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1.
Cell ; 187(5): 1127-1144.e21, 2024 Feb 29.
Artigo em Inglês | MEDLINE | ID: mdl-38428393

RESUMO

Chloroplasts are green plastids in the cytoplasm of eukaryotic algae and plants responsible for photosynthesis. The plastid-encoded RNA polymerase (PEP) plays an essential role during chloroplast biogenesis from proplastids and functions as the predominant RNA polymerase in mature chloroplasts. The PEP-centered transcription apparatus comprises a bacterial-origin PEP core and more than a dozen eukaryotic-origin PEP-associated proteins (PAPs) encoded in the nucleus. Here, we determined the cryo-EM structures of Nicotiana tabacum (tobacco) PEP-PAP apoenzyme and PEP-PAP transcription elongation complexes at near-atomic resolutions. Our data show the PEP core adopts a typical fold as bacterial RNAP. Fifteen PAPs bind at the periphery of the PEP core, facilitate assembling the PEP-PAP supercomplex, protect the complex from oxidation damage, and likely couple gene transcription with RNA processing. Our results report the high-resolution architecture of the chloroplast transcription apparatus and provide the structural basis for the mechanistic and functional study of transcription regulation in chloroplasts.


Assuntos
RNA Polimerases Dirigidas por DNA , Plastídeos , Cloroplastos/metabolismo , Microscopia Crioeletrônica , RNA Polimerases Dirigidas por DNA/genética , Nicotiana/genética , Fotossíntese , Plastídeos/enzimologia
2.
Cell ; 162(5): 961-73, 2015 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-26317465

RESUMO

DNA-demethylating agents have shown clinical anti-tumor efficacy via an unknown mechanism of action. Using a combination of experimental and bioinformatics analyses in colorectal cancer cells, we demonstrate that low-dose 5-AZA-CdR targets colorectal cancer-initiating cells (CICs) by inducing viral mimicry. This is associated with induction of dsRNAs derived at least in part from endogenous retroviral elements, activation of the MDA5/MAVS RNA recognition pathway, and downstream activation of IRF7. Indeed, disruption of virus recognition pathways, by individually knocking down MDA5, MAVS, or IRF7, inhibits the ability of 5-AZA-CdR to target colorectal CICs and significantly decreases 5-AZA-CdR long-term growth effects. Moreover, transfection of dsRNA into CICs can mimic the effects of 5-AZA-CdR. Together, our results represent a major shift in understanding the anti-tumor mechanisms of DNA-demethylating agents and highlight the MDA5/MAVS/IRF7 pathway as a potentially druggable target against CICs.


Assuntos
Antimetabólitos Antineoplásicos/farmacologia , Azacitidina/análogos & derivados , Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/imunologia , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Animais , Azacitidina/farmacologia , Células Cultivadas , RNA Helicases DEAD-box/metabolismo , Metilação de DNA/efeitos dos fármacos , Decitabina , Retrovirus Endógenos/metabolismo , Humanos , Fator Regulador 7 de Interferon/metabolismo , Helicase IFIH1 Induzida por Interferon , Camundongos , RNA de Cadeia Dupla/metabolismo , Receptores do Ácido Retinoico/metabolismo , Transdução de Sinais
3.
Mol Cell ; 81(7): 1469-1483.e8, 2021 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-33609448

RESUMO

We demonstrate that DNA hypomethylating agent (HMA) treatment can directly modulate the anti-tumor response and effector function of CD8+ T cells. In vivo HMA treatment promotes CD8+ T cell tumor infiltration and suppresses tumor growth via CD8+ T cell-dependent activity. Ex vivo, HMAs enhance primary human CD8+ T cell activation markers, effector cytokine production, and anti-tumor cytolytic activity. Epigenomic and transcriptomic profiling shows that HMAs vastly regulate T cell activation-related transcriptional networks, culminating with over-activation of NFATc1 short isoforms. Mechanistically, demethylation of an intragenic CpG island immediately downstream to the 3' UTR of the short isoform was associated with antisense transcription and alternative polyadenylation of NFATc1 short isoforms. High-dimensional single-cell mass cytometry analyses reveal a selective effect of HMAs on a subset of human CD8+ T cell subpopulations, increasing both the number and abundance of a granzyme Bhigh, perforinhigh effector subpopulation. Overall, our findings support the use of HMAs as a therapeutic strategy to boost anti-tumor immune response.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Ilhas de CpG/imunologia , Metilação de DNA/efeitos dos fármacos , Decitabina/farmacologia , Granzimas/imunologia , Ativação Linfocitária/efeitos dos fármacos , Metilação de DNA/imunologia , Humanos , Fatores de Transcrição NFATC/imunologia , Perforina/imunologia
4.
Plant Cell ; 36(5): 1504-1523, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38163641

RESUMO

As an essential nutrient element, phosphorus (P) is primarily acquired and translocated as inorganic phosphate (Pi) by plant roots. Pi is often sequestered in the soil and becomes limited for plant growth. Plants have developed a sophisticated array of adaptive responses, termed P starvation responses, to cope with P deficiency by improving its external acquisition and internal utilization. Over the past 2 to 3 decades, remarkable progress has been made toward understanding how plants sense and respond to changing environmental P. This review provides an overview of the molecular mechanisms that regulate or coordinate P starvation responses, emphasizing P transport, sensing, and signaling. We present the major players and regulators responsible for Pi uptake and translocation. We then introduce how P is perceived at the root tip, how systemic P signaling is operated, and the mechanisms by which the intracellular P status is sensed and conveyed. Additionally, the recent exciting findings about the influence of P on plant-microbe interactions are highlighted. Finally, the challenges and prospects concerning the interplay between P and other nutrients and strategies to enhance P utilization efficiency are discussed. Insights obtained from this knowledge may guide future research endeavors in sustainable agriculture.


Assuntos
Fósforo , Plantas , Transdução de Sinais , Fósforo/metabolismo , Transporte Biológico , Plantas/metabolismo , Raízes de Plantas/metabolismo , Fosfatos/metabolismo , Nutrientes/metabolismo
5.
Proc Natl Acad Sci U S A ; 121(5): e2318718121, 2024 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-38252820

RESUMO

Several compounds have been used for atherosclerosis treatment, including clinical trials; however, no anti-atherosclerotic drugs based on hemodynamic force-mediated atherogenesis have been discovered. Our previous studies demonstrated that "small mothers against decapentaplegic homolog 1/5" (Smad1/5) is a convergent signaling molecule for chemical [e.g., bone morphogenetic proteins (BMPs)] and mechanical (e.g., disturbed flow) stimulations and hence may serve as a promising hemodynamic-based target for anti-atherosclerosis drug development. The goal of this study was to develop a high-throughput screening (HTS) platform to identify potential compounds that can inhibit disturbed flow- and BMP-induced Smad1/5 activation and atherosclerosis. Through HTS using a Smad1/5 downstream target inhibitor of DNA binding 1 (Id-1) as a luciferase reporter, we demonstrated that KU-55933 and Apicidin suppressed Id-1 expression in AD-293 cells. KU-55933 (10 µM), Apicidin (10 µM), and the combination of half doses of each [1/2(K + A)] inhibited disturbed flow- and BMP4-induced Smad1/5 activation in human vascular endothelial cells (ECs). KU-55933, Apicidin, and 1/2(K + A) treatments caused 50.6%, 47.4%, and 73.3% inhibitions of EC proliferation induced by disturbed flow, respectively, whereas EC inflammation was only suppressed by KU-55933 and 1/2(K + A), but not Apicidin alone. Administrations of KU-55933 and 1/2(K + A) to apolipoprotein E-deficient mice inhibited Smad1/5 activation in ECs in athero-susceptible regions, thereby suppressing endothelial proliferation and inflammation, with the attenuation of atherosclerotic lesions in these mice. A unique drug screening platform has been developed to demonstrate that KU-55933 and its combination with Apicidin are promising therapeutic compounds for atherosclerosis based on hemodynamic considerations.


Assuntos
Aterosclerose , Células Endoteliais , Morfolinas , Pironas , Humanos , Animais , Camundongos , Avaliação Pré-Clínica de Medicamentos , Ensaios de Triagem em Larga Escala , Aterosclerose/tratamento farmacológico , Hemodinâmica , Inflamação
6.
Hum Mol Genet ; 32(16): 2669-2678, 2023 08 07.
Artigo em Inglês | MEDLINE | ID: mdl-37399103

RESUMO

Sarcoidosis is a complex systemic disease. Our study aimed to (1) identify novel alleles associated with sarcoidosis susceptibility; (2) provide an in-depth evaluation of HLA alleles and sarcoidosis susceptibility and (3) integrate genetic and transcription data to identify risk loci that may more directly impact disease pathogenesis. We report a genome-wide association study of 1335 sarcoidosis cases and 1264 controls of European descent (EA) and investigate associated alleles in a study of African Americans (AA: 1487 cases and 1504 controls). The EA and AA cohort was recruited from multiple United States sites. HLA alleles were imputed and tested for association with sarcoidosis susceptibility. Expression quantitative locus and colocalization analysis were performed using a subset of subjects with transcriptome data. Forty-nine SNPs in the HLA region in HLA-DRA, -DRB9, -DRB5, -DQA1 and BRD2 genes were significantly associated with sarcoidosis susceptibility in EA, rs3129888 was also a risk variant for sarcoidosis in AA. Classical HLA alleles DRB1*0101, DQA1*0101 and DQB1*0501, which are highly correlated, were also associated with sarcoidosis. rs3135287 near HLA-DRA was associated with HLA-DRA expression in peripheral blood mononuclear cells and bronchoalveolar lavage from subjects and lung tissue and whole blood from GTEx. We identified six novel SNPs (out of the seven SNPs representing the 49 significant SNPs) and nine HLA alleles associated with sarcoidosis susceptibility in the largest EA population. We also replicated our findings in an AA population. Our study reiterates the potential role of antigen recognition and/or presentation HLA class II genes in sarcoidosis pathogenesis.


Assuntos
Estudo de Associação Genômica Ampla , Sarcoidose , Humanos , Predisposição Genética para Doença , Cadeias alfa de HLA-DR/genética , Leucócitos Mononucleares , Sarcoidose/genética , Cadeias HLA-DRB1/genética , Alelos
7.
J Cell Mol Med ; 28(11): e18472, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38842129

RESUMO

Excessive load on the temporomandibular joint (TMJ) is a significant factor in the development of TMJ osteoarthritis, contributing to cartilage degeneration. The specific mechanism through which excessive load induces TMJ osteoarthritis is not fully understood; however, mechanically-activated (MA) ion channels play a crucial role. Among these channels, Piezo1 has been identified as a mediator of chondrocyte catabolic responses and is markedly increased in osteoarthritis. Our observations indicate that, under excessive load conditions, endoplasmic reticulum stress in chondrocytes results in apoptosis of the TMJ chondrocytes. Importantly, using the Piezo1 inhibitor GsMTx4 demonstrates its potential to alleviate this condition. Furthermore, Piezo1 mediates endoplasmic reticulum stress in chondrocytes by inducing calcium ion influx. Our research substantiates the role of Piezo1 as a pivotal ion channel in mediating chondrocyte overload. It elucidates the link between excessive load, cell apoptosis, and calcium ion influx through Piezo1. The findings underscore Piezo1 as a key player in the pathogenesis of TMJ osteoarthritis, shedding light on potential therapeutic interventions for this condition.


Assuntos
Apoptose , Cálcio , Condrócitos , Estresse do Retículo Endoplasmático , Canais Iônicos , Osteoartrite , Articulação Temporomandibular , Condrócitos/metabolismo , Condrócitos/patologia , Canais Iônicos/metabolismo , Canais Iônicos/genética , Animais , Articulação Temporomandibular/metabolismo , Articulação Temporomandibular/patologia , Cálcio/metabolismo , Osteoartrite/metabolismo , Osteoartrite/patologia , Humanos , Camundongos , Transdução de Sinais , Venenos de Aranha , Peptídeos e Proteínas de Sinalização Intercelular
8.
Anal Chem ; 96(2): 847-855, 2024 01 16.
Artigo em Inglês | MEDLINE | ID: mdl-38159051

RESUMO

RNA molecules undergo various chemical modifications that play critical roles in a wide range of biological processes. N6,N6-Dimethyladenosine (m6,6A) is a conserved RNA modification and is essential for the processing of rRNA. To gain a deeper understanding of the functions of m6,6A, site-specific and accurate quantification of this modification in RNA is indispensable. In this study, we developed an AlkB-facilitated demethylation (AD-m6,6A) method for the site-specific detection and quantification of m6,6A in RNA. The N6,N6-dimethyl groups in m6,6A can cause reverse transcription to stall at the m6,6A site, resulting in truncated cDNA. However, we found that Escherichia coli AlkB demethylase can effectively demethylate m6,6A in RNA, generating full-length cDNA from AlkB-treated RNA. By quantifying the amount of full-length cDNA produced using quantitative real-time PCR, we were able to achieve site-specific detection and quantification of m6,6A in RNA. Using the AD-m6,6A method, we successfully detected and quantified m6,6A at position 1851 of 18S rRNA and position 937 of mitochondrial 12S rRNA in human cells. Additionally, we found that the level of m6,6A at position 1007 of mitochondrial 12S rRNA was significantly reduced in lung tissues from sleep-deprived mice compared with control mice. Overall, the AD-m6,6A method provides a valuable tool for easy, accurate, quantitative, and site-specific detection of m6,6A in RNA, which can aid in uncovering the functions of m6,6A in human diseases.


Assuntos
Proteínas de Escherichia coli , RNA , Humanos , Animais , Camundongos , RNA/química , Adenosina/química , DNA Complementar , Metilação , Escherichia coli/genética , Escherichia coli/metabolismo , Desmetilação , Oxigenases de Função Mista
9.
Small ; 20(7): e2307111, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37806755

RESUMO

Nanodrug delivery systems have demonstrated a great potential for tumor therapy with the development of nanotechnology. Nonetheless, traditional drug delivery systems are faced with issues such as complex synthetic procedures, low reproducibility, nonspecific distribution, impenetrability of biological barrier, systemic toxicity, etc. In recent years, phage-based nanoplatforms have attracted increasing attention in tumor treatment for their regular structure, fantastic carrying property, high transduction efficiency and biosafety. Notably, therapeutic or targeting peptides can be expressed on the surface of the phages through phage display technology, enabling the phage vectors to possess multifunctions. As a result, the drug delivery efficiency on tumor will be vastly improved, thereby enhancing the therapeutic efficacy while reducing the side effects on normal tissues. Moreover, phages can overcome the hindrance of biofilm barrier to elicit antitumor effects, which exhibit great advantages compared with traditional synthetic drug delivery systems. Herein, this review not only summarizes the structure and biology of the phages, but also presents their potential as prominent nanoplatforms against tumor in different pathways to inspire the development of effective nanomedicine.


Assuntos
Bacteriófagos , Neoplasias , Humanos , Reprodutibilidade dos Testes , Sistemas de Liberação de Medicamentos/métodos , Neoplasias/tratamento farmacológico , Peptídeos/química
10.
Artigo em Inglês | MEDLINE | ID: mdl-38777120

RESUMO

BACKGROUND: Allergic bronchopulmonary aspergillosis (ABPA) is characterized by enhanced TH2 inflammatory response. Fractional exhaled nitric oxide (FeNO) measurement has been used as a valuable tool in predicting the development and management of asthma, another typical TH2 inflammation. However, the clinical significance of FeNO in ABPA remains unclear. OBJECTIVE: To investigate the association between FeNO and the prognosis of patients with ABPA to provide a basis for the use of FeNO in evaluating the efficacy of glucocorticoids in ABPA treatment. METHODS: This study comprised 2 parts; 58 patients were enrolled in the retrospective study. Clinical indexes in patients with different prognoses were compared, and receiver operating characteristic curve analysis was used to determine the threshold value. The prospective observational study involved 61 patients who were regularly followed up at 4 to 6 weeks and 6 months since the initial treatment. Patients were grouped on the basis of baseline FeNO values; correlation analysis was performed in the clinical data. RESULTS: Different prognoses were observed between patients with high and low baseline FeNO values, with a threshold value of 57 parts per billion. The percentage of Aspergillus fumigatus-specific IgE, percentage of positive A fumigatus-specific IgG, and relapse/exacerbation rate differed significantly between the high and low FeNO groups. Patients with higher FeNO needed longer treatment duration and showed shorter interval between glucocorticoid withdrawal and the next relapse/exacerbation. CONCLUSION: Our findings indicate that the level of FeNO is associated with the prognosis of ABPA. It can serve as an independent and valuable biomarker for evaluating the effectiveness of glucocorticoid treatment.

11.
Neuroradiology ; 66(4): 543-556, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38240769

RESUMO

PURPOSE: We investigated the volumetric changes in the components of the cholinergic pathway for patients with early mild cognitive impairment (EMCI) and those with late mild cognitive impairment (LMCI). The effect of patients' apolipoprotein 4 (APOE-ε4) allele status on the structural changes were analyzed. METHODS: Structural magnetic resonance imaging data were collected. Patients' demographic information, plasma data, and validated global cognitive composite scores were included. Relevant features were extracted for constructing machine learning models to differentiate between EMCI (n = 312) and LMCI (n = 541) and predict patients' neurocognitive function. The data were analyzed primarily through one-way analysis of variance and two-way analysis of covariance. RESULTS: Considerable differences were observed in cholinergic structural changes between patients with EMCI and LMCI. Cholinergic atrophy was more prominent in the LMCI cohort than in the EMCI cohort (P < 0.05 family-wise error corrected). APOE-ε4 differentially affected cholinergic atrophy in the LMCI and EMCI cohorts. For LMCI cohort, APOE-ε4 carriers exhibited increased brain atrophy (left amygdala: P = 0.001; right amygdala: P = 0.006, and right Ch123, P = 0.032). EMCI and LCMI patients showed distinctive associations of gray matter volumes in cholinergic regions with executive (R2 = 0.063 and 0.030 for EMCI and LMCI, respectively) and language (R2 = 0.095 and 0.042 for EMCI and LMCI, respectively) function. CONCLUSIONS: Our data confirmed significant cholinergic atrophy differences between early and late stages of mild cognitive impairment. The impact of the APOE-ε4 allele on cholinergic atrophy varied between the LMCI and EMCI groups.


Assuntos
Doença de Alzheimer , Disfunção Cognitiva , Humanos , Disfunção Cognitiva/patologia , Imageamento por Ressonância Magnética/métodos , Colinérgicos , Apolipoproteínas E , Atrofia , Doença de Alzheimer/patologia
12.
J Nat Prod ; 2024 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-38990199

RESUMO

Fungal secondary metabolite (SM) biosynthetic gene clusters (BGCs) containing dimethylallyltryptophan synthases (DMATSs) produce structurally diverse prenylated indole alkaloids with wide-ranging activities that have vast potential as human therapeutics. To discover new natural products produced by DMATSs, we mined the Department of Energy Joint Genome Institute's MycoCosm database for DMATS-containing BGCs. We found a DMATS BGC in Aspergillus homomorphus CBS 101889, which also contains a nonribosomal peptide synthetase (NRPS). This BGC appeared to have a previously unreported combination of genes, which suggested the cluster might make novel SMs. We refactored this BGC with highly inducible promoters into the model fungus Aspergillus nidulans. The expression of this refactored BGC in A. nidulans resulted in the production of eight tryptophan-containing diketopiperazines, six of which are new to science. We have named them homomorphins A-F (2, 4-8). Perhaps even more intriguingly, to our knowledge, this is the first discovery of C4-prenylated tryptophan-containing diketopiperazines and their derivatives. In addition, the NRPS from this BGC is the first described that has the ability to promiscuously combine tryptophan with either of two different amino acids, in this case, l-valine or l-allo-isoleucine.

13.
Nature ; 563(7732): 579-583, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30429608

RESUMO

The use of liquid biopsies for cancer detection and management is rapidly gaining prominence1. Current methods for the detection of circulating tumour DNA involve sequencing somatic mutations using cell-free DNA, but the sensitivity of these methods may be low among patients with early-stage cancer given the limited number of recurrent mutations2-5. By contrast, large-scale epigenetic alterations-which are tissue- and cancer-type specific-are not similarly constrained6 and therefore potentially have greater ability to detect and classify cancers in patients with early-stage disease. Here we develop a sensitive, immunoprecipitation-based protocol to analyse the methylome of small quantities of circulating cell-free DNA, and demonstrate the ability to detect large-scale DNA methylation changes that are enriched for tumour-specific patterns. We also demonstrate robust performance in cancer detection and classification across an extensive collection of plasma samples from several tumour types. This work sets the stage to establish biomarkers for the minimally invasive detection, interception and classification of early-stage cancers based on plasma cell-free DNA methylation patterns.


Assuntos
Ácidos Nucleicos Livres/sangue , Ácidos Nucleicos Livres/metabolismo , Metilação de DNA , DNA de Neoplasias/sangue , DNA de Neoplasias/metabolismo , Detecção Precoce de Câncer/métodos , Neoplasias/classificação , Neoplasias/genética , Adenocarcinoma/sangue , Adenocarcinoma/genética , Animais , Biomarcadores Tumorais/genética , Linhagem Celular Tumoral , Neoplasias Colorretais/sangue , Neoplasias Colorretais/genética , Análise Mutacional de DNA , Epigênese Genética , Feminino , Xenoenxertos , Humanos , Biópsia Líquida , Masculino , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Transplante de Neoplasias , Neoplasias/sangue , Especificidade de Órgãos , Neoplasias Pancreáticas/sangue , Neoplasias Pancreáticas/genética
14.
Acta Pharmacol Sin ; 45(6): 1160-1174, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38438581

RESUMO

Nicotinic acetylcholine receptors (nAChRs) regulate pain pathways with various outcomes depending on receptor subtypes, neuron types, and locations. But it remains unknown whether α4ß2 nAChRs abundantly expressed in the substantia nigra pars reticulata (SNr) have potential to mitigate hyperalgesia in pain states. We observed that injection of nAChR antagonists into the SNr reduced pain thresholds in naïve mice, whereas injection of nAChR agonists into the SNr relieved hyperalgesia in mice, subjected to capsaicin injection into the lower hind leg, spinal nerve injury, chronic constriction injury, or chronic nicotine exposure. The analgesic effects of nAChR agonists were mimicked by optogenetic stimulation of cholinergic inputs from the pedunculopontine nucleus (PPN) to the SNr, but attenuated upon downregulation of α4 nAChRs on SNr GABAergic neurons and injection of dihydro-ß-erythroidine into the SNr. Chronic nicotine-induced hyperalgesia depended on α4 nAChRs in SNr GABAergic neurons and was associated with the reduction of ACh release in the SNr. Either activation of α4 nAChRs in the SNr or optogenetic stimulation of the PPN-SNr cholinergic projection mitigated chronic nicotine-induced hyperalgesia. Interestingly, mechanical stimulation-induced ACh release was significantly attenuated in mice subjected to either capsaicin injection into the lower hind leg or SNI. These results suggest that α4 nAChRs on GABAergic neurons mediate a cholinergic analgesic circuit in the SNr, and these receptors may be effective therapeutic targets to relieve hyperalgesia in acute and chronic pain, and chronic nicotine exposure.


Assuntos
Neurônios GABAérgicos , Hiperalgesia , Camundongos Endogâmicos C57BL , Receptores Nicotínicos , Animais , Receptores Nicotínicos/metabolismo , Neurônios GABAérgicos/metabolismo , Neurônios GABAérgicos/efeitos dos fármacos , Neurônios GABAérgicos/fisiologia , Masculino , Hiperalgesia/metabolismo , Hiperalgesia/tratamento farmacológico , Camundongos , Parte Reticular da Substância Negra/metabolismo , Parte Reticular da Substância Negra/efeitos dos fármacos , Nicotina/farmacologia , Analgésicos/farmacologia , Agonistas Nicotínicos/farmacologia , Antagonistas Nicotínicos/farmacologia , Capsaicina/farmacologia , Acetilcolina/metabolismo , Optogenética , Limiar da Dor/efeitos dos fármacos
15.
Acta Pharmacol Sin ; 2024 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-38811775

RESUMO

Proprotein convertase subtilisin/kexin type 9 (PCSK9) binds to the epidermal growth factor precursor homologous domain A (EGF-A) of low-density lipoprotein receptor (LDLR) in the liver and triggers the degradation of LDLR via the lysosomal pathway, consequently leading to an elevation in plasma LDL-C levels. Inhibiting PCSK9 prolongs the lifespan of LDLR and maintains cholesterol homeostasis in the body. Thus, PCSK9 is an innovative pharmacological target for treating hypercholesterolemia and atherosclerosis. In this study, we discovered that E28362 was a novel small-molecule PCSK9 inhibitor by conducting a virtual screening of a library containing 40,000 compounds. E28362 (5, 10, 20 µM) dose-dependently increased the protein levels of LDLR in both total protein and the membrane fraction in both HepG2 and AML12 cells, and enhanced the uptake of DiI-LDL in AML12 cells. MTT assay showed that E28362 up to 80 µM had no obvious toxicity in HepG2, AML12, and HEK293a cells. The effects of E28362 on hyperlipidemia and atherosclerosis were evaluated in three different animal models. In high-fat diet-fed golden hamsters, administration of E28362 (6.7, 20, 60 mg·kg-1·d-1, i.g.) for 4 weeks significantly reduced plasma total cholesterol (TC), triglyceride (TG), low-density lipoprotein-cholesterol (LDL-C) and PCSK9 levels, and reduced liver TC and TG contents. In Western diet-fed ApoE-/- mice (20, 60 mg·kg-1·d-1, i.g.) and human PCSK9 D374Y overexpression mice (60 mg·kg-1·d-1, i.g.), administration of E28362 for 12 weeks significantly decreased plasma LDL-C levels and the area of atherosclerotic lesions in en face aortas and aortic roots. Moreover, E28362 significantly increased the protein expression level of LDLR in the liver. We revealed that E28362 selectively bound to PCSK9 in HepG2 and AML12 cells, blocked the interaction between LDLR and PCSK9, and induced the degradation of PCSK9 through the ubiquitin-proteasome pathway, which finally resulted in increased LDLR protein levels. In conclusion, E28362 can block the interaction between PCSK9 and LDLR, induce the degradation of PCSK9, increase LDLR protein levels, and alleviate hyperlipidemia and atherosclerosis in three distinct animal models, suggesting that E28362 is a promising lead compound for the treatment of hyperlipidemia and atherosclerosis.

16.
Arch Insect Biochem Physiol ; 115(1): e22067, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38014568

RESUMO

Cricotopus is a large and diverse genus of non-biting midges composed of several subgenera. Complete mitogenome sequences are available for very few Cricotopus species. The subgenus Pseudocricotopus unites species with unusual morphological structures in adult male and pupal stages, however, molecular methods are needed to verify the placement of this subgenus within Cricotopus. We obtained mitogenomes of C. (Pseudocricotopus) cf. montanus and nine other Cricotopus species for phylogenetic analysis, coupled with two Rheocricotopus species and one Synorthocladius species as outgroups. The structure of the mitogenome was similar among these Cricotopus species, exhibiting A+T bias and retaining ancestral gene order. Mutation rate, estimated as Ka/Ks, varied among genes, and was highest for ATP8 and lowest for COI. The phylogenetic relationships among species of Cricotopus, Rheocricotopus and Synorthocladius was reconstructed using Bayesian inference and maximum likelihood estimation. The phylogenetic trees confirmed placement of subgenus Pseudocricotopus, represented by Cricotopus cf. montanus, within Cricotopus. Our study increases the library of chironomid mitogenomes and provides insight into the properties of their constituent genes.


Assuntos
Chironomidae , Genoma Mitocondrial , Animais , Chironomidae/genética , Chironomidae/anatomia & histologia , Filogenia , Teorema de Bayes , Pupa
17.
Nutr J ; 23(1): 70, 2024 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-38982486

RESUMO

BACKGROUND: Trimethylamine-N-oxide (TMAO) is linked with obesity, while limited evidence on its relationship with body fat distribution. Herein, we investigated the associations between serum TMAO and longitudinal change of fat distribution in this prospective cohort study. METHODS: Data of 1964 participants (40-75y old) from Guangzhou Nutrition and Health Study (GNHS) during 2008-2014 was analyzed. Serum TMAO concentration was quantified by HPLC-MS/MS at baseline. The body composition was assessed by dual-energy X-ray absorptiometry at each 3-y follow-up. Fat distribution parameters were fat-to-lean mass ratio (FLR) and trunk-to-leg fat ratio (TLR). Fat distribution changes were derived from the coefficient of linear regression between their parameters and follow-up duration. RESULTS: After an average of 6.2-y follow-up, analysis of covariance (ANCOVA) and linear regression displayed women with higher serum TMAO level had greater increments in trunk FLR (mean ± SD: 1.47 ± 4.39, P-trend = 0.006) and TLR (mean ± SD: 0.06 ± 0.24, P-trend = 0.011). Meanwhile, for women in the highest TMAO tertile, linear mixed-effects model (LMEM) analysis demonstrated the annual estimated increments (95% CI) were 0.03 (95% CI: 0.003 - 0.06, P = 0.032) in trunk FLR and 1.28 (95% CI: -0.17 - 2.73, P = 0.083) in TLR, respectively. In men, there were no similar significant observations. Sensitivity analysis yielded consistent results. CONCLUSION: Serum TMAO displayed a more profound correlation with increment of FLR and TLR in middle-aged and older community-dwelling women in current study. More and further studies are still warranted in the future. TRIAL REGISTRATION: NCT03179657.


Assuntos
Distribuição da Gordura Corporal , Metilaminas , Humanos , Metilaminas/sangue , Feminino , Pessoa de Meia-Idade , Masculino , Estudos Prospectivos , Idoso , Distribuição da Gordura Corporal/métodos , Adulto , Absorciometria de Fóton/métodos , Composição Corporal , Estudos de Coortes , China
18.
BMC Womens Health ; 24(1): 341, 2024 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-38877419

RESUMO

BACKGROUND: This cross-sectional study aims to explore whether there exists an interaction between selenium and menopause concerning type 2 diabetes (T2D) prevalence and its related indicators such as fasting blood glucose (FBG) and homeostasis model assessment of insulin resistance (HOMA-IR). METHODS: 150 women aged 35-60 years old were finally analyzed in this study. Multivariate linear or logistic regression modeling was conducted to explore the association of selenium and the prevalence of T2D besides its related indicators. Subgroup analyses were conducted based on menopause status to assess the potential impact on the relationship. RESULTS: In the fully adjusted model, serum selenium was positively associated with FBG (ß: 0.03, CI: 0.01-0.05) and the prevalence of T2D (OR: 1.04, CI: 1.00-1.08). After stratifying the data by menopause status, compared with the postmenopausal women group, as the serum selenium concentrations increased, the FBG concentrations were significantly higher in the premenopausal women group (p for interaction = 0.0020). CONCLUSIONS: The present study found serum selenium was positively associated with FBG and the prevalence of T2D. Furthermore, the relationship between serum selenium and FBG was different in the premenopausal and postmenopausal women. More studies are still needed in the future to verify the relationship as well as to explore the specific mechanisms.


Assuntos
Glicemia , Diabetes Mellitus Tipo 2 , Resistência à Insulina , Menopausa , Selênio , Humanos , Feminino , Selênio/sangue , Estudos Transversais , Pessoa de Meia-Idade , Glicemia/análise , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/epidemiologia , Adulto , Menopausa/sangue , Resistência à Insulina/fisiologia , Jejum/sangue , Prevalência , Pós-Menopausa/sangue , Pré-Menopausa/sangue
19.
BMC Public Health ; 24(1): 47, 2024 01 02.
Artigo em Inglês | MEDLINE | ID: mdl-38166922

RESUMO

BACKGROUND: It is uncertain how COVID-19 outbreak influences the hepatitis B epidemics. This study aims to evaluate the effects on hepatitis B owing to the COVID-19 outbreak and forecast the hepatitis B epidemiological trend in mainland China to speed up the course of the "End viral hepatitis Strategy". METHODS: We estimated the causal impacts and created a forecast through adopting monthly notifications of hepatitis B each year from 2005 to 2020 in mainland China using the Bayesian structural time series (BSTS) method. RESULTS: The hepatitis B epidemics fluctuates irregularly during the period 2005-2007(APC = 8.7, P = 0.246) and 2015-2020(APC = 1.7, P = 0.290), and there is a downturn (APC=-3.2, 95% CI -5.2 to -1.2, P = 0.006) from 2007 to 2015 in mainland China. The COVID-19 outbreak was found to have a monthly average reduction on the hepatitis B epidemics of 26% (95% CI 18-35%) within the first three months in 2020,17% (95% CI 7.7-26%) within the first six months in 2020, and 10% (95% CI19-22%) all year as a result of the COVID-19 outbreak, (probability of causal effect = 96.591%, P = 0.034) and the forecasts showed an upward trend from 2021 to 2025 (annual percentage change = 4.18, 95% CI 4.0 to 4.3, P < 0.001). CONCLUSION: The COVID-19 has a positive effect on the decline of hepatitis B cases. And the potential of BSTS model to forecast the epidemiological trend of the hepatitis B can be applied in automatic public health policymaking in mainland China.


Assuntos
COVID-19 , Hepatite B , Humanos , COVID-19/epidemiologia , Teorema de Bayes , Surtos de Doenças , Hepatite B/epidemiologia , China/epidemiologia , Previsões
20.
Eur Heart J ; 44(4): 304-318, 2023 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-36380599

RESUMO

BACKGROUND AND AIMS: Atherosclerosis preferentially develops in arterial branches and curvatures where vascular endothelium is exposed to disturbed flow. In this study, the effects of disturbed flow on the regulation of vascular endothelial phosphoproteins and their contribution to therapeutic application in atherogenesis were elucidated. METHODS: Porcine models, large-scale phosphoproteomics, transgenic mice, and clinical specimens were used to discover novel site-specific phosphorylation alterations induced by disturbed flow in endothelial cells (ECs). RESULTS: A large-scale phosphoproteomics analysis of native endothelium from disturbed (athero-susceptible) vs. pulsatile flow (athero-resistant) regions of porcine aortas led to the identification of a novel atherosclerosis-related phosphoprotein vinculin (VCL) with disturbed flow-induced phosphorylation at serine 721 (VCLS721p). The induction of VCLS721p was mediated by G-protein-coupled receptor kinase 2 (GRK2)S29p and resulted in an inactive form of VCL with a closed conformation, leading to the VE-cadherin/catenin complex disruption to enhance endothelial permeability and atherogenesis. The generation of novel apolipoprotein E-deficient (ApoE-/-) mice overexpressing S721-non-phosphorylatable VCL mutant in ECs confirmed the critical role of VCLS721p in promoting atherosclerosis. The administration of a GRK2 inhibitor to ApoE-/- mice suppressed plaque formation by inhibiting endothelial VCLS721p. Studies on clinical specimens from patients with coronary artery disease (CAD) revealed that endothelial VCLS721p is a critical clinicopathological biomarker for atherosclerosis progression and that serum VCLS721p level is a promising biomarker for CAD diagnosis. CONCLUSIONS: The findings of this study indicate that endothelial VCLS721p is a valuable hemodynamic-based target for clinical assessment and treatment of vascular disorders resulting from atherosclerosis.


Assuntos
Aterosclerose , Células Endoteliais , Vinculina , Animais , Camundongos , Aterosclerose/patologia , Células Endoteliais/patologia , Endotélio Vascular/patologia , Camundongos Knockout para ApoE , Fosforilação , Suínos , Humanos
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