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Alveolar capillary dysplasia with misalignment of pulmonary veins (ACDMPV) is a lethal congenital lung disorder that presents shortly after birth with respiratory failure and therapy-resistant pulmonary hypertension. It is associated with heterozygous point mutations and genomic deletions that involve the FOXF1gene or its upstream regulatory region. Patients are unresponsive to the intensive treatment regimens and suffer unnecessarily because ACDMPV is not always timely recognized and histologic diagnosis is invasive and time consuming. Here, we demonstrate the usefulness of a noninvasive, fast genetic test for FOXF1variants that we previously developed to rapidly diagnose ACDMPV and reduce the time of hospitalization.

A neuronal membrane protein, neuropathy target esterase (NTE), reacts with those organophosphates that initiate a syndrome of axonal degeneration. NTE has homologues in Drosophilaand yeast and is detected in vitroby assays with a non-physiological ester substrate, phenyl valerate. We report that NEST, the recombinant esterase domain of NTE (residues 727–1216) purified from bacterial lysates, can catalyze hydrolysis of several naturally occurring membrane-associated lipids. The active site regions of NEST and calcium-independent phospholipase A2(iPLA2) share sequence similarity, and the phenyl valerate hydrolase activity of NEST is inhibited by low concentrations of iPLA2inhibitors. However, on incubation with NEST, fatty acid was liberated only extremely slowly from the sn-2 position of phospholipids (Vmax∼0.01 μmol/min/mg and Km∼0.4 mmfor 1-palmitoyl, 2-oleoylphosphatidylcholine). Comparison of the NEST-mediated generation of 14C-labeled products from two differentially labeled 14C-phospholipid substrates suggested that a rate-limiting sn-2 cleavage was followed very rapidly by hydrolysis of the resulting lysophospholipid. Among the various naturally occurring lipids tested with NEST, lysophospholipids were by far the most avidly hydrolyzed substrates (Vmax∼20 μmol/min/mg and Km∼0.05 mmfor 1-palmitoyl-lysophosphatidylcholine). NEST also catalyzed the hydrolysis of monoacylglycerols, preferring the 1-acyl to the 2-acyl isomer (Vmax∼1 μmol/min/mg and Km∼0.4 mmfor 1-palmitoylglycerol). NEST did not catalyze hydrolysis of di- or triacylglycerols or fatty acid amides. This demonstration that membrane lipids are its putative cellular substrates raises the possibility that NTE and its homologues may be involved in intracellular membrane trafficking.