Research progress on molecular mechanism of traditional chinese medicine active ingredients interfering bone marrow mesenchymal stem cells senescence / 中国临床药理学与治疗学

The senescence of bone marrow mesenchymal stem cells (BM-MSCs) will induce age-related bone tissue degeneration and chronic inflammation, and reduce its application effect for cell therapy. More and more active ingredients of traditional chinese medicine have been proved to intervene BM - MSCs senescence, playing an important role in bone diseases prevention and treatment, and improving the therapeutic effect of BM-MSCs. In this paper, the latest research progress on the molecular mechanism of traditional chinese medicine active ingredients interfering BM-MSCs senescence was summarized, in order to provide new direction and reference basis for senescence intervention research and clinical application improvement of BM-MSCs.

Lycium barbarian seed oil activates Nrf2/ARE pathway to reduce oxidative damage in testis of subacute aging rats / 中国药理学通报

Aim To explore the effects of Lycium berry seed oil on Nrf2/ARE pathway and oxidative damage in testis of subacute aging rats. Methods Fifty out of 60 male SD rats, aged 8 weeks, were subcutaneously injected with 125 mg • kg"D-galactosidase in the neck for 8 weeks to establish a subacute senescent rat model. The presence of senescent cells was observed using P-galactosidase ((3-gal), while testicular morphology was examined using HE staining. Serum levels of testosterone (testosterone, T), follicle-stimulating hormone ( follicle stimulating hormone, FSH ) , luteinizing hormone ( luteinizing hormone, LH ) , superoxide dis-mutase ( superoxide dismutase, SOD ) , glutathione ( glutathione, GSH) and malondialdehyde ( malondial-dehyde, MDA) were measured through ELISA, and the expressions of factors related to aging, oxidative damage, and the Nrf2/ARE pathway were assessed via immunohistochemical analysis and Western blotting. Results After successfully identifying the model, the morphology of the testis was improved and the intervention of Lycium seed oil led to a down-regulation in the expression of [3-gal and -yH2AX. The serum levels of SOD, GSH, T, and FSH increased while MDA and LH decreased (P 0. 05) . Additionally, there was an up-regulated expression of Nrf2, GCLC, NQOl, and SOD2 proteins in testicular tissue ( P 0. 05 ) and nuclear expression of Nrf2 in sertoli cells. Conclusion Lycium barbarum seed oil may reduce oxidative damage in testes of subacute senescent rats by activating the Nrf2/ARE signaling pathway.

Research progress on bone metabolism and molecular mechanisms in accelerated aging SAMP6 mice / 中国药理学通报

Senile osteoporosis (SOP) is a systemic bone disease characterized by increased susceptibility to fractures. The pathogenesis of SOP is complex and not well understood. Currently, the rapid aging model mouse, senescence accelerated mouse prone 6 (SAMP6), is an ideal model for studying the mechanisms of SOP development and exploring its prevention and treatment. This model exhibits characteristics including increased bone fragility, degradation of bone microstructure, loss of bone matrix, and abnormal metabolism and dysfunction of bone cells, faithfully replicating the process of SOP occurrence and progression at both macroscopic and microscopic levels.

Effects of fractionated low-dose ionizing radiation in the induction of EA.hy926 cell senescence / 中国辐射卫生

Objective To investigate the mechanism of fractionated low-dose ionizing radiation (LDIR) in the induction of EA.hy926 cell senescence. Methods EA.hy926 cells were irradiated with X-ray at 0, 50, 100, and 200 mGy × 4, respectively, and cultured for 24, 48, and 72 h. Several indicators were measured, including the levels of cellular senescence-associated β-galactosidase (SA-β-gal) staining, mRNA levels of senescence-associated cell cycle protein-dependent kinase inhibitor genes CDKN1A and CDKN2A, reactive oxygen species (ROS), total antioxidant capacity (T-AOC), and phosphorylated H2A histone family member X (γ-H2AX). Results After 4 fractionated LDIR, compared with the control group, the treatment groups showed increased nucleus area, blurred cell edge, and increased SA-β-gal positive area (P < 0.05) at 24, 48 and 72 h. After 4 fractionated LDIR, the mRNA level of CDKN1A increased in the 100 and 200 mGy × 4 groups at 24 and 48 h (P < 0.05), and CDKN2A mRNA level increased in the 100 and 200 mGy × 4 groups at 48 and 72 h (P < 0.05). The fluorescence intensity of ROS increased in treatment groups at 24, 48, and 72 h after 4 fractionated LDIR (P < 0.05). After 4 fractionated LDIR, the T-AOC level increased in the 100 and 200 mGy × 4 groups at 24 h (P < 0.05), and T-AOC level increased in all treatment groups at 48 and 72 h (P < 0.05). After 4 fractionated LDIR, γ-H2AX fluorescence intensity increased in all treatment groups at 24 h (P < 0.05), and the fluorescence intensity increased in the 100 and 200 mGy × 4 groups at 48 and 72 h (P < 0.05). Conclusion Fractionated LDIR can induce cellular senescence in EA.hy926 cells by impacting the cellular oxidation-antioxidation and oxidative damage levels, and the effects were relatively evident at 100 and 200 mGy.

Anti-cancer Effect of Traditional Chinese Medicine in Regulating Cellular Senescence： A Review / 中国实验方剂学杂志

In recent years， the incidence and mortality rates of cancer have been increasing， posing a serious threat to human health. Western medicine mainly uses treatments such as surgical resection， chemotherapy， immunotherapy and targeted therapy， but they are prone to complications， drug resistance and adverse reactions. A growing number of studies have shown that traditional Chinese medicine has obvious advantages in the treatment of cancer， reducing the recurrence rate of cancer and improving the quality of survival of patients. Cellular senescence refers to a state of irreversible cell cycle growth arrest when cells cease to proliferate after a limited number of divisions， resulting in a decline in cell proliferation and differentiation capacities and physiological functions， accompanied by morphological changes such as flattening and multinuclear morphology. At the molecular level， it shows increased expression of DNA damage-related genes， reduced expression of cell cycle-related factors and significant secretory activity. The malignant development of cancer is closely related to cellular senescence. With the increasing number of cancer cell proliferation， cancer-related genes undergo continuous mutations， freeing them from cellular senescence and thus achieving unlimited proliferation. Through recent studies， it has been found that induction of tumor cell senescence， possibly through modulation of cellular DNA damage， cell cycle arrest and senescence-associated secretory phenotype （SASP）， which converts the suppressive immune tumor microenvironment to an activated immune tumor microenvironment and thus reverses the escape of tumor cell senescence， is a promising strategy for cancer therapy. However， the mechanism of cellular senescence in cancer progression is not fully understood， especially the anti-cancer role played by traditional Chinese medicine in regulating cellular senescence. This article summarized and concluded the specific molecular mechanisms of cellular senescence， the role of cellular senescence in cancer progression， and the mechanism of anti-cancer effects of traditional Chinese medicine based on cellular senescence from the perspective of regulating cellular senescence， with a view to providing ideas and methods for the anti-cancer effects of traditional Chinese medicine and the development of new drugs.

Down-regulation of XBP1s alleviates the senescence of renal tubular epithelial cells induced by hypoxia/reoxygenation through Sirt3/SOD2/mtROS signaling pathway / 器官移植

Objective To investigate the role and mechanism of spliced X-box binding protein 1 (XBP1s) in the senescence of primary renal tubular epithelial cells induced by hypoxia/reoxygenation (H/R). Methods Primary renal tubular epithelial cells were divided into the normal control group (NC group), H/R group, empty adenovirus negative control group (Ad-shNC group), targeted silencing XBP1s adenovirus group (Ad-shXBP1s group), empty adenovirus+H/R treatment group (Ad-shNC+H/R group) and targeted silencing XBP1s adenovirus+H/R treatment group (Ad-shXBP1s +H/R group), respectively. The expression levels of XBP1s in the NC, H/R, Ad-shNC and Ad-shXBP1s groups were measured. The number of cells stained with β-galactosidase, the expression levels of cell aging markers including p53, p21 and γH2AX, and the levels of reactive oxygen species (ROS), malondialdehyde (MDA) and superoxide dismutase (SOD) were determined in the Ad-shNC, Ad-shNC+H/R and Ad-shXBP1s+H/R groups. Chromatin immunoprecipitation was employed to verify Sirtuin 3 (Sirt3) of XBP1s transcription regulation, and the expression levels of Sirt3 and downstream SOD2 after down-regulation of XBP1s were detected. Mitochondrial reactive oxygen species (mtROS) were detected by flow cytometry. Results Compared with the NC group, the expression level of XBP1s was up-regulated in the H/R group. Compared with the Ad-shNC group, the expression level of XBP1s was down-regulated in the Ad-shXBP1s group (both P<0.001). Compared with the Ad-shNC group, the number of cells stained with β-galactosidase was increased, the expression levels of p53, p21 and γH2AX were up-regulated, the levels of ROS, MDA and mtROS were increased, the SOD activity was decreased, the expression level of Sirt3 was down-regulated, and the ratio of Ac-SOD2/SOD2 was increased in the Ad-shNC+H/R group. Compared with the Ad-shNC+H/R group, the number of cells stained with β-galactosidase was decreased, the expression levels of p53, p21 and γH2AX were down-regulated, the levels of ROS, MDA and mtROS were decreased, the SOD activity was increased, the expression level of Sirt3 was up-regulated and the ratio of Ac-SOD2/SOD2 was decreased in the Ad-shXBP1s+H/R group (all P<0.05). Conclusions Down-regulation of XBP1s may ameliorate the senescence of primary renal tubular epithelial cells induced by H/R, which probably plays a role through the Sirt3/SOD2/mtROS signaling pathway.

Genética y genómica de la longevidad y el envejecimiento / Genetics and genomics of longevity and aging

El envejecimiento y la longevidad son procesos que involucran una serie de factores genéticos, bioquímicos y ambientales. En esta revisión se tratan algunas cuestiones sobre estos dos procesos biológicos y epigenéticos. Se presentan los genes más importantes en estos procesos, así como se ejemplifican enfermedades que presentan un aceleramiento o falla en la longevidad y el envejecimiento. Se usa el análisis inteligente de datos para hallar interacciones de proteínas/genes que expliquen estos dos fenómenos biológicos.

Aging and longevity are processes that involve a series of genetic, biochemical and environmental factors. This review addresses some issues about these two biological and epigenetic processes. The most important genes in these processes are presented, as well as diseases that present an acceleration or failure in longevity and aging. Intelligent data analysis is used to find protein/gene interactions that explain these two biological phenomena.

Senescence in oral lichen planus as assessed by the immunohistochemical evaluation of senescence marker protein-30 (Regucalcin)

Background: Oral lichen planus is a T-cell-mediated chronic inflammatory disease affecting approximately 1% to 2% of the population, the etiology of which is currently unknown. The objectives of this study were to observe if senescence occurs in oral lichen planus, through the assessment of the immunohistochemical expression of a novel marker for senescence called Senescence marker protein-30 or regucalcin, and compare the expression to that in oral lichenoid reaction and non-specific inflammation. Subjects and Methods: The study material consisted of 30 cases of oral lichen planus, 15 cases of oral lichenoid reaction and 15 cases of non-specific inflammation. The number of positive cells in ten randomly selected high power fields were counted in the epithelium and the connective tissue separately and the mean was determined. Results: Mann–Whitney U test was used to statistically analyze if there was any significant difference in the expression of Senescence marker protein-30 between oral lichen planus, oral lichenoid reaction and non-specific inflammation. Even though a greater expression was seen in the oral lichen planus cases than oral lichenoid reaction, the difference in both the epithelium and connective tissue was not statistically significant. Conclusion: This study shows that in addition to the already known mechanisms like apoptosis and increased cell proliferation rates, the activated T-lymphocytes may also trigger a senescent change in the cells of oral lichen planus. As with the other mechanisms, this is also seen only in a small proportion of the cases.

Downregulated miR-181a alleviates H2O2-induced oxidative stress and cellular senescence by targeting PDIA6 in human foreskin fibroblasts

Abstract Background Oxidative stress is strongly associated with cellular senescence. Numerous studies have indicated that microRNAs (miRNAs) play a critical part in cellular senescence. MiR-181a was reported to induce cellular senescence, however, the potential mechanism of miR-181a in hydrogen peroxide (H2O2)-induced cellular senescence remains obscure. Objective The aim of this study is to investigate the role and regulatory mechanism of miR-181a in H2O2-induced cellular senescence. Methods Human foreskin fibroblasts (HFF) transfected with miR-181a inhibitor/miR-NC with or without H2O2 treatment were divided into four groups: control + miR-NC/miR-181a inhibitor, H2O2 + miR-NC/miR-181a inhibitor. CCK-8 assay was utilized to evaluate the viability of HFF. RT-qPCR was used to measure the expression of miR-181a and its target genes. Protein levels of protein disulfide isomerase family A member 6 (PDIA6) and senescence markers were assessed by western blotting. Senescence-associated β-galactosidase (SA-β-gal) staining was applied for detecting SA-β-gal activity. The activities of SOD, GPx, and CAT were detected by corresponding assay kits. The binding relation between PDIA6 and miR-181a was identified by luciferase reporter assay. Results MiR-181a inhibition suppressed H2O2-induced oxidative stress and cellular senescence in HFF. PDIA6 was targeted by miR-181a and lowly expressed in H2O2-treated HFF. Knocking down PDIA6 reversed miR-181a inhibition-mediated suppressive impact on H2O2-induced oxidative stress and cellular senescence in HFF. Study limitations Signaling pathways that might be mediated by miR-181a/PDIA6 axis were not investigated. Conclusion Downregulated miR-181a attenuates H2O2-induced oxidative stress and cellular senescence in HFF by targeting PDIA6.

Research advances in the association between metabolic associated fatty liver and type 2 diabetes mellitus and the mechanism of comorbidity / 临床肝胆病杂志

There are gradual increases in the incidence rates of metabolic associated fatty liver disease （MAFLD） and type 2 diabetes mellitus （T2DM）， with close relationship and mutual interaction between the two diseases， but the specific mechanism is still unclear. Studies have shown that T2DM and MAFLD may cause aggravation of each other through insulin resistance， inflammation， some hepatocyte factors， and cellular senescence and protect each other through some hepatocyte factors. Further research on the association between T2DM and MAFLD and the mechanism of comorbidity is of great significance for the clinical prevention and treatment of the two diseases.

Cellular senescence and type 2 diabetes / 中华内分泌代谢杂志

Cellular senescence is a state in which cells enter permanent cell cycle arrest, which is characterized by senescence-associated secretory phenotype secretion, macromolecular damage, metabolic dysregulation and so on. Recent studies have shown a close relationship between cellular senescence and type 2 diabetes. On the one hand, the glycolipotoxic microenvironment of type 2 diabetes can accelerate cell senescence and accumulation. On the other hand, cellular senescence can promote the development of type 2 diabetes. For example, senescence of pancreatic β-cells leads to β-cell dysfunction and adipocytes senescence results in the secretion of pro-inflammatory cytokines, causing disturbances in lipid metabolism and exacerbating insulin resistance. Moreover, senescence of endothelial cells, retinal endothelial cells, and other cell types contributes to the occurrence of chronic complications in diabetes. Cellular senescence is not only an important factor in the onset of type 2 diabetes but also a consequence of its progression. Targeting cellular senescence holds promise as a new strategy for the treatment of type 2 diabetes.

Effect of autophagic core protein Atg101 on adipocyte senescence / 中华内分泌代谢杂志

Objective:To investigate the effect of autophagy related gene Atg101 on white adipocyte senescence.Methods:An Atg101 knockdown model of 3T3-L1 mature adipocytes was constructed to probe the effect of Atg101 on autophagy-related proteins LC3 and p62 protein. The RNA-seq database of human subcutaneous adipose tissue was constructed and analyzed, and the co-expressed gene set was predicted based on the pearson correlation coefficient( R2>0.4, P<0.05) between FPKM values of Atg101 and other gene, followed by KEGG and Reactome enrichment analysis. Young mouse(8 weeks old) and old mouse(18 months old) models were established, and the expression levels of Atg101 in inguinal white adipose tissue and epididymal white adipose tissue were detected by quantitative real-time PCR(RT-qPCR) and Western blot. Furthermore, the differences in white adipocyte senescence-associated secretory phenotype(SASP), cell cycle and mitochondrial homeostasis-related genes were detected by RNA-seq, Western blot, and RT-qPCR to analyze the effects of Atg101 silencing on adipocyte senescence. Results:The autophagy-related protein LC3-Ⅱ expression was significantly decreased and p62 protein was induced after Atg101 was knockdowned in 3T3-L1 adipocytes, suggesting impaired cell autophagy. KEGG enrichment analysis revealed that Atg101 co-expressed gene set was mainly enriched in autophagy and senescence-related pathways; Reactome enrichment analysis revealed that this gene set was associated with multiple cell cycle signaling pathways. RT-qPCR and Western blot confirmed that both mRNA and protein levels of Atg101 were down-regulated in inguinal white adipose tissue of aging mice, and protein levels in epididymal white adipose tissue were also significantly reduced. Finally, it was further confirmed that SASP-related genes were induced after Atg101 knockdown in white adipocytes, and cell cycle-specific gene expression was restricted and cytokine-dependent protein kinase inhibitors p16 and p21 expressions were significantly increased, while mitochondrial homeostasis regulatory genes were also suppressed.Conclusions:Knockdown of Atg101 may regulate white adipocyte senescence by inhibiting autophagic activity, presenting impaired mitochondrial homeostasis.

Characteristics, cellular and molecular mechanisms of renal aging and nutritional intervention strategies / 中华老年医学杂志

Renal aging is a gradual process of degenerative changes in tissue structure and physiological function and is closely related to the occurrence and development of acute kidney injury(AKI)and chronic kidney disease(CKD). The cellular and molecular mechanisms of renal aging mainly include cellular senescence and reduced autophagy, and are regulated by nutritional factors.Promoting reasonable and moderate energy-and protein-restricted diets, strengthening the supervision of food additives and preservatives, cultivating safety awareness of residents, and strictly controlling the daily salt intake are potential nutritional intervention strategies to prevent and delay renal aging.Given the limited number of studies, there is an urgent need to further explore the effectiveness of the above strategies to provide a new evidence-based approach to formulating precise and feasible personalized nutritional intervention programs.

Mechanism of racanisodamine on alleviating radiation-induced lung injury in mice / 中华放射医学与防护杂志

Objective:To investigate the protective effect of racanisodamine on lung injury in mice exposed to irradiation.Methods:C57BL/6 mice were randomly divided into control group, racanisodamine group, 18 Gy irradiation group (model group) and racanisodamine combined with 18 Gy irradiation group (treatment group), with 5 mice in each group. The mice in the treatment group received racanisodamine (5 mg/kg) intraperitoneally 3 d before irradiation and contained the whole experiments. Then, single chest irradiation of 18 Gy X-rays was performed both in the model and treatment groups. The racanisodamine group and treatment group received racanisodamine intraperitoneally once a day until 6 weeks after irradiation. The mice were killed at 6 weeks after irradiation. The lung histopathology was observed by HE staining. Serum and bronchial alveolar lavage fluid (BALF) inflammatory cytokines such as TNF-α, IL-1β and IL-6 were determined by ELISA method. Cell senescence was detected by SA-β-Gal staining. The expressions of Nrf2, p-Nrf2 and p62 in lung tissue were performed by immunehistochemistry and Western blot assays.Results:Compared with the model group, the scores of HE staining were decreased ( t=8.66, P<0.01), the number of infiltrated inflammatory cells in BALF were decreased ( t=10.70, P<0.01), and protein concentration in BALF had lower levels ( t=6.75, P<0.01), the serum TNF-α, IL-1β and IL-6 were decreased significantly ( t=8.17, 4.58, 6.54, P<0.01), the activity of SA-β-gal was decreased, and the expressions of Nrf2, p-Nrf2 were enhanced ( t=6.42, 7.30, P<0.01), while the expression of p62 was reduced ( t=4.62, P<0.01) in the treatment group. Conclusions:Racanisodamine plays the protective effect of radiation-induced lung injury by alleviating inflammation associating with the activating of Nrf2-related pathway, which reversed radiation-induced cell senescence.

Research progress on the role and mechanism of premature cellular senescence on wound healing in radiation-induced skin injury / 中华放射医学与防护杂志

Radiation skin injury can be induced by medical exposure, occupational exposure, and emergency exposure. Many relevant studies focused on the prevention and treatment of radiation-induced skin injury, but the underlying molecular mechanisms have not been fully clarified. It has been demonstrated that radiation-induced premature cellular senescence is involved in radiation skin injury. To discuss the relationship between radiation-induced premature cellular senescence and radiation-induced skin injury, this paper reviewed the mechanism of radiation-induced skin injury, the promotion of premature cellular senescence and related signal pathways, and the role of premature cellular senescence in wound healing.

Research progress of cellular senescence in glaucoma / 中华实验眼科杂志

Cellular senescence is a response process in which cells are activated by ischemia, hypoxia, oxidative stress, DNA damage, reactive oxygen species deposition and other stimulations.Senescent cells markers include such as senescence-associated β-galactosidase (SA-β-gal) activation, P16INK4a upregualtion, senescence-associated heterochromatic foci (SAHF) accumulation, senescence-associated secretory phenotype (SASP) generation, telomere shortening and so on.P16INK4a/Rb and P19 ARF/P53/P21 Cip1 pathways are two classic cell senescence signaling pathways, which are interconnected and independent on each other.In recent years, glaucoma is considered as a blinding eye disease associated with cell senescence.Research on cell senescence in glaucoma mainly focuses on trabecular meshwork and Schlemm cannel endothelial cells senescence leading to increased resistance of aqueous humor outflow pathway, and the mechanism of retinal ganglion cells senescence and treatment in glaucoma.As an irreversible stage before cell death, deeper study on the mechanism of retinal ganglion cells senescence, and specific blocking of cell senescence will provide a new target for reducing the aqueous humor outflow resistance and protecting the optic nerve in glaucoma.This article reviewed characteristics, inducements, molecular signaling pathways of cellular senescence in glaucoma.

Mechanosensitive ion channel Piezo1 induces senescence of atrial fibroblasts by activating β-catenin / 中国药理学通报

Aim To observe whether the mechanosensitive ion channel Piezo1 was involved in the senescence of atrial fibroblasts by activating β-catenin based on our previous study which found marked increase of Piezo1 mRNA in senescent atrial fibroblasts. Methods Primary mouse atrial fibroblasts (MAFs) were isolated from male C57BL/6 mice (3-4 weeks) by enzyme digestion, and tert-butyl hydroperoxide (TBHP) was used to induce the senescence of cells. The ratio of senescent cells was detected by senescence-associated β-galactosidase (SA-β-Gal) staining. The protein levels of Piezo1, β-catenin/p-β-catenin, senescence-associated proteins p53 and p21 in the cells treated with TBHP (100 μmol · L

Dihydroartemisinin attenuates ischemia/reperfusion-induced renal tubular senescence by activating autophagy / 中国天然药物

Acute kidney injury (AKI) is an important factor for the occurrence and development of CKD. The protective effect of dihydroartemisinin on AKI and and reported mechanism have not been reported. In this study, we used two animal models including ischemia-reperfusion and UUO, as well as a high-glucose-stimulated HK-2 cell model, to evaluate the protective effect of dihydroartemisinin on premature senescence of renal tubular epithelial cells in vitro and in vivo. We demonstrated that dihydroartemisinin improved renal aging and renal injury by activating autophagy. In addition, we found that co-treatment with chloroquine, an autophagy inhibitor, abolished the anti-renal aging effect of dihydroartemisinin in vitro. These findings suggested that activation of autophagy/elimination of senescent cell might be a useful strategy to prevent AKI/UUO induced renal tubular senescence and fibrosis.

Role of lysosomal damage in senescence of SH-SY5Y cells induced by methylmercury and intervention of melatonin / 环境与职业医学

Background Methylmercury (MeHg) is a neurotoxin, and melatonin (MT) has a protective effect on the nervous system, but whether it can antagonize MeHg-induced nerve cell damage and the associated mechanism remain unknown. Objective Human neuroblastoma cells (SH-SY5Y cells) were used as research objects. A MeHg-induced SH-SY5Y cell senescence model was established to observe autophagy related protein, lysosomal number, and function changes, as well as potential intervention role and associated mechanism of MT. Methods (1) After SH-SY5Y cells were treated with different doses of MeHg (0, 0.125, 0.25, 0.5, 1, 2, and 4 μmol·L−1) for 48 h, the cell viability was detected using a cell viability detection kit (CCK-8 method) and the viability rate was calculated. Senescent cells were detected by an acidic senescence-associated-β-galactosidase (SA-β-gal) staining. (2) A MeHg dose of 0.5 μmol·L−1 that significantly induced senescence of SH-SY5Y cells was screened, and a half and a quarter of the dose (0.25 and 0.125 μmol·L−1) were used for the middle and low dose groups, respectively. (3) In the MT intervention experiments, SH-SY5Y cells were divided into four groups, including control group (0.1% DMSO), MeHg group (0.5 μmol·L−1 MeHg), MT group (1 mmol·L−1 MT), and MT intervention group (1 mmol·L−1 MT+0.5 μmol·L−1 MeHg). In the MT intervention group, cells were exposed to 0.5 μmol·L−1 MeHg for 48 h after 24 h of 1 mmol·L−1 MT pretreatment. (4) SA-β-gal staining was conducted to observe cell senescence; Western blotting for the expression levels of senescence-associated protein p16, autophagy-associated protein p62, LC3Ⅱ, and lysosomal-associated proteins LAMP1, LAMP2, and TFEB; Lyso-Tracker Red for the quantity of lysosomes; LysoSensor Green DND-189 for lysosomal pH changes; electron microscope for the morphological changes of lysosomes. Results The results of CCK-8 indicated that the viability rate of cells decreased with the increase of MeHg exposure concentration. Compared with the control group, the SA-β-gal positive cell ratio in the 0.5 μmol·L−1 MeHg group increased by 48% (P<0.01), p16, p62, as well as LC3Ⅱ protein expressions were significantly increased (P<0.05), LAMP1 and LAMP2 protein levels, as well as the fluorescence intensities of lysosomal red and green fluorescent probes decreased with the increase of MeHg concentration (P<0.05), and the volume of lysosomes increased under the electron microscope. Compared with the MeHg group, the expression of p16 protein was decreased in the 1 mmol·L−1 MT + 0.5 μmol·L−1 MeHg group and the SA-β-gal positive cell ratio was significantly decreased by 19% (P<0.05), the protein levels of p62 and LC3Ⅱ were significantly decreased, the LAMP1 and LAMP2 protein levels and the fluorescence intensities of lysosomal red and green fluorescent probes were increased respectively, the nuclear entry of TFEB was significantly increased, and the differences were statistically significant (P<0.05). Conclusion MeHg may cause cellular senescence by reducing the number of lysosomes and impairing lysosomal activity in SH-SY5Y cells, and MT may ameliorate MeHg-induced lysosomal abnormalities in SH-SY5Y cells, thereby intervening cell senescence.

Inhibitory Effect of Paeonol on Vascular Smooth Muscle Cell Senescence by Reducing SIRT6/PARP1-mediated DNA Damage / 中国实验方剂学杂志

ObjectiveTo investigate whether the effects of paeonol （Pae） on angiotensin Ⅱ （AngⅡ）-induced senescence in vascular smooth muscle cells （VSMCs） were related to angiotensinogen of silencing regulatory information factor 6 （SIRT6）/adenosine diphosphate ribose polymerase 1 （PARP1） signaling pathway in VSMCs. MethodThe model of VSMC-stress aging induced by AngⅡ （100 nmol·L-1） was established. The rats were divided into normal group， model group， low， medium， and high-concentration Pae groups （30， 60， 120 μmol·L-1）. The positive rate of cell senescence was detected by SA-β-Gal staining， the ability of cell proliferation was detected by the cell counting kit-8 （CCK-8） method， the expression of SIRT6， PARP1， p16， p21， p53， proliferating cell nuclear antigen （PCNA）， deoxyribonucleic acid （DNA）-damaged protein γ-H2AX was detected by Western blot， and VSMC proliferation was detected by EdU staining. The silenced VSMCs were prepared by siRNA-SIRT6 transfection， and the protein expressions of SIRT6， PARP1， p16， and γ-H2AX in VSMCs silenced by SIRT6 were observed. ResultThe results of SA-β-Gal staining showed that the senescence positive rate of SA-β-Gal staining in the model group was higher than that in the normal group （P<0.01）， and the positive rate of SA-β-Gal staining in the Pae group was significantly lower than that in the model group （P<0.05， P<0.01）. The results of Western blot showed that as compared with the normal group， the expression of PCNA， SIRT6， and PARP1 in the model group was down-regulated， and the expression of aging-related proteins p16， p21， p53， and γ-H2AX was up-regulated in the model group （P<0.05， P<0.01）. Compared with the model group， Pae promoted the protein expression of PCNA， SIRT6， and PARP1 and inhibited the protein expression of p16， p21， p53， and γ-H2AX in a dose-dependent manner （P<0.05， P<0.01）. The results of EdU staining showed that the number of EdU positive cells in the model group was lower than that in the normal group （P<0.01）， and the number of EdU positive cells in Pae groups was significantly higher than that in the model group （P<0.05， P<0.01）. After SIRT6 silencing， the effects of Pae on promoting SIRT6 and PARP1 and inhibiting P16 were reversed （P<0.05， P<0.01）. In addition， the addition of SIRT6 inhibitor （IN-1） promoted the occurrence of cell senescence induced by AngⅡ （P<0.05， P<0.01）. ConclusionPae can effectively inhibit the aging of VSMCs， and its mechanism may be related to the regulation of SIRT6/PARP1 signal pathway.