The 'Jekyll and Hyde' of Gluconeogenesis: Early Life Adversity, Later Life Stress, and Metabolic Disturbances

Neurobiological and psychological factors to depression

Major Depressive Disorder (MDD) is a common condition with complex psychological and biological background. While its aetiology is still unclear, chronic stress stands amongst major risk factors to MDD pathogenesis. When researching on MDD, it is necessary to be familiar with the neurobiological effects of several prominent contributors to the chronic stress factor experienced across hypothalamic-pituitary-adrenal (HPA) axis, neurotransmission, immune system reflexivity, and genetic alterations. Bi-directional flow of MDD pathogenesis suggests that psychological factors produce biological effects. Here, a summary of how the MDD expresses its mechanisms of action across an overactive HPA axis, the negative impacts of reduced neurotransmitter functions, the inflammatory responses and their gene x environment interactions. This paper builds on these conceptual factors and their input towards the MDD symptomatology with a purpose of synthesising the current findings and create an integrated view of the MDD pathogenesis. Finally, relevant treatment implications will be summarised, along with recommendations to a multimodal clinical practice.

The oral microbiome is associated with HPA axis response to a psychosocial stressor

Intense psychosocial stress during early life has a detrimental effect on health-disease balance in later life. Simultaneously, despite its sensitivity to stress, the developing microbiome contributes to long-term health. Following stress exposure, HPA-axis activation regulates the "fight or flight" response with the release of glucose and cortisol. Here, we investigated the interaction between the oral microbiome and the stress response. We used a cohort of 115 adults, mean age 24, who either experienced institutionalisation and adoption (n = 40) or were non-adopted controls (n = 75). Glucose and cortisol measurements were taken from participants following an extended socially evaluated cold pressor test (seCPT) at multiple time points. The cohort´s oral microbiome was profiled via 16S-V4 sequencing on microbial DNA from saliva and buccal samples. Using mixed-effect linear regressions, we identified 12 genera that exhibited an interaction with host's cortisol-glucose response to stress, strongly influencing intensity and clearance of cortisol and glucose following stress exposure. Particularly, the identified taxa influenced the glucose and cortisol release profiles and kinetics following seCPT exposure. In conclusion, our study provided evidence for the oral microbiome modifying the effect of stress on the HPA-axis and human metabolism, as shown in glucose-cortisol time series data.

Early-life influenza A (H1N1) infection independently programs brain connectivity, HPA AXIS and tissue-specific gene expression profiles

Early-life adversity covers a range of physical, social and environmental stressors. Acute viral infections in early life are a major source of such adversity and have been associated with a broad spectrum of later-life effects outside the immune system or "off-target". These include an altered hypothalamus-pituitary-adrenal (HPA) axis and metabolic reactions. Here, we used a murine post-natal day 14 (PND 14) Influenza A (H1N1) infection model and applied a semi-holistic approach including phenotypic measurements, gene expression arrays and diffusion neuroimaging techniques to investigate HPA axis dysregulation, energy metabolism and brain connectivity. By PND 56 the H1N1 infection had been resolved, and there was no residual gene expression signature of immune cell infiltration into the liver, adrenal gland or brain tissues examined nor of immune-related signalling. A resolved early-life H1N1 infection had sex-specific effects. We observed retarded growth of males and altered pre-stress (baseline) blood glucose and corticosterone levels at PND42 after the infection was resolved. Cerebral MRI scans identified reduced connectivity in the cortex, midbrain and cerebellum that were accompanied by tissue-specific gene expression signatures. Gene set enrichment analysis confirmed that these were tissue-specific changes with few common pathways. Early-life infection independently affected each of the systems and this was independent of HPA axis or immune perturbations.

Increased Cardiometabolic Risk in Healthy Young Adults With Early Life Stress

OBJECTIVE

This study aimed to evaluate the relationship between early life stress (ELS) and metabolic risk in healthy young adults and assess the role of health behaviors.

METHODS

Young adults aged 18 to 40 years ( N = 190) with no medical conditions or medication usage were recruited from the community. Participants with ELS ( N = 113) had a history of childhood maltreatment, and most also experienced parental loss ( n = 88). Controls ( N = 77) had no history of maltreatment or parental loss. Standardized interviews and self-reports assessed demographics, adversity, medical/psychiatric history, and health behaviors. Blood pressure and anthropometrics were measured, and fasting plasma assayed for lipid profiles, glucose, insulin level, and hemoglobin A 1c . We calculated both a clinical cut-point and continuous composite metabolic risk score based on clinical risk factors and the mean of z scores of each measure, respectively.

RESULTS

ELS was significantly associated with increased clinical cut-point ( β = 0.68, 95% confidence interval [CI] = 0.20-1.17, p = .006) and continuous ( β = 0.23, 95% CI = 0.08-0.038, p = .003) composite metabolic risk scores. On sensitivity analysis, the association of ELS with the continuous composite metabolic risk score was reduced to a trend after adjusting for a range of psychosocial and health predictors ( β = 0.18, 95% CI = 0.00-0.36, p = .053), with both diet and college graduate status significant in the model.

CONCLUSIONS

Healthy young adults with a history of ELS have increased metabolic risk scores as compared with controls. This relationship may be partially due to health behaviors and socioeconomic factors. These findings underline that ELS is an early contributor to metabolic risk.

Brain insulin signaling as a potential mediator of early life adversity effects on physical and mental health

In numerous brain structures, insulin signaling modulates the homeostatic processes, sensitivity to reward pathways, executive function, memory, and cognition. Through human studies and animal models, mounting evidence implicates central insulin signaling in the metabolic, physiological, and psychological consequences of early life adversity. In this review, we describe the consequences of early life adversity in the brain where insulin signaling is a key factor and how insulin may moderate the effects of adversity on psychiatric and cardio-metabolic health outcomes. Further understanding of how early life adversity and insulin signaling impact specific brain regions and mental and physical health outcomes will assist in prevention, diagnosis, and potential intervention following early life adversity.

Early life adversities and lifelong health outcomes: A review of the literature on large, social, long-lived nonhuman mammals

Social nonhuman animals are powerful models for studying underlying factors related to lifelong health outcomes following early life adversities (ELAs). ELAs can be linked to lifelong health outcomes depending on the species, system, sensitive developmental periods, and biological pathways. This review focuses on the literature surrounding ELAs and lifelong health outcomes in large, social, relatively long-lived nonhuman mammals including nonhuman primates, canids, hyenas, elephants, ungulates, and cetaceans. These mammals, like humans but unlike the most-studied rodent models, have longer life histories, complex social structures, larger brains, and comparable stress and reproductive physiology. Collectively, these features make them compelling models for comparative aging research. We review studies of caregiver, social, and ecological ELAs, often in tandem, in these mammals. We consider experimental and observational studies and what each has contributed to our knowledge of health across the lifespan. We demonstrate the continued and expanded need for comparative research to inform about the social determinants of health and aging in both humans and nonhuman animals.

Adverse childhood experiences and lifelong health

With the advent of the sustainable development goals, the field of global child health has shifted its focus from reducing mortality to improving health, nutrition and development outcomes - often measured as human capital. A growing knowledge of the biology of development and neuroscience has highlighted the importance of adverse environmental exposures, collectively termed adverse childhood experiences (ACEs) on health outcomes. ACEs are associated with short-term, medium-term and long-term negative consequences for health and development and their effects may be multiplicative, especially during critical periods of sensitivity and developmental plasticity. Some of these effects are compounded by emerging global threats such as climate change, conflict and population displacement. In this Review, we discuss the key mechanisms linking ACEs to health outcomes and consider promising strategies to prevent and mitigate their effects, highlighting evidence from programs in low-income and middle-income countries. Finally, we emphasize the need for early recognition of ACEs and delivery of packages of interventions spanning key sectors such as health, education, women's empowerment and social protection.

The circadian rhythm: an influential soundtrack in the diabetes story

Type 2 Diabetes Mellitus (T2DM) has been the main category of metabolic diseases in recent years due to changes in lifestyle and environmental conditions such as diet and physical activity. On the other hand, the circadian rhythm is one of the most significant biological pathways in humans and other mammals, which is affected by light, sleep, and human activity. However, this cycle is controlled via complicated cellular pathways with feedback loops. It is widely known that changes in the circadian rhythm can alter some metabolic pathways of body cells and could affect the treatment process, particularly for metabolic diseases like T2DM. The aim of this study is to explore the importance of the circadian rhythm in the occurrence of T2DM via reviewing the metabolic pathways involved, their relationship with the circadian rhythm from two perspectives, lifestyle and molecular pathways, and their effect on T2DM pathophysiology. These impacts have been demonstrated in a variety of studies and led to the development of approaches such as time-restricted feeding, chronotherapy (time-specific therapies), and circadian molecule stabilizers.

Association between early life adversity and allostatic load in girls with precocious puberty

CONTEXT

The mechanisms underlying the elevated long-term health risk in girls with precocious puberty remain unclear, but might result from physiological wear and tear associated with greater exposure to early life adversity.

OBJECTIVE

This study aims to explore early life adversity in girls with precocious puberty and its association with allostatic load.

METHODS

Early life adversity and hair cortisol concentration were measured among 213 girls with precocious puberty (8.21 ± 1.07). Allostatic load score is constructed by using 13 physiological biomarkers representing four systems and hair cortisol concentration. Multivariate linear regression models have estimated the associations between cumulative early life adversity exposure with total and system-specific allostatic load scores. Associations between cumulative early life adversity and the risk of high allostatic load (3 + high-risk biomarkers) were tested using binary logistics regression.

RESULTS

More than two-thirds (67.6%) of girls with central precocious puberty reported two or more early life adversity exposure. Compared to those with no early life adversity exposure, girls who reported early life adversity score ≥ 2 had significantly higher total allostatic load score (β: 1.20-1.64, P < 0.001). Metabolic system was more sensitive to cumulative early life adversity exposure, each form of early life adversity exposure was associated with 0.48-unit increases in metabolic allostatic load score (95%CI: 0.06, 0.90, P = 0.026). Girls reported early life adversity score ≥ 3 were three times more likely to have a high allostatic load compared with those without early life adversity exposure in both unadjusted and adjusted models (OR_adjusted=3.83, 95%CI: 1.17, 12.55, P = 0.001).

CONCLUSION

Multisystem physiological dysregulation is observed in girls with central precocious puberty, which might result from cumulative wear-and-tear associated with early life adversity.

Racial/Ethnic Differences in Associations Between Traumatic Childhood Experiences and Both Metabolic Syndrome Prevalence and Type 2 Diabetes Risk Among a Cohort of U.S. Women

OBJECTIVE

Childhood adversity has been associated with metabolic syndrome (MetS) and type 2 diabetes risk in adulthood. However, studies have yet to investigate traumatic childhood experiences (TCEs) beyond abuse and neglect (e.g., natural disaster) while considering potential racial/ethnic differences.

RESEARCH DESIGN AND METHODS

To investigate race/ethnicity as a potential modifier of the association between TCEs, MetS, and type 2 diabetes, we used prospectively collected data from 42,173 eligible non-Hispanic White (NHW; 88%), Black/African American (BAA; 7%), and Hispanic/Latina (4%) Sister Study participants (aged 35-74 years) enrolled from 2003 to 2009. A modified Brief Betrayal Trauma Survey captured TCEs. At least three prevalent metabolic abnormalities defined MetS, and self-report of a new diagnosis during the study period defined type 2 diabetes. We used adjusted Cox proportional hazards regression to estimate hazard ratios (HRs) and 95% CIs for type 2 diabetes over a mean ± SD follow-up of 11.1 ± 2.7 years, overall and by race/ethnicity. We also tested for modification and mediation by MetS.

RESULTS

Incident cases of type 2 diabetes were reported (n = 2,479 among NHW, 461 among BAA, and 281 among Latina participants). Reporting any TCEs (50% among NHW, 53% among BAA, and 51% among Latina participants) was associated with a 13% higher risk of type 2 diabetes (HR 1.13; 95% CI 1.04-1.22). Associations were strongest among Latina participants (HR 1.64 [95% CI 1.21-2.22] vs. 1.09 for BAA and NHW). MetS was not a modifier but mediated (indirect effect, HR 1.01 [95% CI 1.00-1.01]; P = 0.02) the overall association.

CONCLUSIONS

TCE and type 2 diabetes associations varied by race/ethnicity and were partially explained by MetS.

The neurobiology of pain and facial movements in rodents: Clinical applications and current research

One of the most controversial aspects of the use of animals in science is the production of pain. Pain is a central ethical concern. The activation of neural pathways involved in the pain response has physiological, endocrine, and behavioral consequences, that can affect both the health and welfare of the animals, as well as the validity of research. The strategy to prevent these consequences requires understanding of the nociception process, pain itself, and how assessment can be performed using validated, non-invasive methods. The study of facial expressions related to pain has undergone considerable study with the finding that certain movements of the facial muscles (called facial action units) are associated with the presence and intensity of pain. This review, focused on rodents, discusses the neurobiology of facial expressions, clinical applications, and current research designed to better understand pain and the nociceptive pathway as a strategy for implementing refinement in biomedical research.

Adult Health and Early Life Adversity: Behind the Curtains of Maternal Care Research

The quality of one's adult health and the chances of maintaining cognitive ability in aging stem directly from the quality of care one receives as an infant. Formal studies of maternal care can be traced back at least a century. Revelations of behavioral outcomes after maternal deprivation in primates were followed by discoveries of systemic and brain growth factors mediated by the caregiver-offspring relationship in rodents. More recently, much of the genetic/epigenetic bases of maternal care has been defined and positively linked to adult health and cognitive ability in senescence. The history of this field is both tragic and fascinating. The early primate work, while informative, was abusive. The initial rodent work was ridiculed before its importance was recognized. The final lesson learned is that infant/toddler care matters a lot. Today, we have a better understanding of the biology underlying maternal care and its transmission across generations as well as a scientific basis for massaging premature infants and hugging our children.

The Role of Bioactive Compounds from Dietary Spices in the Management of Metabolic Syndrome: An Overview

Metabolic syndrome (MetS) is a combination of physiologically dysregulated parameters that can include elevated fasting blood glucose, high blood pressure, central obesity, increased triglyceride levels, insulin resistance, diabetes, elevated low density lipoprotein levels, and reduced high density lipoprotein levels in the blood. Effective clinical management of MetS is critical as it is strongly associated with long lasting and fatal complications in patients. Alongside standard care of lifestyle changes and medication, dietary supplements derived from herbal resources could be an alternative therapeutic strategy that is safe, efficient, culturally acceptable, and has few side effects. Of the dietary supplements, spicy foods have always been considered a great source of functional bioactive compounds. Herbal therapy is broadly used in many countries as a treatment or as a preventive measure in the management of MetS risk factors, including blood glucose, blood pressure, and blood lipid levels. Herein, an attempt is made to evaluate the recent studies in the management of MetS with herbal alternatives, and to explore the possibility of their use as therapeutic treatments or supplements.

Sex Dimorphic Responses of the Hypothalamus-Pituitary-Thyroid Axis to Energy Demands and Stress

The hypothalamus-pituitary-thyroid-axis (HPT) is one of the main neuroendocrine axes that control energy expenditure. The activity of hypophysiotropic thyrotropin releasing hormone (TRH) neurons is modulated by nutritional status, energy demands and stress, all of which are sex dependent. Sex dimorphism has been associated with sex steroids whose concentration vary along the life-span, but also to sex chromosomes that define not only sexual characteristics but the expression of relevant genes. In this review we describe sex differences in basal HPT axis activity and in its response to stress and to metabolic challenges in experimental animals at different stages of development, as well as some of the limited information available on humans. Literature review was accomplished by searching in Pubmed under the following words: "sex dimorphic" or "sex differences" or "female" or "women" and "thyrotropin" or "thyroid hormones" or "deiodinases" and "energy homeostasis" or "stress". The most representative articles were discussed, and to reduce the number of references, selected reviews were cited.

Unbiased Screening Identifies Functional Differences in NK Cells After Early Life Psychosocial Stress

Early Life Adversity (ELA) is closely associated with the risk for developing diseases later in life, such as autoimmune diseases, type-2 diabetes and cardiovascular diseases. In humans, early parental separation, physical and sexual abuse or low social-economic status during childhood are known to have great impact on brain development, in the hormonal system and immune responses. Maternal deprivation (MD) is the closest animal model available to the human situation. This paradigm induces long lasting behavioral effects, causes changes in the HPA axis and affects the immune system. However, the mechanisms underlying changes in the immune response after ELA are still not fully understood. In this study we investigated how ELA changes the immune system, through an unbiased analysis, viSNE, and addressed specially the NK immune cell population and its functionality. We have demonstrated that maternal separation, in both humans and rats, significantly affects the sensitivity of the immune system in adulthood. Particularly, NK cells’ profile and response to target cell lines are significantly changed after ELA. These immune cells in rats are not only less cytotoxic towards YAC-1 cells, but also show a clear increase in the expression of maturation markers after 3h of maternal separation. Similarly, individuals who suffered from ELA display significant changes in the cytotoxic profile of NK cells together with decreased degranulation capacity. These results suggest that one of the key mechanisms by which the immune system becomes impaired after ELA might be due to a shift on the senescent state of the cells, specifically NK cells. Elucidation of such a mechanism highlights the importance of ELA prevention and how NK targeted immunotherapy might help attenuating ELA consequences.

Energy metabolism in major depressive disorder: Recent advances from omics technologies and imaging

Major depressive disorder (MDD) is a serious psychiatric disorder that associated with high rate of disability and increasing suicide rate, and the pathogenesis is still unclear. Many researches showed that the energy metabolism of patients with depression is impaired, which may be the direction of depression treatment. In this review, we focus on the "omics" technologies such as genomics, proteomics, transcriptomics and metabolomics, as well as imaging, and the progress on energy metabolism of MDD. These findings indicate that abnormal energy metabolism is one of the important mechanisms for the occurrence and development of depression. Although the research on various mechanisms of depression is still ongoing, the rapid development of new technologies and the joint use of various technologies will help to clarify the pathogenesis of depression and explore efficient diagnosis and treatment methods.

Stress responses across the scales of life: Towards a universal theory of biological stress

Although biological systems are more complex and can actively respond to their environment, an effective entry point to the development of a universal theory of biological stress are the physical concepts of stress and strain. If you apply stress to the end of a beam of steel, strain will accumulate within that steel beam. If the stress is weak, that strain will disappear when the force is removed and the beam will return to its original state of form and functionality. If the stress is more severe, the strain becomes permanent and the beam will be deformed, potentially losing some degree of functionality. In extremely stressful situations, the beam will break and lose most or all of its original functional capabilities. Although this stress-strain theory applies to the abiotic, stress and strain are also rules of life and directly relate to the form and function of living organisms. The main difference is that life can react and adjust to stress and strain to maintain homeostasis within a range of limits. Here, we summarize the rules of stress and strain in living systems ranging from microbes to multicellular organisms to ecosystems with the goal of identifying common features that may underlie a universal biological theory of stress. We then propose to establish a range of experimental, observational, and analytical approaches to study stress across scales, including synthetic microbial communities that mimic many of the essential characteristics of living systems, thereby enabling a universal theory of biological stress to be experimentally validated without the constraints of timescales, ethics, or cost found when studying other species or scales of life. Although the range of terminology, theory, and methodology used to study stress and strain across the scales of life presents a formidable challenge to creating a universal theory of biological stress, working towards such a theory that informs our understanding of the simultaneous and interconnected unicellular, multicellular, organismal, and ecosystem stress responses is critical as it will improve our ability to predict how living systems respond to change, thus informing solutions to current and future environmental and human health challenges.