Minocycline Effects on the Cerebrospinal Fluid Proteome of Experimental Autoimmune Encephalomyelitis Rats

Abstract

To identify response biomarkers for pharmaceutical treatment of multiple sclerosis, we induced experimental autoimmune encephalomyelitis (EAE) in rats and treated symptomatic animals with minocycline. Cerebrospinal fluid (CSF) samples were collected 14 days after EAE induction at the peak of neurological symptoms, and proteomics analysis was performed using nano-LC-Orbitrap mass spectrometry. Additionally, the minocycline concentration in CSF was determined using quantitative matrix-assisted laser desorption/ionization-triple-quadrupole tandem mass spectrometry (MALDI-MS/MS) in the selected reaction monitoring (SRM) mode. Fifty percent of the minocycline-treated EAE animals did not show neurological symptoms on day 14 ("responders"), while the other half displayed neurological symptoms ("nonresponders"), indicating that minocycline delayed disease onset and attenuated disease severity in some, but not all, animals. Neither CSF nor plasma minocycline concentrations correlated with the onset of symptoms or disease severity. Analysis of the proteomics data resulted in a list of 20 differentially abundant proteins between the untreated animals and the responder group of animals. Two of these proteins, complement C3 and carboxypeptidase B2, were validated by quantitative LC-MS/MS in the SRM mode. Differences in the CSF proteome between untreated EAE animals and minocycline-treated responders were similar to the differences between minocycline-treated responders and nonresponders (70% overlap). Six proteins that remained unchanged in the minocycline-treated animals but were elevated in untreated EAE animals may be related to the mechanism of action of minocycline.

Minocycline in neurodegenerative and psychiatric diseases: An update

“…Subsequently, a reduction in neuroinflammation, demyelination and axonal damage [85,86], a decrease in apoptosis and glutamatergic excitotoxicity [87], a reduction of brain lesions observed by magnetic resonance imaging (MRI) [88] and an increment of brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF) neurotrophins were also reported [89]. Finally, in 2012, another preclinical study was conducted, corroborating the previous results, but emphasizing that these effects were observed in just half of the animals, and suggesting that minocycline may not be able to block the disease progression but to prevent the disease in some subjects [90]. However, this effect was not observed at 24 months [95].…”

Differential tissue expression of extracellular vesicle‐derived proteins in prostate cancer

“…Label‐free quantitation was performed using Progenesis LC‐MS Software (version 3.0; Nonlinear Dynamics Ltd., Newcastle‐upon‐Tyne, UK) following our previously reported methodology . To get quantitative data, we selected only proteins identified by three or more peptides for statistical analysis of protein abundance between groups.…”

Microscale depletion of high abundance proteins in human biofluids using IgY14 immunoaffinity resin: analysis of human plasma and cerebrospinal fluid

“…Because of the greatly decreased protein concentration of this biofluid, the application of immunoaffinity depletion to this sample type has been largely limited to large samples (>1 mL) [32, 41, 46]. In studies with smaller mammals, such as mice where <100 μL of CSF can be obtained [47], immunoaffinity methods become unworkable. The aim in future research is to combine our microscale depletion column with highly sensitive online sample handling approaches [48, 49], permitting reproducible, in-depth proteomic analysis for these limited samples.…”

“…The results obtained in our study compare well with reports in the literature that utilize larger sample volumes. A summary table of literature results for recent CSF studies for comparison is given in Electronic Supplementary Material Table S1 [32, 41, 46, 47, 50–54]. For instance, Borg et al identified 156 proteins with 750 μg of CSF sample of a pool from 5 patients using IgY 14 and also identified 535 proteins with the same amount of CSF sample using IgY HAS RP30, in which BEH130 TM C18 analytical column and LTQ-FT Ultra mass spectrometer were used for a mass spectrometry [41].…”