Dopamine D1-like receptor antagonist attenuates Th17-mediated immune response and ovalbumin antigen-induced neutrophilic airway inflammation

Allergic airway inflammation is generally considered a Th2-type immune response. Recent studies, however, demonstrated that Th17-type immune responses also play important roles in this process, especially in the pathogenesis of neutrophilic airway inflammation, a hallmark of severe asthma. We previously reported that dendritic cells release dopamine to naive CD4(+) T cells in Ag-specific cell-cell interaction, in turn inducing Th17 differentiation through dopamine D1-like receptor (D1-like-R). D1-like-R antagonist attenuates Th17-mediated diseases such as experimental autoimmune encephalomyelitis and autoimmune diabetes. However, the effect of antagonizing D1-like-R on Th17-mediated airway inflammation has yet to be studied. In this study, we examined whether D1-like-R antagonist suppresses OVA-induced neutrophilic airway inflammation in OVA TCR-transgenic DO11.10 mice and then elucidated the mechanism of action. DO11.10 mice were nebulized with OVA or PBS, and some mice received D1-like-R antagonist orally before OVA nebulization. D1-like-R antagonist significantly suppressed OVA-induced neutrophilic airway inflammation in DO11.10 mice. It also inhibited the production of IL-17 and infiltration of Th17 cells in the lung. Further, D1-like-R antagonist suppressed the production of IL-23 by lung CD11c(+) APCs. In contrast, D1-like-R antagonist did not increase Foxp3(+) regulatory T cells in the lung. D1-like-R antagonist neither suppressed nonspecific LPS-induced neutrophilic airway inflammation nor OVA-induced eosinophilic airway inflammation. These results indicate that D1-like-R antagonist could suppress Th17-mediated neutrophilic airway inflammation, raising the possibility that antagonizing D1-like-R serves as a promising new strategy for treating neutrophil-dominant severe asthma.     

Effect of age and number of parturitions on uterine and ovarian variables in owl monkeys

Background We aimed to evaluate the uterine and ovarian volumes of owl monkeys in different age groups with different numbers of live births and to analyze the interaction between both. Methods We performed pelvic ultrasound exams to compare the uterine measurements with weight, age (infant, juvenile, subadult, young adults, and adults) and the number of live births (nulliparous, primiparous, and multiparous) and to compare the ovarian measurements with weight and age. Results and Conclusions The uterine volume (UV) was directly proportional to the number of parturitions, which was the most important factor in the uterine growth of adult females (P < 0.05). The body weight and age of the animals showed a high positive correlation with UV (r = 0.5354, r = 0.6489, P < 0.01), respectively. The volume of the ovaries grew in proportion to the age of the females (P < 0.05). Puberty was the period of greatest uterine and ovarian growth.     

The CKH2/PKL chromatin remodeling factor negatively regulates cytokinin responses in Arabidopsis calli

Cytokinins promote cell division and chloroplast development in tissue culture. We previously isolated two mutants of Arabidopsis thaliana, ckh1 (cytokinin-hypersensitive 1) and ckh2, which produce rapidly growing green calli in response to lower levels of cytokinins than those found in the wild type. Here we report that the product of the CKH2 gene is PICKLE, a protein resembling the CHD3 class of SWI/SNF chromatin remodeling factors. We also show that inhibition of histone deacetylase by trichostatin A (TSA) partially substituted for cytokinins, but not for auxin, in the promotion of callus growth, indicating that chromatin remodeling and histone deacetylation are intimately related to cytokinin-induced callus growth. A microarray experiment revealed that either the ckh1 mutation or the ckh2 mutation caused hypersensitivity to cytokinins in terms of gene expression, especially of photosynthesis-related genes. The ckh1 and ckh2 mutations up-regulated nuclear-encoded genes, but not plastid-encoded genes, whereas TSA deregulated both nuclear- and plastid-encoded genes. The ckh1 ckh2 double mutant showed synergistic phenotypes: the callus grew with a green color independently of exogenous cytokinins. A yeast two-hybrid experiment showed protein interaction between CKH1/EER4/AtTAF12b and CKH2/PKL. These results suggest that CKH1/EER4/AtTAF12b and CKH2/PKL may act together on cytokinin-regulated genes.     

12-hydroxyjasmonic acid glucoside is a COI1-JAZ-independent activator of leaf-closing movement in Samanea saman

Jasmonates are ubiquitously occurring plant growth regulators with high structural diversity that mediate numerous developmental processes and stress responses. We have recently identified 12-O-β-D-glucopyranosyljasmonic acid as the bioactive metabolite, leaf-closing factor (LCF), which induced nyctinastic leaf closure of Samanea saman. We demonstrate that leaf closure of isolated Samanea pinnae is induced upon stereospecific recognition of (-)-LCF, but not by its enantiomer, (+)-ent-LCF, and that the nonglucosylated derivative, (-)-12-hydroxyjasmonic acid also displays weak activity. Similarly, rapid and cell type-specific shrinkage of extensor motor cell protoplasts was selectively initiated upon treatment with (-)-LCF, whereas flexor motor cell protoplasts did not respond. In these bioassays related to leaf movement, all other jasmonates tested were inactive, including jasmonic acid (JA) and the potent derivates JA-isoleucine and coronatine. By contrast, (-)-LCF and (-)-12-hydroxyjasmonic acid were completely inactive with respect to activation of typical JA responses, such as induction of JA-responsive genes LOX2 and OPCL1 in Arabidopsis (Arabidopsis thaliana) or accumulation of plant volatile organic compounds in S. saman and lima bean (Phaseolus lunatus), generally considered to be mediated by JA-isoleucine in a COI1-dependent fashion. Furthermore, application of selective inhibitors indicated that leaf movement in S. saman is mediated by rapid potassium fluxes initiated by opening of potassium-permeable channels. Collectively, our data point to the existence of at least two separate JA signaling pathways in S. saman and that 12-O-β-D-glucopyranosyljasmonic acid exerts its leaf-closing activity through a mechanism independent of the COI1-JAZ module.     

In vitro multipotentiality and characterization of human unfractured traumatic hemarthrosis-derived progenitor cells: A potential cell source for tissue repair

Mesenchymal progenitor cells (MPCs) are a very attractive tool in the context of repair and regeneration of musculoskeletal tissue damaged by trauma. The most common source of MPCs to date has been the bone marrow, but aspirating bone marrow from the patient is an invasive procedure. In an attempt to search for alternative sources of MPCs that could be obtained with minimal invasion, we looked into traumatic hemarthrosis of the knee. In this study, we determined whether a population of multipotent MPCs could be isolated from acute traumatic knee hemarthrosis in the absence of intra-articular fractures. Mononuclear cells were isolated from the aspirated hemarthrosis by density gradient separation, and cultured. We were able to obtain plastic adherent fibroblast-like cells from the mononuclear cell fractions. Flow cytometry analysis revealed that the adherent fibroblast-like cells were consistently positive for CD29, CD44, CD105, and CD166, and were negative for CD14, CD34, and CD45. These were similar to control bone marrow stromal cells. These cells could differentiate in vitro into osteogenic, adipogenic, and chondrogenic cells in the presence of lineage-specific induction factors. In conclusion, acute unfractured traumatic hemarthrosis of the knee contains MPCs with multipotentiality. Because knee hemarthrosis is easy to harvest with minimal pain and without unnecessary invasion, we regard hemarthrosis-derived cells as an additional progenitor cell source for future tissue engineering and cell-based therapy in knee injuries.     

Lack of chromatin and nuclear fragmentation in vivo impairs the production of lupus anti-nuclear antibodies

Nuclear autoantigens in systemic lupus erythematosus are thought to derive primarily from apoptotic cells, yet there is no direct evidence that interfering with apoptosis impairs the generation of lupus autoantibodies. Here we use a mouse model that lacks the endonuclease caspase-activated DNase (CAD), resulting in an absence of chromatin and nuclear fragmentation during apoptotic cell death. We show that in this mouse, production and release into circulation of chromatin is impaired after exposure to several apoptotic triggers, but that the absence of CAD does not interfere with upstream steps of apoptosis or immune system function. Finally we show that in CAD-mutant mice, impaired lupus autoimmunity is skewed toward known cytoplasmic components, and autoimmunity toward membrane autoantigens is preserved, while autoimmunity toward chromatin and other lupus nuclear targets is severely impaired or absent. We also show, as control, that the induction of experimental autoimmune encephalomyelitis is not affected by the absence of CAD. Thus, our work in vivo strongly suggests that apoptotic molecular steps during cell death generate nuclear autoantigens to sustain the specific autoimmune response in systemic lupus erythematosus.     

Comprehensive analysis of distinctive polyketide and nonribosomal peptide structural motifs encoded in microbial genomes

We developed a highly accurate method to predict polyketide (PK) and nonribosomal peptide (NRP) structures encoded in microbial genomes. PKs/NRPs are polymers of carbonyl/peptidyl chains synthesized by polyketide synthases (PKS) and nonribosomal peptide synthetases (NRPS). We analyzed domain sequences corresponding to specific substrates and physical interactions between PKSs/NRPSs in order to predict which substrates (carbonyl/peptidyl units) are selected and assembled into highly ordered chemical structures. The predicted PKs/NRPs were represented as the sequences of carbonyl/peptidyl units to extract the structural motifs efficiently. We applied our method to 4529 PKSs/NRPSs and found 619 PKs/NRPs. We also collected 1449 PKs/NRPs whose chemical structures have been determined experimentally. The structural sequences were compared using the Smith-Waterman algorithm, and clustered into 271 clusters. From the compound clusters, we extracted 33 structural motifs that are significantly related with their bioactivities. We used the structural motifs to infer functions of 13 novel PKs/NRPs clusters produced by Pseudomonas spp. and Burkholderia spp. and found a putative virulence factor. The integrative analysis of genomic and chemical information given here will provide a strategy to predict the chemical structures, the biosynthetic pathways, and the biological activities of PKs/NRPs, which is useful for the rational design of novel PKs/NRPs.