Genetically engineered CD276-anchoring biomimetic nanovesicles target senescent escaped tumor cells to overcome chemoresistant and immunosuppressive breast cancer.

Chemotherapy-induced cellular senescence leads to an increased proportion of cancer stem cells (CSCs) in breast cancer (BC), contributing to recurrence and metastasis, while effective means to clear them are currently lacking. Herein, we aim to develop new approaches for selectively killing senescent-escape CSCs. High CD276 (95.60%) expression in multidrug-resistant BC cells, facilitates immune evasion by low-immunogenic senescent escape CSCs. CALD1, upregulated in ADR-resistant BC, promoting senescent-escape of CSCs with an anti-apoptosis state and upregulating CD276, PD-L1 to promote chemoresistance and immune escape. We have developed a controlled-released thermosensitive hydrogel containing pH- responsive anti-CD276 scFV engineered biomimetic nanovesicles to overcome BC in primary, recurrent, metastatic and abscopal humanized mice models. Nanovesicles coated anti-CD276 scFV selectively fuses with cell membrane of senescent-escape CSCs, then sequentially delivers siCALD1 and ADR due to pH-responsive MnP shell. siCALD1 together with ADR effectively induce apoptosis of CSCs, decrease expression of CD276 and PD-L1, and upregulate MHC I combined with Mn2+ to overcome chemoresistance and promote CD8+T cells infiltration. This combined therapeutic approach reveals insights into immune surveillance evasion by senescent-escape CSCs, offering a promising strategy to immunotherapy effectiveness in cancer therapy.

Metformin represses the carcinogenesis potentially induced by 50 Hz magnetic fields in aged mouse fibroblasts via inhibition of NF-kB.

Aging is a risk factor for various human disorders, including cancer. Current literature advocates that the primary principles of aging depend on the endogenous stress-induced DNA damage caused by reactive oxygen species 50 Hz low-frequency magnetic field was suggested to induce DNA damage and chromosomal instability. NF-kB, activated by DNA damage, is upregulated in age-related cancers and inhibition of NF-kB results in aging-related delayed pathologies. Metformin (Met), an NF-kB inhibitor, significantly reduces both NF-kB activation and expression in aging and cancer. This in vitro study, therefore, was set out to assess the effects of 5mT MF in 50 Hz frequency and Met treatment on the viability and proliferation of aged mouse NIH/3T3 fibroblasts and expression of RELA/p65, matrix metalloproteinases MMP2 and MMP9, and E-cadherin (CDH1) genes. The trypan blue exclusion assay was used to determine cell viability and the BrdU incorporation assay to determine cell proliferation. The MMP-2/9 protein analysis was carried out by immunocytochemistry, NF-kB activity by ELISA and the expressions of targeted genes by qRT-PCR methods. Four doses of Met (500 uM, 1 mM, 2 mM and 10 mM) suppressed both the proliferation and viability of fibroblasts exposed to the MF in a dose-dependent pattern, and the peak inhibition was recorded at the 10 mM dose. Met reduced the expression of NF-kB, and MMP2/9, elevated CDH1 expression and suppressed NF-kB activity. These findings suggest that Met treatment suppresses the carcinogenic potential of 50 Hz MFs in aged mouse fibroblasts, possibly through modulation of NF-kB activation and epithelial-mesenchymal transition modulation.

Pharmacological targeting of P300/CBP reveals EWS::FLI1-mediated senescence evasion in Ewing sarcoma.

Ewing sarcoma (ES) poses a significant therapeutic challenge due to the difficulty in targeting its main oncodriver, EWS::FLI1. We show that pharmacological targeting of the EWS::FLI1 transcriptional complex via inhibition of P300/CBP drives a global transcriptional outcome similar to direct knockdown of EWS::FLI1, and furthermore yields prognostic risk factors for ES patient outcome. We find that EWS::FLI1 upregulates LMNB1 via repetitive GGAA motif recognition and acetylation codes in ES cells and EWS::FLI1-permissive mesenchymal stem cells, which when reversed by P300 inhibition leads to senescence of ES cells. P300-inhibited senescent ES cells can then be eliminated by senolytics targeting the PI3K signaling pathway. The vulnerability of ES cells to this combination therapy suggests an appealing synergistic strategy for future therapeutic exploration.

Deciphering the impact of TERT/telomerase on immunosenescence and T cell revitalization.

Immunosenescence impacts both the innate and adaptive immune systems, predominantly affecting certain immune cell types. A notable manifestation of immunosenescence is the diminished efficacy of adaptive immunity. The excessive senescence of immune cells, particularly T cells, leads to marked immune deficiency, consequently escalating the risk of infections, tumors, and age-associated disorders. Lymphocytes, especially T cells, are subject to both replicative and premature senescence. Telomerase reverse transcriptase (TERT) and telomerase have multifaceted roles in regulating cellular behavior, possessing the ability to counteract both replicative and premature senescence in lymphocytes. This review encapsulates recent advancements in understanding immunosenescence, with a focus on T cell senescence, and the regulatory mechanisms involving TERT/telomerase. Additionally, it comprehensively discusses strategies aimed at inhibiting immunosenescence by augmenting TERT/telomerase activity.

Early detection of cervical tumor cell of origin through Oncogene-induced senescent HPV-positive cells.

Human Papilloma Virus (HPV) is an oncogenic virus and is the most common cause of cervical cancer. HPV has been shown to induce senescence. Cellular senescence is involved in cancer progression and tumorigenesis. Identification and isolation of cells of tumor origin before tumorigeneses is an important step in cancer prevention and treatment. This study aimed to investigate the early cervical atypical senescent cytological preneoplastic change in non-menopausal women. Cervical smears of 121 patients were randomly selected and included in the study which cytopathologically diagnosed as atypical squamous cells of undetermined significance (AS-CUS) in correlation to HPV status, parakeratosis (PK), p16 immunostaining, enlarged Squamous cells nuclei (ES) and inflammatory cells infiltration (ICI). Results revealed that out of the total 121 patients, 32 cases (26%) were positive for high-risk HPV (HR-HPV), 26 cases (22%) were positive for low-risk HPV (LR-HPV) and 63 (52%) were negative for HPV. HPV infections were significantly associated with age groups (p<0.026), PK (p = 0.043), p16 (p = 0.001), ES (p = 0.002) and ICI (p = 0.049). The positive immunostaining expression of p16 was only noticed in two HR-HPV patients. ES cells were found in 9.5% of HPV-negative cases, 27% of LR-HPV cases and 40.5% of HR-HPV cases. High PK cell positivity was seen only in HR-HPV. High ICI scores were seen in 40.6% of HR-HPV patients, 26.9 % of LR-HPV and 17.4 % of negative HPV patients. It was concluded that high PK positivity, high ICI score, positive p16 immunostaining and ES were correlated with HR-HPV in non-menopausal women. These findings could provide potential diagnostic clues for HPV-harboring senescent cells as a strategy for reducing HPV risk of cervical cancer development and identifying the cell of tumor origin, which could be beneficial for improving the utility of senolytic agents and immunotherapy in clinical practice.

Identification of a senescence-related transcriptional signature to uncover molecular subtypes and key genes in hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is a cancer caused by abnormal cell growth due to faulty signal transduction. Cells secrete tumor suppressor factors in response to potential carcinogenic signals, inducing cellular senescence (CS) as a countermeasure. However, accurately measuring CS levels in different types of tumors is challenging due to tumor heterogeneity and the lack of universal and specific CS markers. Machine learning has revealed unique molecular traits in HCC patients, leading to clinical advantages. More research is needed to understand senescence-related molecular features in these patients. In this study, the gene expression profile features of patients with HCC were analyzed by integrating single-cell RNA sequencing and bulk RNA-seq datasets from HCC samples. The analysis identified the senescence-related pathways exhibiting HCC specificity. Subsequently, genes from these pathways were used to identify senescence-related molecular subtypes in HCC, showing significant variations in biological and clinical attributes. An HCC-specific CS risk model developed in this study revealed substantial associations between the patients' CS scores and prognosis grouping, clinical staging, immune infiltration levels, immunotherapy response, and drug sensitivity levels. Within the constructed model, G6PD was identified as a key gene, potentially serving as a senescence-related target in liver cancer. Molecular biology experiments demonstrated that overexpression of G6PD effectively promotes the proliferative, invasive, and migration capacities of HepG2 and SK-HEP-1 cells. In conclusion, this analysis offers a valuable framework for understanding senescence in HCC and introduces a new biomarker. These findings improve our understanding of senescence in HCC and have potential for future research.

Hypomethylation at PANDAR promoter progressively induces senescence in adipocyte precursor cells in subjects with obesity and type 2 diabetes.

The risk of developing type 2 diabetes (T2D) is heterogeneous among individuals with obesity. Functional decline of adipocyte precursor cells (APCs) and accumulation of senescent cells in the subcutaneous adipose tissue contributes to the progression toward T2D. LncRNAs regulate cell senescence and may be implicated in determining this abnormality in APCs. Here, we report that APCs from individuals with obesity show a gradual increase in multiple senescence markers, which worsens in parallel with the progression from normal glucose tolerance (NGT) to impaired glucose tolerance (IGT) or T2D. Transcriptomic analysis identified PANDAR as the top-ranked lncRNA differentially expressed in APCs from individuals with obesity and T2D and non-obese subjects. Q-PCR confirmed PANDAR up-regulation in APCs from individuals with obesity, at progressively increased levels in those who developed, respectively, IGT and T2D. Bisulfite sequencing and luciferase assays revealed that, in parallel with glucose tolerance deterioration, the -1317 CpG at the PANDAR promoter became hypo-methylated in obesity, resulting in enhanced PANDAR induction by p53. PANDAR silencing in senescent APCs from individuals with obesity and T2D caused repression of senescence programs and cell cycle re-entry. PANDAR transcription in white blood cells (WBCs) mirrored that in APCs. Also, individuals with obesity exhibited rescue of PANDAR transcription in WBCs following bariatric surgery, accompanied by enhanced methylation at the regulatory PANDAR -1317 CpG. In conclusion, PANDAR dysregulation is a newly identified mechanism determining the early senescence of APCs from individuals with obesity, which worsens along the progression toward T2D. In the future, PANDAR targeting may represent a valuable strategy to delay this progression.

Senescent cells promote breast cancer cells motility by secreting GM-CSF and bFGF that activate the JNK signaling pathway.

BACKGROUND: Cellular senescence can be induced in mammalian tissues by multiple stimuli, including aging, oncogene activation and loss of tumor suppressor genes, and various types of stresses. While senescence is a tumor suppressing mechanism when induced within premalignant or malignant tumor cells, senescent cells can promote cancer development through increased secretion of growth factors, cytokines, chemokines, extracellular matrix, and degradative enzymes, collectively known as senescence-associated secretory phenotype (SASP). Previous studies indicated that senescent cells, through SASP factors, stimulate tumor cell invasion that is a critical step in cancer cell metastasis. METHODS: In the current study, we investigated the effect of senescent cells on the motility of breast cancer cells, which is another key step in cancer cell metastasis. We analyzed the motility of breast cancer cells co-cultured with senescent cells in vitro and metastasis of the breast cancer cells co-injected with senescent cells in orthotopic xenograft models. We also delineated the signaling pathway mediating the effect of senescent cells on cancer cell motility. RESULTS: Our results indicate that senescent cells stimulated the migration of breast cancer cells through secretion of GM-CSF and bFGF, which in turn induced activation of the JNK pathway in cancer cells. More importantly, senescent cells promoted breast cancer metastasis, with a minimum effect on the primary tumor growth, in orthotopic xenograft mouse models. CONCLUSIONS: These results have revealed an additional mechanism by which senescent cells promote tumor cell metastasis and tumor progression, and will potentially lead to identification of novel targets for cancer therapies that suppress metastasis, the major cause of cancer mortality.

N-Acetyl-L-Cysteine (NAC) Blunts Axitinib-Related Adverse Effects in Preclinical Models of Glioblastoma.

OBJECTIVE: Axitinib is a tyrosine kinase inhibitor characterized by a strong affinity for Vascular Endothelial Growth Factor Receptors (VEGFRs). It was approved in 2012 by Food and Drug Administration and European Medicines Agency as a second line treatment for advanced renal cell carcinoma and is currently under evaluation in clinical trial for the treatment of other cancers. Glioblastoma IDH-wild type (GBM) is a highly malignant brain tumor characterized by diffusely infiltrative growth pattern and by a prominent neo-angiogenesis. In GBM, axitinib has demonstrated a limited effectiveness as a monotherapy, while it was recently shown to significantly improve its efficacy in combination treatments. In preclinical models, axitinib has been reported to trigger cellular senescence both in tumor as well as in normal cells, through a mechanism involving intracellular reactive oxygen species (ROS) accumulation and activation of Ataxia Telangiectasia Mutated kinase (ATM). Limiting axitinib-dependent ROS increase by antioxidants prevents senescence specifically in normal cells, without affecting tumor cells. METHODS: We used brain tumor xenografts obtained by engrafting Glioma Stem Cells (GSCs) into the brain of immunocompromised mice, to investigate the hypothesis that the antioxidant molecule N-Acetyl-L-Cysteine (NAC) might be used to reduce senescence-associated adverse effects of axitinib treatment without altering its anti-tumor activity. RESULTS: We demonstrate that the use of the antioxidant molecule N-Acetyl-Cysteine (NAC) in combination with axitinib stabilizes tumor microvessels in GBM tumor orthotopic xenografts, eventually resulting in vessel normalization, and protects liver vasculature from axitinib-dependent toxicity. CONCLUSION: Overall, we found that NAC co-treatment allows vessel normalization in brain tumor vessels and exerts a protective effect on liver vasculature, therefore minimizing axitinib-dependent toxicity.

Prognostic cellular senescence-related lncRNAs patterns to predict clinical outcome and immune response in colon cancer.

Background: Cellular senescence (CS) is believed to be a major factor in the evolution of cancer. However, CS-related lncRNAs (CSRLs) involved in colon cancer regulation are not fully understood. Our goal was to create a novel CSRLs prognostic model for predicting prognosis and immunotherapy and exploring its potential molecular function in colon cancer. Methods: The mRNA sequencing data and relevant clinical information of GDC TCGA Colon Cancer (TCGA-COAD) were obtained from UCSC Xena platform, and CS-associated genes was acquired from the CellAge website. Pearson correlation analysis was used to identify CSRLs. Then we used Kaplan-Meier survival curve analysis and univariate Cox analysis to acquire prognostic CSRL. Next, we created a CSRLs prognostic model using LASSO and multivariate Cox analysis, and evaluated its prognostic power by Kaplan-Meier and ROC curve analysis. Besides, we explored the difference in tumor microenvironment, somatic mutation, immunotherapy, and drug sensitivity between high-risk and low-risk groups. Finally, we verified the functions of MYOSLID in cell experiments. Results: Three CSRLs (AC025165.1, LINC02257 and MYOSLID) were identified as prognostic CSRLs. The prognostic model exhibited a powerful predictive ability for overall survival and clinicopathological features in colon cancer. Moreover, there was a significant difference in the proportion of immune cells and the expression of immunosuppressive point biomarkers between the different groups. The high-risk group benefited from the chemotherapy drugs, such as Teniposide and Mitoxantrone. Finally, cell proliferation and CS were suppressed after MYOSLID knockdown. Conclusion: CSRLs are promising biomarkers to forecast survival and therapeutic responses in colon cancer patients. Furthermore, MYOSLID, one of 3-CSRLs in the prognostic model, could dramatically regulate the proliferation and CS of colon cancer.

LTF ameliorates cartilage endplate degeneration by suppressing calcification, senescence and matrix degradation through the JAK2/STAT3 pathway.

Intervertebral disc degeneration (IDD)-induced cervical and lumbar herniations are debilitating diseases. The function of intervertebral disc (IVD) mainly depends on the cartilage endplate (CEP), which provides support and waste removal. Therefore, IDD stems from the degeneration of CEP. Our study shows that the expression of lactotransferrin (LTF), an iron-binding protein, is significantly decreased in degenerated human and rat CEP tissues. In addition, we found that LTF knockdown promoted calcification, senescence, and extracellular matrix (ECM) degradation in human endplate chondrocytes. Furthermore, the in vivo experiment results confirmed that the JAK2/STAT3 pathway inhibitor AG490 significantly reversed these effects. In addition to investigating the role and mechanism of LTF in CEP degeneration, this study provides a theoretical basis and experimental evidence to improve IDD treatment.

ALKBH5 regulates etoposide-induced cellular senescence and osteogenic differentiation in osteoporosis through mediating the m6A modification of VDAC3.

Osteoporosis, a common bone disease in older individuals, involves the progression influenced by N6-methyladenosine (m6A) modification. This study aimed to elucidate the effects of VDAC3 m6A modification on human bone mesenchymal stromal cell (BMSC) senescence and osteogenic differentiation. BMSCs were treated with etoposide to induce senescence. Senescence was assessed by ß-galactosidase staining and quantitative real-time PCR (qPCR), and osteogenic differentiation was evaluated using Western blot, alkaline phosphatase, and alizarin red S staining. VDAC3 and ALKBH5 expression were quantified by qPCR, and their interaction was assessed by RNA immunoprecipitation (RIP) and luciferase reporter assay. m6A methylation was analyzed using the Me-RIP assay. VDAC3 expression was significantly decreased in etoposide-treated BMSCs (1.00 ± 0.13 vs. 0.26 ± 0.06). VDAC3 overexpression reduced etoposide-induced senescence and promoted osteogenic differentiation. ALKBH5 overexpression inhibited VDAC3 m6A modification (1.00 ± 0.095 vs. 0.233 ± 0.177) and its stability. ALKBH5 knockdown decreased etoposide-induced senescence and promoted osteogenic differentiation, effects that were reversed by VDAC3 knockdown. YTHDF1 was identified as the m6A methylation reader, and its overexpression inhibited VDAC3 stability. We demonstrated that ALKBH5 inhibited osteogenic differentiation of etoposide-induced senescent cells through the inhibition of VDAC3 m6A modification, and YTHDF1 acted as the m6A methylation reader. These findings provide a novel theoretical basis for the treatment of osteoporosis.

Cellular senescence by loss of Men1 in osteoblasts is critical for age-related osteoporosis.

Recent evidence suggests an association between age-related osteoporosis and cellular senescence in the bone; however, the specific bone cells that play a critical role in age-related osteoporosis and the mechanism remain unknown. Results revealed that age-related osteoporosis is characterized by the loss of osteoblast Men1. Osteoblast-specific inducible knockout of Men1 caused structural changes in the mice bones, matching the phenotypes in patients with age-related osteoporosis. Histomorphometrically, Men1-knockout mice femurs decreased osteoblastic activity and increased osteoclastic activity, hallmarks of age-related osteoporosis. Loss of Men1 induces cellular senescence via mTORC1 activation and AMPK suppression, rescued by metformin treatment. In bone morphogenetic protein-indued bone model, loss of Men1 leads to accumulation of senescent cells and osteoporotic bone formation, which are ameliorated by metformin. Our results indicate that cellular senescence in osteoblasts plays a critical role in age-related osteoporosis and that osteoblast-specific inducible Men1-knockout mice offer a promising model for developing therapeutics for age-related osteoporosis.

Lens capsule advanced glycation end products induce senescence in epithelial cells: Implications for secondary cataracts.

Posterior capsule opacification (PCO) is a common complication after cataract surgery. Residual lens epithelial cells (LECs) on the anterior lens capsule, after cataract surgery, migrate to the posterior lens capsule and undergo transdifferentiation into myofibroblast-like cells. Those cells synthesize excessive amounts of extracellular matrix and contribute to fibrosis during PCO. Cellular senescence, a phenomenon that increases with aging, has been implicated in several fibrotic diseases. Here, we have investigated the prevalence of senescent LECs within the lens posterior capsule and the ability of advanced glycation end products (AGEs) in lens capsules to induce senescence, contributing to PCO. Aged lens capsules from pseudophakic human cadaver eyes showed the presence of senescent LECs. In human capsular bags, LECs showed an age-dependent increase in senescence after 28 days of culture. Human LECs cultured on aged lens capsules for 3 days underwent senescence; this effect was not seen in LECs cultured on young lens capsules. Human LECs cultured on an AGE-modified extracellular matrix (ECM-AGEs) showed an AGE-concentration-dependent increase in the expression of senescence markers and reactive oxygen species (ROS) levels. Treatment with a RAGE antagonist and ROS inhibitor reduced the expression of senescence and fibrotic markers. Additionally, conditioned media from ECM-AGEs-treated cells induced the expression of fibrotic markers in naïve LECs. Together, these suggest that AGEs in the capsule induce senescence of LECs, which triggers the mesenchymal transition of neighboring non-senescent LECs and contributes to PCO.

MG-132 activates sodium palmitate-induced autophagy in human vascular smooth muscle cells and inhibits senescence via the PI3K/AKT/mTOR axis.

OBJECTIVE: This study aimed to reveal the role and mechanism of MG-132 in delaying hyperlipidemia-induced senescence of vascular smooth muscle cells (VSMCs). METHODS: Immunohistochemistry and hematoxylin-eosin staining confirmed the therapeutic effect of MG-132 on arterial senescence in vivo and its possible mechanism. Subsequently, VSMCs were treated with sodium palmitate (PA), an activator (Recilisib) or an inhibitor (Pictilisib) to activate or inhibit PI3K, and CCK-8 and EdU staining, wound healing assays, Transwell cell migration assays, autophagy staining assays, reactive oxygen species assays, senescence-associated ß-galactosidase staining, and Western blotting were performed to determine the molecular mechanism by which MG-132 inhibits VSMC senescence. Validation of the interaction between MG-132 and PI3K using molecular docking. RESULTS: Increased expression of p-PI3K, a key protein of the autophagy regulatory system, and decreased expression of the autophagy-associated proteins Beclin 1 and ULK1 were observed in the aortas of C57BL/6J mice fed a high-fat diet (HFD), and autophagy was inhibited in aortic smooth muscle. MG-132 inhibits atherosclerosis by activating autophagy in VSMCs to counteract PA-induced cell proliferation, migration, oxidative stress, and senescence, thereby inhibiting VSMC senescence in the aorta. This process is achieved through the PI3K/AKT/mTOR signaling pathway. CONCLUSION: MG-132 activates autophagy by inhibiting the PI3K/AKT/mTOR pathway, thereby inhibiting palmitate-induced proliferation, migration, and oxidative stress in vascular smooth muscle cells and suppressing their senescence.

IL-10 deficiency aggravates cell senescence and accelerates BLM-induced pulmonary fibrosis in aged mice via PTEN/AKT/ERK pathway.

BACKGROUND: Pulmonary fibrosis (PF) is an aging-related progressive lung disorder. The aged lung undergoes functional and structural changes termed immunosenescence and inflammaging, which facilitate the occurrence of fibrosis. Interleukin-10 (IL-10) is a potent anti-inflammatory and immunoregulatory cytokine, yet it remains unclear how IL-10 deficiency-induced immunosenescence participates in the development of PF. METHODS: Firstly we evaluated the susceptibility to fibrosis and IL-10 expression in aged mice. Then 13-month-old wild-type (WT) and IL-10 knockout (KO) mice were subjected to bleomycin(BLM) and analyzed senescence-related markers by PCR, western blot and immunohistochemistry staining of p16, p21, p53, as well as DHE and SA-ß-gal staining. We further compared 18-month-old WT mice with 13-month-old IL-10KO mice to assess aging-associated cell senescence and inflamation infiltration in both lung and BALF. Moreover, proliferation and apoptosis of alveolar type 2 cells(AT2) were evaluated by FCM, immunofluorescence, TUNEL staining, and TEM analysis. Recombinant IL-10 (rIL-10) was also administered intratracheally to evaluate its therapeutic potential and related mechanism. For the in vitro experiments, 10-week-old naïve pramily lung fibroblasts(PLFs) were treated with the culture medium of 13-month PLFs derived from WT, IL-10KO, or IL-10KO + rIL-10 respectively, and examined the secretion of senescence-associated secretory phenotype (SASP) factors and related pathways. RESULTS: The aged mice displayed increased susceptibility to fibrosis and decreased IL-10 expression. The 13-month-old IL-10KO mice exhibited significant exacerbation of cell senescence compared to their contemporary WT mice, and even more severe epithelial-mesenchymal transition (EMT) than that of 18 month WT mice. These IL-10 deficient mice showed heightened inflammatory responses and accelerated PF progression. Intratracheal administration of rIL-10 reduced lung CD45 + cell infiltration by 15%, including a 6% reduction in granulocytes and a 10% reduction in macrophages, and increased the proportion of AT2 cells by approximately 8%. Additionally, rIL-10 significantly decreased α-SMA and collagen deposition, and reduced the expression of senescence proteins p16 and p21 by 50% in these mice. In vitro analysis revealed that conditioned media from IL-10 deficient mice promoted SASP secretion and upregulated senescence genes in naïve lung fibroblasts, which was mitigated by rIL-10 treatment. Mechanistically, rIL-10 inhibited TGF-ß-Smad2/3 and PTEN/PI3K/AKT/ERK pathways, thereby suppressing senescence and fibrosis-related proteins. CONCLUSIONS: IL-10 deficiency in aged mice leads to accelerated cell senescence and exacerbated fibrosis, with IL-10KO-PLFs displaying increased SASP secretion. Recombinant IL-10 treatment effectively mitigates these effects, suggesting its potential as a therapeutic target for PF.

Exploring the molecular and immune landscape of cellular senescence in lung adenocarcinoma.

Introduction: The connection between aging and cancer is complex. Previous research has highlighted the association between the aging process of lung adenocarcinoma (LUAD) cells and the immune response, yet there remains a gap in confirming this through single-cell data validation. Here, we aim to develop a novel aging-related prognostic model for LUAD, and verify the alterations in the genome and immune microenvironment linked to cellular senescence. Methods: We integrated a comprehensive collection of senescence genes from the GenAge and CellAge databases and employed the least absolute shrinkage and selection operator (LASSO) Cox analysis to construct and validate a novel prognostic model for LUAD. This model was then utilized to examine the relationship between aging, tumor somatic mutations, and immune cell infiltration. Additionally, we explored the heterogeneity of senescence and intercellular communication within the LUAD tumor microenvironment (TME) through single-cell transcriptomic data analysis. Results: By exploring the expression profiles of 586 cellular senescence-related genes in 428 LUAD patients, we constructed an aging-related genes (ARGs) risk model included 10 ARGs and validated it as an independent prognostic predictor for LUAD patients. Notably, patients with low aging scores (LAS group) exhibited better survival, lower tumor mutation burden (TMB), lower somatic mutation frequency, lower tumor proliferation rate, and an immune activated phenotype compared to patients with high aging scores (HAS group). While the HAS group was enriched in tumor cells and showed a lower infiltration of CD8-CCR7, CD8- CXCL13, CD8-GNLY, FCGR3A NK cells, XCL1 NK cells, plasma cell (PC) and other immune subsets. Furthermore, the SPP1 and TENASCIN pathways, associated with tumor immune escape and tumor progression, were also enriched in the HAS group. Additionally, our study also indicated that senescence levels were heterogeneous in the LUAD tumor microenvironment (TME), especially with tumor cells in the LAS group showing higher age scores compared to those in the HAS group. Conclusions: Collectively, our findings underscore that ARRS through ARGs serves as a robust biomarker for the prognosis in LUAD.

SIRT6 alleviates senescence induced by Porphyromonas gingivalis in human gingival fibroblasts.

OBJECTIVE: Bidirectional influences between senescence and inflammation are newly discovered. This study aimed to clarify the roles and mechanism of Porphyromonas gingivalis (P. gingivalis) in exacerbating senescence in human gingival fibroblasts (HGFs). DESIGN: Subgingival plaque and gingivae were collected from twenty-four periodontitis patients and eighteen periodontally healthy subjects. Quantities of P. gingivalis in subgingival plaque were explored using real-time PCR and the expressions of p53, p21 and SIRT6 in gingivae were detected by IHC. Moreover, senescence in HGFs was induced by P. gingivalis lipopolysaccharide (LPS) and the expressions of senescence-related ß-galactosidase (SA-ß-gal), p53, p21 and senescence-associated secretory phenotype (IL-6 and IL-8) with or without treatment by SIRT6 activator UBCS039 were explored by IHC, western blot and ELISA, respectively. In addition, the levels of SIRT6, Nrf2, HO-1 and reactive oxygen species (ROS) were examined by western blot and flow cytometry. RESULTS: Quantities of P. gingivalis in subgingival plaque and semi-quantitative scores of p53 and p21 in gingivae of periodontitis patients were increased compared with healthy controls (p < 0.05), while SIRT6 score in periodontitis patients was decreased (p < 0.001). Quantities of P. gingivalis were positively correlated with p53 and p21 scores (0.6 < r < 0.9, p < 0.01), and negatively correlated with SIRT6 score (-0.9 < r<-0.6, p < 0.01). Moreover, P. gingivalis LPS increased the levels of SA-ß-gal, p53, p21, IL-6, IL-8 and ROS and decreased the levels of SIRT6, Nrf2 and HO-1 in HGFs, which was rescued by UBCS039 (p < 0.05). CONCLUSIONS: P. gingivalis LPS could induce senescence of HGFs, which could be reversed by SIRT6 via Nrf2-HO-1 signaling pathway.

Curcumin Inhibits TORC1 and Prolongs the Lifespan of Cells with Mitochondrial Dysfunction.

Aging is an inevitable biological process that contributes to the onset of age-related diseases, often as a result of mitochondrial dysfunction. Understanding the mechanisms behind aging is crucial for developing therapeutic interventions. This study investigates the effects of curcumin on postmitotic cellular lifespan (PoMiCL) during chronological aging in yeast, a widely used model for human postmitotic cellular aging. Our findings reveal that curcumin significantly prolongs the PoMiCL of wildtype yeast cells, with the most pronounced effects observed at lower concentrations, indicating a hormetic response. Importantly, curcumin also extends the lifespan of postmitotic cells with mitochondrial deficiencies, although the hormetic effect is absent in these defective cells. Mechanistically, curcumin inhibits TORC1 activity, enhances ATP levels, and induces oxidative stress. These results suggest that curcumin has the potential to modulate aging and offer therapeutic insights into age-related diseases, highlighting the importance of context in its effects.

An unscheduled switch to endocycles induces a reversible senescent arrest that impairs growth of the Drosophila wing disc.

A programmed developmental switch to G / S endocycles results in tissue growth through an increase in cell size. Unscheduled, induced endocycling cells (iECs) promote wound healing but also contribute to cancer. Much remains unknown, however, about how these iECs affect tissue growth. Using the D. melanogaster wing disc as model, we find that populations of iECs initially increase in size but then subsequently undergo a heterogenous arrest that causes severe tissue undergrowth. iECs acquired DNA damage and activated a Jun N-terminal kinase (JNK) pathway, but, unlike other stressed cells, were apoptosis-resistant and not eliminated from the epithelium. Instead, iECs entered a JNK-dependent and reversible senescent-like arrest. Senescent iECs promoted division of diploid neighbors, but this compensatory proliferation did not rescue tissue growth. Our study has uncovered unique attributes of iECs and their effects on tissue growth that have important implications for understanding their roles in wound healing and cancer.