scholarly journals Prophylactic inhibition of colonization by Streptococcus pneumoniae with the secondary bile acid metabolite deoxycholic acid

2021 ◽  
Author(s):  
Jorge E. Vidal ◽  
Meagan N. Wier ◽  
Uriel Angulo-Zamudio ◽  
Erin McDevitt ◽  
Ana G. Jop Vidal ◽  
...  
Keyword(s):  
Bile Acid ◽  
Streptococcus Pneumoniae ◽  
Deoxycholic Acid ◽  
Therapeutic Potential ◽  
Post Inoculation ◽  
Acid Metabolite ◽  
Nasopharyngeal Colonization ◽  
Secondary Bile Acid ◽  
Human Bile

Streptococcus pneumoniae (Spn) colonizes the nasopharynx of children and the elderly but also kills millions worldwide yearly. The secondary bile acid metabolite, deoxycholic acid (DoC), affects the viability of human pathogens but also plays multiple roles in host physiology. We assessed in vitro the antimicrobial activity of DoC and investigated its potential to eradicate Spn colonization using a model of human nasopharyngeal colonization and an in vivo mouse model of colonization. At a physiological concentration DoC (0.5 mg/ml; 1.27 mM) killed all tested Spn strains (N=48) two hours post-inoculation. The model of nasopharyngeal colonization showed that DoC eradicated colonization by Spn strains as soon as 10 min post-exposure. The mechanism of action did not involve activation of autolysis since the autolysis-defective double mutants Δ lytA Δ lytC and ΔspxBΔlctO were as susceptible to DoC as was the wild-type (WT). Oral streptococcal species (N=20), however, were not susceptible to DoC (0.5 mg/ml). Unlike trimethoprim, whose spontaneous resistance frequency (srF) for TIGR4 or EF3030 was ≥1x10 −9 , no spontaneous resistance was observed with DoC (srF≥1x10- 12 ). Finally, the efficacy of DoC to eradicate Spn colonization was assessed in vivo using a topical route via intranasal (i.n.) administration and as a prophylactic treatment. Mice challenged with Spn EF3030 carried a median of 4.05x10 5 cfu/ml four days post-inoculation compared to 6.67x10 4 cfu/ml for mice treated with DoC. Mice in the prophylactic group had a ∼99% reduction of the pneumococcal density (median, 2.61 x10 3 cfu/ml). Thus, DoC, an endogenous human bile salt, has therapeutic potential against Spn.

scholarly journals Prophylactic inhibition of colonization by Streptococcus pneumoniae with the secondary bile acid metabolite deoxycholic acid

2021 ◽  
Author(s):  
Jorge E. Vidal ◽  
Meagan N. Wier ◽  
Uriel Angulo-Zamudio ◽  
Erin McDevitt ◽  
Ana G Vidal ◽  
...  
Keyword(s):  
Bile Acid ◽  
Streptococcus Pneumoniae ◽  
Deoxycholic Acid ◽  
Ex Vivo ◽  
Post Inoculation ◽  
Acid Metabolite ◽  
Nasopharyngeal Colonization ◽  
Secondary Bile Acid ◽  
Human Bile

Streptococcus pneumoniae (Spn) colonizes the nasopharynx of children and the elderly but also kills millions worldwide yearly. The secondary bile acid metabolite, deoxycholic acid (DoC), affects the viability of human pathogens but also plays multiple roles in host physiology. We assessed in vitro the antimicrobial activity of DoC and investigated its potential to eradicate Spn colonization using an ex vivo model of human nasopharyngeal colonization and an in vivo mouse model of colonization. At a physiological concentration DoC (0.5 mg/ml; 1.27 mM) killed all tested Spn strains (N=48) two h post-inoculation. The ex-vivo model of nasopharyngeal colonization showed that DoC eradicated colonization by Spn strains as soon as 10 min post-exposure. The mechanism of action did not involve activation of autolysis since the autolysis-defective double mutants ΔlytAΔlytC and ΔspxBΔlctO were as susceptible to DoC as was the wild-type (WT). Oral streptococcal species (N=20), however, were not susceptible to DoC (0.5 mg/ml). Unlike trimethoprim, whose spontaneous resistance frequency (srF) for TIGR4 or EF3030 was ≥1x10-9, no spontaneous resistance was observed with DoC (srF≥1x10-12). Finally, the efficacy of DoC to eradicate Spn colonization was assessed in vivo using a topical route via intranasal (i.n.) administration and as a prophylactic treatment. Mice challenged with Spn EF3030 carried a median of 4.05x105 cfu/ml four days post-inoculation compared to 6.67x104 cfu/ml for mice treated with DoC. Mice in the prophylactic group had a ~99% reduction of the pneumococcal density (median, 2.61 x103 cfu/ml). Thus, DoC, an endogenous human bile salt, has therapeutic potential against Spn.

In Vitro Metabolism of E2, G2: Novel Bile Acid-Coupling Camptothecin Analogues, in Rat Liver Microsomes

2021 ◽  
Vol 16 ◽  
Author(s):  
Xiangli Zhang ◽  
Qin Shen ◽  
Yi Wang ◽  
Leilei Zhou ◽  
Qi Weng ◽  
...  
Keyword(s):  
Bile Acid ◽  
Phase I ◽  
Rat Liver ◽  
Deoxycholic Acid ◽  
Liver Microsomes ◽  
Intrinsic Clearance ◽  
Rat Liver Microsomes ◽  
Camptothecin Analogues

Background: E2 (Camptothecin - 20 (S) - O- glycine - deoxycholic acid), and G2 (Camptothecin - 20 (S) - O - acetate - deoxycholic acid) are two novel bile acid-derived camptothecin analogues by introducing deoxycholic acid in 20-position of CPT(camptothecin) with greater anticancer activity and lower systematic toxicity in vivo. Objective: We aimed to investigate the metabolism of E2 and G2 by Rat Liver Microsomes (RLM). Methods: Phase Ⅰ and Phase Ⅱ metabolism of E2 and G2 in rat liver microsomes were performed respectively, and the mixed incubation of phase I and phase Ⅱ metabolism of E2 and G2 was also processed. Metabolites were identified by liquid chromatographic/mass spectrometry. Results: The results showed that phase I metabolism was the major biotransformation route for both E2 and G2. The isoenzyme involved in their metabolism had some difference. The intrinsic clearance of G2 was 174.7mL/min. mg protein, more than three times of that of E2 (51.3 mL/min . mg protein), indicating a greater metabolism stability of E2. 10 metabolites of E2 and 14 metabolites of G2 were detected, including phase I metabolites (mainly via hydroxylations and hydrolysis) and their further glucuronidation products. Conclusion: These findings suggested that E2 and G2 have similar biotransformation pathways except some difference in the hydrolysis ability of the ester bond and amino bond from the parent compounds, which may result in the diversity of their metabolism stability and responsible CYPs(Cytochrome P450 proteins).

scholarly journals An optimized probucol microencapsulated formulation integrating a secondary bile acid (deoxycholic acid) as a permeation enhancer

2014 ◽  
pp. 1673 ◽  
Author(s):  
Hani Al-Salami ◽  
Armin Mooranian ◽  
Rebecca Negrulj ◽  
Nigel Chen-Tan ◽  
Gerald Watts ◽  
...  
Keyword(s):  
Bile Acid ◽  
Deoxycholic Acid ◽  
Permeation Enhancer ◽  
Secondary Bile Acid

scholarly journals Ursodeoxycholic acid and lithocholic acid exert anti-inflammatory actions in the colon

2017 ◽  
Vol 312 (6) ◽  
pp. G550-G558 ◽  
Author(s):  
Joseph B. J. Ward ◽  
Natalia K. Lajczak ◽  
Orlaith B. Kelly ◽  
Aoife M. O’Dwyer ◽  
Ashwini K. Giddam ◽  
...  
Keyword(s):  
Bile Acid ◽  
Ursodeoxycholic Acid ◽  
Inflammatory Responses ◽  
Lithocholic Acid ◽  
Primary Metabolite ◽  
Secondary Bile Acid ◽  
Colonic Inflammation ◽  
Anti Inflammatory

Inflammatory bowel diseases (IBD) comprise a group of common and debilitating chronic intestinal disorders for which currently available therapies are often unsatisfactory. The naturally occurring secondary bile acid, ursodeoxycholic acid (UDCA), has well-established anti-inflammatory and cytoprotective actions and may therefore be effective in treating IBD. We aimed to investigate regulation of colonic inflammatory responses by UDCA and to determine the potential impact of bacterial metabolism on its therapeutic actions. The anti-inflammatory efficacy of UDCA, a nonmetabolizable analog, 6α-methyl-UDCA (6-MUDCA), and its primary colonic metabolite lithocholic acid (LCA) was assessed in the murine dextran sodium sulfate (DSS) model of mucosal injury. The effects of bile acids on cytokine (TNF-α, IL-6, Il-1β, and IFN-γ) release from cultured colonic epithelial cells and mouse colonic tissue in vivo were investigated. Luminal bile acids were measured by gas chromatography-mass spectrometry. UDCA attenuated release of proinflammatory cytokines from colonic epithelial cells in vitro and was protective against the development of colonic inflammation in vivo. In contrast, although 6-MUDCA mimicked the effects of UDCA on epithelial cytokine release in vitro, it was ineffective in preventing inflammation in the DSS model. In UDCA-treated mice, LCA became the most common colonic bile acid. Finally, LCA treatment more potently inhibited epithelial cytokine release and protected against DSS-induced mucosal inflammation than did UDCA. These studies identify a new role for the primary metabolite of UDCA, LCA, in preventing colonic inflammation and suggest that microbial metabolism of UDCA is necessary for the full expression of its protective actions. NEW & NOTEWORTHY On the basis of its cytoprotective and anti-inflammatory actions, the secondary bile acid ursodeoxycholic acid (UDCA) has well-established uses in both traditional and Western medicine. We identify a new role for the primary metabolite of UDCA, lithocholic acid, as a potent inhibitor of intestinal inflammatory responses, and we present data to suggest that microbial metabolism of UDCA is necessary for the full expression of its protective effects against colonic inflammation.

scholarly journals Microbial metabolite deoxycholic acid controlsClostridium perfringens-induced chicken necrotic enteritis through attenuating cyclooxygenase signaling

2018 ◽  
Author(s):  
Hong Wang ◽  
Juan D. Latorre ◽  
Mohit Bansal ◽  
Mussie Abraha ◽  
Bilal Al-Rubaye ◽  
...  
Keyword(s):  
Bile Acid ◽  
Inflammatory Response ◽  
Inflammatory Mediators ◽  
Cell Apoptosis ◽  
Deoxycholic Acid ◽  
Intestinal Inflammation ◽  
Metabolic Product ◽  
Intestinal Cell ◽  
Necrotic Enteritis ◽  
Secondary Bile Acid

AbstractClostridium perfringens-induced necrotic enteritis (NE) has reemerged as a prevalent chicken disease worldwide due to reduced usage of prophylactic antibiotics. The lack of antimicrobial alternative strategies to control NE is mainly due to limited insight into the disease pathogenesis. The aim of this study is to investigate the role of microbiota metabolic product secondary bile acid deoxycholic acid (DCA) on preventing NE.C. perfringensgrowth was inhibited by 82.8% in 50 μM DCA Tryptic Soy Broth. SequentialEimeria maximaandC. perfringenschallenges induced acute NE showed as severe intestinal inflammation and body weight (BW) loss in broiler chickens, while 1.5 g/kg DCA diet dramatically reduced the disease. At the cellular level, DCA alleviated NE-associated ileal epithelial death and reduced lamina propria cell apoptosis. Interestingly, DCA reducedC. perfringensinvasion into ileum without altering the bacterial ileal luminal colonization. Molecular analysis showed that DCA reduced inflammatory mediators ofInfγ,Litaf, andMmp9mRNA accumulation in ileal tissue. Mechanism studies revealed thatC. perfringensinduced elevated expression of inflammatory mediators ofInfγ,Litaf,Mmp9,andPtgs2(Cyclooxygenase- 2 (COX-2) gene) in chicken splenocytes. Blocking COX signaling by pharmacological inhibitor aspirin attenuated INFγ-induced inflammatory response in the splenocytes. Consistent with thein vitroassay, chickens fed 0.12 g/kg aspirin diet protected the birds against NE-induced ileal inflammation, intestinal cell apoptosis, and BW loss. In conclusion, microbial metabolic product DCA prevents NE-induced ileal inflammation and BW loss through attenuating inflammatory response. These novel findings offer new strategies againstC. perfringens-induced diseases.Significance StatementWidespread antimicrobial resistance has become a serious challenge to both agricultural and healthcare industries. Withdrawing antimicrobials without effective alternatives exacerbates chicken productivity loss at billions of dollars every year, caused by intestinal diseases, such as coccidiosis-andC. perfringens-induced necrotic enteritis. This study revealed that microbial metabolic product secondary bile acid DCA preventsC. perfringens-induced intestinal disease in chickens through modulating inflammatory COX signaling pathways. Therefore, microbiome and its downstream targets of host inflammatory responses could be used to control NE. These findings have opened new avenues for developing novel antimicrobial free alternatives to prevent or treatC. perfringens-induced diseases.

scholarly journals Development of a Covalent Inhibitor of Gut Bacterial Bile Salt Hydrolases

2019 ◽  
Author(s):  
Arijit A. Adhikari ◽  
Tom C. Seegar ◽  
Scott B. Ficarro ◽  
Megan D. McCurry ◽  
Deepti Ramachandran ◽  
...  
Keyword(s):  
Bile Acid ◽  
Bile Salt ◽  
Bile Acids ◽  
Unmet Need ◽  
Cysteine Residue ◽  
Gut Bacteria ◽  
Bile Salt Hydrolase ◽  
Secondary Bile Acid ◽  
Bsh Activity

AbstractBile salt hydrolase (BSH) enzymes are widely expressed by human gut bacteria and catalyze the gateway reaction leading to secondary bile acid formation. Bile acids regulate key metabolic and immune processes by binding to host receptors. There is an unmet need for a potent tool to inhibit BSHs across all gut bacteria in order to study the effects of bile acids on host physiology. Here, we report the development of a covalent pan-inhibitor of gut bacterial BSH. From a rationally designed candidate library, we identified a lead compound bearing an alpha-fluoromethyl ketone warhead that modifies BSH at the catalytic cysteine residue. Strikingly, this inhibitor abolished BSH activity in conventional mouse feces. Mice gavaged with a single dose of this compound displayed decreased BSH activity and decreased deconjugated bile acid levels in feces. Our studies demonstrate the potential of a covalent BSH inhibitor to modulate bile acid composition in vivo.

scholarly journals Streptococcus pneumoniae detects and responds to foreign bacterial peptide fragments in its environment

Open Biology ◽  
2014 ◽  
Vol 4 (4) ◽  
pp. 130224 ◽  
Author(s):  
Lucy J. Hathaway ◽  
Patrick Bättig ◽  
Sandra Reber ◽  
Jeannine U. Rotzetter ◽  
Suzanne Aebi ◽  
...  
Keyword(s):  
Streptococcus Pneumoniae ◽  
Bacterial Meningitis ◽  
Bacterial Species ◽  
Ribosomal Subunit ◽  
Peptide Fragments ◽  
Nasopharyngeal Colonization ◽  
Healthy Human ◽  
Interspecies Communication ◽  
Ribosomal Subunit Protein

Streptococcus pneumoniae is an important cause of bacterial meningitis and pneumonia but usually colonizes the human nasopharynx harmlessly. As this niche is simultaneously populated by other bacterial species, we looked for a role and pathway of communication between pneumococci and other species. This paper shows that two proteins of non-encapsulated S. pneumoniae , AliB-like ORF 1 and ORF 2, bind specifically to peptides matching other species resulting in changes in the pneumococci. AliB-like ORF 1 binds specifically peptide SETTFGRDFN, matching 50S ribosomal subunit protein L4 of Enterobacteriaceae, and facilitates upregulation of competence for genetic transformation. AliB-like ORF 2 binds specifically peptides containing sequence FPPQS, matching proteins of Prevotella species common in healthy human nasopharyngeal microbiota. We found that AliB-like ORF 2 mediates the early phase of nasopharyngeal colonization in vivo . The ability of S. pneumoniae to bind and respond to peptides of other bacterial species occupying the same host niche may play a key role in adaptation to its environment and in interspecies communication. These findings reveal a completely new concept of pneumococcal interspecies communication which may have implications for communication between other bacterial species and for future interventional therapeutics.

scholarly journals Isolation of Streptococcus pneumoniae Biofilm Mutants and Their Characterization during Nasopharyngeal Colonization

2008 ◽  
Vol 76 (11) ◽  
pp. 5049-5061 ◽  
Author(s):  
Ernesto J. Muñoz-Elías ◽  
Joan Marcano ◽  
Andrew Camilli
Keyword(s):  
Cell Wall ◽  
Streptococcus Pneumoniae ◽  
Biofilm Formation ◽  
Bacterial Infections ◽  
Nasopharyngeal Colonization ◽  
Genes Encoding ◽  
Transposon Mutants ◽  
Bona Fide

ABSTRACT Asymptomatic colonization of the nasopharynx by Streptococcus pneumoniae precedes pneumococcal disease, yet pneumococcal colonization factors remain poorly understood. Many bacterial infections involve biofilms which protect bacteria from host defenses and antibiotics. To gain insight into the genetics of biofilm formation by S. pneumoniae, we conducted an in vitro screen for biofilm-altered mutants with the serotype 4 clinical isolate TIGR4. In a first screen of 6,000 mariner transposon mutants, we repeatedly isolated biofilm-overproducing acapsular mutants, suggesting that the capsule was antagonistic to biofilm formation. Therefore, we screened 6,500 additional transposon mutants in an S. pneumoniae acapsular background. Following this approach, we isolated 69 insertions in 49 different genes. The collection of mutants includes genes encoding bona fide and putative choline binding proteins, adhesins, synthases of membrane and cell wall components, extracellular and cell wall proteases, efflux pumps, ABC and PTS transporters, and transcriptional regulators, as well as several conserved and novel hypothetical proteins. Interestingly, while four insertions mapped to rrgA, encoding a subunit of a recently described surface pilus, rrgB and rrgC (encoding the other two pilus subunits) mutants had no biofilm defects, implicating the RrgA adhesin but not the pilus structure per se in biofilm formation. To correlate our findings to the process of colonization, we transferred a set of 29 mutations into the wild-type encapsulated strain and then tested the fitness of the mutants in vivo. Strikingly, we found that 23 of these mutants were impaired for nasopharyngeal colonization, thus establishing a link between biofilm formation and colonization.

scholarly journals Inhibition of NF-κB by deoxycholic acid induces miR-21/PDCD4-dependent hepatocellular apoptosis

2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Pedro M. Rodrigues ◽  
Marta B. Afonso ◽  
André L. Simão ◽  
Pedro M. Borralho ◽  
Cecília M. P. Rodrigues ◽  
...  
Keyword(s):  
Cell Death ◽  
Bile Acid ◽  
Deoxycholic Acid ◽  
Rat Hepatocytes ◽  
Dependent Manner ◽  
Apoptotic Pathway ◽  
Alcoholic Fatty Liver ◽  
Programmed Cell Death 4 ◽  
Hepatocellular Apoptosis

Abstract MicroRNAs (miRNAs/miRs) are key regulators of liver metabolism, while toxic bile acids participate in the development of several liver diseases. We previously demonstrated that deoxycholic acid (DCA), a cytotoxic bile acid implicated in the pathogenesis of non-alcoholic fatty liver disease, inhibits miR-21 expression in hepatocytes. Here, we investigated the mechanisms by which DCA modulates miR-21 and whether miR-21 contributes for DCA-induced cytotoxicity. DCA inhibited miR-21 expression in primary rat hepatocytes in a dose-dependent manner and increased miR-21 pro-apoptotic target programmed cell death 4 (PDCD4) and apoptosis. Both miR-21 overexpression and PDCD4 silencing hampered DCA-induced cell death. Further, DCA decreased NF-κB activity, shown to represent an upstream mechanism leading to modulation of the miR-21/PDCD4 pathway. In fact, NF-κB overexpression or constitutive activation halted miR-21-dependent apoptosis by DCA while opposite results were observed upon NF-κB inhibition. In turn, DCA-induced oxidative stress resulted in caspase-2 activation and NF-κB/miR-21 inhibition, in a PIDD-dependent manner. Finally, modulation of the NF-κB/miR-21/PDCD4 pro-apoptotic pathway by DCA was also shown to occur in the rat liver in vivo. These signalling circuits may constitute appealing targets for bile acid-associated liver pathologies.

Sign in / Sign up

Export Citation Format

Share Document