E93 is indispensable for reproduction in ametabolous and hemimetabolous insects.

Ecdysone-induced protein 93 (E93), known as the 'adult-specifier' transcription factor in insects, triggers metamorphosis in both hemimetabolous and holometabolous insects. Although E93 is conserved in ametabolous insects, its spatiotemporal expression and physiological function remain poorly understood. In this study, we first discover that, in the ametabolous firebrat Thermobia domestica, the previtellogenic ovary exhibits cyclically high E93 expression, and E93 mRNA is broadly distributed in previtellogenic ovarioles. E93 homozygous mutant females of T. domestica exhibit severe fecundity deficiency due to impaired previtellogenic development of the ovarian follicles, likely because E93 induces the expression of genes involved in ECM (extracellular matrix)-receptor interactions during previtellogenesis. Moreover, we reveal that in the hemimetabolous cockroach Blattella germanica, E93 similarly promotes previtellogenic ovarian development. In addition, E93 is also essential for vitellogenesis that is necessary to guarantee ovarian maturation and promotes the vitellogenesis-previtellogenesis switch in the fat body of adult female cockroaches. Our findings deepen the understanding of the roles of E93 in controlling reproduction in insects, and of E93 expression and functional evolution, which are proposed to have made crucial contributions to the origin of insect metamorphosis.

WAV E3 ubiquitin ligases mediate degradation of IAA32/34 in the TMK1-mediated auxin signaling pathway during apical hook development.

Auxin regulates plant growth and development through downstream signaling pathways, including the best-known SCFTIR1/AFB-Aux/IAA-ARF pathway and several other less characterized "noncanonical" pathways. Recently, one SCFTIR1/AFB-independent noncanonical pathway, mediated by Transmembrane Kinase 1 (TMK1), was discovered through the analyses of its functions in Arabidopsis apical hook development. Asymmetric accumulation of auxin on the concave side of the apical hook triggers DAR1-catalyzed release of the C-terminal of TMK1, which migrates into the nucleus, where it phosphorylates and stabilizes IAA32/34 to inhibit cell elongation, which is essential for full apical hook formation. However, the molecular factors mediating IAA32/34 degradation have not been identified. Here, we show that proteins in the CYTOKININ INDUCED ROOT WAVING 1 (CKRW1)/WAVY GROWTH 3 (WAV3) subfamily act as E3 ubiquitin ligases to target IAA32/34 for ubiquitination and degradation, which is inhibited by TMK1c-mediated phosphorylation. This antagonistic interaction between TMK1c and CKRW1/WAV3 subfamily E3 ubiquitin ligases regulates IAA32/34 levels to control differential cell elongation along opposite sides of the apical hook.

Targeting 5-Hydroxytryptamine Receptor 1A in the Portal Vein to Decrease Portal Hypertension.

BACKGROUND & AIMS: Portal hypertension (PH) is one of the most frequent complications of chronic liver disease. The peripheral 5-hydroxytryptamine (5-HT) level was increased in cirrhotic patients. We aimed to elucidate the function and mechanism of 5-HT receptor 1A (HTR1A) in the portal vein (PV) on PH. METHODS: PH models were induced by thioacetamide injection, bile duct ligation, or partial PV ligation. HTR1A expression was detected using real-time polymerase chain reaction, in situ hybridization, and immunofluorescence staining. In situ intraportal infusion was used to assess the effects of 5-HT, the HTR1A agonist 8-OH-DPAT, and the HTR1A antagonist WAY-100635 on portal pressure (PP). Htr1a-knockout (Htr1a-/-) rats and vascular smooth muscle cell (VSMC)-specific Htr1a-knockout (Htr1aΔVSMC) mice were used to confirm the regulatory role of HTR1A on PP. RESULTS: HTR1A expression was significantly increased in the hypertensive PV of PH model rats and cirrhotic patients. Additionally, 8-OH-DPAT increased, but WAY-100635 decreased, the PP in rats without affecting liver fibrosis and systemic hemodynamics. Furthermore, 5-HT or 8-OH-DPAT directly induced the contraction of isolated PVs. Genetic deletion of Htr1a in rats and VSMC-specific Htr1a knockout in mice prevented the development of PH. Moreover, 5-HT triggered adenosine 3',5'-cyclic monophosphate pathway-mediated PV smooth muscle cell contraction via HTR1A in the PV. We also confirmed alverine as an HTR1A antagonist and demonstrated its capacity to decrease PP in rats with thioacetamide-, bile duct ligation-, and partial PV ligation-induced PH. CONCLUSIONS: Our findings reveal that 5-HT promotes PH by inducing the contraction of the PV and identify HTR1A as a promising therapeutic target for attenuating PH. As an HTR1A antagonist, alverine is expected to become a candidate for clinical PH treatment.

GSK3ß: A ray of hope for the treatment of diabetic kidney disease.

Diabetic kidney disease (DKD), a major microvascular complication of diabetes, is characterized by its complex pathogenesis, high risk of chronic renal failure, and lack of effective diagnosis and treatment methods. GSK3ß (glycogen synthase kinase 3ß), a highly conserved threonine/serine kinase, was found to activate glycogen synthase. As a key molecule of the glucose metabolism pathway, GSK3ß participates in a variety of cellular activities and plays a pivotal role in multiple diseases. However, these effects are not only mediated by affecting glucose metabolism. This review elaborates on the role of GSK3ß in DKD and its damage mechanism in different intrinsic renal cells. GSK3ß is also a biomarker indicating the progression of DKD. Finally, the protective effects of GSK3ß inhibitors on DKD are also discussed.

Exosomes derived from BMSCs in osteogenic differentiation promote type H blood vessel angiogenesis through miR-150-5p mediated metabolic reprogramming of endothelial cells.

Osteogenesis is tightly coupled with angiogenesis spatiotemporally. Previous studies have demonstrated that type H blood vessel formed by endothelial cells with high expression of CD31 and Emcn (CD31hi Emcnhi ECs) play a crucial role in bone regeneration. The mechanism of the molecular communication around CD31hi Emcnhi ECs and bone mesenchymal stem cells (BMSCs) in the osteogenic microenvironment is unclear. This study indicates that exosomes from bone mesenchymal stem cells with 7 days osteogenic differentiation (7D-BMSCs-exo) may promote CD31hi Emcnhi ECs angiogenesis, which was verified by tube formation assay, qRT-PCR, Western blot, immunofluorescence staining and µCT assays etc. in vitro and in vivo. Furthermore, by exosomal miRNA microarray and WGCNA assays, we identified downregulated miR-150-5p as the most relative hub gene coupling osteogenic differentiation and type H blood vessel angiogenesis. With bioinformatics assays, dual luciferase reporter experiments, qRT-PCR and Western blot assays, SOX2(SRY-Box Transcription Factor 2) was confirmed as a novel downstream target gene of miR-150-5p in exosomes, which might be a pivotal mechanism regulating CD31hi Emcnhi ECs formation. Additionally, JC-1 immunofluorescence staining, Western blot and seahorse assay results showed that the overexpression of SOX2 could shift metabolic reprogramming from oxidative phosphorylation (OXPHOS) to glycolysis to enhance the CD31hi Emcnhi ECs formation. The PI3k/Akt signaling pathway might play a key role in this process. In summary, BMSCs in osteogenic differentiation might secrete exosomes with low miR-150-5p expression to induce type H blood vessel formation by mediating SOX2 overexpression in ECs. These findings might reveal a molecular mechanism of osteogenesis coupled with type H blood vessel angiogenesis in the osteogenic microenvironment and provide a new therapeutic target or cell-free remedy for osteogenesis impaired diseases.

Precursor Engineering Induced High-Efficiency Electroluminescence of Quasi-Two-Dimensional Perovskites: A Synergistic Defect Inhibition and Passivation Approach.

Despite light-emitting diodes (LEDs) based on quasi-two-dimensional (Q-2D) perovskites being inexpensive and exhibiting high performance, defects still limit the improvement of electroluminescence efficiency and stability by causing nonradiative recombination. Here, an organic molecule, 1-(o-tolyl) biguanide, is used to simultaneously inhibit and passivate defects of Q-2D perovskites via in situ synchronous crystallization. This molecule not only prevents surface bromine vacancies from forming through hydrogen bonding with the bromine of intermediaries but also passivates surface defects through its interaction with uncoordinated Pb. Via combination of defect inhibition and passivation, the trap density of Q-2D perovskite films can be significantly reduced, and the emission efficiency of the film can be improved. Consequently, the corresponding LED shows an external quantum efficiency of 24.3%, and its operational stability has been increased nearly 15 times.

Solvent-Reconstructed Interface That Enhances Light Out-Coupling in Quasi-Two-Dimensional Perovskite Light-Emitting Diodes.

Light management is critical to maximizing the external quantum efficiency of perovskite light-emitting diodes (PeLEDs), but strategies for enhancing light out-coupling are typically complex and expensive. Here, using a facile solvent treatment strategy, we create a layer of lithium fluoride (LiF) nanoislands that serve as a template to reconstruct the light-extracting interfaces for PeLEDs. The nanoisland interface rearranges the near-field light distribution in order to maximize the efficiency of internal light extraction. With the proper adjustment of the nanoisland size and distribution, we have achieved an optimal balance between charge injection and light out-coupling, resulting in bright, pure-red quasi-two-dimensional PeLEDs with a 21.8% peak external quantum efficiency.

A single-chain antibody construct with specificity of a natural IgM antibody reduces hepatic ischemia reperfusion injury in mice.

Natural immunoglobulin M (IgM) antibodies have been shown to recognize post-ischemic neoepitopes following reperfusion of tissues and to activate complement. Specifically, IgM antibodies and complement have been shown to drive hepatic ischemia reperfusion injury (IRI). Herein, we investigate the therapeutic effect of C2 scFv (single-chain antibody construct with specificity of a natural IgM antibody) on hepatic IRI in C57BL/6 mice. Compared with PBS-treated mice, C2 scFv-treated mice displayed almost no necrotic areas, significant reduction in serum ALT, AST and LDH levels, and significantly reduced in the number of TUNEL positive cells. Moreover, C2 scFv-treated mice exhibited a notable reduction in inflammatory cells after hepatic IRI than PBS-treated mice. The serum IL-6, IL-1ß, TNF-α and MPC-1 levels were also severely suppressed by C2 scFv. Interestingly, C2 scFv reconstituted hepatic inflammation and IRI in Rag1-/- mice. We found that C2 scFv promoted hepatic cell death and increased inflammatory cytokines and infiltration of inflammatory cells after hepatic IRI in Rag1-/- mice. In addition, IgM and complement 3d (C3d) were deposited in WT mice and in Rag1-/- mice reconstituted with C2 scFv, indicating that C2 scFv can affect IgM binding and complement activation and reconstitute hepatic IRI. C3d expression was significantly lower in C57BL/6 mice treated with C2 scFv compared to PBS, indicating that excessive exogenous C2 scFv inhibited complement activation. These data suggest that C2 scFv alleviates hepatic IRI by blocking complement activation, and treatment with C2 scFv may be a promising therapy for hepatic IRI.

RNA Condensate as a Versatile Platform for Improving Fluorogenic RNA Aptamer Properties and Cell Imaging.

Fluorogenic RNA aptamers are valuable tools for cell imaging, but they still suffer from shortcomings such as easy degradation, limited photostability, and low fluorescence enhancement. Molecular crowding conditions enable the stabilization of the structure, promotion of folding, and improvement of activity of functional RNA. Based on artificial RNA condensates, here we present a versatile platform to improve fluorogenic RNA aptamer properties and develop sensors for target analyte imaging in living cells. Using the CUG repeat as a general tag to drive phase separation, various fluorogenic aptamer-based RNA condensates (FLARE) were prepared. We show that the molecular crowding of FLARE can improve the enzymatic resistance, thermostability, photostability, and binding affinity of fluorogenic RNA aptamers. Moreover, the FLARE systems can be modularly engineered into sensors (FLARES), which demonstrate enhanced brightness and sensitivity compared to free sensors dispersed in homogeneous solution. This scalable design principle provides new insights into RNA aptamer property regulation and cellular imaging.

Impaired distal renal potassium handling in streptozotocin-induced diabetic mice.

Diabetes is closely associated with K+ disturbances during disease progression and treatment. However, it remains unclear whether K+ imbalance occurs in diabetes with normal kidney function. In this study, we examined the effects of dietary K+ intake on systemic K+ balance and renal K+ handling in streptozotocin (STZ)-induced diabetic mice. The control and STZ mice were fed low or high K+ diet for 7 days to investigate the role of dietary K+ intake in renal K+ excretion and K+ homeostasis and to explore the underlying mechanism by evaluating K+ secretion-related transport proteins in distal nephrons. K+-deficient diet caused excessive urinary K+ loss, decreased daily K+ balance, and led to severe hypokalemia in STZ mice compared with control mice. In contrast, STZ mice showed an increased daily K+ balance and elevated plasma K+ level under K+-loading conditions. Dysregulation of the NaCl cotransporter (NCC), epithelial Na+ channel (ENaC), and renal outer medullary K+ channel (ROMK) was observed in diabetic mice fed either low or high K+ diet. Moreover, amiloride treatment reduced urinary K+ excretion and corrected hypokalemia in K+-restricted STZ mice. On the other hand, inhibition of SGLT2 by dapagliflozin promoted urinary K+ excretion and normalized plasma K+ levels in K+-supplemented STZ mice, at least partly by increasing ENaC activity. We conclude that STZ mice exhibited abnormal K+ balance and impaired renal K+ handling under either low or high K+ diet, which could be primarily attributed to the dysfunction of ENaC-dependent renal K+ excretion pathway, despite the possible role of NCC.NEW & NOTEWORTHY Neither low dietary K+ intake nor high dietary K+ intake effectively modulates renal K+ excretion and K+ homeostasis in STZ mice, which is closely related to the abnormality of ENaC expression and activity. SGLT2 inhibitor increases urinary K+ excretion and reduces plasma K+ level in STZ mice under high dietary K+ intake, an effect that may be partly due to the upregulation of ENaC activity.

Biocompatible Folic-Acid-Strengthened Ag-Ir Quantum Dot Nanozyme for Cell and Plant Root Imaging of Cysteine/Stress and Multichannel Monitoring of Hg2+ and Dopamine.

To boost the enzyme-like activity, biological compatibility, and antiaggregation effect of noble-metal-based nanozymes, folic-acid-strengthened Ag-Ir quantum dots (FA@Ag-Ir QDs) were developed. Not only did FA@Ag-Ir QDs exhibit excellent synergistic-enhancement peroxidase-like activity, high stability, and low toxicity, but they could also promote the lateral root propagation of Arabidopsis thaliana. Especially, ultratrace cysteine or Hg2+ could exclusively strengthen or deteriorate the inherent fluorescence property with an obvious "turn-on" or "turn-off" effect, and dopamine could alter the peroxidase-like activity with a clear hypochromic effect from blue to colorless. Under optimized conditions, FA@Ag-Ir QDs were successfully applied for the turn-on fluorescence imaging of cysteine or the stress response in cells and plant roots, the turn-off fluorescence monitoring of toxic Hg2+, or the visual detection of dopamine in aqueous, beverage, serum, or medical samples with low detection limits and satisfactory recoveries. The selective recognition mechanisms for FA@Ag-Ir QDs toward cysteine, Hg2+, and dopamine were illustrated. This work will offer insights into constructing some efficient nanozyme sensors for multichannel environmental analyses, especially for the prediagnosis of cysteine-related diseases or stress responses in organisms.

Optimizing Energy Levels and Improving Film Compactness in PbS Quantum Dot Solar Cells by Silver Doping.

PbS quantum dot (QD) solar cells harvest near-infrared solar radiation. Their conventional hole transport layer has limited hole collection efficiency due to energy level mismatch and poor film quality. Here, how to resolve these two issues by using Ag-doped PbS QDs are demonstrated. On the one hand, Ag doping relieves the compressive stress during layer deposition and thus improves film compactness and homogeneity to suppress leakage currents. On the other hand, Ag doping increases hole concentration, which aligns energy levels and increases hole mobility to boost hole collection. Increased hole concentration also broadens the depletion region of the active layer, decreasing interface charge accumulation and promoting carrier extraction efficiency. A champion power conversion efficiency of 12.42% is achieved by optimizing the hole transport layer in PbS QD solar cells, compared to 9.38% for control devices. Doping can be combined with compressive strain relief to optimize carrier concentration and energy levels in QDs, and even introduce other novel phenomena such as improved film quality.

DDIT3 aggravates TMJOA cartilage degradation via Nrf2/HO-1/NLRP3-mediated autophagy.

OBJECTIVE: DNA damage-inducible transcript 3 (DDIT3), as a downstream transcription factor of endoplasmic reticulum stress, is reported to regulate chondrogenic differentiation under physiological and pathological state. However, the specific involvement of DDIT3 in the degradation of condylar cartilage of temporomandibular joint osteoarthritis (TMJOA) is unclarified. DESIGN: The expression patterns of DDIT3 in condylar cartilage from monosodium iodoacetate-induced TMJOA mice were examined to uncover the potential role of DDIT3 in TMJOA. The Ddit3 knockout (Ddit3-/-) mice and their wildtype littermates (Ddit3+/+) were used to clarify the effect of DDIT3 on cartilage degradation. Primary condylar chondrocytes and ATDC5 cells were applied to explore the mechanisms of DDIT3 on autophagy and extracellular matrix (ECM) degradation in chondrocytes. The autophagy inhibitor chloroquine (CQ) was used to determine the effect of DDIT3-inhibited autophagy in vivo. RESULTS: DDIT3 were highly expressed in condylar cartilage from TMJOA mice. Ddit3 knockout alleviated condylar cartilage degradation and subchondral bone loss, compared with their wildtype littermates. In vitro study demonstrated that DDIT3 exacerbated ECM degradation in chondrocytes induced by TNF-α through inhibiting autophagy. The intraperitoneal injection of CQ further confirmed that Ddit3 knockout alleviated cartilage degradation in TMJOA through activating autophagy in vivo. CONCLUSIONS: Our findings identified the crucial role of DDIT3-inhibited autophagy in condylar cartilage degradation during the development of TMJOA.

Bidirectional mode-locked erbium-doped fiber laser based on an all-fiber gold nanofilm saturable absorber.

We demonstrate a bidirectional mode-locked erbium-doped fiber laser by incorporating gold nanofilm as a saturable absorber (SA). The gold nanofilm SA has the advantages of high stability and high optical damage threshold. Besides, the SA exhibits a large modulation depth of 26% and a low saturation intensity of 1.22 MW/cm2 at 1.56 µm wavelength band, facilitating the mode-locking of bidirectional propagating solitons within a single laser cavity. Bidirectional mode-locked solitons are achieved, with the clockwise pulse centered at 1568.35 nm and the counter-clockwise one at 1568.6 nm, resulting in a slight repetition rate difference of 19 Hz. Moreover, numerical simulations are performed to reveal the counter-propagating dynamics of the two solitons, showing good agreement with the experimental results. The asymmetric cavity configuration gives rise to distinct buildup and evolution dynamics of the two counter-propagating pulses. These findings highlight the advantage of the gold nanofilm SA in constructing bidirectional mode-locked fiber lasers and provide insights for understanding the bidirectional pulse propagation dynamics.

Translocator Protein 18 kDa Tracer 18F-FDPA PET/CTA Imaging for the Evaluation of Inflammation in Vulnerable Plaques.

Inflammation induced by activated macrophages within vulnerable atherosclerotic plaques (VAPs) constitutes a significant risk factor for plaque rupture. Translocator protein (TSPO) is highly expressed in activated macrophages. This study investigated the effectiveness of TSPO radiotracers, 18F-FDPA, in detecting VAPs and quantifying plaque inflammation in rabbits. 18 New Zealand rabbits were divided into 3 groups: sham group A, VAP model group B, and evolocumab treatment group C. 18F-FDPA PET/CTA imaging was performed at 12, 16, and 24 weeks in all groups. Optical coherence tomography (OCT) was performed on the abdominal aorta at 24 weeks. The VAP was defined through OCT images, and ex vivo aorta PET imaging was also performed at 24 weeks. The SUVmax and SUVmean of 18F-FDPA were measured on the target organ, and the target-to-background ratio (TBRmax) was calculated as SUVmax/SUVblood pool. The arterial sections of the isolated abdominal aorta were analyzed by HE staining, CD68 and TSPO immunofluorescence staining, and TSPO Western blot. The results showed that at 24 weeks, the plaque TBRmax of 18F-FDPA in group B was significantly higher than in groups A and C. Immunofluorescence staining of CD68 and TSPO, as well as Western blot, confirmed the increased expression of macrophages and TSPO in the corresponding regions of group B. HE staining revealed an increased presence of the lipid core, multiple foam cells, and inflammatory cell infiltration in the area with high 18F-FDPA uptake. This indicates a correlation between 18F-FDPA uptake, inflammation severity, and VAPs. The TSPO-targeted tracer 18F-FDPA shows specific uptake in macrophage-rich regions of atherosclerotic plaques, making it a valuable tool for assessing inflammation in VAPs.

Impact of homocysteine on acute ischemic stroke severity: possible role of aminothiols redox status.

BACKGROUND: Acute ischemic stroke (AIS) is one of the most common cerebrovascular diseases which accompanied by a disruption of aminothiols homeostasis. To explore the relationship of aminothiols with neurologic impairment severity, we investigated four aminothiols, homocysteine (Hcy), cysteine (Cys), cysteinylglycine (CG) and glutathione (GSH) in plasma and its influence on ischemic stroke severity in AIS patients. METHODS: A total of 150 clinical samples from AIS patients were selected for our study. The concentrations of free reduced Hcy (Hcy), own oxidized Hcy (HHcy), free reduced Cys (Cys), own oxidized Cys (cysteine, Cyss), free reduced CG (CG) and free reduced GSH (GSH) were measured by our previously developed hollow fiber centrifugal ultrafiltration (HFCF-UF) method coupled with high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). The concentration ratio of Hcy to HHcy (Hcy/HHcy), Cys to Cyss (Cys/Cyss) were also calculated. The neurologic impairment severity of AIS was evaluated using National Institutes of Health Stroke Scale (NIHSS). The Spearman correlation coefficient and logistic regression analysis was used to estimate and perform the correlation between Hcy, HHcy, Cys, Cyss, CG, GSH, Hcy/HHcy, Cys/Cyss and total Hcy with NIHSS score. RESULTS: The reduced Hcy and Hcy/HHcy was both negatively correlated with NIHSS score in AIS patients with P = 0.008, r=-0.215 and P = 0.002, r=-0.249, respectively. There was no significant correlation of Cys, CG, GSH, HHcy, Cyss, Cys/Cyss and total Hcy with NIHSS score in AIS patients with P value > 0.05. CONCLUSIONS: The reduced Hcy and Hcy/HHcy, not total Hcy concentration should be used to evaluate neurologic impairment severity of AIS patient.

Copper-catalyzed syn-hydroformylation of alkynes with silanes and N,N-dimethylformamide dimethylacetal.

A copper-catalyzed syn-hydrocarbonization of internal alkynes with N,N-dimethylformamide dimethylacetal and silanes has been disclosed that offers an efficient and expedient access to (E)-α,ß-unsaturated aldehydes. This highly selective process, which can be performed at gram-scale, enjoys operational simplicity, as well as syngas-free conditions.

Discovery of FO-4-15, a novel 1,2,4-oxadiazole derivative, ameliorates cognitive impairments in 3×Tg mice by activating the mGluR1/CaMKIIα pathway.

Alzheimer's disease (AD) is the most prevalent neurodegenerative disorder characterized by cognitive impairments. Despite the limited efficacy of current treatments for AD, the 1,2,4-oxadiazole structure has garnered significant attention in medicinal chemistry due to its potential impact on mGluR1 and its association with AD therapy. In this study, a series of novel 1,2,4-oxadiazole derivatives were designed, synthesized, and evaluated for the neuroprotective effects in human neuroblastoma (SH-SY5Y) cells. Among all the derivatives tested, FO-4-15 (5f) existed the lowest cytotoxicity and the highest protective effect against H2O2. Based on these in vitro results, FO-4-15 was administered to 3×Tg mice and significantly improved the cognitive impairments of the AD mice. Pathological analysis showed that FO-4-15 significantly reduced Aß accumulation, Tau hyper-phosphorylation, and synaptic impairments in the 3×Tg mice. Dysfunction of the CaMKIIα/Fos signaling pathway in 3×Tg mice was found to be restored by FO-4-15 and the necessity of the CaMKIIα/Fos for FO-4-15 was subsequently confirmed by the use of a CaMKIIα inhibitor in vitro. Beyond that, mGluR1 was identified to be a potential target of FO-4-15, and the interaction of FO-4-15 and mGluR1 was displayed by Ca2+ flow increase, molecular docking, and interaction energy analysis. The target of FO-4-15 was further confirmed in vitro by JNJ16259685, a nonselective inhibitor of mGluR1. These findings suggest that FO-4-15 may hold promise as a potential treatment for Alzheimer's disease.

Uptake, translocation, and metabolism of organophosphate esters (OPEs) in plants and health perspective for human: A review.

Plant uptake, accumulation, and transformation of organophosphate esters (OPEs) play vital roles in their geochemical cycles and exposure risks. Here we reviewed the recent research advances in OPEs in plants. The mean OPE concentrations based on dry/wet/lipid weight varied in 4.80-3,620/0.287-26.8/12,000-315,000 ng g-1 in field plants, and generally showed positive correlations with those in plant habitats. OPEs with short-chain substituents and high hydrophilicity, particularly the commonly used chlorinated OPEs, showed dominance in most plant samples, whereas some tree barks, fruits, seeds, and roots demonstrated dominance of hydrophobic OPEs. Both hydrophilic and hydrophobic OPEs can enter plants via root and foliar uptake, and the former pathway is mainly passively mediated by various membrane proteins. After entry, different OPEs undergo diverse subcellular distributions and acropetal/basipetal/intergenerational translocations, depending on their physicochemical properties. Hydrophilic OPEs mainly exist in cell sap and show strong transferability, hydrophobic OPEs demonstrate dominant distributions in cell wall and limited migrations owing to the interception of Casparian strips and cell wall. Additionally, plant species, transpiration capacity, growth stages, commensal microorganisms, and habitats also affect OPE uptake and transfer in plants. OPE metabolites derived from various Phase I transformations and Phase II conjugations are increasingly identified in plants, and hydrolysis and hydroxylation are the most common metabolic processes. The metabolisms and products of OPEs are closely associated with their structures and degradation resistance and plant species. In contrast, plant-derived food consumption contributes considerably to the total dietary intakes of OPEs by human, particularly the cereals, and merits specifical attention. Based on the current research limitations, we proposed the research perspectives regarding OPEs in plants, with the emphases on their behavior and fate in field plants, interactions with plant-related microorganisms, multiple uptake pathways and mechanisms, and comprehensive screening analysis and risk evaluation.

Cathepsin B degrades RbcL during freezing-induced programmed cell death in Arabidopsis.

KEY MESSAGE: Cathepsin B plays an important role that degrades the Rubisco large subunit RbcL in freezing stress. Programmed cell death (PCD) has been well documented in both development and in response to environmental stresses in plants, however, PCD induced by freezing stress and its molecular mechanisms remain poorly understood. In the present study, we characterized freezing-induced PCD and explored its mechanisms in Arabidopsis. PCD induced by freezing stress was similar to that induced by other stresses and senescence in Arabidopsis plants with cold acclimation. Inhibitor treatment assays and immunoblotting indicated that cathepsin B mainly contributed to increased caspase-3-like activity during freezing-induced PCD. Cathepsin B was involved in freezing-induced PCD and degraded the large subunit, RbcL, of Rubisco. Our results demonstrate an essential regulatory mechanism of cathepsin B for Rubisco degradation in freezing-induced PCD, improving our understanding of freezing-induced cell death and nitrogen and carbohydrate remobilisation in plants.