IntroductionOur aim was to evaluate the safety and efficacy of a low-intensity resistance training program combined with partial blow flow restriction (BFR training) in a cohort of patients with polymyositis (PM) and dermatomyositis (DM).MethodsIn total, 13 patients with PM and DM completed a 12-week twice a week low-intensity (that is, 30% one-repetition-maximum (1RM)) resistance exercise training program combined with partial blood flow restriction (BFR). Assessments of muscle strength, physical function, quadriceps cross sectional (CSA) area, health-related quality of life, and clinical and laboratory parameters were assessed at baseline and after the intervention.ResultsThe BFR training program was effective in increasing the maximal dynamic strength in both the leg-press (19.6%, P <0.001) and knee-extension exercises (25.2% P <0.001), as well as in the timed-stands (15.1%, P <0.001) and timed-up-and-go test (−4.5%, P =0.002). Quadriceps CSA was also significantly increased after the intervention (4.57%, P =0.01). Similarly, all of the components of the Short Form-36 Health Survey, the Health Assessment Questionnaire scores, and the patient- and physician reported Visual Analogue Scale were significantly improved after training (P <0.05). Importantly, no clinical evidence or any other self-reported adverse event were found. Laboratory parameters (creatine kinase and aldolase) were also unchanged (P >0.05) after the intervention.ConclusionsWe demonstrated that a 12-week supervised low-intensity resistance training program associated with partial blood flow restriction may be safe and effective in improving muscle strength and function as well as muscle mass and health-related quality of life in patients with PM and DM.Trial registrationClinicaltrials.gov NCT01501019. Registered November 29, 2011.

Aging impairs tissue repair. This is pronounced in skeletal muscle, whose regeneration by muscle stem cells (MuSCs) is robust in young adult animals but inefficient in older organisms. Despite this functional decline, old MuSCs are amenable to rejuvenation through strategies that improve the systemic milieu, such as heterochronic parabiosis. One such strategy, exercise, has long been appreciated for its benefits on healthspan, but its effects on aged stem cell function in the context of tissue regeneration are incompletely understood. Here we show that exercise in the form of voluntary wheel running accelerates muscle repair in old animals and improves old MuSC Reprints and permissions information is available at http://www.nature.com/reprints.

Chronic inflammation impairs skeletal muscle regeneration. Although many cells are involved in chronic inflammation, macrophages seem to play an important role in impaired muscle regeneration since these cells are associated with skeletal muscle stem cell (namely, satellite cells) activation and fibro-adipogenic progenitor cell (FAP) survival. Specifically, an imbalance of M1 and M2 macrophages seems to lead to impaired satellite cell activation, and these are the main cells that function during skeletal muscle regeneration, after muscle damage. Additionally, this imbalance leads to the accumulation of FAPs in skeletal muscle, with aberrant production of pro-fibrotic factors (e.g., extracellular matrix components), impairing the niche for proper satellite cell activation and differentiation. Treatments aiming to block the inflammatory pro-fibrotic response are partially effective due to their side effects. Therefore, strategies reverting chronic inflammation into a pro-regenerative pattern are required. In this review, we first describe skeletal muscle resident macrophage ontogeny and homeostasis, and explain how macrophages are replenished after muscle injury. We next discuss the potential role of chronic physical activity and exercise in restoring the M1 and M2 macrophage balance and consequently, the satellite cell niche to improve skeletal muscle regeneration after injury.

IntroductionWe aimed to gather knowledge on the cardiac autonomic modulation in patients with fibromyalgia (FM) in response to exercise and to investigate whether this population suffers from chronotropic incompetence (CI).MethodsFourteen women with FM (age: 46 ± 3 years; body mass index (BMI): 26.6 ± 1.4 kg/m2) and 14 gender-, BMI- (25.4 ± 1.3 kg/m2), and age-matched (age: 41 ± 4 years) healthy individuals (CTRL) took part in this cross-sectional study. A treadmill cardiorespiratory test was performed and heart-rate (HR) response during exercise was evaluated by the chronotropic reserve. HR recovery (deltaHRR) was defined as the difference between HR at peak exercise and at both first (deltaHRR1) and second (deltaHRR2) minutes after the exercise test.ResultsFM patients presented lower maximal oxygen consumption (VO2 max) when compared with healthy subjects (22 ± 1 versus CTRL: 32 ± 2 mL/kg/minute, respectively; P < 0.001). Additionally, FM patients presented lower chronotropic reserve (72.5 ± 5 versus CTRL: 106.1 ± 6, P < 0.001), deltaHRR1 (24.5 ± 3 versus CTRL: 32.6 ± 2, P = 0.059) and deltaHRR2 (34.3 ± 4 versus CTRL: 50.8 ± 3, P = 0.002) than their healthy peers. The prevalence of CI was 57.1% among patients with FM.ConclusionsPatients with FM who undertook a graded exercise test may present CI and delayed HR recovery, both being indicative of cardiac autonomic impairment and higher risk of cardiovascular events and mortality.

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Acute kidney injury (AKI) is considered an inflammatory disease in which toll-like receptors (TLRs) signaling pathways play an important role. The activation of TLRs results in production of several inflammatory cytokines leading to further renal damage. In contrast, TLRs are key players on autophagy induction, which is associated with a protective function on cisplatin-induced AKI. Hence, the present study aimed to evaluate the specific participation of TLR2 and TLR4 molecules on the development of cisplatin-induced AKI. Complementarily, we also investigated the link between TLRs and heme oxygenase-1 (HO-1), a promisor cytoprotective molecule. First, we observed that only the absence of TLR2 but not TLR4 in mice exacerbated the renal dysfunction, tissue injury and mortality rate, even under an immunologically privileged microenvironment. Second, we demonstrated that TLR2 knockout (KO) mice presented lower expression of autophagy-associated markers when compared with TLR4 KO animals. Similar parameter was confirmed , using tubular epithelial cells derived from both KO mice. To test the cross-talking between HO-1 and TLRs, hemin (an HO-1 internal inducer) was administrated in cisplatin-treated TLR2 and TLR4 KO mice and it was detected an improvement in the global renal tissue parameters. However, this protection was less evident at TLR2 KO mice. In summary, we documented that TLR2 plays a protective role in cisplatin-induced AKI progression, in part, by a mechanism associated with autophagy up-regulation, considering that its interplay with HO-1 can promote renal tissue recover.

Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by chronic inflammation. This study sought to assess the effects of an exercise training program on cytokines and soluble TNF receptors (sTNFRs) in response to acute exercise in SLE women. Eight SLE women and 10 sex-, age-, and body mass index-comparable healthy controls (HC) participated in this study. Before and after a 12-wk aerobic exercise training program, cytokines and sTNFRs were assessed at rest and in response to single bouts of acute moderate/intense exercise. HC performed the acute exercise bouts only at baseline. After the exercise training program, there was a decrease in resting TNFR2 levels (P = 0.025) and a tend to reduction interleukin (IL)-10 levels (P = 0.093) in SLE. The resting levels of IL-6, IL-10, and TNF-α after the exercise training in SLE reached HC levels (P > 0.05). In response to a single bout of acute moderate exercise, the area under the curve (AUC) of IL-10 was significantly reduced after the exercise training program in SLE (P = 0.043), and the AUC of IL-10, IL-6, TNF-α, and sTNFR1 of SLE approached control values (P > 0.05). In response to a single bout of acute intense exercise, the AUC of IL-10 was significantly reduced in SLE (P = 0.015). Furthermore, the AUC of sTNFR2 tended to decrease after exercise training program in SLE (P = 0.084), but it did not reach control values (P = 0.001). An aerobic exercise training program attenuated the inflammatory milieu in SLE women, revealing a novel homeostatic immunomodulatory role of exercise in an autoimmunity condition.

Objective. To evaluate the efficacy of a 3-month exercise training program in counteracting the chronotropic incompetence and delayed heart rate recovery in patients with systemic lupus erythematosus (SLE). Methods. A 12-week randomized trial was conducted. Twenty-four inactive SLE patients were randomly assigned into 2 groups: trained (T; n ‫؍‬ 15, 3-month exercise program) and nontrained (NT; n ‫؍‬ 13). A sex-, body mass index-, and age-matched healthy control (C) group (n ‫؍‬ 8) also underwent the exercise program. Subjects were assessed at baseline and at 12 weeks after training. Main measurements included the chronotropic reserve (CR) and the heart rate (HR) recovery (⌬HRR) as defined by the difference between HR at peak exercise and at both the first (⌬HRR1) and second (⌬HRR2) minutes after the exercise test. Results. Neither the NT SLE patients nor the C group presented any change in the CR or in ⌬HRR1 and ⌬HRR2 (P > 0.05). The exercise training program was effective in promoting significant increases in CR (P ‫؍‬ 0.007, effect size [ES] 1.15) and in ⌬HRR1 and ⌬HRR2 (P ‫؍‬ 0.009, ES 1.12 and P ‫؍‬ 0.002, ES 1.11, respectively) in the SLE T group when compared with the NT group. Moreover, the HR response in SLE patients after training achieved parameters comparable to the C group, as evidenced by the analysis of variance and by the Z score analysis (P > 0.05, T versus C). Systemic Lupus Erythematosus Disease Activity Index scores remained stable throughout the study. Conclusion. A 3-month exercise training program was safe and capable of reducing the chronotropic incompetence and the delayed ⌬HRR observed in physically inactive SLE patients.