温度応答型生分解性スマートバイオマテリアルのゲル化機序の解明と薬物放出デバイスとしての利用に関する研究

関西大

Studies on clarification of gelation mechanism of temperature-responsive biodegradable smart biomaterials and their utility as drug releasing devices [論文要旨及び審査の要旨]

関西大

A rarefied gas flow around a rotating sphere: diverging profiles of gradients of macroscopic quantities

The steady behaviour of a rarefied gas around a rotating sphere is studied numerically on the basis of the linearised ellipsoidal statistical model of the Boltzmann equation, also known as the ES model, and the Maxwell diffuse–specular boundary condition. It is demonstrated numerically that the normal derivative of the circumferential component of the flow velocity and that of the heat flux diverge on the boundary with a rate s⁻¹/² , where s is the normal distance from the boundary. Further, it is demonstrated that the diverging term is proportional to the magnitude of the jump discontinuity of the velocity distribution function on the boundary, which originates from the mismatch of the incoming and outgoing data on the boundary. The moment of force exerted on the sphere is also obtained for a wide range of the Knudsen number and for various values of the accommodation coefficient

Subcellular dynamics of red clover necrotic mosaic virus double-stranded RNAs in infected plant cells

New evidences are emerging to support the importance of viral replication complexes (VRCs) in not only viral replication, but also viral cell-to-cell movement. Currently, how VRCs grow in size and colocalize with viral movement proteins (MPs) remains unclear. Herein, we performed live-cell imaging of red clover necrotic mosaic virus (RCNMV) dsRNA by using reporter B2-GFP plants. Tiny granules of dsRNA were formed along the endoplasmic reticulum (ER) at an early stage of infection. Importantly, the colocalization of the dsRNA granules with the virus-encoded p27 replication protein showed that these structures are components of VRCs. These granules moved throughout the cytoplasm, driven by the acto–myosin system, and coalesced with each other to form larger aggregates; the MPs were not associated with these processes. Notably, the MPs colocalized preferentially with large dsRNA aggregates, rather than with tiny dsRNA granules, suggesting that the increase in the size of VRCs promotes their colocalization with MPs

Oxidative stress induction of DJ-1 protein in reactive astrocytes scavenges free radicals and reduces cell injury

Astrocytes, one of the predominant types of glial cells, function as both supportive and metabolic cells for the brain. Under cerebral ischemia/reperfusion-induced oxidative conditions, astrocytes accumulate and activate in the ischemic region. DJ-1 has recently been shown to be a sensor of oxidative stress in living cells. However, the function of astrocytic DJ-1 is still unknown. In the present study, to clarify the effect of astrocytic DJ-1 protein under massive oxidative insult, we used a focal ischemic rat model that had been subjected to middle cerebral artery occlusion (MCAO) and reperfusion. We then investigated changes in the distribution of DJ-1 in astrocytes, DJ-1 release from cultured astrocytes, and the effects of recombinant DJ-1 protein on hydrogen peroxide (H2O2)-induced death in normal and DJ-1-knockdown SH-SY5Y cells and on in vitro scavenging of hydroxyl radicals (•OH) by electron spin resonance spectrometry. At 24 h after 2-h MCAO and reperfusion, an infarct lesion was markedly observed using magnetic resonance imaging and 2,3,5-triphenyltetrazolium chloride staining. In addition, reactive astrocytes enhanced DJ-1 expression in the penumbral zone of the ischemic core and that DJ-1 protein was extracellularly released from astrocytes by H2O2 in in vitro primary cultures. Although DJ-1-knockdown SH-SY5Y cells were markedly vulnerable to oxidative stress, treatment with glutathione S-transferase-tagged recombinant human DJ-1 protein (GST-DJ-1) significantly inhibited H2O2-induced cell death. In addition, GST-DJ-1 protein directly scavenged •OH. These results suggest that oxidative stress induces the release of astrocytic DJ-1 protein, which may contribute to astrocyte-mediated neuroprotection

ゾルーゲル転移を示す生体適合ポリマー材料の開発と応用 (1)

We investigated the release behavior of glucagon-like peptide-1 (GLP-1) from a biodegradable injectable polymer (IP) hydrogel. This hydrogel shows temperature-responsive irreversible gelation due to the covalent bond formation through a thiol-ene reaction. In vitro sustained release of GLP-1 from an irreversible IP formulation (F(P1/D+PA40)) was observed compared with a reversible (physical gelation) IP formulation (F(P1)). Moreover, pharmaceutically active levels of GLP-1 were maintained in blood after subcutaneous injection of the irreversible IP formulation into rats. This system should be useful for the minimally invasive sustained drug release of peptide drugs and other water-soluble bioactive reagents.P.4~P.14Title: Peptide Drug Release Behavior from Biodegradable Temperature-Responsive Injectable Hydrogels Exhibiting Irreversible GelationJournal: Gels Doi:https://doi.org/10.3390/gels3040038本研究の⼀部は 2016-2017 年度関⻄⼤学研究拠点形成⽀援経費において，研究課題「ゾル−ゲル転移を⽰す⽣体適合ポリマー材料の開発と応⽤」として研究費を受け，その成果を公表するものである

Analysis of Expression Patterns of MicroRNAs That Are Closely Associated With Renal Carcinogenesis

Background: MicroRNAs (miRNA) are frequently dysregulated in clear cell renal cell carcinoma (ccRCC).Objective: This study aimed to elucidate the role of miRNA expression patterns in renal carcinogenesis and to identify the specific miRNAs that exhibit expression patterns closely associated with patient outcomes.Methods: We examined the expression patterns of selected miRNAs, including miRNA-155-5p, miRNA-122-5p, miRNA-21-5p, miRNA-185-5p, miRNA-106a-5p, miRNA-106b-3p, miRNA-34b-3p, miRNA-210-3p, miRNA-141-3p, miRNA-200c-3p, miRNA-135a-5p, miRNA-30a-5p, miRNA-218-5p, miRNA-429, miRNA-200a-3p and miRNA-200b-3p, in 96 samples of ccRCCs using the TaqMan real-time PCR method. In addition, cluster analysis was performed to stratify expression patterns of multiple miRNAs.Results: In the present study, three distinct subgroups could be clearly stratified in ccRCCs. Subgroup 1 was characterized by upregulation of miRNA-155-5p, miRNA-122-5p, miRNA-21-5p, miRNA-185-5p, miRNA-106a-5p, miRNA-106b-3p, miRNA-34b-3p and miRNA-210-3p. Subgroup 2 was closely associated with downregulation of miRNA-141-3p, miRNA200c-3p, miRNA-30a-5p, miRNA-218-5p, miRNA-429, miRNA-200a-3p and miRNA-200b-3p. Moreover, significant lower expression of miRNA-135a-5p was a distinctive feature of subgroup 3, which was correlated with metachronous metastasis. Among the individual markers in subgroup 3, miRNA-135a-5p was retained in multivariate analysis. The cutoff value of miRNA-135a-5p expression to identify the association of an altered level of miRNA-135a-5p with metachronous metastasis in ccRCCs was determined and showed excellent specificity.Conclusion: We suggest that the expression pattern of the chosen miRNAs is useful to identify renal carcinogenesis and to help identify the association of such expression patterns with metachronous metastasis in ccRCCs. In addition, miRNA-135a-5p was an excellent marker for prediction of metachronous metastasis

Analysis of the 619 Brånemark System TiUnite Implants : A Retrospective Study

The purpose of this retrospective study was to determine the outcome of Brånemark System TiUnite® implants (Nobel Biocare/Sweden), and to identify the risk factors associated with implant failure. A total of 151 patients (83 maxillae and 91 mandibles) received 619 implants from July 2003 until May 2010. The patients included 86 males and 65 females, with a median age of 51.6 years and an age range of 16 to 90 years at the time of implant surgery. Seventeen maxillae and 16 mandibles were completely edentulous, and 66 maxillae and 75 mandibles were partially edentulous. All the patients were followed until June 2011. Among the 619 implants, 9 maxillary implants and 8 mandibular implants were unsuccessful. The overall survival rate was 96.82%. A logistic regression analysis identified that a history of steroid treatment, application of a dento-maxillary prosthesis, a lack of mechanical coupling between the implants, and the length of the implants (≤8.5mm) were significant predictors of implant failure

Oxidative Neurodegeneration Is Prevented by UCP0045037, an Allosteric Modulator for the Reduced Form of DJ-1, a Wild-Type of Familial Parkinson’s Disease-Linked PARK7

Although a loss-of-function mutation has been identified in familial Parkinson’s disease PARK7, the wild-type of DJ-1 is known to act as an oxidative stress sensor in neuronal cells. Recently, we identified UCP0045037 as a compound that bound to the reduced form of DJ-1 by in silico virtual screening. In this study, we determined the neuroprotective effects of UCP0045037 against focal cerebral ischemia-induced neurodegeneration in rats. Hydrogen peroxide-induced cell death was significantly inhibited by UCP0045037 in both rat mesencephalic dopaminergic neurons and human normal SH-SY5Y cells. In contrast, DJ-1-knockdown SH-SY5Y cells lost the protective activity of UCP0045037. These results suggest that UCP0045037 interacts with endogenous DJ-1 and produces a neuroprotective response

Effects of Intermediates between Vitamins K2 and K3 on Mammalian DNA Polymerase Inhibition and Anti-Inflammatory Activity

Previously, we reported that vitamin K3 (VK3), but not VK1 or VK2 (=MK-4), inhibits the activity of human DNA polymerase γ (pol γ). In this study, we chemically synthesized three intermediate compounds between VK2 and VK3, namely MK-3, MK-2 and MK-1, and investigated the inhibitory effects of all five compounds on the activity of mammalian pols. Among these compounds, MK-2 was the strongest inhibitor of mammalian pols α, κ and λ, which belong to the B, Y and X families of pols, respectively; whereas VK3 was the strongest inhibitor of human pol γ, an A-family pol. MK-2 potently inhibited the activity of all animal species of pol tested, and its inhibitory effect on pol λ activity was the strongest with an IC50 value of 24.6 μM. However, MK-2 did not affect the activity of plant or prokaryotic pols, or that of other DNA metabolic enzymes such as primase of pol α, RNA polymerase, polynucleotide kinase or deoxyribonuclease I. Because we previously found a positive relationship between pol λ inhibition and anti-inflammatory action, we examined whether these compounds could inhibit inflammatory responses. Among the five compounds tested, MK-2 caused the greatest reduction in 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced acute inflammation in mouse ear. In addition, in a cell culture system using mouse macrophages, MK-2 displayed the strongest suppression of the production of tumor necrosis factor (TNF)-α induced by lipopolysaccharide (LPS). Moreover, MK-2 was found to inhibit the action of nuclear factor (NF)-κB. In an in vivo mouse model of LPS-evoked acute inflammation, intraperitoneal injection of MK-2 in mice led to suppression of TNF-α production in serum. In conclusion, this study has identified VK2 and VK3 intermediates, such as MK-2, that are promising anti-inflammatory candidates