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1.
J Cell Sci ; 135(5)2022 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-33975358

RESUMO

Lipid droplets (LDs) are lipid-rich organelles universally found in most cells. They serve as a key energy reservoir, actively participate in signal transduction and dynamically communicate with other organelles. LD dysfunction has been associated with a variety of diseases. The content level, composition and mobility of LDs are crucial for their physiological and pathological functions, and these different parameters of LDs are subject to regulation by genetic factors and environmental inputs. Coherent Raman scattering (CRS) microscopy utilizes optical nonlinear processes to probe the intrinsic chemical bond vibration, offering label-free, quantitative imaging of lipids in vivo with high chemical specificity and spatiotemporal resolution. In this Review, we provide an overview over the principle of CRS microscopy and its application in tracking different parameters of LDs in live cells and organisms. We also discuss the use of CRS microscopy in genetic screens to discover lipid regulatory mechanisms and in understanding disease-related lipid pathology.


Assuntos
Microscopia , Análise Espectral Raman , Biologia , Gotículas Lipídicas , Lipídeos
2.
Artigo em Inglês | MEDLINE | ID: mdl-34521263

RESUMO

Fluorescent probes and mass spectrometry are the two most popular and complementary methods to quantify thiols in biological systems. In this review, we focus on the widely used and commercially available methods to detect and quantify thiols in living cells and the general approaches applied in mass spectrometry-based thiol quantification. We hope this review can serve as a general guide for redox biologists who are interested in thiol species.

3.
Nat Chem Biol ; 17(10): 1027-1036, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34552221

RESUMO

Aging is an inevitable biochemical process that adversely affects personal health and poses ever-increasing challenges to society. Recent research has revealed the crucial role of metabolism in regulating aging and longevity. During diverse metabolic processes, the host organism and their symbiotic partners-the microbiota-produce thousands of chemical products (metabolites). Emerging studies have uncovered specific metabolites that act as signaling molecules to actively regulate longevity. Here we review the latest progress in understanding the molecular mechanisms by which metabolites from the host and/or microbiota promote longevity. We also highlight state-of-the-art technologies for discovering, profiling and imaging aging- and longevity-regulating metabolites and for deciphering the molecular basis of their actions. The broad application of these technologies in aging research, together with future advances, will foster the systematic discovery of aging- and longevity-regulating metabolites and their signaling pathways. These metabolite signals should provide promising targets for developing new interventions to promote longevity and healthy aging.


Assuntos
Envelhecimento/fisiologia , Metabolismo Energético/fisiologia , Interações entre Hospedeiro e Microrganismos/fisiologia , Microbiota/fisiologia , Animais , Biomarcadores/metabolismo , Humanos , Longevidade/fisiologia
4.
6.
Aging Cell ; 20(8): e13432, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34247441

RESUMO

The rise of life expectancy of the human population is accompanied by the drastic increases of age-associated diseases, in particular Alzheimer's disease (AD), and underscores the need to understand how aging influences AD development. The Forkhead box O transcription factor 3 (FoxO3) is known to mediate aging and longevity downstream of insulin/insulin-like growth factor signaling across species. However, its function in the adult brain under physiological and pathological conditions is less understood. Here, we report a region and cell-type-specific regulation of FoxO3 in the central nervous system (CNS). We found that FoxO3 protein levels were reduced in the cortex, but not hippocampus, of aged mice. FoxO3 was responsive to insulin/AKT signaling in astrocytes, but not neurons. Using CNS Foxo3-deficient mice, we reveal that loss of FoxO3 led to cortical astrogliosis and altered lipid metabolism. This is associated with impaired metabolic homoeostasis and ß-amyloid (Aß) uptake in primary astrocyte cultures. These phenotypes can be reversed by expressing a constitutively active FOXO3 but not a FOXO3 mutant lacking the transactivation domain. Loss of FoxO3 in 5xFAD mice led to exacerbated Aß pathology and synapse loss and altered local response of astrocytes and microglia in the vicinity of Aß plaques. Astrocyte-specific overexpression of FOXO3 displayed opposite effects, suggesting that FoxO3 functions cell autonomously to mediate astrocyte activity and also interacts with microglia to address Aß pathology. Our studies support a protective role of astroglial FoxO3 against brain aging and AD.

7.
Artigo em Inglês | MEDLINE | ID: mdl-34312517
8.
J Vis Exp ; (171)2021 05 28.
Artigo em Inglês | MEDLINE | ID: mdl-34125101

RESUMO

Lipid metabolism is a fundamental physiological process necessary for cellular and organism health. Dysregulation of lipid metabolism often elicits obesity and many associated diseases including cardiovascular disorders, type II diabetes, and cancer. To advance the current understanding of lipid metabolic regulation, quantitative methods to precisely measure in vivo lipid storage levels in time and space have become increasingly important and useful. Traditional approaches to analyze lipid storage are semi-quantitative for microscopic assessment or lacking spatio-temporal information for biochemical measurement. Stimulated Raman scattering (SRS) microscopy is a label-free chemical imaging technology that enables rapid and quantitative detection of lipids in live cells with a subcellular resolution. As the contrast is exploited from intrinsic molecular vibrations, SRS microscopy also permits four-dimensional tracking of lipids in live animals. In the last decade, SRS microscopy has been widely used for small molecule imaging in biomedical research and overcome the major limitations of conventional fluorescent staining and lipid extraction methods. In the laboratory, we have combined SRS microscopy with the genetic and biochemical tools available to the powerful model organism, Caenorhabditis elegans, to investigate the distribution and heterogeneity of lipid droplets across different cells and tissues and ultimately to discover novel conserved signaling pathways that modulate lipid metabolism. Here, we present the working principles and the detailed setup of the SRS microscope and provide methods for its use in quantifying lipid storage at distinct developmental timepoints of wild-type and insulin signaling deficient mutant C. elegans.


Assuntos
Caenorhabditis elegans , Metabolismo dos Lipídeos , Animais , Diabetes Mellitus Tipo 2 , Humanos , Lipídeos , Microscopia , Microscopia Óptica não Linear , Análise Espectral Raman
9.
Science ; 372(6545): 984-989, 2021 05 28.
Artigo em Inglês | MEDLINE | ID: mdl-34045355

RESUMO

We investigated genome folding across the eukaryotic tree of life. We find two types of three-dimensional (3D) genome architectures at the chromosome scale. Each type appears and disappears repeatedly during eukaryotic evolution. The type of genome architecture that an organism exhibits correlates with the absence of condensin II subunits. Moreover, condensin II depletion converts the architecture of the human genome to a state resembling that seen in organisms such as fungi or mosquitoes. In this state, centromeres cluster together at nucleoli, and heterochromatin domains merge. We propose a physical model in which lengthwise compaction of chromosomes by condensin II during mitosis determines chromosome-scale genome architecture, with effects that are retained during the subsequent interphase. This mechanism likely has been conserved since the last common ancestor of all eukaryotes.


Assuntos
Adenosina Trifosfatases/genética , Adenosina Trifosfatases/fisiologia , Evolução Biológica , Cromossomos/ultraestrutura , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/fisiologia , Eucariotos/genética , Genoma , Complexos Multiproteicos/genética , Complexos Multiproteicos/fisiologia , Adenosina Trifosfatases/química , Algoritmos , Animais , Nucléolo Celular/ultraestrutura , Núcleo Celular/ultraestrutura , Centrômero/ultraestrutura , Cromossomos/química , Cromossomos Humanos/química , Cromossomos Humanos/ultraestrutura , Proteínas de Ligação a DNA/química , Genoma Humano , Genômica , Heterocromatina/ultraestrutura , Humanos , Interfase , Mitose , Modelos Biológicos , Complexos Multiproteicos/química , Telômero/ultraestrutura
10.
Dev Cell ; 56(10): 1394-1407, 2021 05 17.
Artigo em Inglês | MEDLINE | ID: mdl-33891896

RESUMO

Lipids play crucial roles in regulating aging and longevity. In the past few decades, a series of genetic pathways have been discovered to regulate lifespan in model organisms. Interestingly, many of these regulatory pathways are linked to lipid metabolism and lipid signaling. Lipid metabolic enzymes undergo significant changes during aging and are regulated by different longevity pathways. Lipids also actively modulate lifespan and health span as signaling molecules. In this review, we summarize recent insights into the roles of lipid metabolism and lipid signaling in aging and discuss lipid-related interventions in promoting longevity.


Assuntos
Metabolismo dos Lipídeos , Lipídeos/química , Longevidade/fisiologia , Transdução de Sinais , Animais , Humanos , Lipoproteínas/metabolismo , Receptores de Superfície Celular/metabolismo
11.
Elife ; 92020 12 16.
Artigo em Inglês | MEDLINE | ID: mdl-33325823

RESUMO

Gut microbial metabolism is associated with host longevity. However, because it requires direct manipulation of microbial metabolism in situ, establishing a causal link between these two processes remains challenging. We demonstrate an optogenetic method to control gene expression and metabolite production from bacteria residing in the host gut. We genetically engineer an Escherichia coli strain that secretes colanic acid (CA) under the quantitative control of light. Using this optogenetically-controlled strain to induce CA production directly in the Caenorhabditis elegans gut, we reveal the local effect of CA in protecting intestinal mitochondria from stress-induced hyper-fragmentation. We also demonstrate that the lifespan-extending effect of this strain is positively correlated with the intensity of green light, indicating a dose-dependent CA benefit on the host. Thus, optogenetics can be used to achieve quantitative and temporal control of gut bacterial metabolism in order to reveal its local and systemic effects on host health and aging.


Assuntos
Caenorhabditis elegans/microbiologia , Escherichia coli/metabolismo , Microbioma Gastrointestinal/fisiologia , Optogenética , Polissacarídeos/biossíntese , Animais , Regulação Bacteriana da Expressão Gênica/fisiologia , Longevidade/fisiologia
12.
Nat Commun ; 11(1): 4268, 2020 08 26.
Artigo em Inglês | MEDLINE | ID: mdl-32848159

RESUMO

Current efforts in the proteolysis targeting chimera (PROTAC) field mostly focus on choosing an appropriate E3 ligase for the target protein, improving the binding affinities towards the target protein and the E3 ligase, and optimizing the PROTAC linker. However, due to the large molecular weights of PROTACs, their cellular uptake remains an issue. Through comparing how different warhead chemistry, reversible noncovalent (RNC), reversible covalent (RC), and irreversible covalent (IRC) binders, affects the degradation of Bruton's Tyrosine Kinase (BTK), we serendipitously discover that cyano-acrylamide-based reversible covalent chemistry can significantly enhance the intracellular accumulation and target engagement of PROTACs and develop RC-1 as a reversible covalent BTK PROTAC with a high target occupancy as its corresponding kinase inhibitor and effectiveness as a dual functional inhibitor and degrader, a different mechanism-of-action for PROTACs. Importantly, this reversible covalent strategy is generalizable to improve other PROTACs, opening a path to enhance PROTAC efficacy.


Assuntos
Tirosina Quinase da Agamaglobulinemia/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Acrilamidas/química , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Tirosina Quinase da Agamaglobulinemia/genética , Linhagem Celular , Sobrevivência Celular , Corantes Fluorescentes , Meia-Vida , Humanos , Espaço Intracelular/metabolismo , Ligantes , Simulação de Dinâmica Molecular , Mutação , Fenômenos de Química Orgânica , Ligação Proteica , Domínios e Motivos de Interação entre Proteínas , Proteólise
13.
Trends Biochem Sci ; 45(11): 978-991, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32624271

RESUMO

Lysosomes transcend the role of degradation stations, acting as key nodes for interorganelle crosstalk and signal transduction. Lysosomes communicate with the nucleus through physical proximity and functional interaction. In response to external and internal stimuli, lysosomes actively adjust their distribution between peripheral and perinuclear regions and modulate lysosome-nucleus signaling pathways; in turn, the nucleus fine-tunes lysosomal biogenesis and functions through transcriptional controls. Changes in coordination between these two essential organelles are associated with metabolic disorders, neurodegenerative diseases, and aging. In this review, we address recent advances in lysosome-nucleus communication by multi-tiered regulatory mechanisms and discuss how these regulations couple metabolic inputs with organellar motility, cellular signaling, and transcriptional network.


Assuntos
Núcleo Celular/metabolismo , Lisossomos/metabolismo , Animais , Núcleo Celular/química , Núcleo Celular/genética , Redes Reguladoras de Genes , Humanos , Lisossomos/química , Lisossomos/genética , Transdução de Sinais
14.
Nat Commun ; 11(1): 1450, 2020 03 19.
Artigo em Inglês | MEDLINE | ID: mdl-32193370

RESUMO

Olfactory and metabolic dysfunctions are intertwined phenomena associated with obesity and neurodegenerative diseases; yet how mechanistically olfaction regulates metabolic homeostasis remains unclear. Specificity of olfactory perception integrates diverse environmental odors and olfactory neurons expressing different receptors. Here, we report that specific but not all olfactory neurons actively regulate fat metabolism without affecting eating behaviors in Caenorhabditis elegans, and identified specific odors that reduce fat mobilization via inhibiting these neurons. Optogenetic activation or inhibition of the responsible olfactory neural circuit promotes the loss or gain of fat storage, respectively. Furthermore, we discovered that FLP-1 neuropeptide released from this olfactory neural circuit signals through peripheral NPR-4/neuropeptide receptor, SGK-1/serum- and glucocorticoid-inducible kinase, and specific isoforms of DAF-16/FOXO transcription factor to regulate fat storage. Our work reveals molecular mechanisms underlying olfactory regulation of fat metabolism, and suggests the association between olfactory perception specificity of each individual and his/her susceptibility to the development of obesity.


Assuntos
Comportamento Alimentar/fisiologia , Metabolismo dos Lipídeos/fisiologia , Sistemas Neurossecretores/metabolismo , Obesidade/metabolismo , Percepção Olfatória/fisiologia , Animais , Animais Geneticamente Modificados , Butanonas/química , Caenorhabditis elegans , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Modelos Animais de Doenças , Fatores de Transcrição Forkhead/genética , Fatores de Transcrição Forkhead/metabolismo , Humanos , Neurônios/metabolismo , Neuropeptídeos/metabolismo , Odorantes , Optogenética , Proteínas Serina-Treonina Quinases/metabolismo , Receptores de Neuropeptídeos/metabolismo
15.
Hepatology ; 71(3): 1055-1069, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31355949

RESUMO

BACKGROUND AND AIMS: Liver receptor homolog-1 (LRH-1; NR5A2) is a nuclear receptor that regulates metabolic homeostasis in the liver. Previous studies identified phosphatidylcholines as potential endogenous agonist ligands for LRH-1. In the liver, distinct subsets of phosphatidylcholine species are generated by two different pathways: choline addition to phosphatidic acid through the Kennedy pathway and trimethylation of phosphatidylethanolamine through phosphatidylethanolamine N-methyl transferase (PEMT). APPROACH AND RESULTS: Here, we report that a PEMT-LRH-1 pathway specifically couples methyl metabolism and mitochondrial activities in hepatocytes. We show that the loss of Lrh-1 reduces mitochondrial number, basal respiration, beta-oxidation, and adenosine triphosphate production in hepatocytes and decreases expression of mitochondrial biogenesis and beta-oxidation genes. In contrast, activation of LRH-1 by its phosphatidylcholine agonists exerts opposite effects. While disruption of the Kennedy pathway does not affect the LRH-1-mediated regulation of mitochondrial activities, genetic or pharmaceutical inhibition of the PEMT pathway recapitulates the effects of Lrh-1 knockdown on mitochondria. Furthermore, we show that S-adenosyl methionine, a cofactor required for PEMT, is sufficient to induce Lrh-1 transactivation and consequently mitochondrial biogenesis. CONCLUSIONS: A PEMT-LRH-1 axis regulates mitochondrial biogenesis and beta-oxidation in hepatocytes.


Assuntos
Hepatócitos/metabolismo , Mitocôndrias/fisiologia , Fosfatidiletanolamina N-Metiltransferase/fisiologia , Receptores Citoplasmáticos e Nucleares/fisiologia , Animais , Células Hep G2 , Humanos , Masculino , Camundongos , Oxirredução , S-Adenosilmetionina/metabolismo , S-Adenosilmetionina/farmacologia
16.
G3 (Bethesda) ; 10(1): 189-198, 2020 01 07.
Artigo em Inglês | MEDLINE | ID: mdl-31712257

RESUMO

The relationship of genotypes to phenotypes can be modified by environmental inputs. Such crucial environmental inputs include metabolic cues derived from microbes living together with animals. Thus, the analysis of genetic effects on animals' physiology can be confounded by variations in the metabolic profile of microbes. Caenorhabditis elegans exposed to distinct bacterial strains and species exhibit phenotypes different at cellular, developmental, and behavioral levels. Here we reported metabolomic profiles of three Escherichia coli strains, B strain OP50, K-12 strain MG1655, and B-K-12 hybrid strain HB101, as well as different mitochondrial and fat storage phenotypes of C. elegans exposed to MG1655 and HB101 vs. OP50. We found that these metabolic phenotypes of C. elegans are not correlated with overall metabolic patterning of bacterial strains, but their specific metabolites. In particular, the fat storage phenotype is traced to the betaine level in different bacterial strains. HT115 is another K-12 E. coli strain that is commonly utilized to elicit an RNA interference response, and we showed that C. elegans exposed to OP50 and HT115 exhibit differences in mitochondrial morphology and fat storage levels. We thus generated an RNA interference competent OP50 (iOP50) strain that can robustly and consistently knockdown endogenous C. elegans genes in different tissues. Together, these studies suggest the importance of specific bacterial metabolites in regulating the host's physiology and provide a tool to prevent confounding effects when analyzing genotype-phenotype interactions under different bacterial backgrounds.


Assuntos
Interações Hospedeiro-Patógeno , Metaboloma , Interferência de RNA , Animais , Caenorhabditis elegans , Escherichia coli , Mitocôndrias/metabolismo , Fenótipo
17.
Trends Cell Biol ; 29(11): 876-887, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31611045

RESUMO

Lysosomes are sites of active metabolism in a cell. They contain various hydrolases that degrade extracellular and intracellular materials during endocytosis and autophagy, respectively. In addition to their long-recognized roles in degradation and recycling, emerging studies have revealed that lysosomes are organizing centers for signal transduction. Lysosome-derived signaling plays crucial roles in regulating nutrient sensing, metabolic adaptation, organelle crosstalk, and aging. In particular, how the degradative role of the lysosome cooperates with its signaling functions to actively modulate lifespan is beginning to be unraveled. This review describes recent advances in the role of the lysosome as a 'signaling hub' that uses three different lysosome-derived signaling pathways to integrate metabolic inputs, organelle interactions, and the control of longevity.


Assuntos
Autofagia/fisiologia , Endocitose/fisiologia , Lisossomos/metabolismo , Transdução de Sinais/fisiologia , Proteínas Quinases Ativadas por AMP/metabolismo , Animais , Humanos , Longevidade/fisiologia , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Mitocôndrias/metabolismo
18.
Sci Rep ; 9(1): 9966, 2019 07 10.
Artigo em Inglês | MEDLINE | ID: mdl-31292465

RESUMO

The lysosome plays a crucial role in the regulation of longevity. Lysosomal degradation is tightly coupled with autophagy that is induced by many longevity paradigms and required for lifespan extension. The lysosome also serves as a hub for signal transduction and regulates longevity via affecting nuclear transcription. One lysosome-to-nucleus retrograde signaling pathway is mediated by a lysosome-associated fatty acid binding protein LBP-8 in Caenorhabditis elegans. LBP-8 shuttles lysosomal lipids into the nucleus to activate lipid regulated nuclear receptors NHR-49 and NHR-80 and consequently promote longevity. However, the structural basis of LBP-8 action remains unclear. Here, we determined the first 1.3 Å high-resolution structure of this life-extending protein LBP-8, which allowed us to identify a structurally conserved nuclear localization signal and amino acids involved in lipid binding. Additionally, we described the range of fatty acids LBP-8 is capable of binding and show that it binds to life-extending ligands in worms such as oleic acid and oleoylethanolamide with high affinity.


Assuntos
Proteínas de Caenorhabditis elegans/química , Caenorhabditis elegans/metabolismo , Núcleo Celular/metabolismo , Ácidos Graxos/metabolismo , Longevidade/fisiologia , Lisossomos/metabolismo , Chaperonas Moleculares/química , Sequência de Aminoácidos , Animais , Proteínas de Ligação a Ácido Graxo/metabolismo , Sequências Hélice-Volta-Hélice
19.
Cell ; 177(2): 221-222, 2019 04 04.
Artigo em Inglês | MEDLINE | ID: mdl-30951663

RESUMO

Zhou et al. challenge the well-known beneficial effect of autophagy in promoting longevity. Evidence presented demonstrate that autophagy induction coupled with increased mitochondrial permeability is detrimental to organismal health in both the nematode Caenorhabditis elegans and mammals.


Assuntos
Autofagia , Proteínas de Caenorhabditis elegans , Animais , Caenorhabditis elegans , Longevidade , Permeabilidade
20.
Dev Cell ; 49(1): 7-9, 2019 04 08.
Artigo em Inglês | MEDLINE | ID: mdl-30965036

RESUMO

Bacterial avoidance and innate immune response are two ways by which C. elegans respond to pathogenic bacteria. In this issue of Developmental Cell, Kumar et al. (2019) and Singh and Aballay (2019) demonstrate that bacterial colonization is essential to induce both responses, which may be associated with somatic and reproductive longevity.


Assuntos
Proteínas de Caenorhabditis elegans , Caenorhabditis elegans , Animais , Imunidade Inata , Longevidade , Transdução de Sinais
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