RESUMO
Mutations in leucine-rich repeat kinase 2 (LRRK2) are commonly implicated in the pathogenesis of both familial and sporadic Parkinson's disease (PD). LRRK2 regulates critical cellular processes at membranous organelles and forms microtubule-based pathogenic filaments, yet the molecular basis underlying these biological roles of LRRK2 remains largely enigmatic. Here, we determined high-resolution structures of full-length human LRRK2, revealing its architecture and key interdomain scaffolding elements for rationalizing disease-causing mutations. The kinase domain of LRRK2 is captured in an inactive state, a conformation also adopted by the most common PD-associated mutation, LRRK2G2019S. This conformation serves as a framework for structure-guided design of conformational specific inhibitors. We further determined the structure of COR-mediated LRRK2 dimers and found that single-point mutations at the dimer interface abolished pathogenic filamentation in cells. Overall, our study provides mechanistic insights into physiological and pathological roles of LRRK2 and establishes a structural template for future therapeutic intervention in PD.
Assuntos
Serina-Treonina Proteína Quinase-2 com Repetições Ricas em Leucina/química , Sequência de Aminoácidos , Células HEK293 , Humanos , Serina-Treonina Proteína Quinase-2 com Repetições Ricas em Leucina/ultraestrutura , Modelos Moleculares , Domínios Proteicos , Multimerização Proteica , Estrutura Secundária de ProteínaRESUMO
KCNQ1, also known as Kv7.1, is a voltage-dependent K+ channel that regulates gastric acid secretion, salt and glucose homeostasis, and heart rhythm. Its functional properties are regulated in a tissue-specific manner through co-assembly with beta subunits KCNE1-5. In non-excitable cells, KCNQ1 forms a complex with KCNE3, which suppresses channel closure at negative membrane voltages that otherwise would close it. Pore opening is regulated by the signaling lipid PIP2. Using cryoelectron microscopy (cryo-EM), we show that KCNE3 tucks its single-membrane-spanning helix against KCNQ1, at a location that appears to lock the voltage sensor in its depolarized conformation. Without PIP2, the pore remains closed. Upon addition, PIP2 occupies a site on KCNQ1 within the inner membrane leaflet, which triggers a large conformational change that leads to dilation of the pore's gate. It is likely that this mechanism of PIP2 activation is conserved among Kv7 channels.
Assuntos
Canal de Potássio KCNQ1/metabolismo , Canal de Potássio KCNQ1/ultraestrutura , Microscopia Crioeletrônica , Humanos , Ativação do Canal Iônico/fisiologia , Canal de Potássio KCNQ1/química , Potenciais da Membrana/fisiologia , Técnicas de Patch-Clamp , Fosfatidilinositol 4,5-Difosfato/metabolismo , Canais de Potássio de Abertura Dependente da Tensão da Membrana/química , Canais de Potássio de Abertura Dependente da Tensão da Membrana/metabolismo , Canais de Potássio de Abertura Dependente da Tensão da Membrana/ultraestruturaRESUMO
KCNQ1 is the pore-forming subunit of cardiac slow-delayed rectifier potassium (IKs) channels. Mutations in the kcnq1 gene are the leading cause of congenital long QT syndrome (LQTS). Here, we present the cryoelectron microscopy (cryo-EM) structure of a KCNQ1/calmodulin (CaM) complex. The conformation corresponds to an "uncoupled," PIP2-free state of KCNQ1, with activated voltage sensors and a closed pore. Unique structural features within the S4-S5 linker permit uncoupling of the voltage sensor from the pore in the absence of PIP2. CaM contacts the KCNQ1 voltage sensor through a specific interface involving a residue on CaM that is mutated in a form of inherited LQTS. Using an electrophysiological assay, we find that this mutation on CaM shifts the KCNQ1 voltage-activation curve. This study describes one physiological form of KCNQ1, depolarized voltage sensors with a closed pore in the absence of PIP2, and reveals a regulatory interaction between CaM and KCNQ1 that may explain CaM-mediated LQTS.
Assuntos
Calmodulina/química , Canal de Potássio KCNQ1/química , Síndrome do QT Longo/metabolismo , Sequência de Aminoácidos , Animais , Calmodulina/metabolismo , Microscopia Crioeletrônica , Humanos , Canal de Potássio KCNQ1/genética , Canal de Potássio KCNQ1/metabolismo , Modelos Moleculares , Mutação , Alinhamento de Sequência , Xenopus laevisRESUMO
KRAS is the most frequently mutated oncogene in cancer and encodes a key signalling protein in tumours1,2. The KRAS(G12C) mutant has a cysteine residue that has been exploited to design covalent inhibitors that have promising preclinical activity3-5. Here we optimized a series of inhibitors, using novel binding interactions to markedly enhance their potency and selectivity. Our efforts have led to the discovery of AMG 510, which is, to our knowledge, the first KRAS(G12C) inhibitor in clinical development. In preclinical analyses, treatment with AMG 510 led to the regression of KRASG12C tumours and improved the anti-tumour efficacy of chemotherapy and targeted agents. In immune-competent mice, treatment with AMG 510 resulted in a pro-inflammatory tumour microenvironment and produced durable cures alone as well as in combination with immune-checkpoint inhibitors. Cured mice rejected the growth of isogenic KRASG12D tumours, which suggests adaptive immunity against shared antigens. Furthermore, in clinical trials, AMG 510 demonstrated anti-tumour activity in the first dosing cohorts and represents a potentially transformative therapy for patients for whom effective treatments are lacking.
Assuntos
Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/imunologia , Piperazinas/farmacologia , Piperazinas/uso terapêutico , Proteínas Proto-Oncogênicas p21(ras)/antagonistas & inibidores , Piridinas/farmacologia , Piridinas/uso terapêutico , Pirimidinas/farmacologia , Pirimidinas/uso terapêutico , Animais , Antineoplásicos/administração & dosagem , Antineoplásicos/química , Proliferação de Células/efeitos dos fármacos , Sinergismo Farmacológico , Humanos , Imunoterapia , Inflamação/induzido quimicamente , Inflamação/imunologia , Inflamação/patologia , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Camundongos , Fosforilação/efeitos dos fármacos , Piperazinas/administração & dosagem , Piperazinas/química , Proteínas Proto-Oncogênicas p21(ras)/genética , Piridinas/administração & dosagem , Piridinas/química , Pirimidinas/administração & dosagem , Pirimidinas/química , Transdução de Sinais/efeitos dos fármacos , Resultado do Tratamento , Microambiente Tumoral/efeitos dos fármacos , Microambiente Tumoral/imunologiaRESUMO
DNA polymerase θ (Pol θ) plays an essential role in the microhomology-mediated end joining (MMEJ) pathway for repairing DNA double-strand breaks. However, the mechanisms by which Pol θ recognizes microhomologous DNA ends and performs low-fidelity DNA synthesis remain unclear. Here, we present cryo-electron microscope structures of the polymerase domain of Lates calcarifer Pol θ with long and short duplex DNA at up to 2.4 Šresolution. Interestingly, Pol θ binds to long and short DNA substrates similarly, with extensive interactions around the active site. Moreover, Pol θ shares a similar active site as high-fidelity A-family polymerases with its finger domain well-closed but differs in having hydrophilic residues surrounding the nascent base pair. Computational simulations and mutagenesis studies suggest that the unique insertion loops of Pol θ help to stabilize short DNA binding and assemble the active site for MMEJ repair. Taken together, our results illustrate the structural basis of Pol θ-mediated MMEJ.
Assuntos
Reparo do DNA por Junção de Extremidades , DNA Polimerase Dirigida por DNA , Perciformes , Quebras de DNA de Cadeia Dupla , DNA Polimerase Dirigida por DNA/metabolismo , Perciformes/classificação , Perciformes/metabolismo , DNA Polimerase tetaRESUMO
Albuminuria is a hallmark of glomerular disease of various etiologies. It is not only a symptom of glomerular disease but also a cause leading to glomerulosclerosis, interstitial fibrosis, and eventually, a decline in kidney function. The molecular mechanism underlying albuminuria-induced kidney injury remains poorly defined. In our genetic model of nephrotic syndrome (NS), we have identified CHOP (C/EBP homologous protein)-TXNIP (thioredoxin-interacting protein) as critical molecular linkers between albuminuria-induced ER dysfunction and mitochondria dyshomeostasis. TXNIP is a ubiquitously expressed redox protein that binds to and inhibits antioxidant enzyme, cytosolic thioredoxin 1 (Trx1), and mitochondrial Trx2. However, very little is known about the regulation and function of TXNIP in NS. By utilizing Chop-/- and Txnip-/- mice as well as 68Ga-Galuminox, our molecular imaging probe for detection of mitochondrial reactive oxygen species (ROS) in vivo, we demonstrate that CHOP up-regulation induced by albuminuria drives TXNIP shuttling from nucleus to mitochondria, where it is required for the induction of mitochondrial ROS. The increased ROS accumulation in mitochondria oxidizes Trx2, thus liberating TXNIP to associate with mitochondrial nod-like receptor protein 3 (NLRP3) to activate inflammasome, as well as releasing mitochondrial apoptosis signal-regulating kinase 1 (ASK1) to induce mitochondria-dependent apoptosis. Importantly, inhibition of TXNIP translocation and mitochondrial ROS overproduction by CHOP deletion suppresses NLRP3 inflammasome activation and p-ASK1-dependent mitochondria apoptosis in NS. Thus, targeting TXNIP represents a promising therapeutic strategy for the treatment of NS.
Assuntos
Albuminúria , Proteínas de Transporte , Rim , Mitocôndrias , Síndrome Nefrótica , Tiorredoxinas , Fator de Transcrição CHOP , Albuminúria/complicações , Albuminúria/genética , Albuminúria/prevenção & controle , Animais , Apoptose , Proteínas de Transporte/metabolismo , Núcleo Celular/metabolismo , Deleção de Genes , Inflamassomos/metabolismo , Rim/metabolismo , Rim/patologia , MAP Quinase Quinase Quinase 5/metabolismo , Camundongos , Mitocôndrias/metabolismo , Proteínas Mitocondriais/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Síndrome Nefrótica/complicações , Síndrome Nefrótica/genética , Síndrome Nefrótica/patologia , Síndrome Nefrótica/prevenção & controle , Espécies Reativas de Oxigênio/metabolismo , Tiorredoxinas/metabolismo , Fator de Transcrição CHOP/deficiência , Fator de Transcrição CHOP/genética , Fator de Transcrição CHOP/metabolismoRESUMO
Magnetic proximity-induced magnetism in paramagnetic LaNiO3 (LNO) has spurred intensive investigations in the past decade. However, no consensus has been reached so far regarding the magnetic order in LNO layers in relevant heterostructures. This paper reports a layered ferromagnetic structure for the (111)-oriented LNO/LaMnO3 (LMO) superlattices. It is found that each period of the superlattice consisted of an insulating LNO-interfacial phase (five unit cells in thickness, â¼1.1 nm), a metallic LNO-inner phase, a poorly conductive LMO-interfacial phase (three unit cells in thickness, â¼0.7 nm), and an insulating LMO-inner phase. All four of these phases are ferromagnetic, showing different magnetizations. The Mn-to-Ni interlayer charge transfer is responsible for the emergence of a layered magnetic structure, which may cause magnetic interaction across the LNO/LMO interface and double exchange within the LMO-interfacial layer. This work indicates that the proximity effect is an effective means of manipulating the magnetic state and associated properties of complex oxides.
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Telomerase reactivation is implicated in approximately 85% of human cancers, yet its underlying mechanism remains elusive. In this study, we elucidate that the cullin-RING ubiquitin ligase 4 (CRL4) complex drives the reactivation of human telomerase reverse transcriptase (hTERT) in colorectal cancer (CRC) by degrading the tumor suppressor, menin 1 (MEN1). Our data show that, in noncancerous intestinal epithelial cells, the transcription factor specificity protein 1 (Sp1) recruits both the histone acetyltransferase p300 and MEN1 to suppress hTERT expression, thus maintaining telomere shortness post-cell division. Inflammation-induced microenvironments trigger an activation of the CRL4DCAF4 E3 ligase, leading to MEN1 ubiquitination and degradation in CRC cells. This process nullifies MEN1's inhibitory action, reactivates hTERT expression at the transcriptional level, interrupts telomere shortening and spurs uncontrolled cellular proliferation. Notably, MEN1 overexpression in CRC cells partially counteracts these oncogenic phenotypes. NSC1517, an inhibitor of the CRL4DCAF4 complex identified through high-throughput screening from a plant-derived chemical pool, hinders MEN1 degradation, attenuates hTERT expression and suppresses tumor growth in mouse xenograft models. Collectively, our research elucidates the transcriptional mechanism driving hTERT reactivation in CRC. Targeting the CRL4DCAF4 E3 ligase emerges as a promising strategy to counteract cancer cell immortalization and curb tumor progression.
Assuntos
Proliferação de Células , Neoplasias Colorretais , Telomerase , Ubiquitina-Proteína Ligases , Humanos , Neoplasias Colorretais/patologia , Neoplasias Colorretais/genética , Neoplasias Colorretais/metabolismo , Telomerase/genética , Telomerase/metabolismo , Animais , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitina-Proteína Ligases/genética , Camundongos , Regulação Neoplásica da Expressão Gênica , Proteínas Proto-Oncogênicas/metabolismo , Proteínas Proto-Oncogênicas/genética , Camundongos Nus , Ubiquitinação , Ensaios Antitumorais Modelo de Xenoenxerto , Linhagem Celular Tumoral , Proteínas NuclearesRESUMO
Arabidopsis RESISTANCE TO POWDERY MILDEW 8.1 (RPW8.1) is an important tool for engineering broad-spectrum disease resistance against multiple pathogens. Ectopic expression of RPW8.1 leads to enhanced disease resistance with cell death at leaves and compromised plant growth, implying a regulatory mechanism balancing RPW8.1-mediated resistance and growth. Here, we show that RPW8.1 constitutively enhances the expression of transcription factor WRKY51 and activates salicylic acid and ethylene signalling pathways; WRKY51 in turn suppresses RPW8.1 expression, forming a feedback regulation loop. RPW8.1 and WRKY51 are both induced by pathogen infection and pathogen-/microbe-associated molecular patterns. In ectopic expression of RPW8.1 background (R1Y4), overexpression of WRKY51 not only rescues the growth suppression and cell death caused by RPW8.1, but also suppresses RPW8.1-mediated broad-spectrum disease resistance and pattern-triggered immunity. Mechanistically, WRKY51 directly binds to and represses RPW8.1 promoter, thus limiting the expression amplitude of RPW8.1. Moreover, WRKY6, WRKY28 and WRKY41 play a role redundant to WRKY51 in the suppression of RPW8.1 expression and are constitutively upregulated in R1Y4 plants with WRKY51 being knocked out (wrky51 R1Y4) plants. Notably, WRKY51 has no significant effects on disease resistance or plant growth in wild type without RPW8.1, indicating a specific role in RPW8.1-mediated disease resistance. Altogether, our results reveal a regulatory circuit controlling the accumulation of RPW8.1 to an appropriate level to precisely balance growth and disease resistance during pathogen invasion.
Assuntos
Proteínas de Arabidopsis , Arabidopsis , Proteínas de Arabidopsis/metabolismo , Resistência à Doença/genética , Retroalimentação , Arabidopsis/metabolismo , Morte Celular , Doenças das Plantas/genética , Regulação da Expressão Gênica de Plantas/genéticaRESUMO
Mast cells (MCs) are important intermediates between the nervous and immune systems. The cardiac autonomic nervous system (CANS) crucially modulates cardiac electrophysiology and arrhythmogenesis, but whether and how MC-CANS neuroimmune interaction influences arrhythmia remain unclear. Our clinical data showed a close relationship between serum levels of MC markers and CANS activity, and then we use mast cell stabilizers (MCSs) to alter this MC-CANS communication. MCSs, which are well-known anti-allergic agents, could reduce the risk of ventricular arrhythmia (VA) after myocardial infarction (MI). RNA-sequencing (RNA-seq) analysis to investigate the underlying mechanism by which MCSs could affect the left stellate ganglion (LSG), a key therapeutic target for modulating CANS, showed that the IL-6 and γ-aminobutyric acid (GABA)-ergic system may be involved in this process. Our findings demonstrated that MCSs reduce VA risk along with revealing the potential underlying antiarrhythmic mechanisms.
Assuntos
Antialérgicos , Estabilizadores de Mastócitos , Humanos , Neuroimunomodulação , Arritmias Cardíacas/prevenção & controle , CoraçãoRESUMO
BACKGROUND: Although it is thought that prostatitis or benign prostatic hyperplasia (BPH) is related to prostate cancer (PCa), the underlying causal effects of these diseases are unclear. METHODS: We assessed the causal relationship between prostatitis or BPH and PCa using a two-sample Mendelian randomization (MR) approach. The data utilized in this study were sourced from genome-wide association study. The association of genetic variants from cohorts of prostatitis or BPH and PCa patients was determined using inverse-variance weighted and MR Egger regression techniques. The direction of chance was determined using independent genetic variants with genome-wide significance (P < 5 × 10-6). The accuracy of the results was confirmed using sensitivity analyses. RESULTS: MR analysis showed that BPH had a significant causal effect on PCa (Odds Ratio = 1.209, 95% Confidence Interval: 0.098-0.281, P = 5.079 × 10- 5) while prostatitis had no significant causal effect on PCa (P > 0.05). Additionally, the pleiotropic test and leave-one-out analysis showed the two-sample MR analyses were valid and reliable. CONCLUSIONS: This MR study supports that BPH has a positive causal effect on PCa, while genetically predicted prostatitis has no causal effect on PCa. Nonetheless, further studies should explore the underlying biochemical mechanism and potential therapeutic targets for the prevention of these diseases.
Assuntos
Estudo de Associação Genômica Ampla , Análise da Randomização Mendeliana , Hiperplasia Prostática , Neoplasias da Próstata , Prostatite , Humanos , Masculino , Neoplasias da Próstata/genética , Hiperplasia Prostática/genética , Prostatite/genética , Prostatite/complicações , Polimorfismo de Nucleotídeo Único , Predisposição Genética para DoençaRESUMO
The spontaneous generation of hydrogen peroxide (H2O2) within atmospheric microdroplets, such as raindrops and aerosols, plays a crucial role in various environmental processes including pollutant degradation and oxidative stress. However, quantifying hydroxyl radicals (â¢OH), essential for H2O2 formation, remains challenging due to their short lifespan and low concentration. This study addresses this gap by presenting a highly sensitive and selective surface-enhanced Raman scattering (SERS) nanosensor specifically designed for quantifying â¢OH within water microdroplets. Utilizing a phthalhydrazide (Phth) probe, the SERS technique enables rapid, interference-free detection of â¢OH at nanomolar concentrations. It achieves a linear detection range from 2 nM to 2 µM and a limit of detection as low as 0.34 nM. Importantly, the SERS sensor demonstrates robustness and accuracy within water microdroplets, paving the way for comprehensive mechanistic studies of H2O2 generation in the atmosphere. This innovative approach not only offers a powerful tool for environmental research but also holds potential for advancing our understanding of atmospheric H2O2 formation and its impact on air quality and pollutant degradation.
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A novel n-alkane- and phenolic acid-degrading Acinetobacter strain (designated C16S1T) was isolated from rhizosphere soil. The strain was identified as a novel species named Acinetobacter suaedae sp. nov. using a polyphasic taxonomic approach. Strain C16S1T showed preferential degradation of three compounds: p-hydroxybenzoate (PHBA) > ferulic acid (FA) > n-hexadecane. In a medium containing two or three of these allelochemicals, coexisting n-hexadecane and PHBA accelerated each other's degradation and that of FA. FA typically hindered the degradation of n-hexadecane but accelerated PHBA degradation. The upregulated expression of n-hexadecane- and PHBA-degrading genes induced, by their related substrates, was mutually enhanced by coexisting PHBA or n-hexadecane; in contrast, expression of both gene types was reduced by FA. Coexisting PHBA or n-hexadecane enhanced the upregulation of FA-degrading genes induced by FA. The expressions of degrading genes affected by coexisting chemicals coincided with the observed degradation efficiencies. Iron shortage limited the degradation efficiency of all three compounds and changed the degradation preference of Acinetobacter. The present study demonstrated that the biodegradability of the chemicals, the effects of coexisting chemicals on the expression of degrading genes and the strain's growth, the shortage of essential elements, and the toxicity of the chemicals were the four major factors affecting the removal rates of the coexisting allelochemicals.
Assuntos
Acinetobacter , Acinetobacter/genética , Alcanos/metabolismo , Alcanos/farmacologia , Genômica , Biodegradação AmbientalRESUMO
Phenolic acids (PAs) are widely distributed allelochemicals in various environments. To better understand the fate of PAs in environments, a halotolerant PAs-degrading bacterium (named strain RR2S18T) isolated from rhizosphere soil was identified as a novel species of Devosia, named Devosia rhizosphaerae sp. nov. The strain initially degraded PAs into central ring-fission intermediates (protocatechuic acid) using the CoA-dependent non-ß-oxidation pathway. The produced ring-fission intermediates were then consecutively degraded by an ortho-cleavage reaction and the ß-ketoadipic acid pathway. A comparative genomics analysis of 62 Devosia strains revealed that PAs-degrading genes were ubiquitous in their genomes, indicating that PAs degradation is universal among members of this genus. The analysis also suggested that the genes involved in CoA-dependent non-ß-oxidation are inherent to Devosia strains, while those involved in ring-fission and ß-ketoadipic acid pathways were obtained by horizontal gene transfer.
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Ubiquitin-specific proteases (USPs) constitute the largest family of deubiquitinating enzymes, whose catalytic competency is often modulated by their binding partners through unknown mechanisms. Here we report on a series of crystallographic and biochemical analyses of an evolutionarily conserved deubiquitinase, USP12, which is activated by two ß-propeller proteins, UAF1 and WDR20. Our structures reveal that UAF1 and WDR20 interact with USP12 at two distinct sites far from its catalytic center. Without increasing the substrate affinity of USP12, the two ß-propeller proteins potentiate the enzyme through different allosteric mechanisms. UAF1 docks at the distal end of the USP12 Fingers domain and induces a cascade of structural changes that reach a critical ubiquitin-contacting loop adjacent to the catalytic cleft. By contrast, WDR20 anchors at the base of this loop and remotely modulates the catalytic center of the enzyme. Our results provide a mechanistic example for allosteric activation of USPs by their regulatory partners.
Assuntos
Proteínas de Transporte/metabolismo , Proteínas Nucleares/metabolismo , Ubiquitina Tiolesterase/metabolismo , Regulação Alostérica , Sítios de Ligação , Proteínas de Transporte/química , Proteínas de Transporte/genética , Cumarínicos/metabolismo , Células HEK293 , Humanos , Hidrólise , Cinética , Modelos Moleculares , Complexos Multiproteicos , Proteínas Nucleares/química , Proteínas Nucleares/genética , Ligação Proteica , Conformação Proteica , Relação Estrutura-Atividade , Especificidade por Substrato , Transfecção , Ubiquitina Tiolesterase/química , Ubiquitina Tiolesterase/genética , Ubiquitinação , Ubiquitinas/metabolismoRESUMO
Magnetic skyrmions are scarcely investigated for single-crystal quality films, for which skyrmions may have a remarkable performance. Even in the limited studies in this aspect, the skyrmions are usually probed by the topological Hall effect, missing important information on dynamic properties. Here, we present a comprehensive investigation on the generation/manipulation of magnetic skyrmions in La0.67Ba0.33MnO3 single-crystal films. Using the technique of magnetic force microscopy, the current-driven skyrmion dynamics are directly observed. Unlike isolated skyrmions produced by magnetic field alone, closely packed skyrmions can be generated by electric pulses in a magnetic background, with a high density (â¼60/µm2) and a small size (dozens of nanometers). The threshold current moving skyrmions is â¼2.3 × 104 A/cm2, 2-3 orders of magnitude lower than that required by metallic multilayers or van der Waals ferromagnetic heterostructures. Our work demonstrates the great potential of single-crystal oxide films in developing skyrmion-based devices.
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Alzheimer's disease (AD) and Parkinson's disease (PD) are the most common neurodegenerative diseases, and they affect millions of people worldwide, particularly older individuals. Therefore, there is a clear need to develop novel drug targets for the treatment of age-related neurodegenerative diseases. Emerging evidence suggests that mitochondrial dysfunction and reactive oxygen species (ROS) generation play central roles in the onset and progression of neurodegenerative diseases. Mitochondria are key regulators of respiratory function, cellular energy adenosine triphosphate production, and the maintenance of cellular redox homeostasis, which are essential for cell survival. Mitochondrial morphology and function are tightly regulated by maintaining a balance among mitochondrial fission, fusion, biogenesis, and mitophagy. In this review, we provide an overview of the main functions of mitochondria, with a focus on recent progress highlighting the critical role of ROS-induced oxidative stress, dysregulated mitochondrial dynamics, mitochondrial apoptosis, mitochondria-associated inflammation, and impaired mitochondrial function in the pathogenesis of age-related neurodegenerative diseases, such as AD and PD. We also discuss the potential of mitochondrial fusion and biogenesis enhancers, mitochondrial fission inhibitors, and mitochondria-targeted antioxidants as novel drugs for the treatment of these diseases.
Assuntos
Mitocôndrias , Dinâmica Mitocondrial , Doenças Neurodegenerativas , Espécies Reativas de Oxigênio , Humanos , Espécies Reativas de Oxigênio/metabolismo , Mitocôndrias/metabolismo , Mitocôndrias/efeitos dos fármacos , Doenças Neurodegenerativas/metabolismo , Doenças Neurodegenerativas/tratamento farmacológico , Doenças Neurodegenerativas/patologia , Animais , Dinâmica Mitocondrial/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Antioxidantes/uso terapêutico , Antioxidantes/farmacologia , Doença de Parkinson/metabolismo , Doença de Parkinson/tratamento farmacológico , Doença de Parkinson/patologiaRESUMO
BACKGROUND: Auxin/indoleacetic acid (AUX/IAA) genes encoding short-lived proteins participate in AUX signaling transduction and play crucial roles in plant growth and development. Although the AUX/IAA gene family has been identified in many plants, a systematic analysis of AUX/IAA genes in Brassica rapa ssp. rapa has not yet been reported. RESULTS: We performed a comprehensive genome-wide analysis and found 89 AUX/IAA genes in turnip based on the conserved AUX/IAA domain (pfam02309). Phylogenetic analysis of AUX/IAA genes from turnip, Arabidopsis, and cabbage revealed that these genes cluster into six subgroups (A1, A2, A3, A4, B1, and B2). The motif distribution was also conservative among the internal members of the clade. Enhanced yellow fluorescent protein (EYFP) signals of BrrIAA-EYFPs showed that BrrIAA members functioned as nucleoproteins. Moreover, transcriptional analysis revealed that the expression patterns of AUX/IAA genes in turnip were tissue-dependent. Because orthologs have similar biological functions and interaction networks in plant growth and development, BrrIAA66 in turnip possibly played a role in embryo axis formation, vascular development, lateral root formation, and floral organ development by interacting with BrrARF19 and BrrTIR1. CONCLUSION: These results provide a theoretical basis for further investigation of BrrAUX/IAA genes and lay the foundation for functional analysis of BrrIAA66 in turnip.
Assuntos
Arabidopsis , Brassica napus , Brassica rapa , Brassica , Brassica napus/metabolismo , Brassica/metabolismo , Brassica rapa/genética , Brassica rapa/metabolismo , Filogenia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Ácidos Indolacéticos/metabolismo , Arabidopsis/genética , Regulação da Expressão Gênica de PlantasRESUMO
Electrochemical CO2 -to-CO conversion offers an attractive and efficient route to recycle CO2 greenhouse gas. Molecular catalysts, like CoPc, are proved to be possible replacement for precious metal-based catalysts. These molecules, a combination of metal center and organic ligand molecule, may evolve into single atom structure for enhanced performance; besides, the manipulation of molecules' behavior also plays an important role in mechanism research. Here, in this work, the structure evolution of CoPc molecules is investigated via electrochemical-induced activation process. After numbers of cyclic voltammetry scanning, CoPc molecular crystals become cracked and crumbled, meanwhile the released CoPc molecules migrate to the conductive substrate. Atomic-scale HAADF-STEM proves the migration of CoPc molecules, which is the main reason for the enhancement in CO2 -to-CO performance. The as-activated CoPc exhibits a maximum FECO of 99% in an H-type cell and affords a long-term durability at 100 mA cm-2 for 29.3 h in a membrane electrode assembly reactor. Density-functional theory (DFT) calculation also demonstrates a favorable CO2 activation energy with such an activated CoPc structure. This work provides a different perspective for understanding molecular catalysts as well as a reliable and universal method for practical utilization.
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BACKGROUND: Anatomical segmentectomy is a surgical procedure that completely removes a territory (or territories) of the third-order portal venous branches of a Couinaud segment (Wakabayashi et al. in J Hepatobil Pancreat Sci 29(1):82-98, 2022. https://doi.org/10.1002/jhbp.899 ). Laparoscopic segmentectomy of S8 is considered technically challenging because of the Precise dissection of the Glissonean pedicle of S8, and exposure of the middle and right hepatic veins are required (Ome et al. in J Am Coll Surg 230(3):e13-e20, 2020; Wakabayashi et al. in Ann Surg 261(4):619-29, 2015. https://doi.org/10.1097/sla.0000000000001184 ; Monden et al. in J Hepatobil Pancreat Sci 29(1):66-81, 2022. https://doi.org/10.1002/jhbp.898 ). This report describes a new approach, which can reduce unwanted damage to normal tissues and complications. METHODS: A 53-year-old man who has suffered from hepatitis B for 10 years was admitted for the treatment of two nodular tumors located in segment VIII. The surgical procedure began with the percutaneous injection of 5 mL, 0.025 mg/mL of ICG into the S8 portal branch by using an 18G PTCD needle under the guidance of laparoscopic ultrasound (Xu et al. in Surg Endosc 34(10):4683-4691, 2020. https://doi.org/10.1007/s00464-020-07691-5 ; Wang et al. in Ann Surg 274(1):97-106, 2021. https://doi.org/10.1097/sla.0000000000004718 ; Aoki et al. in J Am Coll Surg 230(3):e7-e12, 2020. https://doi.org/10.1016/j.jamcollsurg.2019.11.004 ), followed by liver transection on the cranial side of the liver, which used the ICG fluorescence images for exposing the roots of the middle and right hepatic veins and dissecting and ligating S8 portal pedicle. The excision specimen was sent for histopathological diagnosis. RESULTS: It took 200 min for the operation and 60 min for the total Pringle maneuver. The estimate of blood loss was 110 mL. The final histopathologic results of the two nodules were hepatocellular carcinoma (HCC). The patient was discharged on postoperative Day 6 with no complications. CONCLUSIONS: Laparoscopic anatomical liver resection of S8 has been demonstrated to be feasible. Under the guidance of laparoscopic ultrasonography, ICG positive staining was proven to be optimal for Anatomical segmentectomy.