Betaine - the Dark Knight of the brain

Abstract

The role of betaine in the liver and kidney has been well documented, even from the cellular and molecular point of view. Despite literature reporting positive effects of betaine supplementation in Alzheimer’s, Parkinson’s, and Schizophrenia, the role and function of betaine in the brain are little studied and reviewed. Beneficial effects of betaine in neurodegeneration, excitatory and Inhibitory imbalance, and oxidative stress in the central nervous system have been collected and analyzed with the aim of understanding the main role of betaine in the brain. There are many “dark” aspects needed to complete the picture. The understanding of how this osmolyte is transported across neuron and glial cells is also controversial, as the expression levels and functioning of the known protein capable to transport betaine expressed in the brain, betaine-GABA transporter 1 BGT-1, is itself not well clarified. The reported actions of betaine beyond BGT-1 related to neuronal degeneration and memory impairment are the focus of this work. With this review, we underline the scarcity of detailed molecular and cellular information about betaine action. Consequently, the requirement of detailed focus on and study of the interaction of this molecule with CNS components to sustain the therapeutic use of betaine.

A comparative review on the well-studied GAT1 and the understudied BGT-1 in the brain

“…The electrophysiological measurements, apart from the steady-state currents, also let to record an exponentially decaying transient current, known as the pre-steady state current. They represent the intramembrane charge movement seen as a transient current in response to voltage or Na + concentration jumps and can be recorded by voltage clamp in X. laevis oocytes (Bhatt et al, 2022) and in HEK cells (Bicho and Grewer, 2005). These currents are associated with the initially synchronized out-ofequilibrium events such as binding and release of ions, conformational rearrangements, and charge movements across the membrane electric fields (Wadiche et al, 1995;Peres et al, 2004).…”

The teleost fish PepT1-type peptide transporters and their relationships with neutral and charged substrates

“…The complete open reading frame encoding for Atlantic salmon PepT1a (Gomes et al, 2020) and PepT1b (Rønnestad et al, 2010), zebrafish PepT1a (Vacca et al, 2019) and PepT1b (Verri et al, 2003) were subcloned into pSPORT1 plasmid. Xenopus laevis oocytes were collected under anaesthesia [MS222; 0.10% (w/v) solution in tap water] by laparotomy from adult females and prepared as described in (Bhatt et al, 2022). Xenopus laevis frogs were maintained according to international guidelines (Delpire et al, 2011;McNamara et al, 2018).…”