Cloning and characterization of mr-s, a novel SAM domain protein, predominantly expressed in retinal photoreceptor cells

BACKGROUND: Sterile alpha motif (SAM) domains are ~70 residues long and have been reported as common protein-protein interaction modules. This domain is found in a large number of proteins, including Polycomb group (PcG) proteins and ETS family transcription factors. In this work, we report the cloning and functional characterization of a novel SAM domain-containing protein, which is predominantly expressed in retinal photoreceptors and the pineal gland and is designated mouse mr-s (major retinal SAM domain protein). RESULTS: mr-s is evolutionarily conserved from zebrafish through human, organisms through which the mechanism of photoreceptor development is also highly conserved. Phylogenetic analysis suggests that the SAM domain of mr-s is most closely related to a mouse polyhomeotic (ph) ortholog, Mph1/Rae28, which is known as an epigenetic molecule involved in chromatin modifications. These findings provide the possibility that mr-s may play a critical role by regulating gene expression in photoreceptor development. mr-s is preferentially expressed in the photoreceptors at postnatal day 3–6 (P3-6), when photoreceptors undergo terminal differentiation, and in the adult pineal gland. Transcription of mr-s is directly regulated by the cone-rod homeodomain protein Crx. Immunoprecipitation assay showed that the mr-s protein self-associates mainly through the SAM domain-containing region as well as ph. The mr-s protein localizes mainly in the nucleus, when mr-s is overexpressed in HEK293T cells. Moreover, in the luciferase assays, we found that mr-s protein fused to GAL4 DNA-binding domain functions as a transcriptional repressor. We revealed that the repression activity of mr-s is not due to a homophilic interaction through its SAM domain but to the C-terminal region. CONCLUSION: We identified a novel gene, mr-s, which is predominantly expressed in retinal photoreceptors and pineal gland. Based on its expression pattern and biochemical analysis, we predict that mr-s may function as a transcriptional repressor in photoreceptor cells and in pinealocytes of the pineal gland

Chronic Systemic Exposure to Low-Dose Rotenone Induced Central and Peripheral Neuropathology and Motor Deficits in Mice: Reproducible Animal Model of Parkinson's Disease

Epidemiological studies demonstrated that pesticide exposure, such as rotenone and paraquat, increases the risk of Parkinson's disease (PD). Chronic systemic exposure to rotenone, a mitochondrial complex I inhibitor, could reproduce many features of PD. However, the adoption of the models is limiting because of variability in animal sensitivity and the inability of other investigators to consistently reproduce the PD neuropathology. In addition, most of rotenone models were produced in rats. Here, we tried to establish a high-reproducible rotenone model using C57BL/6J mice. The rotenone mouse model was produced by chronic systemic exposure to a low dose of rotenone (2.5 mg/kg/day) for 4 weeks by subcutaneous implantation of rotenone-filled osmotic mini pump. The rotenone-treated mice exhibited motor deficits assessed by open field, rotarod and cylinder test and gastrointestinal dysfunction. Rotenone treatment decreased the number of dopaminergic neuronal cells in the substantia nigra pars compacta (SNpc) and lesioned nerve terminal in the striatum. In addition, we observed significant reduction of cholinergic neurons in the dorsal motor nucleus of the vagus (DMV) and the intestinal myenteric plexus. Moreover, alpha-synuclein was accumulated in neuronal soma in the SNpc, DMV and intestinal myenteric plexus in rotenone-treated mice. These data suggest that the low-dose rotenone mouse model could reproduce behavioral and central and peripheral neurodegenerative features of PD and be a useful model for investigation of PD pathogenesis

Gene expression profile and pathogenicity of biofilm-forming Prevotella intermedia strain 17

<p>Abstract</p> <p>Background</p> <p><it>Prevotella intermedia </it>(<it>P. intermedia</it>), a gram-negative, black-pigmented anaerobic rod, has been implicated in the development of chronic oral infection. <it>P. intermedia </it>strain 17 was isolated from a chronic periodontitis lesion in our laboratory and described as a viscous material producing strain. The stock cultures of this strain still maintain the ability to produce large amounts of viscous materials in the spent culture media and form biofilm-like structures. Chemical analyses of this viscous material showed that they were mainly composed of neutral sugars with mannose constituting 83% of the polysaccharides. To examine the biological effect of the extracellular viscous materials, we identified and obtained a naturally-occurring variant strain that lacked the ability to produce viscous materials <it>in vitro </it>from our stock culture collections of strain 17, designated as 17-2. We compared these two strains (strains 17 versus 17-2) in terms of their capacities to form biofilms and to induce abscess formation in mice as an indication of their pathogenicity. Further, gene expression profiles between these two strains in planktonic condition and gene expression patterns of strain 17 in solid and liquid cultures were also compared using microarray assays.</p> <p>Results</p> <p>Strain 17 induced greater abscess formation in mice as compared to that of the variant. Strain 17, but not 17-2 showed an ability to interfere with the phagocytic activity of human neutrophils. Expression of several genes which including those for heat shock proteins (DnaJ, DnaK, ClpB, GroEL and GroES) were up-regulated two to four-fold with statistical significance in biofilm-forming strain 17 as compared to the variant strain 17-2. Strain 17 in solid culture condition exhibited more than eight-fold up-regulated expression levels of several genes which including those for levanase, extracytoplasmic function-subfamily sigma factor (σ^E; putative) and polysialic acid transport protein (KpsD), as compared to those of strain 17 in liquid culture media.</p> <p>Conclusion</p> <p>These results demonstrate that the capacity to form biofilm in <it>P. intermedia </it>contribute to their resistance against host innate defence responses.</p

婦人農作業衣に関する研究(第5報) : 動作時の着ごこちに影響を及ぼす部位の検討

"以上動作時の着心地に彩管を及ぼす部位と袖構成との関係を検討し,次の結果を得た.1.着心地に影響を及ぼす部位である腋下部の動体計測値の中で,正常立位姿勢時と比較して最大伸長差がみとめられたのは, 180°上肢上挙時の胴囲線脇点より腋窩中点を通る手首点までの,(ニ)の計測値で伸長差15.5cm, 25%の伸長率であり,110°前屈時(ホ)の計測伸長差は13.7cm, 22%の伸長率がみとめられた. 2. 180°上肢上挙時における袖機能順位は,a型が最も機能性がよく,次にb, d, cの順位にみられたが,人体と袖の構成との関係要因についてみると,a型袖は腋下部の作業衣計測値と180°上挙時の,人体計測値との寸法差,すなわち皮膚面と衣服とのずれ寸法差が,4作業衣中最小差である.又袖構造上では,腋下から袖下ヘタテ布10cm幅のマチ布がひと続きに真直ぐに縫合され,腋窩に伸長規制の縫目がないことと,上挙時の機能障害要因である袖山寸法が,最小寸法で構成されている.又上挙時腋下の伸長に対する不足寸法は,袖口がゴム形式構成のため,袖口下りの対応が容易に可能であり,被服人間工学上,よく配慮されている点などが,機能性につながる最適要因であると考えられる.その他の袖型においては,上挙時の規制要因である袖下腋下の寸法差及び袖山寸法は,b,c,dの順位に大の傾向がみられた.中でもc型袖は袖口形態が,カフス式構成のため,上挙時腋下の伸長に対する不足寸法の対応が困難で,作業衣としてはこの点が,最大不適合であると考えられた. 3. 110°前屈身姿勢における袖機能順位は,b型が最もよく,次にa, c, dの順位にみられた.人体に適合する被服は,腋下部の伸長と同時に背面の伸びにも適応出来うるゆとり量が加味された構成でなければ,適合は満足出来ない.したがって,人体を包んでいる袖部と身頃部との有機的相互作用により,機能が発揮される.上記の観点から,この部位の人体と作業衣の計測伸長さの最小寸法であるb型普通袖が,着心地が最も良く,次にa, c, dの順に寸法差の大の傾向が見られた.又構造上では,b型は背面ヨークが前報で述べた通り,人体適合位線で設定され,機能量も最適寸法で構成されているためで,a型は前屈時には,後背部襠角の縫合部に力がかかり,縫目が破断しやすい状態となる欠点がみとめられた.又c型ラグラン袖は,背部に切替線がなく,袖口がカフス形式になっているために,上肢の動きに伴なう袖丈の調節が容易に出来ず,機能が劣る.次にきもの式袖d型は,どの体型にも合うが,上肢上挙,前屈身動作には,袖付寸法が長く身八つ口開口部がないため,袖付止まりの位置に力がかかり,動作が規制されて不適である.以上,袖の構成形式の異なる代表的既製作業衣4種につき比較検討したが,作業衣購入の場合には,胸囲寸法,背幅のゆとり量,袖の構成形式,デザイン,素材等をよく吟味し,寸法的に大は小をかねる式の考えではなく,動的機能にかなった適切なゆとり量の考慮されたものを,選択購入すべきであると考える.終わりに本研究に被験者として御協力下さった,本学家政科被服コースの学生に感謝の意を表します.

Transmission of survival signals through Delta-like 1 on activated CD4+ T cells

Notch expressed on CD4+ T cells transduces signals that mediate their effector functions and survival. Although Notch signaling is known to be cis-inhibited by Notch ligands expressed on the same cells, the role of Notch ligands on T cells remains unclear. In this report we demonstrate that the CD4+ T cell Notch ligand Dll1 transduces signals required for their survival. Co-transfer of CD4+ T cells from Dll1−/− and control mice into recipient mice followed by immunization revealed a rapid decline of CD4+ T cells from Dll1−/− mice compared with control cells. Dll1−/− mice exhibited lower clinical scores of experimental autoimmune encephalitis than control mice. The expression of Notch target genes in CD4+ T cells from Dll1−/− mice was not affected, suggesting that Dll1 deficiency in T cells does not affect cis Notch signaling. Overexpression of the intracellular domain of Dll1 in Dll1-deficient CD4+ T cells partially rescued impaired survival. Our data demonstrate that Dll1 is an independent regulator of Notch-signaling important for the survival of activated CD4+ T cells, and provide new insight into the physiological roles of Notch ligands as well as a regulatory mechanism important for maintaining adaptive immune responses

Comparison of the virulence of exopolysaccharide-producing Prevotella intermedia to exopolysaccharide non-producing periodontopathic organisms

<p>Abstract</p> <p>Background</p> <p>Evidence in the literature suggests that exopolysaccharides (EPS) produced by bacterial cells are essential for the expression of virulence in these organisms. Secreted EPSs form the framework in which microbial biofilms are built.</p> <p>Methods</p> <p>This study evaluates the role of EPS in <it>Prevotella intermedia </it>for the expression of virulence. This evaluation was accomplished by comparing EPS-producing <it>P. intermedia </it>strains 17 and OD1-16 with non-producing <it>P. intermedia </it>ATCC 25611 and <it>Porphyromonas gingivalis </it>strains ATCC 33277, 381 and W83 for their ability to induce abscess formation in mice and evade phagocytosis.</p> <p>Results</p> <p>EPS-producing <it>P. intermedia </it>strains 17 and OD1-16 induced highly noticeable abscess lesions in mice at 10⁷colony-forming units (CFU). In comparison, <it>P. intermedia </it>ATCC 25611 and <it>P. gingivalis </it>ATCC 33277, 381 and W83, which all lacked the ability to produce viscous materials, required 100-fold more bacteria (10⁹CFU) in order to induce detectable abscess lesions in mice. Regarding antiphagocytic activity, <it>P. intermedia </it>strains 17 and OD1-16 were rarely internalized by human polymorphonuclear leukocytes, but other strains were readily engulfed and detected in the phagosomes of these phagocytes.</p> <p>Conclusions</p> <p>These results demonstrate that the production of EPS by <it>P. intermedia </it>strains 17 and OD1-16 could contribute to the pathogenicity of this organism by conferring their ability to evade the host's innate defence response.</p