Cardiac and vascular phenotypes in the apolipoprotein E-deficient mouse

Cardiovascular death is frequently associated with atherosclerosis, a chronic multifactorial disease and a leading cause of death worldwide. Genetically engineered mouse models have proven useful for the study of the mechanisms underlying cardiovascular diseases. The apolipoprotein E-deficient mouse has been the most widely used animal model of atherosclerosis because it rapidly develops severe hypercholesterolemia and spontaneous atherosclerotic lesions similar to those observed in humans. In this review, we provide an overview of the cardiac and vascular phenotypes and discuss the interplay among nitric oxide, reactive oxygen species, aging and diet in the impairment of cardiovascular function in this mouse model.     

Taurine induces proliferation of neural stem cells and synapse development in the developing mouse brain

Taurine is a sulfur-containing amino acid present in high concentrations in mammalian tissues. It has been implicated in several processes involving brain development and neurotransmission. However, the role of taurine in hippocampal neurogenesis during brain development is still unknown. Here we show that taurine regulates neural progenitor cell (NPC) proliferation in the dentate gyrus of the developing brain as well as in cultured early postnatal (P5) hippocampal progenitor cells and hippocampal slices derived from P5 mice brains. Taurine increased cell proliferation without having a significant effect on neural differentiation both in cultured P5 NPCs as well as cultured hippocampal slices and in vivo. Expression level analysis of synaptic proteins revealed that taurine increases the expression of Synapsin 1 and PSD 95. We also found that taurine stimulates the phosphorylation of ERK1/2 indicating a possible role of the ERK pathway in mediating the changes that we observed, especially in proliferation. Taken together, our results demonstrate a role for taurine in neural stem/progenitor cell proliferation in developing brain and suggest the involvement of the ERK1/2 pathways in mediating these actions. Our study also shows that taurine influences the levels of proteins associated with synapse development. This is the first evidence showing the effect of taurine on early postnatal neuronal development using a combination of in vitro, ex-vivo and in vivo systems.     

γδ T Cells Are Required for Pulmonary IL-17A Expression after Ozone Exposure in Mice: Role of TNFα

Ozone is an air pollutant that causes pulmonary symptoms. In mice, ozone exposure causes pulmonary injury and increases bronchoalveolar lavage macrophages and neutrophils. We have shown that IL-17A is important in the recruitment of neutrophils after subacute ozone exposure (0.3 ppm for 24–72 h). We hypothesized that γδ T cells are the main producers of IL-17A after subacute ozone. To explore this hypothesis we exposed wildtype mice and mice deficient in γδ T cells (TCRδ^−/−) to ozone or room air. Ozone-induced increases in BAL macrophages and neutrophils were attenuated in TCRδ^−/− mice. Ozone increased the number of γδ T cells in the lungs and increased pulmonary Il17a mRNA expression and the number of IL-17A⁺ CD45⁺ cells in the lungs and these effects were abolished in TCRδ^−/− mice. Ozone-induced increases in factors downstream of IL-17A signaling, including G-CSF, IL-6, IP-10 and KC were also decreased in TCRδ^−/− versus wildtype mice. Neutralization of IL-17A during ozone exposure in wildtype mice mimicked the effects of γδ T cell deficiency. TNFR2 deficiency and etanercept, a TNFα antagonist, also reduced ozone-induced increases in Il17a mRNA, IL-17A⁺ CD45⁺ cells and BAL G-CSF as well as BAL neutrophils. TNFR2 deficient mice also had decreased ozone-induced increases in Ccl20, a chemoattractant for IL-17A⁺ γδ T cells. Il17a mRNA and IL-17A⁺ γδ T cells were also lower in obese Cpe^fat versus lean WT mice exposed to subacute ozone, consistent with the reduced neutrophil recruitment observed in the obese mice. Taken together, our data indicate that pulmonary inflammation induced by subacute ozone requires γδ T cells and TNFα-dependent recruitment of IL-17A⁺ γδ T cells to the lung.     

Natural genetic variation in MIR172 isolated from Brassica species

The present study reports a natural variation in microRNA172 (MIR172) family members isolated from six species of genus Brassica. The analysis of nucleotide polymorphism across 44 Brassica MIR172 homologs revealed a higher conservation in the predicted precursors relative to flanking regions. Single nucleotide polymorphisms (SNPs) were detected in miRNA and miRNA*. The 21-nt miRNA sequence was conserved in all MIR172 members except MIR172a. However, the miRNA* sequence was conserved only in MIR172a compared to A. thaliana. Non-canonical Brassica variants of precursor miR172a were detected wherein SNP at 5′ terminal in mature miR172a resulted in a sequence identical to mature miR172e. SNPs and indels in precursors resulted in varied stem-loop structures of differing stabilities (ΔG) implying a differential efficiency of miRNA biogenesis. A sequence based phylogram revealed ortholog specific groupings of MIR172 irrespective of genetic background. A Northern analysis in Brassica juncea displayed the cumulative expression of miR172 isoforms in all tissues representing different developmental stages with levels gradually increasing from vegetative to reproductive stages. Detection of high content of miR172 in roots indicates the possibility of additional roles of Brassica miR172 in root development.     

Proteases in germinating finger millet (Eleusine coracana) seeds

Proteolytic activity was estimated in germinated finger millet seedlings using the endogenous trypsin/amylase inhibitor as substrate and also with haemoglobin and albumin as substrates. The maximal proteolytic activity was observed on the third day of germination. With the inhibitor as substrate, the proteolytic activity was maximal at pH 2.5. The protease that acted on the inhibitor required sulphydryl groups for maximal activity and was suppressed by diazoacetyl norleucine methyl ester and Pepstatin. The protease that acted on haemoglobin with optimum pH of 5.0, was more stable on storage, did not depend on sulphydryl groups for activity and was unaffected by reagents that react with carboxyl groups.     

Identification of pathogenic fungi in surgical and autopsy specimens by immunofluorescence

Summary A method is presented for the preparation of immune sera and detection by immunofluorescence ofC. immitis, S. schenckii, B. dermatitidis, C. neoformans, andC. albicans in surgical and autopsy material. Formalin fixation does not affect the antigens of the mycotic agents. There are no cross reactions except withC. immitis andC. neoformans, which can be differentiated by the site of the specific fluorescence in each organism.     

EDC3 phosphorylation regulates growth and invasion through controlling P‐body formation and dynamics

Regulation of mRNA stability and translation plays a critical role in determining protein abundance within cells. Processing bodies (P‐bodies) are critical regulators of these processes. Here, we report that the Pim1 and 3 protein kinases bind to the P‐body protein enhancer of mRNA decapping 3 (EDC3) and phosphorylate EDC3 on serine (S)161, thereby modifying P‐body assembly. EDC3 phosphorylation is highly elevated in many tumor types, is reduced upon treatment of cells with kinase inhibitors, and blocks the localization of EDC3 to P‐bodies. Prostate cancer cells harboring an EDC3 S161A mutation show markedly decreased growth, migration, and invasion in tissue culture and in xenograft models. Consistent with these phenotypic changes, the expression of integrin β1 and α6 mRNA and protein is reduced in these mutated cells. These results demonstrate that EDC3 phosphorylation regulates multiple cancer‐relevant functions and suggest that modulation of P‐body activity may represent a new paradigm for cancer treatment.