Remodeling process in bone of aged rats in response to resistance training

Author(s):Show less -

de Farias Junior, Goncalo Carreiro ^{[1, 2]} ; Neto, Ivo Vieira de Sousa ^[2] ; Guzzoni, Vinicius ^[3] ; Pisani, Graziele Deriggi ^[4] ; Royer, Carine ^[5] ; de Lima, Caroline Lourenco ^[5] ; Neves, Francisco de Assis Rocha ^[5] ; Bogni, Fabio Henrique ^[4] ; Nonaka, Keico Okino ^[4] ; Durigan, Joao Luiz Quagliotti ^{[1, 2]} ; Selistre-de-Araujo, Heloisa Sobreiro ^[4] ; Marqueti, Rita de Cassia ^{[1, 2]}

Affiliation

^[1] Univ Brasilia, Grad Program Rehabil Sci, Brasilia, DF - Brazil

^[2] Univ Brasilia, Fac Ceilandia, Lab Mol Anal, Brasilia, DF - Brazil

^[3] Univ Fed Paraiba, Dept Cellular & Mol Biol, Joao Pessoa, Paraiba - Brazil

^[4] Univ Fed Sao Carlos, Dept Physiol Sci, Sao Paulo - Brazil

^[5] Univ Brasilia, Fac Hlth Sci, Lab Mol Pharmacol, Brasilia, DF - Brazil

• Document type: Journal article
• Source: Life Sciences; v. 256, SEP 1 2020.
• Web of Science Citations: 0

Abstract

Aims: We investigate the effects of RT on the mechanical function, gene, and protein expression of key factors involved in bone remodeling during aging. Main methods: Male rats of 3 and 21 months of age were randomly allocated into four groups (8 per group): young sedentary (YS), young trained (YT), old sedentary (OS), and old trained (OT). RT was performed three times per week (12 weeks). Bone tenacity and stiffness were measured by biomechanical tests and mRNA levels of COL1A1, MEPE, SOST, OPG, BMP-2, PPAR-y, MMP-2-9-13, and TIMP-1 were evaluated by quantitative PCR. COL1A1 protein and MMP-2 activity were detected by western blotting and zymography assays. Key findings: Aging increased stiffness, while BMP-2, OPG, COL1A1 and MMP-2 mRNA levels reduced (OS vs YS; p <= 0.05). RT increased the tenacity of the femur and reduced PPAR-gamma regardless of age (YT vs. YS; OT vs. OS; p <= 0.05). RT downregulated SOST mRNA levels only in the OT group (vs. OS group, p <= 0.05). RT mitigated the age-associated increase in MMP-9 mRNA levels (p <= 0.05). In young animals, upregulation in MEPE, MMP-13, TIMP-1 were observed after RT, as well an increase in COL1A1 protein and MMP-2 activity (p <= 0.05). Significance: RT improved bone tenacity independent of aging, which is relevant for mechanical function, while, at protein levels, RT upregulated MMP-2 activity and collagen 1 only in young rats. This study highlights the importance of exercise on bone health and identifies specific molecular changes in response to RT. Our findings provide insights into the mechanisms involved in age-related changes. (AU)

• FAPESP's process: 10/19390-5 - Aging-related alterations in extracellular matrix and its adaptations to strength training in Calcaneal tendon of rats: molecular, cellular, and biomechanical approach.
• Grantee: Rita de Cássia Marqueti Durigan
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 11/11229-3 - Aging-related alterations in extracellular matrix and its adaptations to strength training in calcaneal tendon of rats: molecular, cellular, and biomechanical approach
• Grantee: Heloisa Sobreiro Selistre de Araújo
• Support Opportunities: Regular Research Grants
• FAPESP's process: 13/00798-2 - The extracellular matrix in aging, exercise and in the tumor microenvironment
• Grantee: Heloisa Sobreiro Selistre de Araújo
• Support Opportunities: Research Projects - Thematic Grants