Age-related Gene Expression Research Articles

Effects of Cutting, Pruning, and Grafting on the Expression of Age-Related Genes in Larix kaempferi

Grafting, cutting, and pruning are important horticultural techniques widely used in the establishment of clonal forestry. After the application of these techniques, some properties of the plants change, however, the underlying molecular mechanisms are still unclear. In our previous study, 27 age-related transcripts were found to be expressed differentially between the juvenile vegetative (1- and 2-year-old) and adult reproductive (25- and 50-year-old) phases of Larix kaempferi. Here, we re-analyzed the 27 age-related transcripts, cloned their full-length cDNA sequences, and measured their responses to grafting, cutting, and pruning. After sequence analysis and cloning, 20 transcription factors were obtained and annotated, most of which were associated with reproductive development, and six (LaAGL2-1, LaAGL2-2, LaAGL2-3, LaSOC1-1, LaAGL11, and LaAP2-2) showed regular expression patterns with L. kaempferi aging. Based on the expression patterns of these transcription factors in L. kaempferi trees subjected to grafting, cutting, and pruning, we concluded that (1) cutting and pruning rejuvenate the plants and change their expression, and the effects of cutting on gene expression are detectable within 14 years, although the cutting seedlings are still maturing during these years; (2) within three months after grafting, the rootstock is more sensitive to grafting than the scion and readily becomes mature with the effect of the scion, while the scion is not readily rejuvenated by the effect of the rootstock; and (3) LaAGL2-2 and LaAGL2-3 are more sensitive to grafting, while LaAP2-2 is impervious to it. These findings not only provide potential molecular markers to assess the state of plants but also aid in studies of the molecular mechanisms of rejuvenation.

Photoaging Protective Effects of Ranunculus bulumei Methanol Extract.

Ultraviolet B (UVB) radiation is the main cause of photoaging processes including cellular senescence, skin drying, collagen degradation, melanogenesis, and inflammation. These responses occur because UVB induces a change in expression of aging-related genes through regulation of signal pathways such as that of mitogen-activated protein kinases- (MAPKs-) activator protein 1 (AP-1). Ranunculus bulumei, which is used as an herb in Indonesia, belongs to the Ranunculaceae family, which has been reported to perform various physiological effects including antioxidant and anti-inflammation. However, data on the pharmaceutical and cosmeceutical utility of Ranunculus bulumei have not been reported. Therefore, we evaluated the antiaging efficacy of RB-ME, a methanol extract of Ranunculus bulumei. Rb-ME attenuated MMP9 and COX-2 gene expression but enhanced SIRT1 and type-1 collagen in UVB-irradiated HaCaT cells. Rb-ME regulated these gene expressions through inhibition of p38 phosphorylation and inactivation of AP-1. In addition, mRNA expression of HAS-2 and -3, which are involved in skin hydration, was elevated in Rb-ME-treated HaCaT cells. Rb-ME also inhibited melanogenesis by suppression of tyrosinase, MITF, and TYRP-1 mRNA in B16F10 cells under α-MSH treatment. Taken together, these results indicate that Rb-ME has a protective effect on some UVB-induced skin photoaging events such as inflammation, collagen degradation, cellular senescence, skin drying, and melanin production through inhibition of the p38-AP-1 signal cascade, indicating that Rb-ME can be used as an active ingredient for antiaging cosmetics.

Age-related gene expression changes in lumbar spinal cord: Implications for neuropathic pain.

Clinically, pain has an uneven incidence throughout lifespan and impacts more on the elderly. In contrast, preclinical models of pathological pain have typically used juvenile or young adult animals to highlight the involvement of glial populations, proinflammatory cytokines, and chemokines in the onset and maintenance of pathological signalling in the spinal dorsal horn. The potential impact of this mismatch is also complicated by the growing appreciation that the aged central nervous system exists in a state of chronic inflammation because of enhanced proinflammatory cytokine/chemokine signalling and glial activation. To address this issue, we investigated the impact of aging on the expression of genes that have been associated with neuropathic pain, glial signalling, neurotransmission and neuroinflammation. We used qRT-PCR to quantify gene expression and focussed on the dorsal horn of the spinal cord as this is an important perturbation site in neuropathic pain. To control for global vs region-specific age-related changes in gene expression, the ventral half of the spinal cord was examined. Our results show that expression of proinflammatory chemokines, pattern recognition receptors, and neurotransmitter system components was significantly altered in aged (24-32 months) versus young mice (2-4 months). Notably, the magnitude and direction of these changes were spinal-cord region dependent. For example, expression of the chemokine, Cxcl13, increased 119-fold in dorsal spinal cord, but only 2-fold in the ventral spinal cord of old versus young mice. Therefore, we propose the dorsal spinal cord of old animals is subject to region-specific alterations that prime circuits for the development of pathological pain, potentially in the absence of the peripheral triggers normally associated with these conditions.

Bupleurum chinense Polysaccharide Improves LPS-Induced Senescence of RAW264.7 Cells by Regulating the NF-κB Signaling Pathway.

Macrophages are important inflammatory cells that play a vital role in inflamm-aging. Bupleurum chinense polysaccharide (BCP), an effective component of the Bupleurum chinense herb, exerts multiple beneficial pharmacological effects, such as improving immunity and antioxidant activity. However, the effects of BCP on macrophage-aging and inflamm-aging are yet to be established. In this study, we examined the effects of BCP on proliferation, inflammatory cytokines, β-galactosidase (SA-β-gal), senescence-associated heterochromatin foci (SAHF), reactive oxygen species (ROS), mitochondrial membrane potential, p53, p16, and p65/NF-κB signaling proteins in lipopolysaccharide (LPS)-stimulated RAW264.7 cells. BCP significantly inhibited production of interleukin-1α (IL-1α), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α), reduced the expression of SA-β-gal and formation of SAHF, as well as ROS level, and stabilized the mitochondrial membrane potential in RAW264.7 cells stimulated with LPS. Furthermore, BCP inhibited the expression of aging-related genes, p53 and p16, suppressed phosphorylation of p65 protein, and enhanced the expression of I-κBα protein through the NF-κB signaling pathway in LPS-stimulated RAW264.7 cells. Accordingly, we conclude that BCP effectively suppresses inflamm-aging by reducing inflammatory cytokine levels and oxidative stress production following activation of the NF-κB signaling pathway in RAW264.7 cells stimulated with LPS. Our collective findings support the utility of BCP as a novel pharmaceutical agent with potential anti-inflamm-aging effects.

Antiaging effect of a Jianpi-yangwei formula in Caenorhabditis elegans

BackgroundJianpi-yangwei (JPYW), a traditional Chinese medicine (TCM), helps to nourish the stomach and spleen and is primarily used to treat functional declines related to aging. This study aimed to explore the antiaging effects and mechanism of JPYW by employing a Caenorhabditis elegans model.MethodsWild-type C. elegans N2 worms were cultured in growth medium with or without JPYW, and lifespan analysis, oxidative and heat stress resistance assays, and other aging-related assays were performed. The effects of JPYW on the levels of superoxide dismutase (SOD) and the expression of specific genes were examined to explore the underlying mechanism of JPYW.ResultsCompared to control worms, JPYW-treated wild-type worms showed increased survival times under both normal and stress conditions (P < 0.05). JPYW-treated worms also exhibited enhanced reproduction, movement and growth and decreased intestinal lipofuscin accumulation compared to controls (P < 0.05). Furthermore, increased activity of SOD, downregulated expression levels of the proaging gene clk-2 and upregulated expression levels of the antiaging genes daf-16, skn-1, and sir-2.1 were observed in the JPYW group compared to the control group.ConclusionOur findings suggest that JPYW extends the lifespan of C. elegans and exerts antiaging effects by increasing the activity of an antioxidant enzyme (SOD) and by regulating the expression of aging-related genes. This study not only indicates that this Chinese compound exerts antiaging effects by activating and repressing target genes but also provides a proven methodology for studying the biological mechanisms of TCMs.

Age-Related Gene Expression Signature in Rats Demonstrate Early, Late, and Linear Transcriptional Changes from Multiple Tissues

To understand the changes in gene expression that occur as a result of age, which might create a permissive or causal environment for age-related diseases, we produce a multi-time point age-related gene expression signature (AGES) from liver, kidney, skeletal muscle, and hippocampus of rats, comparing 6-,9-, 12-, 18-, 21-, 24-, and 27-month-old animals. We focus on genes that changed in one direction throughout the lifespan of the animal, either early in life (early logistic changes), at mid-age (mid-logistic), late in life (late-logistic), or linearly, throughout the lifespan of the animal. The pathways perturbed because of chronological age demonstrate organ-specific and more-global effects of aging and point to mechanisms that could potentially be counter-regulated pharmacologically to treat age-associated diseases. A small number of genes are regulated by aging in the same manner in every tissue, suggesting they may be more-universal markers of aging.

Exendin-4 enhances proliferation of senescent osteoblasts through activation of the IGF-1/IGF-1R signaling pathway

A growing body of evidence indicates that treatment with glucagon-like peptide-1 (GLP-1) receptor agonists can be beneficial for patients with osteoporosis. However, the underlying mechanism by which GLP-1 receptor agonists improve osteoporosis remains unclear. In this study, we assessed the anti-osteoporosis effects of Exendin-4, a highly potent GLP-1 receptor agonist, using a rat senescent osteoblast model. We found that Exendin-4 improved proliferation of senescent osteoblasts, as indicated by MTT assay and ALP activity detection. RT-qPCR revealed that Exendin-4 up-regulated the expression of bone metabolism genes (OPG, RANKL, BGP) and down-regulated the expression of aging-related genes (p16, p21, p53). Meanwhile, we observed a sustained increase in IGF-1 receptor (IGF-1R) expression, and not GLP-1 receptor (GLP-1R) expression, in senescent osteoblasts treated with Exendin-4. Furthermore, intervention with Exendin-4 in senescent osteoblasts increased IGF-1, p-PI3K, and p-Akt protein levels, as shown by western blot analysis. Finally, downregulation of IGF-1 by RNAi inhibited the anti-osteoporosis effects of Exendin-4, which is associated with the IGF-1/PI3K/Akt signaling pathway. In summary, these results indicate that the GLP-1 receptor agonist Exendin-4 promotes proliferation of senescent osteoblasts by up-regulating IGF-1R expression and activating the IGF-1/PI3K/Akt signaling pathway, thereby preventing senile osteoporosis.

Long-term effects of maternal choline supplementation on CA1 pyramidal neuron gene expression in the Ts65Dn mouse model of Down syndrome and Alzheimer's disease.

Choline is critical for normative function of 3 major pathways in the brain, including acetylcholine biosynthesis, being a key mediator of epigenetic regulation, and serving as the primary substrate for the phosphatidylethanolamine N-methyltransferase pathway. Sufficient intake of dietary choline is critical for proper brain function and neurodevelopment. This is especially important for brain development during the perinatal period. Current dietary recommendations for choline intake were undertaken without critical evaluation of maternal choline levels. As such, recommended levels may be insufficient for both mother and fetus. Herein, we examined the impact of perinatal maternal choline supplementation (MCS) in a mouse model of Down syndrome and Alzheimer's disease, the Ts65Dn mouse relative to normal disomic littermates, to examine the effects on gene expression within adult offspring at ∼6 and 11 mo of age. We found MCS produces significant changes in offspring gene expression levels that supersede age-related and genotypic gene expression changes. Alterations due to MCS impact every gene ontology category queried, including GABAergic neurotransmission, the endosomal-lysosomal pathway and autophagy, and neurotrophins, highlighting the importance of proper choline intake during the perinatal period, especially when the fetus is known to have a neurodevelopmental disorder such as trisomy.-Alldred, M. J., Chao, H. M., Lee, S. H., Beilin, J., Powers, B. E., Petkova, E., Strupp, B. J., Ginsberg, S. D. Long-term effects of maternal choline supplementation on CA1 pyramidal neuron gene expression in the Ts65Dn mouse model of Down syndrome and Alzheimer's disease.

Longitudinal comparative transcriptomics reveals unique mechanisms underlying extended healthspan in bats.

Bats are the longest-lived mammals, given their body size. However, the underlying molecular mechanisms of their extended healthspans are poorly understood. To address this question we carried out an eight-year longitudinal study of ageing in long-lived bats (Myotis myotis). We deep-sequenced ~1.7 trillion base pairs of RNA from 150 blood samples collected from known aged bats to ascertain the age-related transcriptomic shifts and potential microRNA-directed regulation that occurred. We also compared ageing transcriptomic profiles between bats and other mammals by analysis of 298 longitudinal RNA sequencing datasets. Bats did not show the same transcriptomic changes with age as commonly observed in humans and other mammals, but rather exhibited a unique, age-related gene expression pattern associated with DNA repair, autophagy, immunity and tumour suppression that may drive their extended healthspans. We show that bats have naturally evolved transcriptomic signatures that are known to extend lifespan in model organisms, and identify novel genes not yet implicated in healthy ageing. We further show that bats' longevity profiles are partially regulated by microRNA, thus providing novel regulatory targets and pathways for future ageing intervention studies. These results further disentangle the ageing process by highlighting which ageing pathways contribute most to healthy ageing in mammals.

Comparison of multi-tissue aging between human and mouse

With the rapid growth of the aging population, exploring the biological basis of aging and related molecular mechanisms has become an important topic in modern scientific research. Aging can cause multiple organ function attenuations, leading to the occurrence and development of various age-related metabolic, nervous system, and cardiovascular diseases. In addition, aging is closely related to the occurrence and development of tumors. Although a number of studies have used various mouse models to study aging, further research is needed to associate mouse and human aging at the molecular level. In this paper, we systematically assessed the relationship between human and mouse aging by comparing multi-tissue age-related gene expression sets. We compared 18 human and mouse tissues, and found 9 significantly correlated tissue pairs. Functional analysis also revealed some terms related to aging in human and mouse. And we performed a crosswise comparison of homologous age-related genes with 18 tissues in human and mouse respectively, and found that human Brain_Cortex was significantly correlated with Brain_Hippocampus, which was also found in mouse. In addition, we focused on comparing four brain-related tissues in human and mouse, and found a gene–GFAP–related to aging in both human and mouse.

Age-related gene and miRNA expression changes in airways of healthy individuals

Knowledge on age-related miRNA changes in healthy individuals and their interaction with mRNAs is lacking. We studied age-related mRNA and miRNA expression changes and their interactions in normal airways. RNA and small RNA sequencing was performed on bronchial biopsies of 86 healthy individuals (age: 18–73) to determine age-related expression changes. Per age-related miRNA we determined the enrichment of age-related predicted targets and their correlation. We identified 285 age-related genes and 27 age-related miRNAs. Pathway enrichment showed that genes higher expressed with age were involved in synapse-related processes. Genes lower expressed with age were involved in cell cycle regulation, the immune system and DNA damage/repair. MiR-146a-5p, miR-146b-5p and miR-142-5p were lower expressed with increasing age and we found a significant enrichment for predicted targets of these miRNAs among genes that were higher expressed with age. The expression levels of the enriched predicted targets RIMS2 and IGSF1 were negatively correlated with both miR-146a-5p and miR-146b-5p. RIMS2 was present in the enriched process, i.e. positive regulation of synaptic transmission. In conclusion, genes decreased with ageing are involved in several of the ageing hallmarks. Genes higher expressed with ageing were involved in synapse-related processes, of which RIMS2 is potentially regulated by two age-related miRNAs.

The Neuronal Overexpression of Gclc in Drosophila melanogaster Induces Life Extension With Longevity-Associated Transcriptomic Changes in the Thorax.

Some effects of aging in animals are tissue-specific. In D. melanogaster neuronal overexpression of Gclc increases lifespan and improves certain physiological parameters associated with health benefits such as locomotor activity, circadian rhythmicity, and stress resistance. Our previous transcriptomic analyses of Drosophila heads, primarily composed of neuronal tissue, revealed significant changes in expression levels of genes involved in aging-related signaling pathways (Jak-STAT, MAPK, FOXO, Notch, mTOR, TGF-beta), translation, protein processing in endoplasmic reticulum, proteasomal degradation, glycolysis, oxidative phosphorylation, apoptosis, regulation of circadian rhythms, differentiation of neurons, synaptic plasticity, and transmission. Considering that various tissues age differently and age-related gene expression changes are tissue-specific, we investigated the effects of neuronal Gclc overexpression on gene expression levels in the imago thorax, which is primarily composed of muscles. A total of 58 genes were found to be differentially expressed between thoraces of control and Gclc overexpressing flies. The Gclc level demonstrated associations with expression of genes involved in the circadian rhythmicity, the genes in categories related to the muscle system process and the downregulation of genes involved in proteolysis. Most of the functional categories altered by Gclc overexpression related to metabolism including Drug metabolism, Metabolism of xenobiotics by cytochrome P450, Glutathione metabolism, Starch and sucrose metabolism, Citrate cycle (TCA cycle), One carbon pool by folate. Thus, the transcriptomic changes caused by neuron-specific Gclc overexpression in the thorax were less pronounced than in the head and affected pathways also differed from previous results. Although these pathways don't belong to the canonical longevity pathways, we suggest that they could participate in the delay of aging of Gclc overexpressing flies.

Age-related Gene Expression and Histologic Changes in Human Nasal Polyps

Age-related Gene Expression and Histologic Changes in Human Nasal Polyps

Relationship between senescence in macaques and bone marrow mesenchymal stem cells and the molecular mechanism.

The relationship between bone marrow mesenchymal stem cells (BMSCs) and aging, as well as the antiaging effects of BMSCs, was observed. An aging macaque BMSC model was established. We isolated BMSCs from young and aged macaques and used RT-PCR and Western blot to confirm the aging-related mRNAs and their expression, revealing that TERT, SIRT1 and SIRT6 expression was decreased in the aged BMSCs. The morphology, immunophenotype, differentiation potential, proliferation potential, and antiaging effects of aged and young BMSCs on 293T cells were compared. The expression of aging-related genes and the difference between the secreted cytokines in natural aging and induced aging BMSCs were observed. The transcriptome of peripheral blood mononuclear cells from macaques was analyzed by high-throughput sequencing. Finally, the transcriptional characteristics and regulatory mechanisms of gene transcription in aging macaques were investigated.

The effects of the metformin on inhibition of UVA-induced expression of MMPs and COL-I in human skin fibroblasts

This study was to investigate the effects of metformin (MF) on ultraviolet A (UVA)-induced expression of matrix metalloproteinases (MMPs) and type I collagen (COL-I) in human skin fibroblasts (HSFs). HSFs were cultured in vitro and divided into control group, UVA group, and UVA + MF group. Cell proliferation was detected by CCK-8 method, and intracellular reactive oxygen species (ROS) level was detected by flow cytometry with fluorescent probe 2′,7′-dichlorofluorescein diacetate (DCF-DA) staining. Meanwhile, real-time polymerase chain reaction (PCR) was used to examine the relative messenger RNA (mRNA) expression of aging-related genes, including MMP1, MMP3, and COL-I. Moreover, the expression of MMP1, MMP3, and COL-I proteins was further detected by western blot. Compared with the control group, the ROS content in the UVA group was increased significantly ( P &lt; 0.05), while the ROS content in the UVA + MF group was evidently lower than that in the UVA group ( P &lt; 0.05). In addition, the MMP1 and MMP3 mRNA levels were significantly elevated, while the COL-I mRNA was significantly decreased in UVA-induced HSF cells compared with the control cells. However, MF could significantly inhibit the improved MMP1 and MMP3 mRNA level and increase the COL-I mRNA level. Moreover, MF could significantly reverse the increasing MMP1 and MMP3 protein level and decreasing COL-I protein level induced by UVA. In conclusion, MF can increase the antioxidant capacity of cells and increase the synthesis of COL-I by inhibiting the level of intracellular ROS and the expression of related MMPs, thereby inhibiting the UVA-induced photoaging effect of HSF.

Molecular Alterations in Chronic Myelomonocytic Leukemia Monocytes: Transcriptional and Methylation Profiling

Chronic myelomonocytic leukemia (CMML) is a genetically heterogeneous hematopoietic stem cell disorder that combines features of a myelodysplastic syndrome and a myeloproliferative neoplasm and exhibits a strong bias towards older age. The prognosis of CMML is poor, with overall survival of less than 3 years in most studies, however recurrent somatic mutations explain only 15-24% of the clinical heterogeneity of CMML (Elena C. et al. Blood 128:1408-17, 2016). The extreme skewing of the CMML age distribution suggests that CMML reflects the malignant conversion of the myelomonocytic-biased differentiation characteristic of an aged hematopoietic system. We hypothesized that separating the contribution of the normal aging process from bona fide CMML-specific alterations will improve the molecular characterization and biological understanding of CMML. We decided to focus on monocytes as the phenotypic minimal common denominator of genetically heterogeneous diseases. CD14+ monocytes were sorted from the blood of untreated CMML patients (N=12, median age 77 years, range 61-90), age-matched healthy controls (old controls: N=12, median age 68 years, range 62-74) and young healthy controls (young controls: N=16, median age 29 years, range 24-44) and subjected to RNA sequencing and DNA methylation profiling. Differentially expressed genes in CMML monocytes compared to healthy controls were identified with DESeq2 using a 1% false discovery rate (FDR) and a fold-change cutoff set at >│2│ (Figure 1A). We identified the 2480 CMML-specific genes by subtracting all genes with significant differences in the young controls vs. old controls comparison from the CMML vs. old controls comparison. The top-25 most significantly upregulated genes (Figure 1B) included transcription factors, TNFα signaling genes, genes that regulate genomic stability, and genes involved in apoptosis. The most significantly downregulated transcripts were genes involved in response to DNA damage, RNA binding, monocyte differentiation and mediators of inflammatory process.To link these observations to function, we imputed the 2480 CMML-specific differentially expressed genes into the ingenuity pathway analysis (IPA) application. This analysis uncovered significant enrichment of pathways involved in: mitotic roles of Polo-like kinase, G2/M DNA damage checkpoint regulation, lymphotoxin β receptor signaling, IL-6 signaling and ATM signaling (Figure 1C). DNA methylation profiling revealed 909 differentially methylated regions (DMRs) between CMML and age-matched controls, with most regions being hypermethylated in CMML monocytes. Of these, 37% of the DMRs were intronic, 22% were exonic, 14 % were in the promoter region (Figure 1D), 10% were downstream, 10% were upstream, the remainder were 3‘ and 5‘-overlaps.We also performed integrated analysis using the promoter DMRs and the gene expression profile to identify CMML-associated genes that are likely to be regulated by specific changes in methylation. We observed concomitant changes in CMML-specific mRNA transcripts and DNA methylation promoter regions in the CMML vs. old controls contrast for 10 genes (Figure 1E). AOAH, SERINC5, TAF3 and AHCYL1 were downregulated and hypermethylated; MS4A3, TNF, VCAM1, and IFT80, were upregulated and hypermethylated; TUBA1B was upregulated and hypomethylated and PITPNA was downregulated and hypomethylated.Our study is the first to combine transcriptional and methylation profiling for molecular characterization of CMML monocytes. Conclusions: (i) age-related gene expression changes contribute significantly to the CMML transcriptome; (ii) the CMML-specific transcriptome is characterized by differential regulation of transcription factors, inflammatory response genes and anti-apoptotic pathway genes; (iii) differences in promoter methylation represent only a small proportion of overall differences in methylation, suggesting that intragenic or intronic methylation is a major contributor to the leukemic phenotype; (iv) age-related changes may be necessary, but are not sufficient to realize the CMML phenotype. [Display omitted] DisclosuresDeininger:Pfizer: Consultancy, Membership on an entity's Board of Directors or advisory committees; Blueprint: Consultancy.

Pan-senescence transcriptome analysis identified RRAD as a marker and negative regulator of cellular senescence

Cellular senescence, an irreversible proliferative arrest, functions in tissue remodeling during development and is implicated in multiple aging-associated diseases. While senescent cells often manifest an array of senescence-associated phenotypes, such as cell cycle arrest, altered heterochromatin architecture, reprogrammed metabolism and senescence-associated secretory phenotype (SASP), the identification of senescence cells has been hindered by lack of specific and universal biomarkers. To systematically identify universal biomarkers of cellular senescence, we integrated multiple transcriptome data sets of senescent cells obtained through different in vitro manipulation modes as well as age-related gene expression data of human tissues. Our analysis showed that RRAD (Ras-related associated with diabetes) expression is up-regulated in all the manipulation modes and increases with age in human skin and adipose tissues. The elevated RRAD expression was then confirmed in senescent human fibroblasts that were induced by Ras, H2O2, ionizing radiation, hydroxyurea, etoposide and replicative passage, respectively. Further functional study suggests that RRAD up-regulation acts as a negative feedback mechanism to counter cellular senescence by reducing the level of reactive oxygen species. Finally, we found both p53 and NF-κB bind to RRAD genomic regions and modulate RRAD transcription. This study established RRAD to be a biomarker as well as a novel negative regulator of cellular senescence.

Effect of Angelica polysaccharide on brain senescence of Nestin-GFP mice induced by D-galactose

The incidence of neurodegenerative diseases is severely increasing with the aging. It has been proposed that NSCs (neural stem cells) help to control aging, but the mechanisms responsible remain unclear. Angelica polysaccharide is an active ingredient of Angelica sinensis in traditional Chinese medicine, which possesses versatile pharmacological activities including anti-oxidative and anti-aging effects. In this study, D-gal (D-galactose) was used to construct an aging model of Nestin-GFP transgenic mice brain tissues and NSCs. Mouse model was subcutaneously injected with D-gal, as we observed that mice consistently displayed acceleration of aging-like behavior change, energy metabolism decreased, the expression of aging-related genes was up-regulated. Conversely, aging retardation was achieved in Nestin-GFP mice Induced by D-gal that was locally injected with ASP (Angelica polysaccharide). Mechanistically, we isolated and cultured NSCs in vitro. ASP protected NSCs by increasing the cell proliferation; decreasing the number of SA-β-gal stained neurons; increasing the activity of SOD(superoxide dismutase) and T-AOC(total antioxidant capacity), decreasing the content of MDA(malondialdehyde); decreasing the levels of IL-1b,IL-6,TNF-a and ROS; and down-regulated the expression of cellular senescence associated genes p53, p21 in the aging NSCs. In conclusion, ASP can delay aging speed by protecting NSCs and promote neurogenesis by enhancing the antioxidant and anti-inflammatory capacity, up-regulation of p53/p21 signaling pathway. As to provide theoretical basis for treatment for brain aging related diseases, add new scientific connotation for “qi and blood theory” and “supplement blood and delay aging” of Traditional Chinese Medicine.

Age-related gene expression profiles of immature human oocytes.

What is the difference between the gene expression profiles of single human germinal vesicle (GV) oocytes from women of different ages? There were no statistically significant differences in gene expression profiles of human GV oocytes from women of different ages (range: 25-43). It is well established that reproductive capacity declines as women age, which is attributed to oocyte quality since this decline is counterbalanced in older women receiving young donor oocytes. Altered gene expression of human oocytes at different stages of development in relation to female age is one of the suggested mechanisms that could explain the decrease in oocyte quality. Between 2012 and 2014, 40 human GV oocytes of 40 women were obtained during follicular aspiration as part of routine ICSI treatment. Gene expression profiles of 38 GV oocytes were determined in four different age groups: 25-30, 31-35, 36-38 and 39-43 years of age. GV oocytes were donated for research and frozen between 3.5 and 7.5 h after follicular aspiration. Subsequently, GV oocytes were thawed and prepared for gene expression profile analysis using Agilent microarrays containing ~42 000 Human Gene Expression probe-sets. Gene expression profiles were visualized by hierarchical clustering and the top 500 most differing genes were determined by multidimensional scaling (MDS). Transcripts were analysed in a class comparison between the four age groups and for indicators of biological age: antral follicle count (AFC) and the total dosage of FSH needed for ovarian stimulation. Individual transcripts were analysed using linear regression. A false discovery rate <0.05 was considered statistically significant. Visualization of gene expression profiles of GV oocytes with hierarchal clustering and MDS demonstrated no clear grouping of samples based on female age, AFC or FSH dosage. The gene expression profile of GV oocytes classified in four age groups revealed no significantly differentially expressed genes between the four different age groups. There were also no significantly differentially expressed genes in the linear regression analysis for individual transcripts against age. Not applicable. Immature (GV) oocytes obtained from ovarian stimulation cycles were used. Findings may therefore differ for oocytes at other developmental stages and for in-vivo matured oocytes under physiological conditions. Due to our relatively large, but still limited study sample (40 GV oocytes), we cannot exclude that there might be smaller age-related gene-expression differences, i.e. due to a lack of power. We did not find an effect of female age on gene expression profiles of individual human GV oocytes. Other studies have suggested that gene-expression profiles are affected in mature oocytes, which might imply that female age affects oocyte maturation. Alternatively, other mechanisms in human oocytes might cause the age-related fertility decline. This study received no external funding and there are no competing interests.

Age-related epigenome-wide DNA methylation and hydroxymethylation in longitudinal mouse blood

ABSTRACTDNA methylation at cytosine-phosphate-guanine (CpG) dinucleotides changes as a function of age in humans and animal models, a process that may contribute to chronic disease development. Recent studies have investigated the role of an oxidized form of DNA methylation – 5-hydroxymethylcytosine (5hmC) – in the epigenome, but its contribution to age-related DNA methylation remains unclear. We tested the hypothesis that 5hmC changes with age, but in a direction opposite to 5-methylcytosine (5mC), potentially playing a distinct role in aging. To characterize epigenetic aging, genome-wide 5mC and 5hmC were measured in longitudinal blood samples (2, 4, and 10 months of age) from isogenic mice using two sequencing methods – enhanced reduced representation bisulfite sequencing and hydroxymethylated DNA immunoprecipitation sequencing. Examining the epigenome by age, we identified 28,196 unique differentially methylated CpGs (DMCs) and 8,613 differentially hydroxymethylated regions (DHMRs). Mouse blood showed a general pattern of epigenome-wide hypermethylation and hypo-hydroxymethylation with age. Comparing age-related DMCs and DHMRs, 1,854 annotated genes showed both differential 5mC and 5hmC, including one gene – Nfic – at five CpGs in the same 250 bp chromosomal region. At this region, 5mC and 5hmC levels both decreased with age. Reflecting these age-related epigenetic changes, Nfic RNA expression in blood decreased with age, suggesting that age-related regulation of this gene may be driven by 5hmC, not canonical DNA methylation. Combined, our genome-wide results show age-related differential 5mC and 5hmC, as well as some evidence that changes in 5hmC may drive age-related DNA methylation and gene expression.