Effects of aging and lifelong aerobic exercise on basal and exercise-induced inflammation

Abstract

Age-associated chronic basal inflammation compromises muscle mass and adaptability, but exercise training may exert an anti-inflammatory effect. This investigation assessed basal and exercise-induced inflammation in three cohorts of men: young exercisers [YE; n = 10 men; 25 ± 1 yr; maximal oxygen consumption (V̇o2max), 53 ± 3 mL·kg−1·min−1; quadriceps area, 78 ± 3 cm2; means ± SE], old healthy nonexercisers (OH; n = 10; 75 ± 1 yr; V̇o2max, 22 ± 1 mL·kg−1·min−1; quadriceps area, 56 ± 3 cm2), and lifelong exercisers with an aerobic training history of 53 ± 1 yr (LLE; n = 21; 74 ± 1 yr; V̇o2max, 34 ± 1 mL·kg−1·min−1; quadriceps area, 67 ± 2 cm2). Resting serum IL-6, TNF-α, C-reactive protein, and IGF-1 levels were measured. Vastus lateralis muscle biopsies were obtained at rest (basal) and 4 h after an acute exercise challenge (3 × 10 repetitions, 70% 1-repetition maximum) to assess gene expression of cytokines [IL-6, TNF-α, IL-1β, IL-10, IL-4, interleukin-1 receptor antagonist (IL-1Ra), and transforming growth factor-β (TGF-β)], chemokines [IL-8 and monocyte chemoattractant protein-1 (MCP-1)], cyclooxygenase enzymes [cyclooxygenase-1 and -2 (COX-1 and COX-2, respectively), prostaglandin E2 synthases [microsomal prostaglandin E synthase 1 (mPGES-1) and cytosolic prostaglandin E2 synthase (cPGES)] and receptors [prostaglandin E2 receptor EP3 and EP4 subtypes (EP3 and EP4, respectively), and macrophage markers [cluster of differentiation 16b (CD16b) and CD163], as well as basal macrophage abundance (CD68+ cells). Aging led to higher ( P ≤ 0.05) circulating IL-6 and skeletal muscle COX-1, mPGES-1, and CD163 expression. However, LLE had significantly lower serum IL-6 levels ( P ≤ 0.05 vs. OH) and a predominantly anti-inflammatory muscle profile [higher IL-10 ( P ≤ 0.05 vs. YE), TNF-α, TGF-β, and EP4 levels ( P ≤ 0.05 vs. OH)]. In OH only, acute exercise increased expression of proinflammatory factors TNF-α, TGF-β, and IL-8 ( P ≤ 0.05). LLE had postexercise gene expression similar to YE, except lower IL-10 ( P ≤ 0.10), mPGES-1, and EP3 expression ( P ≤ 0.05). Thus, although aging led to a proinflammatory profile within blood and muscle, lifelong exercise partially prevented this and generally preserved the acute inflammatory response to exercise seen in young exercising men. Lifelong exercise may positively impact muscle health throughout aging by promoting anti-inflammation in skeletal muscle. NEW & NOTEWORTHY This study assessed a unique population of lifelong aerobic exercising men and demonstrated that their activity status exerts an anti-inflammatory effect in skeletal muscle and circulation. Furthermore, we provide evidence that the inflammatory response to acute exercise is dysregulated by aging but preserved with lifelong exercise, which might improve skeletal muscle resilience to unaccustomed loading and adaptability into late life.

Interactions between Muscle and Bone—Where Physics Meets Biology

“…More in-depth functional characterization is necessary to unravel all the protein functions of putatively muscle and bone coupling genes, especially those that have so far not yet been linked to muscle and bone interaction. While this work addresses the difference between untrained versus endurance or resistance-trained healthy subjects, we have to keep in mind that the response of young versus old or healthy versus diseased exercisers may as well be fundamentally different, as it was very recently reported [95]. Table 1.…”

International Union of Basic and Clinical Pharmacology. CIX. Differences and Similarities between Human and Rodent Prostaglandin E2Receptors (EP1–4) and Prostacyclin Receptor (IP): Specific Roles in Pathophysiologic Conditions

“…In human, EP3 and EP4 receptors are expressed in skeletal muscle biopsies of the thigh ( vastus lateralis ), and mostly EP4 expression is associated to anti-inflammation profile in muscle and linked to exercise training ( Lavin et al, 2020 ). These receptors are also described and are more expressed in human skeletal muscle of the leg containing mostly type-1 fibers ( soleus ) ( Liu et al, 2016 ).…”

Docosahexaenoic Acid, a Potential Treatment for Sarcopenia, Modulates the Ubiquitin–Proteasome and the Autophagy–Lysosome Systems

“…In healthy subjects, there is a clear correlation between the protein synthesis rate and the levels of growth hormones, such as insulin-like growth factor-I (IGF-I) in skeletal muscle [40,41] (Figure 1). In aged muscle, low levels of IGF-I are often accompanied by a high expression of muscle growth inhibitors, including the pro-inflammatory cytokines tumor necrosis factor α and interleukin 6 [42,43]. IGF-I downregulation is also closely associated with enhanced myostatin levels [44][45][46] and reduced DNA/protein synthesis [47].…”