Immune Cell Activation in Obesity and Cardiovascular Disease

Deciphering immune cell heterogeneity in vascular diseases: Insights from single-cell sequencing

The complexity and diversity of vascular diseases highlight the urgent need to study their pathogenesis, particularly the key role of immune cell-mediated inflammatory responses in their development. While previous reviews have outlined the involvement of immune cells in vascular pathology, a comprehensive understanding of their dynamic changes, functional states, and intercellular interactions remains incomplete. Recent advances in single-cell sequencing (SCS) have provided unprecedented insights into immune cell heterogeneity, enabling the identification of novel subpopulations and their roles in disease progression.This review extends prior work by systematically summarizing the latest applications of SCS in vascular diseases, highlighting newly discovered immune cell subsets, their interactions, and their impact on vascular pathology. By addressing current gaps in the literature-such as the functional plasticity of immune cells and their temporal dynamics-this review offers new perspectives on immune-mediated mechanisms in vascular diseases and proposes novel therapeutic strategies for their prevention and treatment.

Metabolic Homeostasis of Immune Cells Modulates Cardiovascular Diseases

Recent investigations into the mechanisms underlying inflammation have highlighted the pivotal role of immune cells in regulating cardiac pathophysiology. Notably, these immune cells modulate cardiac processes through alternations in intracellular metabolism, including glycolysis and oxidative phosphorylation, whereas the extracellular metabolic environment is changed during cardiovascular disease, influencing function of immune cells. This dynamic interaction between immune cells and their metabolic environment has given rise to the novel concept of "immune metabolism". Consequently, both the extracellular and intracellular metabolic environment modulate the equilibrium between anti- and pro-inflammatory responses. This regulatory mechanism subsequently influences the processes of myocardial ischemia, cardiac fibrosis, and cardiac remodeling, ultimately leading to a series of cardiovascular events. This review examines how local microenvironmental and systemic environmental changes induce metabolic reprogramming in immune cells and explores the subsequent effects of aberrant activation or polarization of immune cells in the progression of cardiovascular disease. Finally, we discuss potential therapeutic strategies targeting metabolism to counteract abnormal immune activation.

Diabetes mortality burden attributable to influenza in China: A population-based time-series analysis

Background

Previous studies have found an association between influenza, cardiovascular and cerebrovascular disease mortality, and all-cause mortality. And the vaccination of elderly diabetes is often recommended to reduce the risk of hospitalization and death. Nevertheless, no previous work has investigated the short-term impact of influenza on diabetes mortality in China. In this study, data from the national surveillance system was used to quantify the impact of influenza on diabetes-related mortality and provide guidance for the care of diabetes patients.

Methods

Data from the National Influenza Surveillance Center was collected for the period between 2015 and 2019 and weekly diabetes-related deaths were calculated from China's Disease Surveillance Points System (CDSP). A distributed non-linear lag model (DLNM) was used to 1] analyze the delayed impact of high influenza virus-positive rates on diabetes-related mortality, 2] calculate the relative risk of diabetes deaths caused by high influenza virus-positive rate, and 3] estimate the attributable risk of diabetes deaths caused by influenza in China.

Results

A total of 260 weeks of influenza weekly data from southern and northern China were included in this study. This resulted in 256,845 diabetes-related deaths with an average age of 73.36 years. During this period, the mean influenza virus-positive rate was 12.79 %. The relative risk of death from diabetes at high influenza positive rate was 1.33 (95 % CI [1.25, 1.40]) in southern China and 1.14 (95 % CI [1.08, 1.20]) in northern China for a 3-week lag. The estimated population attributable fraction (PAF) was 9.64 % (95 % CI [6.6 %, 12.55 %]) in southern China and 1.69 % (95 % CI [-0.04 %, 3.35 %]) in northern China. The present study suggest that reducing the influenza virus-positive rate to optimal levels could potentially prevent approximately 10,871 diabetes-related deaths annually.

Conclusion

A high influenza virus-positive rate is associated with an increased risk of diabetes-related mortality. Moreover, this effect is consistent across geographical areas and gender groups. Overall, the present study suggests that the risk of diabetes-related mortality attributable to influenza is high in China.

Effect of Whole-Body Electrical Muscle Stimulation Training on Inflammatory and Anti-inflammatory Cytokines in Overweight Men

BACKGROUND

The aim of this study was to investigate the effects of whole-body electrical muscle stimulation (WB-EMS) training on inflammatory and anti-inflammatory cytokines in overweight men.

METHODS

We divided 30 participants into EMS and control groups. The training program for the EMS group comprised 20 WB-EMS sessions (7 weeks, three sessions per week).

RESULTS

The results showed that EMS training caused significant increase in interferon γ (P<0.001) and interleukin 10 (IL-10; P<0.01) and significant decrease in IL-17 and IL-23 (P<0.05). Also, the lipid profile showed significant positive changes in the EMS training group.

CONCLUSION

EMS training, a novel exercise method that uses electric stimulation, can affect the levels of various cytokines that are involved in inflammation and immunity. EMS training can have both beneficial and harmful effects on the body depending on the type and balance of involved cytokines.

Hypertension in non-obese children and BMI in adulthood: the Bogalusa heart study

OBJECTIVE

This study explored the association between hypertension(HTN) in non-obese children body mass index (BMI) in adulthood.

METHODS

A retrospective analysis of 1111 participants from the Bogalusa Heart Study was conducted, in which data on hypertension history during childhood in non-obese children, anthropometric and cardiovascular risk factors and other indicators from cross-sectional examinations in adulthood were collected. BMI was used as both a continuous and a categorical variable, and multivariate linear regression modelling and logistic regression modelling were used.

RESULTS

Of the 1111 participants finally enrolled, 40 (3.60%) had HTN during childhood. After adjusting for demographic characteristics, lipid, glucose and insulin levels in childhood, and smoking status, alcohol intake, and disease history as adults, HTN among non-obese children was positively associated with BMI in adulthood (β = 2.64 kg/m2, 95% CI: 0.88-4.40, P = 0.0033), and the odds of being overweight or obese was 3.71 times higher in the group with a history of hypertension in childhood than those without a history of HTN(95% CI: 1.11-12.46, P = 0.0337).

CONCLUSION

Among non-obese children, hypertension is at risk for higher levels of BMI in adulthood. Identifying and controlling blood pressure and childhood may aid in the prevention of adult obesity.

Deletion of complement factor 5 amplifies glucose intolerance in obese male but not female mice

Complement factor 5 of the innate immune system generates C5a and C5b ligands, which initiate inflammatory and cell lysis events, respectively. C5 activation has been linked with obesity-associated metabolic disorders; however, whether it has a causative role is unclear. We generated a C5 null (C5-/-) mouse using CRISPR-Cas9 gene editing to determine whether loss of C5 improves obesity-linked metabolic dysfunction. Generation of a new mouse model was prompted in part by the observation of off-target gene mutations in commercially available C5-/- lines. Male and female wild-type (WT), heterozygous (Het), and C5-/- mice were fed low-fat diet (LFD) or high-fat diet (HFD) for 22 wk. Body weight gain did not differ between genotypes on LFD or HFD. In lean animals, male C5-/- mice had similar glucose tolerance compared with WT controls; however, in obese conditions, glucose tolerance was worsened in C5-/- compared with controls. In contrast, female mice did not exhibit differences in glucose tolerance between genotypes under either dietary paradigm. Fasting insulin was not different between genotypes, whereas diet-induced obese male C5-/- mice had lower fed insulin concentrations compared with WT controls. No differences in adipose tissue inflammation or adipocyte size were identified between groups. Similarly, susceptibility to fatty liver and hepatic inflammation was similar between WT and C5-/- mice. However, the systemic cytokine response to acute endotoxin exposure was decreased in C5-/- mice. Together, these data suggest that loss of C5 worsens glucose tolerance in obese male but not female mice. Additional work is required to pinpoint the mechanisms by which loss of C5 amplifies glucose intolerance in obesity.NEW & NOTEWORTHY We generated a new mouse model of complement factor 5 deficiency. This work was prompted by a need for improved transgenic mouse lines of C5, due to off-target gene mutations. We find that loss of C5 worsens glucose tolerance in a sex-dependent manner. Though the mechanisms evoking glucose intolerance are not clear, we are confident this model will be useful in interrogating complement activation in obesity-associated diseases.

Hypertensive heart disease: risk factors, complications and mechanisms

Hypertensive heart disease constitutes functional and structural dysfunction and pathogenesis occurring primarily in the left ventricle, the left atrium and the coronary arteries due to chronic uncontrolled hypertension. Hypertensive heart disease is underreported and the mechanisms underlying its correlates and complications are not well elaborated. In this review, we summarize the current understanding of hypertensive heart disease, we discuss in detail the mechanisms associated with development and complications of hypertensive heart disease especially left ventricular hypertrophy, atrial fibrillation, heart failure and coronary artery disease. We also briefly highlight the role of dietary salt, immunity and genetic predisposition in hypertensive heart disease pathogenesis.

Obesity and dysregulated innate immune responses: impact of micronutrient deficiencies

Obesity is associated with the development of various complications, including diabetes, atherosclerosis, and an increased risk for infections, driven by dysfunctional innate immune responses. Recent insights have revealed that the availability of nutrients is a key determinant of innate immune cell function. Although the presence of obesity is associated with overnutrition of macronutrients, several micronutrient deficiencies, including Vitamin D and zinc, are often present. Micronutrients have been attributed important immunomodulatory roles. In this review, we summarize current knowledge of the immunomodulatory effects of Vitamin D and zinc. We also suggest future lines of research to further improve our understanding of these micronutrients; this may serve as a stepping-stone to explore micronutrient supplementation to improve innate immune cell function during obesity.

Quo Vadis? Immunodynamics of Myeloid Cells after Myocardial Infarction

Myocardial infarction (MI), a major contributor to worldwide morbidity and mortality, is caused by a lack of blood flow to the heart. Affected heart tissue becomes ischemic due to deficiency of blood perfusion and oxygen delivery. In case sufficient blood flow cannot be timely restored, cardiac injury with necrosis occurs. The ischemic/necrotic area induces a systemic inflammatory response and hundreds of thousands of leukocytes are recruited from the blood to the injured heart. The blood pool of leukocytes is rapidly depleted and urgent re-supply of these cells is needed. Myeloid cells are generated in the bone marrow (BM) and spleen, released into the blood, travel to sites of need, extravasate and accumulate inside tissues to accomplish various functions. In this review we focus on the "leukocyte supply chain" and will separately evaluate different myeloid cell compartments (BM, spleen, blood, heart) in steady state and after MI. Moreover, we highlight the local and systemic kinetics of extracellular factors, chemokines and danger signals involved in the regulation of production/generation, release, transportation, uptake, and activation of myeloid cells during the inflammatory phase of MI.