It has been noticed in recent years that the unfavorable effects of the gut microbiota could exhaust host vigor and life, yet knowledge and theory are just beginning to be established. Increasing documentation suggests that the microbiota–gut–brain axis not only impacts brain cognition and psychiatric symptoms but also precipitates neurodegenerative diseases, such as Alzheimer’s disease (AD), Parkinson’s disease (PD), and multiple sclerosis (MS). How the blood–brain barrier (BBB), a machinery protecting the central nervous system (CNS) from the systemic circulation, allows the risky factors derived from the gut to be translocated into the brain seems paradoxical. For the unique anatomical, histological, and immunological properties underpinning its permeable dynamics, the BBB has been regarded as a biomarker associated with neural pathogenesis. The BBB permeability of mice and rats caused by GM dysbiosis raises the question of how the GM and its metabolites change BBB permeability and causes the brain pathophysiology of neuroinflammation and neurodegeneration (NF&ND) and brain aging, a pivotal multidisciplinary field tightly associated with immune and chronic systemic inflammation. If not all, gut microbiota-induced systemic chronic inflammation (GM-SCI) mainly refers to excessive gut inflammation caused by gut mucosal immunity dysregulation, which is often influenced by dietary components and age, is produced at the interface of the intestinal barrier (IB) or exacerbated after IB disruption, initiates various common chronic diseases along its dispersal routes, and eventually impairs BBB integrity to cause NF&ND and brain aging. To illustrate the immune roles of the BBB in pathophysiology affected by inflammatory or “leaky” IB resulting from GM and their metabolites, we reviewed the selected publications, including the role of the BBB as the immune barrier, systemic chronic inflammation and inflammation influences on BBB permeability, NF&ND, and brain aging. To add depth to the bridging role of systemic chronic inflammation, a plausible mechanism indispensable for BBB corruption was highlighted; namely, BBB maintenance cues are affected by inflammatory cytokines, which may help to understand how GM and its metabolites play a major role in NF&ND and aging.
Oxidative stress-induced DNA damage, the senescence-associated secretory phenotype (SASP), and impaired autophagy all are general features of senescent cells. However, the cross-talk among these events and processes is not fully understood. Here, using NIH3T3 cells exposed to hydrogen peroxide stress, we show that stress-induced DNA damage provokes the SASP largely via cytosolic chromatin fragment (CCF) formation, which activates a cascade comprising cGMP-AMP synthase (cGAS), stimulator of interferon genes protein (STING), NF-κB, and SASP, and that autolysosomal function inhibits this cascade. We found that CCFs accumulate in senescent cells with activated cGAS-STING-NF-κB signaling, promoting SASP and cellular senescence. We also present evidence that the persistent accumulation of CCFs in prematurely senescent cells is partially associated with a defect in DNA-degrading activity in autolysosomes and reduced abundance of activated DNase 2α. Intriguingly, we found that metformin- or rapamycin-induced activation of autophagy significantly lessened the size and levels of CCFs and repressed the activation of the cGAS-STING-NF-κB-SASP cascade and cellular senescence. These effects of autophagy activators indicated that autolysosomal function contributes to CCF clearance and SASP suppression, further supported by the fact that the lysosome inhibitor bafilomycin A1 blocked the role of autophagy-mediated CCF clearance and senescence repression.
Introduction: The aim of this study was to investigate the prevalence and associated factors of sarcopenia defined by different criteria in community-dwelling adults of west China using the baseline data of West-China Health and Aging Trend (WCHAT) study. Methods: Adults aged 50 years or older in communities of Yunnan, Guizhou, Sichuan, and Xinjiang provinces were enrolled in this study. We applied 6 diagnostic criteria (AWGS 2019, AWGS 2014, EWGSOP1, EWGSOP2, IWGS, and FNIH) to define sarcopenia. Muscle mass was measured based on bioimpedance analysis. Handgrip strength and walking speed were recorded, respectively. Different variables like anthropometry measures, lifestyles, chronic disease, and blood test were collected. Results: We included 4,500 participants. The prevalence of sarcopenia was 22.8, 19.3, 57.1, 11.8, 24.1, and 18.1% according to the AWGS 2019, AWGS 2014, EWGSOP 1, EWGSOP 2, IWGS, and FNIH criteria, respectively. We found that serum albumin level was independently associated with sarcopenia using AWGS 2019 and IWGS. And vitamin D level was independently associated with sarcopenia using AWGS 2014, EWGSOP2, and FNIH. While age, depressive status, BMI, hemoglobin, vitamin D, and insulin level were all significantly associated with sarcopenia using AWGS 2014, but all of these factors were not significant using AWGS 2019. Conclusions: Sarcopenia was highly prevalent in west China regardless of the diagnostic criteria. Serum albumin and vitamin D level were mostly associated with sarcopenia defined by different criteria. While most risk factors associated with the AWGS 2014-defined sarcopenia exhibited no consistent pattern with AWGS 2019, the validity of the AWGS 2019 consensus needs to be confirmed in further prospective studies.
Background and purpose: Motoric cognitive risk (MCR) syndrome characterized by subjective cognitive complaints and slow gait has been proposed and validated as a pre-dementia syndrome. The overall and specific ethnic prevalence of MCR and the associated factors are poorly understood in middle-aged to older community-dwelling residents in west China. Methods:The present study included 6091 samples from the prospective cohort study, West China Health and Aging Trend (WCHAT). Multidimensional factors of demography, lifestyle, social support, anthropometrics and body components, and clinical status were investigated and analyzed by univariate and multivariate logistic regression models. Lasso regression and K-fold cross-validation were conducted to construct the most predictive model with fitted factors. Results:The overall prevalence of MCR was 9.74%, and ethnically the prevalence was 14.25% in Tibetan, 11.03% in Yi, 10.72% in Han, 5.18% in Uighur and 4.55% in Qiang, respectively. In the adjusted models, the positively associated risk factors included diabetes mellitus (odds ratio [OR] = 1.51, p = 0.007), osteoarthritis (OR = 1.50, p = 0.002), depression (OR = 1.36, p = 0.005), poor sleep (OR = 1.21, p = 0.045), comorbidity (OR = 1.49, p = 0.001) and falls in the last 12 months (OR = 1.34, p = 0.031). Of note, every 1-unit increase of value in stroke was associated with an approximate 3-fold higher risk of having MCR, whilst in high-density lipoprotein with a 30% lower risk of MCR,respectively.Conclusions: Profiles of MCR from the aspects of ethnicity and the presenium stage need further exploration. It is a promising strategy to apply MCR as a primary prevention tool to prevent dementia. | 1355 MOTORIC COGNITIVE RISK SYNDROME IN MULTIPLE ETHNICS INTRODUC TI ON An estimated 55 million people are currently living with dementia globally [1], with forecasts reaching 78 million by 2030 and 152 million by 2050, 60%-80% of which can be attributed to Alzheimer's disease (AD) [1-3]. The Alzheimer's Disease International estimated that 75% of individuals with dementia are not diagnosed and 90% of them are in undeveloped and underdeveloped regions and countries [1]. Dementia is a disease with multifactorial etiology and heterogeneous clinical presentation and disease trajectory. Also, dementia has a long preclinical phase from several years to decades before the cognitive alterations indicating mild cognitive impairment (MCI) are detectable [3,4]. Motoric cognitive risk (MCR) syndrome was proposed and validated in 2013 by Verghese and colleagues to identify aging individuals at high risk for dementia during the pre-dementia stage [5,6]. Approximately 10% of older persons are affected by MCR worldwide [7]. This syndrome integrates two specific harbingers of dementia, subjective cognitive complaints (SCC) and slow gait speed (SG), in the absence of mobility disability and dementia [5,6]. MCR was found to be more strongly associated with cognitive decline or dementia than either of these two harbingers alone [3,8]. Cognitive fun...
Nitric oxide (NO) is extensively involved in various growth processes and stress responses in plants; however, the regulatory mechanism of NO-modulated cellular sugar metabolism is still largely unknown. Here, we report that NO significantly inhibited monosaccharide catabolism by modulating sugar metabolic enzymes through S-nitrosylation (mainly by oxidizing dihydrolipoamide, a cofactor of pyruvate dehydrogenase). These S-nitrosylation modifications led to a decrease in cellular glycolysis enzymes and ATP synthase activities as well as declines in the content of acetyl coenzyme A, ATP, ADP-glucose and UDP-glucose, which eventually caused polysaccharide-biosynthesis inhibition and monosaccharide accumulation. Plant developmental defects that were caused by high levels of NO included delayed flowering time, retarded root growth and reduced starch granule formation. These phenotypic defects could be mediated by sucrose supplementation, suggesting an essential role of NO-sugar cross-talks in plant growth and development. Our findings suggest that molecular manipulations could be used to improve fruit and vegetable sweetness.
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