Ciliary neurotrophic factor prevents degeneration of motor neurons in mouse mutant progressive motor neuronopathy.

Ciliary neurotrophic factor (CNTF) supports the survival of embryonic motor neurons in vitro and in vivo, and prevents lesion-mediated degeneration of rat motor neurons during early post-natal stages. Here we report that CNTF greatly reduces all the functional and morphological changes in pmn/pmn mice, an autosomal recessive mutant leading to progressive caudo-cranial motor neuron degeneration. The first manifestations of progressive motor neuronopathy in homozygous pmn/pmn mice become apparent in the hind limbs at the end of the third post-natal week, and all the mice die up to 6 or 7 weeks after birth from respiratory paralysis. Treatment with CNTF prolongs survival and greatly improves motor function of these mice. Moreover, morphological manifestations, such as loss of motor axons in the phrenic nerve and degeneration of facial motor neurons, were greatly reduced by CNTF, although the treatment did not start until the first symptoms of the disease had already become apparent and substantial degenerative changes were already present. The protective and restorative effects of CNTF in this mouse mutant give new perspectives for the treatment of human degenerative motor neuron diseases with CNTF.     

Specific inhibition of human leukocyte elastase by substituted alpha-pyrones

Summary Severala-pyrones have been synthesized and investigated for their in vitro inhibitory activity usinga-chymotrypsin (a-CT), porcine pancreatic elastase, (PPE) and human leukocyte elastase (HLE). 4-Hydroxy-6-undecyl-2H-pyran-2-one4, 4-Hydroxy-6-[(1-butyl)heptyl]-2H-pyran-2-one5 and 4-Methoxy-6-[(1-butyl)heptyl]-2H-pyran-2-one6 were found to be specific inhibitors of HLE. These compounds constitute a promising new class of HLE inhibitors.Acknowledgments. We are grateful to the Petroleum Research Fund of the American Chemical Society (Grant No. 13058-B4), the American Lung Association and the Office of Sponsored Research of Wichita State University for generous financial support of this work. This work was also supported by NHLBIGrant 5PO1HL20994 and the Council for Tobacco Research, USA-Inc. Grant 901B.     

Crystal structure of insecticidal delta-endotoxin from Bacillus thuringiensis at 2.5 A resolution.

The structure of the delta-endotoxin from Bacillus thuringiensis subsp. tenebrionis that is specifically toxic to Coleoptera insects (beetle toxin) has been determined at 2.5 A resolution. It comprises three domains which are, from the N- to C-termini, a seven-helix bundle, a three-sheet domain, and a beta sandwich. The core of the molecule encompassing all the domain interfaces is built from conserved sequence segments of the active delta-endotoxins. Therefore the structure represents the general fold of this family of insecticidal proteins. The bundle of long, hydrophobic and amphipathic helices is equipped for pore formation in the insect membrane, and regions of the three-sheet domain are probably responsible for receptor binding.     

Maternal control of Drosophila segmentation gene expression

Several genes have been identified that are involved in establishing the segmented body pattern during development of the fruit-fly Drosophila melanogaster. These fall into several classes on the basis of the kind of alteration to the wild-type segmentation pattern observed in mutant embryos. For example, mutations of the pair-rule class, such as fushi tarazu (ftz), cause the deletion of pattern elements with a two-segment periodicity; those of the gap class, such as knirps, cause the deletion of contiguous groups of segments. The availability of antibodies against the ftz protein has allowed its spatial pattern of expression to be studied during the development of wild-type and mutant embryos. The aim of the latter kind of experiment is to investigate possible interactions between these important genes. We have recently reported that knirps mutations cause a striking alteration to the pattern of transverse stripes of ftz expression usually seen during embryogenesis. Knirps is a zygotically-expressed gene, but recently a class of maternally-active genes has been identified that causes similar defects in pattern formation. We have now investigated the pattern of ftz expression in mutants of this class and have found that while they do have features seen in knirps mutants, they also exhibit significant differences between the different mutations reflecting the distinct but overlapping domains of gene activity. These observations demonstrate that maternally-active segmentation genes regulate zygotic gene expression, and that some of their effects on ftz may be directed through the knirps gene.