ALL STEM CELLS

The role of bone marrow-derived stem cells in lung regeneration and repair (2008)

Abstract
Adult stem cells posses the ability to undergo both self-renewal and differentiation in multiple lineages.
A recent body of work has utilised exogenous mesenchymal stem cells from the bone marrow compartment
to attenuate lung injury. Initial studies suggested that bone marrow-derived stem cells (BMSCs) could repair damaged tissue by differentiating into epithelial cells in disparate sites.
However this has been challenged and is now felt to be of limited clinical significance. What is clearer is that in chronic lung injury these cells are activated in response to tissue damage, migrate to the site of injury and contribute to both structural and functional repair. They are relatively non-immunogenic allowing them to be expanded and engineered ex vivo and re-introduced without immunomodulation. In acute lung injury BMSCs have been shown to reduce the pulmonary inflammatory response via a number of mechanisms to cause down-regulation of pro-inflammatory cytokines and a reduction in pathological lung damage. This chapter examines the role of exogenous bone marrow-derived cells, and in particular mesenchymal stem cells in both repair of chronic lung disease and acute lung injury, and their suitability as vectors for gene therapy.

2. Lung regeneration
Although initially thought to have a restricted cell lineage, studies undertaken at the start of this decade suggested that BMSCs may be capable of undergoing differentiation to produce progeny of other lineages (Jiang et al., 2002; Anjos-Afonso et al., 2004) a characteristic known as plasticity. One of the seminal studies involved female mice with lethally irradiated bone marrow receiving a single HSC from a male donor. Using techniques of both immunohistochemistry and Y chromosome detection, cell engraftment was demonstrated in both the donor bone marrow cell lineages and also epithelial organs including the lung, which showed engraftment making up to 20% of the lung parenchyma (Krause et al., 2001).

MSC : Increased migration / Increased survival / Increased proliferation

Source : http://www.stembook.org/node/499