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1.
Comput Biol Med ; 171: 107987, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38350395

ABSTRACT

OBJECTIVE: Alignment between preoperative images (high-resolution magnetic resonance imaging, magnetic resonance angiography) and intraoperative medical images (digital subtraction angiography) is currently required in neurointerventional surgery. Treating a lesion is usually guided by a 2D DSA silhouette image. DSA silhouette images increase procedure time and radiation exposure time due to the lack of anatomical information, but information from MRA images can be utilized to compensate for this in order to improve procedure efficiency. In this paper, we abstract this into the problem of relative pose and correspondence between a 3D point and its 2D projection. Multimodal images have a large amount of noise and anomalies that are difficult to resolve using conventional methods. According to our research, there are fewer multimodal fusion methods to perform the full procedure. APPROACH: Therefore, the paper introduces a registration pipeline for multimodal images with fused dual views is presented. Deep learning methods are introduced to accomplish feature extraction of multimodal images to automate the process. Besides, the paper proposes a registration method based on the Factor of Maximum Bounds (FMB). The key insights are to relax the constraints on the lower bound, enhance the constraints on the upper bounds, and mine more local consensus information in the point set using a second perspective to generate accurate pose estimation. MAIN RESULTS: Compared to existing 2D/3D point set registration methods, this method utilizes a different problem formulation, searches the rotation and translation space more efficiently, and improves registration speed. SIGNIFICANCE: Experiments with synthesized and real data show that the proposed method was achieved in accuracy, robustness, and time efficiency.


Subject(s)
Magnetic Resonance Angiography , Magnetic Resonance Imaging , Magnetic Resonance Angiography/methods , Magnetic Resonance Imaging/methods , Angiography, Digital Subtraction/methods , Imaging, Three-Dimensional/methods , Algorithms
2.
Ophthalmol Retina ; 2023 Nov 30.
Article in English | MEDLINE | ID: mdl-38040056

ABSTRACT

PURPOSE: To describe the clinical features and outcomes of vitreoretinal lymphoma (VRL) with intraretinal infiltration, a pseudonecrotic variant. DESIGN: Retrospective, comparative analysis. SUBJECTS: Patients with biopsy-proven VRL at a single center from August 2016 to April 2022. METHODS: A retrospective record review was conducted for clinical, imaging, and laboratory data. MAIN OUTCOME MEASURES: Clinical features, visual, and survival outcomes. RESULTS: We included 67 eyes of 40 patients with biopsy-proven VRL. Pseudonecrotic retinal lesions (PRLs) were found in 24 (35.8%) eyes of 19 patients; these eyes were classified as a pseudonecrotic variant, whereas the remaining 43 (64.2%) eyes were classified as nonnecrotic. Comparison (pseudonecrotic vs. nonnecrotic) revealed that eyes with PRLs at presentation had a worse median best-corrected visual acuity (BCVA; 2.4 vs. 0.5 logarithm of the minimum angle of resolution [logMAR], P < 0.0001) and severe ocular manifestations (P < 0.0001), including optic disc swelling (79.2% vs. 0%), retinal vasculitis (93.8% vs. 4.7%), retinal hemorrhage (83.3% vs. 0%), and retinal detachment (RD) (79.2% vs. 0%). Follow-up data were available for 20 eyes (17 patients) in the pseudonecrotic group and 43 eyes (21 patients) in the nonnecrotic group. An equally worse median BCVA was noted in pseudonecrotic eyes at 6 months after treatment and the final follow-up as compared with nonnecrotic eyes (2.4 vs. 0.3 logMAR, P < 0.0001). The median follow-up period did not differ significantly (16.6 vs. 18.4 months, P = 0.47). Initial BCVA (ß = 0.300, P = 0.003), presence of anterior chamber cell (ß = 0.472, P = 0.013), and RD (ß = 1.137, P < 0.0001) were significantly associated with poor visual outcomes in multivariate linear regression analysis (adjusted R2 = 0.693). There were no significant differences in survival outcomes. CONCLUSION: Vitreoretinal lymphoma can present as pseudonecrotic retinopathy, with more advanced clinical presentations and worse final visual outcomes. FINANCIAL DISCLOSURE(S): The author(s) have no proprietary or commercial interest in any materials discussed in this article.

3.
Ocul Immunol Inflamm ; : 1-8, 2023 Feb 09.
Article in English | MEDLINE | ID: mdl-36758245

ABSTRACT

PURPOSE: To develop diagnostic recommendations for diffuse large B-cell vitreoretinal lymphoma (VRL) in Chinese patients. METHODS: Retrospective observational case series. Seventy-three eyes of 40 VRL patients and 8 control patients were analyzed. Eighteen patients from Beijing Tongren Hospital and 46 patients from literature were involved as validations. RESULTS: Diagnostic methods included (1) typical clinical manifestations; (2) vitreous cytology; (3) immunohistochemical examination of vitreous or choroid/retina; (4) aqueous humor or vitreous cytokine; (5) vitreous cell gene rearrangement; (6) vitreous flow cytometry. If patients meet (1)+(2)+(3), or if they meet (1), and two of (4), (5), (6) are positive, they can be diagnosed as VRL. The sensitivity and specificity values for accurate diagnosis were 0.975 and 1.00. One hundred percent eyes from Beijing Tongren Hospital and 92.7% eyes from literature can be diagnosed. CONCLUSION: We developed diagnostic recommendations for diffuse large B-cell VRL through vitreous cytology combined with multiple auxiliary examinations.

4.
Clin Exp Ophthalmol ; 51(2): 144-153, 2023 03.
Article in English | MEDLINE | ID: mdl-36567492

ABSTRACT

BACKGROUND: Although early detection is critical, diagnosing vitreoretinal lymphoma (VRL) remains difficult. We sought to assess the potential diagnostic value of spectral-domain optical coherence tomography (SD-OCT) in VRL. METHODS: We reviewed the clinical records and pre-treatment SD-OCT images of biopsy-confirmed VRL and uveitis patients, with primary involvement of the sub-retinal pigment epithelium (RPE) and the outer retina, including acute syphilitic posterior placoid chorioretinitis (ASPPC), chronic stage sympathetic ophthalmitis (SO), and idiopathic multifocal choroiditis (MFC). RESULTS: We included 45 eyes of 45 VRL patients and 40 eyes of 40 uveitis patients (17 ASPPC eyes, eight chronic SO eyes, and 15 MFC eyes). On SD-OCT, lymphoma cell infiltration was observed in various retinal layers, most commonly in the sub-RPE (80%) and sub-retinal space (62%). Highly sensitive features for VRL as compared to uveitis included vitreous cells (93%), focal hyper-reflective sub-retinal infiltration (51%), and diffuse RPE elevations (56%). The features strongly specific for VRL included preretinal deposits (92.5%), intra-retinal infiltration (except the incomplete vertical hyper-reflective type, 100%), banded hyper-reflective sub-retinal infiltration (90%), and confluent RPE detachments (100%). We identified an approach to VRL diagnosis based on these SD-OCT findings: (1) two highly sensitive features plus one strongly specific feature; or (2) one highly sensitive feature plus two strongly specific features, demonstrated a sensitivity of 80% and specificity of 95% for VRL. CONCLUSIONS: The SD-OCT may enable the detection of detailed lymphoma infiltration characteristics and provide significant supplemental value for VRL diagnosis, particularly when combining highly sensitive and specific VRL-associated SD-OCT features.


Subject(s)
Chorioretinitis , Eye Neoplasms , Lymphoma , Retinal Neoplasms , Syphilis , Humans , Tomography, Optical Coherence/methods , Retinal Neoplasms/drug therapy , Vitreous Body/diagnostic imaging , Vitreous Body/pathology , Retina/pathology , Chorioretinitis/drug therapy , Eye Neoplasms/pathology , Lymphoma/diagnosis , Retrospective Studies , Fluorescein Angiography
5.
Ocul Immunol Inflamm ; : 1-6, 2022 Dec 12.
Article in English | MEDLINE | ID: mdl-36508690

ABSTRACT

PURPOSE: To investigate the morphological features of keratic precipitates (KPs) with in vivo confocal microscopy (IVCM) in vitreoretinal lymphoma (VRL). METHODS: Patients with biopsy-proven VRL were reviewed, and 12 patients (16 eyes) with KPs examined by IVCM were included. RESULTS: Five distinct KP morphologies on IVCM were observed: dendritic, nibbling, linear, globular, and stippled. Dendritic KPs were discovered in 9 eyes (56.3%), with a hyperreflective core and multiple thin pseudopodia. Nibbling KPs were found in 8 eyes (50.0%), featuring irregularly hyperreflective borders and a mottled reflective interior. Linear, stippled, and globular KPs were self-explanatory and affected nearly all eyes. Globular KPs seem to be formed by hyperreflective cells with large nuclei and prominent nucleoli, similar to atypical lymphocytes in vitreous cytology. CONCLUSIONS: IVCM could provide more insight into the morphological traits of KPs than clinical observation, highlighting its potential for identifying VRL involving the anterior segment.

6.
Exp Hematol Oncol ; 11(1): 95, 2022 Nov 08.
Article in English | MEDLINE | ID: mdl-36348442

ABSTRACT

Vitreoretinal lymphoma (VRL) is strongly linked to central nervous system (CNS) progression with no standard treatment approaches. Commonly used strategies include repeated intraocular injections of low-dose methotrexate or local radiotherapy, with great inconvenience, long-term side effects, and high risk of CNS relapse. In this study, we evaluated the efficacy and safety of bruton's tyrosine kinase inhibitors (BTKi) in the treatment of VRL. This prospective single-center study enrolled patients with relapsed or newly diagnosed VRL between October 2020 and April 2022. Patients received BTKi monotherapy until disease progression or unacceptable toxicity. The primary endpoint was the disease control (DC) rate after one month of treatment; secondary endpoints include toxicity, overall survival (OS), and progression-free survival (PFS). Ten consecutive patients with VRL were enrolled into this study. After 1-month treatment, 9 patients (90%) achieved a DC, with 7 patients (70%) achieving a complete response (CR). With a median follow-up of 8.3 (2.5-21.4) months, 4 patients were confirmed to have disease progression, with a PFS of 1.2, 7.5, 9.1, and 11.6 months, respectively. The remaining 6 patients have durable control of disease and were still on treatment at time of the analysis. BTKi were well-tolerated and no patients discontinued the drug because of adverse events. In conclusion, targeting BTK in VRL is viable, and our findings could pave the way for a paradigm change in VRL therapy choices. Further large-scale studies, however, are required to give stronger evidence about the efficacy and safety.

7.
Comput Biol Med ; 146: 105496, 2022 07.
Article in English | MEDLINE | ID: mdl-35594684

ABSTRACT

Digital Subtraction Angiography (DSA) has become an essential method in diagnosing and detecting vascular bleeding points. According to the frame number sequence, doctors subjectively analyze gray-black DSA data to diagnose vascular bleeding points. This study carried out parametric color imaging processing on the original two-dimensional DSA image sequence to assist doctors in judging blood vessel bleeding more accurately and quickly on angiography results and obtain quantitative standards. Five parameter values are calculated by enhancing the two-dimensional DSA image, segmenting the blood vessel area of the two-dimensional DSA image, and fitting the time-concentration curve. The parameters include AUC, time to peak, development time, transit time, and flow rate of contrast agent. The parameter value determines the gray value of the image pixel point and generates a color image with corresponding parameters through image pseudo-color processing. The color imaging results of each parameter of 33 groups of simulated hemorrhage data in-vitro and DSA data of 42 cases of vascular bleeding points determine the selection of parameters to assist in diagnosing vascular bleeding points, and the experimental results finally select the development time parameter color imaging result map to assist doctors in diagnosing blood vessel bleeding points.


Subject(s)
Contrast Media , Image Processing, Computer-Assisted , Angiography, Digital Subtraction/methods , Hemorrhage/diagnostic imaging , Humans , Image Processing, Computer-Assisted/methods
8.
BMC Ophthalmol ; 22(1): 104, 2022 Mar 05.
Article in English | MEDLINE | ID: mdl-35248002

ABSTRACT

BACKGROUND: To report a case of herpetic uveitis caused by herpes simplex virus after cataract surgery in a patient without prior viral keratitis or uveitis. CASE PRESENTATION: A 70-year-old female was referred to our clinic with a 16-day history of acute blurry vision with painful redness in the right eye. She accepted cataract surgery for the right eye ten days before initial of ocular symptoms. There was significant inflammation in anterior chamber of the right eye. Retina exam showed moderate dense vitreous opacity but not necrotic or focal retinal lesion in the right eye. The aqueous humor collected from the right eye was positive for herpes simplex virus (HSV) DNA by PCR. The diagnosis of herpetic uveitis in the right eye was made due to clinical presentations and aqueous humor examination. CONCLUSION: Herpetic virus reactivation might occasionally occur after intraocular surgery in patients without prior ocular viral diseases, inducing atypical postoperative intraocular inflammation.


Subject(s)
Cataract , Keratitis, Herpetic , Keratitis , Uveitis, Anterior , Uveitis , Aged , DNA, Viral/analysis , Female , Humans , Keratitis, Herpetic/diagnosis , Simplexvirus , Uveitis/diagnosis , Uveitis, Anterior/diagnosis , Uveitis, Anterior/etiology
9.
Retina ; 42(10): 2018-2023, 2022 10 01.
Article in English | MEDLINE | ID: mdl-34653114
10.
Int J Mol Sci ; 22(22)2021 Nov 09.
Article in English | MEDLINE | ID: mdl-34829996

ABSTRACT

Hydrogen sulfide (H2S) is an important signaling molecule that regulates diverse cellular signaling pathways through persulfidation. Our previous study revealed that H2S is involved in the improvement of rice drought tolerance. However, the corresponding enzymatic sources of H2S and its regulatory mechanism in response to drought stress are not clear. Here, we cloned and characterized a putative l-cysteine desulfhydrase (LCD) gene in rice, which encodes a protein possessing H2S-producing activity and was named OsLCD1. Overexpression of OsLCD1 results in enhanced H2S production, persulfidation of total soluble protein, and confers rice drought tolerance. Further, we found that nitrate reductase (NR) activity was decreased under drought stress, and the inhibition of NR activity was controlled by endogenous H2S production. Persulfidation of NIA2, an NR isoform responsible for the main NR activity, led to a decrease in total NR activity in rice. Furthermore, drought stress-triggered inhibition of NR activity and persulfidation of NIA2 was intensified in the OsLCD1 overexpression line. Phenotypical and molecular analysis revealed that mutation of NIA2 enhanced rice drought tolerance by activating the expression of genes encoding antioxidant enzymes and ABA-responsive genes. Taken together, our results showed the role of OsLCD1 in modulating H2S production and provided insight into H2S-regulated persulfidation of NIA2 in the control of rice drought stress.


Subject(s)
Cystathionine gamma-Lyase/genetics , Nitrate Reductase (NADH)/genetics , Oryza/metabolism , Stress, Physiological/genetics , Abscisic Acid/metabolism , Antioxidants/metabolism , Cystathionine gamma-Lyase/metabolism , Cysteine , Droughts , Hydrogen Sulfide/metabolism , Nitrate Reductase (NADH)/metabolism , Oryza/genetics , Oryza/growth & development , Seedlings/genetics , Seedlings/growth & development , Signal Transduction/genetics
11.
Front Oncol ; 11: 676792, 2021.
Article in English | MEDLINE | ID: mdl-33968786

ABSTRACT

Vitreoretinal lymphoma (VRL) is a rare intraocular malignancy, and standard treatment approaches have not been defined yet. Bruton tyrosine kinase inhibitors are found to be effective in the treatment of primary central nervous system diffuse large B cell lymphoma. Herein, we retrospectively reported the efficacy and safety profiles of bruton tyrosine kinase inhibitors in three consecutive patients with VRL. All three cases of VRL occurred in patients with pre-treated primary central nervous system lymphoma and the central nervous system was not involved at the time of VRL diagnosis. They were treated with zanubrutinib, a bruton tyrosine kinase inhibitor, at 160 mg twice daily orally. Rapid improvement of visual acuity and tumor control was achieved in all involved eyes of these 3 patients. Complete remission was confirmed by fundus photograph and optical coherence tomography, and the level of interleukin-10, a well-recognized biomarker for vitreoretinal lymphoma, decreased to normal in all patients. Zanubrutinib was well tolerated in all three patients, and only one adverse event of grade 3 hypertension occurred, which resolved after adjusting antihypertensive drugs. As of March 2021, these three patients have been treated with zanubrutinib for 9 months, 7 months, and 6 months, respectively, and all remained in complete remission. In conclusion, targeting bruton tyrosine kinase with zanubrutinib in vitreoretinal lymphoma is feasible and our findings can be a foundation for a paradigm shift in treatment options for this rare disease. A prospective phase 2 study evaluating the efficacy and safety of zanubrutinib in patients with vitreoretinal lymphoma is ongoing to validate our findings (ChiCTR2000037921).

12.
BMC Ophthalmol ; 21(1): 93, 2021 Feb 18.
Article in English | MEDLINE | ID: mdl-33602140

ABSTRACT

BACKGROUND: To report a case of genetically confirmed gyrate atrophy (GA) of choroid and retina, who showed partial regression of foveoschisis following vitamin B6 supplementary therapy. CASE PRESENTATION: A 6-year-old Chinese girl complained about night blindness and progressive decreased vision in both eyes. Her best corrected visual acuity (BCVA) was 20/63 OD and 20/100 OS. Fundus examination showed bilateral multiple, sharply demarcated, scallop-shaped chorioretinal atrophy areas in the midperipheral and peripheral of the fundus. Spectral domain optical coherence tomography (SD-OCT) showed increased central macular thickness (CMT) with multiple intraretinal cystic spaces in the both eyes. There was no leakage or staining in the macular area in late phase of fluorescein angiography (FA). Blood tests confirmed hyperornithinemia and genetic analysis revealed two heterozygous mutations on ornithine aminotransferase (OAT) gene. Based on clinical presentation and genetic test, the patient was diagnosed as GA of the choroid and retina and further treated with vitamin B6 supplementary for three weeks. Her serum ornithine levels did not change but CMT on SD-OCT declined with partial regression of intraretinal cystic spaces. Then, the patient discontinued the drug because of severe muscle pain, and foveoschisis increased to initial level a month later. CONCLUSIONS: Foveoschisis is a rare complication of GA. Vitamin B6 supplementation may alleviate foveoschisis, but its effort for reducing serum ornithine level might be limited. Potential drug adverse effects should be noted in pediatric patients.


Subject(s)
Gyrate Atrophy , Pharmaceutical Preparations , Atrophy/pathology , Child , China , Choroid/pathology , Female , Fluorescein Angiography , Gyrate Atrophy/drug therapy , Humans , Tomography, Optical Coherence , Visual Acuity , Vitamin B 6
13.
Sensors (Basel) ; 20(15)2020 Jul 29.
Article in English | MEDLINE | ID: mdl-32751338

ABSTRACT

Underwater acoustic and optical data fusion has been developed in recent decades. Matching of underwater acoustic and optical images is a fundamental and critical problem in underwater exploration because it usually acts as the key step in many applications, such as target detection, ocean observation, and joint positioning. In this study, a method of matching the same underwater object in acoustic and optical images was designed, consisting of two steps. First, an enhancement step is used to enhance the images and ensure the accuracy of the matching results based on iterative processing and estimate similarity. The acoustic and optical images are first pre-processed with the aim of eliminating the influence of contrast degradation, contour blur, and image noise. A method for image enhancement was designed based on iterative processing. In addition, a new similarity estimation method for acoustic and optical images is also proposed to provide the enhancement effect. Second, a matching step is used to accurately find the corresponding object in the acoustic images that appears in the underwater optical images. In the matching process, a correlation filter is applied to determine the correlation for matching between images. Due to the differences of angle and imaging principle between underwater optical and acoustic images, there may be major differences of size between two images of the same object. In order to eliminate the effect of these differences, we introduce the Gaussian scale-space, which is fused with multi-scale detection to determine the matching results. Therefore, the algorithm is insensitive to scale differences. Extensive experiments demonstrate the effectiveness and accuracy of our proposed method in matching acoustic and optical images.

14.
Materials (Basel) ; 12(19)2019 Oct 07.
Article in English | MEDLINE | ID: mdl-31591313

ABSTRACT

A new synthesis method for organic-inorganic hybrid Poly(vinylidene fluoride)-SiO2 cation-change membranes (CEMs) is proposed. This method involves mixing tetraethyl orthosilicate (TEOS) and 3-mercapto-propyl-triethoxy-silane (MPTES) into a polyvinylidene fluoride (PVDF) sol-gel solution. The resulting slurry was used to prepare films, which were immersed in 0.01 M HCl, which caused hydrolysis and polycondensation between the MPTES and TEOS. The resulting Si-O-Si polymers chains intertwined and/or penetrated the PVDF skeleton, significantly improving the mechanical strength of the resulting hybrid PVDF-SiO2 CEMs. The -SH functional groups of MPTES oxidized to-SO3H, which contributed to the excellent permeability of these CEMs. The surface morphology, hybrid structure, oxidative stability, and physicochemical properties (IEC, water uptake, membrane resistance, membrane potential, transport number, and selective permittivity) of the CEMs obtained in this work were characterized using scanning electron microscope and Fourier transform infrared spectroscopy, as well as electrochemical testing. Tests to analyze the oxidative stability, water uptake, membrane potential, and selective permeability were also performed. Our organic-inorganic hybrid PVDF-SiO2 CEMs demonstrated higher oxidative stability and lower resistance than commercial Ionsep-HC-C membranes with a hydrocarbon structure. Thus, the synthesis method described in this work is very promising for the production of very efficient CEMs. In addition, the physical and electrochemical properties of the PVDF-SiO2 CEMs are comparable to the Ionsep-HC-C membranes. The electrolysis of the concentrated CoCl2 solution performed using PVDF-SiO2-6 and Ionsep-HC-C CEMs showed that at the same current density, Co2+ production, and current efficiency of the PVDF-SiO2-6 CEM membrane were slightly higher than those obtained using the Ionsep-HC-C membrane. Therefore, our novel membrane might be suitable for the recovery of cobalt from concentrated CoCl2 solutions.

15.
Sensors (Basel) ; 19(9)2019 Apr 28.
Article in English | MEDLINE | ID: mdl-31035413

ABSTRACT

Deployment of surface-level gateways holds potential as an effective method to alleviate high-propagation delays and high-error probability in an underwater wireless sensor network (UWSN). This promise comes from reducing distances to underwater nodes and using radio waves to forward information to a control station. In an UWSN, a dynamic energy efficient surface-level gateway deployment is required to cope with the mobility of underwater nodes while considering the remote and three-dimensional nature of marine space. In general, deployment problems are usually modeled as an optimization problem to satisfy multiple constraints given a set of parameters. One previously published static deployment optimization framework makes assumptions about network workload, routing, medium access control performance, and node mobility. However, in real underwater environments, all these parameters are dynamic. Therefore, the accuracy of performance estimates calculated through static UWSN deployment optimization framework tends to be limited by nature. This paper presents the Prediction-Assisted Dynamic Surface Gateway Placement (PADP) algorithm to maximize the coverage and minimize the average end-to-end delay of a mobile underwater sensor network over a specified period. PADP implements the Interacting Multiple Model (IMM) tracking scheme to predict the positions of sensor nodes. The deployment is determined based on both current and predicted positions of sensor nodes, which enables better coverage and shorter end-to-end delay. PADP uses a branch-and-cut approach to solve the optimization problem efficiently, and employs a disjoint-set data structure to ensure connectivity. Simulation results illustrate that PADP significantly outperforms a static gateway deployment scheme.

16.
Plant Cell Environ ; 41(5): 1139-1153, 2018 05.
Article in English | MEDLINE | ID: mdl-29126343

ABSTRACT

Protein lysine acylations, such as succinylation and acetylation, are important post-translational modification (PTM) mechanisms, with key roles in cellular regulation. Antibody-based affinity enrichment, high-resolution liquid chromatography mass spectrometry analysis, and integrated bioinformatics analysis were used to characterize the lysine succinylome (Ksuc ) and acetylome (Kace ) of rice leaves. In total, 2,593 succinylated and 1,024 acetylated proteins were identified, of which 723 were simultaneously acetylated and succinylated. Proteins involved in photosynthetic carbon metabolism such as the large and small subunits of RuBisCO, ribosomal functions, and other key processes were subject to both PTMs. Preliminary insights into oxidant-induced changes to the rice acetylome and succinylome were gained from treatments with hydrogen peroxide. Exposure to oxidative stress did not regulate global changes in the rice acetylome or succinylome but rather led to modifications on a specific subset of the identified sites. De-succinylation of recombinant catalase (CATA) and glutathione S-transferase (OsGSTU6) altered the activities of these enzymes showing that this PTM may have a regulatory function. These findings not only greatly extend the list of acetylated and/or succinylated proteins but they also demonstrate the close cooperation between these PTMs in leaf proteins with key metabolic functions.


Subject(s)
Gene Expression Regulation, Plant , Lysine/metabolism , Oryza/physiology , Plant Proteins/metabolism , Protein Processing, Post-Translational , Proteome , Acetylation , Aminoacylation , Chromatography, Liquid , Mass Spectrometry , Oxidative Stress , Photosynthesis , Plant Leaves/physiology , Plant Proteins/genetics , Succinic Acid/metabolism
17.
Plant Cell Environ ; 40(9): 1777-1790, 2017 Sep.
Article in English | MEDLINE | ID: mdl-28474399

ABSTRACT

Previous studies revealed that rice heme oxygenase PHOTOPERIOD SENSITIVITY 5 (OsSE5) is involved in the regulation of tolerance to excess ammonium by enhancing antioxidant defence. In this study, the relationship between OsSE5 and hydrogen sulfide (H2 S), a well-known signalling molecule, was investigated. Results showed that NH4 Cl triggered the induction of l-cysteine desulfhydrase (l-DES)-related H2 S production in rice seedling roots. A H2 S donor not only alleviated the excess ammonium-triggered inhibition of root growth but also reduced endogenous ammonium, both of which were aggravated by hypotaurine (HT, a H2 S scavenger) or dl-propargylglycine (PAG, a l-DES inhibitor). Nitrogen metabolism-related enzymes were activated by H2 S, thus resulting in the induction of amino acid synthesis and total nitrogen content. Interestingly, the activity of l-DES, as well as the enzymes involved in nitrogen metabolism, was significantly increased in the OsSE5-overexpression line (35S:OsSE5), whereas it impaired in the OsSE5-knockdown mutant (OsSE5-RNAi). The application of the HT/PAG or H2 S donor could differentially block or rescue NH4 Cl-hyposensitivity or hypersensitivity phenotypes in 35S:OsSE5-1 or OsSE5-RNAi-1 plants, with a concomitant modulation of nitrogen assimilation. Taken together, these results illustrated that H2 S function as an indispensable positive regulator participated in OsSE5-promoted ammonium tolerance, in which nitrogen metabolism was facilitated.


Subject(s)
Adaptation, Physiological/drug effects , Ammonium Compounds/toxicity , Cystathionine gamma-Lyase/metabolism , Hydrogen Sulfide/metabolism , Oryza/enzymology , Oryza/physiology , Plant Proteins/metabolism , Plant Roots/physiology , Alkynes/pharmacology , Amino Acids/metabolism , Ammonia/metabolism , Ammonium Chloride/pharmacology , Biosynthetic Pathways/drug effects , Glycine/analogs & derivatives , Glycine/pharmacology , Malondialdehyde/metabolism , Nitrogen/metabolism , Oryza/drug effects , Phenotype , Plant Roots/drug effects , RNA Interference , Stress, Physiological/drug effects , Taurine/analogs & derivatives , Taurine/pharmacology , Time Factors
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