Advanced Glycation End Products Increase Salivary Gland Hypofunction in d-Galactose-Induced Aging Rats and Its Prevention by Physical Exercise

A declined salivary gland function is commonly observed in elderly people. Advanced glycation end products (AGEs) are believed to contribute to the pathogenesis of aging. Although physical exercise is shown to increase various organ functions in human and experimental models, it is not known whether it has a similar effect in the salivary glands. In the present study, we evaluated the AGEs burden in the salivary gland in the aging process and the protective effect of physical exercise on age-related salivary hypofunction. To accelerate the aging process, rats were peritoneally injected with D-galactose for 6 weeks. Young control rats and d-galactose-induced aging rats in the old group were not exercised. The rats in the physical exercise group ran on a treadmill (12 m/min, 60 min/day, 3 days/week for 6 weeks). The results showed that the salivary flow rate and total protein levels in the saliva of the d-galactose-induced aging rats were reduced compared to those of the young control rats. Circulating AGEs in serum and secreted AGEs in saliva increased with d-galactose-induced aging. AGEs also accumulated in the salivary glands of these aging rats. The salivary gland of aging rats showed increased reactive oxygen species (ROS) generation, loss of acinar cells, and apoptosis compared to young control mice. However, physical exercise suppressed all of these age-related salivary changes. Overall, physical exercise could provide a beneficial option for age-related salivary hypofunction.

Word Form Retrieval in Spoken Word Production

<p>In the auditory picture-word interference task, participants name pictures whilst ignoring auditory distractor words. Previous studies have reported faster naming latencies when distractors are phonologically related to the target (e.g., tiger-typist) than when they are unrelated. By varying the position of overlap of the shared phonemes and the onset of the distractor, this task may provide valuable insights into the time course of phonological encoding. In the current study, participants named pictures while hearing distractor words that were: begin-related (e.g., letter-lesson); end-related (e.g., letter-otter); or unrelated to the target (e.g., letter-cabin). Distractor onsets varied from -200ms (before target) to +400ms (after target). The study was carried out in two phases: in the first phase, the task was administered to a group of 24 young control participants; in the second phase, it was administered to an individual with aphasia, NP, and a group of six older controls. Phonological facilitation effects of begin-related distractors displayed a fairly consistent pattern across the four distractor onsets for all participant groups. In almost all instances, these effects were significant but were noticeably stronger at early onsets especially around the onset of the target presentation, consistent with previous findings in the literature. Only NP showed strong begin-related facilitation effects at the latest onset. The end-related distractors however, produced somewhat different facilitation effects across the different groups. For the young controls and NP, these effects were stronger and significant at later onsets. The older controls only displayed marginally significant effects at 200ms after the target. Findings from the current study provide support for serial pattern of phoneme retrieval in multisyllabic words, in which a word‟s first syllable becomes available before later syllable(s).</p>

Word Form Retrieval in Spoken Word Production

<p>In the auditory picture-word interference task, participants name pictures whilst ignoring auditory distractor words. Previous studies have reported faster naming latencies when distractors are phonologically related to the target (e.g., tiger-typist) than when they are unrelated. By varying the position of overlap of the shared phonemes and the onset of the distractor, this task may provide valuable insights into the time course of phonological encoding. In the current study, participants named pictures while hearing distractor words that were: begin-related (e.g., letter-lesson); end-related (e.g., letter-otter); or unrelated to the target (e.g., letter-cabin). Distractor onsets varied from -200ms (before target) to +400ms (after target). The study was carried out in two phases: in the first phase, the task was administered to a group of 24 young control participants; in the second phase, it was administered to an individual with aphasia, NP, and a group of six older controls. Phonological facilitation effects of begin-related distractors displayed a fairly consistent pattern across the four distractor onsets for all participant groups. In almost all instances, these effects were significant but were noticeably stronger at early onsets especially around the onset of the target presentation, consistent with previous findings in the literature. Only NP showed strong begin-related facilitation effects at the latest onset. The end-related distractors however, produced somewhat different facilitation effects across the different groups. For the young controls and NP, these effects were stronger and significant at later onsets. The older controls only displayed marginally significant effects at 200ms after the target. Findings from the current study provide support for serial pattern of phoneme retrieval in multisyllabic words, in which a word‟s first syllable becomes available before later syllable(s).</p>

Bone Marrow Mesenchymal Stem Cells Derived From Juvenile Macaques Reversed Ovarian Aging in Elderly Macaques

Background Female sex hormone secretion and reproductive ability decrease with ageing. Bone marrow mesenchymal stem cells (BMMSCs) have been postulated to play a key role in treating ovarian senescence; however, the curative effect and mechanism are not clear. Methods We used the macaque ovarian senescence model and observed the structural and functional effects of juvenile BMMSCs in the treatment of ageing macaque ovaries. Moreover, to elucidate the molecular regulatory mechanism by which BMMSCs reverse ovarian senescence, RNA sequencing (RNA-seq) of the ovaries was used to identify key genes and signalling pathways associated with transcriptome profile changes. Results (1) The Rhesus monkey ovarian aging models were an average of 24 years old and had the following sex hormone levels: 0.28 ± 0.11 mIU/mL hFSH, 0.017 ± 0.009 mIU/mL hLH, 0.24 ± 0.042 ng/mL Testo, 51.86 ± 18.37 pg/mL ESTRDL, 0.13 ± 0.012 ng/mL Prog, 0.013 ± 0.012 hCG, and 11.96 ± 2.96 pmol/l AMH. The ovarian organ index was 0.057 ± 0.021, and the HE staining results showed almost no follicular structure, with only local atresia follicles observed. For young rhesus monkeys, the average age was 7 years old, and sex hormone levels were as follows: 0.043 ± 0.03 mIU/mL hFSH, 0.007 ± 0.009 mIU/mL hLH, 0.57 ± 0.15 ng/mL Testo, 123.2 ± 26.26 pg/mL ESTRDL, 0.28 ± 0.014 ng/mL Prog, 0.05 ± 0.012 hCG and 11.96 ± 2.96 pmol/l AMH. The ovarian organ index was 0.011 ± 0.005, and the HE staining results showed all levels of follicles, suggesting that senile ovaries occur in old macaques. (2) P4 generation BMMSCs presented a typical cell morphology, staining positive for Oil Red O, Alizarin Red, and Alcian Blue. The positive rates of CD29, CD34, CD90, and CD105 on the cell surface were 98, 0.98, 98.8, and 99.8%, respectively, in line with mesenchymal stem cell standards. (3) The PET-CT results showed that the ovarian volume in the elderly treatment group increased, the lesions decreased, and the metabolism was vigorous. (4) The level of sex hormone secretion generally recovered to the level of the follicular phase for the 3rd, 6th and 8th months after the treatment of BMMSCs. (5) The HE results showed that all levels of follicles were observed in the young control group, and the medulla and stroma were neatly arranged, whereas primitive, primary, secondary, and atretic follicles were observed in the elderly treatment group. In addition, the medulla and stroma had obvious boundaries with a small amount of calcium nodules in the young control group. while those in the elderly control group had essentially no follicular structure, with only atretic follicles were seen locally that were filled with connective tissue. Masson staining results showed that the proportion of collagen fibres was 10.61 ± 1.83% in the young control group, 56.79 ± 3.58% in the elderly control group, and 23.71 ± 2.4% in the elderly treatment group. TUNEL staining results showed that cell apoptosis was 1.07 ± 0.04%, in the young control group was, 25.93 + 2.49% in the old control group, and 6.98 + 1.35% in the old treatment group. The immunohistochemistry results showed 114 ± 17, 73 ± 6, and 118 ± 18 blood vessels in the young control group, the elderly control group, and the elderly treatment group, respectively. Immunofluorescence staining showed a lack of expression of enhanced green fluorescence protein (E-GFP) in BMMSCs without from the old control group, while green fluorescence was observed in the old treatment group. (6) After the treatment of BMMSCs, 1258 genes were identified as being differentially expressed. The 3D-PCA trace showed that the ovaries of the macaques in the elderly treatment group shifted to that observed in the young group. The genes that were upregulated with age were downregulated after the stem cell treatment. Genes that are downregulated with age were upregulated after stem cell therapy, and the top 20 PPI network genes were enriched for the progesterone-mediated maturation of follicles, oocytes, and cell cycle categories. Conclusions BMMSCs derived from juvenile macaques can reverse ovarian aging in elderly macaques

Metformin Protects Lens Epithelial Cells Against Senescence in Naturally Aged Model of Mouse

Background: The senescence of lens epithelial cells (LECs) is a major factor of age-related cataract (ARC). ARC results in visual impairment and severe vision loss in elderly. However, the specific mechanism of ARC is not yet clear and there are no effective therapeutic agents to halt the formation of ARC. The current study aimed to further explore the underlying mechanism of formation of ARC and investigate the potential anti-aging effect of metformin (MET) on ARC. Methods: Male C57BL/6 mice were divided into three groups: the young control group (Young, 3 months, n=40), the naturally aged group (Aged, 20months, n=60) and MET group (MET, 20 months, n=60). The young control group (Young, 3 months, n=40) and the naturally aged group (Aged, 20months, n=60) mice received ad libitum standard purified mouse diet and water, while the MET group mice were fed on chows supplied with 0.1% MET for 10 months. The transparency of lens and age-associated proteins P21, P53 were assessed in LECs in three groups. Furthermore, we determined the expressions of AMPK pathway and the effect of MET on AMPK pathway in LECs during the aging process of ARC. Besides, the relationship of autophagy and the senescence of in LECs and the role of MET in the autophagy in in LECs during the aging process of ARC were examined. Results: Our results indicated that age-related inactivation of AMPK pathway and age-related impairment of autophagy might contribute to the senescence of in LECs and occurrence of ARC. Importantly, these results demonstrated that MET effectively alleviated the senescence of in LECs and the formation of ARC probably via inactivation of AMPK pathway and augmentation of autophagy. Conclusion: These findings reveal that MET can be exploited as a potentially useful drug for ARC prevention. Our study will be informative for development of innovative strategies to the clinical treatment of ARC.

Inorganic Nitrite Supplementation Improves Endothelial Function With Aging

To determine the efficacy of inorganic nitrite supplementation on endothelial function in humans and mechanisms of action, we performed (1) a randomized, placebo-controlled, parallel-group clinical trial with sodium nitrite (80 mg/day, 12 weeks) in older adults (N=49, 68±1 year) and (2) reverse-translation experiments in young (6 months) and old (27 months) c57BL/6 mice. In the clinical trial, sodium nitrite increased plasma nitrite ( P <0.05) and was well tolerated. Brachial artery flow-mediated dilation (endothelial function) was increased 28% versus baseline after nitrite supplementation ( P <0.05) but unchanged with placebo. Nitrotyrosine, a marker of oxidative stress, was reduced by 45% versus baseline in biopsied endothelial cells after nitrite, but not placebo, treatment. Plasma from nitrite-treated, but not placebo-treated, subjects decreased whole-cell (CellROX) and mitochondria-specific (MitoSOX) reactive oxygen species in cultured human umbilical vein endothelial cells ( P <0.05). Old mice (old [27 months] control, n=9) had ≈30% lower ex vivo carotid artery endothelium-dependent dilation (EDD) versus young mice (young [6 months] control, n=9) due to reduced NO bioavailability ( P <0.05). Nitrite supplementation (drinking water, 50 mg/L, 8 weeks) restored EDD and NO bioavailability in old mice (n=10) to (6 months) control. Mitochondrial reactive oxygen species suppression of EDD was present in old control (increased EDD with a mitochondrial-targeted antioxidant, P <0.05) but not in young control or old mice supplemented with sodium nitrite. A mitochondrial reactive oxygen species inducer (rotenone) further impaired EDD in old control ( P <0.05); young control and old mice supplemented with sodium nitrite were protected. Markers of mitochondrial health were greater in aorta of old mice supplemented with sodium nitrite versus old control ( P <0.05). Inorganic nitrite supplementation improves endothelial function with aging by increasing NO, decreasing mitochondrial reactive oxygen species/oxidative stress, and increasing mitochondrial stress resistance. REGISTRATION: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT02393742.

Exosomes Derived From Senescent Cells Promote Cellular Senescence

Exosomes are one type of small-cell extracellular vesicles (sEVs), which together with the senescence-associated secretory phenotype (SASP) mainly constitute the senescent microenvironment and perform remotely intercellular communication. However, the effects of senescence on exosomes biosynthesis and secretion and its role in the cell senescence are still obscure. Here, we used human fetal lung diploid fibroblasts (2BS) passaged to PD50 to construct the senescent cells model in vitro, which were confirmed by senescence-related β-galactosidase staining, cell cycle distribution, and intracellular ROS levels. PD30 2BS was used as young control. We evaluated the exosomes derived from senescence and young control group respectively and investigated their regulation of senescence. We found that exosomes released from 2BS had typical sizes and cup-shapes morphology and their surface presented typical exosome-associated proteins. The number of exosomes secreted by senescent cells was significantly higher than that of young cells. Moreover, exosomal markers Alix, TSG101, and CD63 were all more expressed than young cells. Furthermore, we treat young cells with exosomes secreted by senescent cells, which can induce senescence-like changes in young cells, including increased SA-β-Gal activity, up-regulated p16 protein expression, and activation of the Notch signaling pathway. The above results imply that exosomes derived from senescent cells can promote cell senescence. The findings expand the current knowledge on exosomes-mediated aging and provide a novel understanding of the relationship between SASP and senescence. This study is supported by National Natural Science Foundation of China (No. 81771520 and 31702144).

Maintaining and Supporting Seniors’ Wellbeing through Foreign Language Learning: Psycholinguistics of Second Language Acquisition in Older Age

This study concerns aspects of positive psychology connected to foreign language learning (FLL) in an older healthy generation. The positive psychology perspective stresses the positive aspects of improved wellbeing in participants who engage in various activities, particularly mental and brain-training practices. Therefore, the aim of this study was to explore older people’s subjective feelings connected to their FLL as one of the crucial ways to improve their quality of life (QoL). The objective of the research was to determine the subjective satisfaction level of the participants of a second language (L2) acquisition course. The research sample (experimental group) consisted of 105 respondents who were Czech citizens and 55+ years old. Two control groups were set up. The first (young control) consisted of 102 young adults (university students), also Czech citizens, aged between 19 and 23 years. The second control group (elderly control) consisted of 102 subjects older than 55 years, similar in age to the experimental group. A standardized online questionnaire survey was the principal research method, identical both for the experimental and control groups. The findings clearly showed that language training significantly improved the subjective positive feelings and wellbeing of the older participants, regardless of their objective progress in FLL itself. These results stood in opposition to the young control group and were different from the elderly control group. The results revealed that FLL is an effective tool for enhancing the overall wellbeing of older people, which was shown in their expression of their feelings of happiness, satisfaction, and positive motivation to learn an L2. In addition, FLL objectively affected their mental health in a positive way and expanded their social networks. Moreover, FLL was a meaningful activity for them, despite the weak objective learning outcomes due to the decline of cognitive functions, helping them find their general purpose of life, as well as life motivation as expressed in the survey. These findings are crucial, as it has already been proven that wellbeing is directly connected with good health and longevity. Therefore, national governments and all stakeholders dealing with the present issue of the aging population should pay undivided attention to the enhancement of older people’s wellbeing by all possible intervention approaches, including FLL. There is limited research into the issue and the findings of this investigation could be an impetus for further research into the topic from the perspectives of cognitive science, psychology, and psycholinguistics.

Appropriate reference region selection of 18F-florbetaben and 18F-flutemetamol beta-amyloid PET expressed in Centiloid

The Centiloid (CL) is a method for standardizing amyloid beta (Aβ) quantification through different ligands and methods. To find the most appropriate reference region to reduce the variance in the Aβ CL unit between 18F-florbetaben (FBB) and 18F-flutemetamol (FMM), we conducted head-to-head comparisons from 56 participants using the direct comparison of FBB-FMM CL (dcCL) method with four reference regions: cerebellar gray (CG), whole cerebellum (WC), WC with brainstem (WC + B), and pons. The FBB and FMM dcCL units were highly correlated in four reference regions: WC (R2 = 0.97), WC + B (R2 = 0.98), CG (R2 = 0.92), and pons (R2 = 0.98). WC showed the largest effect size in both FBB and FMM. Comparison of the variance of the dcCL values within the young control group showed that with FBB, WC + B had the smallest variance and with FMM, the WC had the smallest variance. Additionally, WC + B showed the smallest absolute difference between FBB and FMM, followed by the WC, pons, and CG. We found that it would be reasonable to use the WC or WC + B as the reference region when converting FBB and FMM SUVRs into dcCL, which can increase the accuracy of standardizing FBB and FMM PET results.

Characterization of Clonal Dynamics after Hematopoietic Cell Transplantation Using Ultra-Sensitive Duplex Sequencing

Hematopoietic cell transplantation (HCT) is used in the treatment of hematologic malignancies (HM). Clonal hematopoiesis of indeterminate potential (CHIP) is the age-associated process whereby healthy individuals accumulate low-frequency clones driven by mutations in genes recurrently mutated in myeloid cancers; CHIP is associated with an increased risk of HM and cardiovascular disease. It has been hypothesized that CHIP clones present in an HCT donor might disproportionately proliferate in the recipient due to a relative growth advantage during immune reconstitution. Here we use Duplex Sequencing (DS) to investigate, years after HCT, whether the clonal makeup of CHIP in prior donors differs from that of the donor-derived hematopoietic system long after allogeneic transfer to a recipient. DS is an ultra-sensitive NGS error-correction technology that relies on sequencing of the individual paired strands of original source DNA molecules to dramatically reduce technical background compared to other NGS methodologies. Here we performed DS on 10 pairs of donor/recipient peripheral blood DNA samples collected 7-46 years post-transplant, as well as DNA from a healthy young control. We used a sequencing panel comprising 29 genes recurrently mutated in acute myeloid leukemia (AML) and generated mean DS molecular depth of 27,580x per sample, with maximum DS depth reaching 45,402x. We detected an average of 356 and 283 total variants per donor and recipient, respectively, and 462 total variants in the control. These included 291 single-count exonic variants (SEV) in the control and an average of 215 SEVs in donors (Fig. A). To enrich for CHIP (clonal) variants, we filtered out single-count (non-clonal) events, as well as intronic (non-splice site) variants and germline SNPs. Whereas the young control had only 5 clonal exonic variants (CEV), meaning nearly all of the variants in the control were SEVs, SNPs or intronic (Fig. A,B), HCT donors and recipients respectively averaged 44 and 38 CEVs. 91% of CEVs were non-synonymous (Fig. B), which is higher than expected by chance. The average age of the donors was 36 years old at the time of HCT (range 12-84), and the oldest donor (M1) had the most CEVs. 24/29 genes in the panel exhibited CEVs in the control or HCT donors (Fig. C). DNMT3A, TET2, BRINP3 (FAM5C) and ASXL1 had the greatest number of CEVs and this imbalance was not explained purely by gene size. The young control sample had an overall somatic mutation frequency (MF) of 4.7x10-7. HCT donors and recipients had average MFs of 1.0x10-6 and 1.7x10-6, respectively. 154 CEVs were shared in at least 1 donor-recipient pair, with the majority present at variant allele frequencies (VAFs) <0.1% (Fig. D). 60 and 71 variants respectively increased or decreased by at least 20% in recipients compared to donors. The average increase was 3.9-fold and the average decrease was 3.1-fold. The greatest fold-increase was 136-fold for DNMT3A W297* in recipient M2 (2.2x10-4 to 3.0x10-2). 9 CEVs increased >10-fold, all in DNMT3A, TET2 and RAD21. Only 1 CEV decreased >10-fold: TP53 R273H (4.9x10-4 to 4.2x10-5). Analysis of the same 10 donor-recipient pairs using a commercial sequencing service found that, with a VAF cutoff of 2% and filtering for SNPs, only 7 shared CEVs could be detected that increased or decreased in any recipient. Our ultra-high accuracy DS data indicates that the structure of CHIP is more polyclonal than has been previously reported. In a handful of older healthy donors we detected dozens of concurrent CHIP mutations, with a relative gene distribution nearly identical to that previously reported in studies on thousands of patients using less sensitive method. We observed a similar age-dependent effect. Furthermore, our findings indicate that the clonal dynamics of CHIP clones between HCT donors and recipients are substantially more complex than previously known. Nearly all somatic variants shared between HCT donors and recipients were observed at <2% VAF, with most <0.1%, which is well-below the detection limit of other NGS assays. Many shared variants increase or decrease in the recipient but, contrary to our expectation, there was not an overall trend for clones carrying likely-drivers (i.e. pathogenic CHIP-associated mutations) to be larger in the recipient than the donor, as compared with probably passengers (i.e. synonymous mutations). This suggests that the evolution of CHIP is not accelerated as a result of HCT. Figure Disclosures Higgins: TwinStrand Biosciences: Employment. Pratt:TwinStrand Biosciences: Employment. Valentine:TwinStrand Biosciences: Employment. Williams:TwinStrand Biosciences: Employment. Radich:Novartis: Other: RNA Sequencing; TwinStrand Biosciences: Research Funding. Salk:TwinStrand Biosciences: Employment.