MLKL Protects Pulmonary Endothelial Cells in Acute Lung Injury.

The role of autophagy in pulmonary microvascular endothelial cells (PMVECs) is controversial in LPS-induced acute lung injury (ALI). Mixed lineage kinase domain-like pseudokinase (MLKL) has recently been reported to maintain cell survival by facilitating autophagic flux in response to starvation rather than its well-recognized role in necroptosis. Using a mouse PMVEC and LPS-induced ALI model, we showed that in PMVECs, MLKL was phosphorylated (p-MLKL) and autophagic flux was accelerated at the early stage of LPS stimulation (1-3 h), manifested by increases in concentrations of lipidated MAP1LC3B/LC3B (microtubule-associated protein 1 light chain 3 ß; LC3-II), decreases in concentrations of SQSTM1/p62 (sequestosome 1), and fusion of the autophagosome and lysosome by pHluorin-mKate2-human LC3 assay, which were all reversed by either MLKL inhibitor or siRNA MLKL. In mice, the inhibition of MLKL increased vascular permeability and aggravated mouse ALI upon 3-hour LPS stimulation. The p-MLKL induced by short-term LPS formed multimers to facilitate the closure of the phagophore by HaloTag-LC3 autophagosome completion assay. The charged multivesicular body protein 2A (CHMP2A) is essential in the process of phagophore closure into the nascent autophagosome. In agreement with the p-MLKL change, CHMP2A concentrations markedly increased during 1-3-hour LPS stimulation. CHMP2A knockdown blocked autophagic flux upon LPS stimulation, whereas CHMP2A overexpression boosted autophagic flux and attenuated mouse ALI even in the presence of MLKL inhibitor. We propose that the activated MLKL induced by short-term LPS facilitates autophagic flux by accelerating the closure of the phagophore via CHMP2A, thus protecting PMVECs and alleviating LPS-induced ALI.

Comprehensive analysis of stress-activated protein kinase genes (OsSAPKs) in rice flowering time.

MAIN CONCLUSION: The rice SnRK2 members SAPK4, SAPK5, SAPK7 and SAPK10 are positive regulators involved in the regulation of rice flowering, while other single mutants exhibited no effect on rice flowering. The rice SnRK2 family, comprising 10 members known as SAPK (SnRK2-Associated Protein Kinase), is pivotal in the abscisic acid (ABA) pathway and crucial for various biological processes, such as drought resistance and salt tolerance. Additionally, these members have been implicated in the regulation of rice heading date, a key trait influencing planting area and yield. In this study, we utilized gene editing technology to create mutants in the Songjing 2 (SJ2) background, enabling a comprehensive analyze the role of each SAPK member in rice flowering. We found that SAPK1, SAPK2, and SAPK3 may not directly participate in the regulatory network of rice heading date, while SAPK4, SAPK5, and SAPK7 play positive roles in rice flowering regulation. Notably, polygene deletion resulted in an additive effect on delaying flowering. Our findings corroborate the previous studies indicating the positive regulatory role of SAPK10 in rice flowering, as evidenced by delayed flowering observed in sapk9/10 double mutants. Moving forward, our future research will focus on analyzing the molecular mechanisms underlying SAPKs involvement in rice flowering regulation, aiming to enhance our understanding of the rice heading date relationship network and lay a theoretical foundation for breeding efforts to alter rice ripening dates.

A novel functional allele of Ehd3 controls flowering time in rice.

Rice flowering time determines its geographical distribution and yield traits. As a short-day plant, rice can grow in the northern long-day conditions due to the functional mutations of many photosensitive genes. In this study, to identify novel genes or alleles that regulate flowering time in high latitude region, two cultivar, Dongnong 413 (DN413) and Yukimochi (XN) showing extreme early flowering were used for investigation. DN413 is around 4.0 days earlier than XN, and both cultivars can be grown in II (2500 â„ƒ-2700 â„ƒ) to III (2300 â„ƒ-2500 â„ƒ) accumulated temperature zones. We found that the two cultivars shared the same genotype of heading date genes, including Hd1/2/4/5/6/16/17/18, Ehd2, DTH2, SE5, Hd3a. Importantly, a novel Ehd3 allele characterized by a A1146C substitution was identified, which results in the E382D substitution, hereafter the 382 position E is defined as Hap_E and the 382 position D is defined as Hap_D. Association analysis showed that Hap_E is earlier flowering than Hap_D. Subsequently, we construct DN413 Hap_D line by three times back-crossing DN413 with XN, and found the heading date of DN413 Hap_D was 1.7-3.5 days later than DN413. Moreover, Hap_E and Hap_D of Ehd3 were transformed into ehd3 mutant, respectively, and the Ehd3pro:Ehd3D/ehd3 flowered later than that Ehd3pro:Ehd3E/ehd3 by around 4.3 days. Furthermore, we showed Ehd3 functions as a transcriptional suppressor and the substitution of Asp-382 lost the inhibition activity in protoplasts. Finally, a CAPS marker was developed and used for genotyping and marker assistant breeding. Collectively, we discovered a novel functional allele of Ehd3, which can used as a valuable breeding target. Supplementary Information: The online version contains supplementary material available at 10.1007/s11032-024-01472-x.

OsWRKY78 regulates panicle exsertion via gibberellin signaling pathway in rice.

Panicle exsertion is one of the crucial agronomic traits in rice (Oryza sativa). Shortening of panicle exsertion often leads to panicle enclosure and severely reduces seed production. Gibberellin (GA) plays important roles in regulating panicle exsertion. However, the underlying mechanism and the relative regulatory network remain elusive. Here, we characterized the oswrky78 mutant showing severe panicle enclosure, and found that the defect of oswrky78 is caused by decreased bioactive GA contents. Biochemical analysis demonstrates that OsWRKY78 can directly activate GA biosynthesis and indirectly suppress GA metabolism. Moreover, we found OsWRKY78 can interact with and be phosphorylated by mitogen-activated protein kinase (MAPK) kinase OsMAPK6, and this phosphorylation can enhance OsWRKY78 stability and is necessary for its biological function. Taken together, these results not only reveal the critical function of OsWRKY78, but also reveal its mechanism via mediating crosstalk between MAPK and the GA signaling pathway in regulating panicle exsertion.

OsMAPK6 positively regulates rice cold tolerance at seedling stage via phosphorylating and stabilizing OsICE1 and OsIPA1.

Rice is a chilling-sensitive plant, and extremely low temperatures seriously decrease rice production. Several genes involved in chilling stress have been reported in rice; however, the chilling signaling in rice remains largely unknown. Here, we investigated the chilling tolerance phenotype of overexpression of constitutive active OsMAPK6 (CAMAPK6-OE) and OsMAPK6 mutant dsg1, and demonstrated that OsMAPK6 positively regulated rice chilling tolerance. It was shown that, under cold stress, the survival rate of dsg1 was significantly lower than that of WT, whereas CAMAPK6-OE display higher survival rate than WT. Physiological assays indicate that ion leakage and dead cell in dsg1 was much more severe than those in WT and CAMAPK6-OE. Consistently, expression of chilling responsive genes in dsg1, including OsCBFs and OsTPP1, was significantly lower than that of in WT and CAMAPK6-OE. Biochemical analyses revealed that chilling stress promotes phosphorylation of OsMAPK6. Besides, we found that OsMAPK6 interacts with and phosphorylates two key regulators in rice cold signaling, OsIPA1 and OsICE1, and then enhance their protein stability. Overall, our results revealed a cold-induced OsMAPK6-OsICE1/OsIPA1 signaling cascade by which OsMAPK6 was involved in rice chilling tolerance, which provides novel insights to understand rice cold response at seedling stage.

Suppression of the height deviation on metal bumps manufacturing by an ultrasonic vibration control.

On-demand droplet printing based on piezoelectric micro-jet device (PMJD) is considered a flexible and high-precision method to generate metal droplets directly for flip-chip bonding in industrial electronics. However, the quality of flip-chip bonding is closely related to the height deviation of the solidified droplets (the metal bumps), which is influenced by the complicated hydrodynamics of impacting and oscillation of the droplet with oxide film. Here, the numerical and experimental investigations are first conducted to study the effect of the liquid bridge and deposition parameters on the height deviation of the solidified droplets. The rapid oxidation of the liquid bridge and under-oscillation during the deposition process are the main reasons for height deviation. In addition, the undamped oscillation with high-speed impact and instantaneous solidification also deteriorates the height deviation. To this end, an oscillation control strategy based on ultrasonic-assisted metal droplet deposition (UAMDD) is proposed and verified to be a reliable regulation strategy to suppress the height deviation of the printed bumps. The effective regulating range of height deviation is studied experimentally by changing the ultrasonic vibration amplitude. Finally, a 10 × 10 array composed of 100 solidified metal droplets is printed with the UAMDD, which has the height deviation of 554 ± 6 µm. And the dimensionless height deviation (Δh/h) of solidified bumps is stayed below 2.1 %.

Calorie restriction mimetic, resveratrol, attenuates hepatic ischemia and reperfusion injury through enhancing efferocytosis of macrophages via AMPK/STAT3/S1PR1 pathway.

Calorie restriction (CR) mimetic, resveratrol (RSV), has the capacity of promoting phagocytosis. However, its role in hepatic ischemia and reperfusion injury (HIRI) remains poorly understood. This study aimed to investigate the effect of RSV on alleviating HIRI and explore the underlying mechanisms. RSV was intraperitoneally injected in mice HIRI model, while RSV was co-incubated with culture medium for 24 h in RAW 264.7 cells and kupffer cells. Macrophage efferocytosis was assessed by immunostaining of PI and F4/80. The clearance of apoptotic neutrophils in the liver was determined by immunostaining of Ly6-G and cleaved-caspase-3. HE staining, Suzuki's score, serum levels of ALT, AST, TNF-α and IL-1ß were analyzed to evaluate HIRI. The efferocytosis inhibitor, Cytochalasin D, was utilized to investigate the effect of RSV on HIRI. Western blot was employed to measure the levels of AMPKα, phospho-AMPKα, STAT3, phospho-STAT3 and S1PR1. SiSTAT3 and inhibitors targeting AMPK, STAT3 and S1PR1, respectively, were used to confirm the involvement of AMPK/STAT3/S1PR1 pathway in RSV-mediated efferocytosis and HIRI. RSV facilitated the clearance of apoptotic neutrophils and attenuated HIRI, which was impeded by Cytochalasin D. RSV boosted macrophage efferocytosis by up-regulating the levels of phospho-AMPKα, phospho-STAT3 and S1PR1, which was reversed by AMPK, STAT3 and S1PR1 inhibitors, respectively. Inhibition of STAT3 suppressed RSV-induced clearance of apoptotic neutrophils and exacerbated HIRI. CR mimetic, RSV, alleviates HIRI by promoting macrophages efferocytosis through AMPK/STAT3/S1PR1 pathway, providing valuable insights into the mechanisms underlying the protective effects of CR on attenuating HIRI.

Development of a Highly Adaptive Miniature Piezoelectric Robot Inspired by Earthworms.

Miniature resonant piezoelectric robots have the advantages of compact structure, fast response, high speed, and easy control, which have attracted the interest of many scholars in recent years. However, piezoelectric robots usually suffer from the problem of poor adaptability due to the micron-level amplitude at the feet. Inspired by the fact that earthworms have actuation trajectories all around their bodies to move flexibly under the ground, a miniature piezoelectric robot with circumferentially arranged driving feet to improve adaptability is proposed. Notably, a longitudinal-vibration-compound actuation principle with multilegged collaboration is designed to achieve the actuation trajectories around the robot, similar to the earthworms. The structure and operating principle are simulated by the finite element method, and the prototype is fabricated. The robot weighs 22.7 g and has dimensions of 35.5 × 36.5 × 47 mm3. The robot is tethered to an ultrasonic power supply, and the experimental results show that the speed reaches 179.35 mm s-1  under an exciting signal with a frequency of 58.5 kHz and a voltage of 200 Vp-p. High adaptability is achieved by the proposed robot, it can move on flat, fold, concave, and convex surfaces, and even in an inclined or rotating tube.

Miniature Modular Reconfigurable Underwater Robot Based on Synthetic Jet.

Modular reconfigurable robots exhibit prominent advantages in the reconnaissance and exploration tasks within unstructured environments for their characteristics of high adaptability and high robustness. However, due to the limitations in locomotion mechanism and integration requirements, the modular design of miniature robots in the aquatic environment encounters significant challenges. Here, a modular strategy based on the synthetic jet principle is proposed, and a modular reconfigurable robot system is developed. Specialized bottom and side jet actuators are designed with vibration motors as excitation sources, and a motion module is developed incorporating the jet actuators to realize three-dimensional agile motion. Its linear, rotational, and ascending motion speeds reach 70.7 mm s-1, 3.3 rad s-1, and 28.7 mm s-1, respectively. The module integrates the power supply, communication, and control system with a small size of 48 mm × 38 mm × 38 mm, which ensures a wireless controllable motion. Then, various configurations of the multi-module robot system are established with corresponding motion schemes, and the experiments with replaceable intermediate modules are further conducted to verify the transportation and image-capturing functions. This work demonstrates the effectiveness of synthetic jet propulsion for aquatic modular reconfigurable robot systems, and it exhibits profound potential in future underwater applications.

Dexmedetomidine facilitates autophagic flux to promote liver regeneration by suppressing GSK3ß activity in mouse partial hepatectomy.

INTRODUCTION: Dexmedetomidine (DEX), a highly selective α2-adrenergic receptor agonist, is widely used for sedation and anesthesia in patients undergoing hepatectomy. However, the effect of DEX on autophagic flux and liver regeneration remains unclear. OBJECTIVES: This study aimed to determine the role of DEX in hepatocyte autophagic flux and liver regeneration after PHx. METHODS: In mice, DEX was intraperitoneally injected 5 min before and 6 h after PHx. In vitro, DEX was co-incubated with culture medium for 24 h. Autophagic flux was detected by LC3-II and SQSTM1 expression levels in primary mouse hepatocytes and the proportion of red puncta in AML-12 cells transfected with FUGW-PK-hLC3 plasmid. Liver regeneration was assessed by cyclinD1 expression, Edu incorporation, H&E staining, ki67 immunostaining and liver/body ratios. Bafilomycin A1, si-GSK3ß and Flag-tagged GSK3ß, α2-ADR antagonist, GSK3ß inhibitor, AKT inhibitor were used to identify the role of GSK3ß in DEX-mediated autophagic flux and hepatocyte proliferation. RESULTS: Pre- and post-operative DEX treatment promoted liver regeneration after PHx, showing 12 h earlier than in DEX-untreated mice, accompanied by facilitated autophagic flux, which was completely abolished by bafilomycin A1 or α2-ADR antagonist. The suppression of GSK3ß activity by SB216763 and si-GSK3ß enhanced the effect of DEX on autophagic flux and liver regeneration, which was abolished by AKT inhibitor. CONCLUSION: Pre- and post-operative administration of DEX facilitates autophagic flux, leading to enhanced liver regeneration after partial hepatectomy through suppression of GSK3ß activity in an α2-ADR-dependent manner.

Vibration-Induced-Flow Mechanism and Its Application in Water Surface Robot.

Vibration is a common strategy for aquatic organisms to achieve their life activities, especially at the air-water interface. For the locomotion of small creatures, the organs with plate features are often used on water surfaces, which inspires relevant studies about using thin plates for robot propulsions. However, the influence of the general deformations of thin plates on the generated flow fields has not been considered. Here, a comprehensive investigation is conducted about the flow fields that arose by vibrations of thin plates and the potential as locomotion strategies are explored. It is discovered that as thin plates are subjected to vibration excitations on the water surface, the produced flow fields are mainly determined by the vibration shapes, and the influence rules of plate deformations on the flow fields are identified. The main factors producing asymmetric flow fields are analyzed to realize the morphology control of the flow fields. Then, to determine effective locomotion strategies on the water surface, the flow fields stimulated by integrated vibration exciters are explored, and 2 water surface robots are developed consequentially, which exhibit superior motion performance. This work reveals the basic rules of the vibration-induced-flow mechanism by thin plates and establishes new locomotion strategies for aquatic robots.