Fibronectin is a potential cerebrospinal fluid and serum epilepsy biomarker

Quantitative serum proteome analysis using tandem mass tags in dogs with epilepsy

This study included four groups of dogs (group A: healthy controls, group B: idiopathic epilepsy receiving antiepileptic medication (AEM), group C: idiopathic epilepsy without AEM, group D: structural epilepsy). Comparative quantitative proteomic analysis of serum samples among the groups was the main target of the study. Samples were analyzed by a quantitative Tandem-Mass-Tags approach on the Q-Exactive-Plus Hybrid Quadrupole-Orbitrap mass-spectrometer. Identification and relative quantification were performed in Proteome Discoverer. Data were analyzed using R. Gene ontology terms were analyzed based on Canis lupus familiaris database. Data are available via ProteomeXchange with identifier PXD041129. Eighty-one proteins with different relative adundance were identified in the four groups and 25 were master proteins (p < 0.05). Clusterin (CLU), and apolipoprotein A1 (APOA1) had higher abundance in the three groups of dogs (groups B, C, D) compared to controls. Amine oxidase (AOC3) was higher in abundance in group B compared to groups C and D, and lower in group A. Adiponectin (ADIPOQ) had higher abundance in groups C compared to group A. ADIPOQ and fibronectin (FN1) had higher abundance in group B compared to group C and D. Peroxidase activity assay was used to quantify HP abundance change, validating and correlating with proteomic analysis (r = 0.8796). SIGNIFICANCE: The proteomic analysis of serum samples from epileptic dogs indicated potential markers of epilepsy (CLU), proteins that may contribute to nerve tissue regeneration (APOA1), and contributing factors to epileptogenesis (AOC3). AEM could alter extracellular matrix proteins (FN1). Illness (epilepsy) severity could influence ADIPOQ abundance.

Tandem mass tag-based quantitative proteomic profiling of the serum of patients with abnormal uterine bleeding associated with copper intrauterine device

OBJECTIVE

To investigate changes in the level of protein in serum and uncover the underlying pathogenesis of abnormal uterine bleeding (AUB) associated with copper intrauterine devices (Cu IUD).

METHODS

Protein profiles were investigated via tandem mass tag (TMT)-based quantitative proteomics and bioinformatics technology. Quantification and characterization of candidate proteins were further performed in 33 controls and 45 cases by Luminex assay and enzyme-linked immunosorbent assay.

RESULTS

In total, 842 proteins were identified via TMT coupled with liquid chromatography-tandem mass spectrometry (LC-MS/MS) in the serum of individuals with IUDs. Among them, 25 differentially expressed proteins (p < 0.05) were observed, including eight upregulated proteins and 17 downregulated proteins. Ten proteins were verified, and Alpha-1-Antitrypsin (a1AT) had a significantly elevated expression in women with AUB associated with the Cu IUD compared with healthy controls (p = 0.026) and a high area under the curve value (0.656), as well as sensitivity (64.9%) and specificity (71.9%).

CONCLUSION

This is the first study to explore changes in serum protein and the underlying mechanisms of AUB associated with the Cu IUD via TMT technology. a1AT with biomarker potential was validated. These findings might provide an experimental basis for the early diagnosis or treatment of AUB associated with the Cu IUD.

Protein biomarkers of epileptogenicity after traumatic brain injury

Traumatic brain injury (TBI) is a major risk factor for acquired epilepsy. Post-traumatic epilepsy (PTE) develops over time in up to 50% of patients with severe TBI. PTE is mostly unresponsive to traditional anti-seizure treatments suggesting distinct, injury-induced pathomechanisms in the development of this condition. Moderate and severe TBIs cause significant tissue damage, bleeding, neuron and glia death, as well as axonal, vascular, and metabolic abnormalities. These changes trigger a complex biological response aimed at curtailing the physical damage and restoring homeostasis and functionality. Although a positive correlation exists between the type and severity of TBI and PTE, there is only an incomplete understanding of the time-dependent sequelae of TBI pathobiologies and their role in epileptogenesis. Determining the temporal profile of protein biomarkers in the blood (serum or plasma) and cerebrospinal fluid (CSF) can help to identify pathobiologies underlying the development of PTE, high-risk individuals, and disease modifying therapies. Here we review the pathobiological sequelae of TBI in the context of blood- and CSF-based protein biomarkers, their potential role in epileptogenesis, and discuss future directions aimed at improving the diagnosis and treatment of PTE.

Cerebrospinal fluid markers of extracellular matrix remodelling, synaptic plasticity and neuroinflammation before and after cranial radiotherapy

BACKGROUND

Advances in the treatment of brain tumours have increased the number of long-term survivors, but at the cost of side effects following cranial radiotherapy ranging from neurocognitive deficits to outright tissue necrosis. At present, there are no tools reflecting the molecular mechanisms underlying such side effects, and thus no means to evaluate interventional effects after cranial radiotherapy. Therefore, fluid biomarkers are of great clinical interest.

OBJECTIVE

Cerebrospinal fluid (CSF) levels of proteins involved in inflammatory signalling, synaptic plasticity and extracellular matrix (ECM) integrity were investigated following radiotherapy to the brain.

METHODS

Patients with small-cell lung cancer (SCLC) eligible for prophylactic cranial irradiation (PCI) were asked to participate in the study. PCI was prescribed either as 2 Gy/fraction to a total dose of 30 Gy (limited disease) or 4 Gy/fraction to 20 Gy (extensive disease). CSF was collected by lumbar puncture at baseline, 3 months and 1 year following PCI. Protein concentrations were measured using immunobased assays or mass spectrometry.

RESULTS

The inflammatory markers IL-15, IL-16 and MCP-1/CCL2 were elevated in CSF 3 months following PCI compared to baseline. The plasticity marker GAP-43 was elevated 3 months following PCI, and the same trend was seen for SNAP-25, but not for SYT1. The investigated ECM proteins, brevican and neurocan, showed a decline following PCI. There was a strong correlation between the progressive decline of soluble APPα and brevican levels.

CONCLUSION

To our knowledge, this is the first time ECM-related proteins have been shown to be affected by cranial radiotherapy in patients with cancer. These findings may help us to get a better understanding of the mechanisms behind side effects following radiotherapy.

SPR imaging biosensor for the quantitation of fibronectin concentration in blood samples

The purpose of this study was presentation of a new biosensor capable of determination of fibronectin. This biosensor was based on the specific interaction of anti-fibronectin antibody produced in rabbit with fibronectin. The surface plasmon resonance imaging (SPRI) technique was used as a detecting method. Optimization and characterization properties of the biosensor were studied. The determination of fibronectin concentration in natural samples was done. The results were compared with a reference method (Enzyme-Linked Immunosorbent Assay-ELISA). The analytically useful dynamic response range of biosensor is between 5 and 400ngmL^-1. The detection limit is 1.5ngmL^-1 and limit quantification is 5ngmL^-1. The proposed SPRI biosensor showed good selectivity for potential interferences. It was applied to determine fibronectin concentrations in plasma of healthy donors and of patients after thermal injury. Good correlations between results obtained using the SPRI biosensor and ELISA test (correlation coefficients for healthy donors 0.996, for patients 0.984) were obtained. The average fibronectin concentration of healthy donors was 140.5±24.6μgmL ^-1 and the average fibronectin concentration of patients was 601.5±72.1μgmL ^-1, which was in agreement with results obtained by other investigators. The obtained results indicate that the developed biosensor may be a candidate for monitoring fibronectin concentration in blood samples.