Deficiency of GDNF Receptor GFRα1 in Alzheimer's Neurons Results in Neuronal Death.

We have recently developed aged cortical neuron cultures from autopsied human brains with Alzheimer's disease (AD). During the culturing process, we found that glutamatergic cortical neurons from the AD brain lacked a response to glial cell line-derived neurotrophic factor (GDNF), including no axonal regrowth, and were starting to undergo apoptosis. Here we showed that, in cortical neurons from age- and gender-matched cognitively normal control (NC) subjects (NC neurons), GDNF enhanced the expression of GDNF family receptor subtype α1 (GFRα1), but not the other three subtypes (GFRα2, GFRα3, and GFRα4), whereas GDNF failed to induce GFRα1 expression in cortical neurons from the AD brain (AD neurons).

Amyloid beta peptide load is correlated with increased beta-secretase activity in sporadic Alzheimer's disease patients.

Whether elevated beta-secretase (BACE) activity is related to plaque formation or amyloid beta peptide (Abeta) production in Alzheimer's disease (AD) brains remains inconclusive. Here, we report that we used sandwich enzyme-linked immunoabsorbent assay to quantitate various Abeta species in the frontal cortex of AD brains homogenized in 70% formic acid. We found that most of the Abeta species detected in rapidly autopsied brains (<3 h) with sporadic AD were Abeta(1-x) and Abeta(1-42), as well as Abeta(x-42).

Isolation of living neurons from human elderly brains using the immunomagnetic sorting DNA-linker system.

Isolation and culture of mature neurons from affected brain regions during diseased states provide a well-suited in vitro model system to study age-related neurodegeneration under dynamic conditions at cellular levels. We have developed a novel technique to isolate living neurons from rapidly autopsied human elderly brains, and have succeeded in keeping them alive in vitro. Specifically, the parietal cortex blocks were fractionated by density gradients and further enriched for neurons by an immunomagnetic sorting DNA-linker technique.