Proteomic analysis of age-related changes in ovine cerebrospinal fluid

Abstract

Cerebrospinal fluid (CSF) circulates through the brain and has a unique composition reflecting the biological processes of the brain. Identifying ageing CSF biomarkers can aid in understanding the ageing process and interpreting CSF protein changes in neurodegenerative diseases. In this study, ovine CSF proteins from young (1-2 year old), middle aged (3-6 year old) and old (7-10 year old) sheep were systemically studied. CSF proteins were labelled with iTRAQ tagging reagents and fractionated by 2-dimensional high performance, liquid chromatography. Tryptic peptides were identified using MS/MS fragmentation ions for sequencing and quantified from iTRAQ reporter ion intensities at m/z 114, 115, 116 and 117. Two hundred thirty one peptides were detected, from which 143 proteins were identified. There were 52 proteins with >25% increase in concentrations in the old sheep compared to the young. 33 of them increased >25% but <50%, 13 increased >50% but <1 fold, 6 increased >1 fold [i.e. haptoglobin (Hp), haemoglobin, neuroendocrine protein 7B2, IgM, fibrous sheath interacting protein 1, vimentin]. There were 18 proteins with >25% decrease in concentrations in the old sheep compared to the young. 17 of them decreased >25% but <50%, and histone deacetylase 7 (HDAC7) was gradually decreased for over 80%. Glutathione S-transferase was decreased in middle aged CSF compared to both young and old CSF. The differential expressions of 3 proteins (Hp, neuroendocrine protein 7B2, IgM) were confirmed by immunoassays. These data expand our current knowledge regarding ovine CSF proteins, supply the necessary information to understand the ageing process in the brain and provide a basis for diagnosis of neurodegenerative diseases.

Post-Ischaemic Immunological Response in the Brain: Targeting Microglia in Ischaemic Stroke Therapy

“…Regional microglial heterogeneity may have a role in enabling localised homeostatic functions and region-specific sensitivities to microglial dysregulation and involvement in age-related neurodegenerative processes that have neuroinflammatory mechanisms [33,34]. Microglial diversity may be relevant to ischaemic stroke, for which age is a risk factor and neuroinflammation is present [35,36]. Genome-wide transcriptional profiling of microglia from discrete brain regions has found that cerebellar and hippocampal microglia adopt a more immune-vigilant state compared to cortical and striatal regions, and this has been accompanied by relatively greater expression of an extensive set of co-regulated genes involved in energy metabolism.…”

Identification of possible new salivary biomarkers of stress in sheep using a high-resolution quantitative proteomic technique

“…In veterinary science, recent investigations using these novel quantitative technologies to detect possible biomarkers of diagnostic and understand the prognosis of diseases in dogs (Martínez-Subiela et al, 2017;Franco-Martínez et al, 2018) have been reported. Also, studies performed in sheep using these techniques to evaluate the alterations in the intestine associated with under weaning stress using jejunum samples (Cui et al, 2018) or to consider age-related changes in the cerebrospinal fluid (Chen et al, 2018) have been published. However, to the best of our knowledge, no reports currently exist on the use of isobaric tagging technology in saliva samples to detect possible biomarkers of stress in sheep.…”

Stochastic cell renewal process and lengthening of cell cycle

“…This diminution is closely related to the functions of stem cells (SCs) responsible for cell renewal and it is more evident in tissues with a high rate of cell renewal, such as the skin or intestinal epithelium. Some variations in the behavior of SCs with age are known and were studied from different points of view, as genomic [6][7][8], epigenomic [9,10] and proteomic [11][12][13], although the scope and consequences of these changes have not been well established. Nowadays the telomeres shortening as a consequence of semiconservative DNA replications in successive mitosis, is an efficient marker of cell senescence and it leads to an aging theory [14], although there are other alternative theories such as mitochondrial one [15,16].…”

“…1+α)N , • • • , 2(N−s ) (α+1) + (s − 1) s N(N−1) , • • • . (B 13). Taking N = n e , we obtain:P (ne−s ,s ) (0,ne) = 2(n e − s ) (α + 1) + (s − 1) s n e (n e − 1).…”