Evolution in health and medicine Sackler colloquium: Evolution of the human lifespan and diseases of aging: roles of infection, inflammation, and nutrition

Harnessing Genetics to Extend Lifespan and Healthspan: Current Progress and Future Directions

Aging is inevitable, but the lifespan (duration of life) and healthspan (healthy aging) vary greatly among individuals and across species. Unlocking the secrets behind these differences has captivated scientific curiosity for ages. This review presents relevant recent advances in genetics and cell biology that are shedding new light by untangling how subtle changes in conserved genes, pathways, and epigenetic factors influence organismal senescence and associated declines. Biogerontology is a complex and rapidly growing field aimed at elucidating genetic modifications that extend lifespan and healthspan. This review explores gerontogenes, genes influencing lifespan and healthspan across species. Though subtle differences exist, long-lived individuals such as centenarians demonstrate extended healthspans, and numerous studies confirm the heritability of longevity/healthspan genes. Importantly, genes and gerontogenes are directly and indirectly involved in DNA repair, insulin/IGF-1 and mTOR signaling pathways, long non-coding RNAs, sirtuins, and heat shock proteins. The complex interactions between genetics and epigenetics are teased apart. While more research into optimizing healthspan is needed, conserved gerontogenes offer synergistic potential to forestall aging and age-related diseases. Understanding complex longevity genetics brings closer the goal of extending not only lifespan but quality years of life. The primary aim of human Biogerontology is to enhance lifespan and healthspan, but the question remains: are current genetic modifications effectively promoting healthy aging? This article collates the advancements in gerontogenes that enhance lifespan and improve healthspan alongside their potential challenges.

Parkinson Disease Genetics Extended to African and Hispanic Ancestries in the VA Million Veteran Program

Background and Objectives

Nearly all genetic analyses of Parkinson disease (PD) have been in populations of European ancestry. We sought to test the ability of a machine learning method to extract accurate PD diagnoses from an electronic medical record (EMR) system, to see whether genetic variants identified in European populations generalize to individuals of African and Hispanic ancestries, and to compare the rates of PD across ancestries.

Methods

A machine learning method using natural language processing was applied to EMRs of US veterans participating in the VA Million Veteran Program (MVP) to identify individuals with PD. These putative cases were vetted via blind chart review by a movement disorder specialist. A polygenic risk score (PRS) of 90 established genetic variants whose genotypes were imputed from a customized Axiom Biobank Array was evaluated in different case groups.

Results

The EMR prediction scores had a distinct trimodal distribution, with 97% of the high group and only 30% of the middle group having a credible diagnosis of PD. Using the 3,542 cases from the high group matched 4:1 to controls, the PRS was highly predictive in individuals of European ancestry (n = 3,137 cases; OR = 1.82; p = 8.01E-48), and nearly identical effect sizes were seen in individuals of African (n = 184; OR = 2.07; p = 3.4E-4) and Hispanic ancestries (n = 221; OR = 2.13; p = 3.9E-6). The PRS was much less predictive for the 2,757 European ancestry cases who had an ICD code for PD but for whom the machine learning method had a lower confidence in their diagnosis. No novel ancestry-specific genetic variants were identified. Individuals with African ancestry had one-quarter the rate of PD compared with European or Hispanic ancestries aged 60-70 years and one half the rate in the 70-80 years age range. African American cases had a higher proportion of their DNA originating in Europe compared with African American controls.

Discussion

Machine learning can reliably classify PD using data from a large EMR. Larger studies of non-European populations are required to confirm the generalizability of PD risk variants identified in populations of European ancestry and the increased risk coming from a higher proportion of European DNA in African Americans.

The economics of aging with infectious and chronic diseases

We develop an economic model of aging in which the susceptibility and severity of infectious diseases depend on the accumulated health deficits (immunosenescence) and the life history of infections affects the accumulation of chronic health deficits (inflammaging). Individuals invest in their health to slow down health deficit accumulation and take measures to protect themselves from infectious diseases. We calibrate the model for an average American and explore how health expenditure, life expectancy, and the value of life depend on individual characteristics, medical technology, and the disease environment. We then use counterfactual computational experiments of the U.S. epidemiological transition 1860-2010 to show that the decline of infectious diseases caused a substantial decline of chronic diseases and contributed more to increasing life expectancy than advances in the treatment of chronic diseases.

Comparative epidemiological study of breast cancer in humans and canine mammary tumors: insights from Portugal

Dogs spontaneously develop mammary gland tumors (MGT) and exhibit striking similarities in clinical and epidemiological characteristics to human breast cancer (HBC). Descriptive and comparative analysis of HBC and canine MGT with a focus on evaluating similarities and geographical distribution were the aims of this study. HBC cases were obtained from North Regional Oncological Registry (RORENO) (2010-2015) and canine MGT cases from Vet-OncoNet (2019-2022). Analyses were performed based on published and well accepted classification systems (ICD-O-3.2 for humans and Vet-ICD-O-canine-1). Age-standardized incidence risks (ASIR) of Porto district municipalities were calculated using 2021 Portuguese census (INE) and data from the Portuguese animal registration system (SIAC). Among 7,674 HBC cases and 1,140 MGT cases, a similar age and sex distribution pattern was observed. Approximately 69.2% of HBC cases were between 40 and 69 years old, while 66.9% of MGT cases were diagnosed between 7 and 12 years old (mean age of 9.6 years, SD = 2.6). In women, Invasive breast carcinoma (8500/3) was the most common histological type (n = 5,679, 74%) while in dogs it was the Complex Carcinoma (8983.1/3) (n = 205, 39%). Cocker and Yorkshire Terriers exhibited the highest relative risks (3.2 and 1.6, p < 0.05, respectively) when compared to cross breed dogs. The municipalities' ASIR of the two species exhibited a high correlation (R = 0.85, p < 0.01) and the spatial cluster analysis revealed similar geographic hotspots. Also, higher ASIR values both in women and dogs were more frequently found in urbanized areas compared to rural areas. This research sheds light on the shared features and geographical correlation between HBC and canine MGT, highlighting the potential of cross-species environmental oncology studies.

Anti-microbial resistance and aging-A design for evolution

The emergence of resistance to anti-infective agents poses a significant threat to successfully treating infections caused by bacteria. Bacteria acquire random mutations due to exposure to environmental stresses, which may increase their fitness to other selection pressures. Interestingly, for bacteria, the frequency of anti-microbial resistance (AMR) seems to be increasing in tandem with the human lifespan. Based on evidence from previous literature, we speculate that increased levels of free radicals (Reactive Oxygen Species-ROS and Reactive Nitrosative Species-RNS), elevated inflammation, and the altered tissue microenvironment in aged individuals may drive pathogen mutagenesis. If these mutations result in the hyperactivation of efflux pumps or alteration in drug target binding sites, it could confer AMR, thus rendering antibiotic therapy ineffective while leading to the selection of novel drug-resistant variants. This article is categorized under: Immune System Diseases > Genetics/Genomics/Epigenetics Infectious Diseases > Environmental Factors Metabolic Diseases > Environmental Factors.

Assessing cognitive decline in the aging brain: lessons from rodent and human studies

As life expectancy continues to increase worldwide, age-related dysfunction will largely impact our societies in the future. Aging is well established to promote the deterioration of cognitive function and is the primary risk factor for the development of prevalent neurological disorders. Even in the absence of dementia, age-related cognitive decline impacts specific types of memories and brain structures in humans and animal models. Despite this, preclinical and clinical studies that investigate age-related changes in brain physiology often use largely different methods, which hinders the translational potential of findings. This review seeks to integrate what is known about age-related changes in the brain with analogue cognitive tests used in humans and rodent studies, ranging from "pen and paper" tests to virtual-reality-based paradigms. Finally, we draw parallels between the behavior paradigms used in research compared to the enrollment into clinical trials that aim to study age-related cognitive decline.

New insight into the causes, consequences, and correction of hematopoietic stem cell aging

Aging of hematopoietic stem cells (HSCs) is characterized by lineage bias, increased clonal expansion, and functional decrease. At the molecular level, aged HSCs typically display metabolic dysregulation, upregulation of inflammatory pathways, and downregulation of DNA repair pathways. Cellular aging of HSCs, driven by cell-intrinsic and cell-extrinsic factors, causes a predisposition to anemia, adaptive immune compromise, myelodys, plasia, and malignancy. Most hematologic diseases are strongly associated with age. But what is the biological foundation for decreased fitness with age? And are there therapeutic windows to resolve age-related hematopoietic decline? These questions were the focus of the International Society for Experimental Hematology (ISEH) New Investigator Committee Fall 2022 Webinar. This review touches on the latest insights from two leading laboratories into inflammatory- and niche-driven stem cell aging and includes speculation on strategies to prevent or correct age-related decline in HSC function.

Assessment of nutritional status using anthropometric index among older adult and elderly population in India

Malnutrition poses a significant risk to the older population globally, highlighting the critical role of nutrition in healthy aging. In this study, the aim is to estimate the prevalence of malnutrition among older adults aged 45-59 years and the elderly population aged 60 years and above based on their socioeconomic and demographic characteristics. Furthermore, the study examines the risk factors within a multivariate framework. A sample of 59,073 individuals aged 45 years and above from the Longitudinal Aging Study in India (LASI), Wave 1 survey constitutes the study population. This study adopts a cross-sectional design. Bivariate cross-tabulation analysis and multivariate logistic regression analysis are employed to understand the prevalence and determinants of nutritional status. About 25% of males and 37% of females below the age of 60 years are overweight (including obese), while among those aged 60 years and above, 28% of males and 25% of females are underweight. The elderly male population carries a comparatively higher burden of underweight (28%) prevalence than the females (25%) in the same age group. Overall, the urban population is less likely to be underweight [AOR: 0.41, C.I 0.38-0.43] and more likely to be overweight [AOR: 2.41, C.I 2.32-2.52]. Older adults from low economic and social strata are more likely to be underweight. In terms of bio-physical factors, individuals aged 60 years and above with infections to endemic diseases [AOR: 1.24; p-value < 0.01] and those with edentulism [AOR: 1.29; p-value < 0.01] are more likely to be underweight. As evident from the study, nutritional status among older adults is a complicated manifestation of multiple risk factors and requires potential nutritional intervention. Initiating a routine screening program at the grassroots level can effectively identify older adults and the elderly in India, facilitating the provision of nutritional care.

Physiological aging in India: The role of the epidemiological transition

We construct a cohort-based frailty index from age-related health deficits to investigate physiological aging in India over the period 1990-2019. During this period, the Indian states underwent at different speeds the epidemiological transition and experienced unprecedented economic growth. We show that the rate of physiological aging remained remarkably stable to the changing environment. Age-related health deficits increased by about 3 percent per year of age with little variation across states, ages, cohorts, and over time. We find that, with advancing epidemiological transition, health deficits for given age declined at the individual level (within states and within cohorts). Across cohorts born between 1900 and 1995, we show that, for given age, health deficits are higher for later-born cohorts until birth years around 1940 and remained trendless afterwards. We propose a selection-based theory of aging during the epidemiological transition that explains these facts.

Genomic Instability Evolutionary Footprints on Human Health: Driving Forces or Side Effects?

In this work, we propose a comprehensive perspective on genomic instability comprising not only the accumulation of mutations but also telomeric shortening, epigenetic alterations and other mechanisms that could contribute to genomic information conservation or corruption. First, we present mechanisms playing a role in genomic instability across the kingdoms of life. Then, we explore the impact of genomic instability on the human being across its evolutionary history and on present-day human health, with a particular focus on aging and complex disorders. Finally, we discuss the role of non-coding RNAs, highlighting future approaches for a better living and an expanded healthy lifespan.

Aging - what it is and how to measure it

The current understanding of the biology of aging is largely based on research aimed at identifying factors that influence lifespan. However, lifespan as a sole proxy measure of aging has limitations because it can be influenced by specific pathologies (not generalized physiological deterioration in old age). Hence, there is a great need to discuss and design experimental approaches that are well-suited for studies targeting the biology of aging, rather than the biology of specific pathologies that restrict the lifespan of a given species. For this purpose, we here review various perspectives on aging, discuss agreement and disagreement among researchers on the definition of aging, and show that while slightly different aspects are emphasized, a widely accepted feature, shared across many definitions, is that aging is accompanied by phenotypic changes that occur in a population over the course of an average lifespan. We then discuss experimental approaches that are in line with these considerations, including multidimensional analytical frameworks as well as designs that facilitate the proper assessment of intervention effects on aging rate. The proposed framework can guide discovery approaches to aging mechanisms in all key model organisms (e.g., mouse, fish models, D. melanogaster, C. elegans) as well as in humans.

Age differences in cortical thickness and their association with cognition in chimpanzee (Pan troglodytes)

Humans and chimpanzees are genetically similar and share a number of life history, behavioral, cognitive and neuroanatomical similarities. Notwithstanding, our understanding of age-related changes in cognitive and motor functions in chimpanzees remains largely unstudied despite recent evident demonstrating that chimpanzees exhibit many of the same neuropathological features of Alzheimer's disease observed in human postmortem brains. Here, we examined age-related differences in cognition and cortical thickness measured from magnetic resonance images in a sample of 215 chimpanzees ranging in age between 9 and 54 years. We found that chimpanzees showed global and region-specific thinning of cortex with increasing age. Further, within the elderly cohort, chimpanzees that performed better than average had thicker cortex in frontal, temporal and parietal regions compared to chimpanzees that performed worse than average. Independent of age, we also found sex differences in cortical thickness in 4 brain regions. Males had higher adjusted cortical thickness scores for the caudal anterior cingulate, rostral anterior cingulate, and medial orbital frontal while females had higher values for the inferior parietal cortex. We found no evidence that increasing age nor sex was associated with asymmetries in cortical thickness. Moreover, age-related differences in cognitive function were only weakly associated with asymmetries in cortical thickness. In summary, as has been reported in humans and other primates, elderly chimpanzees show thinner cortex and variation in cortical thickness is associated with general cognitive functions.

Programmed ageing: decline of stem cell renewal, immunosenescence, and Alzheimer's disease

The characteristic maximum lifespan varies enormously across animal species from a few hours to hundreds of years. This argues that maximum lifespan, and the ageing process that itself dictates lifespan, are to a large extent genetically determined. Although controversial, this is supported by firm evidence that semelparous species display evolutionarily programmed ageing in response to reproductive and environmental cues. Parabiosis experiments reveal that ageing is orchestrated systemically through the circulation, accompanied by programmed changes in hormone levels across a lifetime. This implies that, like the circadian and circannual clocks, there is a master 'clock of age' (circavital clock) located in the limbic brain of mammals that modulates systemic changes in growth factor and hormone secretion over the lifespan, as well as systemic alterations in gene expression as revealed by genomic methylation analysis. Studies on accelerated ageing in mice, as well as human longevity genes, converge on evolutionarily conserved fibroblast growth factors (FGFs) and their receptors, including KLOTHO, as well as insulin-like growth factors (IGFs) and steroid hormones, as key players mediating the systemic effects of ageing. Age-related changes in these and multiple other factors are inferred to cause a progressive decline in tissue maintenance through failure of stem cell replenishment. This most severely affects the immune system, which requires constant renewal from bone marrow stem cells. Age-related immune decline increases risk of infection whereas lifespan can be extended in germfree animals. This and other evidence suggests that infection is the major cause of death in higher organisms. Immune decline is also associated with age-related diseases. Taking the example of Alzheimer's disease (AD), we assess the evidence that AD is caused by immunosenescence and infection. The signature protein of AD brain, Aβ, is now known to be an antimicrobial peptide, and Aβ deposits in AD brain may be a response to infection rather than a cause of disease. Because some cognitively normal elderly individuals show extensive neuropathology, we argue that the location of the pathology is crucial - specifically, lesions to limbic brain are likely to accentuate immunosenescence, and could thus underlie a vicious cycle of accelerated immune decline and microbial proliferation that culminates in AD. This general model may extend to other age-related diseases, and we propose a general paradigm of organismal senescence in which declining stem cell proliferation leads to programmed immunosenescence and mortality.

Long-Term Transcriptomic Changes and Cardiomyocyte Hyperpolyploidy after Lactose Intolerance in Neonatal Rats

Many cardiovascular diseases originate from growth retardation, inflammation, and malnutrition during early postnatal development. The nature of this phenomenon is not completely understood. Here we aimed to verify the hypothesis that systemic inflammation triggered by neonatal lactose intolerance (NLI) may exert long-term pathologic effects on cardiac developmental programs and cardiomyocyte transcriptome regulation. Using the rat model of NLI triggered by lactase overloading with lactose and the methods of cytophotometry, image analysis, and mRNA-seq, we evaluated cardiomyocyte ploidy, signs of DNA damage, and NLI-associated long-term transcriptomic changes of genes and gene modules that differed qualitatively (i.e., were switched on or switched off) in the experiment vs. the control. Our data indicated that NLI triggers the long-term animal growth retardation, cardiomyocyte hyperpolyploidy, and extensive transcriptomic rearrangements. Many of these rearrangements are known as manifestations of heart pathologies, including DNA and telomere instability, inflammation, fibrosis, and reactivation of fetal gene program. Moreover, bioinformatic analysis identified possible causes of these pathologic traits, including the impaired signaling via thyroid hormone, calcium, and glutathione. We also found transcriptomic manifestations of increased cardiomyocyte polyploidy, such as the induction of gene modules related to open chromatin, e.g., "negative regulation of chromosome organization", "transcription" and "ribosome biogenesis". These findings suggest that ploidy-related epigenetic alterations acquired in the neonatal period permanently rewire gene regulatory networks and alter cardiomyocyte transcriptome. Here we provided first evidence indicating that NLI can be an important trigger of developmental programming of adult cardiovascular disease. The obtained results can help to develop preventive strategies for reducing the NLI-associated adverse effects of inflammation on the developing cardiovascular system.

A micronutrient mixture with collagen peptides, probiotics, cannabidiol, and diet may reduce aging, and development and progression of age-related alzheimer's disease, and improve its treatment

Human aging involves gradual decline in organ functions leading to organ specific age-related chronic diseases such as Alzheimer's disease (AD). Although advances in the development of new drugs, novel surgical procedures, improved diet and lifestyle, have resulted in doubling of lifespan of humans, the quality of life in many cases remains poor because of increased incidence of age-related chronic diseases. Using experimental models of accelerated aging, several cellular defects associated with aging and AD have been identified. Some cellular defects due to increased oxidative stress, chronic inflammation, autophagy defects, mitochondrial dysfunction, and imbalances in the composition probiotics in favor of harmful bacteria over beneficial bacteria are common to both aging and AD, while others such as telomere attrition, loss of collagen, elastin, and hyaluronic acid, failure of DNA repair system, and impaired immune function are unique to aging; and some such as increased production of beta-amyloids, hyperphosphorylation of tau protein, and abnormal behaviors are unique to AD. It is suggested that supplementation with a micronutrient mixture, probiotics, collagen peptides, CBD, and modifications in the diet and lifestyle may reduce the aging processes, and the development, progression of AD, and improve the treatments of this disease.

Evolutionary and genomic perspectives of brain aging and neurodegenerative diseases

This chapter utilizes genomic concepts and evolutionary perspectives to further understand the possible links between typical brain aging and neurodegenerative diseases, focusing on the two most prevalent of these: Alzheimer's disease and Parkinson's disease. Aging is the major risk factor for these neurodegenerative diseases. Researching the evolutionary and molecular underpinnings of aging helps to reveal elements of the typical aging process that leave individuals more vulnerable to neurodegenerative pathologies. Very little is known about the prevalence and susceptibility of neurodegenerative diseases in nonhuman species, as only a few individuals have been observed with these neuropathologies. However, several studies have investigated the evolution of lifespan, which is closely connected with brain size in mammals, and insights can be drawn from these to enrich our understanding of neurodegeneration. This chapter explores the relationship between the typical aging process and the events in neurodegeneration. First, we examined how age-related processes can increase susceptibility to neurodegenerative diseases. Second, we assessed to what extent neurodegeneration is an accelerated form of aging. We found that while at the phenotypic level both neurodegenerative diseases and the typical aging process share some characteristics, at the molecular level they show some distinctions in their profiles, such as variation in genes and gene expression. Furthermore, neurodegeneration of the brain is associated with an earlier onset of cellular, molecular, and structural age-related changes. In conclusion, a more integrative view of the aging process, both from a molecular and an evolutionary perspective, may increase our understanding of neurodegenerative diseases.

Are We What We Eat? The Moral Imperative of the Medical Profession to Promote Plant-Based Nutrition

The typical Western diet, high in processed and animal-based foods, is nutritionally and ethically problematic. Beyond the well-documented cruelty to animals that characterizes the practices of the factory-farming industry, current patterns of meat consumption contribute to medical and moral harm in humans on both an individual level and a public health scale. We aim to deconstruct, by highlighting their fallacies, the common positive and normative arguments that are used to defend current nutritional patterns. Animal-based foods promote the mechanisms that underlie chronic cardiometabolic disease, whereas whole-food plant-based nutrition can reverse them. Factory farming of animals also contributes to climate change, antibiotic resistance, and the spread of infectious diseases. Finally, the current allocation of nutritional resources in the United States is unjust. A societal shift toward more whole-food plant-based patterns of eating stands to provide significant health benefits and ethical advantages, and the medical profession has a duty to advocate accordingly. Although it remains important for individuals to make better food choices to promote their own health, personal responsibility is predicated on sound advice and on resource equity, including the availability of healthy options. Nutrition equity is a moral imperative and should be a top priority in the promotion of public health.

Epigenetic age acceleration correlates with BMI in young adults

INTRODUCTION

Obesity increases the risk of Type 2 diabetes, cardiovascular disease, several types of cancer, and other age-related disorders. Among older adults, obesity is also related to epigenetic age, typically measured with DNA methylation (DNAm). Because less is known about obesity and epigenetic aging earlier in the lifespan, this study examined the relationship between obesity and DNAm in young adulthood and whether these relationships vary by sex.

METHODS

A cross-sectional community sample of 290 healthy young adults (mean age 27.39 years, 60% female; 80% African American, 18% White) had their BMI and waist circumference measured. Four epigenetic age estimators were derived from salivary DNA: Hannum DNAm, Horvath DNAm, Phenoage DNAm, and GrimAge DNAm. Sociodemographic covariates included age, sex, race, parental education, and income-to-needs ratio.

RESULTS

After adjusting for covariates, higher BMI and waist were associated with higher DNAm PhenoAge in both sexes, with a stronger effect on BMI in males (β = 0.35, p < .001) compared to females (β = 0.13, p = .002). Higher waist, but not BMI, was associated with higher Horvath DNA methylation age. Both BMI and waist circumference were associated with higher Hannum DNAm age in men but not in women. Neither BMI nor waist circumference were related to GrimAge.

DISCUSSION

This study extends prior research by linking obesity with accelerated epigenetic aging in young adulthood, replicating the associations across two measures of obesity and four indices of salivary epigenetic aging. The results add to evidence that higher BMI accelerates aging early in the lifespan.

Evolution led humans to bipedalism, but we live in a sedentary society: Will "Sunday running" protect us from NCDs at no cost?

Evolution led humans to bipedal stance and movement. However, we live in a sedentary society that strongly challenges our willingness to be physically active. We (mis)understand that being at least a Sunday runner could protect us from sedentary-related diseases, but what if this compromises the healthier life expectancy anyway? Citing Paul Gauguin, we know where we come from and what we are, the question arises about where we are going. And also, how.

Mitochondrial decline in the ageing old world primate retina: Little evidence for difference between the centre and periphery

Mitochondrial decline is a key feature of ageing. The retina has more mitochondria than any other tissue and ages rapidly. To understand human retinal ageing it is critical to examine old world primates that have similar visual systems to humans, and do so across central and peripheral regions, as there is evidence for early central decline. Hence, we examine mitochondrial metrics in young and ageing Macaca fascicularis retinae. In spite of reduced ATP with age, primate mitochondrial complex activity did not decline. But mitochondrial membrane potentials were reduced significantly, and concomitantly, mitochondrial membrane permeability increased. The mitochondrial marker Tom20 declined significantly, consistent with reduced mitochondria number, while VDAC, a voltage dependent anion channel and diffusion pore associated with apoptosis increased significantly. In spite of these clear age-related changes, there was almost no evidence for regional differences between the centre and the periphery in these mitochondrial metrics. Primate cones do not die with age, but many showed marked structural decline with vacuous spaces in proximal inner segments normally occupied by endoplasmic reticulum (ER), that regulate mitochondrial autophagy. In many peripheral cones, ER was displaced by the nucleus that transposed across the outer limiting membrane and could become embedded in mitochondrial populations. These data are consistent with significant changes in retinal mitochondria in old world primate ageing but provide little if any evidence that aged central mitochondria suffer more than those in the periphery.

Ageing at Molecular Level: Role of MicroRNAs

The progression of age triggers a vast number of diseases including cardiovascular, cancer, and neurodegenerative disorders. Regardless of our plentiful knowledge about age-related diseases, little is understood about molecular pathways that associate the ageing process with various diseases. Several cellular events like senescence, telomere dysfunction, alterations in protein processing, and regulation of gene expression are common between ageing and associated diseases. Accumulating information on the role of microRNAs (miRNAs) suggests targeting miRNAs can aid our understanding of the interplay between ageing and associated diseases. In the present chapter, we have attempted to explore the information available on the role of miRNAs in ageing of various tissues/organs and diseases and understand the molecular mechanism of ageing.

Where is the When of Creativity?: Specifying the Temporal Dimension of the Four Cs of Creativity

Creativity researchers typically focus on the who, what, why, where, and how of creativity. A noticeable omission is when. The when is not completely ignored in the field; it surfaces in developmental and evolutionary perspectives, the study of eminent creators, and other avenues of scholarship. In this paper, we assert that for the concept of when to be fully addressed researchers need to more actively consider the past, present, and future and how they interact. More specifically, we propose an expanded way of thinking about the when of creativity by introducing a temporal dimension to the definition of creativity. Our definition offers a broader lens for researchers to consider the temporal dimensions of originality, meaningfulness, and impact of creativity. After introducing our definition and describing its unique features, we discuss how researchers can use our definition to trace creative phenomena across a full temporal trajectory and thereby provide more nuanced and dynamic representation of how the features of creativity change across time and contexts. Finally, we apply this temporal definition to the Four Cs Model of Creativity to illustrate how considering the when can help resolve lingering questions about this perspective.

Why Gilgamesh failed: the mechanistic basis of the limits to human lifespan

The purpose of this Perspective is to clarify for an interdisciplinary audience the fundamental concepts of human longevity and provide evidence for a limit to human lifespan. This observed limit is placed into a broader framework by showing how it has arisen through the process of evolution and by enumerating the molecular mechanisms that may enforce it. Finally, we look toward potential future developments and the prospects for possibly circumventing the current limit.

Integrating biobehavioral information to predict mood disorder suicide risk

The will to live and the ability to maintain one's well-being are crucial for survival. Yet, almost a million people die by suicide globally each year (Aleman and Denys, 2014), making premature deaths due to suicide a significant public health problem (Saxena et al., 2013). The expression of suicidal behaviors is a complex phenotype with documented biological, psychological, clinical, and sociocultural risk factors (Turecki et al., 2019). From a brain disease perspective, suicide is associated with neuroanatomical, neurophysiological, and neurochemical dysregulations of brain networks involved in integrating and contextualizing cognitive and emotional regulatory behaviors. From a symptom perspective, diagnostic measures of dysregulated mood states like major depressive symptoms are associated with over sixty percent of suicide deaths worldwide (Saxena et al., 2013). This paper reviews the neurobiological and clinical phenotypic correlates for mood dysregulations and suicidal phenotypes. We further propose machine learning approaches to integrate neurobiological measures with dysregulated mood symptoms to elucidate the role of inflammatory processes as neurobiological risk factors for suicide.

Breaking the aging epigenetic barrier

Aging is an inexorable event occurring universally for all organisms characterized by the progressive loss of cell function. However, less is known about the key events occurring inside the nucleus in the process of aging. The advent of chromosome capture techniques and extensive modern sequencing technologies have illuminated a rather dynamic structure of chromatin inside the nucleus. As cells advance along their life cycle, chromatin condensation states alter which leads to a different epigenetic landscape, correlated with modified gene expression. The exact factors mediating these changes in the chromatin structure and function remain elusive in the context of aging cells. The accumulation of DNA damage, reactive oxygen species and loss of genomic integrity as cells cease to divide can contribute to a tumor stimulating environment. In this review, we focus on genomic and epigenomic changes occurring in an aged cell which can contribute to age-related tumor formation.

A Combined Chronic Low-Dose Soluble Epoxide Hydrolase and Acetylcholinesterase Pharmacological Inhibition Promotes Memory Reinstatement in Alzheimer’s Disease Mice Models

Alzheimer’s disease (AD) is a progressive neurological disorder with multifactorial and heterogeneous causes. AD involves several etiopathogenic mechanisms such as aberrant protein accumulation, neurotransmitter deficits, synaptic dysfunction and neuroinflammation, which lead to cognitive decline. Unfortunately, the currently available anti-AD drugs only alleviate the symptoms temporarily and provide a limited therapeutic effect. Thus, new therapeutic strategies, including multitarget approaches, are urgently needed. It has been demonstrated that a co-treatment of acetylcholinesterase (AChE) inhibitor with other neuroprotective agents has beneficial effects on cognition. Here, we have assessed the neuroprotective effects of chronic dual treatment with a soluble epoxide hydrolase (sEH) inhibitor (TPPU) and an AChE inhibitor (6-chlorotacrine or rivastigmine) in in vivo studies. Interestingly, we have found beneficial effects after chronic low-dose co-treatment with TPPU and 6-chlorotacrine in the senescence-accelerated mouse prone 8 (SAMP8) mouse model as well as with TPPU and rivastigmine co-treatment in the 5XFAD mouse model, in comparison with the corresponding monotherapy treatments. In the SAMP8 model, no substantial improvements in synaptic plasticity markers were found, but the co-treatment of TPPU and 6-chlorotacrine led to a significantly reduced gene expression of neuroinflammatory markers, such as interleukin 6 (Il-6), triggering receptor expressed on myeloid cell 2 (Trem2) and glial fibrillary acidic protein (Gfap). In 5XFAD mice, chronic low-dose co-treatment of TPPU and rivastigmine led to enhanced protein levels of synaptic plasticity markers, such as the phospho-cAMP response element-binding protein (p-CREB) ratio, brain-derived neurotrophic factor (BDNF) and postsynaptic density protein 95 (PSD95), and also to a reduction in neuroinflammatory gene expression. Collectively, these results support the neuroprotectant role of chronic low-dose co-treatment strategy with sEH and AChE inhibitors in AD mouse models, opening new avenues for effective AD treatment.

Heat inactivated mycobacteria, alpha-gal and zebra fish: insights gained from experiences with two promising trained immunity inductors and a validated animal model

Trained immunity (TRAIM) may be defined as a form of memory where innate immune cells such as monocytes, macrophages, dendritic and natural killer (NK) cells undergo an epigenetic reprogramming that enhances their primary defensive capabilities. Cross-pathogen protective TRAIM can be triggered in different hosts by exposure to live microbes or microbe-derived products such as heat-inactivated Mycobacterium bovis or with the glycan α-Gal to elicit protective responses against several pathogens. We review the TRAIM paradigm using two models representing distinct scales of immune sensitization: the whole bacterial cell and one of its building blocks, the polysaccharides or glycans. Observations point out to macrophage lytic capabilities and cytokine regulation as two key components in nonspecific innate immune responses against infections. The study of the TRAIM response deserves attention to better characterize the evolution of host-pathogen cooperation both for identifying the etiology of some diseases and for finding new therapeutic strategies. In this field, the zebrafish provides a convenient and complete biological system that could help to deepen in the knowledge of TRAIM-mediated mechanisms in pathogen-host interactions. This article is protected by copyright. All rights reserved.

ALS/FTD: Evolution, Aging, and Cellular Metabolic Exhaustion

Amyotrophic lateral sclerosis and frontotemporal dementia (ALS/FTD) are neurodegenerations with evolutionary underpinnings, expansive clinical presentations, and multiple genetic risk factors involving a complex network of pathways. This perspective considers the complex cellular pathology of aging motoneuronal and frontal/prefrontal cortical networks in the context of evolutionary, clinical, and biochemical features of the disease. We emphasize the importance of evolution in the development of the higher cortical function, within the influence of increasing lifespan. Particularly, the role of aging on the metabolic competence of delicately optimized neurons, age-related increased proteostatic costs, and specific genetic risk factors that gradually reduce the energy available for neuronal function leading to neuronal failure and disease.

Spatial heterogeneity of human lifespan in relation to living environment and socio-economic polarization: a case study in the Beijing-Tianjin-Hebei region, China

The spatial heterogeneity and influence factors of public lifespan have been reported worldwide at the national level or typical longevous areas. However, few sub-national studies considering the living environment and socio-economic level together have been explored in the imbalanced developed region with a huge population base and deteriorated air quality. In this paper, spatial heterogeneity of lifespan integrating environment and socio-economic influence factors was investigated in the Beijing-Tianjin-Hebei (BTH) region of China using geographically weighted regression (GWR). Five indicators were constructed to determine the lifespan based on the three national censuses (1990-2010) in the BTH region. The results showed that the areas with higher CH (centenarians per 100,000 inhabitants) and centenarity index (CI) exhibited changing distribution in the BTH region, whereas those with lower CH and CI and extreme value of the ultra-octogenarian index (UOI) and LI (> 90/ > 65) maintained a relatively stable feature through time. But as lifespan indicators increase overall, the differences between the counties/districts widen. Furthermore, remarkable spatial heterogeneity was detected for the associations between the significant environmental and socio-economic variables and lifespan indicators. Although the natural geographic condition (altitude) still exhibited a negative influence on the longevity of the population, the socio-economic factors (GDP_pc and income level) showed a more dominant influence on the extension of the elderly and longevity population. Correspondingly, the widened unbalance of population lifespan (UOI, LI, CH) was considered closely related to the socio-economic polarization, and the adverse effects of air pollution on life expectancy at birth (LEB) have also emerged. To further improve the overall lifespan level and narrow the lifespan gap in the BTH region, future work on cleaner air and more balanced development is still needed.

Molecular Evolutionary Rate Predicts Intraspecific Genetic Polymorphism and Species-Specific Selection

It is unknown what determines genetic diversity and how genetic diversity is associated with various biological traits. In this work, we provide insight into these issues. By comparing genetic variation of 14,671 mammalian gene trees with thousands of individual human, chimpanzee, gorilla, mouse, and dog/wolf genomes, we found that intraspecific genetic diversity can be predicted by long-term molecular evolutionary rates rather than de novo mutation rates. This relationship was established during the early stage of mammalian evolution. Moreover, we developed a method to detect fluctuations of species-specific selection on genes based on the deviations of intraspecific genetic diversity predicted from long-term rates. We showed that the evolution of epithelial cells, rather than connective tissue, mainly contributed to morphological evolution of different species. For humans, evolution of the immune system and selective sweeps caused by infectious diseases are the most representative examples of adaptive evolution.

Evolutionary pressures rendered by animal husbandry practices for avian influenza viruses to adapt to humans

Commercial poultry operations produce and crowd billions of birds every year, which is a source of inexpensive animal protein. Commercial poultry is intensely bred for desirable production traits, and currently presents very low variability at the major histocompatibility complex. This situation dampens the advantages conferred by the MHC’s high genetic variability, and crowding generates immunosuppressive stress. We address the proteins of influenza A viruses directly and indirectly involved in host specificities. We discuss how mutants with increased virulence and/or altered host specificity may arise if few class I alleles are the sole selective pressure on avian viruses circulating in immunocompromised poultry. This hypothesis is testable with peptidomics of MHC ligands. Breeding strategies for commercial poultry can easily and inexpensively include high variability of MHC as a trait of interest, to help save billions of dollars as a disease burden caused by influenza and decrease the risk of selecting highly virulent strains.

Polyploidy as a Fundamental Phenomenon in Evolution, Development, Adaptation and Diseases

DNA replication during cell proliferation is 'vertical' copying, which reproduces an initial amount of genetic information. Polyploidy, which results from whole-genome duplication, is a fundamental complement to vertical copying. Both organismal and cell polyploidy can emerge via premature cell cycle exit or via cell-cell fusion, the latter giving rise to polyploid hybrid organisms and epigenetic hybrids of somatic cells. Polyploidy-related increase in biological plasticity, adaptation, and stress resistance manifests in evolution, development, regeneration, aging, oncogenesis, and cardiovascular diseases. Despite the prevalence in nature and importance for medicine, agri- and aquaculture, biological processes and epigenetic mechanisms underlying these fundamental features largely remain unknown. The evolutionarily conserved features of polyploidy include activation of transcription, response to stress, DNA damage and hypoxia, and induction of programs of morphogenesis, unicellularity, and longevity, suggesting that these common features confer adaptive plasticity, viability, and stress resistance to polyploid cells and organisms. By increasing cell viability, polyploidization can provide survival under stressful conditions where diploid cells cannot survive. However, in somatic cells it occurs at the expense of specific function, thus promoting developmental programming of adult cardiovascular diseases and increasing the risk of cancer. Notably, genes arising via evolutionary polyploidization are heavily involved in cancer and other diseases. Ploidy-related changes of gene expression presumably originate from chromatin modifications and the derepression of bivalent genes. The provided evidence elucidates the role of polyploidy in evolution, development, aging, and carcinogenesis, and may contribute to the development of new strategies for promoting regeneration and preventing cardiovascular diseases and cancer.

Increased risk of cancer in dogs and humans: a consequence of recent extension of lifespan beyond evolutionarily-determined limitations?

Cancer is among the most common causes of death for dogs (and cats) and humans in the developed world, even though it is uncommon in wildlife and other domestic animals. We provide a rationale for this observation based on recent advances in our understanding of the evolutionary basis of cancer. Over the course of evolutionary time, species have acquired and fine-tuned adaptive cancer protective mechanisms that are intrinsically related to their energy demands, reproductive strategies, and expected lifespan. These cancer protective mechanisms are general across species and/or specific to each species and their niche, and they do not seem to be limited in diversity. The evolutionarily acquired cancer-free longevity that defines a species' life history can explain why the relative cancer risk, rate, and incidence are largely similar across most species in the animal kingdom despite differences in body size and life expectancy. The molecular, cellular, and metabolic events that promote malignant transformation and cancerous growth can overcome these adaptive, species-specific protective mechanisms in a small proportion of individuals, while independently, some individuals in the population might achieve exceptional longevity. In dogs and humans, recent dramatic alterations in healthcare and social structures have allowed increasing numbers of individuals in both species to far exceed their species-adapted longevities (by 2-4 times) without allowing the time necessary for compensatory natural selection. In other words, the cancer protective mechanisms that restrain risk at comparable levels to other species for their adapted lifespan are incapable of providing cancer protection over this recent, drastic and widespread increase in longevity.

Genes and Longevity of Lifespan

Aging is a complex process indicated by low energy levels, declined physiological activity, stress induced loss of homeostasis leading to the risk of diseases and mortality. Recent developments in medical sciences and an increased availability of nutritional requirements has significantly increased the average human lifespan worldwide. Several environmental and physiological factors contribute to the aging process. However, about 40% human life expectancy is inherited among generations, many lifespan associated genes, genetic mechanisms and pathways have been demonstrated during last decades. In the present review, we have evaluated many human genes and their non-human orthologs established for their role in the regulation of lifespan. The study has included more than fifty genes reported in the literature for their contributions to the longevity of life. Intact genomic DNA is essential for the life activities at the level of cell, tissue, and organ. Nucleic acids are vulnerable to oxidative stress, chemotherapies, and exposure to radiations. Efficient DNA repair mechanisms are essential for the maintenance of genomic integrity, damaged DNA is not replicated and transferred to next generations rather the presence of deleterious DNA initiates signaling cascades leading to the cell cycle arrest or apoptosis. DNA modifications, DNA methylation, histone methylation, histone acetylation and DNA damage can eventually lead towards apoptosis. The importance of calorie restriction therapy in the extension of lifespan has also been discussed. The role of pathways involved in the regulation of lifespan such as DAF-16/FOXO (forkhead box protein O1), TOR and JNK pathways has also been particularized. The study provides an updated account of genetic factors associated with the extended lifespan and their interactive contributory role with cellular pathways.

Positive selection and enhancer evolution shaped lifespan and body mass in great apes

Within primates, the great apes are outliers both in terms of body size and lifespan, since they include the largest and longest-lived species in the order. Yet, the molecular bases underlying such features are poorly understood. Here, we leveraged an integrated approach to investigate multiple sources of molecular variation across primates, focusing on over ten thousand genes, including ∼1,500 previously associated with lifespan, and additional ∼9,000 for which an association with longevity has never been suggested. We analyzed dN/dS rates, positive selection, gene expression (RNA-seq) and gene regulation (ChIP-seq). By analyzing the correlation between dN/dS, maximum lifespan and body mass we identified 276 genes whose rate of evolution positively correlates with maximum lifespan in primates. Further, we identified 5 genes, important for tumor suppression, adaptive immunity, metastasis and inflammation, under positive selection exclusively in the great ape lineage. RNA-seq data, generated from the liver of six species representing all the primate lineages, revealed that 8% of ∼1,500 genes previously associated with longevity are differentially expressed in apes relative to other primates. Importantly, by integrating RNA-seq with ChIP-seq for H3K27ac (which marks active enhancers), we show that the differentially expressed longevity genes are significantly more likely than expected to be located near a novel "ape-specific" enhancer. Moreover, these particular ape-specific enhancers are enriched for young transposable elements, and specifically SINE-Vntr-Alus (SVAs). In summary, we demonstrate that multiple evolutionary forces have contributed to the evolution of lifespan and body size in primates.

Coevolution of Brain, Culture, and Lifespan: Insights from Computer Simulations

Humans possess a number of traits that are rare or absent in other primates, including large brain size, culture, language, extended lifespan (LS), and long post-reproductive period. Here, we use a computer model, TribeSim, originally designed to explore the autocatalytic coevolution of the hominin brain and culture within the framework of the "cultural drive" theory, to find out how culture and brain could coevolve with LS (or aging rate). We show that in the absence of culture, the evolution of LS depends on the intensity of the between-group competition (BGC): strong BGC results in shorter LS. Culture, however, favors genetic evolution of longer LS even if the BGC is strong. Extended LS, in turn, enhances cultural development, thus creating positive feedback. Cultural evolution of LS (accumulation of survival-enhancing or survival-impairing knowledge) differs from the genetic evolution of the same trait, partially because "memes" (ideas, skills, and behaviors) that reduce the risk of death tend to spread in the meme pool even if it is not beneficial to genes. Consequently, cultural evolution of aging tends to result in longer LS than genetic evolution of the same trait. If LS evolves both genetically and culturally, the typical result is a society in which young individuals, due to their genetic predisposition, lead a riskier lifestyle in exchange for a chance to gain additional resources, but accumulate survival-enhancing knowledge with age. Simulations also showed that cultural evolution of adaptive behaviors can contribute to the genetic evolution of a long post-reproductive period, e.g., if the presence of knowledgeable long-livers increases the competitiveness of the group.

A Review of the Current Mammalian Models of Alzheimer's Disease and Challenges That Need to Be Overcome

Alzheimer's disease (AD) is one of the looming health crises of the near future. Increasing lifespans and better medical treatment for other conditions mean that the prevalence of this disease is expected to triple by 2050. The impact of AD includes both the large toll on individuals and their families as well as a large financial cost to society. So far, we have no way to prevent, slow, or cure the disease. Current medications can only alleviate some of the symptoms temporarily. Many animal models of AD have been created, with the first transgenic mouse model in 1995. Mouse models have been beset by challenges, and no mouse model fully captures the symptomatology of AD without multiple genetic mutations and/or transgenes, some of which have never been implicated in human AD. Over 25 years later, many mouse models have been given an AD-like disease and then 'cured' in the lab, only for the treatments to fail in clinical trials. This review argues that small animal models are insufficient for modelling complex disorders such as AD. In order to find effective treatments for AD, we need to create large animal models with brains and lifespan that are closer to humans, and underlying genetics that already predispose them to AD-like phenotypes.

The tumor suppression theory of aging

Despite continued increases in human life expectancy, the factors determining the rate of human biological aging remain unknown. Without understanding the molecular mechanisms underlying aging, efforts to prevent aging are unlikely to succeed. The tumor suppression theory of aging introduced here proposes somatic mutation as the proximal cause of aging, but postulates that oncogenic transformation and clonal expansion, not functional impairment, are the relevant consequences of somatic mutation. Obesity and caloric restriction accelerate and decelerate aging due to their effect on cell proliferation, during which most mutations arise. Most phenotypes of aging are merely tumor-suppressive mechanisms that evolved to limit malignant growth, the dominant age-related cause of death in early and middle life. Cancer limits life span for most long-lived mammals, a phenomenon known as Peto's paradox. Its conservation across species demonstrates that mutation is a fundamental but hard limit on mammalian longevity. Cell senescence and apoptosis and differentiation induced by oncogenes, telomere shortening or DNA damage evolved as a second line of defense to limit the tumorigenic potential of clonally expanding cells, but accumulating senescent cells, senescence-associated secretory phenotypes and stem cell exhaustion eventually cause tissue dysfunction and the majority, if not most, phenotypes of aging.

Aging Successfully: Possible in Principle? Possible for all? Desirable for all?

The human lifespan is constantly increasing across the world. Therefore, the question whether aging can take a "successful" route likely never has been as up-to-date as today. Still, gerontology continues to struggle with the concept of successful aging. In part I of this work, I outline six models of successful aging currently most discussed in aging science. Next, I compare the models according to four indicator domains: Psychologically oriented, socially oriented, bio-physical functioning oriented, and other. In part II, I address three key questions related to successful aging: Is successful aging possible in principle? Is it possible for all? Is it desirable for all? Regarding the first question, the conclusion based on empirical data is that across all models except the biological model aging successfully is possible in principle. Hence, I answer this question with a "YES, BUT." Successful aging at the bio-level so far seems very limited. In terms of question 2, expecting largely increasing portions of older adults fulfilling various of the so far established criteria of aging successfully in the future seem overly optimistic. Hence, I answer this question with "NO." For question 3, I critique the at first glance obvious persuasiveness of successful aging as a generally to be achieved end state. For example, it may be that norms of successful aging undermine old age's cultural richness in the future. Hence, I answer this question with "NOT SURE."

Integrated phylogeny of the human brain and pathobiology of Alzheimer's disease: A unifying hypothesis

The disproportionate evolutionary expansion of the human cerebral cortex with reinforcement of cholinergic innervations warranted a major rise in the functional and metabolic load of the conserved basal forebrain (BF) cholinergic system. Given that acetylcholine (ACh) regulates properties of the microtubule-associated protein (MAP) tau and promotes non-amyloidogenic processing of amyloid precursor protein (APP), growing neocortex predicts higher demands for ACh, while the emerging role of BF cholinergic projections in Aβ clearance infers greater exposure of source neurons and their innervation fields to amyloid pathology. The higher exposure of evolutionary most recent cortical areas to the amyloid pathology of Alzheimer's disease (AD) with synaptic impairments and atrophy, therefore, might involve attenuated homeostatic effects of BF cholinergic projections, in addition to fall-outs of inherent processes of expanding association areas. This unifying model, thus, views amyloid pathology and loss of cholinergic cells as a quid pro quo of the allometric evolution of the human brain, which in combination with increase in life expectancy overwhelm the fine homeostatic balance and trigger the disease process.

Insulin-like Growth Factor 1 and Prolactin Levels in Chimpanzees (Pan troglodytes) Across the Lifespan

As human and chimpanzee genomes show high homology for IGF1 and PRL, we analyzed the sera of 367 healthy chimpanzees obtained during routine physical examinations in a single colony and measured chimpanzee insulin-like growth factor (IGF)-1 and prolactin (PRL) levels across the lifespan using standard human immunoassays. Assuming chimpanzee IGF-1 levels peak during puberty as in humans, we randomly defined puberty as the age at which most IGF-1 levels were equal to or above the 90^th percentile for each sex (males, ages ≥7.00 but <9.20 years; females, ≥5.00 but <8.00 years). IGF-1 levels steadily increased at a similar rate in juvenile males and females and peaked in puberty, strongly correlating with age, then slowly decreased faster in adult males than in adult females. As a group, males had a higher mean IGF-1 level than did females, but comparison by age category showed similar mean IGF-1 levels in males and females. PRL levels increased with age in females more than in males and levels were twice as high in females than in males. One pubertal male reported to have short stature had lower IGF-1 and weight compared with other males in the age group, confirming suspected growth hormone deficiency; a second male of normal height but low IGF-1 may have had delayed puberty. Overall, results show that differences in IGF-1 levels over the lifespan in this cohort of chimpanzees largely mimic those seen in humans, while patterns of PRL changes are less similar.

Disease and Disapproval: COVID-19 Concern is Related to Greater Moral Condemnation

Prior research has indicated that disease threat and disgust are associated with harsher moral condemnation. We investigated the role of a specific, highly salient health concern, namely the spread of the coronavirus, and associated COVID-19 disease, on moral disapproval. We hypothesized that individuals who report greater subjective worry about COVID-19 would be more sensitive to moral transgressions. Across three studies (N = 913), conducted March-May 2020 as the pandemic started to unfold in the United States, we found that individuals who were worried about contracting the infectious disease made harsher moral judgments than those who were relatively less worried. This effect was not restricted to transgressions involving purity, but extended to transgressions involving harm, fairness, authority, and loyalty, and remained when controlling for political orientation. Furthermore, for Studies 1 and 2 the effect also was robust when taking into account the contamination subscale of the Disgust Scale-Revised. These findings add to the growing literature that concrete threats to health can play a role in abstract moral considerations, supporting the notion that judgments of wrongdoing are not based on rational thought alone.

Outcomes of Surgical and Nonsurgical Treatment for Colorectal Cancer in Nonagenarian Patients

PURPOSE

This study is aimed to evaluate the clinical outcomes of surgical treatment for nonagenarian patients with colorectal cancer.

METHODS

This retrospective single-center study included patients diagnosed with colorectal cancer at the age of ≥90 years between 2004 and 2018. Patient demographics were compared between the operation and nonoperation groups (NOG). Perioperative outcomes, histopathological outcomes, and postoperative complications were evaluated. Overall survival was analyzed using Kaplan-Meier methods and log-rank test.

RESULTS

A total of 31 patients were included (16 men and 15 women), and the median age was 91 (range: 90-96) years. The number of patients who underwent surgery and who received nonoperative management was 20 and 11, respectively. No statistical differences in baseline demographics were observed between both groups. None of these patients were treated with perioperative chemotherapy or radiotherapy. Surgery comprised 18 (90.0%) colectomies and 2 (10.0%) transanal excisions. Short-term (≤30 days) and long-term (31-90 days) postoperative complications occurred in 7 (35.0%) and 4 (20.0%) patients, respectively. No complications needed reoperation, such as anastomosis leakage or bleeding. No postoperative mortality occurred within 30 days: 90-day postoperative mortality occurred in two patients (10.0%), respectively. The median overall survival of the operation group was 31.6 (95% confidence interval: 26.7-36.5) and that of NOG was 12.5 months (95% CI: 2.4-22.6) (P = 0.012).

CONCLUSION

Surgical treatment can be considered in carefully selected nonagenarian patients with colorectal cancer in terms of acceptable postoperative morbidity, with better overall survival than the nonsurgical treatment.

Why women have more autoimmune diseases than men: An evolutionary perspective

Women have up to a fourfold increase in risk for autoimmune disease compared to men. Many explanations have been proposed, including sex hormones, the X chromosome, microchimerism, environmental factors, and the microbiome. However, the mechanism for this autoimmune sex bias remains obscure. In this manuscript, we evaluate the hypothesis that qualitative or quantitative differences in circulating antibodies may explain, at least in part, the pathogenesis of autoimmune disease and its sex bias-especially when considering an evolutionary perspective. Indeed, women have higher absolute levels of antibodies than men, and (auto)antibodies are also associated with most autoimmune diseases. Several facts suggest differences in antibodies may cause increased prevalence of autoimmune disease in women. First, the association between increased quantities of serum antibodies and increased prevalence of autoimmunity is found not only in women, but also in men with Klinefelter syndrome. Second, both serum antibody levels and autoimmunity spike in the postpartum period. Third, a dose-response effect exists between parity and both serum antibodies and prevalence of autoimmune disease. Fourth, many biologically plausible mechanisms explain the association, such as T cell-dependent activation of B cells and/or VGLL3. The evolutionary underpinning of increased antibodies in women is likely to be protection of offspring from infections. Overall, this evolutionary paradigm can help explain why the phenomenon of autoimmunity occurs preferentially in women and raises the possibility of new treatment options.

Age-related changes in chimpanzee (Pan troglodytes) cognition: Cross-sectional and longitudinal analyses

Chimpanzees are the species most closely related to humans, yet age-related changes in brain and cognition remain poorly understood. The lack of studies on age-related changes in cognition in chimpanzees is particularly unfortunate in light of the recent evidence demonstrating that this species naturally develops Alzheimer's disease (AD) neuropathology. Here, we tested 213 young, middle-aged, and elderly captive chimpanzees on the primate cognitive test battery (PCTB), a set of 13 tasks that assess physical and social cognition in nonhuman primates. A subset of these chimpanzees (n = 146) was tested a second time on a portion of the PCTB tasks as a means of evaluating longitudinal changes in cognition. Cross-sectional analyses revealed a significant quadratic association between age and cognition with younger and older chimpanzees performing more poorly than middle-aged individuals. Longitudinal analyses showed that the oldest chimpanzees at the time of the first test showed the greatest decline in cognition, although the effect was mild. The collective data show that chimpanzees, like other nonhuman primates, show age-related decline in cognition. Further investigations into whether the observed cognitive decline is associated with AD pathologies in chimpanzees would be invaluable in understanding the comparative biology of aging and neuropathology in primates.

Eco-evolutionary dynamics of cooperation in the presence of policing

Ecology and evolution are inherently linked, and studying a mathematical model that considers both holds promise of insightful discoveries related to the dynamics of cooperation. In the present article, we use the prisoner's dilemma (PD) game as a basis for long-term apprehension of the essential social dilemma related to cooperation among unrelated individuals. We upgrade the contemporary PD game with an inclusion of evolution-induced act of punishment as a third competing strategy in addition to the traditional cooperators and defectors. In a population structure, the abundance of ecologically-viable free space often regulates the reproductive opportunities of the constituents. Hence, additionally, we consider the availability of free space as an ecological footprint, thus arriving at a simple eco-evolutionary model, which displays fascinating complex dynamics. As possible outcomes, we report the individual dominance of cooperators and defectors as well as a plethora of mixed states, where different strategies coexist followed by maintaining the diversity in a socio-ecological framework. These states can either be steady or oscillating, whereby oscillations are sustained by cyclic dominance among different combinations of cooperators, defectors, and punishers. We also observe a novel route to cyclic dominance where cooperators, punishers, and defectors enter a coexistence via an inverse Hopf bifurcation that is followed by an inverse period doubling route.