Laboratory of Molecular Analysis, Graduate Program of Sciences and Technology of Health, Universidade de Brasília, Distrito Federal, Brazil.
Graduate Program in Rehabilitation Sciences, Universidade de Brasília, Distrito Federal, Brazil.
Clin Interv Aging. 2021 Jan 8;16:71-81. doi: 10.2147/CIA.S276518. eCollection 2021.
Aging decreases osteogenic ability, inducing harmful effects on the bone extracellular matrix (ECM), while exercise training has been indicated as a tool to counteract bone disorders related to advancing age. The modulation of bone ECM is regulated by several types of matrix metalloproteinase (MMP); however, MMP-2 activity in different trabecular bones in response to resistance training (RT) has been neglected. Remodeling differs in different bones under the application of the same mechanical loading. Thus, we investigated the effects of 12 weeks of RT on MMP-2 activity in the lumbar vertebra (L6), tibia, and femur of young (3 months) and older rats (21 months).
Twenty Wistar rats were divided into four groups (five animals per group): young sedentary or trained and older sedentary or trained. The 12-week RT consisted of climbing a 1.1-m vertical ladder three times per week with progressive weights secured to the animals' tails. The animals were killed 48 h after the end of the experimental period. The MMP-2 activity was assessed by the zymography method.
The aging process induced lower MMP-2 activity in the lumbar vertebrae and tibia (=0.01). RT upregulated pro, intermediate, and active MMP-2 activity in the tibia of young rats (=0.001). RT also upregulated pro and active MMP-2 activity in the lumbar vertebrae and tibia with advancing age (=0.01). There was no significant difference (>0.05) between groups for MMP-2 of the femur, regardless of age and RT.
The aging process impairs MMP-2 activity, but RT is a potential therapeutic approach to minimize the deleterious effects of ECM degeneration in different aged bones. Distinct MMP-2 responses to exercise training may result in specific remodeling processes.
衰老会降低成骨能力，对骨骼细胞外基质（ECM）产生有害影响，而运动训练已被证明是对抗与年龄增长相关的骨骼疾病的一种手段。几种类型的基质金属蛋白酶（MMP）调节骨 ECM 的重塑；然而，抗阻训练（RT）对不同骨小梁中 MMP-2 活性的影响尚未被关注。在应用相同机械负荷的情况下，不同骨骼的重塑方式不同。因此，我们研究了 12 周 RT 对年轻（3 个月）和老年（21 个月）大鼠腰椎（L6）、胫骨和股骨中 MMP-2 活性的影响。
将 20 只 Wistar 大鼠分为四组（每组 5 只）：年轻安静或训练组和老年安静或训练组。12 周 RT 包括每周三次爬上 1.1 米高的垂直梯子，在动物的尾巴上绑上逐渐增加的重量。实验结束后 48 小时处死动物。通过酶谱法评估 MMP-2 活性。
衰老过程导致腰椎和胫骨中的 MMP-2 活性降低（=0.01）。RT 上调了年轻大鼠胫骨中 pro、中间和活性 MMP-2 活性（=0.001）。RT 还上调了老年大鼠腰椎和胫骨中 pro 和活性 MMP-2 活性（=0.01）。无论年龄和 RT 如何，股骨的 MMP-2 各组之间均无显著差异（>0.05）。
衰老过程会损害 MMP-2 活性，但 RT 是一种潜在的治疗方法，可以最小化 ECM 退化对不同年龄骨骼的有害影响。对运动训练的不同 MMP-2 反应可能导致特定的重塑过程。
