Neuropeptide Kyotorphin (Tyrosyl-Arginine) has Decreased Levels in the Cerebro-Spinal Fluid of Alzheimer’s Disease Patients: Potential Diagnostic and Pharmacological Implications

Sara Matos Santos,Laura Garcia-Nimo,José A Cocho,Miguel A R B Castanho,Isaura Tavares,Sónia Sá Santos

doi:10.3389/fnagi.2013.00068

Sara Matos Santos, Laura Garcia-Nimo + Show 4 more

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https://doi.org/10.3389/fnagi.2013.00068

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Abstract

In Alzheimer’s disease (AD), besides the characteristic deterioration of memory, studies also point to a higher pain tolerance in spite of sensibility preservation. A change in the normal tau protein phosphorylation is also characteristic of AD, which contributes to the pathogenesis of the disease and is useful in early diagnosis. Kyotorphin (KTP) is an endogenous analgesic dipeptide (Tyr-Arg) for which there is evidence of eventual neuroprotective and neuromodulatory properties. The objective of this work was to study the possible correlation between KTP and phosphorylated tau protein (p-tau) levels in cerebro-spinal fluid (CSF) samples of AD patients. CSF samples were collected from 25 AD patients and 13 age-matched controls (N), where p-tau and KTP levels were measured. We found a statistically significant difference between p-tau/KTP values in AD and N groups with an inverse correlation between p-tau and KTP values in AD samples. These results suggest that in the future KTP may be a candidate biomarker for neurodegeneration and may be a lead compound to be used pharmacologically for neuroprotection.

Highlights

Medical and pharmacological developments in recent years have allowed a significant increase in aging of the population
These patients were classified in clinical grounds as having Alzheimer’s Disease (AD) in moderate stage, with mini-mental state examination (MMSE) values of 14.3 ± 6
Our study is in agreement with previous studies aiming at other neuromolecules (Sulkava et al, 1985; Blennow et al, 2010) that have shown that in AD and vascular dementia, as the disease progresses several neuropeptides levels fall

Summary

Introduction

Medical and pharmacological developments in recent years have allowed a significant increase in aging of the population. Concomitant with the aging of the population the number of people with dementia has increased. Alzheimer’s Disease (AD) is the most prevalent neurodegenerative disease associated with dementia. It is a progressive debilitating disease with no known effective cure. Symptoms of memory loss begin at a variable age, usually between 40 and 65 years of age, progressing with over the years. It is expected that the current number of cases doubles by 2030, with a huge social and economic impact (Knickman and Snell, 2002)

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