ABSTRACT
Sirtuins are a family of NAD+ -dependent deacetylases that regulate some important biological processes, including lipid metabolism and autophagy, through their deacetylase function. Autophagy is a new discovery in the field of lipid metabolism, which may provide a new idea for the regulation of lipid metabolism. There are many tandem parts in the regulation process of lipid metabolism and autophagy of sirtuins protein family. This paper summarized these tandem parts and proposed the possibility of sirtuins regulating lipid autophagy, as well as the interaction and synergy between sirtuins protein family. Currently, some natural drugs have been reported to affect metabolism by regulating sirtuins, some of which regulate autophagy by targeting sirtuins.
Subject(s)
Lipid Metabolism , Sirtuins , Sirtuins/metabolism , Proteins/metabolism , AutophagyABSTRACT
To analyze psychological and emotional changes in breast cancer patients at different ages before and after surgery based on data. The clinical data of 363 patients undergoing radical mastectomy for breast cancer in our hospital from December 2019 to December 2021 were selected for retrospective analysis. The patients' psychological and emotional changes before and after surgery were evaluated with the mental health symptom self-rating scale, and patients' quality of life was assessed by World Health Organization Quality of Life (WHOQOL)-BREF. On a whole, no significant differences in the patients' scores on somatization, interpersonal sensitivity, dreadness and others before and after surgery were observed (P > 0.05), while their scores on obsessive-compulsive symptom, depression, anxiety, hostility, paranoid ideation and psychopathy as well as the total scores were significantly different (P < 0.05); before and after surgery, patients' psychological scores were not significantly different among the five groups (P > 0.05), but various WHOQOL-BREF scores were significantly different (P < 0.05). Surgical treatment has little impact on the psychological mood of breast cancer patients, obvious difference in quality of life is presented among patients at different ages before and after surgery, and therefore targeted clinical intervention should be given.
ABSTRACT
Metallic Mimosa pudica, a three-dimensional (3D) biomimetic structure made of metallic glass, is formed via laser patterning: Blooming, closing, and reversing of the metallic M. pudica can be controlled by an applied magnetic field or by manual reshaping. An array of laser-crystallized lines is written in a metallic glass ribbon. Changes in density and/or elastic modulus due to laser patterning result in an appropriate size mismatch between the shrunken crystalline regions and the glassy matrix. The residual stress and elastic distortion energy make the composite material to buckle within the elastic limit and to obey the minimum elastic energy criterion. This work not only provides a programming route for constructing buckling structures of metallic glasses but also provides clues for the study of materials with automatic functions desired in robotics, electronic devices, and, especially, medical devices in the field of medicine, such as vessel scaffolds and vascular filters, which require contactless expansion and contraction functions.
ABSTRACT
Previous studies have demonstrated that G protein-coupled receptor kinase interacting-1 protein (GIT1) associates with endothelial nitric oxide synthase (eNOS) to regulate nitric oxide production in sinusoidal endothelial cells (SECs). Here, we hypothesized that GIT1's tightly associated binding partner, ß-PIX (p21-activated kinase-interacting exchange factor ß, ARHGEF7) is specifically important in the regulation of eNOS activity. We examined ß-PIX expression in normal rat liver by immunohistochemistry and explored ß-PIX protein-protein interactions using immunoprecipitation and immunoblotting. The role of ß-PIX in regulating eNOS enzymatic activity was studied in GIT1-deficient SECs. Finally, structural analysis of interaction sites in GIT1 and ß-PIX required to regulate eNOS activity were mapped. ß-PIX was expressed primarily in SECs in normal liver and was either absent or expressed at extremely low levels in other liver cells (stellate cells, Kupffer cells, and hepatocytes). ß-PIX interacted with GIT1 and eNOS to form a trimolecular signaling module in normal SECs and was important in stimulating eNOS activity. Of note, GIT1-ß-PIX interaction led to synergistic enhancement of eNOS activity, and ß-PIX-driven increase in eNOS activity was GIT1 dependent. Disruption of ß-PIX or GIT1 in normal SECs using ß-PIX siRNA or GIT1-deficient SECs led to reduced eNOS activity. Finally, specific GIT1 domains [Spa2 homology domain (SHD) and synaptic localization domain (SLD), aa 331-596] and the ß-PIX COOH terminal (aa 496-555) appeared to be critical in the regulation eNOS activity. The data indicate that ß-PIX regulates eNOS phosphorylation and function in normal SECs and highlight the importance of the GIT1/ß-PIX/eNOS trimolecular complex in normal liver SEC function.NEW & NOTEWORTHY ß-PIX is a multidomain protein known to be a GIT1 binding partner. We report here that in the normal liver, the distribution and cellular localization of ß-PIX are restricted largely to sinusoidal endothelial cells. Furthermore, ß-PIX interacts with eNOS and GIT1 promotes eNOS activity and NO production and therefore exerts a novel posttranslational regulatory function on eNOS activity in sinusoidal endothelial cells. We also have identified specific molecular domains important in GIT1 and ß-PIX's interaction with eNOS, which may represent novel therapeutic targets in the control of sinusoidal blood flow and intrahepatic resistance.
Subject(s)
Cell Cycle Proteins , Endothelial Cells , Nitric Oxide Synthase Type III , Rho Guanine Nucleotide Exchange Factors , Animals , Rats , Cell Cycle Proteins/genetics , Endothelial Cells/metabolism , Nitric Oxide/metabolism , Nitric Oxide Synthase Type III/metabolism , Phosphorylation , Rho Guanine Nucleotide Exchange Factors/genetics , Rho Guanine Nucleotide Exchange Factors/metabolism , Signal TransductionABSTRACT
The G-phase, a new metastable phase with its potential energy sitting right in the middle of the glass and crystal, was recently discovered in some simulations when the molten metallic liquid was quenched down to room temperature. In comparison with ordinary glass, the G-phase has a more ordered short-range structure but a similarly disordered long-range structure. The question is whether the G-phase can be termed a new type of glass. In this work, G-phase Cu is made in a molecular dynamics simulation using rapid quenching or isothermal annealing. Weak oscillations are found in the long-range atomic structure. The pseudo-fictive temperature is significantly lower than the Kauzmann temperature; fivefold twinning structures are distinguished in the G-phase whose constituent atoms are face-center-cubic or hexagonal-cubic-packed. This evidence suggests that G-phase Cu is not a glass. However, the G-phase is also metastable against crystallization. Therefore, G-phase Cu is neither a glass nor a crystal but belongs to a new mesophase.
ABSTRACT
Pediococcus acidilactici is a reliable bacteriocin producer and a promising probiotic species with wide application in the food and health industry. However, the underlying genetic features of this species have not been analyzed. In this study, we performed a comprehensive comparative genomic analysis of 41 P. acidilactici strains from various ecological niches. The bacteriocin production of 41 strains were predicted and three kinds of bacteriocin encoding genes were identified in 11 P. acidilactici strains, namely pediocin PA-1, enterolysin A, and colicin-B. Moreover, whole-genome analysis showed a high genetic diversity within the population, mainly related to a large proportion of variable genomes, mobile elements, and hypothetical genes obtained through horizontal gene transfer. In addition, comparative genomics also facilitated the genetic explanation of the adaptation for host environment, which specify the protection mechanism against the invasion of foreign DNA (i.e. CRISPR/Cas locus), as well as carbohydrate fermentation. The 41 strains of P. acidilactici can metabolize a variety of carbon sources, which enhances the adaptability of this species and survival in different environments. This study evaluated the antibacterial ability, genome evolution, and ecological flexibility of P. acidilactici from the perspective of genetics and provides strong supporting evidence for its industrial development and application.
Subject(s)
Genome, Bacterial , Pediococcus acidilactici/genetics , Anti-Bacterial Agents/biosynthesis , Bacteriocins/biosynthesis , Genomics , Pediococcus acidilactici/classification , Pediococcus acidilactici/metabolismABSTRACT
The tight association between malnutrition and gut microbiota (GM) dysbiosis enables microbiota-targeting intervention to be a promising strategy. Thus, we used a malnourished pig model to investigate the host response and GM alterations under different diet supplementation strategies. Pigs at age of 4 weeks were fed with pure maize diet to induce malnutrition symptoms, and followed by continuous feeding with maize (Maize, n = 8) or re-feeding using either corn-soy-blend (CSB+, n = 10) or millet-soy-blend based (MSB+, n = 10) supplementary food for 3 weeks. Meanwhile, 8 pigs were fed on a standard formulated ration as control (Ref). The effect of nutritional supplementation was assessed by the growth status, blood chemistry, gastrointestinal pathology, mucosal microbiota composition and colon production of short-chain fatty acids. Compared with purely maize-fed pigs, both CSB+ and MSB+ elevated the concentrations of total protein and globulin in blood. These pigs still showed most malnutrition symptoms after the food intervention period. MSB+ had superior influence on the GM development, exhibiting better performance in both structural and functional aspects. MSB+ pigs were colonized by less Proteobacteria but more Bacteroidetes, Firmicutes and Lachnospira spp. Pearson's correlation analysis indicated a strong correlation between the abundance of mucosal e.g., Faecalibacterium and Lachnospira spp. and body weight, crown-rump length and total serum protein. In conclusion, the malnutrition symptoms were accompanied by an aberrant GM, and millet-based nutritional supplementation showed promising potentials to restore the reduced GM diversity implicated in pig malnutrition.
Subject(s)
Animal Feed/analysis , Diet/methods , Dysbiosis/diet therapy , Gastrointestinal Microbiome/physiology , Malnutrition/diet therapy , Millets/chemistry , Animals , Bacteroidetes/genetics , Bacteroidetes/growth & development , Bacteroidetes/isolation & purification , Biodiversity , Blood Proteins/agonists , Blood Proteins/metabolism , Body Weight , Clostridiales/genetics , Clostridiales/growth & development , Clostridiales/isolation & purification , Dysbiosis/microbiology , Dysbiosis/pathology , Faecalibacterium/genetics , Faecalibacterium/growth & development , Faecalibacterium/isolation & purification , Fatty Acids, Volatile/biosynthesis , Female , Firmicutes/genetics , Firmicutes/growth & development , Firmicutes/isolation & purification , Malnutrition/microbiology , Malnutrition/pathology , Proteobacteria/genetics , Proteobacteria/growth & development , Proteobacteria/isolation & purification , RNA, Ribosomal, 16S/genetics , Glycine max/chemistry , Swine , Verrucomicrobia/genetics , Verrucomicrobia/growth & development , Verrucomicrobia/isolation & purification , Zea mays/chemistrySubject(s)
Arrestins , Liver Diseases , Arrestins/metabolism , Cell Nucleus/metabolism , Humans , beta-Arrestin 1 , beta-ArrestinsABSTRACT
To measure intraspecific and interspecific interaction coefficients among tree species is the key to explore the underlying mechanisms for species coexistence and biodiversity maintenance in forests. Through the response surface experimental design, we established a long-term field experiment by planting 27,300 seedlings of four tree species (Erythrophleum fordii, Pinus massoniana, Castanopsis fissa, and Castanopsis carlesii) in 504 plots in different species combinations (six pairwise combinations of four species), abundance proportions (five abundance proportions of two species, i.e. A: B = 1:0, 3:1, 1:1, 1:3, 0:1), and stand densities (25, 36, 64, and 100 seedlings per plot). In this initial report, we aimed to quantify the relative importance of biotic and abiotic factors on seedling survival at the early stage of growth, which is a critical period for seedling establishment. We found that plot-level seedling survival rate was determined by species combination and their abundance proportion rather than stand density. At the individual level, individual survival probability was mainly explained by species identity, initial seedling size, and soil conditions rather than neighborhood competition. Our study highlights that the seedling intrinsic properties may be the key factors in determining seedling survival rate, while neighborhood effects were not yet prominent at the seedling life stage.
ABSTRACT
Endothelial cell nitric oxide (NO) synthase (eNOS), the enzyme responsible for synthesis of NO in endothelial cells, is regulated by complex posttranslational mechanisms. Sinusoidal portal hypertension, a disorder characterized by liver sinusoidal endothelial cell (SEC) injury with resultant reduced eNOS activity and NO production within the liver, has been associated with defects in eNOS protein-protein interactions and posttranslational modifications. We and others have previously identified novel eNOS interactors, including G protein-coupled receptor (GPCR) kinase interactor 1 (GIT1), which we found to play an unexpected stimulatory role in GPCR-mediated eNOS signaling. Here we report that ß-arrestin 2 (ß-Arr2), a canonical GPCR signaling partner, localizes in SECs with eNOS in a GIT1/eNOS/NO signaling module. Most importantly, we show that ß-Arr2 stimulates eNOS activity, and that ß-Arr2 expression is reduced and formation of the GIT1/eNOS/NO signaling module is interrupted during liver injury. In ß-Arr2-deficient mice, bile duct ligation injury (BDL) led to significantly reduced eNOS activity and to a dramatic increase in portal hypertension compared to BDL in wild-type mice. Overexpression of ß-Arr2 in injured or ß-Arr2-deficient SECs rescued eNOS function by increasing eNOS complex formation and NO production. We also found that ß-Arr2-mediated GIT1/eNOS complex formation is dependent on Erk1/2 and Src, two kinases known to interact with and be activated by ß-Arr2 in response to GCPR activation. Our data emphasize that ß-Arr2 is an integral component of the GIT1/eNOS/NO signaling pathway and have implications for the pathogenesis of sinusoidal portal hypertension.
Subject(s)
Nitric Oxide Synthase Type III/metabolism , Receptors, G-Protein-Coupled/metabolism , Signal Transduction/physiology , beta-Arrestin 2/metabolism , Animals , Cells, Cultured , Hepatic Stellate Cells/metabolism , Hypertension, Portal/metabolism , Liver/cytology , Liver/metabolism , Liver Diseases/metabolism , Male , Mice , Mice, Knockout , Nitric Oxide/metabolism , Nitric Oxide Synthase Type III/genetics , Rats , Rats, Sprague-Dawley , Receptors, G-Protein-Coupled/genetics , Signal Transduction/genetics , beta-Arrestin 2/geneticsABSTRACT
Lactobacillus plantarum was not only one of the most popular probiotics, but also one of the most versatile lactic acid bacteria. L. plantarum LLY-606 and L. plantarum pc-26 are strains isolated from human gut that are intended to be explored as probiotics. In this study, the genome sequences of LLY-606 and pc-26 were sequenced, and multiple genes related to probiotic properties were analyzed. First, the pathogenicity of these strains was evaluated, and antibiotic resistance genes were surveyed at the whole genome level to determine their primary safety. And then, genes for stress response, plantaricin (pln) biosynthesis, extracellular polysaccharide (EPS) biosynthesis, and bile salt hydrolase (BSH) were analyzed to evaluate their industrial utilization, adhesive capacity, and survival ability in gut, which were properties fundamental for probiotic strains. The physiological features assured by these genes were assayed in vitro. The strains were then evaluated in vivo for their ability to lower cholesterol, and they were both found to be effective in improving hypercholesterolemia in golden hamsters. In this study, a genetic pre-evaluation was conducted through genome analysis combined with in vitro physiological assay, and the probiotic properties of these strains were verified in vivo.
ABSTRACT
Hypercholesterolemia is a major risk factor for cardiovascular disease (CVD). Probiotics are one of the most popular dietary supplements for hypercholesterolemia, but there are questions as to whether there are differences between probiotics and cholesterol-lowering drugs like atorvastatin (ATO) both in effectiveness and in the underlying mechanisms. In this study, the hypocholesterolemia effects of 4 probiotic strains were investigated and compared with ATO, focusing on their impacts on the gut microbiota. A hypercholesterolemia model was established via high-fat diet (HFD) in golden hamsters after which ATO and the 4 probiotics were orally administered individually for 8 weeks. All probiotics were effective, but less than ATO, on body weight, serum parameters (TG, TC, LDL, INS, HbA1c) and expression of inflammatory factors (INF-α, IL-1ß, CRP), with strain JQII-5 being most significant. Besides, these effects were associated with restoration of microbiota dysbiosis induced by HFD. It was worth noting that ATO and probiotics induced different shifts of the gut microbiota in both structure and key phylotypes. Most interestingly, Allobaculum, a HFD-suppressed genus, reported to be involved in alleviating oxidative stress, was enriched by all tested probiotic strains, but not by ATO. Furthermore, Prevotella, also a HFD-suppressed genus, was uniquely reversed by JQII-5. Importantly, most of the alerted genera and reversed genera were found to be correlated with the inflammatory state and serum lipid level. Compared with ATO, the probiotic strains were less effective on body weight, hypercholesterolemia, and inflammation. However, probiotics exert additional favorable effects on the gut microbiota, making them excellent potential complements to cholesterol-lowering drugs like ATO.
Subject(s)
Atorvastatin/therapeutic use , Diet, High-Fat/adverse effects , Gastrointestinal Microbiome/physiology , Hypercholesterolemia/therapy , Lactobacillus plantarum/physiology , Pediococcus/physiology , Animals , Anticholesteremic Agents/therapeutic use , Bacteria/classification , Bacteria/isolation & purification , Cricetinae , Cytokines/analysis , Dysbiosis/etiology , Dysbiosis/therapy , Feces/microbiology , Glucose/metabolism , Hypercholesterolemia/drug therapy , Male , Mesocricetus , Pediococcus acidilactici/physiology , Pediococcus pentosaceus/physiology , Probiotics/therapeutic use , Weight Gain/drug effectsABSTRACT
Liver injury leads to a vasculopathy in which post-translational modifications of endothelial nitric oxide synthase (eNOS) lead to impaired nitric oxide synthesis. We hypothesized that caveolin 1 (CAV1), a well-known eNOS interactor, regulates eNOS activity in sinusoidal endothelial cells (SECs) via its interaction with G-protein-coupled receptor kinase-2 (GRK2) that also post-translationally modifies eNOS. Liver injury with portal hypertension was established using bile duct ligation in rats. CAV1 function was modified using a CAV1 scaffolding domain construct and cDNAs encoding wild-type CAV1, and CAV1 phosphorylation was increased in injured SECs, resulting in increased GRK2-CAV1 interaction and decreased eNOS activity. In injured SECs, endothelin-1 blocked CAV1 phosphorylation induced by CAV1 scaffolding domain, indicating that CAV1 interaction with GRK2 is inversely regulated by endothelin-1 and CAV1 scaffolding domain after liver injury. In addition, after transduction with DNA encoding wild-type CAV1 into SECs isolated from Cav1-deficient mice, GRK2 association with CAV1 was evident, whereas transduction with a dominant negative CAV1 mutated at tyrosine 14 reduced the interaction. Finally, isoproterenol-induced GRK2 phosphorylation enhanced CAV1-GRK2 interaction and reduced eNOS activity. Our data suggest a novel mechanism and model in which CAV1 phosphorylation facilitates CAV1 scaffolding and GRK2-CAV1 interaction, thus clustering eNOS within a complex that inhibits eNOS activity. This process takes place in injured, but not in normal, SECs.
Subject(s)
Caveolin 1/metabolism , Endothelial Cells/metabolism , G-Protein-Coupled Receptor Kinases/metabolism , Liver/pathology , Nitric Oxide Synthase Type III/metabolism , Animals , Caveolin 1/chemistry , Endothelial Cells/drug effects , Endothelial Cells/pathology , Endothelin-1/metabolism , Humans , Isoproterenol/pharmacology , Liver/injuries , Male , Mice, Knockout , Models, Biological , Phosphorylation/drug effects , Phosphotyrosine/metabolism , Protein Binding/drug effects , Protein Domains , Rats, Sprague-Dawley , Receptor, Endothelin B/metabolismABSTRACT
The acid response of Bifidobacterium longum subsp. longum BBMN68 has been studied in our previous study. The fab gene, which is supposed to be involved in membrane fatty acid biosynthesis, was demonstrated to be induced in acid response. In order to investigate the relationship between acid response and cell membrane fatty acid composition, the acid adaptation of BBMN68 was assessed and the membrane fatty acid composition at different adaptation conditions was identified. Indeed, the fatty acid composition was influenced by acid adaptation. Our results showed that the effective acid adaptations were accompanied with decrease in the unsaturated to saturated fatty acids ratio (UFA/SFA) and increase in cyclopropane fatty acid (CFA) content, which corresponded to previous studies. Moreover, both effective and non-effective acid adaptation conditions resulted in decrease in the C18:1 cis-9/C18:1 trans-9 ratio, indicating that the C18:1 cis-9/C18:1 trans-9 ratio is associated with acid tolerance response but not with acid adaptation response. Taken together, this study indicated that the UFA/SFA and CFA content of BBMN68 were involved in acid adaptation and the C18:1 cis-9/C18:1 trans-9 ratio was involved in acid tolerance response.
Subject(s)
Acids/metabolism , Bifidobacterium longum/metabolism , Cell Membrane/metabolism , Fatty Acids/metabolism , Adaptation, Biological , Bifidobacterium longum/growth & development , Cell Membrane/chemistry , Culture Media , Fatty Acids/chemistry , Hydrogen-Ion ConcentrationABSTRACT
Streptococcus thermophilus MN-BM-A01 (ST MN-BM-A01) (CGMCC No. 11383) was a strain isolated from Yogurt Block in Gansu, China. The yogurt fermented with this strain has good flavor, acidity, and viscosity. Moreover, ST MN-BM-A01 could produce a high level of EPS which can confer the yogurt with improved rheological properties. We reported the complete genome sequence of ST MN-BM-A01 that contains 1,876,516bp encoding 1704 coding sequences (CDSs), 67 tRNA genes and 6 rRNA operons. The genomic sequence indicated that this strain included a 35.3-kb gene cluster involved in EPS biosynthesis.
Subject(s)
Genome, Bacterial , Sequence Analysis, DNA/methods , Streptococcus thermophilus/genetics , Base Composition , Genes, rRNA , Genome Size , Multigene Family , Polysaccharides, Bacterial/biosynthesis , RNA, Transfer/geneticsABSTRACT
Sinusoidal endothelial cells (SEC) and hepatic stellate cells (HSC) are closely associated specialized vascular cells residing in the hepatic sinusoid. These cells have been shown to play important roles in many different pathophysiologic processes, in particular in liver fibrosis/cirrhosis and portal hypertension. Caveolin-1 functions as a scaffolding protein, and has a variety of functions including in many disease states, such as liver cirrhosis. Although previous studies have shown that in the injured rat liver, caveolin-1 is upregulated, the precise cells in which remains unclear. Therefore, the purpose of this study was to clarify the cell type (or types) in which caveolin-1 is expressed in normal and injured rat liver. We have utilized both detailed immunohistochemical labeling with cell specific markers as well as cell isolation techniques (isolating sinusoidal endothelial cells, HSCs, and hepatocytes) in normal and injured (bile duct ligation) rat liver. We show here that in the normal liver caveolin-1 is expressed predominantly in HSCs and SECs but after liver injury there is upregulation of caveolin-1 in HSCs, but not in SECs. These data have functional implications for the cells in which caveolin-1 is regulated.
Subject(s)
Caveolin 1/biosynthesis , Endothelial Cells/metabolism , Hepatic Stellate Cells/metabolism , Liver Cirrhosis/metabolism , Liver/metabolism , Animals , Capillaries/metabolism , Capillaries/pathology , Caveolin 1/genetics , Endothelial Cells/pathology , Gene Expression Regulation , Hepatic Stellate Cells/pathology , Hepatocytes/metabolism , Hepatocytes/pathology , Humans , Liver/blood supply , Liver/injuries , Liver/pathology , Liver Cirrhosis/pathology , Nitric Oxide/biosynthesis , Nitric Oxide/metabolism , RatsABSTRACT
TMEM16A is a newly identified Ca(2+)-activated Cl(-) channel in biliary epithelial cells (BECs) that is important in biliary secretion. While extracellular ATP stimulates TMEM16A via binding P2 receptors and increasing intracellular Ca(2+) concentration ([Ca(2+)]i), the regulatory pathways have not been elucidated. Protein kinase C (PKC) contributes to ATP-mediated secretion in BECs, although its potential role in TMEM16A regulation is unknown. To determine whether PKCα regulates the TMEM16A-dependent membrane Cl(-) transport in BECs, studies were performed in human biliary Mz-cha-1 cells. Addition of extracellular ATP induced a rapid translocation of PKCα from the cytosol to the plasma membrane and activation of whole cell Ca(2+)-activated Cl(-) currents. Currents demonstrated outward rectification and reversal at 0 mV (properties consistent with TMEM16A) and were inhibited by either molecular (siRNA) or pharmacologic (PMA or Gö6976) inhibition of PKCα. Intracellular dialysis with recombinant PKCα activated Cl(-) currents with biophysical properties identical to TMEM16A in control cells but not in cells after transfection with TMEM16A siRNA. In conclusion, our studies demonstrate that PKCα is coupled to ATP-stimulated TMEM16A activation in BECs. Targeting this ATP-Ca(2+)-PKCα signaling pathway may represent a therapeutic strategy to increase biliary secretion and promote bile formation.
Subject(s)
Bile Ducts/enzymology , Chloride Channels/metabolism , Chlorides/metabolism , Epithelial Cells/enzymology , Neoplasm Proteins/metabolism , Protein Kinase C-alpha/metabolism , Adenosine Triphosphate/pharmacology , Anoctamin-1 , Bile Ducts/cytology , Bile Ducts/drug effects , Bile Ducts/metabolism , Calcium/metabolism , Cell Line, Tumor , Chloride Channels/genetics , Epithelial Cells/drug effects , Epithelial Cells/metabolism , Humans , Membrane Potentials , Neoplasm Proteins/genetics , Protein Kinase C-alpha/antagonists & inhibitors , Protein Kinase C-alpha/genetics , Protein Kinase Inhibitors/pharmacology , Protein Transport , RNA Interference , Signal Transduction , TransfectionABSTRACT
Acid stress can affect the viability of probiotics, especially Bifidobacterium. This study aimed to improve the acid tolerance of Bifidobacterium longum BBMN68 using adaptive evolution. The stress response, and genomic differences of the parental strain and the variant strain were compared by acid stress. The highest acid-resistant mutant strain (BBMN68m) was isolated from more than 100 asexual lines, which were adaptive to the acid stress for 10(th), 20(th), 30(th), 40(th), and 50(th) repeats, respectively. The variant strain showed a significant increase in acid tolerance under conditions of pH 2.5 for 2 h (from 7.92 to 4.44 log CFU/ml) compared with the wildtype strain (WT, from 7.87 to 0 log CFU/ml). The surface of the variant strain was also smoother. Comparative whole-genome analysis showed that the galactosyl transferase D gene (cpsD, bbmn68_1012), a key gene involved in exopolysaccharide (EPS) synthesis, was altered by two nucleotides in the mutant, causing alteration in amino acids, pI (from 8.94 to 9.19), and predicted protein structure. Meanwhile, cpsD expression and EPS production were also reduced in the variant strain (p < 0.05) compared with WT, and the exogenous WT-EPS in the variant strain reduced its acid-resistant ability. These results suggested EPS was related to acid responses of BBMN68.
Subject(s)
Acids/metabolism , Bifidobacterium longum/metabolism , Biological Evolution , Bacterial Proteins/genetics , Bacterial Proteins/metabolism , Bifidobacterium longum/enzymology , Bifidobacterium longum/genetics , Gene Expression Regulation, Bacterial , Hydrogen-Ion Concentration , Point MutationABSTRACT
Lactobaillus paracasei L9 (CGMCC No. 9800) is a new strain with probiotic properties originating from healthy human intestine. Previous studies evidenced that the strain regulates immune modulation and contributes to the production of high amounts of lactic acid. The genome of L. paracasei L9 contains a circular 3076,437-bp chromosome, encoding 3044 CDSs, 15 rRNA genes and 59 tRNA genes.
Subject(s)
Genome, Bacterial , Lactic Acid/biosynthesis , Lactobacillus/genetics , Probiotics/metabolism , Base SequenceABSTRACT
Lactobacillus salivarius Ren (LsR) (CGMCC No. 3606) is a probiotic strain that was isolated from the feces of a healthy centenarian living in Bama, Guangxi, China. Previous studies have shown that this strain decreases 4-nitroquinoline 1-oxide (4-NQO)-induced genotoxicity in vitro. It also suppresses 4-NQO-induced oral carcinogenesis and 1,2-dimethylhydrazine (DMH)-induced colorectal carcinogenesis, and therefore may be used as an adjuvant therapeutic agent for cancer. Here, we report the complete genome sequence of LsR that consists of a circular chromosome of 1751,565 bp and two plasmids (pR1, 176,951 bp; pR2, 49,848 bp).