Comparative analysis of microRNA expression profiles in the colons of specific pathogen-free mice and germ-free mice

2021 ◽  
Author(s):  
Ayako Aoki ◽  
Reiji Aoki ◽  
Madoka Yatagai ◽  
Toshiyuki Kawasumi
Keyword(s):  
Gene Ontology ◽  
Comparative Analysis ◽  
Expression Profiles ◽  
Microrna Expression ◽  
Gene Ontology Analysis ◽  
Specific Pathogen Free ◽  
Germ Free ◽  
Mrna Targets ◽  
Significant Gene ◽  
Specific Pathogen

ABSTRACT MicroRNAs play an important role in microbiota–host crosstalk. In this study, we compared microRNA expression in whole colons of specific pathogen-free mice and germ-free mice. Forty-eight microRNAs were differentially expressed by more than 2-fold. Gene ontology analysis of the predicted mRNA targets revealed that the majority of the most significant gene ontology terms were related to GTPases and nerves.

Abstract WP120: MicroRNA Expression in Patients With Acute Ischemic Stroke

Stroke ◽  
2017 ◽  
Vol 48 (suppl_1) ◽  
Author(s):  
Janhavi M Modak ◽  
Meaghan A Roy-O’Reilly ◽  
Sarah E Conway ◽  
Liang Zhu ◽  
Louise D McCullough
Keyword(s):  
Ischemic Stroke ◽  
Differential Expression ◽  
Expression Profiles ◽  
Outpatient Setting ◽  
Microrna Expression ◽  
Neurological Deficits ◽  
Stroke Patients ◽  
Significant Differential Expression ◽  
Blood Samples ◽  
Mrna Targets

Background and Purpose: MicroRNAs (miRNAs) are a class of endogenous small non-coding ribonucleic acids that regulate gene expression and can impact cellular function by suppressing or activating downstream mRNA targets. Pre-clinical studies in animal models of stroke have demonstrated specific changes in miRNA expression profiles after ischemic stroke. Methods: Patients admitted to Hartford Hospital from January 2011 - March 2014 were considered for this study. Blood samples were collected within 24 hours of stroke presentation. miRNA profiles from peripheral blood samples of ischemic stroke patients were compared to controls. Patients with acute middle cerebral artery (MCA) cardioembolic strokes (based on TOAST criteria) were included (n=16). Blood collected from patients with no acute neurological deficits in an outpatient setting served as controls (n=8). Individuals with a history of active cancer, neoplastic brain lesions or traumatic brain injury were excluded. Based on literature review, 173 miRNAs were selected to assess for differential expression between cases and controls. miRNA profiling was conducted at Exiqon Services, Denmark, using miRCURY LNA™ microRNA Array. Statistical analysis was performed using SAS. Results: In patients with acute ischemic strokes, a statistically significant differential expression was observed in 14 miRNAs as compared to controls. MicroRNAs miR-1273e, miR-5187-3p were found to be downregulated in stroke patients (p=0.01). Other miRNAs showing a significant downregulation included let 7e-5p (p=0.03); miR-4709-3p, miR-4756-3p, miR-5584-3p, miR-647 (p=0.02); miR-4742-3p (p=0.03); miR-4764-5p, miR-4531 and miR-2116-5p (p=0.04). MicroRNAs miR-664a-3p (p=0.02), miR-943 (p=0.04) and miR-145-5p (p=0.03) were significantly upregulated. Differential expression in males and females was not observed. Conclusion: Ischemic stroke patients show a differential microRNA expression profile as compared to controls. Further studies can help identify microRNA signatures as well as the downstream targets involved in the ischemic stroke molecular cascade.

Abstract P112: Elevated Blood Pressure In Conventionalized Germ-free Rats Is Coupled With Upregulation Of Kynurenic Pathway Metabolites And Central Immune Responses

Hypertension ◽  
2020 ◽  
Vol 76 (Suppl_1) ◽  
Author(s):  
Tao Yang ◽  
Saroj Chakraborty ◽  
Piu Saha ◽  
Blair Mell ◽  
Xi Cheng ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Gene Ontology ◽  
Synaptic Plasticity ◽  
Cell Differentiation ◽  
Gut Microbiota ◽  
Immune Responses ◽  
Kynurenic Acid ◽  
Gene Ontology Analysis ◽  
Germ Free ◽  
Sd Rats

Background: Recent evidence supports that metabolic dysfunction underlies hypertension. Injection of kynurenate, a metabolite of tryptophan pathway, into the paraventricular nucleus of the hypothalamus (PVN) lowers blood pressure (BP). Intestinal absorption and metabolism of tryptophan are impacted by gut microbiota. Since gut-brain axis contributes to gut dysbiosis-inducd hypertension, we hypothesized that gut microbiota modulates the levels of kynurenic pathway metabolites that have central impact on BP regulation. Methods: We, for the first time, used 7 weeks old male Germ-free (GF) Spague Dawley (SD) rats (n=5) and GF rats co-housed with conventional SD rats for 10 days (GFC) (n=6). BP was measured by tail-cuff. Serum metabolites were quantified by 6495 triple quandrople mass spectrometryand data was normalized using isotoplic labelled compounds. The nucleus of the solitary tract (NTS), the principal sensory nucleus for peripheral changes, and the PVN, a relay center projecting sympathetic output based on the integrated afferent inputs from brain regions including NTS, were analyzed by microarray hybridization for mRNA expression. Results: Compared to the GF rats, GFC rats had significantly higher systolic (139 mmHg vs 115 mmHg, p <0.05), diastolic BP (96 mmHg vs 79 mmHg, p <0.05), and serum levels of kynurenic acid (-9.76 vs -10.21, p <0.05) and 3-hydroxy kynurenine (-6.49 vs -7.34, p <0.01). Coupled with these increases in kynurenic pathway metabolites, microarray analyses demonstrated increased immune responses (e.g. Cd74, Il1b, Cxcl1, Mmp14 ) in the PVN (gene ontology analysis, p <0.001) and increased cell differentiation and synaptic plasticity (e.g. Sox11, Tp53, Cdk6, Hoxb4, Foxo4, Cyr61 ) in the NTS (gene ontology analysis, p <0.01). Conclusion: Colonization of gut microbiota in GF rats induced increased cell differentiation and synaptic plasticity in the NTS and immune responses in the PVN, indicating the restructured sensory neurons of the NTS and enhanced sympathetic output from the PVN. These are in line with increased levels of kynurenic acid and 3-hydroxy kynurenine, and BP, respectively, suggesting that BP regulation by the gut-brain axis may be mediated by kynurenic pathway.

scholarly journals Microbiota Facilitates the Formation of the Aminated Metabolite of Tea Polyphenols Which Trap Deleterious Reactive Endogenous Metabolites (P06-022-19)

2019 ◽  
Vol 3 (Supplement_1) ◽  
Author(s):  
Shuwei Zhang ◽  
Yantao Zhao ◽  
Christina Ohland ◽  
Christian Jobin ◽  
Shengmin Sang
Keyword(s):  
Gut Microbiota ◽  
Chronic Diseases ◽  
Green Tea ◽  
Tea Polyphenols ◽  
Specific Pathogen Free ◽  
Tea Polyphenol ◽  
Germ Free ◽  
Specific Pathogen ◽  
Conjugated Metabolites

Abstract Objectives The in vivo mechanism of tea polyphenol-mediated prevention of many chronic diseases is still largely unknown. Studies have shown that accumulation of toxic reactive cellular metabolites, such as ammonia and reactive carbonyl species (RCS), is one of the causing factors to the development of many chronic diseases. The objective of this study is to investigated the in vivo interaction between tea polyphenols and ammonia and RCS. Methods In mice, we gave 200 mg/kg tea polyphenol ((-)-epigallocatechin-3-gallate (EGCG) or theaflavin) to CD-1 mice, 129/SvEv specific-pathogen-free (SPF) mice, or germ-free (GF) mice. Urinary and fecal samples were collected in metabolic cages for 24 h. In humans, two healthy volunteers drank 4 cups of Lipton green tea every day for four days. On the fourth day, 24 h urinary and fecal samples were collected after consuming the first cup of tea. Using LC tandem mass, we searched the formation of the aminated and RCS conjugated metabolites of tea polyphenols. Chemical standards were synthesized to confirm the structures of these metabolites. In order to study the impact of gut microbiota on the formation of these metabolites, we also quantified the concentrations of these metabolites in SPF and GF mice. Results We found that both EGCG and theaflavin could rapidly react with ammonia to generate the aminated metabolites. Both tea polyphenols and their aminated metabolites could further scavenge RCS, such as methylglyoxal (MGO), malondialdehyde (MDA), and trans-4-hydroxy-2-nonenal (4-HNE), to produce the RCS conjugates of tea polyphenols and the aminated tea polyphenols. Both the aminated and the RCS conjugated metabolites of EGCG were detected in human after drinking four cups of green tea per day. By comparing the levels of the aminated and the RCS conjugated metabolites in EGCG or theaflavin exposed germ-free (GF) mice and specific-pathogen-free (SPF) mice, we demonstrated that gut microbiota facilitate the formation of the aminated metabolites of tea polyphenols, the RCS conjugates of tea polyphenols, and the RCS conjugates of the aminated tea polyphenols. Conclusions Altogether, this study provides in vivo evidences that tea polyphenols have the capacity to scavenge toxic reactive metabolic wastes. This finding opens a new window to understand the underlying mechanisms by which drinking tea could prevent the development of chronic diseases. Funding Sources We gratefully acknowledge financial support from NIH R01 grant AT008623 to this work.

scholarly journals Effects of Breeding Environments on Generation and Activation of Autoreactive B-1 Cells in Anti-red Blood Cell Autoantibody Transgenic Mice

1997 ◽  
Vol 185 (4) ◽  
pp. 791-794 ◽  
Author(s):  
Masao Murakami ◽  
Kazuo Nakajima ◽  
Ken-ichi Yamazaki ◽  
Takehiko Muraguchi ◽  
Tadao Serikawa ◽  
...  
Keyword(s):  
Autoimmune Disease ◽  
Transgenic Mice ◽  
Blood Cell ◽  
Red Blood Cell ◽  
Bacterial Infections ◽  
Specific Pathogen Free ◽  
Germ Free ◽  
Conventional Condition ◽  
Specific Pathogen ◽  
Almost All

In anti-red blood cell autoantibody transgenic (autoAb Tg) mice almost all B cells are deleted except for B-1 cells in the peritoneal cavity and the gut. About one-half of the auto Ab Tg mice suffer from autoimmune hemolytic anemia (AIHA) in the conventional condition. Oral administration of lipopolysaccharides activates B-1 cells and induces autoimmune symptoms in the Tg mice, suggesting that the autoimmune disease in anti-RBC autoAb Tg mice is triggered by infections. To examine the association of bacterial infections with the generation of B-1 cells and the occurrence of the autoimmune disease, we analyzed anti-RBC autoAb Tg mice bred in germ-free and specific pathogen-free conditions. In germ-free conditions, few peritoneal B-1 cells were detected, while a significant number of peritoneal B-1 cells existed in specific pathogen-free conditions. In both conditions, no mice suffered from AIHA. However, when these Tg mice were transferred to the conventional condition or injected with lipopolysaccharide, peritoneal B-1 cells expanded and some of these mice suffered from AIHA. These results clearly showed that bacterial infections are responsible for both the expansion of B-1 cells and the onset of the autoimmune disease in these Tg mice.

scholarly journals Mice, Models, Microbiota: How Can We More Accurately Reflect Human Disease?

2021 ◽  
Vol 15 (1) ◽  
pp. 8
Author(s):  
Rahman Ladak ◽  
Dana Philpott
Keyword(s):  
Gut Microbiota ◽  
Translational Research ◽  
Mouse Models ◽  
Human Disease ◽  
Specific Pathogen Free ◽  
Germ Free ◽  
Stage Of Development ◽  
Specific Pathogen

With growing evidence that human disease is affected by the microbiota, many researchers have sought to modulate the microbiomes of mice to improve translational research. Altering their microbiomes, which are usually germ-free or specific pathogen-free, might allow mice to more accurately model human disease and hence produce more applicable findings. However, this has been difficult to apply to individual projects due to the disparity of explained methods and results. In this review, we first describe the immunological functions of the gut microbiota and the methods of altering mice microbiota, from transplantation route to age of transplantation to microbiota source. We then present an approach for how the gut microbiota might be considered when modelling human disease in mice. By organizing findings by type of disease - neurological, immunological, chronic inflammatory, and cancer - we propose that mouse models can be improved by considering the source of the microbiota, the presence or absence of certain microbial phyla, and by timing the transplantation during a physiologically relevant stage of development, such as the first five weeks of life.

Microbial regulation of a lincRNA–miRNA–mRNA network in the mouse hippocampus

Epigenomics ◽  
2020 ◽  
Vol 12 (16) ◽  
pp. 1377-1387
Author(s):  
Lanxiang Liu ◽  
Haiyang Wang ◽  
Ying Yu ◽  
Benhua Zeng ◽  
Xuechen Rao ◽  
...  
Keyword(s):  
Regulatory Network ◽  
Molecular Basis ◽  
Mapk Signaling ◽  
Specific Pathogen Free ◽  
Rna Transcription ◽  
Germ Free ◽  
Mouse Hippocampus ◽  
Specific Pathogen ◽  
Post Transcriptional Regulation ◽  
Mapk Signaling Pathways

Aim: To comprehensively understand microbiota-regulated lincRNA–miRNA–mRNA networks in psychiatric disorders. Materials & methods: Integrated analyses of lincRNAs, mRNAs and miRNAs, obtained by microarray analysis of hippocampus from specific pathogen-free, germ-free and colonized germ-free mice, were performed. Results: Expression of 139 mRNAs, seven miRNAs and one lincRNA was restored following colonization. The restored transcripts were mainly involved in CREB and Ras/MAPK signaling pathways. RNA transcription and post-transcriptional regulation were the primary perturbed functions. Finally, 12 lincRNAs, six miRNAs and 47 mRNAs were included in a lincRNA–miRNA–mRNA network, and lincRNA0926-miR-190a-5p-Celf4 interactions may play a pivotal role in this regulatory network. Conclusion: This study provides clues for understanding the molecular basis of gut microbiota–brain interactions in depressive- and anxiety-like behaviors.

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