TAURINE

Taurine, 2-aminoethanesulfonic acid, is the second most abundant endogenous amino acid after glutamate in the CNS. The chemical plays multiple roles in the body, including thermoregulation, stabilization of protein folding, anti-inflammation, antioxidation, osmoregulation, calcium homeostasis and CNS development. Previous reports in the literature have revealed a lack of taurine in the brains of Alzheimer’s Disease (AD) patients. Arai et al. reported that postmortem brain tissues of AD patients have low concentrations of taurine in the temporal cortex compared with control patients’ brain tissues. Multiple lines of evidence suggest taurine as a therapeutic agent for AD. Recently, taurine was reported to help improve cognitive function and protect against neuropathology in an animal model of AD. Jakaria et al. reported that taurine displayed therapeutic potential against neurological disorders, including AD. Santa-Maria et al. reported that taurine binds to Aβ plaques with weak antifibrillogenic effects. In addition, intravenously administered taurine prevents Aβ neurotoxicity and cognitive impairment. To date, no reports of the possible side effects of taurine have been documented, and due to its nontoxic properties in the body, taurine has been used in foods. Biologically, taurine plays several crucial roles in the modulation of calcium signaling, osmoregulation, and membrane stabilization. The sulfonic acid group in taurine has been reported to bind to Aβ and prevent glycosaminoglycans (GAGs) from binding to Aβ. In AD patients, amyloid peptide binds to GAGs, causing plaques to accumulate in the brain and destroy neurons. Another clinical study reported that 3-amino-1-propane sulfonic acid (3-APS) was designed as an anti-amyloid therapy and significantly reduces Aβ in the brain. Taurine has structural similarity to 3-APS; therefore, we postulated that taurine would eventually bind Aβ directly to inhibit the interaction of GAGs with amyloid peptide. This series of events is thought to eventually led to downregulation of mGluR5. Many studies in rodents also have demonstrated the effects of taurine on AD. Kim et al. reported that taurine significantly ameliorated hippocampus-related cognitive deficits in an AD mouse model. In another recent study, taurine was reported to bind directly to AβO and consequently ameliorated the behavioral deficiencies of AD, such as the loss of learning and memory. Roberto et al. reported that taurine strongly protected neurons against the neurotoxicity of Aβ in vitro. Thy also demonstrated that taurine prevented neurotoxicity caused by Aβ and glutamate receptor agonists in an in vitro study. However, the studies referenced above were all performed based on ex vivo or behavioral observations rather than changes at the molecular level. The progression of AD begins preferentially with a change at the molecular level, and then clinical symptoms appear due to functional and structural changes in the brain. The novelty of the present study is that the therapeutic effects of taurine on AD were evaluated via functional PET.

PUBLISHED ARTICLES :

** Sci Rep. 2020 Sep 23;10(1):15551.doi: 10.1038/s41598-020-72755-4.

Evaluation of the neuroprotective effect of taurine in Alzheimer's disease using functional molecular imaging

** J Immunol Res. 2021 Jul 5;2021:7497185.doi: 10.1155/2021/7497185. eCollection 2021.

Neuroprotective Effect of Taurine against Cell Death, Glial Changes, and Neuronal Loss in the Cerebellum of Rats Exposed to Chronic-Recurrent Neuroinflammation Induced by LPS

** Mol Med Rep. 2018 Nov;18(5):4516-4522.doi: 10.3892/mmr.2018.9465. Epub 2018 Sep 6.

Protective effects of taurine against inflammation, apoptosis, and oxidative stress in brain injury

** Redox Biol. 2019 Jun;24:101223.doi: 10.1016/j.redox.2019.101223. Epub 2019 May 21.

Taurine and its analogs in neurological disorders: Focus on therapeutic potential and molecular mechanisms

** Sci Rep. 2014 Dec 12;4:7467.doi: 10.1038/srep07467.

Taurine in drinking water recovers learning and memory in the adult APP/PS1 mouse model of Alzheimer's disease

** Stem Cell Res. 2015 May;14(3):369-79.doi: 10.1016/j.scr.2015.04.001. Epub 2015 Apr 10.

Taurine increases hippocampal neurogenesis in aging mice

** Nutr J. 2021 Jun 8;20(1):53.doi: 10.1186/s12937-021-00712-6.

The effects of Taurine supplementation on inflammatory markers and clinical outcomes in patients with traumatic brain injury: a double-blind randomized controlled trial