scholarly journals Age-related shifts in gut microbiota contribute to cognitive decline in aged rats

Aging ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 7801-7817 ◽  
Author(s):  
Yanli Li ◽  
Li Ning ◽  
Yiru Yin ◽  
Rui Wang ◽  
Zhiyong Zhang ◽  
...  
2021 ◽  
Author(s):  
Yun Zhang ◽  
Song Zhang ◽  
Bolin Li ◽  
Yingchun Luo ◽  
Yongtai Gong ◽  
...  

Abstract Aims Ageing is the most significant contributor to the increasing prevalence of atrial fibrillation (AF). The gut microbiota dysbiosis is involved in age-related diseases. However, whether the aged-associated dysbiosis contributes to age-related AF is still unknown. Direct demonstration that the aged gut microbiota is sufficient to transmit the enhanced AF susceptibility in a young host via microbiota-intestinal barrier-atria axis has not yet been reported. This study aimed to determine whether gut microbiota dysbiosis affects age-related AF. Methods and results Herein, by using a faecal microbiota transplantation (FMT) rat model, we demonstrated that the high AF susceptibility of aged rats could be transmitted to a young host. Specially, we found the dramatically increased levels of circulating lipopolysaccharide (LPS) and glucose led to the up-regulated expression of NOD-like receptor protein (NLRP)-3 inflammasome, promoting the development of AF, which depended on the enhanced atrial fibrosis in recipient host. Inhibition of inflammasome by a potent and selective inhibitor of the NLRP3 inflammasome, MCC950, resulted in a lower atrial fibrosis and AF susceptibility. Then, we conducted cross-sectional clinical studies to explore the effect of ageing on the altering trends with glucose levels and circulating LPS among clinical individuals in two China hospitals. We found that both of serum LPS and glucose levels were progressively increased in elderly patients as compared with those young. Furthermore, the ageing phenotype of circulating LPS and glucose levels, intestinal structure and atrial NLRP3-inflammasome of rats were also confirmed in clinical AF patients. Finally, aged rats colonized with youthful microbiota restored intestinal structure and atrial NLRP3-inflammasome activity, which suppressed the development of aged-related AF. Conclusions Collectively, these studies described a novel causal role of aberrant gut microbiota in the pathogenesis of age-related AF, which indicates that the microbiota-intestinal barrier-atrial NLRP3 inflammasome axis may be a rational molecular target for the treatment of aged-related arrhythmia disease.


Author(s):  
Yvonne Rogalski ◽  
Muriel Quintana

The population of older adults is rapidly increasing, as is the number and type of products and interventions proposed to prevent or reduce the risk of age-related cognitive decline. Advocacy and prevention are part of the American Speech-Language-Hearing Association’s (ASHA’s) scope of practice documents, and speech-language pathologists must have basic awareness of the evidence contributing to healthy cognitive aging. In this article, we provide a brief overview outlining the evidence on activity engagement and its effects on cognition in older adults. We explore the current evidence around the activities of eating and drinking with a discussion on the potential benefits of omega-3 fatty acids, polyphenols, alcohol, and coffee. We investigate the evidence on the hypothesized neuroprotective effects of social activity, the evidence on computerized cognitive training, and the emerging behavioral and neuroimaging evidence on physical activity. We conclude that actively aging using a combination of several strategies may be our best line of defense against cognitive decline.


Processes ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 801
Author(s):  
Jehun Choi ◽  
Gwi-Yeong Jang ◽  
Jeonghoon Lee ◽  
Hae-Young Chung ◽  
Hyung-Jun Noh ◽  
...  

Senescence is the phenomenon by which physiological functions of organisms degenerate with time. Cellular senescence is marked by an inhibition of cell cycle progression. Beta-galactosidase accumulates in the lysosomes of aged cells. In this study, human dermal fibroblast cells (HDFs) were treated with 0.5 μM doxorubicin for 4 h to induce cellular senescence. Senescence-associated beta-galactosidase (SA-β-gal) activity was then measured 72 h after treatment with aerial parts of Dendranthema zawadskii var. lucidum (Nakai) J.H. Park (DZ) extract. Treatment with DZ extract significantly decreased SA-β-gal activity in a dose-dependent manner in HDFs. Additionally, DZ extract treatment reduced age-related oxidative stress and inflammation in the aortas of aged rats. The reactive oxygen species (ROS) levels in aortas of aged control rats were higher than those in young rats. However, DZ extract-fed aged rats showed significantly lower ROS levels than the aged control rats. When the aged rats were treated with DZ extract at either 0.2 or 1.0 mg∙kg−1∙day−1, NF-κB levels in aorta tissue decreased significantly compared to those in aorta tissue of the aged control rats without DZ treatment. In addition, DZ extract-fed aged rat aortas showed significant reductions in expression of iNOS and COX-2 induced by NF-κB translocation. Therefore, these results suggest that DZ effectively inhibited senescence-related NF-κB activation and inflammation. DZ extract may have a role in the prevention of the vascular inflammatory responses that occur during vascular aging.


2021 ◽  
Vol 67 ◽  
pp. 101302
Author(s):  
Benjamin Kioussis ◽  
Camilla S.L. Tuttle ◽  
Daniel S. Heard ◽  
Brian K. Kennedy ◽  
Nicola T. Lautenschlager ◽  
...  

Cells ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1611
Author(s):  
Nur Fathiah Abdul Abdul Sani ◽  
Ahmad Imran Zaydi Amir Amir Hamzah ◽  
Zulzikry Hafiz Abu Abu Bakar ◽  
Yasmin Anum Mohd Mohd Yusof ◽  
Suzana Makpol ◽  
...  

The mechanism of cognitive aging at the molecular level is complex and not well understood. Growing evidence suggests that cognitive differences might also be caused by ethnicity. Thus, this study aims to determine the gene expression changes associated with age-related cognitive decline among Malay adults in Malaysia. A cross-sectional study was conducted on 160 healthy Malay subjects, aged between 28 and 79, and recruited around Selangor and Klang Valley, Malaysia. Gene expression analysis was performed using a HumanHT-12v4.0 Expression BeadChip microarray kit. The top 20 differentially expressed genes at p < 0.05 and fold change (FC) = 1.2 showed that PAFAH1B3, HIST1H1E, KCNA3, TM7SF2, RGS1, and TGFBRAP1 were regulated with increased age. The gene set analysis suggests that the Malay adult’s susceptibility to developing age-related cognitive decline might be due to the changes in gene expression patterns associated with inflammation, signal transduction, and metabolic pathway in the genetic network. It may, perhaps, have important implications for finding a biomarker for cognitive decline and offer molecular targets to achieve successful aging, mainly in the Malay population in Malaysia.


2021 ◽  
Vol 7 (21) ◽  
pp. eabe4601
Author(s):  
Sandro Da Mesquita ◽  
Jasmin Herz ◽  
Morgan Wall ◽  
Taitea Dykstra ◽  
Kalil Alves de Lima ◽  
...  

Aging leads to a progressive deterioration of meningeal lymphatics and peripheral immunity, which may accelerate cognitive decline. We hypothesized that an age-related reduction in C-C chemokine receptor type 7 (CCR7)–dependent egress of immune cells through the lymphatic vasculature mediates some aspects of brain aging and potentially exacerbates cognitive decline and Alzheimer’s disease–like brain β-amyloid (Aβ) pathology. We report a reduction in CCR7 expression by meningeal T cells in old mice that is linked to increased effector and regulatory T cells. Hematopoietic CCR7 deficiency mimicked the aging-associated changes in meningeal T cells and led to reduced glymphatic influx and cognitive impairment. Deletion of CCR7 in 5xFAD transgenic mice resulted in deleterious neurovascular and microglial activation, along with increased Aβ deposition in the brain. Treating old mice with anti-CD25 antibodies alleviated the exacerbated meningeal regulatory T cell response and improved cognitive function, highlighting the therapeutic potential of modulating meningeal immunity to fine-tune brain function in aging and in neurodegenerative diseases.


BMJ Open ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. e046879
Author(s):  
Bernhard Grässler ◽  
Fabian Herold ◽  
Milos Dordevic ◽  
Tariq Ali Gujar ◽  
Sabine Darius ◽  
...  

IntroductionThe diagnosis of mild cognitive impairment (MCI), that is, the transitory phase between normal age-related cognitive decline and dementia, remains a challenging task. It was observed that a multimodal approach (simultaneous analysis of several complementary modalities) can improve the classification accuracy. We will combine three noninvasive measurement modalities: functional near-infrared spectroscopy (fNIRS), electroencephalography and heart rate variability via ECG. Our aim is to explore neurophysiological correlates of cognitive performance and whether our multimodal approach can aid in early identification of individuals with MCI.Methods and analysisThis study will be a cross-sectional with patients with MCI and healthy controls (HC). The neurophysiological signals will be measured during rest and while performing cognitive tasks: (1) Stroop, (2) N-back and (3) verbal fluency test (VFT). Main aims of statistical analysis are to (1) determine the differences in neurophysiological responses of HC and MCI, (2) investigate relationships between measures of cognitive performance and neurophysiological responses and (3) investigate whether the classification accuracy can be improved by using our multimodal approach. To meet these targets, statistical analysis will include machine learning approaches.This is, to the best of our knowledge, the first study that applies simultaneously these three modalities in MCI and HC. We hypothesise that the multimodal approach improves the classification accuracy between HC and MCI as compared with a unimodal approach. If our hypothesis is verified, this study paves the way for additional research on multimodal approaches for dementia research and fosters the exploration of new biomarkers for an early detection of nonphysiological age-related cognitive decline.Ethics and disseminationEthics approval was obtained from the local Ethics Committee (reference: 83/19). Data will be shared with the scientific community no more than 1 year following completion of study and data assembly.Trial registration numberClinicalTrials.gov, NCT04427436, registered on 10 June 2020, https://clinicaltrials.gov/ct2/show/study/NCT04427436.


2011 ◽  
Vol 43 (1) ◽  
pp. 201-212 ◽  
Author(s):  
Heather D. VanGuilder ◽  
Julie A. Farley ◽  
Han Yan ◽  
Colleen A. Van Kirk ◽  
Matthew Mitschelen ◽  
...  

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