Decreased myelin basic protein content of the aged human brain

Abstract

Myelin basic protein was extracted from frontal lobe white matter obtained at autopsy from seven individuals ranging in age from 72 to 78 years. Qualitative and quantitative comparisons were made between basic protein from this group and that extracted from another group of individuals ranging in age from 45 to 65 years. The basic protein content of the older brains was considerably lower than that of the younger brains. Qualitative studies that included assay for encephalitogenic activity, disk gel electrophoresis at pH 4.3, and immunoprecipitation did not reveal any difference in the basic protein derived from the two age groups. Possible factors that may help explain the decreased basic protein content of the aged brain are discussed.

The Effect of Age on the Microheterogeneous Pattern of Human Myelin Basic Protein

“…We also observed a decrease in MBP with age, as described by Ansari and Loch [1975], We were able to show that this is mainly the result of a reduction in peak 1 of the heterogeneous pattern (table III). Statisti cally, there is a clear difference only between the youngest and the oldest age groups, not between these and the middle-aged group.…”

“…It is well established that aging in man is accompanied by a reduction in the amount of myelin [Berlet and Volk, 1980] and myelin basic protein (MBP) [Ansari and Loch, 1975], indicating a loss of cellular elements [Brody, 1955;Ordy et al, 1975;Henderson et al, 1980;Anderson et al, 1983], As in other spe cies, human MBP shows microheterogeneity caused by phosphorylation or deamination of certain amino acid residues, so that at least 5 components of differing basicity can be de tected by means of gradient ion exchange chromatography or alkaline electrophoresis [Chou et al" 1976;1978]. Since MBP is reduced in old age, we were interested to see to what extent microheterogeneity is in volved in this process.…”

What’s Behind the Decline? The Role of White Matter in Brain Aging

“…A majority of these older studies indicate no change in the individual protein composition of myelin but were carried out prior to clarification of the myelin proteome [9,100]. Myelin basic protein (MBP) has shown to be decreased in elderly with no cognitive impairment (NCI) [6,97] as well as in AD [77], though in a study of behaviorally characterized rhesus monkeys, MBP, proteolipid protein (PLP), and myelin-associated glycoprotein (MAG) were unchanged while the levels of myelin oligodendrocyte specific protein (MOSP) and 2¢'3'-cyclic nucleotide phosphodiesterase (CNP) were increased with age [86].…”

Test–retest reliability and concurrent validity of in vivo myelin content indices: Myelin water fraction and calibrated T1w/T2w image ratio

“…Myelin, a core component of the central nervous system plays a critical role in ensuring speed and fidelity of neural transmission, efficiency of axonal energy metabolism, maintenance of membranes, formation of synapses and promotion of neuroplasticity [de Hoz and Simons, 2015;Jebelli et al, 2015;Saab et al, 2013]. Myelination of axons is one of the pivotal phenomena of brain development [Ansari and Loch, 1975;Barkovich et al, 1988;Davison and Dobbing, 1966], whereas reduction of myelin content and alteration of its structure have been proposed as neuroanatomic substrates of age-related cognitive declines [Bartzokis, 2004;Lu et al, 2013]. Therefore, valid in vivo evaluation of regional myelin content, reflecting the myelination of axons and reliable measurement of changes therein is a high priority.…”