RESUMO
As cellular senescence, reactive oxygen species (ROS) accumulate excessively, causing cellular damage. Flavonoids derived from natural products are known for their antioxidant effects and their ability to delay cellular senescence. Previous studies have attempted to mitigate cellular senescence using flavonoids from natural sources. However, the detailed mechanisms and regulatory targets of some flavonoids exhibiting antioxidant effects have not been fully elucidated. Therefore, we screened a library of flavonoids for antioxidant properties. Isoschaftoside, a glycosidic flavonoid, significantly reduced ROS levels in senescent cells. It was found that mitochondrial function was restored, and dependence on glycolysis was reduced in senescent cells treated with isoschaftoside. Additionally, we identified that isoschaftoside suppresses ROS by reducing the expression of RAC2 and LINC00294 in senescent cells. Taken together, this study establishes a novel mechanism for ROS inhibition and the regulation of cellular senescence by isoschaftoside. Our findings contribute important insights to antioxidant and anti-senescence research.
Assuntos
Antioxidantes , Senescência Celular , Proteína RAC2 de Ligação ao GTP , Espécies Reativas de Oxigênio , Proteínas rac de Ligação ao GTP , Senescência Celular/efeitos dos fármacos , Humanos , Espécies Reativas de Oxigênio/metabolismo , Proteínas rac de Ligação ao GTP/metabolismo , Proteínas rac de Ligação ao GTP/genética , Antioxidantes/farmacologia , Antioxidantes/química , Mitocôndrias/metabolismo , Mitocôndrias/efeitos dos fármacos , Glicosídeos/farmacologia , Glicosídeos/química , Flavonoides/farmacologia , Flavonoides/química , Linhagem CelularRESUMO
The establishment of cell lines with a high protein production is the most crucial objective in the field of biopharmaceuticals. To this end, efforts have been made to increase transgene expression through promoter improvement, but the efficiency or stability of protein production was insufficient for use in commercial production. Here, we developed a novel strategy to increase the efficiency and stability of protein production by hybridizing a promoter that exhibits higher expression levels at the transient level with a promoter that exhibits higher stability at the stable level. Expression levels of transgenes by each promoter were measured at transient and stable levels for five single promoters: Rous sarcoma virus (RSV), cytomegalovirus (CMV), human phosphoglycerate kinase (hPGK), simian virus 40 (SV40), and zebrafish ubiquitin B (Ubb). The hPGK promoter enabled high-yield transgene expression at transient levels and the SV40 promoter enabled sustained expression at stable levels. Therefore, hPGK and SV40 promoters were selected as candidates for establishing hybrid promoters and two hybrid promoters were constructed; one hybrid promoter in which the SV40 promoter is added before the hPGK promoter (a.k.a. SKYI) and the other hybrid promoter in which the SV40 promoter is added after the hPGK promoter (a.k.a. SKYII). Of the two hybrid promoters, the hybrid promoter SKYII promoted high-yield transgene expression at both transient and stable levels compared to single hPGK and SV40. Together, our findings open new doors in the field of biopharmaceuticals by presenting a novel promoter platform that can be used for high-yield and sustained protein production.
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Vetores Genéticos , Peixe-Zebra , Animais , Humanos , Regiões Promotoras Genéticas , Transgenes , Linhagem Celular , Vírus 40 dos Símios/genéticaRESUMO
Adiponectin, an adipose tissue-derived hormone, plays integral roles in lipid and glucose metabolism in peripheral tissues, such as the skeletal muscle, adipose tissue, and liver. Moreover, it has also been shown to have an impact on metabolic processes in the central nervous system. Astrocytes comprise the most abundant cell type in the central nervous system and actively participate in metabolic processes between blood vessels and neurons. However, the ability of adiponectin to control nutrient metabolism in astrocytes has not yet been fully elucidated. In this study, we investigated the effects of adiponectin on multiple metabolic processes in hypothalamic astrocytes. Adiponectin enhanced glucose uptake, glycolytic processes and fatty acid oxidation in cultured primary hypothalamic astrocytes. In line with these findings, we also found that adiponectin treatment effectively enhanced synthesis and release of monocarboxylates. Overall, these data suggested that adiponectin triggers catabolic processes in astrocytes, thereby enhancing nutrient availability in the hypothalamus.
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Adiponectina/metabolismo , Astrócitos/metabolismo , Glucose/metabolismo , Hipotálamo/metabolismo , Nutrientes/metabolismo , Adiponectina/genética , Animais , Astrócitos/citologia , Metabolismo Energético , Feminino , Glicólise , Hipotálamo/citologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , OxirreduçãoRESUMO
Senescence, defined as irreversible cell-cycle arrest, is the main driving force of aging and age-related diseases. Here, we performed high-throughput screening to identify compounds that alleviate senescence and identified the ataxia telangiectasia mutated (ATM) inhibitor KU-60019 as an effective agent. To elucidate the mechanism underlying ATM's role in senescence, we performed a yeast two-hybrid screen and found that ATM interacted with the vacuolar ATPase V1 subunits ATP6V1E1 and ATP6V1G1. Specifically, ATM decreased E-G dimerization through direct phosphorylation of ATP6V1G1. Attenuation of ATM activity restored the dimerization, thus consequently facilitating assembly of the V1 and V0 domains with concomitant reacidification of the lysosome. In turn, this reacidification induced the functional recovery of the lysosome/autophagy system and was coupled with mitochondrial functional recovery and metabolic reprogramming. Together, our data reveal a new mechanism through which senescence is controlled by the lysosomal-mitochondrial axis, whose function is modulated by the fine-tuning of ATM activity.
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Envelhecimento/efeitos dos fármacos , Sistemas de Liberação de Medicamentos , Morfolinas/farmacologia , Tioxantenos/farmacologia , Adenosina Trifosfatases/metabolismo , Animais , Proteínas Mutadas de Ataxia Telangiectasia/metabolismo , Núcleo Celular , Ativação Enzimática/efeitos dos fármacos , Citometria de Fluxo , Humanos , Concentração de Íons de Hidrogênio , Lisossomos/enzimologia , Lisossomos/metabolismo , Camundongos , Mitocôndrias/enzimologia , Mitocôndrias/metabolismo , Fosforilação , Inibidores de Proteínas Quinases/farmacologia , Espécies Reativas de OxigênioRESUMO
BACKGROUND: The IDF-11774, a novel clinical candidate for cancer therapy, targets HSP70 and inhibits mitochondrial respiration, resulting in the activation of AMPK and reduction in HIF-1α accumulation. METHODS: To identify genes that have synthetic lethality to IDF-11774, RNA interference screening was conducted, using pooled lentiviruses expressing a short hairpin RNA library. RESULTS: We identified ATP6V0C, encoding the V0 subunit C of lysosomal V-ATPase, knockdown of which induced a synergistic growth-inhibitory effect in HCT116 cells in the presence of IDF-11774. The synthetic lethality of IDF-11774 with ATP6V0C possibly correlates with IDF-11774-mediated autolysosome formation. Notably, the synergistic effect of IDF-11774 and the ATP6V0C inhibitor, bafilomycin A1, depended on the PIK3CA genetic status and Bcl-2 expression, which regulates autolysosome formation and apoptosis. Similarly, in an experiment using conditionally reprogramed cells derived from colorectal cancer patients, synergistic growth inhibition was observed in cells with low Bcl-2 expression. CONCLUSIONS: Bcl-2 is a biomarker for the synthetic lethal interaction of IDF-11774 with ATP6V0C, which is clinically applicable for the treatment of cancer patients with IDF-11774 or autophagy-inducing anti-cancer drugs.
Assuntos
Adamantano/análogos & derivados , Neoplasias Colorretais/enzimologia , Piperazinas/farmacologia , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , ATPases Vacuolares Próton-Translocadoras/antagonistas & inibidores , Adamantano/farmacologia , Animais , Apoptose/efeitos dos fármacos , Autofagia/efeitos dos fármacos , Linhagem Celular Tumoral , Classe I de Fosfatidilinositol 3-Quinases/genética , Neoplasias Colorretais/patologia , Feminino , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Macrolídeos/farmacologia , Camundongos , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
To precisely purify and study aged (senescent) cells, we have designed, fabricated, and demonstrated a novel diamond-structure (DS) microfluidic filter. Nonuniform flow velocities within the microfilter channel can compromise microfluidic filter performance, but with this new diamond structure, further optimized via simulation, we achieve a uniform microfilter flow field, improving the throughput of size-based separation of senescent cells, as obtained by 39-passaged human dermal fibroblasts. After separating these aged cells into two groups, consisting of large- and small-sized cells, we assessed senescence by measuring lipofuscin accumulation and ß-galactosidase activity. Our results reveal that even though these senescent cells had been equivalently passaged in culture, a high degree of size distribution and senescent phenotype heterogeneity was observed. In particular, the smaller-sized cells tended to express a younger phenotype while the larger aged cells demonstrated an older phenotype. We suggest that size-based separation of senescent cells, subtyped into small- and large-sized cohorts, offers an alternative method to purify such aged cells, thereby enabling more precise study of the mechanisms of aging, autophagy impairment, and rejuvenation.
Assuntos
Separação Celular , Senescência Celular , Técnicas Analíticas Microfluídicas , Separação Celular/instrumentação , Células Cultivadas , Criança , Fibroblastos/citologia , Humanos , Masculino , Técnicas Analíticas Microfluídicas/instrumentação , Tamanho da Partícula , Pele/citologia , Propriedades de SuperfícieRESUMO
Development of the pancreas and cerebellum require Pancreas-specific transcription factor-1a (Ptf1a), which encodes a subunit of the transcription factor complex PTF1. Ptf1a is required in succession for specification of the pancreas, proper allocation of pancreatic progenitors to endocrine and exocrine fates, and the production of digestive enzymes from the exocrine acini. In several neuronal structures, including the cerebellum, hindbrain, retina and spinal cord, Ptf1a is transiently expressed and promotes inhibitory neuron fates at the expense of excitatory fates. Transcription of Ptf1a in mouse is maintained in part by PTF1 acting on an upstream autoregulatory enhancer. However, the transcription factors and enhancers that initially activate Ptf1a expression in the pancreas and in certain structures of the nervous system have not yet been identified. Here we describe a zebrafish autoregulatory element, conserved among teleosts, with activity similar to that described in mouse. In addition, we performed a comprehensive survey of all non-coding sequences in a 67kb interval encompassing zebrafish ptf1a, and identified several neuronal enhancers, and an enhancer active in the ventral pancreas prior to activation of the autoregulatory enhancer. To test the requirement for autoregulatory control during pancreatic development, we restored ptf1a function through BAC transgenesis in ptf1a morphants, either with an intact BAC or one lacking the autoregulatory enhancer. We find that ptf1a autoregulation is required for development of the exocrine pancreas and full rescue of the ptf1a morphant phenotype. Similarly, we demonstrate that a ptf1a locus lacking the early enhancer region is also capable of rescue, but only supports formation of a hypoplastic exocrine pancreas. Through our dissection of the complex regulatory control of ptf1a, we identified separate cis-regulatory elements that underlie different aspects of its expression and function, and further demonstrated the requirement of maintained ptf1a expression for normal pancreatic morphogenesis. We also identified a novel enhancer that mediates initiation of ptf1a expression in the pancreas, through which the signals that specify the ventral pancreas are expected to exert their action.
Assuntos
Regulação da Expressão Gênica no Desenvolvimento , Pâncreas Exócrino/crescimento & desenvolvimento , Fatores de Transcrição/metabolismo , Proteínas de Peixe-Zebra/metabolismo , Peixe-Zebra/metabolismo , Animais , Sequência de Bases , Diferenciação Celular , Cromossomos Artificiais Bacterianos/metabolismo , Sequência Conservada , Embrião não Mamífero/metabolismo , Técnicas de Transferência de Genes , Loci Gênicos , Homeostase , Dados de Sequência Molecular , Pâncreas Exócrino/metabolismo , Fenótipo , Sequências Reguladoras de Ácido Nucleico , Homologia de Sequência do Ácido Nucleico , Fatores de Transcrição/genética , Peixe-Zebra/genética , Peixe-Zebra/crescimento & desenvolvimento , Proteínas de Peixe-Zebra/genéticaRESUMO
UNLABELLED: Patient-specific induced pluripotent stem cells (iPSCs) represent a potential source for developing novel drug and cell therapies. Although increasing numbers of disease-specific iPSCs have been generated, there has been limited progress in iPSC-based drug screening/discovery for liver diseases, and the low gene-targeting efficiency in human iPSCs warrants further improvement. Using iPSC lines from patients with alpha-1 antitrypsin (AAT) deficiency, for which there is currently no drug or gene therapy available, we established a platform to discover new drug candidates and correct disease-causing mutation with a high efficiency. A high-throughput format screening assay, based on our hepatic differentiation protocol, was implemented to facilitate automated quantification of cellular AAT accumulation using a 96-well immunofluorescence reader. To expedite the eventual application of lead compounds to patients, we conducted drug screening utilizing our established library of clinical compounds (the Johns Hopkins Drug Library) with extensive safety profiles. Through a blind large-scale drug screening, five clinical drugs were identified to reduce AAT accumulation in diverse patient iPSC-derived hepatocyte-like cells. In addition, using the recently developed transcription activator-like effector nuclease technology, we achieved high gene-targeting efficiency in AAT-deficiency patient iPSCs with 25%-33% of the clones demonstrating simultaneous targeting at both diseased alleles. The hepatocyte-like cells derived from the gene-corrected iPSCs were functional without the mutant AAT accumulation. This highly efficient and cost-effective targeting technology will broadly benefit both basic and translational applications. CONCLUSIONS: Our results demonstrated the feasibility of effective large-scale drug screening using an iPSC-based disease model and highly robust gene targeting in human iPSCs, both of which are critical for translating the iPSC technology into novel therapies for untreatable diseases.
Assuntos
Hepatócitos/efeitos dos fármacos , Hepatopatias/terapia , Células-Tronco Pluripotentes/efeitos dos fármacos , Reparo Gênico Alvo-Dirigido/métodos , Deficiência de alfa 1-Antitripsina/terapia , Diferenciação Celular , Células Cultivadas , Hepatócitos/citologia , Humanos , Hepatopatias/genéticaRESUMO
Oxidative stress caused by reactive oxygen species (ROS) is one of the major causes of senescence. Strategies to reduce ROS are known to be important factors in reversing senescence, but effective strategies have not been found. In this study, we screened substances commonly used as cosmetic additives to find substances with antioxidant effects. Polygonum cuspidatum (P. cuspidatum) extract significantly reduced ROS levels in senescent cells. A novel mechanism was discovered in which P. cuspidatum extract reduced ROS, a byproduct of inefficient oxidative phosphorylation (OXPHOS), by increasing OXPHOS efficiency. The reduction in ROS by P. cuspidatum extract restored senescence-associated phenotypes and enhanced skin protection. Then, we identified polydatin as the active ingredient of P. cuspidatum extract that exhibited antioxidant effects. Polydatin, which contains stilbenoid polyphenols that act as singlet oxygen scavengers through redox reactions, increased OXPHOS efficiency and subsequently restored senescence-associated phenotypes. In summary, our data confirmed the effects of P. cuspidatum extract on senescence rejuvenation and skin protection through ROS reduction. This novel finding may be used as a treatment in senescence rejuvenation in clinical and cosmetic fields.
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Heavy metals have serious negative effects on various aquatic organisms, and therefore rapid and accurate ecotoxicological assessments of heavy metals are necessary. Fish-derived cells sensitive to heavy metals have been used as valuable tools for ecotoxicological assessments. However, this method requires a minimum toxicity treatment time of 96 h, which limits its use when rapid ecotoxicological assessments are required or ecotoxicological assessments of a large number of toxicants are performed. In this study, these limitations were overcome by adjusting parameters including the concentration of fetal bovine serum (FBS) in the medium and the treatment time of the toxicant. Specifically, we found that the maximum time for fish cells to remain unstarved was 6 h when using a medium containing 1% FBS. We applied both parameters to the ecotoxicological assessment (using a medium containing 1% FBS for the toxicity assessment and treating the toxicant for only 6 h). Surprisingly, these adjusted parameters allowed us to obtain faster and more accurate data than the traditional assessment. This improvement was due to the new assessment conditions that minimized the possibility that the growth-inducing effects of nutrients present in excess in the medium could interfere with the cellular response to the toxicant. The accuracy of this assessment was not limited to measuring the toxicity of heavy metals. In conclusion, we have established an ecotoxicity assessment that can generate rapid and accurate data on heavy metals. This new platform will become the cornerstone of rapid and accurate ecotoxicity assessments of heavy metals.
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Xelaglifam, developed as a GPR40/FFAR1 agonist, induces glucose-dependent insulin secretion and reduces circulating glucose levels for Type 2 diabetes treatment. This study investigated the effects of Xelaglifam in comparison with Fasiglifam on the in vitro/in vivo anti-diabetic efficacy and selectivity, and the mechanistic basis. In vitro studies on downstream targets of Xelaglifam were performed in GPR40-expressing cells. Xelaglifam treatment exhibited dose-dependent effects, increasing inositol phosphate-1, Ca2+ mobilization, and ß-arrestin recruitment (EC50: 0.76â¯nM, 20â¯nM, 68â¯nM), supporting its role in Gq protein-dependent and G-protein-independent mechanisms. Despite a lack of change in the cAMP pathway, the Xelaglifam-treated group demonstrated increased insulin secretion compared to Fasiglifam in HIT-T15 ß cells under high glucose conditions. High doses of Xelaglifam (<30â¯mg/kg) did not induce hypoglycemia in Sprague-Dawley rats. In addition, Xelaglifam lowered glucose and increased insulin levels in diabetic rat models (GK, ZDF, OLETF). In GK rats, 1â¯mg/kg of Xelaglifam improved glucose tolerance (33.4â¯% and 15.6â¯% for the 1 and 5â¯h) after consecutive glucose challenges. Moreover, repeated dosing in ZDF and OLETF rats resulted in superior glucose tolerance (34â¯% and 35.1â¯% in ZDF and OLETF), reducing fasting hyperglycemia (18.3â¯% and 30â¯% in ZDF and OLETF) at lower doses; Xelaglifam demonstrated a longer-lasting effect with a greater effect on ß-cells including 3.8-fold enhanced insulin secretion. Co-treatment of Xelaglifam with SGLT-2 inhibitors showed additive or synergistic effects. Collectively, these results demonstrate the therapeutic efficacy and selectivity of Xelaglifam on GPR40, supportive of its potential for the treatment of Type 2 diabetes.
Assuntos
Glicemia , Diabetes Mellitus Tipo 2 , Receptores Acoplados a Proteínas G , beta-Arrestinas , Animais , Humanos , Masculino , Ratos , beta-Arrestinas/metabolismo , Glicemia/metabolismo , Glicemia/efeitos dos fármacos , Cricetulus , Diabetes Mellitus Experimental/tratamento farmacológico , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Tipo 2/tratamento farmacológico , Diabetes Mellitus Tipo 2/metabolismo , Diabetes Mellitus Tipo 2/sangue , Controle Glicêmico/métodos , Hipoglicemiantes/farmacologia , Insulina/metabolismo , Secreção de Insulina/efeitos dos fármacos , Células Secretoras de Insulina/efeitos dos fármacos , Células Secretoras de Insulina/metabolismo , Ratos Sprague-Dawley , Receptores Acoplados a Proteínas G/agonistas , Receptores Acoplados a Proteínas G/metabolismoRESUMO
Cancer cells are characterized by apoptosis evasion and uncontrolled cell cycle progression. To combat these characteristics, efforts have been made to find novel natural-source anticancer compounds. The aim of this work is to find new anticancer compounds in Polyporus ulleungus (P. ulleungus) mycelial culture extracts. P. ulleungus mycelium was cultured on four individual media (DYB, MEB, MYB, and PDB) and four extracts were generated from the mycelium culture media. Extracts of P. ulleungus mycelium cultured in MEB medium (pu-MEB) significantly reduced cancer cell growth by triggering apoptosis and S phase arrest. Furthermore, the anticancer effects of pu-MEB were not confined to one type of cancer. Taken together, our results confirmed that P. ulleungus mycelia cultured in MEB medium produce metabolites that exhibit anticancer properties. Development of an optimal medium for P. ulleungus mycelium through optimization of medium components will enable P. ulleungus mycelium to produce metabolites with more anticancer efficacy.
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Addressing age-related immunological defects through therapeutic interventions is essential for healthy aging, as the immune system plays a crucial role in controlling infections, malignancies, and in supporting tissue homeostasis and repair. In our study, we show that stimulating toll-like receptor 5 (TLR5) via mucosal delivery of a flagellin-containing fusion protein effectively extends the lifespan and enhances the healthspan of mice of both sexes. This enhancement in healthspan is evidenced by diminished hair loss and ocular lens opacity, increased bone mineral density, improved stem cell activity, delayed thymic involution, heightened cognitive capacity, and the prevention of pulmonary lung fibrosis. Additionally, this fusion protein boosts intestinal mucosal integrity by augmenting the surface expression of TLR5 in a certain subset of dendritic cells and increasing interleukin-22 (IL-22) secretion. In this work, we present observations that underscore the benefits of TLR5-dependent stimulation in the mucosal compartment, suggesting a viable strategy for enhancing longevity and healthspan.
Assuntos
Longevidade , Receptor 5 Toll-Like , Animais , Camundongos , Flagelina/metabolismo , Mucosa Intestinal/metabolismo , Longevidade/genética , Pulmão/metabolismoRESUMO
One of the biggest obstacles in cancer treatment is the development of chemoresistance. To overcome this, attempts have been made to screen novel anticancer substances derived from natural products. The purpose of this study is to find new anticancer candidates in the mycelium culture extract of mushrooms belonging to Polyporus. Here, we used a high-throughput screening to find agents capable of inhibiting cancer cell proliferation. The culture extract of Polyporus Parvovarius mycelium in DY medium (pp-DY) was effective. pp-DY inhibited cancer cell proliferation by inducing apoptosis and S-phase arrest. The anticancer property of pp-DY was not only effective against one type of cancer, but also against another type of cancer. Compound fractionation was performed, and the active ingredient exhibiting anticancer effects in pp-DY was identified as 3,4-dihydroxybenzaldehyde (Protocatechualdehyde, PCA). PCA, like pp-DY, inhibited the proliferation of cancer cells by inducing apoptosis and S-phase arrest. Furthermore, unlike conventional anticancer drugs, PCA did not increase the proportion of the side population that plays the most important role in the development of chemoresistance. Taken together, our data revealed the novel mycelium culture extract that exhibited anticancer property, and identified active ingredients that did not activate a proportion of the side population. These novel findings may have clinical applications in the treatment of cancer, particularly chemo-resistant cancer.
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Senescence is a phenomenon defined by alterations in cellular organelles and is the primary cause of aging and aging-related diseases. Recent studies have shown that oncogene-induced senescence is driven by activation of serine/threonine protein kinases (AKT1, AKT2 and AKT3). In this study, we evaluated twelve AKT inhibitors and revealed GDC0068 as a potential agent to ameliorate senescence. Senescence-ameliorating effect was evident from the finding that GDC0068 yielded lysosomal functional recovery as observed by reduction in lysosomal mass and induction in autophagic flux. Furthermore, GDC0068-mediated restoration of lysosomal function activated the removal of dysfunctional mitochondria, resulting in restoration of mitochondrial function. Together, our findings revealed a unique mechanism by which senescence is recovered by functional restoration of lysosomes and mitochondria through modulation of AKT activity.
Assuntos
Proteínas Serina-Treonina Quinases , Proteínas Proto-Oncogênicas c-akt , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Autofagia , Lisossomos/metabolismo , Mitocôndrias/metabolismo , Senescência CelularRESUMO
Mitochondria are one of the organelles undergoing rapid alteration during the senescence process. Senescent cells show an increase in mitochondrial size, which is attributed to the accumulation of defective mitochondria, which causes mitochondrial oxidative stress. Defective mitochondria are also targets of mitochondrial oxidative stress, and the vicious cycle between defective mitochondria and mitochondrial oxidative stress contributes to the onset and development of aging and age-related diseases. Based on the findings, strategies to reduce mitochondrial oxidative stress have been suggested for the effective treatment of aging and age-related diseases. In this article, we discuss mitochondrial alterations and the consequent increase in mitochondrial oxidative stress. Then, the causal role of mitochondrial oxidative stress on aging is investigated by examining how aging and age-related diseases are exacerbated by induced stress. Furthermore, we assess the importance of targeting mitochondrial oxidative stress for the regulation of aging and suggest different therapeutic strategies to reduce mitochondrial oxidative stress. Therefore, this review will not only shed light on a new perspective on the role of mitochondrial oxidative stress in aging but also provide effective therapeutic strategies for the treatment of aging and age-related diseases through the regulation of mitochondrial oxidative stress.
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Most conventional anticancer drugs cause resistance to chemotherapy, which has emerged as one of the major obstacles to cancer treatment. In order to address this issue, efforts have been made to select new anticancer compounds from natural sources. The aim of this study is to identify novel anticancer compounds from mycelial culture extracts belonging to Polyporus tuberaster (P. tuberaster). Here, we found that mycelial culture extracts of P. tuberaster cultured in PDB medium (pt-PDB) effectively inhibited cancer cell growth. pt-PDB reduced the growth of cancer cells through apoptosis induction and S-phase arrest. The anticancer efficacy of pt-PDB was not to limited to one type of cancer. Furthermore, unlike traditional anticancer medications, pt-PDB did not increase the proportion of side population (SP) cells, which plays a key role in the development of chemoresistance. Taken together, we discovered a novel anticancer drug candidate that has anticancer properties without increasing the proportion of SP cells. This new drug candidate can be used for the treatment of cancer, especially chemoresistant malignancies, and will provide a breakthrough in the treatment of chemoresistant cancer.
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PARP inhibitors have been approved by the FDA for use in the treatment of patients with ovarian, breast, pancreatic, and prostate cancers. PARP inhibitors show diverse suppressive effects on PARP family members and PARP-DNA trapping potency. These properties are associated with distinct safety/efficacy profiles. Here, we report the nonclinical characteristics of venadaparib (also known as IDX-1197 or NOV140101), a novel potent PARP inhibitor. The physiochemical properties of venadaparib were analyzed. Furthermore, the efficacy of venadaparib against PARP enzymes, PAR formation, and PARP trapping activities, and growth inhibition of cell lines with BRCA mutations were evaluated. Ex vivo and in vivo models were also established to study pharmacokinetics/pharmacodynamics, efficacy, and toxicity. Venadaparib specifically inhibits PARP-1 and -2 enzymes. Oral administration of venadaparib HCl at doses above 12.5 mg/kg significantly reduced tumor growth in the OV_065 patient-derived xenograft model. Intratumoral PARP inhibition remained at over 90% until 24 hours after dosing. Venadaparib had wider safety margins than olaparib. Notably, venadaparib showed favorable physicochemical properties and superior anticancer effects in homologous recombination-deficient in vitro and in vivo models with improved safety profiles. Our results suggest the possibility of venadaparib as a next-generation PARP inhibitor. On the basis of these findings, phase Ib/IIa studies on the efficacy and safety of venadaparib have been initiated.
Assuntos
Antineoplásicos , Inibidores de Poli(ADP-Ribose) Polimerases , Masculino , Humanos , Inibidores de Poli(ADP-Ribose) Polimerases/farmacologia , Inibidores de Poli(ADP-Ribose) Polimerases/uso terapêutico , Linhagem Celular Tumoral , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Recombinação HomólogaRESUMO
Continuously renewing the proteome, translation is exquisitely controlled by a number of dedicated factors that interact with the ribosome. The RNA helicase DDX3 belonging to the DEAD box family has emerged as one of the critical regulators of translation, the failure of which is frequently observed in a wide range of proliferative, degenerative, and infectious diseases in humans. DDX3 unwinds double-stranded RNA molecules with coupled ATP hydrolysis and thereby remodels complex RNA structures present in various protein-coding and noncoding RNAs. By interacting with specific features on messenger RNAs (mRNAs) and 18S ribosomal RNA (rRNA), DDX3 facilitates translation, while repressing it under certain conditions. We review recent findings underlying these properties of DDX3 in diverse modes of translation, such as cap-dependent and cap-independent translation initiation, usage of upstream open reading frames, and stress-induced ribonucleoprotein granule formation. We further discuss how disease-associated DDX3 variants alter the translation landscape in the cell. [BMB Reports 2022; 55(3): 125-135].
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RNA Helicases DEAD-box , Ribossomos , RNA Helicases DEAD-box/genética , RNA Helicases DEAD-box/metabolismo , Humanos , RNA Mensageiro , Ribonucleoproteínas/genética , Ribossomos/metabolismoRESUMO
Senescence is a distinct set of changes in the senescence-associated secretory phenotype (SASP) and leads to aging and age-related diseases. Here, we screened compounds that could ameliorate senescence and identified an oxazoloquinoline analog (KB1541) designed to inhibit IL-33 signaling pathway. To elucidate the mechanism of action of KB1541, the proteins binding to KB1541 were investigated, and an interaction between KB1541 and 14-3-3ζ protein was found. Specifically, KB1541 interacted with 14-3-3ζ protein and phosphorylated of 14-3-3ζ protein at serine 58 residue. This phosphorylation increased ATP synthase 5 alpha/beta dimerization, which in turn promoted ATP production through increased oxidative phosphorylation (OXPHOS) efficiency. Then, the increased OXPHOS efficiency induced the recovery of mitochondrial function, coupled with senescence alleviation. Taken together, our results demonstrate a mechanism by which senescence is regulated by ATP synthase 5 alpha/beta dimerization upon fine-tuning of KB1541-mediated 14-3-3ζ protein activity.