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1.
Eur J Med Chem ; 271: 116444, 2024 May 05.
Article in English | MEDLINE | ID: mdl-38691889

ABSTRACT

The NAPRT-induced increase in NAD+ levels was proposed as a mechanism contributing to hepatocellular carcinoma (HCC) resistance to NAMPT inhibitors. Thus, concurrently targeting NAMPT and NAPRT could be considered to overcome drug resistance. A BRD4 inhibitor downregulates the expression of NAPRT in HCC, and the combination of NAMPT inhibitors with BRD4 inhibitors simultaneously blocks NAD+ generation via salvage and the PH synthesis pathway. Moreover, the combination of the two agents significantly downregulated the expression of tumor-promoting genes and strongly promoted apoptosis. The present work identified various NAMPT/BRD4 dual inhibitors based on the multitargeted drug rationale. Among them, compound A2, which demonstrated the strongest effect, exhibited potent inhibition of NAMPT and BRD4 (IC50 = 35 and 58 nM, respectively). It significantly suppressed the growth and migration of HCC cells and facilitated their apoptosis. Furthermore, compound A2 also manifested a robust anticancer effect in HCCLM3 xenograft mouse models, with no apparent toxic effects. Our findings in this study provide an effective approach to target NAD+ metabolism for HCC treatment.


Subject(s)
Antineoplastic Agents , Apoptosis , Carcinoma, Hepatocellular , Cell Cycle Proteins , Cell Proliferation , Cytokines , Liver Neoplasms , Nicotinamide Phosphoribosyltransferase , Transcription Factors , Nicotinamide Phosphoribosyltransferase/antagonists & inhibitors , Nicotinamide Phosphoribosyltransferase/metabolism , Humans , Carcinoma, Hepatocellular/drug therapy , Carcinoma, Hepatocellular/pathology , Carcinoma, Hepatocellular/metabolism , Liver Neoplasms/drug therapy , Liver Neoplasms/pathology , Liver Neoplasms/metabolism , Animals , Antineoplastic Agents/pharmacology , Antineoplastic Agents/chemistry , Antineoplastic Agents/chemical synthesis , Cell Proliferation/drug effects , Mice , Apoptosis/drug effects , Structure-Activity Relationship , Transcription Factors/antagonists & inhibitors , Transcription Factors/metabolism , Cell Cycle Proteins/antagonists & inhibitors , Cell Cycle Proteins/metabolism , Cytokines/metabolism , Cytokines/antagonists & inhibitors , Drug Discovery , Drug Screening Assays, Antitumor , Molecular Structure , Dose-Response Relationship, Drug , Mice, Nude , Cell Line, Tumor , Mice, Inbred BALB C , Bromodomain Containing Proteins
2.
Int J Biol Macromol ; 263(Pt 1): 130163, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38367783

ABSTRACT

The purpose of this work is to prepare a novel acetylated derivative of Undaria pinnatifida fucoidan (UPFUC) with admirable antitumor activity. Fucoidan was first acetylated by acetylsalicylic acid (aspirin, ASA) to form the ASA-UPFUC complex. The antitumor efficacy results stated that ASA-UPFUC inhibited the proliferation of human non-small cell lung cancer A549 cells in a dose-dependent manner, with an IC50 value of 49.09 µg/mL, 50.20 % lower than that of UPFUC. Importantly, the acetylation process had no adverse effects on the backbone structure of UPFUC. Simultaneously, ASA-UPFUC demonstrated a larger charge density than UPFUC, leading to enhanced solubility, improved surface charge effects, and a greater potential for exerting biological activity. Consequently, ASA-UPFUC increased the formation of alkyl and hydrogen bonds with tumor necrosis factor related apoptosis-inducing ligand receptors DR4 and DR5, thereby effectively stimulating the generation of cellular reactive oxygen species, diminishing mitochondrial membrane potential, suppressing nuclear factor κB (NFκB) p65 phosphorylation, enhancing the contents of Bax and cleaved caspase 3, and reducing the level of Bcl-2. The collective effects ultimately triggered the mitochondrial apoptotic pathway, leading to apoptosis in A549 cells. The findings support the potential utilization of ASA-UPFUC as a novel dietary additive for human lung cancer chemoprevention.


Subject(s)
Carcinoma, Non-Small-Cell Lung , Edible Seaweeds , Lung Neoplasms , Polysaccharides , Undaria , Humans , Carcinoma, Non-Small-Cell Lung/pathology , Lung Neoplasms/pathology , Aspirin/pharmacology , Apoptosis , Cell Proliferation , Cell Line, Tumor
3.
Sci Total Environ ; 919: 170976, 2024 Apr 01.
Article in English | MEDLINE | ID: mdl-38360321

ABSTRACT

The urgent need for decarbonization in China's heating system, comprised of approximately one hundred thousand boilers, is imperative to meet climate and clean air objectives. To formulate national and regional strategies, we developed an integrated model framework that combines a facility-level emission inventory, the Community Multiscale Air Quality (CMAQ) model, and the Global Exposure Mortality Model (GEMM). We then explore the air quality and health benefits of alternative heating decarbonization pathways, including the retirement of coal-fired industrial boilers (CFIBs) for replacement with grid-bound heat supply systems, coal-to-gas conversion, and coal-to-biomass conversion. The gas replacement pathway shows the greatest potential for reducing PM2.5 concentration by 2.8 (2.3-3.4) µg/m3 by 2060, avoiding 23,100 (19,600-26,500) premature deaths. In comparison, the biomass replacement pathway offers slightly lower environmental and health benefits, but is likely to reduce costs by approximately two-thirds. Provincially, optimal pathways vary - Xinjiang, Sichuan, and Chongqing favor coal-to-gas conversion, while Shandong, Henan, Hebei, Inner Mongolia, and Shanxi show promise in CFIBs retirement. Henan leads in environmental and health benefits. Liaoning, Heilongjiang, and Jilin, rich in biomass resources, present opportunities for coal-to-biomass conversion.


Subject(s)
Air Pollutants , Air Pollution , Particulate Matter/analysis , Heating , Air Pollution/prevention & control , Air Pollution/analysis , China , Coal/analysis , Air Pollutants/analysis
4.
Int J Mol Sci ; 24(23)2023 Nov 27.
Article in English | MEDLINE | ID: mdl-38069153

ABSTRACT

Telomeres are nucleoprotein complexes that cap the ends of eukaryotic linear chromosomes. Telomeric DNA is bound by shelterin protein complex to prevent telomeric chromosome ends from being recognized as damaged sites for abnormal repair. To overcome the end replication problem, cancer cells mostly preserve their telomeres by reactivating telomerase, but a minority (10-15%) of cancer cells use a homologous recombination-based pathway called alternative lengthening of telomeres (ALT). Recent studies have found that shelterin components play an important role in the ALT mechanism. The binding of TRF1, TRF2, and RAP1 to telomeres attenuates ALT activation, while the maintenance of ALT telomere requires TRF1 and TRF2. POT1 and TPP1 can also influence the occurrence of ALT. The elucidation of how shelterin regulates the initiation of ALT remains elusive. This review presents a comprehensive overview of the current findings on the regulation of ALT by shelterin components, aiming to enhance the insight into the altered functions of shelterin components in ALT cells and to identify potential targets for the treatment of ALT tumor cells.


Subject(s)
Telomerase , Telomere-Binding Proteins , Telomere-Binding Proteins/metabolism , Shelterin Complex , Telomere/genetics , Telomere/metabolism , Telomere Homeostasis , Telomerase/metabolism , Telomeric Repeat Binding Protein 2
5.
Aging (Albany NY) ; 15(19): 10767-10784, 2023 10 12.
Article in English | MEDLINE | ID: mdl-37827695

ABSTRACT

The G-rich DNA, such as telomere, tends to form G-quadruplex (G4) structure, which slows down the replication fork progression, induces replication stress, and becomes the chromosome fragile sites. Here we described a molecular strategy that cells developed to overcome the DNA replication stress via DNA helicase regulation. The p53N236S (p53S) mutation has been found in the Werner syndrome mouse embryo fibroblast (MEFs) escaped from senescence, could be the driving force for cell escaping senescence. We revealed that the p53S could transcriptionally up-regulate DNA helicases expression, including Wrn, Blm, Timeless, Ddx, Mcm, Gins, Fanc, as well as telomere specific proteins Terf1, Pot1, through which p53S promoted the unwinding of G4 structures, and protected the cells from DNA replication stress induced by G4 stabilizer. By modified iPOND (isolation of proteins on nascent DNA) assay and telomere assay, we demonstrated that the p53S could promote the recruitment of those helicases to the DNA replication forks, facilitated the maintenance of telomere, and prevent the telomere dysfunction induced by G4 stabilizer. Interestingly, we did not observe the function of promoting G4 resolving and facilitating telomere lengthening in the cells with Li-Fraumeni Syndrome mutation-p53R172H (p53H), which suggests that this is the specific gain of function for p53S. Together our data suggest that the p53S could gain the new function of releasing the replication stress via regulating the helicase function and G4 structure, which benefits telomere lengthening. This strategy could be applied to the treatment of diseases caused by telomere replication stress.


Subject(s)
DNA Replication , Werner Syndrome , Animals , Mice , Tumor Suppressor Protein p53/genetics , Tumor Suppressor Protein p53/metabolism , Werner Syndrome Helicase/genetics , DNA Helicases/genetics , DNA Helicases/metabolism , DNA/genetics , Telomere/genetics , Telomere/metabolism , RecQ Helicases/genetics , RecQ Helicases/metabolism
6.
J Colloid Interface Sci ; 652(Pt A): 305-316, 2023 Dec 15.
Article in English | MEDLINE | ID: mdl-37597412

ABSTRACT

MnO2 cathode materials have presented challenges due to their poor conductivity, unstable structure, and sluggish diffusion kinetics for aqueous zinc-ion batteries (AZIBs). In this study, a nanostructured MnOx cathode material was synthesized using an acid etching method, Which introduced abundant Mn(III) sites, resulting in the formation of numerous oxygen vacancies. Comprehensive characterizations revealed that these oxygen vacancies facilitated the reversible adsorption/desorption of Zn2+ ions and promoted efficient electron transfer. In addition, the designed mesoporous structure offered ample active sites and shortened the diffusion path for Zn2+ and H+ ions. Consequently, the nanosized MnOx cathode exhibited enhanced reaction kinetics, achieving a considerable reversible specific capacity of 388.7 mAh/g at 0.1 A/g and superior durability with 72.0% capacity retention over 2000 cycles at 3.0 A/g. The material delivered a maximum energy density of 639.7 Wh kg-1 at 159.94 W kg-1. Furthermore, a systematic analysis of the zinc storage mechanism was performed. This work demonstrates that engineering oxygen vacancies with nanostructure regulation provides valuable insights into optimizing MnO2 cathode materials for AZIBs.

7.
Aging Cell ; 22(8): e13896, 2023 08.
Article in English | MEDLINE | ID: mdl-37312431

ABSTRACT

Senescent cells (SnCs) are implicated in aging and various age-related pathologies. Targeting SnCs can treat age-related diseases and extend health span. However, precisely tracking and visualizing of SnCs is still challenging, especially in in vivo environments. Here, we developed a near-infrared (NIR) fluorescent probe (XZ1208) that targets ß-galactosidase (ß-Gal), a well-accepted biomarker for cellular senescence. XZ1208 can be cleaved rapidly by ß-Gal and produces a strong fluorescence signal in SnCs. We demonstrated the high specificity and sensitivity of XZ1208 in labeling SnCs in naturally aged, total body irradiated (TBI), and progeroid mouse models. XZ1208 achieved a long-term duration of over 6 days in labeling senescence without causing significant toxicities and accurately detected the senolytic effects of ABT263 on eliminating SnCs. Furthermore, XZ1208 was applied to monitor SnCs accumulated in fibrotic diseases and skin wound healing models. Overall, we developed a tissue-infiltrating NIR probe and demonstrated its excellent performance in labeling SnCs in aging and senescence-associated disease models, indicating great potential for application in aging studies and diagnosis of senescence-associated diseases.


Subject(s)
Aging , Fluorescent Dyes , Mice , Animals , Fluorescent Dyes/pharmacology , Aging/pathology , Cellular Senescence , Disease Models, Animal , Fibrosis , beta-Galactosidase
8.
Cancers (Basel) ; 15(9)2023 May 06.
Article in English | MEDLINE | ID: mdl-37174106

ABSTRACT

Melanoma is a malignant skin tumor that originates from melanocytes. The pathogenesis of melanoma involves a complex interaction that occurs between environmental factors, ultraviolet (UV)-light damage, and genetic alterations. UV light is the primary driver of the skin aging process and development of melanoma, which can induce reactive oxygen species (ROS) production and the presence of DNA damage in the cells, and results in cell senescence. As cellular senescence plays an important role in the relationship that exists between the skin aging process and the development of melanoma, the present study provides insight into the literature concerning the topic at present and discusses the relationship between skin aging and melanoma, including the mechanisms of cellular senescence that drive melanoma progression, the microenvironment in relation to skin aging and melanoma factors, and the therapeutics concerning melanoma. This review focuses on defining the role of cellular senescence in the process of melanoma carcinogenesis and discusses the targeting of senescent cells through therapeutic approaches, highlighting the areas that require more extensive research in the field.

9.
Int J Mol Sci ; 24(7)2023 Mar 31.
Article in English | MEDLINE | ID: mdl-37047529

ABSTRACT

Accumulating evidence indicates that the increased burden of senescent cells (SCs) in aged organisms plays an important role in many age-associated diseases. The pharmacological elimination of SCs with "senolytics" has been emerging as a new therapy for age-related diseases and extending the healthy lifespan. In the present study, we identified that cycloastragenol (CAG), a secondary metabolite isolated from Astragalus membrananceus, delays age-related symptoms in mice through its senolytic activity against SCs. By screening a series of compounds, we found that CAG selectively kills SCs by inducing SCs apoptosis and that this process is associated with the inhibition of Bcl-2 antiapoptotic family proteins and the PI3K/AKT/mTOR pathway. In addition, CAG treatment also suppressed the development of the senescence-associated secretory phenotype (SASP) in SCs, thereby inhibiting cell migration mediated by the SASP. Furthermore, the administration of CAG for 2 weeks to mice with irradiation-induced aging alleviated the burden of SCs and improved the animals' age-related physical dysfunction. Overall, our studies demonstrate that CAG is a novel senolytic agent with in vivo activity that has the potential to be used in the treatment of age-related diseases.


Subject(s)
Cellular Senescence , Phosphatidylinositol 3-Kinases , Animals , Mice , Cellular Senescence/physiology , Aging , Proto-Oncogene Proteins c-bcl-2 , Apoptosis
10.
Int J Mol Sci ; 24(4)2023 Feb 14.
Article in English | MEDLINE | ID: mdl-36835200

ABSTRACT

One of the key steps in tumorigenic transformation is immortalization in which cells bypass cancer-initiating barriers such as senescence. Senescence can be triggered by either telomere erosion or oncogenic stress (oncogene-induced senescence, OIS) and undergo p53- or Rb-dependent cell cycle arrest. The tumor suppressor p53 is mutated in 50% of human cancers. In this study, we generated p53N236S (p53S) mutant knock-in mice and observed that p53S heterozygous mouse embryonic fibroblasts (p53S/+) escaped HRasV12-induced senescence after subculture in vitro and formed tumors after subcutaneous injection into severe combined immune deficiency (SCID) mice. We found that p53S increased the level and nuclear translocation of PGC-1α in late-stage p53S/++Ras cells (LS cells, which bypassed the OIS). The increase in PGC-1α promoted the biosynthesis and function of mitochondria in LS cells by inhibiting senescence-associated reactive oxygen species (ROS) and ROS-induced autophagy. In addition, p53S regulated the interaction between PGC-1α and PPARγ and promoted lipid synthesis, which may indicate an auxiliary pathway for facilitating cell escape from aging. Our results illuminate the mechanisms underlying p53S mutant-regulated senescence bypass and demonstrate the role played by PGC-1α in this process.


Subject(s)
Cellular Senescence , Gain of Function Mutation , Tumor Suppressor Protein p53 , Animals , Mice , Cellular Senescence/genetics , Fibroblasts/metabolism , Mutation , Proto-Oncogene Proteins p21(ras)/genetics , Reactive Oxygen Species/metabolism , Tumor Suppressor Protein p53/genetics , Tumor Suppressor Protein p53/metabolism
11.
J Food Biochem ; 46(9): e14371, 2022 09.
Article in English | MEDLINE | ID: mdl-35933693

ABSTRACT

Polysaccharides derived from edible mushrooms were sources of new prebiotic compounds. Limited studies of their prebiotic effects, as well as the presence of residual dark colors, impede their use as prebiotics in the food industry. To boost the prebiotic value of polysaccharides from the edible mushroom Ramaria flava, a decolorization method, and the physicochemical characterization and prebiotic potential of the decolorized polysaccharide (DRFP) were investigated in this study. The reversed micelle system consisting of n-hexanol/isooctane (3:7, v/v) and 200 mM surfactant (CTAB) was an appropriate decolorized method for R. flava crude polysaccharide. That decolorized polysaccharide was 101.68 kDa and contained glucose, galactose, mannose, fucose, xylose, rhamnose, arabinose, and glucuronic acid in a ratio of 40.61:26.97:17.72:7.78:6.31:0.11:0.06:0.44. Furthermore, DRFP exhibited typical shear-thinning behavior and possessed good thermal stability. And 98.76% of DRFP was allowed to transit through the oral cavity and gastrointestinal tract nearly indigestibly in vitro fermentation. It also revealed a prebiotic availability through stimulating Lactobacillus rhamnosus proliferation and inducing enterocoel acidification. When utilized as a carbon source, DRFP significantly improves the production of short-chain fatty acids by L. rhamnosus, particularly acetic, propionic, isobutyric, and hexanoic acids. Therefore, this work suggests the further application of R. flava polysaccharides as emerging prebiotics, which may be used as an ingredient in functional food and nutraceutical products. PRACTICAL APPLICATIONS: Prebiotics could regulate gut microbial community and are closely associated with host health. This work reported that a decolorized polysaccharide (DRFP) prepared from the edible mushroom Ramaria flava was indigestible and could improve Lactobacillus rhamnosus proliferation and short-chain fatty acid production, which could provide useful information for the application of DRFP as a prebiotic additive in the food industry.


Subject(s)
Agaricales , Basidiomycota , Agaricales/chemistry , Polysaccharides/chemistry , Polysaccharides/pharmacology , Prebiotics
12.
Int J Mol Sci ; 23(15)2022 Aug 04.
Article in English | MEDLINE | ID: mdl-35955822

ABSTRACT

The complement system is a part of the immune system and consists of multiple complement components with biological functions such as defense against pathogens and immunomodulation. The complement system has three activation pathways: the classical pathway, the lectin pathway, and the alternative pathway. Increasing evidence indicates that the complement system plays a role in aging. Complement plays a role in inflammatory processes, metabolism, apoptosis, mitochondrial function, and Wnt signaling pathways. In addition, the complement system plays a significant role in aging-related diseases, including Alzheimer's disease, age-related macular degeneration, and osteoarthritis. However, the effect of complement on aging and aging-related diseases is still unclear. Thus, a better understanding of the potential relationship between complement, aging, and aging-related diseases will provide molecular targets for treating aging, while focusing on the balance of complement in during treatment. Inhibition of a single component does not result in a good outcome. In this review, we discussed the research progress and effects of complement in aging and aging-related diseases.


Subject(s)
Complement System Proteins , Macular Degeneration , Aging , Complement Activation , Complement System Proteins/metabolism , Humans , Lectins
13.
Genes (Basel) ; 13(5)2022 04 26.
Article in English | MEDLINE | ID: mdl-35627147

ABSTRACT

Hypoxia can lead to stabilization of the tumor suppressor gene p53 and cell death. However, p53 mutations could promote cell survival in a hypoxic environment. In this study, we found that p53N236S (p53N239S in humans, hereinafter referred to as p53S) mutant mouse embryonic fibroblasts (MEFs) resistant to deferoxamine (DFO) mimic a hypoxic environment. Further, Western blot and flow cytometry showed reduced apoptosis in p53S/S cells compared to WT after DFO treatment, suggesting an antiapoptosis function of p53S mutation in response to hypoxia-mimetic DFO. Instead, p53S/S cells underwent autophagy in response to hypoxia stress presumably through inhibition of the AKT/mTOR pathway, and this process was coupled with nuclear translocation of p53S protein. To understand the relationship between autophagy and apoptosis in p53S/S cells in response to hypoxia, the autophagic inhibitor 3-MA was used to treat both WT and p53S/S cells after DFO exposure. Both apoptotic signaling and cell death were enhanced by autophagy inhibition in p53S/S cells. In addition, the mitochondrial membrane potential (MMP) and the ROS level results indicated that p53S might initiate mitophagy to clear up damaged mitochondria in response to hypoxic stress, thus increasing the proportion of intact mitochondria and maintaining cell survival. In conclusion, the p53S mutant activates autophagy instead of inducing an apoptotic process in response to hypoxia stress to protect cells from death.


Subject(s)
Deferoxamine/pharmacology , Fibroblasts , Tumor Suppressor Protein p53/metabolism , Animals , Apoptosis/genetics , Autophagy/genetics , Fibroblasts/metabolism , Hypoxia/genetics , Mice , Tumor Suppressor Protein p53/genetics
14.
Cancers (Basel) ; 14(9)2022 Apr 27.
Article in English | MEDLINE | ID: mdl-35565323

ABSTRACT

Telomeres are DNA-protein complexes that protect eukaryotic chromosome ends from being erroneously repaired by the DNA damage repair system, and the length of telomeres indicates the replicative potential of the cell. Telomeres shorten during each division of the cell, resulting in telomeric damage and replicative senescence. Tumor cells tend to ensure cell proliferation potential and genomic stability by activating telomere maintenance mechanisms (TMMs) for telomere lengthening. The alternative lengthening of telomeres (ALT) pathway is the most frequently activated TMM in tumors of mesenchymal and neuroepithelial origin, and ALT also frequently occurs during experimental cellular immortalization of mesenchymal cells. ALT is a process that relies on homologous recombination (HR) to elongate telomeres. However, some processes in the ALT mechanism remain poorly understood. Here, we review the most recent understanding of ALT mechanisms and processes, which may help us to better understand how the ALT pathway is activated in cancer cells and determine the potential therapeutic targets in ALT pathway-stabilized tumors.

15.
Aging (Albany NY) ; 14(9): 3941-3955, 2022 05 10.
Article in English | MEDLINE | ID: mdl-35537009

ABSTRACT

Si Jun Zi Tang (SJZT) is a classic Traditional Chinese Medicine (TCM) prescription used to treat aging-related diseases. However, the potential molecular mechanisms of the anti-aging effects of the bioactive compounds and their targets remain elusive. In this study, we combined network pharmacology and molecular docking with in vivo experiments to elucidate the anti-aging molecular mechanism of SJZT. A series of network pharmacology strategies were used to predict potential targets and therapeutic mechanisms of SJZT, including compound screening, pathway enrichment analysis and molecular docking studies. Based on the network pharmacology predictions and observation of outward signs of aging, the expression levels of selected genes and proteins and possible key targets were subsequently validated and analysed using qRT-PCR and immunoblotting. Using a data mining approach, 235 effective targets of SJZT and aging were obtained. AKT1, STAT3, JUN, MAPK3, TP53, MAPK1, TNF, RELA, MAPK14 and IL6 were identified as core genes in the Protein-Protein Interaction Networks (PPI) analysis. The results of the effective target Gene Ontology (Go) functional enrichment analysis suggested that SJZT may be involved aging and antiapoptotic biological processes. The Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis indicated that the anti-aging mechanism of SJZT may be associated with the PI3K-AKT and P38 MAPK signalling pathways. Molecular docking analysis suggested that kaempferol and quercetin could fit in the binding pockets of the core targets. In addition, SJZT alleviated the aging symptoms of mice such as osteoporosis and hair loss. In conclusion, the anti-aging effect of SJZT was associated with the inhibition of the PI3K-AKT and P38 MAPK signalling pathways, and these findings were consistent with the network pharmacology prediction.


Subject(s)
Phosphatidylinositol 3-Kinases , Proto-Oncogene Proteins c-akt , Aging , Animals , Mice , Molecular Docking Simulation , Network Pharmacology , p38 Mitogen-Activated Protein Kinases
16.
Front Oncol ; 12: 811747, 2022.
Article in English | MEDLINE | ID: mdl-35198445

ABSTRACT

Hepatocellular carcinoma is one of the most common primary malignant tumors of the digestive system. Compound 5-chloro-N'-(2,4-dimethoxybenzylidene)-1H-indole-2-carbohydrazide (IHZ-1/ZJQ-24) is a novel indole hydrazide derivative. In a recent study, we demonstrated that IHZ-1 inhibits tumor growth and induces cell apoptosis through inhibiting the kinase activity of mTORC1 without activation of AKT, which is associated with JNK/IRS-1 activation. However, the impact and mechanisms of JNK activation by IHZ-1 in hepatocellular carcinoma remains entirely unknown. Here, we find that IHZ-1 increases the generation of intracellular ROS and enhances autophagy. The phosphorylation of JNK induced by IHZ-1 was reversed by the decreased ROS level. Moreover, inhibition of ROS/JNK or autophagy equally attenuated apoptotic effect induced by IHZ-1. Our findings suggest that the activation of JNK by IHZ-1 treatment is dependent on the generation of ROS that mediates apoptosis and autophagy in hepatocellular carcinoma.

17.
Genes (Basel) ; 13(2)2022 01 20.
Article in English | MEDLINE | ID: mdl-35205225

ABSTRACT

Fanconi anaemia (FA)-related proteins function in interstrand crosslink (ICL) repair pathways and multiple damage repair pathways. Recent studies have found that FA proteins are involved in the regulation of replication stress (RS) in alternative lengthening of telomeres (ALT). Since ALT cells often exhibit high-frequency ATRX mutations and high levels of telomeric secondary structure, high levels of DNA damage and replicative stress exist in ALT cells. Persistent replication stress is required to maintain the activity of ALT mechanistically, while excessive replication stress causes ALT cell death. FA proteins such as FANCD2 and FANCM are involved in the regulation of this balance by resolving or inhibiting the formation of telomere secondary structures to stabilize stalled replication forks and promote break-induced repair (BIR) to maintain the survival of ALT tumour cells. Therefore, we review the role of FA proteins in replication stress in ALT cells, providing a rationale and direction for the targeted treatment of ALT tumours.


Subject(s)
Telomere Homeostasis , Telomere , DNA Repair/genetics , Fanconi Anemia Complementation Group A Protein/genetics , Fanconi Anemia Complementation Group Proteins/genetics , Telomere/genetics , Telomere/metabolism , Telomere Homeostasis/genetics
18.
Nat Commun ; 12(1): 5514, 2021 09 17.
Article in English | MEDLINE | ID: mdl-34535663

ABSTRACT

Human shelterin components POT1 and TPP1 form a stable heterodimer that protects telomere ends from ATR-dependent DNA damage responses and regulates telomerase-dependent telomere extension. Mice possess two functionally distinct POT1 proteins. POT1a represses ATR/CHK1 DNA damage responses and the alternative non-homologous end-joining DNA repair pathway while POT1b regulates C-strand resection and recruits the CTC1-STN1-TEN1 (CST) complex to telomeres to mediate C-strand fill-in synthesis. Whether POT1a and POT1b are involved in regulating the length of the telomeric G-strand is unclear. Here we demonstrate that POT1b, independent of its CST function, enhances recruitment of telomerase to telomeres through three amino acids in its TPP1 interacting C-terminus. POT1b thus coordinates the synthesis of both telomeric G- and C-strands. In contrast, POT1a negatively regulates telomere length by inhibiting telomerase recruitment to telomeres. The identification of unique amino acids between POT1a and POT1b helps us understand mechanistically how human POT1 switches between end protective functions and promoting telomerase recruitment.


Subject(s)
DNA-Binding Proteins/metabolism , Telomerase/metabolism , Telomere-Binding Proteins/metabolism , Telomere/metabolism , Animals , CRISPR-Cas Systems/genetics , DNA Mutational Analysis , Mice , Protein Binding , Rad51 Recombinase/metabolism , Sarcoma/pathology
19.
Front Genet ; 12: 597566, 2021.
Article in English | MEDLINE | ID: mdl-33633779

ABSTRACT

Human Werner syndrome (WS) is an autosomal recessive progeria disease. A mouse model of WS manifests the disease through telomere dysfunction-induced aging phenotypes, which might result from cell cycle control and cellular senescence. Both p21Waf1/Cip1 (p21, encoded by the Cdkn1a gene) and p16Ink4a (p16, encoded by the Ink4a gene) are cell cycle inhibitors and are involved in regulating two key pathways of cellular senescence. To test the effect of p21 and p16 deficiencies in WS, we crossed WS mice (DKO) with p21 -/- or p16 -/- mice to construct triple knockout (p21-TKO or p16-TKO) mice. By studying the survival curve, bone density, regenerative tissue (testis), and stem cell capacity (intestine), we surprisingly found that p21-TKO mice displayed accelerated premature aging compared with DKO mice, while p16-TKO mice showed attenuation of the aging phenotypes. The incidence of apoptosis and cellular senescence were upregulated in p21-TKO mice tissue and downregulated in p16-TKO mice. Surprisingly, cellular proliferation in p21-TKO mice tissue was also upregulated, and the p21-TKO mice did not show telomere shortening compared with age-matched DKO mice, although p16-TKO mice displayed obvious enhancement of telomere lengthening. Consistent with these phenotypes, the SIRT1-PGC1 pathway was upregulated in p16-TKO but downregulated in p21-TKO compared with DKO mouse embryo fibroblasts (MEFs). However, the DNA damage response pathway was highly activated in p21-TKO, but rescued in p16-TKO, compared with DKO MEFs. These data suggest that p21 protected the stem cell reservoir by regulating cellular proliferation and turnover at a proper rate and that p21 loss in WS activated fairly severe DNA damage responses (DDR), which might cause an abnormal increase in tissue homeostasis. On the other hand, p16 promoted cellular senescence by inhibiting cellular proliferation, and p16 deficiency released this barrier signal without causing severe DDR.

20.
Medicine (Baltimore) ; 98(31): e16539, 2019 Aug.
Article in English | MEDLINE | ID: mdl-31374015

ABSTRACT

BACKGROUND: Chronic stable angina (CSA) is a cardiovascular disease with high prevalence. At present, drug treatment is still the main measure of stable angina pectoris. Traditional Chinese medicine has a long history in the treatment of CSA. Qi stagnation and Blood stasis syndrome is a common syndrome of CSA. Xinnaoning (XNN) capsule is considered as an effective adjuvant treatment for CSA with the efficacy of promoting qi and blood circulation but lack of high-quality clinical evidence. The purpose of this study is to evaluate the efficacy and safety of XNN capsule compared with placebo by clinical trial. METHODS: This multicenter, randomized, double-blind, placebo-controlled trial will be conducted with a total of 240 participants diagnosed with chronic stable angina (qi stagnation and blood stasis syndrome). The participants will be randomized (1:1) into groups receiving either XNN or placebo for 12 weeks. After a 2-week run-in period, they will receive either XNN or placebo (3 pills, 3 times daily) for 12 weeks on the basis of conventional therapy. The primary outcomes include changes in the integral scores of angina symptoms. The secondary outcome measures include changes in the total score of traditional Chinese medicine syndrome, severity grading of angina pectoris, the number of angina pectoris per week, nitroglycerin dosage, score of seattle angina scale, serum homocysteine, incidence of cardiovascular events. Safety outcomes will also be assessed. Adverse events will be monitored throughout the trial. RESULTS: This study will investigate whether XNN capsule can alleviate clinical symptoms, and improve quality of life of patients with chronic stable angina (qi stagnation and blood stasis syndrome). The results of this study will provide clinical evidence for the application of XNN capsule in the treatment of chronic stable angina. TRIAL REGISTRATION: ClinicalTrials.gov: NCT03914131.


Subject(s)
Angina, Stable/therapy , Adult , Aged , Analysis of Variance , Chi-Square Distribution , Coronary Angiography/methods , Double-Blind Method , Female , Homocysteine/analysis , Homocysteine/blood , Humans , Male , Medicine, Chinese Traditional/methods , Medicine, Chinese Traditional/standards , Middle Aged , Placebos , Surveys and Questionnaires , Treatment Outcome
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