Adipose tissue, diet and aging

Effectiveness of Body Remodeling and Cellulite Appearance Improvement Treatments in the Thighs Using Symmed Radiofrequency Device

BACKGROUND

Aging associated with the passage of time causes alterations in subcutaneous tissues and the overall appearance of the skin that generate aesthetic unconformities in people. Within the wide range of available techniques on the market, radiofrequency (RF) diathermy has emerged as one of the most used non-invasive methods to combat them.

OBJECTIVE

This clinical trial aims to determine and quantify the effectiveness and safety of the high-frequency RF-based device Symmed (Termosalud Inc., Gijón, Spain) in cellulite appearance improvement and thigh remodeling treatments.

MATERIAL AND METHODS

Eight sessions of Symmed were performed every 72/96 h in eight subjects' thighs. Safety and effectiveness of the device were evaluated before and after the treatments by digital photographs, body contours measurements, and ultrasound images of skin echogenicity and fat tissue thickness. Information regarding the satisfaction level of the participants was obtained throughout a customized questionnaire.

RESULTS

After the treatments, significant reductions of 3% in thighs circumferences (p < 0.05) and 20% in subcutaneous fat layer thickness (p < 0.01) were detected. Dermal echogenicity, used as an indicator of skin organization and collagen content, showed a significant 6% increase (p < 0.05). Before and after photographs revealed a general improvement in skin appearance. The results were complemented by a high satisfaction level (100%) and the absence of adverse events.

CONCLUSION

Symmed RF therapy is a non-invasive, safe, effective, and well-tolerated procedure for the treatment of thighs cellulite appearance and body remodeling.

The companion dog as a model for inflammaging: a cross-sectional pilot study

Inflammaging, the chronic, progressive proinflammatory state associated with aging, has been associated with multiple negative health outcomes in humans. The pathophysiology of inflammaging is complex; however, it is often characterized by high serum concentrations of inflammatory mediators such as tumor necrosis factor alpha (TNF-α), interleukin (IL)-6, and C-reactive protein (CRP). Few studies have evaluated the effects of age on inflammatory cytokines in companion dogs, and most of these studies included dogs of a single breed. In this cross-sectional study, we measured multiple circulating inflammatory markers and hematological parameters in banked serum samples from 47 healthy companion dogs of various breeds enrolled in the Dog Aging Project. Using univariate linear models, we investigated the association of each of these markers with age, sex, body weight, and body condition score (BCS), a measure of obesity in the dog. Serum IL-6, IL-8, and TNF-α concentrations were all positively associated with age. Lymphocyte count was negatively associated with age. Platelet count had a negative association with body weight. IL-2, albumin, cholesterol, triglyceride, bilirubin, S100A12, and NMH concentrations were not associated with age, weight, BCS, or sex after adjustment for multiple comparisons. Our findings replicate previous findings in humans, including increases in IL-6 and TNF-α with age, giving more evidence to the strength of the companion dog as a model for human aging.

Association between inflammatory markers, body composition and frailty in home-dwelling elderly: an 8-year follow-up study

Frailty has been linked to inflammation and changes in body composition, but the findings are inconsistent. To explore this, we used the Frailty Index (FI) definition to (1) investigate the association between levels of inflammatory markers (baseline) and change in FI score after 8 years of follow-up and (2) investigate the longitudinal associations between inflammatory markers, body composition, and frailty. Home-dwelling elderly (≥ 70 years) were invited to participate in the study and re-invited to a follow-up visit 8 years later. This study includes a total of 133 participants. The inflammatory markers included were high-sensitive C-reactive protein (hs-CRP), interleukin 6 (IL-6), tumor necrosis factor alpha (TNF-α), and glycoprotein acetyls (Gp-acetyls). We used the body composition markers fat mass, fat-free mass, and waist circumference. The FI score consisted of 38 variables. Additional clinical assessments such as blood pressure and body mass index (BMI), as well as information about daily medications, were collected at both visits. Linear regression model and Spearman's rank correlation were used to investigate associations. We showed that the FI score increased after 8 years, and participants with higher hs-CRP levels at baseline had the largest change in the FI score. Changes in fat mass were significantly correlated with changes in hs-CRP and IL-6, and changes in waist circumference were significantly correlated with changes in TNF-α. The use of drugs increased during the 8 years of follow-up, which may have attenuated the associations between inflammation and frailty. However, elevated concentrations of hs-CRP in the elderly may be associated with an increased risk of frailty in subsequent years.

Adipose Tissue Plasticity: A Comprehensive Definition and Multidimensional Insight

Adipose tissue is composed of adipocytes, stromal vascular fraction, nerves, surrounding immune cells, and the extracellular matrix. Under various physiological or pathological conditions, adipose tissue shifts cellular composition, lipid storage, and organelle dynamics to respond to the stress; this remodeling is called "adipose tissue plasticity". Adipose tissue plasticity includes changes in the size, species, number, lipid storage capacity, and differentiation function of adipocytes, as well as alterations in the distribution and cellular composition of adipose tissue. This plasticity has a major role in growth, obesity, organismal protection, and internal environmental homeostasis. Moreover, certain thresholds exist for this plasticity with significant individualized differences. Here, we comprehensively elaborate on the specific connotation of adipose tissue plasticity and the relationship between this plasticity and the development of many diseases. Meanwhile, we summarize possible strategies for treating obesity in response to adipose tissue plasticity, intending to provide new insights into the dynamic changes in adipose tissue and contribute new ideas to relevant clinical problems.

Chinese Visceral Adiposity Index Predict Prehypertension Progression and Regression: A Prospective Cohort Study Involving Middle-Aged and Older Adults

BACKGROUND

Limited data are published on the relationship of the Chinese visceral adiposity index (CVAI) with prehypertension progression or regression. Therefore, we investigated this association through the China Health and Retirement Longitudinal Study.

METHODS

Participants with prehypertension were assigned to two groups according to baseline CVAI, and after 4 years of follow-up, their blood pressure was analyzed for deterioration or improvement. We constructed logistic regression models for assessing the association of CVAI with the progression or regression of prehypertension. A restricted cubic spline (RCS) model was utilized for determining the dose-response association. Subgroup analysis and sensitivity analysis were also conducted.

RESULTS

The study included 2,057 participants with prehypertension. During the follow-up, 695 participants progressed to hypertension, 561 participants regressed to normotension, and 801 participants remained as prehypertensive. An association was observed between a high CVAI value and a higher incidence of progression to hypertension and between a high CVAI value and a lower incidence of regression to normotension (OR = 1.66 and 0.58, 95% CI: 1.35-2.05 and 0.47-0.73, respectively). The RCS model exhibited a linear association between CVAI and prehypertension progression and regression (all P for non-linear > 0.05). The results of the subgroup and sensitivity analyses agreed with those of the primary analysis.

CONCLUSIONS

A significant association was noted between CVAI and prehypertension progression and regression. Thus, as part of the hypertension prevention strategy, monitoring CVAI is crucial in individuals with prehypertension.

Dietary dibutyryl cAMP supplementation regulates the fat deposition in adipose tissues of finishing pigs via cAMP/PKA pathway

This study investigated potential mechanism of dibutyryl-cAMP (db-cAMP) on porcine fat deposition. (1) Exp.1, 72 finishing pigs were allotted to 3 treatments (0, 10 or 20 mg/kg dbcAMP) with 6 replicates. dbcAMP increased the hormone sensitive lipase (HSL) activity and expression of β-adrenergic receptor (β-AR) and growth hormone receptor (GHR), but decreased expression of peroxisome proliferator-activated receptor gamma 2 (PPAR-γ2) and adipocyte fatty acid binding protein (A-FABP) in back fat. dbcAMP upregulated expression of β-AR, GHR, PPAR-γ2 and A-FABP, but decreased insulin receptor (INSR) expression in abdominal fat. Dietary dbcAMP increased HSL activity and expression of G protein-coupled receptor (GPCR), cAMP-response element-binding protein (CREB) and insulin-like growth factor-1 (IGF-1), but decreased fatty acid synthase (FAS) and lipoprotein lipase (LPL) activities, and expression of INSR, cAMP-response element-binding protein (C/EBP-α) and A-FABP in perirenal fat. (2) Exp. 2, dbcAMP suppressed the proliferation and differentiation of porcine preadipocytes in a time- and dose-dependent manner, which might be associated with increased activities of cAMP and protein kinase A (PKA), and expression of GPCR, β-AR, GHR and CREB via inhibiting C/EBP-α and PPAR-γ2 expression. Collectively, dbcAMP treatment may reduce fat deposition by regulating gene expression related to adipocyte differentiation and fat metabolism partially via cAMP-PKA pathway.

Sex differences in the associations of sleep-wake characteristics and rest-activity circadian rhythm with specific obesity types among Hong Kong community-dwelling older adults

BACKGROUND

Sex differences exist in sleep characteristics, circadian rhythm and body composition but the evidence on their associations with obesity risk remains unclear. We aimed to examine sex differences in the associations of sleep-wake cycle and rest-activity circadian rhythm with specific obesity types among aged Chinese population.

METHODS

This report pooled data from 2 population-based surveys conducted during 4/2018-9/2018 and 7/2019-9/2020. All participants wore actigraphy on wrists for 7 days to measure their objective sleep patterns and rest-activity circadian rhythm. We measured participants' anthropometric data, and obtained their body weight, body fat percentage(fat%), visceral fat rating, muscle mass by calibrated bioelectrical impedance analysis device. Hand-grip strength was assessed by Jamar Hydraulic hand dynamometer. Multinomial logistic regression was performed to assess the odds ratio(OR) and 95% confidence intervals(95%CI).

RESULTS

We recruited 206 male and 134 female older adults with complete actigraphy data, with obesity prevalence of 36.9% and 31.3%, respectively. Male participants who had delayed sleep-wake cycle(i.e.,sleep-onset-time and wake-up time) was associated with higher risk of obesity(late sleep-onset-time:OR=5.28, 95%CI=2.00-13.94), and the results remained consistent for different types of obesity. Males with late M10(i.e., most active 10-hours) onset had higher adipose outcomes with an adjusted OR of 2.92(fat%:95%CI=1.10-7.71; visceral fat:95%CI=1.12-7.61). Among female participants, those with lower relative amplitude were associated with higher BMI and lower hand-grip strength.

CONCLUSIONS

This study revealed that circadian rhythm fragmentation was associated with obesity and muscle loss. Promoting good sleep quality and maintaining robust circadian rhythm and physical activity can prevent poor muscle strength among older adults.

Age-Related Dietary Habits and Blood Biochemical Parameters in Patients with and without Steatosis-MICOL Cohort

BACKGROUND

Steatosis is now the most common liver disease in the world, present in approximately 25% of the global population. The aim of this study was to study the association between food intake and liver disease and evaluate the differences in blood parameters in age classes and steatosic condition.

METHODS

The present study included 1483 participants assessed in the fourth recall of the MICOL study. Patients were subdivided by age (65 years) and administered a validated food frequency questionnaire (FFQ) with 28 food groups.

RESULTS

The prevalence of steatosis was 55.92% in the adult group and 55.88% in the elderly group. Overall, the results indicated many statistically significant blood parameters and dietary habits. Analysis of food choices with a machine learning algorithm revealed that in the adult group, olive oil, grains, processed meat, and sweets were associated with steatosis, while the elderly group preferred red meat, dairy, seafood, and fruiting vegetables. Furthermore, the latter ate less as compared with the adult group.

CONCLUSIONS

Many differences were found between the two age groups, both in blood parameters and food intake. The random forest also revealed different foods predicted steatosis in the two groups. Future analysis will be useful to understand the molecular basis of these differences and how different food intake causes steatosis in people of different ages.

Associations of Chinese visceral adiposity index and new-onset stroke in middle-aged and older Chinese adults: an observational study

BACKGROUND

Stroke represents the second most prevalent contributor to global mortality. The Chinese Visceral Adiposity Index (CVAI) serves as an established metric for assessing visceral adiposity in the Chinese population, exhibiting prognostic capabilities. This investigation aimed to explore the association of CVAI and new-onset stroke among middle-aged and older Chinese populations.

METHODS

The study employed data from the 2011 and 2018 China Health and Retirement Longitudinal Study (CHARLS) to assess the association of CVAI and the incidence of new-onset stroke. Utilizing a directed acyclic graph (DAG), 10 potential confounders were identified. Moreover, to explore the association between CVAI and new-onset stroke, three multifactor logistic regression models were constructed, accounting for the identified confounders and mitigating their influence on the findings.

RESULTS

The study comprised 7070 participants, among whom 417 (5.9%) experienced new-onset strokes. After controlling for confounding variables, regression analysis suggested that the new-onset stroke's highest risk was linked to the fourth quartile (Q4) of the CVAI, with an odds ratio (OR) of 2.33 and a 95% confidence interval (CI) of 1.67-3.28. The decision tree analysis demonstrated a heightened probability of new-onset stroke among hypertensive individuals with a CVAI equal to or greater than 83, coupled with a C-reactive protein level no less than 1.1 mg/l. Age seemed to have a moderating influence on the CVAI and new-onset stroke association, exhibiting a more prominent interaction effect in participants under 60 years.

CONCLUSIONS

In middle-aged and older Chinese populations, a linear relationship was discerned between CVAI and the probability of new-onset stroke. CVAI provides a predictive framework for stroke incidence in this demographic, laying the groundwork for more sophisticated risk prediction models that improve the precision and specificity of stroke risk evaluations.

Effects of aging-induced obesity on the transcriptional expression of adipogenesis and thermogenic activity in the gonadal white adipose, brown adipose, and skeletal muscle tissues

PURPOSE

Aging is closely associated with chronic metabolic diseases, such as obesity, which lead to increased adiposity, skeletal muscle wasting, and imbalanced cellular energy metabolism. However, transcriptional profiles representing energy imbalances in aging-induced obesity are not fully understood. Thus, this study aimed to investigate the candidate genes predominantly regulated in aging-related obesity in spontaneously aged mice.

METHODS

Male C57BL/6J mice were divided into three age groups according to age: 2- (young), 12- (middle-aged), and 24- (old) months. Body weight and body composition parameters were measured in all mice. Gonadal white adipose tissue (gWAT), brown adipose tissue (BAT), and skeletal muscle (SM) were dissected and weighed. The target tissues were assessed using biochemical and histological assays.

RESULTS

Aging-induced obesity increased adipose mass and decreased SM weight through processes of adipocyte hypertrophy; however, recruitment of modulating adipogenesis-inducing transcription factors did not occur. Among adipokines, leptin level was greatly increased in the gWAT during aging. Interestingly, the β2-adrenergic receptor had a higher affinity than the β3-adrenergic receptor in aging-induced obesity. For the thermogenic regulation through β-adrenergic receptors (β-ARs), a declined uncoupling protein-1 (UCP-1) in the BAT was relevant to aging-induced obesity.

CONCLUSION

Aging-induced obesity increases leptin levels in adipocytes and decreases UCP-1 in BAT through β-ARs, according to transcriptional gene profiling. WAT browning increases energy expenditure due to exercise training adaptations. Further research is needed to discover more effective methods, such as exercise, against aging-induced obesity.

Circadian mechanisms in adipose tissue bioenergetics and plasticity

The circadian clock plays an essential role in coordinating feeding and metabolic rhythms with the light/dark cycle. Disruption of clocks is associated with increased adiposity and metabolic disorders, whereas aligning feeding time with cell-autonomous rhythms in metabolism improves health. Here, we provide a comprehensive overview of recent literature in adipose tissue biology as well as our understanding of molecular mechanisms underlying the circadian regulation of transcription, metabolism, and inflammation in adipose tissue. We highlight recent efforts to uncover the mechanistic links between clocks and adipocyte metabolism, as well as its application to dietary and behavioral interventions to improve health and mitigate obesity.

Aged brain and neuroimmune responses to COVID-19: post-acute sequelae and modulatory effects of behavioral and nutritional interventions

Advanced age is one of the significant risk determinants for coronavirus disease 2019 (COVID-19)-related mortality and for long COVID complications. The contributing factors may include the age-related dynamical remodeling of the immune system, known as immunosenescence and chronic low-grade systemic inflammation. Both of these factors may induce an inflammatory milieu in the aged brain and drive the changes in the microenvironment of neurons and microglia, which are characterized by a general condition of chronic inflammation, so-called neuroinflammation. Emerging evidence reveals that the immune privilege in the aging brain may be compromised. Resident brain cells, such as astrocytes, neurons, oligodendrocytes and microglia, but also infiltrating immune cells, such as monocytes, T cells and macrophages participate in the complex intercellular networks and multiple reciprocal interactions. Especially changes in microglia playing a regulatory role in inflammation, contribute to disturbing of the brain homeostasis and to impairments of the neuroimmune responses. Neuroinflammation may trigger structural damage, diminish regeneration, induce neuronal cell death, modulate synaptic remodeling and in this manner negatively interfere with the brain functions.In this review article, we give insights into neuroimmune interactions in the aged brain and highlight the impact of COVID-19 on the functional systems already modulated by immunosenescence and neuroinflammation. We discuss the potential ways of these interactions with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and review proposed neuroimmune mechanisms and biological factors that may contribute to the development of persisting long COVID conditions. We summarize the potential mechanisms responsible for long COVID, including inflammation, autoimmunity, direct virus-mediated cytotoxicity, hypercoagulation, mitochondrial failure, dysbiosis, and the reactivation of other persisting viruses, such as the Cytomegalovirus (CMV). Finally, we discuss the effects of various interventional options that can decrease the propagation of biological, physiological, and psychosocial stressors that are responsible for neuroimmune activation and which may inhibit the triggering of unbalanced inflammatory responses. We highlight the modulatory effects of bioactive nutritional compounds along with the multimodal benefits of behavioral interventions and moderate exercise, which can be applied as postinfectious interventions in order to improve brain health.

Age-dependent nuclear lipid droplet deposition is a cellular hallmark of aging in Caenorhabditis elegans

Aging is the major risk factor for several life-threatening pathologies and impairs the function of multiple cellular compartments and organelles. Age-dependent deterioration of nuclear morphology is a common feature in evolutionarily divergent organisms. Lipid droplets have been shown to localize in most nuclear compartments, where they impinge on genome architecture and integrity. However, the significance of progressive nuclear lipid accumulation and its impact on organismal homeostasis remain obscure. Here, we implement non-linear imaging modalities to monitor and quantify age-dependent nuclear lipid deposition in Caenorhabditis elegans. We find that lipid droplets increasingly accumulate in the nuclear envelope, during aging. Longevity-promoting interventions, such as low insulin signaling and caloric restriction, abolish the rate of nuclear lipid accrual and decrease the size of lipid droplets. Suppression of lipotoxic lipid accumulation in hypodermal and intestinal nuclei is dependent on the transcription factor HLH-30/TFEB and the triglyceride lipase ATGL-1. HLH-30 regulates the expression of ATGL-1 to reduce nuclear lipid droplet abundance in response to lifespan-extending conditions. Notably, ATGL-1 localizes to the nuclear envelope and moderates lipid content in long-lived mutant nematodes during aging. Our findings indicate that the reduced ATGL-1 activity leads to excessive nuclear lipid accumulation, perturbing nuclear homeostasis and undermining organismal physiology, during aging.

Effect of Resistance Exercise Order on Cardiovascular Disease Risk Factors in Older Women: A Randomized Controlled Trial

We compared the effects of two specific resistance training (RT) exercise orders on cardiovascular risk factors. Forty-four untrained older women (>60 years) were randomly assigned to three groups: control (CON, n = 15), multi-joint to single-joint (MJ-SJ, n = 14), and single-joint to multi-joint (SJ-MJ, n = 15) exercise orders. Training groups performed a whole-body RT program (eight exercises, 3 × 10−15 repetitions for each exercise) over 12 weeks in 3 days/week. Body fat, triglycerides, total cholesterol, HDL-c, LDL-c, VLDL-c, glucose, IL-6, IL-10, TNF-α, C-reactive protein, total radical-trapping antioxidant (TRAP), advanced oxidation protein products (AOPP), ferrous oxidation-xylenol (FOX), and nitric oxide concentrations (NOx) were determined pre- and post-intervention. Significant interaction group × time (p < 0.05) revealed reducing fat mass and trunk fat and improvements in glucose, LDL-c, IL-10, TNF-α, C-reactive protein, FOX, and AOPP concentrations in both training groups, without differences between them (p > 0.05). The results suggest that 12 weeks of RT, regardless of exercise order, elicit positive adaptations on body fat and metabolic biomarkers similarly in older women.

Depression, aging, and immunity: implications for COVID-19 vaccine immunogenicity

The aging process can have detrimental effects on the immune system rendering the elderly more susceptible to infectious disease and less responsive to vaccination. Major depressive disorder (MDD) has been hypothesized to show characteristics of accelerated biological aging. This raises the possibility that depressed individuals will show some overlap with elderly populations with respect to their immune response to infection and vaccination. Here we provide an umbrella review of this literature in the context of the SARS CoV-2 pandemic. On balance, the available data do indeed suggest that depression is a risk factor for both adverse outcomes following COVID-19 infection and for reduced COVID-19 vaccine immunogenicity. We conclude that MDD (and other major psychiatric disorders) should be recognized as vulnerable populations that receive priority for vaccination along with other at-risk groups.

Several areas of overlap between obesity and aging indicate obesity as a biomarker of accelerated aging of human B cell function and antibody responses

Aging and obesity are high risk factors for several conditions and diseases. They are both associated with systemic inflammation and they are both ameliorated by a healthy life style, suggesting that they may share cellular and molecular pathways and underlying mechanisms. A close relationship between aging and obesity is also supported by the observation that the aging overweight/obese population is increasing worldwide, and mechanisms involved will be presented here. A focus of our work is to evaluate if obesity may be considered a good biomarker of accelerated aging of human antibody responses. We will summarize our published results showing the effects of obesity in accelerating age defects in the peripheral B cell pool and how these lead to dysfunctional humoral immunity.

The Role of B Lymphocyte Subsets in Adipose Tissue Development, Metabolism, and Aging

Adipose tissue contains resident B lymphocytes (B cells) with varying immune functions and mechanisms, depending on the adipose depot type and location. The heterogeneity of B cells and their functions affect the immunometabolism of the adipose tissue in aging and age-associated metabolic disorders. B cells exist in categorizations of subsets that have developmental or phenotypic differences with varying functionalities. Subsets can be categorized as either protective or pathogenic depending on their secretion profile or involvement in metabolic maintenance. In this article, we summarized recent finding on the B cell heterogeneity and discuss how we can utilize our current knowledge of adipose resident B lymphocytes for potential treatment for age-associated metabolic disorders. © 2022 American Physiological Society. Compr Physiol 12: 1-13, 2022.

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.

Effects of Aging on Metabolic Characteristics of Human B Cells

ABSTRACT

Metabolic changes represent the most common sign of aging and lead to increased risk of developing diseases typical of old age. Age-associated metabolic changes, such as decreased insulin sensitivity, decreased mitochondrial function, and dysregulated nutrient uptake, fuel the low-grade chronic systemic inflammation, known as inflammaging, a leading cause of morbidity and mortality, linked to the development of several diseases of old age. How aging affects the metabolic phenotype of immune cells, and B cells in particular, is not well known and is under intensive investigation by several groups. In this study, we summarized the few published results linking intrinsic B-cell metabolism and B-cell function in different groups of young and elderly individuals: healthy, with type-2 diabetes mellitus, or with HIV infection. Although preliminary, these results suggest the intriguing possibility that metabolic pathways can represent potential novel therapeutic targets to reduce inflammaging and improve humoral immunity.

Mediterranean Diet and Fatty Liver Risk in a Population of Overweight Older Italians: A Propensity Score-Matched Case-Cohort Study

Hepatic steatosis, often known as fatty liver, is the most common hepatic disease in Western countries. The latest guidelines for the treatment of nonalcoholic fatty liver disease emphasize lifestyle measures, such as changing unhealthy eating patterns. Using a propensity score-matching approach, this study investigated the effect of adhering to a Mediterranean diet (MedDiet) on fatty liver risk in an older population (≥65 years) from Southern Italy. We recruited 1.403 subjects (53.6% men, ≥65 years) who completed a food frequency questionnaire (FFQ) and underwent clinical assessment between 2015 and 2018. For the assessment of the liver fat content, we applied the Fatty Liver Index (FLI). To evaluate the treatment effect of the MedDiet, propensity score matching was performed on patients with and without FLI > 60. After propensity score-matching with the MedDiet pattern as treatment, we found a higher consumption of red meat (p = 0.04) and wine (p = 0.04) in subjects with FLI > 60. Based on the FLI, the inverse association shown between adherence to the MedDiet and the risk of hepatic steatosis shows that the MedDiet can help to prevent hepatic steatosis. Consuming less red and processed meat, as well as alcoholic beverages, may be part of these healthy lifestyle recommendations.

Exercise Training Combined with Calanus Oil Supplementation Improves the Central Cardiodynamic Function in Older Women

The aim of this study was to investigate the possible beneficial effects of exercise training (ET) with omega-3/Calanus oil supplementation on cardiorespiratory and adiposity parameters in elderly women. Fifty-five women (BMI: 19–37 kg/m², 62–80 years old) were recruited and randomly assigned to the 4 month intervention with ET and omega-3 supplementation (Calanus oil, ET-Calanus) or ET and the placebo (sunflower oil; ET-Placebo). The body composition was determined by dual-energy X-ray absorptiometry (DXA), and cardiorespiratory parameters were measured using spiroergometry and PhysioFlow hemodynamic testing. Both interventions resulted in an increased lean mass whereas the fat mass was reduced in the leg and trunk as well as the android and gynoid regions. The content of trunk fat (in percent of the total fat) was lower and the content of the leg fat was higher in the ET-Calanus group compared with the ET-Placebo. Although both interventions resulted in similar improvements in cardiorespiratory fitness (VO_2max), it was explained by an increased peripheral oxygen extraction (a-vO₂diff) alone in the ET-Placebo group whereas increased values of both a-vO₂diff and maximal cardiac output (CO_max) were observed in the ET-Calanus group. Changes in CO_max were associated with changes in systemic vascular resistance, circulating free fatty acids, and the omega-3 index. In conclusion, Calanus oil supplementation during a 4 month ET intervention in elderly women improved the cardiorespiratory function, which was due to combined central and peripheral cardiodynamic mechanisms.

The Cross-Talk between Myeloid and Mesenchymal Stem Cells of Human Bone Marrow Represents a Biomarker of Aging That Regulates Immune Response and Bone Reabsorption

One of the mechanisms that characterizes the aging process of different organs is the accumulation of fat. Different authors have demonstrated that adipose tissue replaces the loss of other cell types, deriving from mesenchymal cells. During aging, there is substitution or trans-differentiation of mesenchymal cells with other cells having the same embryological origin. Newly formed adipocytes were also observed in the trabecular matrix of elderly people’s bones, associated with myeloid cells. In this study, we have investigated the relationship between immature myeloid-derived suppressor cells (I-MDSCs) and mesenchymal stem cells (MSCs) in bone marrow (BM) samples harvested from 57 patients subjected to different orthopedic surgeries. Patients aged from 18 to 92 years were considered in order to compare the cellular composition of bone marrow of young and elderly people, considered a biomarker of immunity, inflammation, and bone preservation. The I-MDSC percentage was stable during aging, but in elderly people, it was possible to observe a strong basal immunosuppression of autologous and heterologous T cells’ proliferation. We hypothesized that this pattern observed in elders depends on the progressive accumulation in the BM of activating stimuli, including cell–cell contact, or the production of different cytokines and proteins that induce the differentiation of bone marrow mesenchymal stem cells in adipocytes. The collected data provided underline the importance of specific biomarkers of aging that promote a reduction in immune response and incremented inflammatory pathways, leading to bone reabsorption in elderly people.

A Novel Age-Related Circular RNA Circ-ATXN2 Inhibits Proliferation, Promotes Cell Death and Adipogenesis in Rat Adipose Tissue-Derived Stromal Cells

Adipose tissue-derived stromal cells are promising candidates investigating the stem cell-related treatment. However, their proportion and utility in the human body decline with time, rendering stem cells incompetent to complete repair processes in vivo. The involvement of circRNAs in the aging process is poorly understood. Rat subcutaneous adipose tissue from 10-week-old and 27-month-old rats were used for hematoxylin and eosin (H and E) staining, TUNEL staining, and circRNA sequencing. Rat adipose tissue-derived stromal cells were cultured and overexpressed with circ-ATXN2. Proliferation was examined using xCELLigence real-time cell analysis, EdU staining, and cell cycle assay. Apoptosis was induced by CoCl2 and examined using flow cytometry. RT-PCR assay and Oil Red O staining were used to measure adipogenesis at 48 h and 14 days, respectively. H and E staining showed that the diameter of adipocytes increased; however, the number of cells decreased in old rats. TUNEL staining showed that the proportion of apoptotic cells was increased in old rats. A total of 4,860 and 4,952 circRNAs was detected in young and old rats, respectively. Among them, 67 circRNAs exhibited divergent expression between the two groups (fold change ≥2, p ≤ 0.05), of which 33 were upregulated (49.3%) and 34 were downregulated (50.7%). The proliferation of circ-ATXN2-overexpressing cells decreased significantly in vitro, which was further validated by xCELLigence real-time cell analysis, EdU staining, and cell cycle assay. Overexpression of circ-ATXN2 significantly increased the total apoptotic rate from 5.78 ± 0.46% to 11.97 ± 1.61%, early apoptotic rate from 1.76 ± 0.22% to 5.50 ± 0.66%, and late apoptosis rate from 4.02 ± 0.25% to 6.47 ± 1.06% in adipose tissue-derived stromal cells. Furthermore, in circ-ATXN2-overexpressing cells, RT-PCR assay revealed that the expression levels of adipose differentiation-related genes PPARγ and CEBP/α were increased and the Oil Red O staining assay showed more lipid droplets. Our study revealed the expression profile of circRNAs in the adipose tissue of old rats. We found a novel age-related circular RNA—circ-ATXN2—that inhibits proliferation and promotes cell death and adipogenesis in rat adipose tissue-derived stromal cells.

Aging, obesity, sarcopenia and the effect of diet and exercise intervention

The number of adults 65 years and older is increasing worldwide and will represent the 20% of the population by 2030. Half of them will suffer from obesity. The decline in muscle mass and strength, known as sarcopenia, is very common among older adults with obesity (sarcopenic obesity). Sarcopenic obesity is strongly associated with frailty, cardiometabolic dysfunction, physical disability, and mortality. Increasing efforts have been hence made to identify effective strategies able to promote healthy aging and curb the obesity pandemic. Among these, lifestyle interventions consisting of diet and exercise protocols have been extensively explored. Importantly, diet-induced weight loss is associated with fat, muscle, and bone mass losses, and may further exacerbate age-related sarcopenia and frailty outcomes in older adults. Successful approaches to induce fat mass loss while preserving lean and bone mass are critical to reduce the aging- and obesity-related physical and metabolic complications and at the same time ameliorate frailty. In this review article, we discuss the most recent evidence on the age-related alterations in adipose tissue and muscle health and on the effect of calorie restriction and exercise approaches for older adults with obesity and sarcopenia, emphasizing the existing gaps in the literature that need further investigation.

Senescence of donor cells impairs fat graft regeneration by suppressing adipogenesis and increasing expression of senescence-associated secretory phenotype factors

Background

Fat grafting has been regarded as a promising approach for regenerative therapy. Given the rapidly aging population, better understanding of the effect of age on fat graft outcomes and the underlying mechanisms is urgently needed.

Methods

C57/BL6 mice [old (O, 18–20-month-old) and young (Y, 4-month-old)] were randomized to four fat graft groups [old-to-old (O-O), young-to-young (Y-Y), old-to-young (O-Y), and young-to-old (Y-O)]. Detailed cellular events before and after grafting were investigated by histological staining, RNA sequencing, and real-time polymerase chain reaction. The adipogenic differentiation potential of adipose-derived mesenchymal stem cells (AD-MSCs) from old or young donors was investigated in vitro. Additionally, adipogenesis of AD-MSCs derived from old recipients was evaluated in the culture supernatant of old or young donor fat tissue.

Results

After 12 weeks, the volume of fat grafts did not significantly differ between the O-O and O-Y groups or between the Y-Y and Y-O groups, but was significantly smaller in the O-O group than in the Y-O group and in the O-Y group than in the Y-Y group. Compared with fat tissue from young mice, senescence-associated secretory phenotype (SASP) factors were upregulated in fat tissue from old mice. Compared with the Y-O group, adipogenesis markers were downregulated in the O-O group, while SASP factors including interleukin (IL)-6, tumor necrosis factor-α, and IL-1β were upregulated. In vitro, AD-MSCs from old donors showed impaired adipogenesis compared with AD-MSCs from young donors. Additionally, compared with the culture supernatant of young donor fat tissue, the culture supernatant of old donor fat tissue significantly decreased adipogenesis of AD-MSCs derived from old recipients, which might be attributable to increased levels of SASP factors.

Conclusions

Age has detrimental effects on fat graft outcomes by suppressing adipogenesis of AD-MSCs and upregulating expression of SASP factors, and fat graft outcomes are more dependent on donor age than on recipient age. Thus, rejuvenating fat grafts from old donors or banking younger adipose tissue for later use may be potential approaches to improve fat graft outcomes in older adults.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-021-02383-w.

Comparision of Low and High Volume of Resistance Training on Body Fat and Blood Biomarkers in Untrained Older Women: A Randomized Clinical Trial

ABSTRACT

Cunha, PM, Tomeleri, CM, Nascimento, MA, Mayhew, JL, Fungari, E, Cyrino, LT, Barbosa, DS, Venturini, D, and Cyrino, ES. Comparision of low and high volume of resistance training on body fat and blood biomarkers in untrained older women: a randomized clinical trial. J Strength Cond Res 35(1): 1-8, 2021-The purpose of this study was to compare the effects of resistance training (RT) performed with 2 different volumes on body fat and blood biomarkers in untrained older women. Sixty-five physically independent older women (≥60 years) were randomly assigned to one of 3 groups: low-volume (LV) training group, high-volume (HV) training group, and a control group. Both training groups performed RT for 12 weeks, using 8 exercises of 10-15 repetitions maximum for each exercise. The low-volume group performed only a single set per exercise, whereas the HV group performed 3 sets. Anthropometric, body fat (%), trunk fat, triglycerides (TG), total cholesterol, low-density lipoprotein cholesterol (LDL-c), high-density lipoprotein cholesterol, very LDL-c (VLDL-c), glucose (GLU), C-reactive protein (CRP), and composite Z-score were measured. The HV group obtained greater improvements compared with the LV group (p < 0.05) for TG (LV = -10.5% vs. HV = -16.6%), VLDL-c (LV = -6.5% vs. HV = -14.8%), GLU (LV = -4.7% vs. HV = -11.1%), CRP (LV = -13.2% vs. HV = -30.8%), % body fat (LV = -2.4% vs. HV = -6.1%), and composite Z-score (LV = -0.13 ± 0.30 vs. HV = -0.57 ± 0.29). Trunk fat was reduced (p < 0.05) only in the HV group (-6.8%). We conclude that RT performed in higher volume seems to be the most appropriate strategy to reduce body fat (%), trunk fat, improve blood biomarkers, and reduce composite Z-score in older women.

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.

Phenotypic and Functional Characterization of Double Negative B Cells in the Blood of Individuals With Obesity

We have previously shown that obesity is associated with increased secretion of IgG antibodies with anti-self-reactivity. In this paper, we confirm and extend our previous findings. We show that the plasma of individuals with obesity is enriched in autoimmune antibodies whose levels are positively associated with blood frequencies of the subset of Double Negative (DN) B cells, which is the most pro-inflammatory B cell subset. We also show that DN B cells, significantly increased in the blood of obese versus lean individuals, are characterized by higher expression of immune activation markers and of the transcription factor T-bet, both associated with autoimmunity. The removal of DN B cells from the peripheral B cell pool significantly decreases in vitro secretion of anti-self IgG antibodies. These results altogether confirm the crucial role of DN B cells in the secretion of anti-self IgG antibodies in individuals with obesity.

How does adipose tissue contribute to inflammageing?

Across aging, white adipose tissue (WAT) undergoes significant changes in quantity and distribution, with an increase in visceral adipose tissue, ectopic fat deposition and a decline in gluteofemoral subcutaneous depot. In particular, WAT becomes dysfunctional with an increase in production of inflammatory peptides and a decline of those with anti-inflammatory activity and infiltration of inflammatory cells. Moreover, dysfunction of WAT is characterized by preadipocyte differentiation decline, increased oxidative stress and mitochondrial dysfunction, reduction in vascularization and hypoxia, increased fibrosis and senescent cell accumulation. WAT changes represent an important hallmark of the aging process and may be responsible for the systemic pro-inflammatory state ("inflammageing") typical of aging itself, leading to age-related metabolic alterations. This review focuses on mechanisms linking age-related WAT changes to inflammageing.

Aging induces B cell defects and decreased antibody responses to influenza infection and vaccination

Background

Aging is characterized by a progressive decline in the capacity of the immune system to fight influenza virus infection and to respond to vaccination. Among the several factors involved, in addition to increased frailty and high-risk conditions, the age-associated decrease in cellular and humoral immune responses plays a relevant role. This is in large part due to inflammaging, the chronic low-grade inflammatory status of the elderly, associated with intrinsic inflammation of the immune cells and decreased immune function.

Results

Aging is usually associated with reduced influenza virus-specific and influenza vaccine-specific antibody responses but some elderly individuals with higher pre-exposure antibody titers, due to a previous infection or vaccination, have less probability to get infected. Examples of this exception are the elderly individuals infected during the 2009 pandemic season who made antibodies with broader epitope recognition and higher avidity than those made by younger individuals. Several studies have allowed the identification of B cell intrinsic defects accounting for sub-optimal antibody responses of elderly individuals. These defects include 1) reduced class switch recombination, responsible for the generation of a secondary response of class switched antibodies, 2) reduced de novo somatic hypermutation of the antibody variable region, 3) reduced binding and neutralization capacity, as well as binding specificity, of the secreted antibodies, 4) increased epigenetic modifications that are associated with lower antibody responses, 5) increased frequencies of inflammatory B cell subsets, and 6) shorter telomeres.

Conclusions

Although influenza vaccination represents the most effective way to prevent influenza infection, vaccines with greater immunogenicity are needed to improve the response of elderly individuals. Recent advances in technology have made possible a broad approach to better understand the age-associated changes in immune cells, needed to design tailored vaccines and effective therapeutic strategies that will be able to improve the immune response of vulnerable individuals.

Dysregulated Autophagy Mediates Sarcopenic Obesity and Its Complications via AMPK and PGC1α Signaling Pathways: Potential Involvement of Gut Dysbiosis as a Pathological Link

Sarcopenic obesity (SOB), which is closely related to being elderly as a feature of aging, is recently gaining attention because it is associated with many other age-related diseases that present as altered intercellular communication, dysregulated nutrient sensing, and mitochondrial dysfunction. Along with insulin resistance and inflammation as the core pathogenesis of SOB, autophagy has recently gained attention as a significant mechanism of muscle aging in SOB. Known as important cellular metabolic regulators, the AMP-activated protein kinase (AMPK) and the peroxisome proliferator-activated receptor-gamma coactivator-1 alpha (PGC-1α) signaling pathways play an important role in autophagy, inflammation, and insulin resistance, as well as mutual communication between skeletal muscle, adipose tissue, and the liver. Furthermore, AMPK and PGC-1α signaling pathways are implicated in the gut microbiome-muscle axis. In this review, we describe the pathological link between SOB and its associated complications such as metabolic, cardiovascular, and liver disease, falls and fractures, osteoarthritis, pulmonary disease, and mental health via dysregulated autophagy controlled by AMPK and/or PGC-1α signaling pathways. Here, we propose potential treatments for SOB by modulating autophagy activity and gut dysbiosis based on plausible pathological links.

Obesity Accelerates Age Defects in Mouse and Human B Cells

Obesity, similar to aging, is associated with chronic low-grade systemic inflammation, known as inflammaging, and represents a significantly higher risk for developing chronic diseases typical of old age. Immune cells are recruited to the obese adipose tissue (AT) by chemotactic molecules secreted by non-immune and immune cells in the AT, both contributing to the release of several pro-inflammatory mediators that fuel local and systemic inflammation, to the refractory response of immune cells to further in vivo and in vitro stimulation and to the induction of autoimmune B cells with potentially pathogenic repertoires. In terms of molecular mechanisms involved, leptin, an adipokine secreted primarily by adipocytes, has been proposed to be involved in the reduced generation of protective antibodies, and in the increased generation of autoimmune antibodies, further supporting the concept that obesity accelerates age defects. Leptin has also been shown to induce intrinsic B cell inflammation and B cell immunosenescence. The results presented in this review highlight the importance of weight reduction programs to improve immunity and reduce the risk for developing chronic diseases in obese and older individuals.

Adipose tissue, immune aging, and cellular senescence

Obesity represents a serious health problem as it is rapidly increasing worldwide. Obesity is associated with reduced healthspan and lifespan, decreased responses to infections and vaccination, and increased frequency of inflammatory conditions typical of old age. Obesity is characterized by increased fat mass and remodeling of the adipose tissue (AT). In this review, we summarize published data on the different types of AT present in mice and humans, and their roles as fat storage as well as endocrine and immune tissues. We review the age-induced changes, including those in the distribution of fat in the body, in abundance and function of adipocytes and their precursors, and in the infiltration of immune cells from the peripheral blood. We also show that cells with a senescent-associated secretory phenotype accumulate in the AT of mice and humans with age, where they secrete several factors involved in the establishment and maintenance of local inflammation, oxidative stress, cell death, tissue remodeling, and infiltration of pro-inflammatory immune cells. Not only adipocytes and pre-adipocytes but also immune cells show a senescent phenotype in the AT. With the increase in human lifespan, it is crucial to identify strategies of intervention and target senescent cells in the AT to reduce local and systemic inflammation and the development of age-associated diseases. Several studies have indeed shown that senescent cells can be effectively targeted in the AT by selectively removing them or by inhibiting the pathways that lead to the secretion of pro-inflammatory factors.

Pharmacological Interactions in the Elderly

Pharmacological therapy in the elderly is particularly complicated and challenging. Due to coexistence of three main predisposing factors (advanced age, multiple morbidity and polypharmacotherapy), this group of patients is prone to occurrence of drug interactions and adverse effects of incorrect drug combinations. Since many years patient safety during the treatment process has been one of key elements for proper functioning of healthcare systems around the world, thus different preventive measures have been undertaken in order to counteract factors adversely affecting the therapeutic effect. One of the avoidable medical errors is pharmacological interactions. According to estimates, one in six elderly patients may be at risk of a significant drug interaction. Hence the knowledge about mechanisms and causes of drug interactions in the elderly, as well as consequences of their occurrence are crucial for planning the process of pharmacotherapy. For the purpose of pharmacovigilance, a review of available methods and tools gives an insight into possible ways of preventing drug interactions. Additionally, recognizing the actual scale of this phenomenon in geriatric population around the world emphasizes the importance of a joint effort among medical community to improve quality of pharmacotherapy.

Age-related factors that affect B cell responses to vaccination in mice and humans

Aging significantly changes the ability to respond to vaccinations and infections. In this review, we summarize published results on age-related changes in response to infection with the influenza virus and on the factors known to increase influenza risk infection leading to organ failure and death. We also summarize how aging affects the response to the influenza vaccine with a special focus on B cells, which have been shown to be less responsive in the elderly. We show the cellular and molecular mechanisms contributing to the dysfunctional immune response of the elderly to the vaccine against influenza. These include a defective interaction of helper T cells (CD4+) with B cells in germinal centers, changes in the microenvironment, and the generation of immune cells with a senescence-associated phenotype. Finally, we discuss the effects of aging on metabolic pathways and we show how metabolic complications associated with aging lead to immune dysfunction.

Moderation of mitochondrial respiration mitigates metabolic syndrome of aging

Deregulation of mitochondrial dynamics leads to the accumulation of oxidative stress and unhealthy mitochondria; consequently, this accumulation contributes to premature aging and alterations in mitochondria linked to metabolic complications. We postulate that restrained mitochondrial ATP synthesis might alleviate age-associated disorders and extend healthspan in mammals. Herein, we prepared a previously discovered mitochondrial complex IV moderate inhibitor in drinking water and orally administered to standard-diet-fed, wild-type C57BL/6J mice every day for up to 16 mo. No manifestation of any apparent toxicity or deleterious effect on studied mouse models was observed. The impacts of an added inhibitor on a variety of mitochondrial functions were analyzed, such as respiratory activity, mitochondrial bioenergetics, and biogenesis, and a few age-associated comorbidities, including reactive oxygen species (ROS) production, glucose abnormalities, and obesity in mice. It was found that mitochondrial quality, dynamics, and oxidative metabolism were greatly improved, resulting in lean mice with a specific reduction in visceral fat plus superb energy and glucose homeostasis during their aging period compared to the control group. These results strongly suggest that a mild interference in ATP synthesis through moderation of mitochondrial activity could effectively up-regulate mitogenesis, reduce ROS production, and preserve mitochondrial integrity, thereby impeding the onset of metabolic syndrome. We conclude that this inhibitory intervention in mitochondrial respiration rectified the age-related physiological breakdown in mice by protecting mitochondrial function and markedly mitigated certain undesired primary outcomes of metabolic syndrome, such as obesity and type 2 diabetes. This intervention warrants further research on the treatment of metabolic syndrome of aging in humans.

Dietary Fibre May Mitigate Sarcopenia Risk: Findings from the NU-AGE Cohort of Older European Adults

Sarcopenia is characterised by a progressive loss of skeletal muscle mass and physical function as well as related metabolic disturbances. While fibre-rich diets can influence metabolic health outcomes, the impact on skeletal muscle mass and function is yet to be determined, and the moderating effects by physical activity (PA) need to be considered. The aim of the present study was to examine links between fibre intake, skeletal muscle mass and physical function in a cohort of older adults from the NU-AGE study. In 981 older adults (71 ± 4 years, 58% female), physical function was assessed using the short-physical performance battery test and handgrip strength. Skeletal muscle mass index (SMI) was derived using dual-energy X-ray absorptiometry (DXA). Dietary fibre intake (FI) was assessed by 7-day food record and PA was objectively determined by accelerometery. General linear models accounting for covariates including PA level, protein intake and metabolic syndrome (MetS) were used. Women above the median FI had significantly higher SMI compared to those below, which remained in fully adjusted models (24.7 ± 0.2% vs. 24.2 ± 0.1%, p = 0.011, η²p = 0.012). In men, the same association was only evident in those without MetS (above median FI: 32.4 ± 0.3% vs. below median FI: 31.3 ± 0.3%, p = 0.005, η²p = 0.035). There was no significant impact of FI on physical function outcomes. The findings from this study suggest a beneficial impact of FI on skeletal muscle mass in older adults. Importantly, this impact is independent of adherence to guidelines for protein intake and PA, which further strengthens the potential role of dietary fibre in preventing sarcopenia. Further experimental work is warranted in order to elucidate the mechanisms underpinning the action of dietary fibre on the regulation of muscle mass.

Impaired B Cell Function in Mice Lacking Perforin-2

Perforin-2 (P2) is a pore-forming protein with cytotoxic activity against intracellular bacterial pathogens. P2 knockout (P2KO) mice are unable to control infections and die from normally non-lethal bacterial infections. Here we show that P2KO mice as compared to WT mice show significantly higher levels of systemic inflammation, measured by inflammatory markers in serum, due to continuous microbial translocation from the gut which cannot be controlled as these mice lack P2. Systemic inflammation in young and old P2KO mice induces intrinsic B cell inflammation. Systemic and B cell intrinsic inflammation are negatively associated with in vivo and in vitro antibody responses. Chronic inflammation leads to class switch recombination defects, which are at least in part responsible for the reduced in vivo and in vitro antibody responses in young and old P2KO vs. WT mice. These defects include the reduced expression of activation-induced cytidine deaminase (AID), the enzyme for class switch recombination, somatic hypermutation and IgG production and of its transcriptional activators E47 and Pax5. Of note, the response of young P2KO mice is not different from the one observed in old WT mice, suggesting that the chronic inflammatory status of mice lacking P2 may accelerate, or be equivalent, to that seen in old mice. The inflammatory status of the splenic B cells is associated with increased frequencies and numbers of the pro-inflammatory B cell subset called Age-associated B Cells (ABCs) in the spleen and the visceral adipose tissue (VAT) of P2KO old mice. We show that B cells differentiate into ABCs in the VAT following interaction with the adipocytes and their products, and this occurs more in the VAT of P2KO mice as compared to WT controls. This is to our knowledge the first study on B cell function and antibody responses in mice lacking P2.

The level of physical activity as an intervening factor in the cognitive state of primary care older adults

This study proposed to evaluate the level of physical activity and the cognitive state of elderly users of Primary Care Facilities (UBS) of the Municipality of Maringá, State of Paraná, Brazil. This is a descriptive, cross-sectional, epidemiological study with 654 elderly men and women UBS users. A sociodemographic questionnaire, the Mini Mental State Examination (MMSE) and the short version of the International Physical Activity Questionnaire (IPAQ) were employed. Data was analyzed using the Kolmogorov-Smirnov, Chi-square, Kruskal-Wallis and Mann-Whitney "U" tests, with a significance level of p<0.05. However, they evidenced a high score in temporal orientation (Md = 5.0), spatial orientation (Md = 5.0), immediate memory (Md = 3.0), recall (Md = 3.0) and language (Md = 8.0). When comparing the mental state according to the level of physical activity of the elderly, we observed that very active/active individuals had better attention and calculation (p = 0.036), recall (p = 0.001) and general cognitive status (p = 0.002) against irregularly active and sedentary elderly. Adequate levels of physical activity may be related to better scores of cognitive functions of elderly subjects.

Inflamm-Aging Is Associated with Lower Plasma PTX3 Concentrations and an Impaired Capacity of PBMCs to Express hTERT following LPS Stimulation

Age-related elevations in proinflammatory cytokines, known as inflamm-aging, are associated with shorter immune cell telomere lengths. Purpose. This study examined the relationship of plasma PTX3 concentrations, a biomarker of appropriate immune function, with telomere length in 15 middle-aged (40-64 years) and 15 young adults (20-31 years). In addition, PBMCs were isolated from middle-aged and young adults to examine their capacity to express a key mechanistic component of telomere length maintenance, human telomerase reverse transcriptase (hTERT), following ex vivo cellular stimulation. Methods. Plasma PTX3 and inflammatory cytokines (i.e., IL-6, IL-10, TGF-β, and TNF-α), PBMC telomere lengths, and PBMC hTERT gene expression and inflammatory protein secretion following exposure to LPS, PTX3, and PTX3+LPS were measured. Results. Aging was accompanied by the accumulation of centrally located visceral adipose tissue, without changes in body weight and BMI, and alterations in the systemic inflammatory milieu (decreased plasma PTX3 and TGF-β; increased TNF-α (p ≤ 0.050)). In addition, shorter telomere lengths in middle-aged compared to young adults (p = 0.011) were negatively associated with age, body fat percentages, and plasma TNF-α (r = -0.404, p = 0.027; r = -0.427, p = 0.019; and r = -0.323, p = 0.041, respectively). Finally, the capacity of PBMCs to increase hTERT gene expression following ex vivo stimulation was impaired in middle-aged compared to young adults (p = 0.033) and negatively associated with telomere lengths (r = 0.353, p = 0.028). Conclusions. Proinflammation and the impaired hTERT gene expression capacity of PBMCs may contribute to age-related telomere attrition and disease.

Adipose Tissue: A Tertiary Lymphoid Organ: Does It Change with Age?

In this manuscript, we summarize published results showing that obesity and aging are inflammatory conditions associated with serious health problems, increased risk for disease and death. We show that fat mass increases with age and represents a major contributor to insulin resistance and the metabolic syndrome. We summarize the effects of age on the adipose tissue (AT), related to the abundance, distribution, cellular composition, endocrine signaling and function of the tissue. The AT is an immunological tissue, with several hallmarks of innate and adaptive immune responses. We show that in both mice and humans, the AT is heavily infiltrated by immune cells that have receptors for pro-inflammatory cytokines and chemokines secreted by the adipocytes and also by the immune cells that have infiltrated the AT. We also show that the AT provides an environment for the secretion of IgG antibodies with anti-self (autoimmune) reactivity. As we have previously shown, this is due to the release of self antigens following cell death due to hypoxia, as well as to the expression of activation-induced cytidine deaminase, the enzyme of class switch recombination, and the transcription factor T-bet by the resident B cells, which also express the membrane marker CD11c, both involved in the production of autoimmune IgG antibodies. We show data in support of the AT as a tertiary lymphoid organ (TLO), showing the examples of TLOs that develop within the AT, such as fat-associated lymphoid clusters and milky spots, as well as artery TLOs that develop in the adventitia areas of the aorta.

Metabolic requirements of human pro-inflammatory B cells in aging and obesity

The subset of pro-inflammatory B cells, called late memory, tissue-like or double negative (DN), accumulates in the blood of elderly individuals. Here we show that DN B cells do not proliferate and do not make antibodies to influenza antigens, but they secrete antibodies with autoimmune reactivity, in agreement with their membrane phenotype (CD95+CD21-CD11c+) and their spontaneous expression of the transcription factor T-bet. These cells also increase in the blood of individuals with obesity and autoimmune diseases, but causative mechanisms and signaling pathways involved are known only in part. In the present paper we compare frequencies and metabolic requirements of these cells in the blood of healthy individuals of different ages and in the blood and the subcutaneous adipose tissue (SAT) of individuals with obesity. Results show that DN B cells from young individuals have minimal metabolic requirements, DN B cells from elderly and obese individuals utilize higher amounts of glucose to perform autoimmune antibody production and enroll in aerobic glycolysis to support their function. DN B cells from the SAT have the highest metabolic requirements as they activate oxidative phosphorylation, aerobic glycolysis and fatty acid oxidation. DN B cells from the SAT also show the highest levels of ROS and the highest levels of phosphorylated AMPK (5'-AMP activated kinase) and Sestrin 1, both able to mitigate stress and cell death. This metabolic advantage drives DN B cell survival and function (secretion of autoimmune antibodies).

Histologic analysis and lipid profiling reveal reproductive age-associated changes in peri-ovarian adipose tissue

BACKGROUND

Reproductive aging is a robust phenotype that occurs in all females and is characterized by a significant reduction in gamete quantity and quality, which can have negative consequences on both endocrine function and fertility. Age-associated differences in the oocyte, follicle, and ovary have been well-documented, but how the broader environment changes with age is less well understood. Fat is one of the largest organs in the body, and peri-gonadal adipose tissue surrounds the rodent ovary and comprises a local ovarian environment. The goal of this study was to characterize how peri-ovarian adipose tissue changes with advanced reproductive age.

METHODS

We isolated peri-gonadal adipose tissue from two cohorts of CB6F1 mice: reproductively young (6-12 weeks) and reproductively old (14-17 months). A comparative histological analysis was performed to evaluate adipocyte architecture. We then extracted lipids from the tissue and performed multiple reaction monitoring (MRM)-profiling, a mass spectrometry-based method of metabolite profiling, to compare the lipid profiles of peri-gonadal adipose tissue in these age cohorts.

RESULTS

We found that advanced reproductive age was associated with adipocyte hypertrophy and a corresponding decrease in the number of adipocytes per area. Of the 10 lipid classes examined, triacylglycerols (TAGs) had significantly different profiles between young and old cohorts, despite quantitative analysis revealing a decrease in the total amount of TAGs per weight of peri-gonadal adipose tissue with age.

CONCLUSIONS

These findings pinpoint age-associated physiological changes in peri-gonadal adipose tissue with respect to adipocyte morphology and lipid profiles and lay the foundation for future studies to examine how these alterations may influence both adipocyte and ovarian function.

Implications of Aging in Plastic Surgery

Given the rapidly aging population, investigating the effect of age on plastic surgery outcomes is imperative. Despite this, the topic has received relatively little attention. Furthermore, there appears to be little integration between the basic scientists investigating the mechanisms of aging and the plastic surgeons providing the majority of "antiaging" therapies. This review first provides a description of the effects and mechanisms of aging in 5 types of tissue: skin, adipose tissue, muscles, bones and tendons, and nervous tissue followed by an overview of the basic mechanisms underlying aging, presenting the currently proposed cellular and molecular theories. Finally, the impact of aging, as well as frailty, on plastic surgery outcomes is explored by focusing on 5 different topics: general wound healing and repair of cutaneous tissue, reconstruction of soft tissue, healing of bones and tendons, healing of peripheral nerves, and microsurgical reconstruction. We find mixed reports on the effect of aging or frailty on outcomes in plastic surgery, which we hypothesize to be due to exclusion of aged and frail patients from surgery as well as due to outcomes that reported no postsurgical issues with aged patients. As plastic surgeons continue to interact more with the growing elderly population, a better appreciation of the underlying mechanisms and outcomes related to aging and a clear distinction between chronological age and frailty can promote better selection of patients, offering appropriate patients surgery to improve an aged appearance, and declining interventions in inappropriate patients.