SOCS1 gene transfer accelerates the transition to heart failure through the inhibition of the gp130/JAK/STAT pathway

The suppressors of cytokine signalling (SOCS) are identified inhibitors of cytokine and growth factor signalling that act via the Janus kinase (JAK) signal transducers and activators of transcription (STAT) pathways. Aberrant JAK/STAT signalling promotes progression from hypertrophy to heart failure. Little information is available concerning the role of SOCS in the transition from hypertrophy to heart failure. To this aim, we investigated the effects of SOCS1 overexpression obtained by in vivo adeno-associated gene transfer using an aortopulmonary cross-clamping technique in a chronic pressure-overload cardiac rat model. Rats were randomized into four groups: sham-operated (n 18), aortic banding (AB) (n 18), AB viral vector encoding for haemoagglutinin (AB HA, n 16), and AB viral vector encoding for SOCS1 (AB SOCS1, n 18). Echocardiographic and haemodynamic measurements were performed 15 weeks after banding. While SOCS3 was upregulated during the hypertrophic phase, SOCS1 transcript levels increased significantly between 15 and 20 weeks. Remodelling was markedly worse in AB SOCS1, showed larger left ventricular internal dimensions (16), higher end-diastolic pressures (57) and wall stress (45), and reduced fractional shortening (32) compared with AB HA; apoptotic rate was increased threefold and the gp130 pathway was inhibited. Ex vivo experiments showed that mechanical stretch upregulated SOCS1 expression, which was in turn attenuated by tumour necrosis factor- (TNF-) inhibition. Enhanced SOCS1 myocardial signalling is associated with accelerated transition from hypertrophy to failure in an established model of pressure overload. SOCS1 may represent an attractive target for the prevention of heart failure progression.