Gene expression profiles following intracoronary injection of mesenchymal stromal cells using a porcine model of chronic myocardial infarction.

BACKGROUND AIMS: We evaluated the therapeutic potential of injection of in vitro differentiated bone marrow mesenchymal stromal cells (MSC) using a swine model. METHODS AND RESULTS: Myocardial infarction was induced by coronary occlusion. Three groups (n = 5 each) were analyzed: one group received an injection of 17.8 ± 9.3 × 10(6) 5-azacytidine-treated allogeneic MSC 1 month after infarction; a placebo group received an injection of medium; and controls were kept untreated. After 4 weeks, heart samples were taken from three infarcted areas, interventricular septa, ventricles and atria. Gene expression profiles of genes related to contractility (Serca2a), fibrosis (Col1a1), cardiomyogenesis (Mef2c, Gata4 and Nkx2.5) and mobilization of stem cells (Sdf1, Cxcr4 and c-kit) were compared by quantitative real-time PCR (qRT-PCR). Gene expression profiles varied in different heart areas. Thus Serca2a expression was reduced in infarcted groups in all heart regions except for the left ventricles, where Col1a1 was overexpressed. The expression of genes related to cardiomyogenesis decreased in the infarcted zones and left atria compared with healthy hearts. Interestingly, increased expression of Cxcr4 was detected in infarcted regions of MSC-treated pigs compared with the placebo group. CONCLUSIONS: Infarction induced changes in expression of genes involved in various biologic processes. Genes involved in cardiomyogenesis were downregulated in the left atrium. The intracoronary injection of MSC resulted in localized changes in the expression of Cxcr4.

The Ve-mediated resistance response of the tomato to Verticillium dahliae involves H2O2, peroxidase and lignins and drives PAL gene expression.

BACKGROUND: Verticillium dahliae is a fungal pathogen that infects a wide range of hosts. The only known genes for resistance to Verticillium in the Solanaceae are found in the tomato (Solanum lycopersicum) Ve locus, formed by two linked genes, Ve1 and Ve2. To characterize the resistance response mediated by the tomato Ve gene, we inoculated two nearly isogenic tomato lines, LA3030 (ve/ve) and LA3038 (Ve/Ve), with V. dahliae. RESULTS: We found induction of H2O2 production in roots of inoculated plants, followed by an increase in peroxidase activity only in roots of inoculated resistant plants. Phenylalanine-ammonia lyase (PAL) activity was also increased in resistant roots 2 hours after inoculation, while induction of PAL activity in susceptible roots was not seen until 48 hours after inoculation. Phenylpropanoid metabolism was also affected, with increases in ferulic acid, p-coumaric acid, vanillin and p-hydroxybenzaldehyde contents in resistant roots after inoculation. Six tomato PAL cDNA sequences (PAL1 - PAL6) were found in the SolGenes tomato EST database. RT-PCR analysis showed that these genes were expressed in all organs of the plant, albeit at different levels. Real-time RT-PCR indicated distinct patterns of expression of the different PAL genes in V. dahliae-inoculated roots. Phylogenetic analysis of 48 partial PAL cDNAs corresponding to 19 plant species grouped angiosperm PAL sequences into four clusters, suggesting functional differences among the six tomato genes, with PAL2 and PAL6 presumably involved in lignification, and the remaining PAL genes implicated in other biological processes. An increase in the synthesis of lignins was found 16 and 28 days after inoculation in both lines; this increase was greater and faster to develop in the resistant line. In both resistant and susceptible inoculated plants, an increase in the ratio of guaiacyl/syringyl units was detected 16 days after inoculation, resulting from the lowered amount of syringyl units in the lignins of inoculated plants. CONCLUSIONS: The interaction between the tomato and V. dahliae triggered a number of short- and long-term defensive mechanisms. Differences were found between compatible and incompatible interactions, including onset of H2O2 production and activities of peroxidase and PAL, and phenylpropanoid metabolism and synthesis of lignins.

Innate immune gene expression in individual zebrafish after Listonella anguillarum inoculation.

Zebrafish were intraperitoneally injected with 10(6)CFU (LD50) Listonella anguillarum. Three inoculated and control fish were collected at 1, 2, 4, 6 and 22h post infection (hpi) and the expression of genes related to the immune response (il1b, cebpb, tfa, mpx, tnfa, nitr9, tlr22, hsc70, cp, mrlp1, c3b and lyz) in each fish was monitored by means of real-time RT-PCR. A similar experiment was performed considering an intermediate time point at 15 hpi. Different relative levels of expression were found among genes. Also, wide interindividual variation in gene expression for most genes was detected among fish, inoculated or not. A steady increase of expression starting from the initial stages of the interaction was found for interleukin-1beta. An initial increase in levels of gene expression was found for the genes coding for the CCAAT/Enhancer Binding Protein subunit beta and the Novel Immune-Type Receptor 9, although their levels decreased later on and were indistinguishable from the controls at 22 hpi. Finally, some genes (Transferrin, Myeloid-specific Peroxidase and Tumour Necrosis Factor alpha) were upregulated at 22 hpi. Taken together, our results show an induction in gene expression of genes involved in the inflammatory and immune response upon L. anguillarum infection but also reveal the existence of a wide variation in the levels of expression of the studied genes in the zebrafish population.