Alteration of N-glycosylation of CDON promotes H2O2-induced DNA damage in H9c2 cardiomyocytes.

Protein glycosylation is involved in DNA damage. Recently, DNA damage has been connected with the pathogenesis of heart failure. Cell adhesion associated, oncogene regulated (CDON), considered as an N-linked glycoprotein, is a transmembrane receptor for modulating cardiac function. But the role of CDON and its glycosylation in DNA damage remains unknown. In this study, we found that the knockdown of CDON caused DNA double-strand breaks as indicated by an increase in phosphorylated histone H2AX (γH2AX) protein level, immunofluorescent intensity of γH2AX and tail DNA moment in H9c2 cardiomyocytes. Conversely, overexpression of CDON leads to decreasing DNA damage induced by hydrogen peroxide (H2O2) and upregulating the expression of genes related to DNA repair pathways-homologous recombination (HR) and non-homologous end joining (NHEJ). Moreover, we expressed nine predicted N-glycosylation site mutants in H9c2 cells prior to treatment with H2O2. The results showed that mutation of N-glycosylation sites (N99Q, N179Q, and N870Q) increased the accumulation of DNA damage and downregulated the expression of HR-related genes, demonstrating that CDON N-glycosylation on DNA damage is site-specific and these specific N-glycan sites may regulate HR repair-related transcript abundance of genes. Our data highlight that N-glycosylation of CDON is critical to cardiomyocyte DNA lesion. It may uncover the potential strategies targeting DNA damage pathway in heart disease.

Age-Disturbed Vascular Extracellular Matrix Links to Abdominal Aortic Aneurysms.

Abdominal aortic aneurysm (AAA) is a common but life-threatening vascular condition in men at an advanced age. However, the underlying mechanisms of age-increased incidence and mortality of AAA remain elusive. Here, we performed RNA sequencing (RNA-seq) of mouse aortas from males (young: 3-month, n = 4 vs old: 23-month, n = 4) and integrated with the data sets of human aortas (young: 20-39, n = 47 vs old: 60-79 years, n = 92) from GTEx project and the data set (GSE183464) for AAA to search for age-shifted aortic aneurysm genes, their relevant biological processes, and signaling pathways. Angiotensin II-induced AAA in mice was used to verify the critical findings. We found 1 001 genes transcriptionally changed with ages in both mouse and human. Most age-increased genes were enriched intracellularly and the relevant biological processes included mitochondrial function and translational controls, whereas the age-decreased genes were largely localized in extracellular regions and cell periphery and the involved biological processes were associated with extracellular matrix (ECM). Fifty-one were known genes for AAA and found dominantly in extracellular region. The common age-shifted vascular genes and known aortic aneurysm genes had shared functional influences on ECM organization, apoptosis, and angiogenesis. Aorta with angiotensin II-induced AAA exhibited similar phenotypic changes in ECM to that in old mice. Together, we present a conserved transcriptional signature for aortic aging and provide evidence that mitochondrial dysfunction and the imbalanced ribosomal homeostasis act likely as driven-forces for aortic aging and age-disturbed ECM is the substrate for developing AAA.

Metabolomic profiles and differential metabolites of volatile components in Citrus aurantium Changshan-huyou pericarp during different growth and development stages.

Citrus fruits possess a distinctive aroma and flavor, with Citrus aurantium Changshan-huyou (CACH) standing out due to their considerable edible and medicinal value. However, the volatile components (VOCs) in the CACH pericarp (CP) remain underexplored. In this study, gas chromatography-mass spectrometry (GC-MS) was utilized to qualitatively analyze VOCs in 27 CP samples across different growth stages. A total of 544 VOCs were identified, including 91 terpenoids. The types, quantities and distributions of VOCs were conducted. Detailed discussions on the major terpenoids in CP were also presented. A metabolomics approach combining multivariate statistical analysis with univariate analysis was employed for screening the differential metabolites. The study provides comprehensive insights into the VOCs in CP and citrus plants. Moreover, it delivers the first in-depth analysis of differential metabolites in CP throughout the entire CACH growth and development process, laying a foundation for ongoing research and development of the VOCs in CP.

Histone ß-hydroxybutyrylation is critical in reversal of sarcopenia.

Sarcopenia, a leading cause for global disability and mortality, is an age-related muscular disorder, characterized by accelerated muscle mass loss and functional decline. It is known that caloric restriction (CR), ketogenic diet or endurance exercise lessen sarcopenia and elevate circulating ß-hydroxybutyrate (ß-HB) levels. Whether the elevated ß-HB is essential to the reversal of sarcopenia, however, remains unclear. Here we show in both Caenorhabditis elegans and mouse models that an increase of ß-HB reverse myofiber atrophy and improves motor functions at advanced ages. ß-HB-induced histone lysine ß-hydroxybutyrylation (Kbhb) is indispensable for the reversal of sarcopenia. Histone Kbhb enhances transcription of genes associated with mitochondrial pathways, including oxidative phosphorylation, ATP metabolic process and aerobic respiration. This ultimately leads to improve mitochondrial integrity and enhance mitochondrial respiration. The histone Kbhb are validated in mouse model with CR. Thus, we demonstrate that ß-HB induces histone Kbhb, increases mitochondrial function, and reverses sarcopenia.

A dual responsive nitric oxide / ß-lapachone co-delivery platform for redox imbalance-enhanced tumor therapy.

Nitric oxide (NO) / ß-Lapachone (Lap) combined therapy by causing oxidative stress is an effective tumor therapy strategy. Herein, a dual-responsive lipid nanoparticles (LNPs) LSNO for NO / Lap co-delivery were constructed from the zinc-coordinated lipid (DSNO(Zn)) and the hydrophobic drug Lap in the presence of helper lipids (DOPE and DSPE-PEG2000). The zinc-coordinated structure in LSNO might elevate the Zn2+ content in tumor cells, contributing to antioxidant imbalance. The fluorescent assays proved the light-triggered NO release and fluorescent self-reporting abilities of LSNO. In addition, the LNPs had good drug release behavior under high concentration of GSH, indicating the NO / drug co-delivery capacity. In vitro antitumor assays showed that the NO / Lap combination treatment group could induce more significant tumor cell growth inhibition and cell apoptosis than individual NO or Lap treatment. The following mechanism studies revealed that NO / Lap combination treatment led to distinct oxidative stress by producing reactive oxygen species (ROS) and peroxynitrite anion (ONOO-). On the other hand, the intracellular redox balance could be further disrupted by Lap-induced NADPH consumption and Zn2+ / NO-induced reductase activities downregulation, thus promoting the degree of cell damage. Besides, it was also found that NO and Lap could directly damage nuclear DNA and induce mitochondrial dysfunction, thereby leading to caspase-3 activation and tumor cell death. These results proved that LSNO could serve as a promising multifunctional tumor therapy platform.

ROS-Responsive Bola-Lipid Nanoparticles as a Codelivery System for Gene/Photodynamic Combination Therapy.

The nonviral delivery systems that combine genes with photosensitizers for multimodal tumor gene/photodynamic therapy (PDT) have attracted much attention. In this study, a series of ROS-sensitive cationic bola-lipids were applied for the gene/photosensitizer codelivery. Zn-DPA was introduced as a cationic headgroup to enhance DNA binding, while the hydrophobic linking chains may facilitate the formation of lipid nanoparticles (LNP) and the encapsulation of photosensitizer Ce6. The length of the hydrophobic chain played an important role in the gene transfection process, and 14-TDZn containing the longest chains showed better DNA condensation, gene transfection, and cellular uptake. 14-TDZn LNPs could well load photosensitizer Ce6 to form 14-TDC without a loss of gene delivery efficiency. 14-TDC was used for codelivery of p53 and Ce6 to achieve enhanced therapeutic effects on the tumor cell proliferation inhibition and apoptosis. Results showed that the codelivery system was more effective in the inhibition of tumor cell proliferation than individual p53 or Ce6 monotherapy. Mechanism studies showed that the production of ROS after Ce6 irradiation could increase the accumulation of p53 protein in tumor cells, thereby promoting caspase-3 activation and inducing apoptosis, indicating some synergistic effect. These results demonstrated that 14-TDC may serve as a promising nanocarrier for gene/PDT combination therapy.

Genome-Wide Search Links Senescence-Associated Secretory Proteins With Susceptibility for Coronary Artery Disease in Mouse and Human.

Advanced age is an independent risk factor for coronary artery disease (CAD), the leading global cause of mortality. Senescent vascular cells in the atherosclerotic plaques exhibit senescence-associated secretory phenotype (SASP). How SASP contributes to atherosclerosis and CAD, however, remains unclear. Here, we integrated RNA-array datasets of senescent human coronary arterial endothelial cells (HCAECs) and aortic smooth muscle cells (HASMCs) as well as genome-wide association data for CAD. We identified 26 genes from HCAECs and 6 genes from HASMCs related to SASP and CAD in both in-house and published datasets. Of which, Cystatin C (CST3), a CAD susceptibility gene, was found to be expressed in both HCAECs and HASMCs, thus, it was prioritized for further investigation. We demonstrated it was significantly elevated in senescent vascular cells, aged arteries, and early atherosclerosis. In vitro experiments showed that CST3 enhances the monocyte-endothelial cell adhesion. Additionally, ligand-receptor pairing analyses revealed two important pathways, COL4A1-ITGA1 and LPL-LRP1 pathways, linked to the critical processes in the development of atherosclerosis, including cell adhesion, inflammation response, extracellular matrix organization, and lipid metabolism. We further demonstrated a reduced monocyte-endothelial cell adhesion following the knockdown of COL4A1 or ITGA1 and a significantly increased expression of COL4A1, ITGA1, and LPL in arterial intima of aged mice and ApoE-/- mice. Our findings demonstrate that vascular cell-derived SASP proteins increase the CAD susceptibility and identify CST3 functionally contributing to atherosclerosis.

Genetic associations with longevity are on average stronger in females than in males.

It is long observed that females tend to live longer than males in nearly every country. However, the underlying mechanism remains elusive. In this study, we discovered that genetic associations with longevity are on average stronger in females than in males through bio-demographic analyses of genome-wide association studies (GWAS) dataset of 2178 centenarians and 2299 middle-age controls of Chinese Longitudinal Healthy Longevity Study (CLHLS). This discovery is replicated across North and South regions of China, and is further confirmed by North-South discovery/replication analyses of different and independent datasets of Chinese healthy aging candidate genes with CLHLS participants who are not in CLHLS GWAS, including 2972 centenarians and 1992 middle-age controls. Our polygenic risk score analyses of eight exclusive groups of sex-specific genes, analyses of sex-specific and not-sex-specific individual genes, and Genome-wide Complex Trait Analysis using all SNPs all reconfirm that genetic associations with longevity are on average stronger in females than in males. Our discovery/replication analyses are based on genetic datasets of in total 5150 centenarians and compatible middle-age controls, which comprises the worldwide largest sample of centenarians. The present study's findings may partially explain the well-known male-female health-survival paradox and suggest that genetic variants may be associated with different reactions between males and females to the same vaccine, drug treatment and/or nutritional intervention. Thus, our findings provide evidence to steer away from traditional view that "one-size-fits-all" for clinical interventions, and to consider sex differences for improving healthcare efficiency. We suggest future investigations focusing on effects of interactions between sex-specific genetic variants and environment on longevity as well as biological function.

Handelin alleviates cachexia- and aging-induced skeletal muscle atrophy by improving protein homeostasis and inhibiting inflammation.

BACKGROUND: Handelin is a bioactive compound from Chrysanthemum indicum L. that improves motor function and muscle integrity during aging in Caenorhabditis elegans. This study aimed to further evaluate the protective effects and molecular mechanisms of handelin in a mouse muscle atrophy model induced by cachexia and aging. METHODS: A tumour necrosis factor (TNF)-α-induced atrophy model was used to examine handelin activity in cultured C2C12 myotubes in vitro. Lipopolysaccharide (LPS)-treated 8-week-old model mice and 23-month-old (aged) mice were used to examine the therapeutic effects of handelin on cachexia- and aging-induced muscle atrophy, respectively, in vivo. Protein and mRNA expressions were analysed by Western blotting, ELISA and quantitative PCR, respectively. Skeletal muscle mass was measured by histological analysis. RESULTS: Handelin treatment resulted in an upregulation of protein levels of early (MyoD and myogenin) and late (myosin heavy chain, MyHC) differentiation markers in C2C12 myotubes (P < 0.05), and enhanced mitochondrial respiratory (P < 0.05). In TNF-α-induced myotube atrophy model, handelin maintained MyHC protein levels, increased insulin-like growth factor (Igf1) mRNA expression and phosphorylated protein kinase B protein levels (P < 0.05). Handelin also reduced atrogin-1 expression, inhibited nuclear factor-κB activation and reduced mRNA levels of interleukin (Il)6, Il1b and chemokine ligand 1 (Cxcl1) (P < 0.05). In LPS-treated mice, handelin increased body weight (P < 0.05), the weight (P < 0.01) and cross-sectional area (CSA) of the soleus muscle (P < 0.0001) and improved motor function (P < 0.05). In aged mice, handelin slightly increased the weight of the tibialis anterior muscle (P = 0.06) and CSA of the tibialis anterior and gastrocnemius muscles (P < 0.0001). In the tibialis anterior muscle of aged mice, handelin upregulated mRNA levels of Igf1 (P < 0.01), anti-inflammatory cytokine Il10 (P < 0.01), mitochondrial biogenesis genes (P < 0.05) and antioxidant-related enzymes (P < 0.05) and strengthened Sod and Cat enzyme activity (P < 0.05). Handelin also reduced lipid peroxidation and protein carbonylation, downregulated mRNA levels of Fbxo32, Mstn, Cxcl1, Il1b and Tnf (P < 0.05), and decreased IL-1ß levels in serum (P < 0.05). Knockdown of Hsp70 or using an Hsp70 inhibitor abolished the ameliorating effects of handelin on myotube atrophy. CONCLUSIONS: Handelin ameliorated cachexia- and aging-induced skeletal muscle atrophy in vitro and in vivo, by maintaining homeostasis of protein synthesis and degradation, possibly by inhibiting inflammation. Handelin is a potentially promising drug candidate for the treatment of muscle wasting.

[Establishment of comprehensive evaluation models of physical fitness of the elderly based on machine learning].

The present study aims to establish comprehensive evaluation models of physical fitness of the elderly based on machine learning, and provide an important basis to monitor the elderly's physique. Through stratified sampling, the elderly aged 60 years and above were selected from 10 communities in Nanchang City. The physical fitness of the elderly was measured by the comprehensive physical assessment scale based on our previous study. Fuzzy neural network (FNN), support vector machine (SVM) and random forest (RF) models for comprehensive physical evaluation of the elderly people in communities were constructed respectively. The accuracy, sensitivity and specificity of the comprehensive physical fitness evaluation models constructed by FNN, SVM and RF were above 0.85, 0.75 and 0.89, respectively, with the FNN model possessing the best prediction performance. FNN, RF and SVM models are valuable in the comprehensive evaluation and prediction of physical fitness, which can be used as tools to carry out physical evaluation of the elderly.

[Development of comprehensive vitality scale for the elderly based on classical test theory and analytic hierarchy process].

The present study aims to construct an elderly vitality index evaluation system and develop a comprehensive vitality evaluation scale for the elderly to reasonably evaluate the vitality level of the elderly in China, so as to provide a reference for promoting the realization of "active aging" and "healthy aging". Literature research and in-depth interview were used to collect the senile vitality sensitive indexes. The indexes were screened and corrected by Delphi expert consultation method, item analysis method based on classical test theory, factor analysis method, and reliability and validity analysis method. The analytic hierarchy process was used to calculate the weight of each level of indexes. An elderly vitality evaluation system including 4 first-level indexes and 24 second-level indexes was constructed. The consistency test results of all levels of indicators showed that the consistency index (CI) and consistent ratio (CR) were both less than 0.1, which met the requirements and showed satisfactory consistency. The weights of exercise vitality, nutritional vitality, psychological vitality and social vitality were 0.263, 0.141, 0.455 and 0.141, respectively. In conclusion, the comprehensive vitality scale constructed for the Chinese elderly is reliable and scientific, and can be used to evaluate the vitality of the elderly.

Vascular Aging: Assessment and Intervention.

Vascular aging represents a collection of structural and functional changes in a blood vessel with advancing age, including increased stiffness, vascular wall remodeling, loss of angiogenic ability, and endothelium-dependent vasodilation dysfunction. These age-related alterations may occur earlier in those who are at risk for or have cardiovascular diseases, therefore, are defined as early or premature vascular aging. Vascular aging contributes independently to cardio-cerebral vascular diseases (CCVDs). Thus, early diagnosis and interventions targeting vascular aging are of paramount importance in the delay or prevention of CCVDs. Here, we review the direct assessment of vascular aging by examining parameters that reflect changes in structure, function, or their compliance with age including arterial wall thickness and lumen diameter, endothelium-dependent vasodilation, arterial stiffness as well as indirect assessment through pathological studies of biomarkers including endothelial progenitor cell, lymphocytic telomeres, advanced glycation end-products, and C-reactive protein. Further, we evaluate how different types of interventions including lifestyle mediation, such as caloric restriction and salt intake, and treatments for hypertension, diabetes, and hyperlipidemia affect age-related vascular changes. As a single parameter or intervention targets only a certain vascular physiological change, it is recommended to use multiple parameters to evaluate and design intervention approaches accordingly to prevent systemic vascular aging in clinical practices or population-based studies.

Inhibiting HIF-1 signaling alleviates HTRA1-induced RPE senescence in retinal degeneration.

BACKGROUND: Age-related macular degeneration (AMD), characterized by the degeneration of retinal pigment epithelium (RPE) and photoreceptors, is the leading cause of irreversible vision impairment among the elderly. RPE senescence is an important contributor to AMD and has become a potential target for AMD therapy. HTRA1 is one of the most significant susceptibility genes in AMD, however, the correlation between HTRA1 and RPE senescence hasn't been investigated in the pathogenesis of AMD. METHODS: Western blotting and immunohistochemistry were used to detect HTRA1 expression in WT and transgenic mice overexpressing human HTRA1 (hHTRA1-Tg mice). RT-qPCR was used to detect the SASP in hHTRA1-Tg mice and ARPE-19 cells infected with HTRA1. TEM, SA-ß-gal was used to detect the mitochondria and senescence in RPE. Retinal degeneration of mice was investigated by fundus photography, FFA, SD-OCT and ERG. The RNA-Seq dataset of ARPE-19 cells treated with adv-HTRA1 versus adv-NC were analyzed. Mitochondrial respiration and glycolytic capacity in ARPE-19 cells were measured using OCR and ECAR. Hypoxia of ARPE-19 cells was detected using EF5 Hypoxia Detection Kit. KC7F2 was used to reduce the HIF1α expression both in vitro and in vivo. RESULTS: In our study, we found that RPE senescence was facilitated in hHTRA1-Tg mice. And hHTRA1-Tg mice became more susceptible to NaIO3 in the development of oxidative stress-induced retinal degeneration. Similarly, overexpression of HTRA1 in ARPE-19 cells accelerated cellular senescence. Our RNA-seq revealed an overlap between HTRA1-induced differentially expressed genes associated with aging and those involved in mitochondrial function and hypoxia response in ARPE-19 cells. HTRA1 overexpression in ARPE-19 cells impaired mitochondrial function and augmented glycolytic capacity. Importantly, upregulation of HTRA1 remarkably activated HIF-1 signaling, shown as promoting HIF1α expression which mainly located in the nucleus. HIF1α translation inhibitor KC7F2 significantly prevented HTRA1-induced cellular senescence in ARPE-19 cells, as well as improved the visual function in hHTRA1-Tg mice treated with NaIO3. CONCLUSIONS: Our study showed elevated HTRA1 contributes to the pathogenesis of AMD by promoting cellular senescence in RPE through damaging mitochondrial function and activating HIF-1 signaling. It also pointed out that inhibition of HIF-1 signaling might serve as a potential therapeutic strategy for AMD. Video Abstract.

Lipoic Acid-Based Poly(disulfide)s as Versatile Biomolecule Delivery Vectors and the Application in Tumor Immunotherapy.

Intracellular delivery of therapeutic biomacromolecules, including nucleic acids and proteins, attracts extensive attention in biotherapeutics for various diseases. Herein, a strategy is proposed for the construction of poly(disulfide)s for the efficient delivery of both nucleic acids and proteins into cells. A convenient photo-cross-linking polymerization was adopted between disulfide bonds in two modified lipoic acid monomers (Zn coordinated with dipicolylamine analogue (ZnDPA) and guanidine (GUA)). The disulfide-containing main chain of the resulting poly(disulfide)s was responsive to reducing circumstance, facilitating the release of cargos. By screening the feeding ratio of ZnDPA and GUA, the resulting poly(disulfide)s exhibited better performance in the delivery of nucleic acids including plasmid DNA and siRNA than commercially available transfection reagents. Cellular uptake results revealed that the polymer/cargo complexes entered the cells mainly following a thiol-mediated uptake pathway. Meanwhile, the polymer could also efficiently deliver proteins into cells without an obvious loss of protein activity, showing the versatility of the poly(disulfide)s for the delivery of various biomacromolecules. Moreover, the in vivo therapeutic effect of the materials was verified in the E.G7-OVA tumor-bearing mice. Ovalbumin-based nanovaccine induced a strong cellular immune response, especially cytotoxic T lymphocyte cellular immune response, and inhibited tumor growth. These results revealed the promise of the poly(disulfide)s in the application of both gene therapy and immunotherapy.

Spleen-Targeted mRNA Delivery by Amphiphilic Carbon Dots for Tumor Immunotherapy.

In recent years, the application of mRNA vaccine-based tumor immunotherapy invigorated anti-tumor therapy. However, the low efficiency of mRNA delivery and the lack of targeting ability in vivo are the major obstacles to achieving highly efficient immunotherapy. In this work, we report a chemical library of amphiphilic carbon dots (ACDs) and the synthesized ACDs were applied to mRNA delivery, bio-imaging, and tumor immunotherapy. The ACDs can smoothly bind with mRNA to form ACDs@mRNA nanocomplexes, and the fluorescent properties of the ACDs afforded the nanoparticles with bio-imaging ability. By screening of the ACDs, O12-Tta-CDs were found to have optimal mRNA transfection efficiency and the ability of spleen-targeted delivery. In addition, O12-Tta-CDs can well transfect the immune cells and promote the maturation and antigen presentation of bone marrow-derived dendritic cells (BMDCs). Furthermore, O12-Tta-CDs@OVA-mRNA was successfully applied to inhibit tumor growth, and more specific T-cell infiltration was observed in spleen and tumors of mice after treatment in the E.G7-OVA tumor model. Besides, O12-Tta-CDs@OVA-mRNA also achieved a good therapeutic effect in tumor recurrence inhibition and tumor prophylactic experiments. This study provided a new direction for the design of mRNA vectors, which is promising in tumor immunotherapy.

Lack of NPR1 Increases Vascular Endothelial Adhesion through Induction of Integrin Beta 4.

Natriuretic peptide receptor 1 (NPR1) serves as a modulator of vascular endothelial homeostasis. Interactions between monocytes and endothelial cells may initiate endothelium dysfunction, which is known as an early hallmark of atherosclerosis. In this study, we performed RNA-sequencing analysis for the aorta of Npr1 knockout (Npr1+/-) mice and found that differentially expressed genes were significantly related to cell adhesion. This result was supported by an increased expression of intercellular adhesion molecule 1 (ICAM-1) in the aortic endothelium of Npr1+/- mice. Moreover, we observed that the knockdown of NPR1 increased ICAM-1 expression and promoted THP-1 monocyte adhesion to human umbilical vein endothelial cells (HUVECs). NPR1 overexpression decreased ICAM-1 expression and inhibited the adhesion of monocytes to HUVECs treated by TNF-α (a cell adhesion inducer). Further analysis showed that adhesion-related genes were enriched in the focal adhesion signaling pathway, in which integrin beta 4 (Itgb4) was determined as a key gene. Notably, ITGB4 expression increased in vascular endothelium of Npr1+/- mice and in NPR1-knockdown HUVECs. The deficiency of ITGB4 decreased ICAM-1 expression and attenuated monocyte adhesion to NPR1-knockdown endothelial cells. Additionally, a reduced NPR1 and an increased ITGB4 expression level were found in an atherosclerosis mouse model. In conclusion, our findings demonstrate that NPR1 deficiency increases vascular endothelial cell adhesion by stimulating ITGB4 expression, which may contribute to the development of atherosclerosis.

The landscape of aging.

Aging is characterized by a progressive deterioration of physiological integrity, leading to impaired functional ability and ultimately increased susceptibility to death. It is a major risk factor for chronic human diseases, including cardiovascular disease, diabetes, neurological degeneration, and cancer. Therefore, the growing emphasis on "healthy aging" raises a series of important questions in life and social sciences. In recent years, there has been unprecedented progress in aging research, particularly the discovery that the rate of aging is at least partly controlled by evolutionarily conserved genetic pathways and biological processes. In an attempt to bring full-fledged understanding to both the aging process and age-associated diseases, we review the descriptive, conceptual, and interventive aspects of the landscape of aging composed of a number of layers at the cellular, tissue, organ, organ system, and organismal levels.

Chronological attenuation of NPRA/PKG/AMPK signaling promotes vascular aging and elevates blood pressure.

Hypertension is common in elderly population. We designed to search comprehensively for genes that are chronologically shifted in their expressions and to define their contributions to vascular aging and hypertension. RNA sequencing was conducted to search for senescence-shifted transcripts in human umbilical vein endothelial cells (HUVECs). Small interfering RNA (siRNA), small-molecule drugs, CRISPR/Cas9 techniques, and imaging were used to determine genes' function and contributions to age-related phenotypes of the endothelial cell and blood vessel. Of 25 genes enriched in the term of "regulation of blood pressure," NPRA was changed most significantly. The decreased NPRA expression was replicated in aortas of aged mice. The knockdown of NPRA promoted HUVEC senescence and it decreased expressions of protein kinase cGMP-dependent 1 (PKG), sirtuin 1 (SIRT1), and endothelial nitric oxide synthase (eNOS). Suppression of NPRA also decreased the phosphorylation of AMP-activated protein kinase (AMPK) as well as the ratio of oxidized nicotinamide adenine dinucleotide (NAD+ )/reduced nicotinamide adenine dinucleotide (NADH) but increased the production of reactive oxygen species (ROS). 8-Br-cGMP (analog of cGMP), or AICAR (AMPK activator), counteracted the observed changes in HUVECs. The Npr1+/- mice presented an elevated systolic blood pressure and their vessels became insensitive to endothelial-dependent vasodilators. Further, vessels from Npr1+/- mice increased Cdkn1a but decreased eNos expressions. These phenotypes were rescued by intravenously administrated 8-Br-cGMP and viral overexpression of human PKG, respectively. In conclusion, we demonstrate NPRA/PKG/AMPK as a novel and critical signaling axis in the modulation of endothelial cell senescence, vascular aging, and hypertension.

ICAM-1-related noncoding RNA accelerates atherosclerosis by amplifying NF-κB signaling.

Long noncoding RNAs (lncRNAs) are critical regulators of inflammation with great potential as new therapeutic targets. However, the role of lncRNAs in early atherosclerosis remains poorly characterized. This study aimed to identify the key lncRNA players in activated endothelial cells (ECs). The lncRNAs in response to pro-inflammatory factors in ECs were screened through RNA sequencing. ICAM-1-related non-coding RNA (ICR) was identified as the most potential candidate for early atherosclerosis. ICR is essential for intercellular adhesion molecule-1 (ICAM1) expression, EC adhesion and migration. In a high fat diet-induced atherosclerosis model in mice, ICR is upregulated in the development of atherosclerosis. After intravenous injection of adenovirus carrying shRNA for mouse ICR, the atherosclerotic plaque area was markedly reduced with the declined expression of ICR and ICAM1. Mechanistically, ICR stabilized the mRNA of ICAM1 in quiescent ECs; while under inflammatory stress, ICR upregulated ICAM1 in a nuclear factor kappa B (NF-κB) dependent manner. RNA-seq analysis showed pro-inflammatory targets of NF-κB were regulated by ICR. Furthermore, the chromatin immunoprecipitation assays showed that p65 binds to ICR promoter and facilitates its transcription. Interestingly, ICR, in turn, promotes p65 accumulation and activity, forming a positive feedback loop to amplify NF-κB signaling. Preventing the degradation of p65 using proteasome inhibitors rescued the expression of NF-κB targets suppressed by ICR. Taken together, ICR acts as an accelerator to amplify NF-κB signaling in activated ECs and suppressing ICR is a promising early intervention for atherosclerosis through ICR/p65 loop blockade.