5’-adenosine monophosphate-activated protein kinase (AMPK) modulates myoendothelial junctions

Cell-to-cell communication plays an important role in multicellular tissues. It is also pivotal in the modulation of vessel functions, such as the regulation of vessel tone. Heterocellular communication between endothelial cells (EC) and vascular smooth muscle cells (VSMC) via myoendothelial gap junctions (MEGJs) represents an important communication pathway in resistance arteries and arterioles. Myoendothelial junctions (MEJ) are, however, not only the site of direct cell communication via gap junctions but also represent a signaling microdomain critical for localizing, concentrating, and organizing cell-signaling components and regulating various vascular biological processes such as endothelium dependent hyperpolarization (EDH) of vascular smooth muscle. Therefore, a better understanding of MEJ’s physiological functions allows new insights into regulation of vessel function. Up to now, little is known, however, about the regulation for MEJ formation. The 5’-adenosine monophosphate-activated protein kinase (AMPK) is not only one of the most important enzymes controlling cell catabolic metabolism, but has been shown to influence vascular tone, thereby augmenting blood and oxygen supply as required for catabolic pathways. It has not yet been studied, however, whether AMPK could also affect MEJ. Thus, the aim of this project was to elucidate the impact of AMPK on MEJ dynamics and its potential mechanism of action. We studied isolated small mesenteric and skeletal muscle resistance arteries of mice using a pressure myograph system developed in our laboratory. Using confocal and two photon excitation fluorescence microscopy we identified the internal elastic lamina, which in these vessels exhibits small holes that allow direct contact between endothelial and smooth muscle cells. On average, we found that in about 35% of the holes, structures with a bright actin core as assessed by using F-actin fluorescence in LifeAct mice or by staining with phalloidin which we could define as sites of MEJ. These structures showed expression of Cx37 and Cx43 suggesting that MEGJs were also localized in these structures. We found that endoplasmic reticulum (ER) was enriched around MEJs which is consistent with MEJs acting as active signaling domains. Over observation time of up to 2 hours, we found that the number and localization of these MEJ varied, while they always showed expression in the area of holes of IEL only. Thus, for the first time we could investigate MEJ dynamics. AMPK negatively regulates MEJ expression, since in AMPK α1, but not in α2 knockout (KO) mice, the number of MEJ was significantly increased. In accordance, in wild type mice, incubation with the AMPK inhibitory compound C (CC) significantly augmented the number of MEJ while the AMPK stimulator A76 did not further decrease them during the observation time. Furthermore, we found that the KO of AMPK α1, in intact mice as well as in cultured human and porcine smooth muscle cells, went along with an increase in PAI-1 expression. Accordingly, incubation of arteries with exogenous PAI-1 also increased the number of MEJ. The negative effect of AMPK on PAI-1 could be explained by enhanced expression of the silencer of the PAI-1 gene, small heterodimer partner (SHP). PAI-1 expression in arteries from AMPK α2 KO mice was unchanged compared to arteries from WT mice. Since MEJ are also involved in EDH, we studied whether the expression of MEJ correlated with EDH induced vasodilation. The higher amount of MEJs in α1 KO mice went indeed along with a left shift of acetylcholine (ACh) -induced dilation dose effect curve. In summary, this work describes for the first time a role of AMPK as a potent modulator of MEJ dynamics. This effect is selectively mediated by the α1 subunit of AMPK which is probably mediated by controlling PAI-1 expression. Our data also for the first time demonstrate a dynamic regulation of MEJ expression in intact blood vessels. Since MEJ represent a gateway for the communication between EC and VSMC and are involved in EDH, our observations may point towards a new target with therapeutic potential in small resistance vessels

5’-adenosine monophosphate-activated protein kinase (AMPK) modulates myoendothelial junctions

Cell-to-cell communication plays an important role in multicellular tissues. It is also pivotal in the modulation of vessel functions, such as the regulation of vessel tone. Heterocellular communication between endothelial cells (EC) and vascular smooth muscle cells (VSMC) via myoendothelial gap junctions (MEGJs) represents an important communication pathway in resistance arteries and arterioles. Myoendothelial junctions (MEJ) are, however, not only the site of direct cell communication via gap junctions but also represent a signaling microdomain critical for localizing, concentrating, and organizing cell-signaling components and regulating various vascular biological processes such as endothelium dependent hyperpolarization (EDH) of vascular smooth muscle. Therefore, a better understanding of MEJ’s physiological functions allows new insights into regulation of vessel function. Up to now, little is known, however, about the regulation for MEJ formation. The 5’-adenosine monophosphate-activated protein kinase (AMPK) is not only one of the most important enzymes controlling cell catabolic metabolism, but has been shown to influence vascular tone, thereby augmenting blood and oxygen supply as required for catabolic pathways. It has not yet been studied, however, whether AMPK could also affect MEJ. Thus, the aim of this project was to elucidate the impact of AMPK on MEJ dynamics and its potential mechanism of action. We studied isolated small mesenteric and skeletal muscle resistance arteries of mice using a pressure myograph system developed in our laboratory. Using confocal and two photon excitation fluorescence microscopy we identified the internal elastic lamina, which in these vessels exhibits small holes that allow direct contact between endothelial and smooth muscle cells. On average, we found that in about 35% of the holes, structures with a bright actin core as assessed by using F-actin fluorescence in LifeAct mice or by staining with phalloidin which we could define as sites of MEJ. These structures showed expression of Cx37 and Cx43 suggesting that MEGJs were also localized in these structures. We found that endoplasmic reticulum (ER) was enriched around MEJs which is consistent with MEJs acting as active signaling domains. Over observation time of up to 2 hours, we found that the number and localization of these MEJ varied, while they always showed expression in the area of holes of IEL only. Thus, for the first time we could investigate MEJ dynamics. AMPK negatively regulates MEJ expression, since in AMPK α1, but not in α2 knockout (KO) mice, the number of MEJ was significantly increased. In accordance, in wild type mice, incubation with the AMPK inhibitory compound C (CC) significantly augmented the number of MEJ while the AMPK stimulator A76 did not further decrease them during the observation time. Furthermore, we found that the KO of AMPK α1, in intact mice as well as in cultured human and porcine smooth muscle cells, went along with an increase in PAI-1 expression. Accordingly, incubation of arteries with exogenous PAI-1 also increased the number of MEJ. The negative effect of AMPK on PAI-1 could be explained by enhanced expression of the silencer of the PAI-1 gene, small heterodimer partner (SHP). PAI-1 expression in arteries from AMPK α2 KO mice was unchanged compared to arteries from WT mice. Since MEJ are also involved in EDH, we studied whether the expression of MEJ correlated with EDH induced vasodilation. The higher amount of MEJs in α1 KO mice went indeed along with a left shift of acetylcholine (ACh) -induced dilation dose effect curve. In summary, this work describes for the first time a role of AMPK as a potent modulator of MEJ dynamics. This effect is selectively mediated by the α1 subunit of AMPK which is probably mediated by controlling PAI-1 expression. Our data also for the first time demonstrate a dynamic regulation of MEJ expression in intact blood vessels. Since MEJ represent a gateway for the communication between EC and VSMC and are involved in EDH, our observations may point towards a new target with therapeutic potential in small resistance vessels

Media Literasi: Upaya Bijak Menyikapi Terpaan Tayangan Televisi

The television media have transformed into industry. Tight competition among TV stations demands the media people to provide programs based on the market taste. Therefore, mostly TV stations design and produce their programs based on share and rating numbers, instead of quality. On the other side, TV stations have important roles in constructing social and cultural development. Currently, TV programs are merely produced based on the business orientation so that the quality of the TV programs is often ignored. Audience must be wise and smart to protect themselves from poor-quality TV programs exposure. This can be achieved by improving their Media Literacy. In the end, Audience is no longer treated as passive object, but actively takes control on the content selection

Every Coin Has Two Sides: Reactive Oxygen Species during Rice–Magnaporthe oryzae Interaction

Reactive oxygen species (ROS) are involved in many important processes, including the growth, development, and responses to the environments, in rice (Oryza sativa) and Magnaporthe oryzae. Although ROS are known to be critical components in rice–M. oryzae interactions, their regulations and pathways have not yet been completely revealed. Recent studies have provided fascinating insights into the intricate physiological redox balance in rice–M. oryzae interactions. In M. oryzae, ROS accumulation is required for the appressorium formation and penetration. However, once inside the rice cells, M. oryzae must scavenge the host-derived ROS to spread invasive hyphae. On the other side, ROS play key roles in rice against M. oryzae. It has been known that, upon perception of M. oryzae, rice plants modulate their activities of ROS generating and scavenging enzymes, mainly on NADPH oxidase OsRbohB, by different signaling pathways to accumulate ROS against rice blast. By contrast, the M. oryzae virulent strains are capable of suppressing ROS accumulation and attenuating rice blast resistance by the secretion of effectors, such as AvrPii and AvrPiz-t. These results suggest that ROS generation and scavenging of ROS are tightly controlled by different pathways in both M. oryzae and rice during rice blast. In this review, the most recent advances in the understanding of the regulatory mechanisms of ROS accumulation and signaling during rice–M. oryzae interaction are summarized

Safety and Feasibility Study of a Novel Stent-Graft for Thoracic Endovascular Aortic Repair: a Canine Model Experiment

Abstract Objective: To evaluate the safety and feasibility of a novel stent-graft for thoracic endovascular aortic repair (TEVAR) in a canine model, 9 adult hybrid dogs were used for the experiment. Methods: All animals were implanted with a novel thoracic aortic stent-graft via femoral artery. Blood sample was collected at pre-operation and 1, 2, 4, 8 and 12 weeks after implantation for hematological examination. Moreover, tissues from randomly selected 4 dogs were subjected to histopathological analysis with the optical microscope after stent-grafts were implanted for 3, 6, 9, and 12 months respectively. The experimental period lasted for more than 2 years. Results: A total of 9 stent-grafts were successfully implanted in the canine thoracic aortas and no migration or deformation occurred. Related indicators of blood routine, inflammatory factors, and immunology changes were not significantly (P>0.05), except the white blood cell (WBC) counts in the first week. Moreover, abnormal morphology was not found in all thoracic aortas via histopathological examination. Additionally, all stent-grafts were patent and did not migrate, and there was no thrombus in the lumens of stent-grafts. Conclusion: The novel thoracic aortic stent-graft made in China was safe and feasible for thoracic endovascular aortic repair in a canine model

Antifungal mechanisms of silver nanoparticles on mycotoxin producing rice false smut fungus

Summary: Ustilaginoidea virens, which causes rice false smut disease, is a destructive filamentous fungal pathogen, attracting more attention to search for effective fungicides against U. virens. Here, the results showed that the inhibition of 2 nm AgNPs on U. virens growth and virulence displayed concentration-dependent manner. Abnormalities of fungal morphology were observed upon exposure to AgNPs. RNA-sequencing (RNA-seq) analysis revealed that AgNPs treatment up-regulated 1185 genes and down-regulated 937 genes, which significantly overlapped with the methyltransferase UvKmt6-regulated genes. Furthermore, we found that AgNPs reduced the UvKmt6-mediated H3K27me3 modification, resulting in the up-regulation of ustilaginoidin biosynthetic genes The decrease of H3K27me3 level was associated with the inhibition of mycelial growth by AgNPs treatment. These results suggested that AgNPs are an effective nano-fungicide for the control of rice false smut disease, but when using AgNPs, it needs to be combined with mycotoxin-reducing fungicides to reduce the risk of toxin pollution

Recent Progress in Rice Broad-Spectrum Disease Resistance

Rice is one of the most important food crops in the world. However, stable rice production is constrained by various diseases, in particular rice blast, sheath blight, bacterial blight, and virus diseases. Breeding and cultivation of resistant rice varieties is the most effective method to control the infection of pathogens. Exploitation and utilization of the genetic determinants of broad-spectrum resistance represent a desired way to improve the resistance of susceptible rice varieties. Recently, researchers have focused on the identification of rice broad-spectrum disease resistance genes, which include R genes, defense-regulator genes, and quantitative trait loci (QTL) against two or more pathogen species or many isolates of the same pathogen species. The cloning of broad-spectrum disease resistance genes and understanding their underlying mechanisms not only provide new genetic resources for breeding broad-spectrum rice varieties, but also promote the development of new disease resistance breeding strategies, such as editing susceptibility and executor R genes. In this review, the most recent advances in the identification of broad-spectrum disease resistance genes in rice and their application in crop improvement through biotechnology approaches during the past 10 years are summarized

Carbon Catabolite Repressor UvCreA is Required for Development and Pathogenicity in Ustilaginoidea virens

The rice false smut disease, caused by Ustilaginoidea virens, has emerged as a significant global threat to rice production. The mechanism of carbon catabolite repression plays a crucial role in the efficient utilization of carbon nutrients and enzyme regulation in the presence of complex nutritional conditions. Although significant progress has been made in understanding carbon catabolite repression in fungi such as Aspergillus nidulans and Magnaporthe oryzae, its role in U. virens remains unclear. To address this knowledge gap, we identified UvCreA, a pivotal component of carbon catabolite repression, in U. virens. Our investigation revealed that UvCreA localized to the nucleus. Deletion of UvCreA resulted in decreased growth and pathogenicity in U. virens. Through RNA-seq analysis, it was found that the knockout of UvCreA led to the up-regulation of 514 genes and down-regulation of 640 genes. Moreover, UvCreA was found to be involved in the transcriptional regulation of pathogenic genes and genes associated with carbon metabolism in U. virens. In summary, our findings indicated that UvCreA is important in fungal development, virulence, and the utilization of carbon sources through transcriptional regulation, thus making it a critical element of carbon catabolite repression

Sucrose non-fermenting protein kinase gene UvSnf1 is required for virulence in Ustilaginoidea virens

ABSTRACTRice false smut caused by Ustilaginoidea virens is becoming one of the most devastating diseases in rice production areas in the world. Revealing U. virens potential pathogenic mechanisms provides ideas for formulating more effective prevention and control strategies. Sucrose non-fermenting 1 (Snf1) protein kinase plays a critical role in activating transcription and suppressing gene expression, as well as in cellular response to various stresses, such as nutrient limitation. In our study, we identified the Snf1 homolog UvSnf1 and analyzed its biological functions in U. virens. The expression level of UvSnf1 was dramatically up-regulated during invasion, indicating that UvSnf1 may participate in infection. Phenotypic analyses of UvSnf1 deletion mutants revealed that UvSnf1 is necessary for hyphae growth, spore production, and virulence in U. virens. Moreover, UvSnf1 promotes U. virens to use unfavorable carbon sources when the sucrose is insufficient. In addition, deletion of UvSnf1 down-regulates the expression of the cell wall-degrading enzymes (CWDEs) genes under sucrose limitation conditions in U. virens. Further analyses showed that CWDEs (UvCut1 and UvXyp1) are not only involved in growth, spore production, and virulence but are also required for the utilization of carbon sources. In conclusion, this study demonstrates that UvSnf1 plays vital roles in virulence and carbon source utilization in U. virens, and one of the possible mechanisms is playing a role in regulating the expression of CWDE genes