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1.
Nature ; 615(7951): 292-299, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36859543

RESUMO

Emotional states influence bodily physiology, as exemplified in the top-down process by which anxiety causes faster beating of the heart1-3. However, whether an increased heart rate might itself induce anxiety or fear responses is unclear3-8. Physiological theories of emotion, proposed over a century ago, have considered that in general, there could be an important and even dominant flow of information from the body to the brain9. Here, to formally test this idea, we developed a noninvasive optogenetic pacemaker for precise, cell-type-specific control of cardiac rhythms of up to 900 beats per minute in freely moving mice, enabled by a wearable micro-LED harness and the systemic viral delivery of a potent pump-like channelrhodopsin. We found that optically evoked tachycardia potently enhanced anxiety-like behaviour, but crucially only in risky contexts, indicating that both central (brain) and peripheral (body) processes may be involved in the development of emotional states. To identify potential mechanisms, we used whole-brain activity screening and electrophysiology to find brain regions that were activated by imposed cardiac rhythms. We identified the posterior insular cortex as a potential mediator of bottom-up cardiac interoceptive processing, and found that optogenetic inhibition of this brain region attenuated the anxiety-like behaviour that was induced by optical cardiac pacing. Together, these findings reveal that cells of both the body and the brain must be considered together to understand the origins of emotional or affective states. More broadly, our results define a generalizable approach for noninvasive, temporally precise functional investigations of joint organism-wide interactions among targeted cells during behaviour.


Assuntos
Comportamento Animal , Encéfalo , Emoções , Coração , Animais , Camundongos , Ansiedade/fisiopatologia , Encéfalo/fisiologia , Mapeamento Encefálico , Emoções/fisiologia , Coração/fisiologia , Comportamento Animal/fisiologia , Eletrofisiologia , Optogenética , Córtex Insular/fisiologia , Frequência Cardíaca , Channelrhodopsins , Taquicardia/fisiopatologia , Marca-Passo Artificial
2.
Am J Hum Genet ; 111(6): 1206-1221, 2024 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-38772379

RESUMO

Utilizing trio whole-exome sequencing and a gene matching approach, we identified a cohort of 18 male individuals from 17 families with hemizygous variants in KCND1, including two de novo missense variants, three maternally inherited protein-truncating variants, and 12 maternally inherited missense variants. Affected subjects present with a neurodevelopmental disorder characterized by diverse neurological abnormalities, mostly delays in different developmental domains, but also distinct neuropsychiatric signs and epilepsy. Heterozygous carrier mothers are clinically unaffected. KCND1 encodes the α-subunit of Kv4.1 voltage-gated potassium channels. All variant-associated amino acid substitutions affect either the cytoplasmic N- or C-terminus of the channel protein except for two occurring in transmembrane segments 1 and 4. Kv4.1 channels were functionally characterized in the absence and presence of auxiliary ß subunits. Variant-specific alterations of biophysical channel properties were diverse and varied in magnitude. Genetic data analysis in combination with our functional assessment shows that Kv4.1 channel dysfunction is involved in the pathogenesis of an X-linked neurodevelopmental disorder frequently associated with a variable neuropsychiatric clinical phenotype.


Assuntos
Transtornos do Neurodesenvolvimento , Adolescente , Adulto , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Epilepsia/genética , Sequenciamento do Exoma , Doenças Genéticas Ligadas ao Cromossomo X/genética , Heterozigoto , Mutação de Sentido Incorreto/genética , Transtornos do Neurodesenvolvimento/genética , Linhagem , Fenótipo , Canais de Potássio Shal/genética
3.
Immunity ; 46(1): 38-50, 2017 01 17.
Artigo em Inglês | MEDLINE | ID: mdl-27986454

RESUMO

Lipopolysaccharide (LPS), the major component of the outer membrane of Gram-negative bacteria, binds Toll-like receptor 4 (TLR4)-MD2 complex and activates innate immune responses. LPS transfer to TLR4-MD2 is catalyzed by both LPS binding protein (LBP) and CD14. To define the sequential molecular interactions underlying this transfer, we reconstituted in vitro the entire LPS transfer process from LPS micelles to TLR4-MD2. Using electron microscopy and single-molecule approaches, we characterized the dynamic intermediate complexes for LPS transfer: LBP-LPS micelles, CD14-LBP-LPS micelle, and CD14-LPS-TLR4-MD2 complex. A single LBP molecule bound longitudinally to LPS micelles catalyzed multi-rounds of LPS transfer to CD14s that rapidly dissociated from LPB-LPS complex upon LPS transfer via electrostatic interactions. Subsequently, the single LPS molecule bound to CD14 was transferred to TLR4-MD2 in a TLR4-dependent manner. The definition of the structural determinants of the LPS transfer cascade to TLR4 may enable the development of targeted therapeutics for intervention in LPS-induced sepsis.


Assuntos
Proteínas de Fase Aguda/imunologia , Proteínas de Transporte/imunologia , Receptores de Lipopolissacarídeos/imunologia , Lipopolissacarídeos/imunologia , Antígeno 96 de Linfócito/imunologia , Glicoproteínas de Membrana/imunologia , Receptor 4 Toll-Like/imunologia , Animais , Humanos , Camundongos , Microscopia Eletrônica de Transmissão , Transdução de Sinais/imunologia
4.
Nature ; 577(7789): 260-265, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31853061

RESUMO

Chronic inflammation is accompanied by recurring cycles of tissue destruction and repair and is associated with an increased risk of cancer1-3. However, how such cycles affect the clonal composition of tissues, particularly in terms of cancer development, remains unknown. Here we show that in patients with ulcerative colitis, the inflamed intestine undergoes widespread remodelling by pervasive clones, many of which are positively selected by acquiring mutations that commonly involve the NFKBIZ, TRAF3IP2, ZC3H12A, PIGR and HNRNPF genes and are implicated in the downregulation of IL-17 and other pro-inflammatory signals. Mutational profiles vary substantially between colitis-associated cancer and non-dysplastic tissues in ulcerative colitis, which indicates that there are distinct mechanisms of positive selection in both tissues. In particular, mutations in NFKBIZ are highly prevalent in the epithelium of patients with ulcerative colitis but rarely found in both sporadic and colitis-associated cancer, indicating that NFKBIZ-mutant cells are selected against during colorectal carcinogenesis. In further support of this negative selection, we found that tumour formation was significantly attenuated in Nfkbiz-mutant mice and cell competition was compromised by disruption of NFKBIZ in human colorectal cancer cells. Our results highlight common and discrete mechanisms of clonal selection in inflammatory tissues, which reveal unexpected cancer vulnerabilities that could potentially be exploited for therapeutics in colorectal cancer.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/genética , Colite Ulcerativa/genética , Taxa de Mutação , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Animais , Linhagem Celular Tumoral , Colite Ulcerativa/metabolismo , Colite Ulcerativa/patologia , Neoplasias Colorretais/genética , Humanos , Camundongos , Transdução de Sinais
5.
Proc Natl Acad Sci U S A ; 120(49): e2300919120, 2023 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-38015850

RESUMO

Smoothened (SMO) is an oncoprotein and signal transducer in the Hedgehog signaling pathway that regulates cellular differentiation and embryogenesis. As a member of the Frizzled (Class F) family of G protein-coupled receptors (GPCRs), SMO biochemically and functionally interacts with Gi family proteins. However, key molecular features of fully activated, G protein-coupled SMO remain elusive. We present the atomistic structure of activated human SMO complexed with the heterotrimeric Gi protein and two sterol ligands, equilibrated at 310 K in a full lipid bilayer at physiological salt concentration and pH. In contrast to previous experimental structures, our equilibrated SMO complex exhibits complete breaking of the pi-cation interaction between R4516.32 and W5357.55, a hallmark of Class F receptor activation. The Gi protein couples to SMO at seven strong anchor points similar to those in Class A GPCRs: intracellular loop 1, intracellular loop 2, transmembrane helix 6, and helix 8. On the path to full activation, we find that the extracellular cysteine-rich domain (CRD) undergoes a dramatic tilt, following a trajectory suggested by positions of the CRD in active and inactive experimental SMO structures. Strikingly, a sterol ligand bound to a shallow transmembrane domain (TMD) site in the initial structure migrates to a deep TMD pocket found exclusively in activator-bound SMO complexes. Thus, our results indicate that SMO interacts with Gi prior to full activation to break the molecular lock, form anchors with Gi subunits, tilt the CRD, and facilitate migration of a sterol ligand in the TMD to an activated position.


Assuntos
Proteínas Hedgehog , Esteróis , Humanos , Esteróis/metabolismo , Ligantes , Modelos Moleculares , Proteínas Hedgehog/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Receptor Smoothened/metabolismo
6.
Proc Natl Acad Sci U S A ; 120(8): e2214507120, 2023 02 21.
Artigo em Inglês | MEDLINE | ID: mdl-36795749

RESUMO

Regulation of microtubule dynamics is required to properly control various steps of neurodevelopment. In this study, we identified granule cell antiserum-positive 14 (Gcap14) as a microtubule plus-end-tracking protein and as a regulator of microtubule dynamics during neurodevelopment. Gcap14 knockout mice exhibited impaired cortical lamination. Gcap14 deficiency resulted in defective neuronal migration. Moreover, nuclear distribution element nudE-like 1 (Ndel1), an interacting partner of Gcap14, effectively corrected the downregulation of microtubule dynamics and the defects in neuronal migration caused by Gcap14 deficiency. Finally, we found that the Gcap14-Ndel1 complex participates in the functional link between microtubule and actin filament, thereby regulating their crosstalks in the growth cones of cortical neurons. Taken together, we propose that the Gcap14-Ndel1 complex is fundamental for cytoskeletal remodeling during neurodevelopmental processes such as neuronal processes elongation and neuronal migration.


Assuntos
Actinas , Proteínas Associadas aos Microtúbulos , Neurônios , Animais , Camundongos , Actinas/metabolismo , Movimento Celular/fisiologia , Camundongos Knockout , Proteínas Associadas aos Microtúbulos/genética , Proteínas Associadas aos Microtúbulos/metabolismo , Microtúbulos/metabolismo , Neuritos/metabolismo , Neurônios/metabolismo
7.
Proc Natl Acad Sci U S A ; 120(32): e2303402120, 2023 08 08.
Artigo em Inglês | MEDLINE | ID: mdl-37523531

RESUMO

The endoplasmic reticulum (ER) and mitochondria form a unique subcellular compartment called mitochondria-associated ER membranes (MAMs). Disruption of MAMs impairs Ca2+ homeostasis, triggering pleiotropic effects in the neuronal system. Genome-wide kinase-MAM interactome screening identifies casein kinase 2 alpha 1 (CK2A1) as a regulator of composition and Ca2+ transport of MAMs. CK2A1-mediated phosphorylation of PACS2 at Ser207/208/213 facilitates MAM localization of the CK2A1-PACS2-PKD2 complex, regulating PKD2-dependent mitochondrial Ca2+ influx. We further reveal that mutations of PACS2 (E209K and E211K) associated with developmental and epileptic encephalopathy-66 (DEE66) impair MAM integrity through the disturbance of PACS2 phosphorylation at Ser207/208/213. This, in turn, causes the reduction of mitochondrial Ca2+ uptake and the dramatic increase of the cytosolic Ca2+ level, thereby, inducing neurotransmitter release at the axon boutons of glutamatergic neurons. In conclusion, our findings suggest a molecular mechanism that MAM alterations induced by pathological PACS2 mutations modulate Ca2+-dependent neurotransmitter release.


Assuntos
Retículo Endoplasmático , Mitocôndrias , Mitocôndrias/metabolismo , Retículo Endoplasmático/metabolismo , Fosforilação , Neurotransmissores/metabolismo
8.
FASEB J ; 38(10): e23689, 2024 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-38785406

RESUMO

Neuroblastoma, a prevalent extracranial solid tumor in children, arises from undifferentiated nerve cells. While tumor vasculature, often characterized by increased permeability, influences metastasis and recurrence, the direct impact of blood-borne molecules on tumor progression remains unclear. In the present study, we focused on the effect of exposure to albumin, one of the most abundant proteins in the serum, on human neuroblastoma cells. Albumin exposure elevated oxidative stress and led to mitochondria dysfunction via the activation of TGFß and PI3K pathways, accompanied by an increase in the metastatic and invasive properties of neuroblastoma cells. Proteins relevant to the induction of autophagy were upregulated in response to prolonged albumin exposure. Additionally, pre-exposure to albumin before treatment resulted in increased resistance to paclitaxel. Two valeriana-type iridoid glycosides, patrisophoroside and patrinalloside, recently isolated from Nardostachys jatamansi significantly mitigated the effect of albumin on oxidative stress, cell invasiveness, and chemoresistance. These findings illuminate the potential role of blood-borne molecules, such as albumin, in the progression and metastasis of neuroblastoma, as well as the possible therapeutic implications of valeriana-type iridoid glycosides in anti-cancer treatment.


Assuntos
Resistencia a Medicamentos Antineoplásicos , Glicosídeos Iridoides , Neuroblastoma , Paclitaxel , Humanos , Neuroblastoma/patologia , Neuroblastoma/metabolismo , Neuroblastoma/tratamento farmacológico , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Paclitaxel/farmacologia , Glicosídeos Iridoides/farmacologia , Linhagem Celular Tumoral , Invasividade Neoplásica , Estresse Oxidativo/efeitos dos fármacos , Antineoplásicos Fitogênicos/farmacologia , Valeriana/química , Albumina Sérica/metabolismo
9.
Nature ; 568(7752): 351-356, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30971818

RESUMO

Heart failure with preserved ejection fraction (HFpEF) is a common syndrome with high morbidity and mortality for which there are no evidence-based therapies. Here we report that concomitant metabolic and hypertensive stress in mice-elicited by a combination of high-fat diet and inhibition of constitutive nitric oxide synthase using Nω-nitro-L-arginine methyl ester (L-NAME)-recapitulates the numerous systemic and cardiovascular features of HFpEF in humans. Expression of one of the unfolded protein response effectors, the spliced form of X-box-binding protein 1 (XBP1s), was reduced in the myocardium of our rodent model and in humans with HFpEF. Mechanistically, the decrease in XBP1s resulted from increased activity of inducible nitric oxide synthase (iNOS) and S-nitrosylation of the endonuclease inositol-requiring protein 1α (IRE1α), culminating in defective XBP1 splicing. Pharmacological or genetic suppression of iNOS, or cardiomyocyte-restricted overexpression of XBP1s, each ameliorated the HFpEF phenotype. We report that iNOS-driven dysregulation of the IRE1α-XBP1 pathway is a crucial mechanism of cardiomyocyte dysfunction in HFpEF.


Assuntos
Insuficiência Cardíaca/metabolismo , Insuficiência Cardíaca/fisiopatologia , Estresse Nitrosativo , Volume Sistólico , Animais , Dieta Hiperlipídica/efeitos adversos , Modelos Animais de Doenças , Endorribonucleases/metabolismo , Insuficiência Cardíaca/prevenção & controle , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Miócitos Cardíacos/enzimologia , Miócitos Cardíacos/metabolismo , Miócitos Cardíacos/patologia , NG-Nitroarginina Metil Éster/farmacologia , Óxido Nítrico Sintase Tipo II/antagonistas & inibidores , Óxido Nítrico Sintase Tipo II/deficiência , Óxido Nítrico Sintase Tipo II/genética , Óxido Nítrico Sintase Tipo II/metabolismo , Fenótipo , Proteínas Serina-Treonina Quinases/metabolismo , Transdução de Sinais , Proteína 1 de Ligação a X-Box/genética , Proteína 1 de Ligação a X-Box/metabolismo
10.
Nature ; 565(7739): 312-317, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30602793

RESUMO

Clonal expansion in aged normal tissues has been implicated in the development of cancer. However, the chronology and risk dependence of the expansion are poorly understood. Here we intensively sequence 682 micro-scale oesophageal samples and show, in physiologically normal oesophageal epithelia, the progressive age-related expansion of clones that carry mutations in driver genes (predominantly NOTCH1), which is substantially accelerated by alcohol consumption and by smoking. Driver-mutated clones emerge multifocally from early childhood and increase their number and size with ageing, and ultimately replace almost the entire oesophageal epithelium in the extremely elderly. Compared with mutations in oesophageal cancer, there is a marked overrepresentation of NOTCH1 and PPM1D mutations in physiologically normal oesophageal epithelia; these mutations can be acquired before late adolescence (as early as early infancy) and significantly increase in number with heavy smoking and drinking. The remodelling of the oesophageal epithelium by driver-mutated clones is an inevitable consequence of normal ageing, which-depending on lifestyle risks-may affect cancer development.


Assuntos
Envelhecimento/genética , Envelhecimento/patologia , Epitélio , Neoplasias Esofágicas/genética , Neoplasias Esofágicas/patologia , Mutação , Lesões Pré-Cancerosas/genética , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Consumo de Bebidas Alcoólicas/genética , Biópsia , Contagem de Células , Transformação Celular Neoplásica/genética , Criança , Pré-Escolar , Células Clonais/metabolismo , Células Clonais/patologia , Variações do Número de Cópias de DNA , Epitélio/metabolismo , Epitélio/patologia , Evolução Molecular , Feminino , Interação Gene-Ambiente , Genoma Humano/genética , Humanos , Lactente , Estilo de Vida , Masculino , Pessoa de Meia-Idade , Acúmulo de Mutações , Proteína Fosfatase 2C/genética , Receptor Notch1/genética , Fatores de Risco , Análise de Sequência de DNA , Análise de Célula Única , Fumar/genética , Adulto Jovem
11.
Mol Ther ; 2024 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-38582960

RESUMO

Although memory functions of immune cells characterized by increased resistance to subsequent infections after initial pathogen exposure are well-established, it remains unclear whether non-immune cells, especially tissue-resident stem cells, exhibit similar memory mechanisms. The present study revealed that detrimental effects of initial viral antigen exposure (human papillomavirus [HPV]) on diverse stem cell functions were significantly exacerbated upon subsequent secondary exposure both in vitro and in vivo. Importantly, endometrial stem cells exhibited robust memory functions following consecutive HPV antigen exposures, whereas fully differentiated cells such as fibroblasts and vesicular cells did not show corresponding changes in response to the same antigen exposures. Deficiency of angiopoietin-like 4 (ANGPTL4) achieved through small hairpin RNA knockdown in vitro and knockout (KO) mice in vivo highlighted the critical role of ANGPTL4 in governing memory functions associated with various stem cell processes. This regulation occurred through histone H3 methylation alterations and PI3K/Akt signaling pathways in response to successive HPV antigen exposures. Furthermore, memory functions associated with various stem cell functions that were evident in wild-type mice following consecutive exposures to HPV antigen were not observed in ANGPTL4 KO mice. In summary, our findings strongly support the presence of memory mechanism in non-immune cells, particularly tissue-resident stem cells.

12.
Proc Natl Acad Sci U S A ; 119(18): e2110085119, 2022 05 03.
Artigo em Inglês | MEDLINE | ID: mdl-35452328

RESUMO

G protein­coupled receptors (GPCRs) activate cellular responses ranging from odorants to neurotransmitters. Binding an agonist leads to activation of a heterotrimeric G protein (GP) that stimulates external signaling. Unfortunately, the mechanism remains unknown. We show for 15 class A GPCRs, including opioids, adrenergics, adenosines, chemokines, muscarinics, cannabinoids, serotonins, and dopamines, that interaction of an inactive GP, including Gs, Gi, Go, G11, and Gq, to the inactive GPCR, containing the intracellular ionic lock between transmembrane (TM) helices 3 and 6, evolves exothermically to form a precoupled GPCR-GP complex with an opened TM3-TM6 and the GP-α5 helix partially inserted into the GPCR but not activated. We show that binding of agonist to this precoupled GPCR-GP complex causes the Gα protein to open into its active form, with the guanosine diphosphate exposed for signaling. This GP-first paradigm provides a strategy for developing selective agonists for GPCRs since it is the pharmacophore for the precoupled GPCR-GP complex that should be used to design drugs.


Assuntos
Receptores Acoplados a Proteínas G , Transdução de Sinais , Membrana Celular/metabolismo , Proteínas de Ligação ao GTP/metabolismo , Ligantes , Ligação Proteica , Receptores Acoplados a Proteínas G/metabolismo
13.
Proc Natl Acad Sci U S A ; 119(37): e2202426119, 2022 09 13.
Artigo em Inglês | MEDLINE | ID: mdl-36067319

RESUMO

The cyanobacterial clock presents a unique opportunity to understand the biochemical basis of circadian rhythms. The core oscillator, composed of the KaiA, KaiB, and KaiC proteins, has been extensively studied, but a complete picture of its connection to the physiology of the cell is lacking. To identify previously unknown components of the clock, we used KaiB locked in its active fold as bait in an immunoprecipitation/mass spectrometry approach. We found that the most abundant interactor, other than KaiC, was a putative diguanylate cyclase protein predicted to contain multiple Per-Arnt-Sim (PAS) domains, which we propose to name KidA. Here we show that KidA directly binds to the fold-switched active form of KaiB through its N-terminal PAS domains. We found that KidA shortens the period of the circadian clock both in vivo and in vitro and alters the ability of the clock to entrain to light-dark cycles. The dose-dependent effect of KidA on the clock period could be quantitatively recapitulated by a mathematical model in which KidA stabilizes the fold-switched form of KaiB, favoring rebinding to KaiC. Put together, our results show that the period and amplitude of the clock can be modulated by regulating the access of KaiB to the fold-switched form.


Assuntos
Proteínas de Bactérias , Relógios Circadianos , Peptídeos e Proteínas de Sinalização do Ritmo Circadiano , Ritmo Circadiano , Synechococcus , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Peptídeos e Proteínas de Sinalização do Ritmo Circadiano/química , Peptídeos e Proteínas de Sinalização do Ritmo Circadiano/genética , Peptídeos e Proteínas de Sinalização do Ritmo Circadiano/metabolismo , Fosforilação , Domínios Proteicos , Synechococcus/fisiologia
14.
Proc Natl Acad Sci U S A ; 119(6)2022 02 08.
Artigo em Inglês | MEDLINE | ID: mdl-35101990

RESUMO

Emerging evidence indicates that a subset of RNA molecules annotated as noncoding contain short open reading frames that code for small functional proteins called microproteins, which have largely been overlooked due to their small size. To search for cardiac-expressed microproteins, we used a comparative genomics approach and identified mitolamban (Mtlbn) as a highly conserved 47-amino acid transmembrane protein that is abundantly expressed in the heart. Mtlbn localizes specifically to the inner mitochondrial membrane where it interacts with subunits of complex III of the electron transport chain and with mitochondrial respiratory supercomplexes. Genetic deletion of Mtlbn in mice altered complex III assembly dynamics and reduced complex III activity. Unbiased metabolomic analysis of heart tissue from Mtlbn knockout mice further revealed an altered metabolite profile consistent with deficiencies in complex III activity. Cardiac-specific Mtlbn overexpression in transgenic (TG) mice induced cardiomyopathy with histological, biochemical, and ultrastructural pathologic features that contributed to premature death. Metabolomic analysis and biochemical studies indicated that hearts from Mtlbn TG mice exhibited increased oxidative stress and mitochondrial dysfunction. These findings reveal Mtlbn as a cardiac-expressed inner mitochondrial membrane microprotein that contributes to mitochondrial electron transport chain activity through direct association with complex III and the regulation of its assembly and function.


Assuntos
Cardiomiopatias/metabolismo , Complexo III da Cadeia de Transporte de Elétrons/metabolismo , Proteínas de Membrana/metabolismo , Mitocôndrias Cardíacas/metabolismo , Proteínas Mitocondriais/metabolismo , Miocárdio/metabolismo , Animais , Cardiomiopatias/genética , Células Cultivadas , Complexo III da Cadeia de Transporte de Elétrons/genética , Proteínas de Membrana/genética , Camundongos , Camundongos Knockout , Mitocôndrias Cardíacas/genética , Proteínas Mitocondriais/genética , Especificidade de Órgãos
15.
Nano Lett ; 24(6): 1882-1890, 2024 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-38198287

RESUMO

Understanding the spatial organization of membrane proteins is crucial for unraveling key principles in cell biology. The reaction-diffusion model is commonly used to understand biochemical patterning; however, applying reaction-diffusion models to subcellular phenomena is challenging because of the difficulty in measuring protein diffusivity and interaction kinetics in the living cell. In this work, we investigated the self-organization of the plasmalemma vesicle-associated protein (PLVAP), which creates regular arrangements of fenestrated ultrastructures, using single-molecule tracking. We demonstrated that the spatial organization of the ultrastructures is associated with a decrease in the association rate by actin destabilization. We also constructed a reaction-diffusion model that accurately generates a hexagonal array with the same 130 nm spacing as the actual scale and informs the stoichiometry of the ultrastructure, which can be discerned only through electron microscopy. Through this study, we integrated single-molecule experiments and reaction-diffusion modeling to surpass the limitations of static imaging tools and proposed emergent properties of the PLVAP ultrastructure.


Assuntos
Proteínas de Transporte , Proteínas de Membrana , Proteínas de Membrana/metabolismo , Difusão , Modelos Biológicos
16.
J Cell Mol Med ; 28(8): e18356, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38668995

RESUMO

Trichospira verticillata is an annual herb that belongs to the family Asteraceae. Trichospira verticillata extract (TVE) elicits anti-plasmodial activity; however, there has been no detailed report about its anti-inflammatory effects and molecular mechanisms. In addition, herbal plants exhibit anti-inflammatory effects by suppressing the NLRP3 inflammasome. Therefore, the primary goal of this study was to examine the effects of TVE on NLRP3 inflammasome activation by measuring interleukin-1ß (IL-1ß) secretion. We treated lipopolysaccharides (LPS)-primed J774A.1 and THP-1 cells with TVE, which attenuated NLRP3 inflammasome activation. Notably, TVE did not affect nuclear factor-kappa B (NF-κB) signalling or intracellular reactive oxygen species (ROS) production and potassium efflux, suggesting that it inactivates the NLRP3 inflammasome via other mechanisms. Moreover, TVE suppressed the formation of apoptosis-associated speck-like protein (ASC) speck and oligomerization. Immunoprecipitation data revealed that TVE reduced the binding of NLRP3 to NIMA-related kinase 7 (NEK7), resulting in reduced ASC oligomerization and speck formation. Moreover, TVE alleviated neutrophilic asthma (NA) symptoms in mice. This study demonstrates that TVE modulates the binding of NLPR3 to NEK7, thereby reporting novel insights into the mechanism by which TVE inhibits NLRP3 inflammasome. These findings suggest TVE as a potential therapeutic of NLRP3 inflammasome-mediated diseases, particularly NA.


Assuntos
Anti-Inflamatórios , Asma , Inflamassomos , Proteína 3 que Contém Domínio de Pirina da Família NLR , Neutrófilos , Espécies Reativas de Oxigênio , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Animais , Inflamassomos/metabolismo , Asma/metabolismo , Asma/tratamento farmacológico , Asma/imunologia , Asma/patologia , Camundongos , Anti-Inflamatórios/farmacologia , Humanos , Neutrófilos/metabolismo , Neutrófilos/efeitos dos fármacos , Neutrófilos/imunologia , Espécies Reativas de Oxigênio/metabolismo , Lipopolissacarídeos , Quinases Relacionadas a NIMA/metabolismo , Interleucina-1beta/metabolismo , NF-kappa B/metabolismo , Transdução de Sinais/efeitos dos fármacos , Modelos Animais de Doenças , Extratos Vegetais/farmacologia , Células THP-1
17.
Circulation ; 148(16): 1195-1206, 2023 10 17.
Artigo em Inglês | MEDLINE | ID: mdl-37634092

RESUMO

BACKGROUND: Intravascular imaging-guided percutaneous coronary intervention (PCI) with intravascular ultrasound (IVUS) or optical coherence tomography (OCT) showed superior clinical outcomes compared with angiography-guided PCI. However, the comparative effectiveness of OCT-guided and IVUS-guided PCI regarding clinical outcomes is unknown. METHODS: In this prospective, multicenter, open-label, pragmatic trial, we randomly assigned 2008 patients with significant coronary artery lesions undergoing PCI in a 1:1 ratio to undergo either an OCT-guided or IVUS-guided PCI. The primary end point was a composite of death from cardiac causes, target vessel-related myocardial infarction, or ischemia-driven target-vessel revascularization at 1 year, which was powered for noninferiority of the OCT group compared with the IVUS group. Safety outcomes were also assessed. RESULTS: At 1 year, primary end point events occurred in 25 of 1005 patients (Kaplan-Meier estimate, 2.5%) in the OCT group and in 31 of 1003 patients (Kaplan-Meier estimate, 3.1%) in the IVUS group (absolute difference, -0.6 percentage points; upper boundary of one-sided 97.5% CI, 0.97 percentage points; P<0.001 for noninferiority). The incidence of contrast-induced nephropathy was similar (14 patients [1.4%] in the OCT group versus 15 patients [1.5%] in the IVUS group; P=0.85). The incidence of major procedural complications was lower in the OCT group than in the IVUS group (22 [2.2%] versus 37 [3.7%]; P=0.047), although imaging procedure-related complications were not observed. CONCLUSIONS: In patients with significant coronary artery lesions, OCT-guided PCI was noninferior to IVUS-guided PCI with respect to the incidence of a composite of death from cardiac causes, target vessel-related myocardial infarction, or ischemia-driven target-vessel revascularization at 1 year. The selected study population and lower-than-expected event rates should be considered in interpreting the trial. REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique number: NCT03394079.


Assuntos
Doença da Artéria Coronariana , Stents Farmacológicos , Infarto do Miocárdio , Intervenção Coronária Percutânea , Humanos , Intervenção Coronária Percutânea/efeitos adversos , Intervenção Coronária Percutânea/métodos , Angiografia Coronária/métodos , Tomografia de Coerência Óptica/métodos , Estudos Prospectivos , Stents Farmacológicos/efeitos adversos , Ultrassonografia de Intervenção/efeitos adversos , Ultrassonografia de Intervenção/métodos , Resultado do Tratamento , Infarto do Miocárdio/etiologia , Doença da Artéria Coronariana/diagnóstico por imagem , Doença da Artéria Coronariana/cirurgia
18.
J Am Chem Soc ; 146(9): 6094-6103, 2024 03 06.
Artigo em Inglês | MEDLINE | ID: mdl-38407938

RESUMO

Our recent discovery of decreased reorganization energy in electrode-tethered redox-DNA systems prompts inquiries into the origin of this phenomenon and suggests its potential use to lower the activation energy of electrochemical reactions. Here, we show that the confinement of the DNA chain in a nanogap amplifies this effect to an extent to which it nearly abolishes the intrinsic activation energy of electron transfer. Employing electrochemical atomic force microscopy (AFM-SECM), we create sub-10 nm nanogaps between a planar electrode surface bearing end-anchored ferrocenylated DNA chains and an incoming microelectrode tip. The redox cycling of the DNA's ferrocenyl (Fc) moiety between the surface and the tip generates a measurable current at the scale of ∼10 molecules. Our experimental findings are rigorously interpreted through theoretical modeling and original molecular dynamics simulations (Q-Biol code). Several intriguing findings emerge from our investigation: (i) The electron transport resulting from DNA dynamics is many times faster than predicted by simple diffusion considerations. (ii) The current in the nanogap is solely governed by the electron transfer rate at the electrodes. (iii) This rate rapidly saturates as overpotentials applied to the nanogap electrodes increase, implying near-complete suppression of the reorganization energy for the oxidation/reduction of the Fc heads within confined DNA. Furthermore, evidence is presented that this may constitute a general, previously unforeseen, behavior of redox polymer chains in electrochemical nanogaps.


Assuntos
DNA , Elétrons , Transporte de Elétrons , Oxirredução , DNA/química , Eletrodos , Microeletrodos
19.
Plant Cell Physiol ; 2024 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-38957969

RESUMO

The INDUCER OF CBF EXPRESSION 1/C-REPEAT BINDING FACTOR (ICE1/CBF) pathway plays a crucial role in plant responses to cold stress, impacting growth and development. Here, we demonstrated that ATBS1-INTERACTING FACTOR 2 (AIF2), a non-DNA-binding basic helix-loop-helix transcription factor, positively regulates freezing tolerance through the ICE1/CBF-induced cold tolerance pathway in Arabidopsis. Cold stress transcriptionally upregulated AIF2 expression and induced AIF2 phosphorylation, thereby stabilizing the AIF2 protein during early stages of cold acclimation. The AIF2 loss-of-function mutant, aif2-1, exhibited heightened sensitivity to freezing before and after cold acclimation. In contrast, ectopic expression of AIF2, but not the C-terminal-deleted AIF2 variant, restored freezing tolerance. AIF2 enhanced ICE1 stability during cold acclimation and promoted the transcriptional expression of CBFs and downstream cold-responsive genes, ultimately enhancing plant tolerance to freezing stress. MITOGEN-ACTIVATED PROTEIN KINASES 3 and 6 (MPK3/6), known negative regulators of freezing tolerance, interacted with and phosphorylated AIF2, subjecting it to protein degradation. Furthermore, transient co-expression of MPK3/6 with AIF2 and ICE1 downregulated AIF2/ICE1-induced transactivation of CBF2 expression. AIF2 interacted preferentially with BIN2 and MPK3/6 during the early and later stages of cold acclimation, respectively, thereby differentially regulating AIF2 activity in a cold acclimation time-dependent manner. Moreover, AIF2 acted additively in a gain-of-function mutant of BRASSINAZOLE-RESISTANT 1 (BZR1; bzr1-1D) and a triple knockout mutant of BRASSINOSTEROID-INSENSITIVE 2 (BIN2) and its homologs (bin2bil1bil2) to induce CBFs-mediated freezing tolerance. This suggests that cold-induced AIF2 coordinates freezing tolerance along with BZR1 and BIN2, key positive and negative components, respectively, of brassinosteroid signaling pathways.

20.
Oncologist ; 29(6): e796-e802, 2024 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-38581718

RESUMO

BACKGROUND: A consolidation strategy has not been established for transplant-ineligible elderly patients with primary central nervous system lymphoma (PCNSL). In this study, we aimed to retrospectively evaluate the clinical outcomes of etoposide and cytarabine (EA) as consolidation chemotherapy for transplant-ineligible patients with PCNSL following high-dose methotrexate (MTX)-based induction chemotherapy. MATERIALS AND METHODS: Between 2015 and 2021, newly diagnosed transplant-ineligible patients with PCNSL with diffuse large B-cell lymphoma were consecutively enrolled. All enrolled patients were over 60 years old and received EA consolidation after achieving a complete or partial response following induction chemotherapy. RESULTS: Of the 85 patients who achieved a complete or partial response to MTX-based induction chemotherapy, 51 received EA consolidation chemotherapy. Among the 25 (49.0%, 25/51) patients in partial remission before EA consolidation, 56% (n = 14) achieved complete remission after EA consolidation. The median overall survival and progression-free survival were 43 and 13 months, respectively. Hematological toxicities were most common, and all patients experienced grade 4 neutropenia and thrombocytopenia. Forty-eight patients experienced febrile neutropenia during consolidation chemotherapy, and 4 patients died owing to treatment-related complications. CONCLUSION: EA consolidation chemotherapy for transplant-ineligible, elderly patients with PCNSL improved response rates but showed a high relapse rate and short progression-free survival. The incidences of treatment-related mortality caused by hematologic toxicities and severe infections were very high, even after dose modification. Therefore, the use of EA consolidation should be reconsidered in elderly patients with PCNSL.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica , Neoplasias do Sistema Nervoso Central , Quimioterapia de Consolidação , Citarabina , Etoposídeo , Humanos , Etoposídeo/administração & dosagem , Etoposídeo/uso terapêutico , Etoposídeo/efeitos adversos , Feminino , Masculino , Citarabina/administração & dosagem , Citarabina/efeitos adversos , Citarabina/uso terapêutico , Idoso , Neoplasias do Sistema Nervoso Central/tratamento farmacológico , Neoplasias do Sistema Nervoso Central/mortalidade , Quimioterapia de Consolidação/métodos , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Estudos Retrospectivos , Pessoa de Meia-Idade , Idoso de 80 Anos ou mais , Resultado do Tratamento , Linfoma Difuso de Grandes Células B/tratamento farmacológico , Linfoma Difuso de Grandes Células B/mortalidade
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