Characterization of hMSCs transmigrated through collagen barrier

Abstract

Stem cell therapy is a promising approach for tissue regeneration but there exists a

problem of low engraftment rate to the injury site. Our laboratory has shown that

hMSCs that were capable to penetrate through collagen barrier have higher

migration capacity and engraftment efficiency than those remained inside the

collagen matrix and those in traditional 2D culture. These cells capable of

penetrating through collagen barrier might be hopeful candidate for improving

engraftment efficacy. Major processes of engraftment, such as transmigration

through basement membrane and invasion to the site of injury, involve

cell-extracellular matrix-interacting proteins. As matrix metalloproteinases (MMP)

and integrins are the key players in these processes, MMP and integrin profiles of

the hMSCs were studied

In this study, we demonstrated that hMSCs that were capable of penetrating

through the collagen barrier have distinctive MMP profile to traditional 2D culture.

These cells secrete significantly higher amount of MMP-1 than 2D culture, but the

amount of MMP-2 secreted is comparable to traditional 2D culture. On the other

hand, MMP-9 and MMP-13 were below detection limit by ELISA in both groups.

Moreover, we have investigated the subcellular localization of MMPs and

integrins. The cells were seeded on dishes with or without ECM coatings. It was

demonstrated that hMSCs capable of penetrating through collagen barrier exhibit

higher amount of subcellular MT1-MMP and integrin 6271 on ECM coated dish.

Moreover, these cells exhibit a prominent feature of perinuclear localization of

MT1-MMP., whereas the level of subcellular MMP-2, integrin 65 and 6v73 is

comparable to that in 2D culture.

We have also investigated the stem properties of hMSCs penetrated through

collagen barrier. These properties include proliferation capacity, self-renewal

capacity and differentiation potential towards chondrogenic, osteogenic and

adipogenic lineages. It has been demonstrated that these properties are not

compromised for superior migratory activities.