Monocyte Subsets in Atherosclerosis and Modification with Exercise in Humans

Abstract

Atherosclerosis is a progressive pathological remodeling of the arteries and one of its hallmarks is the presence of chronic inflammation. Notably, there is an increased proportion and activation state of specific monocyte subsets in systemic blood circulation. Monocyte subsets have distinct contributions to the formation, progression, and destabilization of the atherosclerotic plaque. Strong clinical and epidemiological studies show that regular aerobic exercise mitigates the progression of cardiovascular disease. In fact, aerobic fitness is a powerful predictor of cardiovascular mortality in adults, independent of traditional risk factors such as hypertension and hyperlipidemia. Acute bouts and chronic exercise training modulate monocyte behavior, ranging from their recruitment from the bone marrow or marginal pool, to tissue margination and functional changes in cytokine and chemokine production. Such modulation could reflect a potential mechanism for the cardio-protective effect of exercise on atherosclerosis. This review summarizes the current knowledge of monocyte subsets and highlights what is known about their responses to exercise.

Chronic Inflammation as an Immunological Abnormality and Effectiveness of Exercise

“…The anti-inflammatory effects of exercise are becoming better understood at being effective for preventing chronic inflammation. Candidate biomarkers are used to reveal the effects of exercise from a pathological point of view or to develop early prognostic markers [48,49,50,96,97,98,99]. However, further prevention of chronic diseases, improvements in quality of life, and an extension of healthy life expectancy by implementing not only exercise but also dietary supplementation and favorable lifestyle factors are anticipated to become more actively promoted in the future [100,101].…”

“…A study has shown that approximately 100 min of walking exercise per week for three months in elderly people without prior exercise habits resulted in decreased markers of neutrophil activation and oxidative stress [48]. Apart from the effects on neutrophils, various exercise-induced anti-inflammatory effects on the innate immune system have been uncovered: for example, changes in M1/M2 macrophages in fat tissue due to exercise training [25] or arteriosclerosis and changes in blood monocyte subsets [49]. These studies will potentially expand from preventive medicine to preemptive medicine to reveal the effects of exercise from a pathological mechanism point of view or to develop early prognostic markers.…”

“…Exercise can increase energy consumption, while preventing or improving obesity, diabetes, dyslipidemia, and hypertension [12,19,57]. Exercise is also effective in preventing atherosclerotic diseases such as ischemic heart disease or cerebrovascular disease and cancer [10,49,58]. Exercise not only affects metabolism and the cardiovascular system but also supports the maintenance/enhancement of locomotive organs.…”

Evaluation of Anti-Inflammatory and Atheroprotective Properties of Wheat Gluten Protein Hydrolysates in Primary Human Monocytes

“…A feature of atherosclerosis is chronic inflammation and increased activation of monocytes in the systemic blood circulation. Monocytes are cells with a myeloid origin, which are actively engaged in systemic and chronic inflammation and have distinct contributions to the formation, progression, and destabilization of the atherosclerotic plaque [15]. The metabolism of monocytes can be reprogrammed in the atherogenic microenvironments, which consist of hypoxia, molecular damage, and modified lipoproteins [16].…”

Exercise and Inflammation

“…These reviews are complimented by overviews of the influences of specific and more general dietary factors, such as β-hydroxy-β-methylbutyrate (HMB) by Arazi and colleagues [16], and antioxidant intake by Kawamura and Muraoka [17]. Finally, perspectives relating to the pathophysiological conditions of atherosclerosis [18] and heat stroke [19] are provided. Empirical studies include an in vitro model of muscle cell damage [20], the investigation of nutrient supplementation such as alpha-lipoic acid [21], HMB [16], barley-wheat grass juice [22] and graded carbohydrate intake [23], and an investigation into the efficacy of post-exercise hydrogen baths [24].…”