Caloric restriction, longevity and aging: Recent contributions from human and non-human primate studies

Intermittent fasting promotes rejuvenation of immunosenescent phenotypes in aged adipose tissue

The aging of white adipose tissue (WAT) involves senescence of adipose stem and progenitor cells (ASPCs) and dysregulation of immune cell populations, serving as a major driver of age-associated adipose dysfunction and metabolic diseases. Conversely, the elimination of senescent ASPCs is associated with improvements in overall health. Intermittent fasting (IF), a dietary intervention that incorporates periodic cycles of fasting and refeeding, has been reported to promote weight loss and fat mass reduction and improve glucose and insulin homeostasis in both murine and human studies. While previous studies have assessed the effects of IF on obesity-associated metabolic dysfunction, few studies have examined the aging-specific changes to ASPCs and immune cell populations in WAT. Here, we show that IF in 18-20-month-old mice reduced senescent phenotypes of ASPCs and restored their adipogenic potential. Intriguingly, IF-treated mice exhibited an increase in adipose eosinophils, which has been reported to be associated with improved WAT homeostasis and immunological fitness in aged mice. The observed cellular and metabolic changes suggest that IF may be a feasible lifestyle regimen to reduce cellular senescence which could result in attenuation of downstream aging-induced WAT dysfunction and metabolic diseases.

Oral Administration of Nacre Extract from Pearl Oyster Shells Has Anti-Aging Effects on Skin and Muscle, and Extends the Lifespan in SAMP8 Mice

Pearl oysters have been extensively utilized in pearl production; however, most pearl oyster shells are discarded as industrial waste. In a previous study, we demonstrated that the intraperitoneal administration of pearl oyster shell-derived nacre extract (NE) prevented d-galactose-induced brain and skin aging. In this study, we examined the anti-aging effects of orally administered NE in senescence-accelerated mice (SAMP8). Feeding SAMP8 mice NE prevented the development of aging-related characteristics, such as coarse and dull hair, which are commonly observed in aged mice. Additionally, the NE mitigated muscle aging in SAMP8 mice, such as a decline in grip strength. Histological analysis of skeletal muscle revealed that the NE suppressed the expression of aging markers, cyclin-dependent kinase inhibitor 2A (p16) and cyclin-dependent kinase inhibitor 1 (p21), and increased the expression of sirtuin1 and peroxisome proliferator-activated receptor gamma coactivator 1 (PGC1)- α, which are involved in muscle synthesis. These findings suggest that the oral administration of NE suppresses skeletal muscle aging. Moreover, NE administration suppressed skin aging, including a decline in water content. Interestingly, oral administration of NE significantly extended the lifespan of SAMP8 mice, suggesting that its effectiveness as an anti-aging agent of various tissues including skeletal muscle, skin, and adipose tissue.

Treatment of mice with maternal intermittent fasting to improve the fertilization rate and reproduction

Maternal intermittent fasting (MIF) can have significant effects on several tissue and organ systems of the body, but there is a lack of research on the effects on the reproductive system. So, the aim of our study was to analyze the effects of MIF on fertility. B6C3F1Crl (C57BL/6N × C3H/HeN) male and female mice were selected for the first part of the experiments and were analyzed for body weight and fat weight after administration of the MIF intervention, followed by analysis of sperm counts and activation and embryo numbers. Subsequently, two strains of mice, C57BL/6NCrl and BALB/cJRj, were selected and administered MIF to observe the presence or absence of vaginal plugs for the purposes of mating success, sperm and oocyte quality, pregnancy outcome, fertility status and in vitro fertilization (IVF). Our results showed a significant reduction in body weight and fat content in mice receiving MIF intervention in B6C3F1Crl mice. Comparing the reproduction of the two strains of mice. However, the number of litters was increased in all MIF interventions in C57BL/6NCrl, but not statistically significant. In BALB/cJRj, there was a significant increase in the number of pregnant females as well as litter size in the MIF treatment group, as well as vaginal plugs, and IVF. There was also an increase in sperm activation and embryo number and the MIF intervention significantly increased sperm count and activation. Our results suggest that MIF interventions may be beneficial for reproduction in mice.

Adiposity, immunity, and inflammation: interrelationships in health and disease: a report from 24th Annual Harvard Nutrition Obesity Symposium, June 2023

The rapidly evolving field of immunometabolism explores how changes in local immune environments may affect key metabolic and cellular processes, including that of adipose tissue. Importantly, these changes may contribute to low-grade systemic inflammation. In turn, chronic low-grade inflammation affecting adipose tissue may exacerbate the outcome of metabolic diseases. Novel advances in our understanding of immunometabolic processes may critically lead to interventions to reduce disease severity and progression. An important example in this regard relates to obesity, which has a multifaceted effect on immunity, activating the proinflammatory pathways such as the inflammasome and disrupting cellular homeostasis. This multifaceted effect of obesity can be investigated through study of downstream conditions using cellular and systemic investigative techniques. To further explore this field, the National Institutes of Health P30 Nutrition Obesity Research Center at Harvard, in partnership with Harvard Medical School, assembled experts to present at its 24th Annual Symposium entitled "Adiposity, Immunity, and Inflammation: Interrelationships in Health and Disease" on 7 June, 2023. This manuscript seeks to synthesize and present key findings from the symposium, highlighting new research and novel disease-specific advances in the field. Better understanding the interaction between metabolism and immunity offers promising preventative and treatment therapies for obesity-related immunometabolic diseases.

Effects of different maternal diets on adipose tissue inflammation and liver tissue oxidative stress in dams and their female offspring

Pregnancy and lactation are important stages of fetal development. Therefore, this study investigated how different maternal diets offered during gestation and lactation periods affect adipose tissue inflammation and liver tissue oxidative stress of dams and their female offspring. Female BALB/c albino mice (60 days old) were randomized into three groups receiving a standard (CONT), hypercaloric (HD), or restricted (RD) diet during the pregnancy. After birth, female offspring weaned at 21 days were divided into two groups that received a standard or restricted diet (CONT/CONT, CONT/RD, RD/CONT, RD/RD, HD/CONT, and HD/RD) until 100 days old. Histological, oxidative parameters and inflammatory infiltrate of dams' and offspring's liver and adipose tissue were evaluated. HD dams presented non-alcoholic steatohepatitis (NASH) diagnosis and an increase in tumor necrosis factor-alpha (TNF-α) concentrations when compared to the RD and CONT dams, indicating a pro-inflammatory state. High concentrations of malondialdehyde (MDA) formation and catalase (CAT) activity in HD when compared to the CONT in the liver. SOD activity decreased in RD mice compared to CONT, and the SOD/CAT ratio was decreased in the RD and HD in comparison to the CONT. The maternal diet leads to an increase in SOD in RD/RD compared to HD/RD. RD-fed dams showed an increase in inflammatory infiltrates compared to CONT, evidencing changes caused by a restrictive diet. In the HD/CONT offspring, we verified an increase in inflammatory infiltrates in relation to the offspring fed a standard diet. In conclusion, HD, and RD, during pregnancy and lactation, altered the liver and adipose tissues of mothers. Furthermore, the maternal diet negatively impacts the offspring's adipose tissue but does not cause liver damage in these animals in adult life.

Revisiting the mechanisms linking blood glucose to cognitive impairment: new evidence for the potential important role of klotho

Background

The association between blood glucose and cognition is controversial. Klotho is an anti-aging protein with neural protective effects. This study aimed to use a population-based study to disentangle the relationship between blood glucose levels and cognitive function in older adults, and to explore the role of klotho in it.

Methods

A total of 1445 eligible participants from National Health and Nutrition Examination Survey (NHANES) 2011-2014 were included in our study. Cognitive function was assessed by Digit Symbol Substitution Test (DSST) and categorized into four quartiles (Q1-Q4). General characteristics and laboratory test results including serum klotho concentration and blood glucose levels were collected. Associations of cognitive function and klotho levels with blood glucose concentrations were explored through multivariate linear regression models. Mediation models were constructed to figure out the mediating role of klotho.

Results

All three multivariate linear regression models showed a negative correlation between blood glucose and cognitive function. (Model 1, β=-0.149, 95%CI: -0.202,-0.096, p=0.001; Model 2, β=-0.116, 95%CI: -0.167,-0.065, p=0.001; Model 3, β=-0.007, 95%CI: -0.118,-0.023, p=0.003). Mediation analysis showed that klotho mediated the statistical association between blood glucose level and cognitive function with proportions (%) of 12.5.

Conclusion

Higher blood glucose levels are associated with poorer cognitive performance in non-diabetic older adults, partially mediated through lower klotho levels.

Long-term calorie restriction prevented memory impairment in middle-aged male mice and increased a marker of DNA oxidative stress in hippocampal dentate gyrus

Calorie restriction (CR) is a non-invasive and economic approachknown to increase healthspan and life expectancy, through a decrease in oxidative stress, an increase in neurotrophins, among other benefits. However, it is not clear whether its benefit could be noted earlier, as at the beginning of middle-age. Hence, weaimed to determine whether six months of long-term CR, from early adulthood to the beginning of middle age (10 months of age) could positively affect cognitive, neurochemical, and behavioral parameters. Male C57BL6/J mice were randomly distributed into Young Control (YC, ad libitum food), Old Control (OC, ad libitum food), and Old Restricted (OR, 30 % of caloric restriction) groups. To analyze the cognitive and behavioral aspects, the novel object recognition task (NOR), open field, and elevated plus maze tests were performed. In addition, immunohistochemistry targetingΔFosB (neuronal activity), brain-derived neurotrophic factor (BDNF) and the DNA oxidative damage (8OHdG) in hippocampal subfields CA1, CA2, CA3, and dentate gyrus (DG), and in basolateral amygdala and striatum were performed. Our results showed that long-term CR prevented short-term memory impairment related to aging and increased 8OHdG in hippocampal DG. BDNF was not involved in the effects of either age or CR on memory at middle-age, as it increased in CA3 of the OC group but was not altered in OR. Regarding anxiety-type behavior, no parameter showed differences between the groups. In conclusion, while the effects of long-term CR on anxiety-type behavior were inconclusive, it mitigated the memory deficit related to aging, which was accompanied by an increase in hippocampal 8OHdG in DG. Future studies should investigate whether the benefits of CR would remain if the restriction were interrupted after this long-term protocol.

Calorie restriction protects against acute systemic LPS-induced inflammation

Caloric restriction (CR) has been proposed as a nutritional strategy to combat chronic diseases, including neurodegenerative diseases, as well as to delay aging. However, despite the benefits of CR, questions remain about its underlying mechanisms and cellular and molecular targets.Objective: As inflammatory processes are the basis or accompany chronic diseases and aging, we investigated the protective role of CR in the event of an acute inflammatory stimulus.Methods: Peripheral inflammatory and metabolic parameters were evaluated in Wistar rats following CR and/or acute lipopolysaccharide (LPS) administration, as well as glial changes (microglia and astrocytes), in two regions of the brain (hippocampus and hypothalamus) involved in the inflammatory response. We used a protocol of 30% CR, for 4 or 8 weeks. Serum and brain parameters were analyzed by biochemical or immunological assays.Results: Benefits of CR were observed during the inflammatory challenge, where the partial reduction of serum interleukin-6, mediated by CR, attenuated the systemic response. In the central nervous system (CNS), specifically in the hippocampus, CR attenuated the response to the LPS, as evaluated by tumor necrosis factor alpha (TNFα) levels. Furthermore, in the hippocampus, CR increased the glutathione (GSH) levels, resulting in a better antioxidant response.Discussion: This study contributes to the understanding of the effects of CR, particularly in the CNS, and expands knowledge about glial cells, emphasizing their importance in neuroprotection strategies.

Epigenetic and inflammatory markers in older adults with cancer: A Young International Society of Geriatric Oncology narrative review

The number of adults aged ≥ 65 years with cancer is rapidly increasing. Older adults with cancer are susceptible to treatment-related acute and chronic adverse events, resulting in loss of independence, reduction in physical function, and decreased quality of life. Nevertheless, evidence-based interventions to prevent or treat acute and chronic adverse events in older adults with cancer are limited. Several promising blood-based biomarkers related to inflammation and epigenetic modifications are available to identify older adults with cancer who are at increased risk of accelerated aging and physical, functional, and cognitive impairments caused by the cancer and its treatment. Inflammatory changes and epigenetic modifications can be reversible and targeted by lifestyle changes and interventions. Here we discuss ways in which changes in inflammatory and epigenetic pathways influence the aging process and how these pathways can be targeted by interventions aimed at reducing inflammation and aging-associated biological markers. As the number of older adults with cancer entering survivorship continues to increase, it is becoming progressively more important to understand ways in which the benefit from treatment can be enhanced while reducing the effects of accelerated aging.

Status of Research on Sestrin2 and Prospects for its Application in Therapeutic Strategies Targeting Myocardial Aging

Cardiac aging is accompanied by changes in the heart at the cellular and molecular levels, leading to alterations in cardiac structure and function. Given today's increasingly aging population, the decline in cardiac function caused by cardiac aging has a significant impact on quality of life. Antiaging therapies to slow the aging process and attenuate changes in cardiac structure and function have become an important research topic. Treatment with drugs, including metformin, spermidine, rapamycin, resveratrol, astaxanthin, Huolisu oral liquid, and sulforaphane, has been demonstrated be effective in delaying cardiac aging by stimulating autophagy, delaying ventricular remodeling, and reducing oxidative stress and the inflammatory response. Furthermore, caloric restriction has been shown to play an important role in delaying aging of the heart. Many studies in cardiac aging and cardiac aging-related models have demonstrated that Sestrin2 has antioxidant and anti-inflammatory effects, stimulates autophagy, delays aging, regulates mitochondrial function, and inhibits myocardial remodeling by regulation of relevant signaling pathways. Therefore, Sestrin2 is likely to become an important target for antimyocardial aging therapy.

Caloric Restriction: A Novel Conditioning Strategy to Improve the Survival of Ischemically Challenged Musculocutaneous Random Pattern Flaps

Caloric restriction (CR) is a cost-effective and easy-to-perform approach to counteracting surgical stress. The present study therefore evaluates the tissue-protective effects of a 30% CR in musculocutaneous flaps undergoing ischemia. For this purpose, a well-established murine dorsal skinfold chamber model, in combination with random pattern musculocutaneous flaps, was used. C57BL/6N mice were divided at random into a CR group (n = 8) and a control group with unrestricted access to standard chow (n = 8). The CR animals were subjected to a 30% reduction in caloric intake for 10 days before flap elevation. Intravital fluorescence microscopy was carried out on days 1, 3, 5, 7 and 10 after flap elevation to assess the nutritive blood perfusion, angiogenesis and flap necrosis. Subsequently, the flap tissue was harvested for additional histological and immunohistochemical analyses. The CR-treated animals exhibited a significantly higher functional capillary density and more newly formed microvessels within the flap tissue when compared to the controls; this was associated with a significantly higher flap survival rate. Immunohistochemical analyses showed a decreased invasion of myeloperoxidase-positive neutrophilic granulocytes into the flap tissue of the CR-treated mice. Moreover, the detection of cleaved caspase-3 revealed fewer cells undergoing apoptosis in the transition zone between the vital and necrotic tissue in the flaps of the CR-treated mice. These results demonstrate that a CR of 30% effectively prevents flap necrosis by maintaining microperfusion on a capillary level and inhibiting inflammation under ischemic stress. Hence, CR represents a promising novel conditioning strategy for improving the survival of musculocutaneous flaps with random pattern perfusion.

Counteracting Immunosenescence-Which Therapeutic Strategies Are Promising?

Aging attenuates the overall responsiveness of the immune system to eradicate pathogens. The increased production of pro-inflammatory cytokines by innate immune cells under basal conditions, termed inflammaging, contributes to impaired innate immune responsiveness towards pathogen-mediated stimulation and limits antigen-presenting activity. Adaptive immune responses are attenuated as well due to lowered numbers of naïve lymphocytes and their impaired responsiveness towards antigen-specific stimulation. Additionally, the numbers of immunoregulatory cell types, comprising regulatory T cells and myeloid-derived suppressor cells, that inhibit the activity of innate and adaptive immune cells are elevated. This review aims to summarize our knowledge on the cellular and molecular causes of immunosenescence while also taking into account senescence effects that constitute immune evasion mechanisms in the case of chronic viral infections and cancer. For tumor therapy numerous nanoformulated drugs have been developed to overcome poor solubility of compounds and to enable cell-directed delivery in order to restore immune functions, e.g., by addressing dysregulated signaling pathways. Further, nanovaccines which efficiently address antigen-presenting cells to mount sustained anti-tumor immune responses have been clinically evaluated. Further, senolytics that selectively deplete senescent cells are being tested in a number of clinical trials. Here we discuss the potential use of such drugs to improve anti-aging therapy.

Focus and Insights into the Synthetic Biology-Mediated Chassis of Economically Important Fungi for the Production of High-Value Metabolites

Substantial progress has been achieved and knowledge gaps addressed in synthetic biology-mediated engineering of biological organisms to produce high-value metabolites. Bio-based products from fungi are extensively explored in the present era, attributed to their emerging importance in the industrial sector, healthcare, and food applications. The edible group of fungi and multiple fungal strains defines attractive biological resources for high-value metabolites comprising food additives, pigments, dyes, industrial chemicals, and antibiotics, including other compounds. In this direction, synthetic biology-mediated genetic chassis of fungal strains to enhance/add value to novel chemical entities of biological origin is opening new avenues in fungal biotechnology. While substantial success has been achieved in the genetic manipulation of economically viable fungi (including Saccharomyces cerevisiae) in the production of metabolites of socio-economic relevance, knowledge gaps/obstacles in fungal biology and engineering need to be remedied for complete exploitation of valuable fungal strains. Herein, the thematic article discusses the novel attributes of bio-based products from fungi and the creation of high-value engineered fungal strains to promote yield, bio-functionality, and value-addition of the metabolites of socio-economic value. Efforts have been made to discuss the existing limitations in fungal chassis and how the advances in synthetic biology provide a plausible solution.

Modulation of nigral dopamine signaling mitigates parkinsonian signs of aging: evidence from intervention with calorie restriction or inhibition of dopamine uptake

Identifying neurobiological mechanisms of aging-related parkinsonism, and lifestyle interventions that mitigate them, remain critical knowledge gaps. No aging study, from rodent to human, has reported loss of any dopamine (DA) signaling marker near the magnitude associated with onset of parkinsonian signs in Parkinson's disease (PD). However, in substantia nigra (SN), similar loss of DA signaling markers in PD or aging coincide with parkinsonian signs. Alleviation of these parkinsonian signs may be possible by interventions such as calorie restriction (CR), which augment DA signaling markers like tyrosine hydroxylase (TH) expression in the SN, but not striatum. Here, we interrogated respective contributions of nigral and striatal DA mechanisms to aging-related parkinsonian signs in aging (18 months old) rats in two studies: by the imposition of CR for 6 months, and inhibition of DA uptake within the SN or striatum by cannula-directed infusion of nomifensine. Parkinsonian signs were mitigated within 12 weeks after CR and maintained until 24 months old, commensurate with increased D₁ receptor expression in the SN alone, and increased GDNF family receptor, GFR-α1, in the striatum, suggesting increased GDNF signaling. Nomifensine infusion into the SN or striatum selectively increased extracellular DA. However, only nigral infusion increased locomotor activity. These results indicate mechanisms that increase components of DA signaling in the SN alone mitigate parkinsonian signs in aging, and are modifiable by interventions, like CR, to offset parkinsonian signs, even at advanced age. Moreover, these results give evidence that changes in nigral DA signaling may modulate some parameters of locomotor activity autonomously from striatal DA signaling.

Birth outcomes, puberty onset, and obesity as long-term predictors of biological aging in young adulthood

Background

Biological aging and particularly the deviations between biological and chronological age are better predictors of health than chronological age alone. However, the predictors of accelerated biological aging are not very well understood. The aim was to determine the role of birth outcomes, time of puberty onset, body mass index (BMI), and body fat in accelerated biological aging in the third decade of life.

Methods

We have conducted a second follow-up of the Czech part of the European Longitudinal Study of Pregnancy and Childhood (ELSPAC-CZ) prenatal birth cohort in young adulthood (52% male; age 28-30; n = 262) to determine the role of birth outcomes, pubertal timing, BMI, and body fat on biological aging. Birth outcomes included birth weight, length, and gestational age at birth. Pubertal timing was determined by the presence of secondary sexual characteristics at the age of 11 and the age of first menarche in women. Biological age was estimated using the Klemera-Doubal Method (KDM), which applies 9-biomarker algorithm including forced expiratory volume in one second (FEV1), systolic blood pressure, glycated hemoglobin, total cholesterol, C-reactive protein, creatinine, urea nitrogen, albumin, and alkaline phosphatase. Accelerated/decelerated aging was determined as the difference between biological and chronological age (BioAGE).

Results

The deviations between biological and chronological age in young adulthood ranged from -2.84 to 4.39 years. Accelerated biological aging was predicted by higher BMI [in both early (R² _adj = 0.05) and late 20s (R² _adj = 0.22)], subcutaneous (R² _adj = 0.21) and visceral fat (R² _adj = 0.25), puberty onset (η _p ² = 0.07), birth length (R² _adj = 0.03), and the increase of BMI over the 5-year period between the two follow-ups in young adulthood (R² _adj = 0.09). Single hierarchical model revealed that shorter birth length, early puberty onset, and greater levels of visceral fat were the main predictors, together explaining 21% of variance in accelerated biological aging.

Conclusion

Our findings provide comprehensive support of the Life History Theory, suggesting that early life adversity might trigger accelerated aging, which leads to earlier onset of puberty but decreasing fitness in adulthood, reflected by more visceral fat and higher BMI. Our findings also suggest that reduction of BMI in young adulthood slows down biological aging.

Sedentary behavior and the biological hallmarks of aging

While the benefits of physical exercise for a healthy aging are well-recognized, a growing body of evidence shows that sedentary behavior has deleterious health effects independently, to some extent, of physical activity levels. Yet, the increasing prevalence of sedentariness constitutes a major public health issue that contributes to premature aging but the potential cellular mechanisms through which prolonged immobilization may accelerate biological aging remain unestablished. This narrative review summarizes the impact of sedentary behavior using different models of extreme sedentary behaviors including bedrest, unilateral limb suspension and space travel studies, on the hallmarks of aging such as genomic instability, telomere attrition, epigenetic alterations, loss of proteostasis, deregulated nutrient sensing, mitochondrial dysfunction, cellular senescence, stem cell exhaustion, and altered intercellular communication. We further highlight the remaining knowledge gaps that need more research in order to promote healthspan extension and to provide future contributions to the field of geroscience.

Diet Composition, Anthropometrics, and Mortality Risk

While overeating is considered a cause of the obesity epidemic as quantified by body mass index (BMI), the association of diet with a body shape index (ABSI) and hip index (HI), which are transformations of waist and hip circumference that are independent of BMI and which predict mortality risk, is poorly known. We used data from the Atherosclerosis Risk in Communities (ARIC) study of about 15,000 middle-aged adults to investigate associations between macronutrient intake (energy, carbohydrate, protein, and fat, the latter two divided into plant and animal sources, all based on self-reported food frequency) with anthropometric indices (BMI, ABSI, and HI). We also analyzed the association of diet and anthropometrics with death rate during approximately 30 years of follow-up. High intake of energy and animal fat and protein was generally associated with higher ABSI and lower HI at baseline, as well as greater mortality hazard. BMI was also positively linked with animal fat and protein intake. In contrast, higher intake of carbohydrates and plant fat and protein was associated with lower ABSI and BMI, higher HI, and lower mortality hazard. For example, after adjustment for potential confounders, each standard deviation of additional plant fat intake (as a fraction of total energy) was associated with a 5% decrease in mortality rate, while animal fat intake was associated with a 5% mortality increase per standard deviation. The directions of the associations between diet and anthropometrics are consistent with those found between anthropometrics and mortality without reference to diet.

Critical Assessment of In Vitro Screening of α-Glucosidase Inhibitors from Plants with Acarbose as a Reference Standard

Postprandial hyperglycemia is treated with the oral antidiabetic drug acarbose, an intestinal α-glucosidase inhibitor. Side effects of acarbose motivated a growing number of screening studies to identify novel α-glucosidase inhibitors derived from plant extracts and other natural sources. As "gold standard", acarbose is frequently included as the reference standard to assess the potency of these candidate α-glucosidase inhibitors, with many outperforming acarbose by several orders of magnitude. The results are subsequently used to identify suitable compounds/products with strong potential for in vivo efficacy. However, most α-glucosidase inhibitor screening studies use enzyme preparations obtained from nonmammalian sources (typically Saccharomyces cerevisiae), despite strong evidence that inhibition data obtained using nonmammalian α-glucosidase may hold limited value in terms of identifying α-glucosidase inhibitors with actual in vivo hypoglycemic potential. The aim was to critically discuss the screening of novel α-glucosidase inhibitors from plant sources, emphasizing inconsistencies and pitfalls, specifically where acarbose was included as the reference standard. An assessment of the available literature emphasized the cruciality of stating the biological source of α-glucosidase in such screening studies to allow for unambiguous and rational interpretation of the data. The review also highlights the lack of a universally adopted screening assay for novel α-glucosidase inhibitors and the commercial availability of a standardized preparation of mammalian α-glucosidase.

Food Security and Nutrition as the Neglected Missing Links in Cultural Evolution: The Role of the Sociotype

Food security and nutrition were major drivers of cultural evolution by enabling sociotypic development and communal living after the Neolithic agricultural revolution some 12,000 years ago. The sociotype unites concepts from the sciences and the humanities; in concert with the genotype it determines an individual's phenotype (observable traits and behavior), and together they advance societal culture. As such, the sociotype relates to an individual's dynamic interactions with the surrounding social environment throughout life and comprises three domains: the Individual, Relationships, and Context. Nutrition affects each domain, respectively, by ensuring the following dimensions of food security: utilization (metabolic fuel and health); accessibility (physical and economic); and availability (the right to nutritious food for all citizens). The sociotype is influenced by multiple factors, including diet-gene interactions, allostasis, microbiota, oxytocin, and culturally through mate selection, family bonds, social communication, political ideologies, and values. Food security, sociotypes, and culture form a complex adaptive system to enable coping with the circumstances of life in health and disease, to achieve sustainable development, and to eradicate hunger. The current geopolitical unrest highlights the absolutely critical role of this system for global security, yet many challenges remain in implementing this paradigm for society. Therefore, sustainable food security must be considered a fundamental human right and responsibility for safeguarding the survival and progress of the sociotypes of humankind (Homo culturus) worldwide.

Overweight Management through Mild Caloric Restriction in Multigenerational Long-Tailed Macaque Breeding Groups

Caloric restriction (CR) is an effective method to reduce overweight in captive non-human primates (NHPs). CR has been applied to individually- and pair-housed NHPs, but whether applying CR can be effective and safe in group-housed NHPs has not yet been assessed. This study investigates the effect of mild (20%) CR on adult overweight and biochemical parameters, immature growth, veterinary consultations, and reproductive success in multigenerational long-tailed macaque (Macaca fascicularis) breeding groups. Data were derived from anthropometric measurements and blood samples during yearly health checks, complemented with retrospective data on veterinary consultations and reproductive success. Adult body measures decreased after CR, with heavier individuals and females losing more weight compared to leaner individuals and males. CR lowered cholesterol levels in adults but had no overall effect on other biochemical parameters. Yet, biochemical parameters of individuals with high baseline values were reduced more compared to individuals with low baseline values. Immature growth, veterinary consultations and reproductive success were not influenced by CR. Thus, CR targeted the right individuals, i.e., overweight adults, and had no adverse effects on the variables examined in this study. This implies that mild CR can be a valuable overweight management strategy in group-housed NHPs.

Effect of Chronic Moderate Caloric Restriction on the Reproductive Function in Aged Male Wistar Rats

Caloric restriction (CR) has been shown to be an effective nutritional intervention for increasing longevity in some animal species. The objective of this study was to evaluate CR’s effects on metabolic and reproductive parameters in 12-month-old male Wistar rats. The rats were distributed in three groups: control, CR at 15%, and CR at 35% for 6 (up to 18 months of age) and 12 months (up to 24 months of age). At the end of CR treatment, we evaluated reproductive (male sexual behavior (MSB), sperm quality) and biochemical parameters (plasma glucose, glucose-regulating hormone, and sex steroid levels), and quantified annexin V in the seminiferous epithelium. Results showed that MSB and sperm quality were improved after 6 months of CR associated with increases in plasma testosterone and decrease annexin V in the seminiferous epithelium of the testicles compared to their control group. The metabolic profile of the CR rats also improved compared to controls. However, these effects of CR on reproductive parameters were not maintained after 12 months of CR. Findings suggest that beginning CR at the age of maturity reestablishes the behavioral sexual response and reproductive function in older animals after 6 months of CR and improves endocrine functioning during aging.

Effectiveness of high cardiorespiratory fitness in cardiometabolic protection in prediabetic rats

Background

Caloric restriction and exercise are lifestyle interventions that effectively attenuate cardiometabolic impairment. However, cardioprotective effects of long-term lifestyle interventions and short-term lifestyle interventions followed by weight maintenance in prediabetes have never been compared. High cardiorespiratory fitness (CRF) has been shown to provide protection against prediabetes and cardiovascular diseases, however, the interactions between CRF, prediabetes, caloric restriction, and exercise on cardiometabolic health has never been investigated.

Methods

Seven-week-old male Wistar rats were fed with either a normal diet (ND; n = 6) or a high-fat diet (HFD; n = 30) to induce prediabetes for 12 weeks. Baseline CRF and cardiometabolic parameters were determined at this timepoint. The ND-fed rats were fed continuously with a ND for 16 more weeks. The HFD-fed rats were divided into 5 groups (n = 6/group) to receive one of the following: (1) a HFD without any intervention for 16 weeks, (2) 40% caloric restriction for 6 weeks followed by an ad libitum ND for 10 weeks, (3) 40% caloric restriction for 16 weeks, (4) a HFD plus an exercise training program for 6 weeks followed by a ND without exercise for 10 weeks, or (5) a HFD plus an exercise training program for 16 weeks. At the end of the interventions, CRF and cardiometabolic parameters were re-assessed. Then, all rats were euthanized and heart tissues were collected.

Results

Either short-term caloric restriction or exercise followed by weight maintenance ameliorated cardiometabolic impairment in prediabetes, as indicated by increased insulin sensitivity, improved blood lipid profile, improved mitochondrial function and oxidative phosphorylation, reduced oxidative stress and inflammation, and improved cardiac function. However, these benefits were not as effective as those of either long-term caloric restriction or exercise. Interestingly, high-level baseline CRF was correlated with favorable cardiac and metabolic profiles at follow-up in prediabetic rats, both with and without lifestyle interventions.

Conclusions

Short-term lifestyle modification followed by weight maintenance improves cardiometabolic health in prediabetes. High CRF exerted protection against cardiometabolic impairment in prediabetes, both with and without lifestyle modification. These findings suggest that targeting the enhancement of CRF may contribute to the more effective treatment of prediabetes-induced cardiometabolic impairment.

Supplementary Information

The online version contains supplementary material available at 10.1186/s10020-022-00458-9.

Molecular Mechanisms of Exercise and Healthspan

Healthspan is the period of our life without major debilitating diseases. In the modern world where unhealthy lifestyle choices and chronic diseases taper the healthspan, which lead to an enormous economic burden, finding ways to promote healthspan becomes a pressing goal of the scientific community. Exercise, one of humanity's most ancient and effective lifestyle interventions, appears to be at the center of the solution since it can both treat and prevent the occurrence of many chronic diseases. Here, we will review the current evidence and opinions about regular exercise promoting healthspan through enhancing the functionality of our organ systems and preventing diseases.

Association Between Basal Metabolic Rate and All-Cause Mortality in a Prospective Cohort of Southern Chinese Adults

Objective: The aim of this study was to assess the relationship between basal metabolic rate (BMR) and all-cause mortality in southern Chinese adults. Methods: We prospectively examined the relationship between BMR and all-cause mortality in 12,608 Southern Chinese adults with age ≥ 35 years who participated in the National Key R&D Program from 2013-2014 to 2019-2020. Cox proportional hazard models were used to examine the association between BMR and all-cause mortality. Results: A total of 809 deaths (including 478 men and 331 women) occurred during a median follow-up period of 5.60 years. All-cause mortality was higher in elderly individuals than in non-elderly individuals (11.48 vs. 2.04%, P < 0.001) and was higher in male subjects than in female subjects (9.84 vs. 4.56%, P < 0.001). There was a significantly inverse relationship between BMR levels and all-cause mortality in elderly male individuals (adjusted-HR per SD increase: 0.80, 95% CI: 0.70-0.91, P < 0.001). Compared with BMR levels ≤ 1,115 kJ/day, there was lower all-cause mortality in third and highest BMR quartiles in the elderly male subjects (adjusted-HR: 0.71, 95% CI: 0.53-0.95, P = 0.022; adjusted-HR: 0.60, 95% CI: 0.43-0.84, P = 0.003, respectively). Conclusion: An elevated BMR was independently inversely associated with all-cause mortality in elderly male subjects in a southern Chinese population.

Immune Memory in Aging: a Wide Perspective Covering Microbiota, Brain, Metabolism, and Epigenetics

Non-specific innate and antigen-specific adaptive immunological memories are vital evolutionary adaptations that confer long-lasting protection against a wide range of pathogens. Adaptive memory is established by memory T and B lymphocytes following the recognition of an antigen. On the other hand, innate immune memory, also called trained immunity, is imprinted in innate cells such as macrophages and natural killer cells through epigenetic and metabolic reprogramming. However, these mechanisms of memory generation and maintenance are compromised as organisms age. Almost all immune cell types, both mature cells and their progenitors, go through age-related changes concerning numbers and functions. The aging immune system renders the elderly highly susceptible to infections and incapable of mounting a proper immune response upon vaccinations. Besides the increased infectious burden, older individuals also have heightened risks of metabolic and neurodegenerative diseases, which have an immunological component. This review discusses how immune function, particularly the establishment and maintenance of innate and adaptive immunological memory, regulates and is regulated by epigenetics, metabolic processes, gut microbiota, and the central nervous system throughout life, with a focus on old age. We explain in-depth how epigenetics and cellular metabolism impact immune cell function and contribute or resist the aging process. Microbiota is intimately linked with the immune system of the human host, and therefore, plays an important role in immunological memory during both homeostasis and aging. The brain, which is not an immune-isolated organ despite former opinion, interacts with the peripheral immune cells, and the aging of both systems influences the health of each other. With all these in mind, we aimed to present a comprehensive view of the aging immune system and its consequences, especially in terms of immunological memory. The review also details the mechanisms of promising anti-aging interventions and highlights a few, namely, caloric restriction, physical exercise, metformin, and resveratrol, that impact multiple facets of the aging process, including the regulation of innate and adaptive immune memory. We propose that understanding aging as a complex phenomenon, with the immune system at the center role interacting with all the other tissues and systems, would allow for more effective anti-aging strategies.

The Role of Immune Cells in Oxi-Inflamm-Aging

Aging is the result of the deterioration of the homeostatic systems (nervous, endocrine, and immune systems), which preserve the organism's health. We propose that the age-related impairment of these systems is due to the establishment of a chronic oxidative stress situation that leads to low-grade chronic inflammation throughout the immune system's activity. It is known that the immune system weakens with age, which increases morbidity and mortality. In this context, we describe how the function of immune cells can be used as an indicator of the rate of aging of an individual. In addition to this passive role as a marker, we describe how the immune system can work as a driver of aging by amplifying the oxidative-inflammatory stress associated with aging (oxi-inflamm-aging) and inducing senescence in far tissue cells. Further supporting our theory, we discuss how certain lifestyle conditions (such as social environment, nutrition, or exercise) can have an impact on longevity by affecting the oxidative and inflammatory state of immune cells, regulating immunosenescence and its contribution to oxi-inflamm-aging.

Impact of COVID-19 on Children and Young Adults With Type 2 Diabetes: A Narrative Review With Emphasis on the Potential of Intermittent Fasting as a Preventive Strategy

Background: The world is still struggling to control the COVID-19 pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The level of uncertainty regarding the virus is still significantly high. The virus behaves differently in children and young adults. Most children and adolescents are either asymptomatic or have mild symptoms. They generally have a very good prognosis. However, it is not well-known whether children and young adults with type 2 diabetes are at risk of getting a severe infection of COVID-19. Many Muslim children with type 2 diabetes have been performing dawn to dusk fasting during the month of Ramadan, before and during the COVID-19 pandemic, and the impact of this on their health has not been well investigated. Previous studies in adults have suggested that intermittent fasting may be beneficial in different ways including reversal of type 2 diabetes and prevention of COVID-19 infection. Objective: The primary aim of this narrative review is to summarise the impacts of the COVID-19 pandemic on children and young adults with type 2 diabetes, and to identify the knowledge gaps in the literature. It also explores the potential of intermittent fasting in reversing the pathogenesis of diabetes and highlighting how this approach could prevent these patients from developing chronic complications. Methods: This narrative review has been produced by examining several databases, including Google Scholar, Research Gate, PubMed, Cochrane Library, MEDLINE (EBSCO), and Web of Science. The most common search terms used were "COVID-19 AND Children", "SARS-CoV-2 AND/OR Children", "COVID-19 AND Diabetes" "COVID-19 Epidemiology", "COVID-19 AND Ramadan fasting", "COVID-19 and Intermittent fasting." All the resources used are either peer-reviewed articles/reports and/or official websites of various media, governmental and educational organisations. Results: Having reviewed the currently limited evidence, it has been found that the incidence of COVID-19 among children with type 2 diabetes seems to be not much different from children without diabetes. However, these patients are still vulnerable to any infection. Several studies have reported that prevention programmes such as intermittent fasting are effective to protect these groups of patients from developing any complications. Moreover, observing Ramadan fasting as a type of intermittent fasting could be beneficial for some children with established diabetes, prediabetes and people at risk. Conclusion: Children and young adults with type 2 diabetes are not at risk of severe COVID-19 infection as the case in adults with diabetes. More research is needed to identify the impact of COVID-19 and to investigate the efficacy and safety of intermittent fasting, including Ramadan fasting, among these age groups. Implementing these cost-effective programmes may have a great impact in minimising the incidence of diabetes. Moreover, this could be effective particularly at prediabetes stage by preventing these people from going onto develop type 2 diabetes and taking medications for the rest of their life and protecting people from complications linked to disease and infection.

Footprints in the Sand: Deep Taxonomic Comparisons in Vertebrate Genomics to Unveil the Genetic Programs of Human Longevity

With the modern quality, quantity, and availability of genomic sequencing across species, as well as across the expanse of human populations, we can screen for shared signatures underlying longevity and lifespan. Knowledge of these mechanisms would be medically invaluable in combating aging and age-related diseases. The diversity of longevities across vertebrates is an opportunity to look for patterns of genetic variation that may signal how this life history property is regulated, and ultimately how it can be modulated. Variation in human longevity provides a unique window to look for cases of extreme lifespan within a population, as well as associations across populations for factors that influence capacity to live longer. Current large cohort studies support the use of population level analyses to identify key factors associating with human lifespan. These studies are powerful in concept, but have demonstrated limited ability to resolve signals from background variation. In parallel, the expanding catalog of sequencing and annotation from diverse species, some of which have evolved longevities well past a human lifespan, provides independent cases to look at the genomic signatures of longevity. Recent comparative genomic work has shown promise in finding shared mechanisms associating with longevity among distantly related vertebrate groups. Given the genetic constraints between vertebrates, we posit that a combination of approaches, of parallel meta-analysis of human longevity along with refined analysis of other vertebrate clades having exceptional longevity, will aid in resolving key regulators of enhanced lifespan that have proven to be elusive when analyzed in isolation.

Extending lifespan by modulating the growth hormone/insulin-like growth factor-1 axis: coming of age

Progress made in the years of aging research have allowed the opportunity to explore potential interventions to slow aging and extend healthy lifespan. Studies performed in yeast, worms, flies and mice subjected to genetic and pharmacological interventions have given insight into the cellular and molecular mechanisms associated with longevity. Furthermore, it is now possible to effectively modulate pathways that slow aging at different stages of life (early life or at an adult age). Interestingly, interventions that extend longevity in adult mice have had sex-specific success, suggesting a potential link between particular pathways that modulate aging and sex. For example, reduction of the growth hormone (GH)/insulin-like growth factor-1 (IGF-1) axis at an adult age extends lifespan preferentially in females. Moreover, several postnatal dietary interventions tested by the 'Intervention Testing Program (ITP)' from the National Institute of Aging (NIA) have shown that while pharmacological interventions like rapamycin affect the IGF-1/insulin pathway and preferentially extend lifespan in females; dietary compounds that target other cellular pathways are effective only in male mice-indicating mutually exclusive sex-specific pathways. Therefore, a combination of interventions that target non-overlapping aging-related pathways appears to be an effective approach to further extend healthy lifespan in both sexes. Here, we review the germline and postnatal mouse lines that target the GH/IGF-1 axis as a mechanism to extend longevity as well as the dietary compounds that tested positive in the NIA program to increase lifespan. We believe that the interventions reviewed in this paper could constitute feasible combinations for an extended healthy lifespan in both male and female mice.

The marmoset as an important primate model for longitudinal studies of neurocognitive aging

Age-related cognitive decline has been extensively studied in humans, but the majority of research designs are cross-sectional and compare across younger and older adults. Longitudinal studies are necessary to capture variability in cognitive aging trajectories but are difficult to carry out in humans and long-lived nonhuman primates. Marmosets are an ideal primate model for neurocognitive aging as their naturally short lifespan facilitates longitudinal designs. In a longitudinal study of marmosets tested on reversal learning starting in middle-age, we found that, on average, the group of marmosets declined in cognitive performance around 8 years of age. However, we found highly variable patterns of cognitive aging trajectories across individuals. Preliminary analyses of brain tissues from this cohort also show highly variable degrees of neuropathology. Future work will tie together behavioral trajectories with brain pathology and provide a window into the factors that predict age-related cognitive decline.

The genetic predisposition to longevity acts through behavioral phenotypes in females

The discovery of genetic factors for the predisposition of longevity is promising but their functional role and clinical relevance remain largely unclear. Based on results from a large genome-wide association study (GWAS) on human longevity (N ≈ 390,000) we identified six phenotype categories belonging to behavioral and psychiatric traits showing significant genetic correlations using LD Hub. We validated these genetic correlations on the phenotype level in a general population sample using a polygenic risk score (PRS) based on the longevity GWAS as proxy for longevity (N ≈ 8190; Study of Health in Pomerania). The behavioral phenotypes education, smoking and body mass index (BMI) were highly associated with the PRS for longevity especially in females (p_education=0.003, p_smoking=0.049, p_BMI=2.0E-4) with increased rates for higher education, lower smoking rates and decrease in BMI attributed to a higher PRS for longevity. Moreover, the psychiatric phenotypes depression and subjective health complaints showed significant associations (p_DEPR=0.032, p_SHC=0.002) in females only. Generally, a higher genetic predisposition for longevity had a stronger association with behavioral phenotypes in females than in males. It is unclear what causes the higher ``behavioral heterogeneity'' in males but different biological mechanisms might be involved. Sensitivity analyses showed that the association for the PRS for longevity with BMI and smoking were robust against adjustment with the PRS for BMI and smoking. In conclusion, our analyses demonstrated that genetic information obtained from highly powered GWAS for longevity revealed a clear behavioral signature on the phenotype level in a smaller population based sample.

Sex, Food, and the Gut Microbiota: Disparate Response to Caloric Restriction Diet with Fiber Supplementation in Women and Men

SCOPE

Dietary-based strategies are regularly explored in controlled clinical trials to provide cost-effective therapies to tackle obesity and its comorbidities. The article presents a complementary analysis based on a multivariate multi-omics approach of a caloric restriction intervention (CRD) with fiber supplementation to unveil synergic effects on body weight control, lipid metabolism, and gut microbiota.

METHODS AND RESULTS

The study explores fecal bile acids (BAs) and short-chain fatty acids (SCFAs), plasma BAs, and fecal shotgun metagenomics on 80 overweight participants of a 12-week caloric restriction clinical trial (-500 kcal day^-1 ) randomly allocated into fiber (10 g day^-1 inulin + 10 g day^-1 resistant maltodextrin) or placebo (maltodextrin) supplementation groups. The multi-omic data integration analysis uncovered the benefits of the fiber supplementation and/or the CRD (e.g., increase of Parabacteroides distasonis and fecal propionate), showing sex-specific effects on either adiposity and fasting insulin; effects thought to be linked to changes of specific gut microbiota species, functional genes, and bacterially produced metabolites like SCFAs and secondary BAs.

CONCLUSIONS

This study identifies diet-microbe-host interactions helping to design personalised interventions. It also suggests that sex perspective should be considered routinely in future studies on dietary interventions efficacy. All in all, the study uncovers that the dietary intervention is more beneficial for women than men.

Aging and age-related diseases: from mechanisms to therapeutic strategies

Aging is a physiological process mediated by numerous biological and genetic pathways, which are directly linked to lifespan and are a driving force for all age-related diseases. Human life expectancy has greatly increased in the past few decades, but this has not been accompanied by a similar increase in their healthspan. At present, research on aging biology has focused on elucidating the biochemical and genetic pathways that contribute to aging over time. Several aging mechanisms have been identified, primarily including genomic instability, telomere shortening, and cellular senescence. Aging is a driving factor of various age-related diseases, including neurodegenerative diseases, cardiovascular diseases, cancer, immune system disorders, and musculoskeletal disorders. Efforts to find drugs that improve the healthspan by targeting the pathogenesis of aging have now become a hot topic in this field. In the present review, the status of aging research and the development of potential drugs for aging-related diseases, such as metformin, rapamycin, resveratrol, senolytics, as well as caloric restriction, are summarized. The feasibility, side effects, and future potential of these treatments are also discussed, which will provide a basis to develop novel anti-aging therapeutics for improving the healthspan and preventing aging-related diseases.

Adherence to Healthy Diet Can Delay Alzheimer's Diseases Development: A Systematic Review and Meta-Analysis

A healthy diet has long been indicated to be protective against Alzheimer’s diseases (AD). We carried out a systematic review and meta-analysis of published observational studies to explore the relationship between healthy and unhealthy diets and risk of ADs. We screened PubMed, Scopus, Web of Sciences, Google Scholar, Science Direct, and Embase, and screened manually to identify relevant articles published in English and non-English until Jun 2020. We classified the studied dietary patterns into two groups: healthy and unhealthy diets. The pooled weighted mean difference and 95% confidence interval (95% CI) was used to analyze the data using a random-effects model. The data were extracted manually and the preferred reporting items for systematic review and meta-analysis checklist was used to appraise the risk of bias and quality of data. Of the 1,813 articles identified, 21 met the inclusion criteria and were included in the quantitative analysis. A healthy diet was related to a lower risk of AD [odds ratio (OR): 0.45, 95% CI: 0.23 to 0.86, I²=99.7%; n=17 studies]. Moreover, high adherence to an unhealthy diet was not associated with increased risk of AD (OR: 0.99, 95% CI: 0.98 to 0.99, I²=0.0%; n=6 studies). However, the etiology of AD is uncertain and it is difficult draw conclusions about dietary healthy patterns. We concluded that adherence to a healthy diet is associated with a lower risk of AD, but were unable to find evidence that an unhealthy diet increases the risk of AD.

Repurposing drugs to fight aging: The difficult path from bench to bedside

The steady rise in life expectancy occurred across all developed countries during the last century. This demographic trend is, however, not accompanied by the same healthspan extension. This is since aging is the main risk factor for all age-associated pathological conditions. Therefore, slowing the rate of aging is suggested to be more efficient in preventing or delaying age-related diseases than treat them one by one, which is the common approach in a current pharmacological disease-oriented paradigm. To date, a variety of medications designed to treat particular pathological conditions have been shown to exhibit pro-longevity effects in different experimental models. Among them, there are many commonly used prescription and over-the-counter pharmaceuticals such as metformin, rapamycin, aspirin, statins, melatonin, vitamin antioxidants, etc. All of them are being increasingly investigated in preclinical and clinical trials with the aim of determine whether they have potential for extension of human healthspan. The results from these trials are frequently inconclusive and fall short of initial expectations, suggesting that innovative research ideas and additional translational steps are required to overcome obstacles for implementation of such approaches in clinical practice. In this review, recent advances and challenges in the field of repurposing widely used conventional pharmaceuticals to target the aging process are summarized and discussed.

Exogenous Ketones as Therapeutic Signaling Molecules in High-Stress Occupations: Implications for Mitigating Oxidative Stress and Mitochondrial Dysfunction in Future Research

High-stress occupations (ie, firefighters, military personnel, police officers, etc.) are often plagued by cardiometabolic diseases induced by exposure to chronic stressors. Interrupted sleep cycles, poor dietary patterns, lack of physical activity, and smoke exposure along with simultaneous psychological stressors promote chronic low-grade inflammation and excessive oxidative stress. Collectively, these data suggest that practical interventions which might mitigate the underlying pathologies of these cardiometabolic diseases are warranted. Ketones, specifically R-βHB, modulates intracellular signaling cascades such as the cellular redox ratios of NAD+/NADH, the activity of NAD dependent deacetylases SIRT1 and SIRT3, and promotes a robust mitochondrial environment which favors reductions in oxidative stress and inflammation. To date, the literature examining R-βHB as a signaling metabolite has mostly been performed from endogenous R-βHB production achieved through nutritional ketosis or cell culture and mouse models using exogenous R-βHB. To the authors knowledge, only 1 study has attempted to report on the effects of exogenous ketones and the mitigation of oxidative stress/inflammation. Therefore, the scope of this review is to detail the mechanisms of R-βHB as a signaling metabolite and the role that exogenous ketones might play in mitigating diseases in individuals serving in high-stress occupations.

Adipokines, Myokines, and Cardiokines: The Role of Nutritional Interventions

It is now established that adipose tissue, skeletal muscle, and heart are endocrine organs and secrete in normal and in pathological conditions several molecules, called, respectively, adipokines, myokines, and cardiokines. These secretory proteins constitute a closed network that plays a crucial role in obesity and above all in cardiac diseases associated with obesity. In particular, the interaction between adipokines, myokines, and cardiokines is mainly involved in inflammatory and oxidative damage characterized obesity condition. Identifying new therapeutic agents or treatment having a positive action on the expression of these molecules could have a key positive effect on the management of obesity and its cardiac complications. Results from recent studies indicate that several nutritional interventions, including nutraceutical supplements, could represent new therapeutic agents on the adipo-myo-cardiokines network. This review focuses the biological action on the main adipokines, myokines and cardiokines involved in obesity and cardiovascular diseases and describe the principal nutraceutical approaches able to regulate leptin, adiponectin, apelin, irisin, natriuretic peptides, and follistatin-like 1 expression.

Guirlanda C, A. F. Moura M. Use of the Versatility of Fungal Metabolism to Meet Modern Demands for Healthy Aging, Functional Foods, and Sustainability

Aging-associated, non-transmissible chronic diseases (NTCD) such as cancer, dyslipidemia, and neurodegenerative disorders have been challenged through several strategies including the consumption of healthy foods and the development of new drugs for existing diseases. Consumer health consciousness is guiding market trends toward the development of additives and nutraceutical products of natural origin. Fungi produce several metabolites with bioactivity against NTCD as well as pigments, dyes, antioxidants, polysaccharides, and enzymes that can be explored as substitutes for synthetic food additives. Research in this area has increased the yields of metabolites for industrial applications through improving fermentation conditions, application of metabolic engineering techniques, and fungal genetic manipulation. Several modern hyphenated techniques have impressively increased the rate of research in this area, enabling the analysis of a large number of species and fermentative conditions. This review thus focuses on summarizing the nutritional, pharmacological, and economic importance of fungi and their metabolites resulting from applications in the aforementioned areas, examples of modern techniques for optimizing the production of fungi and their metabolites, and methodologies for the identification and analysis of these compounds.

Age-related memory decline, dysfunction of the hippocampus and therapeutic opportunities

While the aging of the population is a sign of progress for societies, it also carries its load of negative aspects. Among them, cognitive decline and in particular memory loss is a common feature of non-pathological aging. Autobiographical memories, which rely on the hippocampus, are a primary target of age-related cognitive decline. Here, focusing on the neurobiological mechanisms of memory formation and storage, we describe how hippocampal functions are altered across time in non-pathological mammalian brains. Several hallmarks of aging have been well described over the last decades; among them, we consider altered synaptic communication and plasticity, reduction of adult neurogenesis and epigenetic alterations. Building on the neurobiological processes of cognitive aging that have been identified to date, we review some of the strategies based on lifestyle manupulation allowing to address age-related cognitive deficits.

Polyphenols as Caloric-Restriction Mimetics and Autophagy Inducers in Aging Research

It has been thought that caloric restriction favors longevity and healthy aging where autophagy plays a vital role. However, autophagy decreases during aging and that can lead to the development of aging-associated diseases such as cancer, diabetes, neurodegeneration, etc. It was shown that autophagy can be induced by mechanical or chemical stress. In this regard, various pharmacological compounds were proposed, including natural polyphenols. Apart from the ability to induce autophagy, polyphenols, such as resveratrol, are capable of modulating the expression of pro- and anti-apoptotic factors, neutralizing free radical species, affecting mitochondrial functions, chelating redox-active transition metal ions, and preventing protein aggregation. Moreover, polyphenols have advantages compared to chemical inducers of autophagy due to their intrinsic natural bio-compatibility and safety. In this context, polyphenols can be considered as a potential therapeutic tool for healthy aging either as a part of a diet or as separate compounds (supplements). This review discusses the epigenetic aspect and the underlying molecular mechanism of polyphenols as an anti-aging remedy. In addition, the recent advances of studies on NAD-dependent deacetylase sirtuin-1 (SIRT1) regulation of autophagy, the role of senescence-associated secretory phenotype (SASP) in cells senescence and their regulation by polyphenols have been highlighted as well. Apart from that, the review also revised the latest information on how polyphenols can help to improve mitochondrial function and modulate apoptosis (programmed cell death).

Planarian cell number depends on blitzschnell, a novel gene family that balances cell proliferation and cell death

Control of cell number is crucial to define body size during animal development and to restrict tumoral transformation. The cell number is determined by the balance between cell proliferation and cell death. Although many genes are known to regulate those processes, the molecular mechanisms underlying the relationship between cell number and body size remain poorly understood. This relationship can be better understood by studying planarians, flatworms that continuously change their body size according to nutrient availability. We identified a novel gene family, blitzschnell (bls), that consists of de novo and taxonomically restricted genes that control cell proliferation:cell death ratio. Their silencing promotes faster regeneration and increases cell number during homeostasis. Importantly, this increase in cell number leads to an increase in body size only in a nutrient-rich environment; in starved planarians, silencing results in a decrease in cell size and cell accumulation that ultimately produces overgrowths. bls expression is downregulated after feeding and is related to activity of the insulin/Akt/mTOR network, suggesting that the bls family evolved in planarians as an additional mechanism for restricting cell number in nutrient-fluctuating environments.

Caloric Restriction Reprograms the Single-Cell Transcriptional Landscape of Rattus Norvegicus Aging

Aging causes a functional decline in tissues throughout the body that may be delayed by caloric restriction (CR). However, the cellular profiles and signatures of aging, as well as those ameliorated by CR, remain unclear. Here, we built comprehensive single-cell and single-nucleus transcriptomic atlases across various rat tissues undergoing aging and CR. CR attenuated aging-related changes in cell type composition, gene expression, and core transcriptional regulatory networks. Immune cells were increased during aging, and CR favorably reversed the aging-disturbed immune ecosystem. Computational prediction revealed that the abnormal cell-cell communication patterns observed during aging, including the excessive proinflammatory ligand-receptor interplay, were reversed by CR. Our work provides multi-tissue single-cell transcriptional landscapes associated with aging and CR in a mammal, enhances our understanding of the robustness of CR as a geroprotective intervention, and uncovers how metabolic intervention can act upon the immune system to modify the process of aging.

Long-term caloric restriction activates the myocardial SIRT1/AMPK/PGC-1α pathway in C57BL/6J male mice

Background

Caloric restriction (CR) can help in improving heart function. There is as yet no consensus on the mechanism of the effect of CR. Silent mating-type information regulation 1 (SIRT1), adenosine monophosphate-activated protein kinase (AMPK), and mTOR are key players in metabolic stress management. We aimed to explore the effect of CR on the myocardial SIRT1/AMPK/mTOR pathway in mice.

Methods

Thirty-six 6-week-old male C57BL/6J mice were randomly divided into three groups: normal control group (NC group, n = 12), high-energy group (HE group, n = 12) and CR group (n = 12) according to different diets. After 11 months, western blot was used to examine proteins such as p-AMPK, peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α), SIRT1, and p-mTOR, whereas real-time PCR was used to examine the expression of AMPK, PGC-1α, and SIRT1 transcripts.

Results

Compared to the HE group, the CR group displayed increased expression of myocardial p-AMPK protein, SIRT1 protein and mRNA, and PGC-1a mRNA. However, no difference was observed in the expression of p-mTOR protein and mTOR mRNA in the myocardium among the three groups.

Conclusions

CR improves the SIRT1/AMPK/PGC-1α pathway in mice myocardium with no effect on the mTOR pathway.