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1.
Cell ; 180(4): 655-665.e18, 2020 02 20.
Artigo em Inglês | MEDLINE | ID: mdl-32004463

RESUMO

Human endocannabinoid systems modulate multiple physiological processes mainly through the activation of cannabinoid receptors CB1 and CB2. Their high sequence similarity, low agonist selectivity, and lack of activation and G protein-coupling knowledge have hindered the development of therapeutic applications. Importantly, missing structural information has significantly held back the development of promising CB2-selective agonist drugs for treating inflammatory and neuropathic pain without the psychoactivity of CB1. Here, we report the cryoelectron microscopy structures of synthetic cannabinoid-bound CB2 and CB1 in complex with Gi, as well as agonist-bound CB2 crystal structure. Of important scientific and therapeutic benefit, our results reveal a diverse activation and signaling mechanism, the structural basis of CB2-selective agonists design, and the unexpected interaction of cholesterol with CB1, suggestive of its endogenous allosteric modulating role.


Assuntos
Agonistas de Receptores de Canabinoides/farmacologia , Subunidades alfa Gi-Go de Proteínas de Ligação ao GTP/química , Receptor CB1 de Canabinoide/química , Receptor CB2 de Canabinoide/química , Transdução de Sinais , Regulação Alostérica , Sítio Alostérico , Animais , Células CHO , Agonistas de Receptores de Canabinoides/química , Canabinoides/química , Canabinoides/farmacologia , Linhagem Celular Tumoral , Colesterol/química , Colesterol/farmacologia , Cricetinae , Cricetulus , Subunidades alfa Gi-Go de Proteínas de Ligação ao GTP/metabolismo , Humanos , Simulação de Dinâmica Molecular , Receptor CB1 de Canabinoide/metabolismo , Receptor CB2 de Canabinoide/metabolismo , Células Sf9 , Spodoptera
2.
Cell ; 176(3): 636-648.e13, 2019 01 24.
Artigo em Inglês | MEDLINE | ID: mdl-30682372

RESUMO

Despite intensive efforts to discover highly effective treatments to eradicate tuberculosis (TB), it remains as a major threat to global human health. For this reason, new TB drugs directed toward new targets are highly coveted. MmpLs (Mycobacterial membrane proteins Large), which play crucial roles in transporting lipids, polymers and immunomodulators and which also extrude therapeutic drugs, are among the most important therapeutic drug targets to emerge in recent times. Here, crystal structures of mycobacterial MmpL3 alone and in complex with four TB drug candidates, including SQ109 (in Phase 2b-3 clinical trials), are reported. MmpL3 consists of a periplasmic pore domain and a twelve-helix transmembrane domain. Two Asp-Tyr pairs centrally located in this domain appear to be key facilitators of proton-translocation. SQ109, AU1235, ICA38, and rimonabant bind inside the transmembrane region and disrupt these Asp-Tyr pairs. This structural data will greatly advance the development of MmpL3 inhibitors as new TB drugs.


Assuntos
Proteínas de Bactérias/metabolismo , Proteínas de Bactérias/ultraestrutura , Proteínas de Membrana Transportadoras/metabolismo , Proteínas de Membrana Transportadoras/ultraestrutura , Adamantano/análogos & derivados , Adamantano/metabolismo , Antituberculosos/química , Transporte Biológico , Sistemas de Liberação de Medicamentos , Desenho de Fármacos , Etilenodiaminas/metabolismo , Humanos , Proteínas de Membrana/metabolismo , Testes de Sensibilidade Microbiana , Mycobacterium tuberculosis/metabolismo , Mycobacterium tuberculosis/ultraestrutura , Compostos de Fenilureia/metabolismo , Rimonabanto/metabolismo , Tuberculose/microbiologia
3.
Cell ; 176(3): 459-467.e13, 2019 01 24.
Artigo em Inglês | MEDLINE | ID: mdl-30639103

RESUMO

The cannabinoid receptor CB2 is predominately expressed in the immune system, and selective modulation of CB2 without the psychoactivity of CB1 has therapeutic potential in inflammatory, fibrotic, and neurodegenerative diseases. Here, we report the crystal structure of human CB2 in complex with a rationally designed antagonist, AM10257, at 2.8 Å resolution. The CB2-AM10257 structure reveals a distinctly different binding pose compared with CB1. However, the extracellular portion of the antagonist-bound CB2 shares a high degree of conformational similarity with the agonist-bound CB1, which led to the discovery of AM10257's unexpected opposing functional profile of CB2 antagonism versus CB1 agonism. Further structural analysis using mutagenesis studies and molecular docking revealed the molecular basis of their function and selectivity for CB2 and CB1. Additional analyses of our designed antagonist and agonist pairs provide important insight into the activation mechanism of CB2. The present findings should facilitate rational drug design toward precise modulation of the endocannabinoid system.


Assuntos
Receptor CB2 de Canabinoide/metabolismo , Receptor CB2 de Canabinoide/ultraestrutura , Animais , Antagonistas de Receptores de Canabinoides/farmacologia , Canabinoides/farmacologia , Desenho de Fármacos , Endocanabinoides , Humanos , Ligantes , Simulação de Acoplamento Molecular , Ligação Proteica , Receptor CB1 de Canabinoide/antagonistas & inibidores , Receptor CB2 de Canabinoide/química , Receptores de Canabinoides/química , Receptores de Canabinoides/metabolismo , Receptores de Canabinoides/ultraestrutura , Receptores Acoplados a Proteínas G/metabolismo , Células Sf9 , Relação Estrutura-Atividade
4.
Nature ; 2024 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-38776963

RESUMO

Bitter taste receptors, particularly TAS2R14, play central roles in discerning a wide array of bitter substances, ranging from dietary components to pharmaceutical agents1,2. TAS2R14 is also widely expressed in extragustatory tissues, suggesting its extra roles in diverse physiological processes and potential therapeutic applications3. Here we present cryogenic electron microscopy structures of TAS2R14 in complex with aristolochic acid, flufenamic acid and compound 28.1, coupling with different G-protein subtypes. Uniquely, a cholesterol molecule is observed occupying what is typically an orthosteric site in class A G-protein-coupled receptors. The three potent agonists bind, individually, to the intracellular pockets, suggesting a distinct activation mechanism for this receptor. Comprehensive structural analysis, combined with mutagenesis and molecular dynamic simulation studies, elucidate the broad-spectrum ligand recognition and activation of the receptor by means of intricate multiple ligand-binding sites. Our study also uncovers the specific coupling modes of TAS2R14 with gustducin and Gi1 proteins. These findings should be instrumental in advancing knowledge of bitter taste perception and its broader implications in sensory biology and drug discovery.

5.
Nature ; 585(7823): 135-140, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32610344

RESUMO

Chemokines and their receptors mediate cell migration, which influences multiple fundamental biological processes and disease conditions such as inflammation and cancer1. Although ample effort has been invested into the structural investigation of the chemokine receptors and receptor-chemokine recognition2-4, less is known about endogenous chemokine-induced receptor activation and G-protein coupling. Here we present the cryo-electron microscopy structures of interleukin-8 (IL-8, also known as CXCL8)-activated human CXC chemokine receptor 2 (CXCR2) in complex with Gi protein, along with a crystal structure of CXCR2 bound to a designed allosteric antagonist. Our results reveal a unique shallow mode of binding between CXCL8 and CXCR2, and also show the interactions between CXCR2 and Gi protein. Further structural analysis of the inactive and active states of CXCR2 reveals a distinct activation process and the competitive small-molecule antagonism of chemokine receptors. In addition, our results provide insights into how a G-protein-coupled receptor is activated by an endogenous protein molecule, which will assist in the rational development of therapeutics that target the chemokine system for better pharmacological profiles.


Assuntos
Modelos Moleculares , Receptores de Interleucina-8B/química , Receptores de Interleucina-8B/metabolismo , Transdução de Sinais , Regulação Alostérica , Sítio Alostérico , Quimiocinas/classificação , Quimiocinas/metabolismo , Subunidades alfa Gi-Go de Proteínas de Ligação ao GTP/química , Subunidades alfa Gi-Go de Proteínas de Ligação ao GTP/metabolismo , Humanos , Interleucina-8/metabolismo , Ligação Proteica , Relação Estrutura-Atividade , Especificidade por Substrato
6.
Proc Natl Acad Sci U S A ; 119(16): e2117142119, 2022 04 19.
Artigo em Inglês | MEDLINE | ID: mdl-35380892

RESUMO

The main protease (Mpro) of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a key enzyme, which extensively digests CoV replicase polyproteins essential for viral replication and transcription, making it an attractive target for antiviral drug development. However, the molecular mechanism of how Mpro of SARS-CoV-2 digests replicase polyproteins, releasing the nonstructural proteins (nsps), and its substrate specificity remain largely unknown. Here, we determine the high-resolution structures of SARS-CoV-2 Mpro in its resting state, precleavage state, and postcleavage state, constituting a full cycle of substrate cleavage. The structures show the delicate conformational changes that occur during polyprotein processing. Further, we solve the structures of the SARS-CoV-2 Mpro mutant (H41A) in complex with six native cleavage substrates from replicase polyproteins, and demonstrate that SARS-CoV-2 Mpro can recognize sequences as long as 10 residues but only have special selectivity for four subsites. These structural data provide a basis to develop potent new inhibitors against SARS-CoV-2.


Assuntos
Proteases 3C de Coronavírus , RNA-Polimerase RNA-Dependente de Coronavírus , SARS-CoV-2 , Antivirais/química , Proteases 3C de Coronavírus/química , RNA-Polimerase RNA-Dependente de Coronavírus/química , RNA-Polimerase RNA-Dependente de Coronavírus/genética , Poliproteínas/química , Conformação Proteica , Proteólise , SARS-CoV-2/enzimologia , Especificidade por Substrato/genética
7.
J Am Chem Soc ; 146(17): 11657-11668, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38641862

RESUMO

All protein-directed syntheses of metal nanoclusters (NCs) and nanoparticles (NPs) have attracted considerable attention because protein scaffolds provide a unique metal coordination environment and can adjust the shape and morphology of NCs and NPs. However, the detailed formation mechanisms of NCs or NPs directed by protein templates remain unclear. In this study, by taking advantage of the ferritin nanocage as a biotemplate to monitor the growth of Fe-O NCs as a function of time, we synthesized a series of iron NCs with different sizes and shapes and subsequently solved their corresponding three-dimensional atomic-scale structures by X-ray protein crystallography and cryo-electron microscopy. The time-dependent structure analyses revealed the growth process of these Fe-O NCs with the 4-fold channel of ferritin as nucleation sites. To our knowledge, the newly biosynthesized Fe35O23Glu12 represents the largest Fe-O NCs with a definite atomic structure. This study contributes to our understanding of the formation mechanism of iron NCs and provides an effective method for metal NC synthesis.


Assuntos
Ferritinas , Tamanho da Partícula , Ferritinas/química , Nanopartículas Metálicas/química , Ferro/química , Modelos Moleculares , Cristalografia por Raios X , Compostos Férricos/química
8.
J Transl Med ; 22(1): 446, 2024 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-38741170

RESUMO

Autism spectrum disorder (ASD) is a multifaceted neurodevelopmental disorder predominant in childhood. Despite existing treatments, the benefits are still limited. This study explored the effectiveness of mesenchymal stem cell-derived extracellular vesicles (MSC-EVs) loaded with miR-137 in enhancing autism-like behaviors and mitigating neuroinflammation. Utilizing BTBR mice as an autism model, the study demonstrated that intranasal administration of MSC-miR137-EVs ameliorates autism-like behaviors and inhibits pro-inflammatory factors via the TLR4/NF-κB pathway. In vitro evaluation of LPS-activated BV2 cells revealed that MSC-miR137-EVs target the TLR4/NF-κB pathway through miR-137 inhibits proinflammatory M1 microglia. Moreover, bioinformatics analysis identified that MSC-EVs are rich in miR-146a-5p, which targets the TRAF6/NF-κB signaling pathway. In summary, the findings suggest that the integration of MSC-EVs with miR-137 may be a promising therapeutic strategy for ASD, which is worthy of clinical adoption.


Assuntos
Comportamento Animal , Vesículas Extracelulares , Células-Tronco Mesenquimais , MicroRNAs , NF-kappa B , Transdução de Sinais , MicroRNAs/metabolismo , MicroRNAs/genética , Animais , Vesículas Extracelulares/metabolismo , NF-kappa B/metabolismo , Células-Tronco Mesenquimais/metabolismo , Transtorno Autístico/genética , Transtorno Autístico/metabolismo , Microglia/metabolismo , Masculino , Camundongos , Receptor 4 Toll-Like/metabolismo , Inflamação/patologia , Camundongos Endogâmicos C57BL , Lipopolissacarídeos
9.
Value Health ; 27(4): 405-414, 2024 04.
Artigo em Inglês | MEDLINE | ID: mdl-38309655

RESUMO

OBJECTIVES: To examine the cost-effectiveness of an enhanced postdischarge home-based care program for stroke survivors compared with usual care. METHODS: This was a trial-based economic evaluation study. One hundred and sixteen patients with ischemic stroke were recruited from neurology units in a Chinese hospital and randomized into intervention (n = 58) or usual care groups (n = 58). The intervention commenced with predischarge planning and transitioned to home follow-up postdischarge. Trained nurse case managers supported by an interdisciplinary team provided comprehensive assessment, individualized goal setting, and skill training to support home-based rehabilitation for intervention group participants. Standard care was provided to usual care group participants. Total cost and quality-adjusted life-years gained at 3-month (T1), 6-month (T2), and 12-month (T3) follow-ups were calculated. The incremental cost-effectiveness ratios between the groups were obtained. RESULTS: The intervention group showed a significant increase in utility compared with the usual care group at T1 (P = .003), T2 (P = .007), and T3 (P < .001). The average total QALY gain from baseline for the intervention group was higher than for the usual care group at all time points. The likelihood of being cost-effective ranged from 61.9% to 67.2% from the provider perspective, and from 59.7% to 66.8% from the societal perspective. CONCLUSIONS: The results showed that the intervention program was cost-effective with significantly higher quality-adjusted life-years for stroke survivors when compared with usual care. It provides economic evidence to support the development of home-based stroke rehabilitation program, especially in the low- and middle-income countries.


Assuntos
Reabilitação do Acidente Vascular Cerebral , Acidente Vascular Cerebral , Humanos , Assistência ao Convalescente , Análise Custo-Benefício , Alta do Paciente , Qualidade de Vida , Anos de Vida Ajustados por Qualidade de Vida , Acidente Vascular Cerebral/terapia , Reabilitação do Acidente Vascular Cerebral/métodos , Sobreviventes
10.
Int J Mol Sci ; 25(8)2024 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-38674061

RESUMO

Chronic inflammation is a significant contributor to the development of cancer, cardiovascular disease, diabetes, obesity, autoimmune disease, inflammatory bowel disease, and other illnesses. In the academic field, there is a constant demand for effective methods to alleviate inflammation. Astragalin (AST), a type of flavonoid glycoside that is the primary component in several widely used traditional Chinese anti-inflammatory medications in clinical practice, has garnered attention from numerous experts and scholars. This article focuses on the anti-inflammatory effects of AST and conducts research on relevant literature from 2003 to 2023. The findings indicate that AST demonstrates promising anti-inflammatory potential in various models of inflammatory diseases. Specifically, AST is believed to possess inhibitory effects on inflammation-related factors and protein levels in various in vitro cell models, such as macrophages, microglia, and epithelial cells. In vivo studies have shown that AST effectively alleviates neuroinflammation and brain damage while also exhibiting potential for treating moderate diseases such as depression and stroke; it also demonstrates significant anti-inflammatory effects on both large and small intestinal epithelial cells. Animal experiments have further demonstrated that AST exerts therapeutic effects on colitis mice. Molecular biology studies have revealed that AST regulates complex signaling networks, including NF-κB, MAPK, JAK/STAT pathways, etc. In conclusion, this review will provide insights and references for the development of AST as an anti-inflammatory agent as well as for related drug development.


Assuntos
Anti-Inflamatórios , Quempferóis , Humanos , Animais , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/uso terapêutico , Quempferóis/farmacologia , Quempferóis/uso terapêutico , Inflamação/tratamento farmacológico , Inflamação/metabolismo , Inflamação/patologia , Transdução de Sinais/efeitos dos fármacos
11.
Molecules ; 29(5)2024 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-38474647

RESUMO

A chemical study of Aesculus wilsonii Rehd. (also called Suo Luo Zi) and the in vitro anti-inflammatory effects of the obtained compounds was conducted. Retrieving results through SciFinder showed that there were four unreported compounds, aeswilosides I-IV (1-4), along with fourteen known isolates (5-18). Their structures were elucidated by extensive spectroscopic methods such as UV, IR, NMR, [α]D, and MS spectra, as well as acid hydrolysis. Among the known ones, compounds 5, 6, 8-10, and 12-16 were obtained from the Aesculus genus for the first time; compounds 7, 11, 17, and 18 were first identified from this plant. The NMR data of 5 and 18 were reported first. The effects of 1-18 on the release of nitric oxide (NO) from lipopolysaccharide (LPS)-induced RAW264.7 cells were determined. The results showed that at concentrations of 10, 25, and 50 µM, the novel compounds, aeswilosides I (1) and IV (4), along with the known ones, 1-(2-methylbutyryl)phloroglucinyl-glucopyranoside (10) and pisuminic acid (15), displayed significant inhibitory effects on NO production in a concentration-dependent manner. It is worth mentioning that compound 10 showed the best NO inhibitory effect with a relative NO production of 88.1%, which was close to that of the positive drug dexamethasone. The Elisa experiment suggested that compounds 1, 4, 10, and 15 suppressed the release of TNF-α and IL-1ß as well. In conclusion, this study enriches the spectra of compounds with potential anti-inflammatory effects in A. wilsonii and provides new references for the discovery of anti-inflammatory lead compounds, but further mechanistic research is still needed.


Assuntos
Aesculus , Camundongos , Animais , Aesculus/química , Anti-Inflamatórios/farmacologia , Células RAW 264.7 , Fator de Necrose Tumoral alfa , Sementes/química , Lipopolissacarídeos/farmacologia , Óxido Nítrico/análise
12.
BMC Psychiatry ; 23(1): 174, 2023 03 16.
Artigo em Inglês | MEDLINE | ID: mdl-36927467

RESUMO

BACKGROUND: We aimed to compare differences in infant feeding patterns (breastfeeding and complementary food supplementation) between children with the autism spectrum disorder (ASD) and typically developing (TD) children through a multicentre study. The relationship between these patterns and later core symptoms and neurodevelopment in children with ASD was also investigated. METHODS: We analysed breastfeeding and complementary feeding patterns in 1389 children with ASD and 1190 TD children. The Children Neuropsychological and Behavior Scale-Revision 2016 (CNBS-R2016) was used to assess neurodevelopmental levels. The Autism Behavior Checklist (ABC), Social Responsiveness Scale (SRS), Childhood Autism Rating Scale (CARS), and ASD Warning Behavior Subscale of the CNBS-R2016 were used to assess ASD symptoms. RESULTS: Children with ASD had a shorter breastfeeding duration in infancy (8 (3-12) months vs. 10 (6-14) months, P < 0.001), later introduction of complementary foods (P < 0.001), and poorer acceptance of complementary foods (P < 0.001) than TD children. Total ABC and CARS scores were lower in the group of children with ASD who had been breastfed for 12 months or more than in the group who had been breastfed for less than 6 months. Children with ASD who were given complementary food after 6 months had lower general quotient (GQ), adaptive ability, fine motor and language scores than those who were given complementary food within 4-6 months. Children with ASD with poor acceptance of complementary foods had higher ABC and SRS scores and lower gross motor scores than those who had good acceptance. CONCLUSIONS: Children with ASD have a shorter duration of breastfeeding, a later introduction of complementary foods, and poorer acceptance of complementary foods than TD children. These feeding patterns may be related to the symptoms and growth of children with ASD. The research suggests that continued breastfeeding for longer than 12 months may be beneficial in reducing ASD symptoms and that infants who have difficulty introducing complementary foods should be followed up for neurodevelopment. TRIAL REGISTRATION: The ethics committee of the Children's Hospital of Chongqing Medical University approved the study. Approval Number: (2018) IRB (STUDY) NO. 121, and registered in the Chinese Clinical Trial Registry (Registration number: ChiCTR2000031194, registered on 23/03/2020).


Assuntos
Transtorno do Espectro Autista , Transtorno Autístico , Criança , Humanos , Lactente , Transtorno do Espectro Autista/psicologia , Transtorno Autístico/complicações , Suplementos Nutricionais , Comportamento Alimentar
13.
Cell Biochem Funct ; 41(5): 553-563, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37218093

RESUMO

Autism spectrum disorder (ASD) is a neurodevelopmental disorder, and the etiology is unknown. Metabolic dysfunction is present in patients with ASD. In the current study, untargeted metabolomics was employed to screen the differential metabolites in the liver of BTBR mouse model of autism, and MetaboAnalyst 4.0 was used for metabolic pathway analysis. Mice were killed, and liver samples were collected for untargeted metabolomics analysis and examination of histopathology. Finally, 12 differential metabolites were identified. The intensities of phenylethylamine, 4-Guanidinobutanoic acid, leukotrieneD4, and SM(d18:1/24:1(15Z)) were significantly upregulated (p < .01), and the intensities of estradiol, CMP-N-glycoloylneuraminate, retinoyl ß-glucuronide,4-phosphopantothenoylcysteine, aldophosphamide, taurochenodesoxycholic acid, taurocholic acid, and dephospho-CoA were significantly downregulated (p < .01) in the BTBR group compared with C57 control group, indicating that differences between BTBR and C57 groups were observed in metabolic patterns. Disturbed pathways of the BTBR mice involved lipid metabolism, retinol metabolism, and amino acid and energy metabolism, revealing that bile acid-mediated activation of LXRα might contribute to metabolic dysfunction of lipid and leukotriene D4 produced by the activation of 5-LOX led to hepatic inflammation. Pathological changes in the liver tissue, such as hepatocyte vacuolization, and small amounts of inflammatory and cell necrosis, further supported metabolomic results. Moreover, Spearman's rank correlation revealed that there is a strong relationship between metabolites across liver and cortex, suggesting liver may exert action by connecting peripheral and neural systems. These findings were likely to be of pathological importance or a cause/consequence of autism, and may provide insight into key metabolic dysfunction to target potential therapeutic strategies relating to ASD.


Assuntos
Transtorno do Espectro Autista , Transtorno Autístico , Camundongos , Animais , Transtorno Autístico/metabolismo , Transtorno Autístico/patologia , Transtorno do Espectro Autista/metabolismo , Camundongos Endogâmicos , Fígado/metabolismo , Metabolômica , Modelos Animais de Doenças , Camundongos Endogâmicos C57BL
14.
Nucleic Acids Res ; 49(11): 6511-6528, 2021 06 21.
Artigo em Inglês | MEDLINE | ID: mdl-34048589

RESUMO

The zinc uptake regulator (Zur) is a member of the Fur (ferric uptake regulator) family transcriptional regulators that plays important roles in zinc homeostasis and virulence of bacteria. Upon zinc perception, Zur binds to the promoters of zinc responsive genes and controls their transcription. However, the mechanism underlying zinc-mediated Zur activation remains unclear. Here we report a 2.2-Å crystal structure of apo Zur from the phytopathogen Xanthomonas campestris pv. campestris (XcZur), which reveals the molecular mechanism that XcZur exists in a closed inactive state before regulatory zinc binding. Subsequently, we present a 1.9-Å crystal structure of holo XcZur, which, by contrast, adopts an open state that has enough capacity to bind DNA. Structural comparison and hydrogen deuterium exchange mass spectrometry (HDX-MS) analyses uncover that binding of a zinc atom in the regulatory site, formed by the hinge region, the dimerization domain and the DNA binding domain, drives a closed-to-open conformational change that is essential for XcZur activation. Moreover, key residues responsible for DNA recognition are identified by site-directed mutagenesis. This work provides important insights into zinc-induced XcZur activation and valuable discussions on the mechanism of DNA recognition.


Assuntos
Proteínas de Bactérias/química , Zinco/química , Proteínas de Bactérias/metabolismo , Cristalografia por Raios X , DNA/química , DNA/metabolismo , Modelos Moleculares , Ligação Proteica , Conformação Proteica , Alinhamento de Sequência , Transcrição Gênica , Xanthomonas campestris
15.
Proc Natl Acad Sci U S A ; 117(8): 4061-4070, 2020 02 25.
Artigo em Inglês | MEDLINE | ID: mdl-32041880

RESUMO

The fusion of inner mitochondrial membranes requires dynamin-like GTPases, Mgm1 in yeast and OPA1 in mammals, but how they mediate membrane fusion is poorly understood. Here, we determined the crystal structure of Saccharomyces cerevisiae short Mgm1 (s-Mgm1) in complex with GDP. It revealed an N-terminal GTPase (G) domain followed by two helix bundles (HB1 and HB2) and a unique C-terminal lipid-interacting stalk (LIS). Dimers can form through antiparallel HB interactions. Head-to-tail trimers are built by intermolecular interactions between the G domain and HB2-LIS. Biochemical and in vivo analyses support the idea that the assembly interfaces observed here are native and critical for Mgm1 function. We also found that s-Mgm1 interacts with negatively charged lipids via both the G domain and LIS. Based on these observations, we propose that membrane targeting via the G domain and LIS facilitates the in cis assembly of Mgm1, potentially generating a highly curved membrane tip to allow inner membrane fusion.


Assuntos
Cristalografia por Raios X , Proteínas de Ligação ao GTP/química , Proteínas de Ligação ao GTP/metabolismo , Guanosina Difosfato/química , Mitocôndrias/enzimologia , Proteínas Mitocondriais/química , Proteínas Mitocondriais/metabolismo , Proteínas de Saccharomyces cerevisiae/química , Proteínas de Saccharomyces cerevisiae/metabolismo , Proteínas de Ligação ao GTP/genética , Guanosina Difosfato/metabolismo , Metabolismo dos Lipídeos , Fusão de Membrana , Proteínas Mitocondriais/genética , Modelos Moleculares , Mutação , Conformação Proteica , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/genética
16.
J Biosoc Sci ; 55(1): 150-168, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-34839844

RESUMO

Increasing women's knowledge about maternal health is an important step towards empowering them and making them aware of their rights and health status, allowing them to seek appropriate health care. In Yemen, the ongoing conflict has hampered the delivery of health information to women in public health facilities. This study examined rural women's knowledge of, and attitude towards, maternal and child health in Yemen and identified the factors associated with good maternal health knowledge. The study was conducted between August and November 2018. A sample of 400 women aged 15-49 years who had delivered in the 6 months prior to the survey were systematically selected from selected public health facilities in Abyan and Lahj. Women were interviewed using a structured questionnaire to gather data on their demographic and economic characteristics, obstetric history and responses to health knowledge and attitude questions. Women's knowledge level was assessed as poor or good using the mean score as a cut-off. Chi-squared test and multiple logistic regression analysis were used to identify statistically significant factors associated with good maternal health knowledge. The percentage of women who had good knowledge was 44.8% (95% CI: 39.8-49.8). Women's attitude towards maternal health was negative in the areas of early ANC attendance, managing dietary regime and weight during pregnancy, facility delivery, PNC visits, cord care and mother and child health management. Women with primary education, whose husbands had received no formal education, who had their first ANC visit from the second trimester of pregnancy and who had fewer than four ANC visits were more likely to have poor health knowledge. Conversely, those with higher household income and only one child were more likely to have good maternal health knowledge. Overall, women's knowledge on maternal and child health care in rural areas of Yemen was low. Strategies are needed to increase rural women's knowledge on maternal and child health in this conflict-affected setting.


Assuntos
Serviços de Saúde Materna , Saúde Materna , Gravidez , Criança , Feminino , Humanos , Mães , Cuidado Pré-Natal , Iêmen , População Rural
17.
Int J Mol Sci ; 24(3)2023 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-36768688

RESUMO

Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by heterogeneous clinical phenotypes. Patients often experience abnormal sensory perception, which may further affect the ASD core phenotype, significantly and adversely affecting their quality of life. However, biomarkers for the diagnosis of ASD sensory perception abnormality are currently elusive. We sought to identify potential biomarkers related to ASD sensory perception abnormality to construct a prediction model that could facilitate the early identification of and screening for ASD. Differentially expressed genes in ASD were obtained from the Gene Expression Omnibus database and were screened for genes related to sensory perception abnormality. After enrichment analysis, the random forest method was used to identify disease-characteristic genes. A prediction model was constructed with an artificial neural network. Finally, the results were validated using data from the dorsal root ganglion, cerebral cortex, and striatum of the BTBR T+ Itpr3tf/J (BTBR) ASD mouse model. A total of 1869 differentially expressed genes in ASD were screened, among which 16 genes related to sensory perception abnormality were identified. According to enrichment analysis, these 16 genes were mainly related to actin, cholesterol metabolism, and tight junctions. Using random forest, 15 disease-characteristic genes were screened for model construction. The area under the curve of the training set validation result was 0.999, and for the model function validation, the result was 0.711, indicating high accuracy. The validation of BTBR mice confirmed the reliability of using these disease-characteristic genes for prediction of ASD. In conclusion, we developed a highly accurate model for predicting ASD sensory perception abnormality from 15 disease-characteristic genes. This model provides a new method for the early identification and diagnosis of ASD sensory perception abnormality.


Assuntos
Transtorno do Espectro Autista , Camundongos , Animais , Transtorno do Espectro Autista/diagnóstico , Transtorno do Espectro Autista/genética , Transtorno do Espectro Autista/metabolismo , Qualidade de Vida , Reprodutibilidade dos Testes , Camundongos Endogâmicos , Percepção , Modelos Animais de Doenças
18.
J Environ Manage ; 335: 117573, 2023 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-36840995

RESUMO

Long chain fatty acids (LCFAs) are the key intermediate of anaerobic digestion of oily food waste, not completely soluble in a water-dominant anaerobic system due to their long hydrocarbon chains with hydrophobic property. Their effective concentration affects release of high methanogenic potential and system stability. A long-term continuous anaerobic digestion of oily food waste demonstrated excess methane production of even more than feedstock in an anaerobic continuous stirred tank reactor (CSTR). Assuming feedstock COD at 100%, approximately 120% of COD as methane could be achieved. Oil floating and crystallization with Ca salt resulting from the distribution heterogeneity of LCFAs in the CSTR were found responsible for the excess methane production. Moreover, slow conversion and accumulation of saturated LCFAs with relatively lower solubility played an important role as well. Compared with unsaturated oleic (C18:1) and linoleic acids (C18:2), around twice slower methane production rate and longer lag time could be observed for those saturated LCFAs. Mixing intensity was proved to be a critical controlling factor for methanogenesis and stability possibly by affecting interaction between oil/LCFAs and anaerobes to change effective lipid loading.


Assuntos
Alimentos , Metano , Eliminação de Resíduos , Anaerobiose , Ácidos Graxos , Óleos , Eliminação de Resíduos/métodos
19.
Zhongguo Dang Dai Er Ke Za Zhi ; 25(8): 818-823, 2023 Aug 15.
Artigo em Zh | MEDLINE | ID: mdl-37668029

RESUMO

OBJECTIVES: To explore the association between maternal gestational diabetes mellitus (GDM) exposure and the development of autism spectrum disorder (ASD) in offspring. METHODS: A case-control study was conducted, recruiting 221 children with ASD and 400 healthy children as controls. Questionnaires and interviews were used to collect information on general characteristics of the children, socio-economic characteristics of the family, maternal pregnancy history, and maternal disease exposure during pregnancy. Multivariate logistic regression analysis was used to investigate the association between maternal GDM exposure and the development of ASD in offspring. The potential interaction between offspring gender and maternal GDM exposure on the development of ASD in offspring was explored. RESULTS: The proportion of maternal GDM was significantly higher in the ASD group compared to the control group (16.3% vs 9.4%, P=0.014). After adjusting for variables such as gender, gestational age, mode of delivery, parity, and maternal education level, maternal GDM exposure was a risk factor for ASD in offspring (OR=2.18, 95%CI: 1.04-4.54, P=0.038). On the basis of adjusting the above variables, after further adjusting the variables including prenatal intake of multivitamins, folic acid intake in the first three months of pregnancy, and assisted reproduction the result trend did not change, but no statistical significance was observed (OR=1.94, 95%CI: 0.74-5.11, P=0.183). There was an interaction between maternal GDM exposure and offspring gender on the development of ASD in offspring (P<0.001). Gender stratified analysis showed that only in male offspring of mothers with GDM, the risk of ASD was significantly increased (OR=3.67, 95%CI: 1.16-11.65, P=0.027). CONCLUSIONS: Maternal GDM exposure might increase the risk of ASD in offspring. There is an interaction between GDM exposure and offspring gender in the development of ASD in offspring.


Assuntos
Transtorno do Espectro Autista , Diabetes Gestacional , Criança , Feminino , Gravidez , Humanos , Masculino , Diabetes Gestacional/etiologia , Transtorno do Espectro Autista/epidemiologia , Transtorno do Espectro Autista/etiologia , Estudos de Casos e Controles , Idade Gestacional , Mães
20.
Anal Chem ; 94(30): 10659-10668, 2022 08 02.
Artigo em Inglês | MEDLINE | ID: mdl-35857817

RESUMO

The ambiguous molecular mechanism remains a leading cause for the high mortality rate of liver cancer. An evident iron overload has been unveiled in liver cancer cell proliferation, which is closely related to oxidative stress. However oxidative stress-regulated chloride intracellular channel protein 1 (CLIC1) obviously increases in liver cancer cells. Cl- is also involved in cell proliferation, and its downstream product, HClO, can induce cell carcinoma when over-generated. However, whether iron overload could mediate the variation of intracellular Cl- and HClO is still uncharted. Herein, we present a dual-responsive fluorescence reporter MQFL-NH2 for simultaneously visualizing the fluctuation of Cl-/HClO at the same spot in living cells. Electrostatic binding to Cl- effectively gave an attenuated signal with blue fluorescence, and HClO induced a sharp green fluorescence. In HL-7702 cells stimulated with iron, the blue/green dual fluorescence of MQFL-NH2 displayed that Cl- and HClO were elevated. In contrast, they were both reduced in iron-removed SMMC-7721 cells. Further results revealed that iron overload could promote the levels of Cl- and HClO by up-regulating CLIC1 and myeloperoxidase. Altogether, the work will energetically contribute to grasp the molecular mechanism in iron overload-mediated pathogenesis of liver cancer.


Assuntos
Sobrecarga de Ferro , Neoplasias Hepáticas , Canais de Cloreto , Corantes Fluorescentes/química , Células HeLa , Humanos , Ácido Hipocloroso/metabolismo , Ferro/metabolismo
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