Bioinformatic Analysis of the Significance of the KIR2DL4 Gene in Recurrent Implantation Failure.

Related studies have pointed out that Killer immunoglobulin-like receptor 2DL4 (KIR2DL4) was associated with vascular remodeling in early pregnancy, and it might play an important role in immunity. In this study, recurrent implantation failure (RIF)-related GSE58144 dataset was extracted from the Gene Expression Omnibus (GEO) database. Firstly, the immune micro-environment analyses were conducted to analyze the pathogenesis of KIR2DL4 in RIF. Then, the gene set enrichment analysis (GSEA) was performed to investigate the function of KIR2DL4. Moreover, the TF-mRNA-miRNA and the co-expression networks were constructed to reveal the potential regulation of KIR2DL4. Furthermore, the genes that were associated with KIR2DL4 and differentially expressed in RIF were obtained and defined as key genes, and the functions of these genes were further explored. KIR2DL4 could be used for clinical diagnosis of RIF, and it was correlated with the changes in the immune micro-environment in RIF. From the perspective of function, KIR2DL4 was associated with complement and coagulation cascades, natural killer cell-mediated cytotoxicity, etc. Moreover, the TF-mRNA-miRNA regulatory network was constructed with KIR2DL4, 9 TFs, and 29 miRNAs. Furthermore, KIR2DL4, ACSM1, IL2RB, and PTPN11 were screened as key genes, which were associated with immune-related functions. This study deeply analyzed the function of KIR2DL4 and its role in RIF, and we found that STAT1 might up-regulate KIR2DL4 by INF-γ/JAK2/STAT1 signaling pathway. Besides, over-expressed KIR2DL4 in the mid-luteal endometrium might influence embryo implantation by affecting the embryo implantation microenvironment, which might help deepen the understanding of the molecular mechanism of RIF.

Suzuki-Miyaura Cross-Coupling Reaction Catalyzed by Al12M (M = Be, Al, C, and P) Superatoms with Different Numbers of Valence Electrons.

The exploration of low-cost, efficient, environmentally safe, and selective catalysts for the activation of carbon-halogen bonds has become an important and challenging topic in modern chemistry. With the help of density functional theory (DFT), it is found that phenyl bromide (PhBr) can be efficiently chemisorbed by the Al12M (M = Be, Al, C, and P) superatoms via forming highly polarized Al-Br covalent bonds, where the C-Br bonds of PhBr can be effectively activated through the electron transfer from Al12M. The different electronic structures of these four Al12M superatoms pose a substantial effect on their performances on the activation of PhBr and the catalytic mechanisms of the Suzuki-Miyaura (SM) reaction. Among them, the alkali-metal-like superatom Al12P exhibits the best performance for the activation of PhBr. In particular, Al13 and Al12P with open-shell electronic structures exhibit catalytic performances comparable to those of previously reported catalysts for this coupling reaction. Hence, it is highly expected that Al13 and Al12P could be used as novel superatom catalysts for C-C coupling reactions and, therefore, open up new possibilities to use nonprecious superatoms in catalyzing the activation and transformation of carbon-halogen bonds.

Single-frequency orbital angular momentum switchable modes from a microchip laser.

We demonstrate the direct generation of single-frequency switchable orbital angular momentum (OAM) modes in a 1 µm wavelength range using a Nd:YVO4 microchip laser. The 808 nm laser diode pump beam is shaped into annular through an axicon associated with a lens. By adjusting the diameter and power of the annular pump beam, various OAM modes with different mode volumes can oscillate inside the Nd:YVO4 microchip. Moreover, a single-frequency output is also available due to the short cavity of the microchip. In the proof-of-principle experiment, single-frequency twofold multiplexed OAM modes | ± 1> and | ± 2> are generated, with experimentally measured fidelity higher than 96%. This work presents a compact and versatile single-frequency OAM source and will inspire multiple advanced scenarios ranging from classical to quantum photonics.

User-Friendly Replication-Competent MAdV-1 Vector System with a Cloning Capacity of 3.3 Kilobases.

Mouse adenoviruses (MAdV) play important roles in studying host-adenovirus interaction. However, easy-to-use reverse genetics systems are still lacking for MAdV. An infectious plasmid pKRMAV1 was constructed by ligating genomic DNA of wild-type MAdV-1 with a PCR product containing a plasmid backbone through Gibson assembly. A fragment was excised from pKRMAV1 by restriction digestion and used to generate intermediate plasmid pKMAV1-ER, which contained E3, fiber, E4, and E1 regions of MAdV-1. CMV promoter-controlled GFP expression cassette was inserted downstream of the pIX gene in pKMAV1-ER and then transferred to pKRMAV1 to generate adenoviral plasmid pKMAV1-IXCG. Replacement of transgene could be conveniently carried out between dual BstZ17I sites in pKMAV1-IXCG by restriction-assembly, and a series of adenoviral plasmids were generated. Recombinant viruses were rescued after transfecting linearized adenoviral plasmids to mouse NIH/3T3 cells. MAdV-1 viruses carrying GFP or firefly luciferase genes were characterized in gene transduction, plaque-forming, and replication in vitro or in vivo by observing the expression of reporter genes. The results indicated that replication-competent vectors presented relevant properties of wild-type MAdV-1 very well. By constructing viruses bearing exogenous fragments with increasing size, it was found that MAdV-1 could tolerate an insertion up to 3.3 kb. Collectively, a replication-competent MAdV-1 vector system was established, which simplified procedures for the change of transgene or modification of E1, fiber, E3, or E4 genes.

Preparation and characterization of cellulose fluorescent material: Experiment and simulation.

The extensive use of fossil based materials has caused serious pollution problems, the full utilization of biomass resources to prepare high value-added new materials is of great significance for the environmental protection and sustainable social development. For this purpose, this study explored the preparation process and molecular dynamics simulation of cellulose fluorescent materials. Firstly, bacterial cellulose was dissolved in a solution of NaOH and urea at low temperature, followed by a solution blending and hot pressing with hyperbranched polyamide. It was found that the addition of hyperbranched polyamide could effectively filled in the internal pores of cellulose hydrogel, thereby enhancing the fluorescence effects and tensile properties, especially the elongation at break of cellulose materials. The optimal amount of hyperbranched polyamide added was 5 wt%. Molecular dynamics simulation showed that the hydrogen bonds and interaction with cellulose increased as the concentration of hyperbranched polyamide increased.

A MYB-related transcription factor regulates effector gene expression in an oomycete pathogen.

Phytophthora pathogens possess hundreds of effector genes that exhibit diverse expression patterns during infection, yet how the expression of effector genes is precisely regulated remains largely elusive. Previous studies have identified a few potential conserved transcription factor binding sites (TFBSs) in the promoters of Phytophthora effector genes. Here, we report a MYB-related protein, PsMyb37, in Phytophthora sojae, the major causal agent of root and stem rot in soybean. Yeast one-hybrid and electrophoretic mobility shift assays showed that PsMyb37 binds to the TACATGTA motif, the most prevalent TFBS in effector gene promoters. The knockout mutant of PsMyb37 exhibited significantly reduced virulence on soybean and was more sensitive to oxidative stress. Consistently, transcriptome analysis showed that numerous effector genes associated with suppressing plant immunity or scavenging reactive oxygen species were down-regulated in the PsMyb37 knockout mutant during infection compared to the wild-type P. sojae. Several promoters of effector genes were confirmed to drive the expression of luciferase in a reporter assay. These results demonstrate that a MYB-related transcription factor contributes to the expression of effector genes in P. sojae.

Identification and Verification of Endoplasmic Reticulum Stress-Related Genes as Novel Signatures for Osteoarthritis Diagnosis and Therapy: A Bioinformatics Analysis-Oriented Pilot Study.

BACKGROUND AND PURPOSE: Endoplasmic reticulum stress (ERS) has been reported to be closely associated with the development of osteoarthritis (OA), but the underlying mechanisms are not fully delineated. The present study was designed to investigate the involvement of ERS-related genes in regulating OA progression. METHODS: The expression profiles of OA patients and normal people were downloaded from the gene expression omnibus (GEO) database. The differentially expressed genes (DEGs) in datasets GSE55457 and GSE55235 were screened and identified by R software with the construction of the protein-protein interaction (PPI) networks. Through the STRING and Venn diagram analysis, hub ERS-related genes were obtained. Gene ontology (GO) and kyoto encyclopedia of genes and genomes (KEGG) enrichment analyses were performed. Biomarkers with high diagnostic values of osteoarthritis (OA) were studied. The hematoxylin and eosin (H&E) staining and micro-CT were applied to evaluate the establishment of the OA model. The expression levels of biomarkers were validated with the use of reverse transcription­quantitative polymerase chain reaction (RT-qPCR) and western blot. Finally, we evaluated the correlations of hub ERS-related genes with the immune infiltration cells via the CIBERSORT algorithm. RESULTS: A total of 60 downregulated and 52 upregulated DEGs were identified, and the following GO and KEGG pathway analyses verified that those DEGs were mainly enriched in biological process (BP), cellular component (CC), molecular function (MF), and inflammation-associated signal pathways. Interestingly, among all the DEGs, six ER stress-associated genes, including activating transcription factor 3 (ATF3), DEAD-Box Helicase 3 X-Linked (DDX3X), AP-1 transcription factor subunit (JUN), eukaryotic initiation factor 4 (EIF4A1), KDEL endoplasmic reticulum protein retention receptor 3 (KDELR3), and vascular endothelial growth factor A (VEGFA), were found to be closely associated with OA progression, and the following RT-qPCR and Western Blot analysis confirmed that DDX3X, JUN, and VEGFA were upregulated, whereas KDELR3, EIF4A1, and ATF3 were downregulated in OA rats tissues compared to the normal tissues, which were in accordance with our bioinformatics findings. Furthermore, our receiver operating characteristic (ROC) curve analysis verified that the above six ER stress-associated genes could be used as ideal biomarkers for OA diagnosis and those genes also potentially regulated immune responses by influencing the biological functions of mast cells and macrophages. CONCLUSION: Collectively, the present study firstly identified six ER stress-associated genes (ATF3, DDX3X, JUN, EIF4A1, KDELR3, and VEGFA) that may play critical role in regulating the progression of OA.

Complete telomere-to-telomere genomes uncover virulence evolution conferred by chromosome fusion in oomycete plant pathogens.

Variations in chromosome number are occasionally observed among oomycetes, a group that includes many plant pathogens, but the emergence of such variations and their effects on genome and virulence evolution remain ambiguous. We generated complete telomere-to-telomere genome assemblies for Phytophthora sojae, Globisporangium ultimum, Pythium oligandrum, and G. spinosum. Reconstructing the karyotype of the most recent common ancestor in Peronosporales revealed that frequent chromosome fusion and fission drove changes in chromosome number. Centromeres enriched with Copia-like transposons may contribute to chromosome fusion and fission events. Chromosome fusion facilitated the emergence of pathogenicity genes and their adaptive evolution. Effectors tended to duplicate in the sub-telomere regions of fused chromosomes, which exhibited evolutionary features distinct to the non-fused chromosomes. By integrating ancestral genomic dynamics and structural predictions, we have identified secreted Ankyrin repeat-containing proteins (ANKs) as a novel class of effectors in P. sojae. Phylogenetic analysis and experiments further revealed that ANK is a specifically expanded effector family in oomycetes. These results revealed chromosome dynamics in oomycete plant pathogens, and provided novel insights into karyotype and effector evolution.

Chiral Pyclen-Based Heptadentate Chelates as Highly Stable MRI Contrast Agents.

In recent years, pyclen-based complexes have attracted a great deal of interest as magnetic resonance imaging (MRI) contrast agents (CAs) and luminescent materials, as well as radiopharmaceuticals. Remarkably, gadopiclenol, a Gd(III) bishydrated complex featuring a pyclen-based heptadentate ligand, received approval as a novel contrast agent for clinical MRI application in 2022. To maximize stability and efficiency, two novel chiral pyclen-based chelators and their complexes were developed in this study. Gd-X-PCTA-2 showed significant enhancements in both thermodynamic and kinetic stabilities compared to those of the achiral parent derivative Gd-PCTA. 1H NMRD profiles reveal that both chiral gadolinium complexes (Gd-X-PCTA-1 and Gd-X-PCTA-2) have a higher relaxivity than Gd-PCTA, while variable-temperature 17O NMR studies show that the two inner-sphere water molecules have distinct residence times τMa and τMb. Furthermore, in vivo imaging demonstrates that Gd-X-PCTA-2 enhances the signal in the heart and kidneys of the mice, and the chiral Gd complexes exhibit the ability to distinguish between tumors and normal tissues in a 4T1 mouse model more efficiently than that of the clinical agent gadobutrol. Biodistribution studies show that Gd-PCTA and Gd-X-PCTA-2 are primarily cleared by a renal pathway, with 24 h residues of Gd-X-PCTA-2 in the liver and kidney being lower than those of Gd-PCTA.

Secular trends of population-attributable fractions of obesity for hypertension among US population by sex and race/ethnicity: Analysis from NHANES 1999-2018.

Obesity is a major risk factor of hypertension, therefore quantifying the contribution of obesity to hypertension is necessary. The current study aimed to investigate the changes in population-attributable fractions (PAFs) of hypertension associated with general obesity and abdominal obesity over the recent 2 decades among the US population, as well as important sub-populations. This report was performed based on national-level cross-sectional data for 46,535 adults aged 18 years and older and 20,745 children aged 8-17 from the US National Health and Nutrition Examination Survey 1999-2018. The PAFs of hypertension due to general obesity and abdominal obesity were calculated by sex, race/ethnicity, and survey year. The linear regression analysis was used to evaluate the secular trends of PAFs over the years. The prevalence of general obesity and abdominal obesity presented significantly increasing trends during the past 2 decades in the US. The PAFs of hypertension due to general obesity increased steadily from 11.9 % to 15.1 % in women with a slope of 0.38 % (95 % CI: 0.31 - 0.45 %) and from 8.4 % to 13.4 % in men with a slope of 0.46 % (95 % CI: 0.36 - 0.56 %). Similar increasing trends were also observed for the PAFs due to abdominal obesity in both women and men. Additionally, there were significantly different trends of PAFs in various races/ethnicities. Over the past 2 decades, the contributions of obesity to hypertension were gradually rising among US population, which emphasizes the importance of controlling weight to further reduce the burden of hypertension.

METTL14 downregulation drives S100A4+ monocyte-derived macrophages via MyD88/NF-κB pathway to promote MAFLD progression.

Without intervention, a considerable proportion of patients with metabolism-associated fatty liver disease (MAFLD) will progress from simple steatosis to metabolism-associated steatohepatitis (MASH), liver fibrosis, and even hepatocellular carcinoma. However, the molecular mechanisms that control progressive MAFLD have yet to be fully determined. Here, we unraveled that the expression of the N6-methyladenosine (m6A) methyltransferase METTL14 is remarkably downregulated in the livers of both patients and several murine models of MAFLD, whereas hepatocyte-specific depletion of this methyltransferase aggravated lipid accumulation, liver injury, and fibrosis. Conversely, hepatic Mettl14 overexpression alleviated the above pathophysiological changes in mice fed on a high-fat diet (HFD). Notably, in vivo and in vitro mechanistic studies indicated that METTL14 downregulation decreased the level of GLS2 by affecting the translation efficiency mediated by YTHDF1 in an m6A-depedent manner, which might help to form an oxidative stress microenvironment and accordingly recruit Cx3cr1+Ccr2+ monocyte-derived macrophages (Mo-macs). In detail, Cx3cr1+Ccr2+ Mo-macs can be categorized into M1-like macrophages and S100A4-positive macrophages and then further activate hepatic stellate cells (HSCs) to promote liver fibrosis. Further experiments revealed that CX3CR1 can activate the transcription of S100A4 via CX3CR1/MyD88/NF-κB signaling pathway in Cx3cr1+Ccr2+ Mo-macs. Restoration of METTL14 or GLS2, or interfering with this signal transduction pathway such as inhibiting MyD88 could ameliorate liver injuries and fibrosis. Taken together, these findings indicate potential therapies for the treatment of MAFLD progression.

Redirect Tropism of Fowl Adenovirus 4 Vector by Modifying Fiber2 with Variable Domain of Heavy-Chain Antibody.

The variable domain of a heavy-chain antibody (VHH) has the potential to be used to redirect the cell tropism of adenoviral vectors. Here, we attempted to establish platforms to simplify the screening of VHHs for their specific targeting function when being incorporated into the fiber of adenovirus. Both fowl adenovirus 4 (FAdV-4) and simian adenovirus 1 (SAdV-1) have two types of fiber, one of which is dispensable for virus propagation and is a proper site for VHH display. An intermediate plasmid, pMD-FAV4Fs, was constructed as the start plasmid for FAdV-4 fiber2 modification. Foldon from phage T4 fibritin, a trigger for trimerization, was employed to bridge the tail/shaft domain of fiber2 and VHHs against human CD16A, a key membrane marker of natural killer (NK) cells. Through one step of restriction-assembly, the modified fiber2 was transferred to the adenoviral plasmid, which was linearized and transfected to packaging cells. Five FAdV-4 viruses carrying the GFP gene were finally rescued and amplified, with three VHHs being displayed. One recombinant virus, FAdV4FC21-EG, could hardly transduce human 293 or Jurkat cells. In contrast, when it was used at a multiplicity of infection of 1000 viral particles per cell, the transduction efficiency reached 51% or 34% for 293 or Jurkat cells expressing exogenous CD16A. Such a strategy of fiber modification was transplanted to the SAdV-1 vector to construct SAdV1FC28H-EG, which moderately transduced primary human NK cells while the parental virus transduced none. Collectively, we reformed the strategy of integrating VHH to fiber and established novel platforms for screening VHHs to construct adenoviral vectors with a specific tropism.

Theoretical study on the effect of torsional deformation on WTe2 as a cathode material for calcium ion batteries.

CONTEXT: In this study, the electronic structure and diffusion barrier of the Ca-adsorbed WTe2 system under different torsion angles were calculated based on the first-principles method. The results show that the structure and properties of the pure WTe2 system and Ca-adsorbed WTe2 system are affected by torsional deformation. When the torsion angle is 6°, the intrinsic WTe2 changes from a direct band gap to an indirect band gap. The torsional deformation does not change the metallicity of the Ca-adsorbed WTe2 system. The Ca-d state electrons contribute to the electron density of WTe2. The calculation of the diffusion barrier shows that the torsion deformation promotes the diffusion of calcium on the surface of WTe2. This study provides a theoretical basis for the regulation of electrode materials. METHODS: In this study, Materials Studio 8.0 software was used to construct the WTe2 model and Ca-adsorbed WTe2 model, and CASTEP module was used for first-principles calculation.

Dual-network carboxymethyl chitosan conductive hydrogels for multifunctional sensors and high-performance triboelectric nanogenerators.

With the development of technology, there is a growing demand for wearable electronics that can fulfill different application scenarios. Hydrogel-based sensors are considered ideal candidates for realizing multifunctional wearable flexible devices. However, there are great challenges in preparing hydrogel-based sensors with both superior mechanical and electrical properties. Herein, we report a composite conductive hydrogel prepared by using a dynamically crosslinked carboxymethyl chitosan network and a covalently crosslinked polymer network, and carboxylated carbon nanotubes as conductive filler. The carboxymethyl chitosan-based hydrogels had excellent mechanical properties and strength (tensile strength of 475.4 kPa, and compressive strength of 1.9 MPa) and ultra-high conductivity (0.19 S·cm-1). Based on the above characteristics, the hydrogel could accurately identify the movement signals of the human body and different writing signals, and achieve encrypted transmission of signals, broadening the application scenarios. In addition, a triboelectric nanogenerator (TENG) was fabricated based on the hydrogel, which had an outstanding output performance with open-circuit voltage of 336 V, short-circuit current of 18 µA, transferred charge of 52 nC and maximum power density of 340 mW·m-2, and could power small devices. This work is expected to provide new ideas for the development of self-powered, multi-functional wearable, and flexible polysaccharide-based devices.

Macromers for Encapsulating Perovskite Photovoltaics and Achieving High Stability.

Perovskite solar cells (pero-SCs) are highly unstable even under trace water. Although the blanket encapsulation (BE) strategy applied in the industry can effectively block moisture invasion, the commercial UV-curable adhesives (UVCAs) for BE still trigger power conversion efficiency deterioration, and the degradation mechanism remains unknown. For the first time, the functions of commercial UVCAs are revealed in BE-processed pero-SCs, where the small-sized monomer easily permeates to the perovskite surface, forming an insulating barrier to block charge extraction, while the high-polarity moiety can destroy perovskite lattice. To solve these problems, a macromer, named PIBA is carefully designed, by grafting two acrylate terminal groups on the highly gastight polyisobutylene and realizes an increased molecular diameter as well as avoided high-polarity groups. The PIBA macromer can stabilize on pero-SCs and then sufficiently crosslink, forming a compact and stable network under UV light without sacrificing device performance during the BE process. The resultant BE devices show negligible efficiency loss after storage at 85% relative humidity for 2000 h. More importantly, these devices can even reach ISO 20653:2013 Degrees of protection IPX7 standard when immersed in one-meter-deep water. This BE strategy shows good universality in enhancing the moisture stability of pero-SCs, irrespective of the perovskite composition or device structure.

Yeast Bxi1/Ybh3 mediates conserved mitophagy and apoptosis in yeast and mammalian cells: convergence in Bcl-2 family.

The process of degrading unwanted or damaged mitochondria by autophagy, called mitophagy, is essential for mitochondrial quality control together with mitochondrial apoptosis. In mammalian cells, pan-Bcl-2 family members including conical Bcl-2 members and non-conical ones are involved in and govern the two processes. We have illustrated recently the BH3 receptor Hsp70 interacts with Bim to mediate both apoptosis and mitophagy. However, whether similar pathways exist in lower eukaryotes where conical Bcl-2 members are absent remained unclear. Here, a specific inhibitor of the Hsp70-Bim PPI, S1g-10 and its analogs were used as chemical tools to explore the role of yeast Bxi1/Ybh3 in regulating mitophagy and apoptosis. Using Om45-GFP processing assay, we illustrated that yeast Ybh3 mediates a ubiquitin-related mitophagy pathway in both yeast and mammalian cells through association with Hsp70, which is in the same manner with Bim. Moreover, by using Bax/Bak double knockout MEF cells, Ybh3 was identified to induce apoptosis through forming oligomerization to trigger mitochondrial outer membrane permeabilization (MOMP) like Bax. We not only illustrated a conserved ubiquitin-related mitophagy pathway in yeast but also revealed the multi-function of Ybh3 which combines the function of BH3-only protein and multi-domain Bax protein as one.

Alternating 3rd- to 2nd-Order Charge Reaction Kinetics on Bismuth Vanadate Photoanodes with Ultrathin Bismuth Metal-Organic-Frameworks.

The most challenging obstacle for photocatalysts to efficiently harvest solar energy is the sluggish surface redox reaction (e. g., oxygen evolution reaction, OER) kinetics, which is believed to originate from interface catalysis rather than the semiconductor photophysics. In this work, we developed a light-modulated transient photocurrent (LMTPC) method for investigating surface charge accumulation and reaction on the W-doped bismuth vanadate (W : BiVO4) photoanodes during photoelectrochemical water oxidation. Under illuminating conditions, the steady photocurrent corresponds to the charge transfer rate/kinetics, while the integration of photocurrent (I~t) spikes during the dark period is regarded as the charge density under illumination. Quantitative analysis of the surface hole densities and photocurrents at 0.6 V vs. reversible hydrogen electrode results in an interesting rate-law kinetics switch: a 3rd-order charge reaction behavior appeared on W : BiVO4, but a 2nd-order charge reaction occurred on W : BiVO4 surface modified with ultrathin Bi metal-organic-framework (Bi-MOF). Consequently, the photocurrent for water oxidation on W : BiVO4/Bi-MOF displayed a 50 % increment. The reaction kinetics alternation with new interface reconstruction is proposed for new mechanism understanding and/or high-performance photocatalytic applications.

Apoptotic extracellular vesicles derived from hypoxia-preconditioned mesenchymal stem cells within a modified gelatine hydrogel promote osteochondral regeneration by enhancing stem cell activity and regulating immunity.

Due to its unique structure, articular cartilage has limited abilities to undergo self-repair after injury. Additionally, the repair of articular cartilage after injury has always been a difficult problem in the field of sports medicine. Previous studies have shown that the therapeutic use of mesenchymal stem cells (MSCs) and their extracellular vesicles (EVs) has great potential for promoting cartilage repair. Recent studies have demonstrated that most transplanted stem cells undergo apoptosis in vivo, and the apoptotic EVs (ApoEVs) that are subsequently generated play crucial roles in tissue repair. Additionally, MSCs are known to exist under low-oxygen conditions in the physiological environment, and these hypoxic conditions can alter the functional and secretory properties of MSCs as well as their secretomes. This study aimed to investigate whether ApoEVs that are isolated from adipose-derived MSCs cultured under hypoxic conditions (hypoxic apoptotic EVs [H-ApoEVs]) exert greater effects on cartilage repair than those that are isolated from cells cultured under normoxic conditions. Through in vitro cell proliferation and migration experiments, we demonstrated that H-ApoEVs exerted enhanced effects on stem cell proliferation, stem cell migration, and bone marrow derived macrophages (BMDMs) M2 polarization compared to ApoEVs. Furthermore, we utilized a modified gelatine matrix/3D-printed extracellular matrix (ECM) scaffold complex as a carrier to deliver H-ApoEVs into the joint cavity, thus establishing a cartilage regeneration system. The 3D-printed ECM scaffold provided mechanical support and created a microenvironment that was conducive to cartilage regeneration, and the H-ApoEVs further enhanced the regenerative capacity of endogenous stem cells and the immunomodulatory microenvironment of the joint cavity; thus, this approach significantly promoted cartilage repair. In conclusion, this study confirmed that a ApoEVs delivery system based on a modified gelatine matrix/3D-printed ECM scaffold together with hypoxic preconditioning enhances the functionality of stem cell-derived ApoEVs and represents a promising approach for promoting cartilage regeneration.

Phytochrome-interacting factors play shared and distinct roles in regulating shade avoidance responses in Populus trees.

Plants adjust their growth and development in response to changing light caused by canopy shade. The molecular mechanisms underlying shade avoidance responses have been widely studied in Arabidopsis and annual crop species, yet the shade avoidance signalling in woody perennial trees remains poorly understood. Here, we first showed that PtophyB1/2 photoreceptors serve conserved roles in attenuating the shade avoidance syndrome (SAS) in poplars. Next, we conducted a systematic identification and characterization of eight PtoPIF genes in Populus tomentosa. Knocking out different PtoPIFs led to attenuated shade responses to varying extents, whereas overexpression of PtoPIFs, particularly PtoPIF3.1 and PtoPIF3.2, led to constitutive SAS phenotypes under normal light and enhanced SAS responses under simulated shade. Notably, our results revealed that distinct from Arabidopsis PIF4 and PIF5, which are major regulators of SAS, the Populus homologues PtoPIF4.1 and PtoPIF4.2 seem to play a minor role in controlling shade responses. Moreover, we showed that PtoPIF3.1/3.2 could directly activate the expression of the auxin biosynthetic gene PtoYUC8 in response to shade, suggesting a conserved PIF-YUC-auxin pathway in modulating SAS in tree. Overall, our study provides insights into shared and divergent functions of PtoPIF members in regulating various aspects of the SAS in Populus.