Amino Acids[JOURNAL]
Sun
200 papers
Amino acid-stimulated insulin secretion: a path forward in type 2 diabetes.
Kolic J, Sun WG, Johnson JD … +1 more , Guess N
Amino Acids · 2023 Dec · PMID 37966501 · Publisher ↗
Qualitative and quantitatively appropriate insulin secretion is essential for optimal control of blood glucose. Beta-cells of the pancreas produce and secrete insulin in response to glucose and non-glucose stimuli includ...
Qualitative and quantitatively appropriate insulin secretion is essential for optimal control of blood glucose. Beta-cells of the pancreas produce and secrete insulin in response to glucose and non-glucose stimuli including amino acids. In this manuscript, we review the literature on amino acid-stimulated insulin secretion in oral and intravenous in vivo studies, in addition to the in vitro literature, and describe areas of consensus and gaps in understanding. We find promising evidence that the synergism of amino acid-stimulated insulin secretion could be exploited to develop novel therapeutics, but that a systematic approach to investigating these lines of evidence is lacking. We highlight evidence that supports the relative preservation of amino acid-stimulated insulin secretion compared to glucose-stimulated insulin secretion in type 2 diabetes, and make the case for the therapeutic potential of amino acids. Finally, we make recommendations for research and describe the potential clinical utility of nutrient-based treatments for type 2 diabetes including remission services.
A novel antibacterial approach of Cecropin-B peptide loaded on chitosan nanoparticles against MDR Klebsiella pneumoniae isolates.
Okasha H, Dahroug H, Gouda AE … +1 more , Shemis MA
Amino Acids · 2023 Dec · PMID 37966500 · Full text
Egypt has witnessed the emergence of multidrug-resistant (MDR) Klebsiella pneumoniae, which has posed a serious healthcare challenge. The proper treatment choice for MDR-KP infections is not well determined which renders...
Egypt has witnessed the emergence of multidrug-resistant (MDR) Klebsiella pneumoniae, which has posed a serious healthcare challenge. The proper treatment choice for MDR-KP infections is not well determined which renders the problem more complicated, thus making the control of such infections a serious challenge for healthcare professionals. This study aims to encapsulate the cationic antimicrobial peptide; Cecropin-B (Cec-B), to increase its lifetime, drug targeting, and efficacy and study the antimicrobial effect of free and encapsulated recombinant rCec-B peptide on multidrug-resistant K. pneumoniae (MDR-KP) isolates. Fifty isolates were collected from different clinical departments at Theodore Bilharz Research Institute. Minimal inhibitory concentrations (MICs) of rCec-B against MDR-KP isolates were determined by the broth microdilution test. In addition, encapsulation of rCec-B peptide into chitosan nanoparticles and studying its bactericidal effect against MDR-KP isolates were also performed. The relative expression of efflux pump and porin coding genes (ArcrB, TolC, mtdK, and Ompk35) was detected by quantitative PCR in treated MDR-KP bacterial isolates compared to untreated isolates. Out of 60 clinical MDR isolates, 50 were MDR-KP. 60% of the isolates were XDR while 40% were MDR. rCec-B were bactericidal on 21 isolates, then these isolates were subjected to treatment using free nanocapsule in addition to the encapsulated peptide. Free capsules showed a mild cytotoxic effect on MDR-KP at the highest concentration. MIC of encapsulated rCec-B was higher than the free peptide. The expression level of genes encoding efflux and porin (ArcrB, TolC, mtdK, and Ompk35) was downregulated after treatment with encapsulated rCec-B. These findings indicate that encapsulated rCec-B is a promising candidate with potent antibacterial activities against drug-resistant K. pneumoniae.
Safety assessment of L-Arg oral intake in healthy subjects: a systematic review of randomized control trials.
Kuramochi Y, Murata M, Sumino A … +2 more , Sone H, Hayamizu K
Amino Acids · 2023 Dec · PMID 37947893 · Full text
L-Arg is a nonessential amino acid but has many physiological roles. Accordingly, L-Arg has been used in various fields, but there is only limited information available about its safety upon overdose. Generally, the no-o...
L-Arg is a nonessential amino acid but has many physiological roles. Accordingly, L-Arg has been used in various fields, but there is only limited information available about its safety upon overdose. Generally, the no-observed adverse effect level (NOAEL) is used when setting the upper amount for chemical substances. Recently, systematic reviews have been used to assess the safety as well as the effectiveness and usefulness of them. Therefore, we conducted an assessment of the safety of the oral intake of L-Arg in healthy subjects using gastrointestinal symptoms as an index. We limited the study design to only double-blind randomized controlled trials and searched PubMed, Cochrane Library, EBSCOhost, and Ichushi-Web from inception until May 2021. Assessment of the quality of studies was conducted using the Cochrane Collaboration tool and Jadad score, and the random effects model was used for data analysis. Ultimately, 34 studies were selected for inclusion in this work. The dosage of L-Arg used in the studies ranged from 2000 to 30,000 mg/day (or/one-time dose), and the treatment duration was 1-84 days. The increased risk of gastrointestinal symptoms associated with L-Arg intake from 23 studies (647 participants in total) in which such symptoms were reported was 0.01 (95% confidence interval: - 0.02-0.04), which was not significant difference. NOAEL was estimated as 7531 mg/ one-time dose using a weighted change-point regression model (UMIN000046133).Registration and protocol: Umin.ac.jp as UMIN000046133.
Potential of milk-derived bioactive peptides as antidiabetic, antihypertensive, and xanthine oxidase inhibitors: a comprehensive bibliometric analysis and updated review.
Bellaver EH, Kempka AP
Amino Acids · 2023 Dec · PMID 37938416 · Publisher ↗
Bioactive peptides consist of small protein fragments, which are inactive in their original conformation, and they become active when released from these through enzymatic hydrolysis or fermentation processes. The bioact...
Bioactive peptides consist of small protein fragments, which are inactive in their original conformation, and they become active when released from these through enzymatic hydrolysis or fermentation processes. The bioactivity of such peptides has been extensively reported in the literature as contributors to organic homeostasis processes, as well as in immunomodulation, organism defense against oxidative processes, among others. In this study, reports of the activity of BPs isolated from milk with the potential glycemic control, antihypertensive activity, and inhibitors of uric acid formation were compiled. A systematic literature review and bibliometric analysis were conducted, using the PICO strategy for the research. The temporal analysis of publications revealed a growing interest in the investigation of bioactive peptides with potential antidiabetic, antihypertensive, and xanthine oxidase inhibitory activities, using dairy sources as products for their extraction. The literature analysis also revealed an increase in research involving non-bovine dairy products for bioactive peptide extraction. The collaboration network among authors exhibited weaknesses in scientific cooperation. Regarding the analysis of keywords, the usage of terms such as "bioactive peptides", "antioxidant", "antihypertensive", and "diabetes" was evident, constituting the main research clusters. Peptides with low molecular weight, typically < 10 kDa, of hydrophobic nature with aliphatic and aromatic chains, have significant implications in molecular interactions for the required activities. Although there is a growing interest in the industry regarding the utilization of bioactive peptides as potential drugs, there is a need to address gaps related to elucidating their interactions with cellular targets and their use in human therapy.
Investigating molecular interactions between human transferrin and resveratrol through a unified experimental and computational approach: Role of natural compounds in Alzheimer's disease therapeutics.
Khan MS, Furkan M, Shahwan M … +4 more , Yadav DK, Anwar S, Khan RH, Shamsi A
Amino Acids · 2023 Dec · PMID 37926707 · Publisher ↗
Disruptions to iron metabolism and iron homeostasis have emerged as significant contributors to the development and progression of Alzheimer's disease (AD). Human transferrin plays a key part in maintaining iron equilibr...
Disruptions to iron metabolism and iron homeostasis have emerged as significant contributors to the development and progression of Alzheimer's disease (AD). Human transferrin plays a key part in maintaining iron equilibrium throughout the body, highlighting its importance in AD. Many plant-derived compounds and dietary constituents show promise for preventing AD. Polyphenols that are abundant in fruits, vegetables, teas, coffee, and herbs possess neuroprotective attributes. Resveratrol is a natural polyphenol present in various plant sources like grapes, berries, peanuts, and red wine that has garnered research interest due to its wide range of biological activities. Notably, resveratrol exhibits neuroprotective effects that may help prevent or treat AD through multiple mechanisms. In the present study, we employed a combination of molecular docking and all-atom molecular dynamic simulations (MD) along with experimental approaches to unravel the intricate interactions between transferrin and resveratrol deciphering the binding mechanism. Through molecular docking analysis, it was determined that resveratrol occupies the iron binding pocket of transferrin. Furthermore, MD simulations provided a more profound insight into the stability and conformational dynamics of the complex suggesting that the binding of resveratrol introduced localized flexibility, while maintaining overall stability. The spectroscopic observations yielded clear evidence of substantial binding between resveratrol and transferrin, confirming the computational findings. The identified binding mechanism and conformational stability hold potential for advancing the development of innovative therapeutic approaches targeting AD through resveratrol, particularly concerning iron homeostasis. These insights serve as a platform for considering the natural compounds in the realm of AD therapeutics.
Altered kynurenine pathway metabolism and association with disease activity in patients with systemic lupus.
Eryavuz Onmaz D, Tezcan D, Yilmaz S … +2 more , Onmaz M, Unlu A
Amino Acids · 2023 Dec · PMID 37925676 · Publisher ↗
Systemic lupus erythematosus (SLE) is an autoimmune disease accompanied by increased release of proinflammatory cytokines that are known to activate the indoleamine 2,3-dioxygenase (IDO-1) enzyme, which catalyzes the rat...
Systemic lupus erythematosus (SLE) is an autoimmune disease accompanied by increased release of proinflammatory cytokines that are known to activate the indoleamine 2,3-dioxygenase (IDO-1) enzyme, which catalyzes the rate-limiting step of the kynurenine pathway (KP). This study aimed to measure KP metabolite levels in patients with SLE and investigate the relationship between disease activity, clinical findings, and KP. The study included 100 patients with SLE and 100 healthy controls. Serum tryptophan (TRP), kynurenine (KYN), kynurenic acid (KYNA), 3-hydroxyanthranilic acid (3HAA), 3-hydroxykynurenine (3HK), quinolinic acid (QA) concentrations were measured with tandem mass spectrometry. Serum KYN, KYNA, 3HAA, 3HK, and QA levels of the patients with SLE were significantly higher than the control group. Serum QA levels were elevated in patients with neurological involvement (four patients with peripheral neuropathy and two patients with mononeuropathy), serum KYN levels and KYN/TRP ratio increased in patients with joint involvement, and serum KYN, 3HK, and 3HAA levels and the KYN/TRP ratio were increased in patients with renal involvement. Moreover, KYN and KYN/TRP ratios were positively correlated with the disease activity score. These findings indicated that imbalances in KP metabolites may be associated with the pathogenesis, activation, and clinical manifestations of SLE.
Exploring details about structure requirements based on antioxidant tripeptide derived from β-Lactoglobulin by in silico approaches.
Wang F, Wen M, Zhou B
Amino Acids · 2023 Dec · PMID 37917178 · Publisher ↗
β-Lactoglobulin is one of the proteins in milk possessing antioxidant activity. The peptides derived from β-Lactoglobulin exhibit higher antioxidant activities than the most commonly used antioxidant. Furthermore, the de...
β-Lactoglobulin is one of the proteins in milk possessing antioxidant activity. The peptides derived from β-Lactoglobulin exhibit higher antioxidant activities than the most commonly used antioxidant. Furthermore, the detailed structure-activity relationship of these antioxidant peptides has not been elucidated. Therefore, in the present work, two-dimensional quantitative structure-activity relationship (2D-QSAR) and three-dimensional quantitative structure-activity relationship (3D-QSAR) models were constructed to investigate the structural factors affecting activities and gave information for the rational design of novel antioxidant peptides. After calculation and screening of molecular descriptors, linear and nonlinear models were developed by multiple linear regression (MLR), partial least squares regression (PLSR) and support vector machines (SVM) approaches. The statistical parameters are as follows: R = 0.643, Q = 0.553/MLR, R = 0.612, Q = 0.5278/PLSR, R = 0.7085, Q = 0.6887/SVM, indicating that the SVM model is superior to the MLR and PLSR models. In addition, in the 3D-QSAR models, the Dragon-CoMFA (R = 0.537, R = 0.5201) and Dragon-CoMSIA (R = 0.665, R = 0.6489) methods were conducted to predict the antioxidant activities. Comparison of statistical parameters illustrates that the suitability of Dragon-CoMSIA is superior to the Dragon-CoMFA model. The results show the robustness and excellent prediction of the proposed models, and would be applied for modifying and designing novel and potent antioxidant peptides.
Effect of lipopeptide extracted from Bacillus licheniformis on the expression of bap and luxI genes in multi-drug-resistant Acinetobacter baumannii and Pseudomonas aeruginosa.
Ghanipour F, Nazari R, Aghaei SS … +1 more , Jafari P
Amino Acids · 2023 Dec · PMID 37907777 · Publisher ↗
Recently, opportunistic pathogens like Acinetobacter baumannii and Pseudomonas aeruginosa have caused concern due to their ability to cause antibiotic resistance in weakened immune systems. As a result, researchers are a...
Recently, opportunistic pathogens like Acinetobacter baumannii and Pseudomonas aeruginosa have caused concern due to their ability to cause antibiotic resistance in weakened immune systems. As a result, researchers are always seeking efficient antimicrobial agents to tackle this issue. The hypothesis of the recent study was that probiotic products derived from bacteria would be effective in reducing drug resistance in other bacteria. This research aimed to investigate the antimicrobial properties of probiotic products from various bacterial strains, including Lactobacillus rhamnosus, Pediococcus acidilactisi, Bacillus coagulans, Bacillus subtilis, and Bacillus licheniformis. These were tested against multi-drug-resistant (MDR) standard strains A. baumannii and P. aeruginosa. B. licheniformis was found to be the most effective probiotic strain, possessing the LanA and LanM lantibiotic genes. The lipopeptide nature of the probiotic product was confirmed through high-performance liquid chromatography (HPLC) and Fourier-transform infrared spectroscopy (FTIR) techniques. The anti-biofilm and antimicrobial properties of this probiotic were measured using an SEM electron microscope and minimum inhibitory concentration (MIC) test. Real-time PCR (qPCR) was used to compare the expression of bap and luxI genes, which are considered virulence factors of drug-resistant bacteria, before and after treatment with antimicrobial agents. The MIC results showed that the probiotic product prevented the growth of bacteria at lower concentrations compared to antibiotics. In addition, the ΔΔCqs indicated that gene expression was significantly down-regulated following treatment with the obtained probiotic product. It was found that B. licheniformis probiotic products could reduce drug resistance in other bacteria, making it a potential solution to antibiotic resistance.
Acetylcholine hydrolytic activity of fibrillated β-amyloid (1-40) peptide.
Sanchis I, Spinelli R, Siano A
Amino Acids · 2023 Dec · PMID 37904049 · Publisher ↗
Alzheimer's disease is characterized by the presence of senile plaques composed of β-amyloid peptide (Aβ) aggregates with toxic effects that are still not fully understood. Recently, it was discovered that Aβ(1-42) fibri...
Alzheimer's disease is characterized by the presence of senile plaques composed of β-amyloid peptide (Aβ) aggregates with toxic effects that are still not fully understood. Recently, it was discovered that Aβ(1-42) fibrils possess catalytic activity on acetylcholine hydrolysis. Catalytic amyloids are an emerging and exciting field of research. In this study, we examined the catalytic activity of the fibrils formed by Aβ(1-40), the most abundant Aβ variant, on acetylcholine hydrolysis. Our findings reveal that Aβ(1-40) fibrils exhibit moderate enzymatic activity, indicating that natural peptide aggregates could serve as biocatalysts and provide new insights into the potential role of Aβ in neurological disorders.
Predicted novel hypertrehalosaemic peptides of cockroaches are verified by mass spectrometry.
Marco HG, König S, Gäde G
Amino Acids · 2023 Nov · PMID 37882863 · Full text
Small neuropeptides from the corpora cardiaca are responsible in cockroaches for the mobilisation of trehalose from the fat body into the haemolymph. Such hypertrehalosaemic hormones (HrTHs) belong to the large family of...
Small neuropeptides from the corpora cardiaca are responsible in cockroaches for the mobilisation of trehalose from the fat body into the haemolymph. Such hypertrehalosaemic hormones (HrTHs) belong to the large family of insect adipokinetic hormones (AKHs); a few HrTHs were previously sequenced from cockroaches, and from genomic and/or transcriptomic information one may predict the genes encoding HrTHs from more species. Definite elucidation of the primary structure of the mature peptide with putative modifications needs analytical chemical methods. In the current study, we use high-resolution mass spectrometry coupled with liquid chromatography to identify unequivocally the HrTHs of 13 cockroach species. Either genomic/transcriptomic information was available for most of the species examined, or from related species. We confirm predicted novel sequences and find hydroxyproline modification for the majority of the peptides. The novel decapeptides are structurally close to Bladi-HrTH, which is found in all seven of the investigated blaberid subfamilies. Bladi-HrTH and all the novel peptides elicit a hypertrehalosaemic response in Periplaneta americana, a blattid cockroach.
Serum albumin acted as an effective carrier to improve the stability of bioactive flavonoid.
Yang YD, Lu N, Tian R
Amino Acids · 2023 Dec · PMID 37856004 · Publisher ↗
The health-improving functions of bioactive flavonoids in vitro and in vivo are often limited by their low stability, which could be counteracted by the application of proteins as carriers of flavonoids. Clarification of...
The health-improving functions of bioactive flavonoids in vitro and in vivo are often limited by their low stability, which could be counteracted by the application of proteins as carriers of flavonoids. Clarification of the mechanism of protein-ligand interaction is crucial for the encapsulation of bioactive components. Herein, common plasma proteins [i.e., bovine serum albumin (BSA), human serum albumin (HSA), human immunoglobulin G (IgG) and fibrinogen (FG)] were compared for their binding characteristics to quercetin, the main component of flavonoids in human diet, in the absence and presence of free Cu (an accelerator for flavonoids' instability) using multi-spectroscopic and computational methods. As a flexible open structure of proteins, both BSA and HSA were found to be the most promising carriers for quercetin and Cu with an affinity on the order of 10 M. HSA-diligand complex (i.e., HSA-quercetin-Cu) was successfully generated when both quercetin and Cu were added to the HSA solution. The stability and free radical scavenging activity of bioactive quercetin during incubation was promoted in the HSA-diligand complex relative to quercetin-Cu complex. Quercetin/Cu system could induce the formation of reactive oxygen species such as hydrogen peroxide (HO) and hydroxide radical (·OH), which were significantly suppressed upon HSA binding. Consistently, the cytotoxicity of the quercetin/Cu system to endothelial cells was reduced in the HSA-diligand complex. These results demonstrate the possibility of developing serum albumin-based carriers for the protection of bioactive flavonoids in their nutritional application.
Cross species review of the physiological role of D-serine in translationally relevant behaviors.
Arizanovska D, Emodogo JA, Lally AP … +3 more , Palavicino-Maggio CB, Liebl DJ, Folorunso OO
Amino Acids · 2023 Nov · PMID 37833512 · Full text
Bridging the gap between preclinical models of neurological and psychiatric disorders with their human manifestations is necessary to understand their underlying mechanisms, identify biomarkers, and develop novel therape...
Bridging the gap between preclinical models of neurological and psychiatric disorders with their human manifestations is necessary to understand their underlying mechanisms, identify biomarkers, and develop novel therapeutics. Cognitive and social impairments underlie multiple neuropsychiatric and neurological disorders and are often comorbid with sleep disturbances, which can exacerbate poor outcomes. Importantly, many symptoms are conserved between vertebrates and invertebrates, although they may have subtle differences. Therefore, it is essential to determine the molecular mechanisms underlying these behaviors across different species and their translatability to humans. Genome-wide association studies have indicated an association between glutamatergic gene variants and both the risk and frequency of psychiatric disorders such as schizophrenia, bipolar disorder, and autism spectrum disorder. For example, changes in glutamatergic neurotransmission, such as glutamate receptor subtype N-methyl-D-aspartate receptor (NMDAR) hypofunction, have been shown to contribute to the pathophysiology of schizophrenia. Furthermore, in neurological disorders, such as traumatic brain injury and Alzheimer's disease, hyperactivation of NMDARs leads to synaptic damage. In addition to glutamate binding, NMDARs require the binding of a co-agonist D-serine or glycine to the GluN1 subunit to open. D-serine, which is racemized from L-serine by the neuronal enzyme serine racemase (SRR), and both SRR and D-serine are enriched in cortico-limbic brain regions. D-serine is critical for complex behaviors, such as cognition and social behavior, where dysregulation of its synthesis and release has been implicated in many pathological conditions. In this review, we explore the role of D-serine in behaviors that are translationally relevant to multiple psychiatric and neurological disorders in different models across species.
Mucosal-associated invariant T cells display both pathogenic and protective roles in patients with inflammatory bowel diseases.
Wei L, Chen Z, Lv Q
Amino Acids · 2023 Dec · PMID 37819474 · Publisher ↗
An important subtype of the innate-like T lymphocytes is mucosal-associated invariant T (MAIT) cells expressing a semi-invariant T cell receptor α (TCR-α) chain. MAIT cells could be activated mainly by TCR engagement or...
An important subtype of the innate-like T lymphocytes is mucosal-associated invariant T (MAIT) cells expressing a semi-invariant T cell receptor α (TCR-α) chain. MAIT cells could be activated mainly by TCR engagement or cytokines. They have been found to have essential roles in various immune mediated. There have been growing preclinical and clinical findings that show an association between MAIT cells and the physiopathology of inflammatory bowel diseases (IBD). Of note, published reports demonstrate contradictory findings regarding the role of MAIT cells in IBD patients. A number of reports suggests a protective effect, whereas others show a pathogenic impact. The present review article aimed to explore and discuss the findings of experimental and clinical investigations evaluating the effects of MAIT cells in IBD subjects and animal models. Findings indicate that MAIT cells could exert opposite effects in the course of IBD, including an anti-inflammatory protective effect of blood circulating MAIT cells and an effector pathogenic effect of colonic MAIT cells. Another important finding is that blood levels of MAIT cells can be considered as a potential biomarker in IBD patients.
Binding of berberine to PEBP1 synergizes with sorafenib to induce the ferroptosis of hepatic stellate cells.
Xie Z, Zhou Y, Lin M … +1 more , Huang C
Amino Acids · 2023 Dec · PMID 37814030 · Publisher ↗
Hepatic stellate cell (HSC) activation is the key process in hepatic fibrosis (HF) development. Targeted death of HSCs could be effective in the prevention and treatment of HF. Phosphatidylethanolamine-binding protein (P...
Hepatic stellate cell (HSC) activation is the key process in hepatic fibrosis (HF) development. Targeted death of HSCs could be effective in the prevention and treatment of HF. Phosphatidylethanolamine-binding protein (PEBP)1 can trigger ferroptosis by mediating peroxide production, but how it modulates HSC ferroptosis is not known. We screened natural small molecules that could bind with PEBP1, and investigated the mechanism by which it promotes HSC ferroptosis. The maximum binding energy of berberine with PEBP1 was - 8.51 kcal/mol, indicating that berberine could bind strongly with PEBP1. Berberine binding to PEBP1 could promote HSC ferroptosis via synergy of its actions with those of sorafenib, but it could not induce ferroptosis alone. Combined administration of berberine enhanced the ferroptotic effects of low-dose sorafenib upon HSCs. Herein, we revealed that PEBP1 might be a target that could enhance the effects of sorafenib, which could provide a new therapeutic approach for HF treatment.
The possibilities of LOXL4 as a prognostic marker for carcinomas.
Wang J, Chen C, Huang J … +5 more , Xie Z, Chen X, Zheng Z, Li E, Zou H
Amino Acids · 2023 Nov · PMID 37814029 · Publisher ↗
Lysyl oxidase-like 4 (LOXL4), a member of lysyl oxidase family, is a copper and lysine tyrosylquinone-dependent amine oxidase that serves the role of catalyzing the cross-linking of elastin and collagen in the extracellu...
Lysyl oxidase-like 4 (LOXL4), a member of lysyl oxidase family, is a copper and lysine tyrosylquinone-dependent amine oxidase that serves the role of catalyzing the cross-linking of elastin and collagen in the extracellular matrix. Numerous studies have shown a significant association between LOXL4 expression levels and tumor proliferation, migration, invasion and patients' prognosis and overall survival in different types of tumors. Here we review their relationship and the molecular pathogenesis behind them, aiming to explore the possibilities of LOXL4 as a prognostic marker for diverse carcinomas and provide some indications for further research in this field.
Common pathogenic bacteria-induced reprogramming of the host proteinogenic amino acids metabolism.
Li XY, Zeng ZX, Cheng ZX … +4 more , Wang YL, Yuan LJ, Zhai ZY, Gong W
Amino Acids · 2023 Nov · PMID 37814028 · Full text
Apart from cancer, metabolic reprogramming is also prevalent in other diseases, such as bacterial infections. Bacterial infections can affect a variety of cells, tissues, organs, and bodies, leading to a series of clinic...
Apart from cancer, metabolic reprogramming is also prevalent in other diseases, such as bacterial infections. Bacterial infections can affect a variety of cells, tissues, organs, and bodies, leading to a series of clinical diseases. Common Pathogenic bacteria include Helicobacter pylori, Salmonella enterica, Mycobacterium tuberculosis, Staphylococcus aureus, and so on. Amino acids are important and essential nutrients in bacterial physiology and support not only their proliferation but also their evasion of host immune defenses. Many pathogenic bacteria or opportunistic pathogens infect the host and lead to significant changes in metabolites, especially the proteinogenic amino acids, to inhibit the host's immune mechanism to achieve its immune evasion and pathogenicity. Here, we review the regulation of host metabolism, while host cells are infected by some common pathogenic bacteria, and discuss how amino acids of metabolic reprogramming affect bacterial infections, revealing the potential adjunctive application of amino acids alongside antibiotics.
The renoprotective effects of taurine against diabetic nephropathy via the p38 MAPK and TGF-β/Smad2/3 signaling pathways.
Ural C, Celik A, Ozbal S … +6 more , Guneli E, Arslan S, Ergur BU, Cavdar C, Akdoğan G, Cavdar Z
Amino Acids · 2023 Nov · PMID 37805666 · Publisher ↗
Diabetic nephropathy (DN), a severe diabetes complication, causes kidney morphological and structural changes due to extracellular matrix accumulation. This accumulation is caused mainly by oxidative stress. Semi-essenti...
Diabetic nephropathy (DN), a severe diabetes complication, causes kidney morphological and structural changes due to extracellular matrix accumulation. This accumulation is caused mainly by oxidative stress. Semi-essential amino acid derivative taurine has powerful antioxidant and antifibrotic effects. The aim of this study was to investigate the renoprotective effects of taurine through its possible roles in oxidative stress, extracellular matrix proteins, and the signaling pathways associated with the accumulation of extracellular matrix proteins in DN rats. 29 Wistar albino rats were randomly separated into control, taurine, diabetes, and diabetes + taurine groups. Diabetes animals were injected 45 mg/kg streptozosine. Taurine is given by adding to drinking water as 1% (w/v). Urine, serum, and kidney tissue were collected from rats for biochemical and histological analysis after 12 weeks. According to the studies, taurine significantly reduces the levels of malondialdehyde (MDA), total oxidant status (TOS), and protein expression of NADPH oxidase 4 (NOX4) that increase in diabetic kidney tissue. Also, decreased superoxide dismutase (SOD) activity levels significantly increased with taurine in diabetic rats. Moreover, increased mRNA and protein levels of fibronectin decreased with taurine. The matrix metalloproteinase (MMP)-2 and MMP-9 activities and their mRNA levels increased significantly, and this increase was significantly summed with taurine. There was a decrease in mRNA expression of Extracellular matrix metalloproteinase inducer (EMMPRIN). Taurine significantly increased this decrease. Diabetes increased mRNA expressions of transforming growth factor (TGF)-β and Smad2/3. Taurine significantly reduced this induction. TGF-β protein expression, p38, and Smad2/3 activations were also inhibited, but taurine was suppressed significantly. All these findings indicate that taurine may be an effective practical strategy to prevent renal diabetic injury.
Bromelain and ficin proteolytic effects on gliadin cytotoxicity and expression of genes involved in cell-tight junctions in Caco-2 cells.
Mousavi Maleki MS, Aghamirza Moghim Ali Abadi H, Vaziri B … +4 more , Shabani AA, Ghavami G, Madanchi H, Sardari S
Amino Acids · 2023 Nov · PMID 37803248 · Publisher ↗
Enzyme therapy for celiac disease (CeD), which digests gliadin into non-immunogenic and non-toxic peptides, can be an appropriate treatment option for CeD. Here, we have investigated the effectiveness of bromelain and fi...
Enzyme therapy for celiac disease (CeD), which digests gliadin into non-immunogenic and non-toxic peptides, can be an appropriate treatment option for CeD. Here, we have investigated the effectiveness of bromelain and ficin on gliadin digestion using in vitro, such as SDS-PAGE, HPLC, and circular dichroism (CD). Furthermore, the cytotoxicity of gliadin and 19-mer peptide before and after digestion with these enzymes was evaluated using the MTT assay in the Caco-2 cell line. Finally, we examined the effect of these treatments along with Larazotide Acetate on the expression of genes involved in cell-tight junctions, such as Occludin, Claudin 3, tight junction protein-1, and Zonulin in the Caco-2 cell line. Our study demonstrated bromelain and ficin digestion effects on the commercial and wheat-extracted gliadin by SDS-PAGE, HPLC, and CD. Also, the cytotoxicity results on Caco-2 showed that toxicity of the gliadin and synthetic 19-mer peptide was decreased by adding bromelain and ficin. Furthermore, the proteolytic effects of bromelain and ficin on gliadin indicated the expression of genes involved in cell-tight junctions was improved. This study confirms that bromelain and ficin mixture could be effective in improving the symptoms of CeD.
Synthesis and screening for anticancer activity of two novel telluro-amino acids: 1,3-Tellurazolidine-4-carboxylic acid and tellurohomocystine.
Tripathi A, Khan A, Srivastava R
Amino Acids · 2023 Oct · PMID 37796355 · Publisher ↗
Tellurium (Te) containing amino acids and their derivatives have the potential to participate in biological processes, which are currently being studied extensively to understand the function of Te in biological and phar...
Tellurium (Te) containing amino acids and their derivatives have the potential to participate in biological processes, which are currently being studied extensively to understand the function of Te in biological and pharmacological activities. Here, we are reporting the synthesis of two novel Te-containing unnatural amino acids; 1,3-Tellurazolidine-4-carboxylic acid [Te{CHCH(COOH)NHCH}] 5, and 4,4'-(1,2-Ditellurdiyl)bis(2-aminobutanoic acid), i.e., tellurohomocystine [TeCHCHCH(NH)COOH] 7, synthesized from tellurocystine, and L-methionine as precursors, respectively. These telluro-amino acids were thoroughly characterized by multinuclear (H, C, Te) NMR spectroscopy, high-resolution ESI-mass spectrometry (ESI-MS), and elemental analysis. The telluro-amino acids 5 and 7 demonstrated good biocompatibility when in vitro cytotoxicity was analyzed on two fibroblast cell lines L929 and NIH/3T3. The treatment of telluro-amino acids 1,3-Tellurazolidine-4-carboxylic acid 5 and tellurohomocystine 7 on breast cancer cell line MCF-7 showed anticancer activity with IC50 values of 7.29 ± 0.27 µg/mL and 25.36 ± 0.12 µg/mL, respectively. The cell cycle distribution studies also revealed arrest at the sub-G1 phase suggesting telluro-amino acids to be apoptotic.
Peptide OA-VI12 restrains melanogenesis in B16 cells and C57B/6 mouse ear skin via the miR-122-5p/Mitf/Tyr axis.
Wang J, Li Y, Feng C … +12 more , Wang H, Li J, Liu N, Fu Z, Wang Y, Wu Y, Liu Y, Zhang Y, Yin S, He L, Wang Y, Yang X
Amino Acids · 2023 Nov · PMID 37794194 · Publisher ↗
Excessive melanogenesis leads to hyperpigmentation, which is one of the common skin conditions in humans. Existing whitening cosmetics cannot meet market needs due to their inherent limitations. Thus, the development of...
Excessive melanogenesis leads to hyperpigmentation, which is one of the common skin conditions in humans. Existing whitening cosmetics cannot meet market needs due to their inherent limitations. Thus, the development of novel skin-whitening agents continues to be a challenge. The peptide OA-VI12 from the skin of amphibians at high altitude has attracted attention due to its remarkable anti light damage activity. However, whether OA-VI12 has the skin-whitening effect of inhibiting melanogenesis is still. Mouse melanoma cells (B16) were used to study the effect of OA-VI12 on cell viability and melanin content. The pigmentation model of C57B/6 mouse ear skin was induced by UVB and treated with OA-VI12. Melanin staining was used to observe the degree of pigmentation. MicroRNA sequencing, quantitative real-time PCR (qRT-PCR), immunofluorescence analysis and Western blot were used to detect the change of factor expression. Double luciferase gene report experiment was used to prove the regulatory relationship between miRNA and target genes. OA-VI12 has no effect on the viability of B16 cells in the concentration range of 1-100 μM and significantly inhibits the melanin content of B16 cells. Topical application of OA-VI12, which exerted transdermal potency, prevented UVB-induced pigmentation of ear skin. MicroRNA sequencing and double luciferase reporter analysis results showed that miR-122-5p, which directly regulated microphthalmia-associated transcription factor (Mitf), had significantly different expression before and after treatment with OA-VI12. Mitf is a simple helix loop and leucine zipper transcription factor that regulates tyrosinase (Tyr) expression by binding to the M-box promoter element of Tyr. qRT-PCR, immunofluorescence analysis and Western blot showed that OA-VI12 up-regulated the expression of miR-122-5p and inhibited the expression of Mitf and Tyr. The effects of OA-VI12 on melanogenesis inhibition in vitro and in vivo may involve the miR-122-5p/Mitf/tyr axis. OA-VI12 represents the first report on a natural amphibian-derived peptide with skin-whitening capacity and the first report of miR-122-5p as a target for regulating melanogenesis, thereby demonstrating its potential as a novel skin-whitening agent and highlighting amphibian-derived peptides as an underdeveloped resource.
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