Inflammaging 2018: An update and a model

COVID-19 mortality in Lombardy: the vulnerability of the oldest old and the resilience of male centenarians

Italy was the first European nation to be affected by COVID-19. The biggest cluster of cases occurred in Lombardy, the most populous Italian region, and elderly men were the population hit in the hardest way. Besides its high infectivity, COVID-19 causes a severe cytokine storm and old people, especially those with comorbidities, appear to be the most vulnerable, presumably in connection to inflammaging. In centenarians inflammaging is much lower than predicted by their chronological age and females, presenting survival advantage in almost all centenarian populations, outnumber males, a phenomenon particularly evident in Northern Italy. Within this scenario, we wondered if: a) the COVID-19 mortality in centenarians was lower than that in people aged between 50 and 80 and b) the mortality from COVID-19 in nonagenarians and centenarians highlighted gender differences.

We checked COVID-19-related vulnerability/mortality at the peak of infection (March 2020), using data on total deaths (i.e. not only confirmed COVID-19 cases). Our conclusion is that excess mortality increases steadily up to very old ages and at the same time men older than 90 years become relatively more resilient than age-matched females.

[Biotherapies in elderly patients]

The ageing of the population leads health professionals to question the tolerance and the effectiveness of the different biotherapies used in autoimmune diseases. Due to the exponential increase of biotherapies and their indications, several studies have been carried out to evaluate their impact on elderly patients suffering from autoimmune disease. However, these studies are still too few to take into account all the different specificities of elderly patients and their comorbidities; prescribers are therefore hesitant with their introduction after 75 years or even 65. More than the age of patients, it is necessary to evaluate the comorbidities before introducing this kind of treatments. Every biotherapy has different indications and contraindications, which must be known to adapt each treatment to each patient. This focus aims to remind of the adaptations and contraindications of the different biological disease-modifying anti-rheumatic drugs for geriatric population, and improve their uses since the treatments for these patients are sometimes not enough. Here we resume the methods allowing supervisors to identify errors of clinical reasoning in medical students and interns and we explain remediation techniques adapted to the types of error identified. Access to short illustrative videos of a MOOC (Massive Open On line Course) devoted to the supervision of clinical reasoning constitutes practical help for supervisors who are not expert in the complexity of medical pedagogy at the bedside.

Neurovascular Inflammaging in Health and Disease

Aging is characterized by a chronic low-grade sterile inflammation dubbed as inflammaging, which in part originates from accumulating cellular debris. These, acting as danger signals with many intrinsic factors such as cytokines, are sensed by a network of pattern recognition receptors and other cognate receptors, leading to the activation of inflammasomes. Due to the inflammasome activity-dependent increase in the levels of pro-inflammatory interleukins (IL-1β, IL-18), inflammation is initiated, resulting in tissue injury in various organs, the brain and the spinal cord included. Similarly, in age-related diseases of the central nervous system (CNS), inflammasome activation is a prominent moment, in which cells of the neurovascular unit occupy a significant position. In this review, we discuss the inflammatory changes in normal aging and summarize the current knowledge on the role of inflammasomes and contributing mechanisms in common CNS diseases, namely Alzheimer’s disease, Parkinson’s disease, amyotrophic lateral sclerosis and stroke, all of which occur more frequently with aging.

Epigenetic insights into multiple sclerosis disease progression

Multiple sclerosis (MS), a chronic inflammatory demyelinating and neurodegenerative disease of the central nervous system, is today a leading cause of unpredictable lifelong disability in young adults. The treatment of patients in progressive stages remains highly challenging, alluding to our limited understanding of the underlying pathological processes. In this review, we provide insights into the mechanisms underpinning MS progression from a perspective of epigenetics, that refers to stable and mitotically heritable, yet reversible, changes in the genome activity and gene expression. We first recapitulate findings from epigenetic studies examining the brain tissue of progressive MS patients, which support a contribution of DNA and histone modifications in impaired oligodendrocyte differentiation, defective myelination/remyelination and sustained neuro-axonal vulnerability. We next explore possibilities for identifying factors affecting progression using easily accessible tissues such as blood by comparing epigenetic signatures in peripheral immune cells and brain tissue. Despite minor overlap at individual methylation sites, nearly 30% of altered genes reported in peripheral immune cells of progressive MS patients were found in brain tissue, jointly converging on alterations of neuronal functions. We further speculate about the mechanisms underlying shared epigenetic patterns between blood and brain, which likely imply the influence of internal (genetic control) and/or external (e.g. smoking and ageing) factors imprinting a common signature in both compartments. Overall, we propose that epigenetics might shed light on clinically relevant mechanisms involved in disease progression and open new avenues for the treatment of progressive MS patients in the future.

Does Calorie Restriction Modulate Inflammaging via FoxO Transcription Factors?

Calorie restriction (CR) has been shown to extend lifespan and retard aging-related functional decline in animals. Previously, we found that the anti-neoplastic and lifespan-extending effects of CR in mice are regulated by forkhead box O transcription factors (FoxO1 and FoxO3), located downstream of growth hormone (GH)–insulin-like growth factor (IGF)-1 signaling, in an isoform-specific manner. Inflammaging is a term coined to represent that persistent low-level of inflammation underlies the progression of aging and related diseases. Attenuation of inflammaging in the body may underlie the effects of CR. Recent studies have also identified cellular senescence and activation of the nucleotide-binding domain, leucine-rich-containing family, pyrin-domain-containing-3 (NLRP3) inflammasome as causative factors of inflammaging. In this paper, we reviewed the current knowledge of the molecular mechanisms linking the effects of CR with the formation of inflammasomes, particularly focusing on possible relations with FoxO3. Inflammation in the brain that affects adult neurogenesis and lifespan was also reviewed as evidence of inflammaging. A recent progress of microRNA research was described as regulatory circuits of initiation and propagation of inflammaging. Finally, we briefly introduced our preliminary results obtained from the mouse models, in which Foxo1 and Foxo3 genes were conditionally knocked out in the myeloid cell lineage.

Defining the vulnerable patient with myeloma-a frailty position paper of the European Myeloma Network

As the treatment landscape continues to evolve towards the application of precision medicine in multiple myeloma (MM), there is a clear need to identify those patients who are at risk of not achieving the maximum benefit whilst exposed to the highest level of toxicity. This group of patients, defined as frail, is an unmet clinical need. However, how we define such a vulnerable group of patients with MM remains to be clarified. An integral aspect of this is to define the physiological age and capacity of patients with MM to deal with the burden of their disease and it's treatment. Such assessments may include not only functional and clinical assessments but also laboratory-based biomarkers of frailty, aging and senescent cellular burden. A need to develop, test and validate clinical screening scores before their adoption into clinical practice is mandated. This position paper from the European Myeloma Network aims to review what is known about defining frailty in MM, and how we can advance this knowledge for the design of clinical trials and ultimately how we deliver treatment in the clinic.

Inflamm-aging: Why older men are the most susceptible to SARS-CoV-2 complicated outcomes

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is characterized by a high mortality of elderly men with age-related comorbidities. In most of these patients, uncontrolled local and systemic hyperinflammation induces severe and often lethal outcomes. The aging process is characterized by the gradual development of a chronic subclinical systemic inflammation (inflamm-aging) and by acquired immune system impairment (immune senescence). Here, we advance the hypothesis that four well-recognized features of aging contribute to the disproportionate SARS-CoV-2 mortality suffered by elderly men: i. the presence of subclinical systemic inflammation without overt disease, ii. a blunted acquired immune system and type I interferon response due to the chronic inflammation; iii. the downregulation of ACE2 (i.e. the SARS-CoV-2 receptor); and iv. accelerated biological aging. The high mortality rate of SARS-CoV-2 infection suggests that clarification of the mechanisms of inflamm-aging and immune senescence can help combat not only age-related disorders but also SARS-CoV-2 infection.

Compromised steady-state germinal center activity with age in nonhuman primates

Age-related reductions in vaccine-induced B cells in aging indicate that germinal centers (GCs), the anatomical site where the development of humoral responses takes place, may lose efficacy with age. We have investigated the baseline follicular and GC composition in nonhuman primates (NHPs) with respect to their age. There was a marked reduction in follicular area in old animals. We found significantly lower normalized numbers of follicular PD1hi CD4 T (Tfh) and proliferating (Ki67hi ) GC B cells with aging, a profile associated with significantly higher numbers of potential follicular suppressor FoxP3hi Lag3hi CD4 T cells. Furthermore, a positive correlation was found between Tfh and follicular CD8 T cells (fCD8) only in young animals. Despite the increased levels of circulating preinflammatory factors in aging, young animals had higher numbers of monocytes and granulocytes in the follicles, a profile negatively associated with numbers of Tfh cells. Multiple regression analysis showed an altered association between GC B cells and other GC immune cell populations in old animals suggesting a differential mechanistic regulation of GC activity in aging. Our data demonstrate defective baseline GC composition in old NHPs and provide an immunological base for further understanding the adaptive humoral responses with respect to aging.

Contributions of Age-Related Thymic Involution to Immunosenescence and Inflammaging

Immune system aging is characterized by the paradox of immunosenescence (insufficiency) and inflammaging (over-reaction), which incorporate two sides of the same coin, resulting in immune disorder. Immunosenescence refers to disruption in the structural architecture of immune organs and dysfunction in immune responses, resulting from both aged innate and adaptive immunity. Inflammaging, described as a chronic, sterile, systemic inflammatory condition associated with advanced age, is mainly attributed to somatic cellular senescence-associated secretory phenotype (SASP) and age-related autoimmune predisposition. However, the inability to reduce senescent somatic cells (SSCs), because of immunosenescence, exacerbates inflammaging. Age-related adaptive immune system deviations, particularly altered T cell function, are derived from age-related thymic atrophy or involution, a hallmark of thymic aging. Recently, there have been major developments in understanding how age-related thymic involution contributes to inflammaging and immunosenescence at the cellular and molecular levels, including genetic and epigenetic regulation, as well as developments of many potential rejuvenation strategies. Herein, we discuss the research progress uncovering how age-related thymic involution contributes to immunosenescence and inflammaging, as well as their intersection. We also describe how T cell adaptive immunity mediates inflammaging and plays a crucial role in the progression of age-related neurological and cardiovascular diseases, as well as cancer. We then briefly outline the underlying cellular and molecular mechanisms of age-related thymic involution, and finally summarize potential rejuvenation strategies to restore aged thymic function.

Mechanisms of Calorie Restriction: A Review of Genes Required for the Life-Extending and Tumor-Inhibiting Effects of Calorie Restriction

This review focuses on mechanisms of calorie restriction (CR), particularly the growth hormone (GH)/insulin-like growth factor-1 (IGF-1) axis as an evolutionary conserved signal that regulates aging and lifespan, underlying the effects of CR in mammals. Topics include (1) the relation of the GH-IGF-1 signal with chronic low-level inflammation as one of the possible causative factors of aging, that is, inflammaging, (2) the isoform specificity of the forkhead box protein O (FoxO) transcription factors in CR-mediated regulation of cancer and lifespan, (3) the role for FoxO1 in the tumor-inhibiting effect of CR, (4) pleiotropic roles for FoxO1 in the regulation of disorders, and (5) sirtuin (Sirt) as a molecule upstream of FoxO. From the evolutionary view, the necessity of neuropeptide Y (Npy) for the effects of CR and the pleiotropic roles for Npy in life stages are also emphasized. Genes for mediating the effects of CR and regulating aging are context-dependent, particularly depending on nutritional states.

Different epigenetic clocks reflect distinct pathophysiological features of multiple sclerosis

Aim: Accumulating evidence links epigenetic age to diseases and age-related conditions, but little is known about its association with multiple sclerosis (MS). Materials & methods: We estimated epigenetic age acceleration measures using DNA methylation from blood or sorted cells of MS patients and controls. Results: In blood, sex (p = 4.39E-05) and MS (p = 2.99E-03) explained the variation in age acceleration, and isolated blood cell types showed different epigenetic age. Intrinsic epigenetic age acceleration and extrinsic epigenetic age acceleration were only associated with sex (p = 2.52E-03 and p = 1.58E-04, respectively), while PhenoAge Acceleration displayed positive association with MS (p = 3.40E-02). Conclusion: Different age acceleration measures are distinctly influenced by phenotypic factors, and they might measure separate pathophysiological aspects of MS. Data deposition: DNA methylation data can be accessed at Gene Expression Omnibus database under accession number GSE35069, GSE43976, GSE106648, GSE130029, GSE130030.

Vitamin D in physiological and pathological aging: Lesson from centenarians

Vitamin D is a secosteroid hormone that exerts a pleiotropic action on a wide spectrum of tissues, apparatuses and systems. Thus, vitamin D has assumed an increasingly dominant role as a key determinant of biological mechanisms and specific clinical conditions. Older people frequently present vitamin D deficiency, a status potentially influencing several mechanisms responsible for different age-related diseases. Centenarians symbolize the ideal model for investigating the peculiar traits of longevity, as they have reached an age close to the estimated limit of the human lifespan. Interestingly, despite the profound heterogeneity of centenarians in terms of health status, all these people share the same condition of severe vitamin D deficiency, suggesting that they may have implemented a number of adaptive strategies to cope with the age-related physiological derangement of vitamin D metabolism. The lesson deriving from centenarians' experience suggests that: i) severe vitamin D deficiency does not preclude the possibility of reaching extreme longevity, ii) strategies to prevent hypovitaminosis D may be useful to slow down the processes of "fragilization" occurring in aged people, iii) beneficial effects of vitamin D supplementation need to be confirmed regarding longevity.

If my muscle could talk: Myokines as a biomarker of frailty

Frailty is a potentially reversible state of increased vulnerability to negative health-related outcomes that occurs as a result of multisystem biological impairment and environmental aspects. Given the relevance of this condition in both clinics and research, biomarkers of frailty have been actively sought after. Although several candidate biomarkers of frailty have been identified, none of them has yet been incorporated in the assessment or monitoring of the condition. Over the last years, increasing research interest has been focused on myokines, a set of cytokines, small proteins and proteoglycan peptides that are synthetized, expressed and released by skeletal myocytes in response to muscular contractions. Myokines may act in autocrine, paracrine, and endocrine manner and regulate several processes associated with physical frailty, including muscle wasting, dynapenia, and slowness. This review discusses the rationale to support the use of myokines as biomarkers of frailty in older adults.

Accelerating research on biological aging and mental health: Current challenges and future directions

Aging is associated with complex biological changes that can be accelerated, slowed, or even temporarily reversed by biological and non-biological factors. This article focuses on the link between biological aging, psychological stressors, and mental illness. Rather than comprehensively reviewing this rapidly expanding field, we highlight challenges in this area of research and propose potential strategies to accelerate progress in this field. This effort requires the interaction of scientists across disciplines - including biology, psychiatry, psychology, and epidemiology; and across levels of analysis that emphasize different outcome measures - functional capacity, physiological, cellular, and molecular. Dialogues across disciplines and levels of analysis naturally lead to new opportunities for discovery but also to stimulating challenges. Some important challenges consist of 1) establishing the best objective and predictive biological age indicators or combinations of indicators, 2) identifying the basis for inter-individual differences in the rate of biological aging, and 3) examining to what extent interventions can delay, halt or temporarily reverse aging trajectories. Discovering how psychological states influence biological aging, and vice versa, has the potential to create novel and exciting opportunities for healthcare and possibly yield insights into the fundamental mechanisms that drive human aging.

DEL-1-Regulated Immune Plasticity and Inflammatory Disorders

In contrast to traditional immune cell-centered viewpoints, recent studies suggest that tissues are not passive recipients of immunity but have a 'regulatory say' over the host inflammatory response. Identification of tissue-derived homeostatic molecules regulating immune plasticity is seminal for understanding the inherent regulatory potential of different organs in the immune response. DEL-1 (developmental endothelial locus-1) is a secreted multidomain protein interacting with integrins and phospholipids and regulates, depending on its expression location, distinct stages of the host inflammatory response (from myelopoiesis over leukocyte recruitment to efferocytosis and resolution of inflammation). Here we synthesize recent evidence of DEL-1 as an exemplar local regulatory factor in the context of tissue immune plasticity and inflammatory disorders (such as periodontitis, multiple sclerosis, and pulmonary disorders), and discuss its potential as a therapeutic agent.

Aging and Imaging Assessment of Body Composition: From Fat to Facts

The aging process is characterized by the chronic inflammatory status called "inflammaging", which shares major molecular and cellular features with the metabolism-induced inflammation called "metaflammation." Metaflammation is mainly driven by overnutrition and nutrient excess, but other contributing factors are metabolic modifications related to the specific body composition (BC) changes occurring with age. The aging process is indeed characterized by an increase in body total fat mass and a concomitant decrease in lean mass and bone density, that are independent from general and physiological fluctuations in weight and body mass index (BMI). Body adiposity is also re-distributed with age, resulting in a general increase in trunk fat (mainly abdominal fat) and a reduction in appendicular fat (mainly subcutaneous fat). Moreover, the accumulation of fat infiltration in organs such as liver and muscles also increases in elderly, while subcutaneous fat mass tends to decrease. These specific variations in BC are considered risk factors for the major age-related diseases, such as cardiovascular diseases, type 2 diabetes, sarcopenia and osteoporosis, and can predispose to disabilities. Thus, the maintenance of a balance rate of fat, muscle and bone is crucial to preserve metabolic homeostasis and a health status, positively contributing to a successful aging. For this reason, a detailed assessment of BC in elderly is critical and could be an additional preventive personalized strategy for age-related diseases. Despite BMI and other clinical measures, such as waist circumference measurement, waist-hip ratio, underwater weighing and bioelectrical impedance, are widely used as a surrogate measure for body adiposity, they barely reflect the distribution of body fat. Because of the great advantages offered by imaging tools in research and clinics, the attention of clinicians is now moving to powerful imaging techniques such as computed tomography, magnetic resonance imaging, dual-energy X-ray absorptiometry and ultrasound to obtain a more accurate estimation of BC. The aim of this review is to present the state of the art of the imaging techniques that are currently available to measure BC and that can be applied to the study of BC changes in the elderly, outlining advantages and disadvantages of each technique.