Comparative studies on [Ca2+]i-level of fibroblasts from Alzheimer patients and control individuals

The accumulation of the beta -amyloid peptide (PAP) in the brain, produced from the ubiquitously expressed amyloid precursor protein (APP) is a defining feature of Alzheimer's disease (AD). Consistent with studies demonstrating the importance of skin biopsy in the diagnosis of neurodegenerative disorders, we investigated whether differences in intracellular free calcium levels ( Ca2+](i)) of cultured cutaneous fibroblasts derived from sporadic AD patients and from age matched control individuals might be present. Ca2+](i) was measured in Fura-2AM-loaded human fibroblasts by dual wavelength spectrofluorimetry. AD cells exhibited lower [Ca2+]i as compared to the control cultures. Exposure of fibroblasts to beta AP resulted in increased [Ca (2+)](i) of the control cells, but not of AD fibroblasts. Our test could prove useful in supporting the diagnosis of (sporadic) AD in patients suspected of suffering from the disease.