Taurine: a promising nutraceutic in the prevention of retinal degeneration

Taurine is considered a non-essential amino acid because it is synthesized by most mammals.However,dietary intake of taurine may be necessary to achieve the physiological levels required for the development,maintenance,and function of certain tissues.Taurine may be especially important for the retina.The concentration of taurine in the retina is higher than that in any other tissue in the body and taurine deficiency causes retinal oxidative stress,apoptosis,and degeneration of photoreceptors and retinal ganglion cells.Low plasma taurine levels may also underlie retinal degeneration in humans and therefore,taurine administration could exert retinal neuroprotective effects.Taurine has antioxidant,anti-apoptotic,immunomodulatory,and calcium homeostasis-regulatory properties.This review summarizes the role of taurine in retinal health and disease,where it appears that taurine may be a promising nutraceutical.

Emergence of taurine as a therapeutic agent for neurological disorders

Taurine is a sulfur-containing,semi-essential amino acid that occurs naturally in the body.It alternates between inflammation and oxidative stress-mediated injury in various disease models.As part of its limiting functions,taurine also modulates endoplasmic reticulum stress,Ca^(2+)homeostasis,and neuronal activity at the molecular level.Taurine effectively protects against a number of neurological disorders,including stro ke,epilepsy,cerebral ischemia,memory dysfunction,and spinal cord injury.Although various therapies are available,effective management of these disorders remains a global challenge.Approximately 30 million people are affected worldwide.The design of taurine fo rmation co uld lead to potential drugs/supplements for the health maintenance and treatment of central nervous system disorders.The general neuroprotective effects of taurine and the various possible underlying mechanisms are discussed in this review.This article is a good resource for understanding the general effects of taurine on various diseases.Given the strong evidence for the neuropharmacological efficacy of taurine in various experimental paradigms,it is concluded that this molecule should be considered and further investigated as a potential candidate for neurotherapeutics,with emphasis on mechanism and clinical studies to determine efficacy.

Cysteine dioxygenase and taurine are essential for embryo implantation by involving in E2-ERαand P_(4)-PR signaling in mouse

Background Taurine performs multiple physiological functions,and the maintenance of taurine level for most mammals relies on active uptake from diet and endogenous taurine synthesis through its synthesis enzymes,including cysteine dioxygenase(CDO).In addition,uterus tissue and uterus fluid are rich in to urine,and to urine synthesis is regulated by estrogen(E2)and progesterone(P_(4)),the key hormones priming embryo-uterine crosstalk during embryo implantation,but the functional interactions and mechanisms among which are largely unknown.The present study was thus proposed to identify the effects of CDO and taurine on embryo implantation and related mechanisms by using Cdo knockout(KO)and ovariectomy(OVX)mouse models.Results The uterine CDO expression was assayed from the first day of plugging(d 1)to d 8 and the results showed that CDO expression level increased from d 1 to d 4,followed by a significant decline on d 5 and persisted to d 8,which was highly correlated with serum and uterine taurine levels,and serum P_(4) concentration.Next,Cdo KO mouse was established by CRISPER/Cas9.It was showed that Cdo deletion sharply decreased the taurine levels both in serum and uterus tissue,causing implantation defects and severe subfertility.However,the implantation defects in Cdo KO mice were partly rescued by the taurine supplementation.In addition,Cdo deletion led to a sharp decrease in the expressions of P_(4)receptor(PR)and its responsive genes Ihh,Hoxa10 and Hand2.Although the expression of uterine estrogen receptor(ERa)had no significant change,the levels of ERa induced genes(Muc1,Ltf)during the implantation window were upregulated after Cdo deletion.These accompanied by the suppression of stroma cell proliferation.Meanwhile,E2inhibited CDO expression through ERa and P_(4)upregulated CDO expression through PR.Conclusion The present study firstly demonstrates that taurine and CDO play prominent roles in uterine receptivity and embryo implantation by involving in E2-ERa and P_(4)-PR signaling.These are crucial for our understanding the mechanism of embryo implantation,and infer that taurine is a potential agent for improving reproductive efficiency of livestock industry and reproductive medicine.

Gelatin-based hydrogel functionalized with taurinemoieties for in vivo skin tissue regeneration

Functionalized hydrogels stimulate the migration and morphogenesis of endothelial cells(ECs)and are useful substrates for wound healing.The present study investigates the feasibility of covalent conjugation of taurine(Tau)on a gelatin-based hydrogel.This hydrogel is expected to maintain positive charged growth factors such as basic fibroblast growth factor(bFGF)and vascular endothelial growth factors(VEGFs)near ECs within the hydrogel microenvironment.The gelatin was conjugated with hydroxyl phenol(Ph)and Tau moieties,and in following that Ph residues were crosslinked through a horseradish peroxidase-catalyzed reaction.The migration characteristics of ECs were analyzed by scratch migration assay and microparticle-based cell migration assay.Cellular morphology and amounts of angiopoietin 1(Ang 1),bFGF,and VEGF proteins were evaluated for encapsulated cells.The potential of synthesized hydrogels in wound healing was assessed by the percentage of reduction from the original wound size and histopathological analyses of rat skin.The incorporated Tau molecules within the hydrogel remained stable through covalent bonds during incubation.During extended incubation,the gelatin-based hydrogel conjugated with Tau improved the migration distance and number of existing migrated ECs.Immobilized Tau within the gelatin-based hydrogel induced high motility of ECs,accompanied by robust cytoskeleton extension and a cell subpopulation that expressed CD44 and CD31 receptors as well as enhancement of Ang 1,bFGF,and VEGF.We found that injectable Gel-Ph-Tau effectively improves wound-healing parameters.

Flattening the biological age curve by improving metabolic health:to taurine or not to taurine,that’s the question

The aging population is an important issue around the world especially in developed countries.Although med-ical advances have substantially extended life span,the same cannot be said for the duration of health span.We are seeing in-creasing numbers of elderly people who are frail and/or have multiple chronic conditions;all of these can affect the quality of life of the elderly population as well as increase the burden on the healthcare system.Aging is mechanistically related to common medical conditions such as diabetes mellitus,ischemic heart disease,cognitive decline,and frailty.A recently accepted concept termed‘Accelerated Biological Aging’can be diagnosed when a person’s biological age—as measured by biomarkers of DNA methylation—is older than their corresponding chronological age.Taurine,a conditionally essential amino acid,has received much attention in the past few years.A substantial number of animal studies have provided a strong scientific foundation sug-gesting that this amino acid can improve cellular and metabolic health,including blood glucose control,so much that it has been labelled one of the‘longevity amino acids’.In this review article,we propose the rationale that an adequately powered random-ized-controlled-trial(RCT)is needed to confirm whether taurine can meaningfully improve metabolic and microbiome health,and biological age.This trial should incorporate certain elements in order to provide the much-needed evidence to guide doctors,and also the community at large,to determine whether this promising and inexpensive amino acid is useful in improving human metabolic health.

Taurine牛基因组序列图:反刍动物生物学及其进化论的窗口

为了理解反刍动物的生物学和进化论,牛的基因组图被测定出有大约7倍区域(Genome sevenfold coverage)。整个序列含有最低限度22000个基因,有一套核心基因14345个,是7个哺乳动物种共享拥有的源祖同源基因或直系同源基因(Ortholog),其中有1217个基因在非真哺乳动物亚纲(有袋目动物或单孔目动物)基因组图中不存在或没被检测到。牛染色体特有的进化演变区的片断复制的密度较高,重复元素丰富,并且这种种类特有的基因变异与产乳和免疫反应有关。表达代谢的基因一般是高度保守的,但是人类跟它们同源的5个参与代谢的源祖同源基因已丢失或广泛地发生了漂移。牛的基因组图谱就这样为理解哺乳动物进化和加速家畜泌乳和产肉的遗传改进提供了一种资源。

Natural taurine promotes apoptosis of human hepatic stellate cells in proteomics analysis

AIM:To study the differential expression of proteins between natural taurine treated hepatic stellate cells and controls, and investigate the underlying regulatory mechanism of natural taurine in inhibiting hepatic fibrosis.METHODS: A proteomic strategy combining two-dimensional gel electrophoresis and ultraperform ance liquid chromatographyelectrospray ionizationtandem mass spectrometry (UPLCESIMS/MS) was used to study the differential expression of proteins and Western blotting was used to validate the results. Gene ontology (GO) method was utilized to analyze the functional enrichment of differentially expressed proteins. Flow cytometry was performed to compare the apoptosis rate between taurinetreated and untreated hepatic stellate cells (HSCs).RESULTS: Nineteen differentially expressed proteins (11 upregulated and 8 downregulated) were identifiedby 2D/MS, and the expression profiles of GLO1 and ANXA1 were validated by Western blotting. GO analysis found that these differentially expressed proteins were enriched within biological processes such as "cellular apoptosis", "oxidation reaction" and "metabolic process" in clusters. Flow cytometric analysis showed that taurinetreated HSCs had a significantly increased apoptosis rate when compared with the control group.CONCLUSION: Natural taurine can promote HSC apoptosis so as to inhibit hepatic fibrosis.

Selective depression action of taurine in flotation separation of specularite and chlorite

Chlorite,as the most representative gangue mineral associated with specularite,of which the separation of these two minerals is difficult.This paper investigated the depression effect of taurine on specularite/chlorite separation via flotation experiments,adsorption tests,contact angle measurements,Zeta potential detection,FT-IR measurements,and XPS analyses.The results of single mineral flotation indicated that chlorite could be depressed selectively by taurine with the recovery of less than 30%,but the floatability of specularite remains high with recovery rate of 81.77%at pH 10.The artificial mixed mineral flotation results confirmed the effectiveness of taurine as a depressant.Surface adsorption,contact angle,and Zeta potential detection revealed taurine primarily adsorbs on the chlorite surface,which hampered the DDA’s subsequent adsorption and results in the chlorite’s poor floatability.The FT-IR spectra and XPS analyses provided further proof that taurine adsorbed on chlorite surface as an electron donor,and part of the electrons transferred from the sulfonic acid group of taurine to metal ions during the adsorption process.In addition,the hydrogen bond between amino-group of taurine and O ions in chlorite surface was also formed in the adsorption process.Finally,optimized adsorption configurations of taurine on chlorite surfaces were proposed.

Integrated network analysis of transcriptomic and protein-protein interaction data in taurine-treated hepatic stellate cells

BACKGROUND Studies show that the antifibrotic mechanism of taurine may involve its inhibition of the activation and proliferation of hepatic stellate cells(HSCs). Since the molecular mechanism of taurine-mediated antifibrotic activity has not been fully unveiled and is little studied, it is imperative to use "omics" methods to systematically investigate the molecular mechanism by which taurine inhibits liver fibrosis.AIM To establish a network including transcriptomic and protein-protein interaction data to elucidate the molecular mechanism of taurine-induced HSC apoptosis.METHODS We used microarrays, bioinformatics, protein-protein interaction(PPI) network,and sub-modules to investigate taurine-induced changes in gene expression in human HSCs(LX-2). Subsequently, all of the differentially expressed genes(DEGs) were subjected to gene ontology function and Kyoto encyclopedia of genes and genomes pathway enrichment analysis. Furthermore, the interactions of DEGs were explored in a human PPI network, and sub-modules of the DEGs interaction network were analyzed using Cytoscape software.RESULTS A total of 635 DEGs were identified in taurine-treated HSCs when compared with the controls. Of these, 304 genes were statistically significantly up-regulated, and 331 down-regulated. Most of these DEGs were mainly located on the membrane and extracellular region, and are involved in the biological processes of signal transduction, cell proliferation, positive regulation of extracellular regulated protein kinases 1(ERK1) and ERK2 cascade, extrinsic apoptotic signaling pathway and so on. Fifteen significantly enriched pathways with DEGs were identified, including mitogen-activated protein kinase(MAPK) signaling pathway, peroxisome proliferators-activated receptor signaling pathway,estrogen signaling pathway, Th1 and Th2 cell differentiation, cyclic adenosine monophosphate signaling pathway and so on. By integrating the transcriptomics and human PPI data, nine critical genes, including MMP2, MMP9, MMP21,TIMP3, KLF10, CX3CR1, TGFB1, VEGFB, and EGF, were identified in the PPI network analysis.CONCLUSION Taurine promotes the apoptosis of HSCs via up-regulating TGFB1 and then activating the p38 MAPK-JNK-Caspase9/8/3 pathway. These findings enhance the understanding of the molecular mechanism of taurine-induced HSC apoptosis and provide references for liver disorder therapy.

Protective effects of taurine against muscle damage induced by diquat in 35 days weaned piglets

Background: Oxidative stress is a key factor that influences piglets' health. Taurine plays an imperative role in keeping the biological system from damage. This study was conducted to investigate the protective effect of taurine against muscle injury due to the secondary effect of diquat toxicity.Results: Our study found that taurine effectively and dose-dependently alleviated the diquat toxicity induced rise of feed/gain, with a concurrent improvement of carcass lean percentage. The plasma content of taurine was considerably increased in a dose-dependent manner. Consequently, dietary taurine efficiently improved the activity of plasma antioxidant enzymes. Furthermore, taurine attenuated muscle damage by restoring mitochondrial micromorphology, suppressing protein degradation and reducing the percentage of apoptotic cells in the skeletal muscle. Taurine supplementation also suppressed the genes expression levels of the antioxidant-, mitochondrial biogenesis-, and muscle atrophy-related genes in the skeletal muscle of piglets with oxidative stress.Conclusions: These results showed that the dose of 0.60% taurine supplementation in the diet could attenuate skeletal muscle injury induced by diquat toxicity. It is suggested that taurine could be a potential nutritional intervention strategy to improve growth performance.

Metabolomic profiling for identification of metabolites and relevant pathways for taurine in hepatic stellate cells

AIM To develop a reliable and simple method to identify important biological metabolites and relevant pathways for taurine in hepatic stellate cells(HSCs), in order to provide more data for taurine therapy.METHODS All the biological samples were analyzed by using highperformance liquid chromatography-time electrospray ionization/quadrupole-time of flight mass spectrometry. Principal component analysis and partial least squares discriminant analysis were used to identify statistically different metabolites for taurine in HSCs, and metabolomic pathway analysis was used to do pathway analysis for taurine in HSCs. The chemical structure of the related metabolites and pathways was identified by comparing the m/z ratio and ion mode with the data obtained from free online databases.RESULTS A total of 32 significant differential endogenous metabolites were identified, which may be related to the mechanism of action of taurine in HSCs. Among the seven relevant pathways identified, sphingolipid metabolism pathway, glutathione metabolism pathway and thiamine metabolism pathway were found to be the most important metabolic pathways for taurine in HSCs.CONCLUSION This study showed that there were distinct changes in biological metabolites of taurine in HSCs and three differential metabolic pathways including sphingolipid pathway, glutathione pathway and thiamine metabolism pathway might be of key importance in mediating the mechanism of action of taurine in HSCs.

New solutions for old challenges in glaucoma treatment:is taurine an option to consider?

Glaucoma is a range of progressive optic neuropathies characterized by progressive retinal ganglion cell loss and visual field defects.It is recognized as a leading cause of irreversible blindness affecting more than 70 million people worldwide.Currently,reduction of intraocular pressure,a widely recognized risk factor for glaucoma development,is the only pharmacological strategy for slowing down retinal ganglion cell loss and disease progression.However,retinal ganglion cell death and visual field loss have been observed in normotensive glaucoma,suggesting that the disease process is partially independent of intraocular pressure.Taurine is one of the agents that have attracted attention of researchers recently.Taurine has been shown to be involved in multiple cellular functions,including a central role as a neurotransmitter,as a trophic factor in the central nervous system development,as an osmolyte,as a neuromodulator,and as a neuroprotectant.It also plays a role in the maintenance of the structural integrity of the membranes and in the regulation of calcium transport and homeostasis.Taurine is known to prevent N-methyl-D-aspartic acid-induced excitotoxic injury to retinal ganglion cells.A recently published study clearly demonstrated that taurine prevents retinal neuronal apoptosis both in vivo and in vitro.Protective effect of taurine may be attributed to direct inhibition of apoptosis,an activation of brain derived neurotrophic factor-related neuroprotective mechanisms and reduction of retinal oxidative and nitrosative stresses.Further studies are needed to fully explore the potential of taurine as a neuroprotective agent,so that it can be applied in clinical practice,particularly for the treatment of glaucoma.The objective of current review was to summarize recent evidence on neuroprotective properties of taurine in glaucoma.

Synthesis, Characterization and Thermodecomposition Kinetics of Terbium(Ⅲ) Complex with Novel Schiff Base Salicylaldehyde-Taurine and 1,10-Phenanthroline

A complex of terbium（Ⅲ） with Schiff base salicylaldehyde-taurine and 1,10-phenanthroline was synthesized. The molecular formula was [Tb （sal-taurine） （1,10-phen） （NO3）]·2H2O （sal=salicylaldehyde, 1,10-phen=1,10-phenanthroline）. The composition of the title complex was determined by elemental analysis and EDTA volumetic analysis. IR, Molar conductivity and X-ray powder diffraction were performed for its characterizations. The thermal decomposition kinetics of the complex were investigated under non-isothermal condition using the Achar differential method and the Coats-Redfern integral method. The kinetic equation for the second step corresponds to the mechanisms of the Zhuralev, Lesokin and Templman equation were obtained.

Taurine supplementation in spontaneously hypertensive rats: Advantages and limitations for human applications

Taurine(2-aminoethanesulfonic acid) is a β-amino acid found in many tissues particularly brain, myocardium, and kidney. It plays several physiological roles including cardiac contraction, antioxidation, and blunting of hypertension. Though several lines of evidence indicate that dietary taurine can reduce hypertension in humans and in animal models, evidence that taurine supplementation reduces hypertension in humans has not been conclusive. One reason for the inconclusive nature of past studies may be that taurine having both positive and negative effects on cardiovascular system depending on when it is assessed, some effects may occur early, while others only appear later. Further, other consideration may play a role, e.g., taurine supplementation improves hypertension in spontaneously hypertensive rats on a low salt diet but fails to attenuate hypertension on a high salt diet. In humans, some epidemiologic studies indicate that people with high taurine and low salt diets display lower arterial pressure than those with low taurine and high salt diets. Differences in techniques for measuring arterial pressure, duration of treatment, and animal models likely affect the response in different studies. This review considers both the positive and negative effects of taurine on blood pressure in animal models and their applications for human interventions.

Taurine in semen extender modulates post–thaw semen quality,sperm kinematics and oxidative stress status in mithun(Bos frontalis)spermatozoa

Objective:To assess the effect of taurine on post-thaw semen quality parameters,sperm kinematics,antioxidant and oxidative stress profiles and sperm cholesterol efflux in mithun(Bos frontalis).Methods:A total of 50 ejaculates(n=25 samples)were selected based on biophysical parameters.Each sample was split into four equal aliquots after dilution with the Tris-citrate-glycerol extender.GroupⅠ,Ⅱ,ⅢandⅣcontained 0 mM(the control),25 mM,50 mM and 100 mM of taurine,respectively.Frozen-thawed samples were analysed for motility parameters(progressive forward and in bovine cervical mucus penetration test),kinetic and velocity parameters by computer-assisted sperm analyzer,viability,sperm and nuclear abnormalities,acrosome integrity,plasma membrane and nuclear integrities,sperm enzymatic leakage and biochemical(sperm cholesterol and oxidative stress)profiles.Results:The extender containing 50 mM taurine led to a significant enhancement in viability,acrosomal integrity,plasma membrane integrity,motility(progressive and in cervical mucus),and sperm cholesterol content and notably reduced sperm morphological and nuclear abnormalities,and leakage of intracellular enzymes compared to other taurine treated and untreated control groups(P<0.05).Moreover,in addition to significant improvement in kinetic and velocity profiles,50 mM taurine protected the integrity of acrosome and biochemical membranes than in the untreated control and other taurine treated groups.Inclusion of 50 mM taurine held a clear advantage over the control or 25 mM or 100 mM taurine in cryopreservation of mithun semen.Conclusions:Taurine(50 mM)supplementation in semen extender can be effectively utilized to reduce oxidative stress and improve post-thaw semen quality in mithun.

Effects of Paranosema locustae(Microsporidia) on the development and morphological phase transformation of Locusta migratoria(Orthoptera: Acrididae) through modulation of the neurotransmitter taurine

Neurotransmitters are important in the maintenance of phase transformation of Locusta migratoria(Arthropoda: Orthoptera). Here, the effects of the entomopathogen Paranosema locustae on the neurotransmitter taurine in migratory locusts were studied using biochemical methods. After inoculation with P. locustae, the taurine content of infected locusts significantly declined, but F/C values(ratio between the length of hind femur and the width of the head of locust) increased significantly, compared to healthy locusts. Meanwhile, F/C values of infected locusts that were injected with 2 μg of taurine showed no significant differences from those of healthy locusts, demonstrating that supplemental taurine inhibited the changes in morphological phase caused by P. locustae. Paranosema locustae infection also caused longer developmental durations and lower body weights of locusts, but these changes were unaffected after injection with taurine. These results provided new insights into the mechanisms by which microsporidian parasites affected their locust hosts.

Protection of the rat red cells membrane by taurine in vitro and its mechanism

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Taurine Protects Gut Barrier Function and Prevents Endothelial Cell Injury Induced by Ischaemia-Reperfusion

Purpose: Gut permeability and microvascular injury following ischaemia/reperfusion (IR) have been implicated in the systemic inflammatory response syndrome (SIRS) and multiple organ failure (MOF). Taurine (TAU), a sulfur-containing amino acid, is a powerful antioxidant and regulator of intracellular calcium and several studies have established that treatment with TAU protects cerebral, cardiac and testicular tissue from (IR) injury. This study investigates the protective effect of taurine in an experimental model of I/R-induced gut injury in rats. Methods: Sprague-Dawley rats were randomized into three groups: Control, I/R, TAU + I/R. TAU was given by gavage or intravenous injection before I/R. Ischaemia was induced by cross-clamping superior mesenteric and coeliac vascular pedicle for 20 - 30 min, followed by 60 - 180 min reperfusion. Gut permeability, blood flux, tissue oedema, leucocytes infiltration and eNOS expression were measured at 3 hrs following reperfusion using FD4. Leukocyte-endothelial interactions were determined by intra-vital microscopy during I/R. In vitro studies assessed the protective effect of TAU on endothelial cell function and survival. Results: Treatment with TAU significantly attenuated IR-induced gut hyper permeability, tissue oedema, leukocyte adhesion and infiltration. TAU also prevented the reduction in gut blood flow, leukocyte rolling velocity and eNOS expression induced by IR. TAU protects against I/R-induced endothelial cell injury by reduced anti-oxidant activity and modulation of eNOS expression and intracellular calcium fluxes. Conclusions: TAU protects the gut from intestinal barrier dysfunction induced by surgical I/R.

Study on Preparation Technology of Taurine in Rice Peptide Feed

With rice as experimental material,the multi-strain solid-state fermentation method was used to study the preparation technology of taurine,and the analysis of variance was employed to determine the optimal process of taurine preparation as follows: fermentation time(72h); amount of cysteinyl acid( 2. 5 g),amount of methionine( 2. 5 g); ratio of Bacillus subtilis YS-45 to yeast S-78 to Aspergillus niger PL-39( 1 ∶ 2 ∶ 1). Under the optimal process,the taurine content reached 117. 8 mg/g.