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101.
Shinsuke Mikami Ayumu Nakashima Keigo Nakagawa Tatsuya Maruhashi Yumiko Iwamoto Masato Kajikawa Takeshi Matsumoto Yasuki Kihara Kazuaki Chayama Kensuke Noma Mitsuo Ochi Masahiro Nishimura Koichiro Tsuji Yukio Kato Chikara Goto Yukihito Higashi 《PloS one》2013,8(7)
Background
The purpose of this study was to determine whether autologous mesenchymal stem cells (MSCs) implantation improves endothelial dysfunction in a rabbit ischemic limb model.Methods
We evaluated the effect of MSC implantation on limb blood flow (LBF) responses to acetylcholine (ACh), an endothelium-dependent vasodilator, and sodium nitroprusside (SNP), an endothelium-independent vasodilator, in rabbits with limb ischemia in which cultured MSCs were implanted (n = 20) or saline was injected as a control group (n = 20). LBF was measured using an electromagnetic flowmeter. A total of 106 MSCs were implanted into each ischemic limb.Results
Histological sections of ischemic muscle showed that capillary index (capillary/muscle fiber) was greater in the MSC implantation group than in the control group. Laser Doppler blood perfusion index was significantly increased in the MSC implantation group compared with that in the control group. LBF response to ACh was greater in the MSC group than in the control group. After administration of NG-nitro-L-arginine, a nitric oxide synthase inhibitor, LBF response to ACh was similar in the MSC implantation group and control group. Vasodilatory effects of SNP in the two groups were similar.Conclusions
These findings suggest that MSC implantation induces angiogenesis and augments endothelium-dependent vasodilation in a rabbit ischemic model through an increase in nitric oxide production. 相似文献102.
103.
Yanagisawa Takahiro Ishii Masakazu Takahashi Manami Fujishima Kei Nishimura Masahiro 《Molecular biology reports》2020,47(9):6841-6854
Molecular Biology Reports - LL-37, the only member of the cathelicidin family of cationic antimicrobial peptides in humans has been shown to exhibit a wide variety of biological actions in addition... 相似文献
104.
Akihiko Shimizu Hiroyuki Tsukagoshi Tsuyoshi Sekizuka Makoto Kuroda Aya Koizumi Masahiro Fujita Yoshiyuki Yamada Nobuhiro Saruki 《Microbiology and immunology》2020,64(9):630-634
Group B streptococcus (GBS) is a leading cause of neonatal infections. Most isolates are β-hemolytic, and their activity is considered to be pivotal for GBS pathogenicity. We report a case of a neonate with meningitis caused by nonhemolytic GBS. The patient developed meningitis 3 days after birth. Genotyping was performed and the characteristics of the strain (GCMC97051) identified by whole genome sequence using next generation sequencing. GCMC97051 possesses genetic alterations such as disruption of cylA by IS1381A insertion and a frameshift mutation in cylE, resulting in a lack of hemolysis. Thus, nonhemolytic GBS can retain the potential to cause invasive infections. 相似文献
105.
Kae Higuchi Takashi Yabuki Masahiro Ito Takanori Kigawa 《Biotechnology and bioengineering》2020,117(6):1628-1639
Protein folding is usually slowed-down at low temperatures, and thus low-temperature expression is an effective strategy to improve the soluble yield of aggregation-prone proteins. In this study, we investigated the effects of a variety of cold shock proteins and domains (Csps) on an Escherichia coli cell extract-based cell-free protein synthesis system (CF). Most of the 12 Csps that were successfully prepared dramatically improved the protein yields, by factors of more than 5 at 16°C and 2 at 23°C, to levels comparable to those obtained at 30°C. Their stimulatory effects were complementary to each other, while CspD and CspH were inhibitory. The Csps’ effects correlated well with their Pfam CSD family scores (PF00313.22). All of the investigated Csps, except CspH, similarly possessed RNA binding and chaperon activities and increased the messenger RNA amount irrespective of their effect, suggesting that the proper balance between these activities was required for the enhancement. Unexpectedly, the 5′-untranslated region of cspA was less effective as the leader sequence. Our results demonstrated that the use of the Csps presented in this study will provide a simple and highly effective strategy for the CF, to improve the soluble yields of aggregation-prone proteins. 相似文献
106.
Naoto Burioka Miyako Takata Masahiro Endo Masanori Miyata Kenichi Takeda Hiroki Chikumi 《Chronobiology international》2013,30(1):183-189
This study examined whether in vivo exposure to a β2‐adrenoceptor agonist, tulobuterol, induces human Period1 (hPer1) mRNA expression in cells from peripheral whole blood. In one experiment, oral tulobuterol was administered to five healthy volunteers at 22:00 h, while in another, a transdermally tulobuterol patch was applied to the same five subjects at 20:00 h. In each experiment, serum tulobuterol concentrations were measured at four time points, and total RNA was isolated from peripheral blood cells for determinations of hPer1 mRNA expression by real‐time polymerase chain reaction. Both the tulobuterol tablet and the transdermal patch increased hPer1 mRNA expression, suggesting that analyses of human peripheral blood cells could reliably represent peripheral clock gene mRNA expression in vivo. 相似文献
107.
Toko Tanikawa Yasuhiro Hirano Masako Dannoura Keitarou Yamase Kenji Aono Masahiro Ishii Tetsurou Igarashi Hidetoshi Ikeno Yoichi Kanazawa 《Plant and Soil》2013,373(1-2):317-327
Aim
Ground-penetrating radar (GPR) has been applied to detect coarse tree roots. The horizontal angle of a root crossing a scanning line is a factor that affects both root detection and waveform parameter values. The purpose of this study was to quantitatively evaluate the influence of root orientation (x, degree) on two major waveform parameters, amplitude area (A, dB × ns) and time interval between zero crossings (T, ns).Methods
We scanned four diameter classes of dowels in a sandy bed as simulated roots using a 900 MHz antenna from multiple angles to clarify the relationships between the parameters and x.Results
Angle x strongly affected reflection images and A values. The variation in A(x) fitted a sinusoidal waveform, whereas T was independent of x. The value of A scanning at 90° was estimated by A values of arbitrary x in two orthogonal transects. The sum of T in all reflected waveforms showed a significant linear correlation with dowel diameter.Conclusions
We clarified that root orientation dramatically affected root detection and A values. The sum of T of all reflected waveforms was a suitable parameter for estimating root diameter. Applying grid transects can overcome the effects of root orientation. 相似文献108.
Masatsugu Toyota Takuya Furuichi Masahiro Sokabe Hitoshi Tatsumi 《Plant physiology》2013,163(2):543-554
Gravity is a critical environmental factor affecting the morphology and functions of organisms on the Earth. Plants sense changes in the gravity vector (gravistimulation) and regulate their growth direction accordingly. In Arabidopsis (Arabidopsis thaliana) seedlings, gravistimulation, achieved by rotating the specimens under the ambient 1g of the Earth, is known to induce a biphasic (transient and sustained) increase in cytoplasmic calcium concentration ([Ca2+]c). However, the [Ca2+]c increase genuinely caused by gravistimulation has not been identified because gravistimulation is generally accompanied by rotation of specimens on the ground (1g), adding an additional mechanical signal to the treatment. Here, we demonstrate a gravistimulation-specific Ca2+ response in Arabidopsis seedlings by separating rotation from gravistimulation by using the microgravity (less than 10−4g) conditions provided by parabolic flights. Gravistimulation without rotating the specimen caused a sustained [Ca2+]c increase, which corresponds closely to the second sustained [Ca2+]c increase observed in ground experiments. The [Ca2+]c increases were analyzed under a variety of gravity intensities (e.g. 0.5g, 1.5g, or 2g) combined with rapid switching between hypergravity and microgravity, demonstrating that Arabidopsis seedlings possess a very rapid gravity-sensing mechanism linearly transducing a wide range of gravitational changes (0.5g–2g) into Ca2+ signals on a subsecond time scale.Calcium ion (Ca2+) functions as an intracellular second messenger in many signaling pathways in plants (White and Broadley, 2003; Hetherington and Brownlee, 2004; McAinsh and Pittman, 2009; Spalding and Harper, 2011). Endogenous and exogenous signals are spatiotemporally encoded by changing the free cytoplasmic concentration of Ca2+ ([Ca2+]c), which in turn triggers [Ca2+]c-dependent downstream signaling (Sanders et al., 2002; Dodd et al., 2010). A variety of [Ca2+]c increases induced by diverse environmental and developmental stimuli are reported, such as phytohormones (Allen et al., 2000), temperature (Plieth et al., 1999; Dodd et al., 2006), and touch (Knight et al., 1991; Monshausen et al., 2009). The [Ca2+]c increase couples each stimulus and appropriate physiological responses. In the Ca2+ signaling pathways, the stimulus-specific [Ca2+]c pattern (e.g. amplitude and oscillation) provide the critical information for cellular signaling (Scrase-Field and Knight, 2003; Dodd et al., 2010). Therefore, identification of the stimulus-specific [Ca2+]c signature is crucial for an understanding of the intracellular signaling pathways and physiological responses triggered by each stimulus, as shown in the case of cold acclimation (Knight et al., 1996; Knight and Knight, 2000).Plants often exhibit biphasic [Ca2+]c increases in response to environmental stimuli. Thus, slow cooling causes a fast [Ca2+]c transient followed by a second, extended [Ca2+]c increase in Arabidopsis (Arabidopsis thaliana; Plieth et al., 1999; Knight and Knight, 2000). The Ca2+ channel blocker lanthanum (La3+) attenuated the fast transient but not the following increase (Knight and Knight, 2000), suggesting that these two [Ca2+]c peaks have different origins. Similarly, hypoosmotic shock caused a biphasic [Ca2+]c increase in tobacco (Nicotiana tabacum) suspension-culture cells (Takahashi et al., 1997; Cessna et al., 1998). The first [Ca2+]c peak was inhibited by gadolinium (Gd3+), La3+, and the Ca2+ chelator EGTA (Takahashi et al., 1997; Cessna et al., 1998), whereas the second [Ca2+]c increase was inhibited by the intracellular Ca2+ store-depleting agent caffeine but not by EGTA (Cessna et al., 1998). The amplitude of the first [Ca2+]c peak affected the amplitude of the second increase and vice versa (Cessna et al., 1998). These results suggest that even though the two [Ca2+]c peaks originate from different Ca2+ fluxes (e.g. Ca2+ influx through the plasma membrane and Ca2+ release from subcellular stores, respectively), they are closely interrelated, showing the importance of the kinetic and pharmacological analyses of these [Ca2+]c increases.Changes in the gravity vector (gravistimulation) could work as crucial environmental stimuli in plants and are generally achieved by rotating the specimens (e.g. +180°) in ground experiments. Use of Arabidopsis seedlings expressing apoaequorin, a Ca2+-reporting photoprotein (Plieth and Trewavas, 2002; Toyota et al., 2008a), has revealed that gravistimulation induces a biphasic [Ca2+]c increase that may be involved in the sensory pathway for gravity perception/response (Pickard, 2007; Toyota and Gilroy, 2013) and the intracellular distribution of auxin transporters (Benjamins et al., 2003; Zhang et al., 2011). These two Ca2+ changes have different characteristics. The first transient [Ca2+]c increase depends on the rotational velocity but not angle, whereas the second sustained [Ca2+]c increase depends on the rotational angle but not velocity. The first [Ca2+]c transient was inhibited by Gd3+, La3+, and the Ca2+ chelator 1,2-bis(2-aminophenoxy)ethane-N,N,N′,N′-tetraacetic acid but not by ruthenium red (RR), whereas the second sustained [Ca2+]c increase was inhibited by all these chemicals. These results suggest that the first transient and second sustained [Ca2+]c increases are related to the rotational stimulation and the gravistimulation, respectively, and are mediated by distinct molecular mechanisms (Toyota et al., 2008a). However, it has not been demonstrated directly that the second sustained [Ca2+]c increase is induced solely by gravistimulation; it could be influenced by other factors, such as an interaction with the first transient [Ca2+]c increase (Cessna et al., 1998), vibration, and/or deformation of plants during the rotation.To elucidate the genuine Ca2+ signature in response to gravistimulation in plants, we separated rotation and gravistimulation under microgravity (μg; less than 10−4g) conditions provided by parabolic flight (PF). Using this approach, we were able to apply rotation and gravistimulation to plants separately (Fig. 1). When Arabidopsis seedlings were rotated +180° under μg conditions, the [Ca2+]c response to the rotation was transient and almost totally attenuated in a few seconds. Gravistimulation (transition from μg to 1.5g) was then applied to these prerotated specimens at the terminating phase of the PF. This gravistimulation without simultaneous rotation induced a sustained [Ca2+]c increase. The kinetic properties of this sustained [Ca2+]c increase were examined under different gravity intensities (0.5g–2g) and sequences of gravity intensity changes (Fig. 2A). This analysis revealed that gravistimulation-specific Ca2+ response has an almost linear dependency on gravitational acceleration (0.5g–2g) and an extremely rapid responsiveness of less than 1 s.Open in a separate windowFigure 1.Diagram of the experimental procedures for applying separately rotation and gravistimulation to Arabidopsis seedlings. Rotatory stimulation (green arrow) was applied by rotating the seedlings 180° under μg conditions, and 1.5g 180° rotation gravistimulation (blue arrow) was applied to the prerotated seedlings after μg.Open in a separate windowFigure 2.Acceleration, temperature, humidity, and pressure in an aircraft during flight experiments. A, Accelerations along x, y, and z axes in the aircraft during PF. The direction of flight (FWD) and coordinates (x, y, and z) are indicated in the bottom graph. The inset shows an enlargement of the acceleration along the z axis (gravitational acceleration) during μg conditions lasting for approximately 20 s. B, Temperature, humidity, and pressure in the aircraft during PF. Shaded areas in graphs denote the μg condition. 相似文献
109.
Masrina Mohd Nadzir Masahiro Kino-oka Katsura Sugawara Masahito Taya 《Biotechnology letters》2013,35(2):295-300
The effect of insulin-like growth factor-1 (IGF-1) on the behavior of rabbit chondrocytes in cultured collagen (CL) gels initially seeded with 2 × 105 cells/ml was examined. On day 5, the frequency of migrating cells cultured in presence of 100 ng IGF-1/ml was 0.04, which was 54 % of the frequency in IGF-1-free culture. The presence of IGF-1 caused an increase in the frequency of dividing cells from 0.09 to 0.13. These results suggest that IGF-1 suppressed the migration of chondrocytes in the CL gels while stimulating cell division in the initial culture phase. The proteolytic migration of cells was thought to be suppressed by the down-regulation of membrane type 1 matrix metalloproteinase by IGF-1. This contributed to the formation of aggregates with spherical-shaped cells that produced collagen type II. 相似文献
110.
Function of a Glutamine Synthetase-Like Protein in Bacterial Aniline Oxidation via γ-Glutamylanilide
Masahiro Takeo Akira Ohara Shinji Sakae Yasuhiro Okamoto Chitoshi Kitamura Dai-ichiro Kato Seiji Negoro 《Journal of bacteriology》2013,195(19):4406-4414
Acinetobacter sp. strain YAA has five genes (atdA1 to atdA5) involved in aniline oxidation as a part of the aniline degradation gene cluster. From sequence analysis, the five genes were expected to encode a glutamine synthetase (GS)-like protein (AtdA1), a glutamine amidotransferase-like protein (AtdA2), and an aromatic compound dioxygenase (AtdA3, AtdA4, and AtdA5) (M. Takeo, T. Fujii, and Y. Maeda, J. Ferment. Bioeng. 85:17-24, 1998). A recombinant Pseudomonas strain harboring these five genes quantitatively converted aniline into catechol, demonstrating that catechol is the major oxidation product from aniline. To elucidate the function of the GS-like protein AtdA1 in aniline oxidation, we purified it from recombinant Escherichia coli harboring atdA1. The purified AtdA1 protein produced gamma-glutamylanilide (γ-GA) quantitatively from aniline and l-glutamate in the presence of ATP and MgCl2. This reaction was identical to glutamine synthesis by GS, except for the use of aniline instead of ammonia as the substrate. Recombinant Pseudomonas strains harboring the dioxygenase genes (atdA3 to atdA5) were unable to degrade aniline but converted γ-GA into catechol, indicating that γ-GA is an intermediate to catechol and a direct substrate for the dioxygenase. Unexpectedly, a recombinant Pseudomonas strain harboring only atdA2 hydrolyzed γ-GA into aniline, reversing the γ-GA formation by AtdA1. Deletion of atdA2 from atdA1 to atdA5 caused γ-GA accumulation from aniline in recombinant Pseudomonas cells and inhibited the growth of a recombinant Acinetobacter strain on aniline, suggesting that AtdA2 prevents γ-GA accumulation that is harmful to the host cell. 相似文献