Genetic and lipidomic analyses reveal the key role of lipid metabolism for cold tolerance in maize

Lipid remodeling is crucial for cold tolerance in plants. However, the precise alternations of lipidomics during cold responses remain elusive, especially in maize (Zea mays L.). In addition, the key genes responsible for cold tolerance in maize lipid metabolism have not been identified. Here, we integrate lipidomic, transcriptomic, and genetic analysis to determine the profile of lipid remodeling caused by cold stress. We find that the homeostasis of cellular lipid metabolism is essential for maintaining cold tolerance of maize. Also, we detect 210 lipid species belonging to 13 major classes, covering phospholipids, glycerides, glycolipids, and free fatty acids. Various lipid metabolites undergo specific and selective alterations in response to cold stress, especially mono-/di-unsaturated lysophosphatidic acid, lysophosphatidylcholine, phosphatidylcholine, and phosphatidylinositol, as well as polyunsaturated phosphatidic acid, monogalactosyldiacylglycerol, diacylglycerol, and triacylglycerol. In addition, we identify a subset of key enzymes, including ketoacyl-acyl-carrier protein synthase II (KAS II), acyl-carrier protein 2 (ACP2), male sterility33 (Ms33), and stearoyl-acyl-carrier protein desaturase 2 (SAD2) involved in glycerolipid biosynthetic pathways are positive regulators of maize cold tolerance. These results reveal a comprehensive lipidomic profile during the cold response of maize and provide genetic resources for enhancing cold tolerance in crops.

Linking glucose signaling to nitrogen utilization by the OsHXK7-ARE4 complex in rice

How reciprocal regulation of carbon and nitrogen metabolism works is a long-standing question. In plants, glucose and nitrate are proposed to act as signaling molecules, regulating carbon and nitrogen metabolism via largely unknown mechanisms. Here, we show that the MYB-related transcription factor ARE4 coordinates glucose signaling and nitrogen utilization in rice. ARE4 is retained in the cytosol in complexing with the glucose sensor OsHXK7. Upon sensing a glucose signal, ARE4 is released, is translocated into the nucleus, and activates the expression of a subset of high-affinity nitrate transporter genes, thereby boosting nitrate uptake and accumulation. This regulatory scheme displays a diurnal pattern in response to circadian changes of soluble sugars. The are4 mutations compromise in nitrate utilization and plant growth, whereas overexpression of ARE4 increases grain size. We propose that the OsHXK7-ARE4 complex links glucose to the transcriptional regulation of nitrogen utilization, thereby coordinating carbon and nitrogen metabolism.

Nitric oxide-mediated S-nitrosylation of IAA17 protein in intrinsically disordered region represses auxin signaling

The phytohormone auxin plays crucial roles in nearly every aspect of plant growth and development. Auxin signaling is activated through the phytohormone-induced proteasomal degradation of the Auxin/INDOLE-3-ACETIC ACID (Aux/IAA) family of transcriptional repressors. Notably, many auxin-modulated physiological processes are also regulated by nitric oxide (NO) that executes its biological effects predominantly through protein S-nitrosylation at specific cysteine residues. However, little is known about the molecular mechanisms in regulating the interactive NO and auxin networks. Here, we show that NO represses auxin signaling by inhibiting IAA17 protein degradation. NO induces the S-nitrosylation of Cys-70 located in the intrinsically disordered region of IAA17, which inhibits the TIR1-IAA17 interaction and consequently the proteasomal degradation of IAA17. The accumulation of a higher level of IAA17 attenuates auxin response. Moreover, an IAA17C70W nitrosomimetic mutation renders the accumulation of a higher level of the mutated protein, thereby causing partial resistance to auxin and defective lateral root development. Taken together, these results suggest that S-nitrosylation of IAA17 at Cys-70 inhibits its interaction with TIR1, thereby negatively regulating auxin signaling. This study provides unique molecular insights into the redox-based auxin signaling in regulating plant growth and development.

[Research advances on the role and mechanism of microRNA in hypertrophic scar]

Hypertrophic scar (HS) affects the function and beauty of patients, and brings a heavy psychological burden to patients. However, the specific pathogenesis mechanism of HS in molecular biology level is not yet clear, and this disease is still one of the clinical diseases difficult to prevent and cure. MicroRNA (miR) is a family of single-stranded endogenous noncoding RNAs that can regulate gene expression. The abnormal transcription of miR in hypertrophic scar fibroblasts can affect the transduction and expression of downstream signal pathway or protein, and the exploration of miR and its downstream signal pathway and protein helps deeply understand the occurrence and development mechanism of scar hyperplasia. This article summarized and analyzed how miR and multiple signal pathways involve in the formation and development of HS in recent years, and further outlined the interaction between miR and target genes in HS.

Association of oxidative stress and Kashin-Beck disease integrated Meta and Bioinformatics analysis

OBJECTIVE

To explore the association between oxidative stress (OS) and Kashin-Beck disease (KBD).

METHODS

Terms associated with "KBD" and "OS" were searched in the six different databases up to October 2021. Stata 14.0 was used to pool the means and standard deviations using random-effect or fixed-effect model. The differentially expressed genes in the articular chondrocytes of KBD were identified, the OS related genes were identified by blasting with the GeneCards. The KEGG pathway and gene ontology enrichment analysis was conducted using STRING.

RESULTS

The pooled SMD and 95% CI showed hair selenium (-4.59; -6.99, -2.19), blood selenium (-1.65; -2.86, -0.44) and glutathione peroxidases (-4.15; -6.97, -1.33) levels were decreased in KBD, whereas the malondialdehyde (1.12; 0.60, 1.64), nitric oxide (2.29; 1.31, 3.27), nitric oxide synthase (1.07; 0.81, 1.33) and inducible nitric oxide synthase (1.69; 0.62, 2.77) were increased compared with external controls. Meanwhile, hair selenium (-2.71; -5.32, -0.10) and glutathione peroxidases (-1.00; -1.78, -0.22) in KBD were decreased, whereas the malondialdehyde (1.42; 1.04, 1.80), nitric oxide (3.08; 1.93, 4.22) and inducible nitric oxide synthase (0.81; 0.00, 1.61) were elevated compared with internal controls. Enrichment analysis revealed apoptosis was significantly correlated with KBD. The significant biological processes revealed OS induced the release of cytochrome c from mitochondria. The cellular component of OS located in the mitochondrial outer membrane.

CONCLUSIONS

The OS levels in KBD were significantly increased because of selenium deficiency, OS mainly occurred in mitochondrial outer membrane, released of cytochrome c from mitochondria, and induced apoptotic signaling pathway.

The cytosolic thiol peroxidase PRXIIB is an intracellular sensor for H2O2 that regulates plant immunity through a redox relay

Rapid production of H₂O₂ is a hallmark of plant responses to diverse pathogens and plays a crucial role in signalling downstream of various receptors that perceive immunogenic patterns. However, mechanisms by which plants sense H₂O₂ to regulate immunity remain poorly understood. We show that endogenous H₂O₂ generated upon immune activation is sensed by the thiol peroxidase PRXIIB via oxidation at Cys51, and this is essential for stomatal immunity against Pseudomonas syringae. We further show that in immune-stimulated cells, PRXIIB conjugates via Cys51 with the type 2C protein phosphatase ABA insensitive 2 (ABI2), subsequently transducing H₂O₂ signal to ABI2. This oxidation dramatically sensitizes H₂O₂-mediated inhibition of the ABI2 phosphatase activity in vitro and is required for stomatal immunity in plants. Together, our results illustrate a redox relay, with PRXIIB as a sensor for H₂O₂ and ABI2 as a target protein, that mediates reactive oxygen species signalling during plant immunity.

The SARS-CoV-2 rS1-E-PLGA nanovaccine and evaluation of its immune effect in BALB/c mice

OBJECTIVE

Vaccination is an important method for preventing COVID-19 infection. However, certain vaccines do not meet the current needs. To improve the vaccine effect, discard ineffective antigens, and focus on high-quality antigenic clusters, S1-E bivalent antigens were designed.

MATERIALS AND METHODS

Vaccine delivery is performed using poly (lactic-co-glycolic acid) (PLGA). Here, the recombinant S1-E (rS1-E) was covered on PLGA and injected intramuscularly into mice. In total, 48 BALB/c mice were randomly divided into six groups with 8 mice in each group. The mice received intramuscular injections. Prior to vaccination, the hydrophobicity of the rS1-E and the antigenic site of the E protein were both analysed. The morphology, zeta potential, and particle size distribution of rS1-E-PLGA were examined. Anti-S1 and anti-E antibodies were detected in mouse serum by ELISA. Neutralising an-tibodies were detected by co-incubating the pseudovirus with the obtained serum. IL-2 and TNF-α levels were also measured.

RESULTS

The designed recombinant S1-E protein was successfully coated on PLGA nanoparticles. rS1-E-PLGA nanovaccine has suitable size, shape, good stability, sustained release and other characteristics. Importantly, mice were stimulated with rS1-E-PLGA nanovaccines to produce high-titre antibodies and a good cellular immune response.

CONCLUSIONS

Our results indicate that rS1-E-PLGA nanovaccine may provide a good protective effect, and the vaccine should be further investigated in human clinical trials for use in vaccination or as a booster.

Two plant NLR proteins confer strain-specific resistance conditioned by an effector from Pseudomonas syringae pv. actinidiae

Pseudomonas syringae pv. actinidiae (Psa) causes bacterial canker, a devastating disease threatening the Actinidia fruit industry. In a search for non-host resistance genes against Psa, we found that the nucleotide-binding leucine-rich repeat receptor (NLR) protein ZAR1 from both Arabidopsis and Nicotiana benthamiana (Nb) recognizes HopZ5 and triggers cell death. The recognition requires ZED1 in Arabidopsis and JIM2 in Nb plants, which are members of the ZRK pseudokinases and known components of the ZAR1 resistosome. Surprisingly, Arabidopsis ZAR1 and RPM1, another NLR known to recognize HopZ5, confer disease resistance to HopZ5 in a strain-specific manner. Thus, ZAR1, but not RPM1, is solely required for resistance to P. s. maculicola ES4326 (Psm) carrying hopZ5, whereas RPM1 is primarily required for resistance to P. s. tomato DC3000 (Pst) carrying hopZ5. Furthermore, the ZAR1-mediated resistance to Psm hopZ5 in Arabidopsis is insensitive to SOBER1, which encodes a deacetylase known to suppress the RPM1-mediated resistance to Pst hopZ5. In addition, hopZ5 enhances P. syringae virulence in the absence of ZAR1 or RPM1, and that SOBER1 abolishes such virulence function. Together the study suggests that ZAR1 may be used for improving Psa resistance in Actinidia and uncovers previously unknown complexity of effector-triggered immunity and effector-triggered virulence.

Nitric oxide negatively regulates gibberellin signaling to coordinate growth and salt tolerance in Arabidopsis

In response to dynamically altered environments, plants must finely coordinate the balance between growth and stress responses for their survival. However, the underpinning regulatory mechanisms remain largely elusive. The phytohormone gibberellin promotes growth via a derepression mechanism by proteasomal degradation of the DELLA transcription repressors. Conversely, the stress-induced burst of nitric oxide (NO) enhances stress tolerance, largely relaying on NO-mediated S-nitrosylation, a redox-based posttranslational modification. Here, we show that S-nitrosylation of Cys-374 in the Arabidopsis RGA protein, a key member of DELLAs, inhibits its interaction with the F-box protein SLY1, thereby preventing its proteasomal degradation under salinity condition. The accumulation of RGA consequently retards growth but enhances salt tolerance. We propose that NO negatively regulates gibberellin signaling via S-nitrosylation of RGA to coordinate the balance of growth and stress responses when challenged by adverse environments.

The Burden of Colorectal Cancer Attributable to Diet Low in Fiber from 1990 to 2019: A Global, Regional and National Analysis

OBJECTIVES

The colorectal cancer (CRC) burden is increasingly high. The aim of this study was to investigate temporal and geographical trends in CRC deaths and disability-adjusted life-years (DALYs) attributable to diet low in fiber globally from 1990 to 2019.

DESIGN

Cross-sectional study.

SETTING

The study based on the Global Burden of Disease Study (GBD) 2019.

PARTICIPANTS

The population comprised individuals from 204 countries and territories who were diagnosed with CRC attributable to diet low in fiber from 1990 to 2019.

MEASUREMENTS

Deaths, DALYs, age-standardized mortality rates (ASMR), and age-standardized DALY rates (ASDR) for CRC attributable to diet low in fiber were described, and estimated annual percentage change (EAPC) was further calculated to assess the burden in different regions, countries, sexes, and age groups. Additionally, we explored the association between EAPC and ASMR/ASDR (in 1990) and Human Development Index (HDI, in 2019).

RESULTS

From 1990 to 2019, global ASMR and ASDR for CRC attributable to diet low in fiber decreased slightly, but the corresponding deaths and DALYs increased by 63.37% and 51.36%, respectively. Those burden varied considerably between regions and countries. The burden was higher in high, high-middle and middle SDI regions, especially in Asia and Western Europe, but when HDI > 0.7, an increasingly rapid decline in ASMR and ASDR was revealed. Unexpectedly, many less well-developed countries within the traditionally low deaths and DALYs regions of Africa, Central Latin America, and Middle East showed gradual increases in ASMR and ASDR.

CONCLUSION

The global burden of CRC attributable to diet low in fiber has decreased over the last 30 years, but remains at a high level. It is essential for decision-makers to take targeted measures for improving population awareness and intake of dietary fiber.

[Identification of serum peptide biomarker for ovarian cancer diagnosis by Clin-TOF-II-MS combined with magnetic beads technology]

Objective: To explore the serum cyclic polypeptide biomarkers for ovarian cancer diagnosis. Methods: A total of 54 patients with epithelial ovarian cancer confirmed by pathology in Cancer Hospital, Chinese Academy of Medical Sciences from March 2018 to September 2018 were selected as the study subjects, and 40 healthy women with normal examination results in the cancer screening center were selected as the control. All of the samples were randomly divided into training set and validation set at the ratio of 1∶1 with a random number. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) combined with magnetic bead technology was used for detecting peptide profiling in serum samples to screen significantly differently expressed peptides between ovarian cancer group and control group of the training set (score>5). Receiver operating characteristic (ROC) curve analysis was used to screen differential peptide peaks with area under curve (AUC) ≥0.8, sensitivity and specificity>90% in the training set and validation set. Liquid chromatography-mass spectrometry (LC-MS/MS) was further used to determine the composition of differentially expressed peptides. Results: By comparing the peptide profiles of the two groups, 102 differential peptide peaks were initially detected in the mass-to-charge ratio range of 1 000 to 10 000. ROC curve analysis showed that there were 42 differential peptide peaks with AUC ≥0.8 in both training set and validation set, 19 of which were highly expressed in ovarian cancer group, and 23 were lowly expressed. There were 15 different peptide peaks in highly expressed ovarian cancer group with sensitivity and specificity over 90%. The mass-to-charge ratios were 7 744.27, 5 913.41, 5 329.87, 4 634.21, 4 202.02, 3 879.26, 3 273.35, 3 253.79, 3 234.34, 2 950.33, 2 664.51, 2 018.38, 1 893.37, 1 498.69 and 1 287.55. There were 15 different peptide peaks in lowly expressed ovarian cancer group with sensitivity and specificity over 90%, the mass-to-charge ratios were 9 288.46, 7 759.77, 5 925.24, 4 652.77, 4 210.42, 3 887.02, 3 279.90, 3 240.82, 2 962.15, 2 932.70, 2 022.42, 1 897.16, 1 501.69, 1 337.38 and 1 290.13. No protein composition was identified in 15 different peptide peaks in lowly expressed ovarian cancer group. The two protein compositions identified in 15 different peptide peaks in highly expressed ovarian cancer group were recombinant serglycin (SRGN) and fibinogen alpha chain (FGA), the mass-to-charge ratios of which were 1 498.696 and 5 913.417, respectively. The sensitivity and specificity of the two proteins for ovarian cancer diagnosis were 100%, 100% and 90.9%, 100%, respectively. Conclusion: SRGN and FGA are highly expressed in the serum of ovarian cancer patients, which may be potential diagnostic markers for ovarian cancer.

Antibody responses after first and second Covid-19 vaccination in patients with chronic lymphocytic leukaemia

B-cell chronic lymphocytic leukaemia (CLL) is associated with immunosuppression and patients are at increased clinical risk following SARS-CoV-2 infection. Covid-19 vaccines offer the potential for protection against severe infection but relatively little is known regarding the profile of the antibody response following first or second vaccination. We studied spike-specific antibody responses following first and/or second Covid-19 vaccination in 299 patients with CLL compared with healthy donors. 286 patients underwent extended interval (10-12 week) vaccination. 154 patients received the BNT162b2 mRNA vaccine and 145 patients received ChAdOx1. Blood samples were taken either by venepuncture or as dried blood spots on filter paper. Spike-specific antibody responses were detectable in 34% of patients with CLL after one vaccine (n = 267) compared to 94% in healthy donors with antibody titres 104-fold lower in the patient group. Antibody responses increased to 75% after second vaccine (n = 55), compared to 100% in healthy donors, although titres remained lower. Multivariate analysis showed that current treatment with BTK inhibitors or IgA deficiency were independently associated with failure to generate an antibody response after the second vaccine. This work supports the need for optimisation of vaccination strategy in patients with CLL including the potential utility of booster vaccines.

[Analysis of PARP inhibitors induced anemia in advanced and relapsed epithelial ovarian cancer]

Objective: To explore the clinical features of poly ADP-ribose polymerase (PARP) inhibitor-related anemia in advanced and relapsed epithelial ovarian cancer (EOC). Methods: Patients diagnosed with advanced or relapsed EOC and treated with PARP inhibitor at National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College between January 2015 to October 2020 were accrued. The data included PARP inhibitors, treatment details, and lab tests before treatment and during treatment were collected and the clinical characteristics of PARP inhibitor-related anemia were analyzed. Results: (1) A total of 98 patients with a median age of 56.5 years old (30-82 years old) were enrolled in this study. All patients were treated with PARP inhibitor (65 cases of olaparib, 17 cases of niraparib, and 16 cases of fluzoparib). The median treatment duration was 37.5 weeks (4-119 weeks). (2) The anemia rate was 40% (39/98), including 5% (5/98) of grade Ⅰ, 14% (14/98) of grade Ⅱ, 11% (11/98) of grade Ⅲ, and 9% (9/98) of grade Ⅳ. Fourteen patients with pre-treatment grade Ⅰ anemia had a higher rate of anemia events than the 80 patients without pre-treatment anemia, 7/14 vs 35% (28/80; χ²=4.281, P=0.039). (3) The median anemia occurrence time was 7.0 weeks (1-52 weeks), including 41% (16/39) of anemia cases occurred in 1-4 weeks, 26% (10/39) occurred in 5-8 weeks, 13% (5/39) occurred in 9-12 weeks, 3% (1/39) occurred in 13-16 weeks, 10% (4/39) occurred in 17-20 weeks, 8% (3/39) occurred ≥21 weeks. At the time of the lowest hemoglobulin tested, the median value of mean corpuscular volume (MCV) was 106 fl,which was higher than the up limit of normal range (100 fl), 74% (29/39) of anemia patients had an elevated MCV level; the median value of mean corpuscular hemoglobin (MCH) was 36 pg, 54% (21/39) of anemia patients had an elevated MCH level; the median value of mean corpuscular hemoglobin concentration (MCHC) was 320 g/L, 69% (27/39) of anemia patients had a higher MCHC level; 92% (36/39) of anemia patients had a normal level of serum iron; 79% (31/39) of anemia patients had a normal level of transferrin. 74% (29/39) of the anemia patients were macrocytic orthochromatic anemia. (4) Among the 39 patients with anemia, 20 patients (51%, 20/39) withhold the treatment of PARP inhibitor due to grade Ⅲ or Ⅳ anemia, including 10 patients (50%, 10/20) who resumed the PARP inhibitor treatment by suppling iron, folate, and vitamin B₁₂. The median stopping time of PARP inhibitor was 5.5 weeks (2-10 weeks), while the other 10 patients terminated the PARP inhibitor treatment for not recovering from severe anemia. Conclusions: One of the common adverse effects of PARP inhibitors is anemia, which mostly happened in the first 3 months of treatment. In the treatment of EOC, PARP inhibitor-related anemia mainly manifest as macrocytic orthochromatic anemia, and most patients with normal serum iron and transferrin.

The Ghd7 transcription factor represses ARE1 expression to enhance nitrogen utilization and grain yield in rice

The genetic improvement of nitrogen use efficiency (NUE) of crops is vital for grain productivity and sustainable agriculture. However, the regulatory mechanism of NUE remains largely elusive. Here, we report that the rice Grain number, plant height, and heading date7 (Ghd7) gene genetically acts upstream of ABC1 REPRESSOR1 (ARE1), a negative regulator of NUE, to positively regulate nitrogen utilization. As a transcriptional repressor, Ghd7 directly binds to two Evening Element-like motifs in the promoter and intron 1 of ARE1, likely in a cooperative manner, to repress its expression. Ghd7 and ARE1 display diurnal expression patterns in an inverse oscillation manner, mirroring a regulatory scheme based on these two loci. Analysis of a panel of 2656 rice varieties suggests that the elite alleles of Ghd7 and ARE1 have undergone diversifying selection during breeding. Moreover, the allelic distribution of Ghd7 and ARE1 is associated with the soil nitrogen deposition rate in East Asia and South Asia. Remarkably, the combination of the Ghd7 and ARE1 elite alleles substantially improves NUE and yield performance under nitrogen-limiting conditions. Collectively, these results define a Ghd7-ARE1-based regulatory mechanism of nitrogen utilization, providing useful targets for genetic improvement of rice NUE.

A route to de novo domestication of wild allotetraploid rice

Cultivated rice varieties are all diploid, and polyploidization of rice has long been desired because of its advantages in genome buffering, vigorousness, and environmental robustness. However, a workable route remains elusive. Here, we describe a practical strategy, namely de novo domestication of wild allotetraploid rice. By screening allotetraploid wild rice inventory, we identified one genotype of Oryza alta (CCDD), polyploid rice 1 (PPR1), and established two important resources for its de novo domestication: (1) an efficient tissue culture, transformation, and genome editing system and (2) a high-quality genome assembly discriminated into two subgenomes of 12 chromosomes apiece. With these resources, we show that six agronomically important traits could be rapidly improved by editing O. alta homologs of the genes controlling these traits in diploid rice. Our results demonstrate the possibility that de novo domesticated allotetraploid rice can be developed into a new staple cereal to strengthen world food security.

An Arabidopsis Secondary Metabolite Directly Targets Expression of the Bacterial Type III Secretion System to Inhibit Bacterial Virulence

Plants deploy a variety of secondary metabolites to fend off pathogen attack. Although defense compounds are generally considered toxic to microbes, the exact mechanisms are often unknown. Here, we show that the Arabidopsis defense compound sulforaphane (SFN) functions primarily by inhibiting Pseudomonas syringae type III secretion system (TTSS) genes, which are essential for pathogenesis. Plants lacking the aliphatic glucosinolate pathway, which do not accumulate SFN, were unable to attenuate TTSS gene expression and exhibited increased susceptibility to P. syringae strains that cannot detoxify SFN. Chemoproteomics analyses showed that SFN covalently modified the cysteine at position 209 of HrpS, a key transcription factor controlling TTSS gene expression. Site-directed mutagenesis and functional analyses further confirmed that Cys209 was responsible for bacterial sensitivity to SFN in vitro and sensitivity to plant defenses conferred by the aliphatic glucosinolate pathway. Collectively, these results illustrate a previously unknown mechanism by which plants disarm a pathogenic bacterium.

Maintenance treatment in advanced HER2-negative gastric cancer

Survival for patients with advanced gastric cancer (GC) remains poor. Systemic chemotherapy which has reached a plateau stays the standard first-line (1L) treatment for advanced human epidermal growth-factor receptor 2 (HER2)-negative GC. To maximize the benefit of 1L treatment, the concept of maintenance treatment is constantly being explored. In advanced HER2-negative GC, current clinical guidelines do not recommend a standard maintenance therapy strategy. In addition to the monotherapy maintenance with fluorouracil after 4-6 cycles of 1L chemotherapy, some agents that are active against novel targets have been evaluated in clinical trials for maintenance treatment. Whereas most of these trials do not reach their primary endpoints, they open new horizons for the 1L treatment of advanced HER2-negative GC. Therefore, we reviewed the clinical trials in the field of maintenance treatment in advanced HER2-negative GC and discussed some of the problems in clinical trials.

The split-off terahertz radiating dipoles on thermally reduced α-V2O5 (001) surface

The trapped electron states on a pliable lattice have different localization and physical chemistry characteristics. Here, terahertz time-domain measurements suggest that the formation of vanadyl oxygen defect, in the presence of the surface potential traps and mobile charge carriers, leads to a transient charge distribution that forms terahertz radiating dipoles in V2O5. The emergence of radiating dipoles is evidenced by terahertz responses with a two-valley feature of the thermally reduced α-V2O5 (001) thin films in the temperature range of 300-700 K. The two photoconductance valleys on a several millielectron volts interval are related to two emergent split-off traps, which originate from the VO6 octahedra distortion upon the vanadyl oxygen desorption on the surface. The pliable surface lattices plays a decisive role. So long as the α-V2O5 (001) thin films are covered by a 30 nm-thick Al2O3 capping layer, the distinct two-valley feature disappears completely in the full temperature range. The terahertz radiating dipoles with a fine energy structure is potentially a new measure for charge dynamics on the α-V2O5 (001) surface.

Intravitreal conbercept for branch retinal vein occlusion induced macular edema: one initial injection versus three monthly injections

Background

To compare the efficacy of one initial intravitreal injection of conbercept (IVC) versus three monthly IVCs in patients with macular edema (ME) after branch retinal vein occlusion (BRVO). Both options were followed by a pro re nata (PRN) retreatment regimen.

Methods

This study retrospectively investigated and followed 60 patients with acute ME secondary to BRVO for over a year. 30 subjects received one initial injection (1 + PRN group); while, 30 received three monthly injections (3 + PRN group). The functional and anatomic outcomes were assessed during each follow-up.

Results

The general characteristics of the 60 subjects were as follows: mean [SD] age, 57.43 [13.06] years; 33 [55%] female; 36 [60%] non-ischemic form. Both groups showed a stable gain in visual acuity (VA) with similar logMAR (mean ± SD) (1 + PRN group 0.308 ± 0.399, 3 + PRN group 0.34 ± 0.352) during the first 12 months. Additionally, both groups exhibited a significant reduction in central foveal thickness (CFT) with no statistically significant difference between them (1 + PRN group 222.1 μm ± 197.1 μm, 3 + PRN group 228.4 μm ± 200.2 μm). Both treatment groups had similar improvements in logMAR and anatomic outcomes over time. The stratified analysis showed that patients with the non-ischemic form and those with the ischemic form had similar improvements in VA (0.346 ± 0.366 VS 0.29 ± 0.39, P = 0.575) during the 12 months follow-ups. The number of injections was lower in the 1 + PRN group (4.0 ± 1.6) than in the 3 + PRN group (4.7 ± 1.3) (P = 0.068). No adverse effects or unexpected safety issues were reported in either group.

Conclusions

Conbercept yielded significant improvements in VA and CFT among patients with BRVO induced ME, independent of their retinal ischemia status. The results showed that the 3 + PRN regimen do not lead to better functional outcomes or lower treatment needs in clinical practice as compared to the 1 + PRN regimen.

Transnitrosylation Mediated by the Non-canonical Catalase ROG1 Regulates Nitric Oxide Signaling in Plants

The redox-based protein S-nitrosylation is a conserved mechanism modulating nitric oxide (NO) signaling and has been considered mainly as a non-enzymatic reaction. S-nitrosylation is regulated by the intracellular NO level that is tightly controlled by S-nitrosoglutathione reductase (GSNOR). However, the molecular mechanisms regulating S-nitrosylation selectivity remain elusive. Here, we characterize an Arabidopsis "repressor of" gsnor1 (rog1) mutation that specifically suppresses the gsnor1 mutant phenotype. ROG1, identical to the non-canonical catalase, CAT3, is a transnitrosylase that specifically modifies GSNOR1 at Cys-10. The transnitrosylase activity of ROG1 is regulated by a unique and highly conserved Cys-343 residue. A ROG1^C343T mutant displays increased catalase but decreased transnitrosylase activities. Consistent with these results, the rog1 mutation compromises responses to NO under both normal and stress conditions. We propose that ROG1 functions as a transnitrosylase to regulate the NO-based redox signaling in plants.

Two Plastid Fatty Acid Exporters Contribute to Seed Oil Accumulation in Arabidopsis

Triacylglycerols (TAGs) are the major storage form of seed oil in oilseed plants. They are biosynthesized de novo in seed plastids and then transported into the endoplasmic reticulum. However, the transport mechanism for plastid fatty acids in developing seeds remains unknown. Here, we isolated two novel plastid fatty acid exporters (FATTYACID EXPORT 2 [FAX2] and FAX4, respectively) specifically abundant in seed embryos during the seed-filling stage in Arabidopsis (Arabidopsis thaliana). FAX2 and FAX4 were both localized to the chloroplast membrane. FAX2 and FAX4 loss-of-function mutations caused deficiencies in embryo and cotyledon development. Seeds of fax2fax4 double mutants exhibited significantly reduced TAG contents but elevated levels of plastid lipid contents compared with those of wild-type plants. By contrast, overexpression of FAX2 or FAX4 enhanced TAG deposition. Seed-feeding experiments showed that the two FAX proteins transported ¹⁴C-plastid fatty acids and ¹³C-oleic acids for TAG biosynthesis during the seed-filling stage. Together, our data demonstrate that FAX2 and FAX4 play critical roles in transporting plastid fatty acids for TAG biosynthesis during seed embryo development. These two transporters may have broad application for increasing oil yield in oilseed crops.

Protein S-Nitrosylation in plants: Current progresses and challenges

Nitric oxide (NO) is an important signaling molecule regulating diverse biological processes in all living organisms. A major physiological function of NO is executed via protein S-nitrosylation, a redox-based posttranslational modification by covalently adding a NO molecule to a reactive cysteine thiol of a target protein. S-nitrosylation is an evolutionarily conserved mechanism modulating multiple aspects of cellular signaling. During the past decade, significant progress has been made in functional characterization of S-nitrosylated proteins in plants. Emerging evidence indicates that protein S-nitrosylation is ubiquitously involved in the regulation of plant development and stress responses. Here we review current understanding on the regulatory mechanisms of protein S-nitrosylation in various biological processes in plants and highlight key challenges in this field.

A new insight to explore the regulation between S-nitrosylation and N-glycosylation

Nitric oxide (NO) is a signal molecule in plants and animals. Arabidopsis GSNO reductase1 (AtGSNOR1) catalyzes metabolism of S-nitrosoglutathione (GSNO) which is a major biologically active NO species. The GSNOR1 loss-of-function mutant gsnor1-3 overaccumulates GSNO with inherent high S-nitrosylation level and resistance to the oxidative stress inducer paraquat (1,1'-dimethyl-4,4'-bipyridinium dichloride). Here, we report the characterization of dgl1-3 as a genetic suppressor of gsnor1-3. DGL1 encodes a subunit of the oligosaccharyltransferse (OST) complex which catalyzes the formation of N-glycosidic bonds in N-glycosylation. The fact that dgl1-3 repressed the paraquat resistance of gsnor1-3 meanwhile gsnor1-3 rescued the embryo-lethal and post-embryonic development defect of dgl1-3 reminded us the possibility that S-nitrosylation and N-glycosylation crosstalk with each other through co-substrates. By enriching glycoproteins in gsnor1-3 and mass spectrometry analysis, TGG2 (thioglucoside glucohydrolase2) was identified as one of co-substrates with high degradation rate and elevated N-glycosylation level in gsnor1-3 ost3/6. The S-nitrosylation and N-glycosylation profiles were also modified in dgl1-3 and gsnor1-3. Thereby, we propose a linkage between S-nitrosylation and N-glycosylation through co-substrates.

Risk factors of postoperative complications after emergency repair of incarcerated groin hernia for adult patients: a retrospective cohort study

Purpose

This study aimed to explore risk factors of postoperative complications for adult patients with incarcerated groin hernia (IGH).

Methods

From January 2010 to December 2017, consecutive patients undergoing emergency hernia repair for IGH in our center were retrospectively reviewed. Postoperative complications, such as surgical site infection, seroma, hernia recurrence and mortality, were investigated, with risk factors for such complications analyzed using univariate and multivariate regressions.

Results

Sixty-four patients were included, with 51 males and 13 females (mean age 65.1, range 25–98 years). Ten patients (15.6%) underwent resection of necrotic bowel and anastomosis. 43 patients (67.2%) received open tension-free herniorrhaphy with polypropylene mesh, whereas the rest (32.8%) received herniorrhaphy without mesh. The overall postoperative complication rate was 40.6% (26/64), with an incisional complication rate of 31.2% (20/64) and an infection rate of 6.2% (4/64). At a median follow-up of 32 months, hernia recurrence and mortality were recorded in five cases each (7.8%). Mesh repair was associated with decreased recurrence rate compared with non-mesh repair (2.3% vs. 19.0%, p = 0.019). Diabetes mellitus (OR 8.611, 95%CI 1.292–57.405; p = 0.026) was an independent risk factor of postoperative complications, together with chronic obstructive pulmonary disease (COPD; OR 14.365, 95%CI 1.652–127.767, p = 0.016), intestinal necrosis (OR 14.260, 95%CI 1.079–188.460, p = 0.044), and general anesthesia (OR 14.543, 95%CI 1.682–125.711, p = 0.015) as risk for incisional complications after surgery.

Conclusions

Diabetes mellitus was an independent risk factor of postoperative complications for IGH, along with COPD, intestinal necrosis and general anesthesia associated with incisional complications. The use of polypropylene mesh did not increase infection or recurrence rate in this cohort.

Exosomes: novel regulators of bone remodelling and potential therapeutic agents for orthodontics

Recent studies suggest that exosomes are involved in intercellular communication required for the maintenance of healthy bone. Exosomes are small (30-150 nm in diameter) extracellular vesicles that are formed in multivesicular bodies and are released from cells as the multivesicular bodies fuse with the plasma membrane. Regulatory exosomes have the capacity to exert profound control over target cells. They can stimulate plasma membrane receptors and are also internalized by the target cell delivering proteins, lipids, small molecules and functional RNAs from the cell of origin. We and others have recently reported on regulatory exosomes from osteoclasts and osteoblasts. Key candidate molecules identified in exosome-based regulation of bone remodelling include receptor activator of nuclear factor kappa B (RANK), RANK-ligand (RANKL), ephrinA2, semaphorin 4D, microRNA-146a and microRNA- 214-3p. Exosomes will likely prove to be crucial elements in the communication networks integrating bone cells (osteoclasts, osteoblasts, osteocytes) and linking bone to other tissue. Exosomes collected from bone cells grown in culture may prove useful to augment bone remodelling associated with orthodontic force application or required for the repair of craniofacial bone. Various technologies allow exosomes to be engineered to improve their targeting and efficacy for therapeutic purposes. In summary, exosomes have emerged as important elements of the machinery for intercellular communication between bone cells. They hold great promise as therapeutic targets, biomarkers and therapeutic agents for orthodontists.

S-Nitrosylation Targets GSNO Reductase for Selective Autophagy during Hypoxia Responses in Plants

Nitric oxide (NO) regulates diverse cellular signaling through S-nitrosylation of specific Cys residues of target proteins. The intracellular level of S-nitrosoglutathione (GSNO), a major bioactive NO species, is regulated by GSNO reductase (GSNOR), a highly conserved master regulator of NO signaling. However, little is known about how the activity of GSNOR is regulated. Here, we show that S-nitrosylation induces selective autophagy of Arabidopsis GSNOR1 during hypoxia responses. S-nitrosylation of GSNOR1 at Cys-10 induces conformational changes, exposing its AUTOPHAGY-RELATED8 (ATG8)-interacting motif (AIM) accessible by autophagy machinery. Upon binding by ATG8, GSNOR1 is recruited into the autophagosome and degraded in an AIM-dependent manner. Physiologically, the S-nitrosylation-induced selective autophagy of GSNOR1 is relevant to hypoxia responses. Our discovery reveals a unique mechanism by which S-nitrosylation mediates selective autophagy of GSNOR1, thereby establishing a molecular link between NO signaling and autophagy.

Malate transported from chloroplast to mitochondrion triggers production of ROS and PCD in Arabidopsis thaliana

Programmed cell death (PCD) is a fundamental biological process. Deficiency in MOSAIC DEATH 1 (MOD1), a plastid-localized enoyl-ACP reductase, leads to the accumulation of reactive oxygen species (ROS) and PCD, which can be suppressed by mitochondrial complex I mutations, indicating a signal from chloroplasts to mitochondria. However, this signal remains to be elucidated. In this study, through cloning and analyzing a series of mod1 suppressors, we reveal a comprehensive organelle communication pathway that regulates the generation of mitochondrial ROS and triggers PCD. We show that mutations in PLASTIDIAL NAD-DEPENDENT MALATE DEHYDROGENASE (plNAD-MDH), chloroplastic DICARBOXYLATE TRANSPORTER 1 (DiT1) and MITOCHONDRIAL MALATE DEHYDROGENASE 1 (mMDH1) can each rescue the ROS accumulation and PCD phenotypes in mod1, demonstrating a direct communication from chloroplasts to mitochondria via the malate shuttle. Further studies demonstrate that these elements play critical roles in the redox homeostasis and plant growth under different photoperiod conditions. Moreover, we reveal that the ROS level and PCD are significantly increased in malate-treated HeLa cells, which can be dramatically attenuated by knockdown of the human gene MDH2, an ortholog of Arabidopsis mMDH1. These results uncover a conserved malate-induced PCD pathway in plant and animal systems, revolutionizing our understanding of the communication between organelles.

Genetic variations in ARE1 mediate grain yield by modulating nitrogen utilization in rice

In crops, nitrogen directly determines productivity and biomass. However, the improvement of nitrogen utilization efficiency (NUE) is still a major challenge in modern agriculture. Here, we report the characterization of are1, a genetic suppressor of a rice fd-gogat mutant defective in nitrogen assimilation. ARE1 is a highly conserved gene, encoding a chloroplast-localized protein. Loss-of-function mutations in ARE1 cause delayed senescence and result in 10-20% grain yield increases, hence enhance NUE under nitrogen-limiting conditions. Analysis of a panel of 2155 rice varieties reveals that 18% indica and 48% aus accessions carry small insertions in the ARE1 promoter, which result in a reduction in ARE1 expression and an increase in grain yield under nitrogen-limiting conditions. We propose that ARE1 is a key mediator of NUE and represents a promising target for breeding high-yield cultivars under nitrogen-limiting condition.

Adjuvant radiotherapy for positive lymph nodes of oesophageal squamous cell carcinoma: Can it earn promising benefits at long-term follow-up?

PURPOSE

The value of adjuvant radiotherapy for patients with positive lymph nodes after curative resection of oesophageal squamous cell carcinoma is controversial. This study aims to investigate its long-term benefits in a specific cohort.

PATIENTS AND METHODS

The charts between 1990 and 2003 from patients with positive lymph nodes were retrospectively reviewed. Those subjects were divided into adjuvant radiotherapy and surgery alone groups, with two subgroups defined by radiation dose (cutoff value: 50Gy). Overall survival, disease-free survival and locoregional recurrence-free survival were compared between two groups, with predictive factors of overall survival analysed meanwhile.

RESULTS

In sum, 175 matched patients with 1:2 ratios for group balance were enrolled for final analysis. During the follow-up (median: 37.0 months), 143 (81.7%) deaths were recorded, with 70.6% of deaths from cancer progression. The median overall survival time (19.5, 4 to 172 months) was not significantly different between the two groups (18.9 vs. 20.0 months, P=0.179). However, the disease-free survival time was significantly shorter in the adjuvant radiotherapy group than that in the control group (median, 11.5 vs. 14.9 months; P=0.001), with the locoregional recurrence-free survival time impressively prolonged (median: 18.3 vs. 16.5 months; P=0.022). Age (P=0.030), number (P=0.005) and ratio (P=0.002) of positive lymph nodes were associated with overall survival, but radiation dose was not (P=0.204).

CONCLUSION

Adjuvant radiotherapy with low- or high-dose did not improve survival compared with surgery alone. However, radiotherapy was effective to control locoregional recurrence, and could be applied as salvage therapy when recurrence event occurred.

[Expressions and clinical significances of paired box gene 2 and cyclin D1 in advanced ovarian serous carcinoma]

Objective: To investigate the expressions and clinical significances of paired box gene 2 (Pax2) and cyclin D1 protein in advanced ovarian serous carcinoma. Methods: From January 2003 to December 2013, the pathologic tissues of 202 patients with advanced ovarian serous cancer (Ⅲ-Ⅳ) who underwent initial cytoreductive surgery were collected. The expressions of Pax2 and cyclin D1 protein were detected by immunohistochemistry in tissue microarray. The relationships of their expressions with the clinicopathological features and prognosis of the patients were analyzed. Results: The positive rate of Pax2 protein expression of the 202 patients with ovarian serous adenocarcinoma was 24.8% (50/202) and that of cyclin D1 was 25.2% (51/202). The expressions of Pax2 and cyclin D1 were not significantly related with age, clinical stage and pathological grade of ovarian serous adenocarcinoma patients (P>0.05). The median overall survival (OS) time of Pax2-negative patients was 53 months and the progression-free survival (PFS) time was 29 months. The median OS time of Pax2-positive patients was 66 months and PFS time was 33 months, the OS of Pax2-negative patients was significant different from that of Pax2-positive patients (χ(2)=4.06, P=0.04). The median PFS time of Pax2-negative patients was not significant different from that of Pax2-positive patients (χ(2)=2.43, P=0.11). The median OS time of cyclin D1-negative patients was 62 months and PFS time was 30 months. The median OS time of cyclin D1-positive patients was 48 months and PFS time was 22 months. The median OS time of cyclin D1-negative patients was significantly different from that of cyclin D1-positive patients (χ(2)=4.71, P=0.03), while the median PFS time of cyclin D1-negative patients was marginally different from that of cyclin D1-positive patients (χ(2)=0.59, P=0.41). Multivariate analysis showed that the expression of Pax2 was an independent factor of the prognosis for patients with ovarian serous adenocarcinoma (RR=0.597, 95% CI 0.371-0.962, P<0.034). Conclusion: The expressions of Pax2 and cyclin D1 are associated with the prognosis of patients with advanced ovarian serous adenocarcinoma while Pax2 is an independent prognostic factor.

Nitric Oxide Regulates Protein Methylation during Stress Responses in Plants

Methylation and nitric oxide (NO)-based S-nitrosylation are highly conserved protein posttranslational modifications that regulate diverse biological processes. In higher eukaryotes, PRMT5 catalyzes Arg symmetric dimethylation, including key components of the spliceosome. The Arabidopsis prmt5 mutant shows severe developmental defects and impaired stress responses. However, little is known about the mechanisms regulating the PRMT5 activity. Here, we report that NO positively regulates the PRMT5 activity through S-nitrosylation at Cys-125 during stress responses. In prmt5-1 plants, a PRMT5^C125S transgene, carrying a non-nitrosylatable mutation at Cys-125, fully rescues the developmental defects, but not the stress hypersensitive phenotype and the responsiveness to NO during stress responses. Moreover, the salt-induced Arg symmetric dimethylation is abolished in PRMT5^C125S/prmt5-1 plants, correlated to aberrant splicing of pre-mRNA derived from a stress-related gene. These findings define a mechanism by which plants transduce stress-triggered NO signal to protein methylation machinery through S-nitrosylation of PRMT5 in response to environmental alterations.

Rice Ferredoxin-Dependent Glutamate Synthase Regulates Nitrogen-Carbon Metabolomes and Is Genetically Differentiated between japonica and indica Subspecies

Plants assimilate inorganic nitrogen absorbed from soil into organic forms as Gln and Glu through the glutamine synthetase/glutamine:2-oxoglutarate amidotransferase (GS/GOGAT) cycle. Whereas GS catalyzes the formation of Gln from Glu and ammonia, GOGAT catalyzes the transfer of an amide group from Gln to 2-oxoglutarate to produce two molecules of Glu. However, the regulatory role of the GS/GOGAT cycle in the carbon-nitrogen balance is not well understood. Here, we report the functional characterization of rice ABNORMAL CYTOKININ RESPONSE 1 (ABC1) gene that encodes a ferredoxin-dependent (Fd)-GOGAT. The weak mutant allele abc1-1 mutant shows a typical nitrogen-deficient syndrome, whereas the T-DNA insertional mutant abc1-2 is seedling lethal. Metabolomics analysis revealed the accumulation of an excessive amount of amino acids with high N/C ratio (Gln and Asn) and several intermediates in the tricarboxylic acid cycle in abc1-1, suggesting that ABC1 plays a critical role in nitrogen assimilation and carbon-nitrogen balance. Five non-synonymous single-nucleotide polymorphisms were identified in the ABC1 coding region and characterized as three distinct haplotypes, which have been highly and specifically differentiated between japonica and indica subspecies. Collectively, these results suggest that ABC1/OsFd-GOGAT is essential for plant growth and development by modulating nitrogen assimilation and the carbon-nitrogen balance.

The Arabidopsis CROWDED NUCLEI genes regulate seed germination by modulating degradation of ABI5 protein

In Arabidopsis, the phytohormone abscisic acid (ABA) plays a vital role in inhibiting seed germination and in post-germination seedling establishment. In the ABA signaling pathway, ABI5, a basic Leu zipper transcription factor, has important functions in the regulation of seed germination. ABI5 protein localizes in nuclear bodies, along with AFP, COP1, and SIZ1, and was degraded through the 26S proteasome pathway. However, the mechanisms of ABI5 nuclear body formation and ABI5 protein degradation remain obscure. In this study, we found that the Arabidopsis CROWDED NUCLEI (CRWN) proteins, predicted nuclear matrix proteins essential for maintenance of nuclear morphology, also participate in ABA-controlled seed germination by regulating the degradation of ABI5 protein. During seed germination, the crwn mutants are hypersensitive to ABA and have higher levels of ABI5 protein compared to wild type. Genetic analysis suggested that CRWNs act upstream of ABI5. The observation that CRWN3 colocalizes with ABI5 in nuclear bodies indicates that CRWNs might participate in ABI5 protein degradation in nuclear bodies. Moreover, we revealed that the extreme C-terminal of CRWN3 protein is necessary for its function in the response to ABA in germination. Our results suggested important roles of CRWNs in ABI5 nuclear body organization and ABI5 protein degradation during seed germination.

Oncogenic Ras differentially regulates metabolism and anoikis in extracellular matrix-detached cells

In order for cancer cells to survive during metastasis, they must overcome anoikis, a caspase-dependent cell death process triggered by extracellular matrix (ECM) detachment, and rectify detachment-induced metabolic defects that compromise cell survival. However, the precise signals used by cancer cells to facilitate their survival during metastasis remain poorly understood. We have discovered that oncogenic Ras facilitates the survival of ECM-detached cancer cells by using distinct effector pathways to regulate metabolism and block anoikis. Surprisingly, we find that while Ras-mediated phosphatidylinositol (3)-kinase signaling is critical for rectifying ECM-detachment-induced metabolic deficiencies, the critical downstream effector is serum and glucocorticoid-regulated kinase-1 (SGK-1) rather than Akt. Our data also indicate that oncogenic Ras blocks anoikis by diminishing expression of the phosphatase PHLPP1 (PH Domain and Leucine-Rich Repeat Protein Phosphatase 1), which promotes anoikis through the activation of p38 MAPK. Thus, our study represents a novel paradigm whereby oncogene-initiated signal transduction can promote the survival of ECM-detached cells through divergent downstream effectors.

Characterization of Regulatory Extracellular Vesicles from Osteoclasts

Extracellular vesicles (EVs), which include exosomes and ectosomes/microvesicles, have emerged as important intercellular regulators. EVs can interact with surface receptors of target cells and can transport luminal components, including messenger RNAs (mRNAs), microRNAs, and enzymes, to the cytosol of the target cell. Here, we show that hematopoietic cells grown in culture shed exosome-like EVs as they differentiate from preosteoclasts into osteoclasts. These EVs were between 25 and 120 nm (mean, 40 nm) in diameter determined by transmission electron microscopy. The exosome-associated markers CD63 and EpCAM were enriched in the isolated EVs while markers of Golgi and endoplasmic reticulum were not detected. Treatment of isolated hematopoietic cells with EVs did not affect their receptor activator of nuclear factor κB-ligand (RANKL)-stimulated differentiation into osteoclasts. However, EVs from osteoclast precursors promoted 1,25-dihydroxyvitamin D3-dependent osteoclast formation in whole mouse marrow cultures, and EVs from osteoclast-enriched cultures inhibited osteoclastogenesis in the same cultures. These data suggested that osteoclast-derived EVs are paracrine regulators of osteoclastogenesis. EVs from mature osteoclasts contained receptor activator of nuclear factor κB (RANK). Immunogold labeling showed RANK was enriched in 1 in every 32 EVs isolated from osteoclast-enriched cultures. Depletion of RANK-rich EVs relieved the ability of osteoclast-derived EVs to inhibit osteoclast formation in 1,25-dihydroxyvitamin D3-stimulated marrow cultures. In summary, we show for the first time that EVs released by osteoclasts are novel regulators of osteoclastogenesis. Our data suggest that RANK in EVs may be mechanistically linked to the inhibition of osteoclast formation. RANK present in EVs may function by competitively inhibiting the stimulation of RANK on osteoclast surfaces by RANKL similar to osteoprotegerin. RANK-rich EVs may also take advantage of the RANK/RANKL interaction to target RANK-rich EVs to RANKL-bearing cells for the delivery of other regulatory molecules.

TonEBP modulates the protective effect of taurine in ischemia-induced cytotoxicity in cardiomyocytes

Taurine, which is found at high concentration in the heart, exerts several protective actions on myocardium. Physically, the high level of taurine in heart is maintained by a taurine transporter (TauT), the expression of which is suppressed under ischemic insult. Although taurine supplementation upregulates TauT expression, elevates the intracellular taurine content and ameliorates the ischemic injury of cardiomyocytes (CMs), little is known about the regulatory mechanisms of taurine governing TauT expression under ischemia. In this study, we describe the TonE (tonicity-responsive element)/TonEBP (TonE-binding protein) pathway involved in the taurine-regulated TauT expression in ischemic CMs. Taurine inhibited the ubiquitin-dependent proteasomal degradation of TonEBP, promoted the translocation of TonEBP into the nucleus, enhanced TauT promoter activity and finally upregulated TauT expression in CMs. In addition, we observed that TonEBP had an anti-apoptotic and anti-oxidative role in CMs under ischemia. Moreover, the protective effects of taurine on myocardial ischemia were TonEBP dependent. Collectively, our findings suggest that TonEBP is a core molecule in the protective mechanism of taurine in CMs under ischemic insult.

Rice TUTOU1 Encodes a Suppressor of cAMP Receptor-Like Protein That Is Important for Actin Organization and Panicle Development

Panicle development, a key event in rice (Oryza sativa) reproduction and a critical determinant of grain yield, forms a branched structure containing multiple spikelets. Genetic and environmental factors can perturb panicle development, causing panicles to degenerate and producing characteristic whitish, small spikelets with severely reduced fertility and yield; however, little is known about the molecular basis of the formation of degenerating panicles in rice. Here, we report the identification and characterization of the rice panicle degenerative mutant tutou1 (tut1), which shows severe defects in panicle development. The tut1 also shows a pleiotropic phenotype, characterized by short roots, reduced plant height, and abnormal development of anthers and pollen grains. Molecular genetic studies revealed that TUT1 encodes a suppressor of cAMP receptor/Wiskott-Aldrich syndrome protein family verprolin-homologous (SCAR/WAVE)-like protein. We found that TUT1 contains conserved functional domains found in eukaryotic SCAR/WAVE proteins, and was able to activate Actin-related protein2/3 to promote actin nucleation and polymerization in vitro. Consistently, tut1 mutants show defects in the arrangement of actin filaments in trichome. These results indicate that TUT1 is a functional SCAR/WAVE protein and plays an important role in panicle development.