The effect of taurine on chronic heart failure: actions of taurine against catecholamine and angiotensin II

Targeted metabolomic analysis of serum amino acids in heart failure patients

Heart failure (HF) has been recognized as a global epidemic with high rates of morbidity, hospitalization, and mortality. The role of amino acids, which provide the body with energy, in the development of HF is still unclear. The aim of this study was to explore changes in serum amino acids in patients with HF and identify potential biomarkers. First, the serum amino acid metabolism profiles of 44 patients with HF and 30 healthy controls (Con) were quantitatively measured. Then, candidate markers were identified through the utilization of T test, multivariate statistical analysis, and receiver operating characteristic (ROC) curve analysis. The results found that there were 11 amino acid levels that were significantly different between patients with HF and Con. Based on ROC curve analysis, the biomarkers of eight amino acids (Glutamic acid, Taurine, L-aspartic acid, L-ornithine, Ethanolamine, L-Serine, L-Sarcosine, and Cysteine) showed high sensitivity and specificity (AUC > 0.90), and binary logistic regression analysis was used in MetaboAnalyst 5.0. Among the amino acids examined, six exhibited notable alterations in accordance with the severity of HF. In conclusion, this study cannot only provide clinicians with an objective diagnostic approach for the early identification of HF, but also enhances comprehension of the underlying mechanisms involved in the pathogenesis of HF.

Taurine deficiency associated with dilated cardiomyopathy and aging

Taurine (2-aminoethanesulfonic acid) is a free amino acid found ubiquitously and abundantly in mammalian tissues. Taurine content in the heart is approximately 20 mM, which is approximately 100 times higher than plasma concentration. The high intracellular concentration of taurine is maintained by the taurine transporter (TauT; Slc6a6). Taurine plays various roles, including the regulation of intracellular ion dynamics, calcium handling, and acting as an antioxidant in the heart. Some species, such as cats and foxes, have low taurine biosynthetic capacity, and dietary taurine deficiency can lead to disorders such as dilated cardiomyopathy and blindness. In humans, the relationship between dietary taurine deficiency and cardiomyopathy is not yet clear, but a genetic mutation related to the taurine transporter has been reported to be associated with dilated cardiomyopathy. On the other hand, many studies have shown an association between dietary taurine intake and age-related diseases. Notably, it has recently been reported that taurine declines with age and is associated with lifespan in worms and mice, as well as healthspan in mice and monkeys. In this review, we summarize the role of dietary and genetic taurine deficiency in the development of cardiomyopathy and aging.

DILATED CARDIOMYOPATHY IN SLENDER-TAILED MEERKATS (SURICATA SURICATTA) UNDER HUMAN CARE

Meerkats (Suricata suricatta) housed at two accredited zoological institutions in the United States were evaluated via echocardiography, thoracic radiography, and blood biomarkers-taurine and feline N-terminal pro-B-type natriuretic peptide-to determine the prevalence and severity of dilated cardiomyopathy (DCM) in both populations. In total, 24 meerkats were evaluated and 7 were diagnosed with DCM based on the following parameters: left ventricular internal diameter at end diastole > 1.30 cm, left ventricular internal diameter at end systole > 1.10 cm, and a fractional shortening of <18%. Echocardiographic parameters were identified and reported for normal and affected meerkats, whereas thoracic radiographs were not useful for screening for DCM. Meerkats with DCM were treated with pimobendan and/or benazepril and furosemide if indicated. Seven meerkats died during the study period, with the majority exhibiting myocardial fibrosis. Of the blood parameters tested, elevated taurine levels were associated with DCM. Further research is necessary to characterize the etiology of DCM in meerkats.

Unraveling the Role of miR-200b-3p in Attention-Deficit/Hyperactivity Disorder (ADHD) and Its Therapeutic Potential in Spontaneously Hypertensive Rats (SHR)

Attention-deficit/hyperactivity disorder (ADHD) is a prevalent neurodevelopmental disorder in children with unknown etiology. Impaired learning ability was commonly reported in ADHD patients and has been associated with dopamine uptake in the striatum of an animal model. Another evidence also indicated that micro-RNA (miR)-200b-3p is associated with learning ability in various animal models. However, the association between miR-200b-3p and ADHD-related symptoms remains unclear. Therefore, the current study investigated the role of miR-200b-3p in ADHD-related symptoms such as inattention and striatal inflammatory cytokines. To verify the influence of miR-200b-3p in ADHD-related symptoms, striatal stereotaxic injection of miR-200b-3p antagomir (AT) was performed on spontaneously hypertensive rats (SHR). The antioxidant activity and expressions of miR-200b-3p, slit guidance ligand 2 (Slit2), and inflammatory cytokines in the striatum of SHR were measured using quantitative real-time polymerase chain reaction (RT-qPCR), immunohistochemistry (IHC), immunoblotting, and enzyme-linked immunosorbent assay (ELISA). The spontaneous alternation of SHR was tested using a three-arm Y-shaped maze. The administration of miR-200b-3p AT or taurine significantly decreased striatal tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-6 in SHR, along with increased super-oxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities and significantly higher spontaneous alternation. In this paper, we show that miR-200b-3p AT and taurine alleviates ADHD-related symptoms in SHR. These findings provide insights into ADHD's molecular basis and suggest miR-200b-3p as a potential therapeutic target. Concurrently, this study also suggests broad implications for treating neurodevelopmental disorders affecting learning activity such as ADHD.

Inhibition of OAT1/3 and CMPF uptake attenuates myocardial ischemia-induced chronic heart failure via decreasing fatty acid oxidation and the therapeutic effects of ruscogenin

Chronic heart failure (CHF) as a long-term disease is highly prevalent in elder people worldwide. Early diagnosis and treatments are crucial for preventing the development of CHF. Herein, we aimed to identify novel diagnostic biomarker, therapeutic target and drug for CHF. Untargeted metabolomic analysis has been used to characterize the different metabolomic profile between CHF patients and healthy people. Meanwhile, the targeted metabolomic study demonstrated the elevation of 3-carboxy-4-methyl-5-propyl-2-furanpropanoic acid (CMPF) in the serum of CHF patients and coronary artery ligation-induced CHF mice. Subsequently, we firstly observed that elevation of CMPF impaired cardiac function and aggravated myocardial injury by enhancing fatty acid oxidation (FAO). Interestingly, inhibition of responsible transporters organic anion transporter 1/3 (OAT1/3) has been found to decrease the CMPF level, and suppress FAO-related key protein expressions including peroxisome proliferator-activated receptor alpha, peroxisome proliferative activated receptor-α, carnitine palmitoyl transferase 1, and malonyl CoA decarboxylase in coronary artery ligation-induced CHF mice. Meanwhile, the inhibitor of OAT1/3 presented an excellent improvement in cardiac function and histological injury. Based on the above findings, molecular docking was adopted to screen the potential therapeutic drug targeting OAT1/3, and ruscogenin (RUS) exhibited a great binding affinity with OAT1 and OAT3. Next, it was verified that RUS could remarkedly decrease the expression of OAT1/3 and CMPF levels in heart tissue of CHF mice, as well as suppress the expression of FAO-related proteins. What's more, RUS can effectively improve cardiac function, myocardial fibrosis and morphological damage. Collectively, this study provided a potential metabolic marker CMPF and novel target OAT1/3 for CHF, which were demonstrated to be involved in FAO. And RUS was identified as a potential anti-FAO drug for CHF by regulating OAT1/3.

Beyond Angiotensin-Converting Enzyme Inhibitors: Modulation of the Renin-Angiotensin-Aldosterone System to Delay or Manage Congestive Heart Failure

The renin-angiotensin-aldosterone system (RAAS) consists of bioactive angiotensin peptides, enzymatic pathways, receptors, and the steroid hormone aldosterone. The RAAS regulates blood pressure, sodium, and electrolyte homeostasis and mediates pathologic disease processes. Within this system is an alternative arm that counterbalances the vasoconstrictive, sodium and water retentive, and pro-fibrotic and inflammatory effects of the classical arm. Improved biochemical methodologies in RAAS quantification are elucidating how this complex system changes in health and disease. Future treatments for cardiovascular and kidney disease will likely involve a more nuanced manipulation of this system rather than simple blockade.

Bibliometric and Visual Analysis of Global Research on Taurine, Creatine, Carnosine, and Anserine with Metabolic Syndrome: From 1992 to 2022

Red meat and animal-sourced protein are often disparaged as risk factors for developing metabolic syndrome, while emerging research has shown the beneficial effects of dietary taurine, creatine, carnosine, and anserine which are all exclusively abundant in red meat. Thus, it is imperative to highlight the available evidence to help promote red meat as part of a well-balanced diet to optimize human health. In this study, a bibliometric analysis was conducted to investigate the current research status of dietary taurine, creatine, carnosine, and anserine with metabolic syndrome, identify research hotspots, and delineate developmental trends by utilizing the visualization software CiteSpace. A total of 1094 publications were retrieved via the Web of Science Core Collection from 1992 to 2022. There exists a gradual increase in the number of publications on this topic, but there is still much room for research papers to rise. The United States has participated in the most studies, followed by China and Japan. The University of Sao Paulo was the research institute contributing the most; Kyung Ja Chang and Sanya Roysommuti have been identified as the most prolific authors. The analysis of keywords reveals that obesity, lipid profiles, blood pressure, and glucose metabolism, as well as ergogenic aid and growth promoter have been the research hotspots. Inflammation and diabetic nephropathy will likely be frontiers of future research related to dietary taurine, creatine, carnosine, and anserine. Overall, this paper may provide insights for researchers to further delve into this field and enlist the greater community to re-evaluate the health effects of red meat.

The effect of taurine supplementation on the renin-angiotensin-aldosterone system of dogs with congestive heart failure

The role of taurine in the treatment of congestive heart failure (CHF) in dogs without systemic deficiency is unexplored. Taurine might have beneficial cardiac effects aside from deficit replacement. We hypothesized that oral taurine supplementation administered to dogs with naturally-occurring CHF would suppress the renin-angiotensin aldosterone system (RAAS). Oral taurine was administered to 14 dogs with stable CHF. Serum biochemical variables, blood taurine concentrations, and comprehensive analysis of RAAS variables were compared before and 2 weeks after taurine supplementation added to background furosemide and pimobendan therapy for CHF. Whole blood taurine concentrations increased after supplementation (median 408 nMol/mL, range 248-608 before and median 493 nMol/mL, range 396-690 after; P = .006). Aldosterone to angiotensin II ratio (AA2) was significantly decreased after taurine supplementation (median 1.00, range 0.03-7.05 before and median 0.65, range 0.01-3.63 after; P = .009), but no other RAAS components significantly differed between timepoints. A subset of dogs showed marked decreases in RAAS metabolites after supplementation and these dogs were more likely to have been recently hospitalized for CHF treatment than dogs that did not show marked decreases in classical RAAS metabolites. Overall, taurine only lowered AA2 in this group of dogs, however, response heterogeneity was noted, with some dogs showing RAAS suppression.

Earth Worming-An Evaluation of Earthworm (Eisenia andrei) as an Alternative Food Source

Aside from their bioremediation roles, little is known about the food and feed value of earthworms. In this study, a comprehensive evaluation of the nutritional composition (proximate analysis and profiles of fatty acids and minerals) and techno-functional properties (foaming and emulsion stability and capacity) of earthworm (Eisenia andrei, sourced in New Zealand) powder (EAP) were investigated. Lipid nutritional indices, ω6/ω3, atherogenicity index, thrombogenicity index, hypocholesterolemic/hypercholesterolemic acid ratio, and health-promoting index of EAP lipids are also reported. The protein, fat, and carbohydrate contents of EAP were found to be 53.75%, 19.30%, and 23.26% DW, respectively. The mineral profile obtained for the EAP consisted of 11 essential minerals, 23 non-essential minerals, and 4 heavy metals. The most abundant essential minerals were potassium (8220 mg·kg^-1 DW), phosphorus (8220 mg·kg^-1 DW), magnesium (744.7 mg·kg^-1 DW), calcium (2396.7 mg·kg^-1 DW), iron (244.7 mg·kg^-1 DW), and manganese (25.6 mg·kg^-1 DW). Toxic metals such as vanadium (0.2 mg·kg^-1 DW), lead (0.2 mg·kg^-1 DW), cadmium (2.2 mg·kg^-1 DW), and arsenic (2.3 mg·kg^-1 DW) were found in EAP, which pose safety considerations. Lauric acid (20.3% FA), myristoleic acid (11.20% FA), and linoleic acid (7.96% FA) were the most abundant saturated, monounsaturated, and polyunsaturated fatty acids, respectively. The lipid nutritional indices, such as IT and ω-6/ω-3, of E. andrei were within limits considered to enhance human health. A protein extract derived from EAP (EAPPE), obtained by alkaline solubilisation and pH precipitation, exhibited an isoelectric pH of ~5. The total essential amino acid content and essential amino acid index of EAPPE were 373.3 mg·g^-1 and 1.36 mg·g^-1 protein, respectively. Techno-functional analysis of EAPPE indicated a high foaming capacity (83.3%) and emulsion stability (88.8% after 60 min). Heat coagulation of EAPPE was greater at pH 7.0 (12.6%) compared with pH 5.0 (4.83%), corroborating the pH-solubility profile and relatively high surface hydrophobicity (1061.0). These findings demonstrate the potential of EAP and EAPPE as nutrient-rich and functional ingredients suitable as alternative food and feed material. The presence of heavy metals, however, should be carefully considered.

N-Chlorotaurine Reduces the Lung and Systemic Inflammation in LPS-Induced Pneumonia in High Fat Diet-Induced Obese Mice

Lung infection can evoke pulmonary and systemic inflammation, which is associated with systemic severe symptoms, such as skeletal muscle wasting. While N-chlorotaurine (also known as taurine chloramine; TauCl) has anti-inflammatory effects in cells, its effects against pulmonary and systemic inflammation after lung infection has not been elucidated. In the present study, we evaluated the anti-inflammatory effect of the taurine derivative, TauCl against Escherichia coli-derived lipopolysaccharide (LPS)-induced pneumonia in obese mice maintained on a high fat diet. In this study, TauCl was injected intraperitoneally 1 h before intratracheal LPS administration. While body weight was decreased by 7.5% after LPS administration, TauCl treatment suppressed body weight loss. TauCl also attenuated the increase in lung weight due to lung edema. While LPS-induced acute pneumonia caused an increase in cytokine/chemokine mRNA expression, including that of IL-1β, -6, TNF-α, MCP-1, TauCl treatment attenuated IL-6, and TNF-alpha expression, but not IL-1β and MCP-1. TauCl treatment partly attenuated the elevation of the serum cytokines. Furthermore, TauCl treatment alleviated skeletal muscle wasting. Importantly, LPS-induced expression of Atrogin-1, MuRF1 and IκB, direct or indirect targets for NFκB, were suppressed by TauCl treatment. These findings suggest that intraperitoneal TauCl treatment attenuates acute pneumonia-related pulmonary and systemic inflammation, including muscle wasting, in vivo.

Taurine and Its Derivatives: Analysis of the Inhibitory Effect on Platelet Function and Their Antithrombotic Potential

Taurine is a semi-essential, the most abundant free amino acid in the human body, with a six times higher concentration in platelets than any other amino acid. It is highly beneficial for the organism, has many therapeutic actions, and is currently approved for heart failure treatment in Japan. Taurine has been repeatedly reported to elicit an inhibitory action on platelet activation and aggregation, sustained by in vivo, ex vivo, and in vitro animal and human studies. Taurine showed effectiveness in several pathologies involving thrombotic diathesis, such as diabetes, traumatic brain injury, acute ischemic stroke, and others. As human prospective studies on thrombosis outcome are very difficult to carry out, there is an obvious need to validate existing findings, and bring new compelling data about the mechanisms underlying taurine and derivatives antiplatelet action and their antithrombotic potential. Chloramine derivatives of taurine proved a higher stability and pronounced selectivity for platelet receptors, raising the assumption that they could represent future potential antithrombotic agents. Considering that taurine and its analogues display permissible side effects, along with the need of finding new, alternative antithrombotic drugs with minimal side effects and long-term action, the potential clinical relevance of this fascinating nutrient and its derivatives requires further consideration.

Shexiang Tongxin Dropping Pill Protects Against Chronic Heart Failure in Mice via Inhibiting the ERK/MAPK and TGF-β Signaling Pathways

Background: Chronic heart failure (CHF) is a major public health problem with high mortality and morbidity worldwide. Shexiang Tongxin Dropping Pill (STDP) is a widely used traditional Chinese medicine preparation for coronary heart disease and growing evidence proves that STDP exerts beneficial effects on CHF in the clinic. However, the molecular mechanism of the therapeutic effects of STDP on CHF remains largely unknown.

Objective: This study aimed to elucidate the mechanism of action of STDP against CHF by integrating network pharmacology analysis and whole-transcriptome sequencing.

Methods: First, the mouse model of CHF was established by the transverse aortic constriction (TAC) surgery, and the efficacy of STDP against CHF was evaluated by assessing the alterations in cardiac function, myocardial fibrosis, and cardiomyocyte hypertrophy with echocardiography, Masson’s trichrome staining, and wheat germ agglutinin staining. Next, a CHF disease network was constructed by integrating cardiovascular disease-related genes and the transcriptome sequencing data, which was used to explore the underlying mechanism of action of STDP. Then, the key targets involved in the effects of STDP on CHF were determined by network analysis algorithms, and pathway enrichment analysis was performed to these key genes. Finally, important targets in critical pathway were verified in vivo.

Results: STDP administration obviously improved cardiac function, relieved cardiomyocyte hypertrophy, and ameliorated myocardial fibrosis in CHF mice. Moreover, STDP significantly reversed the imbalanced genes that belong to the disease network of CHF in mice with TAC, and the number of genes with the reverse effect was 395. Pathway analysis of the crucial genes with recovery efficiency revealed that pathways related to fibrosis and energy metabolism were highly enriched, while TGF-β pathway and ERK/MAPK pathway were predicted to be significantly affected. Consistently, validation experiments confirmed that inhibiting ERK/MAPK and TGF-β signaling pathways via reduction of the phosphorylation level of Smad3 and ERK1/2 is the important mechanism of STDP against CHF.

Conclusion: Our data demonstrated that STDP can recover the imbalanced CHF network disturbed by the modeling of TAC through the multi-target and multi-pathway manner in mice, and the mechanisms are mainly related to inhibition of ERK/MAPK and TGF-β signaling pathways.

Taurine alleviates kidney injury in a thioacetamide rat model by mediating Nrf2/HO-1, NQO-1 and MAPK/ NF-κB signaling pathways

This study aimed to investigate the molecular mechanisms by which taurine exerts its reno-protective effects in thioacetamide (TAA)-induced kidney injury in rats. Rats received taurine (100 mg/kg daily, intraperitoneally) either from day 1 of TAA injection (250 mg/kg twice weekly for 6 weeks) or after 6 weeks of TAA administration. Taurine treatment, either concomitant or later as a therapy, restored kidney functions, reduced BUN, creatinine, MDA, and increased renal levels of SOD and reversed the increase of KIM-1 and NGAL caused by TAA. Taurine treatment also led to a significant rise in Nrf2, HO-1, and NQO-1 levels, with significant suppression of ERK 1/2, NF-κB, and TNFα gene expressions, and IL-18 and TNFα protein levels compared to those in TAA kidney-injured rats. Taurine exhibited reno-protective potential in TAA-induced kidney injury through its anti-oxidant and anti-inflammatory effects. Taurine anti-oxidant activity is accredited to its effect on Nrf-2 induction and subsequent activation of HO-1 and NQO-1. In addition, taurine exerts its anti-inflammatory effect via regulating NF-κB transcription and subsequent production of pro-inflammatory mediators via MAPK signaling regulation.

Metagenomic analysis revealed the individualized shift in ileal microbiome of neonatal calves in response to delaying the first colostrum feeding

The aim of this study was to explore the effect of colostrum feeding time on the ileal microbiome of neonatal calves. In this study, 22 male Holstein calves were randomly assigned to different colostrum feeding time treatments: after birth (at 45 min, n = 7); at 6 h after birth (n = 8); and at 12 h after birth (TRT12h; n = 7). At 51 h after birth, calves were killed and ileum digesta was collected for microbiome analysis using shotgun metagenomic sequencing. Bacteria, archaea, eukaryotes, and viruses were identified from the ileum microbiome. For the bacteriome, Firmicutes and Proteobacteria were the predominant phyla, and Escherichia, Streptococcus, Lactobacillus were the 3 most abundant genera. For the archaeal community, Euryarchaeota and Crenarchaeota were the 2 major phyla, and Methanosarcina, Methanobrevibacter, and Methanocorpusculum were the 3 most abundant genera. In total, 116 Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways were identified from the ileal microbiome, with "biosynthesis of vancomycin group antibiotics," "biosynthesis of ansamycins," "valine, leucine, and isoleucine biosynthesis," "ribosome," and "d-alanine metabolism" as the top 5 functions. When the ileal microbiomes were compared among the 3 treatments, the relative abundance of Enterococcus was higher in TRT12h calves, suggesting that calves may have a higher abundance of opportunistic pathogens when the feeding of colostrum is delayed for 12 h. Moreover, among all KEGG pathways, the enriched "taurine and hypotaurine metabolism" (KO00430) pathway was identified in the ileal microbiome of TRT12h calves; however, future studies are needed to understand the effect on the host. Additionally, 2 distinct ileal microbial profiles were identified across all samples, indicating that that host factors may play a significant role in driving varied microbiome changes in response to colostrum feeding time. Whether such microbiome shifts affect long-term gut function and calf performance warrants future studies.

HPLC-QTOF/MS-based metabolomics to explore the molecular mechanisms of Yiqi Fumai Lyophilized Injection in heart failure mice

Chronic heart failure is a common and fatal disease triggered by loss of normal cardiac function. Yiqi Fumai Lyophilized Injection is widely used in the treatment of cardiovascular diseases, especially chronic heart failure. In this study, a model of chronic heart failure in mice was established with permanent coronary artery ligation followed by Yiqi Fumai Lyophilized Injection intervention for 14 days. Then, the endogenous metabolites of mice plasma and urine samples were screened through nontargeted metabolomics techniques. The results indicated that Yiqi Fumai Lyophilized Injection treatment changed the metabolic pattern of chronic heart failure and regulated valine, leucine, and isoleucine biosynthesis, taurine and hypotaurine metabolism, histidine metabolism and arginine biosynthesis, etc. Finally, the cardioprotective mechanism of Yiqi Fumai Lyophilized Injection was further verified in the mouse model of chronic heart failure and angiotensin II-induced cardiac fibroblasts based on metabolomics. The results showed that Yiqi Fumai Lyophilized Injection could inhibit myocardial fibrosis to improve chronic heart failure. This study firstly elucidated the metabolic network and pathways regulated by Yiqi Fumai Lyophilized Injection, which might facilitate the realization of the clinically accurate application of Yiqi Fumai Lyophilized Injection in the treatment of chronic heart failure.

Taurine suppresses liquid-liquid phase separation of lysozyme protein

Taurine is a compatible osmolyte that confers stability to proteins. Recent studies have revealed that liquid-liquid phase separation (LLPS) of proteins underlie the formation of membraneless organelles in cells. In the present study, we evaluated the role of taurine on LLPS of hen egg lysozyme. We demonstrated that taurine decreases the turbidity of the polyethylene glycol-induced crowding solution of lysozyme. We also demonstrated that taurine attenuates LLPS-dependent cloudiness of lysozyme solution with 0.5 or 1 M NaCl at a critical temperature. Moreover, we observed that taurine inhibits LLPS formation of a heteroprotein mix solution of lysozyme and ovalbumin. These data indicate that taurine can modulate the formation of LLPS of proteins.

Water-soluble alkaloids extracted from Aconiti Radix lateralis praeparata protect against chronic heart failure in rats via a calcium signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Many studies have shown the beneficial effects of aconite water-soluble alkaloid extract (AWA) in experimental models of heart disease, which have been ascribed to the presence of aconine, hypaconine, talatisamine, fuziline, neoline, and songorine. This study evaluated the effects of a chemically characterized AWA by chemical content, evaluated its effects in suprarenal abdominal aortic coarctation surgery (AAC)-induced chronic heart failure (CHF) in rats, and revealed the underlying mechanisms of action by proteomics.

METHODS

Rats were distributed into different groups: sham, model, and AWA-treated groups (10, 20, and 40 mg/kg/day). Sham rats received surgery without AAC, whereas model rats an AWA-treated groups underwent AAC surgery. after 8 weeks, the treatment group was fed AWA for 4 weeks, and body weight was assessed weekly. At the end of the treatment, heart function was tested by echocardiography. AAC-induced chronic heart failure, including myocardial fibrosis, cardiomyocyte hypertrophy, and apoptosis, was evaluated in heart tissue and plasma by RT-qPCR, ELISA, hematoxylin and eosin (H&E) staining, Masson's trichrome staining, TUNEL staining, and immunofluorescence staining of α-SMA, Col Ⅰ, and Col Ⅲ. Then, a proteomics approach was used to explore the underlying mechanisms of action of AWA in chronic heart failure.

RESULTS

AWA administration reduced body weight gain, myocardial fibrosis, cardiomyocyte hypertrophy, and apoptosis, and rats showed improvement in cardiac function compared to model group. The extract significantly ameliorated the AAC-induced altered expression of heart failure markers such as ANP, NT-proBNP, and β-MHC, as well as fibrosis, hypertrophy markers MMP-2 and MMP-9, and other heart failure-related factors including plasma levels of TNF-α and IL-6. Furthermore, the extract reduced the protein expression of α-SMA, Col Ⅰ, and Col Ⅲ in the left ventricular (LV), thus inhibiting the LV remodeling associated with CHF. In addition, proteomics characterization of differentially expressed proteins showed that AWA administration inhibited left ventricular remodeling in CHF rats via a calcium signaling pathway, and reversed the expression of RyR2 and SERCA2a.

CONCLUSIONS

AWA extract exerts beneficial effects in an AAC-induced CHF model in rats, which was associated with an improvement in LV function, hypertrophy, fibrosis, and apoptotic status. These effects may be related to the regulation of calcium signaling by the altered expression of RyR2 and SERCA2a.

Effect of type of diet on blood and plasma taurine concentrations, cardiac biomarkers, and echocardiograms in 4 dog breeds

Background

Associations of diet with dilated cardiomyopathy are under investigation.

Objectives

That cardiac assessment would show abnormalities in healthy dogs eating grain‐free (GF) diets or diets with Food and Drug Administration (FDA)‐listed ingredients of concern (peas, lentils, or potatoes) as top 10 ingredients (FDA‐PLP), but not in dogs eating grain‐inclusive (GI) diets or diets without FDA‐listed ingredients of concern (PLP) in the top 10 ingredients (NoFDA‐PLP).

Animals

One hundred eighty‐eight healthy Doberman Pinschers, Golden Retrievers, Miniature Schnauzers, and Whippets.

Methods

This study was an observational cross‐sectional study. Echocardiograms, cardiac biomarkers, and blood and plasma taurine concentrations were compared between dogs eating GF (n = 26) and GI (n = 162) diets, and between FDA‐PLP (n = 39) and NoFDA‐PLP (n = 149) diets, controlling for age and breed. Demographic characteristics, murmurs, genetic status, and ventricular premature complexes (VPCs) during examination were compared between dogs eating different diet types.

Results

No differences in echocardiographic variables, N‐terminal pro‐B‐type natriuretic peptide or whole blood taurine were noted between dogs eating different diet types. Dogs eating GF diets had higher median high‐sensitivity cardiac troponin I (hs‐cTnI) (GF 0.076 ng/mL [Interquartile range (IQR), 0.028‐0.156] vs. GI 0.048 [IQR, 0.0026‐0.080]; P < .001) and higher median plasma taurine (GF 125 nmol/mL [IQR, 101‐148] vs GI 104 [IQR, 86‐123]; P = .02) than dogs eating GI diets. Dogs eating FDA‐PLP diets had higher median hs‐cTnI (0.059 ng/mL [IQR, 0.028‐0.122]) than dogs eating NoFDA‐PLP diets (0.048 [IQR, 0.025‐0.085]; P = .006). A greater proportion of dogs eating FDA‐PLP diets (10%) had VPCs than dogs eating NoFDA‐PLP diets (2%; P = .04).

Conclusions and Clinical Importance

Higher hs‐cTnI in healthy dogs eating GF and FDA‐PLP diets might indicate low‐level cardiomyocyte injury.

Dietary Thiols: A Potential Supporting Strategy against Oxidative Stress in Heart Failure and Muscular Damage during Sports Activity

Moderate exercise combined with proper nutrition are considered protective factors against cardiovascular disease and musculoskeletal disorders. However, physical activity is known not only to have positive effects. In fact, the achievement of a good performance requires a very high oxygen consumption, which leads to the formation of oxygen free radicals, responsible for premature cell aging and diseases such as heart failure and muscle injury. In this scenario, a primary role is played by antioxidants, in particular by natural antioxidants that can be taken through the diet. Natural antioxidants are molecules capable of counteracting oxygen free radicals without causing cellular cytotoxicity. In recent years, therefore, research has conducted numerous studies on the identification of natural micronutrients, in order to prevent or mitigate oxidative stress induced by physical activity by helping to support conventional drug therapies against heart failure and muscle damage. The aim of this review is to have an overview of how controlled physical activity and a diet rich in antioxidants can represent a “natural cure” to prevent imbalances caused by free oxygen radicals in diseases such as heart failure and muscle damage. In particular, we will focus on sulfur-containing compounds that have the ability to protect the body from oxidative stress. We will mainly focus on six natural antioxidants: glutathione, taurine, lipoic acid, sulforaphane, garlic and methylsulfonylmethane.

Plasma amino acid metabolomic pattern in heart failure patients with either preserved or reduced ejection fraction: The relation to established risk variables and prognosis

Communication between amino acids (AAs) and heart failure (HF) is unclear. We evaluate the plasma metabolomic profile of AAs in HF and its subgroups and association with clinical features. This is a case-control study in which 90 patients with HF, 63 with reduced ejection fraction (HFrEF) and 27 with preserved ejection fraction (HFpEF), were compared with 60 controls. The quantitative measurement of plasma concentrations of AA metabolites was performed using an AA analyzer. Compared with controls, HF patients had significantly higher levels of nine AAs and significantly lower levels of seven AAs. Leu, phenylalanine (Phe), and methionine (Met) were the independent predictors of HF that remained significant after adjustment for confounding factors in multivariate analysis. There was a significant difference in 10 AAs and some clinical features between HFpEF and HFrEF. The plasma levels of six AAs were significantly increased across the different New York Heart Association (NYHA) classes, (class II, class III, class IV) but they were not predictor of reduced EF and NYHA in multivariate regression analysis. There were significant associations between Leu, Phe, and Met with cardiovascular risk variables and prognosis. In conclusion, plasma Leu, Phe, and Met provide early prediction and prognostic values of HF. The plasma AAs could have significant impact on the risk-stratifying HFrEF and HFpEF and NYHA functional class but do not predict them.

Mechanisms Underlying Development of Taurine-Deficient Cardiomyopathy

Taurine is a ubiquitous β-amino acid that plays an essential role in ensuring normal mitochondrial and myocardial function. In the mitochondria, taurine reacts with a tRNA forming a 5-taurinomethyluridine conjugate that primarily regulates the biosynthesis of the mitochondria encoded protein, ND6, which serves as a subunit of complex I of the respiratory chain. Impaired formation of the taurine conjugate reduces activity of complex I and plays a central role in the pathophysiology of the mitochondrial disease MELAS (myopathy, encephalopathy, lactic acidosis and stroke-like episodes). The restoration of mitochondrial levels of the taurine conjugate enhances electron flux through the respiratory chain, thereby preventing at least some of the symptoms of MELAS. Taurine therapy also diminishes the severity of congestive heart failure, an observation that led to its approval for the treatment of congestive heart failure in Japan. The review article discusses the role of defective calcium handling, reduced ATP generation, enhanced oxidative stress and apoptosis in the development of taurine-deficient cardiomyopathy. Some patients suffering from congestive heart failure are taurine-deficient, an observation supporting the hypothesis that low taurine levels contribute to the severity of heart failure. Thus, mishandling of taurine leads to mitochondrial dysfunction, which is involved in the development of both MELAS and congestive heart failure.

Targeted metabolomic analysis of serum amino acids in the adult Fontan patient with a dominant left ventricle

Growing interest lies in the assessment of the metabolic status of patients with a univentricular circulation after Fontan operation, especially in changes of amino acid metabolism. Using targeted metabolomic examinations, we investigated amino acid metabolism in a homogeneous adult Fontan-patient group with a dominant left ventricle, seeking biomarker patterns that might permit better understanding of Fontan pathophysiology and early detection of subtle ventricular or circulatory dysfunction. We compared serum amino acid levels (42 analytes; AbsoluteIDQ p180 kit, Biocrates Life Sciences, Innsbruck, Austria) in 20 adult Fontan patients with a dominant left ventricle and those in age- and sex-matched biventricular controls. Serum concentrations of asymmetric dimethylarginine, methionine sulfoxide, glutamic acid, and trans-4-hydroxyproline and the methionine sulfoxide/methionine ratio (Met-SO/Met) were significantly higher and serum concentrations of asparagine, histidine, taurine, and threonine were significantly lower in patients than in controls. Met-SO/Met values exhibited a significant negative correlation with oxygen uptake during exercise. The alterations in amino acid metabolome that we found in Fontan patients suggest links between Fontan pathophysiology, altered cell energy metabolism, oxidative stress, and endothelial dysfunction like those found in biventricular patients with congestive heart failure. Studies of extended amino acid metabolism may allow better understanding of Fontan pathophysiology that will permit early detection of subtle ventricular or circulatory dysfunction in Fontan patients.

Taurine Stimulates Thermoregulatory Genes in Brown Fat Tissue and Muscle without an Influence on Inguinal White Fat Tissue in a High-Fat Diet-Induced Obese Mouse Model

This study was conducted to investigate if taurine supplementation stimulates the induction of thermogenic genes in fat tissues and muscles and decipher the mechanism by which taurine exerts its anti-obesity effect in a mildly obese ICR (CD-1®) mouse model. Three groups of ICR mice were fed a normal chow diet, a high-fat diet (HFD), or HFD supplemented with 2% taurine in drinking water for 28 weeks. The expression profiles of various genes were analyzed by real time PCR in interscapular brown adipose tissue (BAT), inguinal white adipose tissue (iWAT), and the quadriceps muscles of the experimental groups. Genes that are known to regulate thermogenesis like PGC-1α, UCP-1, Cox7a1, Cox8b, CIDE-A, and β₁-, β₂-, and β₃-adrenergic receptors (β-ARs) were found to be differentially expressed in the three tissues. These genes were expressed at a very low level in iWAT as compared to BAT and muscle. Whereas, HFD increased the expression of these genes. Taurine supplementation stimulated the expression of UCP-1, Cox7a1, and Cox8b in BAT and only Cox7a1 in muscle, while there was a decrease in iWAT. In contrast, fat deposition-related genes, monoamine oxidases (MAO)-A, and -B, and lipin-1, were decreased by taurine supplementation only in iWAT and not in BAT or muscle. In conclusion, the potential anti-obesity effects of taurine may be partly due to upregulated thermogenesis in BAT, energy metabolism of muscle, and downregulated fat deposition in iWAT.

In Vivo and In Vitro Study of N-Methyltaurine on Pharmacokinetics and Antimuscle Atrophic Effects in Mice

Various types of seaweed are potential functional foods as they contain multiple bioactive compounds. N-Methyltaurine (NMT) is a taurine derivative metabolite found in a type of red algae. The functional actions of NMT in mammalian animals have not been investigated, but the parent compound, taurine, possesses a variety of cellular actions. To explore the beneficial role of NMT in animals, the present study analyzed the effect of NMT against glucocorticoid-induced skeletal muscle atrophy. Glucocorticoids are one of the major causes of pathological muscle atrophy. Initially, we assessed the bioavailability of ingested NMT by determining its concentration in mouse blood. The bioavailability of orally administered NMT was found to be 96.1% that of intravenously administered NMT. Mice maintained on water containing 0.5% NMT for several days lead to the distribution of the taurine derivative to various tissues, including skeletal muscles. Like taurine, the delivery of NMT to skeletal muscles or myoblast cells is cytoprotective. The treatment with NMT prevents dexamethasone-induced atrophy of myotubes derived from C2C12 cells. Similarly, the addition of 0.5% NMT to drinking water attenuates dexamethasone-mediated reduction in muscle mass of the treated mice. The present study supports the hypothesis that orally administered NMT partially reverses skeletal muscle atrophy.

Taurine attenuates isoproterenol-induced H9c2 cardiomyocytes hypertrophy by improving antioxidative ability and inhibiting calpain-1-mediated apoptosis

Pathological cardiac hypertrophy is ultimately accompanied by cardiomyocyte apoptosis. Apoptosis mainly related to calpain-1-mediated apoptotic pathways. Studies had proved that taurine can maintain heart health through antioxidation and antiapoptotic functions, but the effect of taurine on cardiac hypertrophy is still unclear. This study aimed to determine whether taurine could inhibit calpain-1-mediated mitochondria-dependent apoptotic pathways in isoproterenol (ISO)-induced hypertrophic cardiomyocytes. We found that taurine could inhibit the increase in cell surface area and reduce the protein expression levels of the hypertrophic markers atrial natriuretic peptide, brain natriuretic polypeptide, and β-myosin heavy chain. Taurine also reduced ROS, intracellular Ca²⁺ overload and mitochondrial membrane potential. Moreover, taurine inhibited cardiomyocyte apoptosis by decreasing the protein expression of calpain-1, Bax, t-Bid, cytosolic cytochrome c, Apaf-1, cleaved caspase-9 and cleaved caspase-3 and by enhancing calpastatin and Bcl-2 protein expression. Calpain-1 small interfering RNA transfection results showed similar antiapoptotic effects as the taurine prevention group. However, compared with the two treatments, taurine inhibited the expression of cleaved caspase-9 more significantly. Therefore, we believe that taurine prevents ISO-induced H9c2 cardiomyocyte hypertrophy by inhibiting oxidative stress, intracellular Ca²⁺ overload, the calpain-1-mediated mitochondria-dependent apoptotic pathway and cleaved caspase-9 levels.

Taurine prevents cardiomyocyte apoptosis by inhibiting the calpain-1/cytochrome c pathway during RVH in broilers

The calpain-1-activated apoptotic pathway plays a key role in right ventricular hypertrophy (RVH). Taurine has been shown to attenuate apoptosis by inhibiting calpain activity. This experiment aimed to determine whether taurine could prevent RVH by inhibiting the calpain-1/cytochrome c apoptotic pathway. The broilers were given 1% taurine dissolved in drinking water and were raised at 10 °C ~ 12 °C from day 21 to day 42. At 21 d, 28 d, 35 d and 42 d, the right ventricular (RV) tissues were collected. Increased RVH index, angiotensin II, norepinephrine and atrial natriuretic peptide mRNA expression were reduced by taurine in the broiler RVs. Taurine obviously inhibited cardiomyocyte apoptosis via maintaining the mitochondrial membrane potential and decreased the activation of caspase-9 and caspase-3 in the broiler RVs. The antioxidant assay demonstrated that taurine enhanced the activities of superoxide dismutase, total antioxidant capacity and glutathione peroxidase and the glutathione/glutathione disulfide ratio. Western blot results revealed that taurine also downregulated the expression of calpain-1 and cytosolic cytochrome c while upregulating the expression of Bcl-2/Bax and mitochondrial cytochrome c in broiler cardiomyocytes during RVH. In summary, we found that taurine could enhance cardiomyocyte antioxidant ability and further prevented cardiomyocyte apoptosis by inhibiting the calpain-1/cytochrome c pathway during RVH in broilers.

Important roles of dietary taurine, creatine, carnosine, anserine and 4-hydroxyproline in human nutrition and health

Taurine (a sulfur-containing β-amino acid), creatine (a metabolite of arginine, glycine and methionine), carnosine (a dipeptide; β-alanyl-L-histidine), and 4-hydroxyproline (an imino acid; also often referred to as an amino acid) were discovered in cattle, and the discovery of anserine (a methylated product of carnosine; β-alanyl-1-methyl-L-histidine) also originated with cattle. These five nutrients are highly abundant in beef, and have important physiological roles in anti-oxidative and anti-inflammatory reactions, as well as neurological, muscular, retinal, immunological and cardiovascular function. Of particular note, taurine, carnosine, anserine, and creatine are absent from plants, and hydroxyproline is negligible in many plant-source foods. Consumption of 30 g dry beef can fully meet daily physiological needs of the healthy 70-kg adult human for taurine and carnosine, and can also provide large amounts of creatine, anserine and 4-hydroxyproline to improve human nutrition and health, including metabolic, retinal, immunological, muscular, cartilage, neurological, and cardiovascular health. The present review provides the public with the much-needed knowledge of nutritionally and physiologically significant amino acids, dipeptides and creatine in animal-source foods (including beef). Dietary taurine, creatine, carnosine, anserine and 4-hydroxyproline are beneficial for preventing and treating obesity, cardiovascular dysfunction, and ageing-related disorders, as well as inhibiting tumorigenesis, improving skin and bone health, ameliorating neurological abnormalities, and promoting well being in infants, children and adults. Furthermore, these nutrients may promote the immunological defense of humans against infections by bacteria, fungi, parasites, and viruses (including coronavirus) through enhancing the metabolism and functions of monocytes, macrophages, and other cells of the immune system. Red meat (including beef) is a functional food for optimizing human growth, development and health.

Taurine protects against cardiac dysfunction induced by pressure overload through SIRT1-p53 activation

BACKGROUND

Heart failure (HF) is an epidemic disease with increased incidence annually. It has been reported that taurine can improve cardiac function. This study investigated the cardioprotective effects of taurine in pressure-loaded HF mice and elucidated the possible mechanism.

METHODS

HF models were established by transverse aortic constriction (TAC). Animals were treated with either taurine for 9 weeks and/or the SIRT1 inhibitor EX527 (5 mg/kg/day, every 2days) after TAC operation. Cardiac function and geometry were revealed by echocardiography. Myocardial hypertrophy and fibrosis were assessed using Fluorescent wheat germ agglutinin (WGA) staining and Masson's trichrome staining. Western blot and RT-PCR were performed to elucidate the expression of target proteins and genes respectively. Apoptosis in cardiomyocytes was detected by TUNEL staining. Myocardial oxidative stress was assessed by detecting the concentration of myocardial super oxidative dismutase (SOD) and malonyldialdehyde (MDA) and reactive oxygen species (ROS). Taurine concentrations and NAD⁺/NADH ratio were determined by taurine and NAD⁺/NADH assay kit.

RESULTS

Taurine notably relieved cardiac dysfunction after TAC. The mechanisms were attributed to reduced myocyte hypertrophy and fibrosis, and alleviated apoptosis and oxidative stress. Meanwhile, taurine increased NAD+/NADH ratio，promoted the expression of SIRT1 and suppressed p53 acetylation. However, EX-527(inhibitor of SIRT1) decreased NAD⁺/NADH ratio and increased acetyl-p53 levels, and abolished the cardioprotective effects of taurine on mice subjected to TAC and increased apoptosis and oxidative stress.

CONCLUSION

The mechanism responsible for cardiac-protective effects of taurine in HF induced by pressure overload is associated with the activation of the SIRT1-p53 pathway.

A long-term treatment with taurine prevents cardiac dysfunction in mdx mice

Taurine is an amino acid abundantly present in heart and skeletal muscle. Duchenne muscular dystrophy (DMD) is a genetic disorder in which the absence of dystrophin leads to skeletal muscle wasting and heart failure. An altered taurine metabolism has been described in dystrophic animals and short-term taurine administration exerts promising amelioration of early muscular alterations in the mdx mouse model of DMD. To reinforce the therapeutic and nutraceutical taurine potential in DMD, we evaluated the effects of a long-term treatment on cardiac and skeletal muscle function of mdx mice in a later disease stage. Taurine was administered in drinking water (1 g/kg/day) to wt and mdx mice for 6 months, starting at 6 months of age. Ultrasonography evaluation of heart and hind limb was performed, in parallel with in vivo and ex vivo functional tests and biochemical, histological and gene expression analyses. 12-month-old mdx mice showed a significant worsening of left ventricular function parameters (shortening fraction, ejection fraction, stroke volume), which were significantly counteracted by the taurine treatment. In parallel, histologic signs of damage were reduced by taurine along with the expression of proinflammatory myocardial IL-6. Interestingly, no effects were observed on hind limb volume and percentage of vascularization or on in vivo and ex vivo muscle functional parameters, suggesting a tissue-specific action of taurine in relation to the disease phase. A trend toward increase in taurine was found in heart and quadriceps from treated animals, paralleled by a slight decrease in mdx mice plasma. Our study provides evidences that taurine can prevent late heart dysfunction in mdx mice, further corroborating the interest on this amino acid toward clinical trials.

Taurine-Conjugated Metabolites in Hearts

Mammalian tissues, especially the heart, contain high concentrations of taurine, a beta-amino acid that possesses a variety of physiological functions. While it is well known that taurine reacts with several metabolites, such as bile acids and fatty acids, taurine-conjugated metabolites in the heart have not been specifically studied. Recently, we performed Liquid chromatography-mass spectrometry- (LC-MS-) based metabolome analysis, comparing metabolome profiles of hearts from taurine transporter knockout (TauTKO) mice and wild-type mice to identify differences in taurine-conjugated metabolite content of the two phenotypes. Comparison of the metabolite profiles revealed taurine-containing dipeptides, such as glutamyltaurine, which are present in wild-type but not in TauTKO hearts. These data suggest that taurine functions not only as a free osmolyte but also as a conjugated metabolite within the heart.

The Effect of Acute Taurine Ingestion on Human Maximal Voluntary Muscle Contraction

PURPOSE

This study aimed to examine the effect of taurine ingestion on maximal voluntary muscle torque and power in trained male athletes with different caffeine habits.

METHODS

Fourteen male athletes 21.8 ± 2.5 yr old were separated into caffeine and noncaffeine consumers to control for the effect of caffeine withdrawal on muscle function. On separate occasions, participants performed four isokinetic or three maximal isometric knee extensions with and without taurine (40 mg·kg body mass) after a double-blind, counterbalanced design. Muscle contractile performances were compared between the first sets as well as between the sets where these variables scored best.

RESULTS

In response to isokinetic contraction, taurine treatment in the noncaffeine consumers resulted in a significant fall in first (-16.1%; P = 0.013) and best peak torque (-5.0%; P = 0.016) as well as in first (-17.7%; P = 0.015) and best power output (-8.0%; P = 0.008). In the caffeine consumers deprived of caffeine, taurine intake improved best power (5.2%; P = 0.045). With respect to the isometric variables, there was a significant decrease in the first (-5.1%; P = 0.002) and best peak torque (-4.3%; P = 0.032) in the noncaffeine group, but no effect in the group of caffeine consumers deprived of caffeine. Taurine ingestion increased blood taurine levels but had no effect on plasma amino acid levels.

CONCLUSIONS

Taurine ingestion is detrimental to maximal voluntary muscle power and both maximal isokinetic and isometric peak torque in noncaffeine consumers, whereas taurine ingestion in caffeine-deprived caffeine consumers improves maximal voluntary muscle power but has no effect on other aspects of contractile performance.

Taurine alleviates endoplasmic reticulum stress in the chondrocytes from patients with osteoarthritis

Osteoarthritis (OA), characterized by pain and stiffness, swelling, deformity and dysfunction of joints, affects large numbers of population. The purpose of this study was to discover the effects of taurine in human OA chondrocytes and explore the underlying mechanisms. 46 patients with different grades of OA were recruited. Of these patients, 24 underwent total knee replacement and cartilages were harvested. The mRNA expressions of type II collagen (Collagen II) and endoplasmic reticulum (ER) stress markers (GRP78, GADD153 and Caspase-12) in cartilages were quantified by qRT-PCR. Cell viability and apoptosis of patient-derived chondrocytes were assessed by the CCK-8 assay and flow cytometry assay, respectively. Meanwhile, protein levels of Collagen II and ER stress markers both in cartilages and chondrocytes were evaluated by Western blot. The mRNA and protein levels of Collagen II decreased as OA progressed, while the expressions of ER stress markers increased dramatically. H₂O₂ induced ER stress in chondrocytes, as shown by the significant increase in the expression of ER stress markers, inhibited chondrocyte viability and Collagen II synthesis, promoted apoptosis. However, taurine treatment inhibited these above phenomena. These results indicated that taurine exhibited anti-OA effect by alleviating H₂O₂ induced ER stress and subsequently inhibiting chondrocyte apoptosis.

Liver Antioxidant Enzyme Activities Increase After Taurine in Ovariectomized Rats

The present study was performed to know the effects of taurine on the lipid level of plasma and liver, lipid peroxidation and antioxidative enzyme activities of liver tissue in ovariectomized (OVX) rats fed cholesterol. Twenty-four female SD rats (200 ± 5 g) were grouped; sham and ovariectomy groups, which were each randomly subgrouped; fed control and control supplemented with taurine (20 g/kg diet). The serum total cholesterol, TG (triglyceride), LDL-cholesterol, athrogenic index, and HDL-cholesterol of taurine diet group were not statistically different. Also the levels of liver total cholesterol, triglyceride were not considerably different in different diets. The lipid peroxidation of malondialdehyde concentration was considerably lower in taurine-feeding group than control-feeding group in ovariectomy group. The superoxide dismutase activity in liver tissue was significantly higher in rats fed taurine than in rats fed control diet in OVX rats. GSH-Px (glutathione peroxidase) activity was statistically greater at the rats fed taurine diets compared to rats fed control diet in ovariectomy group. Activity of catalase was higher in taurine group than in control group in ovariectomy group, but it was not significantly different. In conclusion, taurine supplementation was beneficial on antioxidative enzyme activities of liver tissue in ovariectomized rats fed cholesterol.

Protective Effect of Taurine on Mice with Doxorubicin-induced Acute Kidney Injury

Nephrotic syndrome is still a therapeutic challenge because an effective treatment has not been developed. Evidence suggests that multidrug therapy is more effective than monotherapy in amelioration of renal injury. Therefore, we examined if taurine exerts a protective effect on doxorubicin-induced acute kidney injury in mice. Eight-week-old male Balb/c nude mice were used in this study. Taurine was orally administered at a dose of 50 mg/kg and 100 mg/kg body weight for 5 days. In the meantime, the mice were administered intraperitoneal injections of doxorubicin at 15 mg/kg body weight. At 24 h after the doxorubicin challenge, the response in the taurine-treated mice was compared with that in the vehicle-treated control mice. The doxorubicin-induced acute kidney injury model displayed a significant increase in the renal expression of apoptosis-related proteins (p53, phospho-p53, caspase 9, and caspase 3), whereas in the taurine-treated mice, the augmented expression of renal inflammation-related mRNAs such as NF-kB, COX-2, and iNOS was down-regulated. These results suggest that taurine acts as a renoprotective agent by inhibiting apoptosis and inflammation in the kidney of mice with doxorubicin-induced renal injury.

Perinatal Taurine Supplementation Alters Renal Function via Renin-Angiotensin System Overactivity in Adult Female Rats

This study tests the hypothesis that perinatal taurine supplementation followed by a high sugar diet since weaning impairs renal function via renin-angiotensin system (RAS) overactivity in adult female rats. Female Sprague-Dawley rats were fed normal rat chow and given water alone or water containing 3% taurine from conception until weaning. After weaning, the female rats received normal rat chow and water with (CG, TSG) or without (CW, TSW) 5% glucose throughout the experiment. At 7-8 weeks of age, renal function at rest and after an acute saline load was tested in conscious female rats after a week of captopril treatment. Body, heart, and kidney weights were not significantly different among the eight groups. Mean arterial pressures and heart rates were also not different among the groups. While effective renal blood flow did not significantly differ among the eight groups, TSG displayed higher renal vascular resistance compared to CW, CG, and TSW groups. Glomerular filtration rate, filtration fraction, and water and sodium excretion did not significantly differ among the groups. Compared to CW, the saline load significantly depressed fractional water excretion in CG and TSW and fractional sodium excretion in CG, TSW, and TSG groups. Captopril treatment abolished these differences but significantly decreased potassium excretion in CG, TSW, and TSG compared to CW and abolished the increased fractional potassium excretion in TSG compared to CG and TSW groups. These data strongly suggest that in adult female rats, perinatal taurine supplementation, particularly followed by high sugar intake, alters renal function via altered RAS activity.

Pathway Analysis of a Transcriptome and Metabolite Profile to Elucidate a Compensatory Mechanism for Taurine Deficiency in the Heart of Taurine Transporter Knockout Mice

Taurine, which is abundant in mammalian tissues, especially in the heart, is essential for cellular osmoregulation. We previously reported that taurine deficiency leads to changes in the levels of several metabolites, suggesting that alterations in those metabolites might compensate in part for tissue taurine loss, a process that would be important in maintaining cardiac homeostasis. In this study, we investigated the molecular basis for changes in the metabolite profile of a taurine-deficient heart using pathway analysis based on the transcriptome and metabolome profile in the hearts of taurine transporter knockout mice (TauTKO mice), which have been reported by us. First, the genes associated with transport activity, such as the solute carrier (SLC) family, are increased in TauTKO mice, while the established transporters for metabolites that are elevated in the TauTKO heart, such as betaine and carnitine, are not altered by taurine deficiency. Second, the integrated analysis using transcriptome and metabolome data revealed significant increases and/or decreases in the genes involved in Arginine metabolism, Ketone body degradation, Glycerophospholipid metabolism, and Fatty acid metabolism in the KEGG pathway database. In conclusion, these pathway analyses revealed genetic compensatory mechanisms involved in the control of the metabolome profile of the taurine-deficient heart.

HLA-C1 ligands are associated with increased susceptibility to systemic lupus erythematosus

Recently, the role of killer cell immunoglobulin-like receptor (KIR) in autoimmune diseases has received increasing attention. The present study was undertaken to determine the association of KIR genes and the human leukocytes antigen (HLA) ligands with Systemic Lupus Erythematosus (SLE) and accompanying oxidative stress. Presence or absence of 17 KIR and 5 HLA loci was performed using the polymerase chain reaction-sequence specific primer (PCR-SSP) method by case-control study. A total of 45 SLE patients, and 60 healthy controls, all of Sicilian descent, were enrolled. Plasma values of the anti-oxidant molecule Taurine were determined in all subjects by capillary electrophoresis UV detection. The carrier frequency of the KIR2DS2 gene was significantly increased in SLE patients compared to healthy controls (73.3 versus 45.0%; OR = 3.36; 95% CI = 1.46-7.74; p = .005) suggesting a role of KIR2DS2 gene in the susceptibility to disease. We also observed a strong positive association between the presence of HLA-C1 ligands group and the disease (82.2% in SLE patients versus 41.7% in controls; OR = 6.47, 95% CI = 2.58-16.26; p < .0001). Stepwise logistic regression analysis supported the effect of the HLA-C1 ligands in SLE patients (OR = 7.06, 95% CI = 0.07-2.19; p = .002), while the KIR genes were no longer significant. Interestingly, we found that SLE patients HLA-C1 positive showed significantly decreased plasma levels of antioxidant activity marker Taurine (69.38 ± 28.49 μmol/L) compared to SLE patients HLA-C1 negative (108.37 ± 86.09 μmol/L) (p = .03). In conclusion, HLA-C1 ligands group was significantly associated with an increased risk of SLE as well as an increased oxidative stress status overall in SLE patients.

Effects of the kinase inhibitor sorafenib on heart, muscle, liver and plasma metabolism in vivo using non-targeted metabolomics analysis

BACKGROUND AND PURPOSE

The human kinome consists of roughly 500 kinases, including 150 that have been proposed as therapeutic targets. Protein kinases regulate an array of signalling pathways that control metabolism, cell cycle progression, cell death, differentiation and survival. It is not surprising, then, that new kinase inhibitors developed to treat cancer, including sorafenib, also exhibit cardiotoxicity. We hypothesized that sorafenib cardiotoxicity is related to its deleterious effects on specific cardiac metabolic pathways given the critical roles of protein kinases in cardiac metabolism.

EXPERIMENTAL APPROACH

FVB/N mice (10 per group) were challenged with sorafenib or vehicle control daily for 2 weeks. Echocardiographic assessment of the heart identified systolic dysfunction consistent with cardiotoxicity in sorafenib-treated mice compared to vehicle-treated controls. Heart, skeletal muscle, liver and plasma were flash frozen and prepped for non-targeted GC-MS metabolomics analysis.

KEY RESULTS

Compared to vehicle-treated controls, sorafenib-treated hearts exhibited significant alterations in 11 metabolites, including markedly altered taurine/hypotaurine metabolism (25-fold enrichment), identified by pathway enrichment analysis.

CONCLUSIONS AND IMPLICATIONS

These studies identified alterations in taurine/hypotaurine metabolism in the hearts and skeletal muscles of mice treated with sorafenib. Interventions that rescue or prevent these sorafenib-induced changes, such as taurine supplementation, may be helpful in attenuating sorafenib-induced cardiac injury.

A Metabolomics-Based Strategy for the Mechanism Exploration of Traditional Chinese Medicine: Descurainia sophia Seeds Extract and Fractions as a Case Study

A UPLC-QTOF-MS based metabolomics research was conducted to explore potential biomarkers which would increase our understanding of the model and to assess the integral efficacy of Descurainia sophia seeds extract (DS-A). Additionally, DS-A was split into five fractions in descending order of polarity, which were utilized to illustrate the mechanism together. The 26 identified biomarkers were mainly related to disturbances in phenylalanine, tyrosine, tryptophan, purine, arginine, and proline metabolism. Furthermore, heat map, hierarchical cluster analysis (HCA), and correlation network diagram of biomarkers perturbed by modeling were all conducted. The results of heat map and HCA suggested that fat oil fraction could reverse the abnormal metabolism in the model to some extent; meanwhile the metabolic inhibitory effect produced by the other four fractions helped to relieve cardiac load and compensate the insufficient energy supplement induced by the existing heart and lung injury in model rats. Briefly, the split fractions interfered with the model from different aspects and ultimately constituted the overall effects of extract. In conclusion, the metabolomics method, combined with split fractions of extract, is a powerful approach for illustrating pathologic changes of Chinese medicine syndrome and action mechanisms of traditional Chinese medicine.

Potential Benefits of Ameliorating Metabolic and Nutritional Abnormalities in People With Profound Developmental Disabilities

Background:

People with profound developmental disabilities have some of the most severe neurological impairments seen in society, have accelerated mortality due to huge medical challenges, and yet are often excluded from scientific studies. They actually have at least 2 layers of conditions: (1) the original disability and (2) multiple under-recognized and underexplored metabolic and nutritional imbalances involving minerals (calcium, zinc, and selenium), amino acids (taurine, tryptophan), fatty acids (linoleic acid, docosahexaenoic acid, arachidonic acid, adrenic acid, Mead acid, plasmalogens), carnitine, hormones (insulinlike growth factor 1), measures of oxidative stress, and likely other substances and systems.

Summary:

This review provides the first list of metabolic and nutritional abnormalities commonly found in people with profound developmental disabilities and, based on the quality of life effects of similar abnormalities in neurotypical people, indicates the potential effects of these abnormalities in this population which often cannot communicate symptoms.

Key messages:

We propose that improved understanding and management of these disturbed mechanisms would enhance the quality of life of people with profound developmental disabilities. Such insights may also apply to people with other conditions associated with disability, including some diseases requiring stem cell implantation and living in microgravity.

The Modulating Effects of Cardiac Resynchronization Therapy on Myocardial Metabolism in Heart Failure

Heart failure (HF) is associated with changes in cardiac substrate utilization and energy metabolism, including a decline in high-energy phosphate content, mitochondrial dysfunction, and phosphotransfer enzyme deficiency. A shift toward glucose metabolism was noted in the end stage of HF in animals, although HF in humans may not be associated with a shift toward predominant glucose utilization. Deficiencies of micronutrients are well-established causes of cardiomyopathy. Correction of these deficits can improve heart function. The genes governing the energy metabolism were predominantly underexpressed in nonischemic cardiomyopathy and hypertrophic cardiomyopathy but were overexpressed in ischemic cardiomyopathy. Cardiac resynchronization therapy (CRT) has been proven to increase cardiac efficiency without increasing myocardial oxygen consumption. Altered myocardial metabolism is normalized by CRT to improve ventricular function.

Nutritional Deficiency in Patients with Heart Failure

Heart failure (HF) is the main cause of mortality and morbidity in Western countries. Although evidence-based treatments have substantially improved outcomes, prognosis remains poor with high costs for health care systems. In patients with HF, poor dietary behaviors are associated with unsatisfactory quality of life and adverse outcome. The HF guidelines have not recommended a specific nutritional strategy. Despite the role of micronutrient deficiency, it has been extensively studied, and data about the efficacy of supplementation therapy in HF are not supported by large randomized trials and there is limited evidence regarding the outcomes. The aim of the present review is to analyze the state-of-the-art of nutritional deficiencies in HF, focusing on the physiological role and the prognostic impact of micronutrient supplementation.

Impact of chronic administration of anabolic androgenic steroids and taurine on blood pressure in rats

Supraphysiological administration of anabolic androgenic steroids has been linked to increased blood pressure. The widely distributed amino acid taurine seems to be an effective depressor agent in drug-induced hypertension. The purpose of this study was to assess the impact of chronic high dose administration of nandrolone decanoate (DECA) and taurine on blood pressure in rats and to verify the potentially involved mechanisms. The study was conducted in 4 groups of 8 adult male Wistar rats, aged 14 weeks, treated for 12 weeks with: DECA (A group); vehicle (C group); taurine (T group), or with both drugs (AT group). Systolic blood pressure (SBP) was measured at the beginning of the study (SBP₁), 2 (SBP₂) and 3 months (SBP₃) later. Plasma angiotensin-converting enzyme (ACE) activity and plasma end products of nitric oxide metabolism (NO_x) were also determined. SBP₃ and SBP₂ were significantly increased compared to SBP₁ only in the A group (P<0.002 for both). SBP₂, SBP₃ and ACE activity showed a statistically significant increase in the A vs C (P<0.005), andvs AT groups (P<0.05), while NO_x was significantly decreased in the A and AT groups vs controls (P=0.01). ACE activity was strongly correlated with SBP₃ in the A group (r=0.71, P=0.04). These findings suggest that oral supplementation of taurine may prevent the increase in SBP induced by DECA, an effect potentially mediated by angiotensin-converting enzyme.

Diastolic Left Ventricular Function in Relation to Circulating Metabolic Biomarkers in a General Population

Background

The metabolic signature associated with subclinical diastolic left ventricular (LV) dysfunction in the population remains ill defined.

Methods and Results

In 711 randomly recruited Flemish (50.8% women; mean age, 50.8 years), we assessed echocardiographic Doppler indexes of diastolic LV function in relation to 44 circulating metabolites determined by nuclear magnetic resonance spectroscopy. In multivariable‐adjusted regression analysis with Bonferroni correction of significance levels applied, peak a’ decreased (P≤0.048) and e’/a’ increased (P≤0.044) with circulating tyrosine, high‐density lipoprotein apolipoproteins, glucose+glutamine, and an unidentified molecule. Effect sizes expressed per 1‐SD increment in the metabolite ranged from −0.277 to −0.203 cm/s for peak a’ and from +0.047 to +0.054 for e’/a’. In addition, peak a’ decreased (P≤0.031) with glucose+2‐aminobutyrate (−0.261 cm/s) and glucose+2‐phosphoglycerate (−0.209 cm/s). In partial least square discriminant analysis (PLS‐DA), metabolites associated with normal diastolic LV function (n=538) included glucose+glutamine, glucose+2‐aminobutyrate, and glucose+2‐phosphoglycerate, whereas those siding with abnormal function encompassed 4‐aminobutyrate, 4‐hydroxybutyrate, creatinine, and phosphocholine. In receiver operating characteristics plots, adding 3 latent factors identified by PLS‐DA to prohormone brain natriuretic peptide increased (P<0.0001) the area under the curve from 0.64 (95% CI, 0.58–0.68) to 0.73 (0.68–0.78).

Conclusions

In a general population, circulating metabolites indicative of energy substrate utilization and protection against oxidative stress differentiated normal from abnormal diastolic LV function. These findings improve our understanding of the pathophysiology underlying deterioration of diastolic LV function and potentially point to new targets for prevention and treatment of this condition.