Use of adult mesenchymal stromal cells in tissue repair: impact of physical exercise

Abstract

Physical exercise (PE) has unquestionable beneficial effects on health, which likely extend into several organ-to-cell physiological processes. At the cell scale, endogenous mesenchymal stromal cells (MSCs) contribute to tissue repair, although their repair capacities may be insufficient in paucicellular or severely damaged tissues. For this reason, MSC transplantation holds great promise for tissue repair. With the goals of understanding if PE has beneficial effects on MSC biology and if PE potentiates their role in tissue repair, we reviewed literature reports regarding the effects of PE on MSC properties (specifically, proliferation, differentiation, and homing) and of a combination of PE and MSC transplantation on tissue repair (specifically neural, cartilage, and muscular tissues). Contradictory results have been reported; interpretation is complicated because various and different species, cell sources, and experimental protocols, specifically exercise programs, have been used. On the basis of these data, the effects of exercise on MSC proliferation and differentiation depend on exercise characteristics (type, intensity, duration, etc.) and on the characteristics of the tissue from which the MSCs were collected. For the in vitro studies, the level of strain (and other details of the mechanical stimulus), the time elapsed between the end of exposure to strain and MSC collection, the age of the donors, as well as the passage number at which the MSCs are evaluated also play a role. The combination of PE and MSC engraftment improves neural, cartilage, and muscular tissue recovery, but it is not clear whether the effects of MSCs and exercise are additive or synergistic.

Keywords: differentiation; mesenchymal stromal cells; physical exercise; proliferation; repair.

Fig. 1.

Effects of physical exercise on mesenchymal stromal cell (MSC) properties. The effects of physical exercise on MSC proliferation, apoptosis, and homing (A) and differentiation (osteogenic, adipogenic and tenogenic) (B) capacities are presented. Green arrows indicate a positive effect (increased capacity), red arrows indicate a negative effect (decreased capacity), and blue arrows indicate an absence of effect (similar capacity) of physical exercise on MSC properties.

Fig. 2.

The effects of a combination of physical exercise and mesenchymal stromal cell (MSC) transplantation on tissue repair. The effects of a combination of physical exercise and MSC transplantation on cartilage repair and on the functional recovery of cardiac, cerebral, and neural injuries are presented. Green arrows indicate a positive effect of this combination on tissue repair, and blue arrows indicate the absence of effect.