Involvement of Propionibacterium acnes in the Augmentation of Lipogenesis in Hamster Sebaceous Glands In Vivo and In Vitro

Propionibacterium acnes is considered to be involved in the aggravation of acne vulgaris, but it remains unclear whether P. acnes directly influences lipogenesis in sebaceous glands. In this study, we showed that a culture medium of P. acnes (acnes-CM) and formalin-killed P. acnes (F-acnes) prepared from P. acnes strains, JCM6473 and JCM6425, intracellularly augmented lipid droplet formation and triacylglycerol (TG) synthesis in undifferentiated and insulin-differentiated hamster sebocytes. Acnes-CM and F-acnes prepared from four clinical P. acnes strains elicited the same lipogenesis augmentation. The augmented TG production resulted from an increase in the diacylglycerol acyltransferase activity. Topical application of acnes-CM to the skin of hamster auricles every day for 4 weeks revealed that sebum accumulation was augmented in sebaceous glands and ducts. Furthermore, both acnes-CM and F-acnes increased the production of 15-deoxy-Δ12,14-prostaglandin J2 (15d-PGJ2), a cytochrome P450 (CYP)-linked sebaceous lipogenic factor, in differentiated sebocytes. A CYP inhibitor, SKF-525A, decreased the acnes-CM- and F-acnes-augmented production of TG and 15d-PGJ2. Thus, to our knowledge these results provide previously unreported evidence that P. acnes directly participates in the augmentation of sebaceous lipogenesis through a proposed mechanism in which an increase of 15d-PGJ2 production through the CYP pathway is closely associated with the enhancement of TG production

SGLT2阻害薬であるイプラグリフロジンは2型糖尿病自然発症モデルであるOLETFラットにおいて肝線維化進展を抑制する。

BACKGROUND: It is widely understood that insulin resistance (IR) critically correlates with the development of liver fibrosis in several types of chronic liver injuries. Several experiments have proved that anti-IR treatment can alleviate liver fibrosis. Sodium-glucose cotransporter 2 (SGLT2) inhibitors comprise a new class of antidiabetic agents that inhibit glucose reabsorption in the renal proximal tubules, improving IR. The aim of this study was to elucidate the effect of an SGLT2 inhibitor on the development of liver fibrosis using obese diabetic Otsuka Long-Evans Tokushima fatty (OLETF) rats and their littermate nondiabetic Long-Evans Tokushima Otsuka (LETO) rats. METHODS: Male OLETF and LETO rats were intraperitoneally injected with porcine serum twice a week for 12 weeks to augment liver fibrogenesis. Different concentrations of ipragliflozin (3 and 6 mg/kg) were orally administered during the experimental period. Serological and histological data were examined at the end of the experimental period. The direct effect of ipragliflozin on the proliferation of a human hepatic stellate cell (HSC) line, LX-2, was also evaluated in vitro. RESULTS: OLETF rats, but not LETO rats, received 12 weeks of porcine serum injection to induce severe fibrosis. Treatment with ipragliflozin markedly attenuated the development of liver fibrosis and expression of hepatic fibrosis markers, such as alpha smooth muscle actin, collagen 1A1, and transforming growth factor beta (TGF-β), and improved IR in a dose-dependent manner in OLETF rats. In contrast, the proliferation of LX-2 in vitro was not affected, suggesting that ipragliflozin had no significant direct effect on the proliferation of HSCs. CONCLUSION: In conclusion, our dataset suggests that an SGLT2 inhibitor could alleviate the development of liver fibrosis by improving IR in naturally diabetic rats. This may provide the basis for creating new therapeutic strategies for chronic liver injuries with IR.博士（医学）・甲第665号・平成29年3月15日© Japanese Society of Gastroenterology 2016The final publication is available at Springer via http://dx.doi.org/10.1007/s00535-016-1200-6

非アルコール性脂肪肝炎（NASH）モデルのラットにおいて、エンドトキシンの減少が肝星細胞の活性化抑制と腸管透過性改善を介して肝線維化進展を抑制する。

Previous clinical studies have demonstrated that endotoxin/toll‑like receptor 4 (TLR4) signaling is critical in the inflammatory pathways associated with non‑alcoholic steatohepatitis (NASH). In human and animal studies, NASH was associated with portal lipopolysaccharide (LPS) and the plasma LPS level was hypothesized to be associated with small intestinal bacterial overgrowth, change in composition of the microbiota and increased intestinal permeability. The aim of the present study was to investigate the roles of endogenous endotoxin and TLR4 in the pathogenesis of NASH. The effects of antibiotics were assessed in vivo using a choline deficiency amino acid (CDAA)‑induced experimental liver fibrosis model. Antibiotics, including polymyxins and neomycins, were orally administered in drinking water. Antibiotics attenuated hepatic stellate cell (HSC) activation and liver fibrosis via TGF‑β and collagen in an experimental hepatic fibrosis model. The mechanism by which antibiotics attenuated LPS‑TLR4 signaling and liver fibrosis was assessed. Notably, TLR4 mRNA level in the liver was elevated in the CDAA group and the CDAA‑induced increase was significantly reduced by antibiotics. However, no significant differences were observed in the intestine among all groups. Elevated mRNA levels of LPS binding protein, which was correlated with serum endotoxin levels, were recognized in the CDAA group and the CDAA‑induced increase was significantly reduced by antibiotics. The intestinal permeability of the CDAA group was increased compared with the choline‑supplemented amino acid group. The tight junction protein (TJP) in the intestine, determined by immunohistochemical analysis was inversely associated with intestinal permeability. Antibiotics improved the intestinal permeability and enhanced TJP expression. Inhibition of LPS‑TLR4 signaling with antibiotics attenuated liver fibrosis development associated with NASH via the inhibition of HSC activation. These results indicated that reduction of LPS and restoration of intestinal TJP may be a novel therapeutic strategy for treatment of liver fibrosis development in NASH.博士（医学）・甲第628号・平成27年3月16日Copyright: © Douhara et al. This is an open access article distributed under the terms of a Creative Commons Attribution License.The definitive version is available at " http://dx.doi.org/10.3892/mmr.2014.2995

肝線維化におけるペリオスチンの役割 : レニン・アンギオテンシン系とクロストーク

Periostin is a 90‑kDa extracellular matrix protein, which is secreted primarily from fibroblasts and is expressed in the lungs, kidneys and heart valves. Angiotensin II (AT‑II) serves pivotal roles in the pathogenesis of several diseases with accompanying fibrosis, including chronic liver diseases. AT‑II induces periostin expression by regulating transforming growth factor‑β1 (TGF‑β1)/Smad signaling during cardiac fibrosis. The aim of the present study was to investigate the interaction between AT‑II and periostin during liver fibrosis development. Fischer 344 rats were fed a choline‑deficient L‑amino‑acid (CDAA)‑defined diet for 12 weeks to simulate the development of steatohepatitis with liver fibrosis. Losartan, an AT‑II type I receptor blocker, was administered to inhibit the effect of AT‑II. The therapeutic effect of losartan on hepatic fibrosis development and on periostin expression was then evaluated. Several in vitro experiments were performed to examine the mechanisms underlying the interaction between AT‑II and periostin in activated hepatic stellate cells (Ac‑HSCs). Treatment with losartan suppressed the development of liver fibrosis induced by the CDAA diet, and reduced hepatic periostin expression. In addition, losartan treatment suppressed hepatic Ac‑HSC expansion and hepatic TGF‑β1 expression. In vitro analysis using LX2 HSC cells indicated that AT‑II can augment TGF‑β1 and collagen type I α1 mRNA expression via periostin expression, suggesting that the interaction between AT‑II and periostin may serve a role in liver fibrosis development. In conclusion, blockade of AT‑II‑induced periostin may suppress the progression of liver fibrosis development.博士（医学）・乙第1413号・平成30年3月15日Copyright: © Takeda et al. This is an open access article distributed under the terms of Creative Commons Attribution License(CC BY-NC-ND 4.0) https://creativecommons.org/licenses/by-nc-nd/4.0/

Abnormal spermatogenesis and male infertility in testicular zinc finger protein Zfp318-knockout mice

Zfp318, a mouse gene with a Cys2/His2 zinc finger motif, is mainly expressed in germ cells in the testis. It encodes two alternative transcripts, which regulate androgen receptor-mediated transcriptional activation or repression by overexpression of them. However, the role of Zfp318 is still obscure in vivo, especially in spermatogenesis. To elucidate the role of Zfp318 during gamete production, we established a knockout mouse line. Zfp318-null male mice exhibited infertility, whereas Zfp318-null female mice displayed normal fertility. ZFP318 was expressed during multiple stages of spermatogenesis, from spermatocytes to round spermatids. The nuclei of secondary spermatocytes showed high levels of expression. Histological analysis and quantitative analysis of DNA content showed decreased numbers of both spermatids in the seminiferous tubules and mature spermatozoa in the epididymides of Zfp318-null mice. These results suggest that Zfp318 is expressed as a functional protein in testicular germ cells and plays an important role in meiosis during spermatogenesis

Evidence of plasmonic effects in random orientation silver nanowire meshes on silicon

In this work silver nanowires were used as the transparent conductive electrode on a crystalline silicon solar cell in place of the commonly used screen printed grid. Light transmission and surface characterisation of the cells displays an average of 22% more light transmission than the physical non-AgNW shaded area of the cell surface. Further to this it is observed that plasmonic effects result in an increased scattering of incoming light into the cell, which also reduced the amount of light reflected from the cell’s front plane. The cells with silver nanowire electrodes did not, however, show improved current–voltage characteristics compared to cells without a front electrode. This is attributed to the overall low light transmission as a result of silver nanoparticles present in the electrodes and poor electrical connection between silicon cell and electrode. Finally, a large reduction in the mass of silver used for the nanowire electrodes was observed when compared to standard screen printed grid fingers

理科指導法において「授業UD」に基づく授業改善の試み

本研究の目的は，理科指導法での授業分析において，授業UD を取り入れ，理科の授業力量に関する学びの実態や課題について検討を行い，効果的な指導法を探ることである。学生のアンケートと振り返りの分析を行なった結果，次のことが分かった。（1）模擬授業を実践すること以上に，模擬授業を分析することによる学びが大きい。模擬授業の分析に授業UD の視点を取り入れることによって，授業分析の視点を手にするとともに，授業UD が授業を省察する足場となっている。（2）「視覚化」「焦点化」「共有化」等を取り入れることによって，「付箋紙による授業評価」「ミニホワイトボードによる討論」「ホワイトボードによる整理」等，授業分析・検討をより深める支援を実現できた。授業UD の視点を授業に取り入れることによって，教師が授業改善を行う手立てとなることが明らかとなった。教師の力量形成における授業UD の意味は大変大きいと考える

Fluoroquinolone Efflux by the Plasmid-Mediated Multidrug Efflux Pump QacB Variant QacBIII in Staphylococcus aureus▿

Plasmids that carry the multidrug efflux genes qacA and qacB are widely distributed in methicillin-resistant Staphylococcus aureus (MRSA). Although the QacA and QacB proteins are similar to each other, their respective substrate specificities may differ. We investigated the variability and structure-function relationships of QacA and QacB in MRSA isolates. The amino acid sequences of 7 QacA and 25 QacB proteins showed that QacB was present in three variants, designated QacBII, QacBIII, and QacBIV, that were different from the prototypic QacB variant encoded by plasmid pSK23, which was named QacBI, while QacA was present in two variants. When cloned and expressed in S. aureus, the strain carrying qacBIII exhibited higher susceptibility to dyes and decreased susceptibility to norfloxacin and ciprofloxacin compared to strains carrying the other QacB variants. Site-directed mutagenesis experiments revealed that the residue at position 320 in QacB plays an important role in the resistance phenotypes to dyes and fluoroquinolones. Furthermore, the accumulation of norfloxacin and ciprofloxacin in the strain carrying qacBIII was significantly decreased. Our data demonstrate that the plasmid-mediated multidrug efflux pump QacB variant QacBIII confers the capability for fluoroquinolone efflux on S. aureus