ATP-dependent protease ClpP and its subunits ClpA, ClpB, and ClpX involved in the field bismerthiazol-resistance in Xanthomonas oryzae pv. oryzae

2021 ◽  
Author(s):  
Yuan Ni ◽  
Yi-Ping Hou ◽  
Jinbo Kang ◽  
Zhou Mingguo
Keyword(s):  
Growth Phase ◽  
Xanthomonas Oryzae ◽  
Exopolysaccharide Production ◽  
Enhanced Resistance ◽  
Increased Sensitivity ◽  
Resistant Strains ◽  
Early Growth Phase ◽  
Utilization Pathway

Resistance of Xanthomonas oryzae pv. oryzae (Xoo), which causes rice bacterial leaf blight, to bismerthiazol has been detected in China since the 1990s. Interestingly, the strains resistant to bismerthiazol on rice plants were more sensitive to bismerthiazol than wild-type (WT) strains in vitro. Here, qPCR was applied to detect the fold expression of ATP-dependent proteases, ClpP and its subunits, which cope with stresses including bactericides in bismerthiazol-resistant strains and their parental susceptible WT strain (ZJ173). Results showed that the expression of ClpP and its subunits were all higher in bismerthiazol-resistant strains than that in ZJ173. They were up-regulated during early growth phase and down-regulated during middle growth phase in ZJ173 treated with bismerthiazol but did not change in the resistant strains. ClpP and its subunits were overexpressed in Xoo in this study, the higher expression of these genes increased sensitivity in vitro and enhanced resistance in vivo to bismerthiazol. Inhibition of bismerthiazol to exopolysaccharide production, biofilm, and motility was also reduced in ClpP and its subunit’s overexpression mutants of Xoo. The deletion mutants of ClpP and its subunits in ZJ173 abated pathogenicity, biofilm production, swimming ability, exopolysaccharide production, and growth in low-nutrient environments. Moreover, ClpP and its subunits may act downstream of the histidine utilization pathway, which could be inhibited by bismerthiazol in Xoo. Taken together, our results indicated that ClpP and its subunits of Xoo influenced the resistance to bismerthiazol.

scholarly journals Inhibition of Premature Oocyte Maturation: A Role for Bone Morphogenetic Protein 15 in Zebrafish Ovarian Follicles

Endocrinology ◽  
2007 ◽  
Vol 148 (11) ◽  
pp. 5451-5458 ◽  
Author(s):  
Eric S. Clelland ◽  
Qian Tan ◽  
Ari Balofsky ◽  
Rosie Lacivita ◽  
Chun Peng
Keyword(s):  
Bone Morphogenetic Protein ◽  
Oocyte Maturation ◽  
Growth Phase ◽  
Early Growth ◽  
Preimmune Serum ◽  
Morphogenetic Protein ◽  
Bone Morphogenetic Protein 15 ◽  
Early Growth Phase

Bone morphogenetic protein-15 (BMP-15) is a member of the TGF-β superfamily known to regulate ovarian functions in mammals. Recently, we cloned zebrafish BMP-15 (zfBMP-15) cDNA and demonstrated that it may play a role in oocyte maturation. In this study, we further investigated the role of BMP-15 in zebrafish follicular development and oocyte maturation using an antiserum developed for zfBMP-15 and by microinjection of follicles with antisense zfBMP-15 N-morpholino oligonucleotides or an expression construct containing zfBMP-15 cDNA. Injection with antiserum caused a significant decrease in maturation-incompetent [insensitive to maturation-inducing hormone (MIH)] early growth phase follicles and a concomitant increase in mature follicles in vivo. In vitro maturation assays showed that incubation with antiserum resulted in a significant increase in oocyte maturation as compared with follicles incubated in preimmune serum or media control. Next, early growth phase follicles were collected and preincubated with either antiserum, preimmune serum, or medium control before treatment with MIH or human chorionic gonadotropin (hCG). Antiserum significantly increased oocyte maturation in response to MIH, but not to hCG, and enhanced basal maturation rate in longer-term incubations. Knockdown of BMP-15 in early growth stage follicles with a BMP-15 antisense oligonucleotide resulted in increased oocyte maturation, whereas microinjection of BMP-15 cDNA into oocytes significantly reduced MIH- and hCG-induced oocyte maturation in normally competent, mid-growth-phase follicles. Collectively, these findings suggest that BMP-15 modulates follicular growth and prevents premature oocyte maturation in zebrafish, in part, by suppressing the sensitivity of follicles to MIH.

scholarly journals Silver Nanoparticles and Their Antibacterial Applications

2021 ◽  
Vol 22 (13) ◽  
pp. 7202
Author(s):  
Tamara Bruna ◽  
Francisca Maldonado-Bravo ◽  
Paul Jara ◽  
Nelson Caro
Keyword(s):  
Silver Nanoparticles ◽  
Antibacterial Agents ◽  
Multidrug Resistant ◽  
Secondary Effects ◽  
Cytotoxic Effects ◽  
Factors Affecting ◽  
Gram Positive Bacteria ◽  
Resistant Strains

Silver nanoparticles (AgNPs) have been imposed as an excellent antimicrobial agent being able to combat bacteria in vitro and in vivo causing infections. The antibacterial capacity of AgNPs covers Gram-negative and Gram-positive bacteria, including multidrug resistant strains. AgNPs exhibit multiple and simultaneous mechanisms of action and in combination with antibacterial agents as organic compounds or antibiotics it has shown synergistic effect against pathogens bacteria such as Escherichia coli and Staphylococcus aureus. The characteristics of silver nanoparticles make them suitable for their application in medical and healthcare products where they may treat infections or prevent them efficiently. With the urgent need for new efficient antibacterial agents, this review aims to establish factors affecting antibacterial and cytotoxic effects of silver nanoparticles, as well as to expose the advantages of using AgNPs as new antibacterial agents in combination with antibiotic, which will reduce the dosage needed and prevent secondary effects associated to both.

Synthesis and turnover of proteins and mRNA in germinating wheat embryos

1982 ◽  
Vol 60 (3) ◽  
pp. 389-397 ◽  
Author(s):  
Zbyszko F. Grzelczak ◽  
Mark H. Sattolo ◽  
Linda K. Hanley-Bowdoin ◽  
Theresa D. Kennedy ◽  
Byron G. Lane
Keyword(s):  
Growth Phase ◽  
Time Course ◽  
Phase 1 ◽  
Major Product ◽  
Lag Phase ◽  
Wheat Embryo ◽  
Phase Development ◽  
Wheat Embryos

The most prominent methionine-labeled protein made when cell-free systems are programmed with bulk mRNA from dry wheat embryos has been identified with what may be the most abundant protein in dry wheat embryos. The protein has been brought to purity and has a distinctive amino acid composition, Gly and Glx accounting for almost 40% of the total amino acids. Designated E because of its conspicuous association with early imbibition of dry wheat embryos, the protein and its mRNA are abundant during the "early" phase (0–1 h) of postimbibition development, and easily detected during "lag" phase (1–5 h), but they are almost totally degraded soon after entry into the "growth" phase of development, by about 10 h postimbibition.The most prominent methionine-labeled protein peculiar to the cell-free translational capacity of bulk mRNA from "growth" phase embryos is not detected as a product of in vivo synthesis. Its electrophoretic properties and its time course of emergence, after 5 h postimbibition development, suggest that this major product of cell-free synthesis may be an in vitro counterpart to a prominent methionine-labeled protein made only in vivo, by "growth" phase embryos. Designated G because of its conspicuous association with "growth" phase development, the cell-free product does not comigrate with any prominent dye-stained band in electrophoretic distributions of wheat proteins. The suspected cellular counterpart to G, also, does not comigrate with a prominent dye-stained wheat protein during electrophoresis, and although found in particulate as well as soluble fractions of wheat embryo homogenates it is not concentrated in either nuclei or mitochondria, as isolated.

Enhanced resistance artery sensitivity to agonists under isobaric compared with isometric conditions

1994 ◽  
Vol 266 (1) ◽  
pp. H147-H155 ◽  
Author(s):  
W. R. Dunn ◽  
G. C. Wellman ◽  
J. A. Bevan
Keyword(s):  
Membrane Potential ◽  
Angiotensin Ii ◽  
Myogenic Tone ◽  
Isometric Contractions ◽  
Fundamental Interaction ◽  
Resistance Artery ◽  
Resistance Arteries ◽  
Enhanced Resistance ◽  
Increased Sensitivity

We have compared the responsiveness of rabbit mesenteric resistance arteries with agonists under isometric and isobaric conditions. When pressurized (60 mmHg), arteries spontaneously reduced their diameter by 18.1%. An equivalent isometric stress did not generate force in a “wire” myograph. Subsequently, much higher concentrations of norepinephrine (NE) and histamine were required to cause isometric contractions than were needed to reduce vascular diameter of pressurized vessels, whereas angiotensin II produced a maintained response only in pressurized arteries. Reducing transmural pressure to 20 mmHg abolished pressure-induced myogenic tone and decreased arterial sensitivity to NE. Under isometric conditions, partial depolarization with KCl increased sensitivity to NE and histamine to within the concentration range effective in pressurized vessels and also "revealed" responses to angiotensin II. The membrane potential of the vascular smooth muscle cells under partially depolarized conditions was similar to that found in vivo and in vessels studied isobarically. These observations demonstrate a fundamental interaction between pressure-induced myogenic tone and the sensitivity of resistance arteries to vasoactive stimuli. This influence was mimicked in isometrically mounted vessels by partial depolarization, indicating a possible pivotal role for membrane potential in determining the reactivity of the resistance vasculature.

scholarly journals In vivo and in vitro antiplasmodial activities of some plants traditionally used in Guatemala against malaria.

1997 ◽  
Vol 41 (7) ◽  
pp. 1500-1503 ◽  
Author(s):  
F F Franssen ◽  
L J Smeijsters ◽  
I Berger ◽  
B E Medinilla Aldana
Keyword(s):  
Plasmodium Berghei ◽  
Brine Shrimp ◽  
Folk Medicine ◽  
Artemia Salina ◽  
In Vitro Cultures ◽  
Cytotoxic Effects ◽  
Resistant Strains ◽  
Simarouba Glauca

We present an evaluation of the antiplasmodial and cytotoxic effects of four plants commonly used in Guatemalan folk medicine against malaria. Methanol extracts of Simarouba glauca D. C., Sansevieria guineensis Willd, Croton guatemalensis Lotsy, and Neurolaena lobata (L.)R.Br. significantly reduced parasitemias in Plasmodium berghei-infected mice. Dichloromethane fractions were screened for their cytotoxicities on Artemia salina (brine shrimp) larvae, and 50% inhibitory concentrations were determined for Plasmodium falciparum in in vitro cultures. Both chloroquine-susceptible and -resistant strains of P. falciparum were significantly inhibited by these extracts. Of all dichloromethane extracts, only the S. glauca cortex extract was considered to be toxic to nauplii of A. salina in the brine shrimp test.

scholarly journals In Vitro and In Vivo Antimalarial Activities of a Carbohydrate Antibiotic, Prumycin, against Drug-resistant Strains of Plasmodia

2004 ◽  
Vol 57 (6) ◽  
pp. 400-402 ◽  
Author(s):  
KAZUHIKO OTOGURO ◽  
AKI ISHIYAMA ◽  
MIYUKI KOBAYASHI ◽  
HITOMI SEKIGUCHI ◽  
TAKASHI IZUHARA ◽  
...  
Keyword(s):  
Drug Resistant ◽  
Resistant Strains ◽  
Drug Resistant Strains

Aerobic resistance of Trichomonas vaginalis to metronidazole induced in vitro

Parasitology ◽  
1993 ◽  
Vol 106 (1) ◽  
pp. 31-37 ◽  
Author(s):  
J. Tachezy ◽  
J. Kulda ◽  
E. Tomková
Keyword(s):  
Parent Strain ◽  
Trichomonas Vaginalis ◽  
Drug Resistant ◽  
Ferredoxin Oxidoreductase ◽  
Low Concentrations ◽  
Percent Concentration ◽  
Resistant Strains ◽  
Pyruvate Ferredoxin Oxidoreductase

SUMMARYAerobic resistance of Trichomonas vaginalis to metronidazole was induced in vitro by anaerobic cultivation of drug-susceptible trichomonads with low concentrations of the drug (2–3 μg/ml) for 50 days. Minimal lethal concentrations (MLC) for metronidazole of the resistant derivatives were high in aerobic susceptibility assays (MLC = 216–261.5 μg/ml) but low in anaerobic assays (MLC = 4.2–6.3 μg/ml), surpassing MLC values of their parent strain approximately 50-fold and 3-fold under aerobiosis and anaerobiosis, respectively. Sensitivity to metronidazole under anaerobic conditions and activity of the hydrogenosomal enzyme pyruvate: ferredoxin oxidoreductase indicated that the resistance was of the aerobic type. Dependence of the resistance manifestation on O2 was further confirmed by susceptibility assays in vitro performed in defined gas mixtures of different oxygen content (1–20%). Five percent concentration of O2 proved to be the threshold required for resistance demonstration and the MLC values further increased with increasing O2 concentrations. The in vitro-induced resistance was also demonstrated in vivo by subcutaneous mouse assay. The dose of metronidazole needed to cure 50% of infected mice (DC50) was 223 mg/kg × 3 for resistant derivative MR-3a but 6.6 mg/kg × 3 only for its drug-susceptible parent strain. The metronidazole – resistant strains developed in this study correspond by their properties to drug-resistant T. vaginalis strains isolated from patients refractory to treatment, and promise to be a useful tool in the study of 5-nitroimidazole aerobic resistance.

Efficacy of Pyrazolopyrimidine Ribonucleosides Against Irypanosoma cruzi: Studies in Vitro and in Vivo with Sensitive and Resistant Strains

1984 ◽  
Vol 150 (4) ◽  
pp. 602-608 ◽  
Author(s):  
R. L. Berens ◽  
J. J. Marr ◽  
D. L. Looker ◽  
D. J. Nelson ◽  
S. W. LaFon
Keyword(s):  
Resistant Strains

scholarly journals Thrombospondin-1 promotes haemostasis through modulation of cAMP signalling in blood platelets.

Blood ◽  
2020 ◽  
Author(s):  
Ahmed Aburima ◽  
Martin Berger ◽  
Benjamin EJ Spurgeon ◽  
Beth A Webb ◽  
Katie S Wraith ◽  
...  
Keyword(s):  
Platelet Activation ◽  
Blood Platelets ◽  
Camp Signaling ◽  
Camp Accumulation ◽  
In Vivo Models ◽  
Downstream Signaling ◽  
Thrombospondin 1 ◽  
Increased Sensitivity

Thrombospondin-1 (TSP-1) is released by platelets upon activation and can promote platelet activation, but its role in haemostasis in vivo is unclear. We show that TSP-1 is a critical mediator of haemostasis that promotes platelet activation by modulating inhibitory cAMP signaling. Genetic deletion of TSP-1 did not affect platelet activation in vitro, but in vivo models of haemostasis and thrombosis demonstrated that TSP-1 deficient mice had prolonged bleeding, defective thrombosis and increased sensitivity to the prostacyclin mimetic iloprost. Adoptive transfer of wild type (WT), but not TSP-1-/- platelets, ameliorated the thrombotic phenotype, suggesting a key role for platelet-derived TSP-1. In functional assays, TSP-1-deficient platelets showed an increased sensitivity to cAMP signaling, inhibition of platelet aggregation and arrest under flow by PGI2. Plasma swap experiments showed that plasma TSP-1 did not correct PGI2 hypersensitivity in TSP-1-/- platelets. By contrast, incubation of TSP-1-/- platelets with releasates from WT platelets or purified TSP-1, but not releasates from TSP-1-/- platelets, reduced the inhibitory effects of PGI2. Activation of WT platelets resulted in diminished cAMP accumulation and downstream signaling, which was associated with increased activity of the cAMP hydrolyzing enzyme phosphodiesterase 3A (PDE3A). PDE3A activity and cAMP accumulation were unaffected in platelets from TSP-1-/- mice. Platelets deficient in CD36, a TSP-1 receptor, showed increased sensitivity to PGI2/cAMP signaling and diminished PDE3A activity, which was unaffected by platelet-derived or purified TSP-1. This suggests that the release of TSP-1 regulates haemostasis in vivo through modulation of platelet cAMP signaling at sites of vascular injury.

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