ABSTRACT: To describe the transcriptional changes associated with polymicrobial-sepsis induced myocardial depression in wild type and iNOS deficient mice. Keywords: myocardium, contractility, differential gene expression, nitric oxide synthase, infection
Project description:To describe the transcriptional changes associated with polymicrobial-sepsis induced myocardial depression in wild type and iNOS deficient mice. Keywords: myocardium, contractility, differential gene expression, nitric oxide synthase, infection We compared the transcriptional profile of C57/BL6 WT mice and congenic B6 129P2-Nos2tm1Lau/J mice after 48 hrs of polymicrobial sepsis induced by caecal ligation and perforation. 48 hours after surgery, mice were anaesthetised (intraperitoneal 100 mg/kg ketamine and 10 mg/kg xylazine). The right common carotid artery was cannulated (Millar Mikro-Tip pressure transducing catheter: 1.4F sensor, 2F catheter; Houston TX). Pressure tracings from the aorta and left ventricle were recorded (SonoLAB software; Sonometrics Corp., London Ontario Canada) and analysed using Cardiosoft and Origin 6.0 (Sonometrics Corp., and Microcal Software, Northampton MA). The heart was removed, emptied of blood, and snap frozen.
Project description:We systematically assessed the transcriptomic changes of livers of MxCreFthD/D vs. Fthlox/lox mice after induction of polymicrobial sepsis using Cecal Ligation and Puncture. Data indicates a distinct set of genes differentially regulated between MxCreFthD/D and Fthlox/lox mice after sepsis induction reflecting altered iron and glucose metabolism.
Project description:Innate immunity is fundamental to recognition and clearance of bacterial infection. The relevant cells and molecules that orchestrate an effective response, however, remain incompletely understood. Here we describe a previously unknown population of B cells, which we have named innate response activator (IRA) B cells that recognize bacteria directly through TLR-4-MyD88 and protect against polymicrobial sepsis. IRA-B cells have a unique IgM high CD23 low CD43 + CD93+ GM-CSF+ signature, develop and diverge from B1a B cells, require BAFFR, and adhere to tissue via VLA-4 and LFA-1. B cell subsets are sorted from the spleen and peritoneum of C57BL/6 mice that were given intraperitoneal injections of LPS once daily for four days.
Project description:Sepsis is the leading cause of death in critically ill patients. While myocardial dysfunction has been recognized as a major manifestation in severe sepsis, the underlying molecular mechanisms associated with septic cardiomyopathy remain unclear. In this study, we performed a miRNA array analysis in hearts collected from a severe septic mouse model induced by cecal ligation and puncture (CLP). Among the 19 miRNAs that were dys-regulated in CLP-mouse hearts, miR-223(3p) and miR-223*(5p) were most significantly downregulated, compared with sham-operated mouse hearts. To test whether a drop of miR-223 duplex plays any roles in sepsis-induced cardiac dysfunction and inflammation, a knockout (KO) mouse model with a deletion of the miR-223 gene locus and wild-type (WT) mice were subjected to CLP or sham surgery. We observed that sepsis-induced cardiac dysfunction, inflammatory response and mortality were remarkably aggravated in CLP-treated KO mice, compared with control WTs. Using Western-blotting and luciferase reporter assays, we identified Sema3A, an activator of cytokine storm and a neural chemorepellent for sympathetic axons, as an authentic target of miR-223* in the myocardium. In addition, we validated that miR-223 negatively regulated the expression of STAT-3 and IL-6 in mouse hearts. Furthermore, injection of Sema3A protein into WT mice revealed an exacerbation of sepsis-triggered inflammatory response and myocardial depression, compared with control IgG1 protein-treated WT mice following CLP surgery. Taken together, these data indicate that loss of miR-223/-223* causes an aggravation of sepsis-induced inflammation, myocardial dysfunction and mortality. Our study uncovers a previously unrecognized mechanism underlying septic cardiomyopathy and thereby, may provide a new strategy to treat sepsis.
Project description:Innate immunity is fundamental to recognition and clearance of bacterial infection. The relevant cells and molecules that orchestrate an effective response, however, remain incompletely understood. Here we describe a previously unknown population of B cells, which we have named innate response activator (IRA) B cells that recognize bacteria directly through TLR-4-MyD88 and protect against polymicrobial sepsis. IRA-B cells have a unique IgM high CD23 low CD43 + CD93+ GM-CSF+ signature, develop and diverge from B1a B cells, require BAFFR, and adhere to tissue via VLA-4 and LFA-1.
Project description:Cardiac sarco(endo)plasmic reticulum calcium ATPase-2 (SERCA2) plays one of the central roles in myocardial contractility. Both, SERCA2 mRNA and protein are reduced in myocardial infarction (MI), but the correlation has not been always observed. MicroRNAs (miRNAs) act by targeting 3'-UTR mRNA, causing translational repression in physiological and pathological conditions, including cardiovascular diseases. The aim of our study was to identify miRNAs that could influence SERCA2 expression in human MI. The protein SERCA2 was decreased and 43 miRNAs were deregulated in infarcted myocardium compared to remote myocardium. miRNAs binding prediction to SERCA2 identified 213 putative miRNAs. TAM and miRNApath identified 18 functional and 21 diseased states related to heart diseases. Combing all results, we identified certain miRNAs as potential regulators of SERCA2. All the samples were stored as FFPE tissue and in RNAlater. Expression of SERCA2 was analyzed by western blot and miRNA expression was analyzed by microarrays and qPCR in samples of remote and infarcted myocardium from 6 patients who died of MI. Bioinformatic analysis including six prediction programmes (TargetScan, PicTar, miRBase, miRDB, Human MicroRNA Targets, and microrna.org), TAM and miRNApath annotation, and free-energy of binding (RNA22, RNAfold), was performed. Nine up-regulated miRNAs were analyzed for free-energy of binding and flanking regions, and nine miRNAs were used for validation with qPCR. Based on qPCR the comparison between FFPE and RNAlater as well as different reference genes was also performed.
Project description:Cardiac sarco(endo)plasmic reticulum calcium ATPase-2 (SERCA2) plays one of the central roles in myocardial contractility. Both, SERCA2 mRNA and protein are reduced in myocardial infarction (MI), but the correlation has not been always observed. MicroRNAs (miRNAs) act by targeting 3'-UTR mRNA, causing translational repression in physiological and pathological conditions, including cardiovascular diseases. The aim of our study was to identify miRNAs that could influence SERCA2 expression in human MI. The protein SERCA2 was decreased and 43 miRNAs were deregulated in infarcted myocardium compared to remote myocardium. miRNAs binding prediction to SERCA2 identified 213 putative miRNAs. TAM and miRNApath identified 18 functional and 21 diseased states related to heart diseases. Combing all results, we identified certain miRNAs as potential regulators of SERCA2.