Identification of thymosins ß4 and ß 10 in paediatric craniopharyngioma cystic fluid.

BACKGROUND: Adamantinomatous craniopharyngioma is the third most recurrent paediatric brain tumour. Although histologically benign, it behaves aggressively as a malignant tumour due to invasion of the hypothalamus and visual pathways. Surgery is still the first and almost the only mode of treatment, although serious damage can occur as a consequence of tumour localization. The proteomic characterization of the intracystic tumoural fluid could contribute to the comprehension of the tumorigenesis processes and to the development of therapeutic targets to reduce cyst volume, allowing less invasive surgery and/or delay of the radical resection of the tumour mass and the collateral serious effects. METHODS: Intracystic fluid was analysed by a LC-ESI-IT-MS top-down platform after acidification, deproteinization and chloroform liquid/liquid extraction. FINDINGS: Thymosin ß4 and ß10 peptides were for the first time identified in the intracystic fluid of adamantinomatous craniopharyngioma by low- and high-resolution MS analysis coupled with LC. The two peptides showed the same distribution trend in the analysed samples. Thymosin ß4 and ß10 were present in 77 % of the analysed samples. These peptides were not found in the cerebrospinal fluid available for two patients. INTERPRETATION: The presence of ß-thymosins in the intracystic fluid of the tumour confirmed the secretion of these proteins in the extracellular environment. Due to their G-actin-sequestering activity and antiapoptotic and anti-inflammatory properties, these peptides could be strictly involved in both tumour progression and cyst development and growth.

Contribution of cerebrospinal fluid thymosin ß4 levels to the clinical differentiation of Creutzfeldt-Jakob disease.

OBJECTIVE: To asses thymosin ß4 specificity as relevant to the diagnosis of Creutzfeldt-Jakob disease (CJD). DESIGN: A matrix-assisted laser desorption ionization time-of-flight mass spectrometry protein profiling analysis was applied to several neurological disorders that are known to lead to dementia. The relative peak area (percentage of area) of the thymosin ß4 MS signal was taken into account. SETTING: National Research Council, Cosenza, Italy. PATIENTS: Cerebrospinal fluid analysis was performed on 21 patients with neuropathologically confirmed CJD; 15 patients with frontotemporal dementia; 18 patients with probable Alzheimer disease; and 9 patients with a rapid-onset progressive dementia. A non-cognitively impaired control group consisted of 25 individuals without CJD or dementia. MAIN OUTCOME MEASURES: The thymosin ß4 test results in CJD and other dementia. RESULTS: The thymosin ß4 cerebrospinal fluid levels appeared to be markedly increased in CJD samples compared with frontotemporal cases (P = 10(-7)) and patients with Alzheimer disease (P = 10(-7)). A lower significance was observed vs the group with rapid-onset progressive dementia (P = .0004). Thus, at a cutoff value of 1.2% of the thymosin ß4 relative peak area, we estimated 100% sensitivity with 98.5% specificity. CONCLUSION: These findings indicate that cerebrospinal fluid levels of thymosin ß4 protein measured by matrix-assisted laser desorption ionization time-of-flight mass spectrometry may effectively contribute to discriminate CJD from other forms of dementia.

Quantification of thymosin beta(4) in human cerebrospinal fluid using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry.

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) has been applied to the analysis of a wide range of biomolecules. To date, there are two specific areas of application where MALDI-TOF-MS is viewed as impractical: analysis of low-mass analytes and relative quantitative applications. However, these limitations can be overcome and quantification can be routine. Increased levels of thymosin beta(4) (TB4) have been recently found in cerebrospinal fluid (CSF) from Creutzfeldt-Jakob disease (CJD) patients. Our objective was to apply a label-free quantitative application of MALDI-TOF-MS to measure TB4 levels in human CSF by adding the oxidized form of TB4 as an internal standard. The relative peak area or peak height ratios of the native TB4 to the added oxidized form were evaluated. Considering the relative peak area ratios, healthy individuals showed a mean value of 40.8+/-21.27 ng/ml, whereas CJD patients showed high values with a mean of 154+/-59.07 ng/ml, in agreement with the previous observation found in CJD patients. Similar results were obtained considering peak height ratios. The proposed method may provide a simple and rapid screening method for quantification on CSF of TB4 levels suitable for diagnostic purposes.

Thymosin alpha 1 and thymosin beta 4 in serum: comparison of normal, cord, homosexual and AIDS serum.

Thymosin alpha 1 and thymosin beta 4 were first isolated from thymosin fr. 5 and have demonstrated biological activities on the immune system. They are chemically distinct and differ in their immunological activity profiles. The levels of thymosin alpha 1 and thymosin beta 4 were assessed by radioimmunoassay in the same serum samples. Normal thymosin alpha 1 levels were 670 +/- 163 pg/ml for males and 652 +/- 162 pg/ml for females. Normal thymosin beta 4 levels were 974 +/- 400 ng/ml for males and 889 +/- 345 ng/ml for females. No correlation between the levels of the peptides in serum from normal donors was observed. Although many samples of serum from neonates (cord blood), homosexuals and AIDS patients had elevated levels of one or both peptides, no correlation between the two peptides was found. Of potential significance is the observation that while thymosin alpha 1 and beta 4 are elevated in many individuals with AIDS (57 and 48% respectively), the individuals with AIDS related immune dysfunctions had predominantly elevated thymosin alpha 1 (54 vs 15%). These studies suggest that serum levels of the two peptides are modulated separately and that both are of potential value in defining the risk of individuals for developing AIDS.