Restoring metabolism of myeloid cells reverses cognitive decline in ageing

Ensheathing glia promote increased lifespan and healthy brain aging

Glia have an emergent role in brain aging and disease. In the Drosophila melanogaster brain, ensheathing glia function as phagocytic cells and respond to acute neuronal damage, analogous to mammalian microglia. We previously reported changes in glia composition over the life of ants and fruit flies, including a decline in the relative proportion of ensheathing glia with time. How these changes influence brain health and life expectancy is unknown. Here, we show that ensheathing glia but not astrocytes decrease in number during Drosophila melanogaster brain aging. The remaining ensheathing glia display dysregulated expression of genes involved in lipid metabolism and apoptosis, which may lead to lipid droplet accumulation, cellular dysfunction, and death. Inhibition of apoptosis rescued the decline of ensheathing glia with age, improved the neuromotor performance of aged flies, and extended lifespan. Furthermore, an expanded ensheathing glia population prevented amyloid-beta accumulation in a fly model of Alzheimer's disease and delayed the premature death of the diseased animals. These findings suggest that ensheathing glia play a vital role in regulating brain health and animal longevity.

EP2 inhibition restores myeloid metabolism and reverses cognitive decline

Nonsteroidal anti-inflammatory drugs alleviate pain and inflammation by inhibiting the cyclooxygenase pathway. This pathway has various downstream effects, some of which are beneficial. Prostaglandin E2 is a key downstream product in the cyclooxygenase pathway that modulates inflammation. A correlation between aging and increased expression of the prostaglandin E2 receptor, EP2, has been associated with inflammatory processes, cognitive aging, angiogenesis, and tumorigenesis. Therefore, inhibition of EP2 could lead to therapeutic effects and be more selective than inhibiting cyclooxygenase-2. Studies suggest that inhibition of EP2 restores age-associated spatial memory deficits and synaptic proteins and impairs tumorigenesis. The data indicate that EP2 signaling is important in myeloid cell metabolism and support its candidacy as a therapeutic target.

Systems Immunology Approaches to Metabolism

Over the last decade, immunometabolism has emerged as a novel interdisciplinary field of research and yielded significant fundamental insights into the regulation of immune responses. Multiple classical approaches to interrogate immunometabolism, including bulk metabolic profiling and analysis of metabolic regulator expression, paved the way to appreciating the physiological complexity of immunometabolic regulation in vivo. Studying immunometabolism at the systems level raised the need to transition towards the next-generation technology for metabolic profiling and analysis. Spatially resolved metabolic imaging and computational algorithms for multi-modal data integration are new approaches to connecting metabolism and immunity. In this review, we discuss recent studies that highlight the complex physiological interplay between immune responses and metabolism and give an overview of technological developments that bear the promise of capturing this complexity most directly and comprehensively.

Aging microglia

Microglia are the tissue-resident macrophage population of the brain, specialized in supporting the CNS environment and protecting it from endogenous and exogenous insults. Nonetheless, their function declines with age, in ways that remain to be fully elucidated. Given the critical role played by microglia in neurodegenerative diseases, a better understanding of the aging microglia phenotype is an essential prerequisite in designing better preventive and therapeutic strategies. In this review, we discuss the most recent literature on microglia in aging, comparing findings in rodent models and human subjects.

Transforming the understanding of brain immunity

Contemporary studies have completely changed the view of brain immunity from envisioning the brain as isolated and inaccessible to peripheral immune cells to an organ in close physical and functional communication with the immune system for its maintenance, function, and repair. Circulating immune cells reside in special niches in the brain's borders, the choroid plexus, meninges, and perivascular spaces, from which they patrol and sense the brain in a remote manner. These niches, together with the meningeal lymphatic system and skull microchannels, provide multiple routes of interaction between the brain and the immune system, in addition to the blood vasculature. In this Review, we describe current ideas about brain immunity and their implications for brain aging, diseases, and immune-based therapeutic approaches.

Presence of coronary aneurysms during Kawasaki Disease (KD) correlates with lower levels of autoantibodies to both full form and spliced variant of immune regulator Del-1

Kawasaki disease (KD), a rare multisystem inflammatory condition that predominantly affects children under six years of age, is the leading cause of childhood-acquired heart disease in developed countries. The pathogenesis is unknown, but studies support that an infectious stimulus triggers an autoimmune reaction in a genetically susceptible child. Recent studies demonstrated an association with autoantibody response to Del-1 (also known as EDIL3) in children with KD. Del-1 is an extracellular matrix protein that is expressed both in macrophages and vascular endothelium. Del-1 has an anti-inflammatory role by preventing leucocyte migration to inflammatory sites. Del-1 has two expression variants and genetic variants of Del-1 have been associated with the risk of intracranial aneurysms. Due to the physiologic plausibility for a role during KD, we chose to assess if autoantibodies against DEL-1 are seen in a larger cohort of children with KD and to assess if responses correlated to aneurysm formation. Contrary to prior findings, in comparison to febrile controls, autoantibodies were not overall higher in children with KD. Elevation in Post-IVIG samples in comparison to pre-IVIG and convalescent samples supports the commonality of anti-Del-1 antibodies. Autoantibodies were notably lower in children with KD who had coronary Z score elevations in comparison to those who did not.

Regulation of the Blood-Brain Barrier in Health and Disease

The neurovascular unit is a dynamic microenvironment with tightly controlled signaling and transport coordinated by the blood-brain barrier (BBB). A properly functioning BBB allows sufficient movement of ions and macromolecules to meet the high metabolic demand of the central nervous system (CNS), while protecting the brain from pathogenic and noxious insults. This review describes the main cell types comprising the BBB and unique molecular signatures of these cells. Additionally, major signaling pathways for BBB development and maintenance are highlighted. Finally, we describe the pathophysiology of BBB diseases, their relationship to barrier dysfunction, and identify avenues for therapeutic intervention.

Turning Back the Clock: A Retrospective Single-Blind Study on Brain Age Change in Response to Nutraceuticals Supplementation vs. Lifestyle Modifications

BACKGROUND

There is a growing consensus that chronological age (CA) is not an accurate indicator of the aging process and that biological age (BA) instead is a better measure of an individual's risk of age-related outcomes and a more accurate predictor of mortality than actual CA. In this context, BA measures the "true" age, which is an integrated result of an individual's level of damage accumulation across all levels of biological organization, along with preserved resources. The BA is plastic and depends upon epigenetics. Brain state is an important factor contributing to health- and lifespan.

METHODS AND OBJECTIVE

Quantitative electroencephalography (qEEG)-derived brain BA (BBA) is a suitable and promising measure of brain aging. In the present study, we aimed to show that BBA can be decelerated or even reversed in humans (N = 89) by using customized programs of nutraceutical compounds or lifestyle changes (mean duration = 13 months).

RESULTS

We observed that BBA was younger than CA in both groups at the end of the intervention. Furthermore, the BBA of the participants in the nutraceuticals group was 2.83 years younger at the endpoint of the intervention compared with their BBA score at the beginning of the intervention, while the BBA of the participants in the lifestyle group was only 0.02 years younger at the end of the intervention. These results were accompanied by improvements in mental-physical health comorbidities in both groups. The pre-intervention BBA score and the sex of the participants were considered confounding factors and analyzed separately.

CONCLUSIONS

Overall, the obtained results support the feasibility of the goal of this study and also provide the first robust evidence that halting and reversal of brain aging are possible in humans within a reasonable (practical) timeframe of approximately one year.

UGRP1-modulated MARCO+ alveolar macrophages contribute to age-related lung fibrosis

The aging lungs are vulnerable to chronic pulmonary diseases; however, the underlying mechanisms are not well understood. In this study, we compared the aging lungs of 20-24-month-old mice with the young of 10-16-week-old mice, and found that aging airway epithelial cells significantly upregulated the expression of uteroglobin-related protein 1 (UGRP1), which was responsible for the higher levels of CCL6 in the aging lungs. Alveolar macrophages (AMs) changed intrinsically with aging, exhibiting a decrease in cell number and altered gene expression. Using terminal differentiation trajectories, a population of MARCO⁺ AMs with the ability to produce CCL6 was identified in the aging lungs. Upregulated UGRP1was demonstrated to modulate CCL6 production of AMs in the UGRP1-MARCO pair in vivo and in vitro. Furthermore, MARCO⁺ AMs aggravated bleomycin-induced pulmonary fibrosis in a CCL6-dependent manner in the aged mice, and blocking MARCO or neutralizing CCL6 significantly inhibited pulmonary fibrosis, similar to the depletion of AMs. The age-related upregulation of UGRP1 and MARCO⁺ AMs, involved in the progression of lung fibrosis, was also observed in human lung tissues. Thus, UGRP1 modulated MARCO⁺ AMs regarding the age-related lung fibrosis in a CCL6-dependent manner, which is key to establishing optimal targeting for the aging population.

Single-cell RNA sequencing identifies hippocampal microglial dysregulation in diet-induced obesity

Obesity is a growing global concern in adults and youth with a parallel rise in associated complications, including cognitive impairment. Obesity induces brain inflammation and activates microglia, which contribute to cognitive impairment by aberrantly phagocytosing synaptic spines. Local and systemic signals, such as inflammatory cytokines and metabolites likely participate in obesity-induced microglial activation. However, the precise mechanisms mediating microglial activation during obesity remain incompletely understood. Herein, we leveraged our mouse model of high-fat diet (HFD)-induced obesity, which mirrors human obesity, and develops hippocampal-dependent cognitive impairment. We assessed hippocampal microglial activation by morphological and single-cell transcriptomic analysis to evaluate this heterogeneous, functionally diverse, and dynamic class of cells over time after 1 and 3 months of HFD. HFD altered cell-to-cell communication, particularly immune modulation and cellular adhesion signaling, and induced a differential gene expression signature of protein processing in the endoplasmic reticulum in a time-dependent manner.

Metabolic landscape in cardiac aging: insights into molecular biology and therapeutic implications

Cardiac aging is evident by a reduction in function which subsequently contributes to heart failure. The metabolic microenvironment has been identified as a hallmark of malignancy, but recent studies have shed light on its role in cardiovascular diseases (CVDs). Various metabolic pathways in cardiomyocytes and noncardiomyocytes determine cellular senescence in the aging heart. Metabolic alteration is a common process throughout cardiac degeneration. Importantly, the involvement of cellular senescence in cardiac injuries, including heart failure and myocardial ischemia and infarction, has been reported. However, metabolic complexity among human aging hearts hinders the development of strategies that targets metabolic susceptibility. Advances over the past decade have linked cellular senescence and function with their metabolic reprogramming pathway in cardiac aging, including autophagy, oxidative stress, epigenetic modifications, chronic inflammation, and myocyte systolic phenotype regulation. In addition, metabolic status is involved in crucial aspects of myocardial biology, from fibrosis to hypertrophy and chronic inflammation. However, further elucidation of the metabolism involvement in cardiac degeneration is still needed. Thus, deciphering the mechanisms underlying how metabolic reprogramming impacts cardiac aging is thought to contribute to the novel interventions to protect or even restore cardiac function in aging hearts. Here, we summarize emerging concepts about metabolic landscapes of cardiac aging, with specific focuses on why metabolic profile alters during cardiac degeneration and how we could utilize the current knowledge to improve the management of cardiac aging.

N-acetylneuraminic acid links immune exhaustion and accelerated memory deficit in diet-induced obese Alzheimer's disease mouse model

Systemic immunity supports lifelong brain function. Obesity posits a chronic burden on systemic immunity. Independently, obesity was shown as a risk factor for Alzheimer's disease (AD). Here we show that high-fat obesogenic diet accelerated recognition-memory impairment in an AD mouse model (5xFAD). In obese 5xFAD mice, hippocampal cells displayed only minor diet-related transcriptional changes, whereas the splenic immune landscape exhibited aging-like CD4+ T-cell deregulation. Following plasma metabolite profiling, we identified free N-acetylneuraminic acid (NANA), the predominant sialic acid, as the metabolite linking recognition-memory impairment to increased splenic immune-suppressive cells in mice. Single-nucleus RNA-sequencing revealed mouse visceral adipose macrophages as a potential source of NANA. In vitro, NANA reduced CD4+ T-cell proliferation, tested in both mouse and human. In vivo, NANA administration to standard diet-fed mice recapitulated high-fat diet effects on CD4+ T cells and accelerated recognition-memory impairment in 5xFAD mice. We suggest that obesity accelerates disease manifestation in a mouse model of AD via systemic immune exhaustion.

Lipid metabolism and Alzheimer's disease: clinical evidence, mechanistic link and therapeutic promise

Alzheimer's disease (AD) is an age-associated neurodegenerative disorder with multifactorial etiology, intersecting genetic and environmental risk factors, and a lack of disease-modifying therapeutics. While the abnormal accumulation of lipids was described in the very first report of AD neuropathology, it was not until recent decades that lipid dyshomeostasis became a focus of AD research. Clinically, lipidomic and metabolomic studies have consistently shown alterations in the levels of various lipid classes emerging in early stages of AD brains. Mechanistically, decades of discovery research have revealed multifaceted interactions between lipid metabolism and key AD pathogenic mechanisms including amyloidogenesis, bioenergetic deficit, oxidative stress, neuroinflammation, and myelin degeneration. In the present review, converging evidence defining lipid dyshomeostasis in AD is summarized, followed by discussions on mechanisms by which lipid metabolism contributes to pathogenesis and modifies disease risk. Furthermore, lipid-targeting therapeutic strategies, and the modification of their efficacy by disease stage, ApoE status, and metabolic and vascular profiles, are reviewed.

Nano-Brake Halts Mitochondrial Dysfunction Cascade to Alleviate Neuropathology and Rescue Alzheimer's Cognitive Deficits

Mitochondrial dysfunction has been recognized as the key pathogenesis of most neurodegenerative diseases including Alzheimer's disease (AD). The dysregulation of mitochondrial calcium ion (Ca2+ ) homeostasis and the mitochondrial permeability transition pore (mPTP), is a critical upstream signaling pathway that contributes to the mitochondrial dysfunction cascade in AD pathogenesis. Herein, a "two-hit braking" therapeutic strategy to synergistically halt mitochondrial Ca2+ overload and mPTP opening to put the mitochondrial dysfunction cascade on a brake is proposed. To achieve this goal, magnesium ion (Mg2+ ), a natural Ca2+ antagonist, and siRNA to the central mPTP regulator cyclophilin D (CypD), are co-encapsulated into the designed nano-brake; A matrix metalloproteinase 9 (MMP9) activatable cell-penetrating peptide (MAP) is anchored on the surface of nano-brake to overcome the blood-brain barrier (BBB) and realize targeted delivery to the mitochondrial dysfunction cells of the brain. Nano-brake treatment efficiently halts the mitochondrial dysfunction cascade in the cerebrovascular endothelial cells, neurons, and microglia and powerfully alleviates AD neuropathology and rescues cognitive deficits. These findings collectively demonstrate the potential of advanced design of nanotherapeutics to halt the key upstream signaling pathways of mitochondrial dysfunction to provide a powerful strategy for AD modifying therapy.

The pyruvate dehydrogenase complex: Life's essential, vulnerable and druggable energy homeostat

Found in all organisms, pyruvate dehydrogenase complexes (PDC) are the keystones of prokaryotic and eukaryotic energy metabolism. In eukaryotic organisms these multi-component megacomplexes provide a crucial mechanistic link between cytoplasmic glycolysis and the mitochondrial tricarboxylic acid (TCA) cycle. As a consequence, PDCs also influence the metabolism of branched chain amino acids, lipids and, ultimately, oxidative phosphorylation (OXPHOS). PDC activity is an essential determinant of the metabolic and bioenergetic flexibility of metazoan organisms in adapting to changes in development, nutrient availability and various stresses that challenge maintenance of homeostasis. This canonical role of the PDC has been extensively probed over the past decades by multidisciplinary investigations into its causal association with diverse physiological and pathological conditions, the latter making the PDC an increasingly viable therapeutic target. Here we review the biology of the remarkable PDC and its emerging importance in the pathobiology and treatment of diverse congenital and acquired disorders of metabolic integration.

Associations between dietary and blood inflammatory indices and their effects on cognitive function in elderly Americans

OBJECTIVE

To determine the correlations between dietary and blood inflammation indices in elderly Americans and their effects on cognitive function.

METHODS

This research extracted data from the 2011-2014 National Health and Nutrition Examination Survey for 2,479 patients who were ≥60 years old. Cognitive function was assessed as a composite cognitive function score (Z-score) calculated from the results of the Consortium to Establish a Registry for Alzheimer's Disease Word Learning and Delayed Recall tests, the Animal Fluency test, and the Digit Symbol Substitution Test. We used a dietary inflammatory index (DII) calculated from 28 food components to represent the dietary inflammation profile. Blood inflammation indicators included the white blood cell count (WBC), neutrophil count (NE), lymphocyte count (Lym), neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR), neutrophil-albumin ratio (NAR), systemic immune-inflammation index [SII, calculated as (peripheral platelet count) × NE/Lym], and systemic inflammatory response index [SIRI, calculated as (monocyte count) × NE/Lym]. WBC, NE, Lym, NLR, PLR, NAR, SII, SIRI, and DII were initially treated as continuous variables. For logistic regression, WBC, NE, Lym, NLR, PLR, NAR, SII, and SIRI were divided into quartile groups, and DII was divided into tertile groups.

RESULTS

After adjusting for covariates, WBC, NE, NLR, NAR, SII, SIRI, and DII scores were markedly higher in the cognitively impaired group than in the normal group (p < 0.05). DII was negatively correlated with the Z-score when combined with WBC, NE, and NAR (p < 0.05). After adjusting for all covariates, DII was positively correlated with SII in people with cognitive impairment (p < 0.05). Higher DII with NLR, NAR, SII, and SIRI all increased the risk of cognitive impairment (p < 0.05).

CONCLUSION

DII was positively correlated with blood inflammation indicators, and higher DII and blood inflammation indicators increased the risk of developing cognitive impairment.

Multiple characteristic alterations and available therapeutic strategies of cellular senescence

Given its state of stable proliferative inhibition, cellular senescence is primarily depicted as a critical mechanism by which organisms delay the progression of carcinogenesis. Cells undergoing senescence are often associated with the alteration of a series of specific features and functions, such as metabolic shifts, stemness induction, and microenvironment remodeling. However, recent research has revealed more complexity associated with senescence, including adverse effects on both physiological and pathological processes. How organisms evade these harmful consequences and survive has become an urgent research issue. Several therapeutic strategies targeting senescence, including senolytics, senomorphics, immunotherapy, and function restoration, have achieved initial success in certain scenarios. In this review, we describe in detail the characteristic changes associated with cellular senescence and summarize currently available countermeasures.

Preclinical development of an EP2 antagonist for post-seizure cognitive deficits

Cognitive comorbidities can substantially reduce quality of life in people with epilepsy. Inflammation is a component of all chronic diseases including epilepsy, as well as acute events like status epilepticus (SE). Neuroinflammation is the consequence of several broad signaling cascades including cyclooxygenase-2 (COX-2)-associated pathways. Activation of the EP2 receptor for prostaglandin E2 appears responsible for blood-brain barrier leakage and much of the inflammatory reaction, neuronal injury and cognitive deficit that follows seizure-provoked COX-2 induction in brain. Here we show that brief exposure of mice to TG11-77, a potent, selective, orally available and brain permeant EP2 antagonist, eliminates the profound cognitive deficit in Y-maze performance after SE and reduces delayed mortality and microgliosis, with a minimum effective i.p. dose (as free base) of 8.8 mg/kg. All in vitro studies required to submit an investigational new drug (IND) application for TG11-77 have been completed, and non-GLP dose range-finding toxicology in the rat identified no overt, organ or histopathology signs of toxicity after 7 days of oral administration at 1000 mg/kg/day. Plasma exposure in the rat was dose-linear between 15 and 1000 mg/kg dosing. TG11-77 thus appears poised to continue development towards the initial clinical test of the hypothesis that EP2 receptor modulation after SE can provide the first preventive treatment for one of the chief comorbidities of epilepsy.

Depression-related phenotypes at early stages of Aβ and tau accumulation in inducible Alzheimer's disease mouse model: Task-oriented and concept-driven interpretations

Depression is highly prevalent in Alzheimer Disease (AD); however, there is paucity of studies that focus specifically on the assessment of depression-relevant phenotypes in AD mouse models. Conditional doxycycline-dependent transgenic mouse models reproducing amyloidosis (TetOffAPPsi) and/or tau (TetOffTauP301L) pathology starting at middle age (6 months) were used in this study. As AD patients can experience depressive symptoms relatively early in disease, testing was conducted at early, pre-pathology stages of Aβ and/or tau accumulation (starting from 45 days of transgenes expression). Tau-related differences were detected in the Novelty Suppressed Feeding task (NSF), whereas APP-related differences were observed predominantly in measures of the Open Field (OF) and Forced Swim tasks (FST). Effects of combined production of Aβ and tau were detected in immobility during the 1st half of the Tail Suspension task (TST). These data demonstrate that results from different tasks are difficult to reconcile using task/variable-centered interpretations in which a single task/variable is assigned an ad-hoc meaning relevant to depression. An alternative, concept-oriented, approach is based on multiple variables/tests, with an understanding of their possible inter-dependence and utilization of statistical approaches that handle correlated data sets. The existence of strong correlations within and between some of the tasks supported utilization of factor analyses (FA). FA explained a similar amount of variability across the genotypes (∼80%) and identified two factors stable across genotypes and representing motor activity and anxiety measures in OF. In contrast, variables related to FST, TST, and NSFT did not demonstrate a structure of factor loadings that would support the existence of a single integral factor of "depressive state" measured by these tasks. In addition, factor loadings varied between genotypes, indicating that genotype-specific between-task correlations need to be considered for interpretations of findings in any single task. In general, this study demonstrates that utilization of multiple tasks to characterize behavioral phenotypes, an approach that is finally gaining more widespread adoption, requires a step of data integration across different behavioral tests for appropriate interpretations.

The relationship between serum klotho and cognitive performance in a nationally representative sample of US adults

Purpose

Aging is the primary risk factor for cognitive decline. Serum klotho, as an anti-aging protein, may be involved in cognitive decline. Thus, we aim to explorer the correlation between serum klotho and cognitive performance among an older adult population in the United States.

Methods

We performed a cross-sectional study using data from NHANES 2011-2014. Serum klotho was analyzed by ELISA. Cognitive function was measured by Establish a Registry for Alzheimer's Disease (CERAD) test, Animal Fluency test and Digit Symbol Substitution Test (DSST) score. The relationship between serum klotho and cognition was analyzed by a multivariable regression model.

Results

A total of 2,171 participants aged 60-79 years were included. Median serum klotho concentration was 851.52 pg./ml (SD = 294.07). We also categorized serum klotho concentrates into quartiles. After fully adjusting pertinent variables, compared to those with lowest klotho levels (206.3-658.4 pg./ml), individuals with highest klotho concentrates (983.3-3,456 pg./ml) had a higher CERAD score [β (95%CI): 0.97 (0.25, 1.69) p = 0.008] and DSST score [β (95%CI): 1.86 (0.25, 3.47), p = 0.024].

Conclusion

Our findings indicated that, among the general population of American older adults, serum klotho concentrates may serve as a marker of cognitive health. The benefits of klotho on aging process and neurodegenerative disorders should be paid more attention.

The age-dependent immune response to ischemic stroke

Stroke is a devastating cause of global morbidity and mortality. Ischemic brain injury triggers a profound local and systemic immune response that participates in stroke pathophysiology. In turn, this immune response has emerged as a potential therapeutic target. In order to maximize its therapeutic potential, it is critical to understand how the immune response to ischemic brain injury is affected by age - the strongest non-modifiable risk factor for stroke. The development of multi-omics and single-cell technologies has provided a more comprehensive characterization of transcriptional and cellular changes that occur during aging. In this review, we summarize recent advances in our understanding of how age-related immune alterations shape differential stroke outcomes in older versus younger organisms, highlighting studies in both experimental mouse models and patient cohorts. Wherever possible, we emphasize outstanding questions that present important avenues for future investigation with therapeutic value for the aging population.

Mechanisms Underlying Brain Aging Under Normal and Pathological Conditions

Aging is a major risk factor for many human diseases, including cognitive impairment, which affects a large population of the elderly. In the past few decades, our understanding of the molecular and cellular mechanisms underlying the changes associated with aging and age-related diseases has expanded greatly, shedding light on the potential role of these changes in cognitive impairment. In this article, we review recent advances in understanding of the mechanisms underlying brain aging under normal and pathological conditions, compare their similarities and differences, discuss the causative and adaptive mechanisms of brain aging, and finally attempt to find some rules to guide us on how to promote healthy aging and prevent age-related diseases.

S-Doped carbonized polymer dots inhibit early myocardial fibrosis by regulating mitochondrial function

Myocardial fibrosis (MF) is a critical pathological lesion in the progression of various acute and chronic cardiovascular diseases. However, there is still a lack of clinically effective drugs and treatments for MF therapies. Herein, for the first time, we developed fluorescent sulfur-doped carbonized polymer dots (S-CPDs) as new nano-antioxidants to reduce the cardiomyocyte damage caused by reactive oxygen species (ROS) in the early stage of fibrotic lesions. In vitro results suggested that the pre-protection of S-CPDs significantly increased the survival rate of H9c2 cells under severe oxidative stress, inhibited the isoproterenol (ISO)-induced hypertrophy of myocardial cells through improving the content of mitochondria related proteins and adenosine triphosphate (ATP) in cells. Moreover, S-CPD administration could effectively decrease cardiac hypertrophy and promote heart function in MF rat models. The rapid internalization, high biocompatibility and fluorescence imaging potential of S-CPDs revealed their promising application prospects in the diagnoses and treatments of cardiovascular diseases.

Immunosenescence of brain accelerates Alzheimer's disease progression

Most of Alzheimer's disease (AD) cases are sporadic and occur after age 65. With prolonged life expectancy and general population aging, AD is becoming a significant public health concern. The immune system supports brain development, plasticity, and homeostasis, yet it is particularly vulnerable to aging-related changes. Aging of the immune system, called immunosenescence, is the multifaceted remodeling of the immune system during aging. Immunosenescence is a contributing factor to various age-related diseases, including AD. Age-related changes in brain immune cell phenotype and function, crosstalk between immune cells and neural cells, and neuroinflammation work together to promote neurodegeneration and age-related cognitive impairment. Although numerous studies have confirmed the correlation between systemic immune changes and AD, few studies focus on the immune state of brain microenvironment in aging and AD. This review mainly addresses the changes of brain immune microenvironment in aging and AD. Specifically, we delineate how various aspects of the brain immune microenvironment, including immune gateways, immune cells, and molecules, and the interplay between immune cells and neural cells, accelerate AD pathogenesis during aging. We also propose a theoretical framework of therapeutic strategies selectively targeting the different mechanisms to restore brain immune homeostasis.

Biological Aging in People Living with HIV on Successful Antiretroviral Therapy: Do They Age Faster?

PURPOSE OF REVIEW

In the absence of a prophylactic/therapeutic vaccine or cure, the most amazing achievement in the battle against HIV was the discovery of effective, well-tolerated combination antiretroviral therapy (cART). The primary research question remains whether PLWH on prolonged successful therapy has accelerated, premature, or accentuated biological aging. In this review, we discuss the current understanding of the immunometabolic profile in PLWH, potentially associated with biological aging, and a better understanding of the mechanisms and temporal dynamics of biological aging in PLWH.

RECENT FINDINGS

Biological aging, defined by the epigenetic alterations analyzed by the DNA methylation pattern, has been reported in PLWH with cART that points towards epigenetic age acceleration. The hastened development of specific clinical geriatric syndromes like cardiovascular diseases, metabolic syndrome, cancers, liver diseases, neurocognitive diseases, persistent low-grade inflammation, and a shift toward glutamate metabolism in PLWH may potentiate a metabolic profile at-risk for accelerated aging.

The role of ApoE-mediated microglial lipid metabolism in brain aging and disease

Microglia are a unique population of immune cells resident in the brain that integrate complex signals and dynamically change phenotypes in response to the brain microenvironment. In recent years, single-cell sequencing analyses have revealed profound cellular heterogeneity and context-specific transcriptional plasticity of microglia during brain development, aging, and disease. Emerging evidence suggests that microglia adapt phenotypic plasticity by flexibly reprogramming cellular metabolism to fulfill distinct immune functions. The control of lipid metabolism is central to the appropriate function and homeostasis of the brain. Microglial lipid metabolism regulated by apolipoprotein E (ApoE), a crucial lipid transporter in the brain, has emerged as a critical player in regulating neuroinflammation. The ApoE gene allelic variant, ε4, is associated with a greater risk for neurodegenerative diseases. In this review, we explore novel discoveries in microglial lipid metabolism mediated by ApoE. We elaborate on the functional impact of perturbed microglial lipid metabolism on the underlying pathogenesis of brain aging and disease.

Hallmarks of aging: An expanding universe

Aging is driven by hallmarks fulfilling the following three premises: (1) their age-associated manifestation, (2) the acceleration of aging by experimentally accentuating them, and (3) the opportunity to decelerate, stop, or reverse aging by therapeutic interventions on them. We propose the following twelve hallmarks of aging: genomic instability, telomere attrition, epigenetic alterations, loss of proteostasis, disabled macroautophagy, deregulated nutrient-sensing, mitochondrial dysfunction, cellular senescence, stem cell exhaustion, altered intercellular communication, chronic inflammation, and dysbiosis. These hallmarks are interconnected among each other, as well as to the recently proposed hallmarks of health, which include organizational features of spatial compartmentalization, maintenance of homeostasis, and adequate responses to stress.

Knowledge domains and emerging trends of microglia research from 2002 to 2021: A bibliometric analysis and visualization study

Background

Microglia have been identified for a century. In this period, their ontogeny and functions have come to light thanks to the tireless efforts of scientists. However, numerous documents are being produced, making it challenging for scholars, especially those new to the field, to understand them thoroughly. Therefore, having a reliable method for quickly grasping a field is crucial.

Methods

We searched and downloaded articles from the Web of Science Core Collection with "microglia" or "microglial" in the title from 2002 to 2021. Eventually, 12,813 articles were located and, using CiteSpace and VOSviewer, the fundamental data, knowledge domains, hot spots, and emerging trends, as well as the influential literature in the field of microglia research, were analyzed.

Results

Following 2011, microglia publications grew significantly. The two prominent journals are Glia and J Neuroinflamm. The United States and Germany dominated the microglia study. The primary research institutions are Harvard Univ and Univ Freiburg, and the leading authors are Prinz Marco and Kettenmann Helmut. The knowledge domains of microglia include eight directions, namely neuroinflammation, lipopolysaccharide, aging, neuropathic pain, macrophages, Alzheimer's disease, retina, and apoptosis. Microglial phenotype is the focus of research; while RNA-seq, exosome, and glycolysis are emerging topics, a microglial-specific marker is still a hard stone. We also identified 19 influential articles that contributed to the study of microglial origin (Mildner A 2007; Ginhoux F 2010), identity (Butovsky O 2014), homeostasis (Cardona AE 2006; Elmore MRP 2014); microglial function such as surveillance (Nimmerjahn A 2005), movement (Davalos D 2005; Haynes SE 2006), phagocytosis (Simard AR 2006), and synapse pruning (Wake H 2009; Paolicelli RC 2011; Schafer DP 2012; Parkhurst CN 2013); and microglial state/phenotype associated with disease (Keren-Shaul H 2017), as well as 5 review articles represented by Kettenmann H 2011.

Conclusion

Using bibliometrics, we have investigated the fundamental data, knowledge structure, and dynamic evolution of microglia research over the previous 20 years. We hope this study can provide some inspiration and a reference for researchers studying microglia in neuroscience.

Frailty Improvement by Multicomponent Drug, Ninjin'Yoeito, in Mild Cognitive Impairment and Mild Alzheimer's Disease Patients: An Open-Label Exploratory Study (FRAMINGO)

Background

Alzheimer's disease (AD) and dementia have increasingly been conceived of as "complex diseases of aging", determined by multiple, simultaneous, interacting pathophysiological processes. The condition known as frailty is a phenotype of aging and its comprehensive pathophysiology is thought to be closely related to the incidence of mild cognitive impairment (MCI) and the exacerbation of dementia.

Objective

This study aimed to investigate the effect of the multicomponent drug, ninjin'yoeito (NYT), on frailty in MCI and mild AD patients.

Methods

This study was an open-label trial. A total of 14 patients, including 9 with MCI and 5 with mild AD, were enrolled. Among them, 11 were frail while 3 were prefrail. NYT (6-9 g/day) was administered orally for 24 weeks, and assessments were carried out at baseline (week 0), and at 4, 8, 16, and 24 weeks.

Results

In the primary endpoint, significant early improvements were observed in the anorexia scores according to the Neuropsychiatric Inventory after four weeks of treatment with NYT. The Cardiovascular Health Study score was significantly improved, and no frailty was observed after 24 weeks. The fatigue visual analog scale scores also significantly improved. The Clinical Dementia Rating and the Montreal Cognitive Assessment scores remained at baseline levels during the NYT treatment period.

Conclusion

The results suggest that NYT may be effective in the treatment of frailty, especially for anorexia and fatigue, in both MCI and mild AD patients, which would be beneficial for the prognosis of dementia.

Adipose tissue aging: An update on mechanisms and therapeutic strategies

Aging is a complex biological process characterized by a progressive loss of physiological integrity and increased vulnerability to age-related diseases. Adipose tissue plays central roles in the maintenance of whole-body metabolism homeostasis and has recently attracted significant attention as a biological driver of aging and age-related diseases. Here, we review the most recent advances in our understanding of the molecular and cellular mechanisms underlying age-related decline in adipose tissue function. In particular, we focus on the complex inter-relationship between metabolism, immune, and sympathetic nervous system within adipose tissue during aging. Moreover, we discuss the rejuvenation strategies to delay aging and extend lifespan, including senescent cell ablation (senolytics), dietary intervention, physical exercise, and heterochronic parabiosis. Understanding the pathological mechanisms that underlie adipose tissue aging will be critical for the development of new intervention strategies to slow or reverse aging and age-related diseases.

Microglia: A pharmacological target for the treatment of age-related cognitive decline and Alzheimer's disease

As individuals age, microglia, the resident immune cells of the central nervous system (CNS), become less effective at preserving brain circuits. Increases in microglial inflammatory activity are thought to contribute to age-related declines in cognitive functions and to transitions toward mild cognitive impairment (MCI) and Alzheimer's disease (AD). As microglia possess receptors for communicating with the CNS environment, pharmacological therapies targeting these pathways hold potential for promoting homeostatic microglial functions within the aging CNS. Preclinical and early phase clinical trials investigating the therapeutic effects of pharmacological agents acting on microglia, including reactive oxygen species, TREM2, fractalkine signaling, the complement cascade, and the NLRP3 inflammasome, are currently underway; however, important questions remain unanswered. Current challenges include target selectivity, as many of the signaling pathways are expressed in other cell types. Furthermore, microglia are a heterogenous cell population with transcriptomic, proteomic, and microscopy studies revealing distinct microglial states, whose activities and abundance shift across the lifespan. For example, homeostatic microglia can transform into pathological states characterized by markers of oxidative stress. Selective pharmacological targeting aimed at limiting transitions to pathological states or promoting homeostatic or protective states, could help to avoid potentially harmful off-target effects on beneficial states or other cell types. In this mini-review we cover current microglial pathways of interest for the prevention and treatment of age-related cognitive decline and CNS disorders of aging focusing on MCI and AD. We also discuss the heterogeneity of microglia described in these conditions and how pharmacological agents could target specific microglial states.

Long-term potentiation and depression regulatory microRNAs were highlighted in Bisphenol A induced learning and memory impairment by microRNA sequencing and bioinformatics analysis

The mechanisms of Bisphenol A (BPA) induced learning and memory impairment have still not been fully elucidated. MicroRNAs (miRNAs) are endogenous non-coding small RNA molecules involved in the process of toxicant-induced neurotoxicity. To investigate the role of miRNAs in BPA-induced learning and memory impairment, we analyzed the impacts of BPA on miRNA expression profile by high-throughput sequencing in mice hippocampus. Results showed that mice treated with BPA displayed impairments of spatial learning and memory and changes in the expression of miRNAs in the hippocampus. Seventeen miRNAs were significantly differentially expressed after BPA exposure, of these, 13 and 4 miRNAs were up- and downregulated, respectively. Bioinformatic analysis of Gene Ontology (GO) and pathway suggests that BPA exposure significantly triggered transcriptional changes of miRNAs associated with learning and memory; the top five affected pathways involved in impairment of learning and memory are: 1) Long-term depression (LTD); 2) Thyroid hormone synthesis; 3) GnRH signaling pathway; 4) Long-term potentiation (LTP); 5) Serotonergic synapse. Eight BPA-responsive differentially expressed miRNAs regulating LTP and LTD were further screened to validate the miRNA sequencing data using Real-Time PCR. The deregulation expression levels of proteins of five target genes (CaMKII, MEK1/2, IP3R, AMPAR1 and PLCβ4) were investigated via western blot, for further verifying the results of gene target analysis. Our results showed that LTP and LTD related miRNAs and their targets could contribute to BPA-induced impairment of learning and memory. This study provides valuable information for novel miRNA biomarkers to detect changes in impairment of learning and memory induced by BPA exposure.

Abnormal glucose metabolism in virus associated sepsis

Sepsis is identified as a potentially lethal organ impairment triggered by an inadequate host reaction to infection (Sepsis-3). Viral sepsis is a potentially deadly organ impairment state caused by the host's inappropriate reaction to a viral infection. However, when a viral infection occurs, the metabolism of the infected cell undergoes a variety of changes that cause the host to respond to the infection. But, until now, little has been known about the challenges faced by cellular metabolic alterations that occur during viral infection and how these changes modulate infection. This study concentrates on the alterations in glucose metabolism during viral sepsis and their impact on viral infection, with a view to exploring new potential therapeutic targets for viral sepsis.

Metabolic Reprogramming of Microglia in Sepsis-Associated Encephalopathy: Insights from Neuroinflammation

Sepsis-associated encephalopathy (SAE) is a diffuse brain dysfunction caused by sepsis that manifests as a range of brain dysfunctions from delirium to coma. It is a relatively common complication of sepsis associated with poor patient prognosis and mortality. The pathogenesis of SAE involves neuroinflammatory responses, neurotransmitter dysfunction, blood-brain barrier (BBB) disruption, abnormal blood flow regulation, etc. Neuroinflammation caused by hyperactivation of microglia is considered to be a key factor in disease development, which can cause a series of chain reactions, including BBB disruption and oxidative stress. Metabolic reprogramming has been found to play a central role in microglial activation and executive functions. In this review, we describe the pivotal role of energy metabolism in microglial activation and functional execution and demonstrate that the regulation of microglial metabolic reprogramming might be crucial in the development of clinical therapeutics for neuroinflammatory diseases like SAE.

FoxO3 Regulates the Progress and Development of Aging and Aging-Related Diseases

Aging is an inevitable risk factor for many diseases, including cardiovascular diseases, neurodegenerative diseases, cancer, and diabetes. Investigation into the molecular mechanisms involved in aging and longevity will benefit the treatment of age-dependent diseases and the development of preventative medicine for agingrelated diseases. Current evidence has revealed that FoxO3, encoding the transcription factor (FoxO)3, a key transcription factor that integrates different stimuli in the intrinsic and extrinsic pathways and is involved in cell differentiation, protein homeostasis, stress resistance and stem cell status, plays a regulatory role in longevity and in age-related diseases. However, the precise mechanisms by which the FoxO3 transcription factor modulates aging and promotes longevity have been unclear until now. Here, we provide a brief overview of the mechanisms by which FoxO3 mediates signaling in pathways involved in aging and aging-related diseases, as well as the current knowledge on the role of the FoxO3 transcription factor in the human lifespan and its clinical prospects. Ultimately, we conclude that FoxO3 signaling pathways, including upstream and downstream molecules, may be underlying therapeutic targets in aging and age-related diseases.

Secreted phosphoprotein 1 slows neurodegeneration and rescues visual function in mouse models of aging and glaucoma

Aging causes an irreversible, cumulative decline in neuronal function. Using the visual system as a model, we show that astrocytes play a critical role in maintaining retinal ganglion cell health and that deletion of SPP1 (secreted phosphoprotein 1, or osteopontin) from astrocytes leads to increased vulnerability of ganglion cells to age, elevated intraocular pressure, and traumatic optic nerve damage. Overexpression of SPP1 slows the age-related decline in ganglion cell numbers and is highly protective of visual function in a mouse model of glaucoma. SPP1 acts by promoting phagocytosis and secretion of neurotrophic factors while inhibiting production of neurotoxic and pro-inflammatory factors. SPP1 up-regulates transcription of genes related to oxidative phosphorylation, functionally enhances mitochondrial respiration, and promotes the integrity of mitochondrial microstructure. SPP1 increases intracellular ATP concentration via up-regulation of VDAC1.

Association of leukocyte mitochondrial DNA copy number with longitudinal C-reactive protein levels and survival in older adults: a cohort study

BACKGROUND

Systemic chronic inflammation occurs with age. The association of the leukocyte mitochondrial DNA copy number, a measure of mitochondrial function in aging, with the temporal profile of serum high-sensitivity C-reactive protein and mortality risk remains uncertain. The objectives of this study were to examine the association of the leukocyte mitochondrial DNA copy number with longitudinal high-sensitivity C-reactive protein levels and the association of the longitudinal high-sensitivity C-reactive protein levels with mortality risk.

METHODS

This prospective cohort study included 3928 adults aged ≥ 55 years without systemic inflammation in the baseline examination of the Healthy Aging Longitudinal Study in Taiwan, which started in 2009. Each participant received leukocyte mitochondrial DNA copy number measurement using a fluorescence-based quantitative polymerase chain reaction at baseline, serum high-sensitivity C-reactive protein measurements at baseline and the follow-up examination five years later, and the ascertainment of all-cause death (until November 30, 2021). The relationships among the leukocyte mitochondrial DNA copy number, longitudinal serum high-sensitivity C-reactive protein levels, and time to all-cause mortality were examined using the joint longitudinal and survival modeling analysis.

RESULTS

Of the 3928 participants (mean age: 69 years; 2060 [52%] were women), 837 (21%) died during follow-up. In the adjusted analysis, one standard deviation lower natural log-transformed baseline leukocyte mitochondrial DNA copy number was associated with an increase of 0.05 (95% confidence interval [CI], 0.02 to 0.08) standard deviation in serum high-sensitivity C-reactive protein in subsequent years. An increase of 1 standard deviation in instantaneous high-sensitivity C-reactive protein levels was associated with a hazard ratio (HR) for all-cause mortality of 1.22 (95% CI, 1.14 to 1.30). Similar results were obtained after further adjusting for baseline high-sensitivity C-reactive protein levels (HR [95% CI], 1.27 [1.16 to 1.38]) and after excluding those with serum high-sensitivity C-reactive protein above 10 mg/L (HR [95% CI], 1.21[1.11 to 1.31]) or 3 mg/L (HR [95% CI], 1.19 [1.06 to 1.31]) during follow-up.

CONCLUSIONS

A lower leukocyte mitochondrial DNA copy number was associated with persistently higher high-sensitivity C-reactive protein levels. Moreover, these higher time-varying high-sensitivity C-reactive protein levels were instantaneously associated with a higher risk of death.

Skeletal interoception in bone homeostasis and pain

Accumulating evidence indicates that interoception maintains proper physiological status and orchestrates metabolic homeostasis by regulating feeding behaviors, glucose balance, and lipid metabolism. Continuous skeletal remodeling consumes a tremendous amount of energy to provide skeletal scaffolding, support muscle movement, store vital minerals, and maintain a niche for hematopoiesis, which are processes that also contribute to overall metabolic balance. Although skeletal innervation has been described for centuries, recent work has shown that skeletal metabolism is tightly regulated by the nervous system and that skeletal interoception regulates bone homeostasis. Here, we provide a general discussion of interoception and its effects on the skeleton and whole-body metabolism. We also discuss skeletal interoception-mediated regulation in the context of pathological conditions and skeletal pain as well as future challenges to our understanding of these process and how they can be leveraged for more effective therapy.

The landscape of aging

Aging is characterized by a progressive deterioration of physiological integrity, leading to impaired functional ability and ultimately increased susceptibility to death. It is a major risk factor for chronic human diseases, including cardiovascular disease, diabetes, neurological degeneration, and cancer. Therefore, the growing emphasis on "healthy aging" raises a series of important questions in life and social sciences. In recent years, there has been unprecedented progress in aging research, particularly the discovery that the rate of aging is at least partly controlled by evolutionarily conserved genetic pathways and biological processes. In an attempt to bring full-fledged understanding to both the aging process and age-associated diseases, we review the descriptive, conceptual, and interventive aspects of the landscape of aging composed of a number of layers at the cellular, tissue, organ, organ system, and organismal levels.

Dual roles of hexokinase 2 in shaping microglial function by gating glycolytic flux and mitochondrial activity

Microglia continuously survey the brain parenchyma and actively shift status following stimulation. These processes demand a unique bioenergetic programme; however, little is known about the metabolic determinants in microglia. By mining large datasets and generating transgenic tools, here we show that hexokinase 2 (HK2), the most active isozyme associated with mitochondrial membrane, is selectively expressed in microglia in the brain. Genetic ablation of HK2 reduced microglial glycolytic flux and energy production, suppressed microglial repopulation, and attenuated microglial surveillance and damage-triggered migration in male mice. HK2 elevation is prominent in immune-challenged or disease-associated microglia. In ischaemic stroke models, however, HK2 deletion promoted neuroinflammation and potentiated cerebral damages. The enhanced inflammatory responses after HK2 ablation in microglia are associated with aberrant mitochondrial function and reactive oxygen species accumulation. Our study demonstrates that HK2 gates both glycolytic flux and mitochondrial activity to shape microglial functions, changes of which contribute to metabolic abnormalities and maladaptive inflammation in brain diseases.

Erythropoietin signaling in peripheral macrophages is required for systemic β-amyloid clearance

Impaired clearance of beta-amyloid (Aβ) is a primary cause of sporadic Alzheimer's disease (AD). Aβ clearance in the periphery contributes to reducing brain Aβ levels and preventing Alzheimer's disease pathogenesis. We show here that erythropoietin (EPO) increases phagocytic activity, levels of Aβ-degrading enzymes, and Aβ clearance in peripheral macrophages via PPARγ. Erythropoietin is also shown to suppress Aβ-induced inflammatory responses. Deletion of EPO receptor in peripheral macrophages leads to increased peripheral and brain Aβ levels and exacerbates Alzheimer's-associated brain pathologies and behavioral deficits in AD-model mice. Moreover, erythropoietin signaling is impaired in peripheral macrophages of old AD-model mice. Exogenous erythropoietin normalizes impaired EPO signaling and dysregulated functions of peripheral macrophages in old AD-model mice, promotes systemic Aβ clearance, and alleviates disease progression. Erythropoietin treatment may represent a potential therapeutic approach for Alzheimer's disease.

Activation of EP4 alleviates AKI-to-CKD transition through inducing CPT2-mediated lipophagy in renal macrophages

Acute kidney injury (AKI) is a common clinical syndrome with complex pathogenesis, characterized by a rapid decline in kidney function in the short term. Worse still, the incomplete recovery from AKI increases the risk of progression to chronic kidney disease (CKD). However, the pathogenesis and underlying mechanism remain largely unknown. Macrophages play an important role during kidney injury and tissue repair, but its role in AKI-to-CKD transition remains elusive. Herein, single nucleus RNA sequencing (snRNA-Seq) and flow cytometry validations showed that E-type prostaglandin receptor 4 (EP4) was selectively activated in renal macrophages, rather than proximal tubules, in ischemia-reperfusion injury (IRI)-induced AKI-to-CKD transition mouse model. EP4 inhibition aggravated AKI-to-CKD transition, while EP4 activation impeded the progression of AKI to CKD though regulating macrophage polarization. Mechanistically, network pharmacological analysis and subsequent experimental verifications revealed that the activated EP4 inhibited macrophage polarization through inducing Carnitine palmitoyltransferase 2 (CPT2)-mediated lipophagy in macrophages. Further, CPT2 inhibition abrogated the protective effect of EP4 on AKI-to-CKD transition. Taken together, our findings demonstrate that EP4-CPT2 signaling-mediated lipophagy in macrophages plays a pivotal role in the transition of AKI to CKD and targeting EP4-CPT2 axis could serve as a promising therapeutic approach for retarding AKI and its progression to CKD.

Age-induced prostaglandin E2 impairs mitochondrial fitness and increases mortality to influenza infection

Aging impairs the immune responses to influenza A virus (IAV), resulting in increased mortality to IAV infections in older adults. However, the factors within the aged lung that compromise host defense to IAV remain unknown. Using a murine model and human samples, we identified prostaglandin E2 (PGE2), as such a factor. Senescent type II alveolar epithelial cells (AECs) are overproducers of PGE2 within the aged lung. PGE2 impairs the proliferation of alveolar macrophages (AMs), critical cells for defense against respiratory pathogens, via reduction of oxidative phosphorylation and mitophagy. Importantly, blockade of the PGE2 receptor EP2 in aged mice improves AM mitochondrial function, increases AM numbers and enhances survival to IAV infection. In conclusion, our study reveals a key mechanism that compromises host defense to IAV, and possibly other respiratory infections, with aging and suggests potential new therapeutic or preventative avenues to protect against viral respiratory disease in older adults.

The brain-immune ecosystem: Implications for immunotherapy in defeating neurodegenerative diseases

Recent functional and anatomical discoveries of brain-immune relationships have overturned previous beliefs regarding the brain's immune privilege. Here, we propose that the brain and immune cells at its borders operate as an "ecosystem" to support the brain's robustness and resilience. Modulation of this ecosystem can be harnessed in the clinic.

Plasmalogens and platelet-activating factor roles in chronic inflammatory diseases

Fatty acids and phospholipid molecules are essential for determining the structure and function of cell membranes, and they hence participate in many biological processes. Platelet activating factor (PAF) and its precursor plasmalogen, which represent two subclasses of ether phospholipids, have attracted increasing research attention recently due to their association with multiple chronic inflammatory, neurodegenerative, and metabolic disorders. These pathophysiological conditions commonly involve inflammatory processes linked to an excess presence of PAF and/or decreased levels of plasmalogens. However, the molecular mechanisms underlying the roles of plasmalogens in inflammation have remained largely elusive. While anti-inflammatory responses most likely involve the plasmalogen signal pathway; pro-inflammatory responses recruit arachidonic acid, a precursor of pro-inflammatory lipid mediators which is released from membrane phospholipids, notably derived from the hydrolysis of plasmalogens. Plasmalogens per se are vital membrane phospholipids in humans. Changes in their homeostatic levels may alter cell membrane properties, thus affecting key signaling pathways that mediate inflammatory cascades and immune responses. The plasmalogen analogs of PAF are also potentially important, considering that anti-PAF activity has strong anti-inflammatory effects. Plasmalogen replacement therapy was further identified as a promising anti-inflammatory strategy allowing for the relief of pathological hallmarks in patients affected by chronic diseases with an inflammatory component. The aim of this Short Review is to highlight the emerging roles and implications of plasmalogens in chronic inflammatory disorders, along with the promising outcomes of plasmalogen replacement therapy for the treatment of various PAF-related chronic inflammatory pathologies.

Targeting the immune system towards novel therapeutic avenues to fight brain aging and neurodegeneration

The incidence of age-related dementia is growing with increased longevity, yet there are currently no disease-modifying therapies for these devastating disorders. Studies over the last several years have led to an evolving awareness of the role of the immune system in supporting brain maintenance and repair, displaying a diverse repertoire of functions while orchestrating the crosstalk between the periphery and the brain. Here, we provide insights into the current understanding of therapeutic targets that could be adopted to modulate immune cell fate, either systemically or locally, to defeat brain aging and neurodegeneration.

Neuro-Immune Interactions in Severe COVID-19 Infection

SARS-CoV-2 is a new coronavirus that has affected the world since 2019. Interstitial pneumonia is the most common clinical presentation, but additional symptoms have been reported, including neurological manifestations. Severe forms of infection, especially in elderly patients, present as an excessive inflammatory response called "cytokine storm", which can lead to acute respiratory distress syndrome (ARDS), multiorgan failure and death. Little is known about the relationship between symptoms and clinical outcomes or the characteristics of virus-host interactions. The aim of this narrative review is to highlight possible links between neurological involvement and respiratory damage mediated by pathological inflammatory pathways in SARS-CoV-2 infection. We will focus on neuro-immune interactions and age-related immunity decline and discuss some pathological mechanisms that contribute to negative outcomes in COVID-19 patients. Furthermore, we will describe available therapeutic strategies and their effects on COVID-19 neurological symptoms.

A Non-Randomized Combined Program of Walking and Low-Load Resistance Exercise Improves Cognitive Function and Cardiometabolic Risk Factors in Community-Dwelling Elderly Women

Background: This study examines whether changes in cardiometabolic risk factors, functional fitness, and depressive symptoms following a six-month exercise intervention were associated with cognitive function in Korean women aged 65 years and older. Methods: A non-randomized study design was used to compare post-intervention changes in measured variables between control (n = 30) and exercise (n = 30) groups. The exercise intervention consisted of three days of low-load resistance exercise and two days of walking. Cognitive function and depressive symptoms were assessed with the Korean version of the Mini−Mental State Examination and the Korean version of the Geriatric Depression Scale, respectively. Functional fitness was measured using a senior fitness test battery. Results: The exercise group showed a significant improvement in cognitive function (p < 0.001) in conjunction with significant decreases in blood glucose (p = 0.052), triglycerides (p = 0.011), insulin (p = 0.002), tumor necrosis factor-α (p = 0.043), and depressive symptoms (p = 0.006) and an increase in interleukin-10 (p = 0.037), compared with the control group. Multivariate stepwise regression showed that changes in depressive symptoms (p < 0.001), insulin resistance (p < 0.001), and upper body muscle strength (p = 0.003) were positively associated with cognitive function. Conclusion: A six-month exercise intervention consisting of walking and low-load/high-repetition elastic band resistance exercise has the potential to improve cognitive function, as well as physical function and cardiometabolic risk factors, and to decrease depressive symptoms in older women.