Intravitreal injection of corticosteroid attenuates leukostasis and vascular leakage

PURPOSE. Recently, intravitreal injection of corticosteroids has been in wide use as a treatment for diabetic macular edema, and the outcomes have been favorable. However, the exact mechanism remains unclear. The hypothesis for the current study was that intravitreal corticosteroids may improve diabetic retinal edema by amelioration of blood-retinal barrier (BRB) breakdown, by inhibiting leukocyte stasis (leukostasis). METHODS. Diabetes was induced in 6-week-old male Long-Evans rats by intraperitoneal injection of streptozotocin (75 mg/kg). Three weeks after induction of diabetes, intravitreal injection of dexamethasone (40 g/10 L) was performed. At 2 days after intravitreal injection, accumulated leukocytes were counted in vivo by acridine orange leukocyte fluorography, and BRB breakdown was evaluated by measurement of retinal vascular permeability. The mRNA expression and protein levels of intercellular adhesion molecule (ICAM)-1 in the retina were also studied. RESULTS. The number of leukocytes accumulated in the retina, once increased in the diabetic group, was decreased by 31.6% (P ϭ 0.0001) after dexamethasone injection. The level of BRB breakdown, also elevated in the diabetic group, was suppressed by 61.1% (P ϭ 0.0046) after dexamethasone injection. The level of ICAM-1 mRNA expression and its protein, upregulated in the diabetic group, were downregulated by dexamethasone treatment by 70.0% (P Ͻ 0.0001) and 56.4% (P ϭ 0.0003). CONCLUSIONS. Intravitreal injection of corticosteroids improves diabetic retinal edema through inhibiting leukocyte recruitment in the diabetic retina. (Invest Ophthalmol Vis Sci. 2005

Strain-induced creation and switching of anion vacancy layers in perovskite oxynitrides

Using strain to control oxynitride properties. 京都大学プレスリリース. 2020-12-01.原子空孔の配列を制御する新手法の発見. 京都大学プレスリリース. 2020-12-02.Perovskite oxides can host various anion-vacancy orders, which greatly change their properties, but the order pattern is still difficult to manipulate. Separately, lattice strain between thin film oxides and a substrate induces improved functions and novel states of matter, while little attention has been paid to changes in chemical composition. Here we combine these two aspects to achieve strain-induced creation and switching of anion-vacancy patterns in perovskite films. Epitaxial SrVO3 films are topochemically converted to anion-deficient oxynitrides by ammonia treatment, where the direction or periodicity of defect planes is altered depending on the substrate employed, unlike the known change in crystal orientation. First-principles calculations verified its biaxial strain effect. Like oxide heterostructures, the oxynitride has a superlattice of insulating and metallic blocks. Given the abundance of perovskite families, this study provides new opportunities to design superlattices by chemically modifying simple perovskite oxides with tunable anion-vacancy patterns through epitaxial lattice strain

コウケツアツ ラット ニ オケル イッカセイ キョケツゴ モウマク ショウガイ ノ セイタイナイ ヒョウカ

京都大学0048新制・課程博士博士(医学)甲第12228号医博第2981号新制||医||923(附属図書館)24064UT51-2006-J221京都大学大学院医学研究科外科系専攻(主査)教授 真鍋 俊明, 教授 芹川 忠夫, 教授 鈴木 茂彦学位規則第4条第1項該当Doctor of Medical ScienceKyoto UniversityDA

The HIRA complex subunit Hip3 plays important roles in the silencing of meiosis-specific genes in Schizosaccharomyces pombe.

BACKGROUND: The control of gene expression is essential for growth and responses to environmental changes in various organisms. It is known that some meiosis-specific genes are silenced during mitosis and expressed upon nitrogen starvation in Schizosaccharomyces pombe. When the factors responsible for this regulation were studied, a hip3 mutant was isolated via discovery of a defect in the transcriptional repression of meiosis-specific genes. Hip3 is a subunit of the HIRA (histone regulatory complex A) complex, which consists of four subunits (Hip1, Hip3, Hip4 and Slm9) and acts as a histone chaperone that is independent of DNA replication. METHODOLOGY/PRINCIPAL FINDINGS: In a search for mutants, the meiosis-specific gene SPCC663.14c(+) was identified by screening for genes that are silenced during mitosis and induced upon nitrogen starvation. A reporter plasmid that expresses the ura4(+) gene driven by the SPCC663.14c(+) promoter was constructed. Screening for suppressor mutants was then carried out in nitrogen-rich medium without uracil. A mutant with a mutation in the hip3(+) gene was isolated and named hip3-1. This mutation alleviated the transcriptional repression of the ura4(+) gene on the reporter plasmid and of the endogenous SPCC663.14c(+) gene in the presence of nitrogen. A ChIP assay revealed that RNA polymerase II (Pol II) and TFIIE were enriched at the SPCC663.14c(+) locus, whereas the levels of histone H3 were decreased in hip3-1 cells. Intriguingly, histone H3 was heavily modified at the SPCC663.14c(+) locus in hip3-1 cells; these modifications included tri-methylation and acetylation of H3 lysine 9 (H3K9), mono-methylation of H3 arginine 2 (H3R2), and tri-methylation of H3 lysine 4 (H3K4). In addition, the tri-methylation of H3K9 and H3K4 were strongly elevated in hip3-1 mutants. CONCLUSIONS: Taken together, these results indicate that Hip3 plays important roles in the control of histone modifications at meiosis-specific gene loci and induces their transcriptional repression