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SUMMARY: Aging is an inevitable biological process that affects the function of all organs, including the adrenal gland, which is essential for producing steroid hormones that regulate metabolism, stress response, and immune activation. Understanding how aging affects the morphology of this gland is crucial to developing interventions to mitigate its adverse effects. Thus, this study aimed to describe the morphoquantitative alterations of the adrenal gland in senescent Sprague Dawley rats compared to adult rats. Twelve male rats were divided into 6 adult rats aged 6 months (group A) and 6 senescent rats aged 36 months (group S). Histopathological studies, quantification of collagen fibers types I and III, and stereological analysis were performed to determine the volume density (Vv), surface area (Sv), and number (Nv) of the nuclei of the zona fasciculata cells. Adrenal gland tissue from group S presented dysplasia, metaplasia, intracellular fat accumulation, fibrosis, blood vessel dilation, and increased presence of apoptotic cells. Capsule thickening and increased collagen type I were also observed. There was a significant decrease in Vv, Sv, and Nv of zona fasciculata nuclei in group S compared to group A. The results indicate that aging induces significant morphoquantitative changes in the adrenal gland, which could contribute to the decrease in glucocorticoid production and alterations in aldosterone and cortisol secretion observed in senescence. Understanding these alterations is crucial to developing interventions that mitigate the adverse effects of aging on the endocrine system.
El envejecimiento es un proceso biológico inevitable que afecta la función de todos los órganos, incluida la glándula suprarrenal, fundamental para la producción de hormonas esteroides que regulan el metabolismo, la respuesta al estrés y la activación inmunológica. Comprender cómo el envejecimiento afecta la morfología de esta glándula es crucial para desarrollar intervenciones que mitiguen sus efectos adversos. Así, el objetivo de este estudio fue describir las alteraciones morfocuantitativas de la glándula suprarrenal en ratas Sprague Dawley senescentes comparadas con ratas adultas. Se utilizaron 12 ratas macho, divididas en dos grupos: 6 ratas adultas de 6 meses de edad (grupo A) y 6 ratas senescentes de 36 meses de edad (grupo S). Se realizaron estudios histopatológicos, cuantificación de fibras de colágeno tipos I y III y análisis estereológicos para determinar la densidad de volumen (Vv), de superficie (Sv) y de número (Nv) de los núcleos de las células de la zona fasciculada. El tejido de la glándula suprarrenal del grupo S presentó displasia, metaplasia, acumulación de grasa intracelular, fibrosis, dilatación de vasos sanguíneos y mayor presencia de células apoptósicas. También se observó un engrosamiento de la cápsula y un incremento del colágeno tipo I. Hubo una disminución significativa en Vv, Sv y Nv de los núcleos de la zona fasciculada en el grupo S en comparación con el grupo A. Los resultados indican que el envejecimiento induce cambios morfocuantitativos significativos en la glándula suprarrenal, lo que podría contribuir a la disminución en la producción de glucocorticoides y alteraciones en la secreción de aldosterona y cortisol observadas en la senescencia. Comprender estas alteraciones es crucial para desarrollar intervenciones que mitiguen los efectos adversos del envejecimiento en el sistema endocrino.
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Innate immune system activation is crucial in the inflammatory response, but uncontrolled activation can lead to autoimmune diseases. Cellular exhaustion and senescence are two processes that contribute to innate immune tolerance breakdown. Exhausted immune cells are unable to respond adequately to specific antigens or stimuli, while senescent cells have impaired DNA replication and metabolic changes. These processes can impair immune system function and disrupt homeostasis, leading to the emergence of autoimmunity. However, the influence of innate immune exhaustion and senescence on autoimmune disorders is not well understood. This review aims to describe the current findings on the role of innate immune exhaustion and senescence in autoimmunity, focusing on the cellular and molecular changes involved in each process. Specifically, the article explores the markers and pathways associated with immune exhaustion, such as PD-1 and TIM-3, and senescence, including Β-galactosidase (β-GAL), lamin B1, and p16ink4a, and their impact on autoimmune diseases, namely type 1 diabetes, rheumatoid arthritis, systemic lupus erythematosus, and immune-mediated myopathies. Understanding the mechanisms underlying innate immune exhaustion and senescence in autoimmunity may provide insights for the development of novel therapeutic strategies.
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<b>Objective</b> To evaluate the effect of glycogen synthase kinase 3β (GSK3β) on hypoxia/reoxygenation (H/R)-induced injury of senescent renal tubular epithelial cell (RTEC) in aged mice and its regulatory mechanism. <b>Methods</b> RTEC were divided into the Young group (young RTEC with normal growth), Old group (aged RTEC induced by Etoposide), Old+Ad-shNC+H/R group [aged RTEC induced by Etoposide and then transfected with adenovirus negative control (Ad-shNC) for H/R treatment], and Old+Ad-shGSK3β+H/R group (aged RTEC induced by Etoposide and then transfected with short-hairpin RNA-expressing adenovirus with targeted silencing GSK3β for H/R treatment), respectively. Apoptosis level and mitochondrial reactive oxygen species level were detected by flow cytometry. Calcium ion level was determined by immunofluorescence staining. The expression and phosphorylation levels of GSK3β, mitochondria-associated endoplasmic reticulum membrane (MAM)-related proteins of inositol 1,4,5-trisphosphate receptor1 (ITPR1), voltage dependent anion-selective channel 1(VDAC1) and glucose-regulated protein 75 (GRP75) were detected by Western blot. The interaction between GSK3β and MAM-related proteins was analyzed by immunoprecipitation. <b>Results</b> Compared with the Young group, the apoptosis, mitochondrial reactive oxygen species and mitochondrial calcium ion levels were higher in the Old group. Compared with the Old group, the apoptosis, mitochondrial reactive oxygen species and mitochondrial calcium ion levels were higher in the Old+Ad-shNC+H/R group. Compared with the Old+Ad-shNC+H/R group, the apoptosis, mitochondrial reactive oxygen species and mitochondrial calcium ion levels were lower in the Old+Ad-shGSK3β+H/R group, and the differences were statistically significant (all <i>P</i><0.05). Compared with the Young group, the expression levels of ITPR1, GRP75 and GSK3β proteins were up-regulated, the phosphorylation levels of ITPR1 and GRP75 were increased, whereas the total protein and phosphorylation levels of VDAC1 were decreased in the Old group. Compared with the Old group, the expression level of GSK3β protein was unchanged, the total protein and phosphorylation levels of ITPR1 and GRP75 were increased, the expression level of total VDAC1 protein remained unchanged and the phosphorylation level was increased in the Old+Ad-shNC+H/R group. Compared with the Old+Ad-shNC+H/R group, the expression level of GSK3β protein was decreased, the expression levels of total ITPR1, GRP75 and VDAC1 proteins were unchanged, whereas the phosphorylation levels were decreased in the Old+Ad-shGSK3β+H/R group. Immunoprecipitation showed that GSK3β could interact with ITPR1, GRP75 and VDAC1 proteins. <b>Conclusions</b> The expression level of GSK3β is up-regulated in senescent RTEC. Down-regulating GSK3β expression may reduce the phosphorylation level of ITPR1-GRP75-VDAC1 complex, constrain the overload of mitochondrial calcium ion, protect mitochondrial function and mitigate cell damage during reperfusion.
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Objective To explore the differentially expressed mRNAs and related biological processes and pathways in fractional low-dose ionizing radiation (LDIR)-induced senescence of normal human bronchial epithelial (HBE) cells by high-throughput mRNA sequencing and bioinformatics techniques. Methods Senescence-associated β-galactosidase staining and senescence-associated secretion phenotype gene mRNA and protein expression levels were measured at 24 and 48 h after irradiating HBE cells 7 times at doses of 0, 50, 100, and 200 mGy, respectively. The differentially expressed genes were screened by high-throughput sequencing for Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses. Results The senescence-positive area of fractional low-dose irradiated HBE cells increased in a dose-dependent manner (P < 0.05). The mRNA levels and protein expression of transforming growth factor-β1(TGF-β1) and matrix metalloproteinase-9(MMP-9) genes were increased in the 100 mGy × 7 and 200 mGy × 7 groups at 24 and 48 h after the end of irradiation compared with the control group. High-throughput sequencing showed that there were 882, 475, and 1205 differentially expressed mRNAs in each dose group compared with the control group. GO analysis showed that the differentially expressed mRNAs in each dose group were mainly enriched in biological processes such as cell cycle regulation, regulation of nitrogen compound metabolic process, regulation of cell division and response to stimulus. KEGG analysis showed that the differentially expressed mRNAs were mainly enriched in the pathways of cell cycle, cell senescence, and ferroptosis. Conclusion Fractional LDIR induced senescence in HBE cells, and differentially expressed mRNA-associated biological processes and pathways in senescent cells are related to cell cycle and cell senescence.
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ObjectiveTo observe the effect of Shengxiantang （SXT） on cell senescence mediated by wingless/integrated （Wnt）3a/β-catenin pathway in rats with idiopathic pulmonary fibrosis （IPF） and reveal the possible mechanism in improving lung function of IPF rats. MethodA total of 32 SPF level SD rats were randomly divided into sham group， model group， pirfenidone group， and SXT group. The IPF rat model was established by intratracheal instillation of bleomycin （0.005 g·kg-1）. The following day after surgery， rats in the SXT group were given the aqueous solution of SXT granules （0.78 g·kg-1）， and the pirfenidone group was given pirfenidone suspension （0.05 g·kg-1）. The other groups were given deionized water （10 mL·kg-1） for 28 consecutive days. Lung tissue was collected after the lung function was measured. The pathological changes of the lung tissue were observed by hematoxylin-eosin （HE） and Masson staining， and then the Szapiel score and Ashcroft score were performed. Real-time fluorescence quantitative polymerase chain reaction （Real-time PCR） was used to detect telomere length. Western blot was applied to detect the expressions of epithelial-mesenchymal transformation （EMT） markers ［α-smooth muscle actin （α-SMA） and E-cadherin］， telomere reverse transcriptase （TRET）， aging-related proteins （p53 and p21）， senescence-associated secretory phenotype ［interleukin-6 （IL-6） and matrix metalloproteinase-1 （MMP-1）］， and key proteins of Wnt signaling pathway ［Wnt3a， glycogen synthase kinase-3β （GSK-3β）， β-catenin， Cyclin D1， and c-Myc］. ResultCompared with those in the Sham group， peak expiratory flow （PEF） and minute ventilation volume （MV） in the model group were significantly decreased （P<0.01）， and the frequency of respiratory （f） was significantly increased （P<0.01）. The Szapiel score， Ashcroft score， and protein expression of α-SMA， p53， p21， IL-6， MMP-1， Wnt3a， GSK3β， β-catenin， Cyclin D1， and c-Myc were increased （P<0.01）. The expressions of E-cadherin and TERT， as well as telomere length were significantly decreased （P<0.01）. Compared with those in the model group， PEF and MV in the SXT group were significantly increased （P<0.01）， while f was significantly decreased （P<0.01）. The Szapiel score， Ashcroft score， and protein expression of α-SMA， p53， p21， IL-6， MMP-1， Wnt3a， GSK3β， β-catenin， Cyclin D1， and c-Myc were significantly decreased （P<0.05， P<0.01）. Nevertheless， the expression of E-cadherin and TERT， as well as telomere length were significantly increased （P<0.01）. ConclusionSXT presents a significant protective effect on lung function in IPF rats， and the prescription may act on the Wnt3a/β-catenin signaling pathway to regulate cell senescence induced by TERT to inhibit EMT.
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ObjectiveThe lung mesenchymal stem cells （LMSCs） induced by D-galactose （D-gal） were intervened by Wenfei Huaxian decoction-containing serum to explore the mechanism of Wenfei Huaxian decoction in delaying the senescence of LMSCs through the nicotinamide phosphoribosyltransferase/silent information regulator 1 （NAMPT/SIRT1） signaling pathway. MethodWenfei Huaxian decoction-containing serum was prepared. LMSCs were isolated by gradient density centrifugation， and they were cultured and identified in vitro. The senescence model in vitro was established by stimulating cells via D-gal for 24 h. LMSCs cells were modeled after being treated with different volume fractions （5%， 10%， 20%， 40%， and 80%） of Wenfei Huaxian decoction-containing serum for 24 h， and the cell proliferation level was detected by methyl thiazolyl tetrazolium （MTT） method. The cells were randomly divided into blank serum group， model group， and high， medium， and low dose groups of Wenfei Huaxian decoction-containing serum. Senescence-associated β-galactosidase （SA-β-gal） staining was used to detect the senescence of LMSCs in each group. The content of NAD + was detected by colorimetry. The levels of senescence-associated factors （p16 and p53）， interleukin-6 （IL-6）， and tumor necrosis factor-α （TNF-α） in cell culture supernatant were detected by enzyme-linked immunosorbent assay （ELISA）. Western blot was used to detect the relative expression of senescence-associated proteins and NAMPT/SIRT1 signaling pathway-related proteins. ResultCompared with the blank serum group， the proliferation of LMSCs was significantly inhibited after D-gal stimulation for 24 h （P<0.01）. Compared with the model group， the proliferation of LMSCs could be promoted after intervention with the corresponding Wenfei Huaxian decoction-containing serum （P<0.05， P<0.01）. Compared with the blank serum group， the SA-β-gal staining of LMSCs in the model group after D-gal stimulation was enhanced， and the content of NAD+ was increased （P<0.01）. The expression levels of senescence factors p16 and p53， as well as SASP pro-inflammatory factors IL-6 and TNF-α in the cell culture supernatant， were significantly increased （P<0.01）. The expression of senescence-associated proteins p16， p21， and p53 increased （P<0.01）， and the protein expression of NAMPT， SIRT1， peroxisome proliferator-activated receptor γ coactivator 1α （PGC-1α）， and forkhead box family transcription factor O1 （FoxO1） decreased （P<0.01）. Compared with the model group， the SA-β-gal staining of LMSCs in each group of Wenfei Huaxian decoction-containing serum was significantly reduced， and the content of NAD+ was decreased （P<0.01）. The senescence factors （p16 and p53） and inflammatory factors （IL-6 and TNF-α） in the cell culture supernatant were significantly decreased （P<0.01）. The expression of senescence-associated proteins （P16， P21， and P53） decreased （P<0.05， P<0.01）. The protein expressions of NAMPT， SIRT1， PGC-1α， and FoxO1 were significantly up-regulated （P<0.05， P<0.01）. ConclusionWenfei Huaxian decoction can alleviate senescence and inflammatory response damage of D-gal-induced LMSCs， and its mechanism may be related to the regulation of the NAMPT/SIRT1 signaling pathway.
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Objective To investigate the role of KAT7 in cartilage cell and tissue ageing by establishing an over-replicating-induced primary mouse cartilage cell ageing model and a mouse natural ageing model.Methods Chon-drocytes of the mouse knee joint were obtained by type Ⅱ collagenase digestion and identified by toluidine blue stai-ning and Col Ⅱ staining.The age-related proteins and KAT7 expression levels in cartilage cells from different gener-ations of mice were discovered using Western blot and cellular immunofluorescence techniques,and the aging of the cells was assessed by SA-β-Gal coloring.The pathological alterations were examined in the joints of 22-month-old mice compared to 2-month-old mice using HE staining and safranin O-solid green staining.Additionally,immuno-histochemical analysis was done to observe the expression of KAT7 and p53 in mouse joint tissue.Results Com-pared with the control group,the expression levels of KAT7 protein and p21 and p53 in aged mouse chondrocytes significantly increased.WM-3835,a commonly inhibitor of KAT7 that possess the capacity on halting the protein expression procedure of gene KAT7 as well as p21 in ageing chondrocytes.SA-β-Gal staining showed a significant increase in positive staining of chondrocytes in the eighth generation(P8)compared to the first generation(P1).Compared with the cartilage tissue of young mice,the cartilage tissue of elderly mice presents a near-bone distribu-tion,with a decrease in cartilage surface integrity,a significant increase in the number of hypertrophic chondro-cytes,and more KAT7 and p53 cells that were positive.Conclusion The expression of KAT7 increases in the ageing chondrocytes and the cartilage tissue of ageing mice,reveales the potential significance of KAT7 correlated to cellular aging process in cartilage.
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Age-related macular degeneration(AMD)is a serious threat to the visual health of the elderly,and the dysfunction of retinal pigment epithelial cells(RPE)is a significant etiology risk.Aging process leads to RPE repli-cation senescence,and some environment factors like light exposure and cigarette exposure may lead to RPE stress premature aging,and the decreased lysosomal digestion ability of senescent RPE cells may lead to the accumulation of lipofuscin,triggering the occurrence of early AMD.A series of homeostatic imbalances in aging retina,such as cell senescence-renewal imbalance,oxidative stress-antioxidant imbalance,chronic inflammatory-anti-inflammatory imbalance,intestinal barrier and intestinal microbiota imbalance and pro-angiogenesis-antiangiogenic imbalance all contribute to the development of AMD.
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Objective To study the effective fraction and mechanism of Lycium barbarum leaves on improving learning and memory ability of subacute aging mice induced by D-galactose injection.Methods The model of subacute aging mice was developed by injection of D-galactose subcutaneously,and different extracts of Lycium barbarum leaves were prepared.The effects of the extracts of Lycium barbarum leaves on the learning and memory ability of model mice were evaluated by Y maze experiment and new object recognition experiment.The pathomorphological changes of hippocampus in mice were observed by hematoxylin-eosin and Nissl staining.The levels of brain-derived neurotrophic factor(BDNF),nerve growth factor(NGF),glial cell line-derived neurotrophic factor(GDNF),tumor necrosis factor-α(TNF-α),interleukin-1β(IL-1β),interferon-γ(IFN-γ)and interleukin-10(IL-10)in hippocampus of mice were detected by enzyme-linked immunosorbent assay.The activities of superoxide dismutase(SOD)and the contents of glutathione(GSH)and malondialdehyde(MDA)in hippocampus of mice were detected by related assay kits.Detection of apoptosis in the hippocampal region of mouse brain tissue using the TUNEL method.Western blotting analysis was used to detect the expressions of antioxidant proteins Nrf2,HO-1 and apoptotic proteins Caspase-3,Caspase-9 in hippocampus of mice.Results The water extraction part and 80%alcohol precipitation supernatant part of Lycium barbarum leaves significantly improved the learning and memory ability of model mice,improved the pathological damage of hippocampus in mice,increased the number of Nissl bodies in hippocampus of mice,and promoted the expression of neurotrophic factors BDNF,NGF and GDNF,and promoted the expression of neurotrophic factors BDNF,NGF and GDNF.Pro-inflammatory factors TNF-α,IL-1β and IFN-γ expression declines while anti-inflammatory factor IL-10 expression rises.The activity of SOD and the expression of GSH were increased,and the expression of MDA was decreased.Increase the expression of Nrf2 and HO-1 antioxidant proteins;reduce the expression of Caspase-3 and Caspase-9 apoptosis pathway proteins.Inhibition of apoptosis in the hippocampal region of mouse brain tissue using a model.Conclusion The water extracts and 80%alcohol precipitation supernatant extracts of Lycium barbarum leaves are the effective fractions of Lycium barbarum leaves to improve the learning and memory ability of D-galactose-induced subacute aging mice,and its mechanism might be related to the inhibition of neuronal apoptosis caused by oxidative stress and inflammation.
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BACKGROUND:Cadmium is a common environmental pollutant,which can damage multiple organs and tissues,such as the kidney and bone,but its effect on annulus fibrosus cells in the intervertebral disc has been less reported. OBJECTIVE:To investigate the effect of cadmium chloride on the senescence of annulus fibrosus cells and the role of PI3K/Akt signaling pathway. METHODS:Annulus fibrosus cells from Sprague-Dawley rat intervertebral discs were harvested and passage 3 cells were intervened with different concentrations of cadmium chloride(0,1,5,10,20 μmol/L).Cell viability and proliferation were detected by cell counting kit-8 assay.Transcriptome sequencing and Kyoto Encyclopedia of Genes and Genomes functional enrichment analysis were performed on annulus fibrosus cells with or without cadmium chloride addition.Passage 3 annulus fibrosus cells were divided into control group,cadmium chloride group and LY294002 group.Cell proliferation rate was detected by EdU method,positive cell rate was detected by senescence-associated β-galactosidase staining,and expressions of senescence-associated proteins(p16,p21 and p53)and p-Akt at protein and mRNA levels were measured by western blot,RT-PCR and immunofluorescence. RESULTS AND CONCLUSION:5 μmol/L cadmium chloride could inhibit the proliferation of annulus fibrosus cells.Results from the Kyoto Encyclopedia of Genes and Genomes functional enrichment analysis showed that the main signal transduction pathways included PI3K/Akt,cell cycle and p53 signaling pathways,which were related to cell senescence and proliferation.PI3K/Akt signaling pathways with significant differential expression were selected for validation.Compared with the control group,the EdU-positive rate was significantly decreased in the cadmium chloride group(P<0.05),while the β-galactosidase-positive rate,the expression of senescence-associated proteins(p16,p21 and p53)and p-Akt significantly increased(P<0.05).Compared with the cadmium chloride group,the EdU-positive rate and p-Akt expression were significantly decreased in the LY294002 group(P<0.05),while the β-galactosidase-positive rate and the expression of senescence-associated proteins(p16,p21 and p53)significantly increased(P<0.05).To conclude,cadmium chloride can regulate the senescence of annulus fibrosus cells by activating the PI3K/Akt signaling pathway,thereby inducing the occurrence and progression of intervertebral disc degeneration.
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BACKGROUND:Wnt signaling pathway is overexpressed in degenerative intervertebral discs,and inhibition of its expression can delay the process of intervertebral disc degeneration.Therefore,Wnt signaling pathway is closely related to intervertebral disc degeneration. OBJECTIVE:To summarize the relationship between Wnt signaling pathway and intervertebral disc,especially the specific role and influence of Wnt signaling pathway in intervertebral disc degeneration. METHODS:The first author took"intervertebral disc,Wnt,cell proliferation,cell senescence,cell apoptosis,extracellular matrix"as the English search terms.PubMed,Web of science and OVID LWWSpringerlink were searched for articles published from 2000 to January 2023,and articles related to Wnt signaling pathway and disc degeneration were consulted.Totally 54 articles were reviewed by reading,collating and preserving. RESULTS AND CONCLUSION:(1)During intervertebral disc formation in embryos,Wnt signaling pathway is overexpressed,which is involved in intervertebral disc formation and promotes posterior extension of notochord.(2)During intervertebral disc degeneration,Wnt signaling pathway can inhibit cell proliferation by stagnating cell cycle,increase the expression of age-related proteins and promote cell aging by participating in oxidative stress,and participate in cell apoptosis by regulation of long non-coding RNA.(3)Wnt signaling pathway can also decrease extracellular matrix related protein synthesis,promote extracellular matrix degradation and accelerate intervertebral disc degeneration.(4)Wnt signaling pathway can promote cell regeneration by activating as early intervertebral disc formation signal and participate in inducing stem cells to differentiate into intervertebral disc cells to repair damaged intervertebral disc.For example,Wnt signaling pathway can induce stem cells from cartilage endplate cells to migrate and transform to intervertebral disc.
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BACKGROUND:Diabetic osteoporosis is gaining public attention.However,few studies have reported the effect of a high-glucose environment on the osteogenic differentiation of human umbilical cord mesenchymal stem cells and the corresponding therapeutic strategies. OBJECTIVE:To investigate whether vitamin D3 can restore the osteogenic differentiation potential of human umbilical cord mesenchymal stem cells in a high-glucose environment. METHODS:The viability of human umbilical cord mesenchymal stem cells was detected by CCK-8 assay to screen the appropriate vitamin D3 intervention concentration.Under the high-glucose environment,RT-qPCR,western blot assay,immunofluorescence,JC-1 mitochondrial membrane potential,alizarin red staining,and β-galactosidase staining were used to evaluate the osteogenic differentiation potential,intracellular reactive oxygen species accumulation,mitochondrial membrane potential alteration,and cell senescence of human umbilical cord mesenchymal stem cells after vitamin D3 intervention.The underlying mechanism was also discussed. RESULTS AND CONCLUSION:(1)Vitamin D3 significantly promoted the proliferation of human umbilical cord mesenchymal stem cells in the range of 0.1 μmol/L to 1 mmol/L.(2)High-glucose environment down-regulated the mRNA and protein level expressions of osteogenic-related genes α1-I collagen,alkaline phosphatase,Runt-associated transcription factor 2,and osteocalcin in human umbilical cord mesenchymal stem cells,which induced oxidative stress and cellular senescence.(3)Vitamin D3 at an intervention concentration of 10 μmol/L significantly restored the osteogenic phenotype of human umbilical cord mesenchymal stem cells under high-glucose conditions and attenuated intracellular oxidative stress and cellular senescence by activating the Nrf2/HO-1 signaling pathway.(4)These findings suggested that the osteogenic differentiation ability of human umbilical cord mesenchymal stem cells was reduced in the high-glucose environment,and vitamin D3 could partially improve their osteogenic differentiation ability and reduce cell damage.
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BACKGROUND:Cellular senescence is closely related to the development and progression of osteoarthritis,but the specific targets and regulatory mechanisms are not yet clear. OBJECTIVE:To mine key genes in cellular senescence-mediated osteoarthritis by integrating bioinformatics and machine learning approaches and validate them via experiments to explore the role of cellular senescence in osteoarthritis. METHODS:The osteoarthritis gene expression profiles obtained from the GEO database were intersected with cellular senescence-related genes obtained from the CellAge database and the expression of the intersected genes was extracted for differential analysis,followed by GO and KEGG analysis of the differential genes.The key osteoarthritis cellular senescence genes were then screened by protein-protein interaction network analysis and machine learning,and in vitro cellular experiments were performed.Finally,the expression of the key genes was detected by qPCR. RESULTS AND CONCLUSION:A total of 31 osteoarthritis cell senescence differential genes were identified.GO analysis showed that these genes were mainly involved in the biological processes,such as regulation of leukocyte differentiation,monocyte differentiation,regulation of T cell differentiation and exerted roles in DNA transcription factor binding,histone deacetylase binding,chromatin DNA binding,and chemokine binding.KEGG analysis showed that osteoarthritis cell senescence differential genes were mainly activated in the JAK/STAT signaling pathway,PI3K/Akt signaling pathway and FoxO signaling pathway.MYC,a key gene for osteoarthritis cellular senescence,was identified by protein-protein interaction network topology analysis and machine learning methods.The results of the in vitro cellular assay showed that the mRNA expression of MYC was significantly lower in the experimental group(osteoarthritis group)than the control group(normal group)(P＜0.05).To conclude,MYC can be a key gene in the senescence of osteoarthritic cells and may be a new target in the prevention and treatment of osteoarthritis by mediating immune response,inflammatory response and transcriptional regulation.
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BACKGROUND:Peroxisome proliferators-activated receptor gamma co-activator 1α(PGC-1α)is closely related to aging and plays an important regulatory role in exercise anti-aging.However,there is a lack of comprehensive reviews on the role of PGC-1α in exercise anti-aging from the perspective of different tissues and organs. OBJECTIVE:To provide a detailed overview of the role of PGC-1α in exercise anti-aging and discuss its regulation from the perspective of different tissues and organs. METHODS:A literature search was conducted from May 1,2023 to July 1,2023.The search covered self-built databases up to July 2023,as well as databases such as Web of Science,PubMed,China National Knowledge Infrastructure(CNKI),WanFang,and VIP.The Chinese search terms included"PGC-1α,peroxisome proliferators-activated receptor gamma co-activator 1α,PPARGC1A,aging,exercise,older adults".The English search terms were"PGC-1α,aging,exercise,exercise training,older adults".Boolean logical operators were used to connect the search terms,and corresponding search strategies were developed.Based on inclusion and exclusion criteria,83 articles were included in the review. RESULTS AND CONCLUSION:(1)PGC-1α is an important transcriptional coactivator that plays a key regulatory role in maintaining mitochondrial function,regulating energy metabolism,and adapting to different metabolic demands.(2)PGC-1α has a significant regulatory role in mitochondrial aging and various functions in multiple cell types,and is associated with inflammatory pathways,redox control,protein modifications,and epigenetic changes.(3)The expression level of PGC-1α can be increased by exercise training,and it exerts positive effects through regulating mitochondrial biogenesis,energy metabolism,and anti-oxidative stress pathways.It plays an important role in exercise-induced improvement of adipose tissue aging,cardiovascular aging,neurosystem aging,renal aging,skeletal muscle aging,and liver aging.(4)The expert group recommends future research directions including exploring the regulatory effects of different types,intensities,and durations of exercise on PGC-1α expression,studying the regulatory mechanisms of protein modifications and epigenetic changes in PGC-1α, and strengthening the research on the mechanisms of PGC-1α in different aging-related diseases.
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BACKGROUND:There is still controversy whether human bone marrow mesenchymal stem cells can maintain their biological characteristics,energy metabolism patterns,and multidirectional differentiation potential after long-term expression in vitro.Further comprehensive and systematic research is needed. OBJECTIVE:To evaluate the effects of long-term expansion in vitro on the biological characteristics of mesenchymal stem cells. METHODS:Human bone marrow mesenchymal stem cells cultured to passage 5,10,and 15 in vitro.MTT assay was used to detect cell proliferation ability.Flow cytometry was used to detect cell cycle.The multi-differentiation potential of mesenchymal stem cells was detected by inducing to adipogenic,osteogenic and chondrogenic differentiation.Cell migration and invasion abilities were detected by scratch test and Transwell assay.The mitochondrial oxidative phosphorylation and glycolysis function were analyzed using energy metabolism analyzer.The cell senescence was detected by senescence-associated β-galactosidase staining.The expression levels of p21,p16,and p53 proteins were detected by western blot assay. RESULTS AND CONCLUSION:Bone marrow mesenchymal stem cells at passages 5,10,and 15 grew adherently;the volume of passage 15 mesenchymal stem cells increased and its proliferation ability decreased;the percentage of S-phase cells decreased(P<0.05).With the increase of culture passages,the migration and invasion abilities decreased gradually(P<0.05).There was no significant difference in the differentiation potential,demonstrated by adipogenic,osteogenic and chondrogenesis induction.The ability of oxidative phosphorylation of mitochondria and glycolysis decreased gradually(P<0.05).The number of senescence-associated β-galactosidase-positive cells increased with the increase of passages(P<0.05),and the expression of senescence protein p21,p16,and p53 increased gradually(P<0.05).The results indicated that the biological characterization of mesenchymal stem cells changed after long-term in vitro expansion.Mesenchymal stem cells cultured over 10 passages may have a reduced activity due to increasing senescence.Therefore,bone marrow mesenchymal stem cells cultured less than 10 passages are suitable for clinical research/therapy.
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BACKGROUND:Mesenchymal stem cells are susceptible to senescence during in vitro expansion,which greatly hinders their application in vivo and in vitro.How to improve the replicative senescence of mesenchymal stem cells is an urgent problem to be solved in tissue engineering. OBJECTIVE:To determine whether vascular endothelial growth factor combined with basic fibroblast growth factor can improve the aging of bone marrow mesenchymal stem cells caused by replicative passage. METHODS:Rat bone marrow mesenchymal stem cells were extracted by whole bone marrow adhesion method.Passage 2 cells were selected as normal control group.Passage 7 and later algebraic cells were selected as aging model group.Vascular endothelial growth factor(50 μg/L),basic fibroblast growth factor(10 μg/L),and their combination were administered.Cell proliferation was detected by CCK-8 assay.Cell senescence was observed by β-galactosidase activity staining.Cytoskeleton size and colony formation ability were observed by phalloidine staining and Giemsa staining,respectively,and the levels of senescence-related genes P16,P21,and P53 were detected by qRT-PCR.Gene expression levels of P16,P21,and P53 were tested by qRT-PCR. RESULTS AND CONCLUSION:(1)Vascular endothelial growth factor combined with basic fibroblast growth factor could promote the proliferation of aged bone marrow mesenchymal stem cells,which began to enter the plateau stage on day 9,and the absorbance value of the combined intervention group was significantly higher than that of the model group on day 9(P<0.05).(2)The phenotypic markers of the cells in the combined intervention group did not change,and the cell morphology changed from broad to slender.(3)Compared with the model group,the positive rate of β-galactosidase was significantly decreased(P<0.01);the number of nuclei increased(P<0.001);the total area of cytoskeleton increased(P<0.01);colony formation ability was enhanced(P<0.05);expression level of P16 was decreased(P<0.01)in the combined intervention group.These results indicate that vascular endothelial growth factor combined with basic fibroblast growth factor can improve the senescence of bone marrow mesenchymal stem cells caused by replicative passage without changing the cell phenotype.
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BACKGROUND:The results of in vivo and in vitro studies showed that catalpol from Rehmannia glutinosa can significantly reduce the level of inflammatory indexes in the synovial tissue of rats with knee osteoarthritis,and meanwhile,it can delay the progression of knee osteoarthritis.But whether catalpol from Rehmannia glutinosa affects chondrocyte senescence and then delay the progression of knee osteoarthritis has not yet been clarified. OBJECTIVE:To investigate investigate whether catalpol from Rehmannia glutinosa could regulate ATDC5 chondrocyte senescence and the possible mechanisms. METHODS:ATDC5 chondrocytes were divided into blank group(0.1%bovine serum albumin),model group(0.1%bovine serum albumin+1 μmol/L adriamycin),low-dose catalpol group(0.1%bovine serum albumin+1 μmol/L adriamycin+20 μmol/L catalpol from Rehmannia glutinosa)and high-dose catalpol group(0.1%bovine serum albumin+1 μmol/L adriamycin+80 μmol/L catalpol from Rehmannia glutinosa).Adriamycin-induced ATDC5 chondrocyte senescence model was constructed,and the corresponding treatments were given according to the above groups.Cell counting kit-8 assay was used to detect the effects of catalpol from Rehmannia glutinosa on ATDC5 chondrocyte viability,and to screen the optimal concentration of catalpol from Rehmannia glutinosa.The senescence of ATDC5 chondrocytes in each group was detected by β-galactosidase staining after the corresponding treatments.Real-time fluorescence quantitative PCR and western blot were used to detect the mRNA and protein expression of P21,P53,type II collagen,matrix metalloproteinase 13,and interleukin-6.Immunofluorescence method was used to detect the expression of P21,P53 and type II collagen.Flow cytometry was used to detect apoptosis in each group. RESULTS AND CONCLUSION:ATDC5 chondrocytes were identified to be successfully induced and senescence model was induced.Catalpol from Rehmannia glutinosa at the concentrations of 0,20,40,and 80 μmol/L showed no significant effects on the cell viability,suggesting that catalpol from Rehmannia glutinosa is non-cytotoxic and can be used safely(P>0.05);when the concentration was≥100 μmol/L,the cell viability was reduced,suggesting that there may be cytotoxic.Therefore,80 μmol/L was chosen as the high dose for subsequent experiments in this study.The percentage of positive cells in the model group was(86.93±2.18)%,which was significantly higher than that in the blank group[(17.32±0.72)%;P<0.05].Compared with the model group,the percentage of positive cells was significantly lower in the low-and high-dose catalpol groups[(57.28±1.73)%and(27.18±0.97)%,respectively;both P<0.05].Compared with the model group,the relative expression of P21,P53,matrix metalloproteinase 13,and interleukin-6 at mRNA and protein levels was significantly downregulated in the low-and high-dose catalpol groups,while the relative expression of type II collagen at mRNA and protein levels was significantly upregulated in both groups(P<0.05),especially in the high-dose catalpol group(P<0.05).Compared with the model group,the fluorescence intensities of P21 and P53 were significantly weakened in the low-and high-dose catalpol groups,while the fluorescence intensity of type II collagen was significantly enhanced in the low-and high-dose catalpol groups(P<0.05),especially in the high-dose catalpol group(P<0.05).The cell apoptosis detected by Annexin V/PI method showed that there was no significant difference between the model group and the blank group(P>0.05);compared with the model group,the apoptotic index was significantly elevated in the low-and high-dose catalpol groups,especially in the high-dose catalpol group(P<0.05).To conclude,catalpol from Rehmannia glutinosa can slow the progression of osteoarthritis by promoting apoptosis of senescent ATDC5 chondrocytes,further removing senescent ATDC5 chondrocytes,and decreasing the senescence-associated phenotypes.
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Radiation-induced damage to vascular endothelium is a major complication of radiotherapy and a primary cause of morbidity and mortality in the population exposed to radiation. Ionizing radiation-induced cellular senescence serves as a critical factor in damage to vascular endothelial cells. Therefore, understanding the mechanisms of cellular senescence caused by senescence-associated secretory phenotype (SASP), as well as its role in ionizing radiation-induced damage to vascular endothelial cells, is significant for preventing and treating ionizing radiation-induced damage to vascular endothelial cells. In this study, the relationship between SASP-related premature senescence and this ionizing radiation-induced damage was explored from the following aspects: the mechanisms behind ionizing radiation-induced damage to vascular endothelial cells, ionizing radiation-induced cellular senescence, and the role of SASP-related premature senescence in the ionizing radiation-induced damage to vascular endothelial cells, as well as potential targets.
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Objective To investigate the effect of 3-n-butylphthalide(NBP)on etoposide-induced senescence in human umbilical vein endothelial cells(HUVECs).Methods HUVECs were divid-ed into blank control group,etoposide group(500 nmol/L etoposide+dimethyl sulfoxide),etopo-side+low-,medium-and high-dose NBP groups(500 nmol/L etoposide+5,10 and 20 μmol/L NBP,respectively).Senescence-related β galactosidase(SA-β-gal)staining was used to observe the change in senescent cell proportion.Real-time quantitative PCR was employed to detect the mRNA levels of senescence-associated secretory phenotype(SASP),such as IL-8,IL-1β,and CXC chemokine ligand 1(CXCL1).Western blotting was applied to measure the expression level of ag-ing-related protein,P21.Immunofluorescence staining was utilized to detect the proportion of pro-liferation-related protein Ki67 positive cells.Results Significantly higher P21 expression(1.00± 0.00 vs 0.59±0.09),larger ratio of SA-β-gal positive cells(29.58±4.51)％vs(11.27±1.18)％,increased mRNA levels of IL-8(2.49±0.11 vs 1.00±0.03),IL-1β(6.32±0.15 vs 1.00±0.03)and CXCL1(2.40±0.24 vs 1.00±0.04),but reduced proportion of Ki67 positive cells(5.95±1.55)％vs(27.38±7.00)％were observed in the etoposide group than the blank control group(P＜0.05).Low-dose NBP treatment decreased the ratio of SA-β-gal positive cells,P21 protein level,and mRNA level of IL-1β,and increased the proportion of Ki67 positive cells when compared with the etoposide group(P＜0.05).Conclusion NBP has an antagonistic effect on etoposide-induced se-nescence of vascular endothelial cells.
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Background The senescence of alveolar type II epithelial cells is an important driving factor for the progression of silicotic fibrosis, and the regulatory effects of oxamate on the senescence of alveolar type II epithelial cells is still unclear. Objective To explore whether lactate dehydrogenase inhibitor oxamate can alleviate silicotic fibrosis in mice by inhibiting senescence of alveolar type II epithelial cellsMethods This study was divided into two parts: in vivo experiments and in vitro experiments. In the first part, forty SPF C57BL/6J male mice were randomly divided into four groups with 10 in each group: control group, silicosis model group, low-dose oxamate treatment group, and high-dose oxamate treatment group. The silicotic mouse model was established by intratracheal instillation of 50 μL SiO2 suspension (100 mg·mL−1). The treatment models were prepared by intraperitoneal injection of 100 μL oxamate (225 mmol·L−1 and 1125 mmol·L−1). In the second part, induction of MLE-12 mouse alveolar type II epithelial cells was conducted with SiO2. The in vitro experimental groups were ① SiO2 induction groups: control group, 50 μg·mL−1 SiO2 group, 100 μg·mL−1 SiO2 group, and 200 μg·mL−1 SiO2 group, and ② oxamate treatment groups: control group, SiO2 group (100 μg·mL−1), low-dose oxamate (25 mmol·L−1) treatment group, and high-dose oxamate (50 mmol·L−1) treatment group. Pathological morphology of lung tissues was evaluated after hematoxylin-eosin (HE) staining; deposition of collagen in lung tissues was evaluated after sirius red staining; positive co-expression of prosurfactant protein C (Pro-SPC) and β-galactosidase was detected by immunofluorescence staining; positive expression of β-galactosidase in MLE-12 cells was detected by immunofluorescence staining. The protein expression levels of collagen type I (CoL I), fibronectin1 (FN1), hexokinase 2 (HK2), pyruvate kinase isozyme type M2 (PKM2), lactate dehydrogenase A (LDHA), p-ataxia telangiectasia and Rad3-related kinase (ATR), and cyclin-dependent kinase inhibitors p21, and p16 were detected by Western blotting. Results Compared with the control group, the protein expression levels of HK2, PKM2, LDHA, p-ATR, p21, and p16 were significantly upregulated in the silicosis model group and the SiO2-induced MLE-12 cells (P＜0.05). The in vivo studies showed that, compared with the control group, the silicon nodule area, the collagen deposition area, the proportion of β-galactosidase positive cells, and the protein expression levels of CoL I, FN1, LDHA, p-ATR, p21, and p16 were significantly upregulated in the silicosis model group (P＜0.05). Compared with the silicosis model group, the oxamate treatment groups showed significant downregulation of the silicon nodule area, the collagen deposition area, the proportion of β-galactosidase positive cells, and the the CoL I, FN1, LDHA, p-ATR, p21, and p16 protein expression levels, and the high-dose oxamate treatment group showed a higher efficacy on these indicators than the low-dose oxamate treatment group (P＜0.05). The in vitro studies showed that, compared with the control group, the proportion of β-galactosidase positive cells and the protein expression levels of p-ATR, p21, and p16 were significantly upregulated in the SiO2-induced group (P＜0.05). Compared with the SiO2 group, the proportion of β-galactosidase positive cells and the LDHA, p-ATR, p21 and p16 protein expression levels were significantly downregulated in the oxamate treatment groups, and the high-dose oxamate treatment group showed a higher efficacy on these indicators than the low-dose oxamate treatment group (P＜0.05). Conclusion Lactate dehydrogenase inhibitor oxamate can alleviate silicotic fibrosis in mice by inhibiting the senescence of alveolar type II epithelial cells.