T Cell Immunosenescence in Aging, Obesity, and Cardiovascular Disease

Macrophage senescence in health and diseases

Macrophage senescence, manifested by the special form of durable cell cycle arrest and chronic low-grade inflammation like senescence-associated secretory phenotype, has long been considered harmful. Persistent senescence of macrophages may lead to maladaptation, immune dysfunction, and finally the development of age-related diseases, infections, autoimmune diseases, and malignancies. However, it is a ubiquitous, multi-factorial, and dynamic complex phenomenon that also plays roles in remodeled processes, including wound repair and embryogenesis. In this review, we summarize some general molecular changes and several specific biomarkers during macrophage senescence, which may bring new sight to recognize senescent macrophages in different conditions. Also, we take an in-depth look at the functional changes in senescent macrophages, including metabolism, autophagy, polarization, phagocytosis, antigen presentation, and infiltration or recruitment. Furthermore, some degenerations and diseases associated with senescent macrophages as well as the mechanisms or relevant genetic regulations of senescent macrophages are integrated, not only emphasizing the possibility of regulating macrophage senescence to benefit age-associated diseases but also has an implication on the finding of potential targets or drugs clinically.

Causal relationship between immune cells and telomere length: mendelian randomization analysis

BACKGROUND

The causal relationship between immune cells and telomere length remains controversial.

METHODS

Data on the immune cells were obtained from a previous study with 3,757 participants. Data on telomere length were obtained from the OpenGWAS database. Genome-Wide Association Study (GWAS) data were obtained and screened for eligible instrumental variables (IVs) using the TwoSampleMR package and the Phenoscanner database. To investigate the genetic causality between immune cells and telomere length, Mendelian randomization (MR) analysis and Bayesian weighted Mendelian randomization (BWMR) analysis were used.

RESULTS

MR analysis showed that there is indeed a genetic causal relationship between immune cells and telomere length. A total of 16 immune cells were successfully validated. A positive correlation was found between telomere length and immune cells such as CD28 + CD45RA + CD8br %CD8br (OR = 1.002, 95%CI: 1.000-1.003). A negative correlation was found between telomere length and immune cells such as Transitional AC (OR = 0.991, 95%CI: 0.984-0.997) (P < 0.05). Reverse MR analysis similarly confirmed that telomere length can affect four types of immune cells, including CD25 on IgD + CD24- (OR = 1.291, 95%CI: 1.060-1.571), at the genetic level.

CONCLUSION

There is indeed a mutual genetic causality between immune cells and telomere length, which will provide theoretical basis and support for more subsequent clinical studies.

Does excess body weight accelerate immune aging?

BACKGROUND

Overweight and obesity in older adults increase the risk of a range of comorbidities by sustaining chronic inflammation and thus enhancing immunosenescence. This study aimed to assess whether excess body mass affected disproportion in T lymphocytes. Therefore, the study was designed to explain whether excess body mass in older individuals affected the disproportion in numbers of T lymphocytes and whether anthropometric indices and immune risk profile expressed as CD4/CD8 ratio are diagnostically useful in the analysis of immunosenescence.

MATERIALS & METHODS

One hundred three individuals aged 73.6 ± 3.1 years were allocated to the normal body mass (body mass index (BMI) 18.5-24.9 kg/m2,n = 39), the pre-obesity (BMI 25.0-29.9 kg/m2, n = 44) or the obesity (BMI ≥30.0 kg/m2, n = 20) group, based on WHO recommendations. Details on the subjects' medical history and lifestyle were obtained by health questionnaire. Anthropometric analysis was performed by bioelectrical impedance method, biochemical analysis was made by the automatic analyzer and ELISA immunoassays, and T and B lymphocyte counts were determined by eight-parameter flow cytometry. Additionally, visceral adiposity index, body adiposity index (BAI), and body shape index (ABSI) were evaluated based on body circumference, BMI and lipid-lipoprotein profile measurements.

RESULTS

The highest percentage of CD3+CD4+ T lymphocytes (59.4 ± 12.6 %) and the lowest CD3+CD8+ T lymphocytes (31.6 ± 10.0 %) were noted in patients the obesity group. The highest cut-off value of 1.9 for CD4/CD8 ratio was recorded in the normal body mass vs pre-obesity model. CD4/CD8 ratio > 2.5 was recorded in >20 % of our pre-obesity and obesity groups while 64.5 % of the normal body mass group had CD4/CD8 ratio < 1. High diagnostic usefulness was demonstrated for both BAI and lipid accumulation product (LAP) (AUC values of ~0.800 and ~ 0.900 respectively) in three models: normal body mass vs pre-obesity, normal body mass vs obesity, and pre-obesity vs obesity.

CONCLUSION

The odds ratios (OR) for CD4/CD8 ratio in the normal body mass vs obesity model (OR = 16.1, 95%CI 3.8-93.6) indicated a potential diagnostic value of T lymphocytes for clinical prognosis of immune aging in relation to excess body weight in older adults. High values of AUC obtained for the following models: CD4/CD8 + BAI (AUC = 0.927), CD4/CD8 + LAP (AUC = 1.00), CD4/CD8 + ABSI (AUC = 0.865) proved to provide excellent discrimination between older adults with obesity and with normal body mass.

Connecting epigenetics and inflammation in vascular senescence: state of the art, biomarkers and senotherapeutics

Vascular diseases pose major health challenges, and understanding their underlying molecular mechanisms is essential to advance therapeutic interventions. Cellular senescence, a hallmark of aging, is a cellular state characterized by cell-cycle arrest, a senescence-associated secretory phenotype macromolecular damage, and metabolic dysregulation. Vascular senescence has been demonstrated to play a key role in different vascular diseases, such as atherosclerosis, peripheral arterial disease, hypertension, stroke, diabetes, chronic venous disease, and venous ulcers. Even though cellular senescence was first described in 1961, significant gaps persist in comprehending the epigenetic mechanisms driving vascular senescence and its subsequent inflammatory response. Through a comprehensive analysis, we aim to elucidate these knowledge gaps by exploring the network of epigenetic alterations that contribute to vascular senescence. In addition, we describe the consequent inflammatory cascades triggered by these epigenetic modifications. Finally, we explore translational applications involving biomarkers of vascular senescence and the emerging field of senotherapy targeting this biological process.

CD8+ T and NK cells characterized by upregulation of NPEPPS and ABHD17A are associated with the co-occurrence of type 2 diabetes and coronary artery disease

Background

Coronary artery disease (CAD) and type 2 diabetes mellitus (T2DM) are closely related. The function of immunocytes in the pathogenesis of CAD and T2DM has not been extensively studied. The quantitative bioinformatics analysis of the public RNA sequencing database was applied to study the key genes that mediate both CAD and T2DM. The biological characteristics of associated key genes and mechanism of CD8+ T and NK cells in CAD and T2DM are our research focus.

Methods

With expression profiles of GSE66360 and GSE78721 from the Gene Expression Omnibus (GEO) database, we identified core modules associated with gene co-expression relationships and up-regulated genes in CAD and T2DM using Weighted Gene Co-expression Network Analysis (WGCNA) and the 'limma' software package. The enriched pathways of the candidate hub genes were then explored using GO, KEGG and GSEA in conjunction with the immune gene set (from the MSigDB database). A diagnostic model was constructed using logistic regression analysis composed of candidate hub genes in CAD and T2DM. Univariate Cox regression analysis revealed hazard ratios (HRs), 95% confidence intervals (CIs), and p-values for candidate hub genes in diagnostic model, while CIBERSORT and immune infiltration were used to assess the immune microenvironment. Finally, monocytes from peripheral blood samples and their immune cell ratios were analyzed by flow cytometry to validate our findings.

Results

Sixteen candidate hub genes were identified as being correlated with immune infiltration. Univariate Cox regression analysis revealed that NPEPPS and ABHD17A were highly correlated with the diagnosis of CAD and T2DM. The results indicate that CD8+ T cells (p = 0.04) and NKbright cells (p = 3.7e-3) are significantly higher in healthy controls than in individuals with CAD or CAD combined with T2DM. The bioinformatics results on immune infiltration were well validated by flow cytometry.

Conclusions

A series of bioinformatics studies have shown ABHD17A and NPEPPS as key genes for the co-occurrence of CAD and T2DM. Our study highlights the important effect of CD8+ T and NK cells in the pathogenesis of both diseases, indicating that they may serve as viable targets for diagnosis and therapeutic intervention.

The pro-resolving mediator, annexin A1 regulates blood pressure, and age-associated changes in cardiovascular function and remodeling

Aging is associated with chronic, low-level inflammation which may contribute to cardiovascular pathologies such as hypertension and atherosclerosis. This chronic inflammation may be opposed by endogenous mechanisms to limit inflammation, for example, by the actions of annexin A1 (ANXA1), an endogenous glucocorticoid-regulated protein that has anti-inflammatory and pro-resolving activity. We hypothesized the pro-resolving mediator ANXA1 protects against age-induced changes in blood pressure (BP), cardiovascular structure and function, and cardiac senescence. BP was measured monthly in conscious mature (4-month) and middle-aged (12-month) ANXA1-deficient (ANXA1-/- ) and wild-type C57BL/6 mice. Body composition was measured using EchoMRI, and both cardiac and vascular function using ultrasound imaging. Cardiac hypertrophy, fibrosis and senescence, vascular fibrosis, elastin, and calcification were assessed histologically. Gene expression relevant to structural remodeling, inflammation, and cardiomyocyte senescence were also quantified. In C57BL/6 mice, progression from 4 to 12 months of age did not affect the majority of cardiovascular parameters measured, with the exception of mild cardiac hypertrophy, vascular calcium, and collagen deposition. Interestingly, ANXA1-/- mice exhibited higher BP, regardless of age. Additionally, age progression had a marked impact in ANXA1-/- mice, with markedly augmented vascular remodeling, impaired vascular distensibility, and body composition. Consistent with vascular dysfunction, cardiac dysfunction, and hypertrophy were also evident, together with markers of senescence and inflammation. These findings suggest that endogenous ANXA1 plays a critical role in regulating BP, cardiovascular function, and remodeling and delays cardiac senescence. Our findings support the development of novel ANXA1-based therapies to prevent age-related cardiovascular pathologies.

The interplay between obesity, immunosenescence, and insulin resistance

Obesity, which is the accumulation of fat in adipose tissue, has adverse impacts on human health. Obesity-related metabolic dysregulation has similarities to the metabolic alterations observed in aging. It has been shown that the adipocytes of obese individuals undergo cellular aging, known as senescence. Senescence can be transmitted to other normal cells through a series of chemical factors referred to as the senescence-associated secretory phenotype (SASP). Most of these factors are pro-inflammatory compounds. The immune system removes these senescent T-cells, but immunosenescence, which is the senescence of immune cells, disrupts the clearance of senescent T-cells. Immunosenescence occurs as a result of aging or indirectly through transmission from senescent tissues. The significant occurrence of senescence in obesity is expected to cause immunosenescence and impairs the immune response to resolve inflammation. The sustained and chronic inflammation disrupts insulin's metabolic actions in metabolic tissues. Therefore, this review focuses on the role of senescent adipocyte cells in obesity-associated immunosenescence and subsequent metabolic dysregulation. Moreover, the article suggests novel therapeutic approaches to improve metabolic syndrome by targeting senescent T-cells or using senotherapeutics.

Socioeconomic status is negatively associated with immunosenescence but positively associated with inflammation among middle-aged women in Cebu, Philippines

BACKGROUND

Socioeconomic status (SES) gradients in health are well-documented, and while biological pathways are incompletely understood, chronic inflammation and accelerated immune aging (immunosenescence) among lower SES individuals have been implicated. However, previous findings have come from samples in higher income countries, and it is unclear how generalizable they are to lower- and middle-income countries (LMIC) with different infectious exposures and where adiposity-an important contributor to chronic inflammation-might show different SES patterning. To address this gap, we explored associations between SES and inflammation and immunosenescence in a sample of women in Cebu, Philippines.

METHODS

Data came from the mothers of the Cebu Longitudinal Health and Nutrition Survey birth cohort (mean age: 47.7, range: 35-69 years). SES was measured as a combination of annual household income, education level, and assets. Chronic inflammation was measured using C-reactive protein (CRP) in plasma samples from 1,834 women. Immunosenescence was measured by the abundance of exhausted CD8T (CD8 + CD28-CD45RA-) and naïve CD8T and CD4T cells, estimated from DNA methylation in whole blood in a random subsample of 1,028. Possible mediators included waist circumference and a collection of proxy measures of pathogen exposure.

RESULTS

SES was negatively associated with the measures of immunosenescence, with slight evidence for mediation by a proxy measure for pathogen exposure from the household's drinking water source. In contrast, SES was positively associated with CRP, which was explained by the positive association with waist circumference.

CONCLUSIONS

Similar to higher income populations, in Cebu there is an SES-gradient in pathogen exposures and immunosenescence. However, lifestyle changes occurring more rapidly among higher SES individuals is contributing to a positive association between SES and adiposity and inflammation. Our results suggest more studies are needed to clarify the relationship between SES and inflammation and immunosenescence across LMIC.

A 2-week time-restricted feeding attenuates psoriasis-like lesions with reduced inflammatory cytokines and immunosenescence in mice

Psoriasis, a well-established T-cell mediated dermatosis, exhibits a robust correlation with obesity and systemic inflammation, manifesting psoriasis skin lesions and premature immunosenescence within the peripheral blood and lesion. Intermittent fasting (IF) has exhibited various beneficial effects in reducing inflammation, resisting oxidative stress and slowing ageing, as well as losing weight. A form of IF known as time-restricted feeding (TRF) restricts daily caloric intake within 4-8 h. Nonetheless, the advantageous impacts of TRF on psoriasis still require further verification. We measured the acanthosis in Imiquimod (IMQ)-induced psoriasis mice and evaluated their pathological phenotypes. Our study examined the effects of a 2-week TRF on body weight and metabolic parameters. The subsets of T cells in spleens and skin lesions were accessed by flow cytometry. Cytokines and senescence-associated genes were evaluated by immunofluorescence and RT-qPCR. RNA sequencing was conducted on skin lesions. According to our findings, a 2-week TRF attenuates psoriasis-like lesions in mice with reduced inflammatory cytokines and mitigated immunosenescence. TRF increased the counts of CD4+ Treg cells in skin lesions while reducing the counts of Th2 and Th17 cells in spleens. Furthermore, the administration of TRF resulted in a decrease in the population of CD4+ senescent T cells in both the dermis and spleens, concomitant with the expression of senescence-associated genes in spleen CD4+ T cells. The outcomes mentioned above provide valuable evidence in support of TRF for the management of psoriasis.

Reliable Hallmarks and Biomarkers of Senescent Lymphocytes

The phenomenon of accumulation of senescent adaptive immunity cells in the elderly is attracting attention due to the increasing risk of global epidemics and aging of the global population. Elderly people are predisposed to various infectious and age-related diseases and are at higher risk of vaccination failure. The accumulation of senescent cells increases age-related background inflammation, "Inflammaging", causing lymphocyte exhaustion and cardiovascular, neurodegenerative, autoimmune and cancer diseases. Here, we present a comprehensive contemporary review of the mechanisms and phenotype of senescence in the adaptive immune system. Although modern research has not yet identified specific markers of aging lymphocytes, several sets of markers facilitate the separation of the aging population based on normal memory and exhausted cells for further genetic and functional analysis. The reasons for the higher predisposition of CD8+ T-lymphocytes to senescence compared to the CD4+ population are also discussed. We point out approaches for senescent-lymphocyte-targeting markers using small molecules (senolytics), antibodies and immunization against senescent cells. The suppression of immune senescence is the most relevant area of research aimed at developing anti-aging and anti-cancer therapy for prolonging the lifespan of the global population.

Immune Diseases Associated with Aging: Molecular Mechanisms and Treatment Strategies

Aging is associated with a decline in immune function, thereby causing an increased susceptibility to various diseases. Herein, we review immune diseases associated with aging, focusing on tumors, atherosclerosis, and immunodeficiency disorders. The molecular mechanisms underlying these conditions are discussed, highlighting telomere shortening, tissue inflammation, and altered signaling pathways, e.g., the mammalian target of the rapamycin (mTOR) pathway, as key contributors to immune dysfunction. The role of the senescence-associated secretory phenotype in driving chronic tissue inflammation and disruption has been examined. Our review underscores the significance of targeting tissue inflammation and immunomodulation for treating immune disorders. In addition, anti-inflammatory medications, including corticosteroids and nonsteroidal anti-inflammatory drugs, and novel approaches, e.g., probiotics and polyphenols, are discussed. Immunotherapy, particularly immune checkpoint inhibitor therapy and adoptive T-cell therapy, has been explored for its potential to enhance immune responses in older populations. A comprehensive analysis of immune disorders associated with aging and underlying molecular mechanisms provides insights into potential treatment strategies to alleviate the burden of these conditions in the aging population. The interplay among immune dysfunction, chronic tissue inflammation, and innovative therapeutic approaches highlights the importance of elucidating these complex processes to develop effective interventions to improve the quality of life in older adults.

Immune Remodeling during Aging and the Clinical Significance of Immunonutrition in Healthy Aging

Aging is associated with changes in the immune system and the gut microbiota. Immunosenescence may lead to a low-grade, sterile chronic inflammation in a multifactorial and dynamic way, which plays a critical role in most age-related diseases. Age-related changes in the gut microbiota also shape the immune and inflammatory responses. Nutrition is a determinant of immune function and of the gut microbiota. Immunonutrion has been regarded as a new strategy for disease prevention and management, including many age-related diseases. However, the understanding of the cause-effect relationship is required to be more certain about the role of immunonutrition in supporting the immune homeostasis and its clinical relevance in elderly individuals. Herein, we review the remarkable quantitative and qualitative changes during aging that contribute to immunosenescence, inflammaging and microbial dysbiosis, and the effects on late-life health conditions. Furthermore, we discuss the clinical significance of immunonutrition in the treatment of age-related diseases by systematically reviewing its modulation of the immune system and the gut microbiota to clarify the effect of immunonutrition-based interventions on the healthy aging.

Role of cytokines and reactive oxygen species in brain aging

Aging is a complex process that produces profound effects on the brain. Although a number of external factors can promote the initiation and progression of brain aging, peripheral and central changes in the immune cells with time, also play an important role. Immunosenescence, which is an age-associated decline in immune function and Inflammaging, a low-grade inflammatory state in the aging brain contribute to an elevation in cytokine and reactive oxygen species production. In this review, we focus on the pro-inflammatory state that is established in the brain as a consequence of these two phenomena and the resulting detrimental changes in brain structure, function and repair that lead to a decline in central and neuroendocrine function.

Chronic inflammation and the hallmarks of aging

BACKGROUND

Recently, the hallmarks of aging were updated to include dysbiosis, disabled macroautophagy, and chronic inflammation. In particular, the low-grade chronic inflammation during aging, without overt infection, is defined as "inflammaging," which is associated with increased morbidity and mortality in the aging population. Emerging evidence suggests a bidirectional and cyclical relationship between chronic inflammation and the development of age-related conditions, such as cardiovascular diseases, neurodegeneration, cancer, and frailty. How the crosstalk between chronic inflammation and other hallmarks of aging underlies biological mechanisms of aging and age-related disease is thus of particular interest to the current geroscience research.

SCOPE OF REVIEW

This review integrates the cellular and molecular mechanisms of age-associated chronic inflammation with the other eleven hallmarks of aging. Extra discussion is dedicated to the hallmark of "altered nutrient sensing," given the scope of Molecular Metabolism. The deregulation of hallmark processes during aging disrupts the delicate balance between pro-inflammatory and anti-inflammatory signaling, leading to a persistent inflammatory state. The resultant chronic inflammation, in turn, further aggravates the dysfunction of each hallmark, thereby driving the progression of aging and age-related diseases.

MAIN CONCLUSIONS

The crosstalk between chronic inflammation and other hallmarks of aging results in a vicious cycle that exacerbates the decline in cellular functions and promotes aging. Understanding this complex interplay will provide new insights into the mechanisms of aging and the development of potential anti-aging interventions. Given their interconnectedness and ability to accentuate the primary elements of aging, drivers of chronic inflammation may be an ideal target with high translational potential to address the pathological conditions associated with aging.

Metabolism and senescence in the immune microenvironment of osteosarcoma: focus on new therapeutic strategies

Osteosarcoma is a highly aggressive and metastatic malignant tumor. It has the highest incidence of all malignant bone tumors and is one of the most common solid tumors in children and adolescents. Osteosarcoma tissues are often richly infiltrated with inflammatory cells, including tumor-associated macrophages, lymphocytes, and dendritic cells, forming a complex immune microenvironment. The expression of immune checkpoint molecules is also high in osteosarcoma tissues, which may be involved in the mechanism of anti-tumor immune escape. Metabolism and senescence are closely related to the immune microenvironment, and disturbances in metabolism and senescence may have important effects on the immune microenvironment, thereby affecting immune cell function and immune responses. Metabolic modulation and anti-senescence therapy are gaining the attention of researchers as emerging immunotherapeutic strategies for tumors. Through an in-depth study of the interconnection of metabolism and anti- senescence in the tumor immune microenvironment and its regulatory mechanism on immune cell function and immune response, more precise therapeutic strategies can be developed. Combined with the screening and application of biomarkers, personalized treatment can be achieved to improve therapeutic efficacy and provide a scientific basis for clinical decision-making. Metabolic modulation and anti- senescence therapy can also be combined with other immunotherapy approaches, such as immune checkpoint inhibitors and tumor vaccines, to form a multi-level and multi-dimensional immunotherapy strategy, thus further enhancing the effect of immunotherapy. Multidisciplinary cooperation and integrated treatment can optimize the treatment plan and maximize the survival rate and quality of life of patients. Future research and clinical practice will further advance this field, promising more effective treatment options for patients with osteosarcoma. In this review, we reviewed metabolic and senescence characteristics in the immune microenvironment of osteosarcoma and related immunotherapies, and provide a reference for development of more personalized and effective therapeutic strategies.

Premature T cell aging in major depression: A double hit by the state of disease and cytomegalovirus infection

Introduction

Previous research indicates that premature T cell senescence is a characteristic of major depressive disorder (MDD). However, known senescence inducing factors like cytomegalovirus (CMV) infection or, probably, childhood adversity (CA) have not been taken into consideration so far.

Objective

Differentiation and senescent characteristics of T cells of MDD patients were investigated in relation to healthy controls (HC), taking the CMV seropositivity and CA into account.

Methods

127 MDD and 113 HC of the EU-MOODSTRATIFICATION cohort were analyzed. Fluorescence activated cell sorting (FACS) analysis was performed to determine B, NK, and T cell frequencies. In a second FACS analysis, naïve, effector memory (Tem), central memory (Tcm), effector memory cells re-expressing RA (TEMRA), as well as CD28⁺ and CD27⁺ memory populations, were determined of the CD4⁺ and CD8⁺ T cell populations in a subsample (N = 35 MDD and N = 36 HC). CMV-antibody state was measured by IgG ELISA and CA by the Childhood Trauma Questionnaire.

Results

We detected a CMV-antibody positivity in 40% of MDD patients (35% HC, n. s.) with seropositive MDD cases showing a higher total childhood trauma score. Second, a higher inflation of memory CD4⁺ T helper cells in CMV seronegative patients as compared to seronegative HC and reduced numbers of naïve CD4⁺ T helper cells in CMV seropositive patients (not in CMV seropositive HC) were found. Third, a higher inflation of memory CD8⁺ T cytotoxic cells in CMV seropositive cases as compared to CMV seropositive HC, particularly of the TEMRA cells, became apparent. Higher percentages of CD4⁺ TEMRA and late stage CD27^-CD28^- TEMRA cells were similar in both HC and MDD with CMV seropositivity. Overall, apportioning of T cell subpopulations did not differ between CA positive vs negative cases.

Conclusions

MDD patients show several signs of a CMV independent "MDD specific" premature T cell aging, such as a CMV independent increase in CD4⁺ T memory cells and a latent naïve CD4 T-cell reduction and a latent CD8⁺ T-cell increase. However, these two latent T cell senescence abnormalities only become evident with CMV infection (double hit).

Inflammaging: mechanisms and role in the cardiac and vasculature

Aging triggers a wide range of cellular and molecular aberrations in the body, giving rise to inflammation and associated diseases. In particular, aging is associated with persistent low-grade inflammation even in absence of inflammatory stimuli, a phenomenon commonly referred to as 'inflammaging'. Accumulating evidence has revealed that inflammaging in vascular and cardiac tissues is associated with the emergence of pathological states such as atherosclerosis and hypertension. In this review we survey molecular and pathological mechanisms of inflammaging in vascular and cardiac aging to identify potential targets, natural therapeutic compounds, and other strategies to suppress inflammaging in the heart and vasculature, as well as in associated diseases such as atherosclerosis and hypertension.

A Role of Sodium-Glucose Co-Transporter 2 in Cardiorenal Anemia Iron Deficiency Syndrome

Heart failure, renal dysfunction, anemia, and iron deficiency affect each other and form a vicious cycle, a condition referred to as cardiorenal anemia iron deficiency syndrome. The presence of diabetes further accelerates this vicious cycle. Surprisingly, simply inhibiting sodium-glucose co-transporter 2 (SGLT2), which is expressed almost exclusively in the proximal tubular epithelial cells of the kidney, not only increases glucose excretion into the urine and effectively controls blood glucose levels in diabetes but can also correct the vicious cycle of cardiorenal anemia iron deficiency syndrome. This review describes how SGLT2 is involved in energy metabolism regulation, hemodynamics (i.e., circulating blood volume and sympathetic nervous system activity), erythropoiesis, iron bioavailability, and inflammatory set points in diabetes, heart failure, and renal dysfunction.

Cellular rejuvenation: molecular mechanisms and potential therapeutic interventions for diseases

The ageing process is a systemic decline from cellular dysfunction to organ degeneration, with more predisposition to deteriorated disorders. Rejuvenation refers to giving aged cells or organisms more youthful characteristics through various techniques, such as cellular reprogramming and epigenetic regulation. The great leaps in cellular rejuvenation prove that ageing is not a one-way street, and many rejuvenative interventions have emerged to delay and even reverse the ageing process. Defining the mechanism by which roadblocks and signaling inputs influence complex ageing programs is essential for understanding and developing rejuvenative strategies. Here, we discuss the intrinsic and extrinsic factors that counteract cell rejuvenation, and the targeted cells and core mechanisms involved in this process. Then, we critically summarize the latest advances in state-of-art strategies of cellular rejuvenation. Various rejuvenation methods also provide insights for treating specific ageing-related diseases, including cellular reprogramming, the removal of senescence cells (SCs) and suppression of senescence-associated secretory phenotype (SASP), metabolic manipulation, stem cells-associated therapy, dietary restriction, immune rejuvenation and heterochronic transplantation, etc. The potential applications of rejuvenation therapy also extend to cancer treatment. Finally, we analyze in detail the therapeutic opportunities and challenges of rejuvenation technology. Deciphering rejuvenation interventions will provide further insights into anti-ageing and ageing-related disease treatment in clinical settings.

Adaptive immune dysfunction in patients with COVID-19 and impaired kidney function during the omicron surge

BACKGROUND

Little is known about the characteristics of lymphocyte subsets and the association with patient outcomes in COVID-19 with and without impaired kidney function.

METHODS

Lymphocyte subsets were compared in COVID-19 patients with or without kidney dysfunction. The primary outcome was a composite of all-cause mortality or intensive care unit admission. Secondary outcomes included duration of viral shedding, length of hospital stay, and acute kidney injury.

RESULTS

Lymphocyte subset cell counts demonstrated the lowest in patients with severe/critical COVID-19 and kidney dysfunction. Among all lymphocyte subset parameters, Th cell count was the most significant indicator for outcomes. ROC of the combined model of Th cell count and eGFR presented better predictive value than that of the other parameters. Th cell count <394.5 cells/μl and eGFR <87.5 ml/min/1·73m² were independently associated with poor outcomes. The propensity score matching analysis revealed consistent results.

CONCLUSIONS

Reduced Th cell count and eGFR may be applied as promising predictive indicators for identifying COVID-19 patients with high risk and poor outcomes.

Age-related changes in peripheral T-cell subpopulations in elderly individuals: An observational study

The age-related decline in T-cell function among elderly individuals remains unclear. We thus investigated the interrelationship between T-cell subsets and age to identify the changes in T-cell phenotypes and develop an age prediction model for the elderly population. A total of 127 individuals aged >60 years were divided into three groups (youngest-old group, 61-70 years, n = 34; middle-old group, 71-80 years, n = 53; and oldest-old group, ≥ 81 years, n = 40). The percentage of CD8+CD28- cells (P = 0.001) was highest in the oldest-old group and then followed by the middle-old group, while the youngest-old group was the lowest. Both females and males demonstrated significant decreases in the absolute counts of CD4+CD45RA+ cells (P = 0.020; P = 0.002) and CD8+CD28+ cells (P = 0.015; P = 0.005) with age. Multivariate linear regression showed that the percentage of CD8+CD28- cells (P < 0.001) was an independent predictor of aging after adjusting for sex, body mass index, hospitalization duration, smoking, drinking, chronic medical illness, and medications at admission. In conclusion, our results suggest that aging in elderly individuals is accompanied by a decrease in the counts of T-cell subpopulations. CD8+CD28- cells may be potential targets for elderly individuals in antiaging-related immunosenescence.

Immune system modulation in aging: Molecular mechanisms and therapeutic targets

The function of the immune system declines during aging, compromising its response against pathogens, a phenomenon termed as "immunosenescence." Alterations of the immune system undergone by aged individuals include thymic involution, defective memory T cells, impaired activation of naïve T cells, and weak memory response. Age-linked alterations of the innate immunity comprise perturbed chemotactic, phagocytic, and natural killing functions, as well as impaired antigen presentation. Overall, these alterations result in chronic low-grade inflammation (inflammaging) that negatively impacts health of elderly people. In this review, we address the most relevant molecules and mechanisms that regulate the relationship between immunosenescence and inflammaging and provide an updated description of the therapeutic strategies aimed to improve immunity in aged individuals.

Cardiac damage in autoimmune diseases: Target organ involvement that cannot be ignored

Autoimmune diseases are diseases that cause damage to the body's own tissues as a result of immune dysfunction, often involving multiple organs and systems. The heart is one of the common target organs of autoimmune diseases. The whole structure of the heart can be affected, causing microcirculatory disorders, arrhythmias, pericardial damage, myocarditis, myocardial fibrosis, and impaired valvular function. However, early clinical manifestations of autoimmune heart damage are often overlooked because they are insidious or have no typical features. The damage is often severe and irreversible when symptoms are apparent, even life-threatening. Therefore, early detection and treatment of heart damage in autoimmune diseases is particularly important. Herein, we review the clinical features and mechanisms of cardiac damage in common rheumatic diseases.

Immune response to arbovirus infection in obesity

Obesity is a global health problem that affects 650 million people worldwide and leads to diverse changes in host immunity. Individuals with obesity experience an increase in the size and the number of adipocytes, which function as an endocrine organ and release various adipocytokines such as leptin and adiponectin that exert wide ranging effects on other cells. In individuals with obesity, macrophages account for up to 40% of adipose tissue (AT) cells, three times more than in adipose tissue (10%) of healthy weight individuals and secrete several cytokines and chemokines such as interleukin (IL)-1β, chemokine C-C ligand (CCL)-2, IL-6, CCL5, and tumor necrosis factor (TNF)-α, leading to the development of inflammation. Overall, obesity-derived cytokines strongly affect immune responses and make patients with obesity more prone to severe symptoms than patients with a healthy weight. Several epidemiological studies reported a strong association between obesity and severe arthropod-borne virus (arbovirus) infections such as dengue virus (DENV), chikungunya virus (CHIKV), West Nile virus (WNV), and Sindbis virus (SINV). Recently, experimental investigations found that DENV, WNV, CHIKV and Mayaro virus (MAYV) infections cause worsened disease outcomes in infected diet induced obese (DIO) mice groups compared to infected healthy-weight animals. The mechanisms leading to higher susceptibility to severe infections in individuals with obesity remain unknown, though a better understanding of the causes will help scientists and clinicians develop host directed therapies to treat severe disease. In this review article, we summarize the effects of obesity on the host immune response in the context of arboviral infections. We have outlined that obesity makes the host more susceptible to infectious agents, likely by disrupting the functions of innate and adaptive immune cells. We have also discussed the immune response of DIO mouse models against some important arboviruses such as CHIKV, MAYV, DENV, and WNV. We can speculate that obesity-induced disruption of innate and adaptive immune cell function in arboviral infections ultimately affects the course of arboviral disease. Therefore, further studies are needed to explore the cellular and molecular aspects of immunity that are compromised in obesity during arboviral infections or vaccination, which will be helpful in developing specific therapeutic/prophylactic interventions to prevent immunopathology and disease progression in individuals with obesity.

Immunosenescence, aging and successful aging

Aging induces a series of immune related changes, which is called immunosenescence, playing important roles in many age-related diseases, especially neurodegenerative diseases, tumors, cardiovascular diseases, autoimmune diseases and coronavirus disease 2019(COVID-19). However, the mechanism of immunosenescence, the association with aging and successful aging, and the effects on diseases are not revealed obviously. In order to provide theoretical basis for preventing or controlling diseases effectively and achieve successful aging, we conducted the review and found that changes of aging-related phenotypes, deterioration of immune organ function and alterations of immune cell subsets participated in the process of immunosenescence, which had great effects on the occurrence and development of age-related diseases.

Immune Alterations in a Patient With Hyperornithinemia-Hyperammonemia-Homocitrullinuria Syndrome: A Case Report

The hyperornithinemia-hyperammonemia-homocitrullinuria (HHH) syndrome is a rare autosomal recessive inborn error of the urea cycle caused by mutations in the SLC25A15 gene. Besides the well-known metabolic complications, patients often present intercurrent infections associated with acute hyperammonemia and metabolic decompensation. However, it is currently unknown whether intercurrent infections are associated with immunological alterations besides the known metabolic imbalances. Herein, we describe the case of a 3-years-old girl affected by the HHH syndrome caused by two novel SLC25A15 gene mutations associated with immune phenotypic and functional alterations. She was admitted to the hospital with an episode of recurrent otitis, somnolence, confusion, and lethargy. Laboratory tests revealed severe hyperammonemia, elevated serum levels of liver transaminases, hemostasis alterations, hyperglutaminemia and strikingly increased orotic aciduria. Noteworthy, serum protein electrophoresis showed a reduction in the gamma globulin fraction. Direct sequencing of the SLC25A15 gene revealed two heterozygous non-conservative substitutions in the exon 5: c.649G>A (p.Gly217Arg) and c.706A>G (p.Arg236Gly). In silico analysis indicated that both mutations significantly impair protein structure and function and are consistent with the patient clinical status confirming the diagnosis of HHH syndrome. In addition, the immune analysis revealed reduced levels of serum IgG and striking phenotypic and functional alterations in the T and B cell immune compartments. Our study has identified two non-previously described mutations in the SLC25A15 gene underlying the HHH syndrome. Moreover, we are reporting for the first time functional and phenotypic immunologic alterations in this rare inborn error of metabolism that would render the patient immunocompromised and might be related to the high frequency of intercurrent infections observed in patients bearing urea cycle disorders. Our results point out the importance of a comprehensive analysis to gain further insights into the underlying pathophysiology of the disease that would allow better patient care and quality of life.

The AI-Assisted Identification and Clinical Efficacy of Baricitinib in the Treatment of COVID-19

During the current pandemic, the vast majority of COVID-19 patients experienced mild symptoms, but some had a potentially fatal aberrant hyperinflammatory immune reaction characterized by high levels of IL-6 and other cytokines. Modulation of this immune reaction has proven to be the only method of reducing mortality in severe and critical COVID-19. The anti-inflammatory drug baricitinib (Olumiant) has recently been strongly recommended by the WHO for use in COVID-19 patients because it reduces the risk of progressive disease and death. It is a Janus Kinase (JAK) 1/2 inhibitor approved for rheumatoid arthritis which was suggested in early 2020 as a treatment for COVID-19. In this review the AI-assisted identification of baricitinib, its antiviral and anti-inflammatory properties, and efficacy in clinical trials are discussed and compared with those of other immune modulators including glucocorticoids, IL-6 and IL-1 receptor blockers and other JAK inhibitors. Baricitinib inhibits both virus infection and cytokine signalling and is not only important for COVID-19 management but is “non-immunological”, and so should remain effective if new SARS-CoV-2 variants escape immune control. The repurposing of baricitinib is an example of how advanced artificial intelligence (AI) can quickly identify new drug candidates that have clinical benefit in previously unsuspected therapeutic areas.

Obesity: A comorbidity-acquired immunodeficiency syndrome (CAIDS)

Accumulating data emphasize a strong link between obesity and the severity of coronavirus disease-2019 (COVID-19), including mortality. Obesity interferes with several components of the immune system including lymphoid tissue's integrity, leukocytes' development and function, complement system's activation, and the coordination of innate and adaptive immune responses. Overall, obesity results in a less efficient immune response to infectious agents. Severe acute respiratory syndrome coronavirus 2 exploits this weakened immune system in people with obesity to precipitate COVID-19, and in some cases death. It is therefore the author's recommendation that obesity should be viewed as another form of acquired immunodeficiency syndrome and be treated with the appropriate seriousness. Unlike the previously described acquired immunodeficiency syndrome (AIDS) that is caused by the Human Immunodeficiency Virus (HIV), obesity is a comorbidity-acquired immunodeficiency syndrome. People with AIDS do not die from HIV, but may die from opportunistic pathogens such as Mycobacterium tuberculosis. However, AIDS is ascribed its due importance in the course of deterioration of the patient. Similarly, obesity should be acknowledged further as a risk factor for mortality from COVID-19. Obesity is a modifiable condition and even in people with a strong genetic predisposition, lifestyle modifications can reverse obesity, and even moderate weight loss can improve the inflammatory milieu. Strong public health actions are warranted to promote lifestyle measures to reduce the burden from overweight and obesity that currently affect more than one-third of the global population, with projections alarming this may reach 55-80% within the next thirty years.

Obesity Increases Gene Expression of Markers Associated With Immunosenescence in Obese Middle-Aged Individuals

Recently, it has been argued that obesity leads to a chronic pro-inflammatory state that can accelerate immunosenescence, predisposing to the early acquisition of an immune risk profile and health problems related to immunity in adulthood. In this sense, the present study aimed to verify, in circulating leukocytes, the gene expression of markers related to early immunosenescence associated with obesity and its possible relationships with the physical fitness in obese adults with type 2 diabetes or without associated comorbidities. The sample consisted of middle-aged obese individuals (body mass index (BMI) between 30-35 kg/m²) with type 2 diabetes mellitus (OBD; n = 17) or without associated comorbidity (OB; n = 18), and a control group of eutrophic healthy individuals (BMI: 20 - 25 kg/m²) of same ages (E; n = 18). All groups (OBD, OB and E) performed the functional analyses [muscle strength (1RM) and cardiorespiratory fitness (VO_2max)], anthropometry, body composition (Air Displacement Plethysmograph), blood collections for biochemical (anti-CMV) and molecular (gene expression of leptin, IL-2, IL-4, IL-6, IL-10, TNF-α, PD-1, P16^ink4a, CCR7, CD28 and CD27) analyses of markers related to immunosenescence. Increased gene expression of leptin, IL-2, IL-4, IL-10, TNF-α, PD-1, P16^ink4a, CCR7 and CD27 was found for the OBD and OB groups compared to the E group. Moreover, VO_2max for the OBD and OB groups was significantly lower compared to E. In conclusion, obesity, regardless of associated disease, induces increased gene expression of markers associated with inflammation and immunosenescence in circulating leukocytes in obese middle-aged individuals compared to a eutrophic group of the same age. Additionally, increased adipose tissue and markers of chronic inflammation and immunosenescence were associated to impairments in the cardiorespiratory capacity of obese middle-aged individuals.

UTP14A, DKC1, DDX10, PinX1, and ESF1 Modulate Cardiac Angiogenesis Leading to Obesity-Induced Cardiac Injury

BACKGROUND

This study is aimed at exploring the key genes and the possible mechanism of heart damage caused by obesity.

METHODS

We analyzed the GSE98226 dataset. Firstly, differentially expressed genes (DEGs) were identified in heart tissues of obese and normal mice. Then, we analyzed DEGs using Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis. Thirdly, we constructed a protein-protein interaction (PPI) network and key modules and searched hub genes. Finally, we observed the pathological changes associated with obesity through histopathology.

RESULTS

A total of 763 DEGs were discovered, including 629 upregulated and 134 downregulated genes. GO enrichment analysis showed that these DEGs were mainly related to the regulation of transcription, DNA-templated, nucleic acid binding, and metal ion binding. KEGG pathway analysis revealed that the DEGs were enriched in long-term depression, gap junction, and sphingolipid signaling pathways. Finally, we identified UTP14A, DKC1, DDX10, PinX1, and ESF1 as the hub genes. Histopathologic analysis showed that obesity increased the number of collagen fibers and decreased the number of microvessels and proliferation of the endothelium and increased endothelial cell damage which further leads to dysfunction of cardiac microcirculation.

CONCLUSION

UTP14A, DKC1, DDX10, PinX1, and ESF1 have been identified as hub genes in obesity-induced pathological changes in the heart and may be involved in obesity-induced cardiac injury by affecting cardiac microcirculatory function.

Immune cells in cardiac homeostasis and disease: emerging insights from novel technologies

The increasing use of single-cell immune profiling and advanced microscopic imaging technologies has deepened our understanding of the cardiac immune system, confirming that the heart contains a broad repertoire of innate and adaptive immune cells. Leucocytes found in the healthy heart participate in essential functions to preserve cardiac homeostasis, not only by defending against pathogens but also by maintaining normal organ function. In pathophysiological conditions, cardiac inflammation is implicated in healing responses after ischaemic or non-ischaemic cardiac injury. The aim of this review is to provide a concise overview of novel methodological advancements to the non-expert readership and summarize novel findings on immune cell heterogeneity and functions in cardiac disease with a focus on myocardial infarction as a prototypic example. In addition, we will briefly discuss how biological sex modulate the cardiac immune response. Finally, we will highlight emerging concepts for novel therapeutic applications, such as targeting immunometabolism and nanomedicine.