Cardioprotective Effects of Cysteine Alone or in Combination With Taurine in Diabetes

Potential Therapies Targeting the Metabolic Reprogramming of Diabetes-Associated Breast Cancer

In recent years, diabetes-associated breast cancer has become a significant clinical challenge. Diabetes is not only a risk factor for breast cancer but also worsens its prognosis. Patients with diabetes usually show hyperglycemia and hyperinsulinemia, which are accompanied by different glucose, protein, and lipid metabolism disorders. Metabolic abnormalities observed in diabetes can induce the occurrence and development of breast cancer. The changes in substrate availability and hormone environment not only create a favorable metabolic environment for tumorigenesis but also induce metabolic reprogramming events required for breast cancer cell transformation. Metabolic reprogramming is the basis for the development, swift proliferation, and survival of cancer cells. Metabolism must also be reprogrammed to support the energy requirements of the biosynthetic processes in cancer cells. In addition, metabolic reprogramming is essential to enable cancer cells to overcome apoptosis signals and promote invasion and metastasis. This review aims to describe the major metabolic changes in diabetes and outline how cancer cells can use cellular metabolic changes to drive abnormal growth and proliferation. We will specifically examine the mechanism of metabolic reprogramming by which diabetes may promote the development of breast cancer, focusing on the role of glucose metabolism, amino acid metabolism, and lipid metabolism in this process and potential therapeutic targets. Although diabetes-associated breast cancer has always been a common health problem, research focused on finding treatments suitable for the specific needs of patients with concurrent conditions is still limited. Most studies are still currently in the pre-clinical stage and mainly focus on reprogramming the glucose metabolism. More research targeting the amino acid and lipid metabolism is needed.

In Silico Prediction and In Vitro Assessment of Multifunctional Properties of Postbiotics Obtained From Two Probiotic Bacteria

In this study, a global metabolite profile using Raman spectroscopy analysis was obtained in order to predict, by an in silico prediction of activity spectra for substance approach, the bioactivities of the intracellular content (IC) and cell wall (CW) fractions obtained from Lactobacillus casei CRL 431 and Bacillus coagulans GBI-30 strains. Additionally, multifunctional in vitro bioactivity of IC and CW fractions was also assessed. The metabolite profile revealed a variety of compounds (fatty acids, amino acids, coenzyme, protein, amino sugars), with significant probable activities (Pa > 0.7) as immune-stimulant, anti-inflammatory, neuroprotective, antiproliferative, immunomodulator, and antineoplastic, among others. Moreover, in vitro assays exhibited that both IC and CW fractions presented angiotensin-converting enzyme-inhibitory (> 90%), chelating (> 79%), and antioxidant (ca. 22-57 cellular antioxidant activity units) activities. Our findings based on in silico and in vitro analyses suggest that L. casei CRL 431 and B. coagulans GBI-30 strains appear to be promising sources of postbiotics and may impart health benefits by their multifunctional properties.

Taurine and cardiac disease: state of the art and perspectives

Taurine is a nonessential amino acid that has received much attention. Two organs, the heart and the brain, are known to produce their own taurine, but in very limited quantities. It is for this reason that supplementation with this amino acid is necessary. Today, taurine is present in almost all energy drinks. A very vast literature reported beneficial effects of taurine in hepatic dysfunction, gastrointestinal injury, kidney diseases, diabetes, and cardiovascular diseases. Most of its effects were attributed to its modulation of Ca2+homeostasis as well as to its antioxidant properties. In this review, we will focus on the current status of taurine modulation of the cardiovascular system and discuss future avenues for its use as a supplement therapy in a specific cardiovascular disease, namely hypertrophy, and heart failure.

Upregulation of miR-93 and inhibition of LIMK1 improve ventricular remodeling and alleviate cardiac dysfunction in rats with chronic heart failure by inhibiting RhoA/ROCK signaling pathway activation

Objective: There are some researches about the role of microRNA (miRNA) in chronic heart failure (CHF) were performed, but the study about miR-93’s function in CHF is scarcely investigated. Thus, we determined to probe into the effects of miR-93 in rats with CHF by targeting LIMK1 through regulating RhoA/ROCK pathway.

Results: We found increased LIMK1 and decreased miR-93 in CHF rats, and up-regulation of miR-93 inhibited LIMK1, RhoA and ROCK1 expression in CHF rats. Up-regulation of miR-93 or inhibition of LIMK1 decreased oxidative stress, inflammatory factors, as well as apoptosis-related indicators in CHF rats. LIMK1 was confirmed as a direct target gene of miR-93.

Conclusion: Our study provides evidence that upregulated miR-93 and downregulated LIMK1 improve ventricular remodeling and reduce cardiac dysfunction in CHF rats by inhibiting RhoA/ROCK signaling pathway activation.

Methods: First, rat models of CHF were established by aortic coarctation, and the rats were injected with miR-93 mimics, LIMK1-siRNA or overexpressed-LIMK1. Then expression of miR-93, LIMK1, RhoA, and ROCK1 expression in myocardial tissues were detected, after which indices of cardiac ultrasound, hemodynamics, and oxidative stress, inflammatory factors, apoptosis-related indicators were detected via a series of assays. Finally, the targeting relationship of miR-93 and LIMK1 was verified.

Hyperglycemia (high-glucose) decreases L-cysteine and glutathione levels in cultured monocytes and blood of Zucker diabetic rats

L-Cysteine (LC) is an essential precursor of GSH biosynthesis. GSH is a major physiological antioxidant, and its depletion increases oxidative stress. Diabetes is associated with lower blood levels of LC and GSH. The mechanisms leading to a decrease in LC in diabetes are not entirely known. This study reports a significant decrease in LC in human monocytes exposed to high glucose (HG) concentrations as well as in the blood of type 2 diabetic rats. Thus, a significant decrease in the level of LC in response to exposure to HG supports the assertion that uncontrolled hyperglycemia contributes to a reduction of blood levels of LC and GSH seen in diabetic patients. Increased requirement of LC to replace GSH needed to scavenge excess ROS generated by hyperglycemia can result in lower levels of LC and GSH. Animal and human studies report that LC supplementation improves GSH biosynthesis and is beneficial in lowering oxidative stress and insulin resistance. This suggests that hyperglycemia has a direct role in the impairment of LC and GSH homeostasis in diabetes.

Nutraceutical profile and evidence of alleviation of oxidative stress by Spirogyra porticalis (Muell.) Cleve inhabiting the high altitude Trans-Himalayan Region

The high altitude trans-Himalayan region indeed is hostile domain for survival. Algae inhabiting  this  hostile terrain have evolutionarily developed mechanisms to produce unique adaptogenic molecules against climatic stressors. The present study has focused on the high altitude alga Spirogyra porticalis (Muell.) Cleve- a filamentous Charophyte, and reports the estimation of amino acids (AAs), fatty acids (FAs), vitamins and their efficacy against oxidative stress. Reverse phase-HPLC, GC-FID and rapid resolution-LC/tandem mass spectrometry were used for analysis of AAs, FAs and vitamins. Analysis of the alga  revealed the presence of 19 AAs (239.51 ± 8.57 to 13102.40 ± 11.08 µg/g), dominated by alanine, proline and lysine. Enriched phenylalanine, cysteine-HCl and high lysine:arginine ratio could also have beneficial impact against hypoxia -induced cognitive impairment. A total of 9 FAs were detected (0.43 ± 0.00% to 34.76 ± 0.52%). Polyunsaturated and monounsaturated FAs were found to be dominant. The alga showed the presence of 8 vitamins within the range of 39.654 ± 3.198 to 5468.184 ± 106.859 µg/Kg, wherein Vitamin B₅, B₃ and B₂ were dominant. 600 µg/ml of methanolic extract showed recovery of GSH and trolox equivalent antioxidants in rat blood/hemolysate, while 400 µg/ml of extract showed revival in superoxide dismutase (SOD) activity. The present study concludes that the alga S. porticalis has immense potential to counter oxidative stress as a nutraceutical supplement.

Prophylactic role of taurine and its derivatives against diabetes mellitus and its related complications

Taurine is a conditionally essential amino acid present in the body in free form. Mammalian taurine is synthesized in the pancreas via the cysteine sulfinic acid pathway. Anti-oxidation and anti-inflammation are two main properties through which it exerts its therapeutic effects. Many studies have shown its excellent therapeutic potential against diabetes mellitus and related complications like diabetic neuropathy, retinopathy, nephropathy, hematological dysfunctions, reproductive dysfunctions, liver and pancreas related complications etc. Not only taurine, a number of its derivatives have also been reported to be important in ameliorating diabetic complications. The present review has been aimed to describe the importance of taurine and its derivatives against diabetic metabolic syndrome and related complications.

The Effects of Subchronic Methionine Overload Administered Alone or Simultaneously with L-cysteine or N-acetyl-L-cysteine on Body Weight, Homocysteine Levels and Biochemical Parameters in the Blood of Male Wistar Rats

Hyperhomocysteinemia (HHC), both basal and after methionine load, may occur due to genetic disorders or deficiencies of nutrients that affect the remethylation or trans-sulphuration pathways during methionine metabolism. HHC is involved in the pathogenesis of many illnesses as a result of its prooxidative effect and its impairment of antioxidative protection. The aim was to examine the effects of subchronic methionine overload on the body weight and standard biochemical parameters in rat serum and to examine whether simultaneous subchronic intraperotoneal administration of methionine alone or together with L-cysteine or N-acetyl-cysteine resulted in a change in the body weight and biochemical parameters in the rat serum. The research was conducted during a three-week period (male Wistar albino rats, n=36, body weight of approximately 160 g, age of 15-20 days), and the animals were divided into a control group and three experimental groups of 8-10 animals each: a) control group (0.9% sodium chloride 0.1-0.2 ml/day); b) methionine (0.8 mmol/kg/bw/day) (MET group); c) methionine (0.8 mmol/kg/bw/day) + L-cysteine (7 mg/kg/bw/day) (L-cys+MET group); and d) methionine (0.8 mmol/kg/bw/day) + N-acetyl-L-cysteine (50 mg/kg/bw/day) (NAC+MET group). In addition to the body weight monitoring, the levels of total homocysteine and the standard biochemical parameters in blood samples (plasma or serum) were determined. The results indicated that monitoring the homocysteine levels and standard biochemical parameters in blood could be used for analysis and could provide an excellent guideline for distinguishing between toxic and non-toxic doses of methionine intake, which may be meaningful for clinical applications.

Effects of nimesulide, a selective COX-2 inhibitor, on cardiovascular function in 2 rat models of diabetes

Cyclooxygenase-2 (COX-2) has been found to be activated in diabetes. We investigated whether nimesulide (selective COX-2 inhibitor) alters cardiovascular responses to adrenaline in 2 rat models of diabetes. Wistar rats (5-week old) were continuously fed a normal or high-fructose diet (60% of caloric intake). At week 2, half of the rats in each diet regimen were given streptozotocin (STZ) (60 mg/kg, intravenously). At week 6, cardiovascular effects of adrenaline (6 and 16 × 10 mol·kg·min, intravenously) were measured in 4 groups of thiobutabarbital-anesthetized rats (control, fructose, STZ, and fructose-streptozotocin [F-STZ]) before and after the injection of nimesulide (3 mg/kg, intravenously). Both the STZ and F-STZ groups exhibited hyperglycemia and significantly (P < 0.05) reduced left ventricular contractility, mean arterial pressure, arterial and venous resistance, and mean circulatory filling pressure (index of venous tone) responses to adrenaline, relative to the control and fructose groups. Nimesulide did not affect responses in the control and fructose groups but increased the venous and, to a less extent, arterial constriction to adrenaline in both the groups of diabetic rats. The cardiac contractile responses, however, were not altered after nimesulide treatment. The results show that nimesulide partially restored arterial and venous constriction to adrenaline in rats with STZ- and F-STZ-induced diabetes.

Cardiac taurine and principal amino acids in right and left ventricles of patients with either aortic valve stenosis or coronary artery disease: the importance of diabetes and gender

Free intracellular taurine and principal α-amino acids (glutamate, glutamine, aspartate, asparagine and alanine) are abundant in human heart. They are cellular regulators and their concentration can change in response to disease and cardiac insults and have been shown to differ between hypertrophic left ventricle (LV) and the relatively "normal" right ventricle (RV) in patients with aortic valve stenosis (AVS). This difference has not been shown for coronary artery disease (CAD) and there are no studies that have simultaneously compared amino acid content in LV and RV from different pathologies. In this study we investigated the effect of disease on taurine and principal amino acids in both LV and RV, measured in myocardial biopsies collected from patients with either AVS (n = 22) or CAD (n = 36). Amino acids were extracted and measured using HPLC. Intra- and inter-group analysis was performed as well as subgroup analysis focusing on gender in AVS and type 2 diabetes in CAD. LV of both groups has significantly higher levels of taurine compared to RV. This difference disappears in both diabetic CAD patients and in male AVS patients. Alanine was the only α-amino acid to be altered by diabetes. LV of female AVS patients had significantly more glutamate, aspartate and asparagine than corresponding RV, whilst no difference was seen between LV and RV in males. LV of females has higher glutamate and glutamine and less metabolic stress than LV of males. This work shows that in contrast to LV, RV responds differently to disease which can be modulated by gender and diabetes.

Simulating an infection growth model in certain healthy metabolic pathways of Homo sapiens for highlighting their role in Type I Diabetes mellitus using fire-spread strategy, feedbacks and sensitivities

Disease Systems Biology is an area of life sciences, which is not very well understood to date. Analyzing infections and their spread in healthy metabolite networks can be one of the focussed areas in this regard. We have proposed a theory based on the classical forest fire model for analyzing the path of infection spread in healthy metabolic pathways. The theory suggests that when fire erupts in a forest, it spreads, and the surrounding trees also catch fire. Similarly, when we consider a metabolic network, the infection caused in the metabolites of the network spreads like a fire. We have constructed a simulation model which is used to study the infection caused in the metabolic networks from the start of infection, to spread and ultimately combating it. For implementation, we have used two approaches, first, based on quantitative strategies using ordinary differential equations and second, using graph-theory based properties. Furthermore, we are using certain probabilistic scores to complete this task and for interpreting the harm caused in the network, given by a 'critical value' to check whether the infection can be cured or not. We have tested our simulation model on metabolic pathways involved in Type I Diabetes mellitus in Homo sapiens. For validating our results biologically, we have used sensitivity analysis, both local and global, as well as for identifying the role of feedbacks in spreading infection in metabolic pathways. Moreover, information in literature has also been used to validate the results. The metabolic network datasets have been collected from the Kyoto Encyclopedia of Genes and Genomes (KEGG).