Cytokine signaling by grafted neuroectodermal stem cells rescues motoneurons destined to die

Following an injury to their axons close to the cell body, adult motoneurons generally die. This type of injury, typically caused by avulsion of the spinal ventral root, initiates the activation of astrocytes and microglial cells and the extracellular space becomes loaded with excessive amounts of excitotoxic glutamate. We have provided evidence that, following ventral root avulsion and reimplantation, murine embryonic neuroectodermal stem cells (NE-GFP-4C) grafted into the rat spinal cord rescue the vast majority of the motoneurons that would otherwise die, and enable them to reinnervate peripheral targets. Stem cell grafts produced the modulatory cytokines IL-1-alpha, IL-6, IL-10, TNF-alpha and MIP-1-alpha, but not neurotrophic factors. The neurons and astrocytes in the ventral horn of grafted animals also produced IL-6 and MIP-1-alpha, indicating a strong interaction between the graft and the host tissue. The infusion of function-blocking antibodies against all cytokines into the grafted cords completely abolished their motoneuron-rescuing effect, while neutralization of only IL-10 suggested its strong effectivity as concerns motoneuron survival and a milder effect on reinnervation. It is suggested that, apart from the anti-inflammatory function of IL-10, the pro-inflammatory cytokines produced exert a strong modulatory function in the CNS, promoting the prevention of neuronal cell death

Downregulation of cellular protective factors of rumen epithelium in goats fed high energy diet.

Energy-rich diets can challenge metabolic and protective functions of the rumen epithelial cells, but the underlying factors are unclear. This study sought to evaluate proteomic changes of the rumen epithelium in goats fed a low, medium, or high energy diet. Expression of protein changes were compared by two-dimensional differential gel electrophoresis followed by protein identification with matrix assisted laser desorption ionisation tandem time-of-flight mass spectrometry. Of about 2,000 spots commonly detected in all gels, 64 spots were significantly regulated, which were traced back to 24 unique proteins. Interestingly, the expression profiles of several chaperone proteins with important cellular protective functions such as heat shock cognate 71 kDa protein, peroxiredoxin-6, serpin H1, protein disulfide-isomerase, and selenium-binding protein were collectively downregulated in response to high dietary energy supply. Similar regulation patterns were obtained for some other proteins involved in transport or metabolic functions. In contrast, metabolic enzymes like retinal dehydrogenase 1 and ATP synthase subunit beta, mitochondrial precursor were upregulated in response to high energy diet. Lower expressions of chaperone proteins in the rumen epithelial cells in response to high energy supply may suggest that these cells were less protected against the potentially harmful rumen toxic compounds, which might have consequences for rumen and systemic health. Our findings also suggest that energy-rich diets and the resulting acidotic insult may render rumen epithelial cells more vulnerable to cellular damage by attenuating their cell defense system, hence facilitating the impairment of rumen barrier function, typically observed in energy-rich fed ruminants

Manipulation of viral protein production using the PCNA of halovirus фCh1 via alternative start codon usage

Proliferating Cell Nuclear Antigen (PCNA) is a scaffold protein principally found at the centre of replication, coordinating with a wide array of interaction partners. cpCh1, unusually for a virus, encodes a putative PCNA. Natrialba magadii, the only known host of cpCh1, also encodes a putative PCNA of high sequence similarity, differing in the presence of an alternate GUG start codon 5\u27 of the AUG start codon resulting in a larger protein. Homologous recombination was used to delete the viral PCNA gene. Complementation and overexpression strains with plasmid expressed viral PCNA variants were created and analyzed for growth and lytic behaviour, viral protein levels, and virus titer. Deletion of cpCh1 ORF59, encoding PCNAoCh1 resulted in a significant reduction in the virus titer, reduced viral protein load, and reduced lysis. Complementation and overexpression with WT and mutant variants of ORF59 revealed that modification of the GTG start codon to ATG changes the life cycle in terms of production of progeny virus particles. The different variants have a broad range of variable effects on each of the phenotypes observed. Experiments with a halophilic betagalactosidase assay revealed a cis/trans mediated interaction between the viral PCNA and the origin of replication of cpCh1 modulated by the 5\u27GTG to ATG sequence. The virally encoded PCNA is not essential, but is crucial, to the life cycle of the virus cpCh1. The 5\u27 region upstream of the primary AUG codon and its regulation with an alternate start codon is essential to the homeostasis of the virus-host relationship

Relative mRNA expression of target genes in the rumen epithelium of goats.

<p>Animals were fed three different diets (white colour, low energy diet; gray color, medium energy diet; black colour, high energy diet). The mRNA expression of target genes was calculated relative to the expression of <i>ACTB</i> and <i>HPRT1</i>. Abbreviations of the genes are: HRG  =  Histidine-rich glycoprotein, NDK7 (NME2)  =  Nucleoside diphosphate kinase, HSPA8  =  Heat shock cognate 71 kDa, SERPINH1(HSP47)  =  Serpin H1, SELENBP1  =  Selenium-binding protein 1, TPI  =  Triosephosphate isomerise, ALDH1A  =  Aldehyde dehydrogenase1 family member A1, ATP5B  =  ATP synthase subunit beta, PRDX6  =  Peroxiredoxin 6, TF  =  Transferrin, Albumin  =  Albumin precursor, ACTB  =  β-actin, HPRT1  =  Hypoxanthine phosphoribosyltransferase. ^abc indicate difference at <i>P</i><0.05.</p

Summary of differentially expressed and identified spots from 2D-DIGE gels of rumen epithelium of goats fed diets differing in the energy supply.

1<p>L  =  low energy diet; M  =  medium energy diet, H  =  high energy diet.</p>2<p>At least 30% difference in expression.</p

Representative 2DE-DIGE gel image of differentially expressed proteins after silver staining.

<p>Numbers correspond to the identified proteins in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0081602#pone-0081602-t002" target="_blank"> 2</a>.</p

Differentially expressed proteins in the rumen epithelium of goats fed diets differing in the energy supply¹.

1<p>L  =  low energy diet; M  =  medium energy diet, H  =  high energy diet.</p>2<p>Numbers correspond to the labelled spots in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0081602#pone-0081602-g001" target="_blank">Figure 1</a>.</p>3<p>Sequence coverage (%).</p>4<p>Accession number in NCBI (National Center for Biotechnology Information) and SwissProt database.</p>5<p>Fragment.</p><p>**different at <i>P</i><0.01.</p><p>*different at <i>P</i><0.05.</p

mtDNA Segregation in Heteroplasmic Tissues Is Common In Vivo and Modulated by Haplotype Differences and Developmental Stage

The dynamics by which mitochondrial DNA (mtDNA) evolves within organisms are still poorly understood, despite the fact that inheritance and proliferation of mutated mtDNA cause fatal and incurable diseases. When two mtDNA haplotypes are present in a cell, it is usually assumed that segregation (the proliferation of one haplotype over another) is negligible. We challenge this assumption by showing that segregation depends on the genetic distance between haplotypes. We provide evidence by creating four mouse models containing mtDNA haplotype pairs of varying diversity. We find tissue-specific segregation in all models over a wide range of tissues. Key findings are segregation in postmitotic tissues (important for disease models) and segregation covering all developmental stages from prenatal to old age. We identify four dynamic regimes of mtDNA segregation. Our findings suggest potential complications for therapies in human populations: we propose “haplotype matching” as an approach to avoid these issues