Pyrus pyrifolia Nakai‘Whangkeumbae'is a sand pear fruit with excellent nutritional quality and taste.However,the industrial development of pear fruit is significantly limited by its short shelf life.Salicylic aci...Pyrus pyrifolia Nakai‘Whangkeumbae'is a sand pear fruit with excellent nutritional quality and taste.However,the industrial development of pear fruit is significantly limited by its short shelf life.Salicylic acid(SA),a well-known phytohormone,can delay fruit senescence and improve shelf life.However,the mechanism by which SA regulates CONSTANS-LIKE genes(COLs)during fruit senescence and the role of COL genes in mediating fruit senescence in sand pear are poorly understood.In this study,22 COL genes were identified in sand pear,including four COLs(Pp COL8,Pp COL9a,Pp COL9b,and Pp COL14)identified via transcriptome analysis and 18 COLs through genome-wide analysis.These COL genes were divided into three subgroups according to the structural domains of the COL protein.Pp COL8,with two B-box motifs and one CCT domain,belonged to the first subgroup.In contrast,the other three Pp COLs,Pp COL9a,Pp COL9b,and Pp COL14,with similar conserved protein domains and gene structures,were assigned to the third subgroup.The four COLs showed different expression patterns in pear tissues and were preferentially expressed at the early stage of fruit development.Moreover,the expression of Pp COL8 was inhibited by exogenous SA treatment,while SA up-regulated the expression of Pp COL9a and Pp COL9b.Interestingly,Pp COL8 interacts with Pp MADS,a MADS-box protein preferentially expressed in fruit,and SA up-regulated its expression.While the production of ethylene and the content of malondialdehyde(MDA)were increased in Pp COL8-overexpression sand pear fruit,the antioxidant enzyme(POD and SOD)activity and the expression of Pp POD1 and Pp SOD1 in the sand pear fruits were down-regulated,which showed that Pp COL8 promoted sand pear fruit senescence.In contrast,the corresponding changes were the opposite in Pp MADS-overexpression sand pear fruits,suggesting that Pp MADS delayed sand pear fruit senescence.The co-transformation of Pp COL8 and Pp MADS also delayed sand pear fruit senescence.The results of this study revealed that Pp COL8 can play a key role in pear fruit senescence by interacting with Pp MADS through the SA signaling pathway.展开更多
Regulating planting density and nitrogen(N)fertilization could delay chlorophyll(Chl)degradation and leaf senescence in maize cultivars.This study measured changes in ear leaf green area(GLA_(ear)),Chl content,the act...Regulating planting density and nitrogen(N)fertilization could delay chlorophyll(Chl)degradation and leaf senescence in maize cultivars.This study measured changes in ear leaf green area(GLA_(ear)),Chl content,the activities of Chl a-degrading enzymes after silking,and the post-silking dry matter accumulation and grain yield under multiple planting densities and N fertilization rates.The dynamic change of GLA_(ear)after silking fitted to the logistic model,and the GLA_(ear) duration and the GLAearat 42 d after silking were affected mainly by the duration of the initial senescence period(T_(1))which was a key factor of the leaf senescence.The average chlorophyllase(CLH)activity was 8.3 times higher than pheophytinase activity and contributed most to the Chl content,indicating that CLH is a key enzyme for degrading Chl a in maize.Increasing density increased the CLH activity and decreased the Chl content,T1,GLAear,and GLA_(ear) duration.Under high density,appropriate N application reduced CLH activity,increased Chl content,prolonged T1,alleviated high-density-induced leaf senescence,and increased post-silking dry matter accumulation and grain yield.展开更多
Melatonin(MT)is a low molecular weight compound with multiple biological functions in plants.It is known to delay leaf senescence in various species.However,no data are available on the MT signaling pathway in posthar...Melatonin(MT)is a low molecular weight compound with multiple biological functions in plants.It is known to delay leaf senescence in various species.However,no data are available on the MT signaling pathway in postharvest vegetables.This study demonstrates that MT increases cGMP concentration and the expression of the cGMP synthesis gene BcGC1 in pak choi.The c GMP inhibitor LY83583 destroys effect of MT delaying the leaf senescence.LY83583 also prevents MT treatment from reducing the expression of chlorophyll metabolism-related genes(BcNYC1,BcNOL,BcPPH1/2,BcSGR1/2,and BcPAO)and senescence genes(BcSAG12 and BcSAG21).It also inhibits MT from reducing the activity of the key chlorophyll catabolism enzymes Mg-dechelatase,pheophytinase,and pheide a oxygenase.Thus,the ability of MT to maintain high levels of chlorophyll metabolites is also destroyed.The Arabidopsis c GMP synthetic gene mutant atgc1 was used to confirm that delayed leaf senescence caused by MT is mediated,at least in part,by the second messenger c GMP.展开更多
Citrus is the typical mycorrhizal fruit tree species establishing symbiosis with arbuscular mycorrhizal (AM) fungi. However, arbuscule development and senescence in colonized citrus roots, especially in response to dr...Citrus is the typical mycorrhizal fruit tree species establishing symbiosis with arbuscular mycorrhizal (AM) fungi. However, arbuscule development and senescence in colonized citrus roots, especially in response to drought stress, remain unclear, which is mainly due to the difficulty in clearing and staining lignified roots with the conventional method. Here, we improved the observation of colonized roots of citrus plants with the sectioning method, which enabled the clear observation of AM fungal structures. Furthermore, we investigated the effects of one week of drought stress on arbuscule development and senescence with the sectioning method. Microscopy observations indicated that drought stress significantly decreased mycorrhizal colonization (F%and M%) although it did not affect plant growth performance. Fluorescence probes (WGA 488 and/or Nile red) revealed that drought stress inhibited arbuscule development by increasing the percentage of arbuscules at the early stage and decreasing the percentages of arbuscules at the midterm and mature stages. Meanwhile, drought stress accelerated arbuscule senescence, which was characterized by the increased accumulation of neutral lipids. Overall, the sectioning method developed in this study enables the in-depth investigation of arbuscule status, and drought stress can inhibit arbuscule development but accelerate arbuscule senescence in the colonized roots of citrus plants. This study paves the way to elaborately dissecting the arbuscule dynamics in the roots of fruit tree species in response to diverse abiotic stresses.展开更多
Skeletal stem/progenitor cell(SSPC)senescence is a major cause of decreased bone regenerative potential with aging,but the causes of SSPC senescence remain unclear.In this study,we revealed that macrophages in calluse...Skeletal stem/progenitor cell(SSPC)senescence is a major cause of decreased bone regenerative potential with aging,but the causes of SSPC senescence remain unclear.In this study,we revealed that macrophages in calluses secrete prosenescent factors,including grancalcin(GCA),during aging,which triggers SSPC senescence and impairs fracture healing.Local injection of human rGCA in young mice induced SSPC senescence and delayed fracture repair.Genetic deletion of Gca in monocytes/macrophages was sufficient to rejuvenate fracture repair in aged mice and alleviate SSPC senescence.Mechanistically,GCA binds to the plexin-B2 receptor and activates Arg2-mediated mitochondrial dysfunction,resulting in cellular senescence.Depletion of Plxnb2 in SSPCs impaired fracture healing.Administration of GCA-neutralizing antibody enhanced fracture healing in aged mice.Thus,our study revealed that senescent macrophages within calluses secrete GCA to trigger SSPC secondary senescence,and GCA neutralization represents a promising therapy for nonunion or delayed union in elderly individuals.展开更多
Objective This study aimed to explore the association of single nucleotide polymorphisms(SNP)in the matrix metalloproteinase 2(MMP-2)signaling pathway and the risk of vascular senescence(VS).Methods In this cross-sect...Objective This study aimed to explore the association of single nucleotide polymorphisms(SNP)in the matrix metalloproteinase 2(MMP-2)signaling pathway and the risk of vascular senescence(VS).Methods In this cross-sectional study,between May and November 2022,peripheral venous blood of151 VS patients(case group)and 233 volunteers(control group)were collected.Fourteen SNPs were identified in five genes encoding the components of the MMP-2 signaling pathway,assessed through carotid-femoral pulse wave velocity(cf PWV),and analyzed using multivariate logistic regression.The multigene influence on the risk of VS was assessed using multifactor dimensionality reduction(MDR)and generalized multifactor dimensionality regression(GMDR)modeling.Results Within the multivariate logistic regression models,four SNPs were screened to have significant associations with VS:chemokine(C-C motif)ligand 2(CCL2)rs4586,MMP2 rs14070,MMP2rs7201,and MMP2 rs1053605.Carriers of the T/C genotype of MMP2 rs14070 had a 2.17-fold increased risk of developing VS compared with those of the C/C genotype,and those of the T/T genotype had a19.375-fold increased risk.CCL2 rs4586 and MMP-2 rs14070 exhibited the most significant interactions.Conclusion CCL2 rs4586,MMP-2 rs14070,MMP-2 rs7201,and MMP-2 rs1053605 polymorphisms were significantly associated with the risk of VS.展开更多
Hepatocellular carcinoma(HCC),a common malignancy worldwide,still lacks effective clinical treatment.The study aimed to investigate the oncogenes that affect the progression of HCC and their possible mechanisms.In our...Hepatocellular carcinoma(HCC),a common malignancy worldwide,still lacks effective clinical treatment.The study aimed to investigate the oncogenes that affect the progression of HCC and their possible mechanisms.In our study,we initially confirmed a higher level of PRDX2 in the bile of HCC patients compared to those with choledocholithiasis by 2-DE,LC-MS,and ELISA.Subsequently,we demonstrated the high expression of peroxiredoxin 2(PRDX2)in HCC based on the TCGA database and clinical sample analysis.Furthermore,PRDX2 overexpression enhanced the viability of HCC cells.And PRDX2 silencing induced senescence of HCC cells.In vivo,knockdown of PRDX2 significantly reduced the weight of xenograft tumors.PRDX2 also was found to activate the Wnt/β-catenin pathway by inducingβ-catenin nuclear translocation.Consequently,we proved that silencing PRDX2 could inhibit proliferation and Wnt/β-catenin pathway while promoting senescence in HCC cells.展开更多
Background:The primary cause of treatment failure in patients with refractory or relapsed B-cell non-Hodgkin lymphoma(r/r B-NHL)is resistance to current therapies,and therapy-induced senescence(TIS)stands out as a cru...Background:The primary cause of treatment failure in patients with refractory or relapsed B-cell non-Hodgkin lymphoma(r/r B-NHL)is resistance to current therapies,and therapy-induced senescence(TIS)stands out as a crucial mechanism contributing to tumor drug resistance.Here,we analyzed SENEX/Rho GTPase Activating Protein 18(ARHGAP18)expression and prognostic significance in doxorubicin-induced B-NHL-TIS model and r/r B-NHL patients,investigating its target in B-NHL cell senescence and the effect of combining specific inhibitors on apoptosis resistance in B-NHL-TIS cells.Methods:Raji cells were transfected with the human SENEX shRNA recombinant lentiviral vector(Sh-SENEX)and the empty vector negative(NC)to construct a stable transfection cell line with knockdown of SENEX.Effect of SENEX-silencing on B-NHL-TIS formation,cell function and cell cycle-related pathways was analyzed.Using doxorubicin(DOX)-inducible senescent B-NHL cells combined with the specific cyclin dependent kinase 4/6(CDK4/6)inhibitor Palbociclib to observe that blocking CDK4/6 effects on TIS formation.SENEX expression of 21 B-NHL patients and 8 healthy controls were analyzed by qRT-PCR,and the correlation between its expression and clinical indicators were evaluated.Results:The downregulation of SENEX expression promotes G1-S phase transition and apoptosis while inhibiting cell proliferation,collectively suppressing the formation of TIS in B-NHL.Blockade of CDK4/6 promotes the DOX-induced G1 phase arrest to enhance TIS formation in B-NHL cells which can reverse the regulatory effect of silencing SENEX on B-NHL cell cycle regulation and senescence.The expression levels of SENEX were notably elevated in B-NHL patients compared to healthy controls,and Elevated expression levels of SENEX were associated with poor prognosis of B-NHL patients.Conclusions:SENEX enhances apoptosis resistance in B-NHL by inhibiting CDK4/6,thereby preventing G1-S phase transition and promoting TIS formation.展开更多
Cellular senescence is a signal transduction process which maintained genomic stability and stopped mammalian cell growth. Furthermore, cellular senescence induces a protective response to a variety of DNA damage. How...Cellular senescence is a signal transduction process which maintained genomic stability and stopped mammalian cell growth. Furthermore, cellular senescence induces a protective response to a variety of DNA damage. However, this process is also associated with apoptosis, upregulated secretion of inflammatory cytokine, and promoted surrounding tissue damage. When cellular senescence accumulates to a certain extent, it triggers geriatric diseases, such as chronic inflammation, immune senescence-associated tumors and incontrollable infections. Cellular senescence gene SENEX, which was cloned in 2004, has been demonstrated to play a unique gatekeeper function in human endothelial cells when stress-induced pre-mature senescence and apoptosis occurr. The phenomenon that CD4+CD25+ Treg cells accumulated in the aged population has been well studied in recent years. Now Treg accumulation related to immune-pathology has attracted more interest. CD4+CD25+ Treg did not decline and age, but accumulated and suppressed immunoreaction. The enhanced Treg number and function may be associated with stress-induced premature senescence-mediated unique cellular senescence protection mechanisms, and SENEX may play a critical role in this process. In this article, we summarize the cellular senescence and SENEX gene in the accumulation and functional activity of CD4+CD25+ Treg in the elderly.展开更多
The increase in the frequency and intensity of drought events expected in the coming decades in Western Europe may disturb forest biogeochemical cycles and create nutrient deficiencies in trees.One possible origin of ...The increase in the frequency and intensity of drought events expected in the coming decades in Western Europe may disturb forest biogeochemical cycles and create nutrient deficiencies in trees.One possible origin of nutrient deficiency is the disturbance of the partitioning of the green leaf pool during the leaf senescence period between resorption,foliar leaching and senesced leaves.However,the effects of drought events on this partitioning and the consequences for the maintenance of tree nutrition are poorly documented.An experiment in a beech forest in Meuse(France)was conducted to assess the effect of drought events on nutrient canopy exchanges and on the partitioning of the green leaf pool during the leaf senescence period.The aim was to identify potential nutritional consequences of droughts for trees.Monitoring nutrient dynamics,including resorption,chemistry of green and senesced leaves,foliar absorption and leaching in mature beech stands from 2012 to 2019 allowed us to compare the nutrient exchanges for three nondry and three dry years(i.e.,with an intense drought event during the growing season).During dry years,we observed a decrease by almost a third of the potassium(K)partitioning to resorption(i.e.resorption efficiency),thus reducing the K reserve in trees for the next growing season.This result suggests that with the increased drought frequency and intensity expected for the coming decades,there will be a risk of potassium deficiency in trees,as already observed in a rainfall exclusion experiment on the same study site.Reduced foliar leaching and higher parititioning to the senesced leaves for K and phosphorus(P)were also observed.In addition,a slight increase in nitrogen(N)resorption efficiency occurred during dry years which is more likely to improve tree nutrition.The calcium(Ca)negative resorption decreased,with no apparent consequence in our study site.Our results show that nutrient exchanges in the canopy and the partitioning of the green leaf pool can be modified by drought events,and may have consequences on tree nutrition.展开更多
Objective:Organoids are a powerful tool with broad application prospects in biomedicine.Notably,they provide alternatives to animal models for testing potential drugs before clinical trials.However,the number of passa...Objective:Organoids are a powerful tool with broad application prospects in biomedicine.Notably,they provide alternatives to animal models for testing potential drugs before clinical trials.However,the number of passages for which organoids maintain cellular vitality ex vivo remains unclear.Methods:Herein,we constructed 55 gastric organoids from 35 individuals,serially passaged the organoids,and captured microscopic images for phenotypic evaluation.Senescence-associatedβ-galactosidase(SA-β-Gal),cell diameter in suspension,and gene expression reflecting cell cycle regulation were examined.The YOLOv3 object detection algorithm integrated with a convolutional block attention module(CBAM)was used to evaluate organoid vitality.Results:SA-β-Gal staining intensity;single-cell diameter;and expression of p15,p16,p21,CCNA2,CCNE2,and LMNB1 reflected the progression of aging in organoids during passaging.The CBAM-YOLOv3 algorithm precisely evaluated aging organoids on the basis of organoid average diameter,organoid number,and number×diameter,and the findings positively correlated with SA-β-Gal staining and single-cell diameter.Organoids derived from normal gastric mucosa had limited passaging ability(passages 1–5),before aging,whereas tumor organoids showed unlimited passaging potential for more than 45 passages(511 days)without showing clear senescence.Conclusions:Given the lack of indicators for evaluating organoid growth status,we established a reliable approach for integrated analysis of phenotypic parameters that uses an artificial intelligence algorithm to indicate organoid vitality.This method enables precise evaluation of organoid status in biomedical studies and monitoring of living biobanks.展开更多
Many studies have already shown that dwarfism and moderate delayed leaf senescence positively impact rice yield,but the underlying molecular mechanism of dwarfism and leaf senescence remains largely unknown.Here,using...Many studies have already shown that dwarfism and moderate delayed leaf senescence positively impact rice yield,but the underlying molecular mechanism of dwarfism and leaf senescence remains largely unknown.Here,using map-based cloning,we identified an allele of DEP2,DDG1,which controls plant height and leaf senescence in rice.The ddg1 mutant displayed dwarfism,short panicles,and delayed leaf senescence.Compared with the wild-type,ddg1 was insensitive to exogenous gibberellins(GA)and brassinolide(BR).DDG1 is expressed in various organs,especially in stems and panicles.Yeast two-hybrid assay,bimolecular fluorescent complementation and luciferase complementation image assay showed that DDG1 interacts with theα-subunit of the heterotrimeric G protein.Disruption of RGA1 resulted in dwarfism,short panicles,and darker-green leaves.Furthermore,we found that ddg1 and the RGA1 mutant was more sensitive to salt treatment,suggesting that DDG1 and RGA1 are involved in regulating salt stress response in rice.Our results show that DDG1/DEP2 regulates plant height and leaf senescence through interacting with RGA1.展开更多
Telomeres are nucleoprotein structures located at the end of each chromosome,which function in terminal protection and genomic stability.Telomeric damage is closely related to replicative senescence in vitro and physi...Telomeres are nucleoprotein structures located at the end of each chromosome,which function in terminal protection and genomic stability.Telomeric damage is closely related to replicative senescence in vitro and physical aging in vivo.As relatively long-lived mammals based on body size,bats display unique telomeric patterns,including the upregulation of genes involved in alternative lengthening of telomeres(ALT),DNA repair,and DNA replication.At present,however,the relevant molecular mechanisms remain unclear.In this study,we performed cross-species comparison and identified EPAS1,a well-defined oxygen response gene,as a key telomeric protector in bat fibroblasts.Bat fibroblasts showed high expression of EPAS1,which enhanced the transcription of shelterin components TRF1 and TRF2,as well as DNA repair factor RAD50,conferring bat fibroblasts with resistance to senescence during long-term consecutive expansion.Based on a human single-cell transcriptome atlas,we found that EPAS1 was predominantly expressed in the human pulmonary endothelial cell subpopulation.Using in vitro-cultured human pulmonary endothelial cells,we confirmed the functional and mechanistic conservation of EPAS1 in telomeric protection between bats and humans.In addition,the EPAS1 agonist M1001 was shown to be a protective compound against bleomycin-induced pulmonary telomeric damage and senescence.In conclusion,we identified a potential mechanism for regulating telomere stability in human pulmonary diseases associated with aging,drawing insights from the longevity of bats.展开更多
Objective To investigate the fate and underlying mechanisms of G2 phase arrest in cancer cells elicited by ionizing radiation(IR).Methods Human melanoma A375 and 92-1 cells were treated with X-rays radiation or Aurora...Objective To investigate the fate and underlying mechanisms of G2 phase arrest in cancer cells elicited by ionizing radiation(IR).Methods Human melanoma A375 and 92-1 cells were treated with X-rays radiation or Aurora A inhibitor MLN8237(MLN)and/or p21 depletion by small interfering RNA(si RNA).Cell cycle distribution was determined using flow cytometry and a fluorescent ubiquitin-based cell cycle indicator(FUCCI)system combined with histone H3 phosphorylation at Ser10(p S10 H3)detection.Senescence was assessed using senescence-associated-β-galactosidase(SA-β-Gal),Ki67,andγH2AX staining.Protein expression levels were determined using western blotting.Results Tumor cells suffered severe DNA damage and underwent G2 arrest after IR treatment.The damaged cells did not successfully enter M phase nor were they stably blocked at G2 phase but underwent mitotic skipping and entered G1 phase as tetraploid cells,ultimately leading to senescence in G1.During this process,the p53/p21 pathway is hyperactivated.Accompanying p21 accumulation,Aurora A kinase levels declined sharply.MLN treatment confirmed that Aurora A kinase activity is essential for mitosis skipping and senescence induction.Conclusion Persistent p21 activation during IR-induced G2 phase blockade drives Aurora A kinase degradation,leading to senescence via mitotic skipping.展开更多
Pear fruit senescence under high-and low-temperature conditions has been reported to be mediated by microRNAs.Long non-coding RNAs(lncRNAs),which can function as competing endogenous RNAs that interact with microRNAs,...Pear fruit senescence under high-and low-temperature conditions has been reported to be mediated by microRNAs.Long non-coding RNAs(lncRNAs),which can function as competing endogenous RNAs that interact with microRNAs,may also be involved in temperature-affected fruit senescence.Based on the transcriptome and microRNA sequencings,in this study,3330 lncRNAs were isolated from Pyrus pyrifolia fruit.Of these lncRNAs,2060 and 537 were responsive to high-and low-temperature conditions,respectively.Of these differentially expressed lncRNAs,82 and 24 correlated to the mRNAs involved in fruit senescence under high-and low-temperature conditions,respectively.Moreover,three lncRNAs were predicted to be competing endogenous RNAs(ceRNAs)that interact with the microRNAs involved in fruit senescence,while one and two ceRNAs were involved in fruit senescence under high-and low-temperature conditions,respectively.A dual-luciferase assay showed that the interaction of an lncRNA with a microRNA disrupts the action of the microRNA on the expression of its target mRNA(s).Furthermore,four alternative splicing-derived lncRNAs interacted with miR172i homologies(Novel_88 and Novel_69)to relieve the repressed expression of their target and produce an miR172i precursor.Correlation analysis of microRNA expression suggested that Novel_69 is likely involved in the cleavage of the pre-miR172i hairpin to generate mature miR172i.Taken together,lncRNAs are involved in pear fruit senescence under high-or low-temperature conditions through ceRNAs and the production of microRNA.展开更多
Objective Kidney renal clear cell carcinoma(KIRC)is a common renal malignancy that has a poor prognosis.As a member of the F box family,cyclin F(CCNF)plays an important regulatory role in normal tissues and tumors.How...Objective Kidney renal clear cell carcinoma(KIRC)is a common renal malignancy that has a poor prognosis.As a member of the F box family,cyclin F(CCNF)plays an important regulatory role in normal tissues and tumors.However,the underlying mechanism by which CCNF promotes KIRC proliferation still remains unclear.Methods Bioinformatics methods were used to analyze The Cancer Genome Atlas(TCGA)database to obtain gene expression and clinical prognosis data.The CCK8 assay,EdU assay,and xenograft assay were used to detect cell proliferation.The cell senescence and potential mechanism were assessed by SA-β-gal staining,Western blotting,as well as ELISA.Results Our data showed that CCNF was highly expressed in KIRC patients.Meanwhile,downregulation of CCNF inhibited cell proliferation in vivo and in vitro.Further studies showed that the reduction of CCNF promoted cell senescence by decreasing cyclin-dependent kinase 1(CDK1),increasing the proinflammatory factors interleukin(IL)-6 and IL-8,and then enhancing the expression of p21 and p53.Conclusion We propose that the high expression of CCNF in KIRC may play a key role in tumorigenesis by regulating cell senescence.Therefore,CCNF shows promise as a new biomarker to predict the clinical prognosis of KIRC patients and as an effective therapeutic target.展开更多
Flower senescence is commonly enhanced by the endogenous hormone ethylene and suppressed by the gibberellins(GAs)in plants.However,the detailed mechanisms for the antagonism of these hormones during f lower senescence...Flower senescence is commonly enhanced by the endogenous hormone ethylene and suppressed by the gibberellins(GAs)in plants.However,the detailed mechanisms for the antagonism of these hormones during f lower senescence remain elusive.In this study,we characterized one up-regulated gene PhOBF1,belonging to the basic leucine zipper transcription factor family,in senescing petals of petunia(Petunia hybrida).Exogenous treatments with ethylene and GA3 provoked a dramatic increase in PhOBF1 transcripts.Compared with wild-type plants,PhOBF1-RNAi transgenic petunia plants exhibited shortened f lower longevity,while overexpression of PhOBF1 resulted in delayed flower senescence.Transcript abundances of two senescence-related genes PhSAG12 and PhSAG29 were higher in PhOBF1-silenced plants but lower in PhOBF1-overexpressing plants.Silencing and overexpression of PhOBF1 affected expression levels of a few genes involved in the GA biosynthesis and signaling pathways,as well as accumulation levels of bioactive GAs GA1 and GA3.Application of GA3 restored the accelerated petal senescence to normal levels in PhOBF1-RNAi transgenic petunia lines,and reduced ethylene release and transcription of three ethylene biosynthetic genes PhACO1,PhACS1,and PhACS2.Moreover,PhOBF1 was observed to specifically bind to the PhGA20ox3 promoter containing a G-box motif.Transient silencing of PhGA20ox3 in petunia plants through tobacco rattle virus-based virus-induced gene silencing method led to accelerated corolla senescence.Our results suggest that PhOBF1 functions as a negative regulator of ethylene-mediated f lower senescence by modulating the GA production.展开更多
BACKGROUND Cellular senescence,a state of stable growth arrest,is intertwined with human cancers.However,characterization of cellular senescence-associated phenotypes in hepatocellular carcinoma(HCC)remains unexplored...BACKGROUND Cellular senescence,a state of stable growth arrest,is intertwined with human cancers.However,characterization of cellular senescence-associated phenotypes in hepatocellular carcinoma(HCC)remains unexplored.AIM To address this issue,we delineated cellular senescence landscape across HCC.METHODS We enrolled two HCC datasets,TCGA-LIHC and International Cancer Genome Consortium(ICGC).Unsupervised clustering was executed to probe tumor heterogeneity based upon cellular senescence genes.Least absolute shrinkage and selection operator algorithm were utilized to define a cellular senescence-relevant scoring system.TRNP1 expression was measured in HCCs and normal tissues through immunohistochemistry,immunoblotting and quantitative real-time polymerase chain reaction.The influence of TMF-regulated nuclear protein(TRNP)1 on HCC senescence and growth was proven via a series of experiments.RESULTS TCGA-LIHC patients were classified as three cellular senescence subtypes,named C1–3.The robustness and reproducibility of these subtypes were proven in the ICGC cohort.C2 had the worst overall survival,C1 the next,and C3 the best.C2 presented the highest levels of immune checkpoints,abundance of immune cells,and immunogenetic indicators.Thus,C2 might possibly respond to immunotherapy.C2 had the lowest somatic mutation rate,while C1 presented the highest copy number variations.A cellular senescence-relevant gene signature was generated,which can predict patient survival,and chemo-or immunotherapeutic response.Experimentally,it was proven that TRNP1 presented the remarkable upregulation in HCCs.TRNP1 knockdown induced apoptosis and senescence of HCC cells and attenuated tumor growth.CONCLUSION These findings provide a systematic framework for assessing cellular senescence in HCC,which decode the tumor heterogeneity and tailor the pharmacological interventions to improve clinical management.展开更多
BACKGROUND Intervertebral disc degeneration(IDD)is a main contributor to low back pain.Oxidative stress,which is highly associated with the progression of IDD,increases senescence of nucleus pulposus-derived mesenchym...BACKGROUND Intervertebral disc degeneration(IDD)is a main contributor to low back pain.Oxidative stress,which is highly associated with the progression of IDD,increases senescence of nucleus pulposus-derived mesenchymal stem cells(NPMSCs)and weakens the differentiation ability of NPMSCs in degenerated intervertebral discs(IVDs).Quercetin(Que)has been demonstrated to reduce oxidative stress in diverse degenerative diseases.AIM To investigate the role of Que in oxidative stress-induced NPMSC damage and to elucidate the underlying mechanism.METHODS In vitro,NPMSCs were isolated from rat tails.Senescence-associatedβ-galactosidase(SA-β-Gal)staining,cell cycle,reactive oxygen species(ROS),realtime quantitative polymerase chain reaction(RT-qPCR),immunofluorescence,and western blot analyses were used to evaluated the protective effects of Que.Meanwhile the relationship between miR-34a-5p and Sirtuins 1(SIRT1)was evaluated by dual-luciferase reporter assay.To explore whether Que modulates tert-butyl hydroperoxide(TBHP)-induced senescence of NPMSCs via the miR-34a-5p/SIRT1 pathway,we used adenovirus vectors to overexpress and downregulate the expression of miR-34a-5p and used SIRT1 siRNA to knockdown SIRT1 expression.In vivo,a puncture-induced rat IDD model was constructed,and X rays and histological analysis were used to assess whether Que could alleviate IDD in vivo.RESULTS We found that TBHP can cause NPMSCs senescence changes,such as reduced cell proliferation ability,increased SA-β-Gal activity,cell cycle arrest,the accumulation of ROS,and increased expression of senescence-related proteins.While abovementioned senescence indicators were significantly alleviated by Que treatment.Que decreased the expression levels of senescence-related proteins(p16,p21,and p53)and senescence-associated secreted phenotype(SASP),including IL-1β,IL-6,and MMP-13,and it increased the expression of SIRT1.In addition,the protective effects of Que on cell senescence were partially reversed by miR-34a-5p overexpression and SIRT1 knockdown.In vivo,X-ray,and histological analyses indicated that Que alleviated IDD in a punctureinduced rat model.CONCLUSION In summary,the present study provides evidence that Que reduces oxidative stress-induced senescence of NPMSCs via the miR-34a/SIRT1 signaling pathway,suggesting that Que may be a potential agent for the treatment of IDD.展开更多
Objective:To investigate whether human short interspersed nuclear element antisense RNA(Alu antisense RNA;Alu asRNA)could delay human fibroblast senescence and explore the underlying mechanisms.Methods:We transfected ...Objective:To investigate whether human short interspersed nuclear element antisense RNA(Alu antisense RNA;Alu asRNA)could delay human fibroblast senescence and explore the underlying mechanisms.Methods:We transfected Alu asRNA into senescent human fibroblasts and used cell counting kit-8(CCK-8),reactive oxygen species(ROS),and senescence-associated beta-galactosidase(SA-β-gal)staining methods to analyze the anti-aging effects of Alu asRNA on the fibroblasts.We also used an RNA-sequencing(RNA-seq)method to investigate the Alu asRNA-specific mechanisms of anti-aging.We examined the effects of KIF15 on the anti-aging role induced by Alu asRNA.We also investigated the mechanisms underlying a KIF15-induced proliferation of senescent human fibroblasts.Results:The CCK-8,ROS and SA-β-gal results showed that Alu asRNA could delay fibroblast aging.RNA-seq showed 183 differentially expressed genes(DEGs)in Alu asRNA transfected fibroblasts compared with fibroblasts transfected with the calcium phosphate transfection(CPT)reagent.The KEGG analysis showed that the cell cycle pathway was significantly enriched in the DEGs in fibroblasts transfected with Alu asRNA compared with fibroblasts transfected with the CPT reagent.Notably,Alu asRNA promoted the KIF15 expression and activated the MEK-ERK signaling pathway.Conclusion:Our results suggest that Alu asRNA could promote senescent fibroblast proliferation via activation of the KIF15-mediated MEK-ERK signaling pathway.展开更多
基金supported by the National Natural Science Foundation of China(32272654)the Natural Science Foundation of Hebei Province China(C2023204016)+2 种基金the Hebei Province Introduced Overseas-Scholar Fund China(C20220361)the S&T Program of Hebei China(20326330D)the Hebei Province Outstanding Youth Fund China(2016,2019)。
文摘Pyrus pyrifolia Nakai‘Whangkeumbae'is a sand pear fruit with excellent nutritional quality and taste.However,the industrial development of pear fruit is significantly limited by its short shelf life.Salicylic acid(SA),a well-known phytohormone,can delay fruit senescence and improve shelf life.However,the mechanism by which SA regulates CONSTANS-LIKE genes(COLs)during fruit senescence and the role of COL genes in mediating fruit senescence in sand pear are poorly understood.In this study,22 COL genes were identified in sand pear,including four COLs(Pp COL8,Pp COL9a,Pp COL9b,and Pp COL14)identified via transcriptome analysis and 18 COLs through genome-wide analysis.These COL genes were divided into three subgroups according to the structural domains of the COL protein.Pp COL8,with two B-box motifs and one CCT domain,belonged to the first subgroup.In contrast,the other three Pp COLs,Pp COL9a,Pp COL9b,and Pp COL14,with similar conserved protein domains and gene structures,were assigned to the third subgroup.The four COLs showed different expression patterns in pear tissues and were preferentially expressed at the early stage of fruit development.Moreover,the expression of Pp COL8 was inhibited by exogenous SA treatment,while SA up-regulated the expression of Pp COL9a and Pp COL9b.Interestingly,Pp COL8 interacts with Pp MADS,a MADS-box protein preferentially expressed in fruit,and SA up-regulated its expression.While the production of ethylene and the content of malondialdehyde(MDA)were increased in Pp COL8-overexpression sand pear fruit,the antioxidant enzyme(POD and SOD)activity and the expression of Pp POD1 and Pp SOD1 in the sand pear fruits were down-regulated,which showed that Pp COL8 promoted sand pear fruit senescence.In contrast,the corresponding changes were the opposite in Pp MADS-overexpression sand pear fruits,suggesting that Pp MADS delayed sand pear fruit senescence.The co-transformation of Pp COL8 and Pp MADS also delayed sand pear fruit senescence.The results of this study revealed that Pp COL8 can play a key role in pear fruit senescence by interacting with Pp MADS through the SA signaling pathway.
基金financially supported by the National Key Research and Development Program of China(2022YFD190160304)Natural Science Foundation of Sichuan Province(2022NSFSC0013)+1 种基金Sichuan Maize Innovation Team Construction Project(SCCXTD-2022-02)National Key Research and Development Program of China(2018YFD0301206)。
文摘Regulating planting density and nitrogen(N)fertilization could delay chlorophyll(Chl)degradation and leaf senescence in maize cultivars.This study measured changes in ear leaf green area(GLA_(ear)),Chl content,the activities of Chl a-degrading enzymes after silking,and the post-silking dry matter accumulation and grain yield under multiple planting densities and N fertilization rates.The dynamic change of GLA_(ear)after silking fitted to the logistic model,and the GLA_(ear) duration and the GLAearat 42 d after silking were affected mainly by the duration of the initial senescence period(T_(1))which was a key factor of the leaf senescence.The average chlorophyllase(CLH)activity was 8.3 times higher than pheophytinase activity and contributed most to the Chl content,indicating that CLH is a key enzyme for degrading Chl a in maize.Increasing density increased the CLH activity and decreased the Chl content,T1,GLAear,and GLA_(ear) duration.Under high density,appropriate N application reduced CLH activity,increased Chl content,prolonged T1,alleviated high-density-induced leaf senescence,and increased post-silking dry matter accumulation and grain yield.
基金supported by the National Natural Science Foundation of China(Grant No.32001451)Jiangsu Agriculture Science and Technology Innovation Fund[Grant No.CX(20)1008]。
文摘Melatonin(MT)is a low molecular weight compound with multiple biological functions in plants.It is known to delay leaf senescence in various species.However,no data are available on the MT signaling pathway in postharvest vegetables.This study demonstrates that MT increases cGMP concentration and the expression of the cGMP synthesis gene BcGC1 in pak choi.The c GMP inhibitor LY83583 destroys effect of MT delaying the leaf senescence.LY83583 also prevents MT treatment from reducing the expression of chlorophyll metabolism-related genes(BcNYC1,BcNOL,BcPPH1/2,BcSGR1/2,and BcPAO)and senescence genes(BcSAG12 and BcSAG21).It also inhibits MT from reducing the activity of the key chlorophyll catabolism enzymes Mg-dechelatase,pheophytinase,and pheide a oxygenase.Thus,the ability of MT to maintain high levels of chlorophyll metabolites is also destroyed.The Arabidopsis c GMP synthetic gene mutant atgc1 was used to confirm that delayed leaf senescence caused by MT is mediated,at least in part,by the second messenger c GMP.
基金supported by grants from the Natural Science Foundation of China (Grant No.42077040)the open competition program of top ten critical priorities of Agricultural Science and Technology Innovation for the 14th Five-Year Plan of Guangdong Province (Grant Nos.2022SDZG09,2023SDZG09)+1 种基金the Natural Science Foundation of Guangdong (Grant No.2021B1515010868)the GDAS Project of Science and Technology Development(2021GDASYL-20210103023)。
文摘Citrus is the typical mycorrhizal fruit tree species establishing symbiosis with arbuscular mycorrhizal (AM) fungi. However, arbuscule development and senescence in colonized citrus roots, especially in response to drought stress, remain unclear, which is mainly due to the difficulty in clearing and staining lignified roots with the conventional method. Here, we improved the observation of colonized roots of citrus plants with the sectioning method, which enabled the clear observation of AM fungal structures. Furthermore, we investigated the effects of one week of drought stress on arbuscule development and senescence with the sectioning method. Microscopy observations indicated that drought stress significantly decreased mycorrhizal colonization (F%and M%) although it did not affect plant growth performance. Fluorescence probes (WGA 488 and/or Nile red) revealed that drought stress inhibited arbuscule development by increasing the percentage of arbuscules at the early stage and decreasing the percentages of arbuscules at the midterm and mature stages. Meanwhile, drought stress accelerated arbuscule senescence, which was characterized by the increased accumulation of neutral lipids. Overall, the sectioning method developed in this study enables the in-depth investigation of arbuscule status, and drought stress can inhibit arbuscule development but accelerate arbuscule senescence in the colonized roots of citrus plants. This study paves the way to elaborately dissecting the arbuscule dynamics in the roots of fruit tree species in response to diverse abiotic stresses.
基金This work was supported by the National Key R&D Program of China(Project No.2019YFA0111900 to C.J.L.and Y.J.,2022YFC3601900 to G.H.L.,2022YFC3601903 to X.H.L.,and 2022YFC3601905)the National Natural Science Foundation of China(Grant Nos.82261160397,82272560,81922017 to C.J.L.and 81930022,91749105 to X.H.L.)+3 种基金the NSFC/RGC Joint Research Scheme,the Research Grants Council(UGC)of the Hong Kong Special Administrative Region and the National Natural Science Foundation of China(NSFC/RGC Project No.N_CUHK483/22 to Y.J.)the Hunan Provincial Science and Technology Department(2023JJ30896 to C.J.L.)the Key Research and Development Program of Hunan Province(2022SK2023 to C.J.L.)the Science and Technology Innovation Program of Hunan Province(2023RC1027 to C.J.L.,2022RC1009 to J.W,and 2022RC3075 to C.Z.).
文摘Skeletal stem/progenitor cell(SSPC)senescence is a major cause of decreased bone regenerative potential with aging,but the causes of SSPC senescence remain unclear.In this study,we revealed that macrophages in calluses secrete prosenescent factors,including grancalcin(GCA),during aging,which triggers SSPC senescence and impairs fracture healing.Local injection of human rGCA in young mice induced SSPC senescence and delayed fracture repair.Genetic deletion of Gca in monocytes/macrophages was sufficient to rejuvenate fracture repair in aged mice and alleviate SSPC senescence.Mechanistically,GCA binds to the plexin-B2 receptor and activates Arg2-mediated mitochondrial dysfunction,resulting in cellular senescence.Depletion of Plxnb2 in SSPCs impaired fracture healing.Administration of GCA-neutralizing antibody enhanced fracture healing in aged mice.Thus,our study revealed that senescent macrophages within calluses secrete GCA to trigger SSPC secondary senescence,and GCA neutralization represents a promising therapy for nonunion or delayed union in elderly individuals.
基金supported by the Construction of Prevention and Treatment System of Geriatric Syndromes Focusing on Disability and Dementia(No.21-1-2-2-zyyd-nsh)。
文摘Objective This study aimed to explore the association of single nucleotide polymorphisms(SNP)in the matrix metalloproteinase 2(MMP-2)signaling pathway and the risk of vascular senescence(VS).Methods In this cross-sectional study,between May and November 2022,peripheral venous blood of151 VS patients(case group)and 233 volunteers(control group)were collected.Fourteen SNPs were identified in five genes encoding the components of the MMP-2 signaling pathway,assessed through carotid-femoral pulse wave velocity(cf PWV),and analyzed using multivariate logistic regression.The multigene influence on the risk of VS was assessed using multifactor dimensionality reduction(MDR)and generalized multifactor dimensionality regression(GMDR)modeling.Results Within the multivariate logistic regression models,four SNPs were screened to have significant associations with VS:chemokine(C-C motif)ligand 2(CCL2)rs4586,MMP2 rs14070,MMP2rs7201,and MMP2 rs1053605.Carriers of the T/C genotype of MMP2 rs14070 had a 2.17-fold increased risk of developing VS compared with those of the C/C genotype,and those of the T/T genotype had a19.375-fold increased risk.CCL2 rs4586 and MMP-2 rs14070 exhibited the most significant interactions.Conclusion CCL2 rs4586,MMP-2 rs14070,MMP-2 rs7201,and MMP-2 rs1053605 polymorphisms were significantly associated with the risk of VS.
基金National Nature Science Foundation of China(Nos.81960118,81860115,81760116 and 82060116)Guizhou Science and Technology Project:Qiankehe Foundation(No.(2020)1Y300)+8 种基金Natural Science Foundation of Sichuan(No.2022NSFSC0837)Science and Technology Project of Chengdu(No.2022-YF05-01811-SN)Science and Technology Project of Guizhou Province(No.YQK(2023)032)Guizhou Medical University Doctoral Start-Up Fund(No.gyfybsky-2021-27)Guizhou Medical University Doctoral Start-Up Fund(No.gyfybsky-2021-26)Guizhou Science and Technology Department(No.(2019)1259)Guizhou Science and Technology Department Guizhou Science and Technology Platform Talents(No.(2017)5718)Science and Technology Fund of Guizhou Provincial Health Commission(No.gzwki2021-382)The Affiliated Hospital of Guizhou Medical University Excellent Reserve Talent in 2023(No.gyfyxkrc-2023-06).
文摘Hepatocellular carcinoma(HCC),a common malignancy worldwide,still lacks effective clinical treatment.The study aimed to investigate the oncogenes that affect the progression of HCC and their possible mechanisms.In our study,we initially confirmed a higher level of PRDX2 in the bile of HCC patients compared to those with choledocholithiasis by 2-DE,LC-MS,and ELISA.Subsequently,we demonstrated the high expression of peroxiredoxin 2(PRDX2)in HCC based on the TCGA database and clinical sample analysis.Furthermore,PRDX2 overexpression enhanced the viability of HCC cells.And PRDX2 silencing induced senescence of HCC cells.In vivo,knockdown of PRDX2 significantly reduced the weight of xenograft tumors.PRDX2 also was found to activate the Wnt/β-catenin pathway by inducingβ-catenin nuclear translocation.Consequently,we proved that silencing PRDX2 could inhibit proliferation and Wnt/β-catenin pathway while promoting senescence in HCC cells.
基金This work was supported by the Major Subject of Science and Technology of Anhui Province(Grant Number:201903a07020030).
文摘Background:The primary cause of treatment failure in patients with refractory or relapsed B-cell non-Hodgkin lymphoma(r/r B-NHL)is resistance to current therapies,and therapy-induced senescence(TIS)stands out as a crucial mechanism contributing to tumor drug resistance.Here,we analyzed SENEX/Rho GTPase Activating Protein 18(ARHGAP18)expression and prognostic significance in doxorubicin-induced B-NHL-TIS model and r/r B-NHL patients,investigating its target in B-NHL cell senescence and the effect of combining specific inhibitors on apoptosis resistance in B-NHL-TIS cells.Methods:Raji cells were transfected with the human SENEX shRNA recombinant lentiviral vector(Sh-SENEX)and the empty vector negative(NC)to construct a stable transfection cell line with knockdown of SENEX.Effect of SENEX-silencing on B-NHL-TIS formation,cell function and cell cycle-related pathways was analyzed.Using doxorubicin(DOX)-inducible senescent B-NHL cells combined with the specific cyclin dependent kinase 4/6(CDK4/6)inhibitor Palbociclib to observe that blocking CDK4/6 effects on TIS formation.SENEX expression of 21 B-NHL patients and 8 healthy controls were analyzed by qRT-PCR,and the correlation between its expression and clinical indicators were evaluated.Results:The downregulation of SENEX expression promotes G1-S phase transition and apoptosis while inhibiting cell proliferation,collectively suppressing the formation of TIS in B-NHL.Blockade of CDK4/6 promotes the DOX-induced G1 phase arrest to enhance TIS formation in B-NHL cells which can reverse the regulatory effect of silencing SENEX on B-NHL cell cycle regulation and senescence.The expression levels of SENEX were notably elevated in B-NHL patients compared to healthy controls,and Elevated expression levels of SENEX were associated with poor prognosis of B-NHL patients.Conclusions:SENEX enhances apoptosis resistance in B-NHL by inhibiting CDK4/6,thereby preventing G1-S phase transition and promoting TIS formation.
文摘Cellular senescence is a signal transduction process which maintained genomic stability and stopped mammalian cell growth. Furthermore, cellular senescence induces a protective response to a variety of DNA damage. However, this process is also associated with apoptosis, upregulated secretion of inflammatory cytokine, and promoted surrounding tissue damage. When cellular senescence accumulates to a certain extent, it triggers geriatric diseases, such as chronic inflammation, immune senescence-associated tumors and incontrollable infections. Cellular senescence gene SENEX, which was cloned in 2004, has been demonstrated to play a unique gatekeeper function in human endothelial cells when stress-induced pre-mature senescence and apoptosis occurr. The phenomenon that CD4+CD25+ Treg cells accumulated in the aged population has been well studied in recent years. Now Treg accumulation related to immune-pathology has attracted more interest. CD4+CD25+ Treg did not decline and age, but accumulated and suppressed immunoreaction. The enhanced Treg number and function may be associated with stress-induced premature senescence-mediated unique cellular senescence protection mechanisms, and SENEX may play a critical role in this process. In this article, we summarize the cellular senescence and SENEX gene in the accumulation and functional activity of CD4+CD25+ Treg in the elderly.
基金supported by the Lorraine University of Excellence via the DEEPSURF project(ANR 70315-IDEX-04-LUE)。
文摘The increase in the frequency and intensity of drought events expected in the coming decades in Western Europe may disturb forest biogeochemical cycles and create nutrient deficiencies in trees.One possible origin of nutrient deficiency is the disturbance of the partitioning of the green leaf pool during the leaf senescence period between resorption,foliar leaching and senesced leaves.However,the effects of drought events on this partitioning and the consequences for the maintenance of tree nutrition are poorly documented.An experiment in a beech forest in Meuse(France)was conducted to assess the effect of drought events on nutrient canopy exchanges and on the partitioning of the green leaf pool during the leaf senescence period.The aim was to identify potential nutritional consequences of droughts for trees.Monitoring nutrient dynamics,including resorption,chemistry of green and senesced leaves,foliar absorption and leaching in mature beech stands from 2012 to 2019 allowed us to compare the nutrient exchanges for three nondry and three dry years(i.e.,with an intense drought event during the growing season).During dry years,we observed a decrease by almost a third of the potassium(K)partitioning to resorption(i.e.resorption efficiency),thus reducing the K reserve in trees for the next growing season.This result suggests that with the increased drought frequency and intensity expected for the coming decades,there will be a risk of potassium deficiency in trees,as already observed in a rainfall exclusion experiment on the same study site.Reduced foliar leaching and higher parititioning to the senesced leaves for K and phosphorus(P)were also observed.In addition,a slight increase in nitrogen(N)resorption efficiency occurred during dry years which is more likely to improve tree nutrition.The calcium(Ca)negative resorption decreased,with no apparent consequence in our study site.Our results show that nutrient exchanges in the canopy and the partitioning of the green leaf pool can be modified by drought events,and may have consequences on tree nutrition.
基金supported by grants from the National Natural Science Foundation of China(Grant Nos.82072602 and 82173222)the Science and Technology Commission of Shanghai Municipality(Grant Nos.20DZ2201900 and 18411953100)+1 种基金the Innovation Foundation of Translational Medicine of Shanghai Jiaotong University School of Medicine(Grant No.TM202001)the Collaborative Innovation Center for Clinical and Translational Science of the Chinese Ministry of Education&Shanghai(Grant No.CCTS-2022202)。
文摘Objective:Organoids are a powerful tool with broad application prospects in biomedicine.Notably,they provide alternatives to animal models for testing potential drugs before clinical trials.However,the number of passages for which organoids maintain cellular vitality ex vivo remains unclear.Methods:Herein,we constructed 55 gastric organoids from 35 individuals,serially passaged the organoids,and captured microscopic images for phenotypic evaluation.Senescence-associatedβ-galactosidase(SA-β-Gal),cell diameter in suspension,and gene expression reflecting cell cycle regulation were examined.The YOLOv3 object detection algorithm integrated with a convolutional block attention module(CBAM)was used to evaluate organoid vitality.Results:SA-β-Gal staining intensity;single-cell diameter;and expression of p15,p16,p21,CCNA2,CCNE2,and LMNB1 reflected the progression of aging in organoids during passaging.The CBAM-YOLOv3 algorithm precisely evaluated aging organoids on the basis of organoid average diameter,organoid number,and number×diameter,and the findings positively correlated with SA-β-Gal staining and single-cell diameter.Organoids derived from normal gastric mucosa had limited passaging ability(passages 1–5),before aging,whereas tumor organoids showed unlimited passaging potential for more than 45 passages(511 days)without showing clear senescence.Conclusions:Given the lack of indicators for evaluating organoid growth status,we established a reliable approach for integrated analysis of phenotypic parameters that uses an artificial intelligence algorithm to indicate organoid vitality.This method enables precise evaluation of organoid status in biomedical studies and monitoring of living biobanks.
基金supported by the Program for Huaishang Talents,Huai’an Academy of Agricultural Sciences Initiation and Development of Scientific Research Fund for High-Level Introduced Talents(0062019016B)Jiangsu Collaborative Innovation Center of Regional Modern Agriculture&Environmental Protection(HSXT30133)+1 种基金the Jiangsu Qinglan Project,the Hunan Province Natural Science Fund(2019JJ50714)the Student Innovation Program of Jinagsu Province(202110323084Y,202210323029Z).
文摘Many studies have already shown that dwarfism and moderate delayed leaf senescence positively impact rice yield,but the underlying molecular mechanism of dwarfism and leaf senescence remains largely unknown.Here,using map-based cloning,we identified an allele of DEP2,DDG1,which controls plant height and leaf senescence in rice.The ddg1 mutant displayed dwarfism,short panicles,and delayed leaf senescence.Compared with the wild-type,ddg1 was insensitive to exogenous gibberellins(GA)and brassinolide(BR).DDG1 is expressed in various organs,especially in stems and panicles.Yeast two-hybrid assay,bimolecular fluorescent complementation and luciferase complementation image assay showed that DDG1 interacts with theα-subunit of the heterotrimeric G protein.Disruption of RGA1 resulted in dwarfism,short panicles,and darker-green leaves.Furthermore,we found that ddg1 and the RGA1 mutant was more sensitive to salt treatment,suggesting that DDG1 and RGA1 are involved in regulating salt stress response in rice.Our results show that DDG1/DEP2 regulates plant height and leaf senescence through interacting with RGA1.
基金supported by the Applied Basic Research Programs of Science and Technology Commission Foundation of Yunnan Province(202201AS070044)National Key Research&Developmental Program of China(2021YFA0805701)+1 种基金Chinese Academy of Sciences(CAS)“Light of West China”Program(xbzg-zdsys-202113)Kunming Science and Technology Bureau(2022SCP007)。
文摘Telomeres are nucleoprotein structures located at the end of each chromosome,which function in terminal protection and genomic stability.Telomeric damage is closely related to replicative senescence in vitro and physical aging in vivo.As relatively long-lived mammals based on body size,bats display unique telomeric patterns,including the upregulation of genes involved in alternative lengthening of telomeres(ALT),DNA repair,and DNA replication.At present,however,the relevant molecular mechanisms remain unclear.In this study,we performed cross-species comparison and identified EPAS1,a well-defined oxygen response gene,as a key telomeric protector in bat fibroblasts.Bat fibroblasts showed high expression of EPAS1,which enhanced the transcription of shelterin components TRF1 and TRF2,as well as DNA repair factor RAD50,conferring bat fibroblasts with resistance to senescence during long-term consecutive expansion.Based on a human single-cell transcriptome atlas,we found that EPAS1 was predominantly expressed in the human pulmonary endothelial cell subpopulation.Using in vitro-cultured human pulmonary endothelial cells,we confirmed the functional and mechanistic conservation of EPAS1 in telomeric protection between bats and humans.In addition,the EPAS1 agonist M1001 was shown to be a protective compound against bleomycin-induced pulmonary telomeric damage and senescence.In conclusion,we identified a potential mechanism for regulating telomere stability in human pulmonary diseases associated with aging,drawing insights from the longevity of bats.
基金supported by the Science and Technology Research Project of Gansu Province[20JR5RA555 and145RTSA012]the Natural Science Foundation of Shaanxi Province[2020JQ-541]+1 种基金the National Natural Science Foundation of China[31870851 and 12175289]the Youth Innovation Promotion Association CAS[2021415]
文摘Objective To investigate the fate and underlying mechanisms of G2 phase arrest in cancer cells elicited by ionizing radiation(IR).Methods Human melanoma A375 and 92-1 cells were treated with X-rays radiation or Aurora A inhibitor MLN8237(MLN)and/or p21 depletion by small interfering RNA(si RNA).Cell cycle distribution was determined using flow cytometry and a fluorescent ubiquitin-based cell cycle indicator(FUCCI)system combined with histone H3 phosphorylation at Ser10(p S10 H3)detection.Senescence was assessed using senescence-associated-β-galactosidase(SA-β-Gal),Ki67,andγH2AX staining.Protein expression levels were determined using western blotting.Results Tumor cells suffered severe DNA damage and underwent G2 arrest after IR treatment.The damaged cells did not successfully enter M phase nor were they stably blocked at G2 phase but underwent mitotic skipping and entered G1 phase as tetraploid cells,ultimately leading to senescence in G1.During this process,the p53/p21 pathway is hyperactivated.Accompanying p21 accumulation,Aurora A kinase levels declined sharply.MLN treatment confirmed that Aurora A kinase activity is essential for mitosis skipping and senescence induction.Conclusion Persistent p21 activation during IR-induced G2 phase blockade drives Aurora A kinase degradation,leading to senescence via mitotic skipping.
基金supported by the Fundamental Research Funds for the Central Universities(Grant No.KYYJ202116)the Jiangsu Agricultural Science and Technology Innovation Fund[Grant No.CX(20)2020]the Earmarked Fund for China Agriculture Research System(Grant No.CARS-28).
文摘Pear fruit senescence under high-and low-temperature conditions has been reported to be mediated by microRNAs.Long non-coding RNAs(lncRNAs),which can function as competing endogenous RNAs that interact with microRNAs,may also be involved in temperature-affected fruit senescence.Based on the transcriptome and microRNA sequencings,in this study,3330 lncRNAs were isolated from Pyrus pyrifolia fruit.Of these lncRNAs,2060 and 537 were responsive to high-and low-temperature conditions,respectively.Of these differentially expressed lncRNAs,82 and 24 correlated to the mRNAs involved in fruit senescence under high-and low-temperature conditions,respectively.Moreover,three lncRNAs were predicted to be competing endogenous RNAs(ceRNAs)that interact with the microRNAs involved in fruit senescence,while one and two ceRNAs were involved in fruit senescence under high-and low-temperature conditions,respectively.A dual-luciferase assay showed that the interaction of an lncRNA with a microRNA disrupts the action of the microRNA on the expression of its target mRNA(s).Furthermore,four alternative splicing-derived lncRNAs interacted with miR172i homologies(Novel_88 and Novel_69)to relieve the repressed expression of their target and produce an miR172i precursor.Correlation analysis of microRNA expression suggested that Novel_69 is likely involved in the cleavage of the pre-miR172i hairpin to generate mature miR172i.Taken together,lncRNAs are involved in pear fruit senescence under high-or low-temperature conditions through ceRNAs and the production of microRNA.
基金supported by the National Natural Science Foundation of China(No.81874148 and No.82203142).
文摘Objective Kidney renal clear cell carcinoma(KIRC)is a common renal malignancy that has a poor prognosis.As a member of the F box family,cyclin F(CCNF)plays an important regulatory role in normal tissues and tumors.However,the underlying mechanism by which CCNF promotes KIRC proliferation still remains unclear.Methods Bioinformatics methods were used to analyze The Cancer Genome Atlas(TCGA)database to obtain gene expression and clinical prognosis data.The CCK8 assay,EdU assay,and xenograft assay were used to detect cell proliferation.The cell senescence and potential mechanism were assessed by SA-β-gal staining,Western blotting,as well as ELISA.Results Our data showed that CCNF was highly expressed in KIRC patients.Meanwhile,downregulation of CCNF inhibited cell proliferation in vivo and in vitro.Further studies showed that the reduction of CCNF promoted cell senescence by decreasing cyclin-dependent kinase 1(CDK1),increasing the proinflammatory factors interleukin(IL)-6 and IL-8,and then enhancing the expression of p21 and p53.Conclusion We propose that the high expression of CCNF in KIRC may play a key role in tumorigenesis by regulating cell senescence.Therefore,CCNF shows promise as a new biomarker to predict the clinical prognosis of KIRC patients and as an effective therapeutic target.
基金funded by the National Natural Science Foundation of China(Grant no.32271953 and 31801895)Postdoctoral Special Funding Project of China(Grant no.2019T120958)the Basic Scientific Research Expense of Northwest A&F University(Grant no.Z1090322159).
文摘Flower senescence is commonly enhanced by the endogenous hormone ethylene and suppressed by the gibberellins(GAs)in plants.However,the detailed mechanisms for the antagonism of these hormones during f lower senescence remain elusive.In this study,we characterized one up-regulated gene PhOBF1,belonging to the basic leucine zipper transcription factor family,in senescing petals of petunia(Petunia hybrida).Exogenous treatments with ethylene and GA3 provoked a dramatic increase in PhOBF1 transcripts.Compared with wild-type plants,PhOBF1-RNAi transgenic petunia plants exhibited shortened f lower longevity,while overexpression of PhOBF1 resulted in delayed flower senescence.Transcript abundances of two senescence-related genes PhSAG12 and PhSAG29 were higher in PhOBF1-silenced plants but lower in PhOBF1-overexpressing plants.Silencing and overexpression of PhOBF1 affected expression levels of a few genes involved in the GA biosynthesis and signaling pathways,as well as accumulation levels of bioactive GAs GA1 and GA3.Application of GA3 restored the accelerated petal senescence to normal levels in PhOBF1-RNAi transgenic petunia lines,and reduced ethylene release and transcription of three ethylene biosynthetic genes PhACO1,PhACS1,and PhACS2.Moreover,PhOBF1 was observed to specifically bind to the PhGA20ox3 promoter containing a G-box motif.Transient silencing of PhGA20ox3 in petunia plants through tobacco rattle virus-based virus-induced gene silencing method led to accelerated corolla senescence.Our results suggest that PhOBF1 functions as a negative regulator of ethylene-mediated f lower senescence by modulating the GA production.
文摘BACKGROUND Cellular senescence,a state of stable growth arrest,is intertwined with human cancers.However,characterization of cellular senescence-associated phenotypes in hepatocellular carcinoma(HCC)remains unexplored.AIM To address this issue,we delineated cellular senescence landscape across HCC.METHODS We enrolled two HCC datasets,TCGA-LIHC and International Cancer Genome Consortium(ICGC).Unsupervised clustering was executed to probe tumor heterogeneity based upon cellular senescence genes.Least absolute shrinkage and selection operator algorithm were utilized to define a cellular senescence-relevant scoring system.TRNP1 expression was measured in HCCs and normal tissues through immunohistochemistry,immunoblotting and quantitative real-time polymerase chain reaction.The influence of TMF-regulated nuclear protein(TRNP)1 on HCC senescence and growth was proven via a series of experiments.RESULTS TCGA-LIHC patients were classified as three cellular senescence subtypes,named C1–3.The robustness and reproducibility of these subtypes were proven in the ICGC cohort.C2 had the worst overall survival,C1 the next,and C3 the best.C2 presented the highest levels of immune checkpoints,abundance of immune cells,and immunogenetic indicators.Thus,C2 might possibly respond to immunotherapy.C2 had the lowest somatic mutation rate,while C1 presented the highest copy number variations.A cellular senescence-relevant gene signature was generated,which can predict patient survival,and chemo-or immunotherapeutic response.Experimentally,it was proven that TRNP1 presented the remarkable upregulation in HCCs.TRNP1 knockdown induced apoptosis and senescence of HCC cells and attenuated tumor growth.CONCLUSION These findings provide a systematic framework for assessing cellular senescence in HCC,which decode the tumor heterogeneity and tailor the pharmacological interventions to improve clinical management.
基金Supported by the National Natural Science Foundation of China,No.82172462,No.81972136the Traditional Chinese Medicine Science and Technology Development Plan Project of Jiangsu Province,No.YB2020085Cross Cooperation Project of Northern Jiangsu People’s Hospital,No.SBJC21014.
文摘BACKGROUND Intervertebral disc degeneration(IDD)is a main contributor to low back pain.Oxidative stress,which is highly associated with the progression of IDD,increases senescence of nucleus pulposus-derived mesenchymal stem cells(NPMSCs)and weakens the differentiation ability of NPMSCs in degenerated intervertebral discs(IVDs).Quercetin(Que)has been demonstrated to reduce oxidative stress in diverse degenerative diseases.AIM To investigate the role of Que in oxidative stress-induced NPMSC damage and to elucidate the underlying mechanism.METHODS In vitro,NPMSCs were isolated from rat tails.Senescence-associatedβ-galactosidase(SA-β-Gal)staining,cell cycle,reactive oxygen species(ROS),realtime quantitative polymerase chain reaction(RT-qPCR),immunofluorescence,and western blot analyses were used to evaluated the protective effects of Que.Meanwhile the relationship between miR-34a-5p and Sirtuins 1(SIRT1)was evaluated by dual-luciferase reporter assay.To explore whether Que modulates tert-butyl hydroperoxide(TBHP)-induced senescence of NPMSCs via the miR-34a-5p/SIRT1 pathway,we used adenovirus vectors to overexpress and downregulate the expression of miR-34a-5p and used SIRT1 siRNA to knockdown SIRT1 expression.In vivo,a puncture-induced rat IDD model was constructed,and X rays and histological analysis were used to assess whether Que could alleviate IDD in vivo.RESULTS We found that TBHP can cause NPMSCs senescence changes,such as reduced cell proliferation ability,increased SA-β-Gal activity,cell cycle arrest,the accumulation of ROS,and increased expression of senescence-related proteins.While abovementioned senescence indicators were significantly alleviated by Que treatment.Que decreased the expression levels of senescence-related proteins(p16,p21,and p53)and senescence-associated secreted phenotype(SASP),including IL-1β,IL-6,and MMP-13,and it increased the expression of SIRT1.In addition,the protective effects of Que on cell senescence were partially reversed by miR-34a-5p overexpression and SIRT1 knockdown.In vivo,X-ray,and histological analyses indicated that Que alleviated IDD in a punctureinduced rat model.CONCLUSION In summary,the present study provides evidence that Que reduces oxidative stress-induced senescence of NPMSCs via the miR-34a/SIRT1 signaling pathway,suggesting that Que may be a potential agent for the treatment of IDD.
基金supported by grants from the National Natural Science Foundation of China(No.81771499)and the Natural Science Foundation of Hebei Province,China(No.H2018206099 and No.H2021206460).
文摘Objective:To investigate whether human short interspersed nuclear element antisense RNA(Alu antisense RNA;Alu asRNA)could delay human fibroblast senescence and explore the underlying mechanisms.Methods:We transfected Alu asRNA into senescent human fibroblasts and used cell counting kit-8(CCK-8),reactive oxygen species(ROS),and senescence-associated beta-galactosidase(SA-β-gal)staining methods to analyze the anti-aging effects of Alu asRNA on the fibroblasts.We also used an RNA-sequencing(RNA-seq)method to investigate the Alu asRNA-specific mechanisms of anti-aging.We examined the effects of KIF15 on the anti-aging role induced by Alu asRNA.We also investigated the mechanisms underlying a KIF15-induced proliferation of senescent human fibroblasts.Results:The CCK-8,ROS and SA-β-gal results showed that Alu asRNA could delay fibroblast aging.RNA-seq showed 183 differentially expressed genes(DEGs)in Alu asRNA transfected fibroblasts compared with fibroblasts transfected with the calcium phosphate transfection(CPT)reagent.The KEGG analysis showed that the cell cycle pathway was significantly enriched in the DEGs in fibroblasts transfected with Alu asRNA compared with fibroblasts transfected with the CPT reagent.Notably,Alu asRNA promoted the KIF15 expression and activated the MEK-ERK signaling pathway.Conclusion:Our results suggest that Alu asRNA could promote senescent fibroblast proliferation via activation of the KIF15-mediated MEK-ERK signaling pathway.
