Potato miR394 targets StA/N-INVE and StLCR to negatively regulate late blight resistance.

MicroRNAs (miRNAs) are small noncoding RNAs in eukaryotes. Plant endogenous miRNAs play pivotal roles in regulating plant development and defense responses. MicroRNA394 (miR394) has been reported to regulate plant development, abiotic stresses and defense responses. Previous reports showed that miR394 responded to P. infestans inoculation in potato, indicating that miR394 may be involved in defense responses. In this study, we further investigated its role in potato defense against P. infestans. Stable expression of miR394 in tobacco and potato enhances the susceptibility to P. infestans, which is accompanied with the reduced accumulation of ROS and down-regulation of the PTI (pattern-triggered immunity) marker genes. Besides well-known target StLCR, miR394 also targets StA/N-INVE, which encodes a chloroplast Alkaline/Neutral Invertases (A/N-INVE). Both StLCR and StA/N-INVE positively regulate late blight resistance, while miR394 degrades them. Interestingly, StA/N-INVE is located in the chloroplast, indicating that miR394 may manipulate chloroplast immunity. Degradation of StA/N-INVE may affect the chloroplast function and hence lead to the compromised ROS (reactive oxygen species) burst and reduced retrograde signaling from the chloroplast to the nucleus and cytoplasm. In summary, this study provides new information that miR394 targets and degrades StA/N-INVE and StLCR, which are positive regulators, to enhance potato susceptibility to P. infestans.

New role of gramicidin A in RIG-I-like receptors-mediated IFN signalling.

The pattern recognition receptors (PRRs) sense exogenous molecular patterns most commonly derived from invading pathogens, to active the interferon (IFN) signalling. In the cytoplasm, the viral double-stranded RNAs (dsRNAs) are sensed by retinoic acid-inducible gene I (RIG-I) or melanoma differentiation-associated protein 5 (MDA5), depending on the length and chemical properties. Through the binding and oligomerizing onto the RNAs, they form filament to initiate the signalling cascade. Regulation of these receptors' activities are essential for manipulating the strength of IFN signalling. Here, through the virtual screening of chemical reagents using the published MDA5-dsRNA complex structure (PDB: 4GL2), we identified an antibiotic, gramicidin A as a stimulator that enhanced MDA5-mediated IFN signalling. Cytotoxic assay and IFN signalling assay suggested that disruption of lipid membrane, which is a well-defined mechanism of gramicidin A to perform its action, was dispensable in this process. Sucrose gradient ultracentrifugation assay showed that the gramicidin A treatment enhanced MDA5 oligomerization status in the presence of dsRNA. Our work implicated a new role of gramicidin A in innate immunity and presented a new tool to manipulate MDA5 activity.

Recent Progress of Remediating Heavy Metal Contaminated Soil Using Layered Double Hydroxides as Super-Stable Mineralizer.

Heavy metal contamination in soil, which is harmful to both ecosystem and mankind, has attracted worldwide attention from the academic and industrial communities. However, the most-widely used remediation technologies such as electrochemistry, elution, and phytoremediation. suffer from either secondary pollution, long cycle time or high cost. In contrast, in situ mineralization technology shows great potential due to its universality, durability and economical efficiency. As such, the development of mineralizers with both high efficiency and low-cost is the core of in situmineralization. In 2021, the concept of 'Super-Stable Mineralization' was proposed for the first time by Kong et al.[1] The layered double hydroxides (denoted as LDHs), with the unique host-guest intercalated structure and multiple interactions between the host laminate and the guest anions, are considered as an ideal class of materials for super-stable mineralization. In this review, we systematically summarize the application of LDHs in the treatment of heavy metal contaminated soil from the view of: 1) the structure-activity relationship of LDHs in in situ mineralization, 2) the advantages of LDHs in mineralizing heavy metals, 3) the scale-up preparation of LDHs-based mineralizers and 4) the practical application of LDHs in treating contaminated soil. At last, we highlight the challenges and opportunities for the rational design of LDH-based mineralizer in the future.

Cerium oxide-based nanozyme suppresses kidney calcium oxalate crystal depositions via reversing hyperoxaluria-induced oxidative stress damage.

Oxidative stress damage to renal epithelial cells is the main pathological factor of calcium oxalate calculi formation. The development of medicine that could alleviate oxidative damage has become the key to the prevention and treatment of urolithiasis. Herein, porous nanorods CeO2 nanoparticles (CNPs) were selected from CeO2 with different morphologies as an antioxidant reagent to suppress kidney calcium oxalate crystal depositions with excellent oxidation resistance due to its larger specific surface area. The reversible transformation from Ce3+ to Ce4+ could catalyze the decomposition of excess free radicals and act as a biological antioxidant enzyme basing on its strong ability to scavenge free radicals. The protection capability of CNPS against oxalate-induced damage and the effect of CNPS on calcium oxalate crystallization were studied. CNPS could effectively reduce reactive oxygen species production, restore mitochondrial membrane potential polarity, recover cell cycle progression, reduce cell death, and inhibit the formation of calcium oxalate crystals on the cell surface in vitro. The results of high-throughput sequencing of mRNA showed that CNPs could protect renal epithelial cells from oxidative stress damage caused by high oxalate by suppressing the expression gene of cell surface adhesion proteins. In addition, CNPS can significantly reduce the pathological damage of renal tubules and inhibit the deposition of calcium oxalate crystals in rat kidneys while having no significant side effect on other organs and physiological indicators in vivo. Our results provide a new strategy for CNPS as a potential for clinical prevention of crystalline kidney injury and crystal deposition.

Phytophthora infestans RXLR effector Pi04089 perturbs diverse defense-related genes to suppress host immunity.

BACKGROUND: The oomycete pathogen secretes many effectors into host cells to manipulate host defenses. For the majority of effectors, the mechanisms related to how they alter the expression of host genes and reprogram defenses are not well understood. In order to investigate the molecular mechanisms governing the influence that the Phytophthora infestans RXLR effector Pi04089 has on host immunity, a comparative transcriptome analysis was conducted on Pi04089 stable transgenic and wild-type potato plants. RESULTS: Potato plants stably expressing Pi04089 were more susceptible to P. infestans. RNA-seq analysis revealed that 658 upregulated genes and 722 downregulated genes were characterized in Pi04089 transgenic lines. A large number of genes involved in the biological process, including many defense-related genes and certain genes that respond to salicylic acid, were suppressed. Moreover, the comparative transcriptome analysis revealed that Pi04089 significantly inhibited the expression of many flg22 (a microbe-associated molecular pattern, PAMP)-inducible genes, including various Avr9/Cf-9 rapidly elicited (ACRE) genes. Four selected differentially expressed genes (StWAT1, StCEVI57, StKTI1, and StP450) were confirmed to be involved in host resistance against P. infestans when they were transiently expressed in Nicotiana benthamiana. CONCLUSION: The P. infestans effector Pi04089 was shown to suppress the expression of many resistance-related genes in potato plants. Moreover, Pi04089 was found to significantly suppress flg22-triggered defense signaling in potato plants. This research provides new insights into how an oomycete effector perturbs host immune responses at the transcriptome level.

Mechanism and effects of fructose diphosphate on anti-hypoxia fatigue and learning memory ability.

This study aims to investigate the mechanisms through which fructose diphosphate (FDP) causes anti-hypoxia and anti-fatigue effects and improves learning and memory. Mice were divided into three groups: low-dose FDP (FDP-L), high-dose FDP (FDP-H), and a control group. Acute toxic hypoxia induced by carbon monoxide, sodium nitrite, and potassium cyanide and acute cerebral ischemic hypoxia were used to investigate the anti-hypoxia ability of FDP. The tests of rod-rotating, mouse tail suspension, and swimming endurance were used to explore the anti-fatigue effects of FDP. The Morris water maze experiment was used to determine the impact of FDP on learning and memory ability. Poisoning-induced hypoxic tests showed that mouse survival time was significantly prolonged in the FDP-L and FDP-H groups compared with the control group (p < 0.05). In the exhaustive swimming test, FDP significantly shortened struggling time and prolonged the time of mass-loaded swimming; the rod-rotating test showed that endurance time was significantly prolonged by using FDP (p < 0.05). FDP significantly decreased lactate and urea nitrogen levels and increased hepatic and muscle glycogen and glucose transporter-4 and Na+-K+-ATPase (p < 0.05). To conclude, FDP enhances hypoxia tolerance and fatigue resistance and improves learning and memory ability through regulating glucose and energy metabolism.

Comparison of the adhesion and endocytosis of calcium oxalate dihydrate to HK-2 cells before and after repair by Astragalus polysaccharide.

This work investigated the effects of repairing injured renal proximal tubular epithelial (HK-2) cells by using three Astragalus polysaccharides (APS) with different molecular weights and the adhesion and endocytosis of HK-2 cells to the calcium oxalate dihydrate (COD) nanocrystals before and after repair to develop new products that can protect against kidney stones. HK-2 cells cultured in vitro were injured with 2.6 mmol/L oxalic acid to establish a damaged cell model. Three kinds of APS (APS0, APS1, and APS2 with molecular weights of 11.03, 4.72, and 2.60 kDa, respectively) were used to repair the damaged cells. The changes in the adhesion and endocytosis of 100 nm COD crystals to cells before and after the repair were detected. After the repair of HK-2 cells by the APS, the speed of wound healing of the damaged HK-2 cells increased, and the amount of phosphatidylserine (PS) ectropion decreased. In addition, the proportion of cells with adhered COD crystals decreased, whereas the proportion of cells with internalized crystals increased. As a result of the repair activity, APS can inhibit the adhesion and promote the endocytosis of COD nanocrystals to damaged cells. APS1, which had a moderate molecular weight, displayed the strongest abilities to repair the cells, inhibit adhesion, and promote endocytosis. Thus, APS, particularly APS1, may serve as potential green drugs for preventing kidney stones.

Phase Transformation of GeO2 Glass to Nanocrystals under Ambient Conditions.

Theoretically, the accomplishment of phase transformation requires sufficient energy to overcome the barriers of structure rearrangements. The transition of an amorphous structure to a crystalline structure is implemented traditionally by heating at high temperatures. However, phase transformation under ambient condition without involving external energy has not been reported. Here, we demonstrate that the phase transformation of GeO2 glass to nanocrystals can be triggered at ambient conditions when subjected to aqueous environments. In this case, continuous chemical reactions between amorphous GeO2 and water are responsible for the amorphous-to-crystalline transition. The dynamic evolution process is monitored by using in situ liquid-cell transmission electron microscopy, clearly revealing this phase transformation. It is the hydrolysis of amorphous GeO2 that leads to the formation of clusters with a size of ∼0.4 nm, followed by the development of dense liquid clusters, which subsequently aggregate to facilitate the nucleation and growth of GeO2 nanocrystals. Our finding breaks the traditional understanding of phase transformation and will bring about a significant revolution and contribution to the classical glass-crystallization theories.

Magnesium Citrate Protects Against Vascular Calcification in an Adenine-induced Chronic Renal Failure Rat Model.

BACKGROUND: Hypomagnesemia was identified as a strong risk factor for cardiovascular disease in patients with chronic renal failure (CRF). However, the effects of magnesium (Mg) on vascular calcification (VC) have not been fully elucidated. Thus, we aim to determine the effects of Mg citrate (MgCit) on VC in CRF rats. METHODS: Rats were divided into 5 groups: group 1 (normal diet), group 2 (normal diet with MgCit), group 3 (the VC model of CRF induced by 0.75% adenine and 0.9% phosphorus diet from day 1 to day 28), group 4 (group 3 treated with low-dose MgCit from day 1 to day 42), and group 5 (same as group 3 except the high-dose MgCit). All rats were killed at day 43 with collection of blood and aortas. Then, serum biochemical parameters, VC-related staining, calcium and P contents, alkaline phosphatase contents and activity, expression of alpha smooth muscle actin, and runt-related transcription factor 2 (RUNX2) in aortas were assessed. RESULTS: Group 3 had extensive VC. The VC degree decreased in groups 4 and 5 in a dose-depended manner with reduced calcium content, P levels, alkaline phosphatase content and activity, and protein levels of RUNX2 and increased protein levels of alpha smooth muscle actin in aortas. CONCLUSIONS: MgCit exerted a protective role in VC in adenine-induced CRF rats; thus, it may be a potential drug for the prevention of VC in patients with CRF.

Tunable luminescent properties of BaGd2 O4 :Eu3+ scintillating phosphors by Pr3+ -codoping.

BaGd2 O4 :Eu3+ scintillating phosphors by Pr3+ -codoping were synthesized at 1300°C in air using a solid-state reaction method. The as-synthesized phosphors were characterized by X-ray diffraction (XRD), photoluminescence (PL) including excitation and emission spectra, radioluminescence (RL) spectra excited by X-ray and thermoluminescence (TL) spectra. Both the PL and RL spectra are composed of the featured trivalent europium (Eu3+ ) without any praseodymium (Pr3+ ) ions, and the PL and RL intensities as well as the lifetimes of BaGd2 O4 :Eu3+ scintillating phosphors decrease dramatically with an increasing concentration of Pr3+ ions. Finally, the TL spectra reveal the trap concentration of the existing defects decrease with an increasing concentration of Pr3+ ions, while the relative TL intensity ratio of the high temperature band to the low temperature one increases with an increasing concentration of Pr3+ ions, which results in the afterglow suppression of BaGd2 O4 :Eu3+ scintillating phosphors.