| First Author | Fässler R | Year | 1996 |
| Journal | J Cell Sci | Volume | 109 ( Pt 13) |
| Pages | 2989-99 | PubMed ID | 9004034 |
| Mgi Jnum | J:37583 | Mgi Id | MGI:84974 |
| Doi | 10.1242/jcs.109.13.2989 | Citation | Fassler R, et al. (1996) Differentiation and integrity of cardiac muscle cells are impaired in the absence of beta 1 integrin. J Cell Sci 109(Pt 13):2989-99 |
| abstractText | Cellular interactions with substrata of the microenvironment are one of the major mechanisms for differentiation and morphogenesis. Many of these interactions are mediated via the beta 1 integrin subfamily of cell surface receptors, which are believed to transduce signals upon cell adhesion. We have used beta 1 integrin-deficient embryonic stem cells to test their ability to differentiate into cardiac muscle cells. We show here by several approaches that beta 1 integrin is important for normal cardiogenesis. First, the in vitro differentiation of beta 1 integrin-deficient embryonic stem cells into cardiac muscle cells is retarded. This is demonstrated by the delayed expression of cardiac muscle-specific genes and action potentials. Second, the specification of cardiac precursor cells into pacemaker-, atrial- and ventricular-like cells is significantly impaired in beta 1 integrin-deficient cells. The occurrence of atrial- and ventricular-like cells is reduced and transient. Only cells exhibiting peacemaker-like action potentials of high frequency and arrhythmias survive. Third, the sarcomeric architecture is incomplete and disarranged in the absence of beta 1 integrin. Fourth, beta 1-deficient embryonic stem cells can contribute to the developing heart in chimaeric mice but many areas with beta 1-null cells contain cell debris. The number of beta 1-null cells decrease from prenatal to postnatal stages and is lost completely in 6-month-old hearts. Thus, we conclude that interactions with the extracellular matrix via beta 1 integrin is necessary for differentiation and the maintenance of a specialized phenotype of cardiac muscle cells. |
