Project description:Metabolic products of the microbiota can alter hematopoiesis. However, the contribution and site of action of bile acids is poorly understood. Here we demonstrate that the secondary bile acids, deoxycholic acid (DCA), and lithocholic acid (LCA) increase bone marrow myelopoiesis. Treatment of bone marrow cells with DCA and LCA preferentially expanded immunophenotypic and functional (CFU-GM) granulocyte-monocyte progenitors (GMPs). DCA treatment of sorted hematopoietic stem/progenitor cells (HSPCs) increased CFU-GMs, indicating that direct exposure of HSPCs to DCA sufficed to expand GMPs. We determined that the vitamin D receptor (VDR) was required for the DCA-induced increase in CFU-GMs and GMPs. Finally, single-cell RNA sequencing revealed that DCA significantly upregulated genes associated with myeloid differentiation and proliferation in GMPs. The action of DCA on HSPCs to expand GMPs in a VDR-dependent manner suggests a mechanism for how microbiome-host interactions may directly impact bone marrow hematopoiesis and the severity of infectious and inflammatory disease.
Project description:The gut microbiome can impact brain health and is altered in Parkinson’s disease (PD) patients. The vermiform appendix is a lymphoid tissue implicated in the storage and regulation of the gut microbiome. Here, we investigate changes in the functional microbiome in the appendix of PD patients relative to controls by metatranscriptomic analysis. In the PD appendix, we find microbial dysbiosis affecting lipid metabolism, particularly an upregulation of bacteria responsible for secondary bile acid synthesis. Likewise, proteomic and transcript analysis in the PD gut corroborates a disruption in cholesterol homeostasis and lipid catabolism. Bile acid analysis in the PD appendix reveals an increase in the microbially-derived, toxic secondary bile acids deoxycholic acid (DCA) and lithocholic acid (LCA). Synucleinopathy in mice induces similar microbiome alterations to those of PD patients and heightens microbial changes to gut inflammation. As observed in PD, the mouse model of synucleinopathy has elevated DCA and LCA. Raised levels of DCA and LCA can lead to liver injury, and an analysis of blood markers of liver dysfunction shows evidence of biliary abnormalities in PD patients, including elevated alkaline phosphatase and bilirubin. Increased bilirubin levels are also evident before PD diagnosis, in individuals at-risk of developing PD. In sum, microbially-derived toxic bile acids are heightened in PD and biliary changes may even precede the onset of overt motor symptoms.
Project description:The gut microbiome can impact brain health and is altered in Parkinson’s disease (PD) patients. The vermiform appendix is a lymphoid tissue implicated in the storage and regulation of the gut microbiome. Here, we investigate changes in the functional microbiome in the appendix of PD patients relative to controls by metatranscriptomic analysis. In the PD appendix, we find microbial dysbiosis affecting lipid metabolism, particularly an upregulation of bacteria responsible for secondary bile acid synthesis. Likewise, proteomic and transcript analysis in the PD gut corroborates a disruption in cholesterol homeostasis and lipid catabolism. Bile acid analysis in the PD appendix reveals an increase in the microbially-derived, toxic secondary bile acids deoxycholic acid (DCA) and lithocholic acid (LCA). Synucleinopathy in mice induces similar microbiome alterations to those of PD patients and heightens microbial changes to gut inflammation. As observed in PD, the mouse model of synucleinopathy has elevated DCA and LCA. Raised levels of DCA and LCA can lead to liver injury, and an analysis of blood markers of liver dysfunction shows evidence of biliary abnormalities in PD patients, including elevated alkaline phosphatase and bilirubin. Increased bilirubin levels are also evident before PD diagnosis, in individuals at-risk of developing PD. In sum, microbially-derived toxic bile acids are heightened in PD and biliary changes may even precede the onset of overt motor symptoms.
Project description:Effect of bile acids (TCA LCA TUDCA DCA) on isolated bacteria
Ruminococcus bromii, Bacteroides fragilis, and Lactobacillus paracasei
Project description:In this study, we aimed at the characterization of C. difficile’s stress response to the main four human bile acids. Although, a phenotypically description of growth differences upon challenge with different bile acids has been described (Lewis 2016, Thanissery 2017), there is no information on the adaptation of gene expression available. We employed a comprehensive proteomics approach to record stress signatures of the unconjugated bile acids CA, CDCA, DCA and LCA during long-term-stress conditions and could depict a general stress response concerning all four bile acids, but also specific responses to only a single or a few of the different bile acids. Our results are a starting point for the understanding of how the individual bile acids cocktail of a patient can decide on the outcome of a C. difficile infection
Project description:In this study, we aimed at the characterization of C. difficile’s stress response to the main four human bile acids. Although, a phenotypically description of growth differences upon challenge with different bile acids has been described (Lewis 2016, Thanissery 2017), there is no information on the adaptation of gene expression available. We employed a comprehensive proteomics approach to record stress signatures of the unconjugated bile acids CA, CDCA, DCA and LCA in shock experiments as well as during long-term-stress conditions and could depict a general stress response concerning all four bile acids, but also specific responses to only a single or a few of the different bile acids. Our results are a starting point for the understanding of how the individual bile acids cocktail of a patient can decide on the outcome of a C. difficile infection.
Project description:Epithelial Ovarian Cancer (EOC) is the leading cause of gynecologic cancer death. Despite many patients achieving remission with first-line therapy, up to 80% of patients will recur and require additional treatment. Retrospective clinical analysis of OC patients indicates antibiotic use during chemotherapy treatment is associated with poor overall survival. We assessed whether antibiotic (ABX) therapy would impact growth of EOC and sensitivity to cisplatin in murine models. Immune competent or compromised mice were given control or ABX containing water (metronidazole, ampicillin, vancomycin, and neomycin) before being intraperitoneally injected with murine EOC cells. Stool was collected to confirm microbiome disruption and tumors were monitored, and cisplatin therapy was administered weekly until endpoint. EOC tumor-bearing mice demonstrate accelerated tumor growth and resistance to cisplatin therapy in ABX treated compared with nonABX treatment. Stool analysis indicated most gut microbial species were disrupted by ABX treatment except for ABX resistant bacteria. To test for role of the gut microbiome, cecal microbiome transplants (CMTs) of microbiota derived from ABX or nonABX treated mice were used to recolonize the microbiome of ABX treated mice. nonABX cecal microbiome was sufficient to ameliorate the chemoresistance and survival of ABX treated mice indicative of a gut derived tumor suppressor. Mechanistically, tumors from ABX treated compared to nonABX treated mice contained a high frequency of cancer stem cells that were augmented by cisplatin. These studies indicate an intact microbiome provides a gut derived tumor suppressor and maintains chemosensitivity that is disrupted by ABX treatment.
Project description:Antibiotic-treated (ABX) mice exhibit an impaired innate and adaptive antiviral immune response and substantially delayed viral clearance following exposure to systemic LCMV or mucosal influenza virus. Genome-wide transcriptional profiling of macrophages isolated from ABX mice revealed decreased expression of genes associated with antiviral immunity. Moreover, macrophages from ABX mice exhibited defective responses to type I and type II IFNs and impaired capacity to limit viral replication. Collectively, these data indicate that commensal-derived signals provide tonic immune stimulation that establishes the activation threshold of the innate immune system required for optimal antiviral immunity. In this study, we performed gene expression profiling to compare the transcriptional signatures of macrophages isolated from mice exposed to commensal bacteria-derived signals to macrophages isolated from mice depleted of commensal bacteria. Peritoneal macrophages (CD3ε-, CD5-, CD19-, CD11b+, F4/80+) from naïve CNV or ABX mice were sorted directly into TRIzol (Invitrogen) on a BD Aria (Beckson Dickson). Test sorts were �95% pure. For microarray analysis, RNA was extracted from 3 sorted biological replicates of peritoneal macrophages from naïve CNV or ABX mice. cDNA was amplified using NuGen WT Ovation Pico kit and hybridized to Affymetrix GeneChip Mouse Gene 1.0 ST microarrays