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1.
Sci Transl Med ; 16(741): eadj5705, 2024 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-38569015

RESUMO

Cancer-associated fibroblasts (CAFs) are abundant stromal cells in the tumor microenvironment that promote cancer progression and relapse. However, the heterogeneity and regulatory roles of CAFs underlying chemoresistance remain largely unclear. Here, we performed a single-cell analysis using high-dimensional flow cytometry analysis and identified a distinct senescence-like tetraspanin-8 (TSPAN8)+ myofibroblastic CAF (myCAF) subset, which is correlated with therapeutic resistance and poor survival in multiple cohorts of patients with breast cancer (BC). TSPAN8+ myCAFs potentiate the stemness of the surrounding BC cells through secretion of senescence-associated secretory phenotype (SASP)-related factors IL-6 and IL-8 to counteract chemotherapy. NAD-dependent protein deacetylase sirtuin 6 (SIRT6) reduction was responsible for the senescence-like phenotype and tumor-promoting role of TSPAN8+ myCAFs. Mechanistically, TSPAN8 promoted the phosphorylation of ubiquitin E3 ligase retinoblastoma binding protein 6 (RBBP6) at Ser772 by recruiting MAPK11, thereby inducing SIRT6 protein destruction. In turn, SIRT6 down-regulation up-regulated GLS1 and PYCR1, which caused TSPAN8+ myCAFs to secrete aspartate and proline, and therefore proved a nutritional niche to support BC outgrowth. By demonstrating that TSPAN8+SIRT6low myCAFs were tightly associated with unfavorable disease outcomes, we proposed that the combined regimen of anti-TSPAN8 antibody and SIRT6 activator MDL-800 is a promising approach to overcome chemoresistance. These findings highlight that senescence contributes to CAF heterogeneity and chemoresistance and suggest that targeting TSPAN8+ myCAFs is a promising approach to circumvent chemoresistance.


Assuntos
Neoplasias da Mama , Fibroblastos Associados a Câncer , Sirtuínas , Humanos , Feminino , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/patologia , Fibroblastos Associados a Câncer/metabolismo , Fibroblastos Associados a Câncer/patologia , Resistencia a Medicamentos Antineoplásicos , Recidiva Local de Neoplasia/patologia , Fibroblastos/patologia , Microambiente Tumoral , Proteínas de Ligação a DNA , Ubiquitina-Proteína Ligases , Tetraspaninas/genética , Tetraspaninas/metabolismo
2.
Endocrinology ; 165(5)2024 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-38565429

RESUMO

NAD+ is one of the most important metabolites for cellular activities, and its biosynthesis mainly occurs through the salvage pathway using the nicotinamide phosphoribosyl transferase (NAMPT) enzyme. The main nicotinamide adenine dinucleotide (NAD) consumers, poly-ADP-ribose-polymerases and sirtuins enzymes, are heavily involved in DNA repair and chromatin remodeling. Since cancer cells shift their energy production pathway, NAD levels are significantly affected. NAD's roles in cell survival led to the use of NAD depletion in cancer therapies. NAMPT inhibition (alone or in combination with other cancer therapies, including endocrine therapy and chemotherapy) results in decreased cell viability and tumor burden for many cancer types. Many NAMPT inhibitors (NAMPTi) tested before were discontinued due to toxicity; however, a novel NAMPTi, KPT-9274, is a promising, low-toxicity option currently in clinical trials.


Assuntos
Neoplasias , Sirtuínas , Humanos , NAD/metabolismo , Citocinas/metabolismo , Neoplasias/tratamento farmacológico , Reparo do DNA , Sirtuínas/genética
3.
Life Sci ; 342: 122537, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38428569

RESUMO

Parkinson's disease (PD) is a progressive neurodegenerative condition that primarily affects motor function and is caused by a gradual decline of dopaminergic neurons in the brain's substantia pars compacta (Snpc) region. Multiple molecular pathways are involved in the pathogenesis, which results in impaired cellular functions and neuronal degeneration. However, the role of sirtuins, a type of NAD+-dependent deacetylase, in the pathogenesis of Parkinson's disease has recently been investigated. Sirtuins are essential for preserving cellular homeostasis because they control a number of biological processes, such as metabolism, apoptosis, and DNA repair. This review shed lights on the dysregulation of sirtuin activity in PD, highlighting the role that acetylation and deacetylation processes play in the development of the disease. Key regulators of protein acetylation, sirtuins have been found to be involved in the aberrant acetylation of vital substrates linked to PD pathology when their balance is out of balance. The hallmark characteristics of PD such as neuroinflammation, oxidative stress, and mitochondrial dysfunction have all been linked to the dysregulation of sirtuin expression and activity. Furthermore, we have also explored how the modulators of sirtuins can be a promising therapeutic intervention in the treatment of PD.


Assuntos
Doença de Parkinson , Sirtuínas , Humanos , Doença de Parkinson/tratamento farmacológico , Sirtuínas/metabolismo , Acetilação , Processamento de Proteína Pós-Traducional , Neurônios Dopaminérgicos/metabolismo
4.
Cell Mol Biol (Noisy-le-grand) ; 70(2): 178-182, 2024 Feb 29.
Artigo em Inglês | MEDLINE | ID: mdl-38430021

RESUMO

This study aimed to investigate the role of Sirt6 and inflammatory cytokines in blood samples of patients with ACS. This is a retrospective randomized controlled clinical trial, a total of 30 patients from our hospital are included and divided into following two groups: control group and experimental group, and experimental group consists of 15 patients with ACS and control group consists of 15 patients with non-acute coronary syndrome. Sirt6 protein is detected by western blotting and Sirt6 mRNA is detected by real-time PCR, then inflammatory cytokines such as IL-1ß, IL-18, TnI, and CK-MB are measured by ELISA and cytokines NT-proBNP are monitored by immunofluorescence. Our outcomes show that Sirt6 protein and Sirt6 mRNA in experimental group are remarkably lower than those in control group, and IL-1ß, IL-18, TnI, CK-MB, and NT-proBNP in the experimental group are remarkably higher than those in control group. We can conclude that Sirt6 can prevent or inhibit the development of ACS and IL-1ß, IL-18, TnI, CK-MB, and NT-proBNP can accelerate the development of ACS.


Assuntos
Síndrome Coronariana Aguda , Sirtuínas , Humanos , Biomarcadores , Citocinas , Interleucina-18/genética , Estudos Retrospectivos , RNA Mensageiro , Sirtuínas/sangue , Sirtuínas/metabolismo
5.
Molecules ; 29(5)2024 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-38474697

RESUMO

Sirtuins are NAD+-dependent protein deacylases and key metabolic regulators, coupling the cellular energy state with selective lysine deacylation to regulate many downstream cellular processes. Humans encode seven sirtuin isoforms (Sirt1-7) with diverse subcellular localization and deacylase targets. Sirtuins are considered protective anti-aging proteins since increased sirtuin activity is canonically associated with lifespan extension and decreased activity with developing aging-related diseases. However, sirtuins can also assume detrimental cellular roles where increased activity contributes to pathophysiology. Modulation of sirtuin activity by activators and inhibitors thus holds substantial potential for defining the cellular roles of sirtuins in health and disease and developing therapeutics. Instead of being comprehensive, this review discusses the well-characterized sirtuin activators and inhibitors available to date, particularly those with demonstrated selectivity, potency, and cellular activity. This review also provides recommendations regarding the best-in-class sirtuin activators and inhibitors for practical research as sirtuin modulator discovery and refinement evolve.


Assuntos
Sirtuínas , Humanos , Sirtuínas/metabolismo , Sirtuína 1 , Isoformas de Proteínas/metabolismo , Lisina
6.
Cell Death Dis ; 15(3): 216, 2024 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-38485947

RESUMO

Despite progressive improvements in the survival rate of pediatric B-cell lineage acute lymphoblastic leukemia (B-ALL), chemoresistance-induced disease progression and recurrence still occur with poor prognosis, thus highlighting the urgent need to eradicate drug resistance in B-ALL. The 6-mercaptopurine (6-MP) is the backbone of ALL combination chemotherapy, and resistance to it is crucially related to relapse. The present study couples chemoresistance in pediatric B-ALL with histidine metabolism deficiency. Evidence was provided that histidine supplementation significantly shifts the 6-MP dose-response in 6-MP-resistant B-ALL. It is revealed that increased tetrahydrofolate consumption via histidine catabolism partially explains the re-sensitization ability of histidine. More importantly, this work provides fresh insights into that desuccinylation mediated by SIRT5 is an indispensable and synergistic requirement for histidine combination therapy against 6-MP resistance, which is undisclosed previously and demonstrates a rational strategy to ameliorate chemoresistance and protect pediatric patients with B-ALL from disease progression or relapse.


Assuntos
Linfoma de Burkitt , Leucemia-Linfoma Linfoblástico de Células Precursoras B , Leucemia-Linfoma Linfoblástico de Células Precursoras , Sirtuínas , Humanos , Criança , Mercaptopurina/farmacologia , Mercaptopurina/uso terapêutico , Histidina/uso terapêutico , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Leucemia-Linfoma Linfoblástico de Células Precursoras B/tratamento farmacológico , Linfoma de Burkitt/tratamento farmacológico , Recidiva , Progressão da Doença
7.
Nan Fang Yi Ke Da Xue Xue Bao ; 44(2): 244-251, 2024 Feb 20.
Artigo em Chinês | MEDLINE | ID: mdl-38501409

RESUMO

OBJECTIVE: To investigate the protective effect of total saponins of Panax japonicus (TSPJ) against CCl4-induced acute liver injury (ALI) in rats and explore the underlying pharmacological mechanisms. METHODS: Male SD rat models of CCl4-induced ALI were given intraperitoneal injections of distilled water, 100 mg/kg biphenyl bisabololol, or 50, 100, and 200 mg/kg TSPJ during modeling (n=8). Liver functions (AST, ALT, TBil and ALP) of the rats were assessed and liver pathologies were observed with HE staining. Immunohistochemistry was used to detect the expressions of PI3K/Akt/NF-κB signaling pathway molecules in liver tissue; ELISA was used to determine the levels of T-SOD, GSH-Px, and MDA. Western blotting was performed to detect the expression levels of PI3K-Akt and SIRT6-NF-κB pathways in the liver tissue. RESULTS: Network pharmacological analysis indicated that the key pathways including PI3K/Akt mediated the therapeutic effect of TSPJ on ALI. In the rat models of ALI, treatments with biphenyl bisabololol and TSPJ significantly ameliorated CCl4-induced increase of serum levels AST, ALT, ALP, TBil and MDA and decrease of T-SOD and GSH-Px levels (all P < 0.01). The rat models of ALI showed significantly increased expression of p-NF-κB (P < 0.01), decreased expressions of PI3K, p-Akt and SIRT6 proteins, and elevated expression levels of p-NF-κB, TNF-α and IL-6 proteins in the liver, which were all significantly improved in the treatment groups (P < 0.05 or 0.01). CONCLUSION: TSPJ can effectively alleviate CCl4-induced ALI in rats by suppressing inflammatory responses and oxidative stress in the liver via regulating the PI3K/Akt and SIRT6/NF-κB pathways.


Assuntos
Compostos de Bifenilo , Panax , Saponinas , Sirtuínas , Ratos , Masculino , Animais , NF-kappa B/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Saponinas/farmacologia , Saponinas/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Panax/metabolismo , Ratos Sprague-Dawley , Transdução de Sinais , Fígado/metabolismo , Sirtuínas/metabolismo , Sirtuínas/farmacologia , Superóxido Dismutase/metabolismo
8.
Life Sci Alliance ; 7(6)2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38499327

RESUMO

Cellular responses leading to development, proliferation, and differentiation depend on RAF/MEK/ERK signaling, which integrates and amplifies signals from various stimuli for downstream cellular responses. C-RAF activation has been reported in many types of tumor cell proliferation and developmental disorders, necessitating the discovery of potential C-RAF protein regulators. Here, we identify a novel and specific protein interaction between C-RAF among the RAF kinase paralogs, and SIRT4 among the mitochondrial sirtuin family members SIRT3, SIRT4, and SIRT5. Structurally, C-RAF binds to SIRT4 through the N-terminal cysteine-rich domain, whereas SIRT4 predominantly requires the C-terminus for full interaction with C-RAF. Interestingly, SIRT4 specifically interacts with C-RAF in a pre-signaling inactive (serine 259-phosphorylated) state. Consistent with this finding, the expression of SIRT4 in HEK293 cells results in an up-regulation of pS259-C-RAF levels and a concomitant reduction in MAPK signaling as evidenced by strongly decreased phospho-ERK signals. Thus, we propose an additional extra-mitochondrial function of SIRT4 as a cytosolic tumor suppressor of C-RAF-MAPK signaling, besides its metabolic tumor suppressor role of glutamate dehydrogenase and glutamate levels in mitochondria.


Assuntos
Sirtuínas , Humanos , Células HEK293 , Sirtuínas/genética , Sirtuínas/metabolismo , Transdução de Sinais , Mitocôndrias/metabolismo , Quinases raf/genética , Quinases raf/metabolismo , Proteínas Mitocondriais/genética , Proteínas Mitocondriais/metabolismo
9.
J Agric Food Chem ; 72(12): 6360-6371, 2024 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-38489847

RESUMO

Nonalcoholic fatty liver disease (NAFLD) represents the most prevalent type of chronic liver disease, spanning from simple steatosis to nonalcoholic steatohepatitis (NASH). Corn oligopeptide (CP) is a functional peptide known for its diverse pharmacological effects on metabolism. In this study, we evaluated the protective activity of CP against fatty liver disease. Oral administration of CP significantly reduced body weight gain by 2.95%, serum cholesterol by 22.54%, and liver injury, as evidenced by a reduction of 32.19% in serum aspartate aminotransferase (AST) and 49.10% in alanine aminotransferase (ALT) levels in mice subjected to a high-fat diet (HFD). In a streptozotocin/HFD-induced NASH mouse model, CP attenuated body weight gain by 5.11%, liver injury (with a 34.15% decrease in AST and 11.43% decrease in ALT), and, to some extent, liver inflammation and fibrosis. Proteomic analysis revealed the modulation of oxidative phosphorylation and sirtuin (SIRT) signaling pathways by CP. Remarkably, CP selectively inhibited the hepatic expression of mitochondrial SIRT3 and SIRT5 in both HFD and NASH models. In summary, CP demonstrates a preventive effect against metabolic-stress-induced NAFLD progression by modulating oxidative stress and the SIRT signaling pathway, suggesting the potential of CP as a therapeutic agent for the treatment of NAFLD and advanced-stage NASH.


Assuntos
Hepatopatia Gordurosa não Alcoólica , Sirtuínas , Camundongos , Animais , Hepatopatia Gordurosa não Alcoólica/metabolismo , Zea mays/metabolismo , Proteômica , Fígado/metabolismo , Transdução de Sinais , Aumento de Peso , Dieta Hiperlipídica , Oligopeptídeos/metabolismo , Sirtuínas/metabolismo , Camundongos Endogâmicos C57BL
10.
Biochem Biophys Res Commun ; 706: 149757, 2024 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-38490050

RESUMO

Cardiovascular disease is a main cause of mortality in the world and the highest incidence of all diseases. However, the mechanism of the pathogenesis of cardiovascular disease is still unclear, and we need to continue to explore its mechanism of action. The occurrence and development of cardiovascular disease is significantly associated with genetic abnormalities, and gene expression is affected by transcriptional regulation. In this complex process, the protein-protein interaction promotes the RNA polymerase II to the initiation site. And in this process of transcriptional regulation, transcriptional cofactors are responsible for passing cues from enhancers to promoters and promoting the binding of RNA polymerases to promoters, so transcription cofactors playing a key role in gene expression regulation. There is growing evidence that transcriptional cofactors play a critical role in cardiovascular disease. Transcriptional cofactors can promote or inhibit transcription by affecting the function of transcription factors. It can affect the initiation and elongation process of transcription by forming complexes with transcription factors, which are important for the stabilization of DNA rings. It can also act as a protein that interacts with other proteins to affect the expression of other genes. Therefore, the aim of this overview is to summarize the effect of some transcriptional cofactors such as BRD4, EP300, MED1, EZH2, YAP, SIRT6 in cardiovascular disease and to provide a promising therapeutic strategy for the treatment of cardiovascular disease.


Assuntos
Doenças Cardiovasculares , Sirtuínas , Humanos , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Transcrição Gênica , Proteínas Nucleares/metabolismo , Doenças Cardiovasculares/genética , Regulação da Expressão Gênica , RNA Polimerase II/metabolismo , Proteínas que Contêm Bromodomínio , Proteínas de Ciclo Celular/metabolismo , Sirtuínas/metabolismo
11.
Nat Commun ; 15(1): 2692, 2024 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-38538592

RESUMO

The Silent Information Regulator 2 (SIR2) protein is widely implicated in antiviral response by depleting the cellular metabolite NAD+. The defense-associated sirtuin 2 (DSR2) effector, a SIR2 domain-containing protein, protects bacteria from phage infection by depleting NAD+, while an anti-DSR2 protein (DSR anti-defense 1, DSAD1) is employed by some phages to evade this host defense. The NADase activity of DSR2 is unleashed by recognizing the phage tail tube protein (TTP). However, the activation and inhibition mechanisms of DSR2 are unclear. Here, we determine the cryo-EM structures of DSR2 in multiple states. DSR2 is arranged as a dimer of dimers, which is facilitated by the tetramerization of SIR2 domains. Moreover, the DSR2 assembly is essential for activating the NADase function. The activator TTP binding would trigger the opening of the catalytic pocket and the decoupling of the N-terminal SIR2 domain from the C-terminal domain (CTD) of DSR2. Importantly, we further show that the activation mechanism is conserved among other SIR2-dependent anti-phage systems. Interestingly, the inhibitor DSAD1 mimics TTP to trap DSR2, thus occupying the TTP-binding pocket and inhibiting the NADase function. Together, our results provide molecular insights into the regulatory mechanism of SIR2-dependent NAD+ depletion in antiviral immunity.


Assuntos
Sirtuínas , Sirtuínas/metabolismo , Proteínas Reguladoras de Informação Silenciosa de Saccharomyces cerevisiae/metabolismo , NAD/metabolismo , NAD+ Nucleosidase/metabolismo , Sirtuína 2/metabolismo , Ligação Proteica , Bactérias/metabolismo , Proteínas de Bactérias/metabolismo
12.
Pharmacol Res ; 202: 107141, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38490314

RESUMO

Osteoarthritis (OA) is a degenerative disease characterised by articular cartilage destruction, and its complex aetiology contributes to suboptimal clinical treatment outcomes. A close association exists between glucose metabolism dysregulation and OA pathogenesis. Owing to the unique environment of low oxygen and glucose concentrations, chondrocytes rely heavily on their glycolytic capacity, exhibiting distinct spatiotemporal differences. However, under pathological stimulation, chondrocytes undergo excessive glycolytic activity while mitochondrial respiration and other branches of glucose metabolism are compromised. This metabolic change induces cartilage degeneration by reprogramming the inflammatory responses. Sirtuins, a highly conserved family of nicotinamide adenine dinucleotide (NAD+)-dependent deacetylases, regulate glucose metabolism in response to energy fluctuations in different cellular compartments,alleviating metabolic stress. SIRT1, the most extensively studied sirtuin, participates in maintaining glucose homeostasis in almost all key metabolic tissues. While actively contributing to the OA progression and displaying diverse biological effects in cartilage protection, SIRT1's role in regulating glucose metabolism in chondrocytes has not received sufficient attention. This review focuses on discussing the beneficial role of SIRT1 in OA progression from a metabolic regulation perspective based on elucidating the primary characteristics of chondrocyte glucose metabolism. We also summarise the potential mechanisms and therapeutic strategies targeting SIRT1 in chondrocytes to guide clinical practice and explore novel therapeutic directions.


Assuntos
Glucose , Osteoartrite , Sirtuína 1 , Animais , Humanos , Cartilagem Articular/patologia , Glucose/metabolismo , Osteoartrite/metabolismo , Sirtuína 1/metabolismo , Sirtuínas/metabolismo
13.
BMC Cancer ; 24(1): 386, 2024 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-38532359

RESUMO

Chordoma is a relatively rare and locally aggressive malignant tumor. Sirtuin (SIRT)5 plays pivotal roles in various tumors, but the role of SIRT5 in chordoma has not been found. This study was performed to investigate the regulatory effects of SIRT5 on cell proliferation, migration, and invasion and the underlying mechanism in chordoma. A xenograft tumor mouse model was established to assess tumor growth. Reverse transcription-quantitative polymerase chain reaction was used to analyze the mRNA levels of SIRT5 and c-myc. The effects of SIRT5 and c-myc on cell proliferation, migration, and invasion of chordoma cells were detected by cell counting kit-8, colony formation, and Transwell assays. The interaction between SIRT5 and c-myc was evaluated by co-immunoprecipitation (IP) assay. The succinylation of c-myc was analyzed by IP and Western blot. The results showed that SIRT5 expression was upregulated in chordoma tissues and cells. SIRT5 interacted with c-myc to inhibit the succinylation of c-myc at K369 site in human embryonic kidney (HEK)-293T cells. Silencing of SIRT5 suppressed the cell proliferation, migration, and invasion of chordoma cells, while the results were reversed after c-myc overexpression. Moreover, silencing SIRT5 suppressed tumor growth in mice. These findings suggested that SIRT5 promoted the malignant advancement of chordoma by regulating the desuccinylation of c-myc.


Assuntos
Cordoma , Sirtuínas , Animais , Humanos , Camundongos , Linhagem Celular Tumoral , Proliferação de Células , Sirtuínas/genética , Sirtuínas/metabolismo
14.
Mol Med ; 30(1): 44, 2024 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-38553713

RESUMO

BACKGROUND: Intervertebral disc degeneration (IVDD) is one of the etiologic factors of degenerative spinal diseases, which can lead to a variety of pathological spinal conditions such as disc herniation, spinal stenosis, and scoliosis. IVDD is a leading cause of lower back pain, the prevalence of which increases with age. Recently, Sirtuins/SIRTs and their related activators have received attention for their activity in the treatment of IVDD. In this paper, a comprehensive systematic review of the literature on the role of SIRTs and their activators on IVDD in recent years is presented. The molecular pathways involved in the regulation of IVDD by SIRTs are summarized, and the effects of SIRTs on senescence, inflammatory responses, oxidative stress, and mitochondrial dysfunction in myeloid cells are discussed with a view to suggesting possible solutions for the current treatment of IVDD. PURPOSE: This paper focuses on the molecular mechanisms by which SIRTs and their activators act on IVDD. METHODS: A literature search was conducted in Pubmed and Web of Science databases over a 13-year period from 2011 to 2024 for the terms "SIRT", "Sirtuin", "IVDD", "IDD", "IVD", "NP", "Intervertebral disc degeneration", "Intervertebral disc" and "Nucleus pulposus". RESULTS: According to the results, SIRTs and a large number of activators showed positive effects against IVDD.SIRTs modulate autophagy, myeloid apoptosis, oxidative stress and extracellular matrix degradation. In addition, they attenuate inflammatory factor-induced disc damage and maintain homeostasis during disc degeneration. Several clinical studies have reported the protective effects of some SIRTs activators (e.g., resveratrol, melatonin, honokiol, and 1,4-dihydropyridine) against IVDD. CONCLUSION: The fact that SIRTs and their activators play a hundred different roles in IVDD helps to better understand their potential to develop further treatments for IVDD. NOVELTY: This review summarizes current information on the mechanisms of action of SIRTs in IVDD and the challenges and limitations of translating their basic research into therapy.


Assuntos
Degeneração do Disco Intervertebral , Deslocamento do Disco Intervertebral , Disco Intervertebral , Núcleo Pulposo , Sirtuínas , Humanos , Degeneração do Disco Intervertebral/metabolismo , Deslocamento do Disco Intervertebral/metabolismo , Núcleo Pulposo/metabolismo , Estresse Oxidativo , Sirtuínas/metabolismo , Disco Intervertebral/metabolismo , Disco Intervertebral/patologia
15.
Nat Commun ; 15(1): 2797, 2024 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-38555355

RESUMO

Silent information regulator 2 (Sir2) proteins typically catalyze NAD+-dependent protein deacetylation. The recently identified bacterial Sir2 domain-containing protein, defense-associated sirtuin 2 (DSR2), recognizes the phage tail tube and depletes NAD+ to abort phage propagation, which is counteracted by the phage-encoded DSR anti-defense 1 (DSAD1), but their molecular mechanisms remain unclear. Here, we determine cryo-EM structures of inactive DSR2 in its apo form, DSR2-DSAD1 and DSR2-DSAD1-NAD+, as well as active DSR2-tube and DSR2-tube-NAD+ complexes. DSR2 forms a tetramer with its C-terminal sensor domains (CTDs) in two distinct conformations: CTDclosed or CTDopen. Monomeric, rather than oligomeric, tail tube proteins preferentially bind to CTDclosed and activate Sir2 for NAD+ hydrolysis. DSAD1 binding to CTDopen allosterically inhibits tube binding and tube-mediated DSR2 activation. Our findings provide mechanistic insight into DSR2 assembly, tube-mediated DSR2 activation, and DSAD1-mediated inhibition and NAD+ substrate catalysis in bacterial DSR2 anti-phage defense systems.


Assuntos
Sirtuínas , Sirtuínas/metabolismo , NAD/metabolismo , Proteínas Reguladoras de Informação Silenciosa de Saccharomyces cerevisiae/metabolismo , Sirtuína 2 , Hidrólise
16.
Artigo em Inglês | MEDLINE | ID: mdl-38544929

RESUMO

Background: The incidence of chronic obstructive pulmonary disease (COPD) is increasing year by year. Kruppel-like factor 6 (KLF6) plays an important role in inflammatory diseases. However, the regulatory role of KLF6 in COPD has not been reported so far. Methods: The viability of human bronchial epithelial cells BEAS-2B induced by cigarette smoke extract (CSE) was detected by CCK-8 assay. The protein expression of KLF6 and sirtuin 4 (SIRT4) was appraised with Western blot. RT-qPCR and Western blot were applied to examine the transfection efficacy of sh-KLF6 and Oe-KLF6. Cell apoptosis was detected using flow cytometry. The levels of inflammatory factors IL-6, TNF-α and IL-1ß were assessed with ELISA assay. DCFH-DA staining was employed for the detection of ROS activity and the levels of oxidative stress markers SOD, CAT and MDA were estimated with corresponding assay kits. The mitochondrial membrane potential (MMP), adenosine triphosphate (ATP) content and Complex I activity were evaluated with JC-1 staining, ATP colorimetric/fluorometric assay kit and Complex I enzyme activity microplate assay kit. With the application of mitochondrial permeability transition pore detection kit, mPTP opening was measured. Luciferase report assay was employed to evaluate the activity of SIRT4 promoter and chromatin immunoprecipitation (ChIP) to verify the binding ability of KLF6 and SIRT4 promoter. Results: KLF6 expression was significantly elevated in CSE-induced cells. KLF6 was confirmed to suppress SIRT4 transcription. Interference with KLF6 expression significantly inhibited cell viability damage, cell apoptosis, inflammatory response, oxidative stress and mitochondrial dysfunction in CSE-induced BEAS-2B cells, which were all reversed by SIRT4 overexpression. Conclusion: Silencing KLF6 alleviated CSE-induced mitochondrial dysfunction in bronchial epithelial cells by SIRT4 upregulation.


Assuntos
Fumar Cigarros , Doenças Mitocondriais , Doença Pulmonar Obstrutiva Crônica , Sirtuínas , Humanos , Doença Pulmonar Obstrutiva Crônica/metabolismo , Regulação para Cima , Linhagem Celular , Fator 6 Semelhante a Kruppel/genética , Fator 6 Semelhante a Kruppel/metabolismo , Fumar Cigarros/efeitos adversos , Apoptose , Células Epiteliais/metabolismo , Trifosfato de Adenosina/efeitos adversos , Trifosfato de Adenosina/metabolismo , Doenças Mitocondriais/metabolismo , Proteínas Mitocondriais/efeitos adversos , Proteínas Mitocondriais/metabolismo , Sirtuínas/genética
17.
Nat Metab ; 6(3): 550-566, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38448615

RESUMO

The post-translational modification lysine succinylation is implicated in the regulation of various metabolic pathways. However, its biological relevance remains uncertain due to methodological difficulties in determining high-impact succinylation sites. Here, using stable isotope labelling and data-independent acquisition mass spectrometry, we quantified lysine succinylation stoichiometries in mouse livers. Despite the low overall stoichiometry of lysine succinylation, several high-stoichiometry sites were identified, especially upon deletion of the desuccinylase SIRT5. In particular, multiple high-stoichiometry lysine sites identified in argininosuccinate synthase (ASS1), a key enzyme in the urea cycle, are regulated by SIRT5. Mutation of the high-stoichiometry lysine in ASS1 to succinyl-mimetic glutamic acid significantly decreased its enzymatic activity. Metabolomics profiling confirms that SIRT5 deficiency decreases urea cycle activity in liver. Importantly, SIRT5 deficiency compromises ammonia tolerance, which can be reversed by the overexpression of wild-type, but not succinyl-mimetic, ASS1. Therefore, lysine succinylation is functionally important in ammonia metabolism.


Assuntos
Lisina , Sirtuínas , Camundongos , Animais , Lisina/química , Lisina/metabolismo , Amônia , Sirtuínas/metabolismo , Camundongos Knockout , Ureia
18.
Ecotoxicol Environ Saf ; 274: 116191, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38460408

RESUMO

The reproduction toxicity of pubertal exposure to Microcystin-LR (MC-LR) and the underlying mechanism needs to be further investigated. In the current study, pubertal male ICR mice were intraperitoneally injected with 2 µg/kg MC-LR for four weeks. Pubertal exposure to MC-LR decreased epididymal sperm concentration and blocked spermatogonia proliferation. In-vitro studies found MC-LR inhibited cell proliferation of GC-1 cells and arrested cell cycle in G2/M phase. Mechanistically, MC-LR exposure evoked excessive reactive oxygen species (ROS) and induced DNA double-strand break in GC-1 cells. Besides, MC-LR inhibited DNA repair by reducing PolyADP-ribosylation (PARylation) activity of PARP1. Further study found MC-LR caused proteasomal degradation of SIRT6, a monoADP-ribosylation enzyme which is essential for PARP1 PARylation activity, due to destruction of SIRT6-USP10 interaction. Additionally, MG132 pretreatment alleviated MC-LR-induced SIRT6 degradation and promoted DNA repair, leading to the restoration of cell proliferation inhibition. Correspondingly, N-Acetylcysteine (NAC) pre-treatment mitigated the disturbed SIRT6-USP10 interaction and SIRT6 degradation, causing recovered DNA repair and subsequently restoration of cell proliferation inhibition in MC-LR treated GC-1 cells. Together, pubertal exposure to MC-LR induced spermatogonia cell cycle arrest and sperm count reduction by oxidative DNA damage and simultaneous SIRT6-mediated DNA repair failing. This study reports the effect of pubertal exposure to MC-LR on spermatogenesis and complex mechanism how MC-LR induces spermatogonia cell proliferation inhibition.


Assuntos
Toxinas Marinhas , Microcistinas , Sirtuínas , Espermatogônias , Animais , Masculino , Camundongos , Apoptose , Proliferação de Células , Quebras de DNA de Cadeia Dupla/efeitos dos fármacos , Reparo do DNA , Toxinas Marinhas/metabolismo , Toxinas Marinhas/toxicidade , Camundongos Endogâmicos ICR , Microcistinas/metabolismo , Microcistinas/toxicidade , Sêmen , Sirtuínas/efeitos dos fármacos , Sirtuínas/metabolismo , Espermatogônias/efeitos dos fármacos , Espermatogônias/metabolismo
19.
Nanoscale ; 16(13): 6585-6595, 2024 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-38465774

RESUMO

Nicotinamide adenine dinucleotide (NADH) and its phosphorylated form, NADPH, are essential cofactors that play critical roles in cell functions, influencing antioxidation, reductive biosynthesis, and cellular pathways involved in tumor cell apoptosis and tumorigenesis. However, the use of nanomaterials to consume NAD(P)H and thus bring an impact on signaling pathways in cancer treatment remains understudied. In this study, we employed a salt template method to synthesize a carbon-coated-cobalt composite (C@Co) nanozyme, which exhibited excellent NAD(P)H oxidase (NOX)-like activity and mimicked the reaction mechanism of natural NOX. The C@Co nanozyme efficiently consumed NAD(P)H within cancer cells, leading to increased production of reactive oxygen species (ROS) and a reduction in mitochondrial membrane potential. Meanwhile, the generation of the biologically active cofactor NAD(P)+ promoted the expression of the deacetylase SIRT7, which in turn inhibited the serine/threonine kinase AKT signaling pathway, ultimately promoting apoptosis. This work sheds light on the influence of nanozymes with NOX-like activity on cellular signaling pathways in tumor therapy and demonstrates their promising antitumor effects in a tumor xenograft mouse model. These findings contribute to a better understanding of NAD(P)H manipulation in cancer treatment and suggest the potential of nanozymes as a therapeutic strategy for cancer therapy.


Assuntos
NADPH Oxidases , Nanoestruturas , Sirtuínas , Animais , Humanos , Camundongos , Glicogênio Sintase Quinase 3 beta/efeitos dos fármacos , Glicogênio Sintase Quinase 3 beta/metabolismo , NAD/metabolismo , NADPH Oxidases/farmacologia , NADPH Oxidases/uso terapêutico , Proteínas Proto-Oncogênicas c-akt/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-akt/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Sirtuínas/efeitos dos fármacos , Sirtuínas/metabolismo , Nanoestruturas/uso terapêutico , Neoplasias/tratamento farmacológico , Neoplasias/terapia
20.
Ecotoxicol Environ Saf ; 275: 116253, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38537475

RESUMO

Pregnancy is a sensitive window period for bisphenol A (BPA) exposure. BPA can pass through the placenta and cause reproductive damage in offspring female mice. Even BPA that is not metabolized during lactation can be passed through milk. Cuscuta chinensis flavonoids (CCFs) can alleviate reproductive damage caused by BPA, but the mechanism of action is unclear. To investigate the potential mitigating impact of CCFs on ovarian damage resulting from BPA exposure during pregnancy, we administered BPA and CCFs to pregnant mice during the gestational period spanning from 0.5 to 17.5 days. Aseptic collection of serum and ovaries from female mice was conducted on postnatal day 21 (PND21). Serum hormone levels and tissue receptor levels were quantified utilizing ELISA and PCR, while ovaries underwent sequencing and analysis through transcriptomics and metabolomics techniques. Additionally, the assessment of ovarian oxidative stress levels was carried out as part of the comprehensive analysis. The results showed that CCFs administration mitigated the adverse effects induced by BPA exposure on ovarian index, hormone levels, receptor expression, and mRNA expression levels in female offspring mice. The joint analysis of transcriptome and metabolome revealed 48 enriched pathways in positive ion mode and 44 enriched pathways in negative ion mode. Among them, the central carbon metabolism pathway is significantly regulated by BPA and CCFs. The screened sequencing results were verified through qPCR and biochemical kits. In this study, CCFs may participate in the central carbon metabolism pathway by reducing the expression of Kit proto-oncogene (Kit), hexokinase 1 gene (Hk1) and pyruvate kinase M (Pkm) mRNA and increasing the expression of h-ras proto-oncogene (Hras), sirtuin 3 (Sirt3), sirtuin 6 (Sirt6) and TP53 induced glycolysis regulatory phosphatase gene (Tigar) mRNA, thereby resisting the effects of BPA on the body. At the same time, the metabolic levels of D-Fructose 1,6-bisphosphate and L-Asparagine tend to be stable. Moreover, CCFs demonstrated a capacity to diminish the BPA-induced escalation in reactive oxygen species (ROS) and malondialdehyde (MDA). Simultaneously, it exhibited the ability to elevate levels of glutathione (GSH) and catalase (CAT), thereby effectively preventing peroxidation. In summary, CCFs alleviate BPA-induced ovarian damage in offspring female mice by regulating the central carbon metabolism pathway. This study will improve the information on BPA reproductive damage antagonist drugs and provide a theoretical basis for protecting animal reproductive health.


Assuntos
Cuscuta , Disruptores Endócrinos , Fenóis , Sirtuínas , Gravidez , Camundongos , Animais , Feminino , Ovário , Cuscuta/genética , Flavonoides/farmacologia , Compostos Benzidrílicos/toxicidade , Hormônios , RNA Mensageiro , Disruptores Endócrinos/farmacologia
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