Do Changes in Innate Immunity Underlie the Cardiovascular Benefits of Exercise?

Low-intensity exercise training increases systolic function of heart and MHCII low cardiac resident macrophages

Physical activities have beneficial effects on cardiovascular health, although the specific mechanisms are largely unknown. Cardiac resident macrophages (cMacs) and the distribution of their subsets are critical regulators for maintaining cardiovascular health and cardiac functions in both steady and inflammatory states. Therefore, we investigated the subsets of cMacs in mice after low-intensity exercise training to elucidate the exercise-induced dynamic changes of cMacs and the benefits of exercise for the heart. The mice were subjected to treadmill running exercise five days per week for five weeks using a low-intensity exercise training protocol. Low-intensity exercise training resulted in a suppression of body weight gain in mice and a significant increase in the ejection fraction, a parameter that represents the systolic function of the heart. Low-intensity exercise training induced the alterations in the transcriptome of the heart, which are associated with muscle contraction and mitochondrial function. Furthermore, low-intensity exercise training did not alter the number of lymphocyte antigen 6 complex, locus C1 (Ly6c)- cMacs but instead remodeled the distributions of Ly6c- cMac subsets. We observed an increase in the percentage of major histocompatibility complex class II (MHCII)low cMacs and a decrease in the percentage of MHCIIhigh cMacs in the heart after low-intensity exercise training. Therefore, the benefits of exercise for cardiovascular fitness might be associated with the redistribution of cMac subsets and the enhancement of the ejection fraction.

Beyond cardiomyocytes: Cellular diversity in the heart's response to exercise

Cardiomyocytes comprise ∼70% to 85% of the total volume of the adult mammalian heart but only about 25% to 35% of its total number of cells. Advances in single cell and single nuclei RNA sequencing have greatly facilitated investigation into and increased appreciation of the potential functions of non-cardiomyocytes in the heart. While much of this work has focused on the relationship between non-cardiomyocytes, disease, and the heart's response to pathological stress, it will also be important to understand the roles that these cells play in the healthy heart, cardiac homeostasis, and the response to physiological stress such as exercise. The present review summarizes recent research highlighting dynamic changes in non-cardiomyocytes in response to the physiological stress of exercise. Of particular interest are changes in fibrotic pathways, the cardiac vasculature, and immune or inflammatory cells. In many instances, limited data are available about how specific lineages change in response to exercise or whether the changes observed are functionally important, underscoring the need for further research.

OxInflammation at High Altitudes: A Proof of Concept from the Himalayas

High-altitude locations are fascinating for investigating biological and physiological responses in humans. In this work, we studied the high-altitude response in the plasma and urine of six healthy adult trekkers, who participated in a trek in Nepal that covered 300 km in 19 days along a route in the Kanchenjunga Mountain and up to a maximum altitude of 5140 m. Post-trek results showed an unbalance in redox status, with an upregulation of ROS (+19%), NOx (+28%), neopterin (+50%), and pro-inflammatory prostanoids, such as PGE₂ (+120%) and 15-deoxy-delta12,14-PGJ₂ (+233%). The isoprostane 15-F_2t-IsoP was associated with low levels of TAC (−18%), amino-thiols, omega-3 PUFAs, and anti-inflammatory CYP450 EPA-derived mediators, such as DiHETEs. The deterioration of antioxidant systems paves the way to the overload of redox and inflammative markers, as triggered by the combined physical and hypoxic stressors. Our data underline the link between oxidative stress and inflammation, which is related to the concept of OxInflammation into the altitude hypoxia fashion.

Omega-3 polyunsaturated fatty acids modify the inverse association between systemic inflammation and cardiovascular fitness

BACKGROUND AND OBJECTIVE

Exercise increases quality of life and lowers all-cause mortality, likely by preventing cardiovascular disease. Although the beneficial effects of exercise are linked with reductions in chronic inflammation, individual responses vary and factors that contribute to the anti-inflammatory effects of cardiovascular fitness remain largely undefined. We sought to investigate the role of fatty acids in the inverse relationship between inflammation and cardiovascular fitness.

APPROACH AND RESULTS

In this cross-sectional study using data from 435 participants in NHANES and linear regression models with CRP as the outcome, we observed significant negative interactions between VO₂max and omega-3 polyunsaturated fatty acids (PUFAs) but not saturated, monounsaturated, or omega-6 PUFAs. When stratified by omega-3 PUFA tertiles, participants in the medium tertile, but not low tertile, show an enhanced negative association between VO₂max and CRP, with a -32.0% difference (95% CI: -44.95, -15.9%) per 10 mL/kg/min of VO₂max. Exploratory factor analysis identified five unique dietary fatty acid (FA) profiles. The FA profile consisting predominantly of omega-3 PUFA had the strongest negative association for VO₂max and CRP, with a -28.2% difference in CRP (95% CI: -43.4, -8.9) per 10 mL/kg/min of VO₂max. We also found that alpha-linolenic acid (ALA) and docosahexaenoic acid (DHA) enhanced the negative association between VO₂max and CRP, suggesting that the anti-inflammatory response to VO₂max capacity is associated with ALA and DHA levels. Males, Whites, and individuals with lower BMI were more sensitive to the effects of omega-3 PUFAs, while having high SFA levels attenuated the benefit.

CONCLUSIONS

This study suggests that omega-3 PUFAs are effect modifiers for VO₂max and CRP and that the anti-inflammatory benefits of increasing cardiovascular fitness are associated with omega-3 PUFAs.

Antihypertensive Pharmacotherapy in Correcting the Indicators of Innate Immunity in Patients with Essential Arterial Hypertension

Introduction: The study of indicators of innate immunity in patients with arterial hypertension in clinical trials makes it necessary to correct them in order to reduce vascular inflammation in arterial hypertension to prevent damage to target organs and development of cardiovascular complications. The aim of the study was to assess the effectiveness of antihypertensive therapy to correct indicators of innate immunity in patients with essential arterial hypertension.

Materials and methods: Patients with essential arterial hypertension (EAH) (II stage, 3rd degree) were divided into 3 groups: the 1st group included the patients with hypertrophy of the left ventricular myocardium; the 2nd group included the patients with atherosclerotic vascular lesions; the 3rd group included the patients with chronic kidney disease. As an initial antihypertensive pharmacotherapy, all the patients with essential arterial hypertension were prescribed perindopril (5–10 mg/day) and amlodipine (5–10 mg/day).

Results and discussion: Changes in innate immunity indices in patients with essential arterial hypertension (II stage, 3rd degree) are differentiated depending on the affected target organ. The antihypertensive pharmacotherapy with perindopril and amlodipine in patients with essential arterial hypertension has various corrective effects on impaired innate immunity, depending on the nature of target organ damage. Regardless of target organ damage, ноу antihypertensive therapy with perindopril and amlodipine does not affect the reduced functional and increased metabolic activities of peripheral blood neutrophils.

Conclusion: The results obtained dictate the need for further clinical studies of other classes of antihypertensive drugs and their combinations in the correction of innate immunity indices in order to effectively prevent the progression of target organ damage.

Graphical abstract

Space Flight Diet-Induced Deficiency and Response to Gravity-Free Resistive Exercise

Immune system dysregulation is among the many adverse effects incurred by astronauts during space flights. Omega-3 fatty acids, β-alanine, and carnosine are among the many nutrients that contribute to immune system health. For space flight, crewmembers are prescribed a diet with a macronutrient composition of 55% carbohydrate, 30% fat, and 15% protein. To quantify omega-3 fatty acid, β-alanine and carnosine intakes from such a diet, and to examine each nutrient's impact on exercise performance, 21 participants adhered to the aforementioned macronutrient ratio for 14 days which was immediately followed by a workout performed on gravity-independent resistive exercise hardware. Results included daily omega-3 fatty acid intakes below the suggested dietary intake. Daily omega-3 fatty acid, β-alanine and carnosine intakes each correlated with non-significant amounts of variance from the workout's volume of work. Given the nutritional requirements to maintain immune system function and the demands of in-flight exercise countermeasures for missions of increasingly longer durations current results, in combination with previously published works, imply in-flight supplementation may be a prudent approach to help address the physiological and mental challenges incurred by astronauts on future space flights.

Treatment of Obesity in Mitigating Metabolic Risk

Through diverse mechanisms, obesity contributes to worsened cardiometabolic health and increases rates of cardiovascular events. Effective treatment of obesity is necessary to reduce the associated burdens of diabetes mellitus, cardiovascular disease, and death. Despite increasing cardiovascular outcome data on obesity interventions, only a small fraction of the population with obesity are optimally treated. This is a primary impetus for this article in which we describe the typical weight loss, as well as the associated impact on both traditional and novel cardiovascular disease risk factors, provided by the 4 primary modalities for obtaining weight loss in obesity-dietary modification, increasing physical activity, pharmacotherapy, and surgery. We also attempt to highlight instances where changes in metabolic risk are relatively specific to particular interventions and appear at least somewhat independent of weight loss. Finally, we suggest important areas for further research to reduce and prevent adverse cardiovascular consequences due to obesity.