Papadopoulos, G. | Search bioRxiv

bioRxiv2025

Exercise induces anti-inflammatory reprogramming in macrophages via Hsp60

Physical activity exerts systemic anti-inflammatory effects and reduces the risk for multiple non-communicable diseases, with 7.2% of all-cause deaths globally being attributed to physical inactivity. However, the cellular and molecular components of the exercise-induced anti-inflammatory effects remain only partly understood. Herein we show that moderate-intensity exercise promotes anti-inflammatory reprograming of macrophages orchestrated by the skeletal muscle cells secretome. Primary bone marrow-derived macrophages (BMDMs) exposed to the secretome of mechanically-loaded myotubes (exercise-conditioned medium, exCM) acquire an anti-inflammatory transcriptional profile and increased reliance on oxidative phosphorylation, as shown by Seahorse real-time cell metabolic analysis, compatible with an M2-like phenotypic switch. Using an unbiased proteomic analysis of the exCM we identify the chaperonin Hsp60 as a key mediator of the anti-inflammatory effects of exercise. Hsp60 expression increases in mechanically loaded myotubes in vitro, in the quadriceps muscle and serum of mice following an 8-week program of moderate-intensity aerobic exercise, as well as in human muscle after resistance training. Importantly, treatment of BMDMs with Hsp60 in vitro recapitulates the exCM-induced transcriptional reprograming, promoting an M2-like phenotype. Taken together, our data highlight Hsp60 as a novel component of the skeletal muscle cell-macrophage crosstalk, providing mechanistic insights into the anti-inflammatory effects of exercise.

physiology↗

bioRxiv2024

Exercise alleviates liver senescence but does not outmatch the effect of dietary restriction in diet-induced MASLD

BackgroundThe present study aims at deciphering the potential benefits of aerobic exercise and dietary restriction on liver senescence, which is an established hallmark of metabolic dysfunction-associated steatotic liver disease (MASLD), a condition with limited therapeutic options. MethodsC57BL6 mice were subjected to normal diet (ND, 10% of kilocalories from fat) or a high-fat diet (HFD, 60% of kilocalories deriving from fat and water supplemented with 5% High-fructose Corn Syrup, HFCS) for 12 weeks. Then, for additional 8 weeks, the ND group continued with the same diet, while the HFD group was divided into four subgroups: a) mice that continued with the same HFD-5% HFCS in water scheme (HFD), b) mice that continued with the same HFD-5% HFCS in water scheme and underwent supervised aerobic exercise 3-times/week (HFDEX), c) mice that were switched to ND (dietary restriction, DR) and d) mice that were switched to ND while undergoing supervised aerobic exercise 3-times/week (DREX). Phenotypic and histological characterization of obesity and MASLD were performed in all groups. Biomarkers of senescence were analyzed in terms of their mRNA expression levels to assess the impact of all interventions on MASLD-related senescence in the liver. GL13 and p21 immunohistochemical stainings were conducted to examine the protein levels of senescence-associated lipofuscin and p21WAF1/CIP1 respectively, so as to finally investigate their relationship with the grade of steatosis observed in each individual animal. ResultsDR and DREX groups exhibited significantly reduced features of obesity and MASLD-related hepatic steatosis, to a greater extent than the respective amelioration driven by aerobic exercise-only in HFDEX animals. A statistically significant increase of the mRNA expression of cyclin-dependent kinase p21WAF1/CIP1 was detected in HFD livers as compared to ND, which was also reversed upon DR-inclusive interventions. In contrast, the gene expression levels of cyclin-dependent kinase p16INK4a remained similar in all groups even after a combined intervention. Increased hepatic expression of the p27 and p53 components of the p53-p21 CIP/WAF-driven axis of cellular senescence as well as their restoration to ND-like levels upon DR and DREX, suggest an active participation of the p21WAF1/CIP1 mechanism of senescence in the emergence of MASLD, but also in its reversal through DR or/and EX interventions. Immunohistochemical stainings for GL13 and p21 confirmed the aforementioned alterations of p21WAF1/CIP1 at the tissular level. ConclusionLiver senescence is responsive both to exercise and dietary restriction, but its amelioration in the context of MASLD is more robust upon DR-inclusive interventions.

physiology↗