direct inhibitory effect
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2021 ◽  
Vol 12 ◽  
Author(s):  
Lei Kan ◽  
Qicong Liao ◽  
Zhipeng Chen ◽  
Shuyu Wang ◽  
Yifei Ma ◽  
...  

The wild population of Madhuca pasquieri (Dubard) H. J. Lam is currently dwindling; its understory seedlings are rare, and there is a lack of molecular studies, which impedes the conservation of this species. This study exploited second-generation sequencing and widely targeted metabolomics analysis to uncover the dynamic changes in differentially expressed genes (DEGs) and differentially accumulated metabolites (DAMs) in five post-germination stages of M. pasquieri whole organism. Notably, the weighted gene co-expression network analysis (WGCNA), transcriptome, and metabolome association analyses all indicated significant enrichment of the flavonoid biosynthesis pathway in stage 4 (two-leaf), and an upregulation of the genes encoding flavonol biosynthesis in this stage. In stage 5 (nine-leaf), the flavonols were significantly accumulated, indicating that the changes in metabolites were driven at the transcript level. According to the significant changes in gene expression encoding auxin transport carriers and their correlation with flavonols during stage 5, the flavonols were speculated to have a direct inhibitory effect on the expression of PIN4 encoding gene, which may inhibit the process of polar auxin transport. The results provided important insights into the molecular network relationships between the transcription and metabolism of this rare and endangered species during the post-germination stages and explained the reasons for the slow growth of its seedlings at the molecular level.


SLEEP ◽  
2021 ◽  
Vol 44 (Supplement_2) ◽  
pp. A27-A28
Author(s):  
Roberto De Luca ◽  
Stefano Nardone ◽  
Lin Zhu ◽  
Elda Arrigoni

Abstract Introduction The ventrolateral preoptic (VLPO) nucleus is a key area involved in the initiation and maintenance of sleep. During wakefulness, sleep-promoting galanin neurons in the VLPO are directly inhibited by arousal signals including noradrenaline and acetylcholine. We have found that while these neurotransmitters directly inhibit VLPO galanin neurons, they also activate GABAergic neurons in the VLPO that do not express galanin. We propose that when activated by monoaminergic and cholinergic inputs, these local VLPO GABAergic neurons provide an additional inhibition of the VLPO galanin sleep-promoting neurons. We tested this model in brain slices in mice. Methods We studied VLPO galanin neurons in mouse brain slices using patch-clamp recordings. We recorded from fluorescently labeled VLPO galanin neurons following the injection of a cre-dependent AAV encoding for mCherry, into the VLPO of Gal-cre mice. For the optogenetic studies we expressed channelrhodopsin-2 (ChR-2) in VLPO VGAT neurons and mCherry in galanin neurons by injecting a flp-dependent and a cre-dependent AAV encoding respectively for ChR2 and mCherry into the VLPO of VGAT-flp::Gal-cre mice. We photo-stimulated local GABAergic neurons and recorded from labeled VLPO galanin neurons. Noradrenaline, carbachol and receptor antagonists were bath-applied. Results Noradrenaline and carbachol inhibited VLPO galanin neurons by alpha-2 and muscarinic receptors and these effects were maintained in the presence of tetrodotoxin (TTX) indicating, as previously proposed, a direct inhibitory effect of noradrenaline and carbachol on VLPO galanin neurons. In addition, both noradrenaline and carbachol increased the frequency of spontaneous inhibitory post-synaptic currents (sIPSCs) of VLPO galanin neurons, suggesting an additional inhibitory action on VLPO galanin neurons. Finally, optogenetic stimulation of local VLPO GABAergic neurons produced short latency, TTX-resistant, opto-evoked IPSCs in VLPO galanin neurons. Both noradrenaline and carbachol increased the amplitude of these opto-evoked IPSCs by the activation of alpha-1 and muscarinic receptors. Conclusion Our results demonstrate that noradrenaline and acetylcholine inhibit VLPO galanin neurons directly and indirectly. Both noradrenaline and acetylcholine increase GABAergic afferent inputs to VLPO galanin neurons by activating local GABAergic neurons. We propose that during wakefulness this feedforward inhibition provides additional inhibition of VLPO galanin sleep-promoting neurons. Support (if any) NS091126 and HL149630


2020 ◽  
Author(s):  
Xiaohong Du ◽  
Xiangyang Zuo ◽  
Fang Meng ◽  
Chenfeng Han ◽  
Wei Ouyang ◽  
...  

2020 ◽  
Vol 88 (12) ◽  
Author(s):  
Zachary P. Howard ◽  
Anders Omsland

ABSTRACT Coxiella burnetii is a zoonotic bacterial obligate intracellular parasite and the cause of query (Q) fever. During natural infection of female animals, C. burnetii shows tropism for the placenta and is associated with late-term abortion, at which time the pathogen titer in placental tissue can exceed one billion bacteria per gram. During later stages of pregnancy, placental trophoblasts serve as the major source of progesterone, a steroid hormone known to affect the replication of some pathogens. During infection of placenta-derived JEG-3 cells, C. burnetii showed sensitivity to progesterone but not the immediate precursor pregnenolone or estrogen, another major mammalian steroid hormone. Using host cell-free culture, progesterone was determined to have a direct inhibitory effect on C. burnetii replication. Synergy between the inhibitory effect of progesterone and the efflux pump inhibitors verapamil and 1-(1-naphthylmethyl)-piperazine is consistent with a role for efflux pumps in preventing progesterone-mediated inhibition of C. burnetii activity. The sensitivity of C. burnetii to progesterone, but not structurally related molecules, is consistent with the ability of progesterone to influence pathogen replication in progesterone-producing tissues.


2020 ◽  
Vol 49 (2) ◽  
pp. 135-143
Author(s):  
C.H. Li ◽  
M.Y. Du ◽  
K.T. Wang

This study was conducted to assess the effects of 2,4-epibrassionolide (EBR) on mold decay caused by Rhizopus stolonifer and its capability to activate biochemical defense reactions in postharvest peaches. The treatment of EBR at 5 μM possessed the optimum effectiveness on inhibiting the Rhizopus rot in peach fruit among all treatments. The EBR treatment significantly up-regulated the expression levels of a set of defense-related enzymes and PR genes that included PpCHI, PpGns1, PpPAL, PpNPR1, PpPR1 and PpPR4 as well as led to an enhancement for biosynthesis of phenolics and lignins in peaches during the incubation at 20 °C. Interestingly, the EBR-treated peaches exhibited more striking expressions of PR genes and accumulation of antifungal compounds upon inoculation with the pathogen, indicating a priming defense could be activated by EBR. On the other hand, 5 μM EBR exhibited direct toxicity on fungal proliferation of R. stolonifer in vitro. Thus, we concluded that 5 μM EBR inhibited the Rhizopus rot in peach fruit probably by a direct inhibitory effect on pathogen growth and an indirect induction of a priming resistance. These findings provided a potential alternative for control of fungal infection in peaches during the postharvest storage.


2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Weiran Zheng ◽  
Meng Li ◽  
Yongxiang Wang ◽  
Baojie Lv ◽  
Xinzhuang Zhang ◽  
...  

Guizhi Fuling capsule (GZFLc) is a modern preparation from traditional Chinese Medicine. Guizhi Fuling was first prescribed by Zhang Zhongjing almost two thousand years ago for the treatment of primary dysmenorrhea. It has also been used to treat uterine fibroids, dysfunctional uterine bleeding, and endometriosis. Although effective against dysmenorrhea clinically, there are limited information on the mechanism of its action. The major components responsible for the activity are not well defined. The aim of this study has been to elucidate a mechanism that may facilitate the development of a bioactivity-based assay for quality control during drug formulation and manufacturing. Using an oxytocin-induced mouse dysmenorrhea model, we showed that oral administration of GZFLc at 150 and 300 mg/kg, dosages relevant to clinic usages, significantly suppressed oxytocin-induced writhing response. The antidysmenorrhea effect was also demonstrated by a rotarod assay. We showed that GZFLc treatment significantly prolonged the hanging time of mice on the rotating rod. Histological studies showed that GZFLc treatment reduced lamina propria edema, while no effect on COX2 expression was detected. GZFLc instead exhibited direct inhibitory effect against COX2, a critical enzyme that catalyzes arachidonic acid conversion to prostaglandins. By HPLC profiling, we showed that paeoniflorin, paeonol, and cinnamaldehyde are the major components from the corresponding plants. At 5 and 10 mg/kg, both paeoniflorin and paeonol were active against induced dysmenorrhea. The study not only links GZFLc antidysmenorrhea activity to COX2 inhibition but also uncovers a mechanism of action by which an assay can be developed for bioefficacy evaluation of GZFLc.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Matej Par ◽  
Nika Spanovic ◽  
Tobias T. Tauböck ◽  
Thomas Attin ◽  
Zrinka Tarle

AbstractResin composites containing reinforcing inert glass fillers combined with bioactive glass (BG) can aid in the prevention of secondary caries, which is a major cause of failure of contemporary composite restorations. A series of previous studies on experimental resin composites filled with BG 45S5 has demonstrated that methacrylate resin polymerization can be impaired by the addition of unsilanized BG, leading to lower degrees of conversion (DC). In order to distinguish whether the polymerization inhibition is caused by a direct (temperature-independent) effect of BG or an indirect (temperature-dependent) effect of restricted mobility of reactive species, this study used Raman spectroscopy to evaluate the DC values of experimental composites post-cured at 37 °C and 150 °C. The potential of BG to adversely affect DC was highly dependent on the resin system. The highest DC reduction was observed in the resin system based on ethoxylated bisphenol A dimethacrylate (Bis-EMA), followed by bisphenol A glycidyl methacrylate (Bis-GMA). In contrast, the DC for urethane dimethacrylate (UDMA) was not compromised by BG. Increasing the mobility of reactive species by heating at 150 °C showed limited potential for increasing the DC in the Bis-EMA and Bis-GMA resin systems, indicating a direct inhibitory effect of BG on polymerization.


2019 ◽  
Vol 44 (5) ◽  
pp. 507-511
Author(s):  
Aneta Štochmal’ová ◽  
Abdel Halim Harrath ◽  
Saleh Alwasel ◽  
Alexander V. Sirotkin

Flaxseed is useful as a functional food and alternative medicine owing to its beneficial health effects. Its action on ovarian cell functions and interrelationships with the upstream hormonal regulators remain unknown. Our aim was to examine the direct influence of flaxseed extract on basal porcine ovarian functions (proliferation, apoptosis), leptin release, and response to insulin-like growth factor I (IGF-I). First, we examined the effect of flaxseed extract on the accumulation of proliferation (PCNA) and apoptosis (Bax) markers and on leptin release in cultured porcine ovarian granulosa cells. Next, granulosa cells were cultured with IGF-I with and without flaxseed extract and analyzed for PCNA and Bax accumulation by quantitative immunocytochemistry and for leptin release by radioimmunoassay. Flaxseed decreased the accumulation of PCNA and increased that of Bax at all doses and reduced leptin output at 100 μg/mL. In contrast, IGF-I promoted PCNA accumulation and suppressed Bax. Flaxseed did not modify IGF-I action on these parameters. Thus, we showed that flaxseed influences porcine reproductive processes, having a direct effect on the ovary and the ability to affect ovarian cell proliferation, apoptosis, and leptin release. Furthermore, we confirmed the pro-proliferative and antiapoptotic actions of IGF-I but showed that flaxseed action on ovarian cell proliferation and apoptosis is not due to changes in the cell response to IGF-I. The potential direct anti-reproductive action of flaxseed needs to be considered during its application in nutrition, medicine, and animal production.


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