Integrin-linked kinase expression is elevated in human cardiac hypertrophy and induces hypertrophy in transgenic mice.

BACKGROUND: Although numerous signaling pathways are known to be activated in experimental cardiac hypertrophy, the molecular basis of the hypertrophic response inherent in human heart diseases remains largely unknown. Integrin-linked kinase (ILK) is a multifunctional protein kinase that physically links beta-integrins with the actin cytoskeleton, suggesting a potential mechanoreceptor role. METHODS AND RESULTS: Here, we show a marked increase in ILK protein levels in hypertrophic ventricles of patients with congenital and acquired outflow tract obstruction. This increase in ILK was associated with activation of the Rho family guanine triphosphatases, Rac1 and Cdc42, and known hypertrophic signaling kinases, including extracellular signal-related kinases (ERK1/2) and p70 S6 kinase. Transgenic mice with cardiac-specific expression of a constitutively active ILK (ILK(S343D)) or wild-type ILK (ILK(WT)) exhibited a compensated ventricular hypertrophic phenotype and displayed an activation profile of guanine triphosphatases and downstream protein kinases concordant with that seen in human hypertrophy. In contrast, transgenic mice with cardiomyocyte-restricted expression of a kinase-inactive ILK (ILK(R211A)) were unable to mount a compensatory hypertrophic response to angiotensin II in vivo. CONCLUSIONS: Taken together, these results identify ILK-regulated signaling as a broadly adaptive hypertrophic response mechanism relevant to a wide range of clinical heart disease.

Severe transient myocardial ischaemia caused by hypertrophic cardiomyopathy in a patient with congenital disorder of glycosylation type Ia.

UNLABELLED: Severely affected children with congenital disorder of glycosylation type Ia (CDG-Ia; MIM 212065) may develop hypertrophic cardiomyopathy. In this report we describe the near-death of a 10-month-old girl with CDG-Ia due to acute left-ventricular outlet obstruction caused by hypertrophic cardiomyopathy and acute dehydration. The girl had multi-organ failure and signs of severe myocardial damage mimicking myocardial infarction. CONCLUSION: hypertrophic cardiomyopathy contributes to the high mortality of young children with congenital disorder of glycosylation type Ia. Even if cardiomyopathy in this disease is non-obstructive, acute fluid-loss might cause left ventricular outflow tract obstruction and life-threatening myocardial ischaemia. Patients with congenital disorder of glycosylation type Ia are at risk for cardiac complications and should be monitored regularly by echocardiography.