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1.
Transplant Cell Ther ; 2024 Mar 27.
Article in English | MEDLINE | ID: mdl-38548227

ABSTRACT

Acute graft versus host disease (GVHD) is a common and serious complication of allogeneic hematopoietic cell transplantation (HCT) in children but overall clinical grade at onset only modestly predicts response to treatment and survival outcomes. Two tools to assess risk at initiation of treatment were recently developed. The Minnesota risk system stratifies children for risk of nonrelapse mortality (NRM) according to the pattern of GVHD target organ severity. The Mount Sinai Acute GVHD International Consortium (MAGIC) algorithm of 2 serum biomarkers (ST2 and REG3α) predicts NRM in adult patients but has not been validated in a pediatric population. We aimed to develop and validate a system that stratifies children at the onset of GVHD for risk of 6-month NRM. We determined the MAGIC algorithm probabilities (MAPs) and Minnesota risk for a multicenter cohort of 315 pediatric patients who developed GVHD requiring treatment with systemic corticosteroids. MAPs created 3 risk groups with distinct outcomes at the start of treatment and were more accurate than Minnesota risk stratification for prediction of NRM (area under the receiver operating curve (AUC), .79 versus .62, P = .001). A novel model that combined Minnesota risk and biomarker scores created from a training cohort was more accurate than either biomarkers or clinical systems in a validation cohort (AUC .87) and stratified patients into 2 groups with highly different 6-month NRM (5% versus 38%, P < .001). In summary, we validated the MAP as a prognostic biomarker in pediatric patients with GVHD, and a novel risk stratification that combines Minnesota risk and biomarker risk performed best. Biomarker-based risk stratification can be used in clinical trials to develop more tailored approaches for children who require treatment for GVHD.

3.
Nanoscale ; 15(39): 16016-16029, 2023 Oct 12.
Article in English | MEDLINE | ID: mdl-37753868

ABSTRACT

The clinical translation of many biomolecular therapeutics has been hindered by undesirable pharmacokinetic (PK) properties, inadequate membrane permeability, poor endosomal escape and cytosolic delivery, and/or susceptibility to degradation. Overcoming these challenges merits the development of nanoscale drug carriers (nanocarriers) to improve the delivery of therapeutic cargo. Herein, we implement a flash nanoprecipitation (FNP) approach to produce nanocarriers of diverse vesicular morphologies by using various molecular weight PEG-bl-DEAEMA-co-BMA (PEG-DB) polymers. We demonstrated that FNP can produce uniform (PDI < 0.1) particles after 5 impingements, and that by varying the copolymer hydrophilic mass fraction, FNP enables access to a diverse variety of nanoarchitectures including micelles, unilamellar vesicles (polymersomes), and multi-compartment vesicles (MCVs). We synthesized a library of 2 kDa PEG block copolymers, with DEAEMA-co-BMA second block molecular weights of 3, 6, 12, 15, 20, and 30 kDa. All formulations were both pH responsive, endosomolytic, and capable of loading and cytosolically delivering small negatively charged molecules - albeit to different degrees. Using a B16.F10 melanoma model, we showcased the therapeutic potential of a lead FNP formulated PEG-DB nanocarrier, encapsulating the cyclic dinucleotide (CDN) cGAMP to activate the stimulator of interferon genes (STING) pathway in a therapeutically relevant context. Collectively, these data demonstrate that an FNP process can be used to formulate pH-responsive nanocarriers of diverse morphologies using a PEG-DB polymer system. As FNP is an industrially scalable process, these data address the critical translational challenge of producing PEG-DB nanoparticles at scale. Furthermore, the diverse morphologies produced may specialize in the delivery of distinct biomolecular cargos for other therapeutic applications, implicating the therapeutic potential of this platform in an array of disease applications.


Subject(s)
Nanoparticles , Polymers , Polymers/chemistry , Drug Carriers/chemistry , Nanoparticles/chemistry , Micelles , Endosomes/metabolism , Polyethylene Glycols/chemistry
4.
Sci Rep ; 13(1): 7486, 2023 05 09.
Article in English | MEDLINE | ID: mdl-37161076

ABSTRACT

Fatty acid amide hydrolase (FAAH) is a widely conserved amidase in eukaryotes, perhaps best known for inactivating N-acylethanolamine lipid mediators. However, FAAH enzymes hydrolyze a wide range of acylamide substrates. Analysis of FAAHs from multiple angiosperm species revealed two conserved phylogenetic groups that differed in key conserved residues in the substrate binding pocket. While the foundation group of plant FAAHs, designated FAAH1, has been studied at the structural and functional level in Arabidopsis thaliana, nothing is known about FAAH2 members. Here, we combined computational and biochemical approaches to compare the structural and enzymatic properties of two FAAH isoforms in the legume Medicago truncatula designated MtFAAH1 and MtFAAH2a. Differences in structural and physicochemical properties of the substrate binding pockets, predicted from homology modeling, molecular docking, and molecular dynamic simulation experiments, suggested that these two FAAH isoforms would exhibit differences in their amidohydrolase activity profiles. Indeed, kinetic studies of purified, recombinant MtFAAHs indicated a reciprocal preference for acylamide substrates with MtFAAH1 more efficiently utilizing long-chain acylamides, and MtFAAH2a more efficiently hydrolyzing short-chain and aromatic acylamides. This first report of the enzymatic behavior of two phylogenetically distinct plant FAAHs will provide a foundation for further investigations regarding FAAH isoforms in legumes and other plant species.


Subject(s)
Arabidopsis , Medicago truncatula , Kinetics , Molecular Docking Simulation , Phylogeny , Vegetables , Amidohydrolases/genetics , Protein Isoforms
5.
Plant Physiol ; 191(2): 1234-1253, 2023 02 12.
Article in English | MEDLINE | ID: mdl-36472510

ABSTRACT

Polyunsaturated N-acylethanolamines (NAEs) can be hydrolyzed by fatty acid amide hydrolase (FAAH) or oxidized by lipoxygenase (LOX). In Arabidopsis (Arabidopsis thaliana), the 9-LOX product of linoleoylethanolamide, namely, 9-hydroxy linoleoylethanolamide (9-NAE-HOD), is reported to negatively regulate seedling development during secondary dormancy. In upland cotton (Gossypium hirsutum L.), six putative FAAH genes (from two diverged groups) and six potential 9-LOX genes are present; however, their involvement in 9-NAE-HOD metabolism and its regulation of seedling development remain unexplored. Here, we report that in cotton plants, two specific FAAH isoforms (GhFAAH Ib and GhFAAH IIb) are needed for hydrolysis of certain endogenous NAEs. Virus-induced gene silencing (VIGS) of either or both FAAHs led to reduced seedling growth and this coincided with reduced amidohydrolase activities and elevated quantities of endogenous 9-NAE-HOD. Transcripts of GhLOX21 were consistently elevated in FAAH-silenced tissues, and co-silencing of GhLOX21 and GhFAAH (Ib and/or IIb) led to reversal of seedling growth to normal levels (comparable with no silencing). This was concomitant with reductions in the levels of 9-NAE-HOD, but not of 13-NAE-HOD. Pharmacological experiments corroborated the genetic and biochemical evidence, demonstrating that direct application of 9-NAE-HOD, but not 13-NAE-HOD or their corresponding free fatty acid oxylipins, inhibited the growth of cotton seedlings. Additionally, VIGS of GhLOX21 in cotton lines overexpressing AtFAAH exhibited enhanced growth and no detectable 9-NAE-HOD. Altogether, we conclude that the growth of cotton seedlings involves fine-tuning of 9-NAE-HOD levels via FAAH-mediated hydrolysis and LOX-mediated production, expanding the mechanistic understanding of plant growth modulation by NAE oxylipins to a perennial crop species.


Subject(s)
Arabidopsis , Seedlings , Seedlings/metabolism , Oxylipins/pharmacology , Oxylipins/metabolism , Gossypium/genetics , Gossypium/metabolism , Lipoxygenase/metabolism , Arabidopsis/metabolism , Amidohydrolases/genetics , Amidohydrolases/metabolism
6.
Plant Direct ; 6(7): e421, 2022 Jul.
Article in English | MEDLINE | ID: mdl-35844778

ABSTRACT

Fatty acid amide hydrolase (FAAH) is a conserved amidase that is known to modulate the levels of endogenous N-acylethanolamines (NAEs) in both plants and animals. The activity of FAAH is enhanced in vitro by synthetic phenoxyacylethanolamides resulting in greater hydrolysis of NAEs. Previously, 3-n-pentadecylphenolethanolamide (PDP-EA) was shown to exert positive effects on the development of Arabidopsis seedlings by enhancing Arabidopsis FAAH (AtFAAH) activity. However, there is little information regarding FAAH activity and the impact of PDP-EA in the development of seedlings of other plant species. Here, we examined the effects of PDP-EA on growth of upland cotton (Gossypium hirsutum L. cv Coker 312) seedlings including two lines of transgenic seedlings overexpressing AtFAAH. Independent transgenic events showed accelerated true-leaf emergence compared with non-transgenic controls. Exogenous applications of PDP-EA led to increases in overall seedling growth in AtFAAH transgenic lines. These enhanced-growth phenotypes coincided with elevated FAAH activities toward NAEs and NAE oxylipins. Conversely, the endogenous contents of NAEs and NAE-oxylipin species, especially linoleoylethanolamide and 9-hydroxy linoleoylethanolamide, were lower in PDP-EA treated seedlings than in controls. Further, transcripts for endogenous cotton FAAH genes were increased following PDP-EA exposure. Collectively, our data corroborate that the enhancement of FAAH enzyme activity by PDP-EA stimulates NAE-hydrolysis and that this results in enhanced growth in seedlings of a perennial crop species, extending the role of NAE metabolism in seedling development beyond the model annual plant species, Arabidopsis thaliana.

7.
Bone Jt Open ; 2(10): 850-857, 2021 Oct.
Article in English | MEDLINE | ID: mdl-34665003

ABSTRACT

AIMS: Orthopaedic surgeries are complex, frequently performed procedures associated with significant haemorrhage and perioperative blood transfusion. Given refinements in surgical techniques and changes to transfusion practices, we aim to describe contemporary transfusion practices in orthopaedic surgery in order to inform perioperative planning and blood banking requirements. METHODS: We performed a retrospective cohort study of adult patients who underwent orthopaedic surgery at four Canadian hospitals between 2014 and 2016. We studied all patients admitted to hospital for nonarthroscopic joint surgeries, amputations, and fracture surgeries. For each surgery and surgical subgroup, we characterized the proportion of patients who received red blood cell (RBC) transfusion, the mean/median number of RBC units transfused, and exposure to platelets and plasma. RESULTS: Of the 14,584 included patients, the most commonly performed surgeries were knee arthroplasty (24.8%), hip arthroplasty (24.6%), and hip fracture surgery (17.4%). A total of 10.3% of patients received RBC transfusion; the proportion of patients receiving RBC transfusions varied widely based on the surgical subgroup (0.0% to 33.1%). Primary knee arthroplasty and hip arthroplasty, the two most common surgeries, were associated with in-hospital transfusion frequencies of 2.8% and 4.5%, respectively. RBC transfusion occurred in 25.0% of hip fracture surgeries, accounting for the greatest total number of RBC units transfused in our cohort (38.0% of all transfused RBC units). Platelet and plasma transfusions were uncommon. CONCLUSION: Orthopaedic surgeries were associated with variable rates of transfusion. The rate of RBC transfusion is highly dependent on the surgery type. Identifying surgeries with the highest transfusion rates, and further evaluation of factors that contribute to transfusion in identified at-risk populations, can serve to inform perioperative planning and blood bank requirements, and facilitate pre-emptive transfusion mitigation strategies. Cite this article: Bone Jt Open 2021;2(10):850-857.

8.
Methods Mol Biol ; 2295: 417-438, 2021.
Article in English | MEDLINE | ID: mdl-34047991

ABSTRACT

Matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) has emerged as a major analytical platform for the determination and localization of lipid metabolites directly from tissue sections. Unlike analysis of lipid extracts, where lipid localizations are lost due to homogenization and/ or solvent extraction, MALDI-MSI analysis is capable of revealing spatial localization of metabolites while simultaneously collecting high chemical resolution mass spectra. Important considerations for obtaining high quality MALDI-MS images include tissue preservation, section preparation, MS data collection and data processing. Errors in any of these steps can lead to poor quality metabolite images and increases the chance for metabolite misidentification and/ or incorrect localization. Here, we present detailed methods and recommendations for specimen preparation, MALDI-MS instrument parameters, software analysis platforms for data processing, and practical considerations for each of these steps to ensure acquisition of high-quality chemical and spatial resolution data for reconstructing MALDI-MS images of plant tissues.


Subject(s)
Lipids/chemistry , Plants/chemistry , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization/methods , Diagnostic Imaging/methods , Histological Techniques/methods , Image Processing, Computer-Assisted/methods , Lipid Metabolism/physiology , Plants/metabolism , Software
9.
Blood Adv ; 4(24): 6098-6105, 2020 12 22.
Article in English | MEDLINE | ID: mdl-33351103

ABSTRACT

Steroid-refractory (SR) acute graft-versus-host disease (GVHD) remains a major cause of nonrelapse mortality (NRM) after allogeneic hematopoietic cell transplantation (HCT), but its occurrence is not accurately predicted by pre-HCT clinical risk factors. The Mount Sinai Acute GVHD International Consortium (MAGIC) algorithm probability (MAP) identifies patients who are at high risk for developing SR GVHD as early as 7 days after HCT based on the extent of intestinal crypt damage as measured by the concentrations of 2 serum biomarkers, suppressor of tumorigenesis 2 and regenerating islet-derived 3α. We conducted a multicenter proof-of-concept "preemptive" treatment trial of α-1-antitrypsin (AAT), a serine protease inhibitor with demonstrated activity against GVHD, in patients at high risk for developing SR GVHD. Patients were eligible if they possessed a high-risk MAP on day 7 after HCT or, if initially low risk, became high risk on repeat testing at day 14. Thirty high-risk patients were treated with twice-weekly infusions of AAT for a total of 16 doses, and their outcomes were compared with 90 high-risk near-contemporaneous MAGIC control patients. AAT treatment was well tolerated with few toxicities, but it did not lower the incidence of SR GVHD compared with controls (20% vs 14%, P = .56). We conclude that real-time biomarker-based risk assignment is feasible early after allogeneic HCT but that this dose and schedule of AAT did not change the incidence of SR acute GVHD. This trial was registered at www.clinicaltrials.gov as #NCT03459040.


Subject(s)
Graft vs Host Disease , Hematopoietic Stem Cell Transplantation , Biomarkers , Graft vs Host Disease/drug therapy , Graft vs Host Disease/etiology , Hematopoietic Stem Cell Transplantation/adverse effects , Humans , Steroids
10.
Global Spine J ; 10(2 Suppl): 17S-21S, 2020 Apr.
Article in English | MEDLINE | ID: mdl-32528802

ABSTRACT

Degenerative lumbar spine disease (DLSD) is a heterogenous group of conditions that can significantly affect patients' quality of life. Lateral lumbar interbody fusion (LLIF) is one of the treatment modalities for DLSD that has been increasing in popularity over the past decade. The treatment of DLSD should be individualized based on patients' symptoms and characteristics to maximize outcomes. METHODS: Literature review, invited review. RESULTS: In this article, we will (1) review the use of the LLIF technique in the treatment of degenerative lumbar spine disease, (2) review the current concepts of LLIF, and (3) explore the evidence to date that will allow the reader to maximize the benefits of this technique. CONCLUSIONS: LLIF is an alternative for the treatment of degenerative pathologies of the lumbar spine via indirect decompression.

11.
Leukemia ; 34(7): 1898-1906, 2020 07.
Article in English | MEDLINE | ID: mdl-32020045

ABSTRACT

The graft-versus-leukemia (GVL) effect after allogeneic hematopoietic cell transplant (HCT) can prevent relapse but the risk of severe graft-versus-host disease (GVHD) leads to prolonged intensive immunosuppression and possible blunting of the GVL effect. Strategies to reduce immunosuppression in order to prevent relapse have been offset by increases in severe GVHD and nonrelapse mortality (NRM). We recently validated the MAGIC algorithm probability (MAP) that predicts the risk for severe GVHD and NRM in asymptomatic patients using serum biomarkers. In this study we tested whether the MAP could identify patients whose risk for relapse is higher than their risk for severe GVHD and NRM. The multicenter study population (n = 1604) was divided into two cohorts: historical (2006-2015, n = 702) and current (2015-2017, n = 902) with similar NRM, relapse, and survival. On day 28 post-HCT, patients who had not developed GVHD (75% of the population) and who possessed a low MAP were at much higher risk for relapse (24%) than severe GVHD and NRM (16 and 9%); this difference was even more pronounced in patients with a high disease risk index (relapse 33%, NRM 9%). Such patients are good candidates to test relapse prevention strategies that might enhance GVL.


Subject(s)
Algorithms , Biomarkers/blood , Graft vs Host Disease/mortality , Hematologic Neoplasms/mortality , Hematopoietic Stem Cell Transplantation/mortality , Neoplasm Recurrence, Local/mortality , Follow-Up Studies , Graft vs Host Disease/blood , Graft vs Host Disease/diagnosis , Hematologic Neoplasms/blood , Hematologic Neoplasms/therapy , Humans , Neoplasm Recurrence, Local/blood , Neoplasm Recurrence, Local/epidemiology , Prognosis , Risk Factors , Survival Rate , Transplantation Conditioning , Transplantation, Homologous
12.
Trends Plant Sci ; 25(3): 236-249, 2020 03.
Article in English | MEDLINE | ID: mdl-31919033

ABSTRACT

Fatty acid amide hydrolase (FAAH) is an enzyme that belongs to the amidase signature (AS) superfamily and is widely distributed in multicellular eukaryotes. FAAH hydrolyzes lipid signaling molecules - namely, N-acylethanolamines (NAEs) - which terminates their actions. Recently, the crystal structure of Arabidopsis thaliana FAAH was solved and key residues were identified for substrate-specific interactions. Here, focusing on residues surrounding the substrate-binding pocket, a comprehensive analysis of FAAH sequences from angiosperms reveals a distinctly different family of FAAH-like enzymes. We hypothesize that FAAH, in addition to its role in seedling development, also acts in an N-acyl amide communication axis to facilitate plant-microbe interactions and that structural diversity provides for the flexible use of a wide range of small lipophilic signaling molecules.


Subject(s)
Amidohydrolases , Arabidopsis
13.
Blood Adv ; 3(23): 4034-4042, 2019 12 10.
Article in English | MEDLINE | ID: mdl-31816061

ABSTRACT

The Mount Sinai Acute GVHD International Consortium (MAGIC) algorithm probability (MAP), derived from 2 serum biomarkers, measures damage to crypts in the gastrointestinal tract during graft-versus-host disease (GVHD). We hypothesized that changes in MAP after treatment could validate it as a response biomarker. We prospectively collected serum samples and clinical stages of acute GVHD from 615 patients receiving hematopoietic cell transplantation in 20 centers at initiation of first-line systemic treatment and 4 weeks later. We computed MAPs and clinical responses and compared their abilities to predict 6-month nonrelapse mortality (NRM) in the validation cohort (n = 367). After 4 weeks of treatment, MAPs predicted NRM better than the change in clinical symptoms in all patients and identified 2 groups with significantly different NRM in both clinical responders (40% vs 12%, P < .0001) and nonresponders (65% vs 25%, P < .0001). MAPs successfully reclassified patients for NRM risk within every clinical grade of acute GVHD after 4 weeks of treatment. At the beginning of treatment, patients with a low MAP that rose above the threshold of 0.290 after 4 weeks of treatment had a significant increase in NRM, whereas patients with a high MAP at onset that fell below that threshold after treatment had a striking decrease in NRM that translated into clear differences in overall survival. We conclude that a MAP measured before and after treatment of acute GVHD is a response biomarker that predicts long-term outcomes more accurately than change in clinical symptoms. MAPs have the potential to guide therapy for acute GVHD and may function as a useful end point in clinical trials.


Subject(s)
Biomarkers/blood , Graft vs Host Disease/epidemiology , Graft vs Host Disease/therapy , Acute Disease , Algorithms , Humans , Probability
14.
Ann Transl Med ; 7(10): 223, 2019 May.
Article in English | MEDLINE | ID: mdl-31297388

ABSTRACT

The spine is one of the most common sites of bony metastases, and its involvement leads to significant patient morbidity. Surgical management in these patients is aimed at improving quality of life and functional status throughout the course of the disease. Resection of metastases often leads to critical size bone defects, presenting a challenge to achieving adequate bone regeneration to fill the void. Current treatment options for repairing these defects are bone grafting and commercial bone cements; however, each has associated limitations. Additionally, tumor recurrence and tumor-induced bone loss make bone regeneration particularly difficult. Systemic therapeutic delivery, such as bisphosphonates, have become standard of care to combat bone loss despite unfavorable systemic side-effects and lack of local efficacy. Developments from tissue engineering have introduced novel materials with osteoinductive and osteoconductive properties which also act as structural support scaffolds for bone regeneration. These new materials can also act as a therapeutic reservoir to sustainably release drugs locally as an alternative to systemic therapy. In this review, we outline recent advancements in tissue engineering and the role of translational research in developing implants that can fully repair bone defects while also delivering local therapeutics to curb tumor recurrence and improve patient quality of life.

15.
Biochem J ; 476(13): 1929-1942, 2019 07 09.
Article in English | MEDLINE | ID: mdl-31289128

ABSTRACT

Lipid droplets (LDs) are organelles that compartmentalize nonbilayer-forming lipids in the aqueous cytoplasm of cells. They are ubiquitous in most organisms, including in animals, protists, plants and microorganisms. In eukaryotes, LDs are believed to be derived by a budding and scission process from the surface of the endoplasmic reticulum, and this occurs concomitantly with the accumulation of neutral lipids, most often triacylglycerols and steryl esters. Overall, the mechanisms underlying LD biogenesis are difficult to generalize, in part because of the involvement of different sets of both evolutionarily conserved and organism-specific LD-packaging proteins. Here, we briefly compare and contrast these proteins and the allied processes responsible for LD biogenesis in cells of animals, yeasts and plants.


Subject(s)
Endoplasmic Reticulum/metabolism , Lipid Droplets/metabolism , Plants/metabolism , Triglycerides/metabolism , Yeasts/metabolism , Animals , Humans
16.
J Manipulative Physiol Ther ; 42(1): 23-33, 2019 01.
Article in English | MEDLINE | ID: mdl-30955909

ABSTRACT

OBJECTIVE: The purpose of this study was to quantify the impact of a single lumbar spinal manipulation (SM) intervention on the leg movement performance of degenerative lumbar spinal stenosis (LSS) patients in a small-scale registered randomized clinical trial. METHODS: Participants with LSS (n = 14) were tested at baseline for pain, lumbar range of motion, and behavioral or kinematic motor performance (using an established Fitts' Law foot-pointing task), then underwent covariate adaptive randomization to receive SM or no intervention. Postintervention all dependent measures were repeated. Experimenters were blinded to patient group allocation. University ethics board approval was attained. RESULTS: For the primary outcome movement time, there was no significant difference between groups. As predicted by Fitts' Law, all participants had longer movement times as task difficulty increased. Secondary kinematic outcomes yielded no significant between-group differences. Consistent with Fitts' Law, kinematic measures changed significantly with task difficulty. Pairwise comparisons revealed the kinematic variables were more adversely affected by greater movement amplitudes than target size changes. No exploratory differences in pain or lumbar range of motion were observed. CONCLUSION: Changes in motor performance were not observed in this chronic pain population after a single SM intervention compared with a control group. Given the sample size, the study may have been underpowered to detect meaningful differences. Fitts' Law was observed for the lower extremity-pointing task for an LSS population and may provide an objective measure of motor performance.


Subject(s)
Lower Extremity/physiology , Lumbar Vertebrae/physiopathology , Manipulation, Spinal , Movement/physiology , Spinal Stenosis/physiopathology , Spinal Stenosis/rehabilitation , Biomechanical Phenomena/physiology , Female , Humans , Male , Middle Aged , Range of Motion, Articular/physiology , Single-Blind Method
17.
J Biol Chem ; 294(18): 7419-7432, 2019 05 03.
Article in English | MEDLINE | ID: mdl-30894416

ABSTRACT

N-Acylethanolamines (NAEs) are fatty acid derivatives that in animal systems include the well-known bioactive metabolites of the endocannabinoid signaling pathway. Plants use NAE signaling as well, and these bioactive molecules often have oxygenated acyl moieties. Here, we report the three-dimensional crystal structures of the signal-terminating enzyme fatty acid amide hydrolase (FAAH) from Arabidopsis in its apo and ligand-bound forms at 2.1- and 3.2-Å resolutions, respectively. This plant FAAH structure revealed features distinct from those of the only other available FAAH structure (rat). The structures disclosed that although catalytic residues are conserved with the mammalian enzyme, AtFAAH has a more open substrate-binding pocket that is partially lined with polar residues. Fundamental differences in the organization of the membrane-binding "cap" and the membrane access channel also were evident. In accordance with the observed structural features of the substrate-binding pocket, kinetic analysis showed that AtFAAH efficiently uses both unsubstituted and oxygenated acylethanolamides as substrates. Moreover, comparison of the apo and ligand-bound AtFAAH structures identified three discrete sets of conformational changes that accompany ligand binding, suggesting a unique "squeeze and lock" substrate-binding mechanism. Using molecular dynamics simulations, we evaluated these conformational changes further and noted a partial unfolding of a random-coil helix within the region 531-537 in the apo structure but not in the ligand-bound form, indicating that this region likely confers plasticity to the substrate-binding pocket. We conclude that the structural divergence in bioactive acylethanolamides in plants is reflected in part in the structural and functional properties of plant FAAHs.


Subject(s)
Amidohydrolases/chemistry , Arabidopsis/enzymology , Biological Evolution , Amidohydrolases/metabolism , Animals , Ethanolamines/chemistry , Ligands , Protein Conformation , Rats , Substrate Specificity
18.
Front Plant Sci ; 10: 1744, 2019.
Article in English | MEDLINE | ID: mdl-32082336

ABSTRACT

Brassica napus (B. napus) is the world's most widely grown temperate oilseed crop. Although breeding for human consumption has led to removal of erucic acid from refined canola oils, there is renewed interest in the industrial uses of erucic acid derived from B. napus, and there is a rich germplasm available for use. Here, low- and high-erucic acid accessions of B. napus seeds were examined for the distribution of erucic acid-containing lipids and the gene transcripts encoding the enzymes involved in pathways for its incorporation into triacylglycerols (TAGs) across the major tissues of the seeds. In general, the results indicate that a heterogeneous distribution of erucic acid across B. napus seed tissues was contributed by two isoforms (out of six) of FATTY ACYL COA ELONGASE (FAE1) and a combination of phospholipid:diacylglycerol acyltransferase (PDAT)- and diacylglycerol acyltransferase (DGAT)-mediated incorporation of erucic acid into TAGs in cotyledonary tissues. An absence of the expression of these two FAE1 isoforms accounted for the absence of erucic acid in the TAGs of the low-erucic accession.

20.
Catheter Cardiovasc Interv ; 92(6): 1163-1170, 2018 11 15.
Article in English | MEDLINE | ID: mdl-30079597

ABSTRACT

BACKGROUND: Transcatheter Aortic Valve Implantation (TAVI) is commonly used to deploy new bioprosthetic valves inside degenerated surgically implanted aortic valves in high risk patients. The three scoring systems used to assess risk of postprocedural mortality are: Logistic EuroSCORE (LES), EuroSCORE II (ES II), and Society of Thoracic Surgeons (STS). OBJECTIVE: The purpose of this study is to analyze the accuracy of LES, ES II, and STS in estimating all-cause mortality after transcatheter aortic valve-in-valve (ViV) implantations, which was not assessed before. METHODS: Using the Valve-in-Valve International Data (VIVID) registry, a total of 1,550 patients from 110 centers were included. The study compared the observed 30-day overall mortality vs. the respective predicted mortalities calculated by risk scores. The accuracy of prediction models was assessed based on calibration and discrimination. RESULTS: Observed mortality at 30 days was 5.3%, while average expected mortalities by LES, ES II and STS were 29.49 (± 17.2), 14.59 (± 8.6), and 9.61 (± 8.51), respectively. All three risk scores overestimated 30-day mortality with ratios of 0.176 (95% CI 0.138-0.214), 0.342 (95% CI 0.264-0.419), and 0.536 (95% CI 0.421-0.651), respectively. 30-day mortality ROC curves demonstrated that ES II had the largest AUC at 0.722, followed by STS at 0.704, and LES at 0.698. CONCLUSIONS: All three scores overestimated mortality at 30 days with ES II showing the highest predictability compared to LES and STS; and therefore, should be recommended for ViV procedures. There is a need for a dedicated scoring system for patients undergoing ViV interventions.


Subject(s)
Aortic Valve/surgery , Bioprosthesis , Decision Support Techniques , Heart Valve Prosthesis Implantation/instrumentation , Heart Valve Prosthesis Implantation/mortality , Heart Valve Prosthesis , Prosthesis Failure , Transcatheter Aortic Valve Replacement/instrumentation , Transcatheter Aortic Valve Replacement/mortality , Aged , Aged, 80 and over , Aortic Valve/physiopathology , Female , Heart Valve Prosthesis Implantation/adverse effects , Humans , Male , Predictive Value of Tests , Prosthesis Design , Registries , Risk Assessment , Risk Factors , Time Factors , Transcatheter Aortic Valve Replacement/adverse effects , Treatment Outcome
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