Senescence-Associated MicroRNAs

miR-548az-5p induces amniotic epithelial cell senescence by regulating KATNAL1 expression in labor

Amniotic fluid exosomes (AF-Exos) from term labor (TL) cause amniotic membrane senescence and induce labor. However, the intrinsic mechanism through which this occurs remains unknown. Therefore, we performed microRNA (miRNA) microarray chip screening of AF-Exos obtained from TL and terms not in labor and discovered that the expression of miR-548az-5p was significantly upregulated in TL. This study aimed to explore the role of miR-548az-5p in AF-Exos-induced human amniotic epithelial cells (hAECs) senescence for labor initiation. Bioinformatics analysis revealed that Katanin catalytic subunit A1 like 1 (KATNAL1) is a potential miR-548az-5p target. In hAECs, the upregulation of miR-548az-5p suppressed KATNAL1 expression, disorganized microtubules, increased senescence-associated secretory phenotype-related biomarkers, and inhibited cell proliferation by cyclin D1 and cyclin-dependent kinase 6 (CDK6). This study identified that miR-548az-5p is involved in the senescence of amniotic epithelial cells by targeting KATNAL1 to induce labor. Notably, this study offers new perspectives on the mediation of cellular senescence using AF-Exos miRNAs, which results in labor.

Emerging insights in senescence: pathways from preclinical models to therapeutic innovations

Senescence is a crucial hallmark of ageing and a significant contributor to the pathology of age-related disorders. As committee members of the young International Cell Senescence Association (yICSA), we aim to synthesise recent advancements in the identification, characterisation, and therapeutic targeting of senescence for clinical translation. We explore novel molecular techniques that have enhanced our understanding of senescent cell heterogeneity and their roles in tissue regeneration and pathology. Additionally, we delve into in vivo models of senescence, both non-mammalian and mammalian, to highlight tools available for advancing the contextual understanding of in vivo senescence. Furthermore, we discuss innovative diagnostic tools and senotherapeutic approaches, emphasising their potential for clinical application. Future directions of senescence research are explored, underscoring the need for precise, context-specific senescence classification and the integration of advanced technologies such as machine learning, long-read sequencing, and multifunctional senoprobes and senolytics. The dual role of senescence in promoting tissue homoeostasis and contributing to chronic diseases highlights the complexity of targeting these cells for improved clinical outcomes.

Painting the plant body: pigment biosynthetic pathways regulated by small RNAs

Plant pigments are diverse natural molecules involved in numerous biological functions such as development, growth, and metabolism. As plants age, not only new organs will be formed, but also, they will acquire the necessary pigments in response to the environment and endogenous programming in order to achieve reproductive success. Among the endogenous cues, the small RNAs (sRNAs), an endogenous group of ubiquitous regulatory molecules, may regulate the pigments-associated biosynthetic pathways at posttranscriptional level. Although plant pigments and sRNAs have been comprehensively studied in several processes throughout the entire plant cycle in model and nonmodel species, connections among these central players must be revised. Studying these complex networks allow us not only to know the progress that has been made in this area, but also generate research questions to be explored in order to unravel novel mechanisms for improving plant yield; therefore, in this review we have summarized the emerging roles of sRNAs-regulated nodes in mediating plant pigmentation-associated biosynthetic pathways, focused on chlorophylls, flavonoids, carotenoids, and betalains. In addition, we discuss perspectives related to the manipulation of those genes associated with plant pigments for obtaining genetically improved plants.

A smartphone-assisted electrochemiluminescent biosensor for highly sensitive detection of miRNA-21 based on Ru(bpy)2(L)4+@MOF-5

A smartphone-assisted electrochemiluminescence (ECL) strategy based on Ru(bpy)2(L)4+ as chromophores confined with metal - organic frameworks (Ru(bpy)2(L)4+@MOF-5) for the signal-amplified detection of miRNA-21 was developed. We synthesized a derivative of tris(2,2'-bipyridyl)ruthenium(II) complex (Ru(bpy)2(L)4+) with high charges, which can be loaded into the MOF-5 by strong electrostatic interaction to prevent from leakage. In addition, nucleic acid cycle amplification was used to quench the signal of Ru(bpy)2(L)4+@MOF-5 by ferrocene. This method was applied to detect the concentration of miRNA-21 ranging from 1.0 × 10-14-1.0 × 10-9 M with a low LOD of 7.2 fM. This work demonstrated the construction of a signal quenching strategy ECL biosensor for miRNA using Ru(bpy)2(L)4+@MOF-5 systems and its application in smartphone-assisted ECL detection.

Targeting Cell Senescence and Senolytics: Novel Interventions for Age-Related Endocrine Dysfunction

Multiple changes occur in hormonal regulation with aging and across various endocrine organs. These changes are associated with multiple age-related disorders and diseases. A better understanding of responsible underling biological mechanisms could help in the management of multiple endocrine disorders over and above hormone replacement therapy (HRT). Cellular senescence is involved in multiple biological aging processes and pathologies common in elderly individuals. Cellular senescence, which occurs in many older individuals but also across the lifespan in association with tissue damage, acute and chronic diseases, certain drugs, and genetic syndromes, may contribute to such endocrine disorders as osteoporosis, metabolic syndrome, and type 2 diabetes mellitus. Drugs that selectively induce senescent cell removal, "senolytics,", and drugs that attenuate the tissue-destructive secretory state of certain senescent cells, "senomorphics," appear to delay the onset of or alleviate multiple diseases, including but not limited to endocrine disorders such as diabetes, complications of obesity, age-related osteoporosis, and cancers as well as atherosclerosis, chronic kidney disease, neurodegenerative disorders, and many others. More than 30 clinical trials of senolytic and senomorphic agents have already been completed, are underway, or are planned for a variety of indications. Targeting senescent cells is a novel strategy that is distinct from conventional therapies such as HRT, and thus might address unmet medical needs and can potentially amplify effects of established endocrine drug regimens, perhaps allowing for dose decreases and reducing side effects.

CircRNAs in cancer therapy tolerance

The rapidly expanding field of circular RNA (circ-RNA) research has opened new avenues in cancer diagnostics and treatment, highlighting the role of serum circRNAs as potential biomarkers for assessing tumor therapy resistance. This review comprehensively compiles existing knowledge regarding the biogenesis, function, and clinical relevance of circRNAs, emphasizing their stability, abundance, and cell type-specific expression profiles, which make them ideal candidates for noninvasive early biomarkers in cancer treatment. We explored the roles of circRNAs in oncogenesis and tumor progression and their complex interactions with patient responses to various cancer treatments, such as chemotherapy, radiotherapy, targeted therapy, and immunotherapy. Through the analysis of data from recent studies and clinical trials, we underscore the prognostic significance of serum circRNAs in predicting therapeutic outcomes, their involvement in resistance mechanisms, and their capacity to inform personalized treatment approaches. Additionally, this review addresses the obstacles inherent in circRNA research, including the need for standardized protocols for circRNA extraction and quantification and the elucidation of the clinical significance of circRNAs. Furthermore, our investigation extends to future prospects, including embedding circRNA profiling into regular clinical workflows and pioneering circRNA-based therapeutic approaches. We underscore the transformative potential of serum circRNAs in enhancing cancer diagnosis, improving the accuracy of therapy tolerance predictions, and ultimately fostering the advent of precision oncology.

Emerging Roles of Vitamin B12 in Aging and Inflammation

Vitamin B12 (cobalamin) is an essential nutrient for humans and animals. Metabolically active forms of B12-methylcobalamin and 5-deoxyadenosylcobalamin are cofactors for the enzymes methionine synthase and mitochondrial methylmalonyl-CoA mutase. Malfunction of these enzymes due to a scarcity of vitamin B12 leads to disturbance of one-carbon metabolism and impaired mitochondrial function. A significant fraction of the population (up to 20%) is deficient in vitamin B12, with a higher rate of deficiency among elderly people. B12 deficiency is associated with numerous hallmarks of aging at the cellular and organismal levels. Cellular senescence is characterized by high levels of DNA damage by metabolic abnormalities, increased mitochondrial dysfunction, and disturbance of epigenetic regulation. B12 deficiency could be responsible for or play a crucial part in these disorders. In this review, we focus on a comprehensive analysis of molecular mechanisms through which vitamin B12 influences aging. We review new data about how deficiency in vitamin B12 may accelerate cellular aging. Despite indications that vitamin B12 has an important role in health and healthy aging, knowledge of the influence of vitamin B12 on aging is still limited and requires further research.

The Molecular Mechanisms in Senescent Cells Induced by Natural Aging and Ionizing Radiation

This review discusses the relationship between cellular senescence and radiation exposure. Given the wide range of ionizing radiation sources encountered by people in professional and medical spheres, as well as the influence of natural background radiation, the question of the effect of radiation on biological processes, particularly on aging processes, remains highly relevant. The parallel relationship between natural and radiation-induced cellular senescence reveals the common aspects underlying these processes. Based on recent scientific data, the key points of the effects of ionizing radiation on cellular processes associated with aging, such as genome instability, mitochondrial dysfunction, altered expression of miRNAs, epigenetic profile, and manifestation of the senescence-associated secretory phenotype (SASP), are discussed. Unraveling the molecular mechanisms of cellular senescence can make a valuable contribution to the understanding of the molecular genetic basis of age-associated diseases in the context of environmental exposure.

AMPK-upregulated microRNA-708 plays as a suppressor of cellular senescence and aging via downregulating disabled-2 and mTORC1 activation

Senescence-associated microRNAs (SA-miRNAs) are important molecules for aging regulation. While many aging-promoting SA-miRNAs have been identified, confirmed aging-suppressive SA-miRNAs are rare, that impeded our full understanding on aging regulation. In this study, we verified that miR-708 expression is decreased in senescent cells and aged tissues and revealed that miR-708 overexpression can alleviate cellular senescence and aging performance. About the molecular cascade carrying the aging suppressive action of miR-708, we unraveled that miR-708 directly targets the 3'UTR of the disabled 2 (Dab2) gene and inhibits the expression of DAB2. Interestingly, miR-708-caused DAB2 downregulation blocks the aberrant mammalian target of rapamycin complex 1 (mTORC1) activation, a driving metabolic event for senescence progression, and restores the impaired autophagy, a downstream event of aberrant mTORC1 activation. We also found that AMP-activated protein kinase (AMPK) activation can upregulate miR-708 via the elevation of DICER expression, and miR-708 inhibitor is able to blunt the antiaging effect of AMPK. In summary, this study characterized miR-708 as an aging-suppressive SA-miRNA for the first time and uncovered a new signaling cascade, in which miR-708 links the DAB2/mTOR axis and AMPK/DICER axis together. These findings not only demonstrate the potential role of miR-708 in aging regulation, but also expand the signaling network connecting AMPK and mTORC1.

Potential Clinical Implications of Senotherapies for Cardiovascular Disease

Aging is a major risk factor for cardiovascular diseases (CVDs) and accumulating evidence indicates that biological aging has a significant effect on the onset and progression of CVDs. In recent years, therapies targeting senescent cells (senotherapies), particularly senolytics that selectively eliminate senescent cells, have been developed and show promise for treating geriatric syndromes and age-associated diseases, including CVDs. In 2 pilot studies published in 2019 the senolytic combination, dasatinib plus quercetin, improved physical function in patients with idiopathic pulmonary fibrosis and eliminated senescent cells from adipose tissue in patients with diabetic kidney disease. More than 30 clinical trials using senolytics are currently underway or planned. In preclinical CVD models, senolytics appear to improve heart failure, ischemic heart disease, valvular heart disease, atherosclerosis, aortic aneurysm, vascular dysfunction, dialysis arteriovenous fistula patency, and pre-eclampsia. Because senotherapies are completely different strategies from existing treatment paradigms, they might alleviate diseases for which there are no current effective treatments or they could be used in addition to current therapies to enhance efficacy. Moreover, senotherapies might delay, prevent, alleviate or treat multiple diseases in the elderly and reduce polypharmacy, because senotherapies target fundamental aging mechanisms. We comprehensively summarize the preclinical evidence about senotherapies for CVDs and discuss future prospects for their clinical application.

A novel upregulated hsa_circ_0032746 regulates the oncogenesis of esophageal squamous cell carcinoma by regulating miR-4270/MCM3 axis

INTRODUCTION

Circular RNAs (CircRNA) have emerged as an interest of research in recent years due to its regulatory role in various kinds of cancers of human body. Esophageal squamous cell carcinoma (ESCC) is one of the major disease subtype in Asian countries, including China. CircRNAs are formed by back-splicing covalently joined 3'- and 5'- ends rather than canonical splicing and are found to have binding affinity with miRNAs that conjointly contribute to oncogenesis.

MATERIALS AND METHODS

4 pairs of normal, cancer adjacent tissues and cancer tissues were analyzed by high-throughput RNA sequencing and 84 differentially upregulated circRNAs were detected in cancer tissues. hsa_circ_0032746 was silenced by siRNA and lentivirus and then further proliferation, migration and invasion were performed by CCK-8 and transwell assays. Bioinformatic analysis  predicted binding affinity of circRNA/miRNA/mRNA axis.

RESULTS

After qPCR validation, we selected a novel upregulated hsa_circ_0032746 to explore its biogenetic functions which showed high expression in cancer tissues but not in cancer adjacent tissues. The clinicopathological relation of hsa_circ_0032746 showed positive correlation with the tumor location (P = 0.026) and gender (P = 0.05). We also predicted that hsa_circ_0032746 could sponge with microRNA. Bioinformatic analysis predicted 11 microRNA response element (MRE) sequences of hsa_circ_0032746 and dual luciferase reporter assay confirmed binding affinity with miR4270 evidencing further study of circRNA/miRNA role. The knockdown of hsa_circ_0032746 by siRNA and lentivirus demonstrated that proliferation, invasion and migration of ESCC were inhibited in vitro and vivo experiments. Bioinformatic analysis further predicted MCM3 as a target of miR-4270 and was found upregulated in ESCC upon validation. miR4270 mimic decreased the level of hsa_circ_0032746 and MCM3 while further rescue experiments demonstrated that hsa_circ_0032746 was dependent on miR4270/MCM3 axis on the development process of ESCC.

CONCLUSION

We revealed for the first time that circ_0032746/mir4270/MCM3 contributes in proliferation, migration and invasion of ESCC and could have potential prognostic and therapeutic significance.

The role of non-coding RNAs in muscle aging: regulatory mechanisms and therapeutic potential

Muscle aging is a complex physiological process that leads to the progressive decline in muscle mass and function, contributing to debilitating conditions in the elderly such as sarcopenia. In recent years, non-coding RNAs (ncRNAs) have been increasingly recognized as major regulators of muscle aging and related cellular processes. Here, we comprehensively review the emerging role of ncRNAs, including microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs), in the regulation of muscle aging. We also discuss how targeting these ncRNAs can be explored for the development of novel interventions to combat age-related muscle decline. The insights provided in this review offer a promising avenue for future research and therapeutic strategies aimed at improving muscle health during aging.

Effect of miR-21 in mesenchymal stem cells-derived extracellular vesicles behavior

BACKGROUND

A challenging new branch of research related to aging-associated diseases is the identification of miRNAs capable of modulating the senescence-associated secretory phenotype (SASP) which characterizes senescent cells and contributes to driving inflammation.

METHODS

Mesenchymal stem cells (MSC) from human umbilical cord stroma were stable modified using lentivirus transduction to inhibit miR-21-5p and shotgun proteomic analysis was performed in the MSC-derived extracellular vesicles (EV) to check the effect of miR-21 inhibition in their protein cargo. Besides, we studied the paracrine effect of those modified extracellular vesicles and also their effect on SASP.

RESULTS

Syndecan-1 (SDC1) was the most decreased protein in MSC-miR21--derived EV, and it was involved in inflammation and EV production. MSC-miR21--derived EV were found to produce a statistically significant inhibitory effect on SASP and inflammaging markers expression in receptor cells, and in the opposite way, these receptor cells increased their SASP and inflammaging expression statistically significantly when treated with MSC-miR-21+-derived EV.

CONCLUSION

This work demonstrates the importance of miR-21 in inflammaging and its role in SASP through SDC1.

P53‑microRNA interactions regulate the response of colorectal tumor cells to oxaliplatin under normoxic and hypoxic conditions

Oxaliplatin (OXA)‑containing regimens are used as first‑line chemotherapy in colorectal cancer (CRC). However, OXA resistance remains a major challenge in CRC treatment. CRC cells that adapt to hypoxia can potentially develop OXA resistance, and the underlying molecular mechanisms still need to be further investigated. In the current study, the OXA drug sensitivity of two CRC cell lines, HCT116 (TP53WT) and HT29 (TP53MT), was compared under both normoxic and hypoxic conditions. It was found that under normoxic condition, HCT116 cells showed significantly higher OXA sensitivity than HT29 cells. However, both cell lines showed remarkable OXA resistance under hypoxic conditions. It was also revealed that P53 levels were increased after OXA and hypoxia treatment in HCT116 cells but not in HT29 cells. Notably, knocking down P53WT decreased normoxic but increased hypoxic OXA sensitivity in HCT116 cells, which did not exist in HT29 cells. Molecular analysis indicated that P53WT activated microRNA (miR)‑26a and miR‑34a in OXA treatment and activated miR‑23a in hypoxia treatment. Cell proliferation experiments indicated that a high level of miR‑23a decreased OXA sensitivity and that a high level of miR‑26a or miR‑34a increased OXA sensitivity in HCT116 cells. Additionally, it was demonstrated that miR‑26a, miR‑34a and miR‑23a affect cell apoptosis through regulation of MCL‑1, EZH2, BCL‑2, SMAD 4 and STAT3. Taken together, the present findings revealed the dual function of P53 in regulating cellular chemo‑sensitivity and highlighted the role of P53‑miR interactions in the response of CRC cells to OXA chemotherapy under normoxic and hypoxic conditions.

The ideal treatment timing for diabetic retinopathy: the molecular pathological mechanisms underlying early-stage diabetic retinopathy are a matter of concern

Diabetic retinopathy (DR) is a prevalent complication of diabetes, significantly impacting patients' quality of life due to vision loss. No pharmacological therapies are currently approved for DR, excepted the drugs to treat diabetic macular edema such as the anti-VEGF agents or steroids administered by intraocular route. Advancements in research have highlighted the crucial role of early intervention in DR for halting or delaying disease progression. This holds immense significance in enhancing patients' quality of life and alleviating the societal burden associated with medical care costs. The non-proliferative stage represents the early phase of DR. In comparison to the proliferative stage, pathological changes primarily manifest as microangiomas and hemorrhages, while at the cellular level, there is a loss of pericytes, neuronal cell death, and disruption of components and functionality within the retinal neuronal vascular unit encompassing pericytes and neurons. Both neurodegenerative and microvascular abnormalities manifest in the early stages of DR. Therefore, our focus lies on the non-proliferative stage of DR and we have initially summarized the mechanisms involved in its development, including pathways such as polyols, that revolve around the pathological changes occurring during this early stage. We also integrate cutting-edge mechanisms, including leukocyte adhesion, neutrophil extracellular traps, multiple RNA regulation, microorganisms, cell death (ferroptosis and pyroptosis), and other related mechanisms. The current status of drug therapy for early-stage DR is also discussed to provide insights for the development of pharmaceutical interventions targeting the early treatment of DR.

Pro-inflammatory cytokines mediating senescence of vascular endothelial cells in atherosclerosis

Atherosclerosis (AS) is a chronic inflammatory vascular disease, and aging is a major risk factor. The accumulation of senescent vascular endothelial cells (VECs) often leads to chronic inflammation and oxidative stress and induces endothelial dysfunction, contributing to the occurrence and development of AS. Senescent cells can secrete a variety of pro-inflammatory cytokines to induce the senescence of adjacent cells in a paracrine manner, leading to the transmission of signaling of cellular senescence to neighboring cells and the accumulation of senescent cells. Recent studies have demonstrated that several pro-inflammatory cytokines, including IL-17, TNF-α, and IFN-γ, can induce the senescence of VECs. This review summarizes and focuses on the pro-inflammatory cytokines that often induce the senescence of VECs and the molecular mechanisms of these pro-inflammatory cytokines inducing senescence of VECs. Targeting the senescence of VECs induced by pro-inflammatory cytokines may provide a potential and novel strategy for the prevention and treatment of AS.

Research progress on the pathogenesis of diabetic retinopathy

Diabetic retinopathy is one of the most common and serious microvascular complications of diabetes mellitus. There are many factors leading to diabetic retinopathy, and its pathogenesis is still unclear. At present, there are still no effective measures for the early treatment of diabetic retinopathy, and the treatment options available when diabetes progresses to advanced stages are very limited, and the treatment results are often unsatisfactory. Detailed studies on the molecular mechanisms of diabetic retinopathy pathogenesis and the development of new therapeutic agents are of great importance. This review describes the potential pathogenesis of diabetic retinopathy for experimental studies and clinical practice.

Novel Molecular Subtyping Scheme Based on In Silico Analysis of Cuproptosis Regulator Gene Patterns Optimizes Survival Prediction and Treatment of Hepatocellular Carcinoma

BACKGROUND

The liver plays an important role in maintaining copper homeostasis. Copper ion accumulation was elevated in HCC tissue samples. Copper homeostasis is implicated in cancer cell proliferation and angiogenesis. The potential of copper homeostasis as a new theranostic biomarker for molecular imaging and the targeted therapy of HCC has been demonstrated. Recent studies have reported a novel copper-dependent nonapoptotic form of cell death called cuproptosis, strikingly different from other known forms of cell death. The correlation between cuproptosis and hepatocellular carcinoma (HCC) is not fully understood.

MATERIALS AND METHODS

The transcriptomic data of patients with HCC were retrieved from the Cancer Genome Atlas-Liver Hepatocellular Carcinoma (TCGA-LIHC) and were used as a discovery cohort to construct the prognosis model. The gene expression data of patients with HCC retrieved from the International Cancer Genome Consortium (ICGC) and Gene Expression Omnibus (GEO) databases were used as the validation cohort. The Least Absolute Shrinkage and Selection Operator (LASSO) regression analysis was used to construct the prognosis model. A principal component analysis (PCA) was used to evaluate the overall characteristics of cuproptosis regulator genes and obtain the PC1 and PC2 scores. Unsupervised clustering was performed using the ConsensusClusterPlus R package to identify the molecular subtypes of HCC. Cox regression analysis was performed to identify cuproptosis regulator genes that could predict the prognosis of patients with HCC. The receiver operating characteristics curve and Kaplan-Meier survival analysis were used to understand the role of hub genes in predicting the diagnosis and prognosis of patients, as well as the prognosis risk model. A weighted gene co-expression network analysis (WGCNA) was used for screening the cuproptosis subtype-related hub genes. The functional enrichment analysis was performed using Metascape. The 'glmnet' R package was used to perform the LASSO regression analysis, and the randomForest algorithm was performed using the 'randomForest' R package. The 'pRRophetic' R package was used to estimate the anticancer drug sensitivity based on the data retrieved from the Genomics of Drug Sensitivity in Cancer database. The nomogram was constructed using the 'rms' R package. Pearson's correlation analysis was used to analyze the correlations.

RESULTS

We constructed a six-gene signature prognosis model and a nomogram to predict the prognosis of patients with HCC. The Kaplan-Meier survival analysis revealed that patients with a high-risk score, which was predicted by the six-gene signature model, had poor prognoses (log-rank test p < 0.001; HR = 1.83). The patients with HCC were grouped into three distinct cuproptosis subtypes (Cu-clusters A, B, and C) based on the expression pattern of cuproptosis regulator genes. The patients in Cu-cluster B had poor prognosis (log-rank test p < 0.001), high genomic instability, and were not sensitive to conventional chemotherapeutic treatment compared to the patients in the other subtypes. Cancer cells in Cu-cluster B exhibited a higher degree of the senescence-associated secretory phenotype (SASP), a marker of cellular senescence. Three representative genes, CDCA8, MCM6, and NCAPG2, were identified in patients in Cu-cluster B using WGCNA and the "randomForest" algorithm. A nomogram was constructed to screen patients in the Cu-cluster B subtype based on three genes: CDCA8, MCM6, and NCAPG2.

CONCLUSION

Publicly available databases and various bioinformatics tools were used to study the heterogeneity of cuproptosis in patients with HCC. Three HCC subtypes were identified, with differences in the survival outcomes, genomic instability, senescence environment, and response to anticancer drugs. Further, three cuproptosis-related genes were identified, which could be used to design personalized therapeutic strategies for HCC.

Identification and Validation of an Aging-Associated circRNA-miRNA-mRNA Network in Neovascular Age-Related Macular Degeneration

INTRODUCTION

Neovascular age-related macular degeneration (NVAMD) is a leading cause of severe vision impairment in the elderly. Aging is one of the most pivotal underlying molecular mechanisms of NVAMD.

METHODS

In this study, we identified the potential aging-related genes involved in NVAMD. Considering that noncoding RNAs are vital regulators of NVAMD progression, we further explored and constructed an aging-originated circRNA-miRNA-mRNA network of NVAMD. Differential expression of 23 aging-associated genes was identified based on sequencing data and the Human Aging Genomic Resources tool at a threshold of p < 0.05, and log2|fold change| > 1.

RESULTS

We screened 12 microRNAs (miRNAs) using public datasets and miRNet database. A total of 13 circRNAs were subsequently mined using the starBase tool. Merging these 13 circRNAs, 12 miRNAs, and 15 genes together, we obtained 281 pairs of circRNA-miRNA and 30 pairs of miRNA-mRNA.

CONCLUSION

We created an aging-related circRNA-miRNA-mRNA network, which could be a promising target for future AMD treatments.

Senescent Cells: A Therapeutic Target in Cardiovascular Diseases

Senescent cell accumulation has been observed in age-associated diseases including cardiovascular diseases. Senescent cells lack proliferative capacity and secrete senescence-associated secretory phenotype (SASP) factors that may cause or worsen many cardiovascular diseases. Therapies targeting senescent cells, especially senolytic drugs that selectively induce senescent cell removal, have been shown to delay, prevent, alleviate, or treat multiple age-associated diseases in preclinical models. Some senolytic clinical trials have already been completed or are underway for a number of diseases and geriatric syndromes. Understanding how cellular senescence affects the various cell types in the cardiovascular system, such as endothelial cells, vascular smooth muscle cells, fibroblasts, immune cells, progenitor cells, and cardiomyocytes, is important to facilitate translation of senotherapeutics into clinical interventions. This review highlights: (1) the characteristics of senescent cells and their involvement in cardiovascular diseases, focusing on the aforementioned cardiovascular cell types, (2) evidence about senolytic drugs and other senotherapeutics, and (3) the future path and clinical potential of senotherapeutics for cardiovascular diseases.

Senotherapy for lung diseases

Increasing evidence suggests that there is acceleration of lung ageing in chronic lung diseases, such as chronic obstructive pulmonary disease (COPD) and idiopathic pulmonary fibrosis (IPF), with the accumulation of senescent cells in the lung. Senescent cells fail to repair tissue damage and release an array of inflammatory proteins, known as the senescence-associated secretory phenotype, which drive further senescence and disease progression. This suggests that targeting cellular senescence with senotherapies may treat the underlying disease process in COPD and IPF and thus reduce disease progression and mortality. Several existing or future drugs may inhibit the development of cellular senescence which is driven by chronic oxidative stress (senostatics), including inhibitors of PI3K-mTOR signalling pathways, antagomirs of critical microRNAs and novel antioxidants. Other drugs (senolytics) selectively remove senescent cells by promoting apoptosis. Clinical studies with senotherapies are already underway in chronic lung diseases.

Cellular Senescence in Intervertebral Disc Aging and Degeneration: Molecular Mechanisms and Potential Therapeutic Opportunities

Closely associated with aging and age-related disorders, cellular senescence (CS) is the inability of cells to proliferate due to accumulated unrepaired cellular damage and irreversible cell cycle arrest. Senescent cells are characterized by their senescence-associated secretory phenotype that overproduces inflammatory and catabolic factors that hamper normal tissue homeostasis. Chronic accumulation of senescent cells is thought to be associated with intervertebral disc degeneration (IDD) in an aging population. This IDD is one of the largest age-dependent chronic disorders, often associated with neurological dysfunctions such as, low back pain, radiculopathy, and myelopathy. Senescent cells (SnCs) increase in number in the aged, degenerated discs, and have a causative role in driving age-related IDD. This review summarizes current evidence supporting the role of CS on onset and progression of age-related IDD. The discussion includes molecular pathways involved in CS such as p53-p21CIP1, p16INK4a, NF-κB, and MAPK, and the potential therapeutic value of targeting these pathways. We propose several mechanisms of CS in IDD including mechanical stress, oxidative stress, genotoxic stress, nutritional deprivation, and inflammatory stress. There are still large knowledge gaps in disc CS research, an understanding of which will provide opportunities to develop therapeutic interventions to treat age-related IDD.

Ablation of miRNA-22 protects against obesity-induced adipocyte senescence and ameliorates metabolic disorders in middle-aged mice

High-fat diet (HFD) promotes obesity-related metabolic complications by activating cellular senescence in white adipose tissue (WAT). Growing evidence supports the importance of microRNA-22 (miR-22) in metabolic disorders and cellular senescence. Recently, we showed that miR-22 deletion attenuates obesity-related metabolic abnormalities. However, whether miR-22 mediates HFD-induced cellular senescence of WAT remains unknown. Here, we uncovered that obese mice displayed increased pri-miR-22 levels and cellular senescence in WAT. However, miR-22 ablation protected mice against HFD-induced WAT senescence. In addition, in vitro studies showed that miR-22 deletion prevented preadipocyte senescence in response to Doxorubicin (Doxo). Loss-of-function studies in vitro and in vivo revealed that miR-22 increases H2ax mRNA and γH2ax levels in preadipocytes and WAT without inducing DNA damage. Intriguingly, miR-22 ablation prevented HFD-induced increase in γH2ax levels and DNA damage in WAT. Similarly, miR-22 deletion prevented Doxo-induced increase in γH2ax levels in preadipocytes. Adipose miR-22 levels were enhanced in middle-aged mice fed a HFD than those found in young mice. Furthermore, miR-22 deletion attenuated fat mass gain and glucose imbalance induced by HFD in middle-aged mice. Overall, our findings indicate that miR-22 is a key regulator of obesity-induced WAT senescence and metabolic disorders in middle-aged mice.

Radiation-induced pulmonary fibrosis: roles of therapy-induced senescence and microRNAs

PURPOSE

Progressive, irreversible radiation-induced pulmonary fibrosis (RIPF) is a clinically significant intermediate- to a late-occurring side effect of radiotherapy. Known mechanisms of RIPF include oxidative stress-induced activation of TGF-β with activation of SMAD signaling, TNF-α elaboration, and activation of the Angiotensin Converting Enzyme (ACE) mediated production of angiotensin II with resulting activation of profibrotic cytokine signaling and vasoconstriction. The pioneering work of John Moulder, to whom this paper is dedicated, and several of his colleagues demonstrated that inhibiting the conversion of ACE with drugs such as Captopril, Enalapril, and Losartan can ameliorate radiation fibrosis in various tissues. While this work led several groups to probe mechanism-based pharmacological mitigation of RIPF, in this article, we explore and discuss the roles of microRNAs (miRNA) and therapy-induced senescence (TIS) in the pathogenesis of and potential biomarkers for RIPF.

CONCLUSION

Our analysis of the published literature in the last decade on RIPF, miRNA, and TIS identifies TIS as a mechanism in the onset and progression of RIPF, which is regulated through several miRNAs. This work may lead to the discovery and development of the next generation of miRNA therapeutics and/or the repurposing of approved pharmaceutical agents and the development of early biomarker panels to predict RIPF.

SIRT1 as a Potential Therapeutic Target for Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is a common, preventable, and treatable disease characterized by irreversible airflow obstruction and lung function decline. It is well established that COPD represents a major cause of morbidity and mortality globally. Due to the substantial economic and social burdens associated with COPD, it is necessary to discover new targets and develop novel beneficial therapies. Although the pathogenesis of COPD is complex and remains to be robustly elucidated, numerous studies have shown that oxidative stress, inflammatory responses, cell apoptosis, autophagy, and aging are involved in the pathogenesis of COPD. Sirtuin 1 (SIRT1) is a nicotinamide adenine dinucleotide (NAD+)-dependent deacetylase belonging to the silent information regulator 2 (Sir2) family. Multiple studies have indicated that SIRT1 plays an important role in oxidative stress, apoptosis, inflammation, autophagy, and cellular senescence, which contributes to the pathogenesis and development of COPD. This review aimed to discuss the functions and mechanisms of SIRT1 in the progression of COPD and concluded that SIRT1 activation might be a potential therapeutic strategy for COPD.

Dynamic network biomarker identifies cdkn1a-mediated bone mineralization in the triggering phase of osteoporosis

The identification of predictive markers to determine the triggering phase prior to the onset of osteoporosis is essential to mitigate further irrevocable deterioration. To determine the early warning signs before osteoporosis, we used the dynamic network biomarker (DNB) approach to analyze time-series gene expression data in a zebrafish osteoporosis model, which revealed that cyclin-dependent kinase inhibitor 1 A (cdkn1a) is a core DNB. We found that cdkn1a negatively regulates osteogenesis, as evidenced by loss-of-function and gain-of-function studies. Specifically, CRISPR/Cas9-mediated cdkn1a knockout in zebrafish significantly altered skeletal development and increased bone mineralization, whereas inducible cdkn1a expression significantly contributed to osteoclast differentiation. We also found several mechanistic clues that cdkn1a participates in osteoclast differentiation by regulating its upstream signaling cascades. To summarize, in this study, we provided new insights into the dynamic nature of osteoporosis and identified cdkn1a as an early-warning signal of osteoporosis onset.

Mesenchymal stem cells ameliorate cisplatin-induced acute kidney injury via let-7b-5p

Acute kidney injury (AKI) is a clinically common kidney disease. Age is an important factor that contributes to the susceptibility to AKI. Mesenchymal stem cells (MSCs) are a promising therapy for AKI, and miRNAs in exosomes (Exos) derived from MSCs are an important aspect of MSC treatment. However, the therapeutic effect of miRNA from MSC-derived Exos on AKI and the related mechanism have not been fully clarified. Whether there is a relationship between the mechanisms of senescence for AKI susceptibility and the therapeutic effect of MSCs has not been studied. We compared the degree of cisplatin-induced AKI injury in young and elderly mice and investigated changes in the expression of p53 and markers of DNA damage and apoptosis, which are important in both senescence and AKI. Ageing mice exhibited increased expression of p53 and pro-apoptosis markers. Upregulation of the senescence-associated DNA damage/p53 pathway may be an important susceptibility factor for cisplatin-induced AKI. Treatment with MSCs can reduce the degree of DNA damage and suppress p53 expression and apoptosis. Upon screening for differentially expressed miRNAs, let-7b-5p levels were found to be lower in aged mice than in young mice, and MSC treatment increased let-7b-5p levels. The presence of let-7b-5p in MSC-derived Exos alleviates tubular epithelial cell apoptosis by inhibiting p53, which reduces DNA damage and apoptosis pathway activity. Let-7b-5p downregulation may lead to increased renal AKI susceptibility, thus indicating that this miRNA is a potential driver of the MSC treatment response in AKI.

Circ_0003611 regulates apoptosis and oxidative stress injury of Alzheimer's disease via miR-383-5p/KIF1B axis

Alzheimer's disease (AD) is a high incidence neurodegenerative disease. Emerging evidence suggests that circular RNAs (circRNAs) play an important modulator in the pathogenesis of AD. The aim of this paper was to reconnoiter the effects of circular RNA_0003611 (circ_0003611) on Aβ-triggered neuronal injury in AD. In this work, the abundance of circ_0003611 was augmented in AD patients and SH-SY5Y and SK-N-SH cells treated with Aβ. Aβ-mediated cell proliferation, apoptosis, inflammatory response, oxidative stress, and glycolysis were abolished through circ_0003611 silencing. Circ_0003611 worked as a miR-383-5p sponge, and the protective role of circ_0003611 absence on Aβ-triggered neuronal injury was overturned by releasing miR-383-5p. Meanwhile, miR-383-5p directly targeted KIF1B, and miR-383-5p upregulation might relieve Aβ-triggered neuronal injury by reducing KIF1B expression. Mechanical analysis discovered that circ_0003611 served as a sponge of miR-383-5p to impact KIF1B expression. These findings indicated that circ_0003611 improved Aβ-triggered neuronal injury in AD through targeting the miR-383-5p/KIF1B axis, which might deliver innovative therapy targeting for AD.

Resveratrol attenuates cigarette smoke extract induced cellular senescence in human airway epithelial cells by regulating the miR-34a/SIRT1/NF-κB pathway

Chronic obstructive pulmonary disease (COPD) is characterized by accelerated lung aging. Smoking is the critical risk factor for COPD. Cellular senescence of airway epithelial cells is the cytological basis of accelerated lung aging in COPD, and the regulation of microRNAs (miRNAs) is the central epigenetic mechanism of cellular senescence. Resveratrol (Res) is a polyphenol with anti-aging properties. This study investigated whether Res attenuates cigarette smoke extract (CSE)-induced cellular senescence in human airway epithelial cells (BEAS-2B) through the miR-34a/SIRT1/nuclear factor-kappaB (NF-κB) pathway. BEAS-2B cells were treated with Res, CSE and transfected with miR-34a-5p mimics. Cellular senescence was evaluated by senescence -related β-galactosidase (SA-β-gal) staining and expression of senescence-related genes (p16, p21, and p53). The expressions of miR-34a-5p, SIRT1, and NF-κB p65 were examined using quantitative real time polymerase chain reaction and western blotting. The senescence-associated secretory phenotype (SASP) cytokines (IL-1β, IL-6, IL-8, TNF-α) were assessed by enzyme-linked immunosorbent assay. The binding between miR-34a-5p and SIRT1 was confirmed by dual-luciferase reporter assay. The results showed that CSE dose-dependently decreased cell viability and elevated cellular senescence, characterized by increased SA-β-gal staining and senescence-related gene expressions (p16, p21, and p53). Further, CSE dose-dependently increased the expression of miR-34a-5p and SASP cytokines (IL-1β, IL-6, IL-8, TNF-α) in BEAS-2B cells. Pretreatment with Res inhibited CSE-induced cellular senescence and secretion of SASP cytokines (IL-1β, IL-6, IL-8, TNF-α) in a dose-dependent manner. Moreover, Res reversed the CSE-induced down-regulation of SIRT1 and up-regulation of miR-34a-5p and NF-κB p65. SIRT1 is a target of miR-34a-5p. Overexpression of miR-34a-5p via transfection with miR-34a-5p mimic in BEAS-2B cells attenuated the inhibitory effect of Res on cellular senescence, accompanied by reversing the expression of SIRT1 and NF-κB p65. In conclusion, Res attenuated CSE-induced cellular senescence in BEAS-2B cells by regulating the miR-34a/SIRT1/NF-κB pathway, which may provide a new approach for COPD treatment.

Potential therapeutic role of SIRT1 in age- related hearing loss

Age-related hearing loss (ARHL) is a major public health burden worldwide that profoundly affects the daily life of elderly people. Silent information regulator 1 (SIRT1 or Sirtuin1), known as a regulator of the cell cycle, the balance of oxidation/antioxidant and mitochondrial function, has been proven to have anti-aging and life-extending effects, and its possible connection with ARHL has received increasing attention in recent years. This paper provides an overview of research on the connection between SIRT1 and ARHL. Topics cover both the functions of SIRT1 and its important role in ARHL. This review concludes with a look at possible research directions for ARHL in the future.

In Vitro Study on the Biological Characteristics of Adipose-Derived Stem Cells from Liposuction Area in Patients with Progressive Hemifacial Atrophy

OBJECTIVE

In this study, we investigate the biological characteristics of ADSCs from the liposuction area in patients with hemifacial atrophy in vitro.

METHODS

ADSCs were respectively extracted from the donor site of patients with hemifacial atrophy and healthy ones. ADSCs of two groups were respectively tested for proliferation ability, phenotype, multipotency, migration ability, self-repair ability, apoptosis, and autophagy. Exosomes extracted from the supernatant of two groups were detected by NTA particle size, electron microscopy (TEM), and WB for CD63 and TSG10, respectively.

RESULTS

CCK-8 showed a statistically less increase in cell proliferation in PHA-ADSCs after the sixth day. ADSCs in both groups had typical phenotypes and multidirectional abilities. PHA-ADSCs exhibited weaker droplet formation. The cell migration ability in PHA-ADSCs was weaker tested by Transwell assay. The live/dead proportion calculated by ImageJ following calcein-AM/PI double staining revealed live cells in PHA-ADSCs was 46.11% compared with 54.21% in NORM-ADSCs after OGD treatment. A significant down-regulation of ATG7 and ATG12 and a higher percentage of apoptosis were found in PHA-ADSCs. A significant up-regulation of BAX occurred in PHA-ADSCs.ARPC5 expression in the PHA group was extremely distinct down-regulated.CDKN1A and CDKN2A expression in the PHA group was significantly up-regulated.WB analyses confirmed that both groups' ADSCs-Exosomes surface markers CD63 and TSG101 were positively expressed but varied significantly.

CONCLUSIONS

PHA-ADSCs exhibited a poorer proliferation ability, higher apoptosis percentage, weaker lipid droplets formation, weaker cell migration, poorer intolerance to OGD, aging earlier, and weaker self-renewal and repairability.PHA-ADSCs-Exosomes showed low expressions of CD63 and TSG101.This study provides strong evidence that the addition of exosomes with specific cytokines can improve the fat survival rate after fat filling in patients with hemifacial atrophy.

NO LEVEL ASSIGNED

This journal requires that authors 42 assign a level of evidence to each submission to which 43 Evidence-Based Medicine rankings are applicable. This 44 excludes Review Articles, Book Reviews, and manuscripts 45 that concern Basic Science, Animal Studies, Cadaver 46 Studies, and Experimental Studies. For a full description of 47 these Evidence-Based Medicine ratings, please refer to the 48 Table of Contents or the online Instructions to Authors 49 https://www.springer.com/00266 .

Non-coding RNAs in malaria infection

Malaria is one of the most severe infectious diseases affecting humans and it is caused by protozoan pathogens of the species Plasmodium (spp.). The malaria parasite Plasmodium is characterized by a complex, multistage life cycle that requires tight gene regulation which allows for host invasion and defense against host immune responses. Unfortunately, the mechanisms regulating gene expression during Plasmodium infection remain largely elusive, though several lines of evidence implicate a major involvement of non-coding RNAs (ncRNAs). The ncRNAs have been found to play a key role in regulating transcriptional and post-transcriptional events in a broad range of organisms including Plasmodium. In Plasmodium ncRNAs have been shown to regulate key events in the multistage life cycle and virulence ability. Here we review recent progress involving ncRNAs (microRNAs, long non-coding RNAs, and circular RNAs) and their role as regulators of gene expression during Plasmodium infection in human hosts with focus on the possibility of using these molecules as biomarkers for monitoring disease status. We also discuss the surprising function of ncRNAs in mediating the complex interplay between parasite and human host and future perspectives of the field. This article is categorized under: RNA in Disease and Development > RNA in Disease.

Reactive and Senescent Astroglial Phenotypes as Hallmarks of Brain Pathologies

Astrocytes, as the most abundant glial cells in the central nervous system, are tightly integrated into neural networks and participate in numerous aspects of brain physiology and pathology. They are the main homeostatic cells in the central nervous system, and the loss of astrocyte physiological functions and/or gain of pro-inflammatory functions, due to their reactivation or cellular senescence, can have profound impacts on the surrounding microenvironment with pathological outcomes. Although the importance of astrocytes is generally recognized, and both senescence and reactive astrogliosis have been extensively reviewed independently, there are only a few comparative overviews of these complex processes. In this review, we summarize the latest data regarding astrocyte reactivation and senescence, and outline similarities and differences between these phenotypes from morphological, functional, and molecular points of view. A special focus has been given to neurodegenerative diseases, where these phenotypic alternations of astrocytes are significantly implicated. We also summarize current perspectives regarding new advances in model systems based on astrocytes as well as data pointing to these glial cells as potential therapeutic targets.

Endothelial Senescence: A New Age in Pulmonary Hypertension

Pulmonary hypertension is an enigmatic, deleterious disease driven by multiple heterogeneous causes with a burgeoning proportion of older patients with complex, chronic comorbidities without adequate treatment options. The underlying endothelial pathophenotypes that direct vasoconstriction and panvascular remodeling remain both controversial and incompletely defined. This review discusses emerging concepts centered on endothelial senescence in pulmonary vascular disease. This principle proposes a more heterogeneous, dynamic pulmonary endothelium in disease; it provides a potentially unifying feature of endothelial dysfunction in pulmonary hypertension irrespective of cause; and it supports a clinically relevant link between aging and pulmonary hypertension like other chronic illnesses. Thus, taking cues from studies on aging and age-related diseases, we present possible opportunities and barriers to diagnostic and therapeutic targeting of senescence in pulmonary hypertension.

New insights of epigenetics in vascular and cellular senescence

Vascular senescence plays a vital role in cardiovascular diseases and it is closely related to cellular senescence. At the molecular level, aging begins with a single cell, and it is characterized by telomere shortening, mitochondrial dysfunction, stem cell exhaustion, epigenetic changes, and so on. Epigenetics is an independent discipline that modifies DNA activity without altering the DNA sequence. The application of epigenetics helps to alleviate the occurrence of human diseases, inhibit senescence, and even inhibit tumor occurrence. Epigenetics mainly includes the modification of DNA, histone, and noncoding RNA. Herein, the application of epigenetics in vascular senescence and aging has been reviewed to provide the prospects and innovative inspirations for future research.

Footprints of microRNAs in Cancer Biology

MicroRNAs (miRNAs) are short non-coding RNAs involved in post-transcriptional gene regulation. Over the past years, various studies have demonstrated the role of aberrant miRNA expression in the onset of cancer. The mechanisms by which miRNA exerts its cancer-promoting or inhibitory effects are apparent through the various cancer hallmarks, which include selective proliferative advantage, altered stress response, vascularization, invasion and metastasis, metabolic rewiring, the tumor microenvironment and immune modulation; therefore, this review aims to highlight the association between miRNAs and the various cancer hallmarks by dissecting the mechanisms of miRNA regulation in each hallmark separately. It is hoped that the information presented herein will provide further insights regarding the role of cancer and serve as a guideline to evaluate the potential of microRNAs to be utilized as biomarkers and therapeutic targets on a larger scale in cancer research.

CircRNA: A novel potential strategy to treat thyroid cancer (Review)

Thyroid cancer (TC) is the most common type of endocrine cancer. Over the last 50 years, the global incidence of TC has been increasing. The survival rate of TC is higher than that of most other types of cancer, but it depends on numerous factors, including the specific type of TC and stage of the disease. Circular RNAs (circRNAs) are a new class of long noncoding RNA with a closed loop structure that have a critical role in the complex gene regulatory network that controls the emergence of TC. The most important function of circRNAs is their ability to specifically bind to microRNAs. In addition, the biological functions of circRNAs also include interactions with proteins, regulation of the transcription of genes and acting as translation templates. Based on the characteristics of circRNAs, they have been identified as potential biomarkers for the diagnosis of tumors. In the present review, the function and significance of circRNAs and their potential clinical implications for TC were summarized. Furthermore, possible treatment approaches involving the use of mesenchymal stem cells (MSCs) and exosomes derived from MSCs as carriers to load and transport circRNAs were discussed.

Reduction of lamin B receptor levels by miR-340-5p disrupts chromatin, promotes cell senescence and enhances senolysis

A major stress response influenced by microRNAs (miRNAs) is senescence, a state of indefinite growth arrest triggered by sublethal cell damage. Here, through bioinformatic analysis and experimental validation, we identified miR-340-5p as a novel miRNA that foments cellular senescence. miR-340-5p was highly abundant in diverse senescence models, and miR-340-5p overexpression in proliferating cells rendered them senescent. Among the target mRNAs, miR-340-5p prominently reduced the levels of LBR mRNA, encoding lamin B receptor (LBR). Loss of LBR by ectopic overexpression of miR-340-5p derepressed heterochromatin in lamina-associated domains, promoting the expression of DNA repetitive elements characteristic of senescence. Importantly, overexpressing miR-340-5p enhanced cellular sensitivity to senolytic compounds, while antagonization of miR-340-5p reduced senescent cell markers and engendered resistance to senolytic-induced cell death. We propose that miR-340-5p can be exploited for removing senescent cells to restore tissue homeostasis and mitigate damage by senescent cells in pathologies of human aging.

[Research progress of cellular senescence in the pathogenesis of osteoarthritis]

Objective

To review the pathological effects of cellular senescence in the occurrence and development of osteoarthritis (OA) and potential therapeutic targets.

Methods

The role of chondrocyte senescence, synovial cell senescence, mesenchymal stem cells senescence in OA, and the biological mechanism and progress of chondrocyte senescence were summarized by consulting relevant domestic and abroad literature.

Results

The existing evidence has basically made clear that chondrocyte senescence, mesenchymal stem cells senescence, and cartilage repair abnormalities, and the occurrence and development of OA have a certain causal relationship, and the role of the senescence of synovial cells, especially synovial macrophages in OA is still unclear. Transcription factors and epigenetics are the main mechanisms that regulate the upstream pathways of cellular senescence. Signal communication between cells can promote the appearance of senescent phenotypes in healthy cells. Targeted elimination of senescent cells and promotion of mesenchymal stem cells rejuvenation can effectively delay the progress of OA.

Conclusion

Cellular senescence is an important biological phenomenon and potential therapeutic target in the occurrence and development of OA. In-depth study of its biological mechanism is helpful to the early prevention and treatment of OA.

Anti-SASP and anti-inflammatory activity of resveratrol, curcumin and β-caryophyllene association on human endothelial and monocytic cells

A challenging and promising new branch of aging-related research fields is the identification of natural compounds able to modulate the senescence-associated secretory phenotype (SASP), which characterizes senescent cells and can contribute to fuel the inflammaging. We investigated both the anti-SASP and anti-inflammatory activities of a nutritional supplement, namely Fenoxidol™, composed of turmeric extract bioCurcumin (bCUR), Polydatin (the natural glycosylated precursor of Resveratrol-RSV), and liposomal β-caryophyllene (BCP), in two human cellular models, such as the primary endothelial cell line, HUVECs and the monocytic cell line, THP-1. Replicative and Doxorubicin-induced senescent HUVECs, both chosen as cellular models of SASP, and lipopolysaccharides (LPS)-stimulated THP-1, selected as a model of the inflammatory response, were treated with the three single natural compounds or with a combination of them (MIX). In both senescent HUVEC models, MIX treatment significantly reduced IL-1β and IL-6 expression levels and p16^ink4a protein, and also increased SIRT1 protein level, as well as downregulated miR-146a and miR-21 expression, two of the so-called inflamma-miRNAs, more effectively than the single compounds. In THP-1 cells stimulated with LPS, the MIX showed a significant effect in decreasing IL-1β, IL-6, TNF-α, and miR-146a expression levels and Caspase-1 activation, in association with an up-regulation of SIRT1 protein, compared to the single compounds. Overall, our results suggest that the three analysed compounds can have a combined effect in restraining SASP in senescent HUVECs as well as the inflammatory response in LPS-stimulated THP-1 cells.

Pharmacological Targeting of Heme Oxygenase-1 in Osteoarthritis

Osteoarthritis (OA) is a common aging-associated disease that clinically manifests as joint pain, mobility limitations, and compromised quality of life. Today, OA treatment is limited to pain management and joint arthroplasty at the later stages of disease progression. OA pathogenesis is predominantly mediated by oxidative damage to joint cartilage extracellular matrix and local cells such as chondrocytes, osteoclasts, osteoblasts, and synovial fibroblasts. Under normal conditions, cells prevent the accumulation of reactive oxygen species (ROS) under oxidatively stressful conditions through their adaptive cytoprotective mechanisms. Heme oxygenase-1 (HO-1) is an iron-dependent cytoprotective enzyme that functions as the inducible form of HO. HO-1 and its metabolites carbon monoxide and biliverdin contribute towards the maintenance of redox homeostasis. HO-1 expression is primarily regulated at the transcriptional level through transcriptional factor nuclear factor erythroid 2 (NF-E2)-related factor 2 (Nrf2), specificity protein 1 (Sp1), transcriptional repressor BTB-and-CNC homology 1 (Bach1), and epigenetic regulation. Several studies report that HO-1 expression can be regulated using various antioxidative factors and chemical compounds, suggesting therapeutic implications in OA pathogenesis as well as in the wider context of joint disease. Here, we review the protective role of HO-1 in OA with a focus on the regulatory mechanisms that mediate HO-1 activity.

miRNA, lncRNA and circRNA: Targeted Molecules Full of Therapeutic Prospects in the Development of Diabetic Retinopathy

Diabetic retinopathy (DR) is a common diabetic complication and the main cause of blindness worldwide, which seriously affects the quality of life of patients. Studies have shown that noncoding RNA (ncRNA) has distinct differentiated expression in DR and plays an important role in the occurrence and development of DR. ncRNAs represented by microRNAs (miRNAs), lncRNAs (lncRNAs), and circRNAs (circRNAs) have been shown to be widely involved in the regulation of gene expression and affect multiple biological processes of retinopathy. This article will review three RNAs related to the occurrence and development of DR on the basis of previous studies (especially their effects on retinal microangiopathy, retinal pigment epithelial cells, and retinal nerve cells) and discuss their underlying mechanisms and connections. Overall, this review will help us better understand the role of ncRNAs in the occurrence and development of DR and provide ideas for exploring potential therapeutic directions and targets.

The miR-623/CXCL12 axis inhibits LPS-induced nucleus pulposus cell apoptosis and senescence

Nucleus pulposus cell (NPC) is the major cell type maintaining the physiological function of intervertebral discs by producing extracellular matrix (ECM). NPC apoptosis and senescence together contribute to NPC loss, finally leading to intervertebral disc degeneration (IDD). Herein, miR-623 showed to be downregulated within IDD tissue samples according to both bioinformatics and experimental analyses. In LPS-injured NPCs, miR-623 overexpression promoted LPS-suppressed cell proliferation; moreover, miR-623 overexpression inhibited cell apoptosis and senescence, increased ECM secretion, and reduced levels of inflammatory factors. In contrast to miR-623, CXCL12 expression was significantly upregulated in IDD tissues; miR-623 directly bound CXCL12 to inhibit its expression. In LPS-stimulated NPCs, CXCL12 silencing also LPS-induced changes in cell proliferation, cell senescence, ECM secretion, and inflammatory factor levels. More importantly, CXCL12 overexpression aggravated LPS-induced changes and significantly reversed the protective effects of miR-623 overexpression. In conclusion, the miR-623/CXCL12 axis could affect NPC apoptosis and senescence, ECM deposition, and inflammatory factor levels under LPS stimulation in vitro. The p65 signaling might be involved.

Magnetic nanoparticle-based amplification of microRNA detection in body fluids for early disease diagnosis

Circulating biomarkers such as microRNAs (miRNAs), short noncoding RNA strands, represent prognostic and diagnostic indicators for a variety of physiological disorders making their detection and quantification an attractive approach for minimally invasive early disease diagnosis. However, highly sensitive and selective detection methods are required given the generally low abundance of miRNAs in body fluids together with the presence of large amounts of other potentially interfering biomolecules. Although a variety of miRNA isolation and detection methods have been established in clinics, they usually require trained personnel and often constitute labor-, time- and cost-intensive approaches. During the last years, nanoparticle-based biosensors have received increasing attention due to their superior detection efficiency even in very low concentration regimes. This is based on their unique physicochemical properties in combination with their high surface area that allows for the immobilization of multiple recognition sites resulting in fast and effective recognition of analytes. Among various materials, magnetic nanoparticles have been identified as useful tools for the separation, concentration, and detection of miRNAs. Here, we review state-of-the-art technology with regard to magnetic particle-based miRNA detection from body fluids, critically discussing challenges and future perspective of such biosensors while comparing their handling, sensitivity as well as selectivity against the established miRNA isolation and detection methods.

Aging: a New Perspective on an Old Issue

The world is undergoing a profound demographic change with a rapid increase in the prevalence of aged individuals. The finitude of life, the burden of senescence and the search for strategies to prolong human life span have troubled humanity since ancient times. However, only in the past few decades we started to understand how organisms age and how life span can be manipulated. Here I give an historical perspective of the aging field and conclude with the notion that aging is controlled by signals from the adipose tissue which are tightly controlled by small non-coding RNAs such as miRNAs.

Cell senescence and fibrotic lung diseases

Idiopathic pulmonary fibrosis (IPF) is a progressive fatal lung disorder with an unknown etiology and very limited therapeutic options. The incidence and severity of IPF increase with advanced age, suggesting that aging is a major risk factor for IPF. The mechanism underlying the aging-related susceptibility to IPF, however, remains unclear. Cellular senescence, a permanent arrest of cell growth, has been increasingly recognized as an important contributor to aging and aging-related diseases, including IPF. Senescent cells have been identified in IPF lungs and in experimental lung fibrosis models. Removal of senescent cells pharmacologically or genetically improves lung function and reverses pulmonary fibrosis induced by different stimuli in experimental fibrosis models. Treatment with senolytic drugs also improves clinical symptoms in IPF patients. These intriguing findings suggest that cellular senescence contributes importantly to the pathogenesis of fibrotic lung diseases and targeting senescent cells may represent a novel approach for the treatment of fibrotic lung disorders. In this mini review, we summarize the recent advance in the field regarding the role of cellular senescence in fibrotic lung diseases, with a focus on IPF.

A global view of the miRNA-mitophagy connexion

Mitochondria are highly dynamics organelles that provide the necessary energy for cellular functions. However, when they are dysfunctional, they can, by contrast, be very harmful for the cell. Mitophagy ensures their recycling and preserves cell performance. This mechanism is particularly important in neurons because they use a lot of energy. Failed mitophagy can thus affect the development of neurons and lead to brain problems. In this regard, a tight regulation of this process is needed. In recent years microRNAs, as regulators of several biological processes, have attracted attention in the field of mitophagy. In this review, we focused on the studies that highlight the miRNAs implicated in the regulation of mitophagic pathways. In particular, we described the first study carried out 7 years ago, in the context of mitophagy during erythroid differentiation. Next, we have cited all the other works to date on microRNAs and mitophagy regulation. Finally, we have underlined the importance of these discoveries in order to define new therapeutic approaches in the context of age-related diseases involving mitochondrial dysfunctions, such as cancers and neurodegenerative diseases.

Cellular Senescence as a Mechanism and Target in Chronic Lung Diseases

Cellular senescence is now considered an important driving mechanism for chronic lung diseases, particularly chronic obstructive pulmonary disease (COPD) and idiopathic pulmonary fibrosis. Cellular senescence is due to replicative and stress-related senescence with activation of p53 and p16^INK4a, respectively, leading to activation of p21^CIP1 and cell cycle arrest. Senescent cells secrete multiple inflammatory proteins known as the senescence-associated secretory phenotype, leading to low-grade chronic inflammation, which further drives senescence. Loss of key antiaging molecules sirtuin-1 and sirtuin-6 may be important in acceleration of aging and arises from oxidative stress reducing phosphatase PTEN (phosphatase tensin homolog), thereby activating PI3K (phosphoinositide-3-kinase) and mTOR (mammalian target of rapamycin). MicroRNA-34a (miR-34a), which is regulated by PI3K-mTOR signaling, plays a pivotal role in reducing sirtuin-1/6, and its inhibition with an antagomir results in their restoration, reducing markers of senescence, reducing senescence-associated secretory phenotype, and reversing cell cycle arrest in epithelial cells from peripheral airways of patients with COPD. miR-570 is also involved in reduction of sirtuin-1 and cellular senescence and is activated by p38 mitogen-activated protein kinase. These miRNAs may be released from cells in extracellular vesicles that are taken up by other cells, thereby spreading senescence locally within the lung but also outside the lung through the circulation; this may account for comorbidities of COPD and other lung diseases. Understanding the mechanisms of cellular senescence may result in new treatments for chronic lung disease, either by inhibiting PI3K-mTOR signaling, by inhibiting specific miRNAs, or by deletion of senescent cells with senolytic therapies, already shown to be effective in experimental lung fibrosis.

Small extracellular vesicles deliver miR-21 and miR-217 as pro-senescence effectors to endothelial cells

The role of epigenetics in endothelial cell senescence is a cutting-edge topic in ageing research. However, little is known of the relative contribution to pro-senescence signal propagation provided by microRNAs shuttled by extracellular vesicles (EVs) released from senescent cells. Analysis of microRNA and DNA methylation profiles in non-senescent (control) and senescent (SEN) human umbilical vein endothelial cells (HUVECs), and microRNA profiling of their cognate small EVs (sEVs) and large EVs demonstrated that SEN cells released a significantly greater sEV number than control cells. sEVs were enriched in miR-21-5p and miR-217, which target DNMT1 and SIRT1. Treatment of control cells with SEN sEVs induced a miR-21/miR-217-related impairment of DNMT1-SIRT1 expression, the reduction of proliferation markers, the acquisition of a senescent phenotype and a partial demethylation of the locus encoding for miR-21. MicroRNA profiling of sEVs from plasma of healthy subjects aged 40-100 years showed an inverse U-shaped age-related trend for miR-21-5p, consistent with senescence-associated biomarker profiles. Our findings suggest that miR-21-5p/miR-217 carried by SEN sEVs spread pro-senescence signals, affecting DNA methylation and cell replication.