インフルエンザ ウイルス ノ カンセン カンジュセイ オ ケッテイスル セイタイナイ インシグン ト ソノ サヨウ キジョ カラ ミル アラタナ チリョウ ヨボウ エノ テンカイ

Extracellular cleavage of virus envelope fusion glycoprotein, hemagglutinin, by host cellular proteases is a prerequisite for the infectivity of mammalian and nonpathogenic avian influenza viruses. In search of such target processing proteases in the airway, we found ectopic anionic trypsin I, tryptase Clara and mini-plasmin. Interestingly, these processing enzymes were localized in the air way with different distribution. In addition, these enzymes showed the different sensitivities to various strains of influenza A viruses. These findings suggested that host cellular proteases determine the susceptibility of influenza virus infection. On the other hand, the activity of these enzymes is strictly regulated by endogenous inhibitory compounds such as mucas protease inhibitor in the upper respiratory tract and pulmonary surfactant in the lower respiratory tract. Furthermore, we identified that ambroxol, known as a mucolytic agent, stimulate the suppressors of influenza-virus proliferation, such as mucas protease inhibitor, pulmonary surfactant and IgA. These findings suggested that the concentration of suppressors in the airway fluid significantly affect the pathogenicity of influenza virus infection. In this review, we discussed that the effects of antiviral compounds including ambroxol on prevention and treatment of influenza virus infection

Proteolytic activation of the precursor of membrane type 1 matrix metalloproteinase by human plasmin A possible cell surface activator

AbstractMembrane type 1 matrix metalloproteinase (MT1-MMP) was suggested to play a critical role in the regulation of tissue invasion by normal and neoplastic cells by directly mediating the activation of pro-gelatinase A. Recently, the proteolytic activation of a pro-MT1-MMP by an intracellular proprotein convertase, furin, was reported. In this study, we found that plasmin efficiently activates the pro-MT1-MMP by cleaving immediately downstream of Arg108 and Arg111 in the multi-basic motif between its pro- and catalytic domains that participates in the activation of pro-gelatinase A. Our present data suggest that pro-MT1-MMP transported to the plasma membrane is activated by plasmin extracellularly and thus it may play an important role in the matrix degradation process

トクシマ ダイガク エイヨウ ガッカ ハツ ウチュウ ジッケン ノ アユミ ト コレカラ

Yuri Gagarin said,“The Earth is blue”, in the first manned spacecraft Vostok 1 in April 1961 when he glimpsed the planet from the space. Since then, human beings have been evolving technology of rocket, so that they can stay in space for several months and years. In Japan, JAXA has almost finished constructing“Kibo”, a space experimental module in the International Space Station（ISS）, in August, 2008. The first space research of Japan will be carried out at“Kibo”soon.We are also planning to perform a space experiment in“Kibo”to clarify the molecular mechanism of muscle atrophy caused by micro gravity. In this paper, we report our history and future plan to develop space research

セイタイ ボウギョ インシグン ノ ブンピツ オ ソクシン スル エンサンアンブロキソール ノ コウインフルエンザ コウカ

Ambroxyol, known as a mucolytic agent, has been used for the treatment of chronic bronchitis and neonatal respiratory distress syndrome. Furthermore, ambroxol exhibits antioxidant and anti-inflammatory properties with reduction of the release of inflammatory cytokines. However, little is known about the pharmacological effect of ambroxol on influenza-virus infection in vivo. In this study, the protective effect of ambroxol against influenza-virus multiplication in the airway was investigated in mice. Ambroxol or the vehicle was administered intraperitonially twice a day for 5-7 days to mice shortly after intranasal infection with a lethal dose of influenza A/Aichi/68 (H3N2) virus, and the survival rate and levels of factors regulating virus multiplication in the airway fluid were analyzed. Ambroxol significantly suppressed virus multiplication and improved the survival rate of mice. Moreover, ambroxol stimulate the suppresors of infuluenza-virus multiplication, such as pulmonary surfactant, mucus protease inhibitor and IgA. These findings suggest that the effect of ambroxol on influenza-virus infection may result from the up-regulation of the suppressors. In this review, we discussed the effects of ambroxol on prevention and treatment of influenza virus infection

Inhibitory effect of FK506 and Cyclosporine A on the growth and invasion of human liver cancer cells

Background : The prognosis of liver transplantation for liver cancer is determined by recurrence in the liver graft. In this study, the effects of immunosuppressors, FK506 and cyclosporine A (CsA) on the migration of liver cancer cells were investigated. Methods : The effects of FK506 at concentrations of 1-100 ng/mL and CsA at 1-1000ng/mL on the growth of poorly and well differentiated human hepatocellular carcinoma cell lines, HLE and HuH-7, respectively, were examined. After treatment of these cells with FK506 and CsA, the growth of these cells, their cytotoxicities and invasion assay on the Matrigel basement membrane invasion chamber were evaluated. In addition, the effects of FK506 and CsA on the changes in the production of a soluble intercellular adhesionmolecule-1 (sICAM-1) of these cells were measured. Results : FK506 and CsA at concentrations of 1-10 ng/mL inhibited the growth of both HLE and HuH-7 and those immunosuppressors at concentrations over 100 ng/mL exhibited cytotoxicity on these cells. FK506 at concentration of 1ng/mL significantly inhibited the invasion of poorly differentiated HLE, but not well differentiated HuH-7, after treatment for 2-5 days in culture (p＜0.05), but FK 506 at 10 ng/mL showed less inhibitory efficient. CsA at concentrations of 1-10 ng/mL, however, did not inhibit or transiently inhibited the invasion of both cell lines. The production of ICAM-1 in HLE and HuH-7 was suppressed by FK506 at concentrations of 1-10 ng/mL after treatment for 3-5 days but the effect was not significant in the initial phase at days 1-2 and the last phase at days 5-6. Conclusions : FK506, but not CsA, at a clinical dose of 1ng/mL significantly inhibited the invasion of the poorly-differentiated HLE, but not HuH-7 and also inhibited the production of sICAM-1 in HLE

Uncoupling protein 3 attenuates generation of reactive oxygen species by interacting with thioredoxin 2 in the mitochondrial intermembrane space

Katsuya Hirasaka1*, Edward M Mills2, Shohei Kohno1, Tomoki Abe1, Chika Ikeda1, Tasuku Maeda1, Shigetada Kondo1, Ayako Maita1, Yuushi Okumura1 and Takeshi Nikawa1 Author Affiliations 1 Department of Nutritional Physiology, Institute of Health Biosciences, University of Tokushima, Tokushima, 770-8503, Japan 2 Division of Pharmacology/Toxicology, University of Texas at Austin, Austin, TX 78712, USAPoster presentation Uncoupling protein 3 (UCP3) is primarily expressed in the inner membrane of skeletal muscle mitochondria. It has been proposed that UCP3 reduces production of reactive oxygen species (ROS) and oxidative damage. However, the mechanisms by which UCP3 attenuates ROS production are not well understood. Here we report that UCP3 interacts with the non-processed form of thioredoxin 2 (Trx2), a redox protein that is localized in mitochondria, but not processed Trx2, which is involved in cellular responses to ROS. The hydrophilic sequences within the N-terminal tail of UCP3, which faces the intermembrane space, are necessary for binding to Trx2. In addition, Trx2 directly associated with UCP3 through a mitochondrial targeting signaling sequence, was processed in the intermembrane space, and thereby allowing redox reactions. A bimolecular fluorescence complementation analysis demonstrated that the interaction of these proteins occurs in the mitochondrial intermembrane space. Furthermore, increased UCP3 expression significantly attenuated ROS production in isolated mitochondrial without effects on membrane potential, however this effect is lost by Trx2 knock down. These results suggest that UCP3 binds to Trx2 in the mitochondrial intermembrane space and attenuates ROS production.Pharmac

Cloning, expression analysis, and tissue distribution of esp-1/testisin, a membrane-type serine protease from the rat

Esp-1/testisin, a serine protease abundantly expressed in human and mouse testis, is presumed to play an important role in the process of spermatogenesis and fertilization. In this study, we cloned an esp-1/testisin cDNA from rats, and analyzed its expression and tissue distribution. The isolated cDNA consisted of 1099 nucleotides with a single open reading frame encoding 328 amino acids and an expected molecular mass of 36.6 kDa. The deduced amino acid sequence of rat Esp-1/Testisin had 89% and 62% identity with its murine and human counterparts, respectively, and appeared to be a trypsin-type serine protease with a hydrophobic region at the C-terminus. By quantitative real-time polymerase chain reaction analysis, rat esp-1/testisin mRNA was predominantly expressed in testis, as in human and mouse. However, its immunohistochemical distribution was predominantly in the elongated spermatids at steps 12 to 19, and not in the primary spermatocytes and round spermatids. This different distribution profile suggests that Esp-1/Testisin plays a role in species-specific proteolytic events during spermatogenesis and fertilization

Structure of MSPL–inhibitor complex

Infection of certain influenza viruses is triggered when its HA is cleaved by host cell proteases such as proprotein convertases and type II transmembrane serine proteases (TTSP). HA with a monobasic motif is cleaved by trypsin-like proteases, including TMPRSS2 and HAT, whereas the multibasic motif found in high pathogenicity avian influenza HA is cleaved by furin, PC5/6, or MSPL. MSPL belongs to the TMPRSS family and preferentially cleaves [R/K]-K-K-R↓ sequences. Here, we solved the crystal structure of the extracellular region of human MSPL in complex with an irreversible substrate-analog inhibitor. The structure revealed three domains clustered around the C-terminal α-helix of the SPD. The inhibitor structure and its putative model show that the P1-Arg inserts into the S1 pocket, whereas the P2-Lys and P4-Arg interacts with the Asp/Glu-rich 99-loop that is unique to MSPL. Based on the structure of MSPL, we also constructed a homology model of TMPRSS2, which is essential for the activation of the SARS-CoV-2 spike protein and infection. The model may provide the structural insight for the drug development for COVID-19

Involvement of autophagy in trypsinogen activation within the pancreatic acinar cells

Autophagy is mostly a nonselective bulk degradation system within cells. Recent reports indicate that autophagy can act both as a protector and killer of the cell depending on the stage of the disease or the surrounding cellular environment (for review see Cuervo, A.M. 2004. Trends Cell Biol. 14:70–77). We found that cytoplasmic vacuoles induced in pancreatic acinar cells by experimental pancreatitis were autophagic in origin, as demonstrated by microtubule-associated protein 1 light chain 3 expression and electron microscopy experiments. To analyze the role of macroautophagy in acute pancreatitis, we produced conditional knockout mice lacking the autophagy-related 5 gene in acinar cells. Acute pancreatitis was not observed, except for very mild edema in a restricted area, in conditional knockout mice. Unexpectedly, trypsinogen activation was greatly reduced in the absence of autophagy. These results suggest that autophagy exerts devastating effects in pancreatic acinar cells by activation of trypsinogen to trypsin in the early stage of acute pancreatitis through delivering trypsinogen to the lysosome