Project description:The purpose of this study was to evaluate the effect of endotoxemia on brown adipose tissue by injection of ultrasonicated P. gingivalis to mice
Project description:Improvement of obesity is important for increasing longevity. The characteristics, size, and function of adipocytes are altered in patients with obesity. Adipose tissue is not only an energy storage but also an endocrine organ. Alteration of endocrine activities in adipose tissue, among them the functional decline of brown adipose tissue (BAT), is associated with obesity. Periodontal disease is a risk factor for systemic diseases since endotoxemia is caused by periodontal bacteria. However, the effect of periodontal disease on obesity remains unclear. Thus, this study aimed to investigate the effect of endotoxemia due to Porphyromonas gingivalis, a prominent cause of periodontal disease, on the BAT. Herein, endotoxemia was induced in 12-week-old C57BL/6J mice through intravenous injection of sonicated 108 CFU of P. gingivalis (Pg) or saline (control [Co]) once. Eighteen hours later, despite no inflammatory M1 macrophage infiltration, inflammation-related genes were upregulated exclusively in the BAT of Pg mice compared with Co mice. Although no marked histological changes were observed in adipose tissues, expressions of genes related to lipolysis, Lipe and Pnpla2 were downregulated after P. gingivalis injection in BAT. Furthermore, expression of Pparg and Adipoq was downregulated only in the BAT but not in the white adipose tissues, along with downregulation of Ucp1 and Cidea expression, which are BAT-specific markers, in Pg mice. Microarray analysis of the BAT showed 106 differentially expressed genes between Co and Pg mice. Gene set enrichment analysis revealed that the cholesterol homeostasis gene set and PI3/Akt/mTOR signaling gene set in BAT were downregulated, whereas the TGF-β signaling gene set was enriched in Pg mice. Overall, intravenous injection of sonicated P. gingivalis altered the endocrine functions of the BAT in mice. This study indicates that endotoxemia by P. gingivalis potentially affects obesity by disrupting BAT function.
Project description:Porphyromonas gingivalis is a major pathogen associated with the microbial biofilm-mediated disease chronic periodontitis. P. gingivalis has an obligate requirement for iron and protoporphyrin IX which it satisfies by transporting heme and iron liberated from the human host. The level of cellular iron in P. gingivalis affects the expression of a distinct iron-associated regulon of 64 genes and low iron invokes an iron sparing response. Iron homeostasis is usually mediated in Gram-negative bacteria at the transcriptional level by the Ferric Uptake Regulator (Fur). There is a single predicted P. gingivalis Fur superfamily orthologue named Har (heme associated regulator) that lacks the conserved metal binding residues found in other Fur orthologues. We show that Har binds both heme and ferrous iron resulting in a conformational change in the protein. Har was unable to complement the Escherichia coli H1780 fur mutant and there was no change in cellular metal content in a P. gingivalis Har mutant compared with the wild-type. The Har regulon of 44 genes is not predicted to play a role in iron homeostasis. Together these data indicated that Har does not regulate iron homeostasis in P. gingivalis. However, Har was required for heme-responsive biofilm development and its regulon overlapped P. gingivalis regulons previously identified after growth in heme limitation or as a homotypic biofilm. P. gingivalis is unique as an iron-dependent Gram-negative bacterium with a single heme-binding Fur superfamily orthologue, Har, that does not regulate iron homeostasis.
Project description:Liver has a crucial role in the regulation of immune defense in systemic infections. During endotoxemia, the liver transits from an immune-tolerant towards an immune-active state and forms the first line of defense against invading microorganisms. the role of liver parenchymal cells in endotoxemia remains unintelligible. To characterize the liver parenchymal cells in endotoxemia liver, we performed single-cell RNA sequencing of liver parenchymal cells from healthy C57BL/6J mice and murine model of endotoxemia at early or late stage. The single-cell RNA-seq analyses revealed the heterogeneity of liver parenchymal cells in endotoxemia liver.
Project description:Liver has a crucial role in the regulation of immune defense in systemic infections. During endotoxemia, the liver transits from an immune-tolerant towards an immune-active state and forms the first line of defense against invading microorganisms. the role of liver nonparenchymal cells in endotoxemia remains unintelligible. To characterize the liver nonparenchymal cells in endotoxemia liver, we performed single-cell RNA sequencing of liver nonparenchymal cells from healthy C57BL/6J mice and murine model of endotoxemia at early or late stage. The single-cell RNA-seq analyses revealed the heterogeneity of liver nonparenchymal cells in endotoxemia liver.
Project description:Porphyrmonas gingivalis is an oral pathogen associated with the inflammatory disease periodontitis. The colonization of oral epithelial surfaces by P. gingivalis may also lead to the autoimmune disease rheumatoid arthritis. One of the hallmarks of rheumatoid arthritis is the loss of tolerance against citrullinated proteins. Citrullination is a post-translational modification of arginine residues, leading to a change in structure and function of the respective protein. This modification is catalysed by peptidylarginine deiminases (PAD). Interestingly, P. gingivalis secretes a citrullinating enzyme, known as P. gingivalis PAD (PPAD), which targets bacterial and human proteins. Since the extent of P. gingivalis protein citrullination by PPAD was not yet known, the present study was aimed at identifying the extracellular proteome and citrullinome of P. gingivalis. To this end, extracellular proteins of two reference strains, two PPAD-deficient mutants and three clinical isolates of P. gingivalis were analysed by mass spectrometry. The results uncovered substantial heterogeneity in the extracellular proteome and citrullinome of P. gingivalis, especially in relation to the extracellular detection of typical cytoplasmic proteins. In contrast, major virulence factors were identified in all investigated isolates although their citrullination was shown to vary. This may be related to post-translational processing of the PPAD enzyme.
Project description:Porphyromonas gingivalis is a major pathogen associated with the microbial biofilm-mediated disease chronic periodontitis. P. gingivalis has an obligate requirement for iron and protoporphyrin IX which it satisfies by transporting heme and iron liberated from the human host. The level of cellular iron in P. gingivalis affects the expression of a distinct iron-associated regulon of 64 genes and low iron invokes an iron sparing response. Iron homeostasis is usually mediated in Gram-negative bacteria at the transcriptional level by the Ferric Uptake Regulator (Fur). There is a single predicted P. gingivalis Fur superfamily orthologue named Har (heme associated regulator) that lacks the conserved metal binding residues found in other Fur orthologues. We show that Har binds both heme and ferrous iron resulting in a conformational change in the protein. Har was unable to complement the Escherichia coli H1780 fur mutant and there was no change in cellular metal content in a P. gingivalis Har mutant compared with the wild-type. The Har regulon of 44 genes is not predicted to play a role in iron homeostasis. Together these data indicated that Har does not regulate iron homeostasis in P. gingivalis. However, Har was required for heme-responsive biofilm development and its regulon overlapped P. gingivalis regulons previously identified after growth in heme limitation or as a homotypic biofilm. P. gingivalis is unique as an iron-dependent Gram-negative bacterium with a single heme-binding Fur superfamily orthologue, Har, that does not regulate iron homeostasis. Paired samples were compared on the same microarray using a two-colour system. A total of 6 paired microarray hybridizations were performed representing 6 biological replicates, where a balanced dye design was used, with the overall analysis including three microarrays where P. gingivalis 33277 samples were labeled with Cy3 and the paired ECR455 samples were labeled with Cy5 and three other microarrays where samples were labeled with the opposite combination of fluorophores.
Project description:Genotyping studies suggest that there is genetic variability among P. gingivalis strains, however the extent of variability remains unclear, and the regions of variability have only partially been identified. We previously used heteroduplex analysis of the ribosomal operon intergenic spacer region (ISR) to type P. gingivalis strains in several diverse populations, identifying 6 predominant heteroduplex types and many minor ones. In addition we used ISR sequence analysis to determine the relatedness of P. gingivalis strains to one another, and demonstrated a link between ISR sequence phylogeny and the disease-associated phenotype of P. gingivalis strains. The availability of whole genome microarrays based on the genomic sequence of strain W83 has allowed a more comprehensive analysis of P. gingivalis strain variability, using the entire genome. The objectives of this study were to define the phylogeny of P. gingivalis strains using the entire genome, to compare the phylogeny based on genome content to the phylogeny based on a single locus (ISR), and to identify genes that are associated with the strongly disease-associated strain W83 that could be important for virulence. Keywords: Comparative genomic hybridization
Project description:EXPERIMENT: Microarray expression profiles derived from the human primary gingival epithelial cells 24.0h after exposure to heat inactivated P. gingivalis ANIMAL MODEL: NON EXPOSURE: Human primary gingival epithelial cells (at 3rd passage) were exposed to heat inactivated P. gingivalis (MOI:100) at 90% confluence. Two types of gingival epithelial cells were used. One with Normal cytokine inducer type (at least 2 fold IL-6/TNF-alpha/IL-1ß when challenged with TLR2/4 agonists) and the other with diminished cytokine inducer type (no change in IL-6/TNF-alpha/IL-1ß when challenged with TLR2/4 agonists). INTERVAL: NON. PLATFORM: microRNA expression profile in gingival epithelial cells - miRCURY LNA™ microRNA Arrays (Exiqon). The RNA samples were subjected to microarray on 8/9/2007 Keywords = Human primary gingival epithelial cells Keywords = P. gingivalis Keywords = Periodontitis Keywords: Ordered
Project description:EXPERIMENT: Microarray expression profiles derived from the human primary gingival epithelial cells 24.0h after exposure to heat inactivated P. gingivalis ANIMAL MODEL: NON EXPOSURE: Human primary gingival epithelial cells (at 3rd passage) were exposed to heat inactivated P. gingivalis (MOI:100) at 90% confluence. Two types of gingival epithelial cells were used. One with Normal cytokine inducer type (at least 2 fold IL-6/TNF-alpha/IL-1à when challenged with TLR2/4 agonists) and the other with diminished cytokine inducer type (no change in IL-6/TNF-alpha/IL-1à when challenged with TLR2/4 agonists). INTERVAL: NON. PLATFORM: microRNA expression profile in gingival epithelial cells - miRCURY LNA⢠microRNA Arrays (Exiqon). The RNA samples were subjected to microarray on 8/9/2007 Keywords = Human primary gingival epithelial cells Keywords = P. gingivalis Keywords = Periodontitis Keywords: Ordered The effect of heat inactivated P. gingivalison human primary gingival epithelial cells were assayed.