The diphenylpyrazole compound anle138b blocks Aβ channels and rescues disease phenotypes in a mouse model for amyloid pathology

Alzheimer's disease is a devastating neurodegenerative disease eventually leading to dementia. An effective treatment does not yet exist. Here we show that oral application of the compound anle138b restores hippocampal synaptic and transcriptional plasticity as well as spatial memory in a mouse model for Alzheimer's disease, when given orally before or after the onset of pathology. At the mechanistic level, we provide evidence that anle138b blocks the activity of conducting Aβ pores without changing the membrane embedded Aβ-oligomer structure. In conclusion, our data suggest that anle138b is a novel and promising compound to treat AD-related pathology that should be investigated further.

Insulin growth factor binding protein 7 is a novel target to treat dementia

Alzheimer's disease (AD) is the most common form of dementia in the elderly but effective therapeutic strategies to treat AD are not yet available. This is also due to the fact that the pathological mechanisms that drive the pathogenesis of sporadic AD are still not sufficiently understood and may differ on the individual level. Several risk factors such as altered insulin-like peptide (ILP) signaling have been linked to AD and modulating the ILP system has been discussed as a potential therapeutic avenue. Here we show that insulin-like growth factor binding protein 7 (IGFBP7), a protein that attenuates the function of ILPs, is up-regulated in the brains of AD patients and in a mouse model for AD via a process that involves altered DNA-methylation and coincides with decreased ILP signaling. Mimicking the AD-situation in wild type mice, by increasing hippocampal IGFBP7 levels leads to impaired memory consolidation. Consistently, inhibiting IGFBP7 function in mice that develop AD-like memory impairment reinstates associative learning behavior. These data suggest that IGFBP7 is a critical regulator of memory consolidation and might be used as a biomarker for AD. Targeting IGFBP7 could be a novel therapeutic avenue for the treatment of AD patients.

MeCP2 mutant protein is expressed in astrocytes as well as in neurons and localizes in the nucleus

The MECP2 gene, located at Xq28, encodes methyl-CpG-binding protein 2 (MeCP2), which is frequently mutated (up to 90%) in Rett syndrome (RTT). RTT is a progressive neurodevelopmental disorder, which affects primarily girls during early childhood and it is one of the most common causes of mental retardation in females. R270X is one of the most frequent recurrent MECP2 mutations among RTT cohorts. The R270X mutation resides within the TRD-NLS (Transcription Repression Domain-Nuclear Localization Signal) region of MeCP2 and causes a more severe clinical phenotype with increased mortality as compared to other mutations. To evaluate the functional role of the R270X mutation, we generated a transgenic mouse model expressing MeCP2(270_EGFP) (human mutation equivalent) by BAC recombineering. The expression pattern of MeCP2(270_EGFP) was similar to that of endogenous MeCP2. Strikingly, MeCP2(270_EGFP) localizes in the nucleus, contrary to the conjecture that R270X could cause disruption of the NLS. In primary hippocampal cells, we show that MeCP2(270_EGFP) was expressed in astrocytes by colocalization with the astrocyte-specific marker glial fibrillary acidic protein. Our data showing expression of MeCP2(270_EGFP) in transgenic mice astrocytes further reinforce the recent findings concerning the expression of MeCP2 in the glial cells.