Apelin-13 improves pulmonary epithelial barrier function in a mouse model of LPS-induced acute lung injury by inhibiting Chk1-mediated DNA damage.

Apelin-13, a type of active peptide, can alleviate lipopolysaccharide (LPS)-induced acute lung injury (ALI). However, the specific mechanism is unclear. Cell cycle checkpoint kinase 1 (Chk1) plays an important role in DNA damage. Here, we investigated the regulatory effect of Apelin on Chk1 in ALI. Chk1-knockout and -overexpression mice were used to explore the role of Chk1 in LPS-induced ALI mice treated with or without Apelin-13. In addition, A549 cells were also treated with LPS to establish a cell model. Chk1 knockdown inhibited the destruction of alveolar structure, the damage of lung epithelial barrier function, and DNA damage in the ALI mouse model. Conversely, Chk1 overexpression had the opposite effect. Furthermore, Apelin-13 reduced Chk1 expression and DNA damage to improve the impaired lung epithelial barrier function in the ALI model. However, the high expression of Chk1 attenuated the protective effect of Apelin-13 on ALI. Notably, Apelin-13 promoted Chk1 degradation through autophagy to regulate DNA damage in LPS-treated A549 cells. In summary, Apelin-13 regulates the expression of Chk1 by promoting autophagy, thereby inhibiting epithelial DNA damage and repairing epithelial barrier function.

Apoptotic Bodies Derived from Fibroblast-Like Cells in Subcutaneous Connective Tissue Inhibit Ferroptosis in Ischaemic Flaps via the miR-339-5p/KEAP1/Nrf2 Axis.

Preventing and treating avascular necrosis at the distal end of the flaps are critical to surgery success, but current treatments are not ideal. A recent study shows that apoptotic bodies (ABs) generated near the site of apoptosis can be taken up and promote cell proliferation. The study reveals that ABs derived from fibroblast-like cells in the subcutaneous connective tissue (FSCT cells) of skin flaps promoted ischaemic flap survival. It is also found that ABs inhibited cell death and oxidative stress and promoted M1-to-M2 polarization in macrophages. Transcriptome sequencing and protein level testing demonstrated that ABs promoted ischaemic flap survival in endothelial cells and macrophages by inhibiting ferroptosis via the KEAP1-Nrf2 axis. Furthermore, microRNA (miR) sequencing data and in vitro and in vivo experiments demonstrated that ABs inhibited KEAP1 by delivering miR-339-5p to exert therapeutic effects. In conclusion, FSCT cell-derived ABs inhibited ferroptosis, promoted the macrophage M1-to-M2 transition via the miR-339-5p/KEAP1/Nrf2 axis and promoted ischaemic flap survival. These results provide a potential therapeutic strategy to promote ischaemic flap survival by administering ABs.

FGF10 protects against LPS-induced epithelial barrier injury and inflammation by inhibiting SIRT1-ferroptosis pathway in acute lung injury in mice.

Pulmonary alveolar epithelial cell injury is considered the main pathological and physiological change in acute lung injury. Ferroptosis in alveolar epithelial cells is one of crucial factors contributing to acute lung injury (ALI). Therefore, reducing ferroptosis and repair epithelial barrier is very necessary. More and more evidence suggested that FGF10 plays an important role in lung development and repair after injury. However, the relationship between FGF10 and ferroptosis remains unclear. This study aims to explore the regulatory role of FGF10 on ferroptosis in ALI. Differential gene expression analysis indicated that genes associated with ferroptosis showed that FGF10 can significantly alleviate LPS induced lung injury and epithelial barrier damage by decreasing levels of malonaldehyde(MDA), and lipid ROS. SIRT1 activator (Resveratrol) and inhibitor (EX527) are used in vivo showed that FGF10 protects ferroptosis of pulmonary epithelial cells through SIRT1 signal. Furthermore, knockdown of FGFR2 gene reduced the protective effect of FGF10 on acute lung injury in mice and SIRT1 activation. After the application of NRF2 inhibitor ML385 in vitro, the results showed that SIRT1 regulated the expression of ferroptosis related proteins NRF2, GPX4 and FTH1 are related to activation of NRF2. These data indicate that SIRT-ferroptosis was one of the critical mechanisms contributing to LPS-induced ALI. FGF10 is promising as a therapeutic candidate against ALI through inhibiting ferroptosis.

Antioxidant mitoquinone ameliorates EtOH-LPS induced lung injury by inhibiting mitophagy and NLRP3 inflammasome activation.

Chronic ethanol abuse is a systemic disorder and a risk factor for acute respiratory distress syndrome (ARDS) and chronic obstructive pulmonary disease (COPD). However, the mechanisms involved are unknown. One explanation is that ethanol produces damaging reactive oxygen species (ROS) and disturbs the balance of mitochondria within the lungs to promote a pro-injury environment. We hypothesized that targeting an antioxidant to the mitochondria would prevent oxidative damage and attenuate EtOH-LPS-induced lung injury. To test this, we investigated the effects of mitochondria-targeted ubiquinone, Mitoquinone (MitoQ) on ethanol-sensitized lung injury induced by LPS. Lung inflammation, ROS, mitochondria function, and mitophagy were assessed. We demonstrated that chronic ethanol feeding sensitized the lung to LPS-induced lung injury with significantly increased reactive oxygen species ROS level and mitochondrial injury as well as lung cellular NLRP3 inflammasome activation. These deleterious effects were attenuated by MitoQ administration in mice. The protective effects of MitoQ are associated with decreased cellular mitophagy and NLRP3 inflammasome activation in vivo and in vitro. Taken together, our results demonstrated that ethanol aggravated LPS-induced lung injury, and antioxidant MitoQ protects from EtOH-LPS-induced lung injury, probably through reducing mitophagy and protecting mitochondria, followed by NLRP3 inflammasome activation. These results will provide the prevention and treatment of ethanol intake effects with new ideas.

Sensitive detection of radio-frequency field phase with interacting dark states in Rydberg atoms.

An efficient scheme of phase measurement of a radio-frequency (RF) field is proposed by interacting dark states. Under the condition of electromagnetically induced transparency (EIT), the four-level Rydberg atom exhibits two windows. Compared with the transmission spectrum on resonance, the linewidths of absorption peaks off resonance are very narrow due to the interaction of double dark states. It is interesting to find that the distance of absorption peaks shifts approximately linearly with the phase of an RF field, which can be used to measure the RF field phase. Simulation results show that the linewidth of an absorption peak can be narrowed by more than one order of magnitude, and a narrow linewidth improves the detectable minimum phase difference by more than six times. It helps to reduce analyzation complexity and increase sensing resilience. The dependence of phase measurement on the control field and RF field is also investigated.

FGF10 ameliorates lipopolysaccharide-induced acute lung injury in mice via the BMP4-autophagy pathway.

Introduction: Damage to alveolar epithelial cells caused by uncontrolled inflammation is considered to be the main pathophysiological change in acute lung injury. FGF10 plays an important role as a fibroblast growth factor in lung development and lung diseases, but its protective effect against acute lung injury is unclear. Therefore, this study aimed to investigate protective effect and mechanism of FGF10 on acute lung injury in mice. Methods: ALI was induced by intratracheal injection of LPS into 57BL/6J mice. Six hours later, lung bronchoalveolar lavage fluid (BALF) was acquired to analyse cells, protein and the determination of pro-inflammatory factor levels, and lung issues were collected for histologic examination and wet/dry (W/D) weight ratio analysis and blot analysis of protein expression. Results: We found that FGF10 can prevent the release of IL-6, TNF-α, and IL-1ß, increase the expression of BMP4 and autophagy pathway, promote the regeneration of alveolar epithelial type Ⅱ cells, and improve acute lung injury. BMP4 gene knockdown decreased the protective effect of FGF10 on the lung tissue of mice. However, the activation of autophagy was reduced after BMP4 inhibition by Noggin. Additionally, the inhibition of autophagy by 3-MA also lowered the protective effect of FGF10 on alveolar epithelial cells induced by LPS. Conclusions: These data suggest that the protective effect of FGF10 is related to the activation of autophagy and regeneration of alveolar epithelial cells in an LPS-induced ALI model, and that the activation of autophagy may depend on the increase in BMP4 expression.

Apelin-13-Mediated AMPK ameliorates endothelial barrier dysfunction in acute lung injury mice via improvement of mitochondrial function and autophagy.

Maintaining the pulmonary endothelial barrier that prevents the exudation of inflammatory factors and proteins is the key to the treatment of acute lung injury (ALI). Apelin-13 plays an important role in vascular diseases; however, the protective effects of Apelin-13 on ALI with pulmonary endothelial barrier are unknown. Therefore, mice and human umbilical vein endothelial cells (HUVECs) were injured by LPS following Apelin-13 administration. ALI mice showed reduced pulmonary vascular permeability, adhesion junction, mitochondrial function, mitochondrial biogenesis, and autophagy compared to the control group. Apelin-13 administration in ALI mice ameliorated LPS-induced lung injury, pulmonary vascular permeability, mitochondrial function, and promoted autophagic flux in mice and HUVECs. However, the effect of Apelin-13 was reduced after AMPK inhibition using Compound C. These data suggest that Apelin-13 ameliorates pulmonary vascular permeability in mice with ALI induced by LPS, which may be related to enhanced phosphorylation of AMPK to regulate mitochondrial function and autophagy.

Severity of early allograft dysfunction following donation after circulatory death liver transplantation: a multicentre study.

BACKGROUND: Early allograft dysfunction (EAD) is associated with decreased graft and patient survival rates. This study aimed to identify the severity of EAD and develop a predictive model for EAD after donation after circulatory death (DCD) liver transplantation (LT). Furthermore, the influence of operative time on EAD incidence was also evaluated. METHODS: In this retrospective, multicentre cohort study, nomograms were established based on a single-centre training cohort (n=321) and validated in a 3-center validation cohort (n=501). RESULTS: The incidence rate of EAD was 46.4% (149/321) in the training cohort and 40.5% (203/501) in the validation cohort. Of the 149 EAD patients in the training cohort, 77 patients with either elevated alanine aminotransferase (ALT) or aspartate aminotransferase (AST) were classified as having EAD type A, and the rest of the EAD patients were classified as having EAD type B. Recipients with EAD type B had lower graft and patient survival rates than recipients with EAD type A (P=0.043 and 0.044, respectively). We further developed a nomogram to predict EAD (graft weight, cold ischemia time, donor age, model for end-stage liver disease (MELD) score) and another nomogram to predict EAD type B (graft weight, cold ischemia time, MELD score). The nomograms for the prediction of EAD and EAD type B had good discrimination [concordance index (C-index) =0.712 (0.666-0.758), 0.707 (0.641-0.773)] and calibration [Hosmer-Lemeshow (HL) P=0.384, P=0.425] in the validation cohort. An increased operative time (>6 h) was associated with increased EAD and EAD type B incidence in the high-risk group (P=0.005, P=0.020, respectively). CONCLUSIONS: EAD type B was associated with decreased graft and patient survival rates. The novel nomograms effectively predicted the incidence of EAD and EAD type B in DCD LT patients.

Proposal of Rydberg atomic receiver for amplitude-modulated microwave signals with active Raman gain.

An efficient scheme for a microwave (MW) receiver is proposed based on the active Raman gain (ARG) in Rydberg atoms. The 87Rb atoms are excited to the Rydberg state (53D5/2), and the gain spectrum has a single gain peak. The MW field is resonant with the Rydberg transition (53D5/2→54P3/2), resulting in a split in the gain spectrum. The frequency splitting of two peaks depends linearly on the MW field strength. The distortion and attenuation of the probe field are reduced, due to the system's operating in the stimulated Raman emission mode. Simulation results show that the fidelity of MW communication based on the Rydberg atomic ARG scheme is improved by at least 10 times compared to that based on an electromagnetically induced transparency scheme, and the system seems more robust to amplitude modulation signals with different modulation depths.

A Rare 3D Porous Inorganic-Organic Hybrid Polyoxometalate Framework Based on a Cubic Polyoxoniobate-Cupric-Complex Cage with a High Water Vapor Adsorption Capacity.

A rare 3D porous inorganic-organic polyoxoniobate framework based on the cubic polyoxoniobate-cupric-complex cage {[Cu(en)2]@{[Cu2(en)2(trz)2]6(Nb68O188)}} (1a), has been successfully synthesized by a hydrothermal method. The cubic cages 1a are connected with 4-(tetrazol-5-yl)pyridine to form a 1D pillar-like chain structure, and every 1D pillar-like chain is further linked with four adjacent pillar-like chains by the [Cu(en)2]2+ complex to form a 3D porous inorganic-organic polyoxoniobate framework with 4-connected CdSO4-type topology. To our knowledge, it is the first time that three different types of organic ligands are simultaneously introduced into one polyoxoniobate. This material also exhibits a high vapor adsorption capacity and good ionic conductivity properties.

All-inorganic open frameworks based on gigantic four-shell Ln@W8@Ln8@(SiW12)6 clusters.

A series of POM-based all-inorganic open frameworks, H9[Ln9W8(µ4-O)12(µ2-O)24(H2O)24](SiW12O40)3·60H2O (1-Ln, Ln = La, Pr and Nd), have been fabricated and structurally characterized for the first time. The unique architectures are constructed from nanoscale four-shell Ln@W8@Ln8@(SiW12)6 clusters. Additionally, the porous nature of the frameworks has also been investigated.

Preoperative risk stratification for early recurrence of HBV-related hepatocellular carcinoma after deceased donor liver transplantation: a five-eight model development and validation.

BACKGROUND: Early recurrence of hepatocellular carcinoma (HCC) after liver transplantation (LT) is associated with poor surgical outcomes. This study aims to construct a preoperative model to predict individual risk of post-LT HCC recurrence. METHODS: Data of 748 adult patients who underwent deceased donor LT for HCC between January 2015, and February 2019 were collected retrospectively from the China Liver Transplant Registry database and randomly divided into training (n = 486) and validation(n = 262) cohorts. A multivariate analysis was performed and the five-eight model was developed. RESULTS: A total of 748 patients were included in the study; of them, 96% had hepatitis B virus (HBV) and 84% had cirrhosis. Pre-LT serum alpha-fetoprotein (AFP), tumor number and largest tumor diameter were incorporated to construct the 5-8 model which can stratify patients accurately according to their risk of recurrence into three prognostic subgroups; low-(0-5 points), medium-(6-8 points) and high-risk (> 8 points) with 2-year post-LT recurrence rate of (5,20 and 51%,p <  0.001) respectively. The 5-8 model was better than Milan, Hangzhou, and AFP-model for prediction of HCC early recurrence. These findings were confirmed by the results of the validation cohort. CONCLUSIONS: The 5-8 model is a simple validated and accurate tool for preoperative stratification of early recurrence of HCC after LT.

A new type of composite MOFs based on high-valent Sb(v)-based units and cuprous-halide clusters.

An unusual high-valent Sb(v)-based unit [SbL2]- (L = 2-(hydroxymethyl)-2-(pyridin-4-yl)-1,3-propanediol) was developed for the first time to combine with various cuprous-halide clusters for the construction of a brand-new class of heterometallic MOFs. This work not only promotes the limited development of Sb-based MOFs, but also provides a practical strategy for developing new types of composite materials.

Inorganic-organic hybrid high-dimensional polyoxotantalates and their structural transformations triggered by water.

The first two inorganic-organic hybrid three-dimensional (3D) polyoxotantalates (POTas) and the first two inorganic-organic hybrid 2D POTas have been obtained. All of these high-dimensional POTas are built from a new-type POTa dimeric cluster {Cu(en)(Ta6O19)}2/{Cu(enMe)(Ta6O19)}2 (en = ethylenediamine, enMe = 1,2-diaminopropane) bridged by copper complexes. Interestingly, extended POTas 1 and 3 can undergo single-crystal to single-crystal structural transformations triggered by water.

Prediction of Early Recurrence of Hepatocellular Carcinoma in Patients with Cirrhosis Who Had Received Deceased Donor Liver Transplantation: A Multicenter Study.

BACKGROUND Early recurrence after liver transplantation (LT) is still a clinical problem. This multicenter study evaluated the Milan, Hangzhou, and AFP model-based criteria for prediction of early recurrence of HCC in patients with cirrhosis who had undergone LT. MATERIAL AND METHODS From the China Liver Transplant Registry (CLTR) database, we analyzed data of 589 HCC patients who had undergone LT between Jan 2015 and Jan 2019. Imaging data and AFP levels were evaluated immediately before LT. Recurrence and overall survival rates at 2 years were tested using the Kaplan-Meier estimate. The Milan criteria, Hangzhou criteria, and AFP model-based criteria were evaluated. RESULTS We found that 62.0%, 91.2%, and 67.6% of patients were within the Milan criteria, Hangzhou criteria, and AFP model-based criteria, respectively. The 2-year recurrence rate was 8.9%, 15.8%, and 11.8% with corresponding overall survival of 85.3%, 82.7%, and 86.5%, respectively. The 2-year recurrence rate was different in patients fulfilling and exceeding the AFP model-based criteria among patients who met either the Milan criteria (7.9% vs. 18.8%, HR=3.83, p=0.006) or Hangzhou criteria (12.0% vs. 27.6%, HR=2.95, p<0.001). However, the 2-year recurrence rate was not significantly different among patients who were beyond either the Milan or Hangzhou criteria. CONCLUSIONS For the prediction of early recurrence of HCC in patients with cirrhosis after liver transplantation, Milan criteria, Hangzhou criteria, and AFP model-based criteria are effective predictive tools for stratification of patients into low- and high-risk groups of recurrence with different prognoses. The AFP model-based criteria can identify a subgroup of patients with high risk of recurrence among patients who met either Milan or Hangzhou criteria.

Development of a new Lindqvist-like Fe6 cluster secondary building unit for MOFs.

This work demonstrates a new Lindqvist-like [FeIII6(µ6-O)L4Cl6]2- (Fe6, L = 2-(hydroxymethyl)-2-(pyridin-4-yl)-1,3-propanediol) cluster for the construction of a novel class of Fe-cluster organic frameworks. The novel Fe6 cluster can be used to build not only a homometallic MOF, but also a heterometallic MOF by introducing copper halide clusters to the reaction system. In particular, the heterometallic MOF achieved a skillful combination of Fe6 SBU and cuprous-halide clusters for the first time. Our synthesis strategy opens up an effective avenue to novel Fe-cluster-based MOF materials.

A nested Cu24@Cu72-based copper-organic polyhedral framework for selective adsorption of cationic dyes.

A nested Cu24@Cu72 copper-organic framework, [Cu5(bdc)4(ina)2(H2O)3]·solvent (1, H2bdc = 1,3-benzenedicarboxylic acid and Hina = isonicotinic acid) based on paddlewheel Cu2(COO)4 SBUs, has been synthesized. There are three types of cages with different sizes and shapes: Cu24-cage, Cu60-cage and Cu72-cage. The Cu72-cage, which is the highest-nuclearity Cu-cage reported to date, encapsulates a Cu24-cage to form a double-walled Cu24@Cu72 cage-within-cage structure. Dye adsorption studies reveal that compound 1 can rapidly and selectively adsorb cationic dyes.

A Chromium-Substituted Polyoxoniobate with High Ionic Conductivity.

A rare and novel Cr-substituted polyoxoniobate (PONb), [Cr2.5Nb27.5O66(OH)20(H2O)2]7-, has been synthesized by a combination of hydrothermal and conventional solution methods. The PONb shows an unknown tetrameric structure, which is the largest Cr-containing PONb to date. Interestingly, every two PONb tetramers can be joined together by alkali-metal cations to form a discrete cubelike ionic cluster. The obtained PONb not only enriches the very limited members of the Cr-substituted PONb family but also exhibits high ionic conductivity.

Construction of Two High-Nuclear 3d-4d Heterometallic Cluster Organic Frameworks by Introducing a Bifunctional Tripodal Alcohol as a Structure-Directing Agent.

Two unique heterometallic cluster organic frameworks, [Cd4 MnIII 4 MnII 6 (Tri)4 (CH3 COO)14 (µ4 -O)2 (µ3 -O)2 (H2 O)2 ] Cd(H2 O)2 ⋅9 H2 O (1) and Cu[Cd5 Cu6 (Tri)4 (CH3 COO)9 (H2 O)4 ]2 (CH3 COO)3 ⋅24 H2 O (2) (H3 Tri=2-(hydroxymethyl)-2-(pyridine-4-yl)-1,3-propanediol), have been successfully prepared by employing a bifunctional tripodal alcohol ligand as a structure-directing agent. Crystal structure analyses reveal that 1 represents a rare example of frameworks constructed from Cd-Mn heterometallic chains, and 2 is the first heterometallic MOF based on highest-nuclear Cd-Cu heterometallic cluster building blocks. Furthermore, the magnetic properties and gas adsorption abilities of 1 and 2 were systematically studied.

Recent Advances in Zeolite-like Cluster Organic Frameworks.

During the past decade, research on the design and synthesis of zeolite-like metal-organic frameworks (ZMOFs) has developed greatly. As an important subclass of ZMOFs, zeolite-like cluster organic frameworks (ZCOFs) built from 4-connected metal-cluster secondary building units (SBUs) and appropriate linear organic ligand bridges have attracted sustained interest, because such materials not only integrate the merits of inorganic zeolites, ZMOFs, and metal clusters, including interesting topologies, high surface areas, extra-large cavities and channels, structural tunability, and unique physicochemical properties from various metal clusters, but also open up a new avenue to design and fabricate hybrid zeolite-like materials that have many potential applications in material sciences. In this review, recent developments in ZCOFs are summarized by classifying the ZCOFs into four categories according to the composition of the SBUs: 1) ZCOFs based on metal-halide cluster SBUs, 2) ZCOFs based on metal-oxygen cluster SBUs, 3) ZCOFs based on metal-chalcogen cluster SBUs, and 4) ZCOFs based on mixed types of metal-cluster SBUs. Besides, challenges associated with the design and synthesis of ZCOFs and the vast potential of this area are also discussed.