Biological aging processes underlying cognitive decline and neurodegenerative disease

Tau proteins and senescent Cells: Targeting aging pathways in Alzheimer's disease

Alzheimer's disease (AD) is a devastating neurodegenerative disease characterized by abnormal accumulation of tau proteins and amyloid-β, leading to neuronal death and cognitive impairment. Recent studies have implicated aging pathways, including dysregulation of tau and cellular senescence in AD pathogenesis. In AD brains, tau protein, which normally stabilizes microtubules, becomes hyperphosphorylated and forms insoluble neurofibrillary tangles. These tau aggregates impair neuronal function and are propagated across the brain's neurocircuitry. Meanwhile, the number of senescent cells accumulating in the aging brain is rising, releasing a pro-inflammatory SASP responsible for neuroinflammation and neurodegeneration. This review explores potential therapeutic interventions for AD targeting tau protein and senescent cells, and tau -directed compounds, senolytics, eliminating senescent cells, and agents that modulate the SASP-senomodulators. Ultimately, a combined approach that incorporates tau-directed medications and targeted senescent cell-based therapies holds promise for reducing the harmful impact of AD's shared aging pathways.

Whole-body vibration elicits 40 Hz cortical gamma oscillations and ameliorates age-related cognitive impairment through hippocampal astrocyte synapses in male rats

Age-related cognitive impairment is a prevalent issue in developed societies. Gamma oscil2lations at 40 Hz have been identified as a potential therapeutic approach for age-related cognitive decline and can be induced through various modalities, including auditory, visual, electrical, and magnetic stimulation. In this study, we investigated a novel modality of stimulation: whole-body vibration at 40 Hz. We examined the effects of 40 Hz vibration on cognitive performance and associated neuronal activity in the brains of aged male rats. Our findings revealed that only vibration at 40 Hz, rather than 20 Hz or 80 Hz, elicited cortical gamma oscillations in aged male rats. Additionally, following 8 weeks of prolonged treatment, the implementation of 40 Hz whole-body vibration significantly augmented the cognitive function of aged male rats as evidenced by behavioral assessments. Mechanistic studies demonstrated that these beneficial effects were attributed to the reduction of neuronal apoptosis in hippocampal CA1 through regulation of synaptic connections between astrocytes and neurons via 40 Hz gamma oscillations. Collectively, this suggests a promising intervention for age-related cognitive decline and identifies neuron-astrocyte synapses as potential therapeutic targets.

ZLN005 Reduces Neuroinflammation and Improves Mitochondrial Function in Mice with Perioperative Neurocognitive Disorders

Background

The decrease expression of PGC-1α contributes to perioperative neurocognitive disorders (PND). This study aimed to investigate the effects of the PGC-1α agonist ZLN005 in preventing PND and to explore the potential mechanism.

Methods

C57BL/6 mice were randomly divided into four groups: the control group (Group C), the surgery group (Group S), the surgery and ZLN005 (5 mg/(kg⋅d)) group (Group L), and the surgery and ZLN005 (7.5 mg/(kg⋅d)) group (Group H). Except for Group C, the other three groups received intraperitoneal injections of vehicle or ZLN005 once a day from 3 days before surgery to 3 days after surgery. The open field test, novel object recognition test and fear conditioning test were performed to measure anxiety behaviors, locomotor activity and memory. The levels of IL-6 and IL-1β were measured at 24 hours after surgery. ATP and ROS levels were measured at 3 days post-surgery. PGC-1α, NRF-1, Atp5d, Atp5k and Cox5a were measured at one day or three days post-surgery.

Results

ZLN005 treatment improved the cognitive function of mice in Group L and Group H compared with Group S. The expression of IL-6 and IL-1β in the hippocampus of the S group was increased after surgery, and ZLN005 reduced the expression of IL-6 and IL-1β in the hippocampus of mice one day after surgery. There were parallel decreases in the expression of PGC-1α/NRF-1 and mitochondrial function in the hippocampus of the Group S mice compared with the Group C mice. The expression of PGC-1α/NRF-1 and mitochondrial function were upregulated after ZLN005 treatment.

Conclusion

Neuroinflammation and mitochondrial damage are involved in the occurrence of PND. ZLN005 activates PGC-1α to increase the expression of mitochondrial proteins, improve mitochondrial function, and ultimately ameliorate the cognitive status of mice after surgery.

Association between metabolomics-based biomarker scores and 10-year cognitive decline in men and women. The Doetinchem Cohort Study

BACKGROUND

Metabolomic scores based on age (MetaboAge) and mortality (MetaboHealth) are considered indicators of overall health, but their association with cognition in the general population is unknown. Therefore, the association between MetaboAge/MetaboHealth and level and decline in cognition was studied, as were differences between men and women.

METHODS

Data of 2821 participants (50% women, age range 45-75) from the Doetinchem Cohort Study was used. MetaboAge and MetaboHealth were calculated from 1H-NMR metabolomics data at baseline. Cognitive domain scores (memory, flexibility and processing speed) and global cognitive functioning were available over a 10-year period. The association between MetaboAge/MetaboHealth and level of cognitive functioning was studied using linear regressions while for the association between MetaboAge/MetaboHealth and cognitive decline longitudinal linear mixed models were used. Analyses were adjusted for demographics and lifestyle factors.

RESULTS

Higher MetaboAge, indicating poorer metabolomic ageing, was only associated with lower levels of processing speed in men. Higher MetaboHealth, indicating poorer immune-metabolic health, was associated with lower levels of cognitive functioning for all three domains and global cognitive functioning in both men and women. Only in men, MetaboHealth was also associated with 10-year decline in flexibility, processing speed and global cognition. Metabolites that contributed to the observed associations were in men mainly markers of protein metabolism, and in women mainly markers of lipid metabolism and inflammatory metabolites.

CONCLUSIONS

MetaboHealth, not MetaboAge, was associated with cognitive functioning independent of conventional risk factors. Individual metabolites affect cognitive functioning differently in men and women, suggesting sex-specific pathophysiological pathways underlying cognitive functioning.

Accelerated biological aging: unveiling the path to cardiometabolic multimorbidity, dementia, and mortality

Background

Cardiometabolic multimorbidity (CMM) and aging are increasing public health concerns. This prospective study used UK Biobank cohort to investigate the relationship between biological aging and the trajectory of CMM to dementia and mortality.

Methods

CMM is the coexistence of at least two cardiometabolic diseases (CMD), including stroke, ischemic heart disease, and diabetes. Biological age was calculated using the KDM-BA and PhenoAge algorithms. Accelerated aging indicated biological age advances more rapidly than chronological age.

Results

The study included 415,147 individuals with an average age of 56.5 years. During the average 11-year follow-up period, CMD-free individuals with accelerated aging had a significantly greater risk of CMD (KDM-BA, HR 1.456; PhenoAge, HR 1.404), CMM (KDM-BA, HR 1.952; PhenoAge, HR 1.738), dementia (KDM-BA, HR 1.243; PhenoAge, HR 1.212), and mortality (KDM-BA, HR 1.821; PhenoAge, HR 2.047) in fully-adjusted Cox regression models (p < 0.05 for all). Accelerated aging had adjusted HRs of 1.489 (KDM-BA) and 1.488 (PhenoAge) for CMM, 1.434 (KDM-BA) and 1.514 (PhenoAge) for dementia, and 1.943 (KDM-BA) and 2.239 (PhenoAge) for mortality in participants with CMD at baseline (p < 0.05 for all). CMM significantly mediated accelerated aging's indirect effects on dementia by 13.7% (KDM-BA, HR) and 21.6% (PhenoAge); those on mortality were 4.7% (KDM-BA) and 5.2% (PhenoAge). The population attributable-risk of Life's Essential 8 score (≥80 vs. <80) were 0.79 and 0.43 for KDM-BA and PhenoAge accelerated aging, respectively.

Conclusion

Biological aging involves the entire trajectory of CMM from a CMD-free state to CMD, to CMM, and ultimately to dementia and death. Life's Essential 8 may be a potential target to counter age acceleration.

Complementary value of molecular, phenotypic, and functional aging biomarkers in dementia prediction

DNA methylation age (MA), brain age (BA), and frailty index (FI) are putative aging biomarkers linked to dementia risk. We investigated their relationship and combined potential for prediction of cognitive impairment and future dementia risk using the ADNI database. Of several MA algorithms, DunedinPACE and GrimAge2, associated with memory, were combined in a composite MA alongside BA and a data-driven FI in predictive analyses. Pairwise correlations between age- and sex-adjusted measures for MA (aMA), aBA, and aFI were low. FI outperformed BA and MA in all diagnostic tasks. A model including age, sex, and aFI achieved an area under the curve (AUC) of 0.94 for differentiating cognitively normal controls (CN) from dementia patients in a held-out test set. When combined with clinical biomarkers (apolipoprotein E ε4 allele count, memory, executive function), a model including aBA and aFI predicted 5-year dementia risk among MCI patients with an out-of-sample AUC of 0.88. In the prognostic model, BA and FI offered complementary value (both βs 0.50). The tested MAs did not improve predictions. Results were consistent across FI algorithms, with data-driven health deficit selection yielding the best performance. FI had a stronger adverse effect on prognosis in males, while BA's impact was greater in females. Our findings highlight the complementary value of BA and FI in dementia prediction. The results support a multidimensional view of dementia, including an intertwined relationship between the biomarkers, sex, and prognosis. The tested MA's limited contribution suggests caution in their use for individual risk assessment of dementia.

The role of sirtuin 1 in ageing and neurodegenerative disease: A molecular perspective

Sirtuin 1 (SIRT1), an NAD+-dependent deacetylase, has emerged as a key regulator of cellular processes linked to ageing and neurodegeneration. SIRT1 modulates various signalling pathways, including those involved in autophagy, oxidative stress, and mitochondrial function, which are critical in the pathogenesis of neurodegenerative diseases. This review explores the therapeutic potential of SIRT1 in several neurodegenerative disorders, including Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's disease (HD), and Amyotrophic Lateral Sclerosis (ALS). Preclinical studies have demonstrated that SIRT1 activators, such as resveratrol, SRT1720, and SRT2104, can alleviate disease symptoms by reducing oxidative stress, enhancing autophagic flux, and promoting neuronal survival. Ongoing clinical trials are evaluating the efficacy of these SIRT1 activators, providing hope for future therapeutic strategies targeting SIRT1 in neurodegenerative diseases. This review explores the role of SIRT1 in ageing and neurodegenerative diseases, with a particular focus on its molecular mechanisms, therapeutic potential, and clinical applications.

The Association Between Inflammatory Dietary Pattern and Risk of Cognitive Impairment Among Older Adults with Chronic Diseases and Its Multimorbidity: A Cross-Sectional Study

Background

The present study aimed to explore the association between the inflammatory potential of diet, assessed by energy-adjusted dietary inflammatory index (E-DII) and reduced rank regression (RRR)-derived inflammatory dietary pattern, and the risk for cognitive impairment (CI) in community-dwelling older adults, especially in older adults with chronic diseases and multimorbidity.

Methods

A total of 549 older adults from Taiyuan city were included in the present cross-sectional study. The Chinese Version of the Mini-Mental State Examination (CMMSE) was used for the evaluation of cognitive function. E-DII score was calculated based on semi-quantitative food frequency questionnaire (FFQ). Blood samples, including interleukin (IL)-1β, interleukin (IL)-18, tumor necrosis factor-α (TNF-α) and C-reactive protein (CRP), were tested for calculating RRR-derived inflammatory dietary pattern. Logistic regression was used to assess the association between inflammatory dietary pattern and risk of CI. In addition, patients with diabetes, hypertension, hyperlipidemia and multimorbidity were screened for further analysis among 549 older adults.

Results

In those 549 older adults, adjusting for demographic characteristics and chronic disease status, there was no association between E-DII score tertile (OR T3VST1 : 1.357, 95%CI:0.813~2.265, P trend = 0.267), RRR-derived inflammatory dietary pattern score tertile (OR T3VST1 : 1.092, 95%CI:0.679~ 1.758, P trend = 0.737) and risk of CI. However, in older adults with diabetes and multimorbidity, the score tertile of E-DII and RRR-derived inflammatory dietary pattern were positively correlated with risk of CI in a dose-responsive manner (All P trend < 0.05). There is insufficient evidence to reach similar conclusion in patients with hypertension and hyperlipidemia (All P trend > 0.05).

Conclusion

In the present study, pro-inflammatory diet contributed to the increased risk of CI in older adults with diabetes and multimorbidity. These results supplemented vital evidence for the prevention and treatment of CI in older adults with chronic diseases.

Mediterranean Diet and Lifestyle in Persons with Mild to Moderate Alzheimer's Disease

Due to the continuous aging of the population and consequent increase in dementia, focus on its prevention is of growing importance for public health. Since effective pharmacological treatments are not yet available, other determinants of cognitive decline have become fundamental. Several studies have indicated that the Mediterranean diet (MedDiet) is associated with reduced incident cognitive decline and dementia, but few studies have been conducted in persons already diagnosed with Alzheimer's disease (AD). We age-matched 73 patients with mild-moderate AD with 73 controls (mean age for the whole group = 76.5 ± 6.5; 67.5% women). The cases had a significantly lower adherence to the MedDiet and lower physical activity vs. controls, where only one participant (1.4%) had a high adherence to the MedDiet among cases compared to 5.5% among controls, while 52.5% of the cases had a moderate adherence to the MedDiet vs. 82.2% in controls. In multivariate analysis, only the presence of AD was significantly associated with a lower adherence to the MedDiet vs. controls. Other factors examined (gender, age, physical activity level, multimorbidity, and polypharmacy) were not significantly associated with adherence to the MedDiet. Thus, AD patients had a low adherence to the MedDiet and very low physical activity. Public health strategies aimed at promoting the Mediterranean diet and physical activity for older people should be a priority.

Defining and characterizing neuronal senescence, 'neurescence', as GX arrested cells

Cellular senescence is a cell state characterized by resistance to apoptosis and stable cell cycle arrest. Senescence was first observed in mitotic cells in vitro. Recent evidence from in vivo studies and human tissue indicates that postmitotic cells, including neurons, may also become senescent. The quiescent cell state of neurons and inconsistent descriptions of neuronal senescence across studies, however, have caused confusion in this burgeoning field. We summarize evidence demonstrating that exit from G0 quiescence may protect neurons against apoptosis and predispose them toward senescence. Additionally, we propose the term 'neurescent' for senescent neurons and introduce the cell state, GX, to describe cell cycle arrest achieved by passing through G0 quiescence. Criteria are provided to identify neurescent cells, distinguish them from G0 quiescent neurons, and compare neurescent phenotypes with classic replicative senescence.

Senescent cell transplantation into the skin induces age-related peripheral dysfunction and cognitive decline

Cellular senescence is an established cause of cell and tissue aging. Senescent cells have been shown to increase in multiple organs during aging, including the skin. Here we hypothesized that senescent cells residing in the skin can spread senescence to distant organs, thereby accelerating systemic aging processes. To explore this hypothesis, we initially observed an increase in several markers of senescence in the skin of aging mice. Subsequently, we conducted experiments wherein senescent fibroblasts were transplanted into the dermis of young mice and assessed various age-associated parameters. Our findings reveal that the presence of senescent cells in the dermal layer of young mice leads to increased senescence in both proximal and distal host tissues, alongside increased frailty, and impaired musculoskeletal function. Additionally, there was a significant decline in cognitive function, concomitant with increased expression of senescence-associated markers within the hippocampus brain area. These results support the concept that the accumulation of senescent cells in the skin can exert remote effects on other organs including the brain, potentially explaining links between skin and brain disorders and diseases and, contributing to physical and cognitive decline associated with aging.

The Hidden Dangers of Sedentary Living: Insights into Molecular, Cellular, and Systemic Mechanisms

With the aging of the global population, neurodegenerative diseases are emerging as a major public health issue. The adoption of a less sedentary lifestyle has been shown to have a beneficial effect on cognitive decline, but the molecular mechanisms responsible are less clear. Here we provide a detailed analysis of the complex molecular, cellular, and systemic mechanisms underlying age-related cognitive decline and how lifestyle choices influence these processes. A review of the evidence from animal models, human studies, and postmortem analyses emphasizes the importance of integrating physical exercise with cognitive, multisensory, and motor stimulation as part of a multifaceted approach to mitigating cognitive decline. We highlight the potential of these non-pharmacological interventions to address key aging hallmarks, such as genomic instability, telomere attrition, and neuroinflammation, and underscore the need for comprehensive and personalized strategies to promote cognitive resilience and healthy aging.

Differentiation of Alzheimer's disease from other neurodegenerative disorders using chemiluminescence immunoassays measuring cerebrospinal fluid biomarkers

Introduction

Prior research identified four neurochemical cerebrospinal fluid (CSF) biomarkers, Aβ1-42, Aβ1-40, tTau, and pTau(181), as core diagnostic markers for Alzheimer's disease (AD). Determination of AD biomarkers using immunoassays can support differential diagnosis of AD vs. several neuropsychiatric disorders, which is important because the respective treatment regimens differ. Results of biomarker determination can be classified according to the Amyloid/Tau/Neurodegeneration (ATN) system into profiles. Less is known about the clinical performance of chemiluminescence immunoassays (ChLIA) measuring specific biomarkers in CSF samples from patients suffering from neuropsychiatric impairments with various underlying causes.

Methods

Chemiluminescence immunoassays (ChLIAs, EUROIMMUN) were used to determine Beta-Amyloid (1-40), Beta-Amyloid (1-42), Total-Tau, and pTau(181) concentrations in precharacterized cerebrospinal fluid (CSF) samples from 219 AD patients, 74 patients with mild cognitive impairment (MCI), and 220 disease control (DC) patients.

Results

83.0% of AD patients had ATN profiles consistent with AD, whereas 85.5% of DC patients and 77.0% of MCI patients had profiles inconsistent with AD. AD patients showed significantly lower amyloid ratio Aβ1-42/Aβ1-40 (mean: 0.07) and significantly higher concentrations of tTau (mean: 901.6 pg/ml) and pTau(181) (mean: 129 pg/ml) compared to DC and MCI patients (all p values < 0.0071).

Discussion

The ChLIAs effectively determined specific biomarkers and can support differential diagnostics of AD. Their quality was demonstrated in samples from 513 patients with cognitive impairments, representing a realistic mix of underlying causes for seeking treatment at a memory clinic.

Vascular Impairment, Muscle Atrophy, and Cognitive Decline: Critical Age-Related Conditions

The triad of vascular impairment, muscle atrophy, and cognitive decline represents critical age-related conditions that significantly impact health. Vascular impairment disrupts blood flow, precipitating the muscle mass reduction seen in sarcopenia and the decline in neuronal function characteristic of neurodegeneration. Our limited understanding of the intricate relationships within this triad hinders accurate diagnosis and effective treatment strategies. This review analyzes the interrelated mechanisms that contribute to these conditions, with a specific focus on oxidative stress, chronic inflammation, and impaired nutrient delivery. The aim is to understand the common pathways involved and to suggest comprehensive therapeutic approaches. Vascular dysfunctions hinder the circulation of blood and the transportation of nutrients, resulting in sarcopenia characterized by muscle atrophy and weakness. Vascular dysfunction and sarcopenia have a negative impact on physical function and quality of life. Neurodegenerative diseases exhibit comparable pathophysiological mechanisms that affect cognitive and motor functions. Preventive and therapeutic approaches encompass lifestyle adjustments, addressing oxidative stress, inflammation, and integrated therapies that focus on improving vascular and muscular well-being. Better understanding of these links can refine therapeutic strategies and yield better patient outcomes. This study emphasizes the complex interplay between vascular dysfunction, muscle degeneration, and cognitive decline, highlighting the necessity for multidisciplinary treatment approaches. Advances in this domain promise improved diagnostic accuracy, more effective therapeutic options, and enhanced preventive measures, all contributing to a higher quality of life for the elderly population.

Proteogenomic signature of risk of Alzheimer's disease and related dementia risk in individuals with a history of major depression disorder

The mechanisms linking a history of major depressive disorder (MDD) to an increased risk of Alzheimer's disease and related dementia (ADRD) are not fully understood. Using the UK Biobank available proteomic and genomic data, we evaluated the biological mechanisms linking both conditions. In participants with a history of MDD at baseline (n=3,615), we found that plasma levels of NfL, GFAP, PSG1 were associated with higher risk (HR=1.38; 1.37; 1.34, respectively; all adjusted p-values<0.05), while VGF, GET3, and HPGDS were associated with lower risk of incident ADRD (n=150) (HR=0.73; 0.71; 0.66, respectively; all adjusted p-values<0.05) during a mean follow-up of 13.7 years (SD=2.2). Two-sample Mendelian randomization analysis using cis-pQTLs genetic instruments revealed that a lower protein expression of apolipoprotein E and higher IL-10 receptor subunit B were causally linked to incident ADRD. Finally, we developed a Proteomic Risk Score (PrRSMDD-ADRD), which showed strong discriminative power (C-statistic = 0.84) to identify participants with MDD that developed ADRD upon follow-up. In addition to demonstrating an association between plasma proteins associated with inflammation and future ADRD risk in individuals with MDD, our findings include an element of causality using Mendelian Randomization (MR) and PrRSMDD-ADRD can be useful to identify individuals with the highest risk to develop ADRD in a highly vulnerable population.

Targeting ferroptosis opens new avenues in gliomas

Gliomas are one of the most challenging tumors to treat due to their malignant phenotype, brain parenchymal infiltration, intratumoral heterogeneity, and immunosuppressive microenvironment, resulting in a high recurrence rate and dismal five-year survival rate. The current standard therapies, including maximum tumor resection, chemotherapy with temozolomide, and radiotherapy, have exhibited limited efficacy, which is caused partially by the resistance of tumor cell death. Recent studies have revealed that ferroptosis, a newly defined programmed cell death (PCD), plays a crucial role in the occurrence and progression of gliomas and significantly affects the efficacy of various treatments, representing a promising therapeutic strategy. In this review, we provide a comprehensive overview of the latest progress in ferroptosis, its involvement and regulation in the pathophysiological process of gliomas, various treatment hotspots, the existing obstacles, and future directions worth investigating. Our review sheds light on providing novel insights into manipulating ferroptosis to provide potential targets and strategies of glioma treatment.

Glutamatergic Neurotransmission in Aging and Neurodegenerative Diseases: A Potential Target to Improve Cognitive Impairment in Aging

Aging is characterized by the decline in many of the individual's capabilities. It has been recognized that the brain undergoes structural and functional changes during aging that are occasionally associated with the development of neurodegenerative diseases. In this sense, altered glutamatergic neurotransmission, which involves the release, binding, reuptake, and degradation of glutamate (Glu) in the brain, has been widely studied in physiological and pathophysiological aging. In particular, changes in glutamatergic neurotransmission are exacerbated during neurodegenerative diseases and are associated with cognitive impairment, characterized by difficulties in memory, learning, concentration, and decision-making. Thus, in the present manuscript, we aim to highlight the relevance of glutamatergic neurotransmission during cognitive impairment to develop novel strategies to prevent, ameliorate, or delay cognitive decline. To achieve this goal, we provide a comprehensive review of the changes reported in glutamatergic neurotransmission components, such as Glu transporters and receptors during physiological aging and in the most studied neurodegenerative diseases. Finally, we describe the current therapeutic strategies developed to target glutamatergic neurotransmission.

Pivotal role of AGE-RAGE axis in brain aging with current interventions

Brain aging is characterized by several structural, biochemical and molecular changes which can vary among different individuals and can be influenced by genetic, environmental and lifestyle factors. Accumulation of protein aggregates, altered neurotransmitter composition, low-grade chronic inflammation and prolonged oxidative stress have been shown to contribute to brain tissue damage. Among key metabolic byproducts, advanced glycation end products (AGEs), formed endogenously through non-enzymatic reactions or acquired directly from the diet or other exogenous sources, have been detected to accumulate in brain tissue, exerting detrimental effects on cellular structure and function, contributing to neurodegeneration and cognitive decline. Upon binding to signal transduction receptor RAGE, AGEs can initiate pro-inflammatory pathways, exacerbate oxidative stress and neuroinflammation, thus impairing neuronal function and cognition. AGE-RAGE signaling induces programmed cell death, disrupts the blood-brain barrier and promotes protein aggregation, further compromising brain health. In this review, we investigate the intricate relationship between the AGE-RAGE pathway and brain aging in order to detect affected molecules and potential targets for intervention. Reduction of AGE deposition in brain tissue either through novel pharmacological therapeutics, dietary modifications, and lifestyle changes, shows a great promise in mitigating cognitive decline associated with brain aging.

No causal relationship between serum urate and neurodegenerative diseases: A Mendelian randomization study

OBJECTIVE

Observational studies have shown that increased serum urate is associated with a lower risk of neurodegenerative diseases (NDs), but the causality remains unclear. We employed a two-sample Mendelian randomization (MR) approach to assess the causal relationship between serum urate and four common subtypes of NDs, including Parkinson's disease (PD), Alzheimer's disease (AD), amyotrophic lateral sclerosis (ALS), and multiple sclerosis (MS).

METHODS

Serum urate data came from the CKDGen Consortium. GWAS data for PD, AD, ALS, and MS were obtained from four databases in the primary analysis and then acquired statistics from the FinnGen consortium for replication and meta-analysis. Inverse variance weighted (IVW), weighted median (WM), and MR-Egger regression methods were applied in the MR analyses. Pleiotropic effects, heterogeneity, and leave-one-out analyses were evaluated to validate the results.

RESULTS

There was no evidence for the effect of serum urate on PD (OR: 1.00, 95 % CI: 0.90-1.11, P = 0.97), AD (OR: 1.02, 95 % CI: 1.00-1.04, P = 0.06), ALS (OR: 1.05, 95 % CI: 0.97-1.13, P = 0.22), and MS (OR: 1.01, 95 % CI: 0.89-1.14, P = 0.90) risk when combined with the FinnGen consortium, neither was any evidence of pleiotropy detected between the instrumental variables (IVs).

CONCLUSION

The MR analysis suggested that serum urate may not be causally associated with a risk of PD, AD, ALS, and MS.

The effect of different exercise on physical fitness, cognition, and mental health in healthy older adults

Objective

This study aimed to examine the effects of different exercise programs on physical fitness, cognition, and mental health in healthy older adults.

Methods

A randomized controlled study was performed with 89 healthy older adults. They were separated into four groups: the control (Con; n = 20), physical activity (PA; n = 23), cognitive training (CT; n = 23), and physical activity coupled with cognitive training groups (PA + CT; n = 23). The subjects in PA, CT, and PA + CT groups received exercise programs that lasted 40 min daily, conducted at least three days a week for 20 weeks. The PA group received regular aerobic physical activity interventions, the CT group received cognitive training interventions, and the PA + CT group received physical activity combined with cognitive training interventions. Physical fitness (by chair stand, biceps curl, 2-min step, 8-step up and walk, and sit and reach tests), cognitive function (attention, simple reaction time, and spatial memory), and mental health (anxiety and depression status) were evaluated before and after 20 weeks.

Results

The body composition results reveal no significant effects among the four groups after 20 weeks before and after aerobic exercise interventions (p > 0.05). Compared with Con, the PA, CT, and PA + CT groups significantly improved physical fitness parameters (p < 0.05). The post-hoc analysis demonstrated that the PA and PA + CT groups had higher fitness levels than the CT group. Similarly, a significant difference was observed in the cognitive index among the four groups (p < 0.05). As determined by post-hoc analysis, attention and simple reaction time differed sequentially between the Con, PA, CT, and PA + CT groups. The spatial memory was superior in the PA, CT, and PA + CT groups compared to the Con group (p < 0.05), with the PA + CT group exhibiting the highest level of performance. However, there was no significant difference in the mental health parameters among all the groups (p < 0.05).

Conclusion

A 20-week intervention involving different exercise methods can enhance physical fitness, cognition, and mental health in older adults. These methods include physical activity, cognitive training, and a combination of physical and cognitive training. The combined physical activity and cognitive training interventions yielded more favorable outcomes than individual physical or cognitive training interventions.

Protocatechuic Acid from Euonymus alatus Mitigates Scopolamine-Induced Memory Impairment in Mice

The increasing prevalence of age-related neurodegenerative disorders owing to the aging population worldwide poses substantial challenges. This study investigated the neuroprotective effects of protocatechuic acid (PCA), a compound found in various fruits, vegetables, and grains, using a scopolamine-induced hypomnesia mouse model. Six-week-old male C57BL/6J mice were orally administered PCA at doses of 10 and 100 mg/kg body weight per day for two weeks, along with intraperitoneal injections of scopolamine. Learning and memory abilities were assessed using the passive avoidance, Morris water maze, and Y-maze behavioral assays. Biochemical analyses evaluated the levels of oxidative stress markers, including 8-hydroxydeoxyguanosine (8-OHdG) in the blood and malondialdehyde (MDA) in the brain, as well as phase II antioxidant proteins in the hippocampus. Histological examination was conducted to determine hippocampal integrity. Our results demonstrated that PCA administration at 10 mg/kg body weight per day or higher for two weeks (i) significantly ameliorated scopolamine-induced learning and memory impairments, as evidenced by improved performance in behavioral tasks, (ii) reduced plasma 8-OHdG levels and cerebral MDA levels in a dose-dependent manner, (iii) increased antioxidant protein expressions in the hippocampal tissue, and (iv) mitigated histological damage in the hippocampal region of the brain. These findings suggest that oral administration of PCA provides neuroprotective effects against oxidative stress-induced learning and memory impairments, possibly through upregulating antioxidant machinery. Therefore, PCA may serve as a promising dietary supplement for mitigating cognitive deficits associated with neurodegenerative diseases.

Glycosylation in aging and neurodegenerative diseases

Aging, a complex biological process, involves the progressive decline of physiological functions across various systems, leading to increased susceptibility to neurodegenerative diseases. In society, demographic aging imposes significant economic and social burdens due to these conditions. This review specifically examines the association of protein glycosylation with aging and neurodegenerative diseases. Glycosylation, a critical post-translational modification, influences numerous aspects of protein function that are pivotal in aging and the pathophysiology of diseases such as Alzheimer's disease, Parkinson's disease, and other neurodegenerative conditions. We highlight the alterations in glycosylation patterns observed during aging, their implications in the onset and progression of neurodegenerative diseases, and the potential of glycosylation profiles as biomarkers for early detection, prognosis, and monitoring of these age-associated conditions, and delve into the mechanisms of glycosylation. Furthermore, this review explores their role in regulating protein function and mediating critical biological interactions in these diseases. By examining the changes in glycosylation profiles associated with each part, this review underscores the potential of glycosylation research as a tool to enhance our understanding of aging and its related diseases.

Association between polycyclic aromatic hydrocarbon exposure and cognitive performance in older adults: a cross-sectional study from NHANES 2011-2014

Background: polycyclic aromatic hydrocarbons (PAHs) are classified as neurotoxins, but the relationship between exposure to PAHs and cognition in adults is unclear, and their non-linear and mixed exposure association hasn't been explored. Objective: to evaluate the non-linear and joint association between co-exposure to PAHs and multiple cognitive tests in U.S. older people. Methods: restricted cubic spline (RCS) and Bayesian kernel machine regression (BKMR) were conducted to evaluate the non-linear and mixed exposure association, based on the cross-sectional data from NHANES 2011-2014: 772 participants over 60 years old, 4 cognitive test scores, including the Immediate Recall Test (IRT), Delayed Recall Test (DRT), Animal Fluency Test (AFT), and Digit Symbol Substitution test (DSST), and 5 urinary PAH metabolites. Results: a V-shaped nonlinear relationship was found between 3-hydroxyfluorene (3-FLUO), 2-hydroxyfluorene (2-FLUO), and DRT. Negative trends between mixed PAH exposure and IRT, DRT, and DSST scores were observed. 2-FLUO contributed the most to the negative association of multiple PAHs with IRT and DRT scores and 2-hydroxynaphthalene (2-NAP) played the most important role in the decreasing relationship between mixed PAH exposure and DSST scores. Conclusion: our study suggested that PAH exposure in the U.S. elderly might be related to their poor performances in IRT, DRT and DSST. Further prospective studies are needed to validate the association.

Integrative Analysis of the Age-Related Dysregulated Genes Reveals an Inflammation and Immunity-Associated Regulatory Network in Alzheimer's Disease

Alzheimer's disease (AD) is a neurodegenerative disease with a long incubation period. While extensive research has led to the construction of long non-coding RNA (lncRNA)-associated competing endogenous RNA (ceRNA) regulatory networks, which primarily derived from differential analyses between clinical AD patients and control individuals or mice, there remains a critical knowledge gap pertaining to the dynamic alterations in transcript expression profiles that occur with age, spanning from the pre-symptomatic stage to the onset of AD. In the present study, we examined the transcriptomic changes in AD model mice at three distinct stages: the unaffected (un-) stage, the pre-onset stage, and the late-onset stage, and identified 14, 57, and 99 differentially expressed mRNAs (DEmRs) in AD model mice at 3, 6, and 12 months, respectively. Among these, we pinpointed 16 mRNAs closely associated with inflammation and immunity and excavated their lncRNA-mRNA regulatory network based on a comprehensive analysis. Notably, our preliminary analysis suggested that four lncRNAs (NONMMUT102943, ENSMUST00000160309, NONMMUT083044, and NONMMUT126468), eight miRNAs (miR-34a-5p, miR-22-5p, miR-302a/b-3p, miR-340-5p, miR-376a/b-5p, and miR-487b-5p), and four mRNAs (C1qa, Cd68, Ctss, and Slc11a1) may play pivotal roles in orchestrating immune and inflammatory responses during the early stages of AD. Our study has unveiled age-related AD risk genes, and provided an analytical framework for constructing lncRNA-mRNA networks using time series data and correlation analysis. Most notably, we have successfully constructed a comprehensive regulatory ceRNA network comprising genes intricately linked to inflammatory and immune functions in AD.

Longevity extension in rats via improved redox homeostasis with high carbohydrate diet intervention from weaning to adulthood: a comprehensive multi-omics study

Early dietary patterns potentially influence the health status and lifespan throughout adulthood and the entire lifespan. However, dietary behaviors are difficult for everyone to control during adolescence. It is even more important to study the effects of interventions of early dietary patterns on the lifespan under arbitrary feeding conditions. The research involves observing the survival status and lifespan of rats from weaning to adulthood with three different dietary patterns (a high-carbohydrate diet (HC), a high-protein diet (HP), and a high-fat diet (HF)) under ad libitum feeding conditions. The administration of high-carbohydrate diets leads to a significant extension of both median and maximum survival times (P < 0.05) in Wistar rats. Furthermore, it markedly enhanced the spatial memory capacity, mitigated the occurrence of liver and kidney pathological outcomes in elderly rats, and increased the abundance of gut microbiota improving amino acid metabolism. Additionally, feeding rats a high-carbohydrate diet improved glutathione (GSH) synthesis and recycling and activated the expression and upregulation of the lifespan-related proteins Foxo3a/Sirt3 and the key metabolic enzyme GPX-4. The high-carbohydrate diet from weaning to adulthood may potentially extend the lifespan by enhancing rat systemic glutathione synthesis, recycling, and improving the redox state pathway.

Depressive symptom mediates the association between the number of chronic diseases and cognitive impairment: a multi-center cross-sectional study based on community older adults

Objective

The purpose of this study was to understand the relationship between the multiple chronic conditions (MCC), mental health and cognitive function of older adults in the community, and to propose a hypothesis that depressive symptom mediate the number of chronic diseases and cognitive impairment in older adults.

Method

Participants aged 65 years and older from 35 communities in 14 cities in Guangxi, China were recruited. The residents' depressive symptom (PHQ-9) and cognitive status (AD-8) were evaluated, Chi-square test was used to explore the effects of different socio-demographic characteristics on depressive symptom and cognitive impairment. Pearson correlation analysis and the process model 4 were used to explore the relationship between the number of chronic diseases, depressive symptom and cognitive impairment.

Result

A total of 11,582 older adults were included in our analysis. The rate of MCC reaching 26.53%. Hypertension combined with diabetes accounts for the highest proportion of two chronic diseases (13.2%). Among the combination of three chronic diseases, the highest incidence of coexisting hypertension combined with cervical/lumbar spondylosis, and rheumatoid arthritis (7.1%). In this study, depression symptoms accounted for 12.9% of older adults aged 65 and above, and cognitive impairment accounted for 27.4%. Female, older age, reside in urban areas, lower educational levels, no spouse, live alone, and MCC were risk factors for depressive symptom and cognitive impairment in older adults (P<0.05). Depressive symptom had a mediating effect in the number of chronic diseases and cognitive impairment, and the mediating effect (1.109) accounted for 44.13% of the total effect (0.247).

Conclusion

The mental health of the older adult needs to be taken seriously, and improving depressive symptom can reduce the occurrence of cognitive impairment in older patients with MCC to a certain extent.

Advancing personalized medicine in neurodegenerative diseases: The role of epigenetics and pharmacoepigenomics in pharmacotherapy

About 80 % of brain disorders have a genetic basis. The pathogenesis of most neurodegenerative diseases is associated with a myriad of genetic defects, epigenetic alterations (DNA methylation, histone/chromatin remodeling, miRNA dysregulation), and environmental factors. The emergence of new sequencing technologies and tools to study the epigenome has led to identifying predictive biomarkers for earlier diagnosis, opening up the possibility of prophylactical interventions. As a result, advances in pharmacogenetics and pharmacoepigenomics now allow for personalized treatments based on the profile of each patient and the specific genetic and epigenetic mechanisms involved. This Review highlights the complexity of neurodegenerative diseases and the variability in patient responses to pharmacotherapy, emphasizing the influence of genetic polymorphisms on the pharmacokinetics and pharmacodynamics of drugs used to treat those conditions. We specifically discuss the potential modulatory effect of several genetic polymorphisms associated with an increased risk of developing different neurodegenerative diseases. We explore genetic and genomic technologies and the potential of analyzing individual-specific drug metabolism to predict and influence drug response and associated clinical outcomes. We also provide insights into the mechanism of action of the drugs under investigation and their potential impact on disease-modifying pathways. Finally, the Review underscores the great potential of this field to enhance the effectiveness and safety of drug treatments through personalized medicine.

Gliclazide Ameliorates Neuronal Injury by Attenuating Oxidative Stress in D-gal-Induced Senescent Cells and Aging Mice

Enhancement of oxidative stress and resultant neuronal injury play important roles in initiating cognitive impairment during the aging process. Thus, attenuating oxidative injury is regarded as a profitable therapeutic strategy for age-associated cognitive impairment. Previous studies showed that gliclazide (Gli) had a protective role in neuronal injury from cerebral ischemia/reperfusion (I/R) injury. However, whether Gli has a profitable effect on age-associated cognitive impairment remains largely unclear. The present study showed that Gli held the potential to attenuate neuronal apoptosis in D-gal-induced senescent cells and aging mice. Additionally, Gli could alleviate synaptic injury and cognitive function in D-gal-induced aging mice. Further study showed that Gli could attenuate oxidative stress in D-gal-induced senescent cells and aging mice. The p38 MAPK pathway was predicted as the downstream target of Gli retarding oxidative stress using in silico analysis. Further studies revealed that Gli attenuated D-gal-induced phosphorylation of p38 and facilitated Nrf2 nuclear expression, indicating that the anti-oxidative property of Gli may be associated with the p38 MAPK pathway. The study demonstrates that Gli has a beneficial effect on ameliorating D-gal-induced neuronal injury and cognitive impairment, making this compound a promising agent for the prevention and treatment of age-associated cognitive impairment.

Divorce and physical health: A three-level meta-analysis

Divorce is often considered a major and stressful life transition. Given that divorcees are overrepresented in primary care and there is a association between individuals' physical health and psychological adjustment, potential post-divorce health problems are of concern. Yet, empirical evidence is lacking on the magnitude of the overall physical health risk after divorce, on possible differences across specific pathologies, and on factors that may increase or reduce this risk. The current meta-analysis addresses these issues. We identified 94 studies including u = 248 relevant effect sizes, based on N = 1,384,507 participants. Generally, compared to married individuals, divorcees showed significantly worse self-reported health (OR = 1.20, [1.08-1.33]), experienced more physical symptoms (OR = 1.34, [1.17-1.53]), and had a higher risk for diabetes (OR = 1.18 [1.05-1.33]), joint pathologies (OR = 1.24, [1.14-1.34]), cardiovascular (OR = 1.24, [1.09-1.41]) and cerebrovascular conditions (OR = 1.31, [1.14-1.51]), and sexually transmitted diseases (OR = 2.48, [1.32-4.64]). However, they had no increased risk of hypertension, hypercholesterolemia, cancer and cancer development, disabilities or limitations, or cognitive pathologies. Nor did divorcees significantly differ from married individuals when aggregating all pathologies to measure overall physical health problems (OR = 1.14, [0.85 to 1.54]). Yet, moderation analyses revealed that being female, unemployed, childless, or having a lower education constitutes a higher risk for overall physical health problems after divorce. The same applied to having a heavy alcohol consumption, lack of exercise, and being overweight. Our meta-analysis shows that divorcees are at heightened risk of certain pathologies, with sexually transmitted diseases as a particular post-divorce hazard. These findings call for more awareness among counsellors and physicians on divorcees' health conditions and the characteristics that make divorcees even more vulnerable to health problems.

Novel insights into the activating transcription factor 4 in Alzheimer's disease and associated aging-related diseases: Mechanisms and therapeutic implications

Ageing is inherent to all human beings, most mechanistic explanations of ageing results from the combined effects of various physiological and pathological processes. Additionally, aging pivotally contributes to several chronic diseases. Activating transcription factor 4 (ATF4), a member of the ATF/cAMP response element-binding protein family, has recently emerged as a pivotal player owing to its indispensable role in the pathophysiological processes of Alzheimer's disease and aging-related diseases. Moreover, ATF4 is integral to numerous biological processes. Therefore, this article aims to comprehensively review relevant research on the role of ATF4 in the onset and progression of aging-related diseases, elucidating its potential mechanisms and therapeutic approaches. Our objective is to furnish scientific evidence for the early identification of risk factors in aging-related diseases and pave the way for new research directions for their treatment. By elucidating the signaling pathway network of ATF4 in aging-related diseases, we aspire to gain a profound understanding of the molecular and cellular mechanisms, offering novel strategies for addressing aging and developing related therapeutics.

Epigenetic age acceleration and cognitive performance over time in older adults

INTRODUCTION

This study investigated whether epigenetic age acceleration (AA) is associated with the change in cognitive function and the risk of incident dementia over 9 years, separately in males and females.

METHODS

Six epigenetic AA measures, including GrimAge, were estimated in baseline blood samples from 560 Australians aged ≥70 years (50.7% female). Cognitive assessments included global function, episodic memory, executive function, and psychomotor speed. Composite cognitive scores were also generated. Dementia (Diagnostic and Statistical Manual for Mental Disorders - IV [DSM-IV] criteria) was adjudicated by international experts.

RESULTS

Associations between epigenetic AA and cognitive performance over-time varied by sex. In females only, GrimAA/Grim2AA was associated with worse delayed recall, composite cognition, and composite memory (adjusted-beta ranged from -0.1372 to -0.2034). In males only, GrimAA/Grim2AA was associated with slower processing speed (adjusted-beta, -0.3049) and increased dementia risk (adjusted hazard ratios [HRs], 1.78 and 2.00, respectively).

DISCUSSION

Epigenetic AA is associated with cognitive deterioration in later life but with evidence of sex-specific associations.

Highlights

Epigenetic age acceleration was associated with cognitive deterioration over time.However, these associations differed by sex.In females, accelerated GrimAge appeared to be a better marker of decline in memory.In males, accelerated GrimAge was associated with slower processing speed over time.Association between accelerated GrimAge and dementia risk was found only in males.

Longitudinal relationship between grip strength and cognitive function in a European population older than 50 years: A cross-lagged panel model

OBJECTIVES

The aim of this study was to investigate the dynamic longitudinal relationship between grip strength and cognitive function.

METHODS

6175 participants aged ≥50 years were included in the study using three waves of follow-up data from the Survey of Health, Ageing, and Retirement in Europe in 2015 (T1), 2017 (T2) and 2019 (T3). Cognitive function was assessed using numeracy, verbal fluency, immediate recall, delayed recall and total. The cross-lagged panel model was used for analysis.

RESULTS

There was a correlation between grip strength and cognitive function. Standardized path coefficient from numeracy T1 to grip strength T2 was 0.017 (p = 0.003), and from numeracy T2 to grip strength T3 was 0.014 (p = 0.012). Standardized path coefficient from grip strength T1 to numeracy T2 was 0.096 (p < 0.001), and from grip strength T2 to numeracy T3 was 0.113 (p < 0.001). Other indicators of cognitive function had similar relationships with grip strength.

CONCLUSIONS

The study found a statistically significant longitudinal and bidirectional relationship between grip strength and cognitive function in a sample of people aged ≥50 years from several European countries.

Separating the Effects of Transitions Into and Out of Social Isolation and Loneliness on Cognitive Function in Later Life

OBJECTIVES

This study investigates the effects of social isolation and loneliness on cognitive function, distinguishing between the effects of transitioning into and out of these states.

METHODS

This study analyzed data from 6,663 adults aged 65 or older collected over the course of 7 waves (12 years) of the Korean Longitudinal Study of Aging from 2006 to 2018. A novel asymmetric fixed effects model was utilized to separately estimate the effects of transitions into and out of social isolation or loneliness.

RESULTS

The association of transitions into social isolation due to a lack of informal social contact or loneliness with cognitive function (b = -1.387, p < .001 and b = -0.601, p < .001, respectively) was stronger than the association of transitions out of these states (b = 0.345, p < .05 and b = 0.353, p < .001, respectively). The magnitude of the negative and positive coefficients was statistically different (F-statistic = 45.29, p < .001 and F-statistic = 5.12, p < .05, respectively). In contrast, no such asymmetric effects were observed for social isolation due to a lack of formal activity (F-statistic = 0.06, p = .800).

DISCUSSION

The detrimental effects of transitioning into social isolation due to a lack of informal social contact (but not formal activity) or loneliness on cognitive function outweigh the beneficial effects of transitioning out of these states. Preventing the onset of social disconnection should be prioritized as an intervention to improve the cognitive function of older adults.

Preclinical Evidence and Underlying Mechanisms of Polygonum multiflorum and Its Chemical Constituents Against Cognitive Impairments and Alzheimer's Disease

Objectives

Cognitive impairments, ranging from mild to severe, adversely affect daily functioning, quality of life, and work capacity. Despite significant efforts in the past decade, more than 200 promising drug candidates have failed in clinical trials. Herbal remedies are gaining interest as potential treatments for dementia due to their long history and safety, making them valuable for drug development. This review aimed to examine the mechanisms behind the effect of Polygonum multiflorum on cognitive function.

Methods

This study focused primarily on the effects of Polygonum multiflorum and its chemical constituents on cognitive behavioral outcomes including the Morris water maze, the passive avoidance test, and the Y maze, as well as pathogenic targets of cognitive impairment and Alzheimer's disease (AD) like amyloid deposition, amyloid precursor protein, tau hyperphosphorylation, and cognitive decline. Additionally, a thorough evaluation of the mechanisms behind Polygonum multiflorum's impact on cognitive function was conducted. We reviewed the most recent data from preclinical research done on experimental models, particularly looking at Polygonum multiflorum's effects on cognitive decline and AD.

Results

According to recent research, Poligonum multiflorum and its bioactive components, stilbene, and emodin, influence cognitive behavioral results and regulate the pathological target of cognitive impairment and AD. Their mechanisms of action include reducing oxidative and mitochondrial damage, regulating neuroinflammation, halting apoptosis, and promoting increased neurogenesis and synaptogenesis.

Conclusion

This review serves as a comprehensive compilation of current experiments on AD and other cognitive impairment models related to the therapeutic effects of Polygonum multiflorum. We believe that these findings can serve as a basis for future clinical trials and have potential applications in the treatment of human neurological disorders.

Exploring the neural and behavioral correlates of cognitive telerehabilitation in mild cognitive impairment with three distinct approaches

Background

Currently, the impact of drug therapies on neurodegenerative conditions is limited. Therefore, there is a strong clinical interest in non-pharmacological interventions aimed at preserving functionality, delaying disease progression, reducing disability, and improving quality of life for both patients and their caregivers. This longitudinal multicenter Randomized Controlled Trial (RCT) applies three innovative cognitive telerehabilitation (TR) methods to evaluate their impact on brain functional connectivity reconfigurations and on the overall level of cognitive and everyday functions.

Methods

We will include 110 participants with mild cognitive impairment (MCI). Fifty-five participants will be randomly assigned to the intervention group who will receive cognitive TR via three approaches, namely: (a) Network-based Cognitive Training (NBCT), (b) Home-based Cognitive Rehabilitation (HomeCoRe), or (c) Semantic Memory Rehabilitation Training (SMRT). The control group (n = 55) will receive an unstructured home-based cognitive stimulation. The rehabilitative program will last either 4 (NBTC) or 6 weeks (HomeCoRe and SMRT), and the control condition will be adapted to each TR intervention. The effects of TR will be tested in terms of Δ connectivity change, obtained from high-density electroencephalogram (HD-EEG) or functional magnetic resonance imaging at rest (rs-fMRI), acquired before (T0) and after (T1) the intervention. All participants will undergo a comprehensive neuropsychological assessment at four time-points: baseline (T0), within 2 weeks (T1), and after 6 (T2) and 12 months (T3) from the end of TR.

Discussion

The results of this RCT will identify a potential association between improvement in performance induced by individual cognitive TR approaches and modulation of resting-state brain connectivity. The knowledge gained with this study might foster the development of novel TR approaches underpinned by established neural mechanisms to be validated and implemented in clinical practice.Clinical trial registration: [https://classic.clinicaltrials.gov/ct2/show/NCT06278818], identifier [NCT06278818].

IGF2BP2-Shox2 axis regulates hippocampal-neuronal senescence to alleviate microgravity-induced recognition disturbance

During space travel, microgravity leads to disturbances in cognitive function, while the underlying mechanism is still unclear. Simulated microgravity mice showed neuronal age-like changes in the hippocampus of our study. In the context of microgravity, we discovered m6A modification reshapes in the hippocampal region. When paired with RNA-seq and MeRIP-seq, Shox2 was found to be a powerful regulator in hippocampal neuron that respondes to microgravity. Decreased expression of senescence-associated secretory phenotype factors and improved genes related to synapses led to the restoration of memory function in the hippocampus upon increased expression of Shox2. Moreover, we discovered that IGF2BP2 was required for the m6A modification of the Shox2, and overexpressed IGF2BP2 in the hippocampus protected against both neuronal senescence and learning and memory decline caused by loss of gravity. Accordingly, our research identified the hippocampal IGF2BP2-Shox2 axis as a possible therapeutic approach to maintaining cognitive function during space travel.

Genome-Wide Characterization of Somatic Mutation Patterns in Cloned Dogs Reveals Implications for Neuronal Function, Tumorigenesis, and Aging

Studies on somatic mutations in cloned animals have revealed slight genetic variances between clones and their originals, but have yet to identify the precise effects of these differences within the organism. Somatic mutations contribute to aging and are implicated in tumor development and other age-related diseases. Thus, we compared whole genome sequencing data from an original dog with that of cloned dogs, identifying candidate somatic mutations that were disproportionately located within genes previously implicated in aging. The substitutional signature of cloning-specific somatic mutations mirrored the uniform distribution characteristic of the signature associated with human aging. Further analysis of genes revealed significant enrichment of traits associated with body size as well as the molecular mechanisms underlying neuronal function and tumorigenesis. Overall, the somatic mutations found in cloned dogs may indicate a conserved mechanism driving aging across species and a broad spectrum of pathway alterations.

Polygonati Rhizoma: A review on the extraction, purification, structural characterization, biosynthesis of the main secondary metabolites and anti-aging effects

ETHNOPHARMACOLOGICAL RELEVANCE

Polygonati Rhizome (PR) is a plant that is extensively widespread in the temperate zones of the Northern Hemisphere. It is a member of the Polygonatum family of Asparagaceae. PR exhibits diverse pharmacological effects and finds applications in ethnopharmacology, serving as a potent tonic for more than two millennia. PR's compounds endow it with various pharmacological properties, including anti-aging, antioxidant, anti-fatigue, anti-inflammatory, and sleep-enhancing effects, as well as therapeutic potential for osteoporosis and age-related diseases.

AIM OF THE STUDY

This review seeks to offer a thorough overview of the processing, purification, extraction, structural characterization, and biosynthesis pathways of PR. Furthermore, it delves into the anti-aging mechanism of PR, using organ protection as an entry point.

MATERIALS AND METHODS

Information on PR was obtained from scientific databases (Google Scholar, Web of Science, ScienceDirect, SciFinder, PubMed, CNKI) and books, doctoral theses, and master's dissertations.

RESULTS

In this investigation, 49 polysaccharides were extracted from PR, and the impact of various processing, extraction, and purification techniques on the structure and activity of these polysaccharides was evaluated. Additionally, 163 saponins and 46 flavonoids were identified, and three key biosynthesis pathways of secondary metabolites were outlined. Notably, PR and Polygonat Rhizomai polysaccharides (PRP) exhibit remarkable protective effects against age-induced injuries to the brain, liver, kidney, intestine, heart, and vessels, thereby promoting longevity and ameliorating the aging process.

CONCLUSIONS

PR, a culinary and therapeutic herb, is rich in active components and pharmacological activities. Based on this review, PR plays a meaningful role in lifespan extension and anti-aging, which can be attributed to PRP. Future research should delve deeper into the structural aspects of PRP that underlie its anti-aging effects and explore potential synergistic interactions with other compounds. Moreover, exploring the potential applications of PR in functional foods and pharmaceutical formulations is recommended to advance the development of industries and resources focused on healthy aging.

Normative Data Study of Verbal Fluency and Naming Tests in Elderly People in Costa Rica

OBJECTIVE

To generate normative data for the Verbal Fluency Test (VFT) and the Boston Naming Test (BNT) in the Costa Rican population.

METHOD

The sample consisted of 563 healthy older people (aged 59-90 years). Polynomial multiple regression analyses were run to evaluate the effects of the age, sex, and education variables on VFT and BNT scores.

RESULTS

The results showed a significant linear effect of education on the four-letter VF scores and an effect of sex on the letter P score, with females performing better than males. The explained variance ranged from 20.9% to 28.3%. A linear effect of age and education was also found for the four semantic VF scores, with scores decreasing with increasing age and lower education. The sex variable was significant for all semantic categories, with females performing better than males except in the animal category. The explained variance ranged from 21.7% to 30.9%. In the BNT, a linear effect of education was found, so that the more education, the better the score. In addition, a sex effect was also found, with males having higher scores than females. The predictors of the model explained 9.6% of the variance.

CONCLUSIONS

This is the first study that generates normative data for the VF and BNT in the Costa Rican population over 59 years of age based on demographic variables. The use of these normative data will help clinicians in Costa Rica to better understand language functioning in the elderly, allowing for better classification and diagnosis in the future.

Induced pluripotent stem cells (iPSCs): molecular mechanisms of induction and applications

The induced pluripotent stem cell (iPSC) technology has transformed in vitro research and holds great promise to advance regenerative medicine. iPSCs have the capacity for an almost unlimited expansion, are amenable to genetic engineering, and can be differentiated into most somatic cell types. iPSCs have been widely applied to model human development and diseases, perform drug screening, and develop cell therapies. In this review, we outline key developments in the iPSC field and highlight the immense versatility of the iPSC technology for in vitro modeling and therapeutic applications. We begin by discussing the pivotal discoveries that revealed the potential of a somatic cell nucleus for reprogramming and led to successful generation of iPSCs. We consider the molecular mechanisms and dynamics of somatic cell reprogramming as well as the numerous methods available to induce pluripotency. Subsequently, we discuss various iPSC-based cellular models, from mono-cultures of a single cell type to complex three-dimensional organoids, and how these models can be applied to elucidate the mechanisms of human development and diseases. We use examples of neurological disorders, coronavirus disease 2019 (COVID-19), and cancer to highlight the diversity of disease-specific phenotypes that can be modeled using iPSC-derived cells. We also consider how iPSC-derived cellular models can be used in high-throughput drug screening and drug toxicity studies. Finally, we discuss the process of developing autologous and allogeneic iPSC-based cell therapies and their potential to alleviate human diseases.

Intertwined depressive and cognitive trajectories and the risk of dementia and death in older adults: a competing risk analysis

Background

Depressive symptoms and cognitive impairment often interact, rendering their associations controversial. To date, their joint trajectories and associations with dementia and death remain underexplored.

Aims

To explore the interactions between depressive symptoms and cognitive function, their developmental trajectories and the associations with all-cause dementia, Alzheimer's disease (AD) and all-cause death in older adults.

Methods

Data were from the Health and Retirement Study. Depressive symptoms and cognitive function were measured using the 8-item Centre for Epidemiologic Studies Depression Scale and the Telephone Interview of Cognitive Status, respectively. All-cause dementia and AD were defined by self-reported or proxy-reported physician diagnoses. All-cause death was determined by interviews. The restricted cubic spline, group-based trajectory modelling and subdistribution hazard regression were used.

Results

Significant interactions between depressive symptoms and cognitive function in 2010 in their association with new-onset all-cause dementia and AD from 2010 to 2020 were found, especially in women (p for interaction <0.05). Independent trajectory analysis showed that emerging or high (vs no) depressive trajectories and poor or rapidly decreased cognitive trajectories (vs very good) from 1996 to 2010 were at significantly higher risk of subsequent all-cause dementia, AD and all-cause death. 15 joint trajectories of depressive symptoms and cognitive function from 1996 to 2010 were determined, where rapidly decreased cognitive function was more common in those with no depressive symptoms. Compared with older adults with the trajectory of no depressive symptoms and very good cognitive function, those with the trajectory of no depressive symptoms but rapidly decreased cognitive function were much more likely to develop new-onset all-cause dementia and death, with subdistribution hazard ratios (95% confidence intervals) of 4.47 (2.99 to 6.67) and 1.84 (1.43 to 2.36), especially in women.

Conclusions

To effectively mitigate the risk of dementia and death, it is crucial to acknowledge the importance of preventing cognitive decline in older adults without depressive symptoms, particularly in women.

Protective Mechanism of Polysaccharide ORP-1 Isolated from Oudemansiella raphanipes against Age-Related Cognitive Decline through the Microbiota-Gut-Brain Axis

Age-related cognitive decline is primarily attributed to the progressive weakening of synaptic function and loss of synapses, while age-related gut microbial dysbiosis is known to impair synaptic plasticity and cognitive behavior by metabolic alterations. To improve the health of the elderly, the protective mechanisms of Oudemansiella raphanipes polysaccharide (ORP-1) against age-related cognitive decline are investigated. The results demonstrate that ORP-1 and its gut microbiota-derived metabolites SCFAs restore a healthy gut microbial population to handle age-related gut microbiota dysbiosis mainly by increasing the abundance of beneficial bacteria Dubosiella, Clostridiales, and Prevotellaceae and reducing the abundance of harmful bacteria Desulfovibrio, strengthen intestinal barrier integrity by abolishing age-related alterations of tight junction (TJ) and mucin 2 (MUC2) proteins expression, diminish age-dependent increase in circulating inflammatory factors, ameliorate cognitive decline by reversing memory- and synaptic plasticity-related proteins levels, and restrain hyperactivation of microglia-mediated synapse engulfment and neuroinflammation. These findings expand the understanding of prebiotic-microbiota-host interactions.

Nutrition intake modifies the association between pulmonary function and cognitive performance among elderly Americans from NHANES 2011-2012

PURPOSE

Nutrition intake is one of the modifiable risk factors for cognitive decline. Whether energy and protein intakes alter the association between pulmonary function (PF) and cognition has not been studied.

METHODS

We made use of information from the U.S. National Health and Nutrition Examination Survey (NHANES) 2011-2012. PF measures, including forced expiratory volume in one second (FEV1), forced vital capacity (FVC), and peak expiratory flow (PEF), were calculated, whereas cognitive function was assessed through four tests: the Immediate Recall test (IRT), the Delayed Recall test (DRT), the Animal Fluency test (AFT) and the Digit Symbol Substitution test (DSST). Energy and protein intakes were measured using the 24-h dietary recall method. Weighted generalized linear regression was performed upon adjustment for covariates. Further interaction analyses were conducted to investigate the effect of energy and protein intakes on the association between PF and cognition.

RESULTS

We finally included 803 participants aged ≥ 60 years (54.4% female, weighted value). After adjusting for covariates, multiple measures (including FEV1, FVC, PEF, and composite PF) were all positively associated with better global cognition and the DSST score (P < 0.05). A stronger positive association between the DSST score and FEV1 (P for interaction = 0.001), FVC (P for interaction = 0.004), PEF (P for interaction = 0.003), and composite PF (P for interaction = 0.001) in lower energy intake. Similar results were observed in lower protein intake (all P for interaction < 0.05).

CONCLUSION

Higher PF was independently associated with improved specific components of cognitive function (i.e., the DSST score). The positive association between PF and the DSST score was stronger in individuals with lower energy and protein intakes.

Association of food insecurity with successful aging among older Indians: study based on LASI

PURPOSE

Whether food insecurity (FI), a social determinant of health, is linked with successful aging (SA) in the older generation remains uncertain. This study explored the association of FI with SA among older Indians.

METHODS

Data were collected from the Longitudinal Ageing Study in India (LASI) wave 1 (2017-2018). Older adults (≥ 60 years) who completed both the FI and the SA surveys were selected. FI was indicated by the lack of access to enough food in the past year. SA was determined by five components: (1) low probability of diseases; (2) low probability of disability; (3) high cognitive functionality; (4) low probability of depression; and (5) active social engagement. The association of FI and SA was assessed using multivariable logistic regression adjusted for potential covariates. Subgroup analyses were performed to evaluate interactions with age, sex, alcohol use, smoking, and place of residence.

RESULTS

27,579 participants met the eligibility criteria. Overall prevalence was 7.13% for FI and 19.41% for SA. Following full adjustment, FI was inversely associated with SA (OR 0.56; 95% CI 0.49-0.65) and with each of SA's five components. No significant interactions of FI and SA were observed in subgroup analyses stratified by age, sex, alcohol use, smoking, or place of residence.

CONCLUSIONS

FI was inversely associated with SA among older Indians. These findings need to be validated by future studies which should also explore potential underlying mechanisms, and whether interventions decreasing FI might increase SA.

Circulating biomarkers of inflammaging and Alzheimer's disease to track age-related trajectories of dementia: Can we develop a clinically relevant composite combination?

Alzheimer's disease (AD) is a rapidly growing global concern due to a consistent rise of the prevalence of dementia which is mainly caused by the aging population worldwide. An early diagnosis of AD remains important as interventions are plausibly more effective when started at the earliest stages. Recent developments in clinical research have focused on the use of blood-based biomarkers for improve diagnosis/prognosis of neurodegenerative diseases, particularly AD. Unlike invasive cerebrospinal fluid tests, circulating biomarkers are less invasive and will become increasingly cheaper and simple to use in larger number of patients with mild symptoms or at risk of dementia. In addition to AD-specific markers, there is growing interest in biomarkers of inflammaging/neuro-inflammaging, an age-related chronic low-grade inflammatory condition increasingly recognized as one of the main risk factor for almost all age-related diseases, including AD. Several inflammatory markers have been associated with cognitive performance and AD development and progression. The presence of senescent cells, a key driver of inflammaging, has also been linked to AD pathogenesis, and senolytic therapy is emerging as a potential treatment strategy. Here, we describe blood-based biomarkers clinically relevant for AD diagnosis/prognosis and biomarkers of inflammaging associated with AD. Through a systematic review approach, we propose that a combination of circulating neurodegeneration and inflammatory biomarkers may contribute to improving early diagnosis and prognosis, as well as providing valuable insights into the trajectory of cognitive decline and dementia in the aging population.

Investigating the Neuroprotective and Cognitive-Enhancing Effects of Bacopa monnieri: A Systematic Review Focused on Inflammation, Oxidative Stress, Mitochondrial Dysfunction, and Apoptosis

The aging of the global population has increased the prevalence of neurodegenerative conditions. Bacopa monnieri (BM), an herb with active compounds, such as bacosides A and B, betulinic acid, loliolide, asiatic acid, and quercetin, demonstrates the potential for brain health. Limited research has been conducted on the therapeutic applications of BM in neurodegenerative conditions. This systematic review aims to project BM's beneficial role in brain disorders. BM has anti-apoptotic and antioxidant actions and can repair damaged neurons, stimulate kinase activity, restore synaptic function, improve nerve transmission, and increase neuroprotection. The included twenty-two clinical trials demonstrated that BM can reduce Nuclear Factor-κB phosphorylation, improve emotional function, cognitive functions, anhedonia, hyperactivity, sleep routine, depression, attention deficit, learning problems, memory retention, impulsivity, and psychiatric problems. Moreover, BM can reduce the levels of pro-inflammatory biomarkers and oxidative stress. Here, we highlight that BM provides notable therapeutic benefits and can serve as a complementary approach for the care of patients with neurodegenerative conditions associated with brain disorders. This review adds to the growing interest in natural products and their potential therapeutic applications by improving our understanding of the mechanisms underlying cognitive function and neurodegeneration and informing the development of new therapeutic strategies for neurodegenerative diseases.

Quinoline-sulfonamides as a multi-targeting neurotherapeutic for cognitive decline: in vitro, in silico studies and ADME evaluation of monoamine oxidases and cholinesterases inhibitors

Alzheimer's disease (AD) is a multifactorial irreversible neurological disorder with multiple enzymes involved. In the treatment of AD, multifunctional agents targeting cholinesterase (ChE) and monoamine oxidase (MAO) inhibitors have shown promising results. Herein, a series of novel quinoline-sulfonamides (a1-18) were designed and synthesized as a dual inhibitor of MAOs and ChEs. The in vitro results showed that compounds a5, a12, a11, and a6 exhibited the most potent compounds against specific enzymes. They had IC50 value 0.59 ± 0.04 for MAO-A, 0.47 ± 0.03 for MAO-B, 0.58 ± 0.05 for BChE and 1.10 ± 0.77 for AChE μM respectively. Furthermore, kinetic studies revealed that these compounds are competitive. Molecular docking studies enhanced the understanding of the in silico component, unveiling critical interactions, specifically the hydrogen bonding interaction, π-π, π-alkyl, π-amid and π-sulfur interactions between the ligand and enzymes. These findings suggest that compounds a5, a6, a11, a12, a15, and a18 may be potent multifunctional candidates for AD treatment.

Correlation between sarcopenia index and cognitive function in older adult women: A cross-sectional study using NHANES data

OBJECTIVES

The Sarcopenia Index (SI) has the potential as a biomarker for sarcopenia, which is characterized by muscle loss. There is a clear association between sarcopenia and cognitive impairment. However, the relationship between SI and cognitive impairment is yet to be fully understood.

METHODS

We employed data extracted from the U.S. National Health and Nutrition Examination Survey (NHANES) spanning the years 1999 to 2002. Our study encompassed individuals aged 65 to 80 who possessed accessible information regarding both SI and cognitive evaluations with a GFR ≥ 90. Cognitive function was assessed using the digit symbol substitution test (DSST). SI was calculated by serum creatinine (mg/dL)/cystatin C (mg/L)*100. Employing multivariate modeling, we estimated the connection between SI and cognitive performance. Furthermore, to enhance the reliability of our data analysis, we categorized SI using tertiles and subsequently calculated the P-value for trend.

RESULTS

After adjustment for potential confounders, we found SI was significantly and positively correlated with cognitive function scores both in older female in the American population [β = 0.160, 95 % confidence interval (CI) 0.050 to 0.271, P = 0.00461]. Similarly, when the total cognitive function score was treated as a categorical variable according to tertiles, higher SI was related to better total cognitive function scores in females [odds ratio (OR) = 3.968, 95 % CI 1.863 to 6.073, P = 0.00025] following adjustment for confounders.

CONCLUSIONS

Higher SI was correlated with a lower prevalence of cognitive impairment among older adult women with normal kidney function.

Association of mild and complex multimorbidity with structural brain changes in older adults: A population-based study

INTRODUCTION

We quantified the association of mild (ie, involving one or two body systems) and complex (ie, involving ≥3 systems) multimorbidity with structural brain changes in older adults.

METHODS

We included 390 dementia-free participants aged 60+ from the Swedish National Study on Aging and Care in Kungsholmen who underwent brain magnetic resonance imaging at baseline and after 3 and/or 6 years. Using linear mixed models, we estimated the association between multimorbidity and changes in total brain tissue, ventricular, hippocampal, and white matter hyperintensities volumes.

RESULTS

Compared to non-multimorbid participants, those with complex multimorbidity showed the steepest reduction in total brain (β*time -0.03, 95% CI -0.05, -0.01) and hippocampal (β*time -0.05, 95% CI -0.08, -0.03) volumes, the greatest ventricular enlargement (β*time 0.03, 95% CI 0.01, 0.05), and the fastest white matter hyperintensities accumulation (β*time 0.04, 95% CI 0.01, 0.07).

DISCUSSION

Multimorbidity, particularly when involving multiple body systems, is associated with accelerated structural brain changes, involving both neurodegeneration and vascular pathology.

HIGHLIGHTS

Multimorbidity accelerates structural brain changes in cognitively intact older adults These brain changes encompass both neurodegeneration and cerebrovascular pathology The complexity of multimorbidity is associated with the rate of brain changes' progression.