Entwicklung und Anwendung eines Expressionsklonierungssystems in primären Kardiomyozyten - Identifizierung von Translin als neuem Target der Herzinsuffizienz

Development of an expression cloning system in primary
cardiomyocytes - Validation of Translin as a new target for heart
failure Congestive heart failure continues to represent a life
threatening disease with unmet medical need. Functional impairment
of the insufficient heart is reflected in altered geometry of the
left ventricle. On the cellular level, cardiac myocytes respond to
the increased biomechanical stress by different processes including
sarcomeric remodelling and changes in cell shape. In order to
identify new regulator genes for sarcomeric rearrangement, we
developed an expression cloning system in primary cardiomyocytes. A
normalized human heart library was integrated in an inducible
adenoviral vector system. After transduction of cardiomyocytes and
induction of the transgenes, cells were analyzed for morphological
changes reflecting the hypertrophic process. A new system based on
laser scanning cytometry was developed as read out. We managed to
screen hundreds of cDNAs leading to the discovery of the new target
protein Translin. Its overexpression caused the hypertrophic
elongation of cardiomyocytes in vitro and could be involved in the
pathologic regulation of posttranscriptional RNA processes. These
data correlated with the upregulation of Translin in the diseased
state of the human heart in vivo. In conclusion, this cell based
screen led to the functional characterization of a novel regulator
of heart disease providing a basis for the development of
innovative drugs for the causative treatment of the insufficient
human heart.