Conversion of brain cytosol profile from fetal to adult type during the perinatal period: Taurine-NAA exchange

Abstract

Mammals face drastic environmental changes at birth. Appropriate adjustments of various systems must take place rapidly to accommodate this once in a life time event. The brain undergoes significant adjustments as well, the most obvious of which is in its need to meet the drastic increase in energy consumption at the neuronal cell membrane due to the explosive increase in neural activities after birth. Actual changes were found to be taken place in two systems, namely, acid base balance control and cytosolic energy transport. The adjustments are accomplished by converting cytosol microenvironment from a taurine rich fetal type environment to an N-acetyl-aspartate (NAA) rich adult type environment during the post-natal period. High concentrations of taurine are necessary to provide effective buffering in the fetal brain, because the fetus cannot utilize the adult type of pCO2 dependent acid–base balance control system, namely respiration driven pCO2 changes. To accommodate the significantly higher demand of energy consumption at the membrane due to the increased neuronal activities, taurine has to be replaced by NAA, since the latter facilitates HEP transport from mitochondria to the membrane by passive diffusion.

Longitudinal investigation of the metabolome of 3D aggregating brain cell cultures at different maturation stages by 1H HR-MAS NMR

“…Glutathione (GSH), PC, and GPC also correlate strongly and positively with Ala, Pro, Thr, Ile, Val, and Leu and on the other hand negatively with myo-inositol (mIno), Cho, Cre, and Glc. The temporal evolution of Tau correlates solely and negatively with NAA, which corresponds to the recent finding of developmental replacement of Tau by NAA [49]. However, besides indicating potential physiological relations between metabolite changes, the correlations may as well be coincidental.…”

Is cancer a severe delayed hypersensitivity reaction and histamine a blueprint?

“…The followings are highlights of comparison in the growth features of fetus and those of cancer cells. Details of data that directly or indirectly support the framework for the present hypotheses are found in examples of the reviews cited in this perspective [4–8, 110–116, 147–190]. During normal fetal growth there is an increased expression of several growth promoting events for orderly growth and development of organs.…”

“…Vasculogenesis or high endothelial venules (HEV) is the earliest events during the fetus growth and development. In early fetal development, the formation of blood vessels are needed for lymphocyte trafficking and development of secondary lymphoid organs in gut's Peyer's patches (also perhaps in lung and conjunctiva or other lymphoid tissues) and for delivery and exchange of nutrients and oxygen to the growing fetus [149–154]. In the process of fetal development HEV are key players in recruiting naïve and memory lymphocytes to lymph nodes (LN) from the blood circulation.…”

“…In the environmentally protected space of fetus growth, there is little need for high energy demands from the mitochondria required for the Yin (tumoricidal) arm of acute inflammation. Absence of expression of pro‐inflammatory mediators and oxidants is perhaps necessary for “one way” growth of fetus tissues because otherwise, as indirectly suggested from clinical and nutritional data, it could result in severe fetal rejection (spontaneous abortion), preterm delivery or other damages to the fetus growth causing alterations in cellular and chromosomal (DNA/RNA mutations or deletion) function during organ development that would lead to premature aging, metabolic diseases or cancers after birth (see below) [149–160, 191–193]. Furthermore, as suggested above the growth features of fetus share the characteristics of lawless cancer cell growth with respect to hypoxic conditions to escape growth‐arrest by programmed cell death (Yin–Yang events), otherwise, the growing fetus would be viewed a foreign entity, like any parasite, to be eliminated (see below).…”

Late post‐natal neurometabolic development in healthy male rats using 1H and 31P magnetic resonance spectroscopy

“…The ethanolamine to choline ratio will influence membrane structure and properties because phosphatidylcholine is preferentially localized on the outer part of phospholipid bilayer and phosphatidylethanolamine is preferentially on the inner part (Deleke, 2007; Harper et al., 2014; Ikeda et al., 2006; Schaffer et al., 1995). Of note, it was sugested based on in vivo and ex vivo 1 H MRS experiments in rats until ~p30 that Tau in fetal brain is the counterpart of NAA in adult brain (Nakada, 2010).…”