Adipose tissue inflammation in aging

Investigating the role of adipose tissue in mobility and aging: design and methods of the Adipose Tissue ancillary to the Study of Muscle, Mobility, and Aging (SOMMA-AT)

BACKGROUND

Age-related changes in adipose tissue affect chronic medical diseases and mobility disability but mechanism remains poorly understood. The goal of this study is to define methods for phenotyping unique characteristics of adipose tissue from older adults.

METHODS

Older adults enrolled in study of muscle, mobility, and aging selected for the adipose tissue ancillary (SOMMA-AT; N = 210, 52.38% women, 76.12 ± 4.37 years) were assessed for regional adiposity by whole-body magnetic resonance (AMRA) and underwent a needle-aspiration biopsy of abdominal subcutaneous adipose tissue (ASAT). ASAT biopsies were flash frozen, fixed, or processed for downstream applications and deposited at the biorepository. Biopsy yields, qualitative features, adipocyte sizes, and concentration of adipokines secreted in ASAT explant conditioned media were measured. Inter-measure Spearman correlations were determined.

RESULTS

Regional, but not total, adiposity differed by sex: women had greater ASAT mass (8.20 ± 2.73 kg, p < .001) and biopsy yield (3.44 ± 1.81 g, p < .001) than men (ASAT = 5.95 ± 2.30 kg, biopsy = 2.30 ± 1.40 g). ASAT mass correlated with leptin (r = 0.54, p < .001) and not resistin (p = .248) and adiponectin (p = .353). Adipocyte area correlated with ASAT mass (r = 0.34, p < .001), BMI (r = 0.33, p < .001), adiponectin (r = -0.22, p = .005) and leptin (r = 0.18, p = .024) but not with resistin (p = .490).

CONCLUSION

In addition to the detailed ASAT biopsy processing in this report, we found that adipocyte area correlated with ASAT mass, and both measures related to some key adipokines in the explant conditioned media. These results, methods, and biological repositories underscore the potential of this unique cohort to impact the understanding of aging adipose biology on disease, disability, and other aging tissues.

B-cell interleukin 1 receptor 1 modulates the female adipose tissue immune microenvironment during aging

Myeloid cell production of interleukin-1β (IL-1β) drives inflammaging in visceral white adipose tissue (vWAT) and contributes to the expansion of interleukin-1 receptor 1 (Il1r1)-positive aged adipose B cells (AABs). AABs promote metabolic dysfunction and inflammation under inflammatory challenges. However, whether IL-1β contributes to AAB-associated inflammation during aging is unclear. Using a B-cell-specific knockout of Il1r1 (BKO mice), we characterized old vWAT in the absence of IL-1β-B-cell signaling. In addition to sex-specific metabolic improvements in females, we identified a reduction in the proportion of B cells and a sex-specific increase in the B1/B2 B-cell ratio in BKO vWAT. Using single-cell RNA sequencing of vWAT immune cells, we observed that BKO differentially affected inflammatory signaling in vWAT immune cells. These data suggest that IL-1β-B-cell signaling supports the inflammatory response in multiple cell types and provides insight into the complex microenvironment in aged vWAT.

The association of visceral fat metabolism score with hyperuricemia-evidence from NHANES 1999-2018

Objectives

Despite substantial evidence that visceral obesity is an epidemiological risk factor for hyperuricemia (HUA), studies on the connection between the Metabolic Score for Visceral Fat (METS-VF) and HUA remain insufficient. This research focused on METS-VF's potential role as a risk factor for HUA.

Methods

Notably, 8,659 participants from the National Health and Nutrition Examination Survey (NHANES) from 1999 to 2018 were enrolled in this study. Propensity score matching (PSM), multivariate logistic regression analysis, subgroup analysis, interaction test, and restricted cubic spline (RCS) analysis were implemented to identify the correlation between METS-VF and HUA.

Results

In the fully adjusted model, the results of the multiple logistic regression analysis indicated that METS-VF was related to an elevated prevalence of HUA [before PSM: odds ratio (OR) = 3.51 (2.88, 4.27), p < 0.001; after PSM: OR = 2.90 (2.36, 3.58), p < 0.001]. In RCS analysis, a non-linear positive correlation was observed between METS-VF and the incidence of HUA (before PSM: p-non-linear <0.001; after PSM: p-non-linear = 0.0065). Subgroup analysis and interaction tests revealed that the impact of METS-VF on HUA was modified by sex and ethnicity.

Conclusion

There is a significant positive correlation between METS-VF and HUA in adults in the United States. METS-VF could serve as a valuable metric for assessing the development and progression of HUA.

Global consensus on optimal exercise recommendations for enhancing healthy longevity in older adults (ICFSR)

Aging, a universal and inevitable process, is characterized by a progressive accumulation of physiological alterations and functional decline over time, leading to increased vulnerability to diseases and ultimately mortality as age advances. Lifestyle factors, notably physical activity (PA) and exercise, significantly modulate aging phenotypes. Physical activity and exercise can prevent or ameliorate lifestyle-related diseases, extend health span, enhance physical function, and reduce the burden of non-communicable chronic diseases including cardiometabolic disease, cancer, musculoskeletal and neurological conditions, and chronic respiratory diseases as well as premature mortality. Physical activity influences the cellular and molecular drivers of biological aging, slowing aging rates-a foundational aspect of geroscience. Thus, PA serves both as preventive medicine and therapeutic agent in pathological states. Sub-optimal PA levels correlate with increased disease prevalence in aging populations. Structured exercise prescriptions should therefore be customized and monitored like any other medical treatment, considering the dose-response relationships and specific adaptations necessary for intended outcomes. Current guidelines recommend a multifaceted exercise regimen that includes aerobic, resistance, balance, and flexibility training through structured and incidental (integrated lifestyle) activities. Tailored exercise programs have proven effective in helping older adults maintain their functional capacities, extending their health span, and enhancing their quality of life. Particularly important are anabolic exercises, such as Progressive resistance training (PRT), which are indispensable for maintaining or improving functional capacity in older adults, particularly those with frailty, sarcopenia or osteoporosis, or those hospitalized or in residential aged care. Multicomponent exercise interventions that include cognitive tasks significantly enhance the hallmarks of frailty (low body mass, strength, mobility, PA level, and energy) and cognitive function, thus preventing falls and optimizing functional capacity during aging. Importantly, PA/exercise displays dose-response characteristics and varies between individuals, necessitating personalized modalities tailored to specific medical conditions. Precision in exercise prescriptions remains a significant area of further research, given the global impact of aging and broad effects of PA. Economic analyses underscore the cost benefits of exercise programs, justifying broader integration into health care for older adults. However, despite these benefits, exercise is far from fully integrated into medical practice for older people. Many healthcare professionals, including geriatricians, need more training to incorporate exercise directly into patient care, whether in settings including hospitals, outpatient clinics, or residential care. Education about the use of exercise as isolated or adjunctive treatment for geriatric syndromes and chronic diseases would do much to ease the problems of polypharmacy and widespread prescription of potentially inappropriate medications. This intersection of prescriptive practices and PA/exercise offers a promising approach to enhance the well-being of older adults. An integrated strategy that combines exercise prescriptions with pharmacotherapy would optimize the vitality and functional independence of older people whilst minimizing adverse drug reactions. This consensus provides the rationale for the integration of PA into health promotion, disease prevention, and management strategies for older adults. Guidelines are included for specific modalities and dosages of exercise with proven efficacy in randomized controlled trials. Descriptions of the beneficial physiological changes, attenuation of aging phenotypes, and role of exercise in chronic disease and disability management in older adults are provided. The use of exercise in cardiometabolic disease, cancer, musculoskeletal conditions, frailty, sarcopenia, and neuropsychological health is emphasized. Recommendations to bridge existing knowledge and implementation gaps and fully integrate PA into the mainstream of geriatric care are provided. Particular attention is paid to the need for personalized medicine as it applies to exercise and geroscience, given the inter-individual variability in adaptation to exercise demonstrated in older adult cohorts. Overall, this consensus provides a foundation for applying and extending the current knowledge base of exercise as medicine for an aging population to optimize health span and quality of life.

Crosstalk between adipogenesis and aging: role of polyphenols in combating adipogenic-associated aging

In the last forty years, the number of people over 60 years of age has increased significantly owing to better nutrition and lower rates of infectious diseases in developing countries. Aging significantly impacts adipose tissue, which plays crucial role in hormone regulation and energy storage. This can lead to imbalances in glucose, and overall energy homeostasis within the body. Aging is irreversible phenomena and potentially causing lipid infiltration in other organs, leading to systemic inflammation, metabolic disorders. This review investigates various pathways contributing to aging-related defects in adipogenesis, such as changes in adipose tissue function and distribution. Polyphenols, a diverse group of natural compounds, can mitigate aging effects via free radicals, oxidative stress, inflammation, senescence, and age-related diseases. Polyphenols like resveratrol, quercetin and EGCG exhibit distinct mechanisms and regulate crucial pathways, such as the TGF-β, AMPK, Wnt, PPAR-γ, and C/EBP transcription factors, and influence epigenetic modifications, such as DNA methylation and histone modification. This review highlights the critical importance of understanding the intricate relationship between aging and adipogenesis for optimizing well-being with increasing age. These findings highlight the therapeutic potential of polyphenols like quercetin and resveratrol in enhancing adipose tissue function and promoting healthy aging.

General Principles, Etiologies, Evaluation, and Management in Older Adults

Hypertension impacts most older adults as one of many multiple chronic conditions. A thorough evaluation is required to assess overall health, cardiovascular status, and comorbid conditions that impact treatment targets. In the absence of severe frailty or dementia, intensive treatment prevents more cardiovascular events than standard treatment and may slow cognitive decline. "Start low and go slow" is not the best strategy for many older adults as fewer cardiovascular events occur when hypertension is controlled within the first 3 to 6 months of treatment.

Body Composition and Senescence: Impact of Polyphenols on Aging-Associated Events

Aging is a dynamic and progressive process characterized by the gradual accumulation of cellular damage. The continuous functional decline in the intrinsic capacity of living organisms to precisely regulate homeostasis leads to an increased susceptibility and vulnerability to diseases. Among the factors contributing to these changes, body composition-comprised of fat mass and lean mass deposits-plays a crucial role in the trajectory of a disability. Particularly, visceral and intermuscular fat deposits increase with aging and are associated with adverse health outcomes, having been linked to the pathogenesis of sarcopenia. Adipose tissue is involved in the secretion of bioactive factors that can ultimately mediate inter-organ pathology, including skeletal muscle pathology, through the induction of a pro-inflammatory profile such as a SASP, cellular senescence, and immunosenescence, among other events. Extensive research has shown that natural compounds have the ability to modulate the mechanisms associated with cellular senescence, in addition to exhibiting anti-inflammatory, antioxidant, and immunomodulatory potential, making them interesting strategies for promoting healthy aging. In this review, we will discuss how factors such as cellular senescence and the presence of a pro-inflammatory phenotype can negatively impact body composition and lead to the development of age-related diseases, as well as how the use of polyphenols can be a functional measure for restoring balance, maintaining tissue quality and composition, and promoting health.

Aging alone or combined with obesity increases white adipose tissue inflammatory status in male mice

White adipose tissue (WAT) has been recognized as a fundamental and crucial organ of interest in research focusing on inflammation during obesity or aging. WAT is also proposed as a significant component of cholecalciferol and 25-hydroxyvitamin D (25(OH)D) storage, which participates in the decrease of 25(OH)D plasma levels reported during aging and obesity. In the present study, we evaluated WAT and plasma cholecalciferol and 25(OH)D content together with inflammatory status to highlight the putative relationship between vitamin D status and inflammatory process during aging alone or combined with obesity. Circulating cholecalciferol and 25(OH)D and the stored quantity of cholecalciferol and 25(OH)D in WAT were quantified in young and old mice fed a control or obesogenic diet. The inflammation was assessed by measuring plasma inflammatory cytokines, mRNA, and microRNAs inflammatory-associated in WAT. The combination of aging and obesity decreased 25(OH)D plasma levels but did not modify circulating inflammatory markers. A cumulative effect of aging and obesity was observed in WAT, with rising mRNA inflammatory cytokines, notably Ccl5 and Tnf. Interestingly, aging and obesity-associated were also characterized by increased inflammatory microRNA expression. The inflammatory parameters in WAT were negatively correlated with the plasma 25(OH)D but positively correlated with the quantity of cholecalciferol and 25(OH)D in WAT. These results support the cumulative effect of obesity and aging in aggravation of WAT inflammation and suggest that accumulation of cholecalciferol and 25(OH)D in WAT could constitute a mechanism to counteract WAT inflammation during aging and obesity.

T cells in obesity-associated inflammation: The devil is in the details

Obesity presents a significant health challenge, affecting 41% of adults and 19.7% of children in the United States. One of the associated health challenges of obesity is chronic low-grade inflammation. In both mice and humans, T cells in circulation and in the adipose tissue play a pivotal role in obesity-associated inflammation. Changes in the numbers and frequency of specific CD4+ Th subsets and their contribution to inflammation through cytokine production indicate declining metabolic health, that is, insulin resistance and T2D. While some Th subset alterations are consistent between mice and humans with obesity, some changes mainly characterize male mice, whereas female mice often resist obesity and inflammation. However, protection from obesity and inflammation is not observed in human females, who can develop obesity-related T-cell inflammation akin to males. The decline in female sex hormones after menopause is also implicated in promoting obesity and inflammation. Age is a second underappreciated factor for defining and regulating obesity-associated inflammation toward translating basic science findings to the clinic. Weight loss in mice and humans, in parallel with these other factors, does not resolve obesity-associated inflammation. Instead, inflammation persists amid modest changes in CD4+ T cell frequencies, highlighting the need for further research into resolving changes in T-cell function after weight loss. How lingering inflammation after weight loss affecting the common struggle to maintain lower weight is unknown. Semaglutide, a newly popular pharmaceutical used for treating T2D and reversing obesity, holds promise for alleviating obesity-associated health complications, yet its impact on T-cell-mediated inflammation remains unexplored. Further work in this area could significantly contribute to the scientific understanding of the impacts of weight loss and sex/hormones in obesity and obesity-associated metabolic decline.

The impact of the senescent microenvironment on tumorigenesis: Insights for cancer therapy

The growing global burden of cancer, especially among people aged 60 years and over, has become a key public health issue. This trend suggests the need for a deeper understanding of the various cancer types in order to develop universally effective treatments. A prospective area of research involves elucidating the interplay between the senescent microenvironment and tumor genesis. Currently, most oncology research focuses on adulthood and tends to ignore the potential role of senescent individuals on tumor progression. Senescent cells produce a senescence-associated secretory phenotype (SASP) that has a dual role in the tumor microenvironment (TME). While SASP components can remodel the TME and thus hinder tumor cell proliferation, they can also promote tumorigenesis and progression via pro-inflammatory and pro-proliferative mechanisms. To address this gap, our review seeks to investigate the influence of senescent microenvironment changes on tumor development and their potential implications for cancer therapies.

Plasticity of Adipose Tissues: Interconversion among White, Brown, and Beige Fat and Its Role in Energy Homeostasis

Obesity, characterized by the excessive accumulation of adipose tissue, has emerged as a major public health concern worldwide. To develop effective strategies for treating obesity, it is essential to comprehend the biological properties of different adipose tissue types and their respective roles in maintaining energy balance. Adipose tissue serves as a crucial organ for energy storage and metabolism in the human body, with functions extending beyond simple fat storage to encompass the regulation of energy homeostasis and the secretion of endocrine factors. This review provides an overview of the key characteristics, functional differences, and interconversion processes among white adipose tissue (WAT), brown adipose tissue (BAT), and beige adipose tissue. Moreover, it delves into the molecular mechanisms and recent research advancements concerning the browning of WAT, activation of BAT, and whitening of BAT. Although targeting adipose tissue metabolism holds promise as a potential approach for obesity treatment, further investigations are necessary to unravel the intricate biological features of various adipose tissue types and elucidate the molecular pathways governing their interconversion. Such research endeavors will pave the way for the development of more efficient and targeted therapeutic interventions in the fight against obesity.

Age-associated accumulation of B cells promotes macrophage inflammation and inhibits lipolysis in adipose tissue during sepsis

Non-canonical lipolysis induced by inflammatory cytokines or Toll-like receptor ligands is required for the regulation of inflammation during endotoxemia and sepsis. Canonical lipolysis induced by catecholamines declines during aging due to factors including an expansion of lymphocytes, pro-inflammatory macrophage polarization, and an increase in chronic low-grade inflammation; however, the extent to which the non-canonical pathway of lipolysis is active and impacted by immune cells during aging remains unclear. Therefore, we aimed to define the extent to which immune cells from old mice influence non-canonical lipolysis during sepsis. We identified age-associated impairments of non-canonical lipolysis and an accumulation of dysfunctional B1 B cells in the visceral white adipose tissue (vWAT) of old mice. Lifelong deficiency of B cells results in restored non-canonical lipolysis and reductions in pro-inflammatory macrophage populations. Our study suggests that targeting the B cell-macrophage signaling axis may resolve metabolic dysfunction in aged vWAT and attenuate septic severity in older individuals.

Endoplasmic Reticulum Stress and Its Impact on Adipogenesis: Molecular Mechanisms Implicated

Endoplasmic reticulum (ER) stress plays a pivotal role in adipogenesis, which encompasses the differentiation of adipocytes and lipid accumulation. Sustained ER stress has the potential to disrupt the signaling of the unfolded protein response (UPR), thereby influencing adipogenesis. This comprehensive review illuminates the molecular mechanisms that underpin the interplay between ER stress and adipogenesis. We delve into the dysregulation of UPR pathways, namely, IRE1-XBP1, PERK and ATF6 in relation to adipocyte differentiation, lipid metabolism, and tissue inflammation. Moreover, we scrutinize how ER stress impacts key adipogenic transcription factors such as proliferator-activated receptor γ (PPARγ) and CCAAT-enhancer-binding proteins (C/EBPs) along with their interaction with other signaling pathways. The cellular ramifications include alterations in lipid metabolism, dysregulation of adipokines, and aged adipose tissue inflammation. We also discuss the potential roles the molecular chaperones cyclophilin A and cyclophilin B play in adipogenesis. By shedding light on the intricate relationship between ER stress and adipogenesis, this review paves the way for devising innovative therapeutic interventions.

Lipids and the hallmarks of ageing: From pathology to interventions

Lipids are critical structural and functional architects of cellular homeostasis. Change in systemic lipid profile is a clinical indicator of underlying metabolic pathologies, and emerging evidence is now defining novel roles of lipids in modulating organismal ageing. Characteristic alterations in lipid metabolism correlate with age, and impaired systemic lipid profile can also accelerate the development of ageing phenotype. The present work provides a comprehensive review of the extent of lipids as regulators of the modern hallmarks of ageing viz., cellular senescence, chronic inflammation, gut dysbiosis, telomere attrition, genome instability, proteostasis and autophagy, epigenetic alterations, and stem cells dysfunctions. Current evidence on the modulation of each of these hallmarks has been discussed with emphasis on inherent age-dependent deficiencies in lipid metabolism as well as exogenous lipid changes. There appears to be sufficient evidence to consider impaired lipid metabolism as key driver of the ageing process although much of knowledge is yet fragmented. Considering dietary lipids, the type and quantity of lipids in the diet is a significant, but often overlooked determinant that governs the effects of lipids on ageing. Further research using integrative approaches amidst the known aging hallmarks is highly desirable for understanding the therapeutics of lipids associated with ageing.

Physiological Approaches Targeting Cellular and Mitochondrial Pathways Underlying Adipose Organ Senescence

The adipose organ is involved in many metabolic functions, ranging from the production of endocrine factors to the regulation of thermogenic processes. Aging is a natural process that affects the physiology of the adipose organ, leading to metabolic disorders, thus strongly impacting healthy aging. Cellular senescence modifies many functional aspects of adipose tissue, leading to metabolic alterations through defective adipogenesis, inflammation, and aberrant adipocytokine production, and in turn, it triggers systemic inflammation and senescence, as well as insulin resistance in metabolically active tissues, leading to premature declined physiological features. In the various aging fat depots, senescence involves a multiplicity of cell types, including mature adipocytes and immune, endothelial, and progenitor cells that are aging, highlighting their involvement in the loss of metabolic flexibility, one of the common features of aging-related metabolic disorders. Since mitochondrial stress represents a key trigger of cellular senescence, and senescence leads to the accumulation of abnormal mitochondria with impaired dynamics and hindered homeostasis, this review focuses on the beneficial potential of targeting mitochondria, so that strategies can be developed to manage adipose tissue senescence for the treatment of age-related metabolic disorders.

p16 INK4A drives nonalcoholic fatty liver disease phenotypes in high fat diet fed mice through biliary E2F1/FOXO1/IGF-1 signaling

BACKGROUND AND AIMS

NAFLD is characterized by steatosis, hepatic inflammation, and fibrosis, which can develop into NASH. Patients with NAFLD/NASH have increased ductular reaction (DR) and biliary senescence. High fat/high cholesterol diet feeding increases biliary senescence, DR, and biliary insulin-like growth factor-1 (IGF-1) expression in mice. p16/IGF-1 converges with fork-head box transcription factor O1 (FOXO1) through E2F1. We evaluated p16 inhibition on NAFLD phenotypes and biliary E2F1/FOXO1/IGF-1 signaling.

APPROACH AND RESULTS

4-week wild-type (C57BL/6J) male mice were fed a control diet (CD) or high fat/high cholesterol diet and received either p16 or control Vivo Morpholino (VM) by tail vein injection 2× during the 16th week of feeding. We confirmed p16 knockdown and examined: (i) NAFLD phenotypes; (ii) DR and biliary senescence; (iii) serum metabolites; and (iv) biliary E2F1/FOXO1/IGF-1 signaling. Human normal, NAFLD, and NASH liver samples and isolated cholangiocytes treated with control or p16 VM were evaluated for p16/E2F1/FOXO1/IGF-1 signaling. p16 VM treatment reduced cholangiocyte and hepatocyte p16. In wild-type high fat/high cholesterol diet mice with control VM, there were increased (i) NAFLD phenotypes; (ii) DR and biliary senescence; (iii) serum metabolites; and (iv) biliary E2F1/FOXO1/IGF-1 signaling; however, p16 VM treatment reduced these parameters. Biliary E2F1/FOX-O1/IGF-1 signaling increased in human NAFLD/NASH but was blocked by p16 VM. In vitro , p16 VM reduced biliary E2f1 and Foxo1 transcription by inhibiting RNA pol II binding and E2F1 binding at the Foxo1 locus, respectively. Inhibition of E2F1 reduced biliary FOXO1 in vitro.

CONCLUSION

Attenuating hepatic p16 expression may be a therapeutic approach for improving NAFLD/NASH phenotypes.

Age-related changes in adipose tissue metabolomics and inflammation, cardiolipin metabolism, and ferroptosis markers in female aged rat model

Aging adipose tissue exhibits elevated inflammation and oxidative stress that are major sources of age-related metabolic dysfunction. However, the exact metabolic changes associated with inflammation and oxidative stress are unclear. To address this topic, we assessed variation in metabolic phenotypes of adipose tissue from 18 months adult sedentary (ASED), 26 months old sedentary (OSED), and 8 months young sedentary (YSED). The results of metabolomic analysis showed that ASED and OSED group had higher palmitic acid, elaidic acid, 1-heptadecanol, and α-tocopherol levels than YSED, but lower sarcosine levels. Furthermore, stearic acid was specifically elevated in ASED compared with YSED. Cholesterol was upregulated specifically in the OSED group compared with YSED, whereas linoleic acid was downregulated. In addition, ASED and OSED had more inflammatory cytokines, lower antioxidant capacity, and higher expression of ferroptosis-related genes than YSED. Moreover, mitochondrial dysfunction associated with abnormal cardiolipin synthesis was more pronounced in the OSED group. In conclusion, both ASED and OSED can affect the FA metabolism and increase oxidative stress in adipose tissue, leading to inflammation. In particular, linoleic acid content specifically decreases in OSED, which associated with abnormal cardiolipin synthesis and mitochondrial dysfunction in adipose tissue.

Helminth-derived biomacromolecules as therapeutic agents for treating inflammatory and infectious diseases: What lessons do we get from recent findings?

Despite the tremendous progress in healthcare sectors, a number of life-threatening infectious, inflammatory, and autoimmune diseases are continuously challenging mankind throughout the globe. In this context, recent successes in utilizing helminth parasite-derived bioactive macromolecules viz. glycoproteins, enzymes, polysaccharides, lipids/lipoproteins, nucleic acids/nucleotides, and small organic molecules for treating various disorders primarily resulted from inflammation. Among the several parasites that infect humans, helminths (cestodes, nematodes, and trematodes) are known as efficient immune manipulators owing to their explicit ability to modulate and modify the innate and adaptive immune responses of humans. These molecules selectively bind to immune receptors on innate and adaptive immune cells and trigger multiple signaling pathways to elicit anti-inflammatory cytokines, expansion of alternatively activated macrophages, T-helper 2, and immunoregulatory T regulatory cell types to induce an anti-inflammatory milieu. Reduction of pro-inflammatory responses and repair of tissue damage by these anti-inflammatory mediators have been exploited for treating a number of autoimmune, allergic, and metabolic diseases. Herein, the potential and promises of different helminths/helminth-derived products as therapeutic agents in ameliorating immunopathology of different human diseases and their mechanistic insights of function at cell and molecular level alongside the molecular signaling cross-talks have been reviewed by incorporating up-to-date findings achieved in the field.

Bariatric Surgery and Vitamin D: Trends in Older Women and Association with Clinical Features and VDR Gene Polymorphisms

(1) Background: Obesity and its comorbidities can cause burdens and limitations. Bariatric surgery (BS) is indicated as a safe procedure to reduce body mass and improve present comorbidities. However, several complications were reported, such as vitamin D [25(OH)D] deficiency. We evaluated if 25(OH)D serum levels relate to clinical characteristics, symptoms, or habits in women after their BS, and whether the vitamin D receptor (VDR) gene's TaqI and FokI polymorphisms affected 25(OH)D levels and the total body bone mineral density (TBBMD). (2) Methods: This cohort cross-sectional comparative analytical prospective study consisted of 27 women, 61.6 ± 5.0 years, submitted to BS one year prior at a public reference hospital, DF-Brazil. All participants were asked to follow the physical and dietary activity recommendations and received vitamin D3 supplements. Their anthropometric, biochemical, and immunological measurements and blood samples were obtained. (3) Results: 73.3% of participants had low 25(OH)D levels, and their levels correlated positively with TBBMD and negatively with systolic pressure. VDR TaqI did not affect 25(OH)D levels, whereas VDR FokI's allele f presence correlated to a median rise in 25(OH)D levels. Neither polymorphism correlated to TBBMD. (4) Conclusions: 25(OH)D levels were positively correlated with TBBMD, negatively with systolic blood pressure, and were higher in those with the VDR FokI allele f.

SARS-CoV-2 infection induces persistent adipose tissue damage in aged golden Syrian hamsters

Coronavirus disease 2019 (COVID-19, caused by severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2)) is primarily a respiratory illness. However, various extrapulmonary manifestations have been reported in patients with severe forms of COVID-19. Notably, SARS-CoV-2 was shown to directly trigger white adipose tissue (WAT) dysfunction, which in turn drives insulin resistance, dyslipidemia, and other adverse outcomes in patients with COVID-19. Although advanced age is the greatest risk factor for COVID-19 severity, published data on the impact of SARS-CoV-2 infection on WAT in aged individuals are scarce. Here, we characterized the response of subcutaneous and visceral WAT depots to SARS-CoV-2 infection in young adult and aged golden hamsters. In both age groups, infection was associated with a decrease in adipocyte size in the two WAT depots; this effect was partly due to changes in tissue's lipid metabolism and persisted for longer in aged hamsters than in young-adult hamsters. In contrast, only the subcutaneous WAT depot contained crown-like structures (CLSs) in which dead adipocytes were surrounded by SARS-CoV-2-infected macrophages, some of them forming syncytial multinucleated cells. Importantly, older age predisposed to a unique manifestation of viral disease in the subcutaneous WAT depot during SARS-CoV-2 infection; the persistence of very large CLSs was indicative of an age-associated defect in the clearance of dead adipocytes by macrophages. Moreover, we uncovered age-related differences in plasma lipid profiles during SARS-CoV-2 infection. These data suggest that the WAT's abnormal response to SARS-CoV-2 infection may contribute to the greater severity of COVID-19 observed in elderly patients.

Beyond its Psychiatric Use: The Benefits of Low-dose Lithium Supplementation

Lithium is most well-known for its mood-stabilizing effects in the treatment of bipolar disorder. Due to its narrow therapeutic window (0.5-1.2 mM serum concentration), there is a stigma associated with lithium treatment and the adverse effects that can occur at therapeutic doses. However, several studies have indicated that doses of lithium under the predetermined therapeutic dose used in bipolar disorder treatment may have beneficial effects not only in the brain but across the body. Currently, literature shows that low-dose lithium (≤0.5 mM) may be beneficial for cardiovascular, musculoskeletal, metabolic, and cognitive function, as well as inflammatory and antioxidant processes of the aging body. There is also some evidence of low-dose lithium exerting a similar and sometimes synergistic effect on these systems. This review summarizes these findings with a focus on low-dose lithium's potential benefits on the aging process and age-related diseases of these systems, such as cardiovascular disease, osteoporosis, sarcopenia, obesity and type 2 diabetes, Alzheimer's disease, and the chronic low-grade inflammatory state known as inflammaging. Although lithium's actions have been widely studied in the brain, the study of the potential benefits of lithium, particularly at a low dose, is still relatively novel. Therefore, this review aims to provide possible mechanistic insights for future research in this field.

Adipose tissue aging is regulated by an altered immune system

Adipose tissue is a widely distributed organ that plays a critical role in age-related physiological dysfunctions as an important source of chronic sterile low-grade inflammation. Adipose tissue undergoes diverse changes during aging, including fat depot redistribution, brown and beige fat decrease, functional decline of adipose progenitor and stem cells, senescent cell accumulation, and immune cell dysregulation. Specifically, inflammaging is common in aged adipose tissue. Adipose tissue inflammaging reduces adipose plasticity and pathologically contributes to adipocyte hypertrophy, fibrosis, and ultimately, adipose tissue dysfunction. Adipose tissue inflammaging also contributes to age-related diseases, such as diabetes, cardiovascular disease and cancer. There is an increased infiltration of immune cells into adipose tissue, and these infiltrating immune cells secrete proinflammatory cytokines and chemokines. Several important molecular and signaling pathways mediate the process, including JAK/STAT, NFκB and JNK, etc. The roles of immune cells in aging adipose tissue are complex, and the underlying mechanisms remain largely unclear. In this review, we summarize the consequences and causes of inflammaging in adipose tissue. We further outline the cellular/molecular mechanisms of adipose tissue inflammaging and propose potential therapeutic targets to alleviate age-related problems.

The "Iron Tale"- iron indices and handgrip strength in community-dwelling adults

Sarcopenia is a precursor for physical frailty and is associated with adverse outcomes. Low handgrip strength (HGS) is one of the diagnostic criteria for sarcopenia. Multiple factors can influence muscle quality, including muscle composition, architecture, fat infiltration, fibrosis, excessive iron deposition, and neural activation. There is limited evidence on the association of iron and HGS in community-dwelling older adults. We aim to examine the association of HGS with iron indices and inflammation. The Healthy Older People Everyday study is a subset of the Singapore Population Health Studies cohort. Complete cross-sectional data and iron indices were available for 477 participants. Sociodemographics, comorbidities, and final scores of the FRAIL scale, Barthel Index, Lawton Scale, HGS, and timed-up-and-go were collected and analyzed. Laboratory parameters including hemoglobin, hsCRP and iron indices were measured. The mean age of the participants was 70.9 ± 5.0 years, 258(54.1%) were females, and most were of Chinese(85.3%) ethnicity. Amongst the participants, 6.9% were frail, 39.4% were pre-frailt, and 53.7% were robust. Mean HGS was 22.2 ± 7.0 kg. Low HGS was prevalent in 47.8%, the highest amongst Indians. Prevalence of diabetes, chronic kidney disease, and ischaemic heart disease were significantly higher in those with low HGS. In multivariate regression adjusting for age, sex, comorbidities and Hb, ferritin (β = 0.004 95%CI 0.0002-0.007, p = 0.04), transferrin saturation (β = 0.06 95%CI 0.01-0.10, p = 0.02) and hsCRP (β = - 0.15 95%CI - 0.26 to - 0.04, p < 0.01) were significantly associated with HGS. CRP was negatively associated with HGS, whereas ferritin and transferrin saturation were positively associated with HGS. Older people with iron deficiency should be assessed for sarcopenia, and vice versa, as both can occur in multisystemic disorder, and need to be managed concurrently. Prospective longitudinal studies and clinical trials may be required to establish the causal effect of iron deficiency on muscle strength and sarcopenia and the benefits of iron therapy to improve function and quality of life.

Different Effects of Low Selenite and Selenium-Nanoparticle Supplementation on Adipose Tissue Function and Insulin Secretion in Adolescent Male Rats

Adolescence is a period of intense growth and endocrine changes, and obesity and insulin-resistance processes during this period have lately been rising. Selenium (Se) homeostasis is related to lipid metabolism depending on the form and dose of Se. This study tests the actions of low-dose selenite and Se nanoparticles (SeNPs) on white (WAT) and brown adipose tissue (BAT) deposition, insulin secretion, and GPx1, IRS-1 and FOXO3a expression in the WAT of adolescent rats as regards oxidative stress, adipocyte length and adipokine secretion. Four groups of male adolescent rats were treated: control (C), low selenite supplementation (S), low SeNP supplementation (NS) and moderate SeNP supplementation (NSS). Supplementation was received orally through water intake; NS and NSS rats received two- and tenfold more Se than C animals, respectively. SeNPs were obtained by reducing Se tetrachloride in the presence of ascorbic acid. For the first time in vivo, it was demonstrated that low selenite supplementation contributed to increased adipogenesis via the insulin signaling pathway and LCN2 modulation, while low SeNP administration prevented fat depots in WAT via the decrease in insulin signaling and FOXO3a autophagy in WAT, lowering inflammation. These effects were independent of GPx1 expression or activity in WAT. These findings provide data for dietary approaches to prevent obesity and/or anorexia during adolescence. These findings may be relevant to future studies looking at a nutritional approach aimed at pre-venting obesity and/or anorexia in adolescence.

Age- and sex-specific effects of a long-term lifestyle intervention on body weight and cardiometabolic health markers in adults with prediabetes: results from the diabetes prevention study PREVIEW

AIMS/HYPOTHESIS

Lifestyle interventions are the first-line treatment option for body weight and cardiometabolic health management. However, whether age groups or women and men respond differently to lifestyle interventions is under debate. We aimed to examine age- and sex-specific effects of a low-energy diet (LED) followed by a long-term lifestyle intervention on body weight, body composition and cardiometabolic health markers in adults with prediabetes (i.e. impaired fasting glucose and/or impaired glucose tolerance).

METHODS

This observational study used longitudinal data from 2223 overweight participants with prediabetes in the multicentre diabetes prevention study PREVIEW. The participants underwent a LED-induced rapid weight loss (WL) period followed by a 3 year lifestyle-based weight maintenance (WM) intervention. Changes in outcomes of interest in prespecified age (younger: 25-45 years; middle-aged: 46-54 years; older: 55-70 years) or sex (women and men) groups were compared.

RESULTS

In total, 783 younger, 319 middle-aged and 1121 older adults and 1503 women and 720 men were included in the analysis. In the available case and complete case analyses, multivariable-adjusted linear mixed models showed that younger and older adults had similar weight loss after the LED, whereas older adults had greater sustained weight loss after the WM intervention (adjusted difference for older vs younger adults -1.25% [95% CI -1.92, -0.58], p<0.001). After the WM intervention, older adults lost more fat-free mass and bone mass and had smaller improvements in 2 h plasma glucose (adjusted difference for older vs younger adults 0.65 mmol/l [95% CI 0.50, 0.80], p<0.001) and systolic blood pressure (adjusted difference for older vs younger adults 2.57 mmHg [95% CI 1.37, 3.77], p<0.001) than younger adults. Older adults had smaller decreases in fasting and 2 h glucose, HbA1c and systolic blood pressure after the WM intervention than middle-aged adults. In the complete case analysis, the above-mentioned differences between middle-aged and older adults disappeared, but the direction of the effect size did not change. After the WL period, compared with men, women had less weight loss (adjusted difference for women vs men 1.78% [95% CI 1.12, 2.43], p<0.001) with greater fat-free mass and bone mass loss and smaller improvements in HbA1c, LDL-cholesterol and diastolic blood pressure. After the WM intervention, women had greater fat-free mass and bone mass loss and smaller improvements in HbA1c and LDL-cholesterol, while they had greater improvements in fasting glucose, triacylglycerol (adjusted difference for women vs men -0.08 mmol/l [-0.11, -0.04], p<0.001) and HDL-cholesterol.

CONCLUSIONS/INTERPRETATION

Older adults benefited less from a lifestyle intervention in relation to body composition and cardiometabolic health markers than younger adults, despite greater sustained weight loss. Women benefited less from a LED followed by a lifestyle intervention in relation to body weight and body composition than men. Future interventions targeting older adults or women should take prevention of fat-free mass and bone mass loss into consideration.

CLINICAL TRIAL REGISTRATION NUMBER

ClinicalTrials.gov NCT01777893.

Adipose Tissue Aging and Metabolic Disorder, and the Impact of Nutritional Interventions

Adipose tissue is the largest and most active endocrine organ, involved in regulating energy balance, glucose and lipid homeostasis and immune function. Adipose tissue aging processes are associated with brown adipose tissue whitening, white adipose tissue redistribution and ectopic deposition, resulting in an increase in age-related inflammatory factors, which then trigger a variety of metabolic syndromes, including diabetes and hyperlipidemia. Metabolic syndrome, in turn, is associated with increased inflammatory factors, all-cause mortality and cognitive impairment. There is a growing interest in the role of nutritional interventions in adipose tissue aging. Nowadays, research has confirmed that nutritional interventions, involving caloric restriction and the use of vitamins, resveratrol and other active substances, are effective in managing adipose tissue aging’s adverse effects, such as obesity. In this review we summarized age-related physiological characteristics of adipose tissue, and focused on what nutritional interventions can do in improving the retrogradation and how they do this.

Sarcopenia, Obesity, Sarcopenic Obesity and Risk of Poor Nutritional Status in Polish Community-Dwelling Older People Aged 60 Years and Over

Poor nutritional status (PNS) is a modifiable factor determining abnormalities in body composition-sarcopenia, obesity, and sarcopenic obesity (SO). We aimed to assess the prevalence of these conditions and their association with PNS in 211 community-dwelling older adults. Sarcopenia was diagnosed based on the European Working Group on Sarcopenia in Older People 2 (EWGSOP2) recommendations. Obesity was diagnosed with the Percent Body Fat (>42% in women and >30% in men). Subjects fulfilling the criteria for obesity and concomitantly with reduced lower and/or upper limbs muscle strength and muscle mass (ALM/BMI < 0.512 in women and <0.789 in men) were classified as SO phenotype. Participants without obesity and sarcopenia were categorized as ‘normal’ phenotype. Nutritional status was estimated with the Mini Nutritional Assessment, and a score of <24 indicated PNS. In total, 49.8% participants had abnormal body composition (60.7% men and 42.5% women; p = 0.001). Sarcopenia, obesity, and SO were diagnosed in 10%, 32.7%, and 7.1% of subjects. PNS was found in 31.3% of the study sample. Its prevalence differed between phenotypes: 81% in sarcopenia, 60% in SO, 14.5% in obesity, and 28.3% in the ‘normal’ phenotype group (p = 0.000). Based on the results, abnormal body composition is prevalent in elderly subjects. Sarcopenia and SO are often associated with PNS.

Immunosenescence in Childhood Cancer Survivors and in Elderly: A Comparison and Implication for Risk Stratification

The population of childhood cancer survivors (CCS) has grown rapidly in recent decades. Although cured of their original malignancy, these individuals are at increased risk of serious late effects, including age-associated complications. An impaired immune system has been linked to the emergence of these conditions in the elderly and CCS, likely due to senescent immune cell phenotypes accompanied by low-grade inflammation, which in the elderly is known as "inflammaging." Whether these observations in the elderly and CCS are underpinned by similar mechanisms is unclear. If so, existing knowledge on immunosenescent phenotypes and inflammaging might potentially serve to benefit CCS. We summarize recent findings on the immune changes in CCS and the elderly, and highlight the similarities and identify areas for future research. Improving our understanding of the underlying mechanisms and immunosenescent markers of accelerated immune aging might help us to identify individuals at increased risk of serious health complications.

p38α Deficiency in T Cells Ameliorates Diet-Induced Obesity, Insulin Resistance, and Adipose Tissue Senescence

Adipose tissue-resident T cells play vital roles in regulating inflammation and metabolism in obesity, but the underlying mechanisms remain unclear. Here, we show that high-fat diet (HFD) feeding enhances p38 activity in adipose-resident T cells. T cell-specific deletion of p38α, an essential subunit of p38 expressed in most immune cells, protected mice from HFD-induced obesity, hepatic steatosis, adipose tissue inflammation, and insulin resistance. Mice with p38α deletion in T cells exhibited higher energy expenditure. Mechanistically, p38α promoted T-cell glycolysis through mechanistic target of rapamycin signaling, leading to enhanced Th1 differentiation. Accordingly, genetic deletion of p38α alleviated ongoing diet-induced obesity. Unexpectedly, p38α signaling in T cells promoted adipose tissue senescence during obesity and aging. Taken together, our results identify p38α in T cells as an essential regulator of obesity, insulin resistance, and adipose tissue senescence, and p38α may be a therapeutic target for obese- or aging-associated diseases.

Perinatal Obesity Induces Hepatic Growth Restriction with Increased DNA Damage Response, Senescence, and Dysregulated Igf-1-Akt-Foxo1 Signaling in Male Offspring of Obese Mice

Maternal obesity predisposes for hepato-metabolic disorders early in life. However, the underlying mechanisms causing early onset dysfunction of the liver and metabolism remain elusive. Since obesity is associated with subacute chronic inflammation and accelerated aging, we test the hypothesis whether maternal obesity induces aging processes in the developing liver and determines thereby hepatic growth. To this end, maternal obesity was induced with high-fat diet (HFD) in C57BL/6N mice and male offspring were studied at the end of the lactation [postnatal day 21 (P21)]. Maternal obesity induced an obese body composition with metabolic inflammation and a marked hepatic growth restriction in the male offspring at P21. Proteomic and molecular analyses revealed three interrelated mechanisms that might account for the impaired hepatic growth pattern, indicating prematurely induced aging processes: (1) Increased DNA damage response (γH2AX), (2) significant upregulation of hepatocellular senescence markers (Cdnk1a, Cdkn2a); and (3) inhibition of hepatic insulin/insulin-like growth factor (IGF)-1-AKT-p38-FoxO1 signaling with an insufficient proliferative growth response. In conclusion, our murine data demonstrate that perinatal obesity induces an obese body composition in male offspring with hepatic growth restriction through a possible premature hepatic aging that is indicated by a pathologic sequence of inflammation, DNA damage, senescence, and signs of a possibly insufficient regenerative capacity.

In vivo cyclic induction of the FOXM1 transcription factor delays natural and progeroid aging phenotypes and extends healthspan

The FOXM1 transcription factor exhibits pleiotropic C-terminal transcriptional and N-terminal non-transcriptional functions in various biological processes critical for cellular homeostasis. We previously found that FOXM1 repression during cellular aging underlies the senescence phenotypes, which were vastly restored by overexpressing transcriptionally active FOXM1. Yet, it remains unknown whether increased expression of FOXM1 can delay organismal aging. Here, we show that in vivo cyclic induction of an N-terminal truncated FOXM1 transgene on progeroid and naturally aged mice offsets aging-associated repression of full-length endogenous Foxm1, reinstating both transcriptional and non-transcriptional functions. This translated into mitigation of several cellular aging hallmarks, as well as molecular and histopathological progeroid features of the short-lived Hutchison-Gilford progeria mouse model, significantly extending its lifespan. FOXM1 transgene induction also reinstated endogenous Foxm1 levels in naturally aged mice, delaying aging phenotypes while extending their lifespan. Thus, we disclose that FOXM1 genetic rewiring can delay senescence-associated progeroid and natural aging pathologies.

Accumulation of γδ T cells in visceral fat with aging promotes chronic inflammation

Adipose tissue dysfunction is strongly linked to the development of chronic inflammation and cardiometabolic disorders in aging. While much attention has been given to the role of resident adipose tissue immune cells in the disruption of homeostasis in obesity, age-specific effects remain understudied. Here, we identified and characterized a population of γδ T cells, which show unique age-dependent accumulation in the visceral adipose tissue (VAT) of both mice and humans. Diet-induced obesity likewise increased γδ T cell numbers; however, the effect was greater in the aged where the increase was independent of fat mass. γδ T cells in VAT express a tissue-resident memory T cell phenotype (CD44^hiCD62L^lowCD69⁺) and are predominantly IL-17A-producing cells. Transcriptome analyses of immunomagnetically purified γδ T cells identified significant age-associated differences in expression of genes related to inflammation, immune cell composition, and adipocyte differentiation, suggesting age-dependent qualitative changes in addition to the quantitative increase. Genetic deficiency of γδ T cells in old age improved the metabolic phenotype, characterized by increased respiratory exchange ratio, and lowered levels of IL-6 both systemically and locally in VAT. Decreased IL-6 was predominantly due to reduced production by non-immune stromal cells, primarily preadipocytes, and adipose-derived stem cells. Collectively, these findings suggest that an age-dependent increase of tissue-resident γδ T cells in VAT contributes to local and systemic chronic inflammation and metabolic dysfunction in aging.

Long-Chain Polyunsaturated Fatty Acids and Their Metabolites Regulate Inflammation in Age-Related Macular Degeneration

Age-related macular degeneration (AMD) is a blinding eye disease, whose incidence strongly increases with ages. The etiology of AMD is complex, including aging, abnormal lipid metabolism, chronic inflammation and oxidative stress. Long-chain polyunsaturated fatty acids (LCPUFA) are essential for ocular structures and functions. This review summarizes the regulatory effects of LCPUFA on inflammation in AMD. LCPUFA are related to aging, autophagy and chronic inflammation. They are metabolized to pro- and anti-inflammatory metabolites by various enzymes. These metabolites stimulate inflammation in response to oxidative stress, causing innate and acquired immune responses. This review also discusses the possible clinical applications, which provided novel targets for the prevention and treatment of AMD and other age-related diseases.

Myeloid cell TBK1 restricts inflammatory responses

Proinflammatory cytokine production by innate immune cells plays a crucial role in inflammatory diseases, but the molecular mechanisms controlling the inflammatory responses are poorly understood. Here, we show that TANK-binding kinase 1 (TBK1) serves as a vital regulator of proinflammatory macrophage function and protects against tissue inflammation. Myeloid cell-conditional Tbk1 knockout (MKO) mice spontaneously developed adipose hypertrophy and metabolic disorders at old ages, associated with increased adipose tissue M1 macrophage infiltration and proinflammatory cytokine expression. When fed with a high-fat diet, the Tbk1-MKO mice also displayed exacerbated hepatic inflammation and insulin resistance, developing symptoms of nonalcoholic steatohepatitis. Furthermore, myeloid cell-specific TBK1 ablation exacerbates inflammation in experimental colitis. Mechanistically, TBK1 functions in macrophages to suppress the NF-κB and MAP kinase signaling pathways and thus attenuate induction of proinflammatory cytokines, particularly IL-1β. Ablation of IL-1 receptor 1 (IL-1R1) eliminates the inflammatory symptoms of Tbk1-MKO mice. These results establish TBK1 as a pivotal anti-inflammatory mediator that restricts inflammation in different disease models.

Adipose tissue macrophages in aging-associated adipose tissue function

"Inflammaging" refers to the chronic, low-grade inflammation that characterizes aging. Aging, like obesity, is associated with visceral adiposity and insulin resistance. Adipose tissue macrophages (ATMs) have played a major role in obesity-associated inflammation and insulin resistance. Macrophages are elevated in adipose tissue in aging. However, the changes and also possibly functions of ATMs in aging and aging-related diseases are unclear. In this review, we will summarize recent advances in research on the role of adipose tissue macrophages with aging-associated insulin resistance and discuss their potential therapeutic targets for preventing and treating aging and aging-related diseases.

Regulation of p27 and Cdk2 Expression in Different Adipose Tissue Depots in Aging and Obesity

Aging usually comes associated with increased visceral fat accumulation, reaching even an obesity state, and favoring its associated comorbidities. One of the processes involved in aging is cellular senescence, which is highly dependent on the activity of the regulators of the cell cycle. The aim of this study was to analyze the changes in the expression of p27 and cdk2 in different adipose tissue depots during aging, as well as their regulation by obesity in mice. Changes in the expression of p27 and CDK2 in visceral and subcutaneous white adipose tissue (WAT) biopsies were also analyzed in a human cohort of obesity and type 2 diabetes. p27, but not cdk2, exhibits a lower expression in subcutaneous than in visceral WAT in mice and humans. p27 is drastically downregulated by aging in subcutaneous WAT (scWAT), but not in gonadal WAT, of female mice. Obesity upregulates p27 and cdk2 expression in scWAT, but not in other fat depots of aged mice. In humans, a significant upregulation of p27 was observed in visceral WAT of subjects with obesity. Taken together, these results show a differential adipose depot-dependent regulation of p27 and cdk2 in aging and obesity, suggesting that p27 and cdk2 could contribute to the adipose-tissue depot’s metabolic differences. Further studies are necessary to fully corroborate this hypothesis.

Influence of dietary patterns on the metabolically healthy obesity phenotype: A systematic review

AIMS

In many individuals (35%) obesity is not accompanied by cardiometabolic disorders, a condition referred to as metabolically healthy obesity. Since the effectiveness of dietary interventions for this condition is not well established, this study reviews the influence of dietary patterns on the phenotype of metabolically healthy obesity in adults and elderly.

DATA SYNTHESIS

The review was carried out following the PRISMA guidelines and registered in the PROSPERO. The search was conducted in the MEDLINE, SCOPUS, Web of Science, Science Direct, LILACS, and SciELO databases. A total of 236 articles were identified, seven of which were selected for synthesis after application of the eligibility criteria.

CONCLUSIONS

The overall result found out in this synthesis was that the greater adherence to healthy eating patterns was considered a preventive to the transition from metabolically healthy obesity to metabolic unhealthy obese phenotypes, by improving metabolic health, and reducing the risk of cardiovascular disease and mortality from all causes. In contrast, unhealthy eating patterns resulted in increased inflammation and risks of developing noncommunicable diseases. This review indicates that adherence to healthy eating patterns may interfere with metabolic phenotypes of obesity and positively affect metabolically healthy obesity.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration number CRD42020159783.

White adipose tissue dysfunction in obesity and aging

Both obesity and aging are associated with the development of metabolic diseases such as type 2 diabetes and cardiovascular disease. Chronic low-grade inflammation of adipose tissue is one of the mechanisms implicated in the progression of these diseases. Obesity and aging trigger adipose tissue alterations that ultimately lead to a pro-inflammatory phenotype of the adipose tissue-resident immune cells. Obesity and aging also share other features such as a higher visceral vs. subcutaneous adipose tissue ratio and a decreased lifespan. Here, we review the common characteristics of obesity and aging and the alterations in white adipose tissue and resident immune cells. We focus on the adipose tissue metabolic derangements in obesity and aging such as inflammation and adipose tissue remodeling.

The old guard: Age-related changes in microglia and their consequences

Among all major organs, the brain is one of the most susceptible to the inexorable effects of aging. Throughout the last decades, several studies in human cohorts and animal models have revealed a plethora of age-related changes in the brain, including reduced neurogenesis, oxidative damage, mitochondrial dysfunction and cell senescence. As the main immune effectors and first responders of the nervous tissue, microglia are at the center of these events. These cells experience irrevocable changes as a result from cumulative exposure to environmental triggers, such as stress, infection and metabolic dysregulation. The age-related immunosenescent phenotype acquired by microglia is characterized by profound modifications in their transcriptomic profile, secretome, morphology and phagocytic activity, which compromise both their housekeeping and defensive functions. As a result, aged microglia are no longer capable of establishing effective immune responses and sustaining normal synaptic activity, directly contributing to age-associated cognitive decline and neurodegeneration. This review discusses how lifestyle and environmental factors drive microglia dysfunction at the molecular and functional level, also highlighting possible interventions to reverse aging-associated damage to the nervous and immune systems.

Phenotypic Changes in T Cell and Macrophage Subtypes in Perivascular Adipose Tissues Precede High-Fat Diet-Induced Hypertension

Perivascular adipose tissue (PVAT) may connect adiposity to hypertension because of its vasoactive functions and proximity to blood vessels. We hypothesized that immune cell changes in PVATs precede the development of high fat diet (HFD)-induced hypertension. Both sexes of Dahl S rat become equally hypertensive when fed a HFD. Further, both sexes would have similar immune cell composition in PVATs with the development and progression of hypertension. Male and female Dahl S rats were fed a regular (10% calories from fat; CD) diet or a HFD (60%) from weaning. PVATs from around the thoracic aorta (APVAT) and small mesenteric vessels (MRPVAT) were harvested at 10 weeks (pre-hypertensive), 17 weeks (onset), or 24 (hypertensive) weeks on diet. RNA-sequencing in MRPVAT at 24 weeks indicated sex-differences with HFD (>CD) and diet-differences in males (>females). The top 2 out of 7 immune processes with the maximum number of differentially expressed genes (DEGs) were associated with immune effector processes and leukocyte activation. Macrophages and T cells (and their activation status), neutrophils, mast, B and NK cells were measured by flow cytometry. Sex-specific changes in the number of CD4 memory T cells (males > females) and M2-like macrophages (females > males) in PVATs occur with a HFD before hypertension developed. Sex-differences became more prominent with the development and progression of hypertension, driven by the diet (HFD > CD). These findings suggest that though the magnitudes of increased blood pressure were equivalent in both sexes, the associated phenotypic changes in the immune subsets within the PVATs were different in the male vs. the female with the development and progression of hypertension.

Visceral adiposity index and its association with Dietary Approaches to Stop Hypertension (DASH) diet scores among older adults: National Health and Nutrition Examination Surveys 2011-2014

BACKGROUND & AIMS

The visceral adiposity index (VAI) has been shown to be a reliable estimate of visceral adiposity, but little is known about its association with specific dietary patterns such as the Dietary Approaches to Stop Hypertension (DASH) diet, particularly in older adults. Many studies have shown the DASH diet to be beneficial for cardiometabolic health. The purpose of this study was to investigate the relationship between DASH diet scores and the VAI in older adults using a nationally representative dataset.

METHODS

Using the National Health and Nutrition Examination Surveys (NHANES) from 2011 to 2014, data from 508 community-dwelling older adults were examined, and dietary intake was evaluated using the Dixon's DASH diet index. Using multiple linear regression analysis, the relationship between VAI and DASH diet score was assessed while controlling for demographic variables.

RESULTS

Participants' average DASH diet score was 2.41 (SE = 0.07), and the average VAI was 1.55 (SE = 0.08). The results suggest a significant inverse relationship between the DASH diet and VAI (β = -0.19, t = -2.73, p = 0.009).

CONCLUSIONS

Results of this study suggest that protective properties of the DASH diet pattern may be due in part to its inverse relationship with visceral adiposity. This information supports practitioners' use of the VAI with older adults in addition to providing nutrition counseling with the DASH diet to reduce patients' cardiometabolic risk.

Nutritional Orthopedics and Space Nutrition as Two Sides of the Same Coin: A Scoping Review

Since the Moon landing, nutritional research has been charged with the task of guaranteeing human health in space. In addition, nutrition applied to Orthopedics has developed in recent years, driven by the need to improve the efficiency of the treatment path by enhancing the recovery after surgery. As a result, nutritional sciences have specialized into two distinct fields of research: Nutritional Orthopedics and Space Nutrition. The former primarily deals with the nutritional requirements of old patients in hospitals, whereas the latter focuses on the varied food challenges of space travelers heading to deep space. Although they may seem disconnected, they both investigate similar nutritional issues. This scoping review shows what these two disciplines have in common, highlighting the mutual features between (1) pre-operative vs. pre-launch nutritional programs, (2) hospital-based vs. space station nutritional issues, and (3) post-discharge vs. deep space nutritional resilience. PubMed and Google Scholar were used to collect documents published from 1950 to 2020, from which 44 references were selected on Nutritional Orthopedics and 44 on Space Nutrition. Both the orthopedic patient and the astronaut were found to suffer from food insecurity, malnutrition, musculoskeletal involution, flavor/pleasure issues, fluid shifts, metabolic stresses, and isolation/confinement. Both fields of research aid the planning of demand-driven food systems and advanced nutritional approaches, like tailored diets with nutrients of interest (e.g., vitamin D and calcium). The nutritional features of orthopedic patients on Earth and of astronauts in space are undeniably related. Consequently, it is important to initiate close collaborations between orthopedic nutritionists and space experts, with the musculoskeletal-related dedications playing as common fuel.

Exercise reduces metabolic burden while altering the immune system in aged mice

Although several evidence has suggested the impact of exercise on the prevention of aging phenotypes, few studies have been conducted on the mechanism by which exercise alters the immune-cell profile, thereby improving metabolism in senile obesity. In this study, we confirmed that 4-week treadmill exercise sufficiently improved metabolic function, including increased lean mass and decreased fat mass, in 88-week-old mice. The expression level of the senescence marker p16 in the white adipose tissue (WAT) was decreased after 4-weeks of exercise. Exercise induced changes in the profiles of immune-cell subsets, including natural killer (NK) cells, central memory CD8⁺ T cells, eosinophils, and neutrophils, in the stromal vascular fraction of WAT. In addition, it has been shown through transcriptome analysis of WAT that exercise can activate pathways involved in the interaction between WAT and immune cells, in particular NK cells, in aged mice. These results suggest that exercise has a profound effect on changes in immune-cell distribution and senescent-cell scavenging in WAT of aged mice, eventually affecting overall energy metabolism toward a more youthful state.

International Exercise Recommendations in Older Adults (ICFSR): Expert Consensus Guidelines

The human ageing process is universal, ubiquitous and inevitable. Every physiological function is being continuously diminished. There is a range between two distinct phenotypes of ageing, shaped by patterns of living - experiences and behaviours, and in particular by the presence or absence of physical activity (PA) and structured exercise (i.e., a sedentary lifestyle). Ageing and a sedentary lifestyle are associated with declines in muscle function and cardiorespiratory fitness, resulting in an impaired capacity to perform daily activities and maintain independent functioning. However, in the presence of adequate exercise/PA these changes in muscular and aerobic capacity with age are substantially attenuated. Additionally, both structured exercise and overall PA play important roles as preventive strategies for many chronic diseases, including cardiovascular disease, stroke, diabetes, osteoporosis, and obesity; improvement of mobility, mental health, and quality of life; and reduction in mortality, among other benefits. Notably, exercise intervention programmes improve the hallmarks of frailty (low body mass, strength, mobility, PA level, energy) and cognition, thus optimising functional capacity during ageing. In these pathological conditions exercise is used as a therapeutic agent and follows the precepts of identifying the cause of a disease and then using an agent in an evidence-based dose to eliminate or moderate the disease. Prescription of PA/structured exercise should therefore be based on the intended outcome (e.g., primary prevention, improvement in fitness or functional status or disease treatment), and individualised, adjusted and controlled like any other medical treatment. In addition, in line with other therapeutic agents, exercise shows a dose-response effect and can be individualised using different modalities, volumes and/or intensities as appropriate to the health state or medical condition. Importantly, exercise therapy is often directed at several physiological systems simultaneously, rather than targeted to a single outcome as is generally the case with pharmacological approaches to disease management. There are diseases for which exercise is an alternative to pharmacological treatment (such as depression), thus contributing to the goal of deprescribing of potentially inappropriate medications (PIMS). There are other conditions where no effective drug therapy is currently available (such as sarcopenia or dementia), where it may serve a primary role in prevention and treatment. Therefore, this consensus statement provides an evidence-based rationale for using exercise and PA for health promotion and disease prevention and treatment in older adults. Exercise prescription is discussed in terms of the specific modalities and doses that have been studied in randomised controlled trials for their effectiveness in attenuating physiological changes of ageing, disease prevention, and/or improvement of older adults with chronic disease and disability. Recommendations are proposed to bridge gaps in the current literature and to optimise the use of exercise/PA both as a preventative medicine and as a therapeutic agent.

Aging of Bone Marrow Mesenchymal Stromal Cells: Hematopoiesis Disturbances and Potential Role in the Development of Hematologic Cancers

Simple Summary

As for many other cancers, the risk of developing hematologic malignancies increases considerably as people age. In recent years, a growing number of studies have highlighted the influence of the aging microenvironment on hematopoiesis and tumor progression. Mesenchymal stromal cells are a major player in intercellular communication inside the bone marrow microenvironment involved in hematopoiesis support. With aging, their functions may be altered, leading to hematopoiesis disturbances which can lead to hematologic cancers. A good understanding of the mechanisms involved in mesenchymal stem cell aging and the consequences on hematopoiesis and tumor progression is therefore necessary for a better comprehension of hematologic malignancies and for the development of therapeutic approaches.

Abstract

Aging of bone marrow is a complex process that is involved in the development of many diseases, including hematologic cancers. The results obtained in this field of research, year after year, underline the important role of cross-talk between hematopoietic stem cells and their close environment. In bone marrow, mesenchymal stromal cells (MSCs) are a major player in cell-to-cell communication, presenting a wide range of functionalities, sometimes opposite, depending on the environmental conditions. Although these cells are actively studied for their therapeutic properties, their role in tumor progression remains unclear. One of the reasons for this is that the aging of MSCs has a direct impact on their behavior and on hematopoiesis. In addition, tumor progression is accompanied by dynamic remodeling of the bone marrow niche that may interfere with MSC functions. The present review presents the main features of MSC senescence in bone marrow and their implications in hematologic cancer progression.

GHR-/- Mice are protected from obesity-related white adipose tissue inflammation

Growth hormone (GH) excess in bovine (b)GH transgenic mice has been shown to alter white adipose tissue (WAT) immune cell populations. The present study aimed to evaluate the effects of GH resistance on WAT immune cell populations using GH receptor knockout (GHR^-/- ) mice. Eight- and 24-month-old, male GHR^-/- and wild-type mice were used. Body composition and tissue weights were determined, and systemic inflammation was assessed by measuring serum cytokine levels. The stromal vascular fraction (SVF) was isolated from three distinct WAT depots, and immune cell populations were quantified using flow cytometry. GHR^-/- mice at both ages had decreased body weight but were obese. Although no significant changes were observed in serum levels of the measured cytokines, SVF cell alterations were seen and differed from depot to depot. Total SVF cells were decreased in epidydimal (Epi) depots, whereas SVF cells per gram adipose tissue weight were increased in mesenteric (Mes) depots of GHR^-/- mice relative to controls. T cells and T helper cells were increased in Mes at 8 months old, whereas cytotoxic T cells were decreased in subcutaneous (SubQ) at 24 months old. Other cells were unchanged at both ages measured. The present study demonstrates that removal of GH action results in modest and depot-specific changes to several immune cell populations in WAT of intra-abdominal depots (Epi and Mes), which are somewhat surprising results because the SubQ has the largest change in size, whereas the Mes has no size change. Taken together with previous results from bovine GH transgenic mice, these data suggest that GH induces changes in the immune cell population of WAT in a depot-specific manner. Notably, GHR^-/- mice appear to be protected from age-related WAT inflammation and immune cell infiltration despite obesity.

Molecular basis of ageing in chronic metabolic diseases

AIM

Over the last decades, the shift in age distribution towards older ages and the progressive ageing which has occurred in most populations have been paralleled by a global epidemic of obesity and its related metabolic disorders, primarily, type 2 diabetes (T2D). Dysfunction of the adipose tissue (AT) is widely recognized as a significant hallmark of the ageing process that, in turn, results in systemic metabolic alterations. These include insulin resistance, accumulation of ectopic lipids and chronic inflammation, which are responsible for an elevated risk of obesity and T2D onset associated to ageing. On the other hand, obesity and T2D, the paradigms of AT dysfunction, share many physiological characteristics with the ageing process, such as an increased burden of senescent cells and epigenetic alterations. Thus, these chronic metabolic disorders may represent a state of accelerated ageing.

MATERIALS AND METHODS

A more precise explanation of the fundamental ageing mechanisms that occur in AT and a deeper understanding of their role in the interplay between accelerated ageing and AT dysfunction can be a fundamental leap towards novel therapies that address the causes, not just the symptoms, of obesity and T2D, utilizing strategies that target either senescent cells or DNA methylation.

RESULTS

In this review, we summarize the current knowledge of the pathways that lead to AT dysfunction in the chronological ageing process as well as the pathophysiology of obesity and T2D, emphasizing the critical role of cellular senescence and DNA methylation.

CONCLUSION

Finally, we highlight the need for further research focused on targeting these mechanisms.

Both ghrelin deletion and unacylated ghrelin overexpression preserve muscles in aging mice

Sarcopenia, the decline in muscle mass and functionality during aging, might arise from age-associated endocrine dysfunction. Ghrelin is a hormone circulating in both acylated (AG) and unacylated (UnAG) forms with anti-atrophic activity on skeletal muscle. Here, we show that not only lifelong overexpression of UnAG (Tg) in mice, but also the deletion of ghrelin gene (Ghrl KO) attenuated the age-associated muscle atrophy and functionality decline, as well as systemic inflammation. Yet, the aging of Tg and Ghrl KO mice occurs with different dynamics: while old Tg mice seem to preserve the characteristics of young animals, Ghrl KO mice features deteriorate with aging. However, young Ghrl KO mice show more favorable traits compared to WT animals that result, on the whole, in better performances in aged Ghrl KO animals. Treatment with pharmacological doses of UnAG improved muscle performance in old mice without modifying the feeding behavior, body weight, and adipose tissue mass. The antiatrophic effect on muscle mass did not correlate with modifications of protein catabolism. However, UnAG treatment induced a strong shift towards oxidative metabolism in muscle. Altogether, these data confirmed and expanded some of the previously reported findings and advocate for the design of UnAG analogs to treat sarcopenia.

Inflammation and metabolism: the role of adiposity in sarcopenic obesity

Sarcopenic obesity is characterised by the double burden of diminished skeletal muscle mass and the presence of excess adiposity. From a mechanistic perspective, both obesity and sarcopenia are associated with sub-acute, chronic pro-inflammatory states that impede metabolic processes, disrupting adipose and skeletal functionality, which may potentiate disease. Recent evidence suggests that there is an important cross-talk between metabolism and inflammation, which has shifted focus upon metabolic-inflammation as a key emerging biological interaction. Dietary intake, physical activity and nutritional status are important environmental factors that may modulate metabolic-inflammation. This paradigm will be discussed within the context of sarcopenic obesity risk. There is a paucity of data in relation to the nature and the extent to which nutritional status affects metabolic-inflammation in sarcopenic obesity. Research suggests that there may be scope for the modulation of sarcopenic obesity with alterations in diet. The potential impact of increasing protein consumption and reconfiguration of dietary fat composition in human dietary interventions are evaluated. This review will explore emerging data with respect to if and how different dietary components may modulate metabolic-inflammation, particularly with respect to adiposity, within the context of sarcopenic obesity.