Characteristics and mechanisms of T-cell senescence: A potential target for cancer immunotherapy.

Immunosenescence, the aging of the immune system, leads to functional deficiencies, particularly in T cells, which undergo significant changes. While numerous studies have investigated age-related T-cell phenotypes in healthy aging, senescent T cells have also been observed in younger populations during pathological conditions like cancer. This review summarizes the recent advancements in age-associated alterations and markers of T cells, mechanisms, and the relationship between senescent T cells and the tumor microenvironment. We also discuss potential strategies for targeting senescent T cells to prevent age-related diseases and enhance tumor immunotherapy efficacy.

Senescence of Hepatic Stellate Cells by Specific Delivery of Manganese for Limiting Liver Fibrosis.

Senescence of activated hepatic stellate cells (HSCs) is crucial for the regression of liver fibrosis. However, impaired immune clearance can result in the accumulation of senescent HSCs, exacerbating liver fibrosis. The activation of the cyclic GMP-AMP synthase-stimulator of interferon genes (cGAS-STING) pathway is essential for both senescence and the innate immune response. Additionally, the specific delivery to activated HSCs is hindered by their inaccessible anatomical location, capillarization of liver sinusoidal endothelial cells (LSECs), and loss of substance exchange. Herein, we propose an antifibrotic strategy that combines prosenescence with enhanced immune clearance through targeted delivery of manganese (a cGAS-STING stimulator) via albumin-mediated transcytosis, specifically aimed at inducing senescence and eliminating activated HSCs in liver fibrosis. Our findings demonstrate that only albumin efficiently transfers manganese to activated HSCs from LSECs via transcytosis compared to liposomes, resulting in significant antifibrotic effects in vivo while exhibiting negligible toxicity.

Identification of senescent cell surface targetable protein DPP4.

Senescent cell accumulation in aging tissues is linked to age-associated diseases and declining function, prompting efforts to eliminate them. Mass spectrometry analysis revealed that DPP4 (dipeptidyl peptidase 4) was selectively expressed on the surface of senescent, but not proliferating, human diploid fibroblasts. Importantly, the differential presence of DPP4 allowed flow cytometry-mediated isolation of senescent cells using anti-DPP4 antibodies. Moreover, antibody-dependent cell-mediated cytotoxicity (ADCC) assays revealed that the cell surface DPP4 preferentially sensitized senescent, but not dividing, fibroblasts to cytotoxicity by natural killer cells. In sum, the selective expression of DPP4 on the surface of senescent cells enables their preferential elimination.

Cholesterol-induced HRD1 reduction accelerates vascular smooth muscle cell senescence via stimulation of endoplasmic reticulum stress-induced reactive oxygen species.

Senescence of vascular smooth muscle cells (VSMCs) is a key contributor to plaque vulnerability in atherosclerosis (AS), which is affected by endoplasmic reticulum (ER) stress and reactive oxygen species (ROS) production. However, the crosstalk between ER stress and ROS production in the pathogenesis of VSMC senescence remains to be elucidated. ER-associated degradation (ERAD) is a complex process that clears unfolded or misfolded proteins to maintain ER homeostasis. HRD1 is the major E3 ligase in mammalian ERAD machineries that catalyzes ubiquitin conjugation to the unfolded or misfolded proteins for degradation. Our results showed that HRD1 protein levels were reduced in human AS plaques and aortic roots from ApoE-/- mice fed with high-fat diet (HFD), along with the increased ER stress response. Exposure to cholesterol in VSMCs activated inflammatory signaling and induced senescence, while reduced HRD1 protein expression. CRISPR Cas9-mediated HRD1 knockout (KO) exacerbated cholesterol- and thapsigargin-induced cell senescence. Inhibiting ER stress with 4-PBA (4-Phenylbutyric acid) partially reversed the ROS production and cell senescence induced by HRD1 deficiency in VSMCs, suggesting that ER stress alone could be sufficient to induce ROS production and senescence in VSMCs. Besides, HRD1 deficiency led to mitochondrial dysfunction, and reducing ROS production from impaired mitochondria partly reversed HRD1 deficiency-induced cell senescence. Finally, we showed that the overexpression of HDR1 reversed cholesterol-induced ER stress, ROS production, and cellular senescence in VSMCs. Our findings indicate that HRD1 protects against senescence by maintaining ER homeostasis and mitochondrial functionality. Thus, targeting HRD1 function may help to mitigate VSMC senescence and prevent vascular aging related diseases. TRIAL REGISTRATION: A real-world study based on the discussion of primary and secondary prevention strategies for coronary heart disease, URL:https://www.clinicaltrials.gov, the trial registration number is [2022]-02-121-01.

Permissive role of vascular endothelium in fibrosis: focus on the kidney.

Fibrosis, the morphologic end-result of a plethora of chronic conditions and the scorch for organ function, has been thoroughly investigated. One aspect of its development and progression, namely the permissive role of vascular endothelium, has been overshadowed by studies into (myo)fibroblasts and TGF-ß; thus, it is the subject of the present review. It has been established that tensile forces of the extracellular matrix acting on cells are a prerequisite for mechanochemical coupling, leading to liberation of TGF-ß and formation of myofibroblasts. Increased tensile forces are prompted by elevated vascular permeability in response to diverse stressors, resulting in the exudation of fibronectin, fibrinogen/fibrin, and other proteins, all stiffening the extracellular matrix. These processes lead to the development of endothelial cells dysfunction, endothelial-to-mesenchymal transition, premature senescence of endothelial cells, perturbation of blood flow, and gradual obliteration of microvasculature, leaving behind "string" vessels. The resulting microvascular rarefaction is not only a constant companion of fibrosis but also an adjunct mechanism of its progression. The deepening knowledge of the above chain of pathogenetic events involving endothelial cells, namely increased permeability-stiffening of the matrix-endothelial dysfunction-microvascular rarefaction-tissue fibrosis, may provide a roadmap for therapeutic interventions deemed to curtail and reverse fibrosis.

Gastrodin alleviates premature senescence of vascular endothelial cells by enhancing the Nrf2/HO-1 signalling pathway.

Endothelial dysfunction is an independent risk factor for stroke. The dysfunction of endothelial cells (EC) is closely concerned with EC senescence. Gastrodin (GAS) is an organic compound extracted from the dried root mass of the Orchidaceae plant Gastrodiae gastrodiae. It is used clinically to treat diseases such as vertebrobasilar insufficiency, vestibular neuronitis and vertigo. In the present study, we used hydrogen peroxide (H2 O2 )-induced human umbilical vein endothelial cells (HUVECs) to establish an in vitro EC senescence model and to investigate the role and mechanism of GAS in EC senescence. It's found that H2 O2 -treated HUVECs increased the proportion of senescence-associated ß-galactosidase (SA ß-gal) positive cells and the relative protein expression levels of senescence-associated cyclin p16 and p21. In addition, GAS reduced the proportion of SA ß-gal positive cells and the relative protein expression levels of p16 and p21, and increased the proliferation and migration ability of HUVECs. Meanwhile, GAS increased the expression of the anti-oxidative stress protein HO-1 and its nuclear expression level of Nrf2. The anti-senescence effect of GAS was blocked when HO-1 expression was inhibited by SnPPIX. Furthermore, absence of HO-1 abolished the effect of GAS on HUVEC proliferation and migration. In conclusion, GAS ameliorated H2 O2 -induced cellular senescence and enhanced cell proliferation and migration by enhancing Nrf2/HO-1 signalling in HUVECs. These findings of our study expanded the understanding of GAS pharmacology and suggested that GAS may offer a potential therapeutic agent for stroke.

C-X-C chemokine receptor type 4 promotes tubular cell senescence and renal fibrosis through ß-catenin-inhibited fatty acid oxidation.

The prevalence of chronic kidney disease (CKD) is highly increasing. Renal fibrosis is a common pathological feature in various CKD. Previous studies showed tubular cell senescence is highly involved in the pathogenesis of renal fibrosis. However, the inducers of tubular senescence and the underlying mechanisms have not been fully investigated. C-X-C motif chemokine receptor 4 (CXCR4), a G-protein-coupled seven-span transmembrane receptor, increases renal fibrosis and plays an important role in tubular cell injury. Whereas, whether CXCR4 could induce tubular cell senescence and the detailed mechanisms have not studied yet. In this study, we adopted adriamycin nephropathy and 5/6 nephrectomy models, and cultured tubular cell line. Overexpression or knockdown of CXCR4 was obtained by injection of related plasmids. We identified CXCR4 increased in injury tubular cells. CXCR4 was expressed predominantly in renal tubular epithelial cells and co-localized with adipose differentiation-related protein (ADRP) as well as the senescence-related protein P16INK4A . Furthermore, we found overexpression of CXCR4 greatly induced the activation of ß-catenin, while knockdown of CXCR4 inhibited it. We also found that CXCR4 inhibited fatty acid oxidation and triggered lipid deposition in tubular cells. To inhibit ß-catenin by ICG-001, an inhibitor of ß-catenin, could significantly block CXCR4-suppressed fatty acid oxidation. Taken together, our results indicate that CXCR4 is a key mediator in tubular cell senescence and renal fibrosis. CXCR4 promotes tubular cell senescence and renal fibrosis by inducing ß-catenin and inhibiting fatty acid metabolism. Our findings provide a new theory for tubular cell injury in renal fibrosis.

PBA2, a novel inhibitor of the ß-catenin/CBP pathway, eradicates chronic myeloid leukemia including BCR-ABL T315I mutation.

BACKGROUND: BCR-ABL is a constitutively active tyrosine kinase that stimulates multiple downstream signaling pathways to promote the survival and proliferation of chronic myeloid leukemia (CML) cells. The clinical application of specific BCR-ABL tyrosine kinase inhibitors (TKIs) has led to significantly improved prognosis and overall survival in CML patients compared to previous treatment regimens. However, direct targeting of BCR-ABL does not eradicate CML cells expressing T315I-mutated BCR-ABL. Our previous study revealed that inhibiting CREB binding protein (CBP) is efficacious in activating ß-catenin/p300 signaling, promoting cell differentiation and inducing p53/p21-dependent senescence regardless of BCR-ABL mutation status. We hypothesize that the specific inhibition of CBP may represent a novel strategy to promote ß-catenin/p300-mediated differentiation and suppress cancer cell proliferation for treating CML patients. METHODS: The anticancer efficacy of PBA2, a novel CBP inhibitor, in CML cells expressing wild-type or T315I-mutated BCR-ABL was investigated in vitro and in vivo. Cell differentiation was determined by the nitroblue tetrazolium (NBT) reduction assay. The extent of cellular senescence was assessed by senescence-associated ß-galactosidase (SA-ß-Gal) activity. Cytotoxicity was measured by MTS assay. RNA interference was performed to evaluate the cell proliferation effects of CBP knockdown. The interaction of ß-catenin and CBP/p300 was examined by co-immunoprecipitation assay. RESULTS: PBA2 exhibited significantly higher anticancer effects than imatinib in CML cells harboring either wild-type or T315I-mutated BCR-ABL both in vitro and in vivo. Mechanistically, PBA2 reduced CBP expression and promoted ß-catenin-p300 interaction to induce cell differentiation and senescence. CONCLUSION: Our data supported the rational treatment of CML by inhibiting the ß-catenin/CBP pathway regardless of BCR-ABL mutation status.

Dysregulated lipid metabolism and intervertebral disc degeneration: the important role of ox-LDL/LOX-1 in endplate chondrocyte senescence and calcification.

BACKGROUND: Lipid metabolism disorders are associated with degeneration of multiple tissues and organs, but the mechanism of crosstalk between lipid metabolism disorder and intervertebral disc degeneration (IDD) has not been fully elucidated. In this study we aim to investigate the regulatory mechanism of abnormal signal of lipid metabolism disorder on intervertebral disc endplate chondrocyte (EPC) senescence and calcification. METHODS: Human intervertebral disc cartilage endplate tissue, cell model and rat hyperlipemia model were performed in this study. Histology and immunohistochemistry were used to human EPC tissue detection. TMT-labelled quantitative proteomics was used to detect differential proteins, and MRI, micro-CT, safranin green staining and immunofluorescence were performed to observe the morphology and degeneration of rat tail intervertebral discs. Flow cytometry, senescence-associated ß-galactosidase staining, alizarin red staining, alkaline phosphatase staining, DCFH-DA fluorescent probe, and western blot were performed to detect the expression of EPC cell senescence, senescence-associated secretory phenotype, calcification-related proteins and the activation of cell senescence-related signaling pathways. RESULTS: Our study found that the highly expressed oxidized low-density lipoprotein (ox-LDL) and Lectin-like oxidized low-density lipoprotein receptor 1 (LOX-1) in human degenerative EPC was associated with hyperlipidemia (HLP). TMT-labelled quantitative proteomics revealed enriched pathways such as cell cycle regulation, endochondral bone morphogenesis and inflammation. The rat model revealed that HLP could induce ox-LDL, LOX-1, senescence and calcification markers high expression in EPC. Moreover, we demonstrated that ox-LDL-induced EPCs senescence and calcification were dependent on the LOX-1 receptor, and the ROS/P38-MAPK/NF-κB signaling pathway was implicated in the regulation of senescence induced by ox-LDL/LOX-1 in cell model. CONCLUSIONS: So our study revealed that ox-LDL/LOX-1-induced EPCs senescence and calcification through ROS/P38-MAPK/NF-κB signaling pathway, providing information on understanding the link between lipid metabolism disorders and IDD.

Senescence-Targeted and NAD+-Dependent SIRT1-Activated Nanoplatform to Counteract Stem Cell Senescence for Promoting Aged Bone Regeneration.

Age-related bone defects are a leading cause of disability and mortality in elderly individuals, and targeted therapy to delay the senescence of bone marrow-derived mesenchymal stem cells (MSCs) has emerged as a promising strategy to rejuvenate bone regeneration in aged scenarios. More specifically, activating the nicotinamide adenine dinucleotide (NAD+)-dependent sirtuin 1 (SIRT1) pathway is demonstrated to effectively counteract MSC senescence and thus promote osteogenesis. Herein, based on an inventively identified senescent MSC-specific surface marker Kremen1, a senescence-targeted and NAD+ dependent SIRT1 activated nanoplatform is fabricated with a dual delivery of resveratrol (RSV) (SIRT1 promoter) and nicotinamide riboside (NR, NAD+ precursor). This targeting nanoplatform exhibits a strong affinity for senescent MSCs through conjugation with anti-Kremen1 antibodies and enables specifically responsive release of NR and RSV in lysosomes via senescence-associated ß-galactosidase-stimulated enzymatic hydrolysis of the hydrophilic chain. Furthermore, this nanoplatform performs well in promoting aged bone formation both in vitro and in vivo by boosting NAD+, activating SIRT1, and delaying MSC senescence. For the first time, a novel senescent MSC-specific surface marker is identified and aged bone repair is rejuvenated by delaying senescence of MSCs using an active targeting platform. This discovery opens up new insights for nanotherapeutics aimed at age-related diseases.

USP14 inhibition promotes DNA damage repair and represses ovarian granulosa cell senescence in premature ovarian insufficiency.

BACKGROUND: Premature ovarian insufficiency (POI) is a condition characterized by a substantial decline or loss of ovarian function in women before the age of 40. However, the pathogenesis of POI remains to be further elucidated, and specific targeted drugs which could delay or reverse ovarian reserve decline are urgently needed. Abnormal DNA damage repair (DDR) and cell senescence in granulosa cells are pathogenic mechanisms of POI. Ubiquitin-specific protease 14 (USP14) is a key enzyme that regulates the deubiquitylation of DDR-related proteins, but whether USP14 participates in the pathogenesis of POI remains unclear. METHODS: We measured USP14 mRNA expression in granulosa cells from biochemical POI (bPOI) patients. In KGN cells, we used IU1 and siRNA-USP14 to specifically inhibit USP14 and constructed a cell line stably overexpressing USP14 to examine its effects on DDR function and cellular senescence in granulosa cells. Next, we explored the therapeutic potential of IU1 in POI mouse models induced by D-galactose. RESULTS: USP14 expression in the granulosa cells of bPOI patients was significantly upregulated. In KGN cells, IU1 treatment and siUSP14 transfection decreased etoposide-induced DNA damage levels, promoted DDR function, and inhibited cell senescence. USP14 overexpression increased DNA damage, impaired DDR function, and promoted cell senescence. Moreover, IU1 treatment and siUSP14 transfection increased nonhomologous end joining (NHEJ), upregulated RNF168, Ku70, and DDB1, and increased ubiquitinated DDB1 levels in KGN cells. Conversely, USP14 overexpression had the opposite effects. Intraperitoneal IU1 injection alleviated etoposide-induced DNA damage in granulosa cells, ameliorated the D-galactose-induced POI phenotype, promoted DDR, and inhibited cell senescence in ovarian granulosa cells in vivo. CONCLUSIONS: Upregulated USP14 in ovarian granulosa cells may play a role in POI pathogenesis, and targeting USP14 may be a potential POI treatment strategy. Our study provides new insights into the pathogenesis of POI and a novel POI treatment strategy.

Safeguarding genomic integrity in beta-cells: implications for beta-cell differentiation, growth, and dysfunction.

The maintenance of optimal glucose levels in the body requires a healthy reserve of the insulin producing pancreatic beta-cells. Depletion of this reserve due to beta-cell dysfunction and death results in development of diabetes. Recent findings highlight unresolved DNA damage as a key contributor to beta-cell defects in diabetes. Beta-cells face various stressors and metabolic challenges throughout life, rendering them susceptible to DNA breaks. The post-mitotic, long-lived phenotype of mature beta-cells further warrants robust maintenance of genomic integrity. Failure to resolve DNA damage during beta-cell development, therefore, can result in an unhealthy reserve of beta-cells and predispose to diabetes. Yet, the molecular mechanisms safeguarding beta-cell genomic integrity remain poorly understood. Here, we focus on the significance of DNA damage in beta-cell homeostasis and postulate how cellular expansion, epigenetic programming, and metabolic shifts during development may impact beta-cell genomic integrity and health. We discuss recent findings demonstrating a physiological role for DNA breaks in modulating transcriptional control in neurons, which share many developmental programs with beta-cells. Finally, we highlight key gaps in our understanding of beta-cell genomic integrity and discuss emerging areas of interest.

Age-related bone diseases: Role of inflammaging.

Bone aging is characterized by an imbalance in the physiological and pathological processes of osteogenesis, osteoclastogenesis, adipogenesis, and chondrogenesis, resulting in exacerbated bone loss and the development of age-related bone diseases, including osteoporosis, osteoarthritis, rheumatoid arthritis, and periodontitis. Inflammaging, a novel concept in the field of aging research, pertains to the persistent and gradual escalation of pro-inflammatory reactions during the aging process. This phenomenon is distinguished by its low intensity, systemic nature, absence of symptoms, and potential for management. The mechanisms by which inflammaging contribute to age-related chronic diseases, particularly in the context of age-related bone diseases, remain unclear. The precise manner in which systemic inflammation induces bone aging and consequently contributes to the development of age-related bone diseases has yet to be fully elucidated. This article primarily examines the mechanisms underlying inflammaging and its association with age-related bone diseases, to elucidate the potential mechanisms of inflammaging in age-related bone diseases and offer insights for developing preventive and therapeutic strategies for such conditions.

Shelterin dysfunction promotes CD4+ T cell senescence in Behçet's disease.

OBJECTIVES: To investigate the potential role of shelterin dysfunction in naïve CD4+ T cells in the pathogenesis of Behçet's disease (BD). METHODS: Naïve CD4+ T cells were isolated from 40 BD patients and 40 sex- and age-matched healthy controls (HC). Senescent profiles, shelterin subunits expression, telomere length, telomerase activity and critical DNA damage response (DDR) were evaluated. Telomere repeat factor-2 (TRF2) silencing was conducted for further validation. RESULTS: Compared with HC, BD patients had significantly decreased naïve CD4+ T cells, increased cell apoptosis, senescence, and productions of TNF-α and IFN-γ upon activation. Notably, BD naïve CD4+ T cells had shortened telomere, impaired telomerase activity, and expressed lower levels of shelterin subunits TRF2, TRF1- and TRF2-Interacting Nuclear Protein 2 (TIN2) and Repressor/Activator Protein 1 (RAP1). Furthermore, BD naïve CD4+ T cells exhibited significantly increased DDR, evidenced by elevated phosphorylated ataxia telangiectasia (AT) mutated (pATM), phosphorylated p53 (pp53) and p21. Finally, TRF2 silencing markedly upregulated DDR, apoptosis and proinflammatory cytokines production in HC naïve CD4+ T cells. CONCLUSION: Our study demonstrated that TRF2 deficiency in BD naïve CD4+ T cells promoted cell apoptosis and senescence, leading to proinflammatory cytokines overproduction. Therefore, restoring TRF2 might be a promising therapeutic strategy for BD.

Platycodin D2 enhances P21/CyclinA2-mediated senescence of HCC cells by regulating NIX-induced mitophagy.

BACKGROUND: Hepatocellular carcinoma (HCC) cells usually show strong resistance to chemotherapy, which not only reduces the efficacy of chemotherapy but also increases the side effects. Regulation of autophagy plays an important role in tumor treatment. Cell senescence is also an important anti-cancer mechanism, which has become an important target for tumor treatment. Therefore, it is of great clinical significance to find anti-HCC drugs that act through this new mechanism. Platycodin D2 (PD2) is a new saponin compound extracted from the traditional Chinese medicine Platycodon grandiflorum. PURPOSE: Our study aimed to explore the effects of PD2 on HCC and identify the underlying mechanisms. METHODS: First, the CCK8 assay was used to detect the inhibitory effect of PD2 on HCC cells. Then, different pathways of programmed cell death and cell cycle regulators were measured. In addition, we assessed the effects of PD2 on the autophagy and senescence of HCC cells by flow cytometry, immunofluorescence staining, and Western blotting. Finally, we studied the in vivo effect of PD2 on HCC cells by using a mouse tumor-bearing model. RESULTS: Studies have shown that PD2 has a good anti-tumor effect, but the specific molecular mechanism has not been clarified. In this study, we found that PD2 has no obvious toxic effect on normal hepatocytes, but it can significantly inhibit the proliferation of HCC cells, induce mitochondrial dysfunction, enhance autophagy and cell senescence, upregulate NIX and P21, and downregulate CyclinA2. Gene silencing and overexpression indicated that PD2 induced mitophagy in HCC cells through NIX, thereby activating the P21/CyclinA2 pathway and promoting cell senescence. CONCLUSIONS: These results indicate that PD2 induces HCC cell death through autophagy and aging. Our findings provide a new strategy for treating HCC.

NR2F2 alleviates pulmonary fibrosis by inhibition of epithelial cell senescence.

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive, fatal, and aging-associated interstitial lung disease with a poor prognosis and limited treatment options, while the pathogenesis remains elusive. In this study, we found that the expression of nuclear receptor subfamily 2 group F member 2 (NR2F2), a member of the steroid thyroid hormone superfamily of nuclear receptors, was reduced in both IPF and bleomycin-induced fibrotic lungs, markedly in bleomycin-induced senescent epithelial cells. Inhibition of NR2F2 expression increased the expression of senescence markers such as p21 and p16 in lung epithelial cells, and activated fibroblasts through epithelial-mesenchymal crosstalk, inversely overexpression of NR2F2 alleviated bleomycin-induced epithelial cell senescence and inhibited fibroblast activation. Subsequent mechanistic studies revealed that overexpression of NR2F2 alleviated DNA damage in lung epithelial cells and inhibited cell senescence. Adenovirus-mediated Nr2f2 overexpression attenuated bleomycin-induced lung fibrosis and cell senescence in mice. In summary, these data demonstrate that NR2F2 is involved in lung epithelial cell senescence, and targeting NR2F2 may be a promising therapeutic approach against lung cell senescence and fibrosis.

Human platelet lysate enhances in vivo activity of CAR-Vδ2 T cells by reducing cellular senescence and apoptosis.

BACKGROUND AIMS: Vγ9Vδ2 T cells are an attractive cell platform for the off-the-shelf cancer immunotherapy as the result of their lack of alloreactivity and inherent multi-pronged cytotoxicity, which could be further amplified with chimeric antigen receptors (CARs). In this study, we sought to enhance the in vivo longevity of CAR-Vδ2 T cells by modulating ex vivo manufacturing conditions and selecting an optimal CAR costimulatory domain. METHODS: Specifically, we compared the anti-tumor activity of Vδ2 T cells expressing anti-CD19 CARs with costimulatory endodomains derived from CD28, 4-1BB or CD27 and generated in either standard fetal bovine serum (FBS)- or human platelet lysate (HPL)-supplemented medium. RESULTS: We found that HPL supported greater expansion of CAR-Vδ2 T cells with comparable in vitro cytotoxicity and cytokine secretion to FBS-expanded CAR-Vδ2 T cells. HPL-expanded CAR-Vδ2 T cells showed enhanced in vivo anti-tumor activity with longer T-cell persistence compared with FBS counterparts, with 4-1BB costimulated CAR showing the greatest activity. Mechanistically, HPL-expanded CAR Vδ2 T cells exhibited reduced apoptosis and senescence transcriptional pathways compared to FBS-expanded CAR-Vδ2 T cells and increased telomerase activity. CONCLUSIONS: This study supports enhancement of therapeutic potency of CAR-Vδ2 T cells through a manufacturing improvement.

Hyperoside alleviates photoreceptor degeneration by preventing cell senescence through AMPK-ULK1 signaling.

Vision loss and blindness are frequently caused by photoreceptor degeneration, for example in age-related macular degeneration and retinitis pigmentosa. However, there is no effective medicine to treat these photoreceptor degeneration-related diseases. Cell senescence is a common phenotype in many diseases; however, few studies have reported whether it occurs in photoreceptor degeneration diseases. Herein, we identified that cell senescence is associated with photoreceptor degeneration induced by N-methyl-N-nitrosourea (MNU, a commonly used photoreceptor degeneration model), presented as increased senescence-associated ß-galactosidase activity, DNA damage, oxidative stress and inflammation-related cytokine Interleukin 6 (IL6), and upregulation of cyclin p21 or p16. These results suggested that visual function might be protected using anti-aging treatment. Furthermore, Hyperoside is reported to help prevent aging in various organs. In this study, we showed that Hyperoside, delivered intravitreally, alleviated photoreceptor cell senescence and ameliorated the functional and morphological degeneration of the retina in vivo and in vitro. Importantly, Hyperoside attenuated the MNU-induced injury and aging of photoreceptors via AMPK-ULK1 signaling inhibition. Taken together, our results demonstrated that Hyperoside can prevent MNU-induced photoreceptor degeneration by inhibiting cell senescence via the AMPK-ULK1 pathway.

Impact of 10-day bed rest on serum levels of irisin and markers of musculoskeletal metabolism.

The bed rest (BR) is a ground-based model to simulate microgravity mimicking skeletal-muscle alterations as in spaceflight. Molecular coupling between bone and muscle might be involved in physiological and pathological conditions. Thus, the new myokine irisin and bone-muscle turnover markers have been studied during and after 10 days of BR. Ten young male individuals were subjected to 10 days of horizontal BR. Serum concentrations of irisin, myostatin, sclerostin, and haptoglobin were assessed, and muscle tissue gene expression on vastus lateralis biopsies was determined. During 10-days BR, we observed no significant fluctuation levels of irisin, myostatin, and sclerostin. Two days after BR (R+2), irisin serum levels significantly decreased while myostatin, sclerostin, and haptoglobin were significantly increased compared with BR0. Gene expression of myokines, inflammatory molecules, transcription factors, and markers of muscle atrophy and senescence on muscle biopsies were not altered, suggesting that muscle metabolism of young, healthy subjects is able to adapt to the hypomobility condition during 10-day BR. However, when subjects were divided according to irisin serum levels at BR9, muscle ring finger-1 mRNA expression was significantly lower in subjects with higher irisin serum levels, suggesting that this myokine may prevent the triggering of muscle atrophy. Moreover, the negative correlation between p21 mRNA and irisin at BR9 indicated a possible inhibitory effect of the myokine on the senescence marker. In conclusion, irisin could be a prognostic marker of hypomobility-induced muscle atrophy, and its serum levels could protect against muscle deterioration by preventing and/or delaying the expression of atrophy and senescence cellular markers.

Macrophage-derived exosomes promote telomere fragility and senescence in tubular epithelial cells by delivering miR-155.

BACKGROUND: Chronic kidney disease (CKD) is highly prevalent worldwide, and its global burden is substantial and growing. CKD displays a number of features of accelerated senescence. Tubular cell senescence is a common biological process that contributes to CKD progression. Tubulointerstitial inflammation is a driver of tubular cell senescence and a common characteristic of CKD. However, the mechanism by which the interstitial inflammation drives tubular cell senescence remains unclear. This paper aims to explore the role of exosomal miRNAs derived from macrophages in the development of tubular cell senescence. METHODS: Among the identified inflammation-related miRNAs, miR-155 is considered to be one of the most important miRNAs involved in the inflammatory response. Macrophages, the primary immune cells that mediate inflammatory processes, contain a high abundance of miR-155 in their released exosomes. We assessed the potential role of miR-155 in tubular cell senescence and renal fibrosis. We subjected miR-155-/- mice and wild-type controls, as well as tubular epithelial cells (TECs), to angiotensin II (AngII)-induced kidney injury. We assessed kidney function and injury using standard techniques. TECs were evaluated for cell senescence and telomere dysfunction in vivo and in vitro. Telomeres were measured by the fluorescence in situ hybridization. RESULTS: Compared with normal controls, miR-155 was up-regulated in proximal renal tubule cells in CKD patients and mouse models of CKD. Moreover, the expression of miR-155 was positively correlated with the extent of renal fibrosis, eGFR decline and p16INK4A expression. The overexpression of miR-155 exacerbated tubular senescence, evidenced by increased detection of p16INK4A/p21expression and senescence-associated ß-galactosidase activity. Notably, miR-155 knockout attenuates renal fibrosis and tubule cell senescence in vivo. Interestingly, once released, macrophages-derived exosomal miR-155 was internalized by TECs, leading to telomere shortening and dysfunction through targeting TRF1. A dual-luciferase reporter assay confirmed that TRF1 was the direct target of miR-155. Thus, our study clearly demonstrates that exosomal miR-155 may mediate communication between macrophages and TECs, subsequently inducing telomere dysfunction and senescence in TECs. CONCLUSIONS: Our work suggests a new mechanism by which macrophage exosomes are involved in the development of tubule senescence and renal fibrosis, in part by delivering miR-155 to target TRF1 to promote telomere dysfunction. Our study may provide novel strategies for the treatment of AngII-induced kidney injury.