Moderate Treadmill Training Induces Limited Effects on Quadriceps Muscle Hypertrophy in Mice Exposed to Cigarette Smoke Involving Metalloproteinase 2

Author(s)

Ramos, Gracielle Vieira ^{[1, 2]} ; de Sousa Neto, Ivo Vieira ^[3] ; Toledo-Arruda, Alessandra Choqueta ^{[4, 5]} ; Marqueti, Rita de Cassia ^[3] ; Vieira, Rodolfo P. ^{[6, 7, 8, 9]} ; Martins, Milton A. ^[5] ; Salvini, Tania ^[10] ; Durigan, Joao Luiz Quaglioti ^[11]

Affiliation:Show less -

^[1] Univ Brasilia, Phys Therapy Div, Brasilia, DF - Brazil

^[2] Univ Paulista, Dept Phys Therapy, Sgas Quadra 913 S-N, BR-70390130 Brasilia, DF - Brazil

^[3] Univ Brasilia, Grad Program Sci & Technol Hlth, Lab Mol Anal, Brasilia, DF - Brazil

^[4] Univ Fed Rio de Janeiro, Fac Physiotherapy, Rio De Janeiro - Brazil

^[5] Univ Sao Paulo, Sch Med, Dept Med Clin LIM 20, Sao Paulo - Brazil

^[6] Univ Brasil, Postgrad Program Bioengn, Sao Paulo - Brazil

^[7] Univ Fed Sao Paulo, Postgrad Program Sci Human Movement & Rehabil, Sao Paulo - Brazil

^[8] Nove de Julho Univ UNINOVE, Sao Paulo, SP - Brazil

^[9] Brazilian Inst Teaching & Res Pulm & Exercise Imm, Lab Pulm & Exercise Immunol LABPEI, Sao Paulo, SP - Brazil

^[10] Univ Fed Sao Carlos, Dept Phys Therapy, Sao Carlos - Brazil

^[11] Univ Brasilia, Rehabil Sci Grad Program, Brasilia, DF - Brazil

• Document type: Journal article
• Source: INTERNATIONAL JOURNAL OF CHRONIC OBSTRUCTIVE PULMONARY DISEASE; v. 17, p. 33-42, 2022.
• Web of Science Citations: 0

Abstract

Background: Long-term cigarette smoke (CS) induces substantive extrapulmonary effects, including musculoskeletal system disorders. Exercise training seems to protect long-term smokers against fiber atrophy in the locomotor muscles. Nevertheless, the extracellular matrix (ECM) changes in response to aerobic training remain largely unknown. Thus, we investigated the effects of moderate treadmill training on aerobic performance, crosssectional area (CSA), fiber distribution, and metalloproteinase 2 (MMP-2) activity on quadriceps muscle in mice exposed to chronic CS. Methods: Male mice were randomized into four groups: control or smoke (6 per group) and exercise or exercise+smoke (5 per group). Animals were exposed to 12 commercially filtered cigarettes per day (0.8 mg of nicotine, 10 mg of tar, and 10 mg of CO per cigarette). The CSA, fibers distribution, and MMP-2 activity by zymography were assessed after a period of treadmill training (50% of maximal exercise capacity for 60 min/day, 5 days/week) for 24 weeks. Results: The CS exposure did not change CSA compared to the control group (p 0.05), but minor fibers in the frequency distribution (<1000 mu m(2)) were observed. Long-term CS exposure attenuated CSA increases in exercise conditions (smoke+exercise vs exercise) while did not impair aerobic performance. Quadriceps CSA increased in mice nonsmoker submitted to aerobic training (p = 0.001). There was higher pro-MMP-2 activity in the smoke +exercise group when compared to the smoke group (p = 0.01). Regarding active MMP-2, the exercise showed higher values when compared to the control group (p = 0.001). Conclusion: Moderate treadmill training for 24 weeks in mice exposed to CS did not modify CSA, despite inducing higher pro-MMP-2 activity in the quadriceps muscle, suggesting limited effects on ECM remodeling. Our findings may contribute to new insights into molecular mechanisms for CS conditions. (AU)

• FAPESP's process: 12/15165-2 - Role of purinergic signaling and of SOCS-JAK-STAT signaling in the antiinflammatory effects of aerobic training in experimental models of asma and in asthmatic individuals
• Grantee: Rodolfo de Paula Vieira
• Support Opportunities: Research Grants - Young Investigators Grants