scholarly journals Metabolic Fingerprinting for Identifying the Mode of Action of the Fungicide SYP-14288 on Rhizoctonia solani

2020 ◽  
Vol 11 ◽  
Author(s):  
Li Liang ◽  
Xingkai Cheng ◽  
Tan Dai ◽  
Zhiwen Wang ◽  
Jin Li ◽  
...  

The fungicide SYP-14288 has a high efficiency, low toxicity, and broad spectrum in inhibiting both fungi and oomycetes, but its mode of action (MoA) remains unclear on inhibiting fungi. In this study, the MoA was determined by analyzing the metabolism and respiratory activities of Rhizoctonia solani treated by SYP-14288. Wild-type strains and SYP-14288-resistant mutants of R. solani were incubated on potato dextrose agar amended with either SYP-14288 or one of select fungicides acting on fungal respiration, including complex I, II, and III inhibitors; uncouplers; and ATP synthase inhibitors. Mycelial growth was measured under fungicides treatments. ATP content was determined using an ATP assay kit, membrane potential of mitochondria was detected with the JC-1 kit, and respiratory rate was calculated based on the measurement of oxygen consumption of R. solani. A model of metabolic fingerprinting cluster was established to separate oxidation inhibitors and phosphorylation inhibitors. All the results together displayed a clear discrimination between oxidation inhibitors and phosphorylation inhibitors, and the latter inhibited ATP synthase production having or uncoupling activities. Based on the model, SYP-14288 was placed in phosphorylation inhibitor group, because it significantly reduced ATP content and membrane potential of mitochondria while increasing respiratory rate in R. solani. Therefore, the MoA of SYP-14288 on R. solani was confirmed to involve phosphorylation inhibition and possibly uncoupling activity.

2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Victor Jeger ◽  
Sebastian Brandt ◽  
Francesca Porta ◽  
Stephan M. Jakob ◽  
Jukka Takala ◽  
...  

Introduction.Results on mitochondrial dysfunction in sepsis are controversial. We aimed to assess effects of LPS at wide dose and time ranges on hepatocytes and isolated skeletal muscle mitochondria.Methods.Human hepatocellular carcinoma cells (HepG2) were exposed to placebo or LPS (0.1, 1, and 10 μg/mL) for 4, 8, 16, and 24 hours and primary human hepatocytes to 1 μg/mL LPS or placebo (4, 8, and 16 hours). Mitochondria from porcine skeletal muscle samples were exposed to increasing doses of LPS (0.1–100 μg/mg) for 2 and 4 hours. Respiration rates of intact and permeabilized cells and isolated mitochondria were measured by high-resolution respirometry.Results.In HepG2 cells, LPS reduced mitochondrial membrane potential and cellular ATP content but did not modify basal respiration. Stimulated complex II respiration was reduced time-dependently using 1 μg/mL LPS. In primary human hepatocytes, stimulated mitochondrial complex II respiration was reduced time-dependently using 1 μg/mL LPS. In isolated porcine skeletal muscle mitochondria, stimulated respiration decreased at high doses (50 and 100 μg/mL LPS).Conclusion.LPS reduced cellular ATP content of HepG2 cells, most likely as a result of the induced decrease in membrane potential. LPS decreased cellular and isolated mitochondrial respiration in a time-dependent, dose-dependent and complex-dependent manner.


2009 ◽  
Vol 53 (8) ◽  
pp. 3595-3598 ◽  
Author(s):  
Sikder M. Asaduzzaman ◽  
Jun-ichi Nagao ◽  
Hiroshi Iida ◽  
Takeshi Zendo ◽  
Jiro Nakayama ◽  
...  

ABSTRACT We determined the mode of action of nukacin ISK-1. It did not cause membrane potential dissipation or the efflux of ATP or K+ ions from the cells of a sensitive bacterial strain; however, it blocked the membrane depolarization activity of nisin. Nukacin ISK-1-treated cells had single arrangements of cells without the formation of a complete septum. A remarkable reduction in cell wall width was also observed, but cytoplasmic content was unaffected. We concluded that nukacin ISK-1 is bacteriostatic.


1978 ◽  
Vol 88 (11) ◽  
pp. 1825???1835 ◽  
Author(s):  
DANIEL C. MARCUS ◽  
RUEDIGER THALMANN ◽  
NANCY Y. MARCUS

2010 ◽  
Vol 58 (5) ◽  
pp. 2726-2729 ◽  
Author(s):  
Xiaojing Yan ◽  
Xiaomei Liang ◽  
Shuhui Jin ◽  
Jinping Lv ◽  
Chunxin Yu ◽  
...  

Insects ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 333 ◽  
Author(s):  
Éva Kolics ◽  
Kinga Mátyás ◽  
János Taller ◽  
András Specziár ◽  
Balázs Kolics

Lithium chemicals have been proven to be very effective in eradicating Varroa destructor, the detrimental parasite of the honey bee; however, little is known about the side effects on brood and long term consequences on the colony. Earlier, it was proposed that the action mechanisms of lithium chloride do not include the contact mode. Here, we investigate this question using a paper strip test to demonstrate the concentration-dependent effectiveness of lithium in the contact mode of action, confirming that it is also a contact agent against the Varroa mite. According to our knowledge, this is the first report on the high varroicidal effect of lithium in the contact mode of action. Our findings may open up possibilities for novel ways of treatment (e.g., the use of lithiated strips) in the event that lithium salts become legal for use in apiculture.


2019 ◽  
Vol 2019 ◽  
pp. 1-19 ◽  
Author(s):  
Huiqin Luo ◽  
Shu Song ◽  
Yun Chen ◽  
Mengting Xu ◽  
Linlin Sun ◽  
...  

Ca2+/calmodulin-dependent protein kinase II (CaMKII), regulated by inhibitor 1 of protein phosphatase 1 (I1PP1), is vital for maintaining cardiovascular homeostasis. However, the role and mechanism of I1PP1 against hypoxia-reoxygenation (H/R) injury in cardiomyocytes remain a question. In our study, after I1PP1 overexpression by adenovirus infection in the neonatal cardiomyocytes followed by hypoxia for 4 h and reoxygenation for 12 h, the CaMKIIδ alternative splicing subtype, ATP content, and lactate dehydrogenase (LDH) release were determined. CaMKII activity was evaluated by phosphoprotein phosphorylation at Thr17 (p-PLB Thr17), CaMKII phosphorylation (p-CaMKII), and CaMKII oxidation (ox-CaMKII). Reactive oxygen species (ROS), mitochondrial membrane potential, dynamin-related protein 1 (DRP1), and optic atrophy 1 (OPA1) expressions were assessed. Our study verified that I1PP1 overexpression attenuated the CaMKIIδ alternative splicing disorder; suppressed PLB phosphorylation at Thr17, p-CaMKII, and ox-CaMKII; decreased cell LDH release; increased ATP content; attenuated ROS production; increased mitochondrial membrane potential; and decreased DRP1 expression but increased OPA1 expression in the cardiomyocytes after H/R. Contrarily, CaMKIIδ alternative splicing disorder, LDH release, ATP reduction, and ROS accumulation were aggravated after H/R injury with the I1PP1 knockdown. Collectively, I1PP1 overexpression corrected disorders of CaMKIIδ alternative splicing, inhibited CaMKII phosphorylation, repressed CaMKII oxidation, suppressed ROS production, and attenuated cardiomyocyte H/R injury.


2015 ◽  
Vol 27 (1) ◽  
pp. 232
Author(s):  
D. Dadarwal ◽  
F. Dias ◽  
G. Adams ◽  
J. Singh

Our objective was to determine how follicular aging affects the distribution and content of mitochondrial population and ATP in in vivo-matured bovine oocytes. We hypothesised that in vivo-matured bovine oocytes obtained from aged follicles (84 h of gonadotropin starvation) have altered mitochondrial distribution and decreased cytoplasmic ATP content compared to those obtained immediately at the end of a superstimulatory protocol (no starvation). Follicular waves were synchronized by ablation 5 to 8 d after ovulation and a CIDR device was given. Starting on the day of wave emergence (Day 0), short FSH and FSH starvation groups (n = 5 heifers each) were given 8 doses of FSH im over 4 d and the long FSH group (n = 4) was given 14 doses over 7 d. Two doses of PGF were given on Day 4 (short FSH) or Day 7 (FSH starvation and long FSH groups), the CIDR was removed, and LH was given 24 h after second PGF treatment. The ovaries were removed 24 h later by colpotomy and cumulus-oocyte-complexes (COC) were collected from follicles ≥8 mm. Denuded oocytes were either stained with Mitotracker Deep Red FM and imaged by confocal microscopy or processed for ATP assay. Mitochondria numbers were assessed by segmentation of 3D datasets. Proportions of COC within each grade were compared using Fischer's exact test, and ATP and mitochondrial data were compared by analysis of variance. Short and long FSH groups had a greater proportion of Grade 1 expanded COC than the FSH starvation group (P = 0.02). The ATP content of oocytes (from expanded COC) tended to be higher in the long FSH group than short FSH (P = 0.09), and the FSH starvation group was intermediate. The ATP content of oocytes from compact COC did not differ among groups (P = 0.49). The proportion of mitochondrial clusters was highest (P = 0.01) and the proportion of individual mitochondria was lowest (P = 0.01) in the FSH starvation group compared to short and long FSH groups. Mitochondria from the long FSH and FSH starvation groups had twice the relative intensity compared to the short FSH group (P < 0.01). In conclusion, follicular aging (FSH starvation) was associated with a decrease in oocyte morphologic grade and marked clustering of mitochondria, which may be a reflection of oxidative stress and atresia.


Endocrinology ◽  
2007 ◽  
Vol 148 (5) ◽  
pp. 2037-2044 ◽  
Author(s):  
John J. Peluso ◽  
Xiufang Liu ◽  
Jonathan Romak

The present studies were designed to 1) describe changes in both the mitochondrial membrane potential and ATP content of spontaneously immortalized granulosa cells as they undergo apoptosis, 2) identify some of the downstream events that are activated by progesterone (P4), and 3) relate these downstream events to changes in mitochondrial function and apoptotic cell death. These studies revealed that in response to serum deprivation, the mitochondrial membrane potential initially hyperpolarizes and ATP content increases. That this increase in ATP is required for apoptosis was demonstrated by the finding that oligomycin inhibited the increase in ATP and apoptosis. Piridoxalphosphate-6-azopeyl-2′-4′-disulfonic acid, an inhibitor of purinergic receptors, which are activated by ATP, also inhibited apoptosis due to serum withdrawal. This study provides additional support for ATP’s causative role in apoptosis. Moreover, 8-Br-cGMP, a protein kinase G (PKG) activator, mimicked P4’s action, whereas a PKG antagonist, DT-3, attenuated P4’s suppressive effect on ATP and apoptosis. Finally, DT-3 treatment was shown to attenuate P4-regulated phosphorylation of 14-3-3σ and its binding partner, ATP synthaseβ/precursor and the amount of ATP synthaseβ/precursor that bound to 14-3-3σ. Based on these data, it is proposed that P4 prevents apoptosis in part by activating PKG, which in turn maintains the interaction between ATP synthaseβ/precursor and 14-3-3σ. In the absence of P4-induced PKG activity, we further propose that some ATP synthaseβ precursor dissociates from 14-3-3σ, resulting in its activation and incorporation into the ATP synthase complex, which ultimately results in an increase in ATP and apoptosis.


1983 ◽  
Vol 212 (1) ◽  
pp. 105-112 ◽  
Author(s):  
S Ahmed ◽  
I R Booth

Valinomycin, nigericin and trichlorocarbanilide were assessed for their ability to control the protonmotive force in Escherichia coli cells. Valinomycin, at high K+ concentrations, was found to decrease the membrane potential delta phi and indirectly to decrease the pH gradient delta pH. Nigericin was found to have two modes of action. At low concentrations (0.05-2 microM) it carried out K+/H+ exchange and decreased delta pH. At higher concentrations (50 microM) it carried out a K+-dependent transfer of H+, decreasing both delta phi and delta pH. In EDTA-treated cells only the latter mode of action was evident, whereas in a mutant sensitive to deoxycholate both types of effect were observed. Trichlorocarbanilide is proposed as an alternative to nigericin for the specific control of delta pH, and it can be used in cells not treated with EDTA.


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