No abstract

Owing to the large size of chromosome 2, partial monosomy of the long arm of this chromosome gives rise to many specific phenotypes. We report on a 2-month-old girl with an interstitial deletion of 2q24.2q24.3, which was confirmed by microarray-based comparative genomic hybridization analysis. The patient showed delayed growth and mental retardation, early myoclonic seizures, and characteristic dysmorphic features including thick arched eyebrows, upslanting palpebral fissures, long eyelashes, depressed nasal bridge, short nose, long philtrum, small mouth, micrognathia, and low set ears. Her early myoclonic seizures were likely due to haploinsufficiency of SCN1A and SCN2A, which are included in the deletion region. When she experienced acute bronchopneumonia, she showed severe pulmonary emphysema. The deletion region of 2q24.2 includes the integrin beta6 gene (ITGB6), which may prevent acute lung injury and pulmonary emphysema. Many previously reported patients with deletions of 2q24.2 showed poor outcomes because of respiratory failure. These observations suggest the possibility of a strong relationship between haploinsufficiency of ITGB6 and pulmonary dysfunction.

No abstract

The extracellular deposition of amyloid β (Aβ) is known to be the fundamental cause of Alzheimer's disease (AD). Aβ1-42, generated by β-secretases from the amyloid precursor protein (APP), is the main component of neuritic plaque, and the aggregation of this protein is shown to be dependent to an extent on metal ions such as copper and zinc. However, the mechanism by which Cu affects the physicochemical properties of Aβ1-42 or the central nervous system is still under debate. A recent series of studies have demonstrated that both the soluble-type matrix metalloproteinases (MMP-2 and MMP-9) and the membrane-type matrix metalloproteinase (MT1-MMP) are capable of degrading Aβ peptides. MMP-7, one of the soluble-type matrix metalloproteinases, is expressed in hippocampal tissue; however, less information is available concerning the pathophysiological roles of this enzyme in the process and/or progress of Alzheimer's disease. In this study, we examined the degradation activity of MMP-7 against various Aβ1-42's fragment peptides and the effect of Cu. Although Aβ22-40 was degraded by MMP-7 regardless of Cu, Cu inhibited the degradation of Aβ1-19, Aβ11-20, and Aβ11-29 by MMP-7. These results indicate that MMP-7 is capable of degrading Aβ1-42, and that Aβ1-42 acquired resistance against MMP-7 cleavage through Cu-binding and structure changes. Our results demonstrate that MMP-7 may play an important role in the defensive mechanism against the aggregation of Aβ1-42, which gives rise to the pathology of AD.

We have recently reported about shorter proteolytic peptides termed Catalytide as general name. JAL-TA9 (YKGSGFRMI), a fragment peptide derived from Box A region of Tob1 protein, is the first Catalytide and cleaves Aβ42 and its fragment peptides.Herein, we demonstrate the enzymatic properties of ANA-TA9 corresponding region to JAL-TA9 in ANA/BTG3 protein. ANA-TA9 showed the auto-proteolytic activity and cleaved 3 kinds of synthetic fragment peptides derived from Aβ42, especially on the central region of Aβ42 with a serine protease like activity. Interestingly, 2 kinds of components, ANA-SA5 (SKGQA) and ANA-YA4 (YRMI), also showed similar proteolytic activity. These results indicate that ANA-TA9 is composed of two different Catalytides.