Spontaneous coronary vasospasm due to polytrauma.

Coronary vasospasm is characterized by focal or diffuse spasm of an epicardial coronary artery. Definitive diagnosis is usually made with coronary angiography, when resolution of stenosis is observed after administration of intracoronary vasodilators. Coronary vasospasm is rarely a consequence of a blunt force injury to the chest. Among trauma induced cardiac complications, coronary vasospasm has been the least common with only one other reported case of coronary vasospasm induced by trauma. We report a rare case of severe spontaneous coronary vasospasm in a patient with polytrauma successfully treated with intracoronary, intravenous and oral vasodilator therapy. The mechanism is thought to be due to compensatory catecholamine response to trauma, and coronary vasospasm should be strongly suspected in trauma patients with unexplained hypotension, new conduction abnormalities or evidence of ischemia on the ECG.

MicroRNAs regulate renal tubule maturation through modulation of Pkd1.

MicroRNAs (miRNAs) contribute to the regulation of early kidney development, but their role during later stages of renal tubule maturation is not well understood. Here, we found that ablation of the miRNA-processing enzyme Dicer from maturing renal tubules produces tubular and glomerular cysts in mice. Inactivation of Dicer is associated with downregulation of miR-200, a kidney-enriched miRNA family, and upregulation of the polycystic kidney disease gene Pkd1. Inhibition of miR-200 in cultured renal epithelial cells disrupted tubulogenesis and led to upregulation of Pkd1. Using bioinformatic and in vitro approaches, we found that miR-200b/c/429 induce post-transcriptional repression of Pkd1 through two conserved binding sites in the 3'-Untranslated regions of Pkd1. Overexpression of PKD1 in renal epithelial cells was sufficient to disrupt tubulogenesis and produce cyst-like structures. In conclusion, miRNAs are essential for the maturation of renal tubules, and Pkd1 is a target of miR-200. These results also suggest that miRNAs may modulate PKD1 gene dosage and play a role in the initiation of cystogenesis.