Branched chain amino acids, as essential amino acids, can be used to synthesize nitrogen-containing compounds and also act as signal molecules to regulate substance metabolism. Studies have shown that the elevated level of branched chain amino acids is closely related to insulin resistance and type 2 diabetes. It can affect insulin signal transduction by activating mammalian target of rapamycin (mTOR) signal pathway, and regulate insulin resistance by damaging lipid metabolism and affecting mitochondrial function. In addition, abnormal catabolism of branched amino acids can lead to the accumulation of metabolic intermediates, such as branched chain α-keto acids, 3-hydroxyisobutyrate and β-aminoisobutyric acid. Branched chain α-keto acids and 3-hydroxyisobutyrate can induce insulin resistance by affecting insulin signaling pathway and damaging lipid metabolism. β-aminoisobutyric acid can improve insulin resistance by reducing lipid accumulation and inflammatory reaction and enhancing fatty acid oxidation. This paper systematically reviewed the regulatory effects and mechanisms of branched chain amino acids and their metabolic intermediates on insulin resistance, which will provide a new direction for the prevention and treatment of insulin resistance and type 2 diabetes.
Humans ; Amino Acids, Branched-Chain/metabolism* ; Insulin Resistance/physiology* ; Diabetes Mellitus, Type 2 ; Insulin/pharmacology* ; Keto Acids/metabolism*

Objective: To investigate the clinical significance of endothelin A receptor (ETAR) expression in high-grade serous ovarian carcinoma (HGSOC). To design ETAR carboxyl terminal (ETAR-C) amino acids derived polypeptide and to study the inhibitory effect on ovarian epithelial carcinoma cells in vitro. Methods: (1) A total of 126 patients who received surgical treatment and were diagnosed with HGSOC by postoperative pathological examination in Central Hospital of Xuzhou from January 1, 2007 to December 31, 2017 were selected. All patients had completed clinicopathological data and follow-up data. Cancer tissue samples were collected and ETAR mRNA expression in HGSOC tissues was detected by reverse transcript-PCR. The clinical significance was analyzed. (2) ETAR-C fusion polypeptide was designed based on the sequence of carboxyl terminal amino acids of ETAR, expressed and purified in vitro. The effects of ETAR-C fusion polypeptide on migration and invasion ability of ovarian cancer SKOV3 and CAOV3 cells were detected by scratch test and invasion test, respectively. The effect of ETAR-C fusion polypeptide on chemosensitivity of cisplatin-resistant ovarian cancer SKOV3/cDDP and CAOV3/cDDP cells was determined by methyl thiazolyl tetrazolium (MTT) colorimetric assay. The effect of ETAR-C fusion polypeptide on β-arrestin-1 expression in ovarian cancer SKOV3 and CAOV3 cells was detected by western blot. Results: (1) The relative expression level of ETAR mRNA in HGSOC tissues was 18.6±5.1. Patients with HGSOC were divided into high ETAR mRNA expression (n=76) and low ETAR mRNA expression (n=50) with 61.7% as cut-off value analyzed by X-Tile software. High expression of ETAR mRNA was significantly correlated with abdominal water volume, platinum drug resistance, and cancer antigen 125 (CA₁₂₅) value in HGSOC patients (all P<0.05), but was not related to the age of patients with HGSOC and the size of postoperative residual lesions (all P>0.05). The 5-year progression free survival rates were 18.4% and 28.0%, and the 5-year overall survival rates were 38.2% and 52.0% in HGSOC patients with high and low ETAR mRNA expression respectively, there were statistically significant differences (P=0.046, P=0.034). (2) The results of scratch test and invasion test showed that the scratch healing rate and cell invasion rate of SKOV3 or CAOV3 cells treated with endothelin-1 (ET-1) and ET-1+ETAR-C were respectively compared, and the differences were statistically significant (all P<0.05). MTT assay showed that the inhibition rates of ETAR-C fusion polypeptide treated in SKOV3/cDDP and CAOV3/cDDP cells were significantly higher than those of control cells after the addition of 4, 6, 8, 10, 12, and 24 μg/ml cisplatin (all P<0.05). Western blot analysis showed that the relative expression levels of β-arrestin-1 in SKOV3 or CAOV3 cells treated with ET-1 and ET-1+ETAR-C were 1.85±0.09 and 1.13±0.09 (SKOV3 cells), 2.14±0.15 and 1.66±0.12 (CAOV3 cells), respectively. The differences were statistically significant (all P<0.05). Conclusions: The prognosis of HGSOC patients with high expression of ETAR mRNA is significantly worse than those with low expression of ETAR mRNA. ETAR might be a new target for HGSOC treatment. The ETAR-C fusion polypeptide that interferes with the interaction of ETAR and β-arrestin-1 has good inhibitory effect on ovarian cancer cells in vitro, and might have clinical application potential.
Female ; Humans ; Amino Acids/therapeutic use* ; beta-Arrestins/therapeutic use* ; Cell Line, Tumor ; Cisplatin/pharmacology* ; Clinical Relevance ; Ovarian Neoplasms/pathology* ; Receptor, Endothelin A/therapeutic use* ; RNA, Messenger/metabolism*

A hyperuricemic rat model induced by adenine and ethambutol was established to investigate the anti-hyperuricemia activity and its mechanism of the flavonoid extract from saffron floral bio-residues. Sixty-seven SD rats were randomly divided into control group, model group, positive control group, and flavonoid extract groups(with 3 doses), respectively, and each group contained 11 or 12 rats. The hyperuricemic model was established by continuous oral administration of adenine(100 mg·kg~(-1)) and ethambutol(250 mg·kg~(-1)) for 7 days. At the same time, the positive control group was given allopurinol(20 mg·kg~(-1) per day) and the flavonoid extract groups were given the flavonoid extract at doses of 340, 170 and 85 mg·kg~(-1) per day, respectively. On day 8, rat serum, liver, kidney, and intestinal tissues were collected, and the levels of uric acid in serum and tissue, the xanthine oxidase activities and antioxi-dant activities in serum and liver were evaluated, and the kidney histopathology was explored. In addition, an untargeted serum metabolomics study was performed. According to the results, the flavonoid extract effectively reduced the uric acid levels in serum, kidney and ileum and inhibited the xanthine oxidase activities and elevated the antioxidant activities of serum and liver in hyperuricemic rat. At the same time, it reduced the levels of inflammation factors in kidney and protected renal function. Moreover, 68 differential metabolites of hyperuricemic rats were screened and most of which were lipids and amino acids. The flavonoid extract significantly retrieved the levels of differential metabolites in hyperuricemic rats, such as SM(d18:1/20:0), PC[18:0/18:2(92,12Z)], palmitic acid and citrulline, possibly through the following three pathways, i.e., arginine biosynthesis, glycine, serine and threonine metabolism, and histidine metabolism. To sum up, the flavonoid extract of saffron floral bio-residues lowered the uric acid level, increased the antioxidant activity, and alleviated inflammatory symptoms of hyperuricemic rats, which may be related to its inhibition of xanthine oxidase activity and regulation of serum lipids and amino acids metabolism.
Rats ; Animals ; Flavonoids/pharmacology* ; Uric Acid ; Crocus ; Xanthine Oxidase ; Ethambutol/adverse effects* ; Rats, Sprague-Dawley ; Hyperuricemia/drug therapy* ; Kidney ; Antioxidants/pharmacology* ; Plant Extracts/adverse effects* ; Amino Acids ; Adenine/adverse effects* ; Lipids

OBJECTIVE: To investigate the role of Numb in regulating mammalian target of rapamycin (mTOR) complex 1 (mTORC1) signaling pathway. METHODS: Male BALB/C mouse models of acute kidney injury (AKI) were subjected to intravenous injections of Numb-siRNA or NC-siRNA with or without intraperitoneal cisplatin injections. After the treatments, the expressions and distribution of Numb and megalin in the renal tissues of the mice were detected with immunohistochemistry, and the renal expressions of Numb, S6, p-S6, S6K1, p-S6K1, 4EBP1 and p-4EBP1 were examined with Western blotting. The proximal renal tubular epithelial cells were isolated from the mice transfected with Numb-siRNA for in vitro culture. In NRK-52E cells, the effects of amino acid stimulation, Numb knockdown, and V1G1 overexpression, alone or in combination, on expressions of Numb, S6 and p-S6 were detected with Western blotting; the expressions of AMPK and p-AMPK were also detected in transfected NRK-52E cells, mouse kidneys and cultured mouse renal tubular epithelial cells. RESULTS: In BALB/C mice, injection of Numb-siRNA caused significant reductions of Numb and p-S6 expressions without affecting megalin expression in the renal proximal tubules (P < 0.05). Cisplatin treatment obviously upregulated p-S6K1 and p-4EBP1 expressions in the kidneys of the mice (P < 0.05), and this effect was significantly inhibited by treatment with Numb-siRNA (P < 0.05). In NRK-52E cells, amino acid stimulation significantly upregulated the expression of p-S6 (P < 0.05), which was strongly suppressed by transfection with Numb-siRNA (P < 0.05). Numb knockdown inhibited AMPK activation in NRK-52E cells, mouse kidneys and primary proximal tubular epithelial cells (P < 0.05). Numb knockdown significantly downregulated V1G1 expression in NRK-52E cells (P < 0.05), and V1G1 overexpression obviously reversed the inhibitory effect of Numb-siRNA on S6 phosphorylation (P < 0.05). CONCLUSION Numb promotes the activation of mTORC1 signaling in proximal tubular epithelial cells by upregulating V1G1 expression.
Animals ; Male ; Mice ; Amino Acids/pharmacology* ; AMP-Activated Protein Kinases/metabolism* ; Cisplatin/pharmacology* ; Epithelial Cells ; Low Density Lipoprotein Receptor-Related Protein-2/metabolism* ; Mammals/metabolism* ; Mechanistic Target of Rapamycin Complex 1/metabolism* ; Membrane Proteins/metabolism* ; Mice, Inbred BALB C ; Nerve Tissue Proteins/metabolism* ; RNA, Small Interfering/metabolism* ; Signal Transduction ; Vacuolar Proton-Translocating ATPases/metabolism*

Influenza B virus (IBV) is more likely to cause complications than influenza A virus (IAV) and even causes higher disease burden than IAV in a certain season, but IBV has received less attention. In order to analyze the genetic evolution characteristics of the clinical strain IBV (B/Guangxi-Jiangzhou/1352/2018), we constructed genetic evolution trees and analyzed the homology and different amino acids of hemagglutinin and neuraminidase referring to the vaccine strains recommended by World Health Organization (WHO). We found that strain B/Guangxi-Jiangzhou/1352/2018 was free of interlineage reassortment and poorly matched with the vaccine strain B/Colorado/06/2017 of the same year. We also determined the median lethal dose (LD₅₀) and the pathogenicity of strain B/Guangxi-Jiangzhou/1352/2018 in mice. The results showed that the LD₅₀ was 10^5.9 TCID₅₀ (median tissue culture infective dose), the IBV titer in the lungs reached peak 1 d post infection and the mRNA level of the most of inflammatory cytokines in the lungs reached peak 12 h post infection. The alveoli in the lungs were severely damaged and a large number of inflammatory cells were infiltrated post infection. The study demonstrated that the clinical strain IBV (B/Guangxi-Jiangzhou/1352/2018) could infect mice and induce typical lung inflammation. This will facilitate the research on the pathogenesis and transmission mechanism of IBV, and provide an ideal animal model for evaluation of new vaccines, antiviral and anti-inflammatory drug.
Amino Acids/genetics* ; Animals ; Antiviral Agents/pharmacology* ; China ; Cytokines/metabolism* ; Hemagglutinins/metabolism* ; Humans ; Influenza B virus/pathogenicity* ; Influenza, Human/virology* ; Mice ; Neuraminidase/genetics* ; Orthomyxoviridae Infections/virology* ; Phylogeny ; RNA, Messenger/metabolism* ; Virulence/genetics*

The ginseng endophytic bacteria F1 is a potential biocontrol agent for ginseng bacterial soft rot. In this paper,the chemotactic response of ginseng endophytic bacteria F1 on 8 kinds of sugar and amino acids was detected by capillary method to explore its biocontrol mechanism. The chemotactic response of F1 strain to 4 kinds of better chemotaxis substances such as glucose,glycine,L-rhamnoseand L-glutamic acid under parameters( concentration,time,temperature and pH) was studied. The results showed that under the same experimental conditions( incubation temperature 25 ℃,incubation time 60 min,chemotaxis concentration 1 mg·L~(-1)),ginseng endophytic bacteria F1 showed different degrees of response to the eight substances tested. The phenomenon of positive chemotaxis of the measured sugars and amino acids was obvious,and the chemotactic response to total ginsenosides was low. The degree of chemotaxis response is positively correlated with the chemotaxis index within a certain range of parameters,but as the temperature,p H,time,concentration and other factors continue to increase,the chemotaxis effect decreases,and F1 optimizes the chemotaxis of the four substances. The parameters are as follows: glucose: 25 ℃,10 mg·L~(-1),45 min,pH 7; glycine: 30 ℃,10 mg·L~(-1),75 min,pH7; L-rhamnose: 30 ℃,1 mg·L~(-1),30 min,pH 6; L-glutamic acid: 25 ℃,0. 1 mg·L~(-1),45 min,pH 8. The chemotactic response is more sensitive to low concentrations of chemotactic substances.
Amino Acids/pharmacology* ; Bacteria/drug effects* ; Chemotaxis ; Endophytes/physiology* ; Ginsenosides/pharmacology* ; Panax/chemistry* ; Plant Exudates/pharmacology* ; Sugars/pharmacology*

In this study, we evaluated the effect of the herbicide propyl 4-(2-(4,6-dimethoxypyrimidin-2-yloxy)benzylamino) benzoate (ZJ0273) on barley growth and explored the potential to trigger growth recovery through the application of branched-chain amino acids (BCAAs). Barley plants were foliar-sprayed with various concentrations of ZJ0273 (100, 500, or 1000 mg/L) at the four-leaf stage. Increasing either the herbicide concentration or measurement time after herbicide treatment significantly impaired plant morphological parameters such as plant height and biomass, and affected physiological indexes, i.e. maximal photochemical efficiency (F_v/F_m), quantum yield of photosystem II (Ф_PSII), net photosynthetic rate (P_n), and chlorophyll meter value (soil and plant analyzer development (SPAD)). Cellular injury of herbicide-treated plants was also evidenced by increased levels of reactive oxygen species (ROS) and antioxidative enzyme activity. Elevated levels of herbicide significantly reduced the activity of acetolactate synthase (ALS)-a key enzyme in the biosynthesis of BCAAs. In a separate experiment, growth recovery in herbicide-stressed barley plants was studied using various concentrations of BCAAs (10, 50, 100, and 200 mg/L). Increasing BCAA concentration in growth media significantly increased the biomass of herbicide-stressed barley seedlings, but had no significant effect on non-stressed plants. Further, BCAAs (100 mg/L) significantly down-regulated ROS and consequently antioxidant enzyme levels in herbicide-stressed plants. Our results showed that exogenous application of BCAAs could reverse the inhibitory effects of ZJ0273 by restoring protein biosynthesis in barley seedlings.
Amino Acids, Branched-Chain/administration & dosage* ; Antioxidants/metabolism* ; Benzoates/pharmacology* ; Biomass ; Chlorophyll/metabolism* ; Herbicides/pharmacology* ; Hordeum/metabolism* ; Photosynthesis/drug effects* ; Plant Leaves/metabolism* ; Reactive Oxygen Species/metabolism* ; Seedlings/metabolism*

Hypoxia (low oxygen level) is an important feature during infections and affects the host defence mechanisms. The host has evolved specific responses to address hypoxia, which are strongly dependent on the activation of hypoxia-inducible factor 1 (HIF-1). Hypoxia interferes degradation of HIF-1 alpha subunit (HIF-1α), leading to stabilisation of HIF-1α, heterodimerization with HIF-1 beta subunit (HIF-1β) and subsequent activation of HIF-1 pathway. Apical periodontitis (periapical lesion) is a consequence of endodontic infection and ultimately results in destruction of tooth-supporting tissue, including alveolar bone. Thus far, the role of HIF-1 in periapical lesions has not been systematically examined. In the present study, we determined the role of HIF-1 in a well-characterised mouse periapical lesion model using two HIF-1α-activating strategies, dimethyloxalylglycine (DMOG) and adenovirus-induced constitutively active HIF-1α (CA-HIF1A). Both DMOG and CA-HIF1A attenuated periapical inflammation and tissue destruction. The attenuation in vivo was associated with downregulation of nuclear factor-κappa B (NF-κB) and osteoclastic gene expressions. These two agents also suppressed NF-κB activation and subsequent production of proinflammatory cytokines by macrophages. Furthermore, activation of HIF-1α by DMOG specifically suppressed lipopolysaccharide-stimulated macrophage differentiation into M1 cells, increasing the ratio of M2 macrophages against M1 cells. Taken together, our data indicated that activation of HIF-1 plays a protective role in the development of apical periodontitis via downregulation of NF-κB, proinflammatory cytokines, M1 macrophages and osteoclastogenesis.
Alveolar Bone Loss ; metabolism ; prevention & control ; Amino Acids, Dicarboxylic ; pharmacology ; Animals ; Cytokines ; metabolism ; Down-Regulation ; Gene Expression ; drug effects ; Hypoxia-Inducible Factor 1, alpha Subunit ; physiology ; Macrophages ; physiology ; Mice ; NF-kappa B ; metabolism ; Osteogenesis ; physiology ; Periapical Periodontitis ; metabolism ; prevention & control ; Real-Time Polymerase Chain Reaction ; X-Ray Microtomography

Diabetic nephropathy is one of the various complications of diabetes mellitus, affecting patients for lifetime. Earlier studies have revealed that genipin can not only improve diabetes, but also induce cytotoxicity. Therefore, it is not clear which effect of genipin on kidneys occurs, when it is used in the treatment of diabetes. In the present study, we performed nuclear magnetic resonance (NMR)-based metabolomics analysis of urine and kidney tissue samples obtained from diabetic rats to explore the change of endogenous metabolites associated with diabetes and concomitant kidney disease. Nine significant differential metabolites that were closely related to renal function were screened. They were mainly related to three metabolic pathways: synthesis and degradation of ketone bodies, glycine, serine and threonine metabolism, and butanoate metabolism, which are involved in methylamine metabolism, energy metabolism and amino acid metabolism. In addition, after the intervention of genipin, the metabolic levels of all the metabolites tended to be normal, indicating a protective effect of genipin on kidneys. Our results may be helpful for understanding the antidiabetic effect of genipin.
Amino Acids ; metabolism ; Animals ; Diabetes Mellitus, Experimental ; chemically induced ; drug therapy ; metabolism ; urine ; Energy Metabolism ; drug effects ; Hypoglycemic Agents ; pharmacology ; Iridoids ; pharmacology ; Kidney ; drug effects ; metabolism ; Male ; Metabolic Networks and Pathways ; drug effects ; Metabolome ; drug effects ; Metabolomics ; Methylamines ; metabolism ; Proton Magnetic Resonance Spectroscopy ; Rats ; Rats, Sprague-Dawley

Objective: To explore the mechanisms of oxidative stress-induced damage to TM4 Sertoli cells in the mouse using metabolomics techniques based on gas chromatography-mass spectrometry (GC-MS). METHODS: We established the model of oxidative stress-induced damage to mouse TM4 Sertoli cells by treatment with H₂O₂. Then, we detected the survival rate and apoptosis rate of the TM4 cells by MTT and flow cytometry respectively, measured the concentration of ROS in the TM4 cells with the DCFH-DA fluorescent probe, and determined the levels of endogenous metabolites in the TM4 cells by GC-MS after H₂O₂ intervention. RESULTS: After 2 hours of treatment with H₂O₂ at 600 μmol/L, the survival rate of the TM4 cells was reduced to about 50%, and the total apoptosis rates in the low- (100 μmol/L), medium- (300 μmol/L), and high-dose (600 μmol/L) groups were (19.45 ± 0.53), (20.12 ± 0.58), and (37.13 ± 0.35)%, respectively, increased in a dose-dependent manner as compared with (10.28 ± 0.35)% in the blank control (P <0.05). The ROS level was significantly higher in the medium- and high-dose groups than in the control (［1.27 ± 0.10］ vs ［1.00 ± 0.08］%, P <0.05; ［2.07 ± 0.09］ vs ［1.00 ± 0.08］%, P <0.01). Compared with the blank control group, the high-dose H₂O₂ group showed evident changes in the levels of amino acid and carbohydrates in the TM4 cells, more significantly in the levels of valine, norvaline, leucine, glutamic acid, arabinose, fructose, and 5-serotonin cholesterol (VIP >1, P <0.05). CONCLUSIONS Oxidative stress-induced damage and apoptosis of TM4 Sertoli cells are closely associated with the metabolism of amino acid, glucose, and energy in the cells.
Amino Acids ; metabolism ; Animals ; Apoptosis ; Cell Survival ; drug effects ; Dose-Response Relationship, Drug ; Energy Metabolism ; Gas Chromatography-Mass Spectrometry ; Glucose ; metabolism ; Hydrogen Peroxide ; pharmacology ; Male ; Metabolomics ; Mice ; Oxidative Stress ; Reactive Oxygen Species ; metabolism ; Sertoli Cells ; drug effects ; metabolism ; Time Factors