Telomere length and oxidative stress variations in a murine model of Alzheimer's disease progression.

Alzheimer's disease (AD) is the most common cause of dementia, and ageing is its major risk factor. Changes in telomere length have been associated with ageing and some degenerative diseases. Our aim was to explore some of the molecular changes caused by the progression of AD in a transgenic murine model (3xTg-AD; B6; 129-Psen1 Tg (APPSwe, tauP301L) 1Lfa). Telomere length was assessed by qPCR in both brain tissue and peripheral blood cells and compared between three age groups: 5, 9 and 13 months. In addition, a possible effect of oxidative stress on telomere length and AD progression was explored. Shorter telomeres were found in blood cells of older transgenic mice compared to younger and wild-type mice but no changes in telomere length in the hippocampus. An increase in oxidative stress with age was found for all strains, but no correlation was found between oxidative stress and shorter telomere length for transgenic mice. Telomere length and oxidative stress are affected by AD progression in the 3xTg-AD murine model. Changes in blood cells are more noticeable than changes in brain tissue, suggesting that systemic changes can be detected early in the disease in this murine model.

BDNF and Tau as biomarkers of severity in multiple sclerosis.

AIM: Determine if serum levels of tau and BDNF can be used as severity biomarkers in multiple sclerosis (MS). PATIENTS & METHODS: Subjects with MS, older than 18 and younger than 55 years old were included; 74 patients with a diagnosis of relapsing-remitting MS, 11 with secondary-progressive MS, and 88 controls were included. Total tau and BDNF were measured by Western blot. RESULTS: Increased tau and decreased BDNF in MS patients compared with controls was found. Total-tau has a peak in relapsing-remitting MS, the second decile of the multiple sclerosis severity score, and in the lowest expanded disability status scale and is no different than controls for secondary-progressive MS patients and the most severe cases of MS. CONCLUSION: BDNF is a good biomarker for diagnosis of MS but not for severity or progression. Tau appears to have a more active role in the progression of MS.