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BackgroundMultiple sclerosis is a widespread inflammatory demyelinating disease. Several immunomodulatory therapies are available, including interferon-β, glatiramer acetate, natalizumab, fingolimod, and mitoxantrone. Although useful to delay disease progression, they do not provide a definitive cure and are associated with some undesirable side-effects. Accordingly, the search for new therapeutic methods constitutes an active investigation field. The use of mesenchymal stem cells (MSCs) to modify the disease course is currently the subject of intense interest. Decidua-derived MSCs (DMSCs) are a cell population obtained from human placental extraembryonic membranes able to differentiate into the three germ layers. This study explores the therapeutic potential of DMSCs.MethodsWe used the experimental autoimmune encephalomyelitis (EAE) animal model to evaluate the effect of DMSCs on clinical signs of the disease and on the presence of inflammatory infiltrates in the central nervous system. We also compared the inflammatory profile of spleen T cells from DMSC-treated mice with that of EAE control animals, and the influence of DMSCs on the in vitro definition of the Th17 phenotype. Furthermore, we analyzed the effects on the presence of some critical cell types in central nervous system infiltrates.ResultsPreventive intraperitoneal injection of DMSCs resulted in a significant delay of external signs of EAE. In addition, treatment of animals already presenting with moderate symptoms resulted in mild EAE with reduced disease scores. Besides decreased inflammatory infiltration, diminished percentages of CD4+IL17+, CD11b+Ly6G+ and CD11b+Ly6C+ cells were found in infiltrates of treated animals. Early immune response was mitigated, with spleen cells of DMSC-treated mice displaying low proliferative response to antigen, decreased production of interleukin (IL)-17, and increased production of the anti-inflammatory cytokines IL-4 and IL-10. Moreover, lower RORγT and higher GATA-3 expression levels were detected in DMSC-treated mice. DMSCs also showed a detrimental influence on the in vitro definition of the Th17 phenotype.ConclusionsDMSCs modulated the clinical course of EAE, modified the frequency and cell composition of the central nervous system infiltrates during the disease, and mediated an impairment of Th17 phenotype establishment in favor of the Th2 subtype. These results suggest that DMSCs might provide a new cell-based therapy for the control of multiple sclerosis.Electronic supplementary materialThe online version of this article (doi:10.1186/s13287-016-0304-5) contains supplementary material, which is available to authorized users.

Background and Purpose PDE4 inhibition suppresses experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis (MS). However, side effects hinder PDE4 inhibitors clinical use. PDE7 inhibition might constitute an alternative therapeutic strategy, but few data about the anti‐inflammatory potential of PDE7 inhibitors are currently available. We have used the EAE model to perform a comparative evaluation of PDE4 and PDE7 inhibition as strategies for MS treatment. Experimental Approach Two PDE7 inhibitors, the sulfonamide derivative BRL50481 and the recently described quinazoline compound TC3.6, were assayed to modulate EAE in SJL mice, in comparison with the well‐known PDE4 inhibitor Rolipram. We evaluated clinical signs, presence of inflammatory infiltrates in CNS and anti‐inflammatory markers. We also analysed the effect of these inhibitors on the inflammatory profile of spleen cells in vitro. Key Results TC3.6 prevented EAE with efficacy similar to Rolipram, while BRL50481 had no effect on the disease. Differences between both PDE7 inhibitors are discussed. Data from Rolipram and TC3.6 showed that PDE4 and PDE7 inhibition work through both common and distinct pathways. Rolipram administration caused an increase in IL‐10 and IL‐27 expression which was not found after TC3.6 treatment. On the other hand, both inhibitors reduced IL‐17 levels, prevented infiltration in CNS and increased the expression of the T regulator cell marker Foxp3. Conclusions and Implications These results provide new information about the effects of Rolipram on EAE, underline PDE7 inhibition as a new therapeutic target for inflammatory diseases and show the value of TC3.6 to prevent EAE, with possible consequences for new therapeutic tools in MS.

Deletion of a region of the promiscuous plasmid pLS1 encompassing the initiation signals for the synthesis of the plasmid lagging strand led to plasmid instability in Streptococcus pneumoniae and Bacillus subtilis. This defect could not be alleviated by increasing the number of copies (measured as double-stranded plasmid DNA) to levels similar to those of the wild-type plasmid pLS1. Our results indicate that in the vicinity of, or associated with the single-stranded origin region of pLS1 there is a plasmid component involved in its stable inheritance. Homology was found between the DNA gyrase binding site within the par region of plasmid pSC101 and the pLS1 specific recombination site RSB.

PDE7 inhibitors regulate pro-inflammatory and immune T-cell functions, and are a potentially novel class of drugs especially useful in the treatment of a wide variety of immune and inflammatory disorders. Starting from our lead family of thioxoquinazolines, we designed, synthesized, and characterized a novel series of thioxoquinazoline derivatives. Many of these compounds showed inhibitory potencies at sub-micromolar levels against the catalytic domain of PDE7A1 and at the micromolar level against PDE4D2. Cell-based studies showed that these compounds not only increased intracellular cAMP levels, but also had interesting anti-inflammatory properties within a therapeutic window. The in silico data predict that these compounds are capable of the crossing the blood-brain barrier. The X-ray crystal structure of the PDE7A1 catalytic domain in complex with compound 15 at a resolution of 2.4 Å demonstrated that hydrophobic interactions at the active site pocket are a key feature. This structure, together with molecular modeling, provides insight into the selectivity of the PDE inhibitors and a template for the discovery of new PDE7 or PDE7/PDE4 dual inhibitors.

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The hybrid plasmid pJS37 is composed of the streptococcal plasmid pLS1, which confers tetracycline resistance, and the staphylococcal plasmid pC194, which confers chloramphenicol resistance. When grampositive bacteria containing pJS37 were grown in the presence of chloramphenicol, four different deleted derivatives accumulated. The deletions in the plasmid enhanced resistance to chloramphenicol by placing the cat gene of pC194 near promoters of pLS1. All four deletions shared a common endpoint that corresponded to the putative target site for DNA strand nicking by the pC194 replication protein, RepH. At the other, variable endpoint, the DNA sequence was similar to the putative RepH target sequence. Alteration of the RepH protein, by in vitro modification of the gene encoding it, eliminated this class of deletions. By extending a previously proposed model for the generation of a different but related class of deletions (B. Michel and S. D. Ehrlich, EMBO J. 5:3691-3696, 1986), a comprehensive model that could generate both classes of deletions is suggested.It proposes that a nicking-closing activity of the plasmid replication protein at its normal target site and, aberrantly, at sites with similar sequence can generate deletions either proximal or distal to the aberrant site during rolling-circle replication of the plasmid.The generation of deletions in recombinant plasmids by intramolecular rearrangement is a common phenomenon. Many of these deletions involve short direct repeats. Although some of them may arise by typical homologous recombination between the direct repeats, which in Escherichia coli requires recA function, others occur in recA mutants apparently as a result of other mechanisms for recombining DNA (1). Two kinds of intramolecular recombination events have been reported. In the first kind, the endpoints of deletions occur within short direct repeats (1,3,11,20); in the second, deletions occur between nonidentical sequences. The latter kind has been observed in Bacillus subtilis (20) In addition to these mechanisms, the plasmid replication machinery may be responsible for generating deletions (11,24). In B. subtilis, a hybrid plasmid composed of pUB110 and pSA2100 (itself composed of pC194 and pSA0501) showed a systematic rec-independent deletion between 18-base-pair (bp) directly repeated sequences (11) located at the plasmid origins of replication (9,21 suggested that a nick introduced in the postulated replication origin of pC194 by the plasmid replication protein served as a deletion endpoint (24). Since accumulation of singlestranded DNA during the replication of pC194 indicates that this plasmid replicates by a rolling-circle mechanism (30), there appears to be a correlation between deletion formation and replication through single-stranded intermediates.We have previously shown that the hybrid plasmid pJS37, composed of plasmids pLS1 and pC194, which carries two origins of replication instead of three as in the examples cited above, undergoes systematic deletions in Streptococcus pneumoniae...