Regulated cleavage and translocation of FERONIA control immunity in Arabidopsis roots.

Plant roots exhibit localized immunity (LI) mainly in the transition zone (TZ) and elongation zone (EZ). Plasma membrane-localized receptor-like kinases (RLKs) can mediate the plant's response to rhizosphere bacteria. However, how RLKs are involved in triggering LI in roots remains unclear. Here we identified dual actions for the RLK FERONIA (FER) in the LI response of Arabidopsis (Arabidopsis thaliana). The FER cytoplasmic domain is cleaved and translocated to the nucleus (FERN) to activate LI in the TZ and EZ in response to colonization by beneficial and pathogenic bacteria. In the absence or cessation of bacterial infection, full-length FER is plasma membrane-localized to maintain growth. Upon colonization and invasion by a high titre of bacteria, mature RAPID ALKALINIZATION FACTOR23 peptide accumulates and activates the matrix metalloproteinase At2-MMP, which triggers FER cytoplasmic domain cleavage specifically in the TZ and EZ to activate LI. This work demonstrates that two molecular forms of a single RLK balance growth and immunity via LI activation in Arabidopsis roots.

Hyaluronic acid methacrylate/Pluronic F127 hydrogel enhanced with spermidine-modified mesoporous polydopamine nanoparticles for efficient synergistic periodontitis treatment.

Bacterial infection, reactive oxygen species (ROS) accumulation, and persistent inflammation pose significant challenges in the treatment of periodontitis. However, the current single-modal strategy makes achieving the best treatment effect difficult. Herein, we developed a double-network hydrogel composed of Pluronic F127 (PF-127) and hyaluronic acid methacrylate (HAMA) loaded with spermidine-modified mesoporous polydopamine nanoparticles (M@S NPs). The PF-127/HAMA/M@S (PH/M@S) hydrogel was injectable and exhibited thermosensitivity and photocrosslinking capabilities, which enable it to adapt to the irregular shape of periodontal pockets. In vitro, the PH/M@S displayed multiple therapeutic effects, such as photothermal antibacterial activity, a high ROS scavenging capacity, and anti-inflammatory effects, which are beneficial for the multimodal treatment of periodontitis. The underlying anti-inflammatory mechanism of this hydrogel involves suppression of the extracellular regulated protein kinase 1/2 and nuclear factor kappa-B signalling pathways. Furthermore, in lipopolysaccharide-stimulated macrophage conditioned media, the PH/M@S effectively restored the osteogenic differentiation potential. In a rat model of periodontitis, the PH/M@S effectively reduced the bacterial load, relieved local inflammation and inhibited alveolar bone resorption. Collectively, these findings highlight the versatile functions of the PH/M@S, including photothermal antibacterial activity, ROS scavenging, and anti-inflammatory effects, indicating that this hydrogel is a promising multifunctional filling material for the treatment of periodontitis.

Multifunctional bilayer nanofibrous membrane enhances periodontal regeneration via mesenchymal stem cell recruitment and macrophage polarization.

The continuous stimulation of periodontitis leads to a decrease in the number of stem cells within the lesion area and significantly impairing their regenerative capacity. Therefore, it is crucial to promote stem cell homing and regulate the local immune microenvironment to suppress inflammation for the regeneration of periodontitis-related tissue defects. Here, we fabricated a novel multifunctional bilayer nanofibrous membrane using electrospinning technology. The dense poly(caprolactone) (PCL) nanofibers served as the barrier layer to resist epithelial invasion, while the polyvinyl alcohol/chitooligosaccharides (PVA/COS) composite nanofiber membrane loaded with calcium beta-hydroxy-beta-methylbutyrate (HMB-Ca) acted as the functional layer. Material characterization tests revealed that the bilayer nanofibrous membrane presented desirable mechanical strength, stability, and excellent cytocompatibility. In vitro, PCL@PVA/COS/HMB-Ca (P@PCH) can not only directly promote rBMSCs migration and differentiation, but also induce macrophage toward pro-healing (M2) phenotype-polarization with increasing the secretion of anti-inflammatory and pro-healing cytokines, thus providing a favorable osteoimmune environment for stem cells recruitment and osteogenic differentiation. In vivo, the P@PCH membrane effectively recruited host MSCs to the defect area, alleviated inflammatory infiltration, and accelerated bone defects repair. Collectively, our data indicated that the P@PCH nanocomposite membrane might be a promising biomaterial candidate for guided tissue regeneration in periodontal applications.

Ankylosing spondylitis prediction using fuzzy K-nearest neighbor classifier assisted by modified JAYA optimizer.

The diagnosis of ankylosing spondylitis (AS) can be complex, necessitating a comprehensive assessment of medical history, clinical symptoms, and radiological evidence. This multidimensional approach can exacerbate the clinical burden and increase the likelihood of diagnostic inaccuracies, which may result in delayed or overlooked cases. Consequently, supplementary diagnostic techniques for AS have become a focal point in clinical research. This study introduces an enhanced optimization algorithm, SCJAYA, which incorporates salp swarm foraging behavior with cooperative predation strategies into the JAYA algorithm framework, noted for its robust optimization capabilities that emulate the evolutionary dynamics of biological organisms. The integration of salp swarm behavior is aimed at accelerating the convergence speed and enhancing the quality of solutions of the classical JAYA algorithm while the cooperative predation strategy is incorporated to mitigate the risk of convergence on local optima. SCJAYA has been evaluated across 30 benchmark functions from the CEC2014 suite against 9 conventional meta-heuristic algorithms as well as 9 state-of-the-art meta-heuristic counterparts. The comparative analyses indicate that SCJAYA surpasses these algorithms in terms of convergence speed and solution precision. Furthermore, we proposed the bSCJAYA-FKNN classifier: an advanced model applying the binary version of SCJAYA for feature selection, with the aim of improving the accuracy in diagnosing and prognosticating AS. The efficacy of the bSCJAYA-FKNN model was substantiated through validation on 11 UCI public datasets in addition to an AS-specific dataset. The model exhibited superior performance metrics-achieving an accuracy rate, specificity, Matthews correlation coefficient (MCC), F-measure, and computational time of 99.23 %, 99.52 %, 0.9906, 99.41 %, and 7.2800 s, respectively. These results not only underscore its profound capability in classification but also its substantial promise for the efficient diagnosis and prognosis of AS.

Extracellular matrix stiffness as an energy metabolism regulator drives osteogenic differentiation in mesenchymal stem cells.

The biophysical factors of biomaterials such as their stiffness regulate stem cell differentiation. Energy metabolism has been revealed an essential role in stem cell lineage commitment. However, whether and how extracellular matrix (ECM) stiffness regulates energy metabolism to determine stem cell differentiation is less known. Here, the study reveals that stiff ECM promotes glycolysis, oxidative phosphorylation, and enhances antioxidant defense system during osteogenic differentiation in MSCs. Stiff ECM increases mitochondrial fusion by enhancing mitofusin 1 and 2 expression and inhibiting the dynamin-related protein 1 activity, which contributes to osteogenesis. Yes-associated protein (YAP) impacts glycolysis, glutamine metabolism, mitochondrial dynamics, and mitochondrial biosynthesis to regulate stiffness-mediated osteogenic differentiation. Furthermore, glycolysis in turn regulates YAP activity through the cytoskeletal tension-mediated deformation of nuclei. Overall, our findings suggest that YAP is an important mechanotransducer to integrate ECM mechanical cues and energy metabolic signaling to affect the fate of MSCs. This offers valuable guidance to improve the scaffold design for bone tissue engineering constructs.

[Differentiation of stem cells regulated by biophysical cues].

Stem cells have been regarded with promising application potential in tissue engineering and regenerative medicine due to their self-renewal and multidirectional differentiation abilities. However, their fate is relied on their local microenvironment, or niche. Recent studied have demonstrated that biophysical factors, defined as physical microenvironment in which stem cells located play a vital role in regulating stem cell committed differentiation. In vitro, synthetic physical microenvironments can be used to precisely control a variety of biophysical properties. On this basis, the effect of biophysical properties such as matrix stiffness, matrix topography and mechanical force on the committed differentiation of stem cells was further investigated. This paper summarizes the approach of mechanical models of artificial physical microenvironment and reviews the effects of different biophysical characteristics on stem cell differentiation, in order to provide reference for future research and development in related fields.

A glucose-blue light AND gate-controlled chemi-optogenetic cell-implanted therapy for treating type-1 diabetes in mice.

Exogenous insulin therapy is the mainstay treatment for Type-1 diabetes (T1D) caused by insulin deficiency. A fine-tuned insulin supply system is important to maintain the glucose homeostasis. In this study, we present a designed cell system that produces insulin under an AND gate control, which is triggered only in the presence of both high glucose and blue light illumination. The glucose-sensitive GIP promoter induces the expression of GI-Gal4 protein, which forms a complex with LOV-VP16 in the presence of blue light. The GI-Gal4:LOV-VP16 complex then promotes the expression of UAS-promoter-driven insulin. We transfected these components into HEK293T cells, and demonstrated the insulin was secreted under the AND gate control. Furthermore, we showed the capacity of the engineered cells to improve the blood glucose homeostasis through implantation subcutaneously into Type-1 diabetes mice.

Wnt/ß-catenin plays a dual function in calcium hydroxide induced proliferation, migration, osteogenic differentiation and mineralization in vitro human dental pulp stem cells.

AIM: Calcium hydroxide is the gold standard material for pulp capping and has been widely used in clinical dentistry. Calcium hydroxide promotes proliferation, migration and osteogenic differentiation of dental pulp stem cells (DPSCs). However, the underlying mechanism is not clear. Our study investigated the role of Wnt/ß-catenin pathway in calcium hydroxide-induced proliferation, migration, osteogenic differentiation and mineralization of human DPSCs. METHODOLOGY: Protein and gene expression was detected by western blot (WB), immunofluorescence staining and quantitative real-time PCR (qPCR). Cell viability was analysed using the Cell Counting Kit-8 (CCK-8) assay. Wound-healing assay was used to analyse cell migration. The expression of alkaline phosphatase (ALP) was detected using ALP staining. Mineralization was analysed by alizarin red staining. RESULTS: Calcium hydroxide increased the protein expression of phosphorylated-GSK3ß/GSK3ß, ß-catenin and the gene expression of LEF-1. Inhibition of Wnt/ß-catenin abolished calcium hydroxide-induced proliferation and migration of DPSCs in 24 h. However, incubation with calcium hydroxide for 7 days and 14 days reduced Wnt/ß-catenin signalling. Inhibition of Wnt/ß-catenin promoted calcium hydroxide-induced osteogenic differentiation and mineralization in DPSCs. CONCLUSION: Wnt/ß-catenin pathway plays a dual role in calcium hydroxide-regulated DPSC behaviour. Incubation with calcium hydroxide promoted rapid proliferation and migration of DPSCs, while prolonged incubation negatively regulated osteogenic differentiation and mineralization.

Fluid shear stress promotes periodontal ligament cells proliferation via p38-AMOT-YAP.

Periodontal ligament (PDL) cells are a promising tool for periodontal regeneration therapy. Achieving a sufficient number of PDL cells is essential to PDL regeneration. In our study, appropriate flow shear stress (FSS, 1-6 dyn/cm2) promotes the proliferation of PDL cells. FSS remodels cytoskeleton and focal adhesion in a duration-dependent manner. FSS induces PDL cells to form the actin cap within 10 min, flattens the nuclei, and increases the nuclear pore size, which promotes nuclear translocation of Yes-associated protein (YAP). FSS activates p38, which plays a dual function in YAP regulation. p38 regulates the phosphorylation of Akt and cofilin, as well as induced F-actin polymerization to induce YAP activity. In addition, p38 inhibits pLATS and consecutively regulates angiomotin (AMOT) and YAP phosphorylation. AMOT competitively binds to F-actin and YAP to participate in FSS-mediated YAP nuclear translocation and cell proliferation. Taken collectively, our results provide mechanistic insights into the role of p38-AMOT-YAP in FSS-mediated PDL cells proliferation and indicate potential applications in dental regenerative medicine.

FERONIA is involved in phototropin 1-mediated blue light phototropic growth in Arabidopsis.

Plant shoot phototropism is triggered by the formation of a light-driven auxin gradient leading to bending growth. The blue light receptor phototropin 1 (phot1) senses light direction, but how this leads to auxin gradient formation and growth regulation remains poorly understood. Previous studies have suggested phot1's role for regulated apoplastic acidification, but its relation to phototropin and hypocotyl phototropism is unclear. Herein, we show that blue light can cause phot1 to interact with and phosphorylate FERONIA (FER), a known cell growth regulator, and trigger downstream phototropic bending growth in Arabidopsis hypocotyls. fer mutants showed defects in phototropic growth, similar to phot1/2 mutant. FER also interacts with and phosphorylates phytochrome kinase substrates, the phot1 downstream substrates. The phot1-FER pathway acts upstream of apoplastic acidification and the auxin gradient formation in hypocotyl under lateral blue light, both of which are critical for phototropic bending growth in hypocotyls. Our study highlights a pivotal role of FER in the phot1-mediated phototropic cell growth regulation in plants.

Static magnetic field regulates proliferation, migration, and differentiation of human dental pulp stem cells by MAPK pathway.

Magnetic materials are now commonly used in dental clinics. These materials generally produce a static magnetic field (SMF). While it is known that SMF can affect cells' behaviors such as proliferation, migration, and differentiation, the mechanisms underlying these effects are still unclear. Our study investigates the role of the mitogen-activated protein (MAP) kinase pathway in SMF-induced proliferation, migration, osteogenic/odontogenic differentiation, and mineralization in human dental pulp stem cells (DPSCs). Human DPSCs were exposed to SMF of 1 mT and the phosphorylated MAP kinases were detected by Western blot analysis. Three MAP kinases inhibitors were pre-cultured with DPSCs and exposed to SMF for 24 h. Cell viability was analyzed using Cell Counting Kit-8. Cell migration was tested by a wound healing assay. Osteogenic/odontogenic differentiation was detected by ALP staining assay, ALP and DSPP Western blot analysis. Mineralization was studied by alizarin red staining analysis. SMF activated phosphorylation of c-Jun N-terminal kinase (JNK), P38 and extracellular signal-regulated kinase (ERK). The inhibition of JNK, P38, and ERK signaling decreased SMF-induced proliferation and migration. ERK and P38 play more important roles in SMF-induced ALP staining and protein expression. JNK was vital for SMF-induced DSPP expression. JNK, P38, and ERK all involved in SMF-mediated mineralization. Our study demonstrated that the MAPK pathway regulated SMF-induced proliferation, migration, osteogenic/odontogenic differentiation, and mineralization in human DPSCs.

Purification and Structural Characterization of Dendrobium officinale Polysaccharides and Its Activities.

In this study, Dendrobium officinale polysaccharide (named DOPS-1) was isolated from the stems of Dendrobium officinale by hot-water extraction and purified by using Sephadex G-150 column chromatography. The structural characterization, antioxidant and cytotoxic activity were carried out. Based on the results of HPLC, GC, Congo red experiment, together with periodate oxidation, Smith degradation, SEM, FT-IR, and NMR spectral analysis, it expressed that DOPS-1 was largely composed of mannose, glucose and galacturonic acid in a molar ratio of 3.2 : 1.3 : 1. The molecular weight of DOPS-1 was 1530 kDa and the main chain was composed of (1→4)-ß-D-Glcp, (1→4)-ß-D-Manp and 2-O-acetyl-(1→4)-ß-D-Manp. The measurement results of antioxidant activity showed that DOPS-1 had the strong scavenging activities on hydroxyl radicals, DPPH radicals and superoxide radicals and the high reducing ability in vitro. Moreover, DOPS-1 was cytotoxic to all three human cancer cells of MDA-MB-231, A549 and HepG2.

Rapid electrochemical-biosensor microchip platform for determination of microalbuminuria in CKD patients.

An electrochemical-biosensor (EC-biosensor) microchip consisting of screen-printed electrodes and a double-layer reagent paper detection zone impregnated with amaranth is proposed for the rapid determination of microalbuminuria (MAU) in human urine samples. Under the action of an applied deposition potential, the amaranth is adsorbed on the electrode surface and the subsequent reaction between the modified surface and the MAU content in the urine sample prompts the formation of an inert layer on the electrode surface. The inert layer impedes the transfer of electrons and hence produces a drop in the response peak current, from which the MAU concentration can then be determined. The measurement results obtained for seven artificial urine samples with known MAU concentrations in the range of 0.1-40 mg/dL show that the measured response peak current is related to the MAU concentration with a determination coefficient of R2 = 0.991 in the low concentration range of 0.1-10 mg/dL and R2 = 0.996 in the high concentration range of 10-40 mg/dL. Furthermore, the detection results obtained for 82 actual chronic kidney disease (CKD) patients show an excellent agreement (R2 = 0.988) with the hospital analysis results. Overall, the results confirm that the proposed detection platform provides a convenient and reliable approach for performing sensitive point-of-care testing (POCT) of the MAU content in human urine samples.

RALF1-FERONIA complex affects splicing dynamics to modulate stress responses and growth in plants.

The environmentally responsive signaling pathways that link global transcriptomic changes through alternative splicing (AS) to plant fitness remain unclear. Here, we found that the interaction of the extracellular rapid alkalinization FACTOR 1 (RALF1) peptide with its receptor FERONIA (FER) triggered a rapid and massive RNA AS response by interacting with and phosphorylating glycine-rich RNA binding protein7 (GRP7) to elevate GRP7 nuclear accumulation in Arabidopsis thaliana. FER-dependent GRP7 phosphorylation enhanced its mRNA binding ability and its association with the spliceosome component U1-70K to enable splice site selection, modulating dynamic AS. Genetic reversal of a RALF1-FER-dependent splicing target partly rescued mutants deficient in GRP7. AS of GRP7 itself induced nonsense-mediated decay feedback to the RALF1-FER-GRP7 module, fine-tuning stress responses, and cell growth. The RALF1-FER-GRP7 module provides a paradigm for regulatory mechanisms of RNA splicing in response to external stimuli.

The RALF1-FERONIA Complex Phosphorylates eIF4E1 to Promote Protein Synthesis and Polar Root Hair Growth.

The molecular links between extracellular signals and the regulation of localized protein synthesis in plant cells are poorly understood. Here, we show that in Arabidopsis thaliana, the extracellular peptide RALF1 and its receptor, the FERONIA receptor kinase, promote root hair (RH) tip growth by modulating protein synthesis. We found that RALF1 promotes FERONIA-mediated phosphorylation of eIF4E1, a eukaryotic translation initiation factor that plays a crucial role in the control of mRNA translation rate. Phosphorylated eIF4E1 increases mRNA affinity and modulates mRNA translation and, thus, protein synthesis. The mRNAs targeted by the RALF1-FERONIA-eIF4E1 module include ROP2 and RSL4, which are important regulators of RH cell polarity and growth. RALF1 and FERONIA are expressed in a polar manner in RHs, which facilitate eIF4E1 polar localization and thus may control local ROP2 translation. Moreover, we demonstrated that high-level accumulation of RSL4 exerts negative-feedback regulation of RALF1 expression by directly binding the RALF1 gene promoter, determining the final RH size. Our study reveals that the link between RALF1-FERONIA signaling and protein synthesis constitutes a novel component regulating cell expansion in these polar growing cells.

Cell-Surface-Anchored Ratiometric DNA Tweezer for Real-Time Monitoring of Extracellular and Apoplastic pH.

Precise and dynamic imaging of extracellular pH is one crucial yet challenging task for studying cell physiological and pathological processes. Here, we construct a DNA tweezer to dynamically monitor pH changes of cellular microenvironments. The DNA tweezer contains three key elements: a three-strand ssDNA-frame labeled with cholesterol to anchor it on the cell membrane, a pH-sensitive i-motif sequence in the middle to dynamically control the switch between the "open" and "closed" states of the DNA tweezer, and a pair of FRET fluorophores (rhodamine green and rhodamine red) on the two arms of the tweezer to reflect its state. With cholesterol, a natural component of cell membranes, as an anchoring element, the sensor exhibited high cell-membrane-insertion efficiency and low cytotoxicity. Using the i-motif as a sensing element, it can quickly and reversibly respond to extracellular pH in the pH range of 5.0-7.5 and further perform real-time imaging of cell-surface-pH changes with excellent spatial and temporal resolution. Moreover, apoplastic-pH change during the alkalization process of plant roots caused by rapid-alkalinization factor (RALF1) was directly detected by the sensor, demonstrating the potential applications of the sensor in cell biology, biomedical research, and plant-tissue engineering.

EBP1 nuclear accumulation negatively feeds back on FERONIA-mediated RALF1 signaling.

FERONIA (FER), a plasma membrane receptor-like kinase, is a central regulator of cell growth that integrates environmental and endogenous signals. A peptide ligand rapid alkalinization factor 1 (RALF1) binds to FER and triggers a series of downstream events, including inhibition of Arabidopsis H+-ATPase 2 activity at the cell surface and regulation of gene expression in the nucleus. We report here that, upon RALF1 binding, FER first promotes ErbB3-binding protein 1 (EBP1) mRNA translation and then interacts with and phosphorylates the EBP1 protein, leading to EBP1 accumulation in the nucleus. There, EBP1 associates with the promoters of previously identified RALF1-regulated genes, such as CML38, and regulates gene transcription in response to RALF1 signaling. EBP1 appears to inhibit the RALF1 peptide response, thus forming a transcription-translation feedback loop (TTFL) similar to that found in circadian rhythm control. The plant RALF1-FER-EBP1 axis is reminiscent of animal epidermal growth factor receptor (EGFR) signaling, in which EGF peptide induces EGFR to interact with and phosphorylate EBP1, promoting EBP1 nuclear accumulation to control cell growth. Thus, we suggest that in response to peptide signals, plant FER and animal EGFR use the conserved key regulator EBP1 to control cell growth in the nucleus.

Receptor kinase complex transmits RALF peptide signal to inhibit root growth in Arabidopsis.

A number of hormones work together to control plant cell growth. Rapid Alkalinization Factor 1 (RALF1), a plant-derived small regulatory peptide, inhibits cell elongation through suppression of rhizosphere acidification in plants. Although a receptor-like kinase, FERONIA (FER), has been shown to act as a receptor for RALF1, the signaling mechanism remains unknown. In this study, we identified a receptor-like cytoplasmic kinase (RPM1-induced protein kinase, RIPK), a plasma membrane-associated member of the RLCK-VII subfamily, that is recruited to the receptor complex through interacting with FER in response to RALF1. RALF1 triggers the phosphorylation of both FER and RIPK in a mutually dependent manner. Genetic analysis of the fer-4 and ripk mutants reveals RIPK, as well as FER, to be required for RALF1 response in roots. The RALF1-FER-RIPK interactions may thus represent a mechanism for peptide signaling in plants.

RPN1a negatively regulates ABA signaling in Arabidopsis.

The 26S proteasome selectively regulates key abscisic acid (ABA) signaling proteins, but the physiological functions and mechanisms of RPN1a (a subunit of the 26S proteasome) in ABA signaling remain largely unknown. In this study, we found that the mRNA expression of RPN1a was suppressed by ABA treatment, and that RPN1a protein was expressed abundantly in guard cells. In the presence of ABA, rpn1a mutants showed rapid stomatal closure, low water loss, delayed germination, and inhibited root elongation. In addition, the transcripts of key ABA signaling genes, including ABI5, RD22, RD29A, and RD29B, were upregulated in rpn1a mutant plants in response to ABA. Furthermore, the ABI5 protein level was higher in rpn1a mutants subjected to ABA treatment. Yeast two-hybrid and bimolecular fluorescence complementation assays showed that RPN1a interacts with ABI1. Overall, these findings suggest that RPN1a negatively regulates ABA signaling in Arabidopsis.

Receptor protein kinase FERONIA controls leaf starch accumulation by interacting with glyceraldehyde-3-phosphate dehydrogenase.

Cell expansion is coordinated by several cues, but available energy is the major factor determining growth. Receptor protein kinase FERONIA (FER) is a master regulator of cell expansion, but the details of its control mechanisms are not clear. Here we show that FER interacts with cytosolic enzyme glyceraldehyde-3-phosphate dehydrogenase (GAPDH, GAPC1 and GAPC2), that catalyzes a key reaction in glycolysis, which contributes to energy production. When there is an FER deficiency, there are corresponding decreases in the enzyme activity of GAPDH and increased amounts of starch. More importantly, gapc1/2 mutants mimic fer4 mutants. These data indicate that FER regulated starch content is an evolutionarily conserved function in plants that connects the cell expansion and energy metabolism pathways.