The Brachypodium distachyon DREB transcription factor BdDREB-39 confers oxidative stress tolerance in transgenic tobacco.

Key message BdDREB-39 is a DREB/CBF transcription factor, localized in the nucleus with transactivation activity, and BdDREB-39-overexpressing transgenic yeasts and tobacco enhanced the tolerance to oxidative stress.Abstract The DREB/CBF transcription factors are generally recognized to play an important factor in plant growth, development and response to various abiotic stresses. However, the mechanism of DREB/CBFs in oxidative stress response is largely unknown. This study isolated a DREB/CBF gene BdDREB-39 from Brachypodium distachyon (B. distachyon). Multiple sequence alignment and phylogenetic analysis showed that BdDREB-39 was closely related to the DREB proteins of oats, barley, wheat and rye and therefore its study can provide a reference for the excavation and genetic improvement of BdDREB-39 or its homologs in its closely related species. The transcript levels of BdDREB-39 were significantly up-regulated under H2O2 stress. BdDREB-39 was localised in the nucleus and functioned as a transcriptional activator. Overexpression of BdDREB-39 enhanced H2O2 tolerance in yeast. Transgenic tobaccos with BdDREB-39 had higher germination rates, longer root, better growth status, lesser reactive oxygen species (ROS) and malondialdehyde (MDA), and higher superoxide dismutase (SOD) and peroxidase (POD) activities than wild type (WT). The expression levels of ROS-related and stress-related genes were improved by BdDREB-39. In summary, these results revealed that BdDREB-39 can improve the viability of tobacco by regulating the expression of ROS and stress-related genes, allowing transgenic tobacco to accumulate lower levels of ROS and reducing the damage caused by ROS to cells. The BdDREB-39 gene has the potential for developing plant varieties tolerant to stress.

Multilayered Shape-Morphing Scaffolds with a Hierarchical Structure for Uterine Tissue Regeneration.

Owing to dysfunction of the uterus, millions of couples around the world suffer from infertility. Different from conventional treatments, tissue engineering provides a new and promising approach to deal with difficult problems such as human tissue or organ failure. Adopting scaffold-based tissue engineering, three-dimensional (3D) porous scaffolds in combination with stem cells and appropriate biomolecules may be constructed for uterine tissue regeneration. In this study, a hierarchical tissue engineering scaffold, which mimicked the uterine tissue structure and functions, was designed, and the biomimicking scaffolds were then successfully fabricated using solvent casting, layer-by-layer assembly, and 3D bioprinting techniques. For the multilayered, hierarchical structured scaffolds, poly(l-lactide-co-trimethylene carbonate) (PLLA-co-TMC, "PLATMC" in short) and poly(lactic acid-co-glycolic acid) (PLGA) blends were first used to fabricate the shape-morphing layer of the scaffolds, which was to mimic the function of myometrium in uterine tissue. The PLATMC/PLGA polymer blend scaffolds were highly stretchable. Subsequently, after etching of the PLATMC/PLGA surface and employing estradiol (E2), polydopamine (PDA), and hyaluronic acid (HA), PDA@E2/HA multilayer films were formed on PLATMC/PLGA scaffolds to build an intelligent delivery platform to enable controlled and sustained release of E2. The PDA@E2/HA multilayer films also improved the biological performance of the scaffold. Finally, a layer of bone marrow-derived mesenchymal stem cell (BMSC)-laden hydrogel [which was a blend of gelatin methacryloyl (GelMA) and gelatin (Gel)] was 3D printed on the PDA@E2/HA multilayer films of the scaffold, thereby completing the construction of the hierarchical scaffold. BMSCs in the GelMA/Gel hydrogel layer exhibited excellent cell viability and could spread and be released eventually upon biodegradation of the GelMA/Gel hydrogel. It was shown that the hierarchically structured scaffolds could evolve from the initial flat shape into the tubular structure completely in an aqueous environment at 37 °C, fulfilling the requirement for curved scaffolds for uterine tissue engineering. The biomimicking scaffolds with a hierarchical structure and curved shape, high stretchability, and controlled and sustained E2 release appear to be very promising for uterine tissue regeneration.

Targeting IL-12 family cytokines: A potential strategy for type 1 and type 2 diabetes mellitus.

Diabetes is a common metabolic disease characterized by an imbalance in blood glucose levels. The pathogenesis of diabetes involves the essential role of cytokines, particularly the IL-12 family cytokines. These cytokines, which have a similar structure, play multiple roles in regulating the immune response. Recent studies have emphasized the importance of IL-12 family cytokines in the development of both type 1 and type 2 diabetes mellitus. As a result, they hold promise as potential therapeutic targets for the treatment of these conditions. This review focuses on the potential of targeting IL-12 family cytokines for diabetes therapy based on their roles in the pathogenesis of both types of diabetes. We have summarized various therapies that target IL-12 family cytokines, including drug therapy, combination therapy, cell therapy, gene therapy, cytokine engineering therapy, and gut microbiota modulation. By analyzing the advantages and disadvantages of these therapies, we have evaluated their feasibility for clinical application and proposed possible solutions to overcome any challenges. In conclusion, targeting IL-12 family cytokines for diabetes therapy provides updated insights into their potential benefits, such as controlling inflammation, preserving islet ß cells, reversing the onset of diabetes, and impeding the development of diabetic complications.

Hybridized Hierarchical Watermarking and Selective Encryption for Social Image Security.

With the advent of cloud computing and social multimedia communication, more and more social images are being collected on social media platforms, such as Facebook, TikTok, Flirk, and YouTube. The amount of social images produced and disseminated is rapidly increasing. Meanwhile, cloud computing-assisted social media platforms have made social image dissemination more and more efficient. There exists an unstoppable trend of fake/unauthorized social image dissemination. The growth of social image sharing underscores potential security risks for illegal use, such as image forgery, malicious copying, piracy exposure, plagiarism, and misappropriation. Therefore, secure social image dissemination has become urgent and critical on social media platforms. The authors propose a secure scheme for social image dissemination on social media platforms. The main objective is to make a map between the tree structure Haar (TSH) transform and the hierarchical community structure of a social network. First, perform the TSH transform on a social image using social network analysis (SNA). Second, all users in a social media platform are coded using SNA. Third, watermarking and encryption are performed in a compressed domain for protecting social image dissemination. Finally, the encrypted and watermarked contents are delivered to users via a hybrid multicast-unicast scheme. The use of encryption along with watermarking can provide double protection for social image dissemination. The theory analysis and experimental results demonstrate the effectiveness of the proposed scheme.

Enhanced effects of antagomiR-3074-3p-conjugated PEI-AuNPs on the odontogenic differentiation by targeting FKBP9.

The odontogenic differentiation of dental pulp stem cells (DPSCs), which is vital for tooth regeneration, was regulated by various functional molecules. In recent years, a growing body of research has shown that miRNAs play a crucial role in the odontogenic differentiation of human dental pulp stem cells (hDPSCs). However, the mechanisms by which miRNAs regulated odontogenic differentiation of hDPSCs remained unclear, and the application of miRNAs in reparative dentin formation in vivo was also rare. In this study, we first discovered that miR-3074-3p had an inhibitory effect on odontogenic differentiation of hDPSCs and antagomiR-3074-3p-conjugated PEI-AuNPs effectively promoted odontogenic differentiation of hDPSCs in vitro. AntagomiR-3074-3p-conjugated PEI-AuNPs was further applied to the rat pulp-capping model and showed the increased formation of restorative dentin. In addition, the results of lentivirus transfection in vitro suggested that FKBP9 acted as the key target of miR-3074-3p in regulating the odontogenic differentiation of hDPSCs. These findings might provide a new strategy and candidate target for dentin restoration and tooth regeneration.

Prevascularization techniques for dental pulp regeneration: potential cell sources, intercellular communication and construction strategies.

One of the difficulties of pulp regeneration is the rapid vascularization of transplanted engineered tissue, which is crucial for the initial survival of the graft and subsequent pulp regeneration. At present, prevascularization techniques, as emerging techniques in the field of pulp regeneration, has been proposed to solve this challenge and have broad application prospects. In these techniques, endothelial cells and pericytes are cocultured to induce intercellular communication, and the cell coculture is then introduced into the customized artificial vascular bed or induced to self-assembly to simulate the interaction between cells and extracellular matrix, which would result in construction of a prevascularization system, preformation of a functional capillary network, and rapid reconstruction of a sufficient blood supply in engineered tissue after transplantation. However, prevascularization techniques for pulp regeneration remain in their infancy, and there remain unresolved problems regarding cell sources, intercellular communication and the construction of prevascularization systems. This review focuses on the recent advances in the application of prevascularization techniques for pulp regeneration, considers dental stem cells as a potential cell source of endothelial cells and pericytes, discusses strategies for their directional differentiation, sketches the mechanism of intercellular communication and the potential application of communication mediators, and summarizes construction strategies for prevascularized systems. We also provide novel ideas for the extensive application and follow-up development of prevascularization techniques for dental pulp regeneration.

Structure and Properties of Gelatin Methacryloyl (GelMA) Synthesized in Different Reaction Systems.

Gelatin methacryloyl (GelMA) hydrogels have been extensively used for drug delivery and tissue engineering applications due to their good biocompatibility, biodegradability, and controllable photocurable efficiency. Phosphate buffer solution (PBS) is the most widely used reaction system for GelMA synthesis. However, carbonate-bicarbonate buffer solution (CBS) has been tried recently for synthesizing GelMA due to its high reaction efficiency. However, there is a lack of systematic investigation into possible differences in the structure and properties of GelMA synthesized in PBS and CBS, respectively. Therefore, in the current study, GelMA molecules with two degrees of methacryloylation (∼20 and ∼80%) were synthesized under PBS and CBS reaction systems, respectively, in comparable conditions. The results showed that because of the functionalization of methacrylate groups in gelatin chains, which could interfere with the intrachain and interchain interactions, such as hydrogen bonding, the GelMA molecules synthesized in PBS had distinct physical structures and exhibited different properties in comparison with those produced in CBS. GelMA hydrogels synthesized in PBS exhibited higher gel-sol transition temperatures and better photocurable efficiencies, mechanical strength, and biological properties. In contrast, GelMA hydrogels produced in CBS showed advantages in swelling performance and microstructures, such as pore sizes and porosities. In addition, GelMA synthesized in PBS and possessing a high degree of methacryloylation (the "GelMA-PH" polymer) showed great potential for three-dimensional (3D) bioprinting. This focused study has gained helpful new insights into GelMA and can provide guidance on the application of GelMA in 3D printing and tissue engineering.

A novel rapidly mineralized biphasic calcium phosphate with high acid-resistance stability for long-term treatment of dentin hypersensitivity.

OBJECTIVES: Treating dental hypersensitivity (DH) rapidly and maintaining long-term effectiveness remains challenging. We aimed to address this problem by fabricating a novel rapidly mineralized biphasic calcium phosphate (RMBCP), which could rapidly elicit mineralization to form hydroxyapatite (HA) and perform excellent acid-resistant stability, thus effectively blocking the exposed dental tubules and protecting them from acid attack. METHODS: RMBCP was firstly synthesized by precisely adjusting the molar ratio of acetic acid and calcium hydroxide and characterized by X-ray diffraction (XRD), X-ray fluorescence microprobe (XRF), Fourier-transform infrared (FTIR) spectrometer, scanning electron microscope (SEM), and transmission electron microscope (TEM). Subsequently, using a commercialized desensitizing agent, 45S5 bioglass (BG), as the control group, the mineralization performance of RMBCP was investigated in simulated body fluid (SBF), Dulbecco's modified eagle medium (DMEM), and even slightly acidic artificial saliva (pH=6.6). Moreover, the biocompatibility of RMBCP was studied. Finally, the tubule occlusion effect and acid-resistant stability of RMBCP were evaluated in vitro and in vivo. RESULTS: The rapid mineralization behavior of RMBCP could easily adhere to the dentin surface and block the dentinal tubules completely in vitro and in vivo within 7days. RMBCP performed high acid-resistant stability to maintain the long-term therapeutic effect of DH treatment. SIGNIFICANCE: Developing novel bioactive calcium phosphate materials with the ability to trigger mineralization for HA formation rapidly will be an effective strategy for the long-term treatment of dentin hypersensitivity.

Injectable bone cement with magnesium-containing microspheres enhances osteogenesis via anti-inflammatory immunoregulation.

Injectable bone cement is especially useful in minimally invasive surgeries to repair small and irregular bone defects. Amongst different kinds of injectable bone cements, bioactive calcium phosphate bone cement (CPC) has been widely studied due to its biological activity. However, its dense structure and poor biodegradability prevent the ingrowth of living tissue, which leads to undesirable bone regeneration and clinical translation. To address this issue, we prepared bone cement based on Magnesium-containing microspheres (MMSs) that can not only be cured into a 3D porous scaffold but also have controllable biodegradability that continuously provides space for desired tissue ingrowth. Interestingly, magnesium ions released from MMSs cement (MMSC) trigger positive immunomodulation via upregulation of the anti-inflammatory genes IL-10 and M2 macrophage polarization with increased expression of CD206, which is beneficial to osteogenesis. Moreover, the physicochemical properties of MMSC, including heat release, rheology and setting time, can be tuned to meet the requirements of injectable bone cement for clinical application. Using a rat model, we have demonstrated that MMSC promoted osteogenesis via mediation of tissue ingrowth and anti-inflammatory immunomodulation. The study provides a paradigm for the design and preparation of injectable bone cements with 3D porous structures, biodegradability and anti-inflammatory immunoregulation to efficiently promote osteogenesis.

Enhanced effect of nano-monetite hydrosol on dentin remineralization and tubule occlusion.

OBJECTIVES: We aim to investigate the dentin tubule occlusion and remineralization potential of a novel nano-monetite hydrosol (nMH). METHODS: First, nano-monetite hydrosol (nMH) was fabricated by homogeneous precipitation method. Then, the effectiveness of toothpaste with nMH on improving remineralization was evaluated by the measurement of tubule occluding ratio and acid-resistant stability compared with dentifrices comprising nano-hydroxyapatite hydrosol (nHH) and bioactive glass (BG). To explain this result, we studied the ions releasing and remineralization based on gelatin scaffold among nMH, nHH and BG. Finally, the cytotoxicity of these three minerals on Human dental pulp stem cells (HDPSCs) was evaluated. RESULTS: Processing for more than 7 days, the toothpaste containing nMH exhibited the significant remineralization potential and acid-resistant compared with two commercial de-sensitive dentifrices comprising nHH and BG. In addition, cytotoxicity test resulted that nMH has good cell compatibility to HDPSCs below extracts concentration of 3.12mg/mL. SIGNIFICANCE: Small size, the release of Ca2+ and PO43- with high concentration, strongly binding on dental surface, and fast transformation to HAp, were all needed in the preparation of effective dentin tubule occluding biomaterials.

Effects of early cold stress on gene expression in Chlamydomonas reinhardtii.

Cold stress imposes a great impact on the growth of nearly all photosynthetic organisms, including Chlamydomonas reinhardtii (C. reinhardtii). Despite prior studies on the mechanism of stress acclimation in plants, little has been done on the early events of cold sensing in C. reinhardtii. Here, we used C. reinhardtii as a model to study early events of cold signal transduction. By analyzing transcriptomic changes of C. reinhardtii exposed to cold, we found that 3471 genes were differentially expressed after 1 h of cold exposure. These genes were associated with a wide range of biological events and processes such as protein synthesis, cell cycle and protein kinase-based phosphorylation. Besides, the promoter of one gene (named as crAP2) which belongs to AP2/EREBP family and was significantly induced by cold was cloned, and functional analysis was conducted using GUS activity analysis through Agrobacterium-mediated transient assay in tobacco leaves.

Phylogenetic and expression analysis of histone acetyltransferases in Brachypodium distachyon.

Histone acetylation is an important post-translational modification in eukaryotes and is regulated by two antagonistic enzymes, namely histone acetyltransferase (HAT) and histone deacetylase (HDAC). However, little has been done on the HAT superfamily in Brachypodium distachyon (B. distachyon), a new model plant of Poaceae. In this study, eight HATs were identified from B. distachyon and classified into four major families. Subcellular localization analysis showed that a majority of BdHATs were predominantly localized in the nucleus. Syntenic and phylogenetic analysis indicated there may be two common ancestral CREB-binding protein (p300/CBP, HAC) genes prior to the separation of monocots and dicots. Expression analysis revealed that the potential roles of BdHATs in B. distachyon development and responses to four abiotic stresses. Protein-protein network analysis identified some potential interactive genes with BdHATs. Thus, our results will provide solid basis for further study the function of HAT genes in B. distachyon and other monocot plants.

Zn2+-loaded cellulose beads stabilized by chitosan and prepared via freeze-drying for removing human testosterone in plasma.

Hemoperfusion using metal ion affinity adsorbent is a promising method to remove human testosterone in plasma. Due to the leakage of metal ion from the adsorbents, there is no metal ion affinity adsorbent for hemoperfusion. In this study, chitosan was used to coat the adsorbent for preventing the leakage of Zn2+ loaded. Meanwhile, freeze-drying method was used to enhance adsorption capacity of Zn2+-loaded cellulose beads for testosterone. The results indicate that after the adsorbent was coated by 0.02% chitosan solution, the highest adsorption percentage reached 48%, during adsorption, the Zn2+ concentration in plasma did not increase; the adsorption capacity of the adsorbent can be significantly enhanced by freeze-drying. The results may be caused by porosity of the adsorbent enlarged via freeze-drying and improved stability by coating with chitosan. In addition, the adsorbent shows better selectivity and storage stability and could be a potential adsorbent to treat prostate cancer.

Expansion and stress responses of AP2/EREBP superfamily in Brachypodium distachyon.

APETALA2/ethylene-responsive element binding protein (AP2/EREBP) transcription factors constitute one of the largest and most conserved gene families in plant, and play essential roles in growth, development and stress response. Except a few members, the AP2/EREBP family has not been characterized in Brachypodium distachyon, a model plant of Poaceae. We performed a genome-wide study of this family in B. distachyon by phylogenetic analyses, transactivation assays and transcript profiling. A total of 149 AP2/EREBP genes were identified and divided into four subfamilies, i.e., ERF (ethylene responsive factor), DREB (dehydration responsive element binding gene), RAV (related to ABI3/VP) and AP2. Tandem duplication was a major force in expanding B. distachyon AP2/EREBP (BdAP2/EREBP) family. Despite a significant expansion, genomic organizations of BdAP2/EREBPs were monotonous as the majority of them, except those of AP2 subfamily, had no intron. An analysis of transcription activities of several closely related and duplicated BdDREB genes showed their functional divergence and redundancy in evolution. The expression of BdAP2/EREBPs in different tissues and the expression of DREB/ERF subfamilies in B. distachyon, wheat and rice under abiotic stresses were investigated by next-generation sequencing and microarray profiling. Our results are valuable for further function analysis of stress tolerant AP2/EREBP genes in B. distachyon.

Genome-wide identification and analysis of MAPK and MAPKK gene families in Brachypodium distachyon.

MAPK cascades are universal signal transduction modules and play important roles in plant growth, development and in response to a variety of biotic and abiotic stresses. Although MAPKs and MAPKKs have been systematically investigated in several plant species including Arabidopsis, rice and poplar, no systematic analysis has been conducted in the emerging monocot model plant Brachypodium distachyon. In the present study, a total of 16 MAPK genes and 12 MAPKK genes were identified from B. distachyon. An analysis of the genomic evolution showed that both tandem and segment duplications contributed significantly to the expansion of MAPK and MAPKK families. Evolutionary relationships within subfamilies were supported by exon-intron organizations and the architectures of conserved protein motifs. Synteny analysis between B. distachyon and the other two plant species of rice and Arabidopsis showed that only one homolog of B. distachyon MAPKs was found in the corresponding syntenic blocks of Arabidopsis, while 13 homologs of B. distachyon MAPKs and MAPKKs were found in that of rice, which was consistent with the speciation process of the three species. In addition, several interactive protein pairs between the two families in B. distachyon were found through yeast two hybrid assay, whereas their orthologs of a pair in Arabidopsis and other plant species were not found to interact with each other. Finally, expression studies of closely related family members among B. distachyon, Arabidopsis and rice showed that even recently duplicated representatives may fulfill different functions and be involved in different signal pathways. Taken together, our data would provide a foundation for evolutionary and functional characterization of MAPK and MAPKK gene families in B. distachyon and other plant species to unravel their biological roles.

Genome Wide Analysis of Nucleotide-Binding Site Disease Resistance Genes in Brachypodium distachyon.

Nucleotide-binding site (NBS) disease resistance genes play an important role in defending plants from a variety of pathogens and insect pests. Many R-genes have been identified in various plant species. However, little is known about the NBS-encoding genes in Brachypodium distachyon. In this study, using computational analysis of the B. distachyon genome, we identified 126 regular NBS-encoding genes and characterized them on the bases of structural diversity, conserved protein motifs, chromosomal locations, gene duplications, promoter region, and phylogenetic relationships. EST hits and full-length cDNA sequences (from Brachypodium database) of 126 R-like candidates supported their existence. Based on the occurrence of conserved protein motifs such as coiled-coil (CC), NBS, leucine-rich repeat (LRR), these regular NBS-LRR genes were classified into four subgroups: CC-NBS-LRR, NBS-LRR, CC-NBS, and X-NBS. Further expression analysis of the regular NBS-encoding genes in Brachypodium database revealed that these genes are expressed in a wide range of libraries, including those constructed from various developmental stages, tissue types, and drought challenged or nonchallenged tissue.