAFLD) using Controlled Attenuation Parameters (CAP) as a reference. MATERIALS AND METHODS: From February 13, 2023, to September 26, 2023, participants underwent CAP and USAT examinations on the same day. We used manufacturer-recommended CAP thresholds to categorize the stages of hepatic steatosis: stage 1 (mild) - 240 dB/m, stage 2 (moderate) - 265 dB/m, stage 3 (severe) - 295 dB/m. Receiver Operating Characteristic curves were employed to evaluate the diagnostic accuracy of USAT and determine the thresholds for different levels of hepatic steatosis. RESULTS: Using CAP as the reference, we observed that the average USAT value increased with the severity of hepatic steatosis, and the differences in USAT values among the different hepatic steatosis groups were statistically significant (p < 0.05). There was a strong positive correlation between USAT and CAP (r = 0.674, p < 0.0001). When using CAP as the reference, the optimal cut-off values for diagnosing and predicting different levels of hepatic steatosis with USAT were as follows: the cut-off value for excluding the presence of hepatic steatosis was 0.54 dB/cm/MHz (AUC 0.96); for mild hepatic steatosis, it was 0.59 dB/cm/MHz (AUC 0.86); for moderate hepatic steatosis, it was 0.73 dB/cm/MHz (AUC 0.81); and for severe hepatic steatosis, it was 0.87 dB/cm/MHz (AUC 0.87). CONCLUSION: USAT exhibits strong diagnostic performance for hepatic steatosis and shows a high correlation with CAP values.


Assuntos
Técnicas de Imagem por Elasticidade , Hepatopatia Gordurosa não Alcoólica , Humanos , Hepatopatia Gordurosa não Alcoólica/complicações , Hepatopatia Gordurosa não Alcoólica/diagnóstico por imagem , Biópsia , Curva ROC , Fígado/diagnóstico por imagem
10.
Food Chem ; 439: 138083, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38043278

RESUMO

Driven by economic interests, surimi adulteration has become a high-frequency issue. This study aims to assess the feasibility of gas chromatography-ion mobility spectrometry (GC-IMS) in detecting surimi adulteration. In this work, three common adulterated surimi models were established by mixing with different fish species and ratios. The fingerprints enabled a clear discrimination among different tuna surimi, and other two surimi models with different mixing ratios also showed VOCs (volatile organic compounds) differences. Results of unsupervised principal component analysis (PCA) and supervised partial least-squares discrimination analysis (PLS-DA) revealed that different types of adulterated surimi models can be well separated from each other. A total of 12, 16, and 9 VOCs were selected as the potential markers in three simulated models by PLS-DA method, respectively. Therefore, GC-IMS coupled with certain chemometrics is expected to serve as an alternative analytical tool to directly and visually detect adulterated surimi.


Assuntos
Espectrometria de Mobilidade Iônica , Compostos Orgânicos Voláteis , Animais , Espectrometria de Mobilidade Iônica/métodos , Cromatografia Gasosa-Espectrometria de Massas/métodos , Compostos Orgânicos Voláteis/análise
11.
J Steroid Biochem Mol Biol ; 236: 106424, 2024 02.
Artigo em Inglês | MEDLINE | ID: mdl-37939739

RESUMO

Bisphenol A (BPA) is a widely used plastic material and its potential endocrine disrupting effect has restricted its use and increasing use of BPA alternatives has raised health concerns. However, the effect of bisphenol alternatives on steroidogenesis remains unclear. The objective of this study was to compare inhibitory potencies of 10 BPA alternatives in the inhibition of gonadal 3ß-hydroxysteroid dehydrogenase (3ß-HSD) in three species (human, rat and mouse). The inhibitory potency for human 3ß-HSD2, rat 3ß-HSD1, and mouse 3ß-HSD6 ranged from bisphenol FL (IC50, 3.32 µM for human, 5.19 µM for rat, and 3.26 µM for mouse) to bisphenol E, F, and thiodiphenol (ineffective at 100 µM). Most BPA alternatives were mixed inhibitors of gonadal 3ß-HSD and they dose-dependently inhibited progesterone formation in KGN cells. Molecular docking analysis showed that all BPA analogs bind to steroid and NAD+ active sites. Lipophilicity of BPA alternatives was inversely correlated with IC50 values. In conclusion, BPA alternatives mostly can inhibit gonadal 3ß-HSDs and lipophilicity determines their inhibitory strength.


Assuntos
Compostos Benzidrílicos , Hidroxiesteroide Desidrogenases , Fenóis , Testículo , Ratos , Humanos , Camundongos , Animais , Masculino , Simulação de Acoplamento Molecular , Testículo/metabolismo , Relação Estrutura-Atividade , Hidroxiesteroide Desidrogenases/metabolismo , 3-Hidroxiesteroide Desidrogenases/metabolismo , 17-Hidroxiesteroide Desidrogenases/metabolismo
12.
Hum Brain Mapp ; 45(1): e26531, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37986643

RESUMO

Magnetic resonance spectroscopy (MRS) is the primary method that can measure the levels of metabolites in the brain in vivo. To achieve its potential in clinical usage, the reliability of the measurement requires further articulation. Although there are many studies that investigate the reliability of gamma-aminobutyric acid (GABA), comparatively few studies have investigated the reliability of other brain metabolites, such as glutamate (Glu), N-acetyl-aspartate (NAA), creatine (Cr), phosphocreatine (PCr), or myo-inositol (mI), which all play a significant role in brain development and functions. In addition, previous studies which predominately used only two measurements (two data points) failed to provide the details of the time effect (e.g., time-of-day) on MRS measurement within subjects. Therefore, in this study, MRS data located in the anterior cingulate cortex (ACC) were repeatedly recorded across 1 year leading to at least 25 sessions for each subject with the aim of exploring the variability of other metabolites by using the index coefficient of variability (CV); the smaller the CV, the more reliable the measurements. We found that the metabolites of NAA, tNAA, and tCr showed the smallest CVs (between 1.43% and 4.90%), and the metabolites of Glu, Glx, mI, and tCho showed modest CVs (between 4.26% and 7.89%). Furthermore, we found that the concentration reference of the ratio to water results in smaller CVs compared to the ratio to tCr. In addition, we did not find any time-of-day effect on the MRS measurements. Collectively, the results of this study indicate that the MRS measurement is reasonably reliable in quantifying the levels of metabolites.


Assuntos
Encéfalo , Giro do Cíngulo , Humanos , Giro do Cíngulo/diagnóstico por imagem , Giro do Cíngulo/metabolismo , Reprodutibilidade dos Testes , Espectroscopia de Ressonância Magnética/métodos , Encéfalo/diagnóstico por imagem , Encéfalo/metabolismo , Ácido Glutâmico/metabolismo , Creatina/metabolismo , Inositol/metabolismo , Receptores de Antígenos de Linfócitos T/metabolismo , Ácido Aspártico/metabolismo , Espectroscopia de Prótons por Ressonância Magnética , Colina/metabolismo
13.
Toxicol Lett ; 386: 20-29, 2023 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-37683804

RESUMO

Bisphenol A (BPA) is a widely used plastic material, and halogenated BPA derivatives are formed either by synthesis or environmental processes. However, the effect of halogenated bisphenols on steroidogenesis remains unclear. The aim of this study was to compare inhibition of 6 BPA derivatives on gonadal 3ß-hydroxysteroid dehydrogenases (3ß-HSDs) in three species (human, rat, and mouse). The inhibition on human 3ß-HSD2 was tetrabromo BPA (TBBPA, IC50, 1.01 µM)>trichloro BPA (TrCBPA, 3.95 µM)>tetrachloro BPA (TCBPA, 4.14 µM)>monochloro BPA (MCBPA, 4.74 µM)>others with TrCBPA of competitive, TBBPA of noncompetitive and MCBPA/TCBPA of mixed inhibition. The inhibition on rat 3ß-HSD1 was TCBPA (1.68 µM)>TrCBPA (1.72 µM)>MCBPA (2.80 µM)>BPA>others with mixed inhibition. The inhibition on mouse 3ß-HSD6 was TrCBPA (1.59 µM) >MCBPA (3.36 µM)>TCBPA (3.72 µM)>others with mixed inhibition. Molecular docking analysis showed that TBBPA, TrCBPA, and TCBPA bind to steroid active sites, contacting with catalytic residue Tyr154 of human 3ß-HSD2. MCBPA, TrCBPA, and TCBPA bind to steroid active site of rat 3ß-HSD1. MCBPA and TrCBPA bind to active site of mouse 3ß-HSD6. Regression of lowest binding energy values with Ki values revealed a significant negative linear regression (P < 0.05). In conclusion, halogenated BPA derivatives are more potent inhibitors of three 3ß-HSDs than BPA and there is structure-dependent inhibition. SYNOPSIS: Chlorinated bisphenol derivatives after water chlorination process and other halogenated bisphenols effectively inhibit human and rat 3ß-HSD activity, thereby leading to steroid hormone deficiency.

14.
Cell Mol Life Sci ; 80(10): 307, 2023 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-37768430

RESUMO

N-acetyltransferase 10 (NAT10)-mediated N4-acetylcytidine (ac4C) modification is crucial for mRNA stability and translation efficiency, yet the underlying function in mammalian preimplantation embryos remains unclear. Here, we characterized the ac4C modification landscape in mouse early embryos and found that the majority of embryos deficient in ac4C writer-NAT10 failed to develop into normal blastocysts. Through single-cell sequencing, RNA-seq, acetylated RNA immunoprecipitation combined with PCR (acRIP-PCR), and embryonic phenotype monitoring, Nop2 was screened as a target gene of Nat10. Mechanistically, Nat10 knockdown decreases the ac4C modification on Nop2 mRNA and reduces RNA and protein abundance by affecting the mRNA stability of Nop2. Then, depletion of NOP2 may inhibit the translation of transcription factor TEAD4, resulting in defective expression of the downstream lineage-specific gene Cdx2, and ultimately preventing blastomeres from undergoing the trophectoderm (TE) fate. However, exogenous Nop2 mRNA partially reverses this abnormal development. In conclusion, our findings demonstrate that defective ac4C modification of Nop2 mRNA hinders the morula-to-blastocyst transition by influencing the first cell fate decision in mice.

15.
Brain Behav ; 13(10): e3219, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37587620

RESUMO

INTRODUCTION: Brain age, the estimation of a person's age from magnetic resonance imaging (MRI) parameters, has been used as a general indicator of health. The marker requires however further validation for application in clinical contexts. Here, we show how brain age predictions perform for the same individual at various time points and validate our findings with age-matched healthy controls. METHODS: We used densely sampled T1-weighted MRI data from four individuals (from two densely sampled datasets) to observe how brain age corresponds to age and is influenced by acquisition and quality parameters. For validation, we used two cross-sectional datasets. Brain age was predicted by a pretrained deep learning model. RESULTS: We found small within-subject correlations between age and brain age. We also found evidence for the influence of field strength on brain age which replicated in the cross-sectional validation data and inconclusive effects of scan quality. CONCLUSION: The absence of maturation effects for the age range in the presented sample, brain age model bias (including training age distribution and field strength), and model error are potential reasons for small relationships between age and brain age in densely sampled longitudinal data. Clinical applications of brain age models should consider of the possibility of apparent biases caused by variation in the data acquisition process.

16.
Front Oncol ; 13: 1161639, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37483484

RESUMO

Background: Cancers arising within the gastrointestinal tract are complex disorders involving genetic events that cause the conversion of normal tissue to premalignant lesions and malignancy. Shared genetic features are reported in epithelial-based gastrointestinal cancers which indicate common susceptibility among this group of malignancies. In addition, the contribution of rare variants may constitute parts of genetic susceptibility. Methods: A cross-cancer analysis of 38,171 shared rare genetic variants from genome-wide association assays was conducted, which included data from 3,194 cases and 1,455 controls across three cancer sites (esophageal, gastric and colorectal). The SNP-level association was performed by multivariate logistic regression analyses for single cancer, followed by association analysis for SubSETs (ASSET) to adjust the bias of overlapping controls. Gene-level analyses were conducted by SKAT-O, with multiple comparison adjustments by false discovery rate (FDR). Based on the significant genes indicated by SKATO analysis, pathways analysis was conducted using Gene Ontology (GO), the Kyoto Encyclopedia of Genes and Genomes (KEGG) and Reactome databases. Results: Meta-analysis in three gastrointestinal (GI) cancers identified 13 novel susceptibility loci that reached genome-wide significance (P ASSET< 5×10-8). SKAT-O analysis revealed EXOC6, LRP5L and MIR1263/LINC01324 to be significant genes shared by GI cancers (P adj<0.05, P FDR<0.05). Furthermore, GO pathway analysis identified significant enrichment of synaptic transmission and neuron development pathways shared by all three cancer types. Conclusion: Rare variants and the corresponding genes potentially contribute to shared susceptibility in different GI cancer types. The discovery of these novel variants and genes offers new insights for the carcinogenic mechanisms and missing heritability of GI cancers.

17.
Dalton Trans ; 52(32): 11120-11129, 2023 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-37494113

RESUMO

By using 2-(9-phenanthryl)pyridine (phpyr) and its derivatives as cyclometalated ligands, we synthesized a set of isomeric red-emitting complexes Ir(phpyr-R)2tmd (R = -H, -CF3, -F and -CH3, tmd = 2,2,6,6-tetramethylheptane-3,5-dione) with different coordinated modes, including bis-five-membered and five- + six-membered Ir-(C^N) ring chelating modes. The latter are the first examples of hetero-coordinated Ir(C^N)2(L^X)-type complexes containing both five- and six-membered Ir-(C^N) metallocycles. Their coordination geometries were distinctly determined using X-ray crystallographic analysis. Compared to typical bis-five-membered ring-chelated complexes, these novel hetero-coordinated isomers show bathochromic emission and lower quantum yields. On careful analysis of their electrochemical behavior and DFT calculations, it has been found that the regulatory effects of the solitary six-membered metallocycles in Ir(phpyr-R)2tmd could not only stabilize the LUMO but also destabilize the HOMO, leading to a narrower energy gap. More importantly, DFT calculations of the relative energies of these isomeric complexes demonstrated that bis-five-membered and five- + six-membered chelating modes are more stable compared to bis-six-membered rings, consistent with experiments. This work provides guidance for the structural design of Ir(C^N)2(L^X)-type complexes.

18.
Nano Lett ; 23(11): 4800-4806, 2023 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-37195243

RESUMO

Integrated photonic circuits (PICs) have seen an explosion in interest, through to commercialization in the past decade. Most PICs rely on sharp resonances to modulate, steer, and multiplex signals. However, the spectral characteristics of high-quality resonances are highly sensitive to small variations in fabrication and material constants, which limits their applicability. Active tuning mechanisms are commonly employed to account for such deviations, consuming energy and occupying valuable chip real estate. Readily employable, accurate, and highly scalable mechanisms to tailor the modal properties of photonic integrated circuits are urgently required. Here, we present an elegant and powerful solution to achieve this in a scalable manner during the semiconductor fabrication process using existing lithography tools: by exploiting the volume shrinkage exhibited by certain polymers to permanently modulate the waveguide's effective index. This technique enables broadband and lossless tuning with immediate applicability in wide-ranging applications in optical computing, telecommunications, and free-space optics.

19.
Mol Cell ; 83(10): 1588-1604.e5, 2023 05 18.
Artigo em Inglês | MEDLINE | ID: mdl-37080207

RESUMO

Gene expression in metazoans is controlled by promoter-proximal pausing of RNA polymerase II, which can undergo productive elongation or promoter-proximal termination. Integrator-PP2A (INTAC) plays a crucial role in determining the fate of paused polymerases, but the underlying mechanisms remain unclear. Here, we establish a rapid degradation system to dissect the functions of INTAC RNA endonuclease and phosphatase modules. We find that both catalytic modules function at most if not all active promoters and enhancers, yet differentially affect polymerase fate. The endonuclease module induces promoter-proximal termination, with its disruption leading to accumulation of elongation-incompetent polymerases and downregulation of highly expressed genes, while elongation-competent polymerases accumulate at lowly expressed genes and non-coding elements, leading to their upregulation. The phosphatase module primarily prevents the release of paused polymerases and limits transcriptional activation, especially for highly paused genes. Thus, both INTAC catalytic modules have unexpectedly general yet distinct roles in dynamic transcriptional control.


Assuntos
Monoéster Fosfórico Hidrolases , RNA Polimerase II , RNA Polimerase II/genética , RNA Polimerase II/metabolismo , Monoéster Fosfórico Hidrolases/metabolismo , Regulação da Expressão Gênica , Ativação Transcricional , Regulação para Cima , Transcrição Gênica
20.
J Steroid Biochem Mol Biol ; 230: 106279, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-36871834

RESUMO

Benzophenone (BP) ultraviolet (UV) -filters have been widely used to prevent adverse effects of UV. Whether they can disrupt gonadal steroidogenesis remains unclear. Gonadal 3ß-hydroxysteroid dehydrogenases (3ß-HSD) catalyse the conversion of pregnenolone to progesterone. This study explored the effect of 12 BPs on human, rat, and mouse 3ß-HSD isoforms, and analysed the structure-activity relationship (SAR) and underlying mechanisms. The inhibitory potency was BP-1 (IC50, 5.66 ± 0.95 µM) > BP-2 (5.84 ± 2.22 µM) > BP-6 (185.8 ± 115.2 µM) > BP3-BP12 on human KGN 3ß-HSD2, BP-2 (5.90 ± 1.02 µM) > BP-1 (7.55 ± 1.26 µM) > BP3-B12 on rat testicular 3ß-HSD1, and BP-1 (15.04 ± 5.20 µM) > BP-2 (22.64 ± 11.81 µM) > BP-6(125.1 ± 34.65 µM)> BP-7 (161.1 ± 102.4 µM) > other BPs on mouse testicular 3ß-HSD6. BP-1 is a mixed inhibitor of human, rat, and mouse 3ß-HSDs, and BP-2 is a mixed inhibitor of human and rat 3ß-HSDs and a noncompetitive inhibitor of mouse 3ß-HSD6. 4-Hydroxyl substitution in the benzene ring plays a key role in enhancing potency of inhibiting human, rat, and mouse gonadal 3ß-HSDs. BP-1 and BP-2 can penetrate human KGN cells to inhibit progesterone secretion at ≥ 10 µM. Docking analysis revealed that the 4-hydroxyl group of BP-1 and BP-2 forms hydrogen bonds with residue Ser123 of human 3ß-HSD2 and residue Asp127 of rat 3ß-HSD1. In conclusion, this study demonstrates that BP-1 and BP-2 are the most potent inhibitors of human, rat, and mouse gonadal 3ß-HSDs and that there is a significant SAR difference.


Assuntos
3-Hidroxiesteroide Desidrogenases , Progesterona , Humanos , Ratos , Camundongos , Animais , Masculino , Progesterona/farmacologia , 3-Hidroxiesteroide Desidrogenases/metabolismo , 17-Hidroxiesteroide Desidrogenases/metabolismo , Testículo/metabolismo , Gônadas/metabolismo , Relação Estrutura-Atividade
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